Sample records for sanderson microform
-
Microform Market Place 1974/1975. An International Directory of Micropublishing.
Veaner, Allen B., Ed.; Meckler, Alan M., Ed.
The information for this international buyer's guide for the microform purchaser was gathered from questionnaires to the publishers themselves. The guide is divided into eight sections: directory of micropublishers, mergers and acquisitions, bibliography of first sources for the microform library, microform jobbers, organizations, a geographical…
-
Practical Microform Materials for Libraries: Silver, Diazo, Vesicular.
Veaner, Allen B.
1982-01-01
Remarks on the relative permanence and durability of three types of film in use in library microform reproduction (silver, diazo, and vesicular) and points out some technical and economic facts that govern the choice of microform materials for libraries. A 6-item reference list is included. (Author/JL)
-
Five Decades of Microforms at the Library of Congress.
Sullivan, Robert C.
1988-01-01
Discusses the history of the microform collections at the Library of Congress (LC), highlighting the exchange of microfilmed newspapers between LC and the Biblioteca Nacional, Brazil. Recent developments in preservation microfilming, LC's acquisition of microforms, and the activities of the LC Preservation Microfilming Office are described. (3…
-
Fu, Ming Wang
2014-01-01
‘Micro-scaled Products Development via Microforming’ presents state-of-the-art research on microforming processes, and focuses on the development of micro-scaled metallic parts via microforming processes. Microforming refers to the fabrication of microparts via micro-scaled plastic deformation and presents a promising micromanufacturing process. When compared to other micromanufacturing processes, microforming offers advantages such as high productivity and good mechanical properties of the deformed microparts. This book provides extensive and informative illustrations, tables and photos in order to convey this information clearly and directly to readers. Although the knowledge of macroforming processes is abundant and widely used in industry, microparts cannot be developed by leveraging existing knowledge of macroforming because the size effect presents a barrier to this knowledge transfer. Therefore systematic knowledge of microforming needs to be developed. In tandem with product miniaturization, t...
-
36 CFR 1238.26 - What are the restrictions on use for permanent and unscheduled microform records?
2010-07-01
... permanent and unscheduled microform records? (a) Agencies must not use the silver gelatin master microform or duplicate silver gelatin microform of permanent or unscheduled records created in accordance with...
-
Juottonen, Heli; Kotiaho, Mirkka; Robinson, Devin; Merilä, Päivi; Fritze, Hannu; Tuittila, Eeva-Stiina
2015-09-01
Vegetation and water table are important regulators of methane emission in peatlands. Microform variation encompasses these factors in small-scale topographic gradients of dry hummocks, intermediate lawns and wet hollows. We examined methane production and oxidization among microforms in four boreal bogs that showed more variation of vegetation within a bog with microform than between the bogs. Potential methane production was low and differed among bogs but not consistently with microform. Methane oxidation followed water table position with microform, showing higher rates closer to surface in lawns and hollows than in hummocks. Methanogen community, analysed by mcrA terminal restriction fragment length polymorphism and dominated by Methanoregulaceae or 'Methanoflorentaceae', varied strongly with bog. The extent of microform-related variation of methanogens depended on the bog. Methanotrophs identified as Methylocystis spp. in pmoA denaturing gradient gel electrophoresis similarly showed effect of bog, and microform patterns were stronger within individual bogs. Our results suggest that methane-cycling microbes in boreal Sphagnum bogs with seemingly uniform environmental conditions may show strong site-dependent variation. The bog-intrinsic factor may be related to carbon availability but contrary to expectations appears to be unrelated to current surface vegetation, calling attention to the origin of carbon substrates for microbes in bogs. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
-
Review on progressive microforming of bulk metal parts directly using sheet metals (Keynote Paper
Directory of Open Access Journals (Sweden)
Fu M.W.
2015-01-01
Full Text Available Due to the ubiquitous trend of product miniaturization, energy saving and weight reduction, micro/meso-scale parts have been widely used in many industrial clusters. Micromanufacturing processes for production of such micro/meso-scale parts are thus critically needed. Microforming, as one of these micro manufacturing processes, is a promising process and thus got many explorations and researches. Compared with the research on size effect affected deformation behaviours, less attention has been paid to the process development for mass production of micro-parts. The product quality and fabrication productivity of micro-parts depend on the involved process chain. To address the difficulty in handling and transporting of the micro-sized workpiece, development of a progressive microforming process for directly fabricating bulk micro-parts using sheet metals seems quite promising as it avoids or facilitates billet handling, transportation, positioning, and ejection in the process chain. In this paper, an intensive review on the latest development of progressive microforming technologies is presented. First of all, the paper summarizes the characteristic of progressive microforming directly using sheet metal. The size effect-affected deformation behaviour and the dimensional accuracy, deformation load, ductile fracture, and the surface finish of the microformed parts by progressive microforming using sheet metals are then presented. Finally, some research issues from the implementation of mass production perspective are also discussed.
-
2010-07-01
... specified in § 1232.14(c) of this subchapter. (c) Transfer the silver gelatin original (or duplicate silver gelatin microform created in accordance with § 1238.14) plus one microform copy. (d) Ensure that the... separately from the silver gelatin original or silver duplicate microform copy and clearly label them as non...
-
Unilateral microform cleft lip repair: application of muscle tension line group theory.
Yin, Ningbei; Song, Tao; Wu, Jiajun; Chen, Bo; Ma, Hengyuan; Zhao, Zhenmin; Wang, Yongqian; Li, Haidong; Wu, Di
2015-03-01
In microform cleft lip repair, reconstructing the elaborate structures is difficult. We describe a new technique of unilateral microform cleft lip repair that is based on the muscle tension line group theory. According to the shape of Cupid bow, a different small incision is used without creating an obvious cutaneous scar. First, the nasolabial muscle around the nasal floor (the first auxiliary tension line group) is reconstructed, and then the orbicularis oris muscle around the philtrum (the second auxiliary tension line group) is reconstructed based on the muscle tension line group theory. From June 2006 to June 2012, the technique was used in 263 unilateral microform cleft lip repairs. For 18 months, 212 patients were followed up. The appearance of the nasal alar, nasal sill, philtrum, and Cupid bow peak improved. Most patients had a satisfactory appearance. Based on the muscle tension line group theory, using this technique offers the ability to adduct the nasal alar effectively to form a good nasal sill and philtrum.
-
Directory of Open Access Journals (Sweden)
Shimizu Tetsuhide
2015-01-01
Full Text Available Application of diamond like carbon (DLC films are reported in several microforming processes, in view of its great tribological performance owe to the low friction and the high chemical stability. However, due to its high internal residual stress, the film properties with the low adhesion strength and the high wear rate under severe tribological conditions are still remain as technical issues. However, since the dynamic variation of the contact state cannot be observed during the forming operation, it is difficult to recognize the origin and the influential tribological factors of tool life for DLC coated microforming die. Therefore, the appropriate DLC film properties for the contact state in microforming operation have not been clarified. To observe the dynamic variation of the contact state during the microforming operation, present study developed a novel microforming die assembly installed the in-situ observation system with silica glass die and high speed recording camera. By using this system, the dynamic delamination behaviour of DLC films during the progressive micro-bending process was successfully demonstrated. The influential factors for the durability of DLC coated microdies were discussed.
-
Wildfire effects on vadose zone hydrology in forested boreal peatland microforms
Thompson, Dan K.; Waddington, James M.
2013-04-01
SummaryPeatland vulnerability to wildfire disturbance has been shown to vary as a function of hummock and hollow microforms and vadose zone hydrology, with low-lying hollow microforms most susceptible to deep combustion of peat. To better understand how this microform induced pattern of burning alters vadose water storage, pore-water pressure, and water table relationships, we examined a paired burned and unburned peatland in the boreal plain region of north central Alberta. Water table response to rain events increased significantly after wildfire, resulting in a more variable unsaturated zone thickness that was more responsive to smaller rain events. Water storage losses in the vadose zone occurred primarily at depths greater than 15 cm. Large peat surface water loss occurred in hummock microforms in the early spring due to the presence of unsaturated frozen peat at depth, likely a result of a vapour gradient from the unfrozen peat into the frozen peat underneath. During this period, the loss of water storage in the vadose zone satisfied up to 25% of daily evaporative demand, compared to only 3-5% during ice-free periods. A similar but less severe drying was observed late in summer, with burned hummocks the most vulnerable with high pore-water pressures. The enhanced surface drying observed is a precursor to high pore-water pressure conditions that inhibit Sphagnum regeneration. Our observations point to a paradox where the hummocks, being most resistant to combustion, are themselves most prone to high pore-water pressures following wildfire. The harsher hummock environment may contribute to the observed delay in post-fire Sphagnum regeneration in hummocks compared to hollows.
-
36 CFR 1238.20 - How must microform records be stored?
2010-07-01
... relative humidity of the storage area must be a constant 35 percent RH, plus or minus 5 percent. Non-silver copies of microforms must be maintained in a different storage area than are silver gelatin originals or...
-
Tool Wear and Life Span Variations in Cold Forming Operations and Their Implications in Microforming
Directory of Open Access Journals (Sweden)
Anders E. W. Jarfors
2016-12-01
Full Text Available The current paper aims to review tooling life span, failure modes and models in cold microforming processes. As there is nearly no information available on tool-life for microforming the starting point was conventional cold forming. In cold forming common failures are (1 over stressing of the tool; (2 abrasive wear; (3 galling or adhesive wear, and (4 fatigue failure. The large variation in tool life observed in production and how to predict this was reviewed as this is important to the viability of microforming based on that the tooling cost takes a higher portion of the part cost. Anisotropic properties of the tool materials affect tool life span and depend on both the as-received and in-service conditions. It was concluded that preconditioning of the tool surface, and coating are important to control wear and fatigue. Properly managed, the detrimental effects from surface particles can be reduced. Under high stress low-cycle fatigue conditions, fatigue failure form internal microstructures and inclusions are common. To improve abrasive wear resistance larger carbides are commonly the solution which will have a negative impact on tooling life as these tend to be the root cause of fatigue failures. This has significant impact on cold microforming.
-
Research Sources and Microforms in Black Studies: An Annotated Bibliography.
Ridinger, Robert B. Marks
1985-01-01
Analyzes 93 reference works and 23 microform collections concerning the Black American experience in 13 subject areas of the social sciences (anthropology, biography, race relations and civil rights, the Black church, communication studies, economics, education, dance, genealogy, Black history, sports, women's studies, and literature and language)…
-
Development of microforming process combined with thin film transfer printing
Directory of Open Access Journals (Sweden)
Koshimizu Kazushi
2015-01-01
Full Text Available Microforming receives a lot of attentions in the recent years due to the increased use of microparts in electronics and medical sectors. For the further functionalization of these micro devices, high functional surface with noble metals are strongly required for the devices in bio- and medical fields, such as bio-sensors. To realize the submillimeter structure of metal foils and micro to nanometer structures in one forming process, the present study proposes a combined process of microforming for metal foils and transfer printing of gold (Au thin films. To clarify the availability of the proposed combined process, transferability of Au thin films under micro bulging deformation are investigated. 0.1 mm-thick pure titanium (Ti foils and 100 nm-thick Au films were used as blank and functional materials, respectively. The forming tests of the proposed process were conducted. With increasing strain of Ti foils, Au TP areas increase. By this experiment, it’s confirmed that the hydrogen reduction of oxidation layers and the strain of Ti foil are significant factor for Au TP on Ti foils.
-
Fabrication of Times and Micro-Formation of Discourse at a Secondary School
Directory of Open Access Journals (Sweden)
Michalis Kontopodis
2007-01-01
Full Text Available The paper presented here starts with a reference to modernist time theories, followed by a presentation of alternative views in the works of FOUCAULT, DELEUZE, LATOUR and others. The study concentrates on the concrete context of an experimental school aiming at incorporation of excluded students into society. Based on the synthesis of discourse analysis and Actor-Network-Theory, the study puts forward a twofold question: a whether and how the "fabrication of times" is interrelated to micro-formations of discourses and b how micro-formations of discourses emerge as processes in the concrete setting of a school in regard to their temporal and other aspects. To answer this query, I combine some critical ethnographic work with an Actor-Network-Theory methodology—an approach which could be regarded as "rhizomatic analysis" (DELEUZE & GUATTARI, 1980. Examining discursive and non-discursive action with a particular focus on materialities (sites, students' documents, educational reports, CVs, and files, I introduce the notion of "temporal devices of control" and map two of them: that of synchronicity and that of convergence. In this way, I propose a new understanding of time and relate it to discourse formation. This, in turn, reveals a new potential for critical reflection on theories of time as well as on all action taking place in the school. URN: urn:nbn:de:0114-fqs0701119
-
2010-07-01
... 1232 of this chapter and the additional requirements in this section. (b) Package non-silver copies separately from the silver gelatin original or silver duplicate microform copy and clearly label them as non-silver copies. (c) Include the following information on the transmittal (SF 135 for NARA Federal Records...
-
Measurement of material mechanical properties in microforming
Yun, Wang; Xu, Zhenying; Hui, Huang; Zhou, Jianzhong
2006-02-01
As the rapid market need of micro-electro-mechanical systems engineering gives it the wide development and application ranging from mobile phones to medical apparatus, the need of metal micro-parts is increasing gradually. Microforming technology challenges the plastic processing technology. The findings have shown that if the grain size of the specimen remains constant, the flow stress changes with the increasing miniaturization, and also the necking elongation and the uniform elongation etc. It is impossible to get the specimen material properties in conventional tensile test machine, especially in the high precision demand. Therefore, one new measurement method for getting the specimen material-mechanical property with high precision is initiated. With this method, coupled with the high speed of Charge Coupled Device (CCD) camera and high precision of Coordinate Measuring Machine (CMM), the elongation and tensile strain in the gauge length are obtained. The elongation, yield stress and other mechanical properties can be calculated from the relationship between the images and CCD camera movement. This measuring method can be extended into other experiments, such as the alignment of the tool and specimen, micro-drawing process.
-
36 CFR 1238.5 - What publications are incorporated by reference in this part?
2010-07-01
... Stored Silver-Gelatin Microforms for Evidence of Deterioration, January 22, 1990, IBR approved for § 1238... Materials—Processed silver-gelatin type black-and-white films—Specifications for stability, February 15... Assurance of First-Generation, Silver Microforms of Documents, June 2, 1998, IBR approved for §§ 1238.10 and...
-
Energy Technology Data Exchange (ETDEWEB)
Dorodnikov, M.; Wilmking, M. [Greifswald Univ. (Georgia). Inst. of Botany and Landscape Ecology; Marushchak, M.; Biasi, C. [Univ. of Eastern Finland, Kuopio (Finland). Dept. of Environmental Science, Bioteknia 2], E-mail: maxim.dorodnikov@uef.fi
2013-09-01
The application of stable isotopes is an approach to identify pathways of methanogenesis, methane (CH{sub 4}) oxidation and transport in peatlands. We measured the stable C isotopic characteristics ({delta}C-13) of CH{sub 4} in peat profiles below hummocks, lawns and hollows of a Finnish mire to study the patterns of CH{sub 4} turnover. Porewater CH{sub 4} concentrations ([CH{sub 4}]; at 0.5-2 m) increased with depth below all microforms. Emissions of CH{sub 4} from hummocks were the lowest, and increased with the increasing water-saturated zone, being {approx}10 times higher from hollows. Thus, the microtopography of the peatland did not affect the porewater [CH{sub 4}] in the water-saturated part of the peat profile, but the CH{sub 4} emissions were affected due to differences in the oxidative potential of the microforms. There was a decrease in {delta}C-13-CH{sub 4} with depth below all microforms indicating dominance of CO{sub 2}-reduction over acetate cleavage pathway of methanogenesis at deep peat layers. However, estimated potential portions of transported CH{sub 4} comprised 50%-70% of the {delta}C-13-CH{sub 4} enrichment on microforms at the 0.5-m depth, hereby masking the acetate cleavage pathway of methanogenesis. Stable C composition ({delta}C-13) of CH{sub 4} proved to be a suitable (but not sufficient) tool to differentiate between types of methanogenesis in continuously water-saturated layers below microforms of a peatland. Combined flux-based and multi-isotopic approaches are needed to better understand the CH{sub 4} turnover process. (orig.)
-
Book Review | Robertson | African Review of Economics and Finance
African Journals Online (AJOL)
Abstract. China's Superbank: Debt, Oil and Influence - How China Development Bank is Rewriting the Rules of Finance Henry Sanderson and Michael Forsythe. John Wiley & Sons, Singapore, 2013, 181 pp. ISBN: 978-1-118-17636-8 ...
-
Bronsted acid-functionalized choline chloride-butane sultone for the ...
Indian Academy of Sciences (India)
M P PADMA PRIYA
2018-03-21
Mar 21, 2018 ... Choline chloride and 1,4-butane sultone were combined to obtain a sulphonic acid-functionalized ..... Knifton J F and Sanderson J R 1990 Method for produc- ... alkenes via the Knoevenagel condensation Tetrahedron. Lett.
-
Cognitive Work Analysis: Foundations, Extensions, and Challenges
2011-11-01
preserves the information and relationships in the abstraction-decomposition space. This will serve as an externalised mental representation of work domain...C., & Sanderson, P. M. (2002b). Work domain analysis and sensors II: Pasteurizer II case study. International Journal of Human-Computer Studies, 56(6
-
1987-12-01
discipline comparable to physics or chemistry in its application. This concept is quite unusual for an American, as military affairs are not often studied in...Sanderson cites definitions from The Pocket Oxford Dictionary, The 67 Oxford Dictionary of English Etymology , and Blackie ’s Compact Etymological
-
2011-05-01
Gene G. Sanderson George E. Cox Gerald A. Rush* Gerald Goodson Ginny Graybiel Glenda L. Glover Gordon Eldridge Gordon Goodin Greg Artabasy Greg... Fanc ~np. Thank you very much. COLONEL CUMBIE: Thank you, sir. !Vlr. Robert Larson . MR. LARSON: My name is Robert Larson . The Military Housing
-
Dan, Aviva
2016-01-01
Deficits in self-regulatory skills underlie or contribute to a range of adverse developmental problems and disorders, including ADHD (Barkley, 1997), eating disorders (Attie & Brooks-Gunn, 1995) and risk -taking behaviour (Cantor & Sanderson 1998; Eisenberg et al., 2005). Self-regulation has been recognised as an important factor in aiding…
-
Van Winkle, Katie
2012-01-01
The author first learned about cultural diversity and racial justice in Mr. Sanderson's middle school English class. They read a book called "The House on Mango Street" by Sandra Cisneros and learned about a different culture, but also about a community with striking similarities to their own. The main character in the novel, Esperanza,…
-
25 CFR 36.40 - Standard XIII-Library/media program.
2010-04-01
... philosophy. The librarian or educational media specialist, with students and staff, shall set objectives... the following: Tactile objects, globes, models, maps, films, film-strips, microforms, slides, audio...
-
Prediction of Solar-Terrestrial Disturbances: Decay Phase of Energetic Proton Events.
1982-10-01
Dependence of 50 keV upstream ion events at IMP 7/8 upon magnetic field-bow shock geometry in the earth’s foreshock : A statistical study, J. Geophys_.Rers...ion events in the F. C. Roelof Earth’s foreshock R. Reinhard ISEE-3/IKtP-8 observations of simultaneous upstream proton T. R. Sanderson events K.-P
-
Journal of Mormon History Vol. 33, No. 2, 2007
2007-01-01
CONTENTS ARTICLES --The Reed Smoot Hearings: A Quest for Legitimacy Harvard S. Heath, 1 --Senator George Sutherland: Reed Smoot’s Defender Michael Harold Paulos, 81 --Daniel S. Tuttle: Utah’s Pioneer Episcopal Bishop Frederick Quinn, 119 --Civilizing the Ragged Edge: Jacob Hamblin’s Wives Todd Compton, 155 --Dr. George B. Sanderson: Nemesis of the Mormon Battalion Sherman L. Fleek, 199 REVIEWS --Pet...
-
48 CFR 1852.208-81 - Restrictions on Printing and Duplicating.
2010-10-01
..., presswork, duplicating, silk screen processes, binding, microform, and the end items of such processes and... one sheet, size 8-1/2×11 inches (215×280 mm), one side only, and one color ink. (d) This clause does...
-
THE IMPACT OF TECHNOLOGY ON THE LIBRARY BUILDING.
Educational Facilities Labs., Inc., New York, NY.
LIBRARY PLANNERS SHOULD EXPECT AUTOMATION, MICROFORMS, AND FACSIMILE TRANSMISSION TO MODIFY BUT NOT RADICALLY CHANGE THE LIBRARY AS THE INSTITUTION WE NOW KNOW IT TO BE. CHANGES WILL INVOLVE TRADE-OFFS IN SPACE AND DEMANDS FOR ADDITIONAL SPACE. (MF)
-
Optical Digital Disk Storage: An Application for News Libraries.
Crowley, Mary Jo
1988-01-01
Describes the technology, equipment, and procedures necessary for converting a historical newspaper clipping collection to optical disk storage. Alternative storage systems--microforms, laser scanners, optical storage--are also retrieved, and the advantages and disadvantages of optical storage are considered. (MES)
-
Medical Surveillance Monthly Report. Volume 20, Number 10
2013-10-01
5. Sanderson WC, DiNardo PA, Rapee RM, Barlow DH. Syndrome comorbidity in patients diagnosed with DSM-III-R anxiety disorder. J Abnorm Psychol...anxiety becomes chronic and exaggerated, and aff ects the physi- cal and psychological health of the individual. Th e main types of anxiety dis- orders are...aff ect both physical and psychological health. Individuals with anxiety disorders commonly suff er from other mental disorders such as mood disor
-
Finding of No Significant Impact and Environmental Assessment for Flight Test to the Edge of Space
2008-12-01
Runway 22 or on Rogers Dry Lakebed at Edwards AFB. 17 On the basis of the findings of the Environmental Assessment, no significant impact to human...FLIGHT TEST CENTER Environmental Assessment for Flight Test to the Edge of Space Page 5-3 Bowles, A.E., S. Eckert, L . Starke, E. Berg, L . Wolski, and...Numbers. Anne Choate, Laura 20 Pederson , Jeremy Scharfenberg, Henry Farland. Washington, D.C. September. 21 Jeppesen Sanderson, Incorporated 22
-
The value of children in the context of the family in Java / by Paul A. Meyer
Meyer, Paul A
1987-01-01
... The value of children in the context of the family in Java [microform] / by Paul A. Meyer. The value of children in the context of the family in Java by Paul A. Meyer. The value of children in the context of the family in Java ...
-
In-plane laser forming for high precision alignment
Folkersma, Ger; Römer, Gerardus Richardus, Bernardus, Engelina; Brouwer, Dannis Michel; Huis in 't Veld, Bert
2014-01-01
Laser microforming is extensively used to align components with submicrometer accuracy, often after assembly. While laser-bending sheet metal is the most common laser-forming mechanism, the in-plane upsetting mechanism is preferred when a high actuator stiffness is required. A three-bridge planar
-
2015-06-18
techniques, microforming can produce micro devices with features up to the millimeter range which can be used to mold precise plastic parts or as a...adjacent device deposited debris across every other device. Figure 55 clearly shows the debris field produced by the disintegration of the
-
Ellison, Ashton C; Campbell, A John; Robertson, M Clare; Sanderson, Gordon F
2014-01-01
Ashton C Ellison, A John Campbell, M Clare Robertson, Gordon F SandersonDunedin School of Medicine, Department of Medicine, Dunedin, New ZealandBackground: Multifocal glasses (bifocals, trifocals, and progressives) increase the risk of falling in elderly people, but how they do so is unclear. To explain why glasses with progressive addition lenses increase the risk of falls and whether this can be attributed to false projection, this study aimed to 1) map the prismatic displacement of a progr...
-
Micro-hydromechanical deep drawing of metal cups with hydraulic pressure effects
Luo, Liang; Jiang, Zhengyi; Wei, Dongbin; Wang, Xiaogang; Zhou, Cunlong; Huang, Qingxue
2018-03-01
Micro-metal products have recently enjoyed high demand. In addition, metal microforming has drawn increasing attention due to its net-forming capability, batch manufacturing potential, high product quality, and relatively low equipment cost. Micro-hydromechanical deep drawing (MHDD), a typical microforming method, has been developed to take advantage of hydraulic force. With reduced dimensions, the hydraulic pressure development changes; accordingly, the lubrication condition changes from the macroscale to the microscale. A Voronoi-based finite element model is proposed in this paper to consider the change in lubrication in MHDD according to open and closed lubricant pocket theory. Simulation results agree with experimental results concerning drawing force. Changes in friction significantly affect the drawing process and the drawn cups. Moreover, defined wrinkle indexes have been shown to have a complex relationship with hydraulic pressure. High hydraulic pressure can increase the maximum drawing ratio (drawn cup height), whereas the surface finish represented by the wear is not linearly dependent on the hydraulic pressure due to the wrinkles.
-
Council On Library Resources, Inc. Seventeenth Annual Report, For the Year Ending June 30, 1973.
Council on Library Resources, Inc., Washington, DC.
This report describes the efforts of the Council on Library Resources to enhance the effectiveness, efficiency, and economy of operations in libraries during 1972-73. It covers 9 major areas: national library services, automation and networks, the academic library, the public library, microform and nonprint media, preservation and library…
-
NONINI, CERISE
A SURVEY BY QUESTIONNAIRE WAS MADE OF THE PROBLEM OF USER SERVICES AND EXTENSION SERVICES USED IN THE DISSEMINATION OF MATERIALS AND INFORMATION TO A SELECTED NUMBER OF INDUSTRIAL LIBRARIES. THE SURVEY RESULTED IN DATA CONCERNING STAFF SIZE, PROFESSIONAL-TO-CLERICAL RATIO, SIZE OF BOOK, DOCUMENT, PERIODICAL AND MICROFORM COLLECTIONS, LIBRARY…
-
National Libraries Section. General Research Libraries Division. Papers.
International Federation of Library Associations, The Hague (Netherlands).
Papers on national library services and activities, which were presented at the 1983 International Federation of Library Associations (IFLA) conference, include: (1) "The National Library of China in its Gradual Application of Modern Technology," a discussion by Zhu Nan and Zhu Yan (China) of microform usage and library automation; (2)…
-
34 CFR 668.24 - Record retention and examinations.
2010-07-01
... representative. (3) An institution may keep required records in hard copy or in microform, computer file, optical disk, CD-ROM, or other media formats, provided that— (i) Except for the records described in paragraph (d)(3)(ii) of this section, all record information must be retrievable in a coherent hard copy format...
-
Harvard Univ., Cambridge, MA. Graduate School of Education.
The purpose of the conference was to investigate the implications of new technologies for library architecture and to use the findings in planning new Library Research Facility for the Harvard Graduate School of Education. The first half of this document consists of reports prepared by six consultants on such topics as microforms, computers,…
-
Committee of DDC Users in the Greater Washington, DC. Area, Washington, DC.
A change in policy of the Defense Documentation Center (DDC) with regard to supplying hard copy and/or microforms of reports caused problems to users of the DDC Technical Report Service. Discussions among users of the service, a questionnaire survey and committee reports summarized basic user concerns, provided selected statistics and a look at…
-
Effect of laser energy on the deformation behavior in microscale laser bulge forming
International Nuclear Information System (INIS)
Zheng Chao; Sun Sheng; Ji Zhong; Wang Wei
2010-01-01
Microscale laser bulge forming is a high strain rate microforming method using high-amplitude shock wave pressure induced by pulsed laser irradiation. The process can serve as a rapidly established and high precision technique to impress microfeatures on thin sheet metals and holds promise of manufacturing complex miniaturized devices. The present paper investigated the forming process using both numerical and experimental methods. The effect of laser energy on microformability of pure copper was discussed in detail. A 3D measuring laser microscope was adopted to measure deformed regions under different laser energy levels. The deformation measurements showed that the experimental and numerical results were in good agreement. With the verified simulation model, the residual stress distribution at different laser energy was predicted and analyzed. The springback was found as a key factor to determine the distribution and magnitude of the compressive residual stress. In addition, the absorbent coating and the surface morphology of the formed samples were observed through the scanning electron microscope. The observation confirmed that the shock forming process was non-thermal attributed to the protection of the absorbent coating.
-
Recent Developments in Microhydroforming
Directory of Open Access Journals (Sweden)
F. Forouhandeh
2013-01-01
Full Text Available Microforming is an emerging forming technology area in which small parts of 1 mm or less are formed under a variety of processes and process conditions. The technology is serving several industries like machine tools, medical and surgery, aerospace, atomic power, automotive, and energy sectors. Hydroforming has been a major field of interest for engineering and scientific research as well as designers and developers to look for its optimal process in terms of surface quality and part consolidation. Sheet hydroforming (SHF process is found to be a special one for sheet metal component manufacturing formed under high fluid pressure. In this paper, an overview of various aspects of research on microforming and microhydroforming (sheet/tube hydroforming by the authors and others in general has been presented. Most of the papers reviewed herein relate to modeling and simulation of the process and various forming issues such as process parameters, and experimental study of different alloys has been studied. Finally, current ongoing research on micro-SHF work by the authors has been introduced.
-
Tribological influence of tool surface roughness within microforming
DEFF Research Database (Denmark)
Eriksen, Rasmus Solmer; Weidel, S.; Hansen, Hans Nørgaard
2010-01-01
A comparative friction study of tooling dies with a simple internal cylindrical geometry has been performed. The purpose of the experiment consist of studying the influence of the surface characteristics of tooling dies on the frictional behaviour in a micro bulk forming operation. This research ...
-
Directory of Open Access Journals (Sweden)
Fei Li
2015-11-01
Full Text Available Quantitative structure-activity relationships (QSARs were determined using partial least square (PLS and support vector machine (SVM. The predicted values by the final QSAR models were in good agreement with the corresponding experimental values. Chemical estrogenic activities are related to atomic properties (atomic Sanderson electronegativities, van der Waals volumes and polarizabilities. Comparison of the results obtained from two models, the SVM method exhibited better overall performances. Besides, three PLS models were constructed for some specific families based on their chemical structures. These predictive models should be useful to rapidly identify potential estrogenic endocrine disrupting chemicals.
-
DB2 9 for Linux, Unix, and Windows database administration certification study guide
Sanders, Roger E
2007-01-01
In DB2 9 for Linux, UNIX, and Windows Database Administration Certification Study Guide, Roger E. Sanders-one of the world's leading DB2 authors and an active participant in the development of IBM's DB2 certification exams-covers everything a reader needs to know to pass the DB2 9 UDB DBA Certification Test (731).This comprehensive study guide steps you through all of the topics that are covered on the test, including server management, data placement, database access, analyzing DB2 activity, DB2 utilities, high availability, security, and much more. Each chapter contains an extensive set of p
-
Sanderson, Dan
2010-01-01
As one of today's cloud computing services, Google App Engine does more than provide access to a large system of servers. It also offers you a simple model for building applications that scale automatically to accommodate millions of users. With Programming Google App Engine, you'll get expert practical guidance that will help you make the best use of this powerful platform. Google engineer Dan Sanderson shows you how to design your applications for scalability, including ways to perform common development tasks using App Engine's APIs and scalable services. You'll learn about App Engine's a
-
Recent Developments in Microhydroforming
F. Forouhandeh; S. Kumar; S. N. Ojha; R. Balasubramanian
2013-01-01
Microforming is an emerging forming technology area in which small parts of 1 mm or less are formed under a variety of processes and process conditions. The technology is serving several industries like machine tools, medical and surgery, aerospace, atomic power, automotive, and energy sectors. Hydroforming has been a major field of interest for engineering and scientific research as well as designers and developers to look for its optimal process in terms of surface quality and part consolid...
-
Microrelief Associated with Gas Emission Craters: Remote-Sensing and Field-Based Study
Directory of Open Access Journals (Sweden)
Alexander Kizyakov
2018-04-01
Full Text Available Formation of gas emission craters (GEC is a new process in the permafrost zone, leading to considerable terrain changes. Yet their role in changing the relief is local, incomparable in the volume of the removed deposits to other destructive cryogenic processes. However, the relief-forming role of GECs is not limited to the appearance of the crater itself, but also results in positive and negative microforms as well. Negative microforms are rounded hollows, surrounded by piles of ejected or extruded deposits. Hypotheses related to the origin of these forms are put forward and supported by an analysis of multi-temporal satellite images, field observations and photographs of GECs. Remote sensing data specifically was used for interpretation of landform origin, measuring distances and density of material scattering, identifying scattered material through analysis of repeated imagery. Remote-sensing and field data reliably substantiate an impact nature of the hollows around GECs. It is found that scattering of frozen blocks at a distance of up to 293 m from a GEC is capable of creating an impact hollow. These data indicate the influence of GEC on the relief through the formation of a microrelief within a radius of 15–20 times the radius of the crater itself. Our study aims at the prediction of risk zones.
-
A Guide to the Microform Collections of the USMA Library.
1980-01-01
the Renaissance and the Elizabethian period. One may find the earliest editions of Chaucer, Spenser, Shakespeare , More, Erasumus, and Bacon. Military...laws. As a companion to its indexing and abstracting services, CIS provides a comprehensive collection of contemporary government documents on
-
International Nuclear Information System (INIS)
Phan Thanh An
2008-06-01
The convex rope problem, posed by Peshkin and Sanderson in IEEE J. Robotics Automat, 2 (1986) pp. 53-58, is to find the counterclockwise and clockwise convex ropes starting at the vertex a and ending at the vertex b of a simple polygon, where a is on the boundary of the convex hull of the polygon and b is visible from infinity. In this paper, we present a linear time algorithm for solving this problem without resorting to a linear-time triangulation algorithm and without resorting to a convex hull algorithm for the polygon. The counterclockwise (clockwise, respectively) convex rope consists of two polylines obtained in a basic incremental strategy described in convex hull algorithms for the polylines forming the polygon from a to b. (author)
-
BOOK REVIEW: Fundamentals of Plasma Physics
Cargill, P. J.
2007-02-01
The widespread importance of plasmas in many areas of contemporary physics makes good textbooks in the field that are both introductory and comprehensive invaluable. This new book by Paul Bellen from CalTech by and large meets these goals. It covers the traditional textbook topics such as particle orbits, the derivation of the MHD equations from Vlasov theory, cold and warm plasma waves, Landau damping, as well as in the later chapters less common subjects such as magnetic helicity, nonlinear processes and dusty plasmas. The book is clearly written, neatly presented, and each chapter has a number of exercises or problems at their end. The author has also thankfully steered clear of the pitfall of filling the book with his own research results. The preface notes that the book is designed to provide an introduction to plasma physics for final year undergraduate and post-graduate students. However, it is difficult to see many physics undergraduates now at UK universities getting to grips with much of the content since their mathematics is not of a high enough standard. Students in Applied Mathematics departments would certainly fare better. An additional problem for the beginner is that some of the chapters do not lead the reader gently into a subject, but begin with quite advanced concepts. Being a multi-disciplinary subject, beginners tend to find plasma physics quite hard enough even when done simply. For postgraduate students these criticisms fade away and this book provides an excellent introduction. More senior researchers should also enjoy the book, especially Chapters 11-17 where more advanced topics are discussed. I found myself continually comparing the book with my favourite text for many years, `The Physics of Plasmas' by T J M Boyd and J J Sanderson, reissued by Cambridge University Press in 2003. Researchers would want both books on their shelves, both for the different ways basic plasma physics is covered, and the diversity of more advanced topics. For
-
Fundamentals of Plasma Physics
International Nuclear Information System (INIS)
Cargill, P J
2007-01-01
The widespread importance of plasmas in many areas of contemporary physics makes good textbooks in the field that are both introductory and comprehensive invaluable. This new book by Paul Bellen from CalTech by and large meets these goals. It covers the traditional textbook topics such as particle orbits, the derivation of the MHD equations from Vlasov theory, cold and warm plasma waves, Landau damping, as well as in the later chapters less common subjects such as magnetic helicity, nonlinear processes and dusty plasmas. The book is clearly written, neatly presented, and each chapter has a number of exercises or problems at their end. The author has also thankfully steered clear of the pitfall of filling the book with his own research results. The preface notes that the book is designed to provide an introduction to plasma physics for final year undergraduate and post-graduate students. However, it is difficult to see many physics undergraduates now at UK universities getting to grips with much of the content since their mathematics is not of a high enough standard. Students in Applied Mathematics departments would certainly fare better. An additional problem for the beginner is that some of the chapters do not lead the reader gently into a subject, but begin with quite advanced concepts. Being a multi-disciplinary subject, beginners tend to find plasma physics quite hard enough even when done simply. For postgraduate students these criticisms fade away and this book provides an excellent introduction. More senior researchers should also enjoy the book, especially Chapters 11-17 where more advanced topics are discussed. I found myself continually comparing the book with my favourite text for many years, 'The Physics of Plasmas' by T J M Boyd and J J Sanderson, reissued by Cambridge University Press in 2003. Researchers would want both books on their shelves, both for the different ways basic plasma physics is covered, and the diversity of more advanced topics. For
-
Boc modifies the spectrum of holoprosencephaly in the absence of Gas1 function
Directory of Open Access Journals (Sweden)
Maisa Seppala
2014-07-01
Full Text Available Holoprosencephaly is a heterogeneous developmental malformation of the central nervous system characterized by impaired forebrain cleavage, midline facial anomalies and wide phenotypic variation. Indeed, microforms represent the mildest manifestation, associated with facial anomalies but an intact central nervous system. In many cases, perturbations in sonic hedgehog signaling are responsible for holoprosencephaly. Here, we have elucidated the contribution of Gas1 and an additional hedgehog co-receptor, Boc during early development of the craniofacial midline, by generating single and compound mutant mice. Significantly, we find Boc has an essential role in the etiology of a unique form of lobar holoprosencephaly that only occurs in conjunction with combined loss of Gas1. Whilst Gas1−/− mice have microform holoprosencephaly characterized by a single median maxillary central incisor, cleft palate and pituitary anomalies, Boc−/− mice have a normal facial midline. However, Gas1−/−; Boc−/− mutants have lobar holoprosencephaly associated with clefting of the lip, palate and tongue, secondary to reduced sonic hedgehog transduction in the central nervous system and face. Moreover, maxillary incisor development is severely disrupted in these mice, arresting prior to cellular differentiation as a result of apoptosis in the odontogenic epithelium. Thus, Boc and Gas1 retain an essential function in these tooth germs, independent of their role in midline development of the central nervous system and face. Collectively, this phenotype demonstrates both redundancy and individual requirements for Gas1 and Boc during sonic hedgehog transduction in the craniofacial midline and suggests BOC as a potential digenic locus for lobar holoprosencephaly in human populations.
-
Dynamic effect in ultrasonic assisted micro-upsetting
Presz, Wojciech
2018-05-01
The use of ultrasonic assistance in microforming is becoming more and more popular. Mainly due to the beneficial effect of vibrations on the flow of plastic deformation reported already in the 50s of the last century. The influence is of two types: surface and volume. The surface effect is mainly the reduction of friction forces, and volumetric is the impact on the dislocation movement and even on phase transitions. The work focuses on the dynamic aspect of vibration assisted microforming. The use of ultrasonic vibrations at a frequency of 20 kHz and an amplitude of 16 µm, in the micro-upsetting process of an aluminum sample resulted in a high concentration of strain on both ends of the sample - at 14% of the height on both sides. There was observed (in relation to deformations of the sample without vibrations) 150-250% increase and a 50% decrease in strain in the center of the sample. At the same time, the larger deformations occurred from the impact side of the punch. Analyzing the course of forces of the upsetting process in the loading and unloading phase as well as the process of breaking glass samples, the spring deflections of key system elements and their natural frequencies were determined or calculated. Based on the determined or calculated parameters of the test stand, it was shown that during the micro-upsetting process the punch may detach from the sample surface and this is the main reason for the phenomena occurring. Detach of the punch is also the cause of the observed instability of the measurement of force, which should be considered unbelievable in such a situation.
-
Cryophenomena in the Cold Desert of Atacama
Buchroithner, Dr.; Trombotto, Dr.
2012-04-01
The study area of the Valle de Barrancas Blancas in the High Atacama Andes of Chile (68°39' W, 27°02' S), a kind of Patagonian "bajo sin salida", shows well preserved landforms resulting from a combination of slope, eolian, lacustrine/litoral, fluvial, glacial and periglacial regimes. They permit the reconstruction of geomorphological processes within this isolated catchment of approximately 160 km2. The mean annual air temperature varies between -2 and -4 °C and the precipitation is approximately 150 mm/a. Snowfall is frequent but the snow is quickly sublimated, redeposited and/or covered by cryosediments, i.e. mainly pumice pebbles. Water bodies present icings, even in summer. Regarding its climatic conditions the study area represents an extremely cold desertic region. Extremophile microfauna was also found. The area displays both in situ mountain permafrost and creeping permafrost. The active layer is 30 to 45 cm thick. It is a periglacial macro-environment where interdependent processes, and not only cryogenic processes but also erosion and eolian deposition and the action of fluvial washout mainly caused by precipitation, accumulation, retransportation/redeposition and melting of snow, play an important role. The cryogenic geomorphology of the Valle de Barrancas Blancas is varied and contains microforms such as patterned ground and microforms caused by cryoturbation, as well as mesoforms like rockglaciers and cryoplanation surfaces. Slopes are strongly affected by gelifluction. New cryoforms in South America and in the Southern Hemisphere like the Atacama Pingo (Pingo atacamensis) and Permafrosted Dunes ("Dunas heladas") were found. Intense niveo-eolian processes participate in the erosion of preexisting landforms, in the formation of subterraneous ice layers, and the retransportation/redeposition of snow and sediments. Studies of this periglacial environment are crucial for the understanding of Tundrean paleoenvironments and Martian conditions.
-
Datta, Dipankar; Shee, Nirmal K; von Szentpály, László
2013-01-10
We present the first large-scale empirical examination of the relation of molecular chemical potentials, μ(0)(mol) = -½(I(0) + A(0))(mol), to the geometric mean (GM) of atomic electronegativities, (GM) = (GM), and demonstrate that μ(0)(mol) ≠ -(GM). Out of 210 molecular μ(0)(mol)values considered more than 150 are not even in the range min{μ(0)(at)} (GM). For this equation the root-mean-square of relative errors amounts to SE = 71%. Our results are at strong variance with Sanderson's electronegativity equalization principle and present a challenge to some popular practice in conceptual density functional theory (DFT). The influences of the "external" potential and charge dependent covalent and ionic binding contributions are discussed and provide the theoretical rationalization for the empirical facts. Support is given to the warnings by Hinze, Bader et al., Allen, and Politzer et al. that equating the chemical potential to the negative of electronegativity may lead to misconceptions.
-
Idiosyncratic musings on studying cases
Directory of Open Access Journals (Sweden)
Christophe Bredillet
2016-11-01
Full Text Available For the past 60 years, organisations have increasingly been using projects and management of, by and for projects to achieve their strategic objectives (Morris & Jamieson, 2004; Morris & Geraldi, 2011. Project management (PM makes an important and significant contribution to value creation globally. However, the ‘glocal’ context in which projects are performed shows increasing volatility, uncertainty, complexity, and ambiguity (‘VUCA’ affecting organisations and the socio-economic environment, within which they operate (Gareis, 2005. Two main dimensions are considered in research: uncertainty (and its two dimensions: volatility and ambiguity, and complexity (Bredillet, 2015. Because action takes place over time, and because the future is unknowable, action is inherently uncertain (Aristotle, 1926, 1357a. Acts involve time, irreversibility, indetermination and contingence, and uncertainty (Sanderson, 2012; Knight, 1921. "We simply do not know" (Keynes, 1937, pp. 113–114. Management situations (here both Practice and Research are complex systems in the way they involve interdependence and connections between actors, ‘objects’ and the context.
-
Lead poisoning in a Mississippi sandhill crane
Franson, J. Christian; Hereford, Scott G.
1994-01-01
Lead poisoning from the ingestion of spent lead shot is well documented in waterfowl (Sanderson and Bellrose 1986) and has been reported in other wetland (Locke et al. 1991, Windingstad et al. 1984) and upland (Hunter and Rosen 1965, Locke and Bagley 1967) avian species. Ingested fishing weights have been implicated in lead poisoning of Trumpeter Swans (Cygnus buccinator) (Blus et al. 1989), Common Loons (Gavia immer) (Locke et al. 1982, Franson and Cliplef 1992, Pokras and Chafe1 1992), Mute Swans (Cygnus olor) (Birkhead 1982), and Sandhill Cranes (Grus canadensis) (Windingstad et al. 1984). The significance of lead poisoning as a mortality factor in avian species other than waterfowl is probably underestimated (Locke and Friend 1992), and any cause of mortality becomes particularly important in species with small population sizes. We report here the first known case of lead poisoning in a Mississippi Sandhill Crane (Grus canadensis pulla), a critically endangered subspecies.
-
International Nuclear Information System (INIS)
Konoz, Elahe; Golmohammadi, Hassan
2008-01-01
An artificial neural network (ANN) was constructed and trained for the prediction of air-to-blood partition coefficients of volatile organic compounds. The inputs of this neural network are theoretically derived descriptors that were chosen by genetic algorithm (GA) and multiple linear regression (MLR) features selection techniques. These descriptors are: R maximal autocorrelation of lag 1 weighted by atomic Sanderson electronegativities (R1E+), electron density on the most negative atom in molecule (EDNA), maximum partial charge for C atom (MXPCC), surface weighted charge partial surface area (WNSA1), fractional charge partial surface area (FNSA2) and atomic charge weighted partial positive surface area (PPSA3). The standard errors of training, test and validation sets for the ANN model are 0.095, 0.148 and 0.120, respectively. Result obtained showed that nonlinear model can simulate the relationship between structural descriptors and the partition coefficients of the molecules in data set accurately
-
Delineation of gravel-bed clusters via factorial kriging
Wu, Fu-Chun; Wang, Chi-Kuei; Huang, Guo-Hao
2018-05-01
Gravel-bed clusters are the most prevalent microforms that affect local flows and sediment transport. A growing consensus is that the practice of cluster delineation should be based primarily on bed topography rather than grain sizes. Here we present a novel approach for cluster delineation using patch-scale high-resolution digital elevation models (DEMs). We use a geostatistical interpolation method, i.e., factorial kriging, to decompose the short- and long-range (grain- and microform-scale) DEMs. The required parameters are determined directly from the scales of the nested variograms. The short-range DEM exhibits a flat bed topography, yet individual grains are sharply outlined, making the short-range DEM a useful aid for grain segmentation. The long-range DEM exhibits a smoother topography than the original full DEM, yet groupings of particles emerge as small-scale bedforms, making the contour percentile levels of the long-range DEM a useful tool for cluster identification. Individual clusters are delineated using the segmented grains and identified clusters via a range of contour percentile levels. Our results reveal that the density and total area of delineated clusters decrease with increasing contour percentile level, while the mean grain size of clusters and average size of anchor clast (i.e., the largest particle in a cluster) increase with the contour percentile level. These results support the interpretation that larger particles group as clusters and protrude higher above the bed than other smaller grains. A striking feature of the delineated clusters is that anchor clasts are invariably greater than the D90 of the grain sizes even though a threshold anchor size was not adopted herein. The average areal fractal dimensions (Hausdorff-Besicovich dimensions of the projected areas) of individual clusters, however, demonstrate that clusters delineated with different contour percentile levels exhibit similar planform morphologies. Comparisons with a
-
UNLV Information Science Research Institute quarterly progress report
International Nuclear Information System (INIS)
Nartker, T.A.
1994-01-01
Sections of this report include: symposium activity, staff activity, document analysis program, text-retrieval program, institute activity, etc. It is believed that as large, complete collections of documents become available in digital libraries, users will demand complete interaction with the information; document access mechanisms will have to grow beyond keywords and full-text searches to include browsing, searching of images, and searching on basis of abstract concepts. It is proposed to study the microform document conversion process, including image preprocessing, recognition, postprocessing for extracting information, and natural language techniques. Characterization of algorithms will allow generation of a system that automatically adapts to a wide range of image quality, thereby allowing large-scale conversion efforts. It is proposed to focus first on the NSF Antarctic database (approx. 55,000 documents)
-
UNLV Information Science Research Institute quarterly progress report
Energy Technology Data Exchange (ETDEWEB)
Nartker, T.A.
1994-03-31
Sections of this report include: symposium activity, staff activity, document analysis program, text-retrieval program, institute activity, etc. It is believed that as large, complete collections of documents become available in digital libraries, users will demand complete interaction with the information; document access mechanisms will have to grow beyond keywords and full-text searches to include browsing, searching of images, and searching on basis of abstract concepts. It is proposed to study the microform document conversion process, including image preprocessing, recognition, postprocessing for extracting information, and natural language techniques. Characterization of algorithms will allow generation of a system that automatically adapts to a wide range of image quality, thereby allowing large-scale conversion efforts. It is proposed to focus first on the NSF Antarctic database (approx. 55,000 documents).
-
Energy Technology Data Exchange (ETDEWEB)
Subrahmanyam, A [Semiconductor Physics Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Barik, Ullash Kumar [Semiconductor Physics Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India)
2007-03-15
Indium ({approx}10 at.%)-doped silver oxide (AIO) thin films have been prepared on glass substrates at room temperature (300 K) by reactive DC magnetron sputtering technique using an alloy target made of pure (99.99%) silver and indium (90:10 at.%) metals. The oxygen flow rates have been varied in the range 0.00-3.44 sccm during sputtering. The X-ray diffraction data on these indium-doped silver oxide films show polycrystalline nature. With increasing oxygen flow rate, the carrier concentration, the Hall mobility and the electron mean free path decrease. These films show a very low positive temperature coefficient of resistivity {approx}3.40x10{sup -8} ohm-cm/K. The work function values for these films (measured by Kelvin probe technique) are in the range 4.81-5.07 eV. The high electrical resistivity indicate that the films are in the island state (size effects). Calculations of the partial ionic charge (by Sanderson's theory) show that indium doping in silver oxide thin films enhance the ionicity.
-
International Nuclear Information System (INIS)
Subrahmanyam, A.; Barik, Ullash Kumar
2007-01-01
Indium (∼10 at.%)-doped silver oxide (AIO) thin films have been prepared on glass substrates at room temperature (300 K) by reactive DC magnetron sputtering technique using an alloy target made of pure (99.99%) silver and indium (90:10 at.%) metals. The oxygen flow rates have been varied in the range 0.00-3.44 sccm during sputtering. The X-ray diffraction data on these indium-doped silver oxide films show polycrystalline nature. With increasing oxygen flow rate, the carrier concentration, the Hall mobility and the electron mean free path decrease. These films show a very low positive temperature coefficient of resistivity ∼3.40x10 -8 ohm-cm/K. The work function values for these films (measured by Kelvin probe technique) are in the range 4.81-5.07 eV. The high electrical resistivity indicate that the films are in the island state (size effects). Calculations of the partial ionic charge (by Sanderson's theory) show that indium doping in silver oxide thin films enhance the ionicity
-
Energy Technology Data Exchange (ETDEWEB)
Kumar Barik, Ullash; Srinivasan, S; Nagendra, C L; Subrahmanyam, A
2003-04-01
Silver oxide thin films have been prepared on soda lime glass substrates at room temperature (300 K) by reactive DC Magnetron sputtering technique using pure silver metal target; the oxygen flow rates have been varied in the range 0.00-2.01 sccm. The X-ray diffraction data on these films show a systematic change from metallic silver to silver (sub) oxides. The electrical resistivity increases with increasing oxygen flow. The films show a p-type behavior (by both Hall and Seebeck measurements) for the oxygen flow rates of 0.54, 1.09 and 1.43 sccm. The refractive index of the films (at 632.8 nm) decreases with increasing oxygen content and is in the range 1.167-1.145, whereas the p-type films show a higher refractive index (1.186-1.204). The work function of these silver oxide films has been measured by Kelvin Probe technique. The results, in specific, the p-type conductivity in the silver oxide films, have been explained on the basis of the theory of partial ionic charge proposed by Sanderson.
-
International Nuclear Information System (INIS)
Kumar Barik, Ullash; Srinivasan, S.; Nagendra, C.L.; Subrahmanyam, A.
2003-01-01
Silver oxide thin films have been prepared on soda lime glass substrates at room temperature (300 K) by reactive DC Magnetron sputtering technique using pure silver metal target; the oxygen flow rates have been varied in the range 0.00-2.01 sccm. The X-ray diffraction data on these films show a systematic change from metallic silver to silver (sub) oxides. The electrical resistivity increases with increasing oxygen flow. The films show a p-type behavior (by both Hall and Seebeck measurements) for the oxygen flow rates of 0.54, 1.09 and 1.43 sccm. The refractive index of the films (at 632.8 nm) decreases with increasing oxygen content and is in the range 1.167-1.145, whereas the p-type films show a higher refractive index (1.186-1.204). The work function of these silver oxide films has been measured by Kelvin Probe technique. The results, in specific, the p-type conductivity in the silver oxide films, have been explained on the basis of the theory of partial ionic charge proposed by Sanderson
-
Energy Technology Data Exchange (ETDEWEB)
Valente, J.S.; Figueras, F.; Gravelle, M.; Kumbhar, P.; Lopez, J.; Besse, J.P.
2000-01-25
Carbonated layered double hydroxides (LDHs) containing Al, Fe, or Cr in a Mg(OH){sub 2} matrix or Al dissolved in hydroxides of Mg, Cu, Ni, Co, or Zn are used as precursors of basic catalysts. Decarbonation is studied by thermal analysis. The average basic strength, evaluated by the decarbonation temperature, is related to the partial charge of oxygen in the LDHs obtained from the Sanderson theory of electronegativity. The enthalpy of adsorption of CO{sub 2} on the resulting mixed oxides is measured by calorimetry. A homogeneous surface is generally observed for CO{sub 2} adsorption, with initial heats of adsorption close to those reported for MgO. The number of sites determined by this method is proportional to the rate constants for {beta}-isophorone isomerization, suggesting that both techniques measure surface properties. The layered structure in which OH{sup {minus}} is the compensating anion can be re-formed by hydration. This process does not appreciably change the adsorption of CO{sub 2}; thus, oxygens and hydroxyls show similar basic strengths in this case.
-
A Guide to the Microform Collections of the USMA (United States Military Academy) Library,
1983-01-01
period. One may find the earliest editions of Chaucer, Spenser, Shakespeare , More, Erasumus, and Bacon. Military, legal, royal and other public...Information Service, Inc., provides reference and information retrieval services to Congressional publications and public lava. As a companion to its
-
Novel Sonic Hedgehog Mutation in a Couple with Variable Expression of Holoprosencephaly
Directory of Open Access Journals (Sweden)
M. Aguinaga
2011-01-01
Full Text Available Holoprosencephaly (HPE is the most common developmental defect of the forebrain and midface in humans. sporadic and inherited mutations in the human sonic hedgehog (SHH gene cause 37% of familial HPE. A couple was referred to our unit with a family history of two spontaneous first trimester miscarriages and a daughter with HPE who presented early neonatal death. The father had a repaired median cleft lip, absence of central incisors, facial medial hypoplasia, and cleft palate. Intelligence and a brain CT scan were normal. Direct paternal sequencing analysis showed a novel nonsense mutation (W127X. Facial characteristics are considered as HPE microforms, and the pedigree suggested autosomal dominant inheritance with a variable expression of the phenotype. This study reinforces the importance of an exhaustive evaluation of couples with a history of miscarriages and neonatal deaths with structural defects.
-
Deformations in micro extrusion of metals
Directory of Open Access Journals (Sweden)
J. Piwnik
2010-07-01
Full Text Available Production technologies of small dimensions metallic elements are known for a long time. They are produced by machining methods:turning, milling, polishing. Recently, methods for manufacturing small details by forming are developed – microforming. This process ischaracterized by the high dimensions accuracy and the surface smoothness of received items and the high production rate. When a forming process is scaled down to micro dimensions, the microstructure of the workpiece, the surface topology of the workpiece and that of the tooling remain unchanged. Size effect is appearing. This paper analyses specifications of a metal extrusion in micro scale. To determine the impact of the tool surface roughness on deformation process the numerical model of roughness as triangle wave were developed. In paper the influence of the wave presence on the material flow is described. Impact of the forming conditions on extrusion forces there is also characterized.
-
Directory of Open Access Journals (Sweden)
Bijoy MUKHERJEE
2012-06-01
Full Text Available Debates in the philosophy of science typically take place around issues such as realism and theory change. Recently, the debate has been reformulated to bring in the role of experiments in the context of theory change. As regards realism, Ian Hacking’s contribution has been to introduce ‘intervention’ as the basis of realism. He also proposed, following Imre Lakatos, to replace the issue of truth with progress and rationality. In this context we examine the case of the vitalism — reductionism debate in biology inspired by the works of Indian physicist-turned-biologist Jagadish Chandra Bose (1858–1937, in the early twentieth century. Both camps had their characteristic hardcores. Vitalists led by John S. Burdon-Sanderson and Augustus D. Waller accepted religious metaphysics to support their research programme, which ultimately degenerated. Bose worked more with the ideals of science such as Occam’s razor, large-scale systematization of phenomena and novel prediction. I argue that his religious metaphysics, instead of acting as a protective shield, helped him to consolidate his position and allowed further problem shift resulting in a research programme that involved consciousness too. His research programme remains relevant even today.
-
A SAR and QSAR study of new artemisinin compounds with antimalarial activity.
Santos, Cleydson Breno R; Vieira, Josinete B; Lobato, Cleison C; Hage-Melim, Lorane I S; Souto, Raimundo N P; Lima, Clarissa S; Costa, Elizabeth V M; Brasil, Davi S B; Macêdo, Williams Jorge C; Carvalho, José Carlos T
2013-12-30
The Hartree-Fock method and the 6-31G** basis set were employed to calculate the molecular properties of artemisinin and 20 derivatives with antimalarial activity. Maps of molecular electrostatic potential (MEPs) and molecular docking were used to investigate the interaction between ligands and the receptor (heme). Principal component analysis and hierarchical cluster analysis were employed to select the most important descriptors related to activity. The correlation between biological activity and molecular properties was obtained using the partial least squares and principal component regression methods. The regression PLS and PCR models built in this study were also used to predict the antimalarial activity of 30 new artemisinin compounds with unknown activity. The models obtained showed not only statistical significance but also predictive ability. The significant molecular descriptors related to the compounds with antimalarial activity were the hydration energy (HE), the charge on the O11 oxygen atom (QO11), the torsion angle O1-O2-Fe-N2 (D2) and the maximum rate of R/Sanderson Electronegativity (RTe+). These variables led to a physical and structural explanation of the molecular properties that should be selected for when designing new ligands to be used as antimalarial agents.
-
A SAR and QSAR Study of New Artemisinin Compounds with Antimalarial Activity
Directory of Open Access Journals (Sweden)
Cleydson Breno R. Santos
2013-12-01
Full Text Available The Hartree-Fock method and the 6-31G** basis set were employed to calculate the molecular properties of artemisinin and 20 derivatives with antimalarial activity. Maps of molecular electrostatic potential (MEPs and molecular docking were used to investigate the interaction between ligands and the receptor (heme. Principal component analysis and hierarchical cluster analysis were employed to select the most important descriptors related to activity. The correlation between biological activity and molecular properties was obtained using the partial least squares and principal component regression methods. The regression PLS and PCR models built in this study were also used to predict the antimalarial activity of 30 new artemisinin compounds with unknown activity. The models obtained showed not only statistical significance but also predictive ability. The significant molecular descriptors related to the compounds with antimalarial activity were the hydration energy (HE, the charge on the O11 oxygen atom (QO11, the torsion angle O1-O2-Fe-N2 (D2 and the maximum rate of R/Sanderson Electronegativity (RTe+. These variables led to a physical and structural explanation of the molecular properties that should be selected for when designing new ligands to be used as antimalarial agents.
-
Design study of plastic film heat exchanger
Guyer, E. C.; Brownell, D. L.
1986-02-01
This report presents the results of an effort to develop and design a unique thermoplastic film heat exchanger for use in an industrial heat pump evaporator system and other energy recovery applications. The concept for the exchanger is that of individual heat exchange elements formed by two adjoining and freely hanging plastic films. Liquid flows downward in a regulated fashion between the films due to the balance of hydrostatic and frictional forces. The fluid stream on the outside of film may be a free-falling liquid film, a condensing gas, or a noncondensing gas. The flow and structural principles are similar to those embodied in an earlier heat exchange system developed for use in waste water treatment systems (Sanderson). The design allows for high heat transfer rates while working within the thermal and structural limitations of thermoplastic materials. The potential of this new heat exchanger design lies in the relatively low cost of plastic film and the high inherent corrosion and fouling resistance. This report addresses the selection of materials, the potential heat transf er performance, the mechanical design and operation of a unit applied in a low pressure steam recovery system, and the expected selling price in comparison to conventional metallic shell and tube heat exchangers.
-
The role of interleukin-5 (IL-5 in vivo: studies with IL-5 deficient mice
Directory of Open Access Journals (Sweden)
Klaus I Matthaei
1997-12-01
Full Text Available Eosinophil recruitment is a characteristic feature of a number of pathological conditions and was the topic of the recent International Symposium on allergic inflammation, asthma, parasitic and infectious diseases (Rio de Janeiro, June 3-5, 1996. Since interleukin5 (IL5 is believed to regulate the growth, differentiation and activation of eosinophils (Coffman et al. 1989, Sanderson 1992, the role of eosinophils and IL5 are closely linked. Although IL5 specifically regulates eosinophilia in vivo and this is its most well established activity, it is becoming clear that IL5 also has other biological effects. The recent derivation of an IL5 deficient mouse (Kopf et al. 1996, provides a model for exploring not only the role of IL5 and eosinophils but also other novel activities of IL5. Of note is that although the IL5 deficient mice cannot elicit a pronounced eosinophilia in response to inflammatory stimulation following aeroallergen challenge or parasite infection they still produce basal levels of eosinophils that appear to be morphologically and functionally normal. However, the basal levels of eosinophils appear insufficient for normal host defence as IL5 deficiency has now been shown to compromise defence against several helminth infections. In addition, IL5 deficient mice appear to have functional deficiencies in B-1 B lymphocytes and in IgA production.
-
Aged Tg2576 mice are impaired on social memory and open field habituation tests.
Deacon, R M J; Koros, E; Bornemann, K D; Rawlins, J N P
2009-02-11
In a previous publication [Deacon RMJ, Cholerton LL, Talbot K, Nair-Roberts RG, Sanderson DJ, Romberg C, et al. Age-dependent and -independent behavioral deficits in Tg2576 mice. Behav Brain Res 2008;189:126-38] we found that very few cognitive tests were suitable for demonstrating deficits in Tg2576 mice, an amyloid over-expression model of Alzheimer's disease, even at 23 months of age. However, in a retrospective analysis of a separate project on these mice, tests of social memory and open field habituation revealed large cognitive impairments. Controls showed good open field habituation, but Tg2576 mice were hyperactive and failed to habituate. In the test of social memory for a juvenile mouse, controls showed considerably less social investigation on the second meeting, indicating memory of the juvenile, whereas Tg2576 mice did not show this decrement.As a control for olfactory sensitivity, on which social memory relies, the ability to find a food pellet hidden under wood chip bedding was assessed. Tg2576 mice found the pellet as quickly as controls. As this test requires digging ability, this was independently assessed in tests of burrowing and directly observed digging. In line with previous results and the hippocampal dysfunction characteristic of aged Tg2576 mice, they both burrowed and dug less than controls.
-
Dynamical passage to approximate equilibrium shapes for spinning, gravitating rubble asteroids
Sharma, Ishan; Jenkins, James T.; Burns, Joseph A.
2009-03-01
Many asteroids are thought to be particle aggregates held together principally by self-gravity. Here we study — for static and dynamical situations — the equilibrium shapes of spinning asteroids that are permitted for rubble piles. As in the case of spinning fluid masses, not all shapes are compatible with a granular rheology. We take the asteroid to always be an ellipsoid with an interior modeled as a rigid-plastic, cohesion-less material with a Drucker-Prager yield criterion. Using an approximate volume-averaged procedure, based on the classical method of moments, we investigate the dynamical process by which such objects may achieve equilibrium. We first collapse our dynamical approach to its statical limit to derive regions in spin-shape parameter space that allow equilibrium solutions to exist. At present, only a graphical illustration of these solutions for a prolate ellipsoid following the Drucker-Prager failure law is available [Sharma, I., Jenkins, J.T., Burns, J.A., 2005a. Bull. Am. Astron. Soc. 37, 643; Sharma, I., Jenkins, J.T., Burns, J.A., 2005b. Equilibrium shapes of ellipsoidal soil asteroids. In: García-Rojo, R., Hermann, H.J., McNamara, S. (Eds.), Proceedings of the 5th International Conference on Micromechanics of Granular Media, vol. 1. A.A. Balkema, UK; Holsapple, K.A., 2007. Icarus 187, 500-509]. Here, we obtain the equilibrium landscapes for general triaxial ellipsoids, as well as provide the requisite governing formulae. In addition, we demonstrate that it may be possible to better interpret the results of Richardson et al. [Richardson, D.C., Elankumaran, P., Sanderson, R.E., 2005. Icarus 173, 349-361] within the context of a Drucker-Prager material. The graphical result for prolate ellipsoids in the static limit is the same as those of Holsapple [Holsapple, K.A., 2007. Icarus 187, 500-509] because, when worked out, his final equations will match ours. This is because, though the formalisms to reach these expressions differ, in statics
-
Peker, Mevlut Fatih
Micro-forming studies have been more attractive in recent years because of miniaturization trend. One of the promising metal forming processes, micro-stamping, provides durability, strength, surface finish, and low cost for metal products. Hence, it is considered a prominent method for fabricating bipolar plates (BPP) with micro-channel arrays on large metallic surfaces to be used in Proton Exchange Membrane Fuel Cells (PEMFC). Major concerns in micro-stamping of high volume BPPs are surface interactions between micro-stamping dies and blank metal plates, and tribological changes. These concerns play a critical role in determining the surface quality, channel formation, and dimensional precision of bipolar plates. The surface quality of BPP is highly dependent on the micro-stamping die surface, and process conditions due to large ratios of surface area to volume (size effect) that cause an increased level of friction and wear issues at the contact interface. Due to the high volume and fast production rates, BPP surface characteristics such as surface roughness, hardness, and stiffness may change because of repeated interactions between tool (micro-forming die) and workpiece (sheet blank of interest). Since the surface characteristics of BPPs have a strong effect on corrosion and contact resistance of bipolar plates, and consequently overall fuel cell performance, evolution of surface characteristics at the tool and workpiece should be monitored, controlled, and kept in acceptable ranges throughout the long production cycles to maintain the surface quality. Compared to macro-forming operations, tribological changes in micro-forming process are bigger challenges due to their dominance and criticality. Therefore, tribological size effect should be considered for better understanding of tribological changes in micro-scale. The integrity of process simulation to the experiments, on the other hand, is essential. This study describes an approach that aims to investigate
-
Experimental and theoretical study on minimum achievable foil thickness during asymmetric rolling.
Directory of Open Access Journals (Sweden)
Delin Tang
Full Text Available Parts produced by microforming are becoming ever smaller. Similarly, the foils required in micro-machines are becoming ever thinner. The asymmetric rolling technique is capable of producing foils that are thinner than those produced by the conventional rolling technique. The difference between asymmetric rolling and conventional rolling is the 'cross-shear' zone. However, the influence of the cross-shear zone on the minimum achievable foil thickness during asymmetric rolling is still uncertain. In this paper, we report experiments designed to understand this critical influencing factor on the minimum achievable thickness in asymmetric rolling. Results showed that the minimum achievable thickness of rolled foils produced by asymmetric rolling with a rolling speed ratio of 1.3 can be reduced to about 30% of that possible by conventional rolling technique. Furthermore, the minimum achievable thickness during asymmetric rolling could be correlated to the cross-shear ratio, which, in turn, could be related to the rolling speed ratio. From the experimental results, a formula to calculate the minimum achievable thickness was established, considering the parameters cross-shear ratio, friction coefficient, work roll radius, etc. in asymmetric rolling.
-
The significance of radiological control documentation in litigation
International Nuclear Information System (INIS)
Lodde, G.M.; Murphy, T.D.
1988-01-01
Commercial nuclear facilities accumulate radiological control program data and documents generated and retained pursuant to regulatory, license, and technical specification requirements. During and following the Three Mile Island Unit 2 (TMI-2) accident, many documents were produced that would not normally have been produced. Shortly after the accident, the US Nuclear Regulatory Commission (NRC) issued an order requiring the retention of all data, including documentary material and physical samples relating to the TMI-2 accident (44 Fed. Reg. 30788, May 29, 1979). Three years later, the NRC vacated the requirement to retain catalogued physical samples, provided the radioactivity data had been properly recorded, allowing disposal of many samples. After the TMI-2 accident, GPU Nuclear Corporation (GPU) designed and implemented an effective and efficient record management program for TMI. This Computer-Assisted Records and Information Retrieval System (CARIRS) was developed to assess the official record for TMI, which is maintained as a microform. GPU also retains hard copies of selected radiological control documents for potential litigation. This paper describes the use of radiological control documentation in the postaccident litigation and the magnitude of document production required to support that litigation
-
Micro-deformation behavior in micro-compression with high-purity aluminum processed by ECAP
Directory of Open Access Journals (Sweden)
Xu Jie
2015-01-01
Full Text Available Ultrafine-grained (UFG materials have a potential for applications in micro-forming since grain size appears to be the dominant factor which determines the limiting size of the geometrical features. In this research, high-purity Al was processed by equal-channel angular pressing (ECAP at room temperature through 1–8 passes. Analysis shows that processing by ECAP produces a UFG structure with a grain size of ~1.3 μm and with microhardness and microstructural homogeneity. Micro-compression testing was carried out with different specimen dimensions using the annealed sample and after ECAP processing through 1–8 passes. The results show the flow stress increases significantly after ECAP processing by comparison with the annealed material. The flow stress generally reaches a maximum value after 2 passes which is consistent with the results of microhardness. The flow stress decreases with decreasing specimen diameter from 4 mm to 1 mm which demonstrates that size effects also exist in the ultrafine-grained materials. However, the deformation mechanism in ultrafine-grained pure Al changes from strain strengthening to softening by dynamic recovery by comparison with the annealed material.
-
Experimental and theoretical study on minimum achievable foil thickness during asymmetric rolling.
Tang, Delin; Liu, Xianghua; Song, Meng; Yu, Hailiang
2014-01-01
Parts produced by microforming are becoming ever smaller. Similarly, the foils required in micro-machines are becoming ever thinner. The asymmetric rolling technique is capable of producing foils that are thinner than those produced by the conventional rolling technique. The difference between asymmetric rolling and conventional rolling is the 'cross-shear' zone. However, the influence of the cross-shear zone on the minimum achievable foil thickness during asymmetric rolling is still uncertain. In this paper, we report experiments designed to understand this critical influencing factor on the minimum achievable thickness in asymmetric rolling. Results showed that the minimum achievable thickness of rolled foils produced by asymmetric rolling with a rolling speed ratio of 1.3 can be reduced to about 30% of that possible by conventional rolling technique. Furthermore, the minimum achievable thickness during asymmetric rolling could be correlated to the cross-shear ratio, which, in turn, could be related to the rolling speed ratio. From the experimental results, a formula to calculate the minimum achievable thickness was established, considering the parameters cross-shear ratio, friction coefficient, work roll radius, etc. in asymmetric rolling.
-
Directory of Open Access Journals (Sweden)
Christopher Kitching
2000-06-01
Full Text Available In the United Kingdom (as in many other countries increasing attention is being paid to the importance of each library and archive having a written preservation strategy endorsed by its governing body. So increasingly we are asking: where does „preservation“ begin and what are its top priorities? Some would say preservation begins with the definition of collecting policies to ensure that only relevant items are acquired in the first place, and therefore that no unnecessary costs are incurred on the long-term care of unwanted and unconsulted items. Others might argue that the first priority must be the careful appraisal of existing holdings to determine their preservation and conservation requirements and to prioritise their treatment. Or should preservation begin with damage-limitation: restricting the physical handling of books and documents, on the one hand by providing whenever possible surrogate copies in digital formats or microform, and on the other hand by offering at least basic protection through appropriate boxing and packaging? This, surely, goes hand-in-hand with the education of staff and readers about the importance of treating rare or unique materials with proper respect.
-
New concept of age(ing: Prospective age
Directory of Open Access Journals (Sweden)
Devedžić Mirjana
2012-01-01
Full Text Available While the last century was the century of world population growth, according to demographers, the XXI century will be century of population aging. Statistics undoubtedly show that number of elderly will continue it’s growth in the future. If old age is seen as period of life with reduced physical and mental capabilities and increased disability, and demographic aging as increase of dependent population, trends are quite disturbing, at least in certain societal segments. In developed countries, this population category is no longer treated as passive or as a "burden of society" and efforts are made for better social inclusion of older people. In contrast to growing interest in this phenomenon, the concepts that define the aging of the population remained stagnant. The aim of this paper is to introduce into domestic literature the term "prospective age" as a dynamic category which is more affected with socio-historical conditions, not only with biological as traditional definition of aging suggested. Papers written by Sanderson and Scherbov offer new methodological options for study of population aging, because it takes into account the biometric rather than chronological approach. Calculation of prospective years is a simple operation that requires pair of the same number of remained life expectancy from life tables for two different periods (the year of concern is index, and the one we are comparing with is standard year, so that phrase "40s is the new 30s" or "70s the new 60s" gets scientific foundation. Average remaining years of life represent a realistic indicator suggesting increased capacity, activity and vitality of individuals, which is due to accepted demographic parameters still considered old. „Prospective threshold“ is defined as the age when life expectancy falls below 15 years (it is subjective choice made by Sanderson and Scherbov, which is also used in this paper and during the elaboration of these ideas three demographic
-
A multi-scale controlled tissue engineering scaffold prepared by 3D printing and NFES technology
Directory of Open Access Journals (Sweden)
Feifei Yan
2014-03-01
Full Text Available The current focus in the field of life science is the use of tissue engineering scaffolds to repair human organs, which has shown great potential in clinical applications. Extracellular matrix morphology and the performance and internal structure of natural organs are required to meet certain requirements. Therefore, integrating multiple processes can effectively overcome the limitations of the individual processes and can take into account the needs of scaffolds for the material, structure, mechanical properties and many other aspects. This study combined the biological 3D printing technology and the near-field electro-spinning (NFES process to prepare a multi-scale controlled tissue engineering scaffold. While using 3D printing technology to directly prepare the macro-scaffold, the compositing NFES process to build tissue micro-morphology ultimately formed a tissue engineering scaffold which has the specific extracellular matrix structure. This scaffold not only takes into account the material, structure, performance and many other requirements, but also focuses on resolving the controllability problems in macro- and micro-forming which further aim to induce cell directed differentiation, reproduction and, ultimately, the formation of target tissue organs. It has in-depth immeasurable significance to build ideal scaffolds and further promote the application of tissue engineering.
-
Correlation between vegetation pattern and microtopography in periglacial areas of the Central Alps
Directory of Open Access Journals (Sweden)
Gerdol, Renato
1990-06-01
Full Text Available The distributional patterns of plant species were analyzed within periglacial microforms belonging to the collective groups of patterned grounds and sorted stripes In the Ortles-Cevedale group (Lombardy, Italy. The edges of primitive polygons are practically free of vegetation, whilst the central areas are colonized by pioneer plants of detritic slopes. This is clearly correlated with a low degree of sediment sorting. The morphological evolution of the forms proceeds at a faster rate at the edge of polygons than in the central areas. Vegetation, on the other hand, colonizes the coarse debris at the polygons’ edges slowly but colonizes the fine material in the central areas actively. The centre of the most evolved polygons is covered by a carpet of Salix herbacea. Age determinations of Salix shoots are not useful for dating purposes, but provide Information about the local microclimate.
[es] Se han analizado los modelos de distribución de especies vegetales en microformas periglaciares pertenecientes al tipo de suelos estructurales en el Ortles-Cevedale (Lombardía, Italia. Los límites de los polígonos de piedras están prácticamente libres de vegetación, mientras las áreas centrales están colonizadas por plantas pioneras de laderas pedregosas. La evolución morfológica actúa a mayor velocidad en el borde de los polígonos que en las áreas centrales. Por otro lado, la vegetación coloniza lentamente los bordes de los polígonos, y más activamente las zonas centrales. El centro de la mayoría de los polígonos está cubierto por un manto de Salix herbacea. La determinación de la edad de los vástagos de Salix no ha sido un método útil a efectos cronológicos, pero proporciona información sobre el microclima local.
[fr] On étude les modèles de distribution d'espèces végétaux dans microformes périglaciaires appartenants au type de sols structurales dans l'Ortles-Cevedale (Lombardie -
Determination of material distribution in heading process of small bimetallic bar
Presz, Wojciech; Cacko, Robert
2018-05-01
The electrical connectors mostly have silver contacts joined by riveting. In order to reduce costs, the core of the contact rivet can be replaced with cheaper material, e.g. copper. There is a wide range of commercially available bimetallic (silver-copper) rivets on the market for the production of contacts. Following that, new conditions in the riveting process are created because the bi-metal object is riveted. In the analyzed example, it is a small size object, which can be placed on the border of microforming. Based on the FEM modeling of the load process of bimetallic rivets with different material distributions, the desired distribution was chosen and the choice was justified. Possible material distributions were parameterized with two parameters referring to desirable distribution characteristics. The parameter: Coefficient of Mutual Interactions of Plastic Deformations and the method of its determination have been proposed. The parameter is determined based of two-parameter stress-strain curves and is a function of these parameters and the range of equivalent strains occurring in the analyzed process. The proposed method was used for the upsetting process of the bimetallic head of the electrical contact. A nomogram was established to predict the distribution of materials in the head of the rivet and the appropriate selection of a pair of materials to achieve the desired distribution.
-
EBSD analysis of plastic deformation of copper foils by flexible pad laser shock forming
Energy Technology Data Exchange (ETDEWEB)
Nagarajan, Balasubramanian; Castagne, Sylvie [Nanyang Technological University, SIMTech-NTU Joint Laboratory (Precision Machining), Singapore (Singapore); Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore (Singapore); Wang, Zhongke; Zheng, H.Y. [Nanyang Technological University, SIMTech-NTU Joint Laboratory (Precision Machining), Singapore (Singapore); Singapore Institute of Manufacturing Technology, Machining Technology Group, Singapore (Singapore)
2015-11-15
Flexible pad laser shock forming (FPLSF) is a new mold-free microforming process that induces high-strain-rate plastic deformation in thin metallic foils using laser-induced shock pressure and a hyperelastic flexible pad. This paper studies the plastic deformation behavior of copper foils formed through FPLSF by investigating surface hardness and microstructure. The microstructure of the foil surface before and after FPLSF is analyzed by electron backscatter diffraction technique using grain size distribution and grain boundary misorientation angle as analysis parameters. The surface hardness of the craters experienced a significant improvement after FPLSF; the top crater surface being harder than the bottom surface. The microstructure of the copper foil surface after FPLSF was found to be dominated by grain elongation, along with minor occurrences of subgrain formation, grain refinement, and high dislocation density regions. The results indicate that the prominent plastic deformation mechanism in FPLSF is strain hardening behavior rather than the typical adiabatic softening effect known to be occurring at high-strain-rates for processes such as electromagnetic forming, explosive forming, and laser shock forming. This significant difference in FPLSF is attributed to the concurrent reduction in plastic strain, strain rate, and the inertia effects, resulting from the FPLSF process configuration. Correspondingly, different deformation behaviors are experienced at top and bottom surfaces of the deformation craters, inducing the change in surface hardness and microstructure profiles. (orig.)
-
Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.
2015-02-01
Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1-3 years; experimental) and older drained (10-13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The CO2-C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2-C sink of 92, 70 and 76 g m-2, the experimental site was a CO2-C source of 14, 57 and 135 g m-2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2-C m-2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m-2) than at the experimental (58 and 55 g C m-2) and control (52 and 46 g C m-2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained
-
The potential impact of hydrogen energy use on the atmosphere
van Ruijven, B. J.; Lamarque, J. F.; van Vuuren, D. P.; Kram, T.; Eerens, H.
2009-04-01
Energy models show very different trajectories for future energy systems (partly as function of future climate policy). One possible option is a transition towards a hydrogen-based energy system. The potential impact of such hydrogen economy on atmospheric emissions is highly uncertain. On the one hand, application of hydrogen in clean fuel cells reduces emissions of local air pollutants, like SOx and NOx. On the other hand, emissions of hydrogen from system leakages are expected to change the atmospheric concentrations and behaviour (see also Price et al., 2007; Sanderson et al., 2003; Schultz et al., 2003; Tromp et al., 2003). The uncertainty arises from several sources: the expected use of hydrogen, the intensity of leakages and emissions, and the atmospheric chemical behaviour of hydrogen. Existing studies to the potential impacts of a hydrogen economy on the atmosphere mostly use hydrogen emission scenarios that are based on simple assumptions. This research combines two different modelling efforts to explore the range of impacts of hydrogen on atmospheric chemistry. First, the potential role of hydrogen in the global energy system and the related emissions of hydrogen and other air pollutants are derived from the global energy system simulation model TIMER (van Vuuren, 2007). A set of dedicated scenarios on hydrogen technology development explores the most pessimistic and optimistic cases for hydrogen deployment (van Ruijven et al., 2008; van Ruijven et al., 2007). These scenarios are combined with different assumptions on hydrogen emission factors. Second, the emissions from the TIMER model are linked to the NCAR atmospheric model (Lamarque et al., 2005; Lamarque et al., 2008), in order to determine the impacts on atmospheric chemistry. By combining an energy system model and an atmospheric model, we are able to consistently explore the boundaries of both hydrogen use, emissions and impacts on atmospheric chemistry. References: Lamarque, J.-F., Kiehl, J. T
-
Hormiga, Gustavo; Arnedo, Miquel; Gillespie, Rosemary G
2003-02-01
Spiders of the recently described linyphiid genus Orsonwelles (Araneae, Linyphiidae) are one of the most conspicuous groups of terrestrial arthropods of Hawaiian native forests. There are 13 known Orsonwelles species, and all are single- island endemics. This radiation provides an excellent example of insular gigantism. We reconstructed the cladistic relationships of Orsonwelles species using a combination of morphological and molecular characters (both mitochondrial and nuclear sequences) within a parsimony framework. We explored and quantified the contribution of different character partitions and their sensitivity to changes in the traditional parameters (gap, transition, and transversion costs). The character data show a strong phylogenetic signal, robust to parameter changes. The monophyly of the genus Orsonwelles is strongly supported. The parsimony analysis of all character evidence combined recovered a clade with of all the non-Kauai Orsonwelles species; the species from Kauai form a paraphyletic assemblage with respect to the latter former clade. The biogeographic pattern of the Hawaiian Orsonwelles species is consistent with colonization by island progression, but alternative explanations for our data exist. Although the geographic origin of the radiation remains unknown, it appears that the ancestral colonizing species arrived first on Kauai (or an older island). The ambiguity in the area cladogram (i.e., post-Oahu colonization) is not derived from conflicting or unresolved phylogenetic signal among Orsonwelles species but rather from the number of taxa on the youngest islands. Speciation in Orsonwelles occurred more often within islands (8 of the 12 cladogenic events) than between islands. A molecular clock was rejected for the sequence data. Divergence times were estimated by using the nonparametric rate smoothing method of Sanderson (1997, Mol. Biol. Evol. 14:1218-1231) and the available geological data for calibration. The results suggest that the
-
Directory of Open Access Journals (Sweden)
Ellison AC
2014-05-01
Full Text Available Ashton C Ellison, A John Campbell, M Clare Robertson, Gordon F SandersonDunedin School of Medicine, Department of Medicine, Dunedin, New ZealandBackground: Multifocal glasses (bifocals, trifocals, and progressives increase the risk of falling in elderly people, but how they do so is unclear. To explain why glasses with progressive addition lenses increase the risk of falls and whether this can be attributed to false projection, this study aimed to 1 map the prismatic displacement of a progressive lens, and 2 test whether this displacement impaired reaction time and accuracy.Methods: The reaction times of healthy ≥75-year-olds (31 participants were measured when grasping for a bar and touching a black line. Participants performed each test twice, wearing their progressives and new, matched single vision (distance glasses in random order. The line and bar targets were positioned according to the maximum and minimum prismatic displacement effect through the progressive lens, mapped using a focimeter.Results: Progressive spectacle lenses have large areas of prismatic displacement in the central visual axis and edges. Reaction time was faster for progressives compared with single vision glasses with a centrally-placed horizontal grab bar (mean difference 101 ms, P=0.011 [repeated measures analysis] and a horizontal black line placed 300 mm below center (mean difference 80 ms, P=0.007. There was no difference in accuracy between the two types of glasses.Conclusion: Older people appear to adapt to the false projection of progressives in the central visual axis. This adaptation means that swapping to new glasses or a large change in prescription may lead to a fall. Frequently updating glasses may be more beneficial.Keywords: fall prevention, false projection, stored visual spatial information
-
Gupta, Shikha; Basant, Nikita
2017-11-01
Designing of advanced oxidation process (AOP) requires knowledge of the aqueous phase hydroxyl radical ( ● OH) reactions rate constants (k OH ), which are strictly dependent upon the pH and temperature of the medium. In this study, pH- and temperature-dependent quantitative structure-property relationship (QSPR) models based on the decision tree boost (DTB) approach were developed for the prediction of k OH of diverse organic contaminants following the OECD guidelines. Experimental datasets (n = 958) pertaining to the k OH values of aqueous phase reactions at different pH (n = 470; 1.4 × 10 6 to 3.8 × 10 10 M -1 s -1 ) and temperature (n = 171; 1.0 × 10 7 to 2.6 × 10 10 M -1 s -1 ) were considered and molecular descriptors of the compounds were derived. The Sanderson scale electronegativity, topological polar surface area, number of double bonds, and halogen atoms in the molecule, in addition to the pH and temperature, were found to be the relevant predictors. The models were validated and their external predictivity was evaluated in terms of most stringent criteria parameters derived on the test data. High values of the coefficient of determination (R 2 ) and small root mean squared error (RMSE) in respective training (> 0.972, ≤ 0.12) and test (≥ 0.936, ≤ 0.16) sets indicated high generalization and predictivity of the developed QSPR model. Other statistical parameters derived from the training and test data also supported the robustness of the models and their suitability for screening new chemicals within the defined chemical space. The developed QSPR models provide a valuable tool for predicting the ● OH reaction rate constants of emerging new water contaminants for their susceptibility to AOPs.
-
Directory of Open Access Journals (Sweden)
MOHAMMAD H. FATEMI
2011-07-01
Full Text Available Quantitative structure–activity relationship (QSAR approaches were used to estimate the volume of distribution (Vd using an artificial neural network (ANN. The data set consisted of the volume of distribution of 129 pharmacologically important compounds, i.e., benzodiazepines, barbiturates, nonsteroidal anti-inflammatory drugs (NSAIDs, tricyclic anti-depressants and some antibiotics, such as betalactams, tetracyclines and quinolones. The descriptors, which were selected by stepwise variable selection methods, were: the Moriguchi octanol–water partition coefficient; the 3D-MoRSE-signal 30, weighted by atomic van der Waals volumes; the fragment-based polar surface area; the d COMMA2 value, weighted by atomic masses; the Geary autocorrelation, weighted by the atomic Sanderson electronegativities; the 3D-MoRSE – signal 02, weighted by atomic masses, and the Geary autocorrelation – lag 5, weighted by the atomic van der Waals volumes. These descriptors were used as inputs for developing multiple linear regressions (MLR and artificial neural network models as linear and non-linear feature mapping techniques, respectively. The standard errors in the estimation of Vd by the MLR model were: 0.104, 0.103 and 0.076 and for the ANN model: 0.029, 0.087 and 0.082 for the training, internal and external validation test, respectively. The robustness of these models were also evaluated by the leave-5-out cross validation procedure, that gives the statistics Q2 = 0.72 for the MLR model and Q2 = 0.82 for the ANN model. Moreover, the results of the Y-randomization test revealed that there were no chance correlations among the data matrix. In conclusion, the results of this study indicate the applicability of the estimation of the Vd value of drugs from their structural molecular descriptors. Furthermore, the statistics of the developed models indicate the superiority of the ANN over the MLR model.
-
Directory of Open Access Journals (Sweden)
Nabil Sayed Embabi
2014-06-01
Full Text Available Among the other coastal lakes of the Mediterranean northern coast of Egypt, Bardawil Lake is a unique lagoon, as it is fed only by seawater. The lagoon is composed of two main basins, and several other internal small basins interconnected to one another. Although the general geomorphologic characteristics are treated in some regional studies, we used a semi-automated approach based on a wide variety of digital image processing for mapping the major geomorphological landforms of the lake on a medium scale of 1:250,000. The approach is based primarily on data fusion of Landsat ETM+ image, and validated by other ancillary spatial data (e.g. topographic maps, Google images and GPS in situ data. Interpretations of high resolution space images by Google Earth and the large-scale topographic maps (1:25,000, in specific, revealed new microforms and some detailed geomorphologic aspects with the aid of GPS measurements. Small sand barriers, submerged sand dunes, tidal channels, fans and flats, and micro-lagoons are the recurrent forms in the lake. The approach used in this study could be widely applied to study the low-lying coastal lands along the Nile Delta. However, it is concluded from geological data and geomorphologic aspects that Bardawil Lake is of a tectonic origin; it was much deeper than it is currently, and has been filled with sediments mostly since the Flandrian transgression (∼8–6 ka bp.
-
Superplasticity and Micro-arrayed Deep-Drawing Behavior of Ni-Co/GO Nanocomposite
Wang, Guofeng; Zhao, Shanshan; Li, You; Yang, Chao; Liu, Siyu
2017-10-01
In this article, Ni-Co/GO nanocomposite was fabricated by AC pulse electrodeposition method. The room temperature strength tests and the superplasticity of the nanocomposite were investigated by the tensile tests. A 5 × 5 micro-arrayed deep-drawing die was designed to explore the feasibility of micro-forming. The as-deposited material has a narrow grain size distribution with a mean grain size of 50 nm. The addition of GO as a reinforcing phase can effectively enhance the room temperature tensile strength of the nanocomposite, but reduce the plasticity. When adding GO to the plating bath, a maximum elongation of 467% was observed for the specimen with a GO content of 0.01 g/L at 773 K and a strain rate of 1.67 × 10-3 s-1 by tensile tests. Micro-arrayed deep-drawing tests were subsequently performed with male die diameter of 0.58 mm and female die diameter of 0.8 mm. The experimental relative drawing height values were measured and compared with the deep-drawing parts without GO additive. It is found that the micro-arrayed deep-drawing with rigid male die at high temperature was feasible and forming parts with good shape could be got. The thickness distribution analysis of the deep-drawing parts showed that wall thickness changed ranging from 53 to 95 μm, and the thickness reduction at the punch fillet is the most obvious.
-
Wasisto, Hutomo Suryo; Yu, Feng; Doering, Lutz; Völlmeke, Stefan; Brand, Uwe; Bakin, Andrey; Waag, Andreas; Peiner, Erwin
2015-05-01
Silicon microprobe tips are fabricated and integrated with piezoresistive cantilever sensors for high-speed surface roughness scanning systems. The fabrication steps of the high-aspect-ratio silicon microprobe tips were started with photolithography and wet etching of potassium hydroxide (KOH) resulting in crystal-dependent micropyramids. Subsequently, thin conformal wear-resistant layer coating of aluminum oxide (Al2O3) was demonstrated on the backside of the piezoresistive cantilever free end using atomic layer deposition (ALD) method in a binary reaction sequence with a low thermal process and precursors of trimethyl aluminum and water. The deposited Al2O3 layer had a thickness of 14 nm. The captured atomic force microscopy (AFM) image exhibits a root mean square deviation of 0.65 nm confirming the deposited Al2O3 surface quality. Furthermore, vacuum-evaporated 30-nm/200-nm-thick Au/Cr layers were patterned by lift-off and served as an etch mask for Al2O3 wet etching and in ICP cryogenic dry etching. By using SF6/O2 plasma during inductively coupled plasma (ICP) cryogenic dry etching, micropillar tips were obtained. From the preliminary friction and wear data, the developed silicon cantilever sensor has been successfully used in 100 fast measurements of 5- mm-long standard artifact surface with a speed of 15 mm/s and forces of 60-100 μN. Moreover, the results yielded by the fabricated silicon cantilever sensor are in very good agreement with those of calibrated profilometer. These tactile sensors are targeted for use in high-aspect-ratio microform metrology.
-
Heathcote, Gary M; Bromage, Timothy G; Sava, Vincent J; Hanson, Douglas B; Anderson, Bruce E
2014-06-01
This study focuses on the gross anatomy, anatomic relations, microanatomy, and the meaning of three enigmatic, geographically patterned, and quasi-continuous superstructures of the posterior cranium. Collectively known as occipital superstructures (OSSs), these traits are the occipital torus tubercle (TOT), retromastoid process (PR), and posterior supramastoid tubercle (TSP). When present, TOT, PR, and TSP develop at posterior cranial attachment sites of the upper trapezius, superior oblique, and sternocleidomastoid muscles, respectively. Marked expression and co-occurrence of these OSSs are virtually circumscribed within Oceania and reach highest recorded frequencies in protohistoric Chamorros (CHamoru) of the Mariana Islands. Prior to undertaking scanning electron microscopy (SEM) work, our working multifactorial model for OSS development was that early-onset, long-term, and chronic activity-related microtrauma at enthesis sites led to exuberant reactive or reparative responses in a substantial minority of genetically predisposed (and mostly male) individuals. SEM imaging, however, reveals topographic patterning that questions, but does not negate, activity induction of these superstructures. Although OSSs appear macroscopically as relatively large and discrete phenomena, SEM findings reveal a unique, widespread, and seemingly systemic distribution of structures over the occipital surface that have the appearance of OSS microforms. Nevertheless, apparent genetic underpinnings, anatomic relationships with muscle entheses, and positive correlation of OSS development with humeral robusticity continue to suggest that these superstructures have potential to at once bear witness to Chamorro population history and inform osteobiographical constructions of chronic activity patterns in individuals bearing them. Further work is outlined that would illuminate the proximate and ultimate meanings of OSS. Copyright © 2014 Wiley Periodicals, Inc.
-
Classificação e tipologia dos lapiás. Contributo para uma terminologia das formas cársicas.
Directory of Open Access Journals (Sweden)
Maria Luísa Rodrigues
2012-06-01
Full Text Available Classification and types of karren. A contribution for a karst landforms terminology. The bibliography that refer to the forms developed in limestone rocks normally emphasizes the so called major karst forms (sinkholes, uvalas, poljes and fluvio-karstic forms, paying less attention to the so called minor karst forms, that are formed by the karren ones. In this particular field, the bibliography available in Portuguese is no exception. Hence the option of choosing this set of forms amongst all the wide range of karstic landforms, in addition to the fact that these smaller forms show better the existence of active dissolution processes at the surface that contribute decisively to the hydrologic underground karst activity. Most of the karren classifications are essentially descriptive favoring the morphology (forms and microforms, which leads to a multiplication of terms conferring a secondary role to the genesis and processes related to its formation. Therefore, we tried to develop a methodology to classify the karren and the related type of forms based on the formation processes that includes the type of sediment cover and the morphology. We consider three major groups of karren: i those in which the dominant process (associated to dissolution is related to running water; ii those formed by the combined action of the runoff and of dissolution controlled by structural factors; iii those with a mostly biochemical genesis, resulting from the action of dissolution (due to the persistence of water in flattened surfaces and of the living organisms.
-
A new generation of ultra-dense optical I/O for silicon photonics
Wlodawski, Mitchell S.; Kopp, Victor I.; Park, Jongchul; Singer, Jonathan; Hubner, Eric E.; Neugroschl, Daniel; Chao, Norman; Genack, Azriel Z.
2014-03-01
In response to the optical packaging needs of a rapidly growing silicon photonics market, Chiral Photonics, Inc. (CPI) has developed a new generation of ultra-dense-channel, bi-directional, all-optical, input/output (I/O) couplers that bridge the data transport gap between standard optical fibers and photonic integrated circuits. These couplers, called Pitch Reducing Optical Fiber Arrays (PROFAs), provide a means to simultaneously match both the mode field and channel spacing (i.e. pitch) between an optical fiber array and a photonic integrated circuit (PIC). Both primary methods for optically interfacing with PICs, via vertical grating couplers (VGCs) and edge couplers, can be addressed with PROFAs. PROFAs bring the signal-carrying cores, either multimode or singlemode, of many optical fibers into close proximity within an all-glass device that can provide low loss coupling to on-chip components, including waveguides, gratings, detectors and emitters. Two-dimensional (2D) PROFAs offer more than an order of magnitude enhancement in channel density compared to conventional one-dimensional (1D) fiber arrays. PROFAs can also be used with low vertical profile solutions that simplify optoelectronic packaging while reducing PIC I/O real estate usage requirements. PROFA technology is based on a scalable production process for microforming glass preform assemblies as they are pulled through a small oven. An innovative fiber design, called the "vanishing core," enables tailoring the mode field along the length of the PROFA to meet the coupling needs of disparate waveguide technologies, such as fiber and onchip. Examples of single- and multi-channel couplers fabricated using this technology will be presented.
-
Decuyper, Mieke; De Fruyt, Filip; Buschman, Jos
2008-01-01
The validity of DSM-IV predictions [Widiger, T. A., Trull, T. J., Clarkin, J. F., Sanderson, C. J., & Costa, P. T., (2002). A description of the DSM-IV personality disorders with the five-factor model of personality. In Costa, P. T. & Widiger, T. A. (Eds.), Personality disorders and the five-factor model of personality (2nd ed.). Washington DC: American Psychological Association] concerning Antisocial Personality Disorder and the validity of the hypothesized associations between the Five-Factor Model and psychopathy were examined in 48 male forensic-psychiatric patients. Prevalence of psychopathy and comorbid personality pathology was also investigated, as well as the convergent validity of two Dutch personality disorder inventories. Patients provided self-descriptions on the NEO-PI-R [Costa, P. T., & McCrae, R. R., (1992b). Professional Manual: Revised NEO Personality Inventory (NEO-PI-R) and NEO Five-Factor-Inventory (NEO-FFI). Odessa, FL: Psychological Assessment Resources], and were administered the VKP [Duijsens, I. J., Haringsma, R., & EurelingsBontekoe, E. H. M., (1999). Handleiding VKP (Vragenlijst voor kenmerken van de persoonlijkheid). Gebaseerd op DSM-IV en ICD-10. Leiderdorp: Datec] and the ADP-IV [Schotte, C. K. W., & De Doncker, D. A. M., (1994). ADP-IV Questionnaire. Antwerp Belgium: University Hospital Antwerp] to assess personality pathology. Psychopathy was assessed using Hare's Psychopathy Checklist-Revised (PCL-R; [Hare, R. D., (1990). The Hare Psychopathy Checklist Revised Manual. Toronto: Multi-Health Systems]) based on a semi-structured interview and file records of psychiatric and psychological evaluations and criminal history. Results underscored the validity of the FFM Antisocial PD associations, but the hypothesized correlations between the FFM and Psychopathy were less supported. Results supported the convergent validity of the ADP-IV and the VKP, both at the dimensional and categorical level. Around 55% met the diagnostic threshold of
-
Results from the BRACE 1.5 study: Climate change impacts of 1.5 C and 2 C warming
O'Neill, B. C.; Anderson, B.; Monaghan, A. J.; Ren, X.; Sanderson, B.; Tebaldi, C.
2017-12-01
In 2015, 195 countries negotiated the Paris Agreement on climate change, which set long-term goals of limiting global mean warming to well below 2 C and possibly 1.5 C. This event stimulated substantial scientific interest in climate outcomes and impacts on society associated with those levels of warming. Recently, the first set of global climate model simulations explicitly designed to meet those targets were undertaken with the Community Earth System Model (CESM) for use by the research community (Sanderson et al, accepted). The BRACE 1.5 project models societal impacts from these climate outcomes, combined with assumptions about future socioeconomic conditions according to the Shared Socioeconomic Pathways. These analyses build on a recently completed study of the Benefits of Reduced Anthropogenic Climate changE (BRACE), published as a set of 20 papers in Climatic Change, which examined the difference in impacts between two higher scenarios resulting in about 2.5 C and 3.7 C warming by late this century. BRACE 1.5 consists of a set of six papers to be submitted to a special collection in Environmental Research Letters that takes a similar approach but focuses on impacts at 1.5 and 2 C warming. We ask whether impacts differ substantially between the two climate scenarios, accounting for uncertainty in climate outcomes through the use of initial condition ensembles of CESM simulations, and in societal conditions by using alternative SSP-based development pathways. Impact assessment focuses on the health and agricultural sectors; modeling approaches include the use of a global mutli-region CGE model for economic analysis, both a process-based and an empirical crop model, a model of spatial population change, a model of climatic suitability for the aedes aegypti mosquito, and an epidemiological model of heat-related mortality. A methodological analysis also evaluates the use of climate model emulation techniques for providing climate information sufficient to
-
Measuring the Speed of Aging across Population Subgroups
2014-01-01
People in different subgroups age at different rates. Surveys containing biomarkers can be used to assess these subgroup differences. We illustrate this using hand-grip strength to produce an easily interpretable, physical-based measure that allows us to compare characteristic-based ages across educational subgroups in the United States. Hand-grip strength has been shown to be a good predictor of future mortality and morbidity, and therefore a useful indicator of population aging. Data from the Health and Retirement Survey (HRS) were used. Two education subgroups were distinguished, those with less than a high school diploma and those with more education. Regressions on hand-grip strength were run for each sex and race using age and education, their interactions and other covariates as independent variables. Ages of identical mean hand-grip strength across education groups were compared for people in the age range 60 to 80. The hand-grip strength of 65 year old white males with less education was the equivalent to that of 69.6 (68.2, 70.9) year old white men with more education, indicating that the more educated men had aged more slowly. This is a constant characteristic age, as defined in the Sanderson and Scherbov article “The characteristics approach to the measurement of population aging” published 2013 in Population and Development Review. Sixty-five year old white females with less education had the same average hand-grip strength as 69.4 (68.2, 70.7) year old white women with more education. African-American women at ages 60 and 65 with more education also aged more slowly than their less educated counterparts. African American men with more education aged at about the same rate as those with less education. This paper expands the toolkit of those interested in population aging by showing how survey data can be used to measure the differential extent of aging across subpopulations. PMID:24806337
-
Suzuki, Akira; Nakano, Masayuki; Yoshizaki, Keigo; Yasunaga, Atsushi; Haruyama, Naoto; Takahashi, Ichiro
2017-05-01
The aim is to survey primary and permanent dental anomalies: hypodontia, microdontia, a supernumerary tooth, and fused teeth in patients with cleft lip and/or palate. Retrospective longitudinal study Subjects : The subjects were selected from all 1724 patients with cleft lip and/or palate who were registered at the orthodontic clinic of Kyushu University Hospital, Fukuoka, Japan, from 1970 to 2009. Finally, 994 subjects were evaluated for primary dentition, 1352 for permanent dentition, and 871 for the longitudinal changes from primary to permanent dentition. The prevalence of dental anomalies was compared for each tooth type, among various cleft types, between males and females, and between the alveolar cleft area and the noncleft area. The prevalence of hypodontia was 16.2% for primary dentition and 52.7% for permanent dentition in the subjects with cleft lip and/or palate. Hypodontia increased with the severity of the cleft type. Multiple hypodontia was found more frequently in the subjects with bilateral cleft lip and palate and the subjects with unilateral cleft lip and palate. Microformed lateral incisors were found in 22.7% of permanent lateral incisors but not in primary dentition. Supernumerary teeth were found in 17.7% of the subjects with cleft lip and/or palate for primary maxillary dentition and in 5.7% for permanent maxillary dentition. The prevalence of hypodontia was greater in permanent dentition than in primary dentition; although, it was not much different between males and females or between the right and left sides. The prevalence of dental anomalies was significantly different among four groups by cleft type: cleft lip, cleft lip and alveolus, cleft lip and palate, and cleft palate.
-
Applicability of Unmanned Aerial Vehicles in Research on Aeolian Processes
Algimantas, Česnulevičius; Artūras, Bautrėnas; Linas, Bevainis; Donatas, Ovodas; Kęstutis, Papšys
2018-02-01
Surface dynamics and instabilities are characteristic of aeolian formation. The method of surface comparison is regarded as the most appropriate one for evaluation of the intensity of aeolian processes and the amount of transported sand. The data for surface comparison can be collected by topographic survey measurements and using unmanned aerial vehicles. Time cost for relief microform fixation and measurement executing topographic survey are very high. The method of unmanned aircraft aerial photographs fixation also encounters difficulties because there are no stable clear objects and contours that enable to link aerial photographs, to determine the boundaries of captured territory and to ensure the accuracy of surface measurements. Creation of stationary anchor points is irrational due to intense sand accumulation and deflation in different climate seasons. In September 2015 and in April 2016 the combined methodology was applied for evaluation of intensity of aeolian processes in the Curonian Spit. Temporary signs (marks) were installed on the surface, coordinates of the marks were fixed using GPS and then flight of unmanned aircraft was conducted. The fixed coordinates of marks ensure the accuracy of measuring aerial imagery and the ability to calculate the possible corrections. This method was used to track and measure very small (micro-rank) relief forms (5-10 cm height and 10-20 cm length). Using this method morphometric indicators of micro-terraces caused by sand dunes pressure to gytia layer were measured in a non-contact way. An additional advantage of the method is the ability to accurately link the repeated measurements. The comparison of 3D terrain models showed sand deflation and accumulation areas and quantitative changes in the terrain very clearly.
-
Directory of Open Access Journals (Sweden)
BERNABÉ SANTELICES
2002-09-01
Full Text Available Previous studies have found that the number of species conforming a bank of microscopic forms in tide pools in central Chile accounted only for half the number of species present in the macroscopic vegetation around the pools. An elemental condition for survival in these banks is the ability of microscopic forms to tolerate darkness or very low irradiances for extended periods. To test this ability, spores of 17 green, brown and red algal species, present and absent from the bank, were incubated at different combinations of irradiances and day lengths. Propagules of 47 % of the species tested (eight species germinated in total darkness while the propagules of the other nine species germinated under conditions of very low irradiance (2-10 µmol m-2 s-1. In most species, microforms showed a higher tolerance to darkness than the propagules. Some survived for over a year and one species (Gelidium lingulatum could live under complete darkness for 500 days. The ability to survive in total darkness did not relate to presence or absence of a species in the banks of microscopic forms previously studied, to phylogenetic relatedness, life history style, propagule size, morphology of microscopic forms or to successional status (fugitive versus late successional. Thus, tolerance to darkness appears to be common to propagules and microscopic stages of most benthic algae. The growth patterns exhibited by the microforms of Lessonia nigrescens, Chaetomorpha firma and Glossophora kunthii suggest high irradiances on these recruits might determine the shallower limits of distribution of these speciesEstudios previos han encontrado que el número de especies formando un banco de formas microscópicas en pozas de mareas de Chile central incluyó sólo la mitad del número de especies presentes en la vegetación macroscópica en las cercanías de las pozas intermareales. Una primera condición para sobrevivir en estos bancos radica en la capacidad de las formas
-
Swindles, Graeme T; Reczuga, Monika; Lamentowicz, Mariusz; Raby, Cassandra L; Turner, T Edward; Charman, Dan J; Gallego-Sala, Angela; Valderrama, Elvis; Williams, Christopher; Draper, Frederick; Honorio Coronado, Euridice N; Roucoux, Katherine H; Baker, Tim; Mullan, Donal J
2014-08-01
Tropical peatlands represent globally important carbon sinks with a unique biodiversity and are currently threatened by climate change and human activities. It is now imperative that proxy methods are developed to understand the ecohydrological dynamics of these systems and for testing peatland development models. Testate amoebae have been used as environmental indicators in ecological and palaeoecological studies of peatlands, primarily in ombrotrophic Sphagnum-dominated peatlands in the mid- and high-latitudes. We present the first ecological analysis of testate amoebae in a tropical peatland, a nutrient-poor domed bog in western (Peruvian) Amazonia. Litter samples were collected from different hydrological microforms (hummock to pool) along a transect from the edge to the interior of the peatland. We recorded 47 taxa from 21 genera. The most common taxa are Cryptodifflugia oviformis, Euglypha rotunda type, Phryganella acropodia, Pseudodifflugia fulva type and Trinema lineare. One species found only in the southern hemisphere, Argynnia spicata, is present. Arcella spp., Centropyxis aculeata and Lesqueresia spiralis are indicators of pools containing standing water. Canonical correspondence analysis and non-metric multidimensional scaling illustrate that water table depth is a significant control on the distribution of testate amoebae, similar to the results from mid- and high-latitude peatlands. A transfer function model for water table based on weighted averaging partial least-squares (WAPLS) regression is presented and performs well under cross-validation (r(2)(apparent)= 0.76, RMSE = 4.29; r(2)(jack)= 0.68, RMSEP =5.18). The transfer function was applied to a 1-m peat core, and sample-specific reconstruction errors were generated using bootstrapping. The reconstruction generally suggests near-surface water tables over the last 3,000 years, with a shift to drier conditions at c. cal. 1218-1273 AD.
-
A simple objective method for determining a dynamic journal collection.
Bastille, J D; Mankin, C J
1980-10-01
In order to determine the content of a journal collection responsive to both user needs and space and dollar constraints, quantitative measures of the use of a 647-title collection have been related to space and cost requirements to develop objective criteria for a dynamic collection for the Treadwell Library at the Massachusetts General Hospital, a large medical research center. Data were collected for one calendar year (1977) and stored with the elements for each title's profile in a computerized file. To account for the effect of the bulk of the journal runs on the number of uses, raw use data have been adjusted using linear shelf space required for each title to produce a factor called density of use. Titles have been ranked by raw use and by density of use with space and cost requirements for each. Data have also been analyzed for five special categories of use. Given automated means of collecting and storing data, use measures should be collected continuously. Using raw use frequency ranking to relate use to space and costs seems sensible since a decision point cutoff can be chosen in terms of the potential interlibrary loans generated. But it places new titles at risk while protecting titles with long, little used runs. Basing decisions on density of use frequency ranking seems to produce a larger yield of titles with fewer potential interlibrary loans and to identify titles with overlong runs which may be pruned or converted to microform. The method developed is simple and practical. Its design will be improved to apply to data collected in 1980 for a continuous study of journal use. The problem addressed is essentially one of inventory control. Viewed as such it makes good financial sense to measure use as part of the routine operation of the library to provide information for effective management decisions.
-
1980-10-01
ClW Q F . ISO C . ( 0 CX 2 L - 4 . LL; 2j LL C : m (r r I 4Ck) CD ; .J c -w. (.4.L Wa..) ~ ~ ~ L C-) -) ~- . C F- 0 24 2i > LL. C..> C L. u0 a, t...chart and the International Standards Organisation ( ISO ) ’mire’ test character V1 (see also References 58, 59). 171 6.2.3 Microfilm Density...21440 £ 27000 Total p.a. £45900 £51460 For the choson conditions and cost assumptions, it appears that the internal printing operation would be the
-
Fire and Microtopography in Peatlands: Feedbacks and Carbon Dynamics
Benscoter, B.; Turetsky, M. R.
2011-12-01
Fire is the dominant natural disturbance in peatland ecosystems. Over the past decade, peat fires have emerged as an important issue for global climate change, human health, and economic loss, largely due to the extreme peat fire events in Indonesia and Russia that severely impacted metropolitan areas and social infrastructure. However, the impact and importance of fire in peatland ecosystems are more far-reaching. Combustion of vegetation and soil organic matter releases an average of 2.2 kg C m-2 to the atmosphere, primarily as CO2, as well as a number of potentially harmful emissions such as fine particulate matter and mercury. Additionally, while peatlands are generally considered to be net sinks of atmospheric carbon, the removal of living vegetation by combustion halts primary production following fire resulting in a net loss of ecosystem carbon to the atmosphere for several years. The recovery of carbon sink function is linked to plant community succession and development, which can vary based on combustion severity and the resulting post-fire microhabitat conditions. Microtopography has a strong influence on fire behavior and combustion severity during peatland wildfires. In boreal continental peatlands, combustion severity is typically greatest in low-lying hollows while raised hummocks are often lightly burned or unburned. The cross-scale influence of microtopography on landscape fire behavior is due to differences in plant community composition between microforms. The physiological and ecohydrological differences among plant communities result in spatial patterns in fuel availability and condition, influencing the spread, severity, and type of combustion over local to landscape scales. In addition to heterogeneous combustion loss of soil carbon, this differential fire behavior creates variability in post-fire microhabitat conditions, resulting in differences in post-fire vegetation succession and carbon exchange trajectories. These immediate and legacy
-
Harder, S. R.; Roulet, N. T.; Strachan, I. B.; Crill, P. M.; Persson, A.; Pelletier, L.; Watt, C.
2014-12-01
Various microforms, created by spatial differential thawing of permafrost, make up the subarctic heterogeneous Stordalen peatland complex (68°22'N, 19°03'E), near Abisko, Sweden. This results in significantly different peatland vegetation communities across short distances, as well as differences in wetness, temperature and peat substrates. We have been measuring the spatially integrated CO2, heat and water vapour fluxes from this peatland complex using eddy covariance and the CO2 exchange from specific plant communities within the EC tower footprint since spring 2008. With this data we are examining if it is possible to derive the spatially integrated ecosystem-wide fluxes from community-level simple light use efficiency (LUE) and ecosystem respiration (ER) models. These models have been developed using several years of continuous autochamber flux measurements for the three major plant functional types (PFTs) as well as knowledge of the spatial variability of the vegetation, water table and active layer depths. LIDAR was used to produce a 1 m resolution digital evaluation model of the complex and the spatial distribution of PFTs was obtained from concurrent high-resolution digital colour air photography trained from vegetation surveys. Continuous water table depths have been measured for four years at over 40 locations in the complex, and peat temperatures and active layer depths are surveyed every 10 days at more than 100 locations. The EC footprint is calculated for every half-hour and the PFT based models are run with the corresponding environmental variables weighted for the PFTs within the EC footprint. Our results show that the Sphagnum, palsa, and sedge PFTs have distinctly different LUE models, and that the tower fluxes are dominated by a blend of the Sphagnum and palsa PFTs. We also see a distinctly different energy partitioning between the fetches containing intact palsa and those with thawed palsa: the evaporative efficiency is higher and the Bowen
-
Reusch, D. B.
2017-12-01
Melting on the surface of the Greenland ice sheet has been changing dramatically as global air temperatures have increased in recent decades, including melt extent often exceeding the 1981-2010 median through much of the melt season and the onset of intermittent melt moving to earlier in the year. To evaluate potential future change, we investigate surface melting characteristics under both "low" (limited to 1.5 °C) and "high" (RCP 8.5) warming scenarios including analysis of differences in scenario outcomes. Climatologies of melt-relevant variables are developed from two publicly available ensembles of CESM1-CAM5-BGC GCM runs: the 30-member Large Ensemble (CESM LE; Kay et al. 2015) for historical calibration and the RCP 8.5 scenario and the 11-member Low Warming ensemble (CESM LW; Sanderson et al. 2017) for the 1.5 °C scenario. For higher spatial resolution (15 km) and improved polar-centric model physics, we also apply the regional forecast model Polar WRF to decadal subsets (1996-2005; 2071-80) using GCM data archived at sub-daily resolution for boundary conditions. Models were skill-tested against ERA-Interim Reanalysis (ERAI) and AWS observations. For example, CESM LE tends to overpredict both maximum (above-freezing) and minimum daily average surface temperatures compared to observations from the GC-Net Swiss Camp AWS. Ensembles of members differing only by initial conditions allow us to also estimate intramodel uncertainty. Historical (1981-2000) CESM LE spatially averaged July temperatures are 2 +/- 0.2 °C cooler than ERAI while local anomalies in individual members reach up to +/- 2 °C. As expected, Greenland does not escape future (2081-2100) warming (and expectations of more widespread surface melting) even in the LW scenario, but positive changes versus ERAI are mostly coastal (2-3 °C) with the interior showing only minor change (+/- 1 °C). In contrast, under RCP 8.5, the entire ice sheet has warmed by 2-6 °C, or a median increase of 5 °C versus
-
Implementation and utilization of genetic testing in personalized medicine
Directory of Open Access Journals (Sweden)
Abul-Husn NS
2014-08-01
Full Text Available Noura S Abul-Husn,1,* Aniwaa Owusu Obeng,2,3,* Saskia C Sanderson,1 Omri Gottesman,2 Stuart A Scott11Department of Genetics and Genomic Sciences, 2The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, 3Department of Pharmacy, Mount Sinai Hospital, New York, NY, USA*These authors contributed equally to this manuscriptAbstract: Clinical genetic testing began over 30 years ago with the availability of mutation detection for sickle cell disease diagnosis. Since then, the field has dramatically transformed to include gene sequencing, high-throughput targeted genotyping, prenatal mutation detection, preimplantation genetic diagnosis, population-based carrier screening, and now genome-wide analyses using microarrays and next-generation sequencing. Despite these significant advances in molecular technologies and testing capabilities, clinical genetics laboratories historically have been centered on mutation detection for Mendelian disorders. However, the ongoing identification of deoxyribonucleic acid (DNA sequence variants associated with common diseases prompted the availability of testing for personal disease risk estimation, and created commercial opportunities for direct-to-consumer genetic testing companies that assay these variants. This germline genetic risk, in conjunction with other clinical, family, and demographic variables, are the key components of the personalized medicine paradigm, which aims to apply personal genomic and other relevant data into a patient's clinical assessment to more precisely guide medical management. However, genetic testing for disease risk estimation is an ongoing topic of debate, largely due to inconsistencies in the results, concerns over clinical validity and utility, and the variable mode of delivery when returning genetic results to patients in the absence of traditional counseling. A related class of genetic testing with analogous issues of clinical utility and
-
Otsubo, M.; Hardebeck, J.; Miyakawa, A.; Yamaguchi, A.; Kimura, G.
2017-12-01
Fluid-rock interactions along seismogenic faults are of great importance to understand fault mechanics. The fluid loss by the formation of mode I cracks (tension cracks) increases the fault strength and creates drainage asperities along the plate interface (Sibson, 2013, Tectonophysics). The Nobeoka Thrust, in southwestern Japan, is an on-land example of an ancient megasplay fault and provides an excellent record of deformation and fluid flow at seismogenic depths of a subduction zone (Kondo et al., 2005, Tectonics). We focus on (1) Pore fluid pressure loss, (2) Amount of fault strength recovery, and (3) Fluid circulation by the formation of mode I cracks in the post-seismic period around the fault zone of the Nobeoka Thrust. Many quartz veins that filled mode I crack at the coastal outcrops suggest a normal faulting stress regime after faulting of the Nobeoka Thrust (Otsubo et al., 2016, Island Arc). We estimated the decrease of the pore fluid pressure by the formation of the mode I cracks around the Nobeoka Thrust in the post-seismic period. When the pore fluid pressure exceeds σ3, veins filling mode I cracks are constructed (Jolly and Sanderson, 1997, Jour. Struct. Geol.). We call the pore fluid pressure that exceeds σ3 "pore fluid over pressure". The differential stress in the post-seismic period and the driving pore fluid pressure ratio P* (P* = (Pf - σ3) / (σ1 - σ3), Pf: pore fluid pressure) are parameters to estimate the pore fluid over pressure. In the case of the Nobeoka Thrust (P* = 0.4, Otsubo et al., 2016, Island Arc), the pore fluid over pressure is up to 20 MPa (assuming tensile strength = 10 MPa). 20 MPa is equivalent to fluid pressure around the Nobeoka Thrust (depth = 10 km, density = 2.7 kg/m3). When the pore fluid pressure decreases by 4%, the normalized pore pressure ratio λ* (λ* = (Pf - Ph) / (Pl - Ph), Pl: lithostatic pressure; Ph: hydrostatic pressure) changes from 0.95 to 0.86. In the case of the Nobeoka Thrust, the fault strength can
-
CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)
Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica
2015-04-01
South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum
-
Directory of Open Access Journals (Sweden)
Dulal C. Ghosh
2004-09-01
Full Text Available The formation of the F3B–NH3 supermolecule by chemical interaction of its fragment parts, BF3 and NH3, and the dynamics of internal rotation about the ‘B–N’ bond have been studied in terms of parameters provided by the molecular orbital and density functional theories. It is found that the pairs of frontier orbitals of the interacting fragments have matching symmetry and are involved in the charge transfer interaction. The donation process stems from the HOMO of the donor into the LUMO of the acceptor and simultaneously, back donation stems from the HOMO of acceptor into the LUMO of the donor. The density functional computation of chemical activation in the donor and acceptor fragments, associated with the physical process of structural reorganization just prior to the event of chemical reaction, indicates that BF3 becomes more acidic and NH3 becomes more basic, compared to their separate equilibrium states. Theoretically it is observed that the chemical reaction event of the formation of the supermolecule from its fragment parts is in accordance with the chemical potential equalization principle of the density functional theory and the electronegativity equalization principle of Sanderson. The energetics of the chemical reaction, the magnitude of the net charge transfer and the energy of the newly formed bond are quite consistent, both internally and with the principle of maximum hardness, PMH. The dynamics of the internal rotation of one part with respect to the other part of the supermolecule about the ‘B–N’ bond mimics the pattern of the conformational isomerism of the isostructural ethane molecule. It is also observed that the dynamics and evolution of molecular conformations as a function of dihedral angles is also in accordance with the principle of maximum hardness, PMH. Quite consistent with spectroscopic predictions, the height of the molecule
-
Institute of Scientific and Technical Information of China (English)
邓露芳; 范学珊; 王加启
2012-01-01
试验根据豆粕、菜粕和棉粕作为植物性蛋白饲料的营养特性,选择中性蛋白酶活较高的细菌和真菌作为发酵豆粕、菜粕和棉粕的菌种以改善豆粕、菜粕和棉粕的蛋白质品质.通过细菌和真菌的两两组合生长试验,分别筛选出适合发酵豆粕、菜粕和棉粕的最佳复合菌各一组.试验结果表明,发酵豆粕、菜粕和棉粕的最佳菌株组合为BS-2和Ao、BS-natto和Ao、BS-natto和Ao.%Based on nutrition characters on soybean meal, rapeseed meal and cotton seed meal, high neutral enzyme production of bacteria and fungus were chose to inoculate in them to improve their protein quality as animal feed. Compounded one bacterium strain and one fungus strain cultured together, chose the best group to ferment the soybean meal, rapeseed meal and cotton seed meal. The results showed the best groups were BS-2 and Ao for soybean meal, BS-natto and Ao for rapeseed meal, and BS-natto and Ao for cotton seed meal.
-
A new experimental system for study on adaptive mutations
Institute of Scientific and Technical Information of China (English)
Lü; Zhong; (
2001-01-01
［1］Luria, S. E., Delbrück, M., Mutation of bacteria from virus sensitivity to virus resistance, Genetics, 1943, 28: 491.［2］Lederberg, J., Lederberg, E. M., Replica plating and indirect selection of bacteria mutants, J. Bacteriol., 1952, 63: 399.［3］Carins, J., Overbaugh, J., Miller, S., The origin of mutants, Nature, 1988, 355: 142.［4］Foster, P. L., Adaptive mutation: the uses of adversity, Annu. Rev. Microbiol., 1993, 47: 467.［5］Hall, B. G., Adaptive mutagenesis: a process that generates almost exclusively beneficient mutations, Genetica, 1998, 102/103: 109.［6］Kasak, L., Horak, R., Kivisaar, M., Promotor-creating mutations in Psuedmonas putida: A model system for the study of mutation in starving bacteria, PNAS, 1997, 94: 3134.［7］Steele, D. F., Jinks-Robertson, An examination of adaptive reversion in Saccharomyces cerevisiae, Genetics, 1992, 132: 9.［8］Davis, R. W., Botstein, Roth, J. R., Advanced Bacterial Genetics--A Manual for Genetic Engineering, New York: Cold Spring Harbor Laboratory Press, 1980, 13.［9］Miller, J. H., Experiments in Molecular Genetics, New York: Cold Spring Harbor Laboratory Press, 1972, 352.［10］ Lea, D. E., Coulson, C. A., The distribution of the numbers of mutants in bacterial populations, J. Genetics, 1949, 49: 264.［11］ Hughes, K. T., Roth, J. R., Transitory cis complementation: a method for provided transposition function to defective transposons, Genetics, 1988, 119: 9.［12］ Sanderson, K. E., Roth J., Linkage map of Salmonella typhimurium, Microbiol. Rev., 1988, 52: 485.［13］ He, B., Shiau, A., Choi, K. Y., Genes of the E. coli pur region are negatively controlled by a repressor-operator interaction, J. Bacteriol., 1990, 172: 4555.［14］ Liu, B., Huang, Y., Wang, A. Q., Regulation of purine biosynthetic genes expression in Salmonella typhimurium (IV)--Oc mutation site of purG and its function analysis, Science in China, Ser. C, 1997, 40(3): 238.［15］ Tang, H., Qin, J. C., Wang, A. Q
-
Human-induced environmental degradation during Anthropocene in Turkey
Efe, Recep; Curebal, Isa; Soykan, Abdullah; Sönmez, Suleyman
2015-04-01
affected by humans (Sanderson et al., 2002; Braje&Erlandson, 2014). The area left in its natural state corresponds to only 15%. Due to population increase, agricultural areas shrinked, forests were destroyed, and pastures declined in size. More chemical fertilizers and agricultural pesticides were used in order to obtain more products. A greater number of machines were employed in agriculture, which led to a rise in the number of products. The human pressure on the environment in Anatolia dates back to thousands of years. Nomadic peoples on these lands have settled in the last 200 years due to settlement policies (Cürebal et al., 2015). This process saw the establishment of villages in higher and inclined areas as a result of the effects of the nomadic culture of Turkomans and other people in Anatolia. Forests in the inclined areas around these villages were destroyed and turned into agricultural areas. Machines, fertilizers, and pesticides were utilized in agricultural activities in order to produce more crops. This transformation led to an increased erosion effect, deterioration of soil, agricultural and environmental pollution (Chin et al., 2013; Hoang et al., 2014; Matteo et al., 2014). The change caused by industrialization gained ground in the 1950s in Turkey. In particular, migration from rural areas to cities gaining pace after the World War II brought about an increased human pressure in and around big cities. Areas around the cities became centers of attraction for many people. Plains around settlement areas were opened to settlement, and most industrial facilities were established there. As a consequence, first class agricultural areas were lost. Settlements and industrial areas generated large amounts of solid and liquid waste. Uncontrolled discharge of liquid waste and intensely stored solid waste caused the physical and chemical pollution of rivers, lakes, and seas to increase in Turkey and other parts of the world (Andersson et al., 2006; Steffen et al
-
Manning, Frances; Lip Khoon, Kho; Hill, Tim; Arn Teh, Yit
2017-04-01
Oil palm plantations have been expanding rapidly on tropical peat soils in the last 20 years, with 50 % of SE Asian peatlands now managed as industrial or small-holder plantations, up from 11% in 1990. Tropical peat soils are an important carbon (C) store, containing an estimated 17 % of total peatland C. There are large uncertainties as to the soil C dynamics in oil palm plantations on peat due to a shortage of available data. It is therefore essential to understand the soil C cycle in order to promote effective management strategies that optimise yields, whilst maintaining the high C storage capacity of the soil. Here we present CO2 and CH4 fluxes from two oil palm plantations in Sarawak, Malaysia on peat soils. Data were collected from different surface microforms within each plantation that experienced different surface management practices. These included the area next to the palm, in bare soil harvest paths, beneath frond piles, underneath cover crops, from the surface of drains, and from palm stems. Data were collected continuously over one year and analysed with different environmental variables, including soil temperature, WTD, O2, soil moisture and weather data in order to best determine the constraints on the dataset. Total soil respiration (Rtot) varied between 0.09 and 1.59 g C m-2 hr-1. The largest fluxes (0.59 - 1.59 g C m-2 hr-1) were measured next to the palms. Larger CO2 fluxes were observed beneath the cover crops than in the bare soil. This trend was attributed to priming effects from the input of fresh plant litter and exudates. Peat soil type was shown to have significantly different fluxes. The different plantations also had different environmental drivers best explaining the variation in Rtot - with soil moisture being the most significant variable on Sabaju series soil and soil temperature being the most significant environmental variable in the plantation with the Teraja series soil. Rtot was shown to reduce significantly with increasing
-
Weathering landforms exposure and erosion phases in Pedriza de Manzanares (Spanish Central Range)
García-Rodríguez, M.; Centeno Carrillo, J. D.; Alvarez de Buergo, M.
2012-04-01
The phases of erosion can be reconstructed measuring the position and dimensions of exposed granite underground weathering landforms. We afford a first approach of this kind of "erosion history" in the area of Pedriza de Manzanares. Pedriza de Manzanares is the main part of the Natural Park of High Manzanares River Basin. The area is part also of the Late Paleozoic granites of the Spanish Central Range, intruded during the Variscan orogeny, and uplifted to its present position during Alpine orogeny. The granite shows a complex fracture pattern (related to Variscan and Alpine processes) that defines a landscape with alternance of regolith-connected-depressions and fresh granite outcrops with abundant bornhards and boulders. Pedriza (as most people call it) is a well known area for its granite landforms which attract tourism, educators and rock climbers. In this area, the contrasting hydrological behaviour of fresh and weathered granite, especially in fractures areas, produces small aquifers with a high recharge from adjacent impermeable surfaces. These conditions have been studied in relation to the soil water availability (for both human and ecosystems), and in relation to the geomorphic edaphic processes (taffoni, flared slopes, etc.). In previous works (García et al., 2008, Centeno et al., 2010) a conceptual model using MS-Excel was devised which provided the basis by which were defined the relevant variables and their interconnections (landforms, climate, hydrogeology). From the standpoint of soils water (and the related weathering processes or ecosystem characteristics), this is especially important in semi-arid and arid climates, as has been appreciated by practising farmers for many years, for the contrast in productive potential in stark between the regolithic and rocky areas. At the same time, granite weathering is enhanced by the persistent presence of water in the regolith and, as a consequence, many microforms are initiated or evolve under the regolith
-
Directory of Open Access Journals (Sweden)
Kurt Blythe
2008-03-01
articles appearing in 90 journals. However, only six journals were responsible for publishing 60% of the articles on the results list. Based on the categorization into topics or types,five article types – “general essays,” articles on “instruction for searching online catalogs and databases,” “articles on course‐ or assignment‐related instruction,” “programmatic and management issues,”and “specific institution instruction” –accounted for 54% of the total articles; eleven other topics are represented in the remaining articles. Only 24.5% of the articles could be considered “research‐based.” While nine types of research methods were used, 62.3% of the research‐based articles relied on surveys or questionnaires. However, taking into account what could be an expected decline in interest for studying instruction for microforms, and an increased interest in studying instruction for the Internet, the types of articles published each year between 1971 and 2002 remained generally static.Conclusion – The authors conclude that, unsurprisingly, a select few journals are responsible for publishing the majority of articles on instruction in academic libraries, and note that these journals are “closely associated with academic librarianship and instruction” (85. The authors’ findings concerning the types of articles published over the course of the date range examined, although interesting, are equally unsurprising. What is surprising and alarming, is that only a quarter of all articles published are research-based. Furthermore, those articles that were found to be research-based did not often employ sophisticated research methods, preferring for example, the use of descriptive statistics over inferential statistics. Ideally, this article will spur the development and publication of more, and more rigorous, research‐based scholarship in addition to pointing authors both to the journals most likely to publish their research and to the topics