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Sample records for sand tray therapy

  1. Implementing Adlerian Sand Tray Therapy with Adult Male Substance Abuse Offenders: A Phenomenological Inquiry

    Science.gov (United States)

    Monakes, Sarah; Garza, Yvonne; Wiesner, Van, III; Watts, Richard E.

    2011-01-01

    The purpose of this phenomenological study was to understand the perceptions of adult male substance offenders who experienced sand tray therapy as an adjunct to their cognitive behavioral rehabilitative treatment. Results indicate a positive experience for participants. Implications for counselors are discussed. (Contains 1 table.)

  2. Implementing Adlerian Sand Tray Therapy with Adult Male Substance Abuse Offenders: A Phenomenological Inquiry

    Science.gov (United States)

    Monakes, Sarah; Garza, Yvonne; Wiesner, Van, III; Watts, Richard E.

    2011-01-01

    The purpose of this phenomenological study was to understand the perceptions of adult male substance offenders who experienced sand tray therapy as an adjunct to their cognitive behavioral rehabilitative treatment. Results indicate a positive experience for participants. Implications for counselors are discussed. (Contains 1 table.)

  3. Using Sand Trays and Miniature Figures to Facilitate Career Decision Making

    Science.gov (United States)

    Sangganjanavanich, Varunee Faii; Magnuson, Sandy

    2011-01-01

    Sand tray therapy has earned status as a respected, often powerful, therapeutic modality. Counselors have used sand trays and figures for a variety of purposes with children, adolescents, adults, families, and groups. This modality can also be used to facilitate career decision making and related issues as clients create visual representations of…

  4. Using Sand Trays and Miniature Figures to Facilitate Career Decision Making

    Science.gov (United States)

    Sangganjanavanich, Varunee Faii; Magnuson, Sandy

    2011-01-01

    Sand tray therapy has earned status as a respected, often powerful, therapeutic modality. Counselors have used sand trays and figures for a variety of purposes with children, adolescents, adults, families, and groups. This modality can also be used to facilitate career decision making and related issues as clients create visual representations of…

  5. Change during Psychotherapy through Sand Play Tray in Children That Have Been Sexually Abused.

    Science.gov (United States)

    Tornero, María D L Angeles; Capella, Claudia

    2017-01-01

    This paper presents the results of a qualitative study on the use of sandplay, or sand tray therapy, in the psychotherapeutic process of children who have been sexually abused. A longitudinal study was carried out with seven participants between the ages of 7 and 10 years old. Data was produced during observation of the therapeutic activity over the course of three different phases of treatment, using a rubric created especially for this observation. Three sandplay sessions were recorded: one at the start of therapy, one at the 3-month mark, and the third and final session after 6 months of treatment. Sessions were then transcribed for later analysis. A rubric was developed in order to help researchers identify central themes, behaviors and content of creative play, as well as the therapeutic relationship. Transcribed sessions and observation rubrics were evaluated using qualitative content analysis, and information was categorized according to verbal and behavioral characteristics of the game. Results of the present study reveal common and transversal forms of playful expression among this group of children shown by their engagement with sandplay. During this activity, participants elaborate personal stories that feature violence as a central theme, often involving aggression between two or more individuals. They also express their need for care and protection and work to resolve conflicts using fantasy. The shifting dynamics of sandplay at each stage of therapeutic treatment is an important finding that reveals the progress made during psychotherapy. In the third phase of treatment, sandplay encouraged movement among children, allowing them to act out meaningful scenarios and create structured situations with positive outcomes. Finally, the value of sandplay as an important therapeutic tool is discussed, primarily its role in supporting processes of change and allowing participants to assign new meanings to traumatic experiences. Its application to the field of

  6. Change during Psychotherapy through Sand Play Tray in Children That Have Been Sexually Abused

    Directory of Open Access Journals (Sweden)

    María D. L. Angeles Tornero

    2017-05-01

    Full Text Available This paper presents the results of a qualitative study on the use of sandplay, or sand tray therapy, in the psychotherapeutic process of children who have been sexually abused. A longitudinal study was carried out with seven participants between the ages of 7 and 10 years old. Data was produced during observation of the therapeutic activity over the course of three different phases of treatment, using a rubric created especially for this observation. Three sandplay sessions were recorded: one at the start of therapy, one at the 3-month mark, and the third and final session after 6 months of treatment. Sessions were then transcribed for later analysis. A rubric was developed in order to help researchers identify central themes, behaviors and content of creative play, as well as the therapeutic relationship. Transcribed sessions and observation rubrics were evaluated using qualitative content analysis, and information was categorized according to verbal and behavioral characteristics of the game. Results of the present study reveal common and transversal forms of playful expression among this group of children shown by their engagement with sandplay. During this activity, participants elaborate personal stories that feature violence as a central theme, often involving aggression between two or more individuals. They also express their need for care and protection and work to resolve conflicts using fantasy. The shifting dynamics of sandplay at each stage of therapeutic treatment is an important finding that reveals the progress made during psychotherapy. In the third phase of treatment, sandplay encouraged movement among children, allowing them to act out meaningful scenarios and create structured situations with positive outcomes. Finally, the value of sandplay as an important therapeutic tool is discussed, primarily its role in supporting processes of change and allowing participants to assign new meanings to traumatic experiences. Its

  7. Topical Tacrolimus with Custom Trays in the Treatment of Severe Oral cGVHD Refractory to a Potent Topical Steroid Therapy: A Case Report

    Science.gov (United States)

    Brown, Ronald S.; Edwards, Dean; Walsh-Chocolaad, Tracey; Childs, Richard W.

    2012-01-01

    Background The authors present a case demonstrating the success of topical tacrolimus (TAC) therapy with custom trays in the treatment of oral chronic graft versus host disease (cGVHD). The 41 year-old male patient initially responded to topical steroid therapy (clobetasol propionate 0.05% ointment) applied both topically and with flexible carrier trays, but later became refractory to this potent topical agent. Topical TAC therapy with flexible carrier trays and systemic prednisone therapy was initiated. Results The patient responded favorably with the change to topical TAC therapy with custom trays (and oral prednisone). His oral cGVHD lesions resolved within a period of four weeks. The improvement has remained stable at 14 month follow-up. Clinical Implications This is the first case reported with regard to the successful resolution of steroid recalcitrant cGVHD successfully treated with topical TAC with custom trays. PMID:23102802

  8. Integrating Sand Tray and Solution Focused Brief Counseling as a Model for Working with Middle School Students

    Science.gov (United States)

    McBrayer, Rachel H.; Chibbaro, Julia S.

    2012-01-01

    School counselors are master jugglers and must assume a variety of roles and tasks in order to be successful. Despite common misconceptions, Play Therapy is not for exclusive use with younger children. In fact, adolescents can also benefit from its unique properties. One integrated technique that could prove to be especially helpful with middle…

  9. Integrating Sand Tray and Solution Focused Brief Counseling as a Model for Working with Middle School Students

    Science.gov (United States)

    McBrayer, Rachel H.; Chibbaro, Julia S.

    2012-01-01

    School counselors are master jugglers and must assume a variety of roles and tasks in order to be successful. Despite common misconceptions, Play Therapy is not for exclusive use with younger children. In fact, adolescents can also benefit from its unique properties. One integrated technique that could prove to be especially helpful with middle…

  10. Influence of tray hydraulics on tray column

    NARCIS (Netherlands)

    Betlem, Bernardus H.L.; Rijnsdorp, J.E.; Rijnsdorp, J.E.; Azink, R.F.

    1998-01-01

    To column control, in contrast to column design, tray hold-up and dependencies of tray hold-up on the operating conditions play an important role. The essence of this article is the development of an improved model of tray hydraulics over a broad operating range and its experimental validation by

  11. The experience of use of the sand art-therapy with children with autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Kotlovanova O.V.

    2015-06-01

    Full Text Available The article presents the results of effective work to use sand art-therapy for treatment of behavior problems in children with autism spectrum disorder. The article describes the session plan, children's behavior in dynamics and intermediate results of work with children with autism spectrum disorders in the framework of this program. The influence of the sand art-therapy on the children's behavior was analyzed. The clinical case of sessions with the boy K. was described. The overwhelmingly positive influence of such sessions was determined.

  12. Sandplay therapy with couples within the framework of analytical psychology.

    Science.gov (United States)

    Albert, Susan Carol

    2015-02-01

    Sandplay therapy with couples is discussed within an analytical framework. Guidelines are proposed as a means of developing this relatively new area within sandplay therapy, and as a platform to open a wider discussion to bring together sandplay therapy and couple therapy. Examples of sand trays created during couple therapy are also presented to illustrate the transformations during the therapeutic process. © 2015, The Society of Analytical Psychology.

  13. Automatic agar tray inoculation device

    Science.gov (United States)

    Wilkins, J. R.; Mills, S. M.

    1972-01-01

    Automatic agar tray inoculation device is simple in design and foolproof in operation. It employs either conventional inoculating loop or cotton swab for uniform inoculation of agar media, and it allows technician to carry on with other activities while tray is being inoculated.

  14. Flexible Interior-Impression-Molding Tray

    Science.gov (United States)

    Anders, Jeffrey E.

    1991-01-01

    Device used inside combustion chamber of complicated shape for nondestructive evaluation of qualities of welds, including such features as offset, warping, misalignment of parts, and dropthrough. Includes flexible polypropylene tray trimmed to fit desired interior surface contour. Two neodymium boron magnets and inflatable bladder attached to tray. Tray and putty inserted in cavity to make mold of interior surface.

  15. Effectiveness of Sand-Therapy on the Attenuation of Separation anxiety Signs in Pre-School Children

    Directory of Open Access Journals (Sweden)

    Arghavan Shariat

    2015-01-01

    Full Text Available Background and Objective: The present research was conducted with the aim of determining effect of Sand-therapy on the attenuation of separation anxiety signs among pre-school children in Isfahan, Iran. Methods: The statistical society consists of all pre-school children who had separation anxiety disorder and Among100 children, 30 persons were selected using available sampling. The method of this research is quasi-experimental with one group and pre-test and post-test plan. After performing pre-test of separation anxiety disorder scale, the experimental group were trained under sand-therapy training in 10 sessions of 60 minutes for a period of two months and after that, post-test of separation anxiety disorder scale was performed. The research tool consists of the questionnaire CSI-4 of child’s morbid signs. Wilcoxon method was used to analysis the results. Results: The research findings showed that there was a meaningful different (P=0.008 between pre- test & post-test scores of anxiety signs for study group.Conclusion: As a practical message, we can mention that sand therapy is as an interesting and practical playing for the children and it is a meaningful therapy related to attenuation of separation anxious signs.Keywords: Sand therapy, separation anxiety, pre-school-children

  16. Disinfection effect of dental impression tray adhesives.

    Science.gov (United States)

    Bensel, Tobias; Pollak, Rita; Stimmelmayr, Michael; Hey, Jeremias

    2013-03-01

    Iatrogenic infections are serious problems in dental offices. Impression tray adhesives are delivered in glass containers with a fixed brush attached inside the cap. Using the brush for application of the impression tray adhesive on a contaminated impression tray or prostheses, pathogen transmission by replacing the cap with the brush is possible. Bacterial strains (patient strains and in vitro strains) were supervaccinated on Columbia agar. The bacterial solution was diluted with TSB and aerobically grown, and starting concentration was 1 × 10(7) cfu/ml. The stock solution was placed on Columbia agar. Alginate, polyether, and silicon impression tray adhesives were applied to the center of the particular blood agar plates and incubated for 48 h. The expansion of the inhibition zone assays were measured using a microscope. Twenty-one different bacterial strains were selected in the saliva samples of 20 patients. The growth inhibition for alginate impression tray adhesive was 1.1 % (±0.3) of the patient strains. The overgrowth of polyether impression tray adhesive was 30.6 % (±9.3) and for silicon impression tray adhesive 11.8 % (±5.0). In in vitro strains, alginate impression tray adhesive performed an inhibition of 0.7 % (±0.3). The overgrowth of polyether impression tray adhesive was 7.0 % (±1.6) and for silicon impression tray adhesive was 6.5 % (±1.3). Using the fixed brush for application of the impression tray adhesive on multiple patients, a cross-contamination cannot be ruled out. An application of the impression tray adhesive with a pipette and a single-use brush would eliminate the contamination.

  17. Develop and Manufacture an airlock sliding tray

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Cindy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-26

    Objective: The goal of this project is to continue to develop an airlock sliding tray and then partner with an industrial manufacturing company for production. The sliding tray will be easily installed into and removed from most glovebox airlocks in a few minutes. Technical Approach: A prototype of a sliding tray has been developed and tested in the LANL cold lab and 35 trays are presently being built for the plutonium facility (PF-4). The current, recently approved design works for a 14-inch diameter round airlock and has a tray length of approximately 20 inches. The grant will take the already tested and approved round technology and design for the square airlock. These two designs will be suitable for the majority of the existing airlocks in the multitude of DOE facilities. Partnering with an external manufacturer will allow for production of the airlock trays at a much lower cost and increase the availability of the product for all DOE sites. Project duration is estimated to be 12-13 months. Benefits: The purpose of the airlock sliding trays is fourfold: 1) Mitigate risk of rotator cuff injuries, 2) Improve ALARA, 3) Reduce risk of glovebox glove breaches and glove punctures, and 4) Improve worker comfort. I have had the opportunity to visit many other DOE facilities including Savannah, Y-12, ORNL, Sandia, and Livermore for assistance with ergonomic problems and/or injuries. All of these sites would benefit from the airlock sliding tray and I can assume all other DOE facilities with gloveboxes built prior to 1985 could also use the sliding trays.

  18. Ifa Divination Trays from Isale-Oyo

    Directory of Open Access Journals (Sweden)

    O. I. Pogoson

    2011-10-01

    Full Text Available This paper is a study of the images and patterns on ifa divination trays from Isale-Oyo. The paper also explains some ifa paraphernalia. The paper establishes that ifa trays from Isale-Oyo bear distinctive features when compared with other ifa trays in Yorubaland such as those of Ijebu and Osogbo. Central to this study is the iconographic description and interpretations of Isale-Oyo divination trays. Data were collected through direct interviews with divination tray owners. Photographs of the trays were also taken. The investigation revealed that:Divination trays from Isale-Oyo combine features found on both Ijebu and Osogbo trays.The Esu figure continues to occupy the top central position on Oyo divination trays, even though with representational variations elsewhere in Yorubaland.Some divination trays in Oyo carry no decorations on their borders, and in some recent cases, ceramic plates are now used for divination.Este artigo trata dos padrões e imagens dos tabuleiros de adivinhação ifa usados em Isale-Oyo (Nigéria, bem como de outros objectos religiosos associados. Argumenta-se que os tabuleiros ifa de Isale-Oyo têm características que os distinguem de outros tabuleiros ifa da região yoruba, como os de Ijebu e Osogbo. A descrição e a interpretação da iconografia dos tabuleiros de adivinhação constituem o foco deste estudo. Os dados discutidos foram recolhidos através de entrevistas a proprietários de tabuleiros de adivinhação e fotografias de tabuleiros. Conclui-se que:Os tabuleiros de adivinhação de Isale-Oyo combinam traços dos tabuleiros de Ijebu e dos tabuleiros de Osogbo.A figura de Esu continua a ocupar a posição central superior nos tabuleiros de adivinhação de Oyo, embora se registem variações na sua representação noutras zonas do território yoruba.Alguns tabuleiros de adivinhação de Oyo não possuem qualquer decoração nos frisos, e nalguns casos recentes vêm sendo utilizados na adivinhação pratos

  19. 21 CFR 872.6870 - Disposable flouride tray.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Disposable flouride tray. 872.6870 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6870 Disposable flouride tray. (a) Identification. A disposable fluoride tray is a device made of styrofoam intended to apply fluoride topically to...

  20. 21 CFR 872.6880 - Preformed impression tray.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Preformed impression tray. 872.6880 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6880 Preformed impression tray. (a) Identification. A preformed impression tray is a metal or plastic device intended to hold impression material...

  1. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic cabinet, table, or tray. 868.6100 Section 868.6100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  2. 21 CFR 884.1550 - Amniotic fluid sampler (amniocentesis tray).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Amniotic fluid sampler (amniocentesis tray). 884... Diagnostic Devices § 884.1550 Amniotic fluid sampler (amniocentesis tray). (a) Identification. The amniotic fluid sampler (amniocentesis tray) is a collection of devices used to aspirate amniotic fluid from...

  3. 21 CFR 872.3670 - Resin impression tray material.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670...

  4. The Skills Minister's In-Tray

    Science.gov (United States)

    Hancock's, Matthew

    2012-01-01

    In the "Adults Learning" autumn issue, the journal staff asked key players in the learning and skills sector what they thought should be at the top of new skills minister Matthew Hancock's in-tray. The new minister shares that his job in the further education and skills sector is to rise to the challenge and play his full part in giving…

  5. Natural radioactivity in sand used in thermal therapy at the Red Sea Coast.

    Science.gov (United States)

    El-Arabi, A M

    2005-01-01

    The development of climatotherapy in Safaga opens the field of medical tourism in Egypt, in order to detect any harmful radiation that would affect the patients during treatment and is becoming important economic resource. Studies and survey of natural radiation and radioactivity in upper Egypt conducted since 1990, included monitoring of the concentration of natural radionuclides in environmental samples. The results of the study reveals that, for all sand samples, the mean activity concentration of 40K (618+/-122-548+/-82 Bq kg(-1)) are much higher than that of both 226Ra (25.3+/-14-20.6+/-10 Bq kg(-1)) and 232Th (21.4+/-10-22.4+/-10 Bq kg(-1)). Different radiation hazard indices were calculated, the radiation dose to which workers are subjected is not negligible (26.5-50.9 nGy h(-1)), although depending on the inhalation of dust.

  6. CoFlo tray Design and Technology Report

    Energy Technology Data Exchange (ETDEWEB)

    William R. Trutna

    2005-04-04

    This report consists of two major segments. CoFlo Tray Design is the first section. The objectives of this section are: (1) Determine the design requirements for increased capacity by the substitution of CoFlo trays for sieve trays in a 15-tray 46-inch diameter column. The Design Basis was obtained from the Separations Research Program, which was solicited by an industrial customer on the use of CoFlo trays for their application. (2) Illustrate the design procedures so that they can be computerized to rapidly provide design and cost information for future customers. A summary of the research studies on which each design procedure is based is included. (3) Compare the costs of new sieve tray and CoFlo tray columns for this application to illustrate the savings inherent in the CoFlo process. Exhibits are the second section of this report and its objectives are to: (a) Report the extensive research studies on the CoFlo tray and related items; (b) Analyze present and potential future performance of the CoFlo tray; (c) Present comparative costs for sieve and CoFlo tray columns; and (d) List the applications for the CoFlo deentrainer.

  7. Sensory Analysis of Stored Tray Pack Foods

    Science.gov (United States)

    1989-12-01

    Milk chocolate brown. ODOR: Sweet, typical of heat processed milk cocoa . FLAVOR: Sweet, full milk cocoa flavor. TEXTURE: Smooth, medium thick...7B DEGREES 100 DEGREES 6. DESSERTS Chocolate Pudding There was no significant finding with this Tray Pack item. Marble Cake At 70°F, the effect...and 6 months. The main effect of temperature on acceptability of this item was not significant. Chocolate Cake At 70°F, there was a significant

  8. Automatic surface inoculation of agar trays.

    Science.gov (United States)

    Wilkins, J. R.; Mills, S. M.; Boykin, E. H.

    1972-01-01

    Description of a machine and technique for the automatic inoculation of a plastic tray containing agar media with a culture, using either a conventional inoculation loop or a cotton swab. The design of the machine is simple, it is easy to use, and it relieves the operator from the manual task of streaking cultures. The described technique makes possible the visualization of the overall qualitative and, to some extent, quantitative relationships of various bacterial types in a sample tested.

  9. Drying time of tray adhesive for adequate tensile bond strength between polyvinylsiloxane impression and tray resin material.

    Science.gov (United States)

    Yi, Myong-Hee; Shim, Joon-Sung; Lee, Keun-Woo; Chung, Moon-Kyu

    2009-07-01

    Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material. This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive. Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material (Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level. The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive-Aquasil, and VPS Tray Adhesive-Imprint II had a superior tensile

  10. Comparison of Dimensional Accuracy between Open-Tray and Closed-Tray Implant Impression Technique in 15° Angled Implants

    Directory of Open Access Journals (Sweden)

    Balouch F.

    2013-09-01

    Full Text Available Statement of Problem: Various impression techniques have different effects on the accuracy of final cast dimensions. Meanwhile; there are some controversies about the best technique. Purpose: This study was performed to compare two kinds of implant impression methods (open tray and closed tray on 15 degree angled implants.Materials and Method: In this experimental study, a steel model with 8 cm in diameter and 3 cm in height were produced with 3 holes devised inside to stabilize 3 implants. The central implant was straight and the other two implants were 15° angled. The two angled implants had 5 cm distance from each other and 3.5 cm from the central implant. Dental stone, high strength (type IV was used for the main casts. Impression trays were filled with poly ether, and then the two impression techniques (open tray and closed tray were compared. To evaluate positions of the implants, each cast was analyzed by CMM device in 3 dimensions (x,y,z. Differences in the measurements obtained from final casts and laboratory model were analyzed using t-Test. Results: The obtained results indicated that closed tray impression technique was significantly different in dimensional accuracy when compared with open tray method. Dimensional changes were 129 ± 37μ and 143.5 ± 43.67μ in closed tray and open tray, while coefficient of variation in closed- tray and open tray were reported to be 27.2% and 30.4%, respectively.Conclusion: Closed impression technique had less dimensional changes in comparison with open tray method, so this study suggests that closed tray impression technique is more accurate.

  11. Accuracy of impressions obtained with dual-arch trays.

    Science.gov (United States)

    Wöstmann, Bernd; Rehmann, Peter; Balkenhol, Markus

    2009-01-01

    This study aimed to analyze the accuracy resulting from dual-arch impressions when compared to conventional impressions in complex preparations (ie, inlay and partial crown). One hundred eighty impressions were made using two different dual-arch trays; conventional trays served as the control. The accuracy of the dies obtained (Fuji-Rock EP, GC Europe) was assessed indirectly from the change of 59 transversal dimensions. Statistical analysis (t test, analysis of variance) revealed that less rigid dual-arch trays performed better than rigid ones. Though the inlay preparation was more difficult to reproduce with dual-arch trays, it can be concluded that the accuracy obtainable with nonrigid dual-arch trays is comparable to impressions taken from full-arch trays.

  12. [Progress in research and application of the edentulous custom trays].

    Science.gov (United States)

    Sun, Y C; Jin, E L; Zhao, T; Wang, Y; Ye, H Q; Zhou, Y S

    2016-11-09

    Well designed and fabricated custom tray is the precondition to acquire qualified edentulous impression and key to successful complete denture. It has shown that primary impression without custom trays is hard to meet clinical requirements for successful restoration of complete denture. According to the fabrication techniques, edentulous custom tray can be classified into several types such as: compound trimming technique, handcrafted technique with polymerizing acrylic resin based on the study cast, and computer aided design and three dimensional printing(CAD & 3DP) technique based on the primary impression or study cast, etc. With regard to some special edentulous jaws, the custom tray and impression techniques such as open-window, frame cut, closed-mouth custom trays, and so on can be applied to acquire accurate impressions. All above technologies have their own characteristics and emphases. In clinic, appropriate custom trays should be selected according to residual ridge condition, oral status, and other clinical requirements of each edentulous patient.

  13. Three-way trays: easy to use and abuse.

    Science.gov (United States)

    Pesun, Igor J; Swain, Vanessa L

    2008-12-01

    The 3-way tray technique is popular as it provides master and opposing arch impressions and an interocclusal record at the same time. Excellent clinical results can be achieved with appropriate case selection, use of rigid tray and impression materials, attention to tray positioning and other details throughout the process, and clear understanding of the limitations of the technique by the operator and dental technician.

  14. Prefabricated Stock Trays for Impression of Auricular Region

    OpenAIRE

    Vibha, Shetty; Anandkrishna, G. N.; Anupam, Purwar; Namratha, N.

    2010-01-01

    The conventional methods of impression making for maxillofacial defects are cumbersome and time consuming for both patient and operator. This study focuses upon standardizing and simplifying the impression making methodology for auricular prosthesis with the help of prefabricated stock trays for auricular region. The stock trays were designed on positive replicas of anatomical structures, broadly divided into long and narrow, short and broad and long and broad ear. For each stock tray, impres...

  15. TrayGen: Arranging objects for exhibition and packaging

    KAUST Repository

    Yang, Yongliang

    2013-10-01

    We present a framework, called TrayGen, to generate tray designs for the exhibition and packaging of a collection of objects. Based on principles from shape perception and visual merchandising, we abstract a number of design guidelines on how to organize the objects on the tray for the exhibition of their individual features and mutual relationships. Our framework realizes these guidelines by analyzing geometric shapes of the objects and optimizing their arrangement. We demonstrate that the resultant tray designs not only save space, but also highlight the characteristic of each object and the inter-relations between objects. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

  16. Revisiting impressions using dual-arch trays.

    Science.gov (United States)

    Small, Bruce W

    2012-01-01

    Making routine perfect impressions is the goal of any restorative dentist. Using dual-arch trays is an easy, repeatable way to accomplish that goal, as long as each step is done before the next and each step is performed perfectly. This column reviewed several articles that support the metal dual-arch concept and provided some clinical tips that might help restorative dentists. The dual-arch technique does have its limits and is meant for one or two teeth in a quadrant when there are other teeth to occlude with. Also, if the case involves anterior guidance, a full-arch impression maybe advisable.

  17. Fontainebleau Sand

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    2006-01-01

    The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

  18. A study of the antimicrobial properties of impression tray adhesives.

    Science.gov (United States)

    Herman, D A

    1993-01-01

    Three impression tray adhesives were tested for their antimicrobial actions on three bacteria strains used for disinfectant studies. The colony forming unit (CFU) counts from plating the adhesive-exposed bacteria showed a significant reduction in number compared with the CFU of the controls. Statistical analyses confirmed the significant reduction (p impression tray adhesives can help prevent cross contamination.

  19. 16 CFR Figure 7 to Subpart A of... - Specimen Tray

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Specimen Tray 7 Figure 7 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... to Subpart A of Part 1209—Specimen Tray EC03OC91.037 ...

  20. Entrainment and maximum vapour flow rate of trays

    NARCIS (Netherlands)

    Van Sinderen, AH; Wijn, EF; Zanting, RWJ

    This is a report on free entrainment measurements in a small (0.20 m x 0.20 in) air-water column. An adjustable weir controlled the liquid height on a test tray. Several sieve and valve trays were studied. The results were interpreted with a two- or three-layer model of the two-phase mixture on the

  1. Custom impression trays: Part I--Mechanical properties.

    Science.gov (United States)

    Breeding, L C; Dixon, D L; Moseley, J P

    1994-01-01

    Dimensional stability of custom impression trays is an important factor in determining the degree of accuracy achieved in forming a master cast. Such trays must remain stable over time and must not exhibit permanent deformation when a completed impression is removed from the oral cavity. Measurement of the mechanical properties allows comparison between various tray materials and is useful in interpreting data on stresses incurred during removal of the completed impression. In Part I of this three-part series, the various mechanical properties of five tray resins: one autopolymerizing polymethyl methacrylate, one light-polymerizing, and three brands of thermoplastic resins were recorded and compared. The thermoplastic resins studied in this investigation exhibited lower measured values for the strength and elastic modulus properties than the light-polymerizing resin and the autopolymerizing polymethyl methacrylate resin studied.

  2. Technique for adapting a spacer for a custom impression tray.

    Science.gov (United States)

    Kaur, Harsimran; Nanda, Aditi; Verma, Mahesh; Koli, Dheeraj

    2016-12-01

    A method of adapting a spacer for the custom trays used to make a definite impression for complete dentures is presented. The technique can be used under a variety of conditions and offers several advantages.

  3. Changing the bonding force of impression tray to edentulous ...

    African Journals Online (AJOL)

    Key words: Bonding force, impression tray, maxillary jaw. Date of Acceptance: ... The purpose of complete dentures is to restore the dental and alveolar structures. ... A review of the literature revealed a lack of reports evaluating the pressure ...

  4. Tray Pack Improved Durability Packaging Rough Handling Test Results

    Science.gov (United States)

    1985-03-01

    extra vacuum void volume space makes these underfilled Tray Packs much more susceptible to damage. It is the vacuum that causes the damage not the under...filled to 6 lb. 10 oz. The result of underfilling is that the vacuum level in the peas is much higher making it more susceptible to paneling damage...impact. (3) That the vacuum induced by underfilling and vacuum pack- ing Tray Packs filled with peas makes them highly suscep- tible to damage. (4) That

  5. Prefabricated stock trays for impression of auricular region.

    Science.gov (United States)

    Vibha, Shetty; Anandkrishna, G N; Anupam, Purwar; Namratha, N

    2010-06-01

    The conventional methods of impression making for maxillofacial defects are cumbersome and time consuming for both patient and operator. This study focuses upon standardizing and simplifying the impression making methodology for auricular prosthesis with the help of prefabricated stock trays for auricular region. The stock trays were designed on positive replicas of anatomical structures, broadly divided into long and narrow, short and broad and long and broad ear. For each stock tray, impressions of auricle, of patients of different morphology were made with plastic funnels of different shape and size ensuring at least 6 mm of space between the anatomical part and inner surface of funnel and master cast was obtained. Subsequent adaptation of wax was done and fabrications of stock stainless steel trays were done. A standardized stock tray for making of auricular impressions was developed. From this innovative technical procedure it is possible to get an accurate impression of auricular defects now by the use of prefabricated stock trays rather than the cumbersome conventional method.

  6. Comparison of Dimensional Accuracy between Open-Tray and Closed-Tray Implant Impression Technique in 15° Angled Implants

    OpenAIRE

    Balouch F.; Jalalian E; Nikkheslat M.; Ghavamian R.; Toopchi Sh.; Jallalian F.; Jalalian S.

    2013-01-01

    Statement of Problem: Various impression techniques have different effects on the accuracy of final cast dimensions. Meanwhile; there are some controversies about the best technique. Purpose: This study was performed to compare two kinds of implant impression methods (open tray and closed tray) on 15 degree angled implants. Materials and Method: In this experimental study, a steel model with 8 cm in diameter and 3 cm in height were produced with 3 holes devised inside to stabilize 3 implants....

  7. A modified edentulous maxillary custom tray to help prevent gagging.

    Science.gov (United States)

    Callison, G M

    1989-07-01

    The gag reflex can be a normal, healthy defense mechanism to prevent foreign objects from entering the trachea. During certain dental procedures, however, gagging can greatly complicate the final result, especially during the maxillary complete denture final impression. A modification can be made to the maxillary custom acrylic resin tray to aid in securing a clinically acceptable elastomeric final impression. This modification involves forming a vacuum chamber at the posterior extent of the custom tray to which a saliva ejector tip is embedded. When the saliva ejector is connected to the low-volume evacuation hose, the chamber will trap any excess impression material that might extrude from the posterior border of the loaded tray. This results in a reduced chance of eliciting the patient's gag reflex.

  8. Time Domain Terahertz (T-Ray) Subsurface and Structural Imaging

    Science.gov (United States)

    Zimdars, David; White, Jeffrey S.; Stuk, G.; Chernovsky, A.; Fichter, G.; Sucha, G.; Williamson, S.

    2007-03-01

    The technology, methods, and examples of high speed time domain terahertz (T-Ray) imaging non-destructive examination (NDE) for 2 and 3 dimensional structural and material content characterization are discussed. T-Ray imaging can be utilized for non-contact transmission and/or monostatic reflection inspection of non-conductive materials such as plastics, foam, composites, ceramics, paper, wood and glass. Example subsurface homeland security images of concealed items in baggage and on personnel are shown. We tabulate attenuation and penetration characteristics through a selection of building materials, and demonstrate the ability of T-ray instrumentation to sub-surface image building structures such as wall framing and interior wiring and conduits.

  9. The accuracy of polyvinyl siloxane impressions made with standard and reinforced stock trays.

    Science.gov (United States)

    Wassell, R W; Ibbetson, R J

    1991-06-01

    A laboratory investigation was done to assess the influence of proprietary stock trays on the accuracy of impressions recorded with heavy light-body (HL) and putty light-body (PL) wash impression techniques. Two brands of trays were tested and the same trays were reinforced with acrylic resin. Individual die accuracy and overall distortion of the resultant casts were assessed. PL impressions in both stock trays gave undersized buccolingual dimensions at the preparation finishing lines whereas reinforcing the trays reduced this distortion. Significant inaccuracy at the second molar was found for all trays when PL impressions were made. These distortions would have resulted in clinically unacceptable dies. HL impressions, regardless of tray type, produced highly accurate dies at this critical site. Resultant overall cast distortion was reduced, but not eliminated, by using reinforced trays with either PL or HL techniques.

  10. Challenges to validation of a complex nonsterile medical device tray.

    Science.gov (United States)

    Prince, Daniel; Mastej, Jozef; Hoverman, Isabel; Chatterjee, Raja; Easton, Diana; Behzad, Daniela

    2014-01-01

    Validation by steam sterilization of reusable medical devices requires careful attention to many parameters that directly influence whether or not complete sterilization occurs. Complex implant/instrument tray systems have a variety of configurations and components. Geobacillus stearothermophilus biological indicators (BIs) are used in overkill cycles to to simulate worst case conditions and are intended to provide substantial sterilization assurance. Survival of G. stearothermophilus spores was linked to steam access and size of load in the chamber. By a small and reproducible margin, it was determined that placement of the trays in a rigid container into minimally loaded chambers were more difficult to completely sterilize than maximally loaded chambers.

  11. Modified Technique for Making Auto-polymerized Polymethylmethacrylate Resin Custom Tray

    OpenAIRE

    Chidambaranathan, Ahila Singaravel; Reddy, Ramesh; Rajendran, Suresh; Balasubramaniam, Muthu Kumar

    2016-01-01

    Custom made tray for dental impression is designed to provide a uniform space for the impression material and thereby improve the accuracy of the resultant working cast. Auto-polymerized acrylic resins have been the most commonly used material for the fabrication of these trays. The custom tray produces more accurate and reliable results for inter-abutment distance at the occlusal and gingival level than stock trays. This article describes a modified technique for fabrication of auto-polymeri...

  12. Training to Increase Safe Tray Carrying among Cocktail Servers

    Science.gov (United States)

    Scherrer, Megan D.; Wilder, David A.

    2008-01-01

    We evaluated the effects of training on proper carrying techniques among 3 cocktail servers to increase safe tray carrying on the job and reduce participants' risk of developing musculoskeletal disorders. As participants delivered drinks to their tables, their finger, arm, and neck positions were observed and recorded. Each participant received…

  13. Journal of EEA, Vol. 30, 2013 SIEVE TRAY EFFICIENCY USING ...

    African Journals Online (AJOL)

    dell

    that is the dominant separation process of the chemical and related ... separation but also are required in tray design to convert theoretical number ...... [14] Seader, J. D., Henley, E.J. and Roper, D.K.,. “Separation Process Principles: Chemical.

  14. Astronaut Norman Thagard changes tray in RAHF for rodents

    Science.gov (United States)

    1985-01-01

    Astronaut Norman Thagard changes a tray in the research animal holding facility (RAHF) for rodents at the Ames double rack facility aboard the Spacelab 3 science module in the cargo bay of the shuttle Challenger. Lending a hand is payload specialist Lodewijk van den Berg. Both men are wearing protective clothing and surgical masks for this procedure.

  15. Modified Technique for Making Auto-polymerized Polymethylmethacrylate Resin Custom Tray

    Science.gov (United States)

    Reddy, Ramesh; Rajendran, Suresh; Balasubramaniam, Muthu Kumar

    2016-01-01

    Custom made tray for dental impression is designed to provide a uniform space for the impression material and thereby improve the accuracy of the resultant working cast. Auto-polymerized acrylic resins have been the most commonly used material for the fabrication of these trays. The custom tray produces more accurate and reliable results for inter-abutment distance at the occlusal and gingival level than stock trays. This article describes a modified technique for fabrication of auto-polymerized Polymethylmethacrylate (PMMA) resin trays. PMID:28050525

  16. On-line Diagnosing on Trayed Column of Etylene Plant Using Gamma Ray Scanning

    Directory of Open Access Journals (Sweden)

    S. Sugiharto

    2012-12-01

    Full Text Available Nuclear based technology called gamma scanning technique found its application for troubleshooting and diagnosing industrial process performance. The success of application of the gamma scanning technique is attributed to its unique ability in providing information which is cannot be obtained by any other techniques. One of the most prominent advantages of the gamma scanning technique was demonstrated by implementing this technology for scanning caustic/water wash tower DA 202 which was running in normal condition of operation. The DA 202 tower is trayed column having diameter of 4.2 m and height of 40 m. The scanning work has been performed using 70 mCi 60Co isotope as gamma emitter and scintillation detector as radiation counter to investigate condition of ten trays, starting from tray # 13 at elevation of 35050 mm to tray # 4 at elevation of 26950 mm above ground level. Scan data show that all trays were in their position. Tray # 4 to tray #10 were functioned properly and carried approximately the same amount of liquid. Light flooding on tray # 11 and heavy flooding on tray # 12 were identified. Partial flooding was identified on tray # 13. Further examination at the time of shutdown it was found that the liquid flooding on tray # 12 was caused by presence of a bucket covered with solidified mud.

  17. Influence of tray geometry on scaling up distillation efficiency from laboratory data

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, F.; Castells, F. [Univ. Rovira i Virgili, Catalunya (Spain). Dept. of Chemical Engineering

    1999-07-01

    This paper studies the effect of tray geometry (especially hole diameter) and liquid tray composition on tray efficiency in a bench-scale distillation column. The results of this study are used for scaling up tray efficiency. Two binary systems, ethanol/water and cyclohexane/n-heptane, were considered. The operating conditions were atmospheric pressure and total reflux. For each one, two different hole diameters (small and large) were also tested. Kirschbaum`s industrial data (1962) for the ethanol/water system and of Yanagi and Sakata`s (1982) for the cyclohexane/n-heptane system were considered as reference values. The results show the importance of reproducing the hole diameter and liquid tray composition in small trays for using laboratory data to predict large tray efficiency.

  18. 75 FR 61521 - NUREG/CR-7010, Cable Heat Release, Ignition, and Spread in Tray Installations During Fire...

    Science.gov (United States)

    2010-10-05

    ... COMMISSION NUREG/CR-7010, Cable Heat Release, Ignition, and Spread in Tray Installations During Fire..., and Spread in Tray Installations During Fire (CHRISTIFIRE) Volume 1: Horizontal Trays, Draft Report... pdr.resource@nrc.gov . ``NUREG/CR-7010, Cable Heat Release, Ignition, and Spread in Tray Installations...

  19. Scientific Opinion on the safety assessment of the process “Petra Polimeri” used to recycle polypropylene trays and insert trays for use as food contact material

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-07-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the recycling process “Petra Polimeri”, EC register number RECYC089. The process recycles polypropylene (PP trays and inserts trays which have been used for the transport, storage and display of whole, fresh fruits and vegetables at room temperature or below. Trays are returned by consumers and collected in specific containers at the point of sale and insert trays originate from a closed loop of distributors. After collection, trays and insert trays are sorted separately. Through this process, sorted trays and/or insert trays are ground into flakes, which are washed, dried and extruded into granules. This recycled material is used up to 30 % with virgin PP to manufacture new trays and insert trays intended for transport, storage and display of whole, fresh fruits and vegetables. The Panel considered the specific use of the recycled trays and insert trays and the management of the input material as a critical process step. The Panel concluded that exposure of consumers to potential contaminants is unlikely and that the recycled PP obtained from the process Petra Polimeri is not of safety concern when i made with collected trays from specific containers at the point of sale along with a communication and/or insert trays from the retailer, trays and insert trays being collected and sorted separately; the sorting being positive and manual, and leading to more than 99.9 % PP trays and insert trays, and when ii intended to be used up to 30 % with virgin PP to manufacture new recycled trays and/or insert trays for contact with whole, fresh fruits and vegetables at room temperature or below.

  20. Sands styrke

    DEFF Research Database (Denmark)

    Jacobsen, H. Moust; Jørgensen, Mogens B.; Poulsen, H. Serup

    1975-01-01

    På grundlag af triaxialforsøg med D=7 og 20 cm og varierende højde på løse og faste lejringer af Blokhussand kan effekten af varierende højde-breddeforhold og spændingsniveau samt skalaeffekten bestemmes. Ved sammenligning med pladeforsøg med overfladelast op til 8 t/m2 kan den almindelige fremga...... fremgangsmåde ved bæreevneberegninger på sand undersøges....

  1. LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12

    Science.gov (United States)

    1984-01-01

    LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep Interplanetary Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six

  2. Accuracy of implant transfer with open-tray and closed-tray impression techniques and surface detail reproduction of the tooth during impression

    Directory of Open Access Journals (Sweden)

    Hakimeh Siadat

    2012-01-01

    Full Text Available Background and Aims: Accurate recording of implant location is required to achieve passive fit and have the implants without stress concentration. The aim of this in-vitro study was to evaluate the dimensional and angular accuracy of open-tray and closed-tray impression techniques using polyether impression material and also to assess the surface detail reproduction of the tooth while impression making.Materials and Methods: One reference metal model with 2 implants (Implantium on the position of the maxillary second premolar and first molar and one molar tooth for evaluation of surface details was prepared. 27 polyether impressions of these models were made (9 using open-tray, 9 using closed-tray techniques and 9 were made just of the surface of the teeth without any implants. Impressions were poured with ADA type IV stone. Coordinate Measuring Machine was used for measuring the dimensional accuracy and video measuring machine for surface detail reproduction. All of these measurements were compared with the measurements on the reference model. Data were analyzed by and compared by T-test and One-way ANOVA.Results: There was a significant statistical difference between open-tray and closed-tray techniques (P0.05.Conclusion: The accuracy of open-tray impression technique was more than closed-tray technique. The surface detail reproduction of the tooth was not affected by impression technique.

  3. Tar sand

    Energy Technology Data Exchange (ETDEWEB)

    McLendon, T.R.; Bartke, T.C.

    1990-01-01

    Research on tar sand is briefly discussed. The research program supported by the US Department of Energy (DOE) includes a variety of surface extraction schemes. The University of Utah has process development units (PDU) employing fluidized bed, hot, water-assisted, and fluidized-bed/heat-pipe, coupled combustor technology. Considerable process variable test data have been gathered on these systems: (1) a rotary kiln unit has been built recently; (2) solvent extraction processing is being examined; and (3) an advanced hydrogenation upgrading scheme (hydropyrolysis) has been developed. The University of Arkansas, in collaboration with Diversified Petroleum, Inc., has been working on a fatty acid, solvent extraction process. Oleic acid is the solvent/surfactant. Solvent is recovered by adjusting processing fluid concentrations to separate without expensive operations. Western Research Institute has a PDU-scale scheme called the Recycle Oil Pyrolysis and Extraction (ROPE) process, which combines solvent (hot recycle bitumen) and pyrolytic extraction. 14 refs., 19 figs.

  4. It's in the sand

    OpenAIRE

    Mitchell, Clive

    2016-01-01

    Sand is sand isn’t it? Sand gets everywhere but rather than a nuisance it is a valuable, high-purity raw material. Clive Mitchell, Industrial Minerals Specialist at the British Geological Survey (BGS), talks us through what sand is, what it can be used for and how to find it. His exploration of sand takes us from the deserts of Arabia to the damp sand pits of Mansfield!

  5. A Novel SiC Foam Valve Tray for Distillation Columns

    Institute of Scientific and Technical Information of China (English)

    张吕鸿; 刘学宽; 李鑫钢; 高鑫; 隋红; 张劲松; 杨振明; 田冲; 李洪

    2013-01-01

    The novel SiC foam valve tray was made of thin slices of SiC foam material with a high specific surface area. Hydrodynamic performances of the novel SiC foam valve tray were studied with air-water system at atmos-pheric pressure. These performance parameters included pressure drop, entrainment, weeping and clear liquid height. The mass transfer efficiency of the SiC foam valve tray was measured in laboratory plate column. Compared with the F1 float valve tray, the dry pressure drop was decreased about 25%, the entrainment rate was about 70%lower at high gas load, the weeping was much better, and the mass transfer efficiency was far higher. Thus, the overall performance of the novel SiC foam valve tray was better than that of F1 float valve tray.

  6. Transportation, handling, and microbial comparison of molded fiber and expanded polystyrene apple trays

    Science.gov (United States)

    Lussier, Mackenzie

    Washington Apples are shipped all over the United States for retail consumption. In order to survive the distribution cycle, the apples need adequate packaging to reduce damage. The two main materials used for the apple trays are expanded polystyrene (EPS) and molded fiber. An industrial switch from Molded Fiber to EPS trays provoked an interest in the difference between the two materials. Testing was required to conclude which tray material, if any, provided better protection for the apples. In order to determine the differences between the two trays, the physical and microbial characteristics were tested. The physical performance of the trays was tested through distribution, drop, and handling testing. A microbial analysis of the condensation was performed to determine the microbial protection that the trays offer. After performing a cost analysis, the EPS trays cost twice as much as the Molded Fiber trays. The testing proved that there is no difference in the physical and microbial protection that the two trays provide for the apples.

  7. In Vitro Comparative Evaluation of Different Types of Impression Trays and Impression Materials on the Accuracy of Open Tray Implant Impressions: A Pilot Study.

    Science.gov (United States)

    Gupta, Sonam; Narayan, Aparna Ichalangod; Balakrishnan, Dhanasekar

    2017-01-01

    Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique. Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n = 5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA. Results. Statistically significant difference (p materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p > 0.05) was observed between varied stock and custom trays. Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials.

  8. Industrial sand and gravel

    Science.gov (United States)

    Dolley, T.P.

    2013-01-01

    Domestic production of industrial sand and gravel in 2012 was about 49.5 Mt (55 million st), increasing 13 percent compared with that of 2011. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

  9. Dimensional stability ofautoclave sterilised addition cured impressions and trays.

    Science.gov (United States)

    Deb, S; Etemad-Shahidi, S; Millar, B J

    2014-03-01

    The aim of this study was to investigate the dimensional accuracy of impressions following sterilisation by autoclaving. Dental impressions (75) were of a dentoform containing 6 reference points. The impressions were split into 5 groups of 15, each group used a different impression technique. Groups were divided into 3 subgroups with 5 impressions as control, 5 for disinfection by Perform-ID and 5 being autoclaved. Measurements were made using a travelling light microscope. A minimal significant dimensional difference (0.01impression method. No significant dimensional differences were observed for all other groups (P>0.05). The trays and materials tested were suitable for the autoclave sterilisation.

  10. Three-dimensional simulation of liquid flow on a sieve tray under different inclinations

    Directory of Open Access Journals (Sweden)

    Zhang Ping

    2014-12-01

    Full Text Available The fluid state on a sieve tray will change when the towers tilt under wind loads. A computational fluid dynamics (CFD model was used to predict the flow patters and hydraulics on the tray under different inclinations. The gas and liquid phases are modelled with the volume-of-fluid (VOF framework as two inmiscible phases. Several three-dimensional transient simulations were carried out for a 0.38m diameter tray with varying liquid weir loads and inclined angles. The clear liquid height determined from these simulations is in reasonable agreement with experimental measurements carried out for air-water in a round tray of the same dimensions. The simulation results show that, compared with the horizontal tray, the circulation area is bigger when the liquid flow and inclination direction of the tray are the same, but when they are opposite the circulation area is smaller. The percentage of circulation area to the tray area can obviously be decreased, along with increasing liquid weir loads. It is concluded that CFD can be used for the prediction of liquid flow on sieve trays under different inclinations

  11. Eastern Scheldt Sand, Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

    The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...

  12. Biodegradable foam trays obtained from mixtures of non-irradiated and irradiated cassava starches

    Energy Technology Data Exchange (ETDEWEB)

    Brant, A.J.C.; Naime, N.; Lugao, A.B.; Ponce, P., E-mail: thonybrant@gmail.com, E-mail: patiponce@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Biodegradable polymers, such as starch, cellulose, PHB, PLA, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging by extrusion-thermopressing process. Their formulations were based on non-irradiated and γ-irradiated starches at diverse radiation absorbed doses (kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose: 26.32% and 39.84% for the trays based on starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively. Other physicochemical properties were evaluated from the starches utilized and the trays obtained. (author)

  13. Application of FDM three-dimensional printing technology in the digital manufacture of custom edentulous mandible trays

    OpenAIRE

    Hu Chen; Xu Yang; Litong Chen; Yong Wang; Yuchun Sun

    2016-01-01

    The objective was to establish and evaluate a method for manufacture of custom trays for edentulous jaws using computer aided design and fused deposition modeling (FDM) technologies. A digital method for design the custom trays for edentulous jaws was established. The tissue surface data of ten standard mandibular edentulous plaster models, which was used to design the digital custom tray in a reverse engineering software, were obtained using a 3D scanner. The designed tray was printed by a 3...

  14. The Analysis of Distillation Tray Column Efficiency by Fluid Dynamics and Mass Transfer Computation

    Institute of Scientific and Technical Information of China (English)

    刘春江; 袁希钢; 余国琮

    2005-01-01

    It has long been found that the flow pattern of the liquid phase on distillation tray is of great importance on distillation process performance. But until now, there was very few published work on quantitative investigation of this subject. By combining the computational fluid dynamics (CFD) with the mass transfer equation, a theoretical model is proposed for predicting the details of velocity and concentration distributions as well as the tray efficiency of distillation tray column. Using the proposed model, four different cases corresponding to different assumptions of liquid and vapor flowing condition for a distillation tray column were investigated. In Case I, the distributions of velocity and concentration of the incoming liquid from the downcomer and the uprising vapor from the underneath tray spacing are uniform. In Case Ⅱ, the distribution of the incoming liquid is non-uniform but the uprising vapor is uniform. In Case Ⅲ, the distribution of the incoming liquid is uniform but the uprising vapor is non-uniform.In Case IV, the distributions of both the incoming liquid and the uprising vapor are non-uniform. The details of velocity and concentration distributions on a multiple sieve tray distillation column in four different cases were simulated using the proposed model. It is found that the shape of the simulated concentration profiles of vapor and the liquid is quite different from case to case. The computed results also show that the tray efficiency is highly reduced by the maldistribution of velocity and concentration of the incoming liquid and uprising vapor. The tray efficiency for Case Ⅰ is higher than Case Ⅱ or Case Ⅲ, and that for Case Ⅳis the lowest. It also reveals that the accumulated effect of maldistribution becomes more pronounced when the number of column trays increased. The present study demonstrates that the use of computational method to predict the mass transfer efficiency for the tray column, especially for the large one, is

  15. Influence green sand system by core sand additions

    OpenAIRE

    N. Špirutová; J. Beňo; V. Bednářová; J. Kříž; M. Kandrnál

    2012-01-01

    Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron) are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this co...

  16. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Borup, Marianne; Hedegaard, Jette

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development og the theory of building up pore pressure in sand, L. B. Ibsen 1993....

  17. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...

  18. A distillation tray with high efficiency and excellent operating flexibility for viscous mixture separation

    Directory of Open Access Journals (Sweden)

    Li Qunsheng

    2014-01-01

    Full Text Available The flow-guided sieve-valve tray(FGS-VTwith high efficiency was designed to overcome the shortcoming of low operating flexibility of the flow-guided sieve tray. Its dimensions and geometry, as well as structure characteristics, were presented. The hydrodynamics and mass transfer performance, including dry-plate pressure drop, wet plate-pressure drop, weeping, entrainment and tray efficiency, of two types of FGS-VTs (FGS-VTs with 14 and 8 valves, respectively and one flow-guided sieve tray were tested in an air-water-oxygen cold model experiment with a 0.6 m diameter plexiglass column. The results demonstrate that FGS-VT with 14 valves works better than FGS-VT with 8 valves, and in comparison with the flow-guided sieve tray, the flow-guided sieve-valve tray with 14 valves has higher tray efficiency, bigger operating flexibility, and lower wet-plate pressure drop (when all the valves are opened fully.Additionally, two typical applications to separate the mixture with high viscosity, solid, powder, easy-to-foam or easy self-polymerization components proved the unique advantages of FGS-VT.

  19. Application of FDM three-dimensional printing technology in the digital manufacture of custom edentulous mandible trays.

    Science.gov (United States)

    Chen, Hu; Yang, Xu; Chen, Litong; Wang, Yong; Sun, Yuchun

    2016-01-14

    The objective was to establish and evaluate a method for manufacture of custom trays for edentulous jaws using computer aided design and fused deposition modeling (FDM) technologies. A digital method for design the custom trays for edentulous jaws was established. The tissue surface data of ten standard mandibular edentulous plaster models, which was used to design the digital custom tray in a reverse engineering software, were obtained using a 3D scanner. The designed tray was printed by a 3D FDM printing device. Another ten hand-made custom trays were produced as control. The 3-dimentional surface data of models and custom trays was scanned to evaluate the accuracy of reserved impression space, while the difference between digitally made trays and hand-made trays were analyzed. The digitally made custom trays achieved a good matching with the mandibular model, showing higher accuracy than the hand-made ones. There was no significant difference of the reserved space between different models and its matched digitally made trays. With 3D scanning, CAD and FDM technology, an efficient method of custom tray production was established, which achieved a high reproducibility and accuracy.

  20. Early tibial tray failure of a Duracon knee with retrieval analysis.

    Science.gov (United States)

    Ho, Ta-Feng; Tsai, Ruey-Yug; Lee, Pei-Yuan; Ku, Ming-Chou

    2004-09-01

    We report a case of early tibial tray fracture of a Duracon knee prosthesis. Aside from the clinical, radiographic, and gross analysis of the failed prosthesis, we also performed analysis on the retrieved polyethylene component and the fractured tibial baseplate. In the analyses, we noted significant femoral component malalignment, uneven tray cementation, and inherent metallurgical weakness. It appears that the high compressive load on the medial tray resulted in bending fatigue failure. To avoid this complication, it is important to restore the normal alignment of the knee joint and use a polyethylene insert of higher conformity, at least 6 mm thick.

  1. Dimensional accuracy of 2-stage putty-wash impressions: influence of impression trays and viscosity.

    Science.gov (United States)

    Balkenhol, Markus; Ferger, Paul; Wöstmann, Bernd

    2007-01-01

    The aim of this in vitro study was to evaluate the influence of the impression tray and viscosity of the wash material on the dimensional accuracy of impressions taken using a 2-stage putty-wash technique. Identically shaped metal stock trays (MeTs) and disposable plastic stock trays (DiTs) were used for taking impressions (n = 10) of a mandibular cast (4 abutments) with 2 different impression materials. Dies were poured and the relative diameter deviation was calculated after measurement. Zero viscosity of the materials was determined. Dimensional accuracy was significantly affected when DiTs were used. Lower-viscosity wash materials led to more precise impressions.

  2. Design, Development and Evaluation of a Pneumatic Seeder for Automatic Planting of Seeds in Cellular Trays

    Directory of Open Access Journals (Sweden)

    E Movahedi

    2014-04-01

    Full Text Available For planting fine seeds in cellular trays, an automatic pneumatic seeder was designed, constructed and evaluated. CATIA software was used to design and analysis the system parts of the seeder. Different parts of the seeder, including vibrating seed hopper, vacuum boom, seed picking nozzles, seed tube, pneumatic system and electronic control unit for automation of the seeder, were designed and constructed. The area of nozzle orifice was used to calculate the required pressure of nozzle tip. The seeder was evaluated using two sizes of trays. Experiments were performed with five replications and the error of planting the seeds in the 105 and 390-cellular trays were 1.9 and 0.46 percent, respectively. The time of planting for 105 and 390 cellular trays reduced from 20 min (for manual seeding to 35 s and from 90 min to 160 s, respectively.

  3. Hydrodynamic and mass transfer characteristics of distillation trays with trapezoidal valves

    Energy Technology Data Exchange (ETDEWEB)

    Berkovskii, M.A.; Lebedev, Yu.N.; Pil' ch, L.M.; Sheinman, V.A.; Vikhman, A.G.

    1983-01-01

    The ''TK'' tray was investigated in a ''cold'' test stand with a rectangular cross section (300 x 800 mm) on a water/air system and in a ''hot'' test stand with a circular cross section (1200 mm diameter) on a toluene/o-xylene system. The results obtained in these studies demonstrate the desirability of using TK trays in industry. The trays are simple in design, and there is practically no waste in fabricating the trays; hence, the reconstruction of towers can be handled by the refinery work force. An annual economic advantage of 300,000 rubles from reconstruction is predicted.

  4. Assessment of TAMU Rack Material in Poly Tray Racks using Spray Retort

    Science.gov (United States)

    2009-07-01

    necessary perforated plates for their production retort pallets to support the racks in all the load bearing points, temperature distribution were...Characterization New Rack – Loaded with Polymeric Half Steam Table Tray – One Pallet Retorted @ 260 F for 60 min (2 times) – Test for Rack Sag – Drop Test – 2...dimension and weight. Rutgers will supply adequate number of polymeric trays for this test. A single pallet load will be retorted at 260 F for 60

  5. Combat Ration Network for Technology Implementation. Retort Racks for Polymeric Trays in 1400 Style Spray Retorts

    Science.gov (United States)

    2003-05-01

    trays backup plate & support pillars to allow 35" shut height as required by most 3500 ton molding machines dedicated mounting rails for installation...hr. At this time, Stegner had modified all their pallet bottom plates to support the rack in all load bearing points and in addition, Wornick send two...COMBAT RATION NETWORK FOR TECHNOLOGY IMPLEMENTATION Retort Racks for Polymeric Trays in 1400 Style Spray Retorts Final Technical Report STP 2010

  6. Bactericidal paper trays doped with silver nanoparticles for egg storing applications

    Indian Academy of Sciences (India)

    KALIYAPERUMAL VISWANATHAN; M LATHA MALA PRIYADHARSHINI; KARUPPASAMY NIRMALA; MUTHUSAMY RAMAN; GOPAL DHINAKAR RAJ

    2016-06-01

    In this study, a cost-effective way to deposit the silver nanoparticles (AgNPs) on paper egg trays was developed, which proved suitable for prolonged storage of table eggs for house-hold use without deterioration of egg quality. Silver nanoparticles were synthesized based on chemical reduction approach and mixed with gelatin–chitosan mixer used as a colloidal stabilizer as well as fixing agent. AgNPs-doped paper egg trays were characterized by TEM, SEM, FTIR, EDX and XRD. AgNPs containing egg trays were tested for its bactericidal effect against commonly found bacteria on egg shells, E. coli, S. aureus, Streptococcus spp and Salmonella spp. Storing of eggs in the AgNPs-deposited paper egg trays improved the shelf-life of the eggs by more than 14 days compared to controls (eggs stored in conventional trays). In conclusion, the developed paper trays possessed strong antimicrobial activity and it could be an effective storage material for eggs.

  7. Influence green sand system by core sand additions

    Directory of Open Access Journals (Sweden)

    N. Špirutová

    2012-01-01

    Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

  8. Sands cykliske styrke

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    1992-01-01

    Sands cykliske styrke kan beskrives ved Cyclic Liquefaction, Mobilisering, Stabilization og Instant Stabilization. I artiklen beskrives hvorfor Stabilization og Instant Stabilization ikke observeres, når sands udrænede styrke undersøges i triaxial celler, der anvender prøver med dobbelt prøvehøjde....

  9. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Bødker, Lars Bødker

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...

  10. Biodegradable PLA (polylactic acid) hinged trays keep quality of fresh-cut and cooked spinach.

    Science.gov (United States)

    Botondi, Rinaldo; Bartoloni, Serena; Baccelloni, Simone; Mencarelli, Fabio

    2015-09-01

    This work examines the effects of packaging using two different polymeric trays with hinged lids, polyethylene terephthalate (PET) and polylactic acid (PLA), on fresh-cut and cooked spinach (Spinacia oleracea). Samples were stored in a cold room for 16 days at 4 °C. Chemical (total pigments, total polyphenols, ascorbic acid, antioxidant activity), physical (water activity), technological (colour evaluation), sensorial (aroma, visual appearance and water accumulation) and microbial (total aerobic mesophilic and psychrotrophic counts) parameters were tested. Both polymeric trays maintained the overall quality of fresh spinach for 6 days but spinach stored in PLA trays maintained its flavour longer. A significant increase in total polyphenols, antiradical activity, total carotenoids as well as a decrease in ascorbic acid in fresh spinach was observed in the first 3 days of storage in both samples. Unfortunately, the PLA package accumulated condensed water. The total microbial load of fresh-cut spinach reached about 6.3-7.3 log CFU g(-1) within 8 days. Cooked spinach packed in PLA and PET polymeric hinged trays showed the same behaviour as fresh spinach in terms of quality and shelf life. In conclusion, PLA plastic hinged trays can be used for packaging fresh-cut and cooked cut spinach, but the problem of condensed water must be solved.

  11. LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    Science.gov (United States)

    1990-01-01

    LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00266 LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The experiment is shown in the postflight configuration before closing the canisters with ground support equipment that bypassed the experiments onboard electronics circuitry. Three full panels and approximately 3/4th of the other panel are covered with gold foil (>99.99 percent pure). The remaining area on the fourth panel is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. A brown stain is visible on the experiment tray flanges, however, most of the stains observed in the flight photograph are obscured by reflected light. All materials remain intact with no visual evidence of damage to the experiment. The reflection of a video camera on a tripod and light sources can be seen on the gold foil covered panels. The experiment canisters are shown after being closed by using the experiments ground support equipment. The stain buildup can be clearly seen at the vertical center of the right tray flange. The clean area was located under the experiment tray clamp block and was not exposed to the staining medium. The stain also coats other areas that were exposed during the mission but are not as noticeable. The experiment hardware seems to be intact and have no damage.

  12. Surgical instrument similarity metrics and tray analysis for multi-sensor instrument identification

    Science.gov (United States)

    Glaser, Bernhard; Schellenberg, Tobias; Franke, Stefan; Dänzer, Stefan; Neumuth, Thomas

    2015-03-01

    A robust identification of the instrument currently used by the surgeon is crucial for the automatic modeling and analysis of surgical procedures. Various approaches for intra-operative surgical instrument identification have been presented, mostly based on radio-frequency identification (RFID) or endoscopic video analysis. A novel approach is to identify the instruments on the instrument table of the scrub nurse with a combination of video and weight information. In a previous article, we successfully followed this approach and applied it to multiple instances of an ear, nose and throat (ENT) procedure and the surgical tray used therein. In this article, we present a metric for the suitability of the instruments of a surgical tray for identification by video and weight analysis and apply it to twelve trays of four different surgical domains (abdominal surgery, neurosurgery, orthopedics and urology). The used trays were digitized at the central sterile services department of the hospital. The results illustrate that surgical trays differ in their suitability for the approach. In general, additional weight information can significantly contribute to the successful identification of surgical instruments. Additionally, for ten different surgical instruments, ten exemplars of each instrument were tested for their weight differences. The samples indicate high weight variability in instruments with identical brand and model number. The results present a new metric for approaches aiming towards intra-operative surgical instrument detection and imply consequences for algorithms exploiting video and weight information for identification purposes.

  13. Test-based approach to cable tray support system analysis and design: Behavior and test methods

    Energy Technology Data Exchange (ETDEWEB)

    Reigles, Damon G., E-mail: dreigles@engnovex.com [engNoveX, Inc., 19C Trolley Square, Wilmington, DE 19806 (United States); Brachmann, Ingo; Johnson, William H. [Bechtel Nuclear, Security & Environmental, 12011 Sunset Hills Rd, Suite 110, Reston, VA 20190 (United States); Gürbüz, Orhan [Tobolski Watkins Engineering, Inc., 4125 Sorrento Valley Blvd, Suite B, San Diego, CA 92121 (United States)

    2016-06-15

    Highlights: • Describes dynamic response behavior of unistrut type cable tray supports. • Summarizes observations from past full-scale shake table test programs. • Outlines testing methodologies necessary to identify key system parameters. - Abstract: Nuclear power plant safety-related cable tray support systems subjected to seismic loadings were originally understood and designed to behave as linear elastic systems. This behavioral paradigm persisted until the early 1980s when, due to evolution of regulatory criteria, some as-installed systems needed to be qualified to higher seismic motions than originally designed for. This requirement prompted a more in-depth consideration of the true seismic response behavior of support systems. Several utilities initiated extensive test programs, which demonstrated that trapeze strut-type cable tray support systems exhibited inelastic and nonlinear response behaviors with plastic hinging at the connections together with high damping due to bouncing of cables in the trays. These observations were used to demonstrate and justify the seismic adequacy of the aforementioned as-installed systems. However, no formalized design methodology or criteria were ever established to facilitate use of these test data for future evaluations. This paper assimilates and reviews the various test data and conclusions for the purpose of developing a design methodology for the seismic qualification of safety-related cable tray support systems.

  14. Sand and Gravel Deposits

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is a statewide polygon coverage of sand, gravel, and stone resources. This database includes the best data available from the VT Agency of Natural...

  15. Sand and Gravel Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes sand and gravel operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate...

  16. Polylactic acid trays for fresh-food packaging: A Carbon Footprint assessment.

    Science.gov (United States)

    Ingrao, Carlo; Tricase, Caterina; Cholewa-Wójcik, Agnieszka; Kawecka, Agnieszka; Rana, Roberto; Siracusa, Valentina

    2015-12-15

    This paper discusses application of Carbon Footprint (CF) for quantification of the 100-year Global Warming Potential (GWP100) associated with the life cycle of polylactic acid (PLA) trays for packaging of fresh foods. A comparison with polystyrene (PS)-based trays was done considering two different transport system scenarios for PLA-granule supply to the tray production firm: a transoceanic freight vessel and an intercontinental freight aircraft. Doing so enabled estimation of the influence of the transportation phase on the GHG-emission rate associated with the PLA-trays' life cycle. From the assessment, the GWP100 resulted to be mainly due to PLA-granulate production and to its transportation to the tray manufacturing facility. Also, the study documented that, depending upon the transport system considered, the CF associated with the life cycle of the PLA trays can worsen so much that the latter are no longer GHG-emission saving as they are expected to be compared to the PS ones. Therefore, based upon the findings of the study, it was possible for the authors to understand the importance and the need of accounting for the transport-related issues in the design of PLA-based products, thus preserving their environmental soundness compared to traditional petroleum-based products. In this context, the study could be used as the base to reconsider the merits of PLA usage for product manufacturing, especially when high distances are implied, as in this analysed case. So, the authors believe that new research and policy frameworks should be designed and implemented for both development and promotion of more globally sustainable options.

  17. Vestled - Hvide Sande

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten; Hesselbjerg, Marianne; Schønherr, Torben

    2009-01-01

    Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side......Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side...

  18. Production of diosgenin from Dioscorea zingiberensis with mixed culture in a new tray bioreactor

    Directory of Open Access Journals (Sweden)

    Yutong Cheng

    2016-01-01

    Full Text Available A new tray bioreactor was developed for the production of diosgenin from Dioscorea zingiberensis with Trichoderma reesei and Aspergillus fumigatus. The influence of initial moisture content, temperature, tray bed depth and mixing times was investigated. The best fermentation condition is initial moisture content of 75%, bioreactor temperature of 35°C, solid bed depth of 1.5 cm and three mixings carrying out on the first, third and fifth day. Under the optimized fermentation conditions, after 144 h incubation, maximum diogenin concentration of 68.2 μmol/g was detected.

  19. Identification and Modeling of Froth to Spray Transition on Sieve Trays

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simulator with 300mm diameter. It has been found that the regime transition occurs as the clear liquid height is equal to the residual pressure drop on the trays. A convenient and accurate technique was proposed for determination of the regime transition point. Based on analysis of the transition process at a sieve hole, a new formula which can be used to correlate the experimental results was provided.

  20. Staphylococci in canine urolithiasis: species identification, using a commercially available tray micromethod.

    Science.gov (United States)

    Case, L C; Ling, G V; Biberstein, E L; Ruby, A L; Jang, S S

    1985-01-01

    Fifty-one coagulase-positive staphylococcal isolates from canine urinary calculi or from the urine of dogs with documented urolithiasis, and 17 coagulase-positive staphylococcal isolates from human beings and cattle were identified by a commercially available tray micromethod, as well as by conventional methods. Canine isolates had previously been classified as Staphylococcus aureus on the basis of a positive tube coagulase test. After 5 hours' incubation, the tray method identified all 51 canine urolithiasis isolates as S intermedius, rather than S aureus. All human and bovine isolates were identified as S aureus. Conventional methods supported these findings.

  1. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

    Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

  2. [The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement].

    Science.gov (United States)

    García David, S; Cortijo Martínez, J A; Navarro Bermúdez, I; Maculé, F; Hinarejos, P; Puig-Verdié, L; Monllau, J C; Hernández Hermoso, J A

    2014-01-01

    The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  3. Bituminous sands : tax issues

    Energy Technology Data Exchange (ETDEWEB)

    Patel, B. [PricewaterhouseCoopers LLP, Calgary, AB (Canada)

    2004-07-01

    This paper examined some of the tax issues associated with the production of bitumen or synthetic crude oil from oil sands. The oil sands deposits in Alberta are gaining more attention as the supplies of conventional oil in Canada decline. The oil sands reserves located in the Athabasca, Cold Lake and Peace River areas contain about 2.5 trillion barrels of highly viscous hydrocarbons called bitumen, of which nearly 315 billion barrels are recoverable with current technology. The extraction method varies for each geographic area, and even within zones and reservoirs. The two most common extraction methods are surface mining and in-situ extraction such as cyclic steam stimulation (CSS); low pressure steam flood; pressure cycle steam drive; steam assisted gravity drainage (SAGD); hot water flooding; and, fire flood. This paper also discussed the following general tax issues: bituminous sands definition; bituminous sands leases and Canadian development expense versus Canadian oil and gas property expense (COGPE); Canadian exploration expense (CEE) for surface mining versus in-situ methods; additional capital cost allowance; and, scientific research and experimental development (SR and ED). 15 refs.

  4. An Innovative Rigid Tray Technique for Replacement and Reattachment of the Anterior Composite Tooth Pontic

    Directory of Open Access Journals (Sweden)

    Saied Mostafa Moazzami

    2014-06-01

    Full Text Available Replacement and reattachment of a newly detached composite tooth pontic is sometimes justified because of shape, color, function and patient satisfaction. The aim of this case report is to describe a new method using Rigid Tray Technique for exact replacement and reattachment of acceptable detached composite tooth pontic

  5. Custom sectional impression trays with interlocking type handle for microstomia patients

    OpenAIRE

    Fernandes Aquaviva; Mascarenhas Kennedy; Aras Meena

    2009-01-01

    Making impressions in microstomia patients is often cumbersome. A modification of standard impression procedure is often necessary while treating such patients. This article describes the fabrication of a custom sectional impression tray with interlocking type of a handle for definitive impression procedures in a microstomia patient.

  6. Custom sectional impression trays with interlocking type handle for microstomia patients

    Directory of Open Access Journals (Sweden)

    Fernandes Aquaviva

    2009-01-01

    Full Text Available Making impressions in microstomia patients is often cumbersome. A modification of standard impression procedure is often necessary while treating such patients. This article describes the fabrication of a custom sectional impression tray with interlocking type of a handle for definitive impression procedures in a microstomia patient.

  7. Custom sectional impression trays with interlocking type handle for microstomia patients.

    Science.gov (United States)

    Fernandes, Aquaviva S; Mascarenhas, Kennedy; Aras, Meena A

    2009-01-01

    Making impressions in microstomia patients is often cumbersome. A modification of standard impression procedure is often necessary while treating such patients. This article describes the fabrication of a custom sectional impression tray with interlocking type of a handle for definitive impression procedures in a microstomia patient.

  8. LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    Science.gov (United States)

    1990-01-01

    LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00680 LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The flight photograph was taken with the LDEF on the Orbiter's RMS arm prior to berthing the spacecraft in the cargo bay. The canisters are in their open condition (they were expected to open about two (2) weeks after launch and close about eleven (11) months into the mission) with three (3) full panels and 3/4th of the fourth panel covered with a highly reflective gold foil (>99.99 percent pure).The remaining area is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. The exposed fasteners are non-magnetic stainless steel. All of the exposed materials seem to be secure and no damage is evident. The contamination stain that has changed the white paint dot on the tray clamp blocks to brown also coats the tray flanges and the aluminum canister hardware. The end support beam scuff plate in the photograph was a bright yellow prior to launch but is a much darker, mustard yellow after the space exposure.

  9. Mechanical properties of trays based on starch of native plant species and fiber of agroindustrial wastes

    Directory of Open Access Journals (Sweden)

    Miguel Espina

    2016-07-01

    Full Text Available The aim of this study was to evaluate the effect of natural fibers derived from agro-industrial waste in density, weight and mechanical properties of the termoprensadas foams made of starch native species, such as sweet potatoes, oca and arracacha. The thermoforming process was carried out at a temperature of 145 ° C and a pressure of 60 bar. The baking time was 10-15 min depending on water content in the mixture. The trays were characterized by their density, weight, impact test, deflection tests, colorimetry, hardness, and fracturability values. The trays prepared by thermopressure based on sweet potato starch-bagasse fiber from sugar cane at 15%, and arracacha starch -peladilla asparagus fiber at 30% had higher values in flexural strength versus those made with other types of starches and fibers, including blank tests. Generally, the hardness of the trays is favored with increasing fiber, however fracturability decreases or does not improve the integrity of the polymeric matrix. The results shown in this study allow the preparation of biodegradable trays for various industrial applications.

  10. Dynamic behaviour of reactive distillation tray columns described with a non-equilibrium cell model

    NARCIS (Netherlands)

    Baur, R.; Taylor, R.; Krishna, R.

    2001-01-01

    In this paper we develop a generic, dynamic, nonequilibrium (NEQ) cell model for reactive distillation (RD) tray columns. The features of our model are (1) the use of Maxwell–Stefan equations for describing mass transfer between fluid phases, (2) the reaction is assumed to take place in the liquid

  11. Salivary retention after application of fluoride gel using toothbrush or tray: a crossover trial.

    Science.gov (United States)

    Ribeiro, Cecilia Claudia Costa; Lula, Estevam Carlos de Oliveira; Azevedo, Izabelle Maria Cabral de; Maia, Mariana de Figueiredo Lopes E; Lopes, Fernanda Ferreira

    2012-01-01

    Currently, there are no studies in the literature evaluating salivary fluoride retention after small amounts of fluoride gel are applied to children's teeth. Therefore, the objective of the present study was to compare salivary retention after gel application using a toothbrush or by traditional application with trays. In this crossover study, children with active caries (n = 10) were randomized into one of the following treatment groups: a) application of fluoride gel using a tray (control), or b) application of fluoride gel with a toothbrush (treatment). After a 7-day washout period, the treatments were inverted. Unstimulated saliva samples were collected at baseline and 0.5, 5, 15, 30, 60 and 120 minutes after acidulated phosphate fluoride (APF) gel application in order to analyze fluoride retention in saliva. The area under the curve (AUC) was also calculated. There were no differences in fluoride retention after application of small amounts of APF with a toothbrush compared to traditional gel application using trays at all time points studied, and no differences in AUC were observed (Student t-test, p > 0.05). These results suggest that application of fluoride gel in children using a toothbrush can be utilized as an option rather than traditional trays, since the same salivary retention of fluoride is obtained using a lower dose.

  12. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...... test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. The Danish Triaxial Cell prescribes smooth pressure heads and specimens with equal height and diameter....... Four series with Id equal to 0.92, 0.87 0.76 and 0.55 have been performed....

  13. UK Frac Sand Resources

    OpenAIRE

    Mitchell, C J

    2015-01-01

    Although still just a glimmer in the gas man’s eye, the prospect of shale hydrocarbon (oil and gas) development in the UK has many companies thinking about the industrial minerals it will require. Chief amongst these is silica sand which is used as a ‘proppant’ in the hydraulic fracturing, or ‘fracking’, of shales to help release the gas. The UK has large resources of sand and sandstone, of which only a small proportion have the necessary technical properties that classify them as ‘silica san...

  14. Comparative evaluation of the accuracy of pick up transfer impressions performed with two different types of trays

    Directory of Open Access Journals (Sweden)

    Aline Treml

    2013-06-01

    Full Text Available Introduction: The success of implant-supported prostheses is related to the passive union between the prostheses’ connections and the implants, so it is necessary to obtain an accurate working cast. Objective: To evaluate the accuracy of the transfer impressions of implants performed with individual acrylic resin trays and conventional trays using polyvinyl siloxane. Material and methods: To carry out the transfer impressions, a master cast with four external hexagon implants parallel to each other was used. Five impressions were made with individual acrylic resin trays and five other impressions with modified conventional trays, opened in the region of the implants. The linear measurements between the implants were made with a digital caliper with an accuracy of 0.01 mm and the results were statistically evaluated (alpha = 5%. Results: For the points AB and BC, the measurements obtained with the individual trays were statistically similar to the master cast. For the points CD and DA no statistical differences among the three groups were observed. Conclusion: Given the obtained results and the methodology used, it can be concluded that the impressions performed with individual trays presented higher accuracy compared to the ones obtained with conventional trays.

  15. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  16. Faraday, Jets, and Sand

    NARCIS (Netherlands)

    Sandtke, M.; van der Meer, Roger M.; Versluis, Andreas Michel; Lohse, Detlef

    2003-01-01

    When a 6-mm layer of fine sand with an average grain size of 40 µm is poured into a cylindrical container and shaken vertically, thin jets are seen to emerge from an airy cloud of grains, almost like protuberances from the corona of the sun. A quasi two-dimensional setup reveals the jet-formation

  17. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  18. Speleothems and Sand Castles

    Science.gov (United States)

    Hance, Trevor; Befus, Kevin

    2015-01-01

    The idea of building sand castles evokes images of lazy summer days at the beach, listening to waves crash, enjoying salty breezes, and just unplugging for a while to let our inner child explore the wonderful natural toys beneath our feet. The idea of exploring caves might evoke feelings and images of claustrophobia or pioneers and Native…

  19. Virksomhedens sande ansigt

    DEFF Research Database (Denmark)

    Lundholt, Marianne Wolff

    2017-01-01

    Er modhistorier en byrde eller en styrke i forandringsprocesser? Hvad stiller vi op, når adgangen til organisationens sande identitet går gennem medarbejdernes modhistorier? Når vi sammenholder denne erkendelse med vores viden om, at medarbejdere helt naturligt afholder sig fra at videregive disse...

  20. Sand (CSW4)

    CSIR Research Space (South Africa)

    Estuarine and Coastal Research Unit

    1982-12-01

    Full Text Available This report is one of a series on Cape Estuaries being published under the general title "The Estuaries of the Cape, Part 2". The report provides information on sand estuary: historical background, abiotic and biotic characteristics. It is pointed...

  1. Sand supply to beaches

    Science.gov (United States)

    Aagaard, Troels

    2017-04-01

    In most cases, beaches and dunes are built by sand that has been transported onshore from the shoreface. While this has been known for a long time, we are still not able to quantitatively predict onshore sediment transport and sand supply to beaches. Sediment transport processes operating during brief, high-energy stormy conditions - when beaches erode and sand moves offshore - are fairly well known and they can be modelled with a reasonable degree of confidence. However, the slower onshore sand transport leading to beach recovery under low-to-moderate energy conditions - and the reason why beaches and dunes exist in the first place - is not yet well understood. This severely limits our capability to understand and predict coastal behaviour on long time scales, for example in response to changing sea level or wave conditions. This paper will discuss issues and recent developments in sediment transport measurement and prediction on the lower and upper shoreface and into the swash zone. The focus will be on the integration and upscaling of small-scale deterministic process measurements into parametric models that may increase modelling capabilities of coastal behaviour on larger temporal and spatial scales.

  2. Erosion phenomena in sand moulds

    Directory of Open Access Journals (Sweden)

    A. Chojecki

    2008-03-01

    Full Text Available Authors studicd the erosion phcnorncna in sand moulds pured with cast iron. Thc study comprises an evaluation of erosionresistance of thc three sands: grccn sand. sand bondcd with inorganic or organic bindcr. It was concluded that thc most resistant is [heclassic green sand with thc addition of 5 B coal dust. Resistance of the sand with organic binder is generally weak and dcvnds onkind of used raisin. Spccinl nztcntion was paid to the sands with no organic bindcr watcr glass and phospha~c. It was Sound that thcirrcsistance depends on dehydratation conditions. When the mould is stored in law humidity of atmosphcrc the very strong crosion canbe expected. It rcsul ts hrn thc micro fractures in the bridges of binders, joining the grains of the sable. This phcnomcna facilitates thetearing away of fragments of sand [tom the surface

  3. A comparative study of inter-abutment distance of dies made from full arch dual-arch impression trays with those made from full arch stock trays: An in vitro study

    Directory of Open Access Journals (Sweden)

    Reddy Jagan

    2009-01-01

    Full Text Available Objectives: The dual-arch impression technique is convenient in that it makes the required maxillary and mandibular impressions, as well as the inter-occlusal record in one procedure. The accuracy of inter-abutment distance in dies fabricated from dual-arch impression technique remains in question because there is little information available in the literature. Materials and Methods: This study was conducted to evaluate the accuracy of inter-abutment distance in dies obtained from full arch dual-arch trays with those obtained from full arch stock metal trays. Results and Conclusion: The metal dual-arch trays showed better accuracy followed by the plastic dual-arch and stock dentulous trays, respectively, though statistically insignificant. The pouring sequence did not have any effect on the inter-abutment distance statistically, though pouring the non-working side of the dual-arch impression first showed better accuracy.

  4. On Pluvial Compaction of Sand

    DEFF Research Database (Denmark)

    Jacobsen, Moust

    At the Institute of Civil Engineering in Aalborg model tests on dry sand specimens have been carried out during the last five years. To reduce deviations in test results, the sand laying technique has been carefully studied, and the sand mass spreader constructed. Preliminary results have been...

  5. Moral Education through Play Therapy

    Science.gov (United States)

    Mahalle, Salwa; Zakaria, Gamal Abdul Nasir; Nawi, Aliff

    2014-01-01

    This paper will discuss on how sand therapy (as one type of play therapies) can be applied as an additional technique or approach in counseling. The research questions for this study are to see what are the development, challenges faced by the therapist during the sessions given and how sand therapy can aid to the progress of the client. It is a…

  6. Fabrication of customized sectional impression trays in management of patients with limited mouth opening: a simple and unique approach.

    Science.gov (United States)

    Krishna Ch, Vamsi; Mahendranadh Reddy, K; Gupta, Nidhi; Mahadev Shastry, Y; Chandra Sekhar, N; Aditya, Venkat; Reddy, G V K Mohan

    2013-01-01

    Impression making is not only important but is also the most significant step in the fabrication of any fixed or removable prosthesis. Proper impression making may be hindered by certain pathologic conditions. Reduced mouth opening is one of the common mechanical obstructions for proper orientation of the impression tray in the patient's mouth. In patients with trismus induced by submucous fibrosis, the procedure may be even more difficult to carry out because of reduced tissue resiliency and obliteration of vestibular spaces. Use of sectional trays offers one of the alternatives to overcome the problem of restricted mouth opening. Fabrication of customized impression trays according to the patient dentition improves the accuracy of impression making. The present case reports describe the fabrication of sectional custom trays designed for dentulous patients with chronic tobacco-induced submucous fibrosis.

  7. Fabrication of Customized Sectional Impression Trays in Management of Patients with Limited Mouth Opening: A Simple and Unique Approach

    Directory of Open Access Journals (Sweden)

    Vamsi Krishna CH

    2013-01-01

    Full Text Available Impression making is not only important but is also the most significant step in the fabrication of any fixed or removable prosthesis. Proper impression making may be hindered by certain pathologic conditions. Reduced mouth opening is one of the common mechanical obstructions for proper orientation of the impression tray in the patient’s mouth. In patients with trismus induced by submucous fibrosis, the procedure may be even more difficult to carry out because of reduced tissue resiliency and obliteration of vestibular spaces. Use of sectional trays offers one of the alternatives to overcome the problem of restricted mouth opening. Fabrication of customized impression trays according to the patient dentition improves the accuracy of impression making. The present case reports describe the fabrication of sectional custom trays designed for dentulous patients with chronic tobacco-induced submucous fibrosis.

  8. Sand hazards on tourist beaches.

    Science.gov (United States)

    Heggie, Travis W

    2013-01-01

    Visiting the beach is a popular tourist activity worldwide. Unfortunately, the beach environment is abundant with hazards and potential danger to the unsuspecting tourist. While the traditional focus of beach safety has been water safety oriented, there is growing concern about the risks posed by the sand environment on beaches. This study reports on the death and near death experience of eight tourists in the collapse of sand holes, sand dunes, and sand tunnels. Each incident occurred suddenly and the complete burial in sand directly contributed to the victims injury or death in each case report.

  9. [A comparative study of mechanical properties of materials for custom-made impression trays used by implant-fixed restorations].

    Science.gov (United States)

    Gvetadze, R Sh; Abramian, S V; Rusanov, F S; Nubarian, A P; Ivanov, A A

    2012-01-01

    Materials for custom-made impression trays used for impression by implant fixed restorations were compared in the study. The analysis included such values as flexural strength and elasticity modulus, impression material adhesion strength with the use of adhesive and without it. Light-cured plastic Elite LC Tray had the best rates of bending strength and elasticity modulus and the Protakril M had the highest adhesion strength both with and without adhesive.

  10. Efficacy of Home-use Bleaching Agents Delivered in Customized or Prefilled Disposable Trays: A Randomized Clinical Trial.

    Science.gov (United States)

    Carlos, N R; Bridi, E C; Amaral, Flb; França, Fmg; Turssi, C P; Basting, R T

    The purpose of this study was to evaluate bleaching methods containing hydrogen peroxide (HP) or carbamide peroxide (CP), dispensed in customized or prefilled trays, in terms of color change, tooth sensitivity, gingival irritation, acceptance, and comfort. Seventy-five volunteers were randomly selected and distributed according to the whitening agent (n=25): 10% HP dispensed in prefilled trays (Opalescence Go 10%) and 9.5% HP (Pola Day) and 10% CP both delivered in customized trays (Opalescence PF 10%). HP was applied for 30 min/d for 14 days (d), and CP for 8 h/d for 14 days. Evaluations were performed at baseline and at 7 days and 14 days of treatment. Color change was measured with Commission internationale de l'éclairage color coordinates (L*, a*, b*), Vita Classical, and 3D Master scales. A visual analog scale was used to assess tooth sensitivity, acceptance of the method and degree of comfort of the tray. Gingival irritation was evaluated as present or absent and localized or generalized. Regarding gingival irritation, tray acceptance, and tooth sensitivity, no differences were observed among the groups at any time (p>0.05). As for degree of comfort, 10% HP showed lower scores (comfortable) than 10% CP, with significant differences (p0.05). The Δb average was higher at 14 days (p0.05). Localized gingival irritation was observed in both tray methods. Mild tooth sensitivity was observed with time, regardless of the bleaching agent concentration or the application time. Color change was similar for all the groups at 7 days and 14 days, but there was a greater reduction in the yellow hue at 14 days. All the bleaching methods were highly accepted and effective in promoting whitening. Although prefilled trays are generally comfortable, they proved less comfortable than customized trays.

  11. An In Vitro Study of the Bond Strength of Five Adhesives Used for Vinyl Polysiloxane Impression Materials and Tray Materials

    OpenAIRE

    Kumar, Surender; Gandhi, Udey Vir; Banerjee, Saurav

    2013-01-01

    Although stock trays often provide mechanical retention for elastomeric impression materials, manufacturers typically recommend the use of an adhesive, whether a stock or custom tray is used. The mention of the bond strength on the adhesive packaging is not available, therefore the clinician has no idea whatsoever of the ideal adhesive. The aim of this study was to evaluate the bond strength of three vinyl polysiloxane (VPS) materials, one with a poly(methyl methacrylate) autopolymerizing (PM...

  12. Hydrodynamics and Mass Transfer of Jet Co-flow Packing Tray

    Institute of Scientific and Technical Information of China (English)

    刘国标; 兰仁水; 王树楹; 余国琮

    2005-01-01

    The jet co-flow packing tray(JCPT) with three different types of perforation in equal opening fraction was tested in two rectangular columns with 0.12 m in width and 0.27 m in length operated with air-water system.The influences of gas phase orifice F-factor and clear liquid height He on the amount of liquid lifted, Q, were examined. The corresponding correlation between Q with F-factor and equivalent diameter of perforated holes as well as Hc was obtained. Furthermore, the non-steady state mass transfer performance of JCPT was tested by the humidification of air with water. Finally, by the analysis of data and comparison, it was found that the JCPT tray with single cap and two holes exhibited the highest mass transfer efficiency and best performance.

  13. Use of slow-release fertilizer on the production of sweet potatoes plantlets in tray

    Directory of Open Access Journals (Sweden)

    Amarílis Beraldo Rós

    2013-12-01

    Full Text Available The production of plantlets in containers generally requires the use of fertilizers. The aim of this study was to evaluate the production of sweet potato in styrofoam trays using slow-release fertilizer. The experiment was carried out, under a screen-protected nursery, in a factorial scheme 5x5, with five doses of slow-release fertilizer NPK 19-06-10 (0, 50, 100, 150 e 200 g per 25 kg de substrate and five times of plantlets permanence in tray (14, 28, 42, 56 and 70 days after planting the cuttings. The number and dry matter of roots and leaves were evaluated. The number of roots was not influenced by fertilizer addition. In general, there is not damage to plantlets growth until the highest dose used. Therefore, the fertilizer addition increases the sweet potato plants growth and the dose of 200 g per 25 kg of substrate is responsible for the best results.

  14. The new diagnosing method basing on the frequency analysis of human's nails in T-RAY

    Science.gov (United States)

    Ma, Pengcheng; Xiao, Long

    2011-02-01

    It has been reported that many kinds of sickness can be reflected in one's nails. And because of the special composition and structure of nails, they are very suitable for T-ray detecting. Therefore we want to see whether we can diagnose some sickness by only analyzing the transmission of the nails. The experiments consist of three parts. In the first part, we took 200 samples which came from about 20 years old people. By that way, we got that the peak transmission wavelengths of human's nail is about 1.7THz and we almost acknowledged the characteristics of nails. Then we changed our samples coming from different ages, and some interesting phenomenon were coming out. Lastly, by detecting the nails which are taken from special patients, we discovered some sickness can be detected using T-ray.

  15. PROCESSING OF MONAZITE SAND

    Science.gov (United States)

    Calkins, G.D.; Bohlmann, E.G.

    1957-12-01

    A process for the recovery of thorium, uranium, and rare earths from monazite sands is presented. The sands are first digested and dissolved in concentrated NaOH, and the solution is then diluted causing precipitation of uranium, thorium and rare earth hydroxides. The precipitate is collected and dissolved in HCl, and the pH of this solution is adjusted to about 6, precipitating the hydroxides of thorium and uranium but leaving the rare earths in solution. The rare earths are then separated from the solution by precipitation at a still higher pH. The thorium and uranium containing precipitate is redissolved in HNO/sub 3/ and the two elements are separated by extraction into tributyl phosphate and back extraction with a weakly acidic solution to remove the thorium.

  16. Moving sand dunes

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    In several desert areas, the slow motion of sand dunes can be a challenge for modern human activities and a threat for the survival of ancient places or archaeological sites. However, several methods exist for surveying the dune fields and estimate their migration rate. Among these methods, the use of satellite images, in particular of those freely available on the World Wide Web, is a convenient resource for the planning of future human settlements and activities.

  17. Spacecraft materials studies on the Aerospace Corporation tray on EOIM-3

    Science.gov (United States)

    Stuckey, Wayne K.; Hemminger, Carol S.; Steckel, Gary L.; Hills, Malina M.; Hilton, Michael R.

    1995-01-01

    A passive tray was flown on the Effects of Oxygen Interaction with Materials experiment on STS-46 (EOIM-3) with 82 samples from The Aerospace Corporation. A variety of advanced materials related to potential uses on future spacecraft were included for evaluation representing optical coatings, lubricants, polymers, composites, carbon-carbon composite protective coatings, graphite protective coatings, thermal-control materials, and some samples of current materials. An overview of the available results from the investigations of these materials is presented.

  18. Motion Law Analysis and Structural Optimization of the Ejection Device of Tray Seeder

    Science.gov (United States)

    Luo, Xin; Hu, Bin; Dong, Chunwang; Huang, Lili

    An ejection mechanism consisting four reset springs, an electromagnet and a seed disk was designed for tray seeder. The motion conditions of seeds in the seed disk were theoretical analyzed and intensity and height of seed ejection were calculated. The motions of the seeds and seed disk were multi-body dynamic simulated using Cosmos modules plug-in SolidWorks software package. The simulation results showed the consistence with the theoretical analysis.

  19. LDEF (Postflight), M0001 : Heavy Ions in Space, Tray H03

    Science.gov (United States)

    1990-01-01

    LDEF (Postflight), M0001 : Heavy Ions in Space, Tray H03 The post landing photograph of the Heavy Ions in Space Experiment was taken from the Orbiter's cargo bay access hatch during post landing opera tions to prepare the Orbiter for the ferry flight from the Dryden Flight Research Center to the Kennedy Space Center. The photograph shows extensive damage to the multi-layer thermal insulation blanket. The tape joints appear to have failed along two (2) sides of each experiment module and allowed the multi layer thermal insulation blanket to curled back over its self. The golden colored surfaces that have been exposed are the top sheet of the experiment's Lexan detector stacks that are held securely in place by the Z shaped aluminum structure. A light tan stain can be seen on the LDEF end structure along the upper edge of the experiment tray flange. Lighter stains that appear to be finger prints are also visible on the trays top flange. The paint on the top layer of the thermal blankets, origi nally white, now appears brown or light tan. The fragments of aluminum in the lower two quad rants appear to be the results of delamination of the vapor deposited aluminum from the thin aluminized Mylar thermal film.

  20. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

    "Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local

  1. The impact of particle shape on the angle of internal friction and the implications for sediment dynamics at a steep, mixed sand-gravel beach

    Science.gov (United States)

    Stark, N.; Hay, A. E.; Cheel, R.; Lake, C. B.

    2014-08-01

    The impact of particle shape on the angle of internal friction, and the resulting impact on beach sediment dynamics, is still poorly understood. In areas characterized by sediments of specific shape, particularly non-rounded particles, this can lead to large departures from the expected sediment dynamics. The steep slope (1 : 10) of the mixed sand-gravel beach at Advocate Harbour is stable in large-scale morphology over decades, despite a high tidal range of 10 m or more, and intense shore-break action during storms. The Advocate sand (d plate-like shape (Corey Shape Index, CSI ≈ 0.2-0.6). High angles of internal friction of this material were determined using direct shear, ranging from φ ≈ 41 to 49°, while the round to angular gravel was characterized as φ = 33°. The addition of 25% of the elliptic plate-like sand-sized material to the gravel led to an immediate increase in friction angle to φ = 38°. Furthermore, re-organization of the particles occurred during shearing, characterized by a short phase of settling and compaction, followed by a pronounced strong dilatory behavior and an accompanying strong increase of resistance to shear and, thus, shear stress. Long-term shearing (24 h) using a ring shear apparatus led to destruction of the particles without re-compaction. Finally, submerged particle mobilization was simulated using a tilted tray submerged in a water-filled tank. Despite a smooth tray surface, particle motion was not initiated until reaching tray tilt angles of 31° and more, being ≥7° steeper than for motion initiation of the gravel mixtures. In conclusion, geotechnical laboratory experiments quantified the important impact of the elliptic, plate-like shape of Advocate Beach sand on the angles of internal friction of both pure sand and sand-gravel mixtures. The resulting effect on initiation of particle motion was confirmed in tilting tray experiments. This makes it a vivid example of how particle shape can contribute to the

  2. Sediment mathematical model for sand ridges and sand waves

    Institute of Scientific and Technical Information of China (English)

    LI Daming; WANG Xiao; WANG Xin; LI Yangyang

    2016-01-01

    A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equation with two-dimensional shallow water equations and wave reflection-diffraction equation of mild slope, a two-dimensional coupling model is established and a validation is carried out by observed hydrogeology, tides, waves and sediment. The numerical results are compared with available observations. Satisfactory agreements are achieved. This coupling model is then applied to the Dongfang 1-1 Gas Field area to quantitatively predict the movement and evolution of submarine sand ridges and sand waves. As a result, it is found that the sand ridges and sand waves movement distance increases year by year, but the development trend is stable.

  3. Preliminary design, construction and evaluation of robot of tomato seed planting for the trays of greenhouse

    Directory of Open Access Journals (Sweden)

    J Ghezavati

    2015-09-01

    Full Text Available Introduction: From an economic viewpoint, tomato is considered as the second most valuable crop after potato. It is also preceded by the potato in terms of per capita consumption in the world. In 2008, the cultivation area used for the tomato as equal to 163,539 hectares in Iran and the production of it was equal to 5,887,715 tons with an average production of 117,887 tons in 4352 hectares in the provinces, respectively. Having high production volume and quality, costly hybrid seeds are currently used for the major planting areas of vegetable in Iran. Most of the used transplanted seedlings are 83%. Since the seeds are expensive, the percentage of seedlings and healthy and disease-free seeds should be used for maximized germination and be transferred to the fields of open space. Preparing seedlings in transplanting trays is a technology to respond to this need. Trays are covered with a layer of Peat and Miculite fertilizers. Then, one seed is manually placed in each cell after gauging and preparing a suitable field. However, manually placing seeds is time-consuming and requires hard labor. Sixteen working labors per hour are required for 15 × 7 cell in order to have 10200 seedlings grown in 100 trays. Due to lack of adequate labor, production capacity of greenhouses is reduced, especially in the farming season when finding labor for planting vegetable sprouts is laborious. Therefore, mechanizing tray seeding operations is essential to increase the capacity of the growing industry of greenhouses in Iran. Materials and Methods: Initially, the tomato seeds were examined in the laboratory. The most important parameters of the study included size, shape, weight, the speed of getting out of the tank and the minimum carrying speed. Then, a vacuum-based single seed picking unit was prepared to investigate the factors influencing the design, so that a single tomato seed can be harvested from the masses. The most important factors considered in the

  4. Desulfurization characteristics by seawater with stereoscopic and swirl parallel flow tray%立体旋液式并流塔板的海水脱硫特性

    Institute of Scientific and Technical Information of China (English)

    荆瑞静; 王晋刚; 张少峰

    2012-01-01

    The absorption efficiency of stereoscopic and swirl parallel flow trays with different turning angles of blade (30°, 45°, and 60°) were measured for single tray, double trays with co-rotating, and double trays with counter-rotating under different operating conditions in SO2 -seawater testing system. The effects of turning angle of blade, liquid flux and liquid gas ratio on absorption efficiency were analyzed. The result showed that under the best operating condition for the seawater flue gas desulfurization, turning angle of blade 60°, liquid-gas ratio of 19. 07 L· m-3 and double trays with counter-rotating, the absorption efficiency was 85%. The stereoscopic and swirl parallel flow tray presents good characteristics in a relatively wide range of operating condition because of its distinctive structure and concurrent flow in whole tower.

  5. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  6. Sand dollar sites orogenesis

    Science.gov (United States)

    Amos, Dee

    2013-04-01

    The determinology of the humble sand dollars habitat changing from inception to the drastic evolution of the zone to that of present day. Into the cauldron along the southern Californian 'ring of fire' lithosphere are evidence of geosynclinals areas, metasedimentary rock formations and hydrothermal activity. The explanation begins with 'Theia' and the Moon's formation, battles with cometary impacts, glacial ages, epochs with evolutionary bottlenecks and plate tectonics. Fully illustrated the lecture includes localised diagrams and figures with actual subject photographic examples of plutonic, granitic, jade and peridodite. Finally, the origins of the materials used in the lecture are revealed for prosecution by future students and the enjoyment of interested parties in general.

  7. Sand Storms Trigger Alarm

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ After an unusually humid winter with at least 10 snowfalls in Beijing, a severe andstorm blown by strong winds bringing with it thousands of tons of desert sand took many residents of the city by surprise.On the morning of March 20, Beijingers woke up to see clouds of yellow dust in the air and a sky that was an ominous orange in color.The loose soil and dust that had traveled htmdreds of miles from deserts in Mongolia and China's northwest blanketed Beijing's streets, covering parked vehicles, bikes, roofs and even plant life,as well as making its way into people's homes.

  8. Fortune Cookie Sand Dunes

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-432, 25 July 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of small barchan sand dunes in the north polar region near 71.7oN, 51.3oW. Some of them are shaped like fortune cookies. The message these dunes provide: winds blow through this region from the lower right toward the upper left. The steep slip face slopes of these dunes, which point toward the upper left, indicate the wind direction. The scene is illuminated by sunlight from the upper right. The image is 3 km (1.9 mi) wide.

  9. Study of the interocclusal distortion in impressions taken with different types of closed-mouth trays and two types of impression materials

    OpenAIRE

    Mañes-Ferrer, José Félix; Selva-Otaolaurruchi, Eduardo José; Parra-Arenos, Carmina; Selfa-Bas, Isabel

    2010-01-01

    The aim of this study was to compare different types of impression trays for the closed-mouth impression technique, using two different types of impression material. For this study, five different types of impression trays were used with two different types of impression materials, one of addition silicone and the other of polyether. We designed a model used for taking the impressions and for measuring interocclusal distortion. The results obtained show that the impression trays COE (GC (R) G...

  10. A family of sand automata

    CERN Document Server

    Faulkner, Nicholas

    2012-01-01

    We study some dynamical properties of a family of two-dimensional cellular automata: those that arise from an underlying one dimensional sand automaton whose local rule is obtained using a latin square. We identify a simple sand automaton G whose local rule is algebraic, and classify this automaton as having equicontinuity points, but not being equicontinuous. We also show it is not surjective. We generalise some of these results to a wider class of sand automata.

  11. Dilatometric Characterization of Foundry Sands

    Directory of Open Access Journals (Sweden)

    M. Břuska

    2012-04-01

    Full Text Available The goal of this contribution is summary of physical – chemistry properties of usually used foundry silica and no – silica sands in Czech foundries. With the help of dilatometry analysis theoretical assumptions of influence of grain shape and size on dilatation value of sands were confirmed. Determined was the possibility of dilatometry analysis employment for preparing special (hybrid sands with lower and/or more linear character of dilatation.

  12. Pressure produced on the residual maxillary alveolar ridge by different impression materials and tray design: an in vivo study.

    Science.gov (United States)

    Reddy, Subash M; Mohan, Chenthil Arun; Vijitha, D; Balasubramanian, R; Satish, A; Kumar, Mahendira

    2013-12-01

    Increased ridge resorption may occur due to inappropriate pressure applied during final impression making phase of complete denture fabrication. This study was done to evaluate the pressure applied on the residual ridge while making impressions with two tray designs (with and without spacer) using, zinc oxide eugenol and light body polyvinyl siloxane impression material. Five edentulous subjects were randomly selected. For each of the five subjects four maxillary final impressions were made and were labelled as, Group A-Impression made with tray without spacer using zinc oxide eugenol impression, Group B-Impression made with tray with spacer using zinc oxide eugenol impression material, Group C-Impression made with tray without spacer using light body polyvinyl siloxane impression material, Group D-Impression made with tray with spacer using light body polyvinyl siloxane impression material. During the impression procedure a closed hydraulic system was used to remotely measure the pressures produced in three areas. The pressure produced were calibrated according to the micro strain record. Statistical comparisons of readings were done using t test and ANOVA. The acquired data revealed that ZOE produced an average pressures value of 26.534 and 72.05 microstrain, while light body PVS produced 11.430 and 37.584 microstrain value with and without spacer respectively. Significantly high values were recorded on the vault of the palate when using trays without spacer. The use of light body polyvinyl siloxane and zinc oxide eugenol impression material showed insignificant difference. Within the limitations of this study, tray design has a significantly effected on the pressures produced, while the impression materials does not have any significant difference.

  13. Triaxial tests in Fontainebleau sand

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2016-01-01

    The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note that the tes......The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note...... that the testing procedure and the data processing were carried out according to the specifications of ETCS-F1.97....

  14. Pré-enraizamento de mudas de mandioquinha-salsa em diferentes bandejas e substratos com fungos micorrízicos arbusculares Pre-rooting of rhizomes of peruvian carrot in different trays and substrates with arbuscular micorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Carla Andréia da Cunha Martins

    2007-02-01

    Full Text Available Realizou-se este trabalho com o objetivo de estudar a colonização radicular por fungos micorrízicos arbusculares (FMAs no período de pré-enraizamento da mandioquinha-salsa (Arracacia xanthorrhiza Bancroft. Os tratamentos constaram de dois substratos e dois tamanhos de bandeja de isopor. Utilizou-se um substrato comum constituído de 30% de composto orgânico, 30% de solo argiloso e 30% de areia e um substrato comercial Plantmax® Hortaliças; os tamanhos de bandejas de isopor foram: 128 células/bandeja (38 cm³ por célula e 200 células/bandeja (18 cm³ por célula. Efetuou-se uma inoculação mista de FMAs com solo inóculo composto pelas espécies Gigaspora margarita e Glomus clarum. Houve em ambos os substratos restrita resposta à inoculação dos FMAs, pela baixa colonização radicular, variando de 0,63 a 2,14% no substrato comercial e 7,93 a 15,09% no substrato comum. O substrato comum não apresentou características físicas desejáveis (aeração e drenagem para um bom desenvolvimento das raízes de mandioquinha-salsa durante a fase de pré-enraizamento. O substrato comercial apresentou maiores médias para a variável área e comprimento radicular em todas as coletas. A área radicular variou de 21,50 cm² com 30 DAP a 68,22 cm² com 60 DAP, enquanto o comprimento radicular variou de 2,64 m com 30 DAP a 12,64 m com 60 DAP. A bandeja de 200 células (18 cm³ célula/bandeja não foi adequada para a produção de mudas de mandioquinha-salsa.The objective of the work was to study the root colonization by arbuscular micorrhizal fungi (AMF during the development of Peruvian carrot rhizomes (Arracacia xanthorrhiza Bancroft. The treatments consisted of two substrates and two polystyrene trays sizes. A common substrate constituted of 30% of organic compost, 30% of loamy soil and 30% of sand, and a commercial substrate "Plantmax® Hortaliças"; and polystyrene trays sizes of 128 cells/tray (38 cm³ per cell and 200 cells/tray (18 cm

  15. A Comparative Evaluation of Accuracy of the Dies Affected by Tray Type, Material Viscosity, and Pouring Sequence of Dual and Single Arch Impressions- An In vitro Study.

    Science.gov (United States)

    Kulkarni, Poonam R; Kulkarni, Rahul S; Shah, Rupal J; Chhajlani, Rahul; Saklecha, Bhuwan; Maru, Kavita

    2017-04-01

    The clinician's skill, impression techniques, and materials play a very important role in recording fine details in an impression for accuracy of fixed partial denture prosthesis. Impression of prepared teeth and of the opposing arch can be recorded simultaneously by dual-arch trays, while the full arch metal trays are used for impressions of prepared teeth in one arch. To measure and compare the accuracy of working dies made from impressions with metal and plastic dual arch trays and metal full arch trays, for two viscosities of impression material and by changing the sequence of pour of working and non-working sides. A balanced design with independent samples was used to study the three variables (tray type, impression material viscosity, and pouring sequence). An impression made by dual arch trays and single arch trays were divided in to three groups (Group A-plastic dual arch tray, Group B-metal dual arch tray, Group C-full arch metal stock tray). Out of these three groups, two groups (Group A and B) were subdivided in to four subgroups each and one group (Group C) was subdivided in to two subgroups. A sample size of 30 was used in each subgroup yielding a total 300 impressions in three groups or ten subgroups. Impressions were made of a machined circular stainless steel die. All three dimensions (Occlusogingival, Mesiodistal, and Buccolingual) of the working dies as well as stainless steel standard die were measured three times, and the mean was used for the three standard sample values to which all working dies means were compared. Statistical analysis used for this study was a 3-factor analysis of variance with hypothesis testing at α =0.05. With respect to the selection of impression material viscosity statistically significant differences were found in the dies for the buccolingual and mesiodistal dimensions. Metal dual arch trays were slightly more accurate in the mesiodistal dimension in comparison to the plastic trays in reference of tray selection and

  16. Influence of metallic trays on the ac resistance and ampacity of low-voltage cables under non-sinusoidal currents

    Energy Technology Data Exchange (ETDEWEB)

    Demoulias, Charis; Labridis, Dimitris P.; Dokopoulos, Petros; Gouramanis, Kostas [Aristotle University of Thessaloniki, Department of Electrical and Computer Engineering, Thessaloniki (Greece)

    2008-05-15

    This paper investigates the influence of metallic trays on the ac resistance of PVC insulated, low-voltage (0.6/1.0 kV) cables made according to CENELEC standard HD603. The investigation is made with a validated finite element model for the fundamental and higher harmonic frequencies. It is shown that the cable's effective resistance is affected significantly by the relative magnetic permeability and specific conductivity of the tray, while the tray's dimensions do not affect it. The orientation of the cable with respect to the tray also influences the ac resistance of the phase and neutral conductors. An ampacity derating factor is defined and calculated for various cable cross-sections and harmonic loads. The presence of a metallic tray is shown to cause an additional derating of cable's ampacity which is relatively significant at large cable cross-sections. Working examples demonstrate the application of the results in calculating the ampacity of low-voltage cables and in assessing the energy savings that will result from the use of active harmonic filters. (author)

  17. Computational study of the heat transfer of an avian egg in a tray.

    Science.gov (United States)

    Eren Ozcan, S; Andriessens, S; Berckmans, D

    2010-04-01

    The development of an embryo in an avian egg depends largely on its temperature. The embryo temperature is affected by its environment and the heat produced by the egg. In this paper, eggshell temperature and the heat transfer characteristics from one egg in a tray toward its environment are studied by means of computational fluid dynamics (CFD). Computational fluid dynamics simulations have the advantage of providing extensive 3-dimensional information on velocity and eggshell temperature distribution around an egg that otherwise is not possible to obtain by experiments. However, CFD results need to be validated against experimental data. The objectives were (1) to find out whether CFD can successfully simulate eggshell temperature from one egg in a tray by comparing to previously conducted experiments, (2) to visualize air flow and air temperature distribution around the egg in a detailed way, and (3) to perform sensitivity analysis on several variables affecting heat transfer. To this end, a CFD model was validated using 2 sets of temperature measurements yielding an effective model. From these simulations, it can be concluded that CFD can effectively be used to analyze heat transfer characteristics and eggshell temperature distribution around an egg. In addition, air flow and temperature distribution around the egg are visualized. It has been observed that temperature differences up to 2.6 degrees C are possible at high heat production (285 mW) and horizontal low flow rates (0.5 m/s). Sensitivity analysis indicates that average eggshell temperature is mainly affected by the inlet air velocity and temperature, flow direction, and the metabolic heat of the embryo and less by the thermal conductivity and emissivity of the egg and thermal emissivity of the tray.

  18. A sand wave simulation model

    NARCIS (Netherlands)

    Nemeth, A.A.; Hulscher, S.J.M.H.; Damme, van R.M.J.

    2003-01-01

    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water su

  19. Regeneration of dredged sand waves

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; Knaapen, Michiel; Scholl, Olaf; Scholl, O.; Trenteseaux., A.; Garlan, T.

    2000-01-01

    Sand waves form a wavy pattern in the offshore sandy seabed. Since their crests reduce the navigability, it is important to know their evolution. A simple model is presented to estimate the recovery of sand wave amplitudes. This model is partially based on the similarity with sea ripples and

  20. Namibia : triaxial test on sand

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.; Jacobsen, Kim P.

    In connection with a harbour project the friction angle of a fine sand is required. On Friday 13 March 1998 the Danish Geotechnical Institute (DGI) delivered app. 2.5 kg sand for testing at the Geotechnical Engineering Laboratory, Aalborg University. The present Data Report summarises the results...

  1. Bubble Formation Characteristics from a Sieve Tray with Liquid Cross—flow

    Institute of Scientific and Technical Information of China (English)

    XUSonglin; XUShimin

    2002-01-01

    An apparatus,desinged to simulate bubbling of a sieve tray operated in froth regime,was employed. Bubble contact angles in and above the incipient weeping regimer for an air-water-plexiglas system were investigated. The influence of both liquid cross-flow and gas up-flow upon bubble contact angles was examined. A model considering the influence of liquid cross-flow was developed to predict bubble size from a sieve hole in froth operation regime.The comparison shows that the bubble sizes predicted by the present model are consistent with our experimental values and the available published experimental data.

  2. IMPACT OF DYNAMICAL HYDRATION SHELL AROUND HA PROTEIN ON NONLINEAR CONCENTRATION DEPENDENT T-RAYS ABSORPTION

    Directory of Open Access Journals (Sweden)

    YIWEN SUN

    2013-10-01

    Full Text Available T-rays is sensitive to covalently cross-linked proteins and can be used to probe unique dynamic properties of water surrounding a protein. In this paper, we demonstrate the unique absorption properties of the dynamic hydration shells determined by hemagglutinin (HA protein in terahertz frequency. We study the changes arising from different concentrations in detail and show that nonlinear absorption coefficient is induced by the dynamic hydration water. The binary and ternary component model were used to interpret the nonlinearity absorption behaviors and predict the thickness of the hydration shells around the HA protein in aqueous phase.

  3. Modeling Separation Dynamics in a Multi-Tray Bio-Ethanol Distillation Column

    DEFF Research Database (Denmark)

    Løhndorf, Petar Durdevic; Pedersen, Simon; Yang, Zhenyu

    2015-01-01

    The high energy consumption of popularly used distillation columns has motivated development of energytracking dynamic models with the ultimate objective for potential better energy and quality control of these separation facilities. A dynamic model being able to explicitly describe both...... the product quality and energy consumption in a typical bio-ethanol distillation column is proposed in this paper. The proposed model is derived based on mass and energy balance principles, with an empirical model of the evaporation dynamics of liquids on column trays. The model parameters are identified...

  4. Preliminary design, construction and evaluation of robot of tomato seed planting for the trays of greenhouse

    Directory of Open Access Journals (Sweden)

    J Ghezavati

    2015-09-01

    Full Text Available Introduction: From an economic viewpoint, tomato is considered as the second most valuable crop after potato. It is also preceded by the potato in terms of per capita consumption in the world. In 2008, the cultivation area used for the tomato as equal to 163,539 hectares in Iran and the production of it was equal to 5,887,715 tons with an average production of 117,887 tons in 4352 hectares in the provinces, respectively. Having high production volume and quality, costly hybrid seeds are currently used for the major planting areas of vegetable in Iran. Most of the used transplanted seedlings are 83%. Since the seeds are expensive, the percentage of seedlings and healthy and disease-free seeds should be used for maximized germination and be transferred to the fields of open space. Preparing seedlings in transplanting trays is a technology to respond to this need. Trays are covered with a layer of Peat and Miculite fertilizers. Then, one seed is manually placed in each cell after gauging and preparing a suitable field. However, manually placing seeds is time-consuming and requires hard labor. Sixteen working labors per hour are required for 15 × 7 cell in order to have 10200 seedlings grown in 100 trays. Due to lack of adequate labor, production capacity of greenhouses is reduced, especially in the farming season when finding labor for planting vegetable sprouts is laborious. Therefore, mechanizing tray seeding operations is essential to increase the capacity of the growing industry of greenhouses in Iran. Materials and Methods: Initially, the tomato seeds were examined in the laboratory. The most important parameters of the study included size, shape, weight, the speed of getting out of the tank and the minimum carrying speed. Then, a vacuum-based single seed picking unit was prepared to investigate the factors influencing the design, so that a single tomato seed can be harvested from the masses. The most important factors considered in the

  5. Simulation and Optimization of Strengthening the Gas-Liquid Mass Transfer Structure in Tray Column

    Directory of Open Access Journals (Sweden)

    Duan Jihai

    2015-01-01

    Full Text Available This paper presented the analysis of the effect of the mesh layers, installation height and opening rate on gas-liquid two-phase flow field by numerical simulation, which based on Euler-Euler model and identified the best liquid-gas ratio. The simulation results showed that: when the installation height of the square mesh was 25 mm and opening rate was 55.7%, the gas holdup distribution in the upper part of the mesh became higher and improved the liquid velocity distribution. Meanwhile, the gas-liquid distribution on trays was more uniform.

  6. Sand swimming lizard: sandfish

    CERN Document Server

    Maladen, Ryan D; Kamor, Adam; Goldman, Daniel I

    2009-01-01

    We use high-speed x-ray imaging to reveal how a small (~10cm) desert dwelling lizard, the sandfish (Scincus scincus), swims within a granular medium [1]. On the surface, the lizard uses a standard diagonal gait, but once below the surface, the organism no longer uses limbs for propulsion. Instead it propagates a large amplitude single period sinusoidal traveling wave down its body and tail to propel itself at speeds up to ~1.5 body-length/sec. Motivated by these experiments we study a numerical model of the sandfish as it swims within a validated soft sphere Molecular Dynamics granular media simulation. We use this model as a tool to understand dynamics like flow fields and forces generated as the animal swims within the granular media. [1] Maladen, R.D. and Ding, Y. and Li, C. and Goldman, D.I., Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard, Science, 325, 314, 2009

  7. 2010 oil sands performance report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    With the depletion of traditional energy resources and the rising demand for energy, oil sands have become an important energy resource for meeting energy needs. Oil sands are a mixture of water, sand, clay and bitumen which is recovered either through open pit mining or in situ drilling techniques. The bitumen is then converted into syncrude or sold to refineries for the production of gasoline, diesel or other products. Shell has oil sands operations in Alberta and the aim of this report is to present its 2010 performance in terms of CO2, water, tailings, land, and reclamation and engagement. This document covers several of Shell's operations in the Muskeg River and Jackpine mines, Scotford upgrader, Peace River, Orion, Seal, Cliffdale and Chipmunk. It provides useful information on Shell's oil sands performance to governments, environmental groups, First Nations, local communities and the public.

  8. Sand harm in taklimakan Desert highway and sand control

    Institute of Scientific and Technical Information of China (English)

    HANZhiwen; WANGTao; SUNQingwei; DONGZhibao; WANGXunming

    2003-01-01

    Reputed as a wonderful achievement of the world’s highway construction history,the Taklimakan Desert highway is nor facing serious sand drift encroachment problems due to its 447-km-long passage of sand sea consisting of crescent dunes,barchan chains,compound transverse dune ridges and complex megadunes.To solve some technical problems in the protection of the highway from sang drift encroachment,desert experts have been conducting the theoretical and applied studies on sand movement laws;causes,severities and time-space differentiation of sand drift damages;and control ways including mechanical,chemical and biological measures.In this paper the authors give an overall summry on the research contents and recent progress in the control of sand drift damages in China and hold that the theoretical researc results and practices in the prevention of sand drift encroachment on the cross-desert highway represnt a breakthrough and has an cpoch-making significance.Since the construction of protective forest along the cross-desert highway requires large amount of ground water,what will be its environmental consequence and whether it can effectively halt sand drift encroachment on the highway forever are the questions to be studied urgently.

  9. The Effect of Edentulous Maxillary Impression Tray Designs When Flabby Tissue Is Present: An In Vitro Study.

    Science.gov (United States)

    Shin, Jae-Ok; Huh, Yoon-Hyuk; Cho, Lee-Ra; Park, Chan-Jin

    2016-01-01

    A model with simulated flabby tissue was fabricated by modifying the standard maxillary edentulous acrylic resin cast to evaluate the effect of maxillary impression tray design on the displacement of flabby tissue. Seven groups of trays were fabricated using different combinations of relief spaces and escape holes. After impression taking, test and control casts were scanned and three-dimensional digital models were superimposed. Negative deviations were recorded at the point of the alveolar crest, the posterior part of the flabby tissue, and the middle of the palate, while positive deviations were recorded at the point of the anterior part of flabby tissue. The amount and characteristics of tissue displacement differed with tray design and the relief method used.

  10. Evaluation of effect of tray space on the accuracy of condensation silicone, addition silicone and polyether impression materials: an in vitro study.

    Science.gov (United States)

    Kumar, Varun; Aeran, Himanshu

    2012-09-01

    Optimal thickness of impression materials in the custom tray in order to get the most accurate impression. To investigate the effect of different tray spacer thickness on the accuracy and the dimensional stability of impressions made from monophasic condensation silicone, addition silicone and polyether impression materials. Three different types of elastomeric monophasic impression materials were used for making the impression of a master die with tray having tray spacer thickness of 2, 4 and 6 mm. Each type of impression was poured in die stone after 1 h. Each cast was analyzed by a travelling microscope and compared with the master die. The data was tabulated and subjected to statistical evaluation. The results of the study indicated that the impressions made from 2 to 4 mm spaced trays produced more accurate stone casts when compared to 6 mm spaced tray. No statistical significant differences were observed between the accuracy and dimensional stability of the three materials tested. Minimum changes were observed when the cast was poured after 1 h and the tray space was 2 mm for all the materials tested. It is therefore advisable not to exceed tray space of 2 mm.

  11. ANALISIS KELAYAKAN TEKNIS DAN FINANSIAL DARI INVESTASI PENGADAAN TRAY DRYER BERBAHAN BAKAR BIOMASSA PADA USAHA ARANG TEMPURUNG KELAPA BERBASIS EKSPOR (Studi Kasus di Tropica Nucifera Industry – Yogyakarta

    Directory of Open Access Journals (Sweden)

    Fanny Widadie

    2013-11-01

    Full Text Available The purpose of the study is to assess the technical and financial feasibility of procurement investment Tray Dryer fueled biomass to operations of coconut shell charcoal briquette in PT. Tropica Nucifera Industry. The result showed that investment-Tray Dryer on cocnut shell charcoal briquette bussiness was highly feasibile both the technical and financial aspects. The technical aspect was seen that the quantity-production capabilities of coconut shell charcoal briquettes using a dryer-Tray Dryer could be increased 15 percent compared the previous consdition-used of solar energy. While the quality of the charcoal briquettes produced from Tray Dryer was a much butter quality, moisture content (6.39%; ash (2.65%; carbon-bound (85.83%, compared to using sunlight, water content (15.89; ash (2.57% and carbon-bound (77.32%.The financial aspects of procurement Tray Dryer investment that its value was more feasible than previous, nothing Tray Dryer. Coconut shell charcoal briquet enterprises without using Tray Dryer was feasible to be done with NPV 1,058,928.12, IRR 63%, Payback Period 1 year and 9 moths, Net B/C 2.25 and analysis of swicthcing value reached 20 percent. And after the business using Tray Drayer, the financial analysis was much more feasible with NPV 2,285,500,498.12, IRR 113%, Payback Period 11 months, Net B/C 3.5 and analysis of switching value reached 50 percent.

  12. Estudio piloto comparativo entre cubetas individuales en implantoprótesis Comparative pilot study between custom trays in implant prosthetic

    Directory of Open Access Journals (Sweden)

    A Orozco Varo

    2006-08-01

    Full Text Available El presente trabajo tiene por objeto realizar un estudio piloto sobre las características más idóneas de las cubetas de impresión para prótesis sobre implantes, adjuntando una revisión de la literatura y proponiendo un material y diseño específico para cubetas individuales en prótesis sobre implantes.The present work have to object to make a pilot study about the ideal characteristcs of impression trays for implant prosthodontic, attaching a literature review and suggesting a specific material and desing for custom trays in implant prosthodontic.

  13. Classification of osteosarcoma T-ray responses using adaptive and rational wavelets for feature extraction

    Science.gov (United States)

    Ng, Desmond; Wong, Fu Tian; Withayachumnankul, Withawat; Findlay, David; Ferguson, Bradley; Abbott, Derek

    2007-12-01

    In this work we investigate new feature extraction algorithms on the T-ray response of normal human bone cells and human osteosarcoma cells. One of the most promising feature extraction methods is the Discrete Wavelet Transform (DWT). However, the classification accuracy is dependant on the specific wavelet base chosen. Adaptive wavelets circumvent this problem by gradually adapting to the signal to retain optimum discriminatory information, while removing redundant information. Using adaptive wavelets, classification accuracy, using a quadratic Bayesian classifier, of 96.88% is obtained based on 25 features. In addition, the potential of using rational wavelets rather than the standard dyadic wavelets in classification is explored. The advantage it has over dyadic wavelets is that it allows a better adaptation of the scale factor according to the signal. An accuracy of 91.15% is obtained through rational wavelets with 12 coefficients using a Support Vector Machine (SVM) as the classifier. These results highlight adaptive and rational wavelets as an efficient feature extraction method and the enormous potential of T-rays in cancer detection.

  14. Study of UV-curable composite resin of transfer tray for orthodontics

    Institute of Scientific and Technical Information of China (English)

    Lin YANG; Wei WU; Bao-hua XU; Pei-zeng JIA; Jun NIE

    2008-01-01

    Objectives: the aim of this study was to invest-igate the properties of UV-curable composite resin of transfer tray for indirect bonding system of the lingual brackets. Methods: the conversion of double-bond in the different concentration of UV-initiator was monitored by real time infrared (RTIR). The three-point flexure strength was measured by a universal testing machine. The storage modulus, loss modulus, and loss factor (tan delta) of the resin were measured by a Dynamic Mechanical Analyzer. The cytotoxicity of composite resin was evaluated by the agar covering test. Results: the dou-ble bond conversion exceeded 70% at [benzophe-none] = 0.7 wt.%, [Ethyl 4-dimethylaminobenzoate] = 0.7 wt.% and [2-Hydroxy-2-methyl-1-phenyl propa-non] = 1 wt.%. The mean value of flexural strength came to 122 MPa. The value of storage modulus was 1.04 × 109 MPa at 23℃. The glass transition temperature was 142℃. The toxicity grade was zero at 2 h and one at 24 h. Conclusions: in the preliminary evaluations, we indi-cated that the UV-curable composite resin of transfer tray could satisfy the clinical requirements.

  15. Sand engine quells the coast's hunger for sand

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

    An artificial peninsula at Ter Heijde is designed to feed the coast with sediment. Scientists are investigating whether this kind of sand engine could be the Netherlands’ answer to rising sea levels.

  16. Sand engine quells the coast's hunger for sand

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

    An artificial peninsula at Ter Heijde is designed to feed the coast with sediment. Scientists are investigating whether this kind of sand engine could be the Netherlands’ answer to rising sea levels.

  17. Spectroscopic characterization of a Nigerian standard sand: Igbokoda sand

    CSIR Research Space (South Africa)

    Ojuri, OO

    2017-01-01

    Full Text Available the Middle Ordovician St. Peter Sandstone near Ottawa, Illinois, had been picked by the American Society for Testing and Materials (ASTM) as the reference sand to employ in testing cement and strength of concrete [9]. To the best of our knowledge... and magnetic resonance spectroscopic techniques due to its importance in cement, geotechnical/geo-environmental research in Nigeria. This should halt importation of standard silica sand for mortar and concrete testing...

  18. Saltation of Non-Spherical Sand Particles

    Science.gov (United States)

    Wang, Zhengshi; Ren, Shan; Huang, Ning

    2014-01-01

    Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the structure of the wind sand flow are rarely studied, and the effect of mid-air collision is usually neglected. In fact, sand grains are rarely round in natural environments. In this paper, we first analyzed the drag coefficients, drag forces, and starting friction wind speeds of sand grains with different shapes in the saltation process, then established a sand saltation model that considers the coupling effect between wind and the sand grains, the effect of the mid-air collision of sand grains, and the effect of the sand grain shape. Based on this model, the saltation process and sand transport rate of non-spherical sand particles were simulated. The results show that the sand shape has a significant impact on the saltation process; for the same wind speed, the sand transport rates varied for different shapes of sand grains by as much as several-fold. Therefore, sand shape is one of the important factors affecting wind-sand movement. PMID:25170614

  19. Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2011-04-01

    Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

  20. Management recommendations: Sand Lake Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Sand Lake National Wildlife Refuge, by a land use specialist. Recommendations, time frame and...

  1. The Formation Design of Noise Reducers from Plywood, Foam, Tray, dan Coconut Fiber for Static Sources

    Directory of Open Access Journals (Sweden)

    Melati Fachrul

    2011-09-01

    Full Text Available Research  was  conducted  in  a  semi-anechoic  room  using  a  method  referring  to  the  ISO  3745.  The design  used  is  the Hemisphere in which the source of noise is analogous to engines in an industry. The value reduction in the rate of sound  power is obtained by comparing the sound power level before and after control is given. The noise control test materials used  consist  of  layers  of plywood,  foam,  fiber  and  tray  (egg  box.  The  effectiveness  of  these  materials  is  tested  by measuring the sound transmission loss (STL. Test results reveal that the sound power level (Lw of the source of noise produces a high Lw which is 99.6 dB. at a frequency of 8000 Hz. The measurement of Lw on the source of noise which is  covered  by  plywood produces  a  total  of  78.66  dB  Lw  with  an  Lw  reduction  of  21.02%. The  measurement  on  the sound  source  covered  by  plywood  and foam  materials  produces  a  total  of  47.79  dB  Lw  with  an  Lw reduction  of 52.02%. The measurement of Lw by combining plywood, foam, and tray produces a total of 33.02 dB Lw with an Lw reduction of 66.84%. The measurement of the total Lw after being covered by plywood, foam, fiber, and tray is a total of 31.94 Lw dB with an Lw reduction of 67.93%. 

  2. A simple method for fabricating custom sectional impression trays for making definitive impressions in patients with microstomia

    OpenAIRE

    Bachhav, Vinay Chila; Aras, Meena Ajay

    2012-01-01

    Objective: A maximum mouth opening that is smaller than the size of a complete denture can make prosthetic treatment challenging. This article describes a simple technique used to fabricate maxillary and mandibular custom sectional impression trays for making definitive impressions in patients with microstomia.

  3. An in vitro study of the bond strength of five adhesives used for vinyl polysiloxane impression materials and tray materials.

    Science.gov (United States)

    Kumar, Surender; Gandhi, Udey Vir; Banerjee, Saurav

    2014-03-01

    Although stock trays often provide mechanical retention for elastomeric impression materials, manufacturers typically recommend the use of an adhesive, whether a stock or custom tray is used. The mention of the bond strength on the adhesive packaging is not available, therefore the clinician has no idea whatsoever of the ideal adhesive. The aim of this study was to evaluate the bond strength of three vinyl polysiloxane (VPS) materials, one with a poly(methyl methacrylate) autopolymerizing (PMMA) specimen and another with a light-polymerizing tray material (VLC), using the adhesive recommended by the manufacturer of the impression material, and two universal adhesives. A total of ninety specimens (15 × 15 × 20 mm) were used, 45 specimens were made in PMMA and rest 45 was made in VLC. Five paint-on adhesives (Coltene, Caulk, 3M, universal Zhermack and universal GC) were applied. Three impression materials, Affinis, Reprosil, and 3M, were mixed and injected into a perforated poly vinyl chloride cylinder. Tray specimens were positioned against the open cylinder end in contact with the VPS material. Tensile strength tests were conducted until adhesive separation failure. Mean values and standard errors of the adhesive strength were recorded in MPa for each material combination. GC paint-on universal adhesive provided significantly higher adhesive strength values.

  4. Study on Jet Coflow Packing Tray%喷射式并流填料塔板的研究

    Institute of Scientific and Technical Information of China (English)

    蓝仁水; 高长宝; 王树楹

    2002-01-01

    Experimental study on hydrodynamics and mass transfer efficiency of jet coflow packing tray (JCPT)was conducted in a φ285 mm column and a φ200 mm column, respectively. Compared with new vertical sieve traywhich has been applied in the petrochemical industry since 1968, the JCPT has lower pressure drop, higher capacityand higher mass transfer efficiency, and seems promising in commercial application.

  5. Measurement and Prediction of Interfacial Area on a DistiIlation Tray

    Institute of Scientific and Technical Information of China (English)

    宋海华; 李天一; 李红海

    2003-01-01

    In this paper the modern electron-optical equipment is used to translate the clear image of speed-moving bubbles in bubbling liquid on a sieve tray into the digital information stored in computer, and the computer-aided image-processing technique is utilized to measure the bubble size distributions and interfacial areas under various operating conditions. And the dynamic behavior of bubbles in turbulent liquid is analyzed theoretically; the mechanism of bubble deformation and breakage is explored on the basis of Kolmogoroff′s isotropic turbulence hypothesis; the mathematical model for predicting the gas-liquid interfacial area is proposed. The comparison between the simulated results and the experimental data shows that the model is higher in accuracy, simple in form and convenient in use.

  6. Cellulase production through solid-state tray fermentation, and its use for bioethanol from sorghum stover.

    Science.gov (United States)

    Idris, Ayman Salih Omer; Pandey, Ashok; Rao, S S; Sukumaran, Rajeev K

    2017-10-01

    The production of cellulase by Trichoderma reesei RUT C-30 under solid-state fermentation (SSF) on wheat bran and cellulose was optimized employing a two stage statistical design of experiments. Optimization of process parameters resulted in a 3.2-fold increase in CMCase production to 959.53IU/gDS. The process was evaluated at pilot scale in tray fermenters and yielded 457IU/gDS using the lab conditions and indicating possibility for further improvement. The cellulase could effectively hydrolyze alkali pretreated sorghum stover and addition of Aspergillus niger β-glucosidase improved the hydrolytic efficiency 174%, indicating the potential to use this blend for effective saccharification of sorghum stover biomass. The enzymatic hydrolysate of sorghum stover was fermented to ethanol with ∼80% efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Interim Status Closure Plan Open Burning Treatment Unit Technical Area 16-399 Burn Tray

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Holterman, Luciana R. [Los Alamos National Laboratory

    2012-05-07

    This closure plan describes the activities necessary to close one of the interim status hazardous waste open burning treatment units at Technical Area (TA) 16 at the Los Alamos National Laboratory (LANL or the Facility), hereinafter referred to as the 'TA-16-399 Burn Tray' or 'the unit'. The information provided in this closure plan addresses the closure requirements specified in the Code of Federal Regulations (CFR), Title 40, Part 265, Subparts G and P for the thermal treatment units operated at the Facility under the Resource Conservation and Recovery Act (RCRA) and the New Mexico Hazardous Waste Act. Closure of the open burning treatment unit will be completed in accordance with Section 4.1 of this closure plan.

  8. 维医沙疗对兔膝关节骨性关节炎关节软骨超微结构的影响%Experimental study of the effects of Uyghur sand therapy on the ultrastructure of knee articular cartilage in osteoarthritis

    Institute of Scientific and Technical Information of China (English)

    卫荣; 迪丽娜尔·马合木提; 胡汉华; 哈未拉提·吾甫尔

    2009-01-01

    Objective To study the effects of sand therapy on the ultrastructure of knee articular cartilage in rabbits with osteoarthritis ( OA ) and provide evidence of the effectiveness of sand therapy for OA in Uyghur medicine. Methods Models of knee OA were established by fixing with gypsum the right hind limbs of 28 rabbits. Of these, twenty-six rabbits were divided randomly into a free movement group and a free movement plus sand therapy group, and their left hind limbs were used as normal controls. Another two rabbits were used as specimens. The thirteen rabbits in the free movement group after the gypsum fixings were removed were allowed free movement every day for 20 days; the thirteen rabbits in the free movement plus sand therapy group had free movement plus sand therapy every day. The ultrastructure of each rabbit' s knee articular cartilage was observed using an electron microscope. Results Models of knee OA were established successfully. The changes in the ultrastructure of the knee articular cartilage revealed cell swelling, cell debris in part of the cartilage lacunae, and cartilage cells proliferating. The matrix of cartilage cells was thin, hetero chromatin concentrated on the margin and presented in a crescent form. Cell organellae decreased obviously, which was a sign of apoptosis. After the gypsum fixings were removed, the proliferation of cartilage cells gradually increased and rough endoplasmic reticula increased remarkably in the articular cartilages of the right hind knees of the free movement group. Cell pycnosis, disintegration and necrosis could be found in a few cells. The movement of the affected knees of the group treated with sand therapy plus free movement improved more significantly , and the changes in cartilage ultrastructure revealed more cell active proliferation, more rough endoplasmic reticu-lum, more cell surface processes and more matrix fibers. The morphology of cartilage cells in the control knees remained normal. Conclusion It is

  9. Self-control assessments of capuchin monkeys with the rotating tray task and the accumulation task.

    Science.gov (United States)

    Beran, Michael J; Perdue, Bonnie M; Rossettie, Mattea S; James, Brielle T; Whitham, Will; Walker, Bradlyn; Futch, Sara E; Parrish, Audrey E

    2016-08-01

    Recent studies of delay of gratification in capuchin monkeys using a rotating tray (RT) task have shown improved self-control performance in these animals in comparison to the accumulation (AC) task. In this study, we investigated whether this improvement resulted from the difference in methods between the rotating tray task and previous tests, or whether it was the result of greater overall experience with delay of gratification tasks. Experiment 1 produced similar performance levels by capuchins monkeys in the RT and AC tasks when identical reward and temporal parameters were used. Experiment 2 demonstrated a similar result using reward amounts that were more similar to previous AC experiments with these monkeys. In Experiment 3, monkeys performed multiple versions of the AC task with varied reward and temporal parameters. Their self-control behavior was found to be dependent on the overall delay to reward consumption, rather than the overall reward amount ultimately consumed. These findings indicate that these capuchin monkeys' self-control capacities were more likely to have improved across studies because of the greater experience they had with delay of gratification tasks. Experiment 4 and Experiment 5 tested new, task-naïve monkeys on both tasks, finding more limited evidence of self-control, and no evidence that one task was more beneficial than the other in promoting self-control. The results of this study suggest that future testing of this kind should focus on temporal parameters and reward magnitude parameters to establish accurate measures of delay of gratification capacity and development in this species and perhaps others.

  10. Effect of impression tray design upon the accuracy of stone casts produced from a single-phase medium-bodied polyvinyl siloxane impression material.

    Science.gov (United States)

    Saunders, W P; Sharkey, S W; Smith, G M; Taylor, W G

    1992-06-01

    The study examined the accuracy of stone casts produced from impressions taken in stock polycarbonate trays, some of which had been strengthened with autopolymerizing polymethyl methacrylate resin and four designs of custom-made trays. Impressions of an acrylic master model of the mandibular arch on which two extracoronal crown preparations and one intracoronal inlay preparation had been carried out were taken using a medium-bodied polyvinyl siloxane material. Each preparation had been intended with a reference point for later measurement. Five impressions were taken for each type of tray and these were cast in die-stone after 24 h. The distances between the points were measured with a reflex microscope and the means determined for each design of tray. The mean difference between casts produced from the various tray designs and the acrylic master model were determined for each of the distances between the three measuring points. Statistical analysis showed that, with the stock trays, there were no significant differences between any of the modifications, or between them and the acrylic model, for any of the three distances (P greater than 0.1). When the results from the custom-made trays were analysed there were statistical differences between the acrylic model and the casts from the unperforated tray with no stops (P = 0.02), and between the unperforated tray with no stops and the perforated with stops for the distance A-B (P less than 0.01). There were no other significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

    Science.gov (United States)

    Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

    2016-06-01

    The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

  12. Optimal array of sand fences.

    Science.gov (United States)

    Lima, Izael A; Araújo, Ascânio D; Parteli, Eric J R; Andrade, José S; Herrmann, Hans J

    2017-03-24

    Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth's climate. Many different types of fence have been designed and their effects on the sediment transport dynamics studied since many years. However, the search for the optimal array of fences has remained largely an empirical task. In order to achieve maximal soil protection using the minimal amount of fence material, a quantitative understanding of the flow profile over the relief encompassing the area to be protected including all employed fences is required. Here we use Computational Fluid Dynamics to calculate the average turbulent airflow through an array of fences as a function of the porosity, spacing and height of the fences. Specifically, we investigate the factors controlling the fraction of soil area over which the basal average wind shear velocity drops below the threshold for sand transport when the fences are applied. We introduce a cost function, given by the amount of material necessary to construct the fences. We find that, for typical sand-moving wind velocities, the optimal fence height (which minimizes this cost function) is around 50 cm, while using fences of height around 1.25 m leads to maximal cost.

  13. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

    2014-01-01

    Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

  14. DPTM simulation of aeolian sand ripple

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Aeolian sand ripple and its time evolution are simulated by the discrete particle tracing method (DPTM) presented in this paper. The difference between this method and the current methods is that the former can consider the three main factors relevant to the formation of natural aeolian sand ripples,which are the wind-blown sand flux above the sand bed formed by lots of sand particles with different di-ameters,the particle-bed collision and after it the rebound and ejection of sand particles in the sand bed,the saltation of high-speed sand particles and the creep of low-speed sand particles,respectively. The simulated aeolian sand ripple is close to the natural sand ripple not only in basic shape and characteristic,particle size segregation and stratigraphy,but also in formation stages. In addition,three important speeds can be obtained by this method,which are the propagation speed of the saturated aeolian sand ripple and the critical frictional wind speeds of emergence and disappearance of sand ripple.

  15. DPTM simulation of aeolian sand ripple

    Institute of Scientific and Technical Information of China (English)

    ZHENG XiaoJing; BO TianLi; XIE Li

    2008-01-01

    Aeolian sand ripple and its time evolution are simulated by the discrete particle tracing method (DPTM) presented in this paper.The difference between this method and the current methods is that the former can consider the three main factors relevant to the formation of natural aeolian sand ripples, which are the wind-blown sand flux above the sand bed formed by lots of sand particles with different di-ameters, the particle-bed collision and after it the rebound and ejection of sand particles in the sand bed, the saltation of high-speed sand particles and the creep of low-speed sand particles, respectively.The simulated aeolian sand ripple is close to the natural sand ripple not only in basic shape and characteristic, particle size segregation and stratigraphy, but also in formation stages.In addition, three important speeds can be obtained by this method, which are the propagation speed of the saturated aeolian sand ripple and the critical frictional wind speeds of emergence and disappearance of sand ripple.

  16. Dry reusing and wet reclaiming of used sodium silicate sand

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitable technique for the used sand. When the recycled sand is used as support sand, the used sand is only reused by dry process including breaking, screening, dust-removal, etc., and it is not necessary that the used sand is reclaimed with strongly rubbing and scraping method, but when the recycled sand is used as facing sand (or single sand), the used sand must be reclaimed by wet method for higher removal rate of the residual binders. The characteristics and the properties of the dry reused sand are compared with the wet reclaimed sand after combining the different use requirements of support sand and facing sand (or single sand), and above the most adaptive scheme has also been validated.

  17. Sand and Water Table Play

    Science.gov (United States)

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  18. Sand and Water Table Play

    Science.gov (United States)

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  19. Impact on sand and water

    NARCIS (Netherlands)

    Bergmann, R.P.H.M.

    2007-01-01

    In this thesis we investigate the impact of a body on sand and water. When a body impacts a free surface in the inertial regime the series of events is the following: On impact material is blown away in all directions and an impact cavity forms. Due to the hydrostatic pressure from the sides the cav

  20. Silo model tests with sand

    DEFF Research Database (Denmark)

    Munch-Andersen, Jørgen

    Tests have been carried out in a large silo model with Leighton Buzzard Sand. Normal pressures and shear stresses have been measured during tests carried out with inlet and outlet geometry. The filling method is a very important parameter for the strength of the mass and thereby the pressures...

  1. experimental studies of sand production from unconsolidated ...

    African Journals Online (AJOL)

    ES Obe

    Production of sand during oil and gas exploration causes severe operational prob- ... duction such as risk of well failure, erosion of pipelines and surface facilities, sand separa- tion and disposal ... ment, theoretical and numerical analysis have.

  2. Clinical trial investigating success rates for polyether and vinyl polysiloxane impressions made with full-arch and dual-arch plastic trays.

    Science.gov (United States)

    Johnson, Glen H; Mancl, Lloyd A; Schwedhelm, E Ricardo; Verhoef, Douglas R; Lepe, Xavier

    2010-01-01

    Success rates for making fixed prosthodontic impressions based on material and tray selection are not known. The purpose of this clinical study was to compare first impression success rates for 2 types of impression material and 2 impression tray systems. Dual-viscosity impressions were made with a vinyl polysiloxane (VPS) (Aquasil Ultra Monophase/Aquasil Ultra XLV) and a polyether (PE) (Impregum Penta Soft HB/Impregum Garant Soft LB) impression material. The first impression made was evaluated for success or failure using developed criteria. Fifty senior dental students participated. The type of impression material alternated for each new patient. A full-arch perforated plastic (President Tray) or a plastic dual-arch impression tray (Tri-Bite) was used based on clinical guidelines. Impression success rates were compared using logistic regression, fitted using the method of generalized estimating equations (alpha=.05). One hundred ninety-one impressions were evaluated, and the overall success rate was 61% for VPS and 54% for PE (P=.39). Additional regression analyses, adjusted for potential confounders, did not indicate a difference between the 2 systems (P=.35). There was little difference in success rates between the 2 materials when a full-arch tray was used (50% versus 49% success, P=.89), whereas a larger difference was apparent with the use of dual-arch trays (70% success with VPS versus 58% success with PE, P=.21). The most common critical defect was located on the preparation finish line (94%), and the most common operator error was inadequate gingival displacement (15%). There was little difference in success rates between VPS and PE when full-arch impression trays were used, but there was greater success when using VPS with dual-arch trays. For single teeth, the trend favored VPS, but when more than one prepared tooth per impression was involved, the success rate was higher for PE. Copyright 2010 The Editorial Council of the Journal of Prosthetic

  3. The new diagnosing method basing on the frequency analysis of human's nails in T-RAY

    Energy Technology Data Exchange (ETDEWEB)

    Ma Pengcheng; Xiao Long, E-mail: pengchengma@smail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2011-02-01

    It has been reported that many kinds of sickness can be reflected in one's nails. And because of the special composition and structure of nails, they are very suitable for T-ray detecting. Therefore we want to see whether we can diagnose some sickness by only analyzing the transmission of the nails. The experiments consist of three parts. In the first part, we took 200 samples which came from about 20 years old people. By that way, we got that the peak transmission wavelengths of human's nail is about 1.7 THz and we almost acknowledged the characteristics of nails. Then we changed our samples coming from different ages, and some interesting phenomenon were coming out. Lastly, by detecting the nails which are taken from special patients, we discovered some sickness can be detected using T-ray.

  4. UK silica sand resources for fracking

    OpenAIRE

    Mitchell, Clive

    2013-01-01

    UK silica sand resources for fracking Clive Mitchell, Industrial Minerals Specialist, British Geological Survey, Keyworth, Nottingham, NG12 5GG Email: Silica sand is high purity quartz sand that is mainly used for glass production, as foundry sand, in horticulture, leisure and other industrial uses. One specialist use is as a ‘proppant’ to enhance oil and gas recovery. This presentation will focus on this application, particularly for shale gas recovery where it is mo...

  5. Fabrication of Customized Sectional Impression Trays in Management of Patients with Limited Mouth Opening: A Simple and Unique Approach

    OpenAIRE

    Vamsi Krishna CH; Mahendranadh Reddy, K.; Nidhi Gupta; Y. Mahadev Shastry; Chandra Sekhar, N.; Venkat Aditya; G. V. K. Mohan Reddy

    2013-01-01

    Impression making is not only important but is also the most significant step in the fabrication of any fixed or removable prosthesis. Proper impression making may be hindered by certain pathologic conditions. Reduced mouth opening is one of the common mechanical obstructions for proper orientation of the impression tray in the patient’s mouth. In patients with trismus induced by submucous fibrosis, the procedure may be even more difficult to carry out because of reduced tissue resiliency and...

  6. Treating tar sands formations with karsted zones

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX)

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  7. Sand Waves. Report 1. Sand Wave Shoaling in Navigation Channels

    Science.gov (United States)

    1992-09-01

    heights range from 0.8 m in the Minas Basin, Bay of Fundy (Dalrymple 1984) to 6.0 m in the Bahia Blanca Estuary, Argentina (Aliotta and Perillo 1987...26 PART IV: SITE-SPECIFIC SAND WAVE SHOALING PROBLEMS .. ........ 30 Columbia River Navigation Channel ........ ............... .. 30 Panama ...problem location discussed in this report is at St. Andrew Bay near Panama City, Florida. A relatively short section of the jettied inlet channel requires

  8. Bacteriological quality of aquacultured freshwater fish portions in prepackaged trays stored at 3 degrees C.

    Science.gov (United States)

    González-Rodríguez, M N; Sanz, J J; Santos, J A; Otero, A; García-López, M L

    2001-09-01

    Fresh trout fillets and salmon slices packed in trays were obtained from two multinational chain supermarkets and evaluated for freshness and bacteriological quality immediately after packaging and during storage at 3 degrees C. Initial aerobic counts at 30 and 25 degrees C were significantly (P fish was spoiled. Although initial presumptive Staphylococcus aureus counts were approximately 3 log CFU/g, only 4 of 84 selected colonies belonged to this species. Neither Salmonella nor antimicrobial residues were detected in any sample. Ethanol content in salmon slices did not significantly (P > 0.05) increase until they became inedible. Significant correlation (r = +0.72, P < 0.05) was observed between this chemical index and viable counts at 30 degrees C only when salmon slices were inedible. Trout fillets were acceptable for 7 days, and salmon slices showed signs of spoilage after 4 days. Although public health concerns associated with packed trout and salmon appear to be minimal, data on sensory quality, shelf life, and total viable and Enterobacteriaceae counts strongly suggest the need to improve the quality control systems used by European multinational retailers, especially for imported salmon.

  9. Independent Design of Multivariable Controllers for A 24-Tray Separating Mixture of Methanol and Water

    Directory of Open Access Journals (Sweden)

    Elham Sareban

    2015-03-01

    Full Text Available Most industrial processes are characterized with large uncertainties. To deal with these kinds of processes and achieve fast and accurate control in a stable fashion, the multiple-model control methods have been demonstrated to be very effective. It is difficult to build the precise mathematic model of the object and to accurately control the object with the traditional control methods. This paper applies H-infinity robust control strategies to a 24-tray separating a mixture of methanol and water. The idea has favorable controls on control targets (rise time, settling time, overshoot and undershoot, the interaction between input and output and help on stability of the system output. Then in order to show that the proposed controller affords a good robust performance consistently we have implemented four controllers.Performance analysis of the H-infinity robust controller, Model Predictive Control (MPC, conventional PID controller and also LQG/LTR has been done using MATLAB. The comparison of various time domain parameters was done to prove that the H-Infinity robust controller has best time characteristics and in face with uncertainties has better reacts as compared to other controllers. Beside this, MPC controller has satisfied result in robust stability.

  10. METHOD OF PROCESSING MONAZITE SAND

    Science.gov (United States)

    Welt, M.A.; Smutz, M.

    1958-08-26

    A process is described for recovering thorium, uranium, and rare earth values from monazite sand. The monazite sand is first digested with sulfuric acid and the resulting "monazite sulfate" solution is adjusted to a pH of between 0.4 and 3.0, and oxalate anions are added causing precipitation of the thorium and the rare earths as the oxalates. The oxalate precipitate is separated from the uranium containing supernatant solution, and is dried and calcined to the oxides. The thorium and rare earth oxides are then dissolved in nitric acid and the solution is contacted with tribntyl phosphate whereby an organic extract phase containing the cerium and thorium values is obtained, together with an aqueous raffinate containing the other rare earth values. The organic phase is then separated from the aqueous raffinate and the cerium and thorium are back extracted with an aqueous medium.

  11. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Klint, K.E.S.; Nilsson, B.

    2012-01-01

    of the various types of sand lenses is discussed, primarily in relation to the depositional and glaciotectonic processes they underwent. Detailed characterization of sand lenses facilitates such interpretations. Finally, the observations are linked to a more general overview of the distribution of sand lenses......Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...... occurring in various glacial environments. This study specifically focuses on the appearance and spatial distribution of sand lenses in tills. It introduces a methodology on how to measure and characterize sand lenses in the field with regard to size, shape and degree of deformation. A set of geometric...

  12. A compact topology for sand automata

    CERN Document Server

    Dennunzio, Alberto; Masson, Benoît

    2008-01-01

    In this paper, we exhibit a strong relation between the sand automata configuration space and the cellular automata configuration space. This relation induces a compact topology for sand automata, and a new context in which sand automata are homeomorphic to cellular automata acting on a specific subshift. We show that the existing topological results for sand automata, including the Hedlund-like representation theorem, still hold. In this context, we give a characterization of the cellular automata which are sand automata, and study some dynamical behaviors such as equicontinuity. Furthermore, we deal with the nilpotency. We show that the classical definition is not meaningful for sand automata. Then, we introduce a suitable new notion of nilpotency for sand automata. Finally, we prove that this simple dynamical behavior is undecidable.

  13. Rheological Characterization of Green Sand Flow

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Spangenberg, Jon; Hovad, Emil

    2016-01-01

    The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantify...... module for characterizing granular materials. The new module enables viscosity measurements of the green sand as function of the shear rate at different flow rates, i.e. 0, 2, 4, 6, 8, 10, 12 and 15 L/min. The results show generally that the viscosity decreases with both the shear- and flow rate....... In addition, the measurements show that the green sand flow follows a shear-thinning behaviour even after the full fluidization point....

  14. Silo model tests with sand

    DEFF Research Database (Denmark)

    Munch-Andersen, Jørgen

    Tests have been carried out in a large silo model with Leighton Buzzard Sand. Normal pressures and shear stresses have been measured during tests carried out with inlet and outlet geometry. The filling method is a very important parameter for the strength of the mass and thereby the pressures...... as well as the flow pattern during discharge of the silo. During discharge a mixed flow pattern has been identified...

  15. Formation of Craters in Sand

    Directory of Open Access Journals (Sweden)

    Vanissra Boonyaleepun

    2007-06-01

    Full Text Available The diameter of craters formed by spheres of varying mass dropped into sand at low speed was studied. The relationship between the diameter of the crater formed and the kinetic energy of the projectile at impact was found to be of the same general form as that for planetary meteor craters. The relationship is shown to be a power law with exponent 0.17.

  16. Formation of Craters in Sand

    Directory of Open Access Journals (Sweden)

    Vanissra Boonyaleepun

    2007-06-01

    Full Text Available The diameter of craters formed by spheres of varying mass dropped into sand at low speed was studied. The relationship between the diameter of the crater formed and the kinetic energy of the projectile at impact was found to be of the same general form as that for planetary meteor craters. The relationship is shown to be a power law with exponent 0.17

  17. Thermal Properties of oil sand

    Science.gov (United States)

    LEE, Y.; Lee, H.; Kwon, Y.; Kim, J.

    2013-12-01

    Thermal recovery methods such as Cyclic Steam Injection or Steam Assisted Gravity Drainage (SAGD) are the effective methods for producing heavy oil or bitumen. In any thermal recovery methods, thermal properties (e.g., thermal conductivity, thermal diffusivity, and volumetric heat capacity) are closely related to the formation and expansion of steam chamber within a reservoir, which is key factors to control efficiency of thermal recovery. However, thermal properties of heavy oil or bitumen have not been well-studied despite their importance in thermal recovery methods. We measured thermal conductivity, thermal diffusivity, and volumetric heat capacity of 43 oil sand samples from Athabasca, Canada, using a transient thermal property measurement instrument. Thermal conductivity of 43 oil sand samples varies from 0.74 W/mK to 1.57 W/mK with the mean thermal conductivity of 1.09 W/mK. The mean thermal diffusivity is 5.7×10-7 m2/s with the minimum value of 4.2×10-7 m2/s and the maximum value of 8.0×10-7 m2/s. Volumetric heat capacity varies from 1.5×106 J/m3K to 2.11×106 J/m3K with the mean volumetric heat capacity of 1.91×106 J/m3K. In addition, physical and chemical properties (e.g., bitumen content, electric resistivity, porosity, gamma ray and so on) of oil sand samples have been measured by geophysical logging and in the laboratory. We are now proceeding to investigate the relationship between thermal properties and physical/chemical properties of oil sand.

  18. Effect of impression tray design and impression technique upon the accuracy of stone casts produced from a putty-wash polyvinyl siloxane impression material.

    Science.gov (United States)

    Saunders, W P; Sharkey, S W; Smith, G M; Taylor, W G

    1991-10-01

    This study examined the accuracy of stone casts produced from impressions taken in stock polycarbonate trays, some of which had been strengthened with autopolymerizing polymethyl methacrylate resin. Three techniques were used to make the impression of an acrylic master model of the mandibular arch on which two extracoronal preparations for bridgework and one intracoronal inlay preparation had been carried out. Each preparation had been indented with a reference point for later measurement. The impression material was a putty-wash polyvinyl siloxane material. Five impressions were taken for each type of tray for each impression technique and these were cast in die-stone after 24 h. The distances between the points were measured with a reflex microscope and the means determined for each design of tray. The mean difference between casts produced from the various tray designs and the acrylic master model were determined for each of the distances between the three measuring points for the various impression techniques. Statistical analysis showed that, with the polycarbonate stock trays, there were significant differences between some of the modifications and between them and the acrylic model, for the three distances (P less than 0.05). These differences were limited to one measurement for one design of tray for each of the two-stage impression methods. With the one-stage technique the unreinforced tray and those reinforced with acrylic, over the heels and anteriorly, and the barred design were statistically significantly different from the acrylic model for measurement A-B.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Evaluation of Durability Parameters of Concrete with Manufacture Sand and River Sand

    Science.gov (United States)

    Sangoju, Bhaskar; Ramesh, G.; Bharatkumar, B. H.; Ramanjaneyulu, K.

    2017-06-01

    Most of the states in our country have banned sand quarrying from the river beds, causing a scarcity of natural river sand for the construction sector. Manufacture sand (M-sand) is one of the alternate solutions to replace the river sand (R-sand) in concrete. The main aim of the present study is to evaluate the durability parameters of concrete with M-sand when compared to that of concrete with R-sand. Corrosion of reinforcement is one of the main deteriorating mechanisms of reinforced concrete due to the ingress of chloride ions or carbon-di-oxide. For comparative evaluation of durability parameters, accelerated tests such as Rapid Chloride Permeability Test, Rapid Chloride Migration Test and accelerated carbonation test were carried out on specimens of R-sand and M-sand. All tests were carried out after 90 days of casting. Test results reveal that the durability parameters of the concrete with M-sand in chloride induced environment is relatively better than that of concrete with R-sand and hence is recommended to use M-sand as a replacement to R-sand.

  20. Sand deposit-detecting method and its application in model test of sand flow

    Institute of Scientific and Technical Information of China (English)

    黎伟; 房营光; 莫海鸿; 谷任国; 陈俊生

    2013-01-01

    Against the background of the sand-flow foundation treatment engineering of Guangzhou Zhoutouzui variable cross-section immersed tunnel, a kind of sand deposit-detecting method was devised on the basis of full-scale model test of sand-flow method. The real-time data of sand-deposit height and radius were obtained by the self-developed sand-deposit detectors. The test results show that the detecting method is simple and has high precision. In the use of sand-flow method, the sand-carrying capability of fluid is limited, and sand particles are all transported to the sand-deposit periphery through crater, gap and chutes after the sand deposit formed. The diffusion range of the particles outside the sand-deposit does not exceed 2.0 m. Severe sorting of sand particles is not observed because of the unique oblique-layered depositing process. The temporal and spatial distributions of gap and chutes directly affect the sand-deposit expansion, and the expansion trend of the average sand-deposit radius accords with quadratic time-history curve.

  1. Rainfall intensity and phosphorus source effects on phosphorus transport in surface runoff from soil trays.

    Science.gov (United States)

    Shigaki, Francirose; Sharpley, Andrew; Prochnow, Luis Ignacio

    2007-02-01

    Phosphorus runoff from agricultural fields amended with mineral fertilizers and manures has been linked to freshwater eutrophication. A rainfall simulation study was conducted to evaluate the effects of different rainfall intensities and P sources differing in water soluble P (WSP) concentration on P transport in runoff from soil trays packed with a Berks loam and grassed with annual ryegrass (Lolium multiflorum Lam.). Triple superphosphate (TSP; 79% WSP), low-grade super single phosphate (LGSSP; 50% WSP), North Carolina rock phosphate (NCRP; 0.5% WSP) and swine manure (SM; 70% WSP), were broadcast (100 kg total P ha-1) and rainfall applied at 25, 50 and 75 mm h-1 1, 7, 21, and 56 days after P source application. The concentration of dissolved reactive (DRP), particulate (PP), and total P (TP) was significantly (Prunoff with a rainfall intensity of 75 than 25 mm h-1 for all P sources. Further, runoff DRP increased as P source WSP increased, with runoff from a 50 mm h-1 rain 1 day after source application having a DRP concentration of 0.25 mg L-1 for NCRP and 28.21 mg L-1 for TSP. In contrast, the proportion of runoff TP as PP was greater with low (39% PP for NCRP) than high WSP sources (4% PP for TSP) averaged for all rainfall intensities. The increased PP transport is attributed to the detachment and transport of undissolved P source particles during runoff. These results show that P source water solubility and rainfall intensity can influence P transport in runoff, which is important in evaluating the long-term risks of P source application on P transport in surface runoff.

  2. SAND

    DEFF Research Database (Denmark)

    Thorsen, Grete

    Der er udført et konsolideringsforsøg med bakkesand fra Lunds grusgrav, Lund no. O. forsøget er udført i samme konsolideringsapparat, som er anvendt til måling af deformationsegenskaberne af mange forskellige danske jordarter. Forsøgsresultaterne er søgt tolket som ved forsøg med andre jordarter....

  3. Study of the interocclusal distortion in impressions taken with different types of closed-mouth trays and two types of impression materials.

    Science.gov (United States)

    Mañes-Ferrer, José-Félix; Selva-Otaolaurruchi, Eduardo-José; Parra-Arenós, Carmina; Selfa-Bas, Isabel

    2010-01-01

    The aim of this study was to compare different types of impression trays for the closed-mouth impression technique, using two different types of impression material. For this study, five different types of impression trays were used with two different types of impression materials, one of addition silicone and the other of polyether. We designed a model used for taking the impressions and for measuring interocclusal distortion. The results obtained show that the impression trays COE (GC (R) GC America INC. Alsip) and Premier (Premier (R), Premier Dental Products Co. Canada) show a lesser degree of interocclusal distortion when taking closed-mouth impressions. In terms of impression materials, the polyether was the one that produced the best results. From a clinical point of view, our study shows that the use of these types of trays is absolutely recommendable when used according to the clinical indications for which they have been designed; that said, we must not fail to consider that selecting the proper type of tray is also important.

  4. Liquefaction of Sand under Low Confining Pressure

    Institute of Scientific and Technical Information of China (English)

    YANG Shaoli; Rolf Sandven; Lars Grande

    2003-01-01

    Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for the undrained behaviour of sand. In cyclic triaxial tests, pore water pressures built up during the cyclic loading and exceeded the confining cell pressure. This process was accompanied by a large sudden increase in axial deformation. The necessary number of cycles to obtain liquefaction was related to the confining cell pressure, the amplitude of cyclic loading and the relative density of sand.In addition, the patterns of pore water pressure response are different from those of sand samples with different relative densities. The test results are very useful for expounding scour mechanism around coastal structures since they relate to the low stress behaviour of the sand.

  5. Creep Behavior of Frozen Sand.

    Science.gov (United States)

    1981-06-01

    temperature and stress range. There was a 2strong stress dependance to S (r =0.95) for saturated Manchester Fine Sand which does not agree with RPT. The...Curves at High Stress 161 Ratio D/Du = 0.505 for Frozen HF’S at w=10% IV-20 Minimum Strain Rate Dependance on Stress 162 Ratio for Frozen MFS IV-21 Minimum...Strain Rate Dependance on Relative 163 Density for Frozen MFS IV-22 Temperature Stage Test on Frozen Saturated 164 MFS under a Load of D=9.24MPa Fig

  6. A single Time-of-Flight tray based on multigap resistive plate chambers for the STAR experiment at RHIC

    Science.gov (United States)

    Bonner, B.; Chen, H.; Eppley, G.; Geurts, F.; Lamas-Valverde, J.; Li, Ch.; Llope, W. J.; Nussbaum, T.; Platner, E.; Roberts, J.

    2003-08-01

    The STAR experiment at RHIC plans to implement a 60 m2 Time-of-Flight (TOF) system. The Multigap Resistive Plate Chamber (MRPC) is a suitable candidate for the STAR TOF system due to its time resolution of order of 60 ps with efficiencies in excess of 97%. We obtained this result with modules composed of 6 gas gaps of 220 μm and pad area of 20 cm2. In this paper, we report on the performance of this MRPC module and present the current status of the construction and installation into STAR of a prototype tray.

  7. Estudio piloto comparativo entre cubetas individuales en implantoprótesis Comparative pilot study between custom trays in implant prosthetic

    OpenAIRE

    A. Orozco Varo; R. Martínez de Fuentes; P Domínguez Cardoso; D. Cañadas Rodríguez; E Jiménez Castellanos

    2006-01-01

    El presente trabajo tiene por objeto realizar un estudio piloto sobre las características más idóneas de las cubetas de impresión para prótesis sobre implantes, adjuntando una revisión de la literatura y proponiendo un material y diseño específico para cubetas individuales en prótesis sobre implantes.The present work have to object to make a pilot study about the ideal characteristcs of impression trays for implant prosthodontic, attaching a literature review and suggesting a specific materia...

  8. Recent advances in waterglass sand technologies

    Institute of Scientific and Technical Information of China (English)

    ZHU Chun-xi

    2007-01-01

    This paper reports some new understandings and advances in waterglass sand technologies. The multiple chemical modification process can increase the binding strength of the waterglass sand by up to 50%-70%.Therefore, the additions of the modified waterglass can be decreased to 3.0%-4.0% for CO2 process and to 2.0%-2.5% for organic ester hardening process, and greatly improve the collapsibility and reclaimability of the sand. Based on the new understandings and experimental results reported in this paper, several original ideas, such as nano modification, have been proposed to promote advances of waterglass sand technologies,

  9. PROSPECTS FIXATION DRIFT SANDS PHYSICOCHEMICAL METHOD

    Directory of Open Access Journals (Sweden)

    Maujuda MUZAFFAROVA

    2016-09-01

    Full Text Available This article is based on the theoretical foundations of secure mobile sand being considered for reducing the negative impact of one of the manifestations of exogenous plains on such an important natural-technical system as a railroad. It suggests practical measures to build a system of design protection against sand drifts. The article also suggests ways to conserve resources and rational use of machinery and performers as well as the consolidation of mobile sand wet with water soluble waste of local production of waste dextrin. Consolidation is exposed on dry and wet sand.

  10. Innovative developments in sand reclamation technologies

    Directory of Open Access Journals (Sweden)

    R. Dañko

    2011-04-01

    Full Text Available Proper sand management and efficient sand reclamation system are two main factors influencing economical and ecological side of modern foundry plant. It is well known fact that the production of 1 metric ton of casting from ferrous alloys generates circa 1 metric ton of waste [1], which due to containing certain amounts of harmful and dangerous compounds should undergo a reclamation – at least of the main component, which means a silica sand grains. The paper present problems of scientific and development research concerning the innovative reclamation technologies of used foundry sands such as: mechanical-cryogenic reclamation and innovative thermal reclamation.

  11. Sand Failure Mechanism and Sanding Parameters in Niger Delta Oil Reservoirs

    OpenAIRE

    Sunday Isehunwa,; Andrew Farotade

    2010-01-01

    Sand production is a major issue during oil and gas production from unconsolidated reservoirs. In predicting the onset of sand production, it is important to accurately determine the failure mechanism and the contributing parameters. The aim of this study was to determine sand failure mechanism in the Niger-Delta, identify themajor contributing parameters and evaluate their effects on sanding.Completion and production data from 78 strings completed on 22 reservoirs in a Niger Delta oil Field ...

  12. Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Haider Abbas Khwaja

    2015-08-01

    Full Text Available Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM and Laser Scanning Microscopy (LSM analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0. Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

  13. STUDY ON THE GXD FLOAT VALVE TRAY WITH DOUBLE FLOW GUIDE%GXD型复式导流浮阀塔板的研究

    Institute of Scientific and Technical Information of China (English)

    高有飞

    2012-01-01

    The hydrodynamic performance of GXD float valve tray with double flow guide was studied using a synthetic glass rectangular towerd 000 mm×400 mm) device, and compared with DL float valve tray with flow guide and Fl float valve tray at the same opening porosity. Results show that GXD float valve tray displays good hydrodynamic performance,under the same gas velocity as compared with Fl float valve tray,its pressure drop is 25% lower and process capacity is more than 35% higher; its efficiency is about 15% higher than that of DL float valve tray. Even though the minimum operation limit for leakage intensity of GXD float valve tray is a bit higher than the others,distillation tower with GXD float valve tray exhibits not only low pressure drop,but also high operation efficiency and high distilled yield of light fractions.%在1 000 mm×400 mm有机玻璃方塔试验装置上考察GXD型复式导流浮阀塔板的流体力学性能,并在相同开孔率下与DL型导流浮阀塔板、F1型浮阀塔板的流体力学性能进行对比.结果表明:GXD型复式导流浮阀塔板具有良好的流体力学性能,相同气速下与F1型浮阀塔板相比,其压降降低约25%,处理能力提高约35%以上;与DL型浮阀塔板相比其效率提高约15%.虽然GXD型浮阀塔板泄漏强度的操作下限与其它浮阀塔板相比偏高,但该塔板不仅能降低分馏塔的压降,还可以提高操作效率和轻质油拔出率.

  14. Interfacial area between gases and liquid in a valve plate column and a bubble cap tray; Barubu danto oyobi hosho danto ni okeru kieki sesshoku menseki

    Energy Technology Data Exchange (ETDEWEB)

    Nakoua, M.; Dribika, M.; Besher, E

    1999-03-05

    A mathematical model has been developed for absorption accompanied by chemical reaction of H{sub 2}S and CO{sub 2} in alkanolamine solutions encountered in plants for natural gas sweetening in Libya. The model has been used to calculate actual number of plates in industrial columns. The model results errors in number of trays predictions due to the lack of procedures for estimating interfacial area for the in between flow regime that prevailed in two industrial plants. The developed correlation for interfacial area estimation for the in between flow regime gives zero error in number of trays prediction. (author)

  15. Three Dimensional Simulation of Liquid Flow on Distillation Tray%精馏塔板液相流场三维模拟

    Institute of Scientific and Technical Information of China (English)

    刘伯潭; 刘春江

    2002-01-01

    The liquid flow on a single-pass sieve distillation tray is simulated with a three-dimensional computational fluid dynamics (CFD) program with the K-ε turbulence model. In the model, a source term SMi is formulatedin the Navier-Stokes equations to represent the interfacial momentum transfer and another term Sc is added to themass transfer equation as the source of interfacial mass transfer. The simulation provides the detailed informationof the three-dimensional distribution of liquid velocity on the tray, the circulation area and the concentration profilealong the height of liquid layer.

  16. Lipase production by solid-state fermentation: cultivation conditions and operation of tray and packed-bed bioreactors.

    Science.gov (United States)

    Gutarra, Melissa L E; Cavalcanti, Elisa D C; Castilho, Leda R; Freire, Denise M G; Sant'Anna, Geraldo L

    2005-01-01

    The production of lipase by Penicillium simplicissimum in solid-state fermentation was studied using babassu cake as the basal medium. Tray-type and packed-bed bioreactors were employed. In the former, the influence of temperature; content of the medium, and medium supplementation with olive oil, sugarcane molasses, corn steep liquor, and yeast hydrolysate was studied. For all combinations of supplements, a temperature of 30 degrees C, a moisture content of 70%, and a concentration of carbon source of 6.25% (m/m, dry basis) provided optimum conditions for lipase production. When used as single supplements olive oil and molasses also were able to provide high lipase activities (20 U/g). Using packed-bed bioreactors and molasses-supplemented medium, optimum conditions for enzyme production were air superficial velocities above 55 cm/min and temperatures below 28 degrees C. The lower temperature optimum found for these reactors is probably related to radial heat gradient formation inside the packed bed. Maximum lipase activities obtained in these bioreactors (26.4 U/g) were 30% higher than in tray-type reactors.

  17. Cell size in trays for the production of strawberry plug transplants Tamanho das células em bandejas para produção de mudas de morangueiro

    Directory of Open Access Journals (Sweden)

    Gustavo Giménez

    2009-07-01

    Full Text Available The objective of this work was to evaluate the influence of cell sizes used for strawberry plug production in trays compared to bare root transplants, regarding initial plant size, harvest timing, and total strawberry fruit yield. Plug transplants were produced from runner tips rooted in trays with cell sizes of 26.5, 50, 100 and 150 cm³ filled with Plantmax HA organic substrate. Bare root transplants (control were produced in a closed soilless system using sand as substrate. A randomized block design was used, with four replicates with 16 plants per plot. Bare root transplants and plug transplants from 100-cm³ cells had larger crown and higher leaf and root dry mass. Early fruit yield was higher in plants propagated from plugs than in those propagated from bare root transplants. Spring and total fruit yield did not differ among treatments, with an average yield of 435 and 874 g per plant, respectively. Earlier strawberry fruit yield was obtained by using plug transplants, even from trays with small cells of 26.5 or 50 cm³.O objetivo deste trabalho foi avaliar a influência do tamanho das células utilizadas na produção de mudas de morangueiro em bandejas, comparadas a mudas de raízes nuas, quanto ao tamanho inicial da planta, período de colheita e produção total de frutos. As mudas em bandejas foram produzidas a partir de pontas de estolões enraizadas em células de 26,5, 50, 100 e 150 cm³, com o substrato orgânico Plantmax HA. As mudas de raízes nuas (controle foram produzidas em um sistema sem solo com areia como substrato. O delineamento experimental foi o de blocos ao acaso, com quatro repetições de 16 plantas. As mudas de bandejas com células de 100 cm³ e de raízes nuas atingiram diâmetro da coroa e massa de matéria seca de folhas e raízes mais elevadas. A produção precoce foi maior nas plantas propagadas por estolões que naquelas propagadas por raízes nuas. A produção de primavera e a total não diferiram entre

  18. Pattern formation - Instabilities in sand ripples

    DEFF Research Database (Denmark)

    Hansen, J. L.; v. Hecke, M.; Haaning, A.

    2001-01-01

    Sand ripples are seen below shallow wavy water and are formed whenever water oscillates over a bed of sand. Here we analyse the instabilities that can upset this perfect patterning when the ripples are subjected to large changes in driving amplitude or frequency, causing them to deform both...

  19. Pilot Project Sand Groynes Delfland Coast

    NARCIS (Netherlands)

    Hoekstra, R.; Walstra, D.J.R.; Swinkels, C.S.

    2012-01-01

    In October and November 2009 a pilot project has been executed at the Delfland Coast in the Netherlands, constructing three small sandy headlands called Sand Groynes. Sand Groynes are nourished from the shore in seaward direction and anticipated to redistribute in the alongshore due to the impact of

  20. Silica sand resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Westerhoff, W.E.; Menkovic, A.; Gruijters, S.H.L.L.; Dubelaar, C.W.; Maljers, D.

    2009-01-01

    Silica sand, (almost) pure quartz sand, is a valuable and scarce mineral resource within the shallow Dutch subsurface. High-grade deposits are exploited in the southeastemmost part of the country, as raw material for the glass, ceramic, chemical and other process industries. Dutch land-use policy re

  1. Pilot Project Sand Groynes Delfland Coast

    NARCIS (Netherlands)

    Hoekstra, R.; Walstra, D.J.R.; Swinkels, C.S.

    2012-01-01

    In October and November 2009 a pilot project has been executed at the Delfland Coast in the Netherlands, constructing three small sandy headlands called Sand Groynes. Sand Groynes are nourished from the shore in seaward direction and anticipated to redistribute in the alongshore due to the impact of

  2. Understanding Colombian Amazonian white sand forests

    NARCIS (Netherlands)

    Peñuela-Mora, M.C.

    2014-01-01

    Although progress has been made in studies on white sand forests in the Amazon, there is still a considerable gap in our knowledge of the unique species composition of white sand forests and their structure and dynamics, especially in Western Amazon. This thesis aims to fill this gap by addressing t

  3. Sand transportation and reverse patterns over leeward face of sand dune

    Science.gov (United States)

    Jiang, Hong; Dun, Hongchao; Tong, Ding; Huang, Ning

    2017-04-01

    Sand saltation has complex interactions with turbulent flow and dune form. Most models of wind-blown sand consider ideal circumstances such as steady wind velocity and a flat surface, and the bulk of data on wind flow and sand transport over an individual dune has focused mostly on the influence of dune shape or inter-dune space on the wind flow, neglecting the effect of morphology on sand saltation, particularly airflow and sand transportation over the leeward slope. Wind flow structures over the leeward slope of sand dunes have a fundamental influence on the organization of sand dunes. In order to understand sand dune dynamics, lee face airflow and sediment transportation should be paid more attention. Previous field observations could not measure turbulent flow structure well because of the limited observation points and the influence of experiment structure on wind field. In addition, the reverse sand particles over leeward face could not be collected by sand trap in field. Numerous field observations could not measure turbulent flow structure because of the limited observation points and the influence of experimental structures on the wind field. In addition, the reverse transport of sand particles over leeward face could not be collected by sand traps in field. Therefore, this paper aims to investigate the turbulent flow structure and sand transport pattern over the leeward slope. A numerical model of sand saltation over slope terrain is constructed, which also considers the coupling effects between air flow and sand particles. The large eddy simulation method is used to model turbulent flow. Sand transport is simulated by tracking the trajectory of each sand particle. The results show that terrain significantly alters the turbulent air flow structure and wind-blown sand movement, especially over the leeward slope. Here, mass flux increases initially and then decreases with height in the reversed flow region in the direction of wind flow, and the mass flux

  4. Choosing an optimum sand control method

    Directory of Open Access Journals (Sweden)

    Ehsan Khamehchi

    2015-06-01

    Full Text Available Formation sand control is always one of the main concerns of production engineers. There are some different methods to prevent sand production. Choosing a method for preventing formation sand production depends on different reservoir parameters and politic and economic conditions. Sometimes, economic and politic conditions are more effective to choose an optimum than reservoir parameters. Often, simultaneous investigation of politic and economic conditions with reservoir parameters has different results with what is expected. So, choosing the best sand control method is the result of thorough study. Global oil price, duration of sand control project and costs of necessary equipment for each method as economic and politic conditions and well productivity index as reservoir parameter are the main parameters studied in this paper.

  5. Altitude of the top of the Sparta Sand and Memphis Sand in three areas of Arkansas

    Science.gov (United States)

    Pugh, Aaron L.; Westerfield, Paul W.; Gonthier, Gerard; Poynter, David T.

    1998-01-01

    The Sparta Sand and Memphis Sand form the second most productive aquifer in Arkansas. The Sparta Sand and Memphis Sand range in thick- ness from 0 to 900 feet, consisting of fine- to medium-grained sands interbedded with layers of silt, clay, shale, and minor amounts of lignite. Within the three areas of interest, the top surface of the Sparta Sand and Memphis Sand dips regionally east and southeast towards the axis of the Mississippi Embayment syncline and Desha Basin. Local variations in the top surface may be attributed to a combination of continued development of structural features, differential compaction, localized faulting, and erosion of the surface prior to subsequent inundation and deposition of younger sediments.

  6. Sand Failure Mechanism and Sanding Parameters in Niger Delta Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Sunday Isehunwa,

    2010-05-01

    Full Text Available Sand production is a major issue during oil and gas production from unconsolidated reservoirs. In predicting the onset of sand production, it is important to accurately determine the failure mechanism and the contributing parameters. The aim of this study was to determine sand failure mechanism in the Niger-Delta, identify themajor contributing parameters and evaluate their effects on sanding.Completion and production data from 78 strings completed on 22 reservoirs in a Niger Delta oil Field were evaluated. Sand failure mechanisms and contributing parameters were identified and compared with published profiles. The results showed that cohesive stress is the predominant sand failure mechanism. Water cut, bean size and gas oil ratio (GOR impact sand production in the Niger Delta.

  7. Efficacy of play therapy

    African Journals Online (AJOL)

    User

    healing process, to improve the academic performance, increase the attentive level, and to ensure ... Goodman's Strengths and Difficulties Questionnaire-a standardized instrument) were obtained from 17 children ... Psychology Department E-mail:brexnigussie83@yahoo.com ... sand, music, movement, drama therapy, etc.

  8. Global sand trade is paving the way for a tragedy of the sand commons

    Science.gov (United States)

    Torres, A.; Brandt, J.; Lear, K.; Liu, J.

    2016-12-01

    In the first 40 years of the 21st century, planet Earth is highly likely to experience more urban land expansion than in all of history, an increase in transportation infrastructure by more than a third, and a great variety of land reclamation projects. While scientists are beginning to quantify the deep imprint of human infrastructure on biodiversity at large scales, its off-site impacts and linkages to sand mining and trade have been largely ignored. Sand is the most widely used building material in the world. With an ever-increasing demand for this resource, sand is being extracted at rates that far exceed its replenishment, and is becoming increasingly scarce. This has already led to conflicts around the world and will likely lead to a "tragedy of the sand commons" if sustainable sand mining and trade cannot be achieved. We investigate the environmental and socioeconomic interactions over large distances (telecouplings) of infrastructure development and sand mining and trade across diverse systems through transdisciplinary research and the recently proposed telecoupling framework. Our research is generating a thorough understanding of the telecouplings driven by an increasing demand for sand. In particular, we address three main research questions: 1) Where are the conflicts related to sand mining occurring?; 2) What are the major "sending" and "receiving" systems of sand?; and 3) What are the main components (e.g. causes, effects, agents, etc.) of telecoupled systems involving sand mining and trade? Our results highlight the role of global sand trade as a driver of environmental degradation that threatens the integrity of natural systems and their capacity to deliver key ecosystem services. In addition, infrastructure development and sand mining and trade have important implications for other sustainability challenges such as over-fishing and global warming. This knowledge will help to identify opportunities and tools to better promote a more sustainable use

  9. The Analysis of Distillation Tray Column Efficiency by Fluid Dynamics and Mass Transfer Computation%利用计算流体力学及计算传质的方法研究精馏塔传质效率

    Institute of Scientific and Technical Information of China (English)

    刘春江; 袁希钢; 余国琮

    2005-01-01

    It has long been found that the flow pattern of the liquid phase on distillation tray is of great importance on distillation process performance. But until now, there was very few published work on quantitative investigation of this subject. By combining the computational fluid dynamics (CFD) with the mass transfer equation, a heoreticalmodel is proposed for predicting the details of velocity and concentration distributions as well as the tray efficiency of distillation tray column. Using the proposed model, four different cases corresponding to different assumptions of liquid and vapor flowing condition for a distillation tray column were investigated. In Case I, the distributions of velocity and concentration of the incoming liquid from the downcomer and the uprising vapor from the underneath tray spacing are uniform. In Case Ⅱ, the distribution of the incoming liquid is non-uniform but the uprising vapor is uniform. In Case Ⅲ, the distribution of the incoming liquid is uniform but the uprising vapor is non-uniform.In Case Ⅳ, the distributions of both the incoming liquid and the uprising vapor are non-uniform. The details of velocity and concentration distributions on a multiple sieve tray distillation column in four different cases were simulated using the proposed model. It is found that the shape of the simulated concentration profiles of vapor and the liquid is quite different from case to case. The computed results also show that the tray efficiency is highly reduced by the maldistribution of velocity and concentration of the incoming liquid and uprising vapor. The tray efficiency for Case I is higher than Case Ⅱ or Case Ⅲ, and that for Case Ⅳ is the lowest. It also reveals that the accumulated effect of maldistribution becomes more pronounced when the number of column trays increased. The present study demonstrates that the use of computational method to predict the mass transfer efficiency for the tray column, especially for the large one, is

  10. Adsorption of dyes on Sahara desert sand.

    Science.gov (United States)

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures.

  11. Critical state of sand matrix soils.

    Science.gov (United States)

    Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

    2014-01-01

    The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803-0.998, 0.144-0.248, and 1.727-2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated.

  12. Sand Flies and Their Control Methods.

    Science.gov (United States)

    Çetin, Hüseyin; Özbel, Yusuf

    2017-06-01

    The main aim of managing arthropod vectors that carry the disease agents is interrupting the infection cycle. Therefore, the management of the disease implies that all precautions related to all elements (i.e., human, arthropod vector, and reservoir) in the infection cycle need to be taken. There are important points that need to be considered while dealing with sand flies (Diptera: Psychodidae: Phlebotominae), which in many regions worldwide, particularly in tropical and subtropical areas, are vectors of diseases such as leishmaniasis and sand fly fever and are the arthropods of the infection cycle. Because the larval control of the sand flies is very difficult and almost impossible, the management is mainly conducted for the adults. The most effective strategy for reducing both sand fly fever and leishmaniasis is managing sand flies, particularly in areas where humans are located. In this review, the morphology, biology, and taxonomy of sand flies; the integrated fighting and management methods such as insecticide-impregnated bed nets and use of curtains, zooprophylaxis, indoor and outdoor residual applications, larvicides, repellents, and insecticide-impregnated dog collars; and data regarding many issues such as insecticide resistance in sand flies have been emphasized on in the review.

  13. Critical State of Sand Matrix Soils

    Directory of Open Access Journals (Sweden)

    Aminaton Marto

    2014-01-01

    Full Text Available The Critical State Soil Mechanic (CSSM is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803–0.998, 0.144–0.248, and 1.727–2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated.

  14. Invasive plants on disturbed Korean sand dunes

    Science.gov (United States)

    Kim, Kee Dae

    2005-01-01

    The sand dunes in coastal regions of South Korea are important ecosystems because of their small size, the rare species found in this habitat, and the beautiful landscapes they create. This study investigated the current vegetative status of sand dunes on three representative coasts of the Korean peninsula, and on the coasts of Cheju Island, and assessed the conditions caused by invasive plants. The relationships between the degree of invasion and 14 environmental variables were studied. Plots of sand dunes along line transects perpendicular to the coastal lines were established to estimate vegetative species coverage. TWINSPAN (Two-Way Indicator Species Analysis), CCA (Canonical Correspondence Analysis), and DCCA (Detrended Canonical Correspondence Analysis) were performed to classify communities on sand dunes and assess species composition variation. Carex kobomugi, Elymus mollis, and Vitex rotundifolia were found to be the dominant species plotted on the east, the west, and the peripheral coasts of Cheju Island, respectively. Vegetation on the south coast was totally extinct. The 19 communities, including representative C. kobomugi, C. kobomugi- Ixeris repens, C. kobomugi- Oenothera biennis, E. mollis, Lolium multiflorum- Calystegia soldanella, and V. rotundifolia- C. kobomugi, were all classified according to TWINSPAN. Oenothera biennis and L. multiflorum were exotics observed within these native communities. CCA showed that invasive native and exotic species distribution was segregated significantly, according to disturbance level, exotic species number, gravel, sand and silt contents, as well as vegetation size. It further revealed that human disturbance can strongly favor the settlement of invasive and exotic species. Restoration options to reduce exotic plants in the South Korean sand dune areas were found to be the introduction of native plant species from one sand dune into other sand dune areas, prohibition of building and the introduction of exotic

  15. An Innovative Rigid Tray Technique as a New Alternative Matrix System for Buildup of Severely Damaged Endodontically Treated Teeth (A Case Report

    Directory of Open Access Journals (Sweden)

    Saied Mostafa Moazzami

    2014-09-01

    Full Text Available Direct restoration of severely damaged endodontically treated teeth (ETT using available and conventional and current matrix systems is sometimes impractical and in some clinical cases is impossible. The aim of this paper is to introduce and describe a new matrix system based on Rigid Tray Technique (RTT for dealing with such difficult clinical cases.

  16. A comparative evaluation of tray spacer thickness and repeat pour on the accuracy of monophasic polyvinyl siloxane impression material: In vitro study

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2014-01-01

    Full Text Available Purpose: This study was aimed to determine the effect of various tray spacer thickness and subsequent repeated pours on the accuracy and dimensional stability of the impression made from monophasic polyvinyl siloxane material. Materials and Methods: Custom trays with different spacer thickness (2, 4 and 6 mm were used for making an impression of a master model simulating 3 unit fixed partial denture with monophasic polyvinyl siloxane material. These impressions were poured with die stone and repoured. Distance between the reference points were measured and subjected to statistical analysis. Result: Casts obtained from 1 st , 2 nd and 3 rd pour of the impression in 2, 4 and 6 mm spacer thickness tray have similar dimensional accuracy amongst each other and with the master model except in molar diameter and inter-abutment distances of cast obtained from 6 mm spacer thickness tray. Conclusion: The vertical distance of stone dies were decreased, whereas horizontal distance increased as the thickness of impression material is increased. There were statistically non-significant changes occurring among the repeated pours in 2, 4 and 6 mm spacer thickness. Clinical Implication: 2 and 4 mm spacer thickness are acceptable for making an impression for three unit fixed partial denture with monophasic polyvinyl siloxane material and it was not affected by two subsequent (1 st and 2 nd repeated pours.

  17. Reliability and accuracy of real-time visualization techniques for measuring school cafeteria tray waste: validating the quarter-waste method.

    Science.gov (United States)

    Hanks, Andrew S; Wansink, Brian; Just, David R

    2014-03-01

    Measuring food waste is essential to determine the impact of school interventions on what children eat. There are multiple methods used for measuring food waste, yet it is unclear which method is most appropriate in large-scale interventions with restricted resources. This study examines which of three visual tray waste measurement methods is most reliable, accurate, and cost-effective compared with the gold standard of individually weighing leftovers. School cafeteria researchers used the following three visual methods to capture tray waste in addition to actual food waste weights for 197 lunch trays: the quarter-waste method, the half-waste method, and the photograph method. Inter-rater and inter-method reliability were highest for on-site visual methods (0.90 for the quarter-waste method and 0.83 for the half-waste method) and lowest for the photograph method (0.48). This low reliability is partially due to the inability of photographs to determine whether packaged items (such as milk or yogurt) are empty or full. In sum, the quarter-waste method was the most appropriate for calculating accurate amounts of tray waste, and the photograph method might be appropriate if researchers only wish to detect significant differences in waste or consumption of selected, unpackaged food.

  18. Sanitation Can Be A Foundation Disease Management Tool: Potential Of Spreading Binucleate Rhizoctonia from Nursery Propagation Floors To Trays Containing Azalea Stem Cuttings

    Science.gov (United States)

    Binucelate Rhizoctonia spp. (BNR), the cause of web blight, are present all year on container-grown azaleas in the southern U.S. BNR can be eliminated during vegetative propagation by submerging stem cuttings in 50°C water for 21 minutes. The objective was to evaluate risk of rooting trays being con...

  19. Evaluation of the Thickness and Oxygen Transmission Rate before and after Thermoforming Mono- and Multi-layer Sheets into Trays with Variable Depth

    Directory of Open Access Journals (Sweden)

    Mieke Buntinx

    2014-12-01

    Full Text Available During thermoforming, plastic sheets are heated and subsequently deformed through the application of mechanical stretching and/or pressure. This process directly impacts sheet properties such as material thickness in walls, corners, and bottom, crystallinity in the constituent layers, and particularly the oxygen gas permeability. The aim of this study was to quantify the impact of thermoforming on thickness and oxygen transmission rate (OTR of selected packaging materials (polypropylene (PP; PP/ethylene-vinyl alcohol co-polymer/PP (PP/EVOH/PP; polystyrene/EVOH/polyethylene (PS/EVOH/PE; amorphous polyethylene terephtalate/PE (APET/PE; APET/PE/EVOH/PE; polyamide/PE (PA/PE; and (PE/PA/EVOH/PA/PE. These materials were extruded in two different thicknesses and thermoformed into trays with the same top dimensions and variable depths of 25, 50, and/or 75 mm and a 50 mm tray with a variable radius of the corners. The distribution of the material thickness in the trays was visualized, showing the locations that were most affected by the deep drawn process. The OTR results indicate that the calculated OTR, based on a homogeneous material distribution, can be used as a rough approximation of the measured OTR. However, detailed analysis of crystallization and unequal thinning, which is also related to the tray design, remains necessary to explain the deviation of the measured OTR as compared to the predicted one.

  20. Formation mechanism of cracks in saturated sand

    Institute of Scientific and Technical Information of China (English)

    Xiaobing Lu; Zhemin Zheng; Yongren Wu

    2006-01-01

    The formation mechanism of "water film" (or crack) in saturated sand is analyzed theoretically and numerically.The theoretical analysis shows that there will be no stable "water film" in the saturated sand if the strength of the skeleton is zero and no positions are choked.It is shown by numerical simulation that stable water films initiate and grow if the choking state keeps unchanged once the fluid velocities decrease to zero in the liquefied sand column.The developments of "water film" based on the model presented in this paper are compared with experimental results.

  1. Lund Sand No 0:part 2

    OpenAIRE

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    1996-01-01

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. T...

  2. Lund Sand No 0:part 1

    OpenAIRE

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    1996-01-01

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. T...

  3. Biodegradable materials as foundry moulding sands binders

    Directory of Open Access Journals (Sweden)

    K. Major - Gabryś

    2015-07-01

    Full Text Available The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved ability to reclamation as well as in accelerated biodegradation of binding material leftovers of mechanical reclamation.

  4. Watching Faults Grow in Sand

    Science.gov (United States)

    Cooke, M. L.

    2015-12-01

    Accretionary sandbox experiments provide a rich environment for investigating the processes of fault development. These experiments engage students because 1) they enable direct observation of fault growth, which is impossible in the crust (type 1 physical model), 2) they are not only representational but can also be manipulated (type 2 physical model), 3) they can be used to test hypotheses (type 3 physical model) and 4) they resemble experiments performed by structural geology researchers around the world. The structural geology courses at UMass Amherst utilize a series of accretionary sandboxes experiments where students first watch a video of an experiment and then perform a group experiment. The experiments motivate discussions of what conditions they would change and what outcomes they would expect from these changes; hypothesis development. These discussions inevitably lead to calculations of the scaling relationships between model and crustal fault growth and provide insight into the crustal processes represented within the dry sand. Sketching of the experiments has been shown to be a very effective assessment method as the students reveal which features they are analyzing. Another approach used at UMass is to set up a forensic experiment. The experiment is set up with spatially varying basal friction before the meeting and students must figure out what the basal conditions are through the experiment. This experiment leads to discussions of equilibrium and force balance within the accretionary wedge. Displacement fields can be captured throughout the experiment using inexpensive digital image correlation techniques to foster quantitative analysis of the experiments.

  5. Evaluation of the Pseudalert/Quanti-Tray MPN Test for the Rapid Enumeration of Pseudomonas aeruginosa in Swimming Pool and Spa Pool Waters.

    Science.gov (United States)

    Sartory, David P; Brewer, Megan; Beswick, Agnieszka; Steggles, Darron

    2015-12-01

    This study assessed the performance of a new most probable number test (Pseudalert/Quanti-Tray) for the enumeration of Pseudomonas aeruginosa from swimming pool and spa pool waters by comparing it to the international and national membrane filtration-based culture methods for P. aeruginosa: ISO 16266:2006 and UK The Microbiology of Drinking Water-Part 8 (MoDW Part 8) which both use Pseudomonas CN agar. The comparison was based on the calculation of mean relative differences between the two methods conducted according to ISO 17994:2014. Using both routine pool water samples (149 from 8 laboratories) and artificially contaminated samples (309 from 7 laboratories), paired counts from each sample and enumeration method were analysed. For routine samples, there were insufficient data for a conclusive assessment, but the data do indicate at least equivalent performance of Pseudalert/Quanti-Tray to the reference methods. For the artificially contaminated samples, the data also did not result in a statistically conclusive assessment but did indicate potentially better performance of Pseudalert/Quanti-Tray. Combining the data from the routine samples and artificially contaminated samples resulted in an ISO 17994 outcome that the two methods were not statistically significantly different. Thus, the Pseudalert/Quanti-Tray method is an acceptable alternative to ISO 16266 and MoDW Part 8. The Pseudalert/Quanti-Tray method has the advantage in that it does not require confirmation testing, and of providing confirmed counts within 24-28 h incubation compared to 40-48 h or longer for the ISO 16266 and MoDW Part 8 methods.

  6. Comparison between a spray column and a sieve tray column operating as liquid-liquid heat exchangers

    Science.gov (United States)

    Keller, A. S.; Jacobs, H. R.; Boehm, R. F.

    The reported investigation was conducted in connection with research intended to improve the efficiency of direct contact devices for geothermal and solar applications. The investigation had the objective to evaluate the effect of adding sieve trays to the laboratory column used in studies concerned with the development of models for spray column heat transfer. Hot water is pumped from a supply vessel into the top of the heat exchanger column where, as the continuous phase, it flows down through the column. The dispersed phase is kerosene. Using an identical pump to that used for the water, the kerosene flows into a dispersion plate in the bottom of the column. The droplets rise through the column and coalesce at the top. It was found that the heat transfer performance of the perforated plate column was significantly improved over that in a spray column for similar operating conditions.

  7. Generation and detection of pulsed T-rays for use in the study of biological and bioterrorism issues

    Science.gov (United States)

    Jedju, Thomas M.; Bosacchi, Bruno; Warren, Warren S.; Nahata, Ajay; Kuenstner, Todd

    2004-09-01

    Terahertz (T-rays) spectroscopy has recently emerged as a powerful method to access a heretofore barely explored region of the electromagnetic spectrum where fundamental molecular resonances occur. Besides their importance for fundamental research, these resonances could be used as signatures in the identification of molecular species and as sensitive probes in a wide variety of molecular processes. In this paper we consider the potential of THz spectroscopy in the application to relevant biomedical and homeland security problems such as the analysis of normal and diseased tissues and the detection of toxic biomolecules. As examples, we present preliminary experimental data which suggest that THz spectroscopy: 1) can discriminate between cancerous and normal tissue, and 2) can reveal the presence of foreign substances hidden in an envelope and even allow their specific identification. This capability is of particular relevance as a straightforward homeland security tool for the detection of anthrax and other biotoxic molecules.

  8. A sectional-splinting technique for impressing multiple implant units by eliminating the use of an open tray

    Directory of Open Access Journals (Sweden)

    Suryakant C. Deogade

    2014-01-01

    Full Text Available Since the inception of root form implant dentistry by P-I Branemark in the early 1980′s, so many technical advances have been put forward by several authors. However, the open tray impression technique is still performed for impressing multiple implant fixtures as it was first described in the original Branemark procedure manual. The most critical aspect for a successful implant-supported restoration is the passive and an accurate fit of superstructures to avoid preload and loading stresses. Splinting impression technique in multiple implants has gained popularity. Auto-polymerizing acrylic resin is among the most routinely practiced splinting material for multiple implant units. However, unfortunately, it exhibits shrinkage, which makes an impression quite inaccurate. This case report presents the solution to minimize the shrinkage of resin by utilizing sectional-splinting technique as advocated in the previous implant literature.

  9. Effect of Chromite-Silica Sands Characteristics on Performance of Ladle Filler Sands for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Free opening rate is mainly determined by the performance of the ladle filler sand. High free opening rates of ladles are required in steel making to improve steel quality. Chromite ladle filler sands are one of the most widely used ladle filler sand. Several operative variables and materials characteristics affect the performance of the sands. Three sets of chromite ladle filler sands were selected and researches were focused on the sintering hehaviour and per- formance of the sands under operative conditions. The effect of particle size distribution on sintering, microstruc- ture, flowability, and permeability were presented. In all cases, the particle size varies from 0.1 to 1.5 mm corre- sponding to free flowing powders. One of the samples has higher permeability factor in comparison with others due to low particle size distribution. The other sample presents very good free opening due to its very good flowability and permeability factor.

  10. Accuracy of implant transfer and surface detail reproduction with polyether and polyvinyl siloxane using closed-tray impression technique

    Directory of Open Access Journals (Sweden)

    Marzieh Alikhasi

    2013-10-01

    Full Text Available   Background and Aims: Making accurate impressions of prepared teeth when they are adjacent to dental implants is of great importance. In these situations, disregarding the selection of appropriate impression material and technique, not only can affect accuracy of transferring of the 3-dimentional spatial status of implant, but also can jeopardize the accurate recording of tooth. In the present study, the accuracy of two impression materials with taper impression copings for recording implant position and surface details was evaluated.   Materials and Methods: One metal reference model with 2 implants (Implantium and a preparation of three grooves on a tooth according to ADA no. 19 standard was fabricated. 10 medium- consistency polyEther (PE impressions using custom trays and 10 polyVinyl Siloxane (PVS putty wash impressions using prefabricated trays with conical impression coping were made. Impressions were poured with ADA type IV stone. A Coordinate Measuring Machine (CMM evaluated x, y and angular displacement of the implant analog heads and also accuracy of groove reproduction were measured using a Video Measuring Machine (VMM. These measurements were compared to the ones from reference model. Data were analyzed using one-way ANOVA and T-test.   Results: Putty wash PVS had less linear discrepancy compared with reference model (P > 0.001. There was no significant difference in the surface detail reproduction (P = 0.15.   Conclusion: Putty wash PVS had better results for linear displacement compared with medium consistency PE. There was no significant difference in surface detail reproduction between the two impression materials.

  11. Clinical study of the safety and effectiveness of a novel over-the-counter bleaching tray system

    Directory of Open Access Journals (Sweden)

    Ghalili KM

    2014-02-01

    Full Text Available K Michael Ghalili,1 Kamal Khawaled,2 Doran Rozen,2 Veda Afsahi3 1Department of Prosthodontics, New York University College of Dentistry, New York, NY, USA; 2Department of R&D; Department of Clinical Affairs, Syneron Beauty, Ltd, Yokneam, Israel; 3Veda Faith Afsahi Inc., Fountain Valley, CA, USA Abstract: We investigated color change, gingival irritation, and tooth sensitivity in patients undergoing at-home vital tooth bleaching with a novel over-the-counter bleaching tray system. Tooth color shade in anterior teeth, supragingival plaque and gingivitis in Ramfjord teeth, as well as visual assessment of teeth gingival tissues and mucosa were evaluated in-office prior to treatment, after two consecutive applications of the 9% hydrogen peroxide bleaching product, after eight applications (10 minutes/day for 3 days at home, and after ten applications (50 minutes exposure over 5 days. Color stability was evaluated at 3 months after completing the treatment regimen. Over-the-counter bleaching products can be used by the patient at home without dentist supervision, but are frequently associated with gingival irritation and tooth sensitivity despite low concentrations of peroxide agents. Our investigations showed that the treatment is tolerable and safe with a low incidence of adverse effects. Any adverse effects associated with use of the whitening gel and tray are temporary, easily controlled, and often disappear within minutes of treatment. Statistical analysis revealed significant improvement in teeth whitening following treatment (mean color change of seven shades and at three months after treatment. Keywords: at home tooth-whitening, hydrogen peroxide teeth whitening, over-the-counter tooth-whitening, teeth bleaching

  12. Sand Lake WMD vegetation mapping project update

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Final report on the vegetation mapping project at Sand Lake Wetland Management District. This project is being completed by the use of SPRING software and ground...

  13. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    Global applications of pesticides in agricultural production have led to the detection of trace amounts of pesticides in groundwater resources in levels exceeding the EU threshold limit for drinking water of 0.1 µg L-1. Pesticide-polluted groundwater may be remediated by inoculating waterworks sand...... for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...

  14. Petrophysical Analysis of Oil Sand in Athabasca

    Science.gov (United States)

    cheong, S.; Lee, H.

    2013-12-01

    Oil sands are the major unconventional energy sources which have great reserves in Alberta, Canada. Recovery techniques such as CSS (Cyclic Steam Stimulation) and SAGD (Steam Assisted Gravity Drainage) enabled to develop deeper bitumen about several hundred meter depth. Before applying CSS and SAGD, reservoir heterogeneity of mud barriers or shale breccias should be clarified to establish injection and production wells successfully. We conducted the integrated petro-physical analysis for oil sands deposits in Athabasca by correlating well logs with seismic data. From 33 well logs and 3D seismic, we have made P-wave impedance by recursive inversion. Target formations of our analysis were the top of Wabiskaw member. Using inverted impedance and multi-attributes, porosity volume was derived at a target depth. Porosity of time slice 375 ms ranged 20 ~ 40 % stretching porous sand body from NE to SW direction. Characteristics of porosity distribution may be useful to design optimum oil sands recovery in Athabasca.

  15. Carbon cycle: New pathways in the sand

    Science.gov (United States)

    Rao, Alexandra

    2017-01-01

    Organic carbon decomposition in anoxic marine sediments was thought to be dominated by bacteria, but experimental data and microbial culture studies now show that microalgae buried in coastal sands may also play an important role in carbon turnover.

  16. CRADE OF SAND AND DUST STORM WEATHER

    Institute of Scientific and Technical Information of China (English)

    Niu Ruoyun; Tian Cuiying; Bi Baogui; Yang Keming; Wang Youheng; Tuo Ya; Ding Haifang; Zhang Tairen

    2011-01-01

    Background Sand and dust storm,as one of the main disastrous weathers that affect northern China,not only affect the people health and normal life,but cause the short-term climatic changes due to the direct and indirect radiation of the earth-atmosphere system through the dust floating in the sky.The sand end dust weather and its potential harm on the national economy,ecological environment,social activities and other aspects have aroused worldwide concern.

  17. Laboratory evaluation of selected tar sand asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  18. Response to Oil Sands Products Assessment

    Science.gov (United States)

    2015-09-01

    Tailings ponds are an operating facility common to all types of surface mining. For oil sands, tailings consisting of water , sand, clay, and residual ...oil, are pumped to these basins—or ponds— where settling occurs and water is recycled for reuse in the process. When the ponds are no longer required...of crude oil transported by tank vessel in Washington waters . In a 2013 Bloomburg Business news article , Dan Murtaugh states, “The dock probably

  19. Treating tar sands formations with dolomite

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

    Methods for treating a tar sands formation are described herein. The tar sands formation may include dolomite and hydrocarbons. Methods may include providing heat at less than the decomposition temperature of dolomite from one or more heaters to at least a portion of the formation. At least some of the hydrocarbon fluids are mobilized in the formation. At least some of the hydrocarbon fluids may be produced from the formation.

  20. Pragmatics of reclaimed sand quality assessment recovered nowadays from various used sand systems

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2010-04-01

    Full Text Available The assessment of the reclamation degree of used sands is not a simple, clearly defined issue. The great variety of technologies ofmoulding and core sands, based on the organic and inorganic binders does not allow the use of a single, universal index assessing thedegree of reclamation. The article presents the problems of research relating to selection of proper criteria for assessing the degree ofreclamation process of used moulding and core sands deriving from different technologies. The most often applied in practice types ofused sands and the most adequate in practice methods of assessing the degrees of their reclamation were characterized.

  1. Sand Dune Encroachment and Desertification Processes of the Rigboland Sand Sea, Central Iran.

    Science.gov (United States)

    Ahmady-Birgani, Hesam; McQueen, Kenneth G; Moeinaddini, Mazaher; Naseri, Hamidreza

    2017-05-08

    Early studies on sand dune movement and desertification in Iran have not always been convincingly demonstrated because of problems with the field-based measurements. In some areas where various land uses have been engulfed by aeolian sand dunes, desertification is clear, but in other less settled areas, it may not be so obvious. The objective of this study is to demonstrate encroachments of the Rigboland sand sea, central Iran, in its different directions and variable magnitude rates. Determining the rate and direction of the sand sea movements is critical for specifying which lands should be prioritized and quickly protected. The study has trialed a change detection technique which uses a Cross-Tabulation module to compare two available LandsatTM images over the Rigboland sand sea. This indicates that within a ten-year span (from 1988 to 1998) more than 200 ha/yr were added to the Rigboland sand sea, from the alluvial fan landforms in the eastern upstream, outer margins of the Rigboland sand sea. Coupled with GIS techniques, this type of analysis of the remote sensing (RS) images provides an effective tool for the monitoring and prognostication of sand dune movement and sand sea change.

  2. Analysis of sand particles' lift-off and incident velocities in wind-blown sand flux

    Institute of Scientific and Technical Information of China (English)

    Tian-Li Bo; Xiao-Jing Zheng; Shao-Zhen Duan; Yi-Rui Liang

    2013-01-01

    In the research of windblown sand movement,the lift-off and incident velocities of saltating sand particles play a significant role in bridging the spatial and temporal scales from single sand particle's motion to windblown sand flux.In this paper,we achieved wind tunnel measurements of the movement of sand particles near sand bed through improving the wind tunnel experimental scheme of paticle image velocimetry (PIV) and data processing method.And then the influence of observation height on the probability distributions of lift-off and incident velocities of sand particles was analyzed.The results demonstrate that the observation height has no obvious influence on the distribution pattern of the lift-off and incident velocities of sand particles,i.e.,the probability distribution of horizontal and vertical velocities of lift-off and incident sand particles follow a Gaussian distribution and a negative exponential distribution,respectively.However,it influences the center of the Gaussian distribution,the decay constant and the amplitude of the negative exponential distribution.

  3. Recent Sand Avalanching on Rabe Crater Dunes

    Science.gov (United States)

    2000-01-01

    Dark streaks on the steep, down-wind slopes of sand dunes in Rabe Crater are seen at several locations in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. These streaks indicate relatively recent (i.e., in the past few years or less) movement of sand down these slopes.Sand dunes move forward by the combined action of wind that drives sand up the shallow slope on the windward side of the dune (in this case, the slopes that face toward the lower right) and the avalanching of this sand down the steeper, lee-side slope. The steep slope is also known as the slip face. The dark streaks indicated by arrows are evidence for sand avalanches that occurred within a few months or years of the time when the picture was taken in March 1999. Other streaks which are seen criss-crossing the dunes may be the result of passing dust devils. This image is illuminated from the upper left and located in Rabe Crater of the Hellespontus-Noachis region near 44.2oS, 325.6oW.

  4. Discrete particle simulation of mixed sand transport

    Institute of Scientific and Technical Information of China (English)

    Fengjun Xiao; Liejin Guo; Debiao Li; Yueshe Wang

    2012-01-01

    An Eulerian/Lagrangian numerical simulation is performed on mixed sand transport.Volume averaged Navier-Stokes equations are solved to calculate gas motion,and particle motion is calculated using Newton's equation,involving a hard sphere model to describe particle-to-particle and particle-to-wall collisions.The influence of wall characteristics,size distribution of sand particles and boundary layer depth on vertical distribution of sand mass flux and particle mean horizontal velocity is analyzed,suggesting that all these three factors affect sand transport at different levels.In all cases,for small size groups,sand mass flux first increases with height and then decreases while for large size groups,it decreases exponentially with height and for middle size groups the behavior is in-between.The mean horizontal velocity for all size groups well fits experimental data,that is,increasing logarithmically with height in the middle height region.Wall characteristics greatly affects particle to wall collision and makes the flat bed similar to a Gobi surface and the rough bed similar to a sandy surface.Particle size distribution largely affects the sand mass flux and the highest heights they can reach especially for larger particles.

  5. Predicting the occurrence of sand banks in the North Sea

    NARCIS (Netherlands)

    Veen, van der Henriët H.; Hulscher, Suzanne J.M.H.

    2009-01-01

    Sand banks have a wavelength between 1 and 10 km, and they are up to several tens of meters high. Also, sand banks may have an impact on large-scale human activities that take place in the North Sea like sand mining, shipping, offshore wind farms, etc. Therefore, it is important to know where sand b

  6. Layers, Landslides, and Sand Dunes

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 27 October 2003This image shows the northern rim of one of the Valles Marineris canyons. Careful inspection shows many interesting features here. Note that the spurs and gullies in the canyon wall disappear some distance below the top of the canyon wall, indicating the presence of some smooth material here that weathers differently from the underlying rocks. On the floor of the canyon, there are remains from a landslide that came hurtling down the canyon wall between two spurs. Riding over the topography of the canyon floor are many large sand dunes, migrating generally from the lower right to upper left.Image information: VIS instrument. Latitude -14.1, Longitude 306.7 East (53.3 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. Development of the Gran Desierto sand sea, northwestern Mexico

    Science.gov (United States)

    Blount, Grady; Lancaster, Nicholas

    1990-08-01

    Three major eolian sand populations can be recognized in the Gran Desierto sand sea of northwestern Mexico by using spectral data from the Landsat thematic mapper in conjunction with textural and mineralogical studies of surface sands. Each sand population has distinct textural, mineralogic, and spectral properties that can be related to sand-dune morphology and position with reference to source areas and transport paths of the sands. The oldest eolian sediment in the sand sea was derived from the early to middle Pleistocene Colorado River that flowed through the area of the western Gran Desierto. Subsequent inputs of eolian sands came from the area of the present Colorado River valley and the coast south of the sand sea. The spatial and temporal pattern of eolian deposition in the region has been controlled by Quaternary tectonic and climatic changes, resulting in the episodic input and deposition of sand.

  8. Effects of advanced oxidation on green sand properties via iron casting into green sand molds.

    Science.gov (United States)

    Wang, Yujue; Cannon, Fred S; Voigt, Robert C; Komarneni, Sridhar; Furness, J C

    2006-05-01

    The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal-sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10-15% more active clay as measured bythe standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditioned green sand with higher normalized pore volume, and thus higher normalized m-xylene adsorption capacity, i.e., relative to before-metal-pouring conditions. Furthermore, mathematical analysis indicated that the AO-conditioned green sand better retained its important properties after pouring than did the TAP-conditioned green sand. Effectively, this meant after metal pouring, the AO-conditioned sample offered about the same net properties as the TAP-conditioned sample, even though the AO-conditioned sample contained less clay and coal before metal pouring. These results conformed to the full-scale foundry empirical finding that when AO is used, foundries need less makeup clay and coal addition through each casting cycle, and they release less air emissions.

  9. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice-age deposits were reactivated as drift sand du

  10. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice–age deposits were reactivated as drift sand du

  11. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice–age deposits were reactivated as drift sand

  12. Bright sand/dark dust: The identification of active sand surfaces on the Earth and Mars

    Science.gov (United States)

    Blount, H. G., II; Greeley, R.; Christensen, P. R.; Arvidson, R.

    1987-05-01

    Field studies and analysis of LANDSAT Thematic Mapper data in the Gran Desierto, Mexico may shed light on a technique to distinguish active from inactive (relict) sand surfaces. Active sand bodies in the study area are consistently brighter (by an average of 20%) at visual and near infrared wavelengths and darker at thermal infrared wavelengths than compositionally similar inactive sands. The reasons for the albedo difference between active and inactive sands are reviewed and the mixing model of Johnson et al. is examined for tracing the provenance of sands based on albedo and spectral variations. Portions of the wavelengths covered by the Mars Orbiter correspond to the Thematic Mapper data. The identification of active sands on Earth, with a priori knowledge of bulk composition and grain size distribution, may allow the remote mapping of active sand surfaces on Mars. In conjuction with thermal infrared remote sensing for composition, it may also provide a method for the remote determination of grain size distributions within sand/silt mixtures.

  13. Simulating and understanding sand wave variation: A case study of the Golden Gate sand waves

    Science.gov (United States)

    Sterlini, F.; Hulscher, S.J.M.H.; Hanes, D.M.

    2009-01-01

    In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the opportunity to study sand wave variation between locations, within one well-measured, large area. The nonlinear model used in this paper is presently the only tool that provides information on the nonlinear evolution of large-amplitude sand waves. The model is used to increase our understanding of the coupling between the variability in environmental conditions and the sand wave characteristics. Results show that the model is able to describe the variation in the Golden Gate sand waves well when both the local oscillating tidal current and the residual current are taken into account. Current and water depth seem to be the most important factors influencing sand wave characteristics. The simulation results give further confidence in the underlying model hypothesis and assumptions. Copyright 2009 by the American Geophysical Union.

  14. MORPHOMETRIC CHARACTERIZATION OF THE SAND FRACTION IN A SAND GRAIN IMAGE CAPTURE SYSTEM1

    Directory of Open Access Journals (Sweden)

    Lucimar Arruda Viana

    Full Text Available ABSTRACT Morphology studies assume significant importance in analysis of phenomena of granular systems packaging, in particular with a view to the use of the technique of soil stabilization named particle size correction in forest roads. In this context, this study aimed to develop and operationalize a Sand Grain Image Capture System and, hereby, determine the morphological indices of the sand fractions of two sandy soils called João Pinheiro (JP and Cachoeira da Prata (CP. Soil samples, air-dried, were sieved (2.0 mm nominal mesh size for removal of gravels. The materials that passed through the sieve were subjected to dispersion, washing in 0.053 mm nominal mesh size sieve, removal of organic matter and iron oxides to obtain the clean sand fractions. Subsequently, each soil sample was sieved for separation into twelve classes, between the diameters of 0.149 mm and 1.190 mm, using a Rotap shaker. Next, tests were carried out to characterize the morphometric attributes of the twelve classes of sand fractions of the soils studied. For validation of the performance of the Sand Grain Image Capture System, the results were compared to those obtained using a standard procedure for image analysis. The analysis of the results led to the following conclusions: (i the sand fraction of the JP soil presented higher values for the morphometric indices roundness, elongation and compactness compared to sand fraction of the CP soil; and (ii the Sand Grain Image Capture System worked properly, with practicality.

  15. Probability of rebound and eject of sand particles in wind-blown sand movement

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Xiaojing Zheng

    2007-01-01

    When incident particles impact into a sand bed in wind-blown sand movement, rebound of the incident particles and eject of the sand particles by the incident particles affect directly the development of wind sand flux. In order to obtain rebound and eject lift-off probability of the sand particles, we apply the particle-bed stochastic collision model presented in our pervious works to derive analytic solutions of velocities of the incident and impacted particles in the postcollision bed. In order to describe randomness inherent in the real particle-bed collision, we take the incident angle, theimpact position and the direction of resultant action of sand particles in sand bed on the impacted sand particle as random variables, and calculate the rebound and eject velocities,angles and coefficients (ratio of rebound and eject velocity to incident velocity). Numerical results are found in accordance with current experimental results. The rebound and eject lift-off probabilities versus the incident and creeping velocities are predicted.

  16. Pretreatment of turkey fat-containing wastewater in coarse sand and gravel/coarse sand bioreactors.

    Science.gov (United States)

    Gaur, Rashmi Singh; Cai, Ling; Tuovinen, Olli H; Mancl, Karen M

    2010-02-01

    Fat, oil and grease in wastewater can be difficult to treat because of their slow decomposition. Traditional pretreatment facilities to remove fat, oil and grease from wastewater are increasingly costly. The hypothesis in this study was that pretreatment of animal fat-containing wastewater in sand and sand/gravel filters facilitates the conversion of slowly degradable organic matter measured as the difference between chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD(5)) for subsequent biological treatment. The pretreatment was evaluated using simulated turkey-processing wastewater and coarse sand and sand/gravel filters at a constant hydraulic loading rate of 132L/m(2)/day. Two types of fixed media reactors were employed: (i) one set with a varying depth of coarse sand, and (ii) the second was similar but with an additional pea gravel cap. The results indicated that the relative removal of COD was slightly improved in the sand bioreactors with a pea gravel cap irrespective of the depth of coarse sand, but partial conversion to BOD(5) was not consistently demonstrated. Pea gravel may act as a sieve to entrap organic matter including fat globules from the wastewater. Multiple dosing at the same daily loading rate slightly improved the treatment efficiency of the sand bioreactors. The ratios of influent-COD/effluent-COD were always greater than 1.0 following a change in the dosing frequency after a rest period, suggesting that organic matter, specifically fat globules in this case, was retained by the column matrix.

  17. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  18. Cleaning oil sands drilling waste in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Mikic, N.; Nilsen, C.; Markabi, M. [Mi SWACO, Calgary, AB (Canada)

    2008-07-01

    The waste generated from steam assisted gravity drainage (SAGD) wells is brought to the surface and separated by shale shakers. The waste can include drilling fluids and sand contaminated with bitumen. This paper described a new technology developed to treat waste using the addition of hot water and various mixing and separation technologies to reduce the viscosity of the bitumen and separate it from the sand. The bitumen-contaminated drill cuttings were mixed with hot water to form a slurry that was then separated through the G-force created by a hydrocyclone. A secondary separation was then conducted in an elutriation column to remove residual contaminants from the sand. The flow rate of the process was controlled by the fine solids composition of the cuttings, the temperature of the cleaning process, and the performance of the individual components. Laboratory tests conducted to tests the method showed that the sand particles produced using the method were clean enough to be safely disposed in the environment. A pilot study will be conducted to test the sand cleaning technology at a commercial scale. 6 refs., 3 figs.

  19. Mitigating in situ oil sands carbon costs

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

    2008-10-15

    Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

  20. ANALYSIS OF DEFORMED STATE STRUCTURES OF THE KYIV METRO RUNNING TUNNELS ON A TRANSITION ZONE FROM SPONDYLOV’S CLAY TO BUCHATSKIY SANDS

    Directory of Open Access Journals (Sweden)

    V. D. Petrenko

    2014-07-01

    Full Text Available Purpose. In the section of changes geotechnical conditions of spondylov’s clay to buchatskiy sands may have significant structural deformation of running tunnels. It is necessary to identify the cause of deformities develop ways to minimize and based modeling and calculations to prove the effectiveness of measures to reduce deformation.Methodology. To solve the analysis problem of the stress-strain state (SSS of the system «structure array» it was conducted the numerical simulation using the finite element method (FEM. On the basis of the obtained results the graphs were constructed and the dependencies were determined. Findings. The presence of weak water-saturated soils in tray of the tunnel on an area of transition from spondylov’s clay to buchatskiy sand causes significant increasing in strain construction of tunnels and general vibration liquefaction in soil basis. Also change the physical and mechanical characteristics of soils within the frames of tunnels influences on the level of strain state of most frames. Improved strain state settings of tunnels in areas of change soil characteristics of the array (especially at the bottom of casing can be achieved by chemical consolidation of weak soils. Composition of solutions for fixing the weak soils should be determined based on the study of grain size, porosity, and other parameters of physical and mechanical and physical and chemical characteristics of soils.Originality.The basic cause significant strain on transition zone from spondylov’s clay to buchatskiy sands is found, that is explained by saturated phenomenon vibration liquefaction basis under the tunnel.Practical value.The approaches to reduce the strain in the construction of running tunnels in the transition zone from spondylov’s clay to buchatskiy sands are developed, as well as in the area ofthe station «Glybochytska»the Kyiv Metro.

  1. Effects of Pumping Sizes on THz Radiation Based on Ultrashort Light Pulse Optical Rectification for High Spatial Resolution T-Ray Imaging

    Institute of Scientific and Technical Information of China (English)

    XU Shi-Xiang; DAI Xiao-Ming; YANG Xiao-Hua; LI Jing-Zhen

    2008-01-01

    @@ We present our experimental studies on the effects of the pumping sizes on THz radiation based on ultrashort light pulse optical rectification for high spatial resolution T-Ray imaging.Our experiments show that high spatial resolution T-ray imaging requires both thin THz emitter and sample, and rigorous tolerance of the gap between the sample and the emitter, as well as small pumping size which usually much smaller compared with THz wavelength.Such a small pumping size results in dramatic decrease of the THz wave power, which originates from strong diffraction of THz wave, the depolarization of the focused tightly pumping beam, the spatial filtering of the emitter exit-surface, and the strong phase-mismatching between the pumping and the high spatial Fourier components of the THz signal, rather than two-photon absorption.

  2. 尿素合成塔塔盘塌陷原因及修复%CAUSE FOR COLLAPSE OF TRAYS OF UREA PRILLING TOWER AND REPAIR

    Institute of Scientific and Technical Information of China (English)

    梁冬虎

    2011-01-01

    The causes for lug fracture and tray collapse in urea prilling tower are analyzed,the repair of lugs is formulated and how to ensure the installation effect of hook bolts and tray fixed bolts is discussed in order to ensure a safe operation of urea prilli%分析尿素合成塔塔盘支耳断裂和塔盘塌陷的原因,制定塔盘支耳修复方法,讨论如何保证合成塔勾头螺栓和塔盘固定螺栓的安装效果,确保尿素合成塔的安全运行。

  3. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between...... void ratio and permeability is established....

  4. Sand Dunes Fixation in Baiji District, Iraq

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This study was carried out at Sand Dunes Stabilization Researches Station in Baiji district (230 ln north of Baghdad, Iraq) to evaluate the effects of local soil conditioners manufactured from oil derivatives and plant residuals on sand dunes fixation as the first step for sand dunes stabilization. The results indicate that the fuel oil has the first place in improving wind erosion parameters in the study area, such as increasing mean weight diameter, dry aggregates percentage, the needed time for complete disaggregation by dry sieving, and decreasing the disaggregation rates. Bitumen emulsion occupies the second place, while the plant residuals occupies the third place and has slight effects on the studied parameters. Effects of conditioners on natural vegetation cover are negative in oil derivatives treatments,while positive in plants residuals treatments.

  5. Thermoluminescent dosimetric properties of Descalvado sand

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, M.I.; Caldas, L.V.E

    2006-07-01

    Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ({sup 60} Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

  6. Development tendencies of moulding and core sands

    Directory of Open Access Journals (Sweden)

    Stanislaw M. Dobosz1

    2011-11-01

    Full Text Available Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.

  7. Planet-wide sand motion on mars

    Science.gov (United States)

    Bridges, N.T.; Bourke, M.C.; Geissler, P.E.; Banks, M.E.; Colon, C.; Diniega, S.; Golombek, M.P.; Hansen, C.J.; Mattson, S.; McEwen, A.S.; Mellon, M.T.; Stantzos, N.; Thomson, B.J.

    2012-01-01

    Prior to Mars Reconnaissance Orbiter data, images of Mars showed no direct evidence for dune and ripple motion. This was consistent with climate models and lander measurements indicating that winds of sufficient intensity to mobilize sand were rare in the low-density atmosphere. We show that many sand ripples and dunes across Mars exhibit movement of as much as a few meters per year, demonstrating that Martian sand migrates under current conditions in diverse areas of the planet. Most motion is probably driven by wind gusts that are not resolved in global circulation models. A past climate with a thicker atmosphere is only required to move large ripples that contain coarse grains. ?? 2012 Geological Society of America.

  8. Prevalence and multidrug-resistant pattern of Salmonella from the eggs and egg-storing trays of retail markets of Bangladesh

    Directory of Open Access Journals (Sweden)

    Tareq Mahmud

    2016-03-01

    Full Text Available Aim: Salmonellosis is one of the most common and widely distributed foodborne illnesses in human, and multidrugresistance of Salmonella spp. has increased in developing countries with the indiscriminate use of antibiotics in the poultry production system. A cross-sectional study was conducted on randomly selected retail markets of Chittagong City Corporation to determine the prevalence and antimicrobial resistance pattern of Salmonella isolated from commercial layer eggs, eggshell surface, and egg-storing trays. Materials and Methods: Chicken eggs, egg surface, and egg-storing trays samples from the retail markets were collected for isolating Salmonella spp. (bacteriological culture methods followed by antimicrobial susceptibility testing (disc diffusion method against Salmonella isolates during the period from July to December 2013. Results: Out of the 310 layer eggs, egg surface, and egg-storing trays samples, the highest prevalence of Salmonella spp. was found in eggs trays (57.15% and the lowest (13.33% in eggs and the prevalence differed significantly (p0.05. Isolated Salmonella was tested for resistance to eight different antimicrobial agents, using disc diffusion method. Among eight antimicrobial tested (n=111, 100% resistance were found to ampicillin and amoxicillin followed by erythromycin (60-100%, tetracycline (72-93%, ciprofloxacin (22-66%, colistin (27-66%, enrofloxacin (42-54%, and pefloxacin 23.07% across the study sites. Ciprofloxacin remained sensitive in 40.9% cases and, pefloxacin and colistin appeared to be almost sensitive (61-72% against Salmonella isolates at studied areas. Salmonella isolates showed multidrug-resistance pattern up to five of the eight antimicrobials tested. Conclusion: It can be said that the rational use of antibiotics needs to be adopted in commercial poultry farming system of Bangladesh to prevent the emergence of drug-resistance Salmonella to protect the public health consequences.

  9. An evaluation of methodology for seismic qualification of equipment, cable trays, and ducts in ALWR plants by use of experience data

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, K.K.; Kana, D.D.; Kennedy, R.P.; Schiff, A.J.

    1997-07-01

    Advanced Reactor Corporation (ARC) has developed a methodology for seismic qualification of equipment, cable trays and ducts in Advanced Light Water Reactor plants. A Panel (members of which acted as individuals) supported by the Office of Nuclear Regulatory Research of the Nuclear Regulatory Commission has evaluated this methodology. The review approach and observations are included in this report. In general, the Panel supports the ARC methodology with some exceptions and provides recommendations for further improvements. 26 refs., 10 figs., 1 tab.

  10. Undrained Cyclic Behaviour of Dense Frederikshavn Sand

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Ibsen, Lars Bo; Sørensen, Kris Wessel

    2013-01-01

    A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series of undra......A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series...

  11. Sand control systems used in completing wells

    Directory of Open Access Journals (Sweden)

    Gabriel Wittenberger

    2005-12-01

    Full Text Available Expandable Tubular Technology is transforming the face of well completion and construction. This technology provides: a substantially higher hydrocarbon production rates from the reservoir, a reduced well drilling and construction costs, new possibilities for previously unreachable or uneconomic reservoirs, and step a change towards the single diameter well. ESS (Expandable Sand Screen has an unrivalled performance worldwide for delivering a reliable sand control in a wide range of applications. Well costs typically cut by over 20 %, and the productivity increases up to 70 %.

  12. On the Size Distribution of Sand

    DEFF Research Database (Denmark)

    Sørensen, Michael

    2016-01-01

    -distribution, by taking into account that individual grains do not have the same travel time from the source to the deposit. The travel time is assumed to be random so that the wear on the individual grains vary randomly. The model provides an interpretation of the parameters of the NIG-distribution, and relates the mean......A model is presented of the development of the size distribution of sand while it is transported from a source to a deposit. The model provides a possible explanation of the log-hyperbolic shape that is frequently found in unimodal grain size distributions in natural sand deposits, as pointed out...

  13. George Sand [Reseña

    OpenAIRE

    Jack, Belinda; Thomas, Florence

    2002-01-01

    Belinda Jack nos cuenta en ese libro la vida de George Sand (de su verdadero nombre Aurora Dupin), esa mujer libertaria del siglo XIX, lo años de su nacimiento, su infancia, su adolescencia y su vida adulta. Una vida tan llena tanto por sus luchas interiores -Sand es una mujer que desde su adolescencia tratará de romper los fatalismos ligados a la condición de mujer del siglo XIX, un siglo profundamente familista y maternalista- como por su inmensa obra literaria que cuenta más de cincuenta n...

  14. Investigation of Sand-Cement Grouts

    Science.gov (United States)

    1960-09-01

    the sianAS. Ho-4, VVers thia 𔃽pacification ,Jlowi -inI r.ver,4 e ofl 3 :*- cen~t to be retain(v,- on1 the NO,. 1E6 sieve. 3y * :.Oviiq- (1),, sc...325 material as does the traprock or silica sand. This j J: i3 -robably the reason for the difference in the quantity of sand founud pmrnable. The three...deficient in material assing th.e ±,e h DOsieve, Ath the addition of percentages of fŕ. ash was test-ilwped. in the other to-ts in this phase, tne

  15. TURBULENT COHERENT STRUCTURES IN CHANNELS WITH SAND WAVES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Sand wave bed is one of the typical shape of complicated boundaries in hydraulics and river dynamics, and sand wave motion is the main form of the bed load motion in-rivers, thence the study of turbulent structures over sand waves is of importance both in theory and practice. In this paper turbulent coherent structures over single-and multi-sand waves were studied experimentally, the formulae for the separation length and vortex shedding period of the turbulent flow over single-sand wave were suggested, and the characteristics of turbulent coherent structures over multi-sand waves were also given.

  16. Threshold for sand mobility on Mars calibrated from seasonal variations of sand flux

    Science.gov (United States)

    Ayoub, F.; Avouac, J.-P.; Newman, C. E.; Richardson, M. I.; Lucas, A.; Leprince, S.; Bridges, N. T.

    2014-09-01

    Coupling between surface winds and saltation is a fundamental factor governing geological activity and climate on Mars. Saltation of sand is crucial for both erosion of the surface and dust lifting into the atmosphere. Wind tunnel experiments along with measurements from surface meteorology stations and modelling of wind speeds suggest that winds should only rarely move sand on Mars. However, evidence for currently active dune migration has recently accumulated. Crucially, the frequency of sand-moving events and the implied threshold wind stresses for saltation have remained unknown. Here we present detailed measurements of Nili Patera dune field based on High Resolution Imaging Science Experiment images, demonstrating that sand motion occurs daily throughout much of the year and that the resulting sand flux is strongly seasonal. Analysis of the seasonal sand flux variation suggests an effective threshold for sand motion for application to large-scale model wind fields (1-100 km scale) of τs=0.01±0.0015 N m-2.

  17. An applicable method for efficiency estimation of operating tray distillation columns and its comparison with the methods utilized in HYSYS and Aspen Plus

    Science.gov (United States)

    Sadeghifar, Hamidreza

    2015-10-01

    Developing general methods that rely on column data for the efficiency estimation of operating (existing) distillation columns has been overlooked in the literature. Most of the available methods are based on empirical mass transfer and hydraulic relations correlated to laboratory data. Therefore, these methods may not be sufficiently accurate when applied to industrial columns. In this paper, an applicable and accurate method was developed for the efficiency estimation of distillation columns filled with trays. This method can calculate efficiency as well as mass and heat transfer coefficients without using any empirical mass transfer or hydraulic correlations and without the need to estimate operational or hydraulic parameters of the column. E.g., the method does not need to estimate tray interfacial area, which can be its most important advantage over all the available methods. The method can be used for the efficiency prediction of any trays in distillation columns. For the efficiency calculation, the method employs the column data and uses the true rates of the mass and heat transfers occurring inside the operating column. It is highly emphasized that estimating efficiency of an operating column has to be distinguished from that of a column being designed.

  18. Migration of antimony from PET trays into food simulant and food: determination of Arrhenius parameters and comparison of predicted and measured migration data.

    Science.gov (United States)

    Haldimann, M; Alt, A; Blanc, A; Brunner, K; Sager, F; Dudler, V

    2013-01-01

    Migration experiments with small sheets cut out from ovenable PET trays were performed in two-sided contact with 3% acetic acid as food simulant at various temperatures. The fraction of diffusible antimony (Sb) was estimated to be 62% in the PET sample under study. Apparent diffusion coefficients of Sb in PET trays were determined experimentally. Measurement of migration between 20 and 150°C yielded a linear Arrhenius plot over a wide temperature range from which the activation energy (E(a)) of 188 ± 36 kJ mol(-1) and the pre-exponential factor (D(0)) of 3.6 × 10(14) cm(2) s(-1) were determined for diffusing Sb species. E (a) was similar to previously reported values for PET bottles obtained with a different experimental approach. E (a) and D (0) were applied as model parameters in migration modelling software for predicting the Sb transfer in real food. Ready meals intended for preparation in a baking oven were heated in the PET trays under study and the actual Sb migration into the food phase was measured by isotope dilution ICP-MS. It was shown that the predictive modelling reproduces correctly experimental data.

  19. MouldingSandDB – a modern database storing moulding sands properties research results

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

  20. Real-Time Simulation of Aeolian Sand Movement and Sand Ripple Evolution: A Method Based on the Physics of Blown Sand

    Institute of Scientific and Technical Information of China (English)

    Ning Wang; Bao-Gang Hu

    2012-01-01

    Simulation and visualization of aeolian sand movement and sand ripple evolution are a challenging subject.In this paper,we propose a physically based modeling and simulating method that can be used to synthesize sandy terrain in various patterns.Our method is based on the mechanical behavior of individual sand grains,which are widely studied in the physics of blown sand.We accounted significant mechanisms of sand transportation into the sand model,such as saltation,successive saltation and collapsing,while simplified the vegetation model and wind field model to make the simulation feasible and affordable.We implemented the proposed method on the programming graphics processing unit (GPU) to get real-time simulation and rendering.Finally,we proved that our method can reflect many characteristics of sand ripple evolution through several demonstrations.We also gave several synthesized desert scenes made from the simulated height field to display its significance on application.

  1. Characterization and drying of caja bagasse (Spondias mombin L. in a tray dryer using a factorial planning

    Directory of Open Access Journals (Sweden)

    Andréia Souto da Silva

    2012-03-01

    Full Text Available The caja (Spondias mombin L. is used in the manufacture of ice-cream, jams, pulps, beverages being also consumed in natura. One of the most important procedures in food conservation is drying, considering that most fresh fruits contain approximately 80% of water. Food drying is used to obtain two basic aspects: (1 the economic factor; in the shipping and handling of the product; (2 at the manipulation; once dried and grinded, the material is rehydrated, at desirable levels, to formulate a new product as in ice cream, jams, yoghurts and drinks and may also be added to pasta, biscuits and other industrialized products. The aim of this study was to investigate the kinetics of caja bagasse drying in a fixed-bed tray dryer, using central composite factorial planning. The following factors were evaluated: temperature (55, 65 and 75 ºC, dryer inlet air velocity (3.2, 4.6 and 6.0 m.s-1 and cake thickness (0.8, 1.2 and 1.6 cm where the response of the considered variable was caja bagasse moisture content (b.s. and the results showed that the main effects and their interactions were significant at a 95% confidence level being the best condition obtained at temperature of 75 ºC, velocity of 6.0 m.s-1 and cake thickness of 0.8 cm.

  2. [What is hidden behind the Baking Tray Task? Study of sensibility and specificity in right-hemispheric stroke patients].

    Science.gov (United States)

    Garcia-Fernandez, Juan; Garcia-Molina, Alberto; Aparicio-Lopez, Celeste; Sanchez-Carrion, Rocío; Ensenat, Antònia; Pena-Casanova, Jordi; Roig-Rovira, Teresa

    2015-12-16

    Introduccion. Tham y Tegner propusieron el Baking Tray Task (BTT) como una prueba de evaluacion rapida y simple para la deteccion de negligencia espacial. No obstante, apenas existen estudios que hayan examinado su validez como prueba diagnostica. Objetivo. Analizar la validez diagnostica del BTT, midiendo su especificidad y sensibilidad, en una muestra de sujetos con ictus hemisfericos derechos. Sujetos y metodos. Cuarenta y ocho pacientes con lesiones vasculares hemisfericas derechas distribuidos en dos grupos (grupo negligencia, n = 35; grupo no negligencia, n = 13) en funcion de las puntuaciones obtenidas en una bateria de exploracion visuoespacial. La ejecucion de los participantes en el BTT se comparo con un grupo control sano (n = 12). Resultados. Los resultados mostraron una alta sensibilidad del BTT, pero una baja especificidad. Ocho de los 13 integrantes del grupo no negligencia obtuvieron un rendimiento en el BTT sugestivo de negligencia. Conclusiones. El BTT se muestra como un test sensible para la deteccion de la negligencia espacial. Sin embargo, basandonos en su baja especificidad, no es recomendable su uso aislado como prueba unica de diagnostico.

  3. Model and simulation of a vacuum sieve tray for T extraction from liquid PbLi breeding blankets

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, M.A.J., E-mail: merlijn.mertens@ugent.be [Ghent University, Department of Materials Science and Engineering, Center of Molecular Modeling, Technologiepark 903, B-9052 Zwijnaarde (Belgium); Demange, D., E-mail: david.demange@kit.edu [Karlsruhe Institute of Technology, Institute for Technical Physics, Tritium Laboratory Karlsruhe, Hermann-von-Helmholtz Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Frances, L., E-mail: laetitia.frances@kit.edu [Karlsruhe Institute of Technology, Institute for Technical Physics, Tritium Laboratory Karlsruhe, Hermann-von-Helmholtz Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2016-11-15

    Highlights: • A simulation tool was developed to analyse, optimise and scale up VST set-ups. • This tool predicts that efficiencies higher than 90% can be reached. • Upscaling to DEMO breeding blanket flow rates results in feasibly sized designs. - Abstract: Tritium self-sufficiency within a nuclear fusion reactor is necessary to demonstrate nuclear fusion as a viable source of energy. Tritium can be produced within liquid eutectic PbLi but then has to be extracted to be refuelled to the plasma. The vacuum sieve tray (VST) method is based on the extraction of tritium from millimetre-scaled oscillating PbLi droplets falling inside a vacuum chamber. A simulation tool was developed describing the fluid dynamics occurring along the PbLi flow and was used to study the influence of the different geometrical and operational parameters on the VST performance. The simulation predicts that extraction efficiencies over 90% can be easily reached according to theory and previous experimental results. The size of the VST extraction unit for a fusion reactor is estimated based on the findings from our single-nozzle model and assuming no T reabsorption. It is found to be in the feasible range. Nevertheless, two approaches are discussed which may further reduce this size by up to 90%. The simulation tool proved to be an easy and powerful way to analyse and optimise VST set-ups at any scale.

  4. Fabrication of a Sectional Impression Tray and a Collapsible Removable Complete Denture in a Microstomia Patient: A Clinical Report

    Directory of Open Access Journals (Sweden)

    Ahmadzadeh A.

    2011-05-01

    Full Text Available An abnormally small oral orifice is defined as microstomia which is caused by various factors like burning, scleroderma, etc. This disorder is difficult to treat due to the reduced oral opening. In particular, fabrication of removable prostheses is further complicated by tongue rigidity and the constant adjustment required to accommodate the changing periphery; however, successful treatment is possible through specific measures. In this article, a 41-year-old woman living in Baghmalek, Khoozestan was referred to the Prosthodontic department of Jondishapoor University in Ahvaz, southern Iran. She was suffering from microstomia and poor manual ability caused by scleroderma. Initial impression was prepared for her, using Silicon impression material by applying fingers pressure. The final impression was prepared using a two section tray so that the larger part covered one third of the smaller one and both could be attached by compressable button. Then the occlusal relation was established using occlusal rims connected to the two section parcels. Two part parcel prostheses connected with attachments were made for the lower and upper jaws, respectively. The patient was followed up for six months. Conclusion: In order to overcome the above-mentioned problems, the new method of removable prosthesis enjoys the advantage of sufficient precision as well as ease of use by the patient. For further evaluation, diagnosis and proper treatment plan are reported.

  5. Effect of reactive adhesives on the tensile bond strength of polyvinyl siloxane impression materials to methyl methacrylate tray material.

    Science.gov (United States)

    Ona, Masahiro; Takahashi, Hidekazu; Sato, Masayuki; Igarashi, Yoshimasa; Wakabayashi, Noriyuki

    2010-05-01

    The effect of new adhesives on the bond strength of elastomeric impression materials to acrylic trays was evaluated. Two polyvinyl siloxane impression materials (Fusion and Imprinsis) with reactive adhesives and one (Examix) with a conventional adhesive were tested. Flat, double-sided plates of auto-polymerizing methyl methacrylate (10 x 10 x 2.5 mm) were prepared with one of the adhesives. Five specimens were prepared by injecting each impression material into a 2-mm gap between the two plates. Tensile tests were conducted until separation failure occurred. The mean bond strengths of Fusion (1.0 MPa) and Imprinsis (0.8 MPa) were significantly greater than that of Examix (0.2 MPa). On the contrary, one of five Fusion showed adhesive failure mode while all the Imprinsis exhibited mixed failure. The conflicting results were presumably attributed to the mean tear strength of Fusion (0.8 N/mm) being higher than that of Imprinsis (0.5 N/mm).

  6. Simulation of aeolian sand saltation with rotational motion

    Science.gov (United States)

    Huang, Ning; Wang, Cong; Pan, Xiying

    2010-11-01

    In this work, we propose a theoretical model based on the distribution functions of initial liftoff velocity and angular velocity of sand grains to describe a sand saltation process in which both wind field-sand grain coupling and the Magnus force experienced by saltating sand grains have been incorporated. The computation results showed that the Magnus force had significant effects on sand grain saltation. In particular, when the Magnus force was incorporated, the calculated sand transport fluxes and sand transport rate per unit width were closer to the experimental value than when this force was excluded. The sand transport flux is enhanced because the Magnus force owing to particle rotation causes the particles to have higher and longer trajectories, so the particles can get more speed and energy from the wind, which leads to a larger sand transport flux. In addition, it was found that when taking the Magnus force into account, the probability density of the impact velocity and angular velocity of saltating sand grains followed an exponential distribution and a unimodal asymmetric distribution, respectively. Moreover, the sand energy flux increased with the height above the sand surface until the energy flux reached its maximum and then decreased. Furthermore, the energy flux near the ground surface decreased as the grain diameter increased, but beyond a specific height the energy flux increased with the grain diameter. Finally, for the same sand grain diameter, the energy flux increased with the friction velocity.

  7. Influence of modified tray on mandible complete denture impression%改良型托盘对下颌全口义齿印模的影响

    Institute of Scientific and Technical Information of China (English)

    崔荣智; 潘新华

    2012-01-01

    Objective:To observe the influence of modified tray and conventional tray on mandible complete denture and the clinical effect after dental restoration. Method: 60 cases that were edentulous in mandible or with inferior alveolar ridge were treated with two methods of mandible complet denture impression five items were evaluated after wearing den- ference in the two groups in the aspects of comfort and masticatory function, mucosa and food impact ion, with P >0.05; while in the aspects of retaining function,the group with modified tray was superior to the group with conventional tray, with P < 0.05. Conclusion: Impression with modified tray obviously increased the absorption force of mandible complete denture, and may be applicable generally to the patients with inferior alveolar ridge%目的:观察改良型托盘与传统托盘对下颌全口义齿印模的影响,比较义齿修复后的临床效果.方法:对60例无牙颌牙槽嵴条件较差病例进行两种印模方法制取下颌全口义齿印模,义齿戴入后对义齿的固位功能、黏膜情况,舒适性、咀嚼功能、食物嵌塞5项内容进行评价.结果:两组病例在舒适程度、黏膜情况、食物嵌塞、咀嚼功能等方面无显著性差异,P >0.05;但在固位功能方面改良型托盘组明显优于传统托盘组,P <0.05.结论:改良型托盘制取的印模显著提高了下颌全口义齿的吸附力,可以普遍应用于牙槽嵴或黏膜条件差的无牙颌修复患者.

  8. In-service testing of Ni{sub 3}Al coupons and trays in carburizing furnaces at Delphi Saginaw. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Santella, M.L.; Viswanathan, S.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Chatterjee, M. [General Motors Corporaion, Saginaw Division (United States)

    1998-08-01

    This Cooperative Research and Development Agreement (CRADA) report deals with the development of nickel aluminide alloy for improved longer life heat-resistant fixture assemblies for batch and continuous pusher carburizing furnaces. The nickel aluminide development was compared in both coupon and component testing with the currently used Fe-Ni-Cr heat-resisting alloy known as HU. The specific goals of the CRADA were: (1) casting process development, (2) characterization and possible modification of the alloy composition to optimize its manufacturing ability and performance under typical furnace operating conditions, and (3) testing and evaluation of specimens and prototype fixtures. In support of the CRADA objectives, coupons of nickel aluminide and the HU alloy were installed in both batch and pusher furnaces. The coupons were taken from two silicon levels and contained welds made with two different filler compositions (IC-221LA and IC-221W). Both nickel-aluminide and HU coupons were removed from the batch and pusher carburizing furnace at time intervals ranging from one month to one year. The exposed coupons were cut and mounted for metallographic, hardness, and microprobe analysis. The results of the microstructural analysis have been transmitted to General Motors Corporation, Saginaw Division (Delphi Saginaw) through reports that were presented at periodic CRADA review meetings. Based on coupon testing and verification of the coupon results with the testing of trays, Delphi Saginaw moved forward with the use of six additional trays in a batch furnace and two assemblies in a pusher furnace. Fifty percent of the trays and fixtures are in the as-cast condition and the remaining trays and fixtures are in the preoxidized condition. The successful operating experience of two assemblies in the pusher furnace for nearly a year formed the basis for a production run of 63 more assemblies. The production run required melting of 94 heats weighing 500 lb. each. Twenty

  9. WFGD Sieve Tray Spray Scrubber%湿法烟气脱硫筛板式喷淋塔阻力特性的试验研究

    Institute of Scientific and Technical Information of China (English)

    王惠挺; 钟毅; 高翔; 陈湘文; 骆仲泱; 倪明江; 岑可法

    2009-01-01

    Experimental study on pressure drop characteristics in a wet flue gas desulfurization (WFGD) sieve tray spray scrubber was carried out by taking water and air as the medium, during which factors influencing the pressure drop characteristics were discussed, such as the diameter and percentage of the openings, the thickness and location of the tray and the liquid spray rate etc. Results show that the diameter ratio of the opening to the scrubber in the WFGD sieve tray spray scrubber system should be big enough so that it can satisfy the high-speed flue gas requirements. Under low flue gas velocity conditions, the smaller the openings' diameter, the higher the pressure drop will be, and under high flue gas velocity conditions, the variation is just the opposite. Thickness of the tray has little influence on the pressure drop, and the pressure drop can be effectively reduced by raising the percentage of openings, lifting up the location of the tray and lowering the spray rates.%采用水-空气作为介质对湿法烟气脱硫(WFGD)筛板式喷淋塔阻力特性进行了试验研究,分析了筛板孔径、开孔率、厚度、安装位置以及液相喷淋量等因素对筛板喷淋塔内阻力特性的影响.结果表明:在WFGD系统筛板式喷淋塔中必须保证足够大的孔径与塔径比,以适合高速烟气条件;在烟气流速较低条件下,筛板孔径越小,压降越大,而烟气流速较高时则相反;筛板厚度对于压降影响较小;提高开孔率和筛板安装高度以及减少喷淋量均能降低塔内阻力.

  10. The impact of raindrops on sand

    NARCIS (Netherlands)

    de Jong, Rianne

    2017-01-01

    When a raindrop hits a sand bed, it leaves behind a small crater with a mixture of liquid and grains located at the center. This event is frequently observed in nature, but when absent, sprinklers may artificially produce these impacting drops to facilitate irrigation. Also in industry, the interact

  11. Cumulative environmental management and the oil sands

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    In response to concerns regarding the cumulative environmental impacts of oil sands development within the Athabasca oil sands deposit, the government of Alberta established a Regional Sustainable Development Strategy (RSDS) to balance development with environmental protection. The environmental issues identified through the RSDS were addressed by the Cumulative Environmental Management Association (CEMA). CEMA's boundary is the Wood Buffalo region of northeastern Alberta. It identifies existing and future environmental effects in the region and proposes recommendations to regulatory bodies for reducing environmental impacts associated with oil sands development. This presentation outlined some of the 55 stakeholder representatives of CEMA, including Alberta government departments associated with resource development, oil sand developers within the region, and Aboriginal communities and First Nations. These stakeholders provide input on sector priorities and agree on environmental thresholds. Established working groups also address technical and scientific research issues identified in the RSDS such as sustainable ecosystems; surface waters; trace metals and air contaminants; nitrogen oxides and sulphur dioxides; and land reclamation. To date, CEMA has submitted more than 50 reports and has made 4 major environmental recommendations for trace metal management, ecosystem management tools, a framework for acid deposition management, and a landscape design checklist. tabs., figs.

  12. LEARNING ABOUT THE OCEANS FROM SAND

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    As a young geophysicist in the 1980s, Rob Holman attended a conference in San Francisco that included a field trip to a beach. Dr Holman, who grew up inland, stared at the ocean, assessing the strengths of the waves. But when he looked around, everyone else was studying the sand.

  13. Displacement pile installation effects in sand

    NARCIS (Netherlands)

    Beijer-Lundberg, A.

    2015-01-01

    Installation effects govern the post-installation behaviour of displacement piles in sand. These effects are currently not completely understood. Suitable experimental techniques to model these installation effects include field, laboratory and experimental models. In the current thesis a small-scal

  14. Cyclic Triaxial Loading of Cohesionless Silty Sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2015-01-01

    To engineer efficient structures offshore, we need to extend our knowledge of soil response. Cyclic loading and high water pressure encountered offshore greatly influence cohesionless soil performance. Silty sand from Frederikshavn wind turbine farm was tested using single diameter height samples...

  15. Galveston Island, Texas, Sand Management Strategies

    Science.gov (United States)

    2016-07-01

    68 Figure 28. Jetty segment used for computation of aeolian sand transport. Background photograph 22 May 2012...113 Figure 68 . Total shoreline change after 50 years for 500,000 yd3 placed every 2 years in different locations...The berm at Ft. Myers, FL, was constructed with dredged material from Matanzas Pass. The dredged material contained greater than 10% fines, which

  16. Building Whales in Sand and Mind.

    Science.gov (United States)

    Warner, Carolyn

    1980-01-01

    Describes two-week summer workshops on evolution, adaptation, and behavior of whales, conducted for children by Cold Spring Harbor Whaling Museum (New York), and culminating in creation of life-size sand sculptures of whales. Provides selected list of periodicals, teaching materials, identification guides, records, and societies devoted to whales…

  17. Sand transport, erosion and granular electrification

    DEFF Research Database (Denmark)

    Merrison, J.P.

    2012-01-01

    The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate and impac......The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate...... can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel...... erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work...

  18. Sand Waves along the Dutch Coast

    NARCIS (Netherlands)

    Verhagen, H.J.

    1989-01-01

    Sand waves, defined as longshore wave-like movements of the shoreline, measured in a horizontal plane, are described along several stretches of the shoreline of The Netherlands. They have a celerity in the order of 50-200 m/yr, a period of 50- 150 years and an amplitude of 30- 500 m. They are found

  19. Building Whales in Sand and Mind.

    Science.gov (United States)

    Warner, Carolyn

    1980-01-01

    Describes two-week summer workshops on evolution, adaptation, and behavior of whales, conducted for children by Cold Spring Harbor Whaling Museum (New York), and culminating in creation of life-size sand sculptures of whales. Provides selected list of periodicals, teaching materials, identification guides, records, and societies devoted to whales…

  20. Sand and Stone%沙与石

    Institute of Scientific and Technical Information of China (English)

    黄川; 孙静

    2006-01-01

    @@ Astory tells that two friends were walking through the desert. During some point of the journey they had an argument, and one friend slapped the other one in the face1. The one who got slapped was hurt, but without saying anything, he wrote in the sand: "TODAY MY BEST FRIEND SLAPPED ME IN THE FACE."

  1. Dark grains of sand: a geological storytelling

    Science.gov (United States)

    Gallo Maresca, Magda

    2017-04-01

    In the secondary Italian school the Earth science learning begins at first year, in synergy with other natural science subjects such as Astronomy, Chemistry and Biology. Italian teachers have to focus on the landscape geomorphological aspects and often Earth processes are difficult to display since they are related to certain phenomena happened during the past and often far from the involved country. In order to better understand the environment surrounding us, very simple and poor materials, like sands, allow the teachers to create attractive lab experiences. According to the IBSE (Inquiry Based Science Education) approach, a learning unit has been implemented starting from a walking along the light carbonate beaches of the Adriatic sea: a smart look to the sands ("engage step"), stroke the students fantasy pushing them to explore some strange black grains on the sands. Dirty sands? Or rock landscape, soil degradation and Ofanto river and coastal processes (erosion, transportation and deposition)? This was the teaching challenge. Due to the youngest age, a third level, guided inquiry, was adopted so the teacher is the "guide of inquiry" encouraging the students using the research question ("Why is the sand dark?", "Do all sands look the same?", "Where does it come from?") and driving the students around their investigation plans ("How can I measure grain size?"). A procedure to answer the above questions and validate the results and explanations has been implemented to allow the students to be proactive in their study. During the learning activities will be the students to ask for field trip to elaborate their new knowledge, verify and visualize the speculated processes. The teaching skills allow to address several geosciences domains such as mineralogy, petrology, regional geology and geodynamics as well as other scientific disciplines such as mathematics (more specifically statistics), forensic science and even life sciences (the presence of bioclasts might

  2. Assessing environmental impacts of inland sand mining in parts of ...

    African Journals Online (AJOL)

    Assessing environmental impacts of inland sand mining in parts of Ogun State, Nigeria. ... Sand is a valuable resource for construction and other purposes, however ... Natural resources particularly, land, water quality and quantity, air quality, ...

  3. Fiber-reinforced sand strength and dilation characteristics

    Directory of Open Access Journals (Sweden)

    Hesham M. Eldesouky

    2016-06-01

    Full Text Available Randomly distributed fiber reinforcement is used to provide an isotropic increase in the sand shear strength. The previous studies were not consistent regarding the fibers effect on the volumetric change behavior of fiber-reinforced sand. In this paper, direct shear tests are conducted on 108 specimens to investigate the effects of the fibers content, relative density, normal stress and moisture content on the shear strength and volumetric change behaviors of fiber-reinforced sand. The study investigates also the possibility of using dry fiber-reinforced sand as an alternative to heavily compacted unreinforced moist sand. The results indicate that the fibers inclusion increases the shear strength and dilation of sand. Moisture suppresses the fibers effect on the peak and post-peak shear strengths, and dilation. Dry loose fiber-reinforced sand achieves the same shear strength of heavily compacted unreinforced moist sand, yet at more than double the horizontal displacement.

  4. Gating Technology for Vertically Parted Green Sand Moulds

    DEFF Research Database (Denmark)

    Larsen, Per

    Gating technology for vertically parted green sand moulds. Literature study of different ways of designing gating systems.......Gating technology for vertically parted green sand moulds. Literature study of different ways of designing gating systems....

  5. Expandable sand screens: from novel concept to proven sand control technique

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, Paul; Jones, Colin; Ballard, Tracey; Beare, Steve; Hillis, Dave [Weatherford International Inc., Houston, TX (United States)

    2004-07-01

    Expandable Sand Screens (ESS) have proved a viable alternative to gravel packing for sand control. With over 300 installations worldwide, analysis of their use has confirmed that ESS offers excellent production performance and sand control reliability in Open hole. This paper presents details of a global survey on ESS performance that gives accurate information on production performance, sand exclusion reliability and cost effectiveness in Open hole and cased hole application scenarios. This paper also discusses the role and effect of compliant expansion in observed productivity performance and skin values. The rock mechanical, reservoir characterization and metallurgical requirements of ESS systems are also investigated. Finally, the latest advances of the technology for use within the reservoir are explained. This paper demonstrates how the combination of ESS and Expandable Zonal Isolation devices can offer cased hole functionality (in terms of zonal isolation) in combination with Open hole levels of production performance (from the ESS). (author)

  6. Water management in the oil sands industry

    Energy Technology Data Exchange (ETDEWEB)

    Pauls, R. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2004-07-01

    Water management issues at Alberta's 4 oil sand deposits were discussed. The 4 deposits include the Peace River, Athabasca, Wabasca and Cold Lake deposits, with the Athabasca deposit being the largest and the only surface-mineable deposit. Large quantities of water are needed to extract bitumen from oil sands. This paper addressed water volume withdrawal from the Athabasca River, the primary source of water for the surface-mining oil sands industry. It also addressed Muskeg River watershed integrity, quality of water withdrawn from reclaimed landscapes, groundwater contamination, and ecological viability of end-pit lakes. Currently, half of Syncrude's oil sand is transported from mine to extraction plant by conveyor belts. The other half is pipelined as a warm water slurry. By 2005, all transport will be by pipeline. The oil sand is mixed with hot water, steam and surfactants to condition it for extraction. Seventy-nine per cent of the water used by Syncrude is recycled water and the remainder comes from the Athabasca River. Syncrude diverts 2.5 to 3 barrels of water from the Athabasca River for every barrel of oil produced. This paper discussed the in-stream flow needs of the Athabasca River based on protection of aquatic ecosystems. Flow needs are addressed by the Cumulative Effects Management Association (CEMA). The paper states that the proportion of annual flow withdrawn from the Athabasca River is too low to have a significant impact on aquatic systems, but the main concern lies in water use during low flow periods, typically during the winter months. Developers will likely come under pressure to develop off-site reservoirs to store water for use during these low-flow periods. tabs., figs.

  7. Imaging of Acoustic Waves in Sand

    Energy Technology Data Exchange (ETDEWEB)

    Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

    2003-08-01

    There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image of acoustic waves in sand or soil, and their interaction with buried objects. The INEEL Laser Ultrasonic Camera utilizes dynamic holography within photorefractive recording materials. This permits one to image and demodulate acoustic waves on surfaces in real time, without scanning. A video image is produced where intensity is directly and linearly proportional to surface motion. Both specular and diffusely reflecting surfaces can be accomodated and surface motion as small as 0.1 nm can be quantitatively detected. This system was used to directly image acoustic surface waves in sand as well as in solid objects. Waves as frequencies of 16 kHz were generated using modified acoustic speakers. These waves were directed through sand toward partially buried objects. The sand container was not on a vibration isolation table, but sat on the lab floor. Interaction of wavefronts with buried objects showed reflection, diffraction and interference effects that could provide clues to location and characteristics of buried objects. Although results are preliminary, success in this effort suggests that this method could be applied to detection of buried landmines or other near-surface items such as pipes and tanks.

  8. Incipient Motion of Sand and Oil Agglomerates

    Science.gov (United States)

    Nelson, T. R.; Dalyander, S.; Jenkins, R. L., III; Penko, A.; Long, J.; Frank, D. P.; Braithwaite, E. F., III; Calantoni, J.

    2016-12-01

    Weathered oil mixed with sediment in the surf zone in the northern Gulf of Mexico after the 2010 Deepwater Horizon oil spill, forming large mats of sand and oil. Wave action fragmented the mats into sand and oil agglomerates (SOAs) with diameters of about 1 to 10 cm. These SOAs were transported by waves and currents along the Gulf Coast, and have been observed on beaches for years following the spill. SOAs are composed of 70%-95% sand by mass, with an approximate density of 2107 kg/m³. To measure the incipient motion of SOAs, experiments using artificial SOAs were conducted in the Small-Oscillatory Flow Tunnel at the U.S. Naval Research Laboratory under a range of hydrodynamic forcing. Spherical and ellipsoidal SOAs ranging in size from 0.5 to 10 cm were deployed on a fixed flat bed, a fixed rippled bed, and a movable sand bed. In the case of the movable sand bed, SOAs were placed both proud and partially buried. Motion was tracked with high-definition video and with inertial measurement units embedded in some of the SOAs. Shear stress and horizontal pressure gradients, estimated from velocity measurements made with a Nortek Vectrino Profiler, were compared with observed mobility to assess formulations for incipient motion. For SOAs smaller than 1 cm in diameter, incipient motion of spherical and ellipsoidal SOAs was consistent with predicted critical stress values. The measured shear stress at incipient motion of larger, spherical SOAs was lower than predicted, indicating an increased dependence on the horizontal pressure gradient. In contrast, the measured shear stress required to move ellipsoidal SOAs was higher than predicted, even compared to values modified for larger particles in mixed-grain riverine environments. The laboratory observations will be used to improve the prediction of incipient motion, transport, and seafloor interaction of SOAs.

  9. Optical and radiocarbon ages of stacked paleosols and dune sands in the Nebraska Sand Hills, USA

    Science.gov (United States)

    Goble, R. J.; Mason, Joseph A.; Loope, David B.; Swinehart, James B.

    2004-05-01

    Optical ages for eolian sands from the Nebraska Sand Hills indicate periods of extensive eolian activity at ca 115±25, 840±70, 2300±240, and 3560±340 a. Activity was also noted at single sampling locations at ca 6180±370, 8430±510 and 13110±800 a. Many of these ages are similar to those noted by earlier authors. Optical ages from samples collected within paleosols indicate shorter and possibly less extensive periods of eolian activity at approximately 1220±150, 1590±110, and possibly 1950±150 a, during which the paleosol sands accumulated. What was originally interpreted as a single 1.2 m thick paleosol is shown by optical dating to consist of three or more welded soils developed within eolian sands with optical ages of ca 3800±240, 2740±240, 1560±110, and possibly 1930±140 a, each of which match eolian pulses recognized elsewhere. Scatter in some optical ages is attributable to intersection of sand-filled rodent burrows extending in outcrop 1.5 m below the contact between paleosol and overlying topset beds. A 5310±360 a optical age for one probable intersected burrow provides evidence for upward or lateral transport of older sands.

  10. Evaluate of head loss, sediment value and copper removal in sand media (rapid sand filter

    Directory of Open Access Journals (Sweden)

    Daneshi Navab

    2014-06-01

    Full Text Available Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2 2014: 276-286

  11. Yield of a Choctawhatchee Sand Pine Plantation at Age 28

    Science.gov (United States)

    Russell M. Burns; R.H. Brendemuehl

    1969-01-01

    A little-known tree, Choctawhatchee sand pine (Pinus clausa [Chapm.] Vasey), seems well adapted to the infertile, droughty soils common to the sandhills of Florida which now produce little value. Published yield data based on plantation-grown Choctawhatchee sand pine are not available. One 28-year-old plantation of this race of sand pine, growing...

  12. Fresh groundwater resources in a large sand replenishment

    NARCIS (Netherlands)

    Huizer, Sebastian; Oude Essink, G.H.P.; Bierkens, Marc

    2016-01-01

    The anticipation of sea-level rise and increases in extreme weather conditions has led to the initiation of an innovative coastal management project called the Sand Engine. In this pilot project a large volume of sand (21.5 million m3) – also called sand replenishment or nourishment – was placed on

  13. 77 FR 75007 - Importation of Sand Pears From China

    Science.gov (United States)

    2012-12-19

    ... Health Inspection Service 7 CFR Part 319 RIN 0579-AD42 Importation of Sand Pears From China AGENCY... and vegetables regulations to allow the importation of sand pears (Pyrus pyrifolia) from China into the United States. As a condition of entry, sand pears from areas in China in which the Oriental...

  14. Design and management of conventional fluidized-sand biofilters

    Science.gov (United States)

    Fluidized sand biofilters (FSBs) are relatively compact, efficient, and cost-competitive biofilters, especially in recirculating systems that require maintaining consistently low levels of ammonia and nitrite. Filter sand is low cost (often $70-200/m3 of sand delivered) and has a high specific surf...

  15. Mineral processing of heavy mineral sands from Malawi and Malaysia

    OpenAIRE

    Mitchell, C J

    1992-01-01

    Processing of heavy mineral sands involves many techniques including gravity, magnetic and electrostatic separation. As part of a laboratory programme to develop effective mineral processing techniques, two mineral sands from Malawi and Malaysia were processed using the standard techniques, with emphasis placed on the Carpco electrostatic separator. These sands were initially characterised mineralogically by scanning electron microscopy (SEM), electron microprobe analysis (EPMA...

  16. Oil sands thickened froth treatment tailings exhibit acid rock drainage potential during evaporative drying.

    Science.gov (United States)

    Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

    2015-02-01

    Bitumen extraction from oil sands ores after surface mining produces different tailings waste streams: 'froth treatment tailings' are enriched in pyrite relative to other streams. Tailings treatment can include addition of organic polymers to produce thickened tailings (TT). TT may be further de-watered by deposition into geotechnical cells for evaporative drying to increase shear strength prior to reclamation. To examine the acid rock drainage (ARD) potential of TT, we performed predictive analyses and laboratory experiments on material from field trials of two types of thickened froth treatment tailings (TT1 and TT2). Acid-base accounting (ABA) of initial samples showed that both TT1 and TT2 initially had net acid-producing potential, with ABA values of -141 and -230 t CaCO₃ equiv. 1000 t(-1) of TT, respectively. In long-term kinetic experiments, duplicate ~2-kg samples of TT were incubated in shallow trays and intermittently irrigated under air flow for 459 days to simulate evaporative field drying. Leachates collected from both TT samples initially had pH~6.8 that began decreasing after ~50 days (TT2) or ~250 days (TT1), stabilizing at pH~2. Correspondingly, the redox potential of leachates increased from 100-200 mV to 500-580 mV and electrical conductivity increased from 2-5 dS m(-1) to 26 dS m(-1), indicating dissolution of minerals during ARD. The rapid onset and prolonged ARD observed with TT2 is attributed to its greater pyrite (13.4%) and lower carbonate (1.4%) contents versus the slower onset of ARD in TT1 (initially 6.0% pyrite and 2.5% carbonates). 16S rRNA gene pyrosequencing analysis revealed rapid shift in microbial community when conditions became strongly acidic (pH~2) favoring the enrichment of Acidithiobacillus and Sulfobacillus bacteria in TT. This is the first report showing ARD potential of TT and the results have significant implications for effective management of pyrite-enriched oil sands tailings streams/deposits. Copyright © 2014

  17. Effects of Wet Tray Seedling in Shallow Water on Temperature in Tray and Growth and Development and Biological Characteristics of Tobacco Seedlings%浅水湿润托盘育苗对盘内温度及烤烟生长发育及生物学性状的影响

    Institute of Scientific and Technical Information of China (English)

    金祥; 田必文; 陈风雷; 温明霞; 罗贞宝; 龙胜贤

    2013-01-01

    [目的]探讨烤烟浅水湿润托盘育苗的优势,为其广泛应该提供理论依据.[方法]以漂浮育苗为对照,研究烤烟浅水湿润托盘育苗时盘内温度及烟苗生长状况.[结果]浅水湿润托盘盘内温度较漂浮育苗盘内温度高0.4℃,出苗率相当,苗龄、移栽期、单株苗重、根系情况等方面均优于漂浮育苗.用该技术所育烟苗素质较好,栽后还苗期短,烟株长势较为旺盛,有利于烟叶产量、质量的提高.另外,较少的育苗用水量,有利于缓解干旱地区烤烟育苗的用水压力,减少育苗成本.[结论]浅水湿润托盘育苗技术充分继承了漂浮育苗技术和托盘育苗技术的优点,在烤烟育苗中有着广阔的应用空间.%[Objective] The aim was to discuss the advantage of tobacco wet tray seedling in shallow water,to provide a theoretical basis for its application widely.[Method] Taking floating seedling as control,temperature in tray and tobacco seedlings growth status were stuaied of the wet tray seedling in shallow water were studied.[Result] Temperature of wet tray seedling in shallow water was higher than that of floating seedling by 0.4 ℃,their seedling emergence rate was considerable,seedling age,transplanting period,plant seedling weight,root system were better than that of floating seedling.The tobacco seedlings bred by this technology was good,their seedling stage was short after planting,their growth vigor was vigorous,so was favor of improving tobacco leaf yield and quality.What' s more,less water consumption of seedling was favor of relieving the water use pressure of tobacco seedling breeding in Arid regions,and reducing the seedling breeding cost.[Conclusion] Seedling technology of shallow water wet tray fully inherits the advantages of floating seedling technology and tray seedling technology,has the rapid development space during tobacco seedling.

  18. The Rheology of Acoustically Fluidized Sand

    Science.gov (United States)

    Conrad, J. W.; Melosh, J.

    2013-12-01

    The collapse of large craters and the formation of central peaks and peak rings is well modeled by numerical computer codes that incorporate the acoustic fluidization mechanism to temporarily allow the fluid-like flow of rock debris immediately after crater excavation. Furthermore, long runout landslides require a similar mechanism to explain their almost frictionless movement, which is probably also a consequence of their granular composition coupled with internal vibrations. Many different investigators have now confirmed the ability of vibrations to fluidize granular materials. Yet it still remains to fully describe the rheology of vibrated sand as a function of stress, frequency and amplitude of the vibrations in the sand itself. We constructed a rotational viscometer to quantitatively investigate the relation between the stress and strain rate in a horizontal bed of strongly vibrated sand. In addition to the macroscopic stain rate, the amplitude and frequency of the vibrations produced by a pair of pneumatic vibrators were also measured with the aid of miniaturized piezoelectric accelerometers (B&K 4393) whose output was recorded on a digital storage oscilloscope. The initial gathering of the experimental data was difficult due to granular memory, but by having the sand compacted vibrationally for 8 minutes before each run the scatter of data was reduced and we were able to obtain consistent results. Nevertheless, our major source of uncertainty was variations in strain rate from run to run. We find that vibrated sand flows like a highly non-Newtonian fluid, in which the shear strain rate is proportional to stress to a power much greater than one, where the precise power depends on the amplitude and frequency of the applied vibrations. Rapid flow occurs at stresses less than half of the static yield stress (that is, the yield stress when no vibration is applied) when strong vibrations are present. For a Newtonian fluid, such as water, the relation between

  19. Carbon XANES Data from Six Aerogel Picokeystones Cut from the Top and Bottom Sides of the Stardust Comet Sample Tray

    Science.gov (United States)

    Wirick, S.; Flynn, G. J.; Frank, D.; Sandford, S. A.; Zolensky, M. E.; Tsou, P.; Peltzer, C.; Jacobsen, C.

    2009-01-01

    Great care and a large effort was made to minimize the amount of organic matter contained within the flight aerogel used to collect Comet 81P/Wild 2 samples. Even so, by the very nature of the production process and silica aerogel s affinity for volatile organics keeping silica aerogel free from organics is a monumental task. Silica aerogel from three production batches was flown on the Stardust sample return mission. All 3 types had layered densities varying from 5mg/ml to 50 mg/ml where the densest aerogel was farthest away from the collection area. A 2 step gelation process was used to make the flight aerogel and organics used in this process were tetraethylorthosilicate, ethanol and acetonitrile. Both ammonium hydroxide and nitric acid were also used in the aerogel production process. The flight aerogel was baked at JPL at 300 C for 72 hours, most of the baking was done at atmosphere but twice a day the oven was pumped to 10 torr for hour [1]. After the aerogel was baked it was stored in a nitrogen purged cabinet until flight time. One aerogel cell was located in the SRC away from any sample collection area as a witness to possible contamination from out gassing of the space craft, re-entry gases and any other organic encounter. This aerogel was aerogel used in the interstellar collection sample tray and is the least dense of the 3 batches of aerogel flown. Organics found in the witness tile include organics containing Si-CH3 bonds, amines and PAHS. Besides organic contamination, hot spots of calcium were reported in the flight aerogel. Carbonates have been detected in comet 81P/Wild2 samples . During preflight analyses, no technique was used to analyze for carbonates in aerogel. To determine if the carbonates found in 81P/Wild2 samples were from the comet, it is necessary to analyze the flight aerogel for carbonate as well as for organics.

  20. Locomotory transition from water to sand and its effects on undulatory kinematics in sand lances (Ammodytidae).

    Science.gov (United States)

    Gidmark, Nicholas J; Strother, James A; Horton, Jaquan M; Summers, Adam P; Brainerd, Elizabeth L

    2011-02-15

    Sand lances, fishes in the genus Ammodytes, exhibit a peculiar burrowing behavior in which they appear to swim rapidly into the substrate. They use posteriorly propagated undulations of the body to move in both water, a Newtonian fluid, and in sand, a non-Newtonian, granular substrate. In typical aquatic limbless locomotion, undulations of the body push against water, which flows because it is incapable of supporting the static stresses exerted by the animal, thus the undulations move in world space (slipping wave locomotion). In typical terrestrial limbless locomotion, these undulations push against substrate irregularities and move relatively little in world space (non-slipping wave locomotion). We used standard and X-ray video to determine the roles of slipping wave and non-slipping wave locomotion during burrowing in sand lances. We find that sand lances in water use slipping wave locomotion, similar to most aquatic undulators, but switch to non-slipping waves once they burrow. We identify a progression of three stages in the burrowing process: first, aquatic undulations similar to typical anguilliform locomotion (but without head yaw) push the head into the sand; second, more pronounced undulations of the aquatic portion of the body push most of the animal below ground; third, the remaining above-ground portion of the body ceases undulation and the subterranean portion takes over, transitioning to non-slipping wave locomotion. We find no evidence that sand lances use their body motions to fluidize the sand. Instead, as soon as enough of the body is underground, they undergo a kinematic shift and locomote like terrestrial limbless vertebrates.

  1. Longshore sediment transport at Golden Sands (Bulgaria

    Directory of Open Access Journals (Sweden)

    Hristo Nikolov

    2006-09-01

    Full Text Available The paper presents the results of studies on the qualitative and quantitative features of the littoral drift at Golden Sands (Bulgaria, carried out jointly by Polish and Bulgarian researchers. The mathematical modelling of physical coastal processes took wave transformation (wave diffraction and refraction; the effects of shoaling and wave breaking and longshore sediment transport into account. The computations were carried out for the mean statistical annual wave climate, determined on the basis of IO BAS wave data, simulated using the WAM method from long-term Black Sea wind data. The results of sediment transport computations clearly show that its direction off the Golden Sands shore is from north to south.

  2. Post-liquefaction reconsolidation of sand.

    Science.gov (United States)

    Adamidis, O; Madabhushi, G S P

    2016-02-01

    Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

  3. Three dimensional fabric evolution of sheared sand

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Alsidqi; Alshibli, Khalid (UWA)

    2012-10-24

    Granular particles undergo translation and rolling when they are sheared. This paper presents a three-dimensional (3D) experimental assessment of fabric evolution of sheared sand at the particle level. F-75 Ottawa sand specimen was tested under an axisymmetric triaxial loading condition. It measured 9.5 mm in diameter and 20 mm in height. The quantitative evaluation was conducted by analyzing 3D high-resolution x-ray synchrotron micro-tomography images of the specimen at eight axial strain levels. The analyses included visualization of particle translation and rotation, and quantification of fabric orientation as shearing continued. Representative individual particles were successfully tracked and visualized to assess the mode of interaction between them. This paper discusses fabric evolution and compares the evolution of particles within and outside the shear band as shearing continues. Changes in particle orientation distributions are presented using fabric histograms and fabric tensor.

  4. Rational approach to anisotropy of sand

    Science.gov (United States)

    Wu, Wei

    1998-11-01

    The paper presents a constitutive model for the three-dimensional deformation-strength behaviour of inherently anisotropic sand. Based on non-linear tensorial functions, the model is developed without recourse to the concepts in plasticity theory such as yield surface and plastic potential. Benefited from the fact that no decomposition of strain into elastic and plastic parts is assumed, a unified treatment of anisotropic behaviour of deformation and strength is achieved. Anisotropy is characterized by a vector normal to the bedding plane. The extension of the constitutive model is furnished by incorporating the vector under consideration of the principle of objectivity and the condition of material symmetry. Distinct features of the model are its elegant formulation and its simple structure involving few material parameters. Model performance and comparison with experiments show that the model is capable of capturing the salient behaviour of anisotropic sand.

  5. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    Global applications of pesticides in agricultural production have led to the detection of trace amounts of pesticides in groundwater resources in levels exceeding the EU threshold limit for drinking water of 0.1 µg L-1. Pesticide-polluted groundwater may be remediated by inoculating waterworks sand...... filters with specific degrading bacteria. However, degradation efficiency is often hampered by poor adhesion and a lack of sustained catabolic activity of the introduced bacteria. The overall objective of this thesis was to investigate the significance of selected bacterial surface properties...... coincided with efficient mineralisation/degradation, and proposed the tfdC gene as a suitable marker for monitoring phenoxy acid degradation in strain PM2. Furthermore, when testing strain PM2s degradation performance in flow-through sand columns, we found that strain PM2 was able to sustain induced...

  6. Analysis of Wind-blown Sand Movement over Transverse Dunes

    Science.gov (United States)

    Jiang, Hong; Huang, Ning; Zhu, Yuanjian

    2014-12-01

    Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.

  7. Field Measurements of Influence of Sand Transport Rate on Structure of Wind-sand Flow over Coastal Transverse Ridge

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang; S L NAMIKAS; P A HESP; MA Jun

    2008-01-01

    The structure of wind-sand flow under different total sand transport rates was measured with field vertical anemometer and sand trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Province,which is one of the most typical coastal aeolian distribution regions in China and famous for the tall and typical coastal transverse ridges.The measurement results show that,on the conditions of approximate wind velocities and same surface materials and environments,some changes happen to the structure of wind-sand flow with the increase of total sand transport rate on the crest of coastal transverse ridge.First,the sand transport rates of layers at different heights in the wind-sand flow increase,with the maximum increase at the height layer of 4-8cm.Second,the ratios of sand transport rates of layers at different heights to total sand transport rate decrease at the low height layer (0-4cm),but increase at the high height layer (4-60cm).Third,the distribution of the sand transport rate in the wind-sand flow can be expressed by an exponential function at the height layer of 0-40cm,but it changes fi'om power function model to exponential function model in the whole height layer (0-60cm) and changes into polynomial function model at the height layer of 40-60cm with the increase of total sand transport rate.Those changes have a close relationship with the limit of sand grain size of wind flow transporting and composition of sand grain size in the wind-sand flow.

  8. Study of the anti-sand sucker rod pump

    Science.gov (United States)

    Wei, Hangxin; Lv, Bingxin; Xi, Wenkui; Yi, Peng

    2017-06-01

    In order to solve the problem of sand stuck in the sucker rod pump, an anti-sand sucker rod pump is designed. The anti-sand sucker rod pump includes the conventional sucker rod pump and the swirl flow device. The sand particles can be separated from the oil in the swirl flow device, so the plunger of the sucker rod pump cannot be stuck. The motion equation of the sand particles in oil is deduced. The virtual model of the swirl flow device is built in GAMBIT software. And simulation of solid-liquid two phase flow is simulated in software FLUENT. The simulation results show that the swirl flow device can realize the sand particles separation from the oil completely. So the pump can have the effect of anti-sands.

  9. Strength and sintering effects at ejection of explosively driven sand

    Science.gov (United States)

    Resnyansky, A. D.; Weckert, S. A.

    2014-05-01

    A description of the response of sand to extreme loads is very important for the evaluation of the sand ejecta impact effects on various targets. Sand is a complex material to simulate because of its porosity where the inter-phase equilibrium is hard to achieve under transient shock wave loading. A previously developed two-phase model with strength has been implemented in CTH and applied to sand. The shock response of the sand, including the Hugoniot abnormality known from the literature for highly porous silica, is adequately described with the material model. The sand unloading effects appearing as the ejecta are observed in the present work using dynamic flash X-ray of an aluminium target plate loaded by limestone sand ejecta from the detonation of a buried high explosive charge. The CTH modelling results compared with the flash X-ray images have demonstrated good agreement, particularly, in the description of momentum transfer to the target.

  10. A transport-rate model of wind-blown sand

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sand transport by wind plays an important role in environmental problems.Formulating the sand-transport rate model has been of continuing significance,because the majority of the existing models relate sand-transport rate to the wind-shear velocity.However,the wind-shear velocity readapted to blown sand is difficult to determine from the measured wind profiles when sand movement occurs,especially at high wind velocity.Detailed wind tunnel tests were carried out to reformulate the sand-transport rate model,followed by attempts to relate sand-transport rate to parameters of wind velocity,threshold shear-velocity,and grain size.Finally,we validated the model based on the data from field observations.

  11. Athabasca oil sands development : lessening the footprint

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, R. [Alberta Environment, AB (Canada)

    2005-07-01

    This presentation provided an overview of the oil sands development footprint from the perspectives of industry, environmental associations and regulatory agencies. A map of regional oil sands developments was presented along with details of land disturbance to date. Industry strategies for lessening the impact of land disturbance include compact space-efficient mining operations; good planning; and effective, progressive reclamation. A closure and reclamation model was presented, along with key reclamation challenges such as overburden. Issues concerning tailings sands were examined. Details of Syncrude's closure vision were presented, including details of the Mildred Lake site. Details of the Fort McMurray Environmental Association were presented as well as various regional multi-stakeholder initiatives. A background of Syncrude and Suncor operations was presented as well as development projection forecasts. Impacts to the Boreal region were examined. Details of land reclamation by Syncrude were provided, as well as a chart of cumulative disturbances. It was noted that recent applications have indicated numerous reclamation uncertainties, including long-term performance of landforms and the feasibility of developing trafficable tailings landforms. It was suggested that the ecosystem dynamics of the Boreal are poorly understood. Exacerbating factors include the degraded state of soils; viability of end pit lakes; and climate change. It was suggested that operators are proposing to deal with landscape and technology uncertainty using adaptive management strategies. Government responses to the oil sand development footprint include the encouragement of more research into tailings technologies, end pit lake viability and reclamation; and the identification of regional landscape ecological thresholds by the Cumulative Environmental Management Association (CEMA). It was concluded that uncertainty needs to be addressed via a variety of policy and management options

  12. Pullout capacity of batter pile in sand.

    Science.gov (United States)

    Nazir, Ashraf; Nasr, Ahmed

    2013-03-01

    Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21-31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18-75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted.

  13. Kirsten Sand. Arkitekt for sin tid

    Directory of Open Access Journals (Sweden)

    Elisabeth Seip

    2015-12-01

    Full Text Available Towards the end of World War II the retreating Germans burnt down nearly all buildings and other constructions in the counties of Finnmark and the northern parts of Troms in North Norway. The population evacuated but many returned as soon as possible, only to find themselves homeless. At this very demanding point Kirsten Sand decided to travel north, and do whatever she could as an architect to help. The pre-war housing situation was generally difficult. Low building standards and lack of money forced families in the cities to live under bad conditions. Kirsten Sand studied these conditions and took part in the efforts to better the situation. This knowledge provided a good starting point for the work she undertook after the war, in particular her profound understanding of the situation of women, their working conditions and positions in the household and society. Houses designed by Sand and her helpmates are simple but adequate, taking into account these women’s point of view. Ingebjørg Hage has thrown light on the work of Kirsten Sand in Finnmark and Troms in several ways. This article aims at describing Sand’s background as an architect before she left Oslo to travel north. It describes how housing and housing policy since long had been central to architects, especially so within the group she belonged to. In pre-war Oslo she had been engaged in planning and designing hospitals. During a period as inspector for the health authorities she learned a lot about the living conditions of people in general. After establishing her own architect’s office she mostly designed family houses, and during the war she engaged in research that further deepened her knowledge in the field. Thus she was particularly well equipped for the demanding tasks she undertook in the summer of 1945.

  14. Pullout capacity of batter pile in sand

    Directory of Open Access Journals (Sweden)

    Ashraf Nazir

    2013-03-01

    Full Text Available Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21–31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18–75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted.

  15. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  16. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  17. Guide to preparing SAND reports. Revised

    Energy Technology Data Exchange (ETDEWEB)

    Locke, T.K. [ed.

    1996-04-01

    This guide contains basic information needed to produce a SAND report. Its guidelines reflect DOE regulation and Sandia policy. The guide includes basic writing instructions in an annotated sample report; guidance for organization, format, and layout of reports produced by line organizations; and information about conference papers, journal articles, and brochures. The appendixes contain sections on Sandia`s preferred usage, equations, references, copyrights and permissions, and publishing terms.

  18. Sorption of Arsenite onto Mackinawite Coated Sand

    Science.gov (United States)

    Gallegos, T. J.; Hayes, K. F.; Abriola, L. M.

    2004-05-01

    Arsenic contamination of groundwater is a widespread problem affecting aquifers in the United States as well as abroad. Recent strengthening of the US EPA MCL for arsenic has prompted the need for technology capable of removing both arsenite and arsenate from solution. Arsenite, the more toxic form of arsenic, is more difficult to remove from anoxic zones in the subsurface. Studies by others have demonstrated the affinity of some types of iron sulfides for arsenite, such as troilite, pyrite, amorphous iron sulfide and mackinawite. However, these studies have not provided a comprehensive investigation of the macroscopic behavior of arsenite in the presence of crystalline mackinawite in a form that can be readily applied to real-world treatment technologies. This study examines the behavior of arsenite in the presence of mackinawite coated sand. PH edge results demonstrate that arsenite sorption onto mackinawite coated sand increases with increasing pH, reaching maximum removal at pH 10. Arsenite removal, albeit slight, occurring below pH 5 is independent of pH indicative of a different removal mechanism. Isotherm studies show that at low concentrations, removal is Langmuirian in nature. Arsenite sorption abruptly converts to linear behavior at high concentrations, possibly attributed to the saturation of the monolayer. Ionic strength effects were assessed by comparing pH edge data developed for three different concentrations of NaCl background electrolyte solution. Increases in ionic strength enhance the removal of arsenite from solution, suggesting possible inner-sphere surface complexation removal mechanisms. Information gathered in this study can be used to further develop surface complexation models to describe and predict reactivity of arsenite in the presence of mackinawite coated sands in anoxic regions. Mackinawite coated sands investigated here may provide a feasible reactive medium for implementation in above-ground sorption reactors or subsurface

  19. PHYSICAL MODELING OF ODOMETRIC COMPRESSION OF SAND

    Directory of Open Access Journals (Sweden)

    Lyashenko P. A.

    2016-10-01

    Full Text Available The odometric compression of sand with constant rate of loading (CRL or constant rate of deformation (CRD and continuous registration of the corresponding reaction allows to identify the effect of stepwise changes of deformation (at the CRL and the power reaction (at the CRD. Physical modeling of compression on the sandy model showed the same effect. The physical model was made of fine sand with marks, mimicking large inclusions. Compression of the soil at the CRD was uneven, stepwise, and the strain rate of the upper boundary of the sandy model changed cyclically. Maximum amplitudes of cycles passed through a maximum. Inside of the sand model, the uneven strain resulted in the mutual displacement of the adjacent parts located at the same depth. The growth of external pressure, the marks showed an increase or decrease in displacement and even move opposite to the direction of movement (settlement the upper boundary of the model ‒ "floating" of marks. Marks, at different depths, got at the same time different movements, including mutually contradictory. The mark settlements sudden growth when the sufficiently large pressure. These increments in settlements remained until the end of loading decreasing with depth. They were a confirmation of the hypothesis about the total destruction of the soil sample at a pressure of "structural strength". The hypothesis of the "floating" reason based on the obvious assumption that the marks are moved together with the surrounding sand. The explanation of the effect of "floating" is supported by the fact that the value of "floating" the more, the greater the depth

  20. Sand Ripple Dynamics on the Inner Shelf

    Science.gov (United States)

    2006-01-01

    Sand Ripple Dynamics on the Inner Shelf Donald N. Slinn Department of Civil and Coastal Engineering, University of Florida Gainesville, FL 32611...Florida,Department of Civil and Coastal Engineering,Gainesville,FL,32611-6590 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY...2002. 452: p. 1-24. Acrivos, A., Shear-Induced Particle Diffusion in Concentrated Suspensions of Noncolloidal Particles. Journal of Rheology , 1995

  1. Drawing a Line in the Sand

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    An Inner Mongolian woman takes on the desert and converts extensive arid regions into arable land by Ni Yanshuo CONVERTING vast tracks of desert into arable land is no easy task, even using the most advanced technology.Yet a woman who hails from north China’s Inner Mongolia Autonomous Region met this challenge head on.Using the helping hands of other determined women,she has made remarkable progress in pushing back the sands of time.

  2. Drained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Praastrup, U.; Jakobsen, Kim Parsberg

    In the process of understanding and developing models for geomaterials, the stress-strain behaviour is commonly studied by performing triaxial tests. In the present study static triaxial tests have been performed to gain knowledge of the stress-strain behaviour of frictional materials during...... monotonic loading. The tests reported herein are all drained tests, starting from different initial states of stress and following various stress paths. AIl the tests are performed on reconstituted medium dense specimens of Eastern Scheldt Sand....

  3. Waste foundry sand: Environmental implication and characterization

    Directory of Open Access Journals (Sweden)

    Gabriela Penkaitis

    2012-12-01

    Full Text Available This paper presents the results of analyses using Scanning Electron Microscopy in field samples of waste foundry sand, as well as the results of granulometric, chemical and groundwater analyses. Field data allowed to characterize waste foundry sand and showed that there are elevated concentrations of metals in the groundwater (iron, manganese, boron and selenium, in addition to other potentially toxic elements (chromium, copper, cobalt, nickel, zinc, aluminum, iron, manganese, which are present in the waste and are considered not hazardous by current standards. Even if these elements are not considered hazardous, their concentrations above the permissible limit compromise the environmental quality of the site, posing risks to the local population, since they work in agriculture and use groundwater. Two different types of waste foundry sands were identified using granulometric analyses. Electron microscopy showed features related to morphological, chemical and mineralogical characteristics of grains that make up the waste. Quartz was the dominant mineral. Waste foundry sand is composed of two types of grains: a rounded grain with almost no incrustations formed during alloy production, and a second type of grain, which is not rounded, has incrustations, and always has several metals derived from alloys and associated with these incrustations. Chemical elements detected in groundwater with concentrations above the limits established by the regulatory bodies were found in wells located in the landfill area. Most of these elements show higher concentrations downstream, some of them with concentrations above the regulatory limit, and others show an increase in concentration upstream, indicating that the landfill may be impacting the local environment.

  4. American Las Vegas Sands Corp. Visiting Beijing

    Institute of Scientific and Technical Information of China (English)

    Li Yinghong; Liu Jinliang

    2006-01-01

    @@ On August 29, Wan Jifei, Chairman of CCPIT, meets the visiting delegation led by Sheldon G. Adelson,Chairman of the Board and principal owner of Las Vegas Sands Corp. in CCPIT. Zhao Zhenge, Vice Director of International Connection Department of CCPIT, Luo Guoxiong from Beijing China Exhibition Investment Company, Xu Jingyi, Assistant Director of American and Oceanian Affairs Division of CCPIT, also attended the meeting.

  5. Accuracy of Two Types of Tray for Mobile Teeth during Impression Procedure%2种托盘制取松动基牙模型的精度比较

    Institute of Scientific and Technical Information of China (English)

    危薇

    2012-01-01

    目的:评价成品托盘和个别托盘使用海藻酸盐印模材料对松动牙取模时模型的精度的影响.方法:用成品托盘和个别托盘对同一松动牙模型取模,各制得20个超硬人造石模型.使用电子游标卡尺测量取得的人造石模型上标各记点间距离,测量精度为0.001 mm,将测得数据进行统计分析.结果:采用2种托盘对松动牙取模精度无显著性差异,2种托盘对于松动牙取模精度均已超出临床所允许范围.结论:当使用海藻酸盐作为印模材料时,成品托盘和按照常规方法制作的个别托盘不适于松动牙的取模,及对于松动牙,应尽可能避免使用海藻酸盐印模材料.%Objective: To investigate the accuracy of stock tray and custom tray for the mobile teeth during the impression procedure with alginate as impression material. Methods: 20 artificial stone replication models were made for stock tray and custom tray with alginate on the same master model of mobile tooth respectively. The dimensions between landmarks on the master and artifical stone were measured with an electronic caliper. ANOVA was used to compare the measurements. Results; There was no significant difference of stock tray and custom tray when taking impression for the mobile teeth. The accuracy of the two kinds of tray were both beyond the clinical requiment. Conclusion; The stock tray and custom tray made in the experiment are not adequeat for mobile teeth impression taking when the alginate was used.

  6. Oil sands mining water use and management

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Long, D.; Fitch, M. [Golder Associates Ltd., Calgary, AB (Canada)

    2010-07-01

    There are currently 4 bitumen mining operations operating along the Athabasca River in northern Alberta. This paper presented details of the water licences, historical water use, present water use, and future plans for water management in relation to oil sands mining operations. The study was based on work currently conducted for the Oil Sands Developers Group (OSDG) and Canadian Association of Petroleum Producers (CAPP), as well as on mine site water balance analyses for proposed mines in the region. Typical mine site water balances were discussed, and water use rates for the mining operations were reviewed. The new Athabasca River water management framework may require that mines provide additional water storage or delayed reclamation of mine areas in order to offset water losses during winter low-flow periods. New regulations may also reduce the requirement for make-up water. The study also noted that release criteria are still being developed for on-site water within closed-loop mine operations. The oil sands industry will need to balance various factors related to water use in the future. 5 refs., 3 figs.

  7. DYNAMIC EFFECTIVE SHEAR STRENGTH OF SATURATED SAND

    Institute of Scientific and Technical Information of China (English)

    邵生俊; 谢定义

    2002-01-01

    The dynamic effective shear strength of saturated sand under cyclic loading is discussed in this paper. The discussion includes the transient time dependency behaviors based on the analysis of the results obtained in conventional cyclic triaxial tests and cyclic torsional shear triaxial tests. It has been found that the dynamic effective shear strength is composed of effective frictional resistance and viscous resistance, which are characterized by the strain rate dependent feature of strength magnitude, the coupling of consolidation stress with cyclic stress and the dependency of time needed to make the soil strength suffciently mobilized, and can also be expressed by the extended Mohr-Coulomb's law. The two strength parameters of the dynamic effective internal frictional angle φd and the dynamic viscosity coefficient η are determined. The former is unvaried for different number of cyclic loading, dynamic stress form and consolidation stress ratio. And the later is unvaried for the different dynamic shear strain rate γt developed during the sand liquefaction, but increases with the increase of initial density of sand. The generalization of dynamic effective stress strength criterion in the 3-dimensional effective stress space is studied in detail for the purpose of its practical use.

  8. Collaborative production management for oil sands operations

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Andrew [Matrikon (Canada)

    2011-07-01

    This paper gives an overview of the collaborative production management of oil sands operations. Some characteristics of oil sands operations include oil treatment, hydro treating, diluent addition, logistics, and environmental impact assessments. Some of the business challenges include regulatory uncertainty, a fluid workforce and a technology still in the process of being developed. Improvement is only possible when process is assessed and measured; hence, production data management is very important. Production data measurements encompass such areas as planning, documentation and transactions. Regulatory data reporting is represented using a flow chart. The concepts of business application architecture and functional reference modeling are also explained. Benchmarking plays a vital role, some aspects of which would be technology, automation and integration. Certain advantages of timely assessment are increased production, equity, and goodwill as well as reduction in costs, risk, and capital requirements. The relevance and importance of collaboration, awareness of web technology and aggregate information are also explained. From the study, it can be concluded that the key to overall improvement in the oil sands industry will be improved production management.

  9. Recycled sand in lime-based mortars.

    Science.gov (United States)

    Stefanidou, M; Anastasiou, E; Georgiadis Filikas, K

    2014-12-01

    The increasing awareness of the society about safe guarding heritage buildings and at the same time protecting the environment promotes strategies of combining principles of restoration with environmentally friendly materials and techniques. Along these lines, an experimental program was carried out in order to investigate the possibility of producing repair, lime-based mortars used in historic buildings incorporating secondary materials. The alternative material tested was recycled fine aggregates originating from mixed construction and demolition waste. Extensive tests on the raw materials have been performed and mortar mixtures were produced using different binding systems with natural, standard and recycled sand in order to compare their mechanical, physical and microstructure properties. The study reveals the improved behavior of lime mortars, even at early ages, due to the reaction of lime with the Al and Si constituents of the fine recycled sand. The role of the recycled sand was more beneficial in lime mortars rather than the lime-pozzolan or lime-pozzolan-cement mortars as a decrease in their performance was recorded in the latter cases due to the mortars' structure.

  10. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described...... in the succeeding sections. Finally the test results are briefly summarised and a relationship between void ratio l and permeability is established....

  11. The bituminous sands : a Canadian mirage?

    Energy Technology Data Exchange (ETDEWEB)

    Rousse, D.R. [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees; Nasr, G.J. [Lebanese Univ., Roumieh (Lebanon). Faculty of Engineering; Turcotte, S.F. [Quebec Univ., Montreal, PQ (Canada). Centre d' Etudes Internationales et Mondialisation; Salah, N.B. [Ecole Superieure des Sciences et Techniques De Tunis, Tunis (Tunisia). LMMP

    2009-07-01

    This paper examined the controversy about the potential role of a significant increase in Canadian oil sands production in order to bridge the upcoming gap between the world's increasing energy demand and the total recoverable oil supply. The paper presented the actual potential of different scenarios and considered the prediction cost forecasts. A brief overview of environmental impacts and the real return on investments were also provided. Environmental impacts that were considered included land degradation; water contamination; ecosystem damage; and air pollution. Nuclear energy was also presented as a possible solution. The paper demonstrated that even in a very optimistic scenario, Canada's oil sands accelerated production has a negligible effect on the aforementioned gap, has a considerable impact on environment that has yet to be accounted for. Energy ratios that were presented included energy return on energy investment; energy available on energy used; and energy payback. It was concluded that enhanced recovery techniques are clearly needed for future sustainable exploitation of these bituminous sands. 32 refs., 1 fig.

  12. Summertime View of North Polar Sand Dunes

    Science.gov (United States)

    2006-01-01

    10 October 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of dunes in one of the several north polar dune fields. The bright surfaces adjacent to some of the dunes are patches of frost. These dunes spend much of the autumn, winter, and spring seasons covered with carbon dioxide frost. Only in late spring and in summer are the dark windblown sands fully exposed. Over the course of the 9+ years of the MGS mission, the MOC team has sought evidence that sand dunes may be migrating downwind over time. However, no clear examples of the movement of a whole dune have been identified. On Earth, such movement is typically detectable in air photos of the smallest active dunes over periods of a few years. Owing to the fact that the north polar dunes spend much of each martian year under a cover of frost, perhaps these move much more slowly than their frost-free, terrestrial counterparts. The sand may also be somewhat cemented by ice or minerals, likewise preventing vigorous dune migration in the present environment. This view covers an area approximately 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left. The dunes are located near 79.8oN, 127.1oW, and the picture was acquired on 11 September 2006.

  13. The sedimentary structure of linear sand dunes

    Science.gov (United States)

    Bristow; Bailey; Lancaster

    2000-07-06

    Linear sand dunes--dunes that extend parallel to each other rather than in star-like or crescentic forms--are the most abundant type of desert sand dune. But because their development and their internal structure are poorly understood, they are rarely recognized in the rock record. Models of linear dune development have not been able to take into account the sub-surface structure of existing dunes, but have relied instead either on the extrapolation of short-term measurements of winds and sediment transport or on observations of near-surface internal sedimentary structures. From such studies, it has not been clear if linear dunes can migrate laterally. Here we present images produced by ground penetrating radar showing the three-dimensional sedimentary structure of a linear dune in the Namib sand sea, where some of the world's largest linear dunes are situated. These profiles show clear evidence for lateral migration in a linear dune. Moreover, the migration of a sinuous crest-line along the dune produces divergent sets of cross-stratification, which can become stacked as the dune height increases, and large linear dunes can support superimposed dunes that produce stacked sets of trough cross-stratification. These clear structural signatures of linear dunes should facilitate their recognition in geological records.

  14. Computational Fluid-dynamics of Liquid Phase Flow on Distillation Column Trays%利用计算流体力学方法研究精馏塔板上的液相流动

    Institute of Scientific and Technical Information of China (English)

    刘春江; 袁希钢

    2002-01-01

    A computational fluid-dynamics model is presented for predicting the two-phase two-dimensional liquid phase flow on a distillation column tray based on the modification of Navier-Stokes Equation by considering both the resistance and the enhanced turbulence created by the uprising vapor. Experimental measurement of the local liquid phase velocity on an air-water simulator of 1.2 m in diameter by using the hot film anemometer is briefly described. Two of the conventional fluid-dynaxmic constants are readjusted for the case of liquid flow on a tray by fitting the experimental data. The predicted local liquid phase velocity and direction of flow by the present model are confirmed satisfactorily by the authors' experimental measurements and by the data from literature. By the aid of the present model, the concentration field on the tray can be computed for the evaluation of the enhancement of liquid phase concentration across a tray. The advantages of applying computational fluid-dynamics to tray column design are discussed.

  15. Shaly sand formation evaluation in tight gas sands using electrochemical potential measurements

    Science.gov (United States)

    Sharma, M. M.; Jin, M.

    1991-08-01

    Equations are developed that directly relate the shaly conductivity to the electrochemical (membrane) potential (EP). The model is applied to both fully and partially saturated sands. The relationship between the resistivity index and the water saturation is also expressed in terms of a single membrane potential measurement. The Ep measured at different salinities are compared with model prediction using a single membrane potential measurement. Sigma (sub 0) versus Sigma (sub w) curves are then generated using the model equations and compared with measured curves. Experimental results are presented for electrochemical potential measurement made in the lab on 50 tight gs sand samples. It is shown that the measurements can be correlated with CEC although the CEC measured by grinding up the samples was always higher than that estimated from Ep measurements. The Ep measurements are combined with the equations for partial saturation developed in the report to obtain water saturations in a tight gas sand well. Through the example it is shown that it is possible to determine the water saturation in Shaly sands from one membrane potential measurement at a known salinity together with a set of resistivity logs. The results clearly demonstrate the applicability of the method as a practical procedure for Shaly sand information evaluation.

  16. Peripheral snap-fit locking mechanisms and smooth surface finish of tibial trays reduce backside wear in fixed-bearing total knee arthroplasty.

    Science.gov (United States)

    Łapaj, Łukasz; Mróz, Adrian; Kokoszka, Paweł; Markuszewski, Jacek; Wendland, Justyna; Helak-Łapaj, Celina; Kruczyński, Jacek

    2017-02-01

    Background and purpose - Severe backside wear, observed in older generations of total knee replacements (TKRs), led to redesign of locking mechanisms to reduce micromotions between tibial tray and inlay. Since little is known about whether this effectively reduces backside wear in modern designs, we examined backside damage in retrievals of various contemporary fixed-bearing TKRs. Patients and methods - A consecutive series of 102 inlays with a peripheral (Stryker Triathlon, Stryker Scorpio, DePuy PFC Sigma, Aesculap Search Evolution) or dovetail locking mechanism (Zimmer NexGen, Smith and Nephew Genesis II) was examined. Articular and backside surface damage was evaluated using the semiquantitative Hood scale. Inlays were examined using scanning electron microscopy (SEM) to determine backside wear mechanisms. Results - Mean Hood scores for articular (A) and backside (B) surfaces were similar in most implants-Triathlon (A: 46, B: 22), Genesis II (A: 55, B: 24), Scorpio (A: 57, B: 24), PFC (A: 52, B: 20); Search (A: 56, B: 24)-except the NexGen knee (A: 57, B: 60), which had statistically significantly higher backside wear scores. SEM studies showed backside damage caused by abrasion related to micromotion in designs with dovetail locking mechanisms, especially in the unpolished NexGen trays. In implants with peripheral liner locking mechanism, there were no signs of micromotion or abrasion. Instead, "tray transfer" of polyethylene and flattening of machining was observed. Interpretation - Although this retrieval study may not represent well-functioning TKRs, we found that a smooth surface finish and a peripheral locking mechanism reduce backside wear in vivo, but further studies are required to determine whether this actually leads to reduced osteolysis and lower failure rates.

  17. Impact on plate waste of switching from a tray to a trayless delivery system in a university dining hall and employee response to the switch.

    Science.gov (United States)

    Thiagarajah, Krisha; Getty, Victoria M

    2013-01-01

    A potential strategy for decreasing food waste in foodservice operations is trayless dining. The objective of this 2010 study was to compare the impact of using a tray vs a trayless system on plate waste and on employees' attitudes. To test the hypothesis that going trayless would reduce waste, liquid and solid plate waste were measured for 1 week with the then-existing tray system and again after a new trayless system was implemented in a buffet-style university dining hall serving roughly1,000 meals a day. Foodservice staff were invited to participate in a focus group about the impact on their jobs. The investigators calculated plate waste per patron under the two systems and used an independent samples t test to examine the significance of the difference. Comments from the focus group were analyzed for themes. A significant decrease in solid waste per patron (0.81 oz; P=0.001) was observed in switching from the tray to the trayless system (4.39 ± 0.24 oz vs 3.58 ± 0.08 oz per patron). A nonsignificant reduction was observed with liquid waste (49.77 ± 2.62 mL vs 46.36 ± 4.51 mL; P=0.18). Most of the employees preferred the trayless system as long as it did reduce waste, but felt that increased breakage of dishware and increased need to wipe down tables were possible concerns resulting from the switch. This study demonstrates that trayless dining can reduce plate waste, and that employees can be supportive of the change.

  18. Peripheral snap-fit locking mechanisms and smooth surface finish of tibial trays reduce backside wear in fixed-bearing total knee arthroplasty

    Science.gov (United States)

    Łapaj, Łukasz; Mróz, Adrian; Kokoszka, Paweł; Markuszewski, Jacek; Wendland, Justyna; Helak-Łapaj, Celina; Kruczyński, Jacek

    2017-01-01

    Background and purpose — Severe backside wear, observed in older generations of total knee replacements (TKRs), led to redesign of locking mechanisms to reduce micromotions between tibial tray and inlay. Since little is known about whether this effectively reduces backside wear in modern designs, we examined backside damage in retrievals of various contemporary fixed-bearing TKRs. Patients and methods — A consecutive series of 102 inlays with a peripheral (Stryker Triathlon, Stryker Scorpio, DePuy PFC Sigma, Aesculap Search Evolution) or dovetail locking mechanism (Zimmer NexGen, Smith and Nephew Genesis II) was examined. Articular and backside surface damage was evaluated using the semiquantitative Hood scale. Inlays were examined using scanning electron microscopy (SEM) to determine backside wear mechanisms. Results — Mean Hood scores for articular (A) and backside (B) surfaces were similar in most implants—Triathlon (A: 46, B: 22), Genesis II (A: 55, B: 24), Scorpio (A: 57, B: 24), PFC (A: 52, B: 20); Search (A: 56, B: 24)—except the NexGen knee (A: 57, B: 60), which had statistically significantly higher backside wear scores. SEM studies showed backside damage caused by abrasion related to micromotion in designs with dovetail locking mechanisms, especially in the unpolished NexGen trays. In implants with peripheral liner locking mechanism, there were no signs of micromotion or abrasion. Instead, “tray transfer” of polyethylene and flattening of machining was observed. Interpretation — Although this retrieval study may not represent well-functioning TKRs, we found that a smooth surface finish and a peripheral locking mechanism reduce backside wear in vivo, but further studies are required to determine whether this actually leads to reduced osteolysis and lower failure rates. PMID:27781667

  19. Produção de mudas de alface em bandejas e substratos comerciais Production of lettuce seedlings in different trays and commercial substrates

    Directory of Open Access Journals (Sweden)

    Paulo E. Trani

    2004-06-01

    Full Text Available Avaliou-se o desenvolvimento de mudas de alface (Lactuca sativa L. cv Vera produzidas em diferentes bandejas de poliestireno e em quatro substratos comerciais em um experimento em Campinas (SP, sob cultivo protegido, de 15/01 a 13/02/03. Os tratamentos consistiram na combinação fatorial de tipos de substratos (Plantmax HA, Hortimix folhosas, Golden Mix 47 e Vida Verde Tropstrato hortaliças e tamanhos de células em bandejas de poliestireno (200 e 288 células. O experimento foi disposto inteiramente ao acaso, com as parcelas subdivididas para época de avaliação, com três repetições sendo cada uma constituída de uma bandeja. As avaliações foram realizadas aos cinco, dez, quinze e vinte dias após a germinação sendo retiradas em cada uma, ao acaso, vinte plantas de cada bandeja. Foram avaliados suas alturas, número de folhas, estabilidade do torrão e a área foliar. O substrato Plantmax proporcionou aos 15 e 20 dias após a germinação, mudas de alface mais desenvolvidas em relação aos outros substratos. Independente do tipo de substrato, as bandejas de 200 células mostraram-se melhores que as de 288 células quanto ao número de folhas e área foliar por ocasião do transplante (20 dias.The effect of four commercial substrates in polystyrene trays with 200 and 288 cells, was evaluated on the production of seedlings of lettuce (Lactuca sativa cv. Vera in a plastic greenhouse, from 15/01 to 13/02/03, in Campinas, São Paulo State, Brazil. The treatments consisted of factorial combinations of four commercial substrates (Plantmax HA, Hortimix folhosas, Golden Mix 47 and, Vida Verde Tropstrato hortaliças and two cell sizes (200 and 288 cells. The experimental design was a randomized complete design, with the plots split with each part subdivided for the evalution time, with three repetitions, each beign made up of a tray. At 5; 10; 15 and 20 days after germination, twenty random plants from each plot were evaluated for their stem

  20. STUDY ON HOT SAND COOLING EQUIPMENT WITH DAMPING SAND CASCADE AND VERTICAL SPOUTED-FLUIDIZED BED

    Institute of Scientific and Technical Information of China (English)

    L.C. Wang; F. Wang; X.H. You

    2005-01-01

    A new kind of hot sand cooling equipment with vertical spouted-fluidized bed is developed in this paper. It is similar to the traditional horizontal vibrating fluidized boiling cooler in principle but different from it in structure. The processing principle of the cooler is analyzed. The influence of main structural and processing parameters on the cooling effect and its mechanism are researched. Other characteristics of the cooler are discussed also. Experiment results show that the cooling efficiency η is equal to or larger than 83%, the temperature of output sand is less than 40℃ with the temperature of input sand is about between 80 and 90℃, and the productivity is 5t/(h·m)

  1. Small Strain Behaviour and Viscous Effects on Sands and Sand-Clay Mixtures

    Science.gov (United States)

    Di Benedetto, H.

    This lecture paper focuses on sands and sand-clay mixtures behaviour in the small strain domain. Non viscous and viscous components are measured, identified and modelled within the framework of a 3 component model. Two precision prototype devices (triaxial and hollow cylinder) both equipped with piezoelectric sensors are used. Non viscous measured behaviour considering small quasi-static cycles and wave properties are compared with simulations obtained from 2 recently formulated anisotropic hypoelastic models (DBGS and DBGSP). Then, viscous experimental part is compared with the proposed model prediction. This model is an asymptotic expression, for the small strain domain, of a viscous evanescent formalism proposed by the author. It takes into account very peculiar behaviour observed on sands. Simulation for loadings with and without rotation of axes and for different rate histories, are quite satisfactory.

  2. Policy Analysis of the Canadian Oil Sands Experience

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2013-09-01

    For those who support U.S. oil sands development, the Canadian oil sands industry is often identified as a model the U.S. might emulate, yielding financial and energy security benefits. For opponents of domestic oil sands development, the Canadian oil sands experience illustrates the risks that opponents of development believe should deter domestic policymakers from incenting U.S. oil sands development. This report does not seek to evaluate the particular underpinnings of either side of this policy argument, but rather attempts to delve into the question of whether the Canadian experience has relevance as a foundational model for U.S. oil sands development. More specifically, this report seeks to assess whether and how the Canadian oil sands experience might be predictive or instructive in the context of fashioning a framework for a U.S. oil sands industry. In evaluating the implications of these underpinnings for a prospective U.S. oil sands industry, this report concentrates on prospective development of the oil sands deposits found in Utah.

  3. Cytotoxicity of yellow sand in lung epithelial cells

    Indian Academy of Sciences (India)

    Y H Kim; K S Kim; N J Kwak; K H Lee; S A Kweon; Y Lim

    2003-02-01

    The present study was carried out to observe the cytotoxicity of yellow sand in comparison with silica and titanium dioxide in a rat alveolar type II cell line (RLE-6TN). Yellow sand (China Loess) was obtained from the loess layer in the Gunsu Province of China. The mean particle diameter of yellow sand was about 0.003 ± 0.001 mm. Major elements of yellow sand were Si(27.7 ± 0.6%), Al(6.01 ± 0.17%), and Ca(5.83 ± 0.23%) in that order. Silica and yellow sand significantly decreased cell viability and increased [Ca2+]i. All three particles increased the generation of H2O2. TiO2 did not change Fenton activity, while silica induced a slight increase of Fenton activity. In contrast, yellow sand induced a significant increase of Fenton activity. Silica, yellow sand and TiO2 induced significant nitrite formations in RLE-6TN cells. Silica showed the highest increase in nitrite formation, while yellow sand induced the least formation of nitrite. Silica and yellow sand increased the release of TNF-. Based on these results, we suggest that yellow sand can induce cytotoxicity in RLE-6TN cells and reactive oxygen species, Fenton activity and reactive nitrogen species might be involved in this toxicity.

  4. Influence of silicate on the transport of bacteria in quartz sand and iron mineral-coated sand.

    Science.gov (United States)

    Dong, Zhe; Yang, Haiyan; Wu, Dan; Ni, Jinren; Kim, Hyunjung; Tong, Meiping

    2014-11-01

    The influence of silicate on the transport and deposition of bacteria (Escherichia coli) in packed porous media were examined at a constant 20 mM ionic strength with different silicate concentrations (from 0 to 1 mM) at pH 7. Transport experiments were performed in two types of representative porous media, both bare quartz sand and iron mineral-coated quartz sand. In bare quartz sand, the breakthrough plateaus in the presence of silicate in suspensions were lower and the corresponding retained profiles were higher than those without silicate ions, indicating that the presence of silicate in suspensions decreased cell transport in bare quartz sand. Moreover, the decrease of bacteria transport in quartz sand induced by silicate was more pronounced with increasing silicate concentrations from 0 to 1 mM. However, when EPS was removed from cell surfaces, the presence of silicate in cell suspensions (with different concentrations) did not affect the transport behavior of bacteria in quartz sand. The interaction of silicate with EPS on cell surfaces negatively decreased the zeta potentials of bacteria, resulting in the decreased cell transport in bare quartz sand when silicate was copresent in bacteria suspensions. In contrast, the presence of silicate in suspensions increased cell transport in iron mineral-coated sand. Silicate ions competed with bacteria for the adsorption sites on mineral-coated sand, contributing to the increased cell transport in mineral-coated sand with silicate present in cell suspensions.

  5. AEROSOL FILTRATION USING QUARTZ SAND FILTER

    Directory of Open Access Journals (Sweden)

    Abbas H. Sulaymon

    2012-01-01

    Full Text Available The cement industry is the major source of cement dust which contains heavy metals like nickel, cobalt, lead, chromium, arsenic and hazardous substances like dioxins and furans. Exposure to these substances can cause health problems to human, animals and vegetation. A continuous pilot scale quartz sand filter was constructed and uses to study the effect of important design parameters (temperature, pre-loaded dust on the collector, diameter of the filter, bed depth, collector size and superficial velocity on its performance for cleaning of cement dust from air. Initial penetration and initial pressure drop (after 180s were measured and compared for different variables used in this study. The dirty bed was cleaned by means of reverse air flow when the pressure drop across the filter rises to 20 cmH2O. A macroscopic model describes the filter clogging was used to predict the effluent histories based on initial collection efficiency (η0exp which was determined from experimental data. A removal efficiency of more than 99% was obtained. The results show that 0.4% of cement dust still adheres on the quartz sand bed after 5 min of cleaning cycle. The presence of 0.4% of pre-load dust on the quartz sand filter enhanced the efficiency and low initial penetration, moderate initial pressure drop was obtained. At given Empty Bed Contact Time (EBCT, with different filter diameters 30 and 15 cm, a sharp decrease in initial penetration from 0.41-0.03 was obtained respectively. A nonlinear relationship between penetration and temperature was found. The initial penetration can be reduced by using smaller filter diameter, small collector size and collector with pre-load dust with 0.4%. The experiment that operates at a filter diameter of 15 cm and temperature of 25°C represent the minimum penetration among all the experiments.

  6. Mars Rover Curiosity Traverses of Sand Ripples

    Science.gov (United States)

    Stein, N.; Arvidson, R. E.; Zhou, F.; Heverly, M.; Maimone, M.; Hartman, F.; Bellutta, P.; Iagnemma, K.; Senatore, C.

    2014-12-01

    Martian sand ripples present a challenge for rover mobility, with drives over ripples often characterized by high wheel sinkage and slippage that can lead to incipient embedding. Since landing in Gale Crater, Curiosity has traversed multiple sand ripples, including the transverse aeolian ridge (TAR) straddling Dingo Gap on sols 533 and 535. On sol 672, Curiosity crossed backward over a series of sand ripples before ending its drive after high motor currents initiated visual odometry (VO) processing, which detected 77% slip, well in excess of the imposed 60% slip limit. At the end of the drive, the right front wheel was deeply embedded at the base of a ripple flank with >20 cm sinkage and the rear wheels were near a ripple crest. As Curiosity continues its approach to Mount Sharp it will have to cross multiple ripples, and thus it is important to understand Curiosity's performance on sol 672 and over similar ripples. To this end the sol 672 drive was simulated in ARTEMIS (Adams-Based Rover Terramechanics Interaction Simulator), a software tool consisting of realistic rover mechanical models, a wheel-terrain interaction module for deformable and non-deformable surfaces, and realistic terrain models. ARTEMIS results, Dumont Dunes tests performed in the Mojave Desert using the Scarecrow test rover, and single wheel tests performed at MIT indicate that the high slip encountered on sol 672 likely occurred due to a combination of rover attack angle, ripple geometry, and soil properties. When ripple wavelength approaches vehicle length, the rover can reach orientations in which the leading wheels carry minimal normal loads and the trailing wheels sink deeply, resulting in high slippage and insufficient thrust to propel the rover over ripples. Even on relatively benign (i.e. low tilt) terrains, local morphology can impose high sinkage, thus impeding rover motion. Work is underway to quantify Curiosity's drive performance over various ripple geometries to retrieve soil

  7. Western Gas Sands Project status report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C.H.

    1978-09-30

    The status of government sponsored projects undertaken to increase gas production from low-permeability gas sands of the western United States during August 1978 is summarized. Background information is given in the September 1977 Status Report, NVO/0655-100. One of the largest massive Hydraulic Fracture (MHF) treatment to date was performed on Gas Producing Enterprises Well No. CIGE 2-29. C.H. Atkinson, Western Gas Sands Project (WGSP) Manager and D.C. Bleakly, CER Corporation were observers. Oriented coring operations on the Mitchell Energy well, Muse-Duke No. 1 were observed by Atkinson and Bleakly near Mexia, Texas. The Fourth Annual Department of Energy Symposium on Enhanced Oil and Gas Recovery and Improved Drilling Methods was held on August 29-31, 1978 in Tulsa, Oklahoma. The USGS continued geological and geophysical studies in the four primary study areas. Low-level oblique photography of Tertiary and Cretaceous rocks exposed in the Rock Springs Uplift area was completed, and core from the J.C. Paine well in Montana was sampled for petrograhic analysis. Bartlesville Energy Technology Center continued work on the improved pressure coring system and anticipates completion of the project by September 30, 1978. Preliminary work began on the Parametric Analysis of MHF Test Data, an Engineering Study of Western Gas Sands, by Intercomp. The National Laboratories, funded by DOE are continuing their work in the area of research and development. The emphasis is on instrumentation systems, rock mechanics, mathematical modeling, and data analysis. The Mitchell Energy well, Muse Duke No. 1, has reached total depth and was logged on August 31, 1978. The DOE well test facility was moved from the RB-MHF 3 well in Colorado to Vernal, Utah for trailer modifications and checkout.

  8. Western Gas Sands Project status report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C.H.

    1978-11-30

    Progress of government-sponsored projects directed toward increasing gas production from the low-permeability gas sands of the western United States is summarized. A Technology Implementation Plan (TIP) meeting was held at the CER office in Las Vegas, Nevada, October 16--19 to initiate the implementation phase of the Enhanced Gas Recovery (EGR) working group activities. A WGSP Logging Program meeting was conducted on October 24, 1978, at CER offices to define the problems associated with logs in tight gas sands. CER personnel and the project manager attended a two-day course on the fundamentals of core and reservoir analysis in Denver, Colorado, and met with USGS personnel to discuss USGS work on the WGSP. A meeting was held to discuss a contract for coring a Twin Arrow well on the Douglas Creek Arch, Colorado. CER Corporation personnel attended the Geological Society of America Annual Meeting held in Toronto, Canada, October 23--27 and a Gas Stimulation Workshop at Sandia Laboratories in Albuquerque, New Mexico, October 11 and 12 to discuss recent mineback experiments conducted at the Nevada Test Site. Fiscal year 1979 projects initiated by USGS and the Energy Technology Centers and National Laboratories are progressing as scheduled. Mobil Research and Development Corporation fractured zone 8 of the F-31-13G well in Rio Blanco County, Colorado. Colorado Interstate Gas Company poured the concrete pad for the compresser expected to be delivered in December and were laying pipeline between the wells at month end. The Mitchell Energy well, Muse Duke No. 1 was flowing on test at a rate of 2,100 Mcfd and preparations proceeded to fracture the well on November 15 with approximately 1,000,000 gal of fluid and 3,000,000 lb of sand. Terra Tek completed laboratory analyses of cores taken from the Mitchell Energy well.

  9. TECHNIQUES ABOUT DIRECT OPTIMIZING CONTROL OF GREEN SAND QUALITY*

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Green sand casting is still a main method in the world at present and it is very significant to develop the technology of controlling green sand quality. A new concept, from contents test to contents control, is advanced. In order to realize the new idea, a new method to on-line test active clay and moisture of green sand - double powers energizing alternately (DPEA) method is put forwards. The principle of the new method is to energize standard sand sample with AC and DC powers and to test the electric parameters, and then, to calculate active clay and moisture of green sand by using artificial neural network (ANN). Based on this new method, a direct optimizing system for controlling green sand quality is developed. Techniques about testing and controlling methods, hardware and software are discussed.

  10. Thermo-Insulating Moulding Sand for thin Walled Castings

    Directory of Open Access Journals (Sweden)

    Cholewa M.

    2014-10-01

    Full Text Available In paper the selection of the composition and determination of main properties of novel moulding sand was described. The mail goal was to create moulding sand characterized by high thermal insulating properties in relations with low specific weight. This type of moulding sand will find application in thin walled castings with complex geometry, in particular for cores of the skeleton castings. In this work the results of the compressive strength, permeability and friability was presented. It was noted that aluminosilicate microspheres are suitable as moulding sand matrix. Influence of the polyglicol addition on quality and properties of the moulding sand was described. The use of the aluminosilicate microspheres allowed to obtain the moulding sand characterized by high insulation rate, low specific weight and good mechanical properties.

  11. Optimising the composition of natural moulding sands including thermal aspects

    Directory of Open Access Journals (Sweden)

    Jerzy St. Kowalski

    2011-04-01

    Full Text Available The paper discusses the problem of the choice of the moulding sand mixture composition in terms of the sand behaviour in contact withmolten metal. Studies of high-temperature phenomena make assessment of the sand composition applicability under real operatingconditions possible, thus leading to the elimination of sand-originating casting defects. The research was conducted on selected moulding materials included in the composition of traditional moulding sand mixtures without the addition of carbon. The effect of moulding sand composition and moisture content on the linear dilatation and stress-induced allotropic changes of quartz was examined. The analysis of these phenomena was based on 3D charts and maps generated from data collected during the tests.

  12. Removal of heavy metals through adsorption using sand

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The removal of four heavy metals i.e. Pb, Cr, Cu, and Zn from their aqueous solutions, using ordinary sand as an adsorbent, was studied at 20oC. The amount of metal adsorbed to form monolayer on sand(am), obtained from Langmuir isotherm, exhibited the preference of metals for sand in the order Pb>Cr>Cu>Zn. The heavy metal-sand adsorption phenomena can be illustrated on the basis of the interaction between surface functional group of silicates (sand) and the metal ions. It is deduced that sand can be used as a low cost adsorbent for the removal of heavy metal from wastewater (containing low conc. of metals), especially in the developing countries.

  13. Numerical study on deformation and failure of reinforced sand

    Institute of Scientific and Technical Information of China (English)

    PENG Fang-le; LI Jian-zhong; Tatsuoka Fumio

    2005-01-01

    In order to investigate the deformation and failure of reinforced sand, and the reinforcing mechanism of flexible and rigid reinforcement, a set of plane strain compression tests of dense Toyoura reinforced sand with planar reinforcement of a wide range of stiffness were analysed by a nonlinear finite element method. The analysis was incorporated into an energy-based elasto-plastic constitutive model for sand to develop a stress path-independent work-hardening parameter based on the modified plastic strain energy concept. Numerical results indicate that the global stress-strain relations of sand specimens are reinforced by using relatively flexible and rigid reinforcement, and an unreinforced sand specimen can be reasonably simulated by the current finite element method. It is also found that the reinforcing mechanism and progressive failure with a development of shear bands in reinforced sand can be reasonably examined by the finite element method.

  14. 'Sharks Teeth' -- Sand Dunes in Proctor Crater

    Science.gov (United States)

    2001-01-01

    Sometimes, pictures received from Mars Global Surveyor's Mars Orbiter Camera (MOC) are 'just plain pretty.' This image, taken in early September 2000, shows a group of sand dunes at the edge of a much larger field of dark-toned dunes in Proctor Crater. Located at 47.9oS, 330.4oW, in the 170 km (106 mile) diameter crater named for 19th Century British astronomer Richard A. Proctor (1837-1888), the dunes shown here are created by winds blowing largely from the east/northeast. A plethora of smaller, brighter ripples covers the substrate between the dunes. Sunlight illuminates them from the upper left.

  15. Sphere impact and penetration into wet sand

    Science.gov (United States)

    Marston, J. O.; Vakarelski, I. U.; Thoroddsen, S. T.

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  16. Heating tar sands formations to visbreaking temperatures

    Science.gov (United States)

    Karanikas, John Michael; Colmenares, Tulio Rafael; Zhang, Etuan; Marino, Marian; Roes, Augustinus Wilhelmus Maria; Ryan, Robert Charles; Beer, Gary Lee; Dombrowski, Robert James; Jaiswal, Namit

    2009-12-22

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  17. Biogenic crust dynamics on sand dunes

    CERN Document Server

    Kinast, Shai; Yizhaq, Hezi; Ashkenazy, Yosef

    2012-01-01

    Sand dunes are often covered by vegetation and biogenic crusts. Despite their significant role in dune stabilization, biogenic crusts have rarely been considered in studies of dune dynamics. Using a simple model, we study the existence and stability ranges of different dune-cover states along gradients of rainfall and wind power. Two ranges of alternative stable states are identified: fixed crusted dunes and fixed vegetated dunes at low wind power, and fixed vegetated dunes and active dunes at high wind power. These results suggest a cross-over between two different forms of desertification.

  18. Geology of the Athabasca oil sands

    Science.gov (United States)

    Mossop, G. D.

    1980-01-01

    In-place bitumen resources in the Alberta oil sands are estimated at 1350 billion barrels. Open-pit mining and hot water extraction methods, which involve the handling of huge tonnages of earth materials, are being employed in the two commercial plants now operating. In situ recovery methods will be required to tap the 90 percent of reserves that are too deeply buried to be surface mined. Development of in situ technologies will be painstaking and expensive, and success will hinge on their compatibility with extremely complex geological conditions in the subsurface.

  19. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  20. Undrained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    In the process of understanding and developing models for geomaterials, the stress-strain behaviour is commonly studied by performing triaxial tests. In the present study, several types of static triaxial tests have been performed to gain knowledge of the undrained stress-strain behaviour...... of frictional materials during monotonic loading. The tests conducted includes undrained and constant volume tests, starting from different initial states of stress and following various stress paths. All the tests are performed on reconstituted loose to medium dense specimens of Eastern Scheldt Sand....

  1. Preliminary study of 3D printing technology in edentulous jaw custom-tray fabricating technique%3D打印无牙颌个别托盘的初步研究

    Institute of Scientific and Technical Information of China (English)

    林园园; 郑秀丽; 廖国婷; 魏天骄; 冯剑桥

    2016-01-01

    目的 探讨3D打印无牙颌个别托盘较传统方法制作的个别托盘①是否能有效减少临床椅旁操作时间;②托盘印模面处理后与藻酸盐印模材间的固位强度比较和变化.方法 ①选取全口义齿修复患者10例,上颌为A组,下颌为B组,记录3D打印法和传统方法(自凝丙烯酸树脂)制作个别托盘的椅旁工作时间;②测量3D打印托盘和传统托盘(光固化树脂和自凝丙烯酸树脂)的印模面3种情况下(以不处理、打孔和涂布托盘粘接剂)与藻酸盐印模材间的固位强度.结果 ①A、B组3D打印法分别是34.37、28.19 min,传统法分别是64.95、63.94 min,3D打印无牙颌个别托盘的时间均显著少于传统法的时间(P<0.05);②3D打印托盘表面涂粘接剂组固位强度为2.31 N/cm2,为组内最佳(析因方差分析P<0.01).结论 3D打印无牙颌个别托盘相对于传统方法可有效减少椅旁工作时间;与藻酸盐印模材间具有良好的固位强度,打孔及表面涂托盘粘接剂均可明显提高其固位强度,表面涂粘接剂效果更明显.%Objective ① To evaluate whether manufacturing edentulous jaw individual tray by 3D printing can effectively reduce the clinical chair side time compared with traditional method. ②To compare the fixation strength and changes between alginate impression and the impression surface of trays [3D printing tray(Polylactic acid/PLA), traditional tray(acrylic resin and light-cured resin)] after dealt with different ways. Methods ① Select ten models of edentulate patients, then screen maxillary(A) and mandible(B)(n=10). Record the chair side time of fabricating individual trays in 3D and traditional ways.②Handle the trays by wontfix, the tray bind-er and punching, measure the fixation strength between the impression surface of 3D printing and traditional trays in the above three conditions and the alginate impression. Results ① The chair side time of 3D printing trays were 34.37 min( A) and 28

  2. 有孔托盘和无孔托盘印模精度的比较∗%Comparison of impression accuracy between trays with holes and those without holes

    Institute of Scientific and Technical Information of China (English)

    柴梅; 王梅兰; 姜丽媛

    2015-01-01

    目的:比较无孔托盘和有孔托盘印模精确度的差异。方法:有孔托盘和无孔托盘分别用二次印模法和一次印模法印取同一主模型,放大镜下观察分析两种托盘在牙冠颈缘复制精确度上的差异。灌制模型,测量模型标志点间的距离,比较两种托盘所取印模模型线性变化。结果:在牙冠颈缘精度上比较,一次印模法无孔托盘优秀率高于有孔托盘,差异具有统计学意义( P <0.05)。在模型线性变化率上比较,两种托盘差异无统计学意义。结论无孔托盘在牙冠颈缘复制上效果优于有孔托盘。%Objective:To compare the accuracy impression between the trays with holes and those without holes. Methods: A tray without holes and a tray with holes were used to make the same master model by one-step and two-step impression methods respectively. The accuracy difference at the cervical margin of the crown was observed and analyzed through a magnifying glass. Models were made, the distance between points was measured and the linear change of the models made by these two types of trays was compared. Results:As for the accuracy at the cervical margin of the crown , the excellent rate of trays without holes is always higher than those with holes, whether the one-step impression method or the two-step impression method was used, but the difference was significant only when one-step impression method was used. As for the linear change rate, the difference between the two kinds of trays was not significant. Conclusion:The copy made at the cervical margin of the crown by Trays without holes is better than that made by trays with holes.

  3. Fungal Growth and Manganese Peroxidase Production in a Deep Tray Solid-State Bioreactor, and In Vitro Decolorization of Poly R-478 by MnP.

    Science.gov (United States)

    Zhao, Xinshan; Huang, Xianjun; Yao, Juntao; Zhou, Yue; Jia, Rong

    2015-06-01

    The growth of Irpex lacteus F17 and manganese peroxidase (MnP) production in a selfdesigned tray bioreactor, operating in solid-state conditions at a laboratory scale, were studied. The bioreactor was divided into three layers by three perforated trays. Agroindustrial residues were used both as the carrier of bound mycelia and as a nutrient medium for the growth of I. lacteus F17. The maximum biomass production in the bioreactor was detected at 60 h of fermentation, which was consistent with the CO2 releasing rate by the fungus. During the stationary phase of fungal growth, the maximum MnP activity was observed, reaching 950 U/l at 84 h. Scanning electron microscopy images clearly showed the growth situation of mycelia on the support matrix. Furthermore, the MnP produced by I. lacteus F17 in the bioreactor was isolated and purified, and the internal peptide sequences were also identified with mass spectrometry. The optimal activity of the enzyme was detected at pH 7 and 25 °C, with a long half-life time of 9 days. In addition, the MnP exhibited significant stability within a broad pH range of 4-7 and at temperature up to 55 °C. Besides this, the MnP showed the ability to decolorize the polymeric model dye Poly R-478 in vitro.

  4. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study.

    Science.gov (United States)

    Chopra, Sakshi; Gupta, Narendra Kumar; Tandan, Amrit; Dwivedi, Ravi; Gupta, Swati; Agarwal, Garima

    2016-01-01

    Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. A significant difference in the pressure produced using different impression materials was found (P materials. The presence of relief did affect the magnitude of pressure at various locations. All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  5. Preliminary Observations from the 2014 Sand Dunes Experiment

    Science.gov (United States)

    2014-10-01

    2014 Sand Dunes Experiment by Christopher W. Miller, Ching-Sang Chiu, D. Benjamin Reeder, Ying-Jang Yang, Linus Chiu, and Chi-Fang Chen...COVERED (From-To) June 2014 4. TITLE AND SUBTITLE Preliminary Observations from the 2014 Sand Dunes Experiment 5a. CONTRACT NUMBER 5b. GRANT NUMBER...position of the Department of Defense or the U.S. Government 14. ABSTRACT The Sand Dunes 2014 experiment was international US – Taiwan

  6. MC-Parameter Calibration of Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Hanson, Mats; Hjort, T.;

    The soil parameters are dependent on both confining pressure and density index. The density index of Baskarp Sand can be determined by conducting cone penetration tests with the mini-CPT cone used in the Geotechnical Engineering Laboratory at Aalborg University. The unit weight of Baskarp Sand No...... several conventional drained triaxial tests at two different density indices performed on Baskarp Sand No. 15 (Ibsen & Bødker, 1994). The used triaxial tests are listed in Table 1 and Table 2....

  7. A soil emergence trap for collections of phlebotomine sand flies

    Directory of Open Access Journals (Sweden)

    Casanova Cláudio

    2001-01-01

    Full Text Available The identification of breeding sites of sand flies is of great epidemiological interest. A soil emergence trap for investigating potential sand fly breeding sites is described. The trap was tested in two rural areas in the Mogi Guaçu River Valley where the American cutaneous leishmaniasis is an endemic disease. Seventy-three sand fly individuals of three species, Lutzomyia intermedia s. l., L. whitmani and L. pessoai, were collected on the forest floor and peridomicile.

  8. Possibilities of preparation asphalt concrete by oil sands of Kazakhstan

    OpenAIRE

    Erbol Tileuberdi; Yerdos Ongarbayev; F. Behrendt; Schneider, I.; Yerzhan Imanbayev; B. Tuleutayev; Yerlan Doszhanov; Zulkhair Mansurov

    2012-01-01

    In the paper physicochemical properties of oil sands of Munayli-Mola deposits and efficient ways to use them for preparing asphalt concrete were represented. For determination of organic part of oil sands the extraction methods were used in Soxhlet apparatus by variety of solvents. It has been established 16 wt.% content of natural bitumen in oil sands, which compared with results of ash content determination. According to results of experiment, the natural bitumen is heavy oil and its charac...

  9. Microwave processing of oil sands and contribution of clay minerals

    OpenAIRE

    John P. Robinson; Binner, Eleanor; Saeid, Abdul; Al-Harahsheh, Mohammad; Kingman, S. W.

    2014-01-01

    This study establishes the feasibility of microwave heating for extracting oil from Oil Sands in ex-situ processes. Previous studies in this area have shown some potential, but have not characterised the dielectric properties of the Oil Sands used, nor related them to the mineral composition, both of which are vital if successful scale up is to be achieved. In this work the fundamental interactions of microwave energy with Oil Sands are investigated and understood for the first time, and the ...

  10. Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub

    OpenAIRE

    Xuejun Yang; Baskin, Carol C.; Baskin, Jerry M.; Guangzheng Liu; Zhenying Huang

    2012-01-01

    The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand buria...

  11. Provenance of coastal dune sands along Red Sea, Egypt

    Indian Academy of Sciences (India)

    Samir M Zaid

    2017-06-01

    Texture, mineralogy, and major and trace element geochemistry of 26 coastal dune sand samples were studied to determine the provenance and tectonic environment of two dune fields close to the beaches of Safaga (SF) and Quseir (QS) at the Egyptian Red Sea coast. Onshore winds generate fine, moderate, moderately-well to well-sorted, coarse-skewed to near-symmetrical dune sands with mesokurtic distributions. Winds pick up and transport grains from nearby beach sands and alluvial deposits into a wide Red Sea coastal plain at the border of the beach. The mineralogical (Qt–Ft–Lt) and geochemical composition of the sands, indicate that SF and QS coastal dune sands are mature and influenced by quartz-rich sands. The average CIA values in SF and QS coastal dune sands are low relative to the range of the PAAS, suggesting an arid climate and a low intensity of chemical weathering. The SF and QS coastal dune sand samples are plotted in the recycled orogen and partly in craton interior fields suggesting recycled older sedimentary and partly metamorphic-plutonic sources. The high content of quartz with shell debris and carbonates in coastal dune sands support the recycled sedimentary beach and alluvial sand sources. The dominance of heavy minerals like amphiboles (hornblende) and biotite in the coastal dune sands also supports the effect of metamorphic-plutonic source rocks. The new tectonic discriminant-function diagrams suggest that the coastal dune sands were deposited in a passive margin of a synrift basin. The results provide a good evidence for the extension in the Red Sea rift system during Oligocene-post Pliocene, which is consistent with the general geology of Egypt.

  12. Developing a Sand Management Plan for Galveston Island

    Science.gov (United States)

    2015-10-16

    US Army Corps of Engineers BUILDING STRONG® Developing a Sand Management Plan for Galveston Island Ashley E. Frey, P. E. Research Civil...GenCade Alternatives • Sand Management Alternatives and Plan • Beach Nourishment Project 2 Innovative solutions for a safer, better world...BUILDING STRONG® Problem Statement/Approach Recommend a long-term plan of actions to better manage sands on Galveston Island Initial Tasks

  13. EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF FLUORIDE IN SAND

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-mei; SU Bao-yu

    2006-01-01

    The transport and transformation of fluoride in sand were studied by using soil tank test under the condition of saturated water in this article. Based on the analysis of the laboratory experiments, the rules of fluorine transportation and transformation were simulated in sand by solving the advection-diffusion equation. Through comparison between computed results and observed data , it is shown that the established model and determined parameters could be used to simulate the fluoride transport in sand.

  14. Oil sands to the rescue: oil sand microbial communities can degrade recalcitrant alkyl phenyl alkanoic acids

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, Corinne [University of Essex (Canada)], email: cwhitby@essex.ac.uk

    2011-07-01

    Almost half of all global oil reserves are found as biodegraded heavy oils found in vast tar sand deposits located in North and South America and these account for 47% of Canadian oil production. Oil sand extraction generates large amounts of toxic waste water, known as oil sand process waters (OSPW), that are stored in large tailing ponds that contain toxic compounds like naphthenic acids (NAs). The presence of NAs creates problems like toxicity, corrosion, and the formation of calcium napthenate deposits which block pipelines and other infrastructure and need to be removed. This paper presents oil sand microbial communities that can degrade these NAs. The approach is to apply new aliphatic and aromatic NAs as substrates to supplement and identify NA degrading microbes and also to identify the metabolites produced and explain NA degradation pathways and the functional genes involved. The chemistry and the processes involved are explained. From the results, it is suggested that pure cultures of P. putida KT2440 be used against NAs.

  15. Modeling the response of shoreface-connected sand ridges to sand extraction on an inner shelf

    NARCIS (Netherlands)

    Nnafie, A.; de Swart, Huib; Calvete, D.; Garnier, R.

    2014-01-01

    Shoreface-connected sand ridges are rhythmic bedforms that occur on many storm-dominated inner shelves. The ridges span several kilometers, are a few meters high, and they evolve on a timescale of centuries. A processbased model is used to gain a fundamental insight into the response of these ridges

  16. Modeling the response of shoreface-connected sand ridges to sand extraction on an inner shelf

    NARCIS (Netherlands)

    Nnafie, A.; de Swart, Huib; Calvete, D.; Garnier, R.

    2014-01-01

    Shoreface-connected sand ridges are rhythmic bedforms that occur on many storm-dominated inner shelves. The ridges span several kilometers, are a few meters high, and they evolve on a timescale of centuries. A processbased model is used to gain a fundamental insight into the response of these ridges

  17. Chemical Stablilisation of Sand : Part VIII Furan Resins as Dune and Coastal Sand Stabiliser

    Directory of Open Access Journals (Sweden)

    Ram Gopal

    1990-04-01

    Full Text Available Studies on furan resin as dune sand stabiliser are presented. Influence of acid catalysts, viz. phenol disulphonic acid, sulphuric acid, hydrochloric acid and phosphoric acid and other catalysts, viz. trichlorotoluene and benzoyl chloride along with promoters, zinc chloride and ferric chloride, on the strength of stabilised furan resin-sand specimens has been discussed. Optimisation studies on resin content, catalysts and promoters and curing conditions have revealed that maximum strength of 260 kg/cm/sup 2/ of the standard specimens made by compaction of coastal sand using furan resins (10 per cent, sulphuric acid (9N, 30 per cent and a curing time of 2 hr at 40 degree Centigrade is higher than the 170 kg/cm/sup 2/ of specimens made of Rajasthan desert sand. Sandy patches stabilised by seepage technique recorded a maximum strength of 125 kg/cm/sup 2/. Physico-chemical characteristics of this system and effect of environment on stabilised specimens have also been studied and field trials conducted successfully. This resin-catalyst system would be extremely useful in humid and saline field (coastal areas for different military applications.

  18. Produção de bulbinhos de cebola em bandejas de isopor Production of onion bulb sets in styrofoam trays

    Directory of Open Access Journals (Sweden)

    Antonio Ismael Inácio Cardoso

    1999-10-01

    Full Text Available Com o objetivo de estudar a viabilidade de produção de bulbinhos de cebola sob ambiente protegido em diferentes tipos de bandejas de poliestireno expandido foram instalados dois experimentos. No primeiro, trabalhando com a cultivar Serrana, foram avaliadas três tipos de bandejas com diferentes números de plantas por célula: uma planta/célula na bandeja de 288 células, três a cinco plantas/célula na de 128 e cinco a nove plantas/célula na de 72 células. No outro experimento, testaram-se nove cultivares, semeadas somente em bandejas de 128 células com três plantas por célula. Utilizou-se o delineamento em blocos ao acaso com quatro repetições no primeiro ensaio e cinco no segundo, sendo cada parcela constituída por uma bandeja. Observou-se que quanto maior a densidade de plantio menor o tamanho do bulbinho (diâmetro e peso. O manejo adequado de adubações em cobertura pode viabilizar, tecnicamente, a produção de cinco bulbinhos com 1,3 cm de diâmetro (2 g por célula, na bandeja de 128 células. Quanto ao ensaio de cultivares, ‘Crioula’ da Agroflora, ‘Crioula’ da Granja Lotário e ‘Houston’ apresentaram 83%, 67% e 81% de plantas bulbificadas, enquanto que nas demais (‘Aurora’, ‘Baia Periforme’, ‘Brownsville’, ‘Petroline’, ‘Pira Ouro’, ‘Pirana’ e ‘Serrana’ obteve-se 100% de bulbificação. As principais vantagens na produção de bulbinhos em bandeja foram: uniformidade, ausência de plantas daninhas e de patógenos. É um sistema que pode ser útil aos viveiristas que tem entressafra de mudas nos meses de agosto a novembro, período de produção dos bulbinhos. Poderá, também, ser uma alternativa na produção de bulbinhos para conserva, no controle de qualidade de lotes de sementes e em programas de melhoramento de cebola.One objective was to study the production of onion Allium cepa L.. bulb sets in a protected environment in a seedling system with trays with different number of

  19. Severe sand aspiration: a case report with complete recovery.

    Science.gov (United States)

    Glinjongol, Chanin; Kiatchaipipat, Surachai; Thepcharoenniran, Somchai

    2004-07-01

    A 5-year-old boy, previously healthy, was admitted to Ratchaburi Hospital after being buried in a sand pile. He presented with dyspnea and tachypnea. Chest radiograph showed opaque particles in both main and segmental bronchi (sand bronchogram). The first attempt of bronchoscopy was unsatisfactory as a considerable amount of sand particles had migrated further into the distal bronchi. A second bronchoscopy was performed with 0.9% saline lavage. Most of the sand particles were successfully removed. Intravenous steroids and antibiotics were administered for treatment. The patient was discharged uneventfully by the end of the first week of hospitalization.

  20. Olivine sand from Kawashiri Beach in Kagoshima, Japan

    OpenAIRE

    MATSUI, Tomoaki; マツイ, トモアキ; 松井, 智彰

    2001-01-01

    The olivine sand from Kawashiri Beach was studied by chemical and X-ray analyses. At least six groups of olivine are mixed in the olivine sand in this region, and they are classified according to the composition of the silicate-melt inclusions in them. The composition of the olivine sand ranges from Fo_70 to Fo_75, and the sum of the Mn_2SiO_4 and Ca_2SiO_4 content is less than 1 (mol %). These crystal chemical data for the olivine sand not only provide basic mineralogical info...

  1. [Influence of perlite sand on the skin in experiment].

    Science.gov (United States)

    Dracheva, E E; Iatsyna, I V; Lapina, N E; Ianin, V A; Antoshina, L I; Zhadan, I Iu; Krasavina, E K

    2012-01-01

    In the present work influence of perlite sand has been studied on a skin of Sprague-Dawley male rat (300-350 g). The biopsy of intact rat skin has been used as control. Contact of the perlite sand with animals' skin causes the reaction of an inflammation amplifying with increase of duration of the influence of substance. Therefore, despite an inert chemical compound, long contact with perlite sand in conditions of production can promote development of skin diseases. From the result of this investigation it is concluded that perlite sand causes irritating action on the skin and it is necessary to apply additional protective means to workers contacting to this substance.

  2. Numerical modeling of wind-blown sand on Mars.

    Science.gov (United States)

    Huang, HaoJie; Bo, TianLi; Zheng, XiaoJing

    2014-09-01

    Recent observation results show that sand ripples and dunes are movable like those on Earth under current Martian climate. And the aeolian process on Mars therefore is re-attracting the eyes of scientific researchers in different fields. In this paper, the spatial and temporal evolution of wind-blown sand on Mars is simulated by the large-eddy simulation method. The simulations are conducted under the conditions of both friction wind speed higher and lower than the "fluid threshold", respectively. The fluid entrainment of the sand particles, the processes among saltation sand particles and sand bed, and the negative feedback of sand movement to flow field are considered. Our results show that the "overshoot" phenomenon also exists in the evolution of wind-blown sand on Mars both temporally and spatially; impact entrainment affects the sand transport rate on Mars when the wind speed is smaller or larger than the fluid threshold; and both the average saltation length and height are one order of magnitudes larger than those on Earth. Eventually, the formulas describing the sand transport rate, average saltation length and height on Mars are given, respectively.

  3. Sand control mechanism analysis of metallic wool screen

    Energy Technology Data Exchange (ETDEWEB)

    Yongquan, H.; Jinzhou, Z.; Zhinjun, W.; Zhaofeng, L. [Southwest Petroleum Institute, China, (China); Lei, Y. [Liaohe petroleum Administration, China, (China)

    1997-08-01

    A filter prepacked with metallic wool was developed and claimed to have been effectively used on thermal and unconsolidated sand oil wells. Structural features of the filter screen and the factors having a bearing on its sand control function, such as particle characteristics, fluid properties, environmental conditions, and the filtering characteristics of metallic wool, were discussed. Some experimental results have been provided to illustrate desirable characteristics and advantages. According to this evidence, sanding velocity is highest at the beginning, stabilizing gradually. Production pressure drop must be appropriately adjusted to achieve best results with well sanding control. 9 refs., 1 tab., 5 figs.

  4. Trajectories of saltating sand particles behind a porous fence

    Science.gov (United States)

    Zhang, Ning; Lee, Sang Joon; Chen, Ting-Guo

    2015-01-01

    Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a 'no-fence' case. A wind fence (ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles.

  5. Effective Laboratory Method of Chromite Content Estimation in Reclaimed Sands

    Directory of Open Access Journals (Sweden)

    Ignaszak Z.

    2016-09-01

    Full Text Available The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid. It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium. The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.

  6. Geologic and paleoecologic studies of the Nebraska Sand Hills

    Science.gov (United States)

    Ahlbrandt, Thomas S.; Fryberger, S.G.; Hanley, John H.; Bradbury, J. Platt

    1980-01-01

    PART A: The Nebraska Sand Hills are an inactive, late Quaternary, most probably Holocene, dune field (covering 57,000 km 2 ) that have been eroded along streams and in blowouts, resulting in excellent lateral and vertical exposures of the stratification of dune and interdune sediments. This paper presents new data on the geometry, primary sedimentary structures, modification of sedimentary structures, direction of sand movement, and petrography of these eolian deposits. Eolian deposits of the Sand Hills occur as relatively thin (9-24 m) 'blanket' sands, composed of a complex of dune and discontinuous, diachronous interdune deposits unconformably overlying fluviolacustrine sediments. The internal stratification of large dunes in the Sand Hills (as high as 100 m), is similar to the internal stratification of smaller dunes of the same type in the Sand Hills, differing only in scale. Studies of laminae orientation in the Sand Hills indicate that transverse, barchan, and blowout dunes can be differentiated in rocks of eolian origin using both the mean dip angle of laminae and the mean angular deviation of dip direction. A variety of secondary structures modify or replace primary eolian stratification in the Sand Hills, the more common of which are dissipation structures and bioturbation. Dissipation structures in the Sand Hills may develop when infiltrating water deposits clay adjacent to less permeable layers in the sand, or along the upper margins of frozen layers that form in the sands during winter. Cross-bed measurements from dunes of the Nebraska Sand Hills necessitate a new interpretation of the past sand transport directions. The data from these measurements indicate a general northwest-to-southeast drift of sand, with a more southerly drift in the southeast part of the Sand Hills. A large area of small dunes Sand Hills was interpreted by him on the basis of morphology only. We interpret these as transverse-ridge dunes that were generally moving to the south

  7. Falling sand tests on various coatings

    Energy Technology Data Exchange (ETDEWEB)

    Manetti, M.; Zonfrillo, G.; Pratesi, F. [Florence Univ. (Italy). Dipt. di Meccanica e Tecnologie Industriali; Giovannetti, I. [GE Oil and Gas - Nuovo Pilnone, Florence (Italy)

    2010-07-01

    Abrasive wear is responsible for severe machine parts and in particular of compressor impellers. Methods of increasing service lifetime are based on employment of abrasion resistant materials or more frequently of the creation of hard, wear-resistant surface layers. In this work a bare aluminium alloy and the same alloy with four different coatings have been tested at room temperature, in order to verify their resistance to falling abrasive. Following standard ASTM D968-93, tests have been performed using a precise quantity of sand as abrasive and letting it fall on the sample with a standard apparatus: two different kinds of sand have been used, in order to obtain also information on the influence of composition and Grain size of the abrasive on material resistance. Determinations of hardness, roughness, weight loss, and morphology of the eroded surface have also been carried out. The comparison between the coatings in vestilated has been performed on the basis of the thickness decrease of the samples. (orig.)

  8. Sulfur biogeochemistry of oil sands composite tailings

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

    2011-07-01

    This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

  9. TESTING OF TMR SAND MANTIS FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Krementz, D; William Daugherty, W

    2007-06-12

    Screening tests of Sand Mantis candidate materials selected for erosion resistance have been completed. The results of this testing identified that over a relatively short period of operation (<1 hour), measurable erosion will occur in each of the candidate zoom tube materials given equal operating exposure. Additionally, this testing has shown that erosion of the rubber discharge hose directly downstream of the vehicle could be expected to limit the service life of the discharge hose. On the basis of these test results, SRNL recommends the following; {lg_bullet} redesign of critical system components (e.g., zoom tube, discharge hose) should be conducted to improve system characteristics relative to erosion and capitalize on the results of this testing, {lg_bullet} continued efforts to deploy the Sand Mantis should include testing to better define and optimize operating parameters, and gain an understanding of system dynamics, {lg_bullet} discontinue wear testing with the selected materials pending redesign of critical system components (1st recommendation) and inclusion of other candidate materials. The final selection of additional candidate materials should be made following design changes, but might include a Stellite alloy or zirconia.

  10. Microstructural characterization of a Canadian oil sand

    CERN Document Server

    Dinh, Hong Doan; Nauroy, Jean-François; Tang, Anh-Minh; Souhail, Youssef; 10.1139/T2012-072

    2013-01-01

    The microstructure of oil sand samples extracted at a depth of 75 m from the estuarine Middle McMurray formation (Alberta, Canada) has been investigated by using high resolution 3D X-Ray microtomography ($\\mu$CT) and Cryo Scanning Electron Microscopy (CryoSEM). $\\mu$CT images evidenced some dense areas composed of highly angular grains surrounded by fluids that are separated by larger pores full of gas. 3D Image analysis provided in dense areas porosity values compatible with in-situ log data and macroscopic laboratory determinations, showing that they are representative of intact states. $\\mu$CT hence provided some information on the morphology of the cracks and disturbance created by gas expansion. The CryoSEM technique, in which the sample is freeze fractured within the SEM chamber prior to observation, provided pictures in which the (frozen) bitumen clearly appears between the sand grains. No evidence of the existence of a thin connate water layer between grains and the bitumen, frequently mentioned in th...

  11. Western Gas Sands Project: status report

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-01

    Progress of the major government sponsored projects undertaken to increase gas production from low permeability gas sands of the western United States during March 1978 is summarized. The Bartlesville Energy Research Center (BERC) and participating National Laboratories, funded by DOE, are continuing their work in the area of research and development. The emphasis is on the development of new tools and instrumentation systems, rock mechanics, mathematical modeling and data analysis. Field Tests and demonstrations active in the Uinta and Piceance Basins include: Gas Producing Enterprises (GPE) Natural Buttes Unit Wells No. 9, 14, 18, 19, 20, 21 and 22, Mobil Research and Development Corporation, Well No. F-31-13G, and Rio Blanco Natural Gas Company, Well No. 498-4-1. Gas Producing Enterprises Natural Buttes Unit Well No. 9 was fractured on March 27, 1978. The treatment consisted of 554,000 pounds of sand and 349,000 gallons of gel. Mitchell Energy Corporation of Houston, Texas was awarded Department of Energy Contract EF-78-C-08-1547 on March 15, 1978. Field work under this contract is scheduled to begin on June 15, 1978, with the drilling of a new well.

  12. Adaptation to life in aeolian sand: how the sandfish lizard, Scincus scincus, prevents sand particles from entering its lungs

    OpenAIRE

    Stadler, Anna T.; Vihar, Boštjan; Günther, Mathias; Huemer, Michaela; Riedl, Martin; Shamiyeh, Stephanie; Mayrhofer, Bernhard; Böhme, Wolfgang; Baumgartner, Werner

    2016-01-01

    ABSTRACT The sandfish lizard, Scincus scincus (Squamata: Scincidae), spends nearly its whole life in aeolian sand and only comes to the surface for foraging, defecating and mating. It is not yet understood how the animal can respire without sand particles entering its respiratory organs when buried under thick layers of sand. In this work, we integrated biological studies, computational calculations and physical experiments to understand this phenomenon. We present a 3D model of the upper res...

  13. Comparison of buried sand ridges and regressive sand ridges on the outer shelf of the East China Sea

    Science.gov (United States)

    Wu, Ziyin; Jin, Xianglong; Zhou, Jieqiong; Zhao, Dineng; Shang, Jihong; Li, Shoujun; Cao, Zhenyi; Liang, Yuyang

    2016-07-01

    Based on multi-beam echo soundings and high-resolution single-channel seismic profiles, linear sand ridges in U14 and U2 on the East China Sea (ECS) shelf are identified and compared in detail. Linear sand ridges in U14 are buried sand ridges, which are 90 m below the seafloor. It is presumed that these buried sand ridges belong to the transgressive systems tract (TST) formed 320-200 ka ago and that their top interface is the maximal flooding surface (MFS). Linear sand ridges in U2 are regressive sand ridges. It is presumed that these buried sand ridges belong to the TST of the last glacial maximum (LGM) and that their top interface is the MFS of the LGM. Four sub-stage sand ridges of U2 are discerned from the high-resolution single-channel seismic profile and four strikes of regressive sand ridges are distinguished from the submarine topographic map based on the multi-beam echo soundings. These multi-stage and multi-strike linear sand ridges are the response of, and evidence for, the evolution of submarine topography with respect to sea-level fluctuations since the LGM. Although the difference in the age of formation between U14 and U2 is 200 ka and their sequences are 90 m apart, the general strikes of the sand ridges are similar. This indicates that the basic configuration of tidal waves on the ECS shelf has been stable for the last 200 ka. A basic evolutionary model of the strata of the ECS shelf is proposed, in which sea-level change is the controlling factor. During the sea-level change of about 100 ka, five to six strata are developed and the sand ridges develop in the TST. A similar story of the evolution of paleo-topography on the ECS shelf has been repeated during the last 300 ka.

  14. Comparison of buried sand ridges and regressive sand ridges on the outer shelf of the East China Sea

    Science.gov (United States)

    Wu, Ziyin; Jin, Xianglong; Zhou, Jieqiong; Zhao, Dineng; Shang, Jihong; Li, Shoujun; Cao, Zhenyi; Liang, Yuyang

    2017-06-01

    Based on multi-beam echo soundings and high-resolution single-channel seismic profiles, linear sand ridges in U14 and U2 on the East China Sea (ECS) shelf are identified and compared in detail. Linear sand ridges in U14 are buried sand ridges, which are 90 m below the seafloor. It is presumed that these buried sand ridges belong to the transgressive systems tract (TST) formed 320-200 ka ago and that their top interface is the maximal flooding surface (MFS). Linear sand ridges in U2 are regressive sand ridges. It is presumed that these buried sand ridges belong to the TST of the last glacial maximum (LGM) and that their top interface is the MFS of the LGM. Four sub-stage sand ridges of U2 are discerned from the high-resolution single-channel seismic profile and four strikes of regressive sand ridges are distinguished from the submarine topographic map based on the multi-beam echo soundings. These multi-stage and multi-strike linear sand ridges are the response of, and evidence for, the evolution of submarine topography with respect to sea-level fluctuations since the LGM. Although the difference in the age of formation between U14 and U2 is 200 ka and their sequences are 90 m apart, the general strikes of the sand ridges are similar. This indicates that the basic configuration of tidal waves on the ECS shelf has been stable for the last 200 ka. A basic evolutionary model of the strata of the ECS shelf is proposed, in which sea-level change is the controlling factor. During the sea-level change of about 100 ka, five to six strata are developed and the sand ridges develop in the TST. A similar story of the evolution of paleo-topography on the ECS shelf has been repeated during the last 300 ka.

  15. Distribution of sand dunes and sand shifts along the southern fringe of the Mu Us Desert since the Ming Dynasty

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This article takes the two segments of the Ming Great Walls, Dabian and Erbian, and their associated barracks and forts as geographical references. Based on a detailed scrutiny of historical records of the Ming and Qing dynasties, and on field surveys, the southern boundaries of the sand dunes and sand shifts of the Mu Us Desert in the Ming and Qing dynasties are carefully reconstructed. A comparison of the southern boundaries of the sand dunes and sand shifts of the Mu Us Desert in Ming and Qing with the modern boundary revealed in remote sensing imagery clearly shows that the southern boundary of dunes and shifts in the Mu us Desert has expanded only in a few areas and on a small scale. In the area to the south of Changle Fort, along the direction of annually prevailing winds, sand drifts have penetrated through the Jialu River valley into the loess region and have formed a sand strip of 32 km long and 3 km wide. To the east of Qingping Fort, sand drifts penetrated toward the eastern loess region through the Luhe River valley and have formed another sand strip of 8 km long and 2 km wide. Generally speaking, though the intensity of human activity has been increasing in this area since the Ming Dynasty, the Mu Us Desert has not significantly expanded toward the southeast or southwest. The sand-loess boundary in the southern fringe of the Mu Us Desert has been almost unchanged since the Ming Dynasty.

  16. Faecal indicator bacteria enumeration in beach sand: A comparison study of extraction methods in medium to coarse sands

    Science.gov (United States)

    Boehm, A.B.; Griffith, J.; McGee, C.; Edge, T.A.; Solo-Gabriele, H. M.; Whitman, R.; Cao, Y.; Getrich, M.; Jay, J.A.; Ferguson, D.; Goodwin, K.D.; Lee, C.M.; Madison, M.; Weisberg, S.B.

    2009-01-01

    Aims: The absence of standardized methods for quantifying faecal indicator bacteria (FIB) in sand hinders comparison of results across studies. The purpose of the study was to compare methods for extraction of faecal bacteria from sands and recommend a standardized extraction technique. Methods and Results: Twenty-two methods of extracting enterococci and Escherichia coli from sand were evaluated, including multiple permutations of hand shaking, mechanical shaking, blending, sonication, number of rinses, settling time, eluant-to-sand ratio, eluant composition, prefiltration and type of decantation. Tests were performed on sands from California, Florida and Lake Michigan. Most extraction parameters did not significantly affect bacterial enumeration. anova revealed significant effects of eluant composition and blending; with both sodium metaphosphate buffer and blending producing reduced counts. Conclusions: The simplest extraction method that produced the highest FIB recoveries consisted of 2 min of hand shaking in phosphate-buffered saline or deionized water, a 30-s settling time, one-rinse step and a 10 : 1 eluant volume to sand weight ratio. This result was consistent across the sand compositions tested in this study but could vary for other sand types. Significance and Impact of the Study: Method standardization will improve the understanding of how sands affect surface water quality. ?? 2009 The Society for Applied Microbiology.

  17. Properties of Desert Sand and CMAS Glass

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2014-01-01

    As-received desert sand from a Middle East country has been characterized for its phase composition and thermal stability. X-ray diffraction analysis showed the presence of quartz (SiO2), calcite (CaCO3), gypsum (CaSO4.2H2O), and NaAlSi3O8 phases in as-received desert sand and showed weight loss of approx. 35 percent due to decomposition of CaCO3 and CaSO4.2H2O when heated to 1400 C. A batch of as-received desert sand was melted into calcium magnesium aluminosilicate (CMAS) glass at approx. 1500 C. From inductively coupled plasma-atomic emission spectrometry, chemical composition of the CMAS glass was analyzed to be 27.8CaO-4MgO-5Al2O3-61.6SiO2-0.6Fe2O3-1K2O (mole percent). Various physical, thermal and mechanical properties of the glass have been evaluated. Bulk density of CMAS glass was 2.69 g/cc, Young's modulus 92 GPa, Shear modulus 36 GPa, Poisson's ratio 0.28, dilatometric glass transition temperature (T (sub g)) 706 C, softening point (T (sub d)) 764 C, Vickers microhardness 6.3 +/- 0.4 GPa, indentation fracture toughness 0.75 +/- 0.15 MPa.m (sup 1/2), and coefficient of thermal expansion (CTE) 9.8 x 10 (exp -6)/degC in the temperature range 25 to 700 C. Temperature dependence of viscosity has also been estimated from various reference points of the CMAS glass using the Vogel-Fulcher-Tamman (VFT) equation. The glass remained amorphous after heat treating at 850 C for 10 hr but crystallized into CaSiO3 and Ca-Mg-Al silicate phases at 900 C or higher temperatures. Crystallization kinetics of the CMAS glass has also been investigated by differential thermal analysis (DTA). Activation energies for the crystallization of two different phases in the glass were calculated to be 403 and 483 kJ/mol, respectively.

  18. Compensation Grouting in Sand: Experiments, Field Experiences and Mechanisms

    NARCIS (Netherlands)

    Bezuijen, A.

    2010-01-01

    This thesis reports on experimental research on compensation grouting in sand. It is investigated in model tests, how the shape of the grout bodies made during injection depends on the grout properties, the density of the sand and the way the tubes are installed. The shape of the grout body affects

  19. Test Setup for Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina

    The test setup for testing axially static and cyclic loaded piles in sand is described in the following. The purpose for the tests is to examine the tensile capacity of axially loaded piles in dense fully saturated sand. The pile dimensions are chosen to resemble full scale dimension of piles used...... in offshore pile foundations today....

  20. Efficient modelling of sand wave behaviour [Powerpoint Presentation

    NARCIS (Netherlands)

    Berg, van den Joris; Damme, van Ruud

    2004-01-01

    Sand waves form a pattern of more or less parallel ridges. The wave length is about 300 meters and the height up to 10 meters, which is a considerable amount of the total water depth. Sand waves migrate with speeds of about 10 meters per year. Information on their behaviour is valuable: the larger p

  1. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.

    2007-01-01

    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  2. OPTIMIZATION OF GRANULOMETRIC COMPOSITION OF DRY FRIABLE SAND BLENDS

    Directory of Open Access Journals (Sweden)

    V. S. Doroshenko

    2014-01-01

    Full Text Available A method for optimizing the composition of the grain loose sand mixtures by placing the binder particles into the pores of the frame sand compaction of these mixtures. An example of calculation of grain composition of such a mixture.

  3. Sand transport in oscillatory sheet-flow; a literature review

    NARCIS (Netherlands)

    Janssen, C.M.

    1995-01-01

    This literature review is part of the ongoing research on sand transport in oscillatory sheet-flow, as taking place at the coast during storms. Because sheet-flow corresponds to conditions of high shear stress, large amounts of sand are transported. Therefore it is an important part of the total san

  4. The extraction of bitumen from western tar sands. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  5. The extraction of bitumen from western tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  6. The stable stiffness triangle - drained sand during deformation cycles

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2017-01-01

    Cyclic, drained sand stiffness was observed using the Danish triaxial appa- ratus. New, deformation dependant soil property (the stable stiffness triangle) was detected. Using the the stable stiffness triangle, secant stiffness of drained sand was plausible to predict (and control) even during ir...

  7. Modeling sheet-flow sand transport under progressive surface waves

    NARCIS (Netherlands)

    Kranenburg, W.M.

    2013-01-01

    In the near-shore zone, energetic sea waves generate sheet-flow sand transport. In present day coastal models, wave-induced sheet-flow sand transport rates are usually predicted with semi-empirical transport formulas, based on extensive research on this phenomenon in oscillatory flow tunnels. Howeve

  8. Stress Wave Propagation in Unsaturated Sands. Volume 1. Centrifuge Modeling

    Science.gov (United States)

    1993-04-01

    122 xii LIST OF TABLES 2.1 Soil properties from explosive testing in sand by Drake and Little (1983...Ottawa, Illinois (ASTM C190). A summary of the physical properties of both Tyndall and Ottawa sands is given in Tablas 3.3a and 3.3b. Grain size

  9. Pathogen removal using saturated sand colums supplemented with hydrochar

    NARCIS (Netherlands)

    Chung, J.W.

    2015-01-01

    This PhD study has evaluated hydrochars derived from biowastes as adsorbents for pathogen removal in water treatment. Pathogen removal experiments were conducted by carrying out breakthrough analysis using a simple sand filtration set-up. Glass columns packed by 10 cm sand bed supplemented with mino

  10. Sand transport processes in the surf and swash zones

    NARCIS (Netherlands)

    Zanden, van der Joep

    2016-01-01

    Long-term predictions of beach morphology using numerical models contribute to cost-effective coastal protection strategies. The physics of sand transport in the wave breaking region and the swash zone are not fully understood, leading to poor predictive capability of existing sand transport models

  11. Acetylcholinesterase mutations and organophosphate resistance in sand flies and mosquitoes

    Science.gov (United States)

    The sand fly, Phlebotomus papatasi (Scopoli) is a major vector of Leishamnia major, the principle causative agent of human cutaneous leishmaniasis in the Middle East, southern Europe, northern Africa, and Southern Asia. Sand fly bites and leishmaniasis significantly impacted U.S. military operations...

  12. Providing floating capabilities in latest-generation sand screens

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, E.G.; Coronado, M.P. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Baker Hughes, Houston, TX (United States)

    2008-10-15

    Alternative production methods are needed for the massive reserves located in the bitumen region of Canada's tar sands. The area has over 100 installations of sand screens/slotted liners in both injection and production legs using steam-assisted gravity drainage (SAGD) technology. Multiple wells must be drilled from a single pad because of the sensitive nature of the environment. With significant depths of these wells, a floating sand screen provides assurance that the sand screen will reach the desired depth. Paraffin is generally used to plug the flow access of the screen during installation. This paper discussed a new technology that has been developed to allow for sand screen installations without relying on paraffin wax to withstand differential pressure. The new technology uses a hydro-mechanical valving system incorporated into the screen design to temporarily close off the screen while being run in the hole. The paper described how the technology could provide a reliable, time-saving solution for SAGD installations when floating sand control screens are needed. The paper discussed current technology and its limitations, sand screen installation, screen design for floating applications, and additional applications. It was concluded that this technology solution provides a unique alternative to the methods currently used to install sand screens with SAGD technology in the fast growing Canadian market for bitumen recovery. 2 refs., 5 figs.

  13. Fine sand in motion: the influence of interstitial air

    NARCIS (Netherlands)

    Homan, T.A.M.

    2013-01-01

    Sand is a granular material, and therefore it consists of individual grains arranged in a packing. The pores in-between the grains are usually filled with a fluid, in this case air. Now, is this interstitial air able to influence the behavior of the sand bed as a whole? When a ball impacts on fine,

  14. Crater formation during raindrop impact on sand

    Science.gov (United States)

    de Jong, Rianne; Zhao, Song-Chuan; van der Meer, Devaraj

    2017-04-01

    After a raindrop impacts on a granular bed, a crater is formed as both drop and target deform. After an initial, transient, phase in which the maximum crater depth is reached, the crater broadens outwards until a final steady shape is attained. By varying the impact velocity of the drop and the packing density of the bed, we find that avalanches of grains are important in the second phase and hence affect the final crater shape. In a previous paper, we introduced an estimate of the impact energy going solely into sand deformation and here we show that both the transient and final crater diameter collapse with this quantity for various packing densities. The aspect ratio of the transient crater is however altered by changes in the packing fraction.

  15. Direct Production of Silicones From Sand

    Energy Technology Data Exchange (ETDEWEB)

    Larry N. Lewis; F.J. Schattenmann: J.P. Lemmon

    2001-09-30

    Silicon, in the form of silica and silicates, is the second most abundant element in the earth's crust. However the synthesis of silicones (scheme 1) and almost all organosilicon chemistry is only accessible through elemental silicon. Silicon dioxide (sand or quartz) is converted to chemical-grade elemental silicon in an energy intensive reduction process, a result of the exceptional thermodynamic stability of silica. Then, the silicon is reacted with methyl chloride to give a mixture of methylchlorosilanes catalyzed by cooper containing a variety of tract metals such as tin, zinc etc. The so-called direct process was first discovered at GE in 1940. The methylchlorosilanes are distilled to purify and separate the major reaction components, the most important of which is dimethyldichlorosilane. Polymerization of dimethyldichlorosilane by controlled hydrolysis results in the formation of silicone polymers. Worldwide, the silicones industry produces about 1.3 billion pounds of the basic silicon polymer, polydimethylsiloxane.

  16. Effects of oil sands sediments on fish

    Energy Technology Data Exchange (ETDEWEB)

    Parrott, J.; Colavecchia, M.; Hewitt, L.; Sherry, J.; Headley, J. [Environment Canada, Ottawa, ON (Canada); Turcotte, D.; Liber, K. [Saskatchewan Univ., Regina, SK (Canada)

    2010-07-01

    This paper described a collaborative project organized by Natural Resources Canada (NRCan) Panel of Energy Research and Development (PERD) with researchers from Environment Canada and the University of Saskatchewan. The 4-year study was conducted to assess the toxicity of oil sands sediments and river waters, and reclamation ponds and sediments on laboratory-raised fish. Three sediments from rivers were evaluated for their potential to cause adverse impacts on fathead minnow eggs and larvae for a period of 18 days. The study monitored hatching, larval survival, development, and growth. Naphthenic acids (NA), polycyclic aromatic hydrocarbons (PAHs) and metals were measured in the sediments to determine if the compounds can be correlated with observed toxicity. The study will also assess walleye eggs exposed to sediments, and in situ fish exposures. Toxicity identification and evaluation (TIE) studies will be conducted to isolate the fractions that may affect fish development and growth.

  17. Transport velocities of coal and sand particles

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J. (Inst. de Carboquimica, Zaragoza (Spain)); Diego, L.F. de (Inst. de Carboquimica, Zaragoza (Spain)); Gayan, P. (Inst. de Carboquimica, Zaragoza (Spain))

    1993-10-01

    Transport velocities of narrow cut sizes of coarse particles of sand and coal were determined at room temperature and atmospheric pressure. These velocities were obtained by four different methods previously utilized by other authors with fine particles. The four methods tested gave good predictions of the transport velocities. The method based on the measurement of the time required for all the solids to leave the bed without feeding in any fresh solid is specially interesting because of its rapidity and simplicity. The determined transport velocities were strongly dependent on the solid particle size and density. The experimental values were fitted to an equation which fitted both the experimental results obtained in this work and other published results obtained with fine particles. (orig.)

  18. The state of oil sands wetland reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Foote, L. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    The state of oil sand and wetlands reclamation was the subject of this presentation. Wildlife habitat and response, plant community and production, and microbial biology were examples of research areas surrounding this body of knowledge. Hydrological research and landscape ecology were discussed along with peatlands and marshes such as the Corvette and the Kia. A few examples of what has been learned in the area of wetlands reclamation was presented. Other topics were also discussed, such as timeframes, pragmatic policy approaches, reclamation costs, research needs and some ideas on maturing the field. It was concluded that environmental conditions change with time and area because of time, chemistry, physics, stoichiometry, as well as biotic mediation and facilitation. figs.

  19. SAND: Automated VLBI imaging and analyzing pipeline

    Science.gov (United States)

    Zhang, Ming

    2016-05-01

    The Search And Non-Destroy (SAND) is a VLBI data reduction pipeline composed of a set of Python programs based on the AIPS interface provided by ObitTalk. It is designed for the massive data reduction of multi-epoch VLBI monitoring research. It can automatically investigate calibrated visibility data, search all the radio emissions above a given noise floor and do the model fitting either on the CLEANed image or directly on the uv data. It then digests the model-fitting results, intelligently identifies the multi-epoch jet component correspondence, and recognizes the linear or non-linear proper motion patterns. The outputs including CLEANed image catalogue with polarization maps, animation cube, proper motion fitting and core light curves. For uncalibrated data, a user can easily add inline modules to do the calibration and self-calibration in a batch for a specific array.

  20. Thermal aspects of temperature transformations in silica sand

    Directory of Open Access Journals (Sweden)

    J.St. Kowalski

    2010-07-01

    Full Text Available Problems related with the choice of moulding sand composition considering its behaviour in contact with molten metal were discussed.The investigations of high-temperature phenomena enable moulding sand composition to be evaluated in terms of its applicability underthe specific conditions of a foundry shop. It is also possible to eliminate the casting defects related to moulding sand and its properties. The investigations were carried out on selected moulding sands from the family of the traditional carbon-free moulding mixtures. The effect of moulding sand composition and moisture content on the linear dilatation and stress formation caused by an allotropic quartz transformation was determined. The investigated phenomena were analysed on 3D diagrams plotted from the test data. A strong effect of the beta quartz - alpha quartz transformation at a temperature of about 6000C was stated.

  1. Properties of sodium silicate bonded sand hardened by microwave heating

    Institute of Scientific and Technical Information of China (English)

    Wang Jina; Fan Zitian; Zan Xiaolei; Pan Di

    2009-01-01

    The sodium silicate bonded sand hardened by microwave heating has many advantages,such as low sodium silicate adding quantity,fast hardening speed,high room temperature strength,good collapsibility and certain surface stability. However,it has big moisture absorbability in the air,which would lead to the compression strength and the surface stability of the sand molds being sharply reduced. In this study,the moisture absorbability of the sodium silicate bonded sand hardened by microwave heating in different humidity conditions and the effect factors were investigated. Meanwhile,the reasons for the big moisture absorbability of the sand were analyzed.Some measures to overcome the problems of high moisture absorbability,bad surface stability and sharply reducing strength in the air were discussed. The results of this study establish the foundation of green and clean foundry technology based on the microwave heating hardening sodium silicate sand process.

  2. A New Type of Exposed Oil Sand Mine

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With several means of analysis, the unique organic compound component and distribution of exposed oil sand existing in Qinghai, north-west China, is revealed. Qinghhai oil sand has great content of light components with high saturated hydrocarbon content up to approximately 50%, while its heavy components of colloid and asphaltene is rather low (<38%); straight-chain alkane has a regular distribution concentrating mainly around C28; it has a very high atom ratio of H/C. The physical parameters of the oil sand mine are within the range of common heavy oils. Such chemical composition and distribution obviously differs from that of other known exposed oil sand mines. This particular property of the oil sand is formed due to the unique geographical and geological environment. Therefore, it is intended to exploit the mine with a new combined method, i.e., first drill horizontal wells and then opencut.

  3. Optimization of Blended Mortars Using Steel Slag Sand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of mortar made of ground granulated blast-furnace slag (GGBFS), gypsum,clinker and steel slag sand (<4.75 mm) was developed. The ratio of steel slag sand to GGBFS was 1:1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development.Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined.The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.

  4. Sedimentation process of saturated sand under impact loading

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Junfeng; MENG; Xiangyue

    2005-01-01

    The initial small inhomogeneity of saturated sand could be amplified during the sedimentation process after liquefaction, and cracks could be observed in the sand column. Layers of fine sand could also be found at the exact place where cracks developed and disappeared. The phenomena and the whole process were experimentally shown by X-rays images. To account for the phenomena, a linearized stability analysis of the sedimentation of saturated sand was conducted; however, it did not produce a satisfactory result. A three-phase flow model describing the transportation of fine sand is presented in this paper. It is shown that such a kind of erosion/deposition model was qualitatively in good agreement with the experimental observation.

  5. Compressive Strength of Compacted Clay-Sand Mixes

    Directory of Open Access Journals (Sweden)

    Faseel Suleman Khan

    2014-01-01

    Full Text Available The use of sand to improve the strength of natural clays provides a viable alternative for civil infrastructure construction involving earthwork. The main objective of this note was to investigate the compressive strength of compacted clay-sand mixes. A natural clay of high plasticity was mixed with 20% and 40% sand (SP and their compaction and strength properties were determined. Results indicated that the investigated materials exhibited a brittle behaviour on the dry side of optimum and a ductile behaviour on the wet side of optimum. For each material, the compressive strength increased with an increase in density following a power law function. Conversely, the compressive strength increased with decreasing water content of the material following a similar function. Finally, the compressive strength decreased with an increase in sand content because of increased material heterogeneity and loss of sand grains from the sides during shearing.

  6. The effects of psammophilous plants on sand dune dynamics

    CERN Document Server

    Bel, Golan

    2013-01-01

    Psammophilous plants are special plants that flourish in sand moving environments. There are two main mechanisms by which the wind affects these plants: (i) sand drift exposes roots and covers branches--the exposed roots turn into new plants and the covered branches turn into new roots; both mechanisms result in an enhanced growth rate of the psammophilous plant cover of the dunes; (ii) strong winds, often associated with sand movement, tear branches and seed them in nearby locations, resulting in new plants and an enhanced growth rate of the psammophilous plant cover of the dunes. Despite their important role in dune dynamics, to our knowledge, psammophilous plants have never been incorporated into mathematical models of sand dunes. Here, we attempt to model the effects of these plants on sand dune dynamics. We construct a set of three ordinary differential equations for the fractions of surface cover of regular vegetation, biogenic soil crust and psammophilous plants. The latter reach their optimal growth u...

  7. Traceability of optical length measurements on sand surfaces

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    This work concerns traceable measurements on moulds used in automatic casting lines made of green sand, which has a very low strength against the force of a contact probe. A metrological set-up was made based on the use of calibrated workpieces following ISO 15530-3 to determine the uncertainty...... of optical measurements on a sand surface. A new customised sand sample was developed using a hard binder to withstand the contact force of a touch probe, while keeping optical cooperativeness similar to that of green sand. The length of the sample was calibrated using a dial gauge set-up. An optical 3D...... scanner with fringe pattern projection was used to measure the length of a green sand sample (soft sample) with traceability transfer through the hard sample. Results confirm that the uncertainty of the optical scanner on the substituted hard sample is similar to that of the soft sample, so the hard...

  8. Recycling of petroleum-contaminated sand.

    Science.gov (United States)

    Taha, R; Ba-Omar, M; Pillay, A E; Roos, G; al-Hamdi, A

    2001-08-01

    The environmental impact of using petroleum-contaminated sand (PCS) as a substitute in asphalt paving mixtures was examined. An appreciable component of PCS is oily sludge, which is found as the dregs in oil storage tanks and is also produced as a result of oil spills on clean sand. The current method for the disposal of oily sludge is land farming. However, this method has not been successful as an oil content of tests and environmental studies were conducted to establish the integrity of the materials containing the recycled sludge. These included physical and chemical characterization of the sludge itself, and an assessment of the mechanical properties of materials containing 0%, 5%, 22% and 50% oily sludge. The blended mixtures were subjected to special tests, such as Marshall testing and the determination of stability and flow properties. The experimental results indicated that mixtures containing up to 22% oily sludge could meet the necessary criteria for a specific asphalt concrete wearing course or bituminous base course. To maximize the assay from the recycled material, the environmental assessment was restricted to the 50% oily sludge mixture. Leachates associated with this particular mixture were assayed for total organic residue and certain hazardous metal contaminants. The results revealed that the organics were negligible, and the concentrations of the metals were not significant. Thus, no adverse environmental impact should be anticipated from the use of the recycled product. Our research showed that the disposal of oily sludge in asphalt paving mixtures could possibly yield considerable savings per tonne of asphalt concrete, and concurrently minimize any direct impact on the environment.

  9. Climatology of yellow sand (Asian sand, Asian dust or Kosa)in East Asia

    Institute of Scientific and Technical Information of China (English)

    Masatoshi; Yoshino

    2002-01-01

    In order to study climatology of yellow sand (Asian sand, Asian dust or Kosa) in EastAsia, secular fluctuation in China, Korea and Japan in the recent 30 years was presented. Thenumber of days with sand-dust storm at five stations in China-Hotan, Zhangye, Minqin, Jurhand Beijing, decreases a lot at the former three stations, but changed little at the latter two stations.Suggesting that the recent global warming is more evident in Xinjiang and Gansu, where the fre-quency of cold air invasions from the higher latitudes is decreasing. But, the eastern parts ofMongolia, inner Mongolia, and North China encounter stronger cyclones in early spring as a resultof global warming. These cyclones bring cold air from higher latitudes, causing severe duststorms. Secular variation in the annual days with sand-dust storms in China and Kosa days in Ko-rea and Japan show a parallel change with higher frequency from 1975 to 1985. This may be re-lated to the higher frequency of La Nina years. However, different tendency was shown in theperiod from 1986 to 1996. Since 1996 or 1997, a sharp increase is clear, which may be caused bythe developed cyclones in East Asia as well as human activities, and stronger land degradationunder La Nina conditions. Anomalies of the total number of stations with Kosa days were dis-cussed in accordance with some synoptic meteorological conditions such as the differences be-tween Siberian anticyclone and Aleutian cyclone center at 500 hPa level during the previous winter.

  10. Broadband Scattering from Sand and Sand/Mud Sediments with Extensive Environmental Characterization

    Science.gov (United States)

    2017-01-30

    frequency sound speed and attenuation measurements in sandy sediments with a portable velocimeter.” (4) Proceedings from the 2nd International...Bay, FL off the shore of Shell Island. The sediment consisted of the 15 cm mud layer overlying a muddy, coarse sand basement. Scattering data was...Demoulin, X., L. Guillon, and B.T. Hefner (2017), “High-frequency sound speed and attenuation measurements in sandy sediments with a portable

  11. Aeolian sand transport and aeolian deposits on Venus: A review

    Science.gov (United States)

    Kreslavsly, Mikhail A.; Bondarenko, Nataliya V.

    2017-06-01

    We review the current state of knowledge about aeolian sand transport and aeolian bedforms on planet Venus. This knowledge is limited by lack of observational data. Among the four planetary bodies of the Solar System with sufficient atmospheres in contact with solid surfaces, Venus has the densest atmosphere; the conditions there are transitional between those for terrestrial subaerial and subaqueous transport. The dense atmosphere causes low saltation threshold and short characteristic saltation length, and short scale length of the incipient dunes. A few lines of evidence indicate that the typical wind speeds exceed the saltation threshold; therefore, sand transport would be pervasive, if sand capable of saltation is available. Sand production on Venus is probably much slower than on the Earth; the major terrestrial sand sinks are also absent, however, lithification of sand through sintering is expected to be effective under Venus' conditions. Active transport is not detectable with the data available. Aeolian bedforms (transverse dunes) resolved in the currently available radar images occupy a tiny area on the planet; however, indirect observations suggest that small-scale unresolved aeolian bedforms are ubiquitous. Aeolian transport is probably limited by sand lithification causing shortage of saltation-capable material. Large impact events likely cause regional short-term spikes in aeolian transport by supplying a large amount of sand-size particles, as well as disintegration and activation of older indurated sand deposits. The data available are insufficient to understand whether the global aeolian sand transport occurs or not. More robust knowledge about aeolian transport on Venus is essential for future scientific exploration of the planet, in particular, for implementation and interpretation of geochemical studies of surface materials. High-resolution orbital radar imaging with local to regional coverage and desirable interferometric capabilities is the

  12. Microbes in Beach Sands: Integrating Environment, Ecology and Public Health.

    Science.gov (United States)

    Whitman, Richard; Harwood, Valerie J; Edge, Thomas A; Nevers, Meredith; Byappanahalli, Muruleedhara; Vijayavel, Kannappan; Brandão, João; Sadowsky, Michael J; Alm, Elizabeth Wheeler; Crowe, Allan; Ferguson, Donna; Ge, Zhongfu; Halliday, Elizabeth; Kinzelman, Julie; Kleinheinz, Greg; Przybyla-Kelly, Kasia; Staley, Christopher; Staley, Zachery; Solo-Gabriele, Helena M

    2014-09-01

    Beach sand is a habitat that supports many microbes, including viruses, bacteria, fungi and protozoa (micropsammon). The apparently inhospitable conditions of beach sand environments belie the thriving communities found there. Physical factors, such as water availability and protection from insolation; biological factors, such as competition, predation, and biofilm formation; and nutrient availability all contribute to the characteristics of the micropsammon. Sand microbial communities include autochthonous species/phylotypes indigenous to the environment. Allochthonous microbes, including fecal indicator bacteria (FIB) and waterborne pathogens, are deposited via waves, runoff, air, or animals. The fate of these microbes ranges from death, to transient persistence and/or replication, to establishment of thriving populations (naturalization) and integration in the autochthonous community. Transport of the micropsammon within the habitat occurs both horizontally across the beach, and vertically from the sand surface and ground water table, as well as at various scales including interstitial flow within sand pores, sediment transport for particle-associated microbes, and the large-scale processes of wave action and terrestrial runoff. The concept of beach sand as a microbial habitat and reservoir of FIB and pathogens has begun to influence our thinking about human health effects associated with sand exposure and recreational water use. A variety of pathogens have been reported from beach sands, and recent epidemiology studies have found some evidence of health risks associated with sand exposure. Persistent or replicating populations of FIB and enteric pathogens have consequences for watershed/beach management strategies and regulatory standards for safe beaches. This review summarizes our understanding of the community structure, ecology, fate, transport, and public health implications of microbes in beach sand. It concludes with recommendations for future work in

  13. A simple morphodynamic model for sand banks and large-scale sand pits subject to asymetrical tides

    NARCIS (Netherlands)

    Roos, P.C.; Hulscher, S.J.M.H.; Peters, B.G.T.M.; Nemeth, A.A.; Ikeda, S.

    2001-01-01

    We extend existing knowledge on theoretical growth characteristics of tidal sand banks by including asymmetrical tides with an M0, M2 and M4-constituent, thus allowing for migration. Furthermore, in the context of the continuously increasing demand on the Dutch sand market, we show that creating a l

  14. Oblique second-order sand transport pathways on an intertidal sand flat in a natural tidal inlet system

    DEFF Research Database (Denmark)

    Ernstsen, Verner Brandbyge; Lefebvre, Alice; Kroon, Aart

    2013-01-01

    . This indicates distinct second-order sand transport pathways oblique to the main tidal transport pathways. A conceptual model for the development of the bedforms and channels is presented, which comprises hypotheses of the hydrodynamic forcing of the different second-order sand transport pathways. During flood...

  15. Experimental analysis of sand particles' lift-off and incident velocities in wind-blown sand flux

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Zhibao Dong; Xiaojing Zheng

    2005-01-01

    The probability distributions of sand particles' lift-off and incident velocities in a wind-blown sand flux play very important roles in the simulation of the wind-blown sand movement. In this paper, the vertical and the horizontal speeds of sand particles located at 1.0 mm above a sand-bed in a wind-blown sand flux are observed with the aid of Phase Doppler Anemometry (PDA) in a wind tunnel. Based on the experimental data, the probability distributions of not only the vertical lift-off speed but also the lift-off velocity as well as its horizontal component and the incident velocity as well as its vertical and horizontal components can be obtained by the equal distance histogram method. It is found, according to the results of the χ2-test for these probability distributions, that the probability density functions (pdf's) of the sand particles' lift-off and incident velocities as well as their vertical components are described by the Gamma density function with different peak values and shapes and the downwind incident and lift-off horizontal speeds, respectively, can be described by the lognormal and the Gamma density functions. These pdf's depend on not only the sand particle diameter but also the wind speed.

  16. Comparison of two Satellite Imaging Platforms for Evaluating Sand Dune Migration in the Ubari Sand Sea (Libyan Fazzan)

    Science.gov (United States)

    Els, A.; Merlo, S.; Knight, J.

    2015-04-01

    Sand dunes can change location, form or dimensions depending on wind direction and strength. Sand dune movements can be effectively monitored through the comparison of multi-temporal satellite images. However, not all remote sensing platforms are suitable to study sand dunes. This study compares coarse (Landsat) and fine (Worldview) resolution platforms, specifically focussing on sand dunes within the Ubari Sand Sea (Libya). Sand dune features (crest line, dune ridge basal outlines) were extracted from Landsat and Worldview 2 imagery in order to construct geomorphic maps. These geomorphic maps were then compared using image overlay and differencing, and the Root Mean Squared Error (RMSE) was used to determine if the mapped dune patterns were significantly different. It was found that Landsat is a sufficient data source when studying dune patterns within a regional sand sea, but smaller dunes identified from Worldview data were not capable of being extracted in the data sourced from Landsat. This means that for studies concerned with the dune patterns and movements within sand seas, Landsat is sufficient. But in studies where the specific dynamics of specific dunes are required, a finer resolution is required; platforms such as Worldview are needed in order to gain more detailed insight and to link the past and present day climate and environmental change.

  17. Simulation and Analysis on the Two-Phase Flow Fields in a Rotating-Stream-Tray Absorber by Using Computational Fluid Dynamics

    Institute of Scientific and Technical Information of China (English)

    邵雄飞; 吴忠标

    2004-01-01

    The flow field of gas and liquid in a φ150mm rotating-stream-tray (RST) scrubber is simulated by using computational fluid dynamic (CFD) method. The simulation is based on the two-equation RNG κ-ε turbulence model, Eulerian multiphase model, mad a real-shape 3D model with a huge number of meshes. The simulation results include detailed information about velocity, pressure, volume fraction and so on. Some features of the flow field are obtained: liquid is atomized in a thin annular zone; a high velocity air zone prevents water drops at the bottom from flying towards the wall;the pressure varies sharply at the end of blades and so on. The results will be helpful for structure optimization and engineering design.

  18. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sakshi Chopra

    2016-01-01

    Full Text Available Introduction: Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. Materials and Methods: The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. Results: A significant difference in the pressure produced using different impression materials was found (P < 0.001. Light body vinyl polysiloxane produced significantly lesser pressure than zinc oxide eugenol impression materials. The presence of relief did affect the magnitude of pressure at various locations. Conclusion: All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Clinical Implication: Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  19. Interaction Between Graphene Oxide Nanoparticles and Quartz Sand.

    Science.gov (United States)

    Sotirelis, Nikolaos P; Chrysikopoulos, Constantinos V

    2015-11-17

    In this study, the influence of pH, ionic strength (IS), and temperature on graphene oxide (GO) nanoparticles attachment onto quartz sand were investigated. Batch experiments were conducted at three controlled temperatures (4, 12, and 25 °C) in solutions with different pH values (pH 4, 7, and 10), and ionic strengths (IS = 1.4, 6.4, and 21.4 mM), under static and dynamic conditions. The surface properties of GO nanoparticles and quartz sand were evaluated by electrophoretic mobility measurements. Derjaguin-Landau-Verwey-Overbeek (DLVO) potential energy profiles were constructed for the experimental conditions, using measured zeta potentials. The experimental results showed that GO nanoparticles were very stable under the experimental conditions. Both temperature and pH did not play a significant role in the attachment of GO nanoparticles onto quartz sand. In contrast, IS was shown to influence attachment. The attachment of GO particles onto quartz sand increased significantly with increasing IS. The experimental data were fitted nicely with a Freundlich isotherm, and the attachment kinetics were satisfactorily described with a pseudo-second-order model, which implies that the quartz sand exhibited substantial surface heterogeneity and that GO retention was governed by chemisorption. Furthermore, thermodynamic analysis revealed that the attachment process was nonspontaneous and endothermic, which may be associated with structural changes of the sand surfaces due to chemisorption. Therefore, secondary minimum interaction may not be the dominant mechanism for GO attachment onto the quartz sand under the experimental conditions.

  20. Fresh groundwater resources in a large sand replenishment

    Science.gov (United States)

    Huizer, Sebastian; Oude Essink, Gualbert H. P.; Bierkens, Marc F. P.

    2016-08-01

    The anticipation of sea-level rise and increases in extreme weather conditions has led to the initiation of an innovative coastal management project called the Sand Engine. In this pilot project a large volume of sand (21.5 million m3) - also called sand replenishment or nourishment - was placed on the Dutch coast. The intention is that the sand is redistributed by wind, current, and tide, reinforcing local coastal defence structures and leading to a unique, dynamic environment. In this study we investigated the potential effect of the long-term morphological evolution of the large sand replenishment and climate change on fresh groundwater resources. The potential effects on the local groundwater system were quantified with a calibrated three-dimensional (3-D) groundwater model, in which both variable-density groundwater flow and salt transport were simulated. Model simulations showed that the long-term morphological evolution of the Sand Engine results in a substantial growth of fresh groundwater resources, in all adopted climate change scenarios. Thus, the application of a local sand replenishment could provide coastal areas the opportunity to combine coastal protection with an increase of the local fresh groundwater availability.