bluuebunny/crossref_metadata_2025 huggingface dataset:
Wave Effects in the Upper Ocean
Authors: Qiao Fangli , Huang Chuan Jiang
Published: April 2017

Ocean surface waves can regulate the vertical mixing process of the upper ocean through wave breaking and wave‐turbulence interaction, and induce other motions including the Stokes drift and Langmuir cells. In ocean circulation models, surface waves reduce the sea surface temperature (SST) and increase the subsurface temperature, thereby deepening the upper ocean mixed layer and sustaining a reasonable seasonal thermocline in the summertime. In atmosphere–ocean‐coupled models, in contrast, surface waves affect the SST mainly
via
strong atmosphere–ocean coupling especially in the equatorial oceans. Surface waves decrease the SST in the eastern basin and increase it in the western basin, which contribute to the seasonal cycle and interannual variation of the SST. On the other hand, surface waves can modify currents and circulations of the upper ocean
via
wave‐induced strong mixing and Stokes drift. In the coastal and shallow seas, surface waves affect significantly sediment distribution and resuspension and modify the turbidity of the sea water and the seabed form. The combined effects of wave and tidal mixing contribute to sustain typical temperature profiles in the coastal regions.
Internal Waves
Authors: Jones Nicole L. , Ivey Gregory N.
Published: April 2017

Internal waves are a ubiquitous feature in the ocean. They are of considerable importance in the marine environment as they can both create currents and drive turbulent ocean mixing. Nonlinear internal waves (NLIWs) or solitons induce large vertical displacements of constant density (isopycnal) surfaces of O(100 m) and strong horizontal velocities of O(1–2 m/s) as they propagate. Such large displacements and velocities, in turn, affect nutrient mixing and biological productivity, sediment resuspension, the propagation of acoustic waves, and marine and offshore engineering operations. As NLIWs are potentially hazardous to subsea oil and gas operations, the ability to predict the occurrence and arrival of these waves is necessary for both cost‐effective operation and safety. Despite the considerable body of knowledge about these waves, the prediction of NLIWs remains a very challenging issue and the subject of ongoing research. This article first discusses the theory of internal waves. It then focuses on the generation, propagation, and dissipation of internal tides. Finally, it considers the implications of internal tide dynamics for engineering design and operation in the offshore environment.
Phase‐Resolving Wave Modeling
Authors: Chalikov Dmitry
Published: April 2017

Phase‐resolving modeling of sea waves is the mathematical modeling of surface waves including explicit reproduction of the sea surface and velocity field evolution. The general approach is based on equation of potential motion with a free boundary. Conformal transformation of coordinates is the most effective method of solution of two‐dimensional (
x–z
) periodic problem. For three dimensional models, several different approaches have been developed: boundary integral equation method (BIEM), method based on expansion of velocity potential in a vicinity of surface [high order spectral method (HOSM)], and method based on direct solution of three‐dimensional equation for velocity potential. These methods do not compete with each other because all of them have their advantages. The brief descriptions of each method are given as well as the examples of theirs applications. The investigations of nonperiodic problems are based on a direct solution of equation for velocity potential. The methods of including in the models of algorithms for parameterization of energy input and dissipation are discussed.
Delivery Trials
Authors: van den Boom Henk
Published: April 2017

Ships are subjected to delivery trials to assess their performance and to evaluate this against the regulatory requirements and the specifications in the new building contract. Depending on the ship type, delivery trials comprise speed/power performance as well as more detailed characteristics such as cavitation, hull‐pressure fluctuations, and noise and vibration. Procedures for trial conduct, measurements, and analysis to derive at reliable results acceptable to all parties involved are described.
Statistical and Theoretical Prediction Methods
Authors: van Hees Martin T.
Published: April 2017

In this article, the basic hydrodynamic concepts of ship resistance and propulsion are introduced with a focus on power prediction in the early stages of design. The historical developments in ship performance prediction and the role of methodical series of ship hulls and propellers in power prediction are discussed in detail. Ship propulsion is separated from its basic components, and hull geometry aspects that are relevant to resistance and propulsion are introduced. Specific attention is paid to the developmental approach toward statistical prediction methods, their application domain, and their limits. Finally, the application of these methods within the daily practice of ship design and how to use proprietary model test and sea trials data in order to improve prediction accuracy are discussed.
Maneuvering Experiments
Authors: Yasukawa Hironori
Published: April 2017

This article describes the experimental techniques used to predict ship maneuvering including model captive, model free, and full scale. Full‐scale trials are conducted to confirm the performances of a new ship and to check machineries and equipment onboard at the final stage of the building. Procedures of three trials for the turning, zigzag, and stopping tests are explained in detail with relation to important performances including course keeping, turning, and stopping abilities. The advantage of free‐running model tests is to be able to predict the full‐scale ship maneuverability directly from the test results. The spiral and the reversed‐spiral tests are described together with the special features of course stable and unstable ships. In the captive‐model tests, the model that is restrained to the testing device through the force balance is enforced to make predetermined motions, and the hydrodynamic forces acting on the model in the motions are measured. Measured data are analyzed on the basis of the motion equations together with the mathematical models of hydrodynamic force representations. Testing facilities and data analyses with respect to a rotating‐arm or circular‐motion and planar‐motion‐mechanism tests are explained.
Numerical and Hybrid Prediction Methods for Ship Resistance and Propulsion
Authors: Raven Hoyte C.
Published: April 2017

This article reviews computational methods to predict the required propulsion power and propeller rotation rate of a ship at given speed. RANS (Reynolds‐averaged Navier–Stokes) methods for predicting the full‐scale viscous free‐surface flow around the ship and the resistance are described, and the numerical uncertainty and comparison error of current methods is assessed. Today, for model scale resistance both can be limited to a few percent with good codes and relatively dense grids; however, more attention is desired for appended ship hulls and effects of hull roughness. Methods to compute the propeller operation behind the ship are described; RANS methods coupled with potential‐flow propeller models and fully viscous approaches using sliding interfaces. Here, less experience is available and computed results show larger deviations. Progress is desired as the present prediction accuracy seems not generally sufficient and the reliability is still less than that of predictions based on model tests.
Dynamic Positioning
Authors: Perez Tristan
Published: April 2017

Ship and mobile offshore unit operations require accurate positioning. To date, it is difficult to conceive of these operations without ship‐motion control. This brief article describes the main characteristics and the design principles associated with dynamic positioning (DP), a motion control technique that uses feedback control to achieve vessel position and heading regulation by means of the propulsion system. This article reviews the basic architecture of a DP system and outlines the estimation and control design strategies commonly used. It also discusses the requirements of reliability and safety for different operations.
Historical Development of the Offshore Industry
Authors: Schmidt Victor A. , Crager Bruce , Rodenbusch George
Published: April 2017

The oil and gas industry finds and develops offshore oil and gas fields in three major stages: exploration, drilling, and production. Specialized engineering is required and has been applied throughout each of these stages resulting in the industry's steady advance into deeper water and more challenging environments. The advances in engineering are best seen in the structures and technologies that have been applied in the vessels designed for use on and in the water, in the new materials developed to meet harsher conditions, and in the control systems developed to guide the flow of fluids from deep in the earth, through the water column, and into the platforms and floating production systems that gather and process the production, so it can be sent to market. The engineering challenges continue to evolve, and the solutions that are developed set the stage for industry's next advance into the ocean's depths.
Ice Mechanics and Structures
Authors: Stössel Achim
Published: April 2017

Icebergs and sea ice constitute a major hazard to marine and offshore operations. This contribution is to provide a brief overview on the main features and issues associated with marine ice, in particular sea ice, both from the practical perspective of navigating through ice and from the viewpoint of its role as a physical component in the Earth's climate system. In terms of ice structures, thermodynamically grown level ice is principally different from dynamically (mechanically) formed pressure ridges. The latter constitute major obstacles for navigation. For easy navigation, ship routing follows open water within sea ice (leads and polynyas). From the climate system perspective, these are major sites of air–sea interaction and deep‐ocean ventilation. Sea ice is routinely being monitored through satellite remote sensing, products of which are used for ice forecasting as well as for verification of large‐scale numerical models used for climate studies. As a result of fossil fuel burning, Arctic sea ice is trending downward such that the Arctic Ocean will become more accessible in summer and fall over the next decades. Even though the fraction of multiyear ice is expected to decrease, winter and spring conditions will presumably remain severe throughout this century.
Acoustic Emission Techniques and Application
Authors: Rogers Len
Published: April 2017

This article focuses on in‐service acoustic emission (AE) monitoring for detection of active cracks and damage evolution in structures and machinery. When combined with strain monitoring and the latest developments in fracture mechanics analysis, it is a powerful tool for fatigue crack detection and through life damage assessment. Examples are given of (i) in‐service global AE surveillance of node joints in a floating production platform and major segment of a ship's hull and (ii) bearing condition monitoring in marine azipod propulsors. Also covered briefly is the detection of onset of cavitation erosion in ship rudders and location of secondary barrier leakage in LNG cargo tanks. New analytical software for modeling fatigue crack growth and the associated acoustic emission is described, based on the consolidation of classical fracture mechanics and particle wave mechanics. Consideration is given to the maximum acceptable defect size and the minimum detectable defect size. In nondestructive testing (NDT), defect determination and the evaluation of its significance on a structure are separate issues, whereas with acoustic emission monitoring they are interrelated by the very nature of the phenomenon. As acoustic emission monitoring relates to crack growth, a minimum amount of growth is necessary for crack detection and evaluation purposes, which considers the stress level and the rate of crack growth steps. These factors determine the required duration of monitoring to achieve the specified “detectability” for the test. The detectability decides the sensor spacing and duration of monitoring for reliable crack detection, location, and evaluation purposes. Important additional information for fatigue structural damage assessment and crack life prediction is the nominal cyclic strain at key locations in the structure. These aspects are covered in detail in this article.
Acceptability of Risk
Authors: Tulsyan Bharat
Published: April 2017

Risks and Hazards are part of everyone's daily lives and we manage and accept these risks via the decision we take in our lives. In extreme environments such as offshore and marine conditions, risk management plays an even pivotal role as failures may lead to loss to lives or extensive harm to the environment. This article aims at introducing some basic concepts of risk by discussing examples from our daily lives to techniques such as inherent safe design and ALARP which are being used in the offshore industry for risk assessment and management.
Probabilistic Methods
Authors: Chakraborty Arindam
Published: April 2017

The article provides a high‐level introduction to the probability methods. Various types of randomness were discussed including several numerical methods to generate pseudo random numbers that can be simulated using computer. The article also discusses Bayesian statistics and time series methods. The application of such methods is abundant in the Marine and Offshore engineering.
Port Planning: A Case Study Applied to Iron Ore Port Terminal
Authors: Pereira Newton Narciso , Netto João F. , Botter Rui C. , Medina Afonso C.
Published: April 2017

The concept of port terminal capacity associated with service level and systemic vision that have been used to simulation in logistic projects and commercial planning of organizations. It enables a practical understanding of real system behaviour and the existent bottleneck comprehensions. Then, this paper presents a port terminal capacity evaluation by use of a discrete events simulation model developed in software ARENA. This model enables to determinate the service level to an iron ore port terminal and identify of practical way the operational bottleneck.
Liquid Bulk and Oil Terminals
Authors: Lun Yun H. Venus , Zhu Wenting
Published: April 2017

Oil globally persists as the leading energy source in terms of global energy consumption with a usage rate of 32.6% compared to all of the other energy sources, such as natural gas, hydroelectricity, coal, nuclear energy, and renewables. Oil dominates in maritime shipping in terms of volume among all main types of liquid bulk cargo including chemicals, gas, and oil. 2826 million tons of oil products were carried using tankers as part of the seaborne trade in 2014. Maritime oil transportation, thus, plays a critical role in the moving of this energy source throughout the world. This article focuses on maritime oil transportation. After a preliminary discussion on liquid bulk cargo, the demand for oil transportation and its supply are discussed, respectively. The characteristics, operation process, and relevant safety guidelines of oil terminals, which are designed for loading, unloading, storing, and transferring of oil, are also presented.
Transport Modes and Intermodality
Authors: Hilmola Olli‐Pekka
Published: April 2017

There is a growing concern and global awareness that transportation sector and transportation chains need to considerably decrease their environmental load. All different parties of transport sector, whether it is consumer or business customer, have used to have short lead times, high delivery precision, and valuable services offered by reasonable or cheap prices. However, most of this comes with cost, and that is increasing the dependency on diesel oil and increasing amount of global CO2emissions. In this article, intermodal transport solutions in general are reviewed to illustrate remedies to current situation. Both continental and shorter distance hinterland transportation chains are being reviewed. Special focus is given for railway sector, which plays a key role in the oil independent and CO2neutral transportation chains. As this article illustrates, oil supply globally is tight and consumption is increasing in emerging markets, like China and among major oil producers. In addition, in some areas, like Europe Union, domestic oil supply has dramatically declined after early 2000, illustrating case for peak oil theory.
Dry Ports and Logistics Platforms
Authors: Roso Violeta , Andersson Dan
Published: April 2017

A dry port is an inland intermodal terminal connected to a seaport by rail where customers can leave/pick up their standardized units, as if directly at/from a seaport, and get access to a variety of value‐adding services. A dry port is a special kind of inland terminal, which can be described as a type of logistics platform. There is a common understanding that the successful implementation of a dry port lowers congestion and environmental impact through modal shift; however, the benefits for the actors of the transport system can include other aspects, such as increase in seaports' terminal capacity and productivity, regional development, and better customer service. The development of a dry port includes three phases: the pre‐phase, the start‐up phase, and the growth phase. There are a number of factors that influence the implementation of a dry port, one being the cooperation between the actors of the transport system, and in the future, the inclusion of different value‐added services could become an important factor. As a response to the challenges facing the transport sector, and in particular ports and their hinterlands, the dry port concept will continue to grow.
Marine Gearboxes
Authors: Song Yuzhong , Shibata Yukihisa
Published: April 2017

This article first explains the purpose to use gearboxes in ship propulsion driving chain and type of marine gearboxes. Then, typical failure modes of marine gears are described. Finally, an example of strength evaluation of marine gears is given.
Machinery Loading and Protection
Authors: Smith Andrew
Published: April 2017

Ships operating in Polar regions, or the Baltic Sea, will be subjected to harsh environmental conditions; namely low temperatures and external loading. The prime area of concern is the external loading on the propeller from operating in ice. Ice properties vary dependent on the region and time of year of operation. The design of the propeller, and the shaft line has to accommodate the additional loading without catastrophic failure such as to immobilise the ship endangering the personnel. Low temperatures are important in designing the machinery support systems.

This article gives the reader an overview of the current requirements based on extensive research such that risk of failure is minimised.
Introduction—What Makes a Warship?
Authors: Pawling Rachel J.
Published: April 2017

Warships are perhaps the ultimate service vessels, representing small, mobile pieces of sovereign territory utilized to carry out a range of tasks at sea. Government ownership and operation makes warship design a complex sociotechnical problem, as the key objective will be changing over the span of the procurement process itself. This same uncertainty and changeability continues to affect warships in operation. Warships are designed to fight and, importantly, to take damage and continue fighting. This impacts all levels of design, from overall arrangement to equipment selection and detail design. The internal relationships between systems and components are both complicated and complex.

Warships are highly versatile assets, with not only weapons but also skilled and versatile personnel. Warships are thus engaged in a wide spectrum of operations from peacetime patrol and disaster relief, through times of increased tension to outright conflict, involving such tasks as amphibious operations and antisubmarine warfare. Maritime forces vary worldwide in terms of their nomenclature, structure, and capabilities, and similarly the classification and categorization of warships is a difficult task. Warships can generally be classified by size and primary role, and general examples of the various categories are provided.
Warship Design
Authors: Andrews David
Published: April 2017

This article addresses the unique nature of warships and their design processes and driving issues. The characteristics that make surface warships distinct are outlined (submarine design is covered in a separate chapter). This is followed by discussion of the issues particular to warship design, as an exemplar of the design of physically large and complex systems. Aspects such as their diversity, autonomy, mobility, multirole capability, and the overarching political nature of their acquisition process are highlighted. Major general design issues are addressed under the following headings: speed, stability, seakeeping, strength, and style, where for warships there are distinct drivers, when compared to most commercial shipping. The issue of integrating complex combat systems (including sensors and communication systems as well as weapons), alongside the human factors, concerns of accommodating and enabling large numbers of personnel to operate and live in relatively small spaces for long periods is seen as a further complication in design.

The article addresses the warship design process with a particular emphasis on the crucial early stages of the concept phase, which is seen to be quite unlike commercial vessels in being particularly extensive and protracted. The article concludes by addressing specialist naval vessels, such as aircraft carriers and amphibious warfare vessels, before looking at possible future trends in warship design. Two particular potential developments, those of directed energy weapons and all electric powered warships, are considered.
Safety of Risers, Pipelines, and Subsea Facilities
Authors: Bai Yong , Bai Qiang
Published: April 2017

The exploration and production of oil and gas resources include a variety of risks, which, if not adequately managed, will have a potential to result in a major incident and hazard. Subsea risers, pipelines, and subsea facilities are the main parts of subsea production system. The safety of the system involves all procedures of the field development of subsea production system in the design, manufacture, installation, and operation. The equipment reliability of exploration and production is one of the control factors of risk control, safety, production availability, and maintenance costs.

This article presents a recommended systematic risk management and further describes a methodology of analyzing subsea risers, pipelines, and subsea facilities to improve the reliability of system design and reduce the risk and operating expense using reliability engineering tools. It also includes examples of pipeline risk assessment, including qualitative and quantitative assessments.
Safety of Dynamic Positioning
Authors: Haugen Odd I. , Smogeli Øyvind R.
Published: April 2017

In the context of dynamic positioning (DP), loss of position and/or heading, meaning that the vessel no longer is capable of maintaining its desired position, is the most serious safety breach.

Loss of position and/or heading may result from a drive‐off or drift‐off. A drive‐off is considered the most dangerous situation, where the thruster forces the vessel off position. A drift‐off occurs if the weather forces drive the vessel off position, usually due to lost thrust capacity.

Safety of dynamic positioning (DP safety) relies upon system aspects such as equipment and component selection, design, architecture, functionality, integration, and verification. In addition, operational planning and procedures, training of personnel, company safety policies, and finally local governmental rules and regulations including the enforcement of those also contribute to DP safety. Although all these aspects are important to the overall safety of the DP, this article will focus on the system design and architecture, system functionality, and finally system verification.

DP system safety design elements like redundancy and grouping of components into redundant groups, independence, and interfaces to external components will be discussed, including error detection and handling principles.

Verification regimes implemented by the class societies, failure mode and effect analysis companies, and independent hardware‐in‐the‐loop testing of control system software are also discussed.
Safe Evacuation and Rescue
Authors: Nwose Gina , Sofyan Stannia
Published: April 2017

Escape, evacuation, and rescue (EER) execution plays a very important role in personnel safety in an offshore environment. EER facilities such as lifeboats, personal protective equipment (PPE), marine radio, and so on, are required to be provided on offshore installations to help personnel onboard these installations evacuate safely, should the need arise. In order to use these facilities as intended, offshore installations typically have documented procedures for emergency situations. Training programs and frequent drills are also provided to ensure that personnel on an offshore installation are equipped with the knowledge and ability to protect themselves in case of an emergency. This article gives an overview of offshore evacuation and rescue activities, including qualitative and quantitative analyses that can be performed to ensure the adequacy of EER arrangements on an installation, and systems or configurations to be considered for EER to be successful.
Statutory Framework for Safety and Environmental Protection for Offshore Petroleum Operations for the
UK
Continental Shelf
Authors: Roopchand Maxxine
Published: April 2017

A summary of the statutory framework for safety and environmental protection for offshore petroleum operations for the UK Continental Shelf is provided, which includes (i) Basic philosophy and mechanism by which safety and environmental protection are intended to be achieved. (ii) A list of relevant laws and regulations. (iii) Necessary approvals by regulatory authorities through the lifecycle of a typical offshore development project, documents to be prepared to obtain such approvals, and timing and process of said approvals. (iv) Means of law enforcement available to regulators. (v) List of provisions contained within the laws and regulations specifically addressing safety and environmental hazards in the operations of facilities in remote sea areas.
Topsides Facilities Design
Authors: Knoll David , Baxter Gail
Published: April 2017

Topsides facilities design for offshore platforms requires integration with a broad range of disciplines to ensure a safe and functional system for hydrocarbon production. The major issues related to the topsides configuration selection and design are discussed in this article. The physical interface with the supporting substructure platform and the functional interface with other design disciplines dominate the general topsides configuration selection. Design load cases are selected based on operational requirements and environmental conditions. The effects of fabrication and integration activities on the topsides design, structure analysis, and a range of design issues are summarized.
Jack‐Up Risk and Reliability
Authors: Frieze Paul A. , Morandi Alberto
Published: April 2017

Jack‐up risk and structural reliability studies from the late 1980s and onward are critiqued. They are few in number, particularly risk assessments, and of those available, the findings are presented in incompatible formats making direct comparisons challenging. Notwithstanding, valuable trends are identified. Early reliability analyses are found to ignore the possibility of windward leg uplift, which has a significant effect on the outcome. Few component reliability results are reported and although more system results are found, the modeling differences are significant making comparisons difficult.
Naval Architecture
Authors: Sen Debabrata
Published: April 2017

This article provides fundamental naval architectural aspects of floating platforms. Naval architecture is primarily concerned with weight and buoyancy, hydrostatic equilibrium and stability in both intact and damaged conditions, standards of stability, and dynamic response characteristics under environmental conditions in which these platforms are required to operate. Considering the wide variety of floating platforms with different arrangements of mooring lines, risers, and other constraints, all of these topics including basic hydrostatic stability aspects and in particular evaluation/assessment of the dynamic behavior under the prevailing wave, current, and wind conditions are vast subjects by themselves. Here, only a very basic overview of hydrostatic stability and some preliminary observations on dynamic response characteristics for different floater types are discussed, details of which will be available in the other sections in this volume.
Tension Leg Platform (TLP)
Authors: Muehlner Edmund
Published: April 2017

Tension leg platforms (TLPs) are floating structures moored to the seabed by multiple vertically arranged tension members calledtendons. TLPs are mainly used as production and drilling platforms for offshore oil and gas field developments. Since the first TLP was put into service in the North Sea in 1984, a total of 26 TLPs have been installed in water depths ranging from 147 to 1425 m. TLPs are currently not considered viable beyond about 1800 m water depth due to the size and cost of the tendon system required for deeper water. Tendons are kept under tension by excess buoyancy of the hull. Their stiffness restrains the heave and pitch motions of the platform to a large extent. Due to the restrained heave and pitch motions, the main well control valves (i.e., the production trees) can be located on the platform. For most other floating platforms, the production trees have to be located on the seabed.
Buoy Technology
Authors: Mazallon Julien
Published: April 2017

The catenary anchor leg mooring (CALM) buoy is a mooring system suitable for the open sea, used to either load a tanker from shore and/or unload its cargo to shore. CALM buoys have been widely used since the 1950s as a cost‐effective alternative to jetties fitted with rigid loading arms.

The main purpose of this article is to give the reader a general overview of the offloading buoy technology. Buoys used in deepwater application and their specific engineering challenges are also briefly covered.

The article starts with the historical background and key principles of this technology. Then, further to an overview of the design methodology in use, a detailed description of the system is given. The technical differentiators of loading buoys used in harsh environment and nonstandard applications (liquefied petroleum gas, slurry, viscous or waxy products) are also explained.

To conclude, a review of the technological evolution and what the industry should expect as future trend is presented.
Structural Integrity Management (
SIM
): Offshore Structures
Authors: O'Connor Pat
Published: April 2017

Structural integrity management (SIM) is an ongoing life cycle process for ensuring the continued fitness‐for‐service of offshore structures. Structural integrity can be defined as the ability of an asset to perform its required function effectively and efficiently, in accordance with the requirements and assumptions made in design, whilst protecting health, safety, and the environment. SIM is a four‐step process around data, evaluation, strategy, and program operating within a management framework to ensure owner commitment, with defined roles and responsibilities and competencies of all parties involved. SIM improves operational effectiveness by enhanced HSE performance and improved business returns through increased availability of the facility and provides the opportunity to adopt risk principles for developing SIM strategies. It is important to note that the benefits resulting from SIM should not be available without the owner/operator's commitment to the SIM process for the life of the structure. In other words, the management framework requirements must be verified and committed to.
Ultimate Strength Analysis
Authors: Holmas Tore , Amdahl Jørgen
Published: April 2017

Strength (resistance) has historically been measured by experiments, either controlled in laboratories or by trial‐and‐failure. For full‐scale offshore structures, however, numerical tools have to be used.

Prediction of the ultimate strength is often uncertain. It is recommended to start with simple models and establish lower‐ and upper‐bound capacities using the sub‐models. If necessary, more detailed and complex models are introduced later when the governing parameters are identified.

The ultimate capacity of a structure depends on the chosen acceptance criteria and safety factors.
Overview of Offshore Drilling Technologies
Authors: Zulqarnain Muhammad , Fike Rivers
Published: April 2017

The world's ever increasing energy demand has lead oil and gas companies to explore hydrocarbons in complex and technologically challenging offshore environments. The rapid variations in regional geological settings and severe environmental conditions add complexities to these operations. The petroleum industry has successfully developed and implemented technologies to drill offshore wells, to gain access to these additional energy resources. Technological improvements have enabled drilling complex well patterns, such as directional and horizontal drilling and extended reach drilling, which allow development at a greater distance from the drilling rig with small environmental foot print.

Similarities exist between the construction of offshore wells and the rotary drilling process used for drilling onshore wells. The main differences exist in the type of drilling rig and modified procedures adopted to drill in complex situations. As wells are drilled in progressively deeper waters, the cost to carry out drill‐in operations increases. High rig rates, transportation, and service cost contribute to daily operational expenditures, which sometimes exceeds $1 million per day. Therefore, the size of the hydrocarbon reservoir that can be developed should justify the economics of the project.
Regulations Governing Offshore Oil and Gas Operations
Authors: Zulqarnain Muhammad
Published: April 2017

The extraction and transport of hydrocarbons from offshore environments is a hazardous activity due to the operational complexities and hostile conditions. The industry and the regulatory authorities must ensure to keep a balance between risk and project economics. After the Deepwater Horizon accident in 2010, there has been growing focus in many countries, especially in the U.S. on safety and environmental aspects of offshore oil and gas operations. New regulations governing oil and gas offshore operations have been introduced. The recent US regulations have started using a hybrid approach of prescriptive as well as performance based by the introduction of Safety and Environmental Management Systems (SEMS). This article provides a brief overview of few selected regulations relevant to offshore oil and gas operations during the entire life cycle of the project.
High Speed Craft
Authors: Keuning Lex , Ligtelijn Do
Published: April 2017

The article describes the fundamentals of several types of high speed craft, followed by a review of aspects of the prediction of the resistance of high speed craft that are different from what is used for conventional displacement ships. This concerns model testing, statistical prediction methods, series data and more advanced computational methods. In a similar way, aspects concerning propulsion and cavitation testing are reviewed.
Shipboard Condition Monitoring
Authors: Lunt Stuart
Published: April 2017

Oil condition monitoring forms a vital part of integrated machinery health management programs. Good lubrication is essential for the well‐being of equipment, with safe and reliable operation dependent on the condition of the oil. Recently, a shift from time‐based maintenance to that of condition‐based maintenance (CBM) has strengthened the need for reliable data on chemical changes to the oil and information on the presence of contaminants and wear metals in the oil. Together with operational parameters, these data enable informed decisions to be made with regard to maintenance interventions or to respond to abnormal operating conditions. Periodic sampling and offline laboratory analysis has been the traditional approach to land‐based CBM. However, this is clearly inadequate for shipboard maintenance due to the delay incurred between sampling at sea to that of analysis on shore. This article reviews the various aspects of shipboard condition monitoring options ranging from simple test kits to permanent sensor installations. A practical example involving cylinder lubrication oil is given to illustrate the benefit of multiparameter testing for precise diagnostics.
Supply Chain Risk and Vulnerability in Maritime Ports and Terminals
Authors: Talas Risto , Menachof David , Harris Kelvin
Published: April 2017

The article is concerned with issues of risk and vulnerability in supply chains with focus on a port, beginning with an examination of definitions of risk and supply chain risk. The methodology employed to assess risk and vulnerability is drawn from the engineering literature: failure modes and effects analysis (FMEA). The FMEA process is defined, followed by a description of data sources required. The results of the data analysis not only show the types of risk pertinent to a port but also prioritize them for management to gain a better understanding of the threats to their port.
The Rise of Achaemenid Persia, 550–525BC
Authors: Brosius Maria
Published: April 2017

Under the leadership of Cyrus, the Persians of the Iranian plateau overthrew their Median overlords in the mid‐sixth centurybc. Cyrus rapidly extended his conquests into Asia Minor, where he subjugated the kingdom of Lydia under its ruler Croesus, before returning to Mesopotamia, where he captured Babylon. Cyrus died on campaign against northern tribes but his successor, Cambyses, continued Persian expansion by conquering Egypt in the 520 s.
The First Punic War and After, 264–237BC
Authors: Eckstein Arthur
Published: April 2017

The First Punic War (264–241bc) was a series of land and sea campaigns fought between the Roman republic and Carthage, primarily for the control of Sicily. Rome, traditionally a land power, was forced to contend with Carthage for control of the sea; building and rebuilding several fleets, Rome won a series of naval victories that eventually established it as the leading maritime power in the Mediterranean. By 241, both sides were exhausted, and Carthage agreed to evacuate Sicily in return for peace; Rome was in no state itself to extract further concessions. In the aftermath of the conflict, the mercenary forces of Carthage rebelled; initially refusing to take advantage of the chaos, the Senate later intervened to seize Corsica and Sardinia. An impotent Carthage was forced to seek new opportunities in Spain, leading to new tensions and ultimately a new war with Rome.
Alaric and Italy, 401–410
Authors: Humphries Mark
Published: April 2017

In 401 the desire of Alaric to secure territory for his Gothic followers led him to try his luck in Italy. There he was eventually repulsed by Roman forces under Stilicho, who also dealt with a substantial tribal invasion under Radagaisus in 406. Stilicho, however, was unpopular and his elimination through court intrigues in 408 facilitated a fresh attempt by Alaric. Negotiations with Emperor Honorius proved futile and, in frustration, Alaric eventually captured and sacked Rome itself in 410. Alaric died soon after and his followers, still searching for a safe home, moved to southern Gaul.
Theoderic and the Goths, 476–492
Authors: Whitby Michael
Published: April 2017

As the Hunnic federation disintegrated in the late 450 s, various tribal groups that had previously been largely invisible came to the fore. From the complicated rivalry between these tribes, a group led by the Amal family triumphed so that in the early 480 s Theoderic the Amal gathered most other groups under his control and posed a serious challenge to Emperor Zeno in Constantinople. Zeno resolved this by encouraging Theoderic to move to Italy, to confront Odoacer, who had deposed the last Roman emperor in 476 and had subsequently been controlling the peninsula from Ravenna. Theoderic's success established Ostrogothic control over Italy.
Earth‐Abundant Chalcogenide Photovoltaic Devices with over 5% Efficiency Based on a Cu2BaSn(S,Se)4 Absorber
Authors: Shin Donghyeop , Zhu Tong , Huang Xuan , Gunawan Oki , Blum Volker , Mitzi David B.
Published: April 2017

In recent years, Cu2ZnSn(S,Se)4 (CZTSSe) materials have enabled important progress in associated thin‐film photovoltaic (PV) technology, while avoiding scarce and/or toxic metals; however, cationic disorder and associated band tailing fundamentally limit device performance. Cu2BaSnS4 (CBTS) has recently been proposed as a prospective alternative large bandgap (~2 eV), environmentally friendly PV material, with ~2% power conversion efficiency (PCE) already demonstrated in corresponding devices. In this study, a two‐step process (i.e., precursor sputter deposition followed by successive sulfurization/selenization) yields high‐quality nominally pinhole‐free films with large (>1 µm) grains of selenium‐incorporated (x = 3) Cu2BaSnS4−xSex (CBTSSe) for high‐efficiency PV devices. By incorporating Se in the sulfide film, absorber layers with 1.55 eV bandgap, ideal for single‐junction PV, have been achieved within the CBTSSe trigonal structural family. The abrupt transition in quantum efficiency data for wavelengths above the absorption edge, coupled with a strong sharp photoluminescence feature, confirms the relative absence of band tailing in CBTSSe compared to CZTSSe. For the first time, by combining bandgap tuning with an air‐annealing step, a CBTSSe‐based PV device with 5.2% PCE (total area 0.425 cm2) is reported, >2.5× better than the previous champion pure sulfide device. These results suggest substantial promise for the emerging Se‐rich Cu2BaSnS4–xSex family for high‐efficiency and earth‐abundant PV.
New and Convergent Synthesis of Osimertinib
Authors: Zhu Guoqing , Wang Xingyan , Wang Feng , Mao Yongjun , Wang Han
Published: April 2017

New and convergent synthetic route of osimertinib is described on a dozen of grams scale. A key cyclization of 1‐(4‐((2‐(dimethylamino)ethyl)(methyl)amino)‐2‐methoxy‐5‐nitrophenyl)guanidine and 3‐(dimethylamino)‐1‐(1‐methyl‐1H‐indol‐3‐yl)prop‐2‐en‐1‐one is adopted to give the 4‐(1H‐indol‐3‐yl)‐N‐phenylpyrimidin‐2‐amine structure. Osimertinib is prepared in 40.4% yield over six steps and 99.1% purity (HPLC). Purification methods of the intermediates involved in the route are also given.
Neurogenesis and pattern separation: time for a divorce
Authors: Becker Suzanna
Published: April 2017

The generation of new neurons in the adult mammalian brain has led to numerous theories as to their functional significance. One of the most widely held views is that adult neurogenesis promotes pattern separation, a process by which overlapping patterns of neural activation are mapped to less overlapping representations. While a large body of evidence supports a role for neurogenesis in high interference memory tasks, it does not support the proposed function of neurogenesis in mediating pattern separation. Instead, the adult‐generated neurons seem to generate highly overlapping and yet distinct distributed representations for similar events. One way in which these immature, highly plastic, hyperactive neurons may contribute to novel memory formation while avoiding interference is by virtue of their extremely sparse connectivity with incoming perforant path fibers. Another intriguing proposal, awaiting empirical confirmation, is that the young neurons’ recruitment into memory formation is gated by a novelty/mismatch mechanism mediated by CA3 or hilar back‐projections. Ongoing research into the intriguing link between neurogenesis, stress‐related mood disorders, and age‐related neurodegeneration may lead to promising neurogenesis‐based treatments for this wide range of clinical disorders. WIREs Cogn Sci 2017, 8:e1427. doi: 10.1002/wcs.1427

This article is categorized under:

Psychology > Memory

Neuroscience > Cognition

Neuroscience > Computation
Cover Image, Volume 6, Issue 3
Authors: Dahmen Nicolaus , Abeln Johannes , Eberhard Mark , Kolb Thomas , Leibold Hans , Sauer Jörg , Stapf Dieter , Zimmerlin Bernd
Published: April 2017

The cover image, Nicolaus Dahmen et al., is based on the Focus Article The bioliq process for producing synthetic transportation fuels, DOI: 10.1002/wene.236.

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The Later Middle Ages
Authors: Collette Carolyn P. , Garrett-Goodyear Harold
Published: April 2017

This substantial anthology of documents offers students of later medieval English literature, society and history a range of interdisciplinary perspectives through which to understand the literary texts from the period 1350-1550. Informed by the latest scholarship and meticulous original research, it includes both classic texts and brings rare materials back into circulation. The documents illustrate and illuminate the languages of medieval England, its books and methods of manuscript production; as well as the diverse richness of the spirituality, chivalry and scientific knowledge that shaped the later medieval world.

Supported by a wide-range of pedagogically-designed tools to help students find their way into the history, literature and culture of the period, The Later Middle Ages: A Sourcebook includes:

- An authoritative introduction outlining key historical events, social and political movements, and literary and cultural ideas of the time

- Informative headnotes, footnotes and section introductions, supporting the material and providing insights into how individual documents aid the reading of major texts

- A timeline and a chronological list of the major literary events of the period

- A comprehensive guide to further reading and useful websites

The Later Middle Ages: A Sourcebook makes available documents that are both important in their own right, and crucial for an understanding of the literary output of the period, challenging boundaries between text and context, literature and history. The rich source material and essential context that this book provides make it an invaluable resource for all students of Medieval Studies.