6,970 research outputs found
Large N, chiral approach to M at finite temperature
We study the temperature dependence of the eta and eta[prime] meson masses within the framework of U(3)LĂ—U(3)R chiral perturbation theory, up to next-to-leading order in a simultaneous expansion in momenta, quark masses and number of colors. We find that both masses decrease at low temperatures, but only very slightly. We analyze higher order corrections and argue that large Nc suggests a discontinuous drop of Meta[prime] at the critical temperature of deconfinement Tc, consistent with a first order transition to a phase with approximate U(1)A symmetry
Bioink properties before, during and after 3D bioprinting
Bioprinting is a process based on additive manufacturing from materials containing living cells. These materials, often referred to as bioink, are based on cytocompatible hydrogel precursor formulations, which gel in a manner compatible with different bioprinting approaches. The bioink properties before, during and after gelation are essential for its printability, comprising such features as achievable structural resolution, shape fidelity and cell survival. However, it is the final properties of the matured bioprinted tissue construct that are crucial for the end application. During tissue formation these properties are influenced by the amount of cells present in the construct, their proliferation, migration and interaction with the material. A calibrated computational framework is able to predict the tissue development and maturation and to optimize the bioprinting input parameters such as the starting material, the initial cell loading and the construct geometry. In this contribution relevant bioink properties are reviewed and discussed on the example of most popular bioprinting approaches. The effect of cells on hydrogel processing and vice versa is highlighted. Furthermore, numerical approaches were reviewed and implemented for depicting the cellular mechanics within the hydrogel as well as for prediction of mechanical properties to achieve the desired hydrogel construct considering cell density, distribution and material-cell interaction
The Upgrade of the CMS RPC System during the First LHC Long Shutdown
The CMS muon system includes in both the barrel and endcap region Resistive
Plate Chambers (RPC). They mainly serve as trigger detectors and also improve
the reconstruction of muon parameters. Over the years, the instantaneous
luminosity of the Large Hadron Collider gradually increases. During the LHC
Phase 1 (~first 10 years of operation) an ultimate luminosity is expected above
its design value of 10^34/cm^2/s at 14 TeV. To prepare the machine and also the
experiments for this, two long shutdown periods are scheduled for 2013-2014 and
2018-2019. The CMS Collaboration is planning several detector upgrades during
these long shutdowns. In particular, the muon detection system should be able
to maintain a low-pT threshold for an efficient Level-1 Muon Trigger at high
particle rates. One of the measures to ensure this, is to extend the present
RPC system with the addition of a 4th layer in both endcap regions. During the
first long shutdown, these two new stations will be equipped in the region
|eta|<1.6 with 144 High Pressure Laminate (HPL) double-gap RPCs operating in
avalanche mode, with a similar design as the existing CMS endcap chambers.
Here, we present the upgrade plans for the CMS RPC system for the fist long
shutdown, including trigger simulation studies for the extended system, and
details on the new HPL production, the chamber assembly and the quality control
procedures.Comment: 9 pages, 6 figures, presented by M.Tytgat at the XI workshop on
Resistive Plate Chambers and Related Detectors (RPC2012), INFN - Laboratori
Nazionali di Frascati, February 5-10, 201
Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter
A large prototype of 1.3m3 was designed and built as a demonstrator of the
semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC
experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each
unit is built of an active layer made of 1m2 Glass Resistive Plate
Chamber(GRPC) detector placed inside a cassette whose walls are made of
stainless steel. The cassette contains also the electronics used to read out
the GRPC detector. The lateral granularity of the active layer is provided by
the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a
self-supporting mechanical structure built also of stainless steel plates
which, with the cassettes walls, play the role of the absorber. The prototype
was designed to be very compact and important efforts were made to minimize the
number of services cables to optimize the efficiency of the Particle Flow
Algorithm techniques to be used in the future ILC experiments. The different
components of the SDHCAL prototype were studied individually and strict
criteria were applied for the final selection of these components. Basic
calibration procedures were performed after the prototype assembling. The
prototype is the first of a series of new-generation detectors equipped with a
power-pulsing mode intended to reduce the power consumption of this highly
granular detector. A dedicated acquisition system was developed to deal with
the output of more than 440000 electronics channels in both trigger and
triggerless modes. After its completion in 2011, the prototype was commissioned
using cosmic rays and particles beams at CERN.Comment: 49 pages, 41 figure
Normal Histological Appearances of the Duodenum Jejunum and Terminal Ileum in Indonesian People
Background: There is no literature specifically on the normal appearance of small bowel mucosa amongst Indonesians. Diseases of the small bowel can cause chronic diarrhea. Chronic diarrhea is common in Indonesia. Methods: Thirty seven patients with normal stomach and small bowel on endoscopic and histopathologic examination were included in this study. Biopsies were taken from the duodenal bulb, descending part of duodenum, jejunum and terminal ileum. The scoring Method for the inflammatory cells (lymphocytes, plasma cells and eosinophil cells) was carried out using the symbols 0 (negative), +, ++, and +++. Results: The mean height of the villi of the duodenal bulb was 265.00 ± 81.89 mm, the mean height of the crypts of the duodenal bulb was 196.67 ± 56.01 mm, the mean width of the villi were 59.14 ± 74.14 mm. The mean height of the villi of the duodenum pars descendens was 317.27 ± 99.66 mm and the mean height of the crypts was 218.79 ± 84.66 mm. The mean height of the villi of the jejunum was 341.76 ± 76.06 mm and the mean height of the crypts was 189.41 ± 58.15 mm. The mean height of the villi of the terminal ileum was 235.41 ± 73.32 mm, and the mean height of the crypts was 186.22 ± 64.09 mm. Conclusion: Histologically, the mean height of the villi of the normal small bowel was between 235.41 ± 73.32 to 341.76 ± 76.06 mm and the mean height of the crypts of the normal small bowel was between 186.22 ± 64.09 to 218.79 ± 84.66 mm
Diseases in Chronic Non-infective Diarrhea
Background: Chronic diarrhea is common in Indonesia. The chronic non-infective diarrhea cases seem to be increasing recently. The aim of this study is to reveal the pattern of diseases that can cause chronic non-infective diarrhea. Methods: We examined all patients suffering from chronic non-infective diarrhea over a six years period. The patients underwent physical examination and performed laboratory tests, colon enema X-ray, colonoscopy, ileoscopy, upper gastrointestnal endoscopy and small bowel X-ray. Result: Chronic non-infective diarrhea was observed in 107 (51.7%) cases from 207 chronic diarrhea cases respectively. The frequently found abnormalities that had caused chronic non-infective diarrhea were carbohydrate maldigestion (62.61%), colorectal cancer (14.01%), Crohn's disease (11.21%), ulcerative colitis (9.34%), irritable bowel syndrome (8.41%), colorectal polyp (8.41%) etc. Conclusion: The most frequent abnormality found in chronic non-infective diarrhea was maldigestion
The Inert Doublet Model and Inelastic Dark Matter
The annual modulation observed by DAMA/NaI and DAMA/Libra may be interpreted
in terms of elastic or inelastic scattering of dark matter particles. In this
paper we confront these two scenarios within the framework of a very simple
extension of the Standard Model, the Inert Doublet Model (IDM). In this model
the dark matter candidate is a scalar, the lightest component of an extra Higgs
doublet. We first revisit the case for the elastic scattering of a light scalar
WIMP, M_DM~10 GeV, a scenario which requires that a fraction of events in DAMA
are channelled. Second we consider the possibility of inelastic Dark Matter
(iDM). This option is technically natural in the IDM, in the sense that the
mass splitting between the lightest and next-to-lightest neutral scalars may be
protected by a Peccei-Quinn (PQ) symmetry. We show that candidates with a mass
M_DM between ~535 GeV and ~50 TeV may reproduce the DAMA data and have a cosmic
abundance in agreement with WMAP. This range may be extended to candidates as
light as ~50 GeV if we exploit the possibility that the approximate PQ symmetry
is effectively conserved and that a primordial asymmetry in the dark sector may
survive until freeze-out.Comment: 16 pages, 7 figures. v2: minor changes and discussion on the
embedding in SO(10) added. v3: matches the published version in JCA
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