Design verification of heat exchanger for ballast water treatment

Using waste heat from ship's engines is one of the methods considered for heat treatment of ballast water. For such a system harvesting the engine exhaust heat, a heat exchanger will be vital. Design optimisation of a heater employing exhaust gases of the engine as utility fluid and ballast sea water as the process fluid was achieved using Lagrangian methods, keeping the annual cost as the objective function. Costs for installation, maintenance as also costs for the utility and process fluids were considered. Heat balance data, specific fuel consumption values from a typical operational ship and current fuel costs were considered for the design. The thermodynamic and geometric designs were worked out using computer based software for comparing the designs. Costs were also computed using a different approach for all the designs. Since the amount of heat transferred was specified and the application was limited to a single process, direct cost method was used for the computation. The objective function values obtained from Lagrangian equations were compared with the values obtained from direct cost computations. From the optimal designs, choice was justified based on annual cost, optimum exit temperature of shell side fluid and optimum mass flow of tube side flui

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Stern Flap for resistance reduction of planing hull craft: a case study with a fast crew boat model

The Study On Various Methods Of Reducing The Resistance Of Patrol Craft Have Been Carried Out By Many Researchers. These Methods Included The Application Of Stern Flaps, Stern Wedges, And Microbubble Injection. However, Due To Its Simplicity And Practicality, Stern Flap Is The Most Promising And Cost Effective Method. The Effect Of A Stern Flap On The Resistance Performance Of The Planing Hull Crew Boat Is Presented. Model Tests Were Conducted To Prove The Effectiveness Of The Stern Flap On Reducing Planing Hull Craft Resistance. Five Different Stern Flap Designs Were Tested As Part Of Systematic Investigation To Determine The Optimum Geometrical Characteristics Of The Stern Flap. Results Of Model Resistance Experiments Showed That Four Of The Flaps Tested Showed An Increase In Resistance While The Flap At Zero Degree Angle Reduced The Total Resistance By 7.2 Percent At 23 Knots, And An Average Reduction Rate Of 4.5 Percent. At 23 Knots, An 8.2 Percent Reduction In Effective Power Was Predicted

Comparison study of a Pusherbarge system in shallow water, medium shallow water and deep water conditions

The study of pusher–barge system in this paper is a continuation research of nine different pusher–barge systems and eight unconventionally arranged pusher–barge systems (Yasukawa et al., 2007; Koh et al., 2008a,b). In this study, pusher–barge system with one pusher and one barge arranged in a linear combination (11BP) was brought into shallow water condition and tested at Kyushu University, Japan with water height to ship draught ratio (h/d): 1.2 (shallow water); 1.5 (medium shallow water); and 19.3 (deep water) conditions. Least squares' fitting method was used in determining the hydrodynamic derivatives that are suitable for the three water draught ratio conditions. Linear derivatives from the experiments were compared with studies from different researchers (Fujino and Ishiguro, 1984; Yoshimura, 1986; Yoshimura and Sakurai, 1989). Added mass was calculated using singularity distribution method under the assumption of rigid free surface. Propeller and rudder hull interaction parameters were pre-assumed based on the study of other researchers. In the study, negative course stability was found in shallow water condition (unstable in course keeping). Maneuvering simulations at 20° and 35° turning show that pusher–barge 11BP has the largest turning circle in deep water condition and smallest turning circle in shallow water condition. Course keeping ability decreases from deep water to medium shallow water to shallow water conditions

Design of Malaysian fishing vessel for minimum resistance

Due to the economic and operational reasons, there is a need to reduce resistance of fishing boats. One of the ways to reduce resistance is to modify the boat hull form to reduce its drag in water. However, designers normally have problems in choosing which hull form parameter to change, in which direction, and the degree of changes required. This paper describes a methodology of incorporating resistance optimization in the design of fishing boats. By producing easily understood design charts, the designer is guided in making his choice. An example of application of this method on the design of a Malaysian fishing boat is given. It is shown that by using this method, the hull can be modified without changing the principal dimensions and displacement and this slight modification of the hull form can produce up to 12% saving in fuel consumption

Design of malaysian fishing vessel for minimum resistance

Due to the economic and operational reasons, there is a need to reduce resistance of fishing boats. One of the ways to reduce resistance is to modify the boat hull form to reduce its drag in water. However, designers normally have problems in choosing which hull form parameter to change, in which direction, and the degree of changes required. This paper describes a methodology of incorporating resistance optimization in the design of fishing boats. By producing easily understood design charts, the designer is guided in making his choice. An example of application of this method on the design of a Malaysian fishing boat is given. It is shown that by using this method, the hull can be modified without changing the principal dimensions and displacement and this slight modification of the hull form can produce up to 12% saving in fuel consumption

The study of ducted propeller in propulsion performance of a Malaysia fishing boat

Through the installation of ducted propeller,fishing vessels are able to operate with more towing power and will be more economic in terms of fuel usage. The application of the shroud or ring to the propeller made the propeller more practical for tugs, pushboat, supply ship and trawler. The study of this paper is focused on the propulsive performance by ducted propeller when operating at tow speed and low rpm. From the research on the ducted propeller, the design characteristics such as length-diameter ratio and thickness-length ratio are determine from the chart provided by previous researcher. The design selection of nozzle is done with the use of CFD program, Javafoil to analyze the flows of the profile and it’s characteristic. Model tests were conducted by using a 26m fishing boat model with and without nozzle. It is foundthat by using ducted propeller to a fishing vessel, thrust can be increase up to 23%