Seabed seismic coupling - Testing and evaluation problems

Coupling of gravity deployed Ocean Bottom Seismometer multicomponent sensors has been an issue for at least 30 years, and remains largely an empirical art rather than a science. There are a number of reasons why it retains it elusive nature ;- the environment is generally hostile and all operations have to be conducted remotely, the nature of the seabed is highly variable from place to place, so that it is impossible to directly compare results from different sites, but largely because making detailed in-situ comparisons of a number of sensors accurately deployed in controlled deep sea conditions adjacent to each other is extremely costly. This paper considers some of these problems, and ways in which coupling can be evaluated in the laboratory, and the limitations that result. Variations of the internal sensor geometry also affect the sensor response in deployed sensors.Peer Reviewe

Cyber-Violence: Towards a Predictive Model, Drawing upon Genetics, Psychology and Neuroscience

The following paper outlines the latest incarnation of Owen’s (2014) evolving, meta-theoretical, Genetic-Social framework, and the intention is to illustrate the explanatory potential of the sensitizing device, in particular meta-constructs such as the biological variable (the evidence from behavioural genetics for an, at least in part, biological influence upon human behaviour), psychobiography (the unique, asocial, inherited aspects of the person such as disposition), and neuro-agency (a new term which acknowledges the influence of neurons upon human ‘free-will’), in the task of conceptualising cyber violence. In what follows, cyber violence is reconceptualised, moving the definition beyond the usual notion of gendered online violence towards a broader conception which incorporates hate trolling, cyber-terrorism, predatory online sexual ‘grooming’ and so on. It is the contention here that the synthesis ‘applied’ to cyber violence via flexible causal prediction may be of use to criminological theorists, social policy-makers and practitioners working in the field of the criminal justice in the task of constructing predictive models of cyber violence

Automated Magnetic Field Scanning System

One of Jefferson Laboratory’s research areas is in Superconducting Radio Frequency (SRF) science and technology. SRF cavities are tested in the Vertical Testing Area (VTA) at Jefferson Laboratory, within a series of large cylindrical dewars. The measured quality factor (Q factor) of the SRF cavity is directly influenced by any existing magnetic field. Because the VTA previously housed a cyclotron, all the rebars within the building have residual magnetic fields emanating from them. This magnetic field effect of the building renders the measurements of Q factor on the devices inaccurate and the testing data unreliable. A magnetic field scanning system must be employed to accurately map the magnetic field within the testing dewar so that an existing set of current-carrying coils installed around the dewar can be used properly for cancellation of the residual magnetic fields. This process will ensure the initial testing conditions are free of any unwanted magnetic fields that could cause unreliable testing data. The proposed system will scan the residual magnetic field inside vertical dewars of varying sizes (16”- 34” diameter by 72”- 132” depth) in three dimensions and log data for later use, as well as display a visual mapping of the data to the operator through LabView. A sensor with a sensitivity of at least 0.1 milligauss will be attached to the bottom of a long pole that will be lowered into the dewar. Translation in the z direction, on the dewar’s central axis, will be achieved by using a pair of stepper motors controlling a rack and pinion set up on the center pole. To achieve incremental mapping in the x-y plane, an arm will be attached to the bottom of the pole that will house additional sensors. The platform holding the stepper motors will turn on a dial with degree measurements, allowing for rotational movement of the entire center pole and arm. By calculating the x-y values for each sensor on the arm at that set degree amount, mapping of set increments in the x-y plane can be achieved.https://scholarscompass.vcu.edu/capstone/1036/thumbnail.jp

The 3.4 micron emission in comets

Emission features near 3.4 microns were detected in comet Bradfield (1987s) on 17 Nov. 1987 UT, and, marginally, on two earlier dates, with the Cooled Grating Array Spectrometer at the NASA Infrared Radio Telescope Facility (IRTF) (Brooke et al., 1988b). The central wavelength (3.36 microns) and width (approx. 0.15 microns) of the strongest feature coincide with those observed in comet Halley. A weaker emission feature at 3.52 microns and a strong feature extending shortward of 2.9 microns were also detected. This brings the number of comets in which these three features have been seen to three, two new (Bradfield, Wilson) and one old (Halley). It seems almost certain that the 3.4 micron features are emissions by C-H groups in complex molecules. Based on the similarity of the 3.4 micron features in comets Halley and Wilson, the authors suggest that a particular set of organic compounds may be common to all comets (Brooke et al. 1988a). The absence of the feature in some comets could then be due to photodestruction or evaporation of the organics when the comet approaches the sun, in combination with a predominance of thermal emission from non C-H emitting grains. Detection of the 3.4 micron emission feature in comet Bradfield at 4 = 0.9 AU provides support for this argument. Complex organics in comets could have been formed by particle irradiation of parent ices in the nucleus or been incorporated as grains at the time the comets formed. Since the most heavily irradiated layers of Halley would have been lost in its hundreds of perihelion passages, the authors believe the more likely explanation is that the 3.4 micron emitting material was incorporated in comet nuclei at the time of formation. The 3.4 micron comet feature resembles, but is not identical to, the interstellar 3.29 micron (and longer wavelength) emission features and the broad 3.4 micron feature seen in absorption toward the Galactic center. Detailed comparisons of cometary and interstellar organics will require comet spectra with signal-to-noise and spectral resolution comparable to that available in spectra of the interstellar medium. Such observations are currently being planned

Learning Needs, Barriers, Differences and Study Requirements: How Students Identify as ‘disabled’ in Higher Education

Higher educational institutions (HEIs) often categorise certain students as ‘disabled’ in order to support inclusive and equitable study. ‘Disabled’ students studying in higher education may be asked to ‘disclose a disability’, request and agree ‘reasonable adjustments’ that their institution will ‘provide’ them, and engage with processes such as applying for ‘Disabled Students’ Allowance’. However, there is little understanding of preferences and comfort with language in this area, and if students do not identify with terms such as ‘disabled’, this can create barriers to requesting or accessing support. This paper describes a qualitative study to investigate language preferences for common points of communication with the HEI. We held interviews and focus groups with students (n=12) and utilised discourse analysis to investigate the language used and student perceptions of language. We identified three distinct models of language used to discuss study needs relating to a ‘disability’, each with language norms and specific nomenclature. Furthermore, we found divergence in preferences in language, leading us to argue that differential and inclusive approaches to language use should be explored

Vapor Phase Oxidation of Chloropropenes Over Heterogeneous Catalyst Systems

Propylene Dichloride (PDC) is a byproduct of several Dow processes. The thermal cracking of PDC produces 1-cis-chloropropene, 1-trans-chloropropene, 2-chloropropene, and allyl chloride . By oxidizing the l- and 2-chloropropenes to 3- and 2- chloroacrylic acids, respectively, a potentially valuable product could be made. The chloropropenes, air, and steam were passed over various heterogeneous oxidation catalyst systems to attempt this oxidation. Contact time was varied between 0.0951 to 0.915 sec. Temperature was varied between 275C to .25C. The air content of the feed was varied between .1 to 75%. The chloropropene content of the feed was varied between 2.9% to 5.0% . The following supported catalysts were tested Co/Mo (3/7)-alumina pellets , CoMoO4-alumina granules, CoMo04-silica gel, AcNbMo-alumina pellets, two bed catalyst MoFeTeRe- MoVGeMo- silica gel, CoMoTe- silica gel, and CoMoBi-alumina pellets. No chloroacroleins, or chloroacrylic acids were detected in the reaction products. In general, no CO and from 5- 15% CO2 was obtained in the reaction products with the alumina and silica support materials. Oxidation over the metal catalysts produced 0-10% CO and 5-40% CO2. Severe carbonization of the supports with and without the metal catalysts was observed at the reaction conditions described above. Chloropropenes were found to be unstable, decomposing to carbon at 300°C in an empty reactor at a contact time greater than 0.1 sec. Chloroacrylic acids at a 0.1 sec contact time were tested in the reactor over alumina and silica support materials at 200°C and above, and found to be unstable with regard to decomposition to coke. It was concl uded that the vapor phase oxidation of chloropropenes over heterogeneous catalysts to chloroacrylic acids is not feasible because of their decomposition to car bon at the prevailing reaction conditions

Isolation of Unknown Genes from Human Bone Marrow by Differental Screening and Single-Pass cDNA Sequences Determination

A cDNA sequencing project was initiated to characterize gene expression in human bone marrow and develop strategies to isolate novel genes. Forty-eight random cDNAs from total human bone marrow were subjected to single-pass DNA sequence analysis to determine a limited complexity of mRNAs expressed in the bone marrow. Overall, 8 cDNAs (17%) showed no similarity to known sequences. Information from DNA sequence analysis was used to develop a differential prescreen to subtract unwanted cDNAs and to enrich for unknown cDNAs. Forty-eight cDNAs that were negative with a complex probe were subject to single-pass DNA sequence determination. Of these prescreened cDNAs, the number of unknown sequences increased to 23 (48%). Unknown cDNAs were also characterized by RNA expression analysis using 25 different human leukemic cell lines. Of 13 unknown cDNAs tested, 10 were expressed in all cell types tested and 3 revealed a hematopoietic lineage-restricted expression pattern. Interestingly, while a total of only 96 bone marrow cDNAs were sequenced, 31 of these cDNAs represent sequences from unknown genes and 12 showed significant similarities to sequences in the data bases. One cDNA revealed a significant similarity to a serine/threonine-protein kinase at the amino acid level (56% identity for 123 amino acids) and may represent a previously unknown kinase. Differential screening techniques coupled with single-pass cDNA sequence analysis may prove to be a powerful and simple technique to examine developmental gene expression