Modeling and Solving the Liner Shipping Service Selection Problem

DEFF Research Database (Denmark)

Karsten, Christian Vad; Balakrishnan, Anant

We address a tactical planning problem, the Liner Shipping Service Selection Problem (LSSSP), facing container shipping companies. Given estimated demand between various ports, the LSSSP entails selecting the best subset of non-simple cyclic sailing routes from a given pool of candidate routes...... to accurately model transshipment costs and incorporate routing policies such as maximum transit time, maritime cabotage rules, and operational alliances. Our hop-indexed arc flow model is smaller and easier to solve than path flow models. We outline a preprocessing procedure that exploits both the routing...... requirements and the hop limits to reduce problem size, and describe techniques to accelerate the solution procedure. We present computational results for realistic problem instances from the benchmark suite LINER-LIB....

The Liner Shipping Routing and Scheduling Problem Under Environmental Considerations

DEFF Research Database (Denmark)

Dithmer, Philip; Reinhardt, Line Blander; Kontovas, Christos

2017-01-01

This paper deals with the Liner Shipping Routing and Scheduling Problem (LSRSP), which consists of designing the time schedule for a vessel to visit a fixed set of ports while minimizing costs. We extend the classical problem to include the external cost of ship air emissions and we present some...

A matheuristic for the liner shipping network design problem

DEFF Research Database (Denmark)

Brouer, Berit Dangaard; Desaulniers, Guy; Pisinger, David

We present a matheuristic, an integer programming based heuristic, for the liner shipping network design problem. This problem consists of finding a set of container shipping routes defining a capacitated network for cargo transport. The objective is to maximize the revenue of cargo transport...... the available fleet of container vessels. The cargo transports make extensive use of transshipments between routes and the number of transshipments of the cargo flow is decisive for network profitability. Computational results are reported for the benchmark suite LINER-LIB 2012 following the industry standard...... of weekly departures on every schedule. The heuristic shows overall good performance and is able to find high quality solutions within competitive execution times. The matheuristic can also be applied as a decision support tool to improve an existing network by optimizing on a designated subset...

Competitive Liner Shipping Network Design

DEFF Research Database (Denmark)

Karsten, Christian Vad; Brouer, Berit Dangaard; Pisinger, David

2017-01-01

We present a solution method for the liner shipping network design problem which is a core strategic planning problem faced by container carriers. We propose the first practical algorithm which explicitly handles transshipment time limits for all demands. Individual sailing speeds at each service...... leg are used to balance sailing speed against operational costs, hence ensuring that the found network is competitive on both transit time and cost. We present a matheuristic for the problem where a MIP is used to select which ports should be inserted or removed on a route. Computational results...

Competitive Liner Shipping Network Design

DEFF Research Database (Denmark)

Karsten, Christian Vad; Brouer, Berit Dangaard; Pisinger, David

We present a solution method for the liner shipping network design problem which is a core strategic planning problem faced by container carriers. We propose the first practical algorithm which explicitly handles transshipment time limits for all demands. Individual sailing speeds at each service...... leg are used to balance sailings speed against operational costs, hence ensuring that the found network is competitive on both transit time and cost. We present a matheuristic for the problem where a MIP is used to select which ports should be inserted or removed on a route. Computational results...

Single string planning problem arising in liner shipping industries: A heuristic approach

DEFF Research Database (Denmark)

Gelareh, Shahin; Neamatian Monemi, Rahimeh; Mahey, Philippe

2013-01-01

We propose an efficient heuristic approach for solving instances of the Single String Planning Problem (SSPP) arising in the liner shipping industry. In the SSPP a Liner Service Provider (LSP) only revises one of its many operational strings, and it is assumed that the other strings are unchangea...

Liner Shipping Fleet Deployment with Sustainable Collaborative Transportation

Directory of Open Access Journals (Sweden)

Gang Du

2016-02-01

Full Text Available Facing sharp competition in the market for shipping companies, it is necessary to make reasonable and efficient decisions to optimize the container shipping line network so as to improve the shipping efficiency and reduce the transportation cost, as well as to realize the transportation sustainability. Therefore, the liner ship fleet deployment problem with collaborative transportation is proposed in this paper. This problem is formulated as a mixed-integer linear programming model that takes collaborative transportation into consideration. The model includes fixed cost, variable cost, berth cost, transport cost, penalty, compensation cost, and so on. To achieve the sustainable development of collaborative transportation, the shipping companies could make a selection between the internal routes and the external routes to serve each task by comparing the distance between the above routes. A real Asia-Europe-Oceania numerical experiment shows that the proposed sustainable collaborative transportation model can be efficiently solved by C++ calling ILOG CPLEX. Results demonstrate that the optimized shipping line network with sustainable collaborative transportation can improve the service efficiency, as well as the service level of shipping companies.

A greedy construction heuristic for the liner service network design problem

DEFF Research Database (Denmark)

Brouer, Berit Dangaard

is challenging due to the size of a global liner shipping operation and due to the hub-and-spoke network design, where a high percentage of the total cargo is transshipped. We present the first construction heuristic for large scale instances of the LSN-DP. The heuristic is able to find a solution for a real...

Determining Domestic Container Shipping as an Enforcement of Indonesian International Hub Port

Science.gov (United States)

Nur, H. I.; Lazuardi, S. D.; Hadi, F.; Hapis, M.

2018-03-01

According to Presidential Regulation Number 26 year of 2012 about the National Logistics System Development Blueprint, the Indonesian government proposed to build two international hub ports, which were in Port of Kuala Tanjung for the western region and Port of Bitung for eastern region. Therefore, the optimum routes and fleet size are required to support the enforcement of Indonesian International Hub Port. The optimization model is used to obtain the optimum route and fleet by minimizing the total shipping costs, while considering the container demand. The result of analysis obtained that the optimum route and fleet size for the western region of Indonesia were: (1) Kuala Tanjung-Belawan required 15 ships of 1,000 TEU; (2) Kuala Tanjung-Tanjung Priok required 73 ships of 2,500 TEU; (3) Kuala Tanjung- Tanjung Perak required 44 ships of 2,500 TEU. Meanwhile, the optimum route and fleet size for the eastern region of Indonesia consisted of: (1) Bitung-Sorong required 1 ship of 500 TEU; (2) Bitung-Banjarmasin required 3 ships of 500 TEU; and (3) Bitung-Makassar required 1 ship of 1,500 TEU.

The liner shipping berth scheduling problem with transit times

DEFF Research Database (Denmark)

Reinhardt, Line Blander; Plum, Christian E.M.; Pisinger, David

2016-01-01

In this paper speed optimization of an existing liner shipping network is solved by adjusting the port berth times. The objective is to minimize fuel consumption while retaining the customer transit times including the transhipment times. To avoid too many changes to the time table, changes of port...

A matheuristic for the liner shipping network design problem

DEFF Research Database (Denmark)

Brouer, Berit Dangaard; Desaulniers, Guy; Pisinger, David

2014-01-01

, while minimizing the cost of operating the network. Liner shipping companies publish a set of routes with a time schedule, and it is an industry standard to have a weekly departure at each port call on a route. A weekly frequency is achieved by deploying several vessels to a single route, respecting...

A Path Based Model for a Green Liner Shipping Network Design

DEFF Research Database (Denmark)

Brouer, Berit Dangaard; Jepsen, Mads Kehlet; Plum, Christian Edinger Munk

Liner shipping networks are the backbone of international trade providing low transportation cost, which is a major driver of globalization. These networks are under constant pressure to deliver capacity, cost eectiveness and environmentally conscious transport solutions. This article proposes...... a new path based MIP model for the Liner shipping Network Design Problem minimizing the cost of vessels and their fuel consumption facilitating a green network. The proposed model reduces problem size using a novel aggregation of demands. A decomposition method enabling delayed column generation...... is presented. The subproblems have similar structure to Vehicle Routing Problems, which can be solved using dynamic programming. An algorithm has been implemented for this model, unfortunately with discouraging results due to the structure of the subproblem and the lack of proper dominance criteria...

The Costs of Container Transport Flow Between Far East and Serbia Using Different Liner Shipping Services

Directory of Open Access Journals (Sweden)

Rajkovic Radoslav

2015-11-01

Full Text Available Liner shipping is the most efficient mode of transport for goods. International liner shipping is a sophisticated network of regularly scheduled services that transports goods from anywhere in the world to anywhere in the world at low cost and with greater energy efficiency than any other form of international transportation. Liner shipping connects countries, markets, businesses and people, allowing them to buy and sell goods on a scale not previously possible. Today, the liner shipping industry transports goods representing approximately one-third of the total value of global trade. Ocean shipping contributes significantly to international stability and security. Considering the large and constant struggle in the market in terms of competitive pricing of products, a very important and indispensable role represents the container transport with a clear task to define the final price of the product. This paper analyzes the costs of container transport flow between Far East and Serbia, using different liner shipping services, observing the six world’s largest container operators (Maersk Line, Mediterranean Shipping Company, CMA CGM, Evergreen Line, China Ocean Shipping Company and Hapag-Lloyd and inland (truck-rail-river transport corridors. These corridors include distance between selected Mediterranean ports (Koper, Rijeka, Bar, Thessaloniki, Constanta and Serbia. As a result, in this paper is considered a mathematical model that provides a comparative analysis of transportation costs on the different routes. It is observed already existing transport routes and it is also given hypothetical review to the development of new transport routes. The main goal of this research is to provide an optimal route with lowest transportation cost during container transport. Selection of the best route in the intermodal network is a very difficult and complex task. The costs in all modes of transport and the quality of their services are not constant

Regional Hub port development : the case of Montevideo, Uruguay

OpenAIRE

Wilmsmeier, Gordon; Martínez Zarzoso, Inmaculada; Fiess, Norbert

2011-01-01

This paper reflects on port development in Uruguay in an environment of trilateral interport competition. The regional characteristics of port development in terms of their geographical, functional and operational characteristics are discussed by analysing the port system’s evolution. The case of Montevideo as the success or failure of a regional hub port development strategy is analysed in detail. Particular attention is given to the evolution and impact of the liner shipping service network...

Green vessel scheduling in liner shipping: Modeling carbon dioxide emission costs in sea and at ports of call

Directory of Open Access Journals (Sweden)

Maxim A. Dulebenets

2018-03-01

Full Text Available Considering a substantial increase in volumes of the international seaborne trade and drastic climate changes due to carbon dioxide emissions, liner shipping companies have to improve planning of their vessel schedules and improve energy efficiency. This paper presents a novel mixed integer non-linear mathematical model for the green vessel scheduling problem, which directly accounts for the carbon dioxide emission costs in sea and at ports of call. The original non-linear model is linearized and then solved using CPLEX. A set of numerical experiments are conducted for a real-life liner shipping route to reveal managerial insights that can be of importance to liner shipping companies. Results indicate that the proposed mathematical model can serve as an efficient planning tool for liner shipping companies and may assist with evaluation of various carbon dioxide taxation schemes. Increasing carbon dioxide tax may substantially change the design of vessel schedules, incur additional route service costs, and improve the environmental sustainability. However, the effects from increasing carbon dioxide tax on the marine container terminal operations are found to be very limited.

A flow-first route-next heuristic for liner shipping network design

DEFF Research Database (Denmark)

Krogsgaard, Alexander; Pisinger, David; Thorsen, Jesper

2018-01-01

Having a well-designed liner shipping network is paramount to ensure competitive freight rates, adequate capacity on trade-lanes, and reasonable transportation times.The most successful algorithms for liner shipping network design make use of a two-phase approach, where they first design the routes...... different operators are used to modify the network. Since each iteration of the local search method involves solving a very complex multi-commodity flow problem to route the containers through the network, the flow problem is solved heuristically by use of a fast Lagrange heuristic. Although the Lagrange...... heuristic for flowing containers is 2–5% from the optimal solution, the solution quality is sufficiently good to guide the variable neighborhood search method in designing the network. Computational results are reported, showing that the developed heuristic is able to find improved solutions for large...

A path based model for a green liner shipping network design problem

DEFF Research Database (Denmark)

Jepsen, Mads Kehlet; Brouer, Berit Dangaard; Plum, Christian Edinger Munk

2011-01-01

Liner shipping networks are the backbone of international trade providing low transportation cost, which is a major driver of globalization. These networks are under constant pressure to deliver capacity, cost effectiveness and environmentally conscious transport solutions. This article proposes...

Preparations to ship EPICOR liners

International Nuclear Information System (INIS)

Queen, S.P.

1983-06-01

The sampling and analysis of the hydrogen rich atmosphere of the 49 EPICOR II ion-exchange prefilter liners generated in the decontamination of radioactive water at TMI-2 will provide data to ensure safe storage and shipment of highly loaded ion-exchange media. This report discusses the prototype gas sampling tool used to breech the containment of the liners, the tool support equipment for sampling and inerting the liners, and the characterization program used for determining the radiolytic hydrogen generation rates in the liners

Schedule unreliability in liner shipping : Origins and consequences for the hinterland supply chain

NARCIS (Netherlands)

Vernimmen, Bert; Dullaert, Wout; Engelen, Steve

Despite claims by shipping lines that most of their containerships operate on fixed-day weekly schedules, a large survey recently revealed that over 40 of the vessels deployed on worldwide liner services arrive one or more days behind schedule. Broadly speaking, the survey found relatively low

Modeling Liner Shipping Service Selection and Container Flows using a Multi-layer Network

DEFF Research Database (Denmark)

Karsten, Christian Vad; Balakrishnan, Anant

We introduce a new formulation for the tactical planning problem facing container shipping companies of selecting the best subset of sailing routes from a given pool of candidate routes so as to maximize profit. Since most containers are sent directly or transshipped at most twice in current liner...

A service flow model for the liner shipping network design problem

DEFF Research Database (Denmark)

Plum, Christian Edinger Munk; Pisinger, David; Sigurd, Mikkel M.

2014-01-01

. The formulation alleviates issues faced by arc flow formulations with regards to handling multiple calls to the same port. A problem which has not been fully dealt with earlier by LSNDP formulations. Multiple calls are handled by introducing service nodes, together with port nodes in a graph representation...... of the network and a penalty for not flowed cargo. The model can be used to design liner shipping networks to utilize a container carrier’s assets efficiently and to investigate possible scenarios of changed market conditions. The model is solved as a Mixed Integer Program. Results are presented for the two...

Models and Methods for the Design and Support of Liner Shipping Networks

DEFF Research Database (Denmark)

Koza, David Franz

that may substantially change the way liner vessels are operated in the future. The article addresses the establishment of a large-scale liquefied natural gas supply chain along a major trade lane. It analyzes the interaction between long-term investment and operational costs, derives basic decision rules...... route be designed to achieve a well-connected but cost-efficient network? How shall port calls be scheduled and synchronized between shipping routes to offer the most economical and fastest transportation between ports? On which route shall containers be transported, if multiple options exist...

Internationalisation Within Liner Shipping

DEFF Research Database (Denmark)

Prockl, Günter; Kinra, Aseem; Kotzab, Herbert

2018-01-01

, the degree of internationalisation, measured on the basis of sea-oriented operations, differs from that measured according to land-oriented front-end marketing and sales activities. The purpose of this study is to further examine the internationalisation patterns of shipping lines. An examination...... of the front-end activities and the structures of leading container-shipping companies is conducted. The sales office networks of the sector’s 20 largest companies worldwide (by twenty-foot equivalent unit capacity) are analysed as key indicators. The numbers of sales offices are measured by analysing...... the websites of the sample (20 companies), as well as annual reports and other publicly available data sources. The findings show that not all shipping companies are international, by virtue of the industry. While it is difficult to observe differences in the overall patterns of the sales networks at a macro...

Single liner shipping service design

DEFF Research Database (Denmark)

Plum, Christian Edinger Munk; Pisinger, David; Salazar-González, Juan-José

2014-01-01

The design of container shipping networks is an important logistics problem, involving assets and operational costs measured in billions of dollars. To guide the optimal deployment of the ships, a single vessel round trip is considered by minimizing operational costs and flowing the best paying...

Construction experience on PCRV liners at Fort St. Vrain

International Nuclear Information System (INIS)

Cliff, J.O.; Wunderlich, R.G.

1976-01-01

The construction of the steel liners for the Fort St. Vrain prestressed concrete reactor vessel presented many unique problems for which techniques were developed to satisfy the rigid specification requirements. The PCRV cavity liner was fabricated from 1.9cm carbon steel plate. The liners were partially fabricated by Pittsburgh-Des Moines Steel Company at their Pittsburgh manufacturing facility. The liners were then shipped by rail to within approximately five miles of the jobsite and then trucked the remaining distance. The construction techniques, dimensional control, concrete support and testing utilized on the Fort St. Vrain project are presented in detail and demonstrate the flexibility of the PCRV for field construction. (author)

A Study of Market Structure in Liner Shipping Under the Influence of Government Policies

OpenAIRE

Wong, Peter Chi Chung; Bamford, Colin

2012-01-01

The peculiar operational mode and involvement of international carriers\\ud granted liner operators special exemption from Anti-trust regulations\\ud globally. The changes of policy from USA and EU in recent years forbidden\\ud liner operators to form Liner Conference (LC) which seems to possess\\ud oligopoly power in the trade. This paper use the freight rate to verified the\\ud change of Government policies cannot stop the liner operators to form in\\ud their natural formation - Liner Conference.

Liner Service Network Design

DEFF Research Database (Denmark)

Brouer, Berit Dangaard

. The research field of liner shipping network design is relatively young and many open research questions exists. Among others, a unified and rich mathematical model formulating the main characteristics of the business domain has not been clearly described and exact methods for such mathematical models...... management is of great concern to liner shippers as 70-80% of vessel round trips experience delays in at least one port. A novel mathematical model for handling a disruption using a series of recovery techniques is presented as the The Vessel Schedule Recovery Problem. The model has been applied to four real...... is based upon improving the constructed solution by applying an IP model as a large scale neighbourhood to each service in the network. The IP is based on estimating the benefit of inserting and removing port calls within a predefined neighborhood of candidate ports. Furthermore, the heuristic applies...

Solving Hub Network Problem Using Genetic Algorithm

Directory of Open Access Journals (Sweden)

Mursyid Hasan Basri

2012-01-01

Full Text Available This paper addresses a network problem that described as follows. There are n ports that interact, and p of those will be designated as hubs. All hubs are fully interconnected. Each spoke will be allocated to only one of available hubs. Direct connection between two spokes is allowed only if they are allocated to the same hub. The latter is a distinct characteristic that differs it from pure hub-and-spoke system. In case of pure hub-and-spoke system, direct connection between two spokes is not allowed. The problem is where to locate hub ports and to which hub a spoke should be allocated so that total transportation cost is minimum. In the first model, there are some additional aspects are taken into consideration in order to achieve a better representation of the problem. The first, weekly service should be accomplished. Secondly, various vessel types should be considered. The last, a concept of inter-hub discount factor is introduced. Regarding the last aspect, it represents cost reduction factor at hub ports due to economies of scale. In practice, it is common that the cost rate for inter-hub movement is less than the cost rate for movement between hub and origin/destination. In this first model, inter-hub discount factor is assumed independent with amount of flows on inter-hub links (denoted as flow-independent discount policy. The results indicated that the patterns of enlargement of container ship size, to some degree, are similar with those in Kurokawa study. However, with regard to hub locations, the results have not represented the real practice. In the proposed model, unsatisfactory result on hub locations is addressed. One aspect that could possibly be improved to find better hub locations is inter-hub discount factor. Then inter-hub discount factor is assumed to depend on amount of inter-hub flows (denoted as flow-dependent discount policy. There are two discount functions examined in this paper. Both functions are characterized by

Risk assessment for the transportation of radioactive zeolite liners

International Nuclear Information System (INIS)

1982-01-01

The risk is estimated for the shipment of radioactive zeolite liners in support of the Zeolite Vitrification Demonstration Program currently underway at Pacific Northwest Laboratory under the sponsorship of the US Department of Energy. This program will establish the feasibility of zeolite vitrification as an effective means of immobilizing high-specific-activity wastes. In this risk assessment, it is assumed that two zeolite liners, each loaded around July 1, 1981 to 60,000 Ci, will be shipped by truck around January 1, 1982. However, to provide a measure of conservatism, each liner is assumed to initially hole 70,000 Ci, with the major radioisotopes as follow: 90 Sr = 3000 Ci, 134 Cs = 7000 Ci, 137 Cs = 60,000 Ci. Should shipment take place with essentially no delay after initial loading (regardless of loading date), the shipment loading would be only 2.7% higher than that for the assumed six-month delay. This would negligibly affect the overall risk. As a result of this risk assessment, it is concluded that the transport of the radioactive zeolite liners from TMI to PNL by truck can be conducted at an insignificant level of risk to the public

A Branch-and-Price Approach to the Feeder Network Design Problem

DEFF Research Database (Denmark)

Santini, Alberto; Plum, Christian Edinger Munk; Røpke, Stefan

2017-01-01

In this paper we consider the problem of designing a container liner shipping feeder network. The designer has to choose which port to serve during many rotations that start and end at a central hub. Many operational characteristics are considered, such as variable leg-by-leg speeds and cargo...

Risk assessment for the transportation of radioactive zeolite liners

International Nuclear Information System (INIS)

Gallucci, R.H.V.

1982-01-01

The accident risk is estimated for the shipment of two zeolite liners containing radioactive cesium and strontium. Each liner, assumed to hold 68,200 Ci and sealed inside a CNS 1 to 13C, type-B shipping cask, is transported by truck over a 4200-km route. The risk to the population along the route is calculated for potential transportation accidents involving fire, impact, and puncture forces. The total risk is 5.3E-7 man-rem (50-year inhalation dose) and the maximum dose (from the least-likely accident) is 0.7 man-rem. Both estimates are less than 0.1% of comparable risk measures for natural background radiation and spent fuel shipment accidents

A competing risk model for the reliability of cylinder liners in marine Diesel engines

Energy Technology Data Exchange (ETDEWEB)

Bocchetti, D. [Grimaldi Group, Naples (Italy); Giorgio, M. [Department of Aerospace and Mechanical Engineering, Second University of Naples, Aversa (Italy); Guida, M. [Department of Information Engineering and Electrical Engineering, University of Salerno, Fisciano (Italy); Pulcini, G. [Istituto Motori, National Research Council-CNR, Naples (Italy)], E-mail: g.pulcini@im.cnr.it

2009-08-15

In this paper, a competing risk model is proposed to describe the reliability of the cylinder liners of a marine Diesel engine. Cylinder liners presents two dominant failure modes: wear degradation and thermal cracking. The wear process is described through a stochastic process, whereas the failure time due to the thermal cracking is described by the Weibull distribution. The use of the proposed model allows performing goodness-of-fit test and parameters estimation on the basis of both wear and failure data. Moreover, it enables reliability estimates of the state of the liners to be obtained and the hierarchy of the failure mechanisms to be determined for any given age and wear level of the liner. The model has been applied to a real data set: 33 cylinder liners of Sulzer RTA 58 engines, which equip twin ships of the Grimaldi Group. Estimates of the liner reliability and of other quantities of interest under the competing risk model are obtained, as well as the conditional failure probability and mean residual lifetime, given the survival age and the accumulated wear. Furthermore, the model has been used to estimate the probability that a liner fails due to one of the failure modes when both of these modes act.

Quadratic Assignment of Hubs in p-Hub Median Problem

DEFF Research Database (Denmark)

Gelareh, Shahin

We introduce Generalized p-Hub Median Problem (GpHMP) that seeks to locate p hub nodes and install p distinct hub facilities/operators on the hubs while discount factor resulted by consolidation of flow on the hub links depends on the facilities/operators that are installed/operating on both hub...

Comprehensive review of geosynthetic clay liner and compacted clay liner

Science.gov (United States)

Shankar, M. Uma; Muthukumar, M.

2017-11-01

Human activity inevitably produces waste materials that must be managed. Some waste can be reused. However many wastes that cannot be used beneficially must be disposed of ensuring environmental safety. One of the common methods of disposal is landfilling. The most common problems of the landfill site are environmental degradation and groundwater contamination caused by leachate produced during the decomposition process of organic material and rainfall. Liner in a landfill is an important component which prevent leachate migration and prevent groundwater contamination. Earthen liners have been widely used to contain waste materials in landfill. Liners and covers for municipal and hazardous waste containment facilities are often constructed with the use of fine-grained, low plasticity soils. Because of low permeability geosynthetic clay liners and compacted clay liners are the main materials used in waste disposal landfills. This paper summaries the important geotechnical characteristics such as hydraulic conductivity, liquid limit and free swell index of geosynthetic clay liner and compacted clay liner based on research findings. This paper also compares geosynthetic clay liner and compacted clay liner based on certain criteria such as thickness, availability of materials, vulnerability to damage etc.

Routing and Scheduling in Tramp Shipping - Integrating Bunker Optimization

DEFF Research Database (Denmark)

Vilhelmsen, Charlotte; Lusby, Richard Martin; Larsen, Jesper

A tramp ship operator typically has some contracted cargoes that must be carried and seeks to maximize proFIt by carrying optional cargoes. Hence, tramp ships operate much like taxies following available cargoes and not according to a fixed route network and itinerary as liner ships. Marine fuel....... We devise a solution method based on column generation with a dynamic programming algorithm to generate columns. The method is heuristic mainly due to a discretization of the continuous bunker purchase variables. We show that the integrated planning approach can increase profits and that the decision...

Routing and Scheduling in Tramp Shipping - Integrating Bunker Optimization

DEFF Research Database (Denmark)

Vilhelmsen, Charlotte; Lusby, Richard Martin; Larsen, Jesper

A tramp ship operator typically has some contracted cargoes that must be carried and seeks to maximize pro_t by carrying optional cargoes. Hence, tramp ships operate much like taxies following available cargoes and not according to a _xed route network and itinerary as liner ships. Marine fuel...... and bunker consumption. We devise a solution method based on column generation with a dynamic programming algorithm to generate columns. The method is heuristic mainly due to a discretization of the continuous bunker purchase variables. We show that the integrated planning approach can increase pro...

An investigation of forecast horizon and observation fit’s influence on an econometric rate forecast model in the liner shipping industry

DEFF Research Database (Denmark)

Nielsen, Peter; Jiang, Liping; Rytter, Niels Gorm Malý

2014-01-01

This paper evaluates the influence of forecast horizon and observation fit on the robustness and performance of a specific freight rate forecast model used in the liner shipping industry. In the first stage of the research, a forecast model used to predict container freight rate development...... of the forecast horizon and observation fit and their interactions on the forecast model's performance. The results underline the complicated nature of creating a suitable forecast model by balancing business needs, a desire to fit a good model and achieve high accuracy. There is strong empirical evidence from...... this study; that a robust model is preferable, that overfitting is a true danger, and that a balance must be achieved between forecast horizon and the number of observations used to fit the model. In addition, methodological guidance has also been provided on how to test, design, and choose the superior...

Optimisation of energy absorbing liner for equestrian helmets. Part II: Functionally graded foam liner

International Nuclear Information System (INIS)

Cui, L.; Forero Rueda, M.A.; Gilchrist, M.D.

2009-01-01

The energy absorbing liner of safety helmets was optimised using finite element modelling. In this present paper, a functionally graded foam (FGF) liner was modelled, while keeping the average liner density the same as in a corresponding reference single uniform density liner model. Use of a functionally graded foam liner would eliminate issues regarding delamination and crack propagation between interfaces of different density layers which could arise in liners with discrete density variations. As in our companion Part I paper [Forero Rueda MA, Cui L, Gilchrist MD. Optimisation of energy absorbing liner for equestrian helmets. Part I: Layered foam liner. Mater Des [submitted for publication

Experimental evaluation of cell liners

International Nuclear Information System (INIS)

Wierman, R.W.; Simmons, L.D.; Muhlestein, L.D.

Cell liners may be used in breeder reactor sodium pipe ways, sodium cells, and lower cavity region to provide a leak-tight cell and to protect the concrete from sodium in the unlikely event of a sodium spill. The objectives of the HEDL liner verification test program are to evaluate the integrity of liner concepts under postulated accident conditions and to develop the experimental data base which will demonstrate that liners will not fail. Two specific tests are reported; a high temperature liner feature test, and a large-scale liner sodium spill test. In both tests no failures of the liners or tendencies toward failure were detected. The discussed liner designs appeared to be conservative, and the liner strength appeared to be more than adequate

Parametric study of propeller boss cap fins for container ships

Science.gov (United States)

Lim, Sang-Seop; Kim, Tae-Won; Lee, Dong-Myung; Kang, Chung-Gil; Kim, Soo-Young

2014-06-01

The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed

Simulation of LOCA and ageing effect with containment liner mockup for analysis of liner-concrete interaction

International Nuclear Information System (INIS)

Wienand, B.; Fila, A.; Hermann, N.; Mueller, M.

2015-01-01

The investigation of the pre-stressed concrete wall behavior including the liner during LOCA conditions is important for the assessment of the structural integrity of the structure and the leak tightness of the liner. In the frame of the NUGENIA ACCEPPT project WP1 G4 'Structural interaction of liner with the concrete', a load test on a reactor containment liner mockup was carried out. The pre-stressed mockup represents a cylindrical part of the liner, embedded in the concrete wall, but without the wall curvature which is not test relevant. It correlates in material and geometrical properties to the EPR containment. The purpose of the test was to check the liners structural behavior and its integrity for Loss of Coolant Accident (LOCA) load combination considering pre-stressing forces and ageing effects due to creep and shrinkage including liner buckling. The test was carried out at the Karlsruhe Institute of Technology (KIT) in September 2013. This article presents the measurement technology, the results and the development of a calculation method for the embedded liner structure. It appears that the liner deformation results are exemplarily shown at the locations of the imperfections, where the liner buckling is anticipated. The measured liner surface strains ranged between +2 and -10 per thousand. The compressive strains are higher than the tensile strains due to the compressive membrane strains caused by pre-stressing and heating. Although the liner got plastic deformations, the liner strains are still far below the elongation at rupture, which indicates that the liner integrity is ensured. We can conclude that the liner mockup test proceeded as planned. The evaluation results show that the purpose of the liner mockup to simulate LOCA + ageing conditions and liner buckling has fully been achieved

Liner mounting assembly

Science.gov (United States)

Halila, Ely E. (Inventor)

1994-01-01

A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange.

Development of liner cutting method for stainless steel liner

International Nuclear Information System (INIS)

Takahata, Masato; Wignarajah, Sivakmaran; Kamata, Hirofumi

2005-01-01

The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in cells and fuel storage pools of nuclear facilities. The effects of basic laser cutting parameters such as cutting speed, assist gas flow etc. were first studied applying a 1 kW Nd:YAG laser to mock up concrete specimens lined with 3 mm thick stainless steel sheets. These initial studies were followed by studies on the effect of unevenness of the liner surface and on methods of confining contamination during the cutting process. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. In addition to the above results, this paper describes the design outline of a laser cutting system for cutting stainless liners at site and evaluates its merit and cost performance. (author)

Sanitary landfill liners

DEFF Research Database (Denmark)

Christiansen, Ole V.; Stentsøe, Steen; Petersen, Søren

DS/INF 466 is the revised Danish recommendation for investigations, design and construction of landfill liners.......DS/INF 466 is the revised Danish recommendation for investigations, design and construction of landfill liners....

75 FR 67970 - Notice of Inquiry; An Analysis of the European Union Repeal of the Liner Conference Block Exemption

Science.gov (United States)

2010-11-04

... FEDERAL MARITIME COMMISSION Notice of Inquiry; An Analysis of the European Union Repeal of the... information and comments concerning the effects on international liner shipping of the European Union's (``E.U.... The adoption by the European Union of Regulation 1419/2006 (``Repeal''), on September 25, 2006...

Composite liners protect ground water

Energy Technology Data Exchange (ETDEWEB)

Tatzky, R; August, H

1987-12-01

For about 10 years flexible membrane liners (FMLs) have been used as bottom liners to protect ground water in the vicinity of waste sites. But a permeation (absorption, diffusion, desorption) of chemical liquids, e.g. hydrocarbons (HC) and chlorinated hydrocarbons (CHC) will generally occur. The rates of permeation depend, first of all, on the chemical affinity, the thickness of the FML and the boundary conditions. In order to improve the barrier quality of polymeric membranes, it is necessary to study the transport processes of HC and CHC through the polymeric materials. Long-term tests with composite liners are additionally carried out. These are liners which consist of two components, flexible membrane and natural soil liner (recompacted clay, bentonite-soil mixtures). Laboratory studies show that with composite liners a perfect sealing of waste sites may be possible. Test methods for measuring permeation rates of HC and CHC through polymeric membranes and methods of testing for the development of composite liner systems are presented. (orig.)

Fracture-dissociation of ceramic liner.

Science.gov (United States)

Hwang, Sung Kwan; Oh, Jin-Rok; Her, Man Seung; Shim, Young Jun; Cho, Tae Yeun; Kwon, Sung Min

2008-08-01

The use of BIOLOX delta ceramic (CeramTec AG, Plochingen, Germany) has been increasing. This ceramic prevents cracking by restraining the phase transformation due to the insertion of nano-sized, yttria-stabilized tetragonal zirconia into the alumina matrix. This restrains the progress of cracking through the formation of platelet-like crystal or whiskers due to the addition of an oxide additive. We observed a case of BIOLOX delta ceramic liner (CeramTec AG) rim fracture 4 months postoperatively. Radiographs showed that the ceramic liner was subluxated from the acetabular cup. Scratches on the acetabular cup and femoral neck were seen, and the fracture was visible on the rim of the liner. Under electron microscope, metal particle coatings from the ceramic liner were identified. The ceramic liner, fracture fragments, and adjacent tissues were removed and replaced with a ceramic liner and femoral head of the same size and design. We believe the mechanism of the fracture-dissociation of the ceramic liner in this case is similar to a case of separation of the ceramic liner from the polyethylene shell in a sandwich-type ceramic-ceramic joint. To prevent ceramic liner fracture-dissociation, the diameter of the femoral neck needs to be decreased in a new design, while the diameter of the femoral head needs to be increased to ensure an increase in range of motion.

Capacitated Hub Routing Problem in Hub-and-Feeder Network Design: Modeling and Solution Algorithm

OpenAIRE

Gelareh , Shahin; Neamatian Monemi , Rahimeh; Semet , Frédéric

2015-01-01

International audience; In this paper, we address the Bounded Cardinality Hub Location Routing with Route Capacity wherein eachhub acts as a transshipment node for one directed route. The number of hubs lies between a minimum anda maximum and the hub-level network is a complete subgraph. The transshipment operations take place atthe hub nodes and flow transfer time from a hub-level transporter to a spoke-level vehicle influences spoketo-hub allocations. We propose a mathematical model and a b...

Study on process design of partially-balanced, hydraulically lifting vertical ship lift

Science.gov (United States)

Xin, Shen; Xiaofeng, Xu; Lu, Zhang; Bing, Zhu; Fei, Li

2017-11-01

The hub ship lift in Panjin is the first navigation structure in China for the link between the inland and open seas, which adopts a novel partially-balanced, hydraulically lifting ship lift; it can meet such requirements as fast and sharp water level change in open sea, large draft of a yacht, and launching of a ship reception chamber; its balancing weight system can effectively reduce the load of the primary lifting cylinder, and optimize the force distribution of the ship reception chamber. The paper provides an introduction to main equipment, basic principles, main features and system composition of a ship lift. The unique power system and balancing system of the completed ship lift has offered some experience for the construction of the tourism-type ship lifts with a lower lifting height.

Localized deformation of zirconium-liner tube

International Nuclear Information System (INIS)

Nagase, Fumihisa; Uchida, Masaaki

1988-03-01

Zirconium-liner tube has come to be used in BWR. Zirconium liner mitigates the localized stress produced by the pellet-cladding interaction (PCI). In this study, simulating the ridging, stresses were applied to the inner surfaces of zirconium-liner tubes and Zircaloy-2 tubes, and, to investigate the mechanism and the extent of the effect, the behavior of zirconium liner was examined. As the result of examination, stress was concentrated especially at the edge of the deformed region, where zirconium liner was highly deformed. Even after high stress was applied, the deformation of Zircaloy part was small, since almost the concentrated stress was mitigated by the deformation of zirconium liner. In addition, stress and strain distributions in the cross section of specimen were calculated with a computer code FEMAXI-III. The results also showed that zirconium liner mitigated the localized stress in Zircaloy, although the affected zone was restricted to the region near the boundary between zirconium liner and Zircaloy. (author)

Liner used in tailings ponds

International Nuclear Information System (INIS)

Dinchak, W.G.

1984-01-01

A composite liner has been developed for use in hazardous waste impoundments and in tailings ponds where uranium is involved. The liner offers a high degree of reliability against seepage, is durable, and provides a firm working surface. The advantages of the liner are discussed

Acoustic Liners for Turbine Engines

Science.gov (United States)

Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

2016-01-01

An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

How Big is Too Big for Hubs: Marginal Profitability in Hub-and-Spoke Networks

Science.gov (United States)

Ross, Leola B.; Schmidt, Stephen J.

1997-01-01

Increasing the scale of hub operations at major airports has led to concerns about congestion at excessively large hubs. In this paper, we estimate the marginal cost of adding spokes to an existing hub network. We observe entry/non-entry decisions on potential spokes from existing hubs, and estimate both a variable profit function for providing service in markets using that spoke as well as the fixed costs of providing service to the spoke. We let the fixed costs depend upon the scale of operations at the hub, and find the hub size at which spoke service costs are minimized.

Dynamic hubs show competitive and static hubs non-competitive regulation of their interaction partners.

Directory of Open Access Journals (Sweden)

Apurv Goel

Full Text Available Date hub proteins have 1 or 2 interaction interfaces but many interaction partners. This raises the question of whether all partner proteins compete for the interaction interface of the hub or if the cell carefully regulates aspects of this process? Here, we have used real-time rendering of protein interaction networks to analyse the interactions of all the 1 or 2 interface hubs of Saccharomyces cerevisiae during the cell cycle. By integrating previously determined structural and gene expression data, and visually hiding the nodes (proteins and their edges (interactions during their troughs of expression, we predict when interactions of hubs and their partners are likely to exist. This revealed that 20 out of all 36 one- or two- interface hubs in the yeast interactome fell within two main groups. The first was dynamic hubs with static partners, which can be considered as 'competitive hubs'. Their interaction partners will compete for the interaction interface of the hub and the success of any interaction will be dictated by the kinetics of interaction (abundance and affinity and subcellular localisation. The second was static hubs with dynamic partners, which we term 'non-competitive hubs'. Regulatory mechanisms are finely tuned to lessen the presence and/or effects of competition between the interaction partners of the hub. It is possible that these regulatory processes may also be used by the cell for the regulation of other, non-cell cycle processes.

Plasma-driven liners

International Nuclear Information System (INIS)

Kilic, H.; Linhart, J.G.; Bortolotti, A.; Nardi, V.

1992-01-01

The deposition of thermal energy by laser or ion beams in an ablator is capable of producing a very large acceleration of the adjacent pusher - for power densities of 100 Terrawatts/cm 2 , ablator pressure in the range of 10 Mbar is attainable. In the case of a plasma drive such driving pressures and accelerations are not directly possible. When a snowplough (SP) is used to accelerate a thin liner, the driving pressure is that of the magnetic piston pushing the SP, i.e. at most 0.1 Mbar. However, the initial radius r 0 of the liner can be a few centimeters, instead of 1 (mm) as in the case in direct pellet implosions. In order to compete with the performance of the beam-driven liners, the plasma drive must demonstrate that a) thin liner retains a high density during the implosion (lasting a fraction of a μsec); b) radial compression ratio r 0 /r min of the order of 100 can be attained. It is also attractive to consider the staging of two or more liners in order to get sharpening and amplifications of the pressure and/or radiation pulse. If a) and b) are verified then the final pressures produced will be comparable with those of the beam-driven implosions. (author) 5 refs., 3 figs

Wastes disposal on board a ship. Disposal of sewage and waste water; Senjo no haikibutsu shori. Osui oyobi haisui no shori ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1996-07-25

This paper describes technologies and devices suitable for disposing of sewage and waste water produced in a ship. Methods for disposing of sewage in a ship include such physico-chemical disposition methods as disinfection and sterilization, and such biological disposition methods as activated sludge sewage disposition and catalytic oxidation (biological membrane treatment). Sewage treatment devices include a storage tank type sewage treatment device often used in inner sea liners such as ferry boats, and a biological treatment device (aeration device) used as a mainstream in merchant ships, large passenger liners, and governmental ships. With the storage tank type sewage treatment device, sewage is stored in a storage tank provisionally while a ship is cruising in a discharge prohibited sea area, and discharged in a sea area allowing the discharge or when the ship enters a port. The method is simple, but limited in storage volume. An activated sludge sewage treatment device consists of a tank divided into an aeration chamber, a sedimentation chamber and a disinfection chamber, an air compressor, a chlorine dissolving apparatus, and a screen. Sewage is digested and decomposed by activated sludge, and the top clear water is disinfected by chlorine, and then discharged. 1 tab.

Joint Hub Network Development

OpenAIRE

Cruijssen, F.C.A.M.; Borm, P.E.M.; Dullaert, W.; Hamers, H.J.M.

2007-01-01

This paper introduces a framework for joint hub network development. Building a joint physical hub for transhipment of goods is expensive and therefore involves considerable risks for the cooperating companies. In a practical setting, it is unlikely that an entire network will be built at once. Rather, the partners will have a more cautious attitude and build the hub facilities one-by-one. In the proposed framework, every time a new hub is introduced, partners will have the opportunity to dec...

Hub and Axis

OpenAIRE

Hansen, Gary Alan

2010-01-01

The project is for the central building of a community center used by the communities of Blacksburg and Christiansburg. The building is a space configured as a hub that uses axes to determine entering, exiting and vertical movement. The hub configuration of the building is in concentric rings around the atrium in both space and materials. As materials were brought into the building, they enhanced the strong axial configuration and emphasized the layers surrounding the central hub space of ...

Parametrical Method for Determining Optimal Ship Carrying Capacity and Performance of Handling Equipment

Directory of Open Access Journals (Sweden)

Michalski Jan P.

2016-04-01

Full Text Available The paper presents a method of evaluating the optimal value of the cargo ships deadweight and the coupled optimal value of cargo handling capacity. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper second hand ship for a given transportation task. The deadweight and the capacity are determined on the basis of a selected economic measure of the transport effectiveness of ship – the Required Freight Rate. The mathematical model of the problem is of a deterministic character and the simplifying assumptions are justified for ships operating in the liner trade. The assumptions are so selected that solution of the problem is obtained in analytical closed form. The presented method can be useful for application in the preliminary ship design or in the simulation of pre-investment transportation task studies.

Simultaneous Optimization of Container Ship Sailing Speed and Container Routing with Transit Time Restrictions

DEFF Research Database (Denmark)

Karsten, Christian Vad; Røpke, Stefan; Pisinger, David

We introduce a decision support tool for liner shipping companies to optimally determine the sailing speed and needed fleet for a global network. As a novelty we incorporate cargo routing decisions with tight transit time restrictions on each container such that we get a realistic picture...

Design of steel-liners and their anchorage with regard to non-linear behaviour of liner-material and anchorage

International Nuclear Information System (INIS)

Oberpichler, R.

1979-01-01

The thin steel liner attached by studs or rib-type anchors to the interior wall of a Prestressed Concrete Reactor Pressure Vessel (PCRV) or a Concrete Containment Vessel (PCCV) has to provide the leak-tightness of the vessel. The liner also may serve as internal shuttering for placing concrete as well as a support for the cooling system or thermal isolation. Mainly strained by self-limited loads imposed on the liner by deformations of the vessel-wall or by heatup inside the vessel the liner predominantly will function in a compressive biaxially strained state like a membrane. The vessel-wall is assumed to be a rigid boundary without reactions caused by the liner-anchor-restraints. Furthermore it is assumed that the liner supported in a close-spaced pattern to the concrete with respect to self-limited loads and all effects of non-linear behaviour of liner-material and non-linear anchor-characteristics will not fail by instability, especially not by an effect of snapthrough. Only one essential mode of failure, the shear connector failure is assumed to be basis for all liner investigations. Design of the liner and its anchorage therefore is based on the analysis of large deformations with regard to elastic-plastic behaviour of liner-material and non-linear anchor characteristics. By this method both economical and safe sizing and spacing of the anchors can be calculated. (orig.)

Europe's Southeastern Gateway: Responding to Rapidly Changing Patterns of World Shipping. The University's Role

Directory of Open Access Journals (Sweden)

Roger E. HAMLIN

2012-12-01

Full Text Available World trade and transportation are changing dramatically. Energy prices and transport sustainability concerns are reinvigorating ocean freighter shipping. An ever-increasing portion of trade is in containers, and container ships are getting larger quickly. Many ports, nations and continents are not keeping up with ship size increases putting them at a trade disadvantage. Major canals and seaways must also upgrade or be rendered obsolete, causing a change in the pattern of world trade. Ports have to do more than expand vessel size limits. Port regions must also invest in infrastructure that improves multi-modal access to the port and augments hand-off of containers to smaller seaway ships, trains and trucks. With heightened security and evolving emphasis on flexible and efficient logistics, ports must become high-tech logistics hubs with improved real-time data about port throughput. Constanţa, Romania provides an example of an attempt to respond to this rapid change. Near the Danube Delta, on the Black Sea, Constanţa offers a potential southeastern gateway to Europe for the Black Sea, the Eastern Mediterranean and beyond. Ships from Asia, entering via the Suez Canal can easily access Constanţa, and thus save more than ten days of shipping time for destinations in southeastern Europe compared to shipping through Rotterdam or Hamburg. But Constanţa needs to make all the improvements mentioned above. Universities have several roles in this endeavor, including identifying and forecasting trends, providing the technical knowledge to develop high-tech logistics hubs, pursing publicprivate partnerships for infrastructure development and offering training.

Aircraft Propeller Hub Repair

Energy Technology Data Exchange (ETDEWEB)

Muth, Thomas R [ORNL; Peter, William H [ORNL

2015-02-13

The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

Gas and LNG trading hubs, hub indexation and destination flexibility in East Asia

International Nuclear Information System (INIS)

Shi, Xunpeng; Padinjare Variam, Hari Malamakkavu

2016-01-01

In the East Asian gas markets, issues like gas trading hubs, hub indexed pricing, and destination flexibility are being debated. This paper examines the impact of a change in East Asia's pricing benchmark and contract flexibility on the regional and global gas markets. The paper uses the Nexant World Gas Model, a linear program with global cost minimization as the objective. To our knowledge, this study on hub competition, price benchmark change and contract flexibility improvement in East Asia will be the first in the literature and have real policy relevance. The results show that both price benchmark change and contract flexibility improvements will create an overall benefit for the world and East Asia importers, but the impacts are different among exporters and importers. However, there is no evidence of competition among different benchmark hubs and no evidence that destination restrictions cause the “Asia Premium”. It implies that removal of destination clauses has higher priority than the change to hub indexation for Japan, Korea and Chinese Taipei, but both should be treated equally in China. The study also suggests that East Asian importers should cooperate among themselves and with exporters to facilitate the hub creation and contract changes in East Asia. - Highlights: •Gas trading hubs in Japan and China are not mutually exclusive. •Both price benchmark changes and contract flexibility improvements are beneficial. •The “Asian Premium” is not caused by destination restriction. •Destination flexibility is much more important than hub indexation in East Asia except China. •Hub indexation is as important as destination flexibility in China due to pipeline imports.

The profit maximizing liner shipping problem with flexible frequencies: logistical and environmental considerations

DEFF Research Database (Denmark)

Giovannini, Massimo; Psaraftis, Harilaos N.

2018-01-01

for the ship operator and as a result they typically minimize costs. This treatment does not capture a fundamental characteristic of shipping market behavior, that ships tend to speed up in periods of high freight rates and slow down in depressed market conditions. This paper develops a simple model...... for a fixed route scenario which, among other things, incorporates the influence of freight rates, along with that of fuel prices and cargo inventory costs into the overall decision process. The objective to be maximized is the line’s average daily profit. Departing from convention, the model is also able...... to consider flexible service frequencies, to be selected from a broader set than the standard assumption of one call per week. It is shown that this may lead to better solutions and that the cost of forcing a fixed frequency can be significant. Such cost is attributed either to additional fuel cost...

Stabilized imploding liner fusion systems

International Nuclear Information System (INIS)

Book, D.L.; Cooper, A.L.; Ford, R.; Gerber, K.A.; Hammer, D.A.; Jenkins, D.J.; Robson, A.E.; Turchi, P.J.

1977-01-01

A new concept in imploding liner plasma compression is described in which a liquid metal liner is imploded by pistons driven by high-pressure gas, and stability of the inner surface against Rayleigh-Taylor modes is achieved by rotation. The principle has been demonstrated by using a water liner to compress air. This 'captive liner' offers the possibility of stable, reversible implosion-expansion cycles in which the plasma energy is recovered into the driving system, leading to reactor cycles with low Q and, hence, small size. A new method of setting up closed-field confinement geometries inside a liner using a rotating electron beam is described. Plasma currents induced by the beam provide initial plasma heating and generate the containment geometry. Persistence of plasma currents 100 times longer than the beam duration has been observed. Development of these methods could lead to a very compact thermonuclear reactor operating in the manner of a reciprocating engine. (author)

The Logistic of Empty Containers′ Return in the Liner-Shipping Network

Directory of Open Access Journals (Sweden)

Belayachi Naima

2017-09-01

Full Text Available The Maritime Transport is a favoured tool regarding the universal exchanges because it has gone through several evolutions. Indeed, the containerization is considered as one of the most remarkable improvements in the shipping. The containers are rented by shipping companies. However, these companies meet an empty container availability problem at some ports of Maritime Transport Network (MTN to satisfy the demands of clients. The objective of this work is to solve the problem of the imbalance of the distribution of containers and look for empty containers at less cost to meet the demands of clients. As a result, the authors propose an application to represent the MTN, and provide a balanced distribution of containers. The work presented in this article is based on a heuristic method by neighbourhood. It allows the process of the clients' demands and transfers of full containers as well as the research of empty containers by optimizing the cost of theirs return.

Characterization of EPICOR II Prefilter Liner 3

International Nuclear Information System (INIS)

Wynhoff, N.L.; Pasupathi, V.

1983-04-01

As part of the overall TMI-2 Information and Examination Program, EPICOR II Prefilter Liner 3 was examined to provide information to aid in the development of technology for safely processing highly loaded ion-exchange media. The characterization program included sampling and analyses of the liner contents, including ion-exchange media, liquids and gases, as well as examinations of the liner interior and exterior. This report details the handling of the liner, sampling and analysis of the contents, and the examinations of the liner

Characterization of EPICOR II Prefilter Liner 16

International Nuclear Information System (INIS)

Yesso, J.D.; Pasupathi, V.; Lowry, L.

1982-08-01

As part of the overall TMI-2 Information and Examination Program, EPICOR II Prefilter Liner 16 was examined to provide information to aid in the development of technology for safely processing highly loaded ion-exchange media. The characterization program included sampling and analyses of the liner contents, including ion-exchange media, liquids and gases, as well as examinations of the liner interior and exterior. This report details the handling of the liner, sampling and analysis of the contents, and the examinations of the liner

Virtual Campus Hub technology

DEFF Research Database (Denmark)

Vercoulen, Frank; Badger, Merete; Monaco, Lucio

This deliverable briefly describes which technological components have been delivered for the Virtual Campus Hub and how they can be used. A detailed discussion of the technical details of the components, how they were realized and how they fit the VCH concept can be found in deliverables D5.......4. Virtual Campus Hub Technology Evaluation Report and D6.7 The Virtual Campus Hub Concept....

Accelerating Thick Aluminum Liners Using Pulsed Power

International Nuclear Information System (INIS)

Kyrala, G.A.; Hammerburg, J.E.; Bowers, D.; Stokes, J.; Morgan, D.V.; Anderson, W.E.; Cochrane, J.C.

1999-01-01

The authors have investigated the acceleration of very thick cylindrical aluminum liners using the Pegasus II capacitory bank. These accelerated solid liners will be used to impact other objects at velocities below 1.5 km/sec, allowing one to generate and sustain shocks of a few 100 kilobar for a few microseconds. A cylindrical shell of 1100 series aluminum with an initial inner radius of 23.61 mm, an initial thickness of 3.0 mm, and a height of 20 mm, was accelerated using a current pulse of 7.15 MA peak current and a 7.4 microsecond quarter cycle time. The aluminum shell was imploded within confining copper glide planes with decreasing separation with an inward slope of 8 degrees. At impact with a cylindrical target of diameter 3-cm, the liner was moving at 1.4 km/sec and its thickness increased to 4.5 mm. Radial X-ray radiograms of the liner showed both the liner and the glide plane interface. The curvature of the inner surface of the liner was measured before impact with the 15-mm radius target. The radiograms also showed that the copper glide planes distorted as the liner radius decreased and that some axial stress is induced in the liner. The axial stresses did not affect the inner curvature significantly. Post-shot calculations of the liner behavior indicated that the thickness of the glide plane played a significant role in the distortion of the interface between the liner and the glide plane

The AGN nature of LINER nuclear sources

Science.gov (United States)

Márquez, Isabel; Masegosa, Josefa; González-Martin, Omaira; Hernández-Garcia, Lorena; Pović, Mirjana; Netzer, Hagai; Cazzoli, Sara; del Olmo, Ascensión

2017-11-01

Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2-10 keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN towards lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L_X(2-10 keV) > 10^{41} erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison with both

The AGN Nature of LINER Nuclear Sources

Energy Technology Data Exchange (ETDEWEB)

Márquez, Isabel; Masegosa, Josefa [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); González-Martin, Omaira [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia (Mexico); Hernández-Garcia, Lorena [Istituto di Astrofisica e Planetologia Spaziali, Rome (Italy); Pović, Mirjana [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); Ethiopian Space Science and Technology Institute and Entoto Observatory and Research Center, Addis Ababa (Ethiopia); Netzer, Hagai [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy and the Wise Observatory, Tel-Aviv University, Tel Aviv (Israel); Cazzoli, Sara; Olmo, Ascensión del, E-mail: isabel@iaa.es [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain)

2017-11-16

Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2–10keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN toward lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L{sub X}(2–10 keV) > 10{sup 41} erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison

The AGN Nature of LINER Nuclear Sources

International Nuclear Information System (INIS)

Márquez, Isabel; Masegosa, Josefa; González-Martin, Omaira; Hernández-Garcia, Lorena; Pović, Mirjana; Netzer, Hagai; Cazzoli, Sara; Olmo, Ascensión del

2017-01-01

Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2–10keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN toward lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L X (2–10 keV) > 10 41 erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison with

Study of imploding liner-electrode wall interaction

Energy Technology Data Exchange (ETDEWEB)

Chernyshev, V K; Zharinov, E I; Mokhov, V N [All-Russian Scientific Research Institute of Experimental Physics, Sarov (Russian Federation)

1997-12-31

Acceleration of solid aluminium liners and their interaction with electrodes is studied experimentally. One of the main goal of the experiments is to find the method of improving the contact between the liner and the electrode during the acceleration process. Two independent liners connected in series in one discharge circuit are used. This arrangement makes it possible to record two different liner positions simultaneously at one discharge current. As an energy source, a helical explosive magnetic generator of the length of 0.7 m and 100 mm in diameter is used. The shape of liners at various stages of acceleration is recorded by using a flash radiographic facility. The measured liner flight velocity and the compression radius are compared with the results of MHD model calculations. (J.U.). 21 figs., 7 refs.

Variable volume combustor with a conical liner support

Science.gov (United States)

Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Keener, Chrisophter Paul; Ostebee, Heath Michael

2017-06-27

The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a conical liner support supporting the liner.

Thermoplastic liners for carbon steel pipelines

Energy Technology Data Exchange (ETDEWEB)

Mehdi, Mauyed S.; AlDossary, Abdullah K. [Saudi Aramco, Dhahran (Saudi Arabia)

2009-12-19

Materials selection for pipe and fittings used to convey corrosive fluids has often been a challenge. Traditionally, exotic Corrosion Resistant Alloys (CRA) have been used in corrosive environments despite their high cost. Plastic lined carbon steel piping offers a cost effective alternative to the use of CRAs by eliminating corrosion, significantly reducing the use of toxic chemicals and the heavy metal usually present in CRAs. Thermoplastic Liners offer the combination of corrosion resistance and mechanical strength, which are unachievable with singular materials. Under pressure conditions, the liner is fully supported by the metalwork, while under vacuum conditions, the liner must be thick enough along with venting system to withstand the collapsing forces created by the negative pressure. Plastic liners have been used successfully to line and protect metallic pipelines for many years and have become an indispensable requirement of the oil and gas industry particularly with water injection and hydrocarbon services. In the case of internally corroded pipes, the use of thermoplastic liners for rehabilitation is an option to extend the lifetime of companies' assets, reduce maintenance cost and increase intervals between T and Is. For new construction, plastic liners in carbon steel pipes can compete technically and economically with pipelines of CRA materials and other corrosion inhibition systems. This paper describes various design features, installations of thermoplastic liners in comparison to other corrosion inhibition methods. (author)

Magnetized Target Fusion Driven by Plasma Liners

Science.gov (United States)

Thio, Y. C. Francis; Cassibry, Jason; Eskridge, Richard; Kirkpatrick, Ronald C.; Knapp, Charles E.; Lee, Michael; Martin, Adam; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

For practical applications of magnetized target fusion, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Quasi-spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a quasi-spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). Theoretical analysis and computer modeling of the concept are presented. It is shown that, with the appropriate choice of the flow parameters in the liner and the target, the impact between the liner and the target plasma can be made to be shockless in the liner or to generate at most a very weak shock in the liner. Additional information is contained in the original extended abstract.

Polybore : an innovative casing liner and patch technology

Energy Technology Data Exchange (ETDEWEB)

Hayward, C. [Trican Well Service Ltd., Calgary, AB (Canada)

2003-07-01

This PowerPoint presentation provided several images on how to install a polybore tight fitting wellbore liner developed by Trican Well Service. The high density polyethylene liner is spooled and rolled into a reducer well where weights are maintained until the liner is in place. The liner offers corrosion protection, corrosion control, chemical resistance, and wear resistance. The liner helps to optimize water injection, well disposal, as well as carbon dioxide injection. It can be placed at depths up to 2,000 m and is well suited to repair pin hole leaks or plug off existing perforations that were previously cemented. The liner can be used to repair and control wellbore corrosion at specific intervals. This presentation provides a brief history of the development of the wellbore liner along with some installation case studies. The thermal velocity liner developed by Trican insulates fluids from heat loss. It prevents liquid dropout and paraffin formation in gas wells. The liner can be used as a replacement for tubing or a loose fit liner. Erosion rates were illustrated. The system, however, is limited because the wellbore casing must be round and scraped and it cannot be used in highly deviated wells. The economic benefits of injection and disposal well applications include power savings, quick payback, corrosion resistance, and lower repair costs. The liners are more cost effective than conventional steel patch. 1 tab., 14 figs.

Can the liner be landed on the well bottom?; Posso apoiar o liner no fundo do poco?

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Carlos Fernando Humbert [PETROBRAS, Rio de Janeiro, RJ (Brazil). Departamento de Perfuracao. Div. de Suporte Tecnico

1994-07-01

During the 7 in.liner run-in operation in well 1-BSS-65 with the shoe depth at 2400 m, the setting string broke and, as a result, the whole array fell from 2800 m high. Through a fishing operation, the liner (setting tool) was recovered and later a casing string sticking was detected. Full fluid circulation was obtained and the possibility was considered of cementing the liner in that position. At this point three questions were asked to assess the feasibility of such a cementing operation: were there significant damages inflicted on the liner string as a result of the fall?; if no damages resulted from the fall, would liner bucking prevent the running in of completion tools?; would the casing withstand the strains caused by buckling? This paper addresses the two latter questions through the theory of helical bucking of the tubing confined within a cylinder. Equations are introduced to calculate the helical pitch and the axial strain due to bending. A user-friendly computer program was developed to apply this theory to instances such as the above-mentioned one or to eliminate the use of hangers with short liners. The results of the analysis carried out on this particular well are presented and an assessment of the main parameters bearing on the issue is undertaken. These parameters are: well diameter and liner length. (author)

Natural Gas Market Hubs

Data.gov (United States)

Department of Homeland Security — A hub is a physical transfer point for natural gas where several pipelines are connected. A market center is a hub where the operator offers services that facilitate...

Dynamic stabilization of imploding liquid metal liner

International Nuclear Information System (INIS)

Itoh, Yasuyuki; Fujiie, Yoichi

1979-01-01

The rotational stabilization has been proposed against the Rayleigh-Taylor instability of the imploding liquid metal liner. In this paper, the discussion is made on the possibility of the dynamic stabilization by applying the oscillating azimuthal magnetic field in addition to the axial field. In contrast to the rotational stabilization, the required (field) energy for this stabilization is also used for the liner driving or the plasma confinement. In the analysis, the liner subjected to the acceleration is assumed to be infinitely long, at rest and have the situation at the start of the implosion or turnaround. At turnaround, the existence of the plasma is taken into account. The perturbed motion of the liner is discussed with a linear stability analysis. Results are as follows: (1) The dynamic stabilization at the start of the implosion is possible if the distance from the conducting wall to the liner outer surface is comparable with or less than the liner thickness. (2) At turnaround, the stability is improved with decreasing the ratio of the plasma radius to that of the liner inner surface however the kink mode (m = 1) cannot be suppressed. (author)

Permasalahan P-Hub Median Dengan Lintasan Terpendek

OpenAIRE

Pasaribu, Raja David

2013-01-01

Hub are facilities that serve as sorting, switching, and transhipment in a transportation network. P-hub median problem is a discrete case location allocation problem which all hub is fully connected. In this paper will be intoduced Mixed Integrer Linear Programming (MILP) formulation models of cost for p-hub median problem allocation for uncapacitaced single allocation p-hub median(USApHMP). In this paper also introduced Floyd-Warshall shortest path algorithm to solve p-hub median problems a...

Conceptual design of imploding liner fusion reactors

International Nuclear Information System (INIS)

Turchi, P.J.; Robson, A.E.

1976-01-01

The basic new ingredient is the concept of rotationally stabilized liquid metal liners accelerated with free pistons. The liner motion is constrained on its outer surface by the pistons, laterally by channel walls, during acceleration, and on its inner surface, where megagauss field levels are attained by the centrifugal motion of the liner material. In this way, stable, reversible motion of the liner should be possible, permitting repetitive, pulsed operation at interior pressures far greater than can be allowed in static conductor systems. Such higher operating pressures permit the use of simple plasma geometries, such as theta pinches, with greatly reduced dimensions. Furthermore, the implosion of thick, lithium-bearing liners with large radial compression ratios inherently provides the plasma with a surrounding blanket of neutron absorbing liquid metal, thereby substantially reducing the problems of induced radioactivity and first wall damage that haunt conventional fusion reactor designs. The following article discusses the basic operation of liner reactors and several important features influencing their design

HOST liner cyclic facilities: Facility description

Science.gov (United States)

Schultz, D.

1982-01-01

A quartz lamp box, a quartz lamp annular rig, and a low pressure liner cyclic can rig planned for liner cyclic tests are described. Special test instrumentation includes an IR-TV camera system for measuring liner cold side temperatures, thin film thermocouples for measuring liner hot side temperatures, and laser and high temperature strain gages for obtaining local strain measurements. A plate temperature of 2,000 F was obtained in an initial test of an apparatus with three quartz lamps. Lamp life, however, appeared to be limited for the standard commercial quartz lamps available. The design of vitiated and nonvitiated preheaters required for the quartz lamp annular rig and the cyclic can test rigs is underway.

Using the Contextual Hub Analysis Tool (CHAT) in Cytoscape to Identify Contextually Relevant Network Hubs.

Science.gov (United States)

Muetze, Tanja; Lynn, David J

2017-09-13

Highly connected nodes in biological networks are called network hubs. Hubs are topologically important to the structure of the network and have been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we provide a step-by-step protocol for using the Contextual Hub Analysis Tool (CHAT), an application within Cytoscape 3, which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene or protein expression data, and identify hub nodes that are more highly connected to contextual nodes than expected by chance. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Geosynthetic clay liners shrinkage under simulated daily thermal cycles.

Science.gov (United States)

Sarabadani, Hamid; Rayhani, Mohammad T

2014-06-01

Geosynthetic clay liners are used as part of composite liner systems in municipal solid waste landfills and other applications to restrict the escape of contaminants into the surrounding environment. This is attainable provided that the geosynthetic clay liner panels continuously cover the subsoil. Previous case histories, however, have shown that some geosynthetic clay liner panels are prone to significant shrinkage and separation when an overlying geomembrane is exposed to solar radiation. Experimental models were initiated to evaluate the potential shrinkage of different geosynthetic clay liner products placed over sand and clay subsoils, subjected to simulated daily thermal cycles (60°C for 8 hours and 22°C for 16 hours) modelling field conditions in which the liner is exposed to solar radiation. The variation of geosynthetic clay liner shrinkage was evaluated at specified times by a photogrammetry technique. The manufacturing techniques, the initial moisture content, and the aspect ratio (ratio of length to width) of the geosynthetic clay liner were found to considerably affect the shrinkage of geosynthetic clay liners. The particle size distribution of the subsoil and the associated suction at the geosynthetic clay liner-subsoil interface was also found to have significant effects on the shrinkage of the geosynthetic clay liner. © The Author(s) 2014.

Fusion power from fast imploding liners

International Nuclear Information System (INIS)

Krakowski, R.A.; Moses, R.W.; Miller, R.L.; Germwin, R.A.

1977-01-01

An approach to fusion power is described which proposes magnetically driving a thin metal shell at high velocity (approximately 10 4 m/s) onto a warm (200 to 500 eV), dense (10 24 to 10 25 m -3 ) plasma. A description of the plasma/liner interaction by several analytic and numerical models is given. On the basis of theoretical scaling predictions, the advantages, disadvantages and uncertainties associated with a high-efficiency (recirculating power fraction less than or equal to 0.2) Fast-Liner Reactor (FLR) are described, quantified when possible, and summarized. The FLR approach is characterized by (1) a thin cylindrical nonrotating liner that would be magnetically accelerated by axial currents driven through the liner (no external coils or magnets), (2) axial and radial energy confinement would be provided by an azimuthal magnetic field associated either with axial currents driven through a hard core or through the plasma, (3) the plasma particle pressure would be supported directly by the liner surface and material end plugs, and (4) the liner and a portion of associated support structure would be destroyed at each implosion. A preliminary assessment of the technological implications of blast confinement, materials destruction and loss, energy transfer and storage requirements, and possible modes of FLR operation is presented

Contextual Hub Analysis Tool (CHAT): A Cytoscape app for identifying contextually relevant hubs in biological networks.

Science.gov (United States)

Muetze, Tanja; Goenawan, Ivan H; Wiencko, Heather L; Bernal-Llinares, Manuel; Bryan, Kenneth; Lynn, David J

2016-01-01

Highly connected nodes (hubs) in biological networks are topologically important to the structure of the network and have also been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we report a Cytoscape app, the Contextual Hub Analysis Tool (CHAT), which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene expression or mass spectrometry data, and identify hub nodes that are more highly connected to contextual nodes (e.g. genes or proteins that are differentially expressed) than expected by chance. In a case study, we use CHAT to construct a network of genes that are differentially expressed in Dengue fever, a viral infection. CHAT was used to identify and compare contextual and degree-based hubs in this network. The top 20 degree-based hubs were enriched in pathways related to the cell cycle and cancer, which is likely due to the fact that proteins involved in these processes tend to be highly connected in general. In comparison, the top 20 contextual hubs were enriched in pathways commonly observed in a viral infection including pathways related to the immune response to viral infection. This analysis shows that such contextual hubs are considerably more biologically relevant than degree-based hubs and that analyses which rely on the identification of hubs solely based on their connectivity may be biased towards nodes that are highly connected in general rather than in the specific context of interest. CHAT is available for Cytoscape 3.0+ and can be installed via the Cytoscape App Store ( http://apps.cytoscape.org/apps/chat).

The critical thickness of liners of Cu interconnects

International Nuclear Information System (INIS)

Jiang, Q; Zhang, S H; Li, J C

2004-01-01

A model for the size-dependence of activation energy is developed. With the model and Fick's second law, relationships among the liner thickness, the working life and the working temperature of a TaN liner for Cu interconnects are predicted. The predicted results of the TaN liner are in good agreement with the experimental results. Moreover, the critical thicknesses of liners of some elements are calculated

Compression of toroidal plasma by imploding plasma-liner

International Nuclear Information System (INIS)

Ikuta, Kazunari.

1979-07-01

A new concept of compressing a plasma in a closed magnetic configuration by a version of liner implosion flux compression technique is considered. The liner consists of a dense plasma cylinder, i.e. the plasma-liner. Maximum compression ratio of toroidal plasma is determined just by the initial density ratio of the toroidal plasma to the liner plasma because of the Rayleigh-Taylor instability. A start-up senario of plasma-liner is also proposed with a possible application of this concept to the creation of a burning plasma in reversed field configurations, i.e. burning plasma vortex. (author)

Optimal hub location in pipeline networks

Energy Technology Data Exchange (ETDEWEB)

Dott, D.R.; Wirasinghe, S.C.; Chakma, A. [Univ. of Calgary, Alberta (Canada)

1996-12-31

This paper discusses optimization strategies and techniques for the location of natural gas marketing hubs in the North American gas pipeline network. A hub is a facility at which inbound and outbound network links meet and freight is redirected towards their destinations. Common examples of hubs used in the gas pipeline industry include gas plants, interconnects and market centers. Characteristics of the gas pipeline industry which are relevant to the optimization of transportation costs using hubs are presented. Allocation techniques for solving location-allocation problems are discussed. An outline of the research in process by the authors in the field of optimal gas hub location concludes the paper.

Composite Liner, Multi-Megabar Shock Driver Development

International Nuclear Information System (INIS)

Cochrane, J.C. Jr.; Bartsch, R.R.; Clark, D.A.; Morgan, D.V.; Anderson, W.E.; Lee, H.; Bowers, R.L.; Atchison, W.L.; Oona, H.; Stokes, J.L.; Veeser, L.R.; Broste, W.B.

1998-01-01

The multi-megabar shock driver development is a series of experiments in support of the Los Alamos High Energy Density Physics Experimental Program. Its purpose is to develop techniques to impact a uniform, stable, composite liner upon a high Z target to produce a multi-megabar shock for EOS studies. To date, experiments have been done on the Pegasus II capacitor bank with a current of approximately12MA driving the impactor liner. The driving field is approximately200 T at the target radius of 1cm. Data will be presented on the impactor liner. The driving field is approximately200 T at the target radius of 1 cm. Data will be presented on the stability and uniformity of the impactor liner when it impacts the target cylinder. Three experiments have been done with emphasis on liner development. Shock pressures greater than a megabar have been done with emphasis on liner development. Shock pressures greater than a megabar have been produced with an Al target cylinder. A Pt target cylinder should produce shock pressures in th e 5-megabar range

Liner Stability Experiments at Pegasus: Diagnostics and Experimental Results

International Nuclear Information System (INIS)

Clark, D.A.; Morgan, D.V.; Rodriguez, G.

1998-01-01

A series of experiments to compare imploding liner performance with magneto-hydrodynamic (MHD) modeling has been performed at the Los Alamos National Laboratory Pegasus II pulse power machine. Liner instability growth originating from initial perturbations machined into the liner has been observed with high resolution. Three major diagnostics were used: radiography, Velocity Interferometer for a Surface of Any Reflector (VISAR), and fiber optic impact pins. For radiography, three flash x-ray units were mounted radially to observe liner shape at three different times during the implosion. Liner velocity was measured continuously with the VISAR for the entire distance traveled in two experiments. Optical impact pins provide a high-resolution measure of liner symmetry and shape near the end of travel. Liner performance has compared well with predictions

Development of 1D Liner Compression Code for IDL

Science.gov (United States)

Shimazu, Akihisa; Slough, John; Pancotti, Anthony

2015-11-01

A 1D liner compression code is developed to model liner implosion dynamics in the Inductively Driven Liner Experiment (IDL) where FRC plasmoid is compressed via inductively-driven metal liners. The driver circuit, magnetic field, joule heating, and liner dynamics calculations are performed at each time step in sequence to couple these effects in the code. To obtain more realistic magnetic field results for a given drive coil geometry, 2D and 3D effects are incorporated into the 1D field calculation through use of correction factor table lookup approach. Commercial low-frequency electromagnetic fields solver, ANSYS Maxwell 3D, is used to solve the magnetic field profile for static liner condition at various liner radius in order to derive correction factors for the 1D field calculation in the code. The liner dynamics results from the code is verified to be in good agreement with the results from commercial explicit dynamics solver, ANSYS Explicit Dynamics, and previous liner experiment. The developed code is used to optimize the capacitor bank and driver coil design for better energy transfer and coupling. FRC gain calculations are also performed using the liner compression data from the code for the conceptual design of the reactor sized system for fusion energy gains.

LOCATING HUBS IN TRANSPORT NETWORKS: AN ARTIFICIAL INTELLIGENCE APPROACH

OpenAIRE

Dušan Teodorović; Milica Šelmić; Ivana Vukićević

2014-01-01

Hub facilities serve as switching and transshipment points in transportation and communication networks as well as in logistic systems. Hub networks have an influence on flows on the hub-to-hub links and ensure benefit from economies of scale in inter-hub transportation. The key factors for designing a successful hub-and-spoke network are to determine the optimal number of hubs, to properly locate hubs, and to allocate the non-hubs to the hubs. This paper presents the model to determine the l...

On decisive factors of liner anchorage behaviour

International Nuclear Information System (INIS)

Bucchardt, F.; Weber, M.; Yazdi, F.

1984-01-01

Design of reinforced and prestressed containments for nuclear power plants in the FRG shall be guided by DIN 25459; this also includes the structural behaviour of the liner. While the containment safety analysis is a more global matter, the liner and especially the liner anchorage behaviour concentrates on local effects which need a more refined local area description. Due to the predominant stiffness of the concrete structure liner failure analysis are performed by decoupling the steel membrane which is then only supported by anchorage springs. A comprehensive nonlinear analytical study is carried out to examine the anchorage behaviour. (Author) [pt

LINER galaxy properties and the local environment

Science.gov (United States)

Coldwell, Georgina V.; Alonso, Sol; Duplancic, Fernanda; Mesa, Valeria

2018-05-01

We analyse the properties of a sample of 5560 low-ionization nuclear emission-line region (LINER) galaxies selected from SDSS-DR12 at low red shift, for a complete range of local density environments. The host LINER galaxies were studied and compared with a well-defined control sample of 5553 non-LINER galaxies matched in red shift, luminosity, morphology and local density. By studying the distributions of galaxy colours and the stellar age population, we find that LINERs are redder and older than the control sample over a wide range of densities. In addition, LINERs are older than the control sample, at a given galaxy colour, indicating that some external process could have accelerated the evolution of the stellar population. The analysis of the host properties shows that the control sample exhibits a strong relation between colours, ages and the local density, while more than 90 per cent of the LINERs are redder and older than the mean values, independently of the neighbourhood density. Furthermore, a detailed study in three local density ranges shows that, while control sample galaxies are redder and older as a function of stellar mass and density, LINER galaxies mismatch the known morphology-density relation of galaxies without low-ionization features. The results support the contribution of hot and old stars to the low-ionization emission although the contribution of nuclear activity is not discarded.

Joint Hub Network Development

NARCIS (Netherlands)

Cruijssen, F.C.A.M.; Borm, P.E.M.; Dullaert, W.; Hamers, H.J.M.

2007-01-01

This paper introduces a framework for joint hub network development. Building a joint physical hub for transhipment of goods is expensive and therefore involves considerable risks for the cooperating companies. In a practical setting, it is unlikely that an entire network will be built at once.

Southwest Regional Climate Hub and California Subsidiary Hub assessment of climate change vulnerability and adaptation and mitigation strategies

Science.gov (United States)

Emile Elias; Caiti Steele; Kris Havstad; Kerri Steenwerth; Jeanne Chambers; Helena Deswood; Amber Kerr; Albert Rango; Mark Schwartz; Peter Stine; Rachel Steele

2015-01-01

This report is a joint effort of the Southwest Regional Climate Hub and the California Subsidiary Hub (Sub Hub). The Southwest Regional Climate Hub covers Arizona, California, Hawai‘i and the U.S. affiliated Pacific Islands, Nevada, New Mexico, and Utah and contains vast areas of western rangeland, forests, and high-value specialty crops (Figure 1). The California Sub...

PolarHub: A Global Hub for Polar Data Discovery

Science.gov (United States)

Li, W.

2014-12-01

This paper reports the outcome of a NSF project in developing a large-scale web crawler PolarHub to discover automatically the distributed polar dataset in the format of OGC web services (OWS) in the cyberspace. PolarHub is a machine robot; its goal is to visit as many webpages as possible to find those containing information about polar OWS, extract this information and store it into the backend data repository. This is a very challenging task given huge data volume of webpages on the Web. Three unique features was introduced in PolarHub to make it distinctive from earlier crawler solutions: (1) a multi-task, multi-user, multi-thread support to the crawling tasks; (2) an extensive use of thread pool and Data Access Object (DAO) design patterns to separate persistent data storage and business logic to achieve high extendibility of the crawler tool; (3) a pattern-matching based customizable crawling algorithm to support discovery of multi-type geospatial web services; and (4) a universal and portable client-server communication mechanism combining a server-push and client pull strategies for enhanced asynchronous processing. A series of experiments were conducted to identify the impact of crawling parameters to the overall system performance. The geographical distribution pattern of all PolarHub identified services is also demonstrated. We expect this work to make a major contribution to the field of geospatial information retrieval and geospatial interoperability, to bridge the gap between data provider and data consumer, and to accelerate polar science by enhancing the accessibility and reusability of adequate polar data.

Experimental Investigation of a Helicopter Rotor Hub Wake

Science.gov (United States)

Reich, David; Elbing, Brian; Schmitz, Sven

2013-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The main objectives of the experiment were to understand the spatial- and temporal content of the unsteady wake downstream of a rotor hub up to a distance corresponding to the empennage. Primary measurements were the total hub drag and velocity measurements at three nominal downstream locations. Various flow structures were identified and linked to geometric features of the hub model. The most prominent structures were two-per-revolution (hub component: scissors) and four-per-revolution (hub component: main hub arms) vortices shed by the hub. Both the two-per-revolution and four-per-revolution structures persisted far downstream of the hub, but the rate of dissipation was greater for the four-per-rev structures. This work provides a dataset for enhanced understanding of the fundamental physics underlying rotor hub flows and serves as validation data for future CFD analyses.

Cracking investigation of Monju emergency generator C unit cylinder liner. Cylinder liner soundness confirmation by a fall cause of the materials strength of the cylinder liner and the supersonic wave speed

International Nuclear Information System (INIS)

Kobayashi, Takanori; Sakon, Miyoji; Takada, Osamu; Hatori, Masakazu; Sakamoto, Tsutomu; Sato, Toshiyuki; Kazama, Akihito; Ishizawa, Yoshihiro; Igawa, Katsuhisa; Nakae, Hideo

2012-02-01

I confirmed a leak of the effluent gas from cylinder part during a load examination after the check of the emergency generator C unit on December 28, 2010 of the facilities check average and confirmed crack in No.8 cylinder liner part. As a result, because it was not performed oil pressure management properly without attaching an oil pressure gauge when I removed cylinder liner about the cause, crack occurred by having been able to write excessive stress for the cylinder liner and reached damage. By a process of this investigation, a fall of the materials strength of some cylinder liner was confirmed, but because a lead ingredient got mixed with materials by a casting process at the time of the production of the cylinder liner, as for this, Widmannstaetten graphite occurred, and it became clear that materials strength fell. In addition, I performed inspection by the supersonic wave velocity measurement as technique to distinguish this Widmannstaetten graphite easily and confirmed that I was effective. Because this report was the knowledge that there were little inspection contents which modified soundness confirmation technique of the cylinder liner with the possibility of materials strength fall of the cylinder liner by the Widmannstaetten graphite outbreak and the mixture of lead for a report example in the field of cast iron, I gathered it in this report. (author)

Hub exchange operations in intermodal hub-and spoke networks: A performance comparison of rail-rail exchange facilities

OpenAIRE

Bontekoning, Y.M.

2006-01-01

The implementation of hub-and-spoke networks in intermodal transport is suggested as one of the potential solutions for helping to increase the intermodal market share. Traditionally, trains are shunted at hubs; this is a time-consuming process. Since the early 1990s a new type of intermodal terminal, specifically designed for fast tran-shipment at nodes in hub-and-spoke networks, has been introduced in Europe. These hub terminals could replace this time-consuming shunting. Studies on the new...

Fast liner proposal

International Nuclear Information System (INIS)

Sherwood, A.R.; Freeman, B.L.; Gerwin, R.A.; Jarboe, T.R.; Krakowski, R.A.; Malone, R.C.; Marshall, J.; Miller, R.L.; Suydam, B.

1977-08-01

This is a proposal to study, both theoretically and experimentally, the possibility of making a fusion reactor by magnetically imploding a cylindrical metallic shell on a prepared plasma. The approach is characterized by the following features: (1) the nonrotating liner would be driven by an axial current, (2) the plasma would also carry an axial current that provides an azimuthal magnetic field for thermal insulation in both the radial and longitudinal directions, (3) solid end plugs would be utilized to prevent axial loss of particles, and (4) liner speeds would be in the 10 6 cm/s range. The preliminary calculations indicate (1) that the energetics are favorable (energy inputs of about 10 MJ might produce a machine in the break-even regime), (2) that radiation and heat losses could be made tolerable, (3) that alpha-particle heating could be made very effective, and (4) that Taylor instabilities in a fast liner might be harmless because of the large viscosities at high pressures. A preliminary conceptual design of the sort of fusion reactor that might result from such an approach is discussed, as are some of the relevant reactor scaling arguments

A Conventional Liner Acoustic/Drag Interaction Benchmark Database

Science.gov (United States)

Howerton, Brian M.; Jones, Michael G.

2017-01-01

The aerodynamic drag of acoustic liners has become a significant topic in the design of such for aircraft noise applications. In order to evaluate the benefits of concepts designed to reduce liner drag, it is necessary to establish the baseline performance of liners employing the typical design features of conventional configurations. This paper details a set of experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of a number of perforate-over-honeycomb liner configurations at flow speeds of M=0.3 and 0.5. These conventional liners are investigated to determine their resistance factors using a static pressure drop approach. Comparison of the resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 Hz at source sound pressure levels of 140 and 150 dB. Educed impedance and attenuation spectra are used to determine the interaction between acoustic performance and drag.

Graphical Acoustic Liner Design and Analysis Tool

Science.gov (United States)

Howerton, Brian M. (Inventor); Jones, Michael G. (Inventor)

2016-01-01

An interactive liner design and impedance modeling tool comprises software utilized to design acoustic liners for use in constrained spaces, both regularly and irregularly shaped. A graphical user interface allows the acoustic channel geometry to be drawn in a liner volume while the surface impedance calculations are updated and displayed in real-time. A one-dimensional transmission line model may be used as the basis for the impedance calculations.

SDU6 Interior Liner Testing & Evaluation

International Nuclear Information System (INIS)

Skidmore, T. E.

2016-01-01

Two liner materials (Marseal® M-3500 and REMA Chemoline® 4CN) proposed for use as a liner inside the Saltstone Disposal Unit 6 (SDU6) were subjected to specific ASTM tests (tensile and lap-shear) after immersion in 50% and 100% simulant solutions for 1000 hours at the Savannah River Ecology Laboratory. Both liner materials exhibited good resistance to the simulant chemistry, at least based on the tests performed and the test duration/conditions imposed. In lap-shear tests, both materials failed in the base material rather than peeling apart, confirming good adhesion. The REMA 4CN bromobutyl elastomer showed superior bonding characteristics and absence of warping or delamination at the conditions tested. The Marseal M-3500 material (PVC/EVA blend with polyester reinforcement) exhibited deformation and debonding in some locations. The cause of the deformation and delamination observed in the Marseal M-3500 material is not fully known, but possibly attributed to thermomechanical stress at immersion temperatures, and the thermoplastic nature of the material. The immersion temperature (68 °C) is slightly greater than the maximum use temperature limit quoted for the Marseal M- 3500 liner (65 °C), though the basis for the service limit is unknown. The testing performed was limited in scope and only for these two liner materials. These tests were primarily performed to screen for severe incompatibility or short-term degradation in Saltstone bleedwater simulants at bounding solution temperatures. Additional testing is recommended to assess long-term performance and the overall service life of the liner.

Quantitative Analysis of Retrieved Glenoid Liners

Directory of Open Access Journals (Sweden)

Katelyn Childs

2016-02-01

Full Text Available Revision of orthopedic surgeries is often expensive and involves higher risk from complications. Since most total joint replacement devices use a polyethylene bearing, which serves as a weak link, the assessment of damage to the liner due to in vivo exposure is very important. The failures often are due to excessive polyethylene wear. The glenoid liners are complex and hemispherical in shape and present challenges while assessing the damage. Therefore, the study on the analysis of glenoid liners retrieved from revision surgery may lend insight into common wear patterns and improve future product designs. The purpose of this pilot study is to further develop the methods of segmenting a liner into four quadrants to quantify the damage in the liner. Different damage modes are identified and statistically analyzed. Multiple analysts were recruited to conduct the damage assessments. In this paper, four analysts evaluated nine glenoid liners, retrieved from revision surgery, two of whom had an engineering background and two of whom had a non-engineering background. Associated human factor mechanisms are reported in this paper. The wear patterns were quantified using the Hood/Gunther, Wasielewski, Brandt, and Lombardi methods. The quantitative assessments made by several observers were analyzed. A new, composite damage parameter was developed and applied to assess damage. Inter-observer reliability was assessed using a paired t-test. Data reported by four analysts showed a high standard deviation; however, only two analysts performed the tests in a significantly similar way and they had engineering backgrounds.

SDU6 Interior Liner Testing & Evaluation

Energy Technology Data Exchange (ETDEWEB)

Skidmore, T. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-10-14

Two liner materials (Marseal® M-3500 and REMA Chemoline® 4CN) proposed for use as a liner inside the Saltstone Disposal Unit 6 (SDU6) were subjected to specific ASTM tests (tensile and lap-shear) after immersion in 50% and 100% simulant solutions for 1000 hours at the Savannah River Ecology Laboratory. Both liner materials exhibited good resistance to the simulant chemistry, at least based on the tests performed and the test duration/conditions imposed. In lap-shear tests, both materials failed in the base material rather than peeling apart, confirming good adhesion. The REMA 4CN bromobutyl elastomer showed superior bonding characteristics and absence of warping or delamination at the conditions tested. The Marseal M-3500 material (PVC/EVA blend with polyester reinforcement) exhibited deformation and debonding in some locations. The cause of the deformation and delamination observed in the Marseal M-3500 material is not fully known, but possibly attributed to thermomechanical stress at immersion temperatures, and the thermoplastic nature of the material. The immersion temperature (68 °C) is slightly greater than the maximum use temperature limit quoted for the Marseal M- 3500 liner (65 °C), though the basis for the service limit is unknown. The testing performed was limited in scope and only for these two liner materials. These tests were primarily performed to screen for severe incompatibility or short-term degradation in Saltstone bleedwater simulants at bounding solution temperatures. Additional testing is recommended to assess long-term performance and the overall service life of the liner.

Composite hub/metal blade compressor rotor

Science.gov (United States)

Yao, S.

1978-01-01

A low cost compressor rotor was designed and fabricated for a small jet engine. The rotor hub and blade keepers were compression molded with graphite epoxy. Each pair of metallic blades was held in the hub by a keeper. All keepers were locked in the hub with circumferential windings. Feasibility of fabrication was demonstrated in this program.

Broadband Liner Optimization for the Source Diagnostic Test Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.

2012-01-01

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

Thermographic inspection of pipes, tanks, and containment liners

Energy Technology Data Exchange (ETDEWEB)

Renshaw, Jeremy B., E-mail: jrenshaw@epri.com; Muthu, Nathan [Electric Power Research Institute, 1300 West WT Harris Blvd., Charlotte, NC 28262 (United States); Lhota, James R.; Shepard, Steven M., E-mail: sshepard@thermalwave.com [Thermal Wave Imaging, 845 Livernois St., Ferndale, MI 48220 (United States)

2015-03-31

Nuclear power plants are required to operate at a high level of safety. Recent industry and license renewal commitments aim to further increase safety by requiring the inspection of components that have not traditionally undergone detailed inspected in the past, such as tanks and liners. NEI 09-14 requires the inspection of buried pipes and tanks while containment liner inspections are required as a part of license renewal commitments. Containment liner inspections must inspect the carbon steel liner for defects - such as corrosion - that could threaten the pressure boundary and ideally, should be able to inspect the surrounding concrete for foreign material that could be in contact with the steel liner and potentially initiate corrosion. Such an inspection requires a simultaneous evaluation of two materials with very different material properties. Rapid, yet detailed, inspection results are required due to the massive size of the tanks and containment liners to be inspected. For this reason, thermal NDE methods were evaluated to inspect tank and containment liner mockups with simulated defects. Thermographic Signal Reconstruction (TSR) was utilized to enhance the images and provide detailed information on the sizes and shapes of the observed defects. The results show that thermographic inspection is highly sensitive to the defects of interest and is capable of rapidly inspecting large areas.

21 CFR 872.3250 - Calcium hydroxide cavity liner.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

Ozone production efficiency of a ship-plume: ITCT 2K2 case study.

Science.gov (United States)

Kim, Hyun S; Kim, Yong H; Han, Kyung M; Kim, Jhoon; Song, Chul H

2016-01-01

Ozone production efficiency (OPE) of ship plume was first evaluated in this study, based on ship-plume photochemical/dynamic model simulations and the ship-plume composition data measured during the ITCT 2K2 (Intercontinental Transport and Chemical Transformation 2002) aircraft campaign. The averaged instantaneous OPEs (OPE(i)‾) estimated via the ship-plume photochemical/dynamic modeling for the ITCT 2K2 ship-plume ranged between 4.61 and 18.92, showing that the values vary with the extent of chemical evolution (or chemical stage) of the ship plume and the stability classes of the marine boundary layer (MBL). Together with OPE(i)‾, the equivalent OPEs (OPE(e)‾) for the entire ITCT 2K2 ship-plume were also estimated. The OPE(e)‾ values varied between 9.73 (for the stable MBL) and 12.73 (for the moderately stable MBL), which agreed well with the OPE(e)‾ of 12.85 estimated based on the ITCT 2K2 ship-plume observations. It was also found that both the model-simulated and observation-based OPE(e)‾ inside the ship-plume were 0.29-0.38 times smaller than the OPE(e)‾ calculated/measured outside the ITCT 2K2 ship-plume. Such low OPEs insides the ship plume were due to the high levels of NO and non-liner ship-plume photochemistry. Possible implications of this ship-plume OPE study in the global chemistry-transport modeling are also discussed. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Modular liquid-cooled helmet liner for thermal comfort

Science.gov (United States)

Williams, B. A.; Shitzer, A.

1974-01-01

A modular liquid-cooled helmet liner made of eight form-fitting neoprene patches was constructed. The liner was integrated into the sweatband of an Army SPH-4 helicopter aircrew helmet. This assembly was tested on four subjects seated in a hot (47 C), humid (40%) environment. Results indicate a marked reduction in the rate of increase of physiological body functions. Rectal temperature, weight loss, heart rate, and strain indices are all reduced to approximately 50% of uncooled levels. The cooling liner removed from 10% to 30% of total metabolic heat produced. This study also demonstrated the technical feasilibity of using a cooling liner in conjunction with a standard hard helmet. Potential applications of the cooling liner in thermally stressful environments are numerous, notably for helicopter and other aircrews.

Diagnostics for the Plasma Liner Experiment

International Nuclear Information System (INIS)

Lynn, A. G.; Merritt, E.; Gilmore, M.; Hsu, S. C.; Witherspoon, F. D.; Cassibry, J. T.

2010-01-01

The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical ''plasma liners'' via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n i ∼10 16 cm -3 , T e ≅T i ∼1 eV at the plasma gun mouth to n i >10 19 cm -3 , T e ≅T i ∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

Data Collection and Management with ENSITE HUB: ENSITE HUB Version 1.0

Science.gov (United States)

2017-08-01

ER D C/ CE RL S R- 17 -1 4 Engineer Site Identification for the Tactical Environment (ENSITE) Data Collection and Management with ENSITE...and Management with ENSITE HUB ENSITE HUB Version 1.0 Juliana M. Wilhoit, Natalie R. Myers, and George W. Calfas Construction Engineering Research...and standardized manner. With such a tool, CB planners (as well as designers, operators, and manag - ers) can rapidly assess possible current and

Experimental Investigation of a Helicopter Rotor Hub Flow

Science.gov (United States)

Reich, David

The rotor hub system is by far the largest contributor to helicopter parasite drag and a barrier to increasing helicopter forward-flight speed and range. Additionally, the hub sheds undesirable vibration- and instability-inducing unsteady flow over the empennage. The challenges associated with rotor hub flows are discussed, including bluff body drag, interactional aerodynamics, and the effect of the turbulent hub wake on the helicopter empennage. This study was conducted in three phases to quantify model-scale rotor hub flows in water tunnels at The Pennsylvania State University Applied research lab. The first phase investigated scaling and component interaction effects on a 1:17 scale rotor hub model in the 12-inch diameter water tunnel. Effects of Reynolds number, advance ratio, and hub geometry configuration on the drag and wake shed from the rotor hub were quantified using load cell measurements and particle-image velocimetry (PIV). The second phase focused on flow visualization and measurement on a rotor hub and rotor hub/pylon geometry in the 12-inch diameter water tunnel. Stereo PIV was conducted in a cross plane downstream of the hub and flow visualization was conducted using oil paint and fluorescent dye. The third phase concentrated on high accuracy load measurement and prediction up to full-scale Reynolds number on a 1:4.25 scale model in the 48-inch diameter water tunnel. Measurements include 6 degree of freedom loads on the hub and two-component laser-Doppler velocimetry in the wake. Finally, results and conclusions are discussed, followed by recommendations for future investigations.

Generation of a rotating liquid liner by tangential injection

International Nuclear Information System (INIS)

Burton, R.L.; Turchi, P.J.; Jenkins, D.J.; Lanham, R.E.; Cameron, J.; Cooper, A.L.

1979-01-01

Efficient compression of low mass-density payloads by the implosion of higher mass-density liquid cylinders or liners, as in the NRL LINUS concept for controlled thermonuclear fusion, requires rotation of the liner material to avoid Rayleigh--Taylor instabilities at the liner-payload interface. Experimentally, such implosions have been demonstrated with liners formed within rotating implosion chambers. The present work uses a scale-model experimental apparatus to investigate the possibility of creating liner rotation by tangential injection of the liquid liner material. Different modes of behavior are obtained depending on the fluid exhaust procedures. Right-circular, cylindrical free surfaces are achieved with axial exhaust of fluid at radii interior to the injection nozzles, for which the liner exhibits a combination of solid-body and free vortex flows in different regions. Measurements allow estimates of power losses to viscous shear, turbulence, etc. A simple model based on open-channel flow is then derived, which is in good agreement with experiment, and is used to extrapolate results to the scale of a possible LINUS fusion reactor

Temporary abandonment cement plug on the liner top; Tampao de abandono temporario na boca do liner

Energy Technology Data Exchange (ETDEWEB)

Hiss Filho, Paulo Henrique; Costa Junior, Pedro Americo da; Viana, Jose Luis Rodrigues [PETROBRAS, Rio de Janeiro, RJ (Brazil). Distrito de Pefuracao do Sudeste. Div. de Tecnicas de Perfuracao

1994-07-01

In many instances wells are temporary abandoned just after cementing liner to be completed later or to have the BOP removed to change rams. In these cases, an additional volume of slurry is designed in order to bring the top of cement plug over the liner top, thus saving the time required for all full plugging operation. (author)

Liquid metal liner implosion systems with blade lattice for fusion

International Nuclear Information System (INIS)

Itoh, Yasuyuki; Fujiie, Yoichi

1980-01-01

In this paper, the liquid liner implosion systems with the blade lattice is proposed for the rotational stabilization of the liner inner surface which is facing a plasma in a fusion reactor. The blades are electrically conducting and inclined to the radial direction. Its major function is either acceleration or deceleration of the liner in the azimuthal direction. This system enables us to exclude the rotary mechanism for the liner rotation. In this system, the liner is formed as an annular flow of a liquid metal (the waterfall concept). Results show that there is no significant difference of the energy cost for the stabilization compared with the earlier proposed system where a liner is rotated rigidly before implosion. Furthermore, the application of the rotating blade lattice makes it possible to reduce the rotational kinetic energy required for the stabilization at turnaround, where the lattice acts as an impeller in the initial liner rotation. There is an optimum blade angle to maximize the compressed magnetic field energy inside the liner for a given driving energy. (author)

Evaluation of Skin Friction Drag for Liner Applications in Aircraft

Science.gov (United States)

Gerhold, Carl H.; Brown, Martha C.; Jasinski, Christopher M.

2016-01-01

A parameter that is gaining significance in the evaluation of acoustic liner performance is the skin friction drag induced by air flow over the liner surface. Estimates vary widely regarding the amount of drag the liner induces relative to a smooth wall, from less than a 20% increase to nearly 100%, and parameters such as face sheet perforate hole diameter, percent open area, and sheet thickness are expected to figure prominently in the skin friction drag. Even a small increase in liner drag can impose an economic penalty, and current research is focused on developing 'low drag' liner concepts, with the goal being to approach the skin friction drag of a smooth wall. The issue of skin friction drag takes on greater significance as airframe designers investigate the feasibility of putting sound absorbing liners on the non-lifting surfaces of the wings and fuselage, for the purpose of reducing engine noise reflected and scattered toward observers on the ground. Researchers at the NASA Langley Research Center have embarked on investigations of liner skin friction drag with the aims of: developing a systematic drag measurement capability, establishing the drag of current liners, and developing liners that produce reduced drag without compromising acoustic performance. This paper discusses the experimental procedures that have been developed to calculate the drag coefficient based on the change in momentum thickness and the companion research program being carried out to measure the drag directly using a force balance. Liner samples that are evaluated include a solid wall with known roughness and conventional liners with perforated facesheets of varying hole diameter and percent open area.

CANMET Gasifier Liner Coupon Material Test Report

Energy Technology Data Exchange (ETDEWEB)

Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

2007-01-31

This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects.

Soft hub for bearingless rotors

Science.gov (United States)

Dixon, Peter G. C.

1991-01-01

Soft hub concepts which allow the direct replacement of articulated rotor systems by bearingless types without any change in controllability or need for reinforcement to the drive shaft and/or transmission/fuselage attachments of the helicopter were studied. Two concepts were analyzed and confirmed for functional and structural feasibility against a design criteria and specifications established for this effort. Both systems are gimballed about a thrust carrying universal elastomeric bearing. One concept includes a set of composite flexures for drive torque transmittal from the shaft to the rotor, and another set (which is changeable) to impart hub tilting stiffness to the rotor system as required to meet the helicopter application. The second concept uses a composite bellows flexure to drive the rotor and to augment the hub stiffness provided by the elastomeric bearing. Each concept was assessed for weight, drag, ROM cost, and number of parts and compared with the production BO-105 hub.

Diagnostics for the plasma liner experiment.

Science.gov (United States)

Lynn, A G; Merritt, E; Gilmore, M; Hsu, S C; Witherspoon, F D; Cassibry, J T

2010-10-01

The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical "plasma liners" via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n(i)∼10(16) cm(-3), T(e)≈T(i)∼1 eV at the plasma gun mouth to n(i)>10(19) cm(-3), T(e)≈T(i)∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

In-situ studies on the performance of landfill caps (compacted soil liners, geomembranes, geosynthetic clay liners, capillary barriers)

International Nuclear Information System (INIS)

Melchior, S.

1997-01-01

Since 1986 different types of landfill covers have been studied in-situ on the Georgswerder landfill in Hamburg, Germany. Water balance data are available for eight years. The performance of different carriers has been measured by collecting the leakage on areas ranging from 100 m 2 to 500 m 2 . Composite liners with geomembranes performed best, showing no leakage. An extended capillary barrier also performed well. The performance of compacted soil liners, however, decreased severely within five years due to desiccation, shrinkage and plant root penetration (liner leakage now ranging from 150 mm/a to 200 mm/a). About 50 % of the water that reaches the surface of the liner is leaking through it. The maximum leakage rates have increased from 2 x 10 -10 m 3 m -2 s -1 to 4 x 10 -8 m 3 m -2 s -1 . Two types of geosynthetic clay liners (GCL) have been tested for two years now with disappointing results. The GCL desiccated during the first dry summer of the study. High percolation rates through the GCL were measured during the following winter (45 mm resp. 63 mm in four months). Wetting of the GCL did not significantly reduce the percolation rates

The photoionization mechanism of LINERs - Stellar and nonstellar

Science.gov (United States)

Ho, Luis C.; Filippenko, Alexei V.

1993-01-01

We present high quality spectroscopic observations of a sample of 14 LINERs. Starlight removal is achieved by the subtraction of a suitable absorption-line 'template' galaxy, allowing accurate measurements of emission lines. We use these line fluxes to examine the possible excitation mechanisms of LINERs. We suggest that LINERs with weak forbidden O I 6300-A emission may be H II regions photoionized by unusually hot O-type stars. LINERs with forbidden O I/H-alpha approximately greater than 1/6 may be powered by photoionization from a nonstellar continuum. This is supported by the detection of broad H-alpha emission, a correlation between line width and critical density, and pointlike X-ray emission in several of these objects.

Evaluation of Novel Liner Concepts for Fan and Airframe Noise Reduction

Science.gov (United States)

Jones, M. G.; Howerton, B. M.

2016-01-01

This paper presents a review of four novel liner concepts: soft vanes, over-the-rotor liners, external liners, and flap side-edge liners. A number of similarities in the design and evaluation of these concepts emerged during these investigations. Since these were the first attempts to study these particular liner concepts, there was limited information to guide the design process. In all cases, the target frequencies (or frequency range) were known, but the optimum acoustic impedance and optimum liner placement were typically not known. For these cases, the maximum available surface was used and a c-impedance was targeted based on the assumption the sound field impinges on the surface at normal incidence. This choice proved fruitful for every application. An impedance prediction model was used to design variable-depth liner configurations, and a graphical design code (ILIAD) was developed to aid in this process. The ability to build increasingly complex liner configurations via additive manufacturing was key, such that multiple designs could quickly be tested in a normal incidence impedance tube. The Two-Thickness Method was used to evaluate available bulk materials, such that bulk liners could also be considered for each application. These novel liner concepts provide sufficient noise reduction to warrant further investigations.

49 CFR 193.2187 - Nonmetallic membrane liner.

Science.gov (United States)

2010-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank...

Savannah River Site Eastern Transportation Hub: A Concept For a DOE Eastern Packaging, Staging and Maintenance Center - 13143

International Nuclear Information System (INIS)

England, Jeffery L.; Adams, Karen; Maxted, Maxcine; Ruff Jr, Clarence; Albenesius, Andrew; Bowers, Mark D.; Fountain, Geoffrey; Hughes, Michael; Gordon, Sydney; O'Connor, Stephen

2013-01-01

The Department of Energy (DOE) is working to de-inventory sites and consolidate hazardous materials for processing and disposal. The DOE administers a wide range of certified shipping packages for the transport of hazardous materials to include Special Nuclear Material (SNM), radioactive materials, sealed sources and radioactive wastes. A critical element to successful and safe transportation of these materials is the availability of certified shipping packages. There are over seven thousand certified packagings (i.e., Type B/Type AF) utilized within the DOE for current missions. The synergistic effects of consolidated maintenance, refurbishment, testing, certification, and costing of these services would allow for efficient management of the packagings inventory and to support anticipated future in-commerce shipping needs. The Savannah River Site (SRS) receives and ships radioactive materials (including SNM) and waste on a regular basis for critical missions such as consolidated storage, stabilization, purification, or disposition using H-Canyon and HB-Line. The Savannah River National Laboratory (SRNL) has the technical capability and equipment for all aspects of packaging management. SRS has the only active material processing facility in the DOE complex and is one of the sites of choice for nuclear material consolidation. SRS is a logical location to perform maintenance and periodic testing of the DOE fleet of certified packagings. This initiative envisions a DOE Eastern Packaging Staging and Maintenance Center (PSMC) at the SRS and a western hub at the Nevada National Security Site (NNSS), an active DOE Regional Disposal Site. The PSMC's would be the first place DOE would go to meet their radioactive packaging needs and the primary locations projects would go to disposition excess packaging for beneficial reuse. These two hubs would provide the centralized management of a packaging fleet rather than the current approach to design, procure, maintain and dispose

Stress analysis of liners for prestressed concrete reactor pressure vessels with regard to non-linear behaviour of liner material and of anchor-characteristics

International Nuclear Information System (INIS)

Oberpichler, R.; Schnellenbach, G.

1975-01-01

The thin liner attached by anchors like a membrane to the interior wall of a prestressed concrete reactor pressure vessel (PCRV) has to provide the leak-tightness of the vessel. Furthermore the liner may serve as internal shuttering for placing of concrete as well as a support for the cooling system. The two-dimensional behaviour of the liner is investigated with regard to non-linear anchor-characteristics and non-linear material behaviour of the liner. The analysis is based on a plane stress model under the assumption of a membrane state of the liner. Calculations are performed by the dynamic relaxation method. With the aid of available non-linear stress-strain diagrams, describing the post-buckling behaviour, individual panels are considered as buckled ones. The adjacent unbuckled panels are calculated on other non-linear diagrams. Strains and stresses in the liner and additional shear loads in the anchors can be calculated with arbitrary sizing and spacing of the anchors. With respect to the parameters they are easily controlled. Since actual loads on the liner are defined by the PCRV-behaviour, an economical and safe design is possible. Finally an extreme case is calculated to assess the maximum value of the shear-forces assuming zero post-buckling capacity for the buckled panel. (Auth.)

Supervised hub-detection for brain connectivity

DEFF Research Database (Denmark)

Kasenburg, Niklas; Liptrot, Matthew George; Reislev, Nina Linde

2016-01-01

, but can smooth discriminative signals in the population, degrading predictive performance. We present a novel hub-detection optimized for supervised learning that both clusters network nodes based on population level variation in connectivity and also takes the learning problem into account. The found......A structural brain network consists of physical connections between brain regions. Brain network analysis aims to find features associated with a parameter of interest through supervised prediction models such as regression. Unsupervised preprocessing steps like clustering are often applied...... hubs are a low-dimensional representation of the network and are chosen based on predictive performance as features for a linear regression. We apply our method to the problem of finding age-related changes in structural connectivity. We compare our supervised hub-detection (SHD) to an unsupervised hub...

Pre-announcements of price increase intentions in liner shipping spot markets

DEFF Research Database (Denmark)

Chen, Gang; Rytter, Niels G M; Jiang, Liping

2017-01-01

competition perspective, which will indirectly indicate whether carriers are able to manipulate spot rates following GRI announcements. Taking the Far East–North Europe trade between 2009 and 2013 as an example, the paper first reveals the gradual increase of GRI frequency and size, which reflects carriers...... factors, in sequence of explanation power, are the total capacity of GRI carriers, the idling fleet size, the spot rate level, and the average ship-loading factor. Clearly the latter three factors are market fundamentals, which are unlikely to be influenced by an individual carrier in the short term....... In actual fact, the conclusion reached is that there is little evidence that carriers can manipulate and distort spot rates through GRIs...

Design and modeling of precision solid liner experiments on Pegasus

International Nuclear Information System (INIS)

Bowers, R.L.; Brownell, J.H.; Lee, H.; McLenithan, K.D.; Scannapieco, A.J.; Shanahan, W.R.

1998-01-01

Pulsed power driven solid liners may be used for a variety of physics experiments involving materials at high stresses. These include shock formation and propagation, material strain-rate effects, material melt, instability growth, and ejecta from shocked surfaces. We describe the design and performance of a cylindrical solid liner that can attain velocities in the several mm/μs regime, and that can be used to drive high-stress experiments. An approximate theoretical analysis of solid liner implosions is used to establish the basic parameters (mass, materials, and initial radius) of the driver. We then present one-dimensional and two-dimensional simulations of magnetically driven, liner implosions which include resistive heating and elastic endash plastic behavior. The two-dimensional models are used to study the effects of electrode glide planes on the liner close-quote s performance, to examine sources of perturbations of the liner, and to assess possible effects of instability growth during the implosion. Finally, simulations are compared with experimental data to show that the solid liner performed as predicted computationally. Experimental data indicate that the liner imploded from an initial radius of 2.4 cm to a target radius of 1.5 cm, and that it was concentric and cylindrical to better than the experimental resolution (60 μm) at the target. The results demonstrate that a precision solid liner can be produced for high-stress, pulsed power applications experiments. copyright 1998 American Institute of Physics

Development of a Multifidelity Approach to Acoustic Liner Impedance Eduction

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.

2017-01-01

The use of acoustic liners has proven to be extremely effective in reducing aircraft engine fan noise transmission/radiation. However, the introduction of advanced fan designs and shorter engine nacelles has highlighted a need for novel acoustic liner designs that provide increased fan noise reduction over a broader frequency range. To achieve aggressive noise reduction goals, advanced broadband liner designs, such as zone liners and variable impedance liners, will likely depart from conventional uniform impedance configurations. Therefore, educing the impedance of these axial- and/or spanwise-variable impedance liners will require models that account for three-dimensional effects, thereby increasing computational expense. Thus, it would seem advantageous to investigate the use of multifidelity modeling approaches to impedance eduction for these advanced designs. This paper describes an extension of the use of the CDUCT-LaRC code to acoustic liner impedance eduction. The proposed approach is applied to a hardwall insert and conventional liner using simulated data. Educed values compare well with those educed using two extensively tested and validated approaches. The results are very promising and provide justification to further pursue the complementary use of CDUCT-LaRC with the currently used finite element codes to increase the efficiency of the eduction process for configurations involving three-dimensional effects.

Capacitated Bounded Cardinality Hub Routing Problem: Model and Solution Algorithm

OpenAIRE

Gelareha, Shahin; Monemic, Rahimeh Neamatian; Semetd, Frederic

2017-01-01

In this paper, we address the Bounded Cardinality Hub Location Routing with Route Capacity wherein each hub acts as a transshipment node for one directed route. The number of hubs lies between a minimum and a maximum and the hub-level network is a complete subgraph. The transshipment operations take place at the hub nodes and flow transfer time from a hub-level transporter to a spoke-level vehicle influences spoke- to-hub allocations. We propose a mathematical model and a branch-and-cut algor...

The magnetically driven imploding liner parameter space of the ATLAS capacitor bank

CERN Document Server

Lindemuth, I R; Faehl, R J; Reinovsky, R E

2001-01-01

Summary form only given, as follows. The Atlas capacitor bank (23 MJ, 30 MA) is now operational at Los Alamos. Atlas was designed primarily to magnetically drive imploding liners for use as impactors in shock and hydrodynamic experiments. We have conducted a computational "mapping" of the high-performance imploding liner parameter space accessible to Atlas. The effect of charge voltage, transmission inductance, liner thickness, liner initial radius, and liner length has been investigated. One conclusion is that Atlas is ideally suited to be a liner driver for liner-on-plasma experiments in a magnetized target fusion (MTF) context . The parameter space of possible Atlas reconfigurations has also been investigated.

Metallographic examination of EPICOR-II liners from Three Mile Island

International Nuclear Information System (INIS)

McConnell, J.W. Jr.; Spaletta, H.W.

1985-01-01

Materials from selected EPICOR-II prefilter liners were collected and examined as part of the EPICOR and Waste Research and Disposition Program sponsored by the Department of Energy at the Idaho National Engineering Laboratory (INEL). The intent of that examination was to define the internal condition of liners and ensure that liners could be stored at INEL for ten years. This paper discusses the liner-integrity examination and presents the results of these examinations. Metallurgical examination of sections removed from the liners revealed no evidence of pitting or pitting-type corrosion. Measurements of wall thickness indicate that material was missing from the wall of PF-3 in an area where the protective coating had been removed to form a conductivity patch. If it is assumed that all thinning of the wall in that area is caused by corrosion, the liners will have a lifetime of approximately 50 years. 12 figures

A truck cask design for shipping defense high-level waste

International Nuclear Information System (INIS)

Madsen, M.M.; Zimmer, A.

1985-01-01

The Defense High-Level Waste (DHLW) cask is a Type B packaging currently under development by the U.S. Department of Energy (DOE). This truck cask has been designed to initially transport borosilicate glass waste from the Defense Waste Processing Facility (DWPF) to the Waste Isolation Pilot Plant (WIPP). Specific program activities include designing, testing, certifying, and fabricating a prototype legal-weight truck cask system. The design includes such state-of-the-art features as integral impact limiters and remote handling features. A replaceable shielding liner provides the flexibility for shipping a wide range of waste types and activity levels

The high pH chemical and radiation compatibility of various liner materials

International Nuclear Information System (INIS)

Whyatt, G.A.; Farnsworth, R.K.

1990-01-01

This paper reports on a flexible membrane liner that has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation would be different that those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

The high pH chemical and radiation compatibility of various liner materials

International Nuclear Information System (INIS)

Whyatt, G.; Farnsworth, R.

1990-01-01

A flexible membrane liner has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation should be different than those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

Advantages of floating covers with LLDPE Liners

International Nuclear Information System (INIS)

Munoz Gomez, J. M.

2014-01-01

Using floating covers in irrigation pounds and waste dam gives many advantages. It is a very interesting investment for those place with a high evaporation ratio. this is an easy system which improves several aspects in irrigation or drinkable water reservoirs, mainly it saves water and it saves clean-works (time and cost). It is also used in waste dam to deodorization. Time ago this application was developed with PVC liners and TPO liners, now the innovation is LLDPE liners which improve mechanical properties, durability and an easier installation. This paper develops the state of art of this design technology, and the back ground of our experience. (Author)

THE ROLE OF AUTOMOBILE TRANSPORT IN HUBS SERVICE

Directory of Open Access Journals (Sweden)

Kirill Iurievich Bely

2015-09-01

Full Text Available Article contains approaches to development and functioning of transport-logistic nodes – hubs – in modern conditions. There is hub classification and examples of them on different transport modes. An important component in providing reliability of hub work is automobile transport.

Contextual Hub Analysis Tool (CHAT: A Cytoscape app for identifying contextually relevant hubs in biological networks [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Tanja Muetze

2016-08-01

Full Text Available Highly connected nodes (hubs in biological networks are topologically important to the structure of the network and have also been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we report a Cytoscape app, the Contextual Hub Analysis Tool (CHAT, which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene expression or mass spectrometry data, and identify hub nodes that are more highly connected to contextual nodes (e.g. genes or proteins that are differentially expressed than expected by chance. In a case study, we use CHAT to construct a network of genes that are differentially expressed in Dengue fever, a viral infection. CHAT was used to identify and compare contextual and degree-based hubs in this network. The top 20 degree-based hubs were enriched in pathways related to the cell cycle and cancer, which is likely due to the fact that proteins involved in these processes tend to be highly connected in general. In comparison, the top 20 contextual hubs were enriched in pathways commonly observed in a viral infection including pathways related to the immune response to viral infection. This analysis shows that such contextual hubs are considerably more biologically relevant than degree-based hubs and that analyses which rely on the identification of hubs solely based on their connectivity may be biased towards nodes that are highly connected in general rather than in the specific context of interest.   Availability: CHAT is available for Cytoscape 3.0+ and can be installed via the Cytoscape App Store (http://apps.cytoscape.org/apps/chat.

Development of Europe's gas hubs: Implications for East Asia

Directory of Open Access Journals (Sweden)

Xunpeng Shi

2016-10-01

Full Text Available Gas trading hubs have been initially developed in the US in 1980s, UK in 1990s, more recently in European in the 2000s and mulled in East Asia now. Due to its freshness and diversification in nationality, governance and culture, the European hub experience can offer valuable lessons for East Asia. This paper seeks to advance understanding of gas hub development in Europe and provide lessons for East Asia. The European experience highlights that market liberalization and transition of gas pricing mechanism are necessary in creating the competitive markets that are needed for functional gas hubs. Political will and regulations further safeguard the competition environment needed for hub development. Natural factors, such as significant domestic production and culture could have a significant impact on the hub development and transition of pricing mechanism. In East Asia, the path to gas trading hubs might be more difficult than in Europe but a growing market creates an opportunity to start new terms with new contracts. Nevertheless, East Asian needs to work hard to development its indigenous gas or LNG trading hubs.

Repairing liner of the reactor; Reparacion del liner del reactor

Energy Technology Data Exchange (ETDEWEB)

Aguilar H, F [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2001-07-15

Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

Accelerated aging tests of liners for uranium mill tailings disposal

International Nuclear Information System (INIS)

Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

1981-11-01

This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

The roles of transportation and transportation hubs in the propagation of influenza and coronaviruses: a systematic review.

Science.gov (United States)

Browne, Annie; Ahmad, Sacha St-Onge; Beck, Charles R; Nguyen-Van-Tam, Jonathan S

2016-01-01

Respiratory viruses spread in humans across wide geographical areas in short periods of time, resulting in high levels of morbidity and mortality. We undertook a systematic review to assess the evidence that air, ground and sea mass transportation systems or hubs are associated with propagating influenza and coronaviruses. Healthcare databases and sources of grey literature were searched using pre-defined criteria between April and June 2014. Two reviewers screened all identified records against the protocol, undertook risk of bias assessments and extracted data using a piloted form. Results were analysed using a narrative synthesis. Forty-one studies met the eligibility criteria. Risk of bias was high in the observational studies, moderate to high in the reviews and moderate to low in the modelling studies. In-flight influenza transmission was identified substantively on five flights with up to four confirmed and six suspected secondary cases per affected flight. Five studies highlighted the role of air travel in accelerating influenza spread to new areas. Influenza outbreaks aboard cruise ships affect 2-7% of passengers. Influenza transmission events have been observed aboard ground transport vehicles. High heterogeneity between studies and the inability to exclude other sources of infection means that the risk of influenza transmission from an index case to other passengers cannot be accurately quantified. A paucity of evidence was identified describing severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus transmission events associated with transportation systems or hubs. Air transportation appears important in accelerating and amplifying influenza propagation. Transmission occurs aboard aeroplanes, at the destination and possibly at airports. Control measures to prevent influenza transmission on cruise ships are needed to reduce morbidity and mortality. There is no recent evidence of sea transport accelerating influenza

Dynamics of heterogeneous liners with prolonged plasma creation

International Nuclear Information System (INIS)

Aleksandrov, V.V.; Branitskii, A.V.; Volkov, G.S.; Grabovskii, E.V.; Zurin, M.V.; Nedoseev, S.L.; Oleinik, G.M.; Samokhin, A.A.; Smirnov, V.P.; Fedulov, M.V.; Frolov, I.N.; Sasorov, P.V.

2001-01-01

Prolonged plasma creation in heterogeneous liners, in which the liner substance is separated into two phase states (a hot plasma and a cold skeleton), is investigated both experimentally and theoretically. This situation is typical of multiwire, foam, and even gas liners in high-current high-voltage facilities. The main mechanisms governing the rate at which the plasma is created are investigated, and the simplest estimates of the creation rate are presented. It is found that, during prolonged plasma creation, the electric current flows through the entire cross section of the produced plasma shell, whose thickness is comparable with the liner radius; in other words, a current skin layer does not form. During compression, such a shell is fairly stable because of its relatively high resilience. It is shown that, under certain conditions, even a thick plasma shell can be highly compressed toward the discharge axis. A simplified numerical simulation of the compression of a plasma shell in a liner with prolonged plasma creation is employed in order to determine the conditions for achieving regimes of fairly compact and relatively stable radial compression of the shell

Virtual Campus Hub technical evaluation report

DEFF Research Database (Denmark)

Vercoulen, Frank; Badger, Merete; Monaco, Lucio

This report describes and discusses the technical achievements of the Virtual Campus Hub project and formulates a brief agenda for the future.......This report describes and discusses the technical achievements of the Virtual Campus Hub project and formulates a brief agenda for the future....

Multiple-Localization and Hub Proteins

Science.gov (United States)

Ota, Motonori; Gonja, Hideki; Koike, Ryotaro; Fukuchi, Satoshi

2016-01-01

Protein-protein interactions are fundamental for all biological phenomena, and protein-protein interaction networks provide a global view of the interactions. The hub proteins, with many interaction partners, play vital roles in the networks. We investigated the subcellular localizations of proteins in the human network, and found that the ones localized in multiple subcellular compartments, especially the nucleus/cytoplasm proteins (NCP), the cytoplasm/cell membrane proteins (CMP), and the nucleus/cytoplasm/cell membrane proteins (NCMP), tend to be hubs. Examinations of keywords suggested that among NCP, those related to post-translational modifications and transcription functions are the major contributors to the large number of interactions. These types of proteins are characterized by a multi-domain architecture and intrinsic disorder. A survey of the typical hub proteins with prominent numbers of interaction partners in the type revealed that most are either transcription factors or co-regulators involved in signaling pathways. They translocate from the cytoplasm to the nucleus, triggered by the phosphorylation and/or ubiquitination of intrinsically disordered regions. Among CMP and NCMP, the contributors to the numerous interactions are related to either kinase or ubiquitin ligase activity. Many of them reside on the cytoplasmic side of the cell membrane, and act as the upstream regulators of signaling pathways. Overall, these hub proteins function to transfer external signals to the nucleus, through the cell membrane and the cytoplasm. Our analysis suggests that multiple-localization is a crucial concept to characterize groups of hub proteins and their biological functions in cellular information processing. PMID:27285823

A Branch and Cut algorithm for the container shipping network design problem

DEFF Research Database (Denmark)

Reinhardt, Line Blander; Pisinger, David

2012-01-01

The network design problem in liner shipping is of increasing importance in a strongly competitive market where potential cost reductions can influence market share and profits significantly. In this paper the network design and fleet assignment problems are combined into a mixed integer linear...... programming model minimizing the overall cost. To better reflect the real-life situation we take into account the cost of transhipment, a heterogeneous fleet, route dependant capacities, and butterfly routes. To the best of our knowledge it is the first time an exact solution method to the problem considers...

Waste Handling Shaft concrete liner degradation conclusions and recommendations

International Nuclear Information System (INIS)

1992-10-01

The primary function of the Waste Handling Shaft (WHS) at the Waste Isolation Pilot Plant (WIPP) is to permit the transfer of radioactive waste from the surface waste handling building to the underground storage area. It also serves as an intake shaft for small volumes of air during normal storage operations and as an emergency escape route. Part of the construction was the placement of a concrete liner and steel reinforced key in 1984. During a routine shaft inspection in May 1990, some degradation of the WHS concrete liner was observed between the depths of 800 and 900 feet below the ground surface. Detailed investigations of the liner had been carried out by Sandia National Laboratories and by Westinghouse Electric Corporation Waste Isolation Division (WID) through Lankard Materials Laboratory. Observations, reports, and data support the conclusion that the concrete degradation, resulting from attack by chemically aggressive brine, is a localized phenomena. It is the opinion of the WID that the degradation is not considered an immediate or near term concern; this is supported by technical experts. WID recommendations have been made which, when implemented, will ensure an extended liner life. Based on the current assessment of available data and the proposed shaft liner monitoring program described in this report, it is reasonable to assume that the operational life of the concrete shaft liner can safely support the 25-year life of the WIPP. Analysis of data indicates that degradation of the shaft's concrete liner is attributed to chemically aggressive brine seeping through construction joints and shrinkage cracks from behind the liner in and around the 834-foot depth. Chemical and mechanical components of concrete degradation have been identified. Chemical attack is comprised of several stages of concrete alteration. The other component, mechanical degradation, results from the expansive forces of crystals forming in the concrete pore space

Construction and performance of a long-term earthen liner experiment

Science.gov (United States)

Cartwright, Keros; Krapac, Ivan G.; Bonaparte, Rudolph

1990-01-01

In land burial schemes, compacted soil barriers with low hydraulic conductivity are commonly used in cover and liner systems to control the movement of liquids and prevent groundwater contamination. An experimental liner measuring 8 x 15 x 0.9 m was constructed with design criteria and equipment to simulate construction of soil liners built at waste disposal facilities. The surface of the liner was flooded with a 29.5 cm deep pond on April 12, 1988. Infiltration of water into the liner has been monitored for two years using 4 large-ring (1.5 m OD) and 32 small-ring (0.28 m OD) infiltrometers, and a water-balance that accounts for total infiltration and evaporation. Average long-term infiltration fluxes based on two years of monitoring are 5.8 x 10-9 cm/s, 6.0 x 10-8 cm/s and 5.6 x 10-8 for the large-ring, small-ring, and water-balance data, respectively. The saturated hydraulic conductivity of the liner based on small-ring data, estimated using Darcy's Law and the Green-Ampt Approximation, is 3 x 10-8 and 4 x 10-8 cm/s, respectively. All sets of data indicate that the liner's performance exceed that which is required by the U.S. EPA.

Symmetry of nonexploding cylindrical liner converging to the axis under magnetic field effects

International Nuclear Information System (INIS)

Chernyshev, V.K.; Grinevich, B.E.; Buzin, V.N.; Pogorelov, V.P.; Shertsov, V.A.; Petrukhin, A.A.; Demidov, V.A.; Zharinov, E.I.

1990-01-01

Liner acceleration, affected by magnetic pressure, is broadly used to yield megagauss magnetic fields and plasma compression. The progress of test conduction depends much on the state of liner subjected to Taylor instability while being accelerated. There is a number of methods permitting to reduce liner shape distortions, developing during its acceleration. The most simple method consists in that the aspect ratio (the ratio of liner placing radius to its thickness) is taken less than 10. To impart sufficient velocity to the liner of large thickness its density should be small. Therefore, liner is either a gas layer or explosion products of thin metal foil which passed to a vaporous state in early stage of acceleration. Acceleration of nonexploding liners may serve as the other method of asymmetry reduction. Strength and viscosity of liner will be used as stabilizing factors with respect to the development of Taylor instability. This will allow the aspect ratio increase, that is sometimes useful. Test results on acceleration of nonexploding aluminum liners 1 mm thick have been described. Aspect ratio amounted to 30-60 and the ratio of liner acceleration distance to its thickness (parameter, being of great importance when studying the development of Taylor instability) made up 20-40. Satisfactory azimuthal symmetry of liner convergence to the center was recorded. For more detailed investigation of Taylor instability influence on the symmetry of nonexploding liner, the experiments, when the ratio of liner acceleration length to its thickness would be increased up to 90-100 simultaneously with determination of azimuthal and axial symmetry of liner, are of interest. In this paper presents the results of experiments on acceleration of copper cylindrical liner 1.37 mm thick

Optimization of Variable-Depth Liner Configurations for Increased Broadband Noise Reduction

Science.gov (United States)

Jones, M. G.; Watson, W. R.; Nark, D. M.; Schiller, N. H.; Born, J. C.

2016-01-01

This paper employs three acoustic propagation codes to explore variable-depth liner configurations for the NASA Langley Grazing Flow Impedance Tube (GFIT). The initial study demonstrates that a variable impedance can acceptably be treated as a uniform impedance if the spatial extent over which this variable impedance occurs is less than one-third of a wavelength of the incident sound. A constrained optimization study is used to design a variable-depth liner and to select an optimization metric. It also provides insight regarding how much attenuation can be achieved with variable-depth liners. Another optimization study is used to design a liner with much finer chamber depth resolution for the Mach 0.0 and 0.3 test conditions. Two liners are designed based on spatial rearrangement of chambers from this liner to determine whether the order is critical. Propagation code predictions suggest this is not the case. Both liners are fabricated via additive manufacturing and tested in the GFIT for the Mach 0.0 condition. Predicted and measured attenuations compare favorably across the full frequency range. These results clearly suggest that the chambers can be arranged in any order, thus offering the potential for innovative liner designs to minimize depth and weight.

Modeling of Broadband Liners Applied to the Advanced Noise Control Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.

2015-01-01

The broadband component of fan noise has grown in relevance with an increase in bypass ratio and incorporation of advanced fan designs. Therefore, while the attenuation of fan tones remains a major factor in engine nacelle acoustic liner design, the simultaneous reduction of broadband fan noise levels has received increased interest. As such, a previous investigation focused on improvements to an established broadband acoustic liner optimization process using the Advanced Noise Control Fan (ANCF) rig as a demonstrator. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom liner designs were carried through design, fabrication, and testing. This paper addresses a number of areas for further research identified in the initial assessment of the ANCF study. Specifically, incident source specification and uncertainty in some aspects of the predicted liner impedances are addressed. This information is incorporated in updated predictions of the liner performance and comparisons with measurement are greatly improved. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of various liner designs. This study also provides further confidence in the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

Hub location proplems under polyhedral demand uncertainty

OpenAIRE

Meraklı, Merve

2015-01-01

Cataloged from PDF version of thesis. Includes bibliographical references (leaves 69-74). Thesis (M.S.): Bilkent University, Department of Industrial Engineering, İhsan Doğramacı Bilkent University, 2015. Hubs are points of consolidation and transshipment in many-to-many distribution systems that bene t from economies of scale. In hub location problems, the aim is to locate hub facilities such that each pairwise demand is satis ed and the total cost is minimized. The problem...

Competition and coordination in the U.S. airline hub-to-hub markets: An industry pre-merger case study

Directory of Open Access Journals (Sweden)

Prasun Bhattacharjee

2016-04-01

Full Text Available Purpose: This paper investigates the nature of conduct that existed in the U.S. airline hub-to-hub markets prior to the recent merger wave of the legacy carriers. We explore the strategic importance of network carrier hubs in form of “spheres of influence” on airline market conduct. We also simultaneously recognize the overgrowing role played by Low Cost Carriers (LCC over the years by estimating two conduct parameters - one in markets where LCCs directly compete head-to-head with legacy carriers and the other for markets which LCCs do not serve but has presence in the hub airports or adjacent airports comprising the market endpoints. Thus our supply side framework also sheds some light on the issue of perfect contestability in airline industry. Design/methodology/approach: We estimate a structural oligopoly model for differentiated products with competitive interactions using DB1B data for first quarter of 2004. Findings: Our results imply that the nature of competition is more aggressive relative to Bertrand behavior in hub-to-hub markets and that these markets are less than perfectly contestable. Originality/value: This paper adds to the empirical literature of airline competition by enabling estimation of the actual conduct parameter assuming firm price setting behavior in presence of product differentiation. Contrary to existing literature on airline competition, a structural model enables us to systematically separate out effects of demand, cost and strategic factors on observed airline prices.

Migration behavior of landfill leachate contaminants through alternative composite liners

Energy Technology Data Exchange (ETDEWEB)

Varank, Gamze, E-mail: gvarank@yildiz.edu.tr; Demir, Ahmet, E-mail: ahmetd@yildiz.edu.tr; Top, Selin, E-mail: stop@yildiz.edu.tr; Sekman, Elif, E-mail: esekman@yildiz.edu.tr; Akkaya, Ebru, E-mail: ekoca@yildiz.edu.tr; Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr; Bilgili, M. Sinan, E-mail: mbilgili@yildiz.edu.tr

2011-08-01

Four identical pilot-scale landfill reactors with different alternative composite liners were simultaneously operated for a period of about 540 days to investigate and to simulate the migration behaviors of phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and heavy metals (Pb, Cu, Zn, Cr, Cd, Ni) from landfill leachate to the groundwater. Alternative landfill liners of four reactors consist of R1: Compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R2: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R3: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + bentonite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn), and R4: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + zeolite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn). Wastes representing Istanbul municipal solid wastes were disposed in the reactors. To represent bioreactor landfills, reactors were operated by leachate recirculation. To monitor and control anaerobic degradation in the reactors, variations of conventional parameters (pH, alkalinity, chloride, conductivity, COD, TOC, TKN, ammonia and alcaly metals) were also investigated in landfill leachate samples. The results of this study showed that about 35-50% of migration of organic contaminants (phenolic compounds) and 55-100% of migration of inorganic contaminants (heavy metals) to the model groundwater could be effectively reduced with the use of bentonite and zeolite materials in landfill liner systems. Although leachate contaminants can reach to the groundwater in trace concentrations, findings of this study concluded that the release of these compounds from landfill leachate to the groundwater may potentially be of an important environmental concern based on the experimental findings. - Research highlights: {yields} Migration of

Numerical study of hub taper angle on podded propeller performance

International Nuclear Information System (INIS)

Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.

2005-01-01

Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

Repairing liner of the reactor; Reparacion del liner del reactor

Energy Technology Data Exchange (ETDEWEB)

Aguilar H, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2001-07-15

Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

USSR imploding liner program

International Nuclear Information System (INIS)

Shearer, J.W.

1975-01-01

A summary is given of the history and rationale of the USSR program to implode metallic liners for the fusion program. The explosive driven, magnetic drive, and compressed gas driven research is reviewed. (MOW)

Developmental Changes in Brain Network Hub Connectivity in Late Adolescence.

Science.gov (United States)

Baker, Simon T E; Lubman, Dan I; Yücel, Murat; Allen, Nicholas B; Whittle, Sarah; Fulcher, Ben D; Zalesky, Andrew; Fornito, Alex

2015-06-17

The human brain undergoes substantial development throughout adolescence and into early adulthood. This maturational process is thought to include the refinement of connectivity between putative connectivity hub regions of the brain, which collectively form a dense core that enhances the functional integration of anatomically distributed, and functionally specialized, neural systems. Here, we used longitudinal diffusion magnetic resonance imaging to characterize changes in connectivity between 80 cortical and subcortical anatomical regions over a 2 year period in 31 adolescents between the ages of 15 and 19 years. Connectome-wide analysis indicated that only a small subset of connections showed evidence of statistically significant developmental change over the study period, with 8% and 6% of connections demonstrating decreased and increased structural connectivity, respectively. Nonetheless, these connections linked 93% and 90% of the 80 regions, respectively, pointing to a selective, yet anatomically distributed pattern of developmental changes that involves most of the brain. Hub regions showed a distinct tendency to be highly connected to each other, indicating robust "rich-club" organization. Moreover, connectivity between hubs was disproportionately influenced by development, such that connectivity between subcortical hubs decreased over time, whereas frontal-subcortical and frontal-parietal hub-hub connectivity increased over time. These findings suggest that late adolescence is characterized by selective, yet significant remodeling of hub-hub connectivity, with the topological organization of hubs shifting emphasis from subcortical hubs in favor of an increasingly prominent role for frontal hub regions. Copyright © 2015 the authors 0270-6474/15/359078-10$15.00/0.

One-and-Two-Dimensional Simulations of Liner Performance at Atlas Parameters

International Nuclear Information System (INIS)

Keinigs, R.K.; Atchison, W.L.; Faehl, R.J.; Mclenithan, K.D.; Trainor, R.J.

1998-01-01

The authors report results of one-and-two-dimensional MHD simulations of an imploding heavy liner in Z-pinch geometry. The driving current has a pulse shape and peak current characteristic of the Atlas pulsed-power facility being constructed at Los Alamos National Laboratory. One-dimensional simulations of heavy composite liners driven by 30 MA currents can achieve velocities on the order of 14 km/sec. Used to impact a tungsten target, the liner produces shock pressures of ∼ fourteen megabars. The first 2-D simulations of imploding liners driven at Atlas current parameters are also described. These simulations have focused on the interaction of the liner with the glide planes, and the effect of realistic surface perturbations on the dynamics of the pinch. It is found that the former interaction does not seriously affect the inner liner surface. Results from the second problem indicate that a surface perturbation having amplitude as small as 0.2 microm can have a significant effect on the implosion dynamics

Manufacturing hollow obturator with resilient denture liner on post hemimaxillectomy

Directory of Open Access Journals (Sweden)

Michael Josef Kridanto Kamadjaja

2006-03-01

Full Text Available A resilient denture liner is placed in the part of the hollow obturator base that contacts to post hemimaxillectomy mucosa. Replacing the resilient denture liner can makes the hollow obturator has an intimate contact with the mucosa, so it can prevents the mouth liquid enter to the cavum nasi and sinus, also eliminates painful because of using the hollow obturator. Resilient denture liner is a soft and resilient material that applied to the fitting surface of a denture in order to allow a more distribution of load. A case was reported about using the hollow obturator with resilient denture liner on post hemimaxillectomy to overcome these problems.

Metallurgical examination of, and resin transfer from, Three Mile Island prefilter liners

Energy Technology Data Exchange (ETDEWEB)

McConnell, Jr, J W; Spaletta, H W

1984-08-01

Metallurgical examinations were performed on two EPICOR-II prefilter liners at the Idaho National Engineering Laboratory (INEL) to determine conditions of the liners and identify the minimum expected lifetime of those and other liners stored at INEL. The research work was accomplished by EG and G Idaho, Inc. for the EPICOR-II Research and Disposition Program, which is funded by the US Department of Energy. The EPICOR-II prefilter liners were used to filter radionuclides from contaminated water during cleanup of Three Mile Island Unit 2 (TMI-2). The liners were constructed of carbon steel with a phenolic protective coating and contained organic and inorganic ion-exchange filtration media. Program plans call for interim storage of EPICOR-II prefilters at INEL for up to ten years, before final disposal in high integrity containers at the Hanford, Washington commercial disposal site. This report describes the (a) resin transfer process used to empty liners for examination, (b) removal of metallographic sections from those liners, (c) specimen preparation, and (d) findings from metallographic examination of those specimens. A minimum lifetime for the liners is determined and recommendations are given for storage of wastes from future TMI-2 activities.

Metallurgical examination of, and resin transfer from, Three Mile Island prefilter liners

International Nuclear Information System (INIS)

McConnell, J.W. Jr.; Spaletta, H.W.

1984-08-01

Metallurgical examinations were performed on two EPICOR-II prefilter liners at the Idaho National Engineering Laboratory (INEL) to determine conditions of the liners and identify the minimum expected lifetime of those and other liners stored at INEL. The research work was accomplished by EG and G Idaho, Inc. for the EPICOR-II Research and Disposition Program, which is funded by the US Department of Energy. The EPICOR-II prefilter liners were used to filter radionuclides from contaminated water during cleanup of Three Mile Island Unit 2 (TMI-2). The liners were constructed of carbon steel with a phenolic protective coating and contained organic and inorganic ion-exchange filtration media. Program plans call for interim storage of EPICOR-II prefilters at INEL for up to ten years, before final disposal in high integrity containers at the Hanford, Washington commercial disposal site. This report describes the (a) resin transfer process used to empty liners for examination, (b) removal of metallographic sections from those liners, (c) specimen preparation, and (d) findings from metallographic examination of those specimens. A minimum lifetime for the liners is determined and recommendations are given for storage of wastes from future TMI-2 activities

Savannah River Site Eastern Transportation Hub: A Concept For a DOE Eastern Packaging, Staging and Maintenance Center - 13143

Energy Technology Data Exchange (ETDEWEB)

England, Jeffery L. [Savannah River National Laboratory, Aiken, South Carolina (United States); Adams, Karen; Maxted, Maxcine; Ruff Jr, Clarence [U.S. Department of Energy, Savannah River Site, Aiken, SC (United States); Albenesius, Andrew; Bowers, Mark D.; Fountain, Geoffrey; Hughes, Michael [Savannah River Nuclear Solutions, Aiken, SC (United States); Gordon, Sydney [National Security Technologies, LLC, Las Vegas, NV (United States); O' Connor, Stephen [U.S. Department of Energy, HQ DOE, EM-33, Germantown MD (United States)

2013-07-01

The Department of Energy (DOE) is working to de-inventory sites and consolidate hazardous materials for processing and disposal. The DOE administers a wide range of certified shipping packages for the transport of hazardous materials to include Special Nuclear Material (SNM), radioactive materials, sealed sources and radioactive wastes. A critical element to successful and safe transportation of these materials is the availability of certified shipping packages. There are over seven thousand certified packagings (i.e., Type B/Type AF) utilized within the DOE for current missions. The synergistic effects of consolidated maintenance, refurbishment, testing, certification, and costing of these services would allow for efficient management of the packagings inventory and to support anticipated future in-commerce shipping needs. The Savannah River Site (SRS) receives and ships radioactive materials (including SNM) and waste on a regular basis for critical missions such as consolidated storage, stabilization, purification, or disposition using H-Canyon and HB-Line. The Savannah River National Laboratory (SRNL) has the technical capability and equipment for all aspects of packaging management. SRS has the only active material processing facility in the DOE complex and is one of the sites of choice for nuclear material consolidation. SRS is a logical location to perform maintenance and periodic testing of the DOE fleet of certified packagings. This initiative envisions a DOE Eastern Packaging Staging and Maintenance Center (PSMC) at the SRS and a western hub at the Nevada National Security Site (NNSS), an active DOE Regional Disposal Site. The PSMC's would be the first place DOE would go to meet their radioactive packaging needs and the primary locations projects would go to disposition excess packaging for beneficial reuse. These two hubs would provide the centralized management of a packaging fleet rather than the current approach to design, procure, maintain and

Composite-Material Tanks with Chemically Resistant Liners

Science.gov (United States)

DeLay, Thomas K.

2004-01-01

Lightweight composite-material tanks with chemically resistant liners have been developed for storage of chemically reactive and/or unstable fluids . especially hydrogen peroxide. These tanks are similar, in some respects, to the ones described in gLightweight Composite-Material Tanks for Cryogenic Liquids h (MFS-31379), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 58; however, the present tanks are fabricated by a different procedure and they do not incorporate insulation that would be needed to prevent boil-off of cryogenic fluids. The manufacture of a tank of this type begins with the fabrication of a reusable multisegmented aluminum mandrel in the shape and size of the desired interior volume. One or more segments of the mandrel can be aluminum bosses that will be incorporated into the tank as end fittings. The mandrel is coated with a mold-release material. The mandrel is then heated to a temperature of about 400 F (approximately equal to 200 C) and coated with a thermoplastic liner material to the desired thickness [typically approxiamtely equal to 15 mils (approximately equal to 0.38 mm)] by thermal spraying. In the thermal-spraying process, the liner material in powder form is sprayed and heated to the melting temperature by a propane torch and the molten particles land on the mandrel. The sprayed liner and mandrel are allowed to cool, then the outer surface of the liner is chemically and/or mechanically etched to enhance bonding of a composite overwrap. The etched liner is wrapped with multiple layers of an epoxy resin reinforced with graphite fibers; the wrapping can be done either by manual application of epoxy-impregnated graphite cloth or by winding of epoxy-impregnated filaments. The entire assembly is heated in an autoclave to cure the epoxy. After the curing process, the multisegmented mandrel is disassembled and removed from inside, leaving the finished tank. If the tank is to be used for storing hydrogen peroxide, then the liner material

Advanced Computational and Experimental Techniques for Nacelle Liner Performance Evaluation

Science.gov (United States)

Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.; Nark, Douglas

2009-01-01

The Curved Duct Test Rig (CDTR) has been developed to investigate sound propagation through a duct of size comparable to the aft bypass duct of typical aircraft engines. The axial dimension of the bypass duct is often curved and this geometric characteristic is captured in the CDTR. The semiannular bypass duct is simulated by a rectangular test section in which the height corresponds to the circumferential dimension and the width corresponds to the radial dimension. The liner samples are perforate over honeycomb core and are installed on the side walls of the test section. The top and bottom surfaces of the test section are acoustically rigid to simulate a hard wall bifurcation or pylon. A unique feature of the CDTR is the control system that generates sound incident on the liner test section in specific modes. Uniform air flow, at ambient temperature and flow speed Mach 0.275, is introduced through the duct. Experiments to investigate configuration effects such as curvature along the flow path on the acoustic performance of a sample liner are performed in the CDTR and reported in this paper. Combinations of treated and acoustically rigid side walls are investigated. The scattering of modes of the incident wave, both by the curvature and by the asymmetry of wall treatment, is demonstrated in the experimental results. The effect that mode scattering has on total acoustic effectiveness of the liner treatment is also shown. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation to the convected Helmholtz equation are reported. The spectra of attenuation produced by the analytic model are similar to experimental results for both walls treated, straight and curved flow path, with plane wave and higher order modes incident. The numerical model is used to define the optimized resistance and reactance of a liner that significantly improves liner attenuation in the frequency range 1900-2400 Hz. A

International liner cargo shipping: a review of Part X of the Trade Practices Act 1974

OpenAIRE

Productivity Commission

2001-01-01

On 12 March 1999 the Assistant Treasurer referred Part X of the Trade Practices Act 1974 and associated regulations to the Commission for inquiry and report within six months. The Commission was to report on the appropriate arrangements for regulation of international cargo shipping services.

Flow Structures within a Helicopter Rotor Hub Wake

Science.gov (United States)

Elbing, Brian; Reich, David; Schmitz, Sven

2015-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The measurement suite included total hub drag and wake velocity measurements (LDV, PIV, stereo-PIV) at three downstream locations. The main objective was to understand the spatiotemporal evolution of the unsteady wake between the rotor hub and the nominal location of the empennage (tail). Initial analysis of the data revealed prominent two- and four-per-revolution fluid structures linked to geometric hub features persisting into the wake far-field. In addition, a six-per-revolution fluid structure was observed in the far-field, which is unexpected due to the lack of any hub feature with the corresponding symmetry. This suggests a nonlinear interaction is occurring within the wake to generate these structures. This presentation will provide an overview of the experimental data and analysis with particular emphasis on these six-per-revolution structures.

Generation of rotation and shear flow in an imploding liner

Energy Technology Data Exchange (ETDEWEB)

Hammer, J H; Ryutov, D D [Lawrence Livermore National Lab., Livermore, CA (United States)

1997-12-31

There exist several techniques that can set the liner into rotation and/or excite an embedded shear flow at any desired depth of the liner material. A common element of all these techniques is the use of properly used left-right asymmetric structures, situated either on the liner surface or embedded in the shell. Both rotation and shear flow get enhanced in the course of the liner implosion because of the angular momentum conservation. While fast enough rotation should stabilize the Rayleigh-Taylor instability near the turn-around point, the shear flow can also have a stabilizing effect on the interface. The specific model presented in the paper shows that a strong enough shear causes stabilization of a broad class of Rayleigh-Taylor perturbations. Thus, the use of left-right asymmetric structure for generation of rotation and shear flow is an interesting new option for improvement of the quality of the liner implosions. (J.U.). 4 figs., 12 refs.

Above-cutoff impedance measurements of pumping holes for the Collider Liner

International Nuclear Information System (INIS)

Walling, L.; Barts, T.; Ruiz, E.; Turner, W.; Spayd, N.

1994-04-01

A holed liner was considered for the Superconducting Super Collider (SSC) Collider Ring because of vacuum problems caused by photon-induced desorption. The liner would serve to shield the cold surface of the beam tube from the synchrotron radiation and the holes (or slots) would allow distributed pumping by gas-absorption material that could be placed between the liner and the beam tube. The impedance of holes and slots in a liner were studied by means of simulations using both MAFIA and HFSS, analytical modelling, wire measurements and electron beam measurements

Experimental Evaluation of Acoustic Engine Liner Models Developed with COMSOL Multiphysics

Science.gov (United States)

Schiller, Noah H.; Jones, Michael G.; Bertolucci, Brandon

2017-01-01

Accurate modeling tools are needed to design new engine liners capable of reducing aircraft noise. The purpose of this study is to determine if a commercially-available finite element package, COMSOL Multiphysics, can be used to accurately model a range of different acoustic engine liner designs, and in the process, collect and document a benchmark dataset that can be used in both current and future code evaluation activities. To achieve these goals, a variety of liner samples, ranging from conventional perforate-over-honeycomb to extended-reaction designs, were installed in one wall of the grazing flow impedance tube at the NASA Langley Research Center. The liners were exposed to high sound pressure levels and grazing flow, and the effect of the liner on the sound field in the flow duct was measured. These measurements were then compared with predictions. While this report only includes comparisons for a subset of the configurations, the full database of all measurements and predictions is available in electronic format upon request. The results demonstrate that both conventional perforate-over-honeycomb and extended-reaction liners can be accurately modeled using COMSOL. Therefore, this modeling tool can be used with confidence to supplement the current suite of acoustic propagation codes, and ultimately develop new acoustic engine liners designed to reduce aircraft noise.

Survivorship of Total Hip Joint Replacements Following Isolated Liner Exchange for Wear.

Science.gov (United States)

Vadei, Leone; Kieser, David C; Frampton, Chris; Hooper, Gary

2017-11-01

Liner exchange for articular component wear in total hip joint replacements (THJRs) is a common procedure, often thought to be benign with reliable outcomes. Recent studies, however, suggest high failure rates of liner exchange revisions with significant complications. The primary aim of this study was, therefore, to analyze the survivorship of isolated liner exchange for articular component wear, and secondarily to assess the influence of patient demographics (gender, age, and American Society of Anaesthesiologists [ASA] ratings) on rerevisions following isolated liner exchange for wear. A retrospective review of the 15-year New Zealand Joint Registry (1999-2014) was performed, analyzing the outcomes of isolated liner exchange for articular component wear. The survivorship as defined as rerevision with component exchange was determined and 10-year Kaplan-Meier survivorship curves were constructed. These revision rates were compared to age, gender, and ASA rating groups using a log-rank test. The 10-year survivorship of THJR following liner exchange revision for liner wear was 75.3%. If a rerevision was required, the median time to rerevision was 1.33 years with a rerevision rate of 3.33 per 100 component years (95% confidence interval 2.68-4.08/100 component years). The principle reasons for rerevision were dislocation (48.4%) and acetabular component loosening (20.9%). There was no statistically significant difference in rerevision rates based on gender, age categories, or ASA scores. THJR isolated liner exchange for liner wear is not a benign procedure with a survivorship of 75.3% at 10 years. Surgeons contemplating liner exchange revisions should be cognisant of this risk and should adequately assess component position and stability preoperatively. Copyright © 2017 Elsevier Inc. All rights reserved.

Liner system design

International Nuclear Information System (INIS)

Hutchinson, I.P.G.; Ellison, R.D.

1992-01-01

This paper discusses one of the most important regulatory and design decisions which is determining the type of liner system. The liner system includes a combination of low hydraulic conductivity and leakage control materials to be provided beneath a mine waste management unit to avoid seepage losses, which could result in an unacceptable threat to beneficial uses of ground water. This is more difficult for mine wastes than for other types of waste disposal because: The physical and chemical properties of mine wastes vary widely; The sizes )volume and areal extent) of mine waste management units is often very large so that the costs of liners can impact economic feasibility of some operations. The U.S. Congress considered the differences between mine wastes and other types of wastes when it passed the Bevill amendment to the Resource Conservation and Recovery Act (RCRA) in 1980. That amendment exempted most mine wastes from hazardous waste regulation until the United States Environmental Protection Agency (EPA) conducted a study to determine the appropriate degree of regulation for mine wastes. In 1986, the EPA issued a report recognizing that, with a few exceptions for certain processed materials, mine wastes do not present the same level of threat as other wastes and therefore should be regulated differently. An additional important factor which differentiates mine waste disposal management units form other solid waste disposal units is that, except in unusual circumstances, mine and process facilities are located where the mineral resource is being extracted. Therefore, the location of the mine waste disposal facilities cannot solely be based upon a site selection study. as a result, some mines are located where the distance or depth to a valuable water resource is relatively small, while others are located in remote desert areas with no contiguous surface water resources, and deep ground water of limited quantity and/or quality

Imploding-liner reactor nucleonic studies: the LINUS blanket

International Nuclear Information System (INIS)

Dudziak, D.J.

1977-09-01

Scoping nucleonic studies have been performed for a small imploding-liner fusion reactor concept. Tritium breeding ratio and time-dependent energy deposition rates were the primary parameters of interest in the study. Alloys of Pb and LiPb were considered for the liquid liner (blanket), and tritium breeding was found to be more than adequate with blankets less than 1 m thick. However, neutron leakages into the solid cylinder block surrounding the liquid liner are generally quite high, so considerable effort was concentrated on minimizing these values. Time-dependent calculations reveal that 89% of the energy is deposited in the blanket within 2 μs. Thus, LINUS's blanket should remain intact for the requisite neutron and gamma-ray lifetimes

Logistics hubs: an integration of transport infrastructure

CSIR Research Space (South Africa)

Botha, M

2008-07-01

Full Text Available " that have jumped on the band wagon pushing for logistics hubs to be established in their regions or within their areas of jurisdiction. The feasibility of a logistics hub is dependent on a number of criteria with access to ideally more than two...

Design of the ZTH vacuum liner

International Nuclear Information System (INIS)

Prince, P.P.

1987-01-01

The current status of the ZTH vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at 2 MA in 1990 and at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4m major radius and a 40 cm minor radius. The vacuum vessel design features which satisfy the operating parameters are defined. The liner is constructed of Inconel 625 and has a geometry which alternates sections of thin walled bellows with rigid ribs. These composite sections span between pairs of the 16 diagnostic stations to complete the torus. The thin bellows sections maximize the liner toroidal resistance and the ribs provide support and positional accuracy for the armour in relation to the conducting shell. Heat transfer from the vessel is controlled by a blanket wrap of ceramic fiber insulation and the heat flux is dissipated to a water cooling jacket in the conducting shell. 7 figs., 1 tab

Axial magnetic field injection in magnetized liner inertial fusion

Science.gov (United States)

Gourdain, P.-A.; Adams, M. B.; Davies, J. R.; Seyler, C. E.

2017-10-01

MagLIF is a fusion concept using a Z-pinch implosion to reach thermonuclear fusion. In current experiments, the implosion is driven by the Z-machine using 19 MA of electrical current with a rise time of 100 ns. MagLIF requires an initial axial magnetic field of 30 T to reduce heat losses to the liner wall during compression and to confine alpha particles during fusion burn. This field is generated well before the current ramp starts and needs to penetrate the transmission lines of the pulsed-power generator, as well as the liner itself. Consequently, the axial field rise time must exceed hundreds of microseconds. Any coil capable of being submitted to such a field for that length of time is inevitably bulky. The space required to fit the coil near the liner, increases the inductance of the load. In turn, the total current delivered to the load decreases since the voltage is limited by driver design. Yet, the large amount of current provided by the Z-machine can be used to produce the required 30 T field by tilting the return current posts surrounding the liner, eliminating the need for a separate coil. However, the problem now is the field penetration time, across the liner wall. This paper discusses why skin effect arguments do not hold in the presence of resistivity gradients. Numerical simulations show that fields larger than 30 T can diffuse across the liner wall in less than 60 ns, demonstrating that external coils can be replaced by return current posts with optimal helicity.

Design and construction of the liner plate for the Arkansas and Midland containments

International Nuclear Information System (INIS)

Wiedner, K.; Shah, G.H.; Chang-Lo, P.

1976-01-01

This paper presents the design criteria and features of the containment liner plate systems utilized for the Arkansas and Midland Nuclear Power Plant. For the Arkansas project, the liner plate system was erected in circumferential rings approximately 3 m high, and the penetration assemblies were welded into the liner after erection. For the Midland project, the liner plate system was erected in vertical segments approximately 6 m wide x 24 m high, and the penetration assemblies were welded into the liner prior to erection. The differences between the schemes are discussed. (author)

Leakage Performance of the GM + CCL Liner System for the MSW Landfill

Directory of Open Access Journals (Sweden)

Fan Jingjing

2014-01-01

Full Text Available The contaminants in the landfill leachate press pose a grave threat to environment of the soil and the groundwater beneath the landfill. Despite there being strict requirements in relevant provisions of both domestic and foreign countries for the design of the bottom liner system. Pollution of the soil and the groundwater still took place in a number of landfills because of the leakage. To investigate the leakage rate of the liner systems, the minimum design requirements of the liner systems are summarized according to the provisions of four countries, including China, USA, Germany, and Japan. Comparative analyses using one-dimensional transport model are conducted to study the leakage performance of these liner systems composed of geomembrance (GM and compacted clay layer (CCL meeting the relevant minimum design requirements. Then parametric analyses are conducted to study the effects of the hydraulic head, the thickness of GM, the hydraulic conductivity of CCL, and so forth on the leakage performance of the liner system. It is concluded that the liner system designed according to the minimum design requirements of Germany provide the best antileakage performance, while that of Japan performs the lowest. The key parameters affecting the failure time of the liner system are summarized. Finally, some suggestions for the design of the liner systems are made according to the analyses.

Corrosion failure of a BWR embedded reactor containment liner

International Nuclear Information System (INIS)

Wegemar, B.

2006-01-01

Following sixteen fuel cycles, leakage through a BWR embedded reactor containment liner (carbon steel) was discovered. Leakage was located at a penetration for electrical conductors as a result of penetrating corrosion attack. During construction, porous cement structures and air pockets/cavities were formed due to erroneous injection of grout. Corrosion attacks on the CS steel liner were located at the relatively small, active surfaces in contact with the porous cement structure. The corrosion mechanism was supposed to be anodic dissolution of the steel liner in areas with insufficient passivation. The penetrations were restored according to original design requirements. (author)

A 20 MW podded ship underwater electromagnetic signature - the alternative electric field; Signature electromagnetique sous-marine d'un paquebot de 20 MW a pods - le champ electrique alternatif

Energy Technology Data Exchange (ETDEWEB)

Lucas, B.; Henocq, H.; Rannou, C. [Delegation Generale pour l' Armement, DET/GESMA, 75 - Paris (France); Albert, Th.; Harpin, D. [ALSTOM Marine (France); Bourguet, S.; Guerin, P. [Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique, 44 (France)

2006-03-15

Today, electric podded propulsion is used for many ships, cruise liners and Navy vessels.This propulsion uses high currents in extremely low frequencies (ELFE); currents flow through electrical network, equipment and pods. These alternative currents could generate important underwater electromagnetic field. GESMA has to quantify the level of this field and its impact on the signature of this kind of ship. Then, GESMA carried out electromagnetic measurements using a multi-sensors underwater and autonomous facility named AMI. It was placed on the route of a 20 MW podded ship, at one hundred meters depth from the surface. Especially, AMI observed an alternative radiated electric field... (authors)

Transaction hubs: can tame energy market communications

Energy Technology Data Exchange (ETDEWEB)

Hamilos, C.

2002-07-01

The nature and function of transaction hubs is described in view of their growing usefulness as electric industry deregulation takes hold and with it the urgent requirement for trading partners to exchange information quickly and efficiently. The paper stresses the many difficulties involved in communications between trading partners since each partner operates under a different set of business rules, with the result that there are 'language differences' to overcome, not to mention the sheer volume of data that must be handled. To make it all work, companies turn increasingly to products like communication hubs. They are able to overcome the fact that different companies have different systems, different data formats and different business rules, and are able to help companies to package, transmit, receive and process information. The principal advantage of a hub is that no one has to learn anyone else's interface. Everyone can continue to use their own data format and transaction models. The hub supplies the protocols and processing rules needed to work with any of the partners connected to the hub. In order to achieve the level of efficiency and reliability required in a hub, certain design principles must be satisfied. These are : scalability, facilities for load balancing, availability of standard routine services, ability to recognize a process as consisting of various transactions, and a transaction as belonging to a specific process, ability to allow the user to configure expiration times around the business processes according to market rules, facility to easily configure validation rules, ability to handle exceptions, ability to interoperate with many middle-ware products, and to manage work flow in a manner that is transparent to operating personnel.

Modelagem para localização de hubs no transporte de encomendas expressas Modelling for location hubs in the express cargo transport

Directory of Open Access Journals (Sweden)

Javier Antonio Timaná Alamo

2006-12-01

Full Text Available Na presente pesquisa se propõe um modelo matemático de programação linear com variáveis binárias 0/1, para projetar a configuração de uma rede de distribuição de encomendas expressas, visando minimizar os custos e garantindo um bom nível de serviço. O modelo, que é uma modificação da formulação proposta por O’Kelly, define as posições dos hubs, a alocação deles às demais instalações físicas e a construção de roteiros com apenas uma parada intermediária, o que confere mais agilidade ao atendimento da demanda de transporte de carga. Considera-se a instalação de um único hub maior (Hub Principal, que serve como ponto de transbordo para os fluxos de carga entre as distintas regiões de um território, e um conjunto de terminais regionais (mini-hubs, servindo como ponto de conexão, unicamente, para os fluxos de carga existentes em um determinado raio de cobertura. Foram propostas extensões que incluem uma restrição da capacidade operacional do Hub Principal, para evitar seu congestionamento, e duas diferentes estratégias de induzir o aumento de fluxo de carga manipulado pelos mini-hubs. O modelo proposto e suas extensões foram aplicados ao estudo de um caso real, obtendo-se resultados consistentes e uma redução significativa no custo total da rede de distribuição da empresa analisada.This study proposes a mathematical model of linear programming with binary variables 0/1 to project the configuration of a distribution network for express cargo which aims to minimize costs and guarantee a high level of service. The model, which is a modification of the formulation proposed by O’Kelly, defines the position of the hubs, their allocation regarding the other physical installations, and the building of itineraries with only one intermediate stop, which increases agility in meeting the demand of cargo transport. It assumes the installation of a single, major hub (Main Hub, which serves as the transfer point for

DT ignition in a Z pinch compressed by an imploding liner

International Nuclear Information System (INIS)

Bilbao, L.; Bernal, L.; Linhart, J.G.; Verri, G.

2001-01-01

It has been shown that an m=0 instability of a Z pinch carrying a current of the order of 10 MA with a rise time of less than 10 ns can generate a spark capable of igniting a fusion detonation in the adjacent DT plasma channel. A possible method for generating such currents, necessary for the implosion of an initial large radius, low temperature Z pinch, can be a radial implosion of a cylindrical fast liner. The problem has been addressed in previous publications without considering the role played by an initially impressed m=0 perturbation, a mechanism indispensable for the generation of a spark. The liner-Z pinch dynamics can be solved at several levels of physical model completeness. The first corresponds to a zero dimensional model in which the liner has a given mass per unit length and a zero thickness, the plasma is compressed adiabatically and is isotropic, and there are no energy losses or Joule heating. The second level is one dimensional. The Z pinch plasma is described by the full set of MHD, two-fluid equations. The liner is treated first as thin and incompressible, and subsequently it is assumed that it has a finite thickness and is composed of a heavy ion plasma, having an artificial but realistic equation of state. Both plasma and liner are considered uniform in the Z direction and only DT reactions are considered. It is shown that, given sufficient energy and speed of the liner, the Z pinch can reach a volume ignition. The third level is two dimensional. Plasma and liner are treated as in the second level but either the Z pinch or the liner is perturbed by an m=0 non-uniformity. Provided the liner energy is high enough and the initial m=0 perturbation is correctly chosen, the final neck plasma can act as a spark for DT ignition. It is also shown that the liner energy required for generating a spark and the subsequent detonation propagation are considerably less than in the case of volume ignition. (author)

Formation of Imploding Plasma Liners for HEDP and MIF Applications - Diagnostics

Energy Technology Data Exchange (ETDEWEB)

Gilmore, Mark [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering. Dept. of Physics and Astronomy; Hsu, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Witherspoon, F. Douglas [HyperV Technologies Corp., Chantilly, VA (United States); Cassibry, Jason [Univ. of Alabama, Huntsville, AL (United States); Bauer, Bruno S. [Univ. of Nevada, Reno, NV (United States)

2015-04-27

The goal of the plasma liner experiment (PLX) was to explore and demonstrate the feasibility of forming imploding spherical plasma liners that can reach High Energy Density (HED)-relevant (~ 0.1 Mbar) pressures upon stagnation. The plasma liners were to be formed by a spherical array of 30 – 36 railgun-driven hypervelocity plasma jets (Mach 10 – 50). Due to funding and project scope reductions in year two of the project, this initial goal was revised to focus on studies of individual jet propagation, and on two jet merging physics. PLX was a collaboration between a number of partners including Los Alamos National Laboratory, HyperV Technologies, University of New Mexico (UNM), University of Alabama, Huntsville, and University of Nevada, Reno. UNM’s part in the collaboration was primary responsibility for plasma diagnostics. Though full plasma liner experiments could not be performed, the results of single and two jet experiments nevertheless laid important groundwork for future plasma liner investigations. Though challenges were encountered, the results obtained with one and two jets were overwhelmingly positive from a liner formation point of view, and were largely in agreement with predictions of hydrodynamic models.

Accurate control testing for clay liner permeability

Energy Technology Data Exchange (ETDEWEB)

Mitchell, R J

1991-08-01

Two series of centrifuge tests were carried out to evaluate the use of centrifuge modelling as a method of accurate control testing of clay liner permeability. The first series used a large 3 m radius geotechnical centrifuge and the second series a small 0.5 m radius machine built specifically for research on clay liners. Two permeability cells were fabricated in order to provide direct data comparisons between the two methods of permeability testing. In both cases, the centrifuge method proved to be effective and efficient, and was found to be free of both the technical difficulties and leakage risks normally associated with laboratory permeability testing of fine grained soils. Two materials were tested, a consolidated kaolin clay having an average permeability coefficient of 1.2{times}10{sup -9} m/s and a compacted illite clay having a permeability coefficient of 2.0{times}10{sup -11} m/s. Four additional tests were carried out to demonstrate that the 0.5 m radius centrifuge could be used for linear performance modelling to evaluate factors such as volumetric water content, compaction method and density, leachate compatibility and other construction effects on liner leakage. The main advantages of centrifuge testing of clay liners are rapid and accurate evaluation of hydraulic properties and realistic stress modelling for performance evaluations. 8 refs., 12 figs., 7 tabs.

An Endosymbiotic Evolutionary Algorithm for the Hub Location-Routing Problem

Directory of Open Access Journals (Sweden)

Ji Ung Sun

2015-01-01

Full Text Available We consider a capacitated hub location-routing problem (HLRP which combines the hub location problem and multihub vehicle routing decisions. The HLRP not only determines the locations of the capacitated p-hubs within a set of potential hubs but also deals with the routes of the vehicles to meet the demands of customers. This problem is formulated as a 0-1 mixed integer programming model with the objective of the minimum total cost including routing cost, fixed hub cost, and fixed vehicle cost. As the HLRP has impractically demanding for the large sized problems, we develop a solution method based on the endosymbiotic evolutionary algorithm (EEA which solves hub location and vehicle routing problem simultaneously. The performance of the proposed algorithm is examined through a comparative study. The experimental results show that the proposed EEA can be a viable solution method for the supply chain network planning.

Learning Graphical Models With Hubs.

Science.gov (United States)

Tan, Kean Ming; London, Palma; Mohan, Karthik; Lee, Su-In; Fazel, Maryam; Witten, Daniela

2014-10-01

We consider the problem of learning a high-dimensional graphical model in which there are a few hub nodes that are densely-connected to many other nodes. Many authors have studied the use of an ℓ 1 penalty in order to learn a sparse graph in the high-dimensional setting. However, the ℓ 1 penalty implicitly assumes that each edge is equally likely and independent of all other edges. We propose a general framework to accommodate more realistic networks with hub nodes, using a convex formulation that involves a row-column overlap norm penalty. We apply this general framework to three widely-used probabilistic graphical models: the Gaussian graphical model, the covariance graph model, and the binary Ising model. An alternating direction method of multipliers algorithm is used to solve the corresponding convex optimization problems. On synthetic data, we demonstrate that our proposed framework outperforms competitors that do not explicitly model hub nodes. We illustrate our proposal on a webpage data set and a gene expression data set.

Lean GHTorrent : GitHub data on demand

NARCIS (Netherlands)

Gousios, G.; Vasilescu, B.N.; Serebrenik, A.; Zaidman, A.

2014-01-01

In recent years, GitHub has become the largest code host in the world, with more than 5M developers collaborating across 10M repositories. Numerous popular open source projects (such as Ruby on Rails, Homebrew, Bootstrap, Django or jQuery) have chosen GitHub as their host and have migrated their

Identification of promising Twin Hub networks : Report of Work Package 1 of the Intermodal rail freight Twin hub Network Northwest Europe - project (final report)

NARCIS (Netherlands)

Kreutzberger, E.D.; Konings, J.W.; Meijer, S.; Witteveen, C.; Meijers, B.M.; Pekin, E.; Macharis, C.; Kiel, J.; Kawabata, Y.; Vos, W.

2014-01-01

This report is the first deliverable of the project Intermodal Rail Freight Twin Hub Network Northwest Europe. We call its subject Twin hub network and the organisational entity to carry out the actions the Twin hub project. The project is funded by INTERREG NWE (programme IVb). Its work started in

Location of Urban Logistic Terminals as Hub Location Problem

Directory of Open Access Journals (Sweden)

Jasmina Pašagić Škrinjar

2012-09-01

Full Text Available In this paper the problems of locating urban logistic terminals are studied as hub location problems that due to a large number of potential nodes in big cities belong to hard non-polynomial problems, the so-called NP-problems. The hub location problems have found wide application in physical planning of transport and telecommunication systems, especially systems of fast delivery, networks of logistic and distribution centres and cargo traffic terminals of the big cities, etc. The paper defines single and multiple allocations and studies the numerical examples. The capacitated single allocation hub location problems have been studied, with the provision of a mathematical model of selecting the location for the hubs on the network. The paper also presents the differences in the possibilities of implementing the exact and heuristic methods to solve the actual location problems of big dimensions i.e. hub problems of the big cities.

Altered cortical hubs in functional brain networks in amyotrophic lateral sclerosis.

Science.gov (United States)

Ma, Xujing; Zhang, Jiuquan; Zhang, Youxue; Chen, Heng; Li, Rong; Wang, Jian; Chen, Huafu

2015-11-01

Cortical hubs are highly connected nodes in functional brain networks that play vital roles in the efficient transfer of information across brain regions. Although altered functional connectivity has been found in amyotrophic lateral sclerosis (ALS), the changing pattern in functional network hubs in ALS remains unknown. In this study, we applied a voxel-wise method to investigate the changing pattern of cortical hubs in ALS. Through resting-state fMRI, we constructed whole-brain voxel-wise functional networks by measuring the temporal correlations of each pair of brain voxels and identified hubs using the graph theory method. Specifically, a functional connectivity strength (FCS) map was derived from the data on 20 patients with ALS and 20 healthy controls. The brain regions with high FCS values were regarded as functional network hubs. Functional hubs were found mainly in the bilateral precuneus, parietal cortex, medial prefrontal cortex, and in several visual regions and temporal areas in both groups. Within the hub regions, the ALS patients exhibited higher FCS in the prefrontal cortex compared with the healthy controls. The FCS value in the significantly abnormal hub regions was correlated with clinical variables. Results indicated the presence of altered cortical hubs in the ALS patients and could therefore shed light on the pathophysiology mechanisms underlying ALS.

Optimum hub height of a wind turbine for maximizing annual net profit

International Nuclear Information System (INIS)

Lee, Jaehwan; Kim, Dong Rip; Lee, Kwan-Soo

2015-01-01

Highlights: • Annual Net Profit was proposed to optimize the hub height of a wind turbine. • Procedures of the hub height optimization method were introduced. • Effect of local wind speed characteristics on optimum hub height was illustrated. • Effect of rated power on optimum hub height was negligible in the range 0.75–3 MW. • Rated speed and cut-out speed had great effects on optimum hub height. - Abstract: The optimization method of the hub height, which can ensure the economic feasibility of the wind turbine, is proposed in this study. Annual Net Profit is suggested as an objective function and the optimization procedure is developed. The effects of local wind speed and wind turbine power characteristics on the optimum hub height are investigated. The optimum hub height decreased as the mean wind speed and wind shear exponent increased. Rated power had little effect on optimum hub height; it follows that the economies of scale are negligible in the rated power range of 0.75–3 MW. Among the wind turbine power characteristics, rated speed and cut-out speed most strongly affected the optimum hub height

Analysis of Dual Mobility Liner Rim Damage Using Retrieved Components and Cadaver Models.

Science.gov (United States)

Nebergall, Audrey K; Freiberg, Andrew A; Greene, Meridith E; Malchau, Henrik; Muratoglu, Orhun; Rowell, Shannon; Zumbrunn, Thomas; Varadarajan, Kartik M

2016-07-01

The objective of this study was to assess the retentive rim of retrieved dual mobility liners for visible evidence of deformation from femoral neck contact and to use cadaver models to determine if anterior soft tissue impingement could contribute to such deformation. Fifteen surgically retrieved polyethylene liners were assessed for evidence of rim deformation. The average time in vivo was 31.4 months, and all patients were revised for reasons other than intraprosthetic dislocation. Liner interaction with the iliopsoas was studied visually and with fluoroscopy in cadaver specimens using a dual mobility system different than the retrieval study. For fluoroscopic visualization, a metal wire was sutured to the iliopsoas and wires were also embedded into grooves on the outer surface of the liner and the inner head. All retrievals showed evidence of femoral neck contact. The cadaver experiments showed that liner motion was impeded by impingement with the iliopsoas tendon in low flexion angles. When observing the hip during maximum hyperextension, 0°, 15°, and 30° of flexion, there was noticeable tenting of the iliopsoas caused by impingement with the liner. Liner rim deformation resulting from contact with the femoral neck likely begins during early in vivo function. The presence of deformation is indicative of a mechanism inhibiting mobility of the liner. The cadaver studies showed that liner motion could be impeded because of its impingement with the iliopsoas. Such soft tissue impingement may be one mechanism by which liner motion is routinely inhibited, which can result in load transfer from the neck to the rim. Copyright © 2015 Elsevier Inc. All rights reserved.

Calculation of anchor forces on penetration liners for the reactor vessel Schmehausen (Germany)

International Nuclear Information System (INIS)

Roennert, J.K.

1976-01-01

Penetrations through the walls of the single cavity PCPV Prestressed Concrete Pressure Vessel for the 300 MW(e) reactor are lined with steel penetration liners welded to the liner of the cavity. For gas-tightness of the system the penetrations are closed by covers. To secure their integration with the concrete, the liners are anchored to it by means of shear studs and/or angles. Being embedded in concrete, over the full width of the walls, the liners are exposed to lateral and longitudinal concrete deformations causing forces on the anchors. The axial blow-out force due to the pressure of the coolant on the closures must also be transferred through the anchors to the concrete. In the design of anchored penetration liners stress analyses are performed to determine anchor forces under different loading conditions and at several ages of the PCPV. The present paper deals with the mathematical estimation of the anchor forces on the basis of given concrete deformations, temperature of liners, and pressure in the vessel by the method of replacing the penetration liners and their anchors by a spring model with linear stiffness characteristics for both the liner and the anchors. An example of the computations on a digital computer is shown. (author)

A three-dimensional rupture analysis of steel liners anchored to concrete pressure and containment vessels

International Nuclear Information System (INIS)

Bangash, Y.

1987-01-01

Steel liners or plates are anchored to concrete pressure and containment vessels for nuclear and offshore facilities. Due to extreme loading conditions a liner may buckle due to the pull-out or shearing of anchors from the base metal and concrete. Under certain conditions attributed to loadings, liner metal deterioration and cracking of concrete behind the liner, the liner may fail by rupture. This paper presents a three-dimensional analysis of steel-concrete elements, using finite elements analysis in which a provision is made for liner instability, anchor strength and stiffness, concrete cracking and finally liner rupture. The analysis is tested first on an octagonal slab with and without an anchored steel liner. It is then extended to concrete pressure and containment vessels. The analytical results obtained are compared well with those available from the experimental tests and other sources. (author)

Consideration of liners and covers in performance assessments

Energy Technology Data Exchange (ETDEWEB)

Phifer, Mark A. [Savannah River National Laboratory, Aiken, SC (United States); Seitz, Robert R. [Savannah River National Laboratory, Aiken, SC (United States); Suttora, Linda C. [USDOE Enviromental Management, Washington, DC (United States)

2014-09-18

On-site disposal cells are in use and being considered at several United States Department of Energy (USDOE) sites as the final disposition for large amounts of waste associated with cleanup of contaminated areas and facilities. These disposal cells are typically regulated by States and/or the U.S. Environmental Protection Agency under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in addition to having to comply with requirements in DOE Order 435.1, Radioactive Waste Management due to the radioactive waste. The USDOE-Environmental Management Office of Site Restoration formed a working group to foster improved communication and sharing of information for personnel associated with these CERCLA disposal cells and work towards more consistent assumptions, as appropriate, for technical and policy considerations related to CERCLA risk assessments and DOE Order 435.1 performance assessments in support of a Record of Decision and Disposal Authorization Statement, respectively. One of the issues considered by the working group, which is addressed in this report, was how to appropriately consider the performance of covers and liners/leachate collections systems in the context of a DOE Order 435.1 performance assessment (PA). This same information may be appropriate for consideration within CERCLA risk assessments for these facilities. These OSDCs are generally developed to meet hazardous waste (HW) disposal design standards under the Resource Conservation and Recovery Act (RCRA) as well as the DOE Order 435.1 performance based standards for disposal of radioactive waste. To meet the standards for HW, the facilities typically include engineered covers and liner/leachate collection systems. Thus, when considering such facilities in the context of a DOE Order 435.1 PA, there is a need to address the evolution of performance of covers and liner/leachate collection systems in the context of meeting a performance standard considering time

Evaluation of flexible membrane liners as long-term barriers for uranium mill tailings

International Nuclear Information System (INIS)

1984-07-01

The National Uranium Tailings Program has commissioned a study to evaluate flexible membrane liners (geomembranes) as long-term barriers for Canadian uranium mill tailings. This study reviews the common liner type and addresses flexible liners (polymeric membranes and asphalt) in detail. Liner fabrication, design, installation, and performance are reviewed. Conceptual designs are presented for basins to accommodate 20 years accumulation of uranium tailings from mills in Elliot Lake and southeastern Athabasca. Nine polymeric and three asphalt liner types have been considered with respect to the physical and chemical environment in the uranium producing areas of Canada. All materials indicate good chemical resistance to uranium wastes but are subject to installation problems

Strength analyses of containment steel liner at the plasticity instability

International Nuclear Information System (INIS)

Klyashchitskij, V.I.; Golyakov, V.I.; Kostylev, V.I.; Margolin, B.Z.

2003-01-01

The steel liner of NPP containment plays the important role of a leak-tight contour preventing the possible releases of radioactive substances beyond the boundaries of the reactor building. However, so far in many cases an assessment of strain-stress state of the liner having initial imperfections of the shape was made with approximate methods. A new methodology for the analysis of the liner at the plasticity instability was developed at Atomenergoproekt institute in cooperation with specialists from other agencies. The methodology is based on code 'Termit'. Assessment of the critical strain was made taking into account possible presence of one or two defects: construction undercut or crack-like defect in a weld. On the base of the real structure analyses under any combinations of quasi-static loads the algorithm was developed for the computation of the liner. (author)

Tissue Friendly Pendulum: Soft Liner to prevent Tissue Irritation

Directory of Open Access Journals (Sweden)

Siddharth Shashidhar Revankar

2014-01-01

Full Text Available Palatal mucosal irritation is commonly encountered with the Pendulum appliance. The efficiency of soft liners in reducing tissue irritation has been well documented in the field of prosthodontics. The following article describes an innovative technique where soft liner can be used to reduce palatal mucosal irritation caused by pendulum appliance.

Deuterium Liner and Multiparameter Investigation of the Inverse Z-Pinch Formation Process

CERN Document Server

Bystritskii, Vyach M; Grebenyuk, V M; Parzhitsky, S S; Penkov, F M; Stolupin, V A; Boznyak, J; Gula, E; Dudkin, G N; Nechaev, B A; Padalko, V M; Mesyats, G A; Ratakhin, N A; Sorokin, S A

2001-01-01

A description of the methods and results of the measurements of the ion energy distribution of the deuterium liner accelerated in the inverse Z-pinch configuration are presented - the liner plasma is radially accelerated from the outward small radius. The knowledge of the experiment deuteron energy distribution is crucially important for correct interpretation of the results on the study of the dd-reaction at infralow collision energies using the liner plasma. Experiments were fulfilled in the HCEI (Tomsk, Russia) at a nanosecond pulsed high current generator (I=950 kA, pulse duration \\tau=80 ns). The hollow deuterium liner of 20 mm length was accelerated from the initial radius of \\sim 15 mm to 45 mm. Measurement of the liner characteristics was produced by means of the light detectors (detection of H_\\alpha and H_\\beta deuterium lines) and magnetic B-dot probes, placed on the various radii of the expanding liner. Besides, the measurement of the neutron radiation intensity due to reaction d+d\\to^{3}He+n was ...

Nuclear containment steel liner corrosion workshop : final summary and recommendation report.

Energy Technology Data Exchange (ETDEWEB)

Erler, Bryan A. (Erler Engineering Ltd., Chicago, IL); Weyers, Richard E. (Virginia Tech University, Blacksburg, VA); Sagues, Alberto (University of South Florida, Tampa, FL); Petti, Jason P.; Berke, Neal Steven (Tourney Consulting Group, LLC, Kalamazoo, MI); Naus, Dan J. (Oak Ridge National Laboratory, Oak Ridge, TN)

2011-07-01

This report documents the proceedings of an expert panel workshop conducted to evaluate the mechanisms of corrosion for the steel liner in nuclear containment buildings. The U.S. Nuclear Regulatory Commission (NRC) sponsored this work which was conducted by Sandia National Laboratories. A workshop was conducted at the NRC Headquarters in Rockville, Maryland on September 2 and 3, 2010. Due to the safety function performed by the liner, the expert panel was assembled in order to address the full range of issues that may contribute to liner corrosion. This report is focused on corrosion that initiates from the outer surface of the liner, the surface that is in contact with the concrete containment building wall. Liner corrosion initiating on the outer diameter (OD) surface has been identified at several nuclear power plants, always associated with foreign material left embedded in the concrete. The potential contributing factors to liner corrosion were broken into five areas for discussion during the workshop. Those include nuclear power plant design and operation, corrosion of steel in contact with concrete, concrete aging and degradation, concrete/steel non-destructive examination (NDE), and concrete repair and corrosion mitigation. This report also includes the expert panel member's recommendations for future research.

Report on survey on international hub

International Nuclear Information System (INIS)

Ebisawa, Hirobumi; Hoshino, Junko; Hashimoto, Kazuichiro; Okada, Sohei

2011-06-01

Japan Atomic Energy Agency (JAEA) is promoting initiative to form an international hub in line with its aim to accept more researchers/engineers from all over the world. Establishment of 'the Committee for JAEA Internationalization Initiative' was planned in 2010 so as to intensify this initiative, and in February, 2010, we visited research institutions in Europe, which include European Organization for Nuclear Research (CERN), the construction site of ITER in Cadarache, and Rutherford Appleton Laboratory (RAL), with the intention to survey and learn their advanced activities and systems in regard to the International Hub, so that the committee will be able to make fruitful discussion. This report describes strategy taken in each institution for an International Hub, and the state of each institution regarding acceptance and management of overseas researchers and engineers, research environment, living environment/health and welfare, and PR activities/coexistence with the local community. (author)

Landing Gear Door Liners for Airframe Noise Reduction

Science.gov (United States)

Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

2014-01-01

A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

Pining for home: Studying crew homesickness aboard a cruise liner ...

African Journals Online (AJOL)

Research in Hospitality Management ... Crew homesickness should be seen as important by both shipboard and liner company management because it can ultimately impact on customer service experiences, and can be ameliorated by ... Keywords: homesickness, cruise-liner, crewmembers, shipboard hotel services ...

An Improved Lubrication Model between Piston Rings and Cylinder Liners with Consideration of Liner Dynamic Deformations

Directory of Open Access Journals (Sweden)

Guoxing Li

2017-12-01

Full Text Available The friction pair of piston rings and cylinder liner is one of the most important friction couplings in an internal combustion engine. It influences engine efficiency and service life. Under the excitation of piston slaps, the dynamic deformation of cylinder liner is close to the surface roughness magnitudes, which can affect the friction and lubrication performance between the piston rings and cylinder assemblies. To investigate the potential influences of structural deformations to tribological behaviours of cylinder assemblies, the dynamic deformation of the inner surface due to pistons slaps is obtained by dynamic simulations, and then coupled into an improved lubrication model. Different from the traditional lubrication model which takes the pressure stress factor and shear stress factor to be constant, the model proposed in this paper calculated these factors in real time using numerical integration to achieve a more realistic simulation. Based on the improved piston rings and cylinder liner lubrication model, the minimum oil film thickness and friction force curves are obtained for an entire work cycle. It shows that the friction force obtained from the improved model manifests clear oscillations in each stoke, which is different from the smoothed profiles predicted traditionally. Moreover, the average amplitude of the friction forces also shows clear reduction.

Super-fast multi-wire liner implosion physics study at Angara-5-1

Energy Technology Data Exchange (ETDEWEB)

Alexandrov, V V; Branitsky, A V; Volkov, G S; Fedulov, M V; Grabovsky, E V; Nedoseev, L; Oleinik, G M; Samokhin, A N; Sasorov, F P.V.; Smirnov, V P; Frolov, I N; Zaitzev, V I; Zurin, M V [GSC Troitsk Institute for Innovation and Fusion Research, Troitsk, Moscow region (Russian Federation); Spielman, R B; Deeney, C [Sandia National Labs., Albuquerque, NM (United States)

2000-07-01

The temporally dragged plasma production (TDPP) from dense substance of tungsten wire occurs during multi-wire-liner implosion. TDPP is the typical feature of wire liner implosion. In spite of plasma filling of the initial liner cavity, a narrow pulse (up to 6 ns) of X rays is radiated for an 0.3-mm inter-wire gap. (authors)

Super-fast multi-wire liner implosion physics study at Angara-5-1

International Nuclear Information System (INIS)

Alexandrov, V.V.; Branitsky, A.V.; Volkov, G.S.; Fedulov, M.V.; Grabovsky, E.V.; Nedoseev, L.; Oleinik, G.M.; Samokhin, A.N.; Sasorov, F.P.V.; Smirnov, V.P.; Frolov, I.N.; Zaitzev, V.I.; Zurin, M.V.; Spielman, R.B.; Deeney, C.

2000-01-01

The temporally dragged plasma production (TDPP) from dense substance of tungsten wire occurs during multi-wire-liner implosion. TDPP is the typical feature of wire liner implosion. In spite of plasma filling of the initial liner cavity, a narrow pulse (up to 6 ns) of X rays is radiated for an 0.3-mm inter-wire gap. (authors)

Contoured-gap coaxial guns for imploding plasma liner experiments

Science.gov (United States)

Witherspoon, F. D.; Case, A.; Brockington, S.; Cassibry, J. T.; Hsu, S. C.

2014-10-01

Arrays of supersonic, high momentum flux plasma jets can be used as standoff compression drivers for generating spherically imploding plasma liners for driving magneto-inertial fusion, hence the name plasma-jet-driven MIF (PJMIF). HyperV developed linear plasma jets for the Plasma Liner Experiment (PLX) at LANL where two guns were successfully tested. Further development at HyperV resulted in achieving the PLX goal of 8000 μg at 50 km/s. Prior work on contoured-gap coaxial guns demonstrated an approach to control the blowby instability and achieved substantial performance improvements. For future plasma liner experiments we propose to use contoured-gap coaxial guns with small Minirailgun injectors. We will describe such a gun for a 60-gun plasma liner experiment. Discussion topics will include impurity control, plasma jet symmetry and topology (esp. related to uniformity and compactness), velocity capability, and techniques planned for achieving gun efficiency of >50% using tailored impedance matched pulse forming networks. Mach2 and UAH SPH code simulations will be included. Work supported by US DOE DE-FG02-05ER54810.

Progress In Magnetized Target Fusion Driven by Plasma Liners

Science.gov (United States)

Thio, Francis Y. C.; Kirkpatrick, Ronald C.; Knapp, Charles E.; Cassibry, Jason; Eskridge, Richard; Lee, Michael; Smith, James; Martin, Adam; Wu, S. T.; Schmidt, George;

Acoustic Panel Liner for an Engine Nacelle

Science.gov (United States)

Jones, Michael G. (Inventor); Nark, Douglas M. (Inventor); Ayle, Earl (Inventor); Ichihashi, Fumitaka (Inventor)

2016-01-01

An acoustic panel liner includes a face sheet, back plate, and liner core positioned there-between, which may be used in an engine nacelle. Elongated chambers contain variable amounts of septa at a calibrated depth or depths. The septa may have varying DC flow resistance. The chambers may have a hexagonal or other polygonal cross sections. The septa, such as mesh caps, may be bonded to an inner wall of a corresponding chamber. The insertion depths may be the same or different. If different, the pattern of distribution of the depths may be randomized.

Numerical investigation of hub clearance flow in a Kaplan turbine

Science.gov (United States)

Wu, H.; Feng, J. J.; Wu, G. K.; Luo, X. Q.

2012-11-01

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

Numerical investigation of hub clearance flow in a Kaplan turbine

International Nuclear Information System (INIS)

Wu, H; Feng, J J; Wu, G K; Luo, X Q

2012-01-01

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

A Finite Element Theory for Predicting the Attenuation of Extended-Reacting Liners

Science.gov (United States)

Watson, W. R.; Jones, M. G.

2009-01-01

A non-modal finite element theory for predicting the attenuation of an extended-reacting liner containing a porous facesheet and located in a no-flow duct is presented. The mathematical approach is to solve separate wave equations in the liner and duct airway and to couple these two solutions by invoking kinematic constraints at the facesheet that are consistent with a continuum theory of fluid motion. Given the liner intrinsic properties, a weak Galerkin finite element formulation with cubic polynomial basis functions is used as the basis for generating a discrete system of acoustic equations that are solved to obtain the coupled acoustic field. A state-of-the-art, asymmetric, parallel, sparse equation solver is implemented that allows tens of thousands of grid points to be analyzed. A grid refinement study is presented to show that the predicted attenuation converges. Excellent comparison of the numerically predicted attenuation to that of a mode theory (using a Haynes 25 metal foam liner) is used to validate the computational approach. Simulations are also presented for fifteen porous plate, extended-reacting liners. The construction of some of the porous plate liners suggest that they should behave as resonant liners while the construction of others suggest that they should behave as broadband attenuators. In each case the finite element theory is observed to predict the proper attenuation trend.

Failure mechanisms and closed reduction of a constrained tripolar acetabular liner.

Science.gov (United States)

Robertson, William J; Mattern, Christopher J; Hur, John; Su, Edwin P; Pellicci, Paul M

2009-02-01

Unlike traditional bipolar constrained liners, the Osteonics Omnifit constrained acetabular insert is a tripolar device, consisting of an inner bipolar bearing articulating within an outer, true liner. Every reported failure of the Omnifit tripolar implant has been by failure at the shell-bone interface (Type I failure), failure at the shell-liner interface (Type II failure), or failure of the locking mechanism resulting in dislocation of the bipolar-liner interface (Type III failure). In this report we present two cases of failure of the Omnifit tripolar at the bipolar-femoral head interface. To our knowledge, these are the first reported cases of failure at the bipolar-femoral head interface (Type IV failure). In addition, we described the first successful closed reduction of a Type IV failure.

A versatile framework for cooperative hub network development

NARCIS (Netherlands)

Cruijssen, F.C.A.M.; Borm, P.; Dullaert, W.; Hamers, H.

2010-01-01

This paper introduces a framework for cooperative hub network development. Building a joint physical hub for the transshipment of goods is expensive and, therefore, involves considerable risks for cooperating companies. In a practical setting, it is unlikely that an entire network will be built at

A versatile framework for cooperative hub network development

NARCIS (Netherlands)

Cruijssen, Frans; Borm, Peter; Dullaert, Wout; Hamers, Herbert

This paper introduces a framework for cooperative hub network development. Building a joint physical hub for the transshipment of goods is expensive and, therefore, involves considerable risks for cooperating companies. In a practical setting, it is unlikely that an entire network will be built at

Flap Side Edge Liners for Airframe Noise Reduction

Science.gov (United States)

Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

2014-01-01

One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

International Education Hubs: Collaboration for Competitiveness and Sustainability

Science.gov (United States)

Knight, Jane

2014-01-01

This chapter focuses on the development of education hubs, a recent phenomenon in international higher education. Three models of hubs are examined in relation to the forces, risks, and opportunities of globalization and how local and international collaborations are essential for both global competitiveness and sustainability.

Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.; Ayle, Earl; Ichihashi, Fumitaka

2014-01-01

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more desirable. This paper describes improvements to a previously established broadband acoustic liner optimization process using the Advanced Noise Control Fan rig as a demonstrator. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom designs are carried through design, fabrication, and testing to validate the efficacy of the design process. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of these liner designs. This study also provides an application for demonstrating the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

Use of x-ray radiographic methods in the study of clay liners

International Nuclear Information System (INIS)

Malone, P.G.; May, J.H.; Brown, K.W.; Thomas, J.C.

1986-01-01

X-ray radiography has been widely used in soil investigation to study the distribution of layers in soil cores and the effects of changing conditions (loading or impact) on soil structure. X-ray radiographic techniques also can be useful in studying clays or clay soils used in liners. Laboratory investigations were undertaken to demonstrate that X-ray radiographic techniques could be used to detect density and soil structure changes that usually accompany variations in hydraulic conductivity of clay liners. An example of a real-time test of a simulated bentonite and sand, liner attacked with acid lead nitrate and examples of radiographic examination of clay soil (non-calcareous smectite) samples that have been permeated by lead acetate or lead nitrate are presented. The changes in density and structure can be related to changes observed in hydraulic conductivity during permeation. X-ray radiography easily can be applied to field samples of soil or clay liner materials to detect density and structural changes that occur as the liner and permeating fluid interact. X-ray techniques have applications in both understanding failure mechanisms and forecasting liner performance

Writing and Music: Album Liner Notes

Directory of Open Access Journals (Sweden)

Dean Leonard Biron

2011-09-01

Full Text Available A deceptive aspect of the ‘writing about music is like dancing about architecture’ cliché is the function of the preposition ‘about’. Literature and music, dance and architecture, painting and film – all are discrete aesthetic forms that nonetheless simultaneously feed off and provide nourishment for each other as part of art’s perpetual drive toward diversity and innovation. Nowhere is the aptness of the association between writing and music more obvious than in the phenomenon of album liner notes. Rather than merely an attempt at describing or translating musical experience, liner notes contribute to the dialogue between composer and listener and are a significant part of the culture of contemporary music.

Development of an improved low profile hub seal refurbishment tool

International Nuclear Information System (INIS)

Wagg, L.

1997-01-01

The hub seal area of a fuel channel feeder coupling can be exposed to oxygen in the atmosphere if protective measures are not taken during maintenance outages. Exposure to oxygen can lead to pitting of the hub seal area. Although this is a rare occurrence, the resulting possibility of the feeder coupling leakage led to the development of a feeder hub refurbishment tool. To reduce time and man-rem exposure during feeder hub seal refurbishment, an improved low profile hub seat refurbishing tool has been developed. The improved tool design will allow for quick and controlled removal of material, and the restoration of a roll-burnished finish equivalent to the original requirements. The new tool can be used in maintenance operations, with the end fitting present, as well as under retube-type circumstances, with the end fitting removed. (author)

Effect of liner non-uniformity on plasma instabilities in an inverse Z-pinch magnetized target fusion system: liner-on-plasma simulations and comparison with linear stability analysis

International Nuclear Information System (INIS)

Subhash, P V; Madhavan, S; Chaturvedi, S

2008-01-01

Two-dimensional (2D) magneto-hydrodynamic (MHD) liner-on-plasma computations have been performed to study the growth of instabilities in a magnetized target fusion system involving the cylindrical compression of an inverse Z-pinch target plasma by a metallic liner. The growth of modes in the plasma can be divided into two phases. During the first phase, the plasma continues to be Kadomtsev stable. The dominant mode in the liner instability is imposed upon the plasma in the form of a growing perturbation. This mode further transfers part of its energy to its harmonics. During the second phase, however, non-uniform implosion of the liner leads to axial variations in plasma quantities near the liner-plasma interface, such that certain regions of the plasma locally violate the Kadomtsev criteria. Further growth ofthe plasma modes is then due to plasma instability. The above numerical study has been complemented with a linear stability analysis for the plasma, the boundary conditions for this analysis being obtained from the liner-on-plasma simulation. The stability of axisymmetric modes in the first phase is found to satisfy the Kadomtsev condition Q 0 1 modes, using equilibrium profiles from the 2D MHD study, shows that their growth rates can exceed those for m=0 by as much as an order of magnitude

Applied algorithm in the liner inspection of solid rocket motors

Science.gov (United States)

Hoffmann, Luiz Felipe Simões; Bizarria, Francisco Carlos Parquet; Bizarria, José Walter Parquet

2018-03-01

In rocket motors, the bonding between the solid propellant and thermal insulation is accomplished by a thin adhesive layer, known as liner. The liner application method involves a complex sequence of tasks, which includes in its final stage, the surface integrity inspection. Nowadays in Brazil, an expert carries out a thorough visual inspection to detect defects on the liner surface that may compromise the propellant interface bonding. Therefore, this paper proposes an algorithm that uses the photometric stereo technique and the K-nearest neighbor (KNN) classifier to assist the expert in the surface inspection. Photometric stereo allows the surface information recovery of the test images, while the KNN method enables image pixels classification into two classes: non-defect and defect. Tests performed on a computer vision based prototype validate the algorithm. The positive results suggest that the algorithm is feasible and when implemented in a real scenario, will be able to help the expert in detecting defective areas on the liner surface.

Effect of radiation losses on the compression of hydrogen by imploding solid liners

International Nuclear Information System (INIS)

Hussey, T.W.; Kiuttu, G.F.; Degnan, J.H.; Peterkin, R.E.; Smith, G.A.; Turchi, P.J.

1996-01-01

Quasispherical solid liner implosions with little or no instability growth have been achieved experimentally. Applications for such implosions include the uniform, shock-free compression of some sort of on-axis target. One proposed means of obtaining such compression is to inject a 1 eV hydrogen plasma working fluid between the liner and the target, and imploding the liner around it. the high initial temperature assures that the sound speed within the liner is always greater than the inner surface implosion velocity of the liner, and the initial density is chosen so that the volume of the working fluid at peak compression is sufficiently large so that perfectly spherical convergence of the liner is not required. One concern with such an approach is that energy losses associated with ionization and radiation will degrade the effective gamma of the compression. To isolate and, therefore, understand these effects the authors have developed a simple zero-dimensional model for the liner implosion that accurately accounts for the shape and thickness of the liner as it implodes and compresses the working fluid. Based on simple considerations they make a crude estimate of the range of initial densities of interest for this technique. They then observe that within this density rage, for the temperatures of interest, the lines are strongly self-absorbed so that the transport of radiation is dominated by bound-free and free-free processes

The Logistical Challenges of the SpaceLiner Concept

OpenAIRE

van Foreest, Arnold; Sippel, Martin

2008-01-01

The SpaceLiner concept developed at DLR combines extremely fast transport (90 minutes from Europe to Australia) with the experience of Space flight. As such it is different from the spaceflight which focuses exclusively on space tourism but it combines space tourism with for example business travel. The SpaceLiner is designed to carry 50 passengers in suborbital flight. The conceptual technical design presents some challenges which have already been partially investigated at DLR [1]. However,...

Integrated technology rotor/flight research rotor hub concept definition

Science.gov (United States)

Dixon, P. G. C.

1983-01-01

Two variations of the helicopter bearingless main rotor hub concept are proposed as bases for further development in the preliminary design phase of the Integrated Technology Rotor/Flight Research Rotor (ITR/FRR) program. This selection was the result of an evaluation of three bearingless hub concepts and two articulated hub concepts with elastomeric bearings. The characteristics of each concept were evaluated by means of simplified methodology. These characteristics included the assessment of stability, vulnerability, weight, drag, cost, stiffness, fatigue life, maintainability, and reliability.

E-hubs: the new B2B (business-to-business) marketplaces.

Science.gov (United States)

Kaplan, S; Sawhney, M

2000-01-01

Electronic hubs--Internet-based intermediaries that host electronic marketplaces and mediate transactions among businesses--are generating a lot of interest. Companies like Ariba, Chemdex, and Commerce One have already attained breathtaking stock market capitalizations. Venture capitalists are pouring money into more business-to-business start-ups. Even industrial stalwarts like GM and Ford are making plans to set up their own Web markets. As new entrants with new business models pour into the business-to-business space, it's increasingly difficult to make sense of the landscape. This article provides a blueprint of the e-hub arena. The authors start by looking at the two dimensions of purchasing: what businesses buy--manufacturing inputs or operating inputs--and how they buy--through systematic sourcing or spot sourcing. They classify B2B e-hubs into four categories: MRO hubs, yield managers, exchanges, and catalog hubs, and they discuss each type in detail. Drilling deeper into this B2B matrix, the authors look at how e-hubs create value--through aggregation and matching--and explain when each mechanism works best. They also examine the biases of e-hubs. Although many e-hubs are neutral--they're operated by independent third parties--some favor the buyers or sellers. The authors explain the differences and discuss the pros and cons of each position. The B2B marketplace is changing rapidly. This framework helps buyers, sellers, and market makers navigate the landscape by explaining what the different hubs do and how they add the most value.

Effects of tacky mat contamination on bond degradation for Chemlok/liner and NBR/liner bonds

Science.gov (United States)

Padilla, A. M.

1989-01-01

Tacky mats are placed by the rubber lay-up areas for the solid rocket motor segments. These mats dust off the shoes prior to entering the platform where the lay-up work is performed. The possibility exists that a tacky mat could be touched with gloved hands prior to handling the uncured nitride butadiene rubber (NBR). Tests were run to determine if NBR were accidentally touched would there be any degradation of the liner/NBR bond. The tacky mats were judged solely on the basis of bond degradation caused by either direct or indirect contamination. Test results all indicate that there was no notable NBR/Chemlok or liner/NBR bond degradation on samples that came into contact with the tacky mat material. Testing procedures are described. The tacky mat adhesive composition does not contain fluorocarbons or release agents that would affect bonding.

Rehabilitation of underwater pipeline with liner; Reabilitacao de aqueduto submarino com liner: multiplas vantagens e aplicacoes

Energy Technology Data Exchange (ETDEWEB)

Aquino, Roberto S.; Oliveira, Jose N. de; Urtiga, Rogerio L.; Witt, R. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2008-07-01

The system of water injection in XAREU oil production field has an water pipeline sizing 4'' of diameter, between the offshore platform PXA-1 and another PXA-2, that it transfers 165 m{sup 3}/d of salt water for pressurization of the reservoir through the injection well Xareu-23. This water pipeline always presented high degree of corrosion needing frequently installation of cramps to eliminate leakages. After evaluating the costs we conclude that the more attractive it would be the installation of a liner than the launching of a new water pipeline. For the installation of a new water pipeline we would need the approval of IBAMA and of a great number of resources for the substitution of that pipeline. In spite of treating of an unpublished service between two offshore platforms we chose for the installation of a liner, because we had a great technological domain in this service in onshore oil production facilities with many pipelines recovered with this technique. We had to revise all of the procedures so that there was not any surprise to make unfeasible this service. The installation of the system liner, consisted of an internal coating 'in situ' through the insert of plastic tubes(high density polyethylene-HDPE), that it forms a barrier between the pipeline and the transported fluid. (author)

Stroke mimics under the drip-and-ship paradigm.

Science.gov (United States)

Mehta, Sonal; Vora, Nirav; Edgell, Randall C; Allam, Hesham; Alawi, Aws; Koehne, Jennifer; Kumar, Abhay; Feen, Eliahu; Cruz-Flores, Salvador; Alshekhlee, Amer

2014-01-01

Recent reports suggested better outcomes associated with the drip-and-ship paradigm for acute ischemic stroke (AIS) treated with thrombolysis. We hypothesized that a higher rate of stroke mimics (SM) among AIS treated in nonspecialized stroke centers that are transferred to comprehensive centers is responsible for such outcomes. Consecutive patients treated with thrombolysis according to the admission criteria were reviewed in a single comprehensive stroke center over 1 academic year (July 1, 2011 to June 30, 2012). Information on the basic demographic, hospital complications, psychiatric diagnoses, and discharge disposition was collected. We identified those patients who were treated at a facility and then transferred to the tertiary center (ie, drip-and-ship paradigm). In addition to comparative and adjusted analysis to identify predictors for SM, a stratified analysis by the drip-and-ship status was performed. One hundred twenty patients were treated with thrombolysis for AIS included in this analysis; 20 (16.7%) were discharged with the final diagnosis of SM; 14 of those had conversion syndrome and 6 patients had other syndromes (seizures, migraine, and hypoglycemia). Patients with SM were younger (55.6 ± 15.0 versus 69.4 ± 14.9, P = .0003) and more likely to harbor psychiatric diagnoses (45% versus 9%; P ≤ .0001). Eighteen of 20 SM patients (90%) had the drip-and-ship treatment paradigm compared with 65% of those with AIS (P = .02). None of the SM had hemorrhagic complications, and all were discharged to home. Predictors of SM on adjusted analysis included the drip-and-ship paradigm (odds ratio [OR] 12.8, 95% confidence interval [CI] 1.78, 92.1) and history of any psychiatric illness (OR 12.08; 95% CI 3.14, 46.4). Eighteen of 83 drip-and-ship patients (21.7%) were diagnosed with SM compared with 2 of 37 patients (5.4%) presented directly to the hub hospital (P = .02). The drip-and-ship paradigm and any psychiatric history predict the diagnosis of

Development of imploding liners with kinetic energies > 100 MJ and their applications

International Nuclear Information System (INIS)

Reinovsky, R.E.; Ekdahl, C.A.

1996-01-01

The Los Alamos program in High Energy Density Physics is developing high performance imploding liners as sources of high energy density environments for experimental physics applications. High performance liners are, for these purposes, liners with high velocity, 100 MJ or more kinetic energy at 20-50 MJ/cm of height. They must have sufficient azimuthal symmetry, axial uniformity and density to perform as high quality impactors on central, cylindrical targets. Scientific applications of such liners are numerous and varied. For example, the properties of materials at extreme energy densities can be assessed in such an experimental environment. The physics of plasmas near solid density can be studied and hydrodynamics experiments at high Mach number (above 5?) in materials that are near solid density and significantly ionized can be conducted. In addition, liners with substantial kinetic energy and good integrity at velocities of one to a few cm/microsec make good implosion drivers for fusion plasmas in the context of magnetized target fusion and MAGO

Design, engineering and evaluation of refractory liners for slagging gasifiers. Final report

Energy Technology Data Exchange (ETDEWEB)

deTineo, B J; Booth, G; Firestone, R F; Greaves, M J; Hales, C; Lamoureux, J P; Ledford, R R

1982-08-01

The contract for this program was awarded at the end of September 1978. Work was started on 1 October 1978, on Tasks A, B, and E. Task A, Conceptual Liner Designs, and Task B, Test System Design and Construction, were completed. Task C, Liner Tests, and Task D, Liner Design Evaluation, were to begin upon completion of Task B. Task E, Liner Model Development, is inactive after an initial data compilation and theoretical model development effort. It was to be activated as soon as data were available from Task D. Task F, Liner Design Handbook, was active along with Task A since the reports of both tasks were to use the same format. At this time, Tasks C, D, and F are not to be completed since funding of this project was phased out by DOE directive. The refractory text facility, which was constructed, was tested and found to perform satisfactorily. It is described in detail, including a hazard analysis which was performed. (LTN)

The effect of surface roughness on the performances of liner-piston ...

African Journals Online (AJOL)

The effect of surface roughness on the performances of liner-piston ring contact in internal combustion engine. ... The surface roughness between the liner and the piston rings, plays an ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Sodium leak and combustion experiment-II report. Evaluation result of damage of mild steel liner

Energy Technology Data Exchange (ETDEWEB)

Aoto, K.; Hirakawa, Y.; Kuroda, T. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1996-09-01

Several material analyses on damage of the floor liner made of a mild steel which was in the test cell of the second sodium leak and combustion experiment (Test-2) performed in OEC/PNC on June 7 in 1996 were carried out to clarify the following issues. (1) Difference of the corrosion mechanism of Test-2 liner to that of the first sodium leak and combustion experiment (Test-1) liner. (2) The vital factor which can desides corrosion mechanism and damage location. The following analyses were accomplished. (1) Microstructure observation, (2) EPMA for cross-section of vicinity of corroded area, (3) X-ray diffraction (XRD) for the interface between corrosion product-liner (mild steel). The differences between the corrosion mechanism of Test-1 liner which is seemed to be the same that of `MONJU` liner and that of Test-2 liner is discussed based on the results of these material analyses. As the result, the Na-Fe double oxidization with mechanical/chemical removal of reaction product can be occurred on the Test-1 and `MONJU` liner. On the other hand, a hot-corrosion, that is the molten salt type corrosion is subject to be thinning of the Test-2 liner. All failures of Test-2 liner surround at the halfway up a convex. Considering the above corrosion mechanism, that fact leads that significant damage is occurred at the molten salt level. (author)

Spatial Pattern and Regional Relevance Analysis of the Maritime Silk Road Shipping Network

Directory of Open Access Journals (Sweden)

Naixia Mou

2018-03-01

Full Text Available Under the strategy of “One Belt and One Road”, this paper explores the spatial pattern and the status quo of regional trade relevance of the Maritime Silk Road shipping network. Based on complex network theory, a topological structure map of shipping networks for containers, tankers, and bulk carriers was constructed, and the spatial characteristics of shipping networks were analyzed. Using the mode of spatial arrangement and the Herfindahl–Hirschman Index, this paper further analyzes the traffic flow pattern of regional trade of three kinds of goods. It is shown that the shipping network of containers, tankers and bulk carriers are unevenly distributed and have regional agglomeration phenomena. There is a strong correlation between the interior of the region and the adjacent areas, and the port competition is fierce. Among them, the container ships network is the most competitive in the region, while the competitiveness of the tankers network is relatively the lowest. The inter-regional correlation is weak, and a few transit hub ports have obvious competitive advantages. The ports in Northeast Asia and Southeast Asia are the most significant. The research results combined with the Maritime Silk Road policy can provide reference for port construction, route optimization, and coordinated development of regional trade, which will help to save time and cost of marine transportation, reduce energy consumption, and promote the sustainable development of marine environment and regional trade on the Maritime Silk Road.

A new approach to the design of LMFBR liners

International Nuclear Information System (INIS)

Polentz, L.M.

1980-01-01

An advance in the state-of-the-art of LMFBR liners which permits notable savings in construction costs without any sacrifice of safety is described. The application of the new design concept to the rework of the upper reactor vault liner of the FFTF is discussed. Factors which affect the application of the new design approach to other LMFBRs are delineated and discussed. (author)

Formation of imploding plasma liners for fundamental HEDP studies and MIF Standoff Driver Concept

Energy Technology Data Exchange (ETDEWEB)

Cassibry, Jason [Univ. of AL in Huntsville; Hatcher, Richard [Univ. of AL in Huntsville; Stanic, Milos [Univ. of AL in Huntsville

2013-08-17

The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ~ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear fusion relevant parameters.

Sci-Hub provides access to nearly all scholarly literature.

Science.gov (United States)

Himmelstein, Daniel S; Romero, Ariel Rodriguez; Levernier, Jacob G; Munro, Thomas Anthony; McLaughlin, Stephen Reid; Greshake Tzovaras, Bastian; Greene, Casey S

2018-03-01

The website Sci-Hub enables users to download PDF versions of scholarly articles, including many articles that are paywalled at their journal's site. Sci-Hub has grown rapidly since its creation in 2011, but the extent of its coverage has been unclear. Here we report that, as of March 2017, Sci-Hub's database contains 68.9% of the 81.6 million scholarly articles registered with Crossref and 85.1% of articles published in toll access journals. We find that coverage varies by discipline and publisher, and that Sci-Hub preferentially covers popular, paywalled content. For toll access articles, we find that Sci-Hub provides greater coverage than the University of Pennsylvania, a major research university in the United States. Green open access to toll access articles via licit services, on the other hand, remains quite limited. Our interactive browser at https://greenelab.github.io/scihub allows users to explore these findings in more detail. For the first time, nearly all scholarly literature is available gratis to anyone with an Internet connection, suggesting the toll access business model may become unsustainable. © 2018, Himmelstein et al.

Acoustic Liner Drag: Measurements on Novel Facesheet Perforate Geometries

Science.gov (United States)

Howerton, Brian M.; Jones, Michael G.

2016-01-01

Interest in characterization of the aerodynamic drag of acoustic liners has increased in the past several years. This paper details experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of several perforate-over-honeycomb liner configurations at flow speeds of centerline flow Mach number equals 0.3 and 0.5. Various perforate geometries and orientations are investigated to determine their resistance factors using a static pressure drop approach. Comparison of these resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 hertz at source sound pressure levels of 140 and 150 decibels. Educed impedance and attenuation spectra are used to determine the impact of variations in perforate geometry on acoustic performance.

A Branch and Cut algorithm for the container shipping network design problem

DEFF Research Database (Denmark)

Reinhardt, Line Blander; Kallehauge, Brian; Pisinger, David

The network design problem in liner shipping is of increasing importance in a strongly competitive market where potential cost reductions can influence market share and profits significantly. In this paper the network design and fleet assignment problems are combined into a mixed integer linear...... programming model minimizing the overall cost. To better reflect the real-life situation we take into account the cost of transhipment, a heterogeneous fleet, route dependant capacities, and butterfly routes. To the best of our knowledge it is the first time an exact solution method to the problem considers...... transhipment cost. The problem is solved with branch-and-cut using clover and transhipment inequalities. Computational results are reported for instances with up to 15 ports....

Multi-Item Distribution Policies with Supply Hub and Lateral Transshipment

OpenAIRE

Zhong Jin-Hong; Jiang Rui-Xuan; Zheng Gui

2015-01-01

Supply Hub is defined as the horizontal coordination among the suppliers while lateral transshipment is a horizontal coordination policy among the retailers. By considering the Supply Hub and lateral transshipment simultaneously, ones can reduce the total cost of the supply chain system and improve the response to customer requirement and the customers’ satisfaction. We investigate the distribution policies for the supply chain which consists of multisuppliers, single Supply Hub, and multidis...

Field performance assessment of synthetic liners for uranium tailings ponds: a status report

International Nuclear Information System (INIS)

Mitchell, D.H.; Spanner, G.E.

1984-03-01

The objective of this study is to provide a database to support US Nuclear Regulatory Commission (NRC) licensing of uranium tailings leachate isolation impoundments. This objective is being accomplished by determining the effectiveness of design, installation, and quality assurance practices associated with uranium mill tailings impoundments with flexible membrane liners. The program includes testing of chemical resistance and physical performance of liners, leak detection systems, and seam inspection techniques. This report presents the status of the program through September 1983. The report addresses impoundment design, installation, and inspection techniques used by the uranium milling industry. To determine the relative successes of these techniques, information has been collected from consultants, mill operators, and the synthetic liner industry. Progress in experimental tasks on chemical resistance of liners, physical properties of liners, and nondestructive examination of seams is reported. 25 references, 9 figures, 13 tables

Revisiting date and party hubs: novel approaches to role assignment in protein interaction networks.

Directory of Open Access Journals (Sweden)

Sumeet Agarwal

2010-06-01

Full Text Available The idea of "date" and "party" hubs has been influential in the study of protein-protein interaction networks. Date hubs display low co-expression with their partners, whilst party hubs have high co-expression. It was proposed that party hubs are local coordinators whereas date hubs are global connectors. Here, we show that the reported importance of date hubs to network connectivity can in fact be attributed to a tiny subset of them. Crucially, these few, extremely central, hubs do not display particularly low expression correlation, undermining the idea of a link between this quantity and hub function. The date/party distinction was originally motivated by an approximately bimodal distribution of hub co-expression; we show that this feature is not always robust to methodological changes. Additionally, topological properties of hubs do not in general correlate with co-expression. However, we find significant correlations between interaction centrality and the functional similarity of the interacting proteins. We suggest that thinking in terms of a date/party dichotomy for hubs in protein interaction networks is not meaningful, and it might be more useful to conceive of roles for protein-protein interactions rather than for individual proteins.

Some features of liners convergence accelerated with the help of powerful EMGs

Energy Technology Data Exchange (ETDEWEB)

Grinevich, B E; Chernyshev, V K; Buzin, V N; Petrukhin, A A; Zarionov, E I [All-Russian Science and Research Institute of Experimental Physics, Sarov (Russian Federation)

1997-12-31

Described are experiments devoted to the convergence of condensed liners, non-exploding during the flight, under the influence of current. To feed the liners with a power of not less than 25 MJ, powerful explosive magnetic 1000 mm diameter generators were used. Interesting effects arising during the liners flight were observed. A comparison of experimental results and calculations carried out using the SMOG program, showed that the calculated current was 20% higher than the observed current. At the same time, the experimental speed exceeded the rated speed calculated according to the known current curve. The asymmetry of current distribution along the liners was defined depending on time. Some conclusions concerning the current spread symmetry are made. (author). 4 figs., 1 ref.

Critical interfaces in geosynthetic multilayer liner system of a landfill

Directory of Open Access Journals (Sweden)

Qian Xuede

2008-12-01

Full Text Available This study is to identify the critical interface in a geosynthetic multilayer liner system by examining the effects of the interface shear strength of liner components, leachate level, leachate buildup cases, and peak and residual interface strengths. According to current landfill design procedures, conducting stability analysis along the same interface at both the back slope and base may result in a non-conservative result. The critical interfaces with the minimum factor of safety are generally found at different locations along the back slope and base. The critical interface for a multilayer liner system cannot simply be assumed during stability analysis. It can shift from one interface to another with changes in the leachate level and with different leachate buildup cases. The factor of safety for an interface with a high friction angle and low apparent cohesion generally drops much more quickly than it does under inverse conditions when the leachate level increases. The failure interface in a liner system under residual conditions is usually different from the failure interface under peak conditions.

Engineering design of the LINUS-O prototype liner implosion system

International Nuclear Information System (INIS)

Turchi, P.J.; Jenkins, D.J.; Warnick, W.L.; Ford, R.D.; Lanham, R.; Cooper, A.L.; Burton, R.L.

1977-01-01

The development of imploding liner flux compression techniques for application to compact, pulsed fusion reactors has led to the concept of rotating liquid metal implosions driven by free-pistons. In hydrodynamic model tests, such implosions have been demonstrated to be stable and reversible, allowing serious consideration of a new class of pulsed fusion reactor. The next step is to demonstrate repetitive, controlled operation at high energy densities with liquid metal liners, for which peak magnetic field levels approaching a megagauss are possible. A prototype controlled liner implosion system, LINUS-O, has been designed and is under construction. During operation, the annular driving-piston surrounding the implosion chamber is displaced axially by the action of pulsed high pressure gas at several hundred atmospheres. The piston and chamber rotate at 2100 RPM, allowing the free inside surface of the liner to implode stably from 30 cm diameter to 1.0 cm at turnaround. The experimental facility is described and engineering problems associated with design and operation of controlled high energy implosion systems are discussed

Design of the ZTH vacuum liner

International Nuclear Information System (INIS)

Prince, P.P.; Dike, R.S.

1987-01-01

The current status of the ZTH vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4 m major radius and a 40 cm minor radius. Operating parameters which drive the vacuum vessel mechanical design include a 300 C bakeout temperature, an armour support system capable of withstanding 25 kV, a high toroidal resistance, 1250 kPa magnetic loading, a 10 minute cycle time, and high positional accuracy with respect to the conducting shell. The vacuum vessel design features which satisfy the operating parameters are defined. The liner is constructed of Inconel 625 and has a geometry which alternates sections of thin walled bellows with rigid ribs. These composite sections span between pairs of the 16 diagnostic stations to complete the torus. The thin bellows sections maximize the liner toroidal resistance and the ribs provide support and positional accuracy for the armour in relation to the conducting shell. Heat transfer from the vessel is controlled by a blanket wrap of ceramic fiber insulation and the heat flux is dissipated to a water cooling jacket in the conducting shell

Experimental plans for LMFBR cavity liner sodium spill test LT-1

International Nuclear Information System (INIS)

Hilliard, R.K.; Newell, G.A.

1976-01-01

Reinforced concrete is an important material of construction in LMFBR cavities and cells. Steel liners are often installed on the concrete surfaces to provide a gastight seal for minimizing air inleakage to inerted cell atmospheres and to protect the concrete from direct contact with sodium in the event of a sodium spill. In making safety assessment analyses, it is of interest to determine the adequacy of the liners to maintain their leaktightness during postulated accidents involving large sodium spills. However, data for basing analytical assessments of cell liners are very meager and an experimental program is underway at HEDL to provide some of the needed information. The HEDL cell liner evaluation program consists of both bench-scale feature tests and large-scale sodium spill demonstration tests. The plans for the first large-scale sodium spill test (LT-1) are the subject of this paper

Classification of gene expression data: A hubness-aware semi-supervised approach.

Science.gov (United States)

Buza, Krisztian

2016-04-01

Classification of gene expression data is the common denominator of various biomedical recognition tasks. However, obtaining class labels for large training samples may be difficult or even impossible in many cases. Therefore, semi-supervised classification techniques are required as semi-supervised classifiers take advantage of unlabeled data. Gene expression data is high-dimensional which gives rise to the phenomena known under the umbrella of the curse of dimensionality, one of its recently explored aspects being the presence of hubs or hubness for short. Therefore, hubness-aware classifiers have been developed recently, such as Naive Hubness-Bayesian k-Nearest Neighbor (NHBNN). In this paper, we propose a semi-supervised extension of NHBNN which follows the self-training schema. As one of the core components of self-training is the certainty score, we propose a new hubness-aware certainty score. We performed experiments on publicly available gene expression data. These experiments show that the proposed classifier outperforms its competitors. We investigated the impact of each of the components (classification algorithm, semi-supervised technique, hubness-aware certainty score) separately and showed that each of these components are relevant to the performance of the proposed approach. Our results imply that our approach may increase classification accuracy and reduce computational costs (i.e., runtime). Based on the promising results presented in the paper, we envision that hubness-aware techniques will be used in various other biomedical machine learning tasks. In order to accelerate this process, we made an implementation of hubness-aware machine learning techniques publicly available in the PyHubs software package (http://www.biointelligence.hu/pyhubs) implemented in Python, one of the most popular programming languages of data science. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Inductively Driven, 3D Liner Compression of a Magnetized Plasma to Megabar Energy Densities

Energy Technology Data Exchange (ETDEWEB)

Slough, John [MSNW LLC, Redmond, WA (United States)

2015-02-01

To take advantage of the smaller scale, higher density regime of fusion an efficient method for achieving the compressional heating required to reach fusion gain conditions must be found. What is proposed is a more flexible metallic liner compression scheme that minimizes the kinetic energy required to reach fusion. It is believed that it is possible to accomplish this at sub-megajoule energies. This however will require operation at very small scale. To have a realistic hope of inexpensive, repetitive operation, it is essential to have the liner kinetic energy under a megajoule which allows for the survivability of the vacuum and power systems. At small scale the implosion speed must be reasonably fast to maintain the magnetized plasma (FRC) equilibrium during compression. For limited liner kinetic energy, it becomes clear that the thinnest liner imploded to the smallest radius consistent with the requirements for FRC equilibrium lifetime is desired. The proposed work is directed toward accomplishing this goal. Typically an axial (Z) current is employed for liner compression. There are however several advantages to using a θ-pinch coil. With the θ-pinch the liner currents are inductively driven which greatly simplifies the apparatus and vacuum system, and avoids difficulties with the post implosion vacuum integrity. With fractional flux leakage, the foil liner automatically provides for the seed axial compression field. To achieve it with optimal switching techniques, and at an accelerated pace however will require additional funding. This extra expense is well justified as the compression technique that will be enabled by this funding is unique in the ability to implode individual segments of the liner at different times. This is highly advantageous as the liner can be imploded in a manner that maximizes the energy transfer to the FRC. Production of shaped liner implosions for additional axial compression can thus be readily accomplished with the modified power

Development of laser cutting method for stainless steel liner

International Nuclear Information System (INIS)

Ishihara, Satoshi; Takahata, Masato; Wignarajah, Sivakumaran; Kamata, Hirofumi

2007-01-01

The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in nuclear facilities. The effect of basic laser cutting parameters such as energy, cutting speed, assist gas flow etc. were first studied through cutting experiments on mock-up concrete specimens lined with 3mm thick stainless steel sheets using a 1kW Nd:YAG laser. These initial studies were followed by further studies on the effect of unevenness of the liner surface and on a new method of confining contamination during the cutting process using a sliding evacuation hood attached to the laser cutting head. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. (author)

Repairing liner of the reactor

International Nuclear Information System (INIS)

Aguilar H, F.

2001-07-01

Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

High Thermal Conductivity NARloy-Z-Diamond Composite Liner for Advanced Rocket Engines

Science.gov (United States)

Bhat, Biliyar; Greene, Sandra

2015-01-01

NARloy-Z (Cu-3Ag-0.5Zr) alloy is state-of-the-art combustion chamber liner material used in liquid propulsion engines such as the RS-68 and RS-25. The performance of future liquid propulsion systems can be improved significantly by increasing the heat transfer through the combustion chamber liner. Prior work1 done at NASA Marshall Space Flight Center (MSFC) has shown that the thermal conductivity of NARloy-Z alloy can be improved significantly by embedding high thermal conductivity diamond particles in the alloy matrix to form NARloy-Z-diamond composite (fig. 1). NARloy-Z-diamond composite containing 40vol% diamond showed 69% higher thermal conductivity than NARloy-Z. It is 24% lighter than NARloy-Z and hence the density normalized thermal conductivity is 120% better. These attributes will improve the performance and life of the advanced rocket engines significantly. The research work consists of (a) developing design properties (thermal and mechanical) of NARloy-Z-D composite, (b) fabrication of net shape subscale combustion chamber liner, and (c) hot-fire testing of the liner to test performance. Initially, NARloy-Z-D composite slabs were made using the Field Assisted Sintering Technology (FAST) for the purpose of determining design properties. In the next step, a cylindrical shape was fabricated to demonstrate feasibility (fig. 3). The liner consists of six cylinders which are sintered separately and then stacked and diffusion bonded to make the liner (fig. 4). The liner will be heat treated, finish-machined, and assembled into a combustion chamber and hot-fire tested in the MSFC test facility (TF 115) to determine perform.

Fabrication Process for Machined and Shrink-Fitted Impactor-Type Liners for the LOS Alamos Hedp Program

Science.gov (United States)

Randolph, B.

2004-11-01

Composite liners have been fabricated for the Los Alamos liner-driven High Energy Density Physics (HEDP) experiments using impactors formed by physical vapor deposition, and by machining and shrink fitting. Chemical vapor deposition has been proposed for some ATLAS liner applications. This paper describes the processes used to fabricate machined and shrink-fitted impactors; these processes have been used for copper impactors in 1100 aluminum liners and for 6061 T-6 aluminum impactors in 1100 aluminum liners. The most successful processes have been largely empirically developed and rely upon a combination of shrink-fitting and light press fitting. The processes used to date will be described along with some considerations for future composite liners for the HEDP Program.

Flow Merging and Hub Route Optimization in Collaborative Transportation

Directory of Open Access Journals (Sweden)

Kerui Weng

2014-01-01

Full Text Available This paper studies the optimal hub routing problem of merged tasks in collaborative transportation. This problem allows all carriers’ transportation tasks to reach the destinations optionally passing through 0, 1, or 2 hubs within limited distance, while a cost discount on arcs in the hub route could be acquired after paying fixed charges. The problem arises in the application of logistics, postal services, airline transportation, and so forth. We formulate the problem as a mixed-integer programming model, and provide two heuristic approaches, respectively, based on Lagrangian relaxation and Benders decomposition. Computational experiments show that the algorithms work well.

Predicting the binding patterns of hub proteins: a study using yeast protein interaction networks.

Directory of Open Access Journals (Sweden)

Carson M Andorf

Full Text Available Protein-protein interactions are critical to elucidating the role played by individual proteins in important biological pathways. Of particular interest are hub proteins that can interact with large numbers of partners and often play essential roles in cellular control. Depending on the number of binding sites, protein hubs can be classified at a structural level as singlish-interface hubs (SIH with one or two binding sites, or multiple-interface hubs (MIH with three or more binding sites. In terms of kinetics, hub proteins can be classified as date hubs (i.e., interact with different partners at different times or locations or party hubs (i.e., simultaneously interact with multiple partners.Our approach works in 3 phases: Phase I classifies if a protein is likely to bind with another protein. Phase II determines if a protein-binding (PB protein is a hub. Phase III classifies PB proteins as singlish-interface versus multiple-interface hubs and date versus party hubs. At each stage, we use sequence-based predictors trained using several standard machine learning techniques.Our method is able to predict whether a protein is a protein-binding protein with an accuracy of 94% and a correlation coefficient of 0.87; identify hubs from non-hubs with 100% accuracy for 30% of the data; distinguish date hubs/party hubs with 69% accuracy and area under ROC curve of 0.68; and SIH/MIH with 89% accuracy and area under ROC curve of 0.84. Because our method is based on sequence information alone, it can be used even in settings where reliable protein-protein interaction data or structures of protein-protein complexes are unavailable to obtain useful insights into the functional and evolutionary characteristics of proteins and their interactions.We provide a web server for our three-phase approach: http://hybsvm.gdcb.iastate.edu.

Skin-Inspired Hydrogel-Elastomer Composite with Application in a Moisture Permeable Prosthetic Limb Liner

Science.gov (United States)

Ruiz, Esteban

Recent advances in fields such as 3D printing, and biomaterials, have enabled the development of a moisture permeable prosthetic liner. This project demonstrates the feasibility of the invention by addressing the three primary areas of risk including the mechanical strength, the permeability, and the ability to manufacture. The key enabling technology which allows the liner to operate is the skin inspired hydrogel elastomer composite. The skin inspiration is reflected in the molecular arrangement of the double network of polymers which mimics collagen-elastin toughening in the natural epidermis. A custom formulation for a novel tough double network nanocomposite reinforced hydrogel was developed to improve manufacturability of the liner. The liner features this double network nanocomposite reinforced hydrogel as a permeable membrane which is reinforced on either side by perforated silicone layers manufactured by 3d printing assisted casting. Uniaxial compression tests were conducted on the individual hydrogels, as well as a representative sample of off the shelf prosthetic liners for comparison. Permeability testing was also done on the same set of materials and compared to literature values for traditional hydrogels. This work led to the manufacture of three generations of liner prototypes, with the second and third liner prototype being tested with human participants.

One-dimensional MHD simulations of MTF systems with compact toroid targets and spherical liners

Science.gov (United States)

Khalzov, Ivan; Zindler, Ryan; Barsky, Sandra; Delage, Michael; Laberge, Michel

2017-10-01

One-dimensional (1D) MHD code is developed in General Fusion (GF) for coupled plasma-liner simulations in magnetized target fusion (MTF) systems. The main goal of these simulations is to search for optimal parameters of MTF reactor, in which spherical liquid metal liner compresses compact toroid plasma. The code uses Lagrangian description for both liner and plasma. The liner is represented as a set of spherical shells with fixed masses while plasma is discretized as a set of nested tori with circular cross sections and fixed number of particles between them. All physical fields are 1D functions of either spherical (liner) or small toroidal (plasma) radius. Motion of liner and plasma shells is calculated self-consistently based on applied forces and equations of state. Magnetic field is determined by 1D profiles of poloidal and toroidal fluxes - they are advected with shells and diffuse according to local resistivity, this also accounts for flux leakage into the liner. Different plasma transport models are implemented, this allows for comparison with ongoing GF experiments. Fusion power calculation is included into the code. We performed a series of parameter scans in order to establish the underlying dependencies of the MTF system and find the optimal reactor design point.

Computational concept for the containment liner for a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Nagelstutz, Franz; Anders, Nils [Babcock Noell GmbH, Wuerzburg (Germany). Abt. Berechnung

2010-05-15

The determination of the optimal design of the Containment Liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. Several load cases for normal operation and accidental conditions as well as severe accidents have been analyzed. A realistic consideration of impacts by accidents was especially difficult. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. An integrated concept from planning, manufacturing and erection of this large component has been implemented, which is the topic of the speech 'ENGINEERING AND INNOVATIVE ERECTION CONCEPT FOR THE CONTAINMENT LINER FOR AN EPR trademark ' given by Dr. Rainer Goehring, Babcock Noell GmbH, Division Nuclear Technology Projects, Wuerzburg. He demonstrates that within the given time frame, with the required quality and within the required tolerances the containment liner can be erected. (orig.)

Development of Adaptive Acoustic Impedance Control Technologies of Acoustic Duct Liner

Directory of Open Access Journals (Sweden)

Hiroshi Kobayashi

2011-01-01

Full Text Available This paper describes the development of adaptive acoustic impedance control (AAC technologies to achieve a larger fan noise reduction, by adaptively adjusting reactance and resistance of the acoustic liner impedance. For the actual proof of the AAC technology III performance, the advanced fan noise absorption control duct liner II was made on trial basis, with the simple control system and the plain device. And, then, the duct liner II was examined for the AAC technology I, II, and III models, using the high speed fan test facility. The test results made clear that the duct liner II of the AAC technology III model could achieve the fan noise reduction higher than O.A. SPL 10 dB (A at the maximum fan speed 6000 rpm, containing the reduction of fundamental BPF tone of 18 dB and 2nd BPF tone of 10 dB in response to the fan peed change from 3000 to 6000 rpm.

Climate programs update: USDA Southwest Regional Climate Hub update

Science.gov (United States)

PROGRAM OVERVIEW: The overarching goal of the USDA SW Climate Hub is to assist farmers, ranchers and foresters in addressing the effects of climate change including prolonged drought, increased insect outbreaks and severe wildfires. In the first year of operations, the SW Climate Hub (est. Februa...

Hub Status and Indexation of Container Ports

Directory of Open Access Journals (Sweden)

Yong-An Park

2015-06-01

This study develops two sub-indexes of port classification and capacity, and combines cases of these two sub-indexes into various types in order to find a proper port hub index. The paper demonstrates how different types of port hub index are useful measurements for evaluating outputs and inputs of container ports. In a case analysis we show that the indexes of period variables and lagged variables have more explanatory power with regard to changes of port throughputs and high correlation with inputs.

Rigid-flexible coupling dynamics of three-dimensional hub-beams system

International Nuclear Information System (INIS)

Liu Jinyang; Lu Hao

2007-01-01

In the previous research of the coupling dynamics of a hub-beam system, coupling between the rotational motion of hub and the torsion deformation of beam is not taken into account since the system undergoes planar motion. Due to the small longitudinal deformation, coupling between the rotational motion of hub and the longitudinal deformation of beam is also neglected. In this paper, rigid-flexible coupling dynamics is extended to a hub-beams system with three-dimensional large overall motion. Not only coupling between the large overall motion and the bending deformation, but also coupling between the large overall motion and the torsional deformation are taken into account. In case of temperature increase, the longitudinal deformation caused by the thermal expansion is significant, such that coupling between the large overall motion and the longitudinal deformation is also investigated. Combining the characteristics of the hybrid coordinate formulation and the absolute nodal coordinate formulation, the system generalized coordinates include the relative nodal displacement and the slope of each beam element with respect to the body-fixed frame of the hub, and the variables related to the spatial large overall motion of the hub and beams. Based on precise strain-displacement relation, the geometric stiffening effect is taken into account, and the rigid-flexible coupling dynamic equations are derived using velocity variational principle. Finite element method is employed for discretization. Simulation of a hub-beams system is used to show the coupling effect between the large overall motion and the torsional deformation as well as the longitudinal deformation. Furthermore, conservation of energy in case of free motion is shown to verify the formulation

Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses

International Nuclear Information System (INIS)

Glowka, D.A.

1990-09-01

This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs

Shaping the Microstructure of Cast Iron Automobile Cylinder Liners Aimed at Providing High Service Properties

Directory of Open Access Journals (Sweden)

Orłowicz A.W.

2015-06-01

Full Text Available The paper presents an analysis of factors affecting the wear of cylinder liners. The effect of the graphite precipitation morphology on the cylinder liner wear mechanism is presented. Materials used to cast cylinder liners mounted in a number of engines have been examined for their conformity with requirements set out in applicable Polish industrial standard. A casting for a prototype cylinder liner has been made with a microstructure guaranteeing good service properties of the part.

Comparative evaluation of 2% sodium fluoride iontophoresis and other cavity liners beneath silver amalgam restorations

Directory of Open Access Journals (Sweden)

Gupta M

2010-06-01

Full Text Available Background: This study was designed to compare 2% sodium fluoride (NaF iontophoresis with other cavity liners. Materials and Methods: This study was carried out in 30 patients in the age group 10-14 years with bilateral carious permanent first molars. The study evaluated the use of 2% NaF iontophoresis as a cavity liner and also compared its desensitizing effect with varnish and an adhesive bonded liner. Sensitivity gradings were done on a subjective verbal rating scale. Results: All the liner treatments decreased the sensitivity following liner application. However, decrease of sensitivity in the case of 2% NaF iontophoresis was more compared with that of varnish and adhesive bonded liner. The results were statistically significant. Conclusions: It was found that 2% NaF iontophoresis was more effective in reducing the postoperative sensitivity compared with that of varnish and scotchbond multipurpose.

Method for baking a liner in thermonuclear device

International Nuclear Information System (INIS)

Yamamoto, Keiichi.

1978-01-01

Purpose: To attain effective baking for liners in a tokamak device by connecting the narrow portions and the wide portions of the liners with dielectric materials and supplying a constant current to these portions. Method: Split type liners disposed in the vacuum vessel of a thermonuclear device are connected with dielectric materials at their wide portions and narrow portions and they are baked by supplying a constant current at a same density to the wide and narrow portions to rise their temperature uniformly. The wide portions are formed in such a way that the sum of their cross sectional areas is equal to the sum of the cross sectional areas of the narrow portions, and they form a parallel circuit. The parallel circuit consisting of the wide portions and the parallel circuit consisting of the narrow portions are connected in series to each other and connected to the constant current supply circuit, by which a constant current is supplied to the wide and the narrow portions. (Moriyama, K.)

Use of clays as liners in solar ponds

Energy Technology Data Exchange (ETDEWEB)

Silva, Gerardo [Facultad de Ingenieria, Universidad Anahuac Mexico Norte, Huixquilucan, Edo. de Mexico 52786 (Mexico); Almanza, Rafael [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D.F. 04510 (Mexico)

2009-06-15

An alternative to synthetic materials for use in solar pond liners is to select clayey soils as hydraulic barriers. This option reduces the cost of construction and the risk of contamination of subsoil and groundwater by hot brines. This paper deals with the physical, chemical and hydraulic properties of different soils tested mainly as compacted clay liners. The underdeveloped nations have the option to use this type of liner, but before doing so several tests are recommended, including those for soil and water composition, permeability, plasticity and X-ray diffraction analysis. In this investigation the following samples are analyzed: native clayey soils with illite, montmorillonite and halloysite, treated and non-treated bentonites in powder and granulated form, a mixture of zeolite and sodium bentonite, and industrial minerals composed largely of halloysite, kaolinite and attapulgite selected clays. Neutral salt aqueous solutions (NaCl and KCl) at different concentrations and under temperature gradients were used for compatibility testing conducted on these specimens. Experiment setup and particular testing procedures are also discussed. (author)

Aging test results of an asphalt membrane liner

International Nuclear Information System (INIS)

Buelt, J.L.; Barnes, S.M.

1983-07-01

The objective of the asphalt aging study described in this report was to determine the expected performance lifetime of a catalytically airblown asphalt membrane as a seepage barrier for inactive uranium mill tailings. The study, conducted by Pacific Northwest Laboratory for the Department of Energy's Uranium Mill Tailings Remedial Action Program, showed through chemical compatibility tests that the asphalt membrane is well suited for this purpose. The chemical compatibility tests were designed to accelerate the aging reactions in the asphalt and to determine the accelerated aging effect. Higher temperatures and oxygen concentrations proved to be effective acceleration parameters. By infrared spectral analysis, the asphalt was determined to have undergone 7 years of equivalent aging in a 3-month period when exposed to 40 0 C and 1.7 atm oxygen pressure. However, the extent of aging was limited to a maximum penetration of 0.5% of the total liner thickness. It was concluded that the liner could be expected to be effective as a seepage barrier for at least 1000 years before the entire thickness of the liner would be degraded

Liner velocity, current, and symmetry measurements on the 32 MA flux compression generator experiment ALT-1

CERN Document Server

Clark, D A; Rodríguez, G; Tabaka, L J

2001-01-01

Summary form only given, as follows. A flux compression generator based pulse power system, designed, built, and fielded by a Russian team at the All Russian Scientific Research Institute of Experimental Physics (VNIIEF), was used to successfully drive an aluminum liner to velocities greater than 10 km/sec. The experiment objective was to demonstrate performance of a precision liner implosion at Atlas current of 30 MA or greater. Diagnostics to measure liner performance were an essential part of the experiment. An experimental team from Los Alamos National Laboratory (LANL) provided a suite of diagnostics to measure liner performance. Three diagnostics were fielded. 1. a velocity interferometer (VISAR) to continuously measure the liner inner surface velocity from throughout the entire range of travel. 2. Two Faraday rotation devices to measure liner current during the implosion. 3. Sixteen fiber optic impact pins to record liner impact time and provide axial and azimuthal symmetry information. All diagnostics...

Utilization of sepiolite materials as a bottom liner material in solid waste landfills.

Science.gov (United States)

Guney, Yucel; Cetin, Bora; Aydilek, Ahmet H; Tanyu, Burak F; Koparal, Savas

2014-01-01

Landfill bottom liners are generally constructed with natural clay soils due to their high strength and low hydraulic conductivity characteristics. However, in recent years it is increasingly difficult to find locally available clay soils that satisfy the required engineering properties. Fine grained soils such as sepiolite and zeolite may be used as alternative materials in the constructions of landfill bottom liners. A study was conducted to investigate the feasibility of using natural clay rich in kaolinite, sepiolite, zeolite, and their mixtures as a bottom liner material. Unconfined compression tests, swell tests, hydraulic conductivity tests, batch and column adsorption tests were performed on each type of soil and sepiolite-zeolite mixtures. The results of the current study indicate that sepiolite is the dominant material that affects both the geomechanical and geoenvironmental properties of these alternative liners. An increase in sepiolite content in the sepiolite-zeolite mixtures increased the strength, swelling potential and metal adsorption capacities of the soil mixtures. Moreover, hydraulic conductivity of the mixtures decreased significantly with the addition of sepiolite. The utilization of sepiolite-zeolite materials as a bottom liner material allowed for thinner liners with some reduction in construction costs compared to use of a kaolinite-rich clay. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fixed-axis electric sail deployment dynamics analysis using hub-mounted momentum control

Science.gov (United States)

Fulton, JoAnna; Schaub, Hanspeter

2018-03-01

The deployment dynamics of a spin stabilized electric sail (E-sail) with a hub-mounted control actuator are investigated. Both radial and tangential deployment mechanisms are considered to take the electric sail from a post-launch stowed configuration to a fully deployed configuration. The tangential configuration assumes the multi-kilometer tethers are wound up on the exterior of the spacecraft hub, similar to yo-yo despinner configurations. The deployment speed is controlled through the hub rate. The radial deployment configuration assumes each tether is on its own spool. Here both the hub and spool rate are control variables. The sensitivity of the deployment behavior to E-sail length, maximum rate and tension parameters is investigated. A constant hub rate deployment is compared to a time varying hub rate that maintains a constant tether tension condition. The deployment time can be reduced by a factor of 2 or more by using a tension controlled deployment configuration.

Elastic-plastic cyclic deformation of the TEXTOR 94 modified liner under conditions of heating and plasma disruption

International Nuclear Information System (INIS)

Bohn, F.H.; Czymek, G.; Giesen, B.; Bondarchuk, E.; Doinikov, N.; Kozhukhovskaja, N.; Panin, A.

2001-01-01

The present liner of the TEXTOR 94 tokamak installed inside the vacuum vessel represents the thin toroidal shell that is rested on the vessel inner surface. In order to integrate the dynamic ergodic divertor into the tokamak the liner design has been drastically changed. The 120 deg. sector of the liner shell facing the ergodic coils system is removed and some additional holes in the liner are provisioned. This demands a new liner supporting system allowing for the liner thermal expansion and taking the electromagnetic load occurring in the liner during plasma disruption. The cyclic elasto-plastic deformations of the liner caused by the electromagnetic forces and temperature rise have been studied. It is shown that the local plastic deformations occur in the liner elements after the first heating and electromagnetic loading. The most thermal stresses take place in the reinforcing structures around the holes because of the thermal expansion difference of the inconel shell and the steel reinforcements. These stresses are coupled with the bending stress due to the electromagnetic loading. Subsequent repetitive loading does not lead to any significant increment of the plastic deformation. After the materials' hardening the structure cyclically works mostly in the elastic range

Nonlinear analysis of the GFRP material wheel hub

Directory of Open Access Journals (Sweden)

Dong Yun-Feng

2015-01-01

Full Text Available In this paper, the current bicycle wheel was replaced by the ones which composed by the wheel hub with Glassfiber Reinforced Plastic (alkali free thin-walled cylinder material, hereinafter referred to as GFRP material and the protective components made up of rubber outer pneumatic pad. With the help of the basic theory of elastic-plastic mechanics, the finite element “Nonlinear buckling” analysis of the wheel was carried out. The results show that the maximum elastic deformation of the wheel hub and the critical value of buckling failure load were restricted by the elasticity under the condition of external loads. Considering with the tensile strength and elastic modulus of the GFRP value of the material, it is demonstrated that the material is feasible to be used for wheel hub.

Aerogel Use as a Skin Protective Liner In Space Suits and Prosthetic Limbs Project

Science.gov (United States)

Roberson, Luke Bennett

2014-01-01

Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications for use in space suits and orthopedics. Three tests were performed on several types of aerogel to assess the properties of each material, and our initial findings demonstrated that these materrials would be excellent candidates for liner applications for prosthetics and space suits. The project is currently on hold until additional funding is obtained for application testing at the VH Hospitals in Tampa

Assessment of the slowly-imploding liner (LINUS) fusion reactor concept

International Nuclear Information System (INIS)

Miller, R.L.; Krakowski, R.A.

1980-01-01

Prospects for the slowly-imploding liner (LINUS) fusion reactor concept are reviewed. The concept envisages the nondestructive, repetitive and reversible implosion of a liquid-metal cylindrical annulus (liner) onto field-reversed DT plasmoids. Adiabatic heating of the plasmoid to ignition at ultra-high magnetic fields results in a compact, high power density fusion reactor with unique solutions to several technological problems and potentially favorable economics

Managing effective and efficient hub operations : a study of ground time management

NARCIS (Netherlands)

Yunita, Theresia

2009-01-01

This Logistics Design Project was carried out at KLM Aircraft Services (AS), from February 2008 - April 2009. The project focuses on ideal description of KLM operational controls for daily executions at the hub and within the AS processes. The daily execution at the hub is managed by the Hub Control

Assessment of structural integrity of Monju steel liner against sodium leakage and combustion. Modeling of thinning process of liner due to corrosion in structural analysis

International Nuclear Information System (INIS)

Tsukimori, K.; Kato, T.; Furuhashi, I.; Iwata, K.; Akatsu, M.

2001-01-01

The lining structure of LMFBR (Liquid Metal cooled Fast Breeder Reactor) has an important role to prohibit leaking sodium from touching a concrete floor in a sodium leakage incident. JNC (Japan Nuclear Cycle Development Institute) experienced a sodium leakage incident in 1995 in the secondary heat transport system room of the prototype LMFBR MONJU. In this incident, a part of the liner was covered with a certain amount of high temperature leaked sodium and its compounds. Visible but small distortion and thinning of the liner were detected, which were due to heating by sodium fire and chemical corrosion, respectively. To simulate the MONJU incident, JNC conducted a series of sodium leakage tests, in one of which severer corrosion (molten salt type corrosion) than that in the MONJU incident was observed. In order to secure the conservativeness in the integrity assessment of the liner, consideration of a severest corrosion process was demanded. This means that the loss of parts of the structure with time should be considered in the structural analyses. In this study a modeling of thinning process of the liner was developed in order to realize reasonable analysis from the point of view of actual phenomena. The concept of the method is to release the stress of the lost region by using artificial creep and reducing Young's modulus. The necessity of this kind of model and the validity was verified through an application analysis of the liner in the secondary heat transport system room of MONJU. (authors)

Assessment of structural integrity of Monju steel liner against sodium leakage and combustion. Strain criterion of the liner material

Energy Technology Data Exchange (ETDEWEB)

Asayama, T.; Koi, M. [Japan Nuclear Cycle Development Institute, Ibaraki (Japan)

2001-07-01

In a postulated condition of sodium leakage and combustion in the secondary heat transfer system of the prototype Japanese fast breeder reactor Monju, thermal stresses raise in steel liners installed to prevent sodium from contacting to concrete. Excessive strain due to the thermal stresses leads to failure of the liner. This paper proposes a strain criterion below that the mechanical integrity of liner is assured. In-plane thermal expansion causes membrane strain and out-of-plane expansion causes bending strain. Therefore, failure modes to be taken into account are tensile fracture and bending fracture. The strain criterion can be determined based on tensile and bending tests. Tensile tests and three-point bending tests were performed at the temperature range from room temperature to 1000 C. Fracture elongation was measured in both tests. Uniform elongation was also measured in tensile tests. Various factors that can affect the above experimental results, multi-axiality, environmental effects, and creep were examined. Based on the above results, the strain criterion was determined. The criterion is 10% for membrane strain and 30% for membrane plus bending strain in the temperature range of 350 C to 1000 C. For the temperatures less than 350 C, the half of those values is used. (author)

Selection of Liner Materials and Design of Hazardous Water Facilities in Saudi Arabia

Directory of Open Access Journals (Sweden)

Sahel N. Abduljauwad

2001-12-01

Full Text Available Rapid development in Saudi Arabia has produced a broad spectrum of wastes.  In the last two decades, several refineries and petrochemical industries have been established. These industries have produced sludges and other toxic wastes which need proper planning for their handling and disposal. This paper covers design and selection of liner materials for two hazardous waste disposal sites. One of them is located in the Eastern Province of Saudi Arabia, while the second one is located in the Western part. The paper will present complete design details of the natural compacted and geosynthetic soil liners and the leachate collection and removal system for primary liners and leak detection/leachate collection and removal system for secondary liners.

Mechanical Design, Analysis, and Testing of a Two-Bladed Wind Turbine Hub

Energy Technology Data Exchange (ETDEWEB)

Cotrell, J.

2002-06-01

Researchers at the National Wind Technology Center (NWTC) in Golden, Colorado, began performing the Unsteady Aerodynamics Experiment in 1993 to better understand the unsteady aerodynamics and structural responses of horizontal-axis wind turbines. The experiment consists of an extensively instrumented, downwind, three-bladed, 20-kilowatt wind turbine. In May 1995, I received a request from the NWTC to design a two-bladed hub for the experiment. For my thesis, I present the results of the mechanical design, analysis, and testing of the hub. The hub I designed is unique because it runs in rigid, teetering, or independent blade-flapping modes. In addition, the design is unusual because it uses two servomotors to pitch the blades independently. These features are used to investigate new load reduction, noise reduction, blade pitch optimization, and yaw control techniques for two-bladed turbines. I used a methodology by G. Phal and W. Bietz to design the hub. The hub meets all the performance specifications except that it achieves only 90% of the specified teeter range. In my thesis, I focus on the analysis and testing of the hub body. I performed solid-mechanics calculations, ran a finite-element analysis simulation, and experimentally investigated the structural integrity of the hub body.

Synthesis of new aluminum nano hybrid composite liner for energy saving in diesel engines

International Nuclear Information System (INIS)

Tiruvenkadam, N.; Thyla, P.R.; Senthilkumar, M.; Bharathiraja, M.; Murugesan, A.

2015-01-01

Highlights: • Nano hybrid composite cylinder liner (NL) was developed to replace cast iron liner. • NL improved engine performance, combustion and reduced emissions except NO x . • Teardown analysis provides the suitability of NL for diesel engine. • The developed aluminum NL saved 43.75% of weight than cast iron cylinder liner. - Abstract: This work aims to replace the conventional cast iron cylinder liner (CL) in diesel engine by introducing lightweight aluminum (Al) 6061 nano hybrid composite cylinder liner (NL) by analyzing the performance, combustion, and emission characteristics of an engine. NL was fabricated by bottom pouring stir casting technique with nano- and micro-reinforcement materials. Experimental results proved that the use of NL increased brake thermal efficiency, in-cylinder pressure, heat release rate, and reduced carbon monoxide, hydrocarbon, and smoke emission in comparison with CL. However, oxides of nitrogen slightly increased with the use of the new liner. No differences in wear or other issues were noted during the engine teardown after 1 year of operation and 2000 h of running. Thus, NL has been recommended to replace the CL to save the energy and to reap environmental benefits

Uranium-mill-tailings remedial-action project (UMTRAP) cover and liner technology development project

International Nuclear Information System (INIS)

Hartley, J.N.; Gee, G.W.; Freeman, H.D.; Cline, J.F.; Beedlow, P.A.; Buelt, J.L.; Relyea, J.R.; Tamura, T.

1982-01-01

Cover and liner systems for uranium mill tailings in the United States must satisfy stringent requirements regarding long-term stability, radon control, and radionuclide and hazardous chemical migration. The cover placed over a tailings pile serves three basic purposes: (1) to reduce the release of radon, (2) to prevent the intrusion of plant roots and burrowing animals into the tailings, and (3) to limit surface erosion. The liner placed under a tailings pile prevents the migration of radionuclides and hazardous chemicals to groundwater. Pacific Northwest Laboratory is developing and evaluating cover and liner systems that meet these objectives and conform to federal standards. The cover and liner technology discussed in this paper involves: (1) single and multilayer earthen cover systems, (2) asphalt emulsion radon barrier systems, (3) biobarrier systems, (4) revegetation and rock covers, and (5) asphalt, clay, and synthetic liner systems. These systems have been tested at the Grand Junction, Colorado, tailings pile, where they have been shown to effectively reduce radon releases and radionuclide and chemical migration

Tendency of spherically imploding plasma liners formed by merging plasma jets to evolve toward spherical symmetry

International Nuclear Information System (INIS)

Cassibry, J. T.; Stanic, M.; Hsu, S. C.; Witherspoon, F. D.; Abarzhi, S. I.

2012-01-01

We have performed three-dimensional (3D) simulations using smoothed particle hydrodynamics (SPH) in order to study the effects of discrete plasma jets on the processes of plasma liner formation, implosion on vacuum, and expansion. It was found that the pressure histories of the inner portion of the liner from 3D SPH simulations with a uniform liner and with 30 discrete plasma jets were qualitatively and quantitatively similar from peak compression through the complete stagnation of the liner. The 3D simulations with a uniform liner were first benchmarked against results from one-dimensional radiation-hydrodynamic simulations [T. J. Awe et al., Phys. Plasmas 18, 072705 (2011)]. Two-dimensional plots of the pressure field show that the discrete jet SPH case evolves towards a profile that is almost indistinguishable from the SPH case with a uniform liner, thus indicating that non-uniformities due to discrete jets are smeared out by late stages of the implosion. The processes of plasma liner formation and implosion on vacuum were shown to be robust against Rayleigh-Taylor instability growth. Finally, interparticle mixing for a liner imploding on vacuum was investigated. The mixing rate was found to be very small until after the peak compression for the 30 jet simulations.

SUN HUB – ENERGY HUB FOR OUTDOOR TABLES

DEFF Research Database (Denmark)

Poulsen, Peter Behrensdorff; Benatto, Gisele Alves dos Reis; Riedel, Nicholas

2017-01-01

connections, providing opportunity to stream music via Bluetooth and play it from a handheld device to the table and lastly to provide LED lighting on the table during the dark hours. 3 prototypes of the system was built and tested at the Roskilde Festival 2017. Electrical logger units were built into the 3...... on festivals where people camps for several days it can be hard to have your portable units charged. In this this work we report a solar powered hub, as an add-on to a table in the urban environment for charging mobile phones and tablets and other handheld devices through USBs, charging laptops through AC...

Multiple Hub Network Choice in the Liberalized European Market

Science.gov (United States)

Berechman, Joseph; deWit, Jaap

1997-01-01

A key question that so far has received relatively little attention in the germane literature is that of the changes at various airports as a result of the EU liberalization policies. That is, presently, most major European airports still benefit from the so-called home-carrier phenomenon where the country's publicly or semi-publicly owned carrier uses the country's main airport as its gateway hub and, consequently, the home-carrier is also the principal user of this airport (in terms of proportion of total aircraft movements, number of passengers transported, connections, slots ownership, etc.). The country's main airport has substantially benefited from these monopoly conditions of airline captivity, strongly determined by the bilateral system of international air transport regulation. Therefore, European major airports were used to operate in essentially different markets, compared to the increasingly competitive markets of their home based carriers. This partly explains relative stability of transport volumes and financial results of European major airports compared to the relatively volatile financial results of most European national airlines. However, the liberalization of European aviation is likely to change this situation. Market access is open now to all community carriers, i.e. carriers with majority ownership and effective control in the hands of EU citizens. Ticket prices are free, governments can only intervene in case of dumping or excessive pricing. A community airline can choose its seat in any of the 15 member states. Licensing procedures are harmonized between member states. In the last few months community carriers have had unrestricted route access within the EU. Most probably this development will be extended to countries inside and outside Europe. Last year the European Commission got the mandate to start negotiations with 10 other European countries. In the meantime the EC has also started negotiations with the USA on so-called soft rights

Helium High Pressure Tanks at EADS Space Transportation New Technology with Thermoplastic Liner

National Research Council Canada - National Science Library

Benedic, Fabien; Leard, Jean-Philippe; Lefloch, Christian

2005-01-01

.... In order to achieve the new target prices, a new disruptive technology has been performing for several years in using a thermoplastic liner instead the usual expensive concept of metallic forged liner...

Plasma Liner Research for MTF at NASA Marshall Space Flight Center

Science.gov (United States)

Thio, Y. C. F.; Eskridge, R.; Lee, M.; Martin, A.; Smith, J.; Cassibry, J. T.; Wu, S. T.; Kirkpatrick, R. C.; Knapp, C. E.; Turchi, P. J.;

Friction Stir Welding of GR-Cop 84 for Combustion Chamber Liners

Science.gov (United States)

Russell, Carolyn K.; Carter, Robert; Ellis, David L.; Goudy, Richard

2004-01-01

GRCop-84 is a copper-chromium-niobium alloy developed by the Glenn Research Center for liquid rocket engine combustion chamber liners. GRCop-84 exhibits superior properties over conventional copper-base alloys in a liquid hydrogen-oxygen operating environment. The Next Generation Launch Technology program has funded a program to demonstrate scale-up production capabilities of GR-Cop 84 to levels suitable for main combustion chamber production for the prototype rocket engine. This paper describes a novel method of manufacturing the main combustion chamber liner. The process consists of several steps: extrude the GR-Cop 84 powder into billets, roll the billets into plates, bump form the plates into cylinder halves and friction stir weld the halves into a cylinder. The cylinder is then metal spun formed to near net liner dimensions followed by finish machining to the final configuration. This paper describes the friction stir weld process development including tooling and non-destructive inspection techniques, culminating in the successful production of a liner preform completed through spin forming.

Predicting highly-connected hubs in protein interaction networks by QSAR and biological data descriptors

Science.gov (United States)

Hsing, Michael; Byler, Kendall; Cherkasov, Artem

2009-01-01

Hub proteins (those engaged in most physical interactions in a protein interaction network (PIN) have recently gained much research interest due to their essential role in mediating cellular processes and their potential therapeutic value. It is straightforward to identify hubs if the underlying PIN is experimentally determined; however, theoretical hub prediction remains a very challenging task, as physicochemical properties that differentiate hubs from less connected proteins remain mostly uncharacterized. To adequately distinguish hubs from non-hub proteins we have utilized over 1300 protein descriptors, some of which represent QSAR (quantitative structure-activity relationship) parameters, and some reflect sequence-derived characteristics of proteins including domain composition and functional annotations. Those protein descriptors, together with available protein interaction data have been processed by a machine learning method (boosting trees) and resulted in the development of hub classifiers that are capable of predicting highly interacting proteins for four model organisms: Escherichia coli, Saccharomyces cerevisiae, Drosophila melanogaster and Homo sapiens. More importantly, through the analyses of the most relevant protein descriptors, we are able to demonstrate that hub proteins not only share certain common physicochemical and structural characteristics that make them different from non-hub counterparts, but they also exhibit species-specific characteristics that should be taken into account when analyzing different PINs. The developed prediction models can be used for determining highly interacting proteins in the four studied species to assist future proteomics experiments and PIN analyses. Availability The source code and executable program of the hub classifier are available for download at: http://www.cnbi2.ca/hub-analysis/ PMID:20198194

The basic design of the Krupp heat-insulating system with hot liner for PCPVs of HTRs

International Nuclear Information System (INIS)

Spandick, W.

1979-01-01

Presented is the design of a heat-insulating system incorporating a so called ''hot'' liner for use with high temperature reactors. The liner is in direct contact with the coolant, has a thickness of between 10 and 15 mm and is arc welded to anchors embedded in the concrete. Thermal cyclic tests were performed and incipient cracks were detected after about 5000 cycles; the liner is to be designed for between 800 and 1400 cycles. The liner design allows for internal inspection and, if necessary, repair at all times. Tests have shown the advantages of the design provided liner temperatures do not rise above 300 0 C

Microfluidic hubs, systems, and methods for interface fluidic modules

Science.gov (United States)

Bartsch, Michael S; Claudnic, Mark R; Kim, Hanyoup; Patel, Kamlesh D; Renzi, Ronald F; Van De Vreugde, James L

2015-01-27

Embodiments of microfluidic hubs and systems are described that may be used to connect fluidic modules. A space between surfaces may be set by fixtures described herein. In some examples a fixture may set substrate-to-substrate spacing based on a distance between registration surfaces on which the respective substrates rest. Fluidic interfaces are described, including examples where fluid conduits (e.g. capillaries) extend into the fixture to the space between surfaces. Droplets of fluid may be introduced to and/or removed from microfluidic hubs described herein, and fluid actuators may be used to move droplets within the space between surfaces. Continuous flow modules may be integrated with the hubs in some examples.

Design report on the SSCL prototype 80 K Synchrotron Radiation Liner System

International Nuclear Information System (INIS)

Shu, Q.S.; Barts, T.; Chou, W.

1993-09-01

This report documents the effort to develop a viable design for an SSC prototype 80 K Synchrotron Radiation Liner System. This liner is designed to be tested in the Superconducting Super Collider Accelerator Systems String Test (ASST) facility. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum environment. Secondly, the liner is aimed at improving the Collider cryogenic thermal efficiency which would allow a potential luminosity upgrade. The SSC Collider is the first proton superconducting accelerator designed to operate at an energy of 20 TeV (each beam) and a beam current of 72 mA. The Collider will produce a synchrotron power of 0.14 W/m and a total of 18 kW into 4.2 K for the two rings. This radiated power may trigger a serious impact of photodesorbed gases on the operational availability of the Collider. The interaction between beam particle and photodesorbed gases may greatly reduce the beam lifetime and the scattered beam power may lead to quenching of the superconducting magnets. Collider availability may be unacceptable if this concern is not properly addressed. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum. Secondly, the liner is aimed improving the Collider's cryogenic thermal efficiency which would allow a potential luminosity upgrade. The ultimate goal is to require no more than one machine warm up per year for vacuum maintenance during operation of the SSC Collider

Design report on the SSCL prototype 80 K Synchrotron Radiation Liner System

Energy Technology Data Exchange (ETDEWEB)

Shu, Q.S.; Barts, T.; Chou, W. [and others

1993-09-01

This report documents the effort to develop a viable design for an SSC prototype 80 K Synchrotron Radiation Liner System. This liner is designed to be tested in the Superconducting Super Collider Accelerator Systems String Test (ASST) facility. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum environment. Secondly, the liner is aimed at improving the Collider cryogenic thermal efficiency which would allow a potential luminosity upgrade. The SSC Collider is the first proton superconducting accelerator designed to operate at an energy of 20 TeV (each beam) and a beam current of 72 mA. The Collider will produce a synchrotron power of 0.14 W/m and a total of 18 kW into 4.2 K for the two rings. This radiated power may trigger a serious impact of photodesorbed gases on the operational availability of the Collider. The interaction between beam particle and photodesorbed gases may greatly reduce the beam lifetime and the scattered beam power may lead to quenching of the superconducting magnets. Collider availability may be unacceptable if this concern is not properly addressed. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum. Secondly, the liner is aimed improving the Collider`s cryogenic thermal efficiency which would allow a potential luminosity upgrade. The ultimate goal is to require no more than one machine warm up per year for vacuum maintenance during operation of the SSC Collider.

North West Surrey's locality hubs - delivering integrated care

OpenAIRE

Compton, Lisa; Wilkinson, Peter; Lawn, Liz

2017-01-01

Introduction: North West Surrey CCG (NWSCCG) is establishing Locality Hubs – physical buildings offering a fully integrated GP-led, multi-disciplinary ‘one-stop-shop’ services in the community for a defined cohort of frail elderly patients with multiple core morbidities. Hubs will ultimately deliver proactive and reactive care, available 24 hours a day, 365 days a year.The key drivers are;Ageing population, people living longer & more people living with chronic conditionsCost & demand...

A review of bias flow liners for acoustic damping in gas turbine combustors

Science.gov (United States)

Lahiri, C.; Bake, F.

2017-07-01

The optimized design of bias flow liner is a key element for the development of low emission combustion systems in modern gas turbines and aero-engines. The research of bias flow liners has a fairly long history concerning both the parameter dependencies as well as the methods to model the acoustic behaviour of bias flow liners under the variety of different bias and grazing flow conditions. In order to establish an overview over the state of the art, this paper provides a comprehensive review about the published research on bias flow liners and modelling approaches with an extensive study of the most relevant parameters determining the acoustic behaviour of these liners. The paper starts with a historical description of available investigations aiming on the characterization of the bias flow absorption principle. This chronological compendium is extended by the recent and ongoing developments in this field. In a next step the fundamental acoustic property of bias flow liner in terms of the wall impedance is introduced and the different derivations and formulations of this impedance yielding the different published model descriptions are explained and compared. Finally, a parametric study reveals the most relevant parameters for the acoustic damping behaviour of bias flow liners and how this is reflected by the various model representations. Although the general trend of the investigated acoustic behaviour is captured by the different models fairly well for a certain range of parameters, in the transition region between the resonance dominated and the purely bias flow related regime all models lack the correct damping prediction. This seems to be connected to the proper implementation of the reactance as a function of bias flow Mach number.

In the zone - first rotary steerable liner-while-drilling system; Drilling technology

Energy Technology Data Exchange (ETDEWEB)

2010-07-01

Statoil recently successfully tested the world's first rotary steerable liner-while-drilling system from its Brage platform in the Norwegian sector of the North Sea. This innovative technology - with applications in new and mature fields - was jointly developed by Statoil and Baker Hughes Incorporated. The concept of a rotary steerable system that gives operators the ability to accurately drill and log three-dimensional well profiles with a liner attached directly to the drillstring is entirely new. The system is designed to withstand high circulation rates and high torque loads while providing liner connect and disconnect capabilities. (Author)

Green Shipping Practices of Shipping Firms

Directory of Open Access Journals (Sweden)

Young-Tae Chang

2017-05-01

Full Text Available The primary objective of this study is to provide an empirical research using structural equation modeling to identify the factors that motivate shipping firms to adopt green shipping practices (GSP. Furthermore, it also examines if adopting GSP can enhance the shipping firms’ environmental and productivity performance. The findings show that shipping firms are motivated to adopt GSP mostly by industrial norms set by institutionalized associations. They are also motivated by customers’ demand for environmental friendliness and their own strategy to make good image. Unlike our expectation, government regulations and international environmental laws are not significant in influencing shipping firms to adopt GSP. Moreover, adoption of green shipping practices can improve the environmental and productivity performance of the shipping firms.

Evaluation Of Liner Back-pressure Due To Concrete Pore Pressure At Elevated Temperatures

International Nuclear Information System (INIS)

James, R.J.; Rashid, Y.R.; Liu, A.S.; Gou, B.

2006-01-01

GE's latest evolution of the boiling water reactor, the ESBWR, has innovative passive design features that reduce the number and complexity of active systems, which in turn provide economic advantages while also increasing safety. These passive systems used for emergency cooling also mean that the primary containment system will experience elevated temperatures with longer durations than conventional plants in the event of design basis accidents. During a Loss of Coolant Accident (LOCA), the drywell in the primary containment structure for the ESBWR will be exposed to saturated steam conditions for up to 72 hours following the accident. A containment spray system may be activated that sprays the drywell area with water to condense the steam as part of the recovery operations. The liner back-pressure will build up gradually over the 72 hours as the concrete temperatures increase, and a sudden cool down could cause excessive differential pressure on the liner to develop. For this analysis, it is assumed that the containment spray is activated at the end of the 72-hour period. A back-pressure, acting between the liner and the concrete wall of the containment, can occur as a result of elevated temperatures in the concrete causing steam and saturated vapor pressures to develop from the free water remaining in the pores of the concrete. Additional pore pressure also develops under the elevated temperatures from the non-condensable gases trapped in the concrete pores during the concrete curing process. Any buildup of this pore pressure next to the liner, in excess of the drywell internal pressure, will act to push the liner away from the concrete with a potential for tearing at the liner anchorages. This paper describes the methods and analyses used to quantify this liner back-pressure so that appropriate measures are included in the design of the liner and anchorage system. A pore pressure model is developed that calculates the pressure distribution across the concrete

Evaluation of a stack: A concrete chimney with brick liner

International Nuclear Information System (INIS)

Joshi, J.R.; Amin, J.A.; Porthouse, R.A.

1995-01-01

A 200 ft. tall stack, consisting of a concrete chimney with an independent acid proof brick liner built in the 1950's, serving the Separations facility at the Savannah River Site (SRS), was evaluated for the performance category 3 (PC3) level of Natural Phenomena Hazards (NPH) effects. The inelastic energy absorption capacity of the concrete chimney was considered in the evaluation of the earthquake resistance, in particular, to compute the F μ factor. The calculated value of F μ exceeded 3.0, while the seismic demand for the PC3 level, using an F μ value of 1.5, was found to be less than the capacity of the concrete chimney. The capacity formulation of ACI 307 was modified to incorporate the effect of an after design opening on the tension side. There are considerable uncertainties in determining the earthquake resistance of the independent brick liner. The critical liner section, located at the bottom of the breeching opening, does not meet the current recommendations. A discussion is provided for the possible acceptable values for the ''Moment Reduction Factor'', R w or F μ for the liner. Comments are provided on the comparison of stack demands using response spectra (RS) versus time history (TH) analysis, with and without soil structure interaction (SSI) effects

Indications of marine bioinvasion from network theory. An analysis of the global cargo ship network

Science.gov (United States)

Kölzsch, A.; Blasius, B.

2011-12-01

The transport of huge amounts of small aquatic organisms in the ballast tanks and at the hull of large cargo ships leads to ever increasing rates of marine bioinvasion. In this study, we apply a network theoretic approach to examine the introduction of invasive species into new ports by global shipping. This is the first stage of the invasion process where it is still possible to intervene with regulating measures. We compile a selection of widely used and newly developed network properties and apply these to analyse the structure and spread characteristics of the directed and weighted global cargo ship network (GCSN). Our results reveal that the GCSN is highly efficient, shows small world characteristics and is positive assortative, indicating that quick spread of invasive organisms between ports is likely. The GCSN shows strong community structure and contains two large communities, the Atlantic and Pacific trading groups. Ports that appear as connector hubs and are of high centralities are the Suez and Panama Canal, Singapore and Shanghai. Furthermore, from robustness analyses and the network's percolation behaviour, we evaluate differences of onboard and in-port ballast water treatment, set them into context with previous studies and advise bioinvasion management strategies.

75 FR 1596 - Grant of Authority for Subzone Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock...

Science.gov (United States)

2010-01-12

... Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its...-purpose subzone at the aluminum foil liner stock manufacturing and distribution facilities of Reynolds... manufacturing and distribution of aluminum foil liner stock and aluminum foil at the facilities of Reynolds...

Evaluation of the structural integrity of LMFBR equipment cell liners: results of preliminary investigations

International Nuclear Information System (INIS)

McAfee, W.J.; Sartory, W.K.

1976-01-01

The behavior of a plane wall segment of a prototype liquid-metal-cooled fast breeder reactor (LMFBR) cell under conditions of a postulated massive sodium spill was studied. Sodium-concrete reaction calculations were performed assuming an initial flaw existed in the liner such that high-temperature sodium could penetrate to the concrete underneath. Based on existing sodium-concrete reaction rate data, bounding values were established for the maximum energy release per unit volume of concrete. The potential effect of this energy release on the deformation of the liner material was determined. The temperature buildup in the liner and the pressure differential across the flaw in the liner were also studied. The transient thermal and structural responses of the steel liner and backup concrete were analyzed in detail using the inelastic computer code ANSYS. The literature on the mechanical, physical, and general behavior properties of concrete at high temperature was reviewed. This review emphasized the structural behavior of concrete and did not cover the sodium-concrete reaction

Effect of long-time immersion of soft denture liners in water on viscoelastic properties.

Science.gov (United States)

Iwasaki, Naohiko; Yamaki, Chisato; Takahashi, Hidekazu; Oki, Meiko; Suzuki, Tetsuya

2017-09-26

Aim of this study was to investigate the effect of long-time immersion of soft denture liners in 37°C water on viscoelastic properties. Six silicone-based and two acrylic resin-based soft denture liners were selected. Cylindrical specimens were stored in distilled water at 37°C for 6 months. Viscoelastic properties, which were instantaneous and delayed elastic displacements, viscous flow, and residual displacement, were determined using a creep meter, and analyzed with 2-way analysis of variance and Tukey's comparison (α=0.05). Viscoelastic properties and their time-dependent changes were varied among materials examined. The observed viscoelastic properties of three from six silicone-based liners did not significantly change after 6-month immersion, but those of two acrylic resin-based liners significantly changed with the increase of immersion time. However, the sum of initial instantaneous elastic displacement and delayed elastic displacement of two acrylic resin-based liners during 6-month immersion changed less than 10%, which might indicate clinically sufficient elastic performance.

Candida albicans biofilms and MMA surface treatment influence the adhesion of soft denture liners to PMMA resin

Directory of Open Access Journals (Sweden)

Martinna de Mendonça e Bertolini

2014-01-01

Full Text Available The effect of Candida albicans biofilms and methyl methacrylate (MMA pretreatment on the bond strength between soft denture liners and polymethyl methacrylate (PMMA resin was analyzed. Specimens were prepared and randomly divided with respect to PMMA pretreatment, soft liner type (silicone-based or PMMA-based, and presence or absence of a C. albicans biofilm. Samples were composed of a soft denture liner bonded between two PMMA bars. Specimens (n = 10 were incubated to produce a C. albicans biofilm or stored in sterile PBS for 12 days. The tensile bond strength test was performed and failure type was determined using a stereomicroscope. Surface roughness (SR and scanning electron microscopy (SEM analysis were performed on denture liners (n = 8. Highest bond strength was observed in samples containing a silicone-based soft liner and stored in PBS, regardless of pretreatment (p < 0.01. Silicone-based specimens mostly underwent adhesive failures, while samples containing PMMA-based liners predominantly underwent cohesive failures. The silicone-based specimens SR decreased after 12 days of biofilm accumulation or PBS storage, while the SR of PMMA-based soft liners increased (p < 0.01. The PMMA-based soft liners surfaces presented sharp valleys and depressions, while silicone-based specimens surfaces exhibited more gentle features. In vitro exposure to C. albicans biofilms reduced the adhesion of denture liners to PMMA resin, and MMA pretreatment is recommended during relining procedures.

DigitalHub: A Repository Focused on the Future.

Science.gov (United States)

Ilik, Violeta; Hebal, Piotr; Olson, Anton; Wishnetsky, Susan; Pastva, Joelen; Kubilius, Ramune; Shank, Jonathan; Gutzman, Karen; Chung, Margarita; Holmes, Kristi

2018-01-01

The DigitalHub scholarly repository was developed and launched at the Galter Health Sciences Library for the Feinberg School of Medicine and the greater Northwestern Medicine community. The repository was designed to allow scholars the ability to create, share, and preserve a range of citable digital outputs. This article traces the evolution of DigitalHub's development and engagement activities, highlighting project challenges, innovations, success stories, and the team-based approach that was employed to successfully achieve project goals.

Incremental Optimization of Hub and Spoke Network for the Spokes’ Numbers and Flow

Directory of Open Access Journals (Sweden)

Yanfeng Wang

2015-01-01

Full Text Available Hub and spoke network problem is solved as part of a strategic decision making process which may have a profound effect on the future of enterprises. In view of the existing network structure, as time goes on, the number of spokes and the flow change because of different sources of uncertainty. Hence, the incremental optimization of hub and spoke network problem is considered in this paper, and the policy makers should adopt a series of strategies to cope with the change, such as setting up new hubs, adjusting the capacity level of original hubs, or closing some original hubs. The objective is to minimize the total cost, which includes the setup costs for the new hubs, the closure costs, and the adjustment costs for the original hubs as well as the flow routing costs. Two mixed-integer linear programming formulations are proposed and analyzed for this problem. China Deppon Logistics as an example is performed to present computational analysis, and we analyze the changes in the solutions driven by the number of spokes and the flow. The tests also allow an analysis to consider the effect of variation in parameters on network.

Impact of landfill liner time-temperature history on the service life of HDPE geomembranes.

Science.gov (United States)

Rowe, R Kerry; Islam, M Z

2009-10-01

The observed temperatures in different landfills are used to establish a number of idealized time-temperature histories for geomembrane liners in municipal solid waste (MSW) landfills. These are then used for estimating the service life of different HDPE geomembranes. The predicted antioxidant depletion times (Stage I) are between 7 and 750 years with the large variation depending on the specific HDPE geomembrane product, exposure conditions, and most importantly, the magnitude and duration of the peak liner temperature. The higher end of the range corresponds to data from geomembranes aged in simulated landfill liner tests and a maximum liner temperature of 37 degrees C. The lower end of the range corresponds to a testing condition where geomembranes were immersed in a synthetic leachate and a maximum liner temperature of 60 degrees C. The total service life of the geomembranes was estimated to be between 20 and 3300 years depending on the time-temperature history examined. The range illustrates the important role that time-temperature history could play in terms of geomembrane service life. The need for long-term monitoring of landfill liner temperature and for geomembrane ageing studies that will provide improved data for assessing the likely long-term performance of geomembranes in MSW landfills are highlighted.

Mass ablation and magnetic flux losses through a magnetized plasma-liner wall interface

Science.gov (United States)

García-Rubio, F.; Sanz, J.

2017-07-01

The understanding of energy and magnetic flux losses in a magnetized plasma medium confined by a cold wall is of great interest in the success of magnetized liner inertial fusion (MagLIF). In a MagLIF scheme, the fuel is magnetized and subsonically compressed by a cylindrical liner. Magnetic flux conservation is degraded by the presence of gradient-driven transport processes such as thermoelectric effects (Nernst) and magnetic field diffusion. In previous publications [Velikovich et al., Phys. Plasmas 22, 042702 (2015)], the evolution of a hot magnetized plasma in contact with a cold solid wall (liner) was studied using the classical collisional Braginskii's plasma transport equations in one dimension. The Nernst term degraded the magnetic flux conservation, while both thermal energy and magnetic flux losses were reduced with the electron Hall parameter ωeτe with a power-law asymptotic scaling (ωeτe)-1/2. In the analysis made in the present paper, we consider a similar situation, but with the liner being treated differently. Instead of a cold solid wall acting as a heat sink, we model the liner as a cold dense plasma with low thermal conduction (that could represent the cryogenic fuel layer added on the inner surface of the liner in a high-gain MagLIF configuration). Mass ablation comes into play, which adds notably differences to the previous analysis. The direction of the plasma motion is inverted, but the Nernst term still convects the magnetic field towards the liner. Magnetization suppresses the Nernst velocity and improves the magnetic flux conservation. Thermal energy in the hot plasma is lost in heating the ablated material. When the electron Hall parameter is large, mass ablation scales as (ωeτe)-3/10, while both the energy and magnetic flux losses are reduced with a power-law asymptotic scaling (ωeτe)-7/10.

Plasma-Jet-Driven Magneto-Inertial Fusion (PJMIF): Physics and Design for a Plasma Liner Formation Experiment

Science.gov (United States)

Hsu, Scott; Cassibry, Jason; Witherspoon, F. Douglas

2014-10-01

Spherically imploding plasma liners are a potential standoff compression driver for magneto-inertial fusion, which is a hybrid of and operates in an intermediate density between those of magnetic and inertial fusion. We propose to use an array of merging supersonic plasma jets to form a spherically imploding plasma liner. The jets are to be formed by pulsed coaxial guns with contoured electrodes that are placed sufficiently far from the location of target compression such that no hardware is repetitively destroyed. As such, the repetition rate can be higher (e.g., 1 Hz) and ultimately the power-plant economics can be more attractive than most other MIF approaches. During the R&D phase, a high experimental shot rate at reasonably low cost (e.g., gun plasma-liner-formation experiment, which will provide experimental data on: (i) scaling of peak liner ram pressure versus initial jet parameters, (ii) liner non-uniformity characterization and control, and (iii) control of liner profiles for eventual gain optimization.

Experimental Study of Magnetic Field Production and Dielectric Breakdown of Auto-Magnetizing Liners

Science.gov (United States)

Shipley, Gabriel; Awe, Thomas; Hutchinson, Trevor; Hutsel, Brian; Slutz, Stephen; Lamppa, Derek

2017-10-01

AutoMag liners premagnetize the fuel in MagLIF targets and provide enhanced x-ray diagnostic access and increased current delivery without requiring external field coils. AutoMag liners are composite liners made with discrete metallic helical conduction paths separated by insulating material. First, a low dI/dt ``foot'' current pulse (1 MA in 100 ns) premagnetizes the fuel. Next, a higher dI/dt pulse with larger induced electric field initiates breakdown on the composite liner's; surface, switching the current from helical to axial to implode the liner. Experiments on MYKONOS have tested the premagnetization and breakdown phases of AutoMag and demonstrate axial magnetic fields above 90 Tesla for a 550 kA peak current pulse. Electric fields of 17 MV/m have been generated before breakdown. AutoMag may enhance MagLIF performance by increasing the premagnetization strength significantly above 30 T, thus reducing thermal-conduction losses and mitigating anomalous diffusion of magnetic field out of hotter fuel regions, by, for example, the Nernst thermoelectric effect. This project was funded in part by Sandia's Laboratory Directed Research and Development Program (Projects No. 200169 and 195306).

Thermal asymmetry model of single slope single basin solar still with sponge liner

Directory of Open Access Journals (Sweden)

Shanmugan Sengottain

2014-01-01

Full Text Available An attempt has been made to propose a thermal asymmetry model for single slope basin type solar still with sponge liner of different thickness (3cm, 5cm, and 10cm in the basin. Two different color sponge liners have been used i.e., yellow and black. In the proposed design, a suitable dripping arrangement has been designed and used to pour water drop by drop over the sponge liner instead of sponge liner in stagnant saline water in the basin. The special arrangement overcomes the dryness of the sponge during peak sunny hours. The performance of the system with black color sponge of 3cm thickness shows better result with an output of 5.3 kg/m2 day and the proposed model have used to find the thermal asymmetries during the working hours of the still.

Sci-Hub: What Librarians Should Know and Do about Article Piracy.

Science.gov (United States)

Hoy, Matthew B

2017-01-01

The high cost of journal articles has driven many researchers to turn to a new way of getting access: "pirate" article sites. Sci-Hub, the largest and best known of these sites, currently offers instant access to more than 58 million journal articles. Users attracted by the ease of use and breadth of the collection may not realize that these articles are often obtained using stolen credentials and downloading them may be illegal. This article will briefly describe Sci-Hub and how it works, the legal and ethical issues it raises, and the problems it may cause for librarians. Librarians should be aware of Sci-Hub and the ways it may change their patrons' expectations. They should also understand the risks Sci-Hub can pose to their patrons and their institutions.

Zoning Districts - Volusia County HUB Zones

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — Historically Underutilized Business (HUB) Zones in Volusia County. Go to http://www.sba.gov/hubzone or contact the Department of Economic Development (386) 248-8048...

The effect of release liner materials on adhesive contaminants, paper recycling and recycled paper properties

Science.gov (United States)

Richard Venditti; Richard Gilbert; Andy Zhang; Said Abubakr

2000-01-01

Release liner waste material is found in post-consumer waste streams and is also a significant component of the preconsumer waste stream generated in the manufacturing of adhesive products. To date, very little has been reported pertaining to the behavior of release liner in paper recycling. In this study, the effect of the release liner material on the behavior of...

Liner failure around a tunnel or a storage cell in Callovo-Oxfordian clay

International Nuclear Information System (INIS)

Damjanac, Branko; Radakovic-Guzina, Zorica; Billaux, Daniel; Poutrel, A.

2010-01-01

Document available in extended abstract form only. In the framework of the feasibility studies for the storage of radioactive waste in a deep geological layer, the post-failure behaviour of the concrete liner of the galleries and storage cells may have a direct effect on long term safety. In fact, the failure of the liner will result in new loads on the canisters placed inside the works, and in the de-stressing of the Callovo-Oxfordian clays, which may lead to a change in the Excavation Damage Zone. These phenomenons are studied via numerical modelling, using properties derived from ANDRA's underground laboratory (CMHM) project. Two types of gallery geometries are analyzed: one with a thinner concrete liner and filled interior (the standard gallery); and another with a thick concrete liner filled with concrete canisters (the MAVL disposal cell). The Standard Gallery is filled with a Cam-Clay material after 100 years of creep, while the MAVL disposal cell is filled with 16 concrete canisters immediately after installation of the concrete liner. Progressive failure of the concrete liner due to time-dependent deformation of the surrounding rock (Callovo-Oxfordian clay) over a long period of time is analyzed. The analyses are carried out in two steps. In the initial simulations, the concrete liner is represented as a continuum strain-softening Mohr-Coulomb material. The locations of stress-induced fractures in the concrete are determined from this continuum model. The stress-induced fractures are then specified as pre-defined discontinuities in the concrete liner in subsequent dis-continuum simulations. In a dis-continuum model, the large deformations and movements of the concrete blocks as the liner disintegrates can be simulated without numerical problems. The Callovo-Oxfordian clay is represented as an elastic-plastic-viscous material using the Lemaitre constitutive relation. The majority of the simulations are carried out over 5,000 years of creep time, with a

Automatic measuring system of zirconium thickness for zirconium liner cladding tubes

International Nuclear Information System (INIS)

Matsui, K.; Yamaguchi, H.; Hiroshima, T.; Sakamoto, T.; Murayama, R.

1985-01-01

An automatic system of pure zirconium liner thickness for zirconium-zircaloy cladding tubes has been successfully developed. The system consists of three parts. (1) An ultrasonic thickness measuring method for mother tubes before cold rolling. (2) An electromagnetic thickness measuring method for the manufactured tubes. (3) An image processing method for the cross sectional view of the manufactured cut tube samples. In Japanese nuclear industry, zirconium-zircaloy cladding tubes have been tested in order to realize load following operation in the atomic power plant. In order to provide for the practical use in the near future, Sumitomo Metal Industries, Ltd. has been studied and established the practical manufacturing process of the zirconium liner cladding tubes. The zirconium-liner cladding tube is a duplex tube comprising an inner layer of pure zirconium bonded to zircaloy metallurgically. The thickness of the pure zirconium is about 10 % of the total wall thickness. Several types of the automatic thickness measuring methods have been investigated instead of the usual microscopic viewing method in which the liner thickness is measured by the microscopic cross sectional view of the cut tube samples

Development of Lightweight, Compact, Structurally-Integrated Acoustic Liners for Broadband Low-Frequency Noise Mitigation

Science.gov (United States)

Chambers, Andrew T.

Airborne noise with a low dominant frequency content (scope of conventional acoustic noise mitigation techniques using liners, foams or claddings owing to mass and volume considerations. Its low evanescence contributes significantly to environmental noise pollution, and unwanted structural vibrations causing diminished efficiency, comfort, payload integrity and mission capabilities. An alternative approach using liner configurations with realistic mass and volume constraints having innovative 'folded' core geometries is investigated to ascertain its low-frequency noise absorption characteristics. In contrast to mass-driven approaches, the folded core approach relies on tailoring interactions between acoustic resonances to tune the liner's impedance to suit the dominant low-frequency content of the source. This allows to keep non-structural mass-addition to a minimum, while retaining an overall thickness comparable to conventional liners for these low-frequency liner designs. The relative acoustic performance of various candidate folded core designs is evaluated by means of a new composite metric termed the Low-Frequency Performance (LFP) factor, which is educed from the absorption coefficient spectrum obtained using Zwikker-Kosten Transmission Line (ZKTL) theory-based numerical studies. An LFP-based software tool is developed to determine optimal 3D cavity packing for a prescribed liner volume and target frequency range. ZKTL-based parametric studies on core dimensions and face sheet porosity are utilized for detailed design of test articles. Experimental verification of absorption coefficient spectra conducted using 3D printed test articles in a normal incidence acoustic impedance tube yield good correlation with simulations. More than 100 Hz of continuous bandwidth with an absorption coefficient greater than 0.6 is shown to be possible in the 300 to 400 Hz range with a 38.1-mm (1.5-inch) thick liner. Further, the influence of face sheet type, Mach number, and

City Hub : a cloud based IoT platform for Smart Cities

OpenAIRE

Lea, Rodger; Blackstock, Michael

2014-01-01

Cloud based Smart City hubs are an attractive approach to addressing some of the complex issues faced when deploying PaaS infrastructure for Smart Cities. In this paper we introduce the general notion of IoT hubs and then discusses our work to generalize our IoT hub as a Smart City PaaS. Two key issues are identified, support for hybrid public/private cloud and interoperability. We briefly describe our approach to these issues and discuss our experiences deploying two cloud-based Smart City h...

Idea Hubs as Nexus of Collective Creativity in Digital Innovation

DEFF Research Database (Denmark)

Ciriello, Raffaele; Richter, Alexander

2015-01-01

Digital innovation radically transforms the nature of corporate innovation practices, implying a growing need for deeper understanding its origins and outcomes. In this paper, we conceptualize the focal points of social networking in digital innovation as idea hubs. We focus our analysis...... on instances of idea hubs in two multinational European software companies, where we conducted a case study over a two-year period, and collected data in form of interviews, digital documents, and participant observations. In doing so, we identify a set of social networking practices in which idea hubs serve...... of digital artifacts individuals can choose from, offline interaction still plays a major role in facilitating digital innovation....

Development and application of a packer-type drilling-free liner hanger

Directory of Open Access Journals (Sweden)

Xin Tang

2014-12-01

Full Text Available In liner cementing, the upper cement plug and inner components of a common hanger needs to be drilled out after cementing, which will result in a poor cementing quality or even gas leakage at the flare opening. Therefore, a new packer-type drilling-free liner hanger has been developed, and a hydraulic setting-control packer, a flexible drilling-free seal box, and an auxiliary bearing back-off mechanism that go with the line hanger have been designed at the same time. Specific operation procedures include: (1 run in the liner string to the designed depth, then fully circulate the drilling fluid, finally drop the ball. When the tripping ball gets into the seat, the pressure will go up to cut off the hanging control pin and set the hanger; (2 continue to hold the pressure and cut off the ball seat pin to form circulation; (3 trip in the drill pipe to exert pressure on the hanger, back off to release the hanger from the running tool; (4 lower the drill pipe plug upon the completion of cement injection, cut off the releasing control pin of hollow casing plug, and run down further to bump with the bumping assembly; (5 remove the cementing head and connect the kelly driver, hold pressure again, then slowly pull up the drill tools, exert hydraulic pressure on the setting hydraulic cylinder of the packer assembly to cut off the setting control pin and set the packer; and (6 pull up the tools to the flare opening and wash out excessive cement slurry by circulating to realize free drilling of the whole hole. The successful application of the liner hanger in 127 mm diameter liner in Well BQ203-H1 indicates that the packer-type liner hanger has such advantages as easy hanging and back-off, accurate bumping, simple setting, and sound sealing performance.

Connectome hubs at resting state in children and adolescents: Reproducibility and psychopathological correlation

Directory of Open Access Journals (Sweden)

João Ricardo Sato

2016-08-01

Full Text Available Functional brain hubs are key integrative regions in brain networks. Recently, brain hubs identified through resting-state fMRI have emerged as interesting targets to increase understanding of the relationships between large-scale functional networks and psychopathology. However, few studies have directly addressed the replicability and consistency of the hub regions identified and their association with symptoms. Here, we used the eigenvector centrality (EVC measure obtained from graph analysis of two large, independent population-based samples of children and adolescents (7–15 years old; total N = 652; 341 subjects for site 1 and 311 for site 2 to evaluate the replicability of hub identification. Subsequently, we tested the association between replicable hub regions and psychiatric symptoms. We identified a set of hubs consisting of the anterior medial prefrontal cortex and inferior parietal lobule/intraparietal sulcus (IPL/IPS. Moreover, lower EVC values in the right IPS were associated with psychiatric symptoms in both samples. Thus, low centrality of the IPS was a replicable sign of potential vulnerability to mental disorders in children. The identification of critical and replicable hubs in functional cortical networks in children and adolescents can foster understanding of the mechanisms underlying mental disorders.

Performance evaluation of a newly developed variable rate sprayer for nursery liner applications

Science.gov (United States)

An experimental variable-rate sprayer designed for liner applications was tested by comparing its spray deposit, coverage, and droplet density inside canopies of six nursery liner varieties with constant-rate applications. Spray samplers, including water sensitive papers (WSP) and nylon screens, wer...

Optimization of deformations and hoop stresses in TSV liners to boost interconnect reliability in electronic appliances

Science.gov (United States)

Juma, Mary Atieno; Zhang, Xuliang; He, Song Bai; Abusabah, Ahmed I. A.

2015-12-01

Recently, there has been a lot of research with electronic products because more and different functions are integrated into devices and the final product sizes have to be small to meet the market demand. A lot of research has been done on the (TSVs) Through Silicon Vias. In this paper, through silicon via liners are investigated. The liners: silicon dioxide, polystyrene and polypropylene carbonate are exposed to pressure on their inner surfaces and this yielded hoop stresses within their thickness. Deflections too occurred and this is a proof that deformation really took place. In one of our papers, hoop stresses for the same materials were investigated. The values were a little higher but different for each material used. In this paper, we use global cylindrical, partial cylinder model with different theta in Analysis system 14 to model the through silicon via liners. The values are lower meaning the reliability of the liners have been optimized and boosted. However, silicon dioxide liner had the lowest hoop stress around its circumference and lowest deflection value meaning that it's still one of the most reliable materials in the manufacture of through silicon via liners in the industry; but overdependence can be avoided if the other liners are used too.

Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability

Science.gov (United States)

Skoch, Gary J.

2004-01-01

Results from a series of experiments to investigate whether centrifugal compressor stability could be improved by injecting air through the diffuser hub surface are reported. The research was conducted in a 4:1 pressure ratio centrifugal compressor configured with a vane-island diffuser. Injector nozzles were located just upstream of the leading edge of the diffuser vanes. Nozzle orientations were set to produce injected streams angled at 8, 0 and +8 degrees relative to the vane mean camber line. Several injection flow rates were tested using both an external air supply and recirculation from the diffuser exit. Compressor flow range did not improve at any injection flow rate that was tested. Compressor flow range did improve slightly at zero injection due to the flow resistance created by injector openings on the hub surface. Leading edge loading and semi-vaneless space diffusion showed trends similar to those reported earlier from shroud surface experiments that did improve compressor flow range. Opposite trends are seen for hub injection cases where compressor flow range decreased. The hub injection data further explain the range improvement provided by shroud-side injection and suggest that different hub-side techniques may produce range improvement in centrifugal compressors.

Image flows and one-liner graphical image representation.

Science.gov (United States)

Makhervaks, Vadim; Barequet, Gill; Bruckstein, Alfred

2002-10-01

This paper introduces a novel graphical image representation consisting of a single curve-the one-liner. The first step of the algorithm involves the detection and ranking of image edges. A new edge exploration technique is used to perform both tasks simultaneously. This process is based on image flows. It uses a gradient vector field and a new operator to explore image edges. Estimation of the derivatives of the image is performed by using local Taylor expansions in conjunction with a weighted least-squares method. This process finds all the possible image edges without any pruning, and collects information that allows the edges found to be prioritized. This enables the most important edges to be selected to form a skeleton of the representation sought. The next step connects the selected edges into one continuous curve-the one-liner. It orders the selected edges and determines the curves connecting them. These two problems are solved separately. Since the abstract graph setting of the first problem is NP-complete, we reduce it to a variant of the traveling salesman problem and compute an approximate solution to it. We solve the second problem by using Dijkstra's shortest-path algorithm. The full software implementation for the entire one-liner determination process is available.

A Physics Exploratory Experiment on Plasma Liner Formation

Science.gov (United States)

Thio, Y. C. Francis; Knapp, Charles E.; Kirkpatrick, Ronald C.; Siemon, Richard E.; Turchi, Peter

2002-01-01

Momentum flux for imploding a target plasma in magnetized target fusion (MTF) may be delivered by an array of plasma guns launching plasma jets that would merge to form an imploding plasma shell (liner). In this paper, we examine what would be a worthwhile experiment to do in order to explore the dynamics of merging plasma jets to form a plasma liner as a first step in establishing an experimental database for plasma-jets driven magnetized target fusion (PJETS-MTF). Using past experience in fusion energy research as a model, we envisage a four-phase program to advance the art of PJETS-MTF to fusion breakeven Q is approximately 1). The experiment (PLX (Plasma Liner Physics Exploratory Experiment)) described in this paper serves as Phase I of this four-phase program. The logic underlying the selection of the experimental parameters is presented. The experiment consists of using twelve plasma guns arranged in a circle, launching plasma jets towards the center of a vacuum chamber. The velocity of the plasma jets chosen is 200 km/s, and each jet is to carry a mass of 0.2 mg - 0.4 mg. A candidate plasma accelerator for launching these jets consists of a coaxial plasma gun of the Marshall type.

Performance of a Liner-on-Target Injector for Staged Z-Pinch Experiments

Science.gov (United States)

Conti, F.; Valenzuela, J. C.; Narkis, J.; Krasheninnikov, I.; Beg, F.; Wessel, F. J.; Ruskov, E.; Rahman, H. U.; McGee, E.

2016-10-01

We present the design and characterization of a compact liner-on-target injector, used in the Staged Z-pinch experiments conducted on the UNR-NTF Zebra Facility. Previous experiments and analysis indicate that high-Z gas liners produce a uniform and efficient implosion on a low-Z target plasma. The liner gas shell is produced by an annular solenoid valve and a converging-diverging nozzle designed to achieve a collimated, supersonic, Mach-5 flow. The on-axis target is produced by a coaxial plasma gun, where a high voltage pulse is applied to ionize neutral gas and accelerate the plasma by the J-> × B-> force. Measurements of the liner and target dynamics, resolved by interferometry in space and time, fast imaging, and collection of the emitted light, are presented. The results are compared to the predictions from Computational Fluid Dynamics and MHD simulations that model the injector. Optimization of the design parameters, for upcoming Staged Z-pinch experiments, will be discussed. Advanced Research Projects Agency - Energy, DE-AR0000569.

A Hub Matrix Theory and Applications to Wireless Communications

Directory of Open Access Journals (Sweden)

Kung HT

2007-01-01

Full Text Available This paper considers communications and network systems whose properties are characterized by the gaps of the leading eigenvalues of for a matrix . It is shown that a sufficient and necessary condition for a large eigen-gap is that is a "hub" matrix in the sense that it has dominant columns. Some applications of this hub theory in multiple-input and multiple-output (MIMO wireless systems are presented.

Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

International Nuclear Information System (INIS)

von Riesemann, W.A.; Parks, M.B.

1993-01-01

In the United States, concrete containment buildings for commercial nuclear power plants have steel liners that act as the intemal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented. This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions)

The Virtual Campus Hub Concept

DEFF Research Database (Denmark)

Badger, Merete; Prag, Sidsel-Marie Winther; Monaco, Lucio

of Technology in Sweden, Politecnico di Torino in Italy, and Eindhoven University of Technology in the Netherlands. The project is partially funded by the European Commission under the 7th Framework Programme (project no. RI-283746). This report describes the final concept of Virtual Campus Hub. It gives...

Fabrication techniques of metal liner used for pressure vessels made by composite material

International Nuclear Information System (INIS)

Takahashi, W.K.; Al-Qureshi, H.A.

1982-01-01

Different viable techniques for the manufacturing of metal liner used for pressure vessels are presented. The aim of these metal liner is to avoid the fluid leakage from the pressurized vessel and to serve as a mandreal to be wound by composite material. The studied techniques are described and the practical results are illustrated. Finally a comparative study of the manufacturing techniques is made in order to define the process that furnishes the metal liner with the best characteristics. The advantages offered by these type of pressure vessels when compared with the conventional metallic vessels, are also presented. (Author) [pt

Filament wound pressure vessels with load sharing liners for space shuttle orbiter applications

International Nuclear Information System (INIS)

Ecord, G.M.

1976-01-01

Early in the development of orbiter propulsion and environmental control subsystems it was recognized that use of overwrapped pressure vessels with load sharing liners may provide significant weight savings for high pressure gas containment. A program is described which was undertaken by Rockwell International to assess the utility for orbiter applications of titanium 6Al--4V and Inconel 718 liners overwrapped with Kevlar fibers. Also briefly described are programs administered by the NASA Lewis Research Center to evaluate cryoformed steel liners overwrapped with Kevlar fibers and to establish a method that can guarantee cyclic life of the vessels

Investigation of a Bio-Inspired Liner Concept

Science.gov (United States)

Koch, L. Danielle

2017-01-01

Four samples of natural reeds, Phragmites australis, were tested in the NASA Langley and Glenn Normal Incidence Impedance Tubes in order to experimentally determine the acoustic absorption coefficients as a function of frequency from 400 to 3000 Hz. Six samples that mimicked the geometry of the assemblies of natural reeds were also designed and additively manufactured from ASA thermoplastic and tested. Results indicate that structures can be manufactured of synthetic materials that mimic the geometry and the low frequency acoustic absorption of natural reeds. This accomplishment demonstrates that a new class of structures can now be considered for a wide range of industrial products that need thin, lightweight, broadband acoustic absorption effective at frequencies below 1000 Hz. Aircraft engine acoustic liners and aircraft cabin acoustic liners, in particular, are two aviation applications that might benefit from further development of this concept.

MyGeoHub: A Collaborative Geospatial Research and Education Platform

Science.gov (United States)

Kalyanam, R.; Zhao, L.; Biehl, L. L.; Song, C. X.; Merwade, V.; Villoria, N.

2017-12-01

Scientific research is increasingly collaborative and globally distributed; research groups now rely on web-based scientific tools and data management systems to simplify their day-to-day collaborative workflows. However, such tools often lack seamless interfaces, requiring researchers to contend with manual data transfers, annotation and sharing. MyGeoHub is a web platform that supports out-of-the-box, seamless workflows involving data ingestion, metadata extraction, analysis, sharing and publication. MyGeoHub is built on the HUBzero cyberinfrastructure platform and adds general-purpose software building blocks (GABBs), for geospatial data management, visualization and analysis. A data management building block iData, processes geospatial files, extracting metadata for keyword and map-based search while enabling quick previews. iData is pervasive, allowing access through a web interface, scientific tools on MyGeoHub or even mobile field devices via a data service API. GABBs includes a Python map library as well as map widgets that in a few lines of code, generate complete geospatial visualization web interfaces for scientific tools. GABBs also includes powerful tools that can be used with no programming effort. The GeoBuilder tool provides an intuitive wizard for importing multi-variable, geo-located time series data (typical of sensor readings, GPS trackers) to build visualizations supporting data filtering and plotting. MyGeoHub has been used in tutorials at scientific conferences and educational activities for K-12 students. MyGeoHub is also constantly evolving; the recent addition of Jupyter and R Shiny notebook environments enable reproducible, richly interactive geospatial analyses and applications ranging from simple pre-processing to published tools. MyGeoHub is not a monolithic geospatial science gateway, instead it supports diverse needs ranging from just a feature-rich data management system, to complex scientific tools and workflows.

Soft Power and Cultural Diplomacy: Emerging Education Hubs in Asia

Science.gov (United States)

Lee, Jack T.

2015-01-01

Several education hubs have emerged in Asia and the Middle East in recent years with a specific focus on cross-border higher education. Through considerable efforts in policy planning and generous funding, these hubs aim to transform a country or city into an eminent destination for education, research, and training. The inherent design of these…

Analysis of Sci-Hub downloads of computer science papers

Directory of Open Access Journals (Sweden)

Andročec Darko

2017-07-01

Full Text Available The scientific knowledge is disseminated by research papers. Most of the research literature is copyrighted by publishers and avail- able only through paywalls. Recently, some websites offer most of the recent content for free. One of them is the controversial website Sci-Hub that enables access to more than 47 million pirated research papers. In April 2016, Science Magazine published an article on Sci-Hub activity over the period of six months and publicly released the Sci-Hub’s server log data. The mentioned paper aggregates the view that relies on all downloads and for all fields of study, but these findings might be hiding interesting patterns within computer science. The mentioned Sci-Hub log data was used in this paper to analyse downloads of computer science papers based on DBLP’s list of computer science publications. The top downloads of computer science papers were analysed, together with the geographical location of Sci-Hub users, the most downloaded publishers, types of papers downloaded, and downloads of computer science papers per publication year. The results of this research can be used to improve legal access to the most relevant scientific repositories or journals for the computer science field.

Evaluation of inactive uranium mill tailings sites for liner requirements: Characterization and interaction of tailings, soil, and liner materials

International Nuclear Information System (INIS)

Relyea, J.F.; Martin, W.J.

1982-01-01

This paper summarizes the results of laboratory experiments using soils from Clive, Utah and tailings samples from three inactive uranium processing sites. The results are to be used to predict contaminant behavior for comparison with the regulatory criteria to decide whether a liner is needed. The interactions of leachates with soils and liner material were studied using both batch and column methods. It is determined that batch leaching tests are suitable for screening a large number of tailings samples for relative contaminant concentrations between samples but not for determining contaminant concentrations and release rates in tailings leachate. The results of column leaching tests on samples of tailings from inactive sites indicate that contaminant concentrations are highest in initial leachate from the columns and that concentrations decrease by an order of magnitude or more after one pore volume

Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples.

Directory of Open Access Journals (Sweden)

Cheng Liu

Full Text Available The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width.

The Aerodynamic Performance of an Over-the-Rotor Liner With Circumferential Grooves on a High Bypass Ratio Turbofan Rotor

Science.gov (United States)

Bozak, Richard F.; Hughes, Christopher E.; Buckley, James

2013-01-01

While liners have been utilized throughout turbofan ducts to attenuate fan noise, additional attenuation is obtainable by placing an acoustic liner over-the-rotor. Previous experiments have shown significant fan performance losses when acoustic liners are installed over-the-rotor. The fan blades induce an oscillating flow in the acoustic liners which results in a performance loss near the blade tip. An over-the-rotor liner was designed with circumferential grooves between the fan blade tips and the acoustic liner to reduce the oscillating flow in the acoustic liner. An experiment was conducted in the W-8 Single-Stage Axial Compressor Facility at NASA Glenn Research Center on a 1.5 pressure ratio fan to evaluate the impact of this over-the-rotor treatment design on fan aerodynamic performance. The addition of a circumferentially grooved over-the-rotor design between the fan blades and the acoustic liner reduced the performance loss, in terms of fan adiabatic efficiency, to less than 1 percent which is within the repeatability of this experiment.

Engineering and innovative erection concept for the containment liner for an EPR trademark

International Nuclear Information System (INIS)

Goehring, Rainer

2010-01-01

The determination of the optimal design of the containment liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. The construction costs of a Nuclear Power Plant are also impacted by the erection time of components. Therefore, it is necessary to optimize the erection times and consequently essentially to shorten. One possibility has been demonstrated by Babcock Noell GmbH with the erection concept of a containment liner. The liner is preassembled on the pre-assembly place in rings of up to 12 meter height, with the nominal diameter of 47 meter and a weight of approximately up to 200 tonnes. These rings, as well as the containment cup and the dome, are lifted with a heavy load crane into the reactor building. Several load cases for normal operation and accidental conditions as well as severe accidents have been analysed. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. This is the topic of the speech '' Computational Concept for the Containment Liner for EPR trademark '', given by Mr. Franz Nagelstutz, Abt. Planning, Babcock Noell GmbH und Mr. Nils Anders, Babcock Noell GmbH, Abt. Planning. With this concept, the construction activities on the inner containment wall are only five times disrupted by the welding and coating of the circumferential weld (approx. 25 calendar days). In comparison with the common known erection concept of welding of liner shells in situ, at least 20 weeks are saved on the schedule. An integrated concept from planning, manufacturing and erection of this large component has been implemented. It could be demonstrated that within the given time frame, with the required quality and within the required tolerances the containment liner for the Nuclear Power Plant can be delivered to the Client. (orig.)

On Uncertain Ice: The Future of Arctic Shipping and the Northwest Passage

Directory of Open Access Journals (Sweden)

Whitney Lackenbauer

2014-12-01

Full Text Available The Arctic sea-ice is in a state of rapid decline. Barriers to navigation that once doomed the likes of Sir John Franklin and closed the shortcut to the Orient now seem to be melting away. The prospect of shorter, transpolar transportation routes linking Asian and Western markets has inspired excitement and fear, and particularly the latter when it comes to Canadian sovereignty. This paper confirms recent studies suggesting that, in spite of the general trend towards reduced ice cover in the Arctic Basin, environmental variability, scarce infrastructure and other navigational aids, and uncertain economics make it unlikely that the Northwest Passage will emerge as a viable trans-shipping route in the foreseeable future. Instead, the region is likely to witness a steady increase in resource, resupply, and tourist destinational shipping. Accordingly, concerns that this increased activity will adversely affect Canadian sovereignty are misplaced. Rather than calling into question Canadian control, foreign vessels engaged in local activities are likely to reinforce Canada’s legal position by demonstrating an international acceptance of Canadian laws and regulations. Rather than worrying about the “sovereignty” ramifications of Arctic shipping, the Canadian government should focus its short – and medium – term energies on the practical requirements of developing and maintaining safe shipping routes. At the heart of this requirement is ensuring that such activity is beneficial to Inuit, whose traditional “highways” will double as transits routes for resource carriers and cruise liners. If developed with an eye to those most directly affected, Canada’s Arctic waters can become a well-managed route to an increasingly attractive region, making our Arctic a destination rather than mere space through which to pass.

Using hybrid latent class model for city-HUBs´users behaviour analysis

OpenAIRE

Di Ciommo, Floridea; Monzón de Cáceres, Andrés; Oña, Rocío de; Oña López, Juan de; Hernández del Olmo, Sara

2014-01-01

Data from an attitudinal survey and stated preference ranking experiment conducted in two urban European interchanges (i.e. City-HUBs) in Madrid (Spain) and Thessaloniki (Greece) show that the importance that City-HUBs users attach to the intermodal infrastructure varies strongly as a function of their perceptions of time spent in the interchange (i.e.intermodal transfer and waiting time). A principal components analysis allocates respondents (i.e. city-HUB users) to two classes with substant...

Hydrodynamic model experiments for stabilized liquid liners with annular piston drive

International Nuclear Information System (INIS)

Burton, R.L.; Turchi, P.J.; Jenkins, D.J.; Cooper, A.L.

1977-01-01

The achievement of megagauss-level magnetic fields by flux compression using controlled liquid liner implosions will be studied in the LINUS-O experiments. This paper reports on experimental studies of the rotating liquid liner at lower energy density, using a one-third scale model with water as the liner material. Radial implosion of the free inside surface of the liquid is achieved by axial displacement of an annular piston, driven by helium. Azimuthally symmetric, repetitive implosion-reexpansion cycles have been demonstrated, with area compressions of over a hundred. The apparatus has also been used to investigate other problems inherent in the annular piston geometry, including piston guidance, seals, z-dependence of the imploding free surface trajectory, and Rayleigh-Taylor instability of the free surface. Methods for r-z plane tailoring of the free surface to provide three-dimensional payload compression are considered

The BioHub Knowledge Base: Ontology and Repository for Sustainable Biosourcing.

Science.gov (United States)

Read, Warren J; Demetriou, George; Nenadic, Goran; Ruddock, Noel; Stevens, Robert; Winter, Jerry

2016-06-01

The motivation for the BioHub project is to create an Integrated Knowledge Management System (IKMS) that will enable chemists to source ingredients from bio-renewables, rather than from non-sustainable sources such as fossil oil and its derivatives. The BioHubKB is the data repository of the IKMS; it employs Semantic Web technologies, especially OWL, to host data about chemical transformations, bio-renewable feedstocks, co-product streams and their chemical components. Access to this knowledge base is provided to other modules within the IKMS through a set of RESTful web services, driven by SPARQL queries to a Sesame back-end. The BioHubKB re-uses several bio-ontologies and bespoke extensions, primarily for chemical feedstocks and products, to form its knowledge organisation schema. Parts of plants form feedstocks, while various processes generate co-product streams that contain certain chemicals. Both chemicals and transformations are associated with certain qualities, which the BioHubKB also attempts to capture. Of immediate commercial and industrial importance is to estimate the cost of particular sets of chemical transformations (leading to candidate surfactants) performed in sequence, and these costs too are captured. Data are sourced from companies' internal knowledge and document stores, and from the publicly available literature. Both text analytics and manual curation play their part in populating the ontology. We describe the prototype IKMS, the BioHubKB and the services that it supports for the IKMS. The BioHubKB can be found via http://biohub.cs.manchester.ac.uk/ontology/biohub-kb.owl .

Measurements of Magneto-Rayleigh-Taylor instability growth in solid liners on the 20 MA Z facility

International Nuclear Information System (INIS)

Bigman, Verle; Vesey, Roger Alan; Shores, Jonathon; Herrmann, Mark C.; Stamm, Robert; Killebrew, Korbie; Holt, Randy; Blue, Brent; Nakhleh, Charlie; McBride, Ryan D.; Leifeste, Gordon T.; Smith, Ian Craig; Stygar, William A.; Porter, John Larry Jr.; Cuneo, Michael Edward; Bennett, Guy R.; Schroen, Diana Grace; Sinars, Daniel Brian; Lopez, Mike R.; Slutz, Stephen A.; Atherton, Briggs W.; Tomlinson, Kurt; Edens, Aaron D.; Savage, Mark Edward; Peterson, Kyle J.

2010-01-01

The magneto-Rayleigh-Taylor (MRT) instability is the most important instability for determining whether a cylindrical liner can be compressed to its axis in a relatively intact form, a requirement for achieving the high pressures needed for inertial confinement fusion (ICF) and other high energy-density physics applications. While there are many published RT studies, there are a handful of well-characterized MRT experiments at time scales >1 (micro)s and none for 100 ns z-pinch implosions. Experiments used solid Al liners with outer radii of 3.16 mm and thicknesses of 292 (micro)m, dimensions similar to magnetically-driven ICF target designs (1). In most tests the MRT instability was seeded with sinusoidal perturbations (λ = 200, 400 (micro)m, peak-to-valley amplitudes of 10, 20 (micro)m, respectively), wavelengths similar to those predicted to dominate near stagnation. Radiographs show the evolution of the MRT instability and the effects of current-induced ablation of mass from the liner surface. Additional Al liner tests used 25-200 (micro)m wavelengths and flat surfaces. Codes being used to design magnetized liner ICF loads (1) match the features seen except at the smallest scales (<50 (micro)m). Recent experiments used Be liners to enable penetrating radiography using the same 6.151 keV diagnostics and provide an in-flight measurement of the liner density profile.

Features analysis for identification of date and party hubs in protein interaction network of Saccharomyces Cerevisiae

Directory of Open Access Journals (Sweden)

Araabi Babak N

2010-12-01

Full Text Available Abstract Background It has been understood that biological networks have modular organizations which are the sources of their observed complexity. Analysis of networks and motifs has shown that two types of hubs, party hubs and date hubs, are responsible for this complexity. Party hubs are local coordinators because of their high co-expressions with their partners, whereas date hubs display low co-expressions and are assumed as global connectors. However there is no mutual agreement on these concepts in related literature with different studies reporting their results on different data sets. We investigated whether there is a relation between the biological features of Saccharomyces Cerevisiae's proteins and their roles as non-hubs, intermediately connected, party hubs, and date hubs. We propose a classifier that separates these four classes. Results We extracted different biological characteristics including amino acid sequences, domain contents, repeated domains, functional categories, biological processes, cellular compartments, disordered regions, and position specific scoring matrix from various sources. Several classifiers are examined and the best feature-sets based on average correct classification rate and correlation coefficients of the results are selected. We show that fusion of five feature-sets including domains, Position Specific Scoring Matrix-400, cellular compartments level one, and composition pairs with two and one gaps provide the best discrimination with an average correct classification rate of 77%. Conclusions We study a variety of known biological feature-sets of the proteins and show that there is a relation between domains, Position Specific Scoring Matrix-400, cellular compartments level one, composition pairs with two and one gaps of Saccharomyces Cerevisiae's proteins, and their roles in the protein interaction network as non-hubs, intermediately connected, party hubs and date hubs. This study also confirms the

Safety analysis report: packages. DOT specification 7A - Type A container Mark 15 sludge shipping package

International Nuclear Information System (INIS)

Zeh, C.W.

1985-03-01

Sludge or filter cake containing 1.1 wt % 235 U enriched uranium from Mark 15 fabrication will be packaged in 55-gallon containers and shipped from SRP to NLO, Fernald, Ohio for recovery of product. About 7 Metric Tons (MT) of filter cake will be produced from fabricating Mark 15 slugs each reactor charge. Packaged shipments of this material, consigned as exclusive use, will be shipped to NLO in Department of Transportation (DOT) Specification 7A - Type A packages under a DOE Certificate of Compliance for Fissile Class III shipments. ''Type A packaging'' is designed to retain containment and shielding integrity under normal conditions of transport. This report documents compliance of the package design, construction methods, material and test performance with DOT Specification 7A. This DOT 7A Type A package contains a carbon steel outer container which is a 0.060-in.-thick 55-gal, galvanized drum equipped with a gasketed closure. The outer container encloses a 0.090-in.-thick, open head, polyethylene liner with lid

Creep and stress relaxation behavior of two soft denture liners.

Science.gov (United States)

Salloum, Alaa'a M

2014-03-01

Numerous investigators stated the indications of soft denture lining materials; but no one determined the indications of these materials according to their chemical structure. The purpose of this investigation was to evaluate the viscoelastic properties of acrylic and silicon lining materials. This study investigated and compared viscoelastic properties of two resilient denture lining materials. Tested materials were laboratory processed; one of them was silicone-based liner product (Molloplast-B), and the other was plasticized acrylic resin (Vertex™ Soft). Twenty cylindrical specimens (10-20 mm in length, 11.55 mm in diameter) were fabricated in an aluminum mold from each material for creep and stress relaxation testing (the study of viscoelastic properties). Tests were performed by using the universal testing machine DY-34. Collected data were analyzed with t test statistics for statistically significant differences at the 95 % confidence level. There was a clear difference in creep and stress relaxation behavior between acrylic and silicone liners. Statistical study of Young's moduli illustrated that Vertex™ Soft was softer than Molloplast-B. On the other hand, the results explained that the recovery of silicone material was better than of acrylic one. The creep test revealed that the plasticized acrylic resin lining material exhibited considerable creep, whereas silicone-based liner exhibited elastic behavior. Besides, the stress relaxation test showed that relaxation of the plasticized acrylic resin material was bigger than of the silicone-based liner.

Reliability-based condition assessment of steel containment and liners

International Nuclear Information System (INIS)

Ellingwood, B.; Bhattacharya, B.; Zheng, R.

1996-11-01

Steel containments and liners in nuclear power plants may be exposed to aggressive environments that may cause their strength and stiffness to decrease during the plant service life. Among the factors recognized as having the potential to cause structural deterioration are uniform, pitting or crevice corrosion; fatigue, including crack initiation and propagation to fracture; elevated temperature; and irradiation. The evaluation of steel containments and liners for continued service must provide assurance that they are able to withstand future extreme loads during the service period with a level of reliability that is sufficient for public safety. Rational methodologies to provide such assurances can be developed using modern structural reliability analysis principles that take uncertainties in loading, strength, and degradation resulting from environmental factors into account. The research described in this report is in support of the Steel Containments and Liners Program being conducted for the US Nuclear Regulatory Commission by the Oak Ridge National Laboratory. The research demonstrates the feasibility of using reliability analysis as a tool for performing condition assessments and service life predictions of steel containments and liners. Mathematical models that describe time-dependent changes in steel due to aggressive environmental factors are identified, and statistical data supporting the use of these models in time-dependent reliability analysis are summarized. The analysis of steel containment fragility is described, and simple illustrations of the impact on reliability of structural degradation are provided. The role of nondestructive evaluation in time-dependent reliability analysis, both in terms of defect detection and sizing, is examined. A Markov model provides a tool for accounting for time-dependent changes in damage condition of a structural component or system. 151 refs

Azimuthal Current Density Distribution Resulting from a Power Feed Vacuum Gap in Metallic Liner Experiments at 1 MA

Science.gov (United States)

Bott-Suzuki, Simon; Cordaro, S. W.; Caballero Bendixsen, L. S.; Atoyan, L.; Byvank, T.; Potter, W.; Kusse, B. R.; Greenly, J. B.; Hammer, D. A.; Chittenden, J. P.; Jennings, C. A.

2015-11-01

We present a study investigating the initiation of plasma in solid, metallic liners where the liner thickness is large compared to the collisionless skin depth. A vacuum gap is introduced in the power feed and we investigate the effect of this on the azimuthal initiation of plasma in the liner. We present optical emission data from aluminum liners on the 1 MA, 100ns COBRA generator. We use radial and axial gated imaging and streak photography, which show a dependence of onset of emission with the size of a small power-feed vacuum gap. The evolution of ``hot-spots'' generated from breakdown vacuum gap evolves relatively slowly and azimuthal uniformity is not observed on the experimental time-scale. We also show measurements of the B-field both outside and inside the liner, using miniature Bdot probes, which show a dependence on the liner diameter and thickness, and a correlation to the details of the breakdown. These data will be compared to magneto-hydrodynamic simulations to infer how such non-uniformities may affect full liner implosion experiments.

A semi-analytic model of magnetized liner inertial fusion

Energy Technology Data Exchange (ETDEWEB)

McBride, Ryan D.; Slutz, Stephen A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

2015-05-15

Presented is a semi-analytic model of magnetized liner inertial fusion (MagLIF). This model accounts for several key aspects of MagLIF, including: (1) preheat of the fuel (optionally via laser absorption); (2) pulsed-power-driven liner implosion; (3) liner compressibility with an analytic equation of state, artificial viscosity, internal magnetic pressure, and ohmic heating; (4) adiabatic compression and heating of the fuel; (5) radiative losses and fuel opacity; (6) magnetic flux compression with Nernst thermoelectric losses; (7) magnetized electron and ion thermal conduction losses; (8) end losses; (9) enhanced losses due to prescribed dopant concentrations and contaminant mix; (10) deuterium-deuterium and deuterium-tritium primary fusion reactions for arbitrary deuterium to tritium fuel ratios; and (11) magnetized α-particle fuel heating. We show that this simplified model, with its transparent and accessible physics, can be used to reproduce the general 1D behavior presented throughout the original MagLIF paper [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)]. We also discuss some important physics insights gained as a result of developing this model, such as the dependence of radiative loss rates on the radial fraction of the fuel that is preheated.

Manufacturing and testing of ITER divertor gas box liners

International Nuclear Information System (INIS)

Mazul, I.; Giniatulin, R.; Komarov, V.L.; Krylov, V.; Kuzmin, Ye.; Makhankov, A.; Odintsov, V.; Zhuk, A.

1998-01-01

Among a variety of R and D works performed by different ITER parties there are seven large projects which deal with the development, manufacturing and testing of most important complex reactor components. One of the projects is directed to produce a prototype of divertor cassette. In according with integration plan two full size liners with dummy armour are manufactured by RF Home Team. Except for liners with dummy armors the large - scale mock-up with real armour have to be manufactured in order to demonstrate the semi-industrial possibilities for joining of Be and W to CuCrZr heat - sink structure. The design of this liners, technological approaches to their manufacturing are presented. The description of brazing facility and joining technology which use a fast ohmic heating by 15 kA current is made. A mock-up of 800 mm in length and 90 mm in width was armored by 18 Be tiles (44 x 44 mm 2 in plane, 10 mm - thick) and 16 W-Cu tiles (44 x 44 mm 2 in plane, 3 mm - thick W). The preliminary results of high heat flux testing of the armored mock-ups are also presented. (author)

Elastic Plastic Fracture Analysis of an Aluminum COPV Liner

Science.gov (United States)

Forth, Scott; Gregg, Bradley; Bailey, Nathaniel

2012-01-01

Onboard any space-launch vehicle, composite over-wrapped pressure vessels (COPVs) may be utilized by propulsion or environmental control systems. The failure of a COPV has the potential to be catastrophic, resulting in the loss of vehicle, crew or mission. The latest COPV designs have reduced the wall-thickness of the metallic liner to the point where the material strains plastically during operation. At this time, the only method to determine the damage tolerance lifetime (safe-life) of a plastically responding metallic liner is through full-scale COPV testing. Conducting tests costs substantially more and can be far more time consuming than performing an analysis. As a result of this cost, there is a need to establish a qualifying process through the use of a crack growth analysis tool. This paper will discuss fracture analyses of plastically responding metallic liners in COPVs. Uni-axial strain tests have been completed on laboratory specimens to collect elastic-plastic crack growth data. This data has been modeled with the crack growth analysis tool, NASGRO 6.20 to predict the response of laboratory specimens and subsequently the complexity of a COPV.

Self-similar compression of a magnetized plasma filled liner

International Nuclear Information System (INIS)

Felber, F.S.; Liberman, M.A.; Velikovich, A.L.

1985-01-01

New analytic, one-dimensional, self-similar solutions of magnetohydrodynamic equations describing the compression of a magnetized plasma by a thin cylindrical liner are presented. The solutions include several features that have not been included in an earlier self-similar solution of the equations of ideal magnetohydrodynamics. These features are the effects of finite plasma electrical conductivity, induction heating, thermal conductivity and related thermogalvanomagnetic effects, plasma turbulence, and plasma boundary effects. These solutions have been motivated by recent suggestions for production of ultrahigh magnetic fields by new methods. The methods involve radially imploding plasmas in which axial magnetic fields have been entrained. These methods may be capable of producing controlled magnetic fields up to approx. = 100 MG. Specific methods of implosion suggested were by ablative radial acceleration of a liner by a laser and by a gas-puff Z pinch. The model presented here addresses the first of these methods. The solutions derived here are used to estimate magnetic flux losses out of the compression volume, and to indicate conditions under which an impulsively-accelerated, plasma-filled liner may compress an axial magnetic field to large magnitude

Functional Hubs in Mild Cognitive Impairment

Science.gov (United States)

Navas, Adrián; Papo, David; Boccaletti, Stefano; Del-Pozo, F.; Bajo, Ricardo; Maestú, Fernando; Martínez, J. H.; Gil, Pablo; Sendiña-Nadal, Irene; Buldú, Javier M.

We investigate how hubs of functional brain networks are modified as a result of mild cognitive impairment (MCI), a condition causing a slight but noticeable decline in cognitive abilities, which sometimes precedes the onset of Alzheimer's disease. We used magnetoencephalography (MEG) to investigate the functional brain networks of a group of patients suffering from MCI and a control group of healthy subjects, during the execution of a short-term memory task. Couplings between brain sites were evaluated using synchronization likelihood, from which a network of functional interdependencies was constructed and the centrality, i.e. importance, of their nodes was quantified. The results showed that, with respect to healthy controls, MCI patients were associated with decreases and increases in hub centrality respectively in occipital and central scalp regions, supporting the hypothesis that MCI modifies functional brain network topology, leading to more random structures.

MODELS AND METHODS FOR LOGISTICS HUB LOCATION: A REVIEW TOWARDS TRANSPORTATION NETWORKS DESIGN

Directory of Open Access Journals (Sweden)

Carolina Luisa dos Santos Vieira

Full Text Available ABSTRACT Logistics hubs affect the distribution patterns in transportation networks since they are flow-concentrating structures. Indeed, the efficient moving of goods throughout supply chains depends on the design of such networks. This paper presents a literature review on the logistics hub location problem, providing an outline of modeling approaches, solving techniques, and their applicability to such context. Two categories of models were identified. While multi-criteria models may seem best suited to find optimal locations, they do not allow an assessment of the impact of new hubs on goods flow and on the transportation network. On the other hand, single-criterion models, which provide location and flow allocation information, adopt network simplifications that hinder an accurate representation of the relationshipbetween origins, destinations, and hubs. In view of these limitations we propose future research directions for addressing real challenges of logistics hubs location regarding transportation networks design.

Epidemics in Complex Networks: The Diversity of Hubs

Science.gov (United States)

Kitsak, Maksim; Gallos, Lazaros K.; Havlin, Shlomo; Stanley, H. Eugene; Makse, Hernan A.

2009-03-01

Many complex systems are believed to be vulnerable to spread of viruses and information owing to their high level of interconnectivity. Even viruses of low contagiousness easily proliferate the Internet. Rumors, fads, and innovation ideas are prone to efficient spreading in various social systems. Another commonly accepted standpoint is the importance of the most connected elements (hubs) in the spreading processes. We address following questions. Do all hubs conduct epidemics in the same manner? How does the epidemics spread depend on the structure of the network? What is the most efficient way to spread information over the system? We analyze several large-scale systems in the framework of of the susceptible/infective/removed (SIR) disease spread model which can also be mapped to the problem of rumor or fad spreading. We show that hubs are often ineffective in the transmission of virus or information owing to the highly heterogeneous topology of most networks. We also propose a new tool to evaluate the efficiency of nodes in spreading virus or information.

Looking Into Pandora's Box: The Content Of Sci-Hub And Its Usage

OpenAIRE

Greshake, Bastian

2017-01-01

Despite the growth of Open Access, potentially illegally circumventing paywalls to access scholarly publications is becoming a more mainstream phenomenon. The web service Sci-Hub is amongst the biggest facilitators of this, offering free access to around 62 million publications. So far it is not well studied how and why its users are accessing publications through Sci-Hub. By utilizing the recently released corpus of Sci-Hub and comparing it to the data of  ~28 million downloads done through ...

Analysis of a ship-to-ship collision

International Nuclear Information System (INIS)

Porter, V.L.; Ammerman, D.J.

1996-01-01

Sandia National Laboratories is involved in a safety assessment for the shipment of radioactive material by sea. One part of this study is investigation of the consequences of ship-to-ship collisions. This paper describes two sets of finite element analyses performed to assess the structural response of a small freighter and the loading imparted to radioactive material (RAM) packages during several postulated collision scenarios with another ship. The first series of analyses was performed to evaluate the amount of penetration of the freighter hull by a striking ship of various masses and initial velocities. Although these analyses included a representation of a single RAM package, the package was not impacted during the collision so forces on the package could not be computed. Therefore, a second series of analyses incorporating a representation of a row of seven packages was performed to ensure direct package impact by the striking ship. Average forces on a package were evaluated for several initial velocities and masses of the striking ship. In addition to. providing insight to ship and package response during a few postulated ship collisions scenarios, these analyses will be used to benchmark simpler ship collision models used in probabilistic risk assessment analyses

Influence of Hub Parameters on Joining Forces and Torque Transmission Output of Plastically-Joined Shaft-Hub-Connections with a Knurled Contact Surface

Directory of Open Access Journals (Sweden)

Lukáš Suchý

2018-04-01

Full Text Available A knurled interference fit is a machine part connection made by a plastic joining, which includes the advantages of commonly-used shaft-hub-connections. The combination of the friction and form fit, which are responsible for torque transmission, results in a higher power density than conventional connections. In this paper, parameter gaps are bridged with the aim of enhance the design calculation of the knurled interference fit. Experimental investigations on the shaft chamfer angle (100Cr6 and hub-diameter-ratio (AlSi1MgMn were performed. The analytical approaches are developed for calculating the joining force and maximal torque capacity by accounting for experimentally investigated loss of load transmission at high hub-diameter-ratios and high shaft chamfer angles. The presented calculation approach is an accurate tool for the assessment of early machine designs of the knurled interference fit and helps to save from having to perform time-extensive tests.

Evaluation of corrosion attack of chimney liners

Directory of Open Access Journals (Sweden)

Blahetová M.

2016-06-01

Full Text Available The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241 was particularly high content of halides (chlorides and fluorides, which caused a severe pitting corrosion, which led up to the perforation of the liner material. Simultaneous reduction of the thickness of the used sheets was due to by the general corrosion, which was caused by the sulfur in the solid fuel. The condensation then led to acid environment and therefore the corrosion below the dew point of the sulfuric acid has occurred. All is documented by metallographic analysis and microanalysis of the corrosion products.

HOST liner cyclic facilities

Science.gov (United States)

Schultz, D.

1983-01-01

The HOST Liner Cyclic Program is utilizing two types of test apparatus, rectangular box rigs and a full annular rig. To date two quartz lamp cyclic box rigs have been tested and a third is to begin testing in late October 1983. The box rigs are used to evaluate 5x8 inch rectangular linear samples. A 21 inch diameter outer liner simulator is also being built up for testing beginning in April 1984. All rigs are atmospheric rigs. The first box rig, a three 6-kVA lamp installation, was operated under adverse conditions to determine feasibility of using quartz lamps for cyclic testing. This work was done in December 1981 and looked promising. The second box rig, again using three 6-kVA lamps, was operated to obtain instrumentation durability information and initial data input to a Finite Element Model. This limited test program was conducted in August 1983. Five test plates were run. Instrumentation consisted of strain gages, thermocouples and thermal paint. The strain gages were found to fail at 1200 F as expected though plates were heated to 1700 F. The third box rig, containing four 6-kVA lamps, is in build up for testing to begin in late October 1983. In addition to 33 percent greater power input, this rig has provision for 400 F backside line cooling air and a viewing port suitable for IR camera viewing. The casing is also water cooled for extended durability.

Economic Impact of the Dutch Gas Hub Strategy on the Netherlands

International Nuclear Information System (INIS)

Harris, D.; Bazelon, C.; Humphreys, B.; Dickson, P.

2010-09-01

Since the discovery of the Groningen gas field in 1959, the Netherlands has been a key player in the European gas market. The Netherlands has built up a large onshore and offshore Exploration and Production sector, it has a highly developed gas transmission and distribution network, and is a major exporter of gas to other EU Member States. The Netherlands has considerable expertise in all parts of the gas supply chain, and is a world centre for Research and development in natural gas supply and use. More recently construction has begun on terminals to allow the import of Liquid Natural Gas to the Netherlands. However, Dutch gas reserves are now in decline, and the Netherlands will become a net importer of gas around 2025. The Dutch government wishes to capitalise on the existing industry and skills and sustain the Netherlands' place in the European gas industry beyond the life of the existing gas fields. In November 2009 the Minister of Economic Affairs published a paper describing the strategy of turning the Netherlands into a 'Gas Hub' or 'gas roundabout' for north-west Europe. The Dutch government intends that the gas hub would capitalise on the existing skills and industry, increase competition and security of supply in the Dutch gas market, create employment and make a significant contribution to the Dutch economy. The Dutch Ministry of Economic Affairs, Agriculture and Innovation has commissioned The Brattle Group to perform an analysis of the economic impact of the gas hub concept. The study has several aims including: To analyse the current contribution of the Dutch gas sector to the economy; To assess the Strengths, Weaknesses, Opportunities and Threats associated with the gas hub strategy; To quantify the benefits of the gas hub strategy to the Dutch economy. Note that the aim of the study is to define in more detail what a successful Dutch gas hub strategy would look like, to assess the strengths and weakness of the Dutch gas sector in achieving a

The Banana Genome Hub

Science.gov (United States)

Droc, Gaëtan; Larivière, Delphine; Guignon, Valentin; Yahiaoui, Nabila; This, Dominique; Garsmeur, Olivier; Dereeper, Alexis; Hamelin, Chantal; Argout, Xavier; Dufayard, Jean-François; Lengelle, Juliette; Baurens, Franc-Christophe; Cenci, Alberto; Pitollat, Bertrand; D’Hont, Angélique; Ruiz, Manuel; Rouard, Mathieu; Bocs, Stéphanie

2013-01-01

Banana is one of the world’s favorite fruits and one of the most important crops for developing countries. The banana reference genome sequence (Musa acuminata) was recently released. Given the taxonomic position of Musa, the completed genomic sequence has particular comparative value to provide fresh insights about the evolution of the monocotyledons. The study of the banana genome has been enhanced by a number of tools and resources that allows harnessing its sequence. First, we set up essential tools such as a Community Annotation System, phylogenomics resources and metabolic pathways. Then, to support post-genomic efforts, we improved banana existing systems (e.g. web front end, query builder), we integrated available Musa data into generic systems (e.g. markers and genetic maps, synteny blocks), we have made interoperable with the banana hub, other existing systems containing Musa data (e.g. transcriptomics, rice reference genome, workflow manager) and finally, we generated new results from sequence analyses (e.g. SNP and polymorphism analysis). Several uses cases illustrate how the Banana Genome Hub can be used to study gene families. Overall, with this collaborative effort, we discuss the importance of the interoperability toward data integration between existing information systems. Database URL: http://banana-genome.cirad.fr/ PMID:23707967

Location of an intermediate hub for port activities

Science.gov (United States)

Burciu, Ş.; Ştefănică, C.; Roşca, E.; Dragu, V.; Ruscă, F.

2015-11-01

An intermediate hub might increase the accessibility level of ports but also hinterland and so it can be considered more than a facility with a transhipment role. These hubs might lead to the development of other transport services and enhance their role in gathering and covering economic centres within hinterlands and also getting the part of logistic facility for the ports, with effects on port utilization and its connectivity to global economy. A new location for a hub terminal leads to reduced transport distances within hinterland, with decreased transport costs and external effects, so with gains in people's life quality. Because the production and distribution systems are relatively fixed on short and medium term and the location decisions are strategic and on long term, the logistic chains activities location models have to consider the uncertainties regarding the possible future situations. In most models, production costs are considered equal, the location problem reducing itself to a problem that aims to minimize the total transport costs, meaning the transport problem. The main objective of the paper is to locate a hub terminal that links the producers of cereals that are going to be exported by naval transportation with the Romanian fluvial-maritime ports (Galaţi, Brăila). GIS environment can be used to integrate and analyse a great amount of data and has the ability of using functions as location - allocation models necessary both to private and public sector, being able to determine the optimal location for services like factories, warehouses, logistic platforms and other public services.

Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

International Nuclear Information System (INIS)

Riesemann, W.A. von; Parks, M.B.

1995-01-01

In the US, concrete containment buildings for commercial nuclear power plants have steel liners that act as the internal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented.This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions).An overpressurization test of a 1:6 scale reinforced concrete containment at Sandia National Laboratories resulted in a failure mechanism in the liner that was not fully anticipated. Post-test analyses and experiments have been conducted to understand the failure better. This work and the activities that followed the test are reviewed. Areas in which additional research should be conducted are given. (orig.)

EFFECTS OF INORGANIC SALT SOLUTION ON SOME PROPERTIES OF COMPACTED CLAY LINERS

Directory of Open Access Journals (Sweden)

KHALID R. MAHMOOD AL-JANABI

2017-12-01

Full Text Available Processed and natural clays are widely used to create impermeable liners in solid waste disposal landfills. The engineering properties of clay liners can be significantly affected by the leachate from the waste mass. In this study, the effect of inorganic salt solutions will be investigated. These solutions used at different concentrations. Two type of inorganic salt MnSO4 and FeCl3 are used at different concentration 2%,5%, 10%. Clay used in this study was the CL- clay (kaolinite. The results show that the consistency limits and unconfined compressive strength increased as the concentration of salts increased. While the permeability tends to decrease as salt concentration increased. Also, the compression index decreases as the concentration increased from 2% to 5%. The swelling index tends to increase slightly as the concentration of MnSO4 increased, while its decrease as the concentration of FeCl3. In this paper, it is aimed to investigate the performance of compacted clay liner exposed to the certain chemicals generated by the leachate and their effects on the geotechnical properties of compacted clay liner such consistency limits, permeability coefficient, compressibility characteristics and unconfined compressive strength.

Flyash and sewage sludge as liner material - Preparations for a pilot test with fly-ash stabilised sewage sludge as landfill liner; Linermaterial med aska och roetslam - Underlag foer genomfoerande av pilotfoersoek med stabiliserat avloppsslam som taetskiktsmaterial

Energy Technology Data Exchange (ETDEWEB)

Macsik, J.; Rogbeck, Y.; Svedberg, B.; Uhlander, O. [Scandiaconsult Sverige AB, Stockholm (Sweden); Mossakowska, A. [Stockholm Vatten AB (Sweden)

2003-11-01

The aim of this project was to develop a new liner material based on biofuel fly ash and sewage sludge and to plan for a pilot test with this new liner (FSA) on a landfill. The investigation shows that FSA has potential to fulfil technical and economical requirements as well as requirements of durability. This project constitutes part of a larger one, where the overall aim is to collect information/experience of FSA as a liner for presentation in a handbook. During the conducted laboratory work recipes for mixture proportions for application as landfill liner were controlled according to technical and environmental aspects. A recipe for FSA material has been prepared, which has permeability values lower than 10-9 m/s. This low permeability can assure a low percolation of precipitated water through the landfill liner, < 50 litre/m{sup 2}/year. FSA has sufficient un-drained shear strength and has an estimated slow bio-degradation, which can assure a long duration period. Based on results from tests conducted in this and other projects, where FSA materials were tested, necessary quality verifications has been conducted for the ingredients bio-fly-ash and sewage sludge and for the FSA-mixture. The FSA materials potential as liner increases with darker colour (bordering black). FSA-40 is a mixture of 40 % dry solid (DS) fly ash and 60 % DS sewage sludge, and FSA-60 is a mixture containing 60 % DS fly ash and 40 % DS sewage sludge and so on. Some important parameters of the ingredient materials are DS content (or water content) and pH and CaO content of the fly ash. A liner made of FSA should have surrounding layers of high water containing capacity in order to protect the FSA-liner from drying. The drainage and oxidation protection layers have to transport precipitated water as well as contain sufficient pore water in order to be an oxygen barrier above the liner (FSA). In addition, the investigation shows that a paddle blender should be used in order to guarantee a

Radioactive wear tests of four cylinder liner materials

International Nuclear Information System (INIS)

Sylte, G.

1976-01-01

An investigation on the wear properties of various liner materials, financed by a research grant from NTNF (Royal Norwegian Council for Scientific and Industrial Research), is reported. The investigation was carried out by the Division of Internal Combustion Engines, Trondheim, Univ.,Norway, on a two-stroke, turbocharged, medium speed diesel engine (Wichmann 2ACAT, 280 by 420 mm). Thin pearlitic cast iron inserts of various compositions were pressed into the upper part of a specially machined cylinder liner. These inserts were activated in a nuclear reactor, and tracer techniques employed to measure the wear rate. Gas oil was used as a fuel throughout all tests. The insert technique employed, and the handling methods devised, were satisfactory. This part of the project must be characterised as being very successful. Originally, six different liner materials were specified, but due to misunderstandings duplications resulted in only four different materials finally being received at the laboratory. The engine tests disclosed that the wear rates of all four materials were low under laboratory conditions, and therefore difficult to measure accurately. Nevertheless, the wear properties of the inserts clearly fell into two distinct classes, which may be termed good and excellent. The relative values inside each group are, however, more uncertain due to the cumulative effects of errors, instrument drift, measurement statistics, etc. (Auth.)

Magnetic pressure effects in a plasma-liner interface

Science.gov (United States)

García-Rubio, F.; Sanz, J.

2018-04-01

A theoretical analysis of magnetic pressure effects in a magnetized liner inertial fusion-like plasma is presented. In previous publications [F. García-Rubio and J. Sanz, Phys. Plasmas 24, 072710 (2017)], the evolution of a hot magnetized plasma in contact with a cold unmagnetized plasma, aiming to represent the hot spot and liner, respectively, was investigated in planar geometry. The analysis was made in a double limit low Mach and high thermal to magnetic pressure ratio β. In this paper, the analysis is extended to an arbitrary pressure ratio. Nernst, Ettingshausen, and Joule effects come into play in the energy balance. The region close to the liner is governed by thermal conduction, while the Joule dissipation becomes predominant far from it when the pressure ratio is low. Mass ablation, thermal energy, and magnetic flux losses are reduced with plasma magnetization, characterized by the electron Hall parameter ω e τ e , until β values of order unity are reached. From this point forward, increasing the electron Hall parameter no longer improves the magnetic flux conservation, and mass ablation is enhanced due to the magnetic pressure gradients. A thoughtful simplification of the problem that allows to reduce the order of the system of governing equations while still retaining the finite β effects is presented and compared to the exact case.

Maritime Domain Awareness Architecture Management Hub Strategy

National Research Council Canada - National Science Library

2008-01-01

This document provides an initial high level strategy for carrying out the responsibilities of the national Maritime Domain Awareness Architecture Management Hub to deliver a standards based service...

Extrapolation of creep behavior of high-density polyethylene liner in the Catch Basin of grout vaults

International Nuclear Information System (INIS)

Whyatt, G.A.

1995-07-01

Testing was performed to determine if gravel particles will creep into and puncture the high-density polyethylene (HDPE) liner in the catch basin of a grout vault over a nominal 30-year period. Testing was performed to support a design without a protective geotextile cover after the geotextile was removed from the design. Recently, a protective geotextile cover over the liner was put back into the design. The data indicate that the geotextile has an insignificant effect on the creep of gravel into the liner. However, the geotextile may help to protect the liner during construction. Two types of tests were performed to evaluate the potential for creep-related puncture. In the first type of test, a very sensitive instrument measured the rate at which a probe crept into HDPE over a 20-minute period at temperatures of 176 degrees F to 212 degrees F (80 degrees C to 100 degrees C). The second type of test consisted of placing the liner between gravel and mortar at 194 degrees F (90 degrees C) and 45.1 psi overburden pressure for periods up to 1 year. By combining data from the two tests, the long-term behavior of the creep was extrapolated to 30 years of service. After 30 years of service, the liner will be in a nearly steady condition and further creep will be extremely small. The results indicate that the creep of gravel into the liner will not create a puncture during service at 194 degrees F (90 degrees C). The estimated creep over 30 years is expected to be less than 25 mils out of the total initial thickness of 60 mils. The test temperature of 194 degrees F (90 degrees C) corresponds to the design basis temperature of the vault. Lower temperatures are expected at the liner, which makes the test conservative. Only the potential for failure of the liner resulting from creep of gravel is addressed in this report

Effects of plasma jet parameters, ionization, thermal conduction, and radiation on stagnation conditions of an imploding plasma liner

Science.gov (United States)

Stanic, Milos

The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal expansion rates and leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ≈ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear

Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses; Yucca Mountain Project

Energy Technology Data Exchange (ETDEWEB)

Glowka, D.A.

1990-09-01

This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs.

Effect of Different Liners on Fracture Resistance of Premolars Restored with Conventional and Short Fiber-Reinforced Composite Resins.

Science.gov (United States)

Shafiei, Fereshteh; Doozandeh, Maryam; Ghaffaripour, Dordaneh

2018-01-11

To see whether applying four different liners under short fiber-reinforced composite (SFRC), everX Posterior, compared to conventional composite resin, Z250, affected their strengthening property in premolar MOD cavities. Mesio-occluso-distal (MOD) cavities were prepared in 120 sound maxillary premolars divided into 10 groups (n = 12) in terms of two composite resin types and 4 liners or no liner. For each composite resin, in 5 groups no liner, resin-modified glass ionomer (RMGI), conventional flowable composite (COFL), self-adhesive flowable composite resin (SAFL), and self-adhesive resin cement (SARC) were applied prior to restoring incrementally. After water storage and thermocycling, static fracture resistance was tested. Data (in Newtons) were analyzed using two-way ANOVA (α = 0.05). Fracture resistance was significantly affected by composite resin type (p = 0.02), but not by the liner (p > 0.05). The interaction of the two factors was not statistically significant (p > 0.05). SFRC exhibited higher fracture strength (1470 ± 200 N) compared to conventional composite resin (1350 ± 290), irrespective of the application of liners. Application of SARC and SAFL liners led to a higher number of restorable fractures for both composite resins. The four liners can be used without interfering with the higher efficacy of SFRC, compared to conventional composite resins, to improve the fracture strength of premolar MOD cavities. © 2018 by the American College of Prosthodontists.

The effect of liner hydraulic conductivity on disposal cell performance

International Nuclear Information System (INIS)

Yu, C.; Yuan, Y.C.; Chia, Y.P.

1988-01-01

Multilayered disposal cells are frequently used for the disposal of radioactive and hazardous wastes. These disposal cells consist of materials with different permeabilities that are placed in various thicknesses at the bottom as well as in the cover of the cell. Typically, a layer of permeable material is placed above a layer with low permeability; the permeable layer functions as a drainage/leachate collection system and the low-permeability layer functions as a migration barrier/liner. This paper analyzes the effects of infiltration through unsaturated soil liners on the long-term performance of the disposal cell. Based on the results of this study, it is concluded that the long-term performance of a disposal cell is dependent on a well-designed cell cover. The design should emphasize a cap with less permeable material to prevent water from infiltrating the disposal cell. An impermeable bottom liner is effective only in the short term; however, it can eventually result in saturation of the wastes and cause the bathtub effect over the long term

HIV protein sequence hotspots for crosstalk with host hub proteins.

Directory of Open Access Journals (Sweden)

Mahdi Sarmady

Full Text Available HIV proteins target host hub proteins for transient binding interactions. The presence of viral proteins in the infected cell results in out-competition of host proteins in their interaction with hub proteins, drastically affecting cell physiology. Functional genomics and interactome datasets can be used to quantify the sequence hotspots on the HIV proteome mediating interactions with host hub proteins. In this study, we used the HIV and human interactome databases to identify HIV targeted host hub proteins and their host binding partners (H2. We developed a high throughput computational procedure utilizing motif discovery algorithms on sets of protein sequences, including sequences of HIV and H2 proteins. We identified as HIV sequence hotspots those linear motifs that are highly conserved on HIV sequences and at the same time have a statistically enriched presence on the sequences of H2 proteins. The HIV protein motifs discovered in this study are expressed by subsets of H2 host proteins potentially outcompeted by HIV proteins. A large subset of these motifs is involved in cleavage, nuclear localization, phosphorylation, and transcription factor binding events. Many such motifs are clustered on an HIV sequence in the form of hotspots. The sequential positions of these hotspots are consistent with the curated literature on phenotype altering residue mutations, as well as with existing binding site data. The hotspot map produced in this study is the first global portrayal of HIV motifs involved in altering the host protein network at highly connected hub nodes.

A realistic structural analysis of the integrity of the liner of reinforced and prestressed concrete containments

International Nuclear Information System (INIS)

Buchhardt, F.; Brandl, P.

1979-01-01

The BWR Gundremmingen II is the first German nuclear power plant with a concrete containment having a thin steel plate liner directly attached to the interior concrete surface to provide an air-tight seal. Due to this monolithic way of anchorage a bonded system of concrete and metal liner membrane is obtained so that the same deformations of the loading or strain conditions are induced to the very stiff concrete hull as well as to the liner. Because of the complex structural behaviour of the bonded system the evaluation is carried out by the finite element method. The overall system is decoupled in several steps. Due to its considerable stiffness the concrete structure can be regarded as the liner supporting basis. The liner system itself might be subdivided into perfect and imperfect sections discretized by plain or curved elements which are supported by point-wise spring elements representing the stud anchors. (orig.)

Elevated lip liner positions improving stability in total hip arthroplasty. An experimental study.

Directory of Open Access Journals (Sweden)

Suleman Qurashi

2018-01-01

Full Text Available Background: The use of elevated lip polyethylene liners with the acetabular component is relatively common in Total Hip Arthroplasty (THA. Elevated lip liners increase stability of the THA by increasing the jump distance in one direction. However, the elevated lip, conversely, also reduces the primary arc in the opposite direction and leads to early impingement of the neck on the elevated lip, potentially causing instability. The aim of the present study is to determine the total range of motion of the femoral head component within the acetabular component with the elevated lip liner in different orientations within the acetabular cup. Methods: We introduce a novel experimental (ex-vivo framework for studying the effects lip liner orientation on the range of motion of the femoral component. For constant acetabular cup orientation, the elevated lip liner was positioned superiorly and inferiorly. The femoral component range of motion in the coronal, sagittal and axial plane was measured. To avoid any confounding influences of out of plane motion, the femoral component was constrained to move in the tested plane. Results: This experimental set up introduces a rigorous framework in which to test the effects of elevated lip liner orientations on the range of motion of the femoral head component in abduction, adduction, flexion, extension and rotation. The movements of this experimental set-up are directly informative of patient’s maximum potential post-operative range of motion. Initial results show that an inferior placement of the elevated lip increases the effective superior lateral range of motion (abduction for the femoral component, whilst the anatomy of the patient (i.e. their other leg prevents the point of femoral component – acetabular lip impingement being reached (in adduction.

Comparative parametric numerical simulations of materials used as liners in the explosively formed projectiles (EFPs)

International Nuclear Information System (INIS)

Hussain, G.; Sanaullah, K.

2009-01-01

A conventional shaped charge comprises a conical metal liner projecting a hyper velocity jet of metal that is able to penetrate to great depths into steel armour. However, misalignment problems exist in tandem with jet break up and spewing particles that greatly diminish its penetration power. An EFP, on the other hand, has a liner in the shape of a geometrical recess. The force of the blast molds the liner into a number of configurations, depending on the geometry and the explosive detonation characteristics. This paper presents comparative parametric numerical simulations of materials used as liners in the explosively formed projectiles EFPs. Numerical simulations are carried out using AUTODYN 2D hydrocode to study effects of liner's materials on the shape, velocity, traveled distance, time, pressure, internal energy, temperature, yield stress, divergence or stability, density, compression, and length to diameter (L/D) ratio of EFPs. These parameters are estimated at the instants of maximum as well as at stable velocities. The parametric study reveals that aluminum has maximum velocity in shortest time among the liner materials. From this reason, it was concluded effective standoff was greater for aluminum than more denser metals. Maximum velocity and traveled distance of Tantalum EFP is found to be minimum which may be due to low thermal softening exponent and larger hardening exponent. The simulated yield stress and pressure developed in the Fe EFP reaches at maximum. The L/D ratio for Copper is found to be maximum which supports maximum penetration. From the stability point of view, 1006 MS is found to be the most reliable liner material due to minimum divergence. Generally all liner materials have similar effects of all parameters like pressure, internal energy, temperature, yield stress, divergence or stability, density, compression at the instants of maximum as well as at stable velocities except L/D ratio of EFPs. At the instant of maximum velocity, L

Energy flow modeling and optimal operation analysis of the micro energy grid based on energy hub

International Nuclear Information System (INIS)

Ma, Tengfei; Wu, Junyong; Hao, Liangliang

2017-01-01

Highlights: • Design a novel architecture for energy hub integrating power hub, cooling hub and heating hub. • The micro energy grid based on energy hub is introduced and its advantages are discussed. • Propose a generic modeling method for the energy flow of micro energy grid. • Propose an optimal operation model for micro energy grid with considering demand response. • The roles of renewable energy, energy storage devices and demand response are discussed separately. - Abstract: The energy security and environmental problems impel people to explore a more efficient, environment friendly and economical energy utilization pattern. In this paper, the coordinated operation and optimal dispatch strategies for multiple energy system are studied at the whole Micro Energy Grid level. To augment the operation flexibility of energy hub, the innovation sub-energy hub structure including power hub, heating hub and cooling hub is put forward. Basing on it, a generic energy hub architecture integrating renewable energy, combined cooling heating and power, and energy storage devices is developed. Moreover, a generic modeling method for the energy flow of micro energy grid is proposed. To minimize the daily operation cost, a day-ahead dynamic optimal operation model is formulated as a mixed integer linear programming optimization problem with considering the demand response. Case studies are undertaken on a community Micro Energy Grid in four different scenarios on a typical summer day and the roles of renewable energy, energy storage devices and demand response are discussed separately. Numerical simulation results indicate that the proposed energy flow modeling and optimal operation method are universal and effective over the entire energy dispatching horizon.

Report on survey on international Hub

International Nuclear Information System (INIS)

Ebisawa, Hirobumi; Hoshino, Junko; Hashimoto, Kazuichiro; Okada, Sohei

2011-03-01

Japan Atomic Energy Agency (JAEA) is promoting initiative to form an international Center of Excellence in line with its aim to accept more researchers/engineers from all over the world. Establishment of 'the Committee for JAEA Internationalization Initiative' was planned in 2010 so as to intensify this initiative, and in February, 2010, we visited research institutions in Europe, which include European Organization for Nuclear Research (CERN), the construction site of ITER in Cadarache, and Rutherford Appleton Laboratory (RAL), with the intention to survey and learn their advanced activities and systems in regard to the International Hub, so that the committee will be able to make fruitful discussion. This report describes strategy taken in each institution for an International Hub, and the state of each institution regarding acceptance and management of overseas researchers and engineers, research environment, living environment/health and welfare, and PR activities/coexistence with the local community. (author)

Ports and pests: Assessing the threat of aquatic invasive species introduced by maritime shipping activity in Cuba.

Science.gov (United States)

O'Brien, Charleen E; Johnston, Matthew W; Kerstetter, David W

2017-12-15

Aquatic invasive species (AIS) are biological pollutants that cause detrimental ecological, economic, and human-health effects in their introduced communities. With increasing globalization through maritime trade, ports are vulnerable to AIS exposure via commercial vessels. The Cuban Port of Mariel is poised to become a competitive transshipment hub in the Caribbean and the intent of this study was to evaluate present and potential impacts AIS pose with the likely future increase in shipping activity. We utilized previous assessment frameworks and publicly accessible information to rank AIS by level of threat. Fifteen AIS were identified in Cuba and one, the Asian green mussel Perna viridis (Linnaeus, 1758), had repeated harmful economic impacts. Five species associated with trade partners of Port Mariel were considered potentially detrimental to Cuba if introduced through shipping routes. The results presented herein identify species of concern and emphasize the importance of prioritizing AIS prevention and management within Cuba. Copyright © 2017 Elsevier Ltd. All rights reserved.

AREVA NP Liner Repair Strategy with Adhesive Technology

International Nuclear Information System (INIS)

Georg, Kraemer; Revoirard, Sebastien; McCann, James-E.

2012-09-01

AREVA has developed a repair method for sealing leakages in austenitic stainless steel liners, especially in nuclear power plants. This technology is either a repair, when applied after failures already occurred, or a prophylaxis, when applied before failures occurred. Leakages of stainless steel pool liners can be classified into basically four mechanisms: Mechanical impact, mechanical stress, weld failures and corrosion. Damage from mechanical impact like dropping tools or equipment can be usually recognized and localized immediately. In such situations no extensive leak detection needs to be performed. Contrary to the mechanical damage, it is more difficult to localize damages due to mechanical stress, such as load changes or thermal stress. Load changes occur when a stainless steel pool is repeatedly filled and drained, thermal stress occurs when a pool is exposed to temperature gradients. Those two preconditions are given in reactor cavities (RC). Mechanical stress usually promotes other pre-existing defects. According to the experience of AREVA the weld failures are not a common root cause for leakages, found after several years of operation. They are due to the standard testing procedure in which all weld seams are checked (with e.g. Penetrate Testing (PT) for example). If failures are detected, they are repaired during the commissioning. The main root cause for leakages found after several years of operation is corrosion. Corrosion failures themselves are mainly caused by stress corrosion cracking (SCC). SCC needs certain preconditions to initiate: Mechanical stress must exist; a corrosion initiating element (e.g. chlorine) above a limiting concentration is necessary as well as a heat affected zone (HAZ). In the HAZ, which is exists near weld seams, the microstructure of the stainless steel has changed. This leads to a higher susceptibility to SCC. Those preconditions for SCC cannot be found at the front side of the liner (water side), because the water

Modeling and optimization of a network of energy hubs to improve economic and emission considerations

International Nuclear Information System (INIS)

Maroufmashat, Azadeh; Elkamel, Ali; Fowler, Michael; Sattari, Sourena; Roshandel, Ramin; Hajimiragha, Amir; Walker, Sean; Entchev, Evgueniy

2015-01-01

Energy hubs that incorporate a variety of energy generation and energy transformation technologies can be used to provide the energy storage needed to enable the efficient operation of a ‘smart energy network’. When these hubs are combined as a network and allowed to exchange energy, they create efficiency advantages in both financial and environmental performance. Further, the interconnectedness of the energy network design provides an added layer of reliability. In this paper, a complex network of energy hubs is modeled and optimized under different scenarios to examine both the financial viability and potential reduction of greenhouse gas emissions. Two case studies consisting of two and three energy hubs within a network are considered. The modeling Scenarios vary according to the consideration of distributed energy systems and energy interaction between energy hubs. In the case of a network of two energy hubs, there is no significant economic or emissions benefit with only a 0.5% reduction in total cost and 3% reduction in CO_2 emission. In the case of a network of three energy hubs, there is a significant economic benefit ranging from 11% to 29%, and 11% emission reduction benefit, as well as a 13% reduction in natural gas consumption. - Highlights: • The generic form of the modified energy hub concept with network model is presented. • Two case studies are presented to demonstrate the benefits of energy hub network. • Distributed energy is shown to provide economic and environmental advantages. • Multi criteria optimization of the economic and environmental performance is done.

Disrupted Nodal and Hub Organization Account for Brain Network Abnormalities in Parkinson's Disease.

Science.gov (United States)

Koshimori, Yuko; Cho, Sang-Soo; Criaud, Marion; Christopher, Leigh; Jacobs, Mark; Ghadery, Christine; Coakeley, Sarah; Harris, Madeleine; Mizrahi, Romina; Hamani, Clement; Lang, Anthony E; Houle, Sylvain; Strafella, Antonio P

2016-01-01

The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson's disease (PD). This study aimed to investigate functional changes in sensorimotor and cognitive networks in Parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls (HCs) and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the HC and patient groups. We found nodal and hub changes in patients compared with HCs, including the right pre-supplementary motor area (SMA), left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex (DLPFC), and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e., right pre-SMA and right mid-insula) displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral DLPFC possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of PD.

A collaborative scheduling model for the supply-hub with multiple suppliers and multiple manufacturers.

Science.gov (United States)

Li, Guo; Lv, Fei; Guan, Xu

2014-01-01

This paper investigates a collaborative scheduling model in the assembly system, wherein multiple suppliers have to deliver their components to the multiple manufacturers under the operation of Supply-Hub. We first develop two different scenarios to examine the impact of Supply-Hub. One is that suppliers and manufacturers make their decisions separately, and the other is that the Supply-Hub makes joint decisions with collaborative scheduling. The results show that our scheduling model with the Supply-Hub is a NP-complete problem, therefore, we propose an auto-adapted differential evolution algorithm to solve this problem. Moreover, we illustrate that the performance of collaborative scheduling by the Supply-Hub is superior to separate decision made by each manufacturer and supplier. Furthermore, we also show that the algorithm proposed has good convergence and reliability, which can be applicable to more complicated supply chain environment.

Conceptual design of the Fast-Liner Reactor (FLR) for fusion power

International Nuclear Information System (INIS)

Moses, R.W.; Krakowski, R.A.; Miller, R.L.

1979-02-01

The generation of fusion power from the Fast-Liner Reactor (FLR) concept envisages the implosion of a thin (3-mm) metallic cylinder (0.2-m radius by 0.2-m length) onto a preinjected plasma. This plasma would be heated to thermonuclear temperatures by adiabatic compression, pressure confinement would be provided by the liner inertia, and thermal insulation of the wall-confined plasma would be established by an embedded azimuthal magnetic field. A 2- to 3-mu s burn would follow the approx. 10 4 m/s radial implosion and would result in a thermonuclear yield equal to 10 to 15 times the energy initially invested into the liner kinetic energy. For implosions occurring once every 10 s a gross thermal power of 430 MWt would be generated. The results of a comprehensive systems study of both physics and technology (economics) optima are presented. Despite unresolved problems associated with both the physics and technology of the FLR, a conceptual power plant design is presented

Issues with Strong Compression of Plasma Target by Stabilized Imploding Liner

Science.gov (United States)

Turchi, Peter; Frese, Sherry; Frese, Michael

2017-10-01

Strong compression (10:1 in radius) of an FRC by imploding liquid metal liners, stabilized against Rayleigh-Taylor modes, using different scalings for loss based on Bohm vs 100X classical diffusion rates, predict useful compressions with implosion times half the initial energy lifetime. The elongation (length-to-diameter ratio) near peak compression needed to satisfy empirical stability criterion and also retain alpha-particles is about ten. The present paper extends these considerations to issues of the initial FRC, including stability conditions (S*/E) and allowable angular speeds. Furthermore, efficient recovery of the implosion energy and alpha-particle work, in order to reduce the necessary nuclear gain for an economical power reactor, is seen as an important element of the stabilized liner implosion concept for fusion. We describe recent progress in design and construction of the high energy-density prototype of a Stabilized Liner Compressor (SLC) leading to repetitive laboratory experiments to develop the plasma target. Supported by ARPA-E ALPHA Program.

Vertical and horizontal liners. Expert seminar; Vertikale und horizontale Abdichtungssysteme. Fachseminar

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, M.; Schulz, T. [comps.

2000-07-01

The seminar presented new findings in the fields of surface coverings and alternative liners, vertical liners (with a contribution on developments in Great Britain), and basic constructive problems of liner systems. Another session discussed problems, experience and developments of sealing walls, especially quality assurance measures during sealing wall construction. Apart from presenting a status report, the seminar also intended to provide a basis for an exchange of experience between the attendants. [German] Ein Schwerpunkt des diesjaehrigen Deponieseminars ist die Darstellung von neuen Erkenntnissen und Erfahrungen mit Oberflaechenabdichtungen und mit alternativen Dichtungssystemen fuer Deponien. Weiterhin werden vertikale Abdichtungen behandelt, fuer die ein Beitrag ueber Entwicklungen in Grossbritannien vorliegt sowie grundsaetzliche konstruktive Fragen zu Abdichtungssystemen. Der weitere Seminarschwerpunkt behandelt Problemstellungen, Erfahrungen und Entwicklungen der Dichtwandtechnologie, insbesondere Qualitaetssicherungsmassnahmen waehrend des Dichtwandbaus. Das Ziel des Seminars ist es, einerseits den Stand der Technik und der Forschung darzustellen, andererseits aber die Moeglichkeit zu bieten, Erfahrungen und Informationen auszutauschen. (orig.)

Simulation Study of Structure and Properties of Plasma Liners for the PLX- α Project

Science.gov (United States)

Samulyak, Roman; Shih, Wen; Hsu, Scott; PLX-Alpha Team

2017-10-01

Detailed numerical studies of the propagation and merger of high-Mach-number plasma jets and the formation and implosion of plasma liners have been performed using the FronTier code in support of the Plasma Liner Experiment-ALPHA (PLX- α) project. Physics models include radiation, physical diffusion, plasma-EOS models, and an anisotropic diffusion model that mimics deviations from fully collisional hydrodynamics in outer layers of plasma jets. Detailed structure and non-uniformity of plasma liners of due to primary and secondary shock waves have been studies as well as averaged quantities of ram pressure and Mach number. Synthetic data from simulations have been compared with available experimental data from a multi-chord interferometer and survey and high-resolution spectrometers. Numerical studies of the sensitivity of liner properties to experimental errors in the initial masses of jets and the synchronization of plasma gun valves have also been performed. Supported by the ARPA-E ALPHA program.

Formation of metal and dielectric liners using a solution process for deep trench capacitors.

Science.gov (United States)

Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

2012-07-01

We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor.

Study on Economic Regulation of Collaborative Strategies among Container Shipping Companies Following Repeal of European Union Regulation 4056/86

Directory of Open Access Journals (Sweden)

Rawindaran Nair

2016-06-01

Full Text Available The European Union removed the block exemption granted under Regulation 4056/86, to liner shipping companies to provide scheduled services on a collaborative basis effective October 2008. This has also been followed by the proposed P3 alliance with participation of Maersk, MSC and CMA CGM. This paper explores, the arguments adopted by the US Federal Maritime Commission, the European Commission and the Ministry of Commerce of China, in rejecting the case proposed by the P3 alliance. The findings of this paper will inform on understanding strategies adopted by major Competition Regulatory authorities in their interpretation of horizontal collaboration in the industry.

Fatigue based design and analysis of wheel hub for Student formula car by Simulation Approach

Science.gov (United States)

Gowtham, V.; Ranganathan, A. S.; Satish, S.; Alexis, S. John; Siva kumar, S.

2016-09-01

In the existing design of Wheel hub used for Student formula cars, the brake discs cannot be removed easily since the disc is mounted in between the knuckle and hub. In case of bend or any other damage to the disc, the replacement of the disc becomes difficult. Further using OEM hub and knuckle that are used for commercial vehicles will result in increase of unsprung mass, which should be avoided in Student formula cars for improving the performance. In this design the above mentioned difficulties have been overcome by redesigning the hub in such a way that the brake disc could be removed easily by just removing the wheel and the caliper and also it will have reduced weight when compared to existing OEM hub. A CAD Model was developed based on the required fatigue life cycles. The forces acting on the hub were calculated and linear static structural analysis was performed on the wheel hub for three different materials using ANSYS Finite Element code V 16.2. The theoretical fatigue strength was compared with the stress obtained from the structural analysis for each material.

Strategies for contracting gas storage and hub services

International Nuclear Information System (INIS)

Auld, J.

1996-01-01

The many efficiencies that can be gained by the natural gas industry in effectively using storage, were demonstrated. The circumstances under which the natural gas industry uses storage and how Market Centres or Hub Services can be strategically used in offering companies the highest flexibility in a tough marketplace, were explained. For example, in North America, storage played an important role during the winter of 95/96, which will be remembered for its extreme cold. That year provided the first true opportunity to test the natural gas delivery system since deregulation in 1985. The fact that natural gas supplies continued to be delivered throughout the entire winter was attributed to the use of stored gas held in reserves to meet the severe demand. The companies that did well, relied on storage and also on the services offered by Hub Services which increased margins for all players in the natural gas industry. Using storage, companies can ensure that field deliveries of gas are kept constant by having storage facilities absorb the swings in market demand. The companies that learn to use storage effectively can create competitive edges over their competition and provide more value to their customers. The three main categories of hub services were also described. These are parking (interruptible storage), gas loans (stored gas can be offered to customers on a term basis for low daily rates), and title exchange (the transfer of gas between buyer and seller). The strategic use of parking, loaned gas, title exchange, direct connections, and InterHub Services can provide customers even greater benefits than are provided by storage-based services. 6 figs

High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines

Science.gov (United States)

Bhat, Biliyar N.; Ellis, David; Singh, Jogender

2014-01-01

Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion

Matrix logistics indicators assessment of distributed transport hub

Directory of Open Access Journals (Sweden)

Igor Arefyev

2014-06-01

Full Text Available Background: The paper is devoted to the distributed transport hub substantiation and assessment. The paper  was an example of the technique and form an array of logistical factors as variables that determine this condition. Experience in organizing multimodal transport showed that the "bottleneck" of transport logistics are items of cargo handling ports, terminals, freight stations and warehouses. At the core of the solution of these problems is the problem of estimating the variables determine the Multi-purpose Hubs. The aim is to develop a method of forming the system of logistical multiplying factors determine the role of each of the types in the technologiacal process of distributed Multi-purpose Hubs. Methods: The assessment model for the formation of Distributed Transport Units  can be based on formal methods to predict the behavior of complex systems engineering complexes. Then one of the approaches to the solution of the problem may be the matrix method of technological factors. Results and conclusions: The proposed methodology of the selection and validation of logistic coefficients has the practical importance in the models development for assessing the condition and behavior of Distributed Transport.

SPARK: Sparsity-based analysis of reliable k-hubness and overlapping network structure in brain functional connectivity.

Science.gov (United States)

Lee, Kangjoo; Lina, Jean-Marc; Gotman, Jean; Grova, Christophe

2016-07-01

Functional hubs are defined as the specific brain regions with dense connections to other regions in a functional brain network. Among them, connector hubs are of great interests, as they are assumed to promote global and hierarchical communications between functionally specialized networks. Damage to connector hubs may have a more crucial effect on the system than does damage to other hubs. Hubs in graph theory are often identified from a correlation matrix, and classified as connector hubs when the hubs are more connected to regions in other networks than within the networks to which they belong. However, the identification of hubs from functional data is more complex than that from structural data, notably because of the inherent problem of multicollinearity between temporal dynamics within a functional network. In this context, we developed and validated a method to reliably identify connectors and corresponding overlapping network structure from resting-state fMRI. This new method is actually handling the multicollinearity issue, since it does not rely on counting the number of connections from a thresholded correlation matrix. The novelty of the proposed method is that besides counting the number of networks involved in each voxel, it allows us to identify which networks are actually involved in each voxel, using a data-driven sparse general linear model in order to identify brain regions involved in more than one network. Moreover, we added a bootstrap resampling strategy to assess statistically the reproducibility of our results at the single subject level. The unified framework is called SPARK, i.e. SParsity-based Analysis of Reliable k-hubness, where k-hubness denotes the number of networks overlapping in each voxel. The accuracy and robustness of SPARK were evaluated using two dimensional box simulations and realistic simulations that examined detection of artificial hubs generated on real data. Then, test/retest reliability of the method was assessed

Growth of Rayleigh-Taylor and bulk convective instabilities in dynamics of plasma liners and pinches

International Nuclear Information System (INIS)

Bud'ko, A.B.; Velikovich, A.L.; Liberman, M.A.; Felber, F.S.

1989-01-01

Perturbation growth is studied for the initial, linear stage of an instability development in the course of a cylindrically-symmetric compression and expansion of plasma liners and Z-pinches with a sharp boundary. The hydrodynamic instabilities are Rayleigh-Taylor and bulk convective ones, the former being the most dengerous. Classification of the instability modes developing in accelerated plasmas, inclusing the local and global Rayleigh-Taylor modes, is given. The spectra of the instability growth rates are calculated for plasma liners and Z-pinches. The properties of the spectra appear to explain the filamentation and stratification of plasmas observed in the experiments with liners and Z-pinches. An axial magnetic field is shown to create a window of stability in the space of the flow parameters, where th Rayleigh-Taylor modes are fully suppressed by the magnetic shear, and the bulk convective ones - to a considerable extent. The axial magnetic field required to stabilize the implosion of a liner is estimated as B z0 =(10-30 kG)I(MA)/R 0 (cm), where I is the average current, R 0 - the initial radius of the liner

Towards Real Time Simulation of Ship-Ship Interaction

DEFF Research Database (Denmark)

Lindberg, Ole; Bingham, Harry B.; Engsig-Karup, Allan Peter

2012-01-01

We present recent and preliminary work directed towards the development of a simplified, physics-based model for improved simulation of ship-ship interaction that can be used for both analysis and real-time computing (i.e. with real-time constraints due to visualization). The goal is to implement...... accurate (realistic) and much faster ship-wave and ship-ship simulations than are currently possible. The coupling of simulation with visualization should improve the visual experience such that it can be perceived as more realistic in training. Today the state-of-art in real-time ship-ship interaction...... is for efficiency reasons and time-constraints in visualization based on model experiments in towing tanks and precomputed force tables. We anticipate that the fast, and highly parallel, algorithm described by Engsig-Karup et al. [2011] for execution on affordable modern high-throughput Graphics Processing Units...

Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

Energy Technology Data Exchange (ETDEWEB)

Lafitte, R.; Marchand, J. D. [Bonnard et Gardel, Ingenieurs-Conseil, Lausanne (Switzerland)

1981-01-15

The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed.

Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

International Nuclear Information System (INIS)

Lafitte, R.; Marchand, J.D.

1981-01-01

The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed

Surface-micromachined rotatable member having a low-contact-area hub

Science.gov (United States)

Rodgers, M. Steven; Sniegowski, Jeffry J.; Krygowski, Thomas W.

2003-11-18

A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

Surface--micromachined rotatable member having a low-contact-area hub

Science.gov (United States)

Rodgers, M. Steven; Sniegowski, Jeffry J.

2002-01-01

A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

A Collaborative Scheduling Model for the Supply-Hub with Multiple Suppliers and Multiple Manufacturers

Directory of Open Access Journals (Sweden)

Guo Li

2014-01-01

Full Text Available This paper investigates a collaborative scheduling model in the assembly system, wherein multiple suppliers have to deliver their components to the multiple manufacturers under the operation of Supply-Hub. We first develop two different scenarios to examine the impact of Supply-Hub. One is that suppliers and manufacturers make their decisions separately, and the other is that the Supply-Hub makes joint decisions with collaborative scheduling. The results show that our scheduling model with the Supply-Hub is a NP-complete problem, therefore, we propose an auto-adapted differential evolution algorithm to solve this problem. Moreover, we illustrate that the performance of collaborative scheduling by the Supply-Hub is superior to separate decision made by each manufacturer and supplier. Furthermore, we also show that the algorithm proposed has good convergence and reliability, which can be applicable to more complicated supply chain environment.

A Collaborative Scheduling Model for the Supply-Hub with Multiple Suppliers and Multiple Manufacturers

Science.gov (United States)

Lv, Fei; Guan, Xu

2014-01-01

This paper investigates a collaborative scheduling model in the assembly system, wherein multiple suppliers have to deliver their components to the multiple manufacturers under the operation of Supply-Hub. We first develop two different scenarios to examine the impact of Supply-Hub. One is that suppliers and manufacturers make their decisions separately, and the other is that the Supply-Hub makes joint decisions with collaborative scheduling. The results show that our scheduling model with the Supply-Hub is a NP-complete problem, therefore, we propose an auto-adapted differential evolution algorithm to solve this problem. Moreover, we illustrate that the performance of collaborative scheduling by the Supply-Hub is superior to separate decision made by each manufacturer and supplier. Furthermore, we also show that the algorithm proposed has good convergence and reliability, which can be applicable to more complicated supply chain environment. PMID:24892104

Skin friction on a flat perforated acoustic liner

Science.gov (United States)

Boldman, D. R.; Brinich, P. F.

1976-01-01

The report concerns the measurement of friction coefficients of a typical perforated acoustic liner installed in the side of a wind tunnel. The results are compared with measured friction coefficients of a smooth hard wall for the same mean flow velocities in a wind tunnel. At a velocity of 61 m/sec, an increase in the local skin coefficient of only a few percent was observed, but at the highest velocity of 213 m/sec an increase of about 20% was obtained. This velocity is a realistic velocity for turbo-machinery components utilizing such liners, so a loss in performance is to be expected. Some tests were also performed to see if changes in the mean boundary layer induced by imposed noise would result in friction increase, but only at low velocity levels was such an increase in friction noted.

A note on hierarchical hubbing for a generalization of the VPN problem

NARCIS (Netherlands)

N.K. Olver (Neil)

2016-01-01

textabstractRobust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. In this context, Fréchette et al. (2013) recently explored hierarchical hubbing: a routing strategy involving a multiplicity of "hubs" connected to

A note on hierarchical hubbing for a generalization of the VPN problem

NARCIS (Netherlands)

Olver, Neil

2016-01-01

Robust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. In this context, Fréchette et al. (2013) recently explored hierarchical hubbing: a routing strategy involving a multiplicity of "hubs" connected to terminals

Robust Energy Hub Management Using Information Gap Decision Theory

DEFF Research Database (Denmark)

Javadi, Mohammad Sadegh; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

2017-01-01

This paper proposes a robust optimization framework for energy hub management. It is well known that the operation of energy systems can be negatively affected by uncertain parameters, such as stochastic load demand or generation. In this regard, it is of high significance to propose efficient...... tools in order to deal with uncertainties and to provide reliable operating conditions. On a broader scale, an energy hub includes diverse energy sources for supplying both electrical load and heating/cooling demands with stochastic behaviors. Therefore, this paper utilizes the Information Decision Gap...

The shipping man adventures in ship finance

CERN Document Server

McCleery, Matthew

2013-01-01

When restless New York City hedge fund manager Robert Fairchild watches the Baltic Dry Cargo Index plunge 97%, registering an all-time high and a 25-year low within the span of just six months, he decides to buy a ship. Immediately fantasizing about naming a vessel after his wife, carrying a string of worry beads and being able to introduce himself as a "shipowner" at his upcoming college reunion, Fairchild immediately embarks on an odyssey into the most exclusive, glamorous and high stakes business in the world. From pirates off the coast of Somalia and on Wall Street to Greek and Norwegian shipping magnates, the education of Robert Fairchild is an expensive one. In the end, he loses his hedge fund, but he gains a life - as a Shipping Man. Part fast paced financial thriller, part ship finance text book, The Shipping Man is 310 pages of required reading for anyone with an interest in capital formation for shipping.

Innovation Hub How-To

DEFF Research Database (Denmark)

Berger, Andreas; Brem, Alexander

2016-01-01

in establishing an innovative environment: carefully considering the decision to set up such a center, hiring the right people, designing a framework for effective output, creating a buffer from bureaucratic distractions, securing a leader to champion the effort, focusing on business outcomes, fostering...... disruptive over incremental innovation, and being patient. Regardless of where an innovation hub is established, the key to success lies in hiring creative, intrinsically motivated staff and then giving them the freedom to do what they do best....

Are nuclear ships environmentally safer than conventionally powered ships

International Nuclear Information System (INIS)

Bone, C.A.; Molgaard, C.A.; Helmkamp, J.C.; Golbeck, A.L.

1988-01-01

An epidemiologic analysis was conducted to determine if risk of hospitalization varied by age, ship type, or occupation between nuclear and conventional powered ship crews in the U.S. Navy. Study cohorts consisted of all male enlisted personnel who served exclusively aboard conventional or nuclear powered aircraft carriers and cruisers during the years 1975-1979; cases were those men hospitalized during this period (N = 48,242). Conventional ship personnel showed significantly elevated rates of injury and disease when compared to nuclear ship personnel. The largest relative risks by age occurred for conventional ship crewmen less than 30 years old. Seaman, logistics (supply), and healthcare personnel serving aboard conventional ships comprised the occupational groups exhibiting the highest hospitalization rate differentials. The results strongly suggest that nuclear ships provide a healthier, safer working and living environment than conventional ships

Shipping

NARCIS (Netherlands)

Wijnolst, N.; Wergeland, T.

1996-01-01

Shipping is a multi-faceted industry which is rather complex to define from an academic point of view. This book attempts to grasp these complexities and provide the reader with an overview of the main topics and terminology in shipping. The book is based on material from our courses in shipping at

Exploring hubness in Regional Trade Agreements

NARCIS (Netherlands)

Vaal, A. de

2016-01-01

In the plethora of Regional Trade Agreements (RTAs) some countries take in a more central position than others in the sense that some countries are much more engaged with other countries through RTAs. Furthermore, the position of some countries is that of a hub: they have (many) trade

FORENSIC INVESTIGATION OF A GENERATION OLD CIPP LINER

Science.gov (United States)

There is limited information regarding the in-situ performance of rehabilitation methods used for prolonging the service life of buried municipal pipeline systems. With some CIPP liners nearly 30 years in service, municipalities are expressing a strong interest in the collection ...

Gas and LNG pricing and trading hub in East Asia: An introduction

Directory of Open Access Journals (Sweden)

Xunpeng Shi

2016-10-01

Full Text Available This paper summarizes the four papers in the special issues on ‘Gas and LNG pricing and trading hub in East Asia’. The papers examine lessons and experience from European hub development, other commodity, the Japanese history on developing of futures markets and inter-fuel substitution in East Asia. The papers finds that liquid futures market is the key to formulate benchmark prices while a well-developed spot market is the foundation; political will and strong leadership are required to overcome the power of incumbents and to restructure the gas market that impede the the development of competitive markets; and East Asia needs to develop its indigenous gas or LNG trading hubs even in low oil prices period and its developing market allows easier changes in new contracts than in existing ones. This hub development requires governments to go through tough domestic market reforms, including liberalization and cooperation with each other and with gas exporters.

Recyclability of mixed office waste papers containing pressure sensitive adhesives and silicone release liners

Science.gov (United States)

Julie Hess; Roberta Sena-Gomes; Lisa Davie; Marguerite Sykes

2001-01-01

Increased use of pressure sensitive adhesives for labels and stamps has introduced another contaminant into the office paper stream: silicone- coated release liners. This study examines methods and conditions for removal of contaminants, including these liners, from a typical batch of discarded office papers. Removal of contaminants contained in the furnish were...

Medium-term energy hub management subject to electricity price and wind uncertainty

International Nuclear Information System (INIS)

Najafi, Arsalan; Falaghi, Hamid; Contreras, Javier; Ramezani, Maryam

2016-01-01

Highlights: • A new model for medium-term energy hub management is proposed. • Risk aversion is considered in medium-term energy hub management. • Stochastic programing is used to solve the medium-term energy hub management problem. • Electricity price and wind uncertainty are considered. - Abstract: Energy hubs play an important role in implementing multi-carrier energy systems. More studies are required in both their modeling and operating aspects. In this regard, this paper attempts to develop medium-term management of an energy hub in restructured power systems. A model is presented to manage an energy hub which has electrical energy and natural gas as inputs and electrical and heat energy as outputs. Electricity is procured in various ways, either purchasing it from a pool-based market and bilateral contracts, or producing it from a Combined Heat and Power (CHP) unit, a diesel generator unit and Wind Turbine Generators (WTGs). Pool prices and wind turbine production are subject to uncertainty, which makes energy management a complex puzzle. Heat demand is also procured by a furnace and a CHP unit. Energy hub managers should make decisions whether to purchase electricity from the electricity market and gas from the gas network or to produce electricity using a set of generators to meet the electrical and heat demands in the presence of uncertainties. The energy management objective is to minimize the total cost subject to several technical constraints using stochastic programming. Conditional Value at Risk (CVaR), a well-known risk measure, is used to reduce the unfavorable risk of costs. In doing so, the proposed model is illustrated using a sample test case with actual prices, load and wind speed data. The results show that the minimum cost is obtained by the best decisions involving the electricity market and purchasing natural gas for gas facilities. Considering risk also increases the total expected cost and decreases the CVaR.

Hub network design for sparse travel demand within the African aviation industry

CSIR Research Space (South Africa)

Ssamula, B

2007-07-01

Full Text Available and analysed to reveal that the best option for a hub network is the so-called geo-political network. A geo-political network is where hubs are created in the North, South, East and West of Africa, at airports with strong political influence, high passenger...

Design and Analysis of Wind Turbine Blade Hub using Aluminium Alloy AA 6061-T6

Science.gov (United States)

Ravikumar, S.; Jaswanthvenkatram, V.; Sai kumar, Y. J. N. V.; Sohaib, S. Md.

2017-05-01

This work presents the design and analysis of horizontal axis wind turbine blade hub using different material. The hub is very crucial part of the wind turbine, which experience the loads from the blades and the loads were transmitted to the main shaft. At present wind turbine is more expensive and weights more than a million pounds, with the nacelle, rotor hub and blades accounting for most of the weight. In this work Spheroidal graphite cast iron GGG 40.3 is replaced by aluminium alloy 6061-T6 to enhance the casting properties and also to improve the strength-weight ratio. This transition of material leads to reduction in weight of the wind turbine. All the loads caused by wind and extreme loads on the blades are transferred to the hub. Considering the IEC 61400-1 standard for defining extreme loads on the hub the stress and deflection were calculated on the hub by using Finite element Analysis. Result obtained from ANSYS is compared and discussed with the existing design.

Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

Science.gov (United States)

Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; Jordan, N. M.; Lau, Y. Y.; Gilgenbach, R. M.

2015-11-01

In this work, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ˜600 kA with ˜200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. This technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.

Engineering and innovative erection concept for the containment liner for a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Goehring, Rainer [Babcock Noell GmbH, Wuerzburg (Germany). Abt. Nukleare Projekte; Anders, Nils; Nagelstutz, Franz [Babcock Noell GmbH, Wuerzburg (Germany). Abt. Berechnung

2010-04-15

The determination of the optimal design of the containment liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. Several load cases for normal operation and accidental conditions as well as severe accidents have been analysed. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. The construction costs of a Nuclear Power Plant are also impacted by the erection time of components. Therefore, it is necessary to optimize the erection times and consequently essentially to shorten. One possibility has been demonstrated by Babcock Noell GmbH with the erection concept of a containment liner. The liner is preassembled on the pre-assembly place in rings of up to 12 meter height, with the nominal diameter of 47 meter and a weight of approximately up to 200 tonnes. These rings, as well as the containment cup and the dome, are lifted with a heavy load crane into the reactor building. With this concept, the construction activities on the inner containment wall are only five times disrupted by the welding and coating of the circumferential weld (approx. 25 calendar days). In comparison with the common known erection concept of welding of liner shells in situ, at least 20 weeks are saved on the schedule. An integrated concept from planning, manufacturing and erection of this large component has been implemented. It could be demonstrated that within the given time frame, with the required quality and within the required tolerances the containment liner for the Nuclear Power Plant can be delivered to the Client. (orig.)

Engineering and innovative erection concept for the containment liner for a nuclear power plant

International Nuclear Information System (INIS)

Goehring, Rainer; Anders, Nils; Nagelstutz, Franz

2010-01-01

The determination of the optimal design of the containment liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. Several load cases for normal operation and accidental conditions as well as severe accidents have been analysed. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. The construction costs of a Nuclear Power Plant are also impacted by the erection time of components. Therefore, it is necessary to optimize the erection times and consequently essentially to shorten. One possibility has been demonstrated by Babcock Noell GmbH with the erection concept of a containment liner. The liner is preassembled on the pre-assembly place in rings of up to 12 meter height, with the nominal diameter of 47 meter and a weight of approximately up to 200 tonnes. These rings, as well as the containment cup and the dome, are lifted with a heavy load crane into the reactor building. With this concept, the construction activities on the inner containment wall are only five times disrupted by the welding and coating of the circumferential weld (approx. 25 calendar days). In comparison with the common known erection concept of welding of liner shells in situ, at least 20 weeks are saved on the schedule. An integrated concept from planning, manufacturing and erection of this large component has been implemented. It could be demonstrated that within the given time frame, with the required quality and within the required tolerances the containment liner for the Nuclear Power Plant can be delivered to the Client. (orig.)

On the Global Ship Hull Bending Energy in Ship Collisions

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Li, Y.

2004-01-01

During ship collisions part of the kinetic energy of the involved vessels prior to contact is absorbed as energy dissipated by crushing of the hull structures, by friction and by elastic energy. The purpose of this report is to present an estimate of the elastic energy that can be stored in elastic...... hull vibrations during a ship collision. When a ship side is strengthened in order to improve the crashworthiness it has been argued in the scientific literature that a non trivial part of the energy released for structural deformation during the collision can be absorbed as elastic energy in global...... ship hull vibrations, such that with strong ship sides less energy has to be spent in crushing of the striking ship bow and/or the struck ship side. In normal ship-ship collision analyses both the striking and struck ship are usually considered as rigid bodies where structural crushing is confined...

KINEMATIC ANALYSES OF THE GOLF SWING HUB PATH AND ITS ROLE IN GOLFER/CLUB KINETIC TRANSFERS

Directory of Open Access Journals (Sweden)

Steven M. Nesbit

2009-06-01

Full Text Available This study analyzed the fundamental geometric and kinematic characteristics of the swing hub path of the golf shot for four diverse subjects. In addition, the role of the hub path geometry in transferring the kinetic quantities from the golfer to the club were investigated. The hub path was found to have a complex geometry with significantly changing radii, and a constantly moving center-of-curvature during the downswing for all subjects. While the size and shape of the hub path differed considerably among the subjects, a three phase radius-based pattern was revealed that aligned with distinct stages of the downswing. Artificially controlling and optimizing the hub path of the better golfer in the group indicated that a non-circular hub path was superior to a constant radius path in minimizing the kinetic loading while generating the highest possible club head velocity. The shape and purpose of the hub path geometry appears to result from a complex combination of achieving equilibrium between the golfer and the club, and a purposeful configuring of the path to control the outward movement of the club while minimizing the kinetic loading on the golfer yet transferring the maximum kinetic quantities to the club. Describing the downswing relative to the hub path phasing is presented and was found to be informative since the phases align with significant swing, kinetic and kinematic markers. These findings challenge golf swing modeling methodologies which fix the center-of-curvature of the hub path thus constraining it to constant radius motion

Instability behavior of stiffened dome liners under construction condition

International Nuclear Information System (INIS)

Jefts, A.R.; Guha-Majumdar, S.; Wanchoo, M.K.

1977-01-01

The purpose of this paper is to present techniques related to stability analysis, design concepts and behavior of dome liners. Various stiffening systems are examined from economy, schedule and constructablity point of view. The various failure modes can be classified as either buckling due to local instability or to an overall instability of the shell. Local instability may occur due to buckling of liner panel between a pair of rings and stringers or torsional and lateral buckling of the stiffeners. Methods are developed for proportioning stiffening system to preclude local buckling. Overall stability is a function of concrete pour height and thickness, loading distribution, time elapse between successive placements, rate of concrete placement, arrangement of stiffeners and other external supports. A computer program based on system energy minimization is used to study the overall instability of stiffened domes. Modelling techniques, effect of temperature and lack of bond, and their influence on results are discussed. Results for a self-standing stiffened hemispherical dome are presented in the form of mode shapes and buckling loads. Based on the results, a pouring scheme is recommended for an economical stiffening system. Recommendations are made to select the stiffening system and predict the buckling loads for preliminary analysis and design of the dome liner. Existing methods and code provisions related to tolerance, design criteria etc. are examined and recommendations made from practical considerations

Abnormal hubs of white matter networks in the frontal-parieto circuit contribute to depression discrimination via pattern classification.

Science.gov (United States)

Qin, Jiaolong; Wei, Maobin; Liu, Haiyan; Chen, Jianhuai; Yan, Rui; Hua, Lingling; Zhao, Ke; Yao, Zhijian; Lu, Qing

2014-12-01

Previous studies had explored the diagnostic and prognostic value of the structural neuroimaging data of MDD and treated the whole brain voxels, the fractional anisotropy and the structural connectivity as classification features. To our best knowledge, no study examined the potential diagnostic value of the hubs of anatomical brain networks in MDD. The purpose of the current study was to provide an exploratory examination of the potential diagnostic and prognostic values of hubs of white matter brain networks in MDD discrimination and the corresponding impaired hub pattern via a multi-pattern analysis. We constructed white matter brain networks from 29 depressions and 30 healthy controls based on diffusion tensor imaging data, calculated nodal measures and identified hubs. Using these measures as features, two types of feature architectures were established, one only included hubs (HUB) and the other contained both hubs and non hubs. The support vector machine classifiers with Gaussian radial basis kernel were used after the feature selection. Moreover, the relative contribution of the features was estimated by means of the consensus features. Our results presented that the hubs (including the bilateral dorsolateral part of superior frontal gyrus, the left middle frontal gyrus, the bilateral middle temporal gyrus, and the bilateral inferior temporal gyrus) played an important role in distinguishing the depressions from healthy controls with the best accuracy of 83.05%. Moreover, most of the HUB consensus features located in the frontal-parieto circuit. These findings provided evidence that the hubs could be served as valuable potential diagnostic measure for MDD, and the hub-concentrated lesion distribution of MDD was primarily anchored within the frontal-parieto circuit. Copyright © 2014 Elsevier Inc. All rights reserved.

TYPE PROJECTS HUB - AN INTERNATIONAL MODEL OF DEVELOPMENT OF THE ENTREPRENEURIAL ENVIRONMENT

Directory of Open Access Journals (Sweden)

Rozalia Nistor

2014-06-01

Full Text Available Impact Hub is a global network of local spaces and communities designed to facilitate sustainable impact through collaboration. Local Impact Hubs are autonomous companies that offer co-working spaces, programming, events platforms, and communities of individuals and organizations with ideas to build a better world. Hub was established in 2005 in London with the aim of creating a space dedicated to inspire, connect and enable people to achieve a sustainable entrepreneurial idea. The idea was simple: There are a lot of people with good ideas for a "better world". What seem to be missing are places to help these people to move from intent to action and to find like-minded for a greater impact. In Romania about four years ago, first opened in Bucharest office space hubs in Romania (for entrepreneurs in technology and business where teams from different companies could collaborate. The idea to open a hub in Bucharest focused on social innovation and entrepreneurship appeared some time ago in the context in which part of the team now has worked since 2010 at the initiation and growth of a community to support social entrepreneurship. In all this diversity, there is a common mission: “we can create if we put all our innovation capacity in the common goal to create a positive impact through our work?”

Disrupted nodal and hub organization account for brain network abnormalities in Parkinson’s disease

Directory of Open Access Journals (Sweden)

Yuko Koshimori

2016-11-01

Full Text Available The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson’s disease. This study aimed to investigate functional changes in sensorimotor and cognitive networks in parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the healthy control and patient groups. We found nodal and hub changes in patients compared with healthy controls, including the right pre-supplementary motor area, left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex, and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e. right pre-supplementary motor area and right mid-insula displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral dorsolateral prefrontal cortex possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of Parkinson’s disease.

Analysis and Modeling of Ground Operations at Hub Airports

Science.gov (United States)

Atkins, Stephen (Technical Monitor); Andersson, Kari; Carr, Francis; Feron, Eric; Hall, William D.

2000-01-01

Building simple and accurate models of hub airports can considerably help one understand airport dynamics, and may provide quantitative estimates of operational airport improvements. In this paper, three models are proposed to capture the dynamics of busy hub airport operations. Two simple queuing models are introduced to capture the taxi-out and taxi-in processes. An integer programming model aimed at representing airline decision-making attempts to capture the dynamics of the aircraft turnaround process. These models can be applied for predictive purposes. They may also be used to evaluate control strategies for improving overall airport efficiency.

The impact of different types of textile liners used in protective footwear on the subjective sensations of firefighters.