identification of the best vegetation indices (vis) for use in quantitative analyzes of vegetation is one of the important issues for ecologists. the objective of this study was sensitivity evaluation of vegetation indices to a stand volume for identification of the best vegetation index (vi) in stand volume estimation using a statistical sensitivity method. also, another objective of this stud...

This paper presents the design, development and characterization of contractile water jet thruster (CWJT) for mini underwater robot. Instead of electric motor, this CWJT utilizes the Ionic Polymer Metal Composite (IPMC) as the actuator to generate the water jet. The main focus of this paper is to analyze the conceptual design of the proposed CWJT which would determine the thrust force value, je...

The problem of minimum-fuel, time-fixed, low-thrust rendezvous is addressed with the particular aim of developing a solver to determine optimal low-thrust Peer-to-Peer (P2P) maneuvers, which will be an integral part of distributed lowthrust servicing missions for multiple satellites. We develop the solver based on an indirect optimization technique and utilize the well-known shooting method to ...

The effect of fuel to oxidiser ratio on the thrust performance of a novel CubeSat propulsion system is presented in this paper. This propulsion system uses aluminium wool as fuel and a mixture of water and sodium hydroxide as oxidiser. The goal of the experiment is to determine the effect of fuel to oxidiser ratio on the thrust profile of the device, as measured with a pendulum type thrust bala...

The first Dynamic Positioning (DP) systems emerged in the 1960’s from the need for deep water drilling by the offshore oil and gas industry, as conventional mooring systems, like a jack-up barge or an anchored rig, can only be used in shallow waters. GustoMSC has been developing DP drill ships since the early 1970’s and it is still one of their core businesses. DP systems automatically control ...

Vertical turbine pumps are designed to operate with the pump shafts in tension (downthrust). Most pump and motor manufacturers caution users to not operate the vertical turbine pumps at conditions that result in “upthrust.” Upthrust conditions are usually encountered for a few seconds each time the pump is started; however, the pump should not be operated for periods longer than a few seconds i...

In this paper a nonlinear thrust controller for fixed pitch marine propellers with torque loss estimation and an antispin strategy is presented. The controller, designed to operate in the four-quadrant plane composed by the shaft speed and the vessel speed, is a combination of a thrust controller developed for calm/moderate sea states and an anti-spin strategy to reduce power peaks and wear-and...

Metapelites collected in central Nepal reveal a discontinuity in metamorphic pressuretemperature-time (P-T-t) paths near the base of the Main Central thrust zone, despite an absence of obvious structural breaks. Garnets in the structurally lowest rocks grew with increasing T and P (loading), whereas garnets 1–3 km upsection grew with increasing T, but decreasing P (exhumation). Monazite grains ...

In this paper, we present a detailed dynamic and aerodynamic model of a quadrotor that can be used for path planning and control design of high performance, complex and aggressive manoeuvres without the need for iterative learning techniques. The accepted nonlinear dynamic quadrotor model is based on a thrust and torque model with constant thrust and torque coefficients derived from static thru...

In order to compute the thermal deformation of the hydrostatic thrust bearing in the heavy type CNC equipments, a numerical research concerning temperature field of multi-pad hydrostatic thrust bearing having sector cavity, rectangular cavity, Ishaped cavity and ellipse cavity is described. Three-dimensional temperature field of gap fluid between the rotation worktable and the base has been sim...