Direct Push Research Articles

“A brain to pick, an ear to listen and a push in the right direction” (John C. Crosby)

This paper provides the context and background to a ‘Student Peer Mentoring’ scheme that was co-created with students and piloted within the Business Faculty in University of Greenwich. We reflect on sharing this experience at the annual SHIFT1 conference on Teaching, Learning and Assessment and the lessons learned that will support the further development of this scheme. Key themes that arose were around the value of mentoring to support first year students and the benefit for mentors in terms of their own self confidence and development as evidenced by their contribution to SHIFT. Lessons learnt were the need to provide more guidance to mentees in preparation for mentoring and providing supervision support to mentors to allow them to reflect on issues that arise out of mentoring. Our complex approach to evaluation was challenged given the small numbers of numbers of mentors and mentees. We concluded that qualitative evidence gives enough support for the success of this scheme. It is planned to provide mentor training to all students on a voluntary basis leading to enhanced peer relationships and support.

Direct Push Video Imaging: An Innovation in Prehistoric Paleolandscape Survey

– Direct push video imaging maps buried prehistoric landscapes in soft geology. – Subtle subsoil variability is detectable through a combination with CPT-E and EC logs. – Validation remains crucial pending color calibration- and hardware improvements.

Machine learning based approach for the interpretation of engineering geophysical sounding logs

In this paper, a set of machine learning (ML) tools is applied to estimate the water saturation of shallow unconsolidated sediments at the Bátaapáti site in Hungary. Water saturation is directly calculated from the first factor extracted from a set of direct push logs by factor analysis. The dataset observed by engineering geophysical sounding tools as special variants of direct-push probes contains data from a total of 12 shallow penetration holes. Both one- and two-dimensional applications of the suggested method are presented. To improve the performance of factor analysis, particle swarm optimization (PSO) is applied to give a globally optimized estimate for the factor scores. Furthermore, by a hyperparameter estimation approach, some control parameters of the utilized PSO algorithm are automatically estimated by simulated annealing (SA) to ensure the convergence of the procedure. The result of the suggested ML-based log analysis method is compared and verified by an independent inversion estimate. The study shows that the PSO-based factor analysis aided by hyperparameter estimation provides reliable in situ estimates of water saturation, which may improve the solution of environmental end engineering problems in shallow unconsolidated heterogeneous formations.

Shifting Perceptions of CRISPR

Shifting Perceptions of CRISPR

Chemical-mediated translocation in protocell-based microactuators

Artificial cell-like communities participate in diverse modes of chemical interaction but exhibit minimal interfacing with their local environment. Here we develop an interactive microsystem based on the immobilization of a population of enzyme-active semipermeable proteinosomes within a helical hydrogel filament to implement signal-induced movement. We attach large single-polynucleotide/peptide microcapsules at one or both ends of the helical protocell filament to produce free-standing soft microactuators that sense and process chemical signals to perform mechanical work. Different modes of translocation are achieved by synergistic or antagonistic enzyme reactions located within the helical connector or inside the attached microcapsule loads. Mounting the microactuators on a ratchet-like surface produces a directional push-pull movement. Our methodology opens up a route to protocell-based chemical systems capable of utilizing mechanical work and provides a step towards the engineering of soft microscale objects with increased levels of operational autonomy.

The in situ treatment of Basic Violet 16 synthetic dye in groundwater

AbstractSynthetic dyes have been shown to be micropollutants in various aquatic and groundwater systems, often occurring at milligram per liter (mg/L) concentrations. Synthetic dyes are typically introduced into the environment either as a continuous stream from wastewater or as episodic events related to the disposal of residues or spills generated during the manufacturing process. Various studies for the treatment of synthetic dyes have been undertaken for wastewater but studies for the in situ treatment of synthetic dyes in groundwater are limited. A pilot‐scale test was conducted to determine if the use of colloidal activated carbon (CAC) could effectively reduce dissolved concentrations of the synthetic dye Basic Violet (BV16) in groundwater using in situ methods. The pilot test was carried out downgradient of a textile manufacturing facility where historic disposal practices resulted in the release of various chemicals of concern including BV16 to an unconfined silty sand aquifer. A 10‐weight percent CAC solution was injected into a series of temporary direct push injection points to target the synthetic dye that was present at concentrations of up to 1,640 micrograms per liter (μg/L) during the 738‐day study. The results from the pilot test indicated that the CAC was effectively delivered to the target injection zone resulting in a three order of magnitude increase in total organic carbon (TOC) concentrations compared to preinjection TOC concentrations within the aquifer. Distribution of the CAC within the targeted injection zone indicated that heterogeneity affected the distribution with a zone of higher horizontal hydraulic conductivity (KH) having an average TOC concentration approximately 100 percent greater than the mean TOC concentration within the surrounding aquifer targeted by the CAC injection. Analyses of the groundwater chemistry before and postinjection indicated that the CAC had no detrimental impact on the groundwater quality while reducing the concentration of dissolved BV16 within the plume to below the method detection limits within 62 days of injection. The concentration of BV16 remained below the method detection limit of 10 µg/L for the 738‐day duration of the study apart from one detection of 180 µg/L at Day 183 within groundwater sampled from one monitoring well suggesting that the CAC was effective in attenuating the BV16 over the short and moderate term.

Investigation into Effect of Sonic Drilling Methodology on Standard Penetration Test Results in Dense Sand

Abstract An extensive field investigation was conducted to quantify the variation between drilling methodologies on the SPT outputs (SPT-N60 values) in dense saturated sands. For this experiment, a test site with reasonably consistent soil properties was identified, where multiple standard penetration tests (SPTs) were conducted using four drilling methodologies, including rotary core, direct push, and two sonic drilling methods. Considering the rotary core as the benchmark, the SPT-N values obtained from this method were systematically compared with those from the other three drilling methodologies. For the dense saturated sands studied in this research, the SPT-N values from rotary sonic DT-45 showed the closest correlation to the SPT-N values from the rotary core, with about 15% variation. The variation was shown not to be statistically significant, considering the inherent variability of the SPT and the measured confidence interval of the SPT-N values from the standard rotary core method.

A Comparison of Six Transport Models of the MADE-1 Experiment Implemented With Different Types of Hydraulic Data.

Six conceptually different transport models were applied to the macrodispersion experiment (MADE)‐1 field tracer experiment as a first major attempt for model comparison. The objective was to show that complex mass distributions in heterogeneous aquifers can be predicted without calibration of transport parameters, solely making use of structural and flow data. The models differ in their conceptualization of the heterogeneous aquifer structure, computational complexity, and use of conductivity data obtained from various observation methods (direct push injection logging, DPIL, grain size analysis, pumping tests and flowmeter). They share the same underlying physical transport process of advection by the velocity field solely. Predictive capability is assessed by comparing results to observed longitudinal mass distributions of the MADE‐1 experiment. The decreasing mass recovery of the observed plume is attributed to sampling and no physical process like mass transfer is invoked by the models. Measures like peak location and strength are used in comparing the modeled and measured plume mass distribution. Comparison of models reveals that the predictions of the solute plume agree reasonably well with observations, if the models are underlain by a few parameters of close values: mean velocity, a parameter reflecting log‐conductivity variability, and a horizontal length scale related to conductivity spatial correlation. The robustness of the results implies that conservative transport models with appropriate conductivity upscaling strategies of various observation data provide reasonable predictions of plumes longitudinal mass distribution, as long as key features are taken into account.

The effects of hydraulic/pneumatic fracturing-enhanced remediation (FRAC-IN) at a site contaminated by chlorinated ethenes: A case study

A low-permeability locality with heterogeneous geology contaminated primarily by tetrachloroethene (PCE) present partially in the free phase in the unsaturated zone was treated on a pilot scale via direct push pneumatic fracturing combined with the hydraulic delivery of a remediation suspension consisting of milled iron, sulphidated nanosized zerovalent iron and sand in guar gum solution. Afterwards, a whey solution was injected into the fractures as a carbon source for bacteria. The unsaturated and saturated zones were treated. Long-term monitoring of the groundwater revealed that the abiotic reduction of PCE and trichloroethene was the dominant remediation processes for several months after the injections. A complex microbial consortium was developed that was capable of effective, long-term chlorinated ethenes (ClE) dechlorination. The consortium consisted mainly of Dehalococcoides but also of other anaerobic bacterial strains capable of partial dechlorination of ClE, including the sulphate-reducing bacteria; Geobacter and Desulfitobacterium. The average chlorine number in the groundwater decreased from 3.65 to 1.38 within 2.5 years after the injections, while the average ClE concentration increased from 13.5 to 31.5 mgL-1 because of the substantial acceleration of the ClE mass-transfer to the groundwater caused by the treatment. The remediation processes remained fully active for 2.5 years.

Azimuth stern drive (ASD) vector tugs positioning and towing force prediction during docking, steering and braking maneuvers

Ship Maneuvering Simulators have proved to be powerful tools for analyzing the feasibility of docking, steering, and braking maneuvers under the assistance of tugboats. To represent tugboats’ actuation, the so-called “vector tug” model is normally applied. This model is usually represented as simplified external forces, causing a significant loss of realism concerning the tugboat’s towing force and its actuating position. The main objective of this work is to provide an innovative approach for vector tug actuation modeling in such a way that both the towing forces and tugboat positions are correctly predicted during direct Push and Pull operation modes, which are usually performed under low speeds, during docking maneuvers. Besides, the steering and braking maneuvers will be addressed, with the corresponding predictions during the Indirect Pull operation, where the tugboat acts as an aerofoil, with the resultant lift force generated being transmitted across the tow line. In order to perform the predictions, the authors first used CFD methods to obtain the hydrodynamic coefficients for a harbour tugboat hull and an escort tugboat hull. Afterwards, they developed a Static Equilibrium Model combined with optimization techniques. The obtained results were validated against literature data and in the Numerical Offshore Tank Laboratory (TPN-USP) simulator.

Field evaluation of 1.75 groundwater profiler and field screening device for on-site contamination profiling of chromium(VI) in groundwater

Groundwater contamination by toxic heavy metals pose serious health hazards to humans and the environment. The remediation of contaminated groundwater requires effective characterization of the concentrations and spatial distribution of heavy metals. Groundwater samples from long screening monitoring wells do not provide an accurate representation of the distribution of heavy metals with depth, as the data obtained from the well are an average along the screen length. This study reports the development and application of two new technologies, a direct push 1.75 groundwater profiler (GWP) that obtains groundwater samples from multiple depths in a single push, and a portable field screening device that uses novel disposable sensors to facilitate rapid, cost-effective, on-site detection of heavy metals in groundwater, surface water, and sediment pore water. Extensive fieldwork was performed at a chromium(VI)-contaminated site to evaluate and validate these two technologies for on-site contamination profiling of Cr(VI) in groundwater. A preliminary investigation was performed with an OIHPT logging tool to determine formation lithology and relative permeability for identifying potential groundwater sampling intervals and contaminant migration pathways in the subsurface. Groundwater samples from selected depth intervals were collected and analyzed by an outside laboratory analysis for total chromium and hexavalent chromium as per EPA standards 6020 (SW) and 7196, respectively. The excellent comparison of the field results with the laboratory test results confirm the potential of these technologies in obtaining high resolution site characterization data to improve the management of heavy metal-contaminated hazardous sites.

Spontaneous Versus Directed Pushing Technique: Maternal and Neonatal Outcomes: A Comparative Study in Northern Upper Egypt

Background: Maternal pushing during the 2nd stage of labor is indispensable and important contributor to the involuntary expulsive force developed by uterine contraction results to influence on the mother and fetus. Aim: the study was conducted to compare spontaneous versus Valsalva (directed) pushing techniques at the second stage of labor on maternal and fetal outcomes. Methods: Setting: Delivery Unit of El-Fayoum General and University Hospitals. Design: A quasi-experimental comparative study. Subjects: A purposive sample of a total of 100 primiparous women; 50 in the Valsalva (directed) pushing group & 50 in the spontaneous pushing group. Tools: four tools were used; structured interviewing questionnaire sheet, Apgar score, Visual analog scale, and women satisfaction questionnaire. Results: The duration of the second stage of labor was shorter (5-10 min) in a spontaneous pushing (54.0%) group compared to the direct pushing group (2.0%). Oxygen wasn't used at all in spontaneous pushing group compared to 74.0% of directed pushing group. Postpartum hemorrhage was too little in spontaneous pushing group (96.0%) compared to 36.0% of the directed pushing group. Also, all women in the spontaneous pushing group experienced mild perineal pain compared to 32.0% in the directed pushing group (p<0.001). The individual items of the VAS were significantly higher in the directed pushing group than those in the spontaneous pushing group. According to Apgar's score, there was a significant difference between the two groups during both the first and fifth minutes of birth. In the directed pushing group, a higher proportion of babies are admitted to ICU than those in the spontaneous pushing group (18.0 percent versus 10.0 percent). Conclusion; spontaneous pushing during the 2nd stage of labor enhanced neonatal and maternal outcomes; whilst directed pushing was associated with an increased duration of the 2nd stage of labor and risk of adverse neonatal outcomes. Recommendations: It may be recommended that spontaneous pushing during the second stage of childbirth be included in the procedure for maternal hospitals.

Research on anomaly data mining method of new energy field stations based on improved Adaboost algorithm

Traditional anomalous data mining methods require a lot of prior knowledge, which leads to low data mining integrity and efficiency. For this reason, a new energy field abnormal data mining method based on improved Adaboost algorithm is proposed. After pre-processing the new energy field data, the algorithm is improved by introducing dynamic weight parameters to address the shortcomings of the Adaboost algorithm. After calculating the degree of data anomaly using the direct push belief machine, the neural network is used to reduce the error value of the Adaboost algorithm, and finally the output of the Adaboost algorithm is used to realize abnormal data mining. The simulation experiment proves that the researched abnormal data mining method has high data integrity and high efficiency.

The Spherical Inverted Pendulum: Exact Solutions of Gait and Foot Placement Estimation Based on Symbolic Computation

The gait and the Foot Placement Estimation (FPE) has recently been extended to 3-D spaces by adopting a specific form of a spherical inverted pendulum (SIP). The approach is very attractive, as it does not involve dynamics, but it is based solely on energies and momenta, however the authors (DeHart et al.) introduced several questionable approximations, in order to reach a manageable solution. The scope of the present paper is to revisit this spherical inverted pendulum applied to biped walking, offering an exact solution to the gait and the FPE by using symbolic computation. This is facilitated by exploiting the Kane’s approach to dynamical modelling, and his software environment for symbolic manipulation, called Autolev. It generates explicit formulas describing the energies and angular momenta before/after the impact, along with the mechanics of the impact. As the resulting equations, function of (measurable) angular positions and velocities, are very compact, embedded in a numerical nonlinear solver, are suitable to be implemented in real time and used in practice to control biped robots or lower limb exoskeletons. The two main contributions of the paper are: the recovery of the balance by stepping, in the presence of a push in an arbitrary direction and omnidirectional walking. In this last respect, this specific form of SIP emphasizes the expenditure of energy in the walk. For the first time, at our knowledge, the walk of the SIP, based on energy, has been compared to the simulation of a 12 degrees of freedom biped robot tracking preview signals using the Zero Moment Point (ZMP) of the Linear Inverted Pendulum (LIPM). This quantitatively shows the inefficiency, in terms of energy, of the ZMP-based walk, and the gain due to the recovery of the collision of the flying foot. Similarity in the sagittal plane and differences in the frontal plane of the center of mass trajectories of the two approaches are shown, to open the road to an integration of fully actuated and underactuated controls, for an efficient full-dimensional robot gait to be developed in a future paper.

Research and Calculation on the Optimization of Hydraulic Lifting Mechanism for New Steel Gate

The steel gate based on the principle of hydraulic lifting mechanism has been widely used in urban water ecological construction, but the retaining height of this kind of gate is mostly l-5m at present. With the development of water conservancy engineering and the deepening of the application research of steel gate, the retaining height gradually grows to 6-8m. However, at present, there are few researches on hydraulic lifting mechanism in the case of large retaining height. In this paper, Inventor is used to firstly establish three-dimensional visual entity models of the direct push type, Booster type and Maleli type hydraulic lifting mechanism. Then, the changing rules and relations among hydraulic cylinder diameter, stroke and stability safety factor of the three hydraulic lifting mechanisms are calculated and analyzed by changing the constraint conditions in the case of large retaining height (4m, 5m, 6m, 7m, 8m) and different opening and closing angles. It is aimed at providing a scientific basis for the optimization of hydraulic lifting mechanism of steel gate under the condition of large retaining height.

Biologically Inspired Surgical Needle Steering: Technology and Application of the Programmable Bevel-Tip Needle.

Percutaneous interventions via minimally invasive surgical systems can provide patients with better outcomes and faster recovery times than open surgeries. Accurate needle insertions are vital for successful procedures, and actively steered needles can increase system precision. Here, we describe how biology inspired the design of a novel Programmable Bevel-Tip Needle (PBN), mimicking the mechanics and control methods of certain insects ovipositors. Following an overview of our unique research and development journey, this paper explores our latest, biomimetic control of PBNs and its application to neurosurgery, which we validate within a simulated environment. Three modalities are presented, namely a Direct Push Controller, a Cyclic Actuation Controller, and a newly developed Hybrid Controller, which have been integrated into a surgical visual interface. The results of open loop, expert human-in-the-loop and a non-expert user study show that the Hybrid Controller is the best choice when considering system performance and the ability to lesson strain on the surrounding tissue which we hypothesis will result in less damage along the insertion tract. Over representative trajectories for neurosurgery using a Hybrid Controller, an expert user could reach a target along a 3D path with an accuracy of mm, and non-expert users mm, both clinically viable results and equivalent or better than the state-of-the-art actively steered needles over 3D paths. This paper showcases a successful example of a biologically inspired, actively steered needle, which has been integrated within a clinical interface and designed for seamless integration into the neurosurgical workflow.

Hyperspectral Image Classification With Spectral and Spatial Graph Using Inductive Representation Learning Network

Convolutional neural networks (CNN) have achieved excellent performance for the hyperspectral image (HSI) classification problem due to better extracting spectral and spatial information. However, CNN can only perform convolution calculations on Euclidean datasets. To solve this problem, recently, the graph convolutional neural network (GCN) is proposed, which can be applied to the semisupervised HSI classification problem. However, the GCN is a direct push learning method, which requires all nodes to participate in the training process to get the node embedding. This may bring great computational cost for the hyperspectral data with a large number of pixels. Therefore, in this article, we propose an inductive learning method to solve the problem. It constructs the graph by sampling and aggregating (GraphSAGE) feature from a node's local neighborhood. This could greatly reduce the space complexity. Moreover, to enhance the classification performance, we also construct the graph using spectral and spatial information (spectra-spatial GraphSAGE). Experiments on several hyperspectral image datasets show that the proposed method can achieve better classification performance compared with state-of-the-art HSI classification methods.

Direct push, in situ video imaging of buried prehistoric landscapes in soft soils: First results in the polders, coversands, and loess belt of Belgium

Since the introduction of direct push sensing, and more specifically, cone penetration testing, in prehistoric paleolandscape mapping, applications have been limited to mapping relatively thick and lithologically contrasting sedimentary units in fluvial and estuarine floodplains. However, this study investigates techniques to map thinner and less contrasting sediments, and soil horizons in soft soils outside these floodplains as well. Therefore, cone penetration testing and electrical conductivity logging are assessed in combination with the first paleolandscape mapping application of direct push, in situ video imaging in test cases situated in the polders, coversands, and loess belt of Belgium. The results reveal that the discrimination potential of archaeologically relevant, litho- and pedostratigraphic units through direct push sensing is increased in the respective regions. Despite the necessity of hardware updates and further developments in video data processing, a combination of cone penetration testing, electrical conductivity logging, and in situ video imaging is readily applicable to extensive mapping of deeply buried prehistoric paleolandscapes.

From “Government to Governance”? A Systematic Literature Review of Research for Urban Green Infrastructure Management in Latin America

The concept of Urban Green Infrastructure (UGI) has emerged in response to the need to highlight and ensure access to the multifunctional benefits of green spaces in changing cityscapes. Recent literature reviews around UGI have focused on environmental benefits and services, and the management of these spaces has been comparatively neglected. In addition to this, the core conceptual and practical research around UGI management has been produced in the Global North, and far less research has been generated in Latin America, despite the contextual challenges and opportunities brought by this rapidly urbanizing and diverse region. In response, this trilingual systematic review asks: What are the research trends in terms of topics, and case studies that characterize UGI management research in Latin America? Which management types are the focuses of this research? A total of 47 publications, found through Scopus, Web of Science and SciELO, were subjected to both quantitative and qualitative assessment. The research was both geographically concentrated and predominantly recent. Government-led initiatives made up the highest proportion of the research, and more than half of the publications described local government as the principle actor in the management of the UGI studied. Community-run initiatives were consistent across the temporal span of the articles found, and their established presence was supported by the qualitative review. Findings also revealed a directional push towards governance practices, but significant obstacles in the form of: weak local government; divisions driven by a lack of context-sensitive approaches to informal settlements and socioeconomic segregation, and a management discourse that jarred with urban practices by indigenous communities. Through demonstrating the contribution of existing literature on UGI management in Latin America, this review highlights the need for further published research on the region.

Millennial-scale terrestrial ecosystem responses to Upper Pleistocene climatic changes: 4D-reconstruction of the Schwalbenberg Loess-Palaeosol-Sequence (Middle Rhine Valley, Germany)

Loess-Palaeosol-Sequences (LPS) in the Central European region provide outstanding terrestrial polygenetic and multiphase archives responding to past climate and environments over various spatial and temporal scales. As yet, however, the geomorphological and pedogenic processes involved in LPS formation, and their interplay with changes in ecological conditions, impede robust correlation with other palaeoenvironmental archives. The Schwalbenberg LPS, which drape a hillslope in the Middle Rhine Valley in western Central Europe, provide unique high-resolution records highly suitable for investigating the processes involved in their formation and the relationship to climatic influences during the Upper Pleistocene. Here we present the first comprehensive multi-proxy dataset for the Schwalbenberg LPS over four dimensions. We undertake systematic analyses along a representative slope transect using surface-based geophysical prospection in combination with Direct Push hydraulic profiling to characterise the subsurface stratigraphy in detail. We integrate selected sedimentological and geochemical proxy data from three long sediment cores and two profile sections to build a complete stratigraphical succession for the Schwalbenberg LPS. We show that the transect approach allows quantification of different formation phases, whether accumulative, erosive or pedogenic in character. In so doing we overcome the bias inherent in studies of individual sections and enable robust and reliable correlation with other climate archives. For the time interval ~ 80–15 ka BP correlation of combined lithostratigraphic features and organic carbon contents from Schwalbenberg with the Sofular and NGRIP δ18O-records can be established at millennial to centennial scale resolution, highlighting the sensitivity of western European LPS to the Atlantic-driven climate oscillations in much more detail than in any other terrestrial archive known in the region so far.