1,753 research outputs found
Analytical approach of late-time evolution in a torsion cosmology
In this letter, we study the late-time evolution of a torsion cosmology only
with the spin- mode. We find three kinds of analytical solutions with a
constant affine scalar curvature. In the first case, it is not physical because
the matter density will be negative. In the second case, it shows that the dark
energy can be mimicked in the torsion cosmological model. In the third case,
the characteristic of late-time evolution is similar to that of the universe of
matter dominant. And we also find a kind of expression with the non-constant
curvature that the periodic character of numerical calculation is only the
reflection of solution in a specific period of evolution. Using these
expressions, we shall be able to predict the evolution over the late-time. From
this prediction, we know the fate of universe that the universe would expand
forever, slowly asymtotically to a halt.Comment: 12pages,6 figure
Disease universe: Visualisation of population-wide disease-wide associations
We apply a force-directed spring embedding graph layout approach to
electronic health records in order to visualise population-wide associations
between human disorders as presented in an individual biological organism. The
introduced visualisation is implemented on the basis of the Google maps
platform and can be found at http://disease-map.net . We argue that the
suggested method of visualisation can both validate already known specifics of
associations between disorders and identify novel never noticed association
patterns.Comment: 4 pages (2 pics) the main paper + 8 pages (3 pics) Supplementary
Material
Threshold of photoelectron emission from CNx films deposited at room temperature and at 500 °C
The threshold of photoelectron emission was measured for amorphous CNx films deposited at room temperature (RT) and at 500 °C. The x values of the films deposited at RT and at 500 °C by magnetron sputtering of a graphite target in a mixed N2/Ar gas were 0.6 and 0.3, respectively. Ratios of the sp2- to sp3-hybridized components of both C and N for the film deposited at 500 °C were larger by 4 times than those for the film deposited at RT. The onsets of the electron emission by photon irradiation were 5.0 and 4.7 eV for the films deposited at RT and at 500 °C, respectively
Studies or Leisure? : a Cross-cultural Comparison of Taiwanese and Norwegian Engineering Students' Preferences for University Life
An insight into students' preferences and expectations of life at university is useful when trying to
understand drop-out percentages and design study programs, especially in the global competition
for students. This study focuses on Taiwanese and Norwegian students' preferences for life and
activities at university. Hofstede's model was used to predict culture-related differences. A pairwise
decision questionnaire was used to conduct measurements. A universal trend is that teamwork
was considered most important, and teachers were considered to be less important. The most
noticeable culture differences were that Taiwanese students preferred non-curricular values and
Norwegian students preferred curricular values. The study discipline had little impact on students'
preferences
Towards harmonious East-West educational partnerships: a study of cultural differences between Taiwanese and Norwegian engineering students
The collaboration activities between educational
institutions in the East and the West are on the
increase as an increasingly globalized economy requires
graduates to have the skills to work across cultural divides.
Such collaborations are difficult and require patience. One
challenge is that students or teachers may have misconceptions
about aspects of the other culture that may cause
problems. This study sets out to identify what values students
in typical Eastern and Western societies associate
with a good student, good student behavior, good teachers
and good lectures with the purpose to identify discrepancies.
This study is based on the results of a pair-wise
ranking questionnaire completed by 233 Taiwanese and
Norwegian students of both engineering and non-technical
subjects. The results confirm some established beliefs
regarding culturally related differences. However, several
issues were found to be culturally neutral, and cultural
differences were identified for several issues that were
predicted to be culturally neutral. The results of this study
may be useful to educators involved in East–West
internationalization
Preparation And Characterization Of Water-Soluble Chitosan Gel For Skin Hydration.
Kitosan, biopoliaminosakarida secara linear dan semulajadi, telah mendapat banyak perhatian sebagai bio-polimer berfungsi dengan aplikasi dalam bidang farmaseutikal, makanan, kosmetik dan perubatan.
Chitosan, a natural and linear biopolyaminosaccharide, has received much attention as a functional biopolymer with applications in pharmaceuticals, food, cosmetics and medicines. Nevertheless, chitosan application is limited by its solubility in aqueous solution
Observation of coherent many-body Rabi oscillations
A two-level quantum system coherently driven by a resonant electromagnetic
field oscillates sinusoidally between the two levels at frequency
which is proportional to the field amplitude [1]. This phenomenon, known as the
Rabi oscillation, has been at the heart of atomic, molecular and optical
physics since the seminal work of its namesake and coauthors [2]. Notably, Rabi
oscillations in isolated single atoms or dilute gases form the basis for
metrological applications such as atomic clocks and precision measurements of
physical constants [3]. Both inhomogeneous distribution of coupling strength to
the field and interactions between individual atoms reduce the visibility of
the oscillation and may even suppress it completely. A remarkable
transformation takes place in the limit where only a single excitation can be
present in the sample due to either initial conditions or atomic interactions:
there arises a collective, many-body Rabi oscillation at a frequency
involving all N >> 1 atoms in the sample [4]. This is true even
for inhomogeneous atom-field coupling distributions, where single-atom Rabi
oscillations may be invisible. When one of the two levels is a strongly
interacting Rydberg level, many-body Rabi oscillations emerge as a consequence
of the Rydberg excitation blockade. Lukin and coauthors outlined an approach to
quantum information processing based on this effect [5]. Here we report initial
observations of coherent many-body Rabi oscillations between the ground level
and a Rydberg level using several hundred cold rubidium atoms. The strongly
pronounced oscillations indicate a nearly complete excitation blockade of the
entire mesoscopic ensemble by a single excited atom. The results pave the way
towards quantum computation and simulation using ensembles of atoms
Comparative Cytotoxicity of Glycyrrhiza glabra Roots from Different Geographical Origins Against Immortal Human Keratinocyte (HaCaT), Lung Adenocarcinoma (A549) and Liver Carcinoma (HepG2) Cells
Glycyrrhiza glabra L. (Fabaceae), commonly known as 'liquorice', is a well-known medicinal plant. Roots of this plant have long been used as a sweetening and flavouring agent in food and pharmaceutical products, and also as a traditional remedy for cough, upper and lower respiratory ailments, kidney stones, hepatitis C, skin disorder, cardiovascular diseases, diabetes, gastrointestinal ulcers and stomach ache. Previous pharmacological and clinical studies have revealed its antitussive, antiinflammatory, antiviral, antimicrobial, antioxidant, immunomodulatory, hepatoprotective and cardioprotective properties. While glycyrrhizin, a sweet-tasting triterpene saponin, is the principal bioactive compound, several bioactive flavonoids and isoflavonoids are also present in the roots of this plant. In the present study, the cytotoxicity of the methanol extracts of nine samples of the roots of G.-glabra, collected from various geographical origins, was assessed against immortal human keratinocyte (HaCaT), lung adenocarcinoma (A549) and liver carcinoma (HepG2) cell lines using the in vitro 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide cell toxicity/viability assay. Considerable variations in levels of cytotoxicity were observed among various samples of G.-glabra
- …
