Search results for "PIP"

Analysis of pipeline accidents in the United States from 1968 to 2009

2014

Pipelines are responsible for the transportation of a significant portion of the U.S. energy supply. Unfortunately, pipeline failures are common and the consequences can be catastrophic. Drawing on data from the Pipeline and Hazardous Materials Safety Administration (PHMSA) that covers approximately 40,000 incidents from 1968 to 2009, this paper explores the trends, causes and consequences of natural gas and hazardous liquid pipeline accidents. The analysis indicates that fatalities and injuries from pipeline accidents are generally decreasing over time, while property damage and, in some cases, the numbers of incidents are increasing over time. In five of the ten cases considered in this p…

Robust Tool Point Control for Offshore Knuckle Boom Crane

2011

Author's version of a chapter in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.03004

Direct analitical solution for turbulent pipe-flow problems

1977

Trajectory tracking of underactuated underwater vehicles

2003

This paper deals with a control strategies for underactuated underwater vehicles whose target is the tracking of a space trajectory. A cascade control strategy is employed which brings to a control law consisting of: 1) a kinematic control law, derived from the vehicle kinematic model, which forces this model to track the reference trajectory; and 2) a dynamic control law which forces the system to track the reference signals given by the kinematic control law. Conditions for asymptotic tracking of the trajectory are given with reference to the standard dynamical model of the above vehicle. An observer of the marine current is also added in order to process the control law. Simulation tests…

Residence time distribution of solid particles in a continuous, high-aspect-ratio multiple-impeller stirred vessel

2004

Abstract In this paper experimental information on the retention time distribution (RTD) of solid particles in a high-aspect-ratio vessel, stirred by three equally spaced Rushton turbines, is presented. The relevant data were obtained by a special technique named twin system approach (TSA) that greatly simplifies the handling of particle-laden streams and is therefore particularly suited for investigating particle RTD in flow systems. The technique fundamentals are first summarized, together with the data analysis procedure. This lastly requires a numerical deconvolution operation that is easily performed with the help of Z -transforms. Two different approaches for excluding the spurious co…

Discussion of “Analysis of Geometrical Relationships and Friction Losses in Small-Diameter Lay-Flat Polyethylene Pipes” by Giuseppe Provenzano, Vince…

2016

For a lay-flat drip line with an inner nominal diameter dn = 16 mm, characterized by three different pipe wall thicknesses, WT, 6, 8 and 10 mil, the Authors of the original paper very accurately investigated the geometrical expansion of the cross-sectional diameter as a function of different pressure head values, ranging in between 0.84-17.55 m. Results obtained by the Authors, for pressure heads not exceeding a threshold pressure value, showed significant d variations, in a very narrow range of pressure heads, which however is seldom considered in practice (less than 3 m). The Authors experimentally evaluated a modified Blasius’ law friction coefficient, c, equal to 0.285, corresponding to…

Conceptual study of the coupling of a biorefinery process for hydrothermal liquefaction of microalgae with a concentrating solar power plant

2017

A conceptual analysis of the coupling of a concentrating solar power plant with a chemical process for hydrothermal liquefaction (HTL) of microalgae to biocrude was performed. The two plants were considered coupled by molten salt recirculation that granted energetic supply to the chemical process. Preliminary estimations have been done considering a solar field constituted by 3 linear parabolic solar collectors rows, each 200 m long, using a ternary molten salts mixture as heat transfer fluid, and a chemical plant sized to process 10 kT/y of microalgae. Under adopted conditions, we have estimated a minimum selling prize of the biocrude that is similar to that achieved in non-solar HTL proce…

Efficient pipeline FFT processors for WLAN MIMO-OFDM systems

2005

The most area-efficient pipeline FFT processors for WLAN MIMO-OFDM systems are presented. It is shown that although the R2/sup 3/SDF architecture is the most area-efficient approach for implementing pipeline FFT processors, RrMDC architectures are more efficient in MIMO-OFDM systems when more than three channels are used.

Simultaneous zonation and calibration of pipe network parameters

2003

A procedure for simultaneously zoning and calibrating pipe network parameters is proposed and applied to the determination of pipe resistance coefficients. The methodology is aimed at grouping the parameters of all the pipes into a small number of zone parameters, constrained to keep the difference between the computed and the measured water heads below a given tolerance. It is shown that, in the case of nonlooped networks, the methodology leads to a linear minimization problem where the objective function is a measure of the heterogeneity of the estimated parameters. In the case of looped networks an iterative procedure, where the linear problem is coupled with a nonlinear problem having a…

Assessing a Local Losses Evaluation Procedure for Low-Pressure Lay-Flat Drip Laterals

2014

In the past, several research experiments have focused on the hydraulic characterization of traditional drip irrigation systems, and different design methodologies have been proposed with the aim of achieving very high emitter discharge uniformity (EU). The increasing use of low-pressure lay-flat drip laterals, characterized by a thin-walled polyethylene pipe, makes necessary a specific determination of their hydraulic properties, aimed to a correct design of such systems. Here, the validity of an empirical local losses estimation model was assessed for five different commercial lay-flat drip tapes. Moreover, the errors in the maximum lateral lengths obtained for a fixed emitter uniformity,…