269 research outputs found
Advanced Modeling of Single Degree of Freedom System for Earthquake Ground Motion Using LabVIEW Software
In this paper, the structural responses at discrete time steps are evaluated to understand the linear dynamics characteristics of a structural system using LabVIEW (Laboratory Virtual Instrument Engineering Workbench) tool. Time History Analysis (THA) which is an essential procedure to design a reliable structure when the structure is subjected to dynamic loading is taken into consideration for the study. Direct integration method was used to find out the dynamic response of the structure as it is applicable for both linear as well as nonlinear range. Block diagram that perform step-by-step integration to analyze the linear single degree of freedom (SDOF) system has been prepared in LabVIEW. The processing of data is carried out till the equilibrium is satisfied at all discrete time points within the interval of solution instead of any time t. Different ground motion time histories were considered for THA and responses of the SDOF system are evaluated. The results from LabVIEW were validated and the accuracy of the algorithms generated are discussed. It is observed that the accuracy and stability of the final solution depends on the variation of displacement, velocity and acceleration that is assumed in each step. Thus, LabVIEW workbench can therefore be recognized as an effective instrument in structural engineering owing to its fast sampling features
Contact-Induced Nonlinearity in Oscillating Belts and Webs
This study is motivated by issues in belt dynamics and paper forming where the oscillatory motion of the contact point between the belt and pulley or the web and roll is important. The objective is to evaluate the influence of the nonlinear contact boundary conditions on the dynamics of the belt or web. To accomplish this objective, two models are analyzed using perturbation methods. The first model represents a string on an elastic foundation (an approximation of the paper forming process) and the second model represents a tensioned beam (accessory drive belt). The first correction to the fundamental natural frequency and the dynamic belt/web length are determined as a function of the governing parameters. For both models, the change in belt length is found to be proportional to the radius of the pulley/roll and the initial belt/web energy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69021/2/10.1177_107754639500100404.pd
Evaluación de la magnitud y peligro de la cosecha de corteza de especies vegetales medicinales en la región de Venda, Provincia de Limpopo, Sudáfrica
The medicinal flora of the Venda region consists of a
variety of species, which may potentially provide therapeutic agents
to treat different diseases. Bark use for medicinal purposes has been
reported for approximately 30% of the woody species (153 species)
in the Venda region in southern Africa. However, only 58 plant species
are commonly harvested for the medicinal properties in their
bark and found in muthi shops in the region. These 58 species were
scored for the possible threat of bark harvesting to the plant survival.
Ethnobotanical studies indicate that the growing trade in indigenous
medicinal plants in South Africa is posing a threat to the conservation
and preservation of many plant species. Apart from pharmaceutical
companies, trade in medicinal plants has become a way of
making a living for some people. This study investigated the pattern
of trade in medicinal plants by local markets in the Venda region,
Limpopo Province, South Africa. Indications are that bark harvesting
may threaten some of the plant species.La flora medicinal de la región de Venda consta de
una variedad de especies, que potencialmente pueden proporcionar
agentes terapéuticos para tratar diferentes enfermedades. El uso de
la corteza con propósitos medicinales se ha informado para aproximadamente
30% de las especies leñosas (153 especies) en el sur de
África, en la región de Venda. Sin embargo, sólo 58 especies vegetales
son cosechadas por las propiedades medicinales en su corteza, y vendidas
en tiendas muthi en la región. Estas 58 especies se clasificaron
por la posible amenaza de cosecha de su corteza, relacionado con
la supervivencia de las plantas. Estudios etnobotánicos indican que
el creciente comercio de plantas medicinales indígenas en Sudáfrica
está siendo una amenaza para la conservación y preservación de
muchas especies vegetales. Además de las compañías farmacéuticas,
el comercio de plantas medicinales se ha convertido en una forma
de vida para algunas personas. Este estudio investigó el patrón de
comercio de las plantas medicinales en los mercados locales en la
región de Venda, Provincia de Limpopo, Sudáfrica. Los resultados
indican que la cosecha de corteza puede amenazar algunas de las
especies vegetales.Muthi is a term for traditional medicine in southern Africa. It has been derived from the Zulu language word for “tree” due to the fact that most traditional medicines are derived
from trees.http://www.revistaphyton.fund-romuloraggio.org.aram201
The sensitivity of the Parkes Pulsar Timing Array to individual sources of gravitational waves
We present the sensitivity of the Parkes Pulsar Timing Array to gravitational waves (GWs) emitted by individual supermassive black hole binary systems in the early phases of coalescing at the cores of merged galaxies. Our analysis includes a detailed study of the effects of fitting a pulsar timing model to non-white timing residuals. Pulsar timing is sensitive at nanoHertz frequencies and hence complementary to Laser Interferometer Gravitational-Wave Observatory and Laser Interferometer Space Antenna. We place a sky-averaged constraint on the merger rate of nearby (z \u3c 0.6) black hole binaries in the early phases of coalescence with a chirp mass of 1010 M⊙ of less than one merger every 7 yr. The prospects for future GW astronomy of this type with the proposed Square Kilometre Array telescope are discussed. © 2010 The Authors. Journal compilation © 2010 RAS
Interdigital dermatitis, heel horn erosion, and digital dermatitis in 14 Norwegian dairy herds
AbstractThe aim of this study was to assess infectious foot diseases, including identification and characterization of Dichelobacter nodosus and Treponema spp., in herds having problems with interdigital dermatitis (ID) and heel horn erosion (E) and in control herds expected to have few problems. We also wanted to compare diseased and healthy cows in all herds. The study included 14 dairy herds with a total of 633 cows. Eight herds had a history of ID and E, and 6 were control herds. All cows were scored for lameness, and infectious foot diseases on the hind feet were recorded after trimming. Swabs and biopsies were taken from the skin of 10 cows in each herd for bacterial analyses. In total, samples were taken from 34 cows with ID, 11 with E, 40 with both ID and E, and 8 with digital dermatitis (DD), and from 47 cows with healthy feet. Swabs were analyzed for identification and characterization of D. nodosus by PCR, culture, virulence testing, and serotyping. Biopsies were analyzed by fluorescent in situ hybridization regarding histopathology, identification, and characterization of Treponema spp., and identification of D. nodosus. Interdigital dermatitis was the most frequent foot disease, with a prevalence of 50.4% in problem herds compared with 26.8% in control herds. Heel horn erosion was recorded in 34.8% of the cows in problem herds compared with 22.1% in control herds. Dichelobacter nodosus was detected in 97.1% of the cows with ID, in 36.4% with E, in all cows with both ID and E, in all cows with DD, and in 66.0% of cows with healthy feet. All serogroups of D. nodosus except F and M were detected, and all isolates were defined as benign by the gelatin gel test. Treponema spp. were detected in 50.0% of the cows with ID, in 9.1% with E, in 67.5% with ID and E, in all cows with DD, and in 6.4% of those with healthy feet. In total, 6 previously described phylotypes (PT) of Treponema were detected: PT1, PT3, PT6, PT13, and PT15 in cows with ID, PT1 in a cow with E, and PT1, PT2, PT3, PT6, and PT13 in cows with both ID and E. One new phylotype (PT19) was identified. The epidermal damage score was higher but the difference in inflammatory response of the dermis was minor in cows with ID versus those with healthy feet. Fisher’s exact test revealed an association between ID and D. nodosus, and between ID and Treponema spp. Logistic regression revealed an association between both ID and E and dirty claws (odds ratios=1.9 and 2.0, respectively). Our study indicates that D. nodosus, Treponema spp., and hygiene are involved in the pathogenesis of ID
Genetic variability in clones of 'Prata Anã' bananas based on phenotypic and molecular markers
Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV
Peer reviewe
Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV
Peer reviewe
Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV
Peer reviewe
Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search
Peer reviewe
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