Micromechanical testing of SU-8 cantilevers

OpenAIRE

Hopcroft, M; Kramer, T; Kim, G; Takashima, K; Higo, Y; Moore, D; Brugger, J

2005-01-01

SU-8 is a photoplastic polymer with a wide range of possible applications in microtechnology. Cantilevers designed for atomic force microscopes were fabricated in SU-8. The mechanical properties of these cantilevers were investigated using two microscale testing techniques: contact surface profilometer beam deflection and static load deflection at a point on the beam using a specially designed test machine. The SU-8 Young's modulus value from the microscale test methods is approximately 2-3 GPa.

Broken SU(8) symmetry and the new particles

International Nuclear Information System (INIS)

Kramer, G.; Schiller, D.H.

1976-05-01

We study the mass spectra and wave functions for vector and pseudoscalar mesons in broken SU(8) (SU(8) is contained in SU(4)F * SU(2)J), where F stands for flavour and J for usual spin. The connection with the standard mass breaking in SU(4)F is worked out. We find that even in the presence of strong SU(8) breaking the ideal mixing scheme for the vector mesons can be approximately retained. For the pseudoscalar mesons the mixing of the singlet with the 63-plet representation of SU(8) turns out to be essential and stongly nonideal. (orig.) [de

Processing of thin SU-8 films

International Nuclear Information System (INIS)

Keller, Stephan; Blagoi, Gabriela; Lillemose, Michael; Haefliger, Daniel; Boisen, Anja

2008-01-01

This paper summarizes the results of the process optimization for SU-8 films with thicknesses ≤5 µm. The influence of soft-bake conditions, exposure dose and post-exposure-bake parameters on residual film stress, structural stability and lithographic resolution was investigated. Conventionally, the SU-8 is soft-baked after spin coating to remove the solvent. After the exposure, a post-exposure bake at a high temperature T PEB ≥ 90 °C is required to cross-link the resist. However, for thin SU-8 films this often results in cracking or delamination due to residual film stress. The approach of the process optimization is to keep a considerable amount of the solvent in the SU-8 before exposure to facilitate photo-acid diffusion and to increase the mobility of the monomers. The experiments demonstrate that a replacement of the soft-bake by a short solvent evaporation time at ambient temperature allows cross-linking of the thin SU-8 films even at a low T PEB = 50 °C. Fourier-transform infrared spectroscopy is used to confirm the increased cross-linking density. The low thermal stress due to the reduced T PEB and the improved structural stability result in crack-free structures and solve the issue of delamination. The knowledge of the influence of different processing parameters on the responses allows the design of optimized processes for thin SU-8 films depending on the specific application

On grand unified SU(8)sub(L)xSU(8)sub(R) model

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1980-01-01

A set of general prjnciples justifying the choice of the group SU(N)sub(L)xSU(N)sub(R) with N=8 as the grand unified symmetry group is considered. Accordjng to these principles the group SU(N)sub(L)xSU(N)sub(R) is one of the most natural unified groups. Namely this group is maximum symmetry group of kinetic term of the Lagrangian of one family, which conserves fermion number. A new principle has been introduced according to which one of the manifestations of extended conformal invariance at small distances is mirror doubling of set of fermions, which is necessary on the other hand for renormalizability of the given unified model

SU-8 Based Piezoresistive Mechanical Sensor

DEFF Research Database (Denmark)

Thaysen, Jacob; Yalcinkaya, Arda Deniz; Vestergaard, R.K.

2002-01-01

We present the first SU-8 based piezoresistive mechanical sensor. Conventionally, silicon has been used as a piezoresistive material due to its high gauge factor and thereby high sensitivity to strain changes in a sensor. By using the fact that SU-8 is much softer than silicon and that a gold...

Diffusion of water into SU-8 microcantilevers

DEFF Research Database (Denmark)

Liu, C.J.; Liu, Y.; Sokuler, M.

2010-01-01

We present a method to monitor the diffusion of liquid molecules in polymers. A microdrop of water is deposited by a piezoelectric drop generator onto the upper surface of a cantilever made of SU-8 based photoresist. In response, the cantilever bends in the opposite direction. We find...... sophisticated finite element model the diffusion coefficient of water in the SU-8 polymer can be determined quantitatively from the dynamics of cantilever bending....... that this bending is mainly caused by the diffusion of water into the cantilever and the consequent swelling of SU-8. Using a one-dimensional diffusion model and assuming a simple swelling law, we qualitatively model the bending of the cantilever during in and out diffusion of water in SU-8. With a more...

Functionalization of SU-8 photoresist surfaces with IgG proteins

International Nuclear Information System (INIS)

Blagoi, Gabriela; Keller, Stephan; Johansson, Alicia; Boisen, Anja; Dufva, Martin

2008-01-01

The negative epoxy-based photoresist SU-8 has a variety of applications within microelectromechanical systems (MEMS) and lab-on-a-chip systems. Here, several methods to functionalize SU-8 surfaces with IgG proteins were investigated. Fluorescent labeled proteins and fluorescent sandwich immunoassays were employed to characterize the binding efficiency of model proteins to bare SU-8 surface, SU-8 treated with cerium ammonium nitrate (CAN) etchant and CAN treated surfaces modified by aminosilanization. The highest binding capacity of antibodies was observed on bare SU-8. This explains why bare SU-8 in a functional fluorescent sandwich immunoassay detecting C-reactive protein (CRP) gave twice as high signal as compared with the other two surfaces. Immunoassays performed on bare SU-8 and CAN treated SU-8 resulted in detection limits of CRP of 30 and 80 ng/ml respectively which is sufficient for detecting CRP in clinical samples, where concentrations of 3-10 μg/ml are normal for healthy individuals. In conclusion, bare SU-8 and etched SU-8 can be modified with antibodies by a simple adsorption procedure which simplifies building lab-on-a-chip systems in SU-8. Additionally, we report the fabrication process and use of microwells created in a SU-8 layer with the same dimensions as a standard microscope glass slide that could fit into fluorescent scanners. The SU-8 microwells minimize the reagent consumption and are straightforward to handle compared to SU-8 coated microscope slides

Functionalization of SU-8 Photoresist Surfaces with IgG Proteins

DEFF Research Database (Denmark)

Blagoi, Gabriela; Keller, Stephan Urs; Johansson, Alicia

2008-01-01

immunoassays were employed to characterize the binding efficiency of model proteins to bare SU-8 surface, SU-8 treated with cerium ammonium nitrate (CAN) etchant and CAN treated surfaces modified by aminosilanization. The highest binding capacity of antibodies was observed on bare SU-8. This explains why bare...... SU-8 in a functional fluorescent sandwich immunoassay detecting C-reactive protein (CRP) gave twice as high signal as compared with the other two surfaces. Immunoassays performed on bare SU-8 and CAN treated SU-8 resulted in detection limits of CRP of 30 and 80 ng/ml respectively which is sufficient...... for detecting CRP in clinical samples, where concentrations of 3–10 μg/ml are normal for healthy individuals. In conclusion, bare SU-8 and etched SU-8 can be modified with antibodies by a simple adsorption procedure which simplifies building lab-on-a-chip systems in SU-8. Additionally, we report the fabrication...

MICROSTRUCTURING OF SU-8 RESIST FOR MEMS AND BIO-APPLICATIONS

OpenAIRE

Dey, P.K.; Pramanick, B.; RaviShankar, A.; Ganguly, P.; Das, S.

2017-01-01

Some studies on the fabrication of micro-needles, micro-pillers, and micro-channels using SU-8 negative photoresist for MEMS and bio-applications are reported. The SU-8 processing technology was standardized for the purpose. Micro-pillars were fabricated on SU-8 polymer by soft lithographic technique. Micro-needles were realized on SU-8 film utilizing lensing effect of the etched groove structure of the glass substrate. Micro-channel was fabricated by molding of PDMS polymer on patterned SU-8...

Innovative SU-8 Lithography Techniques and Their Applications

Directory of Open Access Journals (Sweden)

Jeong Bong Lee

2014-12-01

Full Text Available SU-8 has been widely used in a variety of applications for creating structures in micro-scale as well as sub-micron scales for more than 15 years. One of the most common structures made of SU-8 is tall (up to millimeters high-aspect-ratio (up to 100:1 3D microstructure, which is far better than that made of any other photoresists. There has been a great deal of efforts in developing innovative unconventional lithography techniques to fully utilize the thick high aspect ratio nature of the SU-8 photoresist. Those unconventional lithography techniques include inclined ultraviolet (UV exposure, back-side UV exposure, drawing lithography, and moving-mask UV lithography. In addition, since SU-8 is a negative-tone photoresist, it has been a popular choice of material for multiple-photon interference lithography for the periodic structure in scales down to deep sub-microns such as photonic crystals. These innovative lithography techniques for SU-8 have led to a lot of unprecedented capabilities for creating unique micro- and nano-structures. This paper reviews such innovative lithography techniques developed in the past 15 years or so.

SU-8 photoresist and SU-8 based nanocomposites for broadband acoustical matching at 1 GHz

Energy Technology Data Exchange (ETDEWEB)

Ndieguene, A; Campistron, P; Carlier, J; Wang, S; Callens-Debavelaere, D; Nongaillard, B, E-mail: Assane.Ndieguene@meletu.univ-valenciennes.f [Univ Lille Nord de France, F-59000 Lille (France)

2009-11-01

So as to integrate acoustic functions in BioMEMS using 1 GHz ZnO transducers deposited on silicon substrates, acoustic waves propagation through the silicon substrate and its transmission in water needs to be maximized (the insertion losses at the Si / water interface are about 6dB). In the context of integration, it is interesting for mechanical impedance matching to use photosensitive materials such as SU-8 so that patterns may be obtained. Nanocomposite materials based on SU-8 mixed with nanoparticles having adequate impedances were fabricated. These new materials are characterized in terms of their acoustic velocity, impedance and attenuation. For this, the nanocomposite layers are deposited on the substrate by spin coating to obtain a thickness of about 10 {mu}m, in order to separate acoustic echoes from the material (even if {lambda}/4 layer thickness is lower than 1 {mu}m). The insertion losses of the device immersed in water can be simulated as a function of frequency for a given reflection coefficient between the silicon substrate and the photoresist. The characteristics of some nanocomposites made with SU-8 and various concentrations of nanoparticles like Ti0{sub 2}, SrTiO{sub 3} or W have been determined.

Fabrication of raised and inverted SU8 polymer waveguides

Science.gov (United States)

Holland, Anthony S.; Mitchell, Arnan; Balkunje, Vishal S.; Austin, Mike W.; Raghunathan, Mukund K.

2005-01-01

Polymer films with high optical transmission have been investigated for making optical devices for several years. SU8 photoresist and optical adhesives have been investigated for use as thin films for optical devices, not what they were originally designed for. Optical adhesives are typically a one component thermoset polymer and are convenient to use for making thin film optical devices such as waveguides. They are prepared in minutes as thin films unlike SU8, which has to be carefully thermally cured over several hours for optimum results. However SU8 can be accurately patterned to form the geometry of structures required for single mode optical waveguides. SU8 in combination with the lower refractive index optical adhesive films such as UV15 from Master Bond are used to form single and multi mode waveguides. SU8 is photopatternable but we have also used dry etching of the SU8 layer or the other polymer layers e.g. UV15 to form the ribs, ridges or trenches required to guide single modes of light. Optical waveguides were also fabricated using only optical adhesives of different refractive indices. The resolution obtainable is poorer than with SU8 and hence multi mode waveguides are obtained. Loss measurements have been obtained for waveguides of different geometries and material combinations. The process for making polymer waveguides is demonstrated for making large multi mode waveguides and microfluidic channels by scaling the process up in size.

Functionalized SU-8 patterned with X-ray Lithography

DEFF Research Database (Denmark)

Balslev, Søren; Romanato, F.

2005-01-01

spontaneous emission light source that couples out light normal to the chip plane. In addition we examine the influence of the x-ray irradiation on the fluorescence of thin films of dye doped SU-8. The dye embedded in the SU-8 is optically excited during, characterization by an external light source tuned......In this work we demonstrate the feasibility of x-ray lithography on SU-8 photoresist doped with the laser dye Rhodamine 6G, while retaining the photoactive properties of the embedded dye. Two kinds of structures are fabricated via soft x-ray lithography and characterized: a laser and in amplified...

Chemical synthesis on SU-8

DEFF Research Database (Denmark)

Qvortrup, Katrine; Taveras, Kennedy; Thastrup, Ole

2011-01-01

In this paper we describe a highly effective surface modification of SU-8 microparticles, the attachment of appropriate linkers for solid-supported synthesis, and the successful chemical modification of these particles via controlled multi-step organic synthesis leading to molecules attached...

Symmetry hierarchies and radiative corrections in the grand unified model SU(8)/sub L/ x SU(8)/sub R/

International Nuclear Information System (INIS)

Pirogov, Y.F.

1982-01-01

In the SU(8)/sub L/ x SU(8)/sub R/ model of precocious chiral unification, radiative corrections for the effective parameters sin 2 theta/sub W/(μ) and α(μ) are calculated in the one-loop approximation, neglecting contributions of the Higgs fields, and the unification mass M 8 is determined in the presence of a hierarchy of intermediate symmetries. It is shown that a natural hierarchy exists which leads to a decrease in sin 2 theta/sub W/(M/sub W/L) down to the value sin 2 theta/sub W/ = (1/5)--(1/4) together with a decrease in M 8 down to M 8 = 10 6 --10 7 GeV in comparison with the values in the absence of a hierarchy

On symmetry hierarchy and radiative corrections in the grand unified model SU(8)sub(L)xSU(8)sub(R)

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1982-01-01

In the model of precocious chiral unification SU(8)sub(L)xSU(8)sub(R) radiative corrections are calculated for the effective parameters sin 2 thetaw(μ) and α(μ) and the unification mass M 8 is determifed in presence of a hierarchy of intermediate symmetries. The one-loop approximation is used and contributions from the Higgs fields are neglected. It is shown that a natural hierarchy exists leading to a decrease of sinsup(2)thetasub(w)(Msub(wsub(L))) up to sinsup(2)thetasub(w)=1/5-1/4 together with a decrease of M 8 up to M 8 =10 6 -10 7 GeV, as compared with the magnitudes without the hierarchy [ru

Novel SU-8 based vacuum wafer-level packaging for MEMS devices

DEFF Research Database (Denmark)

Murillo, Gonzalo; Davis, Zachary James; Keller, Stephan Urs

2010-01-01

This work presents a simple and low-cost SU-8 based wafer-level vacuum packaging method which is CMOS and MEMS compatible. Different approaches have been investigated by taking advantage of the properties of SU-8, such as chemical resistance, optical transparence, mechanical reliability and versa......This work presents a simple and low-cost SU-8 based wafer-level vacuum packaging method which is CMOS and MEMS compatible. Different approaches have been investigated by taking advantage of the properties of SU-8, such as chemical resistance, optical transparence, mechanical reliability...

SU-8 cantilever chip interconnection

DEFF Research Database (Denmark)

Johansson, Alicia Charlotte; Janting, Jakob; Schultz, Peter

2006-01-01

The polymer SU-8 is becoming widely used for all kinds of micromechanical and microfluidic devices, not only as a photoresist but also as the constitutional material of the devices. Many of these polymeric devices need to include a microfluidic system as well as electrical connection from the ele...

SU-8 negative photoresist for optical mask manufacturing

Science.gov (United States)

Bogdanov, Alexei L.

2000-06-01

The requirements for better control, linearity, and uniformity of critical dimension (CD) on photomasks in fabrication of 180 and 150 nm generation devices result in increasing demand for thinner, more etching durable, and more sensitive e-beam resists. Novolac based resists with chemical amplification have been a choice for their sensitivity and stability during etching. However, difficult CD control due to the acid catalyzer diffusion and quite narrow post exposure bake (PEB) process window are some of the major drawbacks of these resists. SU-8 is recently introduced to the market negative photoresist. High sensitivity, fairly good adhesion properties, and relatively simple processing of SU-8 make it a good substitution for novolac based chemically amplified negative e-beam resists in optical mask manufacturing. The replacement of traditional chemically amplified resists by SU- 8 can increase the process latitude and reduce resist costs. Among the obvious drawbacks of SU-8 are the use of solvent- based developer and demand of oxygen plasma for resist removal. In this paper the use of SU-8 for optical mask manufacturing is reported. All steps of resist film preparation, exposure and development are paid a share of attention. Possibilities to use reactive ion etching (RIE) with oxygen in order to increase resist mask contrast are discussed. Special exposure strategy (pattern outlining) was employed to further improve the edge definition. The resist PEB temperature and time were studied to estimate their weight in overall CD control performance. Specially designed test patterns with 0.25 micrometer design rule could be firmly transferred into a chromium layer both by wet etching and ion milling. Influence of exposure dose variation on the pattern CD change was studied.

SU-8 Photolithography as a Toolbox for Carbon MEMS

Directory of Open Access Journals (Sweden)

Rodrigo Martinez-Duarte

2014-09-01

Full Text Available The use of SU-8 as precursor for glass-like carbon, or glassy carbon, is presented here. SU-8 carbonizes when subject to high temperature under inert atmosphere. Although epoxy-based precursors can be patterned in a variety of ways, photolithography is chosen due to its resolution and reproducibility. Here, a number of improvements to traditional photolithography are introduced to increase the versatility of the process. The shrinkage of SU-8 during carbonization is then detailed as one of the guidelines necessary to design carbon patterns. A couple of applications—(1 carbon-electrode dielectrophoresis for bioparticle manipulation; and (2 the use of carbon structures as micro-molds are also presented.

Investigation of the bond strength between the photo-sensitive polymer SU-8 and gold

DEFF Research Database (Denmark)

Nordström, Maria; Johansson, Alicia; Sánchez Noguerón, E.

2005-01-01

adhesion promotors between the SU-8 and Au; (ii) the influence of the processing sequence, keeping either Au or SU-8 as the bottom layer; (iii) the importance of the UV exposure dosage of the SU-8. For comparison, also the bond strength between SU-8 and other materials was measured. For SU-8 and Au without...

Development of untethered SU-8 polymer scratch drive microrobots

KAUST Repository

Valencia Garcia, Manuel; Atallah, Tarek Nabil; Castro, David; Conchouso Gonzalez, David; Al Dosari, Mishari Ibraheem; Hammad, Rafat; Al Rawashdeh, Ehab Jamal; Zaher, Amir Omar; Kosel, Jü rgen; Foulds, Ian G.

2011-01-01

This paper presents the design, simulation, fabrication and testing of novel, untethered SU-8 polymer microrobots based on scratch drive actuators (SDAs). The design consists of two 100×120×10μm linked SDAs, individually operated close to their resonant frequencies. The resonant frequency and deflection behavior of an individual SDA can be controlled by its shape, thickness, and stiffening design features. As a result, paired SDAs can be actuated individually or simultaneously by a multifrequency driving signal, allowing for two-dimensional displacement. The fabrication process uses SU-8 as structural material and PMGI as sacrificial material. The SU-8 provides a flexible material for the SDA's plates as well as the bushing. Finally, a Cr/Au layer is blanket deposited to provide electrical conductivity.

Immunosensing by luminescence reduction in surface-modified microstructured SU-8

Energy Technology Data Exchange (ETDEWEB)

Eravuchira, Pinkie Jacob; Baranowska, Malgorzata; Eckstein, Chris [Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira i Virgili, Avda. Països Catalans 26, Tarragona 43007 (Spain); Díaz, Francesc [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcelí Domingo s/n, Tarragona 43007 (Spain); Llobet, Eduard; Marsal, Lluis F. [Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira i Virgili, Avda. Països Catalans 26, Tarragona 43007 (Spain); Ferré-Borrull, Josep, E-mail: josep.ferre@urv.cat [Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira i Virgili, Avda. Països Catalans 26, Tarragona 43007 (Spain)

2017-01-15

Highlights: • The reduction of photoluminescence of SU-8 upon surface modification is reported. • Micropillar structuring of SU-8 surface results in an increased photoluminescence reduction rate (10% glass, 15% silicon). • Photoluminescence reduction rate can be a transduction parameter for the detection of antibody-antigen binding events. • The proposed sensing mechanism can be used to quantify small concentrations of antibody. • Lower limit of detection (LOD) of 28 μg/ml on silicon substrates and 42 μg/ml on glass substrates was achieved. - Abstract: SU-8, an epoxy based negative photoresist is extensively used as a structural material for the fabrication of microelectro-mechanical systems and in microelectronics technology. However, the possible applications of SU-8 for biosensing have not been explored much, mainly because of the photoluminescence SU-8 possesses in the near-UV and visible wavelength ranges which hinders fluorescent labelling of biorecognition events. In this study we demonstrate that photoluminescence of SU-8 can be employed itself as a sensing transduction parameter to produce a tool for immunosensing: the photoluminescence shows a systematic reduction upon modification of its surface chemistry, and in particular upon attachment of an antigen-antibody (aIgG-IgG) pair. We investigate the relation of the amount of reduction of photoluminescence on planar and microstructured surfaces, and we show that microstructuring leads to a higher reduction than a planar surface. Furthermore, we evaluated the dependence of photoluminescence reduction as a function of analyte concentration to prove that this magnitude can be applied to immunosensing.

Surface Modification of Photoresist SU-8 for Low Autofluorescence and Bioanalytical Applications

DEFF Research Database (Denmark)

Cao, Cuong; Birtwell, Sam W.; Høgberg, Jonas

2011-01-01

This paper reports a surface modification of epoxy-based negative photoresist SU-8 for reducing its autofluorescence while enhancing its biofunctionality. By covalently depositing a thin layer of 20 nm Au nanoparticles (AuNPs) onto the SU-8 surface, we found that the AuNPs-coated SU-8 surface...... is much less fluorescent than the untreated SU-8. Moreover, DNA probes can easily be immobilized on the Au surface and are thermally stable over a wide range of temperature. These improvements will benefit bioanalytical applications such as DNA hybridization and solid-phase PCR (SP-PCR)....

Photochemical modification and patterning of SU-8 using Anthraquinone photolinkers

DEFF Research Database (Denmark)

Blagoi, Gabriela; Keller, Stephan Urs; Persson, Karl Fredrik

2008-01-01

-dimensional patterns on a Novolac A derivative polymer (SU-8) and, subsequently, their functionalization with biomolecules. Anthraquinone (AQ) derivatives are used to chemically modify and pattern SU-8 surfaces. Features as small as 20 μm are obtained when using uncollimated light. The X−Y spatial resolution...

SU-8 Composite Based “Lube-tape” for a Wide Range of Tribological Applications

Directory of Open Access Journals (Sweden)

Prabakaran Saravanan

2014-05-01

Full Text Available In a previous work, we have developed a perflouropolyether (PFPE lubricant droplet-filled SU-8 composite which promotes bonding between the molecules of SU-8 and PFPE and provides excellent boundary lubrication. The SU-8 + PFPE composite has enhanced the wear durability of SU-8 by more than four orders of magnitude. In this work, the same SU-8 + PFPE composite was used to fabricate a stand-alone laminate film called “Lube-tape”. It has integrated two layers of approximately 90 microns thickness each; the top layer is made of SU-8 + PFPE composite and the bottom layer of pristine SU-8. Thus, a single tape can have drastically contrasting high friction and low friction properties on its two surfaces. The composite side has the initial coefficient of friction ~7 times lower and the wear life more than four orders of magnitude than those of the pristine SU-8 side. This lube tape can be used on any load bearing surface to improve the tribological performance by simply pasting the pristine SU-8 side onto the substrate.

Development of untethered SU-8 polymer scratch drive microrobots

KAUST Repository

Valencia Garcia, Manuel

2011-01-01

This paper presents the design, simulation, fabrication and testing of novel, untethered SU-8 polymer microrobots based on scratch drive actuators (SDAs). The design consists of two 100×120×10μm linked SDAs, individually operated close to their resonant frequencies. The resonant frequency and deflection behavior of an individual SDA can be controlled by its shape, thickness, and stiffening design features. As a result, paired SDAs can be actuated individually or simultaneously by a multifrequency driving signal, allowing for two-dimensional displacement. The fabrication process uses SU-8 as structural material and PMGI as sacrificial material. The SU-8 provides a flexible material for the SDA\\'s plates as well as the bushing. Finally, a Cr/Au layer is blanket deposited to provide electrical conductivity.

Effects of temperature on mechanical properties of SU-8 photoresist material

Energy Technology Data Exchange (ETDEWEB)

Chung, Soon Wan; Park, Seung Bae [State University of New York, New York (United States)

2013-09-15

A representative fabrication processing of SU-8 photoresist, Ultraviolet (UV) lithography is usually composed of spin coat, soft bake, UV exposure, post exposure bake (PEB), development and optional hard bake, etc. The exposed region of SU-8 is crosslinked during the PEB process and its physical properties highly depend on UV exposure and PEB condition. This work was initiated to investigate if thermal baking after fabrication can affect the mechanical properties of SU-8 photoresist material because SU-8 is trying to be used as a structural material for MEMS operated at high temperature. Since a temperature of 95 .deg. C is normally recommended for PEB process, elevated temperatures up to 200 .deg. C were considered for the optional hard bake process. The viscoelastic material properties were measured by dynamic mechanical analyses (DMA). Also, pulling tests were performed to obtain Young's modulus and Poisson's ratio as a function of strain rate in a wide temperature range. From this study, the effects of temperature on the elastic and viscoelastic material properties of SU-8 were obtained.

Effects of temperature on mechanical properties of SU-8 photoresist material

International Nuclear Information System (INIS)

Chung, Soon Wan; Park, Seung Bae

2013-01-01

A representative fabrication processing of SU-8 photoresist, Ultraviolet (UV) lithography is usually composed of spin coat, soft bake, UV exposure, post exposure bake (PEB), development and optional hard bake, etc. The exposed region of SU-8 is crosslinked during the PEB process and its physical properties highly depend on UV exposure and PEB condition. This work was initiated to investigate if thermal baking after fabrication can affect the mechanical properties of SU-8 photoresist material because SU-8 is trying to be used as a structural material for MEMS operated at high temperature. Since a temperature of 95 .deg. C is normally recommended for PEB process, elevated temperatures up to 200 .deg. C were considered for the optional hard bake process. The viscoelastic material properties were measured by dynamic mechanical analyses (DMA). Also, pulling tests were performed to obtain Young's modulus and Poisson's ratio as a function of strain rate in a wide temperature range. From this study, the effects of temperature on the elastic and viscoelastic material properties of SU-8 were obtained.

Gold Nanoparticles-Coated SU-8 for Sensitive Fluorescence-Based Detections of DNA

DEFF Research Database (Denmark)

Cao, Cuong; Birtwell, Sam W.; Høgberg, Jonas

2012-01-01

SU-8 epoxy-based negative photoresist has been extensively employed as a structural material for fabrication of numerous biological microelectro-mechanical systems (Bio-MEMS) or lab-on-a-chip (LOC) devices. However, SU-8 has a high autofluorescence level that limits sensitivity of microdevices...... for various Bio-MEMs and LOC devices that use SU-8 as a structural material....

Investigation of the bond strength between the photo-sensitive polymer SU-8 and Au

DEFF Research Database (Denmark)

Nordstrom, Maria; Johansson, Alicia; Sanches-Noguerón, E.

2004-01-01

promotors between the SU-8 and Au (ii) the effect of the processing sequence, either keeping SU-8 as bottum layer or Au (iii) varying the UV exposure dosage of the SU-8. For comparison, also the bond strength between SU-8 and other materials was measured. We report on bond strength of 4.8 +/- 1.2 MPa...

SU-8 Guiding Layer for Love Wave Devices

Directory of Open Access Journals (Sweden)

Michael I. Newton

2007-11-01

Full Text Available SU-8 is a technologically important photoresist used extensively for thefabrication of microfluidics and MEMS, allowing high aspect ratio structures to beproduced. In this work we report the use of SU-8 as a Love wave sensor guiding layerwhich allows the possibility of integrating a guiding layer with flow cell during fabrication.Devices were fabricated on ST-cut quartz substrates with a single-single finger design suchthat a surface skimming bulk wave (SSBW at 97.4 MHz was excited. SU-8 polymer layerswere successively built up by spin coating and spectra recorded at each stage; showing afrequency decrease with increasing guiding layer thickness. The insertion loss andfrequency dependence as a function of guiding layer thickness was investigated over thefirst Love wave mode. Mass loading sensitivity of the resultant Love wave devices wasinvestigated by deposition of multiple gold layers. Liquid sensing using these devices wasalso demonstrated; water-glycerol mixtures were used to demonstrate sensing of density-viscosity and the physical adsorption and removal of protein was also assessed usingalbumin and fibrinogen as model proteins.

Effects of design geometry on SU8 polymer waveguides

Science.gov (United States)

Holland, Anthony S.; Balkunje, Vishal S.; Mitchell, Arnan; Austin, Michael W.; Raghunathan, Mukund K.; Kostovski, Gorgi

2005-02-01

The spin-on photoresist SU8 from MicroChem has a relatively high refractive index (n=1.57 at 1550nm) compared with other polymers. It is stable and has high optical transmission at optical communication wavelengths. In this paper we study rib waveguides fabricated using SU8 as the core layer and thermoset polymers UV15 (n=1.50 at 1550nm) from Master Bond and NOA61 (n=1.54 at 1550nm) from Gentec as the cladding layers. The rib height is varied from 0.3 to 1.7μm high. This is part of the SU8 layer sandwiched between the cladding layers. The waveguides are tested to determine the effects of varying this geometry for single mode optical transmission. The lengths of the waveguides were 1.5 cm to 5 cm.

A Review on Surface Stress-Based Miniaturized Piezoresistive SU-8 Polymeric Cantilever Sensors

Science.gov (United States)

Mathew, Ribu; Ravi Sankar, A.

2018-06-01

In the last decade, microelectromechanical systems (MEMS) SU-8 polymeric cantilevers with piezoresistive readout combined with the advances in molecular recognition techniques have found versatile applications, especially in the field of chemical and biological sensing. Compared to conventional solid-state semiconductor-based piezoresistive cantilever sensors, SU-8 polymeric cantilevers have advantages in terms of better sensitivity along with reduced material and fabrication cost. In recent times, numerous researchers have investigated their potential as a sensing platform due to high performance-to-cost ratio of SU-8 polymer-based cantilever sensors. In this article, we critically review the design, fabrication, and performance aspects of surface stress-based piezoresistive SU-8 polymeric cantilever sensors. The evolution of surface stress-based piezoresistive cantilever sensors from solid-state semiconductor materials to polymers, especially SU-8 polymer, is discussed in detail. Theoretical principles of surface stress generation and their application in cantilever sensing technology are also devised. Variants of SU-8 polymeric cantilevers with different composition of materials in cantilever stacks are explained. Furthermore, the interdependence of the material selection, geometrical design parameters, and fabrication process of piezoresistive SU-8 polymeric cantilever sensors and their cumulative impact on the sensor response are also explained in detail. In addition to the design-, fabrication-, and performance-related factors, this article also describes various challenges in engineering SU-8 polymeric cantilevers as a universal sensing platform such as temperature and moisture vulnerability. This review article would serve as a guideline for researchers to understand specifics and functionality of surface stress-based piezoresistive SU-8 cantilever sensors.[Figure not available: see fulltext.

Investigation on the mechanism of nitrogen plasma modified PDMS bonding with SU-8

Energy Technology Data Exchange (ETDEWEB)

Yang, Chengxin; Yuan, Yong J., E-mail: yongyuan@swjtu.edu.cn

2016-02-28

Graphical abstract: - Highlights: • Different nitrogen plasma processes modified PDMS bonding with SU-8 had been studied. • The effect of nitrogen plasma modification would produce the best result and the recovery of PDMS hydrophobicity could be delayed. - Abstract: Polydimethylsiloxane (PDMS) and SU-8 are both widely used for microfluidic system. However, it is difficult to permanently seal SU-8 microfluidic channels using PDMS with conventional methods. Previous efforts of combining these two materials mainly employed oxygen plasma modified PDMS. The nitrogen plasma modification of PDMS bonding with SU-8 is rarely studied in recent years. In this work, the mechanism of nitrogen plasma modified PDMS bonding with SU-8 was investigated. The fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle of a water droplet were used to analyze the nitrogen plasma modified surface and the hydrophilic stability of PDMS samples. Pull-off tests were used for estimating the bonding effect of interface between nitrogen plasma modified PDMS and SU-8.

SU-8 micropatterning for microfluidic droplet and microparticle focusing

International Nuclear Information System (INIS)

Debuisson, Damien; Senez, Vincent; Arscott, Steve

2011-01-01

We demonstrate micropatterned surfaces consisting of concentric circles and spirals which can focus an evaporating sessile droplet to a specific location on a surface. We also study the micropattern geometry to focus microparticles contained within the droplet. The micropatterned surfaces are fabricated using the photoresist SU-8. Our process enables the modification of the surface wetting via the formation of smooth trench-like defects in the SU-8 which define the micropatterns; the geometry of these micropatterns determines the droplet/microparticle focusing. It is clearly shown that the introduction of small gaps into the micropatterns promotes microparticle centring due to the modification of the depinning angle of the droplet. We also show that the use of spiral micropatterns promotes microparticle centring. Finally, microparticle focusing can be enhanced by modification of surface wetting via the addition of a thin fluorocarbon hydrophobic layer onto the SU-8

PDMS as a sacrificial substrate for SU-8-based biomedical and microfluidic applications

International Nuclear Information System (INIS)

Patel, Jasbir N; Kaminska, Bozena; Gray, Bonnie L; Gates, Byron D

2008-01-01

We describe a new fabrication process utilizing polydimethylesiloxane (PDMS) as a sacrificial substrate layer for fabricating free-standing SU-8-based biomedical and microfluidic devices. The PDMS-on-glass substrate permits SU-8 photo patterning and layer-to-layer bonding. We have developed a novel PDMS-based process which allows the SU-8 structures to be easily peeled off from the substrate after complete fabrication. As an example, a fully enclosed microfluidic chip has been successfully fabricated utilizing the presented new process. The enclosed microfluidic chip uses adhesive bonding technology and the SU-8 layers from 10 µm to 450 µm thick for fully enclosed microchannels. SU-8 layers as large as the glass substrate are successfully fabricated and peeled off from the PDMS layer as single continuous sheets. The fabrication results are supported by optical microscopy and profilometry. The peel-off force for the 120 µm thick SU-8-based chips is measured using a voice coil actuator (VCA). As an additional benefit the release step leaves the input and the output of the microchannels accessible to the outside world facilitating interconnecting to the external devices

SU-8 doped and encapsulated n-type graphene nanomesh with high air stability

Energy Technology Data Exchange (ETDEWEB)

Al-Mumen, Haider [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Electrical Engineering, University of Babylon, Babylon (Iraq); Dong, Lixin; Li, Wen, E-mail: wenli@egr.msu.edu [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)

2013-12-02

N-type doping of graphene with long-term chemical stability in air represents a significant challenge for practical application of graphene electronics. This paper reports a reversible doping method to achieve highly stable n-type graphene nanomeshes, in which the SU-8 photoresist simultaneously serves as an effective electron dopant and an excellent encapsulating layer. The chemically stable n-type characteristics of the SU-8 doped graphene were evaluated in air using their Raman spectra, electrical transport properties, and electronic band structures. The SU-8 doping does minimum damage to the hexagonal carbon lattice of graphene and is completely reversible by removing the uncrosslinked SU-8 resist.

MWP phase shifters integrated in PbS-SU8 waveguides.

Science.gov (United States)

Hervás, Javier; Suárez, Isaac; Pérez, Joaquín; Cantó, Pedro J Rodríguez; Abargues, Rafael; Martínez-Pastor, Juan P; Sales, Salvador; Capmany, José

2015-06-01

We present new kind of microwave phase shifters (MPS) based on dispersion of PbS colloidal quantum dots (QDs) in commercially available photoresist SU8 after a ligand exchange process. Ridge PbS-SU8 waveguides are implemented by integration of the nanocomposite in a silicon platform. When these waveguides are pumped at wavelengths below the band-gap of the PbS QDs, a phase shift in an optically conveyed (at 1550 nm) microwave signal is produced. The strong light confinement produced in the ridge waveguides allows an improvement of the phase shift as compared to the case of planar structures. Moreover, a novel ridge bilayer waveguide composed by a PbS-SU8 nanocomposite and a SU8 passive layer is proposed to decrease the propagation losses of the pump beam and in consequence to improve the microwave phase shift up to 36.5° at 25 GHz. Experimental results are reproduced by a theoretical model based on the slow light effect produced in a semiconductor waveguide due to the coherent population oscillations. The resulting device shows potential benefits respect to the current MPS technologies since it allows a fast tunability of the phase shift and a high level of integration due to its small size.

Novel SU-8/Ionic Liquid Composite for Tribological Coatings and MEMS

Directory of Open Access Journals (Sweden)

Leili Batooli

2015-05-01

Full Text Available Tribology of SU-8 polymer is increasingly relevant due to bursting use of this material in a variety of applications. This study is directed towards introduction and investigation of a novel self-lubricating composite of an ionic liquid (IL in SU-8. The new material can be utilized for fabrication of lubricating polymer coating with tunable surface properties or SU8-made elements for microelectromechanical systems (MEMS with enhanced tribological performance. It is shown that addition of IL drastically alters water affinity of the composite while UV patternability remains unmodified. A lower coefficient of friction and wear has been obtained for two investigated compositions with 4 and 10 wt % ionic liquid.

In situ SU-8 silver nanocomposites

Directory of Open Access Journals (Sweden)

Søren V. Fischer

2015-07-01

Full Text Available Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post-exposure soft bake steps at 95 °C. A further high-temperature treatment at 300 °C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ silver nanocomposite materials can be spin coated as homogeneous thin films and structured by using UV lithography. A resolution of 5 µm is achieved in the lithographic process. The UV exposure time is found to be independent of the nanoparticle concentration. The fabricated silver nanocomposites exhibit high plasmonic responses suitable for the development of new optoelectronic and optical sensing devices.

A Simple Hydrophilic Treatment of SU-8 Surfaces for Cell Culturing and Cell Patterning

DEFF Research Database (Denmark)

Wang, Zhenyu; Stangegaard, Michael; Dufva, Hans Martin

2005-01-01

SU-8, an epoxy-based photoresist, widely used in constitution different mTAS systems, is incompatible with mammalian cell adhesion and culture in its native form. Here, we demonstrate a simple, cheap and robust two-step method to render a SU-8 surface hydrophilic and compatible with cell culture........ The contact angle of SU-8 surface was significantly reduced from 90° to 25° after the surface modification. The treated SU-8 surfaces provided a cell culture environment that was comparable with cell culture flask surface in terms of generation time and morphology....

SU-8 as a Material for Microfabricated Particle Physics Detectors

CERN Document Server

Maoddi, Pietro; Jiguet, Sebastien; Renaud, Philippe

2014-01-01

Several recent detector te chnologies developed for particle physics applications are based on microfabricated structures. Dete ctors built with this approach generally exhibit the overall best performance in te rms of spatial and time resolution. Many properties of the SU-8 photoepoxy make it suitable for the manufacturing of microstructured particle detectors. This arti cle aims to review some emerging detector technologies making use of SU-8 microstructu ring, namely micropatte rn gaseous detectors and microfluidic scintillation detectors. Th e general working principle and main process steps for the fabrication of each device are reported, with a focus on the advantages brought to the device functionality by the us e of SU-8. A novel process based on multiple bonding steps for the fabrication of thin multila yer microfluidic scin tillation detectors developed by the authors is presented. Finally, a brief overview of the applications for the discussed devices is given.

Fabrication of thin SU-8 cantilevers: initial bending, release and time stability

DEFF Research Database (Denmark)

Keller, Stephan Urs; Haefliger, D.; Boisen, Anja

2010-01-01

SU-8 cantilevers with a thickness of 2 mu m were fabricated using a dry release method and two steps of SU-8 photolithography. The processing of the thin SU-8 film defining the cantilevers was experimentally optimized to achieve low initial bending due to residual stress gradients. In parallel......, the rotational deformation at the clamping point allowed a qualitative assessment of the device release from the fluorocarbon-coated substrate. The change of these parameters during several months of storage at ambient temperature was investigated in detail. The introduction of a long hard bake in an oven after...... development of the thin SU-8 film resulted in reduced cantilever bending due to removal of residual stress gradients. Further, improved time-stability of the devices was achieved due to the enhanced cross-linking of the polymer. A post-exposure bake at a temperature T-PEB = 50 degrees C followed by a hard...

Plasma etching of polymers like SU8 and BCB

Science.gov (United States)

Mischke, Helge; Gruetzner, Gabi; Shaw, Mark

2003-01-01

Polymers with high viscosity, like SU8 and BCB, play a dominant role in MEMS application. Their behavior in a well defined etching plasma environment in a RIE mode was investigated. The 40.68 MHz driven bottom electrode generates higher etch rates combined with much lower bias voltages by a factor of ten or a higher efficiency of the plasma with lower damaging of the probe material. The goal was to obtain a well-defined process for the removal and structuring of SU8 and BCB using fluorine/oxygen chemistry, defined using variables like electron density and collision rate. The plasma parameters are measured and varied using a production proven technology called SEERS (Self Excited Electron Resonance Spectroscopy). Depending on application and on Polymer several metals are possible (e.g., gold, aluminum). The characteristic of SU8 and BCB was examined in the case of patterning by dry etching in a CF4/O2 chemistry. Etch profile and etch rate correlate surprisingly well with plasma parameters like electron density and electron collision rate, thus allowing to define to adjust etch structure in situ with the help of plasma parameters.

SU-8 micro Coriolis mass flow sensor

NARCIS (Netherlands)

Monge, Rosa; Groenesteijn, Jarno; Alveringh, Dennis; Wiegerink, Remco J.; Lötters, Joost Conrad; Fernandez, Luis J.

2017-01-01

Abstract This work presents the modelling, design, fabrication and test of the first micro Coriolis mass flow sensor fully fabricated in SU-8 by photolithography processes. The sensor consists of a channel with rectangular cross-section with inner opening of 100 μm × 100 μm and is actuated at

A proof of concept of a BioMEMS glucose biosensor using microfabricated SU-8 films

OpenAIRE

Psoma, Sotiria D.

2009-01-01

The present project investigated and proved the concept of developing a novel BioMEMS glucose micro-biosensor using a simple one-step microfabrication process of the widely used SU-8 polymer. More specifically, the study focused on the investigation of the suitability of the SU-8 polymer as a matrix for enzyme immobilisation that is carried out during the microfabrication process. A comparative study between commercially available SU-8 and “customised” SU-8 solutions showed tha...

Tailoring the mechanical properties of SU-8/clay nanocomposites: polymer microcantilever fabrication perspective

CSIR Research Space (South Africa)

Chen, H

2014-03-01

Full Text Available SU-8/Clay nanocomposite is considered as a candidate material for microcantilever sensor fabrication. Organically modified montmorillonite clay nanoparticles are dispersed in the universally used negative photoresist polymer SU-8, for a low cost...

Surface modification of SU8 photoresist for shrinkage improvement in a monolithic MEMS microstructure

Science.gov (United States)

Chung, C. K.; Hong, Y. Z.

2007-02-01

The effect of O2 plasma treatment on the surface property of exposed and unexposed SU8 photoresist has been investigated for the fabrication of a monolithic MEMS microstructure. It can solve the non-uniformity problem of second resist coating on the SU8 with high intrinsic shrinkage after exposure and post-exposure baking (PEB) in the fabrication of the stacked polymer-metal or polymer-polymer structure, which was used in the application of microfluid, bio and chemistry. The thickness difference of untreated SU8 before PEB between the exposed and unexposed SU8 was about 0.3% while that after PEB increased to about 6%. It could result in large non-uniformity of about 18 µm thickness difference for the following second resist coating on the hydrophobic surface without plasma treatment. The surface property of SU8 in terms of the contact angle and surface energy can be adjusted by O2 plasma treatment for enhancing the coating uniformity of the following resist. The measured contact angles of the exposed and unexposed SU8 decrease with O2 plasma time, corresponding to the increased surface energy determined by the Lifshitz-van der Waals/Lewis acid-base approach. It displayed that the similar hydrophilic surface property can minimize the thickness difference of second resist coating on the first shrunken SU8. A monolithic nozzle plate with a physical resolution of 600 dpi in a single column was demonstrated for an inkjet application based on the improved uniformity.

SU-8 Lenses: Simple Methods of Fabrication and Application in Optical Interconnection Between Fiber/LED and Microstructures

Science.gov (United States)

Nguyen, Minh-Hang; Nguyen, Hai-Binh; Nguyen, Tuan-Hung; Vu, Xuan-Manh; Lai, Jain-Ren; Tseng, Fan-Gang; Chen, Te-Chang; Lee, Ming-Chang

2016-05-01

This paper presents two facile methods to fabricate off-plane lenses made of SU-8, an epoxy-based negative photoresist from MicroChem, on glass for optical interconnection. The methods allow the fabrication of lenses with flexible spot size and focal length depending on SU-8 well size and SU-8 drop volume and viscosity. In the first method, SU-8 drops were applied directly into patterned SU-8 wells with Teflon-coated micropipettes, and were baked to become (a)-spherical lenses. The lens shape and size were mainly determined by SU-8 viscosity, ratio of drop volume to well volume, and baking temperature and time. In the second method, a glass substrate with SU-8 patterned wells was emerged in diluted SU-8, then drawn up and baked to form lenses. The lens shapes and sizes were mainly determined by SU-8 viscosity and well volume. By the two methods, SU-8 lenses were successfully fabricated with spot sizes varying in range from micrometers to hundred micrometers, and focal lengths varying in range of several millimeters, depending on the lens rim diameters and aspheric sag height. Besides, on-plane SU-8 lenses were fabricated by photolithography to work in conjunction with the off-plane SU-8 lenses. The cascaded lenses produced light spots reduced to several micrometers, and they can be applied as a coupler for light coupling from fiber/Light-emitting diode (LED) to microstructures and nanostructures. The results open up the path for fabricating novel optical microsystems for optical communication and optical sensing applications.

Effects of post exposure bake temperature and exposure time on SU-8 nanopattern obtained by electron beam lithography

Science.gov (United States)

Yasui, Manabu; Kazawa, Elito; Kaneko, Satoru; Takahashi, Ryo; Kurouchi, Masahito; Ozawa, Takeshi; Arai, Masahiro

2014-11-01

SU-8 is a photoresist imaged using UV rays. However, we investigated the characteristics of an SU-8 nanopattern obtained by electron beam lithography (EBL). In particular, we studied the relationship between post-exposure bake (PEB) temperature and exposure time on an SU-8 nanopattern with a focus on phase transition temperature. SU-8 residue was formed by increasing both PEB temperature and exposure time. To prevent the formation of this, Monte Carlo simulation was performed; the results of such simulation showed that decreasing the thickness of SU-8 can reduce the amount of residue from the SU-8 nanopattern. We confirmed that decreasing the thickness of SU-8 can also prevent the formation of residue from the SU-8 nanopattern with EBL.

Single-mode waveguides with SU-8 polymer core and cladding for MOEMS applications

DEFF Research Database (Denmark)

Nordström, Maria; Zauner, Dan; Boisen, Anja

2007-01-01

Fabrication and optical characterization of singlemode polymeric embedded waveguides are performed. A specific material combination (SU-8 2005 as core and the modified SU-8 mr-L 6050XP as cladding) is chosen in order to obtain a small refractive index difference for single-mode propagation combined...... can fabricate waveguides with an index difference in the order of 10−3, where both the core material and the cladding material are based on SU-8. The refractive index measurements are performed on thin polymeric films, while further optical characterizations are performed on waveguides with a height...

Humidity influence on the adhesion of SU-8 polymer from MEMS applications

Directory of Open Access Journals (Sweden)

Birleanu Corina

2017-01-01

Full Text Available In this paper, the adhesion behaviors of SU-8 polymer thin film from MEMS application were investigated as a function of relative humidity. The adhesion test between the AFM tip and SU-8 polymer have been extensively studied using the atomic force microscope (AFM, for a relative humidity (RH varying between 20 and 90%. The samples for tests are SU-8 polymers hard baked at different temperatures. The hard bake temperature changes the tribo-mechanical properties of polymers. The paper reports the measurements and the modeling of adhesion forces versus humidity in controlled ranges between 20 to 90%RH. To investigate the effect of relative humidity on adhesion for SU-8 polymer hard baked we used an analytical method which encompasses the effect of capillarity as well as the solid-to-solid interaction. While the capillary force expression is considered to be the sum of the superficial tension and the Laplace force for the solid-solid interaction is expressed by the Derjagin, Muller and Toropov (DMT model of solids adhesion. The analytical results obtained are in accordance with those obtained experimentally.

SU-8-based microneedles for in vitro neural applications

International Nuclear Information System (INIS)

Altuna, Ane; Tijero, María; Berganzo, Javier; Salido, Rafa; Fernández, Luis J; Gabriel, Gemma; Guimerá, Anton; Villa, Rosa; Menéndez de la Prida, Liset

2010-01-01

This paper presents novel design, fabrication, packaging and the first in vitro neural activity recordings of SU-8-based microneedles. The polymer SU-8 was chosen because it provides excellent features for the fabrication of flexible and thin probes. A microprobe was designed in order to allow a clean insertion and to minimize the damage caused to neural tissue during in vitro applications. In addition, a tetrode is patterned at the tip of the needle to obtain fine-scale measurements of small neuronal populations within a radius of 100 µm. Impedance characterization of the electrodes has been carried out to demonstrate their viability for neural recording. Finally, probes are inserted into 400 µm thick hippocampal slices, and simultaneous action potentials with peak-to-peak amplitudes of 200–250 µV are detected.

Highlights of SPring-8 BL23SU in 2001

CERN Document Server

Agui, A; Nakatani, T; Yokoya, A; Yoshigoe, A

2002-01-01

BL23SU in SPring-8 is a soft x-ray beamline for the material science project in JAERI. The insertion device, monochromator and other beamline equipments have been installed or developed. The beamline maintenance has also been continued. We report highlights of these activities for the BL23SU in 2001. Specially, it has proceeded with the countermeasure against the rise in the maximum radiant power, toward the low-energy operation realization. And, improvement in that precision proceeds through the COD correlation to the ID drive as well.

Improved anti-stiction coating of SU-8 molds

DEFF Research Database (Denmark)

Lange, Jacob Moresco; Clausen, Casper Hyttel; Svendsen, Winnie Edith

2010-01-01

of the epoxy groups by oxygen plasma or sulfuric acid improves the deposition of FDTS. The deposition of FDTS on acid-activated and untreated SU-8 gave an identical well performing anti-stiction coating, as opposed to oxygen plasma activated surface which resulted in a poor FDTS coverage. In this paper...

Bi cluster-assembled interconnects produced using SU8 templates

International Nuclear Information System (INIS)

Partridge, J G; Matthewson, T; Brown, S A

2007-01-01

Bi clusters with an average diameter of 25 nm have been deposited from an inert gas aggregation source and assembled into thin-film interconnects which are formed between planar electrical contacts and supported on Si substrates passivated with Si 3 N 4 or thermally grown oxide. A layer of SU8 (a negative photoresist based on EPON SU-8 epoxy resin) is patterned using optical or electron-beam lithography, and it defines the position and dimensions of the cluster film. The conduction between the contacts is monitored throughout the deposition/assembly process, and subsequent I(V) characterization is performed in situ. Bi cluster-assembled interconnects have been fabricated with nanoscale widths and with up to 1:1 thickness:width aspect ratios. The conductivity of these interconnects has been increased, post-deposition, using a simple thermal annealing process

SU-8 Cantilevers for Bio/chemical Sensing; Fabrication, Characterisation and Development of Novel Read-out Methods

Directory of Open Access Journals (Sweden)

Anja Boisen

2008-03-01

Full Text Available Here, we present the activities within our research group over the last five yearswith cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interestingpolymer for fabrication of cantilevers for bio/chemical sensing due to its simple processingand low Young’s modulus. We show examples of different integrated read-out methodsand their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity tochanges in the environmental temperature and pH of the buffer solution. Moreover, weshow that the SU-8 cantilever surface can be functionalised directly with receptormolecules for analyte detection, thereby avoiding gold-thiol chemistry.

Combined electron beam and UV lithography in SU-8

DEFF Research Database (Denmark)

Gersborg-Hansen, Morten; Thamdrup, Lasse Højlund; Mironov, Andrej

2007-01-01

We present combined electron beam and UV lithography (CEUL) in SU-8 as a fast and flexible lithographic technique for prototyping of functional polymer devices and pattern transfer applications. CEUL is a lithographic technique suitable for defining both micrometer and nanometer scale features...

PMMA to SU-8 bonding for polymer based lab-on-a-chip systems with integrated optics

DEFF Research Database (Denmark)

Olsen, Brian Bilenberg; Nielsen, Theodor; Clausen, Bjarne Hans

2004-01-01

We present an adhesive bonding technique developed for SU-8 based "lab-on-a-chip"- systems with integrated optical components. Microfluidic channels and optical components (e.g. wave-guides) are defined in SU-8 photoresist on a Pyrex glass substrate. The microfluidic channels are sealed by a second...... Pyrex substrate, bonded on top of the cross-linked SU-8 structure using an inter- mediate layer of 950K molecular weight poly-methylmethacrylate (PMMA). Due to a lower refractive index of PMMA, this bonding technique offers optical waveguiding in the SU-8 structures in combination with good sealing...... of the microfluidic channels. The bonding technique is investigated with respect to bonding temperature in the range of 50 - 150 degr. C and at bonding forces of 1000 N and 2000 N on a 4-inch wafer. A maximum bonding strength of 16 MPa is achieved for the PMMA to SU-8 bonding at a bonding temperature of 110 degr. C...

A two-step sealing-and-reinforcement SU8 bonding paradigm for the fabrication of shallow microchannels

Science.gov (United States)

Mehboudi, Aryan; Yeom, Junghoon

2018-03-01

Adhesive bonding is a key technique to create microfluidic devices when two separate substrates are used to form microchannels. Among many adhesives explored in microchannel fabrication, SU8 has been widely used as an adhesive layer for sealing the microchannel sidewalls. The majority of the available SU8-based bonding methods, however, suffer from the difficulties associated with sealing of two important types of the microchannel architecture: (1) shallow microchannels with small patterns on a large area, and (2) microchannels with ultra-low aspect ratios (e.g. 6 mm in width and 2~μ m in height). In this paper, a new bonding paradigm based upon the low-temperature and low-pressure SU8 bonding, consisting of two steps of sealing using a thin-SU8-coated PET film and bonding reinforcement using a SU8-coated glass slide, is proposed to resolve the aforementioned difficulties. Since it does not need complicated instruments such as a wafer bonding machine and a lamination device, the developed bonding paradigm is convenient and economical. We successfully demonstrate the compatibility of the proposed bonding paradigm with the two microchannel fabrication approaches based on the glass wet etching and the SU8 photo-lithography, where small microchannels with the innermost surfaces fully made of SU8 are obtained. A theoretical model is employed to better investigate the flow characteristics and the structural behavior of the microchannel including the PET film deformation, strain and von Mises stress distributions, bonding strength, etc. Moreover, we demonstrate the fabrication of the multi-height deep-shallow microchannel sidewalls and their sealing using the SU8-coated PET film. Finally, as a proof-of-concept device, a microfluidic filter consisting of the double-height deep-shallow microchannel is fabricated for separation of 3 µm and 10 µm particles.

Micro-particle filter made in SU-8 for biomedical applications

DEFF Research Database (Denmark)

Noeth, Nadine-Nicole; Keller, Stephan Urs; Fetz, Stefanie

2009-01-01

We have integrated a micro-particle filter in a polymer cantilever to filter micro-particles from a fluid while simultaneously measuring the amount of filtered particles. In a 3,8 mum thick SU-8 cantilever a filter was integrated with pore sizes between 3 and 30 mum. The chip was inserted in a mi...

Fabrication of thin SU-8 cantilevers: initial bending, release and time stability

International Nuclear Information System (INIS)

Keller, Stephan; Boisen, Anja; Haefliger, Daniel

2010-01-01

SU-8 cantilevers with a thickness of 2 µm were fabricated using a dry release method and two steps of SU-8 photolithography. The processing of the thin SU-8 film defining the cantilevers was experimentally optimized to achieve low initial bending due to residual stress gradients. In parallel, the rotational deformation at the clamping point allowed a qualitative assessment of the device release from the fluorocarbon-coated substrate. The change of these parameters during several months of storage at ambient temperature was investigated in detail. The introduction of a long hard bake in an oven after development of the thin SU-8 film resulted in reduced cantilever bending due to removal of residual stress gradients. Further, improved time-stability of the devices was achieved due to the enhanced cross-linking of the polymer. A post-exposure bake at a temperature T PEB = 50 °C followed by a hard bake at T HB = 90 °C proved to be optimal to ensure low cantilever bending and low rotational deformation due to excellent device release and low change of these properties with time. With the optimized process, the reproducible fabrication of arrays with 2 µm thick cantilevers with a length of 500 µm and an initial bending of less than 20 µm was possible. The theoretical spring constant of these cantilevers is k = 4.8 ± 2.5 mN m −1 , which is comparable to the value for Si cantilevers with identical dimensions and a thickness of 500 nm.

Polymer SU-8 Based Microprobes for Neural Recording and Drug Delivery

Science.gov (United States)

Altuna, Ane; Fernandez, Luis; Berganzo, Javier

2015-06-01

This manuscript makes a reflection about SU-8 based microprobes for neural activity recording and drug delivery. By taking advantage of improvements in microfabrication technologies and using polymer SU-8 as the only structural material, we developed several microprobe prototypes aimed to: a) minimize injury in neural tissue, b) obtain high-quality electrical signals and c) deliver drugs at a micrometer precision scale. Dedicated packaging tools have been developed in parallel to fulfill requirements concerning electric and fluidic connections, size and handling. After these advances have been experimentally proven in brain using in vivo preparation, the technological concepts developed during consecutive prototypes are discussed in depth now.

POLYMER SU-8 BASED MICROPROBES FOR NEURAL RECORDING AND DRUG DELIVERY

Directory of Open Access Journals (Sweden)

Ane eAltuna

2015-06-01

Full Text Available This manuscript makes a reflection about SU-8 based microprobes for neural activity recording and drug delivery. By taking advantage of improvements in microfabrication technologies and using polymer SU-8 as the only structural material, we developed several microprobe prototypes aimed to: a minimize injury in neural tissue, b obtain high-quality electrical signals and c deliver drugs at a micrometer precision scale. Dedicated packaging tools have been developed in parallel to fulfill requirements concerning electric and fluidic connections, size and handling. After these advances have been experimentally proven in brain using in vivo preparation, the technological concepts developed during consecutive prototypes are discussed in depth now.

Performance of SU-8 Membrane Suitable for Deep X-Ray Grayscale Lithography

Directory of Open Access Journals (Sweden)

Harutaka Mekaru

2015-02-01

Full Text Available In combination with tapered-trench-etching of Si and SU-8 photoresist, a grayscale mask for deep X-ray lithography was fabricated and passed a 10-times-exposure test. The performance of the X-ray grayscale mask was evaluated using the TERAS synchrotron radiation facility at the National Institute of Advanced Industrial Science and Technology (AIST. Although the SU-8 before photo-curing has been evaluated as a negative-tone photoresist for ultraviolet (UV and X-ray lithographies, the characteristic of the SU-8 after photo-curing has not been investigated. A polymethyl methacrylate (PMMA sheet was irradiated by a synchrotron radiation through an X-ray mask, and relationships between the dose energy and exposure depth, and between the dose energy and dimensional transition, were investigated. Using such a technique, the shape of a 26-μm-high Si absorber was transformed into the shape of a PMMA microneedle with a height of 76 μm, and done with a high contrast. Although during the fabrication process of the X-ray mask a 100-μm-pattern-pitch (by design was enlarged to 120 μm. However, with an increase in an integrated dose energy this number decreased to 99 μm. These results show that the X-ray grayscale mask has many practical applications. In this paper, the author reports on the evaluation results of SU-8 when used as a membrane material for an X-ray mask.

A facile micropatterning method for a highly flexible PEDOT:PSS on SU-8

KAUST Repository

Cho, Nam Chul

2016-04-17

We report the micropatterning of conducting polymer on the epoxy-based photoresist to demonstrate fully organic, conducting and flexible electrodes. We show that polystyrene sulfonic acid can be covalently linked to the surface of the photoresist (SU-8) by forming sulfonyl ester at the interfaces. We also present an application of the patterned PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate)/SU-8 to the electroplating of metal electrodes. © 2016 Elsevier B.V.

A facile micropatterning method for a highly flexible PEDOT:PSS on SU-8

KAUST Repository

Cho, Nam Chul; Diekhans, Justin; Steward, Malia; Bakr, Osman; Choi, Seungkeun

2016-01-01

We report the micropatterning of conducting polymer on the epoxy-based photoresist to demonstrate fully organic, conducting and flexible electrodes. We show that polystyrene sulfonic acid can be covalently linked to the surface of the photoresist (SU-8) by forming sulfonyl ester at the interfaces. We also present an application of the patterned PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate)/SU-8 to the electroplating of metal electrodes. © 2016 Elsevier B.V.

Low Cost SU8 Based Above IC Process for High Q RF Power Inductors Integration

International Nuclear Information System (INIS)

Ghannam, A.; Bourrier, D.; Viallon, Ch.; Parra, Th.

2011-01-01

This paper presents a new process for integration of high-Q RF power inductors above low resistivity silicon substrates. The process uses the SU8 resin as a dielectric layer. The aim of using the SU8 is to form thick dielectric layer that can enhance the performance of the inductors. The flexibility of the process enables the possibility to realize complex shaped planar inductors with various dielectric and metal thicknesses to meet the requirements of the application. Q values of 55 at 5 GHz has been demonstrated for an inductance value of 0.8 nH using a 60 μm thick SU8 layer and 30 μm thick copper ribbons. (author)

SU-8 Cantilevers for Bio/chemical Sensing; Fabrication, Characterisation and Development of Novel Read-out Methods

OpenAIRE

Anja Boisen; Mogens Havsteen-Jakobsen; Gabriela Blagoi; Daniel Haefliger; Søren Dohn; Alicia Johansson; Michael Lillemose; Stephan Keller; Maria Nordström

2008-01-01

Here, we present the activities within our research group over the last five years with cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interesting polymer for fabrication of cantilevers for bio/chemical sensing due to its simple processing and low Young's modulus. We show examples of different integrated read-out methods and their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity to changes in the environmental temperature and pH of the bu...

Single-mode waveguides with SU-8 polymer core and cladding for MOEMS applications

OpenAIRE

Nordström, Maria; Zauner, Dan; Boisen, Anja; Hübner, Jörg

2007-01-01

Fabrication and optical characterization of singlemode polymeric embedded waveguides are performed. A specific material combination (SU-8 2005 as core and the modified SU-8 mr-L 6050XP as cladding) is chosen in order to obtain a small refractive index difference for single-mode propagation combined with the conventional fabrication method UV lithography to facilitate the integration of different types of optical detection methods on lab-on-a-chip systems. We analyze the behavior of the refrac...

SU-8 photoresist-derived electrospun carbon nanofibres as high ...

Indian Academy of Sciences (India)

... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 40; Issue 3. SU-8 photoresist-derived electrospun carbon nanofibres as high-capacity anode material for lithium ion battery. M KAKUNURI S KAUSHIK A SAINI C S SHARMA. Volume 40 Issue 3 June 2017 pp 435-439 ...

SU-8 Based MEMS Process with Two Metal Layers using α-Si as a Sacrificial Material

KAUST Repository

Ramadan, Khaled S.

2012-04-01

Polymer based microelectromechanical systems (MEMS) micromachining is finding more interest in research and applications. This is due to its low cost and less time processing compared with silicon MEMS. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic devices. In addition to being processed with low cost, it is a biocompatible material with good mechanical properties. Also, amorphous silicon (α-Si) has found use as a sacrificial layer in silicon MEMS applications. α-Si can be deposited at large thicknesses for MEMS applications and also can be released in a dry method using XeF2 which can solve stiction problems related to MEMS applications. In this thesis, an SU-8 MEMS process is developed using amorphous silicon (α-Si) as a sacrificial layer. Electrostatic actuation and sensing is used in many MEMS applications. SU-8 is a dielectric material which limits its direct use in electrostatic actuation. This thesis provides a MEMS process with two conductive metal electrodes that can be used for out-of-plane electrostatic applications like MEMS switches and variable capacitors. The process provides the fabrication of dimples that can be conductive or non-conductive to facilitate more flexibility for MEMS designers. This SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were tuned for two sets of thicknesses which are thin (5-10μm) and thick (130μm). Chevron bent-beam structures and different suspended beams (cantilevers and bridges) were fabricated to characterize the SU-8 process through extracting the density, Young’s Modulus and the Coefficient of Thermal Expansion (CTE) of SU-8. Also, the process was tested and used as an educational tool through which different MEMS structures were fabricated including MEMS switches, variable capacitors and thermal actuators.

Fabrication of SU-8 low frequency electrostatic energy harvester

KAUST Repository

Ramadan, Khaled S.; Foulds, Ian G.

2011-01-01

A 1500μm × 1500μm × 150μm out-of-plane, gap closing, electrostatic energy harvester is designed and fabricated to harvest low-frequency ambient vibrations. SU-8 is used to fabricate the proof mass (1200μm × 1200μm × 150μm) and the 5 m springs

Direct injection in organic SU8 nanowires and nanotubes for waveguiding properties investigation

Science.gov (United States)

Bigeon, J.; Huby, N.; Duvail, Jean-Luc; Bêche, Bruno

2014-05-01

We report photonic concepts related to injection and sub-wavelength propagation in nanofibers (nanowires and nanotubes). These nanostructures are fabricated by the wetting template method leading to aspect ratio of over 250. At first, injection into nanowires and nanotubes of SU8, a photoresist used for integrated photonics, was successfully achieved by using polymer microlensed fibers with sub-micronic radius of curvature. Theoret- ical simulation by finite domain time-dependent (FDTD) method was used to determine the sub-wavelength propagation for nanowires and nanotubes and corroborate this coupling phenomena. The original confinement of energy density into SU8 nanotubes is highlighted. Finally, characterisation of propagation losses is reported by using a cut-back method transposed to such nanotubes and determined to range between 1 and 2 dB/mm. Both injection and cut-back method developed here are compatible with any sub-micronic structures. This work on SU8 nanofibers suggests broader perspectives for future nanophotonics.

Special Issue: 15 Years of SU8 as MEMS Material

Directory of Open Access Journals (Sweden)

Arnaud Bertsch

2015-06-01

Full Text Available In 1997, the first paper using SU-8 as a material for microfabrication was published [1], demonstrating the interest of this negative photoresist for the near-UV structuration of thick layers and the manufacturing of high aspect-ratio components.[...

Mode-locked fiber laser using SU8 resist incorporating carbon nanotubes

Science.gov (United States)

Hernandez-Romano, Ivan; Mandridis, Dimitrios; May-Arrioja, Daniel A.; Sanchez-Mondragon, Jose J.; Delfyett, Peter J.

2011-06-01

We report the fabrication of a saturable absorber made of a novel polymer SU8 doped with Single Wall Carbon Nanotubes (SWCNTs). A passive mode-locked ring cavity fiber laser was built with a 100 μm thick SU8/SWCNT film inserted between two FC/APC connectors. Self-starting passively mode-locked lasing operation was observed at 1572.04 nm, with a FWHM of 3.26 nm. The autocorrelation trace was 1.536 ps corresponding to a pulse-width of 871 fs. The time-bandwidth product was 0.344, which is close enough to transform-limited sech squared pulses. The repetition rate was 21.27 MHz, and a maximum average output power of 1 mW was also measured.

Simulation and experimental validation of a SU-8 based PCR thermocycler chip with integrated heaters and temperature sensor

DEFF Research Database (Denmark)

El-Ali, Jamil; Perch-Nielsen, Ivan R.; Poulsen, Claus Riber

2004-01-01

We present a SU-8 based polymerase chain reaction (PCR) chip with integrated platinum thin film heaters and temperature sensor. The device is fabricated in SU-8 on a glass substrate. The use of SU-8 provides a simple microfabrication process for the PCR chamber, controllable surface properties......C/s, respectively, the performance of the chip is comparable with the best silicon micromachined PCR chips presented in the literature. The SU-8 chamber surface was found to be PCR compatible by amplification of yeast gene ribosomal protein S3 and Campylobacter gene cadF. The PCR compatibility of the chamber...

Use of SU8 as a stable and biocompatible adhesion layer for gold bioelectrodes.

Science.gov (United States)

Matarèse, Bruno F E; Feyen, Paul L C; Falco, Aniello; Benfenati, Fabio; Lugli, Paolo; deMello, John C

2018-04-03

Gold is the most widely used electrode material for bioelectronic applications due to its high electrical conductivity, good chemical stability and proven biocompatibility. However, it adheres only weakly to widely used substrate materials such as glass and silicon oxide, typically requiring the use of a thin layer of chromium between the substrate and the metal to achieve adequate adhesion. Unfortunately, this approach can reduce biocompatibility relative to pure gold films due to the risk of the underlying layer of chromium becoming exposed. Here we report on an alternative adhesion layer for gold and other metals formed from a thin layer of the negative-tone photoresist SU-8, which we find to be significantly less cytotoxic than chromium, being broadly comparable to bare glass in terms of its biocompatibility. Various treatment protocols for SU-8 were investigated, with a view to attaining high transparency and good mechanical and biochemical stability. Thermal annealing to induce partial cross-linking of the SU-8 film prior to gold deposition, with further annealing after deposition to complete cross-linking, was found to yield the best electrode properties. The optimized glass/SU8-Au electrodes were highly transparent, resilient to delamination, stable in biological culture medium, and exhibited similar biocompatibility to glass.

SU(8) family unification with boson-fermion balance

CERN Multimedia

CERN. Geneva

2014-01-01

Grand unification has been intensively investigated for over forty years, and many different approaches have been tried. In this talk I propose a model that involves three ingredients that do not appear in the usual constructions: (1) boson--fermion balance without full supersymmetry, (2) canceling the spin 1/2 fermion gauge anomalies against the anomaly from a gauged spin 3/2 gravitino, and (3) using a scalar field representation with non-zero U(1) generator to break the SU(8) gauge symmetry through a ground state which, before dynamical symmetry breaking, has a periodic U(1) generator structure. The model has a number of promising features: (1) natural incorporation of three families, (2) incorporation of the experimentally viable flipped SU(5) model, (3) a symmetry breaking pathway to the standard model using the scalar field required by boson-fermion balance, together with a stage of most attractive channel dynamical symmetry breaking, without postulating additional Higgs fields, (4) vanishing of bare Yuk...

Fabrication of high-aspect ratio SU-8 micropillar arrays

DEFF Research Database (Denmark)

Amato, Letizia; Keller, Stephan S.; Heiskanen, Arto

2012-01-01

to the resolution limit of photolithography. This paper describes process optimization for the fabrication of dense SU-8 micropillar arrays (2.5μm spacing) with nominal height ⩾20μm and nominal diameter ⩽2.5μm (AR ⩾8). Two approaches, differing in temperature, ramping rate and duration of the baking steps were...... compared as part of the photolithographic processing, in order to evaluate the effect of baking on the pattern resolution. Additionally, during the post-processing, supercritical point drying and hard baking were introduced yielding pillars with diameter 1.8μm, AR=11 and an improved temporal stability....

Drift study of SU8 cantilevers in liquid and gaseous environments.

Science.gov (United States)

Tenje, Maria; Keller, Stephan; Dohn, Søren; Davis, Zachary J; Boisen, Anja

2010-05-01

We present a study of the drift, in terms of cantilever deflections without probe/target interactions, of polymeric SU8 cantilevers. The drift is measured in PBS buffer (pH 7.4) and under vacuum (1mbar) conditions. We see that the cantilevers display a large drift in both environments. We believe this is because the polymer matrix absorbs liquid in one situation whereas it is being degassed in the other. An inhomogeneous expansion/contraction of the cantilever is seen because one surface of the cantilever may still have remains of the release layer from the fabrication. To further study the effect, we coat the cantilevers with a hydrophobic coating, perfluorodecyltrichlorosilane (FDTS). Fully encapsulating the SU8 cantilever greatly reduces the drift in liquid whereas a less significant change is seen in vacuum.

Drift study of SU8 cantilevers in liquid and gaseous environments

DEFF Research Database (Denmark)

Tenje, Maria; Keller, Stephan Sylvest; Dohn, Søren

2010-01-01

We present a study of the drift, in terms of cantilever deflections without probe/target interactions, of polymeric SU8 cantilevers. The drift is measured in PBS buffer (pH 7.4) and under vacuum (1 mbar) conditions. We see that the cantilevers display a large drift in both environments. We believe...... coat the cantilevers with a hydrophobic coating, perfluorodecyltrichlorosilane (FDTS). Fully encapsulating the SU8 cantilever greatly reduces the drift in liquid whereas a less significant change is seen in vacuum....... this is because the polymer matrix absorbs liquid in one situation whereas it is being degassed in the other. An inhomogeneous expansion/contraction of the cantilever is seen because one surface of the cantilever may still have remains of the release layer from the fabrication. To further study the effect, we...

PMMA to SU-8 Bonding for Polymer Based Lab-on-a-chip Systems with Integrated Optics

DEFF Research Database (Denmark)

Olsen, Brian Bilenberg; Nielsen, Theodor; Nilsson, Daniel

2003-01-01

An adhesive bonding technique for wafer-level sealing of SU-8 based lab-on-a-chip microsystems with integrated optical components is presented. Microfluidic channels and optical components, e.g. waveguides, are fabricated in cross-linked SU-8 and sealed with a Pyrex glass substrate by means...... strength of 16 MPa is achieved at bonding temperatures between 110 oC and 120oC, at a bonding force of 2000 N on a 4-inch wafer. The optical propagation loss of multi-mode 10ym (thickness)x 30ym (width)SU-8 waveguides is measured. The propagation loss in PMMA bonded waveguide struc-tures is more than 5 d......B/cm lower, at wavelengths between 600nm and 900 nm, than in similar structures bonded by an intermediate layer of SU-8. Furthermore 950K PMMA shows no tendency to flow into the bonded structures during bonding because of its high viscosity....

Using an SU-8 Photoresist Structure and Cytochrome C Thin Film Sensing Material for a Microbolometer

Directory of Open Access Journals (Sweden)

Guo-Dung John Su

2012-11-01

Full Text Available There are two critical parameters for microbolometers: the temperature coefficient of resistance (TCR of the sensing material, and the thermal conductance of the insulation structure. Cytochrome c protein, having a high TCR, is a good candidate for infrared detection. We can use SU-8 photoresist for the thermal insulation structure, given its low thermal conductance. In this study, we designed a platform structure based on a SU-8 photoresist. We fabricated an infrared sensing pixel and recorded a high TCR for this new structure. The SU-8 photoresist insulation structure was fabricated using the exposure dose method. We experimentally demonstrated high values of TCR from 22%/K to 25.7%/K, and the measured noise was 1.2 × 10–8 V2/Hz at 60 Hz. When the bias current was 2 μA, the calculated voltage responsivity was 1.16 × 105 V/W. This study presents a new kind of microbolometer based on cytochrome c protein on top of an SU-8 photoresist platform that does not require expensive vacuum deposition equipment.

Silicon/SU8 multi-electrode micro-needle for in vivo neurochemical monitoring.

Science.gov (United States)

Vasylieva, Natalia; Marinesco, Stéphane; Barbier, Daniel; Sabac, Andrei

2015-10-15

Simultaneous monitoring of glucose and lactate is an important challenge for understanding brain energetics in physiological or pathological states. We demonstrate here a versatile method based on a minimally invasive single implantation in the rat brain. A silicon/SU8-polymer multi-sensing needle-shaped biosensor, was fabricated and tested. The multi-electrode array design comprises three platinum planar microelectrodes with a surface area of 40 × 200 µm(2) and a spacing of 200 µm, which were micromachined on a single 3mm long micro-needle having a 100 × 50 µm(2) cross-section for reduced tissue damage during implantation. Platinum micro-electrodes were aligned at the bottom of micro-wells obtained by photolithography on a SU8 photoresist layer. After clean room processing, each micro-electrode was functionalized inside the micro-wells by means of a micro-dispensing device, either with glucose oxidase or with lactate oxidase, which were cross-linked on the platinum electrodes. The third electrode covered with Bovine Serum Albumin (BSA) was used for the control of non-specific currents. The thick SU8 photoresist layer has revealed excellent electrical insulation of the micro-electrodes and between interconnection lines, and ensured a precise localization and packaging of the sensing enzymes on platinum micro-electrodes. During in vitro calibration with concentrations of analytes in the mM range, the micro-wells patterned in the SU8 photoresist proved to be highly effective in eliminating cross-talk signals, caused by H2O2 diffusion from closely spaced micro-electrodes. Moreover, our biosensor was successfully assayed in the rat cortex for simultaneous monitoring of both glucose and lactate during insulin and glucose administration. Copyright © 2015 Elsevier B.V. All rights reserved.

SU-8 hollow cantilevers for AFM cell adhesion studies

Science.gov (United States)

Martinez, Vincent; Behr, Pascal; Drechsler, Ute; Polesel-Maris, Jérôme; Potthoff, Eva; Vörös, Janos; Zambelli, Tomaso

2016-05-01

A novel fabrication method was established to produce flexible, transparent, and robust tipless hollow atomic force microscopy (AFM) cantilevers made entirely from SU-8. Channels of 3 μm thickness and several millimeters length were integrated into 12 μm thick and 40 μm wide cantilevers. Connected to a pressure controller, the devices showed high sealing performance with no leakage up to 6 bars. Changing the cantilever lengths from 100 μm to 500 μm among the same wafer allowed the targeting of various spring constants ranging from 0.5 to 80 N m-1 within a single fabrication run. These hollow polymeric AFM cantilevers were operated in the optical beam deflection configuration. To demonstrate the performance of the device, single-cell force spectroscopy experiments were performed with a single probe detaching in a serial protocol more than 100 Saccharomyces cerevisiae yeast cells from plain glass and glass coated with polydopamine while measuring adhesion forces in the sub-nanoNewton range. SU-8 now offers a new alternative to conventional silicon-based hollow cantilevers with more flexibility in terms of complex geometric design and surface chemistry modification.

SU-8 hollow cantilevers for AFM cell adhesion studies

International Nuclear Information System (INIS)

Martinez, Vincent; Behr, Pascal; Vörös, Janos; Zambelli, Tomaso; Drechsler, Ute; Polesel-Maris, Jérôme; Potthoff, Eva

2016-01-01

A novel fabrication method was established to produce flexible, transparent, and robust tipless hollow atomic force microscopy (AFM) cantilevers made entirely from SU-8. Channels of 3 μm thickness and several millimeters length were integrated into 12 μm thick and 40 μm wide cantilevers. Connected to a pressure controller, the devices showed high sealing performance with no leakage up to 6 bars. Changing the cantilever lengths from 100 μm to 500 μm among the same wafer allowed the targeting of various spring constants ranging from 0.5 to 80 N m −1 within a single fabrication run. These hollow polymeric AFM cantilevers were operated in the optical beam deflection configuration. To demonstrate the performance of the device, single-cell force spectroscopy experiments were performed with a single probe detaching in a serial protocol more than 100 Saccharomyces cerevisiae yeast cells from plain glass and glass coated with polydopamine while measuring adhesion forces in the sub-nanoNewton range. SU-8 now offers a new alternative to conventional silicon-based hollow cantilevers with more flexibility in terms of complex geometric design and surface chemistry modification. (paper)

SU-8 as a material for lab-on-a-chip-based mass spectrometry.

Science.gov (United States)

Arscott, Steve

2014-10-07

This short review focuses on the application of SU-8 for the microchip-based approach to the miniaturization of mass spectrometry. Chip-based mass spectrometry will make the technology commonplace and bring benefits such as lower costs and autonomy. The chip-based miniaturization of mass spectrometry necessitates the use of new materials which are compatible with top-down fabrication involving both planar and non-planar processes. In this context, SU-8 is a very versatile epoxy-based, negative tone resist which is sensitive to ultraviolet radiation, X-rays and electron beam exposure. It has a very wide thickness range, from nanometres to millimetres, enabling the formation of mechanically rigid, very high aspect ratio, vertical, narrow width structures required to form microfluidic slots and channels for laboratory-on-a-chip design. It is also relatively chemically resistant and biologically compatible in terms of the liquid solutions used for mass spectrometry. This review looks at the impact and potential of SU-8 on the different parts of chip-based mass spectrometry - pre-treatment, ionization processes, and ion sorting and detection.

SU-8 based microdevices to study self-induced chemotaxis in 3D microenvironments

Science.gov (United States)

Ayuso, Jose; Monge, Rosa; Llamazares, Guillermo; Moreno, Marco; Agirregabiria, Maria; Berganzo, Javier; Doblaré, Manuel; Ochoa, Iñaki; Fernandez, Luis

2015-05-01

Tissues are complex three-dimensional structures in which cell behaviour is frequently guided by chemotactic signals. Although starvation and nutrient restriction induce many different chemotactic processes, the recreation of such conditions in vitro remains difficult when using standard cell culture equipment. Recently, microfluidic techniques have arisen as powerful tools to mimic such physiological conditions. In this context, microfluidic three-dimensional cell culture systems require precise control of cell/hydrogel location because samples need to be placed within a microchamber without obstruction of surrounding elements. In this article, SU-8 is studied as structural material for the fabrication of complex cell culture devices due to its good mechanical properties, low gas permeability and sensor integration capacity. In particular, this manuscript presents a SU-8 based microdevice designed to create “self-induced” medium starvation, based on the combination of nutrient restriction and natural cell metabolism. Results show a natural migratory response towards nutrient source, showing how cells adapt to their own microenvironment modifications. The presented results demonstrate the SU-8 potential for microdevice fabrication applied to cell culture.

SU-8 cantilevers for bio/chemical sensing; Fabrication, characterisation and development of novel read-out methods

DEFF Research Database (Denmark)

Nordström, M.; Keller, Stephan Urs; Lillemose, Michael

2008-01-01

Here, we present the activities within our research group over the last five years with cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interesting polymer for fabrication of cantilevers for bio/chemical sensing due to its simple processing and low Young's modulus. We show...

Electromagnetic characterization of strontium ferrite powders in series 2000, SU8 polymer

Science.gov (United States)

Sholiyi, Olusegun; Williams, John

2014-12-01

In this article, electromagnetic characterization of strontium hexaferrite powders and composites with SU8 was carried out to determine their compatibility with micro and millimeter wave fabrications. The structures of both powders and their composites were scanned with electron microscope to produce the SEM images. Two powder sizes (0.8-1.0 μm and 3-6 μm), were mixed with SU8, spin cast and patterned on wafer, and then characterized using energy dispersive x-ray spectrometry, ferromagnetic resonance (FMR) and vibrating sample magnetometry. In this investigation, FMRs of the samples were determined at 60 GHz while their complex permittivity and permeability were determined using rectangular waveguide method of characterization between 26.5 and 40 GHz frequency range. The results obtained show no adverse effects on the electromagnetic properties of the composites except some slight shift in the resonant frequencies due to anisotropic field of the samples.

Dense vertical SU-8 microneedles drawn from a heated mold with precisely controlled volume

International Nuclear Information System (INIS)

Xiang, Zhuolin; Wang, Hao; Yen, Shih-Cheng; Lee, Chengkuo; Murugappan, Suresh Kanna; Pastorin, Giorgia

2015-01-01

Drawing lithography technology has recently become a popular technique to fabricate (3D) microneedles. The conventional drawing process shows some limitations in fabricating dense, scale-up and small microneedles. In this study, we demonstrate a new drawing lithography process from a self-loading mold which is able to overcome these challenges. Different from the conventional molds which have difficult alignment and loading issues, a released SU-8 membrane is attached onto a SU-8 coated wafer to generate an innovative self-loading mold. The physically distinct SU-8 colloid in this mold successfully avoids the merging of the microneedle tips in the drawing process. Meanwhile, the same SU-8 colloid in mold can provide microneedles with uniform lengths on a large surface area. Furthermore, a low temperature drawing process with this improved technique prevents sharp tips from bending during the solidification stage. Remarkably, this new drawing lithography technology can fabricate microneedles with various lengths and they are strong enough to penetrate the outermost skin layer, namely the stratum corneum. The spacing between two adjacent microneedles is optimized to maximize the penetration rate through the skin. Histology images and drug diffusion testing demonstrate that microchannels are successfully created and the drugs can permeate the tissue under the skin. The fabricated microneedles are demonstrated to deliver insulin in vivo and lower blood glucose levels, suggesting future possible applications for minimally invasive transdermal delivery of macromolecules. (paper)

The gradient flow running coupling in SU2 with 8 flavors

DEFF Research Database (Denmark)

Rantaharju, Jarno; Karavirta, Tuomas; Leino, Viljami

2014-01-01

We present preliminary results of the gradient flow running coupling with Dirichlet boundary condition in the SU(2) gauge theory with 8 fermion flavours. Improvements to the gradient flow measurement allow us to obtain a robust continuum limit. The results are consistent with perturbative running...

Carbonization of SU-8 Based Electrode for MEMS Supercapacitors

OpenAIRE

Liu, Yang

2014-01-01

Supercapacitors are more sustainable and environmentally friendly energy sources than traditional ones. To achieve the supercapacitors with both energy density and power density that mainly depend on the effective surface area of theelectrodes, SU-8 can be used for electrode material to fabricate 3D microstructures as the electrodes that increase the effective surface area significantly. The objective of this project is to fabricate the reliable electrodes of large surface area for supercapac...

Fabrication of SU-8 microstructures for analytical microfluidic applications

OpenAIRE

Tuomikoski, Santeri

2007-01-01

Miniaturization of analytical devices has been an ongoing trend to improve performance of analytical tools. These systems have been microfabricated originally of silicon and glass, but polymers have become increasingly popular as alternative materials. Polymers are mostly used because the material costs are lower and fabrication processes are easier. However, those facts depend heavily on the fabrication method and particular polymer. In this thesis the usability of epoxy-polymer SU-8 has bee...

A new fabrication process for uniform SU-8 thick photoresist structures by simultaneously removing edge bead and air bubbles

International Nuclear Information System (INIS)

Lee, Hun; Lee, Kangsun; Ahn, Byungwook; Xu, Jing; Xu, Linfeng; Oh, Kwang W

2011-01-01

This paper proposes a new SU-8 fabrication process to simultaneously remove edge bead and tiny air bubbles by spraying out edge bead removal (EBR) fluid over the entire surface of photoresist. In particular, the edge bead and air bubbles can cause an air gap between a film mask and a photoresist surface during UV exposure. The diffraction effect of UV light by the air gap leads to inaccurate and non-uniform SU-8 patterns. In this study, we demonstrate a simple method using EBR treatment to simultaneously eliminate the edge bead at the edge of wafer and tiny air bubbles inside SU-8. The profiles of thickness variation of SU-8 films with/without the EBR treatment are measured. The results show that the proposed EBR treatment can successfully remove the edge bead and air bubbles over the entire SU-8 films. The average pattern uniformity of SU-8 is improved from 50.5% to 11.3% in the case of 200 µm thickness. This method is simple and inexpensive, compared to a standard EBR process, because it does not require specialized equipment and it can be applied regardless of substrate geometry (e.g. circular wafer and rectangular slide glass).

Electromagnetic characterization of strontium ferrite powders in series 2000, SU8 polymer

International Nuclear Information System (INIS)

Sholiyi, Olusegun; Williams, John

2014-01-01

In this article, electromagnetic characterization of strontium hexaferrite powders and composites with SU8 was carried out to determine their compatibility with micro and millimeter wave fabrications. The structures of both powders and their composites were scanned with electron microscope to produce the SEM images. Two powder sizes (0.8–1.0 μm and 3–6 μm), were mixed with SU8, spin cast and patterned on wafer, and then characterized using energy dispersive x-ray spectrometry, ferromagnetic resonance (FMR) and vibrating sample magnetometry. In this investigation, FMRs of the samples were determined at 60 GHz while their complex permittivity and permeability were determined using rectangular waveguide method of characterization between 26.5 and 40 GHz frequency range. The results obtained show no adverse effects on the electromagnetic properties of the composites except some slight shift in the resonant frequencies due to anisotropic field of the samples. (paper)

Temperature effects in Au piezoresistors integrated in SU-8 cantilever chips

DEFF Research Database (Denmark)

Johansson, Alicia; Hansen, Ole; Hales, Jan Harry

2006-01-01

We present a cantilever-based biosensor chip made for the detection of biochemical molecules. The device is fabricated entirely in the photosensitive polymer SU-8 except for integrated piezoresistors made of Au. The integrated piezoresistors are used to monitor the surface stress changes due to b...

Order of multiphoton excitation of sulfonium photo-acid generators used in photoresists based on SU-8

Science.gov (United States)

Williams, Henry E.; Diaz, Carlos; Padilla, Gabriel; Hernandez, Florencio E.; Kuebler, Stephen M.

2017-06-01

Multiphoton lithography (MPL), Z-scan spectroscopy, and quantum chemical calculations were employed to investigate the order of multiphoton excitation that occurs when femtosecond laser pulses are used to excite two sulfonium photo-acid generators (PAGs) commonly used in photoresists based on the cross-linkable epoxide SU-8. The mole-fractions of the mono- and bis-sulfonium forms of these PAGs were determined for the commercially available photoresist SU-8 2075 and for the PAGs alone from a separate source. Both were found to contain similar fractions of the mono- and bis-forms, with the mono form present in the majority. Reichert's method was used to determine the solvatochromic strength of the SU-8 matrix, so that results obtained for the PAGs in SU-8 and in solution could be reliably compared. The PAGs were found to exhibit a minimal solvatochromic shift for a series of solvents that span across the solvatochromic strength of SU-8 itself. Sub-micron-sized features were fabricated in SU-8 2075 by MPL using amplified and continuous-wave mode-locked laser pulses. Analysis of the features as a function of average laser power, scan speed, and excitation wavelength shows that the PAGs can be activated by both two- and three-photon absorption (2PA and 3PA). Which activation mode dominates depends principally upon the excitation wavelength because the average laser powers that can be used with the photoresist are limited by practical considerations. The power must be high enough to effect sufficient cross-linking, yet not so high as to exceed the damage threshold of the material. When the laser pulses have a duration on the order of 100 fs, 3PA dominates at wavelengths near 800 nm, whereas 2PA becomes dominant at wavelengths below 700 nm. These findings are corroborated by open-aperture Z-scan measurements and quantum chemical calculations of the cross-sections for 2PA and 3PA as a function of wavelength.

The SU(3)xU(1) invariant breaking of gauged N=8 supergravity

International Nuclear Information System (INIS)

Nicolai, H.; Warner, N.P.

1985-01-01

The SU(3) x U(1) invariant stationary point of N=8 supergravity is described in some detail. This vacuum has N=2 supersymmetry, and it is shown how the fields of N=8 supergravity may be collected into multiplets of SU(3) x Osp(2, 4). A new kind of shortened massive multiplet is described, and the multiplet shortening conditions for this and other multiplets are used to determine, by the use of group theory alone, the masses of many of the fields in the vacuum. The remaining masses are determined by explicit calculation. The critical point realizes Gell-Mann's scheme for relating the spin-1/2 fermions of the theory to the observed quarks and leptons. (orig.)

SU-8 etching in inductively coupled oxygen plasma

DEFF Research Database (Denmark)

Rasmussen, Kristian Hagsted; Keller, Stephan Sylvest; Jensen, Flemming

2013-01-01

Structuring or removal of the epoxy based, photo sensitive polymer SU-8 by inductively coupled plasma reactive ion etching (ICP-RIE) was investigated as a function of plasma chemistry, bias power, temperature, and pressure. In a pure oxygen plasma, surface accumulation of antimony from the photo......-initiator introduced severe roughness and reduced etch rate significantly. Addition of SF6 to the plasma chemistry reduced the antimony surface concentration with lower roughness and higher etch rate as an outcome. Furthermore the etch anisotropy could be tuned by controlling the bias power. Etch rates up to 800 nm...

Uniform fabrication of thick SU-8 patterns on small-sized wafers for micro-optics applications

Science.gov (United States)

Abada, S.; Reig, B.; Daran, E.; Doucet, JB; Camps, T.; Charlot, S.; Bardinal, V.

2014-05-01

This paper reports on an alternative method for precise and uniform fabrication of 100μm-thick SU-8 microstructures on small-sized or non-circular samples. Standard spin-coating of high-viscosity resists is indeed known to induce large edge beads, leading to an air gap between the mask and the SU-8 photo-resist surface during UV photolithography. This results in a non uniform thickness deposition and in a poor pattern definition. This problem becomes highly critical in the case of small-sized samples. To overcome it, we have developed a soft thermal imprint method based on the use of a nano-imprint equipment and applicable whatever sample fragility, shape and size (from 2cm to 6 inches). After final photolithography, the SU8 pattern thickness variation profile is measured. Thickness uniformity is improved from 30% to 5% with a 5μm maximal deviation to the target value over 2cm-long samples.

Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

KAUST Repository

Ramadan, Khaled S.

2013-02-08

This work presents an SU-8 surface micromachining process using amorphous silicon as a sacrificial material, which also incorporates two metal layers for electrical excitation. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic applications due to its mechanical properties, biocompatibility and low cost. Amorphous silicon is used as a sacrificial layer in MEMS applications because it can be deposited in large thicknesses, and can be released in a dry method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using ;-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow out-of-plane electrostatic actuation for applications like MEMS switches and variable capacitors. In order to facilitate more flexibility for MEMS designers, the process can fabricate dimples that can be conductive or nonconductive. Additionally, this SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were optimized for two sets of thicknesses: thin (5-10 m) and thick (130 m). The process was tested fabricating MEMS switches, capacitors and thermal actuators. © 2013 IOP Publishing Ltd.

Distortion of 3D SU8 photonic structures fabricated by four-beam holographic lithography withumbrella configuration.

Science.gov (United States)

Zhu, Xuelian; Xu, Yongan; Yang, Shu

2007-12-10

We present a quantitative study of the distortion from a threeterm diamond-like structure fabricated in SU8 polymer by four-beam holographic lithography. In the study of the refraction effect, theory suggests that the lattice in SU8 should be elongated in the [111] direction but have no distortion in the (111) plane, and each triangular-like hole array in the (111) plane would rotate by ~30 degrees away from that in air. Our experiments agree with the prediction on the periodicity in the (111) plane and the rotation due to refraction effect, however, we find that the film shrinkage during lithographic process has nearly compensated the predicted elongation in the [111] direction. In study of photonic bandgap (PBG) properties of silicon photonic crystals templated by the SU8 structure, we find that the distortion has decreased quality of PBG.

Organic Field-Effect Transistors Based on a Liquid-Crystalline Polymeric Semiconductor using SU-8 Gate Dielectrics onFlexible Substrates.

Science.gov (United States)

Tetzner, Kornelius; Bose, Indranil R; Bock, Karlheinz

2014-10-29

In this work, the insulating properties of poly(4-vinylphenol) (PVP) and SU-8 (MicroChem, Westborough, MA, USA) dielectrics are analyzed and compared with each other. We further investigate the performance behavior of organic field-effect transistors based on a semiconducting liquid-crystal polymer (LCP) using both dielectric materials and evaluate the results regarding the processability. Due to the lower process temperature needed for the SU-8 deposition, the realization of organic transistors on flexible substrates is demonstrated showing comparable charge carrier mobilities to devices using PVP on glass. In addition, a µ-dispensing procedure of the LCP on SU-8 is presented, improving the switching behavior of the organic transistors, and the promising stability data of the SU-8/LCP stack are verified after storing the structures for 60 days in ambient air showing negligible irreversible degradation of the organic semiconductor.

A High-Throughput SU-8Microfluidic Magnetic Bead Separator

DEFF Research Database (Denmark)

Bu, Minqiang; Christensen, T. B.; Smistrup, Kristian

2007-01-01

We present a novel microfluidic magnetic bead separator based on SU-8 fabrication technique for high through-put applications. The experimental results show that magnetic beads can be captured at an efficiency of 91 % and 54 % at flow rates of 1 mL/min and 4 mL/min, respectively. Integration...... of soft magnetic elements in the chip leads to a slightly higher capturing efficiency and a more uniform distribution of captured beads over the separation chamber than the system without soft magnetic elements....

Thermal and optical properties of sol-gel and SU-8 resists

Science.gov (United States)

Suzuki, Toshiyuki; Morikawa, Junko; Hashimoto, Toshimasa; Buividas, Ričardas; Gervinskas, Gediminas; Paipulas, Domas; Malinauskas, Mangirdas; Mizeikis, Vygantas; Juodkazis, Saulius

2012-03-01

We report on a combined differential scanning calorimetric (DSC) and Raman scattering study of thermal polymerization of sol-gel organic-inorganic SZ2080 and SU-8 resists. In SZ2080, endothermic peak at 95°C signify drying of the resist and justifies the required pre-bake at around 100°C for 1-2 h for the best performance during femtosecond (fs-)direct laser writing. A strong exothermic peak at 140°C (under 2 K/min heating rate) completes polymerization of the resist. It is revealed that 1wt% of photoinitiators change Raman scattering intensity of SZ2080 and can contribute efficiently to heating and cross-linking of photo-polymers. In the case of SU-8, a 65°C DSC feature related to solvent evaporation was observed. The strongest changes in Raman spectrum occurs at a narrow 895 cm-1 band which is linked to polymerization. Raman scattering taken during DSC revealed spectral changes following the polymerization; an applicability of this method for monitoring photopolymerization induced by ultra-fast laser sources and feasibility of a laser-modulated calorimetry is discussed.

Organic Field-Effect Transistors Based on a Liquid-Crystalline Polymeric Semiconductor using SU-8 Gate Dielectrics onFlexible Substrates

Directory of Open Access Journals (Sweden)

Kornelius Tetzner

2014-10-01

Full Text Available In this work, the insulating properties of poly(4-vinylphenol (PVP and SU-8 (MicroChem, Westborough, MA, USA dielectrics are analyzed and compared with each other. We further investigate the performance behavior of organic field-effect transistors based on a semiconducting liquid-crystal polymer (LCP using both dielectric materials and evaluate the results regarding the processability. Due to the lower process temperature needed for the SU-8 deposition, the realization of organic transistors on flexible substrates is demonstrated showing comparable charge carrier mobilities to devices using PVP on glass. In addition, a µ-dispensing procedure of the LCP on SU-8 is presented, improving the switching behavior of the organic transistors, and the promising stability data of the SU-8/LCP stack are verified after storing the structures for 60 days in ambient air showing negligible irreversible degradation of the organic semiconductor.

Organic Field-Effect Transistors Based on a Liquid-Crystalline Polymeric Semiconductor using SU-8 Gate Dielectrics on Flexible Substrates

Science.gov (United States)

Tetzner, Kornelius; Bose, Indranil R.; Bock, Karlheinz

2014-01-01

In this work, the insulating properties of poly(4-vinylphenol) (PVP) and SU-8 (MicroChem, Westborough, MA, USA) dielectrics are analyzed and compared with each other. We further investigate the performance behavior of organic field-effect transistors based on a semiconducting liquid-crystal polymer (LCP) using both dielectric materials and evaluate the results regarding the processability. Due to the lower process temperature needed for the SU-8 deposition, the realization of organic transistors on flexible substrates is demonstrated showing comparable charge carrier mobilities to devices using PVP on glass. In addition, a µ-dispensing procedure of the LCP on SU-8 is presented, improving the switching behavior of the organic transistors, and the promising stability data of the SU-8/LCP stack are verified after storing the structures for 60 days in ambient air showing negligible irreversible degradation of the organic semiconductor. PMID:28788243

Biofriendly bonding processes for nanoporous implantable SU-8 microcapsules for encapsulated cell therapy.

Science.gov (United States)

Nemani, Krishnamurthy; Kwon, Joonbum; Trivedi, Krutarth; Hu, Walter; Lee, Jeong-Bong; Gimi, Barjor

2011-01-01

Mechanically robust, cell encapsulating microdevices fabricated using photolithographic methods can lead to more efficient immunoisolation in comparison to cell encapsulating hydrogels. There is a need to develop adhesive bonding methods which can seal such microdevices under physiologically friendly conditions. We report the bonding of SU-8 based substrates through (i) magnetic self assembly, (ii) using medical grade photocured adhesive and (iii) moisture and photochemical cured polymerization. Magnetic self-assembly, carried out in biofriendly aqueous buffers, provides weak bonding not suitable for long term applications. Moisture cured bonding of covalently modified SU-8 substrates, based on silanol condensation, resulted in weak and inconsistent bonding. Photocured bonding using a medical grade adhesive and of acrylate modified substrates provided stable bonding. Of the methods evaluated, photocured adhesion provided the strongest and most stable adhesion.

SP(6) X SU(2) and SO(8) X SU(2) - symmetric fermion-dynamic model of multinucleon systems

International Nuclear Information System (INIS)

Baktybaev, K.

2007-01-01

In last years a new approach describing collective states of multinucleon system on the base of their fermion dynamic symmetry was developed. Such fermion model is broad and logical one in comparison with the phenomenological model of interacting bosons. In cut fermion S- and D- pair spaces complicated nucleons interactions are approximating in that way so multinucleon system Hamiltonian becomes a simple function of fermion generators forming corresponding Lie algebra. Correlation fermion pairs are structured in such form so its operators of birth and destruction together with a set multiband operators are formed Sp(6) and SO(8) algebra of these pairs and SU(2)-algebra for so named anomalous pairs. For convenience at the model practical application to concrete systems the dynamical-symmetric Hamiltonian is writing by means of independent Casimir operators of subgroup are reductions of a large group. It is revealed, that observed Hamiltonians besides the known SU 3 , and SO 6 asymptotic borders have also more complicated 'vibration-like' borders SO 7 , SO 5 XSU 2 and SU 2 XSO 3 . In the paper both advantages and disadvantages of these borders and some its applications to specific nuclear systems are discussing

Novel method for chemical modification and patterning of the SU-8 photoresist

DEFF Research Database (Denmark)

Blagoi, Gabriela; Keller, Stephan Urs; Boisen, Anja

2007-01-01

the wetting behaviour of SU-8. The resolution limit of the AQ photopatterning method was 20 μm when using an uncollimated light source. AQ modification followed by a reaction with amino groups of Alexa-647 cadaverine and a Biotin-amino derivative proved possible modification and patterning of polymeric...

Gauged N=8 supergravity in five dimensions

International Nuclear Information System (INIS)

Guenaydin, M.; Romans, L.J.; Warner, N.P.

1985-01-01

We construct gauged N=8 supergravity theories in five dimensions. Instead of the twenty-seven vector fields of the ungauged theory, the gauged theories contain fifteen vector fields and twelve second-rank antisymmetric tensor fields satisfying self-dual field equations. The fifteen vector fields can be used to gauge any of the fifteen-dimensional semisimple subgroups of SL(6, R), sepcifically SO(p, 6-p) for p=0, 1, 2, 3. The gauged theories also have a physical global SU(1,1) symmetry which survives from the Esub(6(6)) symmetry of the ungauged theory. This SU(1, 1) for the SO(6) gauging is presumably related to that of the chiral N=2 theory in ten dimensions. In our formalism we maintain a composite local USp(8) symmetry analogous to SU(8) in four dimensions. (orig.)

Injection and waveguiding properties in SU8 nanotubes for sub-wavelength regime propagation and nanophotonics integration

Science.gov (United States)

Bigeon, John; Huby, Nolwenn; Duvail, Jean-Luc; Bêche, Bruno

2014-04-01

We report photonic concepts related to injection and sub-wavelength propagation in nanotubes, an unusual but promising geometry for highly integrated photonic devices. Theoretical simulation by the finite domain time-dependent (FDTD) method was first used to determine the features of the direct light injection and sub-wavelength propagation regime within nanotubes. Then, the injection into nanotubes of SU8, a photoresist used for integrated photonics, was successfully achieved by using polymer microlensed fibers with a sub-micronic radius of curvature, as theoretically expected from FDTD simulations. The propagation losses in a single SU8 nanotube were determined by using a comprehensive set-up and a protocol for optical characterization. The attenuation coefficient has been evaluated at 1.25 dB mm-1 by a cut-back method transposed to such nanostructures. The mechanisms responsible for losses in nanotubes were identified with FDTD theoretical support. Both injection and cut-back methods developed here are compatible with any sub-micronic structures. This work on SU8 nanotubes suggests broader perspectives for future nanophotonics.

Dielectric properties of ligand-modified gold nanoparticle/SU-8 photopolymer based nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Toor, Anju, E-mail: atoor@berkeley.edu [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); So, Hongyun, E-mail: hyso@berkeley.edu [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Pisano, Albert P. [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093 (United States)

2017-08-31

Highlights: • Ligand-modified gold NP/SU-8 nanocomposites were synthesized and demonstrated. • Particle agglomeration and dispersion were characterized with different NPs concentration. • Nanocomposites showed higher average dielectric permittivity compared to SU-8 only. • Relatively lower dielectric loss (average 0.09 at 1 kHz) was achieved with 10 % w/w NPs. - Abstract: This article reports the enhanced dielectric properties of a photodefinable polymer nanocomposite material containing sub–10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of the dielectric permittivity and loss tangent on the particle concentration, and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

Gradient flow and IR fixed point in SU(2) with Nf=8 flavors

DEFF Research Database (Denmark)

Leino, Viljami; Karavirta, Tuomas; Rantaharju, Jarno

2015-01-01

We study the running of the coupling in SU(2) gauge theory with 8 massless fundamental representation fermion flavours, using the gradient flow method with the Schr\\"odinger functional boundary conditions. Gradient flow allows us to measure robust continuum limit for the step scaling function...

Development of 3D out-of-plane SU-8 microlenses using modified micromolding in capillaries (MIMIC) technology

Science.gov (United States)

Llobera, A.; Wilke, R.; Johnson, D. W.; Büttgenbach, S.

2006-04-01

This paper describes a modification of the standard MIMIC technology, solving its main drawbacks, to define arrays of spherical or ellipsoidal microlenses. Perfectly symmetrical meniscuses have been obtained by using a XP SU-8 NO-2 layer beneath the PDMS mold. Moreover, the photostructurable properties of this polymer allow obtaining self-alignment structures for adequate fiber optics positioning. Microchannels ended with these meniscuses have been filled with standard SU-8 to obtain 3D microlenses. Agreement between theory and experimental results allows confirming the validity of the proposed technology.

Micro-scale metallization on flexible polyimide substrate by Cu electroplating using SU-8 photoresist mask

International Nuclear Information System (INIS)

Cho, S.H.; Kim, S.H.; Lee, N.-E.; Kim, H.M.; Nam, Y.W.

2005-01-01

Technologies for flexible electronics have been developed to make electronic or microelectromechanical (MEMS) devices on inexpensive and flexible organic substrates. In order to fabricate the interconnect lines between device elements or layers in flexible electronic devices, metallization on the flexible substrate is essential. In this case, the width and conductivity of metallization line are very important for minimizing the size of device. Therefore, the realization of metallization process with the scale of a few micrometers on the flexible substrate is required. In this work, micro-scale metallization lines of Cu were fabricated on the flexible substrate by electroplating using the patterned mask of a negative-tone SU-8 photoresist. Polyimide surface was treated by O 2 /Ar atmospheric plasma for the improvement in adhesion between Cr layer and polyimide and in situ sputter deposition of 100-nm-thick Cu seed layers on the sputter-deposited 50-nm-thick Cr adhesion layer was followed. SU-8 photoresist was spin-coated and patterned by photolithography. Electroplating of Cu line, removal of SU-8, and selective wet etch of Cr adhesion and Cu seed layers were carried out. Gap between the Cu lines was successfully filled by spin-coating of polyimide. Micro-scale Cu metal lines with gap filling on the polyimide substrate with a thickness of 6-12 μm and an aspect ratio of 1-3 were successfully fabricated

The conserved His8 of the Moloney murine leukemia virus Env SU subunit directs the activity of the SU-TM disulphide bond isomerase

International Nuclear Information System (INIS)

Li Kejun; Zhang, Shujing; Kronqvist, Malin; Ekstroem, Maria; Wallin, Michael; Garoff, Henrik

2007-01-01

Murine leukemia virus (MLV) fusion is controlled by isomerization of the disulphide bond between the receptor-binding surface (SU) and fusion-active transmembrane subunits of the Env-complex. The bond is in SU linked to a CXXC motif. This carries a free thiol that upon receptor binding can be activated (ionized) to attack the disulphide and rearrange it into a disulphide isomer within the motif. To find out whether His8 in the conserved SPHQ sequence of Env directs thiol activation, we analyzed its ionization in MLV vectors with wtEnv and Env with His8 deleted or substituted for Tyr or Arg, which partially or completely arrests fusion. The ionization was monitored by following the pH effect on isomerization in vitro by Ca 2+ depletion or in vivo by receptor binding. We found that wtEnv isomerized optimally at slightly basic pH whereas the partially active mutant required higher and the inactive mutants still higher pH. This suggests that His8 directs the ionization of the CXXC thiol

Mass anomalous dimension of SU(2) with Nf=8 using the spectral density method

DEFF Research Database (Denmark)

Suorsa, Joni M.; Leino, Viljami; Rantaharju, Jarno

2015-01-01

SU(2) with Nf=8 is believed to have an infrared conformal fixed point. We use the spectral density method to evaluate the coupling constant dependence of the mass anomalous dimension for massless HEX smeared, clover improved Wilson fermions with Schr\\"odinger functional boundary conditions....

Fabrication of SU-8 low frequency electrostatic energy harvester

KAUST Repository

Ramadan, Khaled S.

2011-11-01

A 1500μm × 1500μm × 150μm out-of-plane, gap closing, electrostatic energy harvester is designed and fabricated to harvest low-frequency ambient vibrations. SU-8 is used to fabricate the proof mass (1200μm × 1200μm × 150μm) and the 5 m springs. Different harvesters were designed to harvest at 50, 75 and 110 Hz. At 110 Hz, Simulations show that with an input vibration of 10 μm amplitude at the frequency of resonance of the structure, the energy harvester should generate an average output power density of 0.032μW/mm3. This is the most area-efficient low-frequency electrostatic harvester to-date. © 2011 IEEE.

Inkjet Printing of High Aspect Ratio Superparamagnetic SU-8 Microstructures with Preferential Magnetic Directions

Directory of Open Access Journals (Sweden)

Loïc Jacot-Descombes

2014-08-01

Full Text Available Structuring SU-8 based superparamagnetic polymer composite (SPMPC containing Fe3O4 nanoparticles by photolithography is limited in thickness due to light absorption by the nanoparticles. Hence, obtaining thicker structures requires alternative processing techniques. This paper presents a method based on inkjet printing and thermal curing for the fabrication of much thicker hemispherical microstructures of SPMPC. The microstructures are fabricated by inkjet printing the nanoparticle-doped SU-8 onto flat substrates functionalized to reduce the surface energy and thus the wetting. The thickness and the aspect ratio of the printed structures are further increased by printing the composite onto substrates with confinement pedestals. Fully crosslinked microstructures with a thickness up to 88.8 μm and edge angle of 112° ± 4° are obtained. Manipulation of the microstructures by an external field is enabled by creating lines of densely aggregated nanoparticles inside the composite. To this end, the printed microstructures are placed within an external magnetic field directly before crosslinking inducing the aggregation of dense Fe3O4 nanoparticle lines with in-plane and out-of-plane directions.

Optimized plasma-deposited fluorocarbon coating for dry release and passivation of thin SU-8 cantilevers

DEFF Research Database (Denmark)

Keller, Stephan Urs; Häfliger, Daniel; Boisen, Anja

2008-01-01

during fluorocarbon deposition, the surface free energy of the coating can be tuned to allow for uniform wetting during spin coating of arbitrary thin SU-8 films. Further, they define an optimal pressure regime for the release of thin polymer structures at high yield. They demonstrate the successful......Plasma-deposited fluorocarbon coatings are introduced as a convenient method for the dry release of polymer structures. In this method, the passivation process in a deep reactive ion etch reactor was used to deposit hydrophobic fluorocarbon films. Standard photolithography with the negative epoxy......-based photoresist SU-8 was used to fabricate polymer structures such as cantilevers and membranes on top of the nonadhesive release layer. The authors identify the plasma density as the main parameter determining the surface properties of the deposited fluorocarbon films. They show that by modifying the pressure...

Interview: Sued-Chemie innovates to maintain its leadership; Interview Sued-Chemie: innover pour conserver son leadership

Energy Technology Data Exchange (ETDEWEB)

Anon.

2000-01-01

The Sued-Chemie group, the head office of which is based in Munich, is one of the world's leading producers of catalysts for the 'syngas' gas chemistry, the refining and the petrochemical industry. Questioned by Info Chimie Magazine, Stefan Brejc, the Product Manager for 'syngas' catalysts, reviews the products in the range. (authors)

Optimized piranha etching process for SU8-based MEMS and MOEMS construction

OpenAIRE

Holmes, Matthew; Keeley, Jared; Hurd, Katherine; Schmidt, Holger; Hawkins, Aaron

2010-01-01

We demonstrate the optimization of the concentration, temperature and cycling of a piranha (H2O2:H2SO4) mixture that produces high yields while quickly etching hollow structures made using a highly crosslinked SU8 polymer sacrificial core. The effects of the piranha mixture on the thickness, refractive index and roughness of common micro-electromechanical systems and micro-opto-electromechanical systems fabrication materials (SiN, SiO2 and Si) were determined. The effectiveness of the optimal...

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

International Nuclear Information System (INIS)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Shozo; Namazu, Takahiro; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu

2013-01-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O 2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O 2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively. (paper)

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

Science.gov (United States)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu; Inoue, Shozo; Namazu, Takahiro

2013-10-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively.

Optimized piranha etching process for SU8-based MEMS and MOEMS construction

International Nuclear Information System (INIS)

Holmes, Matthew; Keeley, Jared; Hurd, Katherine; Hawkins, Aaron; Schmidt, Holger

2010-01-01

We demonstrate the optimization of the concentration, temperature and cycling of a piranha (H 2 O 2 :H 2 SO 4 ) mixture that produces high yields while quickly etching hollow structures made using a highly crosslinked SU8 polymer sacrificial core. The effects of the piranha mixture on the thickness, refractive index and roughness of common micro-electromechanical systems and micro-opto-electromechanical systems fabrication materials (SiN, SiO 2 and Si) were determined. The effectiveness of the optimal piranha mixture was demonstrated in the construction of hollow anti-resonant reflecting optical waveguides

Optimized piranha etching process for SU8-based MEMS and MOEMS construction

Science.gov (United States)

Holmes, Matthew; Keeley, Jared; Hurd, Katherine; Schmidt, Holger; Hawkins, Aaron

2010-11-01

We demonstrate the optimization of the concentration, temperature and cycling of a piranha (H2O2:H2SO4) mixture that produces high yields while quickly etching hollow structures made using a highly crosslinked SU8 polymer sacrificial core. The effects of the piranha mixture on the thickness, refractive index and roughness of common micro-electromechanical systems and micro-opto-electromechanical systems fabrication materials (SiN, SiO2 and Si) were determined. The effectiveness of the optimal piranha mixture was demonstrated in the construction of hollow anti-resonant reflecting optical waveguides.

An isotropic suspension system for a biaxial accelerometer using electroplated thick metal with a HAR SU-8 mold

International Nuclear Information System (INIS)

Lee, Jin Seung; Lee, Seung S

2008-01-01

In this paper, a novel approach is developed to design an isotropic suspension system using thick metal freestanding micro-structures combining bulk micro-machining with electroplating based on a HAR SU-8 mold. An omega-shape isotropic suspension system composed of circular curved beams that have free switching of imaginary boundary conditions is proposed. This novel isotropic suspension design is not affected by geometric dimensional parameters and always achieves matching stiffness along the principle axes of elasticity. Using the finite element method, the isotropic suspension system was compared with an S-shaped meandering suspension system. In order to realize the suggested isotropic suspension system, a cost-effective fabrication process using electroplating with the SU-8 mold was developed to avoid expensive equipment and materials such as deep reactive-ion etching (DRIE) or a silicon-on-insulator (SOI) wafer. The fabricated isotropic suspension system was verified by electromagnetic actuation experiments. Finally, a biaxial accelerometer with isotropic suspension system was realized and tested using a vibration generator system. The proposed isotropic suspension system and the modified surface micro-machining technique based on electroplating with an SU-8 mold can contribute towards minimizing the system size, simplifying the system configuration, reducing the system price of and facilitating mass production of various types of low-cost sensors and actuators

SU-8 Based MEMS Process with Two Metal Layers using α-Si as a Sacrificial Material

KAUST Repository

Ramadan, Khaled S.

2012-01-01

MEMS applications. α-Si can be deposited at large thicknesses for MEMS applications and also can be released in a dry method using XeF2 which can solve stiction problems related to MEMS applications. In this thesis, an SU-8 MEMS process is developed

Supersymmetric flipped SU(5) revitalized

Energy Technology Data Exchange (ETDEWEB)

Antoniadis, I.; Ellis, J.; Hagelin, J.S.; Nanopoulos, D.V.

1987-08-06

We describe a simple N = 1 supersymmetric GUT based on the group SU(5) x U(1) which has the following virtues: the gauge group is broken down to the SU(3)/sub C/ x SU(2)/sub L/ x U(1)/sub y/ of the standard model using just 10, 10 Higgs representations, and the doublet-triplet mass splitting problem is solved naturally by a very simple missing-partner mechanism. The successful supersymmetric GUT prediction for sin/sup 2/theta/sub w/ can be maintained, whilst there are no fermion mass relations. The gauge group and representation structure of the model may be obtainable from the superstring.

High temperature SU-8 pyrolysis for fabrication of carbon electrodes

DEFF Research Database (Denmark)

Hassan, Yasmin Mohamed; Caviglia, Claudia; Hemanth, Suhith

2017-01-01

In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central...... composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance...... spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon. The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis...

Comparison of three different scales techniques for the dynamic mechanical characterization of two polymers (PDMS and SU8)

Science.gov (United States)

Le Rouzic, J.; Delobelle, P.; Vairac, P.; Cretin, B.

2009-10-01

In this article the dynamic mechanical characterization of PDMS and SU8 resin using dynamic mechanical analysis, nanoindentation and the scanning microdeformation microscope have been presented. The methods are hereby explained, extended for viscoelastic behaviours, and their compatibility underlined. The storage and loss moduli of these polymers over a wide range of frequencies (from 0.01 Hz to somekHz) have been measured. These techniques are shown fairly matching and the two different viscoelastic behaviours of these two polymers have been exhibited. Indeed, PDMS shows moduli which still increase at 5kHz whereas SU8 ones decrease much sooner. From a material point of view, the Havriliak and Negami model to estimate instantaneous, relaxed moduli and time constant of these materials has been identified.

Microfabrication of pre-aligned fiber bundle couplers using ultraviolet lithography of SU-8

OpenAIRE

Yang, Ren; Soper, Steven A.; Wang, Wanjun

2006-01-01

This paper describes the design, microfabrication and testing of a pre-aligned array of fiber couplers using direct UV-lithography of SU-8. The fiber coupler array includes an out-of-plane refractive microlens array and two fiberport collimator arrays. With the optical axis of the pixels parallel to the substrate, each pixel of the microlens array can be pre-aligned with the corresponding pixels of the fiberport collimator array as defined by the lithography mask design. This out-of-plane pol...

Effect of size and moisture on the mechanical behavior of SU-8 thin films

International Nuclear Information System (INIS)

Robin, C J; Jonnalagadda, K N

2016-01-01

The mechanical properties of SU-8 were investigated in conjunction with size effect, mechanical anisotropy and moisture absorption. Uniaxial tensile experiments were conducted on SU-8 films of 500 nm and 2 μm thickness. A spin coating process was used to fabricate the films with one set from a single coat (single layer) and the others containing multiple coats (multilayer) with pre-baking in between. The stress versus strain response was obtained from in situ optical experiments and a digital image correlation method. Compared to single layer films, the multilayer films showed a significant increase in mechanical properties as well as in-plane anisotropy. This anisotropy was confirmed using Fourier transform infrared spectroscopy and attributed to the spin coating process, which resulted in higher crosslinking density in the film, and molecular orientation in the radial direction. Moisture absorption studies revealed that the mechanical properties were affected by water, which exists in both the free and bonded form in the polymer and acts as a plasticizer. The effect of moisture was similar in both the single and multilayer films, but was higher for the latter due to multiple processing steps as well as the existence of higher percentage of epoxy polar groups. (paper)

Effect of size and moisture on the mechanical behavior of SU-8 thin films

Science.gov (United States)

Robin, C. J.; Jonnalagadda, K. N.

2016-02-01

The mechanical properties of SU-8 were investigated in conjunction with size effect, mechanical anisotropy and moisture absorption. Uniaxial tensile experiments were conducted on SU-8 films of 500 nm and 2 μm thickness. A spin coating process was used to fabricate the films with one set from a single coat (single layer) and the others containing multiple coats (multilayer) with pre-baking in between. The stress versus strain response was obtained from in situ optical experiments and a digital image correlation method. Compared to single layer films, the multilayer films showed a significant increase in mechanical properties as well as in-plane anisotropy. This anisotropy was confirmed using Fourier transform infrared spectroscopy and attributed to the spin coating process, which resulted in higher crosslinking density in the film, and molecular orientation in the radial direction. Moisture absorption studies revealed that the mechanical properties were affected by water, which exists in both the free and bonded form in the polymer and acts as a plasticizer. The effect of moisture was similar in both the single and multilayer films, but was higher for the latter due to multiple processing steps as well as the existence of higher percentage of epoxy polar groups.

Fermion unification model based on the intrinsic SU(8 symmetry of a generalized Dirac equation

Directory of Open Access Journals (Sweden)

Eckart eMarsch

2015-10-01

Full Text Available A natural generalization of the original Dirac spinor into a multi-component spinor is achieved, which corresponds to the single lepton and the three quarks of the first family of the standard model of elementary particle physics. Different fermions result from similarity transformations of the Dirac equation, but apparently there can be no more fermions according to the maximal multiplicity revealed in this study. Rotations in the fermion state space are achieved by the unitary generators of the U(1 and the SU(3 groups, corresponding to quantum electrodynamics (QED based on electric charge and chromodynamics (QCD based on colour charge. In addition to hypercharge the dual degree of freedom of hyperspin emerges, which occurs due to the duplicity implied by the two related (Weyl and Dirac representations of the Dirac equation. This yields the SU(2 symmetry of the weak interaction, which can be married to U(1 to generate the unified electroweak interaction as in the standard model. Therefore, the symmetry group encompassing all the three groups mentioned above is SU(8, which can accommodate and unify the observed eight basic stable fermions.

Hydrophobic coating of microfluidic chips structured by SU-8 polymer for segmented flow operation

International Nuclear Information System (INIS)

Schumacher, J T; Grodrian, A; Metze, J; Kremin, C; Hoffmann, M

2008-01-01

We present a hydrophobization procedure for SU-8-based microfluidic chips on borofloat substrates. Different layouts of gold electrodes passivated by the polymer have been investigated. The chips are used for segmented flow in a two-fluid mode that requires a distinct hydrophobicity of the channel walls which is generated by the use of specific silane. In this paper we describe the production and silanization of the chips and demonstrate segmented flow operation

Paper Microzone Plates as Analytical Tools for Studying Enzyme Stability: A Case Study on the Stabilization of Horseradish Peroxidase Using Trehalose and SU-8 Epoxy Novolac Resin.

Science.gov (United States)

Ganaja, Kirsten A; Chaplan, Cory A; Zhang, Jingyi; Martinez, Nathaniel W; Martinez, Andres W

2017-05-16

Paper microzone plates in combination with a noncontact liquid handling robot were demonstrated as tools for studying the stability of enzymes stored on paper. The effect of trehalose and SU-8 epoxy novolac resin (SU-8) on the stability of horseradish peroxidase (HRP) was studied in both a short-term experiment, where the activity of various concentrations of HRP dried on paper were measured after 1 h, and a long-term experiment, where the activity of a single concentration of HRP dried and stored on paper was monitored for 61 days. SU-8 was found to stabilize HRP up to 35 times more than trehalose in the short-term experiment for comparable concentrations of the two reagents, and a 1% SU-8 solution was found to stabilize HRP approximately 2 times more than a 34% trehalose solution in both short- and long-term experiments. The results suggest that SU-8 is a promising candidate for use as an enzyme-stabilizing reagent for paper-based diagnostic devices and that the short-term experiment could be used to quickly evaluate the capacity of various reagents for stabilizing enzymes to identify and characterize new enzyme-stabilizing reagents.

Surface modification of SU-8 for metal/SU-8 adhesion using RF plasma treatment for application in thermopile detectors

International Nuclear Information System (INIS)

Ashraf, Shakeel; Mattsson, Claes G; Thungström, Göran; Fondell, Mattis; Lindblad, Andreas

2015-01-01

This article reports on plasma treatment of SU-8 epoxy in order to enhance adhesive strength for metals. Its samples were fabricated on standard silicon wafers and treated with (O 2 and Ar) RF plasma at a power of 25 W at a low pressure of (3 × 10 −3 Torr) for different time spans (10–70 s). The sample surfaces were characterized in terms of contact angle, surface (roughness and chemistry) and using a tape test. During the contact angle measurement, it was observed that the contact angle was reduced from 73° to 5° (almost wet) and 23° for (O 2 and Ar) treated samples, respectively. The root mean square surface roughness was significantly increased by 21.5% and 37.2% for (O 2 and Ar) treatment, respectively. A pattern of metal squares was formed on the samples using photolithography for a tape test. An adhesive tape was applied to the samples and peeled off at 180°. The maximum adhesion results, more than 90%, were achieved for the O 2 -treated samples, whereas the Ar-treated samples showed no change. The XPS study shows the formation of new species in the O 2 -treated sample compared to the Ar-treated samples. The high adhesive results were due to the formation of hydrophilic groups and new O 2 species in the O 2 -treated samples, which were absent in Ar-treated samples. (paper)

Refractive index modulation of SU-8 polymer optical waveguides by means of hybrid photothermal process

OpenAIRE

Salazar-Miranda, D.; Castillón, F. F.; Sánchez-Sánchez, J. J.; Angel-Valenzuela, J. L.; Márquez, H.

2010-01-01

This paper describes the fabrication and characterization of multimode polymer optical waveguides obtained using a SU-8-2005 polymer by means of photolithographic process. Critical information about refractive index modulation of polymer waveguides as function of fabrication parameters as pre-baked and ultraviolet exposure times is presented. Physical properties of the waveguides were determined by means prism-coupling technique, optical and SEM microscopy. Este trabajo describe la fabrica...

Deep proton writing of high aspect ratio SU-8 micro-pillars on glass

Energy Technology Data Exchange (ETDEWEB)

Ebraert, Evert, E-mail: eebraert@b-phot.org; Rwamucyo, Ben; Thienpont, Hugo; Van Erps, Jürgen

2016-12-15

Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer micro-structures. We use SU-8, a negative resist, spincoated in a layer up to 720 μm-thick in a single step on borosilicate glass, for irradiation with a collimated 12 MeV energy proton beam. Micro-pillars with a slightly conical profile are irradiated in the SU-8 layer. We determine the optimal proton fluence to be 1.02 × 10{sup 4} μm{sup −2}, with which we are able to repeatably achieve micro-pillars with a top-diameter of 138 ± 1 μm and a bottom-diameter of 151 ± 3 μm. The smallest fabricated pillars have a top-diameter of 57 ± 5 μm. We achieved a root-mean-square sidewall surface roughness between 19 nm and 35 nm for the fabricated micro-pillars, measured over an area of 5 × 63.7 μm. We briefly discuss initial testing of two potential applications of the fabricated micro-pillars. Using ∼100 μm-diameter pillars as waveguides for gigascale integration optical interconnect applications, has shown a 4.7 dB improvement in optical multimode fiber-to-fiber coupling as compared to the case where an air–gap is present between the fibers at the telecom wavelength of 1550 nm. The ∼140 μm-diameter pillars were used for mold fabrication with silicone casting. The resulting mold can be used for hydrogel casting, to obtain hydrogel replicas mimicking human tissue for in vitro bio-chemical applications.

Investigation of a novel approach for the cross-linking characterization of SU-8 photoresist materials by means of optical dispersion measurements

Science.gov (United States)

Taudt, Ch.; Baselt, T.; Koch, E.; Hartmann, P.

2014-03-01

The increase in efficiency and precision in the production of semiconductor structures under the use of polymeric materials like SU-8 is crucial in securing the technological innovation within this industry. The manufacturing of structures on wafers demands a high quality of materials, tools and production processes. In particular, deviations in the materials' parameters (e.g. cross-linking state, density or mechanical properties) could lead to subsequent problems such as a reduced lifetime of structures and systems. In particular problems during the soft and post-exposure bake process can lead to an inhomogeneous distribution of material properties. This paper describes a novel approach for the characterization of SU-8 material properties in relation to a second epoxy-based material of different cross-linking by the measurement of optical dispersion within the material. A white-light interferometer was used. In particular the setup consisted of a white-light source, a Michelson-type interferometer and a spectrometer. The investigation of the dispersion characteristics was carried out by the detection of the equalization wavelength for different positions of the reference arm in a range from 400 to 900 nm. The measured time delay due to dispersion ranges from 850 to 1050 ps/m. For evaluation purposes a 200μm SU-8 sample was characterized in the described setup regarding its dispersion characteristics in relation to bulk epoxy material. The novel measurement approach allowed a fast and high-resolution material characterization for SU-8 micro structures which was suitable for integration in production lines. The outlook takes modifications of the experimental setup regarding on-wafer measurements into account.

Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

KAUST Repository

Ramadan, Khaled S.; Nasr, Tarek Adel Hosny; Foulds, Ian G.

2013-01-01

method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using ;-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow

Focusing properties of x-ray polymer refractive lenses from SU-8 resist layer

Science.gov (United States)

Snigirev, Anatoly A.; Snigireva, Irina; Drakopoulos, Michael; Nazmov, Vladimir; Reznikova, Elena; Kuznetsov, Sergey; Grigoriev, Maxim; Mohr, Jurgen; Saile, Volker

2003-12-01

Compound refractive lenses printed in Al and Be are becoming the key X-ray focusing and imaging components of beamline optical layouts at the 3rd generation synchrotron radiation sources. Recently proposed planar optical elements based on Si, diamond etc. may substantially broaden the spectrum of the refractive optics applicability. Planar optics has focal distances ranging from millimeters to tens of meters offering nano- and micro-focusing lenses, as well as beam condensers and collimators. Here we promote deep X-ray lithography and LIGA-type techniques to create high aspect-ratio lens structures for different optical geometries. Planar X-ray refractive lenses were manufactured in 1 mm thick SU-8 negative resist layer by means of deep synchrotron radiation lithography. The focusing properties of lenses were studied at ID18F and BM5 beamlines at the ESRF using monochromatic radiation in the energy range of 10 - 25 keV. By optimizing lens layout, mask making and resist processing, lenses of good quality were fabricated. The resolution of about 270 nm (FWHM) with gain in the order of 300 was measured at 14 keV. In-line holography of B-fiber was realized in imaging and projection mode with a magnification of 3 and 20, respectively. Submicron features of the fiber were clearly resolved. A radiation stability test proved that the fabricated lenses don't change focusing characteristics after dose of absorbed X-ray radiation of about 2 MJ/cm3. The unique radiation stability along with the high effficiency of SU8 lenses opens wide range of their synchrotron radiation applications such as microfocusing elements, condensers and collimators.

Large-core single-mode rib SU8 waveguide using solvent-assisted microcontact molding.

Science.gov (United States)

Huang, Cheng-Sheng; Wang, Wei-Chih

2008-09-01

This paper describes a novel fabrication technique for constructing a polymer-based large-core single-mode rib waveguide. A negative tone SU8 photoresist with a high optical transmission over a large wavelength range and stable mechanical properties was used as a waveguide material. A waveguide was constructed by using a polydimethylsiloxane stamp combined with a solvent-assisted microcontact molding technique. The effects on the final pattern's geometry of four different process conditions were investigated. Optical simulations were performed using beam propagation method software. Single-mode beam propagation was observed at the output of the simulated waveguide as well as the actual waveguide through the microscope image.

Heterogeneous integration of thin film compound semiconductor lasers and SU8 waveguides on SiO2/Si

Science.gov (United States)

Palit, Sabarni; Kirch, Jeremy; Mawst, Luke; Kuech, Thomas; Jokerst, Nan Marie

2010-02-01

We present the heterogeneous integration of a 3.8 μm thick InGaAs/GaAs edge emitting laser that was metal-metal bonded to SiO2/Si and end-fire coupled into a 2.8 μm thick tapered SU8 polymer waveguide integrated on the same substrate. The system was driven in pulsed mode and the waveguide output was captured on an IR imaging array to characterize the mode. The waveguide output was also coupled into a multimode fiber, and into an optical head and spectrum analyzer, indicating lasing at ~997 nm and a threshold current density of 250 A/cm2.

8x8 and 10x10 Hyperspace Representations of SU(3) and 10-fold Point-Symmetry Group of Quasicrystals

Science.gov (United States)

Animalu, Alexander

2012-02-01

In order to further elucidate the unexpected 10-fold point-symmetry group structure of quasi-crystals for which the 2011 Nobel Prize in chemistry was awarded to Daniel Shechtman, we explore a correspondence principle between the number of (projective) geometric elements (points[vertices] + lines[edges] + planes[faces]) of primitive cells of periodic or quasi-periodic arrangement of hard or deformable spheres in 3-dimensional space of crystallography and elements of quantum field theory of particle physics [points ( particles, lines ( particles, planes ( currents] and hence construct 8x8 =64 = 28+36 = 26 + 38, and 10x10 =100= 64 + 36 = 74 + 26 hyperspace representations of the SU(3) symmetry of elementary particle physics and quasicrystals of condensed matter (solid state) physics respectively, As a result, we predict the Cabibbo-like angles in leptonic decay of hadrons in elementary-particle physics and the observed 10-fold symmetric diffraction pattern of quasi-crystals.

Microencapsulation Technologies for Corrosion Protective Coating Applications

Science.gov (United States)

Li, Wenyan; Buhrow, Jerry; Jolley, Scott; Calle, Luz; Pearman, Benjamin; Zhang, Xuejun

2015-01-01

Microencapsulation technologies for functional smart Coatings for autonomous corrosion control have been a research area of strong emphasis during the last decade. This work concerns the development of pH sensitive micro-containers (microparticles and microcapsules) for autonomous corrosion control. This paper presents an overview of the state-of-the-art in the field of microencapsulation for corrosion control applications, as well as the technical details of the pH sensitive microcontainer approach, such as selection criteria for corrosion indicators and corrosion inhibitors; the development and optimization of encapsulation methods; function evaluation before and after incorporation of the microcontainers into coatings; and further optimization to improve coating compatibility and performance.

UTC(SU) and EOP(SU) - the only legal reference frames of Russian Federation

Science.gov (United States)

Koshelyaevsky, Nikolay B.; Blinov, Igor Yu; Pasynok, Sergey L.

2015-08-01

There are two legal time reference frames in Russian Federation. UTC(SU) deals with atomic time and play a role of reference for legal timing through the whole country. The other one, EOP(SU), deals with Earth's orientation parameters and provides the official EOP data for scientific, technical and metrological applications in Russia.The atomic time is based on two essential hardware components: primary Cs fountain standards and ensemble of continuously operating H-masers as a time unit/time scale keeper. Basing on H-maser intercomparison system data, regular H-maser frequency calibration against Cs standards and time algorithm autonomous TA(SU) time scale is maintained by the Main Metrological Center. Since 2013 time unit in TA(SU) is the second (SU) reproduced independently by VNIIFTRI Cs primary standards in accordance to it’s definition in the SI. UTC(SU) is relied on TA(SU) and steering to UTC basing on TWSTFT/GNSS time link data. As a result TA(SU) stability level relative to TT considerably exceeds 1×10-15 for sample time one month and more, RMS[UTC-UTC(SU)] ≤ 3 ns for the period of 2013-2015. UTC(SU) is broadcasted by different national means such as specialized radio and TV stations, NTP servers and GLONASS. Signals of Russian radio stations contains DUT1 and dUT1 values at 0.1s and 0.02s resolution respectively.The definitive EOP(SU) are calculated by the Main Metrological Center basing on composition of the eight independent individual EOP data streams delivered by four Russian analysis centers: VNIIFTRI, Institute of Applied Astronomy, Information-Analytical Center of Russian Space Agency and Analysis Center of Russian Space Agency. The accuracy of ultra-rapid EOP values for 2014 is estimated ≤ 0.0006" for polar motion, ≤ 70 microseconds for UT1-UTC and ≤ 0.0003" for celestial pole offsets respectively.The other VNIIFTRI EOP activities can be grouped in three basic directions:- arrangement and carrying out GNSS and SLR observations at five

Simulation of a low frequency Z-axis SU-8 accelerometer in coventorware and MEMS+

KAUST Repository

Carreno, Armando Arpys Arevalo

2013-04-01

This paper presents the simulation of a z-axis SU-8 capacitive accelerometer. The study consists of a modal analysis of the modeled accelerometer, a study relating capacitance to acceleration, capacitance to deflection, an effective spring constant calculation, and a comparison of results achieved using CoventorWare® ANALYZER™ and MEMS+®. A fabricated energy harvester design from [1] was used for modeling and simulation in this study, with a four spring attachment of a 650μm×650μm; ×110μm proof mass of 4.542×10-8 kg. At rest, the spacing between electrodes is 4μm along the z-axis, and at 1.5g acceleration, there is 1.9μm spacing between electrodes, at which point pull in occurs for a 1V voltage. © 2013 IEEE.

B8B8 interaction in the SU6 quark model and its applications to few-body systems

International Nuclear Information System (INIS)

Fujiwara, Y.; Miyagawa, K.; Kohno, M.; Suzuki, Y.; Nakamoto, C.

2004-01-01

The recent QCD-inspired spin-flavor SU 6 quark model for the baryon-baryon interaction, proposed by the Kyoto-Niigata group, is a unified model for the complete baryon octet (B 8 =N, Λ, Σ and Ξ), which has achieved very accurate description of the NN and YN interactions. These quark-model interactions are now applied to realistic calculations of few-body systems in a new three-cluster Faddeev formalism which uses the 2-cluster resonating-group method kernel explicitly. We review the essential features of the most recent models, fss2 and FSS, and their predictions to few-body systems in confrontation with the available experimental data. As the few-body systems, we discuss the three-nucleon bound states, 2αΛ system for Λ 9 Be, and 2Λα system for ΛΛ 6 He. (author)

SU(3) chiral symmetry for baryons

International Nuclear Information System (INIS)

Dmitrasinovic, V.

2011-01-01

Three-quark nucleon interpolating fields in QCD have well-defined SU L (3)xSU R (3) and U A (1) chiral transformation properties, viz. [(6,3)+(3,6)], [(3,3-bar)+(3-bar,3)], [(8,1)+(1,8)] and their 'mirror' images. It has been shown (phenomenologically) in Ref. [2] that mixing of the [(6,3)+(3,6)] chiral multiplet with one ordinary ('naive') and one 'mirror' field belonging to the [(3,3-bar)+(3-bar,3)], [(8,1)+(1,8)] multiplets can be used to fit the values of the isovector (g A (3) ) and the flavor-singlet (isoscalar) axial coupling (g A (0) ) of the nucleon and then predict the axial F and D coefficients, or vice versa, in reasonable agreement with experiment. In an attempt to derive such mixing from an effective Lagrangian, we construct all SU L (3)xSU R (3) chirally invariant non-derivative one-meson-baryon interactions and then calculate the mixing angles in terms of baryons' masses. It turns out that there are (strong) selection rules: for example, there is only one non-derivative chirally symmetric interaction between J 1/2 fields belonging to the [(6,3)+(3,6)] and the [(3,3-bar)+(3-bar,3)] chiral multiplets, that is also U A (1) symmetric. We also study the chiral interactions of the [(3,3-bar)+(3-bar,3)] and [(8,1)+(1,8)] nucleon fields. Again, there are selection rules that allow only one off-diagonal non-derivative chiral SU L (3)xSU R (3) interaction of this type, that also explicitly breaks the U A (1) symmetry. We use this interaction to calculate the corresponding mixing angles in terms of baryon masses and fit two lowest lying observed nucleon (resonance) masses, thus predicting the third (J = 1/2, I = 3/2)Δ resonance, as well as one or two flavor-singlet Λ hyperon(s), depending on the type of mixing. The effective chiral Lagrangians derived here may be applied to high density matter calculations.

Thin film free-standing PEDOT:PSS/SU8 bilayer microactuators

International Nuclear Information System (INIS)

Taccola, S; Greco, F; Mazzolai, B; Mattoli, V; Jager, E W H

2013-01-01

Several smart active materials have been proposed and tested for the development of microactuators. Among these, conjugated polymers are of great interest because miniaturization improves their electrochemical properties, such as increasing the speed and stress output of microactuators, with respect to large-scale actuators. Recently we developed a novel fabrication process to obtain robust free-standing conductive ultra-thin films made of the conjugated polymer poly(3, 4-ethylenedioxythiophene) doped with the polyanion poly(styrenesulfonate) (PEDOT:PSS). These conductive free-standing nanofilms, with thicknesses ranging between a few tens to several hundreds of nm, allow the realisation of new all polymer microactuators using facile microfabrication methods. Here, we report a novel processing method for manufacturing all polymer electrochemical microactuators. We fabricated and patterned free-standing PEDOT:PSS/SU8 bilayer microactuators in the form of microfingers of a variety of lengths using adapted microfabrication procedures. By imposing electrochemical oxidation/reduction cycles on the PEDOT:PSS we were able to demonstrate reversible actuation of the microactuators resulting in bending of the microfingers. A number of possible applications can be envisaged for these small, soft actuators, such as microrobotics and cell manipulation. (technical note)

A high aspect ratio SU-8 fabrication technique for hollow microneedles for transdermal drug delivery and blood extraction

Science.gov (United States)

Chaudhri, Buddhadev Paul; Ceyssens, Frederik; De Moor, Piet; Van Hoof, Chris; Puers, Robert

2010-06-01

Protein drugs, e.g. hormonal drugs, cannot be delivered orally to a patient as they get digested in the gastro-intestinal (GI) tract. Thus, it is imperative that these kinds of drugs are delivered transdermally through the skin. To provide for real-time feedback as well as to test independently for various substances in the blood, we also need a blood sampling system. Microneedles can perform both these functions. Further, microneedles made of silicon or metal have the risk of breaking inside the skin thereby leading to complications. SU-8, being approved of as being biocompatible by the Food and Drug Agency (FDA) of the United States, is an attractive alternative because firstly it is a polymer material, thereby reducing the chances of breakages inside the skin, and secondly it is a negative photoresist, thereby leading to ease of fabrication. Thus, here we present very tall (around 1600 µm) SU-8 polymer-based hollow microneedles fabricated by a simple and repeatable process, which are a very good candidate for transdermal drug delivery as well as blood extraction. The paper elaborates on the details that allow the fabrication of such extreme aspect ratios (>100).

A high aspect ratio SU-8 fabrication technique for hollow microneedles for transdermal drug delivery and blood extraction

International Nuclear Information System (INIS)

Chaudhri, Buddhadev Paul; Ceyssens, Frederik; Van Hoof, Chris; Puers, Robert; De Moor, Piet

2010-01-01

Protein drugs, e.g. hormonal drugs, cannot be delivered orally to a patient as they get digested in the gastro-intestinal (GI) tract. Thus, it is imperative that these kinds of drugs are delivered transdermally through the skin. To provide for real-time feedback as well as to test independently for various substances in the blood, we also need a blood sampling system. Microneedles can perform both these functions. Further, microneedles made of silicon or metal have the risk of breaking inside the skin thereby leading to complications. SU-8, being approved of as being biocompatible by the Food and Drug Agency (FDA) of the United States, is an attractive alternative because firstly it is a polymer material, thereby reducing the chances of breakages inside the skin, and secondly it is a negative photoresist, thereby leading to ease of fabrication. Thus, here we present very tall (around 1600 µm) SU-8 polymer-based hollow microneedles fabricated by a simple and repeatable process, which are a very good candidate for transdermal drug delivery as well as blood extraction. The paper elaborates on the details that allow the fabrication of such extreme aspect ratios (>100).

Coleman-Weinberg symmetry breaking in SU(8) induced by a third rank antisymmetric tensor scalar field II: the fermion spectrum

Science.gov (United States)

Adler, Stephen L.

2017-07-01

We continue our study of Coleman-Weinberg symmetry breaking induced by a third rank antisymmetric tensor scalar, in the context of the SU(8) model (Adler 2014 Int. J. Mod. Phys. A 29 1450130) we proposed earlier. We focus in this paper on qualitative features that will determine whether the model can make contact with the observed particle spectrum. We discuss the mechanism for giving the spin \\frac{3}{2} field a mass by the BEH mechanism, and analyze the remaining massless spin \\frac{1}{2} fermions, the global chiral symmetries, and the running couplings after symmetry breaking. We note that the smallest gluon mass matrix eigenvalue has an eigenvector suggestive of U(1) B-L , and conjecture that the theory runs to an infrared fixed point at which there is a massless gluon with 3 to  -1 ratios in generator components. Assuming this, we discuss a mechanism for making contact with the standard model, based on a conjectured asymmetric breaking of Sp(4) to SU(2) subgroups, one of which is the electroweak SU(2), and the other of which is a ‘technicolor’ group that binds the original SU(8) model fermions, which play the role of ‘preons’, into composites. Quarks can emerge as 5 preon composites and leptons as 3 preon composites, with consequent stability of the proton against decay to a single lepton plus a meson. A composite Higgs boson can emerge as a two preon composite. Since anomaly matching for the relevant conserved global symmetry current is not obeyed by three fermion families, emergence of three composite families requires formation of a Goldstone boson with quantum numbers matching this current, which can be a light dark matter candidate.

8D oscillator as a hidden SU(2)-monopole

International Nuclear Information System (INIS)

Mardoyan, L.G.; Sisakyan, A.N.; Ter-Antonyan, V.M.

1998-01-01

In the framework of an analytical approach and with the help of the generalized version of the Hurwitz transformation the five-dimensional SU(2)-monopole model is constructed from the eight-dimensional quantum oscillator. The Clebsch-Gordan expansion stimulated by the space-gauge coupling, the hyperangle and the radial parts of the total wave function, the energy spectrum of the charge-monopole bound system and the corresponding degeneracy are calculated

Study of functional viability of SU-8-based microneedles for neural applications

International Nuclear Information System (INIS)

Fernández, Luis J; Altuna, Ane; Tijero, Maria; Vilares, Roman; Berganzo, Javier; Blanco, F J; Gabriel, Gemma; Villa, Rosa; Rodríguez, Manuel J; Batlle, Montse

2009-01-01

This paper presents the design, fabrication, packaging and first test results of SU-8-based microneedles for neural applications. By the use of photolithography, sputtering and bonding techniques, polymer needles with integrated microchannels and electrodes have been successfully fabricated. The use of photolithography for the patterning of the fluidic channel integrated in the needle allows the design of multiple outlet ports at the needle tip, minimizing the possibility of being blocked by the tissue. Furthermore, the flexibility of the polymer reduces the risk of fracture and tissue damage once the needle is inserted, while it is still rigid enough to allow a perfect insertion into the neural tissue. Fluidic and electric characterization of the microneedles has shown their viability for drug delivery and monitoring in neural applications. First drug delivery tests in ex vivo tissue demonstrated the functional viability of the needle to deliver drugs to precise points. Furthermore, in vivo experiments have demonstrated lower associated damages during insertion than those by stereotaxic standard needles

Bi-directional triplexer with butterfly MMI coupler using SU-8 polymer waveguides

Science.gov (United States)

Mareš, David; Jeřábek, Vítězslav; Prajzler, Václav

2015-01-01

We report about a design of a bi-directional planar optical multiplex/demultiplex filter (triplexer) for the optical part of planar hybrid WDM bi-directional transceiver in fiber-to-the-home (FTTH) PON applications. The triplex lightwave circuit is based on the Epoxy Novolak Resin SU-8 waveguides on the silica-on-silicon substrate with Polymethylmethacrylate cladding layer. The triplexer is comprised of a linear butterfly concept of multimode interference (MMI) coupler separating downstream optical signals of 1490 nm and 1550 nm. For the upstream channel of 1310 nm, an additional directional coupler (DC) is used to add optical signal of 1310 nm propagating in opposite direction. The optical triplexer was designed and optimized using beam propagation method. The insertion losses, crosstalk attenuation, and extinction ratio for all three inputs/outputs were investigated. The intended triplexer was designed using the parameters of the separated DC and MMI filter to approximate the idealized direct connection of both devices.

Single Mode SU8 Polymer Based Mach-Zehnder Interferometer for Bio-Sensing Application

Science.gov (United States)

Boiragi, Indrajit; Kundu, Sushanta; Makkar, Roshan; Chalapathi, Krishnamurthy

2011-10-01

This paper explains the influence of different parameters to the sensitivity of an optical waveguide Mach-Zehnder Interferometer (MZI) for real time detection of biomolecules. The sensing principle is based on the interaction of evanescence field with the biomolecules that get immobilized on sensing arm. The sensitivity has been calculated by varying the sensing window length, wavelength and concentration of bio-analyte. The maximum attainable sensitivity for the preferred design is the order of 10-8 RIU at 840 nm wavelength with a sensing window length of 1cm. All the simulation work has been carried out with Opti-BPMCAD for the optimization of MZI device parameters. The SU8 polymers are used as a core and clad material to fabricate the waveguide. The refractive index of cladding layer is optimized by varying the curing temperature for a fixed time period and the achieved index difference between core and clad is Δn = 0.0151. The fabricated MZI device has been characterized with LASER beam profiler at 840 nm wavelength. This study demonstrates the effectiveness of the different parameter to the sensitivity of a single mode optical waveguide Mach-Zehnder Interferometer for bio-sensing application.

Single mode solid state distributed feedback dye laser fabricated by grey scale electron beam lithography on dye doped SU-8 resist

DEFF Research Database (Denmark)

Balslev, Søren; Rasmussen, Torben; Shi, Peixiong

2005-01-01

We demonstrate grey scale electron beam lithography on functionalized SU-8 resist for fabrication of single mode solid state dye laser devices. The resist is doped with Rhodamine 6G perchlorate and the lasers are based on a first order Bragg grating distributed feedback resonator. The lasers...

Nonlinear numerical analysis and experimental testing for an electrothermal SU-8 microgripper with reduced out-of-plane displacement

Science.gov (United States)

Voicu, Rodica-Cristina; Zandi, Muaiyd Al; Müller, Raluca; Wang, Changhai

2017-11-01

This paper reports the results of numerical nonlinear electro-thermo-mechanical analysis and experimental testing of a polymeric microgripper designed using electrothermal actuators. The simulation work was carried out using a finite element method (FEM) and a commercial software (Coventorware 2014). The biocompatible SU-8 polymer was used as structural material for the fabrication of the microgripper. The metallic micro-heater was encapsulated in the polymeric actuation structures of the microgripper to reduce the undesirable out-of-plane displacement of the microgripper tips, and to electrically isolate the micro-heater, and to reduce the mechanical stress as well as to improve the thermal efficiency. The electro- thermo-mechanical analysis of the actuator considers the nonlinear temperature-dependent properties of the SU-8 polymer and the gold thin film layers used for the micro-heater fabrication. An optical characterisation of the microgripper based on an image tracking approach shows the thermal response and the good repeatability. The average deflection is ~11 µm for an actuation current of ~17 mA. The experimentally obtained tip deflection and the heater temperature at different currents are both shown to be in good agreement with the nonlinear electro-thermo-mechanical simulation results. Finally, we demonstrate the capability of the microgripper by capture and manipulation of cotton fibres.

The Morphology of Silver Layers on SU8 polymers prepared by Electroless Deposition

Science.gov (United States)

Dutta, Aniruddha; Yuan, Biao; Heinrich, Helge; Grabill, Chris; Williams, Henry; Kuebler, Stephen; Bhattacharya, Aniket

2010-03-01

Silver was deposited onto the functionalized surface of polymeric SU-8 where gold nanoparticles (Au-NPs) act as nucleation sites using electroless metallization chemistry. Here we report on the evolution of the nanoscale morphology of deposited Ag studied by Transmission Electron Microscopy (TEM). In TEM of sample cross sections correlations between the original gold and the silver nanoparticles were obtained while plan-view TEM results showed the distribution of nanoparticles on the surface. Scanning TEM with a high-angle annular dark field detector was used to obtain atomic number contrast. The morphology of the deposited Ag was controlled through the presence and absence of gum Arabic. The thickness and height fluctuations of the Ag layer were determined as a function of time and a statistical analysis of the growth process was conducted for the initial deposition periods.

d=8 supergravity

International Nuclear Information System (INIS)

Salam, A.; Sezgin, E.

1984-10-01

SU(2) gauged N=2 supergravity in d=8 is constructed by generalized dimensional reduction of d=11 supergravity on SU(2) group manifold. The relation between the field equations of the d=8 and those of d=11 supergravities is established. As a byproduct of this, it is shown that certain compactifications of d=11 supergravity give rise to anti-de Sitter space-time (AdS)xS 4 or AdSxCP 2 (with or without SU(2) instanton) or AdSxS 2 xS 2 compactifications of d=8 supergravity. The latter two solutions have no supersymmetry, while AdSxS 4 has N=0 or N=1 supersymmetry. (author)

A superhydrophobic chip based on SU-8 photoresist pillars suspended on a silicon nitride membrane

KAUST Repository

Marinaro, Giovanni; Accardo, Angelo; De Angelis, Francesco; Dane, Thomas; Weinhausen, Britta; Burghammer, Manfred; Riekel, Christian

2014-01-01

We developed a new generation of superhydrophobic chips optimized for probing ultrasmall sample quantities by X-ray scattering and fluorescence techniques. The chips are based on thin Si3N4 membranes with a tailored pattern of SU-8 photoresist pillars. Indeed, aqueous solution droplets can be evaporated and concentrated at predefined positions using a non-periodic pillar pattern. We demonstrated quantitatively the deposition and aggregation of gold glyconanoparticles from the evaporation of a nanomolar droplet in a small spot by raster X-ray nanofluorescence. Further, raster nanocrystallography of biological objects such as rod-like tobacco mosaic virus nanoparticles reveals crystalline macro-domain formation composed of highly oriented nanorods. © 2014 the Partner Organisations.

A superhydrophobic chip based on SU-8 photoresist pillars suspended on a silicon nitride membrane

KAUST Repository

Marinaro, Giovanni

2014-07-28

We developed a new generation of superhydrophobic chips optimized for probing ultrasmall sample quantities by X-ray scattering and fluorescence techniques. The chips are based on thin Si3N4 membranes with a tailored pattern of SU-8 photoresist pillars. Indeed, aqueous solution droplets can be evaporated and concentrated at predefined positions using a non-periodic pillar pattern. We demonstrated quantitatively the deposition and aggregation of gold glyconanoparticles from the evaporation of a nanomolar droplet in a small spot by raster X-ray nanofluorescence. Further, raster nanocrystallography of biological objects such as rod-like tobacco mosaic virus nanoparticles reveals crystalline macro-domain formation composed of highly oriented nanorods. © 2014 the Partner Organisations.

Intersecting Branes Flip SU(5)

CERN Document Server

Ellis, Jonathan Richard; Nanopoulos, Dimitri V; Ellis, John

2002-01-01

Within a toroidal orbifold framework, we exhibit intersecting brane-world constructions of flipped SU(5) \\times U(1) GUT models with various numbers of generations, other chiral matter representations and Higgs representations. We exhibit orientifold constructions with integer winding numbers that yield 8 or more conventional SU(5) generations, and orbifold constructions with fractional winding numbers that yield flipped SU(5) \\times U(1) models with just 3 conventional generations. Some of these models have candidates for the 5 and {\\bar 5} Higgs representations needed for electroweak symmetry breaking, but not for the 10 and {\\bar 10} representations needed for GUT symmetry breaking, or vice-versa.

3-dimensional free standing micro-structures by proton beam writing of Su 8-silver nanoParticle polymeric composite

Science.gov (United States)

Igbenehi, H.; Jiguet, S.

2012-09-01

Proton beam lithography a maskless direct-write lithographic technique (well suited for producing 3-Dimensional microstructures in a range of resist and semiconductor materials) is demonstrated as an effective tool in the creation of electrically conductive freestanding micro-structures in an Su 8 + Nano Silver polymer composite. The structures produced show non-ohmic conductivity and fit the percolation theory conduction model of tunneling of separated nanoparticles. Measurements show threshold switching and a change in conductivity of at least 4 orders of magnitude. The predictable range of protons in materials at a given energy is exploited in the creation of high aspect ratio, free standing micro-structures, made from a commercially available SU8 Silver nano-composite (GMC3060 form Gersteltec Inc. a negative tone photo-epoxy with added metallic nano-particles(Silver)) to create films with enhanced electrical properties when exposed and cured. Nano-composite films are directly written on with a finely focused MeV accelerated Proton particle beam. The energy loss of the incident proton beams in the target polymer nano- composite film is concentrated at the end of its range, where damage occurs; changing the chemistry of the nano-composite film via an acid initiated polymerization - creating conduction paths. Changing the energy of the incident beams provide exposed regions with different penetration and damage depth - exploited in the demonstrated cantilever microstructure.

Fabrication of cell container arrays with overlaid surface topographies.

Science.gov (United States)

Truckenmüller, Roman; Giselbrecht, Stefan; Escalante-Marun, Maryana; Groenendijk, Max; Papenburg, Bernke; Rivron, Nicolas; Unadkat, Hemant; Saile, Volker; Subramaniam, Vinod; van den Berg, Albert; van Blitterswijk, Clemens; Wessling, Matthias; de Boer, Jan; Stamatialis, Dimitrios

2012-02-01

This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a micro- or nanoscale. For microthermoforming, we apply a new process on the basis of temporary back moulding of polymer films and use the novel concept of a perforated-sheet-like mould. Thermal micro- or nanoimprinting is applied for prepatterning. The novel cell container arrays are fabricated from polylactic acid (PLA) films. The thin-walled microcontainer structures have the shape of a spherical calotte merging into a hexagonal shape at their upper circumferential edges. In the arrays, the cell containers are arranged densely packed in honeycomb fashion. The inner surfaces of the highly curved container walls are provided with various topographical micro- and nanopatterns. For a first validation of the microcontainer arrays as in vitro cell culture substrates, C2C12 mouse premyoblasts are cultured in containers with microgrooved surfaces and shown to align along the grooves in the three-dimensional film substrates. In future stem-cell-biological and tissue engineering applications, microcontainers fabricated using the proposed technology may act as geometrically defined artificial microenvironments or niches.

Ractopamine levels for finishing barrows maintained in heat stress Níveis de ractopamina para suínos machos castrados em terminação mantidos sob estresse por calor

Directory of Open Access Journals (Sweden)

Josilene Figueiredo Sanches

2010-07-01

Full Text Available The objective of this study was to evaluate performance, quantitative characteristics of carcass, and visceral responses of barrows maintained on heat stress enviroment and fed diets supplemented with ractopamine. It was used 48 animals with initial weight of 67.3 ± 3.8 kg, distributed in a randomized block design with four levels of ractopamine (0, 5, 10 and 20 mg/kg, each one with six replicates with two animals each. The experimental period lasted 28 days. Air temperature was 31.8 ± 2.0ºC, air humidity was 72.6 ± 10.2% and BGHI was 82.7 ± 2.8. Daily feed intake was not affect by the levels of ractopamine but they improved feed conversion and increased daily weight gain and final weight of the animals. The carcass quantitative characteristics were not affected by levels of ractopamine. The weights of the liver and kidneys showed linear increases accordingly to increase of ractopamine levels in the diet whereas weight of other organs and length of small intestine were not affected by supplementation with ractopamine. The optimum level of ractopamine for the best performance of barrows under heat stress is 20 mg/kg and it does not affect the quantitative characteristics of carcass.Avaliaram-se o desempenho, as características quantitativas de carcaça e as respostas viscerais de suínos machos castrados mantidos em ambiente de estresse por calor e alimentados com dietas suplementadas com ractopamina. Foram utilizados 48 animais com peso inicial de 67,3 ± 3,8 kg, distribuídos em delineamento em blocos casualizados, com quatro níveis de ractopamina (0, 5, 10 e 20 mg/kg, cada um com seis repetições de dois animais. O período experimental foi de 28 dias. A temperatura do ar foi de 31,8 ± 2,0ºC, a umidade relativa foi de 72,6 ± 10,2% e índice de temperatura de globo e umidade (ITGU de 82,7 ± 2,8. Os níveis de ractopamina não influenciaram o consumo diário de ração, mas melhoraram a conversão alimentar e aumentaram o ganho di

Laws of trigonometry on SU(3)

International Nuclear Information System (INIS)

Aslaksen, H.

1988-01-01

In this paper we will study triangles in SU(3). The orbit space of congruence classes of triangles in SU(3) has dimension 8. Each corner is made up of a pair of tangent vectors (X,Y), and we consider the 8 functions trX 2 , i trX 3 , trY 2 , i trY 3 , trXY, i trY 2 Y, i trXY 2 , trX 2 Y 2 which are invariant under the full isometry group of SU(3). We show that these 8 corner invariants determine the isometry class of the triangle. We give relations (laws of trigonometry) between the invariants at the different corners, enabling us to determine the invariants at the remaining corners, including the values of the remaining side and angles, if we know one set of corner invariants. The invariants that only depend on one tangent vector we will call side invariants, while those that depend on two tangent vectors will be called angular invariants. For each triangle we then have 6 side invariants and 12 angular invariants. Hence we need 18 - 8 = 10 laws of trigonometry. The basic tool for deriving these laws is a formula expressing tr(exp X exp Y) in terms of the corner invariants

Microchannel-connected SU-8 honeycombs by single-step projection photolithography for positioning cells on silicon oxide nanopillar arrays

International Nuclear Information System (INIS)

Larramendy, Florian; Paul, Oliver; Blatche, Marie Charline; Mazenq, Laurent; Laborde, Adrian; Temple-Boyer, Pierre

2015-01-01

We report on the fabrication, functionalization and testing of SU-8 microstructures for cell culture and positioning over large areas. The microstructure consists of a honeycomb arrangement of cell containers interconnected by microchannels and centered on nanopillar arrays designed for promoting cell positioning. The containers have been dimensioned to trap single cells and, with a height of 50 µm, prevent cells from escaping. The structures are fabricated using a single ultraviolet photolithography exposure with focus depth in the lower part of the SU-8 resist. With optimized process parameters, microchannels of various aspect ratios are thus produced. The cell containers and microchannels serve for the organization of axonal growth between neurons. The roughly 2 µm-high and 500 nm-wide nanopillars are made of silicon oxide structured by deep reactive ion etching. In future work, beyond their cell positioning purpose, the nanopillars could be functionalized as sensors. The proof of concept of the novel microstructure for organized cell culture is given by the successful growth of interconnected PC12 cells. Promoted by the honeycomb geometry, a dense network of interconnections between the cells has formed and the intended intimate contact of cells with the nanopillar arrays was observed by scanning electron microscopy. This proves the potential of these new devices as tools for the controlled cell growth in an interconnected container system with well-defined 3D geometry. (paper)

SuDS and human behaviour: Co-developing solutions to encourage sustainable behaviour

Directory of Open Access Journals (Sweden)

Everett Glyn

2016-01-01

Full Text Available Sustainable Drainage Systems (SuDS are today widely considered to be a more progressive and environmentally sensitive approach to Flood Risk Management (FRM. However, this paper argues that the sustainability of SuDS should not be so simply presumed. Devices will depend upon correct behaviour from those local to them in order to function properly over time, and for Green Infrastructure SuDS to flourish and deliver their promised multiple benefits. This paper looks to the potential value in using Social Practice Theory as a lens for understanding current behaviours around SuDS devices, and for assessing possible strategies for encouraging positive behaviour amongst affected communities. It concludes in arguing that involving local people as much as possible in the co-design of systems and then working to maintain involvement and awareness will be the most cost-effective means by which SuDS might be made to live up to the sustainability they are celebrated for.

Dimensional Reduction of N=1, E_8 SYM over SU(3)/U(1) x U(1) x Z_3 and its four-dimensional effective action

CERN Document Server

Irges, Nikos; Zoupanos, George

2011-01-01

We present an extension of the Standard Model inspired by the E_8 x E_8 Heterotic String. In order that a reasonable effective Lagrangian is presented we neglect everything else other than the ten-dimensional N=1 supersymmetric Yang-Mills sector associated with one of the gauge factors and certain couplings necessary for anomaly cancellation. We consider a compactified space-time M_4 x B_0 / Z_3, where B_0 is the nearly-Kaehler manifold SU(3)/U(1) x U(1) and Z_3 is a freely acting discrete group on B_0. Then we reduce dimensionally the E_8 on this manifold and we employ the Wilson flux mechanism leading in four dimensions to an SU(3)^3 gauge theory with the spectrum of a N=1 supersymmetric theory. We compute the effective four-dimensional Lagrangian and demonstrate that an extension of the Standard Model is obtained with interesting features including a conserved baryon number and fixed tree level Yukawa couplings and scalar potential. The spectrum contains new states such as right handed neutrinos and heavy ...

SU(4)

Indian Academy of Sciences (India)

Abstract. We introduce in this paper embedded Gaussian unitary ensemble of random matrices, for m fermions in Ω number of single particle orbits, generated by random two- body interactions that are SU(4) scalar, called EGUE(2)-SU(4). Here the SU(4) algebra corresponds to Wigner's supermultiplet SU(4) symmetry in ...

Fabrication and characterization of microcavity lasers in rhodamine B doped SU8 using high energy proton beam

Science.gov (United States)

Venugopal Rao, S.; Bettiol, A. A.; Vishnubhatla, K. C.; Bhaktha, S. N. B.; Narayana Rao, D.; Watt, F.

2007-03-01

The authors present their results on the characterization of individual dye-doped microcavity polymer lasers fabricated using a high energy proton beam. The lasers were fabricated in rhodamine B doped SU8 resist with a single exposure step followed by chemical processing. The resulting trapezoidal shaped cavities had dimensions of ˜250×250μm2. Physical characterization of these structures was performed using a scanning electron microscope while the optical characterization was carried out by recording the emission subsequent to pumping the lasers with 532nm, 6 nanosecond pulses. The authors observed intense, narrow emission near 624nm with the best emission linewidth full width at half maximum of ˜9nm and a threshold ˜150μJ/mm2.

MEMS flexible artificial basilar membrane fabricated from piezoelectric aluminum nitride on an SU-8 substrate

International Nuclear Information System (INIS)

Jang, Jongmoon; Choi, Hongsoo; Jang, Jeong Hun

2017-01-01

In this paper, we present a flexible artificial basilar membrane (FABM) that mimics the passive mechanical frequency selectivity of the basilar membrane. The FABM is composed of a cantilever array made of piezoelectric aluminum nitride (AlN) on an SU-8 substrate. We analyzed the orientations of the AlN crystals using scanning electron microscopy and x-ray diffraction. The AIN crystals are oriented in the c -axis (0 0 2) plane and effective piezoelectric coefficient was measured as 3.52 pm V −1 . To characterize the frequency selectivity of the FABM, mechanical displacements were measured using a scanning laser Doppler vibrometer. When electrical and acoustic stimuli were applied, the measured resonance frequencies were in the ranges of 663.0–2369 Hz and 659.4–2375 Hz, respectively. These results demonstrate that the mechanical frequency selectivity of this piezoelectric FABM is close to the human communication frequency range (300–3000 Hz), which is a vital feature of potential auditory prostheses. (paper)

New gauged N = 8, D = 4 supergravities

International Nuclear Information System (INIS)

Hull, C M

2003-01-01

New gaugings of four-dimensional N = 8 supergravity are constructed, including one which has a Minkowski space vacuum that preserves N = 2 supersymmetry and in which the gauge group is broken to SU(3) x U(1) 2 . Previous gaugings used the form of the ungauged action which is invariant under a rigid SL (8,R) symmetry and promoted a 28-dimensional subgroup (SO(8), SO(p, 8 - p) or the non-semi-simple contraction CSO(p, q, 8 - p - q)) to a local gauge group. Here, a dual form of the ungauged action is used which is invariant under SU*(8) instead of SL (8,R) and new theories are obtained by gauging 28-dimensional subgroups of SU*(8). The gauge groups are non-semi-simple and are different real forms of the CSO(2p, 8 - 2p) groups, denoted as CSO*(2p, 8 - 2p), and the new theories have a rigid SU(2) symmetry. The five-dimensional gauged N = 8 supergravities are dimensionally reduced to D = 4. The D = 5, SO(p, 6 - p) gauge theories reduce, after a duality transformation, to the D = 4, CSO(p, 6 - p, 2) gauging while the SO*(6) gauge theory reduces to the D = 4, CSO*(6, 2) gauge theory. The new theories are related to the old ones via an analytic continuation. The non-semi-simple gaugings can be dualized to forms with different gauge groups

Terceros retenidos según su ubicación

OpenAIRE

Barreto, Milena Natalia

2017-01-01

Los terceros molares empiezan su formación alrededor de los 8 años de edadterminando su amelogénesis a los 18 o 20 años y completando su ápico-formación entre los 20 a 23 años. En la retención interósea (el diente esta rodeado por tejido óseo) o extra ósea (el diente esta rodeado por mucosa gingival) de los terceros molares, la causa principal es por la falta de espacio dentro de la boca. Los signos y síntomas que se presentan son: encías inflamadas y dolorosas disminución apertura bucal, dol...

Experience with the operation of a solar central heating system in Friedrichshafen/Wiggenhausen-Sued; Betriebserfahrungen mit der solaren Nahwaermeversorgung in Friedrichshafen/Wiggenhausen-Sued

Energy Technology Data Exchange (ETDEWEB)

Stanzel, B.; Gawantka, F. [Technische Werke Friedrichshafen GmbH, Friedrichshafen (Germany)

1998-12-31

The ideas, concepts and pilot plants for solar central heating systems developed by the Institute for Thermodynamics and Thermal Engineering of Stuttgart University were implemented by the Steinbeis-Transfer Centre for Energy, Building and Solar Engineering. In order to improve the economic efficiency of solar central heating with long-term storage a pilot plant with a heat storage tank of 12,000 cubic metres was built in Wiggenhausen-Sued. The `Technische Werke Friedrichshafen` (TWF) is in charge of the project `Solar City Wiggenhausen-Sued`. This company built the plant and also operates and maintains it. (orig.) [Deutsch] Die Ideen, Konzepte und erste Pilotanlagen zur solaren Nahwaerme werden seit Mitte der achtziger Jahre vom Institut fuer Thermodynamik und Waermetechnik (ITW) der Universitaet Stuttgart entwickelt und vom Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik umgesetzt. Um die solare Nahwaermeversorgung mit Langzeit-Waermespeicher der Wirtschaftlichkeit etwas naeher zu bringen, wurde eine Pilotanlage mit einem 12.000 m{sup 3} grossen Waermespeicher in Wiggenhausen-Sued gebaut. Mit diesem Pilotprojekt soll neben der technischen Durchfuehrbarkeit die Kostendegression durch steigende Anlagengroesse nachgewiesen werden. Als Energiedienstleistungsunternehmen hat die Technische Werke Friedrichshafen GmbH (TWF) die technische und kaufmaennische Durchfuehrung des Projektes `Solarstadt Wiggenhausen-Sued` uebernommen. Sie errichtete, betreibt und wartet die Anlage. (orig.)

The CD8+ memory T-cell state of readiness is actively maintained and reversible

Science.gov (United States)

Allam, Atef; Conze, Dietrich B.; Giardino Torchia, Maria Letizia; Munitic, Ivana; Yagita, Hideo; Sowell, Ryan T.; Marzo, Amanda L.

2009-01-01

The ability of the adaptive immune system to respond rapidly and robustly upon repeated antigen exposure is known as immunologic memory, and it is thought that acquisition of memory T-cell function is an irreversible differentiation event. In this study, we report that many phenotypic and functional characteristics of antigen-specific CD8 memory T cells are lost when they are deprived of contact with dendritic cells. Under these circumstances, memory T cells reverted from G1 to the G0 cell-cycle state and responded to stimulation like naive T cells, as assessed by proliferation, dependence upon costimulation, and interferon-γ production, without losing cell surface markers associated with memory. The memory state was maintained by signaling via members of the tumor necrosis factor receptor superfamily, CD27 and 4-1BB. Foxo1, a transcription factor involved in T-cell quiescence, was reduced in memory cells, and stimulation of naive CD8 cells via CD27 caused Foxo1 to be phosphorylated and emigrate from the nucleus in a phosphatidylinositol-3 kinase–dependent manner. Consistent with these results, maintenance of G1 in vivo was compromised in antigen-specific memory T cells in vesicular stomatitis virus-infected CD27-deficient mice. Therefore, sustaining the functional phenotype of T memory cells requires active signaling and maintenance. PMID:19617575

Unconstrained SU(2) and SU(3) Yang-Mills classical mechanics

International Nuclear Information System (INIS)

Dahmen, B.; Raabe, B.

1992-01-01

A systematic study of contraints in SU(2) and SU(3) Yang-Mills classical mechanics is performed. Expect for the SU(2) case with spatial angular momenta they turn out to be nonholonomic. The complete elimination of the unphysical gauge and rotatinal degrees of freedom is achieved using Dirac's constraint formalism. We present an effective unconstrained formulation of the general SU(2) Yang-Mills classical mechanics as well as for SU(3) in the subspace of vanishing spatial angular momenta that is well suited for further explicit dynamical investigations. (orig.)

Unconstrained SU(2) and SU(3) Yang-Mills clasical mechanics

International Nuclear Information System (INIS)

Dahmen, B.; Raabe, B.

1992-01-01

A systematic study of constraints in SU(2) and SU(3) Yang-Mills classical mechanics is performed. Expect for the SU(2) case with vanishing spatial angular momenta they turn out to be non-holonomic. Using Dirac's constraint formalism we achieve a complete elimination of the unphysical gauge and rotational degrees of freedom. This leads to an effective unconstrained formulation both for the full SU(2) Yang-Mills classical mechanics and for the SU(3) case in the subspace of vanishing spatial angular momenta. We believe that our results are well suited for further explicit dynamical investigations. (orig.)

A novel and simple fabrication method of embedded SU-8 micro channels by direct UV lithography

International Nuclear Information System (INIS)

Fu, C; Hung, C; Huang, H

2006-01-01

In this paper, we presents a novel and simple method to fabricate embedded micro channels. The method based on different light absorption properties of the SU-8 thick photoresist under different incident UV wavelengths. The channel structures are defined by the ordinary I-line, while the cover layer is patterned by the deep UV. Because the deep UV is obtained directly on the same aligner with a set of filter mirrors, the embedded channel can be easily produced without other rare facilities. Besides, the relationship between the thickness of the top layer and the exposure dose of the deep UV has been measured by an ingeniously designed experiment. The specific thickness of the top layer of the embedded micro channel can then be secured by the specific deep-UV exposure dose. Further more, many meaningful mechanical structures have been realized by this method, the material property of the top layer are also measured

Design and fabrication of an ac-electro-osmosis micropump with 3D high-aspect-ratio electrodes using only SU-8

International Nuclear Information System (INIS)

Rouabah, Hamza A; Morgan, Hywel; Green, Nicolas G; Park, Benjamin Y; Zaouk, Rabih B; Madou, Marc J

2011-01-01

Lab-on-a-chip devices require integrated pumping and fluid control in microchannels. A recently developed mechanism that can produce fluid flow is an integrated ac-electro-osmosis micropump. However, like most electrokinetic pumps, ac-electro-osmotic pumps are incapable of handling backpressure as the pumping force mechanism acts on the surface of the fluid rather than the bulk. This paper presents a novel 3D electrode structure designed to overcome this limitation. The electrodes are fabricated using carbon-MEMS technology based on the pyrolysis of the photo-patternable polymer SU-8. The novel ac-electro-osmosis micropump shows an increase in the flow velocity compared to planar electrodes.

String derived exophobic SU(6)×SU(2) GUTs

International Nuclear Information System (INIS)

Bernard, Laura; Faraggi, Alon E.; Glasser, Ivan; Rizos, John; Sonmez, Hasan

2013-01-01

With the apparent discovery of the Higgs boson, the Standard Model has been confirmed as the theory accounting for all sub-atomic phenomena. This observation lends further credence to the perturbative unification in Grand Unified Theories (GUTs) and string theories. The free fermionic formalism yielded fertile ground for the construction of quasi-realistic heterotic-string models, which correspond to toroidal Z 2 ×Z 2 orbifold compactifications. In this paper we study a new class of heterotic-string models in which the GUT group is SU(6)×SU(2) at the string level. We use our recently developed fishing algorithm to extract an example of a three generation SU(6)×SU(2) GUT model. We explore the phenomenology of the model and show that it contains the required symmetry breaking Higgs representations. We show that the model admits flat directions that produce a Yukawa coupling for a single family. The novel feature of the SU(6)×SU(2) string GUT models is that they produce an additional family universal anomaly free U(1) symmetry, and may remain unbroken below the string scale. The massless spectrum of the model is free of exotic states.

Renormalization effects in the SU(16) maximally gauged theory

International Nuclear Information System (INIS)

Mahdavi-Hezaveh, E.

1981-03-01

In the context of a quark-lepton unified gauge theory, when fermionic degrees of freedom are maximally gauged, several intermediate mass scales filling the grand plateau, between 10 2 Gev. and the grand unifying mass scale, M, may exist. In particular, when renormalization effects are taken into account for the SU(16) ''maximal'' gauge symmetry, [in which lepton number is regarded as the fourth color quantum number], it turns out that two intermediate stages governed by the symmetries G 2 =SU(8)sub(I) S SU(8)sub(II) X U(1)sub(F) and G 3 =SU(2)sub(L) X XU(2)sub(R) X SU(4)sub(C) can naturally coexist if Sin 2 theta (Msub(W))>1/6+5/9(α(Msub(W)/αsub(S)(Msub(W)). It is shown that these symmetries break down at a mass scale of the order of Msub(X) approximately equal to 10 4 -10 5 Gev. If neutral current phenomenology (or any other experiment) predicts Sin 2 theta (Msub(W))>0.206, then quark-lepton unification and left-right symmetry simultaneously break down at M approximately equal to 10 4 Gev. (at which αsub(C)(Msub(X) approximately equal to 0.041). It is then argued that apart from proton decay, n-anti n oscillation and neutrinoless double β decay processes, an accurate experimental value of Sin 2 theta (Msub(W)), to α 10 -4 accuracy) plays a crucial role in determining the possible existence of such intermediate stages. (author)

Nucleon spin-flavor structure in the SU(3)-breaking chiral quark model

International Nuclear Information System (INIS)

Song, X.; McCarthy, J.S.; Weber, H.J.

1997-01-01

The SU(3) symmetric chiral quark model, which describes interactions between quarks, gluons, and the Goldstone bosons, explains reasonably well many aspects of the flavor and spin structure of the proton, except for the values of f 3 /f 8 and Δ 3 /Δ 8 . Introducing the SU(3)-breaking effect suggested by the mass difference between the strange and nonstrange quarks, we find that this discrepancy can be removed and better overall agreement obtained. copyright 1997 The American Physical Society

Coherent states related with SU(N) and SU(N,1) groups

International Nuclear Information System (INIS)

Gitman, D.M.; Shelepin, A.L.

1990-01-01

The basis of coherent state (CS) for symmetric presentations of groups SU(N) and SU(N,1) is plotted, its properties being investigated. Evolution of CS is considered. Relation between CS of groups SU(N) and Glauber is ascertained

Infiltration SuDS Map

OpenAIRE

Dearden, Rachel

2012-01-01

Infiltration SuDS are sustainable drainage systems (SuDS) that allow surface water to infiltrate to the ground. Examples include soakaways, infiltration basins, infiltration trenches and permeable pavements. Before planning to install Infiltration SuDS, the suitability of the ground should be assessed. The British Geological Survey has developed a bespoke Infiltration SuDS Map that enables a preliminary assessment of the suitability of the ground for infiltration SuDS. Th...

Broken SU(5) x SU(5) chiral symmetry and the classification of B mesons

International Nuclear Information System (INIS)

Hatzis, M.

1984-01-01

We consider broken SU(5) x SU(5) chiral summetry and we assume that the vacuum is SU(5)-symmetric. Using the observed mass spectrum of pseudoscalar mesons, and setting the bu mass in the range 5.2 +- 0.06 GeV, we predict the masses of bs, bc, and etasub(b) states as well as axial current couplings fsub(i)/fsub(π). SU(5) x SU(5) is found to be consistent with SU(4) x SU(4) breaking. The problem of eta - eta' - eta sub(c) - eta sub(b) mixing is also discussed

Characterization of channel waveguides and tunable microlasers in SU8 doped with rhodamine B fabricated using proton beam writing

International Nuclear Information System (INIS)

Rao, S Venugopal; Bettiol, A A; Watt, F

2008-01-01

We present our results on the fabrication and characterization of buried channel waveguides and tunable microlasers in SU8 doped with rhodamine B achieved using direct writing with a 2.0 MeV proton beam. The channel waveguides, fabricated in single exposure, had an optical propagation loss of -1 at 532 nm measured using the scattering technique while the microlasers with dimensions of 250 x 250 μm 2 had a threshold of ∼150 μJ mm -2 when pumped with 532 nm nanosecond pulses. The emitted wavelength from the microlasers was tunable to an extent of ∼15 nm with increasing pump intensity and different pumping angles. The advantages of such micro-photonic components for the realization of a lab-on-a-chip device are discussed briefly. (fast track communication)

Multiple Evolutionary Events Involved in Maintaining Homologs of Resistance to Powdery Mildew 8 in Brassica napus.

Science.gov (United States)

Li, Qin; Li, Jing; Sun, Jin-Long; Ma, Xian-Feng; Wang, Ting-Ting; Berkey, Robert; Yang, Hui; Niu, Ying-Ze; Fan, Jing; Li, Yan; Xiao, Shunyuan; Wang, Wen-Ming

2016-01-01

The Resistance to Powdery Mildew 8 (RPW8) locus confers broad-spectrum resistance to powdery mildew in Arabidopsis thaliana. There are four Homologous to RPW8s (BrHRs) in Brassica rapa and three in Brassica oleracea (BoHRs). Brassica napus (Bn) is derived from diploidization of a hybrid between B. rapa and B. oleracea, thus should have seven homologs of RPW8 (BnHRs). It is unclear whether these genes are still maintained or lost in B. napus after diploidization and how they might have been evolved. Here, we reported the identification and sequence polymorphisms of BnHRs from a set of B. napus accessions. Our data indicated that while the BoHR copy from B. oleracea is highly conserved, the BrHR copy from B. rapa is relatively variable in the B. napus genome owing to multiple evolutionary events, such as gene loss, point mutation, insertion, deletion, and intragenic recombination. Given the overall high sequence homology of BnHR genes, it is not surprising that both intragenic recombination between two orthologs and two paralogs were detected in B. napus, which may explain the loss of BoHR genes in some B. napus accessions. When ectopically expressed in Arabidopsis, a C-terminally truncated version of BnHRa and BnHRb, as well as the full length BnHRd fused with YFP at their C-termini could trigger cell death in the absence of pathogens and enhanced resistance to powdery mildew disease. Moreover, subcellular localization analysis showed that both BnHRa-YFP and BnHRb-YFP were mainly localized to the extra-haustorial membrane encasing the haustorium of powdery mildew. Taken together, our data suggest that the duplicated BnHR genes might have been subjected to differential selection and at least some may play a role in defense and could serve as resistance resource in engineering disease-resistant plants.

The SU(4), SU(2)xSU(2) chain

International Nuclear Information System (INIS)

Partensky, A.; Maguin, C.

1976-11-01

The main results of a work concerning the calculation of the matrices of the generators of SU(4) in a given (p,p',p'') irreducible representation, in which the states are labelled by the spin quantum numbers, S, MS, are given. Then the SU(4) algebra is defined, the labelling problem of the states is discussed and the Racah formula transformed, which facilitates the calculation. The semi-reduced matrix elements of the Q, Vsup(Q) and Wsup(Q) vectors are defined. Finally an explicit formulation of the matrix elements of Q is given, in the particular case T=p for any S, or S=p for any T; the example of the (3 2 0) irreducible representation is treated

SU(N) Irreducible Schwinger Bosons

OpenAIRE

Mathur, Manu; Raychowdhury, Indrakshi; Anishetty, Ramesh

2010-01-01

We construct SU(N) irreducible Schwinger bosons satisfying certain U(N-1) constraints which implement the symmetries of SU(N) Young tableaues. As a result all SU(N) irreducible representations are simple monomials of $(N-1)$ types of SU(N) irreducible Schwinger bosons. Further, we show that these representations are free of multiplicity problems. Thus all SU(N) representations are made as simple as SU(2).

Elevated soluble urokinase plasminogen activator receptor (suPAR) predicts mortality in Staphylococcus aureus bacteremia

DEFF Research Database (Denmark)

Mölkänen, T; Ruotsalainen, E; Thorball, C W

2011-01-01

The soluble form of urokinase-type plasminogen activator receptor (suPAR) is a new inflammatory marker. High suPAR levels have been shown to associate with mortality in cancer and in chronic infections like HIV and tuberculosis, but reports on the role of suPAR in acute bacteremic infections...... are scarce. To elucidate the role of suPAR in a common bacteremic infection, the serum suPAR levels in 59 patients with Staphylococcus aureus bacteremia (SAB) were measured using the suPARnostic ELISA assay and associations to 1-month mortality and with deep infection focus were analyzed. On day three, after...... the first positive blood culture for S. aureus, suPAR levels were higher in 19 fatalities (median 12.3; range 5.7-64.6 ng/mL) than in 40 survivors (median 8.4; range 3.7-17.6 ng/mL, p = 0.002). This difference persisted for 10 days. The presence of deep infection focus was not associated with elevated su...

An SU-8-based microprobe with a nanostructured surface enhances neuronal cell attachment and growth

Science.gov (United States)

Kim, Eunhee; Kim, Jin-Young; Choi, Hongsoo

2017-12-01

Microprobes are used to repair neuronal injury by recording electrical signals from neuronal cells around the surface of the device. Following implantation into the brain, the immune response results in formation of scar tissue around the microprobe. However, neurons must be in close proximity to the microprobe to enable signal recording. A common reason for failure of microprobes is impaired signal recording due to scar tissue, which is not related to the microprobe itself. Therefore, the device-cell interface must be improved to increase the number of neurons in contact with the surface. In this study, we developed nanostructured SU-8 microprobes to support neuronal growth. Nanostructures of 200 nm diameter and depth were applied to the surface of microprobes, and the attachment and neurite outgrowth of PC12 cells on the microprobes were evaluated. Neuronal attachment and neurite outgrowth on the nanostructured microprobes were significantly greater than those on non-nanostructured microprobes. The enhanced neuronal attachment and neurite outgrowth on the nanostructured microprobes occurred in the absence of an adhesive coating, such as poly- l-lysine, and so may be useful for implantable devices for long-term use. Therefore, nanostructured microprobes can be implanted without adhesive coating, which can cause problems in vivo over the long term.

Duality between SU(N)k and SU(k)N WZW models

International Nuclear Information System (INIS)

Naculich, S.G.; Schnitzer, H.J.

1990-01-01

We exhibit a duality of the SU(N) k WZW model under interchange of the group parameter N and the level k. The primary fields of SU(N) k and SU(k) N are related by transposition of their associated Young tableaux. The holomorphic blocks of the four-point functions of the primary fields are in one-to-one correspondence, and satisfy orthogonality and completeness relations with respect to one another. We derive these relations through a path integral realization of the SU(N) k WZW model in terms of a theory of constrained Dirac fermions. (orig.)

On Euclidean connections for su(1,1), suq(1,1) and the algebraic approach to scattering

International Nuclear Information System (INIS)

Ionescu, R.A.

1994-11-01

We obtain a general Euclidean connection for su(1,1) and suq(1,1) algebras. Our Euclidean connection allows an algebraic derivation for the S matrix. These algebraic S matrices reduce to the known ones in suitable circumstances. Also, we obtain a map between su(1,1) and su q (1,1) representations. (author). 8 refs

New narrow boson resonances and SU(4) symmetry: Selection rules, SU(4) mixing, and mass formulas

International Nuclear Information System (INIS)

Takasugi, E.; Oneda, S.

1975-01-01

General SU(4) sum rules are obtained for bosons in the theoretical framework of asymptotic SU(4), chiral SU(4) direct-product SU(4) charge algebra, and a simple mechanism of SU(4) and chiral SU(4) direct-product SU(4) breaking. The sum rules exhibit a remarkable interplay of the masses, SU(4) mixing angles, and axial-vector matrix elements of 16-plet boson multiplets. Under a particular circumstance (i.e., in the ''ideal'' limit) this interplay produces selection rules which may explain the remarkable stability of the newly found narrow boson resonances. General SU(4) mass formulas and inter-SU(4) -multiplet mass relations are derived and SU(4) mixing parameters are completely determined. Ground state 1 -- and 0 -+ 16-plets are especially discussed and the masses of charmed and uncharmed new members of these multiplets are predicted

Path integrals and coherent states of SU(2) and SU(1,1)

CERN Document Server

Inomata, Akira; Kuratsuji, Hiroshi

1992-01-01

The authors examine several topical subjects, commencing with a general introduction to path integrals in quantum mechanics and the group theoretical backgrounds for path integrals. Applications of harmonic analysis, polar coordinate formulation, various techniques and path integrals on SU(2) and SU(1, 1) are discussed. Soluble examples presented include particle-flux system, a pulsed oscillator, magnetic monopole, the Coulomb problem in curved space and others.The second part deals with the SU(2) coherent states and their applications. Construction and generalization of the SU(2) coherent sta

suPAR

DEFF Research Database (Denmark)

Hodges, Gethin W; Bang, Casper N; Wachtell, Kristian

2015-01-01

The fundamental role of inflammation in cardiovascular disease (CVD) has prompted interest in numerous biomarkers that detect subclinical levels of inflammation. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker that correlates significantly with cardiovascular events ...... comprehensive review of suPAR in CVD and explore its function and usefulness in predicting cardiovascular events....

Multiple evolutionary events involved in maintaining homologs of Resistance to Powdery Mildew 8 in Brassica napus

Directory of Open Access Journals (Sweden)

Qin Li

2016-07-01

Full Text Available The Resistance to Powdery Mildew 8 (RPW8 locus confers broad-spectrum resistance to powdery mildew in Arabidopsis thaliana. There are four Homologous to RPW8s (BrHRs in Brassica rapa and three in B. oleracea (BoHRs. B. napus (Bn is derived from diploidization of a hybrid between B. rapa and B. oleracea, thus should have seven homologs of RPW8 (BnHRs. It is unclear whether these genes are still maintained or lost in B. napus after diploidization and how they might have been evolved. Here we reported the identification and sequence polymorphisms of BnHRs from a set of B. napus accessions. Our data indicated that while the BoHR copy from B. oleracea is highly conserved, the BrHR copy from B. rapa is relatively variable in the B. napus genome owing to multiple evolutionary events, such as gene loss, point mutation, insertion, deletion and intragenic recombination. Given the overall high sequence homology of BnHR genes, it is not surprising that both intragenic recombination between two orthologs and two paralogs were detected in B. napus, which may explain the loss of BoHR genes in some B. napus accessions. When ectopically expressed in Arabidopsis, a C-terminally truncated version of BnHRa and BnHRb, as well as the full length BnHRd fused with YFP at their C-termini could trigger cell death in the absence of pathogens and enhanced resistance to powdery mildew disease. Moreover, subcellular localization analysis showed that both BnHRa-YFP and BnHRb-YFP were mainly localized to the extra-haustorial membrane (EHM encasing the haustorium of powdery mildew. Taken together, our data suggest that the duplicated BnHR genes might have been subjected to differential selection and at least some may play a role in defense and could serve as resistance resource in engineering disease-resistant plants.

Influencia de la formulación de la arena en verde en su difusividad térmica y su efecto en una pieza colada

Directory of Open Access Journals (Sweden)

Noguez, M. E.

2005-12-01

Full Text Available Data evidencing a relation among green sand formulations (% water/% bentonite, w/b, in the ranks 0.2-0.55 for 6, 7, 8 and 9 % bentonite, their heat transfer behaviour, specifically their thermal diffusivity, the casting solidification rate and the resulting macrostructures in aluminium castings are presented.

Se presentan evidencias de que la formulación de una arena en verde (relación entre los porcentajes de agua y de bentonita, a/b, en el rango 0,2-0,55 para 6, 7, 8 y 9 % de bentonita parece determinar su transferencia de calor y, por tanto, su coeficiente de difusividad térmica, lo que influye en la rapidez de solidificación y en las macroestructuras de piezas coladas en aluminio.

Photocleavable microcapsules built from photoreactive nanospheres.

Science.gov (United States)

Yuan, Xiaofeng; Fischer, Karl; Schärtl, Wolfgang

2005-09-27

We show how photo-cross-linking of nanoparticles within the micrometer-sized thin oil shell of water-oil-water emulsion droplets leads to a new species of optically addressable microcontainers. The inner water droplet of these emulsions may contain drugs, dyes, or other water-soluble components, leading to filled containers. The thickness, mechanical stability, and light resistance of the container walls can be controlled in a simple way by the amount and adjustable photoreactivity of the nanoparticles. Importantly, the chemical bonds between the nanoparticles constituting the microcapsule shell can be cleaved photochemically by irradiation with UV light. This optically controlled destruction of our microcontainers opens up a pathway to controlled release of the enclosed components, as will be illustrated by the example of enclosed cyclodextrin molecules.

Analiza kvalitete procesa sušenja u klasičnim komornim sušionicama

OpenAIRE

Sedlar, Tomislav; Pervan, Stjepan

2010-01-01

U radu su dani rezultati ispitivanja kvalitete sušenja u klasičnoj komornoj sušionici. Ispitivanje se temelji na novoj metodologiji kojom se prikazuje razina uspješnosti procesa sušenja na temelju analize kvalitete tog procesa u klasičnoj komornoj sušionici, korištenjem znanstveno unaprijeđene verzije liste provjere u svakodnevnoj praktičnoj primjeni. Za verificiranje nove metodologije ispitivanja izabrano je poduzeće koje se specijaliziralo za izradu lamel parketa i klasičnog parketa. U s...

Viral Escape Mutant Epitope Maintains TCR Affinity for Antigen yet Curtails CD8 T Cell Responses.

Directory of Open Access Journals (Sweden)

Shayla K Shorter

Full Text Available T cells have the remarkable ability to recognize antigen with great specificity and in turn mount an appropriate and robust immune response. Critical to this process is the initial T cell antigen recognition and subsequent signal transduction events. This antigen recognition can be modulated at the site of TCR interaction with peptide:major histocompatibility (pMHC or peptide interaction with the MHC molecule. Both events could have a range of effects on T cell fate. Though responses to antigens that bind sub-optimally to TCR, known as altered peptide ligands (APL, have been studied extensively, the impact of disrupting antigen binding to MHC has been highlighted to a lesser extent and is usually considered to result in complete loss of epitope recognition. Here we present a model of viral evasion from CD8 T cell immuno-surveillance by a lymphocytic choriomeningitis virus (LCMV escape mutant with an epitope for which TCR affinity for pMHC remains high but where the antigenic peptide binds sub optimally to MHC. Despite high TCR affinity for variant epitope, levels of interferon regulatory factor-4 (IRF4 are not sustained in response to the variant indicating differences in perceived TCR signal strength. The CD8+ T cell response to the variant epitope is characterized by early proliferation and up-regulation of activation markers. Interestingly, this response is not maintained and is characterized by a lack in IL-2 and IFNγ production, increased apoptosis and an abrogated glycolytic response. We show that disrupting the stability of peptide in MHC can effectively disrupt TCR signal strength despite unchanged affinity for TCR and can significantly impact the CD8+ T cell response to a viral escape mutant.

desde su cultura

Directory of Open Access Journals (Sweden)

Luz Ángela Argote O.

2008-01-01

Full Text Available Para explorar las prácticas sobre protección y cuidado durante la transición del climaterio a la menopausia se llevó a cabo un estudio en mujeres colombianas afrodescendientes que viven en el Distrito de Aguablanca, Cali, Colombia, a fin de evaluar los factores socioculturales que influyen en su cuidado. Se siguió la etnoenfermería con el objeto de averiguar la perspectiva femenina étnica, e identificar las prácticas beneficiosas y de riesgo para su salud. La investigación tuvo como participantes claves a 17 mujeres. En la consolidación de la muestra se aplicaron los criterios de saturación de datos. En los resultados se evidenció la relación de las mujeres con su propio cuerpo, su defensa y fortificación desde la menarquia como fase preparatoria de sus funciones reproductivas, hasta cuando aparece la menopausia. De acuerdo con su cultura, si no tienen en cuenta estas prácticas tradicionales, sufrirán diversas dolencias en la etapa final de su periodo de procreación. Los cuidados sobresalientes se relacionan con el significado de la sangre, así como con el ejercicio de la sexualidad, la limpieza, la alimentación especial y el equilibrio que se debe guardar entre el calor y el frío. Las entrevistadas atribuyen a la menopausia cambios en su cuerpo, en sus diferencias emocionales de conducta y en las expectativas de la sexualidad. Para el presente estudio estos hallazgos se agruparon en tres temas principales: sentir los profundos cambios en la vida: el cuerpo; sentir los cambios en los estados de ánimo; y vivir la sexualidad.

Ispitivanje pogodnosti za održavanje elektronskih uređaja / Demonstration and verification of the maintainability of electronic devices

Directory of Open Access Journals (Sweden)

Dragan Ćosović

2003-11-01

Full Text Available Ispitivanje pogodnosti za održavanje, u toku razvoja uređaja, sastavni je deo Programa i plana pogodnosti za održavanje. U toku ispitivanja proveravaju se kvantitativni i kvalitativni parametri pogodnosti za održavanje. Ispitivanje kvantitativnih parametara vrši se primenom određenih statističkih metoda. U radu je dat primer primene statističkih metoda za ispitivanje pogodnosti za korektivno održavanje jednog elektronskog uređaja i analizirani su rezultati ispitivanja. / The demonstration and verification of maintainability during the development of a device is an integral part of the Maintainability Plan and Programme. During the demonstration and verification, the quantitative and qualitative parameters of maintainability are checked. The demonstration and verification of the maintainability parameters are done by applying certain statistical methods. An example of applying a statistical methods for testing the maintainability of corrective maintenance of radio is given in the work and the results of the demonstration and verification are analyzed.

Dark revelations of the [SU(3)]3 and [SU(3)]4 gauge extensions of the standard model

Science.gov (United States)

Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

2018-02-01

Two theoretically well-motivated gauge extensions of the standard model are SU(3)C × SU(3)L × SU(3)R and SU(3)q × SU(3)L × SU(3)l × SU(3)R, where SU(3)q is the same as SU(3)C and SU(3)l is its color leptonic counterpart. Each has three variations, according to how SU(3)R is broken. It is shown here for the first time that a built-in dark U(1)D gauge symmetry exists in all six versions. However, the corresponding symmetry breaking pattern does not reduce properly to that of the standard model, unless an additional Z2‧ symmetry is defined, so that U(1)D ×Z2‧ is broken to Z2 dark parity. The available dark matter candidates in each case include fermions, scalars, as well as vector gauge bosons. This work points to the possible unity of matter with dark matter, the origin of which may not be ad hoc.

Dark revelations of the [SU(3]3 and [SU(3]4 gauge extensions of the standard model

Directory of Open Access Journals (Sweden)

Corey Kownacki

2018-02-01

Full Text Available Two theoretically well-motivated gauge extensions of the standard model are SU(3C×SU(3L×SU(3R and SU(3q×SU(3L×SU(3l×SU(3R, where SU(3q is the same as SU(3C and SU(3l is its color leptonic counterpart. Each has three variations, according to how SU(3R is broken. It is shown here for the first time that a built-in dark U(1D gauge symmetry exists in all six versions. However, the corresponding symmetry breaking pattern does not reduce properly to that of the standard model, unless an additional Z2′ symmetry is defined, so that U(1D×Z2′ is broken to Z2 dark parity. The available dark matter candidates in each case include fermions, scalars, as well as vector gauge bosons. This work points to the possible unity of matter with dark matter, the origin of which may not be ad hoc.

Minimal Supersymmetric $SU(4) \\to SU(2)_L \\to SU(2)_R$

CERN Document Server

King, S F

1998-01-01

We present a minimal string-inspired supersymmetric $SU(4) \\times SU(2)_L potential in this model, based on a generalisation of that recently proposed by Dvali, Lazarides and Shafi. The model contains a global U(1) R-symmetry and reduces to the MSSM at low energies. However it improves on the MSSM since it explains the magnitude of its $\\mu$ term and gives a prediction for $\\tan \\beta both `cold' and `hot' dark matter candidates. A period of hybrid inflation above the symmetry breaking scale is also possible in this model. Finally it suggests the existence of `heavy' charge $\\pm e/6$ (colored) and $\\pm e/2$ (color singlet) states.

SuPAR predicts postoperative complications and mortality in patients with asymptomatic aortic stenosis

DEFF Research Database (Denmark)

Hodges, Gethin W; Bang, Casper N; Eugen-Olsen, Jesper

2018-01-01

complications with a HR of 2.7 (95% CI 1.5 to 5.1, P=0.002), per doubling in suPAR. After adjusting for the European System for Cardiac Operative Risk Evaluation or Society of Thoracic Surgeons risk score, suPAR remained associated with postoperative mortality with a HR 3.2 (95% CI 1.2 to 8.6, P=0.025) and 2...

Determination of maintainability for Dacia 1304, 1,9 D utility vehicle

Science.gov (United States)

Budiul Berghian, A.; Vasiu, T.; Birtok Baneasa, C.

2018-01-01

The study analyses the ability to be maintained or rehabilitation of Dacia 1304, 1,9D utility vehicle. The paper comprises the determination of its maintainability using the Weibull++8 specialized software.

The influence of hard-baking temperature applied for SU8 sensor layer on the sensitivity of capacitive chemical sensor

Science.gov (United States)

Klanjšek Gunde, Marta; Hauptman, Nina; Maček, Marijan; Kunaver, Matjaž

2009-06-01

SU8, the near-UV photosensitive epoxy-based polymer was used as a sensor layer in the capacitive chemical sensor, ready for integration with a generic double-metal CMOS technology. It was observed that the response of the sensor slowly increases with the temperature applied in hard-baking process as long as it remains below 300°C. At this temperature the response of the sensor abruptly increases and becomes almost threefold. It was shown that fully crosslinked structure of the sensor layer becomes opened and disordered when the sensor is hard-baked at temperatures between 300°C and 320°C, that is, still well below the degradation temperature of the polymer. These changes in chemical structure were analyzed by Fourier-transform infrared spectroscopy. The temperature-dependent changes of the sensor layer structure enable one to prepare a combination of capacitive chemical sensors with good discrimination between some volatile organic compounds.

SU(6), baryonic decays of B-mesons and CP

International Nuclear Information System (INIS)

Wu, D.

1990-01-01

In this paper the four fermion weak decay Hamiltonian is expressed in terms of quark-antiquark creation operators with specific spin orientations. Then the SU(6) symmetry of the strong interactions among light quarks is imposed to find 8 invariant decay amplitudes for two body charmful baryonic decays of the B-mesons, 3 S-waves, 4 P- waves and 1 D-wave. Λ c branching ratio and some exclusive branching ratios are calculated based on the assumption of two body dominance in baryonic decay modes. Results on two body mesonic decays are also given. Relation between the SU(6) scheme and the quark diagram scheme is discussed

Duality relations between SU(N)k and SU(k)NWZW models and their braid matrices

International Nuclear Information System (INIS)

Naculich, S.G.; Schnitzer, H.J.

1990-01-01

Dual relations are found between the primary fields, correlators, and conformal blocks of SU(N) k and SU(k) N WZW models, which in turn imply dual relations between the braid matrices of the two theories. These results are a consequence of the fact that the spaces of conformal blocks of SU(N) k and SU(k) N correlation functions are dual. (orig.)

Optical Amplification at 1525 nm in BaYF5: 20% Yb3+, 2% Er3+ Nanocrystals Doped SU-8 Polymer Waveguide

Directory of Open Access Journals (Sweden)

Pengcheng Zhao

2014-01-01

Full Text Available We demonstrated optical amplification in BaYF5: 20% Yb3+, 2% Er3+ (BYF nanocrystals doped polymer waveguide. BYF nanocrystals with an average size of ∼13 nm were synthesized by a high-boiling solvent process. Intense 1.53 μm fluorescence was obtained in the nanocrystals under excitation at 980 nm. An optical polymer waveguide was fabricated by using BYF nanocrystals doped SU-8 polymer as the core material. A relative optical gain of ∼10.4 dB at 1525 nm was achieved in a 1.1 cm long waveguide for an input signal power of ∼0.09 mW and a pump power of ∼212 mW.

Los Grammy Latino, su meta inicial y su fin comercial

Directory of Open Access Journals (Sweden)

Marinés Arroyo Sotomayor

2015-01-01

Full Text Available El artículo refiere lo que es este festival musical que premia el talento latino, quienes participan, su meta inicial y su fin comercial. Muestra que a pesar de la tradición de intolerancia del exilio cubano, la música sirvió, una vez más, como puente de cultura

Classification of three-family grand unification in string theory. II. The SU(5) and SU(6) models

International Nuclear Information System (INIS)

Kakushadze, Z.; Tye, S.H.

1997-01-01

Requiring that supersymmetric SU(5) and SU(6) grand unifications in the heterotic string theory must have three chiral families, adjoint (or higher representation) Higgs fields in the grand unified gauge group, and a non-Abelian hidden sector, we construct such string models within the framework of free conformal field theory and asymmetric orbifolds. Within this framework, we construct all such string models via Z 6 asymmetric orbifolds that include a Z 3 outerautomorphism, the latter yielding a level-three current algebra for the grand unification gauge group SU(5) or SU(6). We then classify all such Z 6 asymmetric orbifolds that result in models with a non-Abelian hidden sector. All models classified in this paper have only one adjoint (but no other higher representation) Higgs field in the grand unified gauge group. This Higgs field is neutral under all other gauge symmetries. The list of hidden sectors for three-family SU(6) string models are SU(2), SU(3), and SU(2)circle-times SU(2). In addition to these, three-family SU(5) string models can also have an SU(4) hidden sector. Some of the models have an apparent anomalous U(1) gauge symmetry. copyright 1997 The American Physical Society

SU(2) and SU(1,1) squeezing of interacting radiation modes

International Nuclear Information System (INIS)

Abdalla Sebawe, M.; Faisal El-Orany, A.A.; Perina, J.

2000-01-01

In this communication we discuss SU(1,1) and SU(2) squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated. (authors)

Baryon spectroscopy and SU(6)

International Nuclear Information System (INIS)

Litchfield, P.

1977-09-01

An elementary account of the SU(6) formalism for baryons is given. The assignment of the known resonances to SU(6) multiplets is discussed and an experimental scheme given for the spectrum of SU(6) x 0(2) multiplets. (author)

Inflation and monopoles in supersymmetric SU(4)c x SU(2)L x SU(2)R

International Nuclear Information System (INIS)

Jeannerot, R.; Khalil, S.; Lazarides, G.; Shafi, Q.

2000-02-01

We show how hybrid inflation can be successfully realized in a supersymmetric model with gauge group G PS = SU(4) c x SU(2) L x SU(2) R . By including a non-renormalizable superpotential term, we generate an inflationary valley along which G PS is broken to the standard model gauge group. Thus, catastrophic production of the doubly charged magnetic monopoles, which are predicted by the model, cannot occur at the end of inflation. The results of the cosmic background explorer can be reproduced with natural values (of order 10 -3 ) of the relevant coupling constant, and symmetry breaking scale of G PS close to 10 16 GeV. The spectral index of density perturbations lies between unity and 0.94. Moreover, the μ-term is generated via a Peccei-Quinn symmetry and proton is practically stable. Baryogenesis in the universe takes place via leptogenesis. The low deuterium abundance constraint on the baryon asymmetry, the gravitino limit on the reheat temperature and the requirement of almost maximal ν μ - ν τ mixing from SuperKamiokande can be simultaneously met with m νμ , m ντ and heaviest Dirac neutrino mass determined from the large angle MSW resolution of the solar neutrino problem, the SuperKamiokande results and SU(4) c symmetry respectively. (author)

Tabaquismo en enfermeras de Atención Primaria: Factores que influyen en su inicio y mantenimiento Smoking habits among Primary Health Care Nurses: Factors that influence taking up and maintaining it

Directory of Open Access Journals (Sweden)

Jordi Pericàs Beltrán

2009-03-01

Full Text Available Las enfermeras de Atención Primaria (AP son profesionales adecuados en la lucha contra el tabaquismo. No obstante, algunas de ellas fuman y esto puede disminuir su credibilidad y su sentimiento de autoeficacia frente al problema. El objetivo de este estudio es evidenciar los factores que pueden influir en el inicio y el mantenimiento del hábito tabáquico. Para ello, se ha realizado un estudio cualitativo desde una perspectiva fenomenológica social, en 15 enfermeras fumadoras de AP, recogiendo los datos mediante entrevista semiestructurada en profundidad. Los principales temas que emergieron fueron la falta de concienciación y el papel socializador del tabaco. Se tiene poca conciencia del papel de la publicidad y no se considera al estrés como un determinante del hábito en el ámbito de AP. Puede resultar decisivo el control del peso corporal.Primary Health Care Nurses (PHC are suitable professionals in the fight against the smoking habit. Nevertheless some of them smoke and this may diminish their credibility and their feeling of self-efficacy when faced with this problem. The aim of this study was to demonstrate the factors that may influence taking up and maintaining the smoking habit. Thus, we carried out a qualitative study from a social phenomenological perspective, in 15 PHC nurses who are smokers, collecting the data by means of a semi-structured in-depth interview. The main issues that emerged were lack of awareness and the socializing role of tobacco. There is little awareness of the role of publicity and stress is not considered to be a determining factor of the habit in the area of PHC. The control of body weight may be decisive.

On the SU(2)× SU(2) symmetry in the Hubbard model

Science.gov (United States)

Jakubczyk, Dorota; Jakubczyk, Paweł

2012-08-01

We discuss the one-dimensional Hubbard model, on finite sites spin chain, in context of the action of the direct product of two unitary groups SU(2)× SU(2). The symmetry revealed by this group is applicable in the procedure of exact diagonalization of the Hubbard Hamiltonian. This result combined with the translational symmetry, given as the basis of wavelets of the appropriate Fourier transforms, provides, besides the energy, additional conserved quantities, which are presented in the case of a half-filled, four sites spin chain. Since we are dealing with four elementary excitations, two quasiparticles called "spinons", which carry spin, and two other called "holon" and "antyholon", which carry charge, the usual spin- SU(2) algebra for spinons and the so called pseudospin-SU(2) algebra for holons and antiholons, provide four additional quantum numbers.

Developing maintainability for fusion power systems. Final report

Energy Technology Data Exchange (ETDEWEB)

Zahn, H.S.; Mantz, H.C.; Curtis, C.T.; Buchheit, R.J.; Green, W.M.; Zuckerman, D.S.

1979-11-01

The overall purpose of the study is to identify design features of fusion power reactors which contribute to the achievement of high levels of maintainability. Previous phases evaluated several commercial tokamak reactor design concepts. This final phase compares the maintainability of a tandem mirror reactor (TMR) commercial conceptual design with the most maintainable tokamak concept selected from earlier work. A series of maintainability design guidelines and desirable TMR design features are defined. The effects of scheduled and unscheduled maintenance for most of the reactor subsystems are defined. The comparison of the TMR and tokamak reactor maintenance costs and availabilities show that both reactors have similar costs for scheduled maintenance at 19.4 and 20.8 million dollars annually and similar scheduled downtime availability impacts, achieving approximate availabilities of 79% at optimized maintenance intervals and cost of electricity.

Developing maintainability for fusion power systems. Final report

International Nuclear Information System (INIS)

Zahn, H.S.; Mantz, H.C.; Curtis, C.T.; Buchheit, R.J.; Green, W.M.; Zuckerman, D.S.

1979-11-01

The overall purpose of the study is to identify design features of fusion power reactors which contribute to the achievement of high levels of maintainability. Previous phases evaluated several commercial tokamak reactor design concepts. This final phase compares the maintainability of a tandem mirror reactor (TMR) commercial conceptual design with the most maintainable tokamak concept selected from earlier work. A series of maintainability design guidelines and desirable TMR design features are defined. The effects of scheduled and unscheduled maintenance for most of the reactor subsystems are defined. The comparison of the TMR and tokamak reactor maintenance costs and availabilities show that both reactors have similar costs for scheduled maintenance at 19.4 and 20.8 million dollars annually and similar scheduled downtime availability impacts, achieving approximate availabilities of 79% at optimized maintenance intervals and cost of electricity

A cryogenic optical feedthrough using polarization maintaining fibers.

Science.gov (United States)

Nelson, M J; Collins, C J; Speake, C C

2016-03-01

Polarization maintaining optical fibers can be used to transmit linearly polarized light over long distances but their use in cryogenic environments has been limited by their sensitivity to temperature changes and associated mechanical stress. We investigate experimentally how thermal stresses affect the polarization maintaining fibers and model the observations with Jones matrices. We describe the design, construction, and testing of a feedthrough and fiber termination assembly that uses polarization maintaining fiber to transmit light from a 633 nm HeNe laser at room temperature to a homodyne polarization-based interferometer in a cryogenic vacuum. We report on the efficiency of the polarization maintaining properties of the feedthrough assembly. We also report that, at cryogenic temperatures, the interferometer can achieve a sensitivity of 8 × 10(-10) rad/√Hz at 0.05 Hz using this feedthrough.

New hierarchy in GUTs based on SU(n,1)/SU(n)U(1) SUGRA

International Nuclear Information System (INIS)

Hayashi, M.J.; Murayama, Akihiro

1985-01-01

Grand unified theories (GUTs) in the framework of SU(n, 1)/SU(n) x U(1) supergravity are discussed which naturally generate a new hierarchy, Msub(P) (Planck mass): Msub(X) (GUT scale):msub(3/2) (gravitino mass):m (explicit supersymmetry breaking scale)=1:epsilon:epsilon 3 :epsilon 5 α(Msub(X)) with Msub(P) as the only input mass scale. The SUSY breaking scale m is expected to be fixed radiatively as mproportionalMsub(W), i.e., epsilonproportional10 -3 . Our method would be applicable to any GUT based on SU(n, 1)/SU(n) x U(1) supergravity. (orig.)

Dose-finding and pharmacokinetic study of cisplatin, gemcitabine, and SU5416 in patients with solid tumors

NARCIS (Netherlands)

Kuenen, Bart C.; Rosen, Lee; Smit, Egbert F.; Parson, Mandy R. N.; Levi, Marcel; Ruijter, Rita; Huisman, Holger; Kedde, Marc A.; Noordhuis, Paul; van der Vijgh, Wim J. F.; Peters, Godefridus J.; Cropp, Gillian F.; Scigalla, Paul; Hoekman, Klaus; Pinedo, Herbert M.; Giaccone, Giuseppe

2002-01-01

Purpose: To investigate the feasibility and pharmacokinetics of the combination cisplatin, gemcitabine, and SU5416. Patients and Methods: Patients received cisplatin 80 mg/m(2) on day 1, gemcitabine 1,250 mg/m(2) on days 1 and 8, repeated every 3 weeks, and SU5416 (85 and 145 mg/m(2)) intravenously

Distinguishing between SU(5) and flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Dorsner, Ilja [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Fileviez Perez, Pavel [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy) and Pontificia Universidad Catolica de Chile, Facultad de Fisica, Casilla 306, Santiago 22 (Chile)]. E-mail: fileviez@higgs.fis.puc.cl

2005-01-13

We study in detail the d=6 operators for proton decay in the two possible matter unification scenarios based on SU(5) gauge symmetry. We investigate the way to distinguish between these two scenarios. The dependence of the branching ratios for the two body decays on the fermion mixing is presented in both cases. We point out the possibility to make a clear test of flipped SU(5) through the decay channel p->{pi}{sup +}{nu}-bar , and the ratio {tau}(p->K{sup 0}e{sub {alpha}}{sup +})/{tau}(p->{pi}{sup 0}e{sub {alpha}}{sup +})

String threshold corrections and flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Antoniadis, I. (Ecole Polytechnique, Centre de Physique Theorique, 91 - Palaiseau (France) Theory Div., CERN, Geneva (Switzerland)); Ellis, J. (Theory Div., CERN, Geneva (Switzerland)); Lacaze, R. (Service de Physique Theorique, CEN-Saclay, 91 - Gif-sur-Yvette (France)); Nanopoulos, D.V. (Center for Theoretical Physics, Dept. of Physics, Texas A and M Univ., College Station, TX (United States) Astroparticle Physics Group, HARC, The Woodlands, TX (United States) Theory Div., CERN, Geneva (Switzerland))

1991-10-10

We revise previous calculations of the effective unification scale m{sub SU} at which the extrapolated low-energy gauge couplings should appear to become equal, and we show explicitly how to calculate m{sub SU} in the fermionic construction of four-dimensional strings. In the case of the flipped SU(5) GUT derived from the string, the SU(5) and U(1) couplings defined in the anti Danti R scheme become equal to g{sub SU} at m{sub SU} {approx equal} 1.76 x g{sub SU} x 10{sup 18} GeV. This scale is significantly larger than m{sub GUT}, the scale at which the low-energy SU(3) and SU(2) couplings become equal if extrapolated using the renormalization group equations of the minimal supersymmetric extension of the standard model. The existence of an intermediate SU(5) x U(1) phase could have an observable effect on the calculated value of sin{sup 2}{theta}{sub w}. (orig.).

[SU(2)]3 dark matter

Science.gov (United States)

Ma, Ernest

2018-05-01

An extra SU(2)D gauge factor is added to the well-known left-right extension of the standard model (SM) of quarks and leptons. Under SU(2)L × SU(2)R × SU(2)D, two fermion bidoublets (2 , 1 , 2) and (1 , 2 , 2) are assumed. The resulting model has an automatic dark U (1) symmetry, in the same way that the SM has automatic baryon and lepton U (1) symmetries. Phenomenological implications are discussed, as well as the possible theoretical origins of this proposal.

El medioambiente y su salud

Science.gov (United States)

Las acciones que usted toda en su diario vivir tienen un impacto en su medioambiente y su salud. La Agencia de Protección Ambiental de EE.UU. (EPA, por sus siglas en inglés) ofrece información sobre los pasos que puede tomar para protegerse a usted y prote

Standard model fermions and N=8 supergravity

Energy Technology Data Exchange (ETDEWEB)

Nicolai, Hermann [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Muehlenberg 1, Potsdam-Golm (Germany)

2016-07-01

In a scheme originally proposed by Gell-Mann, and subsequently shown to be realized at the SU(3) x U(1) stationary point of maximal gauged SO(8) supergravity, the 48 spin-1/2 fermions of the theory remaining after the removal of eight Goldstinos can be identified with the 48 quarks and leptons (including right-chiral neutrinos) of the Standard model, provided one identifies the residual SU(3) with the diagonal subgroup of the color group SU(3){sub c} and a family symmetry SU(3){sub f}. However, there remained a systematic mismatch in the electric charges by a spurion charge of ± 1/6. We here identify the ''missing'' U(1) that rectifies this mismatch, and that takes a surprisingly simple, though unexpected form, and show how it is related to the conjectured R symmetry K(E10) of M Theory.

Fabrication of a roller type PDMS stamp using SU-8 concave molds and its application for roll contact printing

International Nuclear Information System (INIS)

Park, Jongho; Kim, Beomjoon

2016-01-01

Continuous fabrication of micropatterns at low-cost is attracting attention in various applications within industrial fields. To meet such demands, we have demonstrated a roll contact printing technique, using roller type polydimethylsiloxane (PDMS) stamps with roll-to-flat and roll-to-roll stages. Roller type PDMS stamps for roll contact printing were fabricated using a custom-made metal support and SU-8 microstructures fabricated on concave substrates as a mold. The molding/casting method which we developed here provided faster and easier fabrication than conventional methods for roller type stamps. Next, roll contact printing was performed using fabricated roller type PDMS stamps with roll-to-flat and roll-to-roll stages. Patterns with minimum widths of 3 μm and 2.1 μm were continuously fabricated for each stage, respectively. In addition, the relationship between applied pressures and dimensional changes of roll contact printed patterns was investigated. Finally, we confirmed that roll contact printing and the new fabrication method for roller stamps presented in this study demonstrated the feasibility for industrial applications. (paper)

SU(2)xSU(2) coupling rule and a tensor glueball candidate

International Nuclear Information System (INIS)

Lanik, J.

1984-01-01

The data on the decay of THETA(1640) particles are considered. It is shown that the SU(2)xSU(2) mechanism for coupling of theta(1640) tensor glueball candidate to pseudoscalar Gold-stone mesons is in a remarkable agreement with existing experimental data

Flipped SU(5) from Z{sub 12-I} orbifold with Wilson line

Energy Technology Data Exchange (ETDEWEB)

Kim, Jihn E. [Department of Physics and Astronomy, and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)]. E-mail: jekim@phyp.snu.ac.kr; Kyae, Bumseok [School of Physics, Korea Institute for Advanced Study, 207-43 Cheongryangri-dong, Dongdaemun-gu, Seoul 130-722 (Korea, Republic of)]. E-mail: bkyae@kias.re.kr

2007-05-14

We construct a three family flipped SU(5) model from the heterotic string theory compactified on the Z{sub 12-I} orbifold with one Wilson line. The gauge group is SU(5)xU(1){sub X}xU(1){sup 3}x[SU(2)xSO(10)xU(1){sup 2}]{sup '}. This model does not derive any non-Abelian group except SU(5) from E{sub 8}, which is possible only for two cases in case of one shift V, one in Z{sub 12-I} and the other in Z{sub 12-II}. We present all possible Yukawa couplings. We place the third quark family in the twisted sectors and two light quark families in the untwisted sector. From the Yukawa couplings, the model provides the R-parity, the doublet-triplet splitting, and one pair of Higgs doublets. It is also shown that quark and lepton mixings are possible. So far we have not encountered a serious phenomenological problem. There exist vector-like flavor SU(5) exotics (including Q{sub em}=+/-16 color exotics and Q{sub em}=+/-12 electromagnetic exotics) and SU(5) vector-like singlet exotics with Q{sub em}=+/-12 which can be removed near the GUT scale. In this model, sin{sup 2}{theta}{sub W}{sup 0}=38 at the full unification scale.

Study of Λ parameters and crossover phenomena in SU(N) x SU(N) sigma models in two dimensions

International Nuclear Information System (INIS)

Shigemitsu, J.; Kogut, J.B.

1981-01-01

The spin system analogues of recent studies of the string tension and Λ parameters of SU(N) gauge theories in 4 dimensions are carried out for the SU(N) x SU(N) and O(N) models in 2 dimensions. The relations between the Λ parameters of both the Euclidean and Hamiltonian formulation of the lattice models and the Λ parameter of the continuum models are obtained. The one loop finite renormalization of the speed of light in the lattice Hamiltonian formulations of the O(N) and SU(N) x SU(N) models is calculated. Strong coupling calculations of the mass gaps of these spin models are done for all N and the constants of proportionality between the gap and the Λ parameter of the continuum models are obtained. These results are contrasted with similar calculations for the SU(N) gauge models in 3+1 dimensions. Identifying suitable coupling constants for discussing the N → infinity limits, the numerical results suggest that the crossover from weak to strong coupling in the lattice O(N) models becomes less abrupt as N increases while the crossover for the SU(N) x SU(N) models becomes more abrupt. The crossover in SU(N) gauge theories also becomes more abrupt with increasing N, however, at an even greater rate than in the SU(N) x SU(N) spin models

Entropy of entangled states and SU(1,1) and SU(2) symmetries

International Nuclear Information System (INIS)

Santana, A.E.; Khanna, F.C.; Revzen, M.

2002-01-01

Based on a recent definition of a measure for entanglement [Plenio and Vedral, Contemp. Phys. 39, 431 (1998)], examples of maximum entangled states are presented. The construction of such states, which have symmetry SU(1,1) and SU(2), follows the guidance of thermofield dynamics formalism

ROGERS SU PENSAMIENTO PROFESIONAL Y SU FILOSOFÍA PERSONAL

Directory of Open Access Journals (Sweden)

Gina Pezzano de Vengoechea

2001-01-01

Full Text Available Carl Rogers denominó a su enfoque psicológico «Psicoterapia centrada en el cliente» y se asocia a la Psicología Humanista, que dignifica y valora el esfuerzo de la persona por desarrollar sus potencialidades. En esta ponencia se describen las ventajas y alcances de este enfoque, así como las limitaciones que muestra su empleo en medios socioeconómicos en desventaja. De igual manera, se analizan las enseñanzas más significativas de este psicoterapeuta acerca de las relaciones entre los individuos.

The design study of the JT-60SU device. No.8. Nuclear shielding and safety design

Energy Technology Data Exchange (ETDEWEB)

Miya, Naoyuki; Kikuchi, Mitsuru; Ushigusa, Kenkichi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

1998-03-01

Results of nuclear shielding design study and safety analysis for the steady-state tokamak device JT-60SU are described. D-T operation (option) for two years is adopted in addition to ten years operation using deuterium. Design work has been done in accordance with general laws for radioisotopes handling in Japan as a guideline of safety evaluation, which is applied to the operation of present JT-60U device. Optimization of the shielding design for the device structure including vacuum vessel has been presented to meet with allowable limits of biological shielding determined in advance. It is shown that JT-60SU can be operated safely in the present JT-60 experimental building. It is planed to use 100g/year of tritium in D-T operation phase. A concept of multiple -barrier system is applied to the facility design to prevent propagation of tritium, in which the torus hall and the tritium removal room provide the tertiary confinement. From the design of atmosphere detritiation system for accidental tritium release, it is shown that tritium concentration level can be reduced to the allowable level after two weeks with reasonable compact size components. Safety assessment related to activation of coolant/air, and atmospheric tritium effluents are discussed. (author)

JIL-1 and Su(var)3-7 Interact Genetically and Counteract Each Other's Effect on Position-Effect Variegation in Drosophila

Science.gov (United States)

Deng, Huai; Cai, Weili; Wang, Chao; Lerach, Stephanie; Delattre, Marion; Girton, Jack; Johansen, Jørgen; Johansen, Kristen M.

2010-01-01

The essential JIL-1 histone H3S10 kinase is a key regulator of chromatin structure that functions to maintain euchromatic domains while counteracting heterochromatization and gene silencing. In the absence of the JIL-1 kinase, two of the major heterochromatin markers H3K9me2 and HP1a spread in tandem to ectopic locations on the chromosome arms. Here we address the role of the third major heterochromatin component, the zinc-finger protein Su(var)3-7. We show that the lethality but not the chromosome morphology defects associated with the null JIL-1 phenotype to a large degree can be rescued by reducing the dose of the Su(var)3-7 gene and that Su(var)3-7 and JIL-1 loss-of-function mutations have an antagonistic and counterbalancing effect on position-effect variegation (PEV). Furthermore, we show that in the absence of JIL-1 kinase activity, Su(var)3-7 gets redistributed and upregulated on the chromosome arms. Reducing the dose of the Su(var)3-7 gene dramatically decreases this redistribution; however, the spreading of H3K9me2 to the chromosome arms was unaffected, strongly indicating that ectopic Su(var)3-9 activity is not a direct cause of lethality. These observations suggest a model where Su(var)3-7 functions as an effector downstream of Su(var)3-9 and H3K9 dimethylation in heterochromatic spreading and gene silencing that is normally counteracted by JIL-1 kinase activity. PMID:20457875

SUSY S4×SU(5) revisited

International Nuclear Information System (INIS)

Hagedorn, Claudia; King, Stephen F.; Luhn, Christoph

2012-01-01

Following the recent results from Daya Bay and RENO, which measure the lepton mixing angle θ 13 l ≈0.15, we revisit a supersymmetric (SUSY) S 4 ×SU(5) model, which predicts tri-bimaximal (TB) mixing in the neutrino sector with θ 13 l being too small in its original version. We show that introducing one additional S 4 singlet flavon into the model gives rise to a sizable θ 13 l via an operator which leads to the breaking of one of the two Z 2 symmetries preserved in the neutrino sector at leading order (LO). The results of the original model for fermion masses, quark mixing and the solar mixing angle are maintained to good precision. The atmospheric and solar mixing angle deviations from TB mixing are subject to simple sum rule bounds.

Balanced Hermitian metrics from SU(2)-structures

International Nuclear Information System (INIS)

Fernandez, M.; Tomassini, A.; Ugarte, L.; Villacampa, R.

2009-01-01

We study the intrinsic geometrical structure of hypersurfaces in six-manifolds carrying a balanced Hermitian SU(3)-structure, which we call balanced SU(2)-structure. We provide sufficient conditions, in terms of suitable evolution equations, which imply that a five-manifold with such structure can be isometrically embedded as a hypersurface in a balanced Hermitian SU(3)-manifold. Any five-dimensional compact nilmanifold has an invariant balanced SU(2)-structure, and we show how some of them can be evolved to give new explicit examples of balanced Hermitian SU(3)-structures. Moreover, for n=3,4, we present examples of compact solvmanifolds endowed with a balanced SU(n)-structure such that the corresponding Bismut connection has holonomy equal to SU(n)

Remarks on broken chiral SU(5) x SU(5) symmetry and B mesons

International Nuclear Information System (INIS)

Kim, D.Y.; Sinha, S.N.

1985-01-01

In a recent paper, Hatzis has estimated the masses and weak decay constants of b-flavored pseudoscalar mesons in a broken chiral SU(5) x SU(5) symmetry method. The estimated weak decay constant of B meson, f sub(B) f sub(K)(f sub(B)/f sub(K) approximately equal to 1.4) evaluated by Mathur et al. with the quantum chromodynamics (QCD) sum-rule model. We re-examined the problem applying the broken chiral SU(5) x SU(5) symmetry approach using a set of mass formulae. With this method we estimate the symmetry-breaking parameters and decay constants of pseudoscalar mesons. We found a consistent result for the decay constant: f sub(K) < or approximately equal to f sub(D) < or approximately equal to f sub(B). The explicit numerical value of these constants, however, are lower than that of the QCD sum rule. This may be due to the limited validity of the broken chiral symmetry approach for heavy mesons

SU(5) unification revisited

International Nuclear Information System (INIS)

Giveon, A.; Sarid, U.; Hall, L.J.; California Univ., Berkeley, CA

1991-01-01

Model-independent criteria for unification in the SU(5) framework are studied. These are applied to the minimal supersymmetric standard model and to the standard model with a split 45 Higgs representation. Although the former is consistent with SU(5) unification, the superpartner masses can vary over a wide range, and may even all lie well beyond the reach of planned colliders. Adding a split 45 to the standard model can also satisfy the unification criteria, so supersymmetric SU(5) is far from unique. Furthermore, we learn that separate Higgs doublets must couple to the top and bottom quarks in order to give a correct m b /m τ prediction. (orig.)

Fabrication of cell container arrays with overlaid surface topographies.

NARCIS (Netherlands)

Truckenmuller, R.; Giselbrecht, S.; Escalante-Marun, M.; Groenendijk, M.; Papenburg, B.; Rivron, N.; Unadkat, H.; Saile, V.; Subramaniam, V.; Berg, A. van den; Blitterswijk, C. Van; Wessling, M.; Boer, J. den; Stamatialis, D.

2012-01-01

This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

Fabrication of cell container arrays with overlaid surface topographies

NARCIS (Netherlands)

Truckenmüller, Roman; Giselbrecht, Stefan; Escalante-Marun, Maryana; Groenendijk, Max; Papenburg, Bernke; Rivron, Nicolas; Unadkat, Hemant; Saile, Volker; Subramaniam, Vinod; van den Berg, Albert; van Blitterswijk, Clemens; Wessling, Matthias; Boer, Jan de; Stamatialis, Dimitrios

This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

La historia del uso de la soya en México, su valor nutricional y su efecto en la salud The importance of soy in Mexico, its nutritional value and effect on health

Directory of Open Access Journals (Sweden)

Nimbe Torres y Torres

2009-06-01

Full Text Available La proteína de soya se ha utilizado en algunos países latinoamericanos, incluido México, en diversos programas de alimentación; el propósito ha sido el de mejorar el estado nutricional de la población debido a su elevado valor nutricio y su costo relativamente bajo que mantuvo por algún tiempo. En este trabajo se describen los usos y la investigación que se ha llevado a cabo sobre la soya en México desde 1970. Además, se revisan los efectos de los diferentes componentes de la soya, en particular de su proteína y las isoflavonas, sobre la salud, su mecanismo de acción en la reducción del colesterol y los triglicéridos y la disminución de la secreción de insulina, así como su respuesta glucémica; por último, se delinean las recomendaciones del consumo de la proteína de soya parar obtener un beneficio en la salud.Soy protein has been used in several Latin-American countries including Mexico in various food programs with the purpose to improve the nutritional status of the population due to the high nutritional value and its relatively low cost that was maintained for some time. In the present work, the use and research on soy in Mexico since 1970 is described. In addition, this review shows the effects of the different components of soy, in particular its protein and the isoflavones on health, the mechanism of action of soy protein to reduce cholesterol and triglycerides, and insulin secretion, as well as its glycemic response, and finally, the recommendations of soy protein consumption to obtain a health benefit.

Vortices in the SU(N) x SU(N) spin systems in two dimensions

International Nuclear Information System (INIS)

Kares, R.J.D.

1982-01-01

The SU(N) x SU(N) or chiral spin systems in two dimensions with spin variables in both the fundamental and the adjoint representations of SU(N) are considered. In the adjoint representation the chiral models are found to possess topologically stable, classical vortex solutions which carry a Z(N) topological charge. A relationship is established between the chiral models and massive Yang-Mills theory in two dimensions. This relationship is exploited to prove the asymptotic freedom of the chiral models and to find their weak coupling mass gap. The connection between the vortices of the chiral models and those of the massive Yang-Mills theory is discussed. The behavior of a gas of vortices in the SU(2) chiral model is considered. This gas is converted to an equivalent field theory and studied using the renormalization group. It is shown that the SU(2) vortex gas does not undergo a Kosterlitz-Thouless phase transition. This behavior probably persists for the higher SU(N) groups as well. Finally, using the massive Yang-Mills theory the effect of the coupling of vortices to spin wave fluctuations is investigated. It is argued that as a result of the vortex-spin wave interaction the vortices acquire a mass scale dynamically. A self consistency condition is derived for the vortex scale and used to compute the mass gap for the chiral models in the presence of vortices. The mass gap obtained in this way is found to be in agreement with the weak coupling result suggesting that vortices may be responsible for generating the mass gap in the chiral models near T = 0

Integrable multi parametric SU(N) chain

International Nuclear Information System (INIS)

Foerster, Angela; Roditi, Itzhak; Rodrigues, Ligia M.C.S.

1996-03-01

We analyse integrable models associated to a multi parametric SU(N) R-matrix. We show that the Hamiltonians describe SU(N) chains with twisted boundary conditions and that the underlying algebraic structure is the multi parametric deformation of SU(N) enlarged by the introduction of a central element. (author). 15 refs

Finite size giant magnons in the SU(2) x SU(2) sector of AdS4 x CP3

International Nuclear Information System (INIS)

Lukowski, Tomasz; Sax, Olof Ohlsson

2008-01-01

We use the algebraic curve and Luescher's μ-term to calculate the leading order finite size corrections to the dispersion relation of giant magnons in the SU(2) x SU(2) sector of AdS 4 x CP 3 . We consider a single magnon as well as one magnon in each SU(2). In addition the algebraic curve computation is generalized to give the leading order correction for an arbitrary multi-magnon state in the SU(2) x SU(2) sector.

Analysis list: Su(var)205 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Su(var)205 Adult,Embryo,Larvae + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3.../target/Su(var)205.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Su(var)205.5.tsv http://dbarc...hive.biosciencedbc.jp/kyushu-u/dm3/target/Su(var)205.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/c...olo/Su(var)205.Adult.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Su(var)205.Embryo.tsv,http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Su(var)205.Larvae.tsv http://dbarchive

Dimensional reduction of exceptional E6,E8 gauge groups and flavour chirality

International Nuclear Information System (INIS)

Koca, M.

1984-01-01

Ten-dimensional Yang - Mills gauge theories based on the exceptional groups E 6 and E 8 are reduced to four-dimensional flavour-chiral Yang - Mills - Higgs theories where the extra six dimensions are identified with the compact G 2 /SU(3) and SO(7)/SO(6) coset spaces. A ten-dimensional E 8 theory leads to three families of SU(5), one of which lies in the 144-dimensional representation of SO(10)

Phenomenology with supersymmetric flipped SU(6)

Energy Technology Data Exchange (ETDEWEB)

Shafi, Qaisar E-mail: shafi@bartol.udel.edu; Tavartkiladze, Zurab E-mail: tavzur@axpfe1.fe.infn.it

1999-07-12

The supersymmetric flipped SU(6) x U(1) gauge symmetry can arise through compactification of the ten-dimensional E{sub 8} x E{sub 8} superstring theory. We show how realistic phenomenology can emerge from this theory by supplementing it with the symmetry R x U(1), where R denotes a discrete 'R'-symmetry. The well-known doublet-triplet splitting problem is resolved to 'all orders' via the pseudo-Goldstone mechanism, and the GUT scale arises from an interplay of the Planck and supersymmetry breaking scales. The symmetry R x U(1) is also important for understanding the fermion mass hierarchies as well as the magnitudes of the CKM matrix elements. Furthermore, the well-known MSSM parameter tan {beta} is estimated to be of order unity, while the proton lifetime ({tau}{sub p} {approx} 10{sup 2}{tau}{sub pSU(5)}) is consistent with observations. Depending on some parameters, p {yields} K{mu}{sup +} can be the dominant decay mode. Finally, the observed solar and atmospheric neutrino 'anomalies' requir us to introduce a 'sterile' neutrino state. Remarkably, the R x U(1) symmetry protects it from becoming heavy, so that maximal angle {nu}{sub {mu}} oscillations into a sterile state can explain the atmospheric anomaly, while the solar neutrino puzzle is resolved via the small angle {nu}{sub e} - {nu}{sub {tau}} MSW oscillations. The existence of some ({approx} 15-20% of critical energy density) neutrino hot dark matter is also predicted.

Closed flux tubes in D=2+1SU(N) gauge theories: dynamics and effective string description

Energy Technology Data Exchange (ETDEWEB)

Athenodorou, Andreas [Department of Physics, University of Cyprus,POB 20537, 1678 Nicosia (Cyprus); Computation-based Science and Technology Research Center, The Cyprus Institute,20 Kavafi Str., Nicosia 2121 (Cyprus); Teper, Michael [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford OX1 3NP (United Kingdom)

2016-10-18

We extend our earlier calculations of the spectrum of closed flux tubes in SU(N) gauge theories in 2+1 dimensions, with a focus on questions raised by recent theoretical progress on the effective string action of long flux tubes and the world-sheet action for flux tubes of moderate lengths. Our new calculations in SU(4) and SU(8) provide evidence that the leading O(1/l{sup γ}) non-universal correction to the flux tube ground state energy does indeed have a power γ≥7. We perform a study in SU(2), where we can traverse the length at which the Nambu-Goto ground state becomes tachyonic, to obtain an all-N view of the spectrum. Our comparison of the k=2 flux tube excitation energies in SU(4) and SU(6) suggests that the massive world sheet excitation associated with the k=2 binding has a scale that knows about the group and hence the theory in the bulk, and we comment on the potential implications of world sheet massive modes for the bulk spectrum. We provide a quantitative analysis of the surprising (near-)orthogonality of flux tubes carrying flux in different SU(N) representations, which implies that their screening by gluons is highly suppressed even at small N.

Closed flux tubes in D=2+1SU(N) gauge theories: dynamics and effective string description

International Nuclear Information System (INIS)

Athenodorou, Andreas; Teper, Michael

2016-01-01

We extend our earlier calculations of the spectrum of closed flux tubes in SU(N) gauge theories in 2+1 dimensions, with a focus on questions raised by recent theoretical progress on the effective string action of long flux tubes and the world-sheet action for flux tubes of moderate lengths. Our new calculations in SU(4) and SU(8) provide evidence that the leading O(1/l"γ) non-universal correction to the flux tube ground state energy does indeed have a power γ≥7. We perform a study in SU(2), where we can traverse the length at which the Nambu-Goto ground state becomes tachyonic, to obtain an all-N view of the spectrum. Our comparison of the k=2 flux tube excitation energies in SU(4) and SU(6) suggests that the massive world sheet excitation associated with the k=2 binding has a scale that knows about the group and hence the theory in the bulk, and we comment on the potential implications of world sheet massive modes for the bulk spectrum. We provide a quantitative analysis of the surprising (near-)orthogonality of flux tubes carrying flux in different SU(N) representations, which implies that their screening by gluons is highly suppressed even at small N.

Microcontainers for Intestinal Drug Delivery

DEFF Research Database (Denmark)

Tentor, Fabio; Mazzoni, Chiara; Keller, Stephan Sylvest

Among all the drug administration routes, the oral one is the most preferred by the patients being less invasive, faster and easier. Oral drug delivery systems designed to target the intestine are produced by powder technology and capsule formulations. Those systems including micro- and nano...

Maintainability allocation

International Nuclear Information System (INIS)

Guyot, Christian.

1980-06-01

The author gives the general lines of a method for the allocation and for the evaluation of maintainability of complex systems which is to be developed during the conference. The maintainability objective is supposed to be formulated under the form of a mean time to repair (M.T.T.R.) [fr

Thermodynamics of one-dimensional SU(4) and SU(6) fermions with attractive interactions

Science.gov (United States)

Hoffman, M. D.; Loheac, A. C.; Porter, W. J.; Drut, J. E.

2017-03-01

Motivated by advances in the manipulation and detection of ultracold atoms with multiple internal degrees of freedom, we present a finite-temperature lattice Monte Carlo calculation of the density and pressure equations of state, as well as Tan's contact, of attractively interacting SU(4)- and SU(6)-symmetric fermion systems in one spatial dimension. We also furnish a nonperturbative proof of a universal relation whereby quantities computable in the SU(2) case completely determine the virial coefficients of the SU(Nf) case. These one-dimensional systems are appealing because they can be experimentally realized in highly constrained traps and because of the dominant role played by correlations. The latter are typically nonperturbative and are crucial for understanding ground states and quantum phase transitions. While quantum fluctuations are typically overpowered by thermal ones in one and two dimensions at any finite temperature, we find that quantum effects do leave their imprint in thermodynamic quantities. Our calculations show that the additional degrees of freedom, relative to the SU(2) case, provide a dramatic enhancement of the density and pressure (in units of their noninteracting counterparts) in a wide region around vanishing β μ , where β is the inverse temperature and μ the chemical potential. As shown recently in experiments, the thermodynamics we explore here can be measured in a controlled and precise fashion in highly constrained traps and optical lattices. Our results are a prediction for such experiments in one dimension with atoms of high nuclear spin.

Reason for SU(6) grand unification

International Nuclear Information System (INIS)

Kim, J.E.

1981-08-01

An SU(6) model can naturally guarantee strong CP invariance. This also includes Georgi and Glashow's SU(5) model. The axion in this model can be either invisible or visible, depending on the symmetry breaking scheme. The invisible axion is identical to a Majoron. Also, there exists a relationship between 24sub(H) and 45sub(H) of SU(5). (author)

Independent SU(2)-loop variables

International Nuclear Information System (INIS)

Loll, R.

1991-04-01

We give a reduction procedure for SU(2)-trace variables and introduce a complete set of indepentent, gauge-invariant and almost local loop variables for the configuration space of SU(2)-lattice gauge theory in 2+1 dimensions. (orig.)

SU(5) monopoles, magnetic symmetry and confinement

International Nuclear Information System (INIS)

Daniel, M.; Lazarides, G.; Shafi, Q.

1980-01-01

The monopoles of the unified SU(5) gauge theory broken down to Hsub(E) = SU(3)sub(c) x U(1)sub(EM) [or to Ksub(E) = SU(3)sub(c) x SU(2) x U(1)sub(γ)], are classified. They belong to representations of a magnetic group Hsub(M)(Ksub(M)), which is found to be isomorphic to Hsub(E)(Ksub(E)). For SU(5) broken down to Hsub(E), there exists a regular and stable monopole which is a colour magnetic triplet, and carries a non-zero abelian magnetic charge. It is suggested that composite operators made out of this monopole and its antiparticle fields develop a non-zero vacuum expectation value, and so lead to a squeezing of the colour electric flux. Finally, we comment on the cosmological production of SU(5) monopoles. (orig.)

La larva de Hyla uruguaya Schmidt, 1944 (Anura: Hylidae, con comentarios sobre su biología y su status taxonómico

Directory of Open Access Journals (Sweden)

Kolenc, Francisco

2003-11-01

Full Text Available Hyla uruguaya es una especie poco conocida y con relaciones taxonómicas discutidas. Su hallazgo en Uruguay ha sido esporádico. En el presente trabajo se describen su morfología larval, aspectos sobre su biología reproductiva, geonemia y ecología en Uruguay. La larva tiene cuerpo de tipo robusto y elíptico, con ojos laterales, aletas altas con dorsal expandida, espiráculo izquierdo, tubo proctodeal dextrógiro y corto, y fórmula de queratodontes [(1(1-1/(1-1(2], con una fila simple de papilas orales con claro rostral y varias papilas intramarginales subangulares. Una puesta obtenida en el laboratorio consistió de 398 huevos de 1,3 mm de diámetro. El canto de anuncio consta de una sucesión de notas multipulsadas de 22 ms de duración, con una frecuencia dominante promedio de 4146 Hz, emitidas a una frecuencia de 4,2 - 4,8 notas/s. El tren de notas puede durar hasta 13 minutos. Su canto fue registrado en la naturaleza desde fines de agosto y sus larvas se encontraron hasta fines de febrero en charcos de áreas abiertas en paisajes serranos del NE, E y SE del Uruguay. Los resultados obtenidos permitirían reconsiderar el estado de conservación de la especie en Uruguay. Sugerimos su afinidad taxonómica con las especies de Scinax del clado ruber sobre la base de caracteres larvales y discutimos su relación con la especie críptica Hyla pinima. Hyla uruguaya is a poorly known species with controversial taxonomic status. Its finding in Uruguay has been sporadic. In the present work larval morphology, some aspects of reproductive biology, geographical distribution and ecology in Uruguay are addressed. The tadpole has a robust and elliptic body, lateral eyes, high fins, left spiracle, vent tube short and dextral, labial tooth row formula of [(1(1-1/(1-1(2], a single row of oral papillae with a dorsal gap and some submarginal subangular papillae. A spawn of 398 eggs of 1,3 mm diameter was obtained in the laboratory. The advertisement call

Luis Felipe Fajardo (1927-2013. Su vida y su obra

Directory of Open Access Journals (Sweden)

Hernando Sarasti Obregón

2017-09-01

Full Text Available FragmentoTeniendo en cuenta los grandes logros de este médico colombiano, en la Academia Nacional de Medicina se le rindió un homenaje a su memoria. Los ponentes de la sesión fueron los académicos Sarasti y Patiño. Por lo importante del tema, hemos querido incluir sus presentaciones en este artículo de la revista MEDICINA. El tema tocado por el doctor Sarasti fue el siguiente:El 5 de julio de 2013 falleció en los Estados Unidos en la ciudad de Palo Alto, California, el patólogo colombiano Dr. Luis Felipe Fajardo Lobo- Guerrero. Había nacido en Bogotá el 23 de enero de 1927 en el hogar de Don Luís Antonio Fajardo Suárez y Doña María Teresa Lobo-Guerrero.Se graduó como Bachiller en el Colegio de La Salle en 1944, hizo su medicatura rural en Restrepo (Meta y recibió el título de Médico en la Facultad de Medicina de la Universidad Nacional de Colombia en 1952. Inició su entrenamiento en Patología en el Hospital San Juan de Dios de Bogotá y lo continuó en los Estados Unidos en la Universidad de Yale entre 1954 y 1958. Ese mismo año fue certificado por el American Board of Pathology, contrajo matrimonio con Lorela Enterline y regresó a Colombia a ejercer su especialidad en el Hospital de la Samaritana.En noviembre de 1959 volvió a los Estados Unidos para ocupar un “locum tenens” en Connecticut en el New Britain General Hospital y regresó nuevamente a Colombia en octubre de 1960 como Profesor Asistente de Patología de la Universidad Nacional al mismo tiempo que fue Jefe del Laboratorio Clínico del Hospital San Juan de Dios.El Dr. Fajardo y el suscrito formábamos parte de la generación de médicos colombianos que hacia mediados del siglo XX viajamos a los Estados Unidos para especializarnos en diversas ramas de la Medicina.

How supersymmetry naturally suppresses Higgs-boson-mediated baryon-number violation in SU/sub c/(4) x SU/sub L/(2) x SU/sub R/(2) and SO(10)

International Nuclear Information System (INIS)

Gipson, J.M.; Marshak, R.E.

1984-01-01

The supersymmetric versions of the left-right-symmetric SU/sub C/(4) x SU/sub L/(2) x SU/sub R/(2) Pati-Salam theory and the grand unified SO(10) theory are studied. In the minimal versions of these models the requirement of soft or spontaneous breaking of supersymmetry, together with renormalizibility, leads to an accidental global U(1) symmetry which leads to baryon-number conservation. A necessary condition for this symmetry to be broken is the existence of fields which are antisymmetric in at least two SU/sub C/(4) indices. The introduction of such fields may allow for observable neutron oscillation

Complex open-framework germanate built by 8-coordinated Ge 10 clusters

KAUST Repository

Yue, Huijuan

2012-11-19

A novel open-framework germanate |(C 5H 14N 2) 2(C 5H 12N 2) 0.5(H 2O) 2.5|[Ge 12.5O 26(OH) 2] with three-dimensional 10- and 11-ring channels, denoted as SU-67, has been synthesized under hydrothermal conditions using 2-methylpiperazine (MPP) as the structure-directing agent (SDA). The synthesis is intimately related to that of JLG-5, a tubular germanate built from Ge 7 clusters. The influences of synthesis parameters are discussed. A strong influence of the hydrofluoric acid quantity on the resulting cluster building units can be concluded. The framework of SU-67 is based on an elaborate topological pattern of connected Ge 10 clusters forming intersecting 10- and 11-ring channels and has a low framework density (12.4 Ge atoms per 1000 ̊ 3). We have discovered that the topology of SU-67 is a new 8-connected nce-8-I4 1/acd net. Strong hydrogen bonding among the organic SDAs, water molecules, and Ge 10 clusters resulted in helical networks in SU-67. © 2012 American Chemical Society.

Proton beam writing on PMMA and SU-8 films as a tool for development of micro-structures for organic electronics

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Mihir, E-mail: mihirs@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Shukla, Neeraj; Banerji, Nobin [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Mohapatra, Y.N. [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Samtel Center for Display Technologies, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

2012-02-15

Proton beam writing is a maskless lithographic technique for the fabrication of 3D micro and nano structures in polymers. The fabricated structures find application in micro fluidics, optics, biosensors, etc. We use proton beam writing for micro-patterning in polymers which will facilitate fabrication of test structures for micro-components of micro-fluidic devices, organic thin film transistors (OTFT) and organic light emitting diodes (OLED). In this paper we report fabrication of varying width micro channels in PMMA and SU-8 films used as positive and negative resists respectively. The patterns were written using 2 MeV proton beam focused down to around 1 micron. We have achieved clean periodic micro-channels of width varying from few micrometers to wider ones in both the resists. Being a mask less lithography it provides an efficient way of reducing turnaround time for test structures with several channel widths and patterns being conveniently written at the same development cycle. Possible applications of the patterned structures in OLED/TFT are discussed. Additional structures like checkered board are also fabricated. Optimized fluence for both the resist has been determined.

′Metal to resin′: A comparative evaluation of conventional band and loop space maintainer with the fiber reinforced composite resin space maintainer in children

Directory of Open Access Journals (Sweden)

A Garg

2014-01-01

Full Text Available Aims: To compare the clinical efficacy of two space maintainers namely, conventional band and loop and Fiber Reinforced Composite Resin (FRCR space maintainers . Subjects and Methods: Thirty healthy children, aged 5 to 8 years were selected having at least two deciduous molars in different quadrants indicated for extraction or lost previously. FRCR space maintainer was placed in one quadrant and in the other quadrant band and loop space maintainer was cemented. All the patients were recalled at 1 st , 3 rd , and 6 th months for evaluation of both types of space maintainer. Patient acceptability, time taken, and clinical efficacy was recorded. Statistical analysis used: The observations thus obtained were subjected to statistical analysis using Chi- square test and Mann-Whitney U test. Results: Patient acceptability was greater in Group I (FRCR in comparison to Group II (band and loop space maintainer. The time taken by Group I was significantly lower as compared to that of Group II. In Group I, debonding of enamel, composite was the most common complication leading to failure followed by debonding of fiber composite. In Group II, cement loss was the most common complication leading to failure followed by slippage of band and fracture of loop. The success rates of Groups I and Group II weares 63.3% and 36.7%, respectively. Conclusion: The study concluded that FRCRFiber Reinforced Composite Resin (Ribbond space maintainers can be considered as viable alternative to the conventional band and loop space maintainers.

Weak mixing angle and the SU(3)CxSU(3) model on M4xS1/(Z2xZ'2)

International Nuclear Information System (INIS)

Li Tianjun; Wei Liao

2002-05-01

We show that the desirable weak mixing angle sin 2 θ W =0.2312 at m Z scale can be generated naturally in the SU(3) C xSU(3) model on M 4 xS 1 /(Z 2 x Z 2 ') where the gauge symmetry SU(3) is broken down to SU(2) L xU(1) Y by orbifold projection. For a supersymmetric model with a TeV scale extra dimension, the SU(3) unification scale is about hundreds of TeVs at which the gauge couplings for SU(3) C and SU(3) can also be equal in the mean time. For the non-supersymmetric model, SU(2) L xU(1) Y are unified at order of 10 TeV. These models may serve as good candidates for physics beyond the SM or MSSM. (author)

Coherent states for polynomial su(2) algebra

International Nuclear Information System (INIS)

Sadiq, Muhammad; Inomata, Akira

2007-01-01

A class of generalized coherent states is constructed for a polynomial su(2) algebra in a group-free manner. As a special case, the coherent states for the cubic su(2) algebra are discussed. The states so constructed reduce to the usual SU(2) coherent states in the linear limit

SU(3)_C× SU(2)_L× U(1)_Y( × U(1)_X ) as a symmetry of division algebraic ladder operators

Science.gov (United States)

Furey, C.

2018-05-01

We demonstrate a model which captures certain attractive features of SU(5) theory, while providing a possible escape from proton decay. In this paper we show how ladder operators arise from the division algebras R, C, H, and O. From the SU( n) symmetry of these ladder operators, we then demonstrate a model which has much structural similarity to Georgi and Glashow's SU(5) grand unified theory. However, in this case, the transitions leading to proton decay are expected to be blocked, given that they coincide with presumably forbidden transformations which would incorrectly mix distinct algebraic actions. As a result, we find that we are left with G_{sm} = SU(3)_C× SU(2)_L× U(1)_Y / Z_6. Finally, we point out that if U( n) ladder symmetries are used in place of SU( n), it may then be possible to find this same G_{sm}=SU(3)_C× SU(2)_L× U(1)_Y / Z_6, together with an extra U(1)_X symmetry, related to B-L.

Ergonomics Contribution in Maintainability

Science.gov (United States)

Teymourian, Kiumars; Seneviratne, Dammika; Galar, Diego

2017-09-01

The objective of this paper is to describe an ergonomics contribution in maintainability. The economical designs, inputs and training helps to increase the maintainability indicators for industrial devices. This analysis can be helpful, among other cases, to compare systems, to achieve a better design regarding maintainability requirements, to improve this maintainability under specific industrial environment and to foresee maintainability problems due to eventual changes in a device operation conditions. With this purpose, this work first introduces the notion of ergonomics and human factors, maintainability and the implementation of assessment of human postures, including some important postures to perform maintenance activities. A simulation approach is used to identify the critical posture of the maintenance personnel and implements the defined postures with minimal loads on the personnel who use the equipment in a practical scenario. The simulation inputs are given to the designers to improve the workplace/equipment in order to high level of maintainability. Finally, the work concludes summarizing the more significant aspects and suggesting future research.

An SU(2) x SU(2) symmetric Higgs-Fermion model with staggered fermions

International Nuclear Information System (INIS)

Berlin, J.; Heller, U.M.

1991-01-01

We have simulated on SU(2)xSU(2) symmetric Higgs-Fermion model with a four component scalar field coupled with a Yukawa type coupling to two flavours of staggered fermions. The results show two qualitatively different behaviours in the broken phase. One for weak coupling where the fermion masses obey the perturbative tree level relation M F =y , and one for strong coupling where the behaviour agrees with a 1/d expansion. (orig.)

N = 8 BPS black holes preserving 1/8 supersymmetry

Science.gov (United States)

Bertolini, M.; Frè, P.; Trigiante, M.

1999-05-01

In the context of N = 8 supergravity we consider BPS black holes that preserve 1/8 supersymmetry. It was shown in a previous paper that, modulo U-duality transformations of E7(7), the most general solution of this type can be reduced to a black hole of the STU model. In this paper we analyse this solution in detail, considering in particular its embedding in one of the possible special Kähler manifolds compatible with the consistent truncations to N = 2 supergravity, this manifold being the moduli space of the T6/icons/Journals/Common/BbbZ" ALT="BbbZ" ALIGN="MIDDLE"/>3 orbifold, that is SU(3,3)/SU(3) × U(3). This construction requires a crucial use of the solvable Lie algebra formalism. Once the group-theoretical analysis is done, starting from a static, spherically symmetric ansatz, we find an exact solution for all the scalars (both dilaton- and axion-like) and for gauge fields, together with their already known charge-dependent fixed values, which yield a U-duality-invariant entropy. We also give a complete translation dictionary between the solvable Lie algebra and the special Kähler formalisms in order to allow a more immediate comparison with other papers on similar issues. Although the explicit solution is given in a simplified case where the equations turn out to be more manageable, it encodes all the features of the more general one, namely it has non-vanishing entropy and the scalar fields have a non-trivial radial dependence.

La democracia y su calidad

Directory of Open Access Journals (Sweden)

Antonio de Cabo de la Vega

2012-06-01

Full Text Available En el presente artículo se abordan la cuestión teórica del papel de la democracia representativa en las constituciones de los Estados capitalistas y algunos debates en torno a su definición y calidad que han tratado de orientar su comprensión y funcionamiento efectivos.

Tribo-functionalizing Si and SU8 materials by surface modification for application in MEMS/NEMS actuator-based devices

International Nuclear Information System (INIS)

Singh, R A; Satyanarayana, N; Sinha, S K; Kustandi, T S

2011-01-01

Micro/nano-electro-mechanical-systems (MEMS/NEMS) are miniaturized devices built at micro/nanoscales. At these scales, the surface/interfacial forces are extremely strong and they adversely affect the smooth operation and the useful operating lifetimes of such devices. When these forces manifest in severe forms, they lead to material removal and thereby reduce the wear durability of the devices. In this paper, we present a simple, yet robust, two-step surface modification method to significantly enhance the tribological performance of MEMS/NEMS materials. The two-step method involves oxygen plasma treatment of polymeric films and the application of a nanolubricant, namely perfluoropolyether. We apply the two-step method to the two most important MEMS/NEMS structural materials, namely silicon and SU8 polymer. On applying surface modification to these materials, their initial coefficient of friction reduces by ∼4-7 times and the steady-state coefficient of friction reduces by ∼2.5-3.5 times. Simultaneously, the wear durability of both the materials increases by >1000 times. The two-step method is time effective as each of the steps takes the time duration of approximately 1 min. It is also cost effective as the oxygen plasma treatment is a part of the MEMS/NEMS fabrication process. The two-step method can be readily and easily integrated into MEMS/NEMS fabrication processes. It is anticipated that this method will work for any kind of structural material from which MEMS/NEMS are or can be made.

Tribo-functionalizing Si and SU8 materials by surface modification for application in MEMS/NEMS actuator-based devices

Science.gov (United States)

Singh, R. A.; Satyanarayana, N.; Kustandi, T. S.; Sinha, S. K.

2011-01-01

Micro/nano-electro-mechanical-systems (MEMS/NEMS) are miniaturized devices built at micro/nanoscales. At these scales, the surface/interfacial forces are extremely strong and they adversely affect the smooth operation and the useful operating lifetimes of such devices. When these forces manifest in severe forms, they lead to material removal and thereby reduce the wear durability of the devices. In this paper, we present a simple, yet robust, two-step surface modification method to significantly enhance the tribological performance of MEMS/NEMS materials. The two-step method involves oxygen plasma treatment of polymeric films and the application of a nanolubricant, namely perfluoropolyether. We apply the two-step method to the two most important MEMS/NEMS structural materials, namely silicon and SU8 polymer. On applying surface modification to these materials, their initial coefficient of friction reduces by ~4-7 times and the steady-state coefficient of friction reduces by ~2.5-3.5 times. Simultaneously, the wear durability of both the materials increases by >1000 times. The two-step method is time effective as each of the steps takes the time duration of approximately 1 min. It is also cost effective as the oxygen plasma treatment is a part of the MEMS/NEMS fabrication process. The two-step method can be readily and easily integrated into MEMS/NEMS fabrication processes. It is anticipated that this method will work for any kind of structural material from which MEMS/NEMS are or can be made.

Finite subgroups of SU(3)

International Nuclear Information System (INIS)

Bovier, A.; Lueling, M.; Wyler, D.

1980-12-01

We present a new class of finite subgroups of SU(3) of the form Zsub(m) s zsub(n) (semidirect product). We also apply the methods used to investigate semidirect products to the known SU(3) subgroups Δ(3n 2 ) and Δ(6n 2 ) and give analytic formulae for representations (characters) and Clebsch-Gordan coefficients. (orig.)

Diversity of off-shell twisted (4,4) multiplets in SU(2)xSU(2) harmonic superspace

International Nuclear Information System (INIS)

Ivanov, E.A.; Sutulin, A.O.

2004-01-01

We elaborate on four different types of twisted N=(4,4) supermultiplets in the SU(2)xSU(2), 2D harmonic superspace. In the conventional N=(4,4), 2D superspace they are described by the superfields q ia , q Ia , q IA , subjected to proper differential constraints, (i, I, a, A) being the doublet indices of four groups SU(2) which form the full R-symmetry group SO(4) L xSO(4) R of N=(4,4) supersymmetry. We construct the torsionful off-shell sigma-model actions for each type of these multiplets, as well as the corresponding invariant mass terms, in an analytic subspace of the SU(2)xSU(2) harmonic superspace. As an instructive example, N=(4,4) superconformal extension of the SU(2)xU(1) WZNW sigma-model action and its massive deformation are presented for the multiplet q iA . We prove that N=(4,4) supersymmetry requires the general sigma-model action of pair of different multiplets to split into a sum of sigma-model actions of each multiplet. This phenomenon also persists if a larger number of non-equivalent multiplets are simultaneously included. We show that different multiplets may interact with each other only through mixed mass terms which can be set up for multiplets belonging to 'self-dual' pairs (q ia , q IA ) and (q Ia , q iA ). The multiplets from different pairs cannot interact at all. For a 'self-dual' pair of the twisted multiplets we give the most general form of the on-shell scalar potential

Phase-structure of SU(3) lattice gauge-higgs model

International Nuclear Information System (INIS)

Gerdt, V.P.; Mitrjushkin, V.K.; Zadorozhny, A.M.

1985-01-01

Phase structure is investigated of SU(3) symmetric gauge-Higgs theory with a defrost radial mode. The Higgs fields are considered in the fundamental representation of SU(3) group. It is shown that the phase structures of SU(3) and SU(2) symmetric coincide qualitatively

Semidirect product gauge group [SU(3)cxSU(2)L]xU(1)Y and quantization of hypercharge

International Nuclear Information System (INIS)

Hattori, Chuichiro; Matsunaga, Mamoru; Matsuoka, Takeo

2011-01-01

In the standard model the hypercharges of quarks and leptons are not determined by the gauge group SU(3) c xSU(2) L xU(1) Y alone. We show that, if we choose the semidirect product group [SU(3) c xSU(2) L ]xU(1) Y as its gauge group, the hyperchages are settled to be n/6 mod Z(n=0,1,3,4). In addition, the conditions for gauge-anomaly cancellation give strong constraints. As a result, the ratios of the hypercharges are uniquely determined and the gravitational anomaly is automatically canceled. The standard charge assignment to quarks and leptons can be properly reproduced. For exotic matter fields their hypercharges are also discussed.

Transporters MCT8 and OATP1C1 maintain murine brain thyroid hormone homeostasis

NARCIS (Netherlands)

Mayerl, Steffen; Müller, Julia; Bauer, Reinhard; Richert, Sarah; Kassmann, Celia M.; Darras, Veerle M.; Buder, Katrin; Boelen, Anita; Visser, Theo J.; Heuer, Heike

2014-01-01

Allan-Herndon-Dudley syndrome (AHDS), a severe form of psychomotor retardation with abnormal thyroid hormone (TH) parameters, is linked to mutations in the TH-specific monocarboxylate transporter MCT8. In mice, deletion of Mct8 (Mct8 KO) faithfully replicates AHDS-associated endocrine abnormalities;

The algebra and geometry of SU(3) matrices

International Nuclear Information System (INIS)

Mallesh, K.S.; Mukunda, N.

1997-01-01

We give an elementary treatment of the defining representation and Lie algebra of the three-dimensional unitary unimodular group SU(3). The geometrical properties of the Lie algebra, which is an eight dimensional real linear vector space, are developed in an SU(3) covariant manner. The f and d symbols of SU(3) lead to two ways of multiplying two vectors to produce a third, and several useful geometric and algebraic identities are derived. The axis-angle parametrization of SU(3) is developed as a generalization of that for SU(2), and the specifically new features are brought out. Application to the dynamics of three-level system is outlined. (author)

Analysis list: Su(z)12 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Su(z)12 Embryo,Larvae + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/S...u(z)12.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Su(z)12.5.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/target/Su(z)12.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Su(z)12.Embryo....tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Su(z)12.Larvae.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/Embryo.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Larvae.gml ...

Independent SU(2)-loop variables and the reduced configuration space of SU(2)-lattice gauge theory

International Nuclear Information System (INIS)

Loll, R.

1992-01-01

We give a reduction procedure for SU(2)-trace variables and an explicit description of the reduced configuration sace of pure SU(2)-gauge theory on the hypercubic lattices in two, three and four dimensions, using an independent subset of the gauge-invariant Wilson loops. (orig.)

Liquid immersion thermal crosslinking of 3D polymer nanopatterns for direct carbonisation with high structural integrity

Science.gov (United States)

Kang, Da-Young; Kim, Cheolho; Park, Gyurim; Moon, Jun Hyuk

2015-12-01

The direct pyrolytic carbonisation of polymer patterns has attracted interest for its use in obtaining carbon materials. In the case of carbonisation of nanopatterned polymers, the polymer flow and subsequent pattern change may occur in order to relieve their high surface energies. Here, we demonstrated that liquid immersion thermal crosslinking of polymer nanopatterns effectively enhanced the thermal resistance and maintained the structure integrity during the heat treatment. We employed the liquid immersion thermal crosslinking for 3D porous SU8 photoresist nanopatterns and successfully converted them to carbon nanopatterns while maintaining their porous features. The thermal crosslinking reaction and carbonisation of SU8 nanopatterns were characterised. The micro-crystallinity of the SU8-derived carbon nanopatterns was also characterised. The liquid immersion heat treatment can be extended to the carbonisation of various polymer or photoresist nanopatterns and also provide a facile way to control the surface energy of polymer nanopatterns for various purposes, for example, to block copolymer or surfactant self-assemblies.

SU (2) with fundamental fermions and scalars

DEFF Research Database (Denmark)

Hansen, Martin; Janowski, Tadeusz; Pica, Claudio

2018-01-01

We present preliminary results on the lattice simulation of an SU(2) gauge theory with two fermion flavors and one strongly interacting scalar field, all in the fundamental representation of SU(2). The motivation for this study comes from the recent proposal of "fundamental" partial compositeness...... the properties of light meson resonances previously obtained for the SU(2) model. Preprint: CP3-Origins-2017-047 DNRF90...

Nonperturbative β function of eight-flavor SU(3) gauge theory

Science.gov (United States)

Hasenfratz, Anna; Schaich, David; Veernala, Aarti

2015-06-01

We present a new lattice study of the discrete β function for SU(3) gauge theory with N f = 8 massless flavors of fermions in the fundamental representation. Using the gradient flow running coupling, and comparing two different nHYP-smeared staggered lattice actions, we calculate the 8-flavor step-scaling function at significantly stronger couplings than were previously accessible. Our continuum-extrapolated results for the discrete β function show no sign of an IR fixed point up to couplings of g 2 ≈ 14. At the same time, we find that the gradient flow coupling runs much more slowly than predicted by two-loop perturbation theory, reinforcing previous indications that the 8-flavor system possesses nontrivial strongly coupled IR dynamics with relevance to BSM phenomenology.

The Polyakov loop and its correlators in higher representations of SU(3) at finite temperature

International Nuclear Information System (INIS)

Huebner, K.A.

2006-09-01

We have calculated the Polyakov loop in representations D=3,6,8,10,15,15',24,27 and diquark and baryonic Polyakov loop correlation functions with fundamental sources in SU(3) pure gauge theory and 2-flavour QCD with staggered quarks and Q anti Q-singlet correlation functions with sources in the fundamental and adjoint representation in SU(3) pure gauge theory. We have tested a new renormalisation procedure for the Polyakov loop and extracted the adjoint Polyakov loop below T c , binding energy of the gluelump and string breaking distances. Moreover, we could show Casimir scaling for the Polyakov loop in different representations in SU(3) pure gauge theory above T c . Diquark antitriplet and baryonic singlet free energies are related to the Q anti Q-singlet free energies by the Casimir as well. (orig.)

The Polyakov loop and its correlators in higher representations of SU(3) at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Huebner, K.A.

2006-09-15

We have calculated the Polyakov loop in representations D=3,6,8,10,15,15',24,27 and diquark and baryonic Polyakov loop correlation functions with fundamental sources in SU(3) pure gauge theory and 2-flavour QCD with staggered quarks and Q anti Q-singlet correlation functions with sources in the fundamental and adjoint representation in SU(3) pure gauge theory. We have tested a new renormalisation procedure for the Polyakov loop and extracted the adjoint Polyakov loop below T{sub c}, binding energy of the gluelump and string breaking distances. Moreover, we could show Casimir scaling for the Polyakov loop in different representations in SU(3) pure gauge theory above T{sub c}. Diquark antitriplet and baryonic singlet free energies are related to the Q anti Q-singlet free energies by the Casimir as well. (orig.)

Gallego Aranda, Salvador. Cámara de Comercio de Melilla. Centenario de su Sede Social (1915-2015. Granada: Editorial Atrio, 2016, 205 pp. ISBN 978-84-15275-55-8

Directory of Open Access Journals (Sweden)

Juan Garzón Gómez

2017-06-01

Full Text Available Con la publicación del libro Cámara de Comercio de Melilla. Centenario de su Sede Social (1915-2015, Salvador Gallego da un paso más en su ingente y destacada labor investigadora sobre la Ciudad Autónoma de Melilla y su arquitectura tanto física como social. Es de agradecer así la edición de este libro que continúa completando, con incuestionable rigor, un importante corpus informativo que ha estado precedido por otros títulos entre los que cabe destacar Enrique Nieto. Un paseo por su arquitectura (2010, Los sonidos de la arquitectura (2012 o Cándido Lobera Girela (1871-1932. militar, periodista, político y escritor (2014 este último con la coautoría de María Rosa Marqués Leiva.

SU(5): to flip or not to flip

International Nuclear Information System (INIS)

Nanopoulos, D.V.; Wisconsin Univ., Madison,

1988-01-01

Flipped SU(5) possesses some unique features as a grand unified theory: elegant missing partner mechanism, see-saw neutrino masses, no Higgs adjoints. This last property makes flipped SU(5) the only known grand unified theory derivable from 4-dimensional superstrings. When derived from the superstrings, flipped SU(5) possesses, in addition a hierarchical fermion mass spectrum. All these recent developments involving flipped SU(5) are discussed in a detailed but simple way, including phenomenological consequences at low energies

El genio maligno de Suárez: Suárez y Descartes

OpenAIRE

Baciero Ruiz, Francisco Tadeo

2007-01-01

[ES] Tradicionalmente se ha considerado la filosofía cartesiana como un comienzo casi absoluto en la historia de la Filosofía. Sin embargo, las conocidas hipótesis del “genio maligno” y del “Dios engañador”, parte fundamental del artificio de la “duda metódica” en las Meditaciones metafísicas, se encuentran en la Disputación metafísica 9 de Suárez (la única mención de Suárez en todo Descartes, precisamente en las “Respuestas” a las Meditaciones). Parece claro, a partir de la correspondencia d...

Plasma suPAR is lowered by smoking cessation

DEFF Research Database (Denmark)

Eugen-Olsen, Jesper; Ladelund, Steen; Sørensen, Lars Tue

2016-01-01

BACKGROUND: Soluble urokinase plasminogen activator receptor (suPAR) is a stable inflammatory biomarker. In patients, suPAR is a marker of disease presence, severity and prognosis. In the general population, suPAR is predictive of disease development, such as diabetes and cardiovascular disease a...

CKM and PMNS mixing matrices from discrete subgroups of SU(2)

International Nuclear Information System (INIS)

Potter, Franklin

2015-01-01

Remaining within the realm of the Standard Model(SM) local gauge group, this first principles derivation of both the PMNS and CKM matrices utilizes quaternion generators of the three discrete (i.e., finite) binary rotational subgroups of SU(2) called [3,3,2], [4,3,2], and [5,3,2] for three lepton families in R 3 and four related discrete binary rotational subgroups [3,3,3], [4,3,3], [3,4,3], and [5,3,3] represented by four quark families in R 4 . The traditional 3x3 CKM matrix is extracted as a submatrix of the 4x4 CKM4 matrix. If these two additional quarks b' and t' of a 4th quark family exist, there is the possibility that the SM lagrangian may apply all the way down to the Planck scale. There are then numerous other important consequences. The Weinberg angle is derived using these same quaternion generators, and the triangle anomaly cancellation is satisfied even though there is an obvious mismatch of three lepton families to four quark families. In a discrete space, one can also use these generators to derive a unique connection from the electroweak local gauge group SU(2) L x U(1) Y acting in R 4 to the discrete group Weyl E 8 in R 8 . By considering Lorentz transformations in discrete (3,1)-D spacetime, one obtains another Weyl E 8 discrete symmetry group in R 8 , so that the combined symmetry is Weyl E 8 x Weyl E 8 = 'discrete' SO(9,1) in 10-D spacetime. This unique connection is in direct contrast to the 10 500 possible connections for superstring theory! (paper)

SU(6) quadrupole phonon model for even and odd nuclei and the SU(3) limit

Energy Technology Data Exchange (ETDEWEB)

Paar, V; Brant, S [Zagreb Univ. (Yugoslavia). Prirodoslovno Matematicki Fakultet; Canto, L F [Rio de Janeiro Univ. (Brazil). Inst. de Fisica; Leander, G [Lund Inst. of Tech. (Sweden). Dept. of Mathematical Physics; Oak Ridge National Lab., TN (USA)); Vouk, M [Zagreb Univ. (Yugoslavia). Computing Centre SRCE

1982-04-05

Analogous to the equivalence between the SU(6) quadrupole-phonon model (TQM) and the interacting boson model (IBM), the equivalence is pointed out for odd systems between the SU(6) particle quadrupole-phonon coupling model (PTQM) and the interacting boson-fermion model (IBFM). PTQM is formulated starting from the Dyson representation for the odd system. Different aspects of the SU(3) limit of TQM and PTQM are studied; the quadrupole-phonon block structure of rotational bands in even and odd nuclei and analytic expressions based on the coherent state; signature effects generated in PTQM; electromagnetic properties and correction factors for PTQM; overlaps of the PTQM analogs of Nilsson states with Coriolis-coupled Nilsson states and the relation to the rotational model representation.

The algebra and geometry of SU(3) matrices

OpenAIRE

Mallesh, KS; Mukunda, N

1997-01-01

We give an elementary treatment of the defining representation and Lie algebra of the three-dimensional unitary unimodular group SU(3). The geometrical properties of the Lie algebra, which is an eight dimensional real Linear vector space, are developed in an SU(3) covariant manner. The f and d symbols of SU(3) lead to two ways of 'multiplying' two vectors to produce a third, and several useful geometric and algebraic identities are derived. The axis-angle parametrization of SU(3) is developed...

Determination of the chiral SU(4) x SU(4) breaking parameters

International Nuclear Information System (INIS)

Das, K.P.; Deshpande, N.G.

1978-06-01

Broken chiral SU(4) x SU(4) symmetry: from the observed mass spectrum of pseudoscalar charmed mesons the symmetry breakig parameters of the theory could be solved. It is found that both vacuum and Hamiltonian breaking play an important role as far as charmed states are concerned. Purely from the masses of D and F mesons the current algebra mass ratio m/sub c//m/sub s/ < 5 is deduced. This differs greatly from values obtained using linear or quadratic mass formulas. Considering eta, eta', and eta/sub c/ mixing a good solution with m/sub c//m/sub s/ approx. 3.2 and (anti cc)/anti uu) approx. 5.67 is further obtained. 18 references

Unifying flipped SU(5) in five dimensions

International Nuclear Information System (INIS)

Barr, S.M.; Dorsner, Ilja

2002-01-01

It is shown that embedding a four-dimensional flipped SU(5) model in a five-dimensional SO(10) model preserves the best features of both flipped SU(5) and SO(10). The missing partner mechanism, which naturally achieves both doublet-triplet splitting and suppression of d=5 proton decay operators, is realized as in flipped SU(5), while the gauge couplings are unified as in SO(10). The masses of down quarks and charged leptons, which are independent in flipped SU(5), are related by the SO(10). Distinctive patterns of quark and lepton masses can result. The gaugino mass M 1 is independent of M 3 and M 2 , which are predicted to be equal

Estado Vital de la Materia. Su origen, su evolución y su futuro.

Directory of Open Access Journals (Sweden)

J. Hernando Ordoñez

2001-04-01

Full Text Available

En este artlculo se hacen algunas observaciones sobre un estado de la materia (estado vital, propuesto para reemplazar el de materia viva, que se usa habitualmente.

La materia en estado vital se organiza por una fuerza interna, que podríamos calificar como inteligente, que hace que los átomos se orienten y se organicen con determinada finalidad para fabricar células, para modelar órganos y, éstos, para culminar su obra integrándose con la armonía más admirable, para constituirse en organismos ya sea vegetales o animales.

Los planetas no tienen materia en estado vital; son masas que giran y giran, aparentemente sin finalidad conocida. En cambio, en nuestro planeta una buena parte de su masa adquirió vida, lo que llamamos biomasa, que abarca todos los organismos vivos, tanto vegetales como animales, en una proporción tal que si se pudiera calcular su peso nos daría cifras astronómicas.

Sobre el futuro de nuestro sol los científicos predicen que en los próximos 1.100 millones de años aumentará su luminosidad en un 10%. Esto sobre calentará a la Tierra como consecuencia de un severo efecto de invernadero. El agua de los mares y océanos hervirá y la vida en el planeta se extinguirá.

El universo está constituido por energía y materia, que pueden transformarse la una en la otra. La energía se presenta en varias fases, entre ellas, en la energía eléctrica, la luz y el calor, cuya naturaleza íntima nos es tan desconocida. La materia también está en varios estados: sólido, líquido, gaseoso, iónico, molecular y coloidal.

En el presente estudio intento hacer algunas observaciones sobre otro estado de la materia, que he denominado estado vital, nombre que propongo para reemplazar el de materia viva, que se usa habitualmente. Par hacerlo me baso en una consideración elemental: los átomos que integran la biomasa terrestre son los mismos que constituyen la materia inerte, no están vivos. En

Summary of EPRI projects for improving power plant maintenance and maintainability

International Nuclear Information System (INIS)

Shugars, H.G.; Poole, D.N.; Pack, R.W.

1979-01-01

The Electric Power Research Institute is sponsoring projects to improve power plant maintenance and maintainability. Areas presently being emphasized are improvements in plant design for maintainability, improvements in performing nuclear plant refuelings, and development of on-line monitoring and diagnostic systems for various plant components. The seven projects are reviewed. They are: (1) human factors review of power plant maintainability; (2) refueling outage improvement; (3) on-line monitoring and diagnostics for power plant machinery; (4) acoustic emission and vibrati1on signature analysis of fossil fuel plant components; (5) acoustic monitoring of power plant valves; (6) on-line monitoring and diagnostics for generators; and (7) detection of water induction in steam turbines. Each project contractor and the project manager are listed for reference. 8 references

The inflammatory marker suPAR after cardiac arrest

DEFF Research Database (Denmark)

Rundgren, Malin; Lyngbaek, Stig; Fisker, Helle

2015-01-01

. This pilot study aimed at investigating suPAR levels in relation to outcome after CA and mild induced hypothermia. METHODS: suPAR levels were measured at 6, 36, and 72 hours in patients treated with hypothermia after CA. suPAR levels were analyzed in relation to survival after 6 months. Receiver operating...

Eric Hobsbawm y su lectura marxista de la historia

Directory of Open Access Journals (Sweden)

Pilatowsky, Mauricio

2014-06-01

Full Text Available This paper presents a brief survey of the contributions made by the historian Eric Hobsbawm to the field of History and his Marxist stance, both in his academic work and political practice. According to the author, the circumstances in which the researchers live are determinant to their study; hence this analysis includes a review of his biography. This perspective discusses his interpretation of Marx and Marxism, his understanding of History, his militancy in the Communist Party, his Jewish identity, and how he addresses nationalism in relation to the study of capitalism.En este ensayo se presenta un breve estudio de las aportaciones del historiador Eric Hobsbawm en el campo de la historia y de sus posturas marxistas; tanto en su trabajo académico como en su práctica política. El análisis incluye una revisión de su biografía ya que según el autor los investigadores y su manera de investigar responden a las circunstancias que les toca vivir. Desde esta perspectiva se aborda su interpretación de Marx y del marxismo, su forma de entender la historia, su militancia en el Partido Comunista, su identidad judía y el tratamiento del nacionalismo en su relación con el estudio del capitalismo.

CD8+CD122+CD49dlow regulatory T cells maintain T-cell homeostasis by killing activated T cells via Fas/FasL-mediated cytotoxicity.

Science.gov (United States)

Akane, Kazuyuki; Kojima, Seiji; Mak, Tak W; Shiku, Hiroshi; Suzuki, Haruhiko

2016-03-01

The Fas/FasL (CD95/CD178) system is required for immune regulation; however, it is unclear in which cells, when, and where Fas/FasL molecules act in the immune system. We found that CD8(+)CD122(+) cells, which are mostly composed of memory T cells in comparison with naïve cells in the CD8(+)CD122(-) population, were previously shown to include cells with regulatory activity and could be separated into CD49d(low) cells and CD49d(high) cells. We established in vitro and in vivo experimental systems to evaluate the regulatory activity of CD122(+) cells. Regulatory activity was observed in CD8(+)CD122(+)CD49d(low) but not in CD8(+)CD122(+)CD49d(high) cells, indicating that the regulatory cells in the CD8(+)CD122(+) population could be narrowed down to CD49d(low) cells. CD8(+)CD122(-) cells taken from lymphoproliferation (lpr) mice were resistant to regulation by normal CD122(+) Tregs. CD122(+) Tregs taken from generalized lymphoproliferative disease (gld) mice did not regulate wild-type CD8(+)CD122(-) cells, indicating that the regulation by CD122(+) Tregs is Fas/FasL-dependent. CD122(+) Tregs taken from IL-10-deficient mice could regulate CD8(+)CD122(-) cells as equally as wild-type CD122(+) Tregs both in vitro and in vivo. MHC class I-missing T cells were not regulated by CD122(+) Tregs in vitro. CD122(+) Tregs also regulated CD4(+) cells in a Fas/FasL-dependent manner in vitro. These results suggest an essential role of Fas/FasL as a terminal effector of the CD122(+) Tregs that kill activated T cells to maintain immune homeostasis.

Alternative [SU(3]4 model of leptonic color and dark matter

Directory of Open Access Journals (Sweden)

Corey Kownacki

2018-03-01

Full Text Available The alternative [SU(3]4 model of leptonic color and dark matter is discussed. It unifies at MU∼1014 GeV and has the low-energy subgroup SU(3q×SU(2l×SU(2L×SU(2R×U(1X with (u,hR instead of (u,dR as doublets under SU(2R. It has the built-in global U(1 dark symmetry which is generalized B–L. In analogy to SU(3q quark triplets, it has SU(2l hemion doublets which have half-integral charges and are confined by SU(2l gauge bosons (stickons. In analogy to quarkonia, their vector bound states (hemionia are uniquely suited for exploration at a future e−e+ collider.

Alternative [SU(3)]4 model of leptonic color and dark matter

Science.gov (United States)

Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

2018-03-01

The alternative [ SU (3) ] 4 model of leptonic color and dark matter is discussed. It unifies at MU ∼1014 GeV and has the low-energy subgroup SU(3)q × SU(2)l × SU(2)L × SU(2)R × U(1)X with (u , h) R instead of (u , d) R as doublets under SU(2)R. It has the built-in global U (1) dark symmetry which is generalized B- L. In analogy to SU(3)q quark triplets, it has SU(2)l hemion doublets which have half-integral charges and are confined by SU(2)l gauge bosons (stickons). In analogy to quarkonia, their vector bound states (hemionia) are uniquely suited for exploration at a future e-e+ collider.

FuSuMaTech workshop

CERN Multimedia

Olofsson, Simon

2018-01-01

The goal of the FuSuMaTecH IP workshop, organised at CERN Ideaquare 19-20 April, was to educate superconductivity and magnet experts about intellectual property. About 30 participants from multiple institutes and companies worked together in this two day interactive program which was facilitated by CERN Knowledge Transfer. Great progress was made in shaping the FuSuMaTech industrial demonstrator projects as well as the R&D&I subjects.

Mambertiite, BiMo"5"+_2_._8_0O_8(OH), a new mineral from Su Seinargiu, Sardinia, Italy: occurrence, crystal structure, and relationships with gelosaite

International Nuclear Information System (INIS)

Orlandi, Paolo; Biagioni, Cristian; Pasero, Marco; Merlino, Stefano; Demartin, Francesco; Campostrini, Italo

2015-01-01

Mambertiite, BiMo"5"+_2_._8_0O_8(OH), is a new mineral identified in small vugs of quartz veins from Su Seinargiu, Sarroch, Cagliari, Sardinia, Italy. It occurs as pale yellow {001} tabular crystals, up to 1 mm in length and few μm thick, with adamantine lustre. Mambertiite is brittle, with a conchoidal fracture. It is associated with ferrimolybdite, muscovite, quartz, sardignaite, and wulfenite. Electron microprobe data (wt% - mean of 12 spot analyses) are: Mo_2O_5 59.59, Bi_2O_3 36.96, WO_3 2.03, H_2O_c_a_l_c 1.48, sum 100.06. On the basis of 9 O atoms per formula unit, the empirical formula is Bi_0_._9_9(Mo"5"+_2_._7_4W_0_._0_5)_Σ_2_._7_9O_7_._9_7(OH)_1_._0_3. Infrared spectra showed absorption bands consistent with the occurrence of OH- groups. Mambertiite is triclinic, space group P1, with a = 5.854(2), b = 9.050(3), c = 7.637(3) Aa, α = 112.85(1), β = 102.58(1), γ = 90.04(1) , V = 362.3(2) Aa"3, Z = 2. The crystal structure of mambertiite was solved and refined down to R_1 = 0.050 on the basis of 2019 observed [F_o>4σ(F_o)] reflections. It is composed by eight-fold coordinated Bi-centred polyhedra and five independent Mo-centred octahedra. Among the latter, two are completely occupied by molybdenum, whereas the remaining three are only partially occupied. Two kinds of (10 anti 1) layers occur in mambertiite, alternating along [10 anti 1]*: one is composed by Bi-centered polyhedra and the two partially occupied Mo_4 and Mo_5 sites, whereas the other is composed by the zigzag chains, running along c, formed by the fully occupied Mo_1 and Mo_2 sites, and the partially occupied Mo_3 site. Mambertiite is structurally related to gelosaite, BiMo"6"+_2O_7(OH) . H_2O; their relationships can be conveniently described through the OD theory. Mambertiite is the fourth known mineral with Bi and Mo as essential components. Its name honours the Italian mineral collector Marzio Mamberti (b. 1959) for his contribution to the knowledge of the Sardinian mineralogy. The

B-decay anomalies in Pati-Salam SU(4)

Science.gov (United States)

Barbieri, Riccardo; Tesi, Andrea

2018-03-01

Attempts to incorporate in a coherent picture the B-decay anomalies presumably observed in b→ c and b→ s semi-leptonic decays have to face the absence of signals in other related experiments, both at low and at high energies. By extending and making more precise the content of Barbieri et al. (Eur Phys J C 77(1):8, 2017), we describe one such attempt based on the Pati-Salam SU(4) group, that unifies colour and the B- L charge, in the context of a new strongly interacting sector, equally responsible for producing a pseudo-Goldstone Higgs boson.

Contraction of graded su(2) algebra

International Nuclear Information System (INIS)

Patra, M.K.; Tripathy, K.C.

1989-01-01

The Inoenu-Wigner contraction scheme is extended to Lie superalgebras. The structure and representations of extended BRS algebra are obtained from contraction of the graded su(2) algebra. From cohomological consideration, we demonstrate that the graded su(2) algebra is the only superalgebra which, on contraction, yields the full BRS algebra. (orig.)

Flipped SU(5) predicts {delta}T/T

Energy Technology Data Exchange (ETDEWEB)

Kyae, Bumseok [School of Physics, Korea Institute for Advanced Study, 207-43, Cheongnyangni-Dong, Dongdaemun-Gu, Seoul 130-722 (Korea, Republic of)]. E-mail: bkyae@kias.re.kr; Shafi, Qaisar [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)]. E-mail: shafi@bartol.udel.edu

2006-04-20

We discuss hybrid inflation in supersymmetric flipped SU(5) model such that the cosmic microwave anisotropy {delta}T/T is essentially proportional to (M/M{sub P}){sup 2}, where M denotes the symmetry breaking scale and M{sub P} (=2.4x10{sup 18} GeV) is the reduced Planck mass. The magnitude of M determined from {delta}T/T measurements can be consistent with the value inferred from the evolution of SU(3) and SU(2) gauge couplings. In other words, one could state that flipped SU(5) predicts (more precisely 'postdicts') {delta}T/T. The scalar spectral index n{sub s}=0.993+/-0.007, the scalar to tensor ratio satisfies r-bar 10{sup -6}, while dn{sub s}/dlnk-bar 4x10{sup -4}.

SU(n)c x SU(m)L x U(1)N generalizations of the standard model

International Nuclear Information System (INIS)

Pleitez, V.

1993-01-01

Generalizations of the Standard Model which are based on the gauge symmetry SU(n) c x SU(m) L x U(1) N are considered. Although the most interesting possibility occurs when n = 3, it will be considered also the cases n = 4,5, both with m = 3,4. It will also be given possible grand unification scenarios. (author). 18 refs

Evidence for SU(3) symmetry breaking from hyperon production

International Nuclear Information System (INIS)

Yang Jianjun

2002-01-01

We examine the SU(3) symmetry breaking in hyperon semileptonic decays (HSD) by considering two typical sets of quark contributions to the spin content of the octet baryons: set 1 with SU(3) flavor symmetry and set 2 with SU(3) flavor symmetry breaking in the HSD. The quark distributions of the octet baryons are calculated with a successful statistical model. Using an approximate relation between the quark fragmentation functions and the quark distributions, we predict the polarizations of the octet baryons produced in e + e - annihilation and semi-inclusive deep lepton-nucleon scattering in order to reveal the SU(3) symmetry breaking effect on the spin structure of the octet baryons. We find that the SU(3) symmetry breaking significantly affects the hyperon polarization. The available experimental data on the Λ polarization seem to favor the theoretical predictions with SU(3) symmetry breaking. We conclude that there is a possibility to get collateral evidence for SU(3) symmetry breaking from hyperon production. The theoretical errors for our predictions are discussed

Symmetry breaking in a five-dimensional SU(5) model

International Nuclear Information System (INIS)

Svetovoi, V.B.; Khariton, N.G.

1986-01-01

Two-state symmetry breaking in a SU(5) model in a space with M 4 x S 1 topology is discussed. The scalar 24-plet is a component of a five-vector and acquires a nonzero vacuum expectation value at the quantum level. The vacuum differs substantially from that of the standard SU(5) model. Its orientation in the SU(5) space and absolute magnitude are fixed uniquely. The second stage of the symmetry breaking occurs on account of a five-scalar in the fundamental representation of SU(5) by means of the Weinberg mechanism. The small mass of the scalar SU(2) doublet is not explained

The anomalous U(1)_{anom} symmetry and flavors from an SU(5) × SU(5)' GUT in Z_{12-I} orbifold compactification

Science.gov (United States)

Kim, Jihn E.; Kyae, Bumseok; Nam, Soonkeon

2017-12-01

In string compactifications, frequently the anomalous U(1) gauge symmetry appears which belongs to E_8 × E_8' of the heterotic string. This anomalous U(1) gauge boson obtains mass at the compactification scale (≈ 10^{18 } {GeV}) by absorbing one pseudoscalar (corresponding to the model-independent axion) from the second rank antisymmetric tensor field B_{MN}. Below the compactification scale a global symmetry U(1)_{anom} results whose charge Q_anom is the original gauge U(1) charge. This is the most natural global symmetry, realizing the "invisible" axion. This global symmetry U(1)_{anom} is suitable for a flavor symmetry. In the simplest compactification model with the flipped SU(5) grand unification, all the low energy parameters are calculated in terms of the vacuum expectation values of the standard model singlets.

18 CFR 8.3 - Discrimination prohibited.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Discrimination prohibited. 8.3 Section 8.3 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... LICENSED PROJECTS § 8.3 Discrimination prohibited. Every licensee maintaining recreation facilities for the...

ALFONSO ESGUERRA GÓMEZ: SU PERSONALIDAD Y SU OBRA

Directory of Open Access Journals (Sweden)

Alfonso Agusti Pastor

1982-06-01

Full Text Available

Comenzaba el año de 1928 cuando una tarde se presentó al Consejo de la Facultad de Medicina de la Universidad Nacional el Profesor Julio Aparicio para anunciar su retiro de la cátedra de Fisiología y candidatizar para ese cargo, al joven médico Dr. Alfonso Esguerra Gómez, quien lo había asesorado en París en la adquisición de un laboratorio para su
cátedra; consideraba el dimitente que no había nadie en el país tan preparado como su candidato para dar un vuelco en la enseñanza de las ciencias básicas, sacándolas de la enseñanza netamente teórica y dándole un carácter más moderno, pragmático y experimental a la docencia.

Muy afortunada fue la designación porque el novel profesor resultó que había heredado la facilidad de dicción y las dotes pedagógicas de su ilustre padre el Prof. Carlos Esguerra. Además de ello exhibió desde el primer momento un dinamismo realmente asombroso: en muy corto tiempo instaló, superando dificultades de toda índole, el laboratorio por él escogido y logró la colaboración de un grupo selecto de médicos jóvenes entre los cuales se destacaban Ramón Atalaya, Juan Pablo Llinás, Daniel Brigard Herrera, Ernesto asomo,
para no citar sino unos pocos. Allí se pusieron en práctica por la primera vez en el país vivisecciones sobre ranas para demostrar a los alumnos el hecho básicamente elemental de transmisión de la excitación eléctrica del nervio ciático a la musculatura estriada correspondiente; se inició la cirugía animal sobre perros, principalmente, familiarizando a sus discípulos con las teorías de Pavlov y verificando las pruebas respectivas, se aplicaron las corrientes eléctricas directamente sobre el cerebro descubierto, sobre las zonas motoras para observar su propagación por las neuronas hasta alcanzar la musculatura estriada y la consiguiente contracción; se inició el método gráfico con registros del pulso y
de la tensión arterial; se

Higher-genus su(N) fusion multiplicities as polytope volumes

International Nuclear Information System (INIS)

Flynn, G; Rasmussen, J; Tahic, M; Walton, M A

2002-01-01

We show how higher-genus su(N) fusion multiplicities may be computed as the discretized volumes of certain polytopes. The method is illustrated by explicit analyses of some su(3) and su(4) fusions, but applies to all higher-point and higher-genus su(N) fusions. It is based on an extension of the realm of Berenstein-Zelevinsky triangles by including so-called gluing and loop-gluing diagrams. The identification of the loop-gluing diagrams is our main new result, since they enable us to characterize higher-genus fusions in terms of polytopes. Also, the genus-2 0-point su(3) fusion multiplicity is found to be a simple binomial coefficient in the affine level

Valence bond solids for SU(n) spin chains: Exact models, spinon confinement, and the Haldane gap

International Nuclear Information System (INIS)

Greiter, Martin; Rachel, Stephan

2007-01-01

To begin with, we introduce several exact models for SU(3) spin chains: First is a translationally invariant parent Hamiltonian involving four-site interactions for the trimer chain, with a threefold degenerate ground state. We provide numerical evidence that the elementary excitations of this model transform under representation 3 of SU(3) if the original spins of the model transform under representation 3. Second is a family of parent Hamiltonians for valence bond solids of SU(3) chains with spin representations 6, 10, and 8 on each lattice site. We argue that of these three models, only the latter two exhibit spinon confinement and, hence, a Haldane gap in the excitation spectrum. We generalize some of our models to SU(n). Finally, we use the emerging rules for the construction of valence bond solid states to argue that models of antiferromagnetic chains of SU(n) spins, in general, possess a Haldane gap if the spins transform under a representation corresponding to a Young tableau consisting of a number of boxes λ which is divisible by n. If λ and n have no common divisor, the spin chain will support deconfined spinons and not exhibit a Haldane gap. If λ and n have a common divisor different from n, it will depend on the specifics of the model including the range of the interaction

On the presence of lower dimensional confinement mechanisms in 4d SU2 lattice gauge theory

International Nuclear Information System (INIS)

Hari Dass, N.D.

1983-11-01

The presence of an essentially two-dimensional confinement mechanism in 4d SU 2 gauge theory has been conjectured. The authors present an explicit realization of this conjecture valid up to β = 1.8 based on variational investigations of lattice gauge theories. (Auth.)

The mysterious SU UMa stars

International Nuclear Information System (INIS)

Charles, P.A.

1990-01-01

This paper discusses the characteristics and the source of energy of the explosive stars called cataclysmic variables (CVs), with special attention given to the SU UMa stars, which represent CVs which have disks. In SU UMa binaries, a gas stream from a cool reddish star hits an accretion disk spiraling around a white dwarf. The impact of the stream produces a bright 'hot spot' on the edge of the disk, seen only when the system is quiescent and the disk is relatively dim (during outbursts, the hot spot is swamped by the light of the disk itself). The principal source of energy and light of most CVs is the gravitational potential energy released by matter falling from the dim reddish companion onto the white dwarf. The mechanism involved in the overflow of the reddish star is believed to be magnetic braking. Simulations are presented that explain the SU UMa phenomena and which may be applicable to other high-mass-ratio interacting binaries

Density matrix renormalization group simulations of SU(N ) Heisenberg chains using standard Young tableaus: Fundamental representation and comparison with a finite-size Bethe ansatz

Science.gov (United States)

Nataf, Pierre; Mila, Frédéric

2018-04-01

We develop an efficient method to perform density matrix renormalization group simulations of the SU(N ) Heisenberg chain with open boundary conditions taking full advantage of the SU(N ) symmetry of the problem. This method is an extension of the method previously developed for exact diagonalizations and relies on a systematic use of the basis of standard Young tableaux. Concentrating on the model with the fundamental representation at each site (i.e., one particle per site in the fermionic formulation), we have benchmarked our results for the ground-state energy up to N =8 and up to 420 sites by comparing them with Bethe ansatz results on open chains, for which we have derived and solved the Bethe ansatz equations. The agreement for the ground-state energy is excellent for SU(3) (12 digits). It decreases with N , but it is still satisfactory for N =8 (six digits). Central charges c are also extracted from the entanglement entropy using the Calabrese-Cardy formula and agree with the theoretical values expected from the SU (N) 1 Wess-Zumino-Witten conformal field theories.

Vector coherent state representations of SO5 contains SU2 + SU2 contains U1 + U1 and SO5 contains U1 + U1

International Nuclear Information System (INIS)

Pan Feng

1991-01-01

VCS representations of SO 5 contains SU 2 + SU 2 contains U 1 + U 1 and SO 5 contains U 1 + U 1 are discussed. Reduced matrix elements for SO 5 contains SU 2 + SU 2 are derived. The multiplicity of a weight for SO 5 is determined by using the K-matrix technique

Twin-unified SU(5) × SU( 5)′ GUT and phenomenology

Indian Academy of Sciences (India)

Specific pattern of the GUT symmetry breaking causes new strong dynamics at ... Issues of the gauge coupling unification, generation of the charged fermion and ...... the SU(3)′ strong sector) and EW symmetry breaking, the scenario shares ...

Met receptor inhibitor SU11274 localizes in the endoplasmic reticulum.

Science.gov (United States)

Wiest, Edwin J; Smith, Heather Jensen; Hollingsworth, Michael A

2018-07-02

We discovered that SU11274, a class I c-Met inhibitor, fluoresces when excited by 488 nm laser light and showed rapid specific accumulation in distinct subcellular compartments. Given that SU11274 reduces cancer cell viability, we exploited these newly identified spectral properties to determine SU11274 intracellular distribution and accumulation in human pancreatic cancer cells. The aim of the studies reported here was to identify organelle(s) to which SU11274 is trafficked. We conclude that SU11274 rapidly and predominantly accumulates in the endoplasmic reticulum. Copyright © 2018. Published by Elsevier Inc.

Static properties of baryons in the SU(3) Skyrme model

International Nuclear Information System (INIS)

Sriram, M.S.; Mani, H.S.; Ramachandran, R.

1984-01-01

We study the SU(3) x SU(3) Skyrme model with explicit chiral- and flavor-symmetry-breaking terms. We evaluate the SU(3)-symmetric meson-baryon coupling-constant ratio α, SU(3) mass breaking in the octet and decuplet, and the ΔI = 1 part of the electromagnetic mass splitting in baryons. The theoretical numbers are in reasonable agreement with the experimental values

TIPE2, a negative regulator of innate and adaptive immunity that maintains immune homeostasis.

Science.gov (United States)

Sun, Honghong; Gong, Shunyou; Carmody, Ruaidhri J; Hilliard, Anja; Li, Li; Sun, Jing; Kong, Li; Xu, Lingyun; Hilliard, Brendan; Hu, Shimin; Shen, Hao; Yang, Xiaolu; Chen, Youhai H

2008-05-02

Immune homeostasis is essential for the normal functioning of the immune system, and its breakdown leads to fatal inflammatory diseases. We report here the identification of a member of the tumor necrosis factor-alpha-induced protein-8 (TNFAIP8) family, designated TIPE2, that is required for maintaining immune homeostasis. TIPE2 is preferentially expressed in lymphoid tissues, and its deletion in mice leads to multiorgan inflammation, splenomegaly, and premature death. TIPE2-deficient animals are hypersensitive to septic shock, and TIPE2-deficient cells are hyper-responsive to Toll-like receptor (TLR) and T cell receptor (TCR) activation. Importantly, TIPE2 binds to caspase-8 and inhibits activating protein-1 and nuclear factor-kappaB activation while promoting Fas-induced apoptosis. Inhibiting caspase-8 significantly blocks the hyper-responsiveness of TIPE2-deficient cells. These results establish that TIPE2 is an essential negative regulator of TLR and TCR function, and its selective expression in the immune system prevents hyperresponsiveness and maintains immune homeostasis.

On the algebraic realization of SU(4) symmetry

International Nuclear Information System (INIS)

Asatryan, G.M.; Zaslavsky, A.N.

1976-01-01

A possibility of nonlinear realization of the symmetry with linearization on the SU(4)xYxC group is discussed. Algebraic properties of SU(4) are restored from the Weinberg condition: amplitudes of goldstone scattering on particles should have a reasonable (as in the Regge theory) asymptotic behaviour. In this case the breaking appears to be minimal. Large values of psi meson masses lead to high-lying charmed trajectories in the SU(4) algebraic realization

Phase structure of the SU(5) Coleman-Weinberg theory

International Nuclear Information System (INIS)

Tkachev, I.I.

1984-01-01

The phase structure of the SU(5) Coleman-Weinberg theory in the one-loop approximation is obtained with account of temperature and space-time curvature. We show that the most essential contribution is that from the interaction between 5 and 24 scalar fields which reflects the existence of two strongly different mass scales in the model. A stability boundary of the SU(3) x SU(2) x U(1) phase is found. It is shown that the SU(4) x U(1) phase in the Coleman-Weinberg theory is unstable. (orig.)

Lack of association between KCNJ11 (rs5219 and ABCC8 (rs757110 polymorphisms and sulphonylurea treatment response in type 2 diabetes patients in Novosibirsk region

Directory of Open Access Journals (Sweden)

Irina Arkad'evna Bondar

2015-03-01

Full Text Available Aim. Sulfonylureas (SU are widely used in everyday clinical practice in treatment of patients with type 2 diabetes mellitus (T2DM. There is a considerable variability in SU effects, which may be caused by psychological, social, biological and genetic factors. The aim of the study was to investigate the association between rs5219 KCNJ11 gene and rs757110 ABCC8 gene polymorphism and long-term response to SU-drugs of second and third generation in the Novosibirsk region. Materials and Methods. 326 patients with type 2 diabetes in the Novosibirsk region were examined. Patients were divided into 2 groups, depending on HbA1c level. The first group included patients with target HbA1c levels on SU monotherapy. The second group included patients who did not reach target HbA1c levels on the highest dose of SU. Genotyping of KCNJ11 (rs5219 and ABCC8 (rs757110 was performed by TaqMan real-time PCR (ICBFM SB RAS, Novosibirsk, Russia. Results. Patients with type 2 diabetes with a good response to SU-therapy compared to the group of patients with a poor response to SU-therapy were older (65.8?9.1 years vs. 61.6?7.9 years, p

Infinite statistics and the SU(1, 1) phase operator

International Nuclear Information System (INIS)

Gerry, Christopher C

2005-01-01

A few years ago, Agarwal (1991 Phys. Rev. A 44 8398) showed that the Susskind-Glogower phase operators, expressible in terms of Bose operators, provide a realization of the algebra for particles obeying infinite statistics. In this paper we show that the SU(1, 1) phase operators, constructed in terms of the elements of the su(1, 1) Lie algebra, also provide a realization of the algebra for infinite statistics. There are many realizations of the su(1, 1) algebra in terms of single or multimode bose operators, three of which are discussed along with their corresponding phase states. The Susskind-Glogower phase operator is a special case of the SU(1, 1) phase operator associated with the Holstein-Primakoff realization of su(1, 1). (letter to the editor)

Semblanza y liderazgo de Omar Dengo: vigencia de su pensamiento

Directory of Open Access Journals (Sweden)

Magdalena Alfaro-Rodríguez

2009-06-01

Full Text Available Recibido 29 de noviembre de 2007 • Aprobado 17 de junio de 2008 • Corregido 5 de mayo de 2009   Aspectos de la vida de Omar Dengo delinean su obra y lo definen como figura de connotado liderazgo humanista. Su quehacer docente y compromiso social se reflejan en su acción civilista que trasciende su época y aún hoy es vigente.

Radiochemical studies relevant to the production of sup 8 sup 6 Y and sup 8 sup 8 Y at a small-sized cyclotron

CERN Document Server

Kettern, K; Spellerberg, S; Coenen, H H; Qaim, S M

2002-01-01

Excitation functions were measured by the stacked-foil technique for sup n sup a sup t Sr(p,xn) sup 8 sup 8 sup , sup 8 sup 7 sup m sup , sup g Y reactions from threshold up to 25 MeV. From the measured cross sections integral yields of sup 8 sup 8 Y, sup 8 sup 7 mY and sup 8 sup 7 sup g Y were calculated. The optimum energy range for the production of sup 8 sup 8 Y is Ep=14->9 MeV; the sup 8 sup 8 Y yield amounts to 1.75 MBq (47.3 mu Ci/mu A.h) and the sup 8 sup 7 Y and sup 8 sup 7 sup m Y impurities to 2.0 and 4.4%, respectively. The isomeric cross section ratio for the pair sup 8 sup 7 sup m sup , sup g Y was determined as a function of incident proton energy and the results are discussed in terms of the spins of the two isomeric states involved. Medium scale production of both sup 8 sup 6 Y and sup 8 sup 8 Y has been carried out more than 15 times each using the (p,n) reaction. In the former case 96.3% enriched sup 8 sup 6 SrCO sub 3 was used as target material, and in the latter sup n sup a sup t SrCO su...

Citizens Science for Sustainability (SuScit) Project Briefing

DEFF Research Database (Denmark)

Eames, Malcolm; Mortensen, Jonas Egmose; Adebowale, Maria

This project briefing gives a short overview of the Citizens Science for Sustainability (SuScit) Project.......This project briefing gives a short overview of the Citizens Science for Sustainability (SuScit) Project....

The string tension and the scaling behavior of SU(2) gauge theory on a random lattice

International Nuclear Information System (INIS)

Qui Zhaoming; Ren Haichang; Academia Sinica, Beijing; Wang Xiaoqun; Yang Zhixing; Zhao Enping

1987-01-01

The SU(2) gauge theory on an 8 4 random lattice has been studied by the Monte Carlo method. The string tensions have been evaluated. They display the expected scaling behavior for β = 1.2-1.3. The scale parameter Λ RAN has been determined approximately. (orig.)

Vector-like quarks and leptons, SU(5) ⊗ SU(5) grand unification, and proton decay

International Nuclear Information System (INIS)

Lee, Chang-Hun; Mohapatra, Rabindra N.

2017-01-01

SU(5) ⊗ SU(5) provides a minimal grand unification scheme for fermions and gauge forces if there are vector-like quarks and leptons in nature. We explore the gauge coupling unification in a non-supersymmetric model of this type, and study its implications for proton decay. The properties of vector-like quarks and intermediate scales that emerge from coupling unification play a central role in suppressing proton decay. We find that in this model, the familiar decay mode p→e + π 0 may have a partial lifetime within the reach of currently planned experiments.

Neutrino masses in the SU(5) x (lower case x) SU(5)' mirror symmetric model

International Nuclear Information System (INIS)

Collie, M.; Foot, R.

1998-02-01

Motivated by the atmospheric and solar neutrino anomalies, we study neutrino masses in a parity invariant SU(5) x SU(5)' grand unified model. Two distinct ways of incorporating neutrino masses into this model are envisaged. One way involves adding a gauge singlet fermion to each generation. The other way, is to extend the scalar sector. This possibility suggests that photon - mirror photon kinetic mixing is non-zero since is generated radiatively. It is argued that the kinetic mixing is such models may well be close to the experimental limit

¿Cómo determinar su riesgo empresarial?

Directory of Open Access Journals (Sweden)

Roberto Celaya Figueroa

2013-07-01

Full Text Available Las empresas cambian de manera constante, operativa o estructuralmente, sea para responder a las necesidades del mercado o para adecuarse a los cambios. Cualquier persona interesada en analizar una empresa tiene a su alcance herramientas de análisis que van desde determinar su liquidez, rentabilidad y solvencia o sus niveles de operación y los cambios que se generan en su estructura financiera; pero un análisis muy importante y difícil, por los sesgos que sus resultados pueden generar, es la determinación del riesgo inherente a la empresa, tema al que se aboca el presente trabajo

Luis de León (1527-1591 y su teoría de la justicia: aspectos principales de su doctrina

Directory of Open Access Journals (Sweden)

Sebastián Contreras

2014-04-01

Full Text Available Las investigaciones sobre Luis de León se han centrado, sobre todo, en su mística, narrativa y teoría literaria. En este trabajo, el autor intenta desarrollar los principales aspectos de su teoría jurídica. Al igual que otros grandes teólogos de la Escuela de Salamanca, también León ha estudiado el problema de la naturaleza de la ley humana y su vinculación con el derecho natural. Éste es, justamente, el tema del siguiente trabajo.

A separate SU(2) for the third family: Topflavor

International Nuclear Information System (INIS)

Muller, D.J.; Nandi, S.; Univ. of Texas, Austin, TX

1996-01-01

The authors consider the extended electroweak gauge group SU(2) 1 xSU(2) x xU(1) Y where the first and second families of fermions couple to SU(2) 1 while the third family couples to SU(2) 2 . Bounds based on precision electroweak observables and heavy gauge boson searches are placed on the new parameters of the theory. The extra gauge bosons can be as light as about a TeV and can be discovered at future colliders such as the NLC and LHC for a wide range of the parameter space. FCNC interactions are also considered

On the SU2 unit tensor

International Nuclear Information System (INIS)

Kibler, M.; Grenet, G.

1979-07-01

The SU 2 unit tensor operators tsub(k,α) are studied. In the case where the spinor point group G* coincides with U 1 , then tsub(k α) reduces up to a constant to the Wigner-Racah-Schwinger tensor operator tsub(kqα), an operator which produces an angular momentum state. One first investigates those general properties of tsub(kα) which are independent of their realization. The tsub(kα) in terms of two pairs of boson creation and annihilation operators are realized. This leads to look at the Schwinger calculus relative to one angular momentum of two coupled angular momenta. As a by-product, a procedure is given for producing recursion relationships between SU 2 Wigner coefficients. Finally, some of the properties of the Wigner and Racah operators for an arbitrary compact group and the SU 2 coupling coefficients are studied

Higgs scalar in the grand desert with observable proton lifetime in SU(5) and small neutrino masses in SO(10)

International Nuclear Information System (INIS)

Kynshi, M.L.; Parida, M.K.

1993-01-01

We find that the presence of a real scalar in the grand desert transforming as ζ(3,0,8) under SU(2) L xU(1) Y xSU(3) C ensures the agreement of the GUT predictions with the data from CERN LEP and proton lifetime (τ p ). The mass of ζ is predicted to be close to the Peccei-Quinn symmetry-breaking scale. The computation of the threshold effects in SU(5) with Higgs representations 24, 5, and 75 shows that the maximum allowed τ p for reasonable superheavy Higgs boson masses is accessible to experimental tests at low energies. The additional predictions in SO(10) are small neutrino masses compatible with solutions to the solar-neutrino problem and the dark matter of the Universe

Francisco Suárez en la vida de su tiempo y en la del nuestro. Editorial

Directory of Open Access Journals (Sweden)

Juana María Gil Ruiz

2017-09-01

Full Text Available Con la aparición de este número dedicado —como no puede ser de otro modo— a Francisco Suárez, en la vida de su tiempo y en la del nuestro, con motivo del cuarto centenario de su fallecimiento, ACFS inaugura una nueva etapa —la tercera— que pretende, además de aprovechar este homenaje, afrontar los nuevos retos planteados por la sociedad-economía del conocimiento y sus variados indicadores —formales— de medición de calidad. Es cierto que lo que marca la calidad, al menos la científica, debería sobrepasar cualquier requisito formal, pero más allá de lo que siempre debió y debe ser lo importante, el fondo, las revistas jurídicas han tenido que reinventarse para cumplir con los requerimientos de indexación exigidos por las reconocidas Bases de Datos.

An Interaction between RRP6 and SU(VAR)3-9 Targets RRP6 to Heterochromatin and Contributes to Heterochromatin Maintenance in Drosophila melanogaster

Science.gov (United States)

Eberle, Andrea B.; Jordán-Pla, Antonio; Gañez-Zapater, Antoni; Hessle, Viktoria; Silberberg, Gilad; von Euler, Anne; Silverstein, Rebecca A.; Visa, Neus

2015-01-01

RNA surveillance factors are involved in heterochromatin regulation in yeast and plants, but less is known about the possible roles of ribonucleases in the heterochromatin of animal cells. Here we show that RRP6, one of the catalytic subunits of the exosome, is necessary for silencing heterochromatic repeats in the genome of Drosophila melanogaster. We show that a fraction of RRP6 is associated with heterochromatin, and the analysis of the RRP6 interaction network revealed physical links between RRP6 and the heterochromatin factors HP1a, SU(VAR)3-9 and RPD3. Moreover, genome-wide studies of RRP6 occupancy in cells depleted of SU(VAR)3-9 demonstrated that SU(VAR)3-9 contributes to the tethering of RRP6 to a subset of heterochromatic loci. Depletion of the exosome ribonucleases RRP6 and DIS3 stabilizes heterochromatic transcripts derived from transposons and repetitive sequences, and renders the heterochromatin less compact, as shown by micrococcal nuclease and proximity-ligation assays. Such depletion also increases the amount of HP1a bound to heterochromatic transcripts. Taken together, our results suggest that SU(VAR)3-9 targets RRP6 to a subset of heterochromatic loci where RRP6 degrades chromatin-associated non-coding RNAs in a process that is necessary to maintain the packaging of the heterochromatin. PMID:26389589

Le marketing d'un pays : Label Suède

OpenAIRE

Olsson, Erik; Gustavsson, Anna

2006-01-01

Résumé L’objet de ce mémoire est d’analyser la composition du label « Suède » et si c'est possible d'utiliser les méthodes de marketing traditionnel quand un pays est commercialisé. Nous centrons l‘attention sur l’office suédois du tourisme et des voyages qui est responsable pour le marketing de la Suède comme destination touristique. Comment travaillent-ils pour commercialiser la Suède en général et particulièrement vers la France? Nous avons commencé par étudier des différentes théories du ...

Quantum SU(2|1) supersymmetric Calogero-Moser spinning systems

Science.gov (United States)

Fedoruk, Sergey; Ivanov, Evgeny; Lechtenfeld, Olaf; Sidorov, Stepan

2018-04-01

SU(2|1) supersymmetric multi-particle quantum mechanics with additional semi-dynamical spin degrees of freedom is considered. In particular, we provide an N=4 supersymmetrization of the quantum U(2) spin Calogero-Moser model, with an intrinsic mass parameter coming from the centrally-extended superalgebra \\widehat{su}(2\\Big|1) . The full system admits an SU(2|1) covariant separation into the center-of-mass sector and the quotient. We derive explicit expressions for the classical and quantum SU(2|1) generators in both sectors as well as for the total system, and we determine the relevant energy spectra, degeneracies, and the sets of physical states.

SU(2) with fundamental fermions and scalars

Science.gov (United States)

Hansen, Martin; Janowski, Tadeusz; Pica, Claudio; Toniato, Arianna

2018-03-01

We present preliminary results on the lattice simulation of an SU(2) gauge theory with two fermion flavors and one strongly interacting scalar field, all in the fundamental representation of SU(2). The motivation for this study comes from the recent proposal of "fundamental" partial compositeness models featuring strongly interacting scalar fields in addition to fermions. Here we describe the lattice setup for our study of this class of models and a first exploration of the lattice phase diagram. In particular we then investigate how the presence of a strongly coupled scalar field affects the properties of light meson resonances previously obtained for the SU(2) model. Preprint: CP3-Origins-2017-047 DNRF90

Effective SU(2) theory for the pseudogap state

Science.gov (United States)

Montiel, X.; Kloss, T.; Pépin, C.

2017-03-01

This paper exposes in a detailed manner the recent findings about the SU(2) scenario for the underdoped phase of the cuprate superconductors. The SU(2) symmetry is formulated as a rotation between the d -wave superconducting (SC) phase and a d -wave charge order. We define the operators responsible for the SU(2) rotations and we derive the nonlinear σ model associated with it. In this framework, we demonstrate that SU(2) fluctuations are massless in finite portions of the Brillouin zone corresponding to the antinodal regions (0 ,π ) and (π ,0 ). We argue that the presence of SU(2) fluctuations in the antinodal region leads to the opening of Fermi arcs around the Fermi surface and to the formation of the pseudogap. Moreover, we show that SU(2) fluctuations lead, in turn, to the emergence of a finite momentum SC order—or pair density wave (PDW)—and more importantly to a new kind of excitonic particle-hole pairs liquid, the resonant excitonic state (RES), which is made of patches of preformed particle-hole pairs with multiple momenta. When the RES liquid becomes critical, we demonstrate that electronic scattering through the critical modes leads to anomalous transport properties. This new finding can account for the strange metal (SM) phase at finite temperature, on the right-hand side of the SC dome, shedding light on another notoriously mysterious part of the phase diagram of the cuprates.

Cish actively silences TCR signaling in CD8+ T cells to maintain tumor tolerance.

Science.gov (United States)

Palmer, Douglas C; Guittard, Geoffrey C; Franco, Zulmarie; Crompton, Joseph G; Eil, Robert L; Patel, Shashank J; Ji, Yun; Van Panhuys, Nicholas; Klebanoff, Christopher A; Sukumar, Madhusudhanan; Clever, David; Chichura, Anna; Roychoudhuri, Rahul; Varma, Rajat; Wang, Ena; Gattinoni, Luca; Marincola, Francesco M; Balagopalan, Lakshmi; Samelson, Lawrence E; Restifo, Nicholas P

2015-11-16

Improving the functional avidity of effector T cells is critical in overcoming inhibitory factors within the tumor microenvironment and eliciting tumor regression. We have found that Cish, a member of the suppressor of cytokine signaling (SOCS) family, is induced by TCR stimulation in CD8(+) T cells and inhibits their functional avidity against tumors. Genetic deletion of Cish in CD8(+) T cells enhances their expansion, functional avidity, and cytokine polyfunctionality, resulting in pronounced and durable regression of established tumors. Although Cish is commonly thought to block STAT5 activation, we found that the primary molecular basis of Cish suppression is through inhibition of TCR signaling. Cish physically interacts with the TCR intermediate PLC-γ1, targeting it for proteasomal degradation after TCR stimulation. These findings establish a novel targetable interaction that regulates the functional avidity of tumor-specific CD8(+) T cells and can be manipulated to improve adoptive cancer immunotherapy.

Structural properties of the self-conjugate SU(3) tensor operators

International Nuclear Information System (INIS)

Lohe, M.A.; Biedenharn, L.C.; Louck, J.D.

1977-01-01

Denominator functions for the set of self-conjugate SU(3) tensor operators are explicitly obtained and shown to be uniquely related to SU(3) -invariant structural properties. This relationship becomes manifest through the appearance of zeroes of the denominator functions which thereby express the fundamental null space properties of SU(3) tensor operators. It is demonstrated that there exist characteristic denominator functions whose zeroes, in position and multiplicity, possess the interesting, and unexpected, property of forming SU(3) weight space patterns

SU(5) without SU(5): why B-L is conserved and baryon number not in unified models of quarks and leptons

International Nuclear Information System (INIS)

Lipkin, H.J.

1980-09-01

Quark-lepton unification is examined without assuming higher symmetries on more general gauge theories. In particular, properties are sought which are generally attributed to SU(5) models which are already present without the assumption of SU(5)

Avoiding domain wall problem in SU(N) grand unified theories

International Nuclear Information System (INIS)

Fujimoto, Y.; Zhiyong, Z.

1982-08-01

We look for the possibility of embedding the discrete sub-group of U(1)-Pecci-Quinn symmetry into the continuous one to avoid the domain wall problem. We find, within some restricted context, among various SU(N) models only one-family SU(5) and SU(6). (author)

IR fixed points in SU(3 gauge theories

Directory of Open Access Journals (Sweden)

K.-I. Ishikawa

2015-09-01

Full Text Available We propose a novel RG method to specify the location of the IR fixed point in lattice gauge theories and apply it to the SU(3 gauge theories with Nf fundamental fermions. It is based on the scaling behavior of the propagator through the RG analysis with a finite IR cutoff, which we cannot remove in the conformal field theories in sharp contrast to the confining theories. The method also enables us to estimate the anomalous mass dimension in the continuum limit at the IR fixed point. We perform the program for Nf=16,12,8 and Nf=7 and indeed identify the location of the IR fixed points in all cases.

Urine suPAR levels compared with plasma suPAR levels as predictors of post-consultation mortality risk among individuals assumed to be TB-negative: a prospective cohort study

DEFF Research Database (Denmark)

Rabna, Paulo; Andersen, Andreas; Wejse, Christian

2010-01-01

-suPAR was measured using a commercial ELISA (suPARnostic®). We found that U-suPAR carried significant prognostic information on mortality for HIV-infected subjects with an area under the ROC curve of 0.75. For HIV-negative individuals, little or no prognostic effect was observed. However, in both HIV positives...... and negatives, the predictive effect of U-suPAR was found to be inferior to that of P-suPAR....

Entanglement criteria via the uncertainty relations in su(2) and su(1,1) algebras: Detection of non-Gaussian entangled states

International Nuclear Information System (INIS)

Nha, Hyunchul; Kim, Jaewan

2006-01-01

We derive a class of inequalities, from the uncertainty relations of the su(1,1) and the su(2) algebra in conjunction with partial transposition, that must be satisfied by any separable two-mode states. These inequalities are presented in terms of the su(2) operators J x =(a † b+ab † )/2, J y =(a † b-ab † )/2i, and the total photon number a +N b >. They include as special cases the inequality derived by Hillery and Zubairy [Phys. Rev. Lett. 96, 050503 (2006)], and the one by Agarwal and Biswas [New J. Phys. 7, 211 (2005)]. In particular, optimization over the whole inequalities leads to the criterion obtained by Agarwal and Biswas. We show that this optimal criterion can detect entanglement for a broad class of non-Gaussian entangled states, i.e., the su(2) minimum-uncertainty states. Experimental schemes to test the optimal criterion are also discussed, especially the one using linear optical devices and photodetectors

Model with a gauged lepton flavor SU(2) symmetry

Science.gov (United States)

Chiang, Cheng-Wei; Tsumura, Koji

2018-05-01

We propose a model having a gauged SU(2) symmetry associated with the second and third generations of leptons, dubbed SU(2) μτ , of which U{(1)}_{L_{μ }-L_{τ }} is an Abelian subgroup. In addition to the Standard Model fields, we introduce two types of scalar fields. One exotic scalar field is an SU(2) μτ doublet and SM singlet that develops a nonzero vacuum expectation value at presumably multi-TeV scale to completely break the SU(2) μτ symmetry, rendering three massive gauge bosons. At the same time, the other exotic scalar field, carrying electroweak as well as SU(2) μτ charges, is induced to have a nonzero vacuum expectation value as well and breaks mass degeneracy between the muon and tau. We examine how the new particles in the model contribute to the muon anomalous magnetic moment in the parameter space compliant with the Michel decays of tau.

The winding number of three complexes in SU(3)

International Nuclear Information System (INIS)

Lasher, G.

1989-01-01

The Phillip-Stone algorithm for the topological charge of a lattice gauge field requires the computation of the winding number of certain 3-complexes in the space of the group. The extension of the computational procedure for the SU(2) gauge group to SU(3) requires an understanding of the SU(3) geometry. An important issue is the behavior of a 3-cell in SU(3) as it approaches a critical configuration, i.e., one at which the cell is a discontinuous function of its vertices. A measure of the proximity of a cell to criticality is found and a method for computing its contribution to the winding number is recommended. (orig.)

Three particle Poincare states and SU(6) x SU(3) as a classification group for baryons

International Nuclear Information System (INIS)

Buccella, F.; Sciarrino, A.; Sorba, P.

1975-05-01

A complete set of democratic quantum numbers is introduced to classify the states of an irreducible unitary representation (IUR) of the Poincare group obtained from the decomposition of the direct products of three I.U.R. Such states are identified with the baryon states constituted of three free relativistic quarks. The transformation from current to constituent quarks is then easily reobtained. Moreover, the group SU(6) x SU(3) appears naturally as a collinear classification group for baryons. Results similar to those of the symmetric harmonic oscillator quark model are obtained [fr

White dwarf axions, PAMELA data, and flipped-SU(5)

Energy Technology Data Exchange (ETDEWEB)

Bae, Kyu Jung [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Huh, Ji-Haeng [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: jhhuh@phya.snu.ac.kr; Kim, Jihn E. [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: jekim@ctp.snu.ac.kr; Kyae, Bumseok [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: bskyae@gmail.com; Viollier, Raoul D. [Institute of Theoretical Physics and Astrophysics, Department of Physics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa)

2009-08-11

Recently, there are two hints arising from physics beyond the standard model. One is a possible energy loss mechanism due to emission of very weakly interacting light particles from white dwarf stars, with a coupling strength {approx}0.7x10{sup -13}, and another is the high energy positrons observed by the PAMELA satellite experiment. We construct a supersymmetric flipped-SU(5) model, SU(5)xU(1){sub X} with appropriate additional symmetries, [U(1){sub H}]{sub gauge}x[U(1){sub R}xU(1){sub {gamma}}]{sub global}xZ{sub 2}, such that these are explained by a very light electrophilic axion of mass 0.5 meV from the spontaneously broken U(1){sub {gamma}} and two component cold dark matters from Z{sub 2} parity. We show that in the flipped-SU(5) there exists a basic mechanism for allowing excess positrons through the charged SU(5) singlet leptons, but not allowing antiproton excess due to the absence of the SU(5) singlet quarks. We show the discovery potential of the charged SU(5) singlet E at the LHC experiments by observing the electron and positron spectrum. With these symmetries, we also comment on the mass hierarchy between the top and bottom quarks.

Vitoria y Suárez: el Derecho Internacional

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Adolfo J. Sánchez Hidalgo

2017-09-01

Full Text Available Este artículo pretende mostrar la convivencia de dos estructuras de pensamiento en la escolástica española y, especialmente, en Suárez. Vitoria presenta una visión comunitaria del orden internacional y sus enseñanzas serán transmitidas a Suárez, quien, al contrario, presenta una visión societaria del orden internacional. Esta diferencia no es una casualidad, sino un auténtico cambio de paradigma en el sabio granadino, que hace de él un autor más próximo a la modernidad que a la tradición escolástica. Gracias a un estudio comparado mostraremos el punto de inflexión que supone Suárez en el tránsito hacia la modernidad y su idea de un orden mundial fundado en una sociedad de Estados.

Meson-baryon four-body reaction amplitudes in exact SU(4)

International Nuclear Information System (INIS)

Liede, I.; Maalampi, J.; Roos, M.

1976-01-01

Fully SU(4) symmetric meson-baryon four body reaction amplitudes are presented in terms of SU(4) eigenamplitudes. The mesons and baryons considered belong to the SU(4) representations 15 and 20, respectively. Using these reletions, the cross-sections for the production of charmed particles can be predicted from known uncharmed reactions. (author)

Flipped SU(6) from ten dimensions

Energy Technology Data Exchange (ETDEWEB)

Panagiotakopoulos, C. (Bartol Research Inst., Univ. of Delaware, Newark, DE (US))

1990-06-20

The authors study the compactification of the heterotic supersting on the only known three generation Calabi-Yau space with flux breakings leading to SU(6) {times} U(1) as the gauge group in four dimensions. We compute the massless spectrum and identify the discrete symmetries of the internal space that survive flux breaking. The possible four-dimensional models are classified according to their honest discrete symmetries. The allowed breaking chains of SU(6) {times} U(1) are listed. Model building with SU(6) {times} U(1) is discussed in general and a concrete realistic model is constructed which does not suffer from the gauge hierarchy problem, fast proton decay or any other obvious phenomenological disaster. A distinct experimental signature of this class of models is the presence in the low energy spectrum of vector-like quarks and antiquarks, outside the three known families, with masses of the order of the supersymmetry breaking scale.

"QUERIDÍSIMA FRIEDUCHA"!... CARTAS DE GUILLERMO KAHLO A SU HIJA FRIDA

Directory of Open Access Journals (Sweden)

Annette B. Ramírez de Arellano

2010-01-01

Full Text Available Entre 1932 y 1933, Guillermo Kahlo escribió una docena de cartas extensas a su hija Frida, quien se encontraba en Estados Unidos en compañía de su esposo Diego Rivera. Estas cartas revelan un padre afectuoso, preocupado por el bienestar de su hija y empeñado en aconsejarle contra algunas de las "fallas" del temperamento que ambos compartían. También muestran el luto y la soledad que embargaban a Guillermo luego de la muerte de su esposa, la madre de Frida, y los intentos de la hija por buscarle distracciones y actividades. Las misivas también revelan el sentido del humor de Guillermo y su tendencia a lanzar dardos epistolares cuando quería recalcar su punto de vista.

More flipped SU(5) x U(1) baryosynthesis

Energy Technology Data Exchange (ETDEWEB)

Ellis, J.; Hagelin, J.S.; Nanopoulos, D.V.; Olive, K.A.

1988-06-30

We supplement a previous discussion of baryosynthesis in flipped SU(5)xU(1) GUTs by including (1) the large incoherent field energy density which is likely when SU(5) is broken, and (2) the possibility of additional Higgs triplet fields suggested by four-dimensional string model-building. We consider strong (weak) reheating scenarios in which the Universe is (is not) SU(5) symmetric after inflation. We find an adequate baryon asymmetry subsequent to strong reheating, whatever the number of Higgs triplets (although beware of possible difficulties with quasi-stable relic particles), whereas weak reheating requires at least two Higgs triplets.

SU (N) lattice integrable models and modular invariance

International Nuclear Information System (INIS)

Zuber, J.B.; Di Francesco, P.

1989-01-01

We first review some recent work on the construction of RSOS SU (N) critical integrable models. The models may be regarded as associated with a graph, extending from SU (2) to SU (N) an idea of Pasquier, or alternatively, with a representation of the fusion algebra over non-negative integer valued matrices. Some consistency conditions that the Boltzmann weights of these models must satisfy are then pointed out. Finally, the algebraic connections between (a subclass of) the admissible graphs and (a subclass of) modular invariants are discussed, based on the theory of C-algebras. The case of G 2 is also treated

Vaccine profile of herpes zoster (HZ/su) subunit vaccine.

Science.gov (United States)

Cunningham, Anthony L; Heineman, Thomas

2017-07-01

Herpes zoster (HZ) causes an often severe and painful rash in older people and may be complicated by prolonged pain (postherpetic neuralgia; PHN) and by dissemination in immune-compromised patients. HZ results from reactivation of latent varicella-zoster virus (VZV) infection, often associated with age-related or other causes of decreased T cell immunity. A live attenuated vaccine boosts this immunity and provides partial protection against HZ, but this decreases with age and declines over 8 years. Areas covered: A new HZ subunit (HZ/su) vaccine combines a key surface VZV glycoprotein (E) with a T cell-boosting adjuvant system (AS01 B ) and is administered by two intramuscular injections two months apart. Expert commentary: HZ/su showed excellent efficacy of ~90% in immunocompetent adults ≥50 and ≥70 years of age, respectively, in the ZOE-50 and ZOE-70 phase III controlled trials. Efficacy was unaffected by advancing age and persisted for >3 years. Approximately 9.5% of subjects had severe, but transient (1-2 days) injection site pain, swelling or redness. Compliance with both vaccine doses was high (95%). The vaccine will have a major impact on HZ management. Phase I-II trials showed safety and immunogenicity in severely immunocompromised patients. Phase III trial results are expected soon.

Tipos de tirano y resistencia en Francisco Suárez

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Pablo Font Oporto

2017-09-01

Full Text Available El presente artículo pretende analizar la discusión que Francisco Suárez mantiene con las tesis contrarias a la distinción entre tipos de tirano en la cuestión del tiranicidio (Defensio fidei, Libro VI, capítulo IV, números 10-13. Para esta visión no le es lícito a una persona privada matar a ninguno de los dos tipos de tirano; sólo es posible darles muerte en legítima defensa, porque se entiende que en tal caso se actúa en ejercicio de autoridad pública. Suárez acaba admitiendo esta tesis en el número 13, lo que parece contradecirse con lo sostenido en el número 7, donde se aceptaba la muerte del usurpador por cualquier particular. Sin embargo, en el fondo mantiene la diferencia entre ambos tipos de tirano, por cuanto que en el caso del usurpador sostiene que siempre se dan las condiciones para alegar legítima defensa. Queda sin aclarar qué ocurre en tal caso con las condiciones dispuestas en los números 8 y 9.

Estado Vital de la Materia. Su origen, su evolución y su futuro.

OpenAIRE

J. Hernando Ordoñez

2001-01-01

En este artlculo se hacen algunas observaciones sobre un estado de la materia (estado vital), propuesto para reemplazar el de materia viva, que se usa habitualmente.

La materia en estado vital se organiza por una fuerza interna, que podríamos calificar como inteligente, que hace que los átomos se orienten y se organicen con determinada finalidad para fabricar células, para modelar órganos y, éstos, para culminar su obra integrándose con la armonía más admirable, par...

Operating philosophy for maintaining occupational radiation exposures as low as is reasonably achievable

International Nuclear Information System (INIS)

1975-09-01

Both this guide and Regulatory Guide 8.8, ''Information Relevant to Maintaining Occupational Radiation Exposure as Low as is Reasonably Achievable (Nuclear Power Reactors),'' deal with the concept of ''as low as is reasonably achievable'' occupational exposures to radiation. This guide describes an operating philosophy that the NRC staff believes all specific licensees should follow to keep occupational exposures to radiation as low as is reasonably achievable. (auth)

Soluble urokinase plasminogen activator receptor (suPAR) in acute care

DEFF Research Database (Denmark)

Rasmussen, Line Jee Hartmann; Ladelund, Steen; Haupt, Thomas Huneck

2016-01-01

for age, sex, Charlson score and C reactive protein. Area under the curve for receiver operating characteristics curve analysis of suPAR for 30-day mortality was 0.84 (95% CI 0.81 to 0.86). Furthermore, in the entire cohort, women had slightly higher suPAR compared with men, and suPAR was associated...

Constructability and maintainability

International Nuclear Information System (INIS)

Hart, R.S.

1985-01-01

A set of principles for minimizing the construction schedule was established at the outset of the CANDU 300 programme. Consideration of these principles and other factors led to the development of the unique CANDU 300 station layout. The paper discusses the CANDU 300 station layout and construction methods. In summary, the station layout provides 360 deg. construction access to all buildings, separation of nuclear and non-nuclear systems, precise and minimal physical interfaces between buildings, accommodation of many contractors and construction activities without interference, and maximum flexibility in terms of constructional, financial and supply arrangements. The CANDU 300 further employs modularization, shop fabrication and advanced instrumentation (multiplexers, remote processors, data highways) to minimize construction time. Many of the CANDU 300 features that enhance constructability also contribute to maintainability. These include the 360 deg. access to all principal buildings, the uncluttered and spacious building layouts, the simplification of systems and the high level of modularization. The CANDU 300 has also been designed to facilitate the replacement of all key components, thereby offering an essentially unlimited station life. A prime example is a reduction in the fuel channel inlet end-fitting diameter such that the fuel channels can be shop assembled and easily replaced after the initial 40 years of operation, without an extended unit outage. Maintainability within the reactor building has been given particular attention in the CANDU 300 design; key features of other CANDU reactors (the ability to replace a heat transport system pump motor at power, for example) have been incorporated, while accessibility and maintainability of all systems and components have been enhanced. These and other aspects of maintainability are discussed. (author)

La poesía ebanita y su precursor Candelario Obeso

Directory of Open Access Journals (Sweden)

Ramiro Lagos

1983-01-01

Full Text Available Colombia, crisol de un claro mestizaje acriollado, donde la raza se funda, no en el color sino en el bronce de su valor y de su épica, unido a esa patina de cultura que da al colombiano un perfil singular, es quizá una de las naciones que más se han liberado, por su cultura, de las consabidas discriminaciones que separan al blanco del negro, del mulato y del aindiado. No es Colombia un país estrictamente criollo como las naciones rioplatenses que se precian de su ancestro europeo. Sin embargo, tan criollo culturalmente, se enorgullece de serlo el colombiano como aquel que lo es por dictados de la sangre ancestral, considerándose Colombia uno de los países más hispánicos, no sólo por la sangre cultural que colma su espíritu neorenacentista, sino por el purismo de su lenguaje castizo con que se expresan, para hablar con énfasis y claridad, las voces múltiples de sus portavoces raciales.

SO(8) fermion dynamical symmetry and strongly correlated quantum Hall states in monolayer graphene

Science.gov (United States)

Wu, Lian-Ao; Murphy, Matthew; Guidry, Mike

2017-03-01

A formalism is presented for treating strongly correlated graphene quantum Hall states in terms of an SO(8) fermion dynamical symmetry that includes pairing as well as particle-hole generators. The graphene SO(8) algebra is isomorphic to an SO(8) algebra that has found broad application in nuclear physics, albeit with physically very different generators, and exhibits a strong formal similarity to SU(4) symmetries that have been proposed to describe high-temperature superconductors. The well-known SU(4) symmetry of quantum Hall ferromagnetism for single-layer graphene is recovered as one subgroup of SO(8), but the dynamical symmetry structure associated with the full set of SO(8) subgroup chains extends quantum Hall ferromagnetism and allows analytical many-body solutions for a rich set of collective states exhibiting spontaneously broken symmetry that may be important for the low-energy physics of graphene in strong magnetic fields. The SO(8) symmetry permits a natural definition of generalized coherent states that correspond to symmetry-constrained Hartree-Fock-Bogoliubov solutions, or equivalently a microscopically derived Ginzburg-Landau formalism, exhibiting the interplay between competing spontaneously broken symmetries in determining the ground state.

Violencia contra la mujer infligida por su pareja y su relación con la salud mental de los hijos adolescentes

OpenAIRE

Vargas Murga, Horacio

2017-01-01

Se presenta una revisión de la literatura científica nacional e internacional, así como de documentos técnicos, sobre la violencia contra la mujer infligida por su pareja y su relación con la salud mental de los hijos adolescentes. Se abordan aspectos generales a manera de introducción y luego se muestra información sobre la epidemiología de la violencia contra la mujer, la violencia contra la mujer infligida por su pareja, los efectos de la violencia contra la mujer, los efectos sobre la sal...

La actitud del vendedor ante las innovaciones tecnológicas y su influencia en su desempeño en las ventas

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José Fernando Barahona Vinasco

2017-09-01

Full Text Available El objetivo de este trabajo es determinar cómo la actitud que tienen los vendedores ante la tecnología puede representar un factor decisivo en la implementación de los procesos de automatización de la fuerza de ventas (afv. Se parte del modelo de aceptación tecnológica (tam, por su sigla en inglés, que asume que la actitud viene determinada por la utilidad percibida y por la facilidad de uso de esta, e introducimos como novedad en el modelo su relación con el desempeño. Se contrasta el modelo conceptual en una muestra de vendedores colombianos a través de un modelo de ecuaciones estructurales. Los resultados establecen que la percepción de la facilidad de uso de la tecnología influye positivamente en su utilidad percibida, al igual que la percepción de facilidad de uso influye positivamente en la actitud hacia su uso. Sin embargo, la utilidad percibida de la tecnología no muestra una relación directa frente a la actitud hacia su uso, y de igual forma no existe relación directa entre la actitud hacia el uso y el desempeño en ventas.

Nuevos dibujos de Alonso Cano y su círculo

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Navarrete Prieto, Benito

2001-12-01

Full Text Available No es fácil abordar el estudio de los dibujos de Alonso Cano. Su versatilidad, su dominio y aplicación en las diferentes técnicas y sobre todo las obras de su círculo más inmediato y de seguidores y copistas dificultan en grado extremo la catalogación correcta de sus diseños, algo imprescindible para poder conocer en profundidad la obra y el alcance de la pintura del artista granadino, así como su forma de trabajo, que ejemplifica sin lugar a dudas las preocupaciones de un hombre culto, formado en un ambiente intelectual y erudito y sobre todo con un bagaje cultural amplio según se deduce de su biblioteca comprada por Vicente Salvador Gómez en 1673 y que se publica en este mismo número de Archivo.…

La valoración que los graduados tienen sobre su formación universitaria desde su situación laboral actual

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Albert SANCHEZ-GELABERT

2016-05-01

Full Text Available En este artículo analizamos la valoración de los titulados universitarios sobre la formación recibida y su utilidad en la ocupación actual. El objetivo es analizar si existen diferencias por el nivel formativo de origen y el sexo de los estudiantes. A su vez, examinamos si las características de la situación laboral intervienen en estas relaciones afectando diferencialmente según las características sociodemográficas. Los resultados muestran la existencia de diferencias valorativas entre los jóvenes según su origen social y sexo, siendo las mujeres y los jóvenes de clase trabajadora los que valoran mejor su formación recibida. Finalmente, con la introducción de la situación laboral como variable de control constatamos que, en algunos casos, estas diferencias valorativas son debidas al contexto laboral actual de los graduados más que a diferencias sociodemográficas.

El inmueble: significantes de su valor

OpenAIRE

Ferrando Corell, José Vicente; Ferrando Ortiz, Juan; Ferrando Ortiz, Adela

2017-01-01

En los análisis que se realizan sobre materia de valoración inmobiliaria, es habitual abordar su tratamiento señalando una pretendida cantidad monetaria que lo represente.Sin embargo, para que ello sea posible, se debería previamente señalar y estudiar los fundamentos que le dotan de valor. Es decir, la cualidad o cualidades que singularizan a un bien frente a otros; aquellas por las que se le reconoce su valor.Ya conocemos que las cualidades de valor tanto pueden ser tangibles como intangibl...

Brianchón y su Teorema

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José Manuel Sánchez Muñoz

2011-05-01

Full Text Available Este artículo versa sobre las investigaciones de un joven Charles Julien Brianchón cuando sólo contaba con 21 años y estaba aún en su época de estudiante del École Polytechnique de París. Estos resultados sirvieron para poner de manifiesto uno de los pilares fundamentales de la cada vez más importante Geometría Proyectiva, el Principio de Dualidad y su relación con el Teorema de Pascal sobre cónicas demostrado 167 años antes.

Factoriality of representations of the group of paths on SU(n)

International Nuclear Information System (INIS)

Albeverio, S.

We prove factoriality in the cyclic component of the vacuum for the energy representation of SU(n)-valued paths groups. The main tool is a lemma concerning generic pairs of Cartan subalgebras in the Lie algebra su(n) of SU(n) groups. (orig.)

Hyperon resonances in SU(3) soliton models

International Nuclear Information System (INIS)

Scoccola, N.N.

1990-01-01

Hyperon resonances excited in kaon-nucleon scattering are investigated in the framework of an SU(3) soliton model in which kaon degrees of freedom are treated as small fluctuations around an SU(2) soliton. For partial waves l≥2 the model predicts correctly the quantum numbers and average excitation energies of most of the experimentally observed Λ and Σ resonances. Some disagreements are found for lower partial waves. (orig.)

A unified model of the strong and electroweak interactions based on the gauge group SU(18)L x SU(18)R

International Nuclear Information System (INIS)

Kim Il Kang

1986-01-01

On the basis of semi-simple gauge group G=SU(18) L x SU(18) R the unified theory of strong, weak and electromagnetic fields is constructed, and it is shown that the Weinberg angle and the energy of unification are in good agreement with the experimental values. (author)

Random SU(2) invariant tensors

Science.gov (United States)

Li, Youning; Han, Muxin; Ruan, Dong; Zeng, Bei

2018-04-01

SU(2) invariant tensors are states in the (local) SU(2) tensor product representation but invariant under the global group action. They are of importance in the study of loop quantum gravity. A random tensor is an ensemble of tensor states. An average over the ensemble is carried out when computing any physical quantities. The random tensor exhibits a phenomenon known as ‘concentration of measure’, which states that for any bipartition the average value of entanglement entropy of its reduced density matrix is asymptotically the maximal possible as the local dimensions go to infinity. We show that this phenomenon is also true when the average is over the SU(2) invariant subspace instead of the entire space for rank-n tensors in general. It is shown in our earlier work Li et al (2017 New J. Phys. 19 063029) that the subleading correction of the entanglement entropy has a mild logarithmic divergence when n  =  4. In this paper, we show that for n  >  4 the subleading correction is not divergent but a finite number. In some special situation, the number could be even smaller than 1/2, which is the subleading correction of random state over the entire Hilbert space of tensors.

Patrick Suskind: Su narrativa

Directory of Open Access Journals (Sweden)

Melba Cecilia Serrano G.

1988-04-01

Full Text Available RESUMEN  En este artículo muestra el éxito que tuvo este autor frente a las diferentes obras que ha escrito. No obstante se destaca su obra llamado “perfume”, que lo hace muy representativo de este autor.

Maintaining Healthy Skin -- Part 2

Science.gov (United States)

... and SCI • Depression and SCI • Taking Care of Pressure Sores • Maintaining Healthy Skin (Part I) • Maintaining Healthy Skin ( ... For information on establishing skin tolerance, see our “Pressure Sores” pamphlet.) Pressure releases in a wheelchair can be ...

5 CFR 1604.8 - Death benefits.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Death benefits. 1604.8 Section 1604.8... benefits. The account balance of a deceased service member will be paid as described at 5 CFR part 1651... benefit, a service member must file a valid beneficiary designation form. If the TSP maintains a service...

Quantum critical spin-2 chain with emergent SU(3) symmetry.

Science.gov (United States)

Chen, Pochung; Xue, Zhi-Long; McCulloch, I P; Chung, Ming-Chiang; Huang, Chao-Chun; Yip, S-K

2015-04-10

We study the quantum critical phase of an SU(2) symmetric spin-2 chain obtained from spin-2 bosons in a one-dimensional lattice. We obtain the scaling of the finite-size energies and entanglement entropy by exact diagonalization and density-matrix renormalization group methods. From the numerical results of the energy spectra, central charge, and scaling dimension we identify the conformal field theory describing the whole critical phase to be the SU(3)_{1} Wess-Zumino-Witten model. We find that, while the Hamiltonian is only SU(2) invariant, in this critical phase there is an emergent SU(3) symmetry in the thermodynamic limit.

suPAR

DEFF Research Database (Denmark)

Eugen-Olsen, Jesper; Giamarellos-Bourboulis, Evangelos J

2015-01-01

Investigation of biomarkers that can promptly predict unfavourable outcome of critically illness is an emerging necessity taking into consideration the need for early intervention, the shortage of available beds in intensive care units and the considerable cost of hospitalisation. The most...... promising biomarker is soluble urokinase-type plasminogen activator receptor (suPAR). Three studies in large populations of critically ill patients and patients admitted to the emergency department have shown that concentrations >12ng/mL can safely predict unfavourable outcome. This review presents...

La potestad tributaria en Francisco Suárez

Directory of Open Access Journals (Sweden)

Luis Carlos Amezúa Amezúa

2017-09-01

Full Text Available Francisco Suárez es el teólogo más relevante de la escuela española de derecho natural o Escuela de Salamanca en sentido amplio. Según piensa, el derecho de imponer tributos justos reside en exclusiva en la autoridad suprema, sin necesitar el consentimiento de las Cortes. El Estado tiene ese poder de establecer leyes tributarias para asegurar la paz, el orden y el buen gobierno de la comunidad. Es el poder más importante entre todas las facultades propias de la soberanía, pero debe respetar las exigencias de un impuesto justo: además de la autoridad legítima, una causa justa y distribución proporcional. En este artículo, desarrollaremos la doctrina de Suárez, su interpretación acerca de la duda probable sobre la injusticia del impuesto, y su aceptación de los impuestos sobre el consumo. Todos estos razonamientos iban dirigidos a fortalecer al gobernante, que debe actuar dentro de un marco ético respetuoso con el bien común.

Idea and application of spectrum-generating SU(3) and SU(4)

International Nuclear Information System (INIS)

Bohm, A.; Teese, R.B.

1978-10-01

The basic ideas of the spectrum-generating SU(n) approach in particle physics are reviewed and the analogy is shown between this and the spectrum-generating method in atomic and molecular physics. The tests of this framework involving one-hadron processes are outlined and two tests of a fundamental relation of this framework (the Werle relation) are discussed. 32 references

Evaluation of physical constants and operators in the SU(2) and SU(3) lattice gauge theory

International Nuclear Information System (INIS)

Tsuchida, R.H.

1987-01-01

Wilson loops and Wilson lines in the fundamental and the adjoint representations of SU(2) on the lattice are measured using the icosahedral subgroup and a noise reduction technique. The string tension was evaluated by fitting the expectation value of loops of all sizes to a 6-parameter curve. From the Wilson lines in the adjoint representation of SU(2), two kinds of gluon potentials were measured: the gluon-gluon interaction potential and the gluon-image interaction potential. The effective mass of the gluon was evaluated on each of those potentials and compared. In SU(3), the contribution of s anti σ/sub μnu/F/sub μnu/d operator to the correction of effective weak four-quark operator in the measurement of ΔI = 1/2 amplitude of kaon decay is examined. The renormalization of the critical hopping parameter is calculated perturbatively and compared with the Monte Carlo results. The VEV of psi anti psi operator is measured on the lattice. In the hopping parameter renormalization calculation and the psi anti psi measurements, the effects of expanding of Feynman diagrams in power of a, the lattice spacing, are examined

Gradient flow coupling in the SU(2) gauge theory with two adjoint fermions

DEFF Research Database (Denmark)

Rantaharju, Jarno

2016-01-01

We study SU(2) gauge theory with two fermion flavors in the adjoint representation. Using a clover improved HEX smeared action and the gradient flow running coupling allows us to simulate with larger lattice size than before. We find an infrared fixed point after a continuum extrapolation in the ...... in the range 4.3g∗24.8. We also measure the mass anomalous dimension and find the value 0.25γ∗0.28 at the fixed point....

SU(5)c color model constraints from UA2

International Nuclear Information System (INIS)

Foot, R.; Hernandez, O.F.; Rizzo, T.G.; Ames Lab., IA; Iowa State Univ. of Science and Technology, Ames

1991-01-01

We investigate the possibility that the color gauge group SU(3) may arise as a consequence of the spontaneous symmetry breaking of SU(5) c . In an earlier paper we examine the constraints imposed on the SU(5) c color model by recent measurements of the dijet mass distribution at CDF. We found that the CDF data did not exclude any region of parameter space in the model. Here we consider similar data from UA2 and find that it leads to the constraint Msub(Z') > or approx. 280 GeV. (orig.)

On the topological structure of the vacuum in SU(2) and SU(3) lattice gauge theories

International Nuclear Information System (INIS)

Ishikawa, K.; Schierholz, G.; Schneider, H.; Teper, M.

1983-01-01

We present Monte Carlo measurements of the net topological charge of the vacuum in SU(2) and SU(3) lattice gauge theories. In both cases there is no evidence of any topological structure, and the values obtained are a factor of 0(100) smaller than expectations based on analyses of the U(1) problem. Moreover we find a strong sensitivity to the lattice size and to the boundary conditions imposed on the lattice. We comment on the physical significance of these results, establish criteria for the reliable performance of such calculations, and remark on the possibly detrimental impact of these findings on the calculation of hadron spectra

17 CFR 8.06 - Investigations.

Science.gov (United States)

2010-04-01

....06 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION EXCHANGE PROCEDURES FOR DISCIPLINARY, SUMMARY, AND MEMBERSHIP DENIAL ACTIONS Disciplinary Procedure § 8.06 Investigations. (a) Each exchange shall establish and maintain a disciplinary procedure which requires the enforcement staff of the...

Loading of microcontainers for oral drug delivery

DEFF Research Database (Denmark)

Marizza, Paolo

The pharmaceutical research is facing several obstacles in the development of drug products for the oral delivery. The main problem deals with the intrinsic chemical nature of the new drug candidates, which are often poorly soluble and barely absorbed in the gastro-intestinal tract. Furthermore......, they are usually degraded before they are absorbed. These combined factors considerably reduce the bioavailability of many active ingredients. Several strategies have been developed to overcome these challenges. One of them are microfabricated drug delivery devices. Microreservoir based-systems are characterized...... of UV photolithography was developed. The fabrication of polymer patterns was optimized and loading with both small hydrophobic drugs and proteins was demonstrated. Finally, structural properties of hydrogels were elucidated by rheology and NMR with the perspective of controlling the drug release...

Poincare group, SU(3) and V-A in leptonic decay

International Nuclear Information System (INIS)

Boehm, A.

1975-07-01

From as few assumptions as possible about the relations between the Poincare group, the particle classifying SU(3) and V-A we derive properties of the K/sub l 3 / and K/sub L 2 / decays. From the assumed relation between SU(3) and the Poincare group and the first class condition it follows that the formfactor ratio Xi of K/sub l 3 / decay is Xi = --0.57, and that a value of Xi = 0 is in disagreement with very general and well accepted theoretical assumptions. Assuming universality of V-A, the Cabibbo suppression is derived from the relations between SU(3) and V-A as a consequence of the brokenness of SU(3). (U.S.)

Diagnostic accuracy of soluble urokinase plasminogen activator receptor (suPAR) for prediction of bacteremia in patients with systemic inflammatory response syndrome.

Science.gov (United States)

Hoenigl, Martin; Raggam, Reinhard B; Wagner, Jasmin; Valentin, Thomas; Leitner, Eva; Seeber, Katharina; Zollner-Schwetz, Ines; Krammer, Werner; Prüller, Florian; Grisold, Andrea J; Krause, Robert

2013-02-01

Soluble urokinase plasminogen activator receptor (suPAR) serum concentrations have recently been described to reflect the severity status of systemic inflammation. In this study, the diagnostic accuracy of suPAR, C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) to predict bacteremia in patients with systemic inflammatory response syndrome (SIRS) was compared. A total of 132 patients with SIRS were included. In 55 patients blood cultures had resulted positive (study group 1, Gram positive bacteria: Staphylococcus aureus and Streptococcus spp., n=15; study group 2, Gram-negative bacteria, n=40) and 77 patients had negative blood culture results (control group, n=77). Simultaneously with blood cultures suPAR, CRP, PCT, IL-6 and white blood count (WBC) were determined. SuPAR values were significantly higher in study group 1 (median 8.11; IQR 5.78-15.53; p=0.006) and study group 2 (median 9.62; IQR 6.52-11.74; p<0.001) when compared with the control group (median 5.65; IQR 4.30-7.83). ROC curve analysis revealed an AUC of 0.726 for suPAR in differentiating SIRS patients with bacteremia from those without. The biomarkers PCT and IL-6 showed comparable results. Regarding combinations of biomarkers multiplying suPAR, PCT and IL-6 was most promising and resulted in an AUC value of 0.804. Initial suPAR serum concentrations were significantly higher (p=0.028) in patients who died within 28 days than in those who survived. No significant difference was seen for PCT, IL-6 and CRP. In conclusion, suPAR, IL-6 and PCT may contribute to predicting bacteremia in SIRS patients. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Static forces in d=2+1 SU(N) gauge theories

International Nuclear Information System (INIS)

Meyer, H.B.

2006-07-01

Using a three-level algorithm we perform a high-precision lattice computation of the static force up to 1fm in the 2+1 dimensional SU(5) gauge theory. Discretization errors and the continuum limit are discussed in detail. By comparison with existing SU(2) and SU(3) data it is found that σr 2 0 =1.65-(π)/(24) holds at an accuracy of 1% for all N≥2, where r 0 is the Sommer reference scale. The effective central charge c(r) is obtained and an intermediate distance r s is defined via the property c(r s )=(π)/(24). It separates in a natural way the short-distance regime governed by perturbation theory from the long-distance regime described by an effective string theory. The ratio τ s /τ 0 decreases significantly from SU(2) to SU(3) to SU(5), where r s 0 . We give a preliminary estimate of its value in the large-N limit. The static force in the smallest representation of N-ality 2, which tends to the k=2 string tension as r→∞, is also computed up to 0.7 fm. The deviation from Casimir scaling is positive and grows from 0.1% to 1% in that range. (Orig.)

Serum suPAR in patients with FSGS: trash or treasure?

Science.gov (United States)

Maas, Rutger J H; Deegens, Jeroen K J; Wetzels, Jack F M

2013-07-01

The urokinase-type plasminogen activator receptor (uPAR) has important functions in cell migration. uPAR can be shed from the cell membrane resulting in soluble uPAR (suPAR). Further cleavage gives rise to shorter fragments with largely unknown functions. Recent studies have demonstrated that both overexpression of uPAR on podocytes and the administration of suPAR cause proteinuria in mice. The common pathogenic mechanism involves the activation of podocyte β3-integrin. Increased activation of β3-integrin is also observed in patients with focal and segmental glomerulosclerosis (FSGS). These observations form the basis for the hypothesis that suPAR may be the circulating factor causing FSGS. A recent study fosters this idea by demonstrating increased suPAR levels in the serum of patients with FSGS and reporting an association with recurrence after transplantation and response to plasmapheresis. However, this study was heavily biased, and subsequent studies have given conflicting results. Although the experimental work is very suggestive, at present there is no proof that any known human suPAR fragment causes FSGS in humans. We therefore suggest that the measurement of suPAR using currently available assays has absolutely no value at the present time in decision-making in routine clinical practice.

The phase transition in the SU(5) model at high temperatures

International Nuclear Information System (INIS)

Daniel, M.; Vayonakis, C.E.

1981-01-01

Within the minimum GUT model we have studied the nature of the fluctuation-induced transition between the SU(5) and the SU(3)sub(c) x SU(2) x U(1) phase which occurs at high temperatures. Our analysis is limited to the case when the phase transition occurs outside the critical (fluctuation-dominated) region. For this to happen the SU(5) model has to be in a mode analogous to the type I superconductor. This corresponds to having the scalar quartic couplings in the Higgs sector less than the squared gauge coupling. For generic values of the coupling constants the phase transition is found to be weakly first order. As we approach the boundaries for the region of the SU(3)sub(c) x SU(2) x U(1) phase, however, a strong first-order transition occurs. The SU(5) mode (analogous to the type II superconductor) when the phase transition occurs inside the fluctuation-dominated region has been recently studied by Ginsparg. His results together with ours show that there is a continuous merging of the type I mode into the type II mode. Finally our analysis elucidates some aspects of the monopole problem in grand unified theories. (orig.)

Strong coupling and quasispinor representations of the SU(3) rotor model

International Nuclear Information System (INIS)

Rowe, D.J.; De Guise, H.

1992-01-01

We define a coupling scheme, in close parallel to the coupling scheme of Elliott and Wilsdon, in which nucleonic intrinsic spins are strongly coupled to SU(3) spatial wave functions. The scheme is proposed for shell-model calculations in strongly deformed nuclei and for semimicroscopic analyses of rotations in odd-mass nuclei and other nuclei for which the spin-orbit interaction is believed to play an important role. The coupling scheme extends the domain of utility of the SU(3) model, and the symplectic model, to heavy nuclei and odd-mass nuclei. It is based on the observation that the low angular-momentum states of an SU(3) irrep have properties that mimic those of a corresponding irrep of the rotor algebra. Thus, we show that strongly coupled spin-SU(3) bands behave like strongly coupled rotor bands with properties that approach those of irreducible representations of the rigid-rotor algebra in the limit of large SU(3) quantum numbers. Moreover, we determine that the low angular-momentum states of a strongly coupled band of states of half-odd integer angular momentum behave to a high degree of accuracy as if they belonged to an SU(3) irrep. These are the quasispinor SU(3) irreps referred to in the title. (orig.)

Sığır Etinde Su Tutma Kapasitesi ve Serbest Su Oranı Değişimi Üzerine bir Araştırma

Directory of Open Access Journals (Sweden)

Aydın Öztan

2015-02-01

Full Text Available Kesimden sonra ette pH değişimi, etin serbest su oranı ve su tutma kapasitesinin belirlenmesinde en önemli kriterdir. Bu araştırmada; 12 adet sığır karkasında M. Trapezius kasında kesimde, kesimden 1 saat 24 saat ve 48 saat sonra pH ölçümleri yapılmış, kompressium yöntemi ile serbest su oranı ve üç farklı yöntemle su tutma kapasitesi saptanmıştır. Pres yönteminde; süzgeç kağıtlarında toplam su alanı (T ve et alanı (Ev ek scanner ile taranmış, bilgisayarda alan ölçümleri yapılmıştır. PH-değeri bakımından zaman ve hayvan değişkenleri önemli bulunmuştur. Ette serbest su oranı rigor mortis döneminde (24 saat artmış, daha sonra düşmeye başlamıştır. Örneklerde su tutma kapasitesi kesimden başlayarak olgunlaşma periyodunda rigor mortis sonuna kadar düşmüş, daha sonra yükselmeye başlamıştır.

31 CFR 281.8 - Reporting and accounting.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Reporting and accounting. 281.8 Section 281.8 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL... Reporting and accounting. The Treasury Department will maintain a system of central accounting and reporting...

Preocupaciones del adolescente desde su propia óptica

Directory of Open Access Journals (Sweden)

Gloria Robaina Suárez

2001-02-01

Full Text Available Se realizó un estudio descriptivo prospectivo a una muestra de 197 adolescentes de la Escuela Secundaria Básica Urbana "Tupac Amaru", de Alamar, curso 1998-1999, para conocer, desde su óptica, sus inquietudes fundamentales. Aplicada una técnica proyectiva, conocimos sus preocupaciones generales por grado y con este resultado preliminar se confeccionaron 3 encuestas para profundizar. Los adolescentes de 7mo grado refirieron como primera preocupación sus aspiraciones futuras, siendo el estudio la principal, seguida de la felicidad y la salud familiar. Los de 8vo señalaron primero la escuela y lo relacionado con ella, seguido de la recreación y dificultades para emplear el tiempo libre. La esfera sexual ya aparece en tercer lugar. Los problemas sociales ocupan el primer lugar para los de 9no grado, no sintiendo que satisfacen sus dudas. Los cambios de su edad y la recreación completan sus preocupacionesA descriptive and prospective study of a sample of 197 adolescents from "Tupac Amaru" Urban Secondary Basic School, in Alamar, academic course 1998-1999, was carried out to know their main preoccupations from their own view. After applying a projective technique, we were able to know their general preoccupations by school grade and with this preliminary result 3 surveys were done to go deep into this subject. The adolescents from 7th grade referred as their first preoccupation their future aspirations. Studying was number one followed by happiness and family health. Students from 8th grade mentioned first the school and everything related to it, followed by recreation and the difficulties to use their free time. The sexual sphere appeared in the third place. Social problems are in the first place for those in 9th grade and they feel that their doubts are not satisfied. The changes of age and recreation complete their preoccupations

Neutrino masses in the flipped SU(5) x U(1) and the SU(4) x O(4) GUT models

Energy Technology Data Exchange (ETDEWEB)

Ranfone, S.; Papageorgiu, E.

1992-03-01

We classify the different neutrino-mass pattern arising in string-inspired Grand Universal Theory (GUT) and supersymmetric GUT models based on the flipped SU(5)xU(1) and the SU(4)xO(4) gauge groups. Phenomenologically interesting spectra are obtained through the interplay of the two seesaw mechanisms present, with typical neutrino masses {approx}10{sup -3} eV in the supersymmetric GUT models and of order 0.1 - 10 KeV in the ordinary GUTs. (author).

Neutrino masses in the flipped SU(5)xU(1) and the SU(4)xO(4) GUT models

Energy Technology Data Exchange (ETDEWEB)

Papageorgiu, E.; Ranfone, S. (Rutherford Appleton Lab., Chilton (United Kingdom))

1992-05-21

We classify the different neutrino-mass patterns arising in string-inspired GUT and supersymmetric GUT models based on the flipped SU(5)xU(1) and the SU(4)xO(4) gauge groups. Phenomenologically interesting spectra are obtained through the interplay of the two seesaw mechanisms present, with typical neutrino masses {proportional to}10{sup -3} eV in the supersymmetric GUT models and of order 0.1-10 keV in the ordinary GUTs. (orig.).

SU(2) X SU(2) X U(1) basis for symmetric SO(6) representations: matrix elements of the generators

International Nuclear Information System (INIS)

Piepenbring, R.; Silvestre-Brac, B.; Szymanski, Z.

1987-01-01

Matrix elements of the group generators for the symmetric irreducible representations of SO(6) are explicitly calculated in a closed form employing thedecomposition chain SO(6) is contained in SU(2) X SU(2) X U(1) (which is different from the well known Wigner supermultiplet scheme). The relation to the Gel'fand Tsetlin method using SO(6) contained in SO(5) up to ... SO(2) is indicated. An example of a physical application is given

On the Weyl character formula for SU(n)

International Nuclear Information System (INIS)

Plymen, R.J.

1976-01-01

A straight line is drawn between the representation theory of SU(3) and the SU(3)-classification schemes in particle physics. The approach is based on that of Weyl (The Theory of Groups and Quantum Mechanics, Dover, New York, p. 381 (1950)). The present formulation brings an important part of particle physics into line with two contemporary accounts of compact Lie groups. (author)

Phosphorylation of SU(VAR3-9 by the chromosomal kinase JIL-1.

Directory of Open Access Journals (Sweden)

Joern Boeke

2010-04-01

Full Text Available The histone methyltransferase SU(VAR3-9 plays an important role in the formation of heterochromatin within the eukaryotic nucleus. Several studies have shown that the formation of condensed chromatin is highly regulated during development, suggesting that SU(VAR3-9's activity is regulated as well. However, no mechanism by which this may be achieved has been reported so far. As we and others had shown previously that the N-terminus of SU(VAR3-9 plays an important role for its activity, we purified interaction partners from Drosophila embryo nuclear extract using as bait a GST fusion protein containing the SU(VAR3-9 N-terminus. Among several other proteins known to bind Su(VAR3-9 we isolated the chromosomal kinase JIL-1 as a strong interactor. We show that SU(VAR3-9 is a substrate for JIL-1 in vitro as well as in vivo and map the site of phosphorylation. These findings may provide a molecular explanation for the observed genetic interaction between SU(VAR3-9 and JIL-1.

Las redes sociales y su modelado matemático

OpenAIRE

Ortega Guerrero, Juan Carlos

2017-01-01

Las tecnologías de la información y comunicación (TIC) han venido a cambiar el potencial de las redes sociales. Su diversidad, alcance y características resultan impactantes y su análisis matemático es importante para comprenderlas. En este capítulo se revisan los conceptos básicos de las redes, veremos cómo se generan las redes complejas y sus características principales; en especial se analizan las redes de mundo pequeño y su uso para modelar las redes sociales, finalmente se enuncian algun...

External corrosion of tanks 8D-1 and 8D-2. Final report

International Nuclear Information System (INIS)

Mackey, D.B.; Westerman, R.E.

1995-05-01

Tanks 8D-1 and 8D-2 at the West Valley Nuclear Services (WVNS) site, West Valley, New York, rest on layers of perlite brick contained within steel pans. The pans tend to collect water, which can contact the tanks directly and which also can be ''wicked'' to the external surfaces of the tank through the perlite brick. The presence of air in the tank vault is conducive to the formation of oxygen concentration cells, which can promote localized corrosion of the carbon steel tank wall. Pacific Northwest Laboratory conducted an experiment to estimate the extent to which the external surfaces of the tanks could have corroded in the 30 years since their construction. Specimens of carbon steel, similar to that used in the tank construction, were partially embedded in an upright position in particulate perlite in closed containers. The water line in the containers.was maintained at two levels: above the perlite level (high water level tests) and below the bottoms of the specimens (low water level tests). The water used in the tests was obtained from the pan of tank 8D-1. The containers were maintained in an aerated condition. Specimens were examined after 3-, 6-, 12-, 18-, 24-, and 30-month exposures

Experimental consequences of SU(3) symmetry in an sdg boson model

International Nuclear Information System (INIS)

Akiyama, Y.; Brentano, P. von; Gelberg, A.

1987-01-01

Energies of collective levels in 178 Hf and 234 U are compared wth predictions of the SU(3) limiz of the sdg interacting boson model. All known positive parity states of 178 Hf below 1.8 MeV (with the expection of a 0 + band) have been satisfactorily reproduced. Most of the bands in 234 U are also described by the model. However, a few predicted states have no experimental counterpart. The introduction of the g-basons strongly reduces the previously observed discrepancies between experimental B(E2)'s in 238 U and the sd-IBM calculation. (orig.)

Sušárny uzenin

OpenAIRE

Čermák, Lubomír

2008-01-01

Tato práce je věnována základním požadavkům technologie sušení a zrání masných výrobků ve zracích komorách. Bude zmíněno základní rozdělení salámů a z toho plynoucí parametry pro zrací komory a jak ovlivňuje hygiena a sanitace celkovou produktivitu. Podrobně bude popsána technologie sušení. Stručně bude popsána fermentace a zrání jako takové. The thesis deals with essential requirements to dry and cure meat products using drying chambers. It covers the basic salami classification, the rele...

AECL's reliability and maintainability program

International Nuclear Information System (INIS)

Wolfe, W.A.; Nieuwhof, G.W.E.

1976-05-01

AECL's reliability and maintainability program for nuclear generating stations is described. How the various resources of the company are organized to design and construct stations that operate reliably and safely is shown. Reliability and maintainability includes not only special mathematically oriented techniques, but also the technical skills and organizational abilities of the company. (author)

Exact scattering in the SU(n) supersymmetric principal chiral model

CERN Document Server

Evans, J M; Evans, Jonathan M; Hollowood, Timothy J

1997-01-01

The complete spectrum of states in the supersymmetric principal chiral model based on SU(n) is conjectured, and an exact factorizable S-matrix is proposed to describe scattering amongst these states. The SU(n)_L*SU(n)_R symmetry of the lagrangian is manifest in the S-matrix construction. The supersymmetries, on the other hand, are incorporated in the guise of spin-1/2 charges acting on a set of RSOS kinks associated with su(n) at level n. To test the proposed S-matrix, calculations of the change in the ground-state energy in the presence of a coupling to a background charge are carried out. The results derived from the lagrangian using perturbation theory and from the S-matrix using the TBA are found to be in complete agreement for a variety of background charges which pick out, in turn, the highest weight states in each of the fundamental representations of SU(n). In particular, these methods rule out the possibility of additional CDD factors in the S-matrix. Comparison of the expressions found for the free-...

Nonperturbative flipped SU(5) vacua in heterotic M-theory

Energy Technology Data Exchange (ETDEWEB)

Faraggi, Alon E. E-mail: faraggi@thphys.ox.ac.uk; Garavuso, Richard E-mail: garavuso@thphys.ox.ac.uk; Isidro, Jose M. E-mail: isidro@thphys.ox.ac.uk

2002-10-07

The evidence for neutrino masses in atmospheric and solar neutrino experiments provides further support for the embedding of the Standard Model fermions in the chiral 16 SO(10) representation. Such an embedding is afforded by the realistic free fermionic heterotic-string models. In this paper we advance the study of these string models toward a nonperturbative analysis by generalizing the work of Donagi, Pantev, Ovrut and Waldram from the case of G=SU(2n+1) to G=SU(2n) stable holomorphic vector bundles on elliptically fibered Calabi-Yau manifolds with fundamental group Z{sub 2}. We demonstrate existence of G=SU(4) solutions with three generations and SO(10) observable gauge group over Hirzebruch base surface, whereas we show that certain classes of del Pezzo base surface do not admit such solutions. The SO(10) symmetry is broken to SU(5)xU(1) by a Wilson line. The overlap with the realistic free fermionic heterotic-string models is discussed.

SU(N ) fermions in a one-dimensional harmonic trap

Science.gov (United States)

Laird, E. K.; Shi, Z.-Y.; Parish, M. M.; Levinsen, J.

2017-09-01

We conduct a theoretical study of SU (N ) fermions confined by a one-dimensional harmonic potential. First, we introduce a numerical approach for solving the trapped interacting few-body problem, by which one may obtain accurate energy spectra across the full range of interaction strengths. In the strong-coupling limit, we map the SU (N ) Hamiltonian to a spin-chain model. We then show that an existing, extremely accurate ansatz—derived for a Heisenberg SU(2) spin chain—is extendable to these N -component systems. Lastly, we consider balanced SU (N ) Fermi gases that have an equal number of particles in each spin state for N =2 ,3 ,4 . In the weak- and strong-coupling regimes, we find that the ground-state energies rapidly converge to their expected values in the thermodynamic limit with increasing atom number. This suggests that the many-body energetics of N -component fermions may be accurately inferred from the corresponding few-body systems of N distinguishable particles.

Flipping SU(5) out of Trouble

CERN Document Server

Ellis, Jonathan Richard; Walker, J; Ellis, John

2002-01-01

Minimal supersymmetric SU(5) GUTs are being squeezed by the recent values of alpha_s, sin^2 theta_W, the lower limit on the lifetime for p to nubar K decay, and other experimental data. We show how the minimal flipped SU(5) GUT survives these perils, accommodating the experimental values of alpha_s and sin^2 theta_W and other constraints, while yielding a p to e/mu+ pi0 lifetime beyond the present experimental limit but potentially accessible to a further round of experiments. We exemplify our analysis using a set of benchmark supersymmetric scenarios proposed recently in a constrained MSSM framework.

SU(3)xSU(2) color symmetry and Usub(B)(1)xSUsub(f)(4) quark model of hadrons

International Nuclear Information System (INIS)

Khrushchov, V.V.

1982-01-01

A quark model with a generalized color group SUsub(c)(3)xSU'sub(c)(2) is treated in the framework of the SUsub(f)(4)xUsub(B)(1) symnetry of strong interactions. The model contains twelve standard u, d, s, c quarks and new quarks belonging to representation 6 of the SU(4) group. The properties of new quarks are considered with respect to the color group and some properties of the exotic states, predicted by the model are presented

Denominator function for canonical SU(3) tensor operators

International Nuclear Information System (INIS)

Biedenharn, L.C.; Lohe, M.A.; Louck, J.D.

1985-01-01

The definition of a canonical unit SU(3) tensor operator is given in terms of its characteristic null space as determined by group-theoretic properties of the intertwining number. This definition is shown to imply the canonical splitting conditions used in earlier work for the explicit and unique (up to +- phases) construction of all SU(3) WCG coefficients (Wigner--Clebsch--Gordan). Using this construction, an explicit SU(3)-invariant denominator function characterizing completely the canonically defined WCG coefficients is obtained. It is shown that this denominator function (squared) is a product of linear factors which may be obtained explicitly from the characteristic null space times a ratio of polynomials. These polynomials, denoted G/sup t//sub q/, are defined over three (shift) parameters and three barycentric coordinates. The properties of these polynomials (hence, of the corresponding invariant denominator function) are developed in detail: These include a derivation of their degree, symmetries, and zeros. The symmetries are those induced on the shift parameters and barycentric coordinates by the transformations of a 3 x 3 array under row interchange, column interchange, and transposition (the group of 72 operations leaving a 3 x 3 determinant invariant). Remarkably, the zeros of the general G/sup t//sub q/ polynomial are in position and multiplicity exactly those of the SU(3) weight space associated with irreducible representation [q-1,t-1,0]. The results obtained are an essential step in the derivation of a fully explicit and comprehensible algebraic expression for all SU(3) WCG coefficients

Generators of the exceptional group E8 as bilinear quark and lepton fields

International Nuclear Information System (INIS)

Koca, M.

1981-01-01

The quarks and leptons are assigned to the adjoint representation of the exceptional group E 8 using decompositions under the subgroups SU(9) and [SU(3)] 4 . Generators are constructed as linear combinations of bilinear quark and lepton fields. Closure of the algebra is used to determine the unknown coefficients of the linear combinations. It is noted that the Majorana spinors chi/sup μ//sub ν/ introduced to represent the adjoint representations of SU(9) and [SU(3)] 4 subgroups cannot be taken traceless. The trace chi/sup μ//sub ν/ should couple to the quark and lepton fields in order to close the algebra. The constraints on the bilinear fields which are of physical importance are introduced to obtain the right number of fermionic states in the adjoint representation. An attractive possibility of having an octet of strictly massless Majorana quarks and at least three massless Majorana leptons as a consequence of pure algebraic constraints is discussed. The exceptional subgroups E 7 and E 6 are identified and the explicit commutation relations are obtained. Using one assignment of E 6 the role of color-singlet lepton-lepton and quark-antiquark currents is pointed out

On some properties of SU(3 fusion coefficients

Directory of Open Access Journals (Sweden)

Robert Coquereaux

2016-11-01

Full Text Available Three aspects of the SU(3 fusion coefficients are revisited: the generating polynomials of fusion coefficients are written explicitly; some curious identities generalizing the classical Freudenthal–de Vries formula are derived; and the properties of the fusion coefficients under conjugation of one of the factors, previously analyzed in the classical case, are extended to the affine algebra suˆ(3 at finite level.

String completion of an SU(3c⊗SU(3L⊗U(1X electroweak model

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Andrea Addazi

2016-08-01

Full Text Available The extended electroweak SU(3c⊗SU(3L⊗U(1X symmetry framework “explaining” the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (unoriented open strings, on Calabi–Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron–antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.

Is neutralino dark matter compatible with flipped SU(5) models

Energy Technology Data Exchange (ETDEWEB)

McDonald, J.

1989-07-13

We consider the possibility that the lightest supersymmetric particle in flipped SUSY SU(5)xU(1) models is cosmologically stable and corresponds to a neutralino. Previous studies of dark matter in flipped SUSY SU(5) models have suggested that the decay of the oscillations of the SU(5) breaking scalar field would result in too many neutralinos, if they are stable. We show that it is possible for an acceptable density of neutralinos to occur in the case where the neutralino corresponds to a light photino, if the temperature at the end of the oscillation dominated period is SU(5) models. Direct detection of dark matter in forthcoming experiments will therefore not eliminate this class of models. (orig.).

Effect of a physical activity intervention on suPAR levels

DEFF Research Database (Denmark)

Rohde, Christopher; Polcwiartek, Christoffer; Andersen, Eivind

2018-01-01

OBJECTIVES: Soluble urokinase-type plasminogen activator receptor (suPAR) is a novel inflammatory marker, associated with lifestyle diseases and mortality risk. No studies have investigated whether physical activity may reduce suPAR levels using a randomized controlled design. DESIGN AND METHODS......: suPAR and C-reactive protein (CRP) levels were determined in blood samples from a previous randomized controlled trial with Pakistani immigrants in Norway, 2008. The study included physically inactive men that were randomized to an intervention group (supervised group exercises) or a control group...... and followed for 5 months. A linear regression model was used and adjusted for age, inactivity level at baseline, and mean difference in CRP levels. RESULTS: Overall, 80 and 53 participants were included in the intervention and control group, respectively. Obesity and smoking were associated with higher su...

SU (N ) spin-wave theory: Application to spin-orbital Mott insulators

Science.gov (United States)

Dong, Zhao-Yang; Wang, Wei; Li, Jian-Xin

2018-05-01

We present the application of the SU (N ) spin-wave theory to spin-orbital Mott insulators whose ground states exhibit magnetic orders. When taking both spin and orbital degrees of freedom into account rather than projecting Hilbert space onto the Kramers doublet, which is the lowest spin-orbital locked energy levels, the SU (N ) spin-wave theory should take the place of the SU (2 ) one due to the inevitable spin-orbital multipole exchange interactions. To implement the application, we introduce an efficient general local mean-field method, which involves all local fluctuations, and develop the SU (N ) linear spin-wave theory. Our approach is tested firstly by calculating the multipolar spin-wave spectra of the SU (4 ) antiferromagnetic model. Then, we apply it to spin-orbital Mott insulators. It is revealed that the Hund's coupling would influence the effectiveness of the isospin-1 /2 picture when the spin-orbital coupling is not large enough. We further carry out the SU (N ) spin-wave calculations of two materials, α -RuCl3 and Sr2IrO4 , and find that the magnonic and spin-orbital excitations are consistent with experiments.

Paul Karl Feyerabend. En Defensa de la Continuidad de su Pensamiento

Directory of Open Access Journals (Sweden)

Teresa Gargiulo

2015-08-01

Full Text Available Entre los estudios críticos que existen en torno a la obra de Paul Feyerabend predominan aquellos que subrayan una discontinuidad radical entre la versión temprana y tardía de su pensamiento. Todo ello contribuye a que dispongamos de una visión fragmentada e incompleta de un pensador que evoluciono hasta el 1994, año de su fallecimiento. Nuestro propósito es ofrecer una explicación de su itinerario intelectual de tal modo que quedé patente su continuidad en la clave de sus críticas contra los falsos absolutos erigidos por el positivismo lógico y el racionalismo científico. Mostraremos las diversas cuestiones que Feyerabend aborda en las distintas épocas de su vida pero, al mismo tiempo, subrayaremos la unidad o coherencia lógica que existe en su revisión crítica de la racionalidad científica. Nos preocuparemos por entender las razones por las cuales nuestro filósofo de la ciencia va trasladando sus distintos focos de discusión o crítica.

Teresita Gómez: su música, un canto interior

Directory of Open Access Journals (Sweden)

Marta Elena Bravo Betancur

2007-04-01

Full Text Available Teresita Gómez es una de las pianistas más destacadas y queridas en el contexto musical colombiano. Las autoras de este texto buscan un acercamiento personal a la artista para dar cuenta de su forma maravillosa de adentrarse en el mundo de la música y lograr una interpretación tan original de sus artistas preferidos. El artículo da cuenta del recorrido vital por momentos significativos de su existencia llena de luchas y de enormes satisfacciones como intérprete y profesora, así como por su reconocida trayectoria a través de escenarios nacionales e internacionales.

New Bessel-type function associated with SU(3) representation

International Nuclear Information System (INIS)

Tanimura, N.; Tanimura, O.

1990-01-01

A new set of functions that are given by the coefficients of the character expansion of the single-link action in the SU(3) lattice-gauge theory is studied. The function is specified by the indices λ and μ of the SU(3) representation of the Young tableau. From the Schwinger-Dyson variational method the recursion relations among the functions are derived. By combining the recursion relation and the relation of the differentiation, the linear differential equation of the sixth order for the function is derived. The properties of the function are discussed in detail in comparison with the functions in the SU(2) group

Effect of simvastatin and ezetimibe on suPAR levels and outcomes

DEFF Research Database (Denmark)

Hodges, Gethin W; Bang, Casper N; Forman, Julie L

2018-01-01

-lowering therapy also lowers suPAR levels is unknown. METHODS: We investigated whether treatment with Simvastatin 40 mg and Ezetimibe 10 mg lowered plasma suPAR levels in 1838 patients with mild-moderate, asymptomatic aortic stenosis, included in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, using...... and Ezetimibe treatment impeded the progression of the time-related increase in plasma suPAR levels. Year-1 suPAR was associated with all-cause mortality, MCE, and AVE irrespective of baseline levels (SEAS study: NCT00092677)....... cardiovascular events (MCE) composed of ischemic cardiovascular events (ICE) and aortic valve related events (AVE). RESULTS: After 4.3 years of follow-up, suPAR levels had increased by 9.2% (95% confidence interval [CI]: 7.0%-11.5%) in the placebo group, but only by 4.1% (1.9%-6.2%) in the group with lipid...

Licensee programs for maintaining occupational exposure to radiation as low as is reasonably achievable

International Nuclear Information System (INIS)

Munson, L.H.

1983-06-01

This report defines the concept of maintaining occupational exposures to radiation as low as is reasonably achievable (ALARA) and describes the elements necessary for specific licensees to implement, operate, and evaluate an effective ALARA program. Examples of cost-effectiveness analysis and optimization are provided. The rationale for providing more detailed guidance to specific licensees stems from the current recommendations provided by the International Commission on Radiological Protection, as well as from the increased regulatory emphasis on maintaining occupational exposures ALARA. The objective of this work is to provide the Nuclear Regulatory Commission with a basis for updating Regulatory Guide 8.10

Baryon number generation in a flipped SU(5) x U(1) model

International Nuclear Information System (INIS)

Campbell, B.; Hagelin, J.; Nanopoulos, D.V.; Olive, K.A.

1988-01-01

We consider the possibilities for generating a baryon asymmetry in the early universe in a flipped SU(5) x U(1) model inspired by the superstring. Depending on the temperature of the radiation background after inflation we can distinguish between two scenarios for baryogenesis: (1) After reheating the original SU(5) x U(1) symmetry is restored, or there was no inflation at all; (2) reheating after inflation is rather weak and SU(5) x U(1) is broken. In either case the asymmetry is generated by the out-of-equilibrium decays of a massive SU(3) x SU(2) x U(1) singlet field φ m . In the flipped SU(5) x U(1) model, gauge symmetry breaking is triggered by strong coupling phenomena, and is in general accompanied by the production of entropy. We examine constraints on the reheating temperature and the strong coupling scale in each of the scenarios. (orig.)

Maintaining positive

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