Simulation assessment of the direct-push permeameter for characterizing vertical variations in hydraulic conductivity

This is the published version. Copyright American Geophysical Union[1] The direct-push permeameter (DPP) is a tool for the in situ characterization of hydraulic conductivity (K) in shallow, unconsolidated formations. This device, which consists of a short screened section with a pair of pressure transducers near the screen, is advanced into the subsurface with direct-push technology. K is determined through a series of injection tests conducted between advancements. Recent field work by Butler et al. (2007) has shown that the DPP holds great potential for describing vertical variations in K at an unprecedented level of detail, accuracy and speed. In this paper, the fundamental efficacy of the DPP is evaluated through a series of numerical simulations. These simulations demonstrate that the DPP can provide accurate K information under conditions commonly faced in the field. A single DPP test provides an effective K for the domain immediately surrounding the interval between the injection screen and the most distant pressure transducer. Features that are thinner than that interval can be quantified by reducing the vertical distance between successive tests and analyzing the data from all tests simultaneously. A particular advantage of the DPP is that, unlike most other single borehole techniques, a low-K skin or a clogged screen has a minimal impact on the K estimate. In addition, the requirement that only steady-shape conditions be attained allows for a dramatic reduction in the time required for each injection test

Pumping tests in networks of multilevel sampling wells: Motivation and methodology

This is the published version. Copyright American Geophysical UnionThe identification of spatial variations in hydraulic conductivity (K) on a scale of relevance for transport investigations has proven to be a considerable challenge. Recently, a new field method for the estimation of interwell variations in K has been proposed. This method, hydraulic tomography, essentially consists of a series of short-term pumping tests performed in a tomographic-like arrangement. In order to fully realize the potential of this approach, information about lateral and vertical variations in pumping-induced head changes (drawdown) is required with detail that has previously been unobtainable in the field. Pumping tests performed in networks of multilevel sampling (MLS) wells can provide data of the needed density if drawdown can accurately and rapidly be measured in the small-diameter tubing used in such wells. Field and laboratory experiments show that accurate transient drawdown data can be obtained in the small-diameter MLS tubing either directly with miniature fiber-optic pressure sensors or indirectly using air-pressure transducers. As with data from many types of hydraulic tests, the quality of drawdown measurements from MLS tubing is quite dependent on the effectiveness of well development activities. Since MLS ports of the standard design are prone to clogging and are difficult to develop, alternate designs are necessary to ensure accurate drawdown measurements. Initial field experiments indicate that drawdown measurements obtained from pumping tests performed in MLS networks have considerable potential for providing valuable information about spatial variations in hydraulic conductivity

Evaluation Protocol: Speech Bubbles

The Speech Bubbles intervention aims to improve children’s communication and social skills by providing them with weekly creative drama sessions. The benefit to pupils’ communication skills is also thought to have an effect on pupils’ reading skills. This is an intervention targeted at pupils with below expected communication and social skills. During the sessions trained practitioners encourage children to tell, act out and reflect on their own stories by creating a safe and playful environment, promoting children’s communication, confidence and wellbeing. This is based on the Helicopter Stories pedagogical approach.1 Speech Bubbles is part of a broader programme of work entitled ‘Learning about Culture’, which aims to improve the evidence base around arts-based education programmes. This is coordinated by the Education Endowment Foundation and the Royal Society for the Arts.2 It consists of five programmes: two in Key Stage 1 (Reception and Year 1) and three in Key Stage 2 (Year 5). Despite the unique aspects of these intervention models, there are many similarities in how they are delivered and what they hope to achieve.

Steady shape analysis of tomographic pumping tests for characterization of aquifer heterogeneities

This is the published version. Copyright American Geophysical Union[1] Hydraulic tomography, a procedure involving the performance of a suite of pumping tests in a tomographic format, provides information about variations in hydraulic conductivity at a level of detail not obtainable with traditional well tests. However, analysis of transient data from such a suite of pumping tests represents a substantial computational burden. Although steady state responses can be analyzed to reduce this computational burden significantly, the time required to reach steady state will often be too long for practical applications of the tomography concept. In addition, uncertainty regarding the mechanisms driving the system to steady state can propagate to adversely impact the resulting hydraulic conductivity estimates. These disadvantages of a steady state analysis can be overcome by exploiting the simplifications possible under the steady shape flow regime. At steady shape conditions, drawdown varies with time but the hydraulic gradient does not. Thus transient data can be analyzed with the computational efficiency of a steady state model. In this study, we demonstrate the value of the steady shape concept for inversion of hydraulic tomography data and investigate its robustness with respect to improperly specified boundary conditions

Synthetic Methods of CTS and CZTS Nanocrystals

The synthesis of various morphologies of copper zinc tin sulfide (Cu2ZnSnS4) and copper tin sulfide (Cu2SnS3) nanocrystals were explored to find a more energy efficient synthesis. Reactions were all carried out at 220°C under either inert atmospheres or normal conditions. Variations in synthetic methods included reaction time and solvents used. Products were analyzed with powder X-Ray diffraction and compared to simulated powder patterns of zincblende and wurtzite nanocrystals. The synthesis of CTS nanocrystals required the reaction to be heated to 220°C overnight under an inert atmosphere. The reaction used for the synthesis of CZTS nanocrystals required less energy and only required the reaction to be heated to 220°C for four hours. The effects of solvents were found to be that 1-octadecene (ODE) yielded predominantly a zincblende morphology, oleylamine (OAm) yielded predominantly a Wurtzite morphology, and the use of 1-dodecanethiol (DDT) as the only solvent yielded a mixture of zincblende and Wurtzite nanocrystals. The various nanocrystals produced assisted in achieving our overall goal by narrowing down an energy efficient and effective synthesis of CZTS and CTS nanocrystals using earth-abundant and low cost reagents.https://digitalcommons.morris.umn.edu/urs_2015/1001/thumbnail.jp

Evaluation Protocol: First Thing Music

The First Thing Music programme aims to improve children’s reading and social skills by providing them with daily music sessions. The sessions are part of a structured music education programme based on the Kodály approach. Students will learn the basics of music through daily singing and musical games with teachers who will be trained by music practitioners. Music education has been linked to improvements in academic attainment in areas such as literacy and language.1 First Thing Music is part of a broader programme of work entitled ‘Learning About Culture’, which aims to improve the evidence base around arts-based education programmes. This is coordinated by the Education Endowment Foundation and the Royal Society for the Encouragement of Arts, Manufactures and Commerce.2 It consists of five programmes: two in Key Stage 1 and three in Key Stage 2