In-field QC of a land node seismic system

The purpose of this study was to obtain information regarding single and multi channel VHF and UHF radio signal booster systems which have been constructed in subway and highway tunnels in Europe and to disseminate this information in the U.S.A. Early in 1977, while the author was engaged in designing a UHF radio system for a subway, he learned that low power radio signal booster systems using a daisy chain of amplifiers (similar to a CATV trunk line) were being used in coal mines in the United Kingdom and that London Transport was installing a signal booster system in the Bakerloo Tube to replace a conventional system that had used a base station to feed a tee section of leaky coaxial cable. This new system used low power signal booster amplifiers spaced 500 meters apart to compensate for the attenuation in the leaky coaxial cable antenna system. The design was based upon similar systems which were used in coal mines in the United Kingdom and it afforded a number of advantages over conventional multiple base station systems used in the U.S.A. such as: • Signal strengths throughout the tunnel system are uniform. • Only one base station per radio channel is needed for a typical subway; this substantially reduces costs for renovating space for radio systems in existing subways and also eliminates hetrodyne interference that occurs at transitions between the ends of adjacent antennas. • If wide band class A linear signal booster amplifiers (similar to CATV line amplifiers) are used, a number of channels can be readily and more economically provided for train communications, maintenance, security, fire, police and para-medical services. • Fewer control circuits are needed and central control facilities and operations are simpler. • Equipment, installation and operating costs are lower. In August, 1977, the author visited Dr. D.J.R. Martin, co-inventor of the daisy chain concept and London Transport and obtained information regarding the VHF radio system in the Bakerloo Tube which was summarized in a paper that he presented at the 28th IEEE Vehicular Technology Conference at Denver, Colorado, in March, 1978. A somewhat similar VHF signal booster system was designed for the new U-1 subway in Vienna by German and Austrian engineers who evidently were not aware of the work that had been done in England. The Vienna system was visited in 1978 shortly after the subway was commissioned and its performance was superior to conventional systems used on other subway lines. The subways in Munich and Milan also were visited, but they used conventional base stations to feed tee sections of leaky coaxial cable antenna. A unique multi-channel radio signal booster system for extending AM and FM broadcasting and seven two way VHF public safety channels into two 395 meter highway tunnels in Brussels was visited in 1979 and the designers of the system were interviewed. A single discone antenna constructed of meta½ rods is used for both transmitting and receiving. The Swiss Posts, Telephone and Telegraphs (PTT) authority in Switzerland has developed an eleven channel VHF two way signal booster system for their long highway tunnels. FM broadcasting (87.6 - 104 MHz) as well as two way VHF radio telephone, police, fire and maintenance services will be accommodated. A list of persons in Europe who are engaged in development research or operation of radio systems using signal boosters (in-line repeater amplifiers) in tunnels is included in Appendix 1.

SPE 3578l Abstract Louisiana swamps have been host to seismic crews for many years. Results from recent 3D surveys indicate that well planned and executed seismic operations have a minimal and short term impact in these environmentally sensitive wetlands. Pre-planning identifies challenges that require use of improved technology and work procedures. These include multi-channel radio telemetry recording systems, ramming of dynamite and hydrophones as opposed to drilling, DGPS positioning and co-ordin and use of Airboats, buggies and helicopters. In addition to minimal environmental impact, increased data quality, reduced cost and shorter project duration have been achieved as a result of these efforts. Unlike 2D surveys, where profile positioning is flexible, 3D surveys involve high density coverage over many square miles operated by numerous personnel. Survey design includes minimizing repeated traffic and crossing points. Survey operations require environmental participation and commitment from every person involved in the project. This includes a thorough orientation and training program with strong emphasis on environmental sensitivity and awareness. Close co-ordination between regulatory agencies, clients and the contractor is a key factor in all aspects of the survey planning and operation. Benefits from these efforts are significant, measurable and continue to improve. Introduction The Louisiana Wetlands, (See figure 1), have for many years been host to seismic exploration. These environmentally sensitive areas range from open marshland and thick cypress swamp to mangrove swamp, shallow lakes and coastal transition zones. They extend from the State of Mississippi to the State of Texas and go inland for many miles from the Gulf of Mexico. The parishes where most Wetland exploration occurs are, from east to west, St Bernard, Plaquemines, Jefferson, Lafourche, Terrebone, St Mary, Assumption, St. Martin, Vermilion and Cameron. A typical 3D survey would entail crossing levees, marshland, shallow lakes and agricultural land. Water conditions range from salt and fresh to brackish. The Louisiana Wetlands are home to an extensive range of wild life including alligators, nutrias, rats, snakes, raccoons, deer, pelicans, cranes, and many other bird species. Many species of reptiles birds and mammals are protected and / or on the endangered species list. Wetland areas are often open to the public for leisure activities such as fishing, boating and hunting. Practically all shallow open wetland areas in Louisiana are commercially fished seasonally, with shrimping and oyster collection being the main business. 3D seismic data acquisition surveys require high density coverage over many square miles necessitating the use of much equipment and many personnel. Unlike 2D operations where single line recording is relatively short, 3D rations require that the source and receiver lines be positioned over a longer period of time. This is directly related to the size of the survey and how many channels and shots are required to obtain data. Survey sizes are typically 60 to 120 square miles. Seismic acquisition is only a very small part of the oil and gas exploration and production picture. Compared with production facility installation, laying pipelines or the historical drilling practices of cutting access canals the impact of seismic crews is minimal. Whereas production facilities are permanent, seismic exploration should leave no ending marks on the landscape. The environmental challenge The challenge of operating seismic acquisition crews in the Louisiana wetlands is to minimize or eliminate the impact that crew operations could have on the prospect area's environment. Methods used to overcome the challenge. Preplanning To minimize the environmental impact to the Wetlands extensive preplanning of all surveys is required, the importance of which cannot be overemphasized. P. 213

The history of South Atlantic palaeogeography begins with the supercontinent, Pangaea. The assembly of Pangaea began with the middle Palaeozoic collision of north-western Europe with North America on the west and the Siberian platform on the east to form the continent called Laurussia. Shortly thereafter (geologically), Gondwana collided with Laurussia. The final assembly of Pangaea occurred in the Early Triassic with the collision between North and South China that raised the Chinling Range (J. M. Parrish et al. 1986). No sooner had Pangaea come together than it began breaking up. Continental deposits associated with the initial rift valleys in eastern North America are Triassic in age. The Central Atlantic opened first between north-western Africa and south-eastern North America. Because South America and Africa were still one plate, the opening of the Central Atlantic caused relative motion between North and South America; the Gulf of Mexico and eventually the Caribbean formed in the intervening space. The opening of the South Atlantic began in the Early Cretaceous. The final plate separation in the circum-Atlantic region was between North America and north-western Europe. The central focus of this book is the history of connections between Africa and South America, and so the history of the South Atlantic forms the principal focus of this chapter. However, connections between North and South America and Africa and Europe (and thus North America) are also discussed.

Aiming at the status of the domestic and international wireless sensor network real-time acquisition system in the practical application, the program building real-time acquisition system by advanced technology of acceleration sensor detection, wireless network data transmission, and ZigBee protocol network is proposed. In view of the monitoring system automation, wireless transmission system network and modular system design, this wireless sensor network real-time acquisition system resolves the shortcomings, such as high cost of cable transmission system installation and environmental interference susceptible signals effectively. It has the advantages of easy installation and being real-time.

Plant species disjunctions have attracted the interest of ecologists for decades. We investigated Trichloris crinita, a native C4 perennial grass with disjunct distribution between subtropical regions of North and South America, testing the hypothesis that the species has a similar realized climatic niche in both subcontinents. The climatic niche of T. crinita in North and South America was characterized and compared using presence records and five uncorrelated bioclimatic variables selected according to their ecological importance for the species. We used reciprocal modeling to make geographic projections of the realized niche within each subcontinent. Niche overlap between T. crinita distributions in North and South America was intermediate for the individual climatic variables and the multivariate space. In all cases the test of equivalence between climates inhabited by T. crinita indicated that the realized niche of the species differ significantly between subcontinents. Also, the similarity test showed that in the majority of cases the realized niche in both subcontinents was significantly different than that expected by chance. T. crinita occupied a greater diversity of environments in South than in North America, while in the latter its distribution was displaced to drier and warmer environments. The modeled geographic distribution using the actual occurrences of the species in North America did not accurately predict the distribution in South America, and vice versa. Together, these results led us to reject the hypothesis of similar niche of T. crinita in both subcontinents. This information may be useful to manage restoration efforts by presenting the suitable areas and climates for the species, and suggesting that translocation of individuals between subcontinents could only be recommended with caution because introduced genotypes can be potentially maladaptive, and could colonize sites actually not occupied by the species within each subcontinent.

Aim Several mechanisms contribute to the plant biodiversity of the Neotropics, with the highlands of South America serving as important hotspots of diversity. In particular, the Brazilian highlands exhibit high biodiversity due to complex diversification dynamics and a mixture of contributions from different biomes. In this study, we reconstruct the timing and potential triggers of diversification of Agalinis , hemiparasitic plants that inhabit open grassland habitats, to investigate their biogeographic history and migration patterns across the Americas. Location North, Central and South America. Taxon Agalinis . Methods We reconstructed dated phylogenies of Agalinis using a secondary calibration approach, sampling 73% of the known species, including multiple species from the Andes and Brazilian highlands. We inferred ancestral distributions to understand migration patterns between North and South America and within South America. Additionally, we investigated shifts in diversification rates within the genus and reconstructed ancestral pollination syndrome and life‐history strategy states. All analyses were performed across a distribution of trees to account for phylogenetic uncertainty. Results Agalinis likely originated in south‐eastern North America during the early Miocene and rapidly diversified, followed by movement into South America in the Late Miocene or Early Pliocene. We propose two possible routes for Agalinis movement into South America: either through the Andes or via the South American lowland grasslands (e.g., Chaco, Pampas, Cerrado, Caatinga, Llanos), using grassland corridors for dispersal within the continent. After its arrival in South American highlands, the clade underwent rapid diversification. State reconstructions indicated that the genus had a bee‐pollinated ancestor and that hummingbird pollination evolved only once, with many transitions back to bee pollination. In contrast, the perennial life strategy evolved multiple times within the genus, including at least once in the ancestor of all South American species and twice in the North American species. Main Conclusions Agalinis likely originated in North America and later migrated to South America, followed by rapid diversification (i.e., ‘dispersification’). Thus, Agalinis is a clade that refutes the tropical conservatism hypothesis and the out‐of‐the‐tropics model. Moreover, the dispersal to the Brazilian highlands was from nearby species pools and not from other highland habitats such as the Andes, followed by several in situ speciation events. These high diversification rates were partly associated with Quaternary climatic oscillations, and perennial and hummingbird‐pollinated species exhibited higher turnover rates.

Amphitropical species have disjunct distributions south and north of the equator. That is the case of Leptochloa crinita, a perennial grass found in dry and warm regions of South and North America, and recommended for rangeland restoration. We analyzed to what degree the distribution of the species in both subcontinents shaped its genetic differentiation and population variability. We collected seeds from 15 populations from South America and 7 from North America, and grew them in a common garden to evaluate adaptive variation. Three microsatellite markers and DNA sequences from one nuclear (ITS1-5.8S-ITS2) and one chloroplast region (rpl32-trnL) were used to analyze recent and historical gene flow, respectively. We used climatic niche models to infer past suitable habitats. We found significant genetic variability among populations within each subcontinent, but low genetic differences between populations from South vs. North America; these were detected only with microsatellites and not with DNA sequences. Results show that the species has diverged from a common gene pool in the recent past (~500-3300 generations ago [estimate: ~3000-20000 years]). Populations from South America had plants with more and taller inflorescences, more tillers and heavier seeds than the North American ones, which could represent adaptations to the less stressful environments that the species inhabits in South America. Climatic niche models indicate few potential habitats for the species in North America during the Last Glacial Maximum and Middle Holocene, in contrast to South America, where potential habitats seemed to be comparable or more extensive than at present. This and previous studies provide a view of the genetic resources of the species. Results suggest that —if necessary, and taking proper precautions— the admixture of L. crinita populations or the germplasm translocation between subcontinents are alternatives to consider in restoration practices.

Diversity of limno-terrestrial tardigrades of the Americas in relation to the Great American Biotic Interchange hypothesis (GABI)

Marine multicomponent seismology has seized the geophysical industry's fancy since it made its semicommercial emergence in the North Sea in the autumn of 1996. This technology involves the recording of S-waves, in addition to the conventional P-waves, by deploying on the seafloor sensor packages containing hydrophones plus 3-component geophones. New processing algorithms have had to be developed to properly process these data. The major uses of this type of data have been (1) to image beneath gas clouds and chimneys, (2) to better infer lithologic and pore fluid information some distance away from wells, and (3) to image beneath high velocity bodies such as salt and basalt masses. The future looks bright for this technology, for reservoir characterization, for seismic time-lapse monitoring (4D), for reservoir management, and perhaps even for exploration. On the order of 110 4-component marine surveys have been acquired since September, 1996, the vast majority of them being 2D. However, the number of 4C 3D surveys is growing at a faster rate than the number of 4C 2D surveys, the processing of the first handful of 3D 4C surveys has been completed, and the information content of these data sets has been very high, and very useful. 4C surveys have been conducted in the North Sea, the Far East, offshore West Africa, Cook Inlet, the Middle East, and in the Gulf of Mexico. The overall experience is that the data quality in all locations is relatively high, the acquisition systems couple reasonably well to the seafloor, and the bulk of the modeconverted S-wave energy derives from P-waves modeconverting to S at depth, and not at the seafloor. Four fundamentally different acquisition systems are used in the industry today to acquire the P- and S-wave data: three different cable-based systems, as well as one node-type system. There are at least three different modes of deployment of the cable systems: dragging the cable into place, draping it under tension, and draping it not under tension. A remotely operated vehicle (ROV) emplaces the node-type system. While data quality certainly is not uniform across the industry at the present time, it is not clear yet how system construction and deployment directly affect the data quality. More analysis and research is needed in this area, and is forthcoming no doubt. The cost to acquire 3D marine multicomponent data is 3-6 times more expensive than conventional towed streamer 3D, but that is expected at this stage of the development of the technology. The cost will decrease fairly dramatically in the future as capacity and production rates increase. What Is Marine 4-Component Seismology? In the context of this article, marine 4-component seismology (M4C) is the technology that places 4-component sensing systems on the seafloor so as to record the full vector wavefield of passing stress waves. In a simplistic sense, this means the recording of both compressional waves (P-waves) and shear waves (S-waves). Further, M4C supplies sufficient data processing to make interpretation of the data possible. Finally, it provides for more complete interpretation of reservoir properties, including reservoir boundaries, than is provided by the more conventional 1- or 2-component (Pwave) technology that is far more prevalent in the offshore industry today. The four components of M4C are a hydrophone, a vertical geophone, and two horizontal geophones oriented perpendicular to each other, and all four are included in each receiver group. Conventional marine towed-streamer systems are 1-component systems and use only hydrophones as the sensor of seismic signals, and record directly only P-waves. onventional OBC (ocean bottom cable) systems e

RAPD analysis of the relationship of North and South American subspecies of <i>Fragaria chiloensis</i>

Nowadays cableless seismic is widely developed for land and marine applications. Comparing cable and cableless systems two key parameters have to be considered: data quality and operation cost. The data quality/operation cost ratio should be maximized in modern seismic. How to compare this ratio for cable and cableless systems? GeoEnergyGroup and SeismoShelf decided to joint efforts in order to carry out two filed experiments: land and marine for both systems simultaneously. SeismoShelf contributed with 4C seismic nodes and GeoEnergyGroup organized two test sites with on-going industrial acquisitions with cable systems. Finally two seismic surveys: onshore and offshore have been performed. Field data acquired with cable and nodal systems are demonstrated and discussed.

This paper demonstrates a wireless ECG acquisition and classification system with a bio-signal processor (BSP), a super regenerative transceiver, and a digital signal processor (DSP). The BSP, which is implemented with low complexity architecture, includes only a low noise amplifier with chopping techniques and a high-pass sigma-delta modulator (HPSDM). The super-regenerative on-off keying (OOK) transceiver is applied for the low power, short range transmission and low date rate wireless communication. For the signal processing and analyzing, the DSP circuit is adopted in the receiver. The whole system is implemented in a TSMC 0.18 µm 1P6M CMOS process under the supply voltage of 1.2 V. In the near body node, the power consumption including a BSP and a transmitter is 587 µW only. With two PR44 zinc-air batteries of 605 mAh, the near body node circuit can be operated about 100 days. In the receiving node, the power consumption with a receiver and a DSP is 926 µW.

Considering the problem of miss reference database for previous patient’s data and miss interconnection between the medical environment units includes the physician, pharmacy, laboratory, etc… This paper aims to provide an interconnection between the medical environment units and physiological data which describe the conditions of his/her health to provide an important monitoring for the patient veracity. The proposed system consists of two main parts: data entry and querying system and wireless monitoring and acquisition system. The first part is a desktop application with database in the server. The second part consists of two wireless units: patient unit and hospital unit. The patient unit using the wireless sensors which collect the physiological parameter which are (temperature, blood pressure, heartbeat, and oxygen saturation) and forward it to the hospital unit through the Radio Frequency (RF) module, The hospital unit receives the physiological data from the patient unit through the RF module and then the hospital server updates the database by the physiological data which is considered as connecting point between the system parts. The experiential tests of the system were applied to insure the accuracy and integrated linking between the medical environment and patient data. In addition, using this system will help the doctor continuously monitors the physiological signals of patients in real-time. The proposed system was developed simulated and successfully verified. The collected data, using such system, could be useful for further bio-statistical analysis.

Crop production variability in North and South America forced by life-cycles of the El Niño Southern Oscillation

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