Effect of Rocker Length on the Dynamic Behavior of a Coupler Link in Four Bar Planar Mechanism

AbstractIt is well-known that the dynamic analysis of mechanisms operating at high speed cannot neglect the effects of link elastic flexibility. In fact this effect may affect the dynamic response of the output link motion, so that the mechanisms may fail to perform their assign tasks effectively. The dynamic analysis of high speed mechanism having rigid rocker length is carried out by using Finite Element Method (FEM) and the same is discussed in the present work. Moreover, the behavior of damped-flexible coupler under varying length of rigid rocker length is analyzed. Modeling and simulation of mechanism has been analyzed by using ANSYS and results are found to be in agreement with the experimental result mention in literature. It is observed that increase in length of rocker link gives rise in the strain value in middle of the coupler link and hence the length of rocker link should be kept as minimum as possible

Extra-dimensional cosmology with domain-wall branes

We show how to define a consistent braneworld cosmology in a model in which the brane is constructed as a field-theoretic domain wall of finite thickness. The Friedmann, Robertson-Walker metric is recovered in the region of the brane, but, remarkably, with scale factor that depends on particle energy and on particle species, constituting a breakdown of the weak equivalence principle on sufficiently small scales. This unusual effect comes from the extended nature of particles confined to a domain-wall brane, and the fact that they feel an "average" of the bulk spacetime. We demonstrate how to recover the standard results of brane cosmology in the infinitely-thin brane limit, and comment on how our results have the potential to place bounds on parameters such as the thickness of domain-wall braneworlds.Comment: 23 pages; v2 has additional references and reflects journal versio

Evidence for a Binary Companion to the Central Compact Object 1E 1207.4-5209

Unique among neutron stars, 1E 1207.4-5209 is an X-ray pulsar with a spin period of 424 ms that contains at least two strong absorption features in its energy spectrum. This neutron star has been identified as a member of the radio-quiet compact central objects in supernova remnants. It has been found that 1E 1207.4-5209 is not spinning down monotonically suggesting that this neutron star undergoes strong, frequent glitches, contains a fall-back disk, or possess a binary companion. Here, we report on a sequence of seven XMM-Newton observations of 1E 1207.4-5209 performed during a 40 day window in June/July 2005. Due to unanticipated variance in the phase measurements beyond the statistical uncertainties, we could not identify a unique phase-coherent timing solution. The three most probable timing solutions give frequency time derivatives of +0.9, -2.6, and +1.6 X 10^(-12) Hz/s (listed in descending order of significance). We conclude that the local frequency derivative during our XMM-Newton observing campaign differs from the long-term spin-down rate by more than an order of magnitude, effectively ruling out glitch models for 1E 1207.4-5209. If the long-term spin frequency variations are caused by timing noise, the strength of the timing noise in 1E 1207.4-5209 is much stronger than in other pulsars with similar period derivatives. Therefore, it is highly unlikely that the spin variations are caused by the same physical process that causes timing noise in other isolated pulsars. The most plausible scenario for the observed spin irregularities is the presence of a binary companion to 1E 1207.4-5209. We identified a family of orbital solutions that are consistent with our phase-connected timing solution, archival frequency measurements, and constraints on the companions mass imposed by deep IR and optical observations.Comment: 8 pages, 4 figures. To be published in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface" (April 24-28, 2006) - eds. D. Page, R. Turolla & S. Zan

Baffin Island Fjord Macrobenthos: Bottom Communities and Environmental Significance

Cluster analysis of the benthos from ten Baffin Island fjords defines six faunal associations. The macrotidal Sunneshine Fiord has a shallow kelp-related Isopod Association. Cambridge Fiord supports a shallow Onuphid Association controlled by gravel from dropstones. A widespread Portlandia Association typified the shallow zones of more recently glaciated fjords where sedimentation rates are high. An Ophiuroid-Anemone Association was defined from current-affected submarine channel environments. A Maldanid Association covered the greatest area in all fjords and passed into an Elasipod Association in the deepest water in Cambridge Fiord. Fjord-head faunas are used to model ecological changes accompanying glacier retreat, from monospecific Portlandia, through mature Portlandia Association to Onuphid Association accompanied by diverse filter feeders and herbivores. Chlamys islandica was found living in Cambridge Fiord, which substantially increases its northern limit.Key words: macrobenthos, Arctic, cluster analysis, bivalve, Quaternary, sedimentMots clés: macrobenthos, Arctique, analyse d’ensemble, bivalve, quaternaire, sédiment

The staggered domain wall fermion method

A different lattice fermion method is introduced. Staggered domain wall fermions are defined in 2n+1 dimensions and describe 2^n flavors of light lattice fermions with exact U(1) x U(1) chiral symmetry in 2n dimensions. As the size of the extra dimension becomes large, 2^n chiral flavors with the same chiral charge are expected to be localized on each boundary and the full SU(2^n) x SU(2^n) flavor chiral symmetry is expected to be recovered. SDWF give a different perspective into the inherent flavor mixing of lattice fermions and by design present an advantage for numerical simulations of lattice QCD thermodynamics. The chiral and topological index properties of the SDWF Dirac operator are investigated. And, there is a surprise ending...Comment: revtex4, 7 figures, minor revisions, 2 references adde

Evaluation of the use of moist potential vorticity and moist potential vorticity vector in describing annual cycles of rainfall over different regions in Tanzania

Please read abstract in the article.http://www.frontiersin.org/Earth_Scienceam2017Geography, Geoinformatics and Meteorolog

Evaluation of the use of moist potential vorticity and moist potential vorticity vector in describing annual cycles of rainfall over different regions in Tanzania

Please read abstract in the article.http://www.frontiersin.org/Earth_Scienceam2017Geography, Geoinformatics and Meteorolog

High-pressure, non compliant balloon angioplasty for long and calcified infrapopliteal and inframalleolar lesions is feasible

Background: To evaluate the safety, feasibility and effectiveness of high-pressure, noncompliant balloon angioplasty in the management of long infrapopliteal calcified lesions. Methods: Consecutive patients, presenting with chronic limb-threatening ischemia (CLTI) and long (>100 mm) calcified infrapopliteal lesions who were treated with a high pressure, noncompliant balloon (JADE, OrbusNeich, Hong Kong) between January 2016 and July 2016 were retrospectively analyzed. Angioplasty was performed by inflating the balloon to a pressure of 22 to 24 atm for 90 seconds. Primary outcome was technical success. Secondary outcomes were procedure-related complications, limb salvage, amputation-free survival (AFS), wound healing, overall survival, freedom from clinically driven target lesion reintervention (CD-TLR), and resolution of CLTI at 2 and 3 years. Results: Overall, 23 lesions in 21 limbs of 20 patients were treated. All patients had tissue loss (Rutherford 5 or 6). The mean lesion length was 374.8 mm. Of all lesions, 56.5% were occlusions, 91.3% were classified as TransAtlantic Inter-Society Consensus (TASC) C and D lesions, and 78.3% had severe calcification classification. Of all lesions, 52.2% extended into the below-the-ankle arteries. Technical success was achieved in 22 lesions (95.7%). There were no procedure-related complications. No bailout stenting was required. At 2 and 3 years, limb salvage was 84.7% and 78.7%, AFS was 71.4% and 56.1%, wound healing was 81.0% and 85.7%, overall survival was 75.0% and 64.3% and freedom from CD-TLR was 77.6% and 63.5%, respectively. Resolution of CLTI without TLR was 81.0% at 2 and 3 years. Conclusions: This study is the first to analyze safety and feasibility of a high-pressure, noncompliant balloon for long, calcified infrapopliteal and inframalleolar lesions

Homogeneous nucleation of a non-critical phase near a continuous phase transition

Homogeneous nucleation of a new phase near a second, continuous, transition, is considered. The continuous transition is in the metastable region associated with the first-order phase transition, one of whose coexisting phases is nucleating. Mean-field calculations show that as the continuous transition is approached, the size of the nucleus varies as the response function of the order parameter of the continuous transition. This response function diverges at the continuous transition, as does the temperature derivative of the free energy barrier to nucleation. This rapid drop of the barrier as the continuous transition is approached means that the continuous transition acts to reduce the barrier to nucleation at the first-order transition. This may be useful in the crystallisation of globular proteins.Comment: 6 pages, 1 figur

Assessment of the impacts of climate change on maize production in the Wami Ruvu basin of Tanzania

The IPCC assessment reports confirm that climate change will hit developing countries the hardest. Adaption is on the agenda of many countries around the world. However, before devising adaption strategies, it is crucial to assess and understand the impacts of climate change at regional and local scales. In this study, the impact of climate change on rain-fed maize (Zea mays) production in the Wami-Ruvu basin of Tanzania is assessed using process based crop model the Decision Support System for Agro-technological Transfer (DSSAT). The model was calibrated using detailed field and household survey information of (crop yields, soil and management data inputs). Daily minimum and maximum temperatures, rainfall and solar radiation for current climate condition (1971-2000) as well as future climate projections (2010-2039), (2040-2069) and (2070-2099) for two Representative Concentration Path ways (RCPs): RCP45 and RCP85 scenarios were used to drive the crop model. These data are derived from three high-resolution regional climate models (RCMs), used in the Coordinated Regional Climate Downscaling Experiment program (CORDEX). Impact of climate change on maize production is assessed by analyzing the changes in simulated maize yields for the period 2010-2039, 2040-2069 and 2070-2099 relative to baseline period 1971-2000. Projection results from different models showed that due to climate change, the length of growing season and future maize yields over Wami-Ruvu basin will decrease under both RCP4.5 and RCP8.5 at the current, mid and end of the centuries. However, the projected yields estimates and the length of growing season differ from model to model highlighting the uncertainties associated with the projections. Climate data from the ensemble average of five model members was constructed to address the issue of uncertainties from individual climate models and used to drive DSSAT. Results showed that due to climate change future maize yields over Wami-Ruvu basin will slightly increase relative to the baseline during current century under RCP 4.5 and RCP 8.5. Meanwhile, maize yields will decline in the mid and end centuries. The spatial distribution shows that more decline in maize yields are projected over lower altitude regions due to projected increase in temperatures and decreased rainfall in those areas. The eastern part of the basin will feature more decrease in maize yields, while central parts of the basin and the western side of the basin will experience increase in maize yields during current, mid and end centuries under RCP 4.5 and RCP 8.5. The main reason for decrease and increase maize yields is the projected increase in temperatures that will reduce the length of growing seasons and hence affecting maize productivity. It is therefore recommended that appropriate and adequate adaptation strategies need to be designed to help the communities adapt to the projected decrease in maize production.http://jwcc.iwaponline.com2017-06-30hb2017Geography, Geoinformatics and Meteorolog