Hydrodynamic Performance and Acoustic Response of Ship Propeller

The aim of the paper is to predict the hydrodynamic performance and noise generated by the propeller at different advance ratio and the speed of the propeller. Three bladed, DTMB 4119 propeller model was created using the NACA66 modified line, a = 0.8 hydrofoil profile. ANSYS Workbench software is used for mesh generation and computational analysis. A large-eddy simulation turbulence model and Ffowcs Williams-Hawkings (FWH) acoustic model is used for all simulations. A moving reference frame is used to simulate the rotational effects of the propeller. The speed of the propeller is 792 rpm, the propeller being 0.2 m, and inlet velocity is varied to study the effect of the advance ratio. A transient analysis is carried out using a time step value of 0.0005 seconds and the total simulation time is 0.6 seconds. The hydrodynamic performance parameters are validated by comparing with the experimental data available in the literature. The sound pressure level (SPL) is plotted over the frequency range of 0 to 1000 Hz at different locations, speed, and an advance ratio of 0.5, 0.7, 0.833, and 0.9,1. The structural, acoustic and hydrodynamic behaviour of the propeller was predicted using a two-way fluid structure interaction at an advance ratio of 0.833. The major conclusions drawn from the analysis are that the sound pressure level values are increased at the propeller off-design conditions and varying with the receiver locations. The data generated from this study is useful for the designers to carry out further research in order to reduce the noise generated from the propeller

Population-based cross-sectional study of barriers to utilisation of refraction services in South India: Rapid Assessment of Refractive Errors (RARE) Study

AIM: To assess the barriers to the uptake of refraction services in the age group of 15-49 years in rural Andhra Pradesh, India. METHODS: A population-based cross-sectional study was conducted using cluster random sampling to enumerate 3300 individuals from 55 clusters. A validated questionnaire was used to elicit information on barriers to utilisation of services among individuals with uncorrected refractive error (presenting visual acuity 35 years with binocular distance visual acuity of ≥6/12). RESULTS: 3095 (94%) were available for examination. Those with uncorrected refractive errors cited affordability as the main barrier to the uptake of eye-care services. Among people with uncorrected presbyopia, lack of 'felt need' was the leading barrier. CONCLUSION: The barriers that were 'relatively easy to change' were reported by those with uncorrected refractive errors in contrast to 'difficult to change' barriers reported by those with uncorrected presbyopia. Together, the data on prevalence and an understanding of the barriers for the uptake of services are critical to the planning of refractive error services

Simple synthetic protocols for tertiary alkyl and allyl thiols

1169-117

Antinociceptive and anti-Inflammatory effects of the standardized oil of Indian Callistemon lanceolatus leaves in experimental animals

The effect of Callistemon lanceolatus (Syn. C. citrinus curtis; Family: Myrtaceae) leaf oil was studied for the antinociceptive and anti-inflammatory activity in experimental animals. C. lanceolatus, 25 – 100 mg/kg administered orally for 3 days exhibited graded dose response equivalent to 21.95% - 89.90% protection in the tail flick latent test in rat. The C. lanceolatus oil (50 and 100 mg/kg, given orally for 3 days) was effective in hot plate reaction time (64.05% and 112.97%,

YAGI UDA SHAPED DUAL RECONFIGURABLE ANTENNA

In this paper, YagiUda shaped rectangular microstrip patch antenna fed by inset feed is designed to operate for frequency and polarization reconfigurability is presented. It consists of a square patch with four corners truncated and three parasitic patches placed on top. It operates as a frequency and polarization, reconfigurable antenna. Switches are placed in the gaps of truncated corners to obtain switching between Linear, Circular polarizations. The proposed antenna also switches between two frequencies by controlling current path between main and parasitic patches through switches. Its performance evaluation is carried out with the help of simulation and physical verification and the results are presented

A HIERARCHICAL SCHEME TO ACHIEVE FIND TIME AND OPERATION ON DOCUMENTS

Many works were suggested in many types of threat to achieve various benefits for search for example single keyword search, multi-keyword rated search, and so forth.  Of individuals works, multi-keyword kinds of rated search is becoming more importance because of its realistic effectiveness.  We submit a great search method which draws on the tree above encoded cloud information, and it also manages multi-keyword search furthermore to dynamic process on selection of documents.  For acquiring of high search effectiveness, we produce a tree-based index structure and propose an formula using the index tree. The forecasted plan is called to provide multi-keyword query furthermore to a particular result ranking, in addition dynamic update above document collections. Due to important structure of tree-based index, forecasted search system will effectively get sub-straight line search serious amounts of manage the operation of deletion furthermore to insertion of documents

DEVELOPMENT OF ULTRA-CAPACITOR BASED DVR FOR POWER QUALITY IMPROVEMENT

Power Quality (PQ) is that the most vital views at transmission and distribution levels. The availability of high-grade electrical services needed to the purchasers illustrates this idea. The voltage sag and swell square measure the foremost frequent PQ issues that mainly occur within the distribution systems since it's going to cause equipment tripping, failure of drive systems, closure for domestic and industrial instrumentality. The Dynamic Voltage Restorer (DVR) connected nonparallel has splendid dynamic capabilities and is a versatile answer for PQ issues. Ultra-capacitors (UCAP) have ideal characteristics like high power and low energy density essential for the mitigation of voltage sag and swell. This paper presents AN increased DVR topology capable of delivering deep, extended mitigation for power quality issues. Within the planned DVR, UCAP is employed as energy storage because it provides excessive power in an exceedingly short interval of your time. The DVR is integrated into Ultra capacitor via bifacial DC-DC converter which supports in presenting a rigid dc-link voltage, and conjointly helps in compensating temporary voltage sag and voltage swell. PI Controller is employed in DVR for power quality improvement. The simulation model for the proposed system has been developed in MATLAB and therefore the performance over standard DVR is valid with the results obtained

Thin films of perfectly polar crystallites with uniaxial orientational ordering

The family of metal-organic complexes,(4-dialkylaminopyridyl)bis(acetylacetonato)zinc(II) which show perfectly polar assembly in the crystalline state are found to grow as orientationally ordered crystallites in vapor deposited thin films on glass substrates. A unique crystallographic axis of the crystallites, the longest unit cell axis in most cases, is oriented perpendicular to the substrate plane. The fact that the current observations cover a family of compounds is novel and of general significance for oriented thin film growth on amorphous substrates. Crystal structure, thin film morphology and second harmonic generation of a representative system are presented; the crystallites in the thin films do not show azimuthal orientational ordering