bluuebunny/crossref_metadata_2025 huggingface dataset:
On Acquisition Reform, Risk and Structural Reliability
Authors: Hess P. E. , Beach J. E.
Published: October 2008

U.S. Navy acquisition reform is presented as a means of reducing costs and risks in the acquisition process, while providing improved mission performance for Navy assets. The DD 21 acquisition program is an outgrowth of this desire, with the attainment of the U.S. Navy's performance goals by new designs being demonstrated by commercial design teams instead of being based upon traditional, detailed military specifications. One role of the U.S. Navy technical community will be to certify that the design meets the program performance goals. Because of an absence of formal performance metrics, there may be unmitigated risks that the certification process will either approve an unacceptable design or reject an acceptable design. Both types of risk would negatively impact the U.S. Navy acquisition process. This paper discusses the programmatic risk reductions inherent in adopting a technical risk‐based approach by identifying the role of reliability‐based acceptance criteria for ship structures.
RIB 2000 Database for Performance Improvement
Authors: Latorre R. , Miller A.
Published: October 2008

For nearly 40 years the Rigid Hull Inflatable Boat (RIB) has evolved from a first generation surf boat for lifesaving into a number of second generation utility, recreational and military designs. This paper summarizes the important factors in second generation development such as weight, hull material selection, and engine selection. Then it reviews the compatibility of the RIB with current combatant design objectives — manning reduction, radar cross section reduction, and topside weight reduction — to project the third generation design as an integral component of future combatant designs.
Hull Material Evaluation for Navy 44 Sail Training Craft
Authors: Arvidson M. H. , Miller P. H.
Published: October 2008

Material characterization tests were performed at the U.S. Naval Academy to identify a toughened laminate for the new Navy 44‐foot sail training vessels. After preliminary analysis using classical lamination theory, four different cores, five laminates and seven resin systems were tested in UV exposure, four‐point bending, lateral panel pressure, and simulated bow impact. Results showed substantial improvements in strength, toughness, cost and weight were possible over the existing laminate, with the lightest acceptable laminate yielding a weight savings equivalent to 3.5% of the vessel's displacement.
The Design Of Visual Landing Aids For Shipborne Helicopter Operations
Authors: Smith A. J.
Published: October 2008

Any aircraft approach to landing that takes place over featureless terrain presents operational difficulties to pilots due to the absence of those ground‐derived textural cues that normally enable them to assess the flight path of the aircraft. Night, low visibility, crosswind and ship motion effects are factors that further increase the task difficulty for ship‐borne operations. Visual aids such as a Glide Slope Indicator are of vital importance in these circumstances.

Currently the trend in helicopter operations from ships is toward more flights taking place in high sea states and low visibility. This reinforces the need for the full stabilization of precision guidance aids and requires the use of high intensity lighting. To support operations in high sea states it is necessary for the visual aids to function at pitch and roll angles greater than those defined for safe landings.

A Stabilized Glide Slope Indicator and a fully Stabilized Horizon Bar together with ship outline lighting significantly enhance the cues that a pilot can derive from the ship. By using green luminescent panels for these latter aids a system is created that is effective in precipitation and is compatible with the use of Night Vision Goggles (NVG). These aids enhance safety and operational limits.
Streetfighter ‐ Sampling Alternatives of Analysis for Future Small Combatants
Authors: Skvarla Kai A. , McKesson Chris B. , Barlow Alan
Published: October 2008

Looking ahead to the challenges that will confront future navies highlights concern over access to battle space vital to the support of expeditionary operations. The blue water might of the current Navy may not prove successful in addressing this concern. The intent of the discussion that follows is to identify the missions for which the small, fast, inexpensive yet heavily armed surface platform could benefit these types of operations. Following that, an effort has been made to define and address major design issues associated with a ship that embodies these characteristics. The ideas presented are a mix of those already discussed in the open literature and extrapolations thereof.
Assessing New Technology For Naval Ships
Authors: Sherman Thomas R. , Wilson Robert A.
Published: October 2008

A unique physics‐based whole ship design synthesis model for assessing the impact of new technologies and mission requirements on naval ship design is presented. This tool permits the cost and performance impact and implications of new technology to be properly understood by the mission analyst, the technologist, and the naval architect. The mission analyst can use the information provided by the design synthesis model as inputs to war‐gaming exercises or to help determine the preferred combination of affordable mission requirements. The technologist can use the model to determine whether the benefits of a specific technology warrant the required investment. The naval architect can use the tool to assess the overall impact of a new technology on the ship design. A discussion on how the model accommodates the competing requirements of speed versus accuracy and flexibility versus ease of use to satisfy the needs for all users is presented. Finally, the benefits of the model to each type of user are demonstrated by specific examples drawn from real applications.
Technology Insertion in Today's Fleet/Force
Authors: Bales S.L.
Published: October 2008

Declining U.S. defense budgets, global proliferation of technology, and the emergence of an uncertain, if not asymmetric, threat environment have led the Office of Naval Research (ONR) to redefine its mission and processes. As the steward for Naval Research since 1946, ONR has traditionally produced scientific breakthroughs and technology options that enable the superior capabilities of the Navy after Next. Since 1992, several steps have been taken to also align ONR with today's and tomorrow's Navy and Marine Corps requirements. This paper will highlight the outreach and reach‐back program that provides the mechanism for Naval Research to more fully support today's forces.
T‐AKE: Acquiring the Environmentally Sound Ship of the 21
Authors: Markle Stephen P. , Gill Sean E.
Published: October 2008

Department of Defense (DoD) program managers are increasingly challenged with the difficulties of balancing the risks associated with cost, schedule, and performance in an era of intense competition for increasingly scarce resources. Requirements associated with environmental, safety, and health (ESH), in the context of thirty to forty‐year service lives, have not been consistently, or in some cases adequately, addressed in DoD programs. Environmental protection (EP) requirements generally do not fit the normal requirements generation and product synthesis model typically applied to weapon system development. As with all requirements, early identification is the key to integration into the total system. Recognition that EP requirements must be integrated at program conception led to development of the ESH Integration Model by the U.S. Navy Lewis and Clark (T‐AKE) Auxiliary Cargo Ammunition Ship Program. Institutionalization of this model has enabled the T‐AKE Program to establish EP performance requirements for the twelve‐ship class that substantially reduce the environmental footprint of the Navy. Compared to the fifteen ships that it will be replacing, T‐AKE will require fifty percent less manning and reduce waste streams by seventy percent enabling an annual life cycle cost savings of $5M in ashore waste disposal costs. The T‐AKE Program has been the first to achieve the Chief of Naval Operations vision for the “Environmentally Sound Warship of the 21st Century” through design integration of EP requirements.
Beyond Electric Ship
Authors: Young Stuart , Newell John , Little Graeme
Published: October 2008

The marine engineering development strategy for the Royal Navy was endorsed in 1996 and formulated a road‐map to achieve life‐cycle cost savings in future warships whilst maintaining operational capability. Since then development work has focused on de‐risking the ‘Electric Ship’ concept so that the technologies are available for use in future warships. This paper reviews progress to date and then discusses how the strategy is likely to change in the future. Potential future technologies are also assessed.
David W. Taylor, Naval Constructor, U.S.N. His Reflections on Ship Protection — Are They Lessons for Today?
Authors: Hansen S. , Wegner Dana M.
Published: October 2008

This article features excerpts from a lecture given at the Naval War College in 1910 by David W. Taylor, Naval Constructor, USN. Among many wise observations in the lecture are some classical views illuminating the constant struggle in ship designs between offensive power and passive protection. We resurrect Taylor's previously unpublished words believing that we are at a similar crossroads today and that we could benefit by revisiting his admonitions. This paper attempts to show why this is so. Historical notes have been provided to further illuminate selected subjects in the text.
Passive Protection Versus Active Defenses
Authors: Hansen Ib S.
Published: October 2008

The increased risk of surprise attacks resulting from changed Navy missions (Hansen 2000; Hansen and Wagner 2001) makes it desirable to consider the possible development of improved passive protection systems. It is not obvious, however, which direction such development should take for optimum returns. This paper provides a tool to compare the effectiveness of different general approaches in terms of the reduction in out‐of‐action probabilities they can provide. A method is described to estimate the probabilities for different ships attacked by weapon salvos, and an illustration of the method is given by applying it to two general conceptual ship types, each with three different postulated levels of passive protection, all exposed to salvos varying from one to four weapons in size. Conclusions are given on the basis of the illustrated example, with the caveat that they should be revisited as additional results are developed. The feasibility of the different approaches to passive protection has to be determined by research and development.
Methodology for Developing Reliability‐Based Load and Resistance Factor Design(LRFD) Guidelines for Ship Structures
Authors: Ayyub Bilal M. , Assakkaf Ibrahim A. , Beach Jeffrey E. , Melton William M. , Nappi Natale , Conley Judy A.
Published: October 2008

The main objective of ship structural design is to ensure safety and functional performance requirements of a structural system for target reliability levels, for a specified period of time, and for a specified environment. As this must be accomplished under conditions of uncertainty, probabilistic analyses are necessary in the development of such probability‐based design criteria of hull structural components for surface ships. A methodology for developing load and resistance factor design (LRFD) guidelines for ship structures is outlined in this paper, and demonstrated for surface ship hull girders. Future design guidelines for hull structural components of a marine vessel are currently being developed using reliability methods and are expressed in a special format such as the Load and Resistance Factor Design (LRFD) format. Reliability of these structural elements can be defined as its ability to fulfill their design functions for a specified time period. This ability is commonly measured using probabilities. Reliability is therefore, the occurrence probability of the complementary event to failure. Based on this definition, reliability is one of the components of risk. Safety can be defined as the judgment of risk acceptability for the system making it a component of risk management.

The performance of a ship structural component is defined by a set of requirements stated in terms of tests and measurements of how well the system or element serves various or intended functions over its service life. Risk and reliability measures can be considered as performance measures that can be specified in the form of target reliability levels (or target reliability indices, β0's). The selected reliability levels of a particular structural element reflect the probability of failure of that element and the risk associated with it.

In this paper, reliability methods for developing LRFD‐based partial safety factors (PSFs) for ship hull structural are described. These methods include analytical procedures, such as the First‐Order Reliability Method (FORM), for calculating the partial safety factors. These factors can be used in LRFD formats to account for the uncertainties in strength and in the load effects. The FORM procedure can be used to determine these factors based on prescribed probabilistic characteristic of strength and load effects.
Risk Analysis and Management for Marine Systems
Authors: Ayyub Bilal M. , Beach Jeffrey E. , Sarkani Shahram , Assakkaf Ibrahim A.
Published: October 2008

Sources of risk to marine systems include equipment failure, external events, human error, and institutional error. Equipment failure, the most readily recognized hazard on ships, may be categorized as either independent failure, such as the loss of steering because of the failure of a power steering pump or common‐cause failure, such as the loss of propulsion and steering resulting from a total loss of electrical power to the ship. Risk from external events arises from hazards such as collision with other ships, sea state; wind, and ice or other weather factors. Humans provide another source of risk to marine systems when they lack skill, are excessively fatigued, or commit sabotage. Institutional failure creates risks from poor management including inadequate training, poor communications, and low morale.

Risk studies may be classified according to whether they focus primarily on assessment, management, or communication; these aspects of risk studies are described to prepare users and readers of this paper for performing risk‐based analysis of marine systems. Methods are provided in the paper that can be used to develop risk‐based standards for system safety. The relationship between risk and standards is studied from a historical perspective. Great successes in controlling risk to health and safety are exemplified by the development of design methods for buildings, bridges, or super tankers that render them capable of withstanding extreme storms. Yet, familiar risks persist while less familiar ones escape attention and new ones appear. Ironically, management of some of the most difficult risks has led to improved standards of living. This paper provides background information, introduces fundamental concepts, and offers examples of risk methods applied to marine systems.
Designing Navy Hull Forms for Fuel Economy
Authors: Karafiath Gabor , McCallum Donald , Hendrix Dane
Published: October 2008

During initial hull form design, a multitude of requirements needs to be met. Among these are mission, ship size, armament, communications, stability, speed, sea keeping, etc. Tools such as ASSET are used to arrive at a design solution that will satisfy all these requirements. However, at this early design stage, attention needs to be given to the hull form shape, and its impact upon fuel consumption. Rising fuel costs and the need to conserve energy have mandated that Navy designs become more “energy efficient.”

This paper documents a new design metric “CPE” for evaluating the resistance of any hull design. A CPE database is developed from historic model test data residing in the U.S. Navy Hull Design Database System (HDDS). CPE compares the resistance of a hull form to that of a similar Taylor Standard Series hull form. The paper also introduces a new hull form optimization computer program developed by Naval Surface Warfare Center (NSWC) and applies this program to show the potential for hull form improvement and fuel cost savings.
Submarine Officer of the Deck Training Using Virtual Environments: An Assessment of Training System Capabilities
Authors: Vincenzi Dennis A. , Hays Robert T. , Seamon Alton G.
Published: October 2008

In recent years, virtual reality (VR), often called virtual environments (VE), has received an enormous amount of attention among training developers. Training developers are beginning to recognize the potential of VR as a flexible and effective training medium. A prime candidate for examining the effectiveness of VR systems is the training of officer of the deck (OOD) ship handling for the surfaced submarine. The virtual environment for submarine OOD ship handling training (VESUB) project developed, demonstrated, and evaluated the training potential of a virtual reality‐based system for OOD training. This article documents the effectiveness of the training provided by the VESUB trainer during the training effectiveness evaluation (TEE) of the VESUB technology demonstration.

Data were collected on 15 ship handling variables grouped into seven skill categories. The results clearly indicated that the VESUB system was extremely capable of providing training to new recruits who knew very little about submarine ship handling, as well as refresher training for the experienced, qualified OOD. Significant learning was demonstrated on 11 of 15 performance measures. The results of the TEE strongly indicate that VR technologies can provide effective training on ship handling skills across a wide variety of experience levels.
Knowledge Warfare in the 21ST Century: An Extension in Performance
Authors: Masakowski Yvonne R.
Published: October 2008

As we move into the 21st century, we are faced with a critical need to address the ways in which knowledge is generated and used to optimize system and human performance. Today, we are inundated with a plethora of information, emails, and ever‐changing software. There is a dynamic relationship among humans, computers, expert systems and intelligent agent software that shapes the way we live, conduct business and participate in war. It is imperative that we master the critical components of knowledge management that will enhance their decision‐making capacities and empower the warfighter.

In the 21st century, knowledge management tools, intelligent agent architectures, robotics, and automated systems will facilitate expert performance necessary to fortify net‐centric warfare. One of the principal metrics of performance will be our ability to reduce uncertainty and provide the most accurate information to the decision‐maker at the right time. The importance of these goals becomes clear when considered within the context of images of the World Trade Center (WTC) crumbling to the ground. Now, we understand the cost of poor information in terms of life and freedom.

This paper will provide an introduction to the importance of knowledge management and implications for future ship design.
Function Allocation: Policy, Practice, Procedures, & Process
Authors: Malone Thomas B. , Heasly Christopher C.
Published: October 2008

Allocation of functions is known by human systems integration professionals as encompassing both a process and a product. As a process, function allocation refers to the sequence of steps involved in establishing the alternate roles, responsibilities, and requirements for humans and machines in a complex human‐machine system. As a product, function allocation refers to the end state of the application of the process, the optimal distribution of roles, responsibilities and tasks between humans and machines.

When the system development objective is to downsize emerging systems as compared with existing systems, the focus of the allocation of function effort changes from an emphasis on optimizing human roles to minimizing human involvement in system functions. In addressing the issue of performing system functions with fewer humans as compared with existing systems, the function allocation strategy is not simply to assign functions to automated or manual performance on the basis of differential capabilities and capacities of the two, as exemplified in the Fitts’ List approach. Rather, the strategy is to automate functions to the extent needed to enable the required reduction in workload and manning, with attendant provisions for decision aiding, task simplification, and design in conformity with human engineering standards to ensure adequate levels of human performance and personnel safety.

Another change in emphasis when allocating functions for a reduced manning system is the focus on interaction between human and machine. In the reduced manning environment humans and machines are not viewed as competing resources to which responsibilities are assigned on the basis of their unique and individual capabilities but rather as cooperative elements of a system interacting and collaborating in synergy to achieve the system objectives.
Reliability Assessment of Corroding Ship Hull Structure
Authors: Akpan Unyime O. , Koko T. S. , Ayyub B. , Dunbar T.E.
Published: October 2008

An approach for reliability assessment of the ultimate strength of a ship hull structure in the presence of corrosion is developed. Corrosion growth is modeled as a time dependent random function that decreases the thickness of ship hull structural members with time. The second order reliability method (SORM) is used to calculate instantaneous reliability of the primary hull structure. The methodology for computing the time dependent reliability of a corroding ship structure is developed. Sensitivity of the time dependent reliability of the structure to statistical and probabilistic description of the corrosion growth parameters is investigated. An example problem involving a corroding tanker structure is used for demonstration.
Risk Based Inspection Planning for Ship Structures Using a Decision Tree Method
Authors: Li Dianqing , Zhang Shengkun , Tang Wenyong
Published: October 2008

A theoretical framework of risk‐based inspection and repair was proposed for ship structures subjected to corrosion deterioration. A repair index was presented to consider reliability updating after repair. The reliability updating after inspection and repair was performed by using the Bayesian updating method. A decision tree was established for selecting the optimal inspection and repair strategy for ship structures. By comparing the expected costs associated with different inspection and repair strategies, the smallest expected cost associated with the inspection and repair strategy can be identified as the optimal one. Based on this, a method was proposed to determine the sensitivities of both optimal inspection and repair strategy. Furthermore, some formulae were derived to analyze the sensitivities. A numerical example was investigated to illustrate the process of selecting the optimal inspection and repair strategy. The results show that the decision tree method is very effective. Furthermore, different values of various costs have significant effects on the reliability and stability of decision results.
Comparison of Three Inner‐Variable Approaches to Establish an Accurate Method for Turbulent Boundary Layers
Authors: Das Debendra K. , Naganathan Surrandar , Kono Toshifumi , Kulkarni Devdatta
Published: October 2008

An inner‐variable integral theory was derived for solving incompressible two‐dimensional turbulent boundary layers. This new derivation incorporated major improvements to the earlier inner‐variable approach of White (1974) and Das and White (1986) by including a better wake function and a superior pressure gradient‐wake correlation. Initially, the derivation from the first principle led to three nonlinear ordinary differential equations that must be solved simultaneously to yield important boundary layer parameters. Subsequently, to simplify the theory, it was systematically reduced in two steps: first to a two‐equation method, and next to a one‐equation method. Then comparisons were carried out among the three methods using well‐established experimental data from a wide range of flows. The two‐equation method gave the best overall performance and was selected as the standard method. Finally, it was tested against additional experiments, giving reliable predictions against eleven different experimental flows under diverse flow conditions.
A Knowledge‐Based Computational Design Tool for Determining Preliminary Stability Particulars of Naval Ships
Authors: Alkan A.D. , Gülez K.
Published: October 2008

The preliminary design stage of a ship constitutes an important base from which to develop the preliminary ship characteristics to be used as goals in the following stages of the ship design process. Thus, reliable and efficient design tools are required by ship designers to determine ship design particulars that can satisfy various performance measures of stability for safety requirements, as well as resistance, volume, and load capacity to set economic targets. In this study, a robust neural network (NN) structure is established and using principle design data from 22 naval ships (Bartholomew et al. 1992), a reliable design tool for ship designers for determining ship preliminary stability particulars and as well as load capacity is developed. In the NN structure the classical back‐propagation (CBA) (Rumelhart et al. 1986) and fast back‐propagation (FBA) (Karayiannis and Venetsanopoulas 1991, 1992, 1993) algorithms are employed.

The user inputs a set of common ship hull form parameters, while the output from the NN consists of the transverse center of gravity above keel (KG), the transverse metacenter above keel (KM), and the transverse metacenter above center of buoyancy (BM). Further, the dead‐weight tonnage capacity (DWT) is also determined using the same NN structure. According to various tests of the NN structure it is demonstrated that the model is able to give highly sensitive outputs for naval vessels even using a more restricted input data set. Depending on the availability of the design data structure the proposed model can be reconstructed for other preliminary design objectives such as predicting the powering performance for different classes of ships.
Plasma Arc Waste Destruction System (PAWDS) A Novel Approach to Waste Elimination Aboard Ships
Authors: Kaldas Aïda , Picard Isabelle , Chronopoulos Christos , Chevalier Philippe , Carabin Pierre , Holcroft Gillian , Alexander Gary , Spezio Joseph , Mann Jim , Molintas Henry
Published: October 2008

The Plasma Arc Waste Destruction System (PAWDS) uses plasma energy, with temperatures over 5,000oC, to rapidly and efficiently destroy combustible waste aboard ships. PAWDS has proven itself to be a viable alternative to traditional incinerators. » In September 2003, Carnival Cruise Lines were the first to install a PAWDS aboard their 2,056 passenger (plus 1,000 crew members) capacity, M/S Fantasy cruise ship, to treat ship waste including paper, cardboard, plastics, textiles, wood, and food. As of June 2004, it is being operated and maintained solely by Carnival Cruise Lines personnel and has been permitted to operate in port by the Bahamian port authorities. » The Navy's next generation aircraft carrier, CVN 21, will be equipped with two PAWDS to process all of the non‐food combustible solid waste generated with sufficient system redundancy. The US Navy has been jointly developing the PAWDS with PyroGenesis Inc. over the last 6 years. The development efforts in 2004 and 2005 coupled with lessons learned from operation aboard Carnival's cruise ship have resulted in the identification of additional process and design improvements. Source emission testing by an independent laboratory has also demonstrated that the PAWDS easily meets IMO MARPOL requirements for the destruction of solid waste.
Climate Change and the Future of Shipping and Ship Design
Authors: Breslin David A.
Published: October 2008

In 2001, the Intergovernmental Panel on Climate Change (IPCC) issued a series of alarming reports that outlined the likely consequences of climate change over the next 50 to 100 years. Subsequent to those reports, in early 2005, the Kyoto Protocol took effect, establishing modest targets for reducing emissions of global‐warming gases by certain countries. Those targets are widely considered to be inadequate to do the job. » In 2007, the IPCC will issue its next series of reports, and it is widely anticipated that those reports will paint a grim picture of the future, possibly setting off another round of calls to action and negotiations for tougher treaty requirements. » Whatever the immediate reaction to the 2007 IPCC reports, determined action by developed and developing nations alike appears inevitable. That determined action will affect every economic sector, including the shipping and shipbuilding industries. » So it's coming time for the leaders, owners, operators, technologists, designers, and manufacturers in the U.S. domestic shipping and shipbuilding industries to begin contemplating what actions they will take to address possible legal requirements associated with global climate change. » Previous papers on climate change by this author have focused on ship technologies (Breslin & Wang, 2004) as well as DoN acquisition strategies (Breslin, 2003). The purpose of this paper is to outline where we are and where we are likely to be going relative to treaties and domestic legislation associated with climate change, speculate on the likely implications relative to shipping and shipbuilding, and outline a rough path into the future.
Near-Net-Shape Manufacturing of Short Fiber Composite Parts via Discrete Depositions
Authors: Gunnerson K. A. , Cipra R. J. , Siegmund T.
Published: October 2008

A novel approach for the near-net-shape manufacturing of short fiber reinforced composite parts through robotic deposition of chopped fibers is presented. A device for the deposition of discrete packets of short fibers is developed. A simulation tool is described that predicts the optimal locations within a mold to deposit fibers from the deposition device in order to obtain composites with a uniform fiber density distribution within a part of complex perimeter geometry. The implementation of the deposition device in conjunction with a six-degree-of-freedom robot is described. Composite preforms are generated, and subsequently converted into composite parts via resin transfer molding. Mechanical testing was conducted on near-net-shape manufactured notched specimens and notched specimens machined from the bulk. Testing shows that the near-net-shape manufactured specimens possess at least equal stiffness and strength to those machined from the bulk.
Genetic variability and structure ofGomortega keule(Molina) Baillon (Gomortegaceae) relict populations: geographical and genetic fragmentation and its implications for conservation
Authors: García-Gonzáles Rolando , Carrasco Basilio , Peñailillo Patricio , Letelier Luis , Herrera Raúl , Lavandero Blas , Moya Mario , Caligari Peter D.S.
Published: October 2008

Gomortega keule (Molina) Baillon is a rare Chilean species classified as endangered and currently under conservation. Currently, conservation of this species is carried out by private companies and government agencies, but is done so based more on pragmatic criteria than scientifically based strategies. In this context, information concerning the genetic variability of the species among the different populations over its entire distribution range is incomplete, making it difficult to coordinate management and conservation strategies. Here we report a study to evaluate the genetic variability and population structure of G. keule over its entire distribution in Chile. Twenty-five ISSR primers for 223 individuals from 11 geographical populations were tested to evaluate genetic variability. Results showed a high level of genetic diversity for the species. A high level of genetic differentiation among populations was found, while genetic structure of the geographic populations was also shown by using STRUCTURE 2.1 software. Despite the fact that this species has been highly affected by human intervention and habitat destruction, a high level of genetic diversity was present. A likely explanation for this is that it reflects the previous distribution of this long-lived species and the current lack of sexual regeneration. Genetic diversity data must be considered in the development of a management strategy for further developing the protected areas, for identifying isolated small populations for conservation, and using larger populations with higher genetic diversity as seed sources for ex situ propagation and replanting.
Decreased Survival and Calcium Uptake by the Crayfish Orconectes virilis in Low pH
Authors: Malley D. F.
Published: October 2008

As part of a study of the effects of the experimental whole-lake acidification of Lake 223 in the Experimental Lakes Area on the population of the crayfish Orconectes virilis physiological responses of adults from this population to low pH were examined in the laboratory. Crayfish survived pH 4.0 for 10 d when they were not moulting but suffered mortality when they were in postmolt stages. Postmolt crayfish held at pH 5.0 for 10 d survived but showed slower progression of molt cycle stages and of calcification of the exoskeleton than individuals held at pH 6.0 or in lake water at about pH 6.7. Uptake of Ca++ by postmolt crayfish measured by the use of 45Ca as a tracer was inhibited by pH below 5.75 and ceased altogether below pH 4.0 when these levels of acidity were applied acutely.Key words: Orconectes virilis, crayfish, molt cycle, mortality, pH, calcification, postmolt calcium uptake, acid rain, lake acidification
Continuous Culturing of Natural Phytoplankton Communities in the Experimental Lakes Area: Effects of Enclosure, in situ Incubation, Light, Phosphorus, and Cadmium
Authors: deNoyelles Jr. F. , Knoechel R. , Reinke D. , Treanor D. , Altenhofen C.
Published: October 2008

Continuous culture chambers containing and receiving raw lake water as an inflow were incubated in the laboratory and in situ. This was done to determine the suitability of continuous algal culture for recording the responses of lake phytoplankton to experimentally imposed perturbations simulating environmental changes. The distribution of the phytoplankton in control chambers, particularly with in situ incubation, remained similar to that of the lake. Other chambers produced changes in distribution as responses to perturbations of filtered inflow, light, a nutrient, and cadmium. These responses were consistent with existing data for lakes at the Experimental Lakes Area, including the responses to cadmium which were compared to those from tube experiments. The relative merits of these and other types of enclosures including batch cultures, large bags, and tubes are discussed.Key words: phytoplankton culture, enclosure effects, phosphorus, light, cadmium, bioassay, microcosms
Denitrification in Lake 227 During Summer Stratification
Authors: Chan Y. K. , Campbell N. E. R.
Published: October 2008

In situ denitrification in Lake 227 was assayed by using 15N-labeled NO3− during summer stratification periods in 1973, 1974, and 1975. Dissolved oxygen and NO3− concentrations were the main factors controlling denitrification in the water column and in sediments. The epilimnetic sediment–water interface was a more significant site of natural denitrification when compared to the oxygen-limiting (dissolved oxygen less than 0.2 mg/L) thermocline and the anoxic hypolimnion. Epilimnetic sediment denitrification rates averaged about 15 mg N∙m−2∙d−1. Nearly all of the NO3− that mixed into the surficial sediments was denitrified. Alone, epilimnetic denitrification removed 1.4% of the NO3− added annually. Below the euphotic zone, sediments would provide an efficient sink for NO3−-N without simultaneous initiation of eutrophication.Key words: denitrification, nitrogen sink, nitrate in lakes, experimental lakes, summer stratification
Is Juvenile Natural Mortality in Marine Demersal Fish Variable?
Authors: Myers Ransom A. , Cadigan Noel G.
Published: October 2008

We test the hypothesis that the interannual variability of the density-independent component of juvenile natural mortality is a major source of variability in abundance of marine demersal fish. Our tests use data on populations for which there are research surveys consisting of two simultaneous estimates of abundance of young juveniles soon after settlement and two more simultaneous estimates of the same cohort a year later. We applied our test to 14 populations of Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), plaice (Pleuronectes platessa), and sole (Solea vulgaris). We conclude that, in all populations examined except North Sea sole, there was very little or no interannual variability in the density-independent component of juvenile mortality.
Foraging Flexibility in Pumpkinseed (Lepomis gibbosus); Influence of Habitat Structure and Prey Type
Authors: Kieffer J. D. , Colgan P. W.
Published: October 2008

Foraging behaviour of pumpkinseed (Lepomis gibbosus) was investigated in feeding arenas containing different habitat structures and prey types in two sets of experiments, each of three successive 10-d blocks. (A) Two groups of eight foraged in open-water habitats on different prey items: group 1 was presented with prey in the order white worms, fruit flies, white worms and group 2 with fruit flies, white worms, fruit flies. Both capture rate and success increased with successive trials for both prey types, indicating that foraging efficiency increased with experience. Shifts from one prey type to another changed performance; however, overall foraging efficiency did not change dramatically when fish were shifted back to feeding on a previously encountered prey type. (B) Two groups of eight foraged on white worms: group 1 in the habitat order open water, structured, open water and group 2 in structured, open water, structured. Fish fed faster in an open-water habitat but were flexible in a structured habitat. When fish returned to feeding in a familiar habitat type, behavioural patterns were very flexible. The results of these two experiments show that the foraging behaviour of pumpkinseed is relatively sensitive to temporally and spatially separated prey and habitat types.
Sequence of Sockeye Salmon Type 1 and 2 Growth Hormone Genes and the Relationship of Rainbow Trout with Atlantic and Pacific Salmon
Authors: Devlin Robert H.
Published: October 2008

Two types of growth hormone genes have been isolated from sockeye salmon (Oncorhynchus nerka) and their complete nucleotide sequence determined. The genes encode proteins of 210 amino acids and show considerable similarity to growth hormones characterized in other salmonids and fishes. The two genes presumably arose from a gene duplication event that generated the tetraploid condition in salmonids and are highly conserved in their coding regions. The sequences have diverged approximately 18% in noncoding regions since the gene duplication event and show numerous deletions and/or insertions. Isolation of these two genes from a Pacific salmon allows comparison of their sequences to growth hormone genes characterized from rainbow trout and from Atlantic salmon. The results indicate that rainbow trout is more similar to Pacific than to Atlantic salmon and suggest that Atlantic salmon diverged from Pacific salmonids at a time when sockeye and rainbow trout were part of a common breeding population. These results support the recent reclassification of rainbow trout from the genus Salmo to Oncorhynchus.
Bias Correction of Rockfish School Cross Section Widths from Digitized Echo Sounder Data
Authors: Kieser R. , Mulligan T. J. , Richards Laura J. , Leaman B. M.
Published: October 2008

The image of a fish school on an echogram represents a cross section through the actual three-dimensional school. Measurement of the size of this cross section, specifically the cross section width (or horizontal distance at a given depth), can be useful for further analysis of biomass or for species recognition. However, the measurement of fish school cross section widths from an echogram can be severely biased when the school dimensions are close to the dimensions of the transducer beam pattern. This is a particular problem for species that form small schools, especially in deep water. Using characteristics of the acoustic beam and measurements of both single fish and of school cross section widths, we developed a bias correction method. Corrected cross section widths of rockfish (Sebastes spp.) schools in our study area ranged from 70 m down to the dimensions measured for single fish and averaged less than 50% of the uncorrected measurements.
Association of ruthenium complexes [Ru(bpy)3]2+or [Ru(bpy)2(Mebpy-py)]2+with Dawson polyanions α-[P2W18O62]6–or α2-[FeIII(H2O)P2W17O61]7–
Authors: Ruhlmann L , Costa-Coquelard C , Hao J , Jiang S , He C , Sun L , Lampre I
Published: October 2008

The formation of electrostatically linked complexes between [Ru(bpy)3]Cl2or [Ru(bpy)2(Mebpy-py)](PF6)2and (TBA)6α-[P2W18O62] or (TBA)5K2α2-[FeIII(H2O)P2W17O61] in solution were studied by steady-state absorption and luminescence spectroscopy. The stoichiometry and global association constants of the formed complexes were obtained by the Job method. The formed complexes were characterized by1H and31P NMR spectroscopy and their electrochemical properties compared to the precursor compounds were investigated by using the cyclic voltammetry method.Key words: electrochemistry, polyoxometalate, ruthenium complex, electrostatic complex.
Chemoenzymatic synthesis of ring 18O-labeled sialic acid
Authors: Indurugalla Deepani , Bennet Andrew J
Published: October 2008

Methyl 4,6-O-benzylidene-α-D-glucopyranoside was converted into methyl 2-azido-2-deoxy-4,6-O-benzylidene-α-D-altropyranoside via a synthetic route that incorporated two inversions of configuration. Activation of the C-3 hydroxyl group as a triflate ester followed by an SN2 reaction with O-18 labeled benzoate gave, after standard functional group manipulations, 2-acetamido-2-deoxy-D-(3-18O)mannose. Coupling of the labeled N-acetyl-mannosamine with pyruvate was catalyzed by sialic acid aldolase to give ring-oxygen-labeled sialic acid in an overall yield of 11.4% over 10 steps.Key words: N-acetylneuraminic acid, sialic acid oxygen-18, chemoenzymatic.
Solvent-free syntheses of some quinazolin-4(3H)-ones derivatives
Authors: Roopan S Mohana , Maiyalagan T , Khan F Nawaz
Published: October 2008

Solvent-free syntheses of quinazolin-4(3H)-ones were performed by reaction of anthranillic acid with different amides, such as nicotinamide, benzamide, formamide, etc., on montmorillonite K-10. Products were confirmed by FTIR, 1HNMR, and 13CNMR spectroscopic techniques. All synthesized compounds exhibited antioxidant properties and have been compared with standard antioxidant BHT.Key words: quinazolinone, montmorillonite K-10, solvent-free conditions, antioxidant properties.
Synthesis of novel 2-alkyl substituted oleobenzimidazole derivatives using ethylene glycol as solvent
Authors: Hosamani K M , Hiremath V B , Keri R S , Harisha R S , Halligudi S B
Published: October 2008

The objective of this research was to conduct constructive organic chemistry by using ethylene glycol as an efficient solvent and to achieve yields that were comparable to or better than those in other media. The reaction parameters, such as temperature (150–200 °C), density, and reaction time (6 h), have been systematically studied to understand whether ethylene glycol is as an efficient solvent and can have a positive effect on the chemistry with good yields. By tuning the parameters, the yields have been optimized to around 70%-80%. Thus, a new class of 2-alkyl substituted oleo-benzimidazole derivatives have been synthesized and characterized by FTIR, 1H NMR, 13C NMR, MS, and elemental analysis.Key words: oleochemistry, ethylene glycol, oleo-benzimidazole derivatives, unusual fatty acids.
Copper-catalyzed one-pot synthesis of benzimidazole derivatives
Authors: Sharghi Hashem , Hosseini-Sarvari Mona , Moeini Fatemeh
Published: October 2008

A simple, efficient, and environmentally benign method has been developed for the synthesis of 2-substituted benzimidazoles through a one-pot reaction of phenylenediamines with aryl aldehydes in excellent isolated yields under mild conditions using Cu(II) complex as the selective, recyclable, and heterogeneous catalyst at ambient temperature. The Cu(II) complex as a heterogeneous catalyst can be reused in further catalytic reactions, and it was found that its activity remained largely unchanged for eight successive runs. No metal-complex leaching was observed after the consecutive catalytic reactions. The salient features of this method include mild conditions, high yields, simple procedure, and good recovery and reusability of the heterogeneous catalyst.Key words: benzimidazole, o-phenylenediamine, arylaldehydes, heterogeneous catalyst, N,N-bis (2-hydroxyphenyl)pyridine-2,6-dicarboxamide.
Carborane-carbohydrate derivatives — Versatile platforms for developing targeted radiopharmaceuticals
Authors: Green Andrew E.C , Harrington Laura E , Valliant John F
Published: October 2008

A series of carborane-carbohydrate derivatives were prepared as model platforms for developing targeted radiopharmaceuticals in which a single ligand can be tagged with two different classes of radionuclides. A nido-carborane linked to glucose was synthesized and the cage labelled with a radiometal (99mTc) and a radiohalogen (125I) in good radiochemical yield. The 99mTc-metallocarborane derivative was prepared via microwave-assisted reactions, while the iodinated derivative was prepared using oxidative labelling methods in mere minutes. Fully characterized reference standards were prepared using nonradioactive rhenium and iodine and used to demonstrate that the isolated radioactive compounds were in fact the desired targets. The work reported, which is one of the rare examples of a single ligand system that can be labelled with both radiohalogens and radiometals, forms the basis of a new paradigm for developing targeted radiopharmaceuticals.Key words: carboranes, medical isotopes, technetium-99m, iodine-125, glucose.
A GENERALIZED KINETIC MODEL OF SEDIMENTATION OF POLYDISPERSE SUSPENSIONS WITH A CONTINUOUS PARTICLE SIZE DISTRIBUTION
Authors: BÜRGER RAIMUND , GARCIA ANTONIO , KUNIK MATTHIAS
Published: October 2008

Polydisperse suspensions with particles of a finite number N of size classes have been widely studied in laboratory experiments. However, in most real-world applications the particle sizes are distributed continuously. In this paper, a well-studied one-dimensional kinematic model for batch sedimentation of polydisperse suspensions of small equal-density spheres is extended to suspensions with a continuous particle size distribution. For this purpose, the phase density function Φ = Φ(t, x, ξ), where ξ ∈ [0, 1] is the normalized squared size of the particles, is introduced, whose integral with respect to ξ on an interval [ξ1, ξ2] is equivalent to the volume fraction at (t, x) occupied by particles of that size range. Combining the Masliyah–Lockett–Bassoon (MLB) model for the solid-fluid relative velocity for each solids species with the concept of phase density function yields a scalar, first-order equation for Φ, namely the equation of the generalized kinetic theory. Three numerical schemes for the solution of this equation are introduced, and a numerical example and an L1 error study show that one of these schemes introduces less numerical diffusion and less spurious oscillations near discontinuities than the others. Several numerical examples illustrate the simulated behavior of this kind of suspensions. Numerical results also illustrate the solution of an eigenvalue problem associated with the equation of the generalized kinetic theory.