76 FR 11216 - Inland Waterways Users Board

Science.gov (United States)

2011-03-01

... DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Inland Waterways Users Board AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD. ACTION: Notice of open meeting... is made of the forthcoming meeting. Name of Committee: Inland Waterways Users Board (Board). Date...

78 FR 72070 - Inland Waterways Users Board

Science.gov (United States)

2013-12-02

... DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Inland Waterways Users Board AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD. ACTION: Notice of open meeting... is made of the forthcoming meeting. Name of Committee: Inland Waterways Users Board (Board). Date...

77 FR 69447 - Inland Waterways Users Board

Science.gov (United States)

2012-11-19

... DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Inland Waterways Users Board AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD. ACTION: Notice of open meeting... is made of the forthcoming meeting. Name of Committee: Inland Waterways Users Board (Board). Date...

77 FR 22769 - Amendment to the Inland Waterways Users Board

Science.gov (United States)

2012-04-17

... DEPARTMENT OF DEFENSE Office of the Secretary Amendment to the Inland Waterways Users Board AGENCY... charter for the Inland Waterways Users Board (hereafter referred to as ``the Board''). The Board is... shall invite primary commercial users and shippers of the inland and intracoastal waterways to serve on...

Reclamation of abandoned mined lands along th Upper Illinois Waterway using dredged material

Energy Technology Data Exchange (ETDEWEB)

Van Luik, A; Harrison, W

1982-01-01

Sediments were sampled and characterized from 28 actual or proposed maintenance-dredging locations in the Upper Illinois Waterway, that is, the Calumet-Sag Channel, the Des Plaines River downstream of its confluence with the Calumet-Sag Channel, and the Illinois River from the confluence of the Kankakee and Des Plaines rivers to Havana, Illinois. Sufficient data on chemical constituents and physical sediments were obtained to allow the classification of these sediments by currently applicable criteria of the Illinois Environmental Protection Agency for the identification of hazardous, persistent, and potentially hazardous wastes. By these criteria, the potential dredged materials studied were not hazardous, persistent, or potentially hazardous; they are a suitable topsoil/ reclamation medium. A study of problem abandoned surface-mined land sites (problem lands are defined as being acidic and/or sparsely vegetated) along the Illinois River showed that three sites were particularly well suited to the needs of the Corps of Engineers (COE) for a dredged material disposal/reclamation site. Thes sites were a pair of municipally owned sites in Morris, Illinois, and a small corporately owned site east of Ottawa, Illinois, and adjacent to the Illinois River. Other sites were also ranked as to suitability for COE involvement in their reclamation. Reclamation disposal was found to be an economically competitive alternative to near-source confined disposal for Upper Illinois Waterway dredged material.

75 FR 66306 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR

Science.gov (United States)

2010-10-28

...-AA09 Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR AGENCY: Coast Guard, DHS... Arkansas Waterway at Mile 119.6 at Little Rock, Arkansas. Vessel operators shall contact the remote... Drawbridge Operation Regulation; Arkansas Waterway, Little [[Page 66307

77 FR 35903 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

Science.gov (United States)

2012-06-15

... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety... Intracoastal Waterway, mile 226, at Emerald Isle, North Carolina. [[Page 35904

77 FR 44463 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

Science.gov (United States)

2012-07-30

... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety zone is... Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle, North Carolina. The safety...

77 FR 57063 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

Science.gov (United States)

2012-09-17

... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety... NC 58 Fixed Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle, North...

77 FR 64906 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

Science.gov (United States)

2012-10-24

... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety... NC 58 Fixed Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle, North...

Navigated Waterways of Louisiana, Geographic NAD83, LOSCO (1999) [navigated_waterways_LOSCO_1999

Data.gov (United States)

Louisiana Geographic Information Center — This is a line dataset of navigated waterways fitting the LOSCO definition: it has been traveled by vessels transporting 10,000 gallons of oil or fuel as determined...

Research note: Mapping spatial patterns in sewer age, material, and proximity to surface waterways to infer sewer leakage hotspots

Science.gov (United States)

Hopkins, Kristina G.; Bain, Daniel J.

2018-01-01

Identifying areas where deteriorating sewer infrastructure is in close proximity to surface waterways is needed to map likely connections between sewers and streams. We present a method to estimate sewer installation year and deterioration status using historical maps of the sewer network, parcel-scale property assessment data, and pipe material. Areas where streams were likely buried into the sewer system were mapped by intersecting the historical stream network derived from a 10-m resolution digital elevation model with sewer pipe locations. Potential sewer leakage hotspots were mapped by identifying where aging sewer pipes are in close proximity (50-m) to surface waterways. Results from Pittsburgh, Pennsylvania (USA), indicated 41% of the historical stream length was lost or buried and the potential interface between sewers and streams is great. The co-location of aging sewer infrastructure (>75 years old) near stream channels suggests that 42% of existing streams are located in areas with a high potential for sewer leakage if sewer infrastructure fails. Mapping the sewer-stream interface provides an approach to better understand areas were failing sewers may contribute a disproportional amount of nutrients and other pathogens to surface waterways.

Inland Waterway Environmental Safety

Science.gov (United States)

Reshnyak, Valery; Sokolov, Sergey; Nyrkov, Anatoliy; Budnik, Vlad

2018-05-01

The article presents the results of development of the main components of the environmental safety when operating vessels on inland waterways, which include strategy selection ensuring the environmental safety of vessels, the selection and justification of a complex of environmental technical means, activities to ensure operation of vessels taking into account the environmental technical means. Measures to ensure environmental safety are developed on the basis of the principles aimed at ensuring environmental safety of vessels. They include the development of strategies for the use of environmental protection equipment, which are determined by the conditions for wastewater treatment of purified sewage and oily bilge water as well as technical characteristics of the vessels, the introduction of the process of the out-of-the-vessel processing of ship pollution as a technology for their movement. This must take into account the operating conditions of vessels on different sections of waterways. An algorithm of actions aimed at ensuring ecological safety of operated vessels is proposed.

Management of a Complex Open Channel Network During Flood Events

Science.gov (United States)

Franchini, M.; Valiani, A.; Schippa, L.; Mascellani, G.

2003-04-01

Most part of the area around Ferrara (Italy) is below the mean sea level and an extensive drainage system combined with several pump stations allows the use of this area for both urban development and industrial and agricultural activities. The three main channels of this hydraulic system constitute the Ferrara Inland Waterway (total length approximately 70 km), which connects the Po river near Ferrara to the sea. Because of the level difference between the upstream and dowstream ends of the waterway, three locks are located along it, each of them combined with a set of gates to control the water levels. During rainfall events, most of the water of the basin flows into the waterway and heavy precipitations sometimes cause flooding in several areas. This is due to the insufficiency of the channel network dimensions and an inadequate manual operation of the gates. This study presents a hydrological-hydraulic model for the entire Ferrara basin and a system of rules in order to operate the gates. In particular, their opening is designed to be regulated in real time by monitoring the water level in several sections along the channels. Besides flood peak attenuation, this operation strategy contributes also to the maintenance of a constant water level for irrigation and fluvial navigation during the dry periods. With reference to the flood event of May 1996, it is shown that this floodgate operation policy, unlike that which was actually adopted during that event, would lead to a significant flood peak attenuation, avoiding flooding in the area upstream of Ferrara.

33 CFR 162.260 - Channel leading to San Juan Harbor, P.R.; use, administration, and navigation.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Channel leading to San Juan Harbor, P.R.; use, administration, and navigation. 162.260 Section 162.260 Navigation and Navigable... WATERWAYS NAVIGATION REGULATIONS § 162.260 Channel leading to San Juan Harbor, P.R.; use, administration...

Significance of Waterway Navigation Positioning Systems On Ship's Manoeuvring Safety

Science.gov (United States)

Galor, W.

The main goal of navigation is to lead the ship to the point of destination safety and efficiently. Various factors may affect ship realisating this process. The ship movement on waterway are mainly limited by water area dimensions (surface and depth). These limitations cause the requirement to realise the proper of ship movement trajectory. In case when this re requirement cant't fulfil then marine accident may happend. This fact is unwanted event caused losses of human health and life, damage or loss of cargo and ship, pollution of natural environment, damage of port structures or blocking the port of its ports and lost of salvage operation. These losses in same cases can be catas- trophical especially while e.i. crude oil spilling could be place. To realise of safety navigation process is needed to embrace the ship's movement trajectory by waterways area. The ship's trajectory is described by manoeuvring lane as a surface of water area which is require to realise of safety ship movement. Many conditions affect to ship manoeuvring line. The main are following: positioning accuracy, ship's manoeuvring features and phenomena's of shore and ship's bulk common affecting. The accuracy of positioning system is most important. This system depends on coast navigation mark- ing which can range many kinds of technical realisation. Mainly used systems based on lights (line), radionavigation (local system or GPS, DGPS), or radars. If accuracy of positiong is higer, then safety of navigation is growing. This article presents these problems exemplifying with approaching channel to ports situated on West Pomera- nian water region.

From microbes to water districts: Linking observations across scales to uncover the implications of riparian and channel management on water quality in an irrigated agricultural landscape

Science.gov (United States)

Webster, A.; Cadenasso, M. L.

2016-12-01

Interactions among runoff, riparian and stream ecosystems, and water quality remain uncertain in many settings, particularly those heavily impacted by human activities. For example, waterways in the irrigated agricultural landscape of California's Central Valley are seasonally disconnected from groundwater tables and are extensively modified by infrastructure and management. These conditions make the impact of riparian and channel management difficult to predict across scales, which hinders efforts to promote best management practices to improve water quality. We seek to link observations across catchment, reach, and patch scales to understand patterns of nitrate and turbidity in waterways draining irrigated cropland. Data was collected on 80 reaches spanning two water management districts. At the catchment scale, water districts implemented waterway and riparian management differently: one water district had a decentralized approach, allowing individual land owners to manage their waterway channels and banks, while the other had a centralized approach, in which land owners defer management to a district-run program. At the reach scale, riparian and waterway vegetation, geomorphic complexity, and flow conditions were quantified. Reach-scale management such as riparian planting projects and channel dredging frequency were also considered. At the patch scale, denitrification potential and organic matter were measured in riparian toe-slope soils and channel sediments, along with associated vegetation and geomorphic features. All factors were tested for their ability to predict water quality using generalized linear mixed effects models and the consistency of predictors within and across scales was evaluated. A hierarchy of predictors emerges: catchment-scale management regimes predict reach-scale geomorphic and vegetation complexity, which in turn predicts sediment denitrification potential - the patch-scale factor most associated with low nitrate. Similarly

Bank erosion processes in waterways

NARCIS (Netherlands)

Duro, G.; Uijttewaal, W.S.J.; Kleinhans, M; Crosato, A.

2017-01-01

Waterways serve for several functions besides  transporting goods and people. The ecological  importance of navigable rivers has taken much  attention during recent decades bringing efforts  to improve these natural corridors for fauna and  flora (Boeters et al.,

Margins of the law pertaining to water supplies and waterways

International Nuclear Information System (INIS)

Bickel, C.

1981-01-01

The author examines legal questions coming from points of contact of the law pertaining to water supplies and waterways on the one hand with the Waste Management Law, the Atomic Energy Law and Criminal Law on the other hand. He tries to find ways for solving the practical problems which arise with the execution of the law pertaining to water supplies and waterways. (HSCH) [de

78 FR 69803 - Drawbridge Operation Regulations; Gulf Intracoastal Waterway, Venice, FL

Science.gov (United States)

2013-11-21

...-AA09 Drawbridge Operation Regulations; Gulf Intracoastal Waterway, Venice, FL AGENCY: Coast Guard, DHS... that governs the Hatchett Creek (US-41) Twin Bridges, Gulf Intracoastal Waterway mile 56.9, Venice, FL... mile 56.9 at Venice, FL as listed in Sec. 117.287(b), provides the draw of the Hatchett Creek (US-41...

75 FR 30750 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR

Science.gov (United States)

2010-06-02

...-AA09 Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR AGENCY: Coast Guard, DHS... procedures on the Baring Cross Railroad Drawbridge across the Arkansas Waterway at mile 119.6 at Little Rock....123(b) state that the draw of the Baring Cross Railroad Drawbridge, mile 119.6, at Little Rock, AR is...

33 CFR 167.405 - Off San Francisco: Main ship channel.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Off San Francisco: Main ship channel. 167.405 Section 167.405 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas...

OPG waterways public safety program

Energy Technology Data Exchange (ETDEWEB)

Bennett, T [Ontario Power Generation Inc., Niagara Falls, ON (Canada)

2009-07-01

Ontario Power Generation (OPG) has 64 hydroelectric generating stations, 241 dams, and 109 dams in Ontario's registry with the International Commission on Large Dams (ICOLD). In 1986, it launched a formal dam safety program. This presentation addressed the importance of public safety around dams. The safety measures are timely because of increasing public interaction around dams; the public's unawareness of hazards; public interest in extreme sports; easier access by recreational vehicles; the perceived right of public to access sites; and the remote operation of hydroelectric stations. The presentation outlined the OPG managed system approach, with particular reference to governance; principles; standards and procedures; and aspects of implementation. Specific guidelines and governing documents for public safety around dams were identified, including guidelines for public safety of waterways; booms and buoys; audible warning devices and lights; public safety signage; fencing and barricades; and risk assessment for public safety around waterways. The presentation concluded with a discussion of audits and management reviews to determine if safety objectives and targets have been met. figs.

The operational efficiency of waterway transport of forest chips on Finland's Lake Saimaa

Energy Technology Data Exchange (ETDEWEB)

Karttunen, K.; Ranta, T. [Lappeenranta Univ. of Technology, LUT Savo Sustainable Technologies, Mikkeli (Finland); Vaatainen, K.; Asikainen, A. [The Finnish Forest Research Inst., Joensuu (Finland)], E-mail: kalle.karttunen@lut.fi

2012-11-01

New and cost-efficient methods for use in supply chains for energy wood should be found, to reach the targets of the renewable energy utilisation set by the European Union. The long-distance waterway transportation of forest fuels should be thoroughly investigated, especially in areas where the transport distance is long and waterways could provide a feasible method of conveying forest fuel. In comparison to transport of forest chips by truck, barge-based waterway transport shows a competitive advantage due to the larger loads and higher bulk density of chips it allows. The cost-efficiency of waterway transportation operations related to forest chips in Finland's Lake Saimaa region was studied using practical demonstrations and discrete-event simulation. The varying demand for fuel wood in three separate bio-power plants on the Saimaa lakeside (near the cities of Varkaus, Mikkeli, and Savonlinna) was addressed in several barge transportation scenarios. Finally, the economy of barge transportation was compared to the economy of truck transportation as a function of transportation distance and in terms of the annual performance of the transportation methods examined. The waterway supply chain of forest chips was cost-competitive to road transport by truck after 100-150 km. According to the simulation study, the most economical waterway transport options were based on fixed barge system and shift-independent harbor logistics where loading and unloading of barges were carried-out with a wheeled loader and a belt conveyor. Total supply chain costs including the best waterway logistics from road side storage to power plant ranged from 10.75 euros to 11.64 euros/MWh in distances of 100-150 km by waterways. The energy-density of forest chips in the barge load was found to be, on average, 25% higher than that in truck hauling, because of the better compaction of chips. Waterway transport is a viable option for long-distance transportation of forest chips in Eastern

77 FR 69562 - Drawbridge Operation Regulation; Thea Foss Waterway Previously Known as City Waterway, Tacoma, WA

Science.gov (United States)

2012-11-20

... shape in the ``Actions'' column. If you submit your comments by mail or hand delivery, submit them in an... unique features of the Murray Morgan Bridge is its height above the waterway providing 60 feet of... bridge openings are for locally moored and operated recreational sailboats with mast heights over 60 feet...

Forstering cooperation in inland waterway networks : a gaming and simulation approach (chapter 23)

NARCIS (Netherlands)

Veenstra, A.W.; Meijeren, van J.; Harmsen, J.M.A.; Verbraeck, A.; Negenborn, R.R.; Ocampa-Martinez, C.

2015-01-01

Inland waterway transport is an important economic activity in the Netherlands and in Europe. Especially in the hinterland transport of containers, inland shipping is expected to form the backbone of a multimodal transport system. To support and strengthen the inland waterway industry in the

Relationships Between Perceived Coastal Waterway Condition and Social Aspects of Quality of Life

Directory of Open Access Journals (Sweden)

Melanie E. Cox

2006-06-01

Full Text Available Previous research has shown that the presence of natural areas is beneficial to human well-being. However, to date there have been few published studies of the effects that the condition of natural areas have on well-being. We hypothesize that coastal waterways that are perceived to be in better condition are visited more often by local residents, and as a result, residents will develop a stronger sense of place and stronger social relations with other residents, which will in turn lead to a higher quality of life. A survey was conducted to test this hypothesis in two coastal regions in Queensland, Australia. A weak relationship was found between perceived coastal quality and the number of recreational visits. In both study areas, frequency of visits to coastal waterways was significantly related to quality of life through an increased sense of place and social contacts. In the Douglas region, sense of place and social capital were closely related, and social capital was also related to quality of life. In both study areas, residents were most likely to visit waterways that were located in close proximity to their residence, suggesting that management of all waterways is essential for human well-being, and that benefits to humans will result from rehabilitating degraded waterways.

Detection of multi-drug resistant Escherichia coli in the urban waterways of Milwaukee, WI

Directory of Open Access Journals (Sweden)

Anthony D. Kappell

2015-04-01

Full Text Available Urban waterways represent a natural reservoir of antibiotic resistance which may provide a source of transferable genetic elements to human commensal bacteria and pathogens. The objective of this study was to evaluate antibiotic resistance of Escherichia coli isolated from the urban waterways of Milwaukee, WI compared to those from Milwaukee sewage and a clinical setting in Milwaukee. Antibiotics covering 10 different families were utilized to determine the phenotypic antibiotic resistance for all 259 E. coli isolates. All obtained isolates were determined to be multi-drug resistant. The E. coli isolates were also screened for the presence of the genetic determinants of resistance including ermB (macrolide resistance, tet(M (tetracycline resistance, and β-lactamases (blaOXA, blaSHV, and blaPSE. E. coli from urban waterways showed a greater incidence of antibiotic resistance to 8 of 17 antibiotics tested compared to human derived sources. These E. coli isolates also demonstrated a greater incidence of resistance to higher numbers of antibiotics compared to the human derived isolates. The urban waterways demonstrated a greater abundance of isolates with co-occurrence of antibiotic resistance than human derived sources. When screened for 5 different antibiotic resistance genes conferring macrolide, tetracycline, and β-lactam resistance, clinical E. coli isolates were more likely to harbor ermB and blaOXA than isolates from urban waterway. These results indicate that Milwaukee’s urban waterways may select for a greater incidence of multiple antibiotic resistance organisms and likely harbor a different antibiotic resistance gene pool than clinical sources. The implications of this study are significant to understanding the presence of resistance in urban freshwater environments by supporting the idea that sediment from urban waterways serves as a reservoir of antibiotic resistance.

Conditions of using floating cranes for lifting sunken objects on inland waterways

OpenAIRE

Slobodan M. Radojević

2012-01-01

This paper presents the conditions for using floating cranes for lifting sunken vessels and other objects on inland waterways. Basic technical data are given together with technical details for the usage of floa ting cranes for lifting sunken objects. The paper points to the importance of lifting sunken objects and their removal from inland waterways in the Republic of Serbia.

Conditions of using floating cranes for lifting sunken objects on inland waterways

Directory of Open Access Journals (Sweden)

Slobodan M. Radojević

2012-04-01

Full Text Available This paper presents the conditions for using floating cranes for lifting sunken vessels and other objects on inland waterways. Basic technical data are given together with technical details for the usage of floa ting cranes for lifting sunken objects. The paper points to the importance of lifting sunken objects and their removal from inland waterways in the Republic of Serbia.

78 FR 59339 - Intracoastal Waterway Route “Magenta Line” on NOAA Nautical Charts

Science.gov (United States)

2013-09-26

... waterways have been based principally on surveys made from 60 to 80 years ago and, necessarily, are obsolete... found where the charted Intracoastal Waterway Route (``magenta line'') passes on the wrong side of aids... specifically seeks comments regarding: 1. How do you currently access the magenta line? On paper nautical...

Investigating driver willingness to drive through flooded waterways.

Science.gov (United States)

Pearson, Marti; Hamilton, Kyra

2014-11-01

Approximately 40% of all drowning deaths involve a motor vehicle. Regardless of its significance as a cause of flood-related mortality, there is continued prevalence of driving through flooded waterways in Australia and worldwide. We aimed to understand the motivational determinates of driving through flooded waterways in low and high-risk scenarios by utilizing an augmented theory of planned behaviour (TPB) with behavioural willingness as the outcome variable as well as the influence of additional predictors; namely perceived risk and past behaviour. Participants (n=174; Mage=27.43, SD=10.76) answered standard TPB-based questions in regards to attitudes, subjective norm, and perceived behavioural control (PBC), as well as additional variables of perceived risk (i.e., perceived susceptibility and perceived severity) and past behaviour. Support was found for the augmented TPB as attitude, subjective norm, and PBC predicted behavioural willingness. Support was also found for perceived severity in the high-risk but not the low-risk scenario. No support was found for perceived susceptibility. Past behaviour emerged as a significant predictor of willingness in the low and high-risk scenario. The findings provide support for an augmented TPB in understanding individuals' willingness to drive through flooded waterways, suggesting that a multi-strategy approach may be critical in attempts to reduce the incidence of such risky driving behaviour. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of Multi-Scale Digital Elevation Models for Defining Waterways and Catchments Over Large Areas

Science.gov (United States)

Harris, B.; McDougall, K.; Barry, M.

2012-07-01

Digital Elevation Models (DEMs) allow for the efficient and consistent creation of waterways and catchment boundaries over large areas. Studies of waterway delineation from DEMs are usually undertaken over small or single catchment areas due to the nature of the problems being investigated. Improvements in Geographic Information Systems (GIS) techniques, software, hardware and data allow for analysis of larger data sets and also facilitate a consistent tool for the creation and analysis of waterways over extensive areas. However, rarely are they developed over large regional areas because of the lack of available raw data sets and the amount of work required to create the underlying DEMs. This paper examines definition of waterways and catchments over an area of approximately 25,000 km2 to establish the optimal DEM scale required for waterway delineation over large regional projects. The comparative study analysed multi-scale DEMs over two test areas (Wivenhoe catchment, 543 km2 and a detailed 13 km2 within the Wivenhoe catchment) including various data types, scales, quality, and variable catchment input parameters. Historic and available DEM data was compared to high resolution Lidar based DEMs to assess variations in the formation of stream networks. The results identified that, particularly in areas of high elevation change, DEMs at 20 m cell size created from broad scale 1:25,000 data (combined with more detailed data or manual delineation in flat areas) are adequate for the creation of waterways and catchments at a regional scale.

78 FR 26799 - Waterway Suitability Assessment for Expansion of Liquefied Gas Terminals; Beaumont, TX

Science.gov (United States)

2013-05-08

... Partnership LP has submitted a Letter of Intent and a Waterway Suitability Assessment to the Coast Guard.... Martin Operating Partnership's Stanolind Cut Terminal in Beaumont, Texas submitted an LOI on January 25... the physical nature of the affected waterway and issues of safety and security associated with LNG or...

Model-Based Design and Formal Verification Processes for Automated Waterway System Operations

Directory of Open Access Journals (Sweden)

Leonard Petnga

2016-06-01

Full Text Available Waterway and canal systems are particularly cost effective in the transport of bulk and containerized goods to support global trade. Yet, despite these benefits, they are among the most under-appreciated forms of transportation engineering systems. Looking ahead, the long-term view is not rosy. Failures, delays, incidents and accidents in aging waterway systems are doing little to attract the technical and economic assistance required for modernization and sustainability. In a step toward overcoming these challenges, this paper argues that programs for waterway and canal modernization and sustainability can benefit significantly from system thinking, supported by systems engineering techniques. We propose a multi-level multi-stage methodology for the model-based design, simulation and formal verification of automated waterway system operations. At the front-end of development, semi-formal modeling techniques are employed for the representation of project goals and scenarios, requirements and high-level models of behavior and structure. To assure the accuracy of engineering predictions and the correctness of operations, formal modeling techniques are used for the performance assessment and the formal verification of the correctness of functionality. The essential features of this methodology are highlighted in a case study examination of ship and lock-system behaviors in a two-stage lock system.

COMPARISON OF MULTI-SCALE DIGITAL ELEVATION MODELS FOR DEFINING WATERWAYS AND CATCHMENTS OVER LARGE AREAS

Directory of Open Access Journals (Sweden)

B. Harris

2012-07-01

Full Text Available Digital Elevation Models (DEMs allow for the efficient and consistent creation of waterways and catchment boundaries over large areas. Studies of waterway delineation from DEMs are usually undertaken over small or single catchment areas due to the nature of the problems being investigated. Improvements in Geographic Information Systems (GIS techniques, software, hardware and data allow for analysis of larger data sets and also facilitate a consistent tool for the creation and analysis of waterways over extensive areas. However, rarely are they developed over large regional areas because of the lack of available raw data sets and the amount of work required to create the underlying DEMs. This paper examines definition of waterways and catchments over an area of approximately 25,000 km2 to establish the optimal DEM scale required for waterway delineation over large regional projects. The comparative study analysed multi-scale DEMs over two test areas (Wivenhoe catchment, 543 km2 and a detailed 13 km2 within the Wivenhoe catchment including various data types, scales, quality, and variable catchment input parameters. Historic and available DEM data was compared to high resolution Lidar based DEMs to assess variations in the formation of stream networks. The results identified that, particularly in areas of high elevation change, DEMs at 20 m cell size created from broad scale 1:25,000 data (combined with more detailed data or manual delineation in flat areas are adequate for the creation of waterways and catchments at a regional scale.

Socio-cultural impacts of construction and regulation of the waterway of Oulujoki river

International Nuclear Information System (INIS)

Ruotsala, H.

1992-01-01

The purpose of study was to clarify the socio-cultural impacts of the regulation and construction of Oulujoki river on the everyday life of people. Changes in work and livelihood, living and living satisfaction, and leisure time and recreation are considered as variables. Quantitative and qualitative methods were combined in the study. The principal study material is composed of answers to a questionnaire and of 109 thematic interviews on the topic. The hold of the study is phenomenological-hermeneutical, with the intention to interpret the matter from the viewpoint of the attitudes and requirements of the waterway users. The theoretical frame of reference was culture-ecological point of view and adaptive process. The emphasis of the study is on sociocultural adaptation. The attitude towards waterway construction and regulation was dependent on the background of the person interviewed. The attitude was considered e.g. by various interest groups and professional groups, such as farmers, inhabitants on the shore, recreation users, fishermen, municipal elected officials. Other important variables were age, family stage and sex. Big local differences in the attitudes could also be found. While prevailing values in society and peoples' modes of living are changing, also the attitude towards waterway and changes caused by waterway construction has changed in the region studied. The impacts on the sources of livelihood are minor for the moment, the impacts on living satisfaction and recreations are significant. While leisure time is increasing the recreation value of waterway increases, too. At the construction stage of the river, the economical and productional advantages took priority, and then no attention was paid to recreational use

Application of GIS tools in determining the navigability of waterways

Science.gov (United States)

Nadolny, Grzegorz; Rabant, Hubert; Szatten, Dawid

2017-11-01

This article presents the results of a research conducted on Lower Noteć river for the application of geographic information system (GIS) tools. The study consisted of longitudinal profile soundings of navigable route combined with statistical analysis of water levels. GIS software - ArcMap v. 10.0 was used to perform analysis of changes in waterway depth depending on hydrological conditions. A mileage of waterway sections was specified depending on whether they met or did not meet classification requirements in accordance with Polish law. The application of spatial data of Lower Noteć river developed for the purpose of the article is presented. Conducted analyses and obtained results demonstrate the importance of GIS tools in inland navigation studies.

77 FR 5398 - Safety Zone; Atlantic Intracoastal Waterway, Vicinity of Marine Corps Base, Camp Lejeune, NC

Science.gov (United States)

2012-02-03

...-AA00 Safety Zone; Atlantic Intracoastal Waterway, Vicinity of Marine Corps Base, Camp Lejeune, NC... zone on the Atlantic Intracoastal Waterway (AICW) adjacent to Marine Corps Base (MCB) Camp Lejeune..., Vicinity of Marine Corps Base, Camp Lejeune, NC in the Federal Register (77 FR 1431). We received no...

Predicted effects on ground water of construction of Divide Cut section, Tennessee-Tombigbee Waterway, northeastern Mississippi, using a digital model

Science.gov (United States)

McBride, Mark S.

1981-01-01

The Tennessee-Tombigbee Waterway, connecting the Tennessee River in northeastern Mississippi with the Gulf of Mexico, is currently (1980) under construction. The Divide Section, the northernmost 39 miles of the Waterway, will consist, from north to south, of (1) a dredged channel, (2) the Divide Cut, and (3) an artifical lake impounded by the Bay Springs Dam. In all three , water will be at Tennessee River level. A three-dimensional digital model covering 3,273 square miles was constructed to simulate ground-water flow in the Gordo and Eutaw Formations and the Coffee Sand in the vicinity of the Divide Section. The model was calibrated to preconstruction water levels, then used to simulate the effects of stresses imposed by the construction of the Divide Section. The model indicates that the system stabilizes after major changes in conditions within a few months. The Divide Cut acts as a drain, lowering water levels as much as 55 feet. Drawdowns of 5 feet occur as much as 8 miles from the Cut. The 80-foot-high Bay Springs Dam raises ground-water levels by 5 feet as far as 6 miles from its impoundment. Drawdown is not likely to affect public water supplies significantly, but probably will adversely affect a relatively small number of private wells. (USGS)

75 FR 5769 - Inland Waterways Users Board; Request for Nominations

Science.gov (United States)

2010-02-04

... ``various'' regions. For the purpose of selecting Board members, the waterways subjected to fuel taxes and... Products; (2) Coal and Coke; (3) Petroleum, Crude and Products; (4) Minerals, Ores, and Primary Metals and...

77 FR 47826 - Inland Waterways Users Board; Request for Nominations

Science.gov (United States)

2012-08-10

... the Board, the waterways subjected to fuel taxes and described in Public Law 95-502, as amended, have... United States. These categories are (1) Farm and Food Products; (2) Coal and Coke; (3) Petroleum, Crude...

PROPOSED GUIDELINES ON DEVELOPING THE OPTIMISATION MODEL FOR PASSAGE PLANNING IN INLAND WATERWAYS NAVIGATION

OpenAIRE

Ivančić, Paško; Kasum, Joško; Pavić, Ivica

2013-01-01

Road transport networks are overloaded by the increasing number of vehicles [1]. This has resulted in the redirection and the increasing intensity of navigation on rivers, canals and lakes. Transportation by inland waterways of the European Union (EU) represents a reliable, economical and environmentally friendly mode of transport. The latter has been recognized as a key form of transport in the European intermodal transport system. Inland waterways as part of the transport system play an imp...

76 FR 13422 - Lower Mississippi River Waterway Safety Advisory Committee; Vacancies

Science.gov (United States)

2011-03-11

... the Lower Mississippi River and its connecting navigable waterways, including the Gulf of Mexico. The... receive no salary, reimbursement of travel expenses, or other compensation from the Federal Government...

76 FR 60076 - Lower Mississippi River Waterway Safety Advisory Committee; Vacancies

Science.gov (United States)

2011-09-28

... navigable waterways, including the Gulf of Mexico. 1. Five members representing River Port Authorities... consecutive terms. All members serve at their own expense and receive no salary reimbursement of travel...

Conditions Of Safe Ship Operations And Sea Waterway Parameters Based On The Reconstruction Of Świnoujście-Szczecin Fairway

Directory of Open Access Journals (Sweden)

Gucma Stanisław

2015-09-01

Full Text Available This paper describes the state vector of safe ship operation on sea waterways. The author determines relationships between the state vector of safe ship operation and parameters of sea waterway system elements. These include three subsystems: area, navigation and traffic control. These relationships have been exemplified with the 68-kilometre Świnoujście-Szczecin fairway, presently under reconstruction. A systematic approach to sea waterway design is globally unique.

Computation Of The Residual Radionuclide Activity Within Three Natural Waterways At The Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Hiergesell, R. A.; Phifer, M. A.

2014-01-07

analysis data that had been collected for various SRS investigations, as well as the additional streambed and floodplain sampling and analysis data acquired more recently as part of the ongoing SRS IOU program, and associated specifically with the FMB, PB, and SC IOUs. Samples have been acquired along the waterways, within the stream channels themselves and in the adjacent floodplain zones. While Cs-137 is the most significant and abundant radionuclide associated with the SRS waterways, it is not the only radionuclide, hence work was conducted to evaluate all radionuclides present.

Development of a monthly to seasonal forecast framework tailored to inland waterway transport in central Europe

Science.gov (United States)

Meißner, Dennis; Klein, Bastian; Ionita, Monica

2017-12-01

Traditionally, navigation-related forecasts in central Europe cover short- to medium-range lead times linked to the travel times of vessels to pass the main waterway bottlenecks leaving the loading ports. Without doubt, this aspect is still essential for navigational users, but in light of the growing political intention to use the free capacity of the inland waterway transport in Europe, additional lead time supporting strategic decisions is more and more in demand. However, no such predictions offering extended lead times of several weeks up to several months currently exist for considerable parts of the European waterway network. This paper describes the set-up of a monthly to seasonal forecasting system for the German stretches of the international waterways of the Rhine, Danube and Elbe rivers. Two competitive forecast approaches have been implemented: the dynamical set-up forces a hydrological model with post-processed outputs from ECMWF general circulation model System 4, whereas the statistical approach is based on the empirical relationship (teleconnection) of global oceanic, climate and regional hydro-meteorological data with river flows. The performance of both forecast methods is evaluated in relation to the climatological forecast (ensemble of historical streamflow) and the well-known ensemble streamflow prediction approach (ESP, ensemble based on historical meteorology) using common performance indicators (correlation coefficient; mean absolute error, skill score; mean squared error, skill score; and continuous ranked probability, skill score) and an impact-based evaluation quantifying the potential economic gain. The following four key findings result from this study: (1) as former studies for other regions of central Europe indicate, the accuracy and/or skill of the meteorological forcing used has a larger effect than the quality of initial hydrological conditions for relevant stations along the German waterways. (2) Despite the predictive

U.S. Navigated Waterway Mile Marker Locations from USCOE source data, Geographic NAD83, LOSCO (2000) [river_mile_markers_USACE_1994

Data.gov (United States)

Louisiana Geographic Information Center — This is a point dataset representing 10,044 sequential mile positions of navigable inland waterways and the Gulf Intracoastal Waterway. These data were developed as...

The influence of hydrology and waterway distance on population structure of Chinook salmon Oncorhynchus tshawytscha in a large river.

Science.gov (United States)

Olsen, J B; Beacham, T D; Wetklo, M; Seeb, L W; Smith, C T; Flannery, B G; Wenburg, J K

2010-04-01

Adult Chinook salmon Oncorhynchus tshawytscha navigate in river systems using olfactory cues that may be influenced by hydrologic factors such as flow and the number, size and spatial distribution of tributaries. Thus, river hydrology may influence both homing success and the level of straying (gene flow), which in turn influences population structure. In this study, two methods of multivariate analysis were used to examine the extent to which four indicators of hydrology and waterway distance explained population structure of O. tshawytscha in the Yukon River. A partial Mantel test showed that the indicators of hydrology were positively associated with broad-scale (Yukon basin) population structure, when controlling for the influence of waterway distance. Multivariate multiple regression showed that waterway distance, supplemented with the number and flow of major drainage basins, explained more variation in broad-scale population structure than any single indicator. At an intermediate spatial scale, indicators of hydrology did not appear to influence population structure after accounting for waterway distance. These results suggest that habitat changes in the Yukon River, which alter hydrology, may influence the basin-wide pattern of population structure in O. tshawytscha. Further research is warranted on the role of hydrology in concert with waterway distance in influencing population structure in Pacific salmon.

Order of 21 May 1979 on Transport of Radioactive Materials by Road or by Inland Waterway (Dangerous Goods 1979, No.5)

International Nuclear Information System (INIS)

1979-01-01

This Order lays down in connection with radioactive materials (class IVb) to be carried by road or inland waterway that Section 32 of the Order of 15 April 1945 approving the transport of dangerous goods by rail, land or inland waterway will come into force on 1 October 1980. The Order prescribes that drivers of land vehicles and on inland waterways, persons responsible on board must carry a certificate concerning their cargo in accordance with the above Section. (NEA) [fr

Modal-split effects of climate change: The effects of low water levels on the competitive position of inland waterway transport in the River Rhine area

NARCIS (Netherlands)

Jonkeren, O.E.; Jourquin, B.; Rietveld, P.

2011-01-01

Future climate change is expected to affect inland waterway transport in most main natural waterways in Europe. For the river Rhine it is expected that, in summer, more and longer periods with low water levels will occur. In periods of low water levels inland waterway vessels have to reduce their

DROUGHTS IN THE TIETÊ-PARANÁ WATERWAY: IMPACTS ON THE DIRECT, INDIRECT AND HIDDEN COSTS IN THE TRANSPORTATION OF SOYBEAN.

Directory of Open Access Journals (Sweden)

Rodrigo Carlo Toloi

2016-05-01

Full Text Available Brazil's agricultural economy is growing and increasing productivity. Therefore, it has required transportation systems with high load capacity and lower transportation costs. However, with the drought in the Southeast region of Brazil, the waterway Tietê-Paraná closed since May 2014 generating a loss of more than 30 million last year. Thus, this study investigates the impacts on direct, indirect and hidden costs resulting from this change of route for soy transport. The methodology consists of an exploratory, descriptive and bibliographic research that seeks to raise the main costs. The results show that failing to ensure the production of soybeans by the Tiete-Parana waterway and using the highway transportation costs for waterway users are increased by US$ 37,760,146.86.

Analysis Of Inland Waterway Transport For Container Shipping: Cikarang To Port Of TanjungPriok

Science.gov (United States)

Achmadi, T.; Nur, H. I.; Rahmadhon, L. R.

2018-03-01

Industry's development which is in the center of Cikarang's industrial estate causes a considerable increase from 7% to 13% of container's flow from and to Port of Tanjung Priok per year. Therefore, those obstacles rise the number of traffic congestion and transport cost. This research aims to analyze the potential alternative of transportation in order to transport containers at the route of Tanjung Priok to Cikarang utilizing Inland Waterways Transport through Cikarang Bekasi Laut (CBL) river. This research will be conducted by comparing component of total logistic cost that emerging caused by container trucks and vessels. Self Propelled Container Barge (SPCB) is a pointed alternative transportation in which it is used to transport containers through the waterways. The result of analysis obtained that the capacity of Cikarang Bekasi Laut river is 18,558 roundtrip per year. Furthermore, the collaboration of 3 SPCB operations, as well payload 32 TEUS can decrease the amount of road traffic congestion/density of Cikarang-Port of Tanjung Priok as much as 18.6%. The cost of containers shipping per unit transported by truck is IDR 2.2 Million per TEUs, whereas containers shipping transported by Inland Waterways cost only IDR 1.8 Million per TEUs.

75 FR 61094 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Beaufort, SC

Science.gov (United States)

2010-10-04

.... Highway 21, Sea Island Parkway Bridge at mile marker 536 over the Beaufort River (Atlantic Intracoastal... Bridge, which is across the Atlantic Intracoastal Waterway at mile 539.0 in Port Royal, South Carolina... Bridge, across the Beaufort River, Mile 536.0 at Beaufort. The draw shall operate as follows: (1) On...

A history of trade routes and water-level regulation on waterways in Voyageurs National Park, Minnesota, USA

Science.gov (United States)

Christensen, Victoria G.; LaBounty, Andrew E.

2018-01-01

Unlike most national parks, main access to Voyageurs National Park is by boat. This remote system of interconnected waterways along the USA-Canada border was an important transportation route for thousands of years of American Indian occupation, leading up to and including the trade route of the voyageurs, or French-Canadian fur traders from around 1680 to 1870. The Ojibwe people collaborated with the voyageurs and the two cultures developed a trade network that continued to rely on these waterways. By the mid-1800s, European fashion changed, and the fur trade dwindled while the Ojibwe remained tied to the land and waters. The complexity of the waterways increased with the installation of dams on two of the natural lakes in the early 1900s. Modern water levels have affected—and in some cases destabilized—vulnerable landforms within the past century. The knowledge of these effects can be used by resource managers to weigh the consequences of hydrologic manipulation in Voyageurs National Park.

On the Waterway Staff Training Management and Innovation%试论航道员工培训管理与创新

Institute of Scientific and Technical Information of China (English)

镇卫兵

2014-01-01

近年来我国航道事业随着社会经济的快速发展越来越被重视，航道作为水路运输的重要组成部分，其管理状况对水运发展起着直接影响作用。本文通过对航道现行体制与管理情况探讨，结合员工培训管理与创新分析，提出加强航道管理水平的策略，以实现水运交通事业快速持续健康发展的目标。%In recent years, with the rapid development of social economy, waterway business in China has been paid more and more attention. As an important part of water transportation, waterway's management conditions have a direct impact on water transportation development. Through the discussion of current system and management conditions of waterway, combined with analysis of employee training management and innovation, this article puts forward the strategies to strengthen the waterway management level, in order to achieve the goal of rapid, sustainable and healthy development of waterway transportation business.

Efficacy of commercial algaecides to manage species of Phytophthora in suburban waterways

Science.gov (United States)

G. Curtis Colburn; Steven N. Jeffers

2010-01-01

Many commercial algaecides contain copper compounds as active ingredients. Phytophthora spp. and other oomycetes are known to be sensitive to copper-based fungicides. Therefore, algaecides registered to manage algae in natural waterways and irrigation waters also might be effective for mitigating or even eradicating Phytophthora ...

78 FR 66266 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway (AIWW), Chesapeake, VA

Science.gov (United States)

2013-11-05

... deviation from the operating schedule that governs the I64 Bridge across the Atlantic Intracoastal Waterway... deviation, call or email Mrs. Kashanda Booker, Bridge Administration Branch Fifth District, Coast Guard... maintenance of the moveable spans on the structure. The current operating schedule for the drawbridge is set...

OPG - Waterways public safety program

Energy Technology Data Exchange (ETDEWEB)

Bennett, Tony [Ontario Power Generation (Canada)

2011-07-01

Ontario Power Generation (OPG) operates 65 hydroelectric generating stations in Ontario and has 241 dams. Security around dams is an important matter to minimize exposure of the public to hazards and to prevent an uncontrolled release of water and also to be prepared in case of failure. The purpose of this presentation is to describe the waterways public safety program developed by OPG in association with the Ontario Waterpower Associattion, the Canadian Dam Association and the Ontario Ministry of Natural Resoruces. This program takes a managed system approach with continuous review to address specific and changing conditions of sites. Policies, accountability mechanisms and assessments are first planned, and then implemented, every day functioning is monitored, corrective actions are developed on the basis of issues and reports are compiled for planning of new improvements. This research program provided OPG with new methods for preventing accidents more efficiently.

Recreation value of a waterway and changes in this value

International Nuclear Information System (INIS)

Aittoniemi, P.

1991-01-01

The uniquely rich hydrological and archipelagic nature of Finland creates versatile opportunities for spending of leisure time. As various uses of waterways compete with each other, it is difficult to compare advantages and disadvantages of operations in view of various interests. This is why efforts have been made to develop methods to make the effect commensurable. Usability of shores is one important factor in the assessment of recreation use of waterways. When influence of water level changes in usability of shores is estimated, shore and bottom slope and quality, and uses and user numbers of the shores must be known. In several assessment methods, usability of shore is depicted by distance of the shifted shoreline (due to the changed water level) from the 'good' status. The studies on changes in the recreation value or usability of shores should be started by making efforts to classify and estimate various effects separately. If the value is wished to be given as one figure, the calculation basis applied, the weights and the used value functions must be stated clearly with the results. It is equally important to make a sensitivity analysis, i.e. to study effects of changes in uncertain input data on the results

CLIMATE CHANGE AND THE RISK MANAGEMENT IN SERBIAN INLAND WATERWAY TRANSPORT

Directory of Open Access Journals (Sweden)

Todor Backalic

2012-12-01

Full Text Available Climate changes require special attention and global monitoring. Impacts on nature and industry are increasingly evident. Water transport could be the backbone of the future European combined transport system. Unfortunately, risks in water transport are perhaps an under researched area and consequently, this article outlines a rationale, why it is necessary to develop competence about risk in water transport. The development of the cargo transport in river traffic depends directly on technical-exploitative characteristics of the network of inland waterways. Research of navigational abilities of inland waterways always comes before building ships or making a transport schedule. Navigation characteristics of rivers have to be determined as precise as possible, especially from the aspect of determination the possible draught of vessels. River transport due to their operational business and environmental conditions faced with several risks having different degrees of consequences. Current risk assessment methods for water transport just consider some dramatic events. We present a new method for the assessment of risk and vulnerability of water transport where river depth represents a crucial part. The analysis of water level changes on Serbian rivers during the last sixty years was done.

Management of Environmental Resources of Cutoff Bends Along the Tennessee-Tombigbee Waterway.

Science.gov (United States)

1987-11-01

WW2 , pp 51-67. Carey, W. C. 1964. "Discussion of ’Hydraulic Aspects of Arkansas River Sta- bilization,’" Journal of the Waterways and Harbors Division...photographs listed in Table A6, color infrared (IR) photographs of several of the Tombigbee River sites were obtained and used in a qualitative fashion. For

The target programme for water pollution control up to year 2005. The impact to alternative pollution load levels on inland waterways; Vesiensuojelun tavoitteet vuoteen 2005. Vaihtoehtoisten kuormitustasojen vaikutukset sisaevesissae

Energy Technology Data Exchange (ETDEWEB)

Marttunen, M. [eds.

1998-11-01

The publication presents waterway-specific pollution loading surveys connected with the target programme for water pollution control up to 2005 and the results of a survey concerning inland waters. The work evaluates and compares the magnitude and significance of future pollution loads from various sources on the state of the waterway and assesses the impact on the condition of the waterway of two alternative pollution loading levels. The survey was conducted on 24 lakes or parts thereof and 10 rivers. Sixteen of these are subject to loading from the pulls and paper industry. The waterways selected for examination were especially ones for which relatively recent loading analyses were available and to which water quality models have been applied. The general classification of fitness for use was used as a benchmark for changes occurring in the water quality of the waterways. The findings show that particularly the large waterway systems can be moved into a higher fitness for use class by reducing substantially the nutrient loading. Significant improvement in the condition of eutrophic lakes and coastal rivers with their internal loads is difficult. (orig.) 26 refs.

76 FR 8653 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

Science.gov (United States)

2011-02-15

... Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor Navigation Canal, New Orleans, Orleans Parish, LA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from... Lock), at New Orleans, Orleans Parish, Louisiana. This deviation is necessary to replace all of the...

75 FR 78601 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

Science.gov (United States)

2010-12-16

... Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor Navigation Canal, New Orleans, Orleans Parish, LA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from... Harvey Lock), at New Orleans, Orleans Parish, Louisiana. This deviation is necessary to adjust the...

Position paper: Inland waterways classification for South America : Core concepts and initial proposals

NARCIS (Netherlands)

Jaimurzina, A.; Koedijk, O.C.; Wilmsmeier, G.; Dohms, A.; Montiel, D.; Pauli, G.; Rigo, P; Spengler, T.; Wens, F.

2016-01-01

South America, as of yet, has not been able to take full advantage of its extensive system of naturally navigable waterways and in making them an integrated part of the region’s transport network to cater for the ever increasing demand for cargo and human mobility. Infrastructure limitations are one

A Multi-Agent System for Tracking the Intent of Surface Contacts in Ports and Waterways

National Research Council Canada - National Science Library

Tan, Kok S

2005-01-01

...) and employ them to identify asymmetric maritime threats in port and waterways. Each surface track is monitored by a compound multi-agent system that comprise of the several intent models, each containing a nested multi-agent system...

76 FR 77119 - Special Local Regulations; Pompano Beach Holiday Boat Parade, Intracoastal Waterway, Pompano...

Science.gov (United States)

2011-12-12

...-AA08 Special Local Regulations; Pompano Beach Holiday Boat Parade, Intracoastal Waterway, Pompano Beach... Pompano Beach Holiday Boat Parade on Sunday, December 11, 2011. The marine parade will consist of... Friday, except Federal holidays. FOR FURTHER INFORMATION CONTACT: If you have questions on this temporary...

ORNL Trusted Corridors Project: Watts Bar Dam Inland Waterway Project

Energy Technology Data Exchange (ETDEWEB)

Walker, Randy M [ORNL; Gross, Ian G [ORNL; Smith, Cyrus M [ORNL; Hill, David E [ORNL

2011-11-01

Radiation has existed everywhere in the environment since the Earth's formation - in rocks, soil, water, and plants. The mining and processing of naturally occurring radioactive materials for use in medicine, power generation, consumer products, and industry inevitably generate emissions and waste. Radiological measuring devices have been used by industry for years to measure for radiation in undesired locations or simply identify radioactive materials. Since the terrorist attacks on the United States on 9-11-01 these radiation measuring devices have proliferated in many places in our nation's commerce system. DOE, TVA, the Army Corps and ORNL collaborated to test the usefulness of these devices in our nation's waterway system on this project. The purpose of the Watts Bar Dam ORNL Trusted Corridors project was to investigate the security, safety and enforcement needs of local, state and federal government entities for state-of-the-art sensor monitoring in regards to illegal cargo including utilization of the existing infrastructure. TVA's inland waterways lock system is a recognized and accepted infrastructure by the commercial carrier industry. Safety Monitoring activities included tow boat operators, commercial barges and vessels, recreational watercraft and their cargo, identification of unsafe vessels and carriers, and, monitoring of domestic and foreign commercial vessels and cargo identification. Safety Enforcement activities included cargo safety, tracking, identification of hazardous materials, waterway safety regulations, and hazardous materials regulations. Homeland Security and Law Enforcement Applications included Radiological Dispersive Devices (RDD) identification, identification of unsafe or illicit transport of hazardous materials including chemicals and radiological materials, and screening for shipments of illicit drugs. In the Fall of 2005 the SensorNet funding for the project expired. After several unsuccessful attempts to

ORNL Trusted Corridors Project: Watts Bar Dam Inland Waterway Project

International Nuclear Information System (INIS)

Walker, Randy M.; Gross, Ian G.; Smith, Cyrus M.; Hill, David E.

2011-01-01

Radiation has existed everywhere in the environment since the Earth's formation - in rocks, soil, water, and plants. The mining and processing of naturally occurring radioactive materials for use in medicine, power generation, consumer products, and industry inevitably generate emissions and waste. Radiological measuring devices have been used by industry for years to measure for radiation in undesired locations or simply identify radioactive materials. Since the terrorist attacks on the United States on 9-11-01 these radiation measuring devices have proliferated in many places in our nation's commerce system. DOE, TVA, the Army Corps and ORNL collaborated to test the usefulness of these devices in our nation's waterway system on this project. The purpose of the Watts Bar Dam ORNL Trusted Corridors project was to investigate the security, safety and enforcement needs of local, state and federal government entities for state-of-the-art sensor monitoring in regards to illegal cargo including utilization of the existing infrastructure. TVA's inland waterways lock system is a recognized and accepted infrastructure by the commercial carrier industry. Safety Monitoring activities included tow boat operators, commercial barges and vessels, recreational watercraft and their cargo, identification of unsafe vessels and carriers, and, monitoring of domestic and foreign commercial vessels and cargo identification. Safety Enforcement activities included cargo safety, tracking, identification of hazardous materials, waterway safety regulations, and hazardous materials regulations. Homeland Security and Law Enforcement Applications included Radiological Dispersive Devices (RDD) identification, identification of unsafe or illicit transport of hazardous materials including chemicals and radiological materials, and screening for shipments of illicit drugs. In the Fall of 2005 the SensorNet funding for the project expired. After several unsuccessful attempts to find a Federal sponsor

Using chloride and other ions to trace sewage and road salt in the Illinois Waterway

Science.gov (United States)

Kelly, W.R.; Panno, S.V.; Hackley, Keith C.; Hwang, H.-H.; Martinsek, A.T.; Markus, M.

2010-01-01

Chloride concentrations in waterways of northern USA are increasing at alarming rates and road salt is commonly assumed to be the cause. However, there are additional sources of Cl- in metropolitan areas, such as treated wastewater (TWW) and water conditioning salts, which may be contributing to Cl- loads entering surface waters. In this study, the potential sources of Cl- and Cl- loads in the Illinois River Basin from the Chicago area to the Illinois River's confluence with the Mississippi River were investigated using halide data in stream samples and published Cl- and river discharge data. The investigation showed that road salt runoff and TWW from the Chicago region dominate Cl- loads in the Illinois Waterway, defined as the navigable sections of the Illinois River and two major tributaries in the Chicago region. Treated wastewater discharges at a relatively constant rate throughout the year and is the primary source of Cl- and other elements such as F- and B. Chloride loads are highest in the winter and early spring as a result of road salt runoff which can increase Cl- concentrations by up to several hundred mg/L. Chloride concentrations decrease downstream in the Illinois Waterway due to dilution, but are always elevated relative to tributaries downriver from Chicago. The TWW component is especially noticeable downstream under low discharge conditions during summer and early autumn when surface drainage is at a minimum and agricultural drain tiles are not flowing. Increases in population, urban and residential areas, and roadways in the Chicago area have caused an increase in the flux of Cl- from both road salt and TWW. Chloride concentrations have been increasing in the Illinois Waterway since around 1960 at a rate of about 1 mg/L/a. The increase is largest in the winter months due to road salt runoff. Shallow groundwater Cl- concentrations are also increasing, potentially producing higher base flow concentrations. Projected increases in population and

The impact of ornithogenic inputs on phosphorous transport from altered wetland soils to waterways in East Mediterranean ecosystem.

Science.gov (United States)

Litaor, M Iggy; Reichmann, O; Dente, E; Naftaly, A; Shenker, M

2014-03-01

Large flocks of Eurasian crane (Grus grus, >35,000) have begun wintering in an altered wetland agro-ecosystem located in Northern Israel, a phenomenon that attracts more than 400,000 eco-tourists a year. A 100-ha plot has been used to feed the cranes in order to protect nearby fields. The objective of this study was to evaluate the influence of this bird's feeding practice on the P status of the altered wetland soils and waterways. We installed a series of wells at two depths (40 and 90 cm) between two major waterways in the feeding area and monitored the hydraulic heads and collected groundwater samples for elemental analyses. We collected six soil cores and four sediment samples from the waterways and conducted sequential P extraction. We found significant increase in groundwater soluble reactive P (SRP) (>0.5 mg l(-1)) compared with much lower concentrations (~0.06 mg l(-1)) collected in the period prior to the feeding. We found significant decrease in Fe((II)), Ca, and SO4 concentrations in the shallow groundwater (33, 208, and 213 mg l(-1), respectively) compared with the period prior to the feeding (47, 460, and 370 mg l(-1) respectively). An increase in the more labile P fraction was observed in soils and sediments compared with the period before the feeding. The P input by bird excrement to the feeding area was estimated around 700 kg P per season, while P removal by plant harvesting was estimated around 640 kg Pyr(-1). This finding supports the current eco-tourism practices in the middle of intensive farming area, suggesting little impact on waterways. Copyright © 2013 Elsevier B.V. All rights reserved.

Exploring the links between natural resource use and biophysical status in the waterways of the North Rupununi, Guyana.

Science.gov (United States)

Mistry, Jayalaxshmi; Simpson, Matthews; Berardi, Andrea; Sandy, Yung

2004-09-01

The North Rupununi District in south-west Guyana is comprised of a mosaic of ecosystems, including savannas, wetlands and forests, and is home to the Makushi Amerindians, who depend on the waterways for their subsistence needs. With logging and mining seen as increasing threats to the region, it is necessary to look at methods for engaging stakeholders in monitoring the status of their natural resources. This paper presents the results of a pilot study carried out to investigate water use by the Makushi Amerindians, and collect baseline data on the hydro-morphological aspects of the waterways. Methods included informal interviews, the use of the River Habitat Survey (RHS), and water quality measurements. The results indicate the heavy reliance of the Makushi on the waterways for their daily lives, particularly on fishing. Although ponds and creeks are important sources of fish, the rivers provide much larger catches of a greater diversity of fish species, both in the wet and dry seasons. The physical characteristics of the water sources used by the Makushi are mainly associated with the surrounding habitat types: the savanna areas containing the more nutrient rich white-water rivers, and the tropical forest areas containing the less nutrient rich black-water rivers. This study indicates that at present there is no direct evidence of adverse impacts on the waterways used by the Makushi in terms of fish catches, habitat conditions and water quality. A monitoring scheme was set up using this study's outputs as a baseline from which any future changes can be compared. Further work is to be carried out over the next three years to produce monitoring and sustainable management procedures for the North Rupununi ecosystems, by linking the physical attributes of the environment to biodiversity and subsequently local livelihoods, and by building capacity of local stakeholders through training.

Effect of climate change on crop production patterns with implications to transport flows and inland waterways.

Science.gov (United States)

2011-12-01

This project analyzed the demand for transportation capacity and changes in transportation flows on : inland waterways due to shifts in crop production patterns induced by climate change. Shifts in the crop : production mix have been observed in rece...

Evaluation of Hydraulic Fracturing (Fracking) Plays for Potential Impact on USACE-Managed Waterways

Science.gov (United States)

2015-01-01

Approved for public release; distribution is unlimited. ERDC/TN DOTS-15-1 January 2015 Evaluation of Hydraulic Fracturing ( Fracking ) Plays...fracturing operations (hydrofracturing or “ fracking ”) to increase petrochemical (natural gas and petroleum) production resulted in elevated environmental...Shale, has raised concerns that fracking operations could impact waterways managed by the U.S. Army Corps of Engineers (USACE). The purpose of this

Coefficients of Propeller-hull Interaction in Propulsion System of Inland Waterway Vessels with Stern Tunnels

Directory of Open Access Journals (Sweden)

Jan Kulczyk

2014-09-01

Full Text Available Propeller-hull interaction coefficients - the wake fraction and the thrust deduction factor - play significant role in design of propulsion system of a ship. In the case of inland waterway vessels the reliable method of predicting these coefficients in early design stage is missing. Based on the outcomes from model tests and from numerical computations the present authors show that it is difficult to determine uniquely the trends in change of wake fraction and thrust deduction factor resulting from the changes of hull form or operating conditions. Nowadays the resistance and propulsion model tests of inland waterway vessels are carried out rarely because of relatively high costs. On the other hand, the degree of development of computational methods enables’ to estimate the reliable values o interaction coefficients. The computations referred to in the present paper were carried out using the authors’ own software HPSDKS and the commercial software Ansys Fluent.

75 FR 12688 - Safety Zone; Gallants Channel, Beaufort, NC

Science.gov (United States)

2010-03-17

... and the use of heavy equipment and machinery in the waterway. Under 5 U.S.C. 553(d)(3), the Coast... debris and the use of heavy equipment and machinery in the waterway. Background and Purpose The State of... repairs present potential hazards to mariners and property from falling debris and the use of heavy...

78 FR 75359 - Waterway Suitability Assessment for Construction and Operation of Liquefied Gas Terminals; Orange...

Science.gov (United States)

2013-12-11

... Assessment for Construction and Operation of Liquefied Gas Terminals; Orange, TX AGENCY: Coast Guard, DHS... waterfront facility handling and storing Liquefied Hazardous Gas (LHG) at its Orange, Texas facility. The... LHG marine traffic in the associated waterway. INVISTA, S.a.r.l. located in Orange, Texas submitted an...

76 FR 78151 - Special Local Regulations; Boca Raton Holiday Boat Parade, Intracoastal Waterway, Boca Raton, FL

Science.gov (United States)

2011-12-16

...-AA08 Special Local Regulations; Boca Raton Holiday Boat Parade, Intracoastal Waterway, Boca Raton, FL... Raton Holiday Boat Parade on Saturday, December 17, 2011. The marine parade will consist of... through Friday, except Federal holidays. FOR FURTHER INFORMATION CONTACT: If you have questions on this...

Soot concentrations along busy inland waterways in the Netherlands; Roetconcentraties langs drukke binnenvaarwegen in Nederland

Energy Technology Data Exchange (ETDEWEB)

Keuken, M.; Jonkers, S.; Moerman, M. [TNO Built Environment and Geosciences, Delft (Netherlands); Hoek, G. [Institute for Risk Assessment Sciences IRAS, Utrecht University, Utrecht (Netherlands)

2013-08-15

Exploratory research by TNO and IRAS shows that residents in the Netherlands are exposed to soot concentrations along busy inland waterways similar to living along a busy highway [Dutch] Verkennend onderzoek van TNO en IRAS laat zien dat bewoners langs drukke binnenvaarwegen worden blootgesteld aan roetconcentraties vergelijkbaar met wonen langs een drukke snelweg.

33 CFR 207.100 - Inland waterway from Delaware River to Chesapeake Bay, Del. and Md. (Chesapeake and Delaware...

Science.gov (United States)

2010-07-01

... enter or pass through any part of the waterway will be contingent on the vessel's having adequate... facilities are of limited capacity, and permission to occupy them for periods exceeding 24 hours must be...

Cyanobacteria of the 2016 Lake Okeechobee and Okeechobee Waterway harmful algal bloom

Science.gov (United States)

Rosen, Barry H.; Davis, Timothy W.; Gobler, Christopher J.; Kramer, Benjamin J.; Loftin, Keith A.

2017-05-31

The Lake Okeechobee and the Okeechobee Waterway (Lake Okeechobee, the St. Lucie Canal and River, and the Caloosahatchee River) experienced an extensive harmful algal bloom within Lake Okeechobee, the St. Lucie Canal and River and the Caloosahatchee River in 2016. In addition to the very visible bloom of the cyanobacterium Microcystis aeruginosa, several other cyanobacteria were present. These other species were less conspicuous; however, they have the potential to produce a variety of cyanotoxins, including anatoxins, cylindrospermopsins, and saxitoxins, in addition to the microcystins commonly associated with Microcystis. Some of these species were found before, during, and 2 weeks after the large Microcystis bloom and could provide a better understanding of bloom dynamics and succession. This report provides photographic documentation and taxonomic assessment of the cyanobacteria present from Lake Okeechobee and the Caloosahatchee River and St. Lucie Canal, with samples collected June 1st from the Caloosahatchee River and Lake Okeechobee and in July from the St. Lucie Canal. The majority of the images were of live organisms, allowing their natural complement of pigmentation to be captured. The report provides a digital image-based taxonomic record of the Lake Okeechobee and the Okeechobee Waterway microscopic flora. It is anticipated that these images will facilitate current and future studies on this system, such as understanding the timing of cyanobacteria blooms and their potential toxin production.

Evaluation of streambed scour at bridges over tidal waterways in Alaska

Science.gov (United States)

Conaway, Jeffrey S.; Schauer, Paul V.

2012-01-01

The potential for streambed scour was evaluated at 41 bridges that cross tidal waterways in Alaska. These bridges are subject to several coastal and riverine processes that have the potential, individually or in combination, to induce streambed scour or to damage the structure or adjacent channel. The proximity of a bridge to the ocean and water-surface elevation and velocity data collected over a tidal cycle were criteria used to identify the flow regime at each bridge, whether tidal, riverine, or mixed, that had the greatest potential to induce streambed scour. Water-surface elevations measured through at least one tide cycle at 32 bridges were correlated to water levels at the nearest tide station. Asymmetry of the tidal portion of the hydrograph during the outgoing tide at 12 bridges indicated that riverine flows were stored upstream of the bridge during the tidal exchange. This scenario results in greater discharges and velocities during the outgoing tide compared to those on the incoming tide. Velocity data were collected during outgoing tides at 10 bridges that experienced complete flow reversals, and measured velocities during the outgoing tide exceeded the critical velocity required to initiate sediment transport at three sites. The primary risk for streambed scour at most of the sites considered in this study is from riverine flows rather than tidal fluctuations. A scour evaluation for riverine flow was completed at 35 bridges. Scour from riverine flow was not the primary risk for six tidally-controlled bridges and therefore not evaluated at those sites. Field data including channel cross sections, a discharge measurement, and a water-surface slope were collected at the 35 bridges. Channel instability was identified at 14 bridges where measurable scour and or fill were noted in repeated surveys of channel cross sections at the bridge. Water-surface profiles for the 1-percent annual exceedance probability discharge were calculated by using the Hydrologic

76 FR 35104 - Safety Zone; Waterway Closure, Atchafalaya River From Mile Marker 117 (Morgan City Railroad...

Science.gov (United States)

2011-06-16

...-AA00 Safety Zone; Waterway Closure, Atchafalaya River From Mile Marker 117 (Morgan City Railroad Bridge... with rising flood water in the Atchafalaya River. Basis and Purpose Captain of the Port Morgan City... safety zone is located on the specified waters of the Atchafalaya River between MM 117 (Morgan City...

Transport and handling of dangerous goods. Training of persons in charge of vehicles or vessels carrying dangerous goods by road or by inland waterways (Dangerous Goods 1979 No.1)

International Nuclear Information System (INIS)

1979-01-01

This Order supplements the Regulations of 15 April 1945 on the transport of dangerous goods by rail, land and inland waterways. It deals with the training of persons in charge of vehicles or boats carrying dangerous goods by road or by inland waterways. It refers in particular to transport of radioactive materials. (NEA) [fr

Assessment of Hydraulic Conditions Supporting the Recruitment of Asian Carp in the Illinois Waterway - A Case Study Using Known Spawning Events of 2015

Science.gov (United States)

Soong, D. T.; Garcia, T.; Duncker, J.; Zhu, Z.; Butler, S.; Diana, M.; Wahl, D.

2016-12-01

The upstream movement of Asian carp in the Illinois Waterway poses a potential threat to the Great Lakes. If established within the Great Lakes, Asian carp may disrupt the food web and harm the ecosystems of the Great Lakes. Understanding the Asian carp reproduction, including the timing and locations of adult spawning and the transport and dispersal of eggs and larvae, is essential information for managing the Asian carp population in the Illinois Waterway. The Fluvial Egg Drift Simulator (FluEgg) model, a Lagrangian particle tracking model, has been used to study the transport and dispersal of eggs and larvae. The FluEgg model inputs are water temperature and hydraulic properties. At present, field measured or modeled hydraulics from steady-state simulations have been used in FluEgg modeling and the applications have shown useful results for evaluating Asian carp reproduction in the Illinois Waterway. However, there is a need to use data based on more representative time-variable hydraulic conditions from spawning to the time larvae reach the Gas Bladder Inflation Stage (GBI). The GBI stage is critical because that is the stage when the young fish seek nursery habitat. In June 2015, Asian carp spawning was observed at two locations along the Illinois Waterway, one below Starved Rock Lock and Dam near Utica, and the one in the La Grange Pool near Havana, Illinois. This study analyzes how hydraulic modeling can improve the predictability of the FluEgg model. An unsteady HEC-RAS hydraulic model of the Illinois Waterway from Brandon Road Lock and Dam to Grafton, Illinois was used to reproduce the June 2015 flood event. Hydraulic data from HEC-RAS modeling, including predicted spatial and temporal discharge, water depth, and shear velocity; and measured water temperature data were used as input to the FluEgg model. FluEgg simulation results illustrate the downstream drifting of eggs and larvae until reaching the GBI stage. These simulation results can be analyzed

The analysis of inland water transport on technically developed Polish section of the E70 waterway using GIS tools in the years 2005-2014

Science.gov (United States)

Rabant, Hubert; Szatten, Dawid; Nadolny, Grzegorz

2017-11-01

The article presents the characteristics of changes in the spatial extent of transport on the hydrotechnically developed section of the E70 waterway in Poland using methods and tools of geographic information systems (GIS). The results of the analyzes show the conditions for vessel traffic, their type and volatility in the years 2005-2014. The methods made it possible to analyze the spatial determinants of navigation. The obtained results were referred to the current state and prospects for development of Polish waterways and indicated that the applied tools have a great application role in the research on their logistics and development.

Longitudinal dispersion of radioactive substances in Federal waterways

Energy Technology Data Exchange (ETDEWEB)

Krause, W.J. [Bundesanstalt fuer Gewaesserkunde (BfG), Koblenz (Germany); Speer, W.; Luellwitz, T.; Cremer, M.; Tolksdorf, W.

2007-08-15

In the context of radioactivity monitoring in German Federal Waterways (BWStr) by the Federal Institute of Hydrology (BfG) according to the Precautionary Radiation Protection Act (StrVG), the prediction of the dispersion of radioactive substances in water is one of the key tasks. The aim is the forecasting of the longitudinal dispersion of concentrations of soluble hazardous substances in flowing water. These predictions are based on the so-called dispersion tests with tritium as a tracer that the BfG has performed since 1980. Characteristic parameters like discharge-dependent flow velocities, dispersion and elimination constants related to emission sources or selected river sections are determined. They will serve as basis for a mathematical model to forecast discharge-dependent flow velocities, expected impact times, concentration maxima, and the duration of critical increases in concentrations. In the following, the results obtained till now from three investigation campaigns on the River Weser and its source rivers Werra and Fulda are described. (orig.)

Ohio River navigation investment model: Requirements and model design

Energy Technology Data Exchange (ETDEWEB)

Bronzini, M.S.; Curlee, T.R.; Leiby, P.N.; Southworth, F.; Summers, M.S.

1998-01-01

Oak Ridge National Laboratory is assisting the US Army Corps of Engineers in improving its economic analysis procedures for evaluation of inland waterway investment projects along the Ohio River System. This paper describes the context and design of an integrated approach to calculating the system-wide benefits from alternative combinations of lock and channel improvements, providing an ability to project the cost savings from proposed waterway improvements in capacity and reliability for up to fifty years into the future. The design contains an in-depth treatment of the levels of risk and uncertainty associated with different multi-year lock and channel improvement plans, including the uncertainty that results from a high degree of interaction between the many different waterway system components.

Geographic Information System (GIS) characterization of benthic and emergent areas in the Intracoastal Waterway, Sarasota County, Florida in 1987 (NODC Accession 0000607)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This GIS layer graphically represents algae, seagrass, tidal marshes, mangroves, and oyster bed coverages found throughout the Intracoastal Waterway in Sarasota...

Patterns in benthic populations in the Milford Haven waterway following the 'Sea Empress' oil spill with special reference to amphipods.

Science.gov (United States)

Nikitik, Christopher C S; Robinson, Andrew W

2003-09-01

The macrobenthic fauna of the Milford Haven Waterway was studied in detail following the 'Sea Empress' oil spill in 1996. Contamination patterns indicated heaviest contamination of sediments by oil to have occurred in the lower reaches of the waterway, although water borne hydrocarbons are likely to have penetrated throughout the Haven. Generally, the communities showed little impact of contamination by oil, although some changes were evident at the population level. A decline in the amphipod fauna was observed throughout the Haven, with the genera Ampelisca and Harpinia and the family Isaeidae particularly affected. This was accompanied by increases in both the diversity and abundance of polychaete populations as opportunist species took advantage of the decline of the amphipod fauna. However, within five years of the spill the amphipod fauna has shown clear signs of recovery. The use of the polychaete/amphipod ratio as an indicator of oil pollution is discussed.

LNG as a marine and inland waterway fuel. Contribution of AFG (French gas association) to the national policy framework for the deployment of alternative fuel infrastructures (AFNPF)

International Nuclear Information System (INIS)

2016-06-01

Here in the early 21. Century, the environmental footprint of marine and inland waterway transport is a major concern on a global scale. Under the authority of the International Maritime Organisation (IMO), regulations on atmospheric emissions are becoming increasingly tighter. The European Union (EU) is deeply committed to this endeavour and in particular has adopted Directive 2014/94/EU which aims to facilitate the deployment of an alternative fuels infrastructure. The Directive calls upon Member States to develop by 18 November 2016, national policy frameworks for the deployment of alternative fuel infrastructures (AFNPF) that must designate an appropriate number of LNG refuelling points in maritime and inland ports for maritime and inland waterway transport purposes. In light of this, the French Gas Association (AFG), in cooperation with all affected stakeholders and interested parties, has discussed the role of LNG as a marine and inland waterway fuel in the energy transition toward green growth, in order to contribute to the development of France's 'national policy framework' (AFNPF) under the Directive mentioned above. To assess the prospects of the LNG bunkering market in France, as well as the implementation of the corresponding infrastructures, the AFG adopted a scenario-based approach from the user's perspective. Considering that we are in an early stage, the study focuses on the types of ships that are most likely to use LNG, and it examines their traffic in France's major metropolitan ports, along with forecasted activity based on the strategic plans for those ports. Two scenarios - one being rather conservative (baseline) and the other being more optimistic - were examined over three timelines: 2020, 2025 and 2030. The scenarios lead to a gradual implementation of LNG fuel in French ports, on the three coastlines and along the five inland waterway corridors. They show LNG fuel needs in all the ports of the central TEN

Application of Kalman filter to short-term tide level prediction by Yen, P.-H., Jan, C.-D., Lee, Y.-P. and Lee, H.-F. (J. Waterway Port Coast. Ocean Eng. 122(5); 1996; pp 226-231: Discussion

Digital Repository Service at National Institute of Oceanography (India)

Mandal, S.; Chandramohan, P.

stream_size 2 stream_content_type text/plain stream_name J_Waterway_Port_Coast_Eng_124_213.pdf.txt stream_source_info J_Waterway_Port_Coast_Eng_124_213.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

The investigation of ship maneuvering with hydrodynamic effects between ships in curved narrow channel

Directory of Open Access Journals (Sweden)

Chun-Ki Lee

2016-01-01

Full Text Available The hydrodynamic interaction between two large vessels can't be neglected when two large vessels are closed to each other in restricted waterways such as in a harbor or narrow channel. This paper is mainly concerned with the ship maneuvering motion based on the hydrodynamic interaction effects between two large vessels moving each other in curved narrow channel. In this research, the characteristic features of the hydrodynamic interaction forces between two large vessels are described and illustrated, and the effects of velocity ratio and the spacing between two vessels are summarized and discussed. Also, the Inchon outer harbor area through the PALMI island channel in Korea was selected, and the ship maneuvering simulation was carried out to propose an appropriate safe speed and distance between two ships, which is required to avoid sea accident in confined waters. From the inspection of this investigation, it indicates the following result. Under the condition of SP12≤0.5L, it may encounter a dangerous tendency of grounding or collision due to the combined effect of the interaction between ships and external forces. Also considering the interaction and wind effect as a parameter, an overtaken and overtaking vessel in narrow channel can navigate while keeping its own original course under the following conditions; the lateral separation between two ships is about kept at 0.6 times of ship length and 15 degrees of range in maximum rudder angle. On the other hand, two ships while overtaking in curved narrow channel such as Inchon outer harbor in Korea should be navigated under the following conditions; SP12 is about kept at 1.0 times of ship length and the wind velocity should not be stronger than 10 m/s.

Innovative 'Artificial Mussels' technology for assessing spatial and temporal distribution of metals in Goulburn-Murray catchments waterways, Victoria, Australia: effects of climate variability (dry vs. wet years).

Science.gov (United States)

Kibria, Golam; Lau, T C; Wu, Rudolf

2012-12-01

The "Artificial mussel" (AM), a novel passive sampling technology, was used for the first time in Australia in freshwater to monitor and assess the risk of trace metals (Cd, Cu, Hg, Pb, and Zn). AMs were deployed at 10 sites within the Goulburn-Murray Water catchments, Victoria, Australia during a dry year (2009-2010) and a wet year (2010-2011). Our results showed that the AMs accumulated all the five metals. Cd, Pb, Hg were detected during the wet year but below detection limits during the dry year. At some sites close to orchards, vine yards and farming areas, elevated levels of Cu were clearly evident during the dry year, while elevated levels of Zn were found during the wet year; the Cu indicates localized inputs from the agricultural application of copper fungicide. The impacts from old mines were significantly less compared 'hot spots'. Our study demonstrated that climate variability (dry, wet years) can influence the metal inputs to waterways via different transport pathways. Using the AMs, we were able to identify various 'hot spots' of heavy metals, which may pose a potential risk to aquatic ecosystems (sub-lethal effects to fish) and public (via food chain metal bioaccumulation and biomagnification) in the Goulburn-Murray Water catchments. The State Protection Policy exempted artificial channels and drains from protection of beneficial use (including protection of aquatic ecosystems) and majority of sites ('hot spots') were located within artificial irrigation channels. Copyright © 2012 Elsevier Ltd. All rights reserved.

76 FR 36318 - Safety Zone; Waterway Closure, Morgan City-Port Allen Route From Mile Marker 0 to Port Allen Lock

Science.gov (United States)

2011-06-22

... Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not create an environmental risk to health or risk to...-AA00 Safety Zone; Waterway Closure, Morgan City-Port Allen Route From Mile Marker 0 to Port Allen Lock...

Macrobenthic monitoring in the Milford Haven waterway following the Sea Empress oil spill of February 1996

International Nuclear Information System (INIS)

Hobbs, G.; Smith, J.

1998-03-01

Surveys were carried out in the Milford Haven waterway between Lawrenny and West Angle Bay in March 1996 and April 1997 as part of a programme to monitor the impact of the Sea Empress spill on the sea bed macrofauna within the Haven. Samples were taken at eleven locations for macrobenthos, sediment particle size analysis and determination of hydrocarbon content. Additional data was obtained from a larger scale survey of the waterway in October 1996 which included nine of the eleven stations designated for this sampling programme and 'baseline' data was taken from a similar survey carried out in October 1993. The most noticeable feature of the post-spill data is the low abundance and diversity of the amphipod fauna of the water compared with the October 1993 'baseline'. Although this cannot be ascribed with certainty to the Sea Empress oil spill due to the 21/2 year interval during which no monitoring occurred, depletion of the amphipod fauna is a consistent feature of many previous post-spill studies where there was definitive analytical evidence of oil contamination of the sediments. This project has provided a sound basis for monitoring the progress of the macrobenthic fauna of the Haven in the years after the incident. The greatest benefit in such programmes will only be realised in the long term and it is recommended that monitoring should continue. (author)

Study on the ecosystem construction of using ecopath model in inland waterway

Science.gov (United States)

Zhao, Junjie; Bai, Jing; Zhang, Lu; Wang, Ning; Shou, Youping

2018-04-01

In this paper, Ecopath with Ecosim 5.1 software is used to simulate the constructed water ecosystem of inland waterway. According to the characteristics of feeding relationship, the ecopath model of water ecosystem is divided into seven functional groups: phytoplankton, hydrophyte, zooplankton, herbivorous, omnivorous, polychaetes and detritus. By analyzing the important ecological parameters of the ecosystem, such as biomass, biomass / biomass, consumption / biomass, trophic level and ecological nutrient conversion efficiency, the software integrates the energy flow process of the ecosystem, the ratio of the total net primary production and the sum of all respiratory flows is 1.314, it’s indicating that the ecosystem is equilibrium. The research method of this paper can be widely used to evaluate the stability of the ecosystem of the domestic river.

Feasability study for waterway infrastructure: International overview and methodological recommendations

Energy Technology Data Exchange (ETDEWEB)

Santos Fontes Pereira, L. dos; Brandão, R.; Yamashita, Y.; Guilherme de Aragão, J.J.

2016-07-01

The context in which the waterway transportation is in Brazil makes clear the development need of specific methodologies for the sector planning. This paper aims to compare the methods of analysis of technical, economic and environmental viability, adopted in Europe, United States and Brazil, listing the best practices and possible improvements of the method adopted in Brazil. The analysis of the documents was based on comparative method, seeking the common elements from its attributes. Each document was analysed in terms of: its structure; type of impacts; required indicators on each impact analysis; reference values for classification of indicators; and the form of integrated analysis of different impacts. The study suggests the inclusion of certain changes in the methodology of calculation and in its combination of tools and parameters used in the measurement of fiscal impacts on the comparative analysis of standard models usually adopted in the United States, Europe and the World Bank. (Author)

The Coast Guard Proceedings of the Marine Safety and Security Council. Volume 72, Number 2, Summer 2015

Science.gov (United States)

2015-01-01

we will increase maritime situational aware- ness through improved risk-based collection, analysis , and mitigation through improved waterway design...entrance buoys mark the seaward access to a waterway. Buoys can be either unlighted or lighted and display a rhythmic ashing light signal. They can...structures that provide a platform for a rhythmic , ashing light signal. This includes range lights that mark the centerline of a channel, sector

24 CFR 1710.115 - Subdivision characteristics and climate.

Science.gov (United States)

2010-04-01

... erosion, sedimentation or periodic flooding throughout the subdivision? (2) If there is a program... seeding in areas of heavy grading or cut and fill along with the construction of diversion channels, ditches, outlet channels, waterway stabilizers and sediment control basins.) (f) Nuisances. Are there any...

Applicability of market-based instruments for safeguarding water quality in coastal waterways: Case study for Darwin Harbour, Australia

Science.gov (United States)

Greiner, Romy

2014-02-01

Water pollution of coastal waterways is a complex problem due to the cocktail of pollutants and multiplicity of polluters involved and pollution characteristics. Pollution control therefore requires a combination of policy instruments. This paper examines the applicability of market-based instruments to achieve effective and efficient water quality management in Darwin Harbour, Northern Territory, Australia. Potential applicability of instruments is examined in the context of biophysical and economic pollution characteristics, and experience with instruments elsewhere. The paper concludes that there is potential for inclusion of market-based instruments as part of an instrument mix to safeguard water quality in Darwin Harbour. It recommends, in particular, expanding the existing licencing system to include quantitative pollution limits for all significant point polluters; comprehensive and independent pollution monitoring across Darwin Harbour; public disclosure of water quality and emissions data; positive incentives for landholders in the Darwin Harbour catchment to improve land management practices; a stormwater offset program for greenfield urban developments; adoption of performance bonds for developments and operations which pose a substantial risk to water quality, including port expansion and dredging; and detailed consideration of a bubble licensing scheme for nutrient pollution. The paper offers an analytical framework for policy makers and resource managers tasked with water quality management in coastal waterways elsewhere in Australia and globally, and helps to scan for MBIs suitable in any given environmental management situation.

Tritium sample analyses in the Savannah River and associated waterways following the K-reactor release of December 1991

International Nuclear Information System (INIS)

Beals, D.M.; Dunn, D.L.; Hall, G.; Kantelo, M.V.

1992-01-01

An unplanned release of tritiated water occurred at K reactor on SRS between 22-December and 25-December 1991. This water moved down through the effluent canal, Pen Branch, Steel Creek and finally to the Savannah River. Samples were collected in the Savannah River and associated waterways over a period of a month. The Environmental Technology Section (ETS) of the Savannah River Laboratory performed liquid scintillation analyses to monitor the passage of the tritiated water from SRS to the Atlantic Ocean

A numerical study on ship-ship interaction in shallow and restricted waterway

Directory of Open Access Journals (Sweden)

Sungwook Lee

2015-09-01

Full Text Available In the present study, a numerical prediction method on the hydrodynamic interaction force and moment between two ships in shallow and restricted waterway is presented. Especially, the present study proposes a methodology to overcome the limitation of the two dimensional perturbation method which is related to the moored-passing ship interaction. The validation study was performed and compared with the experiment, firstly. Afterward, in order to propose a methodology in terms with the moored-passing ship interaction, further studies were performed for the moored-passing ship case with a Reynolds Averaged Navier-Stokes (RANS calculation which is using OpenFOAM with Arbitrary Coupled Mesh Interface (ACMI technique and compared with the experiment result. Finally, the present study proposes a guide to apply the two dimensional perturbation method to the moored-passing ship interaction. In addition, it presents a possibility that the RANS calculation with ACMI can applied to the ship-ship interaction without using a overset moving grid technique.

Source characterization using compound composition and stable carbon isotope ratio of PAHs in sediments from lakes, harbor, and shipping waterway

International Nuclear Information System (INIS)

Kim, Moonkoo; Kennicutt, Mahlon C.; Qian, Yaorong

2008-01-01

Molecular compositions and compound specific stable carbon isotope ratios of polycyclic aromatic hydrocarbons (PAH) isolated from sediments were used to characterize possible sources of contamination at an urban lake, a harbor, a shipping waterway, and a relatively undisturbed remote lake in the northwest United States. Total PAH concentrations in urban lake sediments ranged from 66.0 to 16,500 μg g -1 dry wt. with an average of 2600 μg g -1 , which is ∼ 50, 100, and 400 times higher on average than PAH in harbor (48 μg g -1 on average), shipping waterway (26 μg g -1 ), and remote lake (7 μg g -1 ) sediments, respectively. The PAH distribution patterns, methyl phenanthrene/phenanthrene ratios, and a pyrogenic index at the sites suggest a pyrogenic origin for PAHs. Source characterization using principal component analysis and various molecular indices including C2-dibenzothiophenes/C2-phenanthrenes, C3-dibenzothiophenes/C3-phenanthrenes, and C2-chrysenes/C2-phenanthrenes ratios, was able to differentiate PAH deposited in sediments from the four sites. The uniqueness of the source of the sediment PAHs from urban lake was also illustrated by compound specific stable carbon isotope analysis. It was concluded that urban lake sediments are accumulating PAH from sources that are unique from contamination detected at nearby sites in the same watershed

Transportation Lines on the Mississippi River System and the Gulf Intracoastal Waterway; Transportation Series 4; 1980.

Science.gov (United States)

1982-05-01

EMERALD SEA0SE C_ 133 -.664 17&0 340 3F0 110 𔃺 22js !3 12 t Lo DO 1971 GULF S6*śSE T 66 1010 1100 250 250 90 50 15uC 7C 1530 , -AS,_ 0 DO 1970INDIAN...130 Do 933 1053 1950 3S0 3-0 90 290 - ISOS 1.S. COvkas 19,7 !91. 115-119 00 175 - 1950 - 3S5 99 L6 - 2Q.3, 33 1993 (29 1v0 IVE LOGIN CC, L.ILT J02...WR, C., 4 SONS 2 CHARTERS To OTHERS 4ISSISSIPPI RIVER BYSTEM 33 EMERALD MARINE SERVICE, INC. 2 TOWING AND DRY CARGT 06 INTRACOASTAL WATERWAY Of

Use of Remote Sensing to Detect and Predict Aquatic Nuisance Vegetation Growth in Coastal Louisiana: Summary of Findings

Science.gov (United States)

2018-02-01

Aquatic plants provide habitat and food to a wide range of wildlife and aquatic organisms. They also increase sedimentation and shoreline stability...intracoastal waterways and navigable channels in the United States (Walls et al. 2009; USACE 2009). Though these resources have historically been...navigation in navigation channels , and 2) had potential to become an impediment to navigation in these channels due to growth in and drift from side

Investigating the Lateral Mixing Coefficient in a Compound Channel with Emergent Vegetation over the Floodplain

Directory of Open Access Journals (Sweden)

Hossein hamidifar

2017-02-01

Full Text Available Introduction: Water quality control is very important for people, animals and plants. Predicting the spread of contaminants is important for managing and protecting rivers and streams to the balance of the ecosystem. Pollutants are introduced into waterways, though a variety of sources such as point and non-point sources. Under steady state conditions, where longitudinal mixing is not significant, studying the lateral mixing is essential in evaluating the influence of pollutants on water quality. Lateral or transverse mixing is the hydraulic process by which a plume of contaminant spreads laterally and dilutes. In water quality management, the transverse mixing is more significant than either vertical or longitudinal dispersion, especially, when dealing with the release of wastes from point sources. Hence, a wide range of field, laboratory and numerical modelling approaches, including laboratory and field measurements, and analytical and numerical investigations have been developed, to quantify the lateral mixing coefficient. However, most of the researchers have ignored the effects of vegetation on the lateral mixing process in their studies. Many studies have shown that the flow characteristics through vegetation are different from those in non-vegetated waterways. For example, laboratory studies have revealed that flow velocity and large-scale turbulence tend to be greatly decreased within a plant canopy, because the resistance to flow by the vegetation. Also, vegetation affects the transport of dissolved and particulate material, such as sediment, nutrients and pollutants. In this study, the effect of the floodplain vegetation on lateral mixing coefficient in compound channels is investigated experimentally. Also, a comparison is made between the results of the present study with those obtained by previous researchers. Materials and Methods: Experiments were carried out in a laboratory flume 18m long, 0.9m wide and 0.6m high with an

Channel Power in Multi-Channel Environments

NARCIS (Netherlands)

M.G. Dekimpe (Marnik); B. Skiera (Bernd)

2004-01-01

textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key

Marine habitat mapping of the Milford Haven Waterway, Wales, UK: Comparison of facies mapping and EUNIS classification for monitoring sediment habitats in an industrialized estuary

Science.gov (United States)

Carey, Drew A.; Hayn, Melanie; Germano, Joseph D.; Little, David I.; Bullimore, Blaise

2015-06-01

A detailed map and dataset of sedimentary habitats of the Milford Haven Waterway (MHW) was compiled for the Milford Haven Waterway Environmental Surveillance Group (MHWESG) from seafloor images collected in May, 2012 using sediment-profile and plan-view imaging (SPI/PV) survey techniques. This is the most comprehensive synoptic assessment of sediment distribution and benthic habitat composition available for the MHW, with 559 stations covering over 40 km2 of subtidal habitats. In the context of the MHW, an interpretative framework was developed that classified each station within a 'facies' that included information on the location within the waterway and inferred sedimentary and biological processes. The facies approach provides critical information on landscape-scale habitats including relative location and inferred sediment transport processes and can be used to direct future monitoring activities within the MHW and to predict areas of greatest potential risk from contaminant transport. Intertidal sediment 'facies' maps have been compiled in the past for MHW; this approach was expanded to map the subtidal portions of the waterway. Because sediment facies can be projected over larger areas than individual samples (due to assumptions based on physiography, or landforms) they represent an observational model of the distribution of sediments in an estuary. This model can be tested over time and space through comparison with additional past or future sample results. This approach provides a means to evaluate stability or change in the physical and biological conditions of the estuarine system. Initial comparison with past results for intertidal facies mapping and grain size analysis from grab samples showed remarkable stability over time for the MHW. The results of the SPI/PV mapping effort were cross-walked to the European Nature Information System (EUNIS) classification to provide a comparison of locally derived habitat mapping with European-standard habitat

Development of a Design Protocol : Sustainable Stabilization of Slope Using Recycled Plastic Pin in Mississippi

Science.gov (United States)

2017-10-14

The maritime and multimodal system is an integral part of the efficient movement of the nations freight, which includes around 25,000 miles of commercially navigable harbors, channels, and waterways; 4 million miles of public highways and roads; a...

In situ biomonitoring of juvenile Chinook salmon (Onchorhynchus tshawytscha) using biomarkers of chemical exposures and effects in a partially remediated urbanized waterway of the Puget Sound, WA

Energy Technology Data Exchange (ETDEWEB)

Browne, Eva [Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099 (United States); Kelley, Matthew; Zhou, Guo-Dong; He, Ling Yu; McDonald, Thomas; Wang, Shirley [Department of Environmental and Occupational Health, Texas A and M Health Science Center, College Station, TX 77843-1266 (United States); Duncan, Bruce [US Environmental Protection Agency, Region 10, 1200 Sixth Avenue, Seattle, WA 98101 (United States); Meador, James [Ecotoxicology Division, National Marine Fisheries Service, Seattle, WA 98105 (United States); Donnelly, Kirby [Department of Environmental and Occupational Health, Texas A and M Health Science Center, College Station, TX 77843-1266 (United States); Gallagher, Evan, E-mail: evang3@u.washington.edu [Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099 (United States)

2010-10-15

In situ biomonitoring has been used to assess the effects of pollution on aquatic species in heavily polluted waterways. In the current study, we used in situ biomonitoring in conjunction with molecular biomarker analysis to determine the effects of pollutant exposure in salmon caged in the Duwamish waterway, a Pacific Northwest Superfund site that has been subject to remediation. The Duwamish waterway is an important migratory route for Pacific salmon and has received historic inputs of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Juvenile pre-smolt Chinook salmon (Oncorhynchus tshawytscha) caged for 8 days in the three contaminated sites in close proximity within the Duwamish were analyzed for steady state hepatic mRNA expression of 7 exposure biomarker genes encompassing several gene families and known to be responsive to pollutants, including cytochrome P4501A (CYP1A) and CYP2K1, glutathione S-transferase {pi} class (GST-{pi}), microsomal GST (mGST), glutamylcysteine ligase catalytic subunit (GCLC), UDP-glucuronyltransferase family 1 (UDPGT), and type 2 deiodinase (type 2 DI, or D2). Quantitation of gene expression was accomplished by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in assays developed specifically for Chinook salmon genes. Gill PAH-DNA adducts were assessed as a chemical effects biomarker using {sup 32}P-postlabeling. The biomarkers in the field-caged fish were analyzed with respect to caged animals maintained at the hatchery receiving flow-through water. Chemical analysis of sediment samples from three field sampling sites revealed relatively high concentrations of total PAHs in one site (site B2, 6711 ng/g dry weight) and somewhat lower concentrations of PAHs in two adjacent sites (sites B3 and B4, 1482 and 1987 ng/g, respectively). In contrast, waterborne PAHs at all of the sampling sites were relatively low (<1 ng/L). Sediment PCBs at the sites ranged from a low of 421 ng/g at site B3

Channelling and electromagnetic radiation of channelling particles

International Nuclear Information System (INIS)

Kalashnikov, N.

1983-01-01

A brief description is presented of the channelling of charged particles between atoms in the crystal lattice. The specificities are discussed of the transverse motion of channelling particles as are the origin and properties of quasi-characteristic radiation of channelling particles which accompany transfers from one band of permissible energies of the transverse motion of channelling particles to the other. (B.S.)

Duwamish Waterways Navigation Improvement Study: Review of Existing Information on Land-Use Plans and Aquatic Resources in and Adjacent to the Duwamish River and Elliott Bay, Washington

Science.gov (United States)

1980-06-01

Species of Narine Aimals . U.S. Army Corps of Nngineers., Dredged Material Research Program, Waterways Experiment Station. Tech. Report D-77-24, 22 pages...shoreline substrates to hard substrates have been suggested. Juvenile salmon may be delayed by physical barriers, may suffer increased predation if...contents of each species at each station, food habit2 can be estimated. Stomach analysis of any potential predator species captured during the study may

Contribution of radioactive tracers to sediment transport study in fluvial flows

International Nuclear Information System (INIS)

Wilson Junior, G.

1995-01-01

The uses of radioactive tracers in sediment transport studies are presented in this report to evidence the importance of: Open channel researches, to describe field applications in waterways; Simultaneous utilization of classical methods and radiotracer techniques, in fluvial and estuarine environments; Development of radiotracers techniques applied in dynamic sedimentology. The report illustrated with some experiments carried out in Brazil and France, in open channel and natural flows. (author). 5 refs, 4 figs

Waterway e sviluppo del territorio: nuova mobilità e turismo sostenibile

Directory of Open Access Journals (Sweden)

Oriana Giovinazzi

2010-10-01

Full Text Available Spesso origine dei primi insediamenti urbani, i corsi d’acqua sono stati nei secoli fonte di sostentamento per le popolazioni e strumento di scambio tra genti e culture. Proprio per il loro scorrere attraverso il territorio, essi sono per definizione luoghi di relazione, di intersezione tra diverse realtà urbane dove si incontrano ambiente, architettura, pianificazione, trasporti ma anche arte, cultura e turismo. Per questa loro caratteristica, le vie d’acqua rappresentano una grande potenzialità per lo sviluppo del territorio sia in termini di mobilità – di merci e di persone - che di turismo sostenibile. La loro riqualificazione permette di recuperare il ruolo di spazio pubblico e di paesaggio rurale, urbano e turistico di qualità; luoghi di fruizione turistica, culturale, gastronomica e sportiva, quindi di qualità della vita. Dopo decenni di oblio, sollecitata dal rinnovato interesse verso questi assi e anche dalle direttive dell’Unione Europee, l’Italia e, in particolare il Nord del paese, muove i primi passi verso la valorizzazione delle waterway a fini turistico-culturali, aprendo nuove possibilità di sviluppo del territorio. Sia pur con ritardo rispetto ad altri Paesi, che da anni e in diverse forme valorizzano e “sfruttano” le vie d’acqua, si avverte anche in Italia un cambio di mentalità che vede nell’uso e nel recupero di tale risorsa uno strumento importante per garantire la sostenibilità ambientale ed economica e il recupero di una identità culturale quasi dimenticata.

An Effective Channel Allocation Scheme to Reduce Co-Channel and Adjacent Channel Interference for WMN Backhaul

International Nuclear Information System (INIS)

Abbasi, S.; Ismaili, I.A.; Khuhawar, F.Y.

2016-01-01

Two folded work presents channel allocation scheme sustaining channel orthogonality and channel spacing to reduce CCI (Co-Channel Interference) and ACI (Adjacent Channel Interference) for inter flow of an intra-flow link. Proposed scheme as a part of radio resource allocation is applied on infrastructure based backhaul of wireless mesh network using directional antennas. The proposed approach is applied separately on 2.4 and 5GHz bands. Interference of connectivity graph is modelled by strongly connected directed graph and greedy algorithms are used for channel allocation. We have used OPNET Modeller suite to simulate network models for this research. The proposed arrangement reduces the channel interference and increases system throughput. In this research, the influence of channel is computed in terms of network throughput and delay. (author)

Three dimensional computation of turbulent flow in meandering channels

Energy Technology Data Exchange (ETDEWEB)

Van Thinh Nguyen

2000-07-01

In this study a finite element calculation procedure together with two-equation turbulent model k-{epsilon} and mixing length are applied to the problem of simulating 3D turbulent flow in closed and open meandering channels. Near the wall a special approach is applied in order to overcome the weakness of the standard k-{epsilon} in the viscous sub-layer. A specialized shape function is used in the special near wall elements to capture accurately the strong variations of the mean flow variables in the viscosity-affected near wall region. Based on the analogy of water and air flows, a few characteristics of hydraulic problems can be examined in aerodynamic models, respectively. To study the relationships between an aerodynamic and a hydraulic model many experiments have been carried out by Federal Waterway Engineering and Research Institute of Karlsruhe, Germany. In order to test and examine the results of these physical models, an appropriated numerical model is necessary. The numerical mean will capture the limitations of the experimental setup. The similarity and the difference between an aerodynamic and a hydraulic model will be found out by the results of numerical computations and will be depicted in this study. Despite the presence of similarities between the flow in closed channels and the flow in open channels, it should be stated that the presence of a free surface in the open channel introduces serious complications to three dimensional computation. A new unknown, which represents the position of nodes on this free surface, is introduced. A special approach is required for solving this unknown. A procedure surface tracking is applied to the free surface boundary like a moving boundary. Grid nodes on the free surface are free to move in such a way that they belong to the spines, which are the generator lines to define the allowed motion of the nodes on the free surface. (orig.) [German] Die numerische Simulation ist heute ein wichtiges Hilfsmittel fuer die

Citizens and service channels: channel choice and channel management implications

NARCIS (Netherlands)

Pieterson, Willem Jan

2010-01-01

The arrival of electronic channels in the 1990s has had a huge impact on governmental service delivery. The new channels have led to many new opportunities to improve public service delivery, not only in terms of citizen satisfaction, but also in cost reduction for governmental agencies. However,

Single-channel kinetics of BK (Slo1 channels

Directory of Open Access Journals (Sweden)

Yanyan eGeng

2015-01-01

Full Text Available Single-channel kinetics has proven a powerful tool to reveal information about the gating mechanisms that control the opening and closing of ion channels. This introductory review focuses on the gating of large conductance Ca2+- and voltage-activated K+ (BK or Slo1 channels at the single-channel level. It starts with single-channel current records and progresses to presentation and analysis of single-channel data and the development of gating mechanisms in terms of discrete state Markov (DSM models. The DSM models are formulated in terms of the tetrameric modular structure of BK channels, consisting of a central transmembrane pore-gate domain (PGD attached to four surrounding transmembrane voltage sensing domains (VSD and a large intracellular cytosolic domain (CTD, also referred to as the gating ring. The modular structure and data analysis shows that the Ca2+ and voltage dependent gating considered separately can each be approximated by 10-state two-tiered models with 5 closed states on the upper tier and 5 open states on the lower tier. The modular structure and joint Ca2+ and voltage dependent gating are consistent with a 50 state two-tiered model with 25 closed states on the upper tier and 25 open states on the lower tier. Adding an additional tier of brief closed (flicker states to the 10-state or 50-state models improved the description of the gating. For fixed experimental conditions a channel would gate in only a subset of the potential number of states. The detected number of states and the correlations between adjacent interval durations are consistent with the tiered models. The examined models can account for the single-channel kinetics and the bursting behavior of gating. Ca2+ and voltage activate BK channels by predominantly increasing the effective opening rate of the channel with a smaller decrease in the effective closing rate. Ca2+ and depolarization thus activate by mainly destabilizing the closed states.

Digital 3D reconstruction of Agustin de Betancourt's historical heritage: the machine for cutting grass in waterways

Directory of Open Access Journals (Sweden)

José Ignacio Rojas-Sola

2016-05-01

Full Text Available Agustín de Betancourt y Molina was one of the most distinguished engineers of the eighteenth and nineteenth centuries with numerous contributions to various fields of engineering, including civil engineering. This research shows the process followed in the documentation of the cultural heritage of that Canary engineer, especially in the geometric documentation of a machine for cutting grass in waterways presented in England in 1795 after three years researching on theory of machines. The baseline information has been recovered from the Canary Orotava Foundation of History of Science who has spent years collecting information about the Project Betancourt, in particular, planimetric information as well as a small report on its operation and description of parts of machine. From this information, we have constructed a three dimensional (3D model using CAD techniques with the use of Solid Edge ST7 parametric software, which has enabled the team to create the 3D model as well as different detail plans and exploded views.

Examining the effects of hurricanes Matthew and Irma on water quality in the intracoastal waterway, St. Augustine, FL.

Science.gov (United States)

Ward, N. D.; Osborne, T.; Dye, T.; Julian, P.

2017-12-01

The last several years have been marked by a high incidence of Atlantic tropical cyclones making landfall as powerful hurricanes or tropical storms. For example, in 2016 Hurricane Matthew devastated parts of the Caribbean and the southeastern United States. In 2017, this region was further battered by hurricanes Irma and Maria. Here, we present water quality data collected in the intracoastal waterway near the Whitney Lab for Marine Bioscience during hurricanes Matthew and Irma, a region that experienced flooding during both storms. YSI Exo 2 sondes were deployed to measure pH, salinity, temperature, dissolved O2, fluorescent dissolved organic matter (fDOM), turbidity, and Chlorophyll-a (Chl-a) on a 15 minute interval. The Hurricane Matthew sonde deployment failed as soon as the storm hit, but revealed an interesting phenomenon leading up to the storm that was also observed during Irma. Salinity in the intracoastal waterway (off the Whitney Lab dock) typically varies from purely marine to 15-20 psu throughout the tidal cycle. However, several days before both storms approached the Florida coast (i.e. when they were near the Caribbean), the salinity signal became purely marine, overriding any tidal signal. Anecdotally, storm drains were already filled up to street level prior to the storm hitting, poising the region for immense flooding and storm surge. The opposite effect was observed after Irma moved past FL. Water became much fresher than normal for several days and it took almost a week to return to "normal" salinity tidal cycles. As both storms hit, turbidity increased by an order of magnitude for a several hour period. fDOM and O2 behaved similar to salinity during and after Irma, showing a mostly marine signal (e.g. higher O2, lower fDOM) in the lead up, and brief switch to more freshwater influence the week after the storm. Chl-a peaked several days after the storm, presumably due to mobilization of nutrient rich flood and waste waters and subsequent algae

[Synopsis about the hypothesis of "information channel" of channel-collateral system].

Science.gov (United States)

Chang, Xi-Lang

2008-10-01

The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

Channel box

International Nuclear Information System (INIS)

Tanabe, Akira.

1993-01-01

In a channel box of a BWR type reactor, protruding pads are disposed in axial position on the lateral side of a channel box opposing to a control rod and facing the outer side portion of the control rod in a reactor core loaded state. In the initial loading stage of fuel assemblies, channel fasteners and spacer pads are abutted against each other in the upper portion between the channel boxes sandwiching the control rod therebetween. Further, in the lower portion, a gap as a channel for the movement of the control rod is ensured by the support of fuel support metals. If the channel box is bent toward the control rod along with reactor operation, the pads are abutted against each other to always ensure the gap through which the control rod can move easily. Further, when the pads are brought into contact with each other, the bending deformation of the channel box is corrected by urging to each other. Thus, the control rod can always be moved smoothly to attain reactor safety operation. (N.H.)

Fine-scale population structure and riverscape genetics of brook trout (Salvelinus fontinalis) distributed continuously along headwater channel networks

Science.gov (United States)

Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.

2011-01-01

Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine-scale population structure and influence of stream habitat on individual-level genetic differentiation in brook trout (Salvelinus fontinalis) by genotyping eight microsatellite loci in 740 individuals in two headwater channel networks (7.7 and 4.4 km) in Connecticut, USA. A weak but statistically significant isolation-by-distance pattern was common in both sites. In the field, many tagged individuals were recaptured in the same 50-m reaches within a single field season (summer to fall). One study site was characterized with a hierarchical population structure, where seasonal barriers (natural falls of 1.5–2.5 m in height during summer base-flow condition) greatly reduced gene flow and perceptible spatial patterns emerged because of the presence of tributaries, each with a group of genetically distinguishable individuals. Genetic differentiation increased when pairs of individuals were separated by high stream gradient (steep channel slope) or warm stream temperature in this site, although the evidence of their influence was equivocal. In a second site, evidence for genetic clusters was weak at best, but genetic differentiation between individuals was positively correlated with number of tributary confluences. We concluded that the population-level movement of brook trout was limited in the study headwater stream networks, resulting in the fine-scale population structure (genetic clusters and clines) even at distances of a few kilometres, and gene flow was mitigated by ‘riverscape’ variables, particularly by physical barriers, waterway distance (i.e. isolation-by-distance) and the presence of tributaries.

Chemical concentrations in water and suspended sediment, Green River to Lower Duwamish Waterway near Seattle, Washington, 2016–17

Science.gov (United States)

Conn, Kathleen E.; Black, Robert W.; Peterson, Norman T.; Senter, Craig A.; Chapman, Elena A.

2018-01-05

From August 2016 to March 2017, the U.S. Geological Survey (USGS) collected representative samples of filtered and unfiltered water and suspended sediment (including the colloidal fraction) at USGS streamgage 12113390 (Duwamish River at Golf Course, at Tukwila, Washington) during 13 periods of differing flow conditions. Samples were analyzed by Washington-State-accredited laboratories for a large suite of compounds, including metals, dioxins/furans, semivolatile compounds including polycyclic aromatic hydrocarbons, butyltins, the 209 polychlorinated biphenyl (PCB) congeners, and total and dissolved organic carbon. Concurrent with the chemistry sampling, water-quality field parameters were measured, and representative water samples were collected and analyzed for river suspended-sediment concentration and particle-size distribution. The results provide new data that can be used to estimate sediment and chemical loads transported by the Green River to the Lower Duwamish Waterway.

33 CFR 165.731 - Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance Channel.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety/Security Zone: Cumberland... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED... Seventh Coast Guard District § 165.731 Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River...

Ion channeling

International Nuclear Information System (INIS)

Erramli, H.; Blondiaux, G.

1994-01-01

Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

Channel characteristics and coordination in three-echelon dual-channel supply chain

Science.gov (United States)

Saha, Subrata

2016-02-01

We explore the impact of channel structure on the manufacturer, the distributer, the retailer and the entire supply chain by considering three different channel structures in radiance of with and without coordination. These structures include a traditional retail channel and two manufacturer direct channels with and without consistent pricing. By comparing the performance of the manufacturer, the distributer and the retailer, and the entire supply chain in three different supply chain structures, it is established analytically that, under some conditions, a dual channel can outperform a single retail channel; as a consequence, a coordination mechanism is developed that not only coordinates the dual channel but also outperforms the non-cooperative single retail channel. All the analytical results are further analysed through numerical examples.

MONETARY TRANSMISSION CHANNELS IN ROMANIA – THE CREDIT CHANNEL

Directory of Open Access Journals (Sweden)

Magdalena RĂDULESCU

2009-12-01

Full Text Available The theoretical – intuitive analysis applied to the segment of monetary transmission evidences the fact that forming the traditional monetary impulses transmission channels are in a starting phase due to the long financial non – intermediary process which Romanian economy had known. In these conditions, the exchange rate channel, and also NBR currency purchases was, for a long time, an important way through which monetary authorities actions influenced macro economical behaviors. But starting with 2000, it is observed a credit channel reactivation and, especially, interest rate channel. Anyhow, the credit channel continues to be undermined by the existence of liquidity surplus within the system, by the phenomena of substitution of national currency credit with currency credits, and also moral hazardous displays. Albeit some of these phenomena also affect the interest rate channel, its role in sending monetary policy impulses is in a continuous progress. Apparently, it acts by way of nominal interest rates, their real level seeming less relevant. Once with remaking the two traditional channels, the companies and households balance is configured and consolidated, which shall potentate in the future the efficiency of the monetary policy. This paper analyses the credit channel in Romania, through an unrestricted VAR analysis.. It shows the responses of exchange rate, inflation rate, GDP, interest rate, imports and exports to a shock on non-governmental credit

ZnO-channel thin-film transistors: Channel mobility

International Nuclear Information System (INIS)

Hoffman, R.L.

2004-01-01

ZnO-channel thin-film transistor (TFT) test structures are fabricated using a bottom-gate structure on thermally oxidized Si; ZnO is deposited via RF sputtering from an oxide target, with an unheated substrate. Electrical characteristics are evaluated, with particular attention given to the extraction and interpretation of transistor channel mobility. ZnO-channel TFT mobility exhibits severe deviation from that assumed by ideal TFT models; mobility extraction methodology must accordingly be recast so as to provide useful insight into device operation. Two mobility metrics, μ avg and μ inc , are developed and proposed as relevant tools in the characterization of nonideal TFTs. These mobility metrics are employed to characterize the ZnO-channel TFTs reported herein; values for μ inc as high as 25 cm2/V s are measured, comprising a substantial increase in ZnO-channel TFT mobility as compared to previously reported performance for such devices

Disguising quantum channels by mixing and channel distance trade-off

International Nuclear Information System (INIS)

Fung, Chi-Hang Fred; Chau, H F

2014-01-01

We consider the reverse problem of the distinguishability of two quantum channels, which we call the disguising problem. Given two quantum channels, the goal here is to make the two channels identical by mixing with some other channels with minimal mixing probabilities. This quantifies how much one channel can disguise as the other. In addition, the possibility to trade-off between the two mixing probabilities allows one channel to be more preserved (less mixed) at the expense of the other. We derive lower- and upper-bounds of the trade-off curve and apply them to a few example channels. Optimal trade-off is obtained in one example. We relate the disguising problem and the distinguishability problem by showing that the former can lower and upper bound the diamond norm. We also show that the disguising problem gives an upper-bound on the key generation rate in quantum cryptography. (paper)

Compound Wiretap Channels

Directory of Open Access Journals (Sweden)

Kramer Gerhard

2009-01-01

Full Text Available Abstract This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom ( are derived for the degraded case with one receiver. Schemes to achieve the for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable is given for the general case.

ATP Release Channels

Directory of Open Access Journals (Sweden)

Akiyuki Taruno

2018-03-01

Full Text Available Adenosine triphosphate (ATP has been well established as an important extracellular ligand of autocrine signaling, intercellular communication, and neurotransmission with numerous physiological and pathophysiological roles. In addition to the classical exocytosis, non-vesicular mechanisms of cellular ATP release have been demonstrated in many cell types. Although large and negatively charged ATP molecules cannot diffuse across the lipid bilayer of the plasma membrane, conductive ATP release from the cytosol into the extracellular space is possible through ATP-permeable channels. Such channels must possess two minimum qualifications for ATP permeation: anion permeability and a large ion-conducting pore. Currently, five groups of channels are acknowledged as ATP-release channels: connexin hemichannels, pannexin 1, calcium homeostasis modulator 1 (CALHM1, volume-regulated anion channels (VRACs, also known as volume-sensitive outwardly rectifying (VSOR anion channels, and maxi-anion channels (MACs. Recently, major breakthroughs have been made in the field by molecular identification of CALHM1 as the action potential-dependent ATP-release channel in taste bud cells, LRRC8s as components of VRACs, and SLCO2A1 as a core subunit of MACs. Here, the function and physiological roles of these five groups of ATP-release channels are summarized, along with a discussion on the future implications of understanding these channels.

Spark Channels

Energy Technology Data Exchange (ETDEWEB)

Haydon, S. C. [Department of Physics, University of New England, Armidale, NSW (Australia)

1968-04-15

A brief summary is given of the principal methods used for initiating spark channels and the various highly time-resolved techniques developed recently for studies with nanosecond resolution. The importance of the percentage overvoltage in determining the early history and subsequent development of the various phases of the growth of the spark channel is discussed. An account is then given of the recent photographic, oscillographic and spectroscopic investigations of spark channels initiated by co-axial cable discharges of spark gaps at low [{approx} 1%] overvoltages. The phenomena observed in the development of the immediate post-breakdown phase, the diffuse glow structure, the growth of the luminous filament and the final formation of the spark channel in hydrogen are described. A brief account is also given of the salient features emerging from corresponding studies of highly overvolted spark gaps in which the spark channel develops from single avalanche conditions. The essential differences between the two types of channel formation are summarized and possible explanations of the general features are indicated. (author)

Joint source/channel coding of scalable video over noisy channels

Energy Technology Data Exchange (ETDEWEB)

Cheung, G.; Zakhor, A. [Department of Electrical Engineering and Computer Sciences University of California Berkeley, California94720 (United States)

1997-01-01

We propose an optimal bit allocation strategy for a joint source/channel video codec over noisy channel when the channel state is assumed to be known. Our approach is to partition source and channel coding bits in such a way that the expected distortion is minimized. The particular source coding algorithm we use is rate scalable and is based on 3D subband coding with multi-rate quantization. We show that using this strategy, transmission of video over very noisy channels still renders acceptable visual quality, and outperforms schemes that use equal error protection only. The flexibility of the algorithm also permits the bit allocation to be selected optimally when the channel state is in the form of a probability distribution instead of a deterministic state. {copyright} {ital 1997 American Institute of Physics.}

Innovative methods to reduce salt water intrusion in harbours

Science.gov (United States)

Groenenboom, J.; Uittenbogaard, R.; Hulsen, L.; van der Kaaij, T.; Kielen, N.

2017-12-01

The availability of fresh water in densely populated estuarine environments will in the future more often be threatened due to both human (e.g. channel deepening) and natural (sea-level rise, storm surges, extremely low river discharges) causes. Here, the salt water intrusion into the New Waterway, the main navigation channel of the port of Rotterdam, is used as a case study to elaborate on two innovative ways to mitigate the effects of salt water intrusion. The first method is based on the concept that vertical mixing of a salt wedge reduces its intrusion length. The idea is to equip a vessel with cranes that hold perforated tubes close to the bed alongside the vessel. By connecting compressors to the perforated tubes, a bubble screen with an adjustable vertical location can be created. Since the horizontal location of the bubble screens is not fixed, the vessel can sail in the vicinity of the moving salt wedge therewith increasing the effectiveness of the method. Another advantage of this intervention is that it can be deployed temporarily when the urgency for the prevention of salt water intrusion is high. The second method originates from the Port of Rotterdam Authority and is inspired by a small bypass that is present between two parallel channels (New Waterway and Caland Canal) connecting the North Sea to the Port of Rotterdam. Due to the different hydrodynamic characteristics of the hinterland of both channels, a difference in salinity and water level is present between both ends of the bypass. As a result, a lateral inflow of water into the New Waterway occurs at the same moment that the flood velocities transport saline water landwards. The lateral inflow of water into this channel has no momentum in the landward direction and therefore decreases the landward flow velocity and therewith the salt water intrusion. In addition, the inflow drives a vertical circulation that mixes the water column close to the bypass. Similar to the bubble screens mentioned

Compound Wiretap Channels

Directory of Open Access Journals (Sweden)

Shlomo Shamai (Shitz

2009-01-01

Full Text Available This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom (s.d.o.f. are derived for the degraded case with one receiver. Schemes to achieve the s.d.o.f. for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable s.d.o.f. is given for the general case.

Quantum Channels With Memory

International Nuclear Information System (INIS)

Rybar, T.

2012-01-01

Quantum memory channels represent a very general, yet simple and comprehensible model for causal processes. As such they have attracted considerable research interest, mostly aimed on their transfer capabilities and structure properties. Most notably it was shown that memory channels can be implemented via physically naturally motivated collision models. We also define the concept of repeatable channels and show that only unital channels can be implemented repeat ably with pure memory channels. In the special case of qubit channels we also show that every unital qubit channel has a repeatable implementation. We also briefly explore the possibilities of stroboscopical simulation of channels and show that all random unitary channels can be stroboscopically simulated. Particularly in qubit case, all indivisible qubit channels are also random unitary, hence for qubit all indivisible channels can be stroboscopically simulated. Memory channels also naturally capture the framework of correlated experiments. We develop methods to gather and interpret data obtained in such setting and in detail examine the two qubit case. We also show that for control unitary interactions the measured data will never contradict a simple unitary evolution. Thus no memory effects can be spotted then. (author)

Mimicking multi-channel scattering with single-channel approaches

OpenAIRE

Grishkevich, Sergey; Schneider, Philipp-Immanuel; Vanne, Yulian V.; Saenz, Alejandro

2009-01-01

The collision of two atoms is an intrinsic multi-channel (MC) problem as becomes especially obvious in the presence of Feshbach resonances. Due to its complexity, however, single-channel (SC) approximations, which reproduce the long-range behavior of the open channel, are often applied in calculations. In this work the complete MC problem is solved numerically for the magnetic Feshbach resonances (MFRs) in collisions between generic ultracold 6Li and 87Rb atoms in the ground state and in the ...

75 FR 65232 - Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX

Science.gov (United States)

2010-10-22

... Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not create an environmental risk to health or risk to safety that may disproportionately affect children... for which the Captain of the Port, Port Arthur deems enhanced security measures necessary. In addition...

75 FR 29695 - Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX

Science.gov (United States)

2010-05-27

... rule under Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and would not create an environmental risk to... proposes to establish moving security zones for certain vessels for which the Captain of the Port, Port...

Fine Channel Networks

Science.gov (United States)

1997-01-01

A color image of fine channel networks on Mars; north toward top. The scene shows heavily cratered highlands dissected by dendritic open channel networks that dissect steep slopes of impact crater walls. This image is a composite of Viking high-resolution images in black and white and low-resolution images in color. The image extends from latitude 9 degrees S. to 5 degrees S. and from longitude 312 degrees to 320 degrees; Mercator projection. The dendritic pattern of the fine channels and their location on steep slopes leads to the interpretation that these are runoff channels. The restriction of these types of channels to ancient highland rocks suggests that these channels are old and date from a time on Mars when conditions existed for precipitation to actively erode rocks. After the channels reach a low plain, they appear to end. Termination may have resulted from burial by younger deposits or perhaps the flows percolated into the surface materials and continued underground.

Volume Regulated Channels

DEFF Research Database (Denmark)

Klausen, Thomas Kjær

of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

A channel profile analyser

International Nuclear Information System (INIS)

Gobbur, S.G.

1983-01-01

It is well understood that due to the wide band noise present in a nuclear analog-to-digital converter, events at the boundaries of adjacent channels are shared. It is a difficult and laborious process to exactly find out the shape of the channels at the boundaries. A simple scheme has been developed for the direct display of channel shape of any type of ADC on a cathode ray oscilliscope display. This has been accomplished by sequentially incrementing the reference voltage of a precision pulse generator by a fraction of a channel and storing ADC data in alternative memory locations of a multichannel pulse height analyser. Alternative channels are needed due to the sharing at the boundaries of channels. In the flat region of the profile alternate memory locations are channels with zero counts and channels with the full scale counts. At the boundaries all memory locations will have counts. The shape of this is a direct display of the channel boundaries. (orig.)

Ion channels in plants.

Science.gov (United States)

Hedrich, Rainer

2012-10-01

Since the first recordings of single potassium channel activities in the plasma membrane of guard cells more than 25 years ago, patch-clamp studies discovered a variety of ion channels in all cell types and plant species under inspection. Their properties differed in a cell type- and cell membrane-dependent manner. Guard cells, for which the existence of plant potassium channels was initially documented, advanced to a versatile model system for studying plant ion channel structure, function, and physiology. Interestingly, one of the first identified potassium-channel genes encoding the Shaker-type channel KAT1 was shown to be highly expressed in guard cells. KAT1-type channels from Arabidopsis thaliana and its homologs from other species were found to encode the K(+)-selective inward rectifiers that had already been recorded in early patch-clamp studies with guard cells. Within the genome era, additional Arabidopsis Shaker-type channels appeared. All nine members of the Arabidopsis Shaker family are localized at the plasma membrane, where they either operate as inward rectifiers, outward rectifiers, weak voltage-dependent channels, or electrically silent, but modulatory subunits. The vacuole membrane, in contrast, harbors a set of two-pore K(+) channels. Just very recently, two plant anion channel families of the SLAC/SLAH and ALMT/QUAC type were identified. SLAC1/SLAH3 and QUAC1 are expressed in guard cells and mediate Slow- and Rapid-type anion currents, respectively, that are involved in volume and turgor regulation. Anion channels in guard cells and other plant cells are key targets within often complex signaling networks. Here, the present knowledge is reviewed for the plant ion channel biology. Special emphasis is drawn to the molecular mechanisms of channel regulation, in the context of model systems and in the light of evolution.

Channel and Timeslot Co-Scheduling with Minimal Channel Switching for Data Aggregation in MWSNs

Directory of Open Access Journals (Sweden)

Sanggil Yeoum

2017-05-01

Full Text Available Collision-free transmission and efficient data transfer between nodes can be achieved through a set of channels in multichannel wireless sensor networks (MWSNs. While using multiple channels, we have to carefully consider channel interference, channel and time slot (resources optimization, channel switching delay, and energy consumption. Since sensor nodes operate on low battery power, the energy consumed in channel switching becomes an important challenge. In this paper, we propose channel and time slot scheduling for minimal channel switching in MWSNs, while achieving efficient and collision-free transmission between nodes. The proposed scheme constructs a duty-cycled tree while reducing the amount of channel switching. As a next step, collision-free time slots are assigned to every node based on the minimal data collection delay. The experimental results demonstrate that the validity of our scheme reduces the amount of channel switching by 17.5%, reduces energy consumption for channel switching by 28%, and reduces the schedule length by 46%, as compared to the existing schemes.

Surface channeling

International Nuclear Information System (INIS)

Sizmann, R.; Varelas, C.

1976-01-01

There is experimental evidence that swift light ions incident at small angles towards single crystalline surfaces can lose an appreciable fraction of their kinetic energy during reflection. It is shown that these projectiles penetrate into the bulk surface region of the crystal. They can travel as channeled particles along long paths through the solid (surface channeling). The angular distribution and the depth history of the re-emerged projectiles are investigated by computer simulations. A considerable fraction of the penetrating projectiles re-emerges from the crystal with constant transverse energy if the angle of incidence is smaller than the critical angle for axial channeling. Analytical formulae are derived based on a diffusion model for surface channeling. A comparison with experimental data exhibits the relevance of the analytical solutions. (Auth.)

An information-guided channel-hopping scheme for block-fading channels with estimation errors

KAUST Repository

Yang, Yuli

2010-12-01

Information-guided channel-hopping technique employing multiple transmit antennas was previously proposed for supporting high data rate transmission over fading channels. This scheme achieves higher data rates than some mature schemes, such as the well-known cyclic transmit antenna selection and space-time block coding, by exploiting the independence character of multiple channels, which effectively results in having an additional information transmitting channel. Moreover, maximum likelihood decoding may be performed by simply decoupling the signals conveyed by the different mapping methods. In this paper, we investigate the achievable spectral efficiency of this scheme in the case of having channel estimation errors, with optimum pilot overhead for minimum meansquare error channel estimation, when transmitting over blockfading channels. Our numerical results further substantiate the robustness of the presented scheme, even with imperfect channel state information. ©2010 IEEE.

Charged and Neutral Particles Channeling Phenomena Channeling 2008

Science.gov (United States)

Dabagov, Sultan B.; Palumbo, Luigi

2010-04-01

On the discovery of coherent Bremsstrahlung in a single crystal at the Frascati National Laboratories / C. Barbiellini, G. P. Murtas and S. B. Dabagov -- Advances in coherent Bremsstrahlung and LPM-effect studies (to the lOOth anniversary from the birth of L. D. Landau) / N. F. Shul'ga -- Spectra of radiation and created particles at intermediate energy in oriented crystal taking into account energy loss / V. N. Baier and V. M. Katkov -- The coherent Bremsstrahlung beam at MAX-lab facility / K. Fissum ... [et al.] -- Radiation from thin, structured targets (CERN NA63) / A. Dizdar -- Hard incoherent radiation in thick crystals / N. F. Shul'ga, V. V. Syshchenko and A. I. Tarnovsky -- Coherent Bremsstrahlung in periodically deformed crystals with a complex base / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Induction of coherent x-ray Bremsstrahlung in crystals under the influence of acoustic waves / A. R. Mkrtchyan and V. V. Parazian -- Coherent processes in bent single crystals / V. A. Maisheev -- Experimental and theoretical investigation of complete transfer phenomenon for media with various heat exchange coefficients / A. R. Mkrtchyan, A. E. Movsisyan and V. R. Kocharyan -- Coherent pair production in crystals / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Negative particle planar and axial channeling and channeling collimation / R. A. Carrigan, Jr. -- CERN crystal-based collimation in modern hadron colliders / W. Scandale -- Studies and application of bent crystals for beam steering at 70 GeV IHEP accelerator / A. G. Afonin ... [et al.] -- Crystal collimation studies at the Tevatron (T-980) / N. V. Mokhov ... [et al.] -- Fabrication of crystals for channeling of particles in accellerators / A. Mazzolari ... [et al.] -- New possibilities to facilitate collimation of both positively and negatively charged particle beams by crystals / V. Guidi, A. Mazzolari and V. V. Tikhomirov -- Increase of probability of particle capture into the channeling

Potassium channels in brain mitochondria.

Science.gov (United States)

Bednarczyk, Piotr

2009-01-01

Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

Channel allocation and rate adaptation for relayed transmission over correlated fading channels

KAUST Repository

Hwang, Kyusung

2009-09-01

We consider, in this paper, channel allocation and rate adaptation scheme for relayed transmission over correlated fading channels via cross-layer design. Specifically, jointly considering the data link layer buffer occupancy and channel quality at both the source and relay nodes, we develop an optimal channel allocation and rate adaptation policy for a dual-hop relayed transmission. As such the overall transmit power for the relayed system is minimized while a target packet dropping rate (PDR) due to buffer over flows is guaranteed. In order to find such an optimal policy, the channel allocation and rate adaptation transmission framework is formulated as a constraint Markov decision process (CMDP). The PDR performance of the optimal policy is compared with that of two conventional suboptimal schemes, namely the channel quality based and the buffer occupancy based channel allocation schemes. Numerical results show that for a given power budget, the optimal scheme requires significantly less power than the conventional schemes in order to maintain a target PDR. ©2009 IEEE.

Little River Inlet Navigation Project, Brunswick County, North Carolina and Horry County, South Carolina. Revision.

Science.gov (United States)

1977-06-01

to gr(ater physiological stress than the Adjacent waterways. In addition to the nine stations in I1,, inner channel, eight others were occupied in...rmn’, u t I,,’ i on. U. S. G, t. Print in Offic , Washington, D.C. 3 . . Cumin rc Nat i una I i i c i\\ tiospher i c Adri ii st , r , . ) 0 . Tidt d , i

On the secrecy capacity of the MISO wiretap channel under imperfect channel estimation

KAUST Repository

Rezki, Zouheir; Alomair, Basel; Alouini, Mohamed-Slim

2014-01-01

We consider a wiretap channel consisting of a source with multiple antennas, a legitimate receiver and an eavesdropper with a single antenna each. The channels between the source and the receivers undergo fast fading. We assume that the transmitter, in addition to the statistics of both channels, is only aware of a noisy version of the CSI to the legitimate receiver referred to as main channel. The legitimate receiver is aware of both its instantaneous channel gain and the transmitter's estimate of the main channel. On the other hand, the eavesdropper's receiver, in addition to its instantaneous channel realization, is aware of the actual main CSI and the transmitter's estimate as well. While the capacity of this channel is still open even with perfect CSI at the transmitter, we provide in this paper upper and lower bounds on the secrecy capacity. The upper bound is tighter than the one corresponding to perfect main CSI and the gap between the two upper bounds is characterized in function of the channel estimation error variance, at high-SNR. Furthermore, we show that our upper and lower bounds coincide in the case of no main CSI providing a trivial secrecy capacity.

A linearization of quantum channels

Science.gov (United States)

Crowder, Tanner

2015-06-01

Because the quantum channels form a compact, convex set, we can express any quantum channel as a convex combination of extremal channels. We give a Euclidean representation for the channels whose inverses are also valid channels; these are a subset of the extreme points. They form a compact, connected Lie group, and we calculate its Lie algebra. Lastly, we calculate a maximal torus for the group and provide a constructive approach to decomposing any invertible channel into a product of elementary channels.

Channel Characteristics and Transmission Performance for Various Channel Configurations at 60 GHz

Directory of Open Access Journals (Sweden)

Yang Haibing

2007-01-01

Full Text Available Extensive measurements are conducted in room environments at 60 GHz to analyze the channel characteristics for various channel configurations. Channel parameters retrieved from measurements are presented and analyzed based on generic channel models. Particularly, a simple single-cluster model is applied for the parameter retrieval and performance evaluation. By this model, power delay profiles are simply described by a -factor, a root-mean-squared delay spread, and a shape parameter. The considered channels are configured with the combination of omnidirectional, fan-beam, and pencil-beam antennas at transmitter and receiver sides. Both line-of-sight (LOS and non-LOS (NLOS channels are considered. Further, to evaluate the transmission performance, we analyze the link budget in the considered environments, then design and simulate an OFDM system with a data rate of 2 Gbps to compare the bit-error-rate (BER performance by using the measured and modeled channels. Both coded and uncoded OFDM systems are simulated. It is observed that the BER performance agrees well for the measured and modeled channels. In addition, directive configurations can provide sufficient link margins and BER performance for high data rate communications. To increase the coverage and performance in the NLOS area, it is preferable to apply directive antennas.

Channel Characteristics and Transmission Performance for Various Channel Configurations at 60 GHz

Directory of Open Access Journals (Sweden)

Haibing Yang

2007-05-01

Full Text Available Extensive measurements are conducted in room environments at 60 GHz to analyze the channel characteristics for various channel configurations. Channel parameters retrieved from measurements are presented and analyzed based on generic channel models. Particularly, a simple single-cluster model is applied for the parameter retrieval and performance evaluation. By this model, power delay profiles are simply described by a K-factor, a root-mean-squared delay spread, and a shape parameter. The considered channels are configured with the combination of omnidirectional, fan-beam, and pencil-beam antennas at transmitter and receiver sides. Both line-of-sight (LOS and non-LOS (NLOS channels are considered. Further, to evaluate the transmission performance, we analyze the link budget in the considered environments, then design and simulate an OFDM system with a data rate of 2 Gbps to compare the bit-error-rate (BER performance by using the measured and modeled channels. Both coded and uncoded OFDM systems are simulated. It is observed that the BER performance agrees well for the measured and modeled channels. In addition, directive configurations can provide sufficient link margins and BER performance for high data rate communications. To increase the coverage and performance in the NLOS area, it is preferable to apply directive antennas.

Biomarker responses and PAH ratios in fish inhabiting an estuarine urban waterway.

Science.gov (United States)

Duarte, Rafael Mendonça; Sadauskas-Henrique, Helen; de Almeida-Val, Vera Maria Fonseca; Val, Adalberto Luis; Nice, Helen Elizabeth; Gagnon, Marthe Monique

2017-10-01

Many cities worldwide are established adjacent to estuaries and their catchments resulting in estuarine contamination due to intense anthropogenic activities. The aim of this study was to evaluate if fish living in an estuarine urban waterway were affected by contamination, via the measurement of a suite of biomarkers of fish health. Black bream (Acanthopagrus butcheri) were sampled in a small urban embayment and a suite of biomarkers of fish health measured. These were condition factor (CF), liver somatic index (LSI), gonadosomatic index (GSI), hepatic EROD activity, polycyclic aromatic hydrocarbon (PAH) biliary metabolites, serum sorbitol dehydrogenase (s-SDH) and branchial enzymes cytochrome C oxidase (CCO), and lactate dehydrogenase (LDH) activities. The biomarkers of exposure EROD activity, and pyrene- and B(a)P-type biliary metabolites confirmed current or recent exposure of the fish and that fish were metabolizing contaminants. Relative to a reference site, LSI was higher in fish collected in the urban inlet as was the metabolic enzyme LDH activity. CF, GSI, s-SDH, CCO, and naphthalene-type metabolites were at similar levels in the urban inlet relative to the reference site. PAH biliary metabolite ratios of high-molecular-weight to low-molecular-weight suggest that fish from the urban inlet were exposed to pyrogenic PAHs, likely from legacy contamination and road runoff entering the embayment. Similarly, the sediment PAH ratios and the freshness indices suggested legacy contamination of a pyrogenic source, likely originating from the adjacent historic gasworks site and a degree of contamination of petrogenic nature entering the inlet via storm water discharge. Biomarkers of exposure and effect confirmed that black bream collected in the Claisebrook Cove inlet, Western Australia, are currently exposed to contamination and are experiencing metabolic perturbations not observed in fish collected at a nearby reference site. © 2017 Wiley Periodicals, Inc.

Volume of the space of qubit-qubit channels and state transformations under random quantum channels

OpenAIRE

Lovas, Attila; Andai, Attila

2017-01-01

The simplest building blocks for quantum computations are the qubit-qubit quantum channels. In this paper, we analyze the structure of these channels via their Choi representation. The restriction of a quantum channel to the space of classical states (i.e. probability distributions) is called the underlying classical channel. The structure of quantum channels over a fixed classical channel is studied, the volume of general and unital qubit channels with respect to the Lebesgue measure is comp...

Performance Analysis of Iterative Channel Estimation and Multiuser Detection in Multipath DS-CDMA Channels

Science.gov (United States)

Li, Husheng; Betz, Sharon M.; Poor, H. Vincent

2007-05-01

This paper examines the performance of decision feedback based iterative channel estimation and multiuser detection in channel coded aperiodic DS-CDMA systems operating over multipath fading channels. First, explicit expressions describing the performance of channel estimation and parallel interference cancellation based multiuser detection are developed. These results are then combined to characterize the evolution of the performance of a system that iterates among channel estimation, multiuser detection and channel decoding. Sufficient conditions for convergence of this system to a unique fixed point are developed.

On the secrecy capacity of the MISO wiretap channel under imperfect channel estimation

KAUST Repository

Rezki, Zouheir

2014-12-01

We consider a wiretap channel consisting of a source with multiple antennas, a legitimate receiver and an eavesdropper with a single antenna each. The channels between the source and the receivers undergo fast fading. We assume that the transmitter, in addition to the statistics of both channels, is only aware of a noisy version of the CSI to the legitimate receiver referred to as main channel. The legitimate receiver is aware of both its instantaneous channel gain and the transmitter\\'s estimate of the main channel. On the other hand, the eavesdropper\\'s receiver, in addition to its instantaneous channel realization, is aware of the actual main CSI and the transmitter\\'s estimate as well. While the capacity of this channel is still open even with perfect CSI at the transmitter, we provide in this paper upper and lower bounds on the secrecy capacity. The upper bound is tighter than the one corresponding to perfect main CSI and the gap between the two upper bounds is characterized in function of the channel estimation error variance, at high-SNR. Furthermore, we show that our upper and lower bounds coincide in the case of no main CSI providing a trivial secrecy capacity.

Channel electron multipliers

International Nuclear Information System (INIS)

Seidman, A.; Avrahami, Z.; Sheinfux, B.; Grinberg, J.

1976-01-01

A channel electron multiplier is described having a tubular wall coated with a secondary-electron emitting material and including an electric field for accelerating the electrons, the electric field comprising a plurality of low-resistive conductive rings each alternating with a high-resistive insulating ring. The thickness of the low-resistive rings is many times larger than that of the high-resistive rings, being in the order of tens of microns for the low-resistive rings and at least one order of magnitude lower for the high-resistive rings; and the diameter of the channel tubular walls is also many times larger than the thickness of the high-resistive rings. Both single-channel and multiple-channel electron multipliers are described. A very important advantage, particularly in making multiple-channel multipliers, is the simplicity of the procedure that may be used in constructing such multipliers. Other operational advantages are described

San Francisco Bay to Stockton, California Project. Environmental Impact Statement. John F. Baldwin Ship Channel. Phase II. Richmond Harbor Approach.

Science.gov (United States)

1984-05-01

Fish and Game and Deelopie" Cou , rtment of Forestry soIIa Waste man acer ~e- r. A-3 State Coasta Conerar rtment of Boating and Waterways State ands...crude going through California refineries comes from three sources: California, Alaska, and Indonesia/ Malaysia . The Alaskan and Indonesian/Malaysian crude

Coherifying quantum channels

Science.gov (United States)

Korzekwa, Kamil; Czachórski, Stanisław; Puchała, Zbigniew; Życzkowski, Karol

2018-04-01

Is it always possible to explain random stochastic transitions between states of a finite-dimensional system as arising from the deterministic quantum evolution of the system? If not, then what is the minimal amount of randomness required by quantum theory to explain a given stochastic process? Here, we address this problem by studying possible coherifications of a quantum channel Φ, i.e., we look for channels {{{Φ }}}{ \\mathcal C } that induce the same classical transitions T, but are ‘more coherent’. To quantify the coherence of a channel Φ we measure the coherence of the corresponding Jamiołkowski state J Φ. We show that the classical transition matrix T can be coherified to reversible unitary dynamics if and only if T is unistochastic. Otherwise the Jamiołkowski state {J}{{Φ }}{ \\mathcal C } of the optimally coherified channel is mixed, and the dynamics must necessarily be irreversible. To assess the extent to which an optimal process {{{Φ }}}{ \\mathcal C } is indeterministic we find explicit bounds on the entropy and purity of {J}{{Φ }}{ \\mathcal C }, and relate the latter to the unitarity of {{{Φ }}}{ \\mathcal C }. We also find optimal coherifications for several classes of channels, including all one-qubit channels. Finally, we provide a non-optimal coherification procedure that works for an arbitrary channel Φ and reduces its rank (the minimal number of required Kraus operators) from {d}2 to d.

The Extended-Window Channel Estimator for Iterative Channel-and-Symbol Estimation

Directory of Open Access Journals (Sweden)

Barry John R

2005-01-01

Full Text Available The application of the expectation-maximization (EM algorithm to channel estimation results in a well-known iterative channel-and-symbol estimator (ICSE. The EM-ICSE iterates between a symbol estimator based on the forward-backward recursion (BCJR equalizer and a channel estimator, and may provide approximate maximum-likelihood blind or semiblind channel estimates. Nevertheless, the EM-ICSE has high complexity, and it is prone to misconvergence. In this paper, we propose the extended-window (EW estimator, a novel channel estimator for ICSE that can be used with any soft-output symbol estimator. Therefore, the symbol estimator may be chosen according to performance or complexity specifications. We show that the EW-ICSE, an ICSE that uses the EW estimator and the BCJR equalizer, is less complex and less susceptible to misconvergence than the EM-ICSE. Simulation results reveal that the EW-ICSE may converge faster than the EM-ICSE.

Channel identification machines.

Science.gov (United States)

Lazar, Aurel A; Slutskiy, Yevgeniy B

2012-01-01

We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s) onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS) with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.

Channel Identification Machines

Directory of Open Access Journals (Sweden)

Aurel A. Lazar

2012-01-01

Full Text Available We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.

CHANNEL ESTIMATION TECHNIQUE

DEFF Research Database (Denmark)

2015-01-01

A method includes determining a sequence of first coefficient estimates of a communication channel based on a sequence of pilots arranged according to a known pilot pattern and based on a receive signal, wherein the receive signal is based on the sequence of pilots transmitted over the communicat......A method includes determining a sequence of first coefficient estimates of a communication channel based on a sequence of pilots arranged according to a known pilot pattern and based on a receive signal, wherein the receive signal is based on the sequence of pilots transmitted over...... the communication channel. The method further includes determining a sequence of second coefficient estimates of the communication channel based on a decomposition of the first coefficient estimates in a dictionary matrix and a sparse vector of the second coefficient estimates, the dictionary matrix including...... filter characteristics of at least one known transceiver filter arranged in the communication channel....

Research on Cost Information Sharing and Channel Choice in a Dual-Channel Supply Chain

Directory of Open Access Journals (Sweden)

Huihui Liu

2016-01-01

Full Text Available Many studies examine information sharing in an uncertain demand environment in a supply chain. However there is little literature on cost information sharing in a dual-channel structure consisting of a retail channel and a direct sales channel. Assuming that the retail sale cost and direct sale cost are random variables with a general distribution, the paper investigates the retailer’s choice on cost information sharing in a Bertrand competition model. Based on the equilibrium outcome of information sharing, the manufacturer’s channel choice is discussed in detail. Our paper provides several interesting conclusions. In both single- and dual-channel structures, the retailer has little motivation to share its private cost information which is verified to be valuable for the manufacturer. When the cost correlation between the two channels increases, our analyses show that the manufacturer’s profit improves. However, when channel choice is involved, the value of information could play a different role. The paper finds that a dual-channel structure can benefit the manufacturer only when the cost correlation is sufficiently low. In addition, if the cost correlation is weak, the cost fluctuation will bring out the advantage of a dual-channel structure and adding a new direct channel will help in risk pooling.

Use of navigation channels by Lake Sturgeon: Does channelization increase vulnerability of fish to ship strikes?

Directory of Open Access Journals (Sweden)

Darryl W Hondorp

Full Text Available Channelization for navigation and flood control has altered the hydrology and bathymetry of many large rivers with unknown consequences for fish species that undergo riverine migrations. In this study, we investigated whether altered flow distributions and bathymetry associated with channelization attracted migrating Lake Sturgeon (Acipenser fulvescens into commercial navigation channels, potentially increasing their exposure to ship strikes. To address this question, we quantified and compared Lake Sturgeon selection for navigation channels vs. alternative pathways in two multi-channel rivers differentially affected by channelization, but free of barriers to sturgeon movement. Acoustic telemetry was used to quantify Lake Sturgeon movements. Under the assumption that Lake Sturgeon navigate by following primary flow paths, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River were expected to choose navigation channels over alternative pathways and to exhibit greater selection for navigation channels than conspecifics in the less-channelized lower St. Clair River. Consistent with these predictions, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River selected the higher-flow and deeper navigation channels over alternative migration pathways, whereas in the less-channelized lower St. Clair River, individuals primarily used pathways alternative to navigation channels. Lake Sturgeon selection for navigation channels as migratory pathways also was significantly higher in the more-channelized lower Detroit River than in the less-channelized lower St. Clair River. We speculated that use of navigation channels over alternative pathways would increase the spatial overlap of commercial vessels and migrating Lake Sturgeon, potentially enhancing their vulnerability to ship strikes. Results of our study thus demonstrated an association between channelization and the path use of migrating Lake Sturgeon that could prove

Voltage-Gated Calcium Channels

Science.gov (United States)

Zamponi, Gerald Werner

Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

An Outflow Event on the Left Side of Harvey: Erosion of Barrier Sand and Seaward Transport Through Aransas Pass

Science.gov (United States)

Goff, J.; Swartz, J. M.; Gulick, S. P. S.

2017-12-01

Barrier islands provide critical support and protection for coastal communities and ecosystems, but are potentially vulnerable to net losses of sand during major storms. Evidence from satellite imagery, ground observations and tide stations indicates that Hurricane Harvey in 2017 caused a large outflow event of waters moving from the bays out towards the sea in the Port Aransas, Texas region. Rather than just an ebb of a storm surge, this event may have been driven by seaward-directed winds on the left side of storm. Less than a month after landfall, we conducted a swath mapping and sampling survey in Lydia Ann Channel and Aransas Pass, where we had earlier mapped in 2009 and 2012 as part of the UT marine geology and geophysical field course. These waterways are important conduits linking Corpus Christi and Aransas bays to the Gulf of Mexico. This multi-year record allows us to gauge the impact of the outflow event on these waterways in the context of "normal" coastal processes. Both satellite imagery and sonar mapping reveal that the outflow event caused significant erosion, both on land and beneath the water, along the edges of Lydia Ann Channel and Corpus Christi ship channel. It also caused seaward-directed flow and erosion through breaches in the foredunes along southern San Jose Island, from waters that overtopped Lydia Ann Channel. Much of the sand that was transported seaward settled in Lydia Ann Channel and Aransas Pass (up to 6.5 m accumulation), possibly during the waning stages of the event. However, a likely large (but unknown) quantity of barrier and estuarine sand could have been transported well out to sea, beyond the jetties, at the peak of the event. If so, it would have resulted in a net loss of sand from the barrier island system.

Investigating the Lateral Mixing Coefficient in a Compound Channel with Emergent Vegetation over the Floodplain

OpenAIRE

Hossein hamidifar; Mohammad hossein Ommid; Mehdi Bahrami; Mohammad javad Amiri

2017-01-01

Introduction: Water quality control is very important for people, animals and plants. Predicting the spread of contaminants is important for managing and protecting rivers and streams to the balance of the ecosystem. Pollutants are introduced into waterways, though a variety of sources such as point and non-point sources. Under steady state conditions, where longitudinal mixing is not significant, studying the lateral mixing is essential in evaluating the influence of pollutants on water qual...

Evaluation channel performance in multichannel environments

NARCIS (Netherlands)

Gensler, S.; Dekimpe, M.; Skiera, B.

2007-01-01

Evaluating channel performance is crucial for actively managing multiple sales channels, and requires understanding the customers' channel preferences. Two key components of channel performance are (i) the existing customers' intrinsic loyalty to a particular channel and (ii) the channel's ability

Bacterial diversity impacts as a result of combined sewer overflow in a polluted waterway

Directory of Open Access Journals (Sweden)

O. Calderon

2017-12-01

Full Text Available Newtown Creek is an industrial waterway and former tidal wetland in New York City. It is one of the most polluted water bodies in the United States and was designated as a superfund site in 2010. For over a century, organic compounds, heavy metals, and other forms of industrial pollution have disrupted the creek’s environment. The creek is also impacted by discharges from twenty combined sewer overflow pipes, which may deposit raw sewage or partially treated wastewater directly into the creek during heavy or sustained rain events. Combined sewer overflow events and associated nutrient over-enrichment at the creek drive eutrophication and subsequent hypoxia. At the current study, three sites were sampled one week apart during a dry period and a wet period, where indication of a combined sewage overflow event could be detected. 16s rRNA high-throughput sequencing from these three sites collectively yielded over 1000 species of bacteria belonging to twenty-two classes. Based on these data, it is hypothesized that differences identified in the microbiome on wet versus dry days are as a result of combined sewage overflow, street runoff, and additional fluctuations in the creek’s environment associated with rain. It was found that after a combined sewer overflows event, the levels of Gamma Proteobacteria increased while the levels of Actinobacteria decreased. However, levels of bacteria stayed relatively unchanged at a site further away from combined sewer overflows discharge. Species found in Newtown Creek include pelagic, marine, human and animal pathogens, hydrocarbonoclastic, and other environmental microbes.

Channel Choice: A Literature Review

DEFF Research Database (Denmark)

Østergaard Madsen, Christian; Kræmmergaard, Pernille

2015-01-01

The channel choice branch of e-government studies citizens’ and businesses’ choice of channels for interacting with government, and how government organizations can integrate channels and migrate users towards the most cost-efficient channels. In spite of the valuable contributions offered...

Reconfigurable virtual electrowetting channels.

Science.gov (United States)

Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian

2012-02-21

Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.

KV7 potassium channels

DEFF Research Database (Denmark)

Stott, Jennifer B; Jepps, Thomas Andrew; Greenwood, Iain A

2014-01-01

Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been...

Preservation of meandering river channels in uniformly aggrading channel belts

NARCIS (Netherlands)

Lageweg, W.I. van de; Schuurman, F.; Cohen, K.M.; Dijk, W.M. van; Shimizu, Y.; Kleinhans, M.G.

2016-01-01

Channel belt deposits from meandering river systems commonly display an internal architecture of stacked depositional features with scoured basal contacts due to channel and bedform migration across a range of scales. Recognition and correct interpretation of these bounding surfaces is essential to

Multi-channel service retailing: The effects of channel performance satisfaction on behavioral intentions.

NARCIS (Netherlands)

Birgelen, van M.; Jong, de A.; Ruyter, de J.C.

2006-01-01

Abstract The number of channels that retailers can use interchangeably to provide customer service has increased. We report on a study of clients of a large retail bank that investigates the channel performance satisfaction–behavioral intentions relationship when the traditional service channel

Channel Planform Dynamics Monitoring and Channel Stability Assessment in Two Sediment-Rich Rivers in Taiwan

Directory of Open Access Journals (Sweden)

Cheng-Wei Kuo

2017-01-01

Full Text Available Recurrent flood events induced by typhoons are powerful agents to modify channel morphology in Taiwan’s rivers. Frequent channel migrations reflect highly sensitive valley floors and increase the risk to infrastructure and residents along rivers. Therefore, monitoring channel planforms is essential for analyzing channel stability as well as improving river management. This study analyzed annual channel changes along two sediment-rich rivers, the Zhuoshui River and the Gaoping River, from 2008 to 2015 based on satellite images of FORMOSAT-2. Channel areas were digitized from mid-catchment to river mouth (~90 km. Channel stability for reaches was assessed through analyzing the changes of river indices including braid index, active channel width, and channel activity. In general, the valley width plays a key role in braided degree, active channel width, and channel activity. These indices increase as the valley width expands whereas the braid index decreases slightly close to the river mouth due to the change of river types. This downstream pattern in the Zhuoshui River was interrupted by hydraulic construction which resulted in limited changes downstream from the weir, due to the lack of water and sediment supply. A 200-year flood, Typhoon Morakot in 2009, induced significant changes in the two rivers. The highly active landscape in Taiwan results in very sensitive channels compared to other regions. An integrated Sensitivity Index was proposed for identifying unstable reaches, which could be a useful reference for river authorities when making priorities in river regulation strategy. This study shows that satellite image monitoring coupled with river indices analysis could be an effective tool to evaluate spatial and temporal changes in channel stability in highly dynamic river systems.

Distribution Channels Conflict and Management

OpenAIRE

Kiran, Dr Vasanth; Majumdar, Dr Mousumi; Kishore, Dr Krishna

2012-01-01

Relationships in distribution channels tend to be long-term oriented and members of the channel rely on each other to jointly realize their goals by serving buyers. Despite the channels focus on serving buyers, conflicts often arise between channel members because of each members self-interest. When conflicts arise, the perceptions of a channel member based on normative, rational/instrumental, or emotional reasoning will influence relational norms like trust and commitment that characterize t...

Quantum communication under channel uncertainty

International Nuclear Information System (INIS)

Noetzel, Janis Christian Gregor

2012-01-01

This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

Electrophysiological characterisation of KCNQ channel modulators

DEFF Research Database (Denmark)

Schrøder, R.L

Potassium (K+) ion channels are ubiquitously expressed in mammalian cells, and each channel serves a precise physiological role due to its specific biophysical characteristics and expression pattern. A few K+ channels are targets for certain drugs, and in this thesis it is suggested that the KCNQ K......+ channels may be targets for neuroprotective, anti-epileptic and anti-nociceptive compounds. The importance of these channels is underscored by the fact that four out of five KCNQ channel subtypes are involved in severe human diseases. However, the pharmacology of the KCNQ channels is yet poorly understood...... as these channels were identified only recently. Therefore, there is a need for understanding the biophysical behavior and pharmacology of these ion channels. KCNQ channels belong to the group of voltage-activated K+ channels. The subfamily consists of KCNQ1-5, which is primarily expressed in the CNS, heart, ear...

Eight channel fast scalar

Energy Technology Data Exchange (ETDEWEB)

Waddoup, W D; Stubbs, R J [Durham Univ. (UK)

1977-11-01

An eight channel 64-bit scaler has been constructed with a static CMOS memory. Scaling frequencies are independently variable, at each channel, as are the number of bits/channel. The scaler, when used in conjunction with a multichannel charge to time converter results in a very flexible, gated multichannel ADC.

Automatic pickup of arrival time of channel wave based on multi-channel constraints

Science.gov (United States)

Wang, Bao-Li

2018-03-01

Accurately detecting the arrival time of a channel wave in a coal seam is very important for in-seam seismic data processing. The arrival time greatly affects the accuracy of the channel wave inversion and the computed tomography (CT) result. However, because the signal-to-noise ratio of in-seam seismic data is reduced by the long wavelength and strong frequency dispersion, accurately timing the arrival of channel waves is extremely difficult. For this purpose, we propose a method that automatically picks up the arrival time of channel waves based on multi-channel constraints. We first estimate the Jaccard similarity coefficient of two ray paths, then apply it as a weight coefficient for stacking the multichannel dispersion spectra. The reasonableness and effectiveness of the proposed method is verified in an actual data application. Most importantly, the method increases the degree of automation and the pickup precision of the channel-wave arrival time.

Functional modifications of acid-sensing ion channels by ligand-gated chloride channels.

Directory of Open Access Journals (Sweden)

Xuanmao Chen

Full Text Available Together, acid-sensing ion channels (ASICs and epithelial sodium channels (ENaC constitute the majority of voltage-independent sodium channels in mammals. ENaC is regulated by a chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR. Here we show that ASICs were reversibly inhibited by activation of GABA(A receptors in murine hippocampal neurons. This inhibition of ASICs required opening of the chloride channels but occurred with both outward and inward GABA(A receptor-mediated currents. Moreover, activation of the GABA(A receptors modified the pharmacological features and kinetic properties of the ASIC currents, including the time course of activation, desensitization and deactivation. Modification of ASICs by open GABA(A receptors was also observed in both nucleated patches and outside-out patches excised from hippocampal neurons. Interestingly, ASICs and GABA(A receptors interacted to regulate synaptic plasticity in CA1 hippocampal slices. The activation of glycine receptors, which are similar to GABA(A receptors, also modified ASICs in spinal neurons. We conclude that GABA(A receptors and glycine receptors modify ASICs in neurons through mechanisms that require the opening of chloride channels.

Coupling of SK channels, L-type Ca2+ channels, and ryanodine receptors in cardiomyocytes.

Science.gov (United States)

Zhang, Xiao-Dong; Coulibaly, Zana A; Chen, Wei Chun; Ledford, Hannah A; Lee, Jeong Han; Sirish, Padmini; Dai, Gu; Jian, Zhong; Chuang, Frank; Brust-Mascher, Ingrid; Yamoah, Ebenezer N; Chen-Izu, Ye; Izu, Leighton T; Chiamvimonvat, Nipavan

2018-03-16

Small-conductance Ca 2+ -activated K + (SK) channels regulate the excitability of cardiomyocytes by integrating intracellular Ca 2+ and membrane potentials on a beat-to-beat basis. The inextricable interplay between activation of SK channels and Ca 2+ dynamics suggests the pathology of one begets another. Yet, the exact mechanistic underpinning for the activation of cardiac SK channels remains unaddressed. Here, we investigated the intracellular Ca 2+ microdomains necessary for SK channel activation. SK currents coupled with Ca 2+ influx via L-type Ca 2+ channels (LTCCs) continued to be elicited after application of caffeine, ryanodine or thapsigargin to deplete SR Ca 2+ store, suggesting that LTCCs provide the immediate Ca 2+ microdomain for the activation of SK channels in cardiomyocytes. Super-resolution imaging of SK2, Ca v 1.2 Ca 2+ channel, and ryanodine receptor 2 (RyR2) was performed to quantify the nearest neighbor distances (NND) and localized the three molecules within hundreds of nanometers. The distribution of NND between SK2 and RyR2 as well as SK2 and Ca v 1.2 was bimodal, suggesting a spatial relationship between the channels. The activation mechanism revealed by our study paved the way for the understanding of the roles of SK channels on the feedback mechanism to regulate the activities of LTCCs and RyR2 to influence local and global Ca 2+ signaling.

Activation of TRPV1 channels inhibits mechanosensitive Piezo channel activity by depleting membrane phosphoinositides

Science.gov (United States)

Borbiro, Istvan; Badheka, Doreen; Rohacs, Tibor

2015-01-01

Capsaicin is an activator of the heat-sensitive TRPV1 (transient receptor potential vanilloid 1) ion channels and has been used as a local analgesic. We found that activation of TRPV1 channels with capsaicin either in dorsal root ganglion neurons or in a heterologous expression system inhibited the mechanosensitive Piezo1 and Piezo2 channels by depleting phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and its precursor PI(4)P from the plasma membrane through Ca2+-induced phospholipase Cδ (PLCδ) activation. Experiments with chemically inducible phosphoinositide phosphatases and receptor-induced activation of PLCβ indicated that inhibition of Piezo channels required depletion of both PI(4)P and PI(4,5)P2. The mechanically activated current amplitudes decreased substantially in the excised inside-out configuration, where the membrane patch containing Piezo1 channels is removed from the cell. PI(4,5)P2 and PI(4)P applied to these excised patches inhibited this decrease. Thus, we concluded that Piezo channel activity requires the presence of phosphoinositides, and the combined depletion of PI(4,5)P2 or PI(4)P reduces channel activity. In addition to revealing a role for distinct membrane lipids in mechanosensitive ion channel regulation, these data suggest that inhibition of Piezo2 channels may contribute to the analgesic effect of capsaicin. PMID:25670203

New Channels, New Possibilities

DEFF Research Database (Denmark)

Pieterson, Willem; Ebbers, Wolfgang; Østergaard Madsen, Christian

2017-01-01

In this contribution we discuss the characteristics of what we call the fourth generation of public sector service channels: social robots. Based on a review of relevant literature we discuss their characteristics and place into multi-channel models of service delivery. We argue that social robots......-channel models of service delivery. This is especially relevant given the current lack of evaluations of such models, the broad range of channels available, and their different stages of deployment at governments around the world. Nevertheless, social robots offer an potentially very relevant addition...

Mapping the potential distribution of the invasive Red Shiner, Cyprinella lutrensis (Teleostei: Cyprinidae) across waterways of the conterminous United States

Science.gov (United States)

Poulos, Helen M.; Chernoff, Barry; Fuller, Pam L.; Butman, David

2012-01-01

Predicting the future spread of non-native aquatic species continues to be a high priority for natural resource managers striving to maintain biodiversity and ecosystem function. Modeling the potential distributions of alien aquatic species through spatially explicit mapping is an increasingly important tool for risk assessment and prediction. Habitat modeling also facilitates the identification of key environmental variables influencing species distributions. We modeled the potential distribution of an aggressive invasive minnow, the red shiner (Cyprinella lutrensis), in waterways of the conterminous United States using maximum entropy (Maxent). We used inventory records from the USGS Nonindigenous Aquatic Species Database, native records for C. lutrensis from museum collections, and a geographic information system of 20 raster climatic and environmental variables to produce a map of potential red shiner habitat. Summer climatic variables were the most important environmental predictors of C. lutrensis distribution, which was consistent with the high temperature tolerance of this species. Results from this study provide insights into the locations and environmental conditions in the US that are susceptible to red shiner invasion.

Ion channelling in diamond

International Nuclear Information System (INIS)

Derry, T.E.

1978-06-01

Diamond is one of the most extreme cases from a channelling point of view, having the smallest thermal vibration amplitude and the lowest atomic number of commonly-encountered crystals. These are the two parameters most important for determining channelling behaviour. It is of consiberable interest therefore to see how well the theories explaining and predicting the channeling properties of other substance, succeed with diamond. Natural diamond, although the best available form for these experiments, is rather variable in its physical properties. Part of the project was devoted to considering and solving the problem of obtaining reproducible results representative of the ideal crystal. Channelling studies were performed on several good crystals, using the Rutherford backscattering method. Critical angles for proton channelling were measured for incident energies from 0.6 to 4.5 MeV, in the three most open axes and three most open planes of the diamond structure, and for α-particle channelling at 0.7 and 1.0 MeV (He + ) in the same axes and planes. For 1.0 MeV protons, the crystal temperature was varied from 20 degrees Celsius to 700 degrees Celsius. The results are presented as curves of backscattered yield versus angle in the region of each axis or plane, and summarised in the form of tables and graphs. Generally the critical angles, axial minimum yields, and temperature dependence are well predicted by the accepted theories. The most valuable overall conclusion is that the mean thermal vibration amplitude of the atoms in a crytical determines the critical approach distance to the channel walls at which an ion can remain channelled, even when this distance is much smaller than the Thomas-Fermi screening distance of the atomic potential, as is the case in diamond. A brief study was made of the radiation damage caused by α-particle bombardment, via its effect on the channelling phenomenon. It was possible to hold damage down to negligible levels during the

Ion Channel Trafficking: Control of Ion Channel Density as a Target for Arrhythmias?

Directory of Open Access Journals (Sweden)

Elise Balse

2017-10-01

Full Text Available The shape of the cardiac action potential (AP is determined by the contributions of numerous ion channels. Any dysfunction in the proper function or expression of these ion channels can result in a change in effective refractory period (ERP and lead to arrhythmia. The processes underlying the correct targeting of ion channels to the plasma membrane are complex, and have not been fully characterized in cardiac myocytes. Emerging evidence highlights ion channel trafficking as a potential causative factor in certain acquired and inherited arrhythmias, and therapies which target trafficking as opposed to pore block are starting to receive attention. In this review we present the current evidence for the mechanisms which underlie precise control of cardiac ion channel trafficking and targeting.

Customer Responses to Channel Migration Strategies Toward the E-channel

NARCIS (Netherlands)

Trampe, Debra; Konus, Umut; Verhoef, Peter C.

2014-01-01

Many firms stimulate customers to use the E-channel for services, which provokes various consumer responses to such limits on their freedom of choice. In a study on bank customers, we examine the extent of customer reactance in response to various E-channel migration strategies, the potential of

Multi-rate control over AWGN channels via analog joint source-channel coding

KAUST Repository

Khina, Anatoly; Pettersson, Gustav M.; Kostina, Victoria; Hassibi, Babak

2017-01-01

We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

Multi-rate control over AWGN channels via analog joint source-channel coding

KAUST Repository

Khina, Anatoly

2017-01-05

We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel\\'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

Channel sialic acids limit hERG channel activity during the ventricular action potential.

Science.gov (United States)

Norring, Sarah A; Ednie, Andrew R; Schwetz, Tara A; Du, Dongping; Yang, Hui; Bennett, Eric S

2013-02-01

Activity of human ether-a-go-go-related gene (hERG) 1 voltage-gated K(+) channels is responsible for portions of phase 2 and phase 3 repolarization of the human ventricular action potential. Here, we questioned whether and how physiologically and pathophysiologically relevant changes in surface N-glycosylation modified hERG channel function. Voltage-dependent hERG channel gating and activity were evaluated as expressed in a set of Chinese hamster ovary (CHO) cell lines under conditions of full glycosylation, no sialylation, no complex N-glycans, and following enzymatic deglycosylation of surface N-glycans. For each condition of reduced glycosylation, hERG channel steady-state activation and inactivation relationships were shifted linearly by significant depolarizing ∼9 and ∼18 mV, respectively. The hERG window current increased significantly by 50-150%, and the peak shifted by a depolarizing ∼10 mV. There was no significant change in maximum hERG current density. Deglycosylated channels were significantly more active (20-80%) than glycosylated controls during phases 2 and 3 of action potential clamp protocols. Simulations of hERG current and ventricular action potentials corroborated experimental data and predicted reduced sialylation leads to a 50-70-ms decrease in action potential duration. The data describe a novel mechanism by which hERG channel gating is modulated through physiologically and pathophysiologically relevant changes in N-glycosylation; reduced channel sialylation increases hERG channel activity during the action potential, thereby increasing the rate of action potential repolarization.

Course on Ionic Channels

CERN Document Server

1986-01-01

This book is based on a series of lectures for a course on ionic channels held in Santiago, Chile, on November 17-20, 1984. It is intended as a tutorial guide on the properties, function, modulation, and reconstitution of ionic channels, and it should be accessible to graduate students taking their first steps in this field. In the presentation there has been a deliberate emphasis on the spe­ cific methodologies used toward the understanding of the workings and function of channels. Thus, in the first section, we learn to "read" single­ channel records: how to interpret them in the theoretical frame of kinetic models, which information can be extracted from gating currents in re­ lation to the closing and opening processes, and how ion transport through an open channel can be explained in terms of fluctuating energy barriers. The importance of assessing unequivocally the origin and purity of mem­ brane preparations and the use of membrane vesicles and optical tech­ niques in the stUGY of ionic channels a...

Quantum communication under channel uncertainty

Energy Technology Data Exchange (ETDEWEB)

Noetzel, Janis Christian Gregor

2012-09-06

This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

XPM-induced degradation of multilevel phase modulated channel caused by neighboring NRZ modulated channels

DEFF Research Database (Denmark)

Jensen, Jesper Bevensee; Schiellerup, G.; Peucheret, Christophe

2008-01-01

The impact of XPM from NRZ modulated channels on an 8-level phase modulated channel in a WDM system was investigated. Requirements on launch power are found. 400 km transmission was achieved with negligible penalty.......The impact of XPM from NRZ modulated channels on an 8-level phase modulated channel in a WDM system was investigated. Requirements on launch power are found. 400 km transmission was achieved with negligible penalty....

On the secrecy capacity of the wiretap channel with imperfect main channel estimation

KAUST Repository

Rezki, Zouheir

2014-10-01

We study the secrecy capacity of fast fading channels under imperfect main channel (between the transmitter and the legitimate receiver) estimation at the transmitter. Lower and upper bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate follows from a standard wiretap code in which a simple on-off power control is employed along with a Gaussian input. The upper bound is obtained using an appropriate correlation scheme of the main and eavesdropper channels and is the best known upper bound so far. The upper and lower bounds coincide with recently derived ones in case of perfect main CSI. Furthermore, the upper bound is tight in case of no main CSI, where the secrecy capacity is equal to zero. Asymptotic analysis at high and low signal-to-noise ratio (SNR) is also given. At high SNR, we show that the capacity is bounded by providing upper and lower bounds that depend on the channel estimation error. At low SNR, however, we prove that the secrecy capacity is asymptotically equal to the capacity of the main channel as if there were no secrecy constraint. Numerical results are provided for i.i.d. Rayleigh fading channels.

Cardiac potassium channel subtypes

DEFF Research Database (Denmark)

Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter

2014-01-01

About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... drive the late repolarization of the ventricle with some redundancy, and in atria this repolarization reserve is supplemented by the fairly atrial-specific KV1.5, Kir3, KCa, and K2P channels. The role of the latter two subtypes in atria is currently being clarified, and several findings indicate...... that they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure...

Channel Estimation in DCT-Based OFDM

Science.gov (United States)

Wang, Yulin; Zhang, Gengxin; Xie, Zhidong; Hu, Jing

2014-01-01

This paper derives the channel estimation of a discrete cosine transform- (DCT-) based orthogonal frequency-division multiplexing (OFDM) system over a frequency-selective multipath fading channel. Channel estimation has been proved to improve system throughput and performance by allowing for coherent demodulation. Pilot-aided methods are traditionally used to learn the channel response. Least square (LS) and mean square error estimators (MMSE) are investigated. We also study a compressed sensing (CS) based channel estimation, which takes the sparse property of wireless channel into account. Simulation results have shown that the CS based channel estimation is expected to have better performance than LS. However MMSE can achieve optimal performance because of prior knowledge of the channel statistic. PMID:24757439

A new simple model for composite fading channels: Second order statistics and channel capacity

KAUST Repository

Yilmaz, Ferkan; Alouini, Mohamed-Slim

2010-01-01

In this paper, we introduce the most general composite fading distribution to model the envelope and the power of the received signal in such fading channels as millimeter wave (60 GHz or above) fading channels and free-space optical channels, which

CANDU channel flow verification

International Nuclear Information System (INIS)

Mazalu, N.; Negut, Gh.

1997-01-01

The purpose of this evaluation was to obtain accurate information on each channel flow that enables us to assess precisely the level of reactor thermal power and, for reasons of safety, to establish which channel is boiling. In order to assess the channel flow parameters, computer simulations were done with the NUCIRC code and the results were checked by measurements. The complete channel flow measurements were made in the zero power cold condition. In hot conditions there were made flow measurements using the Shut Down System 1 (SDS 1) flow devices from 0.1 % F.P. up to 100 % F.P. The NUCIRC prediction for CANDU channel flows and the measurements by Ultrasonic Flow Meter at zero power cold conditions and SDS 1 flow channel measurements at different reactor power levels showed an acceptable agreement. The 100 % F.P. average errors for channel flow of R, shows that suitable NUCIRC flow assessment can be made. So, it can be done a fair prediction of the reactor power distribution. NUCIRC can predict accurately the onset of boiling and helps to warn at the possible power instabilities at high powers or it can detect the flow blockages. The thermal hydraulic analyst has in NUCIRC a suitable tool to do accurate predictions for the thermal hydraulic parameters for different steady state power levels which subsequently leads to an optimal CANDU reactor operation. (authors)

Channel Simulation in Quantum Metrology

Directory of Open Access Journals (Sweden)

Laurenza Riccardo

2018-04-01

Full Text Available In this review we discuss how channel simulation can be used to simplify the most general protocols of quantum parameter estimation, where unlimited entanglement and adaptive joint operations may be employed. Whenever the unknown parameter encoded in a quantum channel is completely transferred in an environmental program state simulating the channel, the optimal adaptive estimation cannot beat the standard quantum limit. In this setting, we elucidate the crucial role of quantum teleportation as a primitive operation which allows one to completely reduce adaptive protocols over suitable teleportation-covariant channels and derive matching upper and lower bounds for parameter estimation. For these channels,wemay express the quantum Cramér Rao bound directly in terms of their Choi matrices. Our review considers both discrete- and continuous-variable systems, also presenting some new results for bosonic Gaussian channels using an alternative sub-optimal simulation. It is an open problem to design simulations for quantum channels that achieve the Heisenberg limit.

Effect of channel-protein interaction on translocation of a protein-like chain through a finite channel

International Nuclear Information System (INIS)

Sun Ting-Ting; Ma Hai-Zhu; Jiang Zhou-Ting

2012-01-01

We study the translocation of a protein-like chain through a finite cylindrical channel using the pruned-enriched Rosenbluth method (PERM) and the modified orientation-dependent monomer-monomer interaction (ODI) model. Attractive channels (in cp = −2.0, −1.0, −0.5), repulsive channels (in cp = 0.5, 1.0, 2.0), and a neutral channel (in cp = 0) are discussed. The results of the chain dimension and the energy show that Z 0 = 1.0 is an important case to distinguish the types of the channels. For the strong attractive channel, more contacts form during the process of translocation. It is also found that an external force is needed to drive the chain outside of the channel with the strong attraction. While for the neutral, the repulsive, and the weak attractive channels, the translocation is spontaneous. (interdisciplinary physics and related areas of science and technology)

Radar channel balancing with commutation

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin Walter

2014-02-01

When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

Cl- channels in apoptosis

DEFF Research Database (Denmark)

Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida

2016-01-01

A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin......, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also......(-) channels or as regulators of other apoptotic Cl(-) channels, such as LRRC8. CFTR has been known for its proapoptotic effects for some time, and this effect may be based on glutathione release from the cell and increase in cytosolic reactive oxygen species (ROS). Although we find that CFTR is activated...

Direct channel problems and phenomena

International Nuclear Information System (INIS)

Cutkosky, R.E.

1975-01-01

Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

Nuclear reactor coolant channels

International Nuclear Information System (INIS)

Macbeth, R.V.

1978-01-01

Reference is made to coolant channels for pressurised water and boiling water reactors and the arrangement described aims to improve heat transfer between the fuel rods and the coolant. Baffle means extending axially within the channel are provided and disposed relative to the fuel rods so as to restrict flow oscillations occurring within the coolant from being propagated transversely to the axis of the channel. (UK)

An FPGA-Based Adaptable 200 MHz Bandwidth Channel Sounder for Wireless Communication Channel Characterisation

Directory of Open Access Journals (Sweden)

David L. Ndzi

2011-01-01

Full Text Available This paper describes the development of a fast adaptable FPGA-based wideband channel sounder with signal bandwidths of up to 200 MHz and channel sampling rates up to 5.4 kHz. The application of FPGA allows the user to vary the number of real-time channel response averages, channel sampling interval, and duration of measurement. The waveform, bandwidth, and frequency resolution of the sounder can be adapted for any channel under investigation. The design approach and technology used has led to a reduction in size and weight by more than 60%. This makes the sounder ideal for mobile time-variant wireless communication channels studies. Averaging allows processing gains of up to 30 dB to be achieved for measurement in weak signal conditions. The technique applied also improves reliability, reduces power consumption, and has shifted sounder design complexity from hardware to software. Test results show that the sounder can detect very small-scale variations in channels.

The KATP channel in migraine pathophysiology

DEFF Research Database (Denmark)

Al-Karagholi, Mohammad Al-Mahdi; Hansen, Jakob Møller; Severinsen, Johanne

2017-01-01

BACKGROUND: To review the distribution and function of KATP channels, describe the use of KATP channels openers in clinical trials and make the case that these channels may play a role in headache and migraine. DISCUSSION: KATP channels are widely present in the trigeminovascular system and play...... an important role in the regulation of tone in cerebral and meningeal arteries. Clinical trials using synthetic KATP channel openers report headache as a prevalent-side effect in non-migraine sufferers, indicating that KATP channel opening may cause headache, possibly due to vascular mechanisms. Whether KATP...... channel openers can provoke migraine in migraine sufferers is not known. CONCLUSION: We suggest that KATP channels may play an important role in migraine pathogenesis and could be a potential novel therapeutic anti-migraine target....

Six-channel adaptive fibre-optic interferometer

Energy Technology Data Exchange (ETDEWEB)

Romashko, R V; Bezruk, M N; Kamshilin, A A; Kulchin, Yurii N

2012-06-30

We have proposed and analysed a scheme for the multiplexing of orthogonal dynamic holograms in photorefractive crystals which ensures almost zero cross talk between the holographic channels upon phase demodulation. A six-channel adaptive fibre-optic interferometer was built, and the detection limit for small phase fluctuations in the channels of the interferometer was determined to be 2.1 Multiplication-Sign 10{sup -8} rad W{sup 1/2} Hz{sup -1/2}. The channel multiplexing capacity of the interferometer was estimated. The formation of 70 channels such that their optical fields completely overlap in the crystal reduces the relative detection limit in the working channel by just 10 %. We found conditions under which the maximum cross talk between the channels was within the intrinsic noise level in the channels (-47 dB).

G-Channel Restoration for RWB CFA with Double-Exposed W Channel.

Science.gov (United States)

Park, Chulhee; Song, Ki Sun; Kang, Moon Gi

2017-02-05

In this paper, we propose a green (G)-channel restoration for a red-white-blue (RWB) color filter array (CFA) image sensor using the dual sampling technique. By using white (W) pixels instead of G pixels, the RWB CFA provides high-sensitivity imaging and an improved signal-to-noise ratio compared to the Bayer CFA. However, owing to this high sensitivity, the W pixel values become rapidly over-saturated before the red-blue (RB) pixel values reach the appropriate levels. Because the missing G color information included in the W channel cannot be restored with a saturated W, multiple captures with dual sampling are necessary to solve this early W-pixel saturation problem. Each W pixel has a different exposure time when compared to those of the R and B pixels, because the W pixels are double-exposed. Therefore, a RWB-to-RGB color conversion method is required in order to restore the G color information, using a double-exposed W channel. The proposed G-channel restoration algorithm restores G color information from the W channel by considering the energy difference caused by the different exposure times. Using the proposed method, the RGB full-color image can be obtained while maintaining the high-sensitivity characteristic of the W pixels.

X-ray radiation channeling in micro-channel plates: Spectroscopy with a synchrotron radiation beam

International Nuclear Information System (INIS)

Mazuritskiy, M.I.; Dabagov, S.B.; Marcelli, A.; Dziedzic-Kocurek, K.; Lerer, A.M.

2015-01-01

We present here the angular distribution of the radiation propagated inside MultiChannel Plates with micro-channels of ∼3 μm diameter. The spectra collected at the exit of the channels present a complex distribution with contributions that can be assigned to the fluorescence radiation, originated from the excitation of the micro-channel walls. For radiation above the absorption edge, when the monochromatic energy in the region of the Si L-edge hits the micro-channel walls with a grazing angle θ ⩾ 5°, or at the O K-edge when θ ⩾ 2° a fluorescence radiation is detected. Additional information associated to the fine structures of the XANES spectra detected at the exit of MCPs are also presented and discussed

HIPPI and Fibre Channel

International Nuclear Information System (INIS)

Tolmie, D.E.

1992-01-01

The High-Performance Parallel Interface (HIPPI) and Fibre Channel are near-gigabit per second data communications interfaces being developed in ANSI standards Task Group X3T9.3. HIPPI is the current interface of choice in the high-end and supercomputer arena, and Fibre Channel is a follow-on effort. HIPPI came from a local area network background, and Fibre Channel came from a mainframe to peripheral interface background

Quantum channels with a finite memory

International Nuclear Information System (INIS)

Bowen, Garry; Mancini, Stefano

2004-01-01

In this paper we study quantum communication channels with correlated noise effects, i.e., quantum channels with memory. We derive a model for correlated noise channels that includes a channel memory state. We examine the case where the memory is finite, and derive bounds on the classical and quantum capacities. For the entanglement-assisted and unassisted classical capacities it is shown that these bounds are attainable for certain classes of channel. Also, we show that the structure of any finite-memory state is unimportant in the asymptotic limit, and specifically, for a perfect finite-memory channel where no information is lost to the environment, achieving the upper bound implies that the channel is asymptotically noiseless

Improvement of Metroliner Telephone Channel Capacity and Modeling of Telephone Channel Demands

Science.gov (United States)

1972-03-01

The channel capacity of the present Metroliner telephone system is analyzed and methods are proposed to increase that capacity without increasing the overall bandwidth. To determine the number of channels required, calculations have been carried out ...

Channel erosion in a rapidly urbanizing region of Tijuana, Mexico: Enlargement downstream of channel hardpoints

Science.gov (United States)

Taniguchi, Kristine; Biggs, Trent; Langendoen, Eddy; Castillo, Carlos; Gudiño, Napoleon; Yuan, Yongping; Liden, Douglas

2016-04-01

Urban-induced erosion in Tijuana, Mexico, has led to excessive sediment deposition in the Tijuana Estuary in the United States. Urban areas in developing countries, in contrast to developed countries, are characterized by much lower proportions of vegetation and impervious surfaces due to limited access to urban services such as road paving and landscaping, and larger proportions of exposed soils. In developing countries, traditional watershed scale variables such as impervious surfaces may not be good predictors of channel enlargement. In this research, we surveyed the stream channel network of an erodible tributary of the Tijuana River Watershed, Los Laureles Canyon, at 125 locations, including repeat surveys from 2008. Structure from Motion (SfM) and 3D photo-reconstruction techniques were used to create digital terrain models of stream reaches upstream and downstream of channel hardpoints. Channels are unstable downstream of hardpoints, with incision up to 2 meters and widening up to 12 meters. Coordinated channelization is essential to avoid piece-meal approaches that lead to channel degradation. Watershed impervious area is not a good predictor of channel erosion due to the overriding importance of hardpoints and likely to the high sediment supply from the unpaved roads which prevents channel erosion throughout the stream network.

Parallel inter channel interaction mechanisms

International Nuclear Information System (INIS)

Jovic, V.; Afgan, N.; Jovic, L.

1995-01-01

Parallel channels interactions are examined. For experimental researches of nonstationary regimes flow in three parallel vertical channels results of phenomenon analysis and mechanisms of parallel channel interaction for adiabatic condition of one-phase fluid and two-phase mixture flow are shown. (author)

Matching Dyadic Distributions to Channels

OpenAIRE

Böcherer, Georg; Mathar, Rudolf

2010-01-01

Many communication channels with discrete input have non-uniform capacity achieving probability mass functions (PMF). By parsing a stream of independent and equiprobable bits according to a full prefix-free code, a modu-lator can generate dyadic PMFs at the channel input. In this work, we show that for discrete memoryless channels and for memoryless discrete noiseless channels, searching for good dyadic input PMFs is equivalent to minimizing the Kullback-Leibler distance between a dyadic PMF ...

Multiplicative properties of quantum channels

Science.gov (United States)

Rahaman, Mizanur

2017-08-01

In this paper, we study the multiplicative behaviour of quantum channels, mathematically described by trace preserving, completely positive maps on matrix algebras. It turns out that the multiplicative domain of a unital quantum channel has a close connection to its spectral properties. A structure theorem (theorem 2.5), which reveals the automorphic property of an arbitrary unital quantum channel on a subalgebra, is presented. Various classes of quantum channels (irreducible, primitive, etc) are then analysed in terms of this stabilising subalgebra. The notion of the multiplicative index of a unital quantum channel is introduced, which measures the number of times a unital channel needs to be composed with itself for the multiplicative algebra to stabilise. We show that the maps that have trivial multiplicative domains are dense in completely bounded norm topology in the set of all unital completely positive maps. Some applications in quantum information theory are discussed.

Long Channel Carbon Nanotube as an Alternative to Nanoscale Silicon Channels in Scaled MOSFETs

Directory of Open Access Journals (Sweden)

Michael Loong Peng Tan

2013-01-01

Full Text Available Long channel carbon nanotube transistor (CNT can be used to overcome the high electric field effects in nanoscale length silicon channel. When maximum electric field is reduced, the gate of a field-effect transistor (FET is able to gain control of the channel at varying drain bias. The device performance of a zigzag CNTFET with the same unit area as a nanoscale silicon metal-oxide semiconductor field-effect transistor (MOSFET channel is assessed qualitatively. The drain characteristic of CNTFET and MOSFET device models as well as fabricated CNTFET device are explored over a wide range of drain and gate biases. The results obtained show that long channel nanotubes can significantly reduce the drain-induced barrier lowering (DIBL effects in silicon MOSFET while sustaining the same unit area at higher current density.

Local quantum channels preserving classical correlations

International Nuclear Information System (INIS)

Guo Zhihua; Cao Huaixin

2013-01-01

The aim of this paper is to discuss local quantum channels that preserve classical correlations. First, we give two equivalent characterizations of classical correlated states. Then we obtain the relationships among classical correlation-preserving local quantum channels, commutativity-preserving local quantum channels and commutativity-preserving quantum channels on each subsystem. Furthermore, for a two-qubit system, we show the general form of classical correlation-preserving local quantum channels. (paper)

USACE Navigation Channels 2012

Data.gov (United States)

California Natural Resource Agency — This dataset represents both San Francisco and Los Angeles District navigation channel lines. All San Francisco District channel lines were digitized from CAD files...

Isotachophoresis system having larger-diameter channels flowing into channels with reduced diameter and with selectable counter-flow

Energy Technology Data Exchange (ETDEWEB)

Mariella, Jr., Raymond P.

2018-03-06

An isotachophoresis system for separating a sample containing particles into discrete packets including a flow channel, the flow channel having a large diameter section and a small diameter section; a negative electrode operably connected to the flow channel; a positive electrode operably connected to the flow channel; a leading carrier fluid in the flow channel; a trailing carrier fluid in the flow channel; and a control for separating the particles in the sample into discrete packets using the leading carrier fluid, the trailing carrier fluid, the large diameter section, and the small diameter section.

Sedimentary processes of the lower Monterey Fan channel and channel-mouth lobe

Science.gov (United States)

Klaucke, I.; Masson, D.G.; Kenyon, Neil H.; Gardner, J.V.

2004-01-01

The distribution of deposits, sediment transport pathways and processes on the lower Monterey Fan channel and channel-mouth lobe (CML) are studied through the integration of GLORIA and TOBI sidescan sonar data with 7-kHz subbottom profiler records and sediment cores for ground-truthing. The lower Monterey channel is characterised by an up to 30-m-deep channel with poorly developed levees and alternating muddy and silty muddy overbank deposits. The channel is discontinuous, disappearing where gradients are less than about 1:350. Ground-truthing of the large CML shows that the entire CML is characterised by widespread deposits of generally fine sand, with coarser sand at the base of turbidites. Sand is particularly concentrated in finger-like areas of low-backscatter intensity and is interpreted as the result of non-turbulent sediment-gravity flows depositing metres thick massive, fine sand. TOBI sidescan sonar data reveal recent erosional features in the form of scours, secondary channels, large flow slides, and trains of blocks at the distal end of the CML. Erosion is probably related to increasing gradient as the CML approaches Murray Fracture zone and to differential loading of sandy submarine fan deposits onto pelagic clays. Reworking of older flow slides by sediment transport processes on the lobe produces trains of blocks that are several metres in diameter and aligned parallel to the flow direction. ?? 2004 Elsevier B.V. All rights reserved.

Achievable Rates of Secure Transmission in Gaussian MISO Channel with Imperfect Main Channel Estimation

KAUST Repository

Zhou, Xinyu; Rezki, Zouheir; Alomair, Basel; Alouini, Mohamed-Slim

2016-01-01

A Gaussian multiple-input single-output (MISO) fading channel is considered. We assume that the transmitter, in addition to the statistics of all channel gains, is aware instantaneously of a noisy version of the channel to the legitimate receiver. On the other hand, the legitimate receiver is aware instantaneously of its channel to the transmitter, whereas the eavesdropper instantaneously knows all channel gains. We evaluate an achievable rate using a Gaussian input without indexing an auxiliary random variable. A sufficient condition for beamforming to be optimal is provided. When the number of transmit antennas is large, beamforming also turns out to be optimal. In this case, the maximum achievable rate can be expressed in a simple closed form and scales with the logarithm of the number of transmit antennas. Furthermore, in the case when a noisy estimate of the eavesdropper’s channel is also available at the transmitter, we introduce the SNR difference and the SNR ratio criterions and derive the related optimal transmission strategies and the corresponding achievable rates.

Achievable Rates of Secure Transmission in Gaussian MISO Channel with Imperfect Main Channel Estimation

KAUST Repository

Zhou, Xinyu

2016-03-15

A Gaussian multiple-input single-output (MISO) fading channel is considered. We assume that the transmitter, in addition to the statistics of all channel gains, is aware instantaneously of a noisy version of the channel to the legitimate receiver. On the other hand, the legitimate receiver is aware instantaneously of its channel to the transmitter, whereas the eavesdropper instantaneously knows all channel gains. We evaluate an achievable rate using a Gaussian input without indexing an auxiliary random variable. A sufficient condition for beamforming to be optimal is provided. When the number of transmit antennas is large, beamforming also turns out to be optimal. In this case, the maximum achievable rate can be expressed in a simple closed form and scales with the logarithm of the number of transmit antennas. Furthermore, in the case when a noisy estimate of the eavesdropper’s channel is also available at the transmitter, we introduce the SNR difference and the SNR ratio criterions and derive the related optimal transmission strategies and the corresponding achievable rates.

Clofilium inhibits Slick and Slack potassium channels.

Science.gov (United States)

de Los Angeles Tejada, Maria; Stolpe, Kathleen; Meinild, Anne-Kristine; Klaerke, Dan A

2012-01-01

Slick and Slack high-conductance potassium channels have been recently discovered, and are found in the central nervous system and in the heart. Both channels are activated by Na(+) and Cl(-), and Slick channels are also inhibited by adenosine triphospate (ATP). An important role of setting the resting membrane potential and controlling the basal excitability of neurons has been suggested for these channels. In addition, no specific blockers for these channels are known up to the present. With the purpose of studying the pharmacological characteristics of Slick and Slack channels, the effects of exposure to the antiarrhythmic compound clofilium were evaluated. Clofilium was able to modulate the activity of Slick and Slack channels effectively, with a stronger effect on Slack than Slick channels. In order to evaluate the pharmacological behavior of Slick and Slack channels further, 38 commonly used potassium channel blockers were tested. Screening of these compounds did not reveal any modulators of Slick and Slack channels, except for clofilium. The present study provides a first approach towards elucidating the pharmacological characteristics of Slick and Slack channels and could be the basis for future studies aimed at developing potent and specific blockers and activators for these channels.

Sensing with Ion Channels

CERN Document Server

Martinac, Boris

2008-01-01

All living cells are able to detect and translate environmental stimuli into biologically meaningful signals. Sensations of touch, hearing, sight, taste, smell or pain are essential to the survival of all living organisms. The importance of sensory input for the existence of life thus justifies the effort made to understand its molecular origins. Sensing with Ion Channels focuses on ion channels as key molecules enabling biological systems to sense and process the physical and chemical stimuli that act upon cells in their living environment. Its aim is to serve as a reference to ion channel specialists and as a source of new information to non specialists who want to learn about the structural and functional diversity of ion channels and their role in sensory physiology.

Microstructural information from channeling measurements

International Nuclear Information System (INIS)

Quere, Y.

1984-09-01

Channeling is sensitive to nearly all structural changes in solids. One briefly recalls how particles are dechanneled by lattice defects and describes the main applications of channeling to materials science: detection of radiation damage, location of impurity atoms, precipitations in alloys... Channeling being a phenomenon characteristic of perfect crystals, any type of lattice imperfection (phonons, crystal defects, precipitation etc.) is expected to produce dechanneling. Consequently channeling and its opposite, dechanneling, have both been used to study structure and structural changes of materials

Pharmacological modulation of SK3 channels

DEFF Research Database (Denmark)

Grunnet, M; Jespersen, Thomas; Angelo, K

2001-01-01

Small-conductance, calcium-activated K+ channels (SK channels) are voltage-insensitive channels that have been identified molecularly within the last few years. As SK channels play a fundamental role in most excitable cells and participate in afterhyperpolarization (AHP) and spike-frequency adapt...... at concentrations of 3 microM and above. Amitriptyline, a tricyclic antidepressive widely used clinically, inhibits SK3 channels with an IC50 of 39.1 +/- 10 microM (n=6)....

Optimising the Quality of Experience during Channel Zapping : The Impact of Advertisements during Channel Zapping

NARCIS (Netherlands)

Kooij, R.E.; Klos, V.B.; Godana, B.E.; Nicolai, F.P.; Ahmed, O.K.

2009-01-01

Nowadays various digital television services are available. However, the user of these services experiences longer delays than the traditional analog TV while switching from channel to channel. The digital TV operator usually displays a black screen with the channel number during zapping. However,

On the Capacity of the Dirty Paper Channel with Fast Fading and Discrete Channel States

OpenAIRE

Rini, Stefano; Shitz, Shlomo Shamai

2016-01-01

The "writing dirty paper" capacity result crucially dependents on the perfect channel knowledge at the transmitter as the presence of even a small uncertainty in the channel realization gravely hampers the ability of the transmitter to pre-code its transmission against the channel state. This is particularly disappointing as it implies that interference pre-coding in practical systems is effective only when the channel estimates at the users have very high precision, a condition which is gene...

Downlink Channel Estimation in Cellular Systems with Antenna Arrays at Base Stations Using Channel Probing with Feedback

Directory of Open Access Journals (Sweden)

Biguesh Mehrzad

2004-01-01

Full Text Available In mobile communication systems with multisensor antennas at base stations, downlink channel estimation plays a key role because accurate channel estimates are needed for transmit beamforming. One efficient approach to this problem is channel probing with feedback. In this method, the base station array transmits probing (training signals. The channel is then estimated from feedback reports provided by the users. This paper studies the performance of the channel probing method with feedback using a multisensor base station antenna array and single-sensor users. The least squares (LS, linear minimum mean square error (LMMSE, and a new scaled LS (SLS approaches to the channel estimation are studied. Optimal choice of probing signals is investigated for each of these techniques and their channel estimation performances are analyzed. In the case of multiple LS channel estimates, the best linear unbiased estimation (BLUE scheme for their linear combining is developed and studied.

TRP channels in kidney disease.

NARCIS (Netherlands)

Hsu, Y.J.; Hoenderop, J.G.J.; Bindels, R.J.M.

2007-01-01

Mammalian TRP channel proteins form six-transmembrane cation-permeable channels that may be grouped into six subfamilies on the basis of amino acid sequence homology (TRPC, TRPV, TRPM, TRPA, TRPP, and TRPML). Recent studies of TRP channels indicate that they are involved in numerous fundamental cell

Plasma channels for electron beam transport

International Nuclear Information System (INIS)

Schneider, R.F.; Smith, J.R.; Moffatt, M.E.; Nguyen, K.T.; Uhm, H.S.

1988-01-01

In recent years, there has been much interest in transport of intense relativistic electron beams using plasma channels. These channels are formed by either: ionization of an organic gas by UV photoionization or electron impact ionization of a low pressure gas utilizing a low energy (typically several hundred volts) electron gun. The second method is discussed here. As their electron gun, the authors used a 12 volt lightbulb filament which is biased to -400 volts with respect to the grounded 15 cm diameter drift tube. The electrons emitted from the filament are confined by an axial magnetic field of --100 Gauss to create a plasma channel which is less than 1 cm in radius. The channel density has been determined with Langmuir probes and the resulting line densities were found to be 10 11 to 10 12 per cm. When a multi-kiloamp electron beam is injected onto this channel, the beam space charge will eject the plasma electrons leaving the ions behind to charge neutralize the electron beam, hence allowing the beam to propagate. In this work, the authors performed experimental studies on the dynamics of the plasma channel. These include Langmuir probe measurements of a steady state (DC) channel, as well as time-resolved Langmuir probe studies of pulsed channels. In addition they performed experimental studies of beam propagation in these plasma channels. Specifically, they observed the behavior of current transport in these channels. Detailed results of beam transport and channel studies are presented

Dimension measuring method for channel box

International Nuclear Information System (INIS)

Jo, Hiroto.

1995-01-01

The device of the present invention concerns detection of a channel box for spent fuel assemblies of a BWR type reactor, which measures a cross sectional shape and dimension of the channel box to check deformation amount such as expansion. That is, a customary fuel exchanger and a dimension measuring device are used. The lower end of the channel box is measured by a distance sensor of the dimension measuring device when it is aligned with a position of the distance sensor. The channel box is lowered at the same time while detecting axial position data of the fuel exchanger. The position of the channel box in an axial direction is detected based on axial position data of the fuel exchanger. The lower end of the channel box can accurately be recognized by the detection of both of them. Subsequent deformation measurement for the channel box at accurate axial positions is enabled. In addition, since the axial position data of the fuel exchanger per se are detected, an axial profile of the channel box can be measured even if a lifting speed of the channel box is varied on every region. (I.S.)

On the low SNR capacity of MIMO fading channels with imperfect channel state information

KAUST Repository

Benkhelifa, Fatma

2014-06-01

The capacity of multiple-input multiple-output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low signal-to-noise ratio (SNR) essentially as SNR log(1/SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In this paper, we mainly focus on the low SNR regime, and we show that the capacity scales as (1-α) SNR log(1/SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can be also extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 1972-2012 IEEE.

On the low SNR capacity of MIMO fading channels with imperfect channel state information

KAUST Repository

Benkhelifa, Fatma

2014-05-01

The capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low Signal-to-Noise Ratio (SNR) essentially as SNR log(1=SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In our work, we mainly focus on the low SNR regime and we show that the capacity scales as (1-α) SNR log(1=SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can also be extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 2014 IFIP.

An Adaptive Channel Estimation Algorithm Using Time-Frequency Polynomial Model for OFDM with Fading Multipath Channels

Directory of Open Access Journals (Sweden)

Liu KJ Ray

2002-01-01

Full Text Available Orthogonal frequency division multiplexing (OFDM is an effective technique for the future 3G communications because of its great immunity to impulse noise and intersymbol interference. The channel estimation is a crucial aspect in the design of OFDM systems. In this work, we propose a channel estimation algorithm based on a time-frequency polynomial model of the fading multipath channels. The algorithm exploits the correlation of the channel responses in both time and frequency domains and hence reduce more noise than the methods using only time or frequency polynomial model. The estimator is also more robust compared to the existing methods based on Fourier transform. The simulation shows that it has more than improvement in terms of mean-squared estimation error under some practical channel conditions. The algorithm needs little prior knowledge about the delay and fading properties of the channel. The algorithm can be implemented recursively and can adjust itself to follow the variation of the channel statistics.

Demystifying Mechanosensitive Piezo Ion Channels.

Science.gov (United States)

Xu, X Z Shawn

2016-06-01

Mechanosensitive channels mediate touch, hearing, proprioception, and blood pressure regulation. Piezo proteins, including Piezo1 and Piezo2, represent a new class of mechanosensitive channels that have been reported to play key roles in most, if not all, of these modalities. The structural architecture and molecular mechanisms by which Piezos act as mechanosensitive channels, however, remain mysterious. Two new studies have now provided critical insights into the atomic structure and molecular basis of the ion permeation and mechano-gating properties of the Piezo1 channel.

Calcium channel blocker overdose

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used ...

VKCDB: Voltage-gated potassium channel database

Directory of Open Access Journals (Sweden)

Gallin Warren J

2004-01-01

Full Text Available Abstract Background The family of voltage-gated potassium channels comprises a functionally diverse group of membrane proteins. They help maintain and regulate the potassium ion-based component of the membrane potential and are thus central to many critical physiological processes. VKCDB (Voltage-gated potassium [K] Channel DataBase is a database of structural and functional data on these channels. It is designed as a resource for research on the molecular basis of voltage-gated potassium channel function. Description Voltage-gated potassium channel sequences were identified by using BLASTP to search GENBANK and SWISSPROT. Annotations for all voltage-gated potassium channels were selectively parsed and integrated into VKCDB. Electrophysiological and pharmacological data for the channels were collected from published journal articles. Transmembrane domain predictions by TMHMM and PHD are included for each VKCDB entry. Multiple sequence alignments of conserved domains of channels of the four Kv families and the KCNQ family are also included. Currently VKCDB contains 346 channel entries. It can be browsed and searched using a set of functionally relevant categories. Protein sequences can also be searched using a local BLAST engine. Conclusions VKCDB is a resource for comparative studies of voltage-gated potassium channels. The methods used to construct VKCDB are general; they can be used to create specialized databases for other protein families. VKCDB is accessible at http://vkcdb.biology.ualberta.ca.

Morphology of channels and channel-sand bodies in the Glauconitic sandstone member (Upper Mannville), Little Bow area, Alberta

Energy Technology Data Exchange (ETDEWEB)

Hopkins, J.C.; Hermanson, S.W.; Lawton, D.C.

1982-12-01

Large channels in the Glauconitic sandstone member of southern Alberta have proved to be difficult exploration targets because of an irregular distribution of reservoir sands within the channels. In the Little Bow area, two channels are present in the lower part of the Glauconitic member and have cut into the underlying Calcareous member. The channels can be recognized where they truncate regional markers of the Calcareous member -- the Bantry shale and Ostracod limestone, and where channel-fill deposits exhibit uniform geophysical log characters, indicating sandstone- or mudstone-filled reaches. Sediments of the Glauconitic member adjacent to the channels comprise a series of splay sandstones and mudstones that prograded into interdistributary bays of the lower delta plain. The two channels associated with these deposits are interpreted as distributary channels. Sand bodies within the channels formed as lateral bars and are isolated by mudstones which mark the abandoned stream course. Geological exploration for these discontinuous channel sandstones is difficult, and high-resolutio seismic data integrated with sound geologic modelling are critical for successful prospect delineation.

A Mathematical Model of Membrane Gas Separation with Energy Transfer by Molecules of Gas Flowing in a Channel to Molecules Penetrating this Channel from the Adjacent Channel

Directory of Open Access Journals (Sweden)

Szwast Maciej

2015-06-01

Full Text Available The paper presents the mathematical modelling of selected isothermal separation processes of gaseous mixtures, taking place in plants using membranes, in particular nonporous polymer membranes. The modelling concerns membrane modules consisting of two channels - the feeding and the permeate channels. Different shapes of the channels cross-section were taken into account. Consideration was given to co-current and counter-current flows, for feeding and permeate streams, respectively, flowing together with the inert gas receiving permeate. In the proposed mathematical model it was considered that pressure of gas changes along the length of flow channels was the result of both - the drop of pressure connected with flow resistance, and energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel. The literature on membrane technology takes into account only the drop of pressure connected with flow resistance. Consideration given to energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel constitute the essential novelty in the current study. The paper also presents results of calculations obtained by means of a computer program which used equations of the derived model. Physicochemical data concerning separation of the CO2/CH4 mixture with He as the sweep gas and data concerning properties of the membrane made of PDMS were assumed for calculations.

Calcium channel blocker poisoning

Directory of Open Access Journals (Sweden)

Miran Brvar

2005-04-01

Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

Channel selection for automatic seizure detection

DEFF Research Database (Denmark)

Duun-Henriksen, Jonas; Kjaer, Troels Wesenberg; Madsen, Rasmus Elsborg

2012-01-01

Objective: To investigate the performance of epileptic seizure detection using only a few of the recorded EEG channels and the ability of software to select these channels compared with a neurophysiologist. Methods: Fifty-nine seizures and 1419 h of interictal EEG are used for training and testing...... of an automatic channel selection method. The characteristics of the seizures are extracted by the use of a wavelet analysis and classified by a support vector machine. The best channel selection method is based upon maximum variance during the seizure. Results: Using only three channels, a seizure detection...... sensitivity of 96% and a false detection rate of 0.14/h were obtained. This corresponds to the performance obtained when channels are selected through visual inspection by a clinical neurophysiologist, and constitutes a 4% improvement in sensitivity compared to seizure detection using channels recorded...

UMTS Common Channel Sensitivity Analysis

DEFF Research Database (Denmark)

Pratas, Nuno; Rodrigues, António; Santos, Frederico

2006-01-01

and as such it is necessary that both channels be available across the cell radius. This requirement makes the choice of the transmission parameters a fundamental one. This paper presents a sensitivity analysis regarding the transmission parameters of two UMTS common channels: RACH and FACH. Optimization of these channels...... is performed and values for the key transmission parameters in both common channels are obtained. On RACH these parameters are the message to preamble offset, the initial SIR target and the preamble power step while on FACH it is the transmission power offset....

Defect Distributions in Channeling Experiments

DEFF Research Database (Denmark)

Andersen, Hans Henrik; Sigmund, P.

1965-01-01

A simple collision model allows to calculate energy losses of perfectly channeled particles. The maximum energy loss is related in a simple way to the displacement energy of lattice atoms perpendicular to the channel. From that, one obtains rather definite predictions on the possibility...... of radiation damage by channeled particles. As an application, one gets a necessary criterion for the occurence of super tails in channeling experiments. The theory involves some assumptions on the behaviour of Born-Mayer potentials which are verified by comparison to experimental displacement energies....

On the ergodic secrecy capacity of the wiretap channel under imperfect main channel estimation

KAUST Repository

Rezki, Zouheir

2011-11-01

The ergodic secrecy capacity of the wiretap channel is known when the main channel (between the transmitter and the legitimate receiver) state information (CSI) is perfect at the transmitter and the coherence period is sufficiently large to enable random coding arguments in each block. In a fast fading scenario, when the codeword length spans many coherence periods, the secrecy capacity is still not known. In this paper, we present a framework that characterizes this secrecy capacity under imperfect main channel estimation at the transmitter. Inner and outer bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate is a simple on-off scheme using a Gaussian input. The upper bound is obtained using an appropriate correlation scheme of the main and the eavesdropper channels. The upper and the lower bounds coincide with recently derived ones in the perfect main CSI extreme. Furthermore, the lower bound matches the upper bound in no main CSI extreme, where the secrecy capacity is equal to zero. Numerical results are provided for independent identically distributed (i.i.d.) Rayleigh fading channels. © 2011 IEEE.

Cholesterol influences voltage-gated calcium channels and BK-type potassium channels in auditory hair cells.

Directory of Open Access Journals (Sweden)

Erin K Purcell

Full Text Available The influence of membrane cholesterol content on a variety of ion channel conductances in numerous cell models has been shown, but studies exploring its role in auditory hair cell physiology are scarce. Recent evidence shows that cholesterol depletion affects outer hair cell electromotility and the voltage-gated potassium currents underlying tall hair cell development, but the effects of cholesterol on the major ionic currents governing auditory hair cell excitability are unknown. We investigated the effects of a cholesterol-depleting agent (methyl beta cyclodextrin, MβCD on ion channels necessary for the early stages of sound processing. Large-conductance BK-type potassium channels underlie temporal processing and open in a voltage- and calcium-dependent manner. Voltage-gated calcium channels (VGCCs are responsible for calcium-dependent exocytosis and synaptic transmission to the auditory nerve. Our results demonstrate that cholesterol depletion reduced peak steady-state calcium-sensitive (BK-type potassium current by 50% in chick cochlear hair cells. In contrast, MβCD treatment increased peak inward calcium current (~30%, ruling out loss of calcium channel expression or function as a cause of reduced calcium-sensitive outward current. Changes in maximal conductance indicated a direct impact of cholesterol on channel number or unitary conductance. Immunoblotting following sucrose-gradient ultracentrifugation revealed BK expression in cholesterol-enriched microdomains. Both direct impacts of cholesterol on channel biophysics, as well as channel localization in the membrane, may contribute to the influence of cholesterol on hair cell physiology. Our results reveal a new role for cholesterol in the regulation of auditory calcium and calcium-activated potassium channels and add to the growing evidence that cholesterol is a key determinant in auditory physiology.

Post-Translational Modifications of TRP Channels

Directory of Open Access Journals (Sweden)

Olaf Voolstra

2014-04-01

Full Text Available Transient receptor potential (TRP channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role.

Optical Communications Channel Combiner

Science.gov (United States)

Quirk, Kevin J.; Quirk, Kevin J.; Nguyen, Danh H.; Nguyen, Huy

2012-01-01

NASA has identified deep-space optical communications links as an integral part of a unified space communication network in order to provide data rates in excess of 100 Mb/s. The distances and limited power inherent in a deep-space optical downlink necessitate the use of photon-counting detectors and a power-efficient modulation such as pulse position modulation (PPM). For the output of each photodetector, whether from a separate telescope or a portion of the detection area, a communication receiver estimates a log-likelihood ratio for each PPM slot. To realize the full effective aperture of these receivers, their outputs must be combined prior to information decoding. A channel combiner was developed to synchronize the log-likelihood ratio (LLR) sequences of multiple receivers, and then combines these into a single LLR sequence for information decoding. The channel combiner synchronizes the LLR sequences of up to three receivers and then combines these into a single LLR sequence for output. The channel combiner has three channel inputs, each of which takes as input a sequence of four-bit LLRs for each PPM slot in a codeword via a XAUI 10 Gb/s quad optical fiber interface. The cross-correlation between the channels LLR time series are calculated and used to synchronize the sequences prior to combining. The output of the channel combiner is a sequence of four-bit LLRs for each PPM slot in a codeword via a XAUI 10 Gb/s quad optical fiber interface. The unit is controlled through a 1 Gb/s Ethernet UDP/IP interface. A deep-space optical communication link has not yet been demonstrated. This ground-station channel combiner was developed to demonstrate this capability and is unique in its ability to process such a signal.

Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

International Nuclear Information System (INIS)

Chung, Pann Pann; Hyne, Ross V.; Mann, Reinier M.; Ballard, J. William O.

2008-01-01

To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor

Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

Energy Technology Data Exchange (ETDEWEB)

Chung, Pann Pann [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia); Hyne, Ross V. [Ecotoxicology and Environmental Contaminants Section, NSW Department of Environment and Climate Change, PO Box 29, Lidcombe, NSW 1825 (Australia); Mann, Reinier M. [Centre for Ecotoxicology, Department of Environmental Sciences, University of Technology-Sydney, C/-PO Box 29, Lidcombe, NSW 1825 (Australia); Ballard, J. William O. [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia)], E-mail: w.ballard@unsw.edu.au

2008-09-15

To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor.

On the capacity of nakagami-m fading Channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2012-06-01

The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log(1/SNR)}. In this paper, we investigate the Nakagami-m fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as m/ Omega SNR log(1/SNR), where m is the Nakagami-m fading parameter and where Ω is the channel mean-square. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by taking m=1. © 2012 IEEE.

Identifying cochlear implant channels with poor electrode-neuron interface: partial tripolar, single-channel thresholds and psychophysical tuning curves.

Science.gov (United States)

Bierer, Julie Arenberg; Faulkner, Kathleen F

2010-04-01

The goal of this study was to evaluate the ability of a threshold measure, made with a restricted electrode configuration, to identify channels exhibiting relatively poor spatial selectivity. With a restricted electrode configuration, channel-to-channel variability in threshold may reflect variations in the interface between the electrodes and auditory neurons (i.e., nerve survival, electrode placement, and tissue impedance). These variations in the electrode-neuron interface should also be reflected in psychophysical tuning curve (PTC) measurements. Specifically, it is hypothesized that high single-channel thresholds obtained with the spatially focused partial tripolar (pTP) electrode configuration are predictive of wide or tip-shifted PTCs. Data were collected from five cochlear implant listeners implanted with the HiRes90k cochlear implant (Advanced Bionics Corp., Sylmar, CA). Single-channel thresholds and most comfortable listening levels were obtained for stimuli that varied in presumed electrical field size by using the pTP configuration for which a fraction of current (sigma) from a center-active electrode returns through two neighboring electrodes and the remainder through a distant indifferent electrode. Forward-masked PTCs were obtained for channels with the highest, lowest, and median tripolar (sigma = 1 or 0.9) thresholds. The probe channel and level were fixed and presented with either the monopolar (sigma = 0) or a more focused pTP (sigma > or = 0.55) configuration. The masker channel and level were varied, whereas the configuration was fixed to sigma = 0.5. A standard, three-interval, two-alternative forced choice procedure was used for thresholds and masked levels. Single-channel threshold and variability in threshold across channels systematically increased as the compensating current, sigma, increased and the presumed electrical field became more focused. Across subjects, channels with the highest single-channel thresholds, when measured with a

Information transfer through quantum channels

International Nuclear Information System (INIS)

Kretschmann, D.

2007-01-01

This PhD thesis represents work done between Aug. 2003 and Dec. 2006 in Reinhard F. Werner's quantum information theory group at Technische Universitaet Braunschweig, and Artur Ekert's Centre for Quantum Computation at the University of Cambridge. My thesis falls into the field of abstract quantum information theory. This work investigates both fundamental properties of quantum channels and their asymptotic capacities for classical as well as quantum information transfer. Stinespring's theorem is the basic structure theorem for quantum channels. It implies that every quantum channel can be represented as a unitary evolution on an enlarged system. In Ch. 3 we present a continuity theorem for Stinespring's representation: two quantum channels are similar if and only if it is possible to find unitary implementations that are likewise similar, with dimension-independent norm bounds. The continuity theorem allows to derive a formulation of the information-disturbance tradeoff in terms of quantum channels, and a continuity estimate for the no-broadcasting principle. In Ch. 4 we then apply the continuity theorem to give a strengthened no-go proof for quantum bit commitment, an important cryptographic primitive. This result also provides a natural characterization of those protocols that fall outside the standard setting of unconditional security, and thus may allow secure bit commitment. We present a new such protocol whose security relies on decoherence in the receiver's lab. Ch. 5 reviews the capacities of quantum channels for the transfer of both classical and quantum information, and investigates several variations in the notion of channel capacity. Memory effects are then investigated in detail in Ch. 6. We advertise a model which is sufficiently general to encompass all causal automata: every quantum process in which the outputs up to any given time t do not depend on the inputs at times t'>t can be represented as a concatenated memory channel. We then explain how

Information transfer through quantum channels

Energy Technology Data Exchange (ETDEWEB)

Kretschmann, D.

2007-03-12

This PhD thesis represents work done between Aug. 2003 and Dec. 2006 in Reinhard F. Werner's quantum information theory group at Technische Universitaet Braunschweig, and Artur Ekert's Centre for Quantum Computation at the University of Cambridge. My thesis falls into the field of abstract quantum information theory. This work investigates both fundamental properties of quantum channels and their asymptotic capacities for classical as well as quantum information transfer. Stinespring's theorem is the basic structure theorem for quantum channels. It implies that every quantum channel can be represented as a unitary evolution on an enlarged system. In Ch. 3 we present a continuity theorem for Stinespring's representation: two quantum channels are similar if and only if it is possible to find unitary implementations that are likewise similar, with dimension-independent norm bounds. The continuity theorem allows to derive a formulation of the information-disturbance tradeoff in terms of quantum channels, and a continuity estimate for the no-broadcasting principle. In Ch. 4 we then apply the continuity theorem to give a strengthened no-go proof for quantum bit commitment, an important cryptographic primitive. This result also provides a natural characterization of those protocols that fall outside the standard setting of unconditional security, and thus may allow secure bit commitment. We present a new such protocol whose security relies on decoherence in the receiver's lab. Ch. 5 reviews the capacities of quantum channels for the transfer of both classical and quantum information, and investigates several variations in the notion of channel capacity. Memory effects are then investigated in detail in Ch. 6. We advertise a model which is sufficiently general to encompass all causal automata: every quantum process in which the outputs up to any given time t do not depend on the inputs at times t'>t can be represented as a concatenated memory

TRP channels: an overview

DEFF Research Database (Denmark)

Pedersen, Stine Falsig; Owsianik, Grzegorz; Nilius, Bernd

2005-01-01

The TRP ("transient receptor potential") family of ion channels now comprises more than 30 cation channels, most of which are permeable for Ca2+, and some also for Mg2+. On the basis of sequence homology, the TRP family can be divided in seven main subfamilies: the TRPC ('Canonical') family......, the TRPV ('Vanilloid') family, the TRPM ('Melastatin') family, the TRPP ('Polycystin') family, the TRPML ('Mucolipin') family, the TRPA ('Ankyrin') family, and the TRPN ('NOMPC') family. The cloning and characterization of members of this cation channel family has exploded during recent years, leading...... to a plethora of data on the roles of TRPs in a variety of tissues and species, including mammals, insects, and yeast. The present review summarizes the most pertinent recent evidence regarding the structural and functional properties of TRP channels, focusing on the regulation and physiology of mammalian TRPs....

On Channel Estimation for OFDM/TDM Using MMSE-FDE in a Fast Fading Channel

Directory of Open Access Journals (Sweden)

Gacanin Haris

2009-01-01

Full Text Available Abstract MMSE-FDE can improve the transmission performance of OFDM combined with time division multiplexing (OFDM/TDM, but knowledge of the channel state information and the noise variance is required to compute the MMSE weight. In this paper, a performance evaluation of OFDM/TDM using MMSE-FDE with pilot-assisted channel estimation over a fast fading channel is presented. To improve the tracking ability against fast fading a robust pilot-assisted channel estimation is presented that uses time-domain filtering on a slot-by-slot basis and frequency-domain interpolation. We derive the mean square error (MSE of the channel estimator and then discuss a tradeoff between improving the tracking ability against fading and the noise reduction. The achievable bit error rate (BER performance is evaluated by computer simulation and compared with conventional OFDM. It is shown that the OFDM/TDM using MMSE-FDE achieves a lower BER and a better tracking ability against fast fading in comparison with conventional OFDM.

A Crash Course in Calcium Channels.

Science.gov (United States)

Zamponi, Gerald W

2017-12-20

Much progress has been made in understanding the molecular physiology and pharmacology of calcium channels. Recently, there have been tremendous advances in learning about calcium channel structure and function through crystallography and cryo-electron microscopy studies. Here, I will give an overview of our knowledge about calcium channels, and highlight two recent studies that give important insights into calcium channel structure.

Effects of dislocations on electron channeling

International Nuclear Information System (INIS)

George, Juby; Pathak, A P

2009-01-01

The phenomenon of electron channeling in a crystal affected by dislocations is considered. Earlier we had considered the quantum aspects of the positron channeling in a crystal bent by dislocations where the effects of longitudinal motion of the particle were also considered along with the transverse motion. In this paper, the effective potential for the electron case is found for the two regions of dislocation-affected channel. There is considerable shift in the potential minima due to dislocations. The frequency and the corresponding spectrum of the channeling radiation due to electrons channeling through the perfect channel and the two regions of dislocation-affected channels are calculated. The spectral distribution of radiation intensity changes with the parameters of dislocation. The continuity of wavefunctions and their derivatives is used at the three boundaries and the reflection and transmission coefficients are found using these boundary conditions in the same way as in the positron case.

Omni channel fashion shopping

NARCIS (Netherlands)

Kemperman, A.D.A.M.; van Delft, L.; Borgers, A.W.J.; Pantano, E.

2015-01-01

This chapter gives insight into consumers' online and offline fashion shopping behavior, consumers' omni-channel usage during the shopping process, and consumer fashion shopper segments. Based on a literature review, omni-channel shopping behavior during the shopping process was operationalized.

Flavonoid Regulation of HCN2 Channels*

Science.gov (United States)

Carlson, Anne E.; Rosenbaum, Joel C.; Brelidze, Tinatin I.; Klevit, Rachel E.; Zagotta, William N.

2013-01-01

The hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels are pacemaker channels whose currents contribute to rhythmic activity in the heart and brain. HCN channels open in response to hyperpolarizing voltages, and the binding of cAMP to their cyclic nucleotide-binding domain (CNBD) facilitates channel opening. Here, we report that, like cAMP, the flavonoid fisetin potentiates HCN2 channel gating. Fisetin sped HCN2 activation and shifted the conductance-voltage relationship to more depolarizing potentials with a half-maximal effective concentration (EC50) of 1.8 μm. When applied together, fisetin and cAMP regulated HCN2 gating in a nonadditive fashion. Fisetin did not potentiate HCN2 channels lacking their CNBD, and two independent fluorescence-based binding assays reported that fisetin bound to the purified CNBD. These data suggest that the CNBD mediates the fisetin potentiation of HCN2 channels. Moreover, binding assays suggest that fisetin and cAMP partially compete for binding to the CNBD. NMR experiments demonstrated that fisetin binds within the cAMP-binding pocket, interacting with some of the same residues as cAMP. Together, these data indicate that fisetin is a partial agonist for HCN2 channels. PMID:24085296

Transportation channels calculation method in MATLAB

International Nuclear Information System (INIS)

Averyanov, G.P.; Budkin, V.A.; Dmitrieva, V.V.; Osadchuk, I.O.; Bashmakov, Yu.A.

2014-01-01

Output devices and charged particles transport channels are necessary components of any modern particle accelerator. They differ both in sizes and in terms of focusing elements depending on particle accelerator type and its destination. A package of transport line designing codes for magnet optical channels in MATLAB environment is presented in this report. Charged particles dynamics in a focusing channel can be studied easily by means of the matrix technique. MATLAB usage is convenient because its information objects are matrixes. MATLAB allows the use the modular principle to build the software package. Program blocks are small in size and easy to use. They can be executed separately or commonly. A set of codes has a user-friendly interface. Transport channel construction consists of focusing lenses (doublets and triplets). The main of the magneto-optical channel parameters are total length and lens position and parameters of the output beam in the phase space (channel acceptance, beam emittance - beam transverse dimensions, particles divergence and image stigmaticity). Choice of the channel operation parameters is based on the conditions for satisfying mutually competing demands. And therefore the channel parameters calculation is carried out by using the search engine optimization techniques.

A Perspective on the MIMO Wiretap Channel

KAUST Repository

Oggier, Frederique; Hassibi, Babak

2015-01-01

A wiretap channel is a communication channel between a transmitter Alice and a legitimate receiver Bob, in the presence of an eavesdropper Eve. The goal of communication is to achieve reliability between Alice and Bob, but also confidentiality despite Eve’s presence. Wiretap channels are declined in all kinds of flavors, depending on the underlying channels used by the three players: discrete memoryless channels, additive Gaussian noise channels, or fading channels, to name a few. In this survey, we focus on the case where the three players use multiple-antenna channels with Gaussian noise to communicate. After summarizing known results for multiple-input–multiple-output (MIMO) channels, both in terms of achievable reliable data rate (capacity) and code design, we introduce the MIMO wiretap channel. We then state the MIMO wiretap capacity, summarize the idea of the proof(s) behind this result, and comment on the insights given by the proofs on the physical meaning of the secrecy capacity. We finally discuss design criteria for MIMO wiretap codes.

A Perspective on the MIMO Wiretap Channel

KAUST Repository

Oggier, Frederique

2015-10-01

A wiretap channel is a communication channel between a transmitter Alice and a legitimate receiver Bob, in the presence of an eavesdropper Eve. The goal of communication is to achieve reliability between Alice and Bob, but also confidentiality despite Eve’s presence. Wiretap channels are declined in all kinds of flavors, depending on the underlying channels used by the three players: discrete memoryless channels, additive Gaussian noise channels, or fading channels, to name a few. In this survey, we focus on the case where the three players use multiple-antenna channels with Gaussian noise to communicate. After summarizing known results for multiple-input–multiple-output (MIMO) channels, both in terms of achievable reliable data rate (capacity) and code design, we introduce the MIMO wiretap channel. We then state the MIMO wiretap capacity, summarize the idea of the proof(s) behind this result, and comment on the insights given by the proofs on the physical meaning of the secrecy capacity. We finally discuss design criteria for MIMO wiretap codes.

MARKETING CHANNELS

Directory of Open Access Journals (Sweden)

Ljiljana Stošić Mihajlović

2014-07-01

Full Text Available Marketing channel is a set of entities and institutions, completion of distribution and marketing activities, attend the efficient and effective networking of producers and consumers. Marketing channels include the total flows of goods, money and information taking place between the institutions in the system of marketing, establishing a connection between them. The functions of the exchange, the physical supply and service activities, inherent in the system of marketing and trade. They represent paths which products and services are moving after the production, which will ultimately end up buying and eating by the user.

Channel Bottom Morphology in the Deltaic Reach of the Song Hau (mekong) River Channel in Vietnam

Science.gov (United States)

Allison, M. A.; Weathers, H. D., III; Meselhe, E. A.

2016-02-01

Boat-based, channel bathymetry and bankline elevation studies were conducted in the tidal and estuarine Mekong River channel using multibeam bathymetry and LIDAR corrected for elevation by RTK satellite positioning. Two mapping campaigns, one at high discharge in October 2014 and one at low discharge in March 2015, were conducted in the lower 100 km reach of the Song Hau distributary channel to (1) examine bottom morphology and its relationship to sediment transport, and (2) to provide information to setup the grid for a multi-dimensional and reduced complexity models of channel hydrodynamics and sediment dynamics. Sand fields were identified in multibeam data by the presence of dunes that were as large as 2-4 m high and 40-80 m wavelength and by clean sands in bottom grabs. Extensive areas of sand at the head and toe of mid-channel islands displayed 10-25 m diameter circular pits that could be correlated with bucket dredge, sand mining activities observed at some of the sites. Large areas of the channel floor were relict (containing little or no modern sediment) in the high discharge campaign, identifiable by the presence of along channel erosional furrows and terraced outcrops along the channel floor and margins. Laterally extensive flat areas were also observed in the channel thalweg. Both these and the relict areas were sampled by bottom grab as stiff silty clays. Complex cross-channel combinations of these morphologies were observed in some transects, suggesting strong bottom steering of tidal and riverine currents. Relative to high discharge, transects above and below the salt penetration limit showed evidence of shallowing in the thalweg and adjacent sloping areas at low discharge in March 2015. This shallowing, combined with the reduced extent of sand fields and furrowed areas, and soft muds in grabs, suggests seasonal trapping of fine grained sediment is occurring by estuarine and tidal circulation.

Interior point decoding for linear vector channels

International Nuclear Information System (INIS)

Wadayama, T

2008-01-01

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem

Interior point decoding for linear vector channels

Energy Technology Data Exchange (ETDEWEB)

Wadayama, T [Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, Aichi, 466-8555 (Japan)], E-mail: wadayama@nitech.ac.jp

2008-01-15

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem.

LDGM Codes for Channel Coding and Joint Source-Channel Coding of Correlated Sources

Directory of Open Access Journals (Sweden)

Javier Garcia-Frias

2005-05-01

Full Text Available We propose a coding scheme based on the use of systematic linear codes with low-density generator matrix (LDGM codes for channel coding and joint source-channel coding of multiterminal correlated binary sources. In both cases, the structures of the LDGM encoder and decoder are shown, and a concatenated scheme aimed at reducing the error floor is proposed. Several decoding possibilities are investigated, compared, and evaluated. For different types of noisy channels and correlation models, the resulting performance is very close to the theoretical limits.

Three-dimensional (3-D) video systems: bi-channel or single-channel optics?

Science.gov (United States)

van Bergen, P; Kunert, W; Buess, G F

1999-11-01

This paper presents the results of a comparison between two different three-dimensional (3-D) video systems, one with single-channel optics, the other with bi-channel optics. The latter integrates two lens systems, each transferring one half of the stereoscopic image; the former uses only one lens system, similar to a two-dimensional (2-D) endoscope, which transfers the complete stereoscopic picture. In our training centre for minimally invasive surgery, surgeons were involved in basic and advanced laparoscopic courses using both a 2-D system and the two 3-D video systems. They completed analog scale questionnaires in order to record a subjective impression of the relative convenience of operating in 2-D and 3-D vision, and to identify perceived deficiencies in the 3-D system. As an objective test, different experimental tasks were developed, in order to measure performance times and to count pre-defined errors made while using the two 3-D video systems and the 2-D system. Using the bi-channel optical system, the surgeon has a heightened spatial perception, and can work faster and more safely than with a single-channel system. However, single-channel optics allow the use of an angulated endoscope, and the free rotation of the optics relative to the camera, which is necessary for some operative applications.

Structure of conducting channel of lightning

International Nuclear Information System (INIS)

Alanakyan, Yu. R.

2013-01-01

The spatial distribution of the plasma density in a lightning channel is studied theoretically. It is shown that the electric-field double layer is formed at the channel boundary. In this case, the electron temperature changes abruptly and ions are accelerated by the electric field of the double layer. The ion momentum flux density is close to the surrounding gas pressure. Cleaning of the channel from heavy particles occurs in particle-exchange processes between the plasma channel and the surrounding air. Hydrogen ions are accumulated inside the expanding channel from the surrounding air, which is enriched by hydrogen-contained molecules. In this case, the plasma channel is unstable and splits to a chain of equidistant bunches of plasma. The hydrogen-enrich bunches burn diffusely after recombination exhibiting the bead lightning behavior

Multi-channel Kondo necklace

International Nuclear Information System (INIS)

Fazekas, P.; Kee Haeyoung.

1993-06-01

A multi-channel generalization of Doniach's Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins τ J , j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig

The elusive character of discontinuous deep-water channels: New insights from Lucia Chica channel system, offshore California

Science.gov (United States)

Maier, K.L.; Fildani, A.; Paull, C.K.; Graham, S.A.; McHargue, T.R.; Caress, D.W.; McGann, M.

2011-01-01

New high-resolution autonomous underwater vehicle (AUV) seafloor images, with 1 m lateral resolution and 0.3 m vertical resolution, reveal unexpected seafloor rugosity and low-relief (thalwegs were interpreted originally from lower-resolution images, but newly acquired AUV data indicate that a single sinuous channel fed a series of discontinuous lower-relief channels. These discontinuous channels were created by at least four avulsion events. Channel relief, defined as the height from the thalweg to the levee crest, controls avulsions and overall stratigraphic architecture of the depositional area. Flowstripped turbidity currents separated into and reactivated multiple channels to create a distributary pattern and developed discontinuous trains of cyclic scours and megaflutes, which may be erosional precursors to continuous channels. The diverse features now imaged in the Lucia Chica channel system (offshore California) are likely common in modern and ancient systems with similar overall morphologies, but have not been previously mapped with lower-resolution detection methods in any of these systems. ?? 2011 Geological Society of America.

Modulation of ERG channels by XE991

DEFF Research Database (Denmark)

Elmedyb, Pernille; Calloe, Kirstine; Schmitt, Nicole

2007-01-01

In neuronal tissue, KCNQ2-5 channels conduct the physiologically important M-current. In some neurones, the M-current may in addition be conducted partly by ERG potassium channels, which have widely overlapping expression with the KCNQ channel subunits. XE991 and linopiridine are known to be stan......In neuronal tissue, KCNQ2-5 channels conduct the physiologically important M-current. In some neurones, the M-current may in addition be conducted partly by ERG potassium channels, which have widely overlapping expression with the KCNQ channel subunits. XE991 and linopiridine are known...... to be standard KCNQ potassium channel blockers. These compounds have been used in many different tissues as specific pharmacological tools to discern native currents conducted by KCNQ channels from other potassium currents. In this article, we demonstrate that ERG1-2 channels are also reversibly inhibited by XE......991 in the micromolar range (EC(50) 107 microM for ERG1). The effect has been characterized in Xenopus laevis oocytes expressing ERG1-2 and in the mammalian HEK293 cell line stably expressing ERG1 channels. The IC(50) values for block of KCNQ channels by XE991 range 1-65 microM. In conclusion, great...

Sediment sorting at a side channel bifurcation

Science.gov (United States)

van Denderen, Pepijn; Schielen, Ralph; Hulscher, Suzanne

2017-04-01

Side channels have been constructed to reduce the flood risk and to increase the ecological value of the river. In various Dutch side channels large aggradation in these channels occurred after construction. Measurements show that the grain size of the deposited sediment in the side channel is smaller than the grain size found on the bed of the main channel. This suggest that sorting occurs at the bifurcation of the side channel. The objective is to reproduce with a 2D morphological model the fining of the bed in the side channel and to study the effect of the sediment sorting on morphodynamic development of the side channel. We use a 2D Delft3D model with two sediment fractions. The first fraction corresponds with the grain size that can be found on the bed of the main channel and the second fraction corresponds with the grain size found in the side channel. With the numerical model we compute several side channel configurations in which we vary the length and the width of the side channel, and the curvature of the upstream channel. From these computations we can derive the equilibrium state and the time scale of the morphodynamic development of the side channel. Preliminary results show that even when a simple sediment transport relation is used, like Engelund & Hansen, more fine sediment enters the side channel than coarse sediment. This is as expected, and is probably related to the bed slope effects which are a function of the Shields parameter. It is expected that by adding a sill at the entrance of the side channel the slope effect increases. This might reduce the amount of coarse sediment which enters the side channel even more. It is unclear whether the model used is able to reproduce the effect of such a sill correctly as modelling a sill and reproducing the correct hydrodynamic and morphodynamic behaviour is not straightforward in a 2D model. Acknowledgements: This research is funded by STW, part of the Dutch Organization for Scientific Research under

Decreasing vortex flux in channels

International Nuclear Information System (INIS)

Migaj, V.K.; Nosova, I.S.

1979-01-01

A new method for reducing vortex flow losses in power plant channels is suggested. The method is based on vortex splitting in vortex flow areas with transverse barriers placed on the channel walls. The upper barrier ends are at the level of the upper boundary of the vortex area and don't protrude to the active flow beyond this boundary. The effectiveness of the method suggested is illustrated taking as an example the investigation of square and flat channels with abrupt widening in one plane, diffusers with widening in one plane, or a rectangualr bend. It is shown that splitting the vortex areas with transverse barriers in the channels results in reduction of hydraulic losses by 10-25%. The above method is characteristic of an extreme simplicity, its application doesn't require changes in the channel shape nor installation of any devices in the flow

Marketing channels and competitive advantage

Directory of Open Access Journals (Sweden)

Jovičić Dragoljub

2005-01-01

Full Text Available Issue that can already be seen and will be very clear in the future is that the central problem in the market of tube caps will not be the product or the price or promotion, but marketing channels. Therefore, the competitive advantage will most probably be built on marketing channels and not the production - as it has been so far, so, the questions of choice functioning and modification of marketing channels, as well as selection of the most appropriate members of channels will become more and more important. Accordingly, it may freely be said that the choice, i.e. the movement of marketing channels represents one of the strategic decisions which has to be made by a company management and which will subsequently very significantly influence the functioning and efficacy of not only the system of distribution, but also the entire business transactions.

Effective IPTV channel management method over heterogeneous environments

Science.gov (United States)

Joo, Hyunchul; Lee, Dai-boong; Song, Hwangjun

2007-09-01

This paper presents an effective IPTV channel management method using SVC (scalable video coding) that considers concurrently both channel zapping time and network utilization. A broadcasting channel is encoded in two-layered bitstream (base-layer channel and enhancement-layer channel) to supply for heterogeneous environments. The proposed algorithm locates only a limited numbers of base-layer channels close to users to reduce the network delay part of channel zapping time and adjusts the length of GOP (group of picture) into each base-layer channel to decrease the video decoding delay part of channel zapping time, which are performed based on user's channel preference information. Finally, the experimental results are provided to show the performance of the proposed schemes.

Channel follower leakage restrictor

International Nuclear Information System (INIS)

Williamson, H.E.; Smith, B.A.

1977-01-01

An improved means is provided to control coolant leakage between the flow channel and the lower tie plate of a nuclear fuel assembly. The means includes an opening in the lower tie plate and a movable element adjacent thereto. The coolant pressure within the tie plate biases the movable means toward the inner surface of the surrounding flow channel to compensate for any movement of the flow channel away from the lower tie plate to thereby control the leakage of coolant flow from the fuel assemblies to the spaces among the fuel assemblies of the core. 9 figures

Dividing Streamline Formation Channel Confluences by Physical Modeling

Directory of Open Access Journals (Sweden)

Minarni Nur Trilita

2010-02-01

Full Text Available Confluence channels are often found in open channel network system and is the most important element. The incoming flow from the branch channel to the main cause various forms and cause vortex flow. Phenomenon can cause erosion of the side wall of the channel, the bed channel scour and sedimentation in the downstream confluence channel. To control these problems needed research into the current width of the branch channel. The incoming flow from the branch channel to the main channel flow bounded by a line distributors (dividing streamline. In this paper, the wide dividing streamline observed in the laboratory using a physical model of two open channels, a square that formed an angle of 30º. Observations were made with a variety of flow coming from each channel. The results obtained in the laboratory observation that the width of dividing streamline flow is influenced by the discharge ratio between the channel branch with the main channel. While the results of a comparison with previous studies showing that the observation in the laboratory is smaller than the results of previous research.

Information geometry of Gaussian channels

International Nuclear Information System (INIS)

Monras, Alex; Illuminati, Fabrizio

2010-01-01

We define a local Riemannian metric tensor in the manifold of Gaussian channels and the distance that it induces. We adopt an information-geometric approach and define a metric derived from the Bures-Fisher metric for quantum states. The resulting metric inherits several desirable properties from the Bures-Fisher metric and is operationally motivated by distinguishability considerations: It serves as an upper bound to the attainable quantum Fisher information for the channel parameters using Gaussian states, under generic constraints on the physically available resources. Our approach naturally includes the use of entangled Gaussian probe states. We prove that the metric enjoys some desirable properties like stability and covariance. As a by-product, we also obtain some general results in Gaussian channel estimation that are the continuous-variable analogs of previously known results in finite dimensions. We prove that optimal probe states are always pure and bounded in the number of ancillary modes, even in the presence of constraints on the reduced state input in the channel. This has experimental and computational implications. It limits the complexity of optimal experimental setups for channel estimation and reduces the computational requirements for the evaluation of the metric: Indeed, we construct a converging algorithm for its computation. We provide explicit formulas for computing the multiparametric quantum Fisher information for dissipative channels probed with arbitrary Gaussian states and provide the optimal observables for the estimation of the channel parameters (e.g., bath couplings, squeezing, and temperature).

CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.

Science.gov (United States)

Simon, Andrew; Hupp, Cliff R.

1987-01-01

This study (a) assesses the channel changes and network trends of bed level response after modifications between 1959 and 1972 of alluvial channels in western Tennessee and (b) develops a conceptual model of bank slope development to qualitatively assess bank stability and potential channel widening. A six-step, semiquantitative model of channel evolution in disturbed channels was developed by quantifying bed level trends and recognizing qualitative stages of bank slope development. Development of the bank profile is defined in terms of three dynamic and observable surfaces: (a) vertical face (70 to 90 degrees), (b) upper bank (25 to 50 degrees), and (c) slough line (20 to 25 degrees).

Multi-channel Kondo necklace

Energy Technology Data Exchange (ETDEWEB)

Fazekas, P; Haeyoung, Kee

1993-06-01

A multi-channel generalization of Doniach`s Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins {tau}{sub J}, j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig.

Stream Channel Stability.

Science.gov (United States)

1981-04-01

Cycles of wetting and drying are also t ,v itiue swelling and shrinkage of the soil. S 11ied blocks or peds of soil fabric ,,ks. id downslope soil creep ...hydrographs of water and sediment at the point in question. By feeding the output from the hydrology-transport model into the finite element model...the banks as undercut banks fail. Channel irregularities such as seepage zones, cattle crossings, overbank drainage, buried channels, organic deposits

Mode Switching for the Multi-Antenna Broadcast Channel Based on Delay and Channel Quantization

Directory of Open Access Journals (Sweden)

Jun Zhang

2009-01-01

Full Text Available Imperfect channel state information degrades the performance of multiple-input multiple-output (MIMO communications; its effects on single-user (SU and multiuser (MU MIMO transmissions are quite different. In particular, MU-MIMO suffers from residual interuser interference due to imperfect channel state information while SU-MIMO only suffers from a power loss. This paper compares the throughput loss of both SU and MU-MIMO in the broadcast channel due to delay and channel quantization. Accurate closed-form approximations are derived for achievable rates for both SU and MU-MIMO. It is shown that SU-MIMO is relatively robust to delayed and quantized channel information, while MU-MIMO with zero-forcing precoding loses its spatial multiplexing gain with a fixed delay or fixed codebook size. Based on derived achievable rates, a mode switching algorithm is proposed, which switches between SU and MU-MIMO modes to improve the spectral efficiency based on average signal-to-noise ratio (SNR, normalized Doppler frequency, and the channel quantization codebook size. The operating regions for SU and MU modes with different delays and codebook sizes are determined, and they can be used to select the preferred mode. It is shown that the MU mode is active only when the normalized Doppler frequency is very small, and the codebook size is large.

Channel box dimension measuring method

International Nuclear Information System (INIS)

Oshima, Hirotake; Jo, Hiroto.

1994-01-01

The present invention provides a method for measuring the entire length of a channel box of a fuel assembly of a BWR type reactor. Namely, four sensors are used as one set that generate ultrasonic waves from oblique upper portion, oblique lower portion, upper portion and lower portion of the channel box respectively. The distances between the four sensors and each of the portions of the channel box are measured respectively for both of a reference member and a member to be measured. The entire length of the channel box is measured by calculating the measured values and the angles of the obliquely disposed sensors according to a predetermined formula. According to the method of the present invention, the inclination of the channel box to be measured can be corrected. In addition, accuracy of the measurement is improved and the measuring time is saved as well as the measuring device and operation can be simplified. (I.S.)

The Citizen Observatory of Radioactivity - Assessment for 2010 of radioactivity survey in the environment at the scale of Normandy (coast and waterways) - Results of measurement of gamma emitters and of Tritium in water

International Nuclear Information System (INIS)

2012-01-01

This document proposes a set of tables containing different information and data regarding measurements of gamma radioactivity and of the presence of tritium made during 2010 in different marine and water environments (algae, sands, sea water, molluscs, sediments, water mosses, vegetal) in different locations: a bay close to the AREVA plant in La Hague, different locations on the Normandy coast, around the AREVA plant in La Hague, and in waterways in Normandy. These tables contain information about the sampling (date, location, quantity, analysed fraction, and so on) and results of measurements of artificial (isotopes of cobalt, ruthenium-rhodium, silver, iodine, caesium, americium, europium) and natural (potassium, beryllium, lead, bismuth, etc.) radionuclides

Quantum capacity of Pauli channels with memory

International Nuclear Information System (INIS)

Huang Peng; He Guangqiang; Lu Yuan; Zeng Guihua

2011-01-01

The amount of coherent quantum information that can be reliably transmitted down the memory Pauli channels with Markovian correlated noise is investigated. Two methods for evaluating the quantum capacity of the memory Pauli channels are proposed to try to trace the memory effect on the transmissions of quantum information. We show that the evaluation of quantum capacity can be reduced to the calculation of the initial memory state of each successive transmission. Furthermore, we derive quantum capacities of the memory phase flip channel, bit flip channel and bit-phase flip channel. Also, a lower bound of the quantum capacity of the memory depolarizing channel is obtained. An increase of the degree of memory of the channels has a positive effect on the increase of their quantum capacities.

Flooding correlations in narrow channel

International Nuclear Information System (INIS)

Kim, S. H.; Baek, W. P.; Chang, S. H.

1999-01-01

Heat transfer in narrow gap is considered as important phenomena in severe accidents in nuclear power plants. Also in heat removal of electric chip. Critical heat flux(CHF) in narrow gap limits the maximum heat transfer rate in narrow channel. In case of closed bottom channel, flooding limited CHF occurrence is observed. Flooding correlations will be helpful to predict the CHF in closed bottom channel. In present study, flooding data for narrow channel geometry were collected and the work to recognize the effect of the span, w and gap size, s were performed. And new flooding correlations were suggested for high-aspect-ratio geometry. Also, flooding correlation was applied to flooding limited CHF data

Transient receptor potential channels in essential hypertension

DEFF Research Database (Denmark)

Liu, Daoyan; Scholze, Alexandra; Zhu, Zhiming

2006-01-01

The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated.......The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated....

On the secrecy capacity of the broadcast wiretap channel with imperfect channel state information

KAUST Repository

Hyadi, Amal

2014-12-01

In this paper, we consider secure broadcasting over fast fading channels. Assuming imperfect main channel state information (CSI) at the transmitter, we first provide an upper and a lower bounds on the ergodic secrecy capacity when a common message is broadcasted to multiple legitimate receivers in the presence of one eavesdropper. For this case, we show that the secrecy rate is limited by the legitimate receiver having, on average, the worst main channel link. Then, we present an expression for the achievable secrecy sum-rate when each legitimate receiver is interested in an independent message. The special cases of high SNR, perfect and no-main CSI are also analyzed. Numerical results are presented to illustrate the obtained results for the case of independent but not necessarily identically distributed Rayleigh fading channels.

Hydrodynamic cavitation in micro channels with channel sizes of 100 and 750 micrometers

NARCIS (Netherlands)

Rooze, J.; Andre, M.; Gulik, van der G.J.S.; Fernandez-Rivas, D.; Gardeniers, J.G.E.; Rebrov, E.; Schouten, J.C.; Keurentjes, J.T.F.

2012-01-01

Decreasing the constriction size and residence time in hydrodynamic cavitation is predicted to give increased hot spot temperatures at bubble collapse and increased radical formation rate. Cavitation in a 100 × 100 µm2 rectangular micro channel and in a circular 750 µm diameter milli channel has

Multi-reaction-channel fitting calculations in a coupled-channel model : Photoinduced strangeness production

NARCIS (Netherlands)

Scholten, O.; Usov, A.

To describe photo- and meson-induced reactions on the nucleon, one is faced with a rather extensive coupled-channel problem Ignoring the effects of channel coupling, as one would do in describing a certain reaction at the tree level; invariably creates a large inconsistency between the different

Grafting voltage and pharmacological sensitivity in potassium channels.

Science.gov (United States)

Lan, Xi; Fan, Chunyan; Ji, Wei; Tian, Fuyun; Xu, Tao; Gao, Zhaobing

2016-08-01

A classical voltage-gated ion channel consists of four voltage-sensing domains (VSDs). However, the roles of each VSD in the channels remain elusive. We developed a GVTDT (Graft VSD To Dimeric TASK3 channels that lack endogenous VSDs) strategy to produce voltage-gated channels with a reduced number of VSDs. TASK3 channels exhibit a high host tolerance to VSDs of various voltage-gated ion channels without interfering with the intrinsic properties of the TASK3 selectivity filter. The constructed channels, exemplified by the channels grafted with one or two VSDs from Kv7.1 channels, exhibit classical voltage sensitivity, including voltage-dependent opening and closing. Furthermore, the grafted Kv7.1 VSD transfers the potentiation activity of benzbromarone, an activator that acts on the VSDs of the donor channels, to the constructed channels. Our study indicates that one VSD is sufficient to voltage-dependently gate the pore and provides new insight into the roles of VSDs.

On the capacity of Rician fading channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2012-06-01

The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log (1/SNR). In this paper, we investigate the Rician fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as 1/1+K SNR log (1 /SNR), where K is the Rician factor. This characterization includes perfect CSI at both the transmitter and the receiver or noisy CSI at the transmitter and perfect CSI at the receiver. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by letting K goes to zero. © 2012 IEEE.

Quantum Correlations Evolution Asymmetry in Quantum Channels

International Nuclear Information System (INIS)

Li Meng; Huang Yun-Feng; Guo Guang-Can

2017-01-01

It was demonstrated that the entanglement evolution of a specially designed quantum state in the bistochastic channel is asymmetric. In this work, we generalize the study of the quantum correlations, including entanglement and quantum discord, evolution asymmetry to various quantum channels. We found that the asymmetry of entanglement and quantum discord only occurs in some special quantum channels, and the behavior of the entanglement evolution may be quite different from the behavior of the quantum discord evolution. To quantum entanglement, in some channels it decreases monotonously with the increase of the quantum channel intensity. In some other channels, when we increase the intensity of the quantum channel, it decreases at first, then keeps zero for some time, and then rises up. To quantum discord, the evolution becomes more complex and you may find that it evolutes unsmoothly at some points. These results illustrate the strong dependence of the quantum correlations evolution on the property of the quantum channels. (paper)

Consolidation equipment for irradiated nuclear fuel channels

International Nuclear Information System (INIS)

Taguchi, M.; Komatsu, Y.; Ose, T.

1989-01-01

The authors have developed and put into use a new type of mechanical consolidation equipment for irradiated nuclear fuel channels. This includes round-slice cutting of the top 100mm of the fuel channel with a guillotine cutter, and press cutting of the two corners of the remaining length of the fuel channel. Four guillotine blades work in combination with receiving blades arranged inside the fuel channel to cut the top 100mm, including the clips and spacers, of the fuel channel into a round slice. A press assembled in the consolidation equipment then presses the slice to achieve volume reduction. The press cutting operation uses two press cutting blades arranged inside the fuel channel and the receiving blades outside the fuel channel. The remaining length of fuel channel is cut off into L-shaped pieces by press cutting. This consolidation equipment is highly efficient because the round-slice cutting, pressing, and press cutting are all achieved by one unit

Mechanosensitive Channels: In Touch with Piezo

OpenAIRE

Xiao, Rui; Xu, X.Z. Shawn

2010-01-01

Mechanosensory transduction underlies touch, hearing and proprioception and requires mechanosensitive channels that are directly gated by forces; however, the molecular identities of these channels remain largely elusive. A new study has identified Piezo1 and Piezo2 as a novel class of mechanosensitive channels.

Channelling versus inversion

DEFF Research Database (Denmark)

Gale, A.S.; Surlyk, Finn; Anderskouv, Kresten

2013-01-01

Evidence from regional stratigraphical patterns in Santonian−Campanian chalk is used to infer the presence of a very broad channel system (5 km across) with a depth of at least 50 m, running NNW−SSE across the eastern Isle of Wight; only the western part of the channel wall and fill is exposed. W......−Campanian chalks in the eastern Isle of Wight, involving penecontemporaneous tectonic inversion of the underlying basement structure, are rejected....

Trade-off capacities of the quantum Hadamard channels

International Nuclear Information System (INIS)

Bradler, Kamil; Hayden, Patrick; Touchette, Dave; Wilde, Mark M.

2010-01-01

Coding theorems in quantum Shannon theory express the ultimate rates at which a sender can transmit information over a noisy quantum channel. More often than not, the known formulas expressing these transmission rates are intractable, requiring an optimization over an infinite number of uses of the channel. Researchers have rarely found quantum channels with a tractable classical or quantum capacity, but when such a finding occurs, it demonstrates a complete understanding of that channel's capabilities for transmitting classical or quantum information. Here we show that the three-dimensional capacity region for entanglement-assisted transmission of classical and quantum information is tractable for the Hadamard class of channels. Examples of Hadamard channels include generalized dephasing channels, cloning channels, and the Unruh channel. The generalized dephasing channels and the cloning channels are natural processes that occur in quantum systems through the loss of quantum coherence or stimulated emission, respectively. The Unruh channel is a noisy process that occurs in relativistic quantum information theory as a result of the Unruh effect and bears a strong relationship to the cloning channels. We give exact formulas for the entanglement-assisted classical and quantum communication capacity regions of these channels. The coding strategy for each of these examples is superior to a naieve time-sharing strategy, and we introduce a measure to determine this improvement.

On the capacity of multiaccess fading channels with full channel state information at low power regime

KAUST Repository

Rezki, Zouheir

2013-06-01

We study the throughput capacity region of the Gaussian multiaccess (MAC) fading channel with perfect channel state information (CSI) at the receiver (CSI-R) and at the transmitters (CSI-T), at low power regime. We show that it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power regime, the boundary surface of the capacity region shrinks to a single point corresponding to the sum rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Inspired from this result, we propose an on-off scheme, compute its achievable rate, and provide a necessary condition on the fading channels under which this scheme achieves single user capacity bounds of the MAC channel at asymptotically low power regime. We argue that this necessary condition characterizes a class of fading that encompasses all known wireless channels, where the capacity region of the MAC channel has a simple expression in terms of users\\' average power constraints only. © 2013 IEEE.

Bandwidth efficient channel estimation method for airborne hyperspectral data transmission in sparse doubly selective communication channels

Science.gov (United States)

Vahidi, Vahid; Saberinia, Ebrahim; Regentova, Emma E.

2017-10-01

A channel estimation (CE) method based on compressed sensing (CS) is proposed to estimate the sparse and doubly selective (DS) channel for hyperspectral image transmission from unmanned aircraft vehicles to ground stations. The proposed method contains three steps: (1) the priori estimate of the channel by orthogonal matching pursuit (OMP), (2) calculation of the linear minimum mean square error (LMMSE) estimate of the received pilots given the estimated channel, and (3) estimate of the complex amplitudes and Doppler shifts of the channel using the enhanced received pilot data applying a second round of a CS algorithm. The proposed method is named DS-LMMSE-OMP, and its performance is evaluated by simulating transmission of AVIRIS hyperspectral data via the communication channel and assessing their fidelity for the automated analysis after demodulation. The performance of the DS-LMMSE-OMP approach is compared with that of two other state-of-the-art CE methods. The simulation results exhibit up to 8-dB figure of merit in the bit error rate and 50% improvement in the hyperspectral image classification accuracy.

Planar channeling in superlattices: Theory

International Nuclear Information System (INIS)

Ellison, J.A.; Picraux, S.T.; Allen, W.R.; Chu, W.K.

1988-01-01

The well-known continuum model theory for planar channeled energetic particles in perfect crystals is extended to layered crystalline structures and applied to superlattices. In a strained-layer structure, the planar channels with normals which are not perpendicular to the growth direction change their direction at each interface, and this dramatically influences the channeling behavior. The governing equation of motion for a planar channeled ion in a strained-layer superlattice with equal layer thicknesses is a one degree of freedom nonlinear oscillator which is periodically forced with a sequence of δ functions. These δ functions, which are of equal spacing and amplitude with alternating sign, represent the tilts at each of the interfaces. Thus upon matching an effective channeled particle wavelength, corresponding to a natural period of the nonlinear oscillator, to the period of the strained-layer superlattice, corresponding to the periodic forcing, strong resonance effects are expected. The condition of one effective wavelength per period corresponds to a rapid dechanneling at a well-defined depth (catastrophic dechanneling), whereas two wavelengths per period corresponds to no enhanced dechanneling after the first one or two layers (resonance channeling). A phase plane analysis is used to characterize the channeled particle motion. Detailed calculations using the Moliere continuum potential are compared with our previously described modified harmonic model, and new results are presented for the phase plane evolution, as well as the dechanneling as a function of depth, incident angle, energy, and layer thickness. General scaling laws are developed and nearly universal curves are obtained for the dechanneling versus depth under catastrophic dechanneling

Anion channels: master switches of stress responses.

Science.gov (United States)

Roelfsema, M Rob G; Hedrich, Rainer; Geiger, Dietmar

2012-04-01

During stress, plant cells activate anion channels and trigger the release of anions across the plasma membrane. Recently, two new gene families have been identified that encode major groups of anion channels. The SLAC/SLAH channels are characterized by slow voltage-dependent activation (S-type), whereas ALMT genes encode rapid-activating channels (R-type). Both S- and R-type channels are stimulated in guard cells by the stress hormone ABA, which leads to stomatal closure. Besides their role in ABA-dependent stomatal movement, anion channels are also activated by biotic stress factors such as microbe-associated molecular patterns (MAMPs). Given that anion channels occur throughout the plant kingdom, they are likely to serve a general function as master switches of stress responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evolutionary origins of mechanosensitive ion channels.

Science.gov (United States)

Martinac, Boris; Kloda, Anna

2003-01-01

According to the recent revision, the universal phylogenetic tree is composed of three domains: Eukarya (eukaryotes), Bacteria (eubacteria) and Archaea (archaebacteria). Mechanosensitive (MS) ion channels have been documented in cells belonging to all three domains suggesting their very early appearance during evolution of life on Earth. The channels show great diversity in conductance, selectivity and voltage dependence, while sharing the property of being gated by mechanical stimuli exerted on cell membranes. In prokaryotes, MS channels were first documented in Bacteria followed by their discovery in Archaea. The finding of MS channels in archaeal cells helped to recognize and establish the evolutionary relationship between bacterial and archaeal MS channels and to show that this relationship extends to eukaryotic Fungi (Schizosaccharomyces pombe) and Plants (Arabidopsis thaliana). Similar to their bacterial and archaeal homologues, MS channels in eukaryotic cell-walled Fungi and Plants may serve in protecting the cellular plasma membrane from excessive dilation and rupture that may occur during osmotic stress. This review summarizes briefly some of the recent developments in the MS channel research field that may ultimately lead to elucidation of the biophysical and evolutionary principles underlying the mechanosensory transduction in living cells.

Geometric Modeling of the Machine for Cutting Cane and Other Aquatic Plants in Navigable Waterways by Agustín de Betancourt y Molina

Directory of Open Access Journals (Sweden)

José Ignacio Rojas-Sola

2018-02-01

Full Text Available This article presents the steps followed to obtain a three-dimensional model of one of the most recognized historical inventions of Agustín de Betancourt y Molina from the scant documentation found about it. Specifically, this was a machine for cutting cane and other aquatic plants in navigable waterways, presented in London in 1795. The study is based on computer-aided design (CAD techniques using Autodesk Inventor Professional, from the information provided by the only two sheets that exist from the machine, one with specifications in English and the other in French, both very similar. In order to obtain a functional result on which to carry out further studies, it has been necessary to make some geometrical hypotheses on the models, aimed to find the correct dimension of each element. In addition, it has also been necessary to define the relationship of each element with those that set up its environment, defining movement restrictions, so that the final model, behaves as real as possible.

Radio propagation measurement and channel modelling

CERN Document Server

Salous, Sana

2013-01-01

While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

Hydrodynamic cavitation in micro channels with channel sizes of 100 and 750 micrometers

NARCIS (Netherlands)

Rooze, J.; André, M.; van der Gulik, G-J.S.; Fernandez Rivas, David; Gardeniers, Johannes G.E.; Rebrov, E.V.; Schouten, J.C.; Keurentjes, J.T.F.

2012-01-01

Decreasing the constriction size and residence time in hydrodynamic cavitation is predicted to give increased hot spot temperatures at bubble collapse and increased radical formation rate. Cavitation in a 100 × 100 μm2 rectangular micro channel and in a circular 750 μm diameter milli channel has

Electronic Commerce and Retail Channel Substitution

NARCIS (Netherlands)

M.C.W. Janssen (Maarten); R. van der Noll

2002-01-01

textabstractWe analyze a market where firms compete in a conventional and an electronic retail channel. Consumers easily compare prices online, but some incur purchase uncertainties on the online channel. We investigate the market shares of the two retail channels and the prices that are charged. We

About Some Aspects of Development of the Domestic Market of Services of the Waterway Transport

Directory of Open Access Journals (Sweden)

Marina V. Kogan

2015-06-01

Full Text Available One of fundamental factors of development of national economy in modern conditions is a transport complex of the country. The analysis shows, historically raising of many developed countries in many respects was provided with concentration of the state transport policy on optimization of conditions for creation of mass, large-scale transportations that is caused by the acceleration of technical progress involving the growing need of economy for increase in speed of transportations, the tonnage of vehicles, etc. Territorial reserves of Russia demand harmonious development of all transport complex, including, railway, automobile, air, water. Shows world experiment, in the countries with such abundance of the rivers, waterways as in Russia one of decisive factors of growth of volumes of transportation of goods and passengers, increase of efficiency of deliveries in scales of all national economy, is the maximum use of a water transport which, other things being equal, manages to the state tens times cheaper than the contents automobile and the railroads. Currently time for the domestic market of transport services, unlike world, lack of close integration and interrelations in the form of commodity transport complexes with presence of managing directors of the transport centers influencing formation of tariff policy is characteristic. At the same time the analysis of productivity of a package of measures of tax support of navigation in the Russian Federation, implementation of the FTP "Development of transport system of Russia (2010 - 2020gody" according to the Concept of long-term social and economic development of the country till 2020 shows their efficiency that is confirmed by positive dynamics of indicators of economic activity of shipping companies, revival of ship-building branch, existence of multiplicative effect due to development of allied industries, revival of business, creation of additional workplaces.

KATP Channels in the Cardiovascular System.

Science.gov (United States)

Foster, Monique N; Coetzee, William A

2016-01-01

KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease. Copyright © 2016 the American Physiological Society.

Applying alpha-channeling to mirror machines

Energy Technology Data Exchange (ETDEWEB)

Zhmoginov, A. I.; Fisch, N. J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States)

2012-05-15

The {alpha}-channeling effect entails the use of radio-frequency waves to expel and cool high-energetic {alpha} particles born in a fusion reactor; the device reactivity can then be increased even further by redirecting the extracted energy to fuel ions. Originally proposed for tokamaks, this technique has also been shown to benefit open-ended fusion devices. Here, the fundamental theory and practical aspects of {alpha} channeling in mirror machines are reviewed, including the influence of magnetic field inhomogeneity and the effect of a finite wave region on the {alpha}-channeling mechanism. For practical implementation of the {alpha}-channeling effect in mirror geometry, suitable contained weakly damped modes are identified. In addition, the parameter space of candidate waves for implementing the {alpha}-channeling effect can be significantly extended through the introduction of a suitable minority ion species that has the catalytic effect of moderating the transfer of power from the {alpha}-channeling wave to the fuel ions.

Improved Sparse Channel Estimation for Cooperative Communication Systems

Directory of Open Access Journals (Sweden)

Guan Gui

2012-01-01

Full Text Available Accurate channel state information (CSI is necessary at receiver for coherent detection in amplify-and-forward (AF cooperative communication systems. To estimate the channel, traditional methods, that is, least squares (LS and least absolute shrinkage and selection operator (LASSO, are based on assumptions of either dense channel or global sparse channel. However, LS-based linear method neglects the inherent sparse structure information while LASSO-based sparse channel method cannot take full advantage of the prior information. Based on the partial sparse assumption of the cooperative channel model, we propose an improved channel estimation method with partial sparse constraint. At first, by using sparse decomposition theory, channel estimation is formulated as a compressive sensing problem. Secondly, the cooperative channel is reconstructed by LASSO with partial sparse constraint. Finally, numerical simulations are carried out to confirm the superiority of proposed methods over global sparse channel estimation methods.

Green channel cargo inspection system

International Nuclear Information System (INIS)

Shi Yuanping; Yu Jingsheng; Sun Hongqiang; Hao Pu; Cai Wenxia

2011-01-01

A radiation detection device was installed in the lanes of a highway toll station, radioactive rays which was collimated emitted through the measured, and arrived the detector. The average density of the fresh agricultural products belonged to Green channel and other prohibited items vary greatly, the absorption of radiation are different between the Green Channel Cargo and other substances. Prior to the experimental group, different standard samples which represent different models and goods were measured, the different standard samples were stored in a computer database. When the trucks get through the Green Channel, the detector will detect the radiation signal and bring to the computer, the computer will process the measured data, and make a conclusion whether the goods are Green Channel cargo. (authors)

Mechanosensitive Piezo Channels in the Gastrointestinal Tract.

Science.gov (United States)

Alcaino, C; Farrugia, G; Beyder, A

2017-01-01

Sensation of mechanical forces is critical for normal function of the gastrointestinal (GI) tract and abnormalities in mechanosensation are linked to GI pathologies. In the GI tract there are several mechanosensitive cell types-epithelial enterochromaffin cells, intrinsic and extrinsic enteric neurons, smooth muscle cells and interstitial cells of Cajal. These cells use mechanosensitive ion channels that respond to mechanical forces by altering transmembrane ionic currents in a process called mechanoelectrical coupling. Several mechanosensitive ionic conductances have been identified in the mechanosensory GI cells, ranging from mechanosensitive voltage-gated sodium and calcium channels to the mechanogated ion channels, such as the two-pore domain potassium channels K2P (TREK-1) and nonselective cation channels from the transient receptor potential family. The recently discovered Piezo channels are increasingly recognized as significant contributors to cellular mechanosensitivity. Piezo1 and Piezo2 are nonselective cationic ion channels that are directly activated by mechanical forces and have well-defined biophysical and pharmacologic properties. The role of Piezo channels in the GI epithelium is currently under investigation and their role in the smooth muscle syncytium and enteric neurons is still not known. In this review, we outline the current state of knowledge on mechanosensitive ion channels in the GI tract, with a focus on the known and potential functions of the Piezo channels. Copyright © 2017 Elsevier Inc. All rights reserved.

Upgrading a marketing channels role

Directory of Open Access Journals (Sweden)

Tišma-Borota Ankica

2002-01-01

Full Text Available As one of the marketing mix instruments, marketing channels were usually behind other instruments (product, price and promotion. Many companies regarded marketing channels as something that was 'left' after more important strategies of price, product and promotion were created. In recent past, things have changed and marketing channels became more interesting for research. This change came as a result of change in global market functioning especially in competitive advantage, distributors' strength and increasing technology.

Calcium homeostasis modulator (CALHM) ion channels.

Science.gov (United States)

Ma, Zhongming; Tanis, Jessica E; Taruno, Akiyuki; Foskett, J Kevin

2016-03-01

Calcium homeostasis modulator 1 (CALHM1), formerly known as FAM26C, was recently identified as a physiologically important plasma membrane ion channel. CALHM1 and its Caenorhabditis elegans homolog, CLHM-1, are regulated by membrane voltage and extracellular Ca(2+) concentration ([Ca(2+)]o). In the presence of physiological [Ca(2+)]o (∼1.5 mM), CALHM1 and CLHM-1 are closed at resting membrane potentials but can be opened by strong depolarizations. Reducing [Ca(2+)]o increases channel open probability, enabling channel activation at negative membrane potentials. Together, voltage and Ca(2+) o allosterically regulate CALHM channel gating. Through convergent evolution, CALHM has structural features that are reminiscent of connexins and pannexins/innexins/LRRC8 (volume-regulated anion channel (VRAC)) gene families, including four transmembrane helices with cytoplasmic amino and carboxyl termini. A CALHM1 channel is a hexamer of CALHM1 monomers with a functional pore diameter of ∼14 Å. CALHM channels discriminate poorly among cations and anions, with signaling molecules including Ca(2+) and ATP able to permeate through its pore. CALHM1 is expressed in the brain where it plays an important role in cortical neuron excitability induced by low [Ca(2+)]o and in type II taste bud cells in the tongue that sense sweet, bitter, and umami tastes where it functions as an essential ATP release channel to mediate nonsynaptic neurotransmitter release. CLHM-1 is expressed in C. elegans sensory neurons and body wall muscles, and its genetic deletion causes locomotion defects. Thus, CALHM is a voltage- and Ca(2+) o-gated ion channel, permeable to large cations and anions, that plays important roles in physiology.

The minimum yield in channeling

International Nuclear Information System (INIS)

Uguzzoni, A.; Gaertner, K.; Lulli, G.; Andersen, J.U.

2000-01-01

A first estimate of the minimum yield was obtained from Lindhard's theory, with the assumption of a statistical equilibrium in the transverse phase-space of channeled particles guided by a continuum axial potential. However, computer simulations have shown that this estimate should be corrected by a fairly large factor, C (approximately equal to 2.5), called the Barrett factor. We have shown earlier that the concept of a statistical equilibrium can be applied to understand this result, with the introduction of a constraint in phase-space due to planar channeling of axially channeled particles. Here we present an extended test of these ideas on the basis of computer simulation of the trajectories of 2 MeV α particles in Si. In particular, the gradual trend towards a full statistical equilibrium is studied. We also discuss the introduction of this modification of standard channeling theory into descriptions of the multiple scattering of channeled particles (dechanneling) by a master equation and show that the calculated minimum yields are in very good agreement with the results of a full computer simulation

On the ergodic secrecy capacity of the wiretap channel under imperfect main channel estimation

KAUST Repository

Rezki, Zouheir; Khisti, Ashish J.; Alouini, Mohamed-Slim

2011-01-01

imperfect main channel estimation at the transmitter. Inner and outer bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate is a simple on-off scheme using a

Gabapentin Modulates HCN4 Channel Voltage-Dependence

Directory of Open Access Journals (Sweden)

Han-Shen Tae

2017-08-01

Full Text Available Gabapentin (GBP is widely used to treat epilepsy and neuropathic pain. There is evidence that GBP can act on hyperpolarization-activated cation (HCN channel-mediated Ih in brain slice experiments. However, evidence showing that GBP directly modulates HCN channels is lacking. The effect of GBP was tested using two-electrode voltage clamp recordings from human HCN1, HCN2, and HCN4 channels expressed in Xenopus oocytes. Whole-cell recordings were also made from mouse spinal cord slices targeting either parvalbumin positive (PV+ or calretinin positive (CR+ inhibitory neurons. The effect of GBP on Ih was measured in each inhibitory neuron population. HCN4 expression was assessed in the spinal cord using immunohistochemistry. When applied to HCN4 channels, GBP (100 μM caused a hyperpolarizing shift in the voltage of half activation (V1/2 thereby reducing the currents. Gabapentin had no impact on the V1/2 of HCN1 or HCN2 channels. There was a robust increase in the time to half activation for HCN4 channels with only a small increase noted for HCN1 channels. Gabapentin also caused a hyperpolarizing shift in the V1/2 of Ih measured from HCN4-expressing PV+ inhibitory neurons in the spinal dorsal horn. Gabapentin had minimal effect on Ih recorded from CR+ neurons. Consistent with this, immunohistochemical analysis revealed that the majority of CR+ inhibitory neurons do not express somatic HCN4 channels. In conclusion, GBP reduces HCN4 channel-mediated currents through a hyperpolarized shift in the V1/2. The HCN channel subtype selectivity of GBP provides a unique tool for investigating HCN4 channel function in the central nervous system. The HCN4 channel is a candidate molecular target for the acute analgesic and anticonvulsant actions of GBP.

Laboratory Experiments on Meandering Meltwater Channels

Science.gov (United States)

Fernandez, R.; Berens, J.; Parker, G.; Stark, C. P.

2017-12-01

Meandering channels of all scales and flowing over a wide variety of media have common planform patterns. Although the analogy in planform suggests there is a common underlying framework, the constitutive relations driving planform evolution through vertical incision/deposition and lateral migration differ from medium to medium. The driving processes in alluvial and mixed bedrock-alluvial meandering channels have been studied substantially over the last decades. However, this is not the case for meandering channels in other media such as ice or soluble rock. Here we present results from experiments conducted at the Ven Te Chow Hydrosystems Laboratory of the University of Illinois at Urbana-Champaign on meltwater meandering channels. A rivulet is carved into an ice block and water is allowed to flow at a constant discharge. Planform evolution is analyzed with time lapse imaging and complemented with rubber molds of the channel once the experiment is over. These molds give us the full 3D structure of the meandering, including incisional overhang. Vertical incision rates are measured throughout the run by taking elevations along the channel, and these measurements are complemented with analysis from the molds. We show examples of meandering of intense amplitude with deep overhangs. Features resembling scroll bars document cyclically punctuated melting. We report on lateral migration rates, incision rates, sinuosity, channel depths, channel widths, reach averaged velocities, bend wavelengths and amplitudes and compare them to values reported in the literature for alluvial rivers.

Uncertainty analysis for hot channel

International Nuclear Information System (INIS)

Panka, I.; Kereszturi, A.

2006-01-01

The fulfillment of the safety analysis acceptance criteria is usually evaluated by separate hot channel calculations using the results of neutronic or/and thermo hydraulic system calculations. In case of an ATWS event (inadvertent withdrawal of control assembly), according to the analysis, a number of fuel rods are experiencing DNB for a longer time and must be regarded as failed. Their number must be determined for a further evaluation of the radiological consequences. In the deterministic approach, the global power history must be multiplied by different hot channel factors (kx) taking into account the radial power peaking factors for each fuel pin. If DNB occurs it is necessary to perform a few number of hot channel calculations to determine the limiting kx leading just to DNB and fuel failure (the conservative DNBR limit is 1.33). Knowing the pin power distribution from the core design calculation, the number of failed fuel pins can be calculated. The above procedure can be performed by conservative assumptions (e.g. conservative input parameters in the hot channel calculations), as well. In case of hot channel uncertainty analysis, the relevant input parameters (k x, mass flow, inlet temperature of the coolant, pin average burnup, initial gap size, selection of power history influencing the gap conductance value) of hot channel calculations and the DNBR limit are varied considering the respective uncertainties. An uncertainty analysis methodology was elaborated combining the response surface method with the one sided tolerance limit method of Wilks. The results of deterministic and uncertainty hot channel calculations are compared regarding to the number of failed fuel rods, max. temperature of the clad surface and max. temperature of the fuel (Authors)

Achromatic Cooling Channel with Li Lenses

Energy Technology Data Exchange (ETDEWEB)

Balbekov, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2002-04-29

A linear cooling channel with Li lenses, solenoids, and 201 MHz RF cavities is considered. A special lattice design is used to minimize chromatic aberrations by suppression of several betatron resonances. Transverse emittance of muon beam decreases from 2 mm to 0.5 mm at the channel of about 110 m length. Longitudinal heating is modest, therefore transmission of the channel is rather high: 96% without decay and 90% with decay. Minimal beam emittance achievable by similar channel estimated as about 0.25 mm at surface field of Li lenses 10 T.

Channeling ion implantation through palladium films

International Nuclear Information System (INIS)

Ishiwara, H.; Furukawa, S.

1975-01-01

The possibility of channeling ion implantation into semiconductors through polycrystalline metallic layers is studied. Minimum values and standard deviations of channeling angular yield in polycrystalline Pd 2 Si layers formed on Si have been measured by protons and 4 He, and 14 N ion backscattering and channeling measurements. Depth distributions of the spread of crystallite orientations and scattering centers such as lattice defects have been separately derived by using the above two quantities. It has been concluded that the channeling-ion-implantation technique will become a practical one by using the parallel scanning system

Indoor MIMO Channel Measurement and Modeling

DEFF Research Database (Denmark)

Nielsen, Jesper Ødum; Andersen, Jørgen Bach

2005-01-01

Forming accurate models of the multiple input multiple output (MIMO) channel is essential both for simulation as well as understanding of the basic properties of the channel. This paper investigates different known models using measurements obtained with a 16x32 MIMO channel sounder for the 5.8GHz...... band. The measurements were carried out in various indoor scenarios including both temporal and spatial aspects of channel changes. The models considered include the so-called Kronecker model, a model proposed by Weichselberger et. al., and a model involving the full covariance matrix, the most...

Operator-sum representation for bosonic Gaussian channels

International Nuclear Information System (INIS)

Ivan, J. Solomon; Sabapathy, Krishna Kumar; Simon, R.

2011-01-01

Operator-sum or Kraus representations for single-mode bosonic Gaussian channels are developed, and several of their consequences explored. The fact that the two-mode metaplectic operators acting as unitary purification of these channels do not, in their canonical form, mix the position and momentum variables is exploited to present a procedure which applies uniformly to all families in the Holevo classification. In this procedure the Kraus operators of every quantum-limited Gaussian channel can be simply read off from the matrix elements of a corresponding metaplectic operator. Kraus operators are employed to bring out, in the Fock basis, the manner in which the antilinear, unphysical matrix transposition map when accompanied by injection of a threshold classical noise becomes a physical channel, denoted D(κ) in the Holevo classification. The matrix transposition channels D(κ), D(κ -1 ) turn out to be a dual pair in the sense that their Kraus operators are related by the adjoint operation. The amplifier channel with amplification factor κ and the beam-splitter channel with attenuation factor κ -1 turn out to be mutually dual in the same sense. The action of the quantum-limited attenuator and amplifier channels as simply scaling maps on suitable quasiprobabilities in phase space is examined in the Kraus picture. Consideration of cumulants is used to examine the issue of fixed points. The semigroup property of the amplifier and attenuator families leads in both cases to a Zeno-like effect arising as a consequence of interrupted evolution. In the cases of entanglement-breaking channels a description in terms of rank 1 Kraus operators is shown to emerge quite simply. In contradistinction, it is shown that there is not even one finite rank operator in the entire linear span of Kraus operators of the quantum-limited amplifier or attenuator families, an assertion far stronger than the statement that these are not entanglement breaking channels. A characterization of

On luminescence bleaching of tidal channel sediments

DEFF Research Database (Denmark)

Fruergaard, Mikkel; Pejrup, Morten; Murray, Andrew S.

2015-01-01

We investigate the processes responsible for bleaching of the quartz OSL signal from tidal channel sediment. Tidal dynamics are expected to play an important role for complete bleaching of tidal sediments. However, no studies have examined the amount of reworking occurring in tidal channels...... and on tidal flats due to the mixing caused by currents and waves. We apply bed level data to evaluate the amount of vertical sediment reworking in modern tidal channels and at a tidal flat. Cycles of deposition and erosion are measured with a bed level sensor, and the results show that gross sedimentation...... was several times higher than net sedimentation. We propose that tidal channel sediment is bleached either on the tidal flat before it is transported to the tidal channels and incorporated in channel-fill successions or, alternatively, on the shallow intertidal part of the channel banks. Based...

ASIC3 channels in multimodal sensory perception.

Science.gov (United States)

Li, Wei-Guang; Xu, Tian-Le

2011-01-19

Acid-sensing ion channels (ASICs), which are members of the sodium-selective cation channels belonging to the epithelial sodium channel/degenerin (ENaC/DEG) family, act as membrane-bound receptors for extracellular protons as well as nonproton ligands. At least five ASIC subunits have been identified in mammalian neurons, which form both homotrimeric and heterotrimeric channels. The highly proton sensitive ASIC3 channels are predominantly distributed in peripheral sensory neurons, correlating with their roles in multimodal sensory perception, including nociception, mechanosensation, and chemosensation. Different from other ASIC subunit composing ion channels, ASIC3 channels can mediate a sustained window current in response to mild extracellular acidosis (pH 7.3-6.7), which often occurs accompanied by many sensory stimuli. Furthermore, recent evidence indicates that the sustained component of ASIC3 currents can be enhanced by nonproton ligands including the endogenous metabolite agmatine. In this review, we first summarize the growing body of evidence for the involvement of ASIC3 channels in multimodal sensory perception and then discuss the potential mechanisms underlying ASIC3 activation and mediation of sensory perception, with a special emphasis on its role in nociception. We conclude that ASIC3 activation and modulation by diverse sensory stimuli represent a new avenue for understanding the role of ASIC3 channels in sensory perception. Furthermore, the emerging implications of ASIC3 channels in multiple sensory dysfunctions including nociception allow the development of new pharmacotherapy.

On the capacity of multiple access and broadcast fading channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2014-01-01

We study the throughput capacity region of the Gaussian multi-access (MAC) fading channel with perfect channel state information (CSI) at the receiver and at the transmitters, at low power regime. We show that it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points.More specifically, we show that at low power regime, the boundary surface of the capacity region shrinks to a single point corresponding to the sum rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Inspired from this result, we propose an on-off scheme, compute its achievable rate, and show that this scheme achieves single user capacity bounds of the MAC channel for a wide class of fading channels at asymptotically low power regime. We argue that this class of fading encompasses all known wireless channels for which the capacity region of the MAC channel has even a simpler expression in terms of users\\' average power constraints only. Using the duality of Gaussian MAC and broadcast channels (BC), we deduce a simple characterization of the BC capacity region at low power regime and show that for a class of fading channels (including Rayleigh fading), time-sharing is asymptotically optimal. © 2014 IEEE.

47 CFR 95.29 - Channels available.

Science.gov (United States)

2010-10-01

... with no more than 5 watts ERP. (g) Fixed stations in GMRS systems authorized before March 18, 1968... transmission of another GMRS station on a different channel or channels), the licensee of the GMRS system must... GMRS system from the following 462 MHz channels: 462.5500, 462.5750, 462.6000, 462.6250, 462.6500, 462...

Study of condensation of refrigerants in a micro-channel for development of future compact micro-channel condensers

Science.gov (United States)

Chowdhury, Sourav

2009-12-01

Mini- and micro-channel technology has gained considerable ground in the recent years in industry and is favored due to its several advantages stemming from its high surface to volume ratio and high values of proof pressure it can withstand. Micro-channel technology has paved the way to development of highly compact heat exchangers with low cost and mass penalties. In the present work, the issues related to the sizing of compact micro-channel condensers have been explored. The considered designs encompass both the conventional and MEMS fabrication techniques. In case of MEMS-fabricated micro-channel condenser, wet etching of the micro-channel structures, followed by bonding of two such wafers with silicon nitride layers at the interface was attempted. It was concluded that the silicon nitride bonding requires great care in terms of high degree of surface flatness and absence of roughness and also high degree of surface purity and thus cannot be recommended for mass fabrication. Following this investigation, a carefully prepared experimental setup and test micro-channel with hydraulic diameter 700 mum and aspect ratio 7:1 was fabricated and overall heat transfer and pressure drop aspects of two condensing refrigerants, R134a and R245fa were studied at a variety of test conditions. To the best of author's knowledge, so far no data has been reported in the literature on condensation in such high aspect ratio micro-channels. Most of the published experimental works on condensation of refrigerants are concerning conventional hydraulic diameter channels (> 3mm) and only recently some experimental data has been reported in the sub-millimeter scale channels for which the surface tension and viscosity effects play a dominant role and the effect of gravity is diminished. It is found that both experimental data and empirically-derived correlations tend to under-predict the present data by an average of 25%. The reason for this deviation could be because a high aspect ratio

Quantum-capacity-approaching codes for the detected-jump channel

International Nuclear Information System (INIS)

Grassl, Markus; Wei Zhaohui; Ji Zhengfeng; Zeng Bei

2010-01-01

The quantum-channel capacity gives the ultimate limit for the rate at which quantum data can be reliably transmitted through a noisy quantum channel. Degradable quantum channels are among the few channels whose quantum capacities are known. Given the quantum capacity of a degradable channel, it remains challenging to find a practical coding scheme which approaches capacity. Here we discuss code designs for the detected-jump channel, a degradable channel with practical relevance describing the physics of spontaneous decay of atoms with detected photon emission. We show that this channel can be used to simulate a binary classical channel with both erasures and bit flips. The capacity of the simulated classical channel gives a lower bound on the quantum capacity of the detected-jump channel. When the jump probability is small, it almost equals the quantum capacity. Hence using a classical capacity-approaching code for the simulated classical channel yields a quantum code which approaches the quantum capacity of the detected-jump channel.

CFD analyses of coolant channel flowfields

Science.gov (United States)

Yagley, Jennifer A.; Feng, Jinzhang; Merkle, Charles L.

1993-01-01

The flowfield characteristics in rocket engine coolant channels are analyzed by means of a numerical model. The channels are characterized by large length to diameter ratios, high Reynolds numbers, and asymmetrical heating. At representative flow conditions, the channel length is approximately twice the hydraulic entrance length so that fully developed conditions would be reached for a constant property fluid. For the supercritical hydrogen that is used as the coolant, the strong property variations create significant secondary flows in the cross-plane which have a major influence on the flow and the resulting heat transfer. Comparison of constant and variable property solutions show substantial differences. In addition, the property variations prevent fully developed flow. The density variation accelerates the fluid in the channels increasing the pressure drop without an accompanying increase in heat flux. Analyses of the inlet configuration suggest that side entry from a manifold can affect the development of the velocity profile because of vortices generated as the flow enters the channel. Current work is focused on studying the effects of channel bifurcation on the flow field and the heat transfer characteristics.

Hydrodynamic optical-field-ionized plasma channels

Science.gov (United States)

Shalloo, R. J.; Arran, C.; Corner, L.; Holloway, J.; Jonnerby, J.; Walczak, R.; Milchberg, H. M.; Hooker, S. M.

2018-05-01

We present experiments and numerical simulations which demonstrate that fully ionized, low-density plasma channels could be formed by hydrodynamic expansion of plasma columns produced by optical field ionization. Simulations of the hydrodynamic expansion of plasma columns formed in hydrogen by an axicon lens show the generation of 200 mm long plasma channels with axial densities of order ne(0 ) =1 ×1017cm-3 and lowest-order modes of spot size WM≈40 μ m . These simulations show that the laser energy required to generate the channels is modest: of order 1 mJ per centimeter of channel. The simulations are confirmed by experiments with a spherical lens which show the formation of short plasma channels with 1.5 ×1017cm-3≲ne(0 ) ≲1 ×1018cm-3 and 61 μ m ≳WM≳33 μ m . Low-density plasma channels of this type would appear to be well suited as multi-GeV laser-plasma accelerator stages capable of long-term operation at high pulse repetition rates.

Relativistic electron-beam transport in curved channels

International Nuclear Information System (INIS)

Vittitoe, C.N.; Morel, J.E.; Wright, T.P.

1982-01-01

Collisionless single particle trajectories are modeled for a single plasma channel having one section curved in a circular arc. The magnetic field is developed by superposition of straight and curved channel segments. The plasma density gives charge and beam-current neutralization. High transport efficiencies are found for turning a relativistic electron beam 90 0 under reasonable conditions of plasma current, beam energy, arc radius, channel radius, and injection distributions in velocity and in position at the channel entrance. Channel exit distributions in velocity and position are found consistent with those for a straight plasma channel of equivalent length. Such transport problems are important in any charged particle-beam application constrained by large diode-to-target distance or by requirements of maximum power deposition in a confined area

Comparison between the effects of positive noncatastrophic HMB ESD stress in n-channel and p-channel power MOSFET's

Science.gov (United States)

Zupac, Dragan; Kosier, Steven L.; Schrimpf, Ronald D.; Galloway, Kenneth F.; Baum, Keith W.

1991-10-01

The effect of noncatastrophic positive human body model (HBM) electrostatic discharge (ESD) stress on n-channel power MOSFETs is radically different from that on p-channel MOSFETs. In n-channel transistors, the stress causes negative shifts of the current-voltage characteristics indicative of positive charge trapping in the gate oxide. In p-channel transistors, the stress increases the drain-to-source leakage current, probably due to localized avalanche electron injection from the p-doped drain.

Tracking channel bed resiliency in forested mountain catchments using high temporal resolution channel bed movement

Science.gov (United States)

Martin, Sarah E.; Conklin, Martha H.

2018-01-01

This study uses continuous-recording load cell pressure sensors in four, high-elevation (1500-1800 m), Sierra Nevada headwater streams to collect high-temporal-resolution, bedload-movement data for investigating the channel bed movement patterns within these streams for water years 2012-2014. Data show an annual pattern where channel bed material in the thalweg starts to build up in early fall, peaks around peak snow melt, and scours back to baseline levels during hydrograph drawdown and base flow. This pattern is punctuated by disturbance and recovery of channel bed material associated with short-term storm events. A conceptual model, linking sediment sources at the channel margins to patterns of channel bed fill and scour in the thalweg, is proposed building on the results of Martin et al. (2014). The material in the thalweg represents a balance between sediment supply from the channel margins and sporadic, conveyor-belt-like downstream transport in the thalweg. The conceptual model highlights not only the importance of production and transport rates but also that seasonal connectedness between the margins and thalweg is a key sediment control, determining the accumulation rate of sediment stores at the margins and the redistribution of sediment from margins to thalweg that feeds the conveyor belt. Disturbance and recovery cycles are observed at multiple temporal scales; but long term, the channel beds are stable, suggesting that the beds act as short-term storage for sediment but are in equilibrium interannually. The feasibility of use for these sensors in forested mountain stream environments is tested. Despite a high failure rate (50%), load cell pressure sensors show potential for high-temporal-resolution bedload measurements, allowing for the collection of channel bed movement data to move beyond time-integrated change measurements - where many of the subtleties of bedload movement patterns may be missed - to continuous and/or real-time measurements. This

From membrane tension to channel gating: A principal energy transfer mechanism for mechanosensitive channels.

Science.gov (United States)

Zhang, Xuejun C; Liu, Zhenfeng; Li, Jie

2016-11-01

Mechanosensitive (MS) channels are evolutionarily conserved membrane proteins that play essential roles in multiple cellular processes, including sensing mechanical forces and regulating osmotic pressure. Bacterial MscL and MscS are two prototypes of MS channels. Numerous structural studies, in combination with biochemical and cellular data, provide valuable insights into the mechanism of energy transfer from membrane tension to gating of the channel. We discuss these data in a unified two-state model of thermodynamics. In addition, we propose a lipid diffusion-mediated mechanism to explain the adaptation phenomenon of MscS. © 2016 The Protein Society.

Language Planning, Channel Management, and ESP.

Science.gov (United States)

Kennedy, Chris

Channel management, a concept developed in marketing to refer to the process by which a product is moved from production to consumption, uses a channel of distribution operating at several levels, each responsible for one or more of the activities of moving the product forward to the consumer. The function of channel management is to select the…

Controlled beta-quench treatment of fuel channels

International Nuclear Information System (INIS)

Moeckel, Andreas; Cremer, Ingo; Kratzer, Anton; Walter, Dirk; Perkins, Richard A.

2007-01-01

The trend towards higher fuel assembly discharge burnups poses new challenges for fuel channels in terms of their dimensional behavior and corrosion resistance. Beta-quenching of fuel channels has been applied by the nuclear industry to improve the dimensional stability of this component. This led AREVA NP to develop a new technique for beta quenching of fuel channels that combines the effect of beta-quenching with the optimization of the microstructure in order to improve the dimensional behavior of fuel channels by randomizing the crystallographic texture, while maintaining the excellent corrosion behavior of the fuel channels by providing intermetallic phase particles of optimum average size. The first fuel channels with these optimized material properties have been placed in the core of a German boiling water reactor (BWR) nuclear power plant in spring of 2004. Some more channels will follow in 2007 to broaden in-pile experience and to receive irradiation feedback from two other nuclear power plants. (authors)

Assesment of strength and integrity of fuel channels

International Nuclear Information System (INIS)

2000-01-01

Detailed analysis to base strength and integrity of fuel channels was necessary for the licensing process. Description of tasks performed in this direction in 1999 is presented: fuel channel independent strength calculations, assessment of present fuel channels state, analysis of dynamic processes during partial group distribution header rupture, structural integrity analysis of fuel channels located next to broke channel

MITOCHONDRIAL BKCa CHANNEL

Directory of Open Access Journals (Sweden)

Enrique eBalderas

2015-03-01

Full Text Available Since its discovery in a glioma cell line 15 years ago, mitochondrial BKCa channel (mitoBKCa has been studied in brain cells and cardiomyocytes sharing general biophysical properties such as high K+ conductance (~300 pS, voltage-dependency and Ca2+-sensitivity. Main advances in deciphering the molecular composition of mitoBKCa have included establishing that it is encoded by the Kcnma1 gene, that a C-terminal splice insert confers mitoBKCa ability to be targeted to cardiac mitochondria, and evidence for its potential coassembly with β subunits. Notoriously, β1 subunit directly interacts with cytochrome c oxidase and mitoBKCa can be modulated by substrates of the respiratory chain. mitoBKCa channel has a central role in protecting the heart from ischemia, where pharmacological activation of the channel impacts the generation of reactive oxygen species and mitochondrial Ca2+ preventing cell death likely by impeding uncontrolled opening of the mitochondrial transition pore. Supporting this view, inhibition of mitoBKCa with Iberiotoxin, enhances cytochrome c release from glioma mitochondria. Many tantalizing questions remain. Some of them are: how is mitoBKCa coupled to the respiratory chain? Does mitoBKCa play non-conduction roles in mitochondria physiology? Which are the functional partners of mitoBKCa? What are the roles of mitoBKCa in other cell types? Answers to these questions are essential to define the impact of mitoBKCa channel in mitochondria biology and disease.

Channel Responses and Hydromodification in Southern California

Science.gov (United States)

Hawley, R. J.; Dust, D. W.; Bledsoe, B. P.

2007-12-01

Hydromodification (changes in watershed hydrologic characteristics, and the resulting hydraulics and channel forms due to urbanization) is ubiquitous in Southern California. In this region, the effects of hydromodification are driven and compounded by the arid/semiarid climate, high relief, erodible soils, high urbanization rates, and relatively low frequency of retention/detention. We conducted a preliminary survey of over 50 stream reaches along a gradient from least disturbed to fully urbanized. All stages of the Channel Evolution Model (CEM) of Schumm et al. (1984) were observed, from stable to degrading, widening, aggrading, and quasi-equilibrium channels. Several sites have CEM stages II through V in close proximity due to headcutting, hardpoints, and infrastructure. We also observed channels in undeveloped watersheds impacted by downstream urbanization via headcutting. A range of intervention measures was observed, with the frequent evolutionary endpoint as a concrete engineered flood control channel. We also observed multiple channel evolution sequences that deviate from the CEM for single-thread, incising channels. An alternative channel response, particularly on smaller urbanized streams is a stabilized, vegetation encroached low-flow channel with regular baseflow supplied by residential irrigation runoff. The limited cases of unimpacted streams that remain tend to be high gradient, high energy systems that are naturally proximate to the transition between braided and meandering form for a given sediment size.

Reliability Improved Design for a Safety System Channel

Energy Technology Data Exchange (ETDEWEB)

Oh, Eung Se; Kim, Yun Goo [KHNP, Daejeon (Korea, Republic of)

2016-05-15

Nowadays, these systems are implemented with a same platform type, such as a qualified programmable logic controller (PLC). The platform intensively uses digital communication with fiber-optic links to reduce cabling costs and to achieve effective signal isolation. These communication interface and redundancies within a channel increase the complexness of an overall system design. This paper proposes a simpler channel architecture design to reduce the complexity and to enhance overall channel reliability. Simplified safety channel configuration is proposed and the failure probabilities are compared with baseline safety channel configuration using an estimated generic value. The simplified channel configuration achieves 40 percent failure reduction compare to baseline safety channel configuration. If this configuration can be implemented within a processor module, overall safety channel reliability is increase and costs of fabrication and maintenance will be greatly reduced.

Reliability Improved Design for a Safety System Channel

International Nuclear Information System (INIS)

Oh, Eung Se; Kim, Yun Goo

2016-01-01

Nowadays, these systems are implemented with a same platform type, such as a qualified programmable logic controller (PLC). The platform intensively uses digital communication with fiber-optic links to reduce cabling costs and to achieve effective signal isolation. These communication interface and redundancies within a channel increase the complexness of an overall system design. This paper proposes a simpler channel architecture design to reduce the complexity and to enhance overall channel reliability. Simplified safety channel configuration is proposed and the failure probabilities are compared with baseline safety channel configuration using an estimated generic value. The simplified channel configuration achieves 40 percent failure reduction compare to baseline safety channel configuration. If this configuration can be implemented within a processor module, overall safety channel reliability is increase and costs of fabrication and maintenance will be greatly reduced

LDPC Code Design for Nonuniform Power-Line Channels

Directory of Open Access Journals (Sweden)

Sanaei Ali

2007-01-01

Full Text Available We investigate low-density parity-check code design for discrete multitone channels over power lines. Discrete multitone channels are well modeled as nonuniform channels, that is, different bits experience various channel parameters. We propose a coding system for discrete multitone channels that allows for using a single code over a nonuniform channel. The number of code parameters for the proposed system is much greater than the number of code parameters in conventional channel. Therefore, search-based optimization methods are impractical. We first formulate the problem of optimizing the rate of an irregular low-density parity-check code, with guaranteed convergence over a general nonuniform channel, as an iterative linear programming which is significantly more efficient than search-based methods. Then we use this technique for a typical power-line channel. The methodology of this paper is directly applicable to all decoding algorithms for which a density evolution analysis is possible.

The effect of search channel elimination on purchase incidence, order size and channel choice

NARCIS (Netherlands)

Konus, U.; Neslin, S.A.; Verhoef, P.C.

This study investigates the impact of eliminating a search channel on purchase incidence, order size, channel choice and, ultimately, sales and profits. We analyze customer panel data from a large retailer over a five-year period. The retailer conducted a randomized field test in which the firm

77 FR 14321 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

Science.gov (United States)

2012-03-09

... via VHF radio on channel 16, to request authorization. If authorization to enter, transit through... Order 13563 emphasizes the importance of quantifying both costs and benefits, of reducing costs, of... Tribes, on the relationship between the Federal Government and Indian Tribes, or on the distribution of...

77 FR 37810 - Special Local Regulations; ODBA Draggin' on the Waccamaw, Atlantic Intracoastal Waterway...

Science.gov (United States)

2012-06-25

... telephone at (843) 740-7050, or a designated representative via VHF radio on channel 16 to seek... Order 13563 emphasizes the importance of quantifying both costs and benefits, of reducing costs, of... Government and Indian Tribes, or on the distribution of power and responsibilities between the Federal...

Fuel channel refilling

International Nuclear Information System (INIS)

Shoukri, M.; Abdul-Razzak, A.

1990-04-01

Analysis of existing data on fuel channel refilling is presented. The analysis focuses on the data obtained using the Stern Laboratories Cold Water Injection Test (CWIT) Facility. The two-fluid model thermal-hydraulics computer code CATHENA is also used to simulate experimental results on fuel channel refilling from both the CWIT and RD-14 facilities. Conclusions related to single and double break tests, including the effect of non-condensible gases, are presented. A set of recommendations is given for further analysis and separate effect experiments. (67 figs., 5 tabs., 24 refs.)

Voltage-gated lipid ion channels

DEFF Research Database (Denmark)

Blicher, Andreas; Heimburg, Thomas Rainer

2013-01-01

Synthetic lipid membranes can display channel-like ion conduction events even in the absence of proteins. We show here that these events are voltage-gated with a quadratic voltage dependence as expected from electrostatic theory of capacitors. To this end, we recorded channel traces and current...... histograms in patch-experiments on lipid membranes. We derived a theoretical current-voltage relationship for pores in lipid membranes that describes the experimental data very well when assuming an asymmetric membrane. We determined the equilibrium constant between closed and open state and the open...... probability as a function of voltage. The voltage-dependence of the lipid pores is found comparable to that of protein channels. Lifetime distributions of open and closed events indicate that the channel open distribution does not follow exponential statistics but rather power law behavior for long open times...

FMCG companies specific distribution channels

Directory of Open Access Journals (Sweden)

Ioana Barin

2009-12-01

Full Text Available Distribution includes all activities undertaken by the producer, alone or in cooperation, since the end of the final finished products or services until they are in possession of consumers. The distribution consists of the following major components: distribution channels or marketing channels, which together form a distribution network; logistics o rphysical distribution. In order to effective achieve, distribution of goods requires an amount of activities and operational processes related to transit of goods from producer to consumer, the best conditions, using existing distribution channels and logistics system. One of the essential functions of a distribution is performing acts of sale, through which, with the actual movement of goods, their change of ownership takes place, that the successive transfer of ownership from producer to consumer. This is an itinerary in the economic cycle of goods, called the distribution channel.

Pricing Decisions of Competing Tobacco Enterprises with Online Channel

Directory of Open Access Journals (Sweden)

Rong Zhang

2015-01-01

Full Text Available According to the new measurement of launching online distribution channels of tobacco enterprises in China, this paper investigates the tobacco firm’s pricing decisions on the supply chain which consists of two manufacturers and one retailer under three dual-channel structures. Three dual-channel structures include no online channel, only one online channel by one manufacture, and two online channels by two manufacturers. We apply the Stackelberg game to analyze the equilibrium pricing strategies under different structures and try to explore the necessity and advantages of launching online sales channels. The results demonstrate that the substitutability of a product has significant impact on introducing online sales channels, and the online dual-channel structure could result in less profit for manufacturers compared to the traditional retail channel structure; and thus, a dual-channel structure with online sales is not the best strategy for traditional manufacturers. Moreover, when the product is less substitutable, the effect of the tobacco control on the online sales channel is inferior to the traditional channels and vice versa.

Separation of Particles in Channels Rotary Engine

Directory of Open Access Journals (Sweden)

Zyatikov Pavel

2015-01-01

Full Text Available The article considers the separation of particles in channels with different relative length. It is shown that the intensity of turbulence at the inlet section of the channel varies considerably in its length. The dependence of the turbulence damping along the channel expressing by fraction of the distance is shown. The ratio of the particle separation efficiency out the gas flow in the rotor channel is defined. The values of particle separation efficiency in the channel for the angle α=π/4 in turbulent aerosol flow is shows, including without mixing the particles.

Channel uranium-graphite reactor mounting

International Nuclear Information System (INIS)

Polushkin, K.K.; Kuznetsov, A.G.; Zheleznyakov, B.N.

1981-01-01

According to theoretical principles of general engineering technology the engineering experience of construction-mounting works at the NPP with channel uranium-graphite reactors is systematized. Main parameters and structural features of the 1000 MW channel uranium-graphite reactors are considered. The succession of mounting operations, premounting equipment and pipelines preparation and mounting works technique are described. The most efficient methods of fitting, welding and machining of reactor elements are recommended. Main problems of technical control service are discussed. A typical netted diagram of main equipment of channel uranium-graphite reactors mounting is given

Omni-channel Retail Information Systems

DEFF Research Database (Denmark)

Tambo, Torben

2014-01-01

key players in the industry of retailing (Wilson, 2012; Verizon, 2012) and covers the idea that anything can be sold anywhere with consistent marketing, reasonable efficiency of the supply chain channels and responsible customer service. This article aims at contributing to a characterisation...... and definition of omni-channel retail information systems (OCRIS) by using the information systems research tradition as a distinctive starting point (Treiblmaier and Strebinger, 2008; Avgerou, 2001; Parboteah et al., 2009). Omni-channel retailing has evolved since 2010 with the ultimate aim of aligning physical...

Skeletal Muscle Na+ Channel Disorders

Directory of Open Access Journals (Sweden)

Dina eSimkin

2011-10-01

Full Text Available Five inherited human disorders affecting skeletal muscle contraction have been traced to mutations in the gene encoding the voltage-gated sodium channel Nav1.4. The main symptoms of these disorders are myotonia or periodic paralysis caused by changes in skeletal muscle fiber excitability. Symptoms of these disorders vary from mild or latent disease to incapacitating or even death in severe cases. As new human sodium channel mutations corresponding to disease states become discovered, the importance of understanding the role of the sodium channel in skeletal muscle function and disease state grows.

Planar Superconducting Millimeter-Wave/Terahertz Channelizing Filter

Science.gov (United States)

Ehsan, Negar; U-yen, Kongpop; Brown, Ari; Hsieh, Wen-Ting; Wollack, Edward; Moseley, Samuel

2013-01-01

This innovation is a compact, superconducting, channelizing bandpass filter on a single-crystal (0.45 m thick) silicon substrate, which operates from 300 to 600 GHz. This device consists of four channels with center frequencies of 310, 380, 460, and 550 GHz, with approximately 50-GHz bandwidth per channel. The filter concept is inspired by the mammalian cochlea, which is a channelizing filter that covers three decades of bandwidth and 3,000 channels in a very small physical space. By using a simplified physical cochlear model, and its electrical analog of a channelizing filter covering multiple octaves bandwidth, a large number of output channels with high inter-channel isolation and high-order upper stopband response can be designed. A channelizing filter is a critical component used in spectrometer instruments that measure the intensity of light at various frequencies. This embodiment was designed for MicroSpec in order to increase the resolution of the instrument (with four channels, the resolution will be increased by a factor of four). MicroSpec is a revolutionary wafer-scale spectrometer that is intended for the SPICA (Space Infrared Telescope for Cosmology and Astrophysics) Mission. In addition to being a vital component of MicroSpec, the channelizing filter itself is a low-resolution spectrometer when integrated with only an antenna at its input, and a detector at each channel s output. During the design process for this filter, the available characteristic impedances, possible lumped element ranges, and fabrication tolerances were identified for design on a very thin silicon substrate. Iterations between full-wave and lumped-element circuit simulations were performed. Each channel s circuit was designed based on the availability of characteristic impedances and lumped element ranges. This design was based on a tabular type bandpass filter with no spurious harmonic response. Extensive electromagnetic modeling for each channel was performed. Four channels

Roughness coefficients for stream channels in Arizona

Science.gov (United States)

Aldridge, B.N.; Garrett, J.M.

1973-01-01

When water flows in an open channel, energy is lost through friction along the banks and bed of the channel and through turbulence within the channel. The amount of energy lost is governed by channel roughness, which is expressed in terms of a roughness coefficient. An evaluation of the roughness coefficient is necessary in many hydraulic computations that involve flow in an open channel. Owing to the lack of satisfactory quantitative procedure, the ability of evaluate roughness coefficients can be developed only through experience; however, a basic knowledge of the methods used to assign the coefficients and the factors affecting them will be a great help. One of the most commonly used equations in open-channel hydraulics is that of Manning. The Manning equation is       1.486

Water Transport and Removal in PEMFC Gas Flow Channel with Various Water Droplet Locations and Channel Surface Wettability

Directory of Open Access Journals (Sweden)

Yanzhou Qin

2018-04-01

Full Text Available Water transport and removal in the proton exchange membrane fuel cell (PEMFC is critically important to fuel cell performance, stability, and durability. Water emerging locations on the membrane-electrode assembly (MEA surface and the channel surface wettability significantly influence the water transport and removal in PEMFC. In most simulations of water transport and removal in the PEMFC flow channel, liquid water is usually introduced at the center of the MEA surface, which is fortuitous, since water droplet can emerge randomly on the MEA surface in PEMFC. In addition, the commonly used no-slip wall boundary condition greatly confines the water sliding features on hydrophobic MEA/channel surfaces, degrading the simulation accuracy. In this study, water droplet is introduced with various locations along the channel width direction on the MEA surface, and water transport and removal is investigated numerically using an improved model incorporating the sliding flow property by using the shear wall boundary condition. It is found that the water droplet can be driven to the channel sidewall by aerodynamics when the initial water location deviates from the MEA center to a certain amount, forming the water corner flow in the flow channel. The channel surface wettability on the water transport is also studied and is shown to have a significant impact on the water corner flow in the flow channel.

A Survey of Channel Modeling for UAV Communications

KAUST Repository

Khuwaja, Aziz Altaf; Chen, Yunfei; Zhao, Nan; Alouini, Mohamed-Slim; Dobbins, Paul

2018-01-01

Unmanned aerial vehicles (UAVs) have gained great interest for rapid deployment in both civil and military applications. UAV communication has its own distinctive channel characteristics compared with widely used cellular and satellite systems. Thus, accurate channel characterization is crucial for the performance optimization and design of efficient UAV communication systems. However, several challenges exist in UAV channel modeling. For example, propagation characteristics of UAV channels are still less explored for spatial and temporal variations in non-stationary channels. Also, airframe shadowing has not yet been investigated for small size rotary UAVs. This paper provides an extensive survey on the measurement campaigns launched for UAV channel modeling using low altitude platforms and discusses various channel characterization efforts. We also review the contemporary perspective of UAV channel modeling approaches and outline some future research challenges in this domain.

A Survey of Channel Modeling for UAV Communications

KAUST Repository

Khuwaja, Aziz Altaf

2018-01-23

Unmanned aerial vehicles (UAVs) have gained great interest for rapid deployment in both civil and military applications. UAV communication has its own distinctive channel characteristics compared with widely used cellular and satellite systems. Thus, accurate channel characterization is crucial for the performance optimization and design of efficient UAV communication systems. However, several challenges exist in UAV channel modeling. For example, propagation characteristics of UAV channels are still less explored for spatial and temporal variations in non-stationary channels. Also, airframe shadowing has not yet been investigated for small size rotary UAVs. This paper provides an extensive survey on the measurement campaigns launched for UAV channel modeling using low altitude platforms and discusses various channel characterization efforts. We also review the contemporary perspective of UAV channel modeling approaches and outline some future research challenges in this domain.

Quantum and Private Capacities of Low-Noise Channels

Science.gov (United States)

Leditzky, Felix; Leung, Debbie; Smith, Graeme

2018-04-01

We determine both the quantum and the private capacities of low-noise quantum channels to leading orders in the channel's distance to the perfect channel. It has been an open problem for more than 20 yr to determine the capacities of some of these low-noise channels such as the depolarizing channel. We also show that both capacities are equal to the single-letter coherent information of the channel, again to leading orders. We thus find that, in the low-noise regime, superadditivity and degenerate codes have a negligible benefit for the quantum capacity, and shielding does not improve the private capacity beyond the quantum capacity, in stark contrast to the situation when noisier channels are considered.

Channel CAT: A Tactical Link Analysis Tool

Science.gov (United States)

1997-09-01

NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS CHANNEL CAT : A TACTICAL LINK ANALYSIS TOOL by Michael Glenn Coleman September 1997 Thesis...REPORT TYPE AND DATES COVERED September 1997 Master’s Thesis 4. TITLE AND SUBTITLE CHANNEL CAT : A TACTICAL LINK ANALYSIS TOOL 5. FUNDING NUMBERS 6...tool, the Channel Capacity Analysis Tool (Channel CAT ), designed to provide an automated tool for the anlysis of design decisions in developing client

77 FR 24433 - Special Local Regulations; ODBA Draggin on the Waccamaw, Atlantic Intracoastal Waterway...

Science.gov (United States)

2012-04-24

... (843) 740-7050, or a designated representative via VHF radio on channel 16. If authorization to enter... Order 13563 emphasizes the importance of quantifying both costs and benefits, of reducing costs, of... government and the States, or on the distribution of power and responsibilities among the various levels of...

78 FR 22193 - Special Local Regulations; West Palm Beach Triathlon Championship, Intracoastal Waterway; West...

Science.gov (United States)

2013-04-15

... Championship. On June 1, 2013, Game One Sports Marketing Group is hosting the West Palm Beach Triathlon... VHF radio on channel 16, to request authorization. If authorization to enter, transit through, anchor... government and the States, or on the distribution of power and responsibilities among the various levels of...

Channeling and dynamic chaos

Energy Technology Data Exchange (ETDEWEB)

Bolotin, IU L; Gonchar, V IU; Truten, V I; Shulga, N F

1986-01-01

It is shown that axial channeling of relativistic electrons can give rise to the effect of dynamic chaos which involves essentially chaotic motion of a particle in the channel. The conditions leading to the effect of dynamic chaos and the manifestations of this effect in physical processes associated with the passage of particles through a crystal are examined using a silicon crystal as an example. 7 references.

Fuel assembly and fuel channel box

International Nuclear Information System (INIS)

Sakuma, Toraki; Hirakawa, Hiromasa; Ishizaki, Hideaki; Nakajima, Junjiro; Aizawa, Yasuhiro.

1992-01-01

A fuel channel box has a square cylindrical shape and, in the transversal cross sectional shape, the wall thickness of a corner portion is greater than that of a central portion of the side wall except for an upper portion thereof. The upper portion of the channel box includes a region to be in contact with an upper lattice plate and a region to attach a channel spacer. Then, the wall thickness of these regions is uniform in the transversal cross section and they have the same wall thickness with that of the corner portion which has the increased wall thickness. With such a constitution, the upper portion of the channel box receives a counter force applied from the upper lattice plate upon occurrence of earthquakes and moderate it to reduce local stresses and deformation. Further, a similar region with increased wall thickness is disposed also to the lower portion of the channel box, thereby enabling to suppress the amount of coolants leaked from a portion between the lower portion and a lower tie plate, and improve the mechanical integrity of the channel box. (I.N.)

A new simple model for composite fading channels: Second order statistics and channel capacity

KAUST Repository

Yilmaz, Ferkan

2010-09-01

In this paper, we introduce the most general composite fading distribution to model the envelope and the power of the received signal in such fading channels as millimeter wave (60 GHz or above) fading channels and free-space optical channels, which we term extended generalized-K (EGK) composite fading distribution. We obtain the second-order statistics of the received signal envelope characterized by the EGK composite fading distribution. Expressions for probability density function, cumulative distribution function, level crossing rate and average fade duration, moments, amount of fading and average capacity are derived. Numerical and computer simulation examples validate the accuracy of the presented mathematical analysis. © 2010 IEEE.

Ion channeling revisited

Energy Technology Data Exchange (ETDEWEB)

Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Corona, Aldo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nguyen, Anh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2014-09-01

A MS Excel program has been written that calculates accidental, or unintentional, ion channeling in cubic bcc, fcc and diamond lattice crystals or polycrystalline materials. This becomes an important issue when simulating the creation by energetic neutrons of point displacement damage and extended defects using beams of ions. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different powers of the argument. The program then offers an extremely convenient way to calculate axial and planar half-angles and minimum yield or dechanneling probabilities, effects on half-angles of amorphous overlayers, accidental channeling probabilities for randomly oriented crystals or crystallites, and finally a way to automatically generate stereographic projections of axial and planar channeling half-angles. The program can generate these projections and calculate these probabilities for axes and [hkl] planes up to (555).

Voltage-gated calcium channels of Paramecium cilia.

Science.gov (United States)

Lodh, Sukanya; Yano, Junji; Valentine, Megan S; Van Houten, Judith L

2016-10-01

Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca 2+ entering the cilium through voltage-gated Ca 2+ (Ca V ) channels that are found exclusively in the cilia. As ciliary Ca 2+ levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the Ca V channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary Ca V channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three Ca V α1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary Ca V channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of Ca V channel activity do not express any of the three Ca V 1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three Ca V channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the Ca V 1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia. © 2016. Published by The Company of Biologists Ltd.

On the domestic fuel channel for BWR

International Nuclear Information System (INIS)

Fukada, Hiroshi

1979-01-01

Kobe Steel Ltd. started the domestic manufacture of fuel channel boxes for BWRs in 1967, and entered the actual production stage four years after that. Since 1976, the mass production system was adopted with the increase of the demand. The requirements about the surface contamination and the dimensional accuracy over whole length are very strict in the fuel channel boxes, moreover, special consideration must be given so as to prevent the deformation in use. The unique working methods such as electron beam welding, high temperature press forming and so on are employed in Kobe Steel Ltd. to satisfy such strict requirements, therefore the quality of the produced fuel channel boxes is superior to imported ones. At present, the fuel channel boxes domestically made by Kobe Steel Ltd. are used for almost all BWRs in Japan. The functions of fuel channel boxes are to flow boiling coolant uniformly upward, to guide control rods, and to increase the rigidity of fuel assembly. The fuel channel boxes are the square tubes of zircaloy 4 of 134.06 mm inside width, 2.03 mm thickness, and 4118 or 4239 mm length. The progress of the development and the features of the fuel channel boxes and the manufacturing processes are described. Zircaloy plates are formed into channels, and two channels are electron beam-welded after the edge preparation, to make a box. Ultrasonic examination and stress relief treatment are applied, and clips and spacers are welded. (Kako, I.)

Almost all quantum channels are equidistant

Science.gov (United States)

Nechita, Ion; Puchała, Zbigniew; Pawela, Łukasz; Życzkowski, Karol

2018-05-01

In this work, we analyze properties of generic quantum channels in the case of large system size. We use random matrix theory and free probability to show that the distance between two independent random channels converges to a constant value as the dimension of the system grows larger. As a measure of the distance we use the diamond norm. In the case of a flat Hilbert-Schmidt distribution on quantum channels, we obtain that the distance converges to 1/2 +2/π , giving also an estimate for the maximum success probability for distinguishing the channels. We also consider the problem of distinguishing two random unitary rotations.

Optimal processing of reversible quantum channels

Energy Technology Data Exchange (ETDEWEB)

Bisio, Alessandro, E-mail: alessandro.bisio@unipv.it [QUIT Group, Dipartimento di Fisica, INFN Sezione di Pavia, via Bassi 6, 27100 Pavia (Italy); D' Ariano, Giacomo Mauro; Perinotti, Paolo [QUIT Group, Dipartimento di Fisica, INFN Sezione di Pavia, via Bassi 6, 27100 Pavia (Italy); Sedlák, Michal [Department of Optics, Palacký University, 17. Listopadu 1192/12, CZ-771 46 Olomouc (Czech Republic); Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava (Slovakia)

2014-05-01

We consider the general problem of the optimal transformation of N uses of (possibly different) unitary channels to a single use of another unitary channel in any finite dimension. We show how the optimal transformation can be fully parallelized, consisting in a preprocessing channel followed by a parallel action of all the N unitaries and a final postprocessing channel. Our techniques allow to achieve an exponential reduction in the number of the free parameters of the optimization problem making it amenable to an efficient numerical treatment. Finally, we apply our general results to find the analytical solution for special cases of interest like the cloning of qubit phase gates.

Pore size matters for potassium channel conductance

Science.gov (United States)

Moldenhauer, Hans; Pincuntureo, Matías

2016-01-01

Ion channels are membrane proteins that mediate efficient ion transport across the hydrophobic core of cell membranes, an unlikely process in their absence. K+ channels discriminate K+ over cations with similar radii with extraordinary selectivity and display a wide diversity of ion transport rates, covering differences of two orders of magnitude in unitary conductance. The pore domains of large- and small-conductance K+ channels share a general architectural design comprising a conserved narrow selectivity filter, which forms intimate interactions with permeant ions, flanked by two wider vestibules toward the internal and external openings. In large-conductance K+ channels, the inner vestibule is wide, whereas in small-conductance channels it is narrow. Here we raise the idea that the physical dimensions of the hydrophobic internal vestibule limit ion transport in K+ channels, accounting for their diversity in unitary conductance. PMID:27619418

Cryogenic microwave channelized receiver

International Nuclear Information System (INIS)

Rauscher, C.; Pond, J.M.; Tait, G.B.

1996-01-01

The channelized receiver being presented demonstrates the use of high temperature superconductor technology in a microwave system setting where superconductor, microwave-monolithic-integrated-circuit, and hybrid-integrated-circuit components are united in one package and cooled to liquid-nitrogen temperatures. The receiver consists of a superconducting X-band four-channel demultiplexer with 100-MHz-wide channels, four commercial monolithically integrated mixers, and four custom-designed hybrid-circuit detectors containing heterostructure ramp diodes. The composite receiver unit has been integrated into the payload of the second-phase NRL high temperature superconductor space experiment (HTSSE-II). Prior to payload assembly, the response characteristics of the receiver were measured as functions of frequency, temperature, and drive levels. The article describes the circuitry, discusses the key issues related to design and implementation, and summarizes the experimental results

Optimal super dense coding over memory channels

OpenAIRE

Shadman, Zahra; Kampermann, Hermann; Macchiavello, Chiara; Bruß, Dagmar

2011-01-01

We study the super dense coding capacity in the presence of quantum channels with correlated noise. We investigate both the cases of unitary and non-unitary encoding. Pauli channels for arbitrary dimensions are treated explicitly. The super dense coding capacity for some special channels and resource states is derived for unitary encoding. We also provide an example of a memory channel where non-unitary encoding leads to an improvement in the super dense coding capacity.

Open-channel effects on heavy-quarkonium spectra: a phenomenological study within a one-open-channel approximation

International Nuclear Information System (INIS)

Matsuda, Y.; Kato, K.; Yabusaki, N.; Hirano, M.; Nakanishi, R.; Sakai, M.

1997-01-01

Open-channel effects on charmonium (S- and D-waves) and bottomonium (S-wave) J P = 1 - spectra are investigated within a one-open-channel approximation. Mass shifts and decay widths of these states just above the threshold are obtained by taking into account a coupling between confined quarkonium states and decaying states of the open channel. The final-state interaction (FSI) between the decaying meson and antimeson plays a very important role in producing a reasonable magnitude of coupling; the FSI provides the open-channel poles (R 1 , R 2 ) at the appropriate positions on the complex energy plane. The result is found to be independent of the detailed form of the transition potential and the final-state interaction. (author)

Multiple flow profiles for two-phase flow in single microfluidic channels through site-selective channel coating.

Science.gov (United States)

Logtenberg, Hella; Lopez-Martinez, Maria J; Feringa, Ben L; Browne, Wesley R; Verpoorte, Elisabeth

2011-06-21

An approach to control two-phase flow systems in a poly(dimethylsiloxane) (PDMS) microfluidic device using spatially selective surface modification is demonstrated. Side-by-side flows of ethanol : water solutions containing different polymers are used to selectively modify both sides of a channel by laminar flow patterning. Introduction of air pockets during modification allows for control over the length of the channel section that is modified. This approach makes it possible to achieve slug flow and side-by-side flow of water : 1-octanol simultaneously within the same PDMS channel, without the need of additional structural elements. A key finding is that conditioning of the PDMS channels with 1-octanol before polymer deposition is crucial to achieving stable side-by-side flows.

78 FR 2916 - Special Local Regulation; West Palm Beach Triathlon Championship, Intracoastal Waterway, West...

Science.gov (United States)

2013-01-15

.... Discussion of Proposed Rule On June 1, 2013, Game One Sports Marketing Group is hosting the West Palm Beach... representative via VHF radio on channel 16, to request authorization. If authorization to enter, transit through... between the national government and the States, or on the distribution of power and responsibilities among...

Channel perceptions and usage: beyond media richness factors

NARCIS (Netherlands)

Pieterson, Willem Jan; Teerling, Marije; Ebbers, Wolfgang E.; Wimmer, Maria A.; Scholl, Hans J.; Ferro, Enrico

2008-01-01

In this paper, we asses how service channel perceptions affect channel choice and channel usage. Building on communication theories, such as the Media Richness Theory, we explore how different channel characteristics are perceived by citizens in a Dutch governmental service chain. The results of our

Quantum incompatibility of channels with general outcome operator algebras

Science.gov (United States)

Kuramochi, Yui

2018-04-01

A pair of quantum channels is said to be incompatible if they cannot be realized as marginals of a single channel. This paper addresses the general structure of the incompatibility of completely positive channels with a fixed quantum input space and with general outcome operator algebras. We define a compatibility relation for such channels by identifying the composite outcome space as the maximal (projective) C*-tensor product of outcome algebras. We show theorems that characterize this compatibility relation in terms of the concatenation and conjugation of channels, generalizing the recent result for channels with quantum outcome spaces. These results are applied to the positive operator valued measures (POVMs) by identifying each of them with the corresponding quantum-classical (QC) channel. We also give a characterization of the maximality of a POVM with respect to the post-processing preorder in terms of the conjugate channel of the QC channel. We consider another definition of compatibility of normal channels by identifying the composite outcome space with the normal tensor product of the outcome von Neumann algebras. We prove that for a given normal channel, the class of normally compatible channels is upper bounded by a special class of channels called tensor conjugate channels. We show the inequivalence of the C*- and normal compatibility relations for QC channels, which originates from the possibility and impossibility of copying operations for commutative von Neumann algebras in C*- and normal compatibility relations, respectively.

Secondary Channel Bifurcation Geometry: A Multi-dimensional Problem

Science.gov (United States)

Gaeuman, D.; Stewart, R. L.

2017-12-01

The construction of secondary channels (or side channels) is a popular strategy for increasing aquatic habitat complexity in managed rivers. Such channels, however, frequently experience aggradation that prevents surface water from entering the side channels near their bifurcation points during periods of relatively low discharge. This failure to maintain an uninterrupted surface water connection with the main channel can reduce the habitat value of side channels for fish species that prefer lotic conditions. Various factors have been proposed as potential controls on the fate of side channels, including water surface slope differences between the main and secondary channels, the presence of main channel secondary circulation, transverse bed slopes, and bifurcation angle. A quantitative assessment of more than 50 natural and constructed secondary channels in the Trinity River of northern California indicates that bifurcations can assume a variety of configurations that are formed by different processes and whose longevity is governed by different sets of factors. Moreover, factors such as bifurcation angle and water surface slope vary with discharge level and are continuously distributed in space, such that they must be viewed as a multi-dimensional field rather than a single-valued attribute that can be assigned to a particular bifurcation.

Multi-channel polarized thermal emitter

Science.gov (United States)

Lee, Jae-Hwang; Ho, Kai-Ming; Constant, Kristen P

2013-07-16

A multi-channel polarized thermal emitter (PTE) is presented. The multi-channel PTE can emit polarized thermal radiation without using a polarizer at normal emergence. The multi-channel PTE consists of two layers of metallic gratings on a monolithic and homogeneous metallic plate. It can be fabricated by a low-cost soft lithography technique called two-polymer microtransfer molding. The spectral positions of the mid-infrared (MIR) radiation peaks can be tuned by changing the periodicity of the gratings and the spectral separation between peaks are tuned by changing the mutual angle between the orientations of the two gratings.

Basolateral K+ channels in airway epithelia. II. Role in Cl- secretion and evidence for two types of K+ channel

International Nuclear Information System (INIS)

McCann, J.D.; Welsh, M.J.

1990-01-01

We previously described a Ca2(+)-activated K+ channel (KCLIC) in airway epithelial cells. To determine whether the KCLIC channel is a basolateral membrane channel and to understand its role in Cl- secretion, we studied airway epithelial cells grown on permeable supports. When cells were stimulated with A23187, charybdotoxin (ChTX) inhibited Cl- secretion and 86Rb efflux at the same concentrations, indicating that the KCLIC channel is required for Ca2(+)-stimulated Cl- secretion. We also investigated the function of K+ channels in adenosine 3',5'-cyclic monophosphate-stimulated secretion. Addition of isoproterenol caused a biphasic increase in Cl- secretion; the time course of the transient component correlated with the time course of the isoproterenol-induced increase in Ca2+ concentration [( Ca2+]c). ChTX inhibited the transient component, but not the prolonged component of secretion; Ba2+ inhibited the sustained component. These results suggest that when cells are grown on permeable supports isoproterenol-induced secretion depends on activation of two types of K+ channel: the KCLIC channel that is stimulated initially and a ChTX-insensitive K+ channel that is stimulated during sustained secretion. This conclusion was supported by measurement of 86Rb efflux from cell monolayers

Consideration of hot channel factors in design for providing operating margins on coolant channel outlet temperature

International Nuclear Information System (INIS)

Sharma, V.K.; Surendar, C.; Bapat, C.N.

1994-01-01

The Indian Pressurized Heavy Water Reactors (IPHWR) are horizontal pressure tube reactors using natural uranium oxide fuel in the form of short (495 mm) clusters. The fuel clusters in the Zr-Nb pressure tubes are cooled by high pressure, high temperature and subcooled circulating heavy water. Coolant flow distribution to individual channels is designed to match the power distribution so as to obtain uniform coolant outlet temperature. However, during operation, the coolant outlet temperature in individual channels deviate from their nominal value due to: tolerances in process design; effects of grid frequency on the pump speed; deviation in channel powers from the nominal values due to on-power fuelling and movement of reactivity devices, and so on. Thus an operating margin, between the highest permissible and nominal coolant outlet temperatures, is required taking into account various hot channel factors that contribute to higher coolant outlet temperatures. The paper discusses the methodology adopted to assess various hot channel factors which would provide optimum operating margins while ensuring sub-cooling. (author)

Pricing Decisions of a Dual-Channel Closed-Loop Supply Chain under Uncertain Demand of Indirect Channel

Directory of Open Access Journals (Sweden)

Jie Gao

2016-01-01

Full Text Available The dual-channel closed-loop supply chain (CLSC which is composed of one manufacturer and one retailer under uncertain demand of an indirect channel is constructed. In this paper, we establish three pricing models under decentralized decision making, namely, the Nash game between the manufacturer and the retailer, the manufacturer-Stackelberg game, and the retailer-Stackelberg game, to investigate pricing decisions of the CLSC in which the manufacturer uses the direct channel and indirect channel to sell products and entrusts the retailer to collect the used products. We numerically analyze the impact of customer acceptance of the direct channel (θ on pricing decisions and excepted profits of the CLSC. The results show that when the variable θ changes in a certain range, the wholesale price, retail price, and expected profits of the retailer all decrease when θ increases, while the direct online sales price and manufacturer’s expected profits in the retailer-Stackelberg game all increase when θ increases. However, the optimal recycling transfer price and optimal acquisition price of used product are unaffected by θ.

Authentication over Noisy Channels

OpenAIRE

Lai, Lifeng; Gamal, Hesham El; Poor, H. Vincent

2008-01-01

In this work, message authentication over noisy channels is studied. The model developed in this paper is the authentication theory counterpart of Wyner's wiretap channel model. Two types of opponent attacks, namely impersonation attacks and substitution attacks, are investigated for both single message and multiple message authentication scenarios. For each scenario, information theoretic lower and upper bounds on the opponent's success probability are derived. Remarkably, in both scenarios,...

Study of material properties using channeling radiation

International Nuclear Information System (INIS)

Pantell, R.H.; Kephart, J.O.; Klein, R.K.; Park, H.; Berman, B.L.; Datz, S.

1986-01-01

A possible application for channeling radiation is for investigating the properties of crystals in which the channeling occurs. In this paper we present some general considerations concerning channeling radiation as a measurement technique, and then we proceed to describe several specific examples

Well-Defined Microapertures for Ion Channel Biosensors

NARCIS (Netherlands)

Halza, Erik; Bro, Tobias Hedegaard; Bilenberg, Brian; Kocer, Armagan

2013-01-01

Gated ion channels are excitable nanopores in biological membranes. They sense and respond to different triggers in nature. The sensory characteristics of these channels can be modified by protein engineering tools and the channels can be functionally reconstituted into synthetic lipid bilayer

Quantum channels and their entropic characteristics

International Nuclear Information System (INIS)

Holevo, A S; Giovannetti, V

2012-01-01

One of the major achievements of the recently emerged quantum information theory is the introduction and thorough investigation of the notion of a quantum channel which is a basic building block of any data-transmitting or data-processing system. This development resulted in an elaborated structural theory and was accompanied by the discovery of a whole spectrum of entropic quantities, notably the channel capacities, characterizing information-processing performance of the channels. This paper gives a survey of the main properties of quantum channels and of their entropic characterization, with a variety of examples for finite-dimensional quantum systems. We also touch upon the 'continuous-variables' case, which provides an arena for quantum Gaussian systems. Most of the practical realizations of quantum information processing were implemented in such systems, in particular based on principles of quantum optics. Several important entropic quantities are introduced and used to describe the basic channel capacity formulae. The remarkable role of specific quantum correlations—entanglement—as a novel communication resource is stressed.

HANARO core channel flow-rate measurement

Energy Technology Data Exchange (ETDEWEB)

Kim, Heon Il; Chae, Hee Tae; Im, Don Soon; Kim, Seon Duk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1996-06-01

HANARO core consists of 23 hexagonal flow tubes and 16 cylindrical flow tubes. To get the core flow distribution, we used 6 flow-rate measuring dummy fuel assemblies (instrumented dummy fuel assemblies). The differential pressures were measured and converted to flow-rates using the predetermined relationship between AP and flow-rate for each instrumented dummy fuel assemblies. The flow-rate for the cylindrical flow channels shows +-7% relative errors and that for the hexagonal flow channels shows +-3.5% relative errors. Generally the flow-rates of outer core channels show smaller values compared to those of inner core. The channels near to the core inlet pipe and outlet pipes also show somewhat lower flow-rates. For the lower flow channels, the thermal margin was checked by considering complete linear power histories. From the experimental results, the gap flow-rate was estimated to be 49.4 kg/s (cf. design flow of 50 kg/s). 15 tabs., 9 figs., 10 refs. (Author) .new.

Algebraic Side-Channel Attack on Twofish

Directory of Open Access Journals (Sweden)

Chujiao Ma

2017-05-01

Full Text Available While algebraic side-channel attack (ASCA has been successful in breaking simple cryptographic algorithms, it has never been done on larger or more complex algorithms such as Twofish. Compared to other algorithms that ASCA has been used on, Twofish is more difficult to attack due to the key-dependent S-boxes as well as the complex key scheduling. In this paper, we propose the first algebraic side-channel attack on Twofish, and examine the importance of side-channel information in getting past the key-dependent S-boxes and the complex key scheduling. The cryptographic algorithm and side-channel information are both expressed as boolean equations and a SAT solver is used to recover the key. While algebraic attack by itself is not sufficient to break the algorithm, with the help of side-channel information such as Hamming weights, we are able to correctly solve for 96 bits of the 128 bits key in under 2 hours with known plaintext/ciphertext.

Micro-channel plates and vacuum detectors

Energy Technology Data Exchange (ETDEWEB)

Gys, T., E-mail: Thierry.Gys@cern.ch

2015-07-01

A micro-channel plate is an array of miniature electron multipliers that are each acting as a continuous dynode chain. The compact channel structure results in high spatial and time resolutions and robustness to magnetic fields. Micro-channel plates have been originally developed for night vision applications and integrated as an amplification element in image intensifiers. These devices show single-photon sensitivity with very low noise and have been used as such for scintillating fiber tracker readout in high-energy physics experiments. Given their very short transit time spread, micro-channel plate photomultiplier tubes are also being used in time-of-flight and particle identification detectors. The present paper will cover the history of the micro-channel plate development, basic features, and some of their applications. Emphasis will be put on various new manufacturing processes that have been developed over the last few years, and that result in a significant improvement in terms of efficiency, noise, and lifetime performance.

Subchannel analysis code development for CANDU fuel channel

International Nuclear Information System (INIS)

Park, J. H.; Suk, H. C.; Jun, J. S.; Oh, D. J.; Hwang, D. H.; Yoo, Y. J.

1998-07-01

Since there are several subchannel codes such as COBRA and TORC codes for a PWR fuel channel but not for a CANDU fuel channel in our country, the subchannel analysis code for a CANDU fuel channel was developed for the prediction of flow conditions on the subchannels, for the accurate assessment of the thermal margin, the effect of appendages, and radial/axial power profile of fuel bundles on flow conditions and CHF and so on. In order to develop the subchannel analysis code for a CANDU fuel channel, subchannel analysis methodology and its applicability/pertinence for a fuel channel were reviewed from the CANDU fuel channel point of view. Several thermalhydraulic and numerical models for the subchannel analysis on a CANDU fuel channel were developed. The experimental data of the CANDU fuel channel were collected, analyzed and used for validation of a subchannel analysis code developed in this work. (author). 11 refs., 3 tabs., 50 figs

Simulation of channelled ion ranges in crystalline silicon

International Nuclear Information System (INIS)

Kabadayi, Oender; Guemues, Hasan

2004-01-01

We present results from a channelled ion range simulation model based on separation of ion trajectories into three different categories known as random, channelled, and well-channelled. We present this for boron projectiles incident along the Si direction. Stopping powers for channelled particles, well-channelled, and random particles are determined using experimental ratios of random and channelled stopping powers for a boron/silicon system. We have found the particle range distributions and the mean range of particles in crystalline channels. A new program code has been developed for the implementation of the presented model. The results are compared with experimental data as well as Crystal-transport and range of ions in matter, stopping and ranges of ions in matter, and projected range algorithm programs. We have found good agreement between our calculations and experiment, with an average discrepancy of 7%. Our model is also able to simulate the observed shift towards larger depths for the main ion distribution under channelling conditions

Assessing the Consequences of a Channel Switch

OpenAIRE

Xinlei (Jack) Chen; George John; Om Narasimhan

2008-01-01

Switching marketing channels is an expensive and sticky decision. While a number of theories suggest efficiency and strategic differences between channels, there is virtually no work on combining these ideas into an empirically workable methodology to assess the impact of a channel switch. In this study, we undertake to close this gap with an empirical study of the sports drink market, featuring competing producers and heterogeneous channels. We estimate demand and cost parameters for a numbe...

Degenerate RFID Channel Modeling for Positioning Applications

Directory of Open Access Journals (Sweden)

A. Povalac

2012-12-01

Full Text Available This paper introduces the theory of channel modeling for positioning applications in UHF RFID. It explains basic parameters for channel characterization from both the narrowband and wideband point of view. More details are given about ranging and direction finding. Finally, several positioning scenarios are analyzed with developed channel models. All the described models use a degenerate channel, i.e. combined signal propagation from the transmitter to the tag and from the tag to the receiver.

Subunit Stoichiometry of Human Muscle Chloride Channels

OpenAIRE

Fahlke, Christoph; Knittle, Timothy; Gurnett, Christina A.; Campbell, Kevin P.; George, Alfred L.

1997-01-01

Voltage-gated Cl? channels belonging to the ClC family appear to function as homomultimers, but the number of subunits needed to form a functional channel is controversial. To determine subunit stoichiometry, we constructed dimeric human skeletal muscle Cl? channels in which one subunit was tagged by a mutation (D136G) that causes profound changes in voltage-dependent gating. Sucrose-density gradient centrifugation experiments indicate that both monomeric and dimeric hClC-1 channels in their ...

Reservoir architecture patterns of sandy gravel braided distributary channel

Directory of Open Access Journals (Sweden)

Senlin Yin

2016-06-01

Full Text Available The purpose of this study was to discuss shape, scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel. Lithofacies analysis, hierarchy bounding surface analysis and subsurface dense well pattern combining with outcrops method were used to examine reservoir architecture patterns of sandy gravel braided distributary channel based on cores, well logging, and outcrops data, and the reservoir architecture patterns of sandy gravel braided distributary channels in different grades have been established. The study shows: (1 The main reservoir architecture elements for sandy gravel braided channel delta are distributary channel and overbank sand, while reservoir flow barrier elements are interchannel and lacustrine mudstone. (2 The compound sand bodies in the sandy gravel braided delta distributary channel take on three shapes: sheet-like distributary channel sand body, interweave strip distributary channel sand body, single strip distributary channel sand body. (3 Identification marks of single distributary channel include: elevation of sand body top, lateral overlaying, “thick-thin-thick” feature of sand bodies, interchannel mudstone and overbank sand between distributary channels and the differences in well log curve shape of sand bodies. (4 Nine lithofacies types were distinguished in distributary channel unit interior, different channel units have different lithofacies association sequence.

A Channelization-Based DOA Estimation Method for Wideband Signals

Directory of Open Access Journals (Sweden)

Rui Guo

2016-07-01

Full Text Available In this paper, we propose a novel direction of arrival (DOA estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR using direct wideband radio frequency (RF digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method.

Bywalled plasma formation in vacuum prolonged channels

International Nuclear Information System (INIS)

Korenev, S.A.; Rubin, N.B.

1982-01-01

To produce homogeneous along the channel length plasma the application of incomplete rate-in surface dielectric discharge for generating the bywalled plasma in prolonged cylindrical channels at a pressure of the residual gas of P approximately 10 -5 Torr is proposed. Experimental set-up consisted of a pulse voltage generator and a plasma channel. The plasma channel was a coaxial system of three tubes inserted into each other. The first outer tube is made of a stainless steel, the second - of a dielectric material, the third - of smallsized stainless steel greed. It is demonstrated that the plasma being formed in the process is sufficiently homogeneous by concentration of the components, by the channel length and azimuth. The length of the experimental channel under investigation was 1.6 m, its diameter amounted 0.05 m. The maximum concentration of electron component was 10 17 m -3

Electronic trade effect of marketing channels

OpenAIRE

Lovreta Stipe; Stojković Dragan

2009-01-01

E-commerce has caused many significant changes in marketing channels. Consumers had obtained multiple benefits from e-commerce. In addition, it has increased the level of competition in marketing channels. However, the focus of this paper is multichannel strategy and integration of physical (store) and electronic marketing channels. E-commerce has induced dynamic development of multichannel strategy. This strategy has evolved as a consequence of multichannel consumer orientation. In developed...

Dysfunctional HCN ion channels in neurological diseases

Directory of Open Access Journals (Sweden)

Jacopo C. DiFrancesco

2015-03-01

Full Text Available Hyperpolarization-activated cyclic nucleotide-gated (HCN channels are expressed as four different isoforms (HCN1-4 in the heart and in the central and peripheral nervous systems. HCN channels are activated by membrane hyperpolarization at voltages close to resting membrane potentials and carry the hyperpolarization-activated current, dubbed If (funny current in heart and Ih in neurons. HCN channels contribute in several ways to neuronal activity and are responsible for many important cellular functions, including cellular excitability, generation and modulation of rhythmic activity, dendritic integration, transmission of synaptic potentials and plasticity phenomena. Because of their role, defective HCN channels are natural candidates in the search for potential causes of neurological disorders in humans. Several data, including growing evidence that some forms of epilepsy are associated with HCN mutations, support the notion of an involvement of dysfunctional HCN channels in different experimental models of the disease. Additionally, some anti-epileptic drugs are known to modify the activity of the Ih current. HCN channels are widely expressed in the peripheral nervous system and recent evidence has highlighted the importance of the HCN2 isoform in the transmission of pain. HCN channels are also present in the midbrain system, where they finely regulate the activity of dopaminergic neurons, and a potential role of these channels in the pathogenesis of Parkinson’s disease has recently emerged. The function of HCN channels is regulated by specific accessory proteins, which control the correct expression and modulation of the neuronal Ih current. Alteration of these proteins can severely interfere with the physiological channel function, potentially predisposing to pathological conditions. In this review we address the present knowledge of the association between HCN dysfunctions and neurological diseases, including clinical, genetic and

Choosing channel quantization levels and viterbi decoding for space diversity reception over the additive white Guassian noise channel

Science.gov (United States)

Kalson, S.

1986-01-01

Previous work in the area of choosing channel quantization levels for a additive white Gaussian noise channel composed of one receiver-demodulator is reviewed, and how this applies to the Deep Space Network composed of several receiver-demodulators (space diversity reception) is shown. Viterbi decoding for the resulting quantized channel is discussed.

Calcium channels in the brain as targets for the calcium-channel modulators used in the treatment of neurological disorders

NARCIS (Netherlands)

Peters, Thies; WILFFERT, B; VANHOUTTE, PM; VANZWIETEN, PA

1991-01-01

Recent investigations of calcium channels in brain cells by voltage-clamp techniques have revealed that, in spite of electrophysiological similarities, the pharmacological properties of these channels differ considerably from channels in peripheral tissues, e.g., heart and smooth muscle. Therefore,

Ergodic Capacity for the SIMO Nakagami- Channel

Directory of Open Access Journals (Sweden)

Vagenas EfstathiosD

2009-01-01

Full Text Available This paper presents closed-form expressions for the ergodic channel capacity of SIMO (single-input and multiple output wireless systems operating in a Nakagami- fading channel. As the performance of SIMO channel is closely related to the diversity combining techniques, we present closed-form expressions for the capacity of maximal ratio combining (MRC, equal gain combining (EGC, selection combining (SC, and switch and stay (SSC diversity systems operating in Nakagami- fading channels. Also, the ergodic capacity of a SIMO system in a Nakagami- fading channel without any diversity technique is derived. The latter scenario is further investigated for a large amount of receive antennas. Finally, numerical results are presented for illustration.

Slack, Slick, and Sodium-Activated Potassium Channels

Science.gov (United States)

Kaczmarek, Leonard K.

2013-01-01

The Slack and Slick genes encode potassium channels that are very widely expressed in the central nervous system. These channels are activated by elevations in intracellular sodium, such as those that occur during trains of one or more action potentials, or following activation of nonselective cationic neurotransmitter receptors such as AMPA receptors. This review covers the cellular and molecular properties of Slack and Slick channels and compares them with findings on the properties of sodium-activated potassium currents (termed KNa currents) in native neurons. Human mutations in Slack channels produce extremely severe defects in learning and development, suggesting that KNa channels play a central role in neuronal plasticity and intellectual function. PMID:24319675

Superconducting muon channel at J-PARC

International Nuclear Information System (INIS)

Shimomura, K.; Koda, A.; Strasser, P.; Kawamura, N.; Fujimori, H.; Makimura, S.; Higemoto, W.; Nakahara, K.; Ishida, K.; Nishiyama, K.; Nagamine, K.; Miyake, Y.

2009-01-01

The Muon Science Laboratory at the Materials and Life Science Facility is now under construction in Japan Proton Accelerator Research Complex (J-PARC), where four types of muon channels are planned to be installed. A conventional superconducting muon channel will be installed at the first stage, which can extract surface (positive) muons and decay positive/negative muons up to 120 MeV/c, and the expected muon yield is a few 10 6 /s at 60 MeV/c (for both positive and negative). This channel will be used for various kinds of experiments like muon catalyzed fusion, μSR and nondestructive elements analysis. The present status of the superconducting muon channel is briefly reported.

Hydraulic jumps in a channel

DEFF Research Database (Denmark)

Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

2009-01-01

We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected......'s mixing-length theory with a mixing length that is proportional to the height of the fluid layer. Using averaged boundary-layer equations, taking into account the friction with the channel walls and the eddy viscosity, the flow both upstream and downstream of the jump can be understood. For the downstream...... subcritical flow, we assume that the critical height is attained close to the channel outlet. We use mass and momentum conservation to determine the position of the jump and obtain an estimate which is in rough agreement with our experiment. We show that the averaging method with a varying velocity profile...

HYTRAN: hydraulic transient code for investigating channel flow stability

International Nuclear Information System (INIS)

Kao, H.S.; Cardwell, W.R.; Morgan, C.D.

1976-01-01

HYTRAN is an analytical program used to investigate the possibility of hydraulic oscillations occurring in a reactor flow channel. The single channel studied is ordinarily the hot channel in the reactor core, which is parallel to other channels and is assumed to share a constant pressure drop with other channels. Since the channel of highest thermal state is studied, provision is made for two-phase flow that can cause a flow instability in the channel. HYTRAN uses the CHATA(1) program to establish a steady-state condition. A heat flux perturbation is then imposed on the channel, and the flow transient is calculated as a function of time

The Marketing Channels of China Auto Industry

Institute of Scientific and Technical Information of China (English)

our reporter

2001-01-01

<正> After the 1990’s, the multi-channel structure of sales has still existed although the market mechanism is playing a main role in Chinese auto marketing circulation. Now, the channels of automobile marketing in China are as follows: 1. Manufacturer-established marketing channels

Low-Complexity Bayesian Estimation of Cluster-Sparse Channels

KAUST Repository

Ballal, Tarig

2015-09-18

This paper addresses the problem of channel impulse response estimation for cluster-sparse channels under the Bayesian estimation framework. We develop a novel low-complexity minimum mean squared error (MMSE) estimator by exploiting the sparsity of the received signal profile and the structure of the measurement matrix. It is shown that due to the banded Toeplitz/circulant structure of the measurement matrix, a channel impulse response, such as underwater acoustic channel impulse responses, can be partitioned into a number of orthogonal or approximately orthogonal clusters. The orthogonal clusters, the sparsity of the channel impulse response and the structure of the measurement matrix, all combined, result in a computationally superior realization of the MMSE channel estimator. The MMSE estimator calculations boil down to simpler in-cluster calculations that can be reused in different clusters. The reduction in computational complexity allows for a more accurate implementation of the MMSE estimator. The proposed approach is tested using synthetic Gaussian channels, as well as simulated underwater acoustic channels. Symbol-error-rate performance and computation time confirm the superiority of the proposed method compared to selected benchmark methods in systems with preamble-based training signals transmitted over clustersparse channels.

Low-Complexity Bayesian Estimation of Cluster-Sparse Channels

KAUST Repository

Ballal, Tarig; Al-Naffouri, Tareq Y.; Ahmed, Syed

2015-01-01

This paper addresses the problem of channel impulse response estimation for cluster-sparse channels under the Bayesian estimation framework. We develop a novel low-complexity minimum mean squared error (MMSE) estimator by exploiting the sparsity of the received signal profile and the structure of the measurement matrix. It is shown that due to the banded Toeplitz/circulant structure of the measurement matrix, a channel impulse response, such as underwater acoustic channel impulse responses, can be partitioned into a number of orthogonal or approximately orthogonal clusters. The orthogonal clusters, the sparsity of the channel impulse response and the structure of the measurement matrix, all combined, result in a computationally superior realization of the MMSE channel estimator. The MMSE estimator calculations boil down to simpler in-cluster calculations that can be reused in different clusters. The reduction in computational complexity allows for a more accurate implementation of the MMSE estimator. The proposed approach is tested using synthetic Gaussian channels, as well as simulated underwater acoustic channels. Symbol-error-rate performance and computation time confirm the superiority of the proposed method compared to selected benchmark methods in systems with preamble-based training signals transmitted over clustersparse channels.

Monitoring inter-channel nonlinearity based on differential pilot

Science.gov (United States)

Wang, Wanli; Yang, Aiying; Guo, Peng; Lu, Yueming; Qiao, Yaojun

2018-06-01

We modify and simplify the inter-channel nonlinearity (NL) estimation method by using differential pilot. Compared to previous works, the inter-channel NL estimation method we propose has much lower complexity and does not need modification of the transmitter. The performance of inter-channel NL monitoring with different launch power is tested. For both QPSK and 16QAM systems with 9 channels, the estimation error of inter-channel NL is lower than 1 dB when the total launch power is bigger than 12 dBm after 1000 km optical transmission. At last, we compare our inter-channel NL estimation method with other methods.

Dark matter annihilation with s-channel internal Higgsstrahlung

Energy Technology Data Exchange (ETDEWEB)

Kumar, Jason; Liao, Jiajun, E-mail: liaoj@hawaii.edu; Marfatia, Danny

2016-08-10

We study the scenario of fermionic dark matter that annihilates to standard model fermions through an s-channel axial vector mediator. We point out that the well-known chirality suppression of the annihilation cross section can be alleviated by s-channel internal Higgsstrahlung. The shapes of the cosmic ray spectra are identical to that of t-channel internal Higgsstrahlung in the limit of a heavy mediating particle. Unlike the general case of t-channel bremsstrahlung, s-channel Higgsstrahlung can be the dominant annihilation process even for Dirac dark matter. Since the s-channel mediator can be a standard model singlet, collider searches for the mediator are easily circumvented.

Dark matter annihilation with s-channel internal Higgsstrahlung

International Nuclear Information System (INIS)

Kumar, Jason; Liao, Jiajun; Marfatia, Danny

2016-01-01

We study the scenario of fermionic dark matter that annihilates to standard model fermions through an s-channel axial vector mediator. We point out that the well-known chirality suppression of the annihilation cross section can be alleviated by s-channel internal Higgsstrahlung. The shapes of the cosmic ray spectra are identical to that of t-channel internal Higgsstrahlung in the limit of a heavy mediating particle. Unlike the general case of t-channel bremsstrahlung, s-channel Higgsstrahlung can be the dominant annihilation process even for Dirac dark matter. Since the s-channel mediator can be a standard model singlet, collider searches for the mediator are easily circumvented.

Channel and delay estimation for base-station–based cooperative communications in frequency-selective fading channels

Directory of Open Access Journals (Sweden)

Hongjun Xu

2011-07-01

Full Text Available A channel and delay estimation algorithm for both positive and negative delay, based on the distributed Alamouti scheme, has been recently discussed for base-station–based asynchronous cooperative systems in frequency-flat fading channels. This paper extends the algorithm, the maximum likelihood estimator, to work in frequency-selective fading channels. The minimum mean square error (MMSE performance of channel estimation for both packet schemes and normal schemes is discussed in this paper. The symbol error rate (SER performance of equalisation and detection for both time-reversal space-time block code (STBC and single-carrier STBC is also discussed in this paper. The MMSE simulation results demonstrated the superior performance of the packet scheme over the normal scheme with an improvement in performance of up to 6 dB when feedback was used in the frequency-selective channel at a MSE of 3 x 10^–2. The SER simulation results showed that, although both the normal and packet schemes achieved similar diversity orders, the packet scheme demonstrated a 1 dB coding gain over the normal scheme at a SER of 10^–5. Finally, the SER simulations showed that the frequency-selective fading system outperformed the frequency-flat fading system.

Chaos in quantum channels

Energy Technology Data Exchange (ETDEWEB)

Hosur, Pavan; Qi, Xiao-Liang [Department of Physics, Stanford University,476 Lomita Mall, Stanford, California 94305 (United States); Roberts, Daniel A. [Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, Massachusetts 02139 (United States); Yoshida, Beni [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena CA 91125 (United States)

2016-02-01

We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling.

Spark channel propagation in a microbubble liquid

Energy Technology Data Exchange (ETDEWEB)

Panov, V. A.; Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru; Vetchinin, S. P.; Pecherkin, V. Ya.; Son, E. E. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2016-11-15

Experimental study on the development of the spark channel from the anode needle under pulsed electrical breakdown of isopropyl alcohol solution in water with air microbubbles has been performed. The presence of the microbubbles increases the velocity of the spark channel propagation and increases the current in the discharge gap circuit. The observed rate of spark channel propagation in microbubble liquid ranges from 4 to 12 m/s, indicating the thermal mechanism of the spark channel development in a microbubble liquid.

Spin chain model for correlated quantum channels

Energy Technology Data Exchange (ETDEWEB)

Rossini, Davide [International School for Advanced Studies SISSA/ISAS, via Beirut 2-4, I-34014 Trieste (Italy); Giovannetti, Vittorio; Montangero, Simone [NEST-CNR-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)], E-mail: monta@sns.it

2008-11-15

We analyze the quality of the quantum information transmission along a correlated quantum channel by studying the average fidelity between input and output states and the average output purity, giving bounds for the entropy of the channel. Noise correlations in the channel are modeled by the coupling of each channel use with an element of a one-dimensional interacting quantum spin chain. Criticality of the environment chain is seen to emerge in the changes of the fidelity and of the purity.

An approach to implement virtual channels for flowing magnetic beads

International Nuclear Information System (INIS)

Tang, Shih-Hao; Chiang, Hung-Wei; Hsieh, Min-Chien; Chang, Yen-Di; Yeh, Po-Fan; Tsai, Jui-che; Shieh, Wung-Yang

2014-01-01

This work demonstrates the feasibility of a novel microfluidic system with virtual channels formed by ‘walls’ of magnetic fields, including collecting channels, transporting channels and function channels. The channels are defined by the nickel patterns. With its own ferromagnetism, nickel can be magnetized using an external magnetic field; the nickel structures then generate magnetic fields that can either guide or trap magnetic beads. A glass substrate is sandwiched between the liquid containing magnetic beads and the chip with nickel structures, preventing the liquid from directly contacting the nickel. In this work, collecting channels, transporting channels and function channels are displayed sequentially. In the collecting channel portion, channels with different shapes are compared. Next, in the transporting channel portion we demonstrate I-, S- and Y-shaped channels can steer magnetic beads smoothly. Finally, in the function channel portion, a switchable trapping channel implemented with a bistable mechanism performs the passing and blocking of a magnetic bead. (paper)

Differential Effects of TRPA and TRPV Channels on Behaviors of

Directory of Open Access Journals (Sweden)

Jennifer Thies

2016-01-01

Full Text Available TRPA and TRPV ion channels are members of the transient receptor potential (TRP cation channel superfamily, which mediates various sensory transductions. In Caenorhabditis elegans , the TRPV channels are known to affect chemosensation, while the TRPA-1 channel is associated with thermosensation and mechanosensation. We examined thermosensation, chemosensation, and osmosensation in strains lacking TRPA-1 or TRPV channels. We found that TRPV channel knockout worms exhibited similar behavioral deficits associated with thermotaxis as the TRPA-1 channel knockout, suggesting a dual role for TRPV channels. In contrast, chemosensation responses, assessed by both avoidance reversal behavior and NaCl osmosensation, were dependent on TRPV channels but seemed independent of TRPA-1 channel. Our findings suggest that, in addition to TRPA-1 channel, TRPV channels are necessary for thermotaxis and may activate, or modulate, the function of TRPA-1 channels. In contrast, TRPA-1 channels do not have a dual responsibility, as they have no functional role in odorant avoidance or osmosensation.

Perceived quality of channel zapping

NARCIS (Netherlands)

Kooij, R.E.; Ahmed, K.; Brunnström, K.

2006-01-01

The end user experience of service quality is critical to the success of a service provider's IPTV deployment program. A key element involved in validating IPTV quality of experience (QoE) is how quickly and reliably users can change TV channels, often referred to as channel zapping. Currently there

Minoxidil opens mitochondrial KATP channels and confers cardioprotection

Science.gov (United States)

Sato, Toshiaki; Li, Yulong; Saito, Tomoaki; Nakaya, Haruaki

2003-01-01

ATP-sensitive potassium channel in the mitochondrial inner membrane (mitoKATP channel) rather than in the sarcolemma (sarcKATP channel) appears to play an important role in cardioprotection. We examined the effect of minoxidil, a potent antihypertensive agent and hair growth stimulator, on sarcKATP and mitoKATP channels in guinea-pig ventricular myocytes. Minoxidil activated a glybenclamide-sensitive sarcKATP channel current in the whole-cell recording mode with an EC50 of 182.6 μM. Minoxidil reversibly increased the flavoprotein oxidation, an index of mitoKATP channel activity, in a concentration-dependent manner. The EC50 for mitoKATP channel activation was estimated to be 7.3 μM; this value was notably ≈25-fold lower than that for sarcKATP channel activation. Minoxidil (10 μM) significantly attenuated the ouabain-induced increase of mitochondrial Ca2+ concentration, which was measured by loading cells with rhod-2 fluorescence. Furthermore, pretreatment with minoxidil (10 μM) before 20-min no-flow ischaemia significantly improved the recovery of developed tension measured after 60 min of reperfusion in coronary perfused guinea-pig ventricular muscles. These cardioprotective effects of minoxidil were completely abolished by the mitoKATP channel blocker 5-hydroxydecanoate (500 μM). Our results indicate that minoxidil exerts a direct cardioprotective effect on heart muscle cells, an effect mediated by the selective activation of mitoKATP channels. PMID:14691056

An accurate mobility model for the I-V characteristics of n-channel enhancement-mode MOSFETs with single-channel boron implantation

International Nuclear Information System (INIS)

Chingyuan Wu; Yeongwen Daih

1985-01-01

In this paper an analytical mobility model is developed for the I-V characteristics of n-channel enhancement-mode MOSFETs, in which the effects of the two-dimensional electric fields in the surface inversion channel and the parasitic resistances due to contact and interconnection are included. Most importantly, the developed mobility model easily takes the device structure and process into consideration. In order to demonstrate the capabilities of the developed model, the structure- and process-oriented parameters in the present mobility model are calculated explicitly for an n-channel enhancement-mode MOSFET with single-channel boron implantation. Moreover, n-channel MOSFETs with different channel lengths fabricated in a production line by using a set of test keys have been characterized and the measured mobilities have been compared to the model. Excellent agreement has been obtained for all ranges of the fabricated channel lengths, which strongly support the accuracy of the model. (author)

Pharmaceutical Distribution Market Channels in Poland

Directory of Open Access Journals (Sweden)

Agnieszka Woś

2009-09-01

Full Text Available Distribution on the pharmaceutical market in Poland is interesting and the most difficult sphere to manage. Numerous varied and specialized companies operating on the market cause that the processes of choosing middlemen in distribution channels are very complex. The hereby article presents the role and location of the companies operating within distribution channels on the pharmaceutical market. It draws attention to the development of non-pharmacy and non-wholesale sales channels.

A self-regulating model of bedrock river channel geometry

Science.gov (United States)

Stark, C. P.

2006-02-01

The evolution of many mountain landscapes is controlled by the incision of bedrock river channels. While the rate of incision is set by channel shape through its mediation of flow, the channel shape is itself set by the history of bedrock erosion. This feedback between channel geometry and incision determines the speed of landscape response to tectonic or climatic forcing. Here, a model for the dynamics of bedrock channel shape is derived from geometric arguments, a normal flow approximation for channel flow, and a threshold bed shear stress assumption for bedrock abrasion. The model dynamics describe the competing effects of channel widening, tilting, bending, and variable flow depth. Transient solutions suggest that channels may take ~1-10 ky to adapt to changes in discharge, implying that channel disequilibrium is commonplace. If so, landscape evolution models will need to include bedrock channel dynamics if they are to probe the effects of climate change.

Dense Clustered Multi-Channel Wireless Sensor Cloud

Directory of Open Access Journals (Sweden)

Sivaramakrishnan Sivakumar

2015-08-01

Full Text Available Dense Wireless Sensor Network Clouds have an inherent issue of latency and packet drops with regards to data collection. Though there is extensive literature that tries to address these issues through either scheduling, channel contention or a combination of the two, the problem still largely exists. In this paper, a Clustered Multi-Channel Scheduling Protocol (CMSP is designed that creates a Voronoi partition of a dense network. Each partition is assigned a channel, and a scheduling scheme is adopted to collect data within the Voronoi partitions. This scheme collects data from the partitions concurrently and then passes it to the base station. CMSP is compared using simulation with other multi-channel protocols like Tree-based Multi-Channel, Multi-Channel MAC and Multi-frequency Media Access Control for wireless sensor networks. Results indicate CMSP has higher throughput and data delivery ratio at a lower power consumption due to network partitioning and hierarchical scheduling that minimizes load on the network.

Promotion through Marketing Channels : The Case of Kosovo

OpenAIRE

MSc. Hidajet Karaxha; MSc. Sejd Tolaj; Dr.Sc. Ilia Kristo

2016-01-01

In order for a product to be put in the hands of the customer, requires a mechanism which is called distribution channel and which enables the connection between the consumer and producer. One of the many strategies applied by Kosovar companies for the involvement of the members of the channel is also the promotion through distribution channels. Therefore, the strategies which involve the members of the channel have a higher probability to be positively accepted by the members of the channel,...

Secret Sharing over Fast-Fading MIMO Wiretap Channels

Directory of Open Access Journals (Sweden)

Bloch Matthieu

2009-01-01

Full Text Available Secret sharing over the fast-fading MIMO wiretap channel is considered. A source and a destination try to share secret information over a fast-fading MIMO channel in the presence of an eavesdropper who also makes channel observations that are different from but correlated to those made by the destination. An interactive, authenticated public channel with unlimited capacity is available to the source and destination for the secret sharing process. This situation is a special case of the "channel model with wiretapper" considered by Ahlswede and Csiszár. An extension of their result to continuous channel alphabets is employed to evaluate the key capacity of the fast-fading MIMO wiretap channel. The effects of spatial dimensionality provided by the use of multiple antennas at the source, destination, and eavesdropper are then investigated.

Plasma Channel Diagnostic Based on Laser Centroid Oscillations

International Nuclear Information System (INIS)

Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

2010-01-01

A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. The centroid position of low-intensity ( 14 Wcm -2 ) laser pulses focused at the input of a hydrogen-filled capillary discharge waveguide was scanned and the exit positions recorded to determine the channel shape and depth with an accuracy of a few %. In addition, accurate alignment of the laser beam through the plasma channel can be provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.

The secret life of ion channels: Kv1.3 potassium channels and proliferation.

Science.gov (United States)

Pérez-García, M Teresa; Cidad, Pilar; López-López, José R

2018-01-01

Kv1.3 channels are involved in the switch to proliferation of normally quiescent cells, being implicated in the control of cell cycle in many different cell types and in many different ways. They modulate membrane potential controlling K + fluxes, sense changes in potential, and interact with many signaling molecules through their intracellular domains. From a mechanistic point of view, we can describe the role of Kv1.3 channels in proliferation with at least three different models. In the "membrane potential model," membrane hyperpolarization resulting from Kv1.3 activation provides the driving force for Ca 2+ influx required to activate Ca 2+ -dependent transcription. This model explains most of the data obtained from several cells from the immune system. In the "voltage sensor model," Kv1.3 channels serve mainly as sensors that transduce electrical signals into biochemical cascades, independently of their effect on membrane potential. Kv1.3-dependent proliferation of vascular smooth muscle cells (VSMCs) could fit this model. Finally, in the "channelosome balance model," the master switch determining proliferation may be related to the control of the Kv1.3 to Kv1.5 ratio, as described in glial cells and also in VSMCs. Since the three mechanisms cannot function independently, these models are obviously not exclusive. Nevertheless, they could be exploited differentially in different cells and tissues. This large functional flexibility of Kv1.3 channels surely gives a new perspective on their functions beyond their elementary role as ion channels, although a conclusive picture of the mechanisms involved in Kv1.3 signaling to proliferation is yet to be reached.

Square root approximation to the poisson channel

NARCIS (Netherlands)

Tsiatmas, A.; Willems, F.M.J.; Baggen, C.P.M.J.

2013-01-01

Starting from the Poisson model we present a channel model for optical communications, called the Square Root (SR) Channel, in which the noise is additive Gaussian with constant variance. Initially, we prove that for large peak or average power, the transmission rate of a Poisson Channel when coding

Molecular determinants in TRPV5 channel assembly.

NARCIS (Netherlands)

Chang, Q.; Gyftogianni, E.; Graaf, K.F.J. van de; Hoefs, S.J.G.; Weidema, A.F.; Bindels, R.J.M.; Hoenderop, J.G.J.

2004-01-01