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The thickening management index for food for dysphagia is important in enabling recognition of the rheological properties of thickened liquids, including their static and dynamic properties. One of the static properties of these liquids is the yield stress. An improvement to the simplified inclined plane test is proposed here that involves use of an automatic system for measurement of the displacements of thickened liquids on an inclined plate. The aim of this study is to investigate the relationship between the displacements of the thickened liquids and the variable thickener concentrations using an optical sensor. To measure the displacement of each thickened liquid on a clear inclined plate, an optical sensor that has a 12-mm-long light receiving surface is selected to form a one-dimensional position-sensitive detector (1D-PSD) under the clear inclined plate. The relationship between the angle of inclination of the plate θ at which the maximum voltage occurred in the 1D-PSD and five thickener (xanthan gum) concentrations c, ranging from 1.0 to 3.0 wt% in steps of 0.5 wt%, was investigated. It was confirmed that an approximately linear plot was obtained under the condition that θ = 8.24 c + 0.18, with the correlation R = .99 (for n = 7). This result indicated that the optical sensor composed of the 1D-PSD can measure the displacements of thickened liquids with various thickener concentrations on the clear inclined plate automatically.

Polymers are widely used as insulation materials in the electrical industry because their existing electrical and mechanical properties can be altered by adding different types of additives. Successful prediction of the service life of the insulators used in the electrical industry is important for the reliability of the system. For this purpose, insulating materials are subjected to tests according to various standards. In this study, unlike the literature, a polymeric insulator was produced by adding 3 wt.% zinc oxide (ZnO), magnetite (Fe 3O 4), and nickel (Ni) into the polyester. The produced samples were subjected to the inclined plane test in accordance with ASTM (American Society for Testing and Materials) D-2303 standards. In order to analyze the electric and magnetic field distributions formed on the samples during the inclined plane test, first, the current flowing on the samples during the test was measured. Following this, analyses were carried out by creating a simulation model of the samples. Studies found in the literature mainly focus on two-dimensional investigation of the electrical field distribution. This study concentrates on the three-dimensional examination of the electrical field also considering the magnetic field distribution. Results of this study showed that prior numerical analysis gives insight into information about the real-life behavior of the samples.

This paper investigates the effect of the test voltage level on the performance of silicone rubber in inclined plane tracking and erosion test. Silicone rubber composites, filled with either alumina tri-hydrate or ground silica to 30 wt% or 50 wt%, are tested in inclined plane tracking and erosion test under 2.5 kV, 3.5 kV, and 4.5 kV. The degradation patterns of the tested silicone rubber surfaces are found dependent on the test voltage level during the inclined plane tracking and erosion test, as the dry-band arcing on silicone rubber tends to form tracks under relatively mild test voltages and deep erosion under the critical test voltage. These findings confirm the importance of employing the critical voltage while evaluating the erosion resistance of silicone rubber in the inclined plane tracking and erosion test. In addition, the critical test voltage of silicone rubber is found dependent on the amount of filler added to the composite., 2022 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), October 30 - November 2, 2022, Denver, Colorado, United States

This paper investigates partial discharge (PD) characteristics that lead to the erosion of silicone rubber (SR) polymer under AC stress and DC stress of both polarities. The experiments are performed on high temperature vulcanized (HTV) SR material samples. The inclined plane test apparatus, constructed in accordance with IEC 60587 requirements, is employed to produce the surface partial discharges and the resulting accelerated aging of the specimens. Two commercial instruments are used to obtain the PD data. A concurrent analysis of visual observations of discharge and PD data is performed to classify discharges based on the severity of material degradation that each type causes. Three types of PD are identified and characterized using diagrams of charge magnitude versus time and a signal processing technique called time-frequency mapping. Individual pulse waveshapes of each type of discharge are also analyzed. PD pulse waveforms are analyzed according to their amplitude, energy, pulse width, and frequency spectrum. These pulse waveform parameters are evaluated and compared for the eroding discharge pulses under AC and DC voltage stresses. It is found that the stages of material degradation during IPT are related to the variations in discharge magnitude and the location of pulse clusters on the time-frequency maps.

This paper presents the effect of different fillers on tracking length of electrical insulators. Insulator samples were prepared using polyester resin-c and were tested according to ASTM D2302. A standard test known as “Inclined plane test” is used to test the insulators after the application of high stresses. Track length of each sample is measured using a Polari scope. Track length of filler added insulators is compared to the insulator without filler and a significant change was noted among them.

The presented paper aims to highlight the role of filler-polymer interface on the DC erosion resistance of silicone rubber (SiR) outdoor insulators. SiR composites filled with nano-sized boron nitride and fumed silica have been prepared in this study. Electrical and thermal experimental tools of the inclined plane tracking-erosion test, simultaneous thermogravimetric- differential thermal analyses, and thermal conductivity measurements are used to analyze the prepared nanocomposites. The analysis primarily investigates whether the composite’s enhancement of thermal conductivity or filler interface would be more influential on erosion suppression. Literature reports that the boron nitride filler improves SiR’s thermal conductivity, whereas fumed silica provides an exceptional interaction with SiR at the filler interface. SiR was filled with boron nitride at 5wt% (percent by weight) and 10wt%, while fumed silica was loaded with 5wt% and used as a reference composite in the study. The obtained results clearly indicate a superior erosion resistance of the silica filled SiR over the boron nitride filled one. An observation which seemingly could give more significant role of the filler-polymer interface on the erosion resistance of SiR used for high voltage DC outdoor insulators., IEEE 2020 International Conference on Dielectrics, 6-31 July, Virtual Edition, Valencia, Spain

Silicone insulating rubber is an elastomer widely used in industry, especially in the manufacturing of insulators for power lines. This material ages or degrades due to pollution and environmental factors such as UV, rain, and temperature. In order to evaluate its resistance to tracking and erosion, international standards like IEC (International Electrotechnical Commission) include testing for insulating materials such as the inclined plane test (IPT) or tracking wheel test. However, the results from these tests are sometimes subjective and inconclusive. Thus, objective ways of evaluating insulating materials are needed. In this paper Fractal Analysis is used to classify the results of electrical testing in sheds proceeding of commercial high voltage insulators through the inclined plane test. The results show that Fractal Analysis constitutes a more objective way to classify the electrical strength of high voltage insulators.

It is of great interest and challenge to simultaneously improve the anti-pollution and tracking resistance of silicone rubber for its application in outdoor high voltage insulation. In this work, we proposed an efficient approach to address this issue by incorporating fluorine-containing polyphenylsilsesquioxane (F-PPSS) and ureido-containing MQ silicone resin (U-MQ) into addition-cure liquid silicone rubber (ALSR). F-PPSS/U-MQ significantly improved the tracking resistance and hydrophobicity of ALSR. By adding 2 phr F-PPSS and 1 phr U-MQ, ALSR passed the 1A 4.5 level inclined plane test with merely 0.2% eroded mass, and had a water contact angle as high as 121°. The synergism of F-PPSS and U-MQ on suppressing the ALSR degradation was further revealed and demonstrated. Our findings exhibited great potentials for fabricating silicone rubber with prominent tracking and erosion resistance by the combination of prevention and inhibition of tracking damage, endowing it with excellent long-term stable service performance.

In recent years, silicone rubber-based composites have been widely investigated for outdoor applications due to their promising insulating properties. However, mechanical, thermal, and tracking properties of pure silicone rubber are very poor, which restrains its application for long-term performance. In this research work, the influence of microsized alumina trihydrate (ATH) and micro/nanosized silica (SiO$_{2})$ fillers on mechanical, thermal, and electrical properties of room temperature vulcanized silicone rubber (RTV-SiR) has been studied. SiR-blends with varying amounts of ATH and SiO$_{2}$ particles were prepared by blending in a two-roll mixing mill, compression molding, and postcuring processes in sequence. In order to evaluate relative tracking and erosion resistance of SiR-blends, an inclined plane test (IPT) was conducted in accordance with the ASTM D2303 standard procedure. Surface temperature distribution was recorded using a Fluke-Ti25 infrared camera during IPT experiments. Thermogravimetric analysis was carried out to analyze the thermal stability of ATH and silica-filled silicone rubber samples. Tensile strength, percent elongation at break, hardness, erosion, tracking resistance, and thermal properties were also investigated and discussed. Results showed that the mechanical, thermal, tracking, and erosion performances of SiR-blends are improved by the incorporation of ATH and silica particles, which is governed by filler type, size, and wt. % in the polymer matrix.

Our previous study revealed that early application of electrical field stimulation (EFS) with the anode at the lesion and the cathode distal to the lesion reduced injury potential, inhibited secondary injury and was neuroprotective in the dorsal corticospinal tract after spinal cord injury (SCI). The objective of this study was to further evaluate the effect of EFS on protection of anterior horn motoneurons and their target musculature after SCI and its mechanism. Rats were randomized into three equal groups. The EFS group received EFS for 30 minutes immediately after injury at T10. SCI group rats were only subjected to SCI and sham group rats were only subjected to laminectomy. Luxol fast blue staining demonstrated that spinal cord tissue in the injury center was better protected; cross-sectional area and perimeter of injured tissue were significantly smaller in the EFS group than in the SCI group. Immunofluorescence and transmission electron microscopy showed that the number of spinal cord anterior horn motoneurons was greater and the number of abnormal neurons reduced in the EFS group compared with the SCI group. Wet weight and cross-sectional area of vastus lateralis muscles were smaller in the SCI group to in the sham group. However, EFS improved muscle atrophy and behavioral examination showed that EFS significantly increased the angle in the inclined plane test and Tarlov's motor grading score. The above results confirm that early EFS can effectively impede spinal cord anterior horn motoneuron loss, promote motor function recovery and reduce muscle atrophy in rats after SCI.

Polymeric insulators are widely used for HV overhead lines and substations in polluted areas because of their hydrophobicity. However, it has been seen that the shank regions are vulnerable to thermal damage from partial arcs. Textured insulators have recently been proposed in order to reduce both the leakage current density and electric field strength in such regions, and by the same means to achieve an increase in creepage length. Inclined plane testing according to IEC 60587 is an indicator for the evaluation of the resistance to tracking and erosion properties of the silicone rubber formulation. In the case of conventional plane SiR insulators, it has been seen that dry bands were readily formed at or near the ground electrode, and these were often bridged by arc-like discharges causing deep erosion. By using IR camera, we measured the thermal activity of dry bands and the associated discharge in order to estimate the dynamic of the streamer/sparks with time. The observations show that the displacement of those discharges is not uniform and depends on the insulator surface state. Correlation between the temperature variation and the discharge position will made and a comparison with leakage current evolution will be discussed. A relationship is proposed also for the calculation of both of the insulator power loss and resistance.

This paper aims to investigate the effect of nano-sized alumina tri-hydrate on the DC erosion resistance of silicone rubber, using the inclined plane tracking and erosion test. Silicone rubber composite containing nano-sized alumina tri-hydrate is comparatively analyzed with reference to silicone rubber filled with fumed silica at loading level of 5 wt%. Moreover, commercial silicone rubber composites that contain micro-sized alumina tri-hydrate at high loading levels are used for reference. Thermal characterization of silicone rubber composites is presented using simultaneous thermogravimetric and differential thermal analyses. The results obtained indicate a correlation between the erosion resistance determined using the inclined plane tracking and erosion test under DC voltages and the level of interaction between the filler and the silicone rubber tethering the siloxane chains, thereby suppressing the depolymerization and promoting crosslinking of silicone rubber. It also appears that the loading level of nano-sized alumina tri-hydrate is an essential factor that needs to be considered in order to obtain an evident erosion suppression effect for the water of hydration., 2019 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Oct. 20-23, 2019, Richland, Washington, USA

Cross-linked polyethylene (XLPE) and silicone rubber (SiR) samples were subjected to a high-voltage AC stress plane–plane configuration and inclined plane test, respectively. The voltage was applied such that discharge was observed across the surface of the XLPE test sample for several hours and for visible damage to occur on SiR samples also after several hours. Selected stressed samples together with virgin samples from the same manufactured batch were tested using nuclear magnetic resonance (NMR) spectroscopy. Specifically, 1 H NMR spin–lattice ( T 1 ) and spin–spin ( T 2 ) relaxation time measurements were employed to examine potential changes in the chemical bonding of undamaged and damaged XLPE and SiR samples. Preliminary results show that there may be a moderate increase in the T 1 and T 2 values of the damaged samples in comparison with the undamaged ones. This raises the possibility that NMR can be a useful additional experimental tool in characterising material degradation.

The performance of RTV coatings on insulator was not efficient due to degradation of their electrical and mechanical properties with age. The degree of ageing of the RTV coated insulators depends upon the severity in the pollution level of the environment and service voltage. Polymer surface of the insulator exposed to stress for long term due to pollution mechanical and electrical properties will be lost. In present study tracking and erosion test for 1000hrs as per IEC 61109 standards is performed and ageing performance of Type-A, Type-B insulators are evaluated. Inclined plane test is conducted as per IEC 60587 standards for different lengths of RTV coated Insulator to optimize and economize the performance of RTV coated insulator. It was possible to conclude that ageing test on RTV coated insulator is essential to evaluate long term performance of coatings and 1/4 length of the RTV coated insulator is sufficient to withstand the pollution severity.

Most outdoor solid insulators may suffer from surface degradations due to non-stationary currents that flow on the insulator surface. These currents may be classified as leakage, discharge and tracking currents due to their disturbing potencies respectively. The magnitude of these currents depends on the degree of the contamination of surface. The leakage signals are followed by discharge signals and tracking signals which are capable of forming carbonized tracking paths on the surface between high voltage and earth contacts (surface tracking). Surface tracking is one of the most breakdown mechanisms observed on the solid insulators, especially polymers which may cause severely reduced lifetime. In this study the degradations observed on polyester resin based insulators are investigated according to the IEC 587 Inclined Plane Test Standard. The signals are monitored and recorded during tests until surface tracking initiated. In order to prevent total breakdown of an insulator, early detection of tracking signals is vital. Continuous Wavelet Transform (CWT) is proposed for classification of signals and their energy levels observed on the surface. The application of CWT for processing and classification of the surface signals which are prone to display high frequency oscillations can facilitate real time monitoring of the system for diagnosis.

Sonchus arvensis, a perennial sowthistle, is a common but underutilized species of Kathmandu, Nepal. Several uses like sedative, antioxidant and kidney stone eradicating properties have been identified till date, but study on other pharmacological activities is not yet explored. Therefore, this plant was collected from Kathmandu; aerial parts of the plant were dried, crushed, and extracted using a Soxhlet apparatus. The methanolic extract was then concentrated for screening pharmacological effects. While comparing with the standards, the plant was found to possess strong anti-inflammatory activity and inhibitory effect in Gastro Intestinal (GI) motility and locomotor activity in a dose-dependent fashion. The plant, however, did not show skeletal muscle relaxant activity as observed in the traction test and inclined plane test. Thus, it is concluded that the plant possess strong phyto-chemicals having anti-inflammatory activity and inhibitory effect in locomotion and GI motility. Key words: Sonchus, anti-inflammatory, motility, locomotion, extraction.

Polymer materials that are used in outdoor enviroments are exposed to humidity and polution. In addition, some insulation materials installed in water or embeded to slush containing serious pollutants for a long time. These conditions adversely affect the dielectric properties of insulating materials. In this study, the prepared unsaturated polyester (UPE) samples are stored in an ionized water solution for 8, 24, and 168 hours. This ionized water solution is considered to represent the polluted water in the outdoor environments. Further, the dielectric behaviors of the prepared polyester samples are investigated using the inclined plane test (IPT) method, whereas the leakage current data that are recorded during the experiment are analyzed using the recurrence plot (RP) method. The results of applying the inclined plane test on the unsaturated polyester samples depict that the lifetime of the samples decreased with an increase in the period of storage in the ionized water solution. Further, the results of the recurrence plot analysis reveal that the recurrence plot point density also depicted a decrease with an increase in the period of storage in the ionized water solution.

The paper reviews previous work on the DC inclined plane test and suggests equivalent DC voltage levels in parallel to AC voltage in the ASTM inclined plane tracking and erosion test. The aim of this work is to provide a basis for standardizing the inclined plane test for DC voltage. Round robin tests done in five laboratories on five specimens of a silicone rubber material were done with the purpose of establishing appropriate ratios by which the equivalent DC voltages can be determined with respect to the corresponding AC voltages. These levels were determined as 67% and 87%, for +DC and –DC respectively, of the AC initial tracking voltage, and for practical purposes, these levels are rounded to 70 and 90%.

The aim of the current work was to explore the muscle relaxant effect of pistagremic acid (PA) isolated from Pistacia integerrima in various animal paradigms. In a rotarod test, PA caused a significant (p

Polymeric materials are generally made up of two types ethylene propylene dine monomer (EPDM) and silicon rubber(SR). Though composite insulators have shown good performance in hostile environments but silicon rubber have reduced contamination problem to some extent. Hydrophobic property of silicon rubber does not allow the surface to get wet and hence contamination does not occur. This paper presents some laboratory tests performed on silicon rubber insulators to ascertain the aging. Aging properties of the polymeric materials have been studied using inclined plane test. In inclined plane test pollution of different severity was coated on the surface of polymer and proper severity was determined for the ageing. Hence aging parameters which influence aging has been studied.

Background context Spinal cord trauma is a major cause of mortality and morbidity. Although no known treatment for spinal cord injury exists, a limited number of effective treatment modalities and procedures are available that improve secondary injury. Hyperbaric oxygen (HBO) treatment has been used to assist in neurologic recovery after cranial injury or ischemic stroke. Purpose To report the findings on the effectiveness of HBO treatment on rats with experimental traumatic spinal cord injury. Improvement was evaluated through motor strength assessment and nitrite level assay testing. Study design We randomly distributed 40 rats among 5 groups of 8 rats each: sham incurable trauma, induced trauma, HBO treatment begun at the 1st hour, HBO treatment begun at the 6th hour, and HBO treatment begun at the 24th hour. Method The HBO treatment was administered to rats in three of the groups and conducted in two 90-minute sessions, under an absolute atmospheric pressure of 2.4 at 100% oxygen for 5 days. In the motor strength evaluations, all the rats were observed during the inclined plane test and clinical motor examination on the first, third, and fifth days. In addition, the nitrite levels of spinal cord tissues on the sixth day were also studied. Results Results from the inclined plane levels and motor strength test from all the three groups undergoing HBO treatment were higher than those from Group 2. It was also determined that early HBO treatment resulted in higher recovery rates (groups 3 and 4). The highest levels were seen in the group in which the HBO treatments were started in the first hour (Group 3). It was noted that nitrite levels of rats in the group exposed to trauma increased, compared with the sham group, but increased levels also diminished after HBO treatments. Again, the greatest decrease in nitrite levels was evident in the group where the HBO treatment was started the earliest (Group 3). Conclusions Prompt HBO treatment after trauma significantly contributed to the clinical, histopathologic, and biochemical recovery of the rats.

We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P

This study presents an animal mobility system, equipped with a positioning running wheel (PRW), as a way to quantify the efficacy of an exercise activity for reducing the severity of the effects of the stroke in rats. This system provides more effective animal exercise training than commercially available systems such as treadmills and motorized running wheels (MRWs). In contrast to an MRW that can only achieve speeds below 20 m/min, rats are permitted to run at a stable speed of 30 m/min on a more spacious and high-density rubber running track supported by a 15 cm wide acrylic wheel with a diameter of 55 cm in this work. Using a predefined adaptive acceleration curve, the system not only reduces the operator error but also trains the rats to run persistently until a specified intensity is reached. As a way to evaluate the exercise effectiveness, real-time position of a rat is detected by four pairs of infrared sensors deployed on the running wheel. Once an adaptive acceleration curve is initiated using a microcontroller, the data obtained by the infrared sensors are automatically recorded and analyzed in a computer. For comparison purposes, 3 week training is conducted on rats using a treadmill, an MRW and a PRW. After surgically inducing middle cerebral artery occlusion (MCAo), modified neurological severity scores (mNSS) and an inclined plane test were conducted to assess the neurological damages to the rats. PRW is experimentally validated as the most effective among such animal mobility systems. Furthermore, an exercise effectiveness measure, based on rat position analysis, showed that there is a high negative correlation between the effective exercise and the infarct volume, and can be employed to quantify a rat training in any type of brain damage reduction experiments.

Objective To investigate the healing effects of erythropoietin (EPO) and stem cells (SCs) in traumatic brain injury (TBI). Methods Twenty-nine Wistar albino rats were used and separated into the following groups: control (C), EPO, SC, and SC+EPO. Group C received a TBI only, with no treatment. In the EPO group, 1000 U/kg EPO was given intraperitoneally at 30 minutes after TBI. In SC group, immediately after formation of TBI, 3 × 10,000 CD34 + stem cells were injected into the affected area. In the SC+EPO group, half an hour after TBI and the injection of stem cells, 1000 U/kg EPO was injected. Before and after injury, trauma coordination performance was measured by the rotarod and inclined plane tests. Results Seven weeks after trauma, rat brains were examined by radiology and histology. Rotarod performance test did not change remarkably, even after the injury. Compared with group C, the SC+EPO group was found to have significant differences in the inclined plane test results. Conclusions Separately given, SCs and EPO have a positive effect on TBI, and our findings suggest that their coadministration is even more powerful. © 2016 Elsevier Inc. All rights reserved.

During the current research and development activities at Tata Steel Teesside Technology Centre, UK, the inclined plane test (IPT) is adopted as a quick method to measure the viscosity/fluidity of mould powders being used currently for continuous casting of different steel qualities and section sizes. The usefulness of the IPT method was also validated by comparing the viscosities that were measured by a high temperature viscometer. It has been established that the IPT measured viscosity values are comparable with the mould powder supplier’s data. The IPT ribbon lengths of different powders have been correlated with the viscosities using an Arrhenius type relationship. The ribbon lengths of the solidified fluxes were found to have a good correlation with the molar ratios of the corresponding powders. Hence, the relationship was further tuned to develop a viscosity prediction model using the chemical compositions of the mould fluxes (i.e. the model can be used for a quick assessment of mould flux viscosity...

The paper gives a comparison of the tracking and erosion properties and the hydrophobicity behaviour between different kind of silicone rubbers: Unfilled gum, HCR silicone rubber filled with silica, silicone rubber containing silica and ATH and liquid silicone rubber containing silica filler only. The Inclined Plane Test was used to determine the tracking and erosion performance. It is shown on an example that the principle set-up of the Inclined Plane Test can be used to evaluate the hydrophobicity as well. It is found that the performance of gum in the Inclined Plane Test is very poor. The addition of silica with filler loadings around 20 - 25 wt% improves this behavior, but failures still occur at 6 kV in the Inclined Plane Test. Commercially available liquid silicone rubber shows a better performance than high consistency rubber, in the case that both systems contain only silica fillers of similar loadings. By the additional addition of high volumes of surface modified ATH, the Inclined Plane Test can be passed reliably at 6 kV. Special focus is put in the proper statistical evaluation of the results from Inclined Plane testing. In order to obtain statistically significant data for a precise comparison of the results, the sample size for the Inclined Plane Test should be at least 20 specimens. It was further found that the type and size of ATH particles have a substantial influence on the results. It was shown that a voltage of 6 kV in the Inclined Plane Test is better suitable for the identification of weak compositions of silicone rubber than a voltage of 4.5 kV. In order for high filler loadings not to be detrimental to the hydrophobicity, the use of surface modified particles is critically important.

Aging, under contaminated conditions, manifests itself by tracking and/or erosion of polymer materials and insulators and usually leads to failure of insulators. Aging is still one of the main causes of the registered failures of polymer insulators in the field. Consequently, to improve both materials and insulator designs, it is important to understand the mechanisms of aging, as well as the factors surrounding aging, and the best way to do this is through actual field experience. However, the problem with field experience is that it often requires a very long time before any noticeable changes become evident. For this reason, several laboratory accelerated tests have been developed to evaluate aging of polymer materials and insulators.

Spinal cord injury (SCI) leads to loss of function below the lesion and affects individuals worldwide. An increasing number of experimental studies support the effectiveness of melatonin (MT) for SCI. Our objectives were to investigate neurological recovery and anti-oxidant effects of MT in animal models of SCI, and to explore the appropriate dose. Published MT studies in SCI animal models described in six databases were searched. Two practiced investigators selected the studies, extracted the data, and independently evaluated the quality of the included studies. A meta-analysis evaluated the effect of MT in SCI and a network meta-analysis was performed to explore the appropriate MT dose for SCI models. Thirteen studies were analyzed, of which three were high quality. The results of the meta-analysis manifested that the behavioral evaluation (Basso, Beattie, and Bresnahan scales, n = 90, p = 0.003; motor function scores, n = 92, p = 0.004; Tarlov's criteria, n = 150, p = 0.002; inclined plane test, n = 150, p = 0.001) and biochemical outcomes (malondialdehyde, n = 121, p = 0.0010; glutathione levels, n = 64, p < 0.0001; and myeloperoxidase activity, n = 32, p < 0.00001) were improved, compared with the control group, after MT administration. A dose of 12.5 mg/kg was most effective in SCI rat models. Studies indicated that MT administration significantly improved neurological recuperation and anti-oxidant effects in rat models of SCI. The appropriate dose of MT was 12.5 mg/kg for SCI rat models. The majority of included studies were low quality; however, optimal MT treatment in SCI still requires high quality studies.

Evaluating the electrical tracking and erosion resistance of polymeric housing materials is an essential task performed in the development of outdoor insulators. “Tracking” means the formation of a surface carbonaceous path, and “erosion” means weight loss of the housing material. An absolute measurement of the tracking and erosion resistance is not possible; only relative ranking of composites can be achieved using the standard tracking and erosion tests. During the early use of organic insulating materials, failure due to tracking was a major concern, and therefore standard screening methods were proposed to evaluate the tracking rather than the erosion resistance. Erosion has become more important following the development of tracking resistant composites containing high levels of inorganic fillers.

The synthesis and evaluation of muscle relaxant activity of series of dimeric camphor derivatives are described. Compounds in which the quaternary nitrogen atoms are separated by aromatic chain exhibited the highest efficiency as muscle relaxant. It was shown the screening of a charged atom and counter-ion does not have a significant role on the activity of the studied agents.

Objectives: Experimentally evaluate the effect of hypovolemia in acute traumatic spinal cord injury. Methods: Twenty adult male Wistar rats were submitted to traumatic spinal cord injury through spinal cord contusion by direct impact. Ten animals were subjected to bleeding of 20% of their estimated blood to simulate a hypovolemic condition after spinal cord contusion and 10 animals were used as control. The animals were evaluated before, 1, 3, 7 and 14 days after the production of the spinal cord injury through behavioral tests (inclined plane test and motor assessment). Results: The spinal cord contusion associated with hypovolemia had a negative influence on functional outcomes of the spinal cord injury. The animals submitted to hypovolemia after spinal cord contusion had lower scores in behavioral tests (inclined plane test and motor assessment), presenting a slower recovery of the motor function. Conclusion: In the experimental model used, the group of animals with hypovolemia after traumatic spinal cord injury had slower recovery and lower intensity in behavioral tests.

Radiotherapy-induced xerostomia (RIX) is the most common permanent side effect of radiotherapy (RT) to the head and neck (H&N). There is no effective topical treatment. LMS-611 is a mimetic of a natural lamellar body which prevents thick secretions like saliva from congesting organs. The primary objective of this study was to assess saliva properties before and during RT to the H&N. The secondary objectives were to re-assess saliva properties with the addition of LMS-611, measure inter-patient variability, correlate patient-reported symptoms with laboratory measurements and design subsequent first-in-human clinical trial of LMS-611. Patients with H&N cancer receiving RT as primary treatment were recruited. Patients completed the Groningen RIX (GRIX) questionnaire and provided saliva samples at baseline and weeks 2, 4 and 6 of RT. Saliva adhesiveness and viscosity were tested by measuring time taken to travel 5 cm down an inclined plane. Thirty patients were enrolled. The inclined plane test (IPT) results (s) were as follows: baseline 31.3, week 2 49.7, week 4 51.1 and week 6 55.7. Wide inter-patient variability was seen at baseline. GRIX scores increased as RT progressed. Spearman rank correlation coefficient of inclined plane tests with GRIX scores was −0.06 at baseline, 0.25 at week 2, 0.12 at week 4 and 0.08 at week 6. LMS-611 concentrations of 10 and 20 mg/ml significantly reduced IPT times on saliva samples. Saliva becomes more visco-adhesive and RIX worsens as RT progresses. There is little correlation between objective and subjective measures of RIX. The addition of LMS-611 to thick, sticky saliva restores its fluidity ex vivo. This warrants in vivo analysis of the effect of LMS-611 upon RIX.

An ISO/ASTM standard test has been used for over 20 years for detecting the presence of lubricating films on plastics (usually in web form). The test uses a wire paperclip (on end) as the rider on an inclined plane. A need for a test to measure breakaway friction of rolling element bearings for instrument pivots prompted a study to determine if the “paperclip” test could be adapted to screen bearings for low rolling friction. This paper describes the test modification and the results obtained in intralaboratory tests aimed at making the test an ASTM standard. The test was modified by replacing the paperclip rider with a rolling element bearing with the inner race fixed to an axle on a balanced rider. The inclined plane is raised to imitate rolling of the outer race on the inclined plane. The tangent of this angle is used as the test metric. Seven random ball bearings, some new, some used, were tested by six laboratories in the USA to determine if the test is repeatable enough to be an ASTM standard. The coefficient of variation was quite good within lab, and reasonable between labs. The test seems to be a fast, simple friction test for rolling element and other bearings that should be standardized.

This paper reports the results of material tracking and erosion tests, and flashover tests of full-scale insulators made from epoxy compounds. Six different formulations, all based on the cycloaliphatic epoxy family, were evaluated as flat slabs and complete insulators rated for 25 kV (line to line) system voltage. In addition, line insulators in the range 11-66 kV, that had been operating satisfactorily for several years in light to heavy contaminated regions in different countries, were evaluated to obtain information on their future expected performance. Material tracking and erosion tests were performed using the standard ASTM D-2303 inclined plane test, and a variation of the same test that was developed in-house. Flashover tests were performed using the IEC Standard 507 "clean-fog" method. Results demonstrate that all material formulations evaluated had adequate tracking and erosion resistance for outdoor use. In addition, the insulators evaluated did not flashover at nominal service voltage (and higher) under a wide range of simulated contamination conditions. The overall good performance of the insulators has been related to material formulation, design and manufacturing of the insulators.

This chapter deals with various aspects of standards and tests for composite insulators. The first part lists important IEC standards according to which composite insulators are tested and designed. Since composite insulator strings share functionally-wise many similarities with conventional—especially long rod—insulators, the relevant standards are also listed here for comparative purposes. The second part deals with some testing principles. By using the example of the Inclined Plane Test (IEC 60587), which was initially introduced in 1977 as a material test method for evaluating erosion and tracking resistance, it is possible to show that other properties of polymeric insulating materials can be evaluated using this test principle. The third part discusses analytical methods that can be used to identify the polymeric materials used in a composite insulator. This topic, known as “finger-printing”, is also part of the work currently being undertaken by the corresponding CIGRE Working Group.

In this paper the leakage current signature in the DC inclined plane test is examined for statistical indicators of the incipient erosion of silicone rubber. The mean, skewness and kurtosis are examined as useful indicators of the dry-band arcing current causing erosion. The moving window method is employed during the test to obtain an enhanced resolution in time. Simultaneous thermogravimetric-differential scanning calorimetry analysis is used to predetermine the temperature at which erosion begins, and temperature measurements taken during the inclined plane test are correlated to the leakage current leading to erosion. During erosion, more stable discharges as well as a recognizable change in the statistical distribution of the dry-band arcing current is recognizable through the analysis employed.

In this paper erosion of silicone rubber loaded with 30 wt% ATH and silica is investigated in the DC inclined plane tracking/erosion test as per ASTM D 2303. Reduced equivalent DC voltages have been applied in order to compare with the erosion under AC. Hot spot temperatures are used for comparative analysis of dry-band arcing severity on the tested materials. Also, depending on the type of filler, initiation of stable and intense dry-band arcing is discussed. Based on the results it is proposed that the existing material formulation used for AC insulators are not suitable for DC insulators as the erosion is more severe and different.

Spinal cord injury is an extremely severe condition with no available effective therapies. We examined the effect of melatonin on traumatic compression of the spinal cord. Sixty male adult Wistar rats were divided into three groups: sham-operated animals and animals with 35 and 50% spinal cord compression with a polycarbonate rod spacer. Each group was divided into two subgroups, each receiving an injection of vehicle or melatonin (2.5 mg/kg, intraperitoneal) 5 min prior to and 1, 2, 3, and 4 h after injury. Functional recovery was monitored weekly by the open-field test, the Basso, Beattie and Bresnahan locomotor scale and the inclined plane test. Histological changes of the spinal cord were examined 35 days after injury. Motor scores were progressively lower as spacer size increased according to the motor scale and inclined plane test evaluation at all times of assessment. The results of the two tests were correlated. The open-field test presented similar results with a less pronounced difference between the 35 and 50% compression groups. The injured groups presented functional recovery that was more evident in the first and second weeks. Animals receiving melatonin treatment presented more pronounced functional recovery than vehicle-treated animals as measured by the motor scale or inclined plane. NADPH-d histochemistry revealed integrity of the spinal cord thoracic segment in sham-operated animals and confirmed the severity of the lesion after spinal cord narrowing. The results obtained after experimental compression of the spinal cord support the hypothesis that melatonin may be considered for use in clinical practice because of its protective effect on the secondary wave of neuronal death following the primary wave after spinal cord injury.

International audience; Composite lining systems comprising different geosynthetics and soil are typical capping devices in modern landfills. Analyses of the behavior of capping devices have shown that they are very sensitive components thanks in part to the shear strength of geosynthetic interfaces, many of which were reported to have controlled slippage between capping lining components during landfill slope failures. There are some laboratory testing alternatives for measuring the shear strength of the interface between geosynthetics or between geosynthetics and soil. The inclined plane test is especially appropriate for shear strength tests under low normal pressure which is a specific condition of these geosynthetic systems on cap cover. However, the selected shear strengths, inferred from the laboratory experimentation, show considerable variability, which depends on the test procedure. This work proposes a new procedure and a new interpretation of the inclined plane test taking as an example the interface between geospacers and geomembranes often considered as a critical interface. The measurement of displacement acceleration during the test gives the possibility of more accurately defining the large sliding displacement shear strength, which may approach the true residual condition.

For many years glass and porcelain have been the dominant insulation materials for our bushes, insulators and circuit breakers. Recently however, the situation has changed and we now see outdoor circuit breakers at very high voltages of the order of hundreds of kilovolts using polymeric insulation. The advantages of polymeric insulation have always been known but their tracking performance in highly polluted environments has been disappointing, until now. As manufacturers engage in fierce competition to produce the new generation of insulators, the question of quality and reliability in performance becomes an overriding one. There several tests that have been prescribed by standardization bodies to assess the quality of insulation among them the IEC Tracking Test, the Inclined Plane Test [5] and the Dust Fog Test. In this the authors will start with a brief description of the chemical structures of polymeric materials. They will then discuss the Inclined Plane test based on the American Standard D2303. Further, it will describe the design and operating performance and future prospects of a test set that is suitable for rapid and reliable testing of insulator samples that may be of interest to a manufacturer.

This paper reports possible applications of microvaristor filled silicone rubber at composite insulators. Different insulator variations fitted with microvaristor filled sheds or shanks have been investigated. The insulators are dimensioned for U m = 170 kV and U m = 420 kV. Different variations of the 420 kV type were tested for their a.c. behaviour under artificial rain. In these tests the insulators with microvaristor filled silicone rubber components showed interesting properties. The suitability of microvaristor filled silicone rubber for application both in the sheds and in the sheath are discussed based on these positive results. The applicability for outdoor applications is investigated by an “inclined plane test” (material test) as well as by a “weather ageing test” under salt fog (material and design test).

Adolescent rats have been observed to be less sensitive than adults to a number of ethanol effects that may serve as feedback cues to reduce further ethanol intake. Among these findings are a few reports of attenuated sensitivities of adolescents to ethanol-induced motor impairment. The purpose of the present study was to further explore potential age-related differences in ethanol-induced motor impairment in both male and female adolescent (postnatal day [P]28-32), and adult (P68-72) Sprague-Dawley rats using an inclined plane assessment of the negative geotaxis reflex. Adult males displayed significant motor impairment at 1.5 g/kg, whereas adolescent males required higher doses, showing significant motor impairment only at doses of 2.25 g/kg ethanol or greater. Intoxicated practice did not significantly influence level of motor impairment at either age. When female rats of both ages were separately analyzed in terms of their response to ethanol, a dose of 1.5 g/kg ethanol was found to significantly impair adults, whereas adolescent females showed significant motor impairment when challenged with 2.25 g/kg but not 1.5 g/kg ethanol. Yet when the 1.5 g/kg data of females at the two ages were directly compared, no significant age difference was seen at this dose. These data document an attenuated sensitivity of adolescent relative to adult rats to the motor impairing effects of ethanol using a stationary inclined plane test, an effect particularly robust in male animals, and demonstrates the utility of this test for assessment of motor coordination in adolescent and adult rats.

The paper introduces a Weibull probabilistic model for predicting the performance of outdoor medium voltage apparatus using cycloaliphatic epoxies. Rectangular slabs of the material were tested on the inclined plane test (ASTM D2303)for determining the tracking and erosion resistance. Some slabs were sand-blasted to duplicate the degradation observed on field-aged samples that were located in various test sites for up to 20 years. Leakage current data was recorded for new and sandblasted samples during the test. The model is a product of leakage current and arc time at a particular spot as a parameter for the Weibull distribution. The model predictions are in good agreement with the experimental results.

International audience; The inclined plane test (IPT) is commonly performed to measure the interface shear strength between different materials as those used in cover systems of landfills. The test, when interpreted according to European test Standards provides the static interface friction angle, usually assumed for 50 mm displacement and denoted as View the MathML source. However, if interpreted considering the several phases of the sliding process, the test is capable of yielding more realistic information about the interface shear strength such as differentiating interfaces which exhibit the same value of View the MathML source but different behavior for displacement less than 50 mm. In this paper, the IPT is used to evaluate the interface shear strength of some materials usually present in cover liner systems of landfill. The results of the tests were analyzed for both, the static and the dynamic phases of the sliding and were interpreted based on the static initial friction angle, phi0, and the limit friction angle, philim. It is shown that depending on the sliding behavior of the interfaces, View the MathML source, which is usually adopted as the designing parameter in stability analysis, can be larger than phi0 and philim.

The inclined plane test for tracking and erosion resistance of materials, IEC-60587, has become a routine tool for researchers developing high voltage outdoor insulation materials. The test is designed for ac applications and many laboratories have many years of experience with the technique. DC power systems are becoming more important and competitive in the market place. Often insulation systems designed for AC applications are utilised on dc systems. However, there is clear evidence of behavioural differences between identical materials under AC and DC stresses. An equivalent test to IEC-60587, has been developed and utilised for the dc case. A computer-based monitoring system is used to study materials beyond the criteria set by IEC 60587 and this system is reviewed in the paper. A number of different formulations of silicone rubber have been evaluated using the rig described. In this paper particular attention is given to the nature of electrical discharges under different test conditions and how this influences material degradation. Measurements show that the sample degradation mechanism is very different for positive and negative HVDC, while positive DC has shown to be the most aggressive for the materials tested.

A novel laser technique is used to study the degradation of silicone rubber composites, along with inclined plane test for 18 different composites, using ATH and silica as fillers, with various concentrations and mean particle sizes. The results from the constant temperature approach are compared with the results from inclined plane test by means of a statistical correlation tool. The two empirical relationships observed in the experiments have shown that it is possible not only to detect erosion on a silicone rubber surface by knowing the third harmonic component of the discharge energy, but also quantify such damages.

This paper reports on a study of the influence of the level of alumina trihydrate (ATH) on the electrical insulation properties and the tracking and erosion resistance of high temperature vulcanized silicone rubber (HTV-SIR). The electrical resistance of silicone rubber was measured using a high resistance meter. It decreased with increasing temperature and decreased greatly more than 373 K (273 C). Also it decreased greatly with increasing level of ATH. The tracking and erosion resistances of HTV-SIR with various ATH level were evaluated by employing IEC 587 inclined plane test. It was observed that the tracking and erosion resistance improved greatly more than 130 phr as increasing level of ATH. It was found that the dielectric breakdown voltage of silicone rubber decreased a little with increasing level of ATH.

Ageing due to multifactor stresses of the surface of organic materials has to be divided into two different stages named "early" and "late" stage of ageing. While standardized tests such as the inclined plane test or the rotating wheel dip test aim at verifying only the performance of insulating materials in the late stage of ageing, growing interest of scientists recently focuses on the early stage of ageing, characterized by a loss of hydrophobicity and an increase of leakage current as well as the appearance of surface partial discharges. To assess the phenomena in the early stage of ageing several new test facilities and diagnostic tools have been developed and applied, such as the "inverse" climatic chamber generating continuous condensation, the cold fog chamber and the "modified" rotating wheel dip test arrangement. This paper presents some new test results of polymer resin materials achieved in above mentioned test facilities and enables a comparison and assessment of the efficiency and the advantages of relevant test procedures.