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Due to recent advances, the numerical analysis of submarine three-core armored cables can nowadays be developed through the finite element method (FEM) in a small slice of the cable. This strongly reduces the computational burden and simulation time. However, the performance of this ultra-shortened 3D-FEM model is still to be fully assessed with experimental measurements. This paper focuses on this validation for an extensive variety of situations through the experimental measurements available in the specialized literature for up to 10 actual cables. In particular, it deals not only with relevant calculations at power frequency, like the series resistance and inductive reactance or the induced sheath current, but also with other aspects never analyzed before through 3D-FEM simulations, such as the zero sequence impedance, the magnetic field distribution around the power cable, as well as side effects due to the nonlinear properties of the armor wires. All this considering different armoring and sheath bonding configurations. Results show a very good agreement between measured and computed values, presenting the ultra-shortened 3D-FEM model as a suitable tool for the analysis and design of three-core armored cables, and opening the possibility to reduce the need of extensive experimental tests in the design stage of new cables.

In April and May 2021, Uppsala University Campus Gotland performed an archaeological investigation at Västergarn, 25 kilometres southwest of Visby, as part of an advanced field course in archaeology. Two trenches were investigated, covering an area of 90 m2. The purpose was to reinvestigate post-holes, remains of a wooden floor and a water hole unearthed in 2013. Further to understand how these remains relate to a number of Late Viking Age artefacts discovered in the same area. As a result it could be established that the wooden floor belongs to a medieval house foundation with corner-hearth and a partly preserved stone-lined sill. The foundation is mainly dated by shards of Baltic ware to the period 1100/1125-1230. Find concentrations of iron tools adjacent to the hearth, iron armory plates and glass beads may indicate a small workshop. The Viking Age artefacts relate to a separate post-hole building probably dated to the 11th century. The date and the function of the water hole remain inconclusive. The large amount of animal bones deposited in the stone paved water hole, among them a high proportion of horse bones indicates a function as a well for grazing cattle in the area during the dry season. A coin-like copper pendant with pseudo-Islamic glyphs found adjacent to the water hole underlines Viking Age activity in the area. The results show that the house remains in the area investigated probably belong to the outer precinct of the harbour settlement in Västergarn. This particular area within the Västergarn rampart was settled presumably between AD 1000/1050-1200/1230. Findings such as cultural layers, strengthens indications of a complex and active settlement in the late Viking and early medieval period., Snauvalds 1:2, Västergarn socken, Gotlands kommun, GotlandRAÄ nr: L1976:7960 (tidigare RAÄ-nr Västergarn 50:1)

The great expansion in offshore power plants is raising the concern regarding the cumulative effect of the electromagnetic field emissions caused by submarine power cables. In this sense, owners are required to predict these emissions during the permitting and consenting process of new power plants. This is a challenging task, especially in the case of HVAC three-core armored cables due to their complex geometry. Customarily, 2D approaches based on the finite element method (FEM) have been employed for evaluating the magnetic field emissions caused by these cables. However, inaccurate results are obtained since the phase conductors and armor twisting is omitted. This work develops, for the first time in the literature, an in-depth analysis of the magnetic field caused by this type of cable through an ultra-shortened 3D-FEM model, which is also faced to experimental measurements taken on an actual 132 kV, 800 mm2 three-core armored cable. Relevant conclusions are derived regarding the impact of the cable design on the magnetic field emissions, including material properties, as well as single and double-layer armors, presenting the proposed model not only as a valuable tool for predicting purposes, but also for optimizing cable design in terms of magnetic field emissions.

Due to recent advances, the numerical analysis of submarine three-core armored cables can nowadays be developed through the finite element method (FEM) in a small slice of the cable. This strongly reduces the computational burden and simulation time. However, the performance of this ultra-shortened 3D-FEM model is still to be fully assessed with experimental measurements. This paper focuses on this validation for an extensive variety of situations through the experimental measurements available in the specialized literature for up to 10 actual cables. In particular, it deals not only with relevant calculations at power frequency, like the series resistance and inductive reactance or the induced sheath current, but also with other aspects never analyzed before through 3D-FEM simulations, such as the zero sequence impedance, the magnetic field distribution around the power cable, as well as side effects due to the nonlinear properties of the armor wires. All this considering different armoring and sheath bonding configurations. Results show a very good agreement between measured and computed values, presenting the ultra-shortened 3D-FEM model as a suitable tool for the analysis and design of three-core armored cables, and opening the possibility to reduce the need of extensive experimental tests in the design stage of new cables.

In April and May 2021, Uppsala University Campus Gotland performed an archaeological investigation at Västergarn, 25 kilometres southwest of Visby, as part of an advanced field course in archaeology. Two trenches were investigated, covering an area of 90 m2. The purpose was to reinvestigate post-holes, remains of a wooden floor and a water hole unearthed in 2013. Further to understand how these remains relate to a number of Late Viking Age artefacts discovered in the same area. As a result it could be established that the wooden floor belongs to a medieval house foundation with corner-hearth and a partly preserved stone-lined sill. The foundation is mainly dated by shards of Baltic ware to the period 1100/1125-1230. Find concentrations of iron tools adjacent to the hearth, iron armory plates and glass beads may indicate a small workshop. The Viking Age artefacts relate to a separate post-hole building probably dated to the 11th century. The date and the function of the water hole remain inconclusive. The large amount of animal bones deposited in the stone paved water hole, among them a high proportion of horse bones indicates a function as a well for grazing cattle in the area during the dry season. A coin-like copper pendant with pseudo-Islamic glyphs found adjacent to the water hole underlines Viking Age activity in the area. The results show that the house remains in the area investigated probably belong to the outer precinct of the harbour settlement in Västergarn. This particular area within the Västergarn rampart was settled presumably between AD 1000/1050-1200/1230. Findings such as cultural layers, strengthens indications of a complex and active settlement in the late Viking and early medieval period., Snauvalds 1:2, Västergarn socken, Gotlands kommun, GotlandRAÄ nr: L1976:7960 (tidigare RAÄ-nr Västergarn 50:1)

In April and May 2021, Uppsala University Campus Gotland performed an archaeological investigation at Västergarn, 25 kilometres southwest of Visby, as part of an advanced field course in archaeology. Two trenches were investigated, covering an area of 90 m2. The purpose was to reinvestigate post-holes, remains of a wooden floor and a water hole unearthed in 2013. Further to understand how these remains relate to a number of Late Viking Age artefacts discovered in the same area. As a result it could be established that the wooden floor belongs to a medieval house foundation with corner-hearth and a partly preserved stone-lined sill. The foundation is mainly dated by shards of Baltic ware to the period 1100/1125-1230. Find concentrations of iron tools adjacent to the hearth, iron armory plates and glass beads may indicate a small workshop. The Viking Age artefacts relate to a separate post-hole building probably dated to the 11th century. The date and the function of the water hole remain inconclusive. The large amount of animal bones deposited in the stone paved water hole, among them a high proportion of horse bones indicates a function as a well for grazing cattle in the area during the dry season. A coin-like copper pendant with pseudo-Islamic glyphs found adjacent to the water hole underlines Viking Age activity in the area. The results show that the house remains in the area investigated probably belong to the outer precinct of the harbour settlement in Västergarn. This particular area within the Västergarn rampart was settled presumably between AD 1000/1050-1200/1230. Findings such as cultural layers, strengthens indications of a complex and active settlement in the late Viking and early medieval period., Snauvalds 1:2, Västergarn socken, Gotlands kommun, GotlandRAÄ nr: L1976:7960 (tidigare RAÄ-nr Västergarn 50:1)

Due to recent advances, the numerical analysis of submarine three-core armored cables can nowadays be developed through the finite element method (FEM) in a small slice of the cable. This strongly reduces the computational burden and simulation time. However, the performance of this ultra-shortened 3D-FEM model is still to be fully assessed with experimental measurements. This paper focuses on this validation for an extensive variety of situations through the experimental measurements available in the specialized literature for up to 10 actual cables. In particular, it deals not only with relevant calculations at power frequency, like the series resistance and inductive reactance or the induced sheath current, but also with other aspects never analyzed before through 3D-FEM simulations, such as the zero sequence impedance, the magnetic field distribution around the power cable, as well as side effects due to the nonlinear properties of the armor wires. All this considering different armoring and sheath bonding configurations. Results show a very good agreement between measured and computed values, presenting the ultra-shortened 3D-FEM model as a suitable tool for the analysis and design of three-core armored cables, and opening the possibility to reduce the need of extensive experimental tests in the design stage of new cables.

In April and May 2021, Uppsala University Campus Gotland performed an archaeological investigation at Västergarn, 25 kilometres southwest of Visby, as part of an advanced field course in archaeology. Two trenches were investigated, covering an area of 90 m2. The purpose was to reinvestigate post-holes, remains of a wooden floor and a water hole unearthed in 2013. Further to understand how these remains relate to a number of Late Viking Age artefacts discovered in the same area. As a result it could be established that the wooden floor belongs to a medieval house foundation with corner-hearth and a partly preserved stone-lined sill. The foundation is mainly dated by shards of Baltic ware to the period 1100/1125-1230. Find concentrations of iron tools adjacent to the hearth, iron armory plates and glass beads may indicate a small workshop. The Viking Age artefacts relate to a separate post-hole building probably dated to the 11th century. The date and the function of the water hole remain inconclusive. The large amount of animal bones deposited in the stone paved water hole, among them a high proportion of horse bones indicates a function as a well for grazing cattle in the area during the dry season. A coin-like copper pendant with pseudo-Islamic glyphs found adjacent to the water hole underlines Viking Age activity in the area. The results show that the house remains in the area investigated probably belong to the outer precinct of the harbour settlement in Västergarn. This particular area within the Västergarn rampart was settled presumably between AD 1000/1050-1200/1230. Findings such as cultural layers, strengthens indications of a complex and active settlement in the late Viking and early medieval period., Snauvalds 1:2, Västergarn socken, Gotlands kommun, GotlandRAÄ nr: L1976:7960 (tidigare RAÄ-nr Västergarn 50:1)

Recently, large offshore wind power plants have been installed far from the shore, using long HVAC three-core armored cables to export power. Its high capacitance may contribute to the appearance of unwanted phenomena, such as overvoltages or resonances at low frequencies. To adequately assess these problems, detailed and reliable cable models are required to develop time-domain/frequency-domain analyses on this type of cables. This paper presents, for the first time in the literature, an assessment on the performance of 3D finite element method-based (3D-FEM) models for developing frequency-domain analyses on three-core armored cables, confronting simulation results with experimental measurements found in the literature for three real cables. To this aim, a simplified ultra-shortened 3D-FEM model is proposed to reduce the simulation time during frequency sweeps, through which relevant aspects never analyzed before with frequency-domain 3D-FEM simulations are addressed, such as total losses, induced sheath current, magnetic field around the power cable, positive and zero sequence harmonic impedances, as well as resonant frequencies. Also, a time-domain example derived from the frequency-domain analysis is provided. Remarkable results are obtained when comparing computed values and measurements, presenting the simplified ultra-shortened 3DFEM model as a valuable tool for the frequency-domain analysis of these cables.

The great expansion in offshore power plants is raising the concern regarding the cumulative effect of the electromagnetic field emissions caused by submarine power cables. In this sense, owners are required to predict these emissions during the permitting and consenting process of new power plants. This is a challenging task, especially in the case of HVAC three-core armored cables due to their complex geometry. Customarily, 2D approaches based on the finite element method (FEM) have been employed for evaluating the magnetic field emissions caused by these cables. However, inaccurate results are obtained since the phase conductors and armor twisting is omitted. This work develops, for the first time in the literature, an in-depth analysis of the magnetic field caused by this type of cable through an ultra-shortened 3D-FEM model, which is also faced to experimental measurements taken on an actual 132 kV, 800 mm2 three-core armored cable. Relevant conclusions are derived regarding the impact of the cable design on the magnetic field emissions, including material properties, as well as single and double-layer armors, presenting the proposed model not only as a valuable tool for predicting purposes, but also for optimizing cable design in terms of magnetic field emissions.

Recently, large offshore wind power plants have been installed far from the shore, using long HVAC three-core armored cables to export power. Its high capacitance may contribute to the appearance of unwanted phenomena, such as overvoltages or resonances at low frequencies. To adequately assess these problems, detailed and reliable cable models are required to develop time-domain/frequency-domain analyses on this type of cables. This paper presents, for the first time in the literature, an assessment on the performance of 3D finite element method-based (3D-FEM) models for developing frequency-domain analyses on three-core armored cables, confronting simulation results with experimental measurements found in the literature for three real cables. To this aim, a simplified ultra-shortened 3D-FEM model is proposed to reduce the simulation time during frequency sweeps, through which relevant aspects never analyzed before with frequency-domain 3D-FEM simulations are addressed, such as total losses, induced sheath current, magnetic field around the power cable, positive and zero sequence harmonic impedances, as well as resonant frequencies. Also, a time-domain example derived from the frequency-domain analysis is provided. Remarkable results are obtained when comparing computed values and measurements, presenting the simplified ultra-shortened 3DFEM model as a valuable tool for the frequency-domain analysis of these cables.

The great expansion in offshore power plants is raising the concern regarding the cumulative effect of the electromagnetic field emissions caused by submarine power cables. In this sense, owners are required to predict these emissions during the permitting and consenting process of new power plants. This is a challenging task, especially in the case of HVAC three-core armored cables due to their complex geometry. Customarily, 2D approaches based on the finite element method (FEM) have been employed for evaluating the magnetic field emissions caused by these cables. However, inaccurate results are obtained since the phase conductors and armor twisting is omitted. This work develops, for the first time in the literature, an in-depth analysis of the magnetic field caused by this type of cable through an ultra-shortened 3D-FEM model, which is also faced to experimental measurements taken on an actual 132 kV, 800 mm2 three-core armored cable. Relevant conclusions are derived regarding the impact of the cable design on the magnetic field emissions, including material properties, as well as single and double-layer armors, presenting the proposed model not only as a valuable tool for predicting purposes, but also for optimizing cable design in terms of magnetic field emissions.

Due to recent advances, the numerical analysis of submarine three-core armored cables can nowadays be developed through the finite element method (FEM) in a small slice of the cable. This strongly reduces the computational burden and simulation time. However, the performance of this ultra-shortened 3D-FEM model is still to be fully assessed with experimental measurements. This paper focuses on this validation for an extensive variety of situations through the experimental measurements available in the specialized literature for up to 10 actual cables. In particular, it deals not only with relevant calculations at power frequency, like the series resistance and inductive reactance or the induced sheath current, but also with other aspects never analyzed before through 3D-FEM simulations, such as the zero sequence impedance, the magnetic field distribution around the power cable, as well as side effects due to the nonlinear properties of the armor wires. All this considering different armoring and sheath bonding configurations. Results show a very good agreement between measured and computed values, presenting the ultra-shortened 3D-FEM model as a suitable tool for the analysis and design of three-core armored cables, and opening the possibility to reduce the need of extensive experimental tests in the design stage of new cables.

In April and May 2021, Uppsala University Campus Gotland performed an archaeological investigation at Västergarn, 25 kilometres southwest of Visby, as part of an advanced field course in archaeology. Two trenches were investigated, covering an area of 90 m2. The purpose was to reinvestigate post-holes, remains of a wooden floor and a water hole unearthed in 2013. Further to understand how these remains relate to a number of Late Viking Age artefacts discovered in the same area. As a result it could be established that the wooden floor belongs to a medieval house foundation with corner-hearth and a partly preserved stone-lined sill. The foundation is mainly dated by shards of Baltic ware to the period 1100/1125-1230. Find concentrations of iron tools adjacent to the hearth, iron armory plates and glass beads may indicate a small workshop. The Viking Age artefacts relate to a separate post-hole building probably dated to the 11th century. The date and the function of the water hole remain inconclusive. The large amount of animal bones deposited in the stone paved water hole, among them a high proportion of horse bones indicates a function as a well for grazing cattle in the area during the dry season. A coin-like copper pendant with pseudo-Islamic glyphs found adjacent to the water hole underlines Viking Age activity in the area. The results show that the house remains in the area investigated probably belong to the outer precinct of the harbour settlement in Västergarn. This particular area within the Västergarn rampart was settled presumably between AD 1000/1050-1200/1230. Findings such as cultural layers, strengthens indications of a complex and active settlement in the late Viking and early medieval period., Snauvalds 1:2, Västergarn socken, Gotlands kommun, GotlandRAÄ nr: L1976:7960 (tidigare RAÄ-nr Västergarn 50:1)

The great expansion in offshore power plants is raising the concern regarding the cumulative effect of the electromagnetic field emissions caused by submarine power cables. In this sense, owners are required to predict these emissions during the permitting and consenting process of new power plants. This is a challenging task, especially in the case of HVAC three-core armored cables due to their complex geometry. Customarily, 2D approaches based on the finite element method (FEM) have been employed for evaluating the magnetic field emissions caused by these cables. However, inaccurate results are obtained since the phase conductors and armor twisting is omitted. This work develops, for the first time in the literature, an in-depth analysis of the magnetic field caused by this type of cable through an ultra-shortened 3D-FEM model, which is also faced to experimental measurements taken on an actual 132 kV, 800 mm2 three-core armored cable. Relevant conclusions are derived regarding the impact of the cable design on the magnetic field emissions, including material properties, as well as single and double-layer armors, presenting the proposed model not only as a valuable tool for predicting purposes, but also for optimizing cable design in terms of magnetic field emissions.

Due to recent advances, the numerical analysis of submarine three-core armored cables can nowadays be developed through the finite element method (FEM) in a small slice of the cable. This strongly reduces the computational burden and simulation time. However, the performance of this ultra-shortened 3D-FEM model is still to be fully assessed with experimental measurements. This paper focuses on this validation for an extensive variety of situations through the experimental measurements available in the specialized literature for up to 10 actual cables. In particular, it deals not only with relevant calculations at power frequency, like the series resistance and inductive reactance or the induced sheath current, but also with other aspects never analyzed before through 3D-FEM simulations, such as the zero sequence impedance, the magnetic field distribution around the power cable, as well as side effects due to the nonlinear properties of the armor wires. All this considering different armoring and sheath bonding configurations. Results show a very good agreement between measured and computed values, presenting the ultra-shortened 3D-FEM model as a suitable tool for the analysis and design of three-core armored cables, and opening the possibility to reduce the need of extensive experimental tests in the design stage of new cables.

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

The article deals with the possibility of increasing the damaging effects of small-caliber artillery ammunition in the fuel tanks of aircraft and helicopters. A comparison of the results of the calculation of the probability of the incendiary effect of strikers based on fluoropolymers on diesel fuel was made. The calculations were carried out using the methods of “Fragment Criterion” and “Energy Balance”. © 2021 Institute of Physics Publishing. All rights reserved.

Eis aqui uma interpretação da explanação de Heidegger dos fundamentos e desdobramentos do fenômeno do Niilismo, procedida pelo viés da fixação do sentido do Ser enquanto Maquinação. Esta interpretação implica a apresentação dos passos preparatórios do Filósofo para uma Escrita acerca do sentido do Ser orientada por um outro Princípio que o instituído pela Metafísica, e se faz a partir da contemplação de dois textos exemplares de Heidegger, em que ele investiga a determinação metafísica do Ser em dois períodos capitais da história do Pensamento: o período clássico da Metafísica grega, notadamente em Aristóteles, e o período consumado da Metafísica moderna, visado através da Filosofia de Nietzsche., Here is an interpretation of Heidegger's explanation of the fundamentals and developments of the phenomenon of Nihilism, proceeded by the fixation of the meaning of Being as Machination. This interpretation implies the presentation of the Philosopher's preparatory steps for a writing about the meaning of Being guided by another Principle than that instituted by Metaphysics, and it is made from the contemplation of two exemplary texts by Heidegger, in which he investigates the metaphysical determination of Being in two capital periods of the history of Thought: the classical period of Greek Metaphysics, notably in Aristotle, and the consummate period of modern Metaphysics, aimed at through Nietzsche's Philosophy

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

Eis aqui uma interpretação da explanação de Heidegger dos fundamentos e desdobramentos do fenômeno do Niilismo, procedida pelo viés da fixação do sentido do Ser enquanto Maquinação. Esta interpretação implica a apresentação dos passos preparatórios do Filósofo para uma Escrita acerca do sentido do Ser orientada por um outro Princípio que o instituído pela Metafísica, e se faz a partir da contemplação de dois textos exemplares de Heidegger, em que ele investiga a determinação metafísica do Ser em dois períodos capitais da história do Pensamento: o período clássico da Metafísica grega, notadamente em Aristóteles, e o período consumado da Metafísica moderna, visado através da Filosofia de Nietzsche., Here is an interpretation of Heidegger's explanation of the fundamentals and developments of the phenomenon of Nihilism, proceeded by the fixation of the meaning of Being as Machination. This interpretation implies the presentation of the Philosopher's preparatory steps for a writing about the meaning of Being guided by another Principle than that instituted by Metaphysics, and it is made from the contemplation of two exemplary texts by Heidegger, in which he investigates the metaphysical determination of Being in two capital periods of the history of Thought: the classical period of Greek Metaphysics, notably in Aristotle, and the consummate period of modern Metaphysics, aimed at through Nietzsche's Philosophy

Fish scales are laminated composites that consist of plies of unidirectional collagen fibrils with twisted-plywood stacking arrangement. Owing to their composition, the toughness of scales is dependent on the intermolecular bonding within and between the collagen fibrils. Adjusting the extent of this bonding with an appropriate stimulus has implications for the design of next-generation bioinspired flexible armours. In this investigation, scales were exposed to environments of water or a polar solvent (i.e. ethanol) to influence the extent of intermolecular bonding, and their mechanical behaviour was evaluated in uniaxial tension and transverse puncture. Results showed that the resistance to failure of the scales increased with loading rate in both tension and puncture and that the polar solvent treatment increased both the strength and toughness through interpeptide bonding; the largest increase occurred in the puncture resistance of scales from the tail region (a factor of nearly 7). The increase in strength and damage tolerance with stronger intermolecular bonding is uncommon for structural materials and is a unique characteristic of the low mineral content. Scales from regions of the body with higher mineral content underwent less strengthening, which is most likely the result of interference posed by the mineral crystals to intermolecular bonding. Overall, the results showed that flexible bioinspired composite materials for puncture resistance should enrol constituents and complementary processing that capitalize on interfibril bonds. © 2019 The Author(s) Published by the Royal Society. All rights reserved.

Natural dermal armors are serving as a source of inspiration in the pursuit of “next-generation” structural materials. Although the dynamic strain response of these materials is arguably the most relevant to their performance as armors, limited work has been performed in this area. Here, uniaxial tension and transverse puncture tests were performed on specimens obtained from the scales of Asian carp over strain rates spanning seven decades, from 10-4 to 103 s-1. The importance of anatomical variations was explored by comparing the performance of scales from the head, middle and tail regions. In both loading orientations, the scales exhibited a significant increase in the resistance to failure with loading rate. The rate sensitivity was substantially higher for transverse loading than for in-plane tension, with average strain rate sensitivity exponents for measures of the toughness of 0.35 and 0.08, respectively. Spatial variations in the properties were largest in the puncture responses, and scales from the head region exhibited the greatest resistance to puncture overall. The results suggest that the layered microstructure of fish scales is most effective at resisting puncture, rather than in-plane tension, and its effectiveness increases with rate of loading. X-ray microCT showed that delamination of plies in the internal elasmodine and stretching of the fibrils were key mechanisms of energy dissipation in response to puncture loading. Understanding contributions from the microstructure to this behavior could guide the development of flexible engineered laminates for penetration resistance and other related applications. © 2018 Elsevier Ltd

The present study exposes an analysis of the suspension system technical state evaluation for civil vehicles that have been subject to armouring processes. Such evaluation is performed through a mechanised revision established by state regulation and is based on the method defined by EuSAMA. The development of this analysis focuses on establishing the existing relation between the ballistic resistance integrated to a vehicle and the dynamic effect exercised for the modification of its mass, according to two reliability/safety driving measurement criteria: (i) tyre-road adhesion index and (ii) tyre excitation phase angle. The study proposes new elements to the current procedure established to evaluate the suspension of civil armoured cars considering the two measurement criteria, which can be acquired by a standard commercial suspension tester machine. Copyright © 2013 Inderscience Enterprises Ltd.

Fish scales exhibit a unique balance of flexibility, strength and toughness, which is essential to provide protection without encumbering locomotion. Although the mechanical behavior and structure of this natural armor are of recent interest, a comparison of these qualities from scales of different fish species has not been reported. In this investigation the armor of fish with different locomotion, size and protection needs were analyzed. Scales from the Arapaima gigas, the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio) were compared in terms of the stacking sequence of individual plies and their microstructure. The scales were also compared with respect to anatomical position to distinguish site-specific functional differences. Results show that the lamination sequence of plies for the carp and tarpon exhibit a Bouligand structure with relative rotation of 75 degrees between consecutive plies. The arapaima scales exhibit a cross-ply structure, with 90 degrees rotation between adjacent plies. In addition, results indicate that the volume fraction of reinforcement, the number of plies and the variations in thickness with anatomical position are unique amongst the three fish. These characteristics should be considered in evaluations focused on the mechanical behavior.

Animals have developed different strategies to protect themselves from environmental and predatory threats. One of these strategies concerns with the development of natural flexible dermal armor, usually consisting of rigid and highly mineralized units (e. g. scales or osteoderms) attached by flexible collagen fibers. These kinds of arrangements have been proven to achieve high flexibility without significant reduction in strength in comparison to monolithic structures. These are in fact features extremely valued by body armor users. This work studies the mechanical characteristics of scales and osteoderms of different animals (including mammals, reptiles and fishes), in order to compare them with other characteristics of the animal itself (like length and mobility) and characteristics of their predators like geometry and composition of their teeth and strength of bite. This comparison extends our knowledge and open new ways of understanding on how to design body armor materials and structures looking into improvements on flexibility and mobility. Copyright 2015. Used by the Society of the Advancement of Material and Process Engineering with permission.

Loss allocation of the three different components (conductor, sheaths and armor) of solidly bonded three-core separated lead-sheathed armored cables, frequently employed in offshore wind farms, is challenging due to the lack of accurate enough analytical expressions in the IEC standard. Also, loss allocation through experimental tests leads to inaccurate results since it is based on questionable assumptions. This paper improves both the IEC formulae and experimental methods by means of different analytical corrections in the conductor and sheath loss expressions. To this aim, an ad hoc application interface (Virtual Lab) based on 3D numerical simulations (finite element method) has been developed. This tool virtualizes and automates different test setups to emulate, in few seconds, the most employed experimental procedures in this type of cable. The analytical corrections have been derived from an in-depth analysis of a first set of 368 cables, ranging from 30 to 275 kV. The new loss expressions were successfully applied to a second set of 645 armored cables of quite diverse features (voltages from 10 to 275 kV, sections and dimensional parameters), hence bringing a general framework for any kind of three-core armored cable.

Low-alloy steels have been widely used as an armor material in defense systems due to their superior mechanical and weldability properties. In this study, microdamage formation in an AISI 4140 steel, which was hit by 7.62-mm armor-piercing (AP) projectile, was investigated. Analyses of the microstructure and microhardness after ballistic testing were performed to correlate the microstructure-property relationship. Two different types of adiabatic shear band (ASB) were observed in the tested samples. The experimental results indicated that the type and hardness of the bands were strongly related to the hardness and ballistic performance of the steel specimens., TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [106M211], This work was supported by the Research Fund of TUBITAK, Project # 106M211.

Dual phase steels have the potential to reduce the weight of structural components because of the improved mechanical properties obtained from the two phases: soft ferrite and hard martensite. In this study, the ballistic performance of a low carbon and low alloy steel was investigated in intercritically annealed conditions. To do this, intercritical heat treatments at three different temperatures were applied to the steel samples separately to get three groups of samples having various martensite volume fractions. The full annealing treatment was also performed on a fourth steel group sample for comparison with the dual phase samples. The ballistic testing was carried out using a 7.62 mm armor piercing (AP) projectile. The experimental results pointed out that the ballistic resistance of the dual phase steel increased by increasing martensite content. In addition, deformed shear bands and/or highly distorted microstructures were observed in all samples irrespective of heat treatment after the ballistic testing. Furthermore, there was a remarkable increase in the micro and macro hardness of the investigated steel samples due to the ballistic induced strain. (C) 2009 Elsevier B.V. All rights reserved., Research Fund of TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [106M211], This work was supported by the Research Fund of TUBITAK, Project # 106M211.

Laminated composites have great potential in producing lightweight armors. This study presents the experimental study of the low velocity ballistic behavior of Al(2)O(3)/Al2O24 (alumina/aluminum) laminated composites against 7.62 x 51 mm armor piercing (AP) projectiles. The effects of mechanical properties of backing material and laminating type as well as the adhesive type on the ballistic performance of the composite armor were investigated. Furthermore, an inspection of the fracture surfaces was carried out to analyze deformation mode by using a scanning electron microscope (SEM). The test results showed that utilization of alumina as a front layer and Al2O24-T6 as a backing layer in the composites with an alumina/aluminum thickness ratio in the range of 1-3 maintained the highest ballistic performance. Moreover, composites bonded with polyurethane exhibited more resistance to spalling of ceramic tiles than those bonded with epoxy, even though adhesive type had no appreciable effect on the ballistic performance of the composites. (c) 2007 Elsevier B.V. All rights reserved.

Low-alloy steels have been widely used as an armor material in defense systems due to their superior mechanical and weldability properties. In this study, microdamage formation in an AISI 4140 steel, which was hit by 7.62-mm armor-piercing (AP) projectile, was investigated. Analyses of the microstructure and microhardness after ballistic testing were performed to correlate the microstructure-property relationship. Two different types of adiabatic shear band (ASB) were observed in the tested samples. The experimental results indicated that the type and hardness of the bands were strongly related to the hardness and ballistic performance of the steel specimens., TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [106M211], This work was supported by the Research Fund of TUBITAK, Project # 106M211.

Dual phase steels have the potential to reduce the weight of structural components because of the improved mechanical properties obtained from the two phases: soft ferrite and hard martensite. In this study, the ballistic performance of a low carbon and low alloy steel was investigated in intercritically annealed conditions. To do this, intercritical heat treatments at three different temperatures were applied to the steel samples separately to get three groups of samples having various martensite volume fractions. The full annealing treatment was also performed on a fourth steel group sample for comparison with the dual phase samples. The ballistic testing was carried out using a 7.62 mm armor piercing (AP) projectile. The experimental results pointed out that the ballistic resistance of the dual phase steel increased by increasing martensite content. In addition, deformed shear bands and/or highly distorted microstructures were observed in all samples irrespective of heat treatment after the ballistic testing. Furthermore, there was a remarkable increase in the micro and macro hardness of the investigated steel samples due to the ballistic induced strain. (C) 2009 Elsevier B.V. All rights reserved., Research Fund of TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [106M211], This work was supported by the Research Fund of TUBITAK, Project # 106M211.

Laminated composites have great potential in producing lightweight armors. This study presents the experimental study of the low velocity ballistic behavior of Al(2)O(3)/Al2O24 (alumina/aluminum) laminated composites against 7.62 x 51 mm armor piercing (AP) projectiles. The effects of mechanical properties of backing material and laminating type as well as the adhesive type on the ballistic performance of the composite armor were investigated. Furthermore, an inspection of the fracture surfaces was carried out to analyze deformation mode by using a scanning electron microscope (SEM). The test results showed that utilization of alumina as a front layer and Al2O24-T6 as a backing layer in the composites with an alumina/aluminum thickness ratio in the range of 1-3 maintained the highest ballistic performance. Moreover, composites bonded with polyurethane exhibited more resistance to spalling of ceramic tiles than those bonded with epoxy, even though adhesive type had no appreciable effect on the ballistic performance of the composites. (c) 2007 Elsevier B.V. All rights reserved.

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

Eis aqui uma interpretação da explanação de Heidegger dos fundamentos e desdobramentos do fenômeno do Niilismo, procedida pelo viés da fixação do sentido do Ser enquanto Maquinação. Esta interpretação implica a apresentação dos passos preparatórios do Filósofo para uma Escrita acerca do sentido do Ser orientada por um outro Princípio que o instituído pela Metafísica, e se faz a partir da contemplação de dois textos exemplares de Heidegger, em que ele investiga a determinação metafísica do Ser em dois períodos capitais da história do Pensamento: o período clássico da Metafísica grega, notadamente em Aristóteles, e o período consumado da Metafísica moderna, visado através da Filosofia de Nietzsche., Here is an interpretation of Heidegger's explanation of the fundamentals and developments of the phenomenon of Nihilism, proceeded by the fixation of the meaning of Being as Machination. This interpretation implies the presentation of the Philosopher's preparatory steps for a writing about the meaning of Being guided by another Principle than that instituted by Metaphysics, and it is made from the contemplation of two exemplary texts by Heidegger, in which he investigates the metaphysical determination of Being in two capital periods of the history of Thought: the classical period of Greek Metaphysics, notably in Aristotle, and the consummate period of modern Metaphysics, aimed at through Nietzsche's Philosophy

Loss allocation of the three different components (conductor, sheaths and armor) of solidly bonded three-core separated lead-sheathed armored cables, frequently employed in offshore wind farms, is challenging due to the lack of accurate enough analytical expressions in the IEC standard. Also, loss allocation through experimental tests leads to inaccurate results since it is based on questionable assumptions. This paper improves both the IEC formulae and experimental methods by means of different analytical corrections in the conductor and sheath loss expressions. To this aim, an ad hoc application interface (Virtual Lab) based on 3D numerical simulations (finite element method) has been developed. This tool virtualizes and automates different test setups to emulate, in few seconds, the most employed experimental procedures in this type of cable. The analytical corrections have been derived from an in-depth analysis of a first set of 368 cables, ranging from 30 to 275 kV. The new loss expressions were successfully applied to a second set of 645 armored cables of quite diverse features (voltages from 10 to 275 kV, sections and dimensional parameters), hence bringing a general framework for any kind of three-core armored cable.

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Loss allocation through analytical expressions in three-core lead-sheathed armored cables is challenging due to the complex geometry of this type of cable, commonly employed in submarine energy transmission systems (involving twisted conductors, sheaths and armor). Most of the expressions of the IEC standard 60287 have not been properly adapted for three-core armored cables, leading to inaccurate values for the different losses, so important efforts are currently devoted to improving them. In this work, an improved ultra-shortened 3D finite element model (FEM) is employed for developing an in-depth analysis of the electromagnetic interactions that take place in 6 real cables, being especially focused on those aspects that are not considered in the IEC standard. As a result, important conclusions are derived regarding the losses in conductors and sheaths, which introduce different corrections for improving the accuracy of the IEC expressions. The new formulation is then employed to propose a simplified experimental armor loss allocation procedure. This is virtually applied through the FEM tool to more than 700 cable configurations, showing a remarkable improvement in the loss allocation over the IEC standard and previous experimental procedures.

The article presents the results of a study of the metallurgical characteristics of the armor of self-propelled artillery installations SU-122, SU-85, SU-100, produced at Uralmash, and T-34 tanks, produced by the Kharkov plant No. 183 and the Stalingrad tractor plant. The chemical composition, hardness, the nature of fractures, and the microstructure of the steel of individual armor elements of the investigated objects have been established. The data obtained, in general, correspond to the brand parameters of 8C armor steel. The effectiveness of portable devices for non-destructive testing of metals is shown when working at museum expositions., В статье представлены результаты исследования металловедческих характеристик брони самоходных артиллерийских установок СУ-122, СУ-85, СУ-100, произведенных на Уралмаше, и танков Т-34, произведенных Харьковским заводом №183 и Сталинградским тракторным заводом. Установлены химический состав, твердость, характер изломов, микроструктура стали отдельных элементов бронирования исследованных объектов. Полученные данные в целом соответствуют марочным параметрам броневой стали 8С. Показана эффективность переносных приборов неразрушающего контроля металлов при работе на музейных экспозициях.

This paper presents the main features of a 3D FEMbased modelling framework of submarine three-core power cables with the final aim of estimating the ampacity of this type of cables when operating at certain conditions (buried in the seabed in steady-state). This assessment provides valuable information for the cable manufacturer during the design stage and for the owner of the evacuation line mostly in the planning stage, apart from being used as a reference for the development of other less computationally intensive analytic models. Moreover, the paper analyzes the impact that some design parameters have on the temperature of the cable, providing same concluding remarks.

This paper presents the main features of a 3D FEMbased modelling framework of submarine three-core power cables with the final aim of estimating the ampacity of this type of cables when operating at certain conditions (buried in the seabed in steady-state). This assessment provides valuable information for the cable manufacturer during the design stage and for the owner of the evacuation line mostly in the planning stage, apart from being used as a reference for the development of other less computationally intensive analytic models. Moreover, the paper analyzes the impact that some design parameters have on the temperature of the cable, providing same concluding remarks.