Horizontal Screen Research Articles

Fish behavior at the horizontal screen of a novel shaft hydropower plant

AbstractPreventing fish entrainment during their downstream passage at hydropower plants remains a major challenge in reducing the ecological impacts of hydropower production. We investigated fish behavior at the world's first innovative shaft hydropower plant with its novel screen concept, aiming at reducing fish entrainment due to the fully horizontal arrangement of the screen and low vertical suction effects toward the turbine. Based on ARIS sonar recordings, we assessed whether fish could move unhindered across the turbine intake area toward the bypass corridors at the sluice gate for safe downstream passage. For a range of species (Anguilla anguilla, Barbus barbus, Thymallus thymallus, Salmo trutta, and Hucho hucho) and operation modes (high/low turbine load), we assessed behavioral patterns such as screen avoidance, dwelling behavior, and search behavior at the screen. Contrary to the engineers' expectations, the innovative screen arrangement neither guided the fish away from the turbine intake to the bypass corridors nor prevented them from swimming vertically into the turbine shaft. Rather, fish freely moved near the screen and avoidance behavior was only rarely observed. Both the dwelling and active search behavior, which was particularly evident in eel, are directly linked to an increased risk of screen passage and subsequent turbine‐related death or injuries. Our findings illustrate that consideration of fish behavior at turbine inlet structures is a crucial component which needs to be integrated with other variables such as fish mortality and injury patterns for a comprehensive evaluation and improvement of fish passage at hydropower plants.

Evaluation of the Performance of a Composite Water Control Process for Offshore Bottom Water Fractured Gas Reservoirs

Natural gas, as one of the main energy sources of the modern clean energy system, is also an important raw material for the chemical industry, and the stable extraction of natural gas reservoirs is often affected by bottom water. It is difficult to control water in natural gas reservoirs, while fractured gas reservoirs are even more demanding. This is due to the complexity of the seepage laws of gas and water in fractures, resulting in the poor applicability of conventional processes for water control. Continuous research is needed to propose a process with effective control capabilities for bottom-water fractured gas reservoirs. Aiming at the above difficulties, this paper is based on a large-scale three-dimensional physical simulation device to carry out physical model design and simulation results testing and analysis. The water control ability of the combination of density-segmented sieve tubes and continuous packers in fractured gas reservoirs is explored. The physical simulation results show that the fracture distribution characteristics control the upward transportation path of bottom water. According to the segmentation characteristics of the fractures at the horizontal section location, optimizing the number of horizontal well screen tube segments and the density of boreholes reduces the cone-in velocity of bottom water before connecting the fractures to a certain extent. And the combined process has different degrees of water control ability for the three stages of bottom water transportation from the fractured gas reservoir to the production well. As the degree of water in the production well increases, the water control ability of the process gradually decreases. After the implementation of the water control process, the water-free gas production period was extended by about 6.84%, and the total production time was extended by about 6.46%. After the shutdown of the horizontal wells, the reduction in daily water production can still reach 21% compared to the natural extraction. The results of this research can provide process suggestions for water control in offshore fractured reservoirs and further ensure stable production in offshore fractured gas reservoirs.

Changes in perceived peripersonal space following the rubber hand illusion

Peripersonal space (PPS), the region immediately surrounding the body is essential for bodily protection and goal directed action. Previous studies have suggested that the PPS is anchored to one’s own body and in the current study we investigated whether the PPS could be modulated by changes in perceived body ownership. While theoretically important, this anchoring can also have implications for patients with altered body perception. The rubber hand illusion (RHI) is a way to manipulate body ownership. We hypothesized that after induction of a left hand RHI, the perceived space around the body shifts to the right. Sixty-five participants performed a landmark task before and after a left hand RHI. In the landmark task, participants had to determine whether a vertical landmark line was left or right from the center of a horizontal screen. One group of the participants was exposed to synchronous stroking, the other group experienced asynchronous stroking. Results showed a shift in space to the right (e.g. away from the own arm), but only for the ‘synchronous stroking’ group. These results suggest that the relevant action space becomes linked to the fake hand. Critically, subjective ownership experience did not correlate with this shift, but proprioceptive drift did. This suggests that multisensory integration of bodily information drives this shift in space around the body and not feelings of ownership.

Effect of Different Screen Types on Head Loss in Deep Wells Used for Irrigation

This research was carried out with the help of a deep well simulator, which is commonly utilized for irrigation studies. In this study, flow types based on Reynolds number, well drawdown, head losses, and cost changes of these head losses were analyzed for four different sieve types used in wells. In addition, the flow types and head losses for the types of screen used were examined as per the theoretical calculations.
 Theoretically, the turbulent head loss among types of screens was calculated at the highest (0.37 m) in the bridge slot screen (ST4) and at least (0.028 m) in the round slot (ST3). The drawdown is the sum of the head losses for deep wells. Among the well-types, the maximum drawdown (113.46 cm) was measured within the bridge slot well type (WT4), and the minimum drawdown (50.37 cm) was measured in the horizontal slot oblong well type (WT2). The least head loss per unit flow rate in the wells was measured in the well, which was formed with a horizontal oblong slot (WT2) screen. Here, gravel and screen hole position affected the percentage of clogging in the screens. Overclogging of the screens caused the narrowing of the opening area, increased flow velocity and turbulent head loss, and increased drawdown.
 It has been revealed that the use of a horizontal oblong slot screen minimizes the head loss in the wells, depending on the physical properties of the gravel used in this study. One of the most important factors to be considered in well designs is the compatibility of the screen type depending on the physical properties of the gravel. Even the change of the geometric shape among the screen types having similar apertures changed the blockage of the gravel, causing the head loss to change. The well-designers should pay attention to the selection of gravel depending on the screen type or the selection of the screen depending on the type of gravel used.

Maximum energy loss in a vertical drop equipped with horizontal screen with downstream rough and smooth bed

Abstract Screens are one of the recent energy dissipator structures that can be used downstream of small hydraulic structures. In this study, screens were used horizontally at the brinks of the vertical drop with downstream smooth and rough bed to investigate the energy loss of the drop. Experiments were performed on two porosities of screens, a relative critical depth of 0.13–0.39 and a median size of 1.9 cm aggregates. The results showed that for a relative critical depth of more than 0.3 in a vertical drop equipped with a screen with a rough bed, the drop length with respect to smooth bed increases. Compared to applying a Type I stilling basin, a vertical drop equipped with a screen with downstream smooth and rough bed reduces the drop length by approximately 50%. Although a rough bed increases air entrainment, it has no effect on the energy loss and pool depth of a vertical drop equipped with a horizontal screen with smooth bed. The use of horizontal screens at the brinks of the vertical drop causes maximum energy loss in the downstream of drop. Equations were provided to estimate the flow parameters with a R2 value of more than 0.925 and a normalized root mean square error of less than 0.04.

Technical advances in well type and drilling & completion for high-efficient development of coalbed methane in China

Compared with the United States, Australia, Canada, and other countries, China's coalbed methane reservoir is featured by low formation pressure, low permeability, low gas saturation, and strong heterogeneity, which not only increases the difficulty of reservoir stimulation but also restricts the single well production and the recovery efficiency of coalbed methane (CBM). In view of this, the research and application of horizontal drilling and completion technology of CBM at home and abroad are reviewed to provide references and theoretical supports for the advancement of the horizontal well engineering technology of CBM in China. This paper introduces a series of horizontal drilling and completion technologies (e.g., the well type design, well structure optimization, well trajectory control, wellbore stability, completion optimization, reservoir protection, etc.). The advanced technologies and their adaptability, including screen pipe completion and stimulation with dual-layer tubular strings, radial horizontal well screen pipe completion and magnetic steering drilling, are dialectically discussed in this paper. In addition, a novel integrated engineering mode for the efficient and green development of deep CBM and coal through the underground “well factory” is proposed. The conclusions are as follows: (1) In view of the geological conditions and surface environment of the coal seam in China, the horizontal drilling and completion technologies of high rank coalbed methane should be further refined, and an integrated development for the coal measure gas is required; (2) More efforts should be made to strengthen the innovative research on horizontal drilling & completion technology for low-medium rank coals and the broken coal, so as to identify the efficient development mode for the complex coalbed methane reservoir; (3) When encountering major technical challenges during the green and efficient development of unconventional coal mines such as deep coal mines, low grade coal mines and thin coal seams in China, it is necessary to explore the development mode via in-situ conversion process based on underground “well factory” to realize the integrated green and efficient development of deep CBM and coal; (4) The high quality transformation with low-carbon and green energy in China will not only ensure national energy security, but also achieve the goal of “carbon peaking and carbon neutrality”.

A Note of Caution on Distorted Visual Feedback as a Treatment for Functional Movement Disorders.

A Note of Caution on Distorted Visual Feedback as a Treatment for Functional Movement Disorders.

Numerical and experimental investigation of heat transfer across semi-transparent horizontal screen layers

Estimating the total heat flux passing through layers of materials is commonly used to determine the performance and potential of thermal isolation for general building design. The thermal properties of building glazing have been studied theoretically and experimentally for several decade. In this study, an enhanced algorithm for calculating the heat transfer through semi-transparent screens was developed and validated via published data and in-site experiments in order to analyze thermal properties of different screen materials and their combinations under more realistic conditions. The proposed algorithm allows to simplify the linearization of a nonlinear system, which is solved by inverting a tridiagonal matrix. Overall heat transfer coefficients (U-values) for single and multiple thin-screens were calculated numerically and measured using the hot-box method. The building insulating materials such as glass, polymers, aluminium films, and selected commercial thermal screens were examined. The cross-validated results indicated good agreement between calculated, measured and previously published results demonstrating the abilities of the method to predict new data for materials and their combinations that have not yet been estimated. Moreover, the algorithm allows to adopt the experimentally validated results to real ambient conditions by applying relevant scaling methods. The following results demonstrate the insulation properties of various commercial thermal screens. It is found that U-values reduce by 30% and 15% for the combination of a glass screen with an additional layer of a transparent infra-red (IR) radiation absorbing screen and a polyethylene screen, respectively. In comparison, the contributions of an additional screen containing aluminium foil strips could reduce the U-value by about 80% and 70% for polyethylene and glass cover screen, respectively. It was confirmed that low-emissivity materials have a more significant effect on reducing the U-value than insulating materials with IR-absorbing properties. The approach is valid for investigating the performance of thermal insulation in different enclosures, glazing in buildings, or moveable thermal screens in greenhouses.

42.3: Invited Paper: Design of Double Vertical Screen 3D Viewer and Mobile Phone 3D Glasses

Based on the principle of non‐paraxial optics and through accurate calculation, an eccentric lens is designed which is specially used for viewing the stereoscopic image with two vertical screens composed of two mobile phones. If it is made into glasses, called them “stereoscopic glasses for mobile phone”. If the display screen and stereoscopic glasses are packaged together, it is called “stereoscopic viewer with double vertical screens”, It corresponds to the previous “ stereoscopic viewer with double side horizontal screen o The former mainly watches stereoscopic images taken vertically, such as personal stereoscopic photo, remote stereoscopic medical treatment, precious cultural relics collection, etc., while the latter matches the 16:9 standard film and television taken horizontally. Mobile phone stereoscopic glasses can not only watch two vertical screen stereoscopic programs, but also watch left and right side‐by‐side programs on the screen of one mobile phone. It is easy to carry and has good imaging quality with no dizziness. It comes with 4G and 5G system, and the price of 3D viewing device is low. Therefore it is expected to become the standard configuration of mobile phones.

Predicting relative energy dissipation for vertical drops equipped with a horizontal screen using soft computing techniques

AbstractThis study was designed to evaluate the ability of Artificial Intelligence (AI) methods including ANN, ANFIS, GRNN, SVM, GP, LR, and MLR to predict the relative energy dissipation (ΔE/Eu) for vertical drops equipped with a horizontal screen. For this study, 108 experiments were carried out to investigate energy dissipation. In the experiments, the discharge rate, drop height, and porosity of the screens were varied. Parameters yc/h, yd/yc, and p were input variables, and ΔE/Eu was the output variable. The efficiencies of the models were compared using the following metrics: correlation coefficient (CC), mean absolute error (MAE), root-mean-square error (RMSE), Normalized root mean square error (NRMSE) and Nash–Sutcliffe model efficiency (NSE). Results indicate that the performance of the ANFIS_gbellmf based model with a CC value of 0.9953, RMSE value of 0.0069, MAE value of 0.0042, NRMSE value as 0.0092 and NSE value as 0.9895 was superior to other applied models. Also, a linear regression yielded CC = 0.9933, RMSE = 0.0083, and MAE = 0.0067. This linear model outperformed multiple linear regression models. Results from a sensitivity study suggest that yc/h is the most effective parameter for predicting ΔE/Eu.

Research and Application of Segmentation Unblocking Technology for Horizontal Well Screen

Horizontal well screen completion process has its own advantages, but there are also some problems, in which the screen blockage seriously affects its efficacy. However, due to various factors (such as heavy components in crude oil plugging the sand filter), the implementation of conventional pickling and sand washing operations is not ideal. In response to this problem, this paper proposes a new unblocking technology - segmentation unblocking technology for horizontal well screen. Firstly, on the basis of studying principle of the technology, optimization of water jet method and hydraulic sanding nozzle, nitrogen foam water jet experiment and water jet construction displacement experiment are carried out for horizontal well screen, which laying the foundation for application of segmentation unblocking technology. Further, horizontal well screen segmentation unblocking experiment and oilfield application are carried out. Optimization results of water jet method show that, For large displacement construction with still wellhead, whole section construction selects type of inlet liquid through annulus between oil pipe and casing pipe and outlet liquid through oil pipe. For small displacement construction with frequent dynamic wellhead, segmentation construction selects type of inlet liquid through oil pipe and outlet liquid through annulus between oil pipe and casing pipe. Optimization results of hydraulic sanding nozzle show that Streamlined nozzle is better than nozzle with iso variable. Experiment results of horizontal well screen segmentation unblocking show that, segmentation unblocking technology can effectively improve productivity of horizontal well and oilfield application achieved good results. Five wells were shut-in, periodic shut-in or low production before segmentation unblocking. After segmentation unblocking, daily oil increment can reach 23.57 t, and interval cumulative oil increment can reach 4756 t.

Experimental study of the effect of horizontal screen diameter on hydraulic parameters of vertical drop

AbstractThe horizontal screen is one of the energy dissipater structures used on the brink of vertical drop. These structures increase the energy dissipation and the turbulence in the flow by causing air entrainment. In the present study, the effect of the diameter of the screen with constant porosity at three different diameters on the hydraulic parameters of the vertical drop was investigated. The experiments were performed in the relative critical depth range of 0.13 to 0.39. The results showed that by increasing the relative diameter of the horizontal screen, the relative wetting length and turbulence length increased, the residual energy remained constant and the pool depth decreased. Compared to the stilling basin, the horizontal screen significantly reduces turbulence length and residual energy. The results also showed that the application of horizontal screens at the brink of the drop, with and without a downstream rough bed, could be a suitable alternative for a stilling basin.

Investigating the Effect of Horizontal Screen on Hydraulic Parameters of Vertical Drop

In the present study, the behavior of hydraulic parameters is investigated for a vertical drop equipped with a horizontal screen. A total of 105 experiments were carried out over a range of parameters, which comprise pool depth, downstream depth, wetted length of the screen, relative mixing length, and energy dissipation with discharge variability of flow for three different drop heights and two porosity ratios. The results indicate that the use of horizontal screens in vertical drops can increase the relative pool depth, the relative downstream depth, and relative energy dissipation compared with a plain vertical drop. It was also found that screens significantly reduce the downstream Froude number from 3.7–6.1 to 0.67–1. A comparison of the porosity of the screens also indicates that the porosity of the screens has an insignificant effect on the performance of the vertical drop. An increase in the porosity of the screens reduces the relative wetted length of horizontal screens and the relative mixing length.

Intranasal Allopregnanolone Confers Rapid Seizure Protection: Evidence for Direct Nose-to-Brain Delivery

Allopregnanolone, a positive modulator of GABAA receptors with antiseizure activity, has potential in the treatment of seizure emergencies. Instillation of allopregnanolone in 40% sulfobutylether-β-cyclodextrin into the nose in mice rapidly elevated the seizure threshold in the timed intravenous pentylenetetrazol (ED50, 5.6 mg/kg), picrotoxin (ED50, 5.9 mg/kg), and bicuculline seizure tests. The effect peaked at 15 min, decayed over 1 h, and was still evident in some experiments at 6 h. Intranasal allopregnanolone also delayed the onset of seizures in the maximal PTZ test. At an allopregnanolone dose (16 mg/kg) that conferred comparable effects on seizure threshold as the benzodiazepines midazolam and diazepam (both at doses of 1 mg/kg), allopregnanolone caused minimal sedation or motor toxicity in the horizontal screen test whereas both benzodiazepines produced marked behavioral impairment. In addition, intranasal allopregnanolone failed to cause loss-of-righting reflex in most animals, but when the same dose was administered intramuscularly, all animals became impaired. Intranasal allopregnanolone (10 mg/kg) caused a rapid increase in brain allopregnanolone with a Tmax of ~5 min after initiation of the intranasal delivery. High levels of allopregnanolone were recovered in the olfactory bulb (Cmax, 16,000 ng/mg) whereas much lower levels (Cmax, 670 ng/mg) were present in the remainder of the brain. We conclude that the unique ability of intranasal allopregnanolone to protect against seizures without inducing behavioral adverse effects is due in part to direct nose-to-brain delivery, with preferential transport to brain regions relevant to seizures. Benzodiazepines are commonly administered intranasally for acute seizure therapy, including for the treatment of acute repetitive seizures, but are not transported from nose-to-brain. Intranasal allopregnanolone acts with greater speed, has less propensity for adverse effects, and has the ability to overcome benzodiazepine refractoriness. This is the first study demonstrating rapid functional central nervous system activity of a nose-to-brain-delivered steroid. Intranasal delivery circumvents the poor oral bioavailability of allopregnanolone providing a route of administration permitting its evaluation as a treatment for diverse neuropsychiatric indications.

Vibration Measurement of a Screening Machine

In this paper we use linear vibration approach to make a model of a horizontal vibration screen, which can be applied at gravel pit in order to perform separation operation of the wet gravel particles. The model can produce the natural frequencies of the system, which are useful in the adjustment of the angular velocity of the vibration exciter. A laser triangulation unit is well applicable to measure peak-to-peak amplitude of the working vibration screen. Comparison has been performed between the results of the simulation and the measurements.

Total Body Irradiation as Conditioning Regimen for Haematopoietic Progenitor Cell Transplant: A Case Report and Literature Review

This case study presents a young adult man with lymphoblastic leukaemia B who required total body irradiation (TBI) as a conditioning regimen for haematopoietic progenitor cell transplant (HPT) as the only curative treatment option for his oncological disease. TBI was carried out with personalised patient immobilisation, three-dimensional simulation, radiophysical planning and dosimetric calculations. A total of 12 Gy were prescribed to be administered twice a day for 3 days in a row by means of volumetric modulated intensity radiotherapy with several isocentres. The best technique for the administration of this radiotherapy is discussed because, although the clinical efficacy of the administration of this body dose has been well known for decades, technological advances have brought us new possibilities when compared to the traditional TBI (bilateral with horizontal photon beam and absorbent screen). These advances include the technique used in this case (multi-isocentre volumetric-radiotherapy), which allows a better doses distribution, reducing the dose in organs at risk (OARs) and producing less toxicity, and therefore allowing the inclusion of patients who would not tolerate a conventional TBI. In addition, this method would allow the dose to be scaled up locally in higher areas at risk with better results in the disease control.

Experimental Investigation of Performance of Horizontal and Vertical Screen on Energy Dissipation of Inclined Drop

Experimental Investigation of Performance of Horizontal and Vertical Screen on Energy Dissipation of Inclined Drop

Smart Insect Cameras

Recent studies have shown a worrying decline in the quantity and diversity of insects at a number of locations in Europe (Hallmann et al. 2017) and elsewhere (Lister and Garcia 2018). Although the downward trend that these studies show is clear, they are limited to certain insect groups and geographical locations. Most available studies (see overview in Sánchez-Bayo and Wyckhuys 2019) were performed in nature reserves, leaving rural and urban areas largely understudied. Most studies are based on the long-term collaborative efforts of entomologists and volunteers performing labor-intensive repeat measurements, inherently limiting the number of locations that can be monitored. We propose a monitoring network for insects in the Netherlands, consisting of a large number of smart insect cameras spread across nature, rural, and urban areas. The aim of the network is to provide a labor-extensive continuous monitoring of different insect groups. In addition, we aimed to develop the cameras at a relatively cheap price point so that cameras can be installed at a large number of locations and encourage participation by citizen science enthusiasts. The cameras are made smart with image processing, consisting of image enhancement, insect detection and species identification being performed, using deep learning based algorithms. The cameras take pictures of a screen, measuring ca. 30×40 cm, every 10 seconds, capturing insects that have landed on the screen (Fig. 1). Several screen setups were evaluated. Vertical screens were used to attract flying insects. Different screen colors and lighting at night, to attract night flying insects such as moths, were used. In addition two horizontal screen orientations were used (1) to emulate pan traps to attract several pollinator species (bees and hoverflies) and (2) to capture ground-based insects and arthropods such as beetles and spiders. Time sequences of images were analyzed semi-automatically, in the following way. First, single insects are outlined and cropped using boxes at every captured image. Then the cropped single insects in every image were preliminarily identified, using a previously developed deep-learning-based automatic species identification software, Nature Identification API (https://identify.biodiversityanalysis.nl). In the next step, single insects were linked between consecutive images using a tracking algorithm that uses screen position and the preliminary identifications. This step yields for every individual insect a linked series of outlines and preliminary identifications. The preliminary identifications for individual insects can differ between multiple captured images and were therefore combined into one identification using a fusing algorithm. The result of the algorithm is a series of tracks of individual insects with species identifications, which can be subsequently translated into an estimate of the counts of insects per species or species complexes. Here we show the first set of results acquired during the spring and summer of 2019. We will discuss practical experiences with setting up cameras in the field, including the effectiveness of the different set-ups. We will also show the effectiveness of using automatic species identification in the type of images that were acquired (see attached figure) and discuss to what extent individual species can be identified reliably. Finally, we will discuss the ecological information that can be extracted from the smart insect cameras.

Is the manual following response an attempt to compensate for inferred self-motion?

If the surrounding of a visual target unexpectedly starts to move during a fast goal-directed hand movement, the hand reflexively moves along with it. This is known as the ‘manual following response’. One explanation for this response is that it is a compensation for inferred self-motion in space. Previous studies have shown that background motion gives rise to both postural responses and deviations in goal-directed hand movements. To evaluate whether compensation for inferred self-motion is responsible for the manual responses we examined whether galvanic stimulation of the vestibular system would give rise to similar deviations in hand movements. Standing participants tried to quickly tap on targets that were presented on a horizontal screen. Participants could infer self-motion on some of the trials, either from galvanic vestibular stimulation or from background motion. Both perturbations took place during the hand movement. It took both the head and hand about 45 ms longer to respond to background motion than to respond to galvanic stimulation. The head responded in a similar manner to both types of perturbations. The hand responded about as expected to galvanic stimulation, but much more vigorously to background motion. Thus, the manual response to background motion is probably not a direct consequence of trying to compensate for inferred self-motion. Perhaps the manual following response is a consequence of an error in binding motion information to objects.

Research and application of gravel-packing flow-regulation water-control screen completion technique in horizontal wells

Horizontal well inflow control screen completion require packer to stage on the reservoir, however, the numbers of packer are limited to section of the reservoir, the reservoir sealing length is limited by packer rubber, effective sealing length is short, that restricts to the control precision of ICD in horizontal wells. In view of above, this paper presents a new horizontal well gravel packing inflow control screen completion technology, that uses gravel to replace the packer to seal the reservoir, resisting the transverse flow in the wellbore, making the inflow control screen can control water directly on formation in which the position is located, to realize the dynamic adjustment the flow profile in the whole horizontal well section. From the technological principle and characteristics, key implemental technology, gravel and supporting tools, construction technology and other aspects of horizontal well gravel filling, the gravel packing inflow control screen completion technology were studied. The technology was applied in adjustment horizontal well completion in the xinjiang A oilfield. After application, the oil production increased by 5.1 times, the water content decreased by 13.5%, and achieved a good effect of controlling water coning and increasing oil. The application results suggest that horizontal gravel inflow control screen pipe completion technology can improve the effect of inflow control screen completion, that could be applied in the new wells and old wells second completion.