Clear evidence for massive addition of 13C-depleted carbon at the onset of the PETM comes from two observations. First, a prominent negative excursion in the carbon isotope composition (δ13C) of carbon-bearing phases characterizes the PETM in numerous widespread locations from a range of environments. Second, carbonate dissolution marks the PETM in sections from the deep-sea.The total mass of carbon injected to the ocean and atmosphere during the PETM remains the source of debate. In theory, it can be estimated from the magnitude of the δ13C excursion, the amount of carbonate dissolution on the seafloor, or ideally both. However, the shift in the δ13C across the PETM depends on the location and the carbon-bearing phase analyzed. In some records of bulk carbonate, it is about 2‰; in some records of terrestrial carbonate or organic matter it exceeds 6‰.Carbonate dissolution also varies throughout different ocean basins. It is extreme in parts of the north and central Atlantic Ocean but far less pronounced in the Pacific Ocean. With available information, estimates of the carbon addition range from about 2500 to over 6800 gigatons None of the above causes are alone sufficient to cause the carbon isotope excursion or warming observed at the PETM. The most obvious feedback mechanism that could amplify the initial perturbation is that of clathrates. At certain temperature and pressure conditions, methane – which is being produced continually by decomposing microbes in sea bottom sediments – is stable in a complex with water, which forms ice-like cages trapping the methane in solid form. As temperature rises, the pressure required to keep this clathrate configuration stable increases, so shallow clathrates dissociate, releasing methane gas to make its way into the atmosphere. Since biogenic clathrates have a δ13C signature of ?60 ‰ (inorganic clathrates are the still rather large ?40 ‰), relatively small masses can produce large δ13C excursions. Further, methane is a potent greenhouse gas as it is released into the atmosphere, so it causes warming, and as the ocean transports this warmth to the bottom sediments, it destabilises more clathrates. It would take around 2,300 years for an increased temperature to diffuse warmth into the sea bed to a depth sufficient to cause a release of clathrates, although the exact time-frame is highly dependent on a number of poorly constrained assumptions.[35] Ocean warming due to flooding and pressure changes due to a sea-level drop may have caused clathrates to become unstable and release methane. This can take place over as short of a period as a few thousand years. The reverse process, that of fixing methane in clathrates, occurs over a larger scale of tens of thousands of years.
Expensive Reading:
http://zerolang.jigsy.com/entries/general/post-launch-development-
http://blogs.realtown.com/sopto/2013/06/10/customs-and-traditions-in-china/
http://www.alivenotdead.com/zerolang/List-of-Swedish-football-champions-profile-3076448.html
WASACE Cable Co. says it has begun the process of selecting a cable system supplier for its planned undersea network that will link the United States with Africa, with links as well to Brazil and Europe.WASACE says its plans to deploy 100-Gbps technology across three cable systems:WASACE Americas will connect Brazil (Santos, Rio de Janeiro, and Fortaleza) to the U.S. (Florida). WASACE Americas will also provide optional, on demand connectivity to Colombia, Panama, and South Carolina.WASACE Africa will link Nigeria and South Africa to the USA. WASACE Africa also will offer optional, on demand connectivity to the Niger-Delta Oil and Gas region at Bonny Island and to Angola.WASACE Europe will connect Florida to Virginia Beach and across the North Atlantic to San Sebastian, Spain.Telecommunications consultants David Ross Group will administer the procurement process and lead the development of the project. WASACE says it has released the Invitation to Tender to four undersea telecommunications cable system suppliers. It expects to select the cable system supplier(s) for its network in July 2012.Meanwhile, WASACE has retained two financial services companies, including Aterios Capital, as financial advisors to source funding for the project.The company plans to develop the network in phases, beginning with the WASACE Americas and WASACE Africa cable systems, which are scheduled to be in service by the first quarter of 2014.“We believe this project is timely and provides a unique opportunity for free flow of information and data between the two largest economies in the Americas (USA and Brazil), Africa’s largest economy (South Africa), and Africa’s fastest growing economy (Nigeria) as well as with the rest of the world. It ties in with our focus on infrastructure development in sub-Saharan Africa and we are proud to be associated with it,” says Olabode Abikoye, CEO of Aterios Capital.Motorola Mobility, Inc. (NYSE: MMI) says that it plans to unveil the 1-GHz 2×2 VSN200 Optical Node at The Cable Show this month in Boston. The optical node is the latest addition to Motorola’s end-to-end 1-GHz Broadband Access Networks (BAN) product line.As part of the BAN product family the VSN200 Optical Node is designed to enable cable operators to expand the bandwidth capacity of their existing infrastructures and support additional HD channels and video-on-demand capabilities, as well as higher data-rate downstream and upstream services. The VSN200 enables operators to repurpose existing housings by installing the new system using only an Electronics Package (E-Pack) and Lid swap. This easy installation process avoids the downtime of cutting out the entire node to make the upgrade, Motorola points out.
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http://sopto.wordpress.com/2013/06/10/global-communities-are-a-must/
http://sfpdirectattchcables.jimdo.com/2013/06/10/week-news-abstract-for-sfp-series/
The exodus from Egypt is the theme of the Jewish holiday of Passover (“pesa?”); the term continues to be used in the Passover Hagadah.At the beginning of the Exodus narrative the Israelites are instructed to prepare unleavened bread as they will be leaving in haste, and to mark their doors with blood of the slaughtered sheep so that the “Angel” or “the destroyer” will “pass over” them while killing the first-born of Egypt. The Hebrew name for the festival, “Pesa?”, refers to the “skipping over”, “jumping over” or “passing over” by God over the Jewish houses while killing the first born of Egypt. (Despite the biblical story, scholars believe that the passover festival originated in a magic ritual to turn away demons from the household by painting the doorframe with the blood of a slaughtered sheep.)Jewish tradition has preserved national and personal reminders of this pivotal narrative into daily life. Examples of such reminders include the wearing of ‘tefilin’ (phylacteries) on the hand and forehead, which some Jews practice daily; the wearing of ‘tzitzit’ (knotted ritual fringes attached to the four corners of the prayer shawl); the eating of ‘matzot’ (unleavened bread) during the Pesach (Passover) holiday; the fasting of the firstborn a day before Pesach; the redemption of firstborn children and animals; and even the observance of the Sabbath.John Van Seters (born Hamilton, Ontario, Canada, 2 May 1935) is a scholar of the Hebrew Bible (Old Testament) and the Ancient Near East. Currently University Distinguished Professor Emeritus at the University of North Carolina, he was formerly James A. Gray Professor of Biblical Literature at UNC. He took his PhD at Yale University in Near Eastern Studies (1965) and a ThD h.c. from the University of Lausanne (1999). His honours and awards include a Guggenheim Fellowship, an NEH fellowship, an ACLS fellowship, and research fellowships at Oxford, Cambridge, Katholieke Universiteit Leuven, and National Research Fund of South Africa. His many publications include “The Hyksos, A New Investigation” (1966); “Abraham in History and Tradition” (1975); “In Search of History” (1983, for which he won the James H. Breasted Prize and the American Academy of Religion book award); “The Edited Bible” (2006); and “The Biblical Saga of King David” (2009). “Changing Perspectives I: Studies in the History, Literature and Religion of Biblical Israel”, a collection of articles from 1964 onwards with an introduction by Thomas L. Thompson, will appear in mid-2011.
Expensive Reading:
http://edfa1.blog.fc2.com/blog-entry-199.html
http://blogs.realtown.com/sopto/2013/06/10/nuclides-and-isotopes/
http://sfpdirectattchcables.jimdo.com/2013/06/10/news-sfp-series/
A strip waveguide is basically a strip of the guiding layer confined between cladding layers. The simplest case is a rectangular waveguide, which is formed when the guiding layer of the slab waveguide is restricted in both transverse directions rather than just one. Rectangular waveguides are used in integrated optical circuits, and in laser diodes.
They are commonly used as the basis of such optical components as Mach-Zehnder interferometers and wavelength division multiplexers. The cavities of laser diodes are frequently constructed as rectangular optical waveguides. Optical waveguides with rectangular geometry are produced by a variety of means, usually by a planar process.The field distribution in rectangular waveguide cannot be solved analytically, however approximate solution methods, such as Marcatili’s method, are known.Rib waveguidesA rib waveguide is a waveguide in which the guiding layer basically consists of the slab with a strip (or several strips) superimposed onto it. Rib waveguides also provide confinement of the wave in two dimensions.
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The bearer channel (B) is a standard 64 kbit/s voice channel of 8 bits sampled at 8 kHz with G.711 encoding. B-Channels can also be used to carry data, since they are nothing more than digital channels.Each one of these channels is known as a DS0.Most B channels can carry a 64 kbit/s signal, but some were limited to 56K because they traveled over RBS lines. This was commonplace in the 20th century, but has since become less so.
X.25 can be carried over the B or D channels of a BRI line, and over the B channels of a PRI line. X.25 over the D channel is used at many point-of-sale (credit card) terminals because it eliminates the modem setup, and because it connects to the central system over a B channel, thereby eliminating the need for modems and making much better use of the central system’s telephone lines.X.25 was also part of an ISDN protocol called “Always On/Dynamic ISDN”, or AO/DI. This allowed a user to have a constant multi-link PPP connection to the internet over X.25 on the D channel, and brought up one or two B channels as needed.
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Flexible network management. A tunable SFP+ transceiver will be remotely configured for a specific wavelength to support bandwidth changes as needed in Enterprise or Metro networks.
Reduced network inventory. One tunable SFP+ transceiver will support more than 80 different wavelengths. It will allow network operators to hold one tunable device code as opposed to 80+ fixed wavelength transceivers.Reduced power consumption. It will provide a significant reduction in electrical power dissipation compared to other tunable solutions.
Compact and high-density form factor. The new tunable SFP+ transceiver will be about the size of a pack of gum, saving valuable real estate in data centers.
Increased network capacity. The tunable SFP+ will double the number of channels supported in this compact transceiver form factor. Upgrading to 50GHz channel spacing doubles the capacity potential in Enterprise and Metro networks. The tunable SFP+ will also replace larger and less efficient legacy products such as the X2 and XenPack transceivers.
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TOSA/ROSA Receptacles also have a function of aligning the Optical Module Axis. They are assembled with ferrules and precision lathe metal parts.TOSA/ROSA Receptacles are normally built with 1.25mm or 2.5mm fiber stubs and ceramic split sleeves, both made exclusively in high performance Ceramic (Zirconia).
TOSA/ROSA Receptacle consisting of a built in Fiber Stub are the most important Optical Module Component. Receptacles connect optical connectors with Optical Modules commonly known as TOSA/ROSA Assemblies.
We are sufficient to make many kinds of TOSA/ROSA receptacle according to customer design with integrated function of our facilities. Base on our machining techniques. We can make various type of main body, and also cut and polish the fiber stub by ourselves. We supply SC and LC TOSA/ROSA Receptacle. However other dimensions are available. Our fiber stub features good reflection loss and PC or APC end face thus low insertion loss; Our metal ferrule housings with various Stainless Steel (SUS) Materials such as SUS303, SUS304 can be offered with custom configurations and designs.
Besides TOSA/ROSA Receptacle, we also offer Fiber Stub for Optical Subassembly (OSA) and Metal Ferrule for LD-PD fiber pigtail.
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Culture Secretary Jeremy Hunt has signalled his support for a community super-fast broadband scheme in rural north Lancashire.
Mr Hunt was asked by Lancaster and Fleetwood MP Eric Ollerenshaw whether he would be prepared to meet the Broadband for the Rural North (B4RN) group to see what can be done to maintain the momentum of this vital project.
In response, the Culture Secretary stressed that the government is eager to support projects such as this in any way possible and said either he or Communications Minister Ed Vaizey would be delighted to meet him and his constituents.
B4RN is currently working on the rollout of a 1Gbps fibre optic broadband network to a rural area east of Lancaster.
The scheme has been launched as local residents and businesses fear the community is unlikely to be included in private sector broadband deployments.
Project leaders are hoping to connect around 1,400 commercial and residential properties in north Lancashire to the infrastructure, with the rollout getting underway at the end of March.
B4RN co-founder Chris Conder welcomed Mr Hunt’s announcement, commenting: There is so much to be done and all help is gratefully received.
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In addition to a power meter, you need a test source. The test source should match the type fiber ( generally LED for MM or laser for SM) and wavelength (850, 1300, 1550 nm) that will be used on the fiber optic cable you are testing. If you are testing to some standards, you may need to add some mode conditioning, like a mandrel wrap, to meet the standard launch conditions.
You generally need one or two reference cables, depending on the test we wish to perform. The accuracy of the measurement you make will depend on the quality of your reference cables, since they will be mated to the cable under test. The quality and cleanliness of the connectors on the launch and receive cables is the most important factor in the accuracy of loss measurements. Always test your reference cables by the patchcord or single ended method shown below to make sure they’re good before you start testing other cablesStandards groups have not been able to successfully specify the quality of reference cables in terms of tightly toleranced components like the fiber and connectors. The best recommendation for qualifying reference cables is to choose cables with low loss, tested “single-ended” per FOTP-171 below.
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Sumitomo Electric Industries, Ltd. (TOKYO: 5802) (ISIN: JP3407400005) will unveil three new optical modules during OFC/NFOEC this week at booth. The modules address 40-Gbps and 100-Gbps applications.
Sumitomo Electric will debut two 40-Gbps devices The first, a 40G-LR4 QSFP+, targets data centers that use multiple tiers of networks to aggregate and link traffic. The QSFP+ format offers improvements in real estate, power, and port density over typically larger modules now in use. The new device complies with the QSFP+ Multi-Source Agreement (MSA), consumes a maximum of 2.5 W, and will support both IEEE802.3ba (40GBase-LR4) and ITU-T G.695 (OTU3) operation over as much as 10 km via standard singlemode fiber. Sumitomo will demonstrate the QSFP+ using an IXIA QSFP+ load module.
The other 40-Gbps module is what Sumitomo Electric asserts is the first 40G-FR CFP for 2 km applications. It is enabled via Sumitomo Electric’s high speed 40-Gbps electro-absorption modulator integrated laser diode for the optical transmitter and a high-speed PIN photodiode for the optical receiver. The 40G-FR CFP can support both IEEE 802.3bg (40GBase-FR) and ITU-T G.693 (OTU3); its maximum power consumption is compliant with CFP MSA power class 2.
The CFP demonstration will use the Anritsu MD1260A test instrurment for 40GbE. Sumitomo Electric has already released the 40GbE CFP optical transceiver for 10-km (40G-LR4) and 40-km (40G-ER4) reach. The 40G-FR CFP modules are shipping now with mass production planned for the second quarter of 2012.
At 100 Gbps, Sumitomo Electric will have a new 100G-LR4 CFP Low Power module for singlemode fiber connections of up to 10 km. The new module incorporates a CMOS-based Gearbox IC that requires only about two-thirds of the current 100G-LR4 CFP (maximum 16 W), the company says. The 100G-LR4 CFP modules offer customers IEEE802.3ba (100GBASE-LR4) and ITU-T G.959.1 (OTU4) connectivity options for data center, enterprise wiring closet, and service provider transport applications.
The company also will display its 10-Gbps DWDM and CWDM transceivers in the SFP+ form factor. The SFP+ transceivers can be used in metro and other telecom markets and include Limiting/Linear 80-km DWDM and 40-km/70-km CWDM SFP+ modules.
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mediaconverterb 