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Sample records for mab 5h11-cca sandwich

  1. Sandwich Panels

    Directory of Open Access Journals (Sweden)

    N. Ramachandran

    1963-05-01

    Full Text Available This introductory article give an insight into the different methods employed in the construction of Sandwich panels, their limitations and future design application for defence use as a structural element with one of the highest strength-weight ratios yet devised.

  2. Sandwich construction

    Science.gov (United States)

    Marshall, A.

    A form of composites known as structural sandwich construction is presented in terms of materials used, design details for solving edging and attachment problems, and charts of design material analysis. Sandwich construction is used in nearly all commercial airliners and helicopters, and military air and space vehicles, and it is shown that this method can stiffen a structure without causing a weight increase. The facing material can be made of 2024 or 7075 aluminum alloy, titanium, or stainless steel, and the core material can be wood or foam. The properties of paper honeycomb and various aluminum alloy honeycombs are presented. Factors pertaining to adhesive materials are discussed, including products given off during cure, bonding pressure, and adaptability. Design requirements and manufacturing specifications are resolved using numerous suggestions.

  3. Sandwich DIY

    Institute of Scientific and Technical Information of China (English)

    肖蕾

    2006-01-01

    我们都知道sandwich是一种方便食品,就是在两片面包中加上一些肉和蔬菜。Sandwich这个名字来源于英国的一位桑威治伯爵(Earl of Sandwich)。据说这位伯爵嗜赌如命,就是到吃饭的时候也不愿停下来。于是他就叫侍者把肉、蛋、菜夹在面包片中,让他拿在手上边赌边吃。后来人们就把这种夹馅面包叫做sandwich。现在sandwich已成为风靡世界的快餐食品(snack)了。Sandwich的做法其实很简单。如果你有两片面包,你几乎可以在这两片面包之间夹上任何食物来给自己做一个三明治。下面就让我们试一试,做一个三明治来吃。第一步:在一片面包上抹上黄油(butter)或植物黄油,在另一片面包上抹上蛋黄酱(mayonnaise)和芥末酱(mustard)。喜欢吃番茄酱(catsup)也可以放番茄酱!第二步:把花生酱(peanut butter)或者乳酪片(cream)、熟肉片放在涂了黄油的面包片上。想吃什么肉就放什么肉,香肠也可以!第三步:在乳酪上面放酸黄瓜片、番茄片和生菜。也可以根据个人的口味再放些乳酪、芥末酱和(或)番茄酱、洋葱、辣椒、盐、黑胡椒和醋。第四步:将第二片面包盖在上面,就做成了一个sand...

  4. A sandwich ELISA to detect VHSV and IPNV in turbot

    OpenAIRE

    Vázquez-Brañas, M. (Manuel); Coll-Morales, J. (Julio); Estepa, A

    1994-01-01

    Abstract: The recent demonstration that reared turbot (Scophthalmus maximus L) is a natural host for salmonid rhabdoviruses has made their rapid detection relevant to these fish species. A unique protocol to select and use non-competitive monoclonal antibodies (Mabs) for two high-sensitivity sandwich ELISAs has been developed to detect both infectious pancreatic necrosis virus (IPNV) and viral haemorrhagic septicaemia virus (VHSV) in turbot kidney extracts to assess the possibility of using t...

  5. The sandwich sign

    Directory of Open Access Journals (Sweden)

    Nasreen Mahomed

    2012-09-01

    Full Text Available The sandwich sign refers to the sandwiching of mesenteric vessels and fat by enlarged mesenteric nodes on cross-sectional imaging, commonly occurring in lymphoma, but not specific to lymphoma. The sign is radiologically indistinguishable from post-transplant lymphoproliferative disorders. The radiological significance of the sandwich sign is in suggesting the diagnosis of lymphoma so that appropriate treatment may be initiated early as the tumour has a rapid growth pattern.

  6. Analysis list: mab-5 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available mab-5 Embryo,Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/mab-5.1.tsv http:...//dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/mab-5.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/ce10/target/mab-5.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/mab-5.Embryo.tsv,http:...//dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/mab-5.Larvae.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/ce10/colo/Embryo.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Larvae.gml ...

  7. Sandwich classification theorem

    Directory of Open Access Journals (Sweden)

    Alexey Stepanov

    2015-09-01

    Full Text Available The present note arises from the author's talk at the conference ``Ischia Group Theory 2014''. For subgroups FleN of a group G denote by Lat(F,N the set of all subgroups of N , containing F . Let D be a subgroup of G . In this note we study the lattice LL=Lat(D,G and the lattice LL ′ of subgroups of G , normalized by D . We say that LL satisfies sandwich classification theorem if LL splits into a disjoint union of sandwiches Lat(F,N G (F over all subgroups F such that the normal closure of D in F coincides with F . Here N G (F denotes the normalizer of F in G . A similar notion of sandwich classification is introduced for the lattice LL ′ . If D is perfect, i.,e. coincides with its commutator subgroup, then it turns out that sandwich classification theorem for LL and LL ′ are equivalent. We also show how to find basic subroup F of sandwiches for LL ′ and review sandwich classification theorems in algebraic groups over rings.

  8. Development of monoclonal antibody-based sandwich ELISA for detection of dextran.

    Science.gov (United States)

    Wang, Sheng-Yu; Li, Zhe; Wang, Xian-Jiang; Lv, Sha; Yang, Yun; Zeng, Lian-Qiang; Luo, Fang-Hong; Yan, Jiang-Hua; Liang, Da-Feng

    2014-10-01

    Dextran as anti-nutritional factor is usually a result of bacteria activity and has associated serial problems during the process stream in the sugar industry and in medical therapy. A sensitive method is expected to detect dextran quantitatively. Here we generated four monoclonal antibodies (MAbs) against dextran using dextran T40 conjugated with bovine serum albumin (BSA) as immunogen in our lab following hybridoma protocol. Through pairwise, an MAb named D24 was determined to be conjugated with horseradish peroxidase (HRP) and was used in the establishment of a sensitive sandwich enzyme-linked immunosorbent assay (ELISA) method for determination of dextran, in which MAb D9 was chosen as a capture antibody. The detection limit and working scope of the developed sandwich ELISA method were 3.9 ng/mL and 7.8-500 ng/mL with a correlation coefficient of 0.9909. In addition, the cross-reaction assay demonstrated that the method possessed high specificity with no significant cross-reaction with dextran-related substances, and the recovery rate ranged from 96.35 to 102.00%, with coefficient of variation ranging from 1.58 to 6.94%. These results indicated that we developed a detection system of MAb-based sandwich ELISA to measure dextran and this system should be a potential tool to determine dextran levels.

  9. A Method to the mAbNESS?

    OpenAIRE

    McCAIN, JACK

    2004-01-01

    It’s the hottest area of biotech drug development, with more than 100 currently in development. If mAbs make life easier for patients with devastating diseases, demand will skyrocket. Payers want want proof of their value.

  10. The UC Davis/NIH NeuroMab Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the UC Davis/NIH NeuroMab facility is to generate and distribute high quality, validated mouse monoclonal antibodies against molecular targets found...

  11. Predicting safe sandwich production

    DEFF Research Database (Denmark)

    Birk, Tina; Duan, Zhi; Møller, Cleide Oliveira de Almeida

    2014-01-01

    and serving. However, Danish sandwich producing companies find it challenging to comply with this and have expressed a need for more flexibility. The Danish guidelines do allow for a prolongation of the acceptable time outside the cold chain, if the safety of the specific production can be documented....... There is, therefore, room for developing targeted tools for evaluating the time-temperature scenarios in sandwich production. This study describes a decision support tool developed to offer the producers more flexibility. Based on time/temperature measurements obtained during preparation combined......Time and temperature control is crucial to avoid growth of pathogens during production and serving of cold ready-to-eat meals. The Danish guidelines state that chilled foods, such as sandwiches, should not be outside the cold chain for more than 3 hours including the time for preparation...

  12. On Sandwiched Singularities

    OpenAIRE

    Möhring, Konrad

    2004-01-01

    Sandwich-Singularitäten sind die Singularitäten auf derNormalisierung von Aufblasungen eines regulärenFlächenkeimes. In der Arbeit wird ein enger Zusammenhangzwischen Topologie und Deformationstheorie vonSandwich-Singularitäten einerseits und ebenenKurvensingularitäten andererseits dargestellt. NeueErgebnisse betreffen u.a. Deformationen vonnulldimensionalen komplexen Räumen in der Ebene, die durchvollständige Ideale beschrieben werden, z.B. wann'simultanes Aufblasen' der Fasern einer solchen...

  13. Origin of Sandwich

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    In every language there are words that have some interesting stories behind them. The word “sandwich” forexample, is very common in English. If we want to know the story behind it, we must know something about an English nobleman named Sandwich who lived in the 18th century.

  14. Making a Sandwich

    Institute of Scientific and Technical Information of China (English)

    郭富强

    2011-01-01

    Do you like eating sandwiches? Here is a recipe(做法) for a fruit sandwich.First , you should put butter(黄油)on two slices(片) of bread. Next, peel(剥开) three bananas. Now cut up(切碎) these three bananas and apple.

  15. Development of monoclonal antibodies (MAbs) to feline interferon (fIFN)-γ as tools to evaluate cellular immune responses to feline infectious peritonitis virus (FIPV).

    Science.gov (United States)

    Satoh, Ryoichi; Kaku, Ayumi; Satomura, Megumi; Kohori, Michiyo; Noura, Kanako; Furukawa, Tomoko; Kotake, Masako; Takano, Tomomi; Hohdatsu, Tsutomu

    2011-06-01

    Feline infectious peritonitis virus (FIPV) can cause a lethal disease in cats, feline infectious peritonitis (FIP). The antibody-dependent enhancement (ADE) of FIPV infection has been recognised in experimentally infected cats, and cellular immunity is considered to play an important role in preventing the onset of FIP. To evaluate the importance of cellular immunity for FIPV infection, monoclonal antibodies (MAbs) against feline interferon (fIFN)-γ were first created to establish fIFN-γ detection systems using the MAbs. Six anti-fIFN-γ MAbs were created. Then, the difference in epitope which those MAbs recognise was demonstrated by competitive enzyme-linked immunosorbent assay (ELISA) and IFN-γ neutralisation tests. Detection systems for fIFN-γ (sandwich ELISA, ELISpot assay, and two-colour flow cytometry) were established using anti-fIFN-γ MAbs that recognise different epitopes. In all tests, fIFN-γ production from peripheral blood mononuclear cells (PBMCs) obtained from cats experimentally infected with an FIPV isolate that did not develop the disease was significantly increased by heat-inactivated FIPV stimulation in comparison with medium alone. Especially, CD8(+)fIFN-γ(+) cells, but not CD4(+)fIFN-γ(+) cells, were increased. In contrast, fIFN-γ production from PBMCs isolated from cats that had developed FIP and specific pathogen-free (SPF) cats was not increased by heat-inactivated FIPV stimulation. These results suggest that cellular immunity plays an important role in preventing the development of FIP. Measurement of fIFN-γ production with the anti-fIFN-γ MAbs created in this study appeared to be useful in evaluating cellular immunity in cats.

  16. Quantification of human tissue transglutaminase by a luminescence sandwich enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Wolf, Johannes; Lachmann, Ingolf; Wagner, Uta; Osman, Awad A; Mothes, Thomas

    2011-12-15

    Tissue transglutaminase (tTG) is a calcium-dependent enzyme that catalyzes crosslinking of peptidic glutamine residues with primary amines via isopeptide bonds and hydrolysis of ATP or GTP. The enzyme exerts a variety of functions at the cellular and tissue levels that may be disturbed in disease. Its role in pathoprocesses is poorly understood. For investigation of the involvement of tTG in disease, sensitive and specific assays should be available. We have developed the first sandwich enzyme-linked immunosorbent assay (ELISA) based on two monoclonal antibodies (mabs) against human tTG. tTG is captured by mab 3C10 and detected by biotinylated mab 10F3. After incubation with peroxidase-conjugated streptavidin, bound tTG is visualized by peroxidase reaction applying a luminescence substrate. The detection limit was 40 pg/ml. The assay was highly reproducible. Recovery of spiked tTG in crude samples was greater than 92%. The enzyme could be detected in cellular lysates and tissue homogenates of humans. The effect of typical effectors (retinoic acid and interferon-γ) on tTG expression could be demonstrated. A low signal was also obtained in mice samples, suggesting cross-reactivity of the mabs with murine tTG. The new sandwich ELISA may be successfully applied for investigation of physiological functions of tTG and of disorders associated with inadequate tTG expression.

  17. Development of a double-monoclonal antibody sandwich ELISA: Tool for chicken interferon-γ detection ex vivo

    Science.gov (United States)

    Dai, Hua; Xu, Zheng-zhong; Wang, Meiling; Chen, Jun-hua; Chen, Xiang; Pan, Zhi-ming; Jiao, Xin-an

    2016-01-01

    The aim of the present work was to develop reagents to set up a chicken interferon-γ (ChIFN-γ) assay. Four monoclonal antibodies (mAbs) specific for ChIFN-γ were generated to establish sandwich ELISA based on 2 different mAbs. To improve the detection sensitivity of ChIFN-γ, a double-monoclonal antibody sandwich ELISA was developed using mAb 3E5 as capture antibody and biotinylated mAb 3E3 as a detection reagent. The results revealed that this ELISA has high sensitivity, allowing for the detection of 125 to 500 pg/mL of recombinant ChIFN-γ, and also has an excellent capacity for detecting native ChIFN-γ. This ELISA was then used to detect ChIFN-γ level in chickens immunized with a Newcastle disease virus (NDV) vaccine, the immunized chicken splenocytes were stimulated by NDV F protein as recall antigen. From our results, it appears that the sensitivity range of this sandwich ELISA test is adequate to measure the ex vivo release of ChIFN-γ. PMID:27127340

  18. Preparation for gluing of Carbon prototype MAB at INEGI, Porto

    CERN Multimedia

    Miguel Moreira, Porto, INEGI

    2001-01-01

    MAB's will assure the alignment of the CMS detector. It is equipped with muon cameras, measuring the position of the barrel muon stations and at the same time linking via the link elements, connecting the barrel muon detectors with the Tracker. In addition there is a connection with the endcap. More details can be found on the muon/alignment homepage on the web

  19. Analysis of Japanese Municipalities With Geopark, MAB, and GIAHS Certification

    Directory of Open Access Journals (Sweden)

    Ryo Kohsaka

    2015-11-01

    Full Text Available We analyzed the discussions of Japanese municipalities in their process for obtaining certifications for the Geoparks by the United Nations Educational, Scientific and Cultural Organization (UNESCO, the Man and the Biosphere Programme (MAB by the UNESCO, and the Globally Important Agricultural Heritage systems (GIAHS by the Food and Agriculture Organization (FAO of the United Nations. The official records at the municipality diet were analyzed in a quantitative manner from 2011 to 2013. As the first step, we analyzed the eight municipalities of Noto and Sado for the GIAHS, the cities Itoigawa and Hakusan for the Geopark, and Katsuyama Yamanouchi village from Nagano for the MAB. As individual examples, we analyzed City of Suzu with GIAHS, Itoigawa (Geopark, and Yamanouchi town (MAB with the text-mining approach. For the GIAHS, it was clear that the larger municipalities with city status tended to discuss certification issues more frequently than the smaller towns and villages. Terms such as conservation and certification tended to be used with GIAHS at the Suzu City. The term brand was used with GIAHS and MAB but not for the Geopark. The findings using quantitative methods are at initial stage for analysis of municipality strategies and require further future research.

  20. MabCent: Arctic marine bioprospecting in Norway.

    Science.gov (United States)

    Svenson, Johan

    2013-01-01

    The deep waters surrounding the coastline of the northern parts of Norway represent an exciting biotope for marine exploration. Dark and cold Arctic water generates a hostile environment where the ability to adapt is crucial to survival. These waters are nonetheless bountiful and a diverse plethora of marine organisms thrive in these extreme conditions, many with the help of specialised chemical compounds. In comparison to warmer, perhaps more inviting shallower tropical waters, the Arctic region has not been as thoroughly investigated. MabCent is a Norwegian initiative based in Tromsø that aims to change this. Since 2007, scientists within MabCent have focussed their efforts on the study of marine organisms inhabiting the Arctic waters with the long term goal of novel drug discovery and development. The activities of MabCent are diverse and range from sampling the Arctic ice shelf to the chemical synthesis of promising secondary metabolites discovered during the screening process. The current review will present the MabCent pipeline from isolation to identification of new bioactive marine compounds via an extensive screening process. An overview of the main activities will be given with particular focus on isolation strategies, bioactivity screening and structure determination. Pitfalls, hard earned lessons and the results so far are also discussed.

  1. Sandwiched composites in aerospace engineering

    OpenAIRE

    Nunes, J. P.; Silva,J.F.

    2016-01-01

    This chapter considers sandwiched composites used in aerospace applications. Typical sandwich composites consist of two thin, stiff, high-strength facing skins separated by a thick and light core. New developments in the type of face and core materials, production methods and joining and repair techniques are discussed in this chapter. It also discusses various properties as well as their main design methods for existing and future applications of sandwiched composites.

  2. Protective mAbs and Cross-Reactive mAbs Raised by Immunization with Engineered Marburg Virus GPs.

    Directory of Open Access Journals (Sweden)

    Marnie L Fusco

    2015-06-01

    Full Text Available The filoviruses, which include the marburg- and ebolaviruses, have caused multiple outbreaks among humans this decade. Antibodies against the filovirus surface glycoprotein (GP have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific. Many monoclonal antibodies (mAbs have been described against Ebola virus. In contrast, relatively few have been described against Marburg virus. Here we present ten mAbs elicited by immunization of mice using recombinant mucin-deleted GPs from different Marburg virus (MARV strains. Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston, but these epitopes are masked differently by the mucin-like domains themselves. The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola. Two of these anti-wing antibodies confer 90 and 100% protection, respectively, one hour post-exposure in mice challenged with MARV.

  3. Protective mAbs and Cross-Reactive mAbs Raised by Immunization with Engineered Marburg Virus GPs.

    Science.gov (United States)

    Fusco, Marnie L; Hashiguchi, Takao; Cassan, Robyn; Biggins, Julia E; Murin, Charles D; Warfield, Kelly L; Li, Sheng; Holtsberg, Frederick W; Shulenin, Sergey; Vu, Hong; Olinger, Gene G; Kim, Do H; Whaley, Kevin J; Zeitlin, Larry; Ward, Andrew B; Nykiforuk, Cory; Aman, M Javad; Berry, Jody D; Berry, Jody; Saphire, Erica Ollmann

    2015-06-01

    The filoviruses, which include the marburg- and ebolaviruses, have caused multiple outbreaks among humans this decade. Antibodies against the filovirus surface glycoprotein (GP) have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific. Many monoclonal antibodies (mAbs) have been described against Ebola virus. In contrast, relatively few have been described against Marburg virus. Here we present ten mAbs elicited by immunization of mice using recombinant mucin-deleted GPs from different Marburg virus (MARV) strains. Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston), but these epitopes are masked differently by the mucin-like domains themselves. The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola. Two of these anti-wing antibodies confer 90 and 100% protection, respectively, one hour post-exposure in mice challenged with MARV.

  4. Protective mAbs and Cross-Reactive mAbs Raised by Immunization with Engineered Marburg Virus GPs.

    Directory of Open Access Journals (Sweden)

    Marnie L Fusco

    2015-06-01

    Full Text Available The filoviruses, which include the marburg- and ebolaviruses, have caused multiple outbreaks among humans this decade. Antibodies against the filovirus surface glycoprotein (GP have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific. Many monoclonal antibodies (mAbs have been described against Ebola virus. In contrast, relatively few have been described against Marburg virus. Here we present ten mAbs elicited by immunization of mice using recombinant mucin-deleted GPs from different Marburg virus (MARV strains. Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston, but these epitopes are masked differently by the mucin-like domains themselves. The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola. Two of these anti-wing antibodies confer 90 and 100% protection, respectively, one hour post-exposure in mice challenged with MARV.

  5. LpMab-12 Established by CasMab Technology Specifically Detects Sialylated O-Glycan on Thr52 of Platelet Aggregation-Stimulating Domain of Human Podoplanin.

    Directory of Open Access Journals (Sweden)

    Yukinari Kato

    Full Text Available Podoplanin (PDPN, also known as Aggrus, possesses three tandem repeat of platelet aggregation-stimulating (PLAG domains in its N-terminus. Among the PLAG domains, sialylated O-glycan on Thr52 of PLAG3 is essential for the binding to C-type lectin-like receptor-2 (CLEC-2 and the platelet-aggregating activity of human PDPN (hPDPN. Although various anti-hPDPN monoclonal antibodies (mAbs have been generated, no specific mAb has been reported to target the epitope containing glycosylated Thr52. We recently established CasMab technology to develop mAbs against glycosylated membrane proteins. Herein, we report the development of a novel anti-glycopeptide mAb (GpMab, LpMab-12. LpMab-12 detected endogenous hPDPN by flow cytometry. Immunohistochemical analyses also showed that hPDPN-expressing lymphatic endothelial and cancer cells were clearly labeled by LpMab-12. The minimal epitope of LpMab-12 was identified as Asp49-Pro53 of hPDPN. Furthermore, LpMab-12 reacted with the synthetic glycopeptide of hPDPN, corresponding to 38-54 amino acids (hpp3854: 38-EGGVAMPGAEDDVVTPG-54, which carries α2-6 sialylated N-acetyl-D-galactosamine (GalNAc on Thr52. LpMab-12 did not recognize non-sialylated GalNAc-attached glycopeptide, indicating that sialylated GalNAc on Thr52 is necessary for the binding of LpMab-12 to hPDPN. Thus, LpMab-12 could serve as a new diagnostic tool for determining whether hPDPN possesses the sialylation on Thr52, a site-specific post-translational modification critical for the hPDPN association with CLEC-2.

  6. LpMab-23: A Cancer-Specific Monoclonal Antibody Against Human Podoplanin.

    Science.gov (United States)

    Yamada, Shinji; Ogasawara, Satoshi; Kaneko, Mika K; Kato, Yukinari

    2017-04-07

    Human podoplanin (hPDPN), the ligand of C-type lectin-like receptor-2, is involved in cancer metastasis. Until now, many monoclonal antibodies (mAbs) have been established against hPDPN. However, it is still difficult to develop a cancer-specific mAb (CasMab) against hPDPN because the protein sequence of hPDPN expressed in cancer cells is the same as that in normal cells. Herein, we report LpMab-23 of the mouse IgG1 subclass, a novel CasMab against hPDPN. In an immunohistochemical analysis, LpMab-23 reacted with tumor cells of human oral cancer, but did not react with normal cells such as lymphatic endothelial cells (LECs). In contrast, LpMab-17, another anti-hPDPN mAb, reacted with both tumor cells and LECs. Furthermore, flow cytometric analysis revealed that LpMab-23 reacted with hPDPN-expressing cancer cell lines (LN319, RERF-LC-AI/hPDPN, Y-MESO-14/hPDPN, and HSC3/hPDPN) but showed little reaction with normal cells (LECs and HEK-293T), although another anti-hPDPN mAb, LpMab-7, reacted with both hPDPN-expressing cancer cells and normal cells, indicating that LpMab-23 is a CasMab against hPDPN.

  7. The asymmetric sandwich theorem

    CERN Document Server

    Simons, Stephen

    2011-01-01

    We discuss the asymmetric sandwich theorem, a generalization of the Hahn-Banach theorem. As applications, we derive various results on the existence of linear functionals that include bivariate, trivariate and quadrivariate generalizations of the Fenchel duality theorem. Most of the results are about affine functions defined on convex subsets of vector spaces, rather than linear functions defined on vector spaces. We consider both results that use a simple boundedness hypothesis (as in Rockafellar's version of the Fenchel duality theorem) and also results that use Baire's theorem (as in the Robinson-Attouch-Brezis version of the Fenchel duality theorem). This paper also contains some new results about metrizable topological vector spaces that are not necessarily locally convex.

  8. Fracture of sandwiched composites

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Weh-Huei.

    1989-01-01

    Fracture of a pair of collinear cracks in various materials, such as an isotropic strip, an orthotropic strip, a bonded isotropic adhesive layer, and sandwiched orthotropic layers, is investigated. The crack surfaces are subjected to an arbitrary opening pressure p(x). The problems are formulated in terms of Fredholm integral equation of the second kind by making use the techniques of Fourier transform and finite Hilbert transform. In case of uniform opening pressure p(x)={sigma}, exact expressions for the stress intensity factors and the shape of deformed crack are obtained. Numerical calculations are carried out to study the effects of various boundary geometries and material properties on the fracture of the chosen materials.

  9. The effect of unlabelled monoclonal antibody (mAb) on the biodistribution of [sup 131]I-anti-idiotype mAb in murine B cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Schiele, J. (Stanford University (United States). Division of Laboratory Animal Medicine); Knox, S.J. (Stanford University Medical Center (United States). Department of Radiation Oncology); Ruhl, W. (Stanford University (United States). Division of Laboratory Animal Medicine Stanford Univ., CA (United States). Dept. of Radiology); Goris, M.L. (Stanford University Medical Center (United States). Department of Diagnostic Radiology and Nuclear Medicine)

    1992-07-01

    The 38C13 murine B cell lymphoma model was used to study the effect of the pre-injection of unlabelled anti-idiotype monoclonal antibody (mAb) on the subsequent biodistribution of [sup 131]I-anti-idiotype mAb. Mice with established tumors received 0-500 [mu]g of unlabelled anti-idiotype mAb 24 h prior to the administration of [sup 131]I-anti-idiotype (specific), or both [sup 125]I-anti-idiotype and [sup 131]I-isotype-matched irrelevant control (non-specific) mAb. Mice were counted daily in a gamma counter and sacrificed at 2-144 h following injection. Mice were dissected and the weight and activity of the animals and organs were measured. Mice were bled periodically and circulating idiotype levels were measured using an ELISA assay. 500 [mu]g of unlabelled anti-idiotype mAb increased the retention time of the specific but not the nonspecific mAb in all organs and tumor. Following pretreatment with unlabelled mAb, the cumulative tumor/whole body and tumor/normal organ ratios became similar to those of the nonspecific mAb, with concentration ratios (specific/nonspecific mAb) of approximately 1, which persisted until 96 h post injection when circulating idiotype reappears in antigen excess. In the absence of unlabelled mAb there was less retention in tumor and normal tissue. This is presumed to be due in part to decreased levels of circulating [sup 131]I-mAb secondary to rapid plasma clearance of antigen-body complexes and tumor cell mediated dehalogenation, which results when the specific mAb specifically binds the target antigen. Thus, the addition of unlabelled mAb increased the retention by decreasing the specific behavior of the anti-idiotype antibody. (author). 12 refs.; 1 fig.; 3 tabs.

  10. File list: Oth.ALL.05.mab-5.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.05.mab-5.AllCell ce10 TFs and others mab-5 All cell types SRX331286,SRX0056...39,SRX331288,SRX005637,SRX331156,SRX331154 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Oth.ALL.05.mab-5.AllCell.bed ...

  11. Development of Aircraft Sandwich Parts

    Directory of Open Access Journals (Sweden)

    J. Křena

    2000-01-01

    Full Text Available The presented paper shows the design and development process of sandwich parts. A spoiler plate and a main landing gear door are developed. Sandwich parts are made of C/E composite facings and a foam core. FE models have been used for optimization of structures. Emphasis has been placed on deformations of parts under a few load cases. Experimental tests have been used for a verification of structure parts loaded by concentrated forces.

  12. A new approach to quantification of mAb aggregates using peptide affinity probes.

    Science.gov (United States)

    Cheung, Crystal S F; Anderson, Kyle W; Patel, Pooja M; Cade, Keale L; Phinney, Karen W; Turko, Illarion V

    2017-02-10

    Using mAbs as therapeutic molecules is complicated by the propensity of mAbs to aggregate at elevated concentrations, which can lead to a variety of adverse events in treatment. Here, we describe a proof-of-concept for new methodology to detect and quantify mAb aggregation. Assay development included using an aggregated mAb as bait for screening of phage display peptide library and identifying those peptides with random sequence which can recognize mAb aggregates. Once identified, the selected peptides can be used for developing quantitative methods to assess mAb aggregation. Results indicate that a peptide binding method coupled with mass spectrometric detection of bound peptide can quantify mAb aggregation and potentially be useful for monitoring aggregation propensity of therapeutic protein candidates.

  13. Antigen identification and characterization of lung cancer specific monoclonal antibodies produced by mAb proteomics.

    Science.gov (United States)

    Wang, Dongdong; Hincapie, Marina; Guergova-Kuras, Mariana; Kadas, Janos; Takacs, Laszlo; Karger, Barry L

    2010-04-05

    A mass spectrometric (MS)-based strategy for antigen (Ag) identification and characterization of globally produced monoclonal antibodies (mAbs) is described. Mice were immunized with a mixture of native glycoproteins, isolated from the pooled plasma of patients with nonsmall cell lung cancer (NSCLC), to generate a library of IgG-secreting hybridomas. Prior to immunization, the pooled NSCLC plasma was subjected to 3-sequential steps of affinity fractionation, including high abundant plasma protein depletion, glycoprotein enrichment, and polyclonal antibody affinity chromatography normalization. In this paper, to demonstrate the high quality of the globally produced mAbs, we selected 3 mAbs of high differentiating power against a matched, pooled normal plasma sample. After production of large quantities of the mAbs from ascites fluids, Ag identification was achieved by immunoaffinity purification, SDS-PAGE, Western blotting, and MS analysis of in-gel digest products. One antigen was found to be complement factor H, and the other two were mapped to different subunits of haptoglobin (Hpt). The 2 Hpt mAbs were characterized in detail to assess the quality of the mAbs produced by the global strategy. The affinity of one of the mAbs to the Hpt native tetramer form was found to have a K(D) of roughly 10(-9) M and to be 2 orders of magnitude lower than the reduced form, demonstrating the power of the mAb proteomics technology in generating mAbs to the natural form of the proteins in blood. The binding of this mAb to the beta-chain of haptoglobin was also dependent on glycosylation on this chain. The characterization of mAbs in this work reveals that the global mAb proteomics process can generate high-quality lung cancer specific mAbs capable of recognizing proteins in their native state.

  14. MabCampath可有效治疗B-Cell CLL

    Institute of Scientific and Technical Information of China (English)

    杨绍杰(摘)

    2006-01-01

    根据在《临床肿瘤学杂志》第10期上公布的数据,美国GenzymeOncology集团开发的MabCampath(alemtuzumab)(Ⅰ)与Fludara(fludarabine phosphate,伏达拉滨)(Ⅱ)联合使用可有效治疗B细胞慢性淋巴细胞性白血病(B-Cell CLL),在研究期间总应答率为83%。Berlex公司(Schering AG公司的子公司)在美国销售(Ⅰ)。

  15. Industrialization of mAb production technology The bioprocessing industry at a crossroads

    OpenAIRE

    Kelley, Brian

    2009-01-01

    Manufacturing processes for therapeutic monoclonal antibodies (mAbs) have evolved tremendously since the first licensed mAb product in 1986. The rapid growth in product demand for mAbs triggered parallel efforts to increase production capacity through construction of large bulk manufacturing plants as well as improvements in cell culture processes to raise product titers. This combination has led to an excess of manufacturing capacity, and together with improvements in conventional purificati...

  16. Structural and failure mechanics of sandwich composites

    CERN Document Server

    Carlsson, LA; Carlsson, Leif A

    2011-01-01

    Focusing on important deformation and failure modes of sandwich structures, this volume describes the mechanics behind fracture processes. The text also reviews test methods developed for the cr, structural integrity, and failure mechanisms of sandwich structures.

  17. A new monoclonal antibody (5D3-F7) which recognizes human monocyte-chemotactic protein-1 but not related chemokines. Development of a sandwich ELISA and in situ detection of producing cells.

    Science.gov (United States)

    Peri, G; Milanese, C; Matteucci, C; Ruco, L; Zhou, D; Sozzani, S; Coletta, I; Mantovani, A

    1994-09-14

    Chemokines are a superfamily of structurally related cytokines involved in leukocyte recruitment in normal and neoplastic tissues. The availability of non-cross-reacting reagents specific for each member of the C-C and C-X-C family is important for careful characterization of their in vitro and in vivo production and relevance. Here we describe a novel, highly specific, mAb against monocyte chemotactic protein-1 (MCP-1). The 5D3-F7 mAb (IgG1,kappa) recognizes human recombinant and natural MCP-1 in ELISA, immunoprecipitation and immunoblot analysis. As a source of natural MCP-1 we used the 8387 human sarcoma line which produces spontaneously MCP-1 and responds to TNF with increased expression and release. The 5D3-F7 mAb inhibited the chemotactic activity of MCP-1 for monocytes. Using the 5D3-F7 mAb and a polyclonal rabbit anti-MCP-1 serum, a sandwich ELISA was developed. In both the direct and the sandwich ELISA, the 5D3-F7 mAb recognized human MCP-1, but not the closely related C-C chemokines MCP-1, MCP-2, MCP-3, MIP-1 alpha, and RANTES and the C-X-C chemokines IL-8, gro alpha and NAP-2. In culture supernatants the sensitivity of the sandwich ELISA was approximately equal to 30 pg/ml. The sandwich ELISA permitted detection of MCP-1 in resting or cytokine-stimulated endothelial, mesothelial and Kaposi's sarcoma cells. Preliminary immunohistochemical analysis revealed production of MCP-1 by macrophage-like cells at sites of inflammation. The 5D3-F7 mAb provides a novel, highly specific reagent with which to investigate the in vitro and in vivo production and role of MCP-1.

  18. Technology sandwich panels with mineral wool insulation

    OpenAIRE

    Tyulenev M.; Burtzeva M.; Mednikova E.

    2016-01-01

    Sandwich panel — self–supporting structure consisting of metal cladding and thermal insulation core. As a heat–insulating core used mineral wool, foamed plastics. Production of sandwich panels with insulation mineral wool performed on modular lines for the production of aggregate or conveyer scheme. Sandwich panels are used as load–bearing elements of the facades, as well as a roof covering.

  19. Wire and Packing Tape Sandwiches

    Science.gov (United States)

    Rabinowitz, Sandy

    2009-01-01

    In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

  20. Thermal-Diode Sandwich Panel

    Science.gov (United States)

    Basiulis, A.

    1986-01-01

    Thermal diode sandwich panel transfers heat in one direction, but when heat load reversed, switches off and acts as thermal insulator. Proposed to control temperature in spacecraft and in supersonic missiles to protect internal electronics. In combination with conventional heat pipes, used in solar panels and other heat-sensitive systems.

  1. High temperature structural sandwich panels

    Science.gov (United States)

    Papakonstantinou, Christos G.

    High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several

  2. Conservation Compromises: The MAB and the Legacy of the International Biological Program, 1964–1974

    NARCIS (Netherlands)

    Schleper, Simone

    2016-01-01

    This article looks at the International Biological Program (IBP) as the predecessor of UNESCO’s well-known and highly successful Man and the Biosphere Programme (MAB). It argues that international conservation efforts of the 1970s, such as the MAB, must in fact be understood as a compound of two opp

  3. Dynamics of immature mAb glycoform secretion during CHO cell culture

    DEFF Research Database (Denmark)

    Jimenez del Val, Ioscani; Fan, Yuzhou; Weilguny, Dietmar

    2016-01-01

    required to minimise mAb glycoform variability. Our results suggest that the availability of glycosylation machinery relative to cellular secretory capacity may play a crucial role in mAb glycosylation. In the future, the modelling framework presented here may aid in selecting and engineering cell lines...

  4. Immunogenicity of mAbs in non-human primates during nonclinical safety assessment

    NARCIS (Netherlands)

    van Meer, P.J.K.|info:eu-repo/dai/nl/34153790X; Kooijman, M.|info:eu-repo/dai/nl/322905788; Brinks, V.|info:eu-repo/dai/nl/31395979X; Gispen-de Wied, C.C.; Silva-Lima, B.; Moors, E.H.M.|info:eu-repo/dai/nl/20241664X; Schellekens, H.|info:eu-repo/dai/nl/068406762

    2013-01-01

    The immunogenicity of biopharmaceuticals used in clinical practice remains an unsolved challenge in drug development. Non-human primates (NHPs) are often the only relevant animal model for the development of monoclonal antibodies (mAbs), but the immune response of NHPs to therapeutic mAbs is not con

  5. Development and application of triple antibody sandwich enzyme-linked immunosorbent assays for begomovirus detection using monoclonal antibodies against Tomato yellow leaf curl Thailand virus.

    Science.gov (United States)

    Seepiban, Channarong; Charoenvilaisiri, Saengsoon; Warin, Nuchnard; Bhunchoth, Anjana; Phironrit, Namthip; Phuangrat, Bencharong; Chatchawankanphanich, Orawan; Attathom, Supat; Gajanandana, Oraprapai

    2017-05-30

    Tomato yellow leaf curl Thailand virus, TYLCTHV, is a begomovirus that causes severe losses of tomato crops in Thailand as well as several countries in Southeast and East Asia. The development of monoclonal antibodies (MAbs) and serological methods for detecting TYLCTHV is essential for epidemiological studies and screening for virus-resistant cultivars. The recombinant coat protein (CP) of TYLCTHV was expressed in Escherichia coli and used to generate MAbs against TYLCTHV through hybridoma technology. The MAbs were characterized and optimized to develop triple antibody sandwich enzyme-linked immunosorbent assays (TAS-ELISAs) for begomovirus detection. The efficiency of TAS-ELISAs for begomovirus detection was evaluated with tomato, pepper, eggplant, okra and cucurbit plants collected from several provinces in Thailand. Molecular identification of begomoviruses in these samples was also performed through PCR and DNA sequence analysis of the CP gene. Two MAbs (M1 and D2) were generated and used to develop TAS-ELISAs for begomovirus detection. The results of begomovirus detection in 147 field samples indicated that MAb M1 reacted with 2 begomovirus species, TYLCTHV and Tobacco leaf curl Yunnan virus (TbLCYnV), whereas MAb D2 reacted with 4 begomovirus species, TYLCTHV, TbLCYnV, Tomato leaf curl New Delhi virus (ToLCNDV) and Squash leaf curl China virus (SLCCNV). Phylogenetic analyses of CP amino acid sequences from these begomoviruses revealed that the CP sequences of begomoviruses recognized by the narrow-spectrum MAb M1 were highly conserved, sharing 93% identity with each other but only 72-81% identity with MAb M1-negative begomoviruses. The CP sequences of begomoviruses recognized by the broad-spectrum MAb D2 demonstrated a wider range of amino acid sequence identity, sharing 78-96% identity with each other and 72-91% identity with those that were not detected by MAb D2. TAS-ELISAs using the narrow-specificity MAb M1 proved highly efficient for the detection of

  6. Mutations in MAB21L2 result in ocular Coloboma, microcornea and cataracts.

    Directory of Open Access Journals (Sweden)

    Brett Deml

    Full Text Available Ocular coloboma results from abnormal embryonic development and is often associated with additional ocular and systemic features. Coloboma is a highly heterogeneous disorder with many cases remaining unexplained. Whole exome sequencing from two cousins affected with dominant coloboma with microcornea, cataracts, and skeletal dysplasia identified a novel heterozygous allele in MAB21L2, c.151 C>G, p.(Arg51Gly; the mutation was present in all five family members with the disease and appeared de novo in the first affected generation of the three-generational pedigree. MAB21L2 encodes a protein similar to C. elegans mab-21 cell fate-determining factor; the molecular function of MAB21L2 is largely unknown. To further evaluate the role of MAB21L2, zebrafish mutants carrying a p.(Gln48Serfs*5 frameshift truncation (mab21l2Q48Sfs*5 and a p.(Arg51_Phe52del in-frame deletion (mab21l2R51_F52del were developed with TALEN technology. Homozygous zebrafish embryos from both lines developed variable lens and coloboma phenotypes: mab21l2Q48Sfs*5 embryos demonstrated severe lens and retinal defects with complete lethality while mab21l2R51_F52del mutants displayed a milder lens phenotype and severe coloboma with a small number of fish surviving to adulthood. Protein studies showed decreased stability for the human p.(Arg51Gly and zebrafish p.(Arg51_Phe52del mutant proteins and predicted a complete loss-of-function for the zebrafish p.(Gln48Serfs*5 frameshift truncation. Additionally, in contrast to wild-type human MAB21L2 transcript, mutant p.(Arg51Gly mRNA failed to efficiently rescue the ocular phenotype when injected into mab21l2Q48Sfs*5 embryos, suggesting this allele is functionally deficient. Histology, immunohistochemistry, and in situ hybridization experiments identified retinal invagination defects, an increase in cell death, abnormal proliferation patterns, and altered expression of several ocular markers in the mab21l2 mutants. These findings support the

  7. Neutron Reflection Study of Surface Adsorption of Fc, Fab, and the Whole mAb.

    Science.gov (United States)

    Li, Zongyi; Li, Ruiheng; Smith, Charles; Pan, Fang; Campana, Mario; Webster, John R P; van der Walle, Christopher F; Uddin, Shahid; Bishop, Steve M; Narwal, Rojaramani; Warwicker, Jim; Lu, Jian Ren

    2017-07-12

    Characterizing the influence of fragment crystallization (Fc) and antigen-binding fragment (Fab) on monoclonal antibody (mAb) adsorption at the air/water interface is an important step to understanding liquid mAb drug product stability during manufacture, shipping, and storage. Here, neutron reflection is used to study the air/water adsorption of a mAb and its Fc and Fab fragments. By varying the isotopic contrast, the adsorbed amount, thickness, orientation, and immersion of the adsorbed layers could be determined unambiguously. While Fc adsorption reached saturation within the hour, its surface adsorbed amount showed little variation with bulk concentration. In contrast, Fab adsorption was slower and the adsorbed amount was concentration dependent. The much higher Fc adsorption, as compared to Fab, was linked to its lower surface charge. Time and concentration dependence of mAb adsorption was dominated by Fab behavior, although both Fab and Fc behaviors contributed to the amount of mAb adsorbed. Changing the pH from 5.5 to 8.8 did not much perturb the adsorbed amount of Fc, Fab, or mAb. However, a small decrease in adsorption was observed for the Fc over pH 8-8.8 and vice versa for the Fab and mAb, consistent with a dominant Fab behavior. As bulk concentration increased from 5 to 50 ppm, the thicknesses of the Fc layers were almost constant at 40 Å, while Fab and mAb layers increased from 45 to 50 Å. These results imply that the adsorbed mAb, Fc, and Fab all retained their globular structures and were oriented with their short axial lengths perpendicular to the interface.

  8. Development and validation of sensitive sandwich ELISAs for two investigational nonapeptide metastin receptor agonists, TAK-448 and TAK-683.

    Science.gov (United States)

    Yoshida, Nobuyo; Nishizawa, Naoki; Matsui, Hisanori; Moriya, Yuu; Kitada, Chieko; Asami, Taiji; Matsumoto, Hirokazu

    2012-11-01

    TAK-448 and TAK-683, investigational agents with potential utility in the treatment of prostate cancer, are potent low molecular weight metastin receptor agonists consisting of nine amino acids. Monoclonal antibodies (mAbs) against these agents were developed to facilitate their evaluation in preclinical studies. Six mAbs were obtained from four immunogens. Three mAbs recognized the C-terminal of TAK-683 and TAK-448, two recognized the N-terminal of TAK-683, and one recognized the N-terminal of TAK-448. Using various combinations of these six mAbs, sandwich ELISAs for TAK-448 and TAK-683 were developed. These assays were highly sensitive, specific, and accurate. The detection limit for TAK-448 and TAK-683 was 3 and 5 pg/mL, respectively, and there was no interference from rat plasma, rat metastin, or analogs of TAK-448/TAK-683. Recovery achieved ≤±10% with intra-/inter-day assay precision coefficient of variation <10%. The assay demonstrated high stability and sample pre-treatment was not required. Each assay detected the dose-dependent concentration of TAK-448 and TAK-683 in blood 24h after a single intravenous administration of 0.1 and 1mg/kg doses. In conclusion, sensitive sandwich ELISAs were developed to detect the small peptides TAK-448 and TAK-683. The novel assays reliably quantified these nonapeptides in rat plasma, and thus will be useful for preclinical studies of these agents. This methodology may be applicable to the development of similar assays for other short peptides.

  9. Composite Sandwich Technologies Lighten Components

    Science.gov (United States)

    2010-01-01

    Leveraging its private resources with several Small Business Innovation Research (SBIR) contracts with both NASA and the U.S. Department of Defense, WebCore Technologies LLC, of Miamisburg, Ohio, developed a fiber-reinforced foam sandwich panel it calls TYCOR that can be used for a wide variety of industrial and consumer applications. Testing at Glenn Research Center?s Ballistic Impact Facility demonstrated that the technology was able to exhibit excellent damage localization and stiffness during impact. The patented and trademarked material has found use in many demanding applications, including marine, ground transportation, mobile shelters, bridges, and most notably, wind turbines.

  10. Anti-podoplanin Monoclonal Antibody LpMab-7 Detects Metastatic Lesions of Osteosarcoma.

    Science.gov (United States)

    Kaneko, Mika K; Oki, Hiroharu; Ogasawara, Satoshi; Takagi, Michiaki; Kato, Yukinari

    2015-06-01

    Osteosarcoma is the most common primary malignant bone tumor and is highly metastatic to the lungs. Therefore, the development of a novel molecular targeting therapy against metastasis of osteosarcoma is necessary. A platelet aggregation-inducing factor, podoplanin/aggrus, is involved in tumor metastasis. Furthermore, podoplanin expression was reported to be involved in the poor prognosis of osteosarcoma patients. However, the association between podoplanin expression and metastasis of osteosarcoma remains unclear because of the lack of highly sensitive anti-podoplanin monoclonal antibodies (MAbs). In this study, we used a novel anti-podoplanin MAb, LpMab-7, which is more sensitive than well-known anti-podoplanin MAbs in immunohistochemistry. Immunohistochemical analysis using LpMab-7 showed that podoplanin expression at primary lesions is observed in 15 out of 16 (93.8%) cases. Furthermore, podoplanin expression at metastatic lesions was higher compared with primary lesions in three out of four (75%) cases with lung metastasis. Because LpMab-7 has high sensitivity against podoplanin, it is expected to be useful for molecular targeting therapy for osteosarcomas.

  11. Standard Terminology of Structural Sandwich Constructions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This terminology covers terms necessary for a basic uniform understanding and usage of the language peculiar to structural sandwich constructions. The simplest structural sandwich is a three layered construction formed by bonding a thin layer (facing) to each side of a thick layer (core).

  12. Development and Evaluation of Stitched Sandwich Panels

    Science.gov (United States)

    Stanley, Larry E.; Adams, Daniel O.; Reeder, James R. (Technical Monitor)

    2001-01-01

    This study explored the feasibility and potential benefits provided by the addition of through-the-thickness reinforcement to sandwich structures. Through-the-thickness stitching is proposed to increase the interlaminar strength and damage tolerance of composite sandwich structures. A low-cost, out-of-autoclave processing method was developed to produce composite sandwich panels with carbon fiber face sheets, a closed-cell foam core, and through-the-thickness Kevlar stitching. The sandwich panels were stitched in a dry preform state, vacuum bagged, and infiltrated using Vacuum Assisted Resin Transfer Molding (VARTM) processing. For comparison purposes, unstitched sandwich panels were produced using the same materials and manufacturing methodology. Test panels were produced initially at the University of Utah and later at NASA Langley Research Center. Four types of mechanical tests were performed: flexural testing, flatwise tensile testing, core shear testing, and edgewise compression testing. Drop-weight impact testing followed by specimen sectioning was performed to characterize the damage resistance of stitched sandwich panels. Compression after impact (CAI) testing was performed to evaluate the damage tolerance of the sandwich panels. Results show significant increases in the flexural stiffness and strength, out-of-plane tensile strength, core shear strength, edgewise compression strength, and compression-after-impact strength of stitched sandwich structures.

  13. Postmortem distribution of MAB-CHMINACA in body fluids and solid tissues of a human cadaver.

    Science.gov (United States)

    Hasegawa, Koutaro; Wurita, Amin; Minakata, Kayoko; Gonmori, Kunio; Nozawa, Hideki; Yamagishi, Itaru; Watanabe, Kanako; Suzuki, Osamu

    2015-01-01

    During the latter part of 2014, we experienced an autopsy case in which 5-fluoro-ADB, one of the most dangerous synthetic cannabinoids, was identified and quantitated in solid tissues and in three herbal blend products [Forensic Toxicol (2015) 33:112-121]. At that time, although we suspected that there may be some drug(s) other than 5-fluoro-ADB in the herbal products, all trials to find it/them were unsuccessful. Subsequently, we carefully re-examined the presence of other synthetic cannabinoid(s) in the above herbal blend products using accurate mass spectrometry and found two new compounds, 5-fluoro-ADB-PINACA and MAB-CHMINACA (Forensic Toxicol. doi: 10.1007/s 11419-015-0264-y). In the present communication, we report the distribution of MAB-CHMINACA in body fluids and solid tissue specimens collected from the same deceased individual (kept frozen at -80 °C) as described above for demonstration of 5-fluoro-ADB. Unexpectedly, unchanged MAB-CHMINACA could be identified and quantitated in whole blood and in pericardial fluid specimens, but it was below the detection limit (0.1 ng/ml) in the urine specimen. A higher concentration of MAB-CHMINACA could be found in all of the nine solid tissues; the highest concentration of MAB-CHMINACA was found in the liver (156 ng/g), followed by the kidney, pancreas and so on. The compounds were detected in all nine solid tissues; their levels were generally higher than those in the whole blood and pericardial fluid. Contrary to expectations, the concentration of MAB-CHMINACA in the adipose tissue was relatively low. Our results show that the victim smoked one of the three herbal blend products containing both MAB-CHMINACA and 5-fluoro-ADB, resulting in the coexistence of both compounds. It should be concluded that 5-fluoro-ADB and MAB-CHMINACA synergically exerted their toxicities, leading to death after a short interval. The differences in the distribution of 5-fluoro-ADB and MAB-CHMINACA among the cadaver specimens were

  14. Dynamics of immature mAb glycoform secretion during CHO cell culture

    DEFF Research Database (Denmark)

    Jimenez del Val, Ioscani; Fan, Yuzhou; Weilguny, Dietmar

    2016-01-01

    Ensuring consistent glycosylation-associated quality of therapeutic monoclonal antibodies (mAbs) has become a priority in pharmaceutical bioprocessing given that the distribution and composition of the carbohydrates (glycans) bound to these molecules determines their therapeutic efficacy and immu......Ensuring consistent glycosylation-associated quality of therapeutic monoclonal antibodies (mAbs) has become a priority in pharmaceutical bioprocessing given that the distribution and composition of the carbohydrates (glycans) bound to these molecules determines their therapeutic efficacy...... and immunogenicity. However, the interaction between bioprocess conditions, cellular metabolism and the intracellular process of glycosylation remains to be fully understood. To gain further insight into these interactions, we present a novel integrated modelling platform that links dynamic variations in mAb...... glycosylation with cellular secretory capacity. Two alternative mechanistic representations of how mAb specific productivity (qp) influences glycosylation are compared. In the first, mAb glycosylation is modulated by the linear velocity with which secretory cargo traverses the Golgi apparatus. In the second...

  15. Conservation Compromises: The MAB and the Legacy of the International Biological Program, 1964-1974.

    Science.gov (United States)

    Schleper, Simone

    2017-02-01

    This article looks at the International Biological Program (IBP) as the predecessor of UNESCO's well-known and highly successful Man and the Biosphere Programme (MAB). It argues that international conservation efforts of the 1970s, such as the MAB, must in fact be understood as a compound of two opposing attempts to reform international conservation in the 1960s. The scientific framework of the MAB has its origins in disputes between high-level conservationists affiliated with the International Union for the Conservation of Nature and Natural Resources (IUCN) about what the IBP meant for the future of conservation. Their respective visions entailed different ecological philosophies as much as diverging sets of political ideologies regarding the global implementation of conservation. Within the IBP's Conservation Section, one group propagated a universal systems approach to conservation with a centralized, technocratic management of nature and society by an elite group of independent scientific experts. Within IUCN, a second group based their notion of environmental expert roles on a more descriptive and local ecology of resource mapping as practiced by UNESCO. When the IBP came to an end in 1974, both groups' ecological philosophies played into the scientific framework underlying the MAB's World Network or Biosphere Reserves. The article argues that it is impossible to understand the course of conservation within the MAB without studying the dynamics and discourses between the two underlying expert groups and their respective visions for reforming conservation.

  16. New "sandwich" structures conformed from three dimensional

    Directory of Open Access Journals (Sweden)

    Alba, Juan J.

    1996-03-01

    Full Text Available Poor interlaminar properties as well as poor-skin-to-core adhesion properties are very often the common existing problems we find when designing with "sandwich" structures. A new type of 3D-fabric "sandwich" structure is being developed in order to avoid these problems. Although the manufacturing process is very simple, a very complex "sandwich" structure is obtained as a result of the complexity of the 3D-fabric used. This 3D-fabric is a 3D woven glass fabric produced on velvet weaving machines with glass yarns. It is an integrally woven "sandwich" laminate for all kinds of composite products. The strength of the vertical fibers makes, that also after impregnation with a resin matrix, the "sandwich" structure is maintained. The result is a laminate with high strength and stiffness and low weight. On each side of this "sandwich" laminate additional reinforcement materials can be laminated and a synthetic foam can be injected in the hollow structure. This will allow to establish the mechanical properties of a finished product.

    Las pobres propiedades, tanto interlaminares como de adhesión entre piel y núcleo, constituyen uno de los grandes problemas cuando se diseñan estructuras utilizando paneles tipo "sandwich". Un nuevo tipo de panel "sandwich", configurado a partir de tejidos tridimensionales, está siendo desarrollado en la actualidad con el objetivo de eliminar esos problemas. Aunque el proceso de fabricación es muy simple, el panel "sandwich" obtenido es de estructura compleja, como resultado de la complejidad del tejido tridimensional utilizado. Este tejido tridimensional (3D es un tejido de fibra de vidrio producido en máquinas de tejer especializadas. La resistencia de las fibras verticales hace que, después de la impregnación con una resina, se mantenga la configuración tipo "sandwich". El resultado es un laminado de alta resistencia, gran rigidez y bajo peso. Sobre cada uno de los lados del panel "sandwich" se pueden

  17. New "sandwich" structures conformed from three dimensional

    OpenAIRE

    1996-01-01

    Poor interlaminar properties as well as poor-skin-to-core adhesion properties are very often the common existing problems we find when designing with "sandwich" structures. A new type of 3D-fabric "sandwich" structure is being developed in order to avoid these problems. Although the manufacturing process is very simple, a very complex "sandwich" structure is obtained as a result of the complexity of the 3D-fabric used. This 3D-fabric is a 3D woven glass fabric produced on velvet weaving machi...

  18. M.A.B. Vitreous coatings with bactericidal and fungicidal properties; M.A.B. Revestimientos vitreos con propiedades bactericidas y fungicidas

    Energy Technology Data Exchange (ETDEWEB)

    Cuoghi Fenollar, L.; Romero Valiente, J.; Villar Apellaniz, C.; Faubel Serra, V.; Noguera Orti, J. F.; Garcia Ten, J.; Yague Munoz, A.; Duran, A.

    2012-07-01

    This report describes the mosaic M.A.B. (bactericide and fungicide) produced by Togama S.A. belonging to the group Fluidra S.A., which has been awarded with the Silver Alfa Award by the Spanish Society of Ceramics and Glass at the International Fair Cevisama 2012. This award recognizes the R and D efforts developed by Togama, SA, already started with participation in the Alpha Awards 2009 and 2011. (Author)

  19. Buckling driven debonding in sandwich columns

    DEFF Research Database (Denmark)

    Østergaard, Rasmus Christian

    2008-01-01

    A compression loaded sandwich column that contains a debond is analyzed using a geometrically non-linear finite element model. The model includes a cohesive zone along one face sheet/core interface whereby the debond can extend by interface crack growth. Two geometrical imperfections are introduced......; a global imperfection of the sandwich column axis and a local imperfection of the debonded face sheet axis. The model predicts the sandwich column to be very sensitive to the initial debond length and the local face sheet imperfection. The study shows that the sensitivity to the face sheet imperfection...... results from two mechanisms: (a) interaction of local debond buckling and global buckling and (b) the development of a damaged zone at the debond crack tip. Based on the pronounced imperfection sensitivity, the author predicts that an experimental measurement of the strength of sandwich structures may...

  20. Local slamming impact of sandwich composite hulls

    National Research Council Canada - National Science Library

    Qin, Z; Batra, R.C

    2009-01-01

    We develop a hydroelastic model based on a {3,2}-order sandwich composite panel theory and Wagner's water impact theory for investigating the fluid-structure interaction during the slamming process...

  1. On the Milnor fibers of sandwiched singularities

    OpenAIRE

    Nemethi, Andras; Popescu-Pampu, Patrick

    2009-01-01

    The sandwiched surface singularities are those rational surface singularities which dominate birationally smooth surface singularities. de Jong and van Straten showed that one can reduce the study of the deformations of a sandwiched surface singularity to the study of deformations of a 1-dimensional object, a so-called decorated plane curve singularity. In particular, the Milnor fibers corresponding to their various smoothing components may be reconstructed up to diffeomorphisms from those de...

  2. Preparation of anti-ciguatoxin monoclonal antibodies using synthetic haptens: sandwich ELISA detection of ciguatoxins.

    Science.gov (United States)

    Tsumuraya, Takeshi; Fujii, Ikuo; Hirama, Masahiro

    2014-01-01

    Ciguatera fish poisoning (CFP) is a form of food poisoning caused by the consumption of fish that have accumulated a type of sodium channel activator toxin called ciguatoxins (CTXs), which are produced by dinoflagellates of the genus Gambierdiscus through the food chain. CFP affects more than 50000 people each year. The extremely low level of CTXs in tainted fish has hampered the development of antibodies for the detection of these toxins. Monoclonal antibodies (mAbs) specific against major congeners of CTX3C, 51-hydroxyCTX3C, CTX1B, and 54-deoxyCTX1B were prepared by immunization of mice with protein conjugates of rationally designed synthetic haptens in place of the natural toxins. We found that haptenic groups possessing a surface area larger than 400 angstroms2 were required to produce mAbs that can bind strongly to CTXs. Direct sandwich ELISA utilizing two different monoclonal antibodies that bind specifically to one of the two wings of a CTX were established to detect CTXs. No cross-reactivity was observed against the other marine toxins tested, including brevetoxin A, brevetoxin B, okadaic acid, and maitotoxin.

  3. The UNC-4 homeobox protein represses mab-9 expression in DA motor neurons in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Jafari, Gholamali; Appleford, Peter J; Seago, Julian;

    2011-01-01

    The T-box transcription factor mab-9 has been shown to be required for the correct fate of the male-specific blast cells B and F, normal posterior hypodermal morphogenesis, and for the correct axon migration of motor neurons that project circumferential commissures to dorsal muscles. In this stud...

  4. Sorbitol crystallization-induced aggregation in frozen mAb formulations.

    Science.gov (United States)

    Piedmonte, Deirdre Murphy; Hair, Alison; Baker, Priti; Brych, Lejla; Nagapudi, Karthik; Lin, Hong; Cao, Wenjin; Hershenson, Susan; Ratnaswamy, Gayathri

    2015-02-01

    Sorbitol crystallization-induced aggregation of mAbs in the frozen state was evaluated. The effect of protein aggregation resulting from sorbitol crystallization was measured as a function of formulation variables such as protein concentration and pH. Long-term studies were performed on both IgG1 and IgG2 mAbs over the protein concentration range of 0.1-120 mg/mL. Protein aggregation was measured by size-exclusion HPLC (SE-HPLC) and further characterized by capillary-electrophoresis SDS. Sorbitol crystallization was monitored and characterized by subambient differential scanning calorimetry and X-ray diffraction. Aggregation due to sorbitol crystallization is inversely proportional to both protein concentration and formulation pH. At high protein concentrations, sorbitol crystallization was suppressed, and minimal aggregation by SE-HPLC resulted, presumably because of self-stabilization of the mAbs. The glass transition temperature (Tg ') and fragility index measurements were made to assess the influence of molecular mobility on the crystallization of sorbitol. Tg ' increased with increasing protein concentration for both mAbs. The fragility index decreased with increasing protein concentration, suggesting that it is increasingly difficult for sorbitol to crystallize at high protein concentrations.

  5. Multicapillary SDS-gel electrophoresis for the analysis of fluorescently labeled mAb preparations: a high throughput quality control process for the production of QuantiPlasma and PlasmaScan mAb libraries.

    Science.gov (United States)

    Székely, Andrea; Szekrényes, Akos; Kerékgyártó, Márta; Balogh, Attila; Kádas, János; Lázár, József; Guttman, András; Kurucz, István; Takács, László

    2014-08-01

    Molecular heterogeneity of mAb preparations is the result of various co- and post-translational modifications and to contaminants related to the production process. Changes in molecular composition results in alterations of functional performance, therefore quality control and validation of therapeutic or diagnostic protein products is essential. A special case is the consistent production of mAb libraries (QuantiPlasma™ and PlasmaScan™) for proteome profiling, quality control of which represents a challenge because of high number of mAbs (>1000). Here, we devise a generally applicable multicapillary SDS-gel electrophoresis process for the analysis of fluorescently labeled mAb preparations for the high throughput quality control of mAbs of the QuantiPlasma™ and PlasmaScan™ libraries. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Energy Dissipation in Sandwich Structures During Axial Compression

    DEFF Research Database (Denmark)

    Urban, Jesper

    2002-01-01

    The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full-scale structu......The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full...

  7. A multifunctional heat pipe sandwich panel structure

    Energy Technology Data Exchange (ETDEWEB)

    Queheillalt, Douglas T.; Wadley, Haydn N.G. [University of Virginia, Department of Materials Science and Engineering, 140 Chemistry Way, P.O. Box 400745, Charlottesville, VA 22904 (United States); Carbajal, Gerardo [University of Turabo, School of Engineering, P.O. Box 3030, Gurabo 00778 (Puerto Rico); Peterson, G.P. [University of Colorado at Boulder, 914 Broadway, Boulder, CO 80309 (United States)

    2008-01-15

    A multifunctional sandwich panel combining efficient structural load support and thermal management characteristics has been designed and experimentally assessed. The concept is based upon a truncated, square honeycomb sandwich structure. In closed cell honeycomb structures, the transport of heat from one face to the other occurs by a combination of conduction through the webs and convection/radiation within the cells. Here, much more effective heat transport is achieved by multifunctionally utilizing the core as a heat pipe sandwich panel. Its interior consists of a 6061 aluminum truncated-square honeycomb core covered with a stochastic open-cell nickel foam wick. An electroless nickel plating barrier layer inhibited the chemical reaction between the deionized water working fluid and the aluminum structure, retarding the generation of non-condensable hydrogen gas. A thermodynamic model was used to guide the design of the heat pipe sandwich panel. We describe the results of a series of experiments that validate the operational principle of the multifunctional heat pipe sandwich panel and characterize its transient response to an intense localized heat source. The systems measured thermal response to a localized heat source agrees well with that predicted by a finite difference method model used to predict the thermal response. (author)

  8. Sandwich Panels Evaluated With Ultrasonic Spectroscopy

    Science.gov (United States)

    Cosgriff, Laura M.

    2004-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment systems for next-generation engines. The bond strength between the core and face sheets is critical in maintaining the structural integrity of the sandwich structure. To improve the inspection and production of these systems, researchers at the NASA Glenn Research Center are using nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, to evaluate the brazing quality between the face plates and the metallic foam core. The capabilities and limitations of a swept-frequency approach to ultrasonic spectroscopy were evaluated with respect to these sandwich structures. This report discusses results from three regions of a sandwich panel representing different levels of brazing quality between the outer face plates and a metallic foam core. Each region was investigated with ultrasonic spectroscopy. Then, on the basis of the NDE results, three shear specimens sectioned from the sandwich panel to contain each of these regions were mechanically tested.

  9. mab-31 and the TGF-β pathway act in the ray lineage to pattern C. elegans male sensory rays

    Directory of Open Access Journals (Sweden)

    Chan Jacky KF

    2010-08-01

    Full Text Available Abstract Background C. elegans TGF-β-like Sma/Mab signaling pathway regulates both body size and sensory ray patterning. Most of the components in this pathway were initially identified by genetic screens based on the small body phenotype, and many of these mutants display sensory ray patterning defect. At the cellular level, little is known about how and where these components work although ray structural cell has been implicated as one of the targets. Based on the specific ray patterning abnormality, we aim to identify by RNAi approach additional components that function specifically in the ray lineage to elucidate the regulatory role of TGF-β signaling in ray differentiation. Result We report here the characterization of a new member of the Sma/Mab pathway, mab-31, recovered from a genome-wide RNAi screen. mab-31 mutants showed ray cell cluster patterning defect and mis-specification of the ray identity. mab-31 encodes a nuclear protein expressed in descendants of ray precursor cells impacting on the ray cell's clustering properties, orientation of cell division plane, and fusion of structural cells. Genetic experiments also establish its relationship with other Sma/Mab pathway components and transcription factors acting upstream and downstream of the signaling event. Conclusion mab-31 function is indispensable in Sma/Mab signal recipient cells during sensory rays specification. Both mab-31 and sma-6 are required in ray lineage at the late larval stages. They act upstream of C. elegans Pax-6 homolog and repress its function. These findings suggested mab-31 is a key factor that can integrate TFG-β signals in male sensory ray lineage to define organ identity.

  10. EGL-20/Wnt and MAB-5/Hox Act Sequentially to Inhibit Anterior Migration of Neuroblasts in C. elegans.

    Directory of Open Access Journals (Sweden)

    Matthew P Josephson

    Full Text Available Directed neuroblast and neuronal migration is important in the proper development of nervous systems. In C. elegans the bilateral Q neuroblasts QR (on the right and QL (on the left undergo an identical pattern of cell division and differentiation but migrate in opposite directions (QR and descendants anteriorly and QL and descendants posteriorly. EGL-20/Wnt, via canonical Wnt signaling, drives the expression of MAB-5/Hox in QL but not QR. MAB-5 acts as a determinant of posterior migration, and mab-5 and egl-20 mutants display anterior QL descendant migrations. Here we analyze the behaviors of QR and QL descendants as they begin their anterior and posterior migrations, and the effects of EGL-20 and MAB-5 on these behaviors. The anterior and posterior daughters of QR (QR.a/p after the first division immediately polarize and begin anterior migration, whereas QL.a/p remain rounded and non-migratory. After ~1 hour, QL.a migrates posteriorly over QL.p. We find that in egl-20/Wnt, bar-1/β-catenin, and mab-5/Hox mutants, QL.a/p polarize and migrate anteriorly, indicating that these molecules normally inhibit anterior migration of QL.a/p. In egl-20/Wnt mutants, QL.a/p immediately polarize and begin migration, whereas in bar-1/β-catenin and mab-5/Hox, the cells transiently retain a rounded, non-migratory morphology before anterior migration. Thus, EGL-20/Wnt mediates an acute inhibition of anterior migration independently of BAR-1/β-catenin and MAB-5/Hox, and a later, possible transcriptional response mediated by BAR-1/β-catenin and MAB-5/Hox. In addition to inhibiting anterior migration, MAB-5/Hox also cell-autonomously promotes posterior migration of QL.a (and QR.a in a mab-5 gain-of-function.

  11. Vibro-acoustics of lightweight sandwich structures

    CERN Document Server

    Lu, Tianjian

    2014-01-01

    Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

  12. Novel 1-D Sandwich Photonic Bandgap Structure

    Institute of Scientific and Technical Information of China (English)

    庞云波; 高葆新

    2004-01-01

    A sandwich photonic bandgap (PBG) structure is a novel PBG structure whose periodic lattice is buried in the middle of a substrate. Neither drilling nor suspending the substrate is required, and the integrity of the ground plane is maintained. This paper presents several modification techniques for sandwich PBG structure fabrication. The forbidden gap can be improved by adopting the chirping technique, applying the tapering technique, enlarging the periodic elements, adjusting the location of the periodic lattice in the substrate, and using different dielectric media H-shape elements. A finite difference time domain method is applied to analyze the structures. Deep and wide stopbands can be obtained using the modified sandwich structures. Experimental measurement results agree well with the theoretical analysis.

  13. Behaviour of Metal Foam Sandwich Panels

    DEFF Research Database (Denmark)

    2011-01-01

    Sandwich panels as used in structures comprise of a foam core enclosed by thin high strength steel faces. This paper discusses currently design formulae of local buckling behaviour of such panels using the finite element method. Multiple wave finite element models were adopted to investigate...... and examine the adequacy of currently used approach for the design of sandwich panels. The paper presents brief details of the finite element model used including geometry, load pattern and boundary conditions. The selected model gives good agreement with experimental results from Pokharel and Mahendran (2003......). The study shows that currently available design formulae are conservative for stocky sandwich plate elements while being over-conservative for high slenderness. A unified design formula of local buckling behaviour applicable to the full range of slenderness is developed....

  14. AA, sandwich line with magnetic horn

    CERN Multimedia

    1980-01-01

    The magnetic horn, focusing the antiprotons emanating from the target, was affixed to a sandwich line through which the 150 kA pulses were supplied. Expecting to have to change from time to time the fragile horn (inner conductor only 0.7 mm thick), the assembly was designed for quick exchange. At the lower end of the sandwich line we see the connectors for the high-current cables, at the upper end the magnet horn. It has just been lifted from the V-supports which held it aligned downstream of the target. Continue with 8010293.

  15. Hyperglucagonaemia analysed by glucagon sandwich ELISA

    DEFF Research Database (Denmark)

    Albrechtsen, Nicolai Jacob Wewer; Hartmann, Bolette; Veedfald, Simon

    2014-01-01

    characterised. The specific determination of fully processed, intact glucagon requires a 'sandwich' assay employing a combination of antibodies directed against both N- and C-termini. We compared a novel assay for intact glucagon with a highly sensitive C-terminal RIA (hitherto considered specific) to determine...... the extent to which the hyperglucagonaemia measured in clinical samples was caused by authentic glucagon. METHODS: We examined the performance of three commercial glucagon 'sandwich' ELISAs. The ELISA with the best overall performance was selected to compare glucagon measurements in clinical samples...

  16. Nonlinear dynamic analysis of sandwich panels

    Science.gov (United States)

    Lush, A. M.

    1984-01-01

    Two analytical techniques applicable to large deflection dynamic response calculations for pressure loaded composite sandwich panels are demonstrated. One technique utilizes finite element modeling with a single equivalent layer representing the face sheets and core. The other technique utilizes the modal analysis computer code DEPROP which was recently modified to include transverse shear deformation in a core layer. The example problem consists of a simply supported rectangular sandwich panel. Included are comparisons of linear and nonlinear static response calculations, in addition to dynamic response calculations.

  17. OPTIMAL DESIGN OF QUADRATIC SANDWICH PLATE

    Directory of Open Access Journals (Sweden)

    TIMAR Dr. Imre

    2016-05-01

    Full Text Available In this paper, we show the optimal design of the three-layered sandwich plates. The objective function contains the material and fabrication costs. The design constraints are the maximal stresses, the deflection of plates and damping of vibrations. The unknown is the thickness of the filling foam. By the mathematical method, we define the minima of the cost function and the optimal thickness of the filling layer of foam. The active constraint is the deflection, so we calculate of the costs of the sandwich plate with the homogeneous plate.

  18. Advanced Mechanical Testing of Sandwich Materials

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Christian; Jenstrup, Claus

    2008-01-01

    An advanced digital optical system has been used to measure surface strains on sandwich face and core specimens tested in a project concerned with improved criteria for designing sandwich X-joints. The face sheet specimens were of glass reinforced polyester and were tested in tension. The core...... specimens were of PVC foam and were tested in compression. The tests were performed in order to validate the use of the measurement system on these materials and to obtain material data for use in numerical simulations. While some limitations were identified, the optical system performed well and appears...

  19. Detection of botulinum neurotoxin serotype B at sub mouse LD(50 levels by a sandwich immunoassay and its application to toxin detection in milk.

    Directory of Open Access Journals (Sweden)

    Miles C Scotcher

    Full Text Available BACKGROUND: Botulinum neurotoxin (BoNT, the causative agent of botulism, a serious neuroparylatic disease, is produced by the anaerobic bacterium Clostridium botulinum and consists of a family of seven serotypes (A-H. We previously reported production of high-affinity monoclonal antibodies to BoNT serotype A. METHODS AND FINDINGS: Recombinant peptide fragments of the light chain, the transmembrane and receptor-binding domains of the heavy chain of botulinum neurotoxin type B (BoNT/B were expressed in Escherichia coli as GST-fusion proteins and purified. These proteins were used to immunize BALB/cJ mice for the generation of monoclonal antibodies (mAbs. Antibody-producing hybridomas were detected using either a direct binding ELISA binding to plate-immobilized BoNT/B, or with a capture-capture ELISA whereby the capacity of the antibody to capture BoNT/B from solution was tested. A total of five mAbs were selected, two of which bound the toxin light chain and three bound the receptor-binding domain of BoNT/B heavy chain. MAb MCS6-27 was identified via capture-capture ELISA and was the only mAb able to bind BoNT/B in solution under physiological conditions. MAbs F24-1, F26-16, F27-33 and F29-40 were identified via direct binding ELISA, and were able to capture BoNT/B in solution only in the presence of 0.5-0.9 mM sodium dodecyl sulphate (SDS. MAb MCS6-27 and an anti-BoNT/B polyclonal antibody were incorporated into a sandwich ELISA that did not require SDS. CONCLUSIONS: We report here the generation of monoclonal antibodies to serotype B and the subsequent development of a sensitive sandwich immunoassay. This immunoassay has a detection limit of 100 fg BoNT/B, fifty times more sensitive than the mouse bioassay detection limit of 5 pg BoNT/B. Additionally, this assay detected as little as 39 pg/mL of toxin in skim, 2% and whole milk.

  20. Plant Recycling for Molecular Biofarming to Produce Recombinant Anti-cancer mAb

    Directory of Open Access Journals (Sweden)

    Deuk-Su Kim

    2016-07-01

    Full Text Available The expression and glycosylation patterns of anti-colorectal cancer therapeutic monoclonal antibody (mAb CO17-1A recognizing the tumor-associated antigen GA733-2, expressed in human colorectal carcinoma cells, were observed in the leaf and stem tissues of primary (T2; 0 cycle secondary (1 cycle, and tertiary (2 cycle growths of seedlings obtained from the stem cut of T2 plants. The bottom portion of the stem of T2 seedlings was cut to induce the 1 cycle shoot growth, which was again cut to induce the 2 cycle shoot growth. In the 1 and 2 cycle growths, the periods for floral organ formation was shorter (35 days than that (100 days for the 0 cycle growth. The genes of heavy and light chains of mAb CO17-1A existed at the top, middle, and basal portions of the leaves and stem obtained from the 0, 1, and 2 cycle plants. The protein levels in the leaves and stem tissues from the 1 and 2 cycles were similar to those in the tissues from the 0 cycle. The glycosylation level and pattern in the leaf and stem did not alter dramatically over the different cycles. Surface plasmon resonance (SPR confirmed that mAbs CO17-1A obtained from leaf and stem tissues of the 0, 1, and 2 cycles had similar binding affinity for the GA733-2 antigen. These data suggest that the shoot growth by bottom stem cutting is applicable to speed up the growth of plant biomass expressing anti-colorectal cancer mAb without variation of expression, glycosylation, and functionality.

  1. MAB4-induced auxin sink generates local auxin gradients in Arabidopsis organ formation.

    Science.gov (United States)

    Furutani, Masahiko; Nakano, Yasukazu; Tasaka, Masao

    2014-01-21

    In Arabidopsis, leaves and flowers form cyclically in the shoot meristem periphery and are triggered by local accumulations of the plant hormone auxin. Auxin maxima are established by the auxin efflux carrier PIN-formed1 (PIN1). During organ formation, two distinct types of PIN1 polarization occur. First, convergence of PIN1 polarity in the surface of the meristem creates local auxin peaks. Second, basipetal PIN1 polarization causes auxin to move away from the surface in the middle of an incipient organ primordium, thought to contribute to vascular formation. Several mathematical models have been developed in attempts to explain the PIN1 localization pattern. However, the molecular mechanisms that control these dynamic changes are unknown. Here, we show that loss-of-function in the MACCHI-BOU 4 (MAB4) family genes, which encode nonphototropic hypocotyl 3-like proteins and regulate PIN endocytosis, cause deletion of basipetal PIN1 polarization, resulting in extensive auxin accumulation all over the meristem surface from lack of a sink for auxin. These results indicate that the MAB4 family genes establish inward auxin transport from the L1 surface of incipient organ primordia by basipetal PIN1 polarization, and that this behavior is essential for the progression of organ development. Furthermore, the expression of the MAB4 family genes depends on auxin response. Our results define two distinct molecular mechanisms for PIN1 polarization during organ development and indicate that an auxin response triggers the switching between these two mechanisms.

  2. Preparation of knockout extract for determination of really active compound using MAb.

    Science.gov (United States)

    Uto, Takuhiro; Tuvshintogtokh, Indree; Shoyama, Yukihiro

    2011-03-01

    The crude-rhizome extract of P. japonicus was loaded on the immunoaffinity column conjugated with anti- ginsenoside-Rb1 monoclonal antibody (MAb) and washed with the washing solvent, followed by elution solvent, to give fraction 2 containing higher concentration of compound 1. Compound 1 clearly indicated a dammarane saponin having protopanaxadiol as a framework and three sugars in a molecule suggesting that compound 1 is chikusetsusaponin III. Compound 2 was also determined as chikusetsusaponin VI compared to the staining color, its Rf value and the comparison with ginsenoside Rb1. We succeeded in one step purification of ginsenoside-Rb1 by immunoaffinity column conjugated with anti- ginsenoside-Rb1 MAb leading to the knock-out extract which will be useful for pharmacological investigation. The antibody was stable when exposed to the eluent, and the immunoaffinity column showed almost no decrease in capacity after repeated use more than 10 times under the same conditions. From the crude extract of licorice we isolated glycyrrhizin by one-step purification by the immunoaffinity column using anti-glycyrrhizin MAb. Washing fraction contained all components except for only glycyrrhizin and was named as the knockout extract. We confirmed the synergic effect of glycyrrhizin with some other components for the inhibition of nitric oxide (NO) production by blocking inducible nitric oxide synthase (iNOS) expression by using its knockout extract.

  3. Industrialization of mAb production technology: the bioprocessing industry at a crossroads.

    Science.gov (United States)

    Kelley, Brian

    2009-01-01

    Manufacturing processes for therapeutic monoclonal antibodies (mAbs) have evolved tremendously since the first licensed mAb product in 1986. The rapid growth in product demand for mAbs triggered parallel efforts to increase production capacity through construction of large bulk manufacturing plants as well as improvements in cell culture processes to raise product titers. This combination has led to an excess of manufacturing capacity, and together with improvements in conventional purification technologies, promises nearly unlimited production capacity in the foreseeable future. The increase in titers has also led to a marked reduction in production costs, which could then become a relatively small fraction of sales price for future products which are sold at prices at or near current levels. The reduction of capacity and cost pressures for current state-of-the-art bulk production processes may shift the focus of process development efforts and have important implications for both plant design and product development strategies for both biopharmaceutical and contract manufacturing companies.

  4. TGF-beta Sma/Mab signaling mutations uncouple reproductive aging from somatic aging.

    Directory of Open Access Journals (Sweden)

    Shijing Luo

    2009-12-01

    Full Text Available Female reproductive cessation is one of the earliest age-related declines humans experience, occurring in mid-adulthood. Similarly, Caenorhabditis elegans' reproductive span is short relative to its total life span, with reproduction ceasing about a third into its 15-20 day adulthood. All of the known mutations and treatments that extend C. elegans' reproductive period also regulate longevity, suggesting that reproductive span is normally linked to life span. C. elegans has two canonical TGF-beta signaling pathways. We recently found that the TGF-beta Dauer pathway regulates longevity through the Insulin/IGF-1 Signaling (IIS pathway; here we show that this pathway has a moderate effect on reproductive span. By contrast, TGF-beta Sma/Mab signaling mutants exhibit a substantially extended reproductive period, more than doubling reproductive span in some cases. Sma/Mab mutations extend reproductive span disproportionately to life span and act independently of known regulators of somatic aging, such as Insulin/IGF-1 Signaling and Dietary Restriction. This is the first discovery of a pathway that regulates reproductive span independently of longevity and the first identification of the TGF-beta Sma/Mab pathway as a regulator of reproductive aging. Our results suggest that longevity and reproductive span regulation can be uncoupled, although they appear to normally be linked through regulatory pathways.

  5. New examples of sandwich gravitational waves and their impulsive limit

    CERN Document Server

    Podolsky, J

    1998-01-01

    Non-standard sandwich gravitational waves are constructed from the homogeneous pp vacuum solution and the motions of free test particles in the space-times are calculated explicitly. They demonstrate the caustic property of sandwich waves. By performing limits to impulsive gravitational wave it is demonstrated that the resulting particle motions are identical regardless of the ''initial'' sandwich.

  6. Non-linear analytical solutions for laterally loaded sandwich plates

    DEFF Research Database (Denmark)

    Riber, Hans Jørgen

    1997-01-01

    This work focuses on the response of orthotropic sandwich composite plates with large deflections due to high lateral loads. The results have special application to the design of ship structures. A geometrical nonlinear theory is outlined, on the basis of the classical sandwich plate theory...... of sandwich plates subjected to high lateral loading. (C) 1997 Published by Elsevier Science Ltd. All rights reserved....

  7. H2Mab-77 is a Sensitive and Specific Anti-HER2 Monoclonal Antibody Against Breast Cancer.

    Science.gov (United States)

    Itai, Shunsuke; Fujii, Yuki; Kaneko, Mika K; Yamada, Shinji; Nakamura, Takuro; Yanaka, Miyuki; Saidoh, Noriko; Chang, Yao-Wen; Handa, Saori; Takahashi, Maki; Suzuki, Hiroyoshi; Harada, Hiroyuki; Kato, Yukinari

    2017-08-01

    Human epidermal growth factor receptor 2 (HER2) plays a critical role in the progression of breast cancers, and HER2 overexpression is associated with poor clinical outcomes. Trastuzumab is an anti-HER2 humanized antibody that leads to significant survival benefits in patients with HER2-positive metastatic breast cancers. In this study, we developed novel anti-HER2 monoclonal antibodies (mAbs) and characterized their efficacy in flow cytometry, Western blot, and immunohistochemical analyses. Initially, we expressed the full length or ectodomain of HER2 in LN229 glioblastoma cells and then immunized mice with ectodomain of HER2 or LN229/HER2, and performed the first screening by enzyme-linked immunosorbent assays using ectodomain of HER2. Subsequently, we selected mAbs according to their efficacy in flow cytometry (second screening), Western blot (third screening), and immunohistochemical analyses (fourth screening). Among 100 mAb clones, only three mAbs reacted with HER2 in Western blot, and clone H2Mab-77 (IgG1, kappa) was selected. Finally, immunohistochemical analyses with H2Mab-77 showed sensitive and specific reactions against breast cancer cells, warranting the use of H2Mab-77 to detect HER2 in pathological analyses of breast cancers.

  8. AA, sandwich line with magnetic horn

    CERN Document Server

    1980-01-01

    Continuation from 8010293: Finally, the sandwich line with the horn is placed on the ground, for the horn to be inspected and, if needed, exchanged for a new one. The whole procedure was trained with several members of the AA team, for quick and safe handling, and to share the radiation dose amongst them.

  9. Proof of the Thin Sandwich Conjecture

    CERN Document Server

    Bartnik, R; Bartnik, Robert; Fodor, Gyula

    1993-01-01

    We prove that the Thin Sandwich Conjecture in general relativity is valid, provided that the data $(g_{ab},\\dot g_{ab})$ satisfy certain geometric conditions. These conditions define an open set in the class of possible data, but are not generically satisfied. The implications for the ``superspace'' picture of the Einstein evolution equations are discussed.

  10. Behaviour of Metal Foam Sandwich Panels

    DEFF Research Database (Denmark)

    2011-01-01

    Sandwich panels as used in structures comprise of a foam core enclosed by thin high strength steel faces. This paper discusses currently design formulae of local buckling behaviour of such panels using the finite element method. Multiple wave finite element models were adopted to investigate...

  11. Structural detailing of openings in sandwich panels

    NARCIS (Netherlands)

    Tomà, T.; Courage, W.

    1996-01-01

    European Recommendations exist which provide calculation rules to determine the strength and stiffness of sandwich panels composed of two metal faces with a foam in between. In case of openings in such panels (e.g. for windows) an influence will appear with regard to the stiffness and loadbearing ca

  12. X-joints in composite sandwich panels

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Janssen, G.Th.M.

    1998-01-01

    The small structural weight of fast large ships such as fast mono hulls or catamaran type of ships is of extreme importance to their success. One possible light weight structural solution is the sandwich panel with fibre reinforced laminates and a balsa, honeycomb or foam core. A severe obstacle for

  13. Organometallic half-sandwich iridium anticancer complexes

    NARCIS (Netherlands)

    Liu, Z.; Habtemariam, A.; Pizarro, A.M.; Fletcher, S.A.; Kisova, A.; Vrana, O.; Salassa, L.; Bruijnincx, P.C.A.|info:eu-repo/dai/nl/33799529X; Clarkson, G.J.; Brabec, V.; Sadler, Peter J.

    2011-01-01

    The low-spin 5d6 IrIII organometallic half-sandwich complexes [(η5-Cpx)Ir(XY)Cl]0/+, Cpx = Cp*, tetramethyl(phenyl)cyclopentadienyl (Cpxph), or tetramethyl(biphenyl)cyclopentadienyl (Cpxbiph), XY = 1,10-phenanthroline (4−6), 2,2′-bipyridine (7−9), ethylenediamine (10 and 11), or picolinate (12−14),

  14. Feedback Sandwiches Affect Perceptions but Not Performance

    Science.gov (United States)

    Parkes, Jay; Abercrombie, Sara; McCarty, Teresita

    2013-01-01

    The feedback sandwich technique-make positive comments; provide critique; end with positive comments-is commonly recommended to feedback givers despite scant evidence of its efficacy. These two studies (N = 20; N = 350) of written peer feedback with third-year medical students on clinical patient note-writing assignments indicate that students…

  15. X-joints in composite sandwich panels

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Janssen, G.Th.M.

    1998-01-01

    The small structural weight of fast large ships such as fast mono hulls or catamaran type of ships is of extreme importance to their success. One possible light weight structural solution is the sandwich panel with fibre reinforced laminates and a balsa, honeycomb or foam core. A severe obstacle for

  16. Results from a survey of the dynamics shaping Uranus' Mab/μ-ring system

    Science.gov (United States)

    Kumar, Kartik; de Pater, Imke; Showalter, Mark R.

    2014-11-01

    Based on Hubble Space Telescope (HST) data, Showalter and Lissauer (2006) reported the discovery of two faint rings beyond Uranus’ main rings: the ν- and μ- rings. They constitute Uranus' outer ring system and are located beyond the ɛ-ring but interior to the large classical moons. After co-adding a series of HST images, Showalter and Lissauer (2006) obtained radial profiles for both new rings. They discovered that the peak radial intensity of the μ-ring aligns closely with the orbit of Mab. Along with numerous other observations, this points to the fact that the Mab/μ-ring system is highly coupled.The discovery of the μ-ring has led to open questions about dust dynamics beyond Uranus' main rings. Like Saturn's E-ring, observations reveal that the μ-ring is blue, indicative of a pre-dominance of sub-micron-sized particles (de Pater et al., 2006). The E-ring results from plumes on Enceladus' south pole, however the origin of the μ-ring remains a mystery. The latter is likely fed by ejecta from micro-meteorite impacts with Mab, much like Jupiter's faint rings are regenerated by companion (small) moons (Burns et al., 1999). The μ-ring's steep size-distribution suggests that there is an unknown mechanism at play that hides or removes large dust particles. We present results from an investigation into the forces shaping the μ-ring. To simulate the motion of dust in the Mab/μ-ring system, we developed a numerical toolbox (Dustsim; Kumar et al., 2015) that uses Tudat (Kumar et al., 2012). We performed integrations using Dustsim that included the effects of Uranus' gravity field, titled magnetic moment, solar radiation pressure, and collisions with a putative suite of large μ-ring bodies, hypothesized as the cause of Mab's anomalous orbital motion (Kumar et al., 2014). Following on from previous studies (e.g., Sfair and Giuliatti Winter, 2009; Sfair and Giuliatti Winter, 2012), we present a survey of the expected lifetime of μ-ring dust, as a function of

  17. HYBRID-SANDWICHED REINFORCEMENT WITH GEOSYNTHETICS

    Science.gov (United States)

    Yasuhara, Kazuya; Yamazaki, Shinji; Sakakibara, Tsutomu

    Advantageous aspects of sandwich-type reinforced earth structures combined with geosynthetics and sand mat are highlighted in this paper. Those aspects were elucidated by two kinds of laboratory tests : (1) large consolidation tests for improvement of hydraulic conductivity and (2) model footing tests on improvement of bearing capacity and deformation characteristics for reinforced earth structures, including both vertical permeability and horizontal transmissibility characteristics of geosynthetics results from both laboratory tests indicated the following: i) Hydraulic conductivity of geosynthetics used for this type of earth reinforcement can be maintained for a long period. Such conductivity sometimes disappears, particularly because of clogging when geosynthetics are adopted in embankment construction using fine-grained soils. This fact indicates that the sand mats which are laid above and beneath geosynthetics play a salient role in preventing clogging of geosynthetics that occurs by intrusion of fines from cohesive soils. ii) Sandwich-type reinforcement combined with geosynthetics and sand mats increases stability and decreases deformation of earth structures. In particular, the sandwich structure is effective for providing toughness, which has remained an important issue for reducing infrastructural maintenance and costs. In the later part of the paper, conventionally available stability analysis was carried out to propose the design procedure for reinforced earth structures and at the same time numerical analysis was also conducted to ensure the applicability of the hybrid-sandwiched earth reinforcement newly proposed in the current paper. Finally, based on the horizontal placement by means of HBS described in the current paper, the vertical drain procedure using the sandwich structures for accelerating consolidation and increasing stability of soft soils is also suggested for the future research and investigation.

  18. Structural Analysis of Sandwich Foam Panels

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Huo, X. Sharon [Tennessee Technological University

    2010-04-01

    The Sandwich Panel Technologies including Structural Insulated Panels (SIPs) can be used to replace the conventional wooden-frame construction method. The main purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC and SGI Venture, Inc. was to design a novel high R-value type of metal sandwich panelized technology. This CRADA project report presents design concept discussion and numerical analysis results from thermal performance study of this new building envelope system. The main objective of this work was to develop a basic concept of a new generation of wall panel technologies which will have R-value over R-20 will use thermal mass to improve energy performance in cooling dominated climates and will be 100% termite resistant. The main advantages of using sandwich panels are as follows: (1) better energy saving structural panels with high and uniform overall wall R-value across the elevation that could not be achieved in traditional walls; and (2) reducing the use of raw materials or need for virgin lumber. For better utilization of these Sandwich panels, engineers need to have a thorough understanding of the actual performance of the panels and system. Detailed analysis and study on the capacities and deformation of individual panels and its assembly have to be performed to achieve that goal. The major project activity was to conduct structural analysis of the stresses, strains, load capacities, and deformations of individual sandwich components under various load cases. The analysis simulated the actual loading conditions of the regular residential building and used actual material properties of the steel facings and foam.

  19. Sequence analysis and mRNA expression of mab-21 gene in the Chinese honeybee, Apis cerana cerana (Hymenoptera: Apidae)%中华蜜蜂mab-21基因序列分析及表达特征

    Institute of Scientific and Technical Information of China (English)

    薛菲; 吴鹏杰; 李雨时; 王秀红; 国占宝; 徐书法; 吴杰

    2015-01-01

    [目的]探究中华蜜蜂Apis cerana cerana Male abnomal 21(mab-21)基因在不同发育阶段的表达特性及染螨条件下mab-21基因表达变化规律.[方法]本研究利用RT-PCR方法,克隆了中华蜜蜂mab-21的基因编码区;采用荧光定量PCR方法检测了中华蜜蜂mab-21在不同发育时期(新出房蜂、哺育蜂、守卫蜂及采集蜂)工蜂头部中mRNA的表达量以及接种大蜂螨Varroa destructor前后mab-21基因的表达变化.[结果]克隆获得中华蜜蜂mab-21cDNA,命名为Accmab21(GenBank登录号KR000001).序列分析显示,该编码区开放阅读框长为1 098 bp,编码365个氨基酸,推测的编码蛋白的相对分子量和等电点分别为41.63 kD和8.53.系统发育分析表明中华蜜蜂mab-21与西方蜜蜂Apis mellifera mab-21、小蜜蜂Apis florea mab-21和熊蜂Bombus impatiens mab-21聚成一支.该基因在中华蜜蜂工蜂的不同发育时期均有表达,其中哺育蜂阶段显著高于新出房蜂、守卫蜂和采集蜂(P<0.05).接种大蜂螨后,哺育蜂和守卫蜂中mab-21基因的表达下降显著(P<0.05);而在新出房蜂和采集蜂中表达量变化不显著.[结论]该基因可能与中华蜜蜂抗螨行为相关.

  20. Generation, characterization and therapeutic potential of anti-feline TNF-alpha MAbs for feline infectious peritonitis.

    Science.gov (United States)

    Doki, Tomoyoshi; Takano, Tomomi; Nishiyama, Yuri; Nakamura, Michiyo; Hohdatsu, Tsutomu

    2013-12-01

    Feline infectious peritonitis (FIP) is a lethal infectious disease affecting domestic and wild cats. Several reports suggested that TNF-alpha is related to the progression of FIP. Thus, the administration of a feline TNF-alpha-neutralizing antibody to cats with FIP may reduce the disease progression. In this study, we have prepared nine monoclonal antibodies (MAbs) that recognize feline TNF-alpha. All MAbs neutralized recombinant TNF-alpha. The 50% inhibitory concentrations (IC50) of the MAbs for the cytotoxicity of recombinant TNF-alpha were 5-684 ng/ml. MAb 2-4 exhibited high neutralizing activity against natural TNF-alpha derived from FIPV-infected macrophages, and was confirmed to inhibit the following feline TNF-alpha-induced conditions in vitro: (i) an increase in the survival rate of neutrophils from cats with FIP, (ii) aminopeptidase N (APN) mRNA expression in macrophages, and (iii) apoptosis of a feline T-lymphocyte cell line.

  1. Mab-3 is a direct tra-1 target gene regulating diverse aspects of C. elegans male sexual development and behavior.

    Science.gov (United States)

    Yi, W; Ross, J M; Zarkower, D

    2000-10-01

    Sex determination is controlled by global regulatory genes, such as tra-1 in Caenorhabditis elegans, Sex lethal in Drosophila, or Sry in mammals. How these genes coordinate sexual differentiation throughout the body is a key unanswered question. tra-1 encodes a zinc finger transcription factor, TRA-1A, that regulates, directly or indirectly, all genes required for sexual development. mab-3 (male abnormal 3), acts downstream of tra-1 and is known to be required for sexual differentiation of at least two tissues. mab-3 directly regulates yolk protein transcription in the intestine and specifies male sense organ differentiation in the nervous system. It encodes a transcription factor related to the products of the Drosophila sexual regulator doublesex (dsx), which also regulates yolk protein transcription and male sense-organ differentiation. The similarities between mab-3 and dsx led us to suggest that some aspects of sex determination may be evolutionarily conserved. Here we find that mab-3 is also required for expression of male-specific genes in sensory neurons of the head and tail and for male interaction with hermaphrodites. These roles in male development and behavior suggest further functional similarity to dsx. In male sensory ray differentiation we find that MAB-3 acts synergistically with LIN-32, a neurogenic bHLH transcription factor. Expression of LIN-32 is spatially restricted by the combined action of the Hox gene mab-5 and the hairy homolog lin-22, while MAB-3 is expressed throughout the lateral hypodermis. Finally, we find that mab-3 transcription is directly regulated in the intestine by TRA-1A, providing a molecular link between the global regulatory pathway and terminal sexual differentiation.

  2. P3 mAb: An Immunogenic Anti-NeuGcGM3 Antibody with Unusual Immunoregulatory Properties.

    Science.gov (United States)

    Martínez, Darel; Rodríguez, Nely; Griñán, Tania; Rondón, Teresa; Vázquez, Ana María; Pérez, Rolando; Hernández, Ana María

    2012-01-01

    P3 is a murine IgM mAb that recognize N-glycosylated gangliosides, sulfatides, and antigens expressed in melanoma, breast, and lung human tumors. This antibody has the ability to trigger an IgG antibody response in the syngeneic BALB/c model, even when it is administered in the absence of adjuvant or carrier protein. The mechanism by which the P3 mAb, a self-immunoglobulin, induce this immune response in the absence of co-stimulatory or classical danger signals is still unknown. In the present paper we show that the high immunogenicity of P3 mAb depends not only on CD4 but also on CD8(+) T cells, since the depletion of CD8(+) or CD4(+) T cells led to the loss of P3 mAb immunogenicity in the syngeneic model. Furthermore, the immunization with P3 mAb enhanced the recovery of the CD8(+) T cell population in mice treated with an anti-CD8a antibody. Additionally, the immunization with P3 mAb restored the capacity of immunosuppressed mice to reject allogeneic tumors, a mechanism mediated by the action of CD8(+) T cells. Finally, in mice with cyclophosphamide induced lymphopenia, the administration of P3 mAb accelerated the recovery of both CD4(+) and CD8(+) T cells. These results show new possibilities for B and CD8(+) T cells interactions during the immune response elicited by a self-protein. Furthermore they point to P3 mAb as a potential interesting candidate for the treatment of immunosuppressed patients.

  3. P3 mAb: an immunogenic anti-NeuGcGM3 antibody with unusual immunoregulatory properties.

    Directory of Open Access Journals (Sweden)

    Darel eMartínez

    2012-04-01

    Full Text Available P3 is a murine IgM mAb that recognize N-glycolilated gangliosides, sulphatides and antigens expressed in melanoma, breast and lung human tumors. This antibody has the ability to trigger an IgG antibody response in the syngeneic BALB/c model, even when it is administered in the absence of adjuvant or carrier protein. The mechanism by which the P3 mAb, a self immunoglobuline, induce this immune response in the absence of co-stimulatory or classical danger signals is still unknown. In the present paper we show that the high immunogenicity of P3 mAb depends not only on CD4 but also on CD8+ T cells, since the depletion of CD8+ or CD4+ T cells led to the loss of P3 mAb immunogenicity in the syngeneic model. Furthermore, the immunization with P3 mAb enhanced the recovery of the CD8+ T cell population in mice treated with an anti-CD8a antibody. Additionally, the immunization with P3 mAb restored the capacity of immunosuppressed mice to reject allogeneic tumors, a mechanism mediated by the action of CD8+ T cells. Finally, in mice with cyclophosphamide induced lymphopenia, the administration of P3 mAb accelerated the recovery of both CD4+ and CD8+ T cells. These results show new possibilities for B and CD8+ T cells interactions during the immune response elicited by a self-protein. Furthermore they point to P3 mAb as a potential interesting candidate for the treatment of immunosuppressed patients.

  4. Prognostic Role of 14F7 Mab Immunoreactivity against N-Glycolyl GM3 Ganglioside in Colon Cancer

    Directory of Open Access Journals (Sweden)

    Tania Lahera

    2014-01-01

    Full Text Available Purpose. To assess the prognostic role of 14F7 Mab immunoreactivity, against N-Glycolyl GM3 ganglioside, in patients with colon cancer (CC and to evaluate the relationship between its expression and clinicopathological features. Methods. Paraffin-embedded specimens were retrospectively collected from 50 patients with CC operated between 2004 and 2008. 14F7 Mab staining was determined by immunohistochemistry technique and its relation with survival and clinicopathologic features was evaluated. Results. The reactivity of 14F7 Mab was detected in all cases. Most cases had high level of immunostaining (70% that showed statistical correlation with TNM stage (P=0.025. In univariate survival analysis, level of 14F7 Mab immunoreactivity (P=0.0078, TNM Stage (P=0.0007 and lymphovascular invasion (0.027 were significant prognostic factors for overall survival. Among these variables, level of 14F7 Mab immunoreactivity  (HR=0.268; 95%  CI  0.078–0.920; P=0.036 and TNM stage (HR=0.249; 95%  CI   0.066–0.932; P=0.039 were independent prognostic factors on multivariate analysis. Conclusions. This study is the first approach on the prognostic significance of 14F7 Mab immunoreactivity in patients with colon adenocarcinoma and this assessment might be used in the prognostic estimate of CC, although further studies will be required to validate these findings.

  5. A sandwich ELISA for the detection of neuraminidase of avian influenza A(H7N9) virus.

    Science.gov (United States)

    Yu, Yueyang; Zhang, Xi; Zhao, Baihui; Sun, Ying; Zhang, Xiaoguang; Bai, Tian; Lu, Jian; Li, Zi; Liu, Liqi; Wang, Dayan; Shu, Yuelong; Zhou, Jianfang; Qin, Kun

    2017-09-01

    Although exhibiting no or low virulence in poultry, avian influenza virus H7N9 has caused around 1400 confirmed human infections in China with a case-fatality rate of 30% since 2013. A highly pathogenic H7N9 virus (HP-H7), with the HA antigenicity distinct from the previous, were recently detected in patients and poultry. Therefore, convenient rapid diagnosis with reliability will allow early antiviral use and management for H7N9 infection. Here, a sandwich ELISA targeting the conserved viral antigen, neuraminidase (NA) was developed. The immunoassay employed mouse monoclonal antibody (mAb) 3C1 to specifically capture the N9 and 3E9 for the detection. Its limit of detection is 6.25ng/ml for N9 protein of A/Anhui/1/2013(H7N9, AH1/2013) and 0.125HAU/50μL for live virus, AH1/2013 and A/Environment/Jiangxi/28/2009 (H11N9), respectively. When applied to test the five clinic throat swabs from H7N9 patients confirmed by nuclear acid testing (NAT) using quantitative reverse-transcriptase polymerase chain reaction (Q-PCR), two samples showed positive result in sandwich ELISA while all were negative using commercial Flu A and H7 subtype rapid antigen tests (RAT). The ELISA using anti-N9 mAbs provided a valuable approach to detect H7N9 virus and quantify the N9 protein. Copyright © 2017. Published by Elsevier B.V.

  6. On the Milnor fibers of sandwiched singularities

    CERN Document Server

    Nemethi, Andras

    2009-01-01

    The sandwiched surface singularities are those rational surface singularities which dominate birationally smooth surface singularities. de Jong and van Straten showed that one can reduce the study of the deformations of a sandwiched surface singularity to the study of deformations of a 1-dimensional object, a so-called decorated plane curve singularity. In particular, the Milnor fibers corresponding to their various smoothing components may be reconstructed up to diffeomorphisms from those deformations of associated decorated curves which have only ordinary singularities. Part of the topology of such a deformation is encoded in the incidence matrix between the irreducible components of the deformed curve and the points which decorate it, well-defined up to permutations of columns. Extending a previous theorem ofours, which treated the case of cyclic quotient singularities, we show that the Milnor fibers which correspond to deformations whose incidence matrices are different up to permutations of columns are n...

  7. Utilization of Bamboo as Lightweight Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Suthon SRIVARO

    2016-05-01

    Full Text Available Lightweight sandwich panels consisting of bamboo faces and oil palm trunk core were manufactured using melamine urea formaldehyde with the resin content of 250 g/m2 (solid basis. The parameters examined were node and density of bamboo faces. Physical (board density, thickness swelling and water absorption and mechanical (modulus of elasticity and modulus of rupture properties of the sandwich board obtained were investigated and compared with other bamboo products and commercial wood based products. Result showed that this panel had better dimensional stability than those of other bamboo products but lower bending strength. Node of bamboo had no significant effect on any board properties examined. Most of board properties were influenced by bamboo face density. Comparing the properties to commercial wood based products, this panel could be used as wall/floor applications.

  8. Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels

    Science.gov (United States)

    Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

    2003-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

  9. Buckling optimisation of sandwich cylindrical panels

    Science.gov (United States)

    Abouhamzeh, M.; Sadighi, M.

    2016-06-01

    In this paper, the buckling load optimisation is performed on sandwich cylindrical panels. A finite element program is developed in MATLAB to solve the governing differential equations of the global buckling of the structure. In order to find the optimal solution, the genetic algorithm Toolbox in MATLAB is implemented. Verifications are made for both the buckling finite element code and also the results from the genetic algorithm by comparisons to the results available in literature. Sandwich cylindrical panels are optimised for the buckling strength with isotropic or orthotropic cores with different boundary conditions. Results are presented in terms of stacking sequence of fibers in the face sheets and core to face sheet thickness ratio.

  10. Utilization of Bamboo as Lightweight Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Suthon SRIVARO

    2016-05-01

    Full Text Available Lightweight sandwich panels consisting of bamboo faces and oil palm trunk core were manufactured using melamine urea formaldehyde with the resin content of 250 g/m2 (solid basis. The parameters examined were node and density of bamboo faces. Physical (board density, thickness swelling and water absorption and mechanical (modulus of elasticity and modulus of rupture properties of the sandwich board obtained were investigated and compared with other bamboo products and commercial wood based products. Result showed that this panel had better dimensional stability than those of other bamboo products but lower bending strength. Node of bamboo had no significant effect on any board properties examined. Most of board properties were influenced by bamboo face density. Comparing the properties to commercial wood based products, this panel could be used as wall/floor applications.

  11. A spiral antenna sandwiched by dielectric layers

    OpenAIRE

    Nakano, Hisamatsu; Ikeda, Masakazu; Hitosugi, Kazuo; Yamauchi, Junji

    2004-01-01

    An infinitesimally thin spiral antenna, sandwiched by bottom and top dielectric layers having the same relative permittivity, is analyzed under the condition that the dielectric layers are of finite extent and the antenna is backed by an infinite conducting plane. As the thickness of the top dielectric layer increases, the input impedance and axial ratio (AR) vary in an oscillatory fashion, with a period slightly larger than one-half of the guided wavelength of a wave propagating in an unboun...

  12. Self-healing sandwich composite structures

    Science.gov (United States)

    Fugon, D.; Chen, C.; Peters, K.

    2012-04-01

    Previous research demonstrated that a thin self-healing layer is effective in recovering partial sandwich composite performance after an impact event. Many studies have been conducted that show the possibility of using Fiber Bragg Grating (FBG) sensors to monitor the cure of a resin through strain and temperature monitoring. For this experiment, FBG sensors were used to monitor the curing process of a self-healing layer within a twelve-layer fiberglass laminate after impact. First, five self-healing sandwich composite specimens were manufactured. FBG sensors were embedded between the fiberglass and foam core. Then the fiberglass laminate was impacted with the use of a drop tower and the curing process was monitored. The collected data was used to compare the cure of the resin and fiberglass alone to the cure of the resin from a self-healing specimen. For the low viscosity resin system tested, these changes were not sufficiently large to identify different polymerization states in the resin as it cured. These results indicate that applying different resin systems might increase the efficiency of the self-healing in the sandwich composites.

  13. Mixed auxeticity of auxetic sandwich structures

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Teik-Cheng [SIM University, Singapore (Singapore)

    2012-07-15

    Previously, a sandwich structure in which the Poisson ratios of the core and facesheets possess opposite signs has been shown to exhibit overall conventional and auxetic behavior depending on the loading mode - axial loading or bending - for an intermediate range of relative core thickness. In addition to these two loading modes, sandwich structures in aerospace applications encounter torsional loads. In this paper, the effective Poisson's ratio for torsional loading is proposed. Results show that, depending on the loading mode and the relative core thickness, there can be up to four levels of overall auxeticity, namely (i) full auxeticity (FA) if the structure behaves as an auxetic structure under all three modes of loading, (ii) high auxeticity (HA) if the structure behaves as an auxetic structure in two of the loading modes, (iii) low auxeticity (LA) if the structure behaves as an auxetic structure in only one of the loading modes, and (iv) no auxeticity (NA) if the structure behaves as a conventional structure under all of the three loading modes. These results indicate that by selecting the Poisson's ratios and the thickness of the cores and facesheets, the sandwich structure can be made to respond differently under different external loading conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Combined Protein A and size exclusion high performance liquid chromatography for the single-step measurement of mAb, aggregates and host cell proteins.

    Science.gov (United States)

    Gjoka, Xhorxhi; Schofield, Mark; Cvetkovic, Aleksandar; Gantier, Rene

    2014-12-01

    Quantification of monoclonal antibody (mAb) monomer, mAb aggregates, and host cell proteins (HCPs) is critical for the optimization of the mAb production process. The present work describes a single high throughput analytical tool capable of tracking the concentration of mAb, mAb aggregate and HCPs in a growing cell culture batch. By combining two analytical HPLC methods, Protein A affinity and size-exclusion chromatography (SEC), it is possible to detect a relative increase or decrease in the concentration of all three entities simultaneously. A comparison of the combined Protein A-SEC assay to SEC alone was performed, demonstrating that it can be useful tool for the quantification of mAb monomer along with trending data for mAb aggregate and HCP. Furthermore, the study shows that the Protein A-SEC method is at least as accurate as other commonly used analytical methods such as ELISA and Bradford.

  15. L-asparaginase production by mangrove derived Bacillus cereus MAB5:optimization by response surface methodology

    Institute of Scientific and Technical Information of China (English)

    ThenmozhiC; SankarR; KaruppiahV; SampathkumarP

    2011-01-01

    Objective:To isolate marine bacteria, statistically optimize them for maximum asparaginase production. Methods:In the present study, statistically based experimental designs were applied to maximize the production of L-asparaginase from bacterial strain of Bacillus cereus (B. cereus) MAB5 (HQ675025) isolated and identified by 16S rDNA sequencing from mangroves rhizosphere sediment. Results:Plackett-Barman design was used to identify the interactive effect of the eight variables viz. yeast extract, soyabean meal, glucose, magnesium sulphate, KH2PO4, wood chips, aspargine and sodium chloride. All the variables are denoted as numerical factors and investigated at two widely spaced intervals designated as-1 (low level) and+1 (high level). The effect of individual parameters on L-asparaginase production was calculated. Soyabean meal, aspargine, wood chips and sodium chloride were found to be the significant among eight variables. The maximum amount of L-asparaginase produced (51.54 IU/mL) from the optimized medium containing soyabean meal (6.282 8 g/L), aspargine (5.5 g/L), wood chips (1.383 8 g/L) and NaCl (4.535 4 g/L). Conclusions:The study revealed that, it is useful to produce the maximum amount of L-asparaginase from B. cereus MAB5 for the treatment of various infections and diseases.

  16. Thermal conductivity of newspaper sandwiched aerated lightweight concrete panel

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Soon-Ching; Low, Kaw-Sai [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Wilayah Persekutuan (Malaysia)

    2010-12-15

    Investigation on the thermal conductivity of newspaper sandwiched aerated lightweight concrete (ALC) panels is the main purpose of this study. Various densities of ALC panels ranging from 1700, 1400 and 1100 kg/m{sup 3} with three different aerial intensities of newspaper sandwiched were produced. Investigation was limited to the effect of aerial intensity of newspaper sandwiched and the effect of density of ALC on thermal conductivity. It is found that the thermal conductivity of newspaper sandwiched ALC panels reduced remarkably compared to control ALC panels. The reduction was recorded at 18.0%, 21.8% and 20.7% correspond to densities of 1700, 1400 and 1100 kg/m{sup 3} with just a mere 0.05 g/cm{sup 2} aerial intensity of newspaper sandwiched. Newspaper sandwiched has a significant impact on the performance of thermal conductivity of ALC panels based on regression analysis. (author)

  17. Design Analysis of the Mixed Mode Bending Sandwich Specimen

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    A design analysis of the mixed mode bending (MMB) sandwich specimen for face–core interface fracture characterization is presented. An analysis of the competing failure modes in the foam cored sandwich specimens is performed in order to achieve face–core debond fracture prior to other failure modes....... The analysis facilitates selection of the appropriate geometry for the MMB sandwich specimen to promote debond failure. An experimental study is performed using MMB sandwich specimens with a H100 PVC foam core and E-glass–polyester faces. The results reveal that debond propagation is successfully achieved...... for the chosen geometries and mixed mode loading conditions....

  18. Influence of plywood grain direction on sandwich panel bending properties

    OpenAIRE

    Jaroslav Kljak; Mladen Brezović; Alan Antonović

    2009-01-01

    This paper investigates the influence of plywood grain direction on bending properties of a sandwich panel, as well as on stress distribution in each layer. Experimental sandwich panels (tnom= 29 mm) were made of two three-ply plywood panels and a rigid PVC core between them. Grain directions of plywood panels were between 0° and 90°, continuously raised by 15°. Seven models of sandwich panels were made. Bending properties of a sandwich panel was determined by three point bending method and s...

  19. Buckling Analysis of Debonded Sandwich Panel Under Compression

    Science.gov (United States)

    Sleight, David W.; Wang, John T.

    1995-01-01

    A sandwich panel with initial through-the-width debonds is analyzed to study the buckling of its faceskin when subject to an in-plane compressive load. The debonded faceskin is modeled as a beam on a Winkler elastic foundation in which the springs of the elastic foundation represent the sandwich foam. The Rayleigh-Ritz and finite-difference methods are used to predict the critical buckling load for various debond lengths and stiffnesses of the sandwich foam. The accuracy of the methods is assessed with a plane-strain finite-element analysis. Results indicate that the elastic foundation approach underpredicts buckling loads for sandwich panels with isotropic foam cores.

  20. Analytical determination of the ultimate strength of sandwich beams

    Science.gov (United States)

    Theotokoglou, Efstathios E.

    1996-09-01

    An analytical determination of the ultimate strength of a typical GRP/PVC sandwich beam has been performed. These beams represent common building practise in marine applications. Equations describing the behaviour of a sandwich panel under beam loading and various failure modes have been developed. The method has been applied to predict the ultimate load for a simple supported sandwich beam. The critical loads have been compared with those from the experimental investigation of a typical bulkhead-to-hull GRP/PVC sandwich T-joint under pull out forces.

  1. Elastic constants for superplastically formed/diffusion-bonded sandwich structures

    Science.gov (United States)

    Ko, W. L.

    1979-01-01

    Formulae and the associated graphs are presented for contrasting the effective elastic constants for a superplastically formed/diffusion-bonded (SPF/DB) corrugated sandwich core and a honeycomb sandwich core. The results used in the comparison of the structural properties of the two types of sandwich cores are under conditions of equal sandwich density. It was found that the stiffness in the thickness direction of the optimum SPF/DB corrugated core (i.e., triangular truss core) was lower than that of the honeycomb core, and that the former had higher transverse shear stiffness than the latter.

  2. Monoclonal antibody proteomics: use of antibody mimotope displaying phages and the relevant synthetic peptides for mAb scouting.

    Science.gov (United States)

    Hajdú, István; Flachner, Beáta; Bognár, Melinda; Végh, Barbara M; Dobi, Krisztina; Lőrincz, Zsolt; Lázár, József; Cseh, Sándor; Takács, László; Kurucz, István

    2014-08-01

    Monoclonal antibody proteomics uses nascent libraries or cloned (Plasmascan™, QuantiPlasma™) libraries of mAbs that react with individual epitopes of proteins in the human plasma. At the initial phase of library creation, cognate protein antigen and the epitope interacting with the antibodies are not known. Scouting for monoclonal antibodies (mAbs) with the best binding characteristics is of high importance for mAb based biomarker assay development. However, in the absence of the identity of the cognate antigen the task represents a challenge. We combined phage display, and surface plasmon resonance (Biacore) experiments to test whether specific phages and the respective mimotope peptides obtained from large scale studies are applicable to determine key features of antibodies for scouting. We show here that mAb captured phage-mimotope heterogeneity that is the diversity of the selected peptide sequences, is inversely correlated with an important binding descriptor; the off-rate of the antibodies and that represents clues for driving the selection of useful mAbs for biomarker assay development. Carefully chosen synthetic mimotope peptides are suitable for specificity testing in competitive assays using the target proteome, in our case the human plasma.

  3. Immunohistochemical Analysis Using Antipodocalyxin Monoclonal Antibody PcMab-47 Demonstrates Podocalyxin Expression in Oral Squamous Cell Carcinomas.

    Science.gov (United States)

    Itai, Shunsuke; Yamada, Shinji; Kaneko, Mika K; Harada, Hiroyuki; Kato, Yukinari

    2017-09-05

    Podocalyxin is a CD34-related type I transmembrane protein that is highly glycosylated with N-glycan, O-glycan, and keratan sulfate. Podocalyxin was originally found in the podocytes of rat kidney and is reportedly expressed in many types of tumors, including brain tumors, colorectal cancers, and breast cancers. Overexpression of podocalyxin is an independent predictor of progression, metastasis, and poor outcome. We recently immunized mice with recombinant human podocalyxin, which was produced using LN229 glioblastoma cells, and produced a novel antipodocalyxin monoclonal antibody (mAb), PcMab-47, which reacts with endogenous podocalyxin-expressing cancer cell lines and normal cell lines independent of glycosylation in Western blot, flow cytometry, and immunohistochemical analyses. In this study, we performed immunohistochemical analysis against oral cancers using PcMab-47. PcMab-47-stained oral squamous cell carcinoma cells in a cytoplasmic pattern and detected 26/38 (68.4%) of oral squamous cell carcinoma cells on tissue microarrays. These results indicate that PcMab-47 is useful in detecting podocalyxin of oral cancers for immunohistochemical analysis.

  4. A double-sandwich ELISA for identification of monoclonal antibodies suitable for sandwich immunoassays

    Science.gov (United States)

    The sandwich immunoassay (sIA) is an invaluable technique for concentrating, detecting, and quantifying target antigens. The two critical components required are a capture antibody and a detection antibody, each binding a different epitope on the target antigen. The specific antibodies incorporated...

  5. On curves on sandwiched surface singularities

    OpenAIRE

    Fernandez-Sanchez, Jesus

    2007-01-01

    Fixed a point O on a non-singular surface S and a complete mO-primary ideal I in its local ring, the curves on the surface X obtained by blowing-up I are studied in terms of the base points of I. Criteria for the principality of these curves are obtained. New formulas for their multiplicity, intersection numbers and order of singularity at the singularities of X are given. The semigroup of branches going through a sandwiched singularity is effectively determined, too.

  6. Failure modes of composite sandwich beams

    Directory of Open Access Journals (Sweden)

    Gdoutos E.

    2008-01-01

    Full Text Available A thorough investigation of failure behavior of composite sandwich beams under three-and four-point bending was undertaken. The beams were made of unidirectional carbon/epoxy facings and a PVC closed-cell foam core. The constituent materials were fully characterized and in the case of the foam core, failure envelopes were developed for general two-dimensional states of stress. Various failure modes including facing wrinkling, indentation failure and core failure were observed and compared with analytical predictions. The initiation, propagation and interaction of failure modes depend on the type of loading, constituent material properties and geometrical dimensions.

  7. Recent trends in aluminum foam sandwich technology

    Energy Technology Data Exchange (ETDEWEB)

    Banhart, John [TU Berlin, Materials Science and Technology, Hardenbergstr. 36, 10623 Berlin (Germany); Helmholtz-Centre Berlin, Hahn-Meitner-Platz, 14109 Berlin (Germany); Seeliger, Hans-Wolfgang [Pohltec Metalfoam GmbH, Robert-Bosch-Str. 6D, 50769 Koeln (Germany)

    2012-12-15

    We review the status of aluminum foam sandwich (AFS) technology and discuss both recent improvements of foaming technology and current application strategies. It is concluded that the quality of foams has improved in the past years but the costs are still very much the same. This is why applications in which metal foams have more than one function are more likely to be economically viable. The examples presented include electromagnetic shielding, carrier plates for mirrors, cooking equipment, architectural panels, and blast protection. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Expression and purification of Ctomp2aa167-aa434 and preparation of its mAb

    Institute of Scientific and Technical Information of China (English)

    JIAN HONG ZUO; LI ZHI TAN; CHAO QUN CHEN; NING ZHENG DONG; XIA BAI; CHANG GENG RUAN

    2006-01-01

    Chlamydia trachomatis outer membrane protein 2 (Ctomp2) is a major immunogen in chlamydial infections and a highly genus-conserved structural protein of all Chlamydia species. To purify the protein and to prepare monoclonal antibodies (mAbs) against it, the recombinant protein was induced by IPTG, which was confirmed by SDS-PAGE and purified by means of a Ni2+ -charged resin column. The denatured protein was refolded in the GSH-GSSH buffer gradually and identified by Western blotting. Then the BALB/c mice were immunized with the recombinant protein to prepare the mAb against Ctomp2. The obtained mAbs were characterized. Genital specimens were tested with indirect ELISA mostly made of the mAb and cell culture in 84 patients with genital symptoms. The results showed that high-level expression of the recombinant protein was achieved, which existed as inclusion body and amounted to 38 % of total bacterium protein. A mAb against Ctomp2 was obtained. It belongs to IgG 2b. The titers were as high as 1:40 000. The Western blotting showed that the mAb only reacted with the recombinant protein. It had no crossing reactions against E. coli, N. gonorhoea, M.hominis, U. urealyticum and M. penetrans. It had high specifity. In comparison with gold standard test-cell culture, the sensitivities, specificities, positive predictive values and negative predictive values of indirect ELISA were 95.24%, 100%, 100% and 98.44%, respectively. The above-mentioned research work contributed not only to the further study of the structure and function of this protein, but also to the establishment of the method for its clinical application, for it had not been reported before.

  9. P3 mAb: An Immunogenic Anti-NeuGcGM3 Antibody with Unusual Immunoregulatory Properties

    OpenAIRE

    Martínez, Darel; Rodríguez, Nely; Griñán, Tania; Rondón, Teresa; Vázquez, Ana María; Pérez, Rolando; Hernández, Ana María

    2012-01-01

    P3 is a murine IgM mAb that recognize N-glycosylated gangliosides, sulfatides, and antigens expressed in melanoma, breast, and lung human tumors. This antibody has the ability to trigger an IgG antibody response in the syngeneic BALB/c model, even when it is administered in the absence of adjuvant or carrier protein. The mechanism by which the P3 mAb, a self-immunoglobulin, induce this immune response in the absence of co-stimulatory or classical danger signals is still unknown. In the presen...

  10. P3 mAb: an immunogenic anti-NeuGcGM3 antibody with unusual immunoregulatory properties.

    OpenAIRE

    Darel eMartínez; Nely eRodríguez; Tania eGriñán; Teresa eRondón; Ana María Vázquez1; Rolando ePérez; Ana María eHernández

    2012-01-01

    P3 is a murine IgM mAb that recognize N-glycolilated gangliosides, sulphatides and antigens expressed in melanoma, breast and lung human tumors. This antibody has the ability to trigger an IgG antibody response in the syngeneic BALB/c model, even when it is administered in the absence of adjuvant or carrier protein. The mechanism by which the P3 mAb, a self immunoglobuline, induce this immune response in the absence of co-stimulatory or classical danger signals is still unknown. In the presen...

  11. Dynamic Failure of Composite and Sandwich Structures

    CERN Document Server

    Abrate, Serge; Rajapakse, Yapa D S

    2013-01-01

    This book presents a broad view of the current state of the art regarding the dynamic response of composite and sandwich structures subjected to impacts and explosions. Each chapter combines a thorough assessment of the literature with original contributions made by the authors.  The first section deals with fluid-structure interactions in marine structures.  The first chapter focuses on hull slamming and particularly cases in which the deformation of the structure affects the motion of the fluid during the water entry of flexible hulls. Chapter 2 presents an extensive series of tests underwater and in the air to determine the effects of explosions on composite and sandwich structures.  Full-scale structures were subjected to significant explosive charges, and such results are extremely rare in the open literature.  Chapter 3 describes a simple geometrical theory of diffraction for describing the interaction of an underwater blast wave with submerged structures. The second section addresses the problem of...

  12. Sandwich materials for wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Thybo Thomsen, O. [Aalborg Univ., Dept. of Mechanical Engineering, Aalborg (Denmark)

    2006-07-01

    Wind turbine blades are being manufactured using polymer matrix composite materials (PMC), in a combination of monolithic (single skin) and sandwich composites. Present day designs are mainly based on glass fibre reinforced composites (GFRP), but for very large blades carbon fibre reinforced composites (CFRP) are being used increasingly, in addition to GFRP by several manufacturers to reduce the weight. The size of wind turbines have increased significantly over the last 25 years, and this trend is expected to continue in the future. Thus, it is anticipated that wind turbines with a rated power output in the range of 8-10 MW and a rotor diameter about 170-180 m will be developed and installed within the next 10-15 years. The paper presents an overview of current day design principles and materials technology applied for wind turbine blades, and it highlights the limitations and important design issues to be addressed for up-scaling of wind turbine blades from the current maximum length in excess of 61 m to blade lengths in the vicinity of 90 m as envisaged for future very large wind turbines. In particular, the paper discusses the potential advantages and challenges of applying sandwich type construction to a larger extent than is currently being practiced for the load carrying parts of wind turbine blades. (au)

  13. Quantum radiation from a sandwich black hole

    Science.gov (United States)

    Frolov, Valeri P.; Zelnikov, Andrei

    2017-02-01

    We discuss quantum radiation of a massless scalar field from a spherically symmetric nonsingular black hole with a finite lifetime. Namely, we discuss a sandwich black-hole model, where a black hole is originally created by a collapse of a null shell of mass M , and later, after some time Δ V , it is disrupted by the collapse of the other shell with negative mass -M . We assume that between the shells the metric is static and either coincides with the Hayward metric or with a special generalization of it. We show that in both cases for a sufficiently large parameter Δ V the radiation after the formation of the black hole practically coincides with the Hawking result. We also calculate the radiation, emitted from the black hole interior. This radiation contains a peak at the moment when the second shell intersects the inner horizon. In the standard sandwich metric (with the Hayward interior) this outburst of energy is exponentially large. In the modified metric, which includes an additional nontrivial redshift parameter, this exponent is suppressed. This is a result of a significant decrease of the surface gravity of the inner horizon in the latter case. We discuss possible consequences of this result in the context of the self-consistency requirement for nonsingular models with quantum radiation.

  14. Fracture Analysis of Debonded Sandwich Columns Under Axial Compression

    DEFF Research Database (Denmark)

    May, A.; Avilés, F.; Berggreen, Christian

    A sandwich structure consists of two strong and stiff face sheets bonded to a weak low density core. The large separation between the face sheets provides increased bending rigidity and strength at low weight cost. Thus, sandwich structures frequently present better mechanical properties than mon...

  15. Practical Instruction in Tissue Culture and Cytogenetics for Sandwich Students.

    Science.gov (United States)

    Williams, D. C.; Bishun, N. P.

    1973-01-01

    Describes the training and practical techniques taught to students involved in a sandwich course at the Tissue Culture and Cytogenetics Unit of the Marie Curie Memorial Foundation, Surrey, England. Students spend a minimum of six months involved in the sandwich course before returning to university for a final academic year. (JR)

  16. Query processing of pre-partitioned data using Sandwich Operators

    NARCIS (Netherlands)

    Baumann, S.; Boncz, P.A.; Sattler, K.-U.

    2012-01-01

    In this paper we present the Sandwich Operators, an elegant approach to exploit pre-sorting or pre-grouping from clustered storage schemes in operators such as Aggregation/Grouping, HashJoin, and Sort of a database management system. Thereby, each of these operator types is "sandwiched" by two new o

  17. Tailoring Sandwich Face/Core Interfaces for Improved Damage Tolerance

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    Various modifications of the face/core interface in foam core sandwich specimens are examined in a series of two papers. This paper constitutes part I and describes the finite element analysis of a sandwich test specimen, i.e. a DCB specimen loaded by uneven bending moments (DCB-UBM). Using...

  18. Tailoring Sandwich Face/Core Interfaces for Improved Damage Tolerance

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    A face/core debond in a sandwich structure may propagate in the interface or kink into either the face or core. It is found that certain modifications of the face/core interface region influence the kinking behavior, which is studied experimentally in the present paper. A sandwich double cantilever...

  19. Fracture Analysis of Debonded Sandwich Columns Under Axial Compression

    DEFF Research Database (Denmark)

    May, A.; Avilés, F.; Berggreen, Christian

    A sandwich structure consists of two strong and stiff face sheets bonded to a weak low density core. The large separation between the face sheets provides increased bending rigidity and strength at low weight cost. Thus, sandwich structures frequently present better mechanical properties than mon...

  20. Thick Plate Homogenization of Sandwich Panels Including Folded Cellular Cores

    OpenAIRE

    LEBEE, Arthur; Sab, Karam

    2011-01-01

    In the present work, we provide the Bending-Gradient homogenization scheme and apply it to a sandwich panel including the chevron pattern. It turns out that the shear forces stiffness of the sandwich panel is strongly influenced by a skin distortion phenomenon which cannot be neglected in conventional design.

  1. Finite Element Modeling of the Buckling Response of Sandwich Panels

    Science.gov (United States)

    Rose, Cheryl A.; Moore, David F.; Knight, Norman F., Jr.; Rankin, Charles C.

    2002-01-01

    A comparative study of different modeling approaches for predicting sandwich panel buckling response is described. The study considers sandwich panels with anisotropic face sheets and a very thick core. Results from conventional analytical solutions for sandwich panel overall buckling and face-sheet-wrinkling type modes are compared with solutions obtained using different finite element modeling approaches. Finite element solutions are obtained using layered shell element models, with and without transverse shear flexibility, layered shell/solid element models, with shell elements for the face sheets and solid elements for the core, and sandwich models using a recently developed specialty sandwich element. Convergence characteristics of the shell/solid and sandwich element modeling approaches with respect to in-plane and through-the-thickness discretization, are demonstrated. Results of the study indicate that the specialty sandwich element provides an accurate and effective modeling approach for predicting both overall and localized sandwich panel buckling response. Furthermore, results indicate that anisotropy of the face sheets, along with the ratio of principle elastic moduli, affect the buckling response and these effects may not be represented accurately by analytical solutions. Modeling recommendations are also provided.

  2. Optimization of sandwich composites fuselages under flight loads

    NARCIS (Netherlands)

    Yan, C.; Bergsma, O.; Koussios, S.; Zu, L.; Beukers, A.

    2010-01-01

    The sandwich composites fuselages appear to be a promising choice for the future aircrafts because of their structural efficiency and functional integration advantages. However, the design of sandwich composites is more complex than other structures because of many involved variables. In this paper,

  3. Design and manufacturing of bio-based sandwich structures

    CSIR Research Space (South Africa)

    John, Maya J

    2017-03-01

    Full Text Available The aim of this chapter is to discuss the design and manufacturing of bio-based sandwich structures. As the economic advantages of weight reduction have become mandatory for many advanced industries, bio-based sandwich panels have emerged...

  4. Development, testing, and numerical modeling of a foam sandwich biocomposite

    Science.gov (United States)

    Chachra, Ricky

    This study develops a novel sandwich composite material using plant based materials for potential use in nonstructural building applications. The face sheets comprise woven hemp fabric and a sap based epoxy, while the core comprises castor oil based foam with waste rice hulls as reinforcement. Mechanical properties of the individual materials are tested in uniaxial compression and tension for the foam and hemp, respectively. The sandwich composite is tested in 3 point bending. Flexural results are compared to a finite element model developed in the commercial software Abaqus, and the validated model is then used to investigate alternate sandwich geometries. Sandwich model responses are compared to existing standards for nonstructural building panels, showing that the novel material is roughly half the strength of equally thick drywall. When space limitations are not an issue, a double thickness sandwich biocomposite is found to be a structurally acceptable replacement for standard gypsum drywall.

  5. Isocitrate dehydrogenase 2 mutation is a frequent event in osteosarcoma detected by a multi-specific monoclonal antibody MsMab-1.

    Science.gov (United States)

    Liu, Xing; Kato, Yukinari; Kaneko, Mika Kato; Sugawara, Masato; Ogasawara, Satoshi; Tsujimoto, Yuta; Naganuma, Yasushi; Yamakawa, Mitsunori; Tsuchiya, Takashi; Takagi, Michiaki

    2013-12-01

    Somatic mutations of isocitrate dehydrogenase (IDH) 1 and IDH2 occur in gliomas, acute myeloid leukemia, and cartilaginous tumors. Somatic mosaic IDH1/2 mutations are also reported in Ollier disease and Maffucci syndrome, which are characterized by multiple central cartilaginous tumors. Although IDH1/2 mutation analysis against osteosarcoma has been performed in several studies, no IDH1/2 mutation has been reported. Herein, we newly report the IDH2-R172S mutation in three of 12 (25%) osteosarcoma patients, which was detected by direct DNA sequencing. No monoclonal antibody (mAb) has been reported against IDH2-R172S mutation. However, we demonstrate that the IDH2-R172S peptide was recognized by our established multi-specific anti-mutated IDH1/2 mAb, MsMab-1, in enzyme-linked immunosorbent assay. Western blot analysis revealed that MsMab-1 reacts with PA tag combined recombinant proteins of IDH2-R172S. Furthermore, MsMab-1 stained IDH2-R172S-expressing osteosarcoma tissues in immunohistochemistry. The MsMab-1 stained nine of 32 (28.1%) osteosarcomas in a tissue microarray. This report is the first describing IDH2 mutations in osteosarcoma, which can be detected by MsMab-1 mAb. Taken together, these results show that MsMab-1 can be anticipated for use in immunohistochemical determination of IDH1/2 mutation-bearing osteosarcoma.

  6. MAB21L2, a vertebrate member of the Male-abnormal 21 family, modulates BMP signaling and interacts with SMAD1

    Directory of Open Access Journals (Sweden)

    Longhi Renato

    2004-12-01

    Full Text Available Abstract Background Through in vivo loss-of-function studies, vertebrate members of the Male abnormal 21 (mab-21 gene family have been implicated in gastrulation, neural tube formation and eye morphogenesis. Despite mounting evidence of their considerable importance in development, the biochemical properties and nature of MAB-21 proteins have remained strikingly elusive. In addition, genetic studies conducted in C. elegans have established that in double mutants mab-21 is epistatic to genes encoding various members of a Transforming Growth Factor beta (TGF-beta signaling pathway involved in the formation of male-specific sensory organs. Results Through a gain-of-function approach, we analyze the interaction of Mab21l2 with a TGF-beta signaling pathway in early vertebrate development. We show that the vertebrate mab-21 homolog Mab21l2 antagonizes the effects of Bone Morphogenetic Protein 4 (BMP4 overexpression in vivo, rescuing the dorsal axis and restoring wild-type distribution of Chordin and Xvent2 transcripts in Xenopus gastrulae. We show that MAB21L2 immunoprecipitates in vivo with the BMP4 effector SMAD1, whilst in vitro it binds SMAD1 and the SMAD1-SMAD4 complex. Finally, when targeted to an heterologous promoter, MAB21L2 acts as a transcriptional repressor. Conclusions Our results provide the first biochemical and cellular foundation for future functional studies of mab-21 genes in normal neural development and its pathological disturbances.

  7. ING-1(heMAb, a Monoclonal Antibody to Epithelial Cell Adhesion Molecule, Inhibits Tumor Metastases in a Murine Cancer Model

    Directory of Open Access Journals (Sweden)

    Harry H. Ruan

    2003-11-01

    Full Text Available ING-1(heMAb, a human-engineered monoclonal antibody (MAb that specifically targets the epithelial cell adhesion molecule (Ep-CAM, kills adenocarcinoma cells in vitro and inhibits tumor growth in vivo. In the current study, we evaluated the efficacy of ING-1(heMAb in a murine model of cancer metastases. Mice received intravenous dosing of 1 mg/kg ING-1(heMAb, twice a week, starting on day 2 or day 5. A negative control group received 1 mg/kg human immunoglobulin G with the same dose frequency starting on day 2. A positive control group received weekly 100 mg/kg 54lurouracil/leucovorin starting on day 2. ING-1(heMAb/day 2 treatment significantly reduced both the number of visible tumor nodules in body cavities (P < .01 and the number of metastases on lung surfaces (P < .005. The treatment also resulted in a 91% reduction of micrometastases in lung tissues (P <.0001. Delaying ING-1(heMAb treatment until day 5 caused 54% reduction in micrometastases (P <.005. Our results indicate that a number of parameters, including treatment starting day, dose level, and dose frequency, are critical in achieving the optimal efficacy of ING-1(heMAb. We conclude that ING-1(heMAb effectively reduced tumor metastases in a murine cancer model. Immunotherapy with ING-1(heMAb may be beneficial in treating human metastatic diseases.

  8. EPITOPE MAPPING OF SCLC-CLUSTER-2 MABS AND GENERATION OF ANTIBODIES DIRECTED AGAINST NEW EGP-2 EPITOPES

    NARCIS (Netherlands)

    HELFRICH, W; KONING, PW; THE, TH; DELEIJ, L

    1994-01-01

    Western blot analysis proved that all cluster-2 MAbs recognize identical or overlapping disulfide-bond-dependent epitopes, indicating the presence of a disulfide-bond-stabilized EGP-2 domain carrying highly immunodominant non-linear epitopes. The apparent immunodominance of this domain makes it diff

  9. Standard Test Method for Sandwich Corrosion Test

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method defines the procedure for evaluating the corrosivity of aircraft maintenance chemicals, when present between faying surfaces (sandwich) of aluminum alloys commonly used for aircraft structures. This test method is intended to be used in the qualification and approval of compounds employed in aircraft maintenance operations. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information. 1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements appear in Section 9.

  10. Nanoparticle organization in sandwiched polymer brushes.

    Science.gov (United States)

    Curk, Tine; Martinez-Veracoechea, Francisco J; Frenkel, Daan; Dobnikar, Jure

    2014-05-14

    The organization of nanoparticles inside grafted polymer layers is governed by the interplay of polymer-induced entropic interactions and the action of externally applied fields. Earlier work had shown that strong external forces can drive the formation of colloidal structures in polymer brushes. Here we show that external fields are not essential to obtain such colloidal patterns: we report Monte Carlo and molecular dynamics simulations that demonstrate that ordered structures can be achieved by compressing a "sandwich" of two grafted polymer layers, or by squeezing a coated nanotube, with nanoparticles in between. We show that the pattern formation can be efficiently controlled by the applied pressure, while the characteristic length-scale, that is, the typical width of the patterns, is sensitive to the length of the polymers. Based on the results of the simulations, we derive an approximate equation of state for nanosandwiches.

  11. Development of an ELP-Z based mAb affinity precipitation process using scaled-down filtration techniques.

    Science.gov (United States)

    Sheth, Rahul D; Bhut, Bharat V; Jin, Mi; Li, Zhengjian; Chen, Wilfred; Cramer, Steven M

    2014-12-20

    In this work, a proof of concept elastin-like polypeptide-Z domain fusion (ELP-Z) based monoclonal antibody (mAb) affinity precipitation process is developed using scaled-down filtration techniques. Tangential flow filtration (TFF) is examined for the recovery of ELP-Z-mAb precipitates formed during the mAb binding step and the ELP-Z precipitates formed during the mAb elution step. TFF results in complete precipitate recovery during both stages of the process and high host cell protein and DNA impurity clearance after diafiltration. Total recycle TFF experiments are then employed to determine permeate flux as a function of the precipitate concentration for both stages of the process. While the ELP-Z-mAb precipitate recovery step resulted in high permeate flux (550-600L/m(2)/h/bar), the ELP-Z precipitates are shown to severely foul the TFF membrane, causing rapid flux decay. Confocal microscopy of the ELP-Z-mAb and ELP-Z precipitates suggests significant differences in the morphology and the kinetics of formation of these precipitates, which is likely responsible for their different behavior during TFF. Finally, an alternative normal flow filtration strategy is developed for the ELP-Z precipitate recovery step during mAb elution, using a combination of 5μm and a 0.45/0.2μm filters. Using this approach, the ELP-Z precipitates are separated from the final mAb elution pool at high volumetric throughputs and high ELP-Z recovery (96%) is obtained after resolubilization from the filter. This study demonstrates that the ELP-Z affinity precipitation process can be readily scaled up using conventional membrane processing.

  12. Authorized manufacturing changes for therapeutic monoclonal antibodies (mAbs) in European Public Assessment Report (EPAR) documents.

    Science.gov (United States)

    Vezér, Balázs; Buzás, Zsuzsanna; Sebeszta, Miklós; Zrubka, Zsombor

    2016-05-01

    Background The quality of biologicals, including biosimilars, is subject to change as a result of manufacturing process modifications following initial authorization. It is important that such product changes have no adverse impact on product efficacy or safety, including immunogenicity. Objectives The aim of this study was to investigate the number and types of manufacturing changes for originator mAbs (the reference for the comparability exercise to confirm biosimilarity) according to European Public Assessment Report (EPAR) documentation and to ascertain the level of risk these changes might impart. The extensive body of evidence contained in the EPAR documents can help support the EMA during the EC marketing authorization approval process for biosimilars, since it provides a broad base of scientific experience. Research designs and methods For EPAR-listed mAbs, details of all changes listed chronologically in the EPAR were evaluated and described. Based on these descriptions the manufacturing changes can be categorized by risk status (low, moderate or high). Results Entries for 29 mAbs with publicly available EPAR reports were reviewed. These contained details of 404 manufacturing changes authorized by the European Medicines Agency (EMA): 22 were categorized as high risk, 286 as moderate risk and 96 as low risk manufacturing changes. A limitation of this analysis is that it only summarizes publicly available data from EPAR documents. Conclusions Manufacturing change data indicate that the EMA has significant experience of process changes for originator mAbs, and the impact they may have on the efficacy and safety of biologicals. This experience will be useful in biosimilar product development to ensure adherence to sound scientific principles. Compared with the established manufacturing process for a reference product, the production of biosimilars will usually be different. Consequently, in addition to a comprehensive comparative functional and physicochemical

  13. Development and Mechanical Behavior of FML/Aluminium Foam Sandwiches

    Science.gov (United States)

    Baştürk, S. B.; Tanoğlu, M.

    2013-10-01

    In this study, the Fiber-Metal Laminates (FMLs) containing glass fiber reinforced polypropylene (GFPP) and aluminum (Al) sheet were consolidated with Al foam cores for preparing the sandwich panels. The aim of this article is the comparison of the flexural properties of FML/Al foam sandwich panels bonded with various surface modification approaches (silane treatment and combination of silane treatment with polypropylene (PP) based film addition). The FML/foam sandwich systems were fabricated by laminating the components in a mould at 200 °C under 1.5 MPa pressure. The energy absorbtion capacities and flexural mechanical properties of the prepared sandwich systems were evaluated by mechanical tests. Experiments were performed on samples of varying foam thicknesses (8, 20 and 30 mm). The bonding among the sandwich components were achieved by various surface modification techniques. The Al sheet/Al foam sandwiches were also consolidated by bonding the components with an epoxy adhesive to reveal the effect of GFPP on the flexural performance of the sandwich structures.

  14. [Rituximab (MabThera)--a new biological medicine in rheumatoid arthritis therapy].

    Science.gov (United States)

    Nemec, P

    2007-11-01

    Rheumatoid arthritis (RA) is a serious, chronic, inflammatory disorder that damages the joints. The chronic destructive process causes pain to patients with RA and leads to the development of permanent disability. At present, great emphasis is placed on timely and effective therapy for RA, which is able to halt or slow the development of the disorder. At present we do not have any means of curing RA, the main objective for treatment is to induce remission of the disorder and prevent structural damage to the joints and the development of permanent disability. The relatively frequent failure of disease modifying medications (DMARDs) lead to efforts to find new resources for the treatment of RA. So called biological medicines were recently introduced into therapeutic use. These were mainly TNFalpha blockers. Experience has shown that approximately a third of patients with RA do not respond even to treatment with such medicines. Rituximab (MabThera), a monoclonal antibody against CD20 positive B-lymphocytes, is a new biological medicine approved for RA therapy. It represents a new hope for patients with active RA, for whom earlier therapy with TNFa blockers has failed.

  15. MAB_3551c encodes the primary triacylglycerol synthase involved in lipid accumulation in Mycobacterium abscessus.

    Science.gov (United States)

    Viljoen, Albertus; Blaise, Mickael; de Chastellier, Chantal; Kremer, Laurent

    2016-11-01

    Slow growing pathogenic mycobacteria utilize host-derived lipids and accumulate large amounts of triacylglycerol (TAG) in the form of intracytoplasmic lipid inclusions (ILI), serving as a source of carbon and energy during prolonged infection. Mycobacterium abscessus is an emerging and rapidly growing species capable to induce severe and chronic pulmonary infections. However, whether M. abscessus, like Mycobacterium tuberculosis, possesses the machinery to acquire and store host lipids, remains unaddressed. Herein, we aimed at deciphering the contribution of the seven putative M. abscessus TAG synthases (Tgs) in TAG synthesis/accumulation thanks to a combination of genetic and biochemical techniques and a well-defined foamy macrophage (FM) model along with electron microscopy. Targeted gene deletion and functional complementation studies identified the MAB_3551c product, Tgs1, as the major Tgs involved in TAG production. Tgs1 exhibits a preference for long acyl-CoA substrates and site-directed mutagenesis demonstrated that His144 and Gln145 are essential for enzymatic activity. Importantly, in the lipid-rich intracellular context of FM, M. abscessus formed large ILI in a Tgs1-dependent manner. This supports the ability of M. abscessus to assimilate host lipids and the crucial role of Tgs1 in intramycobacterial TAG production, which may represent important mechanisms for long-term storage of a rich energy supply.

  16. Wave propagation in sandwich panels with a poroelastic core.

    Science.gov (United States)

    Liu, Hao; Finnveden, Svante; Barbagallo, Mathias; Arteaga, Ines Lopez

    2014-05-01

    Wave propagation in sandwich panels with a poroelastic core, which is modeled by Biot's theory, is investigated using the waveguide finite element method. A waveguide poroelastic element is developed based on a displacement-pressure weak form. The dispersion curves of the sandwich panel are first identified as propagating or evanescent waves by varying the damping in the panel, and wave characteristics are analyzed by examining their motions. The energy distributions are calculated to identify the dominant motions. Simplified analytical models are also devised to show the main physics of the corresponding waves. This wave propagation analysis provides insight into the vibro-acoustic behavior of sandwich panels lined with elastic porous materials.

  17. A Debonded Sandwich Specimen Under Mixed Mode Bending (MMB)

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2008-01-01

    Face/core interface crack propagation in sandwich specimens is analyzed. A thorough analysis of the typical failure modes in sandwich composites was performed in order to design the MMB specimen to promote face/core debond fracture. Displacement, compliance and energy release rate expressions...... for the MMB specimen were derived from a superposition analysis. An experimental verification of the methodology proposed was performed using MMB sandwich specimens with H100 PVC foam core and E-glass/polyester non-crimp quadro-axial [0/45/90/-45]s DBLT-850 faces. Different mixed mode loadings were applied...

  18. Measuring Cohesive Laws for Interfaces in Sandwich Structures

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Sørensen, Bent F.; Berggreen, Carl Christian

    2006-01-01

    Extraction of cohesive laws are conducted for interfaces in sandwich structures. Separation between face and core are driven by pure bending moments applied to double cantilever beam (DCB) specimens. By varying the ratio between moments applied to the beams the test is conducted for different mode...... mixities. The sandwich specimens consists of glass fiber faces and Divinycell H200 foam core with a pre-crack between face and core made with teflon film. Arbitrary stiffening of the sandwich faces with steel bars adhered to the faces reduces rotations and ensures that the method is useable for a wide...

  19. A Debonded Sandwich Specimen Under Mixed Mode Bending (MMB)

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2008-01-01

    Face/core interface crack propagation in sandwich specimens is analyzed. A thorough analysis of the typical failure modes in sandwich composites was performed in order to design the MMB specimen to promote face/core debond fracture. Displacement, compliance and energy release rate expressions...... for the MMB specimen were derived from a superposition analysis. An experimental verification of the methodology proposed was performed using MMB sandwich specimens with H100 PVC foam core and E-glass/polyester non-crimp quadro-axial [0/45/90/-45]s DBLT-850 faces. Different mixed mode loadings were applied...

  20. Measuring Cohesive Laws for Interfaces in Sandwich Structures

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Sørensen, Bent F.; Berggreen, Carl Christian

    2006-01-01

    Extraction of cohesive laws are conducted for interfaces in sandwich structures. Separation between face and core are driven by pure bending moments applied to double cantilever beam (DCB) specimens. By varying the ratio between moments applied to the beams the test is conducted for different mode...... mixities. The sandwich specimens consists of glass fiber faces and Divinycell H200 foam core with a pre-crack between face and core made with teflon film. Arbitrary stiffening of the sandwich faces with steel bars adhered to the faces reduces rotations and ensures that the method is useable for a wide...

  1. Thermal behavior of a titanium honeycomb-core sandwich panel

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1991-01-01

    Finite element thermal stress analysis was performed on a rectangular titanium honecomb-core sandwich panel which is subjected to thermal load with a temperature gradient across its depth. The distributions of normal stresses in the face sheets and the face-sheet/sandwich-core interfacial shear stresses are presented. The thermal buckling of the heated face sheet was analyzed by assuming the face sheet to be resting on an elastic foundation representing the sandwich core. Thermal buckling curves and thermal buckling load surface are presented for setting the limit for temperature gradient across the panel depth.

  2. Sandwich Panel as a Structural Element of Overlap

    Directory of Open Access Journals (Sweden)

    Novikov Maxim

    2016-01-01

    Full Text Available This paper considers the issue of sandwich panels using as load-bearing structural elements. The comparison of deflections and critical failure loads were obtained by the results of the full-scale roof sandwich panels tests conducted by the company “Joris Ide” and the theoretical design, according to the calculation method described in Euronorms. Based on these results it was concluded that sandwich panels can be treated as a load-bearing structure only with more taught manufacturing requirements. Thus, the reduced spread of critical loads can be achieved.

  3. Successful mouse hepatocyte culture with sandwich collagen gel formation

    National Research Council Canada - National Science Library

    Choi, Hyun Jung; Choi, Dongho

    2013-01-01

    .... However, long-term cultures of functional hepatocytes are difficult to establish. To increase the longevity and maintain the differentiated functions of hepatocytes in primary culture, cells can be cultured in a sandwich configuration of collagen...

  4. Outcome of the TURP-TUVP sandwich procedure for minimally ...

    African Journals Online (AJOL)

    shanker

    TURP–TUVP sandwich procedure for the surgical treatment of BPH larger than 40cc in ... volume larger than 40cc had satisfactory patient safety profile and resulted in .... ment, nursing contact time, and duration of catheterization, besides.

  5. Sandwich-like reconstruction of anterior skull base defects

    Institute of Scientific and Technical Information of China (English)

    WANG Zhengmin; WANG Dehui

    2002-01-01

    @@ RESULTS From October, 1984 to October, 1998, 116 patients underwent transcranial or transcranial-facial approach for the resection of malignant or benign aggressive tumor, and sandwich-like repairs were performed for the anterior skull base defect.

  6. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    NARCIS (Netherlands)

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the ai

  7. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    NARCIS (Netherlands)

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the ai

  8. Observability and Controllability Analysis for Sandwich Systems with Backlash

    Directory of Open Access Journals (Sweden)

    Luo Na

    2015-12-01

    Full Text Available In this paper, an approach to analyze the observability and controllability of sandwich systems with backlash is proposed. In this method, a non-smooth state-space function is used to describe the sandwich systems with backlash which are also non-smooth non-linear systems. Then, a linearization method based on non-smooth optimization is proposed to derive a linearized state-space function to approximate the non-smooth sandwich systems within a bounded region around the equilibrium point that we are interested in. Afterwards, both observability and controllability matrices are constructed and the methods to analyze the observability as well as controllability of sandwich system with backlash are derived. Finally, numerical examples are presented to validate the proposed method.

  9. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    NARCIS (Netherlands)

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the

  10. Residual Strength Prediction of Debond Damaged Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian

    This presentation concerns theoretical and experimental prediction of crack propagation and residual strength of debond damaged sandwich panels. It is evident that in order to achieve highly optimised structures which are able to operate in a stochastic loading environment, damage tolerance...... propagation and initiation, as these mechanisms are governing for the overall failure load of the structure. Thus, this presentation will describe the development, validation and application of a FEM based numerical model for prediction of residual strength of damaged sandwich panels. The core......, but they are especially relevant for sandwich structures which by nature are highly optimised structures with a high number of possible damage scenarios and consequent failure mechanisms. A major challenge in estimation of structural integrity of damaged sandwich structures is modelling and prediction of crack...

  11. Fracture Characterization of Sandwich Face/Core Interfaces

    DEFF Research Database (Denmark)

    Manca, Marcello

    such result it is important to devise new experimental and analytical techniques to establish the multi-mode fracture characteristics of sandwich plate structures and accordingly develop methods to inhibit defect propagation. This thesis deals with characterization of fracture between face and core...... samples. A number of sandwich materials were tested (GFRP/foam cores and CFRP/Nomex) bothin static and fatigue. A linear elastic fracture mechanics model was used to determine the analyticalexpression of compliance which allowed to calculate automatically the crack length. In combination, a finite element...... types of sandwich samples atdifferent mode mixities and ΔG levels, and results in agreement with previous studies were obtained suggesting that the developed testing method is a reliable tool for the study of face/core interface debonded sandwich structures....

  12. Forced vibration of a shear thickening fluid sandwich beam

    Science.gov (United States)

    Wei, Minghai; Hu, Gang; Jin, Lu; Lin, Kun; Zou, Dujian

    2016-05-01

    The forced vibration of a sandwich beam integrating a shear thickening fluid (STF) core and with conductive skins subjected to a periodic excitation was investigated theoretically in this study. The rheological properties of the STF material including viscosity, plasticity, and elasticity may be changed under the periodic vibration, and hence they were considered. The governing equation of motion was derived based on the complex stiffness method and some key parameters were derived based on the Timoshenko beam theory. Effects of the excitation frequency, the excitation amplitude, the excitation location, and the skin/core thickness ratio on the nature frequency of the sandwich beam were investigated. It was found that the STF core has a significant effect on the dynamic property of the sandwich beam. Based on the findings, integrating the STF core in a sandwich beam can reduce the vibration of the beam.

  13. Verhulst and stochastic models for comparing mechanisms of MAb productivity in six CHO cell lines.

    Science.gov (United States)

    Shirsat, Nishikant; Avesh, Mohd; English, Niall J; Glennon, Brian; Al-Rubeai, Mohamed

    2016-08-01

    The present study validates previously published methodologies-stochastic and Verhulst-for modelling the growth and MAb productivity of six CHO cell lines grown in batch cultures. Cytometric and biochemical data were used to model growth and productivity. The stochastic explanatory models were developed to improve our understanding of the underlying mechanisms of growth and productivity, whereas the Verhulst mechanistic models were developed for their predictability. The parameters of the two sets of models were compared for their biological significance. The stochastic models, based on the cytometric data, indicated that the productivity mechanism is cell specific. However, as shown before, the modelling results indicated that G2 + ER indicate high productivity, while G1 + ER indicate low productivity, where G1 and G2 are the cell cycle phases and ER is Endoplasmic Reticulum. In all cell lines, growth proved to be inversely proportional to the cumulative G1 time (CG1T) for the G1 phase, whereas productivity was directly proportional to ER. Verhulst's rule, "the lower the intrinsic growth factor (r), the higher the growth (K)," did not hold for growth across all cell lines but held good for the cell lines with the same growth mechanism-i.e., r is cell specific. However, the Verhulst productivity rule, that productivity is inversely proportional to the intrinsic productivity factor (r x ), held well across all cell lines in spite of differences in their mechanisms for productivity-that is, r x is not cell specific. The productivity profile, as described by Verhulst's logistic model, is very similar to the Michaelis-Menten enzyme kinetic equation, suggesting that productivity is more likely enzymatic in nature. Comparison of the stochastic and Verhulst models indicated that CG1T in the cytometric data has the same significance as r, the intrinsic growth factor in the Verhulst models. The stochastic explanatory and the Verhulst logistic models can explain the

  14. Analysis of HLDA9 mAbs on plasmacytoid dendritic cells.

    Science.gov (United States)

    Cabezón, Raquel; Sintes, Jordi; Llinàs, Laia; Benitez-Ribas, Daniel

    2011-01-30

    Dendritic cells are a heterogeneous population of bone marrow derived leucocytes that play a crucial role in both pathogen recognition and the initiation of primary T cell immune responses. Plasmacytoid dendritic cells (pDCs), also known as natural interferon-producing cells, comprise one of two major human dendritic cell subsets that strongly influences immune balance. pDCs remain a poorly characterized subset. Several studies have suggested the existence of a close phenotypic and functional relationship between B-cells and pDCs. The surface reactivity of a panel of 96 monoclonal antibodies submitted to the ninth Human Leukocyte Differentiation Antigens workshop (HLDA9) B cell section was analyzed using pDCs as target cells. The results showed that eight of the mAbs reacted positively on pDCs: CD86, CD229, CD319, CD305, CD184, CD84, CD85g and FcɛRIa, confirming previously published reports. Interestingly, this study also revealed the expression of eight surface molecules not previously described on pDCs, including CD352(NTBA), CD272(BTLA), CD357(GITR), CD48, CD270(HVEM), Galectin-3, CD148, and CD361. The present report summarizes the expression of these molecules on freshly isolated pDCs. Significantly, we have identified several new molecules expressed by these intriguing cells, ones we believe will open new avenues for the study of pDC functionality and their role in human health and diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Identification of New Synthetic Cannabinoid ADB-CHMINACA (MAB-CHMINACA) Metabolites in Human Hepatocytes.

    Science.gov (United States)

    Carlier, Jeremy; Diao, Xingxing; Sempio, Cristina; Huestis, Marilyn A

    2017-03-01

    ADB-CHMINACA (MAB-CHMINACA) is a new synthetic cannabinoid with high potency and many reported adverse events and fatalities. The drug is currently scheduled in several countries in Europe and the USA. Analytical methods need to be developed to confirm ADB-CHMINACA intake for clinical and forensic programs. For many synthetic cannabinoids, parent compound is not detectable in biological samples after intake, making the detection of metabolites the only way to prove consumption. Therefore, detection of ADB-CHMINACA metabolites in biological specimens is critical. Since there are currently no published data on ADB-CHMINACA metabolism, we aimed to identify its major metabolites. Cryopreserved human hepatocytes were incubated with 10 μmol/L ADB-CHMINACA for 3 h. Incubations were analyzed with liquid chromatography on a biphenyl column, high resolution tandem mass spectrometry (orbitrap), and metabolite identification software. A reference standard of six commercially available potential metabolites was simultaneously analyzed under the same conditions to allow correct assignment of isomers. We detected ten major metabolites. Biotransformations mainly occurred at the cyclohexylmethyl tail of the compound, as also observed with structural analogs' metabolism. Minor reactions also occurred at the tert-butyl chain. Only two analytical standards of potential metabolites matched an actual metabolite detected in hepatocyte incubations. We recommend A9 (ADB-CHMINACA hydroxycyclohexylmethyl), A4 (ADB-CHMINACA 4″-hydroxycyclohexyl), and A6 (ADB-CHMINACA hydroxycyclohexylmethyl) as metabolite targets to document ADB-CHMINACA intake in clinical and forensic cases. Additionally, these results will guide analytical standard manufacturers to better provide suitable references for further studies on ADB-CHMINACA metabolism.

  16. Lightweight Sandwich Panel in Cold Stores and Refrigerated Warehouses

    OpenAIRE

    Chidom, Charles

    2013-01-01

    The use of sandwich panels has gained considerable recognition in the construction industry and more use of this composite structure is ever increasing. This study highlights and familiarizes the use of lightweight sandwich panel in refrigerated warehouses and cold storage facility and construction and the challenges such construction faces in warm climates considering the effects of thermal load. The study was commissioned by HAMK Sheet Metal Center, the steel research and development ce...

  17. Optimization of composite sandwich cover panels subjected to compressive loadings

    Science.gov (United States)

    Cruz, Juan R.

    1991-01-01

    An analysis and design method is presented for the design of composite sandwich cover panels that include the transverse shear effects and damage tolerance considerations. This method is incorporated into a sandwich optimization computer program entitled SANDOP. As a demonstration of its capabilities, SANDOP is used in the present study to design optimized composite sandwich cover panels for for transport aircraft wing applications. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to satisfy individual constraints. The results also indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and +/- 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density. Thus, core density should be chosen by criteria other than minimum weight (e.g., damage tolerance, ease of manufacture, etc.).

  18. Investigations into the fouling mechanism of parvovirus filters during filtration of freeze-thawed mAb drug substance solutions.

    Science.gov (United States)

    Barnard, James G; Kahn, David; Cetlin, David; Randolph, Theodore W; Carpenter, John F

    2014-03-01

    Filtration to remove viruses is one of the single most expensive steps in the production of mAb drug products. Therefore, virus filtration steps should be fully optimized, and any decline in flow rates warrants investigation into the causes of such membrane fouling. In the current study, it was found that freezing and thawing of a mAb bulk drug solution caused a substantial decrease in viral filter membrane flow rate. Freezing and thawing also caused formation of aggregates and particles across a broad size range, including particles that could be detected by microflow imaging (≥1 μm in size). However, removal of these particles offered little protection against flow rate decline during viral filtration. Further investigation revealed that trace amounts of aggregates (ca. 10⁻⁶ of the total mass of protein in solution) approximately 20-40 nm in size were primarily responsible for the observed membrane fouling.

  19. A study of structurally efficient graphite-thermoplastic trapezoidal-corrugation sandwich and semi-sandwich panels

    Science.gov (United States)

    Jegley, Dawn C.

    1993-01-01

    The structural efficiency of compression-loaded trapezoidal-corrugation sandwich and semi-sandwich composite panels is studied to determine their weight savings potential. Sandwich panels with two identical face sheets and a trapezoidal corrugated core between them, and semi-sandwich panels with a corrugation attached to a single skin are considered. An optimization code is used to find the minimum weight designs for critical compressive load levels ranging from 3,000 to 24,000 lb/in. Graphite-thermoplastic panels based on the optimal minimum weight designs were fabricated and tested. A finite-element analysis of several test specimens was also conducted. The results of the optimization study, the finite-element analysis, and the experiments are presented.

  20. Electronically asymmetric bis(porphyrin) sandwich complexes

    Energy Technology Data Exchange (ETDEWEB)

    Girolami, G.S.; Gorlin, P.A.; Suslick, K.S. [Univ. of Illinois, Urbana, IL (United States)

    1994-02-16

    Bis(porphyrin)metal(IV) complexes (M(porph){sub 2}) have been extensively studies in recent years due to their structural, chemical, and spectroscopic similarity to the {open_quotes}special pair{close_quotes} found in the reaction center of photosynthetic bacteria. Strong interactions arise in the bis(porphyrin) complexes due to the short inter-porphyrin separation (< 3 {angstrom}), which results in properties not seen in mono(porphyrin) analogs. For example, the bis(porphyrin) complexes are considerably easier to oxidize than analogous mono(porphyrin) species, and the M(porph){sub 2{sup n+}} cations (n = 1,2) exhibit near-IR absorptions not found in simple mono(porphyrin)cations. As part of the authors continuing effort to understand the factors that govern the electronic structures of bis(porphyrin) supermolecules, the authors now describe the synthesis of a series of zirconium sandwich complexes. Introduction of electron-withdrawing or -donating groups on the {beta}-pyrrole position considerably affects the electronic properties of these molecules without altering their steric parameters. Thus, peripheral substitution allows modification of the inter-porphyrin {pi} interactions while keeping the inter-porphyrin separation constant. Previous studies have changed the identity of the central metal, but the electronic structure and the interplanar distance could not be varied independently.

  1. Adaptarea culturală a MAB-II (Multidimensional Aptitude Battery în România

    Directory of Open Access Journals (Sweden)

    Dragoş Iliescu

    2009-01-01

    Full Text Available This study examined the cultural adaptation of the Multidimensional Aptitude Battery II in Romania. Cultural adaptation of the items and the standardization process are described. The psychometric characteristics of the Romanian version are shown to be excellent in terms of reliability and construct validity (intertest correlations and EFA. Further studies conducted in Romania are discussed, both on the correlation with other cognitive ability tests and on the criterion validity of the MAB-II.

  2. Adaptarea culturală a MAB-II (Multidimensional Aptitude Battery) în România

    OpenAIRE

    Dragoş Iliescu; Florin Glintă; Dan Ispas

    2009-01-01

    This study examined the cultural adaptation of the Multidimensional Aptitude Battery II in Romania. Cultural adaptation of the items and the standardization process are described. The psychometric characteristics of the Romanian version are shown to be excellent in terms of reliability and construct validity (intertest correlations and EFA). Further studies conducted in Romania are discussed, both on the correlation with other cognitive ability tests and on the criterion validity of the MAB-II.

  3. The "New Polyethylene Glycol Dilemma": Polyethylene Glycol Impurities and Their Paradox Role in mAb Crystallization.

    Science.gov (United States)

    Hildebrandt, Christian; Joos, Lea; Saedler, Rainer; Winter, Gerhard

    2015-06-01

    Polyethylene glycols (PEG) represent the most successful and frequently applied class of excipients used for protein crystallization. PEG auto-oxidation and formation of impurities such as peroxides and formaldehydes that foster protein drug degradation is known. However, their effect on mAb crystallization has not been studied in detail before. During the present study, a model IgG1 antibody (mAb1) was crystallized in PEG solutions. Aggregate formation was observed during crystallization and storage that was ascribed to PEG degradation products. Reduction of peroxide and formaldehyde levels prior to crystallization by vacuum and freeze-drying was investigated for its effect on protein degradation. Vacuum drying was superior in removal of peroxides but inferior in reducing formaldehyde residues. Consequently, double purification allowed extensive removal of both impurities. Applying of purified PEG led to 50% lower aggregate fractions. Surprisingly, PEG double purification or addition of methionine prior to crystallization prevented crystal formation. With increased PEG concentration or spiking with peroxides and formaldehydes, crystal formation could be recovered again. With these results, we demonstrate that minimum amounts of oxidizing impurities and thus in consequence chemically altered proteins are vital to initiate mAb1 crystallization. The present study calls PEG as good precipitant for therapeutic biopharmaceuticals into question.

  4. Aree Protette del Po e della Collina Torinese: studi propedeutici alla Candidatura MAB - Man and the Biosphere

    Directory of Open Access Journals (Sweden)

    Cimnaghi Elisabetta

    2014-03-01

    Full Text Available Il programma MAB fu lanciato dall’UNESCO negli anni ’70 al fine di migliorare il rapporto tra uomo e ambiente. Negli anni il programma ha portato al riconoscimento di Riserve della Biosfera che gli Stati Membri si impegnano a gestire nella prospettiva della conservazione delle risorse. L’Organismo Gestore dell’Area Protetta, partendo, da un lato, dalla consapevolezza della ricchezza ambientale che caratterizza il suo territorio e, dall’altro, del contesto di sviluppo antropico elevato in cui essa è situata, ha riconosciuto nel programma MAB un’opportunità per incrementare le sue attività di protezione e potenziamento delle risorse. Questo articolo descrive i primi risultati ottenuti negli studi preliminari per la Designazione al MAB, con particolare attenzione sia alle opportunità di implementazione di progetti legati al marchio “Collina Po”, creato dall’Organo di Gestione del Parco, si ain termini di scambio di ‘best practices’ con altre Riserve di Biosfera.

  5. Nonautonomous Roles of MAB-5/Hox and the Secreted Basement Membrane Molecule SPON-1/F-Spondin in Caenorhabditis elegans Neuronal Migration.

    Science.gov (United States)

    Josephson, Matthew P; Miltner, Adam M; Lundquist, Erik A

    2016-08-01

    Nervous system development and circuit formation requires neurons to migrate from their birthplaces to specific destinations.Migrating neurons detect extracellular cues that provide guidance information. In Caenorhabditis elegans, the Q right (QR) and Q left (QL) neuroblast descendants migrate long distances in opposite directions. The Hox gene lin-39 cell autonomously promotes anterior QR descendant migration, and mab-5/Hox cell autonomously promotes posterior QL descendant migration. Here we describe a nonautonomous role of mab-5 in regulating both QR and QL descendant migrations, a role masked by redundancy with lin-39 A third Hox gene, egl-5/Abdominal-B, also likely nonautonomously regulates Q descendant migrations. In the lin-39 mab-5 egl-5 triple mutant, little if any QR and QL descendant migration occurs. In addition to well-described roles of lin-39 and mab-5 in the Q descendants, our results suggest that lin-39, mab-5, and egl-5 might also pattern the posterior region of the animal for Q descendant migration. Previous studies showed that the spon-1 gene might be a target of MAB-5 in Q descendant migration. spon-1 encodes a secreted basement membrane molecule similar to vertebrate F-spondin. Here we show that spon-1 acts nonautonomously to control Q descendant migration, and might function as a permissive rather than instructive signal for cell migration. We find that increased levels of MAB-5 in body wall muscle (BWM) can drive the spon-1 promoter adjacent to the Q cells, and loss of spon-1 suppresses mab-5 gain of function. Thus, MAB-5 might nonautonomously control Q descendant migrations by patterning the posterior region of the animal to which Q cells respond. spon-1 expression from BWMs might be part of the posterior patterning necessary for directed Q descendant migration.

  6. Feasibility study of a SiC sandwich neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian, E-mail: caepwujian@163.com [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, Sichuan Province (China); Lei, Jiarong, E-mail: jiarong_lei@163.com [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, Sichuan Province (China); Jiang, Yong; Chen, Yu; Rong, Ru; Zou, Dehui; Fan, Xiaoqiang [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, Sichuan Province (China); Chen, Gang; Li, Li; Bai, Song [Nanjing Electronic Devices Institute, Nanjing 210016 (China)

    2013-04-21

    Semiconductor sandwich neutron spectrometers are suitable for in-pile measurements of fast reactor spectra thanks to their compact and relatively simple design. We have assembled and tested a sandwich neutron spectrometer based on 4H-silicon carbide (4H-SiC) Schottky diodes. The SiC diodes detect neutrons via neutron-induced charged particles (tritons and alpha particles) produced by {sup 6}Li(n,α){sup 3}H reaction. {sup 6}LiF neutron converter layers are deposited on the front surface of Schottky diodes by magnetron sputtering. The responses of SiC diodes to charged particles were investigated with an {sup 241}Am alpha source. A sandwich neutron spectrometer was assembled with two SiC Schottky diodes selected based on the charged-particle-response experimental results. The low-energy neutron response of the sandwich spectrometer was measured in the neutron field of the Chinese Fast Burst Reactor-II (CFBR-II). Spectra of alpha particles and tritons from {sup 6}Li(n,α){sup 3}H reaction were obtained with two well-resolved peaks. The energy resolution of the sum spectrum was 8.8%. The primary experimental results confirmed the 4H-SiC sandwich neutron spectrometer's feasibility. -- Highlights: ► Sandwich neutron spectrometer employing 4H-SiC as a detecting material has been developed for the first time. ► {sup 6}LiF neutron converter has been deposited on the surface of 4H-SiC Schottky diode. ► Preliminary testing results obtained with the 4H-SiC sandwich neutron spectrometer are presented.

  7. Enhancing Fatigue Performance of Sandwich Composites with Nanophased Core

    Directory of Open Access Journals (Sweden)

    S. Zainuddin

    2010-01-01

    Full Text Available We report fatigue performance of sandwich composites with nanophased core under shear load. Nanophased core was made from polyurethane foam dispersed with carbon nanofiber (CNF. CNFs were dispersed into part-A of liquid polyurethane through a sonication process and the loading of nanoparticles was 1.0 wt%. After dispersion, part-A was mixed with part-B, cast into a mold, and allowed to cure. Nanophased foam was then used to fabricate sandwich composites. Static shear tests revealed that strength and modulus of nanophased foams were 33% and 19% higher than those of unreinforced (neat foams. Next, shear fatigue tests were conducted at a frequency of 3 Hz and stress ratio (R of 0.1. S-N curves were generated and fatigue performances were compared. Number of cycles to failure for nanophased sandwich was significantly higher than that of the neat ones. For example, at 57% of ultimate shear strength, nanophased sandwich would survive 400,000 cycles more than its neat counterpart. SEM micrographs indicated stronger cell structures with nanophased foams. These stronger cells strengthened the sub-interface zones underneath the actual core-skin interface. High toughness of the sub-interface layer delayed initiation of fatigue cracks and thereby increased the fatigue life of nanophased sandwich composites.

  8. Critical velocity of sandwich cylindrical shell under moving internal pressure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Critical velocity of an infinite long sandwich shell under moving internal pres-sure is studied using the sandwich shell theory and elastodynamics theory. Propagation of axisymmetric free harmonic waves in the sandwich shell is studied using the sandwich shell theory by considering compressibility and transverse shear deformation of the core, and transverse shear deformation of face sheets. Based on the elastodynamics theory, displacement components expanded by Legendre polynomials, and position-dependent elastic constants and densities are introduced into the equations of motion. Critical ve-locity is the minimum phase velocity on the desperation relation curve obtained by using the two methods. Numerical examples and the finite element (FE) simulations are pre-sented. The results show that the two critical velocities agree well with each other, and two desperation relation curves agree well with each other when the wave number κ is relatively small. However, two limit phase velocities approach to the shear wave velocities of the face sheet and the core respectively when k limits to infinite. The two methods are efficient in the investigation of wave propagation in a sandwich cylindrical shell when κ is relatively small. The critical velocity predicted in the FE simulations agrees with theoretical prediction.

  9. Experimental study on mechanical properties of aircraft honeycomb sandwich structures

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

    Full Text Available Mechanical behaviour of sandwich panels under different conditions have been exprimentally studied in this research to increase the knowledge of aircraft sandwich panel structures and facilitate design criteria for aircraft structures. Tests were concentrated on the honeycomb sandwich structures under different loads including flexural, insert shear, flat wise tension and compression loads. Furthermore, effect of core density and face material on mechanical behavior of different samples were investigated and compared with analytical and FEM method. Effects of skin thickness on strength of honycomb sandwhich panels under shear pull out and moments have also been considerd in this study. According to this investigation, insert strength and flexural test under different load conditions is strongly affected by face thickness, but compression and tearoff (falt wise tensile properties of a sandwich panel depends on core material. The study concludes that the correlation between experimental results and the analytical predictions will enable the designer to predict the mechanical behaviour and strength of a sandwich beam; however, applied formula may lead engineers to unreliable results for shear modulus.

  10. A comparison of FRP-sandwich penetrating impact test methods

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, M. [VTT Manufacturing Technology, Espoo (Finland). Maritime and Mechanical Engineering

    1996-12-31

    The main objective of this project is to identify the test methods which provide useful results for the different types of penetrating impacts occurring in sandwich structures. A series of penetrating impact tests on FRP-sandwich panels is performed using three different test methods and the results of the test methods are compared. The test methods used are the standardised method ISO 6603 and two non-standardised methods. The first non-standardised method uses a pyramid-shaped impactor instead of the cylindrical impactor used in the ISO 6603 method. In the second non-standardised method, the impact test is performed quasistatically using a cylindrical impactor. Possible stages of failure occurring in FRP-sandwich during a penetrating impact are illustrated. A comprehensive test method should be able to provoke various failure modes, as observed in impact failures of actual sandwich structures. The results obtained with the three test methods lead to a different ranking in impact strength of the panels. Hence, impact test results obtained with different test methods are not even qualitatively comparable. The pyramid-shaped impactor is able to generate clearly more failure modes than the cylindrical impactor in the ISO 6603 method. Therefore, it is considered to be of more practical value for determining the impact strength of PRP-sandwich structures. (orig.) (15 refs.)

  11. Thermal buckling analysis of truss-core sandwich plates

    Institute of Scientific and Technical Information of China (English)

    陈继伟; 刘咏泉; 刘伟; 苏先樾

    2013-01-01

    Truss-core sandwich plates have received much attention in virtue of the high values of strength-to-weight and stiffness-to-weight as well as the great ability of impulse-resistance recently. It is necessary to study the stability of sandwich panels under the influence of the thermal load. However, the sandwich plates are such complex three-dimensional (3D) systems that direct analytical solutions do not exist, and the finite element method (FEM) cannot represent the relationship between structural parameters and mechanical properties well. In this paper, an equivalent homogeneous continuous plate is idealized by obtaining the effective bending and transverse shear stiffness based on the characteristics of periodically distributed unit cells. The first order shear deformation theory for plates is used to derive the stability equation. The buckling temperature of a simply supported sandwich plate is given and verified by the FEM. The effect of related parameters on mechanical properties is investigated. The geometric parameters of the unit cell are optimized to attain the maximum buckling temperature. It is shown that the optimized sandwich plate can improve the resistance to thermal buckling significantly.

  12. Design of sandwich acoustic window for sonar domes

    Institute of Scientific and Technical Information of China (English)

    YU Mengsa; LI Dongsheng; GONG Li; XU Jian

    2005-01-01

    Aimed at the low noise design of sonar dome in ships, a method has been presented for calculating the sonar self noise of a simplified sonar dome consisting of sandwich acoustic window and parallel acoustic cavity, which is excited by stationary random pressure fluctuation of turbulence boundary layer, using temporal and spatial double Fourier transform and wavenumber-frequency spectrum analysis. After numerically analyzing the influence of geometrical and physical parameters of acoustic window on the sonar self noise, the design method and reasonable parameters for sandwich acoustic window are proposed. The results show that the property of low noise induced by acoustic window of sandwich is dominated by the cut-off effect of longitudinal wave and transverse wave propagating in the visco-elastic layer of sandwich as well as the mismatch effect of impedance. If the thickness, density, Young's modulus and damping factor of plates and visco-elastic layer as well as the sound speed of longitudinal wave and transverse wave in the visco-elastic layer are selected reasonably, the maximum noise reduction of sandwich acoustic window is 6.5 dB greater than that of a single glass fiber reinforced plastic plate.

  13. Immunotherapeutic synergy between anti-CD137 mAb and intratumoral administration of a cytopathic Semliki Forest virus encoding IL-12

    National Research Council Canada - National Science Library

    Quetglas, José I; Dubrot, Juan; Bezunartea, Jaione; Sanmamed, Miguel F; Hervas-Stubbs, Sandra; Smerdou, Cristian; Melero, Ignacio

    2012-01-01

    .... In this study, we provide evidence for powerful synergistic effects of a combined strategy consisting of intratumoral injection of SFV-IL-12 and systemic delivery of agonist anti-CD137 monoclonal antibodies (mAbs...

  14. Ham Sandwich with Mayo: A Stronger Conclusion to the Classical Ham Sandwich Theorem

    CERN Document Server

    Elton, John H

    2009-01-01

    The conclusion of the classical ham sandwich theorem of Banach and Steinhaus may be strengthened: there always exists a common bisecting hyperplane that touches each of the sets, that is, intersects the closure of each set. Hence, if the knife is smeared with mayonnaise, a cut can always be made so that it will not only simultaneously bisect each of the ingredients, but it will also spread mayonnaise on each. A discrete analog of this theorem says that n finite nonempty sets in n-dimensional Euclidean space can always be simultaneously bisected by a single hyperplane that contains at least one point in each set. More generally, for n compactly-supported positive finite Borel measures in Euclidean n-space, there is always a hyperplane that bisects each of the measures and intersects the support of each measure.

  15. 1/3 SUBHARMONIC SOLUTION OF ELLIPTICAL SANDWICH PLATES

    Institute of Scientific and Technical Information of China (English)

    李银山; 张年梅; 杨桂通

    2003-01-01

    The problem of nonlinear forced oscillations for elliptical sandwich plates is dealtwith. Based on the governing equations expressed in terms of five displacement components,the nonlinear dynamic equation of an elliptical sandwich plate under a harmonic force isderived. A superpositive-iterative harmonic balance ( SIHB ) method is presented for thesteady-state analysis of strongly nonlinear oscillators. In a periodic oscillation, the periodicsolutions can be expressed in the form of basic harmonics and bifurcate harmonics. Thus,an oscillation system which is described as a second order ordinary differential equation,can be expressed as fundamental differential equation with fundamental harmonics andincremental differential equation with derived harmonics. The 1/3 subharnonic solution ofan elliptical sandwich plate is investigated by using the methods of SIHB. The SIHB methodis compared with the numerical integration method. Finally, asymptotical stability of the1/3 subharmonic oscillations is inspected.

  16. Sandwich complex-containing macromolecules: property tunability through versatile synthesis.

    Science.gov (United States)

    Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

    2014-03-01

    Sandwich complexes feature unique properties as the physical and electronic properties of a hydrocarbon ligand or its derivative are integrated into the physical, electronic, magnetic, and optical properties of a metal. Incorporation of these complexes into macromolecules results in intriguing physical, electrical, and optical properties that were hitherto unknown in organic-based macromolecules. These properties are tunable through well-designed synthetic strategies. This review surveys many of the synthetic approaches that have resulted in tuning the properties of sandwich complex-containing macromolecules. While the past two decades have seen an ever-growing number of research publications in this field, gaps remain to be filled. Thus, we expect this review to stimulate research interest towards bridging these gaps, which include the insolubility of some of these macromolecules as well as expanding the scope of the sandwich complexes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Identification of material properties of sandwich structure with piezoelectric patches

    Directory of Open Access Journals (Sweden)

    Zemčík R.

    2008-11-01

    Full Text Available The work focuses on light-weight sandwich structures made of carbon-epoxy skins and foam core which have unique bending stiffness compared to conventional materials. The skins are manufactured by vacuum autoclave technology from unidirectional prepregs and the sandwich is then glued together. The resulting material properties of the structure usually differ from those provided by manufacturer or even those obtained from experimental tests on separate materials, which makes computational models unreliable. Therefore, the properties are identified using the combination of experimental analysis of the sandwich with attached piezoelectric transducer and corresponding static and modal finite element analyses. Simple mathematical optimization with repetitive finite element solution is used. The model is then verified by transient analysis when the piezoelectric patch is excited by harmonic signals covering the first two eigen-frequencies and the induced oscillations are measured by laser sensor.

  18. Microtomography with sandwich detectors for small-animal bone imaging

    Science.gov (United States)

    Kim, S. H.; Kim, D. W.; Kim, D.; Youn, H.; Cho, S.; Kim, H. K.

    2016-10-01

    An x-ray radiographic system consisting of two detectors in tandem, or a sandwich detector, can produce dual-energy image from a single-shot exposure. Subtraction of two images obtained from the two detectors can produce a sharper image through an unsharp masking effect if the two images are formed at different spatial resolutions. This is indeed possible by incorporating different thicknesses of x-ray conversion layers in the detectors. In this study, we have developed a microtomography system with a sandwich detector in pursuit of high-resolution bone-enhanced small-animal imaging. The results show that the bone-enhanced images reconstructed from the dual-energy projection data provide higher visibility of bone details than the conventionally reconstructed images. The microtomography with the single-shot dual-energy sandwich detector will be useful for the high-resolution bone-enhanced small-animal imaging.

  19. Free vibration Analysis of Sandwich Plates with cutout

    Science.gov (United States)

    Mishra, N.; Basa, B.; Sarangi, S. K.

    2016-09-01

    This paper presents the free vibration analysis of sandwich plates with cutouts. Cutouts are inevitable in structural applications and the presence of these cutouts in the structures greatly influences their dynamic characteristics. A finite element model has been developed here using the ANSYS 15.0 software to study the free vibration characteristics of sandwich plates in the presence of cutouts. Shell 281 element, an 8-noded element with six degrees of freedom suited for analyzing thin to moderately thick structures is considered in the development of the model. Block Lanczose method is adopted to extract the mode shapes to obtain the natural frequency corresponding to free vibration of the plate. The effects of parametric variation on the natural frequency of the sandwich plates with cutout are studied and results are presented.

  20. Enhanced Performance of Sandwich Structures by Improved Damage Tolerance

    DEFF Research Database (Denmark)

    Martakos, Georgios

    The PhD thesis investigates the enhancement of the damage tolerance of sandwich structures by the embedding of a new type of core inserts that act as face/core interface crack stopping elements. The thesis presents series of experimental investigations where the new crack stopping elements...... are embedded in both sandwich beam and panel specimens. The experimental observations form the basis for evaluating the efficiency of the proposed crack stopping inserts. For the experiments, Digital Image Correlation (DIC) was used to characterize the measure the local strain fields and overall deformation...... behaviour around the new crack stopper elements. In support for the experimental investigations, a Finite Element (FE) analysis based methodology, including fracture mechanics analysis and the so-called ‘cycle jump’ technique, was developed to predict the progression of damage in sandwich specimens...

  1. ANALISIS KERAGAAN PANEL SANDWICH UNTUK RUMAH PRA-PABRIKASI

    Directory of Open Access Journals (Sweden)

    Naresworo Nugroho

    2010-12-01

    Full Text Available In the last five years, several earthquakes struck several places in Indonesia and thousands of people died caused of their masonry house. Therefore, the idea of bamboo utilization in the form of structural sandwich panel components for anti-seismic pre-fabrication house is one of appropriate way out. This research describes the performance and behavior of engineered structure wooden-bamboo sandwich panel in full sized test. The wall frame being use were meranti wood, this frame attached by plywood as face and back, then 5 cm bamboo cutting as core; the fastener used in this study were isocyanate resin and nails. This study carried out by experimental data of full scale structural tests on shear wall (ISO 22452. These result showed that the seismic reliability of the wall frame system made of bamboo sandwich panel was appropriate and will be useful for pre-fabrication houses as anti-seismic and environment friendly residential building

  2. Study on voids of epoxy matrix composites sandwich structure parts

    Science.gov (United States)

    He, Simin; Wen, Youyi; Yu, Wenjun; Liu, Hong; Yue, Cheng; Bao, Jing

    2017-03-01

    Void is the most common tiny defect of composite materials. Porosity is closely related to composite structure property. The voids forming behaviour in the composites sandwich structural parts with the carbon fiber reinforced epoxy resin skins was researched by adjusting the manufacturing process parameters. The composites laminate with different porosities were prepared with the different process parameter. The ultrasonic non-destructive measurement method for the porosity was developed and verified through microscopic examination. The analysis results show that compaction pressure during the manufacturing process had influence on the porosity in the laminate area. Increasing the compaction pressure and compaction time will reduce the porosity of the laminates. The bond-line between honeycomb core and carbon fiber reinforced epoxy resin skins were also analyzed through microscopic examination. The mechanical properties of sandwich structure composites were studied. The optimization process parameters and porosity ultrasonic measurement method for composites sandwich structure have been applied to the production of the composite parts.

  3. Examination of Sandwich Materials Using Air-Coupled Ultrasonics

    DEFF Research Database (Denmark)

    Borum, K.K.; Berggreen, Carl Christian

    2004-01-01

    The air-coupled ultrasonic techniques have been improved drastically in recent years. Better equipment has made this technique much more useful. This paper focuses on the examination of sandwich materials used in naval ships. It is more convenient to be able to make the measurements directly...... in atmospheric air instead of using immersion technique. The air-coupled techniques have been used in through-transmission mode using separate sender and receiver transducer. The frequency was either 50 kHz or 120 kHz. Laboratory tests on glass fibre/PVC foam core sandwich panels showed that debonds between core...... and skin laminate could be found by the air-coupled technique. It was therefore decided to use this technique in-situ during mechanical testing of sandwich panels. These tests were done in order to verify a developed FEM code using interfacial fracture mechanics and illustrated on a superstructure...

  4. Effect of layer length on deflection in sandwich beams

    Science.gov (United States)

    Abbu, Muthanna A.; AL-Ameri, Riyadh

    2017-09-01

    A theoretical study has been carried out on sandwich beams strengthened mechanically by two external steel plates attached to their tension and compression sides with so-called "shear connectors ". This study is based on the individual behaviour of each component of the composite sandwich section (i.e. reinforced concrete beam and upper steel plate and lower steel plate). The approach has been developed to simulate the behaviour of such beams, and is based on neglecting the separation between the three layers; i.e., the deflections are equal in each element through the same section. The differential equations reached were solved analytically. Deflection was calculated by using the approach for several beams, tested in two series, and close agreements were obtained with the experimental values. Furthermore, the interaction efficiency between the three elements in a composite sandwich beam has been considered thoroughly, from which the effect of some parameters, such as plate length upon the behaviour of such beams, were studied.

  5. Vibration analysis and optimization of sandwich composite with curvilinear fibers

    Science.gov (United States)

    Honda, S.; Narita, Y.

    2016-09-01

    The present paper develops a shell element based on the refined zigzag theory (RZT) and applies it to the vibration analysis and optimization problem of the composite sandwich plate composed of CFRP skins and soft-cores. The RZT accepts large differences in layer stiffness, and requires less calculation effort than the layer-wise or three-dimensional theories. Numerical results revealed that the present method predicts vibration characteristics of composite sandwich plates with soft-core accurately. Then, shapes of reinforcing fibers in CFRP composite skins are optimized to maximize fundamental frequencies. As an optimizer, the particle swarm optimization (PSO) approach is employed since curvilinear fiber shapes are defined by continuous design variables. Obtained results showed that the composite sandwich with optimum curvilinear fiber shapes indicates higher fundamental frequencies compared with straight fibers.

  6. ['Sandwich PhD': considerations for a successful experience abroad].

    Science.gov (United States)

    Salvetti, Marina de Goes; Bueno, Mariana; Gastaldo, Denise; Kimura, Amélia Fumiko; Pimenta, Cibele Andrucioli de Mattos

    2013-03-01

    International PhD internship, named "Sandwich PhD" in Brazil is an opportunity to improve research abilities, to become known in academic area and to establish and/or increase work opportunities in an international context. In this article, we describe key factors regarding the planning and development of the "Sandwich PhD" as experienced by professors and students involved in the collaboration between the School of Nursing, University of São Paulo and Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Canada. We also present the participation of PhD students' network as an alternative to the "Sandwich PhD". An international experience, when well-planned and developed correctly, promotes students' personal and professional development and favors the internationalization of Brazilian graduate programs and research groups.

  7. Extended high order sandwich panel theory for bending analysis of sandwich beams with carbon nanotube reinforced face sheets

    Science.gov (United States)

    Jedari Salami, S.

    2016-02-01

    Bending analysis of a sandwich beam with soft core and carbon nanotube reinforced composite (CNTRC) face sheets in the literature is presented based on Extended High order Sandwich Panel Theory (EHSAPT). Distribution of fibers through the thickness of the face sheets could be uniform or functionally graded (FG). In this theory the face sheets follow the first order shear deformation theory (FSDT). Besides, the two dimensional elasticity is used for the core. The field equations are derived via the Ritz based solution which is suitable for any essential boundary condition. The influences of boundary conditions on bending response of the sandwich panel with soft core and CNTRC face sheet are investigated. In each type of boundary condition the effect of distribution pattern of CNTRCs on many essential involved parameters of the sandwich beam with functionally graded carbon nanotube reinforced composite (FG- CNTRC) face sheets are studied in detail. Finally, experimental result have been compared with those obtained based on developed solution method. It is concluded that, the sandwich beam with X distribution figure of face sheets is the strongest with the smallest transverse displacement, and followed by the UD, O and ∧-ones, respectively.

  8. Ultrasonic atomization and subsequent desolvation for monoclonal antibody (mAb) to the glycoprotein (GP) IIIa receptor into drug eluting stent.

    Science.gov (United States)

    Wang, G X; Luo, L L; Yin, T Y; Li, Y; Jiang, T; Ruan, C G; Guidoin, R; Chen, Y P; Guzman, R

    2010-01-01

    An eluting-stent system with mAb dispersed in the PLLA (poly (L-lactic acid)) was validated in vitro. Specifically designed spray equipment based on the principle of ultrasonic atomization was used to produce a thin continuous PLLA (poly (L-lactic acid)) polymer coating incorporating monoclonal antibody (mAb). This PLLA coating was observed in light microscopy (LM) and scanning electron microscopy (SEM). The concentration of the monoclonal antibody (mAb) to the platelet glycoprotein (GP) IIIa receptor and the eluting rate were then measured by a radioisotope technique with (125)I-labelled GP IIIa mAb. An in vitro perfusion circuit was designed to evaluate the release rates at different velocities (10 or 20 ml min(-1)). The PLLA coating was thin and transparent, uniformly distributed on the surface of the stent. Three factors influenced its thickness: PLLA concentration, duration and gas pressure. The concentration of mAb was influenced by the duration of absorption and the concentration of the mAb solution; the maximum was 1662.23 + or - 38.83 ng. The eluting rate was fast for the first 2 h, then decreased slowly and attained 80% after 2 weeks. This ultrasonic atomization spray equipment and technological process to prepare protein eluting-stents were proved to be effective and reliable.

  9. Molecular characterization of cold-responsive basic helix-loop-helix transcription factors MabHLHs that interact with MaICE1 in banana fruit.

    Science.gov (United States)

    Peng, Huan-Huan; Shan, Wei; Kuang, Jian-Fei; Lu, Wang-Jin; Chen, Jian-Ye

    2013-11-01

    Basic helix-loop-helix (bHLH) transcription factors (TFs) are ubiquitously involved in the response of higher plants to various abiotic stresses. However, little is known about bHLH TFs involved in the cold stress response in economically important fruits. Here, five novel full-length bHLH genes, designated as MabHLH1-MabHLH5, were isolated and characterized from banana fruit. Gene expression profiles revealed that MabHLH1/2/4 were induced by cold stress and methyl jasmonate (MeJA) treatment. Transient assays in tobacco BY2 protoplasts showed that MabHLH1/2/4 promoters were activated by cold stress and MeJA treatments. Moreover, protein-protein interaction analysis demonstrated that MabHLH1/2/4 not only physically interacted with each other to form hetero-dimers in the nucleus, but also interacted with an important upstream component of cold signaling MaICE1, with different interaction domains at their N-terminus. These results indicate that banana fruit cold-responsive MabHLHs may form a big protein complex in the nucleus with MaICE1. Taken together, our findings advance our understanding of the possible involvement of bHLH TFs in the regulatory network of ICE-CBF cold signaling pathway.

  10. Small-Animal PET Imaging of Pancreatic Cancer Xenografts Using a 64Cu-Labeled Monoclonal Antibody, MAb159.

    Science.gov (United States)

    Wang, Hui; Li, Dan; Liu, Shuanglong; Liu, Ren; Yuan, Hong; Krasnoperov, Valery; Shan, Hong; Conti, Peter S; Gill, Parkash S; Li, Zibo

    2015-06-01

    Overexpression of the GRP78 receptor on cell surfaces has been linked with tumor growth, metastasis, and resistance to therapy. We developed a (64)Cu-labeled probe for PET imaging of tumor GRP78 expression based on a novel anti-GRP78 monoclonal antibody, MAb159. MAb159 was conjugated with the (64)Cu-chelator DOTA through lysines on the antibody. DOTA-human IgG was also prepared as a control that did not bind to GRP78. The resulting PET probes were evaluated in BXPC3 pancreatic cancer xenografts in athymic nude mice. The radiotracer was synthesized with a specific activity of 0.8 MBq/μg of antibody. In BXPC3 xenografts, (64)Cu-DOTA-MAb159 demonstrated prominent tumor accumulation (4.3 ± 1.2, 15.4 ± 2.6, and 18.3 ± 1.0 percentage injected dose per gram at 1, 17, and 48 after injection, respectively). In contrast, (64)Cu-DOTA-human IgG had low BXPC3 tumor accumulation (4.8 ± 0.5, 7.5 ± 0.7, and 4.6 ± 0.8 percentage injected dose per gram at 1, 17, and 48 h after injection, respectively). We demonstrated that GRP78 can serve as a valid target for pancreatic cancer imaging. The success of this approach will be valuable for evaluating disease course and therapeutic efficacy at the earliest stages of anti-GRP78 treatment. Moreover, these newly developed probes may have important applications in other types of cancer overexpressing GRP78. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  11. Methods for Using Durable Adhesively Bonded Joints for Sandwich Structures

    Science.gov (United States)

    Smeltzer, Stanley S., III (Inventor); Lundgren, Eric C. (Inventor)

    2016-01-01

    Systems, methods, and apparatus for increasing durability of adhesively bonded joints in a sandwich structure. Such systems, methods, and apparatus includes an first face sheet and an second face sheet as well as an insert structure, the insert structure having a first insert face sheet, a second insert face sheet, and an insert core material. In addition, sandwich core material is arranged between the first face sheet and the second face sheet. A primary bondline may be coupled to the face sheet(s) and the splice. Further, systems, methods, and apparatus of the present disclosure advantageously reduce the load, provide a redundant path, reduce structural fatigue, and/or increase fatigue life.

  12. NONLINEAR VIBRATION OF CIRCULAR SANDWICH PLATES UNDER CIRCUMJACENT LOAD

    Institute of Scientific and Technical Information of China (English)

    DU Guo-jun; MA Jian-qing

    2006-01-01

    Based on yon Karman plate theory, the issue about nonlinear vibration for circular sandwich plates under circumjacent load with the loosely clamped boundary condition was researched. Nonlinear differential eigenvalue equations and boundary conditions of the problem were formulated by variational method and then their exact static solution can be got. The solution was derived by modified iteration method, so the anslytic relations between amplitude and nonlinear oscillating frequency for circular sandwich plates were obtained. When circumjacent load makes the lowest natural frequency zero,critical load is obtained.

  13. Electronic States in Quasi-one-Dimensional Copolymeric Sandwich Structures

    Institute of Scientific and Technical Information of China (English)

    刘德胜; 王鹿霞; 魏建华; 郑斌; 解士杰; 韩圣浩; 梅良模

    2001-01-01

    The electronic properties of xPA/nPPP/yPA sandwiched copo]ymers with a well-barrier-well structure have been studied by using a tight-binding calculation. It was found that the electronic properties of the neutral states of these sandwiched copolymers are sensitive to the constitutions of PPP and PA monomers and the interface coupling between PA and PPP. It is verified that the quantum tunnelling effect will occur at the lowest conductive state of xPA/nPPP/xPA copolymers.

  14. A New Silicon-Based Ferroelectric Sandwich Structure

    Institute of Scientific and Technical Information of China (English)

    任天令; 张林涛; 刘理天; 李志坚

    2001-01-01

    A new silicon-based PbTiO3/Pb(Zr0.53 Ti0.47)O3/PbTiO3 sandwich structure is fabricated by a sol-gel method. Compared with other fabrication processes without PbTiO3 buffer layers, the annealing temperature is greatly reduced by as much as 100℃. Capacitance-voltage, polarization-electric field and dielectric-frequency properties of this sandwich structure are studied. The Pb(Zrx Ti1-x)O3 films are proved to have good dielectric and ferroelectric properties.

  15. New-sandwiched hydrogen separation membranes with low environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Ozaki, T.; Komaki, M.; Nishimura, C. [Eco-Energy Materials Group, Ecomaterials Center, Ibaraki (Japan)

    2003-07-01

    There is a strong interest in economical methods for hydrogen separation. In this work, we have developed sandwiched membranes, Pd-Ag/V-15Ni/Pd-Ag, which had much lower environmental impact than palladium-based membranes, which are the most commonly used membrane for the current production of highly pure hydrogen. The Pd-Ag overlayer was prepared on V-15Ni substrates (thickness 40 {mu}m) using multi-target sputtering. The hydrogen permeation of the Pd-Ag/V-15Ni/Pd-Ag sandwiched membranes was examined using gas permeation technology. (orig.)

  16. Friction stir welding (FSW of aluminium foam sandwich panels

    Directory of Open Access Journals (Sweden)

    M. Bušić

    2016-07-01

    Full Text Available The article focuses on the influence of welding speed and tool tilt angle upon the mechanical properties at the friction stir welding of aluminium foam sandwich panels. Double side welding was used for producing butt welds of aluminium sandwich panels applying insertion of extruded aluminium profile. Such insertion provided lower pressure of the tool upon the aluminium panels, providing also sufficient volume of the material required for the weldment formation. Ultimate tensile strength and flexural strength for three-point bending test have been determined for samples taken from the welded joints. Results have confirmed anticipated effects of independent variables.

  17. Buckling analysis of sandwich plate using layer wise theory

    Energy Technology Data Exchange (ETDEWEB)

    Ranjbaran, Arash; Khoshravan, Mohammad Reza [University of Tabriz, Tabriz (Iran, Islamic Republic of); Kharazi, Mahsa [Sahand University of Technology, Sahand (Iran, Islamic Republic of)

    2014-07-15

    Buckling analysis of sandwich plate was investigated using layer wise method. The formulation was based on the first-order shear deformation theory, and the Rayleigh-Ritz method was used for approximating and determining the displacement field. The results obtained from layer wise theory was compared with finite element results and showed good agreement. This study demonstrated that layer wise theory could describe buckling behavior of sandwich plates with high accuracy and represents a more realistic and acceptable description of behavior of the plates with much less computational cost.

  18. Damage assessment of compression loaded debond damaged sandwich panels

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Berggreen, Christian; Quispitupa, Amilcar;

    2010-01-01

    Sandwich composites with face sheets of fiber-reinforced plastics (FRP) and cores of polymer foam offer a lightweight construction that is well suited to wind turbine blades, naval and other vessels for high-speed operation or where payload considerations require that the structural weight...... with an implanted circular face/core debond. Compression tests were conducted on intact sandwich panels and panels with an implanted circular face/core debond with three different types of foam core materials (PVC H130, PVC H250 and PMI 51-IG). The strains and out-of-plane displacements of the debonded region were...

  19. Fabrication and characterization of sandwiched optical fibers with periodic gratings.

    Science.gov (United States)

    Chiang, Chia-Chin

    2010-08-01

    This study proposes a novel process for fabricating a sandwiched long-period fiber grating (SLPFG) using a SU-8 thick photoresist technique. The SLPFG consists of a thin cladding optical fiber sandwiched with a double-sided periodical grating coating. By varying the external loads on the SLPFG, the transmission dip of the resonance wavelength is tuned according to a squared-harmonic curve. The SLPFG can thus be utilized as a loss tunable filter or sensor. The resonance dip wavelength is related to the cladding thicknesses of the optical fiber and the periods of the grating. A maximum transmission resonant dip of 34.61dB was achieved.

  20. Comparisons of SHM Sensor Models with Empirical Test Data for Sandwich Composite Structures

    Science.gov (United States)

    2011-09-01

    propagation in a honeycomb sandwich panel was done by Metis Design Inc. in collaboration with ARC NASA . The sandwich panel fabricated for this test...structures. Sandwich type composites are being studied for use in NASAs new heavy lift launch vehicle and flaw detection is crucial for safety and for...and at the Marshall Space Flight Center to examine acoustic wave propagating and the ability to detect intrinsic faults in sandwich type composite

  1. Stabilization of nonlinear sandwich systems via state feedback-Discrete-time systems

    NARCIS (Netherlands)

    Wang, Xu; Stoorvogel, Anton A.; Saberi, Ali; Grip, H°avard Fjær; Sannuti, Peddapullaiah

    2011-01-01

    A recent paper (IEEE Trans. Aut. Contr. 2010; 55(9):2156–2160) considered stabilization of a class of continuous-time nonlinear sandwich systems via state feedback. This paper is a discrete-time counterpart of it. The class of nonlinear sandwich systems consists of saturation elements sandwiched bet

  2. A modified DCB sandwich specimen for measuring mixed-mode cohesive laws

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Sørensen, Bent F.; Berggreen, Christian;

    2008-01-01

    A test method is described for measuring cohesive laws for interfaces in sandwich structures. It is proposed to increase the bending stiffness of the sandwich faces by adhering steel bars onto the sandwich faces. This stiffening reduces rotations and ensures that the method is applicable for thin...... which mixed-mode cohesive laws are extracted....

  3. Modifiche compositive e strutturali in soprassuoli in evoluzione naturale della riserva M.a.B. di Montedimezzo (Isernia

    Directory of Open Access Journals (Sweden)

    Maria Chiara Manetti

    2009-12-01

    Full Text Available Tree species composition and structural dynamics in forest stands under natural evolution in the Montedimezzo M.a.B. reserve. This study is included in an experimental protocol established in 1954 aimed at examining the natural dynamics in mixed broadleaves high forests dominated by Turkey oak (Quercus cerris L. and beech (Fagus sylvatica L.. Stand development patterns in the last fifteen years are reported. Repeated quantitative and qualitative inventories were carried out in two permanent plots (3 ha each and in two structural transects (0.2 ha each located in Collemeluccio-Montedimezzo M.a.B. reserve (Is. The study highlighted, as already observed in 1954, the differences between the two multilayered stands. In the higher elevation beech is the predominant species recording 53% of importance value index (I, followed by Turkey oak (I=25%. In the lower elevation the dominant species is Turkey oak (I=46%, followed by hornbeam (Carpinus betulus L. (I=28% and beech (I=12%. The decreased presence of Turkey oak and the increase of beech density are confirmed in each plot over the last fifteen years. Among the other tree species, importance values rise only for silver fir (Abies alba Mill. (introduced and holly tree (Ilex aquifolium L., while hornbeam and hedge maple have been reducing their own presence.

  4. Endocrine side-effects of anti-cancer drugs: mAbs and pituitary dysfunction: clinical evidence and pathogenic hypotheses.

    Science.gov (United States)

    Torino, Francesco; Barnabei, Agnese; Paragliola, Rosa Maria; Marchetti, Paolo; Salvatori, Roberto; Corsello, Salvatore Maria

    2013-12-01

    mAbs are established targeted therapies for several diseases, including hematological and solid malignancies. These agents have shown a favorable toxicity profile, but, despite their high selectivity, new typical side-effects have emerged. In cancer patients, pituitary dysfunction may be mainly due to brain metastases or primary tumors and to related surgery and radiotherapy. Anticancer agents may induce hypopituitarism in patients cured for childhood cancers. These agents infrequently affect pituitary function in adult cancer patients. Notably, hypophysitis, a previously very rare disease, has emerged as a distinctive side-effect of ipilimumab and tremelimumab, two mAbs inhibiting the cytotoxic T-lymphocyte antigen-4 receptor, being occasionally seen with nivolumab, another immune checkpoint inhibitor. Enhanced antitumor immunity is the suggested mechanism of action of these drugs and autoimmunity the presumptive mechanism of their toxicity. Recently, ipilimumab has been licensed for the treatment of patients affected by metastatic melanoma. With the expanding use of these drugs, hypophysitis will be progressively encountered by oncologists and endocrinologists in clinical practice. The optimal management of this potentially life-threatening adverse event needs a rapid and timely diagnostic and therapeutic intervention. Hypopituitarism caused by these agents is rarely reversible, requiring prolonged or lifelong substitutive hormonal treatment. Further studies are needed to clarify several clinical and pathogenic aspects of this new form of secondary pituitary dysfunction.

  5. A comparison of the biodistribution and biokinetics of {sup 99m}Tc-anti-CD66 mAb BW 250/183 and {sup 99m}Tc-anti-CD45 mAb YTH 24.5 with regard to suitability for myeloablative radioimmunotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Buchmann, Inga [Department of Nuclear Medicine, University Hospital, Ulm (Germany); Klinik und Poliklinik fuer Nuklearmedizin, Gebaeude 210, Johannes-Gutenberg-Universitaet Mainz, 55101, Mainz (Germany); Kull, Thomas; Glatting, Gerhard; Kotzerke, Jorg; Rattat, Dirk; Reske, Sven N. [Department of Nuclear Medicine, University Hospital, Ulm (Germany); Bunjes, Donald; Dohner, Hartmut [Department of Hematology, University Hospital, Ulm (Germany); Hale, Geoffrey [Sir William Dunn School of Pathology, Oxford (United Kingdom)

    2003-05-01

    Radioimmunotherapy (RIT) with radiolabelled monoclonal antibodies (mAbs) is an effective method of achieving myeloablation in leukaemia patients prior to stem cell transplantation (SCT). We wished to compare the approaches of specific binding to leukaemic blasts and non-specific binding to benign red marrow cells, which results in a myeloablative ''cross-fire'' effect. Therefore, we prospectively evaluated the biodistribution and biokinetics of the anti-CD45 mAb YTH 24.5 and the anti-CD66 mAb BW 250/183 with regard to their suitability for myeloablative RIT. The red marrow selective anti-CD66 mAb BW 250/183 (IgG1) binds to normal granulopoietic cells. In contrast, the anti-CD45 mAb YTH 24.5 (IgG2b) binds to 85-90% of acute leukaemic blasts and almost all haematopoietic white cells. Patients with leukaemic blast infiltration of the marrow <25% and assigned for RIT and SCT were included. Twelve patients (eight male, four female; median age 46{+-}7 years) with AML (5), CML (5) or ALL (2) were examined. Both mAbs were labelled with technetium-99m. Within 48 h, 906{+-}209 MBq {sup 99m}Tc-anti-CD66 mAb and 760{+-}331 MBq {sup 99m}Tc-anti-CD45 mAb were injected consecutively. Scintigraphic and urinary measurements were performed 1, 2, 4 and 24 h after injection. Serum activities were evaluated 2, 5, 10, 15, 30 and 60 min and 2, 4 and 24 h after injection. Compared with the anti-CD45 mAb, the anti-CD66 mAb showed an approximately fourfold higher accumulation in the red marrow, a 2.5-fold lower accumulation in the liver and similar accumulation in the kidneys. The serum activity (% of the injected dose) initially decreased faster for the anti-CD45 mAb but was similar for the two mAbs 24 h after injection: 3.3%{+-}1.2% (anti-CD66 mAb) and 2.4%{+-}1.1% (anti-CD45 mAb). The cumulated urinary excretion was 17%{+-}6.6% (anti-CD66 mAb) and 27.3%{+-}7.9% (anti-CD45 mAb) 24 h after application. In these patients with low tumour load, the anti-CD66 mAb BW 250

  6. Stiff, Strong Splice For A Composite Sandwich Structure

    Science.gov (United States)

    Schmaling, D.

    1991-01-01

    New type of splice for composite sandwich structure reduces peak shear stress in structure. Layers of alternating fiber orientation interposed between thin ears in adhesive joint. Developed for structural joint in spar of helicopter rotor blade, increases precision of control over thickness of adhesive at joint. Joint easy to make, requires no additional pieces, and adds little weight.

  7. Bending and Deformation of Sandwich Panels Due to Localized Pressure

    Directory of Open Access Journals (Sweden)

    Bambang K. Hadi

    2005-05-01

    Full Text Available Bending and deformation of sandwich panels due to localized pressure were analyzed using both Rayleigh-Ritz and finite element methods. The faces were made of laminated composite plates, while the core was a honeycomb material. Carbon fiber and glass fiber reinforced plastics were used for composite plate faces. In the case of Rayleigh-Ritz method, first the total energy of the system was calculated and then taking the variations of the total energy, the sandwich panel deflections could be computed. The deflections were assumed by means of Fourier series. A finite element code NASTRAN was exploited extensively in the finite element method. 3-dimensional 8-node brick elements were used to model sandwich panels, for both the faces sheets and the core. The results were then compared to each other and in general they are in good agreements. Dimple phenomena were found in these cases. It shows that localized pressure on sandwich structures will produce dimple on the pressurize region with little effects on the rest of the structures.

  8. Mechanical Behavior of CFRP Lattice Core Sandwich Bolted Corner Joints

    Science.gov (United States)

    Zhu, Xiaolei; Liu, Yang; Wang, Yana; Lu, Xiaofeng; Zhu, Lingxue

    2017-02-01

    The lattice core sandwich structures have drawn more attention for the integration of load capacity and multifunctional applications. However, the connection of carbon fibers reinforced polymer composite (CFRP) lattice core sandwich structure hinders its application. In this paper, a typical connection of two lattice core sandwich panels, named as corner joint or L-joint, was investigated by experiment and finite element method (FEM). The mechanical behavior and failure mode of the corner joints were discussed. The results showed that the main deformation pattern and failure mode of the lattice core sandwich bolted corner joints structure were the deformation of metal connector and indentation of the face sheet in the bolt holes. The metal connectors played an important role in bolted corner joints structure. In order to save the calculation resource, a continuum model of pyramid lattice core was used to replace the exact structure. The computation results were consistent with experiment, and the maximum error was 19%. The FEM demonstrated the deflection process of the bolted corner joints structure visually. So the simplified FEM can be used for further analysis of the bolted corner joints structure in engineering.

  9. Electronic transport in nanoparticle monolayers sandwiched between graphene electrodes.

    Science.gov (United States)

    Lu, Chenguang; Zhang, Datong; van der Zande, Arend; Kim, Philip; Herman, Irving P

    2014-11-06

    Graphene/CdSe nanoparticle monolayer/graphene sandwich structures were fabricated to explore the interactions between these layered materials. Electrical transport across these heterostructures suggests that transport is limited by tunneling through the nanoparticle (NP) ligands but not the NP core itself. Photoconductivity suggests ligands may affect the exciton separation efficiency.

  10. Elastic-plastic deformation of sandwich rod on elastic basis

    Institute of Scientific and Technical Information of China (English)

    GU Yu

    2008-01-01

    Sandwich composite material possesses advantages of both light weight and high strength.Although the mechanical behaviors of sandwich composite material with the influence of single external environment have been intensively studied,little work has been done in the study of mechanical property,in view of the nonlinear behavior of sandwich composites in the complicated external environments.In this paper,the problem about the bending of the three-layer elastic-plastic rod located on the elastic base,with a compressibly physical nonlinear core,has been studied.The mechanical response of the designed three-layer elements consisting of two bearing layers and a core has been examined.The complicated problem about curving of the three-layer rod located on the elastic base has been solved.The convergence of the proposed method of elastic solutions is examined to convince that the solution is acceptable.The calculated results indicate that the plasticity and physical nonlinearity of materials have a great influence on the deformation of the sandwich rod on the elastic basis.

  11. Editorial: Sandwiched Between Strasbourg and Karlsruhe: EU Fundamental Rights Protection

    NARCIS (Netherlands)

    Reestman, J.H.; Besselink, L.

    2016-01-01

    Starting out from the notion of the `Verfassungsgerichtsverbund´, coined by the President Vosskuhle of the German Federal Constitutional Court, this contribution sketches the manner in which the European Court of Justice operates, sandwiched in between the European Court of Human Rights that sets a

  12. Electrowetting-driven oscillating drops sandwiched between two substrates

    NARCIS (Netherlands)

    Mampallil, Dileep; Eral, H.B.; Staicu, A.D.; Mugele, F.; Ende, van den D.

    2013-01-01

    Drops sandwiched between two substrates are often found in lab-on-chip devices based on digital microfluidics. We excite azimuthal oscillations of such drops by periodically modulating the contact line via ac electrowetting. By tuning the frequency of the applied voltage, several shape modes can be

  13. Dielectrophoretic behaviours of microdroplet sandwiched between LN substrates.

    Science.gov (United States)

    Chen, Lipin; Li, Shaobei; Fan, Bolin; Yan, Wenbo; Wang, Donghui; Shi, Lihong; Chen, Hongjian; Ban, Dechao; Sun, Shihao

    2016-07-07

    We demonstrate a sandwich configuration for microfluidic manipulation in LiNbO3 platform based on photovoltaic effect, and the behaviours of dielectric microdroplet under this sandwich configuration are investigated. It is found that the microdroplet can generate in the form of liquid bridge inside the LiNbO3-based sandwich structure under the governing dielectrophoretic force, and the dynamic process of microdroplet generation highly depends on the substrate combinations. Dynamic features found for different combinations are explained by the different electrostatic field distribution basing on the finite-element simulation results. Moreover, the electrostatic field required by the microdroplet generation is estimated through meniscus evolution and it is found in good agreement with the simulated electrostatic field inside the sandwich gap. Several kinds of microdroplet manipulations are attempted in this work. We suggest that the local dielectrophoretic force acting on the microdroplet depends on the distribution of the accumulated irradiation dosage. Without using any additional pumping or jetting actuator, the microdroplet can be step-moved, deformed or patterned by the inconsecutive dot-irradiation scheme, as well as elastically stretched out and back or smoothly guided in a designed pass by the consecutive line-irradiation scheme.

  14. Application of Load Carrying Sandwich Elements in Wind Turbine Blades

    DEFF Research Database (Denmark)

    Jensen, Jacob Fisker; Schultz, Jacob Pagh; Berggreen, Carl Christian

    2005-01-01

    . For a single skin design, buckling is critical compared to other design criterions. By introducing sandwich, a significant weight reduction and increased buckling capacity is obtained. Tower clearance now becomes critical. Proper choice of core material and thickness is important to prevent face wrinkling...

  15. Effect of Physical Nonlinearity on Local Buckling in Sandwich Beams

    NARCIS (Netherlands)

    Koissin, Vitaly; Shipsha, Andrey; Skvortsov, Vitaly

    2010-01-01

    This article deals with experimental, theoretical, and FE characterization of the local buckling in foam-core sandwich beams. In the theoretical approach, this phenomena is considered in a periodic formulation (unbounded wrinkle wave); a nonlinear stress—strain response of the face material is accou

  16. Damage Tolerance of Sandwich Plates With Debonded Face Sheets

    Science.gov (United States)

    Sankar, Bhavani V.

    2001-01-01

    A nonlinear finite element analysis was performed to simulate axial compression of sandwich beams with debonded face sheets. The load - end-shortening diagrams were generated for a variety of specimens used in a previous experimental study. The energy release rate at the crack tip was computed using the J-integral, and plotted as a function of the load. A detailed stress analysis was performed and the critical stresses in the face sheet and the core were computed. The core was also modeled as an isotropic elastic-perfectly plastic material and a nonlinear post buckling analysis was performed. A Graeco-Latin factorial plan was used to study the effects of debond length, face sheet and core thicknesses, and core density on the load carrying capacity of the sandwich composite. It has been found that a linear buckling analysis is inadequate in determining the maximum load a debonded sandwich beam can carry. A nonlinear post-buckling analysis combined with an elastoplastic model of the core is required to predict the compression behavior of debonded sandwich beams.

  17. Bending moment of galvanized iron glass fiber sandwich panel

    Directory of Open Access Journals (Sweden)

    Gurustal Somnath Swamy

    2016-05-01

    Full Text Available The main objective of this project is to prepare a laminated with Galvanized iron thickness fractions, fiber volume fractions and orientation in the layers of GF were fabricated by hand lay-up method and evaluated for their bending moment properties of the sandwich panel using universal testing machine. This paper theoretically calculates the bending behavior of sandwich panel. The recent need to develop a new range of materials has resulted in the development of high performance lightweight composites with excellent properties. Metal– composite systems consist of alternating layers of metal and fiber-reinforced polymer composites which are bonded by an adhesive. Sandwich beams were tested under Air Bending. Stress-strain and stress-displacement were recorded by using AIMIL UTM. The beam face sheets exhibited a softening non-linearity on the bending side. Experimental results were in good agreement with predictions from simple models. On an overall basis, the sandwich panel exhibited better bending moment performance than the monolithic galvanized iron

  18. The elastic response of sandwich structures to local loading

    NARCIS (Netherlands)

    Koysin, V.; Skvortsov, Vitaly; Krahmalev, Sergey; Shipsha, Andrey

    2004-01-01

    The paper addresses the elastic response of sandwich panels to local static and dynamic loading. The bottom face is assumed to be clamped, so that the overall bending is eliminated. The governing equations are derived using the static Lamé equations for the core and the thin plate Kirchoff–Love

  19. Multiscale Finite-Element Modeling of Sandwich Honeycomb Composite Structures

    Directory of Open Access Journals (Sweden)

    Yu. I. Dimitrienko

    2014-01-01

    Full Text Available The paper presents a developed multi-scale model of sandwich honeycomb structures. The model allows us both to calculate effective elastic-strength characteristics of honeycomb and forced covering of sandwich, and to find a 3D stress-strain state of structures using the threedimensional elastic theory for non- homogeneous media. On the basis of finite element analysis it is shown, that under four-point bending the maximal value of bending and shear stresses in the sandwich honeycomb structures are realized in the zone of applied force and plate support. Here the local stress maxima approximately 2-3 times exceed the “engineering” theoretical plate values of bending and shear stresses in the middle of panel. It is established that at tests for fourpoint bending there is a failure of the honeycomb sandwich panels because of the local adhesion failure rather than because of the covering exfoliation off the honeycomb core in the middle of panel.

  20. Fatigue failure of sandwich beams with face sheet wrinkle defects

    DEFF Research Database (Denmark)

    Leong, Martin Klitgaard; Hvejsel, C.F.; Thomsen, Ole Thybo

    2012-01-01

    This paper presents experimental fatigue results for GFRP face sheet/balsa core sandwich beams with face sheet wrinkle defects, subjected to fully reversed in-plane fatigue loading. An estimate of the fatigue design limit is presented, based on static test results, finite element analyses...

  1. Dielectrophoretic behaviours of microdroplet sandwiched between LN substrates

    Science.gov (United States)

    Chen, Lipin; Li, Shaobei; Fan, Bolin; Yan, Wenbo; Wang, Donghui; Shi, Lihong; Chen, Hongjian; Ban, Dechao; Sun, Shihao

    2016-07-01

    We demonstrate a sandwich configuration for microfluidic manipulation in LiNbO3 platform based on photovoltaic effect, and the behaviours of dielectric microdroplet under this sandwich configuration are investigated. It is found that the microdroplet can generate in the form of liquid bridge inside the LiNbO3-based sandwich structure under the governing dielectrophoretic force, and the dynamic process of microdroplet generation highly depends on the substrate combinations. Dynamic features found for different combinations are explained by the different electrostatic field distribution basing on the finite-element simulation results. Moreover, the electrostatic field required by the microdroplet generation is estimated through meniscus evolution and it is found in good agreement with the simulated electrostatic field inside the sandwich gap. Several kinds of microdroplet manipulations are attempted in this work. We suggest that the local dielectrophoretic force acting on the microdroplet depends on the distribution of the accumulated irradiation dosage. Without using any additional pumping or jetting actuator, the microdroplet can be step-moved, deformed or patterned by the inconsecutive dot-irradiation scheme, as well as elastically stretched out and back or smoothly guided in a designed pass by the consecutive line-irradiation scheme.

  2. Low-Velocity Impact on Composite Sandwich Plates

    Science.gov (United States)

    1996-07-01

    plate and correct for this error. 3.4 One- and Two-Degree of Freedom Models A single degree of freedom system (figure 3-3a) was used by Caprino et al...Composite Materials, Vol. 26, No. 10: 1523-1535 (1992). 211) Caprino , G., and Teti, R. "Impact and post-impact behavior of foam core sandwich

  3. Fluid Structure Interaction Effect on Sandwich Composite Structures

    Science.gov (United States)

    2011-09-01

    14. SUBJECT TERMS Fluid Structure Interaction, FSI, composite, balsa, low velocity impact, sandwich composites, VARTM , Vacuum Assisted Resin Transfer...11 1. Vacuum Assisted Resin Transfer Molding ( VARTM ) ...................11 2. Procedure...required equipment for VARTM composite production. ..............10 Figure 4. VARTM Lay-up (From [8

  4. Effect of microencapsulated phase change material in sandwich panels

    Energy Technology Data Exchange (ETDEWEB)

    Castellon, Cecilia; Medrano, Marc; Roca, Joan; Cabeza, Luisa F. [GREA Innovacio Concurrent, Edifici CREA, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain); Navarro, Maria E.; Fernandez, Ana I. [Departamento de Ciencias de los Materiales e Ingenieria Metalurgica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Lazaro, Ana; Zalba, Belen [Instituto de Investigacion en Ingenieria de Aragon, I3A, Grupo de Ingenieria Termica y Sistemas Energeticos (GITSE), Dpto. Ingenieria Mecanica, Area de Maquinas y Motores Termicos, Universidad de Zaragoza, Campus Politecnico Rio Ebro, Edificio ' ' Agustin de Betancourt,' ' Maria de Luna s/n, 50018 Zaragoza (Spain)

    2010-10-15

    Sandwich panels are a good option as building materials, as they offer excellent characteristics in a modular system. The goal of this study was to demonstrate the feasibility of using the microencapsulated PCM (Micronal BASF) in sandwich panels to increase their thermal inertia and to reduce the energy demand of the final buildings. In this paper, to manufacture the sandwich panel with microencapsulated PCM three different methods were tested. In case 1, the PCM was added mixing the microencapsulated PCM with one of the components of the polyurethane. In the other two cases, the PCM was added either a step before (case 2) or a step after (case 3) to the addition of the polyurethane to the metal sheets. The results show that in case 1 the effect of PCM was overlapped by a possible increase in thermal conductivity, but an increase of thermal inertia was found in case 3. In case 2, different results were obtained due to the poor distribution of the PCM. Some samples showed the effect of the PCM (higher thermal inertia), and other samples results were similar to the conventional sandwich panel. In both cases (2 and 3), it is required to industrialize the process to improve the results. (author)

  5. Dynamic Behaviour of Concrete Sandwich Panel under Blast Loading

    Directory of Open Access Journals (Sweden)

    Dong Yongxiang

    2009-01-01

    Full Text Available Surface contact explosion experiments were performed to study the dynamic behaviour of concrete sandwich panel subjected to blast loading. Experimental results have shown that there are four damage modes explosion cratering, scabbing of the backside, radial cracking induced failure, and circumferential cracking induced failure. It also illustrates that different foam materials sandwiched in the multi-layered medium have an important effect on damage patterns. Due to the foam material, the stress peak decreases one order of magnitude and the duration is more than four times that of the panel without the soft layer by numerical simulation. Additionally, the multi layered medium with concrete foam demonstrates the favourable protective property compared with that of aluminum foam. Meanwhile, the optimal analysis of the thickness of the foam material in the sandwich panel was performed in terms of experimental and numerical analyseis. The proper thickness proportion of soft layer is about 20 percent to the total thickness of sandwich panel under the conditions in this study.Defence Science Journal, 2009, 59(1, pp.22-29, DOI:http://dx.doi.org/10.14429/dsj.59.1480  

  6. Methods for Assessing Honeycomb Sandwich Panel Wrinkling Failures

    Science.gov (United States)

    Zalewski, Bart F.; Dial, William B.; Bednarcyk, Brett A.

    2012-01-01

    Efficient closed-form methods for predicting the facesheet wrinkling failure mode in sandwich panels are assessed. Comparisons were made with finite element model predictions for facesheet wrinkling, and a validated closed-form method was implemented in the HyperSizer structure sizing software.

  7. Flexural Strength of Functionally Graded Nanotube Reinforced Sandwich Spherical Panel

    Science.gov (United States)

    Mahapatra, Trupti R.; Mehar, Kulmani; Panda, Subrata K.; Dewangan, S.; Dash, Sushmita

    2017-02-01

    The flexural behaviour of the functionally graded sandwich spherical panel under uniform thermal environment has been investigated in the present work. The face sheets of the sandwich structure are made by the functionally graded carbon nanotube reinforced material and the core face is made by the isotropic and homogeneous material. The material properties of both the fiber and matrix are assumed to be temperature dependent. The sandwich panel model is developed in the framework of the first order shear deformation theory and the governing equation of motion is derived using the variational principle. For the discretization purpose a suitable shell element has been employed from the ANSYS library and the responses are computed using a parametric design language (APDL) coding. The performance and accuracy of the developed model has been established through the convergence and validation by comparing the obtained results with previously published results. Finally, the influence of different geometrical parameters and material properties on the flexural behaviour of the sandwich spherical panel in thermal environment has been investigated through various numerical illustrations and discussed in details.

  8. Effect of Physical Nonlinearity on Local Buckling in Sandwich Beams

    NARCIS (Netherlands)

    Koysin, V.; Shipsha, Andrey; Skvortsov, Vitaly

    2010-01-01

    This article deals with experimental, theoretical, and FE characterization of the local buckling in foam-core sandwich beams. In the theoretical approach, this phenomena is considered in a periodic formulation (unbounded wrinkle wave); a nonlinear stress—strain response of the face material is accou

  9. Damage tolerance of a composite sandwich with interleaved foam core

    Science.gov (United States)

    Ishai, Ori; Hiel, Clement

    1992-01-01

    A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to low-velocity drop-weight impacts as well as high velocity ballistic impacts. The performance of the interleaved core sandwich panels was characterized by localized skin damage and minor cracking of the core. Residual compressive strength (RCS) of the skin, which was derived from flexural test, shows the expected trend of decreasing with increasing size of the damage, impact energy, and velocity. In the case of skin damage, RCS values of around 50 percent of the virgin interleaved reference were obtained at the upper impact energy range. Based on the similarity between low-velocity and ballistic-impact effects, it was concluded that impact energy is the main variable controlling damage and residual strength, where as velocity plays a minor role.

  10. Modular container assembled from fiber reinforced thermoplastic sandwich panels

    Science.gov (United States)

    Donnelly, Mathew William; Kasoff, William Andrew; Mcculloch, Patrick Carl; Williams, Frederick Truman

    2007-12-25

    An improved, load bearing, modular design container structure assembled from thermoformed FRTP sandwich panels in which is utilized the unique core-skin edge configuration of the present invention in consideration of improved load bearing performance, improved useful load volume, reduced manufacturing costs, structural weight savings, impact and damage tolerance and repair and replace issues.

  11. Flexural Behavior of Aluminum Honeycomb Core Sandwich Structure

    Science.gov (United States)

    Matta, Vidyasagar; Kumar, J. Suresh; Venkataraviteja, Duddu; Reddy, Guggulla Bharath Kumar

    2017-05-01

    This project is concerned with the fabrication and flexural testing of aluminium honey comb sandwich structure which is a special case of composite materials that is fabricated by attaching two thin but stiff skins to a light weight but thick core. The core material is normally low density material but its high thickness provide the sandwich composite with high bonding stiffness. Honeycomb core are classified into two types based on the materials and structures. Hexagonal shape has a unique properties i.e has more bonding strength and less formation time based on the cell size and sheet thickness. Sandwich structure exhibit different properties such as high load bearing capacity at low weight and has excellent thermal insulation. By considering the above properties it has tendency to minimize the structural problem. So honey comb sandwich structure is choosed. The core structure has a different applications such as aircraft, ship interiors, construction industries. As there is no proper research on strength characteristics of sandwich structure. So, we use light weight material to desire the strength. There are different parameters involved in this structure i.e cell size, sheet thickness and core height. In this project we considered 3 level of comparison among the 3 different parameters cell size of 4, 6 and 8 mm, sheet thickness of 0.3, 0.5 and 0.7 mm, and core height of 20,25 and 30 mm. In order to reduce the number of experiment we use taguchi design of experiment, and we select the L8 orthogonal array is the best array for this type of situation, which clearly identifies the parameters by independent of material weight to support this we add the minitab software, to identify the main effective plots and regression equation which involves the individual response and corresponding parameters. Aluminium material is used for the fabrication of Honeycomb sandwich structure among the various grades of aluminium we consider the AL6061 which is light weight material

  12. Primary hepatocyte culture in collagen gel mixture and collagen sandwich

    Institute of Scientific and Technical Information of China (English)

    Ying-Jie Wang; Hong-Ling Liu; Hai-Tao Guo; Hong-Wei Wen; Jun Liu

    2004-01-01

    AIM: To explore the methods of hepatocytes culture in a collagen gel mixture or between double layers of collagen sandwich configuration and to examine the functional and cytomorphological characteristics of cultured hepatocytes.METHODS: A two-step collagenase perfusion technique was used to isolate the hepatocytes from Wistar rats or newborn Chinese experimental piglets. The isolated hepatocytes were cultured in a collagen gel mixture or between double layers of collagen sandwich configuration respectively. The former was that rat hepatocytes were mixed with type I rat tail collagen solution till gelled, and the medium was added onto the gel. The latter was that swine hepatocytes were seeded on a plate precoated with collagen gel for 24 h, then another layer of collagen gel was overlaid, resulting in a sandwich configuration. The cytomorphological characteristics, albumin secretion, and LDH-release of the hepatocytes cultured in these two models were examined.RESULTS: Freshly isolated rat hepatocytes were successfully mixed and fixed in collagen gel, and cultured in the gel condition. During the culture period, the urea synthesized and secreted by rat hepatocytes was detected throughout the period. Likewise, newborn experimental piglet hepatocytes were successfully fixed between the double layers of collagen gel, forming a sandwich configuration.Within a week of culture, the albumin secreted by swine hepatocytes was detected by SDS/PAGE analysis. The typical cytomorphological characteristics of the hepatocytes cultured by the above two culture models were found under a phasecontrast microscope. There was little LDH-release during the culture period.CONCLUSION: Both collagen gel mixture and double layers of collagen sandwich configuration can provide cultural conditions much closer to in vivoenvironment, and are helpful for maintaining specific hepatic fiJnctions and cytomorphological characteristics. A collagen gel mixture culture may be more eligible for the

  13. Cascaded-systems analysis of sandwich x-ray detectors

    Science.gov (United States)

    Kim, D. W.; Kim, J.; Yun, S.; Youn, H.; Kim, H. K.

    2016-12-01

    Active sandwich-like multilayer detectors have been developed, and their potential for motion-artifact-free dual-energy x-ray imaging at a single exposure has been demonstrated in the material decomposition context. Since the sandwich detector uses the x-ray beam transmittance through the front layer, direct x-ray interaction within photodiodes in the front layer is unavoidable, and which can increase noise in the front detector images. Similar direct x-ray interaction can also occur in the rear detector layer. To obtain a better contrast performance, an additional filter layer can be placed between the two detector layers. However, this filter layer can increase adversely noise in images obtained from the rear detector layer by reducing the number of x-ray photons reaching it. A theoretical model, which can describe the signal-to-noise performance of the sandwich detector as functions of various design parameters, has been developed by using a linear cascaded-systems theory. From the cascaded-systems analysis, the direct x-ray interaction increases noise at the high spatial frequencies where the number of secondary quanta lessens. The intermediate filter layer enhances the contribution of additive electronic noise in the overall noise performance of the rear detector layer. The detailed cascaded-systems analysis on the x-ray sandwich detectors are reported in comparisons with the measured noise-power spectra and detective quantum efficiencies. The developed model will be useful for a better design and practical use of a sandwich detector for single-shot dual-energy imaging.

  14. The Planar Sandwich and Other 1D Planar Heat Flow Test Problems in ExactPack

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, Jr., Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-24

    This report documents the implementation of several related 1D heat flow problems in the verification package ExactPack [1]. In particular, the planar sandwich class defined in Ref. [2], as well as the classes PlanarSandwichHot, PlanarSandwichHalf, and other generalizations of the planar sandwich problem, are defined and documented here. A rather general treatment of 1D heat flow is presented, whose main results have been implemented in the class Rod1D. All planar sandwich classes are derived from the parent class Rod1D.

  15. Mechanical Response of All-composite Pyramidal Lattice Truss Core Sandwich Structures

    Institute of Scientific and Technical Information of China (English)

    Ming Li; Linzhi Wu; Li Ma; Bing Wang; Zhengxi Guan

    2011-01-01

    The mechanical performance of an all-composite pyramidal lattice truss core sandwich structure was investigated both theoretically and experimentally. Sandwich structures were fabricated with a hot compression molding method using carbon fiber reinforced composite T700/3234. The out-of-plane compression and shear tests were conducted. Experimental results showed that the all-composite pyramidal lattice truss core sandwich structures were more weight efficient than other metallic lattice truss core sandwich structures. Failure modes revealed that node rupture dominated the mechanical behavior of sandwich structures.

  16. Elastic stability of superplastically formed/diffusion-bonded orthogonally corrugated core sandwich plates

    Science.gov (United States)

    Ko, W. L.

    1980-01-01

    The paper concerns the elastic buckling behavior of a newly developed superplastically formed/diffusion-bonded (SPF/DB) orthogonally corrugated core sandwich plate. Uniaxial buckling loads were calculated for this type of sandwich plate with simply supported edges by using orthotropic sandwich plate theory. The buckling behavior of this sandwich plate was then compared with that of an SPF/DB unidirectionally corrugated core sandwich plate under conditions of equal structural density. It was found that the buckling load for the former was considerably higher than that of the latter.

  17. Physico-chemical Stability of MabThera Drug-product Solution for Subcutaneous Injection under in-use Conditions with Different Administration Materials.

    Science.gov (United States)

    Mueller, Claudia; Dietel, Elke; Heynen, Severin R; Nalenz, Heiko; Goldbach, Pierre; Mahler, Hanns-Christian; Schmidt, Johannes; Grauschopf, Ulla; Schoenhamnmer, Karin

    2015-01-01

    MabThera is an essential component of the standard-of-care regimens in the treatment of non-Hodgkin lymphoma and Chronic Lymphatic Leukemia. MabThera for subcutaneous injection is a novel line extension that has been approved by the European Medicines Agency for the treatment of patients with follicular lymphoma and diffuse large B-cell lymphoma. This study aimed to evaluate in-use stability data of MabThera subcutaneous drug-product solution in single-use syringes for subcutaneous administration according to the European Medicines Agency guideline. The drug-product solution was exposed to material contact surfaces of five different administration setups commonly used in subcutaneous drug delivery. MabThera subcutaneous was transferred under aseptic conditions into polypropylene and polycarbonate syringes and stored for 1, 2, and 4 weeks at 2°C to 8°C followed by 24 hours at 30°C. After storage, subcutaneous administration was simulated and MabThera subcutaneous drug-product solution quality attributes were evaluated by using compendial physico-chemical tests, as well as suitable and validated molecule- and formulation-specific analytical methods. MabThera subcutaneous vials were treated and analyzed in parallel. The physico-chemical results of MabThera subcutaneous in the different setups were comparable to the control for all timepoints. No change in drug-product quality after storage and simulated administration was found compared to the control. However, since single-dose products do not contain preservatives, microbial contamination and growth needs to be avoided and product sterility needs to be ensured. The results showed that MabThera subcutaneous remains compatible and stable, from a physico-chemical perspective, for up to 4 weeks at 2°C to 8°C followed by 24 hours at 30°C with the contact materials tested in this study. In order to avoid and minimize microbial growth, MabThera subcutaneous should be used immediately after removal from the original

  18. mAb CZP-315.D9: An Antirecombinant Cruzipain Monoclonal Antibody That Specifically Labels the Reservosomes of Trypanosoma cruzi Epimastigotes

    Directory of Open Access Journals (Sweden)

    Cassiano Martin Batista

    2014-01-01

    Full Text Available Reservosomes are large round vesicles located at the posterior end of epimastigote forms of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. They are the specific end organelles of the endocytosis pathway of T. cruzi, and they play key roles in nutrient uptake and cell differentiation. These lysosome-like organelles accumulate ingested macromolecules and contain large amounts of a major cysteine proteinase (cruzipain or GP57/51 protein. Aim of this study was to produce a monoclonal antibody (mAb against a recombinant T. cruzi cruzipain (TcCruzipain that specifically labels the reservosomes. BALB/c mice were immunized with purified recombinant TcCruzipain to obtain the mAb. After fusion of isolated splenocytes with myeloma cells and screening, a mAb was obtained by limiting dilution and characterized by capture ELISA. We report here the production of a kappa-positive monoclonal IgG antibody (mAb CZP-315.D9 that recognizes recombinant TcCruzipain. This mAb binds preferentially to a protein with a molecular weight of about 50 kDa on western blots and specifically labels reservosomes by immunofluorescence and transmission electron microscopy. The monoclonal CZP-315.D9 constitutes a potentially powerful marker for use in studies on the function of reservosomes of T. cruzi.

  19. Targeting glioblastoma with NK cells and mAb against NG2/CSPG4 prolongs animal survival.

    Science.gov (United States)

    Poli, Aurélie; Wang, Jian; Domingues, Olivia; Planagumà, Jesús; Yan, Tao; Rygh, Cecilie Brekke; Skaftnesmo, Kai Ove; Thorsen, Frits; McCormack, Emmet; Hentges, François; Pedersen, Paal Henning; Zimmer, Jacques; Enger, Per Øyvind; Chekenya, Martha

    2013-09-01

    Glioblastoma (GBM) is the most malignant brain tumor where patients' survival is only 14.6 months, despite multimodal therapy with debulking surgery, concurrent chemotherapy and radiotherapy. There is an urgent, unmet need for novel, effective therapeutic strategies for this devastating disease. Although several immunotherapies are under development for the treatment of GBM patients, the use of natural killer (NK) cells is still marginal despite this being a promising approach to treat cancer. In regard of our knowledge on the role of NG2/CSPG4 in promoting GBM aggressiveness we investigated the potential of an innovative immunotherapeutic strategy combining mAb9.2.27 against NG2/CSPG4 and NK cells in preclinical animal models of GBM. Multiple immune escape mechanisms maintain the tumor microenvironment in an anti-inflammatory state to promote tumor growth, however, the distinct roles of resident microglia versus recruited macrophages is not elucidated. We hypothesized that exploiting the cytokine release capabilities of activated (NK) cells to reverse the anti-inflammatory axis combined with mAb9.2.27 targeting the NG2/CSPG4 may favor tumor destruction by editing pro-GBM immune responses. Combination treatment with NK+mAb9.2.27 diminished tumor growth that was associated with reduced tumor proliferation, increased cellular apoptosis and prolonged survival compared to vehicle and monotherapy controls. The therapeutic efficacy was mediated by recruitment of CCR2low macrophages into the tumor microenvironment, increased ED1 and MHC class II expression on microglia that might render them competent for GBM antigen presentation, as well as elevated IFN-γ and TNF-α levels in the cerebrospinal fluid compared to controls. Depletion of systemic macrophages by liposome-encapsulated clodronate decreased the CCR2low macrophages recruited to the brain and abolished the beneficial outcomes. Moreover, mAb9.2.27 reversed tumor-promoting effects of patient-derived tumor

  20. Interface fatigue crack propagation in sandwich X-joints – Part I: Experiments

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Berggreen, Christian

    2013-01-01

    In this study, face/core fatigue crack growth in sandwich X-joints is investigated numerically and experimentally. The work presented here covers Part I of the study which includes an experimental investigation of fatigue crack growth in sandwich X-joints and characterization of the face/core int......In this study, face/core fatigue crack growth in sandwich X-joints is investigated numerically and experimentally. The work presented here covers Part I of the study which includes an experimental investigation of fatigue crack growth in sandwich X-joints and characterization of the face....../core interface of the joints. Sandwich tear test specimens with a face/core debond representing a debonded sandwich X-joint were tested under cyclic loading. Fatigue tests were conducted on the sandwich tear test specimens with H45, H100 and H250 PVC cores and glass/polyester face sheets. The Digital Image...

  1. Compressive and shear buckling analysis of metal matrix composite sandwich panels under different thermal environments

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1993-01-01

    Combined inplane compressive and shear buckling analysis was conducted on flat rectangular sandwich panels using the Raleigh-Ritz minimum energy method with a consideration of transverse shear effect of the sandwich core. The sandwich panels were fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that slightly slender (along unidirectional compressive loading axis) rectangular sandwich panels have the most desirable stiffness-to-weight ratios for aerospace structural applications; the degradation of buckling strength of sandwich panels with rising temperature is faster in shear than in compression; and the fiber orientation of the face sheets for optimum combined-load buckling strength of sandwich panels is a strong function of both loading condition and panel aspect ratio. Under the same specific weight and panel aspect ratio, a sandwich panel with metal matrix composite face sheets has much higher buckling strength than one having monolithic face sheets.

  2. Outbreak of Salmonella indiana associated with egg mayonnaise sandwiches at an acute NHS hospital.

    Science.gov (United States)

    Mason, B W; Williams, N; Salmon, R L; Lewis, A; Price, J; Johnston, K M; Trott, R M

    2001-12-01

    An outbreak of Salmonella indiana infection in December 2000 affected 17 staff, relatives and patients at an acute NHS Hospital in Swansea. Epidemiological investigation identified egg mayonnaise sandwiches as the vehicle of infection. It was not possible to definitively determine the source of the infection or how the prepared sandwiches became contaminated. The most likely explanation was a pasteurisation failure of a batch of the egg roll used to make these sandwiches. Sandwiches are the most frequently identified vehicle of infection in foodborne outbreaks of salmonella infection in hospitals in England and Wales. The process of sandwich preparation has inherent risks because it involves considerable handling of food, which is consumed without further cooking. Care is required in all stages of preparation including the sourcing of materials used to produce the sandwiches. NHS Trusts should review their Hazard Analysis Critical Control Point plans for sandwich production.

  3. System visualization of integrated biofuels and high value chemicals developed within the MacroAlgaeBiorefinery (MAB3) project

    DEFF Research Database (Denmark)

    Seghetta, Michele; Hasler, Berit; Bastianoni, Simone

    MacroAlgaeBiorefinery (MAB3) may functions as production platform and raw material supplier for future sustainable production chains of biofuels and high value chemicals. Biofuels are interesting energy source but challenges in terms of the composition of the biomass and resulting energy...... efficiencies has to be compensated for to make the biofuel prices competitive in replacing fossil fuel. Since it is difficult to increase the yield of the single biorefinery, the overall system productivity can be improved integrating different sub-systems. In this study, macroalgae cultivation in Denmark...... is integrated with a biogas biorefinery, a bioethanol biorefinery and a fish feed industry. The modeled system is able to adapt itself to different amount and quality of feedstock and to maximize valuable outputs (e.g. bio-fuels and chemical). Macroalgae are harvested and utilized as feedstock in bioethanol...

  4. Humanized mAb H22 binds the human high affinity Fc receptor for IgG (FcgammaRI), blocks phagocytosis, and modulates receptor expression.

    Science.gov (United States)

    Wallace, P K; Keler, T; Coleman, K; Fisher, J; Vitale, L; Graziano, R F; Guyre, P M; Fanger, M W

    1997-10-01

    About 10-15% of patients with immune thrombocytopenic purpura (ITP) cannot be controlled by corticosteroid therapy and splenectomy. For these patients treatment with high-dose IVIgG induces partial or complete responses. The clinical benefits of IVIgG could be due to blockade of Fc receptors for IgG (FcgammaR), because several model systems clearly show that functional FcgammaR are essential for establishment of ITP and related diseases. However, the specific contributions of the three individual classes of FcgammaR remain to be more completely defined. Recently monoclonal antibody (mAb) H22, which recognizes an epitope on FcgammaRI (CD64) outside the ligand binding domain, was humanized by grafting its complementarity determining regions onto human IgG1 constant domains. Because FcgammaRI has a high affinity for human IgG1 antibodies, we predicted mAb H22 would also bind to FcgammaRI through its Fc domain and block FcgammaRI-mediated phagocytosis. These studies demonstrate that mAb H22 blocked phagocytosis of opsonized red blood cells 1000 times more effectively than an irrelevant IgG. Moreover, cross-linking FcgammaRI with mAb H22 rapidly down-modulated FcgammaRI expression on monocytes without affecting other surface antigens. We conclude that because mAb H22 is a humanized mAb that blocks the FcgammaRI ligand binding domain and down-modulates FcgammaRI expression, it is a particularly good candidate for evaluating the role of FcgammaRI in patients with ITP.

  5. Combining NK cells and mAb9.2.27 to combat NG2-dependent and anti-inflammatory signals in glioblastoma.

    Science.gov (United States)

    Kmiecik, Justyna; Gras Navarro, Andrea; Poli, Aurelie; Planagumà, Jesús Planagumà; Zimmer, Jacques; Chekenya, Martha

    2014-01-01

    Glioblastoma is a deadly brain cancer with limited treatment options. Targeting chondroitin sulfate proteoglycan 4 (CSPG4, best known as NG2) with the monoclonal antibody mAb9.2.27 and activated natural killer (NK) cells abrogated the tumor growth and prolonged the survival of glioblastoma-bearing animals by favoring the establishment of a pro-inflammatory microenvironment. The combination of NK cells and mAb9.2.27 recruited ED1(+)CCR2(low) macrophages that stimulated ED1(+)ED2(low)MHCII(high) microglial cells to exert robust cytotoxicity. Our findings demonstrate the therapeutic potential of targeting salient tumor associated-antigens.

  6. Impact load mitigation in sandwich beams using local resonators

    CERN Document Server

    Sharma, B

    2015-01-01

    Dynamic response of sandwich beams with resonators embedded in the cores subjected to impact loads is studied. Using finite element models the effectiveness of various local resonator frequencies under a given impact load is compared to the behavior of an equivalent mass beam. It is shown that addition of appropriately chosen local resonators into the sandwich beam is an effective method of improving its flexural bending behavior under impact loads. The effect of a given local resonance frequency under different impact load durations is also studied. It is demonstrated that the choice of appropriate local resonance frequency depends on the impact duration. Further, by performing transverse impact experiments, the finite element models are verified and the advantage of using internal resonators under impact loading conditions is demonstrated.

  7. Preserving entanglement under decoherence and sandwiching all separable states

    CERN Document Server

    Lockhart, R B; Lockhart, Robert; Steiner, Michael

    2000-01-01

    Every entangled state can be perturbed, for instance by decoherence, and stay entangled. For a large class of pure entangled states, we show how large the perturbation can be. Our class includes all pure bipartite and all maximally entangled states. For an entangled state, E, the constucted neighborhood of entangled states is the region outside two parallel hyperplanes, which sandwich the set of all separable states. The states for which these neighborhoods are largest are the maximally entangled ones. As the number of particles, or the dimensions of the Hilbert spaces for two of the particles increases, the distance between two of the hyperplanes which sandwich the separable states goes to zero. It is easy to decide if a state Q is in the neighborhood of entangled states we construct for an entangled state E. One merely has to check if the trace of EQ is greater than a constant which depends upon E and which we determine.

  8. Natural fabric sandwich laminate composites: development and investigation

    Indian Academy of Sciences (India)

    C K ARVINDA PANDIAN; H SIDDHI JAILANI; A RAJADURAI

    2017-02-01

    In this work, eco-friendly natural fabric sandwich laminate (NFSL) composites are formulated using jute and linen-fabric-reinforced epoxy with different layer ratios (5:0, 4:1, 3:2, 2:3, 1:4 and 0:5) by hand layup system. Different mechanical attributes (tensile, flexural and impact) of the NFSL composites are quantified. Thermal stability and water absorption behaviour of the NFSL composites are also assessed. A scanning electron microscope (SEM) and optical microscope are used for qualitative analysis of NFSL composites’ interfacial properties. Two layers of jute and three layers of linen sandwich laminate have registered peak values in tensile and impact properties. The five layers of linen laminate composite have exhibited high flexural strength, been proven to have good thermal stability and furthermore shown better water absorption behaviour than any other laminate composites.

  9. Non-linear Behavior of Curved Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian; Jolma, P.; Karjalainen, J. P.;

    2003-01-01

    In this paper the non-linear behavior of curved sandwich panels is investigated both numerically and experimentally. Focus is on various aspects of finite element modeling and calculation procedures. A simply supported, singly curved, CFRP/PVC sandwich panel is analyzed under uniform pressure load...... and results are compared to test data. A novel test arrangement utilizing a water filled cushion to create the uniform pressure load on curved panel specimen is used to obtain the experimental data. The panel is modeled with three different commercial finite element codes. Two implicit and one explicit code...... are used with various element types, modeling approaches and material models. The results show that the theoretical and experimental methods generally show fair agreement in panel non-linear behavior before collapse. It is also shown that special attention to detail has to be taken, because the predicted...

  10. Non-Uniform Compressive Strength of Debonded Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian; Simonsen, Bo Cerup

    2005-01-01

    This article describes the development, validation and application of a FEM based numerical model for prediction of residual strength of damaged sandwich panels. The core of the theoretical method is a newly developed procedure for prediction of the propagation of a face-core debond. As demonstra......This article describes the development, validation and application of a FEM based numerical model for prediction of residual strength of damaged sandwich panels. The core of the theoretical method is a newly developed procedure for prediction of the propagation of a face-core debond.......(2005)., shows that the model is indeed able to predict the failure modes and the residual strength of damaged panels with accuracy sufficient for practical applications. This opens up for a number of important engineering applications, for example risk-based inspection and repair schemes....

  11. Applications of thin-film sandwich crystallization platforms

    Energy Technology Data Exchange (ETDEWEB)

    Axford, Danny, E-mail: danny.axford@diamond.ac.uk; Aller, Pierre; Sanchez-Weatherby, Juan; Sandy, James [Diamond Light Source, Harwell Oxford, Didcot OX11 0DE (United Kingdom)

    2016-03-24

    Crystallization via sandwiches of thin polymer films is presented and discussed. Examples are shown of protein crystallization in, and data collection from, solutions sandwiched between thin polymer films using vapour-diffusion and batch methods. The crystallization platform is optimal for both visualization and in situ data collection, with the need for traditional harvesting being eliminated. In wells constructed from the thinnest plastic and with a minimum of aqueous liquid, flash-cooling to 100 K is possible without significant ice formation and without any degradation in crystal quality. The approach is simple; it utilizes low-cost consumables but yields high-quality data with minimal sample intervention and, with the very low levels of background X-ray scatter that are observed, is optimal for microcrystals.

  12. Development of sandwich dot-ELISA for specific detection of Ochratoxin A and its application on to contaminated cereal grains originating from India

    Directory of Open Access Journals (Sweden)

    M. eVenkataramana

    2015-05-01

    Full Text Available In the present study, generation and characterization of a highly specific monoclonal antibody (mAb against Ochratoxin A (OTA was undertaken. The generated mAb was further used to develop a simple, fast and sensitive sandwich dot-ELISA (s-dot ELISA method for detection of OTA from contaminated food grain samples. The LOD (limit of detetion of the developed ELISA method was determined as 5.0 ng/mL of OTA. Developed method was more specific towards OTA and no cross reactivity was observed with the other tested mycotoxins such as deoxynivalenol, fumonisin B1 or aflatoxin B1. To assess the utility and reliability of the developed method, several field samples of maize, wheat and rice (n=195 collected from different geographical regions of southern Karnataka region of India were evaluated for the OTA occurrence. Seventy two out of 195 samples (19 maize, 38 wheat and 15 rice were found to be contaminated by OTA by s-dot ELISA. The assay results were further co-evaluated with conventional analytical HPLC method. Results of the s-dot ELISA are in concordance with HPLC except for 3 samples that were negative for OTA presence by s-dot ELISA but found positive by HPLC. Although positive by HPLC, the amount of OTA in the three samples was found to be lesser than the accepted levels (>5 µg/kg of OTA presence in cereals. Therefore, in conclusion, the developed s-dot ELISA is a better alternative for routine cereal based food and feed analysis in diagnostic labs to check the presence of OTA over existing conventional culture based, tedious analytical methods.

  13. Production of mono- and polyclonal antibodies to Citrus leprosis virus C2 and their application in triple antibody sandwich ELISA and immunocapture RT-PCR diagnostic assays.

    Science.gov (United States)

    Choudhary, Nandlal; Roy, Avijit; Leon, M G; Wei, G; Nakhla, M K; Levy, L; Brlansky, R H

    2017-05-01

    The newly discovered Citrus leprosis virus cytoplasmic type 2 (CiLV-C2) is one of the causal virus of citrus leprosis disease complex; which leads to substantial loss of citrus production in the states of Meta and Casanare of Colombia. Specific and sensitive detection methods are needed to monitor the dissemination of CiLV-C2 in Colombia, and to prevent introduction of CiLV-C2 to other citrus growing countries. Toward this end, putative coat protein gene (CPG) of CiLV-C2 was amplified from CiLV-C2 infected citrus tissues. The CPG was cloned, expressed and purified a recombinant coat protein of ∼31kDa which used to generate monoclonal antibodies and polyclonal antisera. Four monoclonal antibodies and two polyclonal antisera were selected as being specific following Western blotting. The monoclonal antibody MAb E5 and polyclonal antiserum PAb UF715 were selected testing with an extract of CiLV-C2 infected leaves using triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA). In addition, an immunocapture RT-PCR was standardized using MAb E5 for specific and sensitive detection of CiLV-C2. The standardized TAS-ELISA and IC-RT-PCR were able to detect CiLV-C2 in the extracts of symptomatic citrus leprosis tissues up to the dilutions of 1:160 and 1:2580, respectively. Result demonstrated that CiLV-C2 is present in citrus orchards in Meta and Casanare citrus growing areas of Colombia. TAS-ELISA could be used for routine detection of CiLV-C2, epidemiological studies, and for border inspections for quarantine purposes. IC-RT-PCR could be valuable for CiLV-C2 validation and viral genome analysis.

  14. Sandwich-like Reconstruction of Anterior Skull Base Defects

    Institute of Scientific and Technical Information of China (English)

    Wang Zheng-min; Wang De-hui

    2001-01-01

    Objective: To evaluate the safety and efficacy of new modality of anterior skull base repair,namely sandwich-like reconstruction of anterior skull base defects. Methods: A retrospective analysis of patients who underwent transcranial or transcranial-facial resections of malignant or benign aggressive tumors involving the anterior skull base was conducted in our department. We used the sandwich-like reconstruction, using pedicled pericranial flap, frontal muscle flap and free abdominal adipose tissue between them, to separate of cranial cavity and aerodigest tract and keep the frontal lobes in place following resections of anterior skull base tumors. Results: From October, 1984 to October, 1998, 116 patients underwent transcranial or transcranialfacial approach for the resection of malignant or aggressive benign tumor, and sandwich-like repairs were performed for the anterior skull base defect. 54 (46.6 % ) patients had previous operation, with a maximum of 5 surgeries. The average age of patients was 35.9 years old, ranging form 6 to 73 years old. Forty-eight (41.4%)patients had malignant neoplasmas, and sixty-eight (58.6%) patients had benign aggressive tumors. In our series, with the maximal follow-ups for as long as 14 years, NO one had early failure of the one-stage reconstruction. CSF fluid leakage was not encountered, nor was ascending bacterial meningitis observed. No immediate or delayed prolapse of dura or frontal lobes was observed. Conclusion: We conclude that the sandwich-like reconstruction, using pericranial flap, frontal muscle flap and free abdominal adipose between them, is an extremely safe and effective procedure for the repair of skull base defect, even when tumor extensively involves anterior skull base.

  15. Sandwich-like Reconstruction of Anterior Skull Base Defects

    Institute of Scientific and Technical Information of China (English)

    WangZheng-min,MD; WangDe-hui,MD

    2001-01-01

    Objective:To evaluate the safety and efficacy of new modality of anterior skull base repair,namely sandwich-like reconstruction of anterior skull base defects. Methods : A retrospective analysis of patients who underwent wanscranial or wanscranial-facial resections of malignant or benign aggressive tumors involving the anterior skull base was conducted in our department. We used the sandwich-like reconstruction, using pedicled pericranial flap, frontal muscle flap and free abdominal adipose tissue between them, to separate of cranial cavity and aerodigest tract and keep the frontal lobes in place following resections of anterior skull base tumors. Results: From October, 1984 to October, 1998, 116 patients underwent tmnscranial or tmnscranial-facial approach for the resection of malignant or aggressive benign tumor, and sandwich-like repairs were performed for the anterior skull base defect.54 (46.6%) patients had previous operation, with a maximum of 5 surgeries. The average age of patients was 35.9 years old, ranging form 6 to 73 years old. Forty-eight (41.4%) patients had malignant neoplasmas, and sixty-eight (58.6%) patients had benign aggressive tumors. In our series, with the maximal follow-ups for as long as 14 years, NO one had early failure of the one-stage reconstruction. CSF fluid leakage was not encountered, nor was ascending bacterial meningitis observed. No immediate or delayed prolapse of dura or frontal lobes was observed. Conclusion: We conclude that the sandwich-like reconstruction, using pericranial flap, frontal muscle flap and free abdominal adipose between them, is an extremely safe and effective procedure for the repair of skull base defect, even when tumor extensively involves anterior skull base.

  16. Residual Strength of In-plane Loaded Debonded Sandwich Panels

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Nøkkentved, Alexandros; Berggreen, Carl Christian

    2005-01-01

    Face/core debond damaged sandwich panels exposed to uniform and non-uniform compression loads are studied experimentally. The panel geometry is full-scale rectangular with a centrally located circular prefabricated debond. The results show a considerable strength reduction with increasing debond...... diameter, with the failure mechanisms varying between buckling driven debond propagation and face compression failure for large and small debonds respectively....

  17. Sandwiched R\\'enyi Convergence for Quantum Evolutions

    OpenAIRE

    Müller-Hermes, Alexander; Franca, Daniel Stilck

    2016-01-01

    We study the speed of convergence of a primitive quantum time evolution towards its fixed point in the distance of sandwiched R\\'enyi divergences. For each of these distance measures the convergence is typically exponentially fast and the best exponent is given by a constant (similar to a logarithmic Sobolev constant) depending only on the generator of the time evolution. We establish relations between these constants and the logarithmic Sobolev constants as well as the spectral gap. An impor...

  18. The Generalized Thin-Sandwich Problem and its Local Solvability

    CERN Document Server

    Giulini, D

    1999-01-01

    We consider Einstein Gravity coupled to dynamical matter consisting of a gauge field with any compact gauge group and minimally coupled scalar fields. We investigate the conditions under which a free specification of a spatial field configuration for the total system and its derivative with respect to coordinate-time determines a solution to the field equations (generalized thin-sandwich problem). Sufficient conditions for local solvability (in the space of fields) are established.

  19. An asymptotically exact theory of smart sandwich shells

    CERN Document Server

    Le, Khanh Chau

    2016-01-01

    An asymptotically exact two-dimensional theory of elastic-piezoceramic sandwich shells is derived by the variational-asymptotic method. The error estimation of the constructed theory is given in the energetic norm. As an application, analytical solution to the problem of forced vibration of a circular elastic plate partially covered by two piezoceramic patches with thickness polarization excited by a harmonic voltage is found.

  20. Flexural Behavior of Two-Way Sandwiched Slabs

    OpenAIRE

    Pachpande, Jivan Vilas

    2015-01-01

    This dissertation presents the details of the findings of a study focused on evaluating the structural behavior of three-dimensional (3D) cementitious sandwich panels with Expanded Polystyrene (EPS) foam core for two-way slab applications. In this study, both theoretical and finite element numerical analysis procedures were adopted to predict the performance of such slabs under out-of-plane loading conditions. The results from theoretical and finite element analysis were verified by compariso...

  1. Graphene Sandwiched Mesostructured Li-Ion Battery Electrodes.

    Science.gov (United States)

    Liu, Jinyun; Zheng, Qiye; Goodman, Matthew D; Zhu, Haoyue; Kim, Jinwoo; Krueger, Neil A; Ning, Hailong; Huang, Xingjiu; Liu, Jinhuai; Terrones, Mauricio; Braun, Paul V

    2016-09-01

    A deterministic graphene-sandwiched Li-ion battery electrode consisting of an integrated 3D mesostructure of electrochemically active materials and graphene is presented. As demonstrations, electrodes with active nanomaterials that coat (V2 O5 @graphene@V2 O5 cathode) or are coated by (graphene@Si@graphene anode) graphene are fabricated. These electrodes exhibit high capacities and ultralong cycle lives (the cathode can be cycled over 2000 times with minimal capacity fade).

  2. Double Rosensweig instability in a ferrofluid sandwich structure

    OpenAIRE

    Rannacher, Dirk; Engel, Andreas

    2003-01-01

    We consider a horizontal ferrofluid layer sandwiched between two layers of immiscible non-magnetic fluids. In a sufficiently strong vertical magnetic field the flat interfaces between magnetic and non-magnetic fluids become unstable to the formation of peaks. We theoretically investigate the interplay between these two instabilities for different combinations of the parameters of the fluids and analyze the evolving interfacial patterns. We also estimate the critical magnetic field strength at...

  3. Two-dimensional analysis of shallow sandwich panels

    DEFF Research Database (Denmark)

    Skvortsov, V; Bozhevolnaya, Elena

    2001-01-01

    The shallow singly curved and rectangular in-plane sandwich panels affected by lateral loads are considered. The set of governing equations on the basis of the Timoshenko-Reissner plate theory is derived for these panels in the case of general boundary conditions. Usage of any real boundary condi...... all four edges and for the panel that is simply supported along its curved boundaries and has hinge-like supports along the straight boundaries. (C) 2001 Elsevier Science Ltd. All rights reserved....

  4. Residual Strength of In-plane Loaded Debonded Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian; Simonsen, Bo Cerup

    2005-01-01

    This paper presents a FEM based numerical model for prediction of residual strength of damaged sandwich panels. As demonstrated, the model can predict the maximum load carrying capacity of real-life panels with debond damages, where the failure is governed by face-sheet buckling followed by debond...... growth. Comparison of the theoretical predictions is carried out against a series of largescale experiments described in Lundsgaard-Larsen et al. (2005)...

  5. Sandwich Structured Composites for Aeronautics: Methods of Manufacturing Affecting Some Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Aneta Krzyżak

    2016-01-01

    Full Text Available Sandwich panels are composites which consist of two thin laminate outer skins and lightweight (e.g., honeycomb thick core structure. Owing to the core structure, such composites are distinguished by stiffness. Despite the thickness of the core, sandwich composites are light and have a relatively high flexural strength. These composites have a spatial structure, which affects good thermal insulator properties. Sandwich panels are used in aeronautics, road vehicles, ships, and civil engineering. The mechanical properties of these composites are directly dependent on the properties of sandwich components and method of manufacturing. The paper presents some aspects of technology and its influence on mechanical properties of sandwich structure polymer composites. The sandwiches described in the paper were made by three different methods: hand lay-up, press method, and autoclave use. The samples of sandwiches were tested for failure caused by impact load. Sandwiches prepared in the same way were used for structural analysis of adhesive layer between panels and core. The results of research showed that the method of manufacturing, more precisely the pressure while forming sandwich panels, influences some mechanical properties of sandwich structured polymer composites such as flexural strength, impact strength, and compressive strength.

  6. Impact properties of aluminium - glass fiber reinforced plastics sandwich panels

    Directory of Open Access Journals (Sweden)

    Mathivanan Periasamy

    2012-06-01

    Full Text Available Aluminium - glass fiber reinforced plastics (GFRP sandwich panels are hybrid laminates consisting of GFRP bonded with thin aluminum sheets on either side. Such sandwich materials are increasingly used in airplane and automobile structures. Laminates with varying aluminium thickness fractions, fiber volume fractions and orientation in the layers of GFRP were fabricated by hand lay up method and evaluated for their impact performance by conducting drop weight tests under low velocity impacts. The impact energy required for initiating a crack in the outer aluminium layer as well as the energy required for perforation was recorded. The impact load-time history was also recorded to understand the failure behavior. The damage depth and the damage area were measured to evaluate the impact resistance. Optical photography and scanning electron micrographs were taken to visualize the crack and the damage zone. The bidirectional cross-ply hybrid laminate (CPHL has been found to exhibit better impact performance and damage resistance than the unidirectional hybrid laminate (UDHL. Increase in aluminium thickness fraction (Al tf and fiber volume fraction (Vf resulted in an increase in the impact energy required for cracking and perforation. On an overall basis, the sandwich panels exhibited better impact performance than the monolithic aluminium.

  7. Sandwich-structured hollow fiber membranes for osmotic power generation

    KAUST Repository

    Fu, Feng Jiang

    2015-11-01

    In this work, a novel sandwich-structured hollow fiber membrane has been developed via a specially designed spinneret and optimized spinning conditions. With this specially designed spinneret, the outer layer, which is the most crucial part of the sandwich-structured membrane, is maintained the same as the traditional dual-layer membrane. The inner substrate layer is separated into two layers: (1) an ultra-thin middle layer comprising a high molecular weight polyvinylpyrrolidone (PVP) additive to enhance integration with the outer polybenzimidazole (PBI) selective layer, and (2) an inner-layer to provide strong mechanical strength for the membrane. Experimental results show that a high water permeability and good mechanical strength could be achieved without the expensive post treatment process to remove PVP which was necessary for the dual-layer pressure retarded osmosis (PRO) membranes. By optimizing the composition, the membrane shows a maximum power density of 6.23W/m2 at a hydraulic pressure of 22.0bar when 1M NaCl and 10mM NaCl are used as the draw and feed solutions, respectively. To our best knowledge, this is the best phase inversion hollow fiber membrane with an outer selective PBI layer for osmotic power generation. In addition, this is the first work that shows how to fabricate sandwich-structured hollow fiber membranes for various applications. © 2015 Elsevier B.V.

  8. Sandwiched Rényi divergence satisfies data processing inequality

    Energy Technology Data Exchange (ETDEWEB)

    Beigi, Salman [School of Mathematics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5746, Tehran (Iran, Islamic Republic of)

    2013-12-15

    Sandwiched (quantum) α-Rényi divergence has been recently defined in the independent works of Wilde et al. [“Strong converse for the classical capacity of entanglement-breaking channels,” preprint http://arxiv.org/abs/arXiv:1306.1586 (2013)] and Müller-Lennert et al. [“On quantum Rényi entropies: a new definition, some properties and several conjectures,” preprint http://arxiv.org/abs/arXiv:1306.3142v1 (2013)]. This new quantum divergence has already found applications in quantum information theory. Here we further investigate properties of this new quantum divergence. In particular, we show that sandwiched α-Rényi divergence satisfies the data processing inequality for all values of α > 1. Moreover we prove that α-Holevo information, a variant of Holevo information defined in terms of sandwiched α-Rényi divergence, is super-additive. Our results are based on Hölder's inequality, the Riesz-Thorin theorem and ideas from the theory of complex interpolation. We also employ Sion's minimax theorem.

  9. Static and Fatigue Characterization of Nomex Honeycomb Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Keskes Boualem

    2013-07-01

    Full Text Available The main benefits of using the sandwich concept in structural components are the high stiffness, good fatigue resistance and low weight ratios. Recent advances in materials and construction techniques have resulted in further improvement and increased uniformity of the sandwich composite properties. In order to use these materials in different applications, the knowledge of simply their static properties alone is not sufficient but additional information on their fatigue properties and durability are required. In this paper, first static and fatigue tests on four points bending of nomex honeycomb composite sandwich panels have been performed. Load/displacement and S-N fatigue curves are presented and analysed. Fatigue failure and damage modes are observed with an optical microscope and are discussed. The second is to address such fatigue behaviour by using a damage model and check it by experimentation. This fatigue damage model is based on stiffness degradation, which is used as a damage indicator. Two non-linear cumulative damage models derived from the chosen stiffness degradation equation are examined with assumption of linear Miner's damage summation. Predicted results are compared with available experimental data.

  10. Structural modeling of sandwich structures with lightweight cellular cores

    Science.gov (United States)

    Liu, T.; Deng, Z. C.; Lu, T. J.

    2007-10-01

    An effective single layered finite element (FE) computational model is proposed to predict the structural behavior of lightweight sandwich panels having two dimensional (2D) prismatic or three dimensional (3D) truss cores. Three different types of cellular core topology are considered: pyramidal truss core (3D), Kagome truss core (3D) and corrugated core (2D), representing three kinds of material anisotropy: orthotropic, monoclinic and general anisotropic. A homogenization technique is developed to obtain the homogenized macroscopic stiffness properties of the cellular core. In comparison with the results obtained by using detailed FE model, the single layered computational model can give acceptable predictions for both the static and dynamic behaviors of orthotropic truss core sandwich panels. However, for non-orthotropic 3D truss cores, the predictions are not so well. For both static and dynamic behaviors of a 2D corrugated core sandwich panel, the predictions derived by the single layered computational model is generally acceptable when the size of the unit cell varies within a certain range, with the predictions for moderately strong or strong corrugated cores more accurate than those for weak cores.

  11. Size Effects in Impact Damage of Composite Sandwich Panels

    Science.gov (United States)

    Dobyns, Alan; Jackson, Wade

    2003-01-01

    Panel size has a large effect on the impact response and resultant damage level of honeycomb sandwich panels. It has been observed during impact testing that panels of the same design but different panel sizes will show large differences in damage when impacted with the same impact energy. To study this effect, a test program was conducted with instrumented impact testing of three different sizes of sandwich panels to obtain data on panel response and residual damage. In concert with the test program. a closed form analysis method was developed that incorporates the effects of damage on the impact response. This analysis method will predict both the impact response and the residual damage of a simply-supported sandwich panel impacted at any position on the panel. The damage is incorporated by the use of an experimental load-indentation curve obtained for the face-sheet/honeycomb and indentor combination under study. This curve inherently includes the damage response and can be obtained quasi-statically from a rigidly-backed specimen or a specimen with any support conditions. Good correlation has been obtained between the test data and the analysis results for the maximum force and residual indentation. The predictions can be improved by using a dynamic indentation curve. Analyses have also been done using the MSC/DYTRAN finite element code.

  12. Microtomography with a sandwich detector for mouse bone imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Kim, Junwoo; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of); Youn, Hanbean; Jeon, Hosang [Pusan National University Yangsan Hospital, Yangsan (Korea, Republic of)

    2015-10-15

    Single-shot dual-energy imaging, using sandwich detector, the rear detector usually uses a thicker x-ray converter to enhance quantum efficiency with the higher-energy spectrum, hence providing a blurrier image than the front detector. The weighted logarithmic subtraction of the two images therefore results in a form of unsharp masking that enhances edges in the resultant image. Inspired by this observation, we have developed a micro computed tomography (micro-CT) system with the sandwich detector for high-resolution bone imaging of small animals. The sandwich detector consists of two flat-panel detectors by stacking one upon the other. Although the x-ray beam continuously irradiates, the step-rotation of an object and stay-readout of projection data were considered for the scanning and data gathering. It will be necessary that more elaborate experiments with the mouse and/or other quantitative phantoms. And quantification of the image quality of bone-enhanced images in comparisons with the conventional images will be performed. The image analysis of differences between bone-enhanced images obtained from the projection- and image-based approaches can be performed.

  13. Static and Fatigue Characterization of Nomex Honeycomb Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Keskes Boualem

    2013-07-01

    Full Text Available The main benefits of using the sandwich concept in structural components are the high stiffness, good fatigue resistance and low weight ratios. Recent advances in materials and construction techniques have resulted in further improvement and increased uniformity of the sandwich composite properties. In order to use these materials in different applications, the knowledge of simply their static properties alone is not sufficient but additional information on their fatigue properties and durability are required. In this paper, first static and fatigue tests on four points bending of nomex honeycomb composite sandwich panels have been performed. Load/displacement and S-N fatigue curves are presented and analysed. Fatigue failure and damage modes are observed with an optical microscope and are discussed. The second is to address such fatigue behaviour by using a damage model and check it by experimentation. This fatigue damage model is based on stiffness degradation, which is used as a damage indicator. Two non-linear cumulative damage models derived from the chosen stiffness degradation equation are examined with assumption of linear Miner's damage summation. Predicted results are compared with available experimental data.

  14. Systematic selection of modified aptamer pairs for diagnostic sandwich assays.

    Science.gov (United States)

    Ochsner, Urs A; Green, Louis S; Gold, Larry; Janjic, Nebojsa

    2014-01-01

    Protein diagnostic applications typically require pairs of analyte-specific reagents for capture and detection. We developed methods for the systematic isolation of slow off-rate modified aptamer (SOMAmer) reagents that bind to different epitopes and allow efficient pair-wise screening of multiple ligands. SOMAmers were generated via a second systematic evolution of ligands by exponential enrichment (SELEX), using complexes of target proteins with a primary, non-amplifiable SOMAmer and employing different modified nucleotides (e.g., naphthylmethyl- or tryptaminocarbonyl-dU) to favor alternate binding epitopes. Non-competing binding of primary and secondary SOMAmers was tested in radiolabel competition and sandwich binding assays. Multiplexed high-throughput screening for sandwich pairs utilized the Luminex platform, with primary SOMAmers as capture agents attached to different types of LumAvidin beads, which were then pooled for testing the secondary SOMAmers individually as detection agents. Functional SOMAmer pairs were obtained for Clostridium difficile binary toxin (CdtA) and for a panel of human proteins (ANGPT2, TSP2, CRDL1, MATN2, GPVI, C7, PLG) that had been previously identified as promising markers for cardiovascular risk. The equilibrium dissociation constants (Kd values) ranged from 0.02-2.7 nM, and the detection limits were in the low picomolar range for these proteins in SOMAmer sandwich assays. These results indicate that SOMAmer pairs hold promise for the development of rapid tests or specific diagnostic panels.

  15. Structural modeling of sandwich structures with lightweight cellular cores

    Institute of Scientific and Technical Information of China (English)

    T. Liu; Z. C. Deng; T. J. Lu

    2007-01-01

    An effective single layered finite element (FE) computational model is proposed to predict the structural behavior of lightweight sandwich panels having two dimensional (2D) prismatic or three dimensional (3D) truss cores.Three different types of cellular core topology are considered: pyramidal truss core (3D), Kagome truss core (3D) and corrugated core (2D), representing three kinds of material anisotropy: orthotropic, monoclinic and general anisotropic. A homogenization technique is developed to obtain the homogenized macroscopic stiffness properties of the cellular core. In comparison with the results obtained by using detailed FE model, the single layered computational model cangive acceptable predictions for both the static and dynamic behaviors of orthotropic truss core sandwich panels. However, for non-orthotropic 3D truss cores, the predictions are not so well. For both static and dynamic behaviors of a 2D corrugated core sandwich panel, the predictions derived by the single layered computational model is generally acceptable when the size of the unit cell varies within a certain range, with the predictions for moderately strong or strong corrugated cores more accurate than those for weak cores.

  16. Influence of epidermal growth factor receptor monoclony antibody MAb225 on DNA repair of tongue carcinoma cell after radiation%表皮生长因子受体单抗MAb225对舌癌细胞DNA放射后损伤修复的影响

    Institute of Scientific and Technical Information of China (English)

    王明国; 王中和

    2011-01-01

    Objective The objective of this study is to investigate the effect of epidermal growth factor receptor (EGFR) monoclonal antibody MAb225 on repair of DNA double strand break (DNA-DSB) after radiation in tongue squamous cell carcinoma cell. Methods The single cell gel electrophoresis(SCGE) was performed to estimate the repair of DNA-DSB induced by radiation in human tongue carcinoma cells Tca8113 treated with or without MAb225. Expression of Ku70 and Ku80 were detected by semiquantitative reverse transcription polymerase chain reaction and Western bolt Results Comet tail moment of MAb225 treated cell was significantly higher than untreated cell(P<0.05). The expression of Ku70 and Ku80 were inhibited by MAb225. Conclusion MAb225 can inhibit repair of DNA-DSB induced by down-regulated expression of Ku70 and Ku80.%目的 研究表皮生长因子受体(EGFR)单克隆抗体MAb225对放射所致舌癌细胞DNA损伤修复的影响及其作用机制.方法 应用单细胞凝胶电泳的方法检测MAb225对舌鳞癌细胞Tca8113放射后DNA双链断裂所致的尾矩,半定量逆转录多聚酶链反应和Western blot检测MAb225对DNA蛋白激酶Ku70、Ku80表达的影响.结果 MAb225作用后的细胞单细胞凝胶电泳的彗星尾矩明显高于未处理细胞(P<0.05),并能显著抑制DNA蛋白激酶Ku70、Ku80的表达.结论 MAb225通过抑制DNA蛋白激酶Ku70、Ku80的表达影响了DNA双链断裂的修复能力.

  17. An h-p Finite Element Vibration Analysis of Open Conical Sandwich Panels and Conical Sandwich Frusta

    Science.gov (United States)

    BARDELL, N. S.; LANGLEY, R. S.; DUNSDON, J. M.; AGLIETTI, G. S.

    1999-09-01

    The vibration study of a general three-layer conical sandwich panel based on theh -p version of the finite element method is presented in this paper. No restriction is placed on the degree of curvature of the shell, thereby relaxing the strictures associated with shallow shell theory. The methodology incorporates a new set of trigonometric functions to provide the element p -enrichment, and elements may be joined together to model either open conical panels, or complete conical frusta (circumferentially connected, but open at each end). The full range of classical boundary conditions, which includes free, clamped, simply supported and shear diaphragm edges, may be applied in any combination to open and closed panels, thereby facilitating the study of a wide range of conical sandwich shells. The convergence properties of this element have been established for different combinations of the h - and p -parameters, thereby assuring its integrity for more general use. Since very little work has been reported on the vibration characteristic of either circumferentially closed or open conical sandwich panels, the main thrust of this work has been to present and validate an efficient modelling technique, rather than to perform numerous parameter and/or sensitivity studies. To this end, some new results are presented and subsequently validated using a commercially available finite element package. It is shown that for results of comparable accuracy, models constructed using the h-p formulation require significantly fewer degrees of freedom than those assembled using the commercial package. Some preliminary experimental results are also included for completeness.

  18. Multiple-turnover cleavage of double-stranded DNA by sandwiched zinc-finger nuclease.

    Science.gov (United States)

    Mineta, Yusuke; Okamoto, Tomoyuki; Takenaka, Kosuke; Doi, Norio; Aoyama, Yasuhiro; Sera, Takashi

    2009-01-01

    To refine zinc-finger nuclease (ZFN) technology, we constructed a sandwiched ZFN, in which a DNA cleavage enzyme was sandwiched with two artificial zinc-finger proteins (AZPs). Because the sandwiched ZFN is designed to cleave the DNA between the two AZP-binding sites, the sandwiched ZFN is expected to bind preferentially to a DNA substrate rather than to cleavage products and thereby cleave it with multiple turnovers. To prove the concept, we sandwiched a staphylococcal nuclease (SNase), which cleaves DNA as a monomer, between two 3-finger AZPs. The AZP-sandwiched SNase cleaved large amounts of dsDNA site-specifically. Such multiple-turnover cleavage was not observed with control nucleases that possess a single AZP.

  19. Fatigue fracture of fiber reinforced polymer honeycomb composite sandwich structures for gas turbine engines

    Science.gov (United States)

    Nikhamkin, Mikhail; Sazhenkov, Nikolai; Samodurov, Danil

    2017-05-01

    Fiber reinforced polymer honeycomb composite sandwich structures are commonly used in different industries. In particular, they are used in the manufacture of gas turbine engines. However, fiber reinforced polymer honeycomb composite sandwich structures often have a manufacturing flaw. In theory, such flaws due to their rapid propagation reduce the durability of fiber reinforced polymer honeycomb composite sandwich structures. In this paper, bending fatigue tests of fiber reinforced polymer honeycomb composite sandwich structures with manufacturing flaws were conducted. Comparative analysis of fatigue fracture of fiber reinforced polymer honeycomb composite sandwich specimens was conducted before and after their bending fatigue tests. The analysis was based on the internal damage X-ray observation of fiber reinforced polymer honeycomb composite sandwich specimens.

  20. Public availability of a genotyped, segregating population may foster marker assisted breeding (MAB) and quantitative trait loci (QTL) discovery: An example using strawberry

    Science.gov (United States)

    Much of the cost associated with marker discovery for marker assisted breeding (MAB) can be eliminated if a diverse, segregating population is generated, genotyped and made available to the global breeding community. Herein, we present an example of a hybrid, wild-derived family of the octoploid str...

  1. Experimental investigation on vibration characteristics of sandwich beams with magnetorheological elastomers cores

    Institute of Scientific and Technical Information of China (English)

    魏克湘; 孟光; 张文明; 朱石沙

    2008-01-01

    A sandwich beam specimen was fabricated by treating with MR elastomers between two thin aluminum face-plates.Experiment was carried out to investigate the vibration responses of the sandwich beam with respect to the intensity of the magnetic field and excitation frequencies.The results show that the sandwich beams with MR elastomers cores have the capabilities of shifting natural frequencies and the vibration amplitudes decrease with the variation of the intensity of external magnetic field.

  2. Effects of Subzero Temperatures and Sea Water Immersion on Damage Initiation and Growth in Sandwich Composites

    Science.gov (United States)

    2008-12-10

    single cantilever beam sandwich test. The TSD is perhaps 19 An improved methodology for measuring the interracial toughness of sandwich beams 3...measuring the interracial toughness of sandwich beams 5 Table 4.1. Material properties Glass face Glass face Carbon „ , ,, Loading L...which shows the relationship between reaction forces for an MSCB specimen with 12 ply glass face sheets at different crack lengths. It is observed

  3. Differential expression of Meis2, Mab21l2 and Tbx3 during limb development associated with diversification of limb morphology in mammals.

    Science.gov (United States)

    Dai, Mengyao; Wang, Yao; Fang, Lu; Irwin, David M; Zhu, Tengteng; Zhang, Junpeng; Zhang, Shuyi; Wang, Zhe

    2014-01-01

    Bats are the only mammals capable of self-powered flight using wings. Differing from mouse or human limbs, four elongated digits within a broad wing membrane support the bat wing, and the foot of the bat has evolved a long calcar that spread the interfemoral membrane. Our recent mRNA sequencing (mRNA-Seq) study found unique expression patterns for genes at the 5' end of the Hoxd gene cluster and for Tbx3 that are associated with digit elongation and wing membrane growth in bats. In this study, we focused on two additional genes, Meis2 and Mab21l2, identified from the mRNA-Seq data. Using whole-mount in situ hybridization (WISH) we validated the mRNA-Seq results for differences in the expression patterns of Meis2 and Mab21l2 between bat and mouse limbs, and further characterize the timing and location of the expression of these two genes. These analyses suggest that Meis2 may function in wing membrane growth and Mab21l2 may have a role in AP and DV axial patterning. In addition, we found that Tbx3 is uniquely expressed in the unique calcar structure found in the bat hindlimb, suggesting a role for this gene in calcar growth and elongation. Moreover, analysis of the coding sequences for Meis2, Mab21l2 and Tbx3 showed that Meis2 and Mab21l2 have high sequence identity, consistent with the functions of genes being conserved, but that Tbx3 showed accelerated evolution in bats. However, evidence for positive selection in Tbx3 was not found, which would suggest that the function of this gene has not been changed. Together, our findings support the hypothesis that the modulation of the spatiotemporal expression patterns of multiple functional conserved genes control limb morphology and drive morphological change in the diversification of mammalian limbs.

  4. Differential expression of Meis2, Mab21l2 and Tbx3 during limb development associated with diversification of limb morphology in mammals.

    Directory of Open Access Journals (Sweden)

    Mengyao Dai

    Full Text Available Bats are the only mammals capable of self-powered flight using wings. Differing from mouse or human limbs, four elongated digits within a broad wing membrane support the bat wing, and the foot of the bat has evolved a long calcar that spread the interfemoral membrane. Our recent mRNA sequencing (mRNA-Seq study found unique expression patterns for genes at the 5' end of the Hoxd gene cluster and for Tbx3 that are associated with digit elongation and wing membrane growth in bats. In this study, we focused on two additional genes, Meis2 and Mab21l2, identified from the mRNA-Seq data. Using whole-mount in situ hybridization (WISH we validated the mRNA-Seq results for differences in the expression patterns of Meis2 and Mab21l2 between bat and mouse limbs, and further characterize the timing and location of the expression of these two genes. These analyses suggest that Meis2 may function in wing membrane growth and Mab21l2 may have a role in AP and DV axial patterning. In addition, we found that Tbx3 is uniquely expressed in the unique calcar structure found in the bat hindlimb, suggesting a role for this gene in calcar growth and elongation. Moreover, analysis of the coding sequences for Meis2, Mab21l2 and Tbx3 showed that Meis2 and Mab21l2 have high sequence identity, consistent with the functions of genes being conserved, but that Tbx3 showed accelerated evolution in bats. However, evidence for positive selection in Tbx3 was not found, which would suggest that the function of this gene has not been changed. Together, our findings support the hypothesis that the modulation of the spatiotemporal expression patterns of multiple functional conserved genes control limb morphology and drive morphological change in the diversification of mammalian limbs.

  5. Anti-CD154 mAb and rapamycin induce T regulatory cell mediated tolerance in rat-to-mouse islet transplantation.

    Directory of Open Access Journals (Sweden)

    Yannick D Muller

    Full Text Available BACKGROUND: Anti-CD154 (MR1 monoclonal antibody (mAb and rapamycin (RAPA treatment both improve survival of rat-to-mouse islet xenograft. The present study investigated the effect of combined RAPA/MR1 treatment on rat-to-mouse islet xenograft survival and analyzed the role of CD4(+CD25(+Foxp3(+ T regulatory cells (Treg in the induction and maintenance of the ensuing tolerance. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6 mice were treated with MR1/RAPA and received additional monoclonal anti-IL2 mAb or anti CD25 mAb either early (0-28 d or late (100-128 d post-transplantation. Treg were characterised in the blood, spleen, draining lymph nodes and within the graft of tolerant and rejecting mice by flow cytometry and immunohistochemistry. Fourteen days of RAPA/MR1 combination therapy allowed indefinite islet graft survival in >80% of the mice. Additional administration of anti-IL-2 mAb or depleting anti-CD25 mAb at the time of transplantation resulted in rejection (100% and 89% respectively, whereas administration at 100 days post transplantation lead to lower rejection rates (25% and 40% respectively. Tolerant mice showed an increase of Treg within the graft and in draining lymph nodes early post transplantation, whereas 100 days post transplantation no significant increase of Treg was observed. Rejecting mice showed a transient increase of Treg in the xenograft and secondary lymphoid organs, which disappeared within 7 days after rejection. CONCLUSIONS/SIGNIFICANCES: These results suggest a critical role for Treg in the induction phase of tolerance early after islet xenotransplantation. These encouraging data support the need of developing further Treg therapy for overcoming the species barrier in xenotransplantation.

  6. Fabrication and Testing of Carbon Fiber Reinforced Truss Core Sandwich Panels

    Institute of Scientific and Technical Information of China (English)

    Bing Wang; Linzhi Wu; Li Ma; Qiang Wang; Shanyi Du

    2009-01-01

    Truss core sandwich panels reinforced by carbon fibers were assembled with bonded laminate facesheets and carbon fiber reinforced truss cores. The top and bottom facesheets were interconnected with truss cores. Both ends of the truss cores were embedded into four layers of top and bottom facesheets. The mechanical properties of truss core sandwich panels were then investigated under out-of-plane and in-plane compression loadings to reveal the failure mechanisms of sandwich panels. Experimental results indicated that the mechanical behavior of sandwich structure under in-plane loading is dominated by the buckling and debonding of facesheets.

  7. Fiber-Reinforced-Foam (FRF) Core Composite Sandwich Panel Concept for Advanced Composites Technologi

    Science.gov (United States)

    2010-01-01

    Fiber-Reinforced-Foam (FRF) Core Composite Sandwich Panel Concept for Advanced Composites Technologies Project - Preliminary Manufacturing Demonstration Articles for Ares V Payload Shroud Barrel Acreage Structure

  8. Giant magnetoresistance effect in Ni buffered Co/Cu/Co sandwich

    Institute of Scientific and Technical Information of China (English)

    LI; Tie(李铁)

    2002-01-01

    The effects of Ni buffer layer on the giant magnetoresistance structure of Co/Cu/Co sandwich are investigated systematically in this paper.It is found that Ni buffer layer can induce the crystallization of the lower Ni/Co layer and produce small coercivity,thus enlarging the difference in the magnetic behavior between the two magnetic layers in the sandwich.Moreover,the use of the Ni buffer layer can also improve the interface flatness in the sandwich.All these factors enhance the sensitivity of the Ni buffered sandwich.``

  9. Combined-load buckling behavior of metal-matrix composite sandwich panels under different thermal environments

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1991-01-01

    Combined compressive and shear buckling analysis was conducted on flat rectangular sandwich panels with the consideration of transverse shear effects of the core. The sandwich panel is fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that the square panel has the highest combined load buckling strength, and that the buckling strength decreases sharply with the increases of both temperature and panel aspect ratio. The effect of layup (fiber orientation) on the buckling strength of the panels was studied in detail. The metal matrix composite sandwich panel was much more efficient than the sandwich panel with nonreinforced face sheets and had the same specific weight.

  10. Mechanical evaluation with fe analysis of sandwich panels for wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Yasaswi, M.; Naveen, P.N.E.; Prasad, R.V. [GIET. Dept. of Mechanical Engineering, Rajahmundry (India)

    2012-07-01

    Sandwich panels are notable for their structural efficiency and are used as load bearing components in various branches of engineering, especially in aerospace and marine industries. The objective of the present work is to perform computer-aided analysis on sandwich panels. The analysis of sandwich panel with truss core are compared with other four types of sandwich panel with continuous corrugated core, top hat core, zed core and channel core. The basic reason to use sandwich structure is to save weight, however smooth skins and excellent fatigue resistance are also attributes of a sandwich structure. A sandwich is comprised of two layered composite materials formed by bonding two or more thin facings or face sheets to relatively thick core materials. In this type of construction the facings resist nearly all of the in-plane loads and out-of-plane bending moments. The thin facings provide nearly all of the bending stiffness because they are generally of a much higher modulus material is located at a greatest distance from the neutral axis of the component. The basic concept of sandwich panel is that the facings carry the bending loads and the core carries the shear loads. The main function of the core material is to distribute local loads and stresses over large areas. From all this analysis it is concluded that the truss core Sandwich panels can be used in wind turbine blade design. (Author)

  11. Current rectification in nickelocenylferrocene sandwiched between two gold electrodes.

    Science.gov (United States)

    Matsuura, Yukihito

    2013-01-07

    I present a theoretical study of the electronic transport properties of nickelocenylferrocene sandwiched between gold electrodes. Compared with the biferrocene system, the nickelocenylferrocene system had high electrical conduction and rectification in the bias range -1 to 1 V. Furthermore, the spin-down states of the nickelocenylferrocene system exhibited perfect spin-filtering properties. From the electronic states of the nickelocenylferrocene, it was found that the rectification was caused by a difference in the bias-dependent behaviors between the Fe 3d and Ni 3d orbitals.

  12. A Conformal Thin-Sandwich Solver for Generic Initial Data

    CERN Document Server

    East, William E; Pretorius, Frans

    2012-01-01

    We present a new scheme for constructing initial data for the Einstein field equations using the conformal thin-sandwich formulation that does not assume conformal flatness or approximate Killing vectors. This includes a method for determining free data based on superposition, as well as a way to handle black hole singularities without excision. We numerically solve the constraint equations using a multigrid algorithm with mesh refinement. We demonstrate the efficacy of the method with initial data solutions for several applications: a quasi-circular binary black hole merger, a dynamical capture black hole-neutron star merger, and an ultrarelativistic collision.

  13. Standard Test Method for Dimensional Stability of Sandwich Core Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This test method covers the determination of the sandwich core dimensional stability in the two plan dimensions. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Standard Test Method for Shear Fatigue of Sandwich Core Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers determination of the effect of repeated shear loads on sandwich core materials. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  15. Hydrogen storage property of sandwiched magnesium hydride nanoparticle thin film

    Energy Technology Data Exchange (ETDEWEB)

    Barcelo, Steven; Rogers, Matthew; Grigoropoulos, Costas P.; Mao, Samuel S. [Lawrence Berkeley National Laboratory and Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720 (United States)

    2010-07-15

    Hydrogen sorption property of magnesium (Mg) in the form of sandwiched Pd/Mg/Pd films is investigated. Pulsed laser deposition method was applied to deposit the samples consisting of films of nanoparticles. The enthalpy of formation of MgH{sub 2} was found to be -68 kJ/mol H{sub 2} for films with nanoparticle size on the order of 50 nm, which is smaller than the value for bulk MgH{sub 2} and may be explained by the concept of excess volume. (author)

  16. Optimization of the curing process of a sandwich panel

    Science.gov (United States)

    Phyo Maung, Pyi; Tatarnikov, O.; Malysheva, G.

    2016-10-01

    This study presented finite element modelling and experimental measurements of temperatures during the autoclave curing of the T-50 aircraft wing sandwich panel. This panel consists of upper and lower carbon fibre based laminates and an aluminium foil honeycomb. The finite element modelling was performed using the Femap-Nastran product. During processing, the temperature at various points on the surface of the panel was measured using the thermocouples. The finite element method simulated the thermal conditions and determined the temperatures in the different parts of the panel for a full cycle of the curing process. A comparison of the calculated and experimental data shows that their difference does not exceed 6%.

  17. Devices, systems, and methods for conducting sandwich assays using sedimentation

    Energy Technology Data Exchange (ETDEWEB)

    Schaff, Ulrich Y; Sommer, Gregory J; Singh, Anup K; Hatch, Anson V

    2015-02-03

    Embodiments of the present invention are directed toward devices, systems, and method for conducting sandwich assays using sedimentation. In one example, a method includes generating complexes on a plurality of beads in a fluid sample, individual ones of the complexes comprising a capture agent, a target analyte, and a labeling agent. The plurality of beads including the complexes may be transported through a density media, wherein the density media has a density lower than a density of the beads and higher than a density of the fluid sample, and wherein the transporting occurs, at least in part, by sedimentation. Signal may be detected from the labeling agents of the complexes.

  18. Experimental Investigations of Compressed Sandwich Composite/Honeycomb Cylindrical Shells

    Science.gov (United States)

    Muc, A.; Stawiarski, A.; Romanowicz, P.

    2017-06-01

    This article explains in some details the behaviour of thick, deep cylindrical sandwich panels subjected to compressive loads. In general, experimental results indicated that two different forms of failure have been observed - the first corresponds to the overall buckling and the second to the facesheet wrinkling. The obtained experimentally damages of shells are verified and validated with the use of the FE analysis, 2-D and 3-D both in the linear and non-linear approach. The unidirectional strain gauges were applied to detect the initiation of the overall buckling mode.

  19. FINITE ELEMENT MODELING OF THIN CIRCULAR SANDWICH PLATES DEFLECTION

    Directory of Open Access Journals (Sweden)

    K. S. Kurachka

    2014-01-01

    Full Text Available A mathematical model of a thin circular sandwich plate being under the vertical load is proposed. The model employs the finite element method and takes advantage of an axisymmetric finite element that leads to the small dimension of the resulting stiffness matrix and sufficient accuracy for practical calculations. The analytical expressions for computing local stiffness matrices are found, which can significantly speed up the process of forming the global stiffness matrix and increase the accuracy of calculations. A software is under development and verification. The discrepancy between the results of the mathematical model and those of analytical formulas for homogeneous thin circularsandwich plates does not exceed 7%.

  20. Sandwich Hologram Interferometry For Determination Of Sacroiliac Joint Movements

    Science.gov (United States)

    Vukicevic, S.; Vinter, I.; Vukicevic, D.

    1983-12-01

    Investigations were carried out on embalmed and fresh specimens of human pelvisis with preserved lumbar spines, hip joints and all the ligaments. Specimens were tested under static vertical loading by pulsed laser interferometry. The deformations and behaviour of particular pelvic parts were interpreted by providing computer interferogram models. Results indicate rotation and tilting of the sacrum in the dorso-ventral direction and small but significant movements in the cranio-caudal direction. Sandwich holography proved to be the only applicable method when there is a combination of translation and tilt in the range of 200 μm to 1.5 mm.

  1. Optical and thermophysical parameters measurement using sandwich photodetectors

    Science.gov (United States)

    Turinov, Valery I.

    1993-12-01

    A method is reported for estimating thermophysical and optical parameters, in which a two- spectral band sandwich photodetector is used. The sensitivity ranges of such a sensor are 2 - 5 micrometers and 8 - 14 micrometers . On irradiating an object's surface by a short radiation pulse the photodetector collected signals U1, U2 and the rates of their changes (dU1/dt), (dU2/dt) are recorded. These pertain to the same area on the object's surface and belong to the two spectral ranges mentioned. The parameters of the object are evaluated by means of calculations with the values measured.

  2. Structural Analysis of Human and Macaque mAbs 2909 and 2.5B: Implications for the Configuration of the Quaternary Neutralizing Epitope of HIV-1 gp120

    Energy Technology Data Exchange (ETDEWEB)

    Spurrier, Brett; Sampson, Jared M.; Totrov, Maxim; Li, Huiguang; O; Neal, Timothy; Williams, Constance; Robinson, James; Gorny, Miroslaw K.; Zolla-Pazner, Susan; Kong, Xiang-Peng (Molsoft); (Tulane); (NYUSM)

    2011-08-25

    The quaternary neutralizing epitope (QNE) of HIV-1 gp120 is preferentially expressed on the trimeric envelope spikes of intact HIV virions, and QNE-specific monoclonal antibodies (mAbs) potently neutralize HIV-1. Here, we present the crystal structures of the Fabs of human mAb 2909 and macaque mAb 2.5B. Both mAbs have long beta hairpin CDR H3 regions >20 {angstrom} in length that are each situated at the center of their respective antigen-binding sites. Computational analysis showed that the paratopes include the whole CDR H3, while additional CDR residues form shallow binding pockets. Structural modeling suggests a way to understand the configuration of QNEs and the antigen-antibody interaction for QNE mAbs. Our data will be useful in designing immunogens that may elicit potent neutralizing QNE Abs.

  3. Development of a monoclonal antibody against the left wing of ciguatoxin CTX1B: thiol strategy and detection using a sandwich ELISA.

    Science.gov (United States)

    Tsumuraya, Takeshi; Takeuchi, Katsutoshi; Yamashita, Shuji; Fujii, Ikuo; Hirama, Masahiro

    2012-09-01

    Ciguatera fish poisoning (CFP) is a form of food poisoning caused by the ingestion of a variety of reef fish that have accumulated trace amounts of ciguatoxins produced by dinoflagellates of the genus Gambierdiscus through the food chain. CFP affects more than 50,000 people each year. The extremely low level of the causative neurotoxins, ciguatoxins, in fish has hampered the preparation of antibodies for detecting the toxins. In this paper, we describe a thiol strategy for synthesizing a keyhole limpet hemocyanin (KLH)-conjugate (20) of the ABCDE-ring fragment of the Pacific ciguatoxins, CTX1B (1) and 54-deoxyCTX1B (4). We succeeded in producing a monoclonal antibody (3G8) against the left wings of these ciguatoxins by immunizing mice with the hapten-KLH conjugate (20) as the synthetic antigen. The most promising mAb, 3G8, does not cross-react with other related marine toxins. Sandwich enzyme-linked immunosorbent assay (ELISA) utilizing 3G8 and the previously prepared monoclonal antibody (8H4) enabled us to detect 1 specifically at less than 0.28 ng/mL.

  4. Pistachio (Pistacia vera L.) Detection and Quantification Using a Murine Monoclonal Antibody-Based Direct Sandwich Enzyme-Linked Immunosorbent Assay.

    Science.gov (United States)

    Liu, Changqi; Chhabra, Guneet S; Sathe, Shridhar K

    2015-10-21

    A commercially available direct sandwich enzyme-linked immunosorbent assay (ELISA) (BioFront Technologies, Tallahassee, FL, USA) using murine anti-pistachio monoclonal antibodies (mAbs) as capture and detection antibodies was evaluated. The assay was sensitive (limit of detection = 0.09 ± 0.02 ppm full fat pistachio, linear detection range = 0.5-36 ppm, 50% maximum signal concentration = 7.9 ± 0.7 ppm), reproducible (intra- and inter-assay variability pistachio seeds subjected to autoclaving (121 °C, 15 psi, 15, 30 min), blanching (100 °C, 5, 10 min), frying (191 °C, 1 min), microwaving (500, 1000 W, 3 min), and dry roasting (140 °C, 30 min; 168 °C, 12 min). No cross-reactivity was observed in 156 food matrices, each tested at 100,000 ppm, suggesting the ELISA to be pistachio specific. The pistachio recovery ranges for spiked (10 ppm) and incurred (10-50000 ppm) food matrices were 93.1-125.6% and 35.7-112.2%, respectively. The assay did not register any false-positive or -negative results among the tested commercial and laboratory prepared samples.

  5. Comparison of Laboratory-Developed and Commercial Monoclonal Antibody-Based Sandwich Enzyme-Linked Immunosorbent Assays for Almond (Prunus dulcis) Detection and Quantification.

    Science.gov (United States)

    Liu, Changqi; Chhabra, Guneet S; Zhao, Jing; Zaffran, Valerie D; Gupta, Sahil; Roux, Kenneth H; Gradziel, Thomas M; Sathe, Shridhar K

    2017-09-04

    A commercially available monoclonal antibody (mAb)-based direct sandwich enzyme-linked immunosorbent assay (ELISA) kit (BioFront Technologies, Tallahassee, Fla., U.S.A.) was compared with an in-house developed mAb 4C10-based ELISA for almond detection. The assays were comparable in sensitivity (limit of detection < 1 ppm full fat almond, limit of quantification < 5 ppm full fat almond), specificity (no cross-reactivity with 156 tested foods at a concentration of 100000 ppm whole sample), and reproducibility (intra- and interassay variability < 15% CV). The target antigens were stable and detectable in whole almond seeds subjected to autoclaving, blanching, frying, microwaving, and dry roasting. The almond recovery ranges for spiked food matrices were 84.3% to 124.6% for 4C10 ELISA and 81.2% to 127.4% for MonoTrace ELISA. The almond recovery ranges for commercial and laboratory prepared foods with declared/known almond amount were 30.9% to 161.2% for 4C10 ELISA and 38.1% to 207.6% for MonoTrace ELISA. Neither assay registered any false-positive or negative results among the tested commercial and laboratory prepared samples. © 2017 Institute of Food Technologists®.

  6. Active structural health monitoring of composite plates and sandwiches

    Directory of Open Access Journals (Sweden)

    Sadílek P.

    2013-12-01

    Full Text Available The aim of presented work is to design, assemble and test a functional system, that is able to reveal damage from impact loading. This is done by monitoring of change of spectral characteristics on a damaged structure that is caused by change of mechanical properties of material or by change of structure’s geometry. Excitation and monitoring of structures was done using piezoelectric patches. Unidirectional composite plate was tested for eigenfrequencies using chirp signal. The eigenfrequencies were compared to results from experiments with an impact hammer and consequently with results from finite element method. Same method of finding eigenfrequencies was used on a different unidirectional composite specimen. Series of impacts were performed. Spectrum of eigenfrequencies was measured on undamaged plate and then after each impact. Measurements of the plate with different level of damage were compared. Following experiments were performed on sandwich materials where more different failures may happen. Set of sandwich beams (cut out from one plate made of two outer composite layers and a foam core was investigated and subjected to several impacts. Several samples were impacted in the same manner to get comparable results. The impacts were performed with growing impact energy.

  7. A Z_m Ham Sandwich Theorem for Complex Measures

    CERN Document Server

    Simon, Steven

    2010-01-01

    A "ham sandwich" theorem is derived for n complex measures on C^n. For each integer m >= 2, a complex hyperplane H and m corresponding "1/m" sectors are found, satisfying the condition that the "rotational average" of the measures of these sectors is zero. The result can be seen as a kind of rotational equipartition of each measure by a regular "m-fan". The proof of the theorem is topological, based on a Z_m version of the Borsuk-Ulam theorem for punctured (2n - 1)-spheres in C^n. Any finite real measure on R^{2n} can be seen as a type of complex measure on C^n, so the theorem can be applied to n finite measures on R^{2n}. In the case that m = 3, this shows the existence of a regular 3-fan which trisects each of the n measures. Similarly, any pair of finite real measures on R^{2n} can be naturally identified with a complex measure on C^n, so the theorem applies to 2n finite measures on R^{2n}. This yields a rotational condition on pairs of finite measures, and the original ham sandwich theorem for R^{2n} is r...

  8. Plasmonic nanomesh sandwiches for ultrathin film silicon solar cells

    Science.gov (United States)

    Gao, Tongchuan; Wang, Baomin; Leu, Paul W.

    2017-02-01

    We theoretically investigate the strategy of integrating metal nanoparticles (NPs)/nanomeshes (NMs) into the top and/or bottom of crystalline silicon (c-Si) thin film solar cells for light trapping and enhanced carrier collection. C-Si thin films exhibit absorption resonances corresponding to Fabry-Pérot modes. Frontside metal NPs enhance absorption by additionally coupling light into localized surface plasmon resonances and c-Si waveguide modes, while a frontside metal NM increases absorption by coupling light into surface plasmon polaritons and c-Si waveguide modes. The frontside metal NM also functions as a flexible top electrode, which may replace conventional brittle transparent conductive oxide thin films. The backside metal NM exhibits enhanced absorption due to the coupling of light into c-Si waveguide modes and the cavity modes within the holes of metal NM. We illustrate how the optimal metal NM sandwich, consisting of NMs on both sides of a 300 nm thick c-Si with an appropriate antireflection coating (ARC), achieves a 72.9% enhancement in short-circuit current density compared with that of a 300 nm thick c-Si thin film solar cell with 100 nm thick Si3N4 ARC and 300 nm thick Ag back reflector. The current generation in the metal NM sandwich is more in the center of the thin film such that there should be less surface recombination. The uniform current generation throughout the film results in less overall recombination.

  9. Dispersion of guided waves in composite laminates and sandwich panels

    Science.gov (United States)

    Schaal, Christoph; Mal, Ajit

    2015-03-01

    In composite structures, damages are often invisible from the surface and can grow to reach a critical size, potentially causing catastrophic failure of the entire structure. Thus safe operation of these structures requires careful monitoring of the initiation and growth of such defects. Ultrasonic methods using guided waves offer a reliable and cost-effective method for structural health monitoring in advanced structures. Guided waves allow for long monitoring ranges and are very sensitive to defects within their propagation path. In this work, the relevant properties of guided Lamb waves for damage detection in composite structures are investigated. An efficient numerical approach is used to determine their dispersion characteristics, and these results are compared to those from laboratory experiments. The experiments are based on a pitch-catch method, in which a pair of movable transducers is placed on one surface of the structure to induce and detect guided Lamb waves. The specific cases considered include an aluminum plate and an aluminum honeycomb sandwich panel with woven composite face sheets. In addition, a disbond of the interface between one of the face sheets and the honeycomb core of the sandwich panel is also considered, and the dispersion characteristics of the two resultant waveguides are determined. Good agreement between numerical and experimental dispersion results is found, and suggestions on the applicability of the pitch-catch system for structural health monitoring are made.

  10. Free Vibration and Hardening Behavior of Truss Core Sandwich Beam

    Directory of Open Access Journals (Sweden)

    J. E. Chen

    2016-01-01

    Full Text Available The dynamic characteristics of simply supported pyramidal truss core sandwich beam are investigated. The nonlinear governing equation of motion for the beam is obtained by using a Zig-Zag theory. The averaged equations of the beam with primary, subharmonic, and superharmonic resonances are derived by using the method of multiple scales and then the corresponding frequency response equations are obtained. The influences of strut radius and core height on the linear natural frequencies and hardening behaviors of the beam are studied. It is illustrated that the first-order natural frequency decreases continuously and the second-order and third-order natural frequencies initially increase and then decrease with the increase of strut radius, and the first three natural frequencies all increase with the rise of the core height. Furthermore, the results indicate that the hardening behaviors of the beam become weaker with the increase of the rise of strut radius and core height. The mechanisms of variations in hardening behavior of the sandwich beam with the three types of resonances are detailed and discussed.

  11. Immunometric Double-Antibody Sandwich Enzyme-Linked Immunosorbent Assay.

    Science.gov (United States)

    Kohl, Thomas O; Ascoli, Carl A

    2017-06-01

    The double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) is preferentially used to determine the concentration of unknown antibody in a sample. Pure antigen is not required in this assay; however, the use of a reporter-labeled detection antibody is essential. The double-antibody sandwich ELISA is suitable for epitope mapping of different monoclonal antibodies that have been generated against a single antigen. First, plates are coated with a capture antibody specific for immunoglobulins generated by immunization of a host species. Next, the test antibody solution (e.g., serum) is incubated with the capture antibody to facilitate binding. The plates are washed to remove unbound antibody, and then antigen is added. The plates are washed again followed by the addition of an antigen-specific reporter-labeled antibody. Following incubation, unbound reporter antibody is washed off, and reporter-specific substrate is added. Reporter-mediated substrate hydrolysis is visualized and measured. The signal is proportional to the number of test antibodies present in the serum. © 2017 Cold Spring Harbor Laboratory Press.

  12. Impact Delamination and Fracture in Aluminum/Acrylic Sandwich Plates

    Science.gov (United States)

    Liaw, Benjamin; Zeichner, Glenn; Liu, Yanxiong; Bowles, Kenneth J. (Technical Monitor)

    2000-01-01

    Impact-induced delamination and fracture in 6061-T6 aluminum/cast acrylic sandwich plates adhered by epoxy were generated in an instrumented drop-weight impact machine. Although only a small dent was produced on the aluminum side when a hemispherical penetrator tup was dropped onto it from a couple of inches, a large ring of delamination at the interface was observed. The delamination damage was often accompanied by severe shattering in the acrylic substratum. Damage patterns in the acrylic layer include radial and ring cracks and, together with delamination at the interface, may cause peeling-off of acrylic material from the sandwich plate. Theory of stress-wave propagation can be used to explain these damage patterns. The impact tests were conducted at various temperatures. The results also show clearly that temperature effect is very important in impact damage. For pure cast acrylic nil-ductile transition (NDT) occurs between 185-195 F. Excessive impact energy was dissipated into fracture energy when tested at temperature below this range or through plastic deformation when tested at temperature above the NDT temperature. Results from this study will be used as baseline data for studying fiber-metal laminates, such as GLARE and ARALL for advanced aeronautical and astronautical applications.

  13. Modelling of Debond and Crack Propagation in Sandwich Structures Using Fracture and Damage Mechanics

    DEFF Research Database (Denmark)

    Berggreen, C.; Simonsen, Bo Cerup; Toernqvist, Rikard

    2003-01-01

    Skin-core de-bonding or core crack propagation will often be dominating mechanisms in the collapse modes of sandwich structures. This paper presents two different methods for prediction of crack propagation in a sandwich structure: a fracture mechanics approach, where a new mode-mix method...

  14. Failure Investigation of Debonded Sandwich Columns: An Experimental and Numerical Study

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Berggreen, Christian; Carlsson, Leif A.

    2009-01-01

    Failure of compression loaded sandwich columns with an implanted through-width face/core debond is examined. Compression tests were conducted on sandwich columns containing implemented face/core debonds. The strains and out-of-plane displacements of the debonded region were monitored using the di...

  15. Research overview of design method of super light multi-hole class- honeycomb sandwich structure materials

    Directory of Open Access Journals (Sweden)

    Xiang LI

    Full Text Available With the sandwich structure materials' application and promotion in the field of engineering continuously, existing sandwich structure material gradually cannot meet the design requirements. It is very urgent to develop new sandwich structure materials of high efficiency, energy saving and easy to process. The project puts forward and constructs a new kind of class-honeycomb sandwich structure material combined with important application backgrounds that super light and high strength metal sandwich structure materials are applied into the high weight and high energy consumption equipments of automobile, aerospace and machinery and so on. This research involve: mechanical properties equivalent method for the class-honeycomb sandwich structure and its core; Strength, stiffness and inherent frequency characteristic and failure criterions of the class-honeycomb sandwich structure; based on the failure criterions constructing the multiple-constraint models of the class-honeycomb sandwich structure. The research tries to put forward a new method for innovative design of lightweight material and structure and new ideas of lightweight technology research in theory and practice.

  16. Real-time X-ray investigation of aluminum foam sandwich production

    Energy Technology Data Exchange (ETDEWEB)

    Banhart, J.; Stanzick, H. [Fraunhofer-Inst. for Advanced Materials, Bremen (Germany); Helfen, L.; Baumbach, T. [Fraunhofer-Inst. for Non-Destructive Testing, Dresden (Germany); Nijhof, K. [Honsel-Werke AG, Meschede (Germany)

    2001-06-01

    The authors study the foaming behavior of Al-based sandwich panels using X-ray radioscopy. X-ray radioscopy is a suitable tool for observing the metal foaming process in general and the production of aluminum foam sandwich panels in particular. The internal structure of the foam can be resolved clearly. (orig.)

  17. A Phloem Sandwich Unit for Observing Bark Beetles, Associated Predators, and Parasites

    Science.gov (United States)

    Donald N. Kim; Mitchel C. Miller

    1981-01-01

    This paper describes a phloem sandwich that allows observation of parent beetles, their brood, and associates within the inner bark, and permits observation of predator and parasite behavior on the bark surface. The construction of the unit permits the introduction of multiple pairs of beetles into a single sandwich.

  18. Sandwich Magnetoelectric Composites of Polyvinylidene Fluoride, Tb-Dy-Fe Alloy, and Lead Zirconate Titanate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The novel sandwich composites were prepared by sandwiching a polyvinylidene fluoride/Tb-Dy-Fe alloy composite (PVDF/Terfenol-D) between polyvinylidene fluoride/lead zirconate titanate composites(PVDF/PZT). The maximum magnetoelectric effect voltage coefficient, (dE/dH)33max, of the sandwich composites is higher than that of three-phase composites at their own optimal loading level of Terfenol-D. This is attributed to less interface relaxations of strain and better polarization of the sandwich composites. When the volume fraction of Terfenol-D is higher than 0.10, no coupling interaction for three-phase composites could intensity, the magnetoelectric effect voltage coefficient, (dE/dH)33, of sandwich composites is higher than that of three-phase composites; at low magnetic field intensity, (dE/dH)33 of sandwich composites is lower than that of three-phase composites. At their resonance frequency, the (dE/dH)33max of the sandwich composites and the dH)33max at resonance frequency confirms the improvement of maximum magnetoelectric effect coefficient via sandwich-structured composites.

  19. PMI Foam Cored Sandwich Components Produced by Means of Different Manufacturing Methods

    Institute of Scientific and Technical Information of China (English)

    Leonhard Maier; HU Pei; Herman Seibert

    2006-01-01

    The paper introduced the structural applications with PMI (Polymethacrylimide) foams in sandwich components for rotor craft, launching vehicle and civil aircraft and discuss some typically used manufacturing methods, such as e. g.in-mould pressing, autoclave curing and resin infusion. The advantages of foam-cored sandwich design versus honeycombcored design will be discussed, focussing on manufacturing costs.

  20. Failure Investigation of Debonded Sandwich Columns: An Experimental and Numerical Study

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Berggreen, Christian; Carlsson, Leif A.

    2009-01-01

    Failure of compression loaded sandwich columns with an implanted through-width face/core debond is examined. Compression tests were conducted on sandwich columns containing implemented face/core debonds. The strains and out-of-plane displacements of the debonded region were monitored using the di...

  1. Mixed mode fracture toughness characterization of sandwich interfaces using the modified TSD specimen

    DEFF Research Database (Denmark)

    Berggreen, Christian; Andreasen, J.H.; Carlsson, L.A.;

    2009-01-01

    An extensive parametric analysis shows that the modified Tilted Sandwich Debond (TSD) specimen provides a methodology for characterization of the face/core fracture resistance over a range of mode-mixities. A pilot experimental mixed mode characterization of the fracture toughness of sandwich spe...

  2. Experimental validation of the Higher-Order Theory approach for sandwich panels with flexible core materials

    NARCIS (Netherlands)

    Straalen, IJ.J. van

    2000-01-01

    During tthe 1990's the higher-order theory was developed by Frostig to enable detailed stress analyses of sandwich panel structures. To investigate the potentials of this approach experiments are performed on sandwich panels made of thin steel faces and mineral wool or polystyrene core material. A p

  3. Weld nugget formation in resistance spot welding of new lightweight sandwich material

    DEFF Research Database (Denmark)

    Sagüés Tanco, J.; Nielsen, Chris Valentin; Chergui, Azeddine

    2015-01-01

    Weldability of a new lightweight sandwich material, LITECOR®, by resistance spot welding is analyzed by experiments and numerical simulations. The spot welding process is accommodated by a first pulse squeezing out the non-conductive polymer core of the sandwich material locally to allow metal–me...

  4. Robust and Air-Stable Sandwiched Organo-Lead Halide Perovskites for Photodetector Applications

    KAUST Repository

    Mohammed, Omar F.

    2016-02-25

    We report the simplest possible method to date for fabricating robust, air-stable, sandwiched perovskite photodetectors. Our proposed sandwiched structure is devoid of electron or hole transporting layers and also the expensive electrodes. These simpler architectures may have application in the perovskite-only class of solar cells scaling up towards commercialization.

  5. Transfer of a three step mAb chromatography process from batch to continuous: Optimizing productivity to minimize consumable requirements.

    Science.gov (United States)

    Gjoka, Xhorxhi; Gantier, Rene; Schofield, Mark

    2017-01-20

    The goal of this study was to adapt a batch mAb purification chromatography platform for continuous operation. The experiments and rationale used to convert from batch to continuous operation are described. Experimental data was used to design chromatography methods for continuous operation that would exceed the threshold for critical quality attributes and minimize the consumables required as compared to batch mode of operation. Four unit operations comprising of Protein A capture, viral inactivation, flow-through anion exchange (AEX), and mixed-mode cation exchange chromatography (MMCEX) were integrated across two Cadence BioSMB PD multi-column chromatography systems in order to process a 25L volume of harvested cell culture fluid (HCCF) in less than 12h. Transfer from batch to continuous resulted in an increase in productivity of the Protein A step from 13 to 50g/L/h and of the MMCEX step from 10 to 60g/L/h with no impact on the purification process performance in term of contaminant removal (4.5 log reduction of host cell proteins, 50% reduction in soluble product aggregates) and overall chromatography process yield of recovery (75%). The increase in productivity, combined with continuous operation, reduced the resin volume required for Protein A and MMCEX chromatography by more than 95% compared to batch. The volume of AEX membrane required for flow through operation was reduced by 74%. Moreover, the continuous process required 44% less buffer than an equivalent batch process. This significant reduction in consumables enables cost-effective, disposable, single-use manufacturing. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. TetraMabs: simultaneous targeting of four oncogenic receptor tyrosine kinases for tumor growth inhibition in heterogeneous tumor cell populations

    Science.gov (United States)

    Castoldi, Raffaella; Schanzer, Jürgen; Panke, Christian; Jucknischke, Ute; Neubert, Natalie J.; Croasdale, Rebecca; Scheuer, Werner; Auer, Johannes; Klein, Christian; Niederfellner, Gerhard; Kobold, Sebastian; Sustmann, Claudio

    2016-01-01

    Monoclonal antibody-based targeted tumor therapy has greatly improved treatment options for patients. Antibodies against oncogenic receptor tyrosine kinases (RTKs), especially the ErbB receptor family, are prominent examples. However, long-term efficacy of such antibodies is limited by resistance mechanisms. Tumor evasion by a priori or acquired activation of other kinases is often causative for this phenomenon. These findings led to an increasing number of combination approaches either within a protein family, e.g. the ErbB family or by targeting RTKs of different phylogenetic origin like HER1 and cMet or HER1 and IGF1R. Progress in antibody engineering technology enabled generation of clinical grade bispecific antibodies (BsAbs) to design drugs inherently addressing such resistance mechanisms. Limited data are available on multi-specific antibodies targeting three or more RTKs. In the present study, we have evaluated the cloning, eukaryotic expression and purification of tetraspecific, tetravalent Fc-containing antibodies targeting HER3, cMet, HER1 and IGF1R. The antibodies are based on the combination of single-chain Fab and Fv fragments in an IgG1 antibody format enhanced by the knob-into-hole technology. They are non-agonistic and inhibit tumor cell growth comparable to the combination of four parental antibodies. Importantly, TetraMabs show improved apoptosis induction and tumor growth inhibition over individual monospecific or BsAbs in cellular assays. In addition, a mimicry assay to reflect heterogeneous expression of antigens in a tumor mass was established. With this novel in vitro assay, we can demonstrate the superiority of a tetraspecific antibody to bispecific tumor antigen-binding antibodies in early pre-clinical development. PMID:27578890

  7. Innovative sandwich concepts open up potential for flat structures. Function-integrated lightweight design; Sandwich-Strukturen fuer den funktionsintegrierten Leichtbau. Fahrzeugleichtbau

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Gerhard; Friedrich, Horst E. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Inst. fuer Fahrzeugkonzepte; Kuppinger, Jan [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal (Germany). Abt. Polymer-Engineering; Henning, Frank [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal (Germany). Abt. Polymer-Engineering; DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Kompetenzzentrum; Karlsruher Innovationsclusters ' Technologien fuer den hybriden Leichtbau' (Germany)

    2009-07-01

    Sandwich structures make it possible to achieve an optimum combination of material, form and functional lightweight design. Vehicle weight is reduced and resources are saved. However, such solutions can only be used when the overall concept is cost-effective. For this reason, various DLR and Fraunhofer institutes are currently working on new and cost-effective sandwich structures within the 'Competence Centre for Automotive Lightweight Technology' to further exploit this construction method for flat structures. (orig.)

  8. A Novel Sandwich-type Dinuclear Complex for High-capacity Hydrogen Storage%A Novel Sandwich-type Dinuclear Complex for High-capacity Hydrogen Storage

    Institute of Scientific and Technical Information of China (English)

    朱海燕; 陈元振; 李赛; 曹秀贞; 柳永宁

    2012-01-01

    From density functional theory (DFT) calculations, we predicted that the sandwich-type dinuclear organometallic compounds Cpffi2 and Cp2Sc2 can adsorb up to eight hydrogen molecules respectively, corresponding to a high gravimetric storage capacity of 6.7% and 6.8% (w), respectively. These sandwich-type organometallocenes proposed in this work are favorable for reversible adsorption and desorption of hydrogen at ambient conditions.

  9. Influence of Si buffer layer on the giant magnetoresistance effect in Co/Cu/Co sandwiches

    Institute of Scientific and Technical Information of China (English)

    李冠雄; 沈鸿烈; 沈勤我; 李铁; 邹世昌

    2000-01-01

    The Co/Cu/Co sandwiches with a semiconductor Si buffer layer were prepared by high vacuum electron-beam evaporation. The influence of the Si buffer layer with different thickness on the giant magnetoresistance (GMR) effect in the Co/Cu/Co sandwiches was investigated. It was found that the GMR showed an obvious anisotropy when the thickness of Si buffer layer was larger than or equal to 0.9 nm, and that the GMR was basically isotropic with an Si buffer layer thinner than 0.9 nm. The anisotropic behavior of GMR can be ascribed to the in-plane magnetic anisotropy in the sandwiches. Due to the interdiffusion at the Si buffer/Co interface, a Co2Si interface layer with a good (301) texture formed and induced the in-plane magnetic anisotropy in the sandwiches. The dependence of the crystalline texture of the sandwiches on the thickness of Si buffer layer was also studied.

  10. Unidirectional cloning by cleaving heterogeneous sites with a single sandwiched zinc finger nuclease.

    Science.gov (United States)

    Shinomiya, Kazuki; Mori, Tomoaki; Aoyama, Yasuhiro; Sera, Takashi

    2011-11-04

    We previously developed a novel type of zinc finger nucleases (ZFNs), sandwiched ZFNs that can discriminate DNA substrates from cleavage products and thus cleave DNA much more efficiently than conventional ZFNs as well as perform with multiple turnovers like restriction endonucleases. In the present study, we used the sandwiched ZFN to unidirectionally clone exogenous genes into target vectors by cleaving heterogeneous sites that contained heterogeneous spacer DNAs between two zinc-finger protein binding sites with a single sandwiched ZFN. We demonstrated that the sandwiched ZFN cleaved a 40-fold excess of both insert and vector plasmids within 1h and confirmed by sequencing that the resulting recombinants harbored the inserted DNA fragment in the desired orientation. Because sandwiched ZFNs can recognize and cleave a variety of long (≥ 26-bp) target DNAs, they may not only expand the utility of ZFNs for construction of recombinant plasmids, but also serve as useful meganucleases for synthesis of artificial genomes.

  11. An Optimum Analysis Method of Sandwich Structures Made from Elastic-viscoelastic Materials

    Institute of Scientific and Technical Information of China (English)

    CHEN Ying-bo; XIA Yu; REN Zhi-gang; LU Zhe-an; WANG Er-lei

    2004-01-01

    Due to a viscoelastic damping middle layer,sandwich structures have the capacity of energy consumption.In this paper,we describe the frequency-dependent property of viscoelastic materials using complex modulus model,and iterative modal strain energy method and iterative complex eigenvalue method are presented to obtain frequency and loss factor of sandwich structures.The two methods are effective and exact for the large-scale complex composite sandwich structures.Then an optimum analysis method is suggested to apply to sandwich structures.Finally,as an example,an optimum analysis of a clamped-clamped sandwich beams is conducted,theoretical closed-form solution and numerical predictions are studied comparatively,and the results agree well.

  12. Natural Cork Agglomerate Employed as an Environmentally Friendly Solution for Quiet Sandwich Composites

    Science.gov (United States)

    Sargianis, James; Kim, Hyung-ick; Suhr, Jonghwan

    2012-01-01

    Carbon fiber-synthetic foam core sandwich composites are widely used for many structural applications due to their superior mechanical performance and low weight. Unfortunately these structures typically have very poor acoustic performance. There is increasingly growing demand in mitigating this noise issue in sandwich composite structures. This study shows that marrying carbon fiber composites with natural cork in a sandwich structure provides a synergistic effect yielding a noise-free sandwich composite structure without the sacrifice of mechanical performance or weight. Moreover the cork-core sandwich composites boast a 250% improvement in damping performance, providing increased durability and lifetime operation. Additionally as the world seeks environmentally friendly materials, the harvesting of cork is a natural, renewable process which reduces subsequent carbon footprints. Such a transition from synthetic foam cores to natural cork cores could provide unprecedented improvements in acoustic and vibrational performance in applications such as aircraft cabins or wind turbine blades. PMID:22574250

  13. Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel under Axial Load: An Overview

    Directory of Open Access Journals (Sweden)

    Suryani Samsudin

    2013-02-01

    Full Text Available The development of precast sandwich concrete has gained acceptance worldwide in conjunction with the Industrial Building System (IBS.  The advancement and improvement of using wall panel has gone through a lot of achievements through the last decade. The usage of precast lightweight sandwich panel has become the alternative to conventional construction using brick wall. The usage of this panel system contributes to a sustainable and environmental friendly construction.  This paper presents an overview of the latest development in precast concrete sandwich panel as an IBS. The purpose of this paper is to provide comprehensive information on latest research development of sandwich panel for building construction purposes. The information on sandwich panel’s composition, material, properties, strength, availability, and its usage as structural element are reported.  An innovative concept used in the design of these systems and the use of lightweight materials is also discussed.

  14. Analysis and Behaviour of Sandwich Panels with Profiled Metal Facings under Transverse Load

    Directory of Open Access Journals (Sweden)

    M. Budescu

    2004-01-01

    Full Text Available Sandwich panels with thin steel facings and polyurethane core combine the load-carrying capacity of metal facings and protection functions with core properties. The core separates the two facings and keeps them in a stable condition, transmits shear between external layers, provides most of the shear rigidity and occasionally makes of useful contribution to the bending stiffness of the sandwich construction as a whole [1]. An experimental program on sandwich panels has been organized to prove that the mechanical properties of core and interface satisfy the load-carrying requirements for structural sandwich panels. The analysis of sandwich panels with deep profiles facings for cladding elements, respectively the roof constructions, has been carried out according to the European design norms [1], [5].

  15. Computed tomography with single-shot dual-energy sandwich detectors

    Science.gov (United States)

    Kim, Seung Ho; Youn, Hanbean; Kim, Daecheon; Kim, Dong Woon; Jeon, Hosang; Kim, Ho Kyung

    2016-03-01

    Single-shot dual-energy sandwich detector can produce sharp images because of subtraction of images from two sub-detector layers, which have different thick x-ray converters, of the sandwich detector. Inspired by this observation, the authors have developed a microtomography system with the sandwich detector in pursuit of high-resolution bone-enhanced small-animal imaging. The preliminary results show that the bone-enhanced images reconstructed with the subtracted projection data are better in visibility of bone details than the conventionally reconstructed images. In addition, the bone-enhanced images obtained from the sandwich detector are relatively immune to the artifacts caused by photon starvation. The microtomography with the single-shot dual-energy sandwich detector will be useful for the high-resolution bone imaging.

  16. Fabrication of mAb G250-SPIO molecular magnetic resonance imaging nanoprobe for the specific detection of renal cell carcinoma in vitro.

    Directory of Open Access Journals (Sweden)

    Cailuan Lu

    Full Text Available Molecular magnetic resonance imaging (mMRI has been paid more and more attention for early diagnosis of cancer. A sensitive and specific mMRI probe plays the most important role in this technique. In this study, superparamagnetic iron oxide (SPIO nanoparticles and mAb G250 were conjugated as mMRI probe for the detection of clear cell renal cell carcinoma (ccRCC using 3.0-Tesla MRI in vitro. mAb G250 could specifically recognize carbonic anhydrase IX (CAIX antigen overexpressed in ccRCC and the SPIO nanoparticles as MRI contrast agent presented excellent MRI response and good biocompatibility. The successful assembly of this nanoprobe was confirmed by UV-vis spectrum, FT-IR spectroscopy and DLS analysis. In vitro MRI study on ccRCC cells and control cells indicated that our fabricated mAb G250-SPIO nanoprobe could be used in the specific labeling of clear cell renal carcinoma cells successfully.

  17. Left ventricle remodelling by double-patch sandwich technique

    Directory of Open Access Journals (Sweden)

    Nocchi Andrea

    2007-01-01

    Full Text Available Abstract Background The sandwich double-patch technique was adopted as an alternative method for reconstruction of the left ventricle after excision of postinfarction dysfunctional myocardium to solve technical problems due to the thick edges of the ventricular wall. Methods Over a 5-year period, 12 of 21 patients with postinfarction antero-apical left ventricular aneurysm had thick wall edges after wall excision. It was due to akinetic muscular thick tissue in 6 cases, while in the other 6 with classic fibrous aneurysm, thick edges remained after the cut of the border zone. The ventricular opening was sandwiched between two patches and this is a technique which is currently used for the treatment of the interventricular septum rupture. In our patients the patches are much smaller than the removed aneurysm and they were sutured simply by a single row of single stitches. However, in contrast to interventricular septum rupture where the patches loosen the tension of the tissues, in our patients the patches pull strongly and restrain the walls by fastening their edges and supporting tight stitches. In this way they could narrow the cavity and close the ventricle. Results The resected area varied from 5 × 4 to 8 × 8 cm. Excision was extended into the interventricular septum in 5 patients, thus opening the right ventricle. CABG was performed on all patients but two. Left ventricular volumes and the ejection fraction changed significantly: end-systolic volume 93.5 ± 12.4 to 57.8 ± 8.9 ml, p Conclusion The double-patch sandwich technique (bi-patch closure offers some advantages and does not result in increased morbidity and mortality. In the case of excising a left ventricular aneurysm, this technique in no way requires eversion of the edges, felt strips, buttressed and multiple sutures, all of which are needed for longitudinal linear closure. Moreover, it does not require purse string sutures, endocardial scar remnant to secure the patch or

  18. Communique: Special Issue on the International Scientific Conference and Exhibit and the 7th Session of the International Co-Ordinating Council for MAB (Paris, Sept. 22-Oct. 2, 1981) = Numero special sur la Conference Scientifique Internationale et Exposition et al 7e session du Counseil International de Coordination du MAB (Paris, du 22 Sept. au 2 Oct. 1981).

    Science.gov (United States)

    Communique, 1982

    1982-01-01

    Presented are summaries of two separate but closely-related conferences. The International Scientific Conference and Exhibit, organized to mark the 10th anniversary of the Man and the Biosphere Program (MAB), was based on the theme "ecology in practice: establishing a scientific basis for land management." This summary includes: a 10…

  19. 浅析Sandwich 教学法

    Institute of Scientific and Technical Information of China (English)

    田志逢

    2012-01-01

    为了真正实现学生为主体教师为主导的教学模式,我们把Sandwich 教学法引入课堂教学中.从教学内容的选取、课堂的设计、问题的设置、学生的分组、教师的总结等各个环节精心的安排,使得学生积极参与课堂,把课堂真正的交还给学生,从而积极有效的提高了学生学习的兴趣、动力,大幅度提高了教学效果.

  20. Bilateral sandwiched scapulae: A rare presentation of hereditary multiple exostoses.

    Science.gov (United States)

    Mozaffarian, Kamran; Farahani, Mohammad Javad; Vosoughi, Amir Reza

    2016-01-01

    Hereditary multiple exostoses, an autosomal dominant condition, is a common benign tumor which is characterized by the development of multiple osteochondromas. Bilateral dorsal and ventral involvement of scapulae is extremely rare without any reported case in the literature. An 18-year-old girl was referred because of bilateral prominent scapulae and left-sided pain on shoulder girdle motion especially at more than 90° abduction and forward flexion. Radiograph evaluation showed multiple exostoses on ventral and dorsal surfaces of body of both scapulae; hence simple excision of the lesion was impossible. The patient was symptom-free about 18 months after partial scapulectomy of left side. Partial scapulectomy seems to be an effective treatment for the sandwiched scapula between dorsal and ventral benign tumors.

  1. Smearing of chaos in sandwich pp-waves

    CERN Document Server

    Podolsky, J

    1999-01-01

    Recent results demonstrating the chaotic behavior of geodesics in non-homogeneous vacuum pp-wave solutions are generalized. Here we concentrate on motion in non-homogeneous sandwich pp-waves and show that chaos smears as the duration of these gravitational waves is reduced. As the number of radial bounces of any geodesic decreases, the outcome channels to infinity become fuzzy, and thus the fractal structure of the initial conditions characterizing chaos is cut at lower and lower levels. In the limit of impulsive waves, the motion is fully non-chaotic. This is proved by presenting the geodesics in a simple explicit form which permits a physical interpretation, and demonstrates the focusing effect. It is shown that a circle of test particles is deformed by the impulse into a family of closed hypotrochoidal curves in the transversal plane. These are deformed in the longitudinal direction in such a way that a specific closed caustic surface is formed.

  2. Analytical modeling of sandwich beam for piezoelectric bender elements

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Piezoelectric bender elements are widely used as electromechanical sensors and actuators. An analytical sandwich beam model for piezoelectric bender elements was developed based on the first-order shear deformation theory (FSDT), which assumes a single rotation angle for the whole cross-section and a quadratic distribution function for coupled electric potential in piezoelectric layers, and corrects the effect of transverse shear strain on the electric displacement integration. Free vibration analysis of simplysupported bender elements was carried out and the numerical results showed that, solutions of the present model for various thickness-to-length ratios are compared well with the exact two-dimensional solutions, which presents an efficient and accurate model for analyzing dynamic electromechanical responses of bender elements.

  3. Electrowetting-driven oscillating drops sandwiched between two substrates.

    Science.gov (United States)

    Mampallil, Dileep; Eral, H Burak; Staicu, Adrian; Mugele, Frieder; van den Ende, Dirk

    2013-11-01

    Drops sandwiched between two substrates are often found in lab-on-chip devices based on digital microfluidics. We excite azimuthal oscillations of such drops by periodically modulating the contact line via ac electrowetting. By tuning the frequency of the applied voltage, several shape modes can be selected one by one. The frequency of the oscillations is half the frequency of the contact angle modulation by electrowetting, indicating a parametric excitation. The drop response to sinusoidal driving deviates substantially from sinusoidal behavior in a "stop and go" fashion. Although our simple theoretical model describes the observed behavior qualitatively, the resonances appear at lower frequencies than expected. Moreover, the oscillations produce a nonperiodic fluid transport within the drop with a typical velocity of 1 mm/s. In digital microfluidic devices, where the typical drop size is less than 1 mm, this flow can result in very fast mixing on the spot.

  4. FMR studies of single permalloy layers sandwiched by Au

    Energy Technology Data Exchange (ETDEWEB)

    Hurdequint, H. [Laboratoire de Physique des Solides, UMR 8502, Universite Paris-Sud, 91405 ORSAY Cedex (France)]. E-mail: hurdequint@lps.u-psud.fr

    2007-03-15

    Results of FMR studies performed at X-band on two series of thin permalloy (Py) layers sandwiched by Au are reported and analyzed. These two series are characterized by an Au layer thickness of 12 and 6 nm, respectively. The FMR results are compared to the ones obtained for a series of (Py/Al{sub 2}O{sub 3}) control films. A strong interfacial increase of the intrinsic damping is revealed. The spin-orbit perpendicular anisotropy field is also dominated by the metallic interface contribution. Remarkable phenomena evidenced in the angular variation of the FMR spectrum may be well understood in terms of the theoretical description we have developed of the observable signal in a bimetallic (ferro/normal) film.

  5. Standard Test Method for Laboratory Aging of Sandwich Constructions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This test method covers the determination of the resistance of sandwich panels to severe exposure conditions as measured by the change in selected properties of the material after exposure. The exposure cycle to which the specimen is subjected is an arbitrary test having no correlation with natural weathering conditions. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Electrowetting-driven oscillating drops sandwiched between two substrates

    Science.gov (United States)

    Mampallil, Dileep; Burak Eral, H.; Staicu, Adrian; Mugele, Frieder; van den Ende, Dirk

    2013-11-01

    Drops sandwiched between two substrates are often found in lab-on-chip devices based on digital microfluidics. We excite azimuthal oscillations of such drops by periodically modulating the contact line via ac electrowetting. By tuning the frequency of the applied voltage, several shape modes can be selected one by one. The frequency of the oscillations is half the frequency of the contact angle modulation by electrowetting, indicating a parametric excitation. The drop response to sinusoidal driving deviates substantially from sinusoidal behavior in a “stop and go” fashion. Although our simple theoretical model describes the observed behavior qualitatively, the resonances appear at lower frequencies than expected. Moreover, the oscillations produce a nonperiodic fluid transport within the drop with a typical velocity of 1 mm/s. In digital microfluidic devices, where the typical drop size is less than 1 mm, this flow can result in very fast mixing on the spot.

  7. Mechanical properties and experimental researches of new CSIPs sandwich panels

    Directory of Open Access Journals (Sweden)

    Du Wenfeng

    2017-01-01

    Full Text Available The advantages of glass fiber reinforced composites (FRP and SIPs (structural insulated panels are combined, and a new type of sandwich panel called composite structural insulated panels (CSIPs is proposed. Through the adhesive bonding, CSIPs are made of FRP as face sheets and expanded polyethylene foam (EPS as a core. To master the mechanical characteristics of CSIPs, firstly, adopting the large deflection theory of Reissener in this paper derived the calculation formula of displacement and the stability critical load of CSIPs. Then, ANSYS software was used to carry on the analysis of finite element simulation. Finally, a testing piece of CSIP with length 1000mm and breath 1000mm was made and a test was done. The results show that the theoretical analysis results, finite element simulation results and test results are basically coincide. So the calculating formula of deformation and bearing capacity of CSIPs are correct. And CSIPs have the outstanding advantages of light weight and high strength.

  8. Applications of thin-film sandwich crystallization platforms.

    Science.gov (United States)

    Axford, Danny; Aller, Pierre; Sanchez-Weatherby, Juan; Sandy, James

    2016-04-01

    Examples are shown of protein crystallization in, and data collection from, solutions sandwiched between thin polymer films using vapour-diffusion and batch methods. The crystallization platform is optimal for both visualization and in situ data collection, with the need for traditional harvesting being eliminated. In wells constructed from the thinnest plastic and with a minimum of aqueous liquid, flash-cooling to 100 K is possible without significant ice formation and without any degradation in crystal quality. The approach is simple; it utilizes low-cost consumables but yields high-quality data with minimal sample intervention and, with the very low levels of background X-ray scatter that are observed, is optimal for microcrystals.

  9. Prediction of the ballistic limit of an aluminium sandwich panel

    Science.gov (United States)

    Campbell, J.; De Vuyst, T.; Vignjevic, R.; Hughes, K.

    2016-08-01

    This paper presents research on modelling the impact of a 150g projectile on a 35mm thick aluminium sandwich panel. The objective of the work is a predictive modelling capability for the ballistic limit of the panel. A predictive modelling capability supports the design of capture and deorbit missions for large items of space debris such as satellites and rocket upper stages. A detailed explicit finite element model was built using the LSDYNA software and results were compared with experimental data for the projectile exit velocity to establish key parameters. The primary parameters influencing the model behaviour were the strength and failure of the aluminium face sheets and the friction between projectile and panel. The model results showed good agreement with experimental results for ogive nose projectiles, but overestimated the exit velocity for flat nose projectiles.

  10. Predicting The Compression Strength Of Impact-Damaged Sandwich Panels

    Science.gov (United States)

    Ratcliffe, James; Jackson, Wade; Schaff, Jeffery

    1990-01-01

    The objective of this work was to develop a technique for predicting the residual compression strength of sandwich panels containing impact damage in one facesheet. The technique was tailored to predict the strength of specimens that exhibit a failure mode involving the formation of kink bands at locations of peak strain in the region of impact damage. Under continued compression loading, the kink bands propagate in a stable manner perpendicular to the applied load. When a critical kink-band length is reached, growth becomes unstable corresponding to panel failure. The analysis follows in two sections. The first section calculates the far-field stress required for stable kink-band growth and the second calculates that required for unstable growth. The residual strength prediction is made when the stress for stable growth becomes equal to that for unstable kink-band growth. Initial comparisons between analysis and experiment show good agreement.

  11. Immunometric Antibody Sandwich Enzyme-Linked Immunosorbent Assay.

    Science.gov (United States)

    Kohl, Thomas O; Ascoli, Carl A

    2017-06-01

    The antibody sandwich enzyme-linked immunosorbent assay (ELISA) is the most commonly used assay for rapid and accurate detection of antigens. It displays greater sensitivity compared with the indirect ELISA and can be used to determine absolute antigen concentrations in unknown samples provided purified antigen standards are available, although it requires the use of two different antibodies. Briefly, wells are coated with antigen-specific capture antibody then incubated with samples containing unknown antigen. Washing removes unbound antigen and exogenous sample protein before incubation with a second antigen-specific detection antibody, washing, and reincubation with a reporter-labeled tertiary antibody. After tertiary antibody is washed off, substrate is added and hydrolysis is measured spectrophotometrically. The signal intensity is directly proportional to the concentration of the antigen in the test sample. © 2017 Cold Spring Harbor Laboratory Press.

  12. On-Surface Synthesis of Sandwich Molecular Nanowires on Graphene.

    Science.gov (United States)

    Huttmann, Felix; Schleheck, Nicolas; Atodiresei, Nicolae; Michely, Thomas

    2017-07-26

    We demonstrate a new synthesis route for the growth of organometallic sandwich molecular nanowires, taking the example of Eu-cyclooctatetraene (EuCot), a predicted ferromagnetic semiconductor. We employ simultaneous exposure of Cot molecules and Eu vapor in ultrahigh vacuum to an inert substrate, such as graphene. Using a Cot excess under temperature conditions of a finite residence time of the molecule, the reactand diffusion confined to two dimensions results in a clean product of ultralong wires. In situ scanning tunneling microscopy reveals not only their molecular structure but also a rich and intriguing growth morphology. The new on-surface synthesis permits experimental access to a largely unexplored class of one-dimensional organometallic systems with potential for exciting electronic and magnetic properties.

  13. Morphology Analysis of Cu Film Fractures in Sandwiched Methylmethacrylate Plates

    Directory of Open Access Journals (Sweden)

    Cristiano Fidani

    2015-06-01

    Full Text Available Thin films of Cu were evaporated on solid plates of polymethylmethacrylate (PMMA. A polymerization process was made to realize sandwiched structure to protect the Cu films. Fracturing of the metal film surface was observed with several morphologies showing two different fracture systems. Surface film morphology was analysed in terms of the distribution area of the islands and contour fractal dimension. The island areas showed a maximum corresponding to 42 nm of the Cu thickness, it was also the threshold to observe the second fracture system. The fractures pattern resulted to be scale invariant with fractal dimensions between 1.55 and 1.7. The minimum fractal dimension also occurred at the film thickness corresponding to the maximum island area. The reported effects can be understood on the basis of different thermal expansion coefficients of the two materials and their thermally induced adhesion.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.6518

  14. Equivariant Equipartitions: Ham Sandwich Theorems for Finite Subgroups of Spheres

    CERN Document Server

    Simon, Steven

    2011-01-01

    Equivariant "Ham Sandwich" Theorems are obtained for the finite subgroups of the unit spheres S^{d-1}, d=1,2,4. Given any F-valued mass distributions on F^n and any non-zero finite subgroup G of the unit sphere S^{d-1} in F= R, C, or H, it is shown that there exists a collection of fundamental G-regions partitioning F^n which "G-Equipartition" each of the n measures, as realized by the simultaneous vanishing of the "G-averages" of the regions' measures. Equipartition results for real measures follow, among them that any n signed mass distributions on R^{(p-1)n} can be equipartitioned by a single regular p-fan for any prime number p.

  15. Nondestructive and Strain Testing of Composite Sandwich Panels

    Science.gov (United States)

    Goyings, Ryan

    In April 2006, Sikorsky Aircraft received a contract from the United States Marine Corps (USMC) to develop a successor to their CH-53E heavy-lift helicopter. The new designation is the CH-53K "Super Stallion" and provides increased operating capabilities through the use of design revisions that incorporate extensive use of carbon fiber composites and composite sandwich panels. "The CH-53K will have five times the capability at half of the operational cost of the aircraft it's replacing. It will be the most capable helicopter ever produced. With more than twice the combat radius of the CH-53E, the CH-53K uses mature technology to deliver a fully shipboard compatible platform to meet current and future Marine Corps requirements". Upon introduction, it will be the largest rotary wing aircraft in the United States Department of Defense. The USMC will incorporate the CH-53K into the Joint Operations Concept of Full Spectrum Dominance and Sea Power 21 thereby enabling rapid, decisive operations and the early termination of conflict by projecting and sustaining forces to distant anti-access, area-denial environments. Even with an increased lift capability, the CH-53K is a slow moving, low flying helicopter susceptible to damage from small arms fire. There is no field level composite repair capability within any maintained documents published by the Department of Defense. Purdue University has developed a field level rapid repair technique capable of returning strength and integrity to damaged carbon composite structural components. The patch is made from carbon fiber weave that is applied using a field capable Vacuum Assisted Resin Transfer Molding (VARTM). This thesis seeks to validate, using nondestructive testing methods and strain monitoring, the manufacturing, damage, and repair process of composite sandwich panels representative of the CH-53K structural panels.

  16. Probabilistic Structural Evaluation of Uncertainties in Radiator Sandwich Panel Design

    Science.gov (United States)

    Kuguoglu, Latife; Ludwiczak, Damian

    2006-01-01

    The Jupiter Icy Moons Orbiter (JIMO) Space System is part of the NASA's Prometheus Program. As part of the JIMO engineering team at NASA Glenn Research Center, the structural design of the JIMO Heat Rejection Subsystem (HRS) is evaluated. An initial goal of this study was to perform sensitivity analyses to determine the relative importance of the input variables on the structural responses of the radiator panel. The desire was to let the sensitivity analysis information identify the important parameters. The probabilistic analysis methods illustrated here support this objective. The probabilistic structural performance evaluation of a HRS radiator sandwich panel was performed. The radiator panel structural performance was assessed in the presence of uncertainties in the loading, fabrication process variables, and material properties. The stress and displacement contours of the deterministic structural analysis at mean probability was performed and results presented. It is followed by a probabilistic evaluation to determine the effect of the primitive variables on the radiator panel structural performance. Based on uncertainties in material properties, structural geometry and loading, the results of the displacement and stress analysis are used as an input file for the probabilistic analysis of the panel. The sensitivity of the structural responses, such as maximum displacement and maximum tensile and compressive stresses of the facesheet in x and y directions and maximum VonMises stresses of the tube, to the loading and design variables is determined under the boundary condition where all edges of the radiator panel are pinned. Based on this study, design critical material and geometric parameters of the considered sandwich panel are identified.

  17. Experimental study of the mechanical behaviour of pin reinforced foam core sandwich materials under shear load

    Science.gov (United States)

    Dimassi, M. A.; Brauner, C.; Herrmann, A. S.

    2016-03-01

    Sandwich structures with a lightweight closed cell hard foam core have the potential to be used in primary structures of commercial aircrafts. Compared to honeycomb core sandwich, the closed cell foam core sandwich overcomes the issue of moisture take up and makes the manufacturing of low priced and highly integrated structures possible. However, lightweight foam core sandwich materials are prone to failure by localised external loads like low velocity impacts. Invisible cracks could grow in the foam core and threaten the integrity of the structure. In order to enhance the out-of-plane properties of foam core sandwich structures and to improve the damage tolerance (DT) dry fibre bundles are inserted in the foam core. The pins are infused with resin and co-cured with the dry fabric face sheets in an out-of-autoclave process. This study presents the results obtained from shear tests following DIN 53294-standard, on flat sandwich panels. All panels were manufactured with pin-reinforcement manufactured with the Tied Foam Core Technology (TFC) developed by Airbus. The effects of pin material (CFRP and GFRP) and pin volume fraction on the shear properties of the sandwich structure and the crack propagation were investigated and compared to a not pinned reference. It has been concluded that the pin volume fraction has a remarkable effect on the shear properties and damage tolerance of the observed structure. Increasing the pin volume fraction makes the effect of crack redirection more obvious and conserves the integrity of the structure after crack occurrence.

  18. Combined compressive and shear buckling analysis of hypersonic aircraft sandwich panels

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1992-01-01

    The combined-load (compression and shear) buckling equations were established for orthotropic sandwich panels by using the Rayleigh-Ritz method to minimize the panel total potential energy. The resulting combined-load buckling equations were used to generate buckling interaction curves for super-plastically-formed/diffusion-bonded titanium truss-core sandwich panels and titanium honeycomb-core sandwich panels having the same specific weight. The relative combined-load buckling strengths of these two types of sandwich panels are compared with consideration of their sandwich orientations. For square and nearly square panels of both types, the combined load always induces symmetric buckling. As the panel aspect ratios increase, antisymmetric buckling will show up when the loading is shear-dominated combined loading. The square panel (either type) has the highest combined buckling strength, but the combined load buckling strength drops sharply as the panel aspect ratio increases. For square panels, the truss-core sandwich panel has higher compression-dominated load buckling strength. However, for shear dominated loading, the square honeycomb-core sandwich panel has higher shear-dominated combined load buckling strength.

  19. Combined compressive and shear buckling analysis of hypersonic aircraft structural sandwich panels

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1991-01-01

    The combined-load (compression and shear) buckling equations were established for orthotropic sandwich panels by using the Rayleigh-Ritz method to minimize the panel total potential energy. The resulting combined-load buckling equations were used to generate buckling interaction curves for super-plastically-formed/diffusion-bonded titanium truss-core sandwich panels and titanium honeycomb-core sandwich panels having the same specific weight. The relative combined-load buckling strengths of these two types of sandwich panels are compared with consideration of their sandwich orientations. For square and nearly square panels of both types, the combined load always induces symmetric buckling. As the panel aspect ratios increase, antisymmetric buckling will show up when the loading is shear-dominated combined loading. The square panel (either type) has the highest combined buckling strength, but the combined load buckling strength drops sharply as the panel aspect ratio increases. For square panels, the truss-core sandwich panel has higher compression-dominated combined load buckling strength. However, for shear dominated loading, the square honeycomb-core sandwich panel has higher shear-dominated combined load buckling strength.

  20. EFFECT OF DIVIDED CORE ON THE BENDING PERFORMANCES OF TEXTILE REINFORCED FOAM CORE SANDWICH COMPOSITES

    Directory of Open Access Journals (Sweden)

    ALPYILDIZ Tuba

    2016-05-01

    Full Text Available Sandwich composites are generally used in marine applications, wind turbines, space and aircraft vehicles due to their high bending rigidities in addition to their lighter weights. The objective of this study is to investigate the effect of divided foam core and interlayer sheet of glass fabric on the bending performances of sandwich composites which are manufactured with glass fabrics as the facesheets/interlayer sheets and PVC foam as the core material. Sandwich composites with single and divided core are manufactured and compared in terms of flexural behavious via three point bending tests. It is found that the bending performance is enhanced with the use of divided core and using divided core does not affect the behaviour of the sandwich composite against bending deformations. In the case of the plain core sandwich composite, dividing the core is advised for certain applications rather than perforating the core to increase the bending stiffness and strength of the textile reinforced sandwich composites because it is possible to purchase core with any thickness and there is no need for additional process such as perforation. The proposed application could enhance the bending performances without altering the weight and cost of the sandwich composites, which are preferred due to their higher bending rigidities in relation to their lighter weights.

  1. Sandwich Structure-like Meshes Fabricated via Electrospinning for Controllable Release of Zoledronic Acid

    Institute of Scientific and Technical Information of China (English)

    LU Jian; LIU Jian-guo; SONG Xiao-feng; CHEN Xue-si; WU Xiao-dong

    2011-01-01

    Novel sandwich structure-like nanofiber multilayered meshes were fabricated via electrospinning. The purpose of the present work was to control zoledronic acid release via the novel structure of sandwich structure-like meshes. The in vitro release experiments reveal that the drug release speed and initial burst release were controllable by adjusting the thicknesses of electrospun barrier mesh and drug-loaded mesh. Compared with those of other drug delivery systems, the main advantages of the sandwich structure-like fiber meshes are facile preparation conditions and the generality for hydrophobic and hydrophilic pharmaceuticals.

  2. Modelling of Debond and Crack Propagation in Sandwich Structures Using Fracture and Damage Mechanics

    DEFF Research Database (Denmark)

    Berggreen, C.; Simonsen, Bo Cerup; Toernqvist, Rikard

    2003-01-01

    Skin-core de-bonding or core crack propagation will often be dominating mechanisms in the collapse modes of sandwich structures. This paper presents two different methods for prediction of crack propagation in a sandwich structure: a fracture mechanics approach, where a new mode-mix method...... is presented, and a local damage mechanics approach. The paper presents a real-life application example, where the superstructure in a vessel pulls the skin off the sandwich deck. The calculations show almost unstable crack growth initially followed by a stabilization, and a nearly linear relation between...

  3. Improving Performance of Polymer Fiber Reinforced Sandwich X-Joints in Naval Vessels

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Berggreen, Christian; Karlsen, Kasper;

    2007-01-01

    This study deals with damage tolerance of sandwich X-joints with embedded debond damages between face and core. The study is conducted both through modeling and full-scale tests. Mixed mode cohesive laws from the opening of sandwich interfaces are determined experimentally from a DCB specimen...... loaded by moments, and the results are utilized in a cohesive zone model of a tested sandwich structure. Results of the crack propagation from experiments and simulation show fair agreement. Design aspects regarding the influence of debond size and core inserts on the residual strength are discussed....

  4. A comparative study of the impact properties of sandwich materials with different cores

    Directory of Open Access Journals (Sweden)

    Viot P.

    2012-08-01

    Full Text Available Sandwich panels are made of two high strength skins bonded to either side of a light weight core and are used in applications where high stiffness combined with low structural weight is required. The purpose of this paper is to compare the mechanical response of several sandwich panels whose core materials are different. Sandwich panels with glass fibre-reinforced polymer face sheets were used, combined with five different cores; polystyrene foam, polypropylene honeycomb, two different density Balsa wood and Cork. All specimens were subjected to low velocity impact and their structural response (Force-displacement curves were compared to quasistatic response of the panel tested using an hemispherical indenter.

  5. Design Considerations for Thermally Insulating Structural Sandwich Panels for Hypersonic Vehicles

    Science.gov (United States)

    Blosser, Max L.

    2016-01-01

    Simplified thermal/structural sizing equations were derived for the in-plane loading of a thermally insulating structural sandwich panel. Equations were developed for the strain in the inner and outer face sheets of a sandwich subjected to uniaxial mechanical loads and differences in face sheet temperatures. Simple equations describing situations with no viable solution were developed. Key design parameters, material properties, and design principles are identified. A numerical example illustrates using the equations for a preliminary feasibility assessment of various material combinations and an initial sizing for minimum mass of a sandwich panel.

  6. The Influence of Face Sheet Wrinkle Defects on the Performance of FRP Sandwich Structures

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Carl Christian; Pettersson, Robert

    2005-01-01

    reported here, the influence of wrinkle defects on the in-plane compressive strength of quasiisotropic CFRP laminates used in PVC foam-cored sandwich panels has been investigated by three approaches: testing of sandwich beam specimens in fourpoint bending, testing of sandwich panels with in......Wrinkle defects may reduce the compressive strength of a face laminate for inplane loading applied perpendicularly to the line of the wrinkle. To be able to decide whether a repair is needed it is necessary to know the magnitude of the strength reduction for a given wrinkle geometry. In the studies...

  7. A comparative study of the impact properties of sandwich materials with different cores

    Science.gov (United States)

    Ramakrishnan, K. R.; Shankar, K.; Viot, P.; Guerard, S.

    2012-08-01

    Sandwich panels are made of two high strength skins bonded to either side of a light weight core and are used in applications where high stiffness combined with low structural weight is required. The purpose of this paper is to compare the mechanical response of several sandwich panels whose core materials are different. Sandwich panels with glass fibre-reinforced polymer face sheets were used, combined with five different cores; polystyrene foam, polypropylene honeycomb, two different density Balsa wood and Cork. All specimens were subjected to low velocity impact and their structural response (Force-displacement curves) were compared to quasistatic response of the panel tested using an hemispherical indenter.

  8. The pleural sandwich sign in two cases of primary pleural lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoo Kyung; Lee, Myung Jae; Ryu, Yon Ju; Cho, Min Sun [School of Medicine, Ewha Womans University, Seoul (Korea, Republic of)

    2015-02-15

    The sandwich sign is used to describe mesenteric lymphoma in which mesenteric vessels and fat are enveloped by enlarged mesenteric lymph nodes. We present two cases of primary pleural lymphoma demonstrating the 'pleural sandwich sign'. Contrast-enhanced computed tomography showed conglomerated parietal pleural and extrapleural masses encasing the intercostal arteries. Histopathological examinations confirmed low grade marginal zone B-cell lymphoma in an 80-year-old man and diffuse large B-cell lymphoma in a 68-year-old man. The pleural sandwich sign may suggest the diagnosis of primary pleural lymphoma.

  9. Elastic constants for superplastically formed/diffusion-bonded corrugated sandwich core

    Science.gov (United States)

    Ko, W. L.

    1980-01-01

    Formulas and associated graphs for evaluating the effective elastic constants for a superplastically formed/diffusion bonded (SPF/DB) corrugated sandwich core, are presented. A comparison of structural stiffnesses of the sandwich core and a honeycomb core under conditions of equal sandwich core density was made. The stiffness in the thickness direction of the optimum SPF/DB corrugated core (that is, triangular truss core) is lower than that of the honeycomb core, and that the former has higher transverse shear stiffness than the latter.

  10. Effects of interleukin-18 and Anti-interleukin-18-mAb on Experimental immunological Liver Fibrosis induced by Repeatedly Administered Concanavalin A and its Mechanism

    Institute of Scientific and Technical Information of China (English)

    You-wen Tan; Jian-cheng Wu; Yun Ye; Li Chen; Peng-li Pai

    2014-01-01

    Objective To explore the prevention of IL-18 or anti-IL-18-mAb to the immune liver fibrosis model induced by repeated injection of concanavalin A in BALB/c mice and its mechanism. Methods Total of 120 BALB/c mice were divided into four groups, control group mice (Ga) were injected weekly with normal saline, concanavalin A group was divided into Gb, Gc, Gd. All mice were injected with concanavalin A (15 mg/kg) once a week. Moreover, Gc, Gd mice were injected weekly with IL-18 (7.5 mg/kg) and anti-IL-18-mAb (10 mg/kg) 2 hours before treatment with concanavalin A, respectively. Twenty-four hours after concanavalin A challenge at 1, 5, 12 and 20 weeks, 3 mice were killed by vena orbitalis, repectively. The sera were storaged at 4℃for detecting of up TNF-αand IFN-γby ELISA. The liver of mice in different groups were excised and fixed in 10%formalin for HE staining and Masson staining or frozen in liquid nitrogen for immunohistochemical staining forα-SMA. After extracting of total RNA from liver tissue, MMP-2 and TIMP-1 A messenger RNA were amplified by reverse transcription polymerase chain reaction (PCR). Products were electrophoresed on agrose gel containing ethidium bromide and visualized under ultraviolet light. Densitometric RT-PCR data were standardized withβ-actin signals. Results After experiment, the number of dead mice of Ga, Gb, Gc and Gd were 0, 6, 15 and 3, respectively. There were significant difference on each group (P<0.05). At the fifth week of experiment, hepatocellular necrosis in IL-18 administered group mice had become widespread throughout the lobule. Evidence of liver fibrosis was observed during this period. However, at the twelfth week of experimemt, bridging fibrosis and large fibrosis strip in the parenchyma with hepatocellular necrosis was detectable in Gb, but at twentieth week, only the small fibrosis strip had been found in anti-IL-18-mAb administered group mice by HE staining and Masson staining. The serum levels of TNF-αand IFN

  11. Fabrication and Characterization of Li-6 Sandwich Detector

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kiwhan [Future and Challenge Technology Co., Yongin (Korea, Republic of); Iliev, Metodi; Ianakiev, Kiril; Swinhoe, Martyn [Los Alamos National Laboratory, New Mexico (United States)

    2014-10-15

    Lithium-6 has been used as a radiation detector material for its ability to react with thermal neutrons, producing alphas and tritons as the primary charged particles during the neutron conversion reaction. Lithium-6 has a thermal neutron cross section of 940 barns, producing a 2.05 MeV alpha particle and a 2.73 MeV triton in a back to back symmetry to conserve energy and momentum, if the incident thermal neutron has low energy. The most widely recognized thermal neutron conversion reaction involves He-3. A He-3 atom has a thermal neutron cross section of 5330 barns, but its resulting particles have total 0.764 MeV to share between a proton and triton. The use of He-3 gas is not limited to homeland security and international safe-guards programs; the high energy physics and medical communities all benefit from the unique capabilities of He-3. As fission neutrons enter the sandwich medium consisting of light guides, plastic scintillator, and lithium-6 foil, they lose energy in the volume. Some neutrons are reduced to thermal energy range and interact with lithium-6 atoms, producing a triton and an alpha particle during the reaction. The primary charged particles then impart their energies in the plastic scintillator film, producing photons. The photons then travels toward the ends of the light guide strips and get collected by the PMTs. Initially, the lithium-6 metal was in storage for many years at the Y-12 National Security Complex, Oak Ridge, Tenneessee, and the metal piece needed reprocessing as shown in Fig. 3. The piece was transported to a lithium battery production facility which had the capability to reprocess lithium ingots. After the metal was reprocessed, it was purified to 95% enrichment and regained sheen (Fig. 4). The foil was extruded as 50-micron, 5 cm-wide strips as shown in inset of Fig. 4. The rolls were stored in an airtight pouch which was filled with dry argon and sealed in a metal container capable of withstanding long term storage as shown

  12. Twistable and bendable actuator: a CNT/polymer sandwich structure driven by thermal gradient.

    Science.gov (United States)

    Seo, Dong Kyun; Kang, Tae June; Kim, Dae Weon; Kim, Yong Hyup

    2012-02-24

    We demonstrate a novel configuration of an electrothermal actuator (ETA), which is based on a polydimethylsiloxane (PDMS) slab sandwiched by upper and lower active layers of CNT-PDMS composite. When only one active layer of a single sandwich structure ETA is heated and the other is not, there exists a thermal gradient in the direction of the slab thickness, resulting in bending motion toward the unheated side. Moreover, a dual sandwich structure ETA, consisting of two parallel assembled sandwich structures on the same body, has the unique ability to act with a twisting motion as the two ETAs bend in opposite directions. We expect the advent of the bendable and twistable actuator to break new ground in ETAs.

  13. Novel sandwich structure adsorptive membranes for removal of 4-nitrotoluene from water

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yuexin [College of Chemistry, Beijing Normal University, Beijing 100875 (China); School of Pharmacy, North China University of Science and Technology, Tangshan 063000 (China); Jia, Zhiqian, E-mail: zhqjia@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2016-11-05

    Highlights: • Novel sandwich PES-SPES/PS-PDVB/PTFE adsorptive membranes were prepared. • The removal efficiency for 4-nitrotoluene is greater than 95% after five recycles. • The membrane showed higher adsorption capacity than that of mixed matrix membrane. - Abstract: Novel sandwich PES-SPES/PS-PDVB/PTFE adsorptive membranes were prepared by a filtration/immersion precipitation method and employed for the removal of 4-nitrotoluene from water. The static adsorption thermodynamics, kinetics, dynamic adsorption/desorption and membrane reusability were investigated. The results showed that the Freundlich model describes the adsorption isotherm satisfactorily. With increased PS-PDVB content, the maximum static adsorption capacity, partition coefficient, apparent adsorption rate constant, and dynamic adsorption capacity all significantly increased. The sandwich membranes showed much higher removal efficiency and adsorption capacity than those of mixed matrix membranes. With respect to dynamics adsorption/desorption, the sandwich membranes exhibited excellent reusability, with a removal efficiency greater than 95% even after five recycles.

  14. A variable transverse stiffness sandwich structure using fluidic flexible matrix composites (F2MC)

    Science.gov (United States)

    Li, Suyi; Lotfi, Amir; Shan, Ying; Wang, K. W.; Rahn, Christopher D.; Bakis, Charles E.

    2008-03-01

    Presented in this paper is the development of a novel honeycomb sandwich panel with variable transverse stiffness. In this structure, the traditional sandwich face sheets are replaced by the fluidic flexible matrix composite (F2MC) tube layers developed in recent studies. The F2MC layers, combined with the anisotropic honeycomb core material properties, provide a new sandwich structure with variable stiffness properties for transverse loading. In this research, an analytical model is derived based on Lekhitskii's anisotropic pressurized tube solution and Timoshenko beam theory. Experimental investigations are also conducted to verify the analytical findings. A segmented multiple-F2MC-tube configuration is synthesized to increase the variable stiffness range. The analysis shows that the new honeycomb sandwich structure using F2MC tubes of 10 segments can provide a high/low transverse stiffness ratio of 60. Segmentation and stiffness control can be realized by an embedded valve network, granting a fast response time.

  15. Blast-Resistant Improvement of Sandwich Armor Structure with Aluminum Foam Composite

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2013-01-01

    Full Text Available Sandwich armor structures with aluminum foam can be utilized to protect a military vehicle from harmful blast load such as a landmine explosion. In this paper, a system-level dynamic finite element model is developed to simulate the blast event and to evaluate the blast-resistant performance of the sandwich armor structure. It is found that a sandwich armor structure with only aluminum foam is capable of mitigating crew injuries under a moderate blast load. However, a severe blast load causes force enhancement and results in much worse crew injury. An isolating layer between the aluminum foam and the vehicle floor is introduced to remediate this drawback. The results show that the blast-resistant capability of the innovative sandwich armor structure with the isolating layer increases remarkably.

  16. Theoretical Calculation and Analysis of Slip and Deformation for Concrete Sandwich Panels

    Institute of Scientific and Technical Information of China (English)

    LI Yanbo; ZHANG Shaohua; XIA Baoyang

    2007-01-01

    Slip and deformation of concrete sandwich panels under uniformly distributed loads is concerned. The effect of slip on the deformation of concrete sandwich panels are studied, and the analytical expressions of slip and deformation for concrete sandwich panels is obtained. These formulae can describe the slip distribution and account for its effect on deformation. In order to restrict the bound of formula, the formula of crack moment is obtained. The results of theoretical calculation are compared with those of tests and finite element methods. The comparison shows that the results of theoretical calculation are in accord with those of tests and finite element methods. So the theoretical calculation can be used to calculate slip and deformation of concrete sandwich panels in practical projects.

  17. Analytical study of sandwich structures using Euler-Bernoulli beam equation

    Science.gov (United States)

    Xue, Hui; Khawaja, H.

    2017-01-01

    This paper presents an analytical study of sandwich structures. In this study, the Euler-Bernoulli beam equation is solved analytically for a four-point bending problem. Appropriate initial and boundary conditions are specified to enclose the problem. In addition, the balance coefficient is calculated and the Rule of Mixtures is applied. The focus of this study is to determine the effective material properties and geometric features such as the moment of inertia of a sandwich beam. The effective parameters help in the development of a generic analytical correlation for complex sandwich structures from the perspective of four-point bending calculations. The main outcomes of these analytical calculations are the lateral displacements and longitudinal stresses for each particular material in the sandwich structure.

  18. Interfacial Crack Arrest in Sandwich Panels with Embedded Crack Stoppers Subjected to Fatigue Loading

    Science.gov (United States)

    Martakos, G.; Andreasen, J. H.; Berggreen, C.; Thomsen, O. T.

    2017-02-01

    A novel crack arresting device has been implemented in sandwich panels and tested using a special rig to apply out-of-plane loading on the sandwich panel face-sheets. Fatigue crack propagation was induced in the face-core interface of the sandwich panels which met the crack arrester. The effect of the embedded crack arresters was evaluated in terms of the achieved enhancement of the damage tolerance of the tested sandwich panels. A finite element (FE) model of the experimental setup was used for predicting propagation rates and direction of the crack growth. The FE simulation was based on the adoption of linear fracture mechanics and a fatigue propagation law (i.e. Paris law) to predict the residual fatigue life-time and behaviour of the test specimens. Finally, a comparison between the experimental results and the numerical simulations was made to validate the numerical predictions as well as the overall performance of the crack arresters.

  19. Templating odd numbered magnetic rings: oxovanadium heptagons sandwiched by beta-cyclodextrins.

    Science.gov (United States)

    Hoshino, Norihisa; Nakano, Motohiro; Nojiri, Hiroyuki; Wernsdorfer, Wolfgang; Oshio, Hiroki

    2009-10-28

    The oxovanadium heptagons sandwiched by beta-cyclodextrins showed stepped magnetization curves, which were characteristic of level crossings of spin sublevels. Doubly degenerate ground Kramers' doublets split into two spin states, and the splitting energy gaps depend upon ring distortions.

  20. The Influence of Face Sheet Wrinkle Defects on the Performance of FRP Sandwich Structures

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Carl Christian; Pettersson, Robert

    2005-01-01

    Wrinkle defects may reduce the compressive strength of a face laminate for inplane loading applied perpendicularly to the line of the wrinkle. To be able to decide whether a repair is needed it is necessary to know the magnitude of the strength reduction for a given wrinkle geometry. In the studies...... reported here, the influence of wrinkle defects on the in-plane compressive strength of quasiisotropic CFRP laminates used in PVC foam-cored sandwich panels has been investigated by three approaches: testing of sandwich beam specimens in fourpoint bending, testing of sandwich panels with in......-plane compression, and finite element simulation. Wrinkles involving different numbers of plies have been considered. Two different sandwich lay-ups typical of deck and hull bottom panels in a naval ship have been included....

  1. The Effect of Face Sheet Wrinkle Defects on the Strength of FRP Sandwich Structures

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Christian; Pettersson, Robert

    2007-01-01

    Wrinkle defects may reduce the compressive strength of a face laminate for in-plane loading applied perpendicularly to the line of the wrinkle. To be able to decide whether a repair is needed, it is necessary to know the magnitude of the strength reduction for a given wrinkle geometry....... In the studies reported here, the influence of wrinkle defects on the in-plane compressive strength of quasi-isotropic carbon fiber reinforced plastic (CFRP) laminates used in PVC foam-cored sandwich panels has been investigated by three approaches: testing of sandwich beam specimens in four-point bending......, testing of sandwich panels with inplane compression, and finite element simulation. Wrinkles involving different numbers of plies have been considered. Two different sandwich lay-ups typical of deck and hull bottom panels in naval ships have been included....

  2. Vibroacoustic optimization of anti-tetrachiral and auxetic hexagonal sandwich panels with gradient geometry

    Science.gov (United States)

    Ranjbar, Mostafa; Boldrin, Luca; Scarpa, Fabrizio; Neild, Simon; Patsias, Sophoclis

    2016-05-01

    The work describes the vibroacoustic behavior of anti-tetrachiral and auxetic hexagonal gradient sandwich panels using homogenized finite element models to determine the mechanical properties of the auxetic structures, the natural frequencies and radiated sound power level of sandwich panels made by the auxetic cores. The mechanical properties and the vibroacoustic behavior of auxetic hexagonal sandwich panels are investigated as a benchmark. The radiated sound power level of the structure over the frequency range of 0-1000 Hz is minimized by modifying the core geometry of the gradient auxetic sandwich panels. Several excitation cases are considered. First-order and random optimization methods are used for the minimization of radiated sound power level of the structures. The results of this study present significant insights into the design of auxetic structures with respect to their vibroacoustical properties.

  3. Experimental and Theoretical Deflections of Hybrid Composite Sandwich Panel under Four-point Bending Load

    Directory of Open Access Journals (Sweden)

    Jauhar Fajrin

    2017-03-01

    Full Text Available This paper presents a comparison of theoretical and experimental deflection of a hybrid sandwich panel under four-point bending load. The paper initially presents few basic equations developed under three-point load, followed by development of model under four-point bending load and a comparative analysis between theoretical and experimental results. It was found that the proposed model for predicting the deflection of hybrid sandwich panels provided fair agreement with the experimental values. Most of the sandwich panels showed theoretical deflection values higher than the experimental values, which is desirable in the design. It was also noticed that the introduction of intermediate layer does not contribute much to reduce the deflection of sandwich panel as the main contributor for the total deflection was the shear deformation of the core that mostly determined by the geometric of the samples and the thickness of the core.

  4. Flutter Characteristic Study of Composite Sandwich Panel with Functionally Graded Foam Core

    Directory of Open Access Journals (Sweden)

    Peng Jin

    2016-01-01

    Full Text Available This paper attempts to investigate the flutter characteristic of sandwich panel composed of laminated facesheets and a functionally graded foam core. The macroscopic properties of the foam core change continuously along this direction parallel to the facesheet lamina. The model used in the study is a simple sandwich panel-wing clamped at the root, with three simple types of grading strategies for FGM core: (1 linear grading strategy in the chord-wise direction, (2 linear grading strategy in the span-wise direction, and (3 bilinear grading of properties of foam core across the panel. The results show that use of FGM core has the potential to increase the flutter speed of the sandwich panel. Finally, a minimum weight design of composite sandwich panel with lamination parameters of facesheet and density distribution of foam core as design variables is conducted using particle swarm optimization (PSO.

  5. Two dimensional dynamic analysis of sandwich plates with gradient foam cores

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Lin; Xiao, Deng Bao; Zhao, Guiping [State Key Laboratory for Mechanical structure Strength and Vibration, School of AerospaceXi' an Jiaotong University, Xi' an (China); Cho, Chong Du [Dept. of Mechanical Engineering, Inha University, Inchon (Korea, Republic of)

    2016-09-15

    Present investigation is concerned about dynamic response of composite sandwich plates with the functionally gradient foam cores under time-dependent impulse. The analysis is based on a model of the gradient sandwich plate, in which the face sheets and the core adopt the Kirchhoff theory and a [2, 1]-order theory, respectively. The material properties of the gradient foam core vary continuously along the thickness direction. The gradient plate model is validated with the finite element code ABAQUS®. And the results show that the proposed model can predict well the free vibration of composite sandwich plates with gradient foam cores. The influences of gradient foam cores on the natural frequency, deflection and energy absorbing of the sandwich plates are also investigated.

  6. An Investigation on Low Velocity Impact Response of Multilayer Sandwich Composite Structures

    Directory of Open Access Journals (Sweden)

    S. Jedari Salami

    2013-01-01

    Full Text Available The effects of adding an extra layer within a sandwich panel and two different core types in top and bottom cores on low velocity impact loadings are studied experimentally in this paper. The panel includes polymer composite laminated sheets for faces and the internal laminated sheet called extra layer sheet, and two types of crushable foams are selected as the core material. Low velocity impact tests were carried out by drop hammer testing machine to the clamped multilayer sandwich panels with expanded polypropylene (EPP and polyurethane rigid (PUR in the top and bottom cores. Local displacement of the top core, contact force and deflection of the sandwich panel were obtained for different locations of the internal sheet; meanwhile the EPP and PUR were used in the top and bottom cores alternatively. It was found that the core material type has made significant role in improving the sandwich panel’s behavior compared with the effect of extra layer location.

  7. Detecting and identifying damage in sandwich polymer composite by using acoustic emission

    DEFF Research Database (Denmark)

    McGugan, M.; Sørensen, Bent F.; Østergaard, R.

    2006-01-01

    Acoustic emission is a useful monitoring tool for extracting extra information during mechanical testing of polymer composite sandwich materials. The study of fracture mechanics within test specimens extracted from wind turbine blade material ispresented. The contribution of the acoustic emission...

  8. Stress Distribution on Sandwich Structure with Triangular Grid Cores Suffered from Bending Load

    Directory of Open Access Journals (Sweden)

    Cui Xu

    2015-01-01

    Full Text Available Triangular grid reinforced by carbon fiber/epoxy (CF/EP was designed and manufactured. The sandwich structure was prepared by gluing the core and composite skins. The mechanical properties of the sandwich structure were investigated by the finite element analysis (FEA and three-point bending methods. The calculated bending stiffness and core shear stress were compared to the characteristics of a honeycomb sandwich structure. The results indicated that the triangular core ultimately failed under a bending load of 11000 N; the principal stress concentration was located at the loading region; and the cracks occurred on the interface top skin and triangular core. In addition, the ultimate stress bearing of the sandwich structure was 8828 N. The experimental results showed that the carbon fiber reinforced triangular grid was much stiffer and stronger than the honeycomb structure.

  9. Investigation of out of plane compressive strength of 3D printed sandwich composites

    Science.gov (United States)

    Dikshit, V.; Yap, Y. L.; Goh, G. D.; Yang, H.; Lim, J. C.; Qi, X.; Yeong, W. Y.; Wei, J.

    2016-07-01

    In this study, the 3D printing technique was utilized to manufacture the sandwich composites. Composite filament fabrication based 3D printer was used to print the face-sheet, and inkjet 3D printer was used to print the sandwich core structure. This work aims to study the compressive failure of the sandwich structure manufactured by using these two manufacturing techniques. Two different types of core structures were investigated with the same type of face-sheet configuration. The core structures were printed using photopolymer, while the face-sheet was made using nylon/glass. The out-of-plane compressive strength of the 3D printed sandwich composite structure has been examined in accordance with ASTM standards C365/C365-M and presented in this paper.

  10. Effect of varying geometrical parameters of trapezoidal corrugated-core sandwich structure

    Directory of Open Access Journals (Sweden)

    Zaid N.Z.M.

    2017-01-01

    Full Text Available Sandwich structure is an attractive alternative that increasingly used in the transportation and aerospace industry. Corrugated-core with trapezoidal shape allows enhancing the damage resistance to the sandwich structure, but on the other hand, it changes the structural response of the sandwich structure. The aim of this paper is to study the effect of varying geometrical parameters of trapezoidal corrugated-core sandwich structure under compression loading. The corrugated-core specimen was fabricated using press technique, following the shape of trapezoidal shape. Two different materials were used in the study, glass fibre reinforced plastic (GFRP and carbon fibre reinforced plastic (CFRP. The result shows that the mechanical properties of the core in compression loading are sensitive to the variation of a number of unit cells and the core thickness.

  11. Magnetic and Structural Properties in Co/Cu/Co Sandwiches with Ni and Cr Buffer Layers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The magnetic and structural properties in Co/Cu/Co sandwiches with Ni and Cr buffer layers were investigated. It was found that the coercivity in Ni layer buffered samples decreases with increasing Ni layer thickness, while that in Cr layer buffered ones increases with increasing Cr layer thickness, leading to a large difference in field sensitivity of their giant magnetoresistance (GMR) properties. X-ray diffraction and high resolution transmission electron microscope images exhibited that there is a strong fcc (111) texture in the samples with Ni buffer layer. But there are only randomly oriented polycrystalline grains in Cr buffered sandwiches. According to atomic force microscope topography, the surface roughness of Cr buffered sandwiches is smaller than that of Ni buffered ones. It is demonstrated that buffer layer influences both magnetic and structural properties in Co/Cu/Co sandwiches as well as their GMR characteristics.

  12. Interfacial Crack Arrest in Sandwich Panels with Embedded Crack Stoppers Subjected to Fatigue Loading

    Science.gov (United States)

    Martakos, G.; Andreasen, J. H.; Berggreen, C.; Thomsen, O. T.

    2016-08-01

    A novel crack arresting device has been implemented in sandwich panels and tested using a special rig to apply out-of-plane loading on the sandwich panel face-sheets. Fatigue crack propagation was induced in the face-core interface of the sandwich panels which met the crack arrester. The effect of the embedded crack arresters was evaluated in terms of the achieved enhancement of the damage tolerance of the tested sandwich panels. A finite element (FE) model of the experimental setup was used for predicting propagation rates and direction of the crack growth. The FE simulation was based on the adoption of linear fracture mechanics and a fatigue propagation law (i.e. Paris law) to predict the residual fatigue life-time and behaviour of the test specimens. Finally, a comparison between the experimental results and the numerical simulations was made to validate the numerical predictions as well as the overall performance of the crack arresters.

  13. Wave propagation and absorption of sandwich beams containing interior dissipative multi-resonators.

    Science.gov (United States)

    Chen, H; Li, X P; Chen, Y Y; Huang, G L

    2017-04-01

    In this study, a sandwich beam with periodic multiple dissipative resonators in the sandwich core material is investigated for broadband wave mitigation and/or absorption. An analytical approach based on the transfer matrix method and Bloch theorem is developed for both infinite and finite sandwich structures. Wave attenuation constants are theoretically obtained to examine the effects of various system parameters on the position, width and wave attenuation performance of the band gaps. The wave absorption coefficient of the sandwich beam is quantitatively studied to distinguish wave attenuation mechanisms caused by reflection and absorption. It is numerically demonstrated that a transient blast-induced elastic wave with broadband frequencies can be almost completely mitigated or absorbed at a subwavelength scale. The results of this study could be used for developing new multifunctional composite materials to suppress impact-induced and/or blast-induced elastic waves which may cause severe local damage to engineering structures.

  14. Sandwich-type theorems for a class of integral operators with special properties

    Directory of Open Access Journals (Sweden)

    Parisa Hariri

    2014-02-01

    Full Text Available In the present paper, we prove subordination, superordination and sandwich-type properties of a certain integral operators for univalent functions on open unit disc, moreover the special behavior of this class is investigated.

  15. Effects of Core Softness and Bimodularity of Fibreglass Layers on Flexural Stiffness of Polymer Sandwich Structures

    Directory of Open Access Journals (Sweden)

    Šuba Oldřich

    2017-01-01

    Full Text Available This paper deals with the study of the flexural stiffness of the sandwich structures based on fibreglass and polymeric foams. The influence of geometrical and material parameters on the resulting effective flexural stiffness of the sandwich structure is being studied experimentally, analytically and by using FEM models. The effective modulus of elasticity of the sandwich-structured element is being studied and its theoretical and model dependencies on the flexibility of the foam core and bimodularity of the fibreglass layers are being investigated. The achieved results are compared with the experimentally observed values. This study shows that it is necessary to pay special attention to the issue of flexural stiffness of the walls when designing sandwich shell products in order to prevent possible failures in the practical applications of these types of structures.

  16. Prediction of Thermal and Elastic Properties of Honeycomb Sandwich Plate for Analysis of Thermal Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seok Min; Lee, Jang Il; Byun, Jae Ki; Choi, Young Don [Korea Univ., Seoul (Korea, Republic of)

    2014-04-15

    Thermal problems that are directly related to the lifetime of an electronic device are becoming increasingly important owing to the miniaturization of electronic devices. To solve thermal problems, it is essential to study thermal stability through thermal diffusion and insulation. A honeycomb sandwich plate has anisotropic thermal conductivity. To analyze the thermal deformation and temperature distribution of a system that employs a honeycomb sandwich plate, the thermal and elastic properties need to be determined. In this study, the thermal and elastic properties of a honeycomb sandwich plate, such as thermal conductivity, coefficient of thermal expansion, elastic modulus, Poisson's ratio, and shear modulus, are predicted. The properties of a honeycomb sandwich plate vary according to the hexagon size, thickness, and material properties.

  17. Fracture Testing of Honeycomb Core Sandwich Composites Using the DCB-UBM Test

    DEFF Research Database (Denmark)

    Saseendran, Vishnu; Berggreen, Christian; Carlsson, Leif A.

    2015-01-01

    of the face/core interface. In this paper, a novel test-rig exploiting the double cantilever beam-uneven bending moments (DCB-UBM) concept is used to determine the fracture toughness of aircraft type honeycomb core sandwich composites as a function of the phase angle (mode-mixity), within the framework......Face/core debonds in sandwich structures cause loss of integrity of sandwich structures. The debond problem in honeycomb core sandwich composites has not been widely studied. A suitable fracture approach coupled with experimental validation is paramount to determine the fracture resistance...... of Linear Elastic Fracture Mechanics (LEFM). The Double Cantilever Beam subjected to Uneven Bending Moments (DCB-UBM) test set-up, which was introduced by Sørensen.et.al [1], circumvents any dependency of the pre-crack length in calculation of Gc. The new test setup is based on rotary actuators which...

  18. Mid term results of total hip arthroplasty using polyethylene-ceramic composite (Sandwich liner

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2016-01-01

    Conclusions: Our experience with the ceramic-polyethylene sandwich liner acetabular component has been disappointing because of the high rate of fracture and osteolyis. We have discontinued the use of this device and recommend the same.

  19. Penetration of sandwich plates with hybrid-cores under oblique ballistic impact

    Directory of Open Access Journals (Sweden)

    Changye Ni

    2014-01-01

    Full Text Available The oblique penetration performance of lightweight hybrid-cored sandwich plates are investigated numerically. To compose the hybrid-core, ceramic prisms are inserted into pyramidal metal lattice trusses and fixed using epoxy resin. Three-dimensional finite element simulations are carried out for the hybridcored sandwich impacted at 15°, 30°, 45°, and 60° obliquity by a hemispherical projectile. The ballistic limit, the energy absorbed by the constituting elements, and the critical oblique angle are quantified. The physical mechanisms underlying the failure and the influence of fundamental system parameters are explored. The angle of obliquity is found to have significant influence on the ballistic trajectory and erosion of the projectile, thus it is important for the impact response and penetration resistance of the sandwich. For oblique angles equal to or larger than 45°, the projectile moves mainly horizontally and can not effectively penetrate across the sandwich.

  20. Detection of Penicillinase in Milk by Sandwich ELISA Based Polyclonal and Monoclonal Antibody.

    Science.gov (United States)

    Zhao, Yinli; Li, Guoxi

    2016-01-01

    A sandwich ELISA has been developed using polyclonal and monoclonal antibody for the determination of penicillinase in milk. For this purpose, specific polyclonal and monoclonal antibodies against penicillinase were generated and characterized. Using penicillinase standards prepared from 1-128 ng/mL, the method indicated that the detection limit of the sandwich ELISA, as measured in an ELISA plate reader, was as low as 0.86 ng/mL of penicillinase. For determine the accuracy, raw milk containing 2, 8, 32, and 64 ng/mL of penicillinase were tested by sandwich ELISA. Recoveries were from 93-97.5%, and the coefficient of variation [CV (%)] were from 5.55-8.38%. For interassay reproducibility, recoveries were from 89.5-95.1%, the coefficient of variation [CV (%)] were from 5.26-9.58%. This sandwich ELISA provides a useful screening method for quantitative detection of penicillinase in milk.

  1. Generation of mAbs to foot-and-mouth disease virus serotype A and application in a competitive ELISA for serodiagnosis.

    Science.gov (United States)

    Yang, Ming; Xu, Wanhong; Bittner, Hilary; Horsington, Jacquelyn; Vosloo, Wilna; Goolia, Melissa; Lusansky, Diana; Nfon, Charles

    2016-11-28

    Foot-and-mouth disease (FMD) is an economically devastating disease that severely limits international trade of animals. Of the seven FMD virus (FMDV) serotypes, serotype A is one of the most widespread cross the world. Currently antibodies to FMDV are detected in animals using the virus neutralization test (VNT) and the enzyme-linked immunosorbent assay (ELISA). The VNT is laborious, time-consuming and reliant on live virus and cell cultures, while ELISA has the advantage of using inactivated antigens and often provides more reproducible results. The aim of this study was to develop a reliable and rapid competitive ELISA (cELISA) for the detection of antibodies to FMDV serotype A (FMDV/A). A panel of FMDV/A specific monoclonal antibodies (mAbs) was generated and their ability to compete with a polyclonal serum from FMDV/A-infected cattle was examined. Two mAbs inhibited the binding of a polyclonal serum to FMDV/A viruses. The binding epitopes of each were determined as conformational and located on the VP2 viral capsid protein. The FMDV/A cELISA was developed using these two mAbs and FMDV/A inactivated virus as antigen. The diagnostic specificity and sensitivity were 99.7 and 99.3% (98.5-100%) respectively, based on a predetermined cut-off of 50% inhibition. When analysing sera from animals experimentally infected with FMDV/A, the cELISA detected antibodies from 5-days post infection (dpi) and remained positive for at least 21-28 days post infection. Comparison based on the Kappa coefficient showed strong agreement (90-94%) between cELISA and VNT. The cELISA results are comparable to the VNT for antibody detection making it a simple and reliable test to detect antibodies against FMDV/A.

  2. [Comparison of the antigenic spectrum A1, A2, and Ax erythrocytes: inhibition of mab with glucoconjugates of lipid and protein nature with different isoelectric properties].

    Science.gov (United States)

    Delevskiĭ, Iu P; Zinchenko, A A

    2007-12-01

    The inhibition of monoclonal antibodies (MAbs) (anti-A1 2-24, anti-A 2-22, anti- 2-19, and anti- A 2-18; Workshop IV) by glycotopes (glycoconjugates) obtained by the enzymatic treatment of A1, A2, and Ax erythrocytes and by chloroform-methanol method from the membranes of these erythrocytes, followed by ion-exchange gel chromatography was evaluated. According to specificity and isoelectric properties, glycoconjugates (in the sequence of desorption from an anion exchanger) of glycoprotein (A(pr-00), A(pr-0), A(pr-1), A(pr-3)) and glycosphingolipid (A1p,00, A(1p-0), A(1p-1), A(1p-3), A(1p-3)) origin were identified. A1 erythrocytes showed the broad-spectrum inhibiting activity of glycoconjugates, which being at maximum with acid A(1p-00) and A(pr-3) (the ionic points of pH 6.55 and 6.45), as well as with A(lp-00) and A(1p-00) 1 The inhibition of A(pr-3) from A2 was significantly weaker that that from A1. An A(pr-3) fraction from Ax erythrocytes inhibited as strongly as in A1 and A2. The inhibition of A(pr-3p) from Ax either failed to develop at all (MAb 2-19) or turned out be weakened (MAbs 2-22 and 2-18). Thus, the cascade decrease in agglutinogenicity in the order of A1, A2, and Ax correlated with the reduction in the inhibiting capacity of A(pr-3) in all the study groups, including Ax.

  3. Aeroallergen analyses and their clinical relevance. I. Immunochemical quantification of allergens by RAST-inhibition, Mab-ELISA, basophil histamine release, and counter current immuno electrophoresis

    DEFF Research Database (Denmark)

    Johnsen, C R; Abrahamsen, L; Stahl Skov, P;

    1991-01-01

    The aim was to compare IgE and IgG4 RAST-inhibition assay (RI), monoclonal antibody ELISA (Mab-ELISA), counter current immuno electrophoresis (CCIE) and histamine release from basophil leukocytes (HR) for allergen quantification with special reference to aeroallergen detection. As components...... and Derm. pter. (10-10(2) SQ-U/ml), and 10(2)-10(3) SQ-U/ML for dog. Because of cross-reactivity, a minor degree of interference was observed in the IgE-RI and the HR test for the highest concentration of cat and dog allergens....

  4. Study on folds of monolayer sandwiched-in different thickness terranes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The paper discussed the limitation of ‘Dominant wavelength theory’. The theoretical model and nonhomogeneous differential equation of fold and deformation of a monolayer sandwiched-in limited and different thickness terranes are proposed by using mechanics of elasticity. In addition, the ′Dominant wavelength theory’ is proved by the experimental folding in elastic materials. The folds of a monolayer sandwiched-in limited and different thickness terranes are studied inside and are explored in the field.

  5. The primitive matrices of sandwich semigroups of generalized circulant Boolean matrices

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-ping; CHEN Jin-song

    2013-01-01

    Let Gn(C) be the sandwich semigroup of generalized circulant Boolean matrices with the sandwich matrix C and GC (Jn) the set of all primitive matrices in Gn(C). In this paper, some necessary and suffi cient conditions for A in the semigroup Gn(C) to be primitive are given. We also show that GC (Jn) is a subsemigroup of Gn(C).

  6. Geometrical parameters influence on behavior of the sandwich plates with corrugated core

    Directory of Open Access Journals (Sweden)

    Djoković Jelena M.

    2016-01-01

    Full Text Available The influence of geometric parameters on behavior and stiffness of sandwich plates with corrugated core is considered in this paper. The following parameters were analyzed: ratio of core sheet and facing sheet thickness and the ratio of the core’s pitch to the core’s depth, as well as the corrugation angle. It is shown that changes of these parameters can contribute to increase or decrease of the corrugated sandwich plate stiffness.

  7. Assessment of foam fracture in sandwich beams using thermoelastic stress analysis

    DEFF Research Database (Denmark)

    Dulieu-Barton, J.M.; Berggreen, Christian; Mettemberg, C.

    2009-01-01

    Thermoelastic Stress Analysis (TSA) has been well established for determining crack-tip parameters in metallic materials. This paper examines its ability to determine accurately the crack-tip parameters for PVC foam used in sandwich structures.......Thermoelastic Stress Analysis (TSA) has been well established for determining crack-tip parameters in metallic materials. This paper examines its ability to determine accurately the crack-tip parameters for PVC foam used in sandwich structures....

  8. Polyisocyanurate systems for insulating and sandwich elements; Polyisocyanurat-Systeme fuer Daemm- und Sandwichelemente

    Energy Technology Data Exchange (ETDEWEB)

    Malotki, P. von [Elastogran GmbH, Lemfoerde (Germany)

    2000-07-01

    PUR rigid foam plates are laminated with flexible Al films, paper or glass non-wovens, or may be processed into sandwich elements with metallic top-layers via coil-coating. Dependence of heat insulation efficiency, dimensional stability and fire behavior of the foam on chemical composition and the blowing agents is considered and compared with polyisocyanurate foams. Recipes for the production of PIR heat insulation elements and sandwich elements are given.

  9. Multiscale Modeling Methods for Analysis of Failure Modes in Foldcore Sandwich Panels

    Science.gov (United States)

    Sturm, R.; Schatrow, P.; Klett, Y.

    2015-12-01

    The paper presents an homogenised core model suitable for use in the analysis of fuselage sandwich panels with folded composite cores under combined loading conditions. Within a multiscale numerical design process a failure criterion was derived for describing the macroscopic behaviour of folded cores under combined loading using a detailed foldcore micromodel. The multiscale modelling method was validated by simulation of combined compression/bending failure of foldcore sandwich panels.

  10. EXPERIMENTAL ANALYSIS OF FLEXURAL STRENGTH ON GLASS FIBER SANDWICH COMPOSITE BY VARYING Z-PINS PITCHES

    OpenAIRE

    Pravin*, Jeyapratha

    2016-01-01

    This paper ambit to evaluate the flexural strength of glass fiber sandwich panels with varying z-pins pitches. Failure of sandwich panel are delamination and core shear, to minimize the crack propagation, pins are inserted in z-direction, by varying pitches through its thickness. During the insertion of pin, may cause the material some damage. Despite the damage, flexural property does not affected due interpolation of pins. Although the experiment were pull out with a phenomenal results of z...

  11. Mechanical behavior of a sandwich with corrugated GRP core: numerical modeling and experimental validation

    OpenAIRE

    Tumino, D; T. Ingrassia; V. Nigrelli; G. Pitarresi; V. Urso Miano

    2014-01-01

    In this work the mechanical behaviour of a core reinforced composite sandwich structure is studied. The sandwich employs a Glass Reinforced Polymer (GRP) orthotropic material for both the two external skins and the inner core web. In particular, the core is designed in order to cooperate with the GRP skins in membrane and flexural properties by means of the addition of a corrugated laminate into the foam core. An analytical model has been developed to replace a unit cell of this s...

  12. Analysis and Testing of a Tapered End Connection for Laser Welded Steel Sandwich Panels

    Science.gov (United States)

    2009-08-15

    1951, Elastic Constants for Corrugated Core Sandwich Plates. Technical Note 2289. National Aeronautics and Space Administration ( NASA ). 19. Lok...Assoc. Professor of Mechanical Engineering, University of Maine (Co-I) Grant No: N00014-05-1 -0735 ATS subcontract No: UM-591 Report No. C-2004-015...RPT-04 August 15,2009 20090925154 ABSTRACT This report summarize the analysis and cyclic testing of a laser welded steel sandwich panel end

  13. Structural performance of complex core systems for FRP-balsa composite sandwich bridge decks

    OpenAIRE

    Osei-Antwi, Michael

    2014-01-01

    Based on current fiber-reinforced polymer (FRP) composite construction principles, FRP decks fall into two categories: pultruded decks and sandwich decks. Sandwich decks comprise face sheets and either honeycombs or foams reinforced with internal FRP webs for shear resistance. The honeycomb structure and the webs cause debonding between the upper face sheets and the core due to the uneven support of the former. An alternative material that has high shear capacity and can provide uniform ...

  14. Numerical analysis of sandwich beam with corrugated core under three-point bending

    Energy Technology Data Exchange (ETDEWEB)

    Wittenbeck, Leszek [Poznan University of Technology, Institute of Mathematics Piotrowo Street No. 5, 60-965 Poznan (Poland); Grygorowicz, Magdalena; Paczos, Piotr [Poznan University of Technology, Institute of Applied Mechanics Jana Pawla IIStreet No. 24, 60-965 Poznan (Poland)

    2015-03-10

    The strength problem of sandwich beam with corrugated core under three-point bending is presented.The beam are made of steel and formed by three mutually orthogonal corrugated layers. The finite element analysis (FEA) of the sandwich beam is performed with the use of the FEM system - ABAQUS. The relationship between the applied load and deflection in three-point bending is considered.

  15. Influence of weld stiffness on buckling strength of laser-welded web-core sandwich plates

    OpenAIRE

    Jelovica, Jasmin; Romanoff, Jani; Ehlers, Sören; Varsta, Petri

    2012-01-01

    This paper investigates the influence of weld rotation stiffness on the global bifurcation buckling strength of laser-welded web-core sandwich plates. The study is carried out using two methods, the first is the equivalent single-layer theory approach solved analytically for simply supported plates and numerically for clamped plates. First-order shear deformation theory is used. The second method is the three-dimensional model of a sandwich plate solved with finite element method. Both approa...

  16. Sandwiched zinc-finger nucleases demonstrating higher homologous recombination rates than conventional zinc-finger nucleases in mammalian cells.

    Science.gov (United States)

    Mori, Tomoaki; Mori, Koichi; Tobimatsu, Takamasa; Sera, Takashi

    2014-02-01

    We previously reported that our sandwiched zinc-finger nucleases (ZFNs), in which a DNA cleavage domain is inserted between two artificial zinc-finger proteins, cleave their target DNA much more efficiently than conventional ZFNs in vitro. In the present study, we compared DNA cleaving efficiencies of a sandwiched ZFN with those of its corresponding conventional ZFN in mammalian cells. Using a plasmid-based single-strand annealing reporter assay in HEK293 cells, we confirmed that the sandwiched ZFN induced homologous recombination more efficiently than the conventional ZFN; reporter activation by the sandwiched ZFN was more than eight times that of the conventional one. Western blot analysis showed that the sandwiched ZFN was expressed less frequently than the conventional ZFN, indicating that the greater DNA-cleaving activity of the sandwiched ZFN was not due to higher expression of the sandwiched ZFN. Furthermore, an MTT assay demonstrated that the sandwiched ZFN did not have any significant cytotoxicity under the DNA-cleavage conditions. Thus, because our sandwiched ZFN cleaved more efficiently than its corresponding conventional ZFN in HEK293 cells as well as in vitro, sandwiched ZFNs are expected to serve as an effective molecular tool for genome editing in living cells.

  17. Parametric study on nonlinear vibration of composite truss core sandwich plate with internal resonance

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jia Nen; Liu, Jun [Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System, Tianjin University of Technology, Tianjin (China); Zhang, Wei; Yao, Ming Hui [College of Mechanical Engineering, Beijing University of Technology, Beijing (China); Sun, Min [School of Science, Tianjin Chengjian University, Tianjin (China)

    2016-09-15

    Nonlinear vibrations of carbon fiber reinforced composite sandwich plate with pyramidal truss core are investigated. The governing equation of motion for the sandwich plate is derived by using a Zig-Zag theory under consideration of geometrically nonlinear. The natural frequencies of sandwich plates with different dimensions are calculated and compared with those obtained from the classic laminated plate theory and Reddy's third-order shear deformation plate theory. The frequency responses and waveforms of the sandwich plate when 1:3 internal resonance occurs are obtained, and the characteristics of the internal resonance are discussed. The influences of layer number of face sheet, strut radius, core height and inclination angle on the nonlinear responses of the sandwich plate are analyzed. The results demonstrate that the strut radius and inclination angle mainly affect the resonance frequency band of the sandwich plate, and the layer number and core height not only influence the resonance frequency band but also significantly affect the response amplitude.

  18. An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

    Science.gov (United States)

    Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

    2006-01-01

    Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

  19. Development of a finite element model for the simulation of parabolic impact of sandwich panels

    Science.gov (United States)

    Ram Ramakrishnan, Karthik; Guérard, Sandra; Mahéo, Laurent; Shankar, Krishna; Viot, Philippe

    2015-09-01

    Sandwich panels are lightweight structures of two thin high strength facesheets bonded to either side of a thick low density core such as foams and honeycombs. It is necessary to study the impact response of sandwich structures in order to ensure the reliability and safety of these structures. The response of sandwich panels to impact loading is usually studied for impact at normal angle of incidence. In real engineering situations, the structures are more frequently loaded at some oblique angle or with a complex trajectory. It is easy to carry out normal impact tests using devices like the drop tower, but impacts at oblique angles are difficult to characterise experimentally. A tri-dimensional impact device called Hexapod has been developed to experimentally study the impact loading of sandwich plates with a parabolic trajectory. The Hexapod is a modified Gough-Stewart platform that can be moved independently in the six degrees of freedom, corresponding to three translation axes and three rotation axes. In this paper, an approach for modelling the parabolic impact of sandwich structures with thin metallic facesheets and polymer foam core using commercial finite element code LS-DYNA software is presented. The results of the FE model of sandwich panels are compared with experimental data in terms of the time history of vertical and horizontal components of force. A comparison of the strain history obtained from Digital Image Correlation and LS-Dyna model are also presented.

  20. Mechanical properties of sandwich composite made of syntactic foam core and GFRP skins

    Directory of Open Access Journals (Sweden)

    Zulzamri Salleh

    2016-12-01

    Full Text Available Sandwich composites or sandwich panels have been widely used as potential materials or building structures and are regarded as a lightweight material for marine applications. In particular, the mechanical properties, such as the compressive, tensile and flexural behaviour, of sandwich composites formed from glass fibre sheets used as the skin and glass microballoon/vinyl ester as the syntactic foam core were investigated in this report. This syntactic foam core is sandwiched between unidirectional glass fibre reinforced plastic (GFRP using vinyl ester resins to build high performance sandwich panels. The results show that the compressive and tensile strengths decrease when the glass microballoon content is increased in syntactic foam core of sandwich panels. Moreover, compressive modulus is also found to be decreased, and there is no trend for tensile modulus. Meanwhile, the flexural stiffness and effective flexural stiffness for edgewise position have a higher bending as 50% and 60%, respectively. Furthermore, the results indicated that the glass microballoon mixed in a vinyl ester should be controlled to obtain a good combination of the tensile, compressive and flexural strength properties.

  1. Mechanical properties characterization of composite sandwich materials intended for space antenna applications

    Science.gov (United States)

    Bowles, Kenneth J.; Vannucci, Raymond D.

    1986-01-01

    The composite materials proposed for use in the Advanced Communications Technology Satellite (ACTS) Program contains a new, high modulus graphite fiber as the reinforcement. A study was conducted to measure certain mechanical properties of the new fiber-reinforced material as well as of a composite-faced aluminum honeycomb sandwich structure. Properties were measured at -157, 22, and 121 C. Complete characterization of this material was not intended. Longitudinal tensile, picture-frame shear, short-beam shear, and flexural tests were performed on specimens of the composite face-sheet materials. Unidirectional, cross-plied, and quasi-isotropic fiber composite ply layup designs were fabricated and tested. These designs had been studied by using NASA's Integrated Composite Analyzer (ICAN) computer program. Flexural tests were conducted on (+/- 60/0 deg) sub s composite-faced sandwich structure material. Resistance strain gages were used to measure strains in the tensile, picture-frame, and sandwich flexural tests. The sandwich flexural strength was limited by the core strength at -157 and 22 C. The adhesive bond strength was the limiting factor at 121 C. Adhesive mechanical properties are reflected in sandwich structure flexural properties when the span-to-depth ratio is great enough to allow a significant shear effect on the load-deflection behavior of the sandwich beam. Most measured properties agreed satisfactorily with the properties predicted by ICAN.

  2. Evaluation and selection of indirect ELISA and sandwich ELISA kits for anti-HCV detection

    Directory of Open Access Journals (Sweden)

    LI Yongzhen

    2014-10-01

    Full Text Available ObjectiveTo compare the sensitivity and specificity between indirect enzyme-linked immunosorbent assay (ELISA and double-antibody sandwich ELISA kits produced in China and to select the best ELISA kit. MethodsSamples for evaluation included 60 serum plates and 40 serum samples positive or weakly positive for antibody to hepatitis C virus (anti-HCV which were confirmed by recombinant immunoblot assay. These samples were tested with a sandwich ELISA kit and three indirect ELISA kits, all of which were produced in China. Comparison between ELISA kits was made by paired chi-square test; comparison of false negative rate was made by R×C contingency table test. ResultsThe sensitivities of three indirect ELISA kits and a sandwich ELISA kit were 90.2%, 78.0%, 95.1%, and 97.6%, respectively, and the specificities were 78.1%, 72.6%, 94.1%, and 100%, respectively. The sandwich ELISA kit had a 4-8 times higher sensitivity than indirect ELISA kits. The R×C contingency table test revealed significant differences in false negative rate between ELISA kits and combinations of ELISA kits (χ2=29.898, P<0.05. ConclusionSandwich ELISA kit has higher sensitivity and specificity than indirect ELISA kits. Combined use of sandwich ELISA and indirect ELISA kits can significantly reduce the false negative rate and effectively prevent missed anti-HCV detection.

  3. Development of a finite element model for the simulation of parabolic impact of sandwich panels

    Directory of Open Access Journals (Sweden)

    Ramakrishnan Karthik Ram

    2015-01-01

    Full Text Available Sandwich panels are lightweight structures of two thin high strength facesheets bonded to either side of a thick low density core such as foams and honeycombs. It is necessary to study the impact response of sandwich structures in order to ensure the reliability and safety of these structures. The response of sandwich panels to impact loading is usually studied for impact at normal angle of incidence. In real engineering situations, the structures are more frequently loaded at some oblique angle or with a complex trajectory. It is easy to carry out normal impact tests using devices like the drop tower, but impacts at oblique angles are difficult to characterise experimentally. A tri-dimensional impact device called Hexapod has been developed to experimentally study the impact loading of sandwich plates with a parabolic trajectory. The Hexapod is a modified Gough-Stewart platform that can be moved independently in the six degrees of freedom, corresponding to three translation axes and three rotation axes. In this paper, an approach for modelling the parabolic impact of sandwich structures with thin metallic facesheets and polymer foam core using commercial finite element code LS-DYNA software is presented. The results of the FE model of sandwich panels are compared with experimental data in terms of the time history of vertical and horizontal components of force. A comparison of the strain history obtained from Digital Image Correlation and LS-Dyna model are also presented.

  4. Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations Under Flexure Loads

    Science.gov (United States)

    Nordendale, Nikolas A.; Goyal, Vinay K.; Lundgren, Eric C.; Patel, Dhruv N.; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth N.

    2015-01-01

    An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and face-sheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. A building block approach using fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a small strength reduction due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

  5. PENGGUNAAN SANDWICH PLATE SYSTEM (SPS PADA KONSTRUKSI INNER BOTTOM

    Directory of Open Access Journals (Sweden)

    Ahmad Baidowi

    2015-06-01

    Full Text Available Perkembangan teknologi yang semakin maju memberikan alternatif-alternatif dalam memperbaiki berbagai bentuk sistem, termasuk di dalamnya konstruksi struktur kapal. Latar belakang dari penelitian ini adalah pada permasalahan kebutuhan material ringan pada kapal, kecepatan proses produksi, penyederhanaan konstruksi dan biaya perawatan kapal yang rendah. Penggunaan material ringan Sandwich Plate System (SPS menjadi salah satu jawaban dari permasalahan-permasalahan tersebut, penggunaan SPS dapat menyederhanakan bentuk dari konstruksi kapal dengan menghilangkan penegar inner bottom longitudinal dan mampu mengurangi Light Weight Tonnase (LWT. Artikel ini membahas perbandingan pola distribusi tegangan dan deformasi pada konstruksi bottom yang menggunakan SPS dan baja AH36, selain dari itu juga mengetahui seberapa besar pengurangan LWT yang dihasilkan untuk meningkatkan Payload kapal. Analisa dilakukan dengan simulasi numerik berdasarkan FEM pada konstruksi inner bottom dengan pembebanan muatan. Dari hasil simulasi didapatkan besar tegangan maksimal untuk material baja AH36 sebesar 226 Mpa dengan menggunakan penegar, sedangkan konstuksi dengan material SPS tegangan maksimal yang dihasilkan sebesar 221 Mpa tanpa penggunaan penegar, dengan deformasi maksimal untuk AH36 dan SPS yaitu 77 mm yang terjadi pada bagian tengah blok konstruksi inner bottom. Dengan hilangnya penegar berat konstruksi berkurang sebesar 13,05% dari penggunaan material baja AH36 sehingga memberikan peningkatan payload sebesar 13,05%. Simulasi penelitian dilakukan pada kapal Bulk Carrier (BC.

  6. Piezoelectric performance of fluor polymer sandwiches with different void structures

    Science.gov (United States)

    Lou, Kexing; Zhang, Xiaoqing; Xia, Zhongfu

    2012-06-01

    Film sandwiches, consisting of two outer layers of fluoroethylenepropylene and one middle layer of patterned porous polytetrafluoroethylene, were prepared by patterning and fusion bonding. Contact charging was conducted to render the films piezoelectric. The critical voltage to trigger air breakdown in the inner voids in the fabricated films was investigated. The piezoelectric d 33 coefficients were measured employing the quasistatic method and dielectric resonance spectrum. The results show that the critical voltage for air breakdown in the inner voids is associated with the void microstructure of the films. For the films with patterning factors of 0%, 25% and 44%, the critical values are 300, 230 and 230 kV/cm, respectively. With an increase in the patterning factor, both the piezoelectric d 33 coefficients determined from the dielectric resonance spectra and those determined from quasistatic measurements increase, which might be due to a decrease in Young's modulus for the films. The nonlinearity of d 33 becomes increasingly obvious as the patterning factor increases.

  7. Sandwiched structural panel having a bi-directional core structure

    Science.gov (United States)

    Weddendorf, Bruce (Inventor)

    1995-01-01

    A structural panel assembly has a bi-directional core structure sandwiched between and secured to a pair of outer side wall members. The core structure is formed from first and second perpendicular series of elongated strip members having crenelated configurations. The strip members in the first series thereof are transversely interwoven with the strip members in the second series thereof in a manner such that crest portions of the strip members in the first series overlie and oppose trough portions of the strip members in the second series, and trough portions of the strip members in the first series underlie and oppose crest portions of the strip members in the second series. The crest portions of all of the strip members lie generally in a first plane and are secured to the inner side of one of the panel assembly outer side walls, and the trough portions of all of the strip members lie generally in a second plane and are secured to the inner side of the other panel assembly outer side wall.

  8. Efficient transport of droplet sandwiched between saw-tooth plates.

    Science.gov (United States)

    Wang, Liya; Wu, Hengan; Wang, Fengchao

    2016-01-15

    The transport of droplet sandwiched between smooth and saw-tooth plates was investigated using molecular dynamics method. The repeated opening and closing of the plates result in sequential stretching and squeezing of the droplet, which provide the driving force. The asymmetrical saw tooth obstructs the backward motion of the droplet, and gives rise to a net forward displacement of the droplet in every opening and closing cycle. This unidirectional motion facilitates the efficient droplet transport, which is referred to as the ratchet-like effect in this work. Our simulations also reveal that the influence of the surface wettability on the droplet transport is different for saw-tooth and smooth plates. Droplet transport efficiency exhibits monotonic decrease with the increase of the solid-liquid interactions for saw-tooth plates. While for smooth plates, unidirectional droplet movement was only observed for certain solid-liquid interactions. Taken together these simulation results and theoretical analysis, we demonstrate that hydrophobic saw-tooth plates can improve the transport efficiency significantly. These findings not only enhance our understanding of the droplet transport from atomistic scale, but also are beneficial to practical applications in designing of micro- and nano-fluidic systems.

  9. GAMBE: multipurpose sandwich detector for neutrons and photons

    Science.gov (United States)

    Ahmed, A.; Burdin, S.; Casse, G.; van Zalinge, H.; Powel, S.; Rees, J.; Smith, A.; Tsurin, I.

    2016-10-01

    Detectors made with semiconductors such as silicon can be efficiently used for detecting and imaging neutrons when coated with suitable materials. They detect the charged reaction products resulting from the interaction of thermal neutrons with materials with high capture cross section like 10B, 6Li, and 6LiF. This work describes the performance of a thermal neutron detector system, GAMBE, which is based on silicon sensors and a layer of neutron-sensitive material, such as a lithium fluoride film or a lithium-6 foil, in a sandwich configuration. This arrangement has a total detection efficiency of 4 +/- 2 %, 7 +/- 1 %, and12 +/- 1 % for 7 μm 6LiF film, 40 μm and 70 μm 6Li foil respectively. Also, it enhances the rejection of fake hits using a simple coincidence method. The coincidence that defines a true neutron hit is the simultaneous signal recorded by the two sensors facing the conversion layer (or foil). These coincidences provide a very good method for rejecting the spurious hits coming from gamma-rays, which are usually present in the neutron field under measurement. The GAMBE system yields a rejection factor at the level of 108 allowing very pure neutron detection in high gamma background conditions. However, the price to pay is a reduction of the detection efficiency of 1 +/- 1 % or 0:9 +/- 0:3 % for 7 μm 6LiF film and 40 μm 6Li foil respectively.

  10. Magnetic ordering in Fe/Co sandwiches on Cu(100).

    Science.gov (United States)

    Razee, S S A; Staunton, J B; Szunyogh, L

    2009-07-01

    We investigate magnetic correlations and local magnetic moments at finite temperatures of some Fe and Co multilayers on Cu(100) substrates, such as Co(m)Fe(n)Co(m)/Cu(100) and Fe(m)Co(n)Fe(m)/Cu(100). We use an ab initio mean-field theory of magnetic fluctuations for layered materials based on the first-principles local spin-density functional theory implemented through the screened Korringa-Kohn-Rostoker method. We find that the presence of Fe layers in the neighbourhood of a Co layer always leads to a reduction in the magnetic moment of the Co atoms, whereas that of the Fe atoms is enhanced. Of particular interest is the lack of local moment formation on the single fcc-Co layer sandwiched between two fcc-Fe layers. However, a Co layer completely immersed in a Cu environment remains ferromagnetic. The Curie temperature of the Co(m)Fe(n)Co(m)/Cu(100) system oscillates as the Fe layer thickness is increased whereas that of the Fe(m)Co(n)Fe(m)/Cu(100) system increases almost monotonically with Co layer thickness.

  11. Numerical investigation of blanking for metal polymer sandwich sheets

    Directory of Open Access Journals (Sweden)

    Gutknecht Florian

    2016-01-01

    Full Text Available Metal polymer sandwich sheets consist of materials with drastically different mechanical properties. Due to this fact and because of high local gradients in the cutting zone during the blanking process, traditional process strategies and empirical knowledge are difficult to apply. A finite-element simulation of the shear cutting process is used to predict the necessary force and the geometry of the cutting surface. A fully-coupled ductile damage model is used for the description of the material behaviour. This model considers the influence of shear and compression-dominated stress states on the initiation of damage. Experimental tensile and compression test data is used for the identification of material parameters. The results of the blanking simulation are compared with experimental data. Furthermore, the evolution of the stress state is analysed to gain understanding of the underlying physics. Finally this model enables the prediction of core compression and other quantities such as the acting stresses and corresponding triaxilities, which provide valuable information for the development of analytical models.

  12. UHPC SANDWICH STRUCTURES WITH COMPOSITE COATING UNDER COMPRESSIVE LOAD

    Directory of Open Access Journals (Sweden)

    Jan Markowski

    2016-12-01

    Full Text Available Ultra-high-performance concrete (UHPC sandwich structures with composite coating serve as multipurpose load-bearing elements. The UHPC’s extraordinary compressive strength is used in a multi-material construction element, while issues regarding the concrete’s brittle failure behaviour are properly addressed. A hollow section concrete core is covered by two steel tubes. The outer steel tube is wrapped in a composite material. By this design, UHPC is used in a material- and shape-optimised way with a low dead weight ratio[1] concerning the load-bearing capacity and stability[2]. The cross-section’s hollow shape optimises the construction’s buckling stability while saving self-weight. The composite coating on the column’s outside functions both as a layer increasing the construction’s durability and as a structural component increasing the the maximum and the residual load capacity. Investigations on the construction’s structural behaviour were performed.

  13. Characterizing Facesheet/Core Disbonding in Honeycomb Core Sandwich Structure

    Science.gov (United States)

    Rinker, Martin; Ratcliffe, James G.; Adams, Daniel O.; Krueger, Ronald

    2013-01-01

    Results are presented from an experimental investigation into facesheet core disbonding in carbon fiber reinforced plastic/Nomex honeycomb sandwich structures using a Single Cantilever Beam test. Specimens with three, six and twelve-ply facesheets were tested. Specimens with different honeycomb cores consisting of four different cell sizes were also tested, in addition to specimens with three different widths. Three different data reduction methods were employed for computing apparent fracture toughness values from the test data, namely an area method, a compliance calibration technique and a modified beam theory method. The compliance calibration and modified beam theory approaches yielded comparable apparent fracture toughness values, which were generally lower than those computed using the area method. Disbonding in the three-ply facesheet specimens took place at the facesheet/core interface and yielded the lowest apparent fracture toughness values. Disbonding in the six and twelve-ply facesheet specimens took place within the core, near to the facesheet/core interface. Specimen width was not found to have a significant effect on apparent fracture toughness. The amount of scatter in the apparent fracture toughness data was found to increase with honeycomb core cell size.

  14. Sandwich module prototype progress for space solar power

    Science.gov (United States)

    Jaffe, Paul; Hodkin, Jason; Harrington, Forest; Person, Clark; Nurnberger, Michael; Nguyen, Bang; LaCava, Susie; Scheiman, Dave; Stewart, Grant; Han, Andrew; Hettwer, Ethan; Rhoades, Daniel

    2014-02-01

    Space solar power (SSP) has been broadly defined as the collection of solar energy in space and its wireless transmission for use on earth. This approach potentially gives the benefit of provision of baseload power while avoiding the losses due to the day/night cycle and tropospheric effects that are associated with terrestrial solar power. Proponents have contended that the implementation of such systems could offer energy security, environmental, and technological advantages to those who would undertake their development. Among recent implementations commonly proposed for SSP, the modular symmetrical concentrator (MSC) and other modular concepts have received considerable attention. Each employs an array of modules for performing conversion of concentrated sunlight into microwaves or laser beams for transmission to earth. While prototypes of such modules have been designed and developed previously by several groups, none have been subjected to the challenging conditions inherent to the space environment and the possible solar concentration levels in which an array of modules might be required to operate. The research described herein details our team's efforts in the development of photovoltaic arrays, power electronics, microwave conversion electronics, and antennas for microwave-based "sandwich" module prototypes. The implementation status and testing results of the prototypes are reviewed.

  15. Variable stiffness sandwich panels using electrostatic interlocking core

    Science.gov (United States)

    Heath, Callum J. C.; Bond, Ian P.; Potter, Kevin D.

    2016-04-01

    Structural topology has a large impact on the flexural stiffness of a beam structure. Reversible attachment between discrete substructures allows for control of shear stress transfer between structural elements, thus stiffness modulation. Electrostatic adhesion has shown promise for providing a reversible latching mechanism for controllable internal connectivity. Building on previous research, a thin film copper polyimide laminate has been used to incorporate high voltage electrodes to Fibre Reinforced Polymer (FRP) sandwich structures. The level of electrostatic holding force across the electrode interface is key to the achievable level of stiffness modulation. The use of non-flat interlocking core structures can allow for a significant increase in electrode contact area for a given core geometry, thus a greater electrostatic holding force. Interlocking core geometries based on cosine waves can be Computer Numerical Control (CNC) machined from Rohacell IGF 110 Foam core. These Interlocking Core structures could allow for enhanced variable stiffness functionality compared to basic planar electrodes. This novel concept could open up potential new applications for electrostatically induced variable stiffness structures.

  16. Homogeneous and sandwich active panels under deterministic and stochastic excitation.

    Science.gov (United States)

    Rohlfing, J; Gardonio, P

    2009-06-01

    In this paper an element-based model is used to predict the structural response and sound radiation of two smart panels excited by (a) an acoustic plane wave, (b) a stochastic acoustic diffuse field, and (c) a turbulent boundary layer. The first panel is made of aluminum, while the second is a composite sandwich panel with equivalent static stiffness but four times lower mass per unit area. The panels are equipped with 16 decentralized velocity feedback control loops using idealized point force actuators. In contrast to previous studies on smart panels, the analysis is extended to the upper end of the audio frequency range. In this frequency region the response and sound radiation of the panels strongly depend on the spatial characteristics of the excitation field and the sound radiation properties with respect to the bending wavelength on the panels. Considerable reduction in structural response and sound radiation is predicted for the low audio frequency range where the panel response is dominated by well separated resonances of low order structural modes. It is also found that some reduction can be achieved around acoustic and convective coincidence regions.

  17. Dispersion of Lamb waves in a honeycomb composite sandwich panel.

    Science.gov (United States)

    Baid, Harsh; Schaal, Christoph; Samajder, Himadri; Mal, Ajit

    2015-02-01

    Composite materials are increasingly being used in advanced aircraft and aerospace structures. Despite their many advantages, composites are often susceptible to hidden damages that may occur during manufacturing and/or service of the structure. Therefore, safe operation of composite structures requires careful monitoring of the initiation and growth of such defects. Ultrasonic methods using guided waves offer a reliable and cost effective method for defects monitoring in advanced structures due to their long propagation range and their sensitivity to defects in their propagation path. In this paper, some of the useful properties of guided Lamb type waves are investigated, using analytical, numerical and experimental methods, in an effort to provide the knowledge base required for the development of viable structural health monitoring systems for composite structures. The laboratory experiments involve a pitch-catch method in which a pair of movable transducers is placed on the outside surface of the structure for generating and recording the wave signals. The specific cases considered include an aluminum plate, a woven composite laminate and an aluminum honeycomb sandwich panel. The agreement between experimental, numerical and theoretical results are shown to be excellent in certain frequency ranges, providing a guidance for the design of effective inspection systems.

  18. Preparation of monoclonal antibodies against bovine viral diarrhea virus and the double antibody sandwich ELISA develpoment%抗牛病毒性腹泻病毒单克隆抗体的制备及双抗夹心ELISA检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    蒋颖; 朱国强; 林燕清; 陶洁; 孟祥升; 段小丽; 王娟; 王银; 张信军; 王建业

    2012-01-01

    为建立牛病毒性腹泻病毒(BVDV)双抗夹心ELISA检测方法,本研究将BVDV 890病毒株(BVDV-2)浓缩并纯化后免疫BALB/c小鼠,经常规技术进行细胞融合并筛选得到一株稳定分泌IgG的杂交瘤细胞株,命名为3F9.以BVDV单克隆抗体(MAb) IgM为捕获抗体,生物素标记的3F9为检测抗体,初步建立BVDV特异的双抗体夹心ELISA检测方法(BAS-ELISA).采用建立的BAS-ELISA方法检测35份临床病牛血清样品,检出阳性样本13份;与RT-PCR的符合率达到94.29%;表明本研究所建立的BAS-ELISA方法可用于BVDV感染的临床诊断,为BVDV的免疫学研究奠定了基础.%To establish a double monoclonal antibody (MAb)-mediated sandwich ELISA (DAS-ELISA) for detection of bovine viral diarrhea virus (BVDV), the MAb 3D8 (IgM) and biotin-labelled 3F9 (IgG) were used as capture antibody and detection antibody respectively after obtaining a hybridoma cell line stably secreting antibody (3F9). Thirty-five clinically suspected sera samples were detected by this method and the results of 13 samples were positive. Compared with RT-PCR in the paralled experiment with 11 samples positive, the coincidence rate was 94.25%. It is suggested that the DAS-ELISA was a potentially valuable method with high sensitivity and specificity against BVDV.

  19. Liposomal co-entrapment of CD40mAb induces enhanced IgG responses against bacterial polysaccharide and protein.

    Directory of Open Access Journals (Sweden)

    Caterina Hatzifoti

    Full Text Available BACKGROUND: Antibody against CD40 is effective in enhancing immune responses to vaccines when chemically conjugated to the vaccine antigen. Unfortunately the requirement for chemical conjugation presents some difficulties in vaccine production and quality control which are compounded when multivalent vaccines are required. We explore here an alternative to chemical conjugation, involving the co-encapsulation of CD40 antibody and antigens in liposomal vehicles. METHODOLOGY/PRINCIPAL FINDINGS: Anti-mouse CD40 mAb or isotype control mAb were co-entrapped individually in cationic liposomal vehicles with pneumococcal polysaccharides or diphtheria and tetanus toxoids. Retention of CD40 binding activity upon liposomal entrapment was assessed by ELISA and flow cytometry. After subcutaneous immunization of BALB/c female mice, anti-polysaccharide and DT/TT responses were measured by ELISA. Simple co-encapsulation of CD40 antibody allowed for the retention of CD40 binding on the liposome surface, and also produced vaccines with enhanced imunogenicity. Antibody responses against both co-entrapped protein in the form of tetanus toxoid, and Streptococcus pneumoniae capsular polysaccharide, were enhanced by co-encapsulation with CD40 antibody. Surprisingly, liposomal encapsulation also appeared to decrease the toxicity of high doses of CD40 antibody as assessed by the degree of splenomegaly induced. CONCLUSIONS/SIGNIFICANCE: Liposomal co-encapsulation with CD40 antibody may represent a practical means of producing more immunogenic multivalent vaccines and inducing IgG responses against polysaccharides without the need for conjugation.

  20. Quantitative definition and monitoring of the host cell protein proteome using iTRAQ - a study of an industrial mAb producing CHO-S cell line.

    Science.gov (United States)

    Chiverton, Lesley M; Evans, Caroline; Pandhal, Jagroop; Landels, Andrew R; Rees, Byron J; Levison, Peter R; Wright, Phillip C; Smales, C Mark

    2016-08-01

    There are few studies defining CHO host cell proteins (HCPs) and the flux of these throughout a downstream purification process. Here we have applied quantitative iTRAQ proteomics to follow the HCP profile of an antibody (mAb) producing CHO-S cell line throughout a standard downstream purification procedure consisting of a Protein A, cation and anion exchange process. We used both 6 sample iTRAQ experiment to analyze technical replicates of three samples, which were culture harvest (HCCF), Protein A flow through and Protein A eluate and an 8 sample format to analyze technical replicates of four sample types; HCCF compared to Protein A eluate and subsequent cation and anion exchange purification. In the 6 sample iTRAQ experiment, 8781 spectra were confidently matched to peptides from 819 proteins (including the mAb chains). Across both the 6 and 8 sample experiments 936 proteins were identified. In the 8 sample comparison, 4187 spectra were confidently matched to peptides from 219 proteins. We then used the iTRAQ data to enable estimation of the relative change of individual proteins across the purification steps. These data provide the basis for application of iTRAQ for process development based upon knowledge of critical HCPs. © 2016 The Authors. Biotechnology Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. lmmunofiuorescent Labeling of Human HepG2 Cells with CdTe Quantum Dot Probe Conjugated with Anti-pan CK MAb

    Institute of Scientific and Technical Information of China (English)

    SUI Yu-jie; ZHANG Gui-zhen; WANG Qian; WANG Ya-li; WU Mei; DU Zhen-wu; ZHANG Jie; JIANG Ri-hua

    2011-01-01

    A relatively sensitive, specific, and photostable method for the detection of cytokeratin of cancer cells via conjugation with cadmium telluride quantum dots(CdTe QDs) was described. Water soluble CdTe QDs were conjugated to anti-pan-cytokeratin(CK) monoclonal antibody(MAb) through coupling reagent [1-ethyi-3-(3-dimethylamino propyl)carbodiimide, EDC] and the conjugates were purified by dialysis. The expression of pan CK protein in HepG2 cells was observed by immunocytochemistry and direct immunofluorescence via QDs-Ab conjugates respectively. Fluorescence intensity and photostability of QDs were compared with those of FITC(fiuorescein isothiocyanate). The results show that the QDs-Ab conjugates recognized specifically pan CK protein in HepG2 cells. Compared with FITC, CdTe QDs had higher brightness and photostability without obvious photobleaching under continuous exciting light illumination for 30 min and after the placement at room temperature for 3 d. The results indicate that conjugates of CdTe quantum dot with anti-pan CK MAb can be used for labeling cancer cells derived from epithelial tissues, which provides the basis for the detection of circulating tumor cells(CTCs).

  2. Elucidating the Weak Protein-Protein Interaction Mechanisms behind the Liquid-Liquid Phase Separation of a mAb Solution by Different Types of Additives.

    Science.gov (United States)

    Wu, Guoliang; Wang Co-First, Shujing; Tian, Zhou; Zhang, Ning; Sheng, Han; Dai, Weiguo; Qian, Feng

    2017-07-25

    Liquid-liquid phase separation (LLPS) has long been observed during the physical stability investigation of therapeutic protein formulations. The buffer conditions and the presence of various excipients are thought to play important roles in the formulation development of monoclonal antibodies (mAbs). In this study, the effects of several small-molecule excipients (histidine, alanine, glycine, sodium phosphate, sodium chloride, sorbitol and sucrose) with diverse physical-chemical properties on LLPS of a model IgG1 (JM2) solutions were investigated by multiple techniques, including UV-vis spectroscopy, circular dichroism, differential scanning calorimetry/fluorimetry, size exclusion chromatography and dynamic light scattering. The LLPS of JM2 was confirmed to be a thermodynamic equilibrium process with no structural changes or irreversible aggregation of proteins. Phase diagrams of various JM2 formulations were constructed, suggesting that the phase behavior of JM2 was dependent on the solution pH, ionic strength and the presence of other excipients such as glycine, alanine, sorbitol and sucrose. Furthermore, we demonstrated that for this mAb, the interaction parameter (kD) determined at low protein concentration appeared to be a good predictor for the occurrence of LLPS at high concentration. Copyright © 2017. Published by Elsevier B.V.

  3. Systemic administration of Abeta mAb reduces retinal deposition of Abeta and activated complement C3 in age-related macular degeneration mouse model.

    Directory of Open Access Journals (Sweden)

    Ian Catchpole

    Full Text Available Age-related macular degeneration (AMD is a leading cause of legal blindness in the Western world. There are effective treatments for the vascular complications of neo-vascular AMD, but no effective therapies are available for the dry/atrophic form of the disease. A previously described transgenic CFH-gene deficient mouse model, (cfh-/-, shows hallmarks of early AMD. The ocular phenotype has been further analysed to demonstrate amyloid beta (Aβ rich basement membrane deposits associated with activated complement C3. Cfh-/- mice were treated systemically in both prophylactic and therapeutic regimes with an anti-Aβ monoclonal antibody (mAb, 6F6, to determine the effect on the cfh-/- retinal phenotype. Prophylactic treatment with 6F6 demonstrated a dose dependent reduction in the accumulation of both Aβ and activated C3 deposition. A similar reduction in the retinal endpoints could be seen after therapeutic treatment. Serum Aβ levels after systemic administration of 6F6 show accumulation of Aβ in the periphery suggestive of a peripheral sink mechanism. In summary, anti-Aβ mAb treatment can partially prevent or reverse ocular phenotypes of the cfh-/- mouse. The data support this therapeutic approach in humans potentially modulating two key elements in the pathogenesis of AMD - Aβ and activated, complement C3.

  4. A quantitative exposure model simulating human norovirus transmission during preparation of deli sandwiches.

    Science.gov (United States)

    Stals, Ambroos; Jacxsens, Liesbeth; Baert, Leen; Van Coillie, Els; Uyttendaele, Mieke

    2015-03-02

    Human noroviruses (HuNoVs) are a major cause of food borne gastroenteritis worldwide. They are often transmitted via infected and shedding food handlers manipulating foods such as deli sandwiches. The presented study aimed to simulate HuNoV transmission during the preparation of deli sandwiches in a sandwich bar. A quantitative exposure model was developed by combining the GoldSim® and @Risk® software packages. Input data were collected from scientific literature and from a two week observational study performed at two sandwich bars. The model included three food handlers working during a three hour shift on a shared working surface where deli sandwiches are prepared. The model consisted of three components. The first component simulated the preparation of the deli sandwiches and contained the HuNoV reservoirs, locations within the model allowing the accumulation of NoV and the working of intervention measures. The second component covered the contamination sources being (1) the initial HuNoV contaminated lettuce used on the sandwiches and (2) HuNoV originating from a shedding food handler. The third component included four possible intervention measures to reduce HuNoV transmission: hand and surface disinfection during preparation of the sandwiches, hand gloving and hand washing after a restroom visit. A single HuNoV shedding food handler could cause mean levels of 43±18, 81±37 and 18±7 HuNoV particles present on the deli sandwiches, hands and working surfaces, respectively. Introduction of contaminated lettuce as the only source of HuNoV resulted in the presence of 6.4±0.8 and 4.3±0.4 HuNoV on the food and hand reservoirs. The inclusion of hand and surface disinfection and hand gloving as a single intervention measure was not effective in the model as only marginal reductions of HuNoV levels were noticeable in the different reservoirs. High compliance of hand washing after a restroom visit did reduce HuNoV presence substantially on all reservoirs. The

  5. Failure characteristics of a thin metallic sandwich plate with metallic sheared dimple cores under low-velocity impact loading

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Dong Gyu; Jeong, Woo Chul [Chosun University, Gwangju (Korea, Republic of)

    2013-10-15

    The functionality and the performance of a lightweight sandwich plate with periodic cellular metal (PCM) cores are influenced by failure characteristics of the lightweight sandwich plate. The goal of this paper is to investigate the failure characteristics of a thin metallic sandwich plate with metallic sheared dimple cores under low-velocity impact loading through nonlinear finite element analysis. The influence of the imperfection mode of the cores on the impact response of a thin sandwich plate is examined to obtain a proper simulation model. Repeated finite element analyses are performed to examine the failure modes of the sandwich plate for different impact conditions. Normalized impact parameters are defined in order to generalize a dynamic failure map (DFM). DFMs of the thin metallic sandwich plate have been estimated via the regression analysis of critical impact conditions for each failure mode. In addition, the influence of the normalized impact parameters on the failure mode has been investigated using the DFM.

  6. The optimum layer number of multi-layer pyramidal core sandwich columns under in-plane compression

    Institute of Scientific and Technical Information of China (English)

    Li-Jia Feng; Lin-Zhi Wu∗; Guo-Cai Yu

    2016-01-01

    The effect of the face thickness to core height ratio on different multi-layer pyramidal core sandwich columns under in-plane compression is investigated theoretically and numerically. Numerical simulation is in good agreement with theory. Results indicate that one specified face thickness to core height ratio corresponds to one optimum layer number of multi-layer pyramidal core sandwich columns in consideration of engineering application. This result can guide the sandwich structure design.

  7. A Study of the Efficiency of High-strength, Steel, Cellular-core Sandwich Plates in Compression

    Science.gov (United States)

    Johnson, Aldie E , Jr; Semonian, Joseph W

    1956-01-01

    Structural efficiency curves are presented for high-strength, stainless-steel, cellular-core sandwich plates of various proportions subjected to compressive end loads for temperatures of 80 F and 600 F. Optimum proportions of sandwich plates for any value of the compressive loading intensity can be determined from the curves. The efficiency of steel sandwich plates of optimum proportions is compared with the efficiency of solid plates of high-strength steel and aluminum and titanium alloys at the two temperatures.

  8. Buckling analysis of curved composite sandwich panels subjected to inplane loadings

    Science.gov (United States)

    Cruz, Juan R.

    1993-01-01

    Composite sandwich structures are being considered for primary structure in aircraft such as subsonic and high speed civil transports. The response of sandwich structures must be understood and predictable to use such structures effectively. Buckling is one of the most important response mechanisms of sandwich structures. A simple buckling analysis is derived for sandwich structures. This analysis is limited to flat, rectangular sandwich panels loaded by uniaxial compression (N(sub x)) and having simply supported edges. In most aerospace applications, however, the structure's geometry, boundary conditions, and loading are usually very complex. Thus, a general capability for analyzing the buckling behavior of sandwich structures is needed. The present paper describes and evaluates an improved buckling analysis for cylindrically curved composite sandwich panels. This analysis includes orthotropic facesheets and first-order transverse shearing effects. Both simple support and clamped boundary conditions are also included in the analysis. The panels can be subjected to linearly varying normal loads N(sub x) and N(sub y) in addition to a constant shear load N(sub xy). The analysis is based on the modified Donnell's equations for shallow shells. The governing equations are solved by direct application of Galerkin's method. The accuracy of the present analysis is verified by comparing results with those obtained from finite element analysis for a variety of geometries, loads, and boundary conditions. The limitations of the present analysis are investigated, in particular those related to the shallow shell assumptions in the governing equations. Finally, the computational efficiency of the present analysis is considered.

  9. Measuring Moisture Levels in Graphite Epoxy Composite Sandwich Structures

    Science.gov (United States)

    Nurge, Mark; Youngquist, Robert; Starr, Stanley

    2011-01-01

    Graphite epoxy composite (GEC) materials are used in the construction of rocket fairings, nose cones, interstage adapters, and heat shields due to their high strength and light weight. However, they absorb moisture depending on the environmental conditions they are exposed to prior to launch. Too much moisture absorption can become a problem when temperature and pressure changes experienced during launch cause the water to vaporize. The rapid state change of the water can result in structural failure of the material. In addition, heat and moisture combine to weaken GEC structures. Diffusion models that predict the total accumulated moisture content based on the environmental conditions are one accepted method of determining if the material strength has been reduced to an unacceptable level. However, there currently doesn t exist any field measurement technique to estimate the actual moisture content of a composite structure. A multi-layer diffusion model was constructed with Mathematica to predict moisture absorption and desorption from the GEC sandwich structure. This model is used in conjunction with relative humidity/temperature sensors both on the inside and outside of the material to determine the moisture levels in the structure. Because the core materials have much higher diffusivity than the face sheets, a single relative humidity measurement will accurately reflect the moisture levels in the core. When combined with an external relative humidity measurement, the model can be used to determine the moisture levels in the face sheets. Since diffusion is temperaturedependent, the temperature measurements are used to determine the diffusivity of the face sheets for the model computations.

  10. {sup 6}Li foil scintillation sandwich thermal neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ianakiev, K.D., E-mail: ianakiev@lanl.gov [Los Alamos National Laboratory, MS E540, Los Alamos, NM 87545 (United States); Swinhoe, M.T.; Favalli, A.; Chung, K.; MacArthur, D.W. [Los Alamos National Laboratory, MS E540, Los Alamos, NM 87545 (United States)

    2011-10-01

    Increasing needs for neutron detection and limited supply of {sup 3}He have led to the need for replacement neutron detection technology. This paper presents the design and initial results for a neutron detector ({sup 6}Li foil scintillator sandwich) that uses lithium metal foil to detect thermal neutrons. The reaction products, primarily triton, deposit most of their energy in thin scintillator films and create light pulses. Gamma rays can deposit only a small amount of energy in the thin films and so produce only very small light pulses. Lithium is preferable to boron in this application because triton escapes from lithium more easily than does the alpha particle from boron, allowing the use of thicker films and hence greater efficiency. In addition, triton has a higher light output in the scintillator than the boron alpha particle. Lithium metal is preferable to a lithium compound, such as lithium fluoride, because the number of tritons that escape from the metal is greater for the same amount of lithium. Monte Carlo simulations show that good efficiency values can be achieved with reasonably sized detectors, values that are greater than that of comparable {sup 3}He systems for portal monitors. In addition, simulations of a neutron coincidence counting concept show high counting efficiency and short die-away time (16 {mu}s), which imply better performance than that of the high-level neutron coincidence counter (HLNCC)-II. Initial experimental measurements on a prototype detector using alpha particles (having similar light output to the expected tritons) show good light collection and transport properties.

  11. A Refined Zigzag Beam Theory for Composite and Sandwich Beams

    Science.gov (United States)

    Tessler, Alexander; Sciuva, Marco Di; Gherlone, Marco

    2009-01-01

    A new refined theory for laminated composite and sandwich beams that contains the kinematics of the Timoshenko Beam Theory as a proper baseline subset is presented. This variationally consistent theory is derived from the virtual work principle and employs a novel piecewise linear zigzag function that provides a more realistic representation of the deformation states of transverse-shear flexible beams than other similar theories. This new zigzag function is unique in that it vanishes at the top and bottom bounding surfaces of a beam. The formulation does not enforce continuity of the transverse shear stress across the beam s cross-section, yet is robust. Two major shortcomings that are inherent in the previous zigzag theories, shear-force inconsistency and difficulties in simulating clamped boundary conditions, and that have greatly limited the utility of these previous theories are discussed in detail. An approach that has successfully resolved these shortcomings is presented herein. Exact solutions for simply supported and cantilevered beams subjected to static loads are derived and the improved modelling capability of the new zigzag beam theory is demonstrated. In particular, extensive results for thick beams with highly heterogeneous material lay-ups are discussed and compared with corresponding results obtained from elasticity solutions, two other zigzag theories, and high-fidelity finite element analyses. Comparisons with the baseline Timoshenko Beam Theory are also presented. The comparisons clearly show the improved accuracy of the new, refined zigzag theory presented herein over similar existing theories. This new theory can be readily extended to plate and shell structures, and should be useful for obtaining relatively low-cost, accurate estimates of structural response needed to design an important class of high-performance aerospace structures.

  12. Specific Binding of 17D3 Anti-pZP mAb to Porcine and Human Zona Pellucida but not to Other Tissue Antigens Identified by ABC Immunohistochemistry

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective To characterize the binding effects of 1 7D3 anti-pZP monoclonal antibody (mAb) on porcine and human ZP, ovary and other important tissues Methods The 1 7D3 anti-pZP mAb was produced by immunizing mouse with porcine zona pellucida and hybridoma and monoclonal antibody preparation. An ABCimmunohistochemistry was used to evaluate reaction of mAb 17D3pZP to porcine and human ZP antigens as well as important human tissue antigens.Results mAb 1 7D3pZP specifically bound to porcine and human ZP antigen, but not to other cells of ovaries and other important human tissue antigens.Conclusion 17D3 anti-pZP mAb can recognize porcine and human ZP antigen without cross-reaction with other human tissue antigens including ovary, so it may further help us to abstract and purify corresponding target antigen and settle basis for producing human ZP contraceptive vaccine.

  13. Hypervelocity Impact Performance of Open Cell Foam Core Sandwich Panel Structures

    Science.gov (United States)

    Ryan, Shannon; Christiansen, Eric; Lear, Dana

    2009-01-01

    Metallic foams are a relatively new class of materials with low density and novel physical, mechanical, thermal, electrical and acoustic properties. Although incompletely characterized, they offer comparable mechanical performance to traditional spacecraft structural materials (i.e. honeycomb sandwich panels) without detrimental through-thickness channeling cells. There are two competing types of metallic foams: open cell and closed cell. Open cell foams are considered the more promising technology due to their lower weight and higher degree of homogeneity. Leading micrometeoroid and orbital debris shields (MMOD) incorporate thin plates separated by a void space (i.e. Whipple shield). Inclusion of intermediate fabric layers, or multiple bumper plates have led to significant performance enhancements, yet these shields require additional non-ballistic mass for installation (fasteners, supports, etc.) that can consume up to 35% of the total shield weight [1]. Structural panels, such as open cell foam core sandwich panels, that are also capable of providing sufficient MMOD protection, represent a significant potential for increased efficiency in hypervelocity impact shielding from a systems perspective through a reduction in required non-ballistic mass. In this paper, the results of an extensive impact test program on aluminum foam core sandwich panels are reported. The effect of pore density, and core thickness on shielding performance have been evaluated over impact velocities ranging from 2.2 - 9.3 km/s at various angles. A number of additional tests on alternate sandwich panel configurations of comparable-weight have also been performed, including aluminum honeycomb sandwich panels (see Figure 1), Nomex honeycomb core sandwich panels, and 3D aluminum honeycomb sandwich panels. A total of 70 hypervelocity impact tests are reported, from which an empirical ballistic limit equation (BLE) has been derived. The BLE is in the standard form suitable for implementation in

  14. Comparison of manufacturing of lightweight corrugated sheet sandwiches by hydroforming and incremental sheet forming

    Science.gov (United States)

    Maqbool, Fawad; Elze, Lars; Seidlitz, Holger; Bambach, Markus

    2016-10-01

    Sandwich materials made from corrugated sheet metal provide excellent mechanical properties for lightweight design without using filler material. The increased mechanical properties of these sandwich materials are achieved by the 3-D geometry of the corrugated sheet and the hardening due to pre-forming. In the present study, manufacturing of corrugated sheet metal consisting of hexagonal bulge patterns through hydroforming and incremental forming is analyzed. Double layered corrugated sheet metal sandwiches with hexagonal patterns of free-form bulge geometries are investigated through finite element analysis for the maximum increase in stiffness over the normal flat sheets. The analysis shows that a bending stiffness increase of up to 13 times over flat sheet of the same mass is attainable by corrugated sandwiches. Further, it is proved for these types of corrugation sandwiches that stiffness increases by increasing the height of the corrugation bulge but that hydroforming poses restrictions with respect to bulge height, since it is limited by forming force and formability of the material. Incremental sheet metal forming can be used to produce sheets with a hexagonal bulge pattern with increased height. Hence, a higher increase in stiffness as compared to hydroforming is possible but at the expense of process speed.

  15. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-02-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as materialalternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforcedplastics single skin. The weakness of this FRP was heavy construction and requires many production time.Therefore, will be checked comparison between single skin with sandwich constructions for shell.In this research, the way for making composite is hand lay up method with three various thickness of skinthere are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin,must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesiarules for the fiberglass ship.Based on the result, indicates that optimization skin thickness of sandwich construction applies Corematwhich tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT.Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  16. Analysis of Stainless Steel Sandwich Panels with a Metal Foam Care for Lightweight Fan Blade Design

    Science.gov (United States)

    Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

    2004-01-01

    The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. Traditionally, these components have been fabricated using expensive materials such as light weight titanium alloys, polymeric composite materials and carbon-carbon composites. The present study investigates the use of P sandwich foam fan blade made up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The stiffness of the sandwich structure is increased by separating the two face sheets by a foam core. The resulting structure possesses a high stiffness while being lighter than a similar solid construction. Since the face sheets carry the applied bending loads, the sandwich architecture is a viable engineering concept. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of the sandwich structure for a fan blade application. A vibration analysis for natural frequencies and P detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of skin thickness and core volume %re presented with a comparison to a solid titanium blade.

  17. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-04-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as material alternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforced plastics single skin. The weakness of this FRP was heavy construction and requires many production time. Therefore, will be checked comparison between single skin with sandwich constructions for shell. In this research, the way for making composite is hand lay up method with three various thickness of skin there are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin, must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesia rules for the fiberglass ship. Based on the result, indicates that optimization skin thickness of sandwich construction applies Coremat which tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes 23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT. Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  18. Finite Element Analysis of Bend Test of Sandwich Structures Using Strain Energy Based Homogenization Method

    Directory of Open Access Journals (Sweden)

    Hassan Ijaz

    2017-01-01

    Full Text Available The purpose of this article is to present a simplified methodology for analysis of sandwich structures using the homogenization method. This methodology is based upon the strain energy criterion. Normally, sandwich structures are composed of hexagonal core and face sheets and a complete and complex hexagonal core is modeled for finite element (FE structural analysis. In the present work, the hexagonal core is replaced by a simple equivalent volume for FE analysis. The properties of an equivalent volume were calculated by taking a single representative cell for the entire core structure and the analysis was performed to determine the effective elastic orthotropic modulus of the equivalent volume. Since each elemental cell of the hexagonal core repeats itself within the in-plane direction, periodic boundary conditions were applied to the single cell to obtain the more realistic values of effective modulus. A sandwich beam was then modeled using determined effective properties. 3D FE analysis of Three- and Four-Point Bend Tests (3PBT and 4PBT for sandwich structures having an equivalent polypropylene honeycomb core and Glass Fiber Reinforced Plastic (GFRP composite face sheets are performed in the present study. The authenticity of the proposed methodology has been verified by comparing the simulation results with the experimental bend test results on hexagonal core sandwich beams.

  19. Designing novel thin film polycrystalline solar cells for high efficiency: sandwich CIGS and heterojunction perovskite

    Science.gov (United States)

    Wang, Tianyue; Chen, Jiewei; Wu, Gaoxiang; Song, Dandan; Li, Meicheng

    2017-01-01

    Heterojunction and sandwich architectures are two new-type structures with great potential for solar cells. Specifically, the heterojunction structure possesses the advantages of efficient charge separation but suffers from band offset and large interface recombination; the sandwich configuration is favorable for transferring carriers but requires complex fabrication process. Here, we have designed two thin-film polycrystalline solar cells with novel structures: sandwich CIGS and heterojunction perovskite, referring to the advantages of the architectures of sandwich perovskite (standard) and heterojunction CIGS (standard) solar cells, respectively. A reliable simulation software wxAMPS is used to investigate their inherent characteristics with variation of the thickness and doping density of absorber layer. The results reveal that sandwich CIGS solar cell is able to exhibit an optimized efficiency of 20.7%, which is much higher than the standard heterojunction CIGS structure (18.48%). The heterojunction perovskite solar cell can be more efficient employing thick and doped perovskite films (16.9%) than these typically utilizing thin and weak-doping/intrinsic perovskite films (9.6%). This concept of structure modulation proves to be useful and can be applicable for other solar cells. Project supported by the National High-Tech R&D Program of China (No. 2015AA034601), the National Natural Science Foundation of China (Nos. 91333122, 61204064, 51202067, 51372082, 51402106, 11504107), the Ph.D. Programs Foundation of Ministry of Education of China (Nos. 20120036120006, 20130036110012), the Par-Eu Scholars Program, and the Fundamental Research Funds for the Central Universities.

  20. Long-term hygrothermal effects on damage tolerance of hybrid composite sandwich panels

    Science.gov (United States)

    Ishai, Ori; Hiel, Clement; Luft, Michael

    1995-01-01

    A sandwich construction, composed of hybrid carbon-glass fiber-reinforced plastic skins and a syntactic foam core, was selected as the design concept for a wind tunnel compressor blade application, where high damage tolerance and durability are of major importance. Beam specimens were prepared from open-edge and encapsulated sandwich panels which had previously been immersed in water at different temperatures for periods of up to about two years in the extreme case. Moisture absorption and strength characteristics, as related to time of exposure to hygrothermal conditions, were evaluated for the sandwich specimens and their constituents (skins and foam). After different exposure periods, low-velocity impact damage was inflicted on most sandwich specimens and damage characteristics were related to impact energy. Eventually, the residual compressive strengths of the damaged (and undamaged) beams were determined flexurally. Test results show that exposure to hygrothermal conditions leads to significant strength reductions for foam specimens and open-edge sandwich panels, compared with reference specimens stored at room temperature. In the case of skin specimens and for beams prepared from encapsulated sanwich panels that had previously been exposed to hygrothermal conditions, moisture absorption was found to improve strength as related to the reference case. The beneficial effect of moisture on skin performance was, however, limited to moisture contents below 1% (at 50 C and lower temperatures). Above this moisture level and at higher temperatures, strength degradation of the skin seems to prevail.

  1. Stability and post-buckling response of sandwich pipes under hydrostatic external pressure

    Energy Technology Data Exchange (ETDEWEB)

    Arjomandi, Kaveh [Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS B3J 1Z1 (Canada); Taheri, Farid, E-mail: farid.taheri@dal.ca [Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS B3J 1Z1 (Canada)

    2011-04-15

    Sandwich pipe systems can be considered as potentially optimum design configurations for overcoming the shortfalls of single-walled pipes for deep-water applications. This potential design alternative has gained considerable attention in recent years. In this paper the stability of these systems is investigated. The possible equilibrium paths are evaluated and the effect of the various significant parameters on the characteristic behavior of the system is discussed. The Finite Element (FE) software package ABAQUS is used to construct more than 3000 FE models of the sandwich pipes with practical configurations. Four design configurations are considered for the sandwich pipes with respect to the adhesion among the interfaces. The post-buckling behavior of each of these configurations is determined, with emphasis on a wide practical range of parameters. The behavior of these configurations is examined and the efficiency of each system is discussed. Finally, a simplified and fairly accurate equation is developed and recommended for calculating the pressure capacity of sandwich pipes. The parameters of the proposed equation are also fully defined. - Highlights: > The stability of sandwich pipes (SP) in deep water is investigated. > 3000 FE models of SP with practical configurations were constructed and analyzed. > The possible equilibrium paths are evaluated and the effect of the various significant parameters is discussed. > The interface core/pipe adhesion is also investigated and shown to have significant impact on the stability. > Finally, a simplified and fairly accurate equation is developed for calculating the pressure capacity of SP.

  2. Overall Buckling and Wringkling of Debonded Sandwich Beams: Finite Element and Experimental Results

    Directory of Open Access Journals (Sweden)

    Bambang K. Hadi

    2006-05-01

    Full Text Available Overall buckling and wrinkling of debonded sandwich beams under compressive loads were analyzed by both finite element and experimental methods. In the finite element method, a quarter and a half models of the specimens were analyzed. It shows that a quarter model is not adequate to analyze buckling of debonded sandwich beams, since it will disregard overall buckling mode that may occur in sandwich beams having compressive loads. At least a half model should be used to analyze buckling of sandwich beams. A finite element program UNA was used extensively to analyze the buckling loads. Experimental buckling of sandwich beams was carried out using a compression testing machine. Two LVDTs were used to measure deflections of the specimen during experimental loading. The loads were measured using load cells available in the machine. Specimens having core thickness of 45 and 75 mm were tested to represent overall and wrinkling modes respectively. The delamination lengths were 20, 60 and 80 mm, which represent 10, 30 and 40% of the beam length. The results show that the differences between experimental and finite element methods were less than 10%. Both overall buckling and wrinkling modes were shown in these specimens.

  3. Study of Debond Fracture Toughness of Sandwich Composites with Metal Foam Core

    Institute of Scientific and Technical Information of China (English)

    Xinzhu Wang; Linzhi Wu; Shixun Wang

    2009-01-01

    Two types of experiments were designed and performed to evaluate the adhesive bond in metal foam composite sandwich structures. The tensile bond strength of face/core was determined through the flatwise tensile test (FWT). The test results show that the interfacial peel strength is lower than the interlaminar peel strength in FWT test. The mode I interfacial fracture toughness (GIC) of sandwich structures containing a pre-crack on the upper face/core interface is determined by modified cracked sandwich beam (MCSB) experiment. It is found that the crack propagates unsynchronously on the two side of the specimen and the propagation of interfacial debonding always stays on the face/core interface during the MCSB tests. In order to simulate the failure of metal foam composite sandwich structures, a computational model based on the Tsai-Hill failure criterion and cohesive zone model is used. By comparing with experiment results, it can be concluded that the computational model can validly simulate the interfacial failure of metal foam composite sandwich structures with reasonable accuracy.

  4. Thermostructural Behavior of a Hypersonic Aircraft Sandwich Panel Subjected to Heating on One Side

    Science.gov (United States)

    Ko, William L.

    1997-01-01

    Thermostructural analysis was performed on a heated titanium honeycomb-core sandwich panel. The sandwich panel was supported at its four edges with spar-like substructures that acted as heat sinks, which are generally not considered in the classical analysis. One side of the panel was heated to high temperature to simulate aerodynamic heating during hypersonic flight. Two types of surface heating were considered: (1) flat-temperature profile, which ignores the effect of edge heat sinks, and (2) dome-shaped-temperature profile, which approximates the actual surface temperature distribution associated with the existence of edge heat sinks. The finite-element method was used to calculate the deformation field and thermal stress distributions in the face sheets and core of the sandwich panel. The detailed thermal stress distributions in the sandwich panel are presented, and critical stress regions are identified. The study shows how the magnitudes of those critical stresses and their locations change with different heating and edge conditions. This technical report presents comprehensive, three-dimensional graphical displays of thermal stress distributions in every part of a titanium honeycomb-core sandwich panel subjected to hypersonic heating on one side. The plots offer quick visualization of the structural response of the panel and are very useful for hot structures designers to identify the critical stress regions.

  5. Flexural wave attenuation in a sandwich beam with viscoelastic periodic cores

    Science.gov (United States)

    Guo, Zhiwei; Sheng, Meiping; Pan, Jie

    2017-07-01

    The flexural-wave attenuation performance of traditional constraint-layer damping in a sandwich beam is improved by using periodic constrained-layer damping (PCLD), where the monolithic viscoelastic core is replaced with two periodically alternating viscoelastic cores. Closed-form solutions of the wave propagation constants of the infinite periodic sandwich beam and the forced response of the corresponding finite sandwich structure are theoretically derived, providing computational support on the analysis of attenuation characteristics. In a sandwich beam with PCLD, the flexural waves can be attenuated by both Bragg scattering effect and damping effect, where the attenuation level is mainly dominated by Bragg scattering in the band-gaps and by damping in the pass-bands. Affected by these two effects, when the parameters of periodic cores are properly selected, a sandwich beam with PCLD can effectively reduce vibrations of much lower frequencies than that with traditional constrained-layer damping. The effects of the parameters of viscoelastic periodic cores on band-gap properties are also discussed, showing that the average attenuation in the desired frequency band can be maximized by tuning the length ratio and core thickness to proper values. The research in this paper could possibly provide useful information for the researches and engineers to design damping structures.

  6. Viewpoints of working sandwich generation women and occupational therapists on role balance strategies.

    Science.gov (United States)

    Evans, Kiah L; Girdler, Sonya J; Falkmer, Torbjorn; Richmond, Janet E; Wagman, Petra; Millsteed, Jeannine; Falkmer, Marita

    2017-09-01

    Occupational therapists need to be cognizant of evidence-based role balance advice and strategies that women with multigenerational caring responsibilities can implement independently or with minimal assistance, as role balance may not be the primary goal during many encounters with this population. Hence, this study aimed to identify the viewpoints on the most helpful role balance strategies for working sandwich generation women, both from their own perspectives and from the perspective of occupational therapists. This was achieved through a Q methodology study, where 54 statements were based on findings from interviews, sandwich generation literature and occupational therapy literature. In total, 31 working sandwich generation women and 42 occupational therapists completed the Q sort through either online or paper administration. The data were analysed using factor analysis with varimax rotation and were interpreted through collaboration with experts in the field. The findings revealed similarities between working sandwich generation women and occupational therapists, particularly in terms of advocating strategies related to sleep, rest and seeking practical assistance from support networks. Differences were also present, with working sandwich generation women viewpoints tending to emphasize strategies related to coping with a busy lifestyle attending to multiple responsibilities. In contrast, occupational therapy viewpoints prioritized strategies related to the occupational therapy process, such as goal setting, activity focused interventions, monitoring progress and facilitating sustainable outcomes.

  7. Behavior of the sandwich beam subjected to bending as a function of the core density

    Directory of Open Access Journals (Sweden)

    Nikolić Ružica R.

    2016-01-01

    Full Text Available The sandwich beam can be considered as the multi-layered structure with a symmetrical cross-section. In this paper is assumed that the structure is created by periodical repetition of a unit cell. The influence of its size on the beam’s static behavior in bending was analyzed. The variation of the unit cells number affects the size of the cell, so the static analysis was performed – the flexural stiffness and the beam’s deflection were determined as functions of the unit cells number. The two configurations of the sandwich beams were considered: the beam with the constant cross-section along its length and the beam with the periodically variable cross-section. The graphs of the beam’s flexural stiffness and deflection variations in terms of the unit cells number were obtained. It was concluded that after a certain number of the cells, the core’s density does not further influence the behavior of the sandwich beam, under the given loading conditions. The conclusion from comparison of the two configurations is that the sandwich beam with the variable cross-section behaves somewhat better than the beam with the constant cross-section. The FEM analysis has verified all the conclusions from the analytical solution about the sandwich beams behavior when subjected to bending.

  8. Free vibration analysis of simply supported sandwich beams with lattice truss core

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Jia, E-mail: jiajia_smile@163.com [Center for Composite Materials and Structures, Harbin Institute of Technology, P.O. Box 3011, Science Park of HIT, No. 2 Yi-Kuang Street, Harbin 150080 (China); Ma, Li, E-mail: mali@hit.edu.cn [Center for Composite Materials and Structures, Harbin Institute of Technology, P.O. Box 3011, Science Park of HIT, No. 2 Yi-Kuang Street, Harbin 150080 (China); Wu, Lin-Zhi, E-mail: wlz@hit.edu.cn [Center for Composite Materials and Structures, Harbin Institute of Technology, P.O. Box 3011, Science Park of HIT, No. 2 Yi-Kuang Street, Harbin 150080 (China)

    2012-11-20

    Free vibration of AISI 304 stainless steel sandwich beams with pyramidal truss core is investigated in the present paper. The lattice truss core is transformed to a continuous homogeneous material. Considering the deformation characteristics of the sandwich beam, the following assumptions are made: (1) the thickness of the sandwich beam remains constant during deformation; (2) for the thin face sheets, only bending deformation is considered, neglecting the effect of transverse shear deformation; (3) for the core, only shear deformation is considered as the core is too weak to provide a significant contribution to the bending stiffness of the sandwich beam. The shear stress is assumed to be constant along the thickness of the core. The governing equation of free vibration is derived from Hamilton's principle, and the natural frequencies are calculated under simply supported boundary conditions. Finally, numerical simulation is carried out to get the mode shapes and natural frequencies. Our results show that the theoretical solutions agree well with the numerical results. It indicates the present method would be useful for free vibration analysis of sandwich beams with lattice truss core.

  9. Structural Response of Polyethylene Foam-Based Sandwich Panels Subjected to Edgewise Compression

    Directory of Open Access Journals (Sweden)

    Luciano Lamberti

    2013-10-01

    Full Text Available This study analyzes the mechanical behavior of low density polyethylene foam core sandwich panels subjected to edgewise compression. In order to monitor panel response to buckling, strains generated in the facesheets and overall out-of-plane deformations are measured with strain gages and projection moiré, respectively. A finite element (FE model simulating the experimental test is developed. Numerical results are compared with moiré measurements. After having been validated against experimental evidence, the FE model is parameterized, and a trade study is carried out to investigate to what extent the structural response of the panel depends on the sandwich wall construction and facesheet/core interface defects. The projection moiré set-up utilized in this research is able to capture the sudden and very localized buckling phenomena occurring under edgewise compression of foam-based sandwich panels. Results of parametric FE analyses indicate that, if the total thickness of the sandwich wall is fixed, including thicker facesheets in the laminate yields a larger deflection of the panel that becomes more sensitive to buckling. Furthermore, the mechanical response of the foam sandwich panel is found to be rather insensitive to the level of waviness of core-facesheet interfaces.

  10. Network architecture design of an agile sensing system with sandwich wireless sensor nodes

    Science.gov (United States)

    Dorvash, S.; Li, X.; Pakzad, S.; Cheng, L.

    2012-04-01

    Wireless sensor network (WSN) is recently emerged as a powerful tool in the structural health monitoring (SHM). Due to the limitations of wireless channel capacity and the heavy data traffic, the control on the network is usually not real time. On the other hand, many SHM applications require quick response when unexpected events, such as earthquake, happen. Realizing the need to have an agile monitoring system, an approach, called sandwich node, was proposed. Sandwich is a design of complex sensor node where two Imote2 nodes are connected with each other to enhance the capabilities of the sensing units. The extra channel and processing power, added into the nodes, enable agile responses of the sensing network, particularly in interrupting the network and altering the undergoing tasks for burst events. This paper presents the design of a testbed for examination of the performance of wireless sandwich nodes in a network. The designed elements of the network are the software architecture of remote and local nodes, and the triggering strategies for coordinating the sensing units. The performance of the designed network is evaluated through its implementation in a monitoring test in the laboratory. For both original Imote2 and the sandwich node, the response time is estimated. The results show that the sandwich node is an efficient solution to the collision issue in existing interrupt approaches and the latency in dense wireless sensor networks.

  11. Restoration of cell polarity and bile excretion function of hepatocytes in sandwich-culture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xian-jie; WANG Ying; SUN Jia-bang; SONG Mao-min; QIAO Xin

    2007-01-01

    Objective:To investigate the nature of the restoration of cell polarity and bile excretion function in Sandwich-cultured hepatocytes.Methods:Freshly isolated hepatocytes from male Sprague-Dawley rats were cultured in a double layer collagen gel Sandwich configuration.Morphological changes were observed under a inverted microscope.The domain specific membrane associated protein DPP Ⅳ was tested by immunofluorescenee,and the bile excretion function was determined by using fluorescein diacetate.Hepatocytes cultured on a single layer of collagen gel were taken as control.Results:Adult rat hepatocytes cultured in a double layer collagen gel sandwich configuration regained its morphological and functional polarity and maintained polygonal morphology for at least 4 weeks.Immunofluorescence studies USing antibodies against DPP Ⅳ showed polarity restoration as early as 48 h.After cultured in the double layer collagen gel Sandwich configuration for 96 h the hepatocytes began to excrete bile;while hepatocytes cultured on a single layer collagen gel had no bile excretion.Conclusion:Hepatocytes cultured in a double layer collagen gel Sandwich configuration are able to regain their morphological and functional polarity givan certain conditions.Hepaotcyte culture is a useful tool for the study of polarity restoration.

  12. Development of indirect sandwich ELISA for determination of excretory-secretory antigens of Fasciola hepatica

    Directory of Open Access Journals (Sweden)

    Libertad Alzamora-Gonzales

    2016-05-01

    Full Text Available Fasciolosis is a cosmopolitan parasitosis medical-veterinary importance caused by Fasciola hepatica, which affects sheep, goats and cattle; and it affects man accidentally causing an epidemic-endemic infection difficult to diagnose. The aim was to develop an indirect sandwich ELISA with 3 antibodies for detecting excretory-secretory antigens of Fasciola hepatica (ESFh. For the development of indirect sandwich ELISA were used, as capture antibody, mouse polyclonal antibodies anti ESFh and polyclonal antibodies rabbit anti-ESFh as detection antibody, at the concentrations of 10 and 5 µg/mL respectively. The conjugate used was mouse monoclonal anti- total immunoglobulins rabbit linked to peroxidase (1/1000. Were analized 31 sheep fecal samples, and the results were compared with those obtained by direct coproparasitological examination (DC and counterimmunoelectrophoresis (CIEP. The detection limit obtained for indirect sandwich ELISA was 100 ng/mL. The test had a 100% sensitivity, 96.6% specificity, positive and negative predictive values of 50% and 96.6% respectively, in relation to DC test. Comparing with CIEP the specificity obtained for indirect sandwich ELISA was 93.5% and a negative predictive value of 100%. We concluded that indirect sandwich ELISA designed is able to detect metabolic antigens in ovine feces samples and can be used for Fasciola hepatica diagnosis.

  13. Sound transmission loss characteristics of sandwich panels with a truss lattice core.

    Science.gov (United States)

    Ehsan Moosavimehr, S; Srikantha Phani, A

    2017-04-01

    Sandwich panels are extensively used in constructional, naval, and aerospace structures due to the high stiffness and strength-to-weight ratios. In contrast, the sound transmission properties are adversely influenced by the low effective mass. Phase velocity matching of structural waves propagating within the panel and the incident pressure waves from the fluid medium leads to coincidence effects resulting in reduced impedance and high sound transmission. Truss-like lattice cores with porous microarchitecture and reduced inter panel connectivity offer the potential to satisfy the conflicting structural and vibroacoustic response requirements. This study combines Bloch-wave analysis and the finite element method to understand wave propagation and hence sound transmission in sandwich panels with a truss lattice core. Three dimensional coupled fluid-structure finite element simulations are conducted to compare the performance of a representative set of lattice core topologies. Potential advantages of sandwich structures with a lattice core are identified. The significance of partial band gaps is evident in the sound transmission loss characteristics of the panels studied. This work demonstrates that, even without optimization, significant enhancements in sound transmission loss performance can be achieved in truss lattice core sandwich panels compared to a traditional sandwich panel employing a honeycomb core under constant mass constraint.

  14. High-throughput screening techniques for rapid PEG-based precipitation of IgG4 mAb from clarified cell culture supernatant.

    Science.gov (United States)

    Knevelman, Carol; Davies, Jim; Allen, Lee; Titchener-Hooker, Nigel J

    2010-01-01

    Locating optimal protein precipitation conditions for complex biological feed materials is problematic. This article describes the application of a series of high-throughput platforms for the rapid identification and selection of conditions for the precipitation of an IgG(4) monoclonal antibody (mAb) from a complex feedstock using only microliter quantities of material. The approach uses 96-microwell filter plates combined with high-throughput analytical methods and a method for well volume determination for product quantification. The low material, time and resource requirements facilitated the use of a full factorial Design of Experiments (DoE) for the rapid investigation into how critical parameters impact the IgG(4) precipitation. To aid the DoE, a set of preliminary range-finding studies were conducted first. Data collected through this approach describing Polyethylene Glycol (PEG) precipitation of the IgG(4) as a function of mAb concentration, precipitant concentration, and pH are presented. Response surface diagrams were used to explore interactions between parameters and to inform selection of the most favorable conditions for maximum yield and purification. PEG concentrations required for maximum yield and purity were dependant on the IgG(4) concentration; however, concentrations of 14 to 20% w/v, pH 6.5, gave optimal levels of yield and purity. Application of the high-throughput approach enabled 1,155 conditions to be examined with less than 1 g of material. The level of insights gained over such a short time frame is indicative of the power of microwell experimentation in allowing the rapid identification of appropriate processing conditions for key bioprocess operations. Copyright 2009 American Institute of Chemical Engineers

  15. Production of different glycosylation variants of the tumour-targeting mAb H10 in Nicotiana benthamiana: influence on expression yield and antibody degradation.

    Science.gov (United States)

    Lombardi, Raffaele; Donini, Marcello; Villani, Maria Elena; Brunetti, Patrizia; Fujiyama, Kazuhito; Kajiura, Hiroyuki; Paul, Matthew; Ma, Julian K-C; Benvenuto, Eugenio

    2012-10-01

    We previously described the expression of a tumour-targeting antibody (mAb H10) in Nicotiana benthamiana by vacuum-agro-infiltration and the remarkable yields of highly pure protein achieved. The objective of the present work was to investigate different strategies for transient overexpression of the mAb H10 in which glycan configuration was modulated and assess how these strategies affect the accumulation yield and stability of the antibody. To this aim, three procedures have been assayed: (1) Site-directed mutagenesis to abolish the glycosylation site; (2) endoplasmic reticulum retention (C-terminal SEKDEL fusion) to ensure predominantly high-mannose type glycans; and (3) expression in a N. benthamiana RNAi down-regulated line in which β1,2-xylosyltransferase and α1,3-fucosyltransferase gene expression is silenced. The three antibody variants (H10-Mut) (H10-SEKDEL) (H10(XylT/FucT)) were transiently expressed, purified and characterised for their glycosylation profile, expression/purification yield and antibody degradation pattern. Glycosylation analysis of H10(XylT/FucT) demonstrated the absence of plant complex-type sugars, while H10-SEKDEL, although substantially retained in the ER, revealed the presence of β1,2-xylose and α1,3-fucose residues, indicating a partial escape from the ER retrieval system. Antibody accumulation and purification yields were not enhanced by ER retention. All H10 antibody glyco-forms revealed greater degradation compared to the original, resulting mostly in the formation of Fab fragments. In the case of aglycosylated H10-Mut, more than 95% of the heavy chain was cleaved, confirming the pivotal role of the sugar moiety in protein stability. Identification of possible 'fragile' sites in the H10 antibody hinge region could be of general interest for the development of new strategies to reduce antibody degradation and increase the yield of intact IgGs in plants.

  16. Life-cycle and cost of goods assessment of fed-batch and perfusion-based manufacturing processes for mAbs.

    Science.gov (United States)

    Bunnak, Phumthep; Allmendinger, Richard; Ramasamy, Sri V; Lettieri, Paola; Titchener-Hooker, Nigel J

    2016-09-01

    Life-cycle assessment (LCA) is an environmental assessment tool that quantifies the environmental impact associated with a product or a process (e.g., water consumption, energy requirements, and solid waste generation). While LCA is a standard approach in many commercial industries, its application has not been exploited widely in the bioprocessing sector. To contribute toward the design of more cost-efficient, robust and environmentally-friendly manufacturing process for monoclonal antibodies (mAbs), a framework consisting of an LCA and economic analysis combined with a sensitivity analysis of manufacturing process parameters and a production scale-up study is presented. The efficiency of the framework is demonstrated using a comparative study of the two most commonly used upstream configurations for mAb manufacture, namely fed-batch (FB) and perfusion-based processes. Results obtained by the framework are presented using a range of visualization tools, and indicate that a standard perfusion process (with a pooling duration of 4 days) has similar cost of goods than a FB process but a larger environmental footprint because it consumed 35% more water, demanded 17% more energy, and emitted 17% more CO2 than the FB process. Water consumption was the most important impact category, especially when scaling-up the processes, as energy was required to produce process water and water-for-injection, while CO2 was emitted from energy generation. The sensitivity analysis revealed that the perfusion process can be made more environmentally-friendly than the FB process if the pooling duration is extended to 8 days. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1324-1335, 2016. © 2016 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

  17. Life‐cycle and cost of goods assessment of fed‐batch and perfusion‐based manufacturing processes for mAbs

    Science.gov (United States)

    Bunnak, Phumthep; Allmendinger, Richard; Ramasamy, Sri V.; Lettieri, Paola

    2016-01-01

    Life‐cycle assessment (LCA) is an environmental assessment tool that quantifies the environmental impact associated with a product or a process (e.g., water consumption, energy requirements, and solid waste generation). While LCA is a standard approach in many commercial industries, its application has not been exploited widely in the bioprocessing sector. To contribute toward the design of more cost‐efficient, robust and environmentally‐friendly manufacturing process for monoclonal antibodies (mAbs), a framework consisting of an LCA and economic analysis combined with a sensitivity analysis of manufacturing process parameters and a production scale‐up study is presented. The efficiency of the framework is demonstrated using a comparative study of the two most commonly used upstream configurations for mAb manufacture, namely fed‐batch (FB) and perfusion‐based processes. Results obtained by the framework are presented using a range of visualization tools, and indicate that a standard perfusion process (with a pooling duration of 4 days) has similar cost of goods than a FB process but a larger environmental footprint because it consumed 35% more water, demanded 17% more energy, and emitted 17% more CO2 than the FB process. Water consumption was the most important impact category, especially when scaling‐up the processes, as energy was required to produce process water and water‐for‐injection, while CO2 was emitted from energy generation. The sensitivity analysis revealed that the perfusion process can be made more environmentally‐friendly than the FB process if the pooling duration is extended to 8 days. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1324–1335, 2016 PMID:27390260

  18. Aeroallergen analyses and their clinical relevance. I. Immunochemical quantification of allergens by RAST-inhibition, Mab-ELISA, basophil histamine release, and counter current immuno electrophoresis.

    Science.gov (United States)

    Johnsen, C R; Abrahamsen, L; Stahl Skov, P; Johansen, N; Poulsen, L K

    1991-10-01

    The aim was to compare IgE and IgG4 RAST-inhibition assay (RI), monoclonal antibody ELISA (Mab-ELISA), counter current immuno electrophoresis (CCIE) and histamine release from basophil leukocytes (HR) for allergen quantification with special reference to aeroallergen detection. As components of indoor aeroallergens, cat, dog, and Derm. pter. allergen extracts were selected for the experiments. To evaluate unspecific interference, these allergens were compared mutually and with Cladosporium herbarum. Allergen extracts in varying dilutions were mixed with crushed glass fibre filter materials, eluted, recovered by centrifugation, and allergen concentration quantified by the assays. Equal sensitivity was found for both IgE- and IgG4-RI assaying cat allergen (in the range 5-50 SQ-U/ml) and dog allergen (in the range 10(2)-10(3) SQ-U/ml). The IgG4-RI assaying Derm. pter. was more sensitive (50 SQ-U/ml) than IgE-RI (2*10(3) SQ-U/ml). The ranges of allergen detection limits for the Mab-ELISA were equal for cat and Derm. pter. (10-10(2) SQ-U/ml). The range of allergen detection limits for CCIE, assaying dog were 10(4)-10(5) SQ-U/ml. The ranges of allergen detection limits for HR were equal for cat and Derm. pter. (10-10(2) SQ-U/ml), and 10(2)-10(3) SQ-U/ML for dog. Because of cross-reactivity, a minor degree of interference was observed in the IgE-RI and the HR test for the highest concentration of cat and dog allergens.

  19. Ageing tests study on wood-based sandwich panels

    Directory of Open Access Journals (Sweden)

    Mateo, Raquel

    2011-12-01

    Full Text Available Composite lightweight wood panels are being increasingly used in construction in Spain. Their growing use should be accompanied by necessary guarantees based on studies of their properties. As it is prescriptive and in addition to others tests, in the present work is examinated the durability of these panels when exposed to the climatic conditions, a characteristic of great importance for wood products, according to Guide ETAG 016, the current standard defining the ageing tests to be used. However, due to the use class of this material, there are indications that the testing outlined in this Guide is inappropriate for assessing the ageing of wood-based sandwich panels. Alternative tests are here proposed that recreate rather better the real conditions under which these products are used. Covering the samples in a waterproof sheeting permeable to the outward movement of water vapour, which is in fact used in the installation, provided the best procedure for testing these panels.

    Los paneles sándwich de madera son un producto de creciente aplicación en la edificación de nuestro país. Este ascendente uso del material debe estar acompañado de las garantías necesarias avaladas por un estudio previo de sus prestaciones. Como es preceptivo y entre otros, se evalúa su durabilidad frente a las condiciones climatológicas, clave en los productos derivados de la madera, acorde a la normativa actual definida con tal fin, la Guía ETAG 016. Sin embargo, debido a la clase de uso del material, se ha detectado que dicha normativa tal y como está concebida no es capaz de valorar su envejecimiento adecuadamente. En este trabajo se proponen ensayos alternativos al establecido tras exhaustivos análisis que recrean las condiciones reales de uso y más acordes a los productos de madera. Se concluye que la incorporación de una lámina impermeable pero permeable al vapor de agua hacia el exterior, como las utilizadas en el montaje, aportan el mejor

  20. Radiant heating tests of several liquid metal heat-pipe sandwich panels

    Science.gov (United States)

    Camarda, C. J.; Basiulis, A.

    1983-01-01

    Integral heat pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich construction, were conceived as a means of alleviating thermal stress problems in the Langley Scramjet Engine. Test panels which utilized two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and a liquid metal working fluid (either sodium or potassium) were tested by radiant heating at various heat load levels. The heat pipe panels reduced maximum temperature differences by 31 percent with sodium working fluid and 45 percent with potassium working fluid. Results indicate that a heat pipe sandwich panel is a potential, simple solution to the engine thermal stress problem. Other interesting applications of the concept include: cold plates for electronic component and circuit card cooling, radiators for large space platforms, low distortion large area structures (e.g., space antennas) and laser mirrors.