225 research outputs found
Study of the resistance offered by propellers rotating on an airstream
This report presents a series of tests conducted to verify the formula for thrust P = q(exp 2) D(exp 2) V(exp 2), where P represents thrust, V the velocity of the airstream, D the diameter of the propeller, and q the lifting quality of a comparative propeller which is called the conjugate propeller
Canning of non exportable shrimps
The shrimp can with three compounds of salted water, oil, and sauce, in view of the organoleptic characteristics were compared to each other. Also the effects of processing methods including freezing, drying and canning were evaluated according to some qualitative parameters to raw shrimp (blank). The result showed that considering the organoleptic characteristics, the shrimp can with the compound of oil was better than the two others. On the other hand, the pH of the shrimp can, containing oil was 7.44 ± 0.01, freeze shrimp 7 ± 83-0.04 and dried shrimp 7.46 ± 0.01, that according to the T test, comparing to the blank these differences were statistically meaningful (P <U/01). The amount of protein in freeze shrimp was 96.2 ± 0.03, in dried shrimp 81 ± 0.7 and in canned shrimp (containing oil) was 76.8 ± 0.92, these differences were also statistically considerable. The quantity of the T.V.N in freeze shrimp was 0 ± 0.53, dried shrimp 66 ± 0.3 and in canned shrimp (containing oil) was significant. In view of the total number of the microorganisms, in freeze shrimp was 4800 per gram, in the dried shrimp 15500 per gram, and in the canned shrimp was negative
Nanoscale buckling deformation in layered copolymer materials
In layered materials, a common mode of deformation involves buckling of the
layers under tensile deformation in the direction perpendicular to the layers.
The instability mechanism, which operates in elastic materials from geological
to nanometer scales, involves the elastic contrast between different layers. In
a regular stacking of "hard" and "soft" layers, the tensile stress is first
accommodated by a large deformation of the soft layers. The inhibited Poisson
contraction results in a compressive stress in the direction transverse to the
tensile deformation axis. The hard layers sustain this transverse compression
until buckling takes place and results in an undulated structure. Using
molecular simulations, we demonstrate this scenario for a material made of
triblock copolymers. The buckling deformation is observed to take place at the
nanoscale, at a wavelength that depends on strain rate. In contrast to what is
commonly assumed, the wavelength of the undulation is not determined by defects
in the microstructure. Rather, it results from kinetic effects, with a
competition between the rate of strain and the growth rate of the instability.
http://www.pnas.org/content/early/2011/12/23/1111367109.abstrac
Grameen Model and its ethical inclinations to Islamic Microfinance System: A Narrative-Textual Case Study
This study focuses on an in-depth literature review to understand the Islamic microfinance as a system and grameen model as a concept all embedded in ethical concern for shared values. The concept of Grameen model and its ethical behavior have come to the fore in recent years in both developed and developing countries as a result of growing sense of corporate wrongdoing. The paper addresses the Grameen model and its ethical relevance to the benefits and success of Islamic microfinance in modern economy
Electronic structure of triangular, hexagonal and round graphene flakes near the Fermi level
The electronic shell structure of triangular, hexagonal and round graphene
quantum dots (flakes) near the Fermi level has been studied using a
tight-binding method. The results show that close to the Fermi level the shell
structure of a triangular flake is that of free massless particles, and that
triangles with an armchair edge show an additional sequence of levels ("ghost
states"). These levels result from the graphene band structure and the plane
wave solution of the wave equation, and they are absent for triangles with an
zigzag edge. All zigzag triangles exhibit a prominent edge state at the Fermi
level, and few low-energy conduction electron states occur both in triangular
and hexagonal flakes due to symmetry reasons. Armchair triangles can be used as
building blocks for other types of flakes that support the ghost states. Edge
roughness has only a small effect on the level structure of the triangular
flakes, but the effect is considerably enhanced in the other types of flakes.
In round flakes, the states near the Fermi level depend strongly on the flake
radius, and they are always localized on the zigzag parts of the edge
MicroRNA profile changes in human immunodeficiency virus type 1 (HIV-1) seropositive individuals
MicroRNAs (miRNAs) play diverse roles in regulating cellular and developmental functions. We have profiled the miRNA expression in peripheral blood mononuclear cells from 36 HIV-1 seropositive individuals and 12 normal controls. The HIV-1-positive individuals were categorized operationally into four classes based on their CD4+ T-cell counts and their viral loads. We report that specific miRNA signatures can be observed for each of the four classes
Effect of Monitoring Trap and Mating Disruption Dispenser Application Heights on Captures of Male Grapholita molesta (Busck; Lepidoptera: Tortricidae) in Pheromone and Virgin Female-Baited Traps
ABSTRACT Studies were conducted in 0.07-to 0.18-ha peach and apple plots to determine the effects of pheromone trap and hand-applied emulsiÞed wax pheromone dispenser application heights on captures of Grapholita molesta in traps baited with pheromone lures or virgin females. Traps and pheromone dispensers were placed either low (1.2Ð1.8 m) or high (2.7Ð 4 m) within tree canopies. In the majority of cases, equivalent numbers of male G. molesta were caught in traps placed at the low and high positions in both pheromone-treated and untreated plots. Furthermore, pheromone dispensers placed at the low and high positions equally disrupted orientation of male G. molesta to pheromone traps placed at either height and to virgin female traps placed at 1.2Ð1.8 m within canopies season-long at most sites. Our results indicate that for trees Յ3.5 m tall, dispensers with release rates Ն18 mg/ha/h placed at 1.5Ð2.0 m (heights easily reached from the ground) should effectively disrupt mating of G. molesta throughout tree canopies. In trees between 3.5 and 4.5 m tall, the dispensers should be moved to Ϸ1.5 m from the top of the canopy. For trees taller than 4.5 m, we recommend hanging dispensers both in the top and bottom thirds of tree canopies. Most commercial Michigan peach and apple trees are Ͻ3.5 m tall. Eliminating the need to apply dispensers high in the canopy in most orchards will enable growers to reduce application costs, thereby facilitating increased adoption of mating disruption for G. molesta control by growers
On the Mass Spectrum of the SU(2) Higgs Model in 2+1 Dimensions
We calculate the masses of the low-lying states with quantum numbers
in the Higgs and confinement regions of the
three-dimensional SU(2) Higgs model, which plays an important r\^ole in the
description of the thermodynamic properties of the standard model at finite
temperatures. We extract the masses from correlation functions of
gauge-invariant operators which are calculated by means of a lattice Monte
Carlo simulation. The projection properties of our lattice operators onto the
lowest states are greatly improved by the use of smearing techniques. We also
consider cross correlations between various operators with the same quantum
numbers. From these the mass eigenstates are determined by means of a
variational calculation. In the symmetric phase, we find that some of the
ground state masses are about 30\% lighter than those reported from previous
simulations. We also obtain the masses of the first few excited states in the
symmetric phase. Remarkable among these is the occurrence of a state
composed almost entirely of gauge degrees of freedom. The mass of this state,
as well as that of its first excitations, is nearly identical to the
corresponding glueball states in three-dimensional SU(2) pure gauge theory,
indicating an approximate decoupling of the pure gauge sector from the Higgs
sector of the model. We perform a detailed study of finite size effects and
extrapolate the lattice mass spectrum to the continuum.Comment: 30 pages LATEX, uses epsf.st
3d SU(N) + adjoint Higgs theory and finite temperature QCD
We study to what extent the three-dimensional SU(N)+adjoint Higgs theory can
be used as an effective theory for finite temperature SU(N) gauge theory, with
N=2,3. The parameters of the 3d theory are computed in 2-loop perturbation
theory in terms of T/Lambda_MSbar,N,N_f. The perturbative effective potential
of the 3d theory is computed to two loops for N=2. While the Z(N) symmetry
probably driving the 4d confinement-deconfinement phase transition (for N_f=0)
is not explicit in the effective Lagrangian, it is partly reinstated by
radiative effects in the 3d theory. Lattice simulations in the 3d theory are
carried out for N=2, and the static screening masses relevant for the
high-temperature phase of the 4d theory are measured. In particular, we measure
non-perturbatively the O(g^2 T) correction to the Debye screening mass. We find
that non-perturbative effects are much larger in the SU(2) + adjoint Higgs
theory than in the SU(2) + fundamental Higgs theory.Comment: 30 pages, 9 figure
- …