Frio brine sequestration pilot in the Texas Gulf Coast

A field experiment to pioneer CO2 injection for sequestration in a brine-bearing sandstone-shale sequence in the Texas Gulf Coast, USA, is in the preinjection modeling and planning phase. Innovations in this experiment include (1) CO2 injection into high-volume highpermeability rocks that have storage capacity sufficient to impact greenhouse gas emissions, (2) injection into a setting lacking the complications introduced by hydrocarbons and perturbations resulting from production and secondary recovery, and (3) intensive pre-, syn-, and post-injection monitoring and modeling for validation of the effectiveness of sequestration. The experiment is designed to provide a rapid increase in information from a small-volume and short-duration injection.Bureau of Economic Geolog

Thermoelectric energy harvester with a cold start of 0.6 °C

This paper presents the electrical and thermal design of a thermoelectric energy harvester power system and its characterisation. The energy harvester is powered by a single Thermoelectric Generator (TEG) of 449 couples connected via a power conditioning circuit to an embedded processor. The aim of the work presented in this paper is to experimentally confirm the lowest ΔT measured across the TEG (ΔTTEG) at which the embedded processor operates to allow for wireless communication. The results show that when a temperature difference of 0.6 °CΔTTEG is applied across the thermoelectric module, an input voltage of 23 mV is generated which is sufficient to activate the energy harvester in approximately 3 minutes. An experimental setup able to accurately maintain and measure very low temperatures is described and the electrical power generated by the TEG at these temperatures is also described. It was found that the energy harvester power system can deliver up to 30 mA of current at 2.2 V in 3ms pulses for over a second. This is sufficient for wireless broadcast, communication and powering of other sensor devices. The successful operation of the wireless harvester at such low temperature gradients offers many new application areas for the system, including those powered by environmental sources and body heat

The reduction of the effect of the Muller-Lyer illusion on saccade amplitude by classic adaptation

The effect of Müller-Lyer stimuli on saccade amplitude varies across studies. One methodological difference between studies is stimulus display time; studies with long stimulus display times tend to report smaller effects than studies with short display times. Is it possible that long display times might provide conditions in which saccade adaption takes place? Five adult subjects were exposed to runs of the same illusion-inducing Müller-Lyer stimulus, presented for 1 s, interspersed with probe trials in which a point target was presented for 200 ms. While saccade amplitude was consistently larger with ‘in-configurations’ than with ‘out-configurations’ at the beginning of runs, amplitude declined over runs with the in-configuration. On average, it was constant in out-configuration runs. The net effect was a decline in the apparent effect size (in-amp − out-amp / out-amp) of the Müller-Lyer stimulus. Probe trial saccade amplitude increased in ‘out’ runs and decreased in ‘in’ runs. These effects were not present in control experiments, in which stimulus display time was 200 ms. One explanation for this pattern of results is that long stimulus presentation times allow for the generation of retinal error signals. This in turn leads to saccade adaptation, causing an underestimation of the effect of this type of stimulus on saccade amplitude

Statocyst, Input, Multimodal Interactions, and Their Effects on Motor Outputs in the Norway Lobster, Nephrops norvegicus (L.)

The statocyst organ in Decapod crustaceans detects body tilt. It is a powerful input to various equilibrium pathways. A range of techniques have been used to study the transmission of statocyst information and the effects of this information on thoracic and abdominal motor systems in Nephrops novegicus . Interneurons carrying information from the statocysts were recorded in the circumoesophageal connectives. Three different types of interneuron were recorded; of these, one responded best to tilt in the roll plane, while the other two responded best to tilt in the pitch plane but with apposite polarities. Combinations of pitch and roll, produced responses in these interneurons which, while maintaining the same phase position, decreased in size as the preparation was moved out of the preferred plane of tilt. These interneurons showed little or no response to various types of leg stimulation. The responses of intact animals to body tilt were investigated by tilting animals in a large seawater tank; responses were recorded on videotape. Tilt in the roll plane produced a range of responses, the most prominent of which was an asymmetric leg response. Legs on the lowered side cycled in a patterned manner while legs on the raised side were held in a protracted and levated position. This response is distinct from previously reported patterns of leg activity such as walking and "waving". After leg autotomy, this pattern of leg activity was abolished. Coordination was found between the cycling of the legs and the beating of the swimmerets during tilt in the roll plane. This was compared with the coordination between legs and swimmerets during walking. Tilts in the pitch plane resulted in systematic alterations of abdominal posture. Head-down tilt produced a marked abdominal flexion and head-up tilt produced extension. An examination of the responses of swimmerets to tilt in this plane showed that the angle of the powerstroke during head-down tilt was intermediate between the laterally directed powerstroke seen during tilt in the roll plane, and the rearward beat seen during head-up tilt. Recordings made in the swimmeret system revealed at least one tonically active returnstroke motoneuron which received input from the statocysts. Pitching the preparation head down caused an increase of firing frequency in this unit. This unit has been anatomically and physiologically identified as one of the returnstroke motoneurons. Recordings made from the slow abdominal flexor motoneurons revealed a sensitivity to tilt in the pitch plane. However, they responded in an opposite manner to the tonic returnstroke unit. The peripheral inhibitor to this muscle was also recorded. It fired in phase with the tonic returnstroke unit. Interactions between statocysts, legs and swimmerets were investigated at the behavioural level. Substrate contact prevented expression of asymmetric swimmeret responses to roll. However it was possible to demonstrate that this effect is not due to physical contact between the substrate and the terminal segment of the leg, the dactylopodite. In the absence of substrate contact, swimmeret beating was nevertheless inhibited when leg cycling was prevented by blocking leg movement at the proximal joints. Blocking leg movement on one side of the body was sufficient to suppress the swimmeret responses on both sides. In conclusion, information from the statocysts is carried by unimodal interneurons. This information is available to both the swimmerets and the abdominal pasture system. In the absence of swimmeret beating, statocyst information continues to reach the swimmeret system where it determines the output of a tonic returnstroke motoneuron. Substrate contact radically alters the effect of statocyst input. This finding poses specific questions as to the precise nature of the interaction between descending statocyst information, leg input and output patterns, and the swimmeret and abdominal posture motor systems. This may be an ideal system for investigating interactions between the pattern generators of two different systems, specifically the legs and swimmerets, and the role of different types of sensory input in these systems

Experimental and Numerical Investigation of Thermal Performance of a Crossed Compound Parabolic Concentrator with PV Cell

Crossed compound parabolic concentrator (CCPC) is a solar energy device used to increase the photovoltaic (PV) cell electrical power output. CCPC’s thermal and optical performance issues are equally important for a PV cell or module to work under a favourable operating condition. However, most work to-date is emphasised on its optical performance paying a little attention to the thermal characteristics. In this contribution, we investigate the thermal performance of a CCPC with PV cell at four different beam incidences (0o, 10o, 20o, 30o and 40o). Initially, experiment is performed in the indoor PV laboratory at the University of Exeter with 1kW/m2 radiation intensity. 3D simulations are carried out to first validate the predicted data and then to characterise the overall performance. Results show that the temperature in the PV silicon layer is the highest at 0o and 30o, with the top glass cover of CCPC having the lowest temperature at all the incidences. The temperature and optical efficiency profiles at the various incidences predicted by simulation show very good agreement with the measurements, especially at 0o incidence. This study provides useful information for understanding the coupled optical-thermal performance of the CCPC with PV cell working at various conditions

Natural convective heat transfer in a walled CCPC with PV cell

The free convective heat transfer phenomenon in an isolated, walled CCPC with PV cell is studied experimentally at 1000 W/m2 irradiance and 28.5 °C ambient temperature as well as 0°, 10°, 20°, 30° and 40° incidences in indoor laboratory by using solar simulator. Then a series of numerical simulations are launched to estimate the CCPC natural heat transfer behaviour and optical performance based on steady heat transfer and laminar flow models with grey optical option. It is identified that the heat transfer and optical performances of CCPC are dependent on the incidence. Especially, the PV cell is subject to the highest temperature at an incidence less than 20°, and otherwise the top glass cover is with the highest temperature. The predicted temperatures, Nusselt numbers and heat loss ratios are consistent with the experimental observations basically, especially at the incidence less than 20° with (−10.1~+3) % error in temperature, (−35.6~+12.6) % in Nusselt number, and (−1.2~+20.5) % in CCPC wall heat loss ratio. The optical parameters predicted agree very well with the measurements. The heat loss from the CCPC walls accounts for nearly 60% of the total incoming solar irradiance and should be paid significant attention in the design of CCPC

Temporal stability and training effects in "express saccade makers"

A gap between fixation target offset and saccade target onset encourages the production of express saccades (ES; latency 80-130ms). “Express saccade makers” (ESMs) produce almost exclusively ES in gap trials, and in overlap trials (fixation target present when the saccade target appears), a large proportion (>30%) of their saccades are ES. We investigated performance stability in ESM and nonESM participants over time and the effect of repeated exposure to gap and overlap tasks. Experiment 1. 113 participants (59 ESMs) completed two blocks of 200 overlap trials in the first session (T1). Sixty provided data on a second occasion (T2; 27 ESMs; 200 trials; mean of 87 days later) and 30 provided data on a third occasion (T3; 13 ESMs; 200 trials; mean of 94 days later). Eye movements were recorded using an infrared reflectance eye tracker. For each participant, the percentage of saccades with latencies of 80ms to 130ms (%ES) was calculated for all saccades with latencies between 50ms and 500ms. Participants displayed the same relative performance both within (T1, Block 1 vs 2: ICC=0.97,

The Review of Public Administration

As the outcomes of the Review of Public Administration emerge, this chapter attempts three things. First, we consider the detail of the review process – its inception, aims and consultation processes. Second, we describe the existing system of public administration and examine the responses of the main sectors, local government, non-departmental public bodies, and government agencies to proposals for change. Third, we set out the outcomes of the review and the likely consequences for public service delivery in Northern Irelan

Bureau Shuffling? The Review of Public Administration in Northern Ireland

The Belfast (Good Friday) Agreement 1998 resulted in the return of devolved government to Northern Ireland and, with it, a decision by the Executive and Assembly to conduct a radical review of public administration. As the review reaches its final stages this paper considers the likely outcomes. It argues that the parameters of the review will limit its impact and describes the reform proposals as structural changes or administrative rationalisation, devoid of a wider modernising approach to improving public services. The on/off nature of devolution could result in ‘one of the major tasks for devolved government’ (according to the Northern Ireland Executive) being implemented by Direct Rule minister