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Sample records for kaj uchilishnata populacija

  1. Flow Characteristics over a Gravel Bedform: Kaj River Case Study

    NASA Astrophysics Data System (ADS)

    Maddahi, Mohammad Reza; Afzalimehr, Hossein; Rowinski, Paweł M.

    2016-10-01

    The present study deals with the turbulence structure in order to better understand the interaction of bedform and flow characteristics in a gravel-bed river. Data measured above a bedform is used to analyze the importance of coherent structures in turbulent transfer. The Reynolds stress and turbulence intensity in stream-wise direction illustrate significant difference along the bedform, showing a three-layer distribution at the crest and a convex one at the downstream of bedform. Quadrant analysis technique is used to picture momentum exchange above the considered bedform and to find the dominant event in bursting process of the gravel bedform. Quadrant analysis demonstrates that the mechanisms of bedforms generation in sand and gravel-bed rivers are similar and sweep is the dominant event in both rivers.

  2. Kaj Ulrik Linderstrøm-Lang (1896-1959).

    PubMed Central

    Schellman, J. A.; Schellman, C. G.

    1997-01-01

    The Carlsberg Laboratory in Copenhagen has had a long tradition of outstanding science. At the time covered by this discussion, Kjeldahl, Sørensen, and Linderstrøm-Lang had been consecutive directors of the Chemical Laboratory for 83 years. Lang's inspired leadership began in the 1930s with a number of innovations (study of metabolism in single cells, titrations in non-aqueous solvents, relation of proteolysis to structure) but it was not until the early 1950s that Denmark had sufficiently recovered from the war for the laboratory to enter world science again. During World War II, Lang had been active in the Danish resistance movement. After the war, a number of major advances were being made that would revolutionize the field of protein chemistry (Pauling and Corey's H-bonded structures, Sanger's sequencing techniques, chromatography, Watson and Crick structures, modern instrumentation). The time for the new field of the physical biochemistry of proteins had arrived. Lang, with his broad experience, adventurous spirit, and genius for innovation, created an environment that was ideal for the convergence of these disconnected advances into a uniform science. The emphasis was to be on quantitative measurements on proteins in solution with interpretations based on molecular structures. During an all-too-brief period of time, Lang's laboratory attracted a large fraction of those who were destined to be the leaders of the next generation of protein chemists. At this time, the Carlsberg Laboratory was probably the most scientifically exciting environment for a protein chemist. The methods developed at that time-hydrogen exchange, limited proteolysis, optical rotatory dispersion, volume changes accompanying protein reactions, automatic titrations-are still all in common use and many of the visitors to the laboratory in that period and their students are still playing major roles in protein research. Lang's other qualities should not be ignored. He was not only a great scientist but also a musician, raconteur, artist, and an exceptionally warm and compassionate human being. PMID:9144781

  3. Deformation of Anatolian Plate: Constraints form GPS and Geological Data Mehmet Kokum and Kaj Johnson

    NASA Astrophysics Data System (ADS)

    Kokum, M.; Johnson, K. M.

    2011-12-01

    We have combine GPS-derived velocities and geological slip rates to build kinematic block models of the Anatolian Plate and surrounding regions relative. We determine long-term velocities of the blocks in this region and slip rates on major faults. We have adopted fourteen tectonic blocks: Anatolian, Eurasia, Nubian, Arabian, Aegean, Black Sea, Central Iran Block, Caucasus, Northern Greece, Marmara, Southwest Anatolian, Central Greece, Sinai and Southeast Aegean. Initial results show that inversions with GPS data alone give slip rates that are somewhat higher than geological slip rates on North Anatolian Fault zone. Our model suggests that Anatolian plate has anticlockwise movement and the rate of the movement increases in the direction of Hellenic arc that consistent with previous results. The North Anatolian Fault has a good paleoseismic earthquake record as and we will examine the influence of postseismic transients from past earthquakes, including the well-known sequence of 20th century earthquakes, on estimates of block motions and fault slip rates.

  4. Content and Language Integrated Learning: Teachers' and Teacher Educators' Experiences of English Medium Teaching. Publication No. 4.

    ERIC Educational Resources Information Center

    Sjoholm, Kaj, Ed.; Bjorklund, Mikaela, Ed.

    The publication on the integration of content area and second language instruction, focusing on the situation in Finland, consists of nine essays and a bibliography. The essays include: "Education in a Second or Foreign Language. An Overview" (Kaj Sjoholm); "Foreign Language Content Teaching in Teacher Education at Abo Akademi…

  5. US Army Aviation Engineering Flight Activity (USAAEFA) Report Bibliography 1961-1981

    DTIC Science & Technology

    1982-06-01

    W. Griffith NAJ C. Mittag A. Wlnn LTC W. Crlfflth HAJ C. Nittag J. Johnaon G. Bandar R. HcClallan NAJ J. Burden CPT H. Laraan C. Yaaakam A...Evaluation Model 2)4A Helicopter« with Fib*rf|Uae Rotor lladee R. Buckanln NAJ R. Robblne HAJ J . Benaon CPT R. Vincent A. Wlnn HAJ C. Mittag ...CW4 J. Bishop J. Negate J . Nlernenn R. Salth CPT W. Norton MAJ F, Doten KAJ C. Mittag HAJ R. Ward C. Yamakawa MAJ R. Terr C. Yamakawa

  6. Aircraft Maintenance Effectiveness Simulation (AMES) Model.

    DTIC Science & Technology

    1980-02-01

    80.8 1~2 At ’U........... M. 4.,M7 ’ * ,kAJ1’#-W;4&.- 4 5 * -44 !n 1 4 4 .. ~ vyz *~>A& r~pK~~ r ~yt~v~z4q AWIM(TRIS RDAA TAEWX 4 tA4k Unclassified...RRS .... ............. .. 32 4 Example of Maintenance Manhour Summary ... ............. . 34 5 Examples of Additional Status Reports... 5 Remove/Replace (RR) Jobs ...... ................. 99 A-6 Troubleshooting (TS) Jobs ...... .................. 101 A-7 No Defect (ND) Jobs

  7. A new model for the granite-pegmatite genetic relationships in the Kaluan-Azubai-Qiongkuer pegmatite-related ore fields, the Chinese Altay

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Zhang, Hui; Ma, Zhan-Long; Tang, Yong; Lv, Zheng-Hang; Zhao, Jing-Yu; Liu, Yun-Long

    2016-07-01

    Pegmatites commonly form in the waning stage of magma evolution by fractional crystallization of volatile-rich magmas and may be important host rocks of strategic metals (e.g., Li, Be, Cs, Ta, and Nb) and high-quality gem minerals. This study reports new zircon U-Pb dating results and Hf isotopic compositions of the KLA803 pegmatite, the AZB-01 pegmatite, the JMK-09 pegmatite (abbreviated as the K-A-J pegmatites) and the Halong granite from the Chinese Altay to determine the potential petrogenetic relationships between them. The geochronological data document that the K-A-J pegmatites were emplaced at 224.6 ± 2.3 Ma, 191.6 ± 2.0 Ma and 192.0 ± 2.3 Ma, respectively, and they are characterized by negative to low positive εHf(t) values (from -1.0 to +6.3) and old model ages (TDM) (with the TDM1 from 874 to 597 Ma and TDM2 from 1298 to 833 Ma). In contrast, the Halong granite has an emplacement age of 398.3 ± 2.4 Ma and is characterized by higher positive εHf(t) values (from +9.9 to +15.2) and younger model ages (TDM) (with the TDM1 from 626 to 414 Ma and TDM2 from 760 to 423 Ma). They all have intruded into the Kulumuti group stratum, which has negative initial εNd(t) values (from -4.3 to -0.2) and old TDM model ages (between 1.22 and 1.56 Ga). Based on the calculated results of the mixing ratios (f) of the initial magmas and the prevailing Paleozoic tectonic framework of the Chinese Altay, we establish two petrogenetic models for the K-A-J pegmatites: Model 1 refers to that these pegmatites originated from a mixed magma that was composed of 72-91 wt.% depleted mantle components and 9-28 wt.% lower crust components; and Model 2 refers to that they were derived from the partial melting of 38-83 wt.% Halong granite and 17-62 wt.% sedimentary rocks from the Kulumuti group. We also suggest that the initial magma of the Halong granite was significantly contributed by juvenile materials with a slight involvement of crustal materials. In Model 1, because LCT

  8. Freely Drifting Swallow Float Array: August 1988 Trip Report

    DTIC Science & Technology

    1989-01-01

    8217 N, 1200 08.03’ W. 08:17 The first ship is sighted (re Section Ic ). Track the ship for the next 36 minutes. 08:18 Seal bomb number 3 is deployed...h) Geophone Time Series Recorded on the Sproul’s Deck Figures XI.la through Ic show the geophone time series recorded by float 2 while it was still...D CD CIO .. .. ’o C DC C CI CD CI a) CI C I C I SIA ’kaJ2o4q posy ssodwoo pluo Figure VIJ.1 (S> C-O L co co LO) C-C, C : .... .. . .,4- 0 - oz 0 IC

  9. On the genesis of the idiotypic network theory.

    PubMed

    Civello, Andrea

    2013-01-01

    The idiotypic network theory (INT) was conceived by the Danish immunologist Niels Kaj Jerne in 1973/1974. It proposes an overall view of the immune system as a network of lymphocytes and antibodies. The paper tries to offer a reconstruction of the genesis of the theory, now generally discarded and of mostly historical interest, first of all, by taking into account the context in which Jerne's theoretical proposal was advanced. It is argued the theory challenged, in a sense, the supremacy of the clonal selection theory (CST), this being regarded as the predominant paradigm in the immunological scenario. As CST found shortcomings in explaining certain phenomena, anomalies, one could view INT as a competing paradigm claiming to be able to make sense of such phenomena in its own conceptual framework. After a summary outline of the historical background and some relevant terminological elucidations, a narrative of the various phases of elaboration of the theory is proposed, up to its official public presentation.

  10. Boron Nitride and Silicon Nitride Systems

    DTIC Science & Technology

    1991-02-01

    2381.43 [85VilJ 13-B a=1098.B6 [SiCre) at 2.4atCr c=2385.14 Cr aB oF40 a=1470.6 (879mi) 򒼎* Fddd b= 741.33 o -Kn ZB o = 425.35 CrwBq t132 a= 546.40...2095* CMOs b= 788.89 CrB 0: 293.33 Cr vB4 0114 a= 298.58 [879miJ * 2075* Iam b=1302.2 TaB94 o = 295.25 135 CraBs oC20 a= 302.84 [870kaJ Cues b=1811.5...1-2x)*+13700(1-2x)’) 0.3632 Cr 20 o ., AtG : -30663.4+15.22 T (78Fro] 138 Fig.l: The binary system Cr 8 ; based on [7lPra,BBMasJ and Chromium - Boron

  11. High Precision Bright-Star Astrometry with the USNO Astrometric CMOS Hybrid Camera System

    NASA Astrophysics Data System (ADS)

    Secrest, Nathan; Dudik, Rachel; Berghea, Ciprian T.; Hennessy, Greg; Dorland, Bryan

    2015-05-01

    While GAIA will provide excellent positional measurements of hundreds of millions of stars between 5 < mag < 20, an ongoing challenge in the field of high-precision differential astrometry is the positional accuracy of very bright stars (mag < 5), due to the enormous dynamic range between bright stars of interest, such as those in the Hipparcos catalog, and their background field stars, which are especially important for differential astrometry. Over the past few years, we have been testing the USNO Astrometric CMOS Hybrid Camera System (UAHC), which utilizes an H4RG-10 detector in windowing mode, as a possible solution to the NOFS USNO Bright Star Astrometric Database (UBAD). In this work, we discuss the results of an astrometric analysis of single-epoch Hipparcos data taken with the UAHC from the 1.55m Kaj Strand Astrometric Reflector at NOFS from June 27-30, 2014. We discuss the calibration of this data, as well as an astrometric analysis pipeline we developed that will enable multi-epoch differential and absolute astrometry with the UAHC. We find that while the overall differential astrometric stability of data taken with the UAHC is good (5-10 mas single-measurement precision) and comparable to other ground-based astrometric camera systems, bright stars in the detector window suffer from several systematic effects, such as insufficient window geometry and centroiding failures due to read-out artifacts - both of which can be significantly improved with modifications to the electronics, read-out speed and microcode.

  12. [The early history of the Danish twin registry].

    PubMed

    Harvald, B; Hauge, G

    1999-01-01

    The Danish Twin Registry was initiated at the Copenhagen University Institute for Human Genetics in 1954 by professor Tage Kemp and his assistants, Bent Harvald and Mogens Hauge. The project was until 1960 primarily financed by US National Cancer Institutes. Twin pairs both of same and different sex, born 1870-1910 were drawn from the birth registers and followed-up through the national registers until death or present place of living. Later on same sex pairs born 1911-30 were added. Besided cancer a multitude of other disorders were registered. Intensive studies on identical twins grown up apart were undertaken by Niels Juel-Nielsen, on criminal behaviour by Karl O. Christiansen, on smoking habits by Elisabeth Raaschou-Nielsen, on peptic ulcer by Kaj Gotlieb Jensen, on schizophrenia by Margit Fischer. Among early remarkable results should be mentioned the modest influence of genetic versus environmental factors in most cases of cancer, the strong genetic impact in mental and moral qualities, the approximate genetic/environmental ratio of 50/50 for the orgin of criminal behaviour and a corresponding ratio of 25/75 for life expectancy. In 1971 the Danish Twin Registry was moved to Odense Universty.

  13. Evaluation of Anticancer Activity of Fruit and Leave Extracts from Virus Infected and Healthy Cultivars of Vitis vinifera.

    PubMed

    Esfahanian, Zahra; Behbahani, Mandana; Shanehsaz, Mehrnaz; Hessami, Mohammad Javad; Nejatian, Mohammad Ali

    2013-01-01

    Grape virus diseases are a serious problem in Iran. Leaves and fruits of grape have been used for different purposes like cooking in Iran. The present investigation was carried out to study on the cytotoxic-activities of extracts of fruits and leaves of Vitis vinifera from both virus-free and virus-infected grape cultivars against breast cancer cell line (MDAMB- 231) and human embryonic kidney normal cell line (HEK 293). IN THIS EXPERIMENTAL STUDY, THE CONSIDERED GRAPE CULTIVARS WERE AS FOLLOWS: Rish Baba Sefid, Shahani Ghasre Shirin, Rotabi Zarghan, Asgari Najaf Abad, Fars, Kaj Angor Bojnord, Sarkesh Shiraz and Siahe Zarqan. A real-time multiplex polymerase chain reaction (real-time Multiplex PCR) assay was applied to detect virus infected cultivars. The cytotoxic effect of the methanol extracts of different Vitis vinifera varieties on cultured cells was monitored using (3- (4, 5-Dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide (MTT) assay at different concentrations (62.5, 125, 250, 500, 750, 1000 μg mL(-1)). Among these cultivars, Grapevine fanleaf virus (GFLV) along with related symptoms was detected in Siahe Zarqan and Fars. Methanolic extracts of leaves and fruits of Vitis vinifera from both virus free and virus infected cultivars showed a range of limited to moderate cytotoxic activity. However, methanol extract of leaves belonged to virus infected cultivars was found to have strong cytotoxic effect against MDA-MB-231 at different concentrations. Grapevine fanleaf virus (GFLV) can potentially increase the cytotoxicity of grape cultivars.

  14. Placing SOFIA in the central flash for the 29 June 2015 Pluto Occultation

    NASA Astrophysics Data System (ADS)

    Zuluaga, Carlos A.; Bosh, Amanda S.; Person, Michael J.; Levine, Stephen E.; Bright, Len P.; Harris, Hugh C.; Tilleman, Trudy; Thanathibodee, Thanawuth; Weisenbach, Luke W.

    2015-11-01

    We report on the astrometry prediction process carried out for the 29 June 2015 occultation of an 11.9 magnitude star by Pluto. The occultation star, UCAC2 139-209445 was first identified in 2013 as a good candidate for an occultation to be observed with Stratospheric Observatory for Infrared Astronomy (SOFIA) due to the circumstances of the event. In addition, the event's proximity to the New Horizons encounter with Pluto made the event even more timely. We were awarded time on SOFIA for the Pluto occultation in 2014. From mid-2014 up through the night of the occultation, we tracked Pluto's position. We collected astrometric data from four telescopes: the SARA-CT telescope located in Cerro Tololo International Observatory, Chile; the Lowell Observatory 42-inch Hall telescope; the Lowell Observatory 4.3-m Discover Channel Telescope, both in Flagstaff, AZ; and the USNO 1.55-m Kaj Strand telescope in Flagstaff, AZ. The objective of the astrometric observations was to improve the prediction enough to place the aircraft within the central flash zone (approximately ±75 km, 5mas, from the center line of the Pluto shadow).The prediction uncertainties included those of the star position and proper motion, Pluto ephemeris offset, potential zone-dependent offsets in the reference catalog, unknown stellar duplicity, and center-of-mass to center-of-light offsets. Over the two years since we identified this event as promising, we worked to steadily decrease each of the sources of uncertainty.We communicated prediction updates to the SOFIA flight planning team. We provided a pre-take-off update, which was then followed by a later in-flight update that necessitated a change in the flight plan of 320 km. The crew were able to implement this change and SOFIA was able to capture the central flash of this event (Bosh et al., and Person et al., this conference).

  15. High Precision Bright-Star Astrometry with the USNO Astrometric CMOS Hybrid Camera System

    NASA Astrophysics Data System (ADS)

    Secrest, Nathan; Dudik, Rachel; Berghea, Ciprian; Hennessy, Greg; Dorland, Bryan

    2015-08-01

    While GAIA will provide excellent positional measurements of hundreds of millions of stars between 5 < mag < 20, an ongoing challenge in the field of high-precision differential astrometry is the positional accuracy of very bright stars (mag < 5), due to the enormous dynamic range between bright stars of interest, such as those in the Hipparcos catalog, and their background field stars, which are especially important for differential astrometry. Over the past few years, we have been testing the USNO Astrometric CMOS Hybrid Camera System (UAHC), which utilizes an H4RG-10 detector in windowing mode, as a possible solution to the NOFS USNO Bright Star Astrometric Database (UBAD). In this work, we discuss the results of an astrometric analysis of single-epoch Hipparcos data taken with the UAHC from the 1.55m Kaj Strand Astrometric Reflector at NOFS from June 27-30, 2014. We discuss the calibration of this data, as well as an astrometric analysis pipeline we developed that will enable multi-epoch differential and absolute astrometry with the UAHC. We find that while the overall differential astrometric stability of data taken with the UAHC is good (5-10 mas single-measurement precision) and comparable to other ground-based astrometric camera systems, bright stars in the detector window suffer from several systematic effects, such as insufficient window geometry and centroiding failures due to read-out artifacts—both of which can be significantly improved with modifications to the electronics, read-out speed and microcode.

  16. Keepers of the double stars

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-03-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Early catalogues by the Herschels, Struves, and others began with their own discoveries. In 1906 court reporter and amateur astronomer Sherburne Wesley Burnham published a massive double star catalogue containing data from many observers on more than 13,000 systems. Lick Observatory astronomer Robert Grant Aitken produced a much larger catalogue in 1932 and coordinated with Robert Innes of Johannesburg, who catalogued the southern systems. Aitken maintained and expanded Burnham's records of observations on handwritten file cards, and eventually turned them over to the Lick Observatory, where astrometrist Hamilton Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and together they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford had the new 120-inch reflector, the world's second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the United States Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley, and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,200,000 measures of more than 125

  17. Hamilton Jeffers and the Double Star Catalogues

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-01-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Court reporter and amateur astronomer Shelburne Wesley Burnham (1838-1921) published a massive double star catalogue containing more than 13,000 systems in 1906. The next keeper of the double stars was Lick Observatory astronomer Robert Grant Aitken (1864-1951), who produced a much larger catalogue in 1932. Aitken maintained and expanded Burnham’s records of observations on handwritten file cards, eventually turning them over to Lick Observatory astrometrist Hamilton Moore Jeffers (1893-1976). Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby (1921-2002), he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford (1905-2002) had the new 120-inch reflector, the world’s second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the U.S. Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley (1935-1997), and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,000,000 measures of more than 100,000 pairs.

  18. Effect of the different cover crops on the soil moisture in a Hungarian vineyard

    NASA Astrophysics Data System (ADS)

    Donkó, Ádám; Miglécz, Tamás; Valkó, Orsolya; Deák, Balázs; Kelemen, András; Török, Péter; Tóthmérész, Béla; Drexler, Dóra

    2017-04-01

    Since many years it is well known that the one-sided mechanical soil cultivation of vineyard inter-rows has many disadvantages. Growers can choose from alternative tillage technologies, such as the usage of green manure, or covering the inter-rows with straw mulch. Another possible technology is tto cover the inter-rows with species-rich seed mixtures. However, selection of the most suitable species is crucial; we have to take into consideration the age of the vines, and the specific characteristics of the vineyards involved. Species rich cover crop technology has many advantages: 1) it helps to prevent erosion and creates easier cultivation circumstances, 2) it has a positive effect on soil structure, soil fertility and ecosystem services, 3) we can create native mixtures from local provenance, adapted to the local climate/vine region/vineyard which enhances the nature conservation value of our site. But, they should not compete significantly with the grapevines, or negatively influence produce quality. In the year of 2012 we created, and started to study three different cover-crop mixtures in Hungarian wine regions under on-farm conditions: Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs. The results of the botanical surveys, yield and pruning weight were published in many papers and presentations before (e.g. Miglécz et al. 2015, Donkó et al. 2016). Besides the above measures, one key point of the effectiveness and sustainability of the living mulch vegetation is the level of soil moisture. That is why we started to investigate the soil moisture (vol %) of different treatments (Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs, coverage with Lolium perenne, and Control (spontaneous weed flora)) in at the Feind Winery in Balatonfőkajár (Hungary). The investigated variety is Welschriesling on loamy soil (Tihany Formation), planted in 2010. The seed mixtures were sown in the spring of 2013. We measured soil moisture

  19. Fused Deposition Modelling as Rapid Prototyping for Structural Material Improvement: Analytical Solution / Ātrās Prototipēšanas Ar Kausēšanas Metodi Strukturālā Uzlabojuma Analītisks Risinājums

    NASA Astrophysics Data System (ADS)

    Brensons, I.; Polukoshko, S.

    2013-10-01

    Fused deposition modelling (FDM) is one of the most effective rapid prototyping (RP) techniques due to its low cost, available materials and versatility. In FDM, a part of material (usually plastic) is made by heating this material to the molten state, and from the melt it is extruded through a nozzle and deposited on a surface. In the article, an alternative RP method is considered for improvement of the mechanical properties of a rapid prototype. The authors propose an analytical solution which allows for achievement of this purpose via advanced technologies. The base materials applied in RP technology can be combined with liquid resin which solidifies after a definite time. This makes it possible to create a channel through the prototype and fill it with another material having better mechanical properties. The optimal channel sizes can be chosen in order to raise the strength of material parts. Darbā tiek apskatīts ātrās prototipēšanas veids, kura pamatā ir detaļas veidošana, izmantojot kausētu materiālu parasti plastmasu. Šī detaļu veidošanas metode ir kļuvusi par vienu no visizplatītākajām tās zemo izmaksu, pieejamo materiālu un daudzpusības dēļ. Šī raksta mērķis ir izpētīt alternatīvu veidu, kā uzlabot prototipu mehāniskās īpašības, tādējādi palielinot printētu detaļu izmantošanu kā gala produktu. Raksts piedāvā analītisku risinājumu, kā uzlabot ātro prototipu mehāniskās īpašības, uzlabojot tehnoloģiskos procesus, kas iesaistīti detaļu izgatavošanā. Darba pamatā tiek izmantota 3D printēšanas tehnoloģijas iespēja veidot iekšējus kanālus bez ģeometriskiem ierobežojumiem, kā rezultātā ir iespējams izveidot iekšēju kanālu shēmu, ko pēc tam piepilda ar citu materiālu, kam ir labākas mehāniskās īpašības kā pamata materiālam. Pildīšanai izmantotais materiāls ir epoksīda sveķi, kas pieļauj vieglu iepildīšanu šķidrā fāzē, un sniedz labas mehāniskās īpašības p

  20. Obituary: Richard L. (Dick) Walker, Jr., 1938-2005

    NASA Astrophysics Data System (ADS)

    Pier, Jeffrey R.; Mason, Brian

    2005-12-01

    . While measuring known systems for orbital analysis, he discovered 22 pairs (mostly additional components to these systems) and moving pairs, and his highlighting the rapid motion of these systems resulted in them being placed on many programs and led to the more definitive orbits of today. As a staff member of the Flagstaff Station, Dick was, for over 30 years, one of the principal observers on the 61-inch parallax program. He also ventured into other areas of astronomy, including planetary systems. He is credited with discovering the moon of Saturn, Epimetheus, in December 1966, with the USNO Flagstaff Station 61-inch Kaj Strand Astrometric Reflector. He also obtained photographic plates to determine accurate positions of the outer planets for the Voyager 2 approaches to Uranus in 1986 and Neptune in 1989. It is interesting to note that Dick's career in observational astronomy spanned three different eras of astronomical instrumentation and technique. He began his career doing eyeball astronomy, using a filar micrometer to measure double star separations. Photographic astronomy then became dominant and he took many thousands of plates. During the last ten years of his career, electronic cameras, primarily CCDs, replaced photographic plates. He readily adapted to the changing technologies. A man of many interests, Dick was fascinated by the history of astronomy, especially archeoastronomy, as well as Egyptology. He taught himself the language of hieroglyphics. In 1977, having accumulated several weeks of vacation time, he set off on a trek to walk the Nile for 500 miles from Aswan to Cairo. One night, in the town Asyut along the Nile, he was brought into the police station. The local inhabitants found it hard to credit his story that he was simply on a walk and questioned him as a possible Israeli spy. Following his retirement from the Naval Observatory, Dick consulted in a couple of construction projects. He designed the analemma and the skywalk star fields for the