Breakdown Stress Research Articles

High-power test results for a cylindrical-shell silicon carbide higher-order-mode damper

The next high-current Electron-Ion Collider (EIC) is a new accelerator to be built at Brookhaven National Laboratory in collaboration with Thomas Jefferson National Accelerator Facility. In the EIC Electron Storage Ring (ESR), there will be beam currents of up to 2.5 A, which will excite massive higher-order-mode (HOM) power in the 17 single-cell 591 MHz superconducting radio-frequency (SRF) cavities. Damping the HOM power in the ESR SRF cavities is a challenge. A room temperature cylindrical shell shape silicon carbide (SiC) beamline HOM absorber (BLA) was chosen as the baseline design, due to its broadband and high-power capability, and previous demonstrations at other accelerator facilities, albeit at much lower power. Because the EIC BLA HOM power dissipation is significantly greater than the previous applications, it is imperative to carry out high-power testing to determine the maximum device performance levels achievable for thermal transport, rf breakdown, and mechanical stress, prior to finalizing the design. A SiC HOM absorber with a state-of-the-art geometry size was prototyped to verify the shrink-fit technique, test outgassing rate, and high-power handling capability. This paper presents the HOM damper’s prototyping and test results. Published by the American Physical Society 2024

Preparation of bionic nacre by “freezing‐mineralization” and their electrical, thermal, and mechanical properties

AbstractNatural nacre has attracted a lot of attention due to its superior mechanical properties. It is generally made up of 95% flake calcium carbonate and 5% organic matter. In this work, we prepared the bionic nacre material using the “freezing‐mineralization” method. The bionic material exhibits a microstructure that is quite similar to that of natural material and shows a high dielectric constant. The thermal conductivity in the in‐plane direction reaches 1.15 W/(m•K) at ambient temperature, which is 2.25 times higher than the out‐of‐plane direction's, clearly demonstrating an anisotropic behavior. Additionally, the mechanical performance of the biomimetic material can be on par with that of natural materials with a maximum breakdown stress of 51.4 MPa. Our results prove that the “freezing‐mineralization” method is essential to developing bionic nacre materials.

The Benefits of a Multimechanistic Antiaging Skin Technology.

Facial aging is a multifactorial phenomenon due to poor skin hydration, deficient intercellular communication, collagen/elastin breakdown, and oxidative stress. The objective of this study was to assess the efficacy of a multimechanistic antiaging prototype formulation on the appearance of photoaged facial skin after 24weeks of twice daily use. Fifty female subjects 35-65years of age of all Fitzpatrick skin types with mild to moderate facial photoaging concerns (fine lines, wrinkles, sagging skin, tone and texture) were enrolled in this monadic study. Investigator and subject tolerability assessments were performed along with facial noninvasive corneometry hydration and elasticity measurements. The dermatologist investigator assessed fine lines, wrinkles, skin evenness, radiance, plumping, texture/smoothness, sagging/firming/lifting, and global appearance on a 5-point ordinal scale. Forty-seven of the 50 subjects completed the study with a 19% increase in skin firmness and a 35% increase in skin hydration via bio-instrumentation readings after 24weeks of study product use. The investigator assessed a 40% improvement in lines, a 23% improvement in wrinkles, a 42% improvement in evenness, a 64% improvement in radiance, a 58% improvement in plumping, a 65% improvement in texture, a 60% improvement in firmness, and a 45% improvement in overall appearance at 24weeks. The serum combination of humectants, peptides, and antioxidants yielded excellent tolerability with visual and mechanistic skin improvement beginning at 1week with cumulative continuing improvement through 24weeks of use in terms of hydration, firmness, texture, radiance, and fine lines.

Synthesis and evaluation of antibacterial activity of transition metal-oleoyl amide complexes

Recent studies show that some metal ions, injure microbial cells in various ways due to membrane breakdown, protein malfunction, and oxidative stress. Metal complexes are suited for creating novel antibacterial medications due to their distinct mechanisms of action and the variety of three-dimensional geometries they can acquire. In this Perspective, the present study focused on new antibacterial strategies based on metal oleoyl amide complexes. Thus, oleoyl amides ligand (fatty hydroxamic acid and fatty hydrazide hydrate) with the transition metal ions named Ag (I), Co (II), Cu (II), Ni (II) and Sn (II) complexes were successfully synthesized in this study. The metals- oleoyl amide were characterized using elemental analysis, and fourier transforms infrared (FTIR) spectroscopy. The antibacterial effect of metals- oleoyl amide complexes was investigated for Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) by analysing minimum inhibitory concentration (MIC), minimal bactericidal concentration (MBC), and scanning electron microscopy (SEM). The results showed that metal-oleoyl amide complexes have high antibacterial activity at low concentrations. This study inferred that metal oleoyl amide complexes could be utilised as a promising therapeutic antibacterial agent.

Experimental Study on Critical Parameters Degradation of Nano PDSOI MOSFET under TDDB Stress.

In today's digital circuits, Si-based MOS devices have become the most widely used technology in medical, military, aerospace, and aviation due to their advantages of mature technology, high performance, and low cost. With the continuous integration of transistors, the characteristic size of MOSFETs is shrinking. Time-dependent dielectric electrical breakdown (TDDB) is still a key reliability problem of MOSFETs in recent years. Many researchers focus on the TDDB life of advanced devices and the mechanism of oxide damage, ignoring the impact of the TDDB effect on device parameters. Therefore, in this paper, the critical parameters of partially depleted silicon-on-insulator (PDSOI) under time-dependent dielectric electrical breakdown (TDDB) stress are studied. By applying the TDDB acceleration stress experiment, we obtained the degradation of the devices' critical parameters including transfer characteristic curves, threshold voltage, off-state leakage current, and the TDDB lifetime. The results show that TDDB acceleration stress will lead to the accumulation of negative charge in the gate oxide. The negative charge affects the electric field distribution. The transfer curves of the devices are positively shifted, as is the threshold voltage. Comparing the experimental data of I/O and Core devices, we can conclude that the ultra-thin gate oxide device's electrical characteristics are barely affected by the TDDB stress, while the opposite is true for a thick-gate oxide device.

Optimization of hydraulically amplified electrostatic actuators based on an evolutionary strategy and finite element model to match the performance of the human triceps surae muscle fibres

Artificial muscles are required to improve prosthetics, exoskeletons and other industrial robotics applications. Compared to other technologies like pneumatic actuators and shape memory alloys, Peano hydraulically amplified self-healing electrostatic (HASEL) actuators have the most similar stress output, work density and specific energy as biological muscle. This work designs an artificial muscle fibre that simulates human triceps surae muscle fibre using Peano-HASEL actuators. Analytical models are derived to calculate the capacitance and efficiency of the actuator. A three-stage methodology of an evolutionary strategy, finite element (FE) model and a severity analysis is proposed to optimize the geometrical parameters of the artificial muscle fibre, evaluate its performance, and identify potential risks. The finite element model created in this work produces a full multi-physics simulation coupling the electro-mechanical and fluid–solid interactions, which fits any liquid dielectric volume and for the first time simulates an entire activation cycle. The finite element model further simulates the force-length and force-velocity relationships not seen in previous work and facilitates understanding of the dynamics of the Peano-HASEL actuator, including damping characteristics. Plastic deformation and fluid pocket phenomenon due to materials are found during the simulation, which could give new insights for the analysis of electrical breakdown and mechanical stress failure. The three-stage design methodology described in this paper suggested that an artificial muscle with 80 mm width, 0.4 radian initial central angle, 20 um film thickness and 7.6 kV activation voltage would best match the human triceps surae muscle behaviour. The designed artificial muscle fibre can produce 80% of peak maximum strain (∼18.8%), have an efficiency of 22%, generate high loads within 5% strain and restore muscle-like performance beyond 5% strain.

The Influence of Extended Defects in 4H-SiC Epitaxial Layers on Gate Oxide Performance and Reliability

For the ongoing commercialization of power devices based on 4H-SiC, increasing the yield and improving the reliability of these devices is becoming more and more important. In this investigation, gate oxide on 4H-SiC was examined by time-zero dielectric breakdown (TZDB) and constant current stress (CCS) time-dependent dielectric breakdown (TDDB) method in order to get insights into the influence of the epitaxial defects on the gate oxide performance and reliability. For that purpose, MOS capacitors with different gate oxides have been fabricated. Crystal defects in the epitaxial layers have been detected and mapped by ultraviolet photoluminescence (UVPL) and interference contrast (DIC) imaging. The results of the comparison of electrical data and surface mapping data indicate a negative influence on the leakage current behavior for some extended epitaxial defects. Results from TDDB measurement indicated numerous extrinsic defects, which can be traced back to gate oxide processing conditions and defect densities.

Revealing the Mechanism of the Bias Temperature Instability Effect of p-GaN Gate HEMTs by Time-Dependent Gate Breakdown Stress and Fast Sweeping Characterization.

The bias temperature instability (BTI) effect of p-GaN gate high-electron-mobility transistors (HEMTs) is a serious problem for reliability. To uncover the essential cause of this effect, in this paper, we precisely monitored the shifting process of the threshold voltage (VTH) of HEMTs under BTI stress by fast sweeping characterizations. The HEMTs without time-dependent gate breakdown (TDGB) stress featured a high VTH shift of 0.62 V. In contrast, the HEMT that underwent 424 s of TDGB stress clearly saw a limited VTH shift of 0.16 V. The mechanism is that the TDGB stress can induce a Schottky barrier lowering effect on the metal/p-GaN junction, thus boosting the hole injection from the gate metal to the p-GaN layer. This hole injection eventually improves the VTH stability by replenishing the holes lost under BTI stress. It is the first time that we experimentally proved that the BTI effect of p-GaN gate HEMTs was directly dominated by the gate Schottky barrier that impeded the hole supply to the p-GaN layer.

Mesenchymal and Neural Stem Cell-Derived Exosomes in Treating Alzheimer's Disease.

As the most common form of dementia and a progressive neurodegenerative disorder, Alzheimer's disease (AD) affects over 10% world population with age 65 and older. The disease is neuropathologically associated with progressive loss of neurons and synapses in specific brain regions, deposition of amyloid plaques and neurofibrillary tangles, neuroinflammation, blood-brain barrier (BBB) breakdown, mitochondrial dysfunction, and oxidative stress. Despite the intensive effort, there is still no cure for the disorder. Stem cell-derived exosomes hold great promise in treating various diseases, including AD, as they contain a variety of anti-apoptotic, anti-inflammatory, and antioxidant components. Moreover, stem cell-derived exosomes also promote neurogenesis and angiogenesis and can repair damaged BBB. In this review, we will first outline the major neuropathological features associated with AD; subsequently, a discussion of stem cells, stem cell-secreted exosomes, and the major exosome isolation methods will follow. We will then summarize the recent data involving the use of mesenchymal stem cell- or neural stem cell-derived exosomes in treating AD. Finally, we will briefly discuss the challenges, perspectives, and clinical trials using stem cell-derived exosomes for AD therapy.

Passivity Breakdown and Crack Propagation Mechanisms of Lean Duplex (UNS S32001) Stainless Steel Reinforcement in High Alkaline Solution Under Stress Corrosion Cracking

The passivity breakdown and subsequent stress corrosion cracking (SCC) of Type 2001 lean duplex stainless steel (UNS S32001) reinforcement were investigated in a highly alkaline environment containing chlorides at a low temperature. Electrochemical analysis and mechanical testing were utilized to characterize the passive film development. Fractographic analysis was performed, correlating microstructure and corrosion performance, to reveal preferential crack paths. A chloride threshold below 4 wt% Cl− for a high alkaline environment was elucidated, with pitting susceptibility factor values close to unity, having a threshold critical areal cation vacancy concentration for passivity breakdown close to the 1013 cm−2. Pit initiation leading to passivity breakdown and crack nucleation in 4 wt% Cl− was triggered for stresses above σy, developing a low-frequency peak (0.1 Hz to 0.01 Hz) of the cracking process. Current peak deconvolution demonstrated passivity breakdown was triggered by the intensification in the rate of Type II transient and exposure time, while an increase in transient amplitude was related to the crack propagation. The α phase served as a nucleation site for pits, whose propagation was arrested at the γ phase. Predominant intergranular-SCC morphology through the α/γ interface was developed following anodic dissolution given the more active nature of the α phase (most active path); minor transgranular-SCC propagated through γ phase when high-stress concentration was reached, corresponding to slip-step dissolution.

A multi-energy level agnostic approach for defect generation during TDDB stress

A multi-energy level agnostic model is used to examine defect generation during time-dependent dielectric breakdown stress. When considering distributed bond strengths, Monte Carlo simulations show that the distinctive power-law increase of the generated defects with stress time is attained. The rate is strongly influenced by the width of the distribution. The time to breakdown in DC and AC unipolar simulations is proportional to the fluence and energy of the injected carriers. These findings are in line with thin oxide breakdown measurements, which demonstrate a fluence and energy-driven process.

The effects of extreme climate on the invasive plant Gutenbergia cordifolia: implications for its future management in savannah ecosystems

The aim of this study was to assess the effects of varying water stress levels on morphological and physiological parameters of an invasive plant Gutenbergia cordifolia. The assessment was conducted in the screenhouse at the Nelson Mandela African Institution of Science and Technology following a completely randomized design (CRD). Both morphological and physiological parameters were variable under water stress levels. While the maximum (159 cm) and minimum (9 cm) plant heights for G. cordifolia were observed under flood and drought water stress respectively, its maximum root collar diameter of 5 mm and the minimum of 1.3 mm were observed under moderate flood and drought water stress respectively. Generally, the number of leaves was highest under moderate flood stress (194 leaves/plant), and lowest under drought stress (13 leaves/plant). Similarly, the largest and smallest leaf surface area of 9 × 103 and 1 × 103mm2 were observed under flood and drought water stress respectively due to G. cordifolia's tendency to retain water when exposed to water stress through a reduction in number of leaves and leaf surface area when under drought stress condition. While a decrease in leaf chlorophyll was observed across water stress levels with the lowest chlorophyll levels of 0.02 under drought water stress, an increase in leaf anthocyanin levels (0.29 Abs g.DM−1) was observed particularly under flood stress due to increased chlorophyll breakdown and plants' water stress, respectively. This study informs that extreme climatic events such as excessive floods will likely facilitate invasions by G. cordifolia leading to decreased biotic resistance of native communities in savanna rangelands. Efforts to manage G. cordifolia's effects in a changing climate must therefore include the development of strategies and action plans that account for catastrophic events like floods and drought.

A multi-energy level agnostic simulation approach to defect generation

Defect generation during time-dependent dielectric breakdown stress is investigated by a multi-energy level agnostic model. Monte Carlo simulations show that the characteristic power-law increase of the generated defects with stress time is readily obtained when considering distributed bond strengths. DC and AC unipolar simulations show the proportionality between the time-to-breakdown and the fluence and energy of the injected carriers. These results are consistent with the experimental observations of a fluence and energy-driven process in thin oxides.

Uji Kelayakan Minyak Biji Ketapang sebagai Bahan Isolasi Cair Transformator

The transformer is an electrical equipment that functions to change the voltage of alternating current from one level to another. Inside the transformer, especially the power transformer, there is transformer oil which functions as a coolant which transmits heat to the fins of the transformer as well as an arc extinguisher in case of sparks in the transformer windings. Transformer oil is generally obtained from petroleum which is decreasing over time and is less environmentally friendly so that other alternatives are needed to overcome it. This research on the feasibility of ketapang seed oil as a liquid transformer insulating material is intended to determine the feasibility of ketapang seed oil based on the permitted used transformer oil specifications (SPLN 49-1: 1982 and IEC 60296: 2012). This test is carried out by several types of tests, namely testing the moisture content, density, viscosity, and testing the oil breakdown stress. From the test results, it was obtained that the water content of ketapang seed oil was 10 mg/kg, the density value was 0,921 gram/cm3, the viscosity value was 14,665 cSt and the breakdown stress value was 68,9 kV. From these results, based on the new transformer liquid insulating oil specifications, ketapang seed oil still does not meet the standards seen from the density value of the oil.

Ketosis in pregnant women: causes, consequences, and correction

Background. Compared to 2013, in 2019 the number of pregnancies in Ukraine decreased by 32.7 %, so the value of each pregnancy and medical liability have proportionally increased. Because pregnancy is a ketogenic and diabetogenic condition, the issue of ketosis in pregnant women requires close medical attention.
 Objective. To describe the causes, consequences and correction of ketosis in pregnant women.
 Materials and methods. Analysis of literature sources on this issue.
 Results and discussion. Ketosis of pregnant women is divided into diabetic and non-diabetic. The total prevalence of ketosis is 1.7-3.6 %. Risk factors for ketosis in pregnant women include starvation, dehydration, decreased blood buffer capacity, increased production of contrainsular hormones and stress. In addition, ketosis is facilitated by the fact that placenta produces placental lactogen (in late pregnancy – up to 1 g per day) – a powerful contrainsular hormone and ketogenic agent (via stimulating lipolysis in the liver). The development of ketosis is usually provoked by infections, acute diseases, and taking certain medications (glucocorticoids, adrenoblockers). In settings of ketoacidosis, the fetus develops bradycardia, hypoxia and distress, ante- and perinatal mortality increases. If the mother has ketosis with β-oxybutyrate in blood and keto acids in the amniotic fluid, it causes behavioral and intellectual disorders in the child. The links of ketosis pathogenesis include energy starvation due to poor nutrition and/or impaired insulin production, lipase activation with the formation of ketone bodies, protein breakdown, hyperglycemia development, and oxidative stress. The majority of cases of ketosis are diagnosed at the stage of decompensation. Polyatomic alcohol xylitol is one of the main means to eliminate ketosis. Xylitol (Xylate, “Yuria-Pharm”) promotes the formation of glycerophosphate in the pentose phosphate cycle, enhances glycogen production, reduces lipolysis, increases ATP level in liver, promotes insulin production, reduces lactate. The inclusion of Xylate (6-8 ml/kg of body weight for 3 days) into the ketosis therapy can significantly accelerate the elimination of ketosis. Xylate does not increase glucose levels and has nitrogen-sparing properties.
 Conclusions. 1. Pregnancy is a ketogenic condition. 2. Ketoacidosis of pregnant women is associated with high perinatal losses. 3. Xylate has shown high antiketogenic activity and a number of additional beneficial effects.

Characteristics of Stress Drop and Energy Budget from Extended Slip-Weakening Model and Scaling Relationships

The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment Mo, S-wave velocity Vs, corner-frequency fc, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, MW 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, Gc. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to fc given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga’s dimensionless number was equivalent to the breakdown stress drop, as well as Brune’s effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to Mo = 1017~1018 Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent Vr-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate Gc with respect to breakdown distance Dc from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop,   and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.

Effect Of Phenol Addition To Transformer Oil Breakdown Voltage

The failure of transformer insulation often occurs due to various kinds of things, one of which is failure in the oil isolation caused by the condition of oil that has been dirty or has been contaminated with other particles in the transformer. Phenol is a chemical that can purify or cleanse particles or impurities that are in used transformer oil, so that it can increase the breakdown stress on used insulation oil. Phenol contains acid which can attract particles and impurities in the transformer oil which results in a decrease in the breakdown strength of the insulating oil. The results of testing of used isolation oil by adding phenol as much as 10, 15 and 20 ml showed an increase in the value of breakdown voltage with a distance of 2.5 mm ball inlet electrode. Translucent stresses that meet the SPLN standard 49-1: 1982, that is ≥ 30 kV at intervals of 2.5 mm were obtained by adding 20 ml of phenol to the volume of used 400 ml transformer oil

Retrospective Comparison of Complications with Open versus Minimally Invasive Achilles Tendon Repair

Category:Sports; OtherIntroduction/Purpose:Despite the relatively high frequency of Achilles ruptures, there is no clear consensus on the optimal treatment method. The debate has traditionally been framed by the tension between the risk for rerupture seen with nonoperative treatment and the risk for wound issues seen with operative treatment. Studies have demonstrated conflicting results when comparing complications associated with each treatment. The current study analyzed complications of patients with Achilles tendon ruptures that received either minimally invasive repair or open standard repair by a single surgeon.Methods:We conducted a retrospective chart review of patients that had Achilles tendon repair performed by the senior author between July 1st 2011 and January 22nd 2020. The senior author’s preferred operative technique transitioned from an open standard procedure to a minimally invasive procedure within this time frame, and patients were divided accordingly. Patient demographics, medical history, social history, surgical details, and additional surgeries were recorded. Patient outcomes and any complications were also recorded. Complications included any wound related issues or infection, erythema, DVT, wound breakdown, drainage, equinus contracture, and calcaneus stress reaction. Pain, swelling and/or tenderness were not considered complications. Independent sample t-tests and chi-square analyses were conducted to assess for differences in patient demographics and operative outcomes between the minimally invasive and open procedure treatment groups.Results:Of the 127 included patients, 75.6% were male with an average age of 41.85 (+-14.02). 30 (23.6%) patients had the minimally invasive approach, while 97 (76.4%) had the open approach. 82.7% were non-smokers, and the average BMI was 31.47(+-29.84). A majority of injuries (63.8%) occurred while playing sports. There were 10 complications, all of which were wound-related and all of which were in the open group (p=0.06). There were no revision surgeries in the minimally invasive group, and 10 in the open group (p=0.06). There were no recorded reruptures in either group.Conclusion:This study sought to determine the complication profile of two operative treatments for Achilles tendon ruptures, open standard and minimally invasive repair. Recent literature has suggested that minimally invasive repair results in superior outcomes to open repair. Our study found that both repeat surgery and complications trended towards a higher rate following open repair compared to minimally invasive repair, although the difference was not statistically significant (p=0.06). It is notable, however, that there were fewer total patients in the minimally invasive group and that there was not a single wound complication in the minimally invasive group.

Numerical Investigation of Injection-Induced Fracture Propagation in Brittle Rocks with Two Injection Wells by a Modified Fluid-Mechanical Coupling Model

Hydraulic fracturing is a key technical means for stimulating tight and low permeability reservoirs to improve the production, which is widely employed in the development of unconventional energy resources, including shale gas, shale oil, gas hydrate, and dry hot rock. Although significant progress has been made in the simulation of fracturing a single well using two-dimensional Particle Flow Code (PFC2D), the understanding of the multi-well hydraulic fracturing characteristics is still limited. Exploring the mechanisms of fluid-driven fracture initiation, propagation and interaction under multi-well fracturing conditions is of great theoretical significance for creating complex fracture networks in the reservoir. In this study, a series of two-well fracturing simulations by a modified fluid-mechanical coupling algorithm were conducted to systematically investigate the effects of injection sequence and well spacing on breakdown pressure, fracture propagation and stress shadow. The results show that both injection sequence and well spacing make little difference on breakdown pressure but have huge impacts on fracture propagation pressure. Especially under hydrostatic pressure conditions, simultaneous injection and small well spacing increase the pore pressure between two injection wells and reduce the effective stress of rock to achieve lower fracture propagation pressure. The injection sequence can change the propagation direction of hydraulic fractures. When the in-situ stress is hydrostatic pressure, simultaneous injection compels the fractures to deflect and tend to propagate horizontally, which promotes the formation of complex fracture networks between two injection wells. When the maximum in-situ stress is in the horizontal direction, asynchronous injection is more conducive to the parallel propagation of multiple hydraulic fractures. Nevertheless, excessively small or large well spacing reduces the number of fracture branches in fracture networks. In addition, the stress shadow effect is found to be sensitive to both injection sequence and well spacing.

Performance Insulator Cover Type : YSL-70-AP Post Voltage Break Down Test

Electrical energy affect to economic, electrical energy consumption will increase and decrease likely economics. In this globalization era, electricity consumption was increased trend yearly since industrialization era. The reliability Electrical energy is very important for economic growth. The lower SAIDI and SAIFI is the bench mark for reliability of electrical energy supply. The reliable of insulator cover type: YSL-70-AP affect to the reliability electrical distribution energy on over head distribution circuit. Insulator cover protected to over head distribution circuit againt animal, bird, tree ang other temporary disturbance. Insulator cover also to protect half insulated medium voltage cable againt partial discharge and flashover.   Over voltage stress more often during operation, to impact to the material insulation performance. This quantitative research founding:  insulator cover type: YSL-70-AP still feasible to use after voltage breakdown stress. The fault current is still under the maximum allowable leakage current (11,600 micro ampere) which is 41.61 micro ampere, and breakdown voltage is still   higher than minimum that specified (24 kilo volt), which is 49.63 kilo volt. Post breakdown voltage the material insulation performance of insulator cover type: YSL-70-AP is good, and reliable to continuous operation over head distribution circuit.