Drain Line Research Articles

Achieving Success by Validation! Decontamination Protocols of Category A Medical Waste for Patients with Serious Communicable Diseases

<h3>Purpose</h3> During the 2014 Ebola outbreak, treatment centers for Ebola and special pathogens had to determine safe handling protocols for the management of category A infectious substances. There have been challenges achieving validation of adequate sterilization with autoclaving. To achieve successful inactivation requires alteration of cycle parameters (temperature, pressure, and time), and packaging methods. Successful inactivation is verified through the use of biological indicators, data loggers, and the evaluation of drain and exhaust lines. We aim to describe a successful waste sterilization process utilizing an autoclave in Emory University Hospital's biocontainment unit where we maintained appropriate safe handling waste processes. <h3>Methods & Materials</h3> Waste was differentiated by type to include patient general waste, linens, liquids, and sharps (including continuous renal replacement therapy cartridges). This helped us to determine appropriate packing methods and cycle parameters to ensure adequate inactivation by autoclaves. A biological indicator (BI) was used to monitor the efficacy of the autoclave sterilization process. Waste was double bagged with autoclave bags using the "gooseneck" method and secured with autoclave tape. This allowed for waste packaging to maintain closure of biohazard bags and contain leaks and aerosols. Following failed loads, action plans were generated until achieving successful inactivation. In order to determine the effectiveness of autoclave sterilization parameters, repeat loads were performed to ensure reliability. Once cycle specifications were finalized, each cycle type was repeated to achieve three successful runs with all passing biological indicators. <h3>Results</h3> We achieved effective inactivation of waste by altering autoclave factory settings. Following separation of waste and determine appropriate packing methods, we ran 26 total cycles achieving passing biological loads in 17 cycles. Failed loads occurred primarily in liquids and sharps where parameters were readjusted until achieving three successful cycles. <h3>Conclusion</h3> Safe handling of category A infectious waste requires validation of inactivation of waste by autoclave. Validation of autoclave parameters need to be assessed with particular attention to waste loads and packaging prior to treatment. We achieved successful inactivation of infectious medical waste with simulated patient waste loads while maintaining the integrity of waste packaging to ensure no leakage of liquid or aerosol particles occurred.

Application of Electrocoagulation in Street Food Wastewater

Street food is commonly known as ready-to-eat and go foods and beverages, which is very famous in Thailand and other Asian countries. The street food daily generates high organic content and oily wastewater from washing and rinsing plates. The discharge of street food wastewater to public drains leads to a clogged drain line and unpleasant smell. In this work, an electrocoagulation (EC) system with monopolar aluminum (Al) electrodes was developed to treat two well-known street foods; Hainanese chicken rice (HC) and noodles and dumplings (ND). The results revealed that excellent chemical oxygen demand (COD) and fat, oil, and grease (FOG) removals were achieved under a specific operating condition (i.e., an electric current of 20 mA/cm2 and electrolytic time of 10 min). The initial COD of HC wastewater decreased from 40.6 g/L to 1.9 g/L, approximately 95%, whereas the FOG decreased from 310 mg/L to 50 mg/L, approximately 84%. The lower initial COD and FOG concentrations of ND wastewater obtained approximately 98% for COD removal and 86% for FOG removal; the effluent contained 0.5 g/L of COD and 25 mg/L of FOG. In addition, a relatively low Al concentration of 0.02–0.08 mg/L was observed in the effluents. The appropriate design factors together with ease of use and fast pollutants removal were significant advantages of this study; the EC system has potential to apply to on-site street food treatment.

Застосування штучної нейронної мережі для визначення рівня зношеності циліндро-поршневої групи автотракторного двигуна

The article proposes reducing the redundancy of the neural network and the need to reduce the number of neurons in the hidden layer for a given level of network learning error. The minimum number of neurons of the hidden layer for the case of 11 monitoring standard sensors, the parameters of the automobile and tractor engine (ATE) and five classes of typical defects of the ATE nodes can be reduced to 5-7 with a high quality of recognition of the state of the ATE engine. The goal is to provide an expanded reliable knowledge base, the speed of information processing, the accuracy of the resulting technical diagnosis and the ability to quickly determine the technical state of an automotive engine in the mode real time. The basis of the proposed method is to ensure obtaining an extended reliable knowledge base, the speed of information processing, the accuracy of the obtained technical diagnosis and the ability to quickly determine the technical state of an ATE engine in real time. A feature of the proposed method is the use of voltages obtained in an artificial neural network from sensors that are standard in an ATE engine as input signals, and additionally indicate the output signal of the fuel cut-off device, provided for one step, containing a winding of a normally closed electromagnetic valve, which redirects fuel to the drain line. The use of the algorithm for identifying the values of the indicators of operating modes and malfunctions of the cylinder-piston group is the result of the analysis of an artificial neural network, which receive the results of the diagnostic parameters of the automotive engine. Having studied the artificial neural network 1 with different volumes of training data, we obtained the dependence of the change in the reliability of the result on the size of the training data and the reliability of the recognition result is 91.2%, the optimal amount of training data is 1200. Having examined the artificial neural network 2 with different volumes of training data, we obtained the dependence of the change in the reliability the result from the size of the training data and the reliability of the recognition result is 86.5%, the optimal amount of training data is from 10 to 15. The results obtained show the fundamental possibility of creating predictive models of units and assemblies of the tested automotive engines. The model can be created using the apparatus of artificial neural networks and using a fairly large database of tests performed.

Vibration diagnostics of hydraulic dozer drives

The most labor-consuming maintenance element in mining is repair&mdash;it can amount to 70 % of total by-work load. Improvement of repair methods and reduction in number of equipment failures can save cost of repair. An important task in operation of mining machines is studying the feasibility of transition from the scheduled maintenance and repair to the condition-based maintenance. To this effect, it is necessary to upgrade diagnostic techniques. Hydraulic drives are widely employed in mining machines. One of the ways of trouble-shooting improvement is advancement of vibration diagnostics advantageous for the eliminated assembling&ndash;dismantling, simplicity of the vibration sensor installation, and low sensitivity to various exposures of a mining machine. Vibration diagnostics enjoys wide application in many areas of engineering and is highly promising for diagnosing of hydraulic dozer drives. This article presents the experimental studies into vibration spectra of walls in the pressure and drain lines in some dozers. The studies have found that the main harmonics of feed pulsations governed by operation of volumetric pumps is observed along the whole length of the pressure line. Therefrom, the authors put forward an idea of detecting spillovers in hydraulic systems. The theoretical computations of vibration parameters are currently very complicated. The leading part in the vibration diagnostics development should belong to the experimental research.

МАТЕМАТИЧНЕ МОДЕЛЮВАННЯ ВЗАЄМОДІЇ СІТЧАСТИХ РОЗДІЛЮВАЧІВ ФАЗ С ГАЗОВИМИ ПУЗИРЯМИ В УМОВАХ ЗМІННОГО ПОЛЯ МАСОВИХ СИЛ

Modern multi-purpose spacecraft for several years must perform complex and diverse tasks in outer space. At the same time, it is necessary to turn on jet engines dozens of times in conditions of practical weightlessness. At the time of starting the engine, the liquid fuel is mixed randomly with the boost gas. In this case, it is impossible to guarantee the contact of the drainage hole with the gas phase, and the drain hole with the fuel. To solve this problem, it is proposed to use various, so-called means of ensuring the continuity of fuel (MECF). The effectiveness of monitoring the position of the liquid in the flight conditions of the aircraft in the passive section of the trajectory is determined by the ability of the MECF to ensure the discharge of fuel from the tank without gas inclusions at any required time with a given flow rate and in the required amount with a minimum volume of unselected residues.&#x0D; The article deals with the features of the functioning of the SOST of the inertial type, which includes mesh phase separators (MPS). The need to use the MPS is due to the possibility of the gas phase entering the drain line, both in the passive section of the trajectory and at the stage of switching on the main engines, which can lead to a disruption of their launch. When fuel moves into the drain line, bubbles remain on the mesh surface and prevent the passage of liquid. &#x0D; The article builds a mathematical model of the behavior of gas bubbles on the surface of the MPS in the flow of a viscous liquid. On the basis of the constructed mathematical model, the corresponding numerical calculations were carried out. The proposed method of engineering calculation makes it possible to determine such a MECF design that excludes the possibility of "contamination" of the surface of the MPS by gas bubbles and the disruption as a result of this normal functioning of the fuel supply system to the engines of spacecraft.

Time of day impact on mapping agricultural subsurface drainage systems with UAV thermal infrared imagery

Due to economic and environmental considerations, there exists a need for effective, efficient, and nondestructive methods for locating buried agricultural drainage pipes. Previous research indicates that thermal infrared (TIR) imagery obtained with an unmanned aerial vehicle (UAV) has potential for mapping agricultural subsurface drainage systems, thereby warranting further investigation to determine the best time of day to conduct these UAV TIR surveys. Accordingly, a set of sunrise to sunset UAV TIR surveys were carried out at four different farm field sites in Ohio, U.S.A. Late morning through late afternoon UAV TIR surveys were generally found to work well for determining drainage system patterns. During late morning through late afternoon, the apparent radiant temperature of the soil surface over the drain lines was higher than between the drain lines (i.e., emitted TIR radiation from the soil surface over a drain line was greater than between the drain lines). Conversely, near sunrise or sunset, the UAV surveys often showed the apparent radiant temperature of the soil surface over the drain lines to be lower than between the drain lines (i.e., less emitted TIR radiation over the drain lines than between drain lines). Some excellent UAV TIR drainage mapping results were obtained near sunrise/sunset due to TIR drain line responses that were more easily distinguished from those of farm field operations. However, difficulties were occasionally encountered processing this sunrise/sunset TIR imagery, likely due to the impact on image quality from high relative humidity during these times of the day. Consequently, strictly on a consistency of success basis alone, late morning through late afternoon are the best times for locating drainage pipes with UAV TIR surveys; however, in certain cases, UAV TIR surveys at sunrise/sunset can provide exceptional drainage pattern recognition. These results provide valuable guidance for those considering UAV TIR drainage mapping surveys.

Mapping of Agricultural Subsurface Drainage Systems Using Unmanned Aerial Vehicle Imagery and Ground Penetrating Radar.

Agricultural subsurface drainage systems are commonly installed on farmland to remove the excess water from poorly drained soils. Conventional methods for drainage mapping such as tile probes and trenching equipment are laborious, cause pipe damage, and are often inefficient to apply at large spatial scales. Knowledge of locations of an existing drainage network is crucial to understand the increased leaching and offsite release of drainage discharge and to retrofit the new drain lines within the existing drainage system. Recent technological developments in non-destructive techniques might provide a potential alternative solution. The objective of this study was to determine the suitability of unmanned aerial vehicle (UAV) imagery collected using three different cameras (visible-color, multispectral, and thermal infrared) and ground penetrating radar (GPR) for subsurface drainage mapping. Both the techniques are complementary in terms of their usage, applicability, and the properties they measure and were applied at four different sites in the Midwest USA. At Site-1, both the UAV imagery and GPR were equally successful across the entire field, while at Site-2, the UAV imagery was successful in one section of the field, and GPR proved to be useful in the other section where the UAV imagery failed to capture the drainage pipes’ location. At Site-3, less to no success was observed in finding the drain lines using UAV imagery captured on bare ground conditions, whereas good success was achieved using GPR. Conversely, at Site-4, the UAV imagery was successful and GPR failed to capture the drainage pipes’ location. Although UAV imagery seems to be an attractive solution for mapping agricultural subsurface drainage systems as it is cost-effective and can cover large field areas, the results suggest the usefulness of GPR to complement the former as both a mapping and validation technique. Hence, this case study compares and contrasts the suitability of both the methods, provides guidance on the optimal survey timing, and recommends their combined usage given both the technologies are available to deploy for drainage mapping purposes.

Detecting subsurface drainage pipes using a fully convolutional network with optical images

More than half of croplands in the Midwestern United States are equipped with subsurface drainage pipes to reduce excess water in productive but wet areas. The use of drainage systems not only reduces subsurface water table to prevent waterlogging and flooding but also increases nutrient losses by developing artificial preferential flow paths. The exact locations of subsurface drainage pipes are thus imperative to manage and monitor water quality and nonpoint source pollution. However, such data are not widely available due to private ownership. Previous studies used conventional image filtering methods, thermal images, and ground penetration radar to detect subsurface drainage pipes. Due to surface features, such as furrow and depressions, and their limited data availability, these experiments did not provide a robust approach to identify subsurface drainage pipes over a large area. To overcome these limitations, in this study, we propose a subsurface drainage pipe detection approach based on deep learning with optical images. Our deep learning approach uses a fully convolution network (FCN) architecture that takes an optical image patch as an input and gives an output of pixel-wise drainage pipe detection map. The FCN was trained and validated using optical image datasets obtained from a freeware Google Earth that provides temporally and spatially abundant data. The trained FCN was then applied to large-scale drainage pipe detection tasks to evaluate its performance. The performance comparison between the proposed deep learning approach and conventional image processing techniques (Sobel and Canny edge detection methods) was also carried out. The results demonstrate that the proposed deep learning approach shows accurate and robust drain line detection performance with an average Dice coefficient of 0.58 for validation sets, providing superior performance over the conventional image processing techniques.

Hardware-Based Spiking Neural Network Using a TFT-Type AND Flash Memory Array Architecture Based on Direct Feedback Alignment

A hardware-based neural network that enables on-chip training using a thin-film transistor-type AND flash memory array architecture is designed. The synaptic device constituting the array is characterized by a doped p-type body, a gate insulator stack composed of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> /Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> , and a partially curved poly-Si channel. The body reduces the circuit burden on the high voltage driver required for both the source and drain lines when changing the synaptic weights. The high- κ material included in the gate insulator stack helps to lower the operating voltage of the device. As the device scales down, the structural characteristics of the device have the potential to increase the efficiency of the memory operation and the immunity to the voltage drop effect that occurs in the bit-lines of the array. In an AND array architecture using fabricated synaptic devices, a pulse scheme for selective memory operation is proposed and verified experimentally. Due to the direct feedback alignment (DFA) algorithm, which does not need to have the same synaptic weight in the forward path and backward path, the AND array architecture can be utilized in designing an efficient on-chip training neural network. Pulse schemes suitable for the proposed AND array architecture are also devised to implement the DFA algorithm in neural networks. In a system-level simulation, a recognition accuracy of up to 97.01% is obtained in the MNIST pattern learning task based on the proposed pulse scheme and computing architecture.

Static and Seismic Performance of Buried Pipelines: A review

Today, buried pipes can be considered one of the main substantial infrastructures which has significant role with human life. Such projects serve purposes, including, drain lines, water mains, sewage lines, telephone and electrical conduits, highway and railway culverts, gas and liquid-petroleum lines, coal slurry lines, subway tunnels and various other special functions. This paper focuses on reviewing, describing and understanding the static and dynamic behavior of underground pipes during earthquake events and at rest condition involving seismic vulnerability causes, failure modes of pipelines and loads subjected on pipes. A quick glance on the assisting factors that reduce the pipes breakage due to earthquakes is presented. Also, this paper reviews some previous studies about performance of underground pipes under seismic loads. It was concluded that the soil density has a significant impact on the displacements corresponding to the maximum force. For shallow pipes to obtain the minimum lateral displacement value, it is recommended to use soil density medium to dense state. It was observed also there is a relationship between the spacing of pipes and its displacement so; to obtain the minimum displacement the spacing between the pipes must be at least equal to the pipe diameter.

Thermally Stressed State of Headers and Steam Pipelines in the Flowpath of Combined-Cycle Power Plants during Their Heating with Condensed Steam

One of the problems arising in start-up modes of combined-cycle power units is the preheating of steam pipelines in the high- and intermediate-pressure steam path whose time has a considerable effect on the total start-up time, especially during cold start-ups. Steam condenses on the inner surface during startups of combined-cycle power units in the process of increasing the pressure of high-pressure steam when the initial temperature of a heated part is below the saturation temperature or when a heated surface with a high initial temperature is exposed to the saturated steam at its current pressure for a long time. The paper considers the effect of heat transfer due to the steam condensation on the heated wall of steam pipelines (or headers) on their thermally stressed state. It has been demonstrated that the level of temperature stresses arising in the wall of the steam pipeline is insignificant with this heating since almost all the temperature difference occurs across the condensate film whose heat conductivity is much lower than that of the heated metal wall. Damages to steam pipelines, usually in the form of cracks in drain or impulse lines near the points of their welding to the steam pipelines, are caused by the explosive nature of the boiling during pressure fluctuations in the steam pipelines and by the impact of liquid drops on the “dry” surface of the steam pipeline. The heating of the steam pipeline with increasing pressure and condensation of steam on its wall does not result in considerable thermal stresses in it during the entire stage of heating with condensed steam. Only after the saturation temperature is attained, when there is no more condensation on the wall surface of the heated steam pipeline, temperature stresses appear, whose values are determined by the temperature difference between the steam and the inner surface of the steam pipeline and convective heat-transfer coefficients which are an order of magnitude lower than those observed during heating by steam condensation.

Stabilization of the movement speed of the output link of the hydraulic actuators in the volumetric hydraulic drive

In a volumetric hydraulic drive the speed control of the hydraulic actuators output link is provided by changing the working volume of the pump (VOLUMETRIC CONTROL) or by changing of the hydraulic resistance of the lines (THROTTLE CONTROL). The latter provides for installation of an adjustable throttle in the pressure or drain line for hydraulic motor (sequential primary or secondary regulation), as well as, a controlled bypass of the pump supply into its suction line. Since during the throttle control of the speed of an output link of the hydraulic motor, load determines the pressure drop across the throttle and, therefore, the volumetric flow rate in the line, this control method cannot ensure the invariance of the volumetric hydraulic drive to the load on the actuator, which is necessary if it is used to rotate or to provide the antenna scanning for the radar stations and also the radar for the mobile above-water and land transport systems, that having a high sailing are exposed to significant contrary and fair wind load. In this case, the high quality of the stabilization of the loaded output links rotation speed is possible only in the case of using instead off a throttle the flowcontrollers. At the same time, it should be noted, that in the conditions of the more strict requirements for the control accuracy oblige to use the servo-hydraulic drive with the negative feedback in angular velocity of the output shaft rotation. Authors of the proposed article are consider the design features of some typical 2- and 3-linear flow controllers and also carried out a set of experimental studies of volumetric hydraulic drive with throttle control, provided 3-linear flow-controller, as a result of which the kinematic and dynamic characteristics of the volumetric hydraulic drive with a changing load on the output link at main and additional (secondary) hydraulic motors were obtained. The received results of experimental studies allowed for this article authors elaborate the adequacy of the developed mathematical model of a 3-linear flow-controller and to offer methodological recommendations for determining the parameters of its own components. In the conditions of limited availability of information on the design features and methodology of the flow-controllers, the results of experimental studies and proposed mathematical model of a 3-linear flow-controller can have some value in developing designs of flow-controllers, determining the parameters of their component elements, as well as in the use the flow-controllers in the loadinvariant volumetric hydraulic drives.

Fully Passive-Printed Wireless Wear Sensor

Wear of abradable materials presents a significant challenge across many industries, where the efficiency, efficacy, and safety of important systems rely on the detection and monitoring of component wear. Three design variations demonstrate real-time monitoring of wear by a novel, additively manufactured, embeddable, and fully passive wireless wear sensor. The three sensor designs incorporate closely spaced, narrow interconnects connected to a parallel resistor circuit, with a passive RFID chip for complete remote operation. The first design includes ten closely spaced horizontal interconnects and tracks wear events orthogonal to the interconnects for a resolution of $200~{\mu }\text{m}$ . The second design divides horizontal interconnects into two interdigitated sets of five lines each to achieve a resolution of $125~{\mu }\text{m}$ . The third design features ten interconnects printed vertically and connected to a sloped drain line to achieve a resolution of $50~{\mu }\text{m}$ . We fabricated all three designs with a single-layer print on machinable glass-ceramics and commercial surface-mount resistors. Lab testing showed that the three sensor designs had an overall experimental resolution of 215.3, 127.8, and $57.34~{\mu }\text{m}$ , respectively. We attribute error to a combination of manufacturing challenges related to the printing of orthogonal and acute angled narrow interconnects, RFID sampling rates, and errors from testing. The maximum error in measured voltage steps for each of the three designs is 10%, 6.67%, and 6.78%. This study is limited in sample size due to testing constraints and is presented as proof of concept. Future work should assess the robustness of these designs and processes.

Retention of Molten Corium in Calandria Vessel of PHWR With Moderator Drain Pipe

Abstract Retention of molten corium inside calandria vessel is crucial for arresting accident progression in pressurized heavy water reactors (PHWRs) during severe accidents. Our earlier tests have demonstrated corium retention and its cooling inside the calandria vessel of PHWRs through external cooling by vault water. However, the presence of nozzles and moderator drain pipe at the bottom of calandria vessel has not been considered in these studies. These nozzles and drain pipes used for moderator circulation can make the viability of corium retention even more challenging. Once the moderator has evaporated, debris reheating, compacting, and finally melting can cause the release of molten corium into the moderator recirculation system. This can lead to the relocation of corium beyond calandria vessel. The corium might reach the pump room or calandria vault after the failure of moderator drain pipe and/or moderator pump seals. This has severe consequences on containment integrity due to molten corium concrete interaction (MCCI). The risks posed by MCCI can be avoided if corium can be contained inside calandria vessel even with the presence of nozzles (at the bottom of the vessel) or if at all it enters into the drain line, does not cause its failure. Thus, it becomes crucial to evaluate the challenges faced by “in-vessel retention” (IVR) as a severe accident management strategy due to the presence of openings in the calandria vessel. Relatively colder debris present near the bottom of calandria vessel might help in obstructing the nozzles of the moderator drain line and can prevent the entry of hot molten corium into the moderator cooling line. The role of debris, therefore, becomes important under such scenarios for not just insulation of calandria vessel from hot corium but also for retention of corium within the vessel. In this article, these issues are addressed by conducting two sets of experiments for assessment of retention capability (IVR) of calandria vessel: (i) with the presence of debris and (ii) without debris at the bottom of calandria vessel. The moderator recirculation line was scaled to simulate the heat transfer from corium to vault water and solidification of corium simulant while flowing through the moderator drain pipe. It was observed that debris bed present at the bottom of the vessel helps in arresting the molten corium front and thus prevents corium from entering into moderator drain pipe. When experiments were conducted without debris, molten corium was found to be relocating in the moderator drain pipe. The drain pipe, however, did not fail under the thermal load.

Wheel track loosening can reduce the risk of pesticide leaching to surface waters

AbstractWheel tracks can lower topsoil infiltrability and increase water ponding in agricultural fields. A seedbed harrow mounted with two goosefeet tine points, the eradicators, was used to investigate track loosening at different depths on a sandy loam soil as a way of mitigating compaction effects and reducing the risk of pesticide transport to surface waters. Loosening strongly affected air permeability and steady‐state infiltration. The agro‐ecological system model Daisy was used to simulate the effects of soil structural and hydraulic changes on pesticide leaching to subsurface drain lines over a 332‐year period. Measured properties of the topsoil were combined with a representative subsoil and weather series and with realistic management scenarios. The loads of pesticide in the drains for 3 months after loosening were calculated for each year, and the risk was defined as the 90th percentile of the load. We focused on three different herbicides used in sugar beet cultivation in spring: glyphosate, metamitron and phenmedipham. Our simulations showed that for all pesticides loosening could lower the risk by 10% on average for a 3‐m working width, and the tracks contribution to the risk by 34%, for all drain spacing and working width settings. Wheeling did not affect the risk but this result was sensitive to the parameterization of the hydraulic conductivity in the compacted soil layer, showing potentially higher risk under certain conditions. These results showed that wheel track loosening is an effective strategy for reducing the risk of surface water contamination from pesticides used in agriculture.

3D AND-Type Stacked Array for Neuromorphic Systems.

NOR/AND flash memory was studied in neuromorphic systems to perform vector-by-matrix multiplication (VMM) by summing the current. Because the size of NOR/AND cells exceeds those of other memristor synaptic devices, we proposed a 3D AND-type stacked array to reduce the cell size. Through a tilted implantation method, the conformal sources and drains of each cell could be formed, with confirmation by a technology computer aided design (TCAD) simulation. In addition, the cell-to-cell variation due to the etch slope could be eliminated by controlling the deposition thickness of the cells. The suggested array can be beneficial in simple program/inhibit schemes given its use of Fowler–Nordheim (FN) tunneling because the drain lines and source lines are parallel. Therefore, the conductance of each synaptic device can be updated at low power level.

Mapping of Agricultural Subsurface Drainage Systems Using a Frequency-Domain Ground Penetrating Radar and Evaluating Its Performance Using a Single-Frequency Multi-Receiver Electromagnetic Induction Instrument.

Subsurface drainage systems are commonly used to remove surplus water from the soil profile of a poorly drained farmland. Traditional methods for drainage mapping involve the use of tile probes and trenching equipment that are time-consuming, labor-intensive, and invasive, thereby entailing an inherent risk of damaging the drainpipes. Effective and efficient methods are needed in order to map the buried drain lines: (1) to comprehend the processes of leaching and offsite release of nutrients and pesticides and (2) for the installation of a new set of drain lines between the old ones to enhance the soil water removal. Non-invasive geophysical soil sensors provide a potential alternative solution. Previous research has mainly showcased the use of time-domain ground penetrating radar, with variable success, depending on local soil and hydrological conditions and the central frequency of the specific equipment used. The objectives of this study were: (1) to test the use of a stepped-frequency continuous wave three-dimensional ground penetrating radar (3D-GPR) with a wide antenna array for subsurface drainage mapping and (2) to evaluate its performance with the use of a single-frequency multi-receiver electromagnetic induction (EMI) sensor in-combination. This sensor combination was evaluated on twelve different study sites with various soil types with textures ranging from sand to clay till. While the 3D-GPR showed a high success rate in finding the drainpipes at five sites (sandy, sandy loam, loamy sand, and organic topsoils), the results at the other seven sites were less successful due to the limited penetration depth of the 3D-GPR signal. The results suggest that the electrical conductivity estimates produced by the inversion of apparent electrical conductivity data measured by the EMI sensor could be a useful proxy for explaining the success achieved by the 3D-GPR in finding the drain lines.

Sources and subsurface transport of dissolved reactive phosphorus in a semiarid, no-till catchment with complex topography.

The subsurface transport of dissolved reactive phosphorus (DRP) from artificially drained agricultural fields can impair water quality, especially in no-till fields. The distribution of soil P in the wheat (Triticum aestivum L.)-dominated Palouse region in the inland U.S. Pacific Northwest varies greatly due to its steep and complex topography, and a legacy (∼130 yr) of excessive soil erosion and deposition processes. The primary goal of this research was to better understand the magnitude and temporal dynamics of DRP export from an artificial drain line and the variability of subsurface DRP leaching within a long-term, no-till field. Dissolved reactive P in drain line effluent was monitored across three water years. Large intact soil cores were extracted at contrasting field locations (toe and top slope positions) to measure DRP leachate concentration and relative P sorption. Drain line DRP concentration was predominantly >0.05mg L-1 and often exceeded 0.1mg L-1 during winter and early spring. Mean leachate DRP levels were significantly higher in toe slope cores than in top slope cores (0.11 and 0.02mg L-1 , respectively). Saturated hydraulic conductivity varied widely across cores and was not correlated with leachate DRP concentration. All soil cores exhibited high P sorption potential, even under conditions of preferential flow. These findings suggest that much of the DRP transport in these landscapes is derived from P hotspots located in toe slope positions. Application of soil P fertilizer amounts in variable rates that account for spatial variability in P transport may minimize P enrichment and subsequent leaching in these locations.

Methods of on-site inspection of a reinforced concrete bridge exemplified by the bridge over the river Kosopasha

Introduction. An on-site inspection method is a visual examination of an engineering structure aimed at the detection of defects, damages, and disturbances of a construction facility and further issuance of recommendations for their elimination. An on-site inspection method is among the principal ones applied, as it serves to identify all defects of bridge structures during their service lives.&#x0D; Materials and methods. The structures of the bridge over the Kosopasha river, located at the 5+910 km of the Pasha – Sviritsa – Zagubye motor road, the Volkhov District, Leningrad Region, were inspected. An on-site inspection method was applied to collect the information and perform the preliminary analysis.&#x0D; Results. The co-authors described the construction of the bridge elements, including the road deck topping, expansion joints, the safety parapet, sidewalks, hand rails, water insulation, the drain line, the bridge approach, the span, bridge support structures, piers, the bridge abutment, and the under-bridge area. They analyzed the condition of these elements at the time of their inspection; they compiled a report on defects, damages and the bridge deck capacity. The main defects include concrete leaching accompanied by concrete reinforcement denuding, concrete cracking and chipping, absence of safety parapet, partial destruction of rails, and failure of abutment strengthening constructions.&#x0D; Conclusions. Recommendations for the further operation of the bridge were formulated on the basis of inspection results. A set of measures is proposed with the purpose of eliminating the defects and further safe operation of the bridge structure. The recommendations include a set of repair works in respect of particular joints and constructions: removal of dust and dirt from the elements of the bridge topping and sidewalks, repair of minor damages of reinforced concrete structures, shore protection aimed at abutment reconstruction, installation of the safety parapet.

A High-Performance GaN-Modified Nonuniform Distributed Power Amplifier

This article proposes a modified nonuniform distributed power amplifier (NDPA) design to increase the output power and power-added efficiency (PAE) in wideband. In the proposed NDPA, drain-line impedances are recalculated, including the drain-source capacitances, which cannot be ignored as the transistor size becomes larger at high frequencies. In addition, instead of using a large-sized transistor in the first section of the NDPA, the design proposes a method of halving the characteristic impedance by doubling the phase of the drain line. When compared with the conventional NDPA, the modified NDPA shows the power gain and output power characteristics close to those of the ideal NDPA. To obtain high efficiency in the NDPA, a programmable gate-line termination resistance switching technique (PGT) is proposed. The power gain is increased by using the standing wave generated from the mismatched termination, enhancing the PAE. For design verification, two modified NDPA monolithic microwave integrated circuits (MMICs) were fabricated using a commercial 0.25-μm gallium nitride (GaN) high-electron-mobility transistor (HEMT) process. The two-way power-combined NDPA shows an average output power of 20 W or more and a power density of 1.9 W/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> from 6 to 18 GHz. The NDPA using the proposed PGT accomplishes an average output power of 10 W and an average PAE of 20% or more from 6 to 18 GHz.