Science.gov

Sample records for activities suggested materials

  1. Studies and Suggestions on Prewriting Activities

    ERIC Educational Resources Information Center

    Zheng, Shigao; Dai, Weiping

    2012-01-01

    This paper studies and suggests the need for writing instruction by which students can experience writing as a creative process in exploring and communicating meaning. The prewriting activities generate ideas which can encourage a free flow of thoughts and help students discover both what they want to say and how to say it on paper. Through the…

  2. Suggested Activities for a Unit on the Middle East.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    1983-01-01

    Student activities that focus on the different cultures and the history of the Middle East from Biblical times to the present are suggested. These include debates, art projects, slide shows, maps, and research problems. (IS)

  3. World War II Commemoration Committee: Fact Sheet and Suggested Activities.

    ERIC Educational Resources Information Center

    Department of Defense, Washington, DC.

    This packet suggests activities and events that school districts, schools, classes, and educational organizations can conduct to commemorate World War II. Suggestions are made to include local veterans, including those in veteran's and nursing homes and hospitals, and youth at every possible opportunity. Recognition can take the form of military…

  4. [Ute Unit with History, Suggested Activities, and Teachers' Guide.

    ERIC Educational Resources Information Center

    Montelores Studies Center, Cortez, CO.

    This curriculum unit for fourth grade students, developed by the Montelores Studies Center, Cortez, Colorado, which is funded by the Elementary and Secondary Education Act, Title III, presents a history of the Ute Indians, suggested activities for students, and a teachers' guide. The history section outlines the historical development of the Ute…

  5. Calculator-Active Materials.

    ERIC Educational Resources Information Center

    Crow, Tracy, Ed.; Harris, Julia, Ed.

    1997-01-01

    This journal contains brief descriptions of calculator-active materials that were found using Resource Finder, the searchable online catalog of curriculum resources from the Eisenhower National Clearinghouse (ENC). It features both the calculators themselves and the activity books that are used with them. Among the calculators included are those…

  6. Cosmogenic activation of materials

    SciTech Connect

    Amare, J.; Beltran, B.; Carmona, J.M.; Cebrian, S.; Garcia, E.; Irastorza, I.G.; Gomez, H.; Luzon, G.; Martinez, M.; Morales, J.; Ortiz de Solorzano, A.; Pobes, C.; Puimedon, J.; Rodriguez, A.; Ruz, J.; Sarsa, M. L.; Torres, L.; Villar, J.A.; Capelli, S.; Capozzi, F.

    2005-09-08

    The problem of cosmogenic activation produced at sea level in materials typically used in underground experiments looking for rare events is being studied. Several nuclear data libraries have been screened looking for relevant isotope production cross-sections and different codes which can be applied to activation studies have been reviewed. The excitation functions for some problems of interest like production of 60Co and 68Ge in germanium and production of 60Co in tellurium have been obtained taking into account both measurements and calculations and a preliminary estimate of the corresponding rates of production at sea level has been performed.

  7. Activated carbon material

    DOEpatents

    Evans, A. Gary

    1978-01-01

    Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards.

  8. Geothermal materials development activities

    SciTech Connect

    Kukacka, L.E.

    1993-06-01

    This ongoing R&D program is a part of the Core Research Category of the Department of Energy/Geothermal Division initiative to accelerate the utilization of geothermal resources. High risk materials problems that if successfully solved will result in significant reductions in well drilling, fluid transport and energy conversion costs, are emphasized. The project has already developed several advanced materials systems that are being used by the geothermal industry and by Northeastern Electric, Gas and Steam Utilities. Specific topics currently being addressed include lightweight C0{sub 2}-resistant well cements, thermally conductive scale and corrosion resistant liner systems, chemical systems for lost circulation control, elastomer-metal bonding systems, and corrosion mitigation at the Geysers. Efforts to enhance the transfer of the technologies developed in these activities to other sectors of the economy are also underway.

  9. Think Texas! Suggested Activities to Help Celebrate Our Sesquicentennial.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    A packet of teaching activities helps elementary and secondary teachers commemorate the sesquicentennial of Texas' independence. Activities include listening to stories about the mockingbird, bluebonnet, and pecan tree, drawing interpretations of these stories, and using a graphics tablet, light pen, or graphics software to illustrate a Texas folk…

  10. Physical activity in adolescence. A review with clinical suggestions.

    PubMed

    Lotan, Meir; Merrick, Joav; Carmeli, Eli

    2005-01-01

    Despite some inconsistencies in research methodologies, most findings support a positive correlation between participation in physical activities and well-being in adulthood. The results are consistent across the life span of both genders. Favorable connection between physical exercise to physical, psychological, emotional and educational benefits has been constantly proven. Despite such results a comparison between present to past findings show a global tendency for sedentary life style and reduced physical activities in many countries across ages and genders. There are claims that achieving an adult healthy life style is rooted in habits acquired at early ages, thus pointing at childhood and adolescence as the starting point of an active and healthy adulthood. The present article reviews the current literature and findings relating to physical activity with better health and an emphasis on adolescence. Factors correlated to participation of adolescents in physical activities are presented and some clinical issues to promote such activity are discussed. The authors strongly recommend enhanced initiation of community based easily accessed physical exercise programs, for children and adolescents.

  11. Suggestions, Resources and Activities for Teaching about Japan.

    ERIC Educational Resources Information Center

    Thomas, Paul F.

    This teacher resource packet contains a total of 28 modules for teaching about Japan at the elementary and secondary level. Activities on the Japanese family appropriate for grade 1 focus on similarities and differences, family size, family needs, and family roles. Grade 2 lessons look at the school, neighborhood, roles of children in the…

  12. Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

  13. Suggested Activities for Teaching Reading through the Newspaper.

    ERIC Educational Resources Information Center

    Henney, Maribeth

    The 101 activities using the newspaper for teaching reading listed in this document range from such simple tasks as having children write captions for photos from the newspaper to the more advanced and complicated assignments of learning the use of propaganda devices or the five kinds of news stories. In addition, definitions for newspaper terms…

  14. Mechanically Active Electrospun Materials

    NASA Astrophysics Data System (ADS)

    Robertson, Jaimee M.

    Electrospinning, a technique used to fabricate small diameter polymer fibers, has been employed to develop unique, active materials falling under two categories: (1) shape memory elastomeric composites (SMECs) and (2) water responsive fiber mats. (1) Previous work has characterized in detail the properties and behavior of traditional SMECs with isotropic fibers embedded in an elastomer matrix. The current work has two goals: (i) characterize laminated anisotropic SMECs and (ii) develop a fabrication process that is scalable for commercial SMEC manufacturing. The former ((i)) requires electrospinning aligned polymer fibers. The aligned fibers are similarly embedded in an elastomer matrix and stacked at various fiber orientations. The resulting laminated composite has a unique response to tensile deformation: after stretching and releasing, the composite curls. This curling response was characterized based on fiber orientation. The latter goal ((ii)) required use of a dual-electrospinning process to simultaneously electrospin two polymers. This fabrication approach incorporated only industrially relevant processing techniques, enabling the possibility of commercial application of a shape memory rubber. Furthermore, the approach had the added benefit of increased control over composition and material properties. (2) The strong elongational forces experienced by polymer chains during the electrospinning process induce molecular alignment along the length of electrospun fibers. Such orientation is maintained in the fibers as the polymer vitrifies. Consequently, residual stress is stored in electrospun fiber mats and can be recovered by heating through the polymer's glass transition temperature. Alternatively, the glass transition temperature can be depressed by introducing a plasticizing agent. Poly(vinyl acetate) (PVAc) is plasticized by water, and its glass transition temperature is lowered below room temperature. Therefore, the residual stress can be relaxed at room

  15. Suggested Materials and Themes for a Study of Population in Secondary Social Studies.

    ERIC Educational Resources Information Center

    Beer, Diana Darnall

    The main objective of this thesis is to suggest materials for use in secondary social studies classrooms for improvement of instruction on population and world geography. The thesis provides background information on population, a listing of sources where additional information can be found, and major generalizations, discussion questions, and…

  16. Multinational Exchange Mechanisms of Educational Audio-Visual Materials. Situation and Suggestions.

    ERIC Educational Resources Information Center

    Center of Studies and Realizations for Permanent Education, Paris (France).

    An analysis of existing multinational audiovisual materials exchange organizations, including five nonproducing and three producing national systems and seven nonproducing and five producing international networks, provided the data for an analysis of problems associated with cooperative endeavors, some suggestions for appropriate institutional…

  17. Suggested Activities to Initiate Consumer Education in the Elementary Classroom. Centering On.

    ERIC Educational Resources Information Center

    Mainor, Nancy

    This booklet of teacher-developed and teacher-tested activities and strategies draws upon the curriculum areas of language arts, mathematics and social studies. Though prepared for fourth, fifth and sixth grade students, the material is adaptable for primary grades and can be used for group activities or as individual task cards. Activity sheets…

  18. Materials and Resources Suggested for Team Teaching and Individualized Instruction. Module III.

    ERIC Educational Resources Information Center

    York, L. Jean

    The third of seven modules on team teaching, this document deals with materials and resources, with the objectives that teachers will develop an awareness of the wide variety available, the factors to consider in selecting media, the role of the resource center, and the necessary conditions for effective use of media. The study material includes…

  19. Male Adolescents' Reasons for Participating in Physical Activity, Barriers to Participation, and Suggestions for Increasing Participation

    ERIC Educational Resources Information Center

    Allison, Kenneth R.; Dwyer, John J. M.; Goldenberg, Ellie; Fein, Allan; Yoshida, Karen K.; Boutilier, Marie

    2005-01-01

    This study explored male adolescents' reasons for participating in moderate and vigorous physical activity, perceived barriers to moderate and vigorous physical activity, and suggestions as to what can be done to increase participation in physical activity. A total of 26 male 15- and 16-year-old adolescents participated in focus group sessions,…

  20. Acquisition of Mathematical Language: Suggestions and Activities for English Language Learners

    ERIC Educational Resources Information Center

    Cirillo, Michelle; Bruna, Katherine Richardson; Herbel-Eisenmann, Beth

    2010-01-01

    In this article, we describe aspects of mathematical language that could be problematic to English-language learners, provide recommendations for teaching English-language learners, and suggest activities intended to foster language development in mathematics. (Contains 1 figure.)

  1. Values in School Science: Some Practical Materials and Suggestions. Third Edition.

    ERIC Educational Resources Information Center

    Brinckerhoff, Richard F.

    The collection of vignettes in this book provide science teachers with a multitude of source materials and useful alternatives for incorporation into their curricula and teaching. Teachers may select topics as brief issues for casual reflection or as a means for promoting deeper investigation and analysis. Most of the vignettes can be extended and…

  2. Suggested Resource and Instructional Materials for Occupational Orientation Classes, Grades 8-12.

    ERIC Educational Resources Information Center

    Illinois State Board of Vocational Education and Rehabilitation, Springfield. Div. of Vocational and Technical Education.

    Sources of instructional materials suitable for occupational orientation classes are listed with addresses. The bibliography, divided between grades 8-9 and grades 10-12, covers books, pamphlets, filmstrips, films, kits, vocational interview tapes, recordings, and texts. Attention is called to articles for vocational guidance from "Changing Times"…

  3. Bringing in the target audience in bystander social marketing materials for communities: suggestions for practitioners.

    PubMed

    Potter, Sharyn J; Stapleton, Jane G

    2011-06-01

    The Know Your Power™ social marketing campaign images model active bystander behaviors that target audience members can use in situations where sexual and relationship violence and stalking are occurring, have occurred, or have the potential to occur. In this practitioner note, we describe strategies that we have used to engage target audience members in the development of the social marketing campaign that we hope can be used by practitioners. We give examples from the development and evaluation of the Know Your Power(TM) social marketing campaign that used focus group and other types of feedback from the target audience to inform the direction of the campaign.

  4. Tractography Activation Patterns in Dorsolateral Prefrontal Cortex Suggest Better Clinical Responses in OCD DBS

    PubMed Central

    Hartmann, Christian J.; Lujan, J. Luis; Chaturvedi, Ashutosh; Goodman, Wayne K.; Okun, Michael S.; McIntyre, Cameron C.; Haq, Ihtsham U.

    2016-01-01

    Background: Medication resistant obsessive-compulsive disorder (OCD) patients can be successfully treated with Deep Brain Stimulation (DBS) which targets the anterior limb of the internal capsule (ALIC) and the nucleus accumbens (NA). Growing evidence suggests that in patients who respond to DBS, axonal fiber bundles surrounding the electrode are activated, but it is currently unknown which discrete pathways are critical for optimal benefit. Our aim was to identify axonal pathways mediating clinical effects of ALIC-NA DBS. Methods: We created computational models of ALIC-NA DBS to simulate the activation of fiber tracts and to identify connected cerebral regions. The pattern of activated axons and their cortical targets was investigated in six OCD patients who underwent ALIC-NA DBS. Results: Modulation of the right anterior middle frontal gyrus (dorsolateral prefrontal cortex) was associated with an excellent response. In contrast, non-responders showed high activation in the orbital part of the right inferior frontal gyrus (lateral orbitofrontal cortex/anterior ventrolateral prefrontal cortex). Factor analysis followed by step-wise linear regression indicated that YBOCS improvement was inversely associated with factors that were predominantly determined by gray matter activation results. Discussion: Our findings support the hypothesis that optimal therapeutic results are associated with the activation of distinct fiber pathways. This suggests that in DBS for OCD, focused stimulation of specific fiber pathways, which would allow for stimulation with lower amplitudes, may be superior to activation of a wide array of pathways, typically associated with higher stimulation amplitudes. PMID:26834544

  5. Factors related to physical activity adherence in women: review and suggestions for future research.

    PubMed

    White, Jennifer L; Ransdell, Lynda B; Vener, Jamie; Flohr, Judith A

    2005-01-01

    Approximately 50 percent of individuals who start an exercise program withdraw within 6 months. Thus, many individuals withdraw before health benefits have been realized. This is a disconcerting statistic considering the well known benefits of physical activity for decreasing risk of hypokinetic diseases and improving quality of life. The literature has suggested a plethora of factors to increase the number of individuals who initiate a physical activity program. However, little is known about the factors that keep women exercising-otherwise known as exercise adherence. The purpose of this paper is to: (a) systematically review the quantitative literature to discern the major factors contributing to adherence to physical activity in women and men and make recommendations for specific gender-based considerations that are important when designing PA interventions for women, and (b) suggest areas of future research related to increasing adherence to physical activity in women. Key factors reviewed in this paper may be useful in developing efficacious physical activity programs for women.

  6. The syndrome of continuous muscle fiber activity. Evidence to suggest proximal neurogenic causation.

    PubMed

    Irani, P F; Purohit, A V; Wadia, N H

    1977-04-01

    Four patients with the syndrome of continuous muscle fiber activity were seen in a period of 6 years. Young females predominated. Remarkable improvement followed phenytoin sodium and carbamazepine administration in three patients, one of whom was "cured" within 4 years. In the remaining patient the response was inconstant. Electromyography showed abnormal spontaneous activity with diphasic and triphasic potentials appearing as doublets and multiplets. Waxing and waning was observed. D-tubocurarine and succinylcholine abolished the spontaneous activity excluding the muscle and the myoneural junction as its source. Spinal anesthesia, thiopental sodium, sleep and baclofen had no effect on it, ruling out a central source. In three patients, nerve blocks at the knee and elbow or wrist abolished this activity pointing to a proximal site of origin in the nerve somewhere between the spinal cord and the nerve block. In the remaining patient such a block significantly reduced but did not abolished the activity suggesting a dual source above and below the block. Finally successive examinations in one of our patients led us to believe that this activity may arise from different sites at varying times. It appears that regardless of the site of origin of the activity in the motor axon the counter part clinical syndrome remains the same. PMID:857572

  7. Electroviscoelastic materials as active dampers

    NASA Astrophysics Data System (ADS)

    Biggerstaff, Janet M.; Kosmatka, John B.

    2002-07-01

    Electroviscoelastic materials (EVEMs) are polymeric materials that exhibit changes in structural properties when a voltage is applied across it. In the current study, an EVEM is developed that produce large changes in stiffness and damping materials with applied voltage. The resulting material exhibits many of the same properties as an electrorheological (ER) material, except the current material is self-supporting and thus can be used to applications where viscoelastic materials are used. The EVEM is composed of three components: 20% (by mass) of poly (p-phenylene) (PPP) particles doped with CuCl2 or FeCl3, 64% of Dow Sylgard 527 silicone gel, and 16% Dow Corning Sylgard 182 silicone elastomer, where the elastomer is added to for stiffening. Experimental harmonic tests using a double-lap shear test and a 0.025 thick specimens between 1 and 150 Hz reveal a factor six increase in stiffening and a factor of three decrease in damping with applied voltage (1500v).

  8. Sporicidal activity of an improved iodide formulation and suggestions regarding the biological safety cabinet.

    PubMed

    Kida, Nori

    2009-06-01

    The sporicidal activity of an improved iodide formulation based on a previously reported agent (Kida et al., 2004, tentatively designated as the KMT reagent) which is composed of 50 mM EDTA-2Na, 50 mM ferric chloride hexahydrate (FeCl3.6H2O), 50 mM potassium iodide (KI) and 50% ethanol in 0.85% NaCl solution at pH 0.3 with hydrochloric acid, was examined in the liquid and vapor phases. The improved iodide formulation subject to distillation (tentatively designated as the distilled KMT reagent: pH around 3) showed comparable sporicidal activity with the KMT reagent. As for the dilution effect, dilution at 1:2 showed more potent sporicidal activity than the undiluted one. It achieved complete disinfection with a treatment for 5 min at 20 degrees C and for 60 min at 5 degrees C. Even at a ratio of 1:100, the dilutions showed significant sporicidal activities at 37 degrees C. The experiment on the disinfection of the biological safety cabinet (Class II type A) as a practical possibility showed that pretreatment with 400 ml of water vapor treatment, and a mixture of 300 ml of this reagent and 150 ml of water in vapor phase achieved complete disinfection after a 24 h-decontamination process. The distilled KMT reagent may be useful for disinfecting against various contaminated materials and sites in both the liquid phase and vapor phase. PMID:19579660

  9. Computational Investigations of Trichoderma Reesei Cel7A Suggest New Routes for Enzyme Activity Improvements

    SciTech Connect

    Beckham, G. T.; Payne, C. M.; Bu, L.; Taylor, C. B.; McCabe, C.; Chu, J. W.; Himmel, M. E.; Crowley, M. F.

    2012-01-01

    The Trichoderma reesei Family 7 cellulase (Cel7A) is a key industrial enzyme in the production of biofuels from lignocellulosic biomass. It is a multi-modular enzyme with a Family 1 carbohydrate-binding module, a flexible O-glycosylated linker, and a large catalytic domain. We have used simulation to elucidate new functions for the 3 sub-domains, which suggests new routes to increase the activity of this central enzyme. These findings include new roles for glycosylation, which we have shown can be used to tune the binding affinity. We have also examined the structures of the catalytically-active complex of Cel7A and its non-processive counterpart, Cel7B, engaged on cellulose, which suggests allosteric mechanisms involved in chain binding when these cellulases are complexed on cellulose. Our computational results also suggest that product inhibition varies significantly between Cel7A and Cel7B, and we offer a molecular-level explanation for this observation. Finally, we discuss simulations of the absolute and relative binding free energy of cellulose ligands and various mutations along the CD tunnel, which will affect processivity and the ability of Cel7A (and related enzymes) to digest cellulose. These results highlight new considerations in protein engineering for processive and non-processive cellulases for production of lignocellulosic biofuels.

  10. The structure of the PERK kinase domain suggests the mechanism for its activation

    SciTech Connect

    Cui, Wenjun; Li, Jingzhi; Ron, David; Sha, Bingdong

    2012-08-31

    The endoplasmic reticulum (ER) unfolded protein response (UPR) is comprised of several intracellular signaling pathways that alleviate ER stress. The ER-localized transmembrane kinase PERK is one of three major ER stress transducers. Oligomerization of PERK's N-terminal ER luminal domain by ER stress promotes PERK trans-autophosphorylation of the C-terminal cytoplasmic kinase domain at multiple residues including Thr980 on the kinase activation loop. Activated PERK phosphorylates Ser51 of the {alpha}-subunit of translation initiation factor 2 (eIF2{alpha}), which inhibits initiation of protein synthesis and reduces the load of unfolded proteins entering the ER. The crystal structure of PERK's kinase domain has been determined to 2.8 {angstrom} resolution. The structure resembles the back-to-back dimer observed in the related eIF2{alpha} kinase PKR. Phosphorylation of Thr980 stabilizes both the activation loop and helix {alpha}G in the C-terminal lobe, preparing the latter for eIF2{alpha} binding. The structure suggests conservation in the mode of activation of eIF2{alpha} kinases and is consistent with a 'line-up' model for PERK activation triggered by oligomerization of its luminal domain.

  11. Organic active materials for batteries

    DOEpatents

    Abouimrane, Ali; Weng, Wei; Amine, Khalil

    2016-08-16

    A rechargeable battery includes a compound having at least two active sites, R.sup.1 and R.sup.2; wherein the at least two active sites are interconnected by one or more conjugated moieties; each active site is coordinated to one or more metal ions M.sup.a+ or each active site is configured to coordinate to one or more metal ions; and "a" is 1, 2, or 3.

  12. Suggested improvements to the standard filter paper assay used to measure cellulase activity.

    PubMed

    Coward-Kelly, Guillermo; Aiello-Mazzari, Cateryna; Kim, Sehoon; Granda, Cesar; Holtzapple, Mark

    2003-06-20

    Two suggestions can be found in the literature to improve the reproducibility of the Mandels' filter paper assay: add supplemental cellobiase and increase the boiling time for color development. Here we provide data that strongly supports adding supplemental cellobiase. Adding supplemental cellobiase increased assay response by 56%. Cellulases from different sources have different cellobiase activities, which would cause significant variation in the assay response. There is no need for additional boiling time-5 minutes is sufficient. For maximum reproducibility, it is essential that the water bath vigorously boil so that temperature excursions are minimized.

  13. Suggested improvements to the standard filter paper assay used to measure cellulase activity.

    PubMed

    Coward-Kelly, Guillermo; Aiello-Mazzari, Cateryna; Kim, Sehoon; Granda, Cesar; Holtzapple, Mark

    2003-06-20

    Two suggestions can be found in the literature to improve the reproducibility of the Mandels' filter paper assay: add supplemental cellobiase and increase the boiling time for color development. Here we provide data that strongly supports adding supplemental cellobiase. Adding supplemental cellobiase increased assay response by 56%. Cellulases from different sources have different cellobiase activities, which would cause significant variation in the assay response. There is no need for additional boiling time-5 minutes is sufficient. For maximum reproducibility, it is essential that the water bath vigorously boil so that temperature excursions are minimized. PMID:12673775

  14. Fractal analysis reveals subclasses of neurons and suggests an explanation of their spontaneous activity.

    PubMed

    Favela, Luis H; Coey, Charles A; Griff, Edwin R; Richardson, Michael J

    2016-07-28

    The present work used fractal time series analysis (detrended fluctuation analysis; DFA) to examine the spontaneous activity of single neurons in an anesthetized animal model, specifically, the mitral cells in the rat main olfactory bulb. DFA bolstered previous research in suggesting two subclasses of mitral cells. Although there was no difference in the fractal scaling of the interspike interval series at the shorter timescales, there was a significant difference at longer timescales. Neurons in Group B exhibited fractal, power-law scaled interspike intervals, whereas neurons in Group A exhibited random variation. These results raise questions about the role of these different cells within the olfactory bulb and potential explanations of their dynamics. Specifically, self-organized criticality has been proposed as an explanation of fractal scaling in many natural systems, including neural systems. However, this theory is based on certain assumptions that do not clearly hold in the case of spontaneous neural activity, which likely reflects intrinsic cell dynamics rather than activity driven by external stimulation. Moreover, it is unclear how self-organized criticality might account for the random dynamics observed in Group A, and how these random dynamics might serve some functional role when embedded in the typical activity of the olfactory bulb. These theoretical considerations provide direction for additional experimental work. PMID:27189719

  15. Activation of porous MOF materials

    SciTech Connect

    Hupp, Joseph T; Farha, Omar K

    2013-04-23

    A method for the treatment of solvent-containing MOF material to increase its internal surface area involves introducing a liquid into the MOF in which liquid the solvent is miscible, subjecting the MOF to supercritical conditions for a time to form supercritical fluid, and releasing the supercritical conditions to remove the supercritical fluid from the MOF. Prior to introducing the liquid into the MOF, occluded reaction solvent, such as DEF or DMF, in the MOF can be exchanged for the miscible solvent.

  16. Activation of porous MOF materials

    SciTech Connect

    Hupp, Joseph T; Farha, Omar K

    2014-04-01

    A method for the treatment of solvent-containing MOF material to increase its internal surface area involves introducing a liquid into the MOF in which liquid the solvent is miscible, subjecting the MOF to supercritical conditions for a time to form supercritical fluid, and releasing the supercritical conditions to remove the supercritcal fluid from the MOF. Prior to introducing the liquid into the MOF, occluded reaction solvent, such as DEF or DMF, in the MOF can be exchanged for the miscible solvent.

  17. Space Resources for Teachers: Chemistry; Including Suggestions for Classroom Activities and Laboratory Experiments.

    ERIC Educational Resources Information Center

    Lawrence, Richard M.

    This publication is composed of 10 units, each based on an area of space science and technology in which chemistry plays an important role. Each resource unit can be used independently of the others and materials can be selected from within a unit. The materials range in difficulty from the junior high level of understanding to those that will…

  18. A Posthypnotic Amnesia: Suggestions of an Active Process in Dissociative Phenomena

    ERIC Educational Resources Information Center

    Coe, William C.; And Others

    1976-01-01

    A retroactive inhibition design was used to examine the process of posthypnotic amnesia. The results supported the notion that "forgotten" material is as available to amnesic subjects at some level as it is to nonamnesic subjects. (Editor)

  19. Suggested Activities on Sociological Health Problems: Drugs, Alcoholism, Smoking for Student Teachers.

    ERIC Educational Resources Information Center

    Samalonis, Bernice

    This is a list of recommendations for a neophyte teacher for discussions with students on drugs, alcoholism, and smoking. Included are suggested readings, suggested questions for the school's drug education coordinator, recommended readings, and New York sources of information. (Related document is SP 006 468.) (JA)

  20. Differential expression of active zone proteins in neuromuscular junctions suggests functional diversification.

    PubMed

    Juranek, Judyta; Mukherjee, Konark; Rickmann, Michael; Martens, Henrik; Calka, Jaroslaw; Südhof, Thomas C; Jahn, Reinhard

    2006-12-01

    Nerve terminals of the central nervous system (CNS) contain specialized release sites for synaptic vesicles, referred to as active zones. They are characterized by electron-dense structures that are tightly associated with the presynaptic plasma membrane and organize vesicle docking and priming sites. Recently, major protein constituents of active zones have been identified, including the proteins Piccolo, Bassoon, RIM, Munc13, ERCs/ELKs/CASTs and liprins. While it is becoming apparent that each of these proteins is essential for synaptic function in the CNS, it is not known to what extent these proteins are involved in synaptic function of the peripheral nervous system. Somatic neuromuscular junctions contain morphologically and functionally defined active zones with similarities to CNS synapses. In contrast, sympathetic neuromuscular varicosities lack active zone-like morphological specializations. Using immunocytochemistry at the light and electron microscopic level we have now performed a systematic investigation of all five major classes of active zone proteins in peripheral neuromuscular junctions. Our results show that somatic neuromuscular endplates contain a full complement of all active zone proteins. In contrast, varicosities of the vas deferens contain a subset of active zone proteins including Bassoon and ELKS2, with the other four components being absent. We conclude that Bassoon and ELKS2 perform independent and specialized functions in synaptic transmission of autonomic synapses.

  1. Comment on Birgegard and Sohlberg's (1999) suggestions for research in subliminal psychodynamic activation.

    PubMed

    Fudin, R

    2000-06-01

    Methodological changes in subliminal psychodynamic activation experiments based on the assumption that multiletter messages can be encoded automatically (Birgegard & Sohlberg, 1999) are questioned. Their contention that partial experimental messages and appropriate nonsense anagram controls (Fudin, 1986) need not be presented in every experiment is supported, with a reservation. If the difference between responses to the complete message and its control is significant in the predicted direction, then Fudin's procedure should be used. A nonsignificant difference between the response to each partial message and its control is needed to support the assumption of proponents of subliminal psychodynamic activation that successful outcomes are effected by the encoding of the meaning of a complete message. Experiments in subliminal psychodynamic activation can be improved if their methodologies take into account variables that may operate when subliminal stimuli are presented and encoded. PMID:10883752

  2. Choosing optimal exposure times for XRF core-scanning: Suggestions based on the analysis of geological reference materials

    NASA Astrophysics Data System (ADS)

    Huang, Jyh-Jaan; Löwemark, Ludvig; Chang, Queenie; Lin, Tzu-Yu; Chen, Huei-Fen; Song, Sheng-Rong; Wei, Kuo-Yen

    2016-04-01

    X-ray fluorescence (XRF) core-scanning is a fast and nondestructive technique to assess elemental variations of unprocessed sediments. However, although the exposure time of XRF-scanning directly affects the scanning counts and total measurement time, only a few studies have considered the influence of exposure time during the scan. How to select an optimal exposure time to achieve reliable results and reduce the total measurement time is an important issue. To address this question, six geological reference materials from the Geological Survey of Japan (JLK-1, JMS-1, JMS-2, JSD-1, JSD-2, and JSD-3) were scanned by the Itrax-XRF core scanner using the Mo- and the Cr-tube with different exposure times to allow a comparison of scanning counts with absolute concentrations. The regression lines and correlation coefficients of elements that are generally used in paleoenvironmental studies were examined for the different exposure times and X-ray tubes. The results show that for those elements with relatively high concentrations or high detectability, the correlation coefficients are higher than 0.90 for all exposure times. In contrast, for the low detectability or low concentration elements, the correlation coefficients are relatively low, and improve little with increased exposure time. Therefore, we suggest that the influence of different exposure times is insignificant for the accuracy of the measurements. Thus, caution must be taken when interpreting the results of elements with low detectability, even when the exposure times are long and scanning counts are reasonably high.

  3. Manifestation of optical activity in different materials

    NASA Astrophysics Data System (ADS)

    Konstantinova, A. F.; Golovina, T. G.; Konstantinov, K. K.

    2014-07-01

    Various manifestations of optical activity (OA) in crystals and organic materials are considered. Examples of optically active enantiomorphic and nonenantiomorphic crystals of 18 symmetry classes are presented. The OA of enantiomorphic organic materials as components of living nature (amino acids, sugars, and proteins) is analyzed. Questions related to the origin of life on earth are considered. Examples of differences in the enantiomers of drugs are shown. The consequences of replacing conventional left-handed amino acids with additionally right-handed amino acids for living organisms are indicated.

  4. Treasury Dept. Suggests Plan to Limit Colleges' Tax Exemption for Business Activities.

    ERIC Educational Resources Information Center

    Jaschik, Scott

    1987-01-01

    Revisions of federal tax law governing the business operations of nonprofit institutions would no longer define a business activity as "related" to the organization's primary mission, and thus tax exempt, solely because it is operated for the convenience of members or students. (MSE)

  5. Effect of cimetidine on catalase activity of Pseudomonas aeruginosa: a suggested mechanism of action.

    PubMed

    Masoud, Masoudeh; Ebrahimi, Farnoosh; Minai-Tehrani, Dariush

    2014-01-01

    Catalase is an important enzyme for the degradation of hydrogen peroxide in cells. Bacteria have potent catalase to deal with H2O2 in their medium culture. Any chemicals that inhibit catalase activity can be harmful for cells. Histamine H2 antagonist drugs such as cimetidine and ranitidine are used for the treatment of gastrointestinal tract disorders. The present results showed that cimetidine could inhibit the catalase activity of Pseudomonas aeruginosa in a competitive inhibition. The determination of IC50 value and Ki (6.5 μM) of cimetidine demonstrated that the enzyme binds to the drug with high affinity. Binding of the drug to the enzyme was pH-dependent and no binding was observed at basic pH (>9) and acidic pH (<6). Moreover, the imidazole ring and cyanoguanidine group of cimetidine may play an important role in inhibition by binding to Fe in heme group and glutamic acid 51 residue on the enzyme, respectively. Ranitidine had no effect on the catalase activity.

  6. Structures of human Bruton's tyrosine kinase in active and inactive conformations suggest a mechanism of activation for TEC family kinases

    SciTech Connect

    Marcotte, Douglas J.; Liu, Yu-Ting; Arduini, Robert M.; Hession, Catherine A.; Miatkowski, Konrad; Wildes, Craig P.; Cullen, Patrick F.; Hong, Victor; Hopkins, Brian T.; Mertsching, Elisabeth; Jenkins, Tracy J.; Romanowski, Michael J.; Baker, Darren P.; Silvian, Laura F.

    2010-11-15

    Bruton's tyrosine kinase (BTK), a member of the TEC family of kinases, plays a crucial role in B-cell maturation and mast cell activation. Although the structures of the unphosphorylated mouse BTK kinase domain and the unphosphorylated and phosphorylated kinase domains of human ITK are known, understanding the kinase selectivity profiles of BTK inhibitors has been hampered by the lack of availability of a high resolution, ligand-bound BTK structure. Here, we report the crystal structures of the human BTK kinase domain bound to either Dasatinib (BMS-354825) at 1.9 {angstrom} resolution or to 4-amino-5-(4-phenoxyphenyl)-7H-pyrrolospyrimidin- 7-yl-cyclopentane at 1.6 {angstrom} resolution. This data provides information relevant to the development of small molecule inhibitors targeting BTK and the TEC family of nonreceptor tyrosine kinases. Analysis of the structural differences between the TEC and Src families of kinases near the Trp-Glu-Ile motif in the N-terminal region of the kinase domain suggests a mechanism of regulation of the TEC family members.

  7. Geopolymers and Related Alkali-Activated Materials

    NASA Astrophysics Data System (ADS)

    Provis, John L.; Bernal, Susan A.

    2014-07-01

    The development of new, sustainable, low-CO2 construction materials is essential if the global construction industry is to reduce the environmental footprint of its activities, which is incurred particularly through the production of Portland cement. One type of non-Portland cement that is attracting particular attention is based on alkali-aluminosilicate chemistry, including the class of binders that have become known as geopolymers. These materials offer technical properties comparable to those of Portland cement, but with a much lower CO2 footprint and with the potential for performance advantages over traditional cements in certain niche applications. This review discusses the synthesis of alkali-activated binders from blast furnace slag, calcined clay (metakaolin), and fly ash, including analysis of the chemical reaction mechanisms and binder phase assemblages that control the early-age and hardened properties of these materials, in particular initial setting and long-term durability. Perspectives for future research developments are also explored.

  8. Activity measurements of radon from construction materials.

    PubMed

    Fior, L; Nicolosi Corrêa, J; Paschuk, S A; Denyak, V V; Schelin, H R; Soreanu Pecequilo, B R; Kappke, J

    2012-07-01

    This work presents the results of radon concentration measurements of construction materials used in the Brazilian industry, such as clay (red) bricks and concrete blocks. The measurements focused on the detection of indoor radon activity during different construction stages and the analysis of radionuclides present in the construction materials. For this purpose, sealed chambers with internal dimensions of approximately 60×60×60 cm3 were built within a protected and isolated laboratory environment, and stable air humidity and temperature levels were maintained. These chambers were also used for radon emanation reduction tests. The chambers were built in four major stages: (1) assembly of the walls using clay (red) bricks, concrete blocks, and mortar; (2) installation of plaster; (3) finishing of wall surface using lime; and (4) insulation of wall surface and finishing using paint. Radon measurements were performed using polycarbonate etched track detectors. By comparing the three layers applied to the masonry walls, it was concluded that only the last step (wall painting using acrylic varnish) reduced the radon emanation, by a factor of approximately 2. Samples of the construction materials (clay bricks and concrete blocks) were ground, homogenized, and subjected to gamma-ray spectrometry analysis to evaluate the activity concentrations of 226Ra, 232Th and 40K. The values for the index of the activity concentration (I), radium equivalent activity (Raeq), and external hazard index (Hext) showed that these construction materials could be used without restrictions or concern about the equivalent dose limit (1 mSv/year).

  9. Characterization of cell death inducing Phytophthora capsici CRN effectors suggests diverse activities in the host nucleus

    PubMed Central

    Stam, Remco; Howden, Andrew J. M.; Delgado-Cerezo, Magdalena; M. M. Amaro, Tiago M.; Motion, Graham B.; Pham, Jasmine; Huitema, Edgar

    2013-01-01

    Plant-Microbe interactions are complex associations that feature recognition of Pathogen Associated Molecular Patterns by the plant immune system and dampening of subsequent responses by pathogen encoded secreted effectors. With large effector repertoires now identified in a range of sequenced microbial genomes, much attention centers on understanding their roles in immunity or disease. These studies not only allow identification of pathogen virulence factors and strategies, they also provide an important molecular toolset suited for studying immunity in plants. The Phytophthora intracellular effector repertoire encodes a large class of proteins that translocate into host cells and exclusively target the host nucleus. Recent functional studies have implicated the CRN protein family as an important class of diverse effectors that target distinct subnuclear compartments and modify host cell signaling. Here, we characterized three necrosis inducing CRNs and show that there are differences in the levels of cell death. We show that only expression of CRN20_624 has an additive effect on PAMP induced cell death but not AVR3a induced ETI. Given their distinctive phenotypes, we assessed localization of each CRN with a set of nuclear markers and found clear differences in CRN subnuclear distribution patterns. These assays also revealed that expression of CRN83_152 leads to a distinct change in nuclear chromatin organization, suggesting a distinct series of events that leads to cell death upon over-expression. Taken together, our results suggest diverse functions carried by CRN C-termini, which can be exploited to identify novel processes that take place in the host nucleus and are required for immunity or susceptibility. PMID:24155749

  10. Immunocalization of telomerase in cells of lizard tail after amputation suggests cell activation for tail regeneration.

    PubMed

    Alibardi, L

    2016-02-01

    Tail amputation (autotomy) in most lizards elicits a remarkable regenerative response leading to a new although simplified tail. No information on the trigger mechanism following wounding is known but cells from the stump initiate to proliferate and form a regenerative blastema. The present study shows that telomerases are mainly activated in the nuclei of various connective and muscle satellite cells of the stump, and in other tissues, probably responding to the wound signals. Western blotting detection also indicates that telomerase positive bands increases in the regenerating blastema in comparison to the normal tail. Light and ultrastructural immunocytochemistry localization of telomerase shows that 4-14 days post-amputation in lizards immunopositive nuclei of sparse cells located among the wounded tissues are accumulating into the forming blastema. These cells mainly include fibroblasts and fat cells of the connective tissue and satellite cells of muscles. Also some immature basophilic and polychromatophilic erytroblasts, lymphoblasts and myelocytes present within the Bone Marrow of the vertebrae show telomerase localization in their nuclei, but their contribution to the formation of the regenerative blastema remains undetermined. The study proposes that one of the initial mechanisms triggering cell proliferation for the formation of the blastema in lizards involve gene activation for the production of telomerase that stimulates the following signaling pathways for cell division and migration.

  11. Antifungal activity in thrips soldiers suggests a dual role for this caste.

    PubMed

    Turnbull, Christine; Caravan, Holly; Chapman, Thomas; Nipperess, David; Dennison, Siobhan; Schwarz, Michael; Beattie, Andrew

    2012-08-23

    The social insect soldier is perhaps the most widely known caste, because it often exhibits spectacular weapons, such as highly enlarged jaws or reinforced appendages, which are used to defend the colony against enemies ranging in size from wasps to anteaters. We examined the function of the enlarged forelimbs of soldiers (both male and female) of the eusocial, gall-inhabiting insect Kladothrips intermedius, and discovered that they have little impact on their ability to repel the specialized invading thrips Koptothrips species. While the efficacy of the enlarged forelimb appears equivocal, we show that soldiers secrete strong antifungal compounds capable of controlling the specialized insect fungal pathogen, Cordyceps bassiana. Our data suggest that these thrips soldiers have evolved in response to selection by both macro- and micro-organisms. While it is unknown whether specialized fungal pathogens have been major selective agents in the evolution of the soldier caste in general, they were probably present when sociality first evolved and may have been the primordial enemies of social insects. PMID:22496077

  12. The neural organization of semantic memory: Electrophysiological activity suggests feature-based segregation

    PubMed Central

    Sitnikova, Tatiana; West, W. Caroline; Kuperberg, Gina R.; Holcomb, Phillip J.

    2007-01-01

    Despite decades of research, it remains controversial whether semantic knowledge is anatomically segregated in the human brain. To address this question, we recorded event-related potentials (ERPs) while participants viewed pictures of animals and tools. Within the 200–600-ms epoch after stimulus presentation, animals (relative to tools) elicited an increased anterior negativity that, based on previous ERP studies, we interpret as associated with semantic processing of visual object attributes. In contrast, tools (relative to animals) evoked an enhanced posterior left-lateralized negativity that, according to prior research, might reflect accessing knowledge of characteristic motion and/or more general functional properties of objects. These results support the hypothesis of the neuroanatomical knowledge organization at the level of object features: the observed neurophysiological activity was modulated by the features that were most salient for object recognition. The high temporal resolution of ERPs allowed us to demonstrate that differences in processing animals and tools occurred specifically within the time-window encompassing semantic analysis. PMID:16129544

  13. Modelling and analysis of bacterial tracks suggest an active reorientation mechanism in Rhodobacter sphaeroides

    PubMed Central

    Rosser, Gabriel; Baker, Ruth E.; Armitage, Judith P.; Fletcher, Alexander G.

    2014-01-01

    Most free-swimming bacteria move in approximately straight lines, interspersed with random reorientation phases. A key open question concerns varying mechanisms by which reorientation occurs. We combine mathematical modelling with analysis of a large tracking dataset to study the poorly understood reorientation mechanism in the monoflagellate species Rhodobacter sphaeroides. The flagellum on this species rotates counterclockwise to propel the bacterium, periodically ceasing rotation to enable reorientation. When rotation restarts the cell body usually points in a new direction. It has been assumed that the new direction is simply the result of Brownian rotation. We consider three variants of a self-propelled particle model of bacterial motility. The first considers rotational diffusion only, corresponding to a non-chemotactic mutant strain. Two further models incorporate stochastic reorientations, describing ‘run-and-tumble’ motility. We derive expressions for key summary statistics and simulate each model using a stochastic computational algorithm. We also discuss the effect of cell geometry on rotational diffusion. Working with a previously published tracking dataset, we compare predictions of the models with data on individual stopping events in R. sphaeroides. This provides strong evidence that this species undergoes some form of active reorientation rather than simple reorientation by Brownian rotation. PMID:24872500

  14. Active Surfaces and Interfaces of Soft Materials

    NASA Astrophysics Data System (ADS)

    Wang, Qiming

    A variety of intriguing surface patterns have been observed on developing natural systems, ranging from corrugated surface of white blood cells at nanometer scales to wrinkled dog skins at millimeter scales. To mimetically harness functionalities of natural morphologies, artificial transformative skin systems by using soft active materials have been rationally designed to generate versatile patterns for a variety of engineering applications. The study of the mechanics and design of these dynamic surface patterns on soft active materials are both physically interesting and technologically important. This dissertation starts with studying abundant surface patterns in Nature by constructing a unified phase diagram of surface instabilities on soft materials with minimum numbers of physical parameters. Guided by this integrated phase diagram, an electroactive system is designed to investigate a variety of electrically-induced surface instabilities of elastomers, including electro-creasing, electro-cratering, electro-wrinkling and electro-cavitation. Combing experimental, theoretical and computational methods, the initiation, evolution and transition of these instabilities are analyzed. To apply these dynamic surface instabilities to serving engineering and biology, new techniques of Dynamic Electrostatic Lithography and electroactive anti-biofouling are demonstrated.

  15. Sixth-Grade Boys' Perceived Benefits of and Barriers to Physical Activity and Suggestions for Increasing Physical Activity

    ERIC Educational Resources Information Center

    Robbins, Lorraine B.; Talley, Henry C.; Wu, Tsu-Yin; Wilbur, JoEllen

    2010-01-01

    Interventions are needed to reduce the high overweight prevalence noted among boys in early high school. Because decreased physical activity (PA) is a factor for weight gain and a decline in boys' PA occurs across the middle school years, a need exists to intervene, as soon as boys reach middle school, to help them get adequate PA. The purpose of…

  16. Active vibration damping using smart material

    NASA Technical Reports Server (NTRS)

    Baras, John S.; Yan, Zhuang

    1994-01-01

    We consider the modeling and active damping of an elastic beam using distributed actuators and sensors. The piezoelectric ceramic material (PZT) is used to build the actuator. The sensor is made of the piezoelectric polymer polyvinylidene fluoride (PVDF). These materials are glued on both sides of the beam. For the simple clamped beam, the closed loop controller has been shown to be able to extract energy from the beam. The shape of the actuator and its influence on the closed loop system performance are discussed. It is shown that it is possible to suppress the selected mode by choosing the appropriate actuator layout. It is also shown that by properly installing the sensor and determining the sensor shape we can further extract and manipulate the sensor signal for our control need.

  17. Design of electro-active polymer gels as actuator materials

    NASA Astrophysics Data System (ADS)

    Popovic, Suzana

    Smart materials, alternatively called active or adaptive, differ from passive materials in their sensing and activation capability. These materials can sense changes in environment such as: electric field, magnetic field, UV light, pH, temperature. They are capable of responding in numerous ways. Some change their stiffness properties (electro-rheological fluids), other deform (piezos, shape memory alloys, electrostrictive materials) or change optic properties (electrochromic polymers). Polymer gels are one of such materials which can change the shape, volume and even optical properties upon different applied stimuli. Due to their low stiffness property they are capable of having up to 100% of strain in a short time, order of seconds. Their motion resembles the one of biosystems, and they are often seen as possible artificial muscle materials. Despite their delicate nature, appropriate design can make them being used as actuator materials which can form controllable surfaces and mechanical switches. In this study several different groups of polymer gel material were investigated: (a) acrylamide based gels are sensitive to pH and electric field and respond in volume change, (b) polyacrylonitrile (PAN) gel is sensitive to pH and electric field and responds in axial strain and bending, (c) polyvinylalcohol (PVA) gel is sensitive to electric field and responds in axial strain and bending and (d) perfluorinated sulfonic acid membrane, Nafion RTM, is sensitive to electric field and responds in bending. Electro-mechanical and chemo-mechanical behavior of these materials is a function of a variety of phenomena: polymer structure, affinity of polymer to the solvent, charge distribution within material, type of solvent, elasticity of polymer matrix, etc. Modeling of this behavior is a task aimed to identify what is driving mechanism for activation and express it in a quantitative way in terms of deformation of material. In this work behavior of the most promising material as

  18. Carbon Nanotube Materials for Substrate Enhanced Control of Catalytic Activity

    SciTech Connect

    Heben, M.; Dillon, A. C.; Engtrakul, C.; Lee, S.-H.; Kelley, R. D.; Kini, A. M.

    2007-05-01

    Carbon SWNTs are attractive materials for supporting electrocatalysts. The properties of SWNTs are highly tunable and controlled by the nanotube's circumferential periodicity and their surface chemistry. These unique characteristics suggest that architectures constructed from these types of carbon support materials would exhibit interesting and useful properties. Here, we expect that the structure of the carbon nanotube support will play a major role in stabilizing metal electrocatalysts under extreme operating conditions and suppress both catalyst and support degradation. Furthermore, the chemical modification of the carbon nanotube surfaces can be expected to alter the interface between the catalyst and support, thus, enhancing the activity and utilization of the electrocatalysts. We plan to incorporate discrete reaction sites into the carbon nanotube lattice to create intimate electrical contacts with the catalyst particles to increase the metal catalyst activity and utilization. The work involves materials synthesis, design of electrode architectures on the nanoscale, control of the electronic, ionic, and mass fluxes, and use of advanced optical spectroscopy techniques.

  19. Energy Crisis. Teaching Resources. A Special Publication Suggesting School Activities Which Stress Individual Responsibility Towards Energy Crisis Problems.

    ERIC Educational Resources Information Center

    Curry, Wendell; And Others

    This handbook provides public school teachers and administrators of Oregon with teaching ideas and information about the energy crisis. Suggested activities are intended to inform students (kindergarten through community college) about their responsibility toward the energy crisis and to motivate energy conservation. The handbook is divided into…

  20. Problems with the Use of Terminology in Genetics Education: 2, Some Examples from Published Materials and Suggestions for Rectifying the Problem.

    ERIC Educational Resources Information Center

    Pearson, J. T.; Hughes, W. J.

    1988-01-01

    Presented is a detailed look at some published materials showing the widespread nature of the misuse of genetics terminology. Suggests that similar problems can be found in any genetics text. Concludes with a plan for urgent action and suggestions for improvement. (Author/CW)

  1. Plasmonic Biofoam: A Versatile Optically Active Material.

    PubMed

    Tian, Limei; Luan, Jingyi; Liu, Keng-Ku; Jiang, Qisheng; Tadepalli, Sirimuvva; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

    2016-01-13

    Owing to their ability to confine and manipulate light at the nanoscale, plasmonic nanostructures are highly attractive for a broad range of applications. While tremendous progress has been made in the synthesis of size- and shape-controlled plasmonic nanostructures, their integration with other materials and application in solid-state is primarily through their assembly on rigid two-dimensional (2D) substrates, which limits the plasmonically active space to a few nanometers above the substrate. In this work, we demonstrate a simple method to create plasmonically active three-dimensional biofoams by integrating plasmonic nanostructures with highly porous biomaterial aerogels. We demonstrate that plasmonic biofoam is a versatile optically active platform that can be harnessed for numerous applications including (i) ultrasensitive chemical detection using surface-enhanced Raman scattering; (ii) highly efficient energy harvesting and steam generation through plasmonic photothermal heating; and (iii) optical control of enzymatic activity by triggered release of biomolecules encapsulated within the aerogel. Our results demonstrate that 3D plasmonic biofoam exhibits significantly higher sensing, photothermal, and loading efficiency compared to conventional 2D counterparts. The design principles and processing methodology of plasmonic aerogels demonstrated here can be broadly applied in the fabrication of other functional foams. PMID:26630376

  2. Photonic crystals with active organic materials

    NASA Astrophysics Data System (ADS)

    Wu, Yeheng

    The concept of photonic crystals, which involves periodically arranged dielectrics that form a new type of material having novel photonic properties, was first proposed about two decades ago. Since then, a number of applications in photonic technology have been explored. Specifically, organic and hybrid photonic crystals are promising because of the unique advantages of the organic materials. A one-dimensional (1D) photonic crystal (multilayer) has high reflectance across a certain wavelength range. We report on studies of 1D multilayer polymer films that were fabricated using spin-coating, free film stacking, and co-extrusion techniques. For example, a stack fabricated by placing a laser dye-doped gain medium between two multilayer reflecting polymer films forms a micro-resonator laser or distributed Bragg laser. The resulting laser system is made entirely of plastic and is only several tens of micrometers in thickness. When the gain, a dye-doped medium, comprises one type of a two-type multilayer film, it results a laser exhibiting distributed feedback. At the edge of the photonic band, the group velocity becomes small and the density of photon states becomes high, which leads to laser emission. Such distributed feedback lasers were fabricated using the co-extrusion technique. The refractive indices and the photonic lattice determine the photonic band gap, which can be tuned by changing these parameters. Materials with Kerr nonlinearity exhibit a change in refractive index depending on the incident intensity of the light. To demonstrate such switching, electrochemical etching techniques on silicon wafers were used to form two-dimensional (2D) photonic crystals. By incorporating the nonlinear organic material into the 2D structure, we have made all-optical switches. The reflection of a beam from the 2D photonic crystal can be controlled by another beam because it induces a refractive index change in the active material by altering the reflection band. A mid

  3. Conducting polymers as active materials in electrochemical capacitors

    NASA Astrophysics Data System (ADS)

    Rudge, Andy; Davey, John; Raistrick, Ian; Gottesfeld, Shimshon; Ferraris, John P.

    Electronically conducting polymer represent an interesting clas of materials for use in electrochemical capacitors thanks to the combination of high capacitive energy density and low materials cost. Three generalized typed of electrochemical capacitors can be constructed using conducting polymers as active material, and in the third of these, which utilized conducting polymers that can be both n- and p-doped, energy densities of up to 39 Wh per kg of active material on both electrodes have been demonstrated. This energy density is obtained using poly-3-(4-fluorophenyl)-thiophene (PEPT) in an electrolyte of 1 M tetramethylammonium trifluoromethanesulfonate (TMATFMS) in acetonitrile. This unique system exhibits reversible n- and p-doping to high charge density in relatively thich films of the active polymer and a cell voltage exceeding 3 V in the fully charged state. Impedance data for both n- and p-doped PFPT suggest that high power densities can be obtained in electrochemical capacitors based on this active conducting polymer.

  4. Activation of Vago by interferon regulatory factor (IRF) suggests an interferon system-like antiviral mechanism in shrimp.

    PubMed

    Li, Chaozheng; Li, Haoyang; Chen, Yixiao; Chen, Yonggui; Wang, Sheng; Weng, Shao-Ping; Xu, Xiaopeng; He, Jianguo

    2015-01-01

    There is a debate on whether invertebrates possess an antiviral immunity similar to the interferon (IFN) system of vertebrates. The Vago gene from arthropods encodes a viral-activated secreted peptide that restricts virus infection through activating the JAK-STAT pathway and is considered to be a cytokine functionally similar to IFN. In this study, the first crustacean IFN regulatory factor (IRF)-like gene was identified in Pacific white shrimp, Litopenaeus vannamei. The L. vannamei IRF showed similar protein nature to mammalian IRFs and could be activated during virus infection. As a transcriptional regulatory factor, L. vannamei IRF could activate the IFN-stimulated response element (ISRE)-containing promoter to regulate the expression of mammalian type I IFNs and initiate an antiviral state in mammalian cells. More importantly, IRF could bind the 5'-untranslated region of L. vannamei Vago4 gene and activate its transcription, suggesting that shrimp Vago may be induced in a similar manner to that of IFNs and supporting the opinion that Vago might function as an IFN-like molecule in invertebrates. These suggested that shrimp might possess an IRF-Vago-JAK/STAT regulatory axis, which is similar to the IRF-IFN-JAK/STAT axis of vertebrates, indicating that invertebrates might possess an IFN system-like antiviral mechanism.

  5. Activation of Vago by interferon regulatory factor (IRF) suggests an interferon system-like antiviral mechanism in shrimp

    PubMed Central

    Li, Chaozheng; Li, Haoyang; Chen, Yixiao; Chen, Yonggui; Wang, Sheng; Weng, Shao-Ping; Xu, Xiaopeng; He, Jianguo

    2015-01-01

    There is a debate on whether invertebrates possess an antiviral immunity similar to the interferon (IFN) system of vertebrates. The Vago gene from arthropods encodes a viral-activated secreted peptide that restricts virus infection through activating the JAK-STAT pathway and is considered to be a cytokine functionally similar to IFN. In this study, the first crustacean IFN regulatory factor (IRF)-like gene was identified in Pacific white shrimp, Litopenaeus vannamei. The L. vannamei IRF showed similar protein nature to mammalian IRFs and could be activated during virus infection. As a transcriptional regulatory factor, L. vannamei IRF could activate the IFN-stimulated response element (ISRE)-containing promoter to regulate the expression of mammalian type I IFNs and initiate an antiviral state in mammalian cells. More importantly, IRF could bind the 5′-untranslated region of L. vannamei Vago4 gene and activate its transcription, suggesting that shrimp Vago may be induced in a similar manner to that of IFNs and supporting the opinion that Vago might function as an IFN-like molecule in invertebrates. These suggested that shrimp might possess an IRF-Vago-JAK/STAT regulatory axis, which is similar to the IRF-IFN-JAK/STAT axis of vertebrates, indicating that invertebrates might possess an IFN system-like antiviral mechanism. PMID:26459861

  6. Structure-function analyses involving palindromic analogs of tritrypticin suggest autonomy of anti-endotoxin and antibacterial activities.

    PubMed

    Kaur, Kanwal J; Sarkar, Pampi; Nagpal, Sushma; Khan, Tarique; Salunke, Dinakar M

    2008-03-01

    Neutralization of invading pathogens by gene-encoded peptide antibiotics has been suggested to manifest in a variety of different modes. Some of these modes require internalization of the peptide through a pathway that involves LPS-mediated uptake of the peptide antibiotics. Many proline/tryptophan-rich cationic peptides for which this mode has been invoked do, indeed, show LPS (endotoxin) binding. If the mechanism of antibiotic action involves the LPS-mediated pathway, a positive correlation ought to manifest between the binding to LPS, its neutralization, and the bacterial killing. No such correlation was evident based on our studies involving minimal active analogs of tritrypticin. The anti-endotoxin activities of these analogs appear not to relate directly to their antibiotic potential. The two palindromic analogs of tritrypticin, NT7 (RRFPWWW) and CT7 (WWWPFRR), showed comparable antibacterial activities. However, while NT7 exhibited anti-endotoxin activity, CT7 did not. The LPS binding of two tritrypticin analogs correlated with their corresponding structures, but the antibacterial activities did not. Further structure-function analysis indicated specific structural implications of the antibacterial activity at the molecular level. Studies involving designed analogs of NT7 incorporating either rigid or flexible linkers between the specifically distanced hydrophobic and cationic clusters modulate the LPS binding. On the other hand, not knowing the target receptor for antibacterial activity is a drawback since the precise epitope for antibacterial activity is not definable. It is apparent that the anti-endotoxin and antibacterial activities represent two independent functions of tritrypticin, consistent with the emerging multifunctionality in the nature of cathelicidins.

  7. Comparative Analysis of the Flax Immune Receptors L6 and L7 Suggests an Equilibrium-Based Switch Activation Model.

    PubMed

    Bernoux, Maud; Burdett, Hayden; Williams, Simon J; Zhang, Xiaoxiao; Chen, Chunhong; Newell, Kim; Lawrence, Gregory J; Kobe, Bostjan; Ellis, Jeffrey G; Anderson, Peter A; Dodds, Peter N

    2016-01-01

    NOD-like receptors (NLRs) are central components of the plant immune system. L6 is a Toll/interleukin-1 receptor (TIR) domain-containing NLR from flax (Linum usitatissimum) conferring immunity to the flax rust fungus. Comparison of L6 to the weaker allele L7 identified two polymorphic regions in the TIR and the nucleotide binding (NB) domains that regulate both effector ligand-dependent and -independent cell death signaling as well as nucleotide binding to the receptor. This suggests that a negative functional interaction between the TIR and NB domains holds L7 in an inactive/ADP-bound state more tightly than L6, hence decreasing its capacity to adopt the active/ATP-bound state and explaining its weaker activity in planta. L6 and L7 variants with a more stable ADP-bound state failed to bind to AvrL567 in yeast two-hybrid assays, while binding was detected to the signaling active variants. This contrasts with current models predicting that effectors bind to inactive receptors to trigger activation. Based on the correlation between nucleotide binding, effector interaction, and immune signaling properties of L6/L7 variants, we propose that NLRs exist in an equilibrium between ON and OFF states and that effector binding to the ON state stabilizes this conformation, thereby shifting the equilibrium toward the active form of the receptor to trigger defense signaling. PMID:26744216

  8. High adenylyl cyclase activity and in vivo cAMP fluctuations in corals suggest central physiological role

    PubMed Central

    Barott, K. L.; Helman, Y.; Haramaty, L.; Barron, M. E.; Hess, K. C.; Buck, J.; Levin, L. R.; Tresguerres, M.

    2013-01-01

    Corals are an ecologically and evolutionarily significant group, providing the framework for coral reef biodiversity while representing one of the most basal of metazoan phyla. However, little is known about fundamental signaling pathways in corals. Here we investigate the dynamics of cAMP, a conserved signaling molecule that can regulate virtually every physiological process. Bioinformatics revealed corals have both transmembrane and soluble adenylyl cyclases (AC). Endogenous cAMP levels in live corals followed a potential diel cycle, as they were higher during the day compared to the middle of the night. Coral homogenates exhibited some of the highest cAMP production rates ever to be recorded in any organism; this activity was inhibited by calcium ions and stimulated by bicarbonate. In contrast, zooxanthellae or mucus had >1000-fold lower AC activity. These results suggest that cAMP is an important regulator of coral physiology, especially in response to light, acid/base disturbances and inorganic carbon levels. PMID:23459251

  9. Magnesium Based Materials and their Antimicrobial Activity

    NASA Astrophysics Data System (ADS)

    Robinson, Duane Allan

    The overall goals of this body of work were to characterize the antimicrobial properties of magnesium (Mg) metal and nano-magnesium oxide (nMgO) in vitro, to evaluate the in vitro cytotoxicity of Mg metal, and to incorporate MgO nanoparticles into a polymeric implant coating and evaluate its in vitro antimicrobial properties. In the course of this work it was found that Mg metal, Mg-mesh, and nMgO have in vitro antimicrobial properties that are similar to a bactericidal antibiotic. For Mg metal, the mechanism of this activity appears to be related to an increase in pH (i.e. a more alkaline environment) and not an increase in Mg2+. Given that Mg-mesh is a Mg metal powder, the assumption is that it has the same mechanism of activity as Mg metal. The mechanism of activity for nMgO remains to be elucidated and may be related to a combination of interaction of the nanoparticles with the bacteria and the alkaline pH. It was further demonstrated that supernatants from suspensions of Mg-mesh and nMgO had the same antimicrobial effect as was noted when the particles were used. The supernatant from Mg-mesh and nMgO was also noted to prevent biofilm formation for two Staphylococcus strains. Finally, poly-epsilon-caprolactone (PCL) composites of Mg-mesh (PCL+Mg-mesh) and nMgO (PCL+nMgO) were produced. Coatings applied to screws inhibited growth of Escherichia coli and Pseudomonas aeruginosa and in thin disc format inhibited the growth of Staphylococcus aureus in addition to the E. coli and P. aeruginosa. Pure Mg metal was noted to have some cytotoxic effect on murine fibroblast and osteoblast cell lines, although this effect needs to be characterized further. To address the need for an in vivo model for evaluating implant associated infections, a new closed fracture osteomyelitis model in the femur of the rat was developed. Magnesium, a readily available and inexpensive metal was shown to have antimicrobial properties that appear to be related to its corrosion products and

  10. Structure of the unliganded form of the proprotein convertase furin suggests activation by a substrate-induced mechanism

    PubMed Central

    Dahms, Sven O.; Arciniega, Marcelino; Steinmetzer, Torsten; Huber, Robert; Than, Manuel E.

    2016-01-01

    Proprotein convertases (PCs) are highly specific proteases required for the proteolytic modification of many secreted proteins. An unbalanced activity of these enzymes is connected to pathologies like cancer, atherosclerosis, hypercholesterolaemia, and infectious diseases. Novel protein crystallographic structures of the prototypical PC family member furin in different functional states were determined to 1.8–2.0 Å. These, together with biochemical data and modeling by molecular dynamics calculations, suggest essential elements underlying its unusually high substrate specificity. Furin shows a complex activation mechanism and exists in at least four defined states: (i) the “off state,” incompatible with substrate binding as seen in the unliganded enzyme; (ii) the active “on state” seen in inhibitor-bound furin; and the respective (iii) calcium-free and (iv) calcium-bound forms. The transition from the off to the on state is triggered by ligand binding at subsites S1 to S4 and appears to underlie the preferential recognition of the four-residue sequence motif of furin. The molecular dynamics simulations of the four structural states reflect the experimental observations in general and provide approximations of the respective stabilities. Ligation by calcium at the PC-specific binding site II influences the active-site geometry and determines the rotamer state of the oxyanion hole-forming Asn295, and thus adds a second level of the activity modulation of furin. The described crystal forms and the observations of different defined functional states may foster the development of new tools and strategies for pharmacological intervention targeting furin. PMID:27647913

  11. Unbalanced activation of glutathione metabolic pathways suggests potential involvement in plant defense against the gall midge Mayetiola destructor in wheat.

    PubMed

    Liu, Xuming; Zhang, Shize; Whitworth, R Jeff; Stuart, Jeffrey J; Chen, Ming-Shun

    2015-01-01

    Glutathione, γ-glutamylcysteinylglycine, exists abundantly in nearly all organisms. Glutathione participates in various physiological processes involved in redox reactions by serving as an electron donor/acceptor. We found that the abundance of total glutathione increased up to 60% in resistant wheat plants within 72 hours following attack by the gall midge Mayetiola destructor, the Hessian fly. The increase in total glutathione abundance, however, is coupled with an unbalanced activation of glutathione metabolic pathways. The activity and transcript abundance of glutathione peroxidases, which convert reduced glutathione (GSH) to oxidized glutathione (GSSG), increased in infested resistant plants. However, the enzymatic activity and transcript abundance of glutathione reductases, which convert GSSG back to GSH, did not change. This unbalanced regulation of the glutathione oxidation/reduction cycle indicates the existence of an alternative pathway to regenerate GSH from GSSG to maintain a stable GSSG/GSH ratio. Our data suggest the possibility that GSSG is transported from cytosol to apoplast to serve as an oxidant for class III peroxidases to generate reactive oxygen species for plant defense against Hessian fly larvae. Our results provide a foundation for elucidating the molecular processes involved in glutathione-mediated plant resistance to Hessian fly and potentially other pests as well. PMID:25627558

  12. A novel fMRI paradigm suggests that pedaling-related brain activation is altered after stroke

    PubMed Central

    Promjunyakul, Nutta-on; Schmit, Brian D.; Schindler-Ivens, Sheila M.

    2015-01-01

    regions were examined separately, reduced brain activation volume reached statistical significance in BA6 [p = 0.04; 4,350 (2,347) μL stroke; 6,938 (3,134) μL control] and cerebellum [p = 0.001; 4,591 (1,757) μL stroke; 8,381 (2,835) μL control]. Regardless of whether activated regions were examined together or separately, there were no significant between-group differences in brain activation intensity [p = 0.17; 1.30 (0.25)% stroke; 1.16 (0.20)% control]. Reduced volume in the stroke group was not observed during lower limb tapping and could not be fully attributed to differences in head motion or movement rate. There was a tendency for pedaling-related brain activation volume to increase with increasing work performed by the paretic limb during pedaling (p = 0.08, r = 0.525). Hence, the results of this study provide two original and important contributions. First, we demonstrated that pedaling can be used with fMRI to examine brain activation associated with lower limb movement in people with stroke. Unlike previous lower limb movements examined with fMRI, pedaling involves continuous, reciprocal, multijoint movement of both limbs. In this respect, pedaling has many characteristics of functional lower limb movements, such as walking. Thus, the importance of our contribution lies in the establishment of a novel paradigm that can be used to understand how the brain adapts to stroke to produce functional lower limb movements. Second, preliminary observations suggest that brain activation volume is reduced during pedaling post-stroke. Reduced brain activation volume may be due to anatomic, physiology, and/or behavioral differences between groups, but methodological issues cannot be excluded. Importantly, brain action volume post-stroke was both task-dependent and mutable, which suggests that it could be modified through rehabilitation. Future work will explore these possibilities. PMID:26089789

  13. A GENOME-WIDE EXPLORATION SUGGESTS AN OLIGOGENIC MODEL OF INHERITANCE FOR THE TAFI ACTIVITY AND ITS ANTIGEN LEVELS

    PubMed Central

    Sabater-Lleal, Maria; Buil, Alfonso; Souto, Juan Carlos; Almasy, Laura; Borrell, Montserrat; Lathrop, Mark; Blangero, John; Fontcuberta, Jordi; Soria, José Manuel

    2008-01-01

    Thrombin-Activatable Fibrinolysis Inhibitor (TAFI) is a protein that attenuates fibrinolysis potently. A considerable proportion of its variability levels is genetically determined. It has been associated with arterial and venous thrombosis. We conducted a genomewide linkage scan for genes affecting variation in plasma TAFI levels in 398 subjects from 21 extended Spanish families. The data were analyzed by a variance-component linkage method. A strong linkage was found on the long arm of Chromosome 13, near the DNA marker D13S156, where the structural gene encoding for TAFI is located. In addition, other new linkage signals were detected on chromosome regions 5p and 7q. More importantly, we performed another multipoint linkage analysis of functional TAFI conditioned on TAFI antigen levels. We detected a strong linkage signal on Chromosome 19 (LOD = 3.0, p = 0.0001) suggesting a novel QTL in this region involved in the specific functional activity of TAFI, regardless of the TAFI antigen levels. One notable aspect of this study is the identification of new QTLs that reveal a clearer picture of the genetic determinants responsible for variation in TAFI levels. Another is the replication of the linkage signal of the CPB2 gene, which confirms an important genetic determinant for TAFI antigen levels. These results strongly suggest an oligogenic mode of inheritance for TAFI, in which CPB2 gene accounts for a proportion of the variation of the phenotype together with other unknown genes that may represent potential risk factors for thrombotic disease. PMID:18563448

  14. Comparison of the White-Nose Syndrome Agent Pseudogymnoascus destructans to Cave-Dwelling Relatives Suggests Reduced Saprotrophic Enzyme Activity

    PubMed Central

    Reynolds, Hannah T.; Barton, Hazel A.

    2014-01-01

    White-nose Syndrome (WNS) is an emerging infectious mycosis that has impacted multiple species of North American bats since its initial discovery in 2006, yet the physiology of the causal agent, the psychrophilic fungus Pseudogymnoascus destructans ( = Geomyces destructans), is not well understood. We investigated the ability of P. destructans to secrete enzymes that could permit environmental growth or affect pathogenesis and compared enzyme activity across several Pseudogymnoascus species isolated from both hibernating bats and cave sediments. We found that P. destructans produced enzymes that could be beneficial in either a pathogenic or saprotrophic context, such as lipases, hemolysins, and urease, as well as chitinase and cellulases, which could aid in saprotrophic growth. The WNS pathogen showed significantly lower activity for urease and endoglucanase compared to con-generic species (Pseudogymnoascus), which may indicate a shift in selective pressure to the detriment of P. destructans’ saprotrophic ability. Based on the positive function of multiple saprotrophic enzymes, the causal agent of White-nose Syndrome shows potential for environmental growth on a variety of substrates found in caves, albeit at a reduced level compared to environmental strains. Our data suggest that if P. destructans emerged as an opportunistic infection from an environmental source, co-evolution with its host may have led to a reduced capacity for saprotrophic growth. PMID:24466096

  15. Comparison of the white-nose syndrome agent Pseudogymnoascus destructans to cave-dwelling relatives suggests reduced saprotrophic enzyme activity.

    PubMed

    Reynolds, Hannah T; Barton, Hazel A

    2014-01-01

    White-nose Syndrome (WNS) is an emerging infectious mycosis that has impacted multiple species of North American bats since its initial discovery in 2006, yet the physiology of the causal agent, the psychrophilic fungus Pseudogymnoascus destructans ( = Geomyces destructans), is not well understood. We investigated the ability of P. destructans to secrete enzymes that could permit environmental growth or affect pathogenesis and compared enzyme activity across several Pseudogymnoascus species isolated from both hibernating bats and cave sediments. We found that P. destructans produced enzymes that could be beneficial in either a pathogenic or saprotrophic context, such as lipases, hemolysins, and urease, as well as chitinase and cellulases, which could aid in saprotrophic growth. The WNS pathogen showed significantly lower activity for urease and endoglucanase compared to con-generic species (Pseudogymnoascus), which may indicate a shift in selective pressure to the detriment of P. destructans' saprotrophic ability. Based on the positive function of multiple saprotrophic enzymes, the causal agent of White-nose Syndrome shows potential for environmental growth on a variety of substrates found in caves, albeit at a reduced level compared to environmental strains. Our data suggest that if P. destructans emerged as an opportunistic infection from an environmental source, co-evolution with its host may have led to a reduced capacity for saprotrophic growth. PMID:24466096

  16. Activation of materials proposed for use in superconducting linac applications

    SciTech Connect

    Hanson, A.L.; Snead, C.L.; Greene, G.A.; Chan, K.C.D.; Safa, H.

    1998-01-01

    Samples of construction materials proposed for use in both superconducting and conventional high-power linear accelerators have been activated with 800 and 2,000 MeV protons to study the decay characteristics of these activated materials. Irradiation times ranged from 10 minutes to 18.67 hours. The decay characteristics of these activated materials were measured and compared to calculated decay curves based on simplified assumptions.

  17. Enhancing activated-peroxide formulations for porous materials :

    SciTech Connect

    Krauter, Paula; Tucker, Mark D.; Tezak, Matthew S.; Boucher, Raymond

    2012-12-01

    During an urban wide-area incident involving the release of a biological warfare agent, the recovery/restoration effort will require extensive resources and will tax the current capabilities of the government and private contractors. In fact, resources may be so limited that decontamination by facility owners/occupants may become necessary and a simple decontamination process and material should be available for this use. One potential process for use by facility owners/occupants would be a liquid sporicidal decontaminant, such as pHamended bleach or activated-peroxide, and simple application devices. While pH-amended bleach is currently the recommended low-tech decontamination solution, a less corrosive and toxic decontaminant is desirable. The objective of this project is to provide an operational assessment of an alternative to chlorine bleach for low-tech decontamination applications activated hydrogen peroxide. This report provides the methods and results for activatedperoxide evaluation experiments. The results suggest that the efficacy of an activated-peroxide decontaminant is similar to pH-amended bleach on many common materials.

  18. Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis

    SciTech Connect

    Firestone, Richard B; Perry, D.L.; English, G.A.; Firestone, R.B.; Leung, K.-N.; Garabedian, G.; Molnar, G.L.; Revay, Zs.

    2008-03-24

    Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed.

  19. Subcaste differences in neural activation suggest a prosocial role for oxytocin in eusocial naked mole-rats.

    PubMed

    Hathaway, Georgia A; Faykoo-Martinez, Mariela; Peragine, Deane E; Mooney, Skyler J; Holmes, Melissa M

    2016-03-01

    The neuropeptide oxytocin (OT) influences prosocial behavior(s), aggression, and stress responsiveness, and these diverse effects are regulated in a species- and context-specific manner. The naked mole-rat (Heterocephalus glaber) is a unique species with which to study context-dependent effects of OT, exhibiting a strict social hierarchy with behavioral specialization within the subordinate caste: soldiers are aggressive and defend colonies against unfamiliar conspecifics while workers are prosocial and contribute to in-colony behaviors such as pup care. To determine if OT is involved in subcaste-specific behaviors, we compared behavioral responses between workers and soldiers of both sexes during a modified resident/intruder paradigm, and quantified activation of OT neurons in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON) using the immediate-early-gene marker c-fos co-localized with OT neurons. Resident workers and soldiers were age-matched with unfamiliar worker stimulus animals as intruders, and encounters were videorecorded and scored for aggressive behaviors. Colony-matched controls were left in their home colony for the duration of the encounters. Brains were extracted and cell counts were conducted for OT immunoreactive (ir), c-fos-ir, and percentage of OT-c-fos double-labeled cells. Results indicate that resident workers were less aggressive but showed greater OT neural activity than soldiers. Furthermore, a linear model including social treatment, cortisol, and subcaste revealed that subcaste was the only significant predictor of OT-c-fos double-labeled cells in the PVN. These data suggest that in naked mole-rats OT promotes prosocial behaviors rather than aggression and that even within subordinates status exerts robust effects on brain and behavior.

  20. Active nematic materials with substrate friction.

    PubMed

    Thampi, Sumesh P; Golestanian, Ramin; Yeomans, Julia M

    2014-12-01

    Active turbulence in dense active systems is characterized by high vorticity on a length scale that is large compared to that of individual entities. We describe the properties of active turbulence as momentum propagation is screened by frictional damping. As friction is increased, the spacing between the walls in the nematic director field decreases as a consequence of the more rapid velocity decays. This leads to, first, a regime with more walls and an increased number of topological defects, and then to a jammed state in which the walls deliminate bands of opposing flow, analogous to the shear bands observed in passive complex fluids. PMID:25615093

  1. Crystal Structures of the Response Regulator DosR From Mycobacterium Tuberculosis Suggest a Helix Rearrangement Mechanism for Phosphorylation Activation

    SciTech Connect

    Wisedchaisri, G.; Wu, M.; Sherman, D.R.; Hol, W.G.J.

    2009-05-26

    The response regulator DosR is essential for promoting long-term survival of Mycobacterium tuberculosis under low oxygen conditions in a dormant state and may be responsible for latent tuberculosis in one-third of the world's population. Here, we report crystal structures of full-length unphosphorylated DosR at 2.2 {angstrom} resolution and its C-terminal DNA-binding domain at 1.7 {angstrom} resolution. The full-length DosR structure reveals several features never seen before in other response regulators. The N-terminal domain of the full-length DosR structure has an unexpected ({beta}{alpha}){sub 4} topology instead of the canonical ({beta}{alpha}){sub 5} fold observed in other response regulators. The linker region adopts a unique conformation that contains two helices forming a four-helix bundle with two helices from another subunit, resulting in dimer formation. The C-terminal domain in the full-length DosR structure displays a novel location of helix {alpha}10, which allows Gln199 to interact with the catalytic Asp54 residue of the N-terminal domain. In contrast, the structure of the DosR C-terminal domain alone displays a remarkable unstructured conformation for helix {alpha}10 residues, different from the well-defined helical conformations in all other known structures, indicating considerable flexibility within the C-terminal domain. Our structures suggest a mode of DosR activation by phosphorylation via a helix rearrangement mechanism.

  2. Biodegradation and biocompatibility of mechanically active magnetoelastic materials

    NASA Astrophysics Data System (ADS)

    Holmes, Hal R.; DeRouin, Andrew; Wright, Samantha; Riedemann, Travor M.; Lograsso, Thomas A.; Rajachar, Rupak M.; Ghee Ong, Keat

    2014-09-01

    Magnetoelastic (ME) materials have many advantages for use as sensors and actuators due to their wireless, passive nature. This paper describes the application of ME materials as biodegradable implants with controllable degradation rates. Experiments have been conducted to show that degradation rates of ME materials are dependent on the material compositions. In addition, it was shown that the degradation rates of the ME materials can be controlled remotely by applying a magnetic field, which causes the ME materials to generate low-magnitude vibrations that hasten their degradation rates. Another concern of ME materials for medical applications is biocompatibility. Indirect cytotoxicity analyses were performed on two types of ME materials: Metglas™ 2826 MB (FeNiMoB) and iron-gallium alloy. While results indicate Metglas is not biocompatible, the degradation products of iron-gallium materials have shown no adverse effects on cell viability. Overall, these results present the possibility of using ME materials as biodegradable, magnetically-controlled active implants.

  3. In vitro antibacterial activity of different pulp capping materials

    PubMed Central

    Beltrami, Riccardo; Colombo, Marco; Ceci, Matteo; Dagna, Alberto; Chiesa, Marco

    2015-01-01

    Background Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont). Material and Methods Streptococcus salivarius, Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrobial activity by the agar disc diffusion test of different pulp capping materials. Paper disks were impregnated whit each pulp capping materials and placed onto culture agar-plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each pulp capping materials were recorded and compared for each bacterial strain. Results For the investigation of the antibacterial properties the ANOVA showed the presence of significant differences among the various materials. Tukey test showed that MTA-based materials induced lower growth inhibition zones. Conclusions MTA-based products show a discrete antibacterial activity varying from calcium hydroxide-based materials which present an higher antibacterial activity. Key words:Agar disc diffusion test, antimicrobial activity, calcium hydroxide, MTA, pulp capping materials. PMID:26644833

  4. Child's Play: An Activities and Materials Handbook.

    ERIC Educational Resources Information Center

    Trencher, Barbara R.

    This handbook, the third printing of the original 1976 edition, presents an eclectic combination of activities gathered from parents and teachers of preschool children, with a focus on the process rather than the product of learning. Its goal is the establishment of positive experiences and sound interpersonal relationships between adults and…

  5. Microscale damping using thin film active materials

    NASA Astrophysics Data System (ADS)

    Kerrigan, Catherine A.; Ho, Ken K.; Mohanchandra, K. P.; Carman, Gregory P.

    2007-04-01

    This paper focuses on understanding and developing a new approach to dampen MEMS structures using both experiments and analytical techniques. Thin film Nitinol and thin film Terfenol-D are evaluated as a damping solution to the micro scale damping problem. Stress induced twin boundary motion in Nitinol is used to passively dampen potentially damaging vibrations. Magnetic domain wall motion is used to passively dampen vibration in Terfenol-D. The thin films of Nitinol, Nitinol/Silicon laminates and Nitinol/Terfenol-D/Nickel laminates have been produced using a sputter deposition process and damping properties have been evaluated. Dynamic testing shows substantial damping (tan δ) measurable in each case. Nitinol film samples were tested in the Differential Scanning Calorimetry (DSC) to determine phase transformation temperatures. The twin boundary mechanism by which energy absorption occurs is present at all points below the Austenite start temperature (approximately 69°C in our film) and therefore allows damping at cold temperatures where traditional materials fail. Thin film in the NiTi/Si laminate was found to produce substantially higher damping (tan δ = 0.28) due to the change in loading condition. The NiTi/Si laminate sample was tested in bending allowing the twin boundaries to be reset by cyclic tensile and compressive loads. The thin film Terfenol-D in the Nitinol/Terfenol-D/Nickel laminate was shown to produce large damping (tan δ = 0.2). In addition to fabricating and testing, an analytical model of a heterogeneous layered thin film damping material was developed and compared to experimental work.

  6. Activation of a photosensitive pharmaceutical agent by a triboluminescent material

    NASA Astrophysics Data System (ADS)

    Yuen, Stacey; Schreyer, Magdalena; Finlay, W. H.; Löbenberg, R.; Moussa, W.

    2006-03-01

    Given the recent emphasis on applications of triboluminescent materials, we investigate the ability of a triboluminescent material to activate a photosensitive pharmaceutical agent. Using compressed sucrose doped with wintergreen, which luminesces when fractured, we demonstrate the activation of riboflavin (vitamin B2), a photosensitizer. A product of activation is the highly reactive singlet oxygen. We add ascorbic acid (vitamin C), an antioxidant, and measure the amount of ascorbic acid oxidation to correlate with the amount of riboflavin activation. Up to 17% ascorbic acid oxidation is observed, indicating triboluminescence is worth exploring as a mechanism for activation of photosensitizers in photodynamic therapy.

  7. Activation of a photosensitive pharmaceutical agent by a triboluminescent material

    SciTech Connect

    Yuen, Stacey; Schreyer, Magdalena; Finlay, W.H.; Loebenberg, R.; Moussa, W.

    2006-03-20

    Given the recent emphasis on applications of triboluminescent materials, we investigate the ability of a triboluminescent material to activate a photosensitive pharmaceutical agent. Using compressed sucrose doped with wintergreen, which luminesces when fractured, we demonstrate the activation of riboflavin (vitamin B2), a photosensitizer. A product of activation is the highly reactive singlet oxygen. We add ascorbic acid (vitamin C), an antioxidant, and measure the amount of ascorbic acid oxidation to correlate with the amount of riboflavin activation. Up to 17% ascorbic acid oxidation is observed, indicating triboluminescence is worth exploring as a mechanism for activation of photosensitizers in photodynamic therapy.

  8. Analysis of Polygenic Mutants Suggests a Role for Mediator in Regulating Transcriptional Activation Distance in Saccharomyces cerevisiae

    PubMed Central

    Reavey, Caitlin T.; Hickman, Mark J.; Dobi, Krista C.; Botstein, David; Winston, Fred

    2015-01-01

    Studies of natural populations of many organisms have shown that traits are often complex, caused by contributions of mutations in multiple genes. In contrast, genetic studies in the laboratory primarily focus on studying the phenotypes caused by mutations in a single gene. However, the single mutation approach may be limited with respect to the breadth and degree of new phenotypes that can be found. We have taken the approach of isolating complex, or polygenic mutants in the lab to study the regulation of transcriptional activation distance in yeast. While most aspects of eukaryotic transcription are conserved from yeast to human, transcriptional activation distance is not. In Saccharomyces cerevisiae, the upstream activating sequence (UAS) is generally found within 450 base pairs of the transcription start site (TSS) and when the UAS is moved too far away, activation no longer occurs. In contrast, metazoan enhancers can activate from as far as several hundred kilobases from the TSS. Previously, we identified single mutations that allow transcription activation to occur at a greater-than-normal distance from the GAL1 UAS. As the single mutant phenotypes were weak, we have now isolated polygenic mutants that possess strong long-distance phenotypes. By identification of the causative mutations we have accounted for most of the heritability of the phenotype in each strain and have provided evidence that the Mediator coactivator complex plays both positive and negative roles in the regulation of transcription activation distance. PMID:26281848

  9. Analysis of Polygenic Mutants Suggests a Role for Mediator in Regulating Transcriptional Activation Distance in Saccharomyces cerevisiae.

    PubMed

    Reavey, Caitlin T; Hickman, Mark J; Dobi, Krista C; Botstein, David; Winston, Fred

    2015-10-01

    Studies of natural populations of many organisms have shown that traits are often complex, caused by contributions of mutations in multiple genes. In contrast, genetic studies in the laboratory primarily focus on studying the phenotypes caused by mutations in a single gene. However, the single mutation approach may be limited with respect to the breadth and degree of new phenotypes that can be found. We have taken the approach of isolating complex, or polygenic mutants in the lab to study the regulation of transcriptional activation distance in yeast. While most aspects of eukaryotic transcription are conserved from yeast to human, transcriptional activation distance is not. In Saccharomyces cerevisiae, the upstream activating sequence (UAS) is generally found within 450 base pairs of the transcription start site (TSS) and when the UAS is moved too far away, activation no longer occurs. In contrast, metazoan enhancers can activate from as far as several hundred kilobases from the TSS. Previously, we identified single mutations that allow transcription activation to occur at a greater-than-normal distance from the GAL1 UAS. As the single mutant phenotypes were weak, we have now isolated polygenic mutants that possess strong long-distance phenotypes. By identification of the causative mutations we have accounted for most of the heritability of the phenotype in each strain and have provided evidence that the Mediator coactivator complex plays both positive and negative roles in the regulation of transcription activation distance.

  10. Alkali-activated cementitious materials: Mechanisms, microstructure and properties

    NASA Astrophysics Data System (ADS)

    Jiang, Weimin

    The goal of this study was to examine the activation reaction, microstructure, properties, identify the mechanisms of activation, and achieve an enhanced understanding of activation processes occurring during the synthesis of alkali activated cementitious materials (AAC). The discussions classify the following categories. (1) alkali activated slag cement; (2) alkali activated portland-slag cement; (3) alkali activated fly ash-slag cement; (4) alkali activated pozzolana-lime cement; (5) alkali activated pozzolana cement. The activators involved are NaOH, KOH; Nasb2SOsb4;\\ Nasb2COsb3;\\ CaSOsb4, and soluble silicate of sodium and potassium. The effect of alkali activation on the microstructure of these materials were analyzed at the micro-nanometer scale by SEM, EDS, ESEM, and TEM. Also sp{29}Si and sp{27}Al MAS-NMR, IR, Raman, TGA, and DTA were performed to characterize the phase in these systems. Slag, fly ash, silica fume, as well as blended cements containing mixtures of these and other components were characterized. A set of ordinary portland cement paste samples served as a control. This study confirmed that AAC materials have great potential because they could generate very early high strength, greater durability and high performance. Among the benefits to be derived from this research is a better understanding of the factors that control concrete properties when using AAC materials, and by controlling the chemistry and processing to produce desired microstructures and properties, as well as their durability.

  11. Nicotinic Activity of Arecoline, the Psychoactive Element of "Betel Nuts", Suggests a Basis for Habitual Use and Anti-Inflammatory Activity.

    PubMed

    Papke, Roger L; Horenstein, Nicole A; Stokes, Clare

    2015-01-01

    Habitual chewing of "betel nut" preparations constitutes the fourth most common human self-administration of a psychoactive substance after alcohol, caffeine, and nicotine. The primary active ingredient in these preparations is arecoline, which comes from the areca nut, the key component of all such preparations. Arecoline is known to be a relatively non-selective muscarinic partial agonist, accounting for many of the overt peripheral and central nervous system effects, but not likely to account for the addictive properties of the drug. We report that arecoline has activity on select nicotinic acetylcholine receptor (nAChR) subtypes, including the two classes of nAChR most related to the addictive properties of nicotine: receptors containing α4 and β2 subunits and those which also contain α6 and β3 subunits. Arecoline is a partial agonist with about 6-10% efficacy for the α4* and α6* receptors expressed in Xenopus oocytes. Additionally, arecoline is a silent agonist of α7 nAChR; while it does not activate α7 receptors when applied alone, it produces substantial activation when co-applied with the positive allosteric modulator PNU-120696. Some α7 silent agonists are effective inhibitors of inflammation, which might account for anti-inflammatory effects of arecoline. Arecoline's activity on nAChR associated with addiction may account for the habitual use of areca nut preparations in spite of the well-documented risk to personal health associated with oral diseases and cancer. The common link between betel and tobacco suggests that partial agonist therapies with cytisine or the related compound varenicline may also be used to aid betel cessation attempts.

  12. Nicotinic Activity of Arecoline, the Psychoactive Element of "Betel Nuts", Suggests a Basis for Habitual Use and Anti-Inflammatory Activity

    PubMed Central

    Papke, Roger L.; Horenstein, Nicole A.; Stokes, Clare

    2015-01-01

    Habitual chewing of "betel nut" preparations constitutes the fourth most common human self-administration of a psychoactive substance after alcohol, caffeine, and nicotine. The primary active ingredient in these preparations is arecoline, which comes from the areca nut, the key component of all such preparations. Arecoline is known to be a relatively non-selective muscarinic partial agonist, accounting for many of the overt peripheral and central nervous system effects, but not likely to account for the addictive properties of the drug. We report that arecoline has activity on select nicotinic acetylcholine receptor (nAChR) subtypes, including the two classes of nAChR most related to the addictive properties of nicotine: receptors containing α4 and β2 subunits and those which also contain α6 and β3 subunits. Arecoline is a partial agonist with about 6–10% efficacy for the α4* and α6* receptors expressed in Xenopus oocytes. Additionally, arecoline is a silent agonist of α7 nAChR; while it does not activate α7 receptors when applied alone, it produces substantial activation when co-applied with the positive allosteric modulator PNU-120696. Some α7 silent agonists are effective inhibitors of inflammation, which might account for anti-inflammatory effects of arecoline. Arecoline's activity on nAChR associated with addiction may account for the habitual use of areca nut preparations in spite of the well-documented risk to personal health associated with oral diseases and cancer. The common link between betel and tobacco suggests that partial agonist therapies with cytisine or the related compound varenicline may also be used to aid betel cessation attempts. PMID:26488401

  13. Advanced low-activation materials. Fibre-reinforced ceramic composites

    NASA Astrophysics Data System (ADS)

    Fenici, P.; Scholz, H. W.

    1994-09-01

    A serious safety and environmental concern for thermonuclear fusion reactor development regards the induced radioactivity of the first wall and structural components. The use of low-activation materials (LAM) in a demonstration reactor would reduce considerably its potential risk and facilitate its maintenance. Moreover, decommissioning and waste management including disposal or even recycling of structural materials would be simplified. Ceramic fibre-reinforced SiC materials offer highly appreciable low activation characteristics in combination with good thermomechanical properties. This class of materials is now under experimental investigation for structural application in future fusion reactors. An overview on the recent results is given, covering coolant leak rates, thermophysical properties, compatibility with tritium breeder materials, irradiation effects, and LAM-consistent purity. SiC/SiC materials present characteristics likely to be optimised in order to meet the fusion application challenge. The scope is to put into practice the enormous potential of inherent safety with fusion energy.

  14. Barriers to and Suggestions for a Healthful, Active Lifestyle as Perceived by Rural and Urban Costa Rican Adolescents

    ERIC Educational Resources Information Center

    Monge-Rojas, Rafael; Garita-Arce, Carlos; Sanchez-Lopez, Marta; Colon-Ramos, Uriyoan

    2009-01-01

    Objective: To assess the perceptions of rural and urban Costa Rican adolescents regarding which barriers and motivators affect their adoption of an active lifestyle. Design: Data were collected in focus group discussions. Participants: 108 male and female adolescents aged 12 to 18 from the 7th to 11th grades. Setting: Two urban and 1 rural high…

  15. Engineering Fluorogen Activating Proteins into Self-Assembling Materials

    PubMed Central

    Saunders, Matthew J.; Liu, Wen; Szent-Gyorgyi, Christopher; Wen, Yi; Drennen, Zachary; Waggoner, Alan S.; Meng, Wilson S.

    2013-01-01

    We present herein characteristics of a conjugate in which dL5, a fluorogen-activating protein (FAP) and AEAEAKAK, an amphiphilic peptide are combined to form a solid-phase fluorescence-detection platform. The FAP dL5 is a covalently linked dimer of two identical light chain variable fragments which activates the fluorescence of the fluorogen malachite green (MG). The amphiphilic peptide of sequence AEAEAKAK is a building block of stimuli-responsive materials that undergoes sol-gel phase transition at high ionic strengths. We hypothesize that the novel bi-functional protein containing both the FAP and the amphiphile, termed dL5_EAK, co-assembles with the self-assembling peptide [AEAEAKAK]2 (EAK16-II) to form an insoluble membrane composite whereby the fluorescence enhancement function of the FAP domain remains intact. Denaturing polyacrylamide electrophoresis indicated that greater than 78% of dL5_EAK incorporates into the EAK16-II membrane. Conversely, less than 32% of dL5 without the EAK sequence associates with the insoluble fraction of EAK16-II in buffers. Membranes containing dL5_EAK and EAK16-II exhibited at least 4-fold higher fluorescence intensity compared to mixtures containing dL5 and EAK16-II. Scanning electron microscopy revealed the presence of particulates, presumably FAPs, scattering on the membrane fibrils. The evidence suggests a system of materials that can be developed into in situ-forming local sensors by immobilizing dL5 into coacervate, on which MG can be detected. It is envisioned that dL5 membranes can be established in diseased locales to monitor infiltration and migration of inflammatory cells marked with antibodies conjugated to MG. PMID:23573960

  16. Calcium alloy as active material in secondary electrochemical cell

    DOEpatents

    Roche, Michael F.; Preto, Sandra K.; Martin, Allan E.

    1976-01-01

    Calcium alloys such as calcium-aluminum and calcium-silicon, are employed as active material within a rechargeable negative electrode of an electrochemical cell. Such cells can use a molten salt electrolyte including calcium ions and a positive electrode having sulfur, sulfides, or oxides as active material. The calcium alloy is selected to prevent formation of molten calcium alloys resulting from reaction with the selected molten electrolytic salt at the cell operating temperatures.

  17. Optically Active Hybrid Materials Constructed from Helically Substituted Polyacetylenes.

    PubMed

    Zhang, Huanyu; Zhao, Biao; Deng, Jianping

    2016-04-01

    Functional materials derived from synthetic helical polymers are attracting increasing interest. Helically substituted polyacetylenes (HSPAs) are especially interesting as typical artificial helical polymers. In recent years, we designed and prepared a series of functional materials based on HSPAs and inorganic materials. The target is to establish some novel hybrid materials that combine the superior properties of both. The examined inorganic materials include silica, graphene, and magnetic Fe3 O4 nanoparticles. Such new functional materials hold great promise and are expected to find practical applications, for instance, as chiral absorbents, chiral sensors, chiral selectors for inducing enantioselective crystallization, chiral catalysts towards asymmetric catalysis, and chiral carriers for enantioselective release. The Personal Account summarizes our major achievements in preparing optically active hybrid materials. We hope it will speed up progress in chiral-related research areas.

  18. Effects of Transcription Elongation Rate and Xrn2 Exonuclease Activity on RNA Polymerase II Termination Suggest Widespread Kinetic Competition.

    PubMed

    Fong, Nova; Brannan, Kristopher; Erickson, Benjamin; Kim, Hyunmin; Cortazar, Michael A; Sheridan, Ryan M; Nguyen, Tram; Karp, Shai; Bentley, David L

    2015-10-15

    The torpedo model of transcription termination asserts that the exonuclease Xrn2 attacks the 5'PO4-end exposed by nascent RNA cleavage and chases down the RNA polymerase. We tested this mechanism using a dominant-negative human Xrn2 mutant and found that it delayed termination genome-wide. Xrn2 nuclease inactivation caused strong termination defects downstream of most poly(A) sites and modest delays at some histone and U snRNA genes, suggesting that the torpedo mechanism is not limited to poly(A) site-dependent termination. A central untested feature of the torpedo model is that there is kinetic competition between the exonuclease and the pol II elongation complex. Using pol II rate mutants, we found that slow transcription robustly shifts termination upstream, and fast elongation extends the zone of termination further downstream. These results suggest that kinetic competition between elongating pol II and the Xrn2 exonuclease is integral to termination of transcription on most human genes. PMID:26474067

  19. The complex structures of isocitrate dehydrogenase from Clostridium thermocellum and Desulfotalea psychrophila suggest a new active site locking mechanism

    PubMed Central

    Leiros, Hanna-Kirsti S.; Fedøy, Anita-Elin; Leiros, Ingar; Steen, Ida Helene

    2012-01-01

    Isocitrate dehydrogenase (IDH) catalyzes the oxidative NAD(P)+-dependent decarboxylation of isocitrate into α-ketoglutarate and CO2 and is present in organisms spanning the biological range of temperature. We have solved two crystal structures of the thermophilic Clostridium thermocellum IDH (CtIDH), a native open apo CtIDH to 2.35 Å and a quaternary complex of CtIDH with NADP+, isocitrate and Mg2+ to 2.5 Å. To compare to these a quaternary complex structure of the psychrophilic Desulfotalea psychrophila IDH (DpIDH) was also resolved to 1.93 Å. CtIDH and DpIDH showed similar global thermal stabilities with melting temperatures of 67.9 and 66.9 °C, respectively. CtIDH represents a typical thermophilic enzyme, with a large number of ionic interactions and hydrogen bonds per residue combined with stabilization of the N and C termini. CtIDH had a higher activity temperature optimum, and showed greater affinity for the substrates with an active site that was less thermolabile compared to DpIDH. The uncompensated negative surface charge and the enlarged methionine cluster in the hinge region both of which are important for cold activity in DpIDH, were absent in CtIDH. These structural comparisons revealed that prokaryotic IDHs in subfamily II have a unique locking mechanism involving Arg310, Asp251′ and Arg255 (CtIDH). These interactions lock the large domain to the small domain and direct NADP+ into the correct orientation, which together are important for NADP+ selectivity. PMID:23650595

  20. The complex structures of isocitrate dehydrogenase from Clostridium thermocellum and Desulfotalea psychrophila suggest a new active site locking mechanism.

    PubMed

    Leiros, Hanna-Kirsti S; Fedøy, Anita-Elin; Leiros, Ingar; Steen, Ida Helene

    2012-01-01

    Isocitrate dehydrogenase (IDH) catalyzes the oxidative NAD(P)(+)-dependent decarboxylation of isocitrate into α-ketoglutarate and CO2 and is present in organisms spanning the biological range of temperature. We have solved two crystal structures of the thermophilic Clostridium thermocellum IDH (CtIDH), a native open apo CtIDH to 2.35 Å and a quaternary complex of CtIDH with NADP(+), isocitrate and Mg(2+) to 2.5 Å. To compare to these a quaternary complex structure of the psychrophilic Desulfotalea psychrophila IDH (DpIDH) was also resolved to 1.93 Å. CtIDH and DpIDH showed similar global thermal stabilities with melting temperatures of 67.9 and 66.9 °C, respectively. CtIDH represents a typical thermophilic enzyme, with a large number of ionic interactions and hydrogen bonds per residue combined with stabilization of the N and C termini. CtIDH had a higher activity temperature optimum, and showed greater affinity for the substrates with an active site that was less thermolabile compared to DpIDH. The uncompensated negative surface charge and the enlarged methionine cluster in the hinge region both of which are important for cold activity in DpIDH, were absent in CtIDH. These structural comparisons revealed that prokaryotic IDHs in subfamily II have a unique locking mechanism involving Arg310, Asp251' and Arg255 (CtIDH). These interactions lock the large domain to the small domain and direct NADP(+) into the correct orientation, which together are important for NADP(+) selectivity.

  1. Low Specific Activity materials concepts are being reevaluated

    SciTech Connect

    Rawl, R.R.

    1993-10-01

    Many types of radioactive low-level waste are classified, packaged, and transported as Low-Specific Activity (LSA) material. The transportation regulations allow LSA materials to be shipped in economical packagings and, under certain conditions, waives compliance with other detailed requirements such as labeling. The fundamental concepts which support the LSA category are being thoroughly reevaluated to determine the defensibility of the provisions. A series of national and international events are leading to the development of new dose models which are likely to fundamentally change the ways these materials are defined. Similar basis changes are likely for the packaging requirements applicable to these materials.

  2. A Drosophila model of GSS syndrome suggests defects in active zones are responsible for pathogenesis of GSS syndrome.

    PubMed

    Choi, Jin-Kyu; Jeon, Yong-Chul; Lee, Dae-Weon; Oh, Jae-Min; Lee, Hyun-Pil; Jeong, Byung-Hoon; Carp, Richard I; Koh, Young Ho; Kim, Yong-Sun

    2010-11-15

    We have established a Drosophila model of Gerstmann-Sträussler-Scheinker (GSS) syndrome by expressing mouse prion protein (PrP) having leucine substitution at residue 101 (MoPrP(P101L)). Flies expressing MoPrP(P101L), but not wild-type MoPrP (MoPrP(3F4)), showed severe defects in climbing ability and early death. Expressed MoPrP(P101L) in Drosophila was differentially glycosylated, localized at the synaptic terminals and mainly present as deposits in adult brains. We found that behavioral defects and early death of MoPrP(P101L) flies were not due to Caspase 3-dependent programmed cell death signaling. In addition, we found that Type 1 glutamatergic synaptic boutons in larval neuromuscular junctions of MoPrP(P101L) flies showed significantly increased numbers of satellite synaptic boutons. Furthermore, the amount of Bruchpilot and Discs large in MoPrP(P101L) flies was significantly reduced. Brains from scrapie-infected mice showed significantly decreased ELKS, an active zone matrix marker compared with those of age-matched control mice. Thus, altered active zone structures at the molecular level may be involved in the pathogenesis of GSS syndrome in Drosophila and scrapie-infected mice.

  3. Fusion materials development program in the broader approach activities

    NASA Astrophysics Data System (ADS)

    Nishitani, T.; Tanigawa, H.; Jitsukawa, S.; Nozawa, T.; Hayashi, K.; Yamanishi, T.; Tsuchiya, K.; Möslang, A.; Baluc, N.; Pizzuto, A.; Hodgson, E. R.; Laesser, R.; Gasparotto, M.; Kohyama, A.; Kasada, R.; Shikama, T.; Takatsu, H.; Araki, M.

    2009-04-01

    Breeding blankets are the most important components in DEMO. The DEMO blanket has to withstand high neutron flux typically 15-30 dpa/year under continuous operation. Therefore integrated and effective development of blanket structural materials and breeding/multiplying materials is essential in the blanket development for DEMO. In parallel to the ITER program, broader approach (BA) activities are initiated by EU and Japan. Based on the common interest of each party towards DEMO, R&D on reduced activation ferritic martensitic (RAFM) steels as a DEMO blanket structural material, SiC f/SiC composites which have potential for use in DEMO blankets, advanced tritium breeders and neutron multiplier for DEMO blankets, and tritium technologies including tritium behavior studies in advanced materials for DEMO blanket applications will be carried out as a part of the BA activities.

  4. Equipment and Materials for Initiating Musical Activities in the Preschool.

    ERIC Educational Resources Information Center

    Miller, Samuel D.

    Music activities are an important part of the preschool experience, yet these activities are often guided by teachers who have had little musical training. Lack of formal music training can be greatly compensated for by access to quality equipment and materials. These resources include a basic accompanying instrument, toy instruments, a durable…

  5. An interactive activation and competition model of person knowledge, suggested by proactive interference by traits spontaneously inferred from behaviours.

    PubMed

    Wang, Yuanbo E; Higgins, Nancy C; Uleman, James S; Michaux, Aaron; Vipond, Douglas

    2016-03-01

    People unconsciously and unintentionally make inferences about others' personality traits based on their behaviours. In this study, a classic memory phenomenon--proactive interference (PI)--is for the first time used to detect spontaneous trait inferences. PI should occur when lists of behaviour descriptions, all implying the same trait, are to be remembered. Switching to a new trait should produce 'release' from proactive interference (or RPI). Results from two experiments supported these predictions. PI and RPI effects are consistent with an interactive activation and competition model of person perception (e.g., McNeill & Burton, 2002, J. Exp. Psychol., 55A, 1141), which predicts categorical organization of social behaviours based on personality traits. Advantages of this model are discussed. PMID:26096621

  6. Evidence suggesting a role for sperm metalloendoprotease activity in penetration of zona-free hamster eggs by human sperm.

    PubMed

    Díaz-Pérez, E; Thomas, P; Meizel, S

    1988-11-01

    It has been reported that metalloendoprotease (MEP) activity is involved in somatic cell membrane fusion events and in the sea urchin sperm acrosome reaction (AR). MEP activity also has been demonstrated in human and other mammalian sperm. The present study was concerned with investigating whether a human sperm MEP is important in membrane events necessary for sperm egg fusion. Ejaculated human sperm were washed, capacitated in vitro, and preincubated with the competitive MEP inhibitors phosphoramidon (50 microM) or CBZ-L-phenylalanine (1 mM), with 100 microM diethylenetriaminepentaacetic acid (DTPA), a heavy metal chelator, or as controls, with the appropriate solvents. The AR was initiated in vitro with preovulatory human follicular fluid and the sperm washed to dilute inhibitors and then coincubated with zona-free golden hamster eggs (zonae and cumuli removed with trypsin and hyaluronidase, respectively). Eggs were washed after 0.5 h, and the number of sperm remaining bound was counted. After 2.5 h further incubation, the eggs were stained with acetolacmoid or acetoorcein and penetration was assayed by counting the number of decondensed sperm heads per egg (penetration index) and the percent of penetrated eggs. The inhibitor treatments did not decrease the percentage of penetrated eggs (range 80-90%), but a significant reduction in the penetration index was observed. Phosphoramidon reduced the penetration index by 45%, CBZ-L-phenylalanine by 57%, and DTPA by 56%. None of the inhibitors decreased the penetration index or the percentage of penetrated eggs when added directly to suspensions of acrosome-reacted sperm and zona-free eggs at the diluted levels that would have been present after washing inhibitor-treated sperm.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Comparative modeling and molecular dynamics suggest high carboxylase activity of the Cyanobium sp. CACIAM14 RbcL protein.

    PubMed

    Siqueira, Andrei Santos; Lima, Alex Ranieri Jerônimo; Dall'Agnol, Leonardo Teixeira; de Azevedo, Juliana Simão Nina; da Silva Gonçalves Vianez, João Lídio; Gonçalves, Evonnildo Costa

    2016-03-01

    Rubisco catalyzes the first step reaction in the carbon fixation pathway, bonding atmospheric CO2/O2 to ribulose 1,5-bisphosphate; it is therefore considered one of the most important enzymes in the biosphere. Genetic modifications to increase the carboxylase activity of rubisco are a subject of great interest to agronomy and biotechnology, since this could increase the productivity of biomass in plants, algae and cyanobacteria and give better yields in crops and biofuel production. Thus, the aim of this study was to characterize in silico the catalytic domain of the rubisco large subunit (rbcL gene) of Cyanobium sp. CACIAM14, and identify target sites to improve enzyme affinity for ribulose 1,5-bisphosphate. A three-dimensional model was built using MODELLER 9.14, molecular dynamics was used to generate a 100 ns trajectory by AMBER12, and the binding free energy was calculated using MM-PBSA, MM-GBSA and SIE methods with alanine scanning. The model obtained showed characteristics of form-I rubisco, with 15 beta sheets and 19 alpha helices, and maintained the highly conserved catalytic site encompassing residues Lys175, Lys177, Lys201, Asp203, and Glu204. The binding free energy of the enzyme-substrate complexation of Cyanobium sp. CACIAM14 showed values around -10 kcal mol(-1) using the SIE method. The most important residues for the interaction with ribulose 1,5-bisphosphate were Arg295 followed by Lys334. The generated model was successfully validated, remaining stable during the whole simulation, and demonstrated characteristics of enzymes with high carboxylase activity. The binding analysis revealed candidates for directed mutagenesis sites to improve rubisco's affinity.

  8. Structure of Epstein-Barr Virus Glycoprotein 42 Suggests a Mechanism for Triggering Receptor-Activated Virus Entry

    SciTech Connect

    Kirschner, Austin N.; Sorem, Jessica; Longnecker, Richard; Jardetzky, Theodore S.

    2009-05-26

    Epstein-Barr virus requires glycoproteins gH/gL, gB, and gp42 to fuse its lipid envelope with B cells. Gp42 is a type II membrane protein consisting of a flexible N-terminal region, which binds gH/gL, and a C-terminal lectin-like domain that binds to the B-cell entry receptor human leukocyte antigen (HLA) class II. Gp42 triggers membrane fusion after HLA binding, a process that requires simultaneous binding to gH/gL and a functional hydrophobic pocket in the lectin domain adjacent to the HLA binding site. Here we present the structure of gp42 in its unbound form. Comparisons to the previously determined structure of a gp42:HLA complex reveals additional N-terminal residues forming part of the gH/gL binding site and structural changes in the receptor binding domain. Although the core of the lectin domain remains similar, significant shifts in two loops and an {alpha} helix bordering the essential hydrophobic pocket suggest a structural mechanism for triggering fusion.

  9. Anthropogenic and temporal components in a complex trigger of type 1 diabetes suggest the active participation of antipyretics.

    PubMed

    Veteikis, Darijus

    2016-08-01

    Tremendous efforts in research without a conclusion on the cause of type 1 diabetes allow the presumption that there is still a blind spot in the development of T1D that is not covered by current hypotheses. The review of geographical knowledge suggests that there is a well-expressed anthropogenic element within the complex environmental trigger of T1D. On the other hand, the initiation of T1D's directed autoimmunity is temporally related to the organism's immune response, induced by entero-viruses, most expectedly. Consequently, the searched for anthropogenic environmental factor is a player temporally linked to enteroviral infections. This paper discusses the participation of antipyretic medicines, and especially paracetamol, with a whole century's history of growing sales and popularity, including indirect influence through phenacetin during the first half of the 20th century. As proposed by several independent studies, the use of pharmaceuticals to reduce fever may counteract with the protective features of the immune system and create favourable conditions for a virus to spread within the organism and damage specific tissue. A preliminary comparison of paracetamol sales with the incidence of T1D data in Lithuania and the other countries in the North-eastern Baltic region supports this hypothesis. PMID:27372871

  10. Molecular multiproxy analysis of ancient root systems suggests strong alteration of deep subsoil organic matter by rhizomicrobial activity

    NASA Astrophysics Data System (ADS)

    Gocke, Martina; Huguet, Arnaud; Derenne, Sylvie; Kolb, Steffen; Wiesenberg, Guido L. B.

    2013-04-01

    decreasing contents of archeal GDGTs from rhizolith via rhizosphere towards root-free loess. Furthermore, the bacterial fingerprint revealed - similar to modern root systems - higher taxonomic diversity in rhizosphere compared to rhizoliths and reference loess. This argues for microorganisms benefiting from root deposits and exudates. Highest concentrations of branched GDGTs in rhizoliths suggest that their source organisms feed on root remains. Incorporation of rhizomicrobial remains as represented by RNA and GDGTs usually affected the sediment at maximum to a distance of 2-3 cm from the former root. FA contents in rhizosphere showed strong scatter and were in part depleted compared to reference loess or, especially in deeper transects, enriched. This indicates the presence of degradation products originating from former rhizosphere processes. Especially at larger depth not affected by modern pedogenic processes, portions of mainly microbial derived C16 homologues were higher in rhizosphere loess up to distances of 10 cm, revealing that the possible extension of the rhizosphere was underestimated so far. In Corg poor subsoil, the occurence of diverse rhizosphere microorganisms and degradation processes even in several centimeters distant from roots point to a strong alteration of OM, possibly contributing to carbon mineralisation.

  11. Long-lived activation products in reactor materials

    SciTech Connect

    Evans, J.C.; Lepel, E.L.; Sanders, R.W.; Wilkerson, C.L.; Silker, W.; Thomas, C.W.; Abel, K.H.; Robertson, D.R.

    1984-08-01

    The purpose of this program was to assess the problems posed to reactor decommissioning by long-lived activation products in reactor construction materials. Samples of stainless steel, vessel steel, concrete, and concrete ingredients were analyzed for up to 52 elements in order to develop a data base of activatable major, minor, and trace elements. Large compositional variations were noted for some elements. Cobalt and niobium concentrations in stainless steel, for example, were found to vary by more than an order of magnitude. A thorough evaluation was made of all possible nuclear reactions that could lead to long lived activation products. It was concluded that all major activation products have been satisfactorily accounted for in decommissioning planning studies completed to date. A detailed series of calculations was carried out using average values of the measured compositions of the appropriate materials to predict the levels of activation products expected in reactor internals, vessel walls, and bioshield materials for PWR and BWR geometries. A comparison is made between calculated activation levels and regulatory guidelines for shallow land disposal according to 10 CFR 61. This analysis shows that PWR and BWR shroud material exceeds the Class C limits and is, therefore, generally unsuitable for near-surface disposal. The PWR core barrel material approaches the Class C limits. Most of the remaining massive components qualify as either Class A or B waste with the bioshield clearly Class A, even at the highest point of activation. Selected samples of activated steel and concrete were subjected to a limited radiochemical analysis program as a verification of the computer model. Reasonably good agreement with the calculations was obtained where comparison was possible. In particular, the presence of /sup 94/Nb in activated stainless steel at or somewhat above expected levels was confirmed.

  12. Active Neutron Interrogation of Non-Radiological Materials with NMIS

    SciTech Connect

    Walker, Mark E; Mihalczo, John T

    2012-02-01

    The Nuclear Materials Identification System (NMIS) at Oak Ridge National Laboratory (ORNL), although primarily designed for analyzing special nuclear material, is capable of identifying nonradiological materials with a wide range of measurement techniques. This report demonstrates four different measurement methods, complementary to fast-neutron imaging, which can be used for material identification: DT transmission, DT scattering, californium transmission, and active time-tagged gamma spectroscopy. Each of the four techniques was used to evaluate how these methods can be used to identify four materials: aluminum, polyethylene, graphite, and G-10 epoxy. While such measurements have been performed individually in the past, in this project, all four measurements were performed on the same set of materials. The results of these measurements agree well with predicted results. In particular, the results of the active gamma spectroscopy measurements demonstrate the technique's applicability in a future version of NMIS which will incorporate passive and active gamma-ray spectroscopy. This system, designated as a fieldable NMIS (FNMIS), is under development by the US Department of Energy Office of Nuclear Verification.

  13. Active thermography in qualitative evaluation of protective materials.

    PubMed

    Gralewicz, Grzegorz; Wiecek, Bogusław

    2009-01-01

    This is a study of the possibilities of a qualitative evaluation of protective materials with active thermography. It presents a simulation of a periodic excitation of a multilayer composite material. Tests were conducted with lock-in thermography on Kevlar composite consisting of 16 layers of Kevlar fabric reinforced with formaldehyde resin with implanted delamination defects. Lock-in thermography is a versatile tool for nondestructive evaluation. It is a fast, remote and nondestructive procedure. Hence, it was used to detect delaminations in the composite structure of materials used in the production of components designed for personal protection. This method directly contributes to an improvement in safety.

  14. On the propagation of Voigt waves in energetically active materials

    NASA Astrophysics Data System (ADS)

    Mackay, Tom G.; Lakhtakia, Akhlesh

    2016-11-01

    If Voigt-wave propagation is possible in a dissipative anisotropic dielectric material characterised by the permittivity dyadic \\mathop{\\varepsilon }\\limits\\raise{2pt=}, then it is also possible in the analogous energetically active material characterised by the permittivity dyadic \\mathop{\\tilde{\\varepsilon }}\\limits\\raise{2pt=}, where \\mathop{\\tilde{\\varepsilon }}\\limits\\raise{2pt=} is the hermitian conjugate of \\mathop{\\varepsilon }\\limits\\raise{2pt=}. This symmetry follows directly from a theoretical analysis of the necessary and sufficient conditions for Voigt-wave propagation in anisotropic materials. As a consequence of this symmetry, a porous dissipative material that exhibits Voigt-wave propagation can be used to construct a material that allows the propagation of Voigt waves with attendant linear gain in amplitude with propagation distance, by means of infiltration with an electrically or optically activated dye, for example. This phenomenon is captured by the Bruggeman formalism for homogenised composite materials based on isotropic dielectric component materials that are randomly distributed as oriented spheroidal particles.

  15. Material Flows in an Active Nematic Liquid Crystal

    NASA Astrophysics Data System (ADS)

    Decamp, Stephen; Redner, Gabriel; Baskaran, Aparna; Hagan, Michael; Dogic, Zvonimir

    Active matter systems are composed of energy consuming constituent components which drive far-from-equilibrium dynamics. As such, active materials exhibit energetic states which would be unfavorable in passive, equilibrium materials. We study one such material; an active nematic liquid crystal which exists in a dynamical steady state where +/-1/2 defects are continuously generated and annihilated at a constant rate. The active nematic is composed of micron-sized microtubule filaments which are highly concentrated into a quasi-2D film that resides on an oil-water interface. Kinesin motor proteins drive inter-filament sliding which results in net extensile motion of the microtubule film. Notably, we find a mesophase in which motile +1/2 defects, acquire system-spanning orientational order. Currently, we are tracking material flows generated by the active stresses in the system to measure length scales at which energy is dissipated, and to measure the relation between internally generated flows and bend in the nematic field.

  16. Mechanical Activation of Construction Binder Materials by Various Mills

    NASA Astrophysics Data System (ADS)

    Fediuk, R. S.

    2016-04-01

    The paper deals with the mechanical grinding down to the nano powder of construction materials. During mechanical activation a composite binder active molecules cement minerals occur in the destruction of the molecular defects in the areas of packaging and breaking metastable phase decompensation intermolecular forces. The process is accompanied by a change in the kinetics of hardening of portland cement. Mechanical processes during grinding mineral materials cause, along with the increase in their surface energy, increase the Gibbs energy of powders and, respectively, their chemical activity, which also contributes to the high adhesion strength when contacting them with binders. Thus, the set of measures for mechanical activation makes better use of the weight of components filled with cement systems and adjust their properties. At relatively low cost is possible to provide a spectacular and, importantly, easily repeatable results in a production environment.

  17. People* Working . . . *Especially Women . . . A Book of Materials, Activities, and Ideas for the Classroom Teacher.

    ERIC Educational Resources Information Center

    Valiant, Sharon

    This bibliography lists publications and other media, historical facts, and suggestions for activities that show women as working and accomplishing people. Materials are from all grade levels (K-12) and many subject areas. Arrangement is in three sections. Part I deals with women who have worked but not for wages, the pioneer, the homemaker, and…

  18. Nonlinear active materials: an illustration of controllable phase matchability.

    PubMed

    Lu, Hongcheng; Gautier, Romain; Donakowski, Martin D; Tran, T Thao; Edwards, Bryce W; Nino, Juan C; Halasyamani, P Shiv; Liu, Zhengtang; Poeppelmeier, Kenneth R

    2013-08-14

    For a crystal to exhibit nonlinear optical (NLO) activity such as second-harmonic generation (SHG), it must belong to a noncentrosymmetric (NCS) space group. Moreover, for these nonlinear optical (NLO) materials to be suitable for practical uses, the synthesized crystals should be phase-matchable (PM). Previous synthetic research into SHG-active crystals has centered on (i) how to create NCS compounds and/or (ii) how to obtain NCS compounds with high SHG efficiencies. With these tactics, one can synthesize a material with a high SHG efficiency, but the material could be unusable if the material was nonphase-matchable (non-PM). To probe the origin of phase matchability of NCS structures, we present two new chemically similar hybrid compounds within one composition space: (I) [Hdpa]2NbOF5·2H2O and (II) HdpaNbOF4 (dpa = 2,2'-dipyridylamine). Both compounds are NCS and chemically similar, but (I) is non-PM while (II) is PM. Our results indicate--consistent with organic crystallography--the arrangement of the organic molecule within hybrid materials dictates whether the material is PM or non-PM.

  19. Spontaneous Motion in Hierarchically Assembled Active Cellular Materials

    NASA Astrophysics Data System (ADS)

    Chen, Daniel

    2013-03-01

    With exquisite precision and reproducibility, cells orchestrate the cooperative action of thousands of nanometer-sized molecular motors to carry out mechanical tasks at much larger length scales, such as cell motility, division and replication. Besides their biological importance, such inherently far-from-equilibrium processes are an inspiration for the development of soft materials with highly sought after biomimetic properties such as autonomous motility and self-healing. I will describe our exploration of such a class of biologically inspired soft active materials. Starting from extensile bundles comprised of microtubules and kinesin, we hierarchically assemble active analogs of polymeric gels, liquid crystals and emulsions. At high enough concentration, microtubule bundles form an active gel network capable of generating internally driven chaotic flows that enhance transport and fluid mixing. When confined to emulsion droplets, these 3D networks buckle onto the water-oil interface forming a dense thin film of bundles exhibiting cascades of collective buckling, fracture, and self-healing driven by internally generated stresses from the kinesin clusters. When compressed against surfaces, this active nematic cortex exerts traction stresses that propel the locomotion of the droplet. Taken together, these observations exemplify how assemblies of animate microscopic objects exhibit collective biomimetic properties that are fundamentally distinct from those found in materials assembled from inanimate building blocks. These assemblies, in turn, enable the generation of a new class of materials that exhibit macroscale flow phenomena emerging from nanoscale components.

  20. The Empirical Attitude, Material Practice and Design Activities

    ERIC Educational Resources Information Center

    Apedoe, Xornam; Ford, Michael

    2010-01-01

    This article is an argument about something that is both important and severely underemphasized in most current science curricula. The empirical attitude, fundamental to science since Galileo, is a habit of mind that motivates an active search for feedback on our ideas from the material world. Although more simple views of science manifest the…

  1. Characterization of surface active materials derived from farm products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface active materials obtained by chemical modification of plant protein isolates (lupin, barley, oat), corn starches (dextrin, normal, high amylose, and waxy) and soybean oil (soybean oil based polysoaps, SOPS) were investigated for their surface and interfacial properties using axisymmetric dro...

  2. Getting Started: Materials and Equipment for Active Learning Preschools.

    ERIC Educational Resources Information Center

    Vogel, Nancy

    This book provides information to guide the development of an active learning early childhood program by assisting in the selection of materials and equipment to support children's cognitive, physical and social development. The guide considers the arrangement of classroom areas, and elements of the daily routine. The following classroom interest…

  3. Transport of biologically active material in laser cutting.

    PubMed

    Frenz, M; Mathezloic, F; Stoffel, M H; Zweig, A D; Romano, V; Weber, H P

    1988-01-01

    The transport of biologically active material during laser cutting with CO2 and Er lasers is demonstrated. This transport mechanism removes particles from the surface of gelatin, agar, and liver samples into the depth of the laser-formed craters. The transport phenomenon is explained by a contraction and condensation of enclosed hot water vapor. We show by cultivating transported bacteria in agar that biological particles can survive the shock of the transport. Determination of the numbers of active cells evidences a more pronounced activity of the cultivated bacteria after impact with an Er laser than with a CO2 laser.

  4. Comparison of activation effects in {gamma}-ray detector materials

    SciTech Connect

    Truscott, P.R.; Evans, H.E.; Dyer, C.S.; Peerless, C.L.; Flatman, J.C.; Cosby, M.; Knight, P.; Moss, C.E.

    1996-06-01

    Activation induced by cosmic and trapped radiation in {gamma}-ray detector materials represents a significant source of background for space-based detector systems. Selection of detector materials should therefore include consideration of this background source. Results are presented from measurements of induced radioactivity in different scintillators activated either as a result of irradiation by mono-energetic protons at accelerator facilities, or flight on board the Space Shuttle. Radiation transport computer codes are used to help compare the effects observed from the scintillators, by identifying and quantifying the influence on the background spectra from more than one hundred of the radionuclides produced by spallation. For the space experiment data, the simulation results also permit determination of the contributions to detector activation from the different sources of radiation in the Shuttle cabin.

  5. Activation of a Ca-bentonite as buffer material

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Hsing; Chen, Wen-Chuan

    2016-04-01

    Swelling behavior is an important criterion in achieving the low-permeability sealing function of buffer material. A potential buffer material may be used for radioactive waste repository in Taiwan is a locally available clayey material known as Zhisin clay, which has been identified as a Ca-bentonite. Due to its Ca-based origin, Zhisin was found to exhibit swelling capacity much lower than that of Na-bentonite. To enhance the swelling potential of Zhisin clay, a cation exchange process by addition of Na2CO3 powder was introduced in this paper. The addition of Na2CO3 reagent to Zhisin clay, in a liquid phase, caused the precipitation of CaCO3 and thereby induced a replacement of Ca2+ ions by Na+ ions on the surface of bentonite. Characterization test conducted on Zhisin clay includes chemical analysis, cation exchange capacity, X-ray diffraction, and thermogravimetry (TG). Free-swelling test apparatus was developed according to International Society of Rock Mechanics recommendations. A series of free-swelling tests were conducted on untreated and activated specimens to characterize the effect of activation on the swelling capacity of Zhisin clay. Efforts were made to determine an optimum dosage for the activation, and to evaluate the aging effect. Also, the activated material was evaluated for its stability in various hydrothermal conditions for potential applications as buffer material in a repository. Experimental results show that Na2CO3-activated Zhisin clay is superior in swelling potential to untreated Zhisin clay. Also, there exists an optimum amount of activator in terms of improvements in the swelling capacity. A distinct time-swell relationship was discovered for activated Zhisin clay. The corresponding mechanism refers to exchange of cations and breakdown of quasi-crystal, which results in ion exchange hysteresis of Ca-bentonite. Due to the ion exchange hysteresis, activated bentonite shows a post-rise time-swell relationship different than the sigmoid

  6. Activation of accelerator construction materials by heavy ions

    NASA Astrophysics Data System (ADS)

    Katrík, P.; Mustafin, E.; Hoffmann, D. H. H.; Pavlovič, M.; Strašík, I.

    2015-12-01

    Activation data for an aluminum target irradiated by 200 MeV/u 238U ion beam are presented in the paper. The target was irradiated in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. The purpose of the experiment was to study the role of primary particles, projectile fragments, and target fragments in the activation process using the depth profiling of residual activity. The study brought information on which particles contribute dominantly to the target activation. The experimental data were compared with the Monte Carlo simulations by the FLUKA 2011.2c.0 code. This study is a part of a research program devoted to activation of accelerator construction materials by high-energy (⩾200 MeV/u) heavy ions at GSI Darmstadt. The experimental data are needed to validate the computer codes used for simulation of interaction of swift heavy ions with matter.

  7. Research in active composite materials and structures: an overview

    NASA Astrophysics Data System (ADS)

    Garg, Devendra P.; Anderson, Gary L.

    2000-06-01

    During the past several years, the Materials Science Division and the Mechanical and Environmental Sciences Division of the Army Research Office have been supporting projects focusing on basic resaserch in the area of smart materials and structures. The major emphasis of the ARO Structures and Dynamics Program has been on the theoretical, computational, and experimental analysis of smart structures and structural dynamics, damping, active control, and health monitoring as applied to rotor craft, electromagnetic antenna structures, missiles, land vehicles, and weapon systems. The research projects supported by the program have been primarily directed towards improving the ability to predict, control, and optimize the dynamic response of complex, multi-body deformable structures. The projects in the field of smart materials and structures have included multi-disciplinary research conducted by teams of several faculty members as well as research performed by individual investigators.

  8. Module Design, Materials, and Packaging Research Team: Activities and Capabilities

    SciTech Connect

    McMahon, T. J.; del Cueto, J.; Glick, S.; Jorgensen, G.; Kempe, M.; Kennedy, C.; Pern, J.; Terwilliger, K

    2005-01-01

    Our team activities are directed at improving PV module reliability by incorporating new, more effective, and less expensive packaging materials and techniques. New and existing materials or designs are evaluated before and during accelerated environmental exposure for the following properties: (1) Adhesion and cohesion: peel strength and lap shear. (2) Electrical conductivity: surface, bulk, interface and transients. (3) Water vapor transmission: solubility and diffusivity. (4) Accelerated weathering: ultraviolet, temperature, and damp heat tests. (5) Module and cell failure diagnostics: infrared imaging, individual cell shunt characterization, coring. (6) Fabrication improvements: SiOxNy barrier coatings and enhanced wet adhesion. (7) Numerical modeling: Moisture ingress/egress, module and cell performance, and cell-to-frame leakage current. (8) Rheological properties of polymer encapsulant and sheeting materials. Specific examples will be described.

  9. Electro-active material (EAM) based bend sensors

    NASA Astrophysics Data System (ADS)

    LaComb, Ronald; LaComb, Julie

    2010-04-01

    The capability to accurately estimate strain and orientation of cables in an undersea environment is important for a multitude of applications. One way to estimate the positional location of a submersed cable is to utilize a network of distributed bend sensors providing inputs to a curve fitting algorithm. In this work commercially available bend sensors are characterized for small deflections. In addition proto-type devices are presented which can potentially improve device sensitivity. Commercially available bend sensors are based upon electro-active materials and variable resistance materials. Electro-active materials (EAM) are known for their actuator functionality but certain EAMs are capable of sensing as well. New advances in materials such as Ionic Polymer Metal Composites (IPMC) are proving suitable for quasi-static sensor applications. These sensors are low power, conformal and produce directionally dependent output voltages which are linearly proportional to deflection, with voltage polarity representative of the deflection direction. IPMCs are capable of being morphed for increased sensitivity. Variable resistivity sensors are based on smart epoxy polymer and carbon loaded inks. These sensors are inexpensive and conformal and unlike EAMs provide static measurements.

  10. Positive Active Material For Alkaline Electrolyte Storage Battert Nickel Electrodes

    DOEpatents

    Bernard, Patrick; Baudry, Michelle

    2000-12-05

    A method of manufacturing a positive active material for nickel electrodes of alkaline storage batteries which consists of particles of hydroxide containing mainly nickel and covered with a layer of a hydroxide phase based on nickel and yttrium is disclosed. The proportion of the hydroxide phase is in the range 0.15% to 3% by weight of yttrium expressed as yttrium hydroxide relative to the total weight of particles.

  11. Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities

    SciTech Connect

    Morrison, G.C.; Corsi, R.L.; Destaillats, H.; Nazaroff, W.W.; Wells, J.R.

    2006-05-01

    Chemical processes taking place in indoor environments can significantly alter the nature and concentrations of pollutants. Exposure to secondary contaminants generated in these reactions needs to be evaluated in association with many aspects of buildings to minimize their impact on occupant health and well-being. Focusing on indoor ozone chemistry, we describe alternatives for improving indoor air quality by controlling chemical changes related to building materials, ventilation systems, and occupant activities.

  12. Final Report: Imaging of Buried Nanoscale Optically Active Materials

    SciTech Connect

    Appelbaum, Ian

    2011-07-05

    This is a final report covering work done at University of Maryland to develop a Ballistic Electron Emission Luminescence (BEEL) microscope. This technique was intended to examine the carrier transport and photon emission in deeply buried optically-active layers and thereby provide a means for materials science to unmask the detailed consequences of experimentally controllable growth parameters, such as quantum dot size, statistics and orientation, and defect density and charge recombination pathways.

  13. Using DFT Methods to Study Activators in Optical Materials

    SciTech Connect

    Du, Mao-Hua

    2015-08-17

    Density functional theory (DFT) calculations of various activators (ranging from transition metal ions, rare-earth ions, ns2 ions, to self-trapped and dopant-bound excitons) in phosphors and scintillators are reviewed. As a single-particle ground-state theory, DFT calculations cannot reproduce the experimentally observed optical spectra, which involve transitions between multi-electronic states. However, DFT calculations can generally provide sufficiently accurate structural relaxation and distinguish different hybridization strengths between an activator and its ligands in different host compounds. This is important because the activator-ligand interaction often governs the trends in luminescence properties in phosphors and scintillators, and can be used to search for new materials. DFT calculations of the electronic structure of the host compound and the positions of the activator levels relative to the host band edges in scintillators are also important for finding optimal host-activator combinations for high light yields and fast scintillation response. Mn4+ activated red phosphors, scintillators activated by Ce3+, Eu2+, Tl+, and excitons are shown as examples of using DFT calculations in phosphor and scintillator research.

  14. Using DFT Methods to Study Activators in Optical Materials

    DOE PAGES

    Du, Mao-Hua

    2015-08-17

    Density functional theory (DFT) calculations of various activators (ranging from transition metal ions, rare-earth ions, ns2 ions, to self-trapped and dopant-bound excitons) in phosphors and scintillators are reviewed. As a single-particle ground-state theory, DFT calculations cannot reproduce the experimentally observed optical spectra, which involve transitions between multi-electronic states. However, DFT calculations can generally provide sufficiently accurate structural relaxation and distinguish different hybridization strengths between an activator and its ligands in different host compounds. This is important because the activator-ligand interaction often governs the trends in luminescence properties in phosphors and scintillators, and can be used to search for new materials.more » DFT calculations of the electronic structure of the host compound and the positions of the activator levels relative to the host band edges in scintillators are also important for finding optimal host-activator combinations for high light yields and fast scintillation response. Mn4+ activated red phosphors, scintillators activated by Ce3+, Eu2+, Tl+, and excitons are shown as examples of using DFT calculations in phosphor and scintillator research.« less

  15. Anti-inflammation activities of mycosporine-like amino acids (MAAs) in response to UV radiation suggest potential anti-skin aging activity.

    PubMed

    Suh, Sung-Suk; Hwang, Jinik; Park, Mirye; Seo, Hyo Hyun; Kim, Hyoung-Shik; Lee, Jeong Hun; Moh, Sang Hyun; Lee, Taek-Kyun

    2014-10-14

    Certain photosynthetic marine organisms have evolved mechanisms to counteract UV-radiation by synthesizing UV-absorbing compounds, such as mycosporine-like amino acids (MAAs). In this study, MAAs were separated from the extracts of marine green alga Chlamydomonas hedleyi using HPLC and were identified as porphyra-334, shinorine, and mycosporine-glycine (mycosporine-Gly), based on their retention times and maximum absorption wavelengths. Furthermore, their structures were confirmed by triple quadrupole MS/MS. Their roles as UV-absorbing compounds were investigated in the human fibroblast cell line HaCaT by analyzing the expression levels of genes associated with antioxidant activity, inflammation, and skin aging in response to UV irradiation. The mycosporine-Gly extract, but not the other MAAs, had strong antioxidant activity in the 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Furthermore, treatment with mycosporine-Gly resulted in a significant decrease in COX-2 mRNA levels, which are typically increased in response to inflammation in the skin, in a concentration-dependent manner. Additionally, in the presence of MAAs, the UV-suppressed genes, procollagen C proteinase enhancer (PCOLCE) and elastin, which are related to skin aging, had increased expression levels equal to those in UV-mock treated cells. Interestingly, the increased expression of involucrin after UV exposure was suppressed by treatment with the MAAs mycosporine-Gly and shinorine, but not porphyra-334. This is the first report investigating the biological activities of microalgae-derived MAAs in human cells.

  16. Active-Site-Accessible, Porphyrinic Metal;#8722;Organic Framework Materials

    SciTech Connect

    Farha, Omar K.; Shultz, Abraham M.; Sarjeant, Amy A.; Nguyen, SonBinh T.; Hupp, Joseph T.

    2012-02-06

    On account of their structural similarity to cofactors found in many metallo-enzymes, metalloporphyrins are obvious potential building blocks for catalytically active, metal-organic framework (MOF) materials. While numerous porphyrin-based MOFs have already been described, versions featuring highly accessible active sites and permanent microporosity are remarkably scarce. Indeed, of the more than 70 previously reported porphyrinic MOFs, only one has been shown to be both permanently microporous and contain internally accessible active sites for chemical catalysis. Attempts to generalize the design approach used in this single successful case have failed. Reported here, however, is the synthesis of an extended family of MOFs that directly incorporate a variety of metalloporphyrins (specifically Al{sup 3+}, Zn{sup 2+}, Pd{sup 2+}, Mn{sup 3+}, and Fe{sup 3+} complexes). These robust porphyrinic materials (RPMs) feature large channels and readily accessible active sites. As an illustrative example, one of the manganese-containing RPMs is shown to be catalytically competent for the oxidation of alkenes and alkanes.

  17. Form and pattern of MUC1 expression on T cells activated in vivo or in vitro suggests a function in T-cell migration

    PubMed Central

    Correa, Isabel; Plunkett, Tim; Vlad, Anda; Mungul, Arron; Candelora-Kettel, Jessica; Burchell, Joy M; Taylor–papadimitriou, Joyce; Finn, Olivera J

    2003-01-01

    MUC1 is a transmembrane mucin that is expressed on ductal epithelial cells and epithelial malignancies and has been proposed as a target antigen for immunotherapy. The expression of MUC1 has recently been reported on T and B cells. In this study we demonstrate that following activation in vivo or activation by different stimuli in vitro, human T cells expressed MUC1 at the cell surface. However, the level of expression in activated human T cells was significantly lower than that seen on normal epithelial cells or on breast cancer cells. In contrast, resting T cells did not bind MUC1-specific monoclonal antibodies (mAbs), nor was MUC1 mRNA detectable by reverse transcription–polymerase chain reaction (RT–PCR) or Northern blot analysis in these cells. The profile of activated T-cell reactivity with different MUC1-specific antibodies suggested that the glycoform of MUC1 expressed by the activated T cells carried core 2-based O-glycans, as opposed to the core 1 structures that dominate in the cancer-associated mucin. Confocal microscopy revealed that MUC1 was uniformly distributed on the surface of activated T cells. However, when the cells were polarized in response to a migratory chemokine, MUC1 was found on the leading edge rather than on the uropod, where other large mucin-like molecules on T cells are trafficked. The concentration of MUC1 at the leading edge of polarized activated human T cells suggests that MUC1 could be involved in early interactions between T cells and endothelial cells at inflammatory sites. PMID:12519300

  18. Antimicrobial activity of filling materials used in primary teeth pulpotomy.

    PubMed

    Pimenta, Hévelin Couto; Borges, Álvaro Henrique; Bandeca, Matheus Coelho; Neves, Ana Thereza Sabóia; Fontes, Rodrigo Gusmão; da Silva, Priscila Vieira; Aranha, Andreza Maria Fábio

    2015-04-01

    The aim of this study was to investigate the antibacterial activity of pulp capping materials used in primary teeth (formocresol [FC], zinc oxide and eugenol cement [ZOE], ZOE mixed with FC [ZOEFC], mineral trioxide aggregate [MTA] and calcium hydroxide [CH]) against cariogenic bacteria. The agar plate diffusion test was used for the cultures, including saline solution as a negative control. A base layer of 15 mL of brain heart infusion agar was inoculated with 300 mL of each inoculum. Twelve wells were made and completely filled with one of the testing materials for each bacteria strain. The plates were incubated at 37°C for 48 h. Zones of microbial inhibition and material diffusion were measured and photographed. The results obtained were analyzed by Kruskal-Wallis and Mann-Whitney non-parametric tests. Respectively, the medium zones of bacteria inhibition of FC, ZOE, ZOEFC, MTA and CH against Streptococcus mutans growth were 28.5, 15.2, 20.8, 9.3 and 11.6; against Lactobacillus acidophilus growth were 28.7, 14.8, 15.3, 15.2 and 20.0, and against Actinomyces viscosus growth were 13.6, 13.5, 14.7, 10.0 and 13.6. We might confirmed the high antibacterial activity of FC solution, especially against S. mutans and L. acidophilus, as wells as, the low inhibitory effect of MTA cement on the cariogenic bacteria studied.

  19. Antimicrobial Activity of Filling Materials Used in Primary Teeth Pulpotomy

    PubMed Central

    Pimenta, Hévelin Couto; Borges, Álvaro Henrique; Bandeca, Matheus Coelho; Neves, Ana Thereza Sabóia; Fontes, Rodrigo Gusmão; da Silva, Priscila Vieira; Aranha, Andreza Maria Fábio

    2015-01-01

    The aim of this study was to investigate the antibacterial activity of pulp capping materials used in primary teeth (formocresol [FC], zinc oxide and eugenol cement [ZOE], ZOE mixed with FC [ZOEFC], mineral trioxide aggregate [MTA] and calcium hydroxide [CH]) against cariogenic bacteria. The agar plate diffusion test was used for the cultures, including saline solution as a negative control. A base layer of 15 mL of brain heart infusion agar was inoculated with 300 mL of each inoculum. Twelve wells were made and completely filled with one of the testing materials for each bacteria strain. The plates were incubated at 37°C for 48 h. Zones of microbial inhibition and material diffusion were measured and photographed. The results obtained were analyzed by Kruskal–Wallis and Mann–Whitney non-parametric tests. Respectively, the medium zones of bacteria inhibition of FC, ZOE, ZOEFC, MTA and CH against Streptococcus mutans growth were 28.5, 15.2, 20.8, 9.3 and 11.6; against Lactobacillus acidophilus growth were 28.7, 14.8, 15.3, 15.2 and 20.0, and against Actinomyces viscosus growth were 13.6, 13.5, 14.7, 10.0 and 13.6. We might confirmed the high antibacterial activity of FC solution, especially against S. mutans and L. acidophilus, as wells as, the low inhibitory effect of MTA cement on the cariogenic bacteria studied. PMID:25954072

  20. Vibration attenuation of aircraft structures utilizing active materials

    NASA Astrophysics Data System (ADS)

    Agnes, Gregory S.; Whitehouse, Stephen R.; Mackaman, John R.

    1993-09-01

    The need for active vibration control for airborne laser systems was demonstrated during the late 1970s by the Airborne Laser Laboratory. Other possible applications include sonic fatigue alleviation, reduction of buffet induced fatigue, vibration control for embedded antennae, and active aeroelastic control. The purpose of this paper is to present an overview of active vibration control technology and its application to aircraft. Classification of classic aircraft vibration problems and currently available solutions are used to provide a framework for the study. Current solutions are classified as being either passive or active and by the methodology (modal modification or addition) used to reduce vibration. Possible applications for this technology in aircraft vibration control are presented within this framework to demonstrate the increased versatility active materials technologies provide the designer. An in- depth study of an active pylon to reduce wing/store vibration is presented as an example. Finally, perceived gaps in the existing technology base are identified and both on-going and future research plans in these areas are discussed.

  1. Design of Responsive and Active (Soft) Materials Using Liquid Crystals.

    PubMed

    Bukusoglu, Emre; Bedolla Pantoja, Marco; Mushenheim, Peter C; Wang, Xiaoguang; Abbott, Nicholas L

    2016-06-01

    Liquid crystals (LCs) are widely known for their use in liquid crystal displays (LCDs). Indeed, LCDs represent one of the most successful technologies developed to date using a responsive soft material: An electric field is used to induce a change in ordering of the LC and thus a change in optical appearance. Over the past decade, however, research has revealed the fundamental underpinnings of potentially far broader and more pervasive uses of LCs for the design of responsive soft material systems. These systems involve a delicate interplay of the effects of surface-induced ordering, elastic strain of LCs, and formation of topological defects and are characterized by a chemical complexity and diversity of nano- and micrometer-scale geometry that goes well beyond that previously investigated. As a reflection of this evolution, the community investigating LC-based materials now relies heavily on concepts from colloid and interface science. In this context, this review describes recent advances in colloidal and interfacial phenomena involving LCs that are enabling the design of new classes of soft matter that respond to stimuli as broad as light, airborne pollutants, bacterial toxins in water, mechanical interactions with living cells, molecular chirality, and more. Ongoing efforts hint also that the collective properties of LCs (e.g., LC-dispersed colloids) will, over the coming decade, yield exciting new classes of driven or active soft material systems in which organization (and useful properties) emerges during the dissipation of energy. PMID:26979412

  2. Design of Responsive and Active (Soft) Materials Using Liquid Crystals.

    PubMed

    Bukusoglu, Emre; Bedolla Pantoja, Marco; Mushenheim, Peter C; Wang, Xiaoguang; Abbott, Nicholas L

    2016-06-01

    Liquid crystals (LCs) are widely known for their use in liquid crystal displays (LCDs). Indeed, LCDs represent one of the most successful technologies developed to date using a responsive soft material: An electric field is used to induce a change in ordering of the LC and thus a change in optical appearance. Over the past decade, however, research has revealed the fundamental underpinnings of potentially far broader and more pervasive uses of LCs for the design of responsive soft material systems. These systems involve a delicate interplay of the effects of surface-induced ordering, elastic strain of LCs, and formation of topological defects and are characterized by a chemical complexity and diversity of nano- and micrometer-scale geometry that goes well beyond that previously investigated. As a reflection of this evolution, the community investigating LC-based materials now relies heavily on concepts from colloid and interface science. In this context, this review describes recent advances in colloidal and interfacial phenomena involving LCs that are enabling the design of new classes of soft matter that respond to stimuli as broad as light, airborne pollutants, bacterial toxins in water, mechanical interactions with living cells, molecular chirality, and more. Ongoing efforts hint also that the collective properties of LCs (e.g., LC-dispersed colloids) will, over the coming decade, yield exciting new classes of driven or active soft material systems in which organization (and useful properties) emerges during the dissipation of energy.

  3. Active Neutron Interrogation to Detect Shielded Fissionable Material

    SciTech Connect

    D. L. Chichester; E. H. Seabury

    2009-05-01

    Portable electronic neutron generators (ENGs) may be used to interrogate suspicious items to detect, characterize, and quantify the presence fissionable material based upon the measurement of prompt and/or delayed emissions of neutrons and/or photons resulting from fission. The small size (<0.2 m3), light weight (<12 kg), and low power consumption (<50 W) of modern ENGs makes them ideally suited for use in field situations, incorporated into systems carried by 2-3 individuals under rugged conditions. At Idaho National Laboratory we are investigating techniques and portable equipment for performing active neutron interrogation of moderate sized objects less than ~2-4 m3 to detect shielded fissionable material. Our research in this area relies upon the use of pulsed deuterium-tritium ENGs and the measurement of die-away prompt fission neutrons and other neutron signatures in-between neutron pulses from the ENG and after the ENG is turned off.

  4. The feasibility of recycling and clearance of active materials from fusion power plants

    NASA Astrophysics Data System (ADS)

    Zucchetti, M.; El-Guebaly, L. A.; Forrest, R. A.; Marshall, T. D.; Taylor, N. P.; Tobita, K.

    2007-08-01

    In order to minimize the quantity of active materials that require long-term storage, arising during operation and after fusion power plant decommissioning, maximum use should be made of both recycling within the nuclear industry and clearance. For the latter, revised limits have been recently issued at the international level and in the US and Europe. In this paper the implications for fusion materials of these new levels are considered. Concerning recycling, power plant studies have employed criteria based solely on radiological parameters. Reviews of remote procedures currently used within the nuclear industry suggest that these criteria have been unduly conservative and should be revised.

  5. Active Printed Materials for Complex Self-Evolving Deformations

    NASA Astrophysics Data System (ADS)

    Raviv, Dan; Zhao, Wei; McKnelly, Carrie; Papadopoulou, Athina; Kadambi, Achuta; Shi, Boxin; Hirsch, Shai; Dikovsky, Daniel; Zyracki, Michael; Olguin, Carlos; Raskar, Ramesh; Tibbits, Skylar

    2014-12-01

    We propose a new design of complex self-evolving structures that vary over time due to environmental interaction. In conventional 3D printing systems, materials are meant to be stable rather than active and fabricated models are designed and printed as static objects. Here, we introduce a novel approach for simulating and fabricating self-evolving structures that transform into a predetermined shape, changing property and function after fabrication. The new locally coordinated bending primitives combine into a single system, allowing for a global deformation which can stretch, fold and bend given environmental stimulus.

  6. Active printed materials for complex self-evolving deformations.

    PubMed

    Raviv, Dan; Zhao, Wei; McKnelly, Carrie; Papadopoulou, Athina; Kadambi, Achuta; Shi, Boxin; Hirsch, Shai; Dikovsky, Daniel; Zyracki, Michael; Olguin, Carlos; Raskar, Ramesh; Tibbits, Skylar

    2014-12-18

    We propose a new design of complex self-evolving structures that vary over time due to environmental interaction. In conventional 3D printing systems, materials are meant to be stable rather than active and fabricated models are designed and printed as static objects. Here, we introduce a novel approach for simulating and fabricating self-evolving structures that transform into a predetermined shape, changing property and function after fabrication. The new locally coordinated bending primitives combine into a single system, allowing for a global deformation which can stretch, fold and bend given environmental stimulus.

  7. Active millimeter wave detection of concealed layers of dielectric material

    NASA Astrophysics Data System (ADS)

    Bowring, N. J.; Baker, J. G.; Rezgui, N. D.; Southgate, M.; Alder, J. F.

    2007-04-01

    Extensive work has been published on millimetre wave active and passive detection and imaging of metallic objects concealed under clothing. We propose and demonstrate a technique for revealing the depth as well as the outline of partially transparent objects, which is especially suited to imaging layer materials such as explosives and drugs. The technique uses a focussed and scanned FMCW source, swept through many GHz to reveal this structure. The principle involved is that a parallel sided dielectric slab produces reflections at both its upper and lower surfaces, acting as a Fabry-Perot interferometer. This produces a pattern of alternating reflected peaks and troughs in frequency space. Fourier or Burg transforming this pattern into z-space generates a peak at the thickness of the irradiated sample. It could be argued that though such a technique may work for single uniform slabs of dielectric material, it will give results of little or no significance when the sample both scatters the incident radiation and gives erratic reflectivities due to its non-uniform thickness and permittivity . We show results for a variety of materials such as explosive simulants, powder and drugs, both alone and concealed under clothing or in a rucksack, which display strongly directional reflectivities at millimeter wavelengths, and whose location is well displayed by a varying thickness parameter as the millimetre beam is scanned across the target. With this system we find that samples can easily be detected at standoff distances of at least 4.6m.

  8. Potential active materials for photo-supercapacitor: A review

    NASA Astrophysics Data System (ADS)

    Ng, C. H.; Lim, H. N.; Hayase, S.; Harrison, I.; Pandikumar, A.; Huang, N. M.

    2015-11-01

    The need for an endless renewable energy supply, typically through the utilization of solar energy in most applications and systems, has driven the expansion, versatility, and diversification of marketed energy storage devices. Energy storage devices such as hybridized dye-sensitized solar cell (DSSC)-capacitors and DSSC-supercapacitors have been invented for energy reservation. The evolution and vast improvement of these devices in terms of their efficiencies and flexibilities have further sparked the invention of the photo-supercapacitor. The idea of coupling a DSSC and supercapacitor as a complete energy conversion and storage device arose because the solar energy absorbed by dye molecules can be efficiently transferred and converted to electrical energy by adopting a supercapacitor as the energy delivery system. The conversion efficiency of a photo-supercapacitor is mainly dependent on the use of active materials during its fabrication. The performances of the dye, photoactive metal oxide, counter electrode, redox electrolyte, and conducting polymer are the primary factors contributing to high-energy-efficient conversion, which enhances the performance and shelf-life of a photo-supercapacitor. Moreover, the introduction of compact layer as a primary adherent film has been earmarked as an effort in enhancing power conversion efficiency of solar cell. Additionally, the development of electrolyte-free solar cell such as the invention of hole-conductor or perovskite solar cell is currently being explored extensively. This paper reviews and analyzes the potential active materials for a photo-supercapacitor to enhance the conversion and storage efficiencies.

  9. Materials and Process Activities for NASA's Composite Crew Module

    NASA Technical Reports Server (NTRS)

    Polis, Daniel L.

    2012-01-01

    In January 2007, the NASA Administrator and Associate Administrator for the Exploration Systems Mission Directorate chartered the NASA Engineering and Safety Center (NESC) to design, build, and test a full-scale Composite Crew Module (CCM). The overall goal of the CCM project was to develop a team from the NASA family with hands-on experience in composite design, manufacturing, and testing in anticipation of future space exploration systems being made of composite materials. The CCM project was planned to run concurrently with the Orion project s baseline metallic design within the Constellation Program so that features could be compared and discussed without inducing risk to the overall Program. The materials and process activities were prioritized based on a rapid prototype approach. This approach focused developmental activities on design details with greater risk and uncertainty, such as out-of-autoclave joining, over some of the more traditional lamina and laminate building block levels. While process development and associated building block testing were performed, several anomalies were still observed at the full-scale level due to interactions between process robustness and manufacturing scale-up. This paper describes the process anomalies that were encountered during the CCM development and the subsequent root cause investigations that led to the final design solutions. These investigations highlight the importance of full-scale developmental work early in the schedule of a complex composite design/build project.

  10. Genes Upregulated in Winter Wheat (Triticum aestivum L.) during Mild Freezing and Subsequent Thawing Suggest Sequential Activation of Multiple Response Mechanisms.

    PubMed

    Skinner, Daniel Z

    2015-01-01

    Exposing fully cold-acclimated wheat plants to a mild freeze-thaw cycle of -3 °C for 24h followed by +3 °C for 24 or 48 h results in dramatically improved tolerance of subsequent exposure to sub-freezing temperatures. Gene enrichment analysis of crown tissue from plants collected before or after the -3 °C freeze or after thawing at +3 °C for 24 or 48 h revealed that many biological processes and molecular functions were activated during the freeze-thaw cycle in an increasing cascade of responses such that over 150 processes or functions were significantly enhanced by the end of the 48 h, post-freeze thaw. Nearly 2,000 individual genes were upregulated more than 2-fold over the 72 h course of freezing and thawing, but more than 70% of these genes were upregulated during only one of the time periods examined, suggesting a series of genes and gene functions were involved in activation of the processes that led to enhanced freezing tolerance. This series of functions appeared to include extensive cell signaling, activation of stress response mechanisms and the phenylpropanoid biosynthetic pathway, extensive modification of secondary metabolites, and physical restructuring of cell membranes. By identifying plant lines that are especially able to activate these multiple mechanisms it may be possible to develop lines with enhanced winterhardiness.

  11. Hypnosis, suggestion, and suggestibility: an integrative model.

    PubMed

    Lynn, Steven Jay; Laurence, Jean-Roch; Kirsch, Irving

    2015-01-01

    This article elucidates an integrative model of hypnosis that integrates social, cultural, cognitive, and neurophysiological variables at play both in and out of hypnosis and considers their dynamic interaction as determinants of the multifaceted experience of hypnosis. The roles of these variables are examined in the induction and suggestion stages of hypnosis, including how they are related to the experience of involuntariness, one of the hallmarks of hypnosis. It is suggested that studies of the modification of hypnotic suggestibility; cognitive flexibility; response sets and expectancies; the default-mode network; and the search for the neurophysiological correlates of hypnosis, more broadly, in conjunction with research on social psychological variables, hold much promise to further understanding of hypnosis.

  12. Manipulating lipid bilayer material properties using biologically active amphipathic molecules

    NASA Astrophysics Data System (ADS)

    Ashrafuzzaman, Md; Lampson, M. A.; Greathouse, D. V.; Koeppe, R. E., II; Andersen, O. S.

    2006-07-01

    Lipid bilayers are elastic bodies with properties that can be manipulated/controlled by the adsorption of amphipathic molecules. The resulting changes in bilayer elasticity have been shown to regulate integral membrane protein function. To further understand the amphiphile-induced modulation of bilayer material properties (thickness, intrinsic monolayer curvature and elastic moduli), we examined how an enantiomeric pair of viral anti-fusion peptides (AFPs)—Z-Gly-D-Phe and Z-Gly-Phe, where Z denotes a benzyloxycarbonyl group, as well as Z-Phe-Tyr and Z-D-Phe-Phe-Gly—alters the function of enantiomeric pairs of gramicidin channels of different lengths in planar bilayers. For both short and long channels, the channel lifetimes and appearance frequencies increase as linear functions of the aqueous AFP concentration, with no apparent effect on the single-channel conductance. These changes in channel function do not depend on the chirality of the channels or the AFPs. At pH 7.0, the relative changes in channel lifetimes do not vary when the channel length is varied, indicating that these compounds exert their effects primarily by causing a positive-going change in the intrinsic monolayer curvature. At pH 4.0, the AFPs are more potent than at pH 7.0 and have greater effects on the shorter channels, indicating that these compounds now change the bilayer elastic moduli. When AFPs of different anti-fusion potencies are compared, the rank order of the anti-fusion activity and the channel-modifying activity is similar, but the relative changes in anti-fusion potency are larger than the changes in channel-modifying activity. We conclude that gramicidin channels are useful as molecular force transducers to probe the influence of small amphiphiles upon lipid bilayer material properties.

  13. Suggested Involvement of PP1/PP2A Activity and De Novo Gene Expression in Anhydrobiotic Survival in a Tardigrade, Hypsibius dujardini, by Chemical Genetic Approach.

    PubMed

    Kondo, Koyuki; Kubo, Takeo; Kunieda, Takekazu

    2015-01-01

    Upon desiccation, some tardigrades enter an ametabolic dehydrated state called anhydrobiosis and can survive a desiccated environment in this state. For successful transition to anhydrobiosis, some anhydrobiotic tardigrades require pre-incubation under high humidity conditions, a process called preconditioning, prior to exposure to severe desiccation. Although tardigrades are thought to prepare for transition to anhydrobiosis during preconditioning, the molecular mechanisms governing such processes remain unknown. In this study, we used chemical genetic approaches to elucidate the regulatory mechanisms of anhydrobiosis in the anhydrobiotic tardigrade, Hypsibius dujardini. We first demonstrated that inhibition of transcription or translation drastically impaired anhydrobiotic survival, suggesting that de novo gene expression is required for successful transition to anhydrobiosis in this tardigrade. We then screened 81 chemicals and identified 5 chemicals that significantly impaired anhydrobiotic survival after severe desiccation, in contrast to little or no effect on survival after high humidity exposure only. In particular, cantharidic acid, a selective inhibitor of protein phosphatase (PP) 1 and PP2A, exhibited the most profound inhibitory effects. Another PP1/PP2A inhibitor, okadaic acid, also significantly and specifically impaired anhydrobiotic survival, suggesting that PP1/PP2A activity plays an important role for anhydrobiosis in this species. This is, to our knowledge, the first report of the required activities of signaling molecules for desiccation tolerance in tardigrades. The identified inhibitory chemicals could provide novel clues to elucidate the regulatory mechanisms underlying anhydrobiosis in tardigrades.

  14. Suggested Involvement of PP1/PP2A Activity and De Novo Gene Expression in Anhydrobiotic Survival in a Tardigrade, Hypsibius dujardini, by Chemical Genetic Approach

    PubMed Central

    Kondo, Koyuki; Kubo, Takeo; Kunieda, Takekazu

    2015-01-01

    Upon desiccation, some tardigrades enter an ametabolic dehydrated state called anhydrobiosis and can survive a desiccated environment in this state. For successful transition to anhydrobiosis, some anhydrobiotic tardigrades require pre-incubation under high humidity conditions, a process called preconditioning, prior to exposure to severe desiccation. Although tardigrades are thought to prepare for transition to anhydrobiosis during preconditioning, the molecular mechanisms governing such processes remain unknown. In this study, we used chemical genetic approaches to elucidate the regulatory mechanisms of anhydrobiosis in the anhydrobiotic tardigrade, Hypsibius dujardini. We first demonstrated that inhibition of transcription or translation drastically impaired anhydrobiotic survival, suggesting that de novo gene expression is required for successful transition to anhydrobiosis in this tardigrade. We then screened 81 chemicals and identified 5 chemicals that significantly impaired anhydrobiotic survival after severe desiccation, in contrast to little or no effect on survival after high humidity exposure only. In particular, cantharidic acid, a selective inhibitor of protein phosphatase (PP) 1 and PP2A, exhibited the most profound inhibitory effects. Another PP1/PP2A inhibitor, okadaic acid, also significantly and specifically impaired anhydrobiotic survival, suggesting that PP1/PP2A activity plays an important role for anhydrobiosis in this species. This is, to our knowledge, the first report of the required activities of signaling molecules for desiccation tolerance in tardigrades. The identified inhibitory chemicals could provide novel clues to elucidate the regulatory mechanisms underlying anhydrobiosis in tardigrades. PMID:26690982

  15. Active smart material control system for buffet alleviation

    NASA Astrophysics Data System (ADS)

    Sheta, Essam F.; Moses, Robert W.; Huttsell, Lawrence J.

    2006-05-01

    Vertical tail buffeting is a serious multidisciplinary problem that limits the performance and maneuverability of twin-tail fighter aircraft. The buffet problem occurs at high angles of attack when the vortical flow breaks down ahead of the vertical tails resulting in unsteady and unbalanced loads on the tails leading to their premature fatigue failure. An active smart material control system, using distributed piezoelectric (PZT) actuators, is developed for buffet alleviation and is presented. The surfaces of the vertical tail are equipped with PZT actuators to control the buffet responses in the first bending and torsion modes. The electrodynamics of the PZT actuators are modeled using a finite-element model. A single-input/single-output controller is designed to drive the active PZT actuators. High-fidelity analysis modules for the fluid dynamics, structural dynamics, electrodynamics of the PZT actuators, control law, fluid-structure interfacing, and grid motion are integrated into a multidisciplinary computing environment that controls the temporal synchronization of the analysis modules. The results of this study indicate that the actively controlled PZT actuators are an effective tool for buffet alleviation over wide range of angels of attack. Peak values of power spectral density of tail-tip acceleration are reduced by as much as 22% in the first bending mode and by as much as 82% in the first torsion mode. The root mean square values of tail-tip acceleration are reduced by as much as 12%.

  16. Development of active and sensitive material systems based on composites

    NASA Astrophysics Data System (ADS)

    Asanuma, Hiroshi

    2002-07-01

    This paper describes new concepts proposed by the author to realize active and sensitive structural material systems. Two examples of multifunctional composites were fabricated and evaluated in this study as follows: (1) An active laminate of aluminum plate (works as muscle), epoxy film (as insulator), unidirectional CFRP prepreg (as bone and blood vessel) and copper foil electrode (to apply voltage on CFRP) was made with an embedded optical fiber multiply fractured in the CFRP layer (works as nerve), of which curvature change could be effectively monitored with the fractured optical fiber. (2) A stainless steel fiber/aluminum active composite with embedded Ti oxide/Ti composite fiber was fabricated. The Ti oxide/Ti fiber could work as a sensor for temperature by removing a part of the oxide before embedment to make a metallic contact between the embedded titanium fiber and aluminum matrix to be able to generate thermal electromotive force, and also could work as a sensor for strain and as a heater for actuation. In the both cases, the outputs from their embedded sensors can be used to control their actuations.

  17. Addressing Different Active Neutron Interrogation Signatures from Fissionable Material

    SciTech Connect

    D. L. Chichester; E. H. Seabury

    2009-10-01

    In a continuing effort to examine portable methods for implementing active neutron interrogation for detecting shielded fissionable material research is underway to investigate the utility of analyzing multiple time-correlated signatures. Time correlation refers here to the existence of unique characteristics of the fission interrogation signature related to the start and end of an irradiation, as well as signatures present in between individual pulses of an irradiating source. Traditional measurement approaches in this area have typically worked to detect die-away neutrons after the end of each pulse, neutrons in between pulses related to the decay of neutron emitting fission products, or neutrons or gamma rays related to the decay of neutron emitting fission products after the end of an irradiation exposure. In this paper we discus the potential weaknesses of assessing only one signature versus multiple signatures and make the assertion that multiple complimentary and orthogonal measurements should be used to bolster the performance of active interrogation systems, helping to minimize susceptibility to the weaknesses of individual signatures on their own. Recognizing that the problem of detection is a problem of low count rates, we are exploring methods to integrate commonly used signatures with rarely used signatures to improve detection capabilities for these measurements. In this paper we will discuss initial activity in this area with this approach together with observations of some of the strengths and weaknesses of using these different signatures.

  18. Short communication: Effect of active food packaging materials on fluid milk quality and shelf life.

    PubMed

    Wong, Dana E; Goddard, Julie M

    2014-01-01

    Active packaging, in which active agents are embedded into or on the surface of food packaging materials, can enhance the nutritive value, economics, and stability of food, as well as enable in-package processing. In one embodiment of active food packaging, lactase was covalently immobilized onto packaging films for in-package lactose hydrolysis. In prior work, lactase was covalently bound to low-density polyethylene using polyethyleneimine and glutaraldehyde cross-linkers to form the packaging film. Because of the potential contaminants of proteases, lipases, and spoilage organisms in typical enzyme preparations, the goal of the current work was to determine the effect of immobilized-lactase active packaging technology on unanticipated side effects, such as shortened shelf-life and reduced product quality. Results suggested no evidence of lipase or protease activity on the active packaging films, indicating that such active packaging films could enable in-package lactose hydrolysis without adversely affecting product quality in terms of dairy protein or lipid stability. Storage stability studies indicated that lactase did not migrate from the film over a 49-d period, and that dry storage resulted in 13.41% retained activity, whereas wet storage conditions enabled retention of 62.52% activity. Results of a standard plate count indicated that the film modification reagents introduced minor microbial contamination; however, the microbial population remained under the 20,000 cfu/mL limit through the manufacturer's suggested 14-d storage period for all film samples. This suggests that commercially produced immobilized lactase active packaging should use purified cross-linkers and enzymes. Characterization of unanticipated effects of active packaging on food quality reported here is important in demonstrating the commercial potential of such technologies. PMID:24239074

  19. Short communication: Effect of active food packaging materials on fluid milk quality and shelf life.

    PubMed

    Wong, Dana E; Goddard, Julie M

    2014-01-01

    Active packaging, in which active agents are embedded into or on the surface of food packaging materials, can enhance the nutritive value, economics, and stability of food, as well as enable in-package processing. In one embodiment of active food packaging, lactase was covalently immobilized onto packaging films for in-package lactose hydrolysis. In prior work, lactase was covalently bound to low-density polyethylene using polyethyleneimine and glutaraldehyde cross-linkers to form the packaging film. Because of the potential contaminants of proteases, lipases, and spoilage organisms in typical enzyme preparations, the goal of the current work was to determine the effect of immobilized-lactase active packaging technology on unanticipated side effects, such as shortened shelf-life and reduced product quality. Results suggested no evidence of lipase or protease activity on the active packaging films, indicating that such active packaging films could enable in-package lactose hydrolysis without adversely affecting product quality in terms of dairy protein or lipid stability. Storage stability studies indicated that lactase did not migrate from the film over a 49-d period, and that dry storage resulted in 13.41% retained activity, whereas wet storage conditions enabled retention of 62.52% activity. Results of a standard plate count indicated that the film modification reagents introduced minor microbial contamination; however, the microbial population remained under the 20,000 cfu/mL limit through the manufacturer's suggested 14-d storage period for all film samples. This suggests that commercially produced immobilized lactase active packaging should use purified cross-linkers and enzymes. Characterization of unanticipated effects of active packaging on food quality reported here is important in demonstrating the commercial potential of such technologies.

  20. Immunolocalization of Anti-Hsf1 to the Acetabular Glands of Infectious Schistosomes Suggests a Non-Transcriptional Function for This Transcriptional Activator

    PubMed Central

    Knudsen, Giselle M.; Jolly, Emmitt R.

    2014-01-01

    Schistosomiasis is a chronically debilitating disease caused by parasitic worms of the genus Schistosoma, and it is a global problem affecting over 240 million people. Little is known about the regulatory proteins and mechanisms that control schistosome host invasion, gene expression, and development. Schistosome larvae, cercariae, are transiently free-swimming organisms and infectious to man. Cercariae penetrate human host skin directly using proteases that degrade skin connective tissue. These proteases are secreted from anucleate acetabular glands that contain many proteins, including heat shock proteins. Heat shock transcription factors are strongly conserved activators that play crucial roles in the maintenance of cell homeostasis by transcriptionally regulating heat shock protein expression. In this study, we clone and characterize the schistosome Heat shock factor 1 gene (SmHSF1). We verify its ability to activate transcription using a modified yeast one-hybrid system, and we show that it can bind to the heat shock binding element (HSE) consensus DNA sequence. Our quantitative RT-PCR analysis shows that SmHSF1 is expressed throughout several life-cycle stages from sporocyst to adult worm. Interestingly, using immunohistochemistry, a polyclonal antibody raised against an Hsf1-peptide demonstrates a novel localization for this conserved, stress-modulating activator. Our analysis suggests that schistosome Heat shock factor 1 may be localized to the acetabular glands of infective cercariae. PMID:25078989

  1. Psychosocial predictors of decay in healthy eating and physical activity improvements in obese women regaining lost weight: translation of behavioral theory into treatment suggestions.

    PubMed

    Annesi, James J

    2016-06-01

    Regain of lost weight is a universal problem for behavioral treatments. An increased understanding of theory-based psychosocial predictors of decay in behavioral correlates of weight loss might improve treatments. Data were derived from a previous weight loss investigation of 110 women with obesity. A subsample from the experimental treatment who lost ≥3 % body weight and regained at least one third of that over 24 months (N = 36) was assessed. During months 6 through 24, there were unfavorable changes in behavioral (fruit/vegetable and sweet intake; physical activity) and psychosocial variables. Mood change predicted change in fruit/vegetable and sweet intake, with emotional eating change mediating the latter relationship. Change in self-regulation predicted changes in sweet and fruit/vegetable intake and physical activity, with self-efficacy mediating the self-regulation-fruit/vegetable intake and self-regulation-physical activity relationships. Findings suggest that after treatment-induced weight loss, addressing indicated theory-based psychosocial variables might mitigate decay in behavioral predictors of healthier weight. PMID:27052217

  2. Clonality Analysis of Immunoglobulin Gene Rearrangement by Next-Generation Sequencing in Endemic Burkitt Lymphoma Suggests Antigen Drive Activation of BCR as Opposed to Sporadic Burkitt Lymphoma

    PubMed Central

    Amato, Teresa; Abate, Francesco; Piccaluga, Pierpaolo; Iacono, Michele; Fallerini, Chiara; Renieri, Alessandra; De Falco, Giulia; Ambrosio, Maria Raffaella; Mourmouras, Vaselious; Ogwang, Martin; Calbi, Valeria; Rabadan, Roul; Hummel, Michael; Pileri, Stefano; Bellan, Cristiana

    2016-01-01

    Objectives: Recent studies using next-generation sequencing (NGS) analysis disclosed the importance of the intrinsic activation of the B-cell receptor (BCR) pathway in the pathogenesis of sporadic Burkitt lymphoma (sBL) due to mutations of TCF3/ID3 genes. Since no definitive data are available on the genetic landscape of endemic Burkitt (eBL), we first assessed the mutation frequency of TCF3/ID3 in eBL compared with sBL and subsequently the somatic hypermutation status of the BCR to answer whether an extrinsic activation of BCR signaling could also be demonstrated in Burkitt lymphoma. Methods: We assessed the mutations of TCF3/ID3 by RNAseq and the BCR status by NGS analysis of the immunoglobulin genes (IGs). Results: We detected mutations of TCF3/ID3 in about 30% of the eBL cases. This rate is significantly lower than that detected in sBL (64%). The NGS analysis of IGs revealed intraclonal diversity, suggesting an active targeted somatic hypermutation process in eBL compared with sBL. Conclusions: These findings support the view that the antigenic pressure plays a key role in the pathogenetic pathways of eBL, which may be partially distinct from those driving sBL development. PMID:26712879

  3. Canada's Physical Activity Guide: examining print-based material for motivating physical activity in the workplace.

    PubMed

    Plotnikoff, Ronald C; Todosijczuk, Ivan; Johnson, Steven T; Karunamuni, Nandini

    2012-01-01

    The authors conducted a secondary analysis on 202 adults from the Physical Activity Workplace Study. The aim of this analysis was to examine demographic characteristics associated with reading Canada's Physical Activity Guide (CPAG), being motivated by the guide, and whether participants in the Physical Activity Workplace Study who read the CPAG increased their physical activity levels over 1 year. Results revealed that less than 50% of participants read the full version of CPAG, and less than 10% were motivated by it. The CPAG also appears to be more appealing to and effective for women than for men. Although the CPAG had some influence in increasing mild physical activity levels in a workplace sample, there was also a decrease in physical activity levels among some members of the group. Overall, the effectiveness of CPAG was not substantial, and the findings of this analysis could help guide future targeted intervention materials and programs.

  4. Surface modification of active material structures in battery electrodes

    DOEpatents

    Erickson, Michael; Tikhonov, Konstantin

    2016-02-02

    Provided herein are methods of processing electrode active material structures for use in electrochemical cells or, more specifically, methods of forming surface layers on these structures. The structures are combined with a liquid to form a mixture. The mixture includes a surface reagent that chemically reacts and forms a surface layer covalently bound to the structures. The surface reagent may be a part of the initial liquid or added to the mixture after the liquid is combined with the structures. In some embodiments, the mixture may be processed to form a powder containing the structures with the surface layer thereon. Alternatively, the mixture may be deposited onto a current collecting substrate and dried to form an electrode layer. Furthermore, the liquid may be an electrolyte containing the surface reagent and a salt. The liquid soaks the previously arranged electrodes in order to contact the structures with the surface reagent.

  5. Overview of Indian activities on fusion reactor materials

    NASA Astrophysics Data System (ADS)

    Banerjee, Srikumar

    2014-12-01

    This paper on overview of Indian activities on fusion reactor materials describes in brief the efforts India has made to develop materials for the first wall of a tokamak, its blanket and superconducting magnet coils. Through a systematic and scientific approach, India has developed and commercially produced reduced activation ferritic/martensitic (RAFM) steel that is comparable to Eurofer 97. Powder of low activation ferritic/martensitic oxide dispersion strengthened steel with characteristics desired for its application in the first wall of a tokamak has been produced on the laboratory scale. V-4Cr-4Ti alloy was also prepared in the laboratory, and kinetics of hydrogen absorption in this was investigated. Cu-1 wt%Cr-0.1 wt%Zr - an alloy meant for use as heat transfer elements for hypervapotrons and heat sink for the first wall - was developed and characterized in detail for its aging behavior. The role of addition of a small quantity of Zr in its improved fatigue performance was delineated, and its diffusion bonding with both W and stainless steel was achieved using Ni as an interlayer. The alloy was produced in large quantities and used for manufacturing both the heat transfer elements and components for the International Thermonuclear Experimental Reactor (ITER). India has proposed to install and test a lead-lithium cooled ceramic breeder test blanket module (LLCB-TBM) at ITER. To meet this objective, efforts have been made to produce and characterize Li2TiO3 pebbles, and also improve the thermal conductivity of packed beds of these pebbles. Liquid metal loops have been set up and corrosion behavior of RAFM steel in flowing Pb-Li eutectic has been studied in the presence as well as absence of magnetic fields. To prevent permeation of tritium and reduce the magneto-hydro-dynamic drag, processes have been developed for coating alumina on RAFM steel. Apart from these activities, different approaches being attempted to make the U-shaped first wall of the TBM box

  6. The proteolytic profile of human cancer procoagulant suggests that it promotes cancer metastasis at the level of activation rather than degradation.

    PubMed

    Kee, Nalise Low Ah; Krause, Jason; Blatch, Gregory L; Muramoto, Koji; Sakka, Kazuo; Sakka, Makiko; Naudé, Ryno J; Wagner, Leona; Wolf, Raik; Rahfeld, Jens-Ulrich; Demuth, Hans-Ulrich; Mielicki, Wojciech P; Frost, Carminita L

    2015-10-01

    Proteases are essential for tumour progression and many are over-expressed during this time. The main focus of research was the role of these proteases in degradation of the basement membrane and extracellular matrix (ECM), thereby enabling metastasis to occur. Cancer procoagulant (CP), a protease present in malignant tumours, but not normal tissue, is a known activator of coagulation factor X (FX). The present study investigated the function of CP in cancer progression by focussing on its enzymatic specificity. FX cleavage was confirmed using SDS-PAGE and MALDI-TOF MS and compared to the proteolytic action of CP on ECM proteins, including collagen type IV, laminin and fibronectin. Contrary to previous reports, CP cleaved FX at the conventional activation site (between Arg-52 and Ile-53). Additionally, degradation of FX by CP occurred at a much slower rate than degradation by conventional activators. Complete degradation of the heavy chain of FX was only visible after 24 h, while degradation by RVV was complete after 30 min, supporting postulations that the procoagulant function of CP may be of secondary importance to its role in cancer progression. Of the ECM proteins tested, only fibronectin was cleaved. The substrate specificity of CP was further investigated by screening synthetic peptide substrates using a novel direct CP assay. The results indicate that CP is not essential for either cancer-associated blood coagulation or the degradation of ECM proteins. Rather, they suggest that this protease may be required for the proteolytic activation of membrane receptors.

  7. 77 FR 38395 - Agency Information Collection Activities (Advertising, Sales, and Enrollment Materials, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... AFFAIRS Agency Information Collection Activities (Advertising, Sales, and Enrollment Materials, and... ``OMB Control No. 2900-0682.'' SUPPLEMENTARY INFORMATION: Title: Advertising, Sales, and Enrollment... advertising, sales materials, enrollment materials, or candidate handbooks that educational institutions...

  8. A Comparison of Vanadate to a 2'-5' Linkage at the Active Site of a Small Ribozyme Suggests a Role for Water in Transition-State Stabilization

    SciTech Connect

    Torelli, A.T.; Krucinska, J.; Wedekind, J.E.

    2009-06-04

    The potential for water to participate in RNA catalyzed reactions has been the topic of several recent studies. Here, we report crystals of a minimal, hinged hairpin ribozyme in complex with the transition-state analog vanadate at 2.05 A resolution. Waters are present in the active site and are discussed in light of existing views of catalytic strategies employed by the hairpin ribozyme. A second structure harboring a 2',5'-phosphodiester linkage at the site of cleavage was also solved at 2.35 A resolution and corroborates the assignment of active site waters in the structure containing vanadate. A comparison of the two structures reveals that the 2',5' structure adopts a conformation that resembles the reaction intermediate in terms of (1) the positioning of its nonbridging oxygens and (2) the covalent attachment of the 2'-O nucleophile with the scissile G+1 phosphorus. The 2',5'-linked structure was then overlaid with scissile bonds of other small ribozymes including the glmS metabolite-sensing riboswitch and the hammerhead ribozyme, and suggests the potential of the 2',5' linkage to elicit a reaction-intermediate conformation without the need to form metalloenzyme complexes. The hairpin ribozyme structures presented here also suggest how water molecules bound at each of the nonbridging oxygens of G+1 may electrostatically stabilize the transition state in a manner that supplements nucleobase functional groups. Such coordination has not been reported for small ribozymes, but is consistent with the structures of protein enzymes. Overall, this work establishes significant parallels between the RNA and protein enzyme worlds.

  9. Activities for Teaching about Hazardous Materials in the Home.

    ERIC Educational Resources Information Center

    Howe, Robert W.; And Others

    Materials containing hazardous substances present serious problems to human health and to the health of the environment. There are many potential problems related to the site of a house or apartment, the construction materials used in the house or the apartment, products and materials used in and around the home, and disposal of materials.…

  10. Active and passive biomonitoring suggest metabolic adaptation in blue mussels (Mytilus spp.) chronically exposed to a moderate contamination in Brest harbor (France).

    PubMed

    Lacroix, Camille; Richard, Gaëlle; Seguineau, Catherine; Guyomarch, Julien; Moraga, Dario; Auffret, Michel

    2015-05-01

    Brest harbor (Bay of Brest, Brittany, France) has a severe past of anthropogenic chemical contamination, but inputs tended to decrease, indicating a reassessment of its ecotoxicological status should be carried out. Here, native and caged mussels (Mytilus spp.) were used in combination to evaluate biological effects of chronic chemical contamination in Brest harbor. Polycyclic aromatic hydrocarbon (PAH) contamination was measured in mussel tissues as a proxy of harbor and urban pollution. Biochemical biomarkers of xenobiotic biotransformation, antioxidant defenses, generation of reducing equivalents, energy metabolism and oxidative damage were studied in both gills and digestive glands of native and caged mussels. In particular, activities of glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), NADP-dependent isocitrate dehydrogenase (IDP), pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK) were measured and lipid peroxidation was assessed by malondialdehyde (MDA) quantification. In addition, a condition index was calculated to assess the overall health of the mussels. Moderate PAH contamination was detected in digestive glands of both native and caged individuals from the exposed site. Modulations of biomarkers were detected in digestive glands of native harbor mussels indicating the presence of a chemical pressure. In particular, results suggested increased biotransformation (GST), antioxidant defenses (CAT), NADPH generation (IDP) and gluconeogenesis (PEPCK), which could represent a coordinated response against chemically-induced cellular stress. Lipid peroxidation assessment and condition index indicated an absence of acute stress in the same mussels suggesting metabolic changes could, at least partially, offset the negative effects of contamination. In caged mussels, only GR was found modulated compared to non-exposed mussels but significant differences in

  11. Activation and waste management considerations of fusion materials

    NASA Astrophysics Data System (ADS)

    Cheng, E. T.; Saji, G.

    1994-09-01

    Inconel-625 (Ni625), SS316, Ti-6Al-4V (Ti64), ferritic steel (FS), reduced activity ferritic steel (RAFS), manganese steel (Mn-steel), and V5Cr5Ti (V55), were examined for a near-term experimental D-T fueled fusion power reactor with respect to waste management. Activation calculations for these materials were performed assuming one year continuous operation at 1 MW/m 2 wall loading. The results show that the blanket components made of V55, Ti64, Mn-steel, and FS will be allowed for transfer to an on-site dry storage facility after 10 years of cooling after discharge. To transport the discharged blanket components to a permanent disposal site, the cooling time needed can be within 10 years for Ti64 and V55, provided that the impurities (mainly Ni, Nb and Mo) be controlled to an acceptable level. The RAFS and Mn-steel will need about 30 y cooling time because of its Fe and Mn contents. Ni625, 316SS, and FS, however, will require more than 50000 y cooling time because of their Nb and Mo contents. The RAFS, Mn-steel, Ti64 and V55 can be shallow-land wastes if the impurity level for Nb and Mo is dropped below 10 ppm.

  12. Non-photochemical quenching and xanthophyll cycle activities in six green algal species suggest mechanistic differences in the process of excess energy dissipation.

    PubMed

    Quaas, Theresa; Berteotti, Silvia; Ballottari, Matteo; Flieger, Kerstin; Bassi, Roberto; Wilhelm, Christian; Goss, Reimund

    2015-01-01

    In the present study the non-photochemical quenching (NPQ) of four biofilm-forming and two planktonic green algae was investigated by fluorescence measurements, determinations of the light-driven proton gradient and determination of the violaxanthin cycle activity by pigment analysis. It was observed that, despite the common need for efficient photoprotection, the structural basis of NPQ was heterogeneous in the different species. Three species, namely Chlorella saccharophila, Chlorella vulgaris and Bracteacoccus minor, exhibited a zeaxanthin-dependent NPQ, while in the three other species, Tetracystis aeria, Pedinomonas minor and Chlamydomonas reinhardtii violaxanthin de-epoxidation was absent or unrelated to the establishment of NPQ. Acclimation of the algae to high light conditions induced an increase of the NPQ activity, suggesting that a significant part of the overall NPQ was rather inducible than constitutively present in the green algae. Comparing the differences in the NPQ mechanisms with the phylogenetic position of the six algal species led to the conclusion that the NPQ heterogeneity observed in the present study was not related to the phylogeny of the algae but to the environmental selection pressure. Finally, the difference in the NPQ mechanisms in the different species is discussed within the frame of the current NPQ models.

  13. ReflectoActive{trademark} Seals for Materials Control and Accountability

    SciTech Connect

    Richardson, G.D.; Younkin, J.R.; Bell, Z.W.

    2002-01-01

    The ReflectoActive{trademark} Seals system, a continuously monitored fiber optic, active seal technology, provides real-time tamper indication for large arrays of storage containers. The system includes a PC running the RFAS software, an Immediate Detection Unit (IDU), an Optical Time Domain Reflectometer (OTDR), links of fiber optic cable, and the methods and devices used to attach the fiber optic cable to the containers. When a breach on any of the attached fiber optic cable loops occurs, the IDU immediately signals the connected computer to control the operations of an OTDR to seek the breach location. The ReflectoActive{trademark} Seals System can be adapted for various types of container closure designs and implemented in almost any container configuration. This automatic protection of valued assets can significantly decrease the time and money required for surveillance. The RFAS software is the multi-threaded, client-server application that monitors and controls the components of the system. The software administers the security measures such as a two-person rule as well as continuous event logging. Additionally the software's architecture provides a secure method by which local or remote clients monitor the system and perform administrative tasks. These features provide the user with a robust system to meet today's material control and accountability needs. A brief overview of the hardware, and different hardware configurations will be given. The architecture of the system software, and its benefits will then be discussed. Finally, the features to be implemented in future versions of the system will be presented.

  14. Evaluation of cytotoxicity, antimicrobial activity and physicochemical properties of a calcium aluminate-based endodontic material

    PubMed Central

    SILVA, Emmanuel João Nogueira Leal; HERRERA, Daniel Rodrigo; ROSA, Tiago Pereira; DUQUE, Thais Mageste; JACINTO, Rogério Castilho; GOMES, Brenda Paula Figueiredo de Almeida; ZAIA, Alexandre Augusto

    2014-01-01

    A calcium aluminate-based endodontic material, EndoBinder, has been developed in order to reduce MTA negative characteristics, preserving its biological properties and clinical applications. Objectives The aim of this study was to evaluate the cytotoxicity, antimicrobial activity, pH, solubility and water sorption of EndoBinder and to compare them with those of white MTA (WMTA). Material and Methods Cytotoxicity was assessed through a multiparametric analysis employing 3T3 cells. Antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus. (ATCC 25923) and Candida albicans (ATCC 10556) was determined by the agar diffusion method. pH was measured at periods of 3, 24, 72 and 168 hours. Solubility and water sorption evaluation were performed following ISO requirements. Data were statistically analyzed by ANOVA and Tukey`s test with a significance level of 5%. Results EndoBinder and WMTA were non-cytotoxic in all tested periods and with the different cell viability parameters. There was no statistical differences between both materials (P>.05). All tested materials were inhibitory by direct contact against all microbial strains tested. EndoBinder and WMTA presented alkaline pH in all tested times with higher values of pH for WMTA (P<.05). Both materials showed values complying with the solubility minimum requirements. However, EndoBinder showed lower solubility than WMTA (P<.05). No statistical differences were observed regarding water sorption (P>.05). Conclusion Under these experimental conditions, we concluded that the calcium aluminate-based endodontic material EndoBinder demonstrated suitable biological and physicochemical properties, so it can be suggested as a material of choice in root resorption, perforations and root-end filling. PMID:24626250

  15. Open to Suggestion.

    ERIC Educational Resources Information Center

    Journal of Reading, 1987

    1987-01-01

    Offers (1) suggestions for improving college students' study skills; (2) a system for keeping track of parent, teacher, and community contacts; (3) suggestions for motivating students using tic tac toe; (4) suggestions for using etymology to improve word retention; (5) a word search grid; and (6) suggestions for using postcards in remedial reading…

  16. Single-agent lenalidomide in relapsed/refractory mantle cell lymphoma: results from a UK phase II study suggest activity and possible gender differences.

    PubMed

    Eve, Heather E; Carey, Sean; Richardson, Sarah J; Heise, Carla C; Mamidipudi, Vidya; Shi, Tao; Radford, John A; Auer, Rebecca L; Bullard, Sheila H; Rule, Simon A J

    2012-10-01

    We present data from a phase II study investigating a novel treatment strategy for relapsed/refractory mantle cell lymphoma (MCL). Twenty-six patients received lenalidomide 25 mg/d (days 1-21 of a 28-d cycle) for up to 6 cycles followed by low-dose maintenance lenalidomide (15 mg) in responding patients. Eight patients achieved complete or partial response to give an overall response rate of 31% with median response duration of 22·2 months [95% confidence interval (CI) 0·0-53·6] and median progression-free survival (PFS) of 3·9 months (95% CI 0·0-11·1). An additional six patients (23%) achieved stable disease. Eleven patients received maintenance with median PFS of 14·6 months (95% CI 7·3-21·9). Correlative studies showed that peripheral T and Natural Killer (NK) cells increased in responding patients by 40-60% over the first 6 cycles with an initial dip in NK cells suggestive of tumour infiltration. Peripheral regulatory T cells were increased in MCL patients (P = 0·001) and expanded further following lenalidomide. Sequential plasma analysis showed increased IL12 p40 and IL7 alongside decreased MMP9, IL10, and adiponectin. Finally, a significant correlation (P = 0·02) between gender and response suggested that female MCL patients were more sensitive to lenalidomide than males. In summary, we confirm the activity, safety and immunomodulatory properties of lenalidomide in MCL and highlight its potential as a low-dose maintenance agent.

  17. Examining porous bio-active glass as a potential osteo-odonto-keratoprosthetic skirt material.

    PubMed

    Huhtinen, Reeta; Sandeman, Susan; Rose, Susanna; Fok, Elsie; Howell, Carol; Fröberg, Linda; Moritz, Niko; Hupa, Leena; Lloyd, Andrew

    2013-05-01

    Bio-active glass has been developed for use as a bone substitute with strong osteo-inductive capacity and the ability to form strong bonds with soft and hard tissue. The ability of this material to enhance tissue in-growth suggests its potential use as a substitute for the dental laminate of an osteo-odonto-keratoprosthesis. A preliminary in vitro investigation of porous bio-active glass as an OOKP skirt material was carried out. Porous glass structures were manufactured from bio-active glasses 1-98 and 28-04 containing varying oxide formulation (1-98, 28-04) and particle size range (250-315 μm for 1-98 and 28-04a, 315-500 μm for 28-04b). Dissolution of the porous glass structure and its effect on pH was measured. Structural 2D and 3D analysis of porous structures were performed. Cell culture experiments were carried out to study keratocyte adhesion and the inflammatory response induced by the porous glass materials. The dissolution results suggested that the porous structure made out of 1-98 dissolves faster than the structures made from glass 28-04. pH experiments showed that the dissolution of the porous glass increased the pH of the surrounding solution. The cell culture results showed that keratocytes adhered onto the surface of each of the porous glass structures, but cell adhesion and spreading was greatest for the 98a bio-glass. Cytokine production by all porous glass samples was similar to that of the negative control indicating that the glasses do not induce a cytokine driven inflammatory response. Cell culture results support the potential use of synthetic porous bio-glass as an OOKP skirt material in terms of limited inflammatory potential and capacity to induce and support tissue ingrowth.

  18. (Bio)hybrid materials based on optically active particles

    NASA Astrophysics Data System (ADS)

    Reitzig, Manuela; Härtling, Thomas; Opitz, Jörg

    2014-03-01

    In this contribution we provide an overview of current investigations on optically active particles (nanodiamonds, upconversion phospors) for biohybrid and sensing applications. Due to their outstanding properties nanodiamonds gain attention in various application elds such as microelectronics, optical monitoring, medicine, and biotechnology. Beyond the typical diamond properties such as high thermal conductivity and extreme hardness, the carbon surface and its various functional groups enable diverse chemical and biological surface functionalization. At Fraunhofer IKTS-MD we develop a customization of material surfaces via integration of chemically modi ed nanodiamonds at variable surfaces, e.g bone implants and pipelines. For the rst purpose, nanodiamonds are covalently modi ed at their surface with amino or phosphate functionalities that are known to increase adhesion to bone or titanium alloys. The second type of surface is approached via mechanical implementation into coatings. Besides nanodiamonds, we also investigate the properties of upconversion phosphors. In our contribution we show how upconversion phosphors are used to verify sterilization processes via a change of optical properties due to sterilizing electron beam exposure.

  19. Structural materials for fusion power reactors—the RF R&D activities

    NASA Astrophysics Data System (ADS)

    Chernov, V. M.; Leonteva-Smirnova, M. V.; Potapenko, M. M.; Budylkin, N. I.; Devyatko, Yu. N.; Ioltoukhovskiy, A. G.; Mironova, E. G.; Shikov, A. K.; Sivak, A. B.; Yermolaev, G. N.; Kalashnikov, A. N.; Kuteev, B. V.; Blokhin, A. I.; Loginov, N. I.; Romanov, V. A.; Belyakov, V. A.; Kirillov, I. R.; Bulanova, T. M.; Golovanov, V. N.; Shamardin, V. K.; Strebkov, Yu. S.; Tyumentsev, A. N.; Kardashev, B. K.; Mishin, O. V.; Vasiliev, B. A.

    2007-08-01

    Recent progress in the RF low activation structural materials R&D road map towards DEMO via the FBR tests (BOR-60, BN-600, BN-800) and the TBM tests in ITER is overviewed. The properties of the RAFMS RUSFER-EK-181 (Fe-12Cr-2W-Ta-V-B-C) and the V-4Ti-4Cr alloys are presented. The next important steps include further studies on the influence of high dose and high-temperature irradiation on the properties of base structural materials and joints. Activation, transmutation and radiation damage of the materials in BN-600 and DEMO-RF (Kurchatov Institute project) neutron spectra are calculated. The results of the application of the internal friction (ultrasonic) non-destructive method to research the DBTT are in good agreement with the results of the destructive impact method. The important influence of boron on the heat resistance of materials and the He concentration level under irradiation are calculated. The new special regimes of the heat treatments of the alloys are suggested to widen the temperature windows of the applications. The results of the BOR-60 examinations of RUSFER-EK-181 (irradiation temperature 320-340 °C and doses up to 15 dpa) are presented. The BN-600 projects for the high dose and high-temperature irradiation tests of manufactured alloys are presented.

  20. Genome wide survey and molecular modeling of hypothetical proteins containing 2Fe-2S and FMN binding domains suggests Rieske Dioxygenase Activity highlighting their potential roles in bioremediation.

    PubMed

    Sathyanarayanan, Nitish; Nagendra, Holenarsipur Gundurao

    2014-01-01

    'Conserved hypothetical' proteins pose a challenge not just for functional genomics, but also to biology in general. As long as there are hundreds of conserved proteins with unknown function in model organisms such as Escherichia coli, Bacillus subtilis or Saccharomyces cerevisiae, any discussion towards a 'complete' understanding of these biological systems will remain a wishful thinking. Insilico approaches exhibit great promise towards attempts that enable appreciating the plausible roles of these hypothetical proteins. Among the majority of genomic proteins, two-thirds in unicellular organisms and more than 80% in metazoa, are multi-domain proteins, created as a result of gene duplication events. Aromatic ring-hydroxylating dioxygenases, also called Rieske dioxygenases (RDOs), are class of multi-domain proteins that catalyze the initial step in microbial aerobic degradation of many aromatic compounds. Investigations here address the computational characterization of hypothetical proteins containing Ferredoxin and Flavodoxin signatures. Consensus sequence of each class of oxidoreductase was obtained by a phylogenetic analysis, involving clustering methods based on evolutionary relationship. A synthetic sequence was developed by combining the consensus, which was used as the basis to search for their homologs via BLAST. The exercise yielded 129 multidomain hypothetical proteins containing both 2Fe-2S (Ferredoxin) and FNR (Flavodoxin) domains. In the current study, 17 proteins with N-terminus FNR domain and C-terminus 2Fe-2S domain are characterized, through homology modelling and docking exercises which suggest dioxygenase activity indicate their plausible roles in degradation of aromatic moieties. PMID:24616557

  1. Analysis of multi-domain hypothetical proteins containing iron-sulphur clusters and fad ligands reveal rieske dioxygenase activity suggesting their plausible roles in bioremediation

    PubMed Central

    Sathyanarayanan, Nitish; Nagendra, Holenarasipur Gundurao

    2012-01-01

    ‘Conserved hypothetical’ proteins pose a challenge not just for functional genomics, but also to biology in general. As long as there are hundreds of conserved proteins with unknown function in model organisms such as Escherichia coli, Bacillus subtilis or Saccharomyces cerevisiae, any discussion towards a ‘complete’ understanding of these biological systems will remain a wishful thinking. Insilico approaches exhibit great promise towards attempts that enable appreciating the plausible roles of these hypothetical proteins. Among the majority of genomic proteins, two-thirds in unicellular organisms and more than 80% in metazoa, are multi-domain proteins, created as a result of gene duplication events. Aromatic ring-hydroxylating dioxygenases, also called Rieske dioxygenases (RDOs), are class of multi-domain proteins that catalyze the initial step in microbial aerobic degradation of many aromatic compounds. Investigations here address the computational characterization of hypothetical proteins containing Ferredoxin and Flavodoxin signatures. Consensus sequence of each class of oxidoreductase was obtained by a phylogenetic analysis, involving clustering methods based on evolutionary relationship. A synthetic sequence was developed by combining the consensus, which was used as the basis to search for their homologs via BLAST. The exercise yielded 129 multidomain hypothetical proteins containing both 2Fe-2S (Ferredoxin) and FNR (Flavodoxin) domains. In the current study, 40 proteins with N-terminus 2Fe-2S domain and C-terminus FNR domain are characterized, through homology modelling and docking exercises which suggest dioxygenase activity indicating their plausible roles in degradation of aromatic moieties. PMID:23275712

  2. The Life of Suggestions

    ERIC Educational Resources Information Center

    Pearce, Cathie

    2010-01-01

    Using the notion of a suggestion, or rather charting the life of suggestions, this article considers the happenings of chance and embodiment as the "problems that got away." The life of suggestions helps us to ask how connectivities are made, how desire functions, and how "immanence" rather than "transcendence" can open up the politics and ethics…

  3. Recurring Swarms of Deep Long Period Earthquakes in the Denali Volcanic Gap Suggest a Continuation of Volcanic Processes in the Absence of Active Volcanism

    NASA Astrophysics Data System (ADS)

    Holtkamp, S. G.; Ruppert, N. A.; Silwal, V.; Christensen, D. H.; Nye, C. J.

    2014-12-01

    Seismicity in the northern segment of the Denali Volcanic Gap clusters bimodally with depth, with dense clusters of earthquakes occurring in the subducting slab at >100 km depth beneath Denali, and within the crust north of the Denali fault at <20 km depth. On January 22, 2014, the Alaska Earthquake Center recorded a Deep Long Period earthquake (DLP), magnitude 1.7, at 40 km depth north of the Denali Fault. The epicenter for this event was <5 km of broadband station TRF, so the depth is well constrained. The DLP event is almost devoid of energy above 5 Hz. Receiver functions for stations TRF and SBL, both <10 km of the epicenter, show Moho depths of 36-40 km.We used waveforms of this DLP as a template event for network matched filtering, which identifies similar signals in continuous time series. We processed this template event from June 1999 to July 2014. We use several matches produced by this template as additional templates, iterating the process. Using this methodology, we identify over 300 DLP's. Events typically come in swarms lasting hours to days with no events exceeding magnitude 2. Swarms are separated by months to years of little detectable activity. A swarm of events on June 30, 2001 coincides with the Broadband Experiment Across the Alaska Range (BEAAR) seismic deployment, and was recorded by 15 broadband seismometers within 100 km of the epicenter. A preliminary waveform inversion for the focal mechanism of this event results in isotropic (implosive) and double couple components.We argue that these DLP's are evidence of magmatic or volatile movement through the sub-arc mantle wedge, even though there is no active volcanism at the surface. Relative relocations, utilizing cross correlated p- and s- waveforms, highlight a nest of seismicity with no structures such as planes or conduits. Lack of planar features, as well as the isotopic component and lack of strike slip to the focal mechanism, may argue against a deep extension of the Hines Creek or

  4. Active smart material system for buffet load alleviation

    NASA Astrophysics Data System (ADS)

    Lazarus, Kenneth B.; Saarmaa, Erik; Agnes, Gregory S.

    1995-05-01

    This paper addressed the feasibility of using an active piezoelectric buffet suppression system to reduce buffet vibrations in vertical tail aircraft. During the assessment, functional requirements were defined, models were developed, and full-scale piezoelectric buffet suppression systems were designed and evaluated. A variety of actuator distributions, sensor locations and controller architectures were examined and it was found that significant performance improvements could be achieved (greater than 70 percent) with minimal weight penalties (less than 8 percent). This work enabled the evaluation of issues such as system performance versus added weight and piezoelectric actuator control authority and power requirements. The study showed that the added performance benefit (in terms of vibration reduction and fatigue life) are far greater than the weight penalty, and that piezoelectric actuators have the control authority required to suppress high energy buffet forces within aircraft geometry, weight, and power constraints. Further, the high performance achieved (much greater than that defined in the functional requirements) suggests that systems can be designed with a much lower weight penalty (1/2 to 1/4) than that assumed in this study.

  5. Characteristics and antimicrobial activity of copper-based materials

    NASA Astrophysics Data System (ADS)

    Li, Bowen

    In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled particles, micron-sized copper vermiculite was prepared by jet-milling vermiculite. Meanwhile, since the exfoliated vermiculite has very unique properties, such as high porosity, specific surface area, high aspect ratio of laminates, and low density, and has been extensively utilized as a functional additives, exfoliated copper vermiculite also was synthesized and investigated. The antibacterial efficiency of copper vermiculite was qualitatively evaluated by the diffusion methods (both liquid diffusion and solid diffusion) against the most common pathogenic species: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Klebsiella pneumoniae (K. pneumoniae). The result showed that the release velocity of copper from copper vermiculite is very slow. However, copper vermiculite clearly has excellent antibacterial efficiency to S. aureus, K. pneumoniae and E. coli. The strongest antibacterial ability of copper vermiculite is its action on S. aureus. The antibacterial efficiency of copper vermiculite was also quantitatively evaluated by determining the reduction rate (death rate) of E. coli versus various levels of copper vermiculite. 10 ppm of copper vermiculite in solution is sufficient to reduce the cell population of E. coli, while the untreated vermiculite had no antibacterial activity. The slow release of copper revealed that the antimicrobial effect of copper vermiculite was due to the strong interactions between copper ions and bacteria cells. Exfoliated copper vermiculite has even stronger

  6. Inhaled nitric oxide alters the distribution of blood flow in the healthy human lung, suggesting active hypoxic pulmonary vasoconstriction in normoxia

    PubMed Central

    Asadi, Amran K.; Sá, Rui Carlos; Kim, Nick H.; Theilmann, Rebecca J.; Hopkins, Susan R.; Buxton, Richard B.

    2014-01-01

    Hypoxic pulmonary vasoconstriction (HPV) is thought to actively regulate ventilation-perfusion (V̇a/Q̇) matching, reducing perfusion in regions of alveolar hypoxia. We assessed the extent of HPV in the healthy human lung using inhaled nitric oxide (iNO) under inspired oxygen fractions (FiO2) of 0.125, 0.21, and 0.30 (a hyperoxic stimulus designed to abolish HPV without the development of atelectasis). Dynamic measures of blood flow were made in a single sagittal slice of the right lung of five healthy male subjects using an arterial spin labeling (ASL) MRI sequence, following a block stimulus pattern (3 × 60 breaths) with 40 ppm iNO administered in the central block. The overall spatial heterogeneity, spatiotemporal variability, and regional pattern of pulmonary blood flow was quantified as a function of condition (FiO2 × iNO state). While spatial heterogeneity did not change significantly with iNO administration or FiO2, there were statistically significant increases in Global Fluctuation Dispersion, (a marker of spatiotemporal flow variability) when iNO was administered during hypoxia (5.4 percentage point increase, P = 0.003). iNO had an effect on regional blood flow that was FiO2 dependent (P = 0.02), with regional changes in the pattern of blood flow occurring in hypoxia (P = 0.007) and normoxia (P = 0.008) tending to increase flow to dependent lung at the expense of nondependent lung. These findings indicate that inhaled nitric oxide significantly alters the distribution of blood flow in both hypoxic and normoxic healthy subjects, and suggests that some baseline HPV may indeed be present in the normoxic lung. PMID:25429099

  7. Open to Suggestion.

    ERIC Educational Resources Information Center

    Journal of Reading, 1981

    1981-01-01

    Contributors offer teaching ideas, including: using Sherlock Holmes mysteries to teach character and plot development, using materials supplied by the athletic coaches in the reading laboratory, and using individualized reading in the content areas. (AEA)

  8. E-Learning Activity-Based Material Recommendation System

    ERIC Educational Resources Information Center

    Liu, Feng-jung; Shih, Bai-jiun

    2007-01-01

    Purpose: Computer based systems have great potential for delivering learning material. However, problems are encountered, such as: difficulty of Learning resource sharing, high redundancy of learning material, and deficiency of the course brief. In order to solve these problems, this paper aims to propose an automatic inquiring system for learning…

  9. Anthropogenic activities have contributed moderately to increased inputs of organic materials in marginal seas off China.

    PubMed

    Liu, Liang-Ying; Wei, Gao-Ling; Wang, Ji-Zhong; Guan, Yu-Feng; Wong, Charles S; Wu, Feng-Chang; Zeng, Eddy Y

    2013-10-15

    Sediment has been recognized as a gigantic sink of organic materials and therefore can record temporal input trends. To examine the impact of anthropogenic activities on the marginal seas off China, sediment cores were collected from the Yellow Sea, the inner shelf of the East China Sea (ECS), and the South China Sea (SCS) to investigate the sources and spatial and temporal variations of organic materials, i.e., total organic carbon (TOC) and aliphatic hydrocarbons. The concentration ranges of TOC were 0.5-1.29, 0.63-0.83, and 0.33-0.85%, while those of Σn-C14-35 (sum of n-alkanes with carbon numbers of 14-35) were 0.08-1.5, 0.13-1.97, and 0.35-0.96 μg/g dry weight in sediment cores from the Yellow Sea, ECS inner shelf, and the SCS, respectively. Terrestrial higher plants were an important source of aliphatic hydrocarbons in marine sediments off China. The spatial distribution of Σn-C14-35 concentrations and source diagnostic ratios suggested a greater load of terrestrial organic materials in the Yellow Sea than in the ECS and SCS. Temporally, TOC and Σn-C14-35 concentrations increased with time and peaked at either the surface or immediate subsurface layers. This increase was probably reflective of elevated inputs of organic materials to marginal seas off China in recent years, and attributed partly to the impacts of intensified anthropogenic activities in mainland China. Source diagnostics also suggested that aliphatic hydrocarbons were mainly derived from biogenic sources, with a minority in surface sediment layers from petroleum sources, consistent with the above-mentioned postulation.

  10. Dissolution of a surfactant-containing active porous material.

    PubMed

    Brielles, Nelly; Chantraine, Florence; Viana, Marylène; Chulia, Dominique; Branlard, Paul; Rubinstenn, Gilles; Lequeux, François; Mondain-Monval, Olivier

    2008-12-15

    We have studied the imbibition and dissolution of a porous material in two separate scenarios: (1) when the porous material contains a surfactant powder and (2) when the porous material is dissolved in a surfactant solution. We show that the dissolution kinetics in both scenarios is significantly affected by the presence of the surfactant and results in an increase in the characteristic imbibition time of the porous material, which can be well understood in the framework of the classical law of capillarity. Slowing of the imbibition kinetics was found to be affected by a modification of the liquid wetting properties, but is also affected by a variation in the solubility of the porous material in the presence of the surfactant. Furthermore, there is a depletion effect of the surfactant inside the rising liquid, which is in good agreement with previous work and theoretical predictions.

  11. Chemistry Curricula. Course Suggestions.

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    Listings of suggested topics aimed at helping university and college faculties plan courses in the main areas of the chemistry curricula are provided. The suggestions were originally offered as appendices to the American Chemical Society's (ACS) Committee on Professional Training's 1983 guidelines for ACS-approved schools. The course data included…

  12. Analysis of Immune Response Markers in Jorge Lobo's Disease Lesions Suggests the Occurrence of Mixed T Helper Responses with the Dominance of Regulatory T Cell Activity.

    PubMed

    Azevedo, Michelle de C S; Rosa, Patricia S; Soares, Cleverson T; Fachin, Luciana R V; Baptista, Ida Maria F D; Woods, William J; Garlet, Gustavo P; Trombone, Ana Paula F; Belone, Andrea de F F

    2015-01-01

    Jorge Lobo's disease (JLD) is a chronic infection that affects the skin and subcutaneous tissues. Its etiologic agent is the fungus Lacazia loboi. Lesions are classified as localized, multifocal, or disseminated, depending on their location. Early diagnosis and the surgical removal of lesions are the best therapeutic options currently available for JLD. The few studies that evaluate the immunological response of JLD patients show a predominance of Th2 response, as well as a high frequency of TGF-β and IL-10 positive cells in the lesions; however, the overall immunological status of the lesions in terms of their T cell phenotype has yet to be determined. Therefore, the objective of this study was to evaluate the pattern of Th1, Th2, Th17 and regulatory T cell (Treg) markers mRNA in JLD patients by means of real-time PCR. Biopsies of JLD lesions (N = 102) were classified according to their clinical and histopathological features and then analyzed using real-time PCR in order to determine the expression levels of TGF-β1, FoxP3, CTLA4, IKZF2, IL-10, T-bet, IFN-γ, GATA3, IL-4, IL-5, IL-13, IL-33, RORC, IL-17A, IL-17F, and IL-22 and to compare these levels to those of healthy control skin (N = 12). The results showed an increased expression of FoxP3, CTLA4, TGF-β1, IL-10, T-bet, IL-17F, and IL-17A in lesions, while GATA3 and IL-4 levels were found to be lower in diseased skin than in the control group. When the clinical forms were compared, TGF-β1 was found to be highly expressed in patients with a single localized lesion while IL-5 and IL-17A levels were higher in patients with multiple/disseminated lesions. These results demonstrate the occurrence of mixed T helper responses and suggest the dominance of regulatory T cell activity, which could inhibit Th-dependent protective responses to intracellular fungi such as L. loboi. Therefore, Tregs may play a key role in JLD pathogenesis. PMID:26700881

  13. Analysis of Immune Response Markers in Jorge Lobo's Disease Lesions Suggests the Occurrence of Mixed T Helper Responses with the Dominance of Regulatory T Cell Activity

    PubMed Central

    Azevedo, Michelle de C. S.; Rosa, Patricia S.; Soares, Cleverson T.; Fachin, Luciana R. V.; Baptista, Ida Maria F. D.; Woods, William J.; Garlet, Gustavo P.

    2015-01-01

    Jorge Lobo’s disease (JLD) is a chronic infection that affects the skin and subcutaneous tissues. Its etiologic agent is the fungus Lacazia loboi. Lesions are classified as localized, multifocal, or disseminated, depending on their location. Early diagnosis and the surgical removal of lesions are the best therapeutic options currently available for JLD. The few studies that evaluate the immunological response of JLD patients show a predominance of Th2 response, as well as a high frequency of TGF-β and IL-10 positive cells in the lesions; however, the overall immunological status of the lesions in terms of their T cell phenotype has yet to be determined. Therefore, the objective of this study was to evaluate the pattern of Th1, Th2, Th17 and regulatory T cell (Treg) markers mRNA in JLD patients by means of real-time PCR. Biopsies of JLD lesions (N = 102) were classified according to their clinical and histopathological features and then analyzed using real-time PCR in order to determine the expression levels of TGF-β1, FoxP3, CTLA4, IKZF2, IL-10, T-bet, IFN-γ, GATA3, IL-4, IL-5, IL-13, IL-33, RORC, IL-17A, IL-17F, and IL-22 and to compare these levels to those of healthy control skin (N = 12). The results showed an increased expression of FoxP3, CTLA4, TGF-β1, IL-10, T-bet, IL-17F, and IL-17A in lesions, while GATA3 and IL-4 levels were found to be lower in diseased skin than in the control group. When the clinical forms were compared, TGF-β1 was found to be highly expressed in patients with a single localized lesion while IL-5 and IL-17A levels were higher in patients with multiple/disseminated lesions. These results demonstrate the occurrence of mixed T helper responses and suggest the dominance of regulatory T cell activity, which could inhibit Th-dependent protective responses to intracellular fungi such as L. loboi. Therefore, Tregs may play a key role in JLD pathogenesis. PMID:26700881

  14. Analysis of Immune Response Markers in Jorge Lobo's Disease Lesions Suggests the Occurrence of Mixed T Helper Responses with the Dominance of Regulatory T Cell Activity.

    PubMed

    Azevedo, Michelle de C S; Rosa, Patricia S; Soares, Cleverson T; Fachin, Luciana R V; Baptista, Ida Maria F D; Woods, William J; Garlet, Gustavo P; Trombone, Ana Paula F; Belone, Andrea de F F

    2015-01-01

    Jorge Lobo's disease (JLD) is a chronic infection that affects the skin and subcutaneous tissues. Its etiologic agent is the fungus Lacazia loboi. Lesions are classified as localized, multifocal, or disseminated, depending on their location. Early diagnosis and the surgical removal of lesions are the best therapeutic options currently available for JLD. The few studies that evaluate the immunological response of JLD patients show a predominance of Th2 response, as well as a high frequency of TGF-β and IL-10 positive cells in the lesions; however, the overall immunological status of the lesions in terms of their T cell phenotype has yet to be determined. Therefore, the objective of this study was to evaluate the pattern of Th1, Th2, Th17 and regulatory T cell (Treg) markers mRNA in JLD patients by means of real-time PCR. Biopsies of JLD lesions (N = 102) were classified according to their clinical and histopathological features and then analyzed using real-time PCR in order to determine the expression levels of TGF-β1, FoxP3, CTLA4, IKZF2, IL-10, T-bet, IFN-γ, GATA3, IL-4, IL-5, IL-13, IL-33, RORC, IL-17A, IL-17F, and IL-22 and to compare these levels to those of healthy control skin (N = 12). The results showed an increased expression of FoxP3, CTLA4, TGF-β1, IL-10, T-bet, IL-17F, and IL-17A in lesions, while GATA3 and IL-4 levels were found to be lower in diseased skin than in the control group. When the clinical forms were compared, TGF-β1 was found to be highly expressed in patients with a single localized lesion while IL-5 and IL-17A levels were higher in patients with multiple/disseminated lesions. These results demonstrate the occurrence of mixed T helper responses and suggest the dominance of regulatory T cell activity, which could inhibit Th-dependent protective responses to intracellular fungi such as L. loboi. Therefore, Tregs may play a key role in JLD pathogenesis.

  15. Microscopic theory of the glassy dynamics of passive and active network materials.

    PubMed

    Wang, Shenshen; Wolynes, Peter G

    2013-03-28

    Signatures of glassy dynamics have been identified experimentally for a rich variety of materials in which molecular networks provide rigidity. Here we present a theoretical framework to study the glassy behavior of both passive and active network materials. We construct a general microscopic network model that incorporates nonlinear elasticity of individual filaments and steric constraints due to crowding. Based on constructive analogies between structural glass forming liquids and random field Ising magnets implemented using a heterogeneous self-consistent phonon method, our scheme provides a microscopic approach to determine the mismatch surface tension and the configurational entropy, which compete in determining the barrier for structural rearrangements within the random first order transition theory of escape from a local energy minimum. The influence of crosslinking on the fragility of inorganic network glass formers is recapitulated by the model. For active network materials, the mapping, which correlates the glassy characteristics to the network architecture and properties of nonequilibrium motor processes, is shown to capture several key experimental observations on the cytoskeleton of living cells: Highly connected tense networks behave as strong glass formers; intense motor action promotes reconfiguration. The fact that our model assuming a negative motor susceptibility predicts the latter suggests that on average the motorized processes in living cells do resist the imposed mechanical load. Our calculations also identify a spinodal point where simultaneously the mismatch penalty vanishes and the mechanical stability of amorphous packing disappears.

  16. Electron-beam activated thermal sputtering of thermoelectric materials

    SciTech Connect

    Wu Jinsong; Dravid, Vinayak P.; He Jiaqing; Han, Mi-Kyung; Sootsman, Joseph R.; Girard, Steven; Arachchige, Indika U.; Kanatzidis, Mercouri G.

    2011-08-15

    Thermoelectricity and Seebeck effect have long been observed and validated in bulk materials. With the development of advanced tools of materials characterization, here we report the first observation of such an effect in the nanometer scale: in situ directional sputtering of several thermoelectric materials inside electron microscopes. The temperature gradient introduced by the electron beam creates a voltage-drop across the samples, which enhances spontaneous sputtering of specimen ions. The sputtering occurs along a preferential direction determined by the direction of the temperature gradient. A large number of nanoparticles form and accumulate away from the beam location as a result. The sputtering and re-crystallization are found to occur at temperatures far below the melting points of bulk materials. The sputtering occurs even when a liquid nitrogen cooling holder is used to keep the overall temperature at -170 deg. C. This unique phenomenon that occurred in the nanometer scale may provide useful clues to understanding the mechanism of thermoelectric effect.

  17. Electron-beam activated thermal sputtering of thermoelectric materials.

    SciTech Connect

    Wu, J.; He, J.; Han, M-K.; Sootsman, J. R.; Girard, S.; Arachchige, I. U.; Kanatzidis, M. G.; Dravid, V. P.

    2011-08-01

    Thermoelectricity and Seebeck effect have long been observed and validated in bulk materials. With the development of advanced tools of materials characterization, here we report the first observation of such an effect in the nanometer scale: in situ directional sputtering of several thermoelectric materials inside electron microscopes. The temperature gradient introduced by the electron beam creates a voltage-drop across the samples, which enhances spontaneous sputtering of specimen ions. The sputtering occurs along a preferential direction determined by the direction of the temperature gradient. A large number of nanoparticles form and accumulate away from the beam location as a result. The sputtering and re-crystallization are found to occur at temperatures far below the melting points of bulk materials. The sputtering occurs even when a liquid nitrogen cooling holder is used to keep the overall temperature at -170 C. This unique phenomenon that occurred in the nanometer scale may provide useful clues to understanding the mechanism of thermoelectric effect.

  18. Open to Suggestion.

    ERIC Educational Resources Information Center

    Journal of Reading, 1984

    1984-01-01

    Contributors offer suggestions concerning parents as reading stimulators, book discussions, a test bank for the secondary school/college reading lab, standardized reading tests, television reading, plagiarism, vocabulary development, and book reports. (FL)

  19. [Therapy and suggestion].

    PubMed

    Barrucand, D; Paille, F

    1986-12-01

    Therapy and suggestion are closely related. That is clear for the ancient time: primitive medicine gives a good place to the Word. In plant, animal or mineral remedies, the suggestion is clearly preponderant. Towards the end of the 19th century, the "Ecole de Nancy" sets up a real theory of the suggestion, and Bernheim, its leader, bases hypnosis, then psychotherapy on this concept. Thereafter Coué will bring up the "conscious autosuggestion". Today, despite the progress of scientific medicine, the part of suggestion is still very important in medical therapy (with or without drugs), or in chirurgical therapy; this part is also very important in psychotherapies, whatever has been said in this field. This has to be known and used consciously in the doctor-patient relation, which is always essential in the therapeutic effectiveness.

  20. Characteristics and antimicrobial activity of copper-based materials

    NASA Astrophysics Data System (ADS)

    Li, Bowen

    In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled particles, micron-sized copper vermiculite was prepared by jet-milling vermiculite. Meanwhile, since the exfoliated vermiculite has very unique properties, such as high porosity, specific surface area, high aspect ratio of laminates, and low density, and has been extensively utilized as a functional additives, exfoliated copper vermiculite also was synthesized and investigated. The antibacterial efficiency of copper vermiculite was qualitatively evaluated by the diffusion methods (both liquid diffusion and solid diffusion) against the most common pathogenic species: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Klebsiella pneumoniae (K. pneumoniae). The result showed that the release velocity of copper from copper vermiculite is very slow. However, copper vermiculite clearly has excellent antibacterial efficiency to S. aureus, K. pneumoniae and E. coli. The strongest antibacterial ability of copper vermiculite is its action on S. aureus. The antibacterial efficiency of copper vermiculite was also quantitatively evaluated by determining the reduction rate (death rate) of E. coli versus various levels of copper vermiculite. 10 ppm of copper vermiculite in solution is sufficient to reduce the cell population of E. coli, while the untreated vermiculite had no antibacterial activity. The slow release of copper revealed that the antimicrobial effect of copper vermiculite was due to the strong interactions between copper ions and bacteria cells. Exfoliated copper vermiculite has even stronger

  1. Massachusetts and the Bill of Rights. A Teacher's Manual with Suggested Activities and Resources for the Bill of Rights Bicentennial and Supplement to the "By What Right" Video.

    ERIC Educational Resources Information Center

    Robinson, Barbara

    This document, a teacher's manual, was published as part of the state of Massachusetts' observance of the bicentennial of the United States Constitution. The manual accompanies a videotape on the topic. Together, the materials can help educators identify the people, places, and pictures that they can use to underscore the significance of the Bill…

  2. Precursor complex structure of pseudouridine synthase TruB suggests coupling of active site perturbations to an RNA-sequestering peripheral protein domain.

    PubMed

    Hoang, Charmaine; Hamilton, Christopher S; Mueller, Eugene G; Ferré-D'Amaré, Adrian R

    2005-08-01

    The pseudouridine synthase TruB is responsible for the universally conserved post-transcriptional modification of residue 55 of elongator tRNAs. In addition to the active site, the "thumb", a peripheral domain unique to the TruB family of enzymes, makes extensive interactions with the substrate. To coordinate RNA binding and release with catalysis, the thumb may be able to sense progress of the reaction in the active site. To establish whether there is a structural correlate of communication between the active site and the RNA-sequestering thumb, we have solved the structure of a catalytically inactive point mutant of TruB in complex with a substrate RNA, and compared it to the previously determined structure of an active TruB bound to a reaction product. Superposition of the two structures shows that they are extremely similar, except in the active site and, intriguingly, in the relative position of the thumb. Because the two structures were solved using isomorphous crystals, and because the thumb is very well ordered in both structures, the displacement of the thumb we observe likely reflects preferential propagation of active site perturbations to this RNA-binding domain. One of the interactions between the active site and the thumb involves an active site residue whose hydrogen-bonding status changes during the reaction. This may allow the peripheral RNA-binding domain to monitor progress of the pseudouridylation reaction.

  3. Chemically active organically doped sol-gel materials: enzymatic sensors, chemical sensors, and photoactive materials

    NASA Astrophysics Data System (ADS)

    Avnir, David; Braun, S.; Lev, Ovadia; Ottolenghi, M.

    1992-12-01

    Organically-doped porous sol-gel matrices of optical grade have evolved in recent years into a wide class of materials with diverse applications. We review recent progress made in our laboratories in three domains of applications: the trapping of enzymes with the consequent design of (e.g. glucose) sensors; the development of chemical sensors; and the design of photoactive material for (solar) light energy conversion.

  4. NASA's activities in the conservation of strategic aerospace materials

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1980-01-01

    The United States imports 50-100 percent of certain metals critical to the aerospace industry, namely, cobalt, columbium, chromium, and tantalum. In an effort to reduce this dependence on foreign sources, NASA is planning a program called Conservation of Strategic Aerospace Materials (COSAM), which will provide technology minimizing strategic metal content in the components of aerospace structures such as aircraft engines. With a proposed starting date of October 1981, the program will consist of strategic element substitution, process technology development, and alternate materials research. NASA's two-fold pre-COSAM studies center on, first, substitution research involving nickel-base and cobalt-base superalloys (Waspaloy, Udimet-700, MAE-M247, Rene 150, HA-188) used in turbine disks, low-pressure blades, turbine blades, and combustors; and, second, alternate materials research devoted initially to investigating possible structural applications of the intermetallic alloys nickel aluminide and iron aluminide.

  5. Transfer having a coupling coefficient higher than its active material

    NASA Technical Reports Server (NTRS)

    Lesieutre, George A. (Inventor); Davis, Christopher L. (Inventor)

    2001-01-01

    A coupling coefficient is a measure of the effectiveness with which a shape-changing material (or a device employing such a material) converts the energy in an imposed signal to useful mechanical energy. Device coupling coefficients are properties of the device and, although related to the material coupling coefficients, are generally different from them. This invention describes a class of devices wherein the apparent coupling coefficient can, in principle, approach 1.0, corresponding to perfect electromechanical energy conversion. The key feature of this class of devices is the use of destabilizing mechanical pre-loads to counter inherent stiffness. The approach is illustrated for piezoelectric and thermoelectrically actuated devices. The invention provides a way to simultaneously increase both displacement and force, distinguishing it from alternatives such as motion amplification, and allows transducer designers to achieve substantial performance gains for actuator and sensor devices.

  6. Review of activities in USA on HTS materials

    SciTech Connect

    Peterson, D.E.

    1995-02-01

    Rapid progress in attaining practical applications of High Temperature Superconductors (HTS) has been made since the discovery of these new materials. Many critical parameters influencing HTS powder synthesis and wire processing have been identified through a combination of fundamental exploration and applied research. The complexity of these novel materials with regard to phase behavior and physical properties has become evident as a result of these careful studies. Achieving optimal mechanical and superconducting properties in wires and tapes will require further understanding and synergy among several different technical disciplines. Highlights of efforts towards producing practical superconductors for electric power applications based on rare earth-, bismuth-, and thallium-based systems are reviewed.

  7. Examination of the haemolytic activity of sol-gel materials

    NASA Astrophysics Data System (ADS)

    Ulatowska-Jarza, Agnieszka; Podbielska, Halina; Holowacz, Iwona; Lechna-Marczynska, Monika I.; Szymonowicz, Maria; Staniszewska-Kus, Jolanta; Paluch, Danuta

    2001-10-01

    Recently, the sol-gel based biomaterials are extendedly investigated with emphasis on theirs various applications, including medical ones. In this respect it is important to investigate the influence of sol-gel matrices on biological systems. The results of laboratory and biological testing of aqueous extracts of sol-gels are presented in this work. It was proved that it is possible to produce the sol-gel derived materials that will be non-haemolytic. This can be achieved by heating the materials in elevated temperatures. This effect can also be reached by suitably long aging (minimum 6 months).

  8. Cosmogenic activation of materials used in rare event search experiments

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Mei, D.-M.; Kudryavtsev, V. A.; Fiorucci, S.

    2016-11-01

    We evaluate the cosmogenic production rates in some materials that are commonly used as targets and shielding/supporting components for detecting rare events. The results from Geant4 simulations and the calculations of ACTIVIA are compared with the available experimental data. We demonstrate that the production rates from the Geant4-based simulations agree with the available data reasonably well. As a result, we report that the cosmogenic production of several isotopes in various materials can generate potential backgrounds for direct detection of dark matter and neutrinoless double-beta decay.

  9. Job Creation: Creative Materials, Activities, & Strategies for the Classroom.

    ERIC Educational Resources Information Center

    Smutny, Joan Franklin; And Others

    Designed for use by high school students, their teachers, and counselors, these six learning modules contain creative materials to encourage individuals to think about their own talents, skills, interests, and capacities for job creation. Each module consists of student worksheets and teacher guides. Covered in the first five modules are the…

  10. Turkish EFL Academicians' Problems Concerning Translation Activities and Practices, Attitudes towards the Use of Online and Printed Translation Tools, and Suggestions for Quality Translation Practice

    ERIC Educational Resources Information Center

    Zengin, Bugra; Kacar, Isil Gunseli

    2011-01-01

    This mixed method research study aimed to highlight the problems of EFL academicians concerning their current translation practices, their attitudes towards the use of various translation tools, and offer suggestions for more quality translation practices. Seventy-three EFL academicians from three Turkish universities participated in the study.…

  11. A few minor suggestions.

    PubMed

    Michael, J; Clark, J W

    2001-05-01

    We agree with almost all of the analysis in this excellent presentation of the molecular view of avoidance behavior. A few suggestions are made as follows: Referring to response-generated stimuli as ''readily observable" seems not quite right for the kinesthetic components of such stimuli, although their scientific legitimacy is not questioned. Interpreting response-generated stimuli as a form of positive reinforcement is contested, and an alternative interpretation is offered. A possibly simpler interpretation of the Sidman (1962) two-lever experiment is suggested. We question Dinsmoor's (2001) explanation for warning stimuli not being avoided, except for the reference to the weakness of third-order conditioning effects. A final question is raised regarding the nature of the variables that are responsible for the momentary evocation of the avoidance response.

  12. Open to Suggestion.

    ERIC Educational Resources Information Center

    Journal of Reading, 1991

    1991-01-01

    Presents five class activities involving (1) using paraphrasing cards to reduce unintentional plagiarism; (2) using cartoons to improve content reading; (3) scaffolding; (4) the Neurological Impress method and middle school readers; and (5) newspapers for adults with reading difficulties. Discusses what keeps adults out of adult education programs…

  13. Open to Suggestion.

    ERIC Educational Resources Information Center

    Journal of Reading, 1987

    1987-01-01

    Recounts the use of: (1) a game of reading trivia to review a unit in reading, (2) a reading-related art activity that emphasized the importance of following directions, and (3) the assignment of a research paper in a remedial curriculum. (NKA)

  14. Review of smart material technologies for active parachute applications

    NASA Astrophysics Data System (ADS)

    Favini, Eric; Niezrecki, Christopher; Chen, Julie; Willis, David; Niemi, Eugene; Desabrais, Kenneth

    2010-04-01

    The performance (drag, lift, stability, etc.) of a parachute is a function of the physical properties of the canopy fabric (such as porosity) and geometry of the canopy (such as air-vent openings). These variables typically remain constant during descent and therefore the parachute retains constant drag and lift. The ability to change these variables and the parachute drag and lift characteristics during flight will greatly widen the performance envelope of a parachute, the maneuverability, and versatility of the airdrop mission. This paper provides a literature review of existing smart material technologies in an effort to improve the performance characteristics and enhance the safety of existing parachutes and parafoils by incorporating these advanced materials into parachute systems.

  15. NASA's activities in the conservation of strategic aerospace materials

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1980-01-01

    The primary objective of the Conservation of Strategic Aerospace Materials (COSAM) Program is to help reduce the dependence of the United States aerospace industry on strategic metals by providing the materials technology needed to minimize the strategic metal content of critical aerospace components with prime emphasis on components for gas turbine engines. Initial emphasis was placed in the area of strategic element substinction. Specifically, the role of cobalt in nickel base and cobalt base superalloys vital to the aerospace industry is being examined in great detail by means of cooperative university-industry-government research efforts. Investigations are underway in the area of "new classes" of alloys. Specifically, a study was undertaken to investigate the mechanical and physical properties of intermetallics that contain a minimum of the strategic metals. Current plans for the much larger COSAM Program are also presented.

  16. Attenuated and lethal variants of Pichindé virus induce differential patterns of NF-kappaB activation suggesting a potential target for novel therapeutics.

    PubMed

    Bowick, Gavin C; Fennewald, Susan M; Zhang, Lihong; Yang, Xianbin; Aronson, Judith F; Shope, Robert E; Luxon, Bruce A; Gorenstein, David G; Herzog, Norbert K

    2009-12-01

    Lassa virus pathogenesis is believed to involve dysregulation of cytokines. We have previously shown nuclear factor-kappaB (NF-kappaB) inhibition using a BSL-2 model for Lassa fever. Here we further define the potential mechanism for NF-kappaB inhibition as involving increased levels of repressive p50/p50 homodimers, and suggest a novel therapeutic strategy that acts via modulation of host signaling.

  17. Passive and active sol-gel materials and devices

    NASA Astrophysics Data System (ADS)

    Andrews, Mark P.; Najafi, S. Iraj

    1997-07-01

    This paper examines sol-gel materials for photonics in terms of partnerships with other material contenders for processing optical devices. The discussion in four sections identifies semiconductors, amorphous and crystalline inorganic dielectrics, and amorphous and crystalline organic dielectrics as strategic agents in the rapidly evolving area of materials and devices for data communications and telecommunications. With Zyss, we trace the hierarchical lineage that connects molecular hybridization (chemical functionality), through supramolecular hybridization (collective properties and responses), to functional hybridization (device and system level constructs). These three concepts thread their way through discussions of the roles sol-gel glasses might be anticipated to assume in a photonics marketplace. We assign a special place to glass integrated optics and show how high temperature consolidated sol-gel derived glasses fit into competitive glass fabrication technologies. Low temperature hybrid sol-gel glasses that combine attractive features of organic polymers and inorganic glasses are considered by drawing on examples of our own new processes for fabricating couplers, power splitters, waveguides and gratings by combining chemical synthesis and sol-gel processing with simple photomask techniques.

  18. Activities.

    ERIC Educational Resources Information Center

    Mathematics Teacher, 1982

    1982-01-01

    The material presented is designed to help students explore geometric patterns involving Fibonnaci numbers and the golden ratio, and to aid in review of basic geometry skills. Worksheet masters intended for duplication are provided. Suggestions are made of possible classroom extensions to the initial activities. (MP)

  19. 77 FR 24269 - Proposed Information Collection (Description of Materials) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... information needed to determine if proposed construction material meets regulatory requirements and if the...-1852 is used to document material used in the construction of a dwelling or specially adapted housing... AFFAIRS Proposed Information Collection (Description of Materials) Activity: Comment Request...

  20. An exploratory intervention study suggests clinical benefits of training in chronic stroke to be paralleled by changes in brain activity using repeated fMRI

    PubMed Central

    Landsmann, Barbara; Pinter, Daniela; Pirker, Eva; Pichler, Gerald; Schippinger, Walter; Weiss, Elisabeth M; Mathie, Gabriel; Gattringer, Thomas; Fazekas, Franz; Enzinger, Christian

    2016-01-01

    Purpose Previous studies demonstrated changes in sensorimotor network activation over time after stroke that have been interpreted as partly compensatory. Locomotor and balance trainings may improve both mobility and cognition even in chronic stroke and thereby impact on cerebral activation patterns. We here aimed at testing these assumptions in an exploratory study to inform subsequent larger intervention studies. Patients and methods Eight patients (73.3±4.4 years) with a chronic lacunar stroke (mean interval 3.7 years after the acute event with a range from 2 to 4 years) and residual leg paresis leading to gait disturbance received a guided 5-week training focusing on mobility, endurance, and coordination. Before and afterward, they underwent clinical, neuropsychological, and gait assessments and brain MRI at 3 T including a functional ankle movement paradigm. Sixteen healthy controls (HCs; 68.8±5.4 years) followed the same protocol without intervention. Results After training, patients had improved in mobility, memory, and delayed recall of memory. While cerebral activations in HC remained completely unaltered, patients showed increased activations in the right precentral gyrus, the right and left superior frontal gyri, and the right frontal lobe, with bipedal ankle movements after training. Conclusion In this exploratory study of chronic stroke, we found not only significant effects of physical training on mobility but also distinct aspects of cognition already with a small number of highly selected patients. These improvements were paralleled by alterations in cerebral activity possibly reflecting neuronal plasticity. Larger studies including randomization are needed. PMID:26869779

  1. Materials for Consideration in Standardized Canister Design Activities.

    SciTech Connect

    Bryan, Charles R.; Ilgen, Anastasia Gennadyevna; Enos, David George; Teich-McGoldrick, Stephanie; Hardin, Ernest

    2014-10-01

    This document identifies materials and material mitigation processes that might be used in new designs for standardized canisters for storage, transportation, and disposal of spent nuclear fuel. It also addresses potential corrosion issues with existing dual-purpose canisters (DPCs) that could be addressed in new canister designs. The major potential corrosion risk during storage is stress corrosion cracking of the weld regions on the 304 SS/316 SS canister shell due to deliquescence of chloride salts on the surface. Two approaches are proposed to alleviate this potential risk. First, the existing canister materials (304 and 316 SS) could be used, but the welds mitigated to relieve residual stresses and/or sensitization. Alternatively, more corrosion-resistant steels such as super-austenitic or duplex stainless steels, could be used. Experimental testing is needed to verify that these alternatives would successfully reduce the risk of stress corrosion cracking during fuel storage. For disposal in a geologic repository, the canister will be enclosed in a corrosion-resistant or corrosion-allowance overpack that will provide barrier capability and mechanical strength. The canister shell will no longer have a barrier function and its containment integrity can be ignored. The basket and neutron absorbers within the canister have the important role of limiting the possibility of post-closure criticality. The time period for corrosion is much longer in the post-closure period, and one major unanswered question is whether the basket materials will corrode slowly enough to maintain structural integrity for at least 10,000 years. Whereas there is extensive literature on stainless steels, this evaluation recommends testing of 304 and 316 SS, and more corrosion-resistant steels such as super-austenitic, duplex, and super-duplex stainless steels, at repository-relevant physical and chemical conditions. Both general and localized corrosion testing methods would be used to

  2. Pattern Triggered Immunity (PTI) in Tobacco: Isolation of Activated Genes Suggests Role of the Phenylpropanoid Pathway in Inhibition of Bacterial Pathogens

    PubMed Central

    Szatmári, Ágnes; Zvara, Ágnes; Móricz, Ágnes M.; Besenyei, Eszter; Szabó, Erika; Ott, Péter G.; Puskás, László G.; Bozsó, Zoltán

    2014-01-01

    Background Pattern Triggered Immunity (PTI) or Basal Resistance (BR) is a potent, symptomless form of plant resistance. Upon inoculation of a plant with non-pathogens or pathogenicity-mutant bacteria, the induced PTI will prevent bacterial proliferation. Developed PTI is also able to protect the plant from disease or HR (Hypersensitive Response) after a challenging infection with pathogenic bacteria. Our aim was to reveal those PTI-related genes of tobacco (Nicotiana tabacum) that could possibly play a role in the protection of the plant from disease. Methodology/Principal Findings Leaves were infiltrated with Pseudomonas syringae pv. syringae hrcC- mutant bacteria to induce PTI, and samples were taken 6 and 48 hours later. Subtraction Suppressive Hybridization (SSH) resulted in 156 PTI-activated genes. A cDNA microarray was generated from the SSH clone library. Analysis of hybridization data showed that in the early (6 hpi) phase of PTI, among others, genes of peroxidases, signalling elements, heat shock proteins and secondary metabolites were upregulated, while at the late phase (48 hpi) the group of proteolysis genes was newly activated. Microarray data were verified by real time RT-PCR analysis. Almost all members of the phenyl-propanoid pathway (PPP) possibly leading to lignin biosynthesis were activated. Specific inhibition of cinnamic-acid-4-hydroxylase (C4H), rate limiting enzyme of the PPP, decreased the strength of PTI - as shown by the HR-inhibition and electrolyte leakage tests. Quantification of cinnamate and p-coumarate by thin-layer chromatography (TLC)-densitometry supported specific changes in the levels of these metabolites upon elicitation of PTI. Conclusions/Significance We believe to provide first report on PTI-related changes in the levels of these PPP metabolites. Results implicated an actual role of the upregulation of the phenylpropanoid pathway in the inhibition of bacterial pathogenic activity during PTI. PMID:25101956

  3. Structure of Membrane-active Toxin from Crab Spider Heriaeus melloteei Suggests Parallel Evolution of Sodium Channel Gating Modifiers in Araneomorphae and Mygalomorphae*

    PubMed Central

    Berkut, Antonina A.; Peigneur, Steve; Myshkin, Mikhail Yu.; Paramonov, Alexander S.; Lyukmanova, Ekaterina N.; Arseniev, Alexander S.; Grishin, Eugene V.; Tytgat, Jan; Shenkarev, Zakhar O.; Vassilevski, Alexander A.

    2015-01-01

    We present a structural and functional study of a sodium channel activation inhibitor from crab spider venom. Hm-3 is an insecticidal peptide toxin consisting of 35 amino acid residues from the spider Heriaeus melloteei (Thomisidae). We produced Hm-3 recombinantly in Escherichia coli and determined its structure by NMR spectroscopy. Typical for spider toxins, Hm-3 was found to adopt the so-called “inhibitor cystine knot” or “knottin” fold stabilized by three disulfide bonds. Its molecule is amphiphilic with a hydrophobic ridge on the surface enriched in aromatic residues and surrounded by positive charges. Correspondingly, Hm-3 binds to both neutral and negatively charged lipid vesicles. Electrophysiological studies showed that at a concentration of 1 μm Hm-3 effectively inhibited a number of mammalian and insect sodium channels. Importantly, Hm-3 shifted the dependence of channel activation to more positive voltages. Moreover, the inhibition was voltage-dependent, and strong depolarizing prepulses attenuated Hm-3 activity. The toxin is therefore concluded to represent the first sodium channel gating modifier from an araneomorph spider and features a “membrane access” mechanism of action. Its amino acid sequence and position of the hydrophobic cluster are notably different from other known gating modifiers from spider venom, all of which are described from mygalomorph species. We hypothesize parallel evolution of inhibitor cystine knot toxins from Araneomorphae and Mygalomorphae suborders. PMID:25352595

  4. Structure of membrane-active toxin from crab spider Heriaeus melloteei suggests parallel evolution of sodium channel gating modifiers in Araneomorphae and Mygalomorphae.

    PubMed

    Berkut, Antonina A; Peigneur, Steve; Myshkin, Mikhail Yu; Paramonov, Alexander S; Lyukmanova, Ekaterina N; Arseniev, Alexander S; Grishin, Eugene V; Tytgat, Jan; Shenkarev, Zakhar O; Vassilevski, Alexander A

    2015-01-01

    We present a structural and functional study of a sodium channel activation inhibitor from crab spider venom. Hm-3 is an insecticidal peptide toxin consisting of 35 amino acid residues from the spider Heriaeus melloteei (Thomisidae). We produced Hm-3 recombinantly in Escherichia coli and determined its structure by NMR spectroscopy. Typical for spider toxins, Hm-3 was found to adopt the so-called "inhibitor cystine knot" or "knottin" fold stabilized by three disulfide bonds. Its molecule is amphiphilic with a hydrophobic ridge on the surface enriched in aromatic residues and surrounded by positive charges. Correspondingly, Hm-3 binds to both neutral and negatively charged lipid vesicles. Electrophysiological studies showed that at a concentration of 1 μm Hm-3 effectively inhibited a number of mammalian and insect sodium channels. Importantly, Hm-3 shifted the dependence of channel activation to more positive voltages. Moreover, the inhibition was voltage-dependent, and strong depolarizing prepulses attenuated Hm-3 activity. The toxin is therefore concluded to represent the first sodium channel gating modifier from an araneomorph spider and features a "membrane access" mechanism of action. Its amino acid sequence and position of the hydrophobic cluster are notably different from other known gating modifiers from spider venom, all of which are described from mygalomorph species. We hypothesize parallel evolution of inhibitor cystine knot toxins from Araneomorphae and Mygalomorphae suborders.

  5. Activated Charcoal—A Potential Material in Glucoamylase Recovery

    PubMed Central

    Kareem, S. O.; Akpan, I.; Popoola, T. O. S.; Sanni, L. O.

    2011-01-01

    The potential of activated charcoal in the purification of fungal glucoamylase was investigated. Various concentrations of activated charcoal (1–4% w/v) were used to concentrate crude glucoamylase from Rhizopus oligosporus at different temperature values (30–50°C). Effects of pH (3.0–6.0) and contact time (0–60 min) on enzyme purification were also monitored. Activated charcoal (3% w/v) gave a 16-fold purification in a single-step purification at 50°C for 20 min and pH 5.5. The result of SDS-PAGE analysis of purified glucoamylase showed two major protein bands with corresponding molecular weight of 36 kDa and 50 kDa. The method is inexpensive, rapid, and simple which could facilitate downstream processing of industrial enzyme. PMID:22235364

  6. Using luminescent materials as the active element for radiation sensors

    NASA Astrophysics Data System (ADS)

    Hollerman, William A.; Fontenot, Ross S.; Williams, Stephen; Miller, John

    2016-05-01

    Ionizing radiation poses a significant challenge for Earth-based defense applications as well as human and/or robotic space missions. Practical sensors based on luminescence will depend heavily upon research investigating the resistance of these materials to ionizing radiation and the ability to anneal or self-heal from damage caused by such radiation. In 1951, Birks and Black showed experimentally that the luminescent efficiency of anthracene bombarded by alphas varies with total fluence (N) as (I/I0) = 1/(1 + AN), where I is the luminescence yield, I0 is the initial yield, and A is a constant. The half brightness (N1/2) is defined as the fluence that reduce the emission light yield to half and is equal to is the inverse of A. Broser and Kallmann developed a similar relationship to the Birks and Black equation for inorganic phosphors irradiated using alpha particles. From 1990 to the present, we found that the Birks and Black relation describes the reduction in light emission yield for every tested luminescent material except lead phosphate glass due to proton irradiation. These results indicate that radiation produced quenching centers compete with emission for absorbed energy. The purpose of this paper is to present results from research completed in this area over the last few years. Particular emphasis will be placed on recent measurements made on new materials such as europium tetrakis dibenzoylmethide triethylammonium (EuD4TEA). Results have shown that EuD4TEA with its relatively small N1/2 might be a good candidate for use as a personal proton fluence sensor.

  7. Activated carbon fiber composite material and method of making

    DOEpatents

    Burchell, Timothy D.; Weaver, Charles E.; Chilcoat, Bill R.; Derbyshire, Frank; Jagtoyen, Marit

    2000-01-01

    An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

  8. Activated carbon fiber composite material and method of making

    DOEpatents

    Burchell, Timothy D.; Weaver, Charles E.; Chilcoat, Bill R.; Derbyshire, Frank; Jagtoyen, Marit

    2001-01-01

    An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

  9. Secretion of Antonospora (Paranosema) locustae proteins into infected cells suggests an active role of microsporidia in the control of host programs and metabolic processes.

    PubMed

    Senderskiy, Igor V; Timofeev, Sergey A; Seliverstova, Elena V; Pavlova, Olga A; Dolgikh, Viacheslav V

    2014-01-01

    Molecular tools of the intracellular protozoan pathogens Apicomplexa and Kinetoplastida for manipulation of host cell machinery have been the focus of investigation for approximately two decades. Microsporidia, fungi-related microorganisms forming another large group of obligate intracellular parasites, are characterized by development in direct contact with host cytoplasm (the majority of species), strong minimization of cell machinery, and acquisition of unique transporters to exploit host metabolic system. All the aforementioned features are suggestive of the ability of microsporidia to modify host metabolic and regulatory pathways. Seven proteins of the microsporidium Antonospora (Paranosema) locustae with predicted signal peptides but without transmembrane domains were overexpressed in Escherichia coli. Western-blot analysis with antibodies against recombinant products showed secretion of parasite proteins from different functional categories into the infected host cell. Secretion of parasite hexokinase and α/β-hydrolase was confirmed by immunofluorescence microscopy. In addition, this method showed specific accumulation of A. locustae hexokinase in host nuclei. Expression of hexokinase, trehalase, and two leucine-rich repeat proteins without any exogenous signal peptide led to their secretion in the yeast Pichia pastoris. In contrast, α/β-hydrolase was not found in the culture medium, though a significant amount of this enzyme accumulated in the yeast membrane fraction. These results suggest that microsporidia possess a broad set of enzymes and regulatory proteins secreted into infected cells to control host metabolic processes and molecular programs. PMID:24705470

  10. Secretion of Antonospora (Paranosema) locustae Proteins into Infected Cells Suggests an Active Role of Microsporidia in the Control of Host Programs and Metabolic Processes

    PubMed Central

    Senderskiy, Igor V.; Timofeev, Sergey A.; Seliverstova, Elena V.; Pavlova, Olga A.; Dolgikh, Viacheslav V.

    2014-01-01

    Molecular tools of the intracellular protozoan pathogens Apicomplexa and Kinetoplastida for manipulation of host cell machinery have been the focus of investigation for approximately two decades. Microsporidia, fungi-related microorganisms forming another large group of obligate intracellular parasites, are characterized by development in direct contact with host cytoplasm (the majority of species), strong minimization of cell machinery, and acquisition of unique transporters to exploit host metabolic system. All the aforementioned features are suggestive of the ability of microsporidia to modify host metabolic and regulatory pathways. Seven proteins of the microsporidium Antonospora (Paranosema) locustae with predicted signal peptides but without transmembrane domains were overexpressed in Escherichia coli. Western-blot analysis with antibodies against recombinant products showed secretion of parasite proteins from different functional categories into the infected host cell. Secretion of parasite hexokinase and α/β-hydrolase was confirmed by immunofluorescence microscopy. In addition, this method showed specific accumulation of A. locustae hexokinase in host nuclei. Expression of hexokinase, trehalase, and two leucine-rich repeat proteins without any exogenous signal peptide led to their secretion in the yeast Pichia pastoris. In contrast, α/β-hydrolase was not found in the culture medium, though a significant amount of this enzyme accumulated in the yeast membrane fraction. These results suggest that microsporidia possess a broad set of enzymes and regulatory proteins secreted into infected cells to control host metabolic processes and molecular programs. PMID:24705470

  11. Analysis of biosurfactants from industrially viable Pseudomonas strain isolated from crude oil suggests how rhamnolipids congeners affect emulsification property and antimicrobial activity

    PubMed Central

    Das, Palashpriya; Yang, Xin-Ping; Ma, Luyan Z.

    2014-01-01

    Rhamnolipid biosurfactants produced mainly by Pseudomonas sp. had been reported to possess a wide range of potential industrial application. These biosurfactants are produced as monorhamnolipid (MRL) and di-rhamnolipid (DRL) congeners. The present study deals with rhamnolipid biosurfactants produced by three bacterial isolates from crude oil. Biosurfactants produced by one of the strains (named as IMP67) was found to be very efficacious based on its critical micelle concentration value and hydrocarbon emulsification property. Strikingly, antimicrobial, and anti-biofilm potential of this biosurfactant were higher than biosurfactants produced by other two strains. Thin layer chromatography analysis and rhamnose quantification showed that the rhamnolipids of IMP67 had more MRL congeners than biosurfactants of the other two strains. Emulsification and antimicrobial actions were affected by manual change of MRL and DRL congener proportions. Increase of MRL proportion enhanced emulsification index and antimicrobial property to Gram negative bacteria. This result indicated that the ratio of MRL and DRL affected the emulsification potentials of rhamnolipids, and suggested that high emulsification potentials might enhance rhamnolipids to penetrate the cell wall of Gram negative bacteria. In line with this finding, rhamnolipids of IMP67 also reduced the MIC of some antibiotics against bacteria, suggesting their synergistic role with the antibiotics. PMID:25566212

  12. Materials and Activities for Teachers and Children (MATCH). Program Report.

    ERIC Educational Resources Information Center

    Bye, Margaret

    Self contained multi-media kits for grades 1 through 6 involve students directly in the learning process. Emphasis is on non-verbal learning which takes place when youngsters examine real objects and engage in learning activities. Involved in the discovery and inquiry process, students hypothesize, classify, and categorize. In an interdisciplinary…

  13. Digital active material processing platform effort (DAMPER), SBIR phase 2

    NASA Technical Reports Server (NTRS)

    Blackburn, John; Smith, Dennis

    1992-01-01

    Applied Technology Associates, Inc., (ATA) has demonstrated that inertial actuation can be employed effectively in digital, active vibration isolation systems. Inertial actuation involves the use of momentum exchange to produce corrective forces which act directly on the payload being actively isolated. In a typical active vibration isolation system, accelerometers are used to measure the inertial motion of the payload. The signals from the accelerometers are then used to calculate the corrective forces required to counteract, or 'cancel out' the payload motion. Active vibration isolation is common technology, but the use of inertial actuation in such systems is novel, and is the focus of the DAMPER project. A May 1991 report was completed which documented the successful demonstration of inertial actuation, employed in the control of vibration in a single axis. In the 1 degree-of-freedom (1DOF) experiment a set of air bearing rails was used to suspend the payload, simulating a microgravity environment in a single horizontal axis. Digital Signal Processor (DSP) technology was used to calculate in real time, the control law between the accelerometer signals and the inertial actuators. The data obtained from this experiment verified that as much as 20 dB of rejection could be realized by this type of system. A discussion is included of recent tests performed in which vibrations were actively controlled in three axes simultaneously. In the three degree-of-freedom (3DOF) system, the air bearings were designed in such a way that the payload is free to rotate about the azimuth axis, as well as translate in the two horizontal directions. The actuator developed for the DAMPER project has applications beyond payload isolation, including structural damping and source vibration isolation. This report includes a brief discussion of these applications, as well as a commercialization plan for the actuator.

  14. Deepening Sleep by Hypnotic Suggestion

    PubMed Central

    Cordi, Maren J.; Schlarb, Angelika A.; Rasch, Björn

    2014-01-01

    Study Objectives: Slow wave sleep (SWS) plays a critical role in body restoration and promotes brain plasticity; however, it markedly declines across the lifespan. Despite its importance, effective tools to increase SWS are rare. Here we tested whether a hypnotic suggestion to “sleep deeper” extends the amount of SWS. Design: Within-subject, placebo-controlled crossover design. Setting: Sleep laboratory at the University of Zurich, Switzerland. Participants: Seventy healthy females 23.27 ± 3.17 y. Intervention: Participants listened to an auditory text with hypnotic suggestions or a control tape before napping for 90 min while high-density electroencephalography was recorded. Measurements and Results: After participants listened to the hypnotic suggestion to “sleep deeper” subsequent SWS was increased by 81% and time spent awake was reduced by 67% (with the amount of SWS or wake in the control condition set to 100%). Other sleep stages remained unaffected. Additionally, slow wave activity was significantly enhanced after hypnotic suggestions. During the hypnotic tape, parietal theta power increases predicted the hypnosis-induced extension of SWS. Additional experiments confirmed that the beneficial effect of hypnotic suggestions on SWS was specific to the hypnotic suggestion and did not occur in low suggestible participants. Conclusions: Our results demonstrate the effectiveness of hypnotic suggestions to specifically increase the amount and duration of slow wave sleep (SWS) in a midday nap using objective measures of sleep in young, healthy, suggestible females. Hypnotic suggestions might be a successful tool with a lower risk of adverse side effects than pharmacological treatments to extend SWS also in clinical and elderly populations. Citation: Cordi MJ, Schlarb AA, Rasch B. Deepening sleep by hypnotic suggestion. SLEEP 2014;37(6):1143-1152. PMID:24882909

  15. Exploratory research on mutagenic activity of coal-related materials

    SciTech Connect

    Warshawsky, D.; Schoeny, R. S.

    1980-01-01

    The following samples were found to be mutagenic for strains TA1538, TA98 and TA100 Salmonella typhimurium: ETTM-10, ETTM-11, ETTM-15, ETTM-16, and ETTM-17. ETTM-13 was marginally mutagenic for TA1537. ETTM-14 was slightly mutagenic for TA1537, TA1538, and TA98. Mutagenicity by all samples was demonstrated only in the presence of hepatic enzyme extracts (S9) which provided metabolic activation. ETTM-11 was shown to be the most mutagenic sample assayed thus far; specific activity was 2.79 x 10/sup 4/ TA98 revertants/mg sample. Fractionation by serial extractions with increasingly polar organic solvents was done at least 2 x with ETTM-10, ETTM-11, ETTM-15, ETTM-16 and ETTM-17. For some samples highly mutagenic fractions were observed.

  16. Activation of Transient Receptor Potential Ankyrin-1 by Insoluble Particulate Material and Association with Asthma.

    PubMed

    Deering-Rice, Cassandra E; Shapiro, Darien; Romero, Erin G; Stockmann, Chris; Bevans, Tatjana S; Phan, Quang M; Stone, Bryan L; Fassl, Bernhard; Nkoy, Flory; Uchida, Derek A; Ward, Robert M; Veranth, John M; Reilly, Christopher A

    2015-12-01

    Inhaled irritants activate transient receptor potential ankyrin-1 (TRPA1), resulting in cough, bronchoconstriction, and inflammation/edema. TRPA1 is also implicated in the pathogenesis of asthma. Our hypothesis was that particulate materials activate TRPA1 via a mechanism distinct from chemical agonists and that, in a cohort of children with asthma living in a location prone to high levels of air pollution, expression of uniquely sensitive forms of TRPA1 may correlate with reduced asthma control. Variant forms of TRPA1 were constructed by mutating residues in known functional elements and corresponding to single-nucleotide polymorphisms in functional domains. TRPA1 activity was studied in transfected HEK-293 cells using allyl-isothiocynate, a model soluble electrophilic agonist; 3,5-ditert butylphenol, a soluble nonelectrophilic agonist and a component of diesel exhaust particles; and insoluble coal fly ash (CFA) particles. The N-terminal variants R3C and R58T exhibited greater, but not additive, activity with all three agonists. The ankyrin repeat domain-4 single nucleotide polymorphisms E179K and K186N exhibited decreased response to CFA. The predicted N-linked glycosylation site residues N747A and N753A exhibited decreased responses to CFA, which were not attributable to differences in cellular localization. The pore-loop residue R919Q was comparable to wild-type, whereas N954T was inactive to soluble agonists but not CFA. These data identify roles for ankyrin domain-4, cell surface N-linked glycans, and selected pore-loop domain residues in the activation of TRPA1 by insoluble particles. Furthermore, the R3C and R58T polymorphisms correlated with reduced asthma control for some children, which suggest that TRPA1 activity may modulate asthma, particularly among individuals living in locations prone to high levels of air pollution.

  17. Processing, localization and binding activity of zonadhesin suggest a function in sperm adhesion to the zona pellucida during exocytosis of the acrosome.

    PubMed Central

    Bi, Ming; Hickox, John R; Winfrey, Virginia P; Olson, Gary E; Hardy, Daniel M

    2003-01-01

    Zonadhesin is a sperm protein that binds in a species-specific manner to the extracellular matrix ZP (zona pellucida) of the mammalian oocyte. The pig zonadhesin precursor is a 267000-Da mosaic protein with a Type I membrane topology and a large extracellular region comprising meprin/A5 antigen/mu receptor tyrosine phosphatase, mucin and five tandem von Willebrand D (VWD) domains. Multiple mature forms of zonadhesin in the sperm head differ in their avidities for the ZP. To determine the potential functions of zonadhesin forms in gamete adhesion, we characterized the processing, activation and localization of protein in pig spermatozoa. The predominant polypeptides of processed zonadhesin were M(r) 300000 (p300), 105000 (p105) and 45000 (p45). p45 and p105, comprised primarily the D1, D2-D3 domains respectively, and were N-glycosylated. p300 was heavily O-glycosylated, and spanned the meprin/A5 antigen/mu receptor tyrosine phosphatase, mucin and D0 domains. Hydrolysis of the precursor polypeptide occurred in the testis, and N-terminal sequencing of p45 and p105 identified Asp806-Pro and Asp1191-Pro in the D1 and D2 domains respectively as bonds cleaved in the protein's functional maturation. Testicular zonadhesin was extractable with non-ionic detergents, and localized to the developing outer acrosomal membrane of round and elongating spermatids. As spermatozoa transited the epididymis, most of the protein became incorporated into an extraction-resistant fraction, and the proportions of active and of multimeric zonadhesins in the cells increased. Zonadhesin localized to the perimeter of the acrosome in intact ejaculated spermatozoa and to the leading edge of acrosomal matrix overlying cells with disrupted acrosomal membranes. We conclude that the zonadhesin precursor is specifically proteolysed, glycosylated and assembled into particulate structures in the distal parts of the acrosome where it may mediate specific adhesion to the ZP during the initial stages of

  18. Ideas Exchange: Physical Education as a Dynamic Content Area Should Motivate Students to Be Physically Active. What New Ideas Can You Suggest to Kick Off the New School Year and Get Everyone "Moving" in the Right Direction?

    ERIC Educational Resources Information Center

    Chase, Melissa A.; Wright, James; Magnotta, John; Goldberg, Mark; Muller, Barbara; Reitz, Adam; Zavatto, Laura; Christenson, Bob; Winiecki, Tom; Beardsley, Rita; Connors, Shelly; Robelee, Margaret E.; Gosset, Michael; Mavrek, Srecko

    2010-01-01

    Physical education as a dynamic content area should motivate students to be physically active. In this article, readers suggest new ideas to kick off the new school year and get everyone "moving" in the right direction.

  19. Innovative active control of gun barrels using smart materials

    NASA Astrophysics Data System (ADS)

    Mattice, Michael S.; LaVigna, Chris

    1997-06-01

    The accuracy of stabilized, turreted gun systems like the 120mm gun on the M1A2 Abrams tank and the 30mm gun on the Apache helicopter are limited by, among other things, structural flexure of the gun barrel and support structure. An advanced actuation system based on piezoelectric translators and an optical fiber strain sensing system are described in conjunction with a rapid prototyping workstation for the design of distributed parameter control systems to actively minimize the effects of vibrations caused by traversing rough terrain or weapon firing.

  20. Activation analysis of admixtures in certain semiconductive materials

    NASA Technical Reports Server (NTRS)

    Artyukhin, P. I.; Gilbert, E. P.; Pronin, V. A.

    1978-01-01

    The use of extractions and chromatographic operations to separate macrobases, and to divide elements into groups convenient for gamma-spectrometric analysis is discussed. Methods are described for the activation detection of some impurities in silicon, arsenic, thallium, and trichloromethylsilane, on the basis of the extraction properties of bis(2-chlorethyl ether) and dimethylbenzylalkylammonium chloride. A schematic diagram of the extraction separation of elements-admixture is presented showing the aqueous and organic phases. The content percentage of the various elements are given in tables.

  1. Photocatalytic degradation of sunscreen active ingredients mediated by nanostructured materials

    NASA Astrophysics Data System (ADS)

    Soto-Vazquez, Loraine

    Water scarcity and pollution are environmental issues with terrible consequences. In recent years several pharmaceutical and personal care products, such as sunscreen active ingredients, have been detected in different water matrices. Its recalcitrant behavior in the environment has caused controversies and generated countless questions about its safety. During this research, we employed an advanced oxidation process (photocatalysis) to degrade sunscreen active ingredients. For this study, we used a 3x3 system, evaluating three photocatalysts and three different contaminants. From the three catalysts employed, two of them were synthesized. ZnO nanoparticles were obtained using zinc acetate dihydrated as the precursor, and TiO2 nanowires were synthesized from titanium tetrachloride precursor. The third catalyst employed (namely, P25) was obtained commercially. The synthesized photocatalysts were characterized in terms of the morphology, elemental composition, crystalline structure, elemental oxidation states, vibrational modes and surface area, using SEM-EDS, XRD, XPS, Raman spectroscopy and BET measurements, respectively. The photocatalysts were employed during the study of the degradation of p-aminobenzoic acid, phenylbenzimidazole sulfonic acid, and benzophenone-4. In all the cases, at least 50% degradation was achieved. P25 showed degradation efficiencies above 90%, and from the nine systems, 7 of them degraded at least 86%.

  2. Analysis of Porcine Transcriptional Response to Salmonella enterica serovar Choleraesuis suggests novel targets of NFkappaB are activated in the Mesenteric Lymph Node

    PubMed Central

    Wang, Yanfang; Couture, Oliver P; Qu, Long; Uthe, Jolita J; Bearson, Shawn MD; Kuhar, Daniel; Lunney, Joan K; Nettleton, Dan; Dekkers, Jack CM; Tuggle, Christopher K

    2008-01-01

    Background Specific knowledge of the molecular pathways controlling host-pathogen interactions can increase our understanding of immune response biology as well as provide targets for drug development and genetic improvement of disease resistance. Toward this end, we have characterized the porcine transcriptional response to Salmonella enterica serovar Choleraesuis (S. Choleraesuis), a Salmonella serovar that predominately colonizes swine, yet can cause serious infections in human patients. Affymetrix technology was used to screen for differentially expressed genes in pig mesenteric lymph nodes (MLN) responding to infection with S. Choleraesuis at acute (8 hours (h), 24 h and 48 h post-inoculation (pi)) and chronic stages (21 days (d) pi). Results Analysis of variance with false discovery rate control identified 1,853 genes with significant changes in expression level (p-value < 0.01, q-value < 0.26, and fold change (FC) > 2) during infection as compared to un-inoculated control pigs. Down-regulation of translation-related genes at 8 hpi and 24 hpi implied that S. Choleraesuis repressed host protein translation. Genes involved in the Th1, innate immune/inflammation response and apoptosis pathways were induced significantly. However, antigen presentation/dendritic cell (DC) function pathways were not affected significantly during infection. A strong NFκB-dependent response was observed, as 58 known NFκB target genes were induced at 8, 24 and/or 48 hpi. Quantitative-PCR analyses confirmed the microarray data for 21 of 22 genes tested. Based on expression patterns, these target genes can be classified as an "Early" group (induced at either 8 or 24 hpi) and a "Late" group (induced only at 48 hpi). Cytokine activity or chemokine activity were enriched within the Early group genes GO annotations, while the Late group was predominantly composed of signal transduction and cell metabolism annotated genes. Regulatory motif analysis of the human orthologous promoters for

  3. Supercritical adsorption testing of porous silicon, activated carbon, and zeolite materials

    NASA Astrophysics Data System (ADS)

    Harvey, Brendan

    The supercritical adsorption of methane gas on porous silicon, activated carbon, and zeolite materials was studied. An apparatus that utilizes the volumetric adsorption measurement technique was designed and constructed to conduct the experiments. Activated carbon materials consisted of Norit RX3 Extra, Zorflex FM30K woven activated carbon cloth, and Zorflex FM10 knitted activated carbon cloth. Zeolite materials consisted of 3A, 4A, 5A, and 13X zeolites. Porous silicon materials consisted of stain etched and electrochemically etched porous films, and stain etched porous powder. All adsorption tests were conducted at room temperature (approximately 298 K) and pressures up to approximately 5 MPa. Overall, the Norit RX3 Extra granulated activated carbon produced the highest excess adsorption and effective storage capacities. Effective storage and delivery capacities of 109 and 90 stpmlml were obtained at a pressure of 3.5 MPa and a temperature of approximately 298 K.

  4. Characterization of the airborne activity confinement system prefilter material

    SciTech Connect

    Long, T.A.; Monson, P.R.

    1992-05-01

    A general concern with assessing the effects of postulated severe accidents is predicting and preventing the release of radioactive isotopes to the environment at the Savannah River Site (SRS) reactor. Unless the confinement systems are breached in an accident the Airborne Activity Confinement System forces all of the internal air through the filter compartments. Proper modeling of the radioactivity released to the environment requires knowledge of the filtering characteristics of the demisters, the HEPA`s, and the charcoal beds. An investigation of the mass loading characteristics for a range of particle sizes was performed under the direction of Vince Novick of Argonne National Laboratory (ANL) for the Savannah River Technology Center (SRTC) in connection with the restart of the K reactor. Both solid and liquid aerosols were used to challenge sample prefilter and HEPA filters. The results of the ANL investigation are reported in this document.

  5. Characterization of the airborne activity confinement system prefilter material

    SciTech Connect

    Long, T.A.; Monson, P.R.

    1992-05-01

    A general concern with assessing the effects of postulated severe accidents is predicting and preventing the release of radioactive isotopes to the environment at the Savannah River Site (SRS) reactor. Unless the confinement systems are breached in an accident the Airborne Activity Confinement System forces all of the internal air through the filter compartments. Proper modeling of the radioactivity released to the environment requires knowledge of the filtering characteristics of the demisters, the HEPA's, and the charcoal beds. An investigation of the mass loading characteristics for a range of particle sizes was performed under the direction of Vince Novick of Argonne National Laboratory (ANL) for the Savannah River Technology Center (SRTC) in connection with the restart of the K reactor. Both solid and liquid aerosols were used to challenge sample prefilter and HEPA filters. The results of the ANL investigation are reported in this document.

  6. Active nondestructive assay of nuclear materials: principles and applications

    SciTech Connect

    Gozani, Tsahi

    1981-01-01

    The purpose of this book is to present, coherently and comprehensively, the wealth of available but scattered information on the principles and applications of active nondestructive analysis (ANDA). Chapters are devoted to the following: background and overview; interactions of neutrons with matter; interactions of ..gamma..-rays with matter; neutron production and sources; ..gamma..-ray production and sources; effects of neutron and ..gamma..-ray transport in bulk media; signatures of neutron- and photon-induced fissions; neutron and photon detection systems and electronics; representative ANDA systems; and instrument analysis, calibration, and measurement control for ANDA. Each chapter has an introductory section describing the relationship of the topic of that chapter to ANDA. Each chapter ends with a section that summarizes the main results and conclusions of the chapter, and a reference list.

  7. Poly(3-phenylthiophene) derivatives as active materials for electrochemical capacitors

    NASA Astrophysics Data System (ADS)

    Eissa, Mona M.

    Poly(3-(4-methylsulfonylphenyl)thiophenes) (PMSPT), (3-(4-cyanophenyl)-thiophene) (PCNPT), (3-(3,4-difluorophenyl)thiophene) (MPFPT), (3-(3,5difluorophenyl)thiophene) (MMFPT), and (3-(3-fluorophenyl)thiophene) (MFPT) polymers were prepared and electrochemically characterized in various organic electrolytes. The morphologies and electrochemical performance of the films were shown to depend on both the growth and cycling electrolytes. Constant current multicycle tests were performed on single cell devices using the type III capacitor configuration at high voltage (2.8-2.9 V) employing MPFPT, PCNPT, PMSPT and PFPT polymers. Energy and power densities of up to 50 Wh/kg and 5 kW/kg were achieved and excellent stabilities (up to 1200 n-doping/dedoping cycles) were demonstrated. Industrial practicum. The industrial practicum report on "Chemical Vapor Deposition of High Performance Polymeric Thin Films for Advanced Interconnect Applications" determined the copolymerization and characterization of four novel copolymers of Parylene-N by a CVD process at low temperature. These copolymers retain the advantages of the CVD process and also modify the properties of the Parylene homopolymer significantly such as lowering the dielectric constant from 2.65 to ˜2.0, increasing the thermal stability and enhancing the adhesion. Apprenticeship practicum. The study on "Synthesis, Characterization, and Catalytic Activity of The Zeolite Encapsulated Ruthenium hexadeca-fluorophthalocyanine Complexes" determined the catalytic activity of this fluorinated ruthenium phthalocyanine which was encapsulated in zeolite NaX during crystallization. Both the free complex RuFsb{16}Pc and the encapsulated (RuFsb{16}Pc-NaX) were found to be effective catalysts for the oxidation of cyclohexane with high efficiency and stability.

  8. A suggested emergency medicine boot camp curriculum for medical students based on the mapping of Core Entrustable Professional Activities to Emergency Medicine Level 1 milestones

    PubMed Central

    Lamba, Sangeeta; Wilson, Bryan; Natal, Brenda; Nagurka, Roxanne; Anana, Michael; Sule, Harsh

    2016-01-01

    Background An increasing number of students rank Emergency Medicine (EM) as a top specialty choice, requiring medical schools to provide adequate exposure to EM. The Core Entrustable Professional Activities (EPAs) for Entering Residency by the Association of American Medical Colleges combined with the Milestone Project for EM residency training has attempted to standardize the undergraduate and graduate medical education goals. However, it remains unclear as to how the EPAs correlate to the milestones, and who owns the process of ensuring that an entering EM resident has competency at a certain minimum level. Recent trends establishing specialty-specific boot camps prepare students for residency and address the variability of skills of students coming from different medical schools. Objective Our project’s goal was therefore to perform a needs assessment to inform the design of an EM boot camp curriculum. Toward this goal, we 1) mapped the core EPAs for graduating medical students to the EM residency Level 1 milestones in order to identify the possible gaps/needs and 2) conducted a pilot procedure workshop that was designed to address some of the identified gaps/needs in procedural skills. Methods In order to inform the curriculum of an EM boot camp, we used a systematic approach to 1) identify gaps between the EPAs and EM milestones (Level 1) and 2) determine what essential and supplemental competencies/skills an incoming EM resident should ideally possess. We then piloted a 1-day, three-station advanced ABCs procedure workshop based on the identified needs. A pre-workshop test and survey assessed knowledge, preparedness, confidence, and perceived competence. A post-workshop survey evaluated the program, and a posttest combined with psychomotor skills test using three simulation cases assessed students’ skills. Results Students (n=9) reported increased confidence in the following procedures: intubation (1.5–2.1), thoracostomy (1.1–1.9), and central venous

  9. Energy Materials.

    ERIC Educational Resources Information Center

    Iowa State Dept. of Public Instruction, Des Moines.

    These resource materials, developed for use by teachers in the elementary and secondary schools, are designed to provide the teacher with a bibliography, questions and answeres, and suggested classroom activities all relating to the energy problem. The materials are designed to develop a conservation ethic and greater understanding of our energy…

  10. Improvement Characteristics of Bio-active Materials Coated Fabric on Rat Muscular Mitochondria.

    PubMed

    Lee, Donghee; Kim, Young-Won; Kim, Jung-Ha; Yang, Misuk; Bae, Hyemi; Lim, Inja; Bang, Hyoweon; Go, Kyung-Chan; Yang, Gwang-Wung; Rho, Yong-Hwan; Park, Hyo-Suk; Park, Eun-Ho; Ko, Jae-Hong

    2015-05-01

    This study surveys the improvement characteristics in old-aged muscular mitochondria by bio-active materials coated fabric (BMCF). To observe the effects, the fabric (10 and 30%) was worn to old-aged rat then the oxygen consumption efficiency and copy numbers of mitochondria, and mRNA expression of apoptosis- and mitophagy-related genes were verified. By wearing the BMCF, the oxidative respiration significantly increased when using the 30% materials coated fabric. The mitochondrial DNA copy number significantly decreased and subsequently recovered in a dose-dependent manner. The respiratory control ratio to mitochondrial DNA copy number showed a dose-dependent increment. As times passed, Bax, caspase 9, PGC-1α and β-actin increased, and Bcl-2 decreased in a dose-dependent manner. However, the BMCF can be seen to have had no effect on Fas receptor. PINK1 expression did not change considerably and was inclined to decrease in control group, but the expression was down-regulated then subsequently increased with the use of the BMCF in a dose-dependent manner. Caspase 3 increased and subsequently decreased in a dose-dependent manner. These results suggest that the BMCF invigorates mitophagy and improves mitochondrial oxidative respiration in skeletal muscle, and in early stage of apoptosis induced by the BMCF is not related to extrinsic death-receptor mediated but mitochondria-mediated signaling pathway.

  11. Spanish-Hispanic Culture from A to V (Actualidades to Venezuela): 72 Spanish-Language Interdisciplinary Cultural Themes with Suggested Resource Materials and Activities.

    ERIC Educational Resources Information Center

    Moore, Merriam M.

    This guidebook is intended for use by teachers of Spanish (FLES through college level) and by teachers in Spanish bilingual programs. It lists all of the Spanish-speaking countries and 72 Spanish-language cultural themes, such as "Actualidades" (Current Events), "Carreras y espanol comercial" (Careers and Commercial Spanish), "Deportes" (Sports),…

  12. THERMAL IMAGING OF ACTIVE MAGNETIC REGERNERATOR MCE MATERIALS DURING OPERATION

    SciTech Connect

    Shassere, Benjamin; West, David L; Abdelaziz, Omar; Evans III, Boyd Mccutchen

    2012-01-01

    An active magnetic regenerator (AMR) prototype was constructed that incorporates a Gd sheet into the regenerator wall to enable visualization of the system s thermal transients. In this experiment, the thermal conditions inside the AMR are observed under a variety of operating conditions. An infrared (IR) camera is employed to visualize the thermal transients within the AMR. The IR camera is used to visually and quantitatively evaluate the temperature difference and thus giving means to calculate the performance of the system under the various operating conditions. Thermal imaging results are presented for two differing experimental test runs. Real time imaging of the thermal state of the AMR has been conducted while operating the system over a range of conditions. A 1 Tesla twin-coil electromagnet (situated on a C frame base) is used for this experiment such that all components are stationary during testing. A modular, linear reciprocating system has been realized in which the effects of regenerator porosity and utilization factor can be investigated. To evaluate the performance variation in porosity and utilization factor the AMR housing was constructed such that the plate spacing of the Gd sheets may be varied. Each Gd sheet has dimensions of 38 mm wide and 66 mm long with a thickness of 1 mm and the regenerator can hold a maximum of 29 plates with a spacing of 0.25 mm. Quantitative and thermal imaging results are presented for several regenerator configurations.

  13. Active control of acoustic pressure fields using smart material technologies

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Smith, R. C.

    1993-01-01

    An overview describing the use of piezoceramic patches in reducing noise in a structural acoustics setting is presented. The passive and active contributions due to patches which are bonded to an Euler-Bernoulli beam or thin shell are briefly discussed and the results are incorporated into a 2-D structural acoustics model. In this model, an exterior noise source causes structural vibrations which in turn lead to interior noise as a result of nonlinear fluid/structure coupling mechanism. Interior sound pressure levels are reduced via patches bonded to the flexible boundary (a beam in this case) which generate pure bending moments when an out-of-phase voltage is applied. Well-posedness results for the infinite dimensional system are discussed and a Galerkin scheme for approximating the system dynamics is outlined. Control is implemented by using linear quadratic regulator (LQR) optimal control theory to calculate gains for the linearized system and then feeding these gains back into the nonlinear system of interest. The effectiveness of this strategy for this problem is illustrated in an example.

  14. Micro- and Nanostructured Materials for Active Devices and Molecular Electronics

    SciTech Connect

    Martin, Peter M.; Graff, Gordon L.; Gross, Mark E.; Burrows, Paul E.; Bennett, Wendy D.; Mast, Eric S.; Hall, Michael G.; Bonham, Charles C.; Zumhoff, Mac R.; Williford, Rick E.

    2003-10-01

    Traditional single layer barrier coatings are not adequate in preventing degradation of the performance of organic molecular electronic and other active devices. Most advanced devices used in display technology now consist of micro and nanostructured small molecule, polymer and inorganic coatings with thin high reactive group 1A metals. This includes organic electronics such as organic light emitting devices (OLED). The lifetimes of these devices rapidly degrades when they are exposed to atmospheric oxygen and water vapor. Thin film photovoltaics and batteries are also susceptible to degradation by moisture and oxygen. Using in-line coating techniques we apply a composite nanostructured inorganic/polymer thin film barrier that restricts moisture and oxygen permeation to undetectable levels using conventional permeation test equipment. We describe permeation mechanisms for this encapsulation coating and flat panel display and other device applications. Permeation through the multilayer barrier coating is defect and pore limited and can be described by Knudsen diffusion involving a long and tortuous path. Device lifetime is also enhanced by the long lag times required to reach the steady state flux regime. Permeation rates in the range of 10-6 cc,g/m2/d have been achieved and OLED device lifetimes. The structure is robust, yet flexible. The resulting device performance and lifetimes will also be described. The barrier film can be capped with a thin film of transparent conductive oxide yielding an engineered nanostructured device for next generation, rugged, lightweight or flexible displays. This enables, for the first time, thin film encapsulation of emissive organic displays.

  15. Progress Report {number_sign}1 on the materials identification, characterization and evaluation activity: Acquisition of materials data from the Exploratory Studies Facility

    SciTech Connect

    Meike, A., LLNL

    1998-02-01

    This paper reports on the initial work within the Materials Identification, Characterization and Evaluation Sub-activity Integration Activity within the Introduced Materials Task (IMT) (WBS 1.2.3.12.5). The goals of this activity are twofold.: (1) to identify and characterize types and usage of materials that are most likely to be introduced into a potential High Level Radioactive Waste (HLW) repository at Yucca Mountain, Nevada, as a result of its construction and operation and (2) to provide tools for the Integration Activity to evaluate the chemical impact on the repository based on information gathered from sources external and internal to the Introduced Materials Task-by the Literature Survey Sub-activity (Integration Activity, IMT). Based on this information and assessment, the Integration Activity activates relevant activities within the Introduced Materials Task and provides information to other Tasks within the Yucca Mountain Project.

  16. Developing the intervention material to increase physical activity levels of European preschool children: the ToyBox-study.

    PubMed

    Duvinage, K; Ibrügger, S; Kreichauf, S; Wildgruber, A; De Craemer, M; De Decker, E; Androutsos, O; Lateva, M; Iotova, V; Socha, P; Zych, K; Mouratidou, T; Mesana Graffe, M I; Manios, Y; Koletzko, B

    2014-08-01

    Early childhood is an important period for adopting positive health-related behaviours. More than 95% of European preschool children attend kindergartens, making these settings ideal for the implementation of health promotion interventions. The ToyBox-intervention addressed preschool children, their parents/caregivers and teachers. The aim of the intervention was to improve four energy balance-related behaviours (i.e. healthy snacking, water consumption, physical activity and sedentary behaviour) by implementing a kindergarten-based, family-involved intervention in six European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain). The intervention material was developed following the intervention mapping protocol, taking into account local and cultural differences among the intervention countries. The present paper focuses on the development of the physical activity component of the intervention. Parental involvement was addressed by providing parents/caregivers with two newsletters, two tip cards and a poster. Teachers received a handbook with guidance on environmental changes in the classroom, 26 physical education sessions and suggestions for fun, interactive classroom activities aiming at total class participation to increase preschoolers' physical activity levels. The ToyBox-intervention material was distributed according to a standard time frame. Teachers received their material prior to the start of the intervention and parents/caregivers received their material during the intervention when each energy balance-related behaviour was implemented. PMID:25047376

  17. Developing the intervention material to increase physical activity levels of European preschool children: the ToyBox-study.

    PubMed

    Duvinage, K; Ibrügger, S; Kreichauf, S; Wildgruber, A; De Craemer, M; De Decker, E; Androutsos, O; Lateva, M; Iotova, V; Socha, P; Zych, K; Mouratidou, T; Mesana Graffe, M I; Manios, Y; Koletzko, B

    2014-08-01

    Early childhood is an important period for adopting positive health-related behaviours. More than 95% of European preschool children attend kindergartens, making these settings ideal for the implementation of health promotion interventions. The ToyBox-intervention addressed preschool children, their parents/caregivers and teachers. The aim of the intervention was to improve four energy balance-related behaviours (i.e. healthy snacking, water consumption, physical activity and sedentary behaviour) by implementing a kindergarten-based, family-involved intervention in six European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain). The intervention material was developed following the intervention mapping protocol, taking into account local and cultural differences among the intervention countries. The present paper focuses on the development of the physical activity component of the intervention. Parental involvement was addressed by providing parents/caregivers with two newsletters, two tip cards and a poster. Teachers received a handbook with guidance on environmental changes in the classroom, 26 physical education sessions and suggestions for fun, interactive classroom activities aiming at total class participation to increase preschoolers' physical activity levels. The ToyBox-intervention material was distributed according to a standard time frame. Teachers received their material prior to the start of the intervention and parents/caregivers received their material during the intervention when each energy balance-related behaviour was implemented.

  18. Micromechanics and constitutive models for soft active materials with phase evolution

    NASA Astrophysics Data System (ADS)

    Wang, Binglian

    Soft active materials, such as shape memory polymers, liquid crystal elastomers, soft tissues, gels etc., are materials that can deform largely in response to external stimuli. Micromechanics analysis of heterogeneous materials based on finite element method is a typically numerical way to study the thermal-mechanical behaviors of soft active materials with phase evolution. While the constitutive models that can precisely describe the stress and strain fields of materials in the process of phase evolution can not be found in the databases of some commercial finite element analysis (FEA) tools such as ANSYS or Abaqus, even the specific constitutive behavior for each individual phase either the new formed one or the original one has already been well-known. So developing a computationally efficient and general three dimensional (3D) thermal-mechanical constitutive model for soft active materials with phase evolution which can be implemented into FEA is eagerly demanded. This paper first solved this problem theoretically by recording the deformation history of each individual phase in the phase evolution process, and adopted the idea of effectiveness by regarding all the new formed phase as an effective phase with an effective deformation to make this theory computationally efficient. A user material subroutine (UMAT) code based on this theoretical constitutive model has been finished in this work which can be added into the material database in Abaqus or ANSYS and can be easily used for most soft active materials with phase evolution. Model validation also has been done through comparison between micromechanical FEA and experiments on a particular composite material, shape memory elastomeric composite (SMEC) which consisted of an elastomeric matrix and the crystallizable fibre. Results show that the micromechanics and the constitutive models developed in this paper for soft active materials with phase evolution are completely relied on.

  19. Oil-containing waste water treating material consisting of modified active carbon

    SciTech Connect

    Sato, H.; Shigeta, S.; Takenaka, Y.

    1982-03-16

    An oil-containing waste water treating material comprises an active carbon upon whose surface is chemically bonded at least one nitrogenous compound which is an amine or a quaternarized derivative thereof.

  20. "Go Be a Writer": Intra-Activity with Materials, Time and Space in Literacy Learning

    ERIC Educational Resources Information Center

    Kuby, Candace R.; Rucker, Tara Gutshall; Kirchhofer, Jessica M.

    2015-01-01

    This article is based on research in a United States second-grade classroom during a multimodal literacy workshop. Observing students working with tissue paper, foam board, string, pipe cleaners and other materials, we asked how is intra-activity with materials, time and space influencing literacy learning in Room 203? While the research…

  1. Regulation of Synaptic Vesicle Docking by Different Classes of Macromolecules in Active Zone Material

    PubMed Central

    Szule, Joseph A.; Harlow, Mark L.; Jung, Jae Hoon; De-Miguel, Francisco F.; Marshall, Robert M.; McMahan, Uel J.

    2012-01-01

    The docking of synaptic vesicles at active zones on the presynaptic plasma membrane of axon terminals is essential for their fusion with the membrane and exocytosis of their neurotransmitter to mediate synaptic impulse transmission. Dense networks of macromolecules, called active zone material, (AZM) are attached to the presynaptic membrane next to docked vesicles. Electron tomography has shown that some AZM macromolecules are connected to docked vesicles, leading to the suggestion that AZM is somehow involved in the docking process. We used electron tomography on the simply arranged active zones at frog neuromuscular junctions to characterize the connections of AZM to docked synaptic vesicles and to search for the establishment of such connections during vesicle docking. We show that each docked vesicle is connected to 10–15 AZM macromolecules, which fall into four classes based on several criteria including their position relative to the presynaptic membrane. In activated axon terminals fixed during replacement of docked vesicles by previously undocked vesicles, undocked vesicles near vacated docking sites on the presynaptic membrane have connections to the same classes of AZM macromolecules that are connected to docked vesicles in resting terminals. The number of classes and the total number of macromolecules to which the undocked vesicles are connected are inversely proportional to the vesicles’ distance from the presynaptic membrane. We conclude that vesicle movement toward and maintenance at docking sites on the presynaptic membrane are directed by an orderly succession of stable interactions between the vesicles and distinct classes of AZM macromolecules positioned at different distances from the membrane. Establishing the number, arrangement and sequence of association of AZM macromolecules involved in vesicle docking provides an anatomical basis for testing and extending concepts of docking mechanisms provided by biochemistry. PMID:22438915

  2. Quantum dots as active material for quantum cascade lasers: comparison to quantum wells

    NASA Astrophysics Data System (ADS)

    Michael, Stephan; Chow, Weng W.; Schneider, Hans Christian

    2016-03-01

    We review a microscopic laser theory for quantum dots as active material for quantum cascade lasers, in which carrier collisions are treated at the level of quantum kinetic equations. The computed characteristics of such a quantum-dot active material are compared to a state-of-the-art quantum-well quantum cascade laser. We find that the current requirement to achieve a comparable gain-length product is reduced compared to that of the quantum-well quantum cascade laser.

  3. Heterostereocomplexation between biodegradable and optically active polyesters as a versatile preparation method for biodegradable materials.

    PubMed

    Tsuji, Hideto; Yamamoto, Satomi; Okumura, Ayaka; Sugiura, Yu

    2010-01-11

    The thermal properties and crystallization of biodegradable and optically active poly[(S)-2-hydroxybutyrate] [P(S-2HB)], poly(l-lactide) (PLLA), poly(d-lactide) (PDLA) and their blends were investigated. The results of differential scanning calorimetry, wide-angle X-ray scattering (WAXS), and polarized optical microscopy first indicated heterostereocomplexation between biodegradable and optically active polyesters having different chemical structures and opposite configurations, that is, P(S-2HB) and PDLA. The melting temperature of the heterostereocomplex was higher than those of pure polymers. Such cocrystallization was not observed for P(S-2HB)/PLLA blends having identical configurations. The WAXS profile of P(S-2HB)/PDLA heterostereocomplex was very similar to those of the PLLA/PDLA and P(S-2HB)/P(R-2HB) homostereocomplexes and each crystalline diffraction peak of the heterostereocomplex was located between those of the homostereocomplexes. The present study strongly suggests that heterostereocomplexation will provide a novel versatile method for preparing biodegradable polyester materials with a wide range of physical properties and biodegradability.

  4. Rattling Nucleons: New Developments in Active Interrogation of Special Nuclear Material

    SciTech Connect

    Robert C. Runkle; David L. Chichester; Scott J. Thompson

    2012-01-01

    Active interrogation is a vigorous area of research and development due to its promise of offering detection and characterization capabilities of special nuclear material in environments where passive detection fails. The primary value added by active methods is the capability to penetrate shielding - special nuclear material itself, incidental materials, or intentional shielding - and advocates hope that active interrogation will provide a solution to the problem of detecting shielded uranium, which is at present the greatest obstacle to interdiction efforts. The technique also provides a unique benefit for quantifying nuclear material in high background-radiation environments, an area important for nuclear material safeguards and material accountancy. Progress has been made in the field of active interrogation on several fronts, most notably in the arenas of source development, systems integration, and the integration and exploitation of multiple fission and non-fission signatures. But penetration of interrogating radiation often comes at a cost, not only in terms of finance and dose but also in terms of induced backgrounds, system complexity, and extended measurement times (including set up and acquisition). These costs make the calculus for deciding to implement active interrogation more subtle than may be apparent. The purpose of this review is thus to examine existing interrogation methods, compare and contrast their attributes and limitations, and identify missions where active interrogation may hold the most promise.

  5. Efficiency of biological activator formulated material (BAFM) for volatile organic compounds removal--preliminary batch culture tests with activated sludge.

    PubMed

    Corre, Charline; Couriol, Catherine; Amrane, Abdeltif; Dumont, Eric; Andrès, Yves; Le Cloirec, Pierre

    2012-01-01

    During biological degradation, such as biofiltration of air loaded with volatile organic compounds, the pollutant is passed through a bed packed with a solid medium acting as a biofilm support. To improve microorganism nutritional equilibrium and hence to enhance the purification capacities, a Biological Activator Formulated Material (BAFM) was developed, which is a mixture of solid nutrients dissolving slowly in a liquid phase. This solid was previously validated on mineral pollutants: ammonia and hydrogen sulphide. To evaluate the efficiency of such a material for biodegradation of some organic compounds, a simple experiment using an activated sludge batch reactor was carried out. The pollutants (sodium benzoate, phenol, p-nitrophenol and 2-4-dichlorophenol) were in the concentration range 100 to 1200 mg L(-1). The positive impact of the formulated material was shown. The improvement of the degradation rates was in the range 10-30%. This was the consequence of the low dissolution of the nutrients incorporated during material formulation, followed by their consumption by the biomass, as shown for urea used as a nitrogen source. Owing to its twofold interest (mechanical resistance and nutritional supplementation), the Biological Activator Formulated Material seems to be a promising material. Its addition to organic or inorganic supports should be investigated to confirm its relevance for implementation in biofilters. PMID:22988627

  6. Electrode-active material for electrochemical batteries and method of preparation

    DOEpatents

    Varma, Ravi

    1987-01-01

    A battery electrode material comprising a non-stoichiometric electrode-active material which forms a redox pair with the battery electrolyte, an electrically conductive polymer present in the range of from about 2% by weight to about 5% by weight of the electrode-active material, and a binder. The conductive polymer provides improved proton or ion conductivity and is a ligand resulting in metal ion or negative ion vacancies of less than about 0.1 atom percent. Specific electrodes of nickel and lead are disclosed.

  7. Electrode-active material for electrochemical batteries and method of preparation

    DOEpatents

    Varma, R.

    1983-11-07

    A battery electrode material comprises a non-stoichiometric electrode-active material which forms a redox pair with the battery electrolyte, an electrically conductive polymer present in the range of from about 2% by weight to about 5% by weight of the electrode-active material, and a binder. The conductive polymer provides improved proton or ion conductivity and is a ligand resulting in metal ion or negative ion vacancies of less than about 0.1 atom percent. Specific electrodes of nickel and lead are disclosed.

  8. Determination of contamination in rare earth materials by promptgamma activation analysis (PGAA)

    SciTech Connect

    Perry, D.L.; English, G.A.; Firestone, R.B.; Molnar, G.L.; Revay,Zs.

    2004-11-09

    Prompt gamma activation analysis (PGAA) has been used to detect and quantify impurities in the analyses of rare earth (RE) oxides. The analytical results are discussed with respect to the importance of having a thorough identification and understanding of contaminant elements in these compounds regarding the function of the materials in their various applications. Also, the importance of using PGAA to analyze materials in support of other physico-chemical studies of the materials is discussed, including the study of extremely low concentrations of ions such as the rare earth ions themselves in bulk material matrices.

  9. A new alkali-activated steel slag-based cementitious material for photocatalytic degradation of organic pollutant from waste water.

    PubMed

    Zhang, Yao Jun; Liu, Li Cai; Xu, Yong; Wang, Ya Chao; Xu, De Long

    2012-03-30

    A new type of Ni,Ca-cementitious material was firstly synthesized via a two-step reaction of alkali-activated steel slag polymerization and ion exchange. The XRF results showed that almost all the Na(+) ions in the matrix of Na,Ca-cementitious material were replaced by Ni(2+) ions at room temperature. The new hydrated products of metahalloysite (Si(2)Al(2)O(5)(OH)(4)) and calcium silicate hydrate (CSH) were formed in the Na,Ca-cementitious material. The diffuse reflectance UV-vis near infrared ray spectrum was blue-shifted due to the strong interaction between Ni(2+) and negative charge of [AlO(4)](5-) tetrahedron in the framework of cementitious material. The Ni,Ca-cementitious material was used as a catalyst for the photocatalytic degradation of methylene blue dye and showed a degradation rate of 94.39% under UV irradiation. The high photocatalytic degradation activity was suggested to be the synergistic effect of the cementitious matrix, Ni(2+) ions and the iron oxides of wustite (FeO) and calcium iron oxide (Ca(2)Fe(2)O(5)) from the steel slag. A probable mechanism of photocatalytic oxidative degradation was proposed.

  10. Status of R&D activities on materials for fusion power reactors

    NASA Astrophysics Data System (ADS)

    Baluc, N.; Abe, K.; Boutard, J. L.; Chernov, V. M.; Diegele, E.; Jitsukawa, S.; Kimura, A.; Klueh, R. L.; Kohyama, A.; Kurtz, R. J.; Lässer, R.; Matsui, H.; Möslang, A.; Muroga, T.; Odette, G. R.; Tran, M. Q.; van der Schaaf, B.; Wu, Y.; Yu, J.; Zinkle, S. J.

    2007-10-01

    Current R&D activities on materials for fusion power reactors are mainly focused on plasma facing, structural and tritium breeding materials for plasma facing (first wall, divertor) and breeding blanket components. Most of these activities are being performed in Europe, Japan, the People's Republic of China, Russia and the USA. They relate to the development of new high temperature, radiation resistant materials, the development of coatings that will act as erosion, corrosion, permeation and/or electrical/MHD barriers, characterization of candidate materials in terms of mechanical and physical properties, assessment of irradiation effects, compatibility experiments, development of reliable joints, and development and/or validation of design rules. Priorities defined worldwide in the field of materials for fusion power reactors are summarized, as well as the main achievements obtained during the last few years and the near-term perspectives in the different investigation areas.

  11. The dissolution mechanism of cathodic active materials of spent Zn-Mn batteries in HCl.

    PubMed

    Li, Yunqing; Xi, Guoxi

    2005-12-01

    The cathodic active materials of spent Zn-Mn batteries are complicated. The majority materials that they contain are Mn(OH)(2), Mn(2)O(4), lambda-Mn(2)O(2), ZnMn(2)O(4), Zn(NH(3))(2)Cl(2), [Zn(OH)(2)](4).ZnCl(2), etc. Dissolving these kinds of materials is important to the environmental pollution control and materials recycle. In present paper we investigated the dissolution mechanism of the cathodic active materials in HCl by testing the factors that can influence the dissolution procedure, including temperature, time, and the concentration of HCl and H(2)O(2). Our results showed that both neutralization and oxidation-reduction reactions occurred in the dissolution process, and that H(2)O(2) had a great effect on the dissolution efficiency.

  12. Active binary R Arae revisited: Bringing the secondary component to light and physical modelling of the circumstellar material

    NASA Astrophysics Data System (ADS)

    Bakış, H.; Bakış, V.; Eker, Z.; Demircan, O.

    2016-05-01

    The spectral lines of the secondary component of the active binary system R Ara were uncovered for the first time, which allowed directly to determine the parameters of the spectroscopic orbit. The mass ratio of the system is updated to a new observational value of M2/M1 = 0.305 ± 0.005 which is ˜20 per cent smaller than the literature value (M2/M1 = 0.39). Modelling the reconstructed component spectra yielded the equatorial rotational velocities of the components as vrot1 = 202 km s-1 and vrot2 = 73 km s-1 indicating a very fast rotation (˜5 times faster than the synchronous rotation velocity) for the primary and synchronous rotation for the secondary component. The circumstellar material in the system was investigated using the Hipparcossatellite data and the high-resolution (R ˜ 41 000) spectral data. According to our model, there is always material transferring from the secondary component on to the primary causing a hot region on its surface. The structural difference between the spectra taken at the same orbital phase but at different epochs proved that the density and the velocity of the transferring material are variable. There are three main trends in the light curve and spectral line variations suggesting the activity cycles for the system, namely quiescent, moderate and, active cycles. It was estimated that the circumstellar material around could be extended to large distances up to 40 R⊙ from the system.

  13. IFMIF - International Fusion Materials Irradiation Facility Conceptual Design Activity/Interim Report

    SciTech Connect

    Rennich, M.J.

    1995-12-01

    Environmental acceptability, safety, and economic viability win ultimately be the keys to the widespread introduction of fusion power. This will entail the development of radiation- resistant and low- activation materials. These low-activation materials must also survive exposure to damage from neutrons having an energy spectrum peaked near 14 MeV with annual radiation doses in the range of 20 displacements per atom (dpa). Testing of candidate materials, therefore, requires a high-flux source of high energy neutrons. The problem is that there is currently no high-flux source of neutrons in the energy range above a few MeV. The goal, is therefore, to provide an irradiation facility for use by fusion material scientists in the search for low-activation and damage-resistant materials. An accellerator-based neutron source has been established through a number of international studies and workshops` as an essential step for materials development and testing. The mission of the International Fusion Materials Irradiation Facility (IFMIF) is to provide an accelerator-based, deuterium-lithium (D-Li) neutron source to produce high energy neutrons at sufficient intensity and irradiation volume to test samples of candidate materials up to about a full lifetime of anticipated use in fusion energy reactors. would also provide calibration and validation of data from fission reactor and other accelerator-based irradiation tests. It would generate material- specific activation and radiological properties data, and support the analysis of materials for use in safety, maintenance, recycling, decommissioning, and waste disposal systems.

  14. Performance of Nonmigratory Iron Chelating Active Packaging Materials in Viscous Model Food Systems.

    PubMed

    Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2015-09-01

    Many packaged food products undergo quality deterioration due to iron promoted oxidative reactions. Recently, we have developed a nonmigratory iron chelating active packaging material that represents a novel approach to inhibit oxidation of foods while addressing consumer demands for "cleanˮ labels. A challenge to the field of nonmigratory active packaging is ensuring that surface-immobilized active agents retain activity in a true food system despite diffusional limitations. Yet, the relationship between food viscosity and nonmigratory active packaging activity retention has never been characterized. The objective of this study was to investigate the influence of food viscosity on iron chelation by a nonmigratory iron chelating active packaging material. Methyl cellulose was added to aqueous buffered iron solutions to yield model systems with viscosities ranging from ∼1 to ∼10(5)  mPa·s, representing viscosities ranging from beverage to mayonnaise. Iron chelation was quantified by material-bound iron content using colorimetry and inductively coupled plasma-optical emission spectrometry (ICP-OES).  Maximum iron chelation was reached in solutions up to viscosity ∼10(2)  mPa·s. In more viscous solutions (up to ∼10(4)  mPa·s), there was a significant decrease in iron chelating capacity (P < 0.05). However, materials still retained at least 76% iron chelating capacity. Additionally, the influence of different food hydrocolloids on the performance of nonmigratory iron chelating active packaging was characterized. Methyl cellulose and carrageenan did not compete with the material for specific iron chelation (P > 0.05). Materials retained 32% to 45% chelating capacity when in contact with competitively chelating hydrocolloids guar gum, locust bean gum, and xanthan gum. This work demonstrates the potential application of nonmigratory iron chelating active packaging in liquid and semi-liquid foods to allow for the removal of synthetic chelators, while

  15. Performance of Nonmigratory Iron Chelating Active Packaging Materials in Viscous Model Food Systems.

    PubMed

    Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2015-09-01

    Many packaged food products undergo quality deterioration due to iron promoted oxidative reactions. Recently, we have developed a nonmigratory iron chelating active packaging material that represents a novel approach to inhibit oxidation of foods while addressing consumer demands for "cleanˮ labels. A challenge to the field of nonmigratory active packaging is ensuring that surface-immobilized active agents retain activity in a true food system despite diffusional limitations. Yet, the relationship between food viscosity and nonmigratory active packaging activity retention has never been characterized. The objective of this study was to investigate the influence of food viscosity on iron chelation by a nonmigratory iron chelating active packaging material. Methyl cellulose was added to aqueous buffered iron solutions to yield model systems with viscosities ranging from ∼1 to ∼10(5)  mPa·s, representing viscosities ranging from beverage to mayonnaise. Iron chelation was quantified by material-bound iron content using colorimetry and inductively coupled plasma-optical emission spectrometry (ICP-OES).  Maximum iron chelation was reached in solutions up to viscosity ∼10(2)  mPa·s. In more viscous solutions (up to ∼10(4)  mPa·s), there was a significant decrease in iron chelating capacity (P < 0.05). However, materials still retained at least 76% iron chelating capacity. Additionally, the influence of different food hydrocolloids on the performance of nonmigratory iron chelating active packaging was characterized. Methyl cellulose and carrageenan did not compete with the material for specific iron chelation (P > 0.05). Materials retained 32% to 45% chelating capacity when in contact with competitively chelating hydrocolloids guar gum, locust bean gum, and xanthan gum. This work demonstrates the potential application of nonmigratory iron chelating active packaging in liquid and semi-liquid foods to allow for the removal of synthetic chelators, while

  16. How Do Distance Learners Use Activities in Self-Instructional Materials?

    ERIC Educational Resources Information Center

    Mishra, Sanjaya; Gaba, Ashok Kumar

    2001-01-01

    Presents results of a study on the use of learning activities in self-instructional materials by distance learners of the Indira Gandhi National Open University (IGNOU). It shows that learners make use of the activities extensively as they have positive perceptions about benefits of Self-Assessment Questions and Terminal Questions given in the…

  17. Real space mapping of ionic diffusion and electrochemical activity in energy storage and conversion materials

    SciTech Connect

    Kalinin, Sergei V; Balke, Nina; Kumar, Amit; Dudney, Nancy J; Jesse, Stephen

    2014-05-06

    A method and system for probing mobile ion diffusivity and electrochemical reactivity on a nanometer length scale of a free electrochemically active surface includes a control module that biases the surface of the material. An electrical excitation signal is applied to the material and induces the movement of mobile ions. An SPM probe in contact with the surface of the material detects the displacement of mobile ions at the surface of the material. A detector measures an electromechanical strain response at the surface of the material based on the movement and reactions of the mobile ions. The use of an SPM tip to detect local deformations allows highly reproducible measurements in an ambient environment without visible changes in surface structure. The measurements illustrate effective spatial resolution comparable with defect spacing and well below characteristic grain sizes of the material.

  18. Enhanced Immunostimulating Activity of Lactobacilli-Mimicking Materials by Controlling Size.

    PubMed

    Nagahama, Koji; Kumano, Takayuki; Nakagawa, Yuichi; Oyama, Naho; Tsuji, Hirokazu; Moriyama, Kaoru; Shida, Kan; Nomoto, Koji; Chiba, Katsuyoshi; Koumoto, Kazuya; Matsui, Jun

    2015-08-19

    The design and synthesis of materials capable of activating the immune system in a safe manner is of great interest in immunology and related fields. Lactobacilli activate the innate immune system of a host when acting as probiotics. Here, we constructed lactobacilli-mimicking materials in which polysaccharide-peptidoglycan complexes (PS-PGs) derived from lactobacilli were covalently conjugated to the surfaces of polymeric microparticles with a wide variety of sizes, ranging from 200 nm to 3 μm. The artificial lactobacilli successfully stimulated macrophages without cytotoxicity. Importantly, we found that the size of artificial lactobacilli strongly influenced their immunostimulating activities, and that artificial lactobacilli of 1 μm exhibited 10-fold higher activity than natural lactobacilli. One major advantage of the artificial lactobacilli is facile control of size, which cannot be changed in natural lactobacilli. These findings provide new insights into the design of materials for immunology as well as the molecular biology of lactobacillus.

  19. Material Activation Benchmark Experiments at the NuMI Hadron Absorber Hall in Fermilab

    SciTech Connect

    Matsumura, H.; Matsuda, N.; Kasugai, Y.; Toyoda, A.; Yashima, H.; Sekimoto, S.; Iwase, H.; Oishi, K.; Sakamoto, Y.; Nakashima, H.; Leveling, A.; Boehnlein, D.; Lauten, G.; Mokhov, N.; Vaziri, K.

    2014-06-15

    In our previous study, double and mirror symmetric activation peaks found for Al and Au arranged spatially on the back of the Hadron absorber of the NuMI beamline in Fermilab were considerably higher than those expected purely from muon-induced reactions. From material activation bench-mark experiments, we conclude that this activation is due to hadrons with energy greater than 3 GeV that had passed downstream through small gaps in the hadron absorber.

  20. Loading and utilization of active material in nickel composite electrodes: optimization

    SciTech Connect

    Lee, W.W.; Ferrando, W.A.; Sutula, R.A.

    1984-12-01

    As an attempt to reduce nickel battery weight, the nickel composite electrode, has been under development. Investigations were undertaken to determine the optimum conditions for loading and utilizing nickel hydroxide active material in nickel composite electrodes. The main emphasis was placed on the improvement of both loading efficiency by electrochemical impregnation and utilization efficiency of the Ni(OH)2 active material. The efficiencies were examined as functions of such electrochemical conditions as current density, nickel concentration, pH, temperature of the impregnating bath, the continuity of current flow and manner of adding Co(OH)S additive. Also studied was the loading efficiency of chemical impregnation (polarization method) and the suspension method which enables a direct loading of externally prepared active material into the composite body. The most important factor for a quick utilization of the active material was found to be the additive distribution. A model of the additive distribution in the active material is proposed to account for different patterns of utilization exhibited by the electrodes.

  1. Estimated neutron-activation data for TFTR. Part II. Biological dose rate from sample-materials activation

    SciTech Connect

    Ku, L.; Kolibal, J.G.

    1982-06-01

    The neutron induced material activation dose rate data are summarized for the TFTR operation. This report marks the completion of the second phase of the systematic study of the activation problem on the TFTR. The estimations of the neutron induced activation dose rates were made for spherical and slab objects, based on a point kernel method, for a wide range of materials. The dose rates as a function of cooling time for standard samples are presented for a number of typical neutron spectrum expected during TFTR DD and DT operations. The factors which account for the variations of the pulsing history, the characteristic size of the object and the distance of observation relative to the standard samples are also presented.

  2. Use of silicon carbide sludge to form porous alkali-activated materials for insulating application

    NASA Astrophysics Data System (ADS)

    Prud'homme, E.; Joussein, E.; Rossignol, S.

    2015-07-01

    One of the objectives in the field of alkali-activated materials is the development of materials having greater thermal performances than conventional construction materials such as aerated concrete. The aim of this paper is to present the possibility to obtain controlled porosity and controlled thermal properties with geopolymer materials including a waste like silicon carbide sludge. The porosity is created by the reaction of free silicon contains in silicon carbide sludge leading to the formation of hydrogen. Two possible ways are investigated to control the porosity: modification of mixture formulation and additives introduction. The first way is the most promising and allowed the formation of materials presenting the same density but various porosities, which shows that the material is adaptable to the application. The insulation properties are logically linked to the porosity and density of materials. A lower value of thermal conductivity of 0.075 W.m-1.K-1 can be reached for a material with a low density of 0.27 g.cm-3. These characteristics are really good for a mineral-based material which always displays non-negligible resistance to manipulation.

  3. Electrode including porous particles with embedded active material for use in a secondary electrochemical cell

    DOEpatents

    Vissers, Donald R.; Nelson, Paul A.; Kaun, Thomas D.; Tomczuk, Zygmunt

    1978-04-25

    Particles of carbonaceous matrices containing embedded electrode active material are prepared for vibratory loading within a porous electrically conductive substrate. In preparing the particles, active materials such as metal chalcogenides, solid alloys of alkali or alkaline earth metals along with other metals and their oxides in powdered or particulate form are blended with a thermosetting resin and particles of a volatile to form a paste mixture. The paste is heated to a temperature at which the volatile transforms into vapor to impart porosity at about the same time as the resin begins to cure into a rigid, solid structure. The solid structure is then comminuted into porous, carbonaceous particles with the embedded active material.

  4. Method of preparing porous, active material for use in electrodes of secondary electrochemical cells

    DOEpatents

    Vissers, Donald R.; Nelson, Paul A.; Kaun, Thomas D.; Tomczuk, Zygmunt

    1977-01-01

    Particles of carbonaceous matrices containing embedded electrode active material are prepared for vibratory loading within a porous electrically conductive substrate. In preparing the particles, active materials such as metal chalcogenides, solid alloys of alkali or alkaline earth metals along with other metals and their oxides in powdered or particulate form are blended with a thermosetting resin and particles of a volatile to form a paste mixture. The paste is heated to a temperature at which the volatile transforms into vapor to impart porosity at about the same time as the resin begins to cure into a rigid, solid structure.The solid structure is then comminuted into porous, carbonaceous particles with the embedded active material.

  5. Suggested Minimum Cataloging Standards for Arizona.

    ERIC Educational Resources Information Center

    Scott, Sharon

    1979-01-01

    Notes problems with cataloging library materials in the small and medium sized public library and suggests interpretations of the Anglo-American cataloging rules, with recommendations for their adaptation to smaller libraries. (CWM)

  6. KCP Activities Supporting the W76LEP Stress Cushions and LK3626 RTV Replacement Material Development

    SciTech Connect

    J. W. Schneider

    2009-10-01

    The S-5370 RTV blown foam previously produced by Dow Corning is no longer commercially available. The S-5370 material has been used on all of Los Alamos National Laboratory (LANL) programs to manufacture Stress Cushions up through the W88. The Kansas City Plant (KCP) did not have a sufficient supply of S-5370 material to cover the schedule requirements for the Program. This report provides information on the numerous activities conducted at KCP involving the development of the Program Stress Cushion and replacement RTV material.

  7. Activity concentration of natural radioactive nuclides in nonmetallic industrial raw materials in Japan.

    PubMed

    Iwaoka, Kazuki; Tabe, Hiroyuki; Yonehara, Hidenori

    2014-11-01

    Natural materials such as rock, ore, and clay, containing natural radioactive nuclides are widely used as industrial raw materials in Japan. If these are high concentrations, the workers who handle the material can be unknowingly exposed to radiation at a high level. In this study, about 80 nonmetallic natural materials frequently used as industrial raw materials in Japan were comprehensively collected from several industrial companies, and the activity concentrations of (238)U series, (232)Th series and (40)K in the materials was determined by ICP-MS (inductively-coupled plasma mass spectrometer) and gamma ray spectrum analyses. Effective doses to workers handling them were estimated by using methods for dose estimation given in the RP 122. We found the activity concentrations to be lower than the critical values defined by regulatory requirements as described in the IAEA Safety Guide. The maximum estimated effective dose to workers handling these materials was 0.16 mSv y(-1), which was lower than the reference level (1-20 mSv y(-1)) for existing situation given in the ICRP Publ.103.

  8. Determination of elements in National Bureau of Standards' geological Standard Reference Materials by neutron activation analysis

    SciTech Connect

    Graham, C.C.; Glascock, M.D.; Carni, J.J.; Vogt, J.R.; Spalding, T.G.

    1982-08-01

    Instrumental neutron activation analysis (INAA) and prompt gamma neutron activation analysis (PGNAA) have been used to determine elemental concentrations in two recently issued National Bureau of Standards (NBS) Standard Reference Materials (SRM's). The results obtained are in good agreement with the certified and information values reported by NBS for those elements in each material for which comparisons are available. Average concentrations of 35 elements in SRM 278 obsidian rock and 32 elements in SRM 688 basalt rock are reported for comparison with results that may be obtained by other laboratories.

  9. Graphical computational method for active materials in simulation of optical electromagnetics

    NASA Astrophysics Data System (ADS)

    Potasek, M.; Parilov, E.; Beeson, K.

    2014-03-01

    Traditional numerical analyses of laser beam transmission through "active" nonlinear materials have involved many assumptions that narrow their general applicability. As more complex optical phenomena are widely employed in research and industry, it is necessary to expand the use of numerical simulation methods. Historically, laser-matter interactions have involved calculations of "classical" wave propagation by Maxwell's equations and photon absorption through rate equations using numerous approximations. We describe a novel numerical modeling framework that adapts itself for simulation of different types of active materials provided by a simple graphical input. Our framework combines classical electric field propagation with "active" photon absorption kinetics using computational active photonic building blocks (APBB). It allows investigating a plane electromagnetic wave propagating through generic organic or inorganic photoactive materials; while, "active" photo-transitions are implemented using the APBB algorithm on the user interface. To date we have used the method in multiphoton absorbers, upconversion, semiconductor quantum dots, rare earth ions, organic chromophores, singlet oxygen formation, energy transfer, and optically-induced chemical reactions. We will demonstrate the method with applications of amplification in rare-earth ions and multiple two-photon absorbers materials in tandem.

  10. Evaluation of Light-Activated Provisional Resin Materials for Periodontal Soft Tissue Management

    PubMed Central

    Jun, Soo-Kyung; Lee, Hae-Hyoung

    2016-01-01

    The purpose of this study was to determine mechanical properties using a compressive test with cylinder specimen (h = 6 mm and ϕ = 4 mm) as well as cytotoxicity using elutes from disk specimen (ϕ = 10 mm and h = 2 mm) against human gingival fibroblasts and oral keratinocytes with light-activated provisional resin materials (Revotek LC and Luxatemp Solar) compared to chemically activated counterpart (Snap, Trim II, and Jet). Significantly increased compressive strength (210~280 MPa) was detected in light-activated products compared to chemically activated ones (20~65 MPa, P < 0.05) and similar compressive modulus was detected in both types (0.8~1.5 and 0.5~1.3 GPa). Simultaneously, the light-activated products showed less adverse effects on the periodontal soft tissue cells in any polymerization stage compared to the chemically activated products. Particularly, chemically activated products had significantly greater adverse effects during the “polymerizing” phase compared to those that were “already set” (P < 0.05), as shown in confocal microscopic images of live and dead cells. In conclusion, light-activated provisional resin materials have better mechanical properties as well as biocompatibility against two tested types of oral cells compared to the chemically activated counterpart, which are considered as more beneficial choice for periodontal soft tissue management. PMID:27672651

  11. Evaluation of Light-Activated Provisional Resin Materials for Periodontal Soft Tissue Management

    PubMed Central

    Jun, Soo-Kyung; Lee, Hae-Hyoung

    2016-01-01

    The purpose of this study was to determine mechanical properties using a compressive test with cylinder specimen (h = 6 mm and ϕ = 4 mm) as well as cytotoxicity using elutes from disk specimen (ϕ = 10 mm and h = 2 mm) against human gingival fibroblasts and oral keratinocytes with light-activated provisional resin materials (Revotek LC and Luxatemp Solar) compared to chemically activated counterpart (Snap, Trim II, and Jet). Significantly increased compressive strength (210~280 MPa) was detected in light-activated products compared to chemically activated ones (20~65 MPa, P < 0.05) and similar compressive modulus was detected in both types (0.8~1.5 and 0.5~1.3 GPa). Simultaneously, the light-activated products showed less adverse effects on the periodontal soft tissue cells in any polymerization stage compared to the chemically activated products. Particularly, chemically activated products had significantly greater adverse effects during the “polymerizing” phase compared to those that were “already set” (P < 0.05), as shown in confocal microscopic images of live and dead cells. In conclusion, light-activated provisional resin materials have better mechanical properties as well as biocompatibility against two tested types of oral cells compared to the chemically activated counterpart, which are considered as more beneficial choice for periodontal soft tissue management.

  12. Trace element analysis of K, U and Th in high purity materials by neutron activation analysis

    SciTech Connect

    Pillalamarri, Ila

    2005-09-08

    The concept and usage of 'high purity' are explained. Trace element analysis of K, U and Th by neutron activation analysis is described, the radio-isotopes and their corresponding gamma-rays used to identify the elements are listed. The interfering elements are described. The advantages and disadvantages of using neutron activation analysis are discussed. Some examples of trace impurity determinations in high purity materials are provided.

  13. Comparison of dielectric materials for the activation of a macro-scale hinge configuration

    NASA Astrophysics Data System (ADS)

    Jordi, C.; Schmidt, A.; Kovacs, G.; Ermanni, Paolo

    2011-04-01

    While much of the research on dielectric elastomer actuators used to concentrate on VHB 4910 as dielectric material, lately many new, specifically developed materials have come into focus. The acrylic VHB has been thoroughly characterized in a macro-scale agonist-antagonist configuration on an active hinge. This was carried out with the aim of using it on an airship, which was activated, undulating body and a fin and thus propelled in a fish-like manner. The concept was proved in flight, but still lifetime and viscosity of the actuators and the time-costing fabrication due to the necessary large pre-stretches of the dielectric membrane caused severe inconveniences. In order to evaluate the usability of other materials for this specific purpose, two other materials, a corrugated silicone with silver electrodes (by PolyPower) and an acrylic with interpenetrating network (IPN) developed by Pei et al. were characterized under similar conditions. The influence of the material on performance and design of the actuators and the conclusions for the use of the materials on the airship (and on applications with similar performance requirements) are presented.

  14. Capacitance improvement of supercapacitor active material based on activated carbon fiber working with a Li-ion containing electrolyte

    NASA Astrophysics Data System (ADS)

    Takamura, Tsutomu; Sato, Youh; Sato, Yuichi

    In an attempt to provide a favorable active material of Li + supercapacitor for HEV use, we modified the surface of an activated carbon fiber felt by coating with some transition metal oxides after mild-oxidation treatment. Major source of enhancing capacitance is attributed to be due to the nano-ionics mechanism proposed by Maier and coworkers. Cyclic voltammetry and constant current charge-discharge performance were examined for the surface modified samples in view of power capability. The oxides of Ag, Cu, Pd, and Sn were found effective to enhance the capacitance and high rate charge/discharge performance. The cycleability test was performed as well.

  15. Active Optical Metasurfaces Based on Defect-Engineered Phase-Transition Materials.

    PubMed

    Rensberg, Jura; Zhang, Shuyan; Zhou, You; McLeod, Alexander S; Schwarz, Christian; Goldflam, Michael; Liu, Mengkun; Kerbusch, Jochen; Nawrodt, Ronny; Ramanathan, Shriram; Basov, D N; Capasso, Federico; Ronning, Carsten; Kats, Mikhail A

    2016-02-10

    Active, widely tunable optical materials have enabled rapid advances in photonics and optoelectronics, especially in the emerging field of meta-devices. Here, we demonstrate that spatially selective defect engineering on the nanometer scale can transform phase-transition materials into optical metasurfaces. Using ion irradiation through nanometer-scale masks, we selectively defect-engineered the insulator-metal transition of vanadium dioxide, a prototypical correlated phase-transition material whose optical properties change dramatically depending on its state. Using this robust technique, we demonstrated several optical metasurfaces, including tunable absorbers with artificially induced phase coexistence and tunable polarizers based on thermally triggered dichroism. Spatially selective nanoscale defect engineering represents a new paradigm for active photonic structures and devices.

  16. Active packaging materials from Poly(Lactic Acid)and Pectin composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active packaging of foods is receiving considerable attention from the food industry and food researchers. The ability to wrap foods in packaging materials that can provide additional functions, such as retaining freshness or preventing spoilage and pathogen growth, would be very important for the f...

  17. Hot-wire detector for chemically active materials used in gas chromatography

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Hot-filament detector analyzes chemically active materials used in gas chromatography. The detector reacts chemically with the effluent vapors in the gas chromatographic apparatus to change the electrical resistance of the filament as a function of the affluent composition. Due to the changes produced by chemical action on the filament, the system is often calibrated.

  18. UPLC-Q-TOF-MS analysis of non-volatile migrants from new active packaging materials.

    PubMed

    Aznar, M; Rodriguez-Lafuente, A; Alfaro, P; Nerin, C

    2012-10-01

    Ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry (MS) is a useful tool in the analysis of non-volatile compounds, and the use of a quadrupole-time-of-flight (Q-TOF) mass analyzer allows a high sensitivity and accuracy when acquiring full fragment mode, providing a high assurance of correct identification of unknown compounds. In this work, UPLC-Q-TOF-MS technology has been applied to the analysis of non-volatile migrants from new active packaging materials. The materials tested were based on polypropylene (PP), ethylene-vinyl alcohol copolymer (EVOH), and poly(ethylene terephthalate) (PET). The active packaging materials studied were one PP film containing a natural antioxidant, and two PP/EVOH films, two PET/EVOH films and one coextruded PP/EVOH/PP film containing natural antimicrobials. The chemical structure of several compounds was unequivocally identified. The analysis revealed the migration of some of the active substances used in the manufacture of active packaging, such as caffeine (0.07 ± 0.01 μg/g), carvacrol (0.31 ± 0.03 μg/g) and citral (0.20 ± 0.01 μg/g). Unintentionally added substances were also found, such as citral reaction compounds, or citral impurities present in the raw materials. PMID:22836481

  19. NREL Develops Accelerated Sample Activation Process for Hydrogen Storage Materials (Fact Sheet)

    SciTech Connect

    Not Available

    2010-12-01

    This fact sheet describes NREL's accomplishments in developing a new sample activation process that reduces the time to prepare samples for measurement of hydrogen storage from several days to five minutes and provides more uniform samples. Work was performed by NREL's Chemical and Materials Science Center.

  20. Metabolic activity of moulds as a factor of building materials biodegradation.

    PubMed

    Gutarowska, Beata

    2010-01-01

    This paper presents the effect of building materials on the growth and metabolic activity of moulds. In cultures of Aspergillus and Penicillium moulds grown on a model medium with the addition of building materials, the biomass of mycelium, its cellular components--glucan, chitin, ergosterol and the spectrum of enzymes and organic acids produced in the medium were investigated. It was found that on the medium with wallpaper moulds produced more biomass and extracellular enzymes, mainly glycolytic ones. On medium with mortar the growth of mycelium was impeded, production of biomass was 60% smaller, the quantity of chitin, glucan and ergosterol decreased 13-41%, and the activity of most enzymes was reduced; however the moulds intensively produced organic acids: malic, succinic and oxalic acid. The largest acid production activity was found in medium with addition of mortar; moulds produced the greatest variety of acids and in greater quantities than in the control medium. Metabolic activity of the moulds depends on the type of building material, and may lead to biodeterioration of these materials.

  1. Sorptive uptake of selenium with magnetite and its supported materials onto activated carbon.

    PubMed

    Kwon, Jae H; Wilson, Lee D; Sammynaiken, R

    2015-11-01

    Kinetic and equilibrium uptake studies of selenite in aqueous solution with synthetic magnetite (Mag-P), commercial magnetite (Mag-C), goethite, activated carbon (AC), and a composite material containing 19% magnetite supported on activated carbon (CM-19) were investigated. Kinetic uptake studies used a one-pot setup at pH 5.26 at variable temperature. Sampling of unbound selenite in-situ was achieved with analytical detection by atomic absorbance. The sorptive uptake at equilibrium and kinetic conditions are listed in descending order: goethite>Mag-P>Mag-C>CM-19. Kinetic uptake parameters reveal that Mag-P showed apparent negative values for the activation energy (E(a)) and the enthalpy of activation (ΔH(‡)), in agreement with a multi-step process for the kinetic uptake of selenite. By contrast, Mag-C, CM-19, and goethite showed positive values for E(a) and ΔH(‡). The uptake properties of the various sorbent materials with selenite are in accordance with the formation of inner- and out-sphere complexes. Leaching of iron from the composite material (CM-19) was attenuated due to the stabilizing effect of the magnetite within the pore sites and the surface of AC. Supported iron oxide nanomaterial composites represent a unique sorbent material with tunable uptake properties toward inorganic selenite in aqueous solution.

  2. MOF@activated carbon: a new material for adsorption of aldicarb in biological systems.

    PubMed

    de Oliveira, Carlos Alberto Fernandes; da Silva, Fausthon Fred; Jimenez, George Chaves; Neto, José Ferreira da S; de Souza, Daniela Maria Bastos; de Souza, Ivone Antônia; Alves, Severino

    2013-07-25

    A new composite was synthesized by the hydrothermal method using a 3D coordination network [Ln2(C4H4O4)3(H2O)2]·H2O (Ln = Eu and Tb) and activated carbon. The coordination network is formed within the pores of the charcoal, allowing for the use of this material as a detoxifying agent.

  3. Active Learning and Just-in-Time Teaching in a Material and Energy Balances Course

    ERIC Educational Resources Information Center

    Liberatore, Matthew W.

    2013-01-01

    The delivery of a material and energy balances course is enhanced through a series of in-class and out-of-class exercises. An active learning classroom is achieved, even at class sizes over 150 students, using multiple instructors in a single classroom, problem solving in teams, problems based on YouTube videos, and just-in-time teaching. To avoid…

  4. Poly(exTTF): a novel redox-active polymer as active material for li-organic batteries.

    PubMed

    Häupler, Bernhard; Burges, René; Friebe, Christian; Janoschka, Tobias; Schmidt, Daniel; Wild, Andreas; Schubert, Ulrich S

    2014-08-01

    The first polymer bearing exTTF units intended for the use in electrical charge storage is presented. The polymer undergoes a redox reaction involving two electrons at -0.20 V vs Fc/Fc(+) and is applied as active cathode material in a Li-organic battery. The received coin cells feature a theoretical capacity of 132 mAh g(-1) , a cell potential of 3.5 V, and a lifetime exceeding more than 250 cycles.

  5. Large-Area, Highly Ordered Array of Graphitic Carbon Materials Using Surface Active Chitosan Prepatterns.

    PubMed

    Baek, Youn-Kyoung; Kim, Dae Woo; Yang, Seung Bo; Lee, Jung-Goo; Kim, Young Kuk; Jung, Hee-Tae

    2015-02-01

    We demonstrate that chitosan prepatterns can generate not only highly periodic DNA pattern but also various types of graphitic carbon materials such as single-walled carbon nanotubes (SWNTs), graphene oxide (GO) and reduced graphene oxide (RGO). Scanning electron microscopy (SEM), fluorescence imaging and Raman spectroscopic results revealed that the graphitic carbon materials were selectively deposited on the surface of the periodic chitosan patterns by the electrostatic interaction between protonated amine groups of chitosan and the negative charged carbon materials. One proof-of-concept application of the system to the fabrication of electrical devices based on the micropatterns of SWNTs and RGO was also demonstrated. The strategy to use highly surface active chitosan pattern that can easily fabricate highly periodic pattern via a variety of lithographic tools may pave the way for the production of periodic arrays of graphitic carbon materials for large area device integration. PMID:26353637

  6. Suggestive techniques connected to medical interventions

    PubMed Central

    2013-01-01

    The paper introduces a series of articles where several detailed clinical examples will be presented on the effectiveness of using suggestive techniques in various fields of interventional medicine. The aim of this series is to raise the attention to the patients heightened openness to suggestions. By recognizing the unavoidable nature of suggestive effects on one hand we can eliminate unfavourable, negative suggestions and on the other hand go on and consciously apply positive, helpful variations. Research materials, reviews and case study will describe the way suggestions can reduce anxiety and stress connected to medical intervention, improve subjective well-being and cooperation, and increase efficiency by reducing treatment costs. PMID:24265898

  7. Ultrastrong Chemiluminescence Activity of Nanocarbon Materials after Ozonation and Their Effects on Different Chemiluminescent Systems.

    PubMed

    Yang, Feng; He, Duhong; Wang, Meina; Zheng, Baozhan; Wu, Li; Xiao, Dan; Guo, Yong

    2016-06-20

    Ozonized nanocarbon materials with different dimensionalities, structures, and components exhibited significantly different chemiluminescence (CL) activities. The ozonation time and the weight ratio of hydroxyl carbon nanotubes (d≈8 nm, hyCNTs-8) and graphene oxide (GO) strongly affected the CL activity of ozonized hybrids. Among GO, hyCNTs-8, and GO/hyCNTs-8, the GO/hyCNTs-8 hybrids exhibited the strongest CL-enhancing properties toward the luminol/H2 O2 system, in contrast to previous reports. This study provides new understanding of the CL activity and CL-enhancing properties of nanocarbon materials in signal-enhanced analytical and biomedical fields. PMID:27144483

  8. Effect of wall material on the antioxidant activity and physicochemical properties of Rubus fruticosus juice microcapsules.

    PubMed

    Díaz, Dafne I; Beristain, Cesar I; Azuara, Ebner; Luna, Guadalupe; Jimenez, Maribel

    2015-01-01

    Blackberry (Rubus fruticosus) juice possesses compounds with antioxidant activity, which can be protected by different biopolymers used in the microencapsulation. Therefore, the effects of cell wall material including maltodextrin (MD), Arabic gum (GA) and whey protein concentrate (WPC) were evaluated on the physicochemical and antioxidant properties of encapsulated blackberries using a spray-drying technique. Anthocyanin concentration, polymeric colour, total polyphenols, radical scavenging activity of the 1,1-diphenyl-2-picrilhydrazil radical, reducing power and the stability at different storage conditions were evaluated. GA and MD conferred a similar protection to the antioxidant compounds when the microcapsules were stored at low water activities (aw < 0.515) in contrast to at a high moisture content (aw > 0.902), whereas WPC presented a high protection. Therefore, the selection of the best wall material for blackberry juice encapsulation depends of the conditions of storage of the powder.

  9. Integration of active materials with silicon micromachining: applications to optical MEMS

    NASA Astrophysics Data System (ADS)

    Gouy, Jean-Philippe; Arakawa, Yasuhiko; Fujita, Hiroyuki

    2001-11-01

    Most of the MOEMS including optical switches and micro optical benches are developed on silicon. As for the MEMS, the main reason is that silicon has consistently been the material of choice for the microelectronics industry, due to a mature processing technology which offers the possibility to integrate MEMS devices with Integrated Circuits in a low cost batch fabrication process. However, since the beginning of Optoelectronic, silicon has been suffering from its poor efficiency to emit light because of its indirect band gap. Optical active devices can be integrated on silicon by combining specific active materials in order to keep the main advantage of silicon micromachining for MOEMS applications. This paper illustrates this purpose through one project developed in the frame of the LIMMS, joint laboratory between France and Japan. This project deals with optical active devices for which silicon micromachining technology has been employed to fabricate an organic semiconductors based light emitted diode on silicon substrate.

  10. Microstructure design of metal composite for active material in sodium nickel-iron chloride battery

    NASA Astrophysics Data System (ADS)

    Ahn, Cheol-Woo; Kim, Mangi; Hahn, Byung-Dong; Hong, Inchul; Kim, Woosung; Moon, Goyoung; Lee, Heesoo; Jung, Keeyoung; Park, Yoon-Cheol; Choi, Joon-Hwan

    2016-10-01

    In this manuscript, it is reported how the microstructure of metal composites can be designed to obtain excellent cycle performance in Na-(Ni,Fe)Cl2 battery. The microstructure consists of an active material and a conducting material. The conducting material is an active material as well as a conducting chain (an electron path). In Na-(Ni,Fe)Cl2 cells, it is preferable that Ni is selected as the conducting material, since the nickel chloride is not formed on the surface of Ni particles during the electrochemical reaction of Fe particles. In addition, the particle size of Ni should be smaller than that of Fe, in order to ensure that the conducting chain is well-connected. Through this design, the cycle performance of a Na-(Ni,Fe)Cl2 cell was significantly improved, compared to that of a Na-NiCl2 cell. At the 100th cycle, the charge/discharge capacity of a Na-(Ni,Fe)Cl2 cell was much higher than that of a Na-NiCl2 cell, approximately 42%.

  11. Effect of packing material on methane activation in a dielectric barrier discharge reactor

    SciTech Connect

    Jo, Sungkwon; Hoon Lee, Dae; Seok Kang, Woo; Song, Young-Hoon

    2013-12-15

    The conversion of methane is measured in a planar-type dielectric barrier discharge reactor using γ-Al{sub 2}O{sub 3} (sphere), α-Al{sub 2}O{sub 3} (sphere), and γ-Al{sub 2}O{sub 3} (16–20 mesh). Investigations on the surface properties and shape of the three packing materials clearly indicate that methane activation is considerably affected by the material used. Capacitances inside the discharge gap are estimated from charge–voltage plots, and a comparison of the generated and transferred charges for different packing conditions show that the difference in surface properties between γ- and α-phase Al{sub 2}O{sub 3} affects the discharge characteristics. Moreover, all packing conditions show different charge characteristics that are related to the electron density. Finally, the packing material's shape affects the local electron temperature, which is strongly related to methane conversion. The combined results indicate that both microscale and macroscale variations in a packing material affect the discharge characteristics, and a packing material should be considered carefully for effective methane activation.

  12. Effect of packing material on methane activation in a dielectric barrier discharge reactor

    NASA Astrophysics Data System (ADS)

    Jo, Sungkwon; Hoon Lee, Dae; Seok Kang, Woo; Song, Young-Hoon

    2013-12-01

    The conversion of methane is measured in a planar-type dielectric barrier discharge reactor using γ-Al2O3 (sphere), α-Al2O3 (sphere), and γ-Al2O3 (16-20 mesh). Investigations on the surface properties and shape of the three packing materials clearly indicate that methane activation is considerably affected by the material used. Capacitances inside the discharge gap are estimated from charge-voltage plots, and a comparison of the generated and transferred charges for different packing conditions show that the difference in surface properties between γ- and α-phase Al2O3 affects the discharge characteristics. Moreover, all packing conditions show different charge characteristics that are related to the electron density. Finally, the packing material's shape affects the local electron temperature, which is strongly related to methane conversion. The combined results indicate that both microscale and macroscale variations in a packing material affect the discharge characteristics, and a packing material should be considered carefully for effective methane activation.

  13. Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material

    DOEpatents

    Doeff, M.M.; Peng, M.Y.; Ma, Y.; Visco, S.J.; DeJonghe, L.C.

    1996-09-24

    An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M{sub x}Z{sub y}Mn{sub (1{minus}y)}O{sub 2}, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell. 11 figs.

  14. Performance evaluation of polyaniline as an active material for electrochemical capacitors

    SciTech Connect

    Rudge, A.; Davey, J.; Uribe, F.; Landeros, J. Jr.; Gottesfeld, S.

    1994-08-01

    This paper describes experiments which evaluate the performance of polyaniline (PAni) as an active material in electrochemical capacitors. We have performed constant current multicycle tests on prototype symmetric devices where the same conducting polymer serves as the active material on both electrodes. When electropolymerized at high current density in aqueous acid solution, PAni exhibits a micro-morphology consisting of a network of interwoven fibrils with high porosity. Thick PAni layers (>250 {mu}m) of the material can thus be electropolymerized onto a planar metal substrate without affecting the fast dynamics of the charge-discharge process. The aqueous PAni electrochemical capacitors exhibit rather low energy content because of limitations on the maximum applied voltage. However, due to their optimized morphology and the high conductivity of the aqueous acid solution, they exhibit relatively high power density. The PAni capacitor exhibits excellent cycle life (more than 25,000 cycles), provided the requirements on restricted cell voltage are met. This is a key result in the evaluation of conducting polymers as active materials in electrochemical capacitors. Scanning electron microscopy and impedance spectroscopy are used to provide information on this system.

  15. Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material

    DOEpatents

    Doeff, Marca M.; Peng, Marcus Y.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard C.

    1996-01-01

    An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell.

  16. CO2 Activated Carbon Aerogel with Enhanced Electrochemical Performance as a Supercapacitor Electrode Material.

    PubMed

    Lee, Eo Jin; Lee, Yoon Jae; Kim, Jeong Kwon; Hong, Ung Gi; Yi, Jongheop; Yoon, Jung Rag; Song, In Kyu

    2015-11-01

    Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde in ambient conditions. A series of activated carbon aerogels (ACA-X, X = 1, 2, 3, 4, 5, and 6 h) were then prepared by CO2 activation of CA with a variation of activation time (X) for use as an electrode material for supercapacitor. Specific capacitances of CA and ACA-X electrodes were measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Among the samples, ACA-5 h showed the highest BET surface area (2574 m2/g) and the highest specific capacitance (100 F/g). It was found that CO2 activation was a very efficient method for enhancing physicochemical property and supercapacitive electrochemical performance of activated carbon aerogel.

  17. Biopolymer-Activated Graphitic Carbon Nitride towards a Sustainable Photocathode Material

    PubMed Central

    Zhang, Yuanjian; Schnepp, Zoë; Cao, Junyu; Ouyang, Shuxin; Li, Ying; Ye, Jinhua; Liu, Songqin

    2013-01-01

    Photoelectrochemical (PEC) conversion of solar light into chemical fuels is one of the most promising solutions to the challenge of sustainable energy. Graphitic carbon (IV) nitride polymer (g-CN) is an interesting sustainable photocathode material due to low-cost, visible-light sensitivity, and chemical stability up to 500°C in air. However, grain boundary effects and limited active sites greatly hamper g-CN activity. Here, we demonstrate biopolymer-activation of g-CN through simultaneous soft-templating of a sponge-like structure and incorporation of active carbon-dopant sites. This facile approach results in an almost 300% increase in the cathodic PEC activity of g-CN under simulated solar-irradiation. PMID:23831846

  18. CO2 Activated Carbon Aerogel with Enhanced Electrochemical Performance as a Supercapacitor Electrode Material.

    PubMed

    Lee, Eo Jin; Lee, Yoon Jae; Kim, Jeong Kwon; Hong, Ung Gi; Yi, Jongheop; Yoon, Jung Rag; Song, In Kyu

    2015-11-01

    Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde in ambient conditions. A series of activated carbon aerogels (ACA-X, X = 1, 2, 3, 4, 5, and 6 h) were then prepared by CO2 activation of CA with a variation of activation time (X) for use as an electrode material for supercapacitor. Specific capacitances of CA and ACA-X electrodes were measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Among the samples, ACA-5 h showed the highest BET surface area (2574 m2/g) and the highest specific capacitance (100 F/g). It was found that CO2 activation was a very efficient method for enhancing physicochemical property and supercapacitive electrochemical performance of activated carbon aerogel. PMID:26726618

  19. Carbon fibers: Thermochemical recovery from advanced composite materials and activation to an adsorbent

    NASA Astrophysics Data System (ADS)

    Staley, Todd Andrew

    This research addresses an expanding waste disposal problem brought about by the increasing use of advanced composite materials, and the lack of technically and environmentally viable recycling methods for these materials. A thermochemical treatment process was developed and optimized for the recycling of advanced composite materials. Counter-current gasification was employed for the treatment of carbon fiber reinforced-epoxy resin composite wastes. These materials were treated, allowing the reclamation of the material's valuable components. As expected in gasification, the organic portion of the waste was thermochemically converted to a combustible gas with small amounts of organic compounds that were identified by GC/MS. These compounds were expected based on data in the literature. The composites contain 70% fiber reinforcement, and gasification yielded approximately 70% recovered fibers, representing nearly complete recovery of fibers from the waste. Through SEM and mechanical testing, the recovered carbon fibers were found to be structurally and mechanically intact, and amenable to re-use in a variety of applications, some of which were identified and tested. In addition, an application was developed for the carbon fiber component of the waste, as an activated carbon fiber adsorbent for the treatment of wastewaters. This novel class of adsorbent was found to have adsorption rates, for various organic molecules, up to a factor of ten times those of commercial granular activated carbon, and adsorption capacities similar to conventional activated carbons. Overall, the research addresses an existing environmental waste problem, employing a thermochemical technique to recycle and reclaim the waste. Components of the reclaimed waste material are then employed, after further modification, to address other existing and potential environmental waste problems.

  20. Push for new materials, chemicals from biomass sparks active R and D

    SciTech Connect

    Borman, S. )

    1990-09-01

    This paper discusses how a resurgence of interest in the production of new materials, chemicals, and fuels from biomass resources such as wood, cellulose, lignin, starch, and chitin is sparking active R and D efforts in these areas. Biobased materials and chemicals currently under development include composites of conventional plastics with lignocellulosics (chemicals from wood and other plant sources); lignocellulosic nonwoven mates that can be pressed into rigid shapes to form doors, walls, and even auto body parts; phenolic chemicals produced from wood waste and bark; membranes made from chitosan (a substance derived from crustacean shells); and biodegradable plastics containing starch.

  1. Sun-tracking optical element realized using thermally activated transparency-switching material.

    PubMed

    Apostoleris, Harry; Stefancich, Marco; Lilliu, Samuele; Chiesa, Matteo

    2015-07-27

    We present a proof of concept demonstration of a novel optical element: a light-responsive aperture that can track a moving light beam. The element is created using a thermally-activated transparency-switching material composed of paraffin wax and polydimethylsiloxane (PDMS). Illumination of the material with a focused beam causes the formation of a localized transparency at the focal spot location, due to local heating caused by absorption of a portion of the incident light. An application is proposed in a new design for a self-tracking solar collector. PMID:26367692

  2. Evaluation of homogeneity of a certified reference material by instrumental neutron activation analysis

    SciTech Connect

    Kratochvil, B.; Duke, M.J.M.; Ng, D.

    1986-01-01

    The homogeneity of the marine reference material TORT-1, a spray-dried and acetone-extracted hepatopancreatic material from the lobster, was tested for 26 elements by instrumental neutron activation analysis (INAA). Through a one-way analysis of variance based on six analyses on each of six bottles of TORT-1, it was concluded that the between-bottle heterogeneity is no greater than the within-bottle heterogeneity. The analytical results for those elements for which values were provided by NRC agree with the NRC values within 95% confidence limits. 8 references, 6 tables.

  3. Plant material as bioaccumulator of arsenic in soils affected by mining activities

    NASA Astrophysics Data System (ADS)

    Martínez-López, Salvadora; Martínez-Sánchez, Maria Jose; García-Lorenzo, Maria Luz; Pérez-Sirvent, Carmen

    2010-05-01

    Heavy metal contamination is an important environmental problem, since the metals are harmful to humans, animals and tend to bioaccumulate in the food chain. The aim of this study was to determine the total concentration of As, As (III) and As(V) in soil samples, leaves and roots of plant material, growing in a mining area in Spain (Murcia). Ditichia viscosa was used as the plant of reference. The concentrations of bioavailable As in plant samples were calculated by different soil chemical extraction methods; deionized water, 0.5N NaHCO3 (Olsen extraction), oxidizable medium, 0.5 HCl, 0.05M (NH4)2SO4, 0.005M DTPA and Mehra-Jackson extraction. For this study, fourteen samples were collected in the surrounding area of Sierra Minera and Portman Bay (Murcia, SE Spain). Samples were air dried and sieved to < 2mm for general analytical determinations. To determine the As content, soil samples were first ground to a fine powder using an agate ball mill. Fresh vegetable samples were separated into root and aboveground biomass and then lyophilized. Arsenic levels were obtained by using atomic fluorescence spectrometry with an automated continuous flow hydride generation (HG-AFS) spectrometer. Samples showed pH average values close to neutrality. Most samples showed a very low organic matter percentage. Electrical conductivity and calcium carbonate content were considerably low in most samples. The mineralogical analysis showed that the main minerals were quartz, muscovite, kaolinite and illite, while the minority minerals were alteration products derived of mining activities (iron oxides and hydroxides, siderite, jarosite and gypsum), calcite and feldspars. Although the plants do not absorb arsenic in the same proportion, the results suggest that a good relationship exists between the total content of As in soil and the total content in plant. The results showed that the arsenic content in roots was positively correlated with the oxidizable-organic matter and sulfides

  4. Nanocrosses of lead sulphate as the negative active material of lead acid batteries

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Gao, Pengran; Bu, Xianfu; Kuang, Guizhi; Liu, Wei; Lei, Lixu

    2014-10-01

    Lead sulphate transforms into PbO2 and Pb in the positive and negative electrodes, respectively, when a lead acid battery is charged, thus, it is an active material. It is also generally acknowledged that sulphation results in the failure of lead acid batteries; therefore, it is very interesting to find out how to make lead sulphate more electrochemically active. Here, we demonstrate that nanocrystalline lead sulphate can be used as excellent negative active material in lead acid batteries. The lead sulphate nanocrystals, which are prepared by a facile chemical precipitation of aqueous lead acetate and sodium sulphate in a few minutes, look like crosses with diameter of each arm being 100 nm to 3 μm. The electrode is effectively formed in much shorter time than traditional technique, yet it discharges a capacity of 103 mA h g-1 at the current density of 120 mA g-1, which is 24% higher than that discharged by the electrode made from leady oxide under the same condition. During 100% DOD cycles, more than 80% of that capacity remains in 550 cycles. These results show that lead sulphate can be a nice negative active material in lead acid batteries.

  5. Identification of primary aromatic amines in mutagenically active subfractions from coal liquefaction materials.

    PubMed

    Wilson, B W; Pelroy, R; Cresto, J T

    1980-11-01

    Gas-chromatographic mass spectral (GCMS) analyses were performed on mutagenically active components from the basic, basic tar and neutral tar subfractions of a coal-derived liquid heavy distillate. The latter material is a component fraction of an experimental oil produced in a solvent refined coal process (SRC II) pilot plant. Mutagenicity was determined with the Ames/Salmonella assay system. Thin-layer chromatography (TLC) was used to separate mutagenically active components of the basic, basic tar and neutral tar fractions from some of the other compounds contained in these complex materials. For the 3 fractions tested, mutagenic activity was localized in approx. the same TLC regions, with relative mobilities (Rf) ranging from 0.1 to 0.3. GCMS analysis of the TLC regions showed that the concentrations of primary aromatic amines, as obtained by measuring peak areas for the (M + 1)+ ion as formed in the chemical ionization mode, followed essentially the same distribution as the mutagenic activity. Primary aromatic amines identified in the active regions included aminonaphthalenes, aminoanthracenes, aminophenanthrenes, aminopyrenes and aminochrysenes. With the exception of small amounts of aminonaphthalene, primary aromatic amines were not found in TLC regions that lacked mutagenic activity.

  6. Classifying organic materials by oxygen-to-carbon elemental ratio to predict the activation regime of Cloud Condensation Nuclei (CCN)

    NASA Astrophysics Data System (ADS)

    Kuwata, M.; Shao, W.; Lebouteiller, R.; Martin, S. T.

    2013-05-01

    The governing highly soluble, slightly soluble, or insoluble activation regime of organic compounds as cloud condensation nuclei (CCN) was examined as a function of oxygen-to-carbon elemental ratio (O : C). New data were collected for adipic, pimelic, suberic, azelaic, and pinonic acids. Secondary organic materials (SOMs) produced by α-pinene ozonolysis and isoprene photo-oxidation were also included in the analysis. The saturation concentrations C of the organic compounds in aqueous solutions served as the key parameter for delineating regimes of CCN activation, and the values of C were tightly correlated to the O : C ratios. The highly soluble, slightly soluble, and insoluble regimes of CCN activation were found to correspond to ranges of [O : C] > 0.6, 0.2 < [O : C] < 0.6, and [O : C] < 0.2, respectively. These classifications were evaluated against CCN activation data of isoprene-derived SOM (O : C = 0.69-0.72) and α-pinene-derived SOM (O : C = 0.38-0.48). Isoprene-derived SOM had highly soluble activation behavior, consistent with its high O : C ratio. For α-pinene-derived SOM, although CCN activation can be modeled as a highly soluble mechanism, this behavior was not predicted by the O : C ratio, for which a slightly soluble mechanism was anticipated. Complexity in chemical composition, resulting in continuous water uptake and the absence of a deliquescence transition that can thermodynamically limit CCN activation, might explain the difference in the behavior of α-pinene-derived SOM compared to that of pure organic compounds. The present results suggest that atmospheric particles dominated by hydrocarbon-like organic components do not activate (i.e., insoluble regime) whereas those dominated by oxygenated organic components activate (i.e., highly soluble regime) for typical atmospheric cloud life cycles.

  7. Effect of different mulch materials on the soil dehydrogenase activity (DHA) in an organic pepper crop

    NASA Astrophysics Data System (ADS)

    Moreno, Marta M.; Peco, Jesús; Campos, Juan; Villena, Jaime; González, Sara; Moreno, Carmen

    2016-04-01

    The use biodegradable materials (biopolymers of different composition and papers) as an alternative to conventional mulches has increased considerably during the last years mainly for environmental reason. In order to assess the effect of these materials on the soil microbial activity during the season of a pepper crop organically grown in Central Spain, the soil dehydrogenase activity (DHA) was measured in laboratory. The mulch materials tested were: 1) black polyethylene (PE, 15 μm); black biopolymers (15 μm): 2) Mater-Bi® (corn starch based), 3) Sphere 4® (potato starch based), 4) Sphere 6® (potato starch based), 5) Bioflex® (polylactic acid based), 6) Ecovio® (polylactic acid based), 7) Mimgreen® (black paper, 85 g/m2). A randomized complete block design with four replications was adopted. The crop was drip irrigated following the water demand of each treatment. Soil samples (5-10 cm depth) under the different mulches were taken at different dates (at the beginning of the crop cycle and at different dates throughout the crop season). Additionally, samples of bare soil in a manual weeding and in an untreated control were taken. The results obtained show the negative effect of black PE on the DHA activity, mainly as result of the higher temperature reached under the mulch and the reduction in the gas interchange between the soil and the atmosphere. The values corresponding to the biodegradable materials were variable, although highlighting the low DHA activity observed under Bioflex®. In general, the uncovered treatments showed higher values than those reached under mulches, especially in the untreated control. Keywords: mulch, biodegradable, biopolymer, paper, dehydrogenase activity (DHA). Acknowledgements: the research was funded by Project RTA2011-00104-C04-03 from the INIA (Spanish Ministry of Economy and Competitiveness).

  8. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    SciTech Connect

    Rawl, Richard R; Scofield, Patricia A; Leggett, Richard Wayne; Eckerman, Keith F

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low-level NORM

  9. Materials

    NASA Technical Reports Server (NTRS)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  10. Facile synthesis, characterization, and antimicrobial activity of cellulose-chitosan-hydroxyapatite composite material: a potential material for bone tissue engineering.

    PubMed

    Mututuvari, Tamutsiwa M; Harkins, April L; Tran, Chieu D

    2013-11-01

    Hydroxyapatite (HAp) is often used as a bone-implant material because it is biocompatible and osteoconductive. However, HAp possesses poor rheological properties and it is inactive against disease-causing microbes. To improve these properties, we developed a green method to synthesize multifunctional composites containing: (1) cellulose (CEL) to impart mechanical strength; (2) chitosan (CS) to induce antibacterial activity thereby maintaining a microbe-free wound site; and (3) HAp. In this method, CS and CEL were co-dissolved in an ionic liquid (IL) and then regenerated from water. HAp was subsequently formed in situ by alternately soaking [CEL+CS] composites in aqueous solutions of CaCl2 and Na2 HPO4 . At least 88% of IL used was recovered for reuse by distilling the aqueous washings of [CEL+CS]. The composites were characterized using FTIR, XRD, and SEM. These composites retained the desirable properties of their constituents. For example, the tensile strength of the composites was enhanced 1.9 times by increasing CEL loading from 20% to 80%. Incorporating CS in the composites resulted in composites which inhibited the growth of both Gram positive (MRSA, S. aureus and VRE) and Gram negative (E. coli and P. aeruginosa) bacteria. These findings highlight the potential use of [CEL+CS+HAp] composites as scaffolds in bone tissue engineering.

  11. FACILE SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF CELLULOSE-CHITOSAN-HYDROXYAPATITE COMPOSITE MATERIAL, A POTENTIAL MATERIAL FOR BONE TISSUE ENGINEERING

    PubMed Central

    Mututuvari, Tamutsiwa M.; Harkins, April L.

    2013-01-01

    Hydroxyapatite (HAp) is often used as a bone-implant material because it is biocompatible and osteoconductive. However, HAp possesses poor rheological properties and it is inactive against disease-causing microbes. To improve these properties, we developed a green method to synthesize multifunctional composites containing: (1) cellulose (CEL) to impart mechanical strength; (2) chitosan (CS) to induce antibacterial activity thereby maintaining a microbe-free wound site; and (3) HAp. In this method, CS and CEL were co-dissolved in an ionic liquid (IL) and then regenerated from water. HAp was subsequently formed in situ by alternately soaking [CEL+CS] composites in aqueous solutions of CaCl2 and Na2HPO4. At least 88% of IL used was recovered for reuse by distilling the aqueous washings of [CEL+CS]. The composites were characterized using FTIR, XRD and SEM. These composites retained the desirable properties of their constituents. For example, the tensile strength of the composites was enhanced 1.9X by increasing CEL loading from 20% to 80%. Incorporating CS in the composites resulted in composites which inhibited the growth of both Gram positive (MRSA, S. aureus and VRE) and Gram negative (E. coli and P. aeruginosa) bacteria. These findings highlight the potential use of [CEL+CS+HAp] composites as scaffolds in bone tissue engineering. PMID:23595871

  12. Recognition of wall materials through active thermography coupled with numerical simulations.

    PubMed

    Pietrarca, Francesca; Mameli, Mauro; Filippeschi, Sauro; Fantozzi, Fabio

    2016-09-01

    In the framework of historical buildings, wall thickness as well as wall constituents are not often known a priori, and active IR thermography can be exploited as a nonintrusive method for detecting what kind of material lies beneath the external plaster layer. In the present work, the wall of a historical building is subjected to a heating stimulus, and the surface temperature temporal trend is recorded by an IR camera. A hybrid numerical model is developed in order to simulate the transient thermal response of a wall made of different known materials underneath the plaster layer. When the numerical thermal contrast and the appearance time match with the experimental thermal images, the material underneath the plaster can be qualitatively identified. PMID:27607254

  13. Study of passive and active optical waveguides: Synthesis, processing and characterization of materials

    NASA Astrophysics Data System (ADS)

    Yoshida, Makoto

    Photonics uses photons for information and image processing, and has been touted as the technology of the 21 st century. An optical waveguide is a key component of an optical integrated circuit which is the optical analog of an electrical integrated circuit (IC). Electrical transistor IC technology resulted in an enormous impact on society, and it changed our life styles from the age of the vacuum tube. The advent of the optical integrated circuit is expected to have the same impact on society as the electronic IC. Various optical circuit elements are interrelated to materials, therefore, the study and the better understanding of materials and processing have been receiving a great deal of attention. My research focuses on the study of optical waveguide materials and their processings in terms of passive and active optical waveguides. The first target was to establish a method for measuring the refractive index and optical propagation loss of optical waveguides. The second target was to develop passive waveguide materials which can route, split and combine optical signals on a substrate. There are several requirements for waveguiding, such as high optical transparency, proper refractive index, and proper thickness. The sol-gel technique was used to meet the requirements, and several types of organic: inorganic composite materials were developed. The third target involved the development of processing methods to fabricate channel waveguides using the above-mentioned passive and active waveguide materials. Selective laser densification was developed for sol-gel composite materials. Use of trenched substrates and photobleaching were also studied. The last target was to develop an active material which could process optical signals using the electrooptic effect. A crosslinked urethane polymer with a newly synthesized chromophore was used due to its high thermal stability and optical transparency. In order to obtain second order nonlinearity, macroscopic molecular

  14. Broad spectrum antibacterial and antifungal polymeric paint materials: synthesis, structure-activity relationship, and membrane-active mode of action.

    PubMed

    Hoque, Jiaul; Akkapeddi, Padma; Yadav, Vikas; Manjunath, Goutham B; Uppu, Divakara S S M; Konai, Mohini M; Yarlagadda, Venkateswarlu; Sanyal, Kaustuv; Haldar, Jayanta

    2015-01-28

    Microbial attachment and subsequent colonization onto surfaces lead to the spread of deadly community-acquired and hospital-acquired (nosocomial) infections. Noncovalent immobilization of water insoluble and organo-soluble cationic polymers onto a surface is a facile approach to prevent microbial contamination. In the present study, we described the synthesis of water insoluble and organo-soluble polymeric materials and demonstrated their structure-activity relationship against various human pathogenic bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and beta lactam-resistant Klebsiella pneumoniae as well as pathogenic fungi such as Candida spp. and Cryptococcus spp. The polymer coated surfaces completely inactivated both bacteria and fungi upon contact (5 log reduction with respect to control). Linear polymers were more active and found to have a higher killing rate than the branched polymers. The polymer coated surfaces also exhibited significant activity in various complex mammalian fluids such as serum, plasma, and blood and showed negligible hemolysis at an amount much higher than minimum inhibitory amounts (MIAs). These polymers were found to have excellent compatibility with other medically relevant polymers (polylactic acid, PLA) and commercial paint. The cationic hydrophobic polymer coatings disrupted the lipid membrane of both bacteria and fungi and thus showed a membrane-active mode of action. Further, bacteria did not develop resistance against these membrane-active polymers in sharp contrast to conventional antibiotics and lipopeptides, thus the polymers hold great promise to be used as coating materials for developing permanent antimicrobial paint. PMID:25541751

  15. Broad spectrum antibacterial and antifungal polymeric paint materials: synthesis, structure-activity relationship, and membrane-active mode of action.

    PubMed

    Hoque, Jiaul; Akkapeddi, Padma; Yadav, Vikas; Manjunath, Goutham B; Uppu, Divakara S S M; Konai, Mohini M; Yarlagadda, Venkateswarlu; Sanyal, Kaustuv; Haldar, Jayanta

    2015-01-28

    Microbial attachment and subsequent colonization onto surfaces lead to the spread of deadly community-acquired and hospital-acquired (nosocomial) infections. Noncovalent immobilization of water insoluble and organo-soluble cationic polymers onto a surface is a facile approach to prevent microbial contamination. In the present study, we described the synthesis of water insoluble and organo-soluble polymeric materials and demonstrated their structure-activity relationship against various human pathogenic bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and beta lactam-resistant Klebsiella pneumoniae as well as pathogenic fungi such as Candida spp. and Cryptococcus spp. The polymer coated surfaces completely inactivated both bacteria and fungi upon contact (5 log reduction with respect to control). Linear polymers were more active and found to have a higher killing rate than the branched polymers. The polymer coated surfaces also exhibited significant activity in various complex mammalian fluids such as serum, plasma, and blood and showed negligible hemolysis at an amount much higher than minimum inhibitory amounts (MIAs). These polymers were found to have excellent compatibility with other medically relevant polymers (polylactic acid, PLA) and commercial paint. The cationic hydrophobic polymer coatings disrupted the lipid membrane of both bacteria and fungi and thus showed a membrane-active mode of action. Further, bacteria did not develop resistance against these membrane-active polymers in sharp contrast to conventional antibiotics and lipopeptides, thus the polymers hold great promise to be used as coating materials for developing permanent antimicrobial paint.

  16. Electrodes and electrochemical storage cells utilizing tin-modified active materials

    DOEpatents

    Anani, Anaba; Johnson, John; Lim, Hong S.; Reilly, James; Schwarz, Ricardo; Srinivasan, Supramaniam

    1995-01-01

    An electrode has a substrate and a finely divided active material on the substrate. The active material is ANi.sub.x-y-z Co.sub.y Sn.sub.z, wherein A is a mischmetal or La.sub.1-w M.sub.w, M is Ce, Nd, or Zr, w is from about 0.05 to about 1.0, x is from about 4.5 to about 5.5, y is from 0 to about 3.0, and z is from about 0.05 to about 0.5. An electrochemical storage cell utilizes such an electrode as the anode. The storage cell further has a cathode, a separator between the cathode and the anode, and an electrolyte.

  17. Assessment of alpha activity of building materials commonly used in West Bengal, India.

    PubMed

    Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

    2008-02-01

    This paper, reports for the first time, an extensive study of alpha activity of all widely used building materials (plaster of Paris, stone chips, marble, white cement, mosaic stone, limestone, sand, granite, cement brick, asbestos, red brick, cement tile, ceramic tile and ceramics) in West Bengal, India. The alpha activities have been measured using Solid State Nuclear Track Detector (SSNTD), a very sensitive detector for alpha particles. The samples were collected from local markets of Kolkata. The measured average alpha activities ranged from 22.7+/-2.5 to 590.6+/-16.8Bqkg(-1). The alpha activity of ceramic tiles was highest and provides additional data to estimate the effect of environmental radiation exposure on human health.

  18. Recent progress in blanket materials development in the Broader Approach activities

    NASA Astrophysics Data System (ADS)

    Nishitani, T.; Tanigawa, H.; Nozawa, T.; Jitsukawa, S.; Nakamichi, M.; Hoshino, T.; Yamanishi, T.; Baluc, N.; Möslang, A.; Lindou, R.; Tosti, S.; Hodgson, E. R.; Clement Lorenzo, S.; Kohyama, A.; Kimura, A.; Shikama, T.; Hayashi, K.; Araki, M.

    2011-10-01

    As a part of the Broader Approach activities, R&D on blanket related materials, reduced-activation ferritic martensitic (RAFM) steels as a structural material, SiC f/SiC composites for flow channel insert in the liquid blanket and/or use as advanced structural material, advanced tritium breeders and neutron multiplier, has been initiated directed at DEMO. As part of the RAFM steel mass production development, a 5 ton heat of RAFM steel (F82H) was procured by Electro Slag Re-melting as the secondary melting method, which was effective in controlling unwanted impurities. An 11 ton heat of EUROFER was also produced. For the SiC f/SiC composite development, NITE- and CVI-SiC f/SiC composites were prepared as reference materials and preliminary mechanical and physical properties were measured. Also compatibility tests between SiC and Pb-17Li have been prepared, related to the He-cooled Li-Pb blanket concept. For the beryllide neutron multiplayer Be-Ti alloy development, large size rods of about 30 mm diameter were fabricated successfully in EU.

  19. Verification of cardiac mechanics software: benchmark problems and solutions for testing active and passive material behaviour

    PubMed Central

    Gurev, Viatcheslav; Arens, Sander; Augustin, Christoph M.; Baron, Lukas; Blake, Robert; Bradley, Chris; Castro, Sebastian; Crozier, Andrew; Favino, Marco; Fastl, Thomas E.; Fritz, Thomas; Gao, Hao; Gizzi, Alessio; Griffith, Boyce E.; Hurtado, Daniel E.; Krause, Rolf; Luo, Xiaoyu; Nash, Martyn P.; Pezzuto, Simone; Plank, Gernot; Rossi, Simone; Ruprecht, Daniel; Seemann, Gunnar; Smith, Nicolas P.; Sundnes, Joakim; Rice, J. Jeremy; Trayanova, Natalia; Wang, Dafang; Jenny Wang, Zhinuo; Niederer, Steven A.

    2015-01-01

    Models of cardiac mechanics are increasingly used to investigate cardiac physiology. These models are characterized by a high level of complexity, including the particular anisotropic material properties of biological tissue and the actively contracting material. A large number of independent simulation codes have been developed, but a consistent way of verifying the accuracy and replicability of simulations is lacking. To aid in the verification of current and future cardiac mechanics solvers, this study provides three benchmark problems for cardiac mechanics. These benchmark problems test the ability to accurately simulate pressure-type forces that depend on the deformed objects geometry, anisotropic and spatially varying material properties similar to those seen in the left ventricle and active contractile forces. The benchmark was solved by 11 different groups to generate consensus solutions, with typical differences in higher-resolution solutions at approximately 0.5%, and consistent results between linear, quadratic and cubic finite elements as well as different approaches to simulating incompressible materials. Online tools and solutions are made available to allow these tests to be effectively used in verification of future cardiac mechanics software. PMID:26807042

  20. Photo-induced optical activity in phase-change memory materials.

    PubMed

    Borisenko, Konstantin B; Shanmugam, Janaki; Williams, Benjamin A O; Ewart, Paul; Gholipour, Behrad; Hewak, Daniel W; Hussain, Rohanah; Jávorfi, Tamás; Siligardi, Giuliano; Kirkland, Angus I

    2015-03-05

    We demonstrate that optical activity in amorphous isotropic thin films of pure Ge2Sb2Te5 and N-doped Ge2Sb2Te5N phase-change memory materials can be induced using rapid photo crystallisation with circularly polarised laser light. The new anisotropic phase transition has been confirmed by circular dichroism measurements. This opens up the possibility of controlled induction of optical activity at the nanosecond time scale for exploitation in a new generation of high-density optical memory, fast chiroptical switches and chiral metamaterials.

  1. Determination of sodium in biological materials by instrumental neutron activation analysis.

    PubMed

    Cunningham, W C; Capar, S G; Anderson, D L

    1997-01-01

    A formalized method for determining sodium in biological materials by instrumental neutron activation analysis is presented. The method includes common procedures from the numerous options available to this historically nonformalized analytical technique. The number of procedural options is restricted to minimize the method's complexity, yet the method is still applicable to a variety of neutron activation facilities. High accuracy and precision are achieved by placing bounds on allowed uncertainty at critical stages of the analysis. Analytical results from the U.S. Food and Drug Administration laboratory and 4 other laboratories demonstrate the method's performance.

  2. Studies on Supercapacitor Electrode Material from Activated Lignin-Derived Mesoporous Carbon

    SciTech Connect

    Saha, Dipendu; Li, Yunchao; Bi, Zhonghe; Chen, Jihua; Keum, Jong Kahk; Hensley, Dale K; Grappe, Hippolyte A.; Meyer III, Harry M; Dai, Sheng; Paranthaman, Mariappan Parans; Naskar, Amit K

    2014-01-01

    We synthesized mesoporous carbon from pre-cross-linked lignin gel impregnated with a surfactant as the pore-forming agent, and then activated the carbon through physical and chemical methods to obtain activated mesoporous carbon. The activated mesoporous carbons exhibited 1.5- to 6-fold increases in porosity with a maximum BET specific surface area of 1148 m2/g and a pore volume of 1.0 cm3/g. Slow physical activation helped retain dominant mesoporosity; however, aggressive chemical activation caused some loss of the mesopore volume fraction. Plots of cyclic voltammetric data with the capacitor electrode made from these carbons showed an almost rectangular curve depicting the behavior of ideal double-layer capacitance. Although the pristine mesoporous carbon exhibited the same range of surface-area-based capacitance as that of other known carbon-based supercapacitors, activation decreased the surface-area-based specific capacitance and increased the gravimetric-specific capacitance of the mesoporous carbons. Surface activation lowered bulk density and electrical conductivity. Warburg impedance as a vertical tail in the lower frequency domain of Nyquist plots supported good supercapacitor behavior for the activated mesoporous carbons. Our work demonstrated that biomass-derived mesoporous carbon materials continue to show potential for use in specific electrochemical applications.

  3. Estrogenic activity of dental materials and bisphenol-A related chemicals in vitro.

    PubMed

    Hashimoto, Y; Nakamura, M

    2000-09-01

    Twenty-eight chemicals used as dental materials and bisphenol-A related chemicals were diluted with DMSO to concentrations ranging from 10(-7) to 10(-3) M and tested for estrogenicity. Bisphenol-A (BPA), bisphenol-F (BPF) and bisphenol-A-bischloroformate (BPACF) showed estrogenic activity using the yeast two-hybrid system, and BPA, BPF, BPACF and bisphenol-S (BPS) showed estrogenic activity using the fluorescence polarization system. However, none of the remaining chemicals and none of the dental materials showed any activity at concentrations between 10(-7) and 10(-3) M. Although BPA, BPF, BPACF, bisphenol-A-dimethacrylate and BPS showed estrogenic activity in the E-screen test, the remaining chemicals did not. Thus, most of the chemicals showed consistent results, either positive or negative, by the three testing methods, while two chemicals showed conflicting results. Further studies, together with in vivo and epidemiological examinations, are required. Elucidation of the structure-activity relationships of these chemicals is also needed to estimate the estrogenicity of a chemical from its structure.

  4. Energetic materials research and development activities at Sandia National Laboratories supported under DP-10 programs

    SciTech Connect

    Ratzel, A.C. III

    1998-09-01

    This report provides summary descriptions of Energetic Materials (EM) Research and Development activities performed at Sandia National Laboratories and funded through the Department of Energy DP-10 Program Office in FY97 and FY98. The work falls under three major focus areas: EM Chemistry, EM Characterization, and EM Phenomenological Model Development. The research supports the Sandia component mission and also Sandia's overall role as safety steward for the DOE Nuclear Weapons Complex.

  5. Using Photon Activation Analysis To Determine Concentrations Of Unknown Components In Reference Materials

    SciTech Connect

    Green, Jaromy; Sun, Zaijing; Wells, Doug; Maschner, Herb

    2011-06-01

    Using certified multi-element reference materials for instrumental analyses one frequently is confronted with the embarrassing fact that the concentration of some desired elements are not given in the respective certificate, nonetheless are detectable, e.g. by photon activation analysis (PAA). However, these elements might be determinable with sufficient quality of the results using scaling parameters and the well-known quantities of a reference element within the reference material itself. Scaling parameters include: activation threshold energy, Giant Dipole Resonance (GDR) peak and endpoint energy of the bremsstrahlung continuum; integrated photo-nuclear cross sections for the isotopes of the reference element; bremsstrahlung continuum integral; target thickness; photon flux density. Photo-nuclear cross sections from the unreferenced elements must be known, too. With these quantities, the integral was obtained for both the known and unknown elements resulting in an inference of the concentration of the unreported element based upon the reported value, thus also the concentration of the unreferenced element in the reference material. A similar method to determine elements using the basic nuclear and experimental data has been developed for thermal neutron activation analysis some time ago (k{sub 0} Method).

  6. Mutagenicity studies in a tyre plant: in vitro activity of workers' urinary concentrates and raw materials.

    PubMed

    Crebelli, R; Paoletti, A; Falcone, E; Aquilina, G; Fabri, G; Carere, A

    1985-07-01

    The possible contribution to urinary mutagenicity of occupational exposures in the rubber industry was studied by assaying the urine concentrates of 72 workmen (44 smokers) employed in a tyre plant. Twenty three clerks (16 smokers) engaged in the administrative department of the same factory served as presumptive unexposed controls. XAD-2 resin concentrates of urine samples were assayed in the plate incorporation test and in the microtitre fluctuation assay with Salmonella typhimurium strains TA1535, TA98, and TA100. Furthermore, the in vitro mutagenicity of the major raw materials in use at the plant was determined in the plate incorporation assay with S typhimurium strains TA1535, TA1537, TA98, and TA100. The results obtained from the urinary mutagenicity study show that smoking habits, but not occupation, were statistically significantly related to the appearance of a urinary mutagenicity that was detectable with strain TA98. A possible synergistic effect of occupation with smoking was observed among tyre builders who were also smokers. The study of the raw materials showed that three technical grade materials were weakly active as mutagens in strain TA98 in the absence (poly-p-dinitrosobenzene) or in the presence of metabolic activation (mixed diaryl-p-phenylendiamines and tetramethyltiuram disulphide). The latter chemical was also weakly active in strain TA100. PMID:4015996

  7. Alkali-Activated Aluminium-Silicate Composites as Insulation Materials for Industrial Application

    NASA Astrophysics Data System (ADS)

    Dembovska, L.; Bajare, D.; Pundiene, I.; Bumanis, G.

    2015-11-01

    The article reports on the study of thermal stability of alkali-activated aluminium- silicate composites (ASC) at temperature 800-1100°C. ASC were prepared by using calcined kaolinite clay, aluminium scrap recycling waste, lead-silicate glass waste and quartz sand. As alkali activator, commercial sodium silicate solution modified with an addition of sodium hydroxide was used. The obtained alkali activation solution had silica modulus Ms=1.67. Components of aluminium scrap recycling waste (aluminium nitride (AlN) and iron sulphite (FeSO3)) react in the alkali media and create gases - ammonia and sulphur dioxide, which provide the porous structure of the material [1]. Changes in the chemical composition of ASC during heating were identified and quantitatively analysed by using DTA/TG, dimension changes during the heating process were determined by using HTOM, pore microstructure was examined by SEM, and mineralogical composition of ASC was determined by XRD. The density of ASC was measured in accordance with EN 1097-7. ASC with density around 560 kg/m3 and heat resistance up to 1100°C with shrinkage less than 5% were obtained. The intended use of this material is the application as an insulation material for industrial purposes at elevated temperatures.

  8. Critical Dimensions of Water-tamped Slabs and Spheres of Active Material

    DOE R&D Accomplishments Database

    Greuling, E.; Argo, H.: Chew, G.; Frankel, M. E.; Konopinski, E.J.; Marvin, C.; Teller, E.

    1946-08-06

    The magnitude and distribution of the fission rate per unit area produced by three energy groups of moderated neutrons reflected from a water tamper into one side of an infinite slab of active material is calculated approximately in section II. This rate is directly proportional to the current density of fast neutrons from the active material incident on the water tamper. The critical slab thickness is obtained in section III by solving an inhomogeneous transport integral equation for the fast-neutron current density into the tamper. Extensive use is made of the formulae derived in "The Mathematical Development of the End-Point Method" by Frankel and Goldberg. In section IV slight alterations in the theory outlined in sections II and III were made so that one could approximately compute the critical radius of a water-tamper sphere of active material. The derived formulae were applied to calculate the critical dimensions of water-tamped slabs and spheres of solid UF{sub 6} leaving various (25) isotope enrichment fractions. Decl. Dec. 16, 1955.

  9. Using Electronic Neutron Generators in Active Interrogation to Detect Shielded Fissionable Material

    SciTech Connect

    D. L. Chichester; E. H. Seabury

    2008-10-01

    Experiments have been performed at Idaho National Laboratory to study methodology and instrumentation for performing neutron active interrogation die-away analyses for the purpose of detecting shielded fissionable material. Here we report initial work using a portable DT electronic neutron generator with a He-3 fast neutron detector to detect shielded fissionable material including >2 kg quantities of enriched uranium and plutonium. Measurements have been taken of bare material as well as of material hidden within a large plywood cube. Results from this work have demonstrated the efficacy of the die-away neutron measurement technique for quickly detecting the presence of special nuclear material hidden within plywood shields by analyzing the time dependent neutron signals in-between neutron generator pulses. Using a DT electronic neutron generator operating at 300 Hz with a yield of approximately 0.36 x 10**8 neutrons per second, 2.2 kg of enriched uranium hidden within a 0.60 m x 0.60 m x 0.70 m volume of plywood was positively detected with a measurement signal 2-sigma above the passive background within 1 second. Similarly, for a 500 second measurement period a lower detection limit of approaching the gram level could be expected with the same simple set-up.

  10. Genome-wide identification and expression analysis of the mitogen-activated protein kinase gene family from banana suggest involvement of specific members in different stages of fruit ripening.

    PubMed

    Asif, Mehar Hasan; Lakhwani, Deepika; Pathak, Sumya; Bhambhani, Sweta; Bag, Sumit K; Trivedi, Prabodh Kumar

    2014-03-01

    Mitogen-activated protein kinases (MAPKs) are important components of the tripartite mitogen-activated protein kinase signaling cascade and play an important role in plant growth and development. Although members of the MAPK gene family have been identified in model plants, little information is available regarding this gene family in fruit crops. In this study, we carried out a computational analysis using the Musa Genome database to identify members of the MAPK gene family in banana, an economically important crop and the most popular fruit worldwide. Our analysis identified 25 members of the MAP kinase (MAPK or MPK) gene family. Phylogenetic analyses of MPKs in Arabidopsis, Oryza, and Populus have classified these MPKs into four subgroups. The presence of conserved domains in the deduced amino acid sequences, phylogeny, and genomic organization strongly support their identity as members of the MPK gene family. Expression analysis during ethylene-induced banana fruit ripening suggests the involvement of several MPKs in the ethylene signal transduction pathway that are necessary for banana fruit ripening. Analysis of the cis-regulatory elements in the promoter regions and the involvement of the identified MPKs in various cellular processes, as analyzed using Pathway Studio, suggest a role for the banana MPK gene family in diverse functions related to growth, development, and the stress response. This report is the first concerning the identification of members of a gene family and the elucidation of their role in various processes using the Musa Genome database. PMID:24275941

  11. Incorporation of inorganic material in anoxic/aerobic-activated sludge system mixed liquor.

    PubMed

    Wentzel, M C; Ubisi, M F; Lakay, M T; Ekama, G A

    2002-12-01

    In the bioreactor of the nitrification denitrification (ND)-activated sludge system, the mixed liquor is made up of organic and inorganic materials. In the current design procedures and simulation models, the influent wastewater characteristics and biological processes that influence the bioreactor mixed liquor organic solids (as volatile suspended solids, VSS, or COD) are explicitly included. However, the mixed liquor total suspended solids (TSS, i.e. organic + inorganic solids) are calculated simply from empirical ratios of VSS/TSS. The TSS concentration is fundamental in the design of secondary settling tanks and waste activated sludge disposal. Clearly, the empirical approach to obtaining an estimate for TSS is not satisfactory within the framework of a fundamentally based model. Accordingly, the incorporation of the inorganic material present in the influent wastewater into ND-activated sludge system mixed liquor was investigated. From an experimental investigation into the distribution of inorganics in the influent, mixed liquor and effluent of a laboratory-scale ND-activated sludge system, it was concluded inter alia that (i) of the total inorganic solids in the influent, only a small fraction (2.8-7.5%) is incorporated into the mixed liquor, (ii) most of the inorganics in the influent (mean 88%) and effluent (mean 98.5%) are in the dissolved form, the balance being particulate, and (iii) the influent and effluent inorganic dissolved solids concentrations are closely equal (mean effluent to influent ratio 100%). Further, a number of models were developed to quantify the mixed liquor inorganic, and, hence, total solids. From an evaluation of these models against the experimental data, it would appear that the best approach to model the incorporation of inorganics into the activated sludge mixed liquor is to follow the concepts and principles used to develop the existing models for organic materials. With this approach, reasonably close correlation between

  12. Assessment of Uncertainty in the Determination of Activation Energy for Polymeric Materials

    NASA Technical Reports Server (NTRS)

    Darby, Stephania P.; Landrum, D. Brian; Coleman, Hugh W.

    1998-01-01

    An assessment of the experimental uncertainty in obtaining the kinetic activation energy from thermogravimetric analysis (TGA) data is presented. A neat phenolic resin, Borden SC1O08, was heated at three heating rates to obtain weight loss vs temperature data. Activation energy was calculated by two methods: the traditional Flynn and Wall method based on the slope of log(q) versus 1/T, and a modification of this method where the ordinate and abscissa are reversed in the linear regression. The modified method produced a more accurate curve fit of the data, was more sensitive to data nonlinearity, and gave a value of activation energy 75 percent greater than the original method. An uncertainty analysis using the modified method yielded a 60 percent uncertainty in the average activation energy. Based on this result, the activation energy for a carbon-phenolic material was doubled and used to calculate the ablation rate In a typical solid rocket environment. Doubling the activation energy increased surface recession by 3 percent. Current TGA data reduction techniques that use the traditional Flynn and Wall approach to calculate activation energy should be changed to the modified method.

  13. Impedance spectroscopy study of a catechol-modified activated carbon electrode as active material in electrochemical capacitor

    NASA Astrophysics Data System (ADS)

    Cougnon, C.; Lebègue, E.; Pognon, G.

    2015-01-01

    Modified activated carbon (Norit S-50) electrodes with electrochemical double layer (EDL) capacitance and redox capacitance contributions to the electric charge storage were tested in 1 M H2SO4 to quantify the benefit and the limitation of the surface redox reactions on the electrochemical performances of the resulting pseudo-capacitive materials. The electrochemical performances of an electrochemically anodized carbon electrode and a catechol-modified carbon electrode, which make use both EDL capacitance of the porous structure of the carbon and redox capacitance, were compared to the performances obtained for the pristine carbon. Nitrogen gas adsorption measurements have been used for studying the impact of the grafting on the BET surface area, pore size distribution, pore volume and average pore diameter. The electrochemical behavior of carbon materials was studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The EIS data were discussed by using a complex capacitance model that allows defining the characteristic time constant, the global capacitance and the frequency at which the maximum charge stored is reached. The EIS measurements were achieved at different dc potential values where a redox activity occurs and the evolution of the capacitance and the capacitive relaxation time with the electrode potential are presented. Realistic galvanostatic charge/discharge measurements performed at different current rates corroborate the results obtained by impedance.

  14. Legal Education Reform: Modest Suggestions.

    ERIC Educational Resources Information Center

    Watson, Alan

    2001-01-01

    Based on harsh criticism of legal education by students, offers suggestions for improvement that do not require additional time for law studies, will increase the exposure of students both to law as practice and to law as an intellectual discipline, and involve no greater burden on law schools. A main suggestion involves elimination of teaching…

  15. Photocatalytic activity of titanium dioxide modified concrete materials - influence of utilizing recycled glass cullets as aggregates.

    PubMed

    Chen, Jun; Poon, Chi-Sun

    2009-08-01

    Combining the use of photocatalysts with cementitious materials is an important development in the field of photocatalytic air pollution mitigation. This paper presents the results of a systematic study on assessing the effectiveness of pollutant degradation by concrete surface layers that incorporate a photocatalytic material - Titanium Dioxide. The photocatalytic activity of the concrete samples was determined by photocatalytic oxidation of nitric oxide (NO) in the laboratory. Recycled glass cullets, derived from crushed waste beverage bottles, were used to replace sand in preparing the concrete surface layers. Factors, which may affect the pollutant removal performance of the concrete layers including glass color, aggregate size and curing age, were investigated. The results show a significant enhancement of the photocatalytic activity due to the use of glass cullets as aggregates in the concrete layers. The samples fabricated with clear glass cullets exhibited threefold NO removal efficiency compared to the samples fabricated with river sand. The light transmittance property of glass was postulated to account for the efficiency improvement, which was confirmed by a separate simulation study. But the influence of the size of glass cullets was not evident. In addition, the photocatalytic activity of concrete surface layers decreased with curing age, showing a loss of 20% photocatalytic activity after 56-day curing. PMID:19540649

  16. Photocatalytic activity of titanium dioxide modified concrete materials - influence of utilizing recycled glass cullets as aggregates.

    PubMed

    Chen, Jun; Poon, Chi-Sun

    2009-08-01

    Combining the use of photocatalysts with cementitious materials is an important development in the field of photocatalytic air pollution mitigation. This paper presents the results of a systematic study on assessing the effectiveness of pollutant degradation by concrete surface layers that incorporate a photocatalytic material - Titanium Dioxide. The photocatalytic activity of the concrete samples was determined by photocatalytic oxidation of nitric oxide (NO) in the laboratory. Recycled glass cullets, derived from crushed waste beverage bottles, were used to replace sand in preparing the concrete surface layers. Factors, which may affect the pollutant removal performance of the concrete layers including glass color, aggregate size and curing age, were investigated. The results show a significant enhancement of the photocatalytic activity due to the use of glass cullets as aggregates in the concrete layers. The samples fabricated with clear glass cullets exhibited threefold NO removal efficiency compared to the samples fabricated with river sand. The light transmittance property of glass was postulated to account for the efficiency improvement, which was confirmed by a separate simulation study. But the influence of the size of glass cullets was not evident. In addition, the photocatalytic activity of concrete surface layers decreased with curing age, showing a loss of 20% photocatalytic activity after 56-day curing.

  17. Effect of gamma irradiation on fluoride release and antibacterial activity of resin dental materials.

    PubMed

    Carvalho, Fabíola Galbiatti de; Fucio, Suzana Beatriz Portugal de; Pascon, Fernanda Miori; Kantovitz, Kamila Rosamilia; Correr-Sobrinho, Lourenço; Puppin-Rontani, Regina Maria

    2009-01-01

    This study evaluated the effect of gamma irradiation on fluoride release and antibacterial activity of FluroShield (FS) and Clearfil Protect Bond (CPB). Four groups were formed: G1-FS + gamma; G2-FS without gamma; G3-CPB + gamma; G4-CPB without gamma. For fluoride release analysis, 12 disks of each material were prepared and covered with nail polish, except for one side (50.4 mm(2) area). G1 and G3 were sterilized with a 14.5 KGy dose at 27 degrees C for 24 h, while G2 and G4 (controls) were not sterilized and were maintained under the same time and temperature conditions. Fluoride release measurements were made in duplicate (n=6) by an ion specific electrode. The antibacterial activity of the CPB and FS against Streptococcus mutans after gamma sterilization was evaluated by the agar-disc diffusion method. The diameter of the zones of microbial growth inhibition was recorded after 48 h. Data were analyzed statistically by ANOVA and Tukey's test (alpha=5%). Gamma sterilization decreased the fluoride release of FS by approximately 50%, while CPB was not affected. There was no statistically significant difference (p>0.05) in the antibacterial effect of CPB between gamma and non-gamma sterilization groups. FS presented no antibacterial activity. Gamma irradiation decreased the fluoride release of FS, but did not affect the antibacterial activity of the studied materials. PMID:19738944

  18. Natural sisal fibers derived hierarchical porous activated carbon as capacitive material in lithium ion capacitor

    NASA Astrophysics Data System (ADS)

    Yang, Zhewei; Guo, Huajun; Li, Xinhai; Wang, Zhixing; Yan, Zhiliang; Wang, Yansen

    2016-10-01

    Lithium-ion capacitor (LIC) is a novel advanced electrochemical energy storage (EES) system bridging gap between lithium ion battery (LIB) and electrochemical capacitor (ECC). In this work, we report that sisal fiber activated carbon (SFAC) was synthesized by hydrothermal treatment followed by KOH activation and served as capacitive material in LIC for the first time. Different particle structure, morphology, specific surface area and heteroatoms affected the electrochemical performance of as-prepared materials and corresponding LICs. When the mass ratio of KOH to char precursor was 2, hierarchical porous structured SFAC-2 was prepared and exhibited moderate specific capacitance (103 F g-1 at 0.1 A g-1), superior rate capability and cyclic stability (88% capacity retention after 5000 cycles at 1 A g-1). The corresponding assembled LIC (LIC-SC2) with optimal comprehensive electrochemical performance, displayed the energy density of 83 Wh kg-1, the power density of 5718 W kg-1 and superior cyclic stability (92% energy density retention after 1000 cycles at 0.5 A g-1). It is worthwhile that the source for activated carbon is a natural and renewable one and the synthesis method is eco-friendly, which facilitate that hierarchical porous activated carbon has potential applications in the field of LIC and other energy storage systems.

  19. Development of Pupils' Transfer Skills by Means of Hands On Activities with Artisan Materials in Natural Sciences Classes

    ERIC Educational Resources Information Center

    Ciascai, Liliana; Chicinas, Luminita

    2008-01-01

    Hands on activities with artisan materials used in order to realize different practical devices helpful in learning process are one of the most frequently used activity in science classes. Usually, the main strength of these activities are: a deeper learning, an increased motivation of pupils for actively learning and development of practical…

  20. Impact of Modifying Activity-Based Instructional Materials for Special Needs Students in Middle School Astronomy

    NASA Astrophysics Data System (ADS)

    Olsen, Julia K.; Slater, Timothy F.

    Middle school students who have special needs because they are learning disabled require targeted attention in our nation's pursuit of improved science achievement for all students. In early 2006, the Lawrence Hall of Science conducted a national field test of a newly developed GEMS (Great Explorations in Math and Science) space science curriculum package for middle school students. During this field testing, we modified a subset of the curriculum materials to reflect the principles of best practices in working with special needs students, specifically learning disabled students, in a subset of the field test classrooms to determine if these students scored differently on the assessments than students in the larger assessment database. Results suggest that many students, not just those with special needs, demonstrate achievement gains using instructional materials purposefully aligned with research- informed principles of best practices for special needs students.

  1. Partially Hydrogenated Graphene Materials Exhibit High Electrocatalytic Activities Related to Unintentional Doping with Metallic Impurities.

    PubMed

    Jankovský, Ondřej; Libánská, Alena; Bouša, Daniel; Sedmidubský, David; Matějková, Stanislava; Sofer, Zdeněk

    2016-06-13

    Partially hydrogenated graphene materials, synthesized by the chemical reduction/hydrogenation of two different graphene oxides using zinc powder in acidic environment or aluminum powder in alkaline environment, exhibit high electrocatalytic activities, as well as electrochemical sensing properties. The starting graphene oxides and the resultant hydrogenated graphenes were characterized in detail. Their electrocatalytic activity was examined in the oxygen reduction reaction, whereas sensing properties towards explosives were tested by using picric acid as a redox probe. Findings indicate that the high electrocatalytic performance originates not only from the hydrogenation of graphene, but also from unintentional contamination of graphene with manganese and other metals during synthesis. A careful evaluation of the obtained data and a detailed chemical analysis are necessary to identify the origin of this anomalous electrocatalytic activity. PMID:27167069

  2. Nomex-derived activated carbon fibers as electrode materials in carbon based supercapacitors

    NASA Astrophysics Data System (ADS)

    Leitner, K.; Lerf, A.; Winter, M.; Besenhard, J. O.; Villar-Rodil, S.; Suárez-García, F.; Martínez-Alonso, A.; Tascón, J. M. D.

    Electrochemical characterization has been carried out for electrodes prepared of several activated carbon fiber samples derived from poly (m-phenylene isophthalamide) (Nomex) in an aqueous solution. Depending on the burn-off due to activation the BET surface area of the carbons was in the order of 1300-2800 m 2 g -1, providing an extensive network of micropores. Their capability as active material for supercapacitors was evaluated by using cyclic voltammetry and impedance spectroscopy. Values for the capacitance of 175 F g -1 in sulfuric acid were obtained. Further on, it was observed that the specific capacitance and the performance of the electrode increase significantly with increasing burn-off degree. We believe that this fact can be attributed to the increase of surface area and porosity with increasing burn-off.

  3. Synthesis, characterization and catalytic activity of acid-base bifunctional materials through protection of amino groups

    SciTech Connect

    Shao, Yanqiu; Liu, Heng; Yu, Xiaofang; Guan, Jingqi; Kan, Qiubin

    2012-03-15

    Graphical abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. Highlights: Black-Right-Pointing-Pointer The acid-base bifunctional material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized through protection of amino groups. Black-Right-Pointing-Pointer The obtained bifunctional material was tested for aldol condensation. Black-Right-Pointing-Pointer The SO{sub 3}H-SBA-15-NH{sub 2} catalyst containing amine and sulfonic acid groups exhibited excellent acid-basic properties. -- Abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. X-ray diffraction (XRD), N{sub 2} adsorption-desorption, transmission electron micrographs (TEM), back titration, {sup 13}C magic-angle spinning (MAS) NMR and {sup 29}Si magic-angle spinning (MAS) NMR were employed to characterize the synthesized materials. The obtained bifunctional material was tested for aldol condensation reaction between acetone and 4-nitrobenzaldehyde. Compared with monofunctional catalysts of SO{sub 3}H-SBA-15 and SBA-15-NH{sub 2}, the bifunctional sample of SO{sub 3}H-SBA-15-NH{sub 2} containing amine and sulfonic acid groups exhibited excellent acid-basic properties, which make it possess high activity for the aldol condensation.

  4. Kraft lignin/silica-AgNPs as a functional material with antibacterial activity.

    PubMed

    Klapiszewski, Łukasz; Rzemieniecki, Tomasz; Krawczyk, Magdalena; Malina, Dagmara; Norman, Małgorzata; Zdarta, Jakub; Majchrzak, Izabela; Dobrowolska, Anna; Czaczyk, Katarzyna; Jesionowski, Teofil

    2015-10-01

    Advanced functional silica/lignin hybrid materials, modified with nanosilver, were obtained. The commercial silica Syloid 244 was used, modified with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to increase its chemical affinity to lignin. Similarly, kraft lignin was oxidized using a solution of sodium periodate to activate appropriate functional groups on its surface. Silver nanoparticles were grafted onto the resulting silica/lignin hybrids. The systems obtained were comprehensively tested using available techniques and methods, including transmission electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, elemental analysis and atomic absorption spectroscopy. An evaluation was also made of the electrokinetic stability of the systems with and without silver nanoparticles. Conclusions were drawn concerning the chemical nature of the bonds between the precursors and the effectiveness of the method of binding nanosilver to the hybrid materials. The antimicrobial activity of the studied materials was tested against five species of Gram-positive and Gram-negative bacteria. The addition of silver nanoparticles to the silica/lignin hybrids led to inhibition of the growth of the analyzed bacteria. The best results were obtained against Pseudomonas aeruginosa, a dangerous human pathogen.

  5. Towards multifunctional materials incorporating elastomers and reversible redox-active fragments.

    PubMed

    Tarrés, Màrius; Viñas, Clara; Cioran, Ana M; Hänninen, Mikko M; Sillanpää, Reijo; Teixidor, Francesc

    2014-11-24

    This paper presents a novel and unique feature of metallacarboranes, consisting of the linkage of this redox electro-active site to a stretchable polymer. This is based on polyTHF, a known and applied material. This hybrid material has the two ends functionalized: one with the aforementioned redox molecule and the other with a terminal OH group, both linked by a molecular spring. Moreover, the redox electro-active molecules can be synthesized with either cobalt (cobaltabisdicarbollide) or with iron (ferrabisdicarbollide), species whose respective E(1/2) value differs by almost 1 V. The polymerization mechanism, based on an intermediate molecular crystal structure, is explained through an unexpected cyclization process of the dioxanate derivative of the metallacarboranes with an additional THF molecule. This is achieved in the absence of any metal or external electrophile. Surface functionalization of a Pt electrode by the electropolymerization of pyrrole doped with the pristine metallacarboranes and with the polyTHF hybrid materials is reported in this paper.

  6. Synthesis of Iminodiacetate Functionalized Polypropylene Films and Their Efficacy as Antioxidant Active-Packaging Materials.

    PubMed

    Lin, Zhuangsheng; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2016-06-01

    The introduction of metal-chelating ligands to the food-contact surface of packaging materials may enable the removal of synthetic chelators (e.g., ethylenediamine tetra-acetic acid (EDTA)) from food products. In this study, the metal-chelating ligand iminodiacetate (IDA) was covalently grafted onto polypropylene surfaces to produce metal-chelating active-packaging films. The resulting films were able to chelate 138.1 ± 26 and 210.0 ± 28 nmol/cm(2) Fe(3+) and Cu(2+) ions, respectively, under acidic conditions (pH 3.0). The films demonstrated potent antioxidant efficacy in two model food systems. In an emulsified-oil system, the chelating materials extended the lag phase of both lipid hydroperoxide and hexanal formation from 5 to 25 days and were as effective as EDTA. The degradation half-life of ascorbic acid in an aqueous solution was extended from 5 to 14 days. This work demonstrates the potential application of surface-grafted chelating IDA ligands as effective antioxidant active food-packaging materials. PMID:27243793

  7. Studies on supercapacitor electrode material from activated lignin-derived mesoporous carbon.

    PubMed

    Saha, Dipendu; Li, Yunchao; Bi, Zhonghe; Chen, Jihua; Keum, Jong K; Hensley, Dale K; Grappe, Hippolyte A; Meyer, Harry M; Dai, Sheng; Paranthaman, M Parans; Naskar, A K

    2014-01-28

    We synthesized mesoporous carbon from pre-cross-linked lignin gel impregnated with a surfactant as the pore-forming agent and then activated the carbon through physical and chemical methods to obtain activated mesoporous carbon. The activated mesoporous carbons exhibited 1.5- to 6-fold increases in porosity with a maximum Brunauer-Emmett-Teller (BET) specific surface area of 1148 m(2)/g and a pore volume of 1.0 cm(3)/g. Both physical and chemical activation enhanced the mesoporosity along with significant microporosity. Plots of cyclic voltammetric data with the capacitor electrode made from these carbons showed an almost rectangular curve depicting the behavior of ideal double-layer capacitance. Although the pristine mesoporous carbon exhibited a range of surface-area-based capacitance similar to that of other known carbon-based supercapacitors, activation decreased the surface-area-based specific capacitance and enhanced the gravimetric specific capacitance of the mesoporous carbons. A vertical tail in the lower-frequency domain of the Nyquist plot provided additional evidence of good supercapacitor behavior for the activated mesoporous carbons. We have modeled the equivalent circuit of the Nyquist plot with the help of two constant phase elements (CPE). Our work demonstrated that biomass-derived mesoporous carbon materials continue to show potential for use in specific electrochemical applications.

  8. Evaluation of precision and accuracy of selenium measurements in biological materials using neutron activation analysis

    SciTech Connect

    Greenberg, R.R.

    1988-01-01

    In recent years, the accurate determination of selenium in biological materials has become increasingly important in view of the essential nature of this element for human nutrition and its possible role as a protective agent against cancer. Unfortunately, the accurate determination of selenium in biological materials is often difficult for most analytical techniques for a variety of reasons, including interferences, complicated selenium chemistry due to the presence of this element in multiple oxidation states and in a variety of different organic species, stability and resistance to destruction of some of these organo-selenium species during acid dissolution, volatility of some selenium compounds, and potential for contamination. Neutron activation analysis (NAA) can be one of the best analytical techniques for selenium determinations in biological materials for a number of reasons. Currently, precision at the 1% level (1s) and overall accuracy at the 1 to 2% level (95% confidence interval) can be attained at the U.S. National Bureau of Standards (NBS) for selenium determinations in biological materials when counting statistics are not limiting (using the {sup 75}Se isotope). An example of this level of precision and accuracy is summarized. Achieving this level of accuracy, however, requires strict attention to all sources of systematic error. Precise and accurate results can also be obtained after radiochemical separations.

  9. Effect of atmospheric interference and sensor noise in retrieval of optically active materials in the ocean by hyperspectral remote sensing.

    PubMed

    Levin, Iosif M; Levina, Elizaveta

    2007-10-01

    We present a method to construct the best linear estimate of optically active material concentration from ocean radiance spectra measured through an arbitrary atmosphere layer by a hyperspectral sensor. The algorithm accounts for sensor noise. Optical models of seawater and maritime atmosphere were used to obtain the joint distribution of spectra and concentrations required for the algorithm. The accuracy of phytoplankton retrieval is shown to be substantially lower than that of sediment and dissolved matter. In all cases, the sensor noise noticeably reduces the retrieval accuracy. Additional errors due to atmospheric interference are analyzed, and possible ways to increase the accuracy of retrieval are suggested, such as changing sensor parameters and including a priori information about observation conditions.

  10. Vocabulary Roulette (Open to Suggestion).

    ERIC Educational Resources Information Center

    Rinehart, Marilyn

    1990-01-01

    Describes an activity in which students learn new words by guessing the meaning in isolation, in context, and then by looking in a dictionary. Notes that the pressure on students to be correct is removed by having different students guess the meaning at each stage of the activity. (RS)

  11. Multifunctional radical-doped polyoxometalate-based host-guest material: photochromism and photocatalytic activity.

    PubMed

    Liao, Jian-Zhen; Zhang, Hai-Long; Wang, Sa-Sa; Yong, Jian-Ping; Wu, Xiao-Yuan; Yu, Rongmin; Lu, Can-Zhong

    2015-05-01

    An effective strategy to synthesize multifunctional materials is the incorporation of functional organic moieties and metal oxide clusters via self-assembly. A rare multifunctional radical-doped zinc-based host-guest crystalline material was synthesized with a fast-responsive reversible ultraviolet visible light photochromism, photocontrolled tunable luminescence, and highly selective photocatalytic oxidation of benzylic alcohols as a result of blending of distinctively different functional components, naphthalenediimide tectons, and polyoxometalates (POMs). It is highly unique to link π-electron-deficient organic tectons and POMs by unusual POMs anion-π interactions, which are not only conducive to keeping the independence of each component but also effectively promoting the charge transfer or exchange among the components to realize the fast-responsive photochromism, photocontrolled tunable luminescence, and photocatalytic activity.

  12. Analysis of marine sediment and lobster hepatopancreas reference materials by instrumental photon activation

    SciTech Connect

    Landsberger, S.; Davidson, W.F.

    1985-01-01

    By use of instrumental photon activation analysis, twelve trace (As, Ba, Cr, Co, Mn, Ni, Pb, Sb, Sr, U, Zn, and Zr) and eight minor (C, Na, Mg, Co, K, Ca, Tl, and Fe) elements were determined in a certified marine sediment standard reference material as well as eight trace (Mn, Ni, Cu, Zn, As, Sr, Cd, and Pb) and four minor (Na, Mg, Cl, and Ca) elements in a certified marine tissue (lobster hepatopancreas) standard reference material. The precision and accuracy of the present results when compared to the accepted values clearly demonstrate the reliability of this nondestructive technique and its applicability to marine environmental or marine geochemical studies. 24 references, 4 figures, 3 tables.

  13. Removal of Basic Violet 14 from aqueous solution using sulphuric acid activated materials.

    PubMed

    Suresh, S

    2016-01-01

    In this study the adsorption of Basic Violet, 14 from aqueous solution onto sulphuric acid activated materials prepared from Calophyllum inophyllum (CS) and Theobroma cacao (TS) shells were investigated. The experimental data were analysed by Langmuir, Freundlich and Temkin isotherm models. The results showed that CS has a superior adsorption capacity compared to the TS. The adsorption capacity was found to be 1416.43 mg/g for CS and 980.39 mg/g for TS. The kinetic data results at different concentrations were analysed using pseudo first-order and pseudo-second order model. Boyd plot indicates that the dye adsorption onto CS and TS is controlled by film diffusion. The adsorbents were characterised by scanning electron microscopy. The materials used in this study were economical waste products and hence can be an attractive alternative to costlier adsorbents for dye removal in industrial wastewater treatment processes. PMID:27330899

  14. Multifunctional radical-doped polyoxometalate-based host-guest material: photochromism and photocatalytic activity.

    PubMed

    Liao, Jian-Zhen; Zhang, Hai-Long; Wang, Sa-Sa; Yong, Jian-Ping; Wu, Xiao-Yuan; Yu, Rongmin; Lu, Can-Zhong

    2015-05-01

    An effective strategy to synthesize multifunctional materials is the incorporation of functional organic moieties and metal oxide clusters via self-assembly. A rare multifunctional radical-doped zinc-based host-guest crystalline material was synthesized with a fast-responsive reversible ultraviolet visible light photochromism, photocontrolled tunable luminescence, and highly selective photocatalytic oxidation of benzylic alcohols as a result of blending of distinctively different functional components, naphthalenediimide tectons, and polyoxometalates (POMs). It is highly unique to link π-electron-deficient organic tectons and POMs by unusual POMs anion-π interactions, which are not only conducive to keeping the independence of each component but also effectively promoting the charge transfer or exchange among the components to realize the fast-responsive photochromism, photocontrolled tunable luminescence, and photocatalytic activity. PMID:25859742

  15. Prompt gamma activation analysis of boron in reference materials using diffracted polychromatic neutron beam

    NASA Astrophysics Data System (ADS)

    Byun, S. H.; Sun, G. M.; Choi, H. D.

    2004-01-01

    Boron concentrations were analyzed for standard reference materials by prompt gamma activation analysis (PGAA). The measurements were performed at the SNU-KAERI PGAA facility installed at Hanaro, the research reactor of Korea Atomic Energy Research Institute (KAERI). The facility uses a diffracted polychromatic beam with a neutron flux of 7.9 × 10 7 n/cm 2 s. Elemental sensitivity for boron was calibrated from the prompt gamma-ray spectra of boric acid samples containing 2-45 μg boron. The sensitivity of 2131 cps/mg-B was obtained from the linearity of the boron peak count rate versus the boron mass. The detection limit for boron was estimated to be 67 ng from an empty sample bag spectrum for a counting time of 10,000 s. The measured boron concentrations for standard reference materials showed good consistency with the certified or information values.

  16. Use of electrochemically activated aqueous solutions in the manufacture of fur materials.

    PubMed

    Danylkovych, Anatoliy G; Lishchuk, Viktor I; Romaniuk, Oksana O

    2016-01-01

    The influence of characteristics of electrochemically activated aqueous processing mediums in the treatment of fur skins with different contents of fatty substances was investigated. The use of electroactive water, namely anolytes and catholytes, forgoing antiseptics or surface-active materials, helped to restore the hydration of fur skins and to remove from them soluble proteins, carbohydrates and fatty substances. The activating effect of anolyte and catholyte in solutions of water on the processes of treating raw furs is explained by their special physical and chemical properties, namely the presence of free radicals, ions and molecules of water which easily penetrate cells' membranes and into the structure of non-collagen components and microfiber structure of dermic collagen. The stage of lengthy acid and salt treatment is excluded from the technical treatment as a result of using electroactivated water with high oxidizing power. A low-cost technology of processing different kinds of fur with the use of electroactivated water provides for substantial economy of water and chemical reagents, a two to threefold acceleration of the soaking and tanning processes and creation of highly elastic fur materials with a specified set of physical and chemical properties. At the same time the technology of preparatory processes of fur treatment excludes the use of such toxic antiseptics as formalin and sodium silicofluoride, which gives grounds to regard it as ecologically safe.

  17. An active thermography approach for thermal and electrical characterization of thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Streza, M.; Longuemart, S.; Guilmeau, E.; Strzalkowski, K.; Touati, K.; Depriester, M.; Maignan, A.; Sahraoui, A. Hadj

    2016-07-01

    The enhancement of figure of merit (ZT) of thermoelectrics is becoming extremely important for an efficient conversion of thermal energy into electrical energy. In this respect, reliable measurements of thermal and electrical parameters are of paramount importance in order to characterize thermoelectric materials in terms of their efficiency. In this work, a combined theoretical-experimental active thermography approach is presented. The method consists of selecting the right sequential interdependence between the excitation frequency and the sampling rate of the infrared camera, by computing a temporal Fourier analysis of each pixel of the recorded IR image. The method is validated by using a reference sample which is then applied to a recent synthesized titanium trisulphide thermoelectric material (TiS3). By combining AC and steady-state experiments, one can obtain information on both thermal and electrical parameters of TE materials (namely thermal diffusivity, Seebeck coefficient). The thermal diffusivity and thermal conductivity of TiS3 are also measured using photothermal radiometry technique (PTR) and the resulting values of these parameters are α  =  9.7*10-7 m2 s-1 and k  =  2.2 W m-1 K, respectively. The results obtained with the two techniques are in good agreement. In the case of TE materials, the main benefit of the proposed method is related to its non-contact nature and the possibility of obtaining the electric potential and temperature at the same probes. The Seebeck coefficient obtained by active IR thermography (S  =  -554 μV K-1) is consistent with the one obtained using an ULVAC-ZEM3 system (S  =  -570 μV K-1). For a large number of users of thermographic cameras, which are not equipped with a lock-in thermography module, the present approach provides an affordable and cheaper solution.

  18. An active thermography approach for thermal and electrical characterization of thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Streza, M.; Longuemart, S.; Guilmeau, E.; Strzalkowski, K.; Touati, K.; Depriester, M.; Maignan, A.; Sahraoui, A. Hadj

    2016-07-01

    The enhancement of figure of merit (ZT) of thermoelectrics is becoming extremely important for an efficient conversion of thermal energy into electrical energy. In this respect, reliable measurements of thermal and electrical parameters are of paramount importance in order to characterize thermoelectric materials in terms of their efficiency. In this work, a combined theoretical-experimental active thermography approach is presented. The method consists of selecting the right sequential interdependence between the excitation frequency and the sampling rate of the infrared camera, by computing a temporal Fourier analysis of each pixel of the recorded IR image. The method is validated by using a reference sample which is then applied to a recent synthesized titanium trisulphide thermoelectric material (TiS3). By combining AC and steady-state experiments, one can obtain information on both thermal and electrical parameters of TE materials (namely thermal diffusivity, Seebeck coefficient). The thermal diffusivity and thermal conductivity of TiS3 are also measured using photothermal radiometry technique (PTR) and the resulting values of these parameters are α  =  9.7*10‑7 m2 s‑1 and k  =  2.2 W m‑1 K, respectively. The results obtained with the two techniques are in good agreement. In the case of TE materials, the main benefit of the proposed method is related to its non-contact nature and the possibility of obtaining the electric potential and temperature at the same probes. The Seebeck coefficient obtained by active IR thermography (S  =  ‑554 μV K‑1) is consistent with the one obtained using an ULVAC-ZEM3 system (S  =  ‑570 μV K‑1). For a large number of users of thermographic cameras, which are not equipped with a lock-in thermography module, the present approach provides an affordable and cheaper solution.

  19. The Astronomy Workshop: Computer Assisted Learning Tools with Instructor Support Materials and Student Activities

    NASA Astrophysics Data System (ADS)

    Deming, Grace; Hamilton, D.; Hayes-Gehrke, M.

    2006-12-01

    The Astronomy Workshop (http://janus.astro.umd.edu) is a collection of interactive World Wide Web tools that were developed under the direction of Doug Hamilton for use in undergraduate classes, as supplementary materials appropriate for grades 9-12, and by the general public. The philosophy of the website is to foster student and public interest in astronomy by capitalizing on their fascination with computers and the internet. Many of the tools were developed by graduate and undergraduate students at UMD. This website contains over 20 tools on topics including scientific notation, giant impacts, extrasolar planets, astronomical distances, planets, moons, comets, and asteroids. Educators around the country at universities, colleges, and secondary schools have used the Astronomy Workshop’s tools and activities as homework assignments, in-class demos, or extra credit. Since 2005, Grace Deming has assessed several of the Astronomy Workshop’s tools for clarity and effectiveness by interviewing students as they used tools on the website. Based on these interviews, Deming wrote student activities and instructor support materials and posted them to the website. Over the next three years, we will continue to interview students, develop web materials, and field-test activities. We are targeting classes in introductory undergraduate astronomy courses and grades 11-12 for our Spring 2007 field tests. We are interested in hearing your ideas on how we can make the Astronomy Workshop more appealing to educators, museum directors, specialty programs, and professors. This research is funded by NASA EPO grants NNG04GM18G and NNG06GGF99G.

  20. Laminin chain expression suggests that laminin-10 is a major isoform in the mouse hippocampus and is degraded by the tissue plasminogen activator/plasmin protease cascade during excitotoxic injury.

    PubMed

    Indyk, J A; Chen, Z L; Tsirka, S E; Strickland, S

    2003-01-01

    Laminins are important components of the extracellular matrix, and participate in neuronal development, survival and regeneration. The tissue plasminogen activator/plasmin extracellular protease cascade and downstream laminin degradation are implicated in excitotoxin-induced neuronal degeneration. To determine which specific laminin chains are involved, we investigated the expression of laminins in the hippocampus, and the cell types expressing them. Reverse transcription-PCR demonstrated that the messenger RNAs for all laminin chains could be detected in the hippocampus. To determine the localization of laminin chain expression, immunostaining was used. This method showed that alpha5, beta1 and gamma1 are most highly expressed in the neuronal cell layers. Immunoblotting confirmed the hippocampal expression of the chains alpha5, beta1 and gamma1, and RNA in situ hybridization showed a neuronal expression pattern of alpha5, beta1 and gamma1. At early time points following intrahippocampal injection of kainate, alpha5, beta1 and gamma1 chain immunoreactivities were lost. In addition, tissue plasminogen activator-deficient mice, which are resistant to kainate-induced neuronal death, show no significant change in laminins alpha5, beta1 and gamma1 after intrahippocampal kainate injection. Taken together, these results suggest that laminin-10 (alpha5-beta1-gamma1) comprises a major neuronal laminin in the mouse hippocampus, and is degraded before neuronal death during excitotoxic injury by the tissue plasminogen activator/plasmin protease cascade. By identifying a neuronal laminin (laminin-10) that participates in neuronal degeneration after excitotoxic injury, this study clarifies the molecular definition of the extracellular matrix in the hippocampus and further defines a pathway for mechanisms of neuronal death.

  1. Optimizing vermistabilization of waste activated sludge using vermicompost as bulking material.

    PubMed

    Hait, Subrata; Tare, Vinod

    2011-03-01

    An integrated composting-vermicomposting system has been developed for stabilization of waste activated sludge (WAS) using matured vermicompost as bulking material and Eisenia fetida as earthworm species. Composting was considered as the main processing unit and vermicomposting as polishing unit. The integrated system was optimized by successive recycling and mixing of bulking material with WAS during composting and examining the effects of environmental condition (i.e. temperature: 10-30°C and relative humidity: 50 and 90%) and stocking density (0-5 kg/m(2)) on vermicomposting. The composting stage resulted in sufficient enrichment of bulking material with organic matter after 20 cycles of recycling and mixing with WAS and produced materials acceptable for vermicomposting. Vermicomposting of composted material caused significant reduction in pH, volatile solids (VS), specific oxygen uptake rate (SOUR), total carbon (TC), total organic carbon (TOC), C/N ratio and pathogens and a substantial increase in electrical conductivity (EC), total nitrogen (TN) and total phosphorous (TP). The environmental conditions (i.e. temperature: 10-30°C and relative humidity: 50 and 90%) and stocking density (0-5 kg/m(2)) have profound effects on vermicomposting. Temperature of 20°C with high humidity is the best suited environmental condition for vermicomposting employing E. fetida. The favorable stocking density range for vermiculture is 0.5-2.0 kg/m(2) (optimum: 0.5 kg/m(2)) and for vermicomposting is 2.0-4.0 kg/m(2) (optimum: 3.0 kg/m(2)), respectively. The integrated composting-vermicomposting system potentially stabilizes and converts the hazardous WAS into quality organic manure for agronomic applications without any adverse effects.

  2. Activated carbon made from cow dung as electrode material for electrochemical double layer capacitor

    NASA Astrophysics Data System (ADS)

    Bhattacharjya, Dhrubajyoti; Yu, Jong-Sung

    2014-09-01

    Cow dung is one of the most abundant wastes generated on earth and has been traditionally used as fertilizer and fuel in most of the developing countries. In this study activated carbon is synthesized from cow dung by a modified chemical activation method, where partially carbonized cow dung is treated with KOH in different ratio. The synthesized activated carbon possesses irregular surface morphology with high surface area in the range of 1500-2000 m2 g-1 with proper amount of micropore and mesopore volume. In particular, we demonstrate that the surface morphology and porosity parameters change with increase in KOH ratio. These activated carbons are tested as electrode material in two-electrode symmetric supercapacitor system in non-aqueous electrolyte and found to exhibit high specific capacitance with excellent retention of it at high current density and for long term operation. In particular, the activated carbon synthesized at 2:1 ratio of KOH and the pre-carbonized char shows the best performance with specific capacitance of 124 F g-1 at 0.1 A g-1 and retains up to 117 F g-1 at 1.0 A g-1 current density. The performance is attributed to high surface area along with optimum amount of micropore and mesopore volume.

  3. A history of semi-active laser dome and window materials

    NASA Astrophysics Data System (ADS)

    Sullivan, Roger M.

    2014-05-01

    Semi-Active Laser (SAL) guidance systems were developed starting in the mid-1960's and today form an important class of precision guided weapons. The laser wavelengths generally fall in the short wave infrared region of the spectrum. Relative to passive, image based, infrared seekers the optical demands placed on the domes or windows of SAL seekers is very modest, allowing the use of low cost, easily manufactured materials, such as polycarbonate. This paper will examine the transition of SAL window and dome science and technology from the laboratory to battlefield, with special emphasis on the story of polycarbonate domes.

  4. Magnesium as Novel Material for Active Plasmonics in the Visible Wavelength Range.

    PubMed

    Sterl, Florian; Strohfeldt, Nikolai; Walter, Ramon; Griessen, Ronald; Tittl, Andreas; Giessen, Harald

    2015-12-01

    Investigating new materials plays an important role for advancing the field of nanoplasmonics. In this work, we fabricate nanodisks from magnesium and demonstrate tuning of their plasmon resonance throughout the whole visible wavelength range by changing the disk diameter. Furthermore, we employ a catalytic palladium cap layer to transform the metallic Mg particles into dielectric MgH2 particles when exposed to hydrogen gas. We prove that this transition can be reversed in the presence of oxygen. This yields plasmonic nanostructures with an extinction spectrum that can be repeatedly switched on or off or kept at any intermediate state, offering new perspectives for active plasmonic metamaterials.

  5. Impact of the excitation source and plasmonic material on cylindrical active coated nano-particles.

    PubMed

    Arslanagic, Samel; Liu, Yan; Malureanu, Radu; Ziolkowski, Richard W

    2011-01-01

    Electromagnetic properties of cylindrical active coated nano-particles comprised of a silica nano-cylinder core layered with a plasmonic concentric nano-shell are investigated for potential nano-sensor applications. Particular attention is devoted to the near-field properties of these particles, as well as to their far-field radiation characteristics, in the presence of an electric or a magnetic line source. A constant frequency canonical gain model is used to account for the gain introduced in the dielectric part of the nano-particle, whereas three different plasmonic materials (silver, gold, and copper) are employed and compared for the nano-shell layers.

  6. Berstein's anti-reductionistic materialism: On the road towards a biology of activity (1965).

    PubMed

    Bongaardt, R; Pickenhain, L; Meijer, O G

    2000-10-01

    Bernstein's paper, "On the Road Towards a Biology of Activity," appeared the year before his death.2 With this paper, Bernstein closed several lines of argument that he had been developing from the onset of his career in the early 1920s. The paper converges on the notion of activity. In accordance with his own shifting focus heuristic (cf. Bongaardt, 1996), Bernstein challenged future researchers of movement to integrate models of the movement functions that constitute activity. He suggested that these functions are: the coordination of movement, the planning of movement, and the exploration of better, optimal ways to move. In the 1920s, Bernstein had collaborated with his friend and colleague L.S. Vygotsky at the Moscow Institute of Experimental Psychology. Vygotsky (cf. 1926/1994) was the first to place activity at the core of Soviet psychology. According to Vygotsky, reflexology and behaviorism, then dominant approaches in psychology, were fundamentally wrong; they focus on building-blocks of behavior without addressing phenomena that stand out as typically human, most importantly, consciousness. Rather than starting with building blocks, psychology should start with the daily activity of human beings in their environment and show how this activity relates to consciousness. Forty years later, in his 1965 paper, Bernstein stressed a point that mirrors Vygotsky's: Reflexes are not building blocks of movement. The general characteristics of any movement precede the specificity of such units, whether reflexes or synergies, and this primacy pertains to the actual organization of movements as well as to the study of movement. The development and relevance of the activity concept in Bernstein's work in the period from 1925 to 1965 deserves a study of its own; here, a brief historical sketch of Bernstein's activity concept is offered, along with a few theoretical considerations concerning activity's constituent functions. PMID:11020671

  7. Quantitative structure-activity relationship modelling of oral acute toxicity and cytotoxic activity of fragrance materials in rodents.

    PubMed

    Papa, E; Luini, M; Gramatica, P

    2009-10-01

    Fragrance materials are used as ingredients in many consumer and personal care products. The wide and daily use of these substances, as well as their mainly uncontrolled discharge through domestic sewage, make fragrance materials both potential indoor and outdoor air pollutants which are also connected to possible toxic effects on humans (asthma, allergies, headaches). Unfortunately, little is known about the environmental fate and toxicity of these substances. However, the use of alternative, predictive approaches, such as quantitative structure-activity relationships (QSARs), can help in filling the data gap and in the characterization of the environmental and toxicological profile of these substances. In the proposed study, ordinary least squares regression-based QSAR models were developed for three toxicological endpoints: mouse oral LD(50), inhibition of NADH-oxidase (EC(50) NADH-Ox) and the effect on mitochondrial membrane potential (EC(50) DeltaPsim). Theoretical molecular descriptors were calculated by using DRAGON software, and the best QSAR models were developed according to the principles defined by the Organization for Economic Co-operation and Development.

  8. Material composition assessment and discovering sublimation activity on asteroids 145 Adeona, 704 Interamnia, 779 Nina, and 1474 Beira

    NASA Astrophysics Data System (ADS)

    Busarev, V. V.; Barabanov, S. I.; Puzin, V. B.

    2016-07-01

    Spectrophotometric observations of 145 Adeona, 704 Interamnia, 779 Nina, and 1474 Beira—asteroids of close primitive types—allowed us to detect similar mineralogical absorption bands in their reflectance spectra centered in the range 0.35 to 0.92 μm; the bands are at 0.38, 0.44, and 0.67-0.71 μm. On the same asteroids, the spectral signs of simultaneous sublimation activity were found for the first time. Namely, there are maxima at ˜0.35-0.60 μm in the reflectance spectra of Adeona, Interamnia, and Nina and at ˜0.55-075 μm in the spectra of Beira. We connect this activity with small heliocentric distances of the asteroids and, consequently, with a high insolation at their surfaces. Examination of the samples of probable analogues allowed us to identify Fe3+ and Fe2+ in the material of these asteroids through the mentioned absorption bands. For analogues, we took powdered samples of carbonaceous chondrites Orgueil (CI), Mighei (CM2), Murchison (CM2), and Boriskino (CM2), as well as hydrosilicates of the serpentine group. Laboratory spectral reflectance study of the samples of low-iron Mg serpentines (<2 wt % FeO) showed that the equivalent width of the absorption band centered at 0.44-0.46 μm strongly correlates with the content of Fe3+ in octahedral and tetrahedral coordinations. Our conclusion is that this absorption band can be used as a qualitative indicator of Fe3+ in the surface matter of asteroids and other solid celestial bodies. The comparison of the listed analog samples and the asteroids by parameters of the spectral features suggests that the silicate component of the asteroids' surface material is a mixture of hydrated and oxidized compounds, including oxides and hydroxides of bivalent and trivalent iron and carbonaceous-chondritic material. At the same time, the sublimation activity of Adeona, Interamnia, Nina, and Beira at high surface temperatures points to a substantial content of water ice in their material. This contradicts the

  9. 10 Suggestions for Enhancing Lecturing

    ERIC Educational Resources Information Center

    Heitzmann, Ray

    2010-01-01

    Criticism of the lecture method remains a staple of discussion and writing in academia--and most of the time it's deserved! Those interested in improving this aspect of their teaching might wish to consider some or all of the following suggestions for enhancing lectures. These include: (1) Lectures must start with a "grabber"; (2) Lectures must be…

  10. Models: Caveats, Reflections, and Suggestions

    ERIC Educational Resources Information Center

    Kirschling, Wayne R.

    1976-01-01

    Noting that mathematical modeling is a relatively new phenomenon in higher education and that much can be learned from the misdirections and mistakes that characterize modeling in general, the author describes major criticisms of modeling and suggests improvements, particularly in communication between modelers and potential model users. (JT)

  11. Low-background instrumental neutron activation analysis of silicon semiconductor materials

    SciTech Connect

    Smith, A.R.; McDonald, R.J.; Manini, H.; Hurley, D.L.; Norman, E.B.; Vella, M.C.; Odom, R.W.

    1996-01-01

    Samples of silicon wafers, some implanted with zinc, some with memory circuits fabricated on them, and some with oxide coatings were activated with neutrons and analyzed for trace element impurities with low-background germanium gamma-ray spectrometers. Results are presented for these samples as well as for a reference material. Because the silicon matrix activation is so small, reduced spectrometer system background permits the detection of significantly lower impurity concentrations than would otherwise be possible. For the highest efficiency and lowest background system, limits on the lowest levels of trace element concentrations have been measured for wafer sized (1 to 10 g) samples and inferred for bulk sized (365 g) samples. For wafer-sized samples, part-per-trillion detection capabilities are demonstrated for a variety of elemental contaminants important in semiconductor fabrication.

  12. SOME SUGGESTED GUIDLINES FOR WRITING MATERIALS FOR THE DISADVANTAGED.

    ERIC Educational Resources Information Center

    OLSEN, JAMES

    GUIDELINES FOR WRITING DIRECTIONS AND FOR WRITING EXERCISES FOR THE DISADVANTAGED WHO ARE ON THE LOWEST READING LEVEL ARE PRESENTED. SENTENCE AND LANGUAGE STUCTURE SHOULD BE SIMPLE, BRIEF, AND CONVERSATIONAL. DIRECTIONS SHOULD BE CONSIDERED A PART OF THE TEXT AND SHOULD BE ON THE SAME READING LEVEL. DIRECTIONS SHOULD BE CONSIDERED A PART OF THE…

  13. TAL effectors and activation of predicted host targets distinguish Asian from African strains of the rice pathogen Xanthomonas oryzae pv. oryzicola while strict conservation suggests universal importance of five TAL effectors

    PubMed Central

    Wilkins, Katherine E.; Booher, Nicholas J.; Wang, Li; Bogdanove, Adam J.

    2015-01-01

    Xanthomonas oryzae pv. oryzicola (Xoc) causes the increasingly important disease bacterial leaf streak of rice (BLS) in part by type III delivery of repeat-rich transcription activator-like (TAL) effectors to upregulate host susceptibility genes. By pathogen whole genome, single molecule, real-time sequencing and host RNA sequencing, we compared TAL effector content and rice transcriptional responses across 10 geographically diverse Xoc strains. TAL effector content is surprisingly conserved overall, yet distinguishes Asian from African isolates. Five TAL effectors are conserved across all strains. In a prior laboratory assay in rice cv. Nipponbare, only two contributed to virulence in strain BLS256 but the strict conservation indicates all five may be important, in different rice genotypes or in the field. Concatenated and aligned, TAL effector content across strains largely reflects relationships based on housekeeping genes, suggesting predominantly vertical transmission. Rice transcriptional responses did not reflect these relationships, and on average, only 28% of genes upregulated and 22% of genes downregulated by a strain are up- and down- regulated (respectively) by all strains. However, when only known TAL effector targets were considered, the relationships resembled those of the TAL effectors. Toward identifying new targets, we used the TAL effector-DNA recognition code to predict effector binding elements in promoters of genes upregulated by each strain, but found that for every strain, all upregulated genes had at least one. Filtering with a classifier we developed previously decreases the number of predicted binding elements across the genome, suggesting that it may reduce false positives among upregulated genes. Applying this filter and eliminating genes for which upregulation did not strictly correlate with presence of the corresponding TAL effector, we generated testable numbers of candidate targets for four of the five strictly conserved TAL

  14. Characterizing proton-activated materials to develop PET-mediated proton range verification markers

    NASA Astrophysics Data System (ADS)

    Cho, Jongmin; Ibbott, Geoffrey S.; Kerr, Matthew D.; Amos, Richard A.; Stingo, Francesco C.; Marom, Edith M.; Truong, Mylene T.; Palacio, Diana M.; Betancourt, Sonia L.; Erasmus, Jeremy J.; DeGroot, Patricia M.; Carter, Brett W.; Gladish, Gregory W.; Sabloff, Bradley S.; Benveniste, Marcelo F.; Godoy, Myrna C.; Patil, Shekhar; Sorensen, James; Mawlawi, Osama R.

    2016-06-01

    Conventional proton beam range verification using positron emission tomography (PET) relies on tissue activation alone and therefore requires particle therapy PET whose installation can represent a large financial burden for many centers. Previously, we showed the feasibility of developing patient implantable markers using high proton cross-section materials (18O, Cu, and 68Zn) for in vivo proton range verification using conventional PET scanners. In this technical note, we characterize those materials to test their usability in more clinically relevant conditions. Two phantoms made of low-density balsa wood (~0.1 g cm‑3) and beef (~1.0 g cm‑3) were embedded with Cu or 68Zn foils of several volumes (10–50 mm3). The metal foils were positioned at several depths in the dose fall-off region, which had been determined from our previous study. The phantoms were then irradiated with different proton doses (1–5 Gy). After irradiation, the phantoms with the embedded foils were moved to a diagnostic PET scanner and imaged. The acquired data were reconstructed with 20–40 min of scan time using various delay times (30–150 min) to determine the maximum contrast-to-noise ratio. The resultant PET/computed tomography (CT) fusion images of the activated foils were then examined and the foils’ PET signal strength/visibility was scored on a 5 point scale by 13 radiologists experienced in nuclear medicine. For both phantoms, the visibility of activated foils increased in proportion to the foil volume, dose, and PET scan time. A linear model was constructed with visibility scores as the response variable and all other factors (marker material, phantom material, dose, and PET scan time) as covariates. Using the linear model, volumes of foils that provided adequate visibility (score 3) were determined for each dose and PET scan time. The foil volumes that were determined will be used as a guideline in developing practical implantable markers.

  15. Characterizing proton-activated materials to develop PET-mediated proton range verification markers.

    PubMed

    Cho, Jongmin; Ibbott, Geoffrey S; Kerr, Matthew D; Amos, Richard A; Stingo, Francesco C; Marom, Edith M; Truong, Mylene T; Palacio, Diana M; Betancourt, Sonia L; Erasmus, Jeremy J; DeGroot, Patricia M; Carter, Brett W; Gladish, Gregory W; Sabloff, Bradley S; Benveniste, Marcelo F; Godoy, Myrna C; Patil, Shekhar; Sorensen, James; Mawlawi, Osama R

    2016-06-01

    Conventional proton beam range verification using positron emission tomography (PET) relies on tissue activation alone and therefore requires particle therapy PET whose installation can represent a large financial burden for many centers. Previously, we showed the feasibility of developing patient implantable markers using high proton cross-section materials ((18)O, Cu, and (68)Zn) for in vivo proton range verification using conventional PET scanners. In this technical note, we characterize those materials to test their usability in more clinically relevant conditions. Two phantoms made of low-density balsa wood (~0.1 g cm(-3)) and beef (~1.0 g cm(-3)) were embedded with Cu or (68)Zn foils of several volumes (10-50 mm(3)). The metal foils were positioned at several depths in the dose fall-off region, which had been determined from our previous study. The phantoms were then irradiated with different proton doses (1-5 Gy). After irradiation, the phantoms with the embedded foils were moved to a diagnostic PET scanner and imaged. The acquired data were reconstructed with 20-40 min of scan time using various delay times (30-150 min) to determine the maximum contrast-to-noise ratio. The resultant PET/computed tomography (CT) fusion images of the activated foils were then examined and the foils' PET signal strength/visibility was scored on a 5 point scale by 13 radiologists experienced in nuclear medicine. For both phantoms, the visibility of activated foils increased in proportion to the foil volume, dose, and PET scan time. A linear model was constructed with visibility scores as the response variable and all other factors (marker material, phantom material, dose, and PET scan time) as covariates. Using the linear model, volumes of foils that provided adequate visibility (score 3) were determined for each dose and PET scan time. The foil volumes that were determined will be used as a guideline in developing practical implantable markers. PMID:27203621

  16. Characterizing proton-activated materials to develop PET-mediated proton range verification markers

    NASA Astrophysics Data System (ADS)

    Cho, Jongmin; Ibbott, Geoffrey S.; Kerr, Matthew D.; Amos, Richard A.; Stingo, Francesco C.; Marom, Edith M.; Truong, Mylene T.; Palacio, Diana M.; Betancourt, Sonia L.; Erasmus, Jeremy J.; DeGroot, Patricia M.; Carter, Brett W.; Gladish, Gregory W.; Sabloff, Bradley S.; Benveniste, Marcelo F.; Godoy, Myrna C.; Patil, Shekhar; Sorensen, James; Mawlawi, Osama R.

    2016-06-01

    Conventional proton beam range verification using positron emission tomography (PET) relies on tissue activation alone and therefore requires particle therapy PET whose installation can represent a large financial burden for many centers. Previously, we showed the feasibility of developing patient implantable markers using high proton cross-section materials (18O, Cu, and 68Zn) for in vivo proton range verification using conventional PET scanners. In this technical note, we characterize those materials to test their usability in more clinically relevant conditions. Two phantoms made of low-density balsa wood (~0.1 g cm-3) and beef (~1.0 g cm-3) were embedded with Cu or 68Zn foils of several volumes (10-50 mm3). The metal foils were positioned at several depths in the dose fall-off region, which had been determined from our previous study. The phantoms were then irradiated with different proton doses (1-5 Gy). After irradiation, the phantoms with the embedded foils were moved to a diagnostic PET scanner and imaged. The acquired data were reconstructed with 20-40 min of scan time using various delay times (30-150 min) to determine the maximum contrast-to-noise ratio. The resultant PET/computed tomography (CT) fusion images of the activated foils were then examined and the foils’ PET signal strength/visibility was scored on a 5 point scale by 13 radiologists experienced in nuclear medicine. For both phantoms, the visibility of activated foils increased in proportion to the foil volume, dose, and PET scan time. A linear model was constructed with visibility scores as the response variable and all other factors (marker material, phantom material, dose, and PET scan time) as covariates. Using the linear model, volumes of foils that provided adequate visibility (score 3) were determined for each dose and PET scan time. The foil volumes that were determined will be used as a guideline in developing practical implantable markers.

  17. Special Form Testing of Sealed Source Encapsulation for High-Alpha-Activity Actinide Materials

    SciTech Connect

    Martinez, Oscar A

    2016-01-01

    In the United States all transportation of radioactive material is regulated by the U.S. Department of Transportation (DOT). Beginning in 2008 a new type of sealed-source encapsulation package was developed and tested by Oak Ridge National Laboratory (ORNL). These packages contain high-alpha-activity actinides and are regulated and transported in accordance with the requirements for DOT Class 7 hazardous material. The DOT provides specific regulations pertaining to special form encapsulation designs. The special form designation indicates that the encapsulated radioactive contents have a very low probability of dispersion even when subjected to significant structural events. The special form designs have been shown to simplify the delivery, transport, acceptance, and receipt processes. It is intended for these sealed-source encapsulations to be shipped to various facilities making it very advantageous for them to be certified as special form. To this end, DOT Certificates of Competent Authority (CoCAs) have been sought for the design suitable for containing high-alpha-activity actinide materials. This design consists of the high-alpha-activity material encapsulated within a triangular zirconia canister, referred to as a ZipCan, tile that is then enclosed by a spherical shell. The spherical shell design, with ZipCan tile inside, was tested for compliance with the special form regulations found in 49 CFR 173.469. The spherical enclosure was subjected to 9-m impact, 1 m percussion, and 10-minute thermal tests at the Packaging Evaluation Facility located at the National Transportation Research Center in Knoxville, TN USA and operated by ORNL. Before and after each test, the test units were subjected to a helium leak check and a bubble test. The ZipCan tiles and core were also subjected to the tests required for ISO 2919:2012(E), including a Class IV impact test and heat test and subsequently subjected to helium leakage rate tests [49 CFR 173.469(a)(4)(i)]. The impact

  18. Biomimetic active emulsions capture cell dynamics and direct bio-inspired materials

    NASA Astrophysics Data System (ADS)

    Ehrlicher, Allen; Amstad, Esther; Segmehl, Jana; Nakamura, Fumihiko; Stossel, Thomas; Pollak, Martin; Weitz, David

    2013-03-01

    The main biopolymers which make up the cellular cytoskeleton and provide cells with their shape are well understood, yet, how they organize into structures and set given cellular behavior remains unclear. We have reconstituted minimal networks of actin, a ubiquitous biopolymer, along with an associated motor protein myosin II to create biomimetic networks which replicate cell structure and actively contract when selectively provided with ATP. We emulsify these networks in 10-100 micron drops, provide a system to investigate strain-mediated protein interactions and network behavior in confined cell-similar volumes. These networks allow us to study strain-mediated protein-specific interactions in an actin network at a precision impossible in vivo. Using this system, we have identified strain-dependent behavior in actin cross linking proteins; mechanotransduction of signaling proteins in Filamin A, and unique catch-bond behavior in Alpha-actinin. This understanding of biopolymer self-organization to set cell mechanics, will help clarify how biology both generates and reacts to force; moreover this system provides a highly controlled platform for studying non-equilibrium materials, and creating microscopic building block for a entirely new class of active materials.

  19. Non-destructive testing of composite materials by means of active thermography-based tools

    NASA Astrophysics Data System (ADS)

    Lizaranzu, Miguel; Lario, Alberto; Chiminelli, Agustín; Amenabar, Ibán

    2015-07-01

    Infrared analysis tools are nowadays widely used for the non-destructive testing of components made up in composite materials, belonging to many different industrial sectors. Being a non-contact method, its capability for the inspection of large areas in short periods of time justifies the great number of works and technical studies that can be found in this field. The growing interest in the technique is also supported by the development, during recent years, of increasingly powerful equipment and data analysis tools. In order to establish a base of knowledge to assist defect identification in real components inspections, the design and manufacturing of inspection samples including controlled defects, is a frequently used strategy. This paper deals with the analysis, by means of transient active thermography, of a set of inspection patterns made out of different composite materials and configurations that can be found in the wind turbine blade manufacturing industry. The design and manufacturing of these patterns are described, including different types of representative defects, stack configurations and composite manufacturing techniques. Reference samples are then inspected by means of active thermography analysis tools and the results obtained are discussed.

  20. Enhanced photosynthetic activity in Spinacia oleracea by spectral modification with a photoluminescent light converting material.

    PubMed

    Xia, Qi; Batentschuk, Miroslaw; Osvet, Andres; Richter, Peter; Häder, Donat P; Schneider, Juergen; Brabec, Christoph J; Wondraczek, Lothar; Winnacker, Albrecht

    2013-11-01

    The spectral conversion of incident sunlight by appropriate photoluminescent materials has been a widely studied issue for improving the efficiency of photovoltaic solar energy harvesting. By using phosphors with suitable excitation/emission properties, also the light conditions for plants can be adjusted to match the absorption spectra of chlorophyll dyes, in this way increasing the photosynthetic activity of the plant. Here, we report on the application of this principle to a high plant, Spinacia oleracea. We employ a calcium strontium sulfide phosphor doped with divalent europium (Ca0.4Sr0.6S:Eu(2+), CSSE) on a backlight conversion foil in photosynthesis experiments. We show that this phosphor can be used to effectively convert green to red light, centering at a wavelength of ~650 nm which overlaps the absorption peaks of chlorophyll a/b pigments. A measurement system was developed to monitor the photosynthetic activity, expressed as the CO2 assimilation rate of spinach leaves under various controlled light conditions. Results show that under identical external light supply which is rich in green photons, the CO2 assimilation rate can be enhanced by more than 25% when the actinic light is modified by the CSSE conversion foil as compared to a purely reflecting reference foil. These results show that the phosphor could be potentially applied to modify the solar spectrum by converting the green photons into photosynthetically active red photons for improved photosynthetic activity.

  1. SEQUESTRATION OF METALS IN ACTIVE CAP MATERIALS: A LABORATORY AND NUMERICAL EVALUATION

    SciTech Connect

    Dixon, K.; Knox, A.

    2012-02-13

    Active capping involves the use of capping materials that react with sediment contaminants to reduce their toxicity or bioavailability. Although several amendments have been proposed for use in active capping systems, little is known about their long-term ability to sequester metals. Recent research has shown that the active amendment apatite has potential application for metals contaminated sediments. The focus of this study was to evaluate the effectiveness of apatite in the sequestration of metal contaminants through the use of short-term laboratory column studies in conjunction with predictive, numerical modeling. A breakthrough column study was conducted using North Carolina apatite as the active amendment. Under saturated conditions, a spike solution containing elemental As, Cd, Co, Se, Pb, Zn, and a non-reactive tracer was injected into the column. A sand column was tested under similar conditions as a control. Effluent water samples were periodically collected from each column for chemical analysis. Relative to the non-reactive tracer, the breakthrough of each metal was substantially delayed by the apatite. Furthermore, breakthrough of each metal was substantially delayed by the apatite compared to the sand column. Finally, a simple 1-D, numerical model was created to qualitatively predict the long-term performance of apatite based on the findings from the column study. The results of the modeling showed that apatite could delay the breakthrough of some metals for hundreds of years under typical groundwater flow velocities.

  2. Using Plasma-Activated High Performance Fibers with Nanocrystalline Structure in Producing New Reinforced Composite Materials

    NASA Astrophysics Data System (ADS)

    Kudinov, V.; Korneeva, N.

    2008-08-01

    A wet-pull-out method for investigation of interaction between the high performance polyethylene (HPPE) fiber and polymer matrix is discussed. The paper concerns a cold plasma technique for improving the bond of the HPPE fibers to the matrices and the fibers impregnation with the matrix. Controlled parameters are pull-out force and the height of the matrix capillary lifting along the fiber both in air and in vacuum, in combination with plasma activation of the fibers. The method allows one to estimate the wetting and impregnation of multi-filament fiber with the matrix and simultaneously measure the joint strength. Coupled action of plasma treatment and vacuum impregnation of the fibers improves the joint strength by a factor of 3. Plasma activated HPPE fibers impregnated in air show the value of shear strength τ of 4 Kg/mm2. To understand the effect of treatment initial and plasma-activated fibers were used to fabricate composite materials (CM). The properties and failure modes were compared to those of CM reinforced with untreated fibers. The failure mode of CM reinforced with plasma-activated fibers points to a high strength of the bond between the fibers and the matrix.

  3. Occupational exposure to airborne asbestos from phenolic molding material (Bakelite) during sanding, drilling, and related activities.

    PubMed

    Mowat, Fionna; Bono, Michael; Lee, R J; Tamburello, Susan; Paustenbach, Dennis

    2005-10-01

    In this study, a historical phenolic (Bakelite) molding material, BMMA-5353, was tested to determine the airborne concentrations of asbestos fibers released during four different activities (sawing, sanding, drilling, and cleanup of dust generated from these activities). Each activity was performed for 30 min, often in triplicate. The primary objective for testing BMMA-5353 was to quantitatively determine the airborne concentration of asbestos fibers, if any, in the breathing zone of workers. Uses of this product typically did not include sawing or sanding, but it may have been drilled occasionally. For this reason, only small quantities were sawed, sanded, and drilled in this simulation study. Personal (n = 40), area (n = 80), and background/clearance (n = 88) air samples were collected during each activity and analyzed for total fiber concentrations using phase contrast microscopy (PCM) and, for asbestos fiber counts, transmission electron microscopy (TEM). The raw PCM-total fiber concentrations were adjusted based on TEM analyses that reported the fraction of asbestos fibers, to derive a PCM-asbestos concentration that would enable calculation of an 8-hour time-weighted average (TWA). The estimated 8-hour TWAs ranged from 0.006 to 0.08 fibers per cubic centimeter using a variety of worker exposure scenarios. Therefore, assuming an exposure scenario in which a worker uses power tools to cut and sand products molded from BMMA-5353 and similar products in the manner evaluated in this study, airborne asbestos concentrations should not exceed current or historical occupational exposure limits.

  4. Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.

    PubMed

    Pintwala, Robert; Postnikoff, Cameron; Molladavoodi, Sara; Gorbet, Maud

    2015-03-01

    Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p < 0.03) versus control (no intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p < 0.03) and increased expression of α-smooth muscle actin in HLE B-3 after six days, although only poly(2-hydroxyethyl methacrylate) induced a significant difference versus control (p < 0.01). Our results imply that-contrary to prior uveal biocompatibility understanding-macrophage adherence is not necessary for a strong inflammatory response to an intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal

  5. Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.

    PubMed

    Pintwala, Robert; Postnikoff, Cameron; Molladavoodi, Sara; Gorbet, Maud

    2015-03-01

    Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p < 0.03) versus control (no intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p < 0.03) and increased expression of α-smooth muscle actin in HLE B-3 after six days, although only poly(2-hydroxyethyl methacrylate) induced a significant difference versus control (p < 0.01). Our results imply that-contrary to prior uveal biocompatibility understanding-macrophage adherence is not necessary for a strong inflammatory response to an intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal

  6. Controlling lipid oxidation via a biomimetic iron chelating active packaging material.

    PubMed

    Tian, Fang; Decker, Eric A; Goddard, Julie M

    2013-12-18

    Previously, a siderophore-mimetic metal chelating active packaging film was developed by grafting poly(hydroxamic acid) (PHA) from the surface of polypropylene (PP) films. The objective of the current work was to demonstrate the potential applicability of this PP-g-PHA film to control iron-promoted lipid oxidation in food emulsions. The iron chelating activity of this film was investigated, and the surface chemistry and color intensity of films were also analyzed after iron chelation. In comparison to the iron chelating activity in the free Fe(3+) solution, the PP-g-PHA film retained approximately 50 and 30% of its activity in nitrilotriacetic acid (NTA)/Fe(3+) and citric acid/Fe(3+) solutions, respectively (pH 5.0), indicating a strong chelating strength for iron. The ability of PP-g-PHA films to control lipid oxidation was demonstrated in a model emulsion system (pH 3.0). PP-g-PHA films performed even better than ethylenediaminetetraacetic acid (EDTA) in preventing the formation of volatile oxidation products. The particle size and ζ potential results of emulsions indicated that PP-g-PHA films had no adverse effects on the stability of the emulsion system. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis suggested a non-migratory nature of the PP-g-PHA film surface. These results suggest that such biomimetic, non-migratory metal chelating active packaging films have commercial potential in protecting foods against iron-promoted lipid oxidation. PMID:24313833

  7. Decanting of Neutralized H-Canyon Unirradiated Nuclear Material High Activity Waste Streams

    SciTech Connect

    BRONIKOWSKI, MICHAELG.

    2004-08-05

    An option to dispose of the High Activity Waste (HAW) stream from the processing of unirradiated materials directly to Saltstone is being evaluated to conserve High Level Waste (HLW) tank farm space and to reduce the future production of HLW glass logs. To meet the Saltstone Waste Acceptance Criteria (WAC), decanting the supernate from precipitated solids was proposed to reduce mercury and radionuclide levels in the waste. Only the caustic supernate will then be sent to Saltstone. Verification that the Saltstone WAC will be met has involved a series of laboratory studies using surrogate and actual HAW solutions from H-Canyon. The initial experiment involved addition of sodium hydroxide (NaOH) to a surrogate HAW test solution and subsequent decanting of the supernate away from the precipitated solids. The chemical composition of the surrogate solution was based on a composition defined from analyses of actual HAW solutions generated during dissolution of unirradiated nuclear materials in H-Canyon [1]. Results from testing the surrogate HAW solution were reported in Reference [2]. Information obtained from the surrogate test solution study was used to define additional experiments on actual HAW solutions obtained from H-Canyon. These experiments were conducted with samples from three different batches of HAW solutions. The first and third HAW samples (HAW No.1 and HAW No.3 solutions) contained the centrifuge filter cake material from a gelatin strike that is periodically added to the waste stream. The second HAW sample (HAW No.2 solution) did not contain filter cake material. Monosodium titanate (MST) was added to the HAW No.2 and HAW No.3 solutions after addition of NaOH was complete and before the settling step. The addition of MST was to improve the decontamination of alpha and beta emitters (primarily plutonium and strontium) from the supernate. The addition of excess NaOH and the addition of MST were expected to result in sufficient alpha and beta

  8. Active millimeter-wave imaging system for material analysis and object detection

    NASA Astrophysics Data System (ADS)

    Zech, Christian; Hülsmann, Axel; Kallfass, Ingmar; Tessmann, Axel; Zink, Martin; Schlechtweg, Michael; Leuther, Arnulf; Ambacher, Oliver

    2011-11-01

    The use of millimeter-waves for imaging purposes is becoming increasingly important, as millimeter-waves can penetrate most clothing and packaging materials, so that the detector does not require physical contact with the object. This will offer a view to the hidden content of e.g. packets or bags without the need to open them, whereby packaging and content will not be damaged. Nowadays X-ray is used, but as the millimeter-wave quantum energy is far below the ionization energy, it is less harmful for the human health. In this paper we report an active millimeter-wave imaging tomograph for material analysis and concealed object detection purposes. The system is build using in-house W-band components. The object is illuminated with low-power millimeter-waves in the frequency range between 89 and 96GHz; mirrors are used to guide and focus the beam. The object is moved through the focus point to scan the object pixel by pixel. Depending on the actual material some parts of the waves are reflected, the other parts penetrate the object. A single-antenna transmit and receive module is used for illumination and measurement of the material-specific reflected power. A second receiver module is used to measure the transmitted wave. All information is processed for amplitude and phase images by a computer algorithm. The system can be used for security, such as detecting concealed weapons, explosives or contrabands at airports and other safety areas, but also quality assurance applications, e.g. during production to detect defects. Some imaging results will be presented in this paper.

  9. Dehydrogenase activity and quality of leachates in Technosols with gossan and sulfide materials from the São Domingos mine

    NASA Astrophysics Data System (ADS)

    Santos, Erika; Abreu, Manuela; Macías, Felipe; de Varennes, Amarílis

    2014-05-01

    Wastes produced by mining activity in São Domingos (Portuguese Iberian Pyrite Belt) were disposed over a large area. To speed up the ecological rehabilitation in this mine, an integrative strategy using different amendments+mine wastes was used to produce Technosols with enhanced soil functions. To evaluate the efficiency of these Technosols the dehydrogenase activity and chemical quality of leachates were monitored. Technosols were composed of different mine wastes (gossan and sulfide materials), collected at the São Domingos mine, and mixtures of amendments applied at 30 and 75 Mg/ha (rockwool+agriculture wastes+wastes from liquors distillation of strawberry tree fruits (Arbutus unedo L.) and/or carobs (Ceratonia siliqua L. fruits)). Three assays, under controlled conditions, were carried out: (1 and 2) Sulfide or gossan materials with/without amendments; (3) Sulfide wastes, with/without amendments, incubated during four months and then with application of an overlayer of gossan (~3 cm thick) with/without the same amendments. Dehydrogenase activity (DHA) and chemical characteristics of leachates (multielemental concentration, pH, and electric conductivity) were determined after four/seven/thirteen months of incubation. Sulfide wastes had more hazardous characteristics (pH~2 and total concentrations (g/kg) of Al (58.1), As (1.1), Cu (2.1), Fe (107.3), Pb (11.7), S (65.3) and Zn (1.1) than the gossan materials (pH=4.3; g/kg, Al: 24.8, As: 3.0, Cu: 0.2, Fe: 129, Pb: 9.2, S: 13.7, Zn: 0.04). Amendments application to gossan (assay 2) enhanced DHA in both sampling periods (µg TPF g dry weight 16 h-1, Control: 0,72-1,78; Amended treatments: 2.49-16.36 depending on mixture/application rate/sampling period). Greater application rates stimulated DHA (more than 1.5-fold with 75 Mg/ha). No differences were observed in DHA in the gossan layer with/without amendments (assay 3) suggesting a negative impact on gossan microrganisms from sulfide materials located below. In

  10. Alkylator-Induced and Patient-Derived Xenograft Mouse Models of Therapy-Related Myeloid Neoplasms Model Clinical Disease and Suggest the Presence of Multiple Cell Subpopulations with Leukemia Stem Cell Activity.

    PubMed

    Jonas, Brian A; Johnson, Carl; Gratzinger, Dita; Majeti, Ravindra

    2016-01-01

    Acute myeloid leukemia (AML) is a heterogeneous group of aggressive bone marrow cancers arising from transformed hematopoietic stem and progenitor cells (HSPC). Therapy-related AML and MDS (t-AML/MDS) comprise a subset of AML cases occurring after exposure to alkylating chemotherapy and/or radiation and are associated with a very poor prognosis. Less is known about the pathogenesis and disease-initiating/leukemia stem cell (LSC) subpopulations of t-AML/MDS compared to their de novo counterparts. Here, we report the development of mouse models of t-AML/MDS. First, we modeled alkylator-induced t-AML/MDS by exposing wild type adult mice to N-ethyl-N-nitrosurea (ENU), resulting in several models of AML and MDS that have clinical and pathologic characteristics consistent with human t-AML/MDS including cytopenia, myelodysplasia, and shortened overall survival. These models were limited by their inability to transplant clinically aggressive disease. Second, we established three patient-derived xenograft models of human t-AML. These models led to rapidly fatal disease in recipient immunodeficient xenografted mice. LSC activity was identified in multiple HSPC subpopulations suggesting there is no canonical LSC immunophenotype in human t-AML. Overall, we report several new t-AML/MDS mouse models that could potentially be used to further define disease pathogenesis and test novel therapeutics. PMID:27428079

  11. Alkylator-Induced and Patient-Derived Xenograft Mouse Models of Therapy-Related Myeloid Neoplasms Model Clinical Disease and Suggest the Presence of Multiple Cell Subpopulations with Leukemia Stem Cell Activity

    PubMed Central

    Johnson, Carl; Gratzinger, Dita; Majeti, Ravindra

    2016-01-01

    Acute myeloid leukemia (AML) is a heterogeneous group of aggressive bone marrow cancers arising from transformed hematopoietic stem and progenitor cells (HSPC). Therapy-related AML and MDS (t-AML/MDS) comprise a subset of AML cases occurring after exposure to alkylating chemotherapy and/or radiation and are associated with a very poor prognosis. Less is known about the pathogenesis and disease-initiating/leukemia stem cell (LSC) subpopulations of t-AML/MDS compared to their de novo counterparts. Here, we report the development of mouse models of t-AML/MDS. First, we modeled alkylator-induced t-AML/MDS by exposing wild type adult mice to N-ethyl-N-nitrosurea (ENU), resulting in several models of AML and MDS that have clinical and pathologic characteristics consistent with human t-AML/MDS including cytopenia, myelodysplasia, and shortened overall survival. These models were limited by their inability to transplant clinically aggressive disease. Second, we established three patient-derived xenograft models of human t-AML. These models led to rapidly fatal disease in recipient immunodeficient xenografted mice. LSC activity was identified in multiple HSPC subpopulations suggesting there is no canonical LSC immunophenotype in human t-AML. Overall, we report several new t-AML/MDS mouse models that could potentially be used to further define disease pathogenesis and test novel therapeutics. PMID:27428079

  12. Development and qualification of functional materials for the EU Test Blanket Modules: Strategy and R&D activities

    NASA Astrophysics Data System (ADS)

    Zmitko, M.; Poitevin, Y.; Boccaccini, L.; Salavy, J.-F.; Knitter, R.; Möslang, A.; Magielsen, A. J.; Hegeman, J. B. J.; Lässer, R.

    2011-10-01

    Europe has developed two reference tritium breeder blankets concepts for a DEMO fusion reactor: the Helium-Cooled Lithium-Lead and the Helium-Cooled Pebble-Bed. Both will be tested in ITER under the form of Test Blanket Modules (TBMs). The paper reviews the current status of development and qualification of the EU TBMs functional materials; i.e. ceramic solid breeder materials, beryllium/beryllides multiplier materials and Lithium-Lead liquid metal breeder material Pb-15.7Li. For each functional material the main functional/performance requirements with key qualification issues, current status of the R&D activities and the EU development strategy are presented. In the development strategy major steps considered are listed pointing out importance of the 'Development/qualification/procurement plan', currently under elaboration, for definition of a roadmap of further activities aiming at delivery of qualified functional materials to be used in the European TBMs in ITER.

  13. Separation and Enrichment of the Active Component of Carbon Based Paramagnetic Materials for Use in EPR Oximetry

    NASA Astrophysics Data System (ADS)

    Liu, K. J.; Miyake, M.; James, P. E.; Swartz, H. M.

    1998-08-01

    Carbon based paramagnetic materials are frequently used for EPR oximetry, especiallyin vivo,but the EPR spectra of these materials often have more than one paramagnetic center and/or relatively low signal intensity. To determine whether the multi-components of carbon based materials could be separated and enriched in the active component, we used density gradient centrifugation to separate the materials into several fractions. We studied two types of coals, gloxy and Pocahontas, and found these materials to have large density distribution. The separated density fractions had very different EPR spectra and intensities. The active component from the coal material had a more homogeneous EPR signal and significantly increased EPR signal intensity, whereas for India ink, only slight changes were observed. This result can be very useful in the development of better probes for EPR oximetry.

  14. Separation and enrichment of the active component of carbon based paramagnetic materials for use in EPR oximetry.

    PubMed

    Liu, K J; Miyake, M; James, P E; Swartz, H M

    1998-08-01

    Carbon based paramagnetic materials are frequently used for EPR oximetry, especially in vivo, but the EPR spectra of these materials often have more than one paramagnetic center and/or relatively low signal intensity. To determine whether the multi-components of carbon based materials could be separated and enriched in the active component, we used density gradient centrifugation to separate the materials into several fractions. We studied two types of coals, gloxy and Pocahontas, and found these materials to have large density distribution. The separated density fractions had very different EPR spectra and intensities. The active component from the coal material had a more homogeneous EPR signal and significantly increased EPR signal intensity, whereas for India ink, only slight changes were observed. This result can be very useful in the development of better probes for EPR oximetry.

  15. Removal of Pb, Cd, and Cr in a water purification system using modified mineral waste materials and activated carbon derived from waste materials

    NASA Astrophysics Data System (ADS)

    Lu, H. R.; Su, L. C.; Ruan, H. D.

    2016-08-01

    This study attempts to find out and optimize the removal efficiency of heavy metals in a water purification unit using a low-cost waste material and modified mineral waste materials (MMWM) accompanied with activated carbon (AC) derived from waste materials. The factors of the inner diameter of the purification unit (2.6-5cm), the height of the packing materials (5-20cm), the size of AC (200-20mesh), the size of MMWM (1-0.045mm), and the ratio between AC and MMWM in the packing materials (1:0 - 0:1) were examined based on a L18 (5) 3 orthogonal array design. In order to achieve an optimally maximum removal efficiency, the factors of the inner diameter of the purification unit (2.6-7.5cm), the height of the packing materials (10-30cm), and the ratio between AC and MMWM in the packing materials (1:4-4:1) were examined based on a L16 (4) 3 orthogonal array design. A height of 25cm, inner diameter of 5cm, ratio between AC and MMWM of 3:2 with size of 60-40mesh and 0.075-0.045mm, respectively, were the best conditions determined by the ICP-OES analysis to perform the adsorption of heavy metals in this study.

  16. Crossing Cultures--Third World Women. A Book of Materials, Activities, and Ideas for the Classroom Teacher.

    ERIC Educational Resources Information Center

    Valiant, Sharon

    This resource bibliography includes and briefly discusses activities and instructional materials on the lives of women in the non-European/non-white world, suitable for use in elementary and secondary school rooms. The books, films, and other materials give a sampling of ideas and contributions often overlooked in middle-class America (for…

  17. Monitoring volcano precursory activity with the materials failure approach, using rates of cumulative seismic coda length

    SciTech Connect

    Cornelius, R.R.; Voight, B. . Dept. of Geosciences)

    1992-01-01

    The proportionality between the energy, E, of an elastic wave and the square of its amplitude led to the usage of Benioff diagrams'' for purposes of volcano monitoring. These diagrams show the time-integrated amplitude as [radical]E versus time. The authors propose to use accelerating cumulative coda length directly in volcano monitoring. This surrogate measure of energy'' is used for practical reasons, as it eliminates the intermediate step required for energy calculations with regional and instrument-specific constants. Rates of cumulative coda (s/day) may be used for the materials failure approach'' to eruption prediction, which fits data according to an empirical rate-acceleration relationship. The method allows numerical or graphical rate extrapolation towards the expected failure rate; eruption windows may be established. Rate series derived from either cumulative amplitude, cumulative coda, or calculated [radical]E can be analyzed by the materials failure approach equally well; neither series is favored by this method because of similar characteristics. They suggest rate interpolation from the time-integrated data over constant coda-increments instead of over constant time-increments. This results in an increasingly higher frequency of rate data towards the end of an accelerating time series. The end-weighted rate calculation emphasizes the latest precursory developments while it smooths noise at lower rates. Adjusting the applied constant coda-increment for rate calculations as a function of total encountered coda, is a technique for an automated and sequential update of the extrapolated failure time.

  18. Gamma activity of stream sediment feldspars as ceramic raw materials and their environmental impact.

    PubMed

    Aboelkhair, Hatem; Ibrahim, Tarek; Saad, Ahmed

    2012-08-01

    In situ gamma spectrometric measurements have been performed to characterise the natural radiation that emitted from the stream sediment feldspars in Wadi El Missikat and Wadi Homret El Gergab, Eastern Desert, Egypt. The measurements of potassium (K, %), equivalent uranium (eU, ppm) and equivalent thorium (eTh, ppm) were converted into specific activities and equivalent dose rate. The average specific activities were 1402 Bq kg(-1) for K, 113 Bq kg(-1) for eU and 108 Bq kg(-1) for eTh in Wadi El Missikat, while they were 1240, 104 and 185 Bq kg(-1) in Wadi Homret El Gergab. The calculated outdoor average effective dose rates was 1.1 mSv y(-1) in wadi El Missikat and 1.3 mSv y(-1) in Wadi Homret El Gergab. The terrestrial-specific activities and effective dose rate levels of the natural radioactivity in the two areas lie within the international recommended limits for occupational feldspar quarry workers. On the other hand, these results indicated that irradiation is higher than the allowable level for members of the public. Therefore, quarrying the feldspar sediments from these locations as ceramic raw materials may yield an undesired impact on the environment, especially through the indoor applications. PMID:22171098

  19. Investigation of Active Interrogation Techniques to Detect Special Nuclear Material in Maritime Environments

    SciTech Connect

    Miller, Thomas Martin; Patton, Bruce W

    2010-01-01

    The detection and interdiction of special nuclear material (SNM) is still a high-priority focus area for many organizations around the world. One method that is commonly considered a leading candidate in the detection of SNM is active interrogation (AI). AI is different from its close relative, passive interrogation, in that an active source is used to enhance or create a detectable signal (usually fission) from SNM, particularly in shielded scenarios or scenarios where the SNM has a low activity. The use of AI thus makes the detection of SNM easier or, in some scenarios, even enables previously impossible detection. In this work the signal from prompt neutrons and photons as well as delayed neutrons and photons will be combined, as is typically done in AI. In previous work AI has been evaluated experimentally and computationally. However, for the purposes of this work, past scenarios are considered lightly shielded and tightly coupled spatially. At most, the previous work interrogated the contents of one standard cargo container (2.44 x 2.60 x 6.10 m) and the source and detector were both within a few meters of the object being interrogated. A few examples of this type of previous work can be found in references 1 and 2. Obviously, more heavily shielded AI scenarios will require larger source intensities, larger detector surface areas (larger detectors or more detectors), greater detector efficiencies, longer count times, or some combination of these.

  20. Gamma activity of stream sediment feldspars as ceramic raw materials and their environmental impact.

    PubMed

    Aboelkhair, Hatem; Ibrahim, Tarek; Saad, Ahmed

    2012-08-01

    In situ gamma spectrometric measurements have been performed to characterise the natural radiation that emitted from the stream sediment feldspars in Wadi El Missikat and Wadi Homret El Gergab, Eastern Desert, Egypt. The measurements of potassium (K, %), equivalent uranium (eU, ppm) and equivalent thorium (eTh, ppm) were converted into specific activities and equivalent dose rate. The average specific activities were 1402 Bq kg(-1) for K, 113 Bq kg(-1) for eU and 108 Bq kg(-1) for eTh in Wadi El Missikat, while they were 1240, 104 and 185 Bq kg(-1) in Wadi Homret El Gergab. The calculated outdoor average effective dose rates was 1.1 mSv y(-1) in wadi El Missikat and 1.3 mSv y(-1) in Wadi Homret El Gergab. The terrestrial-specific activities and effective dose rate levels of the natural radioactivity in the two areas lie within the international recommended limits for occupational feldspar quarry workers. On the other hand, these results indicated that irradiation is higher than the allowable level for members of the public. Therefore, quarrying the feldspar sediments from these locations as ceramic raw materials may yield an undesired impact on the environment, especially through the indoor applications.

  1. 3-d Brownian dynamics simulations of the smallest units of an active biological material

    NASA Astrophysics Data System (ADS)

    Luettmer-Strathmann, Jutta; Paudyal, Nabina; Adeli Koudehi, Maral

    Motor proteins generate stress in a cytoskeletal network by walking on one strand of the network while being attached to another one. A protein walker in contact with two elements of the network may be considered the smallest unit of an active biological material. In vitro experiments, mathematical modeling and computer simulations have provided important insights into active matter on large and on very small length and time scales. However, it is still difficult to model the effects of local environment and interactions at intermediate scales. Recently, we developed a coarse-grained, three-dimensional model for a motor protein transporting cargo by walking on a substrate. In this work, we simulate a tethered motor protein pulling a substrate with elastic response. As the walker progresses, the retarding force due to the substrate tension increases until contact fails. We present simulation results for the effect of motor-protein activity on the tension in the substrate and the effect of the retarding force on the processivity of the molecular motor.

  2. Analysis of Induced Gamma Activation by D-T Neutrons in Selected Fusion Reactor Relevant Materials with EAF-2010

    NASA Astrophysics Data System (ADS)

    Klix, Axel; Fischer, Ulrich; Gehre, Daniel

    2016-02-01

    Samples of lanthanum, erbium and titanium which are constituents of structural materials, insulating coatings and tritium breeder for blankets of fusion reactor designs have been irradiated in a fusion peak neutron field. The induced gamma activities were measured and the results were used to check calculations with the European activation system EASY-2010. Good agreement for the prediction of major contributors to the contact dose rate of the materials was found, but for minor contributors the calculation deviated up to 50%.

  3. Exploring the Geometry of Circumnuclear Material in Active Galactic Nuclei through X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rivers, Elizabeth

    I have studied the X-ray spectral properties of active galactic nuclei (AGN) in order to gain a better understanding of the nature of the circumnuclear material surrounding the central black hole in these objects. From the RXTE archive I constructed two survey samples of broad band X-ray spectra. The first was a bright sample of 23 AGN that had high quality spectra up to at least 100 keV, which provided constraints on the high energy rollover expected by models of inverse Comptonization of low energy photons. The average lower limit to Eroll was ˜225 keV for the majority of objects, implying a coronal electron temperature of kB Te ≳ 75 keV for these models. The second sample was an expanded survey of ˜100 AGN for which spectral parameters could be well-determined. I compared Fe line equivalent widths with measured Compton reflection hump strengths and found that on average ˜40% of the Fe line emission comes from reflection off Compton-thick material, with the remainder likely arising in isotropic emission from Compton-thin gas. In the full sample, the distributions of photon indices for Seyfert 1's and 2's were consistent with the idea that Seyferts share a common central engine, however the distributions of Compton reflection hump strengths did not support the classical picture of absorption by a torus and reflection off a Compton-thick disk with type depending only on inclination angle. I have concluded that a more complex reflecting geometry such as a combined disk and torus or clumpy torus is likely a more accurate picture of the Compton-thick material. I have performed additional analyses of individual objects. An occultation event in Cen A, discovered through RXTE monitoring, revealed the clumpy nature of its torus and placed constraints on the amount of material in the vicinity of the black hole in this object. A Suzaku long-look observation of MCG-2-58-22 provided constraints on the location of Fe line emitting material to ≳ 1200RS, likely associated

  4. Physics Courses--Some Suggested Case Studies

    ERIC Educational Resources Information Center

    Swetman, T. P.

    1972-01-01

    To communicate the relevance and excitement of science activity to students, the use of more imaginative, and even openly speculative, case studies in physics courses is suggested. Some useful examples are Magnetic Monopoles, Constants, Black Holes, Antimatter, Zero Mass Particles, Tachyons, and the Bootstrap Hypothesis. (DF)

  5. Youth Physical Fitness. Suggestions for School Programs.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    This book, divided into three main parts--basic, advanced, and comprehensive programs--suggests (a) basic physical education programs designed to assist classroom teachers inexperienced in physical education to develop activities that will make a contribution to the physical fitness of the children in their charge and (b) advanced activities…

  6. Photocatalytic degradation of an azo-dye on TiO2/activated carbon composite material.

    PubMed

    Andriantsiferana, C; Mohamed, E F; Delmas, H

    2014-01-01

    A sequential adsorption/photocatalytic regeneration process to remove tartrazine, an azo-dye in aqueous solution, has been investigated. The aim ofthis work was to compare the effectiveness of an adsorbent/photocatalyst composite-TiO2 deposited onto activated carbon (AC) - and a simple mixture of powders of TiO2 and AC in same proportion. The composite was an innovative material as the photocatalyst, TiO2, was deposited on the porous surface ofa microporous-AC using metal-organic chemical vapour deposition in fluidized bed. The sequential process was composed of two-batch step cycles: every cycle alternated a step of adsorption and a step of photocatalytic oxidation under ultra-violet (365 nm), at 25 degreeC and atmospheric pressure. Both steps, adsorption and photocatalytic oxidation, have been investigated during four cycles. For both materials, the cumulated amounts adsorbed during four cycles corresponded to nearly twice the maximum adsorption capacities qmax proving the photocatalytic oxidation to regenerate the adsorbent. Concerning photocatalytic oxidation, the degree of mineralization was higher with the TiO2/AC composite: for each cycle, the value of the total organic carbon removal was 25% higher than that obtained with the mixture powder. These better photocatalytic performances involved better regeneration than higher adsorbed amounts for cycles 2, 3 and 4. Better performances with this promising material - TiO2 deposited onto AC - compared with TiO2 powder could be explained by the vicinity of photocatalytic and AC adsorption sites.

  7. Science-based material modeling activities at Sandia National Laboratories/California : an overview.

    SciTech Connect

    Chen, Er-Ping

    2004-08-01

    The purpose of this presentation is to provide an overview of the science-based materials modeling activities at Sandia National Laboratories, California. The main mission driver for the work is the development of predictive modeling and simulation capabilities leveraging high performance computing software and hardware. Presentation will highlight research accomplishments in several specific topics of current interest. Sandia/California has been engaged in the development of high performance computing based predictive modeling and simulation capabilities in support of the Science-Based Stockpile Stewardship Program of the U. S. Department of Energy. Of particular interest is the development of constitutive models that can efficiently and accurately predict post-failure material response and load-redistribution in systems and components. Fracture and failure are inherently multi-scale and our philosophy is to include required physics in our models at all appropriate scales. We approach the problems from the continuum point of view and intend to provide continuum models that include dominant subscale mechanisms. Moreover, numerical algorithms are needed to allow implementation of physical models in high performance computing codes such that large-scale modeling and simulation can be conducted. Other drivers of our effort include the emerging application of micro- and nano-systems and the increasing interest in biotechnology. In this presentation, our research in fracture and failure modeling, atomic-continuum coupling code development, microstructure-material properties relationships exploration, and general continuum theories advancement will be presented. Where appropriate, examples will be given to demonstrate the utility of the models.

  8. Effects of coal rank on the chemical composition and toxicological activity of coal liquefaction materials

    SciTech Connect

    Wright, C.W.; Dauble, D.D.

    1986-05-01

    This report presents data from the chemical analysis and toxicological testing of coal liquefaction materials from the EDS and H-Coal processes operated using different ranks of coal. Samples of recycle solvent from the bottoms recycle mode of the EDS direct coal liquefaction process derived from bituminous, sub-bituminous, and lignite coals were analyzed. In addition, the H-Coal heavy fuel oils derived from bituminous and sub-bituminous coals were analyzed. Chemical methods of analysis included adsoprtion column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, and low-voltage probe-inlet mass spectrometry. The toxicological activity of selected samples was evaluated using the standard microbial mutagenicity assay, an initiation/promotion assay for mouse-skin tumorigenicity, and a static bioassy with Daphnia magna for aquatic toxicity of the water-soluble fractions. 22 refs., 16 figs., 14 tabs.

  9. [Application of biologically active suture materials in emergency surgery of abdominal cavity organs].

    PubMed

    Mokhov, E M; Chumakov, R Iu; Sergeev, A N

    2012-01-01

    An investigation of specific course of the wound process and near results of operations on 398 patients with emergency abdominal surgical pathology has revealed advantages of using new biologically active suture materials "Nikant" (with doxicyclin) and "Nikant-P" (with doxicyclin and stimulator of regeneration from the group of hermanium-containing organic compounds) in performing surgical interventions. Total number of patients with complications at the early postoperative period, operated using threads "Nikant" (38-29.9%) and "Nikant-P" (30-23.8%) proved to be reliably less than in patients of the control group (71-48.9%). The results of operations improved at the expense of considerable reduction of the number of postoperative local pyo-inflammatory processes.

  10. Neutron Activation Analysis of the Rare Earth Elements (REE) - With Emphasis on Geological Materials

    NASA Astrophysics Data System (ADS)

    Stosch, Heinz-Günter

    2016-08-01

    Neutron activation analysis (NAA) has been the analytical method of choice for rare earth element (REE) analysis from the early 1960s through the 1980s. At that time, irradiation facilitieswere widely available and fairly easily accessible. The development of high-resolution gamma-ray detectors in the mid-1960s eliminated, formany applications, the need for chemical separation of the REE from the matrix material, making NAA a reliable and effective analytical tool. While not as precise as isotopedilution mass spectrometry, NAA was competitive by being sensitive for the analysis of about half of the rare earths (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu). The development of inductively coupled plasma mass spectrometry since the 1980s, together with decommissioning of research reactors and the lack of installation of new ones in Europe and North America has led to the rapid decline of NAA.

  11. Metal-ion spin-on glasses: Novel materials for active waveguides

    SciTech Connect

    Ashby, C.I.H.; Sullivan, C.T.; Vawter, G.A.; Hohimer, J.P.; Hadley, G.R.; Neal, D.R.

    1993-12-31

    Monolithic integration of a rare-earth-ion-based active waveguide on the same wafer as its diode pump laser would permit compact packaging of the technology demonstrated in fiber lasers and amplifiers. This new monolithic technology would offer the potential for developing compact infrared and visible (up-conversion) lasers, amplifiers, and other photonic integrated circuit components. One approach that we are investigating for such monolithic integration uses a high concentration of one or more rare-earth ions incorporated into polysiloxane spin-on glasses that are solvent-cast onto III-V semiconductor wafers. This ``fiber on a chip`` technology substitute a relatively high-ion-concentration, short-length metal-ion spin-on glass (MISOG) waveguide for the low-ion-concentration, long-length fiber. Progress to data on developing MISOG waveguide materials and technology is discussed.

  12. Materials for the active layer of organic photovoltaics: ternary solar cell approach.

    PubMed

    Chen, Yung-Chung; Hsu, Chih-Yu; Lin, Ryan Yeh-Yung; Ho, Kuo-Chuan; Lin, Jiann T

    2013-01-01

    Power conversion efficiencies in excess of 7% have been achieved with bulk heterojunction (BHJ)-type organic solar cells using two components: p- and n-doped materials. The energy level and absorption profile of the active layer can be tuned by introduction of an additional component. Careful design of the additional component is required to achieve optimal panchromatic absorption, suitable energy-level offset, balanced electron and hole mobility, and good light-harvesting efficiency. This article reviews the recent progress on ternary organic photovoltaic systems, including polymer/small molecule/functional fullerene, polymer/polymer/functional fullerene, small molecule/small molecule/functional fullerene, polymer/functional fullerene I/functional fullerene II, and polymer/quantum dot or metal/functional fullerene systems.

  13. Viscoelasticity of living materials: mechanics and chemistry of muscle as an active macromolecular system.

    PubMed

    Qian, Hong

    2008-06-01

    At the molecular and cellular level, mechanics and chemistry are two aspects of the same macromolecular system. We present a bottom-up approach to such systems based on Kramers' diffusion theory of chemical reactions, the theory of polymer dynamics, and the recently developed models for molecular motors. Using muscle as an example, we develop a viscoelastic theory of muscle in terms of an simple equation for single motor protein movement. Both A.V. Hill's contractile component and A.F. Huxley's equation of sliding-filament motion are shown to be special cases of the general viscoelastic theory of the active material. Some disparity between the mechanical and the chemical views of cross-bridges and motor proteins are noted, and a duality between force and energy in discrete states and transitions of macromolecular systems is discussed.

  14. Processes for making dense, spherical active materials for lithium-ion cells

    DOEpatents

    Kang, Sun-Ho; Amine, Khalil

    2011-11-22

    Processes are provided for making dense, spherical mixed-metal carbonate or phosphate precursors that are particularly well suited for the production of active materials for electrochemical devices such as lithium ion secondary batteries. Exemplified methods include precipitating dense, spherical particles of metal carbonates or metal phosphates from a combined aqueous solution using a precipitating agent such as ammonium hydrogen carbonate, sodium hydrogen carbonate, or a mixture that includes sodium hydrogen carbonate. Other exemplified methods include precipitating dense, spherical particles of metal phosphates using a precipitating agent such as ammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, or a mixture of any two or more thereof. Further provided are compositions of and methods of making dense, spherical metal oxides and metal phosphates using the dense, spherical metal precursors. Still further provided are electrodes and batteries using the same.

  15. Comparing graphene, carbon nanotubes, and superfine powdered activated carbon as adsorptive coating materials for microfiltration membranes.

    PubMed

    Ellerie, Jaclyn R; Apul, Onur G; Karanfil, Tanju; Ladner, David A

    2013-10-15

    Multi-walled carbon nanotubes (MWCNTs), nano-graphene platelets (NGPs), and superfine powdered activated carbon (S-PAC) were comparatively evaluated for their applicability as adsorptive coatings on microfiltration membranes. The objective was to determine which materials were capable of contaminant removal while causing minimal flux reduction. Methylene blue and atrazine were the model contaminants. When applied as membrane coatings, MWCNTs had minimal retention capabilities for the model contaminants, and S-PAC had the fastest removal. The membrane coating approach was also compared with a stirred vessel configuration, in which the adsorbent was added to a stirred flask preceding the membrane cell. Direct application of the adsorbent to the membrane constituted a greater initial reduction in permeate concentrations of the model contaminants than with the stirred flask setup. All adsorbents except S-PAC showed flux reductions less than 5% after application as thin-layer membrane coatings, and flux recovery after membrane backwashing was greater than 90% for all materials and masses tested. PMID:23911830

  16. Imaging of heterogeneous materials by prompt gamma-ray neutron activation analysis

    SciTech Connect

    Staples, P.; Prettyman, T.; Lestone, J.

    1998-12-01

    The authors have used a tomographic gamma scanner (TGS) to produce tomographic prompt gamma-ray neutron activation analysis imaging (PGNAA) of heterogeneous matrices. The TGS was modified by the addition of graphite reflectors that contain isotopic neutron sources for sample interrogation. The authors are in the process of developing the analysis methodology necessary for a quantitative assay of large containers of heterogeneous material. This nondestructive analysis (NDA) technique can be used for material characterization and the determination of neutron assay correction factors. The most difficult question to be answered is the determination of the source-to-sample coupling term. To assist in the determination of the coupling term, the authors have obtained images for a range of sample that are very well characterized, such as, homogenous pseudo one-dimensional samples to three-dimensional heterogeneous samples. They then compare the measurements to MCNP calculations. For an accurate quantitative measurement, it is also necessary to determine the sample gamma-ray self attenuation at higher gamma-ray energies, namely pair production should be incorporated into the analysis codes.

  17. Cerato-platanin shows expansin-like activity on cellulosic materials.

    PubMed

    Baccelli, Ivan; Luti, Simone; Bernardi, Rodolfo; Scala, Aniello; Pazzagli, Luigia

    2014-01-01

    Cerato-platanin (CP) is a non-catalytic protein with a double ψβ-barrel fold located in the cell wall of the phytopathogenic fungus Ceratocystis platani. CP is released during growth and induces defence-related responses in plants. CP is also the first member of the "cerato-platanin family" (CPF) (Pfam PF07249). In the CPF, the molecular mechanism of action on plants and above all the biological role in fungal life are little-known aspects. However, an expansin-like function has recently been suggested concerning CP. Expansin-like proteins have the ability to act non-hydrolytically on cellulose. In the present work, the expansin-like activity of CP and Pop1, a CP family member, was investigated. Like expansins, CP and Pop1 were able to weaken filter paper in a concentration-dependent manner and without the production of reducing sugars. A metal-dependent polysaccharide monooxygenase-like activity was excluded. The optimum of activity was pH5.0, 38 °C. CP was also able to cause fragmentation of the crystalline cellulose Avicel and the breakage and defibration of cotton fibres. However, the interaction did not involve a stable bond with the substrates and CP did not significantly enhance the hydrolytic activity of cellulase. On the other hand, CP and Pop1 bound quickly to chitin. We consider CP as a novel one-domain expansin-like protein. We propose a structural role for CP in the fungal cell wall due to the ability to bind chitin, and hypothesize a functional role in the interaction of the fungus with the plant for the weakening activity shown on cellulose.

  18. Monte-Carlo modelling of nano-material photocatalysis: bridging photocatalytic activity and microscopic charge kinetics.

    PubMed

    Liu, Baoshun

    2016-04-28

    In photocatalysis, it is known that light intensity, organic concentration, and temperature affect the photocatalytic activity by changing the microscopic kinetics of holes and electrons. However, how the microscopic kinetics of holes and electrons relates to the photocatalytic activity was not well known. In the present research, we developed a Monte-Carlo random walking model that involved all of the charge kinetics, including the photo-generation, the recombination, the transport, and the interfacial transfer of holes and electrons, to simulate the overall photocatalytic reaction, which we called a "computer experiment" of photocatalysis. By using this model, we simulated the effect of light intensity, temperature, and organic surface coverage on the photocatalytic activity and the density of the free electrons that accumulate in the simulated system. It was seen that the increase of light intensity increases the electron density and its mobility, which increases the probability for a hole/electron to find an electron/hole for recombination, and consequently led to an apparent kinetics that the quantum yield (QY) decreases with the increase of light intensity. It was also seen that the increase of organic surface coverage could increase the rate of hole interfacial transfer and result in the decrease of the probability for an electron to recombine with a hole. Moreover, the increase of organic coverage on the nano-material surface can also increase the accumulation of electrons, which enhances the mobility for electrons to undergo interfacial transfer, and finally leads to the increase of photocatalytic activity. The simulation showed that the temperature had a more complicated effect, as it can simultaneously change the activation of electrons, the interfacial transfer of holes, and the interfacial transfer of electrons. It was shown that the interfacial transfer of holes might play a main role at low temperature, with the temperature-dependence of QY

  19. Monte-Carlo modelling of nano-material photocatalysis: bridging photocatalytic activity and microscopic charge kinetics.

    PubMed

    Liu, Baoshun

    2016-04-28

    In photocatalysis, it is known that light intensity, organic concentration, and temperature affect the photocatalytic activity by changing the microscopic kinetics of holes and electrons. However, how the microscopic kinetics of holes and electrons relates to the photocatalytic activity was not well known. In the present research, we developed a Monte-Carlo random walking model that involved all of the charge kinetics, including the photo-generation, the recombination, the transport, and the interfacial transfer of holes and electrons, to simulate the overall photocatalytic reaction, which we called a "computer experiment" of photocatalysis. By using this model, we simulated the effect of light intensity, temperature, and organic surface coverage on the photocatalytic activity and the density of the free electrons that accumulate in the simulated system. It was seen that the increase of light intensity increases the electron density and its mobility, which increases the probability for a hole/electron to find an electron/hole for recombination, and consequently led to an apparent kinetics that the quantum yield (QY) decreases with the increase of light intensity. It was also seen that the increase of organic surface coverage could increase the rate of hole interfacial transfer and result in the decrease of the probability for an electron to recombine with a hole. Moreover, the increase of organic coverage on the nano-material surface can also increase the accumulation of electrons, which enhances the mobility for electrons to undergo interfacial transfer, and finally leads to the increase of photocatalytic activity. The simulation showed that the temperature had a more complicated effect, as it can simultaneously change the activation of electrons, the interfacial transfer of holes, and the interfacial transfer of electrons. It was shown that the interfacial transfer of holes might play a main role at low temperature, with the temperature-dependence of QY

  20. Hydrophobically modified chitosan: a bio-based material for antimicrobial active film.

    PubMed

    Inta, Orathai; Yoksan, Rangrong; Limtrakul, Jumras

    2014-09-01

    The objective of the present research was to improve the hydrophobicity of chitosan, while retaining its antibacterial activity, through the grafting of dodecenyl succinyl chains onto phthaloyl chitosan, mainly at the C-6 position. Dodecenyl succinylated phthaloyl chitosan (DS-g-PHCTS) was synthesized via phthaloylation-dodecenyl succinylation-hydrazinolysis. The obtained derivatives were characterized by FTIR, (1)H NMR and XRD. Hydrazinolysis time was found to be a key factor in controlling the substitution of dodecenyl succinyl chains and phthalimido groups of the final product. DS-g-PHCTS - with a grafting degree of dodecenyl succinyl chains and a substitution degree of phthalimido groups of 0.73 and 0.39, respectively - exhibited an anhydrous crystal structure and the same solubility behavior as native chitosan. The introduction of hydrophobic alkyl chains provided DS-g-PHCTS with enhanced antibacterial activity against Gram-positive bacteria. In addition, DS-g-PHCTS film showed more effective bacterial growth inhibition and better water vapor barrier property under neutral pH condition than chitosan film. The results suggested that DS-g-PHCTS film could be potentially used as antibacterial active film.

  1. Process for forming a homogeneous oxide solid phase of catalytically active material

    DOEpatents

    Perry, Dale L.; Russo, Richard E.; Mao, Xianglei

    1995-01-01

    A process is disclosed for forming a homogeneous oxide solid phase reaction product of catalytically active material comprising one or more alkali metals, one or more alkaline earth metals, and one or more Group VIII transition metals. The process comprises reacting together one or more alkali metal oxides and/or salts, one or more alkaline earth metal oxides and/or salts, one or more Group VIII transition metal oxides and/or salts, capable of forming a catalytically active reaction product, in the optional presence of an additional source of oxygen, using a laser beam to ablate from a target such metal compound reactants in the form of a vapor in a deposition chamber, resulting in the deposition, on a heated substrate in the chamber, of the desired oxide phase reaction product. The resulting product may be formed in variable, but reproducible, stoichiometric ratios. The homogeneous oxide solid phase product is useful as a catalyst, and can be produced in many physical forms, including thin films, particulate forms, coatings on catalyst support structures, and coatings on structures used in reaction apparatus in which the reaction product of the invention will serve as a catalyst.

  2. Electric field responsive origami structures using electrostriction-based active materials

    NASA Astrophysics Data System (ADS)

    Ahmed, Saad; Arrojado, Erika; Sigamani, Nirmal; Ounaies, Zoubeida

    2015-04-01

    The objective of origami engineering is to combine origami principles with advanced materials to yield active origami shapes, which fold and unfold in response to external stimuli. We are investigating the use of P(VDF-TrFE-CTFE), a relaxor ferroelectric terpolymer, to realize origami-inspired folding and unfolding of structures and to actuate so-called action origami structures. To accomplish these two objectives, we have explored different approaches to the P(VDF-TrFECTFE) polymer actuator construction, ranging from unimorph to multilayered stacks. Electromechanical characterization of the terpolymer-based actuators is conducted with a focus on free strain, force-displacement and blocked force. Moreover dynamic thickness strains of P(VDF-TrFE-CTFE) terpolymer at different frequencies ranging from 0.1Hz to 10Hz is also measured. Quantifying the performance of terpolymer-based actuators is important to the design of action origami structures. Following these studies, action origami prototypes based on catapult, flapping butterfly wings and barking fox are actuated and characterization of these prototypes are conducted by studying impact of various parameters such as electric field magnitude and frequency, number of active layers, and actuator dimensions.

  3. Electrospun carbon nanofibers from polyacrylonitrile blended with activated or graphitized carbonaceous materials for improving anodic bioelectrocatalysis.

    PubMed

    Patil, Sunil A; Chigome, Samuel; Hägerhäll, Cecilia; Torto, Nelson; Gorton, Lo

    2013-03-01

    The electrospun carbon nanofibers obtained from polyacrylonitrile (PAN) and PAN blends with either activated carbon (PAN-AC) or graphite (PAN-GR) were tested as anodes using Shewanella oneidensis MR-1. Extensive physico-chemical and electrochemical characterization confirmed their formation, their fibrous and porous nature, and their suitability as electrodes. N2 adsorption measurements revealed high specific surface area (229.8, 415.8 and 485.2m(2) g(-1)) and porosity (0.142, 0.202 and 0.239cm(3)g(-1)) for PAN, PAN-AC and PAN-GR, respectively. The chronoamperometric measurements showed a considerable decrease in start-up time and more than a 10-fold increase in the generation of current with these electrodes (115, 139 and 155μAcm(-2) for PAN, PAN-AC and PAN-GR, respectively) compared to the graphite electrode (11.5μAcm(-2)). These results indicate that the bioelectrocatalysis benefits from the blending of PAN with activated or graphitized carbonaceous materials, presumably due to the increased specific surface area, total pore volume and modification of the carbon microstructure. PMID:23399497

  4. Facile and green synthesis of palladium nanoparticles-graphene-carbon nanotube material with high catalytic activity.

    PubMed

    Sun, Tai; Zhang, Zheye; Xiao, Junwu; Chen, Chen; Xiao, Fei; Wang, Shuai; Liu, Yunqi

    2013-01-01

    We report a facile and green method to synthesize a new type of catalyst by coating Pd nanoparticles (NPs) on reduced graphene oxide (rGO)-carbon nanotube (CNT) nanocomposite. An rGO-CNT nanocomposite with three-dimensional microstructures was obtained by hydrothermal treatment of an aqueous dispersion of graphene oxide (GO) and CNTs. After the rGO-CNT composites have been dipped in K₂PdCl₄ solution, the spontaneous redox reaction between the GO-CNT and PdCl₄(2-) led to the formation of nanohybrid materials consisting rGO-CNT decorated with 4 nm Pd NPs, which exhibited excellent and stable catalytic activity: the reduction of 4-nitrophenol to 4-aminophenol using NaBH4 as a catalyst was completed in only 20 s at room temperature, even when the Pd content of the catalyst was 1.12 wt%. This method does not require rigorous conditions or toxic agents and thus is a rapid, efficient, and green approach to the fabrication of highly active catalysts. PMID:23982312

  5. Neutron-activation analysis of several US Geological Survey and National Bureau of Standards reference materials

    SciTech Connect

    Daly, A.T.

    1981-01-01

    In this work, several US Geological Survey (U.S.G.S.) and National Bureau of Standards (N.B.S.) reference samples have been analyzed in an effort to improve the quality of elemental concentration data available on these materials, so they can be used in a program of verification of factor analysis source resolution procedures. The analyses of these samples were performed by instrumental neutron activation analysis (INAA). The samples analyzed were: U.S.G.S. Green River Shale, N.B.S. 45b Homogeneous River Sediment, U.S.G.S. Analyzed Peridotite N.B.S. 1579 Powdered Lead-based Paint, U.S.G.S. Hawaian Basalt U.S.G.S. Marine Mud, U.S.G.S. Analyzed Cody Shale U.S.G.S. Glass Mountain Rhyolite, N.B.S. Argillaceous Limestone No. 1, and a sample of Spex ultrapure graphite. Neutron activation analysis was employed because of the high sensitivity that can be attained in determining elemental concentrations. Although INAA is a relatively simple method and the reproducibility of the data is good, the method shows some inaccuracies. The basic theory and technique are reviewed in an attempt to show where problems can arise and how they can be dealt with.

  6. Effects of Cycling Conditions of Active Material From Discharged Ni Positive Plates Studied by Inelastic Neutron Scattering Spectroscopy

    NASA Technical Reports Server (NTRS)

    Eckert, Juergen; Varma, Ravi; Diebolt, Lisa; Reid, Margaret

    1998-01-01

    The objectives of this presentation are: identify atomic-level signatures of electrochemical activity of the active material on the Ni positive plates of Ni-H2 batteries, relate finding to cycling conditions and histories, and develop INS spectroscopy as a non-destructive testing technique for the evaluation of Ni-positive plates of Ni-H2 batteries.

  7. Alignment of Synaptic Vesicle Macromolecules with the Macromolecules in Active Zone Material that Direct Vesicle Docking

    PubMed Central

    Xu, Jing; Jung, Jae Hoon; Marshall, Robert M.; McMahan, Uel J.

    2013-01-01

    Synaptic vesicles dock at active zones on the presynaptic plasma membrane of a neuron’s axon terminals as a precondition for fusing with the membrane and releasing their neurotransmitter to mediate synaptic impulse transmission. Typically, docked vesicles are next to aggregates of plasma membrane-bound macromolecules called active zone material (AZM). Electron tomography on tissue sections from fixed and stained axon terminals of active and resting frog neuromuscular junctions has led to the conclusion that undocked vesicles are directed to and held at the docking sites by the successive formation of stable connections between vesicle membrane proteins and proteins in different classes of AZM macromolecules. Using the same nanometer scale 3D imaging technology on appropriately stained frog neuromuscular junctions, we found that ∼10% of a vesicle’s luminal volume is occupied by a radial assembly of elongate macromolecules attached by narrow projections, nubs, to the vesicle membrane at ∼25 sites. The assembly’s chiral, bilateral shape is nearly the same vesicle to vesicle, and nubs, at their sites of connection to the vesicle membrane, are linked to macromolecules that span the membrane. For docked vesicles, the orientation of the assembly’s shape relative to the AZM and the presynaptic membrane is the same vesicle to vesicle, whereas for undocked vesicles it is not. The connection sites of most nubs on the membrane of docked vesicles are paired with the connection sites of the different classes of AZM macromolecules that regulate docking, and the membrane spanning macromolecules linked to these nubs are also attached to the AZM macromolecules. We conclude that the luminal assembly of macromolecules anchors in a particular arrangement vesicle membrane macromolecules, which contain the proteins that connect the vesicles to AZM macromolecules during docking. Undocked vesicles must move in a way that aligns this arrangement with the AZM macromolecules for

  8. Alignment of synaptic vesicle macromolecules with the macromolecules in active zone material that direct vesicle docking.

    PubMed

    Harlow, Mark L; Szule, Joseph A; Xu, Jing; Jung, Jae Hoon; Marshall, Robert M; McMahan, Uel J

    2013-01-01

    Synaptic vesicles dock at active zones on the presynaptic plasma membrane of a neuron's axon terminals as a precondition for fusing with the membrane and releasing their neurotransmitter to mediate synaptic impulse transmission. Typically, docked vesicles are next to aggregates of plasma membrane-bound macromolecules called active zone material (AZM). Electron tomography on tissue sections from fixed and stained axon terminals of active and resting frog neuromuscular junctions has led to the conclusion that undocked vesicles are directed to and held at the docking sites by the successive formation of stable connections between vesicle membrane proteins and proteins in different classes of AZM macromolecules. Using the same nanometer scale 3D imaging technology on appropriately stained frog neuromuscular junctions, we found that ∼10% of a vesicle's luminal volume is occupied by a radial assembly of elongate macromolecules attached by narrow projections, nubs, to the vesicle membrane at ∼25 sites. The assembly's chiral, bilateral shape is nearly the same vesicle to vesicle, and nubs, at their sites of connection to the vesicle membrane, are linked to macromolecules that span the membrane. For docked vesicles, the orientation of the assembly's shape relative to the AZM and the presynaptic membrane is the same vesicle to vesicle, whereas for undocked vesicles it is not. The connection sites of most nubs on the membrane of docked vesicles are paired with the connection sites of the different classes of AZM macromolecules that regulate docking, and the membrane spanning macromolecules linked to these nubs are also attached to the AZM macromolecules. We conclude that the luminal assembly of macromolecules anchors in a particular arrangement vesicle membrane macromolecules, which contain the proteins that connect the vesicles to AZM macromolecules during docking. Undocked vesicles must move in a way that aligns this arrangement with the AZM macromolecules for docking

  9. An Active Smart Material Control System for F/A-18 Buffet Alleviation

    NASA Technical Reports Server (NTRS)

    Sheta, Essam F.; Moses, Robert W.; Huttsell, Lawrence J.; Harrand, Vincent J.

    2003-01-01

    The vertical tail buffet problem of fighter aircraft occurs at high angles of attack when the vortical flow breaks down ahead of the vertical tails resulting in unsteady and unbalanced pressure loads on the vertical tails. The buffet loads imposed upon the vertical tails resulted in a premature fatigue failure of the tails, and consequently limits the performance and super maneuverability of twin-tail fighter aircraft. An active smart material control system using distributed piezoelectric actuators has been developed for buffet alleviation and is presented. The inboard and outboard surfaces of the vertical tail are equipped with piezoelectric actuators to control the buffet responses in the first bending and torsion modes. The electrodynamics of the piezoelectric actuators are expressed with a three-dimensional finite-element model. A single-input-single-output controller is designed to drive the active piezoelectric actuators. High-fidelity multidisciplinary analysis modules for the fluid dynamics, structure dynamics, electrodynamics of the piezoelectric actuators, control law, fluid structure interfacing, and grid motion are integrated into a multidisciplinary computing environment that controls the temporal synchronization of the analysis modules. At 30 degree angle of attack, RMS values of tip acceleration are reduced by as much as 12%. The peak values of the power spectral density of tail-tip acceleration are reduced by as much as 22% in the first bending mode and by as much as 82% in the first torsion mode. The actively controlled piezoelectric actuators were also effective in adding damping at wide range of angles of attack.

  10. Fabrication of a PANI/CPs composite material: a feasible method to enhance the photocatalytic activity of coordination polymers.

    PubMed

    Xu, Xin-Xin; Cui, Zhong-Ping; Qi, Ji; Liu, Xiao-Xia

    2013-03-21

    To improve the photocatalytic activity of a coordination polymer in the visible light region, polyaniline (PANI) was loaded onto its surface through a facile in situ chemical oxidation polymerization process. The resulting PANI loaded coordination polymer composite materials with excellent stability exhibit significantly higher photocatalytic activities than the pure coordination polymer photocatalyst on the degradation of methyl orange (MO) under visible light irradiation. This enhancement can be ascribed to the introduction of PANI on the surface of the coordination polymer, which leads to efficient separation of photogenerated electron-hole pairs as well as a significant expansion of the photoresponse region. Finally, we discussed the influence of acidity on the morphology and photocatalytic activity of the composite material. An optimal condition to obtain the PANI loaded coordination polymer composite material with excellent photocatalytic activity has been obtained.

  11. Sorption of mercury onto waste material derived low-cost activated carbon

    NASA Astrophysics Data System (ADS)

    Bhakta, Jatindra N.; Rana, Sukanta; Lahiri, Susmita; Munekage, Yukihiro

    2014-11-01

    The present study was performed to develop the low-cost activated carbon (AC) from some waste materials as potential mercury (Hg) sorbent to remove high amount of Hg from aqueous phase. The ACs were prepared from banana peel, orange peel, cotton fiber and paper wastes by pyrolysis and characterized by analyzing physico-chemical properties and Hg sorption capacity. The Brunauer Emmett and Teller surface areas (cotton 138 m2/g; paper 119 m2/g), micropore surface areas (cotton 65 m2/g; paper 54 m2/g) and major constituent carbon contents (cotton 95.04 %; paper 94.4 %) were higher in ACs of cotton fiber and paper wastes than the rest two ACs. The Hg sorption capacities and removal percentages were greater in cotton and paper wastes-derived ACs compared to those of the banana and orange peels. The results revealed that elevated Hg removal ability of cotton and paper wastes-derived ACs is largely regulated by their surface area, porosity and carbon content properties. Therefore, ACs of cotton and paper wastes were identified as potential sorbent among four developed ACs to remove high amount of Hg from aqueous phase. Furthermore, easily accessible precursor material, simple preparation process, favorable physico-chemical properties and high Hg sorption capacity indicated that cotton and paper wastes-derived ACs could be used as potential and low-cost sorbents of Hg for applying in practical field to control the severe effect of Hg contamination in the aquatic environment to avoid its human and environmental health risks.

  12. High-power, photofission-inducing bremsstrahlung source for intense pulsed active detection of fissile material

    NASA Astrophysics Data System (ADS)

    Zier, J. C.; Mosher, D.; Allen, R. J.; Commisso, R. J.; Cooperstein, G.; Hinshelwood, D. D.; Jackson, S. L.; Murphy, D. P.; Ottinger, P. F.; Richardson, A. S.; Schumer, J. W.; Swanekamp, S. B.; Weber, B. V.

    2014-06-01

    Intense pulsed active detection (IPAD) is a promising technique for detecting fissile material to prevent the proliferation of special nuclear materials. With IPAD, fissions are induced in a brief, intense radiation burst and the resulting gamma ray or neutron signals are acquired during a short period of elevated signal-to-noise ratio. The 8 MV, 200 kA Mercury pulsed-power generator at the Naval Research Laboratory coupled to a high-power vacuum diode produces an intense 30 ns bremsstrahlung beam to study this approach. The work presented here reports on Mercury experiments designed to maximize the photofission yield in a depleted-uranium (DU) object in the bremsstrahlung far field by varying the anode-cathode (AK) diode gap spacing and by adding an inner-diameter-reducing insert in the outer conductor wall. An extensive suite of diagnostics was fielded to measure the bremsstrahlung beam and DU fission yield as functions of diode geometry. Delayed fission neutrons from the DU proved to be a valuable diagnostic for measuring bremsstrahlung photons above 5 MeV. The measurements are in broad agreement with particle-in-cell and Monte Carlo simulations of electron dynamics and radiation transport. These show that with increasing AK gap, electron losses to the insert and outer conductor wall increase and that the electron angles impacting the bremsstrahlung converter approach normal incidence. The diode conditions for maximum fission yield occur when the gap is large enough to produce electron angles close to normal, yet small enough to limit electron losses.

  13. Gamma/neutron time-correlation for special nuclear material detection – Active stimulation of highly enriched uranium

    SciTech Connect

    Paff, Marc G.; Monterial, Mateusz; Marleau, Peter; Kiff, Scott; Nowack, Aaron; Clarke, Shaun D.; Pozzi, Sara A.

    2014-06-21

    A series of simulations and experiments were undertaken to explore and evaluate the potential for a novel new technique for fissile material detection and characterization, the timecorrelated pulse-height (TCPH) method, to be used concurrent with active stimulation of potential nuclear materials. In previous work TCPH has been established as a highly sensitive method for the detection and characterization of configurations of fissile material containing Plutonium in passive measurements. By actively stimulating fission with the introduction of an external radiation source, we have shown that TCPH is also an effective method of detecting and characterizing configurations of fissile material containing Highly Enriched Uranium (HEU). The TCPH method is shown to be robust in the presence of the proper choice of external radiation source. An evaluation of potential interrogation sources is presented.

  14. Gamma/neutron time-correlation for special nuclear material detection – Active stimulation of highly enriched uranium

    DOE PAGES

    Paff, Marc G.; Monterial, Mateusz; Marleau, Peter; Kiff, Scott; Nowack, Aaron; Clarke, Shaun D.; Pozzi, Sara A.

    2014-06-21

    A series of simulations and experiments were undertaken to explore and evaluate the potential for a novel new technique for fissile material detection and characterization, the timecorrelated pulse-height (TCPH) method, to be used concurrent with active stimulation of potential nuclear materials. In previous work TCPH has been established as a highly sensitive method for the detection and characterization of configurations of fissile material containing Plutonium in passive measurements. By actively stimulating fission with the introduction of an external radiation source, we have shown that TCPH is also an effective method of detecting and characterizing configurations of fissile material containing Highlymore » Enriched Uranium (HEU). The TCPH method is shown to be robust in the presence of the proper choice of external radiation source. An evaluation of potential interrogation sources is presented.« less

  15. Oxygen reduction and evolution at single-metal active sites: Comparison between functionalized graphitic materials and protoporphyrins

    NASA Astrophysics Data System (ADS)

    Calle-Vallejo, F.; Martínez, J. I.; García-Lastra, J. M.; Abad, E.; Koper, M. T. M.

    2013-01-01

    A worldwide spread of clean technologies such as low-temperature fuel cells and electrolyzers depends strictly on their technical reliability and economic affordability. Currently, both conditions are hardly fulfilled mainly due to the same reason: the oxygen electrode, which has large overpotentials and is made of precious materials. A possible solution is the use of non-noble electrocatalysts with single-metal active sites. Here, on the basis of DFT calculations of adsorbed intermediates and a thermodynamic analysis, we compare the oxygen reduction (ORR) and evolution (OER) activities of functionalized graphitic materials and gas-phase porphyrins with late transition metals. We find that both kinds of materials follow approximately the same activity trends, and active sites with transition metals from groups 7 to 9 may be good ORR and OER electrocatalysts. However, spin analyses show more flexibility in the possible oxidation states of the metal atoms in solid electrocatalysts, while in porphyrins they must be + 2. These observations reveal that the catalytic activity of these materials is mainly due to nearest-neighbor interactions. Based on this, we propose that this class of electrocatalysts may be improved by careful selections of the support and the ligand properties close to the active sites and/or the ramifications near them, so that charge is transferred back and forth during adsorption and selective hydrogen bonds are formed.

  16. IFMIF, International Fusion Materials Irradiation Facility conceptual design activity cost report

    SciTech Connect

    Rennich, M.J.

    1996-12-01

    This report documents the cost estimate for the International Fusion Materials Irradiation Facility (IFMIF) at the completion of the Conceptual Design Activity (CDA). The estimate corresponds to the design documented in the Final IFMIF CDA Report. In order to effectively involve all the collaborating parties in the development of the estimate, a preparatory meeting was held at Oak Ridge National Laboratory in March 1996 to jointly establish guidelines to insure that the estimate was uniformly prepared while still permitting each country to use customary costing techniques. These guidelines are described in Section 4. A preliminary cost estimate was issued in July 1996 based on the results of the Second Design Integration Meeting, May 20--27, 1996 at JAERI, Tokai, Japan. This document served as the basis for the final costing and review efforts culminating in a final review during the Third IFMIF Design Integration Meeting, October 14--25, 1996, ENEA, Frascati, Italy. The present estimate is a baseline cost estimate which does not apply to a specific site. A revised cost estimate will be prepared following the assignment of both the site and all the facility responsibilities.

  17. Active Inspection of Nuclear Materials Using {sup 4}He Scintillation Detectors

    SciTech Connect

    Davatz, G.; Howard, A.; Chandra, R.; Gendotti, U.

    2011-12-13

    The detection of fissionable materials by neutron and high-energy photon active interrogation methods is explored using {sup 4}He scintillation detectors to search for prompt and delayed neutron signature. The low electron density of {sup 4}He in addition to its pulse shape discrimination capability allows strong rejection of gamma radiation. For the detection of the prompt neutron signatures, this capability is important as the signal produced by induced fission is accompanied by intense gamma radiation. The nanosecond time resolution of {sup 4}He scintillation detectors can be used for time-of-flight measurements aimed at determining the energy of the emitted neutrons. For delayed neutron detection, the insensitivity to the low energy neutrons present from non-signal reactions is inherent. Unlike detectors requiring a moderator, this technology can easily be collimated to reduce sensitivity to neutrons from outside the field of interest. The performance of the detectors for these applications is studied using GEANT4 computer modeling, based on measured detector parameters. A comparison is made with technologies typically used for these applications, i.e. heavily shielded organic scintillators for prompt neutron detection and Cd-lined {sup 3}He neutron detectors for the detection of delayed neutrons.

  18. Electrospun conducting polymer nanofibers as the active material in sensors and diodes

    NASA Astrophysics Data System (ADS)

    Pinto, Nicholas J.

    2013-03-01

    Polyaniline doped with camphorsulfonic acid (PANi-HCSA) and poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSSA) were electrospun separately to obtain individual nanofibers which were captured on Si/SiO2 substrates and electrically characterized. The fiber resistance was recorded as a function of time in the presence of vapours of aliphatic alcohols of varying sizes. Due to the large surface to volume ratio, uniform diameter and small quantity of active material used in the construction, these sensor responses are very quick. Sensors made from individual fibers also show true saturation upon exposure to and removal of the sensing gas. A Schottky diode was also fabricated using an n-doped Si/SiO2 substrate and a single PANi-HCSA fiber and tested in vacuum and in ammonia gas. The diode response was instantaneous upon exposure to ammonia with nearly complete recovery of the current upon pumping out the ammonia, thereby making it a reusable sensor with rectifying behaviour i.e. multifunctional.

  19. Fouling-release and chemical activity effects of a siloxane-based material on tunicates.

    PubMed

    Filip, Natalia; Pustam, Amanda; Ells, Veronica; Grosicki, Kathleen M T; Yang, Jin; Oguejiofor, Ikenna; Bishop, Cory D; DeMont, M Edwin; Smith-Palmer, Truis; Wyeth, Russell C

    2016-05-01

    The antifouling performance of a siloxane-based elastomeric impression material (EIM) was compared to that of two silicone fouling-release coatings, Intersleek 757 and RTV-11. In field immersion trials, the EIM caused the greatest reduction in fouling by the solitary tunicate Ciona intestinalis and caused the longest delay in the progression of fouling by two species of colonial tunicate. However, in pseudobarnacle adhesion tests, the EIM had higher attachment strengths. Further laboratory analyses showed that the EIM leached alkylphenol ethoxylates (APEs) that were toxic to C. intestinalis larvae. The EIM thus showed the longest duration of chemical activity measured to date for a siloxane-based coating (4 months), supporting investigations of fouling-release coatings that release targeted biocides. However, due to potential widespread effects of APEs, the current EIM formulation should not be considered as an environmentally-safe antifoulant. Thus, the data also emphasize consideration of both immediate and long-term effects of potentially toxic constituents released from fouling-release coatings. PMID:26986763

  20. The importance of the active surface area of graphite materials in the first lithium intercalation

    NASA Astrophysics Data System (ADS)

    Novák, P.; Ufheil, J.; Buqa, H.; Krumeich, F.; Spahr, M. E.; Goers, D.; Wilhelm, H.; Dentzer, J.; Gadiou, R.; Vix-Guterl, C.

    When lithium is intercalated into graphite in ethylene carbonate (EC) containing electrolytes, solvent co-intercalation leading to the exfoliation of the graphite structure could occur. The exfoliation can be suppressed if an efficient solid electrolyte interphase (SEI, a passivation layer) is formed. Here we study the role played by the active surface area (ASA) of graphite materials during their first electrochemical reduction. ASA (related to the presence of defects at the carbon surface) appears as a critical graphite surface parameter influencing the surface passivation mechanism and the graphite exfoliation. The ASA of TIMREX ® SLX50 synthetic graphite was modified by thermal treatment in argon and air. The electrochemical performance was characterized in 1 M LiPF 6, EC:DMC electrolyte and post mortem analyses were performed by SEM imaging. It turned out that a decrease of the graphite ASA, i.e., an increase of the graphite structural order, hinders the formation of the passivation layer and favors the exfoliation process. In contrast, the exfoliation of the same graphite can be suppressed if its ASA is increased for example by air treatment. The ASA of the graphite kinetically controls the formation of an efficient SEI film and accordingly the irreversible charge loss is much lower in the case of graphite with a high ASA value.

  1. Integration of electronics and photonics in active material by femtosecond laser for functional microdevice fabrication

    NASA Astrophysics Data System (ADS)

    Cheng, Ya; Xu, Zhizhan; Sugioka, Koji; Midorikawa, Katsumi

    2010-02-01

    Recently, hybrid integration of multifunctional micro-components for creating complex, intelligent micro/nano systems has attracted significant attention. These micro/nano systems have important applications in a variety of areas, such as healthcare, environment, communication, national security, and so on. Until now, fabrication of micro/nano systems incorporated with different functions is still a challenging issue, which generally requires fabrication of microcomponents beforehand followed by assembly and packaging procedures. Thus, the fabrication process is complex and costly. In recent years, the rapid development of femtosecond laser microfabrication technology has enabled direct fabrication and integration of multifunctional components, such as microfluidics, microoptics, micromechanics, microelectronics, etc., into a substrate. Particularly, in this talk, we show the use of femtosecond laser microfabrication for integrating microelectronics and microphotonics. Both microelectrodes and optical waveguides can be directly embedded in active materials after a femtosecond laser direct writing followed by electroless chemical plating. As examples, electric-optic (EO) modulators were fabricated in lithium niobate (LiNbO3) crystal and their functions were demonstrated.

  2. Determination of multielements in a typical Japanese diet certified reference material by instrumental neutron activation analysis.

    PubMed

    Suzuki, Shogo; Okada, Yukiko; Hirai, Shoji

    2003-08-01

    Multielements in a typical Japanese diet certified reference material prepared at the National Institute for Environmental Studies (NIES) of Japan, in collaboration with the National Institute of Radiological Sciences (NIRS) of Japan were determined by instrumental neutron activation analysis (INAA). Five samples (ca. 510-1000 mg) and comparative standards were irradiated for a short time (10 s) at a thermal neutron flux of 1.5 x 10(12) n cm(-2) s(-1) (pneumatic transfer) and for a long time (6 h) at a thermal neutron flux of 3.7 x 10(12) n cm(-2) s(-1) (central thimble) in the Rikkyo University Research Reactor (TRIGA Mark-II, 100 kW). The irradiated samples were measured by conventional gama-ray spectrometry using a coaxial Ge detector, and by anti-coincidence and coincidence gamma-ray spectrometry with a coaxial Ge detector and a well-type NaI(Tl) detector. The concentrations of 38 elements were determined by these methods. PMID:12945682

  3. Study of multi-layer active magnetic regenerators using magnetocaloric materials with first and second order phase transition

    NASA Astrophysics Data System (ADS)

    Lei, T.; Engelbrecht, K.; Nielsen, K. K.; Neves Bez, H.; Bahl, C. R. H.

    2016-09-01

    Magnetocaloric materials (MCM) with a first order phase transition (FOPT) usually exhibit a large, although sharp, isothermal entropy change near their Curie temperature, compared to materials with a second order phase transition (SOPT). Experimental results of applying FOPT materials in recent magnetocaloric refrigerators (MCR) demonstrated the great potential for these materials, but a thorough study on the impact of the moderate adiabatic temperature change and strong temperature dependence of the magnetocaloric effect (MCE) is lacking. Besides, comparing active magnetic regenerators (AMR) using FOPT and SOPT materials is also of fundamental interest. We present modeling results of multi-layer AMRs using FOPT and SOPT materials based on a 1D numerical model. First the impact of isothermal entropy change, adiabatic temperature change and shape factor describing the temperature dependence of the MCE are quantified and analyzed by using artificially built magnetocaloric properties. Then, based on measured magnetocaloric properties of La(Fe,Mn,Si)13H y and Gd, an investigation on how to layer typical FOPT and SOPT materials with different temperature spans is carried out. Moreover, the sensitivity of variation in Curie temperature distribution for both groups of AMRs is investigated. Finally, a concept of mixing FOPT and SOPT materials is studied for improving the stability of layered AMRs with existing materials.

  4. Introducing the potential of antimicrobial materials for human and robotic spaceflight activities

    NASA Astrophysics Data System (ADS)

    Hahn, Claudia; Reitz, Guenther; Moeller, Ralf; Rettberg, Petra; Hans, Michael; Muecklich, Frank

    their relative short reaction time, long efficiency and functionality, broad application to reduce (micro-)biological contamination, high inactivation rates, sustainability, and avoidance of microbial resistance. Methods like contact killing measurement are one of the reliable ways to examine the effect of metal surfaces on the inactivation of microorganisms. We conducted contact killing experiments, in which we exposed human-associated microorganisms like Escherichia coli and Staphylococcus sp. on copper and stainless steel to detect and evaluate the potential incorporation of those materials in future spacecraft components. In contrast to an exposure on stainless steel microorganisms exposed on copper died within a few hours and therefore do not have the ability to proliferate, build protecting biofilms or even survive. The application of different surfaces and antimicrobial substances such as copper and silver, as well as testing other model organisms are still under examination. The results of our experiments are also very promising to other research areas, e.g., clinical application. Here, we would like to present our first data and ideas on the utilization of antimicrobial metal-based surfaces for human and robotic spaceflight activities as a beneficial method to reduce microbial contamination. \\underline{References} Horneck G et al. (2010) Space microbiology. Microbiol. Mol. Biol. Rev. 74:121-156. Vaishampayan P et al. (2013) New perspectives on viable microbial communities in low-biomass cleanroom environments. ISME J. 7:312-324. van Houdt R et al. (2012) Microbial contamination monitoring and control during human space missions. Planet. Space Sci. 60:115-120.

  5. Surface activity and film formation from the surface associated material of artificial surfactant preparations.

    PubMed

    Palmblad, M; Gustafsson, M; Curstedt, T; Johansson, J; Schürch, S

    2001-02-01

    Surfactant proteins B and C (SP-B and SP-C) are present in natural derived surfactant preparations used for treatment of respiratory distress syndrome. Herein the surface activity of an SP-C analogue (SP-C(LKS)), a hybrid peptide between SP-C and bacteriorhodopsin (SP-C/BR) and a model peptide (KL(4)) was studied with a captive bubble surfactometer (CBS). The peptides were mixed with either 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/phosphatidylglycerol (PG) (7:3, by weight) or DPPC/PG/palmitic acid (68:22:9, by weight) at a concentration of 1 mg/ml in HEPES buffer, pH 6.9 and a polypeptide/lipid weight ratio of 0.02--0.03. In some lipid/peptide preparations also 2% of SP-B was included. Adsorption, monitored as surface tension vs. time for 10 min after bubble formation did not show discernible differences for the whole set of preparations. Equilibrium surface tensions of approximately 25 mN/m were reached after 5--10 min for all preparations, although those with SP-C/BR appeared not to reach end point of adsorption within 10 min. Area compression needed to reach minimum surface tension of 0.5--2.0 mN/m was least for the KL(4) preparation, about 13% in the first cycle. 3% SP-C(LKS) in DPPC:PG (7:3, by weight) reached minimum surface tension upon 27% compression in the first cycle. If DPPC:PG:PA (68:22:9, by weight) was used instead only 16% area compression was needed and 14% if also 2% SP-B was included. 3% SP-C(LKS) in DPPC:PG (7:3, by weight)+2% SP-B needed 34% compression to reach minimum surface tension. The replenishment of material from a surface associated surfactant reservoir was estimated with subphase depletion experiments. With the 2% KL(4) preparation incorporation of excess material took place at a surface tension of 25--35 mN/m during stepwise bubble expansion and excess material equivalent to 4.3 monolayers was found. When 2% SP-B was added to 3% SP-C(LKS) in DPPC:PG (7:3, by weight) the number of excess monolayers increased from 1.5 to 3

  6. Nondestructive activation analysis of sample of lunar surface material returned by Luna 16 automatic station. [chemical composition

    NASA Technical Reports Server (NTRS)

    Chayko, M.; Sabo, E.

    1974-01-01

    The composition of a sample of lunar surface material returned by the Luna 16 automatic station from the Sea of Fertility was studied, using nondestructive activation analysis. The structure of the returned surface material is inhomogeneous; the surficial material is thin, quite homogeneous, and the granularity increases with depth. Based on grain size, the sample was separated into five zones. The activation analysis was conducted on a sample taken from the friable surficial layer, zone A. The content of Al, Mn, Na, Cr, Co, Fe, and Sc was determined by nondestructive activation analysis of the sample. In determining Cr, Co, Fe, and Sc, the sample was irradiated for 24 hours and cooled for 10 days. Gamma spectra of the samples were recorded with a semiconductor Ge(Li)-detector and a multichannel analyzer, and measurement data were processed with an electronic computer.

  7. Postassembly Transformation of a Catalytically Active Composite Material, Pt@ZIF-8, via Solvent-Assisted Linker Exchange.

    PubMed

    Stephenson, Casey J; Hupp, Joseph T; Farha, Omar K

    2016-02-15

    2-Methylimidazolate linkers of Pt@ZIF-8 are exchanged with imidazolate using solvent-assisted linker exchange (SALE) to expand the apertures of the parent material and create Pt@SALEM-2. Characterization of the material before and after SALE was performed. Both materials are active as catalysts for the hydrogenation of 1-octene, whereas the hydrogenation of cis-cyclohexene occurred only with Pt@SALEM-2, consistent with larger apertures for the daughter material. The largest substrate, β-pinene, proved to be unreactive with H2 when either material was employed as a candidate catalyst, supporting the contention that substrate molecules, for both composites, must traverse the metal-organic framework component in order to reach the catalytic nanoparticles.

  8. A chamber study on the reactions of O3, NO, NO2 and selected VOCs with a photocatalytically active cementitious coating material.

    PubMed

    Mothes, F; Böge, O; Herrmann, H

    2016-08-01

    Chamber studies were performed to investigate the efficiency of a photocatalytically active cementitious coating material to depollute contaminated air. The results showed a photocatalytic effect on ozone (O3), proven by an increase of the geometric uptake coefficient from 5.2 × 10(-6) for the inactive to 7.7 × 10(-6) for the active material under irradiation. Measured first-order rate constants for nitrogen oxides (NOx) under irradiation are in the range of 2.6-5.9 × 10(-4) s(-1), which is significantly higher compared to the inactive material (7.3-9.7 × 10(-5) s(-1)) demonstrating the photocatalytic effect. However, no significant photocatalytic degradation was observed for the studied volatile organic compounds (VOCs) toluene and isoprene resulting in only an upper limit uptake coefficient of 5.0 × 10(-7) for both VOCs. In all experiments using the photocatalytically active material, a clear formation of small carbonyl (C1-C5) gas phase compounds was identified which is suggested to result from the photocatalytic degradation of organic additives. In contrast to the uptake observed for pure O3, during the experiments with NOx (≥50 % relative humidity), a clear photocatalytic formation of O3 was observed. For the material investigated, an empirically derived overall zero-order rate constant of k 0 (O3) ≈ 5 × 10(7) molecules cm(-3) s(-1) was determined. The results demonstrate the necessity of detailed studies of heterogeneous reactions on such surfaces under more complex simulated atmospheric conditions as enabled by simulation chambers.

  9. A chamber study on the reactions of O3, NO, NO2 and selected VOCs with a photocatalytically active cementitious coating material.

    PubMed

    Mothes, F; Böge, O; Herrmann, H

    2016-08-01

    Chamber studies were performed to investigate the efficiency of a photocatalytically active cementitious coating material to depollute contaminated air. The results showed a photocatalytic effect on ozone (O3), proven by an increase of the geometric uptake coefficient from 5.2 × 10(-6) for the inactive to 7.7 × 10(-6) for the active material under irradiation. Measured first-order rate constants for nitrogen oxides (NOx) under irradiation are in the range of 2.6-5.9 × 10(-4) s(-1), which is significantly higher compared to the inactive material (7.3-9.7 × 10(-5) s(-1)) demonstrating the photocatalytic effect. However, no significant photocatalytic degradation was observed for the studied volatile organic compounds (VOCs) toluene and isoprene resulting in only an upper limit uptake coefficient of 5.0 × 10(-7) for both VOCs. In all experiments using the photocatalytically active material, a clear formation of small carbonyl (C1-C5) gas phase compounds was identified which is suggested to result from the photocatalytic degradation of organic additives. In contrast to the uptake observed for pure O3, during the experiments with NOx (≥50 % relative humidity), a clear photocatalytic formation of O3 was observed. For the material investigated, an empirically derived overall zero-order rate constant of k 0 (O3) ≈ 5 × 10(7) molecules cm(-3) s(-1) was determined. The results demonstrate the necessity of detailed studies of heterogeneous reactions on such surfaces under more complex simulated atmospheric conditions as enabled by simulation chambers. PMID:27102618

  10. Career Development Guidelines. A Handbook for Program Planning and Review--Five Phases Focusing on Individual Student Competencies with Suggested Activities and Counselor-Team Counseling and Placement Program Strategies, for All Students 9-12.

    ERIC Educational Resources Information Center

    Colorado State Community Coll. and Occupational Education System, Denver.

    This handbook is designed to help counselors take leadership in providing comprehensive career development activities for students in grades 9-12. The guidelines are intended as a tool for counselors to use in working with their colleagues to develop realistic and workable counseling and placement program strategies. A five-phase schema is…

  11. Fluidisation and plastic activity in a model soft-glassy material flowing in micro-channels with rough walls

    NASA Astrophysics Data System (ADS)

    Scagliarini, A.; Lulli, M.; Sbragaglia, M.; Bernaschi, M.

    2016-06-01

    By means of mesoscopic numerical simulations of a model soft-glassy material, we investigate the role of boundary roughness on the flow behaviour of the material, probing the bulk/wall and global/local rheologies. We show that the roughness reduces the wall slip induced by wettability properties and acts as a source of fluidisation for the material. A direct inspection of the plastic events suggests that their rate of occurrence grows with the fluidity field, reconciling our simulations with kinetic elasto-plastic descriptions of jammed materials. Notwithstanding, we observe qualitative and quantitative differences in the scaling, depending on the distance from the rough wall and on the imposed shear. The impact of roughness on the orientational statistics is also studied.

  12. Hexagonal nanorods of tungsten trioxide: Synthesis, structure, electrochemical properties and activity as supporting material in electrocatalysis

    NASA Astrophysics Data System (ADS)

    Salmaoui, Samiha; Sediri, Faouzi; Gharbi, Néji; Perruchot, Christian; Aeiyach, Salah; Rutkowska, Iwona A.; Kulesza, Pawel J.; Jouini, Mohamed

    2011-07-01

    Tungsten trioxide, unhydrated with hexagonal structure (h-WO 3), has been prepared by hydrothermal method at a temperature of 180 °C in acidified sodium tungstate solution. Thus prepared h-WO 3 has been characterized by X-ray diffraction (XRD) method and using electrochemical techniques. The morphology has been examined by scanning and transmission electron microscopies (SEM and TEM) and it is consistent with existence of nanorods of 50-70 nm diameter and up to 5 μm length. Cyclic voltammetric characterization of thin films of h-WO 3 nanorods has revealed reversible redox behaviour with charge-discharge cycling corresponding to the reversible lithium intercalation/deintercalation into the crystal lattice of the h-WO 3 nanorods. In propylene carbonate containing LiClO 4, two successive redox processes of hexagonal WO 3 nanorods are observed at the scan rate of 50 mV/s. Such behaviour shall be attributed to the presence of at least two W atoms of different surroundings in the lattice structure of h-WO 3 nanorods. On the other hand, in aqueous LiClO 4 solution, only one redox process is observed at the scan rate of 10 mV/s. The above observations can be explained in terms of differences in the diffusion of ions inside two types of channel cavities existing in the structure of the h-WO 3 nanorods. Moreover, the material can be applied as active support for the catalytic bi-metallic Pt-Ru nanoparticles during electrooxidation of ethanol in acid medium (0.5 mol dm -3 H 2SO 4).

  13. MCM-41 supported 12-tungstophosphoric acid mesoporous materials: Preparation, characterization, and catalytic activities for benzaldehyde oxidation with H2O2

    NASA Astrophysics Data System (ADS)

    Chen, Ya; Zhang, Xiao-Li; Chen, Xi; Dong, Bei-Bei; Zheng, Xiu-Cheng

    2013-10-01

    Mesoporous molecular sieves MCM-41 and bulk 12-tungstophosphoric acid (HPW) were synthesized and employed to prepare 5-45 wt.% HPW/MCM-41 mesoporous materials. Characterization results suggested the good dispersion of HPW within MCM-41 when the loading of HPW was less than 35 wt.% and HPW/MCM-41 retained the typical mesopore structure of the supports. The results of the catalytic oxidation of benzaldehyde to benzoic acid with 30% H2O2, in the absence of any organic solvent and co-catalysts, indicated that HPW/MCM-41 was an efficient catalyst and 30 wt.% HPW/MCM-41 sample exhibited the highest catalytic activity among these materials.

  14. Prevalence of human cell material: DNA and RNA profiling of public and private objects and after activity scenarios.

    PubMed

    van den Berge, M; Ozcanhan, G; Zijlstra, S; Lindenbergh, A; Sijen, T

    2016-03-01

    Especially when minute evidentiary traces are analysed, background cell material unrelated to the crime may contribute to detectable levels in the genetic analyses. To gain understanding on the composition of human cell material residing on surfaces contributing to background traces, we performed DNA and mRNA profiling on samplings of various items. Samples were selected by considering events contributing to cell material deposits in exemplary activities (e.g. dragging a person by the trouser ankles), and can be grouped as public objects, private samples, transfer-related samples and washing machine experiments. Results show that high DNA yields do not necessarily relate to an increased number of contributors or to the detection of other cell types than skin. Background cellular material may be found on any type of public or private item. When a major contributor can be deduced in DNA profiles from private items, this can be a different person than the owner of the item. Also when a specific activity is performed and the areas of physical contact are analysed, the "perpetrator" does not necessarily represent the major contributor in the STR profile. Washing machine experiments show that transfer and persistence during laundry is limited for DNA and cell type dependent for RNA. Skin conditions such as the presence of sebum or sweat can promote DNA transfer. Results of this study, which encompasses 549 samples, increase our understanding regarding the prevalence of human cell material in background and activity scenarios.

  15. Gasification characteristics of an activated carbon catalyst during the decomposition of hazardous waste material in supercritical water

    SciTech Connect

    Matsumura, Yukihiko; Nuessle, F.W.; Antal, M.J. Jr.

    1996-12-31

    Recently, carbonaceous materials including activated carbon were proven to be effective catalysts for hazardous waste gasification in supercritical water. Using coconut shell activated carbon catalyst, complete decomposition of industrial organic wastes including methanol and acetic acid was achieved. During this process, the total mass of the activated carbon catalyst changes by two competing processes: a decrease in weight via gasification of the carbon by supercritical water, or an increase in weight by deposition of carbonaceous materials generated by incomplete gasification of the biomass feedstocks. The deposition of carbonaceous materials does not occur when complete gasification is realized. Gasification of the activated carbon in supercritical water is often favored, resulting in changes in the quality and quantity of the catalyst. To thoroughly understand the hazardous waste decomposition process, a more complete understanding of the behavior of activated carbon in pure supercritical water is needed. The gasification rate of carbon by water vapor at subcritical pressures was studied in relation to coal gasification and generating activated carbon.

  16. Audiovisual Materials and Techniques for Teaching Foreign Languages: Recent Trends and Activities.

    ERIC Educational Resources Information Center

    Parks, Carolyn

    Recent experimentation with audio-visual (A-V) materials has provided insight into the language learning process. Researchers and teachers alike have recognized the importance of using A-V materials to achieve goals related to meaningful and relevant communication, retention and recall of language items, non-verbal aspects of communication, and…

  17. 76 FR 28813 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Material...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... Federal Register on December 3, 2010 (75 FR 75500). Interested parties are encouraged to send comments to...; Material Hoists, Personnel Hoists, and Elevators ACTION: Notice. SUMMARY: The Department of Labor (DOL) is... (ICR) titled, ``Material Hoists, Personnel Hoists, and Elevators,'' to the Office of Management...

  18. Enhanced reactivity of mechanically-activated nano-scale gasless reactive materials consolidated via the cold-spray technique

    NASA Astrophysics Data System (ADS)

    Bacciochini, Antoine; Radulescu, Matei I.; Charron-Tousignant, Yannick; Van Dyke, Jason; Jodoin, Bertrand; Nganbe, Michel; Yandouzi, Mohammed; Lee, Julian

    2012-03-01

    The present study presents a novel method to prepare nano-scale energetic materials with high reactivity, vanishing porosity, structural integrity and arbitrary shape. The experiments have focused on the Ni-Al system. To increase the reactivity, an initial mechanical activation was achieved by the ball milling technique. The consolidation of the materials used the supersonic cold gas spray technique, where the particles are accelerated to high speeds and consolidated via plastic deformation upon impact, forming activated nanocomposites in arbitrary shapes with close to zero porosity. This technique permits to retain the microstructures in the powders and prevents any reactions during the consolidation phase. The material reactivity is addressed through the flame propagation velocity, which showed an increase in the flame speed of the cold sprayed samples by up to one order of magnitude compared to their cold pressed counterparts.

  19. The Effects of Activity and Gain Based Virtual Material on Student's Success, Permanency and Attitudes towards Science Lesson

    ERIC Educational Resources Information Center

    Tas, Erol

    2015-01-01

    The main objective of this study is to research the effects of a student gains and activity based virtual material on students' success, permanence and attitudes towards science lesson, developed for science and technology lesson 6th grade "Systems in our body" unit. The study, which had a quasi-experimental design, was conducted with…

  20. Nano-sized Mn-doped activated carbon aerogel as electrode material for electrochemical capacitor: effect of activation conditions.

    PubMed

    Lee, Yoon Jae; Park, Hai Woong; Park, Sunyoung; Song, In Kyu

    2012-07-01

    Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde, and a series of activated carbon aerogels (ACA-KOH-X, X = 0, 0.3, 0.7, 1, and 2) were then prepared by a chemical activation using different amount of potassium hydroxide (X represented weight ratio of KOH with respect to CA). Specific capacitances of activated carbon aerogels were measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Among the samples prepared, ACA-KOH-0.7 showed the highest specific capacitance (149 F/g). In order to combine excellent electrochemical performance of activated carbon aerogel with pseudocapacitive property of manganese oxide, 7 wt% Mn was doped on activated carbon aerogel (Mn/ACA-KOH-0.7) by an incipient wetness impregnation method. For comparison, 7 wt% Mn was also impregnated on carbon aerogel (Mn/ACA-KOH-0) by the same method. It was revealed that 7 wt% Mn-doped activated carbon aerogel (Mn/ACA-KOH-0.7) showed higher specific capacitance than 7 wt% Mn-doped carbon aerogel (Mn/ACA-KOH-0) (178 F/g vs. 98 F/g). The enhanced capacitance of Mn/ACA-KOH-0.7 was attributed to the outstanding electric properties of activated carbon aerogel as well as the faradaic redox reactions of manganese oxide. PMID:22966708

  1. High in vitro activity of the novel spiropyrimidinetrione AZD0914, a DNA gyrase inhibitor, against multidrug-resistant Neisseria gonorrhoeae isolates suggests a new effective option for oral treatment of gonorrhea.

    PubMed

    Jacobsson, Susanne; Golparian, Daniel; Alm, Richard A; Huband, Michael; Mueller, John; Jensen, Jorgen Skov; Ohnishi, Makoto; Unemo, Magnus

    2014-09-01

    We evaluated the activity of the novel spiropyrimidinetrione AZD0914 (DNA gyrase inhibitor) against clinical gonococcal isolates and international reference strains (n=250), including strains with diverse multidrug resistance and extensive drug resistance. The AZD0914 MICs were substantially lower than those of most other currently or previously recommended antimicrobials. AZD0914 should be further evaluated, including in vitro selection, in vivo emergence and mechanisms of resistance, pharmacokinetics/pharmacodynamics in humans, optimal dosing, and performance, in appropriate randomized and controlled clinical trials. PMID:24982070

  2. Investigation of cell proliferative activity on the surface of the nanocomposite material produced by laser radiation

    NASA Astrophysics Data System (ADS)

    Zhurbina, N. N.; Kurilova, U. E.; Ickitidze, L. P.; Podgaetsky, V. M.; Selishchev, S. V.; Suetina, I. A.; Mezentseva, M. V.; Eganova, E. M.; Pavlov, A. A.; Gerasimenko, A. Y.

    2016-04-01

    A new method for the formation of composite nanomaterials based on multi-walled and single-walled carbon nanotubes (CNT) on a silicon substrate has been developed. Formation is carried out by ultrasound coating of a silicon substrate by homogenous dispersion of CNTs in the albumin matrix and further irradiation with the continuous laser beam with a wavelength of 810 nm and power of 5.5 watts. The high electrical conductivity of CNTs provides its structuring under the influence of the laser radiation electric field. The result is a scaffold that provides high mechanical strength of nanocomposite material (250 MPa). For in vitro studies of materials biocompatibility a method of cell growth microscopic analysis was developed. Human embryonic fibroblasts (EPP) were used as biological cells. Investigation of the interaction between nanocomposite material and cells was carried out by optical and atomic force microscopy depending on the time of cells incubation. The study showed that after 3 hours incubation EPP were fixed on the substrate surface, avoiding the surface of the composite material. However, after 24 hours of incubation EPP fix on the sample surface and then begin to grow and divide. After 72 hours of incubation, the cells completely fill the sample surface of nanocomposite material. Thus, a nanocomposite material based on CNTs in albumin matrix does not inhibit cell growth on its surface, and favours their growth. The nanocomposite material can be used for creating soft tissue implants

  3. Charge carrier transport and lifetimes in n-type and p-type phosphorene as 2D device active materials: an ab initio study

    NASA Astrophysics Data System (ADS)

    Tea, E.; Hin, C.

    In this work, we provide a detailed analysis of phosphorene performance as n-type and p-type active materials. The study is based on first principles calculation of phosphorene electronic structure, and resulting electron and hole scattering rates and lifetimes. Emphasis is put on extreme regimes commonly found in semiconductor devices, i.e. high electric fields and heavy doping, where impact ionization and Auger recombination can occur. We found that electron-initiated impact ionization is weaker than the hole-initiated process, when compared to carrier-phonon interaction rates, suggesting resilience to impact ionization initiated breakdown. Moreover, calculated minority electron lifetimes are limited by radiative recombination only, not by Auger processes, suggesting that phosphorene could achieve good quantum efficiencies in optoelectronic devices. The provided scattering rates and lifetimes are critical input data for the modeling and understanding of phosphorene-based device physics.

  4. Charge carrier transport and lifetimes in n-type and p-type phosphorene as 2D device active materials: an ab initio study.

    PubMed

    Tea, E; Hin, C

    2016-08-10

    In this work, we provide a detailed analysis of phosphorene's performance as an n-type and p-type active material. This study is based on first principles calculations of the phosphorene electronic structure, and the resulting electron and hole scattering rates and lifetimes. Emphasis is put on extreme regimes commonly found in semiconductor devices, i.e. high electric fields and heavy doping, where impact ionization and Auger recombination can occur. We found that electron-initiated impact ionization is weaker than the hole-initiated process, when compared to carrier-phonon interaction rates, suggesting resilience to impact ionization initiated breakdown. Moreover, calculated minority electron lifetimes are limited by radiative recombination only, not by Auger processes, suggesting that phosphorene could achieve good quantum efficiencies in optoelectronic devices. The provided scattering rates and lifetimes are critical input data for the modeling and understanding of phosphorene-based device physics.

  5. Charge carrier transport and lifetimes in n-type and p-type phosphorene as 2D device active materials: an ab initio study.

    PubMed

    Tea, E; Hin, C

    2016-08-10

    In this work, we provide a detailed analysis of phosphorene's performance as an n-type and p-type active material. This study is based on first principles calculations of the phosphorene electronic structure, and the resulting electron and hole scattering rates and lifetimes. Emphasis is put on extreme regimes commonly found in semiconductor devices, i.e. high electric fields and heavy doping, where impact ionization and Auger recombination can occur. We found that electron-initiated impact ionization is weaker than the hole-initiated process, when compared to carrier-phonon interaction rates, suggesting resilience to impact ionization initiated breakdown. Moreover, calculated minority electron lifetimes are limited by radiative recombination only, not by Auger processes, suggesting that phosphorene could achieve good quantum efficiencies in optoelectronic devices. The provided scattering rates and lifetimes are critical input data for the modeling and understanding of phosphorene-based device physics. PMID:27479904

  6. Entrainment in solution of an oscillating NADH oxidase activity from the bovine milk fat globule membrane with a temperature-compensated period length suggestive of an ultradian time-keeping (clock) function

    NASA Technical Reports Server (NTRS)

    Morre, D. James; Lawler, Juliana; Wang, Sui; Keenan, Thomas W.; Morre, Dorothy M.

    2002-01-01

    Entrainment in solution of an oscillating activity with a temperature compensated period of 24 min is described for a NADH oxidase (NOX) activity of the bovine milk fat globule membrane, a derivative of the mammary epithelial cell plasma membrane. The period of 24 min remained unchanged at 17 degrees C, 27 degrees C and 37 degrees C whereas the amplitude approximately doubled with each 10 degree C rise in temperature (Q(10)congruent with 2). The periodicity was observed with both intact milk fat globule membranes and with detergent-solubilized membranes, demonstrating that the oscillations did not require an association with membranes. The periodicity was not the result of instrument variation or of chemical interactions among reactants in solution. Preparations with different periodicities entrained (autosynchronized) when mixed. Upon mixing, the preparations exhibited two oscillatory patterns but eventually a single pattern representing the mean of the farthest separated maxima of the two preparations analyzed separately emerged. The cell surface NOX protein is the first reported example of an entrainable biochemical entity with a temperature-compensated periodicity potentially capable of functioning as an ultradian or circadian clock driver.

  7. Characterisation of the morphogenetic course and secretion of two different types of mucoid material by granulated metrial gland/lymphokine-activated killer cells.

    PubMed

    Dyugovskaya, L; Berkutski, T; Ginsburg, H

    1995-12-01

    Lymphocytes from mesenteric lymph nodes of ordinary and nude mice were grown in microtitre wells on embryonic mesenchymal-fibroblast monolayers. Human recombinant interleukin-2 (80 units ml-1) was added. Clones of lymphokine-activated killer (LAK) cells developed. The incidence of clone-forming cells was 52-136 per 10(5) cells in lymph nodes from nude mice and 4.2-8.3 per 10(5) cells in lymph nodes from ordinary mice. On a limited number of fibroblast monolayers propagated in culture, the maturing LAK cells were induced to synthesise and secrete 2 types of flowing mucoid material. After methanol fixation and Alcian blue/periodic acid-Schiff (PAS) (at pH 1) staining, the first type of material was distinctively stained turquoise, indicating a highly sulphated proteoglycan, chondroitin sulphate; the second type of material, a macromolecular neutral polysaccharide, was not stained and appeared to have been dissolved. Glycogen was stained deep brilliant purple. After treatment with PAS alone, the chondroitin sulphate was not stained and appeared as a bright area, the neutral polysaccharide mass being stained deep red. This polysaccharide material was characteristically secreted as droplets or 'streamlets' emerging from the cell surface and extending through the first type of material to coalesce with the already accumulated main extracellular mucoid layer spreading between the cells. Clones of secretory LAK cells were obtained from gravid and nongravid mouse uteri as well as from tracheal explants. Change of medium or passage with fresh medium to a new inducing batch of monolayer, at the blastoid-large granular lymphocyte stage (on d 3 to 7), was critical for high reproducibility of secretion. The course of differentiation was found ultimately to be dependent on the embryonic mesenchymal monolayer, suggesting induction by a morphogenetic signal. A correlation can be drawn between the secretory activity and the morphological profile at maturation of highly distinctive

  8. EDITORIAL: Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010) Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010)

    NASA Astrophysics Data System (ADS)

    Brei, Diann

    2011-09-01

    The third annual meeting of the AMSE/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) took place in the heart of historic Philadelphia's cultural district, and included a pioneer banquet in the National Constitutional Center. The applications emphasis of the 2010 conference was reflected in keynote talks by Dr Alan Taub, vice president of General Motors global research and development, 'Smart materials in the automotive industry'; Dr Charles R Farrar, engineering institute leader at Los Alamos National Laboratory, 'Future directions for structural health monitoring of civil engineering infrastructure'; and Professor Christopher S Lynch of the University of California Los Angeles, 'Ferroelectric materials and their applications'. The SMASIS conference was divided into six technical symposia each of which included basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. The six symposia were: SYMP 1 Multifunctional Materials; SYMP 2 Active Materials, Mechanics and Behavior; SYMP 3 Modeling, Simulation and Control; SYMP 4 Enabling Technologies and Integrated System Design; SYMP 5 Structural Health Monitoring/NDE; and SYMP 6 Bio-inspired Smart Materials and Structures. In addition, the conference introduced a new student and young professional development symposium. Authors of papers in the materials areas (symposia 1, 2 and 6) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart Materials and Structures. This set of papers demonstrates the exceptional quality and originality of the conference presentations. We are appreciative of their efforts in producing this collection of highly relevant articles on smart materials.

  9. Final report: Photochromism as a switching mechanism for electronically active organic materials

    SciTech Connect

    Pollagi, T.P.; Sinclair, M.B.; Jacobs, S.J.

    1997-07-01

    Recent discoveries in the field of conjugated polymers in environmental stability, regiochemical regularity, and electrical conductivity, particularly of polythiophene and polyaniline, have intensified interest in device applications. Present or anticipated applications include development of electrical circuitry on a molecular scale, as well as conducting and semiconducting materials for a variety of applications including thin film transistors and batteries. The authors have investigated a series of compounds comprising conjugated segments coupled to photochromic elements. The photochromic reaction in these compounds reversibly alters the conjugation length and provides a mechanism for switching both the electrical and optical properties of these materials. The authors are currently investigating the nature and scope of this switching mechanism and preparing extended materials that take advantage of this novel form of switching behavior. Preparation and photochromic behavior of several of these materials are described.

  10. PLA coated paper containing active inorganic nanoparticles: Material characterization and fate of nanoparticles in the paper recycling process.

    PubMed

    Zhang, Hai; Bussini, Daniele; Hortal, Mercedes; Elegir, Graziano; Mendes, Joana; Jordá Beneyto, Maria

    2016-06-01

    For paper and paperboard packaging, recyclability plays an important role in conserving the resources and reducing the environmental impacts. Therefore, when it comes to the nano-enabled paper packaging material, the recyclability issue should be properly addressed. This study represents our first report on the fate of nanomaterials in paper recycling process. The packaging material of concern is a PLA (Polylactic Acid) coated paper incorporating zinc oxide nanoparticles in the coating layer. The material was characterised and assessed in a lab-scale paper recycling line. The recyclability test was based on a method adapted from ATICELCA MC501-13, which enabled to recover over 99% of the solids material. The mass balance result indicates that 86-91% zinc oxide nanoparticles ended up in the rejected material stream, mostly embedded within the polymer coating; whereas 7-16% nanoparticles ended up in the accepted material stream. Besides, the tensile strength of the recycled handsheets suggests that the nano-enabled coating had no negative impacts on the recovered fibre quality.

  11. PLA coated paper containing active inorganic nanoparticles: Material characterization and fate of nanoparticles in the paper recycling process.

    PubMed

    Zhang, Hai; Bussini, Daniele; Hortal, Mercedes; Elegir, Graziano; Mendes, Joana; Jordá Beneyto, Maria

    2016-06-01

    For paper and paperboard packaging, recyclability plays an important role in conserving the resources and reducing the environmental impacts. Therefore, when it comes to the nano-enabled paper packaging material, the recyclability issue should be properly addressed. This study represents our first report on the fate of nanomaterials in paper recycling process. The packaging material of concern is a PLA (Polylactic Acid) coated paper incorporating zinc oxide nanoparticles in the coating layer. The material was characterised and assessed in a lab-scale paper recycling line. The recyclability test was based on a method adapted from ATICELCA MC501-13, which enabled to recover over 99% of the solids material. The mass balance result indicates that 86-91% zinc oxide nanoparticles ended up in the rejected material stream, mostly embedded within the polymer coating; whereas 7-16% nanoparticles ended up in the accepted material stream. Besides, the tensile strength of the recycled handsheets suggests that the nano-enabled coating had no negative impacts on the recovered fibre quality. PMID:27036997

  12. Palladium-containing graphene-like material: Synthesis and catalytic activity

    NASA Astrophysics Data System (ADS)

    Klyuev, M. V.; Arbuzov, A. A.; Magdalinova, N. A.; Kalmykov, P. A.; Tarasov, B. P.

    2016-09-01

    A graphene-like material with surface amine groups is obtained by graphite oxide reduction with ethylenediamine. A catalyst for the hydrogenation of nitrocompounds and unsaturated hydrocarbons is created by depositing Pd nanoparticles on the graphene material. The aliphatic chain is found to prevent agglomeration of the graphene sheets, while the amine groups form the growth centers of palladium nanoparticles, allowing their uniform distribution and small size.

  13. Finite Element Analysis of Active and Sensory Thermopiezoelectric Composite Materials. Degree awarded by Northwestern Univ., Dec. 2000

    NASA Technical Reports Server (NTRS)

    Lee, Ho-Jun

    2001-01-01

    Analytical formulations are developed to account for the coupled mechanical, electrical, and thermal response of piezoelectric composite materials. The coupled response is captured at the material level through the thermopiezoelectric constitutive equations and leads to the inherent capability to model both the sensory and active responses of piezoelectric materials. A layerwise laminate theory is incorporated to provide more accurate analysis of the displacements, strains, stresses, electric fields, and thermal fields through-the-thickness. Thermal effects which arise from coefficient of thermal expansion mismatch, pyroelectric effects, and temperature dependent material properties are explicitly accounted for in the formulation. Corresponding finite element formulations are developed for piezoelectric beam, plate, and shell elements to provide a more generalized capability for the analysis of arbitrary piezoelectric composite structures. The accuracy of the current formulation is verified with comparisons from published experimental data and other analytical models. Additional numerical studies are also conducted to demonstrate additional capabilities of the formulation to represent the sensory and active behaviors. A future plan of experimental studies is provided to characterize the high temperature dynamic response of piezoelectric composite materials.

  14. Economic Development: The Quest for Material Well-Being. Instructional Activities Series IA/S-7.

    ERIC Educational Resources Information Center

    Veal, Willis D.

    This activity is one of a series of 17 teacher-developed instructional activities for geography at the secondary-grade level described in SO 009 140. The activity investigates economic change in developing nations. It employs the dialogue approach. Given data about the Aswan High Dam in Egypt and about the environment of northeast Africa, students…

  15. From Tootsie Rolls to Broken Bones: An Innovative Approach for Active Learning in Mechanics of Materials

    ERIC Educational Resources Information Center

    Linsey, Julie; Talley, Austin; White, Christina; Jensen, Dan; Wood, Kristin

    2009-01-01

    Active learning enhances engineering education. This paper presents rationale, curriculum supplements, and an approach to active learning that may be seamlessly incorporated into a traditional lecture-based engineering class. A framework of educational theory that structures the active learning experiences and includes consideration of learning…

  16. Research activities of the Solid State Sciences Committee in the development of a Federal initiative on advanced materials and processing

    NASA Astrophysics Data System (ADS)

    Taylor, Ronald

    The Solid State Sciences Committee (SSSC) of the National Research Council (NRC) is charged with monitoring the health of the field of materials science in the United States. Accordingly, the committee identifies and examines both broad and specific issues affecting the field. Regular meetings, teleconferences, briefings from agencies and the scientific community, the formation of study panels to prepare reports, and special forums are among the mechanisms used by the SSSC to meet its charge. This progress report presents a review of SSSC activities from May 1, 1992 through April 30, 1993. The details of prior activities are discussed in earlier reports. During the above period, the SSSC has continued to track and participate, when requested, in the development of a federal initiative on advanced materials and processing. Specifically, the SSSC is presently planning the 1993 SSSC Forum (to be cosponsored with the National Materials Advisory Board (NMAB) and the Washington Materials Forum (WMF)). The thrust will be to highlight the Federal Advanced Materials and Processing Program (AMPP). In keeping with its charge to identify and highlight specific areas for scientific and technological opportunities, the SSSC continued to oversee the conduct of a study on biomolecular materials. Preliminary plans also were developed for a study on neutron science; however, further activity is pending. A proposed study on ultrasmall devices has been expanded and absorbed into a broader context; the Board on Physics and Astronomy (BPA), with SSSC participation, is preparing to hold a program initiation meeting to evaluate the need for a study on information technology and hardware.

  17. Poly(L-lactide) and poly(butylene succinate) immiscible blends: from electrospinning to biologically active materials.

    PubMed

    Stoyanova, Nikoleta; Paneva, Dilyana; Mincheva, Rosica; Toncheva, Antoniya; Manolova, Nevena; Dubois, Philippe; Rashkov, Iliya

    2014-08-01

    For the first time the preparation of defect-free fibers from immiscible blends of high molar mass poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) in the whole range of the polyester weight ratios is shown. Electrospinning using the solvent-nonsolvent approach proved most appropriate. Moreover, electrospinning revealed crucial for the obtaining of PLA/PBS materials maintaining integrity. DSC and XRD analyses attested for a plasticizing effect and for increased PLA crystallinity at PBS addition to PLA. The mechanical properties of the PLA/PBS mats were controlled by the alignment of the fibers and changed from plastic to brittle materials upon increasing the PBS content. Drug loading and tests against pathogenic microorganisms suggested that the obtained mats can find application as antibacterial fibrous materials.

  18. Activating point mutations in the common beta subunit of the human GM-CSF, IL-3 and IL-5 receptors suggest the involvement of beta subunit dimerization and cell type-specific molecules in signalling.

    PubMed Central

    Jenkins, B J; D'Andrea, R; Gonda, T J

    1995-01-01

    We have combined retroviral expression cloning with random mutagenesis to identify two activating point mutations in the common signal-transducing subunit (h beta c) of the receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-3 and IL-5 by virtue of their ability to confer factor independence on the haemopoietic cell line, FDC-P1. One mutation (V449E) is located within the transmembrane domain and, by analogy with a similar mutation in the neu oncogene, may act by inducing dimerization of h beta c. The other mutation (I374N) lies in the extracellular, membrane-proximal portion of h beta c. Neither of these mutants, nor a previously described mutant of h beta c (FI delta, which has a small duplication in the extracellular region), was capable of inducing factor independence in CTLL-2 cells, while only V449E could induce factor independence in BAF-B03 cells. These results imply that the extracellular and transmembrane mutations act by different mechanisms. Furthermore, they imply that the mutants, and hence also wild-type h beta c, interact with cell type-specific signalling molecules. Models are presented which illustrate how these mutations may act and predict some of the characteristics of the putative receptor-associated signalling molecules. Images PMID:7556069

  19. Identifying the Atomic-Level Effects of Metal Composition on the Structure and Catalytic Activity of Peptide-Templated Materials.

    PubMed

    Merrill, Nicholas A; McKee, Erik M; Merino, Kyle C; Drummy, Lawrence F; Lee, Sungsik; Reinhart, Benjamin; Ren, Yang; Frenkel, Anatoly I; Naik, Rajesh R; Bedford, Nicholas M; Knecht, Marc R

    2015-12-22

    Bioinspired approaches for the formation of metallic nanomaterials have been extensively employed for a diverse range of applications including diagnostics and catalysis. These materials can often be used under sustainable conditions; however, it is challenging to control the material size, morphology, and composition simultaneously. Here we have employed the R5 peptide, which forms a 3D scaffold to direct the size and linear shape of bimetallic PdAu nanomaterials for catalysis. The materials were prepared at varying Pd:Au ratios to probe optimal compositions to achieve maximal catalytic efficiency. These materials were extensively characterized at the atomic level using transmission electron microscopy, extended X-ray absorption fine structure spectroscopy, and atomic pair distribution function analysis derived from high-energy X-ray diffraction patterns to provide highly resolved structural information. The results confirmed PdAu alloy formation, but also demonstrated that significant surface structural disorder was present. The catalytic activity of the materials was studied for olefin hydrogenation, which demonstrated enhanced reactivity from the bimetallic structures. These results present a pathway to the bioinspired production of multimetallic materials with enhanced properties, which can be assessed via a suite of characterization methods to fully ascertain structure/function relationships.

  20. N, S co-doped-TiO2/fly ash beads composite material and visible light photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Lv, Jun; Sheng, Tong; Su, Lili; Xu, Guangqing; Wang, Dongmei; Zheng, Zhixiang; Wu, Yucheng

    2013-11-01

    Using TiCl4 as the titanium source, urea as the precipitating agent, nano-TiO2/fly ash beads composite materials were prepared by hydrolysis-precipitation method. Using (NH2)2CO and (NH2)2SC as the N and S source respectively, N and S co-doped TiO2/fly ash beads composite materials were prepared by grinding them together according to a certain proportion and calcined at 500 °C for 2 h. The composite materials were characterized by SEM, EDS, XPS, and UV-vis spectrophotometer methods. The UV-vis absorption spectra results show that the absorption edge of un-doped composites is 390 nm while that of doped composites red-shifts to 500 nm. The photocatalytic activity of composite materials was evaluated by degradation of methyl orange under visible light irradiation (halogen lamp, 250 W). The results showed that after irradiation for 1 h, degradation rate of N, S co-doped-TiO2/fly ash beads composite material can reach 65%, while the degradation rate of un-doped sample and P25 were just 10% and 6%, respectively. The composite material also showed excellent recycling properties.