8,523 research outputs found
Office quality classification theoretical and empirical issues
Office quality classification literature recognises identification of office classes through division of office market rent distribution into intervals but failed to provide sound theoretical framework and comprehensive empirical approach to this method. This paper theorised that as office rental levels are a function of office quality; high quality office classes should have their mean rents greater than average market rent and mean rents of low quality classes. Also that heterogeneous nature of property coupled with lack of perfect information to market participants could result into differential evaluation of rent and quality of the same property by different market participants. The behaviour of participants normally reflects in distribution of market rent by depicting natural breaks in the distribution that could be captured by univariate data exploration. Frequency and histograms of rent distributions that were assumed to depict the behaviour of market participants were used to divide rent distribution to intervals to identify office quality classes. The results of this classification were validated by discriminant analysis. 67% and 59% accuracies were achieved for estimation and holdout subsamples respectively. This paper extended theoretical and empirical approaches in office quality classification. The proposed empirical approach could be used in future classification research
Comparing government regulated and unregulated inland water fisheries of Plateau State, Nigeria: an economic productivity analysis
The objectives of the research was to compares the economics of regulated and unregulated fisheries through the estimates of technical, allocative and economic efficiency of micro entrepreneur or artisanal fishers in the central Nigerian state of Plateau, with a view to examine the economic benefits and sustainability on inland water fisheries as renewable resource in developing economics. Stochastic frontier production and cost functions using the maximum likelihood estimation (MLE) technique was used to analysed data collected from, daily fishing observations made for 4 weeks, and through questionnaire from 20 micro entrepreneurs from unregulated lakes of Polmakat, Shimankar, Deben, Janta and 30 micro entrepreneurs from the only regulated Pandam Lake to give a sample size of 110 respondents selected in a multi-stage sampling technique. The mean technical, allocative and economic efficiency of unregulated fishers were 0.83, 0.56 and 0.68 respectively, while, the mean technical, allocative and economic efficiencies of the regulated fishers were 0.91, 0.68 and 0.72 respectively. This study shows higher potential for increase in fishing output at unregulated fisheries through better use of available resources, given the current state of technology. The MLE result suggested that extension contact, age and educational status were major determinants of efficiency in unregulated fishing, meaning that the transformation for effective and sustainable fisheries exploitation requires the involvement of educated fishers, extension education, and redefinition of property rights of unregulated fishery and constraining of inputs at regulated fishery. Keywords: micro entrepreneurs, economic, efficiency, comparative, stochastic, renewable resourc
Finite Element Analysis and Statistical Method to Determine Temperature Distribution on Cutting Tool in End-Milling
The aim of this study is to determine the temperature distribution on cutting tool when machining HASTELLOY C-22HS with carbide coated cutting tool. Response Surface Method (RSM) used to minimize the number of experiments and to develop first order temperature model. Finite element analysis (FEA) was used to verification of the
temperature distribution on cutting tool. From FEA results show clearly that the relationship between the variables (cutting speed, feed rate and axial depth) with responses (temperature). From the first order model shows that cutting speed, feed rate and axial depth plays important role in producing cutting temperature. The feed rate has the most dominant parameter on the temperature, followed by the axial depth and cutting speed. The
results from FEA were compared with the experimental values. The predicted values are quite close to the experimental results, even though its accuracy is slightly inferior as Finite Element Analysis and Statistical Method to Determine Temperature Distribution on Cutting Tool in End-Milling 452 compared to RSM. However, FEA is able to produce the temperature distribution around the cutting tool, in great detail
Rhein: A Review of Pharmacological Activities
Rhein (4, 5-dihydroxyanthraquinone-2-carboxylic acid) is a lipophilic anthraquinone extensively found in medicinal herbs, such as Rheum palmatum L., Cassia tora L., Polygonum multiflorum Thunb., and Aloe barbadensis Miller, which have been used medicinally inChina formore than 1,000 years. Its biological activities related to human health are being explored actively. Emerging evidence suggests that rhein has many pharmacological effects, including hepatoprotective, nephroprotective, anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. The present review provides a comprehensive summary and analysis of the pharmacological properties of rhein, supporting the potential uses of rhein as a medicinal agent
A Theoretical Construction of Thin Shell Wormhole from Tidal Charged Black hole
Recently, Dadhich et al [ Phys.Lett.B 487, 1 (2000)] have discovered a black
hole solution localized on a three brane in five dimensional gravity in the
Randall-Sundrum scenario. In this article, we develop a new class of thin shell
wormhole by surgically grafting above two black hole spacetimes. Various
aspects of this thin wormhole are also analyzed.Comment: 14 pages, 6 figures, Accepted in Gen.Rel.Gra
Static circularly symmetric perfect fluid solutions with an exterior BTZ metric
In this work we study static perfect fluid stars in 2+1 dimensions with an
exterior BTZ spacetime. We found the general expression for the metric
coefficients as a function of the density and pressure of the fluid. We found
the conditions to have regularity at the origin throughout the analysis of a
set of linearly independent invariants. We also obtain an exact solution of the
Einstein equations, with the corresponding equation of state , which
is regular at the origin.Comment: 10 pages, 1 figure, revtex 4. This paper is in honor of Alberto
Garcia's sixtieth birthday. Accepted by Gen. Rel. Gra
A new algorithm for anisotropic solutions
We establish a new algorithm that generates a new solution to the Einstein
field equations, with an anisotropic matter distribution, from a seed isotropic
solution. The new solution is expressed in terms of integrals of an isotropic
gravitational potential; and the integration can be completed exactly for
particular isotropic seed metrics. A good feature of our approach is that the
anisotropic solutions necessarily have an isotropic limit. We find two examples
of anisotropic solutions which generalise the isothermal sphere and the
Schwarzschild interior sphere. Both examples are expressed in closed form
involving elementary functions only.Comment: 16 pages, to appear in Pramana - J. Phy
First principles calculations of the electronic and geometric structure of nanoalloy
\emph{Ab initio} calculations of the structure and electronic density of
states (DOS) of the perfect core-shell nanoalloy attest to its
symmetry and confirm that it has only 6 non-equivalent (2 and 4
) atoms. Analysis of bond-length, average formation energy, heat of
formation of and alloys provide an explanation
for the relative stability of the former with respect to the other nanoalloys
in the same family. The HOMO-LUMO gap is found to be 0.77 eV, in agreement with
previous results. Analysis of the DOS of , alloys
and related systems provides insight into the effects of low coordination,
contraction/expansion and the presence of foreign atoms on the DOS of and
. While some characteristics of the DOS are reminiscent of those of the
phonon-stable alloys, the and states hybridize
significantly in , compensating the -band narrowing that each
atom undergoes and hindering the dip in the DOS found in the bulk alloys.
Charge density plots of provide further insights into the
relative strengths of the various interatomic bonds. Our results for the
electronic and geometric structure of this nanoalloy can be explained in terms
of length and strength hierarchies of the bonds, which may have implications
also for the stability of alloy in any phase or size.Comment: 16 figure
ANALGESIC, ANTI-INFLAMMATORY AND ANTIPYRETIC ACTIVITIES OF THE AQUEOUS EXTRACT OF GERANIUM CAROLINIANUM L
Background: Geranium carolinianum L. (Geraniaceae) is widely used for a variety of diseases including herpetic keratitis, eczema, rheumatalgia etc. However, there is lack of relevant scientific research.
Materials and Methods: GCE (125, 250, 500mg/kg body weight) was evaluated for its pharmacological properties by using the acetic acid-induced writhing test, the hot plate test and the fresh egg white-induced paw edema in rats. The dimethylbenzene-induced mouse inflammation model and the lipopolysaccharide (LPS)-induced rat fever model were employed and the acute toxicity of GCE was also assessed.
Results: The Geranium carolinianum aqueous extract (GCE) significantly inhibited the writhing responses in mice, increased reaction time of mice in the hot plate test, and suppressed the fresh egg white-induced paw edema in rats and the dimethylbenzene-induced ear edema in mice whilst attenuating LPS-induced fever in rats in a dose dependent manner. Furthermore, no deaths were observed when mice were orally administered GCE up to 14 g/kg body weight (approximately 553times of clinical dose).
Conclusions: GCE possesses analgesic, anti-inflammatory and antipyretic activities and is non-toxic at the doses used. The results of this study support the clinical use and effectiveness of Geranium carolinianum as an analgesic, anti-inflammatory and antipyretic agent in folk medicine.
Key words: Plant drug; Pain; Inflammation; Pyrexia; Toxicity; Anima
Causal Bulk Viscous Dissipative Isotropic Cosmologies with Variable Gravitational and Cosmological Constants
We consider the evolution of a flat Friedmann-Robertson-Walker Universe,
filled with a causal bulk viscous cosmological fluid, in the presence of
variable gravitational and cosmological constants. The basic equation for the
Hubble parameter, generalizing the evolution equation in the case of constant
gravitational coupling and cosmological term, is derived, under the
supplementary assumption that the total energy of the Universe is conserved. By
assuming that the cosmological constant is proportional to the square of the
Hubble parameter and a power law dependence of the bulk viscosity coefficient,
temperature and relaxation time on the energy density of the cosmological
fluid, two classes of exact solutions of the field equations are obtained. In
the first class of solutions the Universe ends in an inflationary era, while in
the second class of solutions the expansion of the Universe is non-inflationary
for all times. In both models the cosmological "constant" is a decreasing
function of time, while the gravitational "constant" increases in the early
period of evolution of the Universe, tending in the large time limit to a
constant value.Comment: 14 pages, 15 figure
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