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Prediction of the amount of water that may seep into the waste emplacement drifts is an important aspect of assessing the performance of the proposed geologic nuclear waste repository at Yucca Mountain, Nevada. The repository is to be located in thick, partially saturated fractured tuff that will be heated to above-boiling temperatures as a result of heat generation from the decay of nuclear waste. Since water percolating down towards the repository will be subject to vigorous boiling for a significant time period, the superheated rock zone (i.e., rock temperature above the boiling point of water) can form an effective vaporization barrier that reduces the possibility of water arrival at emplacement drifts. In this paper, we analyze the behavior of episodic preferential flow events that penetrate the hot fractured rock, and we evaluate the impact of such flow behavior on the effectiveness of the vaporization barrier.

Understanding thermally driven coupled hydrological, mechanical, and chemical processes in unsaturated fractured tuff is essential for evaluating the performance of the potential radioactive waste repository at Yucca Mountain, Nevada. The Drift Scale Test (DST), intended for acquiring such an understanding of these processes, has generated a huge volume of temperature and moisture redistribution data. Sophisticated thermal hydrological (TH) conceptual models have yielded a good fit between simulation results and those measured data. However, some uncertainties in understanding the TH processes associated with the DST still exist. This paper evaluates these uncertainties and provides quantitative estimates of the range of these uncertainties. Of particular interest for the DST are the uncertainties resulting from the unmonitored loss of vapor through an open bulkhead of the test. There was concern that the outcome from the test might have been significantly altered by these losses. Using alternative conceptual models, we illustrate that predicted mean temperatures from the DST are within 1 degree C of the measured mean temperatures through the first two years of heating. The simulated spatial and temporal evolution of drying and condensation fronts is found to be qualitatively consistent with measured saturation data. Energy and mass balance computation shows that no more than 13 percent of the input energy is lost because of vapor leaving the test domain through the bulkhead. The change in average saturation in fractures is also relatively small. For a hypothetical situation in which no vapor is allowed to exit through the bulkhead, the simulated average fracture saturation is not qualitatively different enough to be discerned by measured moisture redistribution data. This leads us to conclude that the DST, despite the uncertainties associated with open field testing, has provided an excellent understanding of the TH processes.

The synthesis and characterization of a series of adamantane-shaped [Mn4O6](super 4+) complexes is reported. A comparison of spectroscopic and redox properties is presented as well as X-ray structure determinations for two members of the series.

A study is conducted towards the synthesis and characterization of Mn-oxo complexes to understand the structural and physicochemical properties of the WO site in PSII. A major emphasis is put towards complexes that had direct or indirect relevance to the PSII Mn (sub 4) site.

Photoplethysmography (PPG) signal quality assessment (SQA) ensures improved measurements of various surrogate cardiovascular measurements like heart rate, SpO2, blood pressure, cardiac output and many more and as well reduces false alrams in ambulatory measurements. Although PPG SQA (PSQA) is a well researched area, but multiclass prediction of signal quality and its hardware implementation is limited. In this paper, a new non-segmenting approach for multiclass PSQA is presented with an optimal set of seven time-frequency domain features in conjuction with supervised classifiers to identify clean, partly clean and corrupted PPG data. The present work was carried out in three major stages- signal (dataset) acquisition, feature extraction and 3-class classification using random forest classifier. The technique was evaluated with volunteers’ data, MIMIC-III data from PhysioNet, CSL data, and combined data and achieved an overall average accuracy of 96.8% with good (0.98 or above) sensitivity, specificity, F1 score, precision and recall. On-device implementation of the proposed PSQA was accomplished using 7.2 h of PPG dataset on a quad-core Broadcom BCM 2837 controller with 1.2 GHz, supported by 1 GB RAM-based standalone device, with an accuracy of 97.09%. The latency and the peak memory requirement of the implementation was 0.81 s and 19 kB respectively to process 3 s PPG data. The present technique may be integrated as a part of a remote healthcare system using wearable sensors. [ABSTRACT FROM AUTHOR]

Redox behavior of the oxo-bridged tetramanganese complex [Mn4O6(bpea)(sub 4)](super 4+), which retains its adamantane-type core structure upon reduction by one electron is reported. The work described raises the possibility of 'shape shifting' for the PSII Mn(sub 4) cluster.

AbstractAutomated and early detection of diabetics with polyneuropathy in an ambulatory health monitoring setup may reduce the major risk factors for diabetic patients. Increased and localized plantar pressure associated with impaired pain and temperature is a combination of developing foot ulcers in subjects with polyneuropathy. Although many interesting research works have been reported in this area, most of them emphasize on signal acquisition process and plantar pressure distribution in the foot region. In this work, a machine learning assisted low complexity technique was developed using plantar pressure and temperature signals which will classify between diabetic polyneuropathy and healthy subjects. Principal component analysis (PCA) and maximum relevance minimum redundancy (mRMR) methods were used for feature extraction and selection respectively followed by k-NN classifier for binary classification. The proposed technique was evaluated with 100 min of publicly available annotated data from 43 subjects and provides blind test accuracy, sensitivity, precision, F1-score, and area under curve (AUC) of 99.58%, 99.50%, 99.44%, 99.47% and 99.56% respectively. A low resource hardware implementation in ARM v6 controller required an average memory usage of 81.2 kB and latency of 1.31 s to process 9 s pressure and temperature data collected from 16 sensor channels for each of the foot region. [ABSTRACT FROM AUTHOR]

The copper coordination chemistry of two phthalazine-based ligands of differing steric bulk is investigated. The different chemical and electronic behavior highlights the influence of a hydrophobic binding pocket on the stability and reactivity of the dicopper(I) centers.

A new class of oxo-bridged high-valent hexamanganese clusters containing a novel {Mn6O8}(super 6+) core where two Mn3O4 cuboidal units are joined through two 'T-shaped' oxo bridge is synthesized and their structure and physical properties are investigated.

Multidentate naphthyridine-based ligands were used to prepare a series of diiron(II) complexes. The Mossbauer spectroscopic properties of diiron(II) complexes are investigated.

The synthesis of a bis-mu-oxo, bis-mu-carboxylato Mn2(III,IV) complex supported by a sterically hindered carboxylate ligand is addressed. Results show that placing methyl groups at the 4,4E positions of the bpy ligand causes a severe steric perturbation, primarily at the Mn(super IV) center, causing a destabilization of the dinuclear core, causing it to convert to an Mn6 species.