Excessive Penetration Research Articles

Voltage Regulation in Excessive Penetration of Solar Rooftop Distribution System Using Battery Energy Storage System

This paper presents the methodology and solutions for mitigating voltage variation under steady conditions caused by differing levels of PV penetration in low-voltage (LV) rural networks. The LV rural area of the Provincial Electricity Authority (PEA) North-East area 3 District of Thailand is used as a case study with load profiles from Geographic Information System (GIS) software. Moreover, rooftop PV power generation is calculated using recorded data on irradiation in Nakhon Ratchasima Province. DIgSILENT Power Factory software is used to simulate and analyze the quality of the proposed method by focusing on the voltage level at the end of the line or dead-end (DE) of the LV network. The results show overvoltage at the DE under the high rooftop PV penetration. The battery energy storage system (BESS) is applied to mitigate the problem of low quality. Meanwhile, the system is operated by examining load demand and rooftop PV power generation to define the state of charging and discharging conditions. The proposed method can be integrated into the algorithm of a rooftop PV system and BESS local control in the home energy management system (HEMS). The results show that the proposed method can reduce the voltage variation problem existing in the PEA standard while improving the voltage level at all DEs.

Consensus and sharing based distributed coordination of home energy management systems with demand response enabled baseboard heaters

The repercussions from excessive penetration of uncoordinated Home Energy Management Systems (HEMSs) have proven to be pernicious in the distribution system regarding contingencies, instabilities, and rebound peaks. This paper aims to design a distributed coordination technique with the required topology to coordinate transactive HEMSs with demand response enabled electric baseboard heater thermostats to avoid the detrimental effects of uncoordinated HEMSs in a residential group. Specifically, the proposed technique establishes a consensus to fulfill individual as well as shared objectives by modifying consumers’ consumption patterns. The shared objective is to flatten the aggregated profile and decrease the total cost in the grid. In addition, an incentive policy has been designed to pay a total reward to the team for encouraging consumers to participate in the coordination. The presented coordination technique comprises a Shapley game-based reward-sharing mechanism and an incentive-compatible mechanism, where the team’s gain is distributed among the players based on their contribution. Besides, the coordination leads to agents’ complementary decision-making and mitigates the grid challenges. The functionality and effectiveness of the proposed coordinated HEMSs algorithm are tested for a set of different case studies based on user preferences and coordination levels. The simulation results indicate that the proposed coordination improves aggregated profile’s load factor up to 0.85 and reduces the electricity bill by 21.4%.

Efficient Utilization of Macropores as Artificial Solid–Electrolyte Interphase Channels for High-Capacity Silicon/Graphite Anode Materials

Porous architectures for silicon/graphite (Si/Gr) composites can buffer the massive volume expansion of Si particles during electrochemical cycling. However, the large surface area derived from the high porosity leads to unavoidable side reactions at the electrode–electrolyte interface, leading to the formation of thick resistive natural solid–electrolyte interphase (SEI). Herein, a simple and scalable route is developed for coating a polymeric artificial SEI (A-SEI) inside the porous architecture for the Si/Gr composite via a facile incipient wetness impregnation (IWI) method. Cross-sectional focused ion beam microscopic results infer that the polymer coating is successful. Polymer coating for the porous matrix as A-SEI induces sufficient porosity as well as prevents excessive electrolyte penetration into the highly porous matrix. Furthermore, it prevents the direct contact of active materials with electrolytes, minimizing the parasitic reactions that form natural SEIs. Consequently, the polymer coating obtained by IWI enables remarkable enhancement in the long-cycle stability of the porous Si/Gr electrode, in contrast to the nonimpregnated electrode displaying capacity roll-over due to excessive SEI formation. Moreover, it is demonstrated that the coating effectively prevents the formation of dendritic lithium plating on the surface of the Si/Gr electrode, thereby enhancing the safety of the battery.

The effect of aeration on treatment efficiency and bioenergy generation of septic-tank effluent in constructed wetland-microbial fuel cell

This study examines the effect of different rates and modes of supplementary aeration on the treatment of synthetic septic tank effluent in a lab-scale unplanted constructed wetland-microbial fuel cell (CW-MFC) along with bioenergy generation. The experiment was conducted in 4 sequential phases; 1) the cell was operated with no aeration (NA), 2&3) the cathode layer was continuously aerated under different aeration rates (CA-I and CA-II), and 4) the cathode layer was intermittently aerated (IA). Results showed that the dissolved oxygen gradient caused by IA formed aerobic and anoxic zones in CW-MFC and promoted total nitrogen removal. The best performance was observed with intermittent aeration where the maximum removal efficiencies of COD (96.8 ± 3.3 %), TN (62.3 ± 2.1 %), TKN (68.3 ± 2.0 %), and NH3 (64.8 ± 2.3 %) were achieved. Furthermore, this treatment efficiency corresponded with enhanced bioenergy generation under the IA regime, achieving maximum power output (7.5 mW/m2), highest average voltage output (0.399 ± 0.02 V), Coulombic efficiency (1.94 %), and normalized energy recovery (1.4 Wh/m3). Continuous aeration, however, induced an adverse effect on energy generation due to excessive oxygen penetration into the anode region. Nitrate accumulation was also observed as a sign of an incomplete denitrification process under the continuous aeration regime. Overall, it can be concluded that the intermittently aerated CW-MFC not only lowers operational costs but improves effectiveness in terms of the nitrogen removal process in the treatment of septic tank effluent.

High-/Low-Molecular-Weight PDMS Photo-Copolymerized Membranes for Ethanol Recovery

Poly(dimethylsiloxane) (PDMS) is the benchmark of alcohol-selective membranes. The low-molecular-weight PDMS easily causes pore penetration and nonuniform coverage, thus PDMS membrane is generally fabricated by the high-molecular-weight chains (Mw ≥ 50,000). However, there are inevitably excessive chain entanglements in longer polymeric chains, limiting the transport of penetrating molecules. In this work, we proposed a high-/low-molecular-weight PDMS photo-copolymerized strategy to prepare a high-performance pervaporation membrane for ethanol recovery, which combines the advantages of high-/low-molecular-weight PDMS chains. The fluidity and polymerization efficiency are improved, while the excessive pore penetration is prevented. The result showed that the high-/low-molecular-weight PDMS mixed membranes display a superior comprehensive pervaporation performance for ethanol recovery in comparison with the other polymeric membranes. The copolymerized strategy is facile and shows a promising prospect for ethanol recovery.

The procedural form of judicial conciliation procedure: Concept, legal nature, principles

The article is devoted to the study of the legal nature of judicial conciliation procedures int he civil process. On the basis of a theoretical analysis of the approaches to the concept of “procedural form of protection” existing in the procedural doctrine, the essence of judicial conciliation procedure as a part of civil and arbitration proceedings is revealed. The difference between judicial conciliation and extrajudicial conciliation procedures is shown. The onto-logical connection of the fundamental principles of civil procedural form and judicial conciliation procedures is proved. Guided by the achievements of the science of civil and arbitration procedural law and the materials of the practice of arbitration courts, the authors establish the degree and limits of the impact of the imperative and dispositive principles of state proceedings on the order of organization, conduct and results of judicial conciliation procedures. It is concluded that the excessive penetration of freedom into the sphere of judicial reconciliation contradicts the essence of the civil process as a form of administration of justice and can lead to abuse both by the participants in the trial and by the court. It is proposed to consolidate at the legislative level the imperative procedure for organizing and conducting judicial conciliation, its stages and stages, requirements for the candidacy of a judge-conciliator, his rights and obligations, as well as responsibility for the results of judicial reconciliation. The results of judicial reconciliation, their legal consequences are analyzed. The features of judicial conciliation in proceedings on cases arising from administrative and other public legal relations, which are also proposed to be regulated, are revealed. It is proposed to comprehensively fix the grounds, conditions and legal consequences of the judicial conciliation procedure in the field of resolving public legal conflicts.

Analysis of Adhesive Distribution over Particles According to Their Size and Potential Savings from Particle Surface Determination

Wood and its processing into particles are, combined, the largest cost factor in the production of particleboard, followed by the cost of adhesive. Thus, reducing their cost is a goal of process optimization. This study investigated whether possible savings could be identified and quantified by determining the particle surface using automated three-dimensional laser-scanning technology (3D Particleview, Fagus-Grecon). The focus was on saving adhesive by sieving out adhesive-consuming fines. It was shown that, currently, with the actual prices for wood (89 €/t), particle preparation (37 €/t), and adhesive (570 €/t), the resulting additional costs for particles are overcompensated by the savings for adhesive with high adhesive content (e.g., 19%). The assumption of uniform distribution of adhesive on the total surface of all particles was checked for correctness using digital reflected light microscopy (VHX-5000, Keyence). Since urea-formaldehyde (UF) adhesive commonly used in particleboard production can only be detected with increased effort, phenol-formaldehyde (PF) adhesive was applied for the tests. Ultraviolet microspectrophotometry (UMSP) was used to rule out excessive penetration of the adhesive into the wooden tissue of the particles. The examination of the distribution of the adhesive over the surface showed that smaller particle sizes tended to be more heavily coated with adhesive. This means that the calculated savings still underestimate the real-life potential or that potential savings exist even with lower adhesive prices or higher prices for wood.

The Volar Midline Longitudinal Groove of the Middle Phalanx: An Anatomic Study and Clinical Implications

To investigate the volar anatomy of the middle phalanges of the hand; in particular, to define the presence and depth of a volar midline longitudinal groove. Measurements were performed at 5 equidistant points along the shafts of 60 skeletonized middle phalanges from 15 cadaveric hands. The thickness at the midline of each phalanx was subtracted from the maximal dorsovolar thickness to indicate the presence or absence of a groove at each point. The phalanges were also evaluated by computed tomography to confirm the presence of a volar groove and to rule out morphological abnormalities. A volar groove was confirmed in all 60 phalanges. The groove had an average depth of 0.4 mm and was found to be deepest at the mid-phalangeal shaft. The groove reached a depth of greater than 1 mm in 23% of the phalanges. The middle phalanges of the middle and ring digits consistently revealed deeper grooves than those found in the index and little fingers. Computed tomography confirmed the presence of a volar groove and showed no morphological abnormalities. A midline volar longitudinal groove is present in the middle phalanges, is most pronounced in the mid-phalangeal shaft, and is the deepest in the middle and ring fingers. Surgeons should be cognizant of the volar longitudinal groove when inserting screws from dorsal to volar during the fixation of middle phalangeal fractures. Lateral intraoperative fluoroscopy may not reveal excessive screw penetration because of the presence of ridges on either side of the groove. Particular care should be taken at the mid-phalangeal level of the middle phalanges of the middle and ring fingers.

Zinc oxide nanoparticles as additives for improved dimensional accuracy in vat photopolymerization

To improve the dimensional accuracy of 3D printed parts produced by vat photopolymerization, a controlled light penetration through the photopolymer resin is necessary to avoid excessive unwanted curing caused by overexposure. Although photoabsorbing additives like Sudan I can attenuate light to decrease excessive light penetration, they also require longer exposure time to solidify the resin. In this work, photocatalytic zinc oxide nanoparticles (ZnONP) were used as resin additives substituting photoabsorbers to control overexposure that causes loss in dimensional accuracy. Compared to adding 0.1 wt/wt% of Sudan I, adding 2.5 wt/wt% of ZnONP not only showed similar level of control in light penetration, but reduced the required curing time of the resin. Significant improvement in preventing unwanted curing was also observed in resin with ZnONP, as evident by our printing tests on open channels and overhanging structures. Unlike Sudan I which deteriorated the mechanical properties of printed parts, ZnONP additives have rendered more effective curing that resulted in improved tensile strength, fracture strain and Young’s modulus.

Penetration Recognition in GTAW Welding Based on Time and Spectrum Images of Arc Sound Using Deep Learning Method

The weld penetration rate is an important evaluation criterion for welding quality. However, it is difficult to identify the weld penetration state during GTAW welding process. This paper presents a new penetration recognition method based on time and spectrum images of arc sound using deep learning for DC GTAW welding. The time domain and spectrum images of the three penetration states from the non-periodic arc sound were used as the dataset for the penetration prediction model. VGG16, AlexNet, and custom convolutional neural network (CNN) were used to extract image features, and softmax was used to classify images for penetration recognition. The influence of image feature extraction networks, input methods, and different sampling methods on the recognition accuracy was deeply analyzed. The results show that the overall validation accuracy of the proposed model is approximately 96.2%. Particularly, the validation accuracy of the model in the excessive penetration state is approximately 100%. This study provides a new and feasible method for the online detection of weld penetration during the GTAW welding process.

Effect of Welding Parameter Conditions of 304L SS and AISI 1015 Dissimilar Steel Weld Joints to Macrostructure and Mechanical Properties

This research is focused on the effect of welding parameter conditions, using Gas Metal Arc Welding, on the macrostructure, mechanical properties, and quality of dissimilar steel weld joints. In this study, the selected joints were low carbon steel (AISI 1015) and austenitic stainless steel (304L SS). The welding current used had three different variations, such as 100, 110, and 120 A. The solid wire electrode used was ER70S6, with a diameter of 1.2 mm. Identification of the macrostructure in the heat-affected zone (HAZ), micro-Vickers hardness, and tensile tests carried out for each GMAW joint specimen. The results were then discussed. The macrostructure of dissimilar steel welded joints at a welding current of 100 A produced a good quality of welded joints and penetration compared to those using welding currents of 110 and 120 A, which had excessive penetration and caused distortion and deformation. The microhardness of the weld metal area was far higher than in other areas. At the current 100 A, the micro-Vickers hardness value of stainless steel 304L SS closing the heat-affected zone (HAZ) had increased from 209 to 226 HV. Likewise, For the welding current of 110 A, the micro-Vickers hardness value rose from 249 to 259 HV, and for the welding current of 120 A, the hardness increased from 225 to 227 HV. In the weld metal area, micro-Vickers hardness for each welding current was 318, 364, and 366 HV, while in the low carbon steel area, the hardness value decreased significantly to 180, 190, and 196 HV. At the current of 100 A, the lowest tensile strength was 359.28 MPa, and yield strength was 303.82 MPa. The tensile strength and yield strength for the current of 110 A were 367.24 MPa and 309.83 MPa, respectively. Meanwhile, at the current of 120A, the tensile strength was at the highest that is 374.86 MPa, and the yield strength value was 315.67 MPa. This study found that the dissimilar steel welded joints experienced an increase in the hardness value of the weld metal, and the tensile test results show that the welded steel joints fractured in the low carbon steel area.

Liquid–liquid interface induced PDMS‐PTFE composite membrane for ethanol perm‐selective pervaporation

AbstractPervaporation has great potential in the separation of many significant mixtures. However, excessive penetration of separation layer into the substrate pores enhances the transport resistance of solvent molecules, which impedes the development of pervaporation membrane. In this study, a facile floating‐on‐water (FOW) method was used to prepare poly(dimethylsiloxane) (PDMS)/polytetrafluoroethylene (PTFE) composite membranes. The formation of separation layer and preparation of composite membrane were step‐by‐step completed through this liquid–liquid interface induced method. The PDMS layer thickness could be precisely regulated from 0.5 to 8 μm. Moreover, the pore penetration could be controlled by optimizing pre‐crosslinking density, crosslinking time on water and polymer solution volume. The obtained PDMS/PTFE composite membrane exhibited a high flux of 2016 g·m−2·h−1 with the separation factor of 12 when separating ethanol from a 5 wt% ethanol/water mixture. The performance of the membrane could be stable for over 200 h, exhibiting great potential in ethanol perm‐selective pervaporation.

Effect of electric parameters on weld pool dynamic behavior in GTAW

Assembling robot with human welder's intelligence is a good way to rapidly realize intelligent welding manufacturing. How to finely and accurately control dynamic weld pool, however, is a key issue for the intelligent robotic welding. To this end, an improved experimental system is built to simultaneously sense the weld pool dynamics and the electric parameters. The ROI signal of reflection laser images was obtained by a novel image processing algorithm, and the correlation between the weld penetration and the ROI signal was further established. The human welder's responses on the weld pool were detailly analyzed by the experiments with varying electric parameter. The effect of the electric parameters on the weld pool equilibrium was also studied by the established model which included the latent heat of phase change. The results indicate that the welding current, welding speed and arc length mainly changes the heat input to the weld pool, and easily loses its stability, resulting in a lack of penetration or excessive penetration. The fastest change of the weld pool occurs on the adjustment of the welding current, and the weakest change of the weld penetration happens in the adjustment of the arc length. Simulations ensure that the new equilibrium of the weld pool can be achieved within 1.8 s via adjusting the welding current, within 2.1 s via adjusting the welding speed, within 8 s via adjusting the arc length, respectively, which might be used to optimize the intelligentized controller and improve the accurate of the human welder's intelligence model.

Defective perlecan-associated basement membrane regeneration and altered modulation of transforming growth factor beta in corneal fibrosis.

In the cornea, the epithelial basement membrane (EBM) and corneal endothelial Descemet's basement membrane (DBM) critically regulate the localization, availability and, therefore, the functions of transforming growth factor (TGF)β1, TGFβ2, and platelet-derived growth factors (PDGF) that modulate myofibroblast development. Defective regeneration of the EBM, and notably diminished perlecan incorporation, occurs via several mechanisms and results in excessive and prolonged penetration of pro-fibrotic growth factors into the stroma. These growth factors drive mature myofibroblast development from both corneal fibroblasts and bone marrow-derived fibrocytes, and then the persistence of these myofibroblasts and the disordered collagens and other matrix materials they produce to generate stromal scarring fibrosis. Corneal stromal fibrosis often resolves completely if the inciting factor is removed and the BM regenerates. Similar defects in BM regeneration are likely associated with the development of fibrosis in other organs where perlecan has a critical role in the modulation of signaling by TGFβ1 and TGFβ2. Other BM components, such as collagen type IV and collagen type XIII, are also critical regulators of TGF beta (and other growth factors) in the cornea and other organs. After injury, BM components are dynamically secreted and assembled through the cooperation of neighboring cells-for example, the epithelial cells and keratocytes for the corneal EBM and corneal endothelial cells and keratocytes for the corneal DBM. One of the most critical functions of these reassembled BMs in all organs is to modulate the pro-fibrotic effects of TGFβs, PDGFs and other growth factors between tissues that comprise the organ.

Advanced control strategy to maximize view and control discomforting glare: a complex adaptive façade

ABSTRACT Increasing demands for full-glazed façades have motivated designers/researchers to propose advanced control strategies for dynamic shading systems to mitigate the negative impacts of excessive sunlight penetration into interior spaces. Nevertheless, in line with the latter, outside view is commonly obstructed as a result of utilizing conventional shading systems including Venetian blinds. This is primarily the consequence of conventional systems’ lack of flexibility to respond appropriately to occupants’ requirements and the sun's changing orientation. This paper presents the virtual prototype development of a Multi-layer blind system through a brute-force algorithm. It emphasizes proposing a customizable and affordable complex shading system with advanced control strategies for multiple building typologies. The research intends to improve visual comfort (daylight and glare) and maximize unblocked window view in a single office room located in Tehran. Furthermore, the control system was developed based on a combination of the cut-off and a glare protection control strategy. Concerning the cut-off control system, the slat angles change to block direct sun radiations, and then, if needed, the position of the front slat, named ‘View slat’, changes to avoid discomforting glare. In conclusion, the proposed prototype could improve daylight performance by up to 44% and maximize unobstructed outdoor view by approximately 47% in an almost glare-free zone. Finally, the usage of swarm intelligence could significantly improve the performance of the proposed prototype by determining which blind and how they should respond to environmental changes and occupants’ requirements.

Prediction of penetration based on plasma plume and spectrum characteristics in laser welding

The plasma characteristics generated in laser welding are closely related to the weld penetration state and the resultant weld properties. In this paper, a real-time monitoring platform was built to monitor the plasma plume and spectral in laser deep penetration welding of the H340LA high-strength steel tailor rolled blanks. The image processing method and the spectral processing method were used to investigate the correlation of the penetration on the plasma plume and spectral. The weld penetration state was divided into three categories: excessive penetration, moderate penetration and partial penetration. It was found that the penetration was mainly affected by centroid height, plasma area and intensity. The weld gradually transitioned from partial penetration, moderate penetration to excessive penetration with the centroid height, plasma area and spectral intensity decreased. When the centroid height was 2.42–4.19 mm, the area was 6.96–17.58 mm2, and the spectral intensity was 447.98–1453.95 a.u., moderate penetration weld can be obtained. A plasma plume-spectrum based multi-features Back Propagation (BP) neural network model was purposed to predict the weld penetration state with an accuracy of 97%, which is greatly higher than that of the single-feature neural network model. This work provides technical guidance for realizing real-time control of weld penetration.

Root cause failure investigation of a boiler waterwall tube employed in a 325 MW thermal power plant: Caustic corrosion phenomenon and its effects

This paper focuses on failure analysis of a boiler waterwall tube, ASTM A213 Grade T2 steel, used in a 325 MW fuel oil-fired thermal power plant. The influence of fire/waterside factors on the failure was identified through multiple characterization techniques. Preliminary macroscopic observations revealed uniform heavy deposition and repair welding indications on the fireside surface of the failed tube. Moreover, a longitudinally hemielliptical inner groove along with excessive weld metal penetration and discrete cavities were observed along the crown of the tube, leading to local wall thinning down to around 50% of its nominal thickness. No noticeable hardness and microstructural variations such as pearlite colonies decomposition caused by long term overheating and formation of decarburized layer were detected. According to the results of micro-zone analyses, considerable quantity of sodium vanadium oxide compounds accumulated throughout the fireside surface of the tube was due to poor fuel quality used. The authors postulated that evaporation at the waterline of the approximately filled tube resulted in water/steam stratification and localized caustic constituents concentration within the inner groove like NaOH and alkaline producing salts containing Na, Mg, Ca and P elements entered into the water/steam cycle through condenser copper-based tube leakages. This trend solubilized protective magnetite film locally and, consequently, triggered caustic corrosion of the bare steel.

Pervaporation Membranes for Seawater Desalination Based on Geo-rGO-TiO2 Nanocomposites. Part 1: Microstructure Properties.

This is the first of two papers about the synthesis and microstructure properties of the Geo–rGO–TiO2 ternary nanocomposite, which was designed to suit the criteria of a pervaporation membrane for seawater desalination. The performance and capability of Geo–rGO–TiO2 as a seawater desalination pervaporation membrane are described in the second paper. A geopolymer made from alkali-activated metakaolin was utilized as a binder for the rGO-TiO2 nanocomposite. A modified Hummer’s method was used to synthesize graphene oxide (GO), and a hydrothermal procedure on GO produced reduced graphene oxide (rGO). The adopted approach yielded high-quality GO and rGO, based on Raman spectra results. The nanolayered structure of GO and rGO is revealed by Transmission Electron Microscopy (TEM) images. The Geo–rGO–TiO2 ternary nanocomposite was created by dispersing rGO nanosheets and TiO2 nanoparticles into geopolymer paste and stirring it for several minutes. The mixture was then cured in a sealed mold at 70 °C for one hour. After being demolded, the materials were kept for 28 days before being characterized. Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) measurements revealed that the geopolymer matrix efficiently bonded the rGO and TiO2, creating nanocomposites. Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) was used to examine the morphology of the outer layer and cross-sections of nanocomposites, and the results displayed that rGO were stacked on the surface as well as in the bulk of the geopolymer and will potentially function as nanochannels with a width of around 0.36 nm, while TiO2 NPs covered the majority of the geopolymer matrix, assisting in anti-biofouling of the membranes. The pores structure of the Geo–rGO–TiO2 were classified as micro–meso pores using the Brunauer–Emmet–Teller (BET) method, indicating that they are appropriate for use as pervaporation membranes. The mechanical strength of the membranes was found to be adequate to withstand high water pressure during the pervaporation process. The addition of rGO and TiO2 NPs was found to improve the hyropobicity of the Geo–rGO–TiO2 nanocomposite, preventing excessive seawater penetration into the membrane during the pervaporation process. The results of this study elucidate that the Geo–rGO–TiO2 nanocomposite has a lot of potential for application as a pervaporation membrane for seawater desalination because all of the initial components are widely available and inexpensive.

The effect of excessive penetration of welding on sand erosion pattern due to high speed gas-solid flows in elbows and reducers

The aim of the current study is to investigate the effect of excessive penetration of welding and natural gas impurity particles on increasing erosion in elbows and reducers. To this end Euler–Lagrange model is used to simulate the two-phase solid–gas flow, the Discrete Phase Model (DPM), k-ε turbulent model and DNV erosion model are used to model the solid particles, natural gas flow and erosion rate, respectively. Erosion in elbows occurs downstream of vertical welding while in reducers is weaker and occurs at the inlet. The results show that erosion rate increases by increasing excessive penetration, particles size, particles flow rate and natural gas flow rate. The effect of excessive penetration becomes more important in high speed flows containing solid particles, in such a way that reducing excess penetration from h = 3 mm to h = 0 mm, causes 45% reduction in erosion rate in elbows containing 20 m/s natural gas flows. Therefore, for high velocity impure gas flows, it is recommended to reduce the allowable excessive penetration in welding standards.

Impact and assessment of the overvoltage mitigation methods in low‐voltage distribution networks with excessive penetration of PV systems: A review

Impact and assessment of the overvoltage mitigation methods in low‐voltage distribution networks with excessive penetration of PV systems: A review