Analysis of Data Relevant to Establishing Outer Limits of a Continental Shelf under Law of the Sea Article 76

Coastal states may extend the limits of their juridically defined continental shelf beyond 200 nautical miles from their baselines under the provisions set forth in Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS). In a preparatory desktop study, the University of New Hampshire’s Center for Coastal and Ocean Mapping/Joint Hydrographic Center analysed existing U.S. bathymetric and geophysical data holdings, identified data adequacy, and survey requirements to prepare a U.S. claim beyond the Exclusive Economical Zone (EEZ). In this paper we describe the methodology for our desktop study with particular emphasis on how we assembled and evaluated the existing data around the shelf areas of the United States, and estimated where additional surveys may be required

Error Estimation of Bathymetric Grid Models Derived from Historic and Contemporary Data Sets

The past century has seen remarkable advances in technologies associated with positioning and the measurement of depth. Lead lines have given way to single beam echo sounders, which in turn are being replaced by multibeam sonars and other means of remotely and rapidly collecting dense bathymetric datasets. Sextants were replaced by radio navigation, then transit satellite, GPS and now differential GPS. With each new advance comes tremendous improvement in the accuracy and resolution of the data we collect. Given these changes and given the vastness of the ocean areas we must map, the charts we produce are mainly compilations of multiple data sets collected over many years and representing a range of technologies. Yet despite our knowledge that the accuracy of the various technologies differs, our compilations have traditionally treated each sounding with equal weight. We address these issues in the context of generating regularly spaced grids containing bathymetric values. Gridded products are required for a number of earth sciences studies and for generating the grid we are often forced to use a complex interpolation scheme due to the sparseness and irregularity of the input data points. Consequently, we are faced with the difficult task of assessing the confidence that we can assign to the final grid product, a task that is not usually addressed in most bathymetric compilations. Traditionally the hydrographic community has considered each sounding equally accurate and there has been no error evaluation of the bathymetric end product. This has important implications for use of the gridded bathymetry, especially when it is used for generating further scientific interpretations. In this paper we approach the problem of assessing the confidence of the final bathymetry gridded product via a direct-simulation Monte Carlo method. We start with a small subset of data from the International Bathymetric Chart of the Arctic Ocean (IBCAO) grid model [Jakobsson et al., 2000]. This grid is compiled from a mixture of data sources ranging from single beam soundings with available metadata, to spot soundings with no available metadata, to digitized contours; the test dataset shows examples of all of these types. From this database, we assign a priori error variances based on available meta-data, and when this is not available, based on a worst-case scenario in an essentially heuristic manner. We then generate a number of synthetic datasets by randomly perturbing the base data using normally distributed random variates, scaled according to the predicted error model. These datasets are next re-gridded using the same methodology as the original product, generating a set of plausible grid models of the regional bathymetry that we can use for standard deviation estimates. Finally, we repeat the entire random estimation process and analyze each run’s standard deviation grids in order to examine sampling bias and standard error in the predictions. The final products of the estimation are a collection of standard deviation grids, which we combine with the source data density in order to create a grid that contains information about the bathymetric model’s reliability

Microbial fuel cell-based biosensors for estimation of biochemical oxygen demand and detection of toxicity

PhD ThesisThere is a global requirement to establish state-of-the-art monitoring techniques for analysis of water quality to ensure that standards are maintained with increasing domestic and industrial water usage. An important parameter used in water quality assessment is Biochemical Oxygen Demand (BOD), a measurement of the oxygen consumed by micro-organisms in the oxidation of biodegradable organic material. BOD measurements have been correlated with the output from Microbial Fuel Cells (MFCs), which are a potential solution for online monitoring of wastewaters. Previously studied MFC sensors have had a limited amperometric range of approximately 250 mg/l O2 BOD5; which is often attributed to substrate saturation of the anode biofilm. In this work, a proof-of-concept configuration of multi-stage MFCs connected hydraulically in series was tested extensively to eliminate the saturation effect and extend the sensing range. The summed current generated by a three-stage array was calibrated against BOD5 for different glucose-glutamic acid concentrations in artificial wastewater. A linear response was obtained up to approximately 750 mg/l O2 BOD5 with R2 > 99% and average standard deviation < 9%. The array range was three times greater than obtained with the first MFC operating individually. Batch-mode sensors were also operated to develop greater understanding of the long-term performance characteristics and establish how changes in operating parameters affect sensor calibration. Additionally, the effect of toxicant presence (4-nitrophenol) on the multi-stage sensor response was studied. Toxic and low BOD events which both resulted in current decreases could be differentiated using the MFC-based sensor. The modular mode of operation permitted highstrength BOD wastewaters to be measured online without dilution and an explicit differentiation between toxic and low BOD events based on the ordered response of MFCs. The MFC-based sensors were tested with samples of real influent wastewater and recommendations have been made for ‘best practice’ operation and calibration of MFC sensors

An update on χc\chi_c Decays: Perturbative QCD versus Data

We present a global fit of current available experimental results on $\chi_c$ decays within next-to-leading-order perturbative QCD. The quality and reduced errors of recent data improve the agreement between theory and experiment.Comment: 10 pages, Late

Speaking up in resource-constrained settings: how to secure safe surgical care in the moment and in the future?

No description supplie

On the Use of Historical Bathymetric Data to Determine Changes in Bathymetry: An Analysis of Errors and Application to Great Bay Estuary, NH

The depth measurements that are incorporated into bathymetric charts have associated errors with magnitudes depending on the survey circumstances and applied techniques. For this reason, combining and comparing depth measurements collected over many years with different techniques and standards is a difficult task which must be done with great caution. In this study we have developed an approach for comparing historical bathymetric surveys. Our methodology uses Monte Carlo modelling to account for the random error components inherited in the data due to positioning and depth measurement uncertainties

Analysis of Data Relevant to Establishing Outer Limits of a Continental Shelf under Law of the Sea Article 76

Coastal states may extend the limits of their juridically defined continental shelf beyond 200 nautical miles from their baselines under the provisions set forth in Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS). In a preparatory desktop study, the University of New Hampshire’s Center for Coastal and Ocean Mapping/Joint Hydrographic Center analysed existing U.S. bathymetric and geophysical data holdings, identified data adequacy, and survey requirements to prepare a U.S. claim beyond the Exclusive Economical Zone (EEZ). In this paper we describe the methodology for our desktop study with particular emphasis on how we assembled and evaluated the existing data around the shelf areas of the United States, and estimated where additional surveys may be required

GPS Vulnerabilities and Implications for Telecom

Aerospace Engineering and Engineering Mechanic

Detecting Circumbinary Exoplanets: Understanding Transit Timing

We have derived and tested a simple analytical model for placing limits on the transit timing variations of circumbinary exoplanets. These are generally of days in magnitude, dwarfing those found in multi-planet systems. The derived method is fast, efficient and is accurate to approximately 1% in predicting limits on the possible times of transits over a 3-year campaig