The propeller is an important load of the ship. can overcome resistance ship through control propulsion motor to speed and direction relationship between interaction suffered by during navigation very complex, many factors will affect movement propeller, so it select a suitable mathematical model propeller. In this paper, modeling simplified properly, calculation improved on basis ensuring simu...

Introduction Short-axis and long-axis PROPELLER echo planar imaging (referred to as SAP-EPI and LAP-EPI, respectively) [1, 2] have been developed as alternatives to fast spin echo (FSE)-based PROPELLER sequences [3]. EPI-PROPELLER typically requires fewer shots than FSE-PROPELLER, and is less SAR-intensive. Like other EPI sequences, however, both SAPand LAP-EPI are sensitive to eddy currents th...

The crystal structure of the synthetic DNA dodecamer CGCATATATGCG has been solved at 2.2-A resolution. Its central 6 base pairs adopt the alternating-B-DNA helix structure proposed nearly a decade ago. This alternating poly(AT) structure contrasts with the four known examples of what can be termed a poly(A) subfamily of B-DNA structures: CGCAAAAAAGCG, CGCAAATTTGCG, CGCGAATTCGCG, and CGCGAATTbrC...

Surface-Piercing Propellers (SPPs) have been widely used in high speed craft due to some desirable features such as high efficiency, omission of resistance of equipment attached to the propeller and proper functioning of cavitation. Unlike the submerged propellers, theoretical methods have no significant application on simulation of SPPsbecause of problems related to modeling of these propeller...

INTROdUCTION: The concept of freestyle propeller flaps provides a versatile opportunity for wound closure at any part of the body with minimal donor site morbidity. As experience and familiarity with microsurgical procedures has increased interest in identifying-harvesting perforator flaps originating from known major vessels has become more common. The “freestyle” concept developed by Wei and ...

A methodology for the design of small autonomous underwater vehicle propulsion systems has been developed and applied to the Virginia Tech 690 AUV. The methodology is novel in that it incorporates fast design level codes capable of predicting the viscous effects of low Reynolds number flow that is experienced by small, slow turning propellers. The methodology consists of determining the minimum...

BACKGROUND A great variety of flaps have been used in lower limb reconstructive surgery: random pattern flaps, axial flaps and free microsurgical transfers with many variants. After further research on the cutaneous blood supply and improvement of microsurgical techniques, perforator propeller flaps began to be studied and used. MATERIAL AND METHOD A propeller flap is defined as an insular fl...

Original scientific paper Although there have been important developments in marine propellers since their first use in 1850, the main concept has been conserved. Parallel to the developments in the computer technologies in the past 50 years, methods based on the circulation theory are often used for the design and analysis of propellers. Due to the ability to predict the propulsion performance...

Seagrasses play a critical role in the function and structure of coastal ecosystems, and they are an important habitat for a variety of marine organisms. Damage to seagrass beds caused by boat propeller scarring is significant in many areas. This study was designed to assess the impact of varying scarring intensities on nekton density. We selected ten replicate (10 m·25 m quadrats) sites repres...