139 research outputs found
Drawdown prepreg coating method using epoxy terminated butadiene nitrile rubber to improve fracture toughness of glass epoxy composites
Laminates of fibre-reinforced prepreg have excellent in-plane mechanical properties, but have inadequate performance in the through thickness direction. Here, we address this issue by application of epoxy-terminated butadiene nitrile (ETBN) liquid rubber between the prepreg laminae using an automatic draw bar coating technique. Test results reveal that by adding ETBN in small quantities in the range of 9.33–61.33 g/m2, the interlaminar critical energy release rates (GIc and GIIc) are improved by up to 122% in mode-I and 49% in mode-II. Moreover, this finding is further supported by the dynamic mechanical analysis thermograms that clearly indicate that coating has not altered the Tg of ETBN-coated samples. Scanning electron microscopic analysis of fracture surfaces showed that rubber particles formed micro cavitations in the epoxy, causing localised rubber rich regions. These resin-rich regions require more energy to fracture, resulting in increased toughness of the glass epoxy prepreg systems. </jats:p
Evolution of helicity in NOAA 10923 over three consecutive solar rotations
We have studied the evolution of magnetic helicity and chirality in an active
region over three consecutive solar rotations. The region when it first
appeared was named NOAA10923 and in subsequent rotations it was numbered NOAA
10930, 10935 and 10941. We compare the chirality of these regions at
photospheric, chromospheric and coronal heights. The observations used for
photospheric and chromospheric heights are taken from Solar Vector Magnetograph
(SVM) and H_alpha imaging telescope of Udaipur Solar Observatory (USO),
respectively. We discuss the chirality of the sunspots and associated H_alpha
filaments in these regions. We find that the twistedness of superpenumbral
filaments is maintained in the photospheric transverse field vectors also. We
also compare the chirality at photospheric and chromospheric heights with the
chirality of the associated coronal loops, as observed from the HINODE X-Ray
Telescope.Comment: 8 pages, 4 figure
Giant cell tumour of the flexor tendon sheath of the hand
Background: Giant cell tumor of tendon sheath is a benign soft tissue lesion most commonly found in the flexor aspect of hand and wrist. Recurrence of the tumor is common even after excision.Methods: It is an observational study where we present a review of 10 cases for which excision was done and were kept for regular follow up for minimum 6 months.Results: No recurrences noted in our series with minimum six months to maximum two years follow-up though review literature shows 10-40% recurrence rates.Conclusions: Complete excision with regular follow up care is indicated for this neoplasm due to its high propensity towards recurrence. The most important factor deciding recurrence pattern is incomplete excision and leaving behind satellite nodules.
Accelerating Universe from an Evolving Lambda in Higher Dimension
We find exact solutions in five dimensional inhomogeneous matter dominated
model with a varying cosmological constant. Adjusting arbitrary constants of
integration one can also achieve acceleration in our model. Aside from an
initial singularity our spacetime is regular everywhere including the centre of
the inhomogeneous distribution. We also study the analogous homogeneous
universe in (4+d) dimensions. Here an initially decelerating model is found to
give late acceleration in conformity with the current observational demands. We
also find that both anisotropy and number of dimensions have a role to play in
determining the time of flip, in fact the flip is delayed in multidimensional
models. Some astrophysical parameters like the age, luminosity distance etc are
also calculated and the influence of extra dimensions is briefly discussed.
Interestingly our model yields a larger age of the universe compared to many
other quintessential models.Comment: 18 pages, 9 figure
Polaronic Heat Capacity in The Anderson - Hasegawa Model
An exact treatment of the Anderson - Hasegawa two - site model, incorporating
the presence of superexchange and polarons, is used to compute the heat
capacity. The calculated results point to the dominance of the lattice
contribution, especially in the ferromagnetic regime. This behavior is in
qualitative agreement with experimental findings.Comment: 9 pages, Revtex, 4 postscript figure
Kaluza-Klein Type Robertson Walker Cosmological Model With Dynamical Cosmological Term
In this paper we have analyzed the Kaluza-Klein type Robertson Walker (RW)
cosmological models by considering three different forms of variable :
, and
. It is found that, the connecting free parameters of the
models with cosmic matter and vacuum energy density parameters are equivalent,
in the context of higher dimensional space time. The expression for the look
back time, luminosity distance and angular diameter distance are also derived.
This work has thus generalized to higher dimensions the well-known results in
four dimensional space time. It is found that there may be significant
difference in principle at least, from the analogous situation in four
dimensional space time.Comment: 16 pages, no figur
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years
Need-driven dementia-compromised behavior: An alternative view of disruptive behavior
The disruptive behavior of persons with dementia is a problem of considerable clinical interest and growing scientific concern. This paper offers a view of these behaviors as expressions of unmet needs or goals and provides a comprehensive conceptual framework to guide further research and clinical practice. Empiricalfindings and clinical impressions related to wandering, vocalizations and aggression to support and illustrate the framework are presentedPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66887/2/10.1177_153331759601100603.pd
The effects of antiviral treatment on breast cancer cell line
Background: Recent studies have revealed the positive antiproliferative and cytotoxic effects of antiviral agents in
cancer treatment. The real effect of adjuvant antiviral therapy is still controversial due to the lack of studies in biochemical
mechanisms. Here, we studied the effect of the antiviral agent acyclovir on morphometric and migratory features of the
MCF7 breast cancer cell line. Molecular levels of various proteins have also been examined.
Methods: To evaluate and assess the effect of antiviral treatment on morphometric, migratory and other cellular
characteristics of MCF7 breast cancer cells, the following experiments were performed: (i) MTT assay to measure the
viability of MCF7 cells; (ii) Colony formation ability by soft agar assay; (iii) Morphometric characterization by
immunofluorescent analysis using confocal microscopy; (iv) wound healing and transwell membrane assays to
evaluate migration and invasion capacity of the cells; (v) ELISA colorimetric assays to assess expression levels of caspase-3,
E-cadherin and enzymatic activity of aldehyde dehydrogenase (ALDH).
Results: We demonstrate the suppressive effect of acyclovir on breast cancer cells. Acyclovir treatment decreases the
growth and the proliferation rate of cells and correlates with the upregulated levels of apoptosis associated cytokine
Caspase-3. Moreover, acyclovir inhibits colony formation ability and cell invasion capacity of the cancer cells while
enhancing the expression of E-cadherin protein in MCF7 cells. Breast cancer cells are characterized by high
ALDH activity and associated with upregulated proliferation and invasion. According to this study, acyclovir
downregulates ALDH activity in MCF7 cells.
Conclusions: These results are encouraging and demonstrate the possibility of partial suppression of cancer
cell proliferation using an antiviral agent. Acyclovir antiviral agents have a great potential as an adjuvant therapy in the
cancer treatment. However, more research is necessary to identify relevant biochemical mechanisms by which acyclovir
induces a potent anti-cancer effect
Higher Dimensional Cosmological Implications Of A Decay Law For Term : Expressions For Some Observable Quantities
Implications of cosmological model with a cosmological term of the form
, where is a constant, are
analyzed in multidimensional space time. The proper distance, the luminosity
distance-redshift, the angular diameter distance-redshift, and look back
time-redshift for the model are presented. It has been shown that such models
are found to be compatible with the recent observations. This work has thus
generalized to higher dimensions the well-know result in four dimensional space
time. It is found that there may be significant difference in principle at
least,from the analogous situation in four dimensional space time.Comment: 11 pages, no figur
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