Mareen N Warncke, Carola H. Böhmer, P. Böhnke, Ann-Malin Schmidt, A. Nocke, Johannes Mersch, Chokri Cherif
In the research field of smart textiles, one main goal concerns quantifying environmental forces acting on the wearer's body since textiles, acting as the boundary between the two, are an excellent way of integrating sensors. Integrating strain and pressure sensors into wearables promises a simple way of monitoring a person's posture and forces acting on their body. Sensors relying on a capacitive measuring principle are highly suitable for this, as they are less sensitive to changes in temperature than resistive or inductive types. In this paper, textile-based capacitive sensors are produced by braiding conductive yarns with and without an electrically insulating TPU sheath. The produced sensors are analyzed in cyclic strain and compression tests. Moreover, their behavior under changing temperatures is tested to prove their resilience against environmental changes. To extend their capabilities from an integral measurement to a localized assessment of the strain, time-domain-reflectometry (TDR) is employed. Finally, the sensors are integrated into a flexible actuated bending beam, and their adoption for soft robotics is discussed. Strain is tested cyclically, showing good long-term stability. Pressure sensitivity is measured in a static compression test under increasing force. TDR is used to localize strain in two discreet sections of the sensor. Although strain could not be quantified through TDR, characteristic points in the measured response signal indicating the position of the strain were identified. Textile-based capacitive sensors are suitable for strain up to 10 % and pressure up to 8 N. The determined gauge factors are satisfactory, with strain sensors inherently having a higher gauge factor than pressure sensors. Furthermore, they display good long-term stability and no adverse reaction to changes in temperature. TDR is proven to provide localization of strain in flexible sensors.
{"title":"Quantifying the Human Perception: Development and Characterization of Textile-Based Capacitive Strain and Pressure Sensors","authors":"Mareen N Warncke, Carola H. Böhmer, P. Böhnke, Ann-Malin Schmidt, A. Nocke, Johannes Mersch, Chokri Cherif","doi":"10.4028/p-sto4km","DOIUrl":"https://doi.org/10.4028/p-sto4km","url":null,"abstract":"In the research field of smart textiles, one main goal concerns quantifying environmental forces acting on the wearer's body since textiles, acting as the boundary between the two, are an excellent way of integrating sensors. Integrating strain and pressure sensors into wearables promises a simple way of monitoring a person's posture and forces acting on their body. Sensors relying on a capacitive measuring principle are highly suitable for this, as they are less sensitive to changes in temperature than resistive or inductive types. In this paper, textile-based capacitive sensors are produced by braiding conductive yarns with and without an electrically insulating TPU sheath. The produced sensors are analyzed in cyclic strain and compression tests. Moreover, their behavior under changing temperatures is tested to prove their resilience against environmental changes. To extend their capabilities from an integral measurement to a localized assessment of the strain, time-domain-reflectometry (TDR) is employed. Finally, the sensors are integrated into a flexible actuated bending beam, and their adoption for soft robotics is discussed. Strain is tested cyclically, showing good long-term stability. Pressure sensitivity is measured in a static compression test under increasing force. TDR is used to localize strain in two discreet sections of the sensor. Although strain could not be quantified through TDR, characteristic points in the measured response signal indicating the position of the strain were identified. Textile-based capacitive sensors are suitable for strain up to 10 % and pressure up to 8 N. The determined gauge factors are satisfactory, with strain sensors inherently having a higher gauge factor than pressure sensors. Furthermore, they display good long-term stability and no adverse reaction to changes in temperature. TDR is proven to provide localization of strain in flexible sensors.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140219946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salikh Omarov, Nurlan Nauryz, D. Talamona, Asma Perveen
Micro EDM is unconventional metal removing technique that is effective in machining hard-to-cut conductive materials. It has a big potential in modifying surfaces of metallic bone implants for better biocompatibility by providing proper surface topography to ease cell adhesion. However, it is still important to study machining performance. This paper investigates material removal rate (MRR) and surface roughness (SR) of micro WEDM on Ti-6Al-4V alloy. Three level Taguchi’s design was implemented to observe the effect of capacitance and gap voltage. Moreover, analysis of variance (ANOVA) and grey relation analysis (GRA) allowed to investigate contribution of each parameter and find their best combination for multiple output optimization. Results showed that highest MRR of 1.72*10-2 mm3/s can be achieved at 10 nF and 90 V values, while smallest SR of 0.309 µm can be achieved at 1nF and 90 V. In addition, the contribution and significance of capacitance on MRR and SR was considerably higher than the effect of gap voltage. Lastly, the optimal parameters for multiple output performance were calculated at 10 nF and 90 V values.
微电火花加工是一种非常规的金属去除技术，可有效加工难以切割的导电材料。它通过提供适当的表面形貌以促进细胞粘附，在改造金属骨植入物表面以提高生物相容性方面具有巨大潜力。然而，研究加工性能仍然非常重要。本文研究了对 Ti-6Al-4V 合金进行微线切割加工的材料去除率（MRR）和表面粗糙度（SR）。采用田口三水平设计来观察电容和间隙电压的影响。此外，方差分析（ANOVA）和灰色关系分析（GRA）可用于研究各参数的贡献，并为多输出优化找到最佳组合。结果表明，在 10 nF 和 90 V 条件下，MRR 最高，可达 1.72*10-2 mm3/s；在 1 nF 和 90 V 条件下，SR 最小，可达 0.309 µm。最后，计算了 10 nF 和 90 V 电压下多重输出性能的最佳参数。
{"title":"Optimization of µ-WEDM Parameters for MRR and SR on Ti-6Al-4V","authors":"Salikh Omarov, Nurlan Nauryz, D. Talamona, Asma Perveen","doi":"10.4028/p-wydlt9","DOIUrl":"https://doi.org/10.4028/p-wydlt9","url":null,"abstract":"Micro EDM is unconventional metal removing technique that is effective in machining hard-to-cut conductive materials. It has a big potential in modifying surfaces of metallic bone implants for better biocompatibility by providing proper surface topography to ease cell adhesion. However, it is still important to study machining performance. This paper investigates material removal rate (MRR) and surface roughness (SR) of micro WEDM on Ti-6Al-4V alloy. Three level Taguchi’s design was implemented to observe the effect of capacitance and gap voltage. Moreover, analysis of variance (ANOVA) and grey relation analysis (GRA) allowed to investigate contribution of each parameter and find their best combination for multiple output optimization. Results showed that highest MRR of 1.72*10-2 mm3/s can be achieved at 10 nF and 90 V values, while smallest SR of 0.309 µm can be achieved at 1nF and 90 V. In addition, the contribution and significance of capacitance on MRR and SR was considerably higher than the effect of gap voltage. Lastly, the optimal parameters for multiple output performance were calculated at 10 nF and 90 V values.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 81","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140213057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carola H. Böhmer, Mareen N Warncke, P. Böhnke, A. Nocke, Johannes Mersch, Iris Kruppke, Chokri Cherif
Current research focuses on advancements and breakthroughs in the realm of smart textiles, with applications spanning various industries such as medicine and education. For producing flexible smart textiles, electrically conductive yarns (EC) are needed to transmit signals or as part of sensor systems. Mostly, these EC consist of a polymer core with an outer metallized layer. Using EC in contact with skin requires high reliability and safety, and thus, the EC must maintain their functional properties on a long-term scale under a range of different stresses. The electrical properties of EC deteriorate under mechanical stress applied during production or in-use through damage to the yarn’s surface. At present, there are only partially feasible solutions to protect the metal-layer of the yarn surface. Hence, this paper presents a newly developed non-toxic coating (NTC) to protect the EC surface. The NTC consists of an aqueous emulsion with polypropylene wax and oxidized wax. To determine the long-term stability of the coating, the produced yarns undergo comprehensive evaluation using a range of analytical techniques. The aim is to identify the optimal coating by exploring different equipment and parameters. Additionally, it is various test methods to gauge the durability of the newly developed NTC used and ensure its reliability over time. To characterize the yarn properties before and after the coating, light microscopy (LM), washing processes, mechanical resistance tests and resistivity measurement are conducted.
{"title":"Environmentally Friendly Protective Coating for Electrically Conductive Yarns Using in Smart Textiles","authors":"Carola H. Böhmer, Mareen N Warncke, P. Böhnke, A. Nocke, Johannes Mersch, Iris Kruppke, Chokri Cherif","doi":"10.4028/p-ah5mgx","DOIUrl":"https://doi.org/10.4028/p-ah5mgx","url":null,"abstract":"Current research focuses on advancements and breakthroughs in the realm of smart textiles, with applications spanning various industries such as medicine and education. For producing flexible smart textiles, electrically conductive yarns (EC) are needed to transmit signals or as part of sensor systems. Mostly, these EC consist of a polymer core with an outer metallized layer. Using EC in contact with skin requires high reliability and safety, and thus, the EC must maintain their functional properties on a long-term scale under a range of different stresses. The electrical properties of EC deteriorate under mechanical stress applied during production or in-use through damage to the yarn’s surface. At present, there are only partially feasible solutions to protect the metal-layer of the yarn surface. Hence, this paper presents a newly developed non-toxic coating (NTC) to protect the EC surface. The NTC consists of an aqueous emulsion with polypropylene wax and oxidized wax. To determine the long-term stability of the coating, the produced yarns undergo comprehensive evaluation using a range of analytical techniques. The aim is to identify the optimal coating by exploring different equipment and parameters. Additionally, it is various test methods to gauge the durability of the newly developed NTC used and ensure its reliability over time. To characterize the yarn properties before and after the coating, light microscopy (LM), washing processes, mechanical resistance tests and resistivity measurement are conducted.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 88","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140213454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. D. Koçak, Pelin Altay, Melisa Suha Aksaman, Melike Ateş, Zeynep Ünver
The textile industry is responsible for producing a significant amount of global CO2 emission, which is the biggest contributor to global warming and climate change. Researchers have focused on reducing greenhouse gas emission by recycling textile materials rather than producing new fibers through circular economy approaches. Using recycled fibers or blending new fibers with recycled fibers is becoming an essential approach to strike a balance between textile quality and sustainability. In this study, swimwear fabrics made of 100% polyester, and 50% polyester-50% recycled polyester fiber were investigated in terms of their performance properties including color fastness, abrasion resistance, and seam strength. This study will provide a better understanding of the effect of the polyester fiber and recycled polyester fiber combination on the performance/quality properties of swimwear fabrics.
{"title":"Performance Properties of Swimwear Fabrics Produced from Polyester and Recycled Polyester Fiber","authors":"E. D. Koçak, Pelin Altay, Melisa Suha Aksaman, Melike Ateş, Zeynep Ünver","doi":"10.4028/p-imno45","DOIUrl":"https://doi.org/10.4028/p-imno45","url":null,"abstract":"The textile industry is responsible for producing a significant amount of global CO2 emission, which is the biggest contributor to global warming and climate change. Researchers have focused on reducing greenhouse gas emission by recycling textile materials rather than producing new fibers through circular economy approaches. Using recycled fibers or blending new fibers with recycled fibers is becoming an essential approach to strike a balance between textile quality and sustainability. In this study, swimwear fabrics made of 100% polyester, and 50% polyester-50% recycled polyester fiber were investigated in terms of their performance properties including color fastness, abrasion resistance, and seam strength. This study will provide a better understanding of the effect of the polyester fiber and recycled polyester fiber combination on the performance/quality properties of swimwear fabrics.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 46","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140216443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Tomljenović, I. Kazani, Jonida Haskurti, Juro Živičnjak, Ivan Kraljević, Z. Skenderi
Socks, being a necessary item of clothing, must be comfortable and maintain their quality throughout their life. Therefore, it is very important to select the yarns for their production. Usually, casual socks are made from a high percentage of cotton to ensure softness and comfort, and blended with polyamide to improve fit, durability and shrink resistance. The objective of this study is to compare five groups of black colored cotton calf-length men's socks produced under the same conditions in full plating with different textured polyamide 6.6 multifilament yarns, designated as: 22 dtex f7 × 2, 33 dtex f10 × 2, 44 dtex f13 × 2, 78 dtex f23 × 2, 110 dtex f34 × 2. The influence of the linear density of the polyamide plating yarn on the usage properties of the socks was evaluated by testing abrasion resistance and propensity to surface pilling with the Martindale abrasion and pilling tester, dimensional stability and color fastness to washing, perspiration and rubbing, as well as on comfort-related properties by testing moisture absorption, air permeability and thermal resistance with the Thermal foot manikin system. In addition, the basic physical properties of the socks, consisting of density parameters, mass and thickness were measured, all according to the standardized test methods. The results show that increasing the linear density of polyamide 6.6 yarns (i.e., increasing the amount of polyamide in the socks) has the following effects: increase in mass, thickness and structural change of sock plain knits, increase in abrasion resistance and change in dimensional stability of socks, decrease in moisture absorption, air permeability and thermal comfort of socks. From the obtained results, it can be concluded that when selecting the plating yarn for the production of cotton socks, it is necessary to take into account their linear density and structure, as well as the intended purpose of the socks, their specified comfort and the expected usage quality.
{"title":"Influence of Linear Density of Polyamide Plating Yarn on the Usage and Comfort Properties of Men’s Cotton Socks","authors":"A. Tomljenović, I. Kazani, Jonida Haskurti, Juro Živičnjak, Ivan Kraljević, Z. Skenderi","doi":"10.4028/p-d58bla","DOIUrl":"https://doi.org/10.4028/p-d58bla","url":null,"abstract":"Socks, being a necessary item of clothing, must be comfortable and maintain their quality throughout their life. Therefore, it is very important to select the yarns for their production. Usually, casual socks are made from a high percentage of cotton to ensure softness and comfort, and blended with polyamide to improve fit, durability and shrink resistance. The objective of this study is to compare five groups of black colored cotton calf-length men's socks produced under the same conditions in full plating with different textured polyamide 6.6 multifilament yarns, designated as: 22 dtex f7 × 2, 33 dtex f10 × 2, 44 dtex f13 × 2, 78 dtex f23 × 2, 110 dtex f34 × 2. The influence of the linear density of the polyamide plating yarn on the usage properties of the socks was evaluated by testing abrasion resistance and propensity to surface pilling with the Martindale abrasion and pilling tester, dimensional stability and color fastness to washing, perspiration and rubbing, as well as on comfort-related properties by testing moisture absorption, air permeability and thermal resistance with the Thermal foot manikin system. In addition, the basic physical properties of the socks, consisting of density parameters, mass and thickness were measured, all according to the standardized test methods. The results show that increasing the linear density of polyamide 6.6 yarns (i.e., increasing the amount of polyamide in the socks) has the following effects: increase in mass, thickness and structural change of sock plain knits, increase in abrasion resistance and change in dimensional stability of socks, decrease in moisture absorption, air permeability and thermal comfort of socks. From the obtained results, it can be concluded that when selecting the plating yarn for the production of cotton socks, it is necessary to take into account their linear density and structure, as well as the intended purpose of the socks, their specified comfort and the expected usage quality.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 44","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140212557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The goal of the current study was to develop pantyhose that reduce leg muscle fatigue when heeled shoes are worn. To this end, pantyhose that provide a comfortable fitting sensation were developed, and the wear experience of the pantyhose and the effect of the pantyhose on energy consumption under walking muscle activity of the lower limbs were investigated. The study participants were 17 healthy Japanese females in their twenties who did not usually put on support wear. The respiratory metabolism was measured as the participants either walked without pantyhose or wore one of two types of pantyhose and wore three types of shoe, namely running/low-heeled/high-heeled shoes. Participants walked on a treadmill at 3 km/h. Regardless of whether pantyhose were worn, the energy consumption increased significantly with walking relative to standing. During walking, energy consumption increased significantly in the order of not wearing shoes, wearing running shoes, wearing low-heeled shoes, and wearing high-heeled shoes. In other words, a higher heel height corresponded to higher energy consumption, regardless of whether pantyhose were worn. Wearing pantyhose while standing upright increased energy consumption, especially in the case of pantyhose A, for which energy consumption was significantly higher than that when going barefoot. In addition, for walking in running shoes, the energy consumption was significantly higher when pantyhose A were worn than when no pantyhose were worn. The wearing of pantyhose A, but not the wearing of pantyhose B, was thus found to increase energy consumption.
本研究的目标是开发能够减轻穿高跟鞋时腿部肌肉疲劳的连裤袜。为此，研究人员开发了具有舒适合脚感的连裤袜，并调查了连裤袜的穿着体验以及连裤袜对下肢步行肌肉活动能量消耗的影响。研究对象是 17 名 20 多岁的健康日本女性，她们通常不穿支撑服。研究人员在不穿连裤袜或穿两种连裤袜中的一种并穿三种鞋（即跑步鞋、低跟鞋和高跟鞋）的情况下进行了呼吸代谢测量。参与者在跑步机上以 3 公里/小时的速度行走。无论是否穿着连裤袜，行走时的能量消耗都比站立时显著增加。在行走过程中，能量消耗按照不穿鞋、穿跑鞋、穿低跟鞋和穿高跟鞋的顺序明显增加。换句话说，无论是否穿着连裤袜，鞋跟高度越高，能量消耗越大。直立行走时穿连裤袜会增加能量消耗，尤其是连裤袜 A 的能量消耗明显高于赤脚行走时的能量消耗。此外，穿着跑鞋行走时，穿连裤袜 A 的能耗明显高于不穿连裤袜的能耗。因此，穿连裤袜 A 而不穿连裤袜 B 会增加能量消耗。
{"title":"Energy Consumption during the Wearing of Pantyhose","authors":"Sayuki Kondo, T. Mitsuno","doi":"10.4028/p-jlq1ii","DOIUrl":"https://doi.org/10.4028/p-jlq1ii","url":null,"abstract":"The goal of the current study was to develop pantyhose that reduce leg muscle fatigue when heeled shoes are worn. To this end, pantyhose that provide a comfortable fitting sensation were developed, and the wear experience of the pantyhose and the effect of the pantyhose on energy consumption under walking muscle activity of the lower limbs were investigated. The study participants were 17 healthy Japanese females in their twenties who did not usually put on support wear. The respiratory metabolism was measured as the participants either walked without pantyhose or wore one of two types of pantyhose and wore three types of shoe, namely running/low-heeled/high-heeled shoes. Participants walked on a treadmill at 3 km/h. Regardless of whether pantyhose were worn, the energy consumption increased significantly with walking relative to standing. During walking, energy consumption increased significantly in the order of not wearing shoes, wearing running shoes, wearing low-heeled shoes, and wearing high-heeled shoes. In other words, a higher heel height corresponded to higher energy consumption, regardless of whether pantyhose were worn. Wearing pantyhose while standing upright increased energy consumption, especially in the case of pantyhose A, for which energy consumption was significantly higher than that when going barefoot. In addition, for walking in running shoes, the energy consumption was significantly higher when pantyhose A were worn than when no pantyhose were worn. The wearing of pantyhose A, but not the wearing of pantyhose B, was thus found to increase energy consumption.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140215769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Transition metal dichalcogenides (TMDCs) nanomaterials, in particular Molybdenum disulfide (MoS2), have been employed frequently as a basis for flexible gas sensors due to their extreme sensitivity to gas molecules, super mechanical and electrical properties, and large surface area. This work aims to study the behavior of the flexible gas sensor made of 2D-MoS2 under exposure to nitrogen dioxide (NO2) gas at the part per million (ppm) level. The mono-layered MoS2 was successfully synthesized by Chemical Vapor Deposition (CVD). The formation of MoS2 layers was confirmed by Raman spectroscopy and Photoluminescence (PL). Two different gas-sensing devices were fabricated by transferring two MoS2 samples (obtained from two positions inside the CVD tube) onto paper substrates. Specifically, upstream sample Sup was obtained from an area near the MoO3 source, and downstream sample Sdown was obtained from an area far from the MoO3 source. Both sensors showed a good response to a concentration as low as (1.5 ppm) of NO2. Although a high response of 62.8% along with a fast response of 9 sec were recorded by Sdown, the sensor showed a slow recovery time of 42 sec. On the other hand, Sup showed good stability with an appropriate response of 36.8% along with a reasonable response time and recovery times of 20 and 27 sec, respectively. Such behavior could be accredited to the difference in the reactivity in both MoS2 samples. This work opens the way for further improvements in manufacturing MoS2-based flexible gas sensors.
{"title":"Flexible and Disposable Gas Sensors Based on Two-Dimensional Materials","authors":"Farah Ma'ashi, A. Aljarb, H. Al‐Jawhari","doi":"10.4028/p-15qup9","DOIUrl":"https://doi.org/10.4028/p-15qup9","url":null,"abstract":"Transition metal dichalcogenides (TMDCs) nanomaterials, in particular Molybdenum disulfide (MoS2), have been employed frequently as a basis for flexible gas sensors due to their extreme sensitivity to gas molecules, super mechanical and electrical properties, and large surface area. This work aims to study the behavior of the flexible gas sensor made of 2D-MoS2 under exposure to nitrogen dioxide (NO2) gas at the part per million (ppm) level. The mono-layered MoS2 was successfully synthesized by Chemical Vapor Deposition (CVD). The formation of MoS2 layers was confirmed by Raman spectroscopy and Photoluminescence (PL). Two different gas-sensing devices were fabricated by transferring two MoS2 samples (obtained from two positions inside the CVD tube) onto paper substrates. Specifically, upstream sample Sup was obtained from an area near the MoO3 source, and downstream sample Sdown was obtained from an area far from the MoO3 source. Both sensors showed a good response to a concentration as low as (1.5 ppm) of NO2. Although a high response of 62.8% along with a fast response of 9 sec were recorded by Sdown, the sensor showed a slow recovery time of 42 sec. On the other hand, Sup showed good stability with an appropriate response of 36.8% along with a reasonable response time and recovery times of 20 and 27 sec, respectively. Such behavior could be accredited to the difference in the reactivity in both MoS2 samples. This work opens the way for further improvements in manufacturing MoS2-based flexible gas sensors.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140216118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shei Li Chung, Wei Meng Lim, Chee Onn Leong, M. Yee
Pancreatic cancer, often referred to as “the silent killer”, presents with minimal or no symptoms in its early stages, leading to late detection when surgical resection is no longer the optimal treatment option. Gemcitabine (GEM), one of the leading chemotherapeutic drug for advanced stages of cancer, is a crucial treatment for pancreatic cancer. However, the low 5-year survival rate of pancreatic cancer patients highlight the limited effectiveness of current treatments. In recent years, mesoporous silica nanoparticles (MSNP) have garnered significant attention in both scholarly and pharmaceutical fields due to their unique combination of properties including stable porous structure and high loading capacities. This research aims to investigate the potential of MSNP as a carrier for anticancer drugs, specifically GEM. MSNP was successfully synthesized in the laboratory using sol-gel method with tetraethyl orthosilicate (TEOS) as silica source and cetyltrimethylammonium bromide (CTAB) as surfactant template. Comprehensive morphological and physical characterizations of the MSNP product were performed through transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, element mapping, X-ray diffractometry (XRD), and accelerated surface area porosimetry (ASAP). The results demonstrate that MSNP exhibits desirable properties for drug loading, including a stable mesoporous structure with pore size of ~ 4.94 nm, a high surface area of about 278.32 m²/g, and average particle diameter of approximately 85 nm. The effects of incubation time and initial GEM concentrations were studied to determine the optimal drug loading parameters for the MSNP vehicle. The successful loading of up to 24 µg of GEM in 1 mg of MSNP achieved in an optimized incubation time of 2 hour, validates the tremendous potential of MSNP as a potential anticancer drug carrier in pancreatic cancer treatment. These findings provide a valuable reference for future research and investigations in this promising field.
{"title":"Optimisation Studies of Mesoporous Silica Nanoparticle as a Drug Carrier for Gemcitabine: Enhancing Therapeutic Effectiveness in Pancreatic Cancer","authors":"Shei Li Chung, Wei Meng Lim, Chee Onn Leong, M. Yee","doi":"10.4028/p-pdci7g","DOIUrl":"https://doi.org/10.4028/p-pdci7g","url":null,"abstract":"Pancreatic cancer, often referred to as “the silent killer”, presents with minimal or no symptoms in its early stages, leading to late detection when surgical resection is no longer the optimal treatment option. Gemcitabine (GEM), one of the leading chemotherapeutic drug for advanced stages of cancer, is a crucial treatment for pancreatic cancer. However, the low 5-year survival rate of pancreatic cancer patients highlight the limited effectiveness of current treatments. In recent years, mesoporous silica nanoparticles (MSNP) have garnered significant attention in both scholarly and pharmaceutical fields due to their unique combination of properties including stable porous structure and high loading capacities. This research aims to investigate the potential of MSNP as a carrier for anticancer drugs, specifically GEM. MSNP was successfully synthesized in the laboratory using sol-gel method with tetraethyl orthosilicate (TEOS) as silica source and cetyltrimethylammonium bromide (CTAB) as surfactant template. Comprehensive morphological and physical characterizations of the MSNP product were performed through transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, element mapping, X-ray diffractometry (XRD), and accelerated surface area porosimetry (ASAP). The results demonstrate that MSNP exhibits desirable properties for drug loading, including a stable mesoporous structure with pore size of ~ 4.94 nm, a high surface area of about 278.32 m²/g, and average particle diameter of approximately 85 nm. The effects of incubation time and initial GEM concentrations were studied to determine the optimal drug loading parameters for the MSNP vehicle. The successful loading of up to 24 µg of GEM in 1 mg of MSNP achieved in an optimized incubation time of 2 hour, validates the tremendous potential of MSNP as a potential anticancer drug carrier in pancreatic cancer treatment. These findings provide a valuable reference for future research and investigations in this promising field.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140218511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper deals with the problem of stress in the connection detail of vertical supporting structures with a flat slab and possible methods for its analysis. It mainly focuses on the problem of non-axial connection of columns and walls, which is typical for today's architectural designs. The parametric study compares the effect of the distance of the connected vertical support structures on reinforcement in the discontinuity region. Three different computational methods are used to stress analysis of this region - linear Finite Elements Method in SCIA Engineer software, 2D Strut-and-Tie Model and 2D non-linear Finite Elements Method in IDEA StatiCa software. The conclusion of the study is a comparison of the accuracy of different calculation methods and also a comparison of the solved design variants in terms of shear and bending stress and specific form of reinforcement.
本文论述了带有平板的垂直支撑结构连接细节中的应力问题及其可能的分析方法。论文主要关注柱和墙的非轴向连接问题，这是当今建筑设计中的典型问题。参数研究比较了连接垂直支撑结构的距离对不连续区域加固的影响。该区域的应力分析采用了三种不同的计算方法--SCIA Engineer 软件中的线性有限元法、二维支柱和拉杆模型以及 IDEA StatiCa 软件中的二维非线性有限元法。这项研究的结论是比较不同计算方法的准确性，并从剪应力、弯曲应力和具体加固形式的角度对已解决的设计变量进行比较。
{"title":"Analysis of Position Effect of Vertical Load-Bearing Elements for Reinforcement of Steel Reinforced Concrete Floor Structures","authors":"M. Tipka, Tadeáš Maceček, J. Vašková","doi":"10.4028/p-jmrgs4","DOIUrl":"https://doi.org/10.4028/p-jmrgs4","url":null,"abstract":"The paper deals with the problem of stress in the connection detail of vertical supporting structures with a flat slab and possible methods for its analysis. It mainly focuses on the problem of non-axial connection of columns and walls, which is typical for today's architectural designs. The parametric study compares the effect of the distance of the connected vertical support structures on reinforcement in the discontinuity region. Three different computational methods are used to stress analysis of this region - linear Finite Elements Method in SCIA Engineer software, 2D Strut-and-Tie Model and 2D non-linear Finite Elements Method in IDEA StatiCa software. The conclusion of the study is a comparison of the accuracy of different calculation methods and also a comparison of the solved design variants in terms of shear and bending stress and specific form of reinforcement.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":"347 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140232945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glassfibre reinforced concrete (GRC) is a close-grained concrete material reinforced with glass fibres that allows architects complete freedom in designing rear-ventilated façades. It can be shaped, coloured, surface-treated or otherwise tailored to the specific needs of their projects without significant limitations. The main properties of GRC material include its long life-time and sustainability. The results are visually appealing façade panels that can withstand adverse weather conditions for decades. The characteristic high strength and durability is achieved by dispersing glass fibres within the base mixture of Portland cement, sand, water and further refining additives. Fine-grained particles in the composite structure ensure low water absorbency and high frost resistance. This article is an overview of the technical solution and process of GRC façade design. It deals with the design possibilities for anchoring large-format and 3D shaped façade panels. The article further presents all of the above-mentioned characteristics and process details as they are used on three specific structures. The first presented project is the ČSOB Central Office in Hradec Králové, with its typical distinct ledges combined with glazed surfaces. The cascading entrance portal is a significant element of its façade. The next implementation chosen is the renovation of the C&A department store building in Zürich, Switzerland. This building’s façade is comprised of structured large-area panels with distinctive frames. The article concludes with the creatively implemented renovation of the Illuster shopping centre in Switzerland, with its kaleidoscopic façade made up of glassfibre reinforced concrete panels.
{"title":"Implementation of Large-Format 3D Façade Components Using Glass Fibre Reinforced Concrete:ČSOB Hradec Králové, C&A Zürich, Illuster Uster","authors":"Klara Janousova","doi":"10.4028/p-vdqaw7","DOIUrl":"https://doi.org/10.4028/p-vdqaw7","url":null,"abstract":"Glassfibre reinforced concrete (GRC) is a close-grained concrete material reinforced with glass fibres that allows architects complete freedom in designing rear-ventilated façades. It can be shaped, coloured, surface-treated or otherwise tailored to the specific needs of their projects without significant limitations. The main properties of GRC material include its long life-time and sustainability. The results are visually appealing façade panels that can withstand adverse weather conditions for decades. The characteristic high strength and durability is achieved by dispersing glass fibres within the base mixture of Portland cement, sand, water and further refining additives. Fine-grained particles in the composite structure ensure low water absorbency and high frost resistance. This article is an overview of the technical solution and process of GRC façade design. It deals with the design possibilities for anchoring large-format and 3D shaped façade panels. The article further presents all of the above-mentioned characteristics and process details as they are used on three specific structures. The first presented project is the ČSOB Central Office in Hradec Králové, with its typical distinct ledges combined with glazed surfaces. The cascading entrance portal is a significant element of its façade. The next implementation chosen is the renovation of the C&A department store building in Zürich, Switzerland. This building’s façade is comprised of structured large-area panels with distinctive frames. The article concludes with the creatively implemented renovation of the Illuster shopping centre in Switzerland, with its kaleidoscopic façade made up of glassfibre reinforced concrete panels.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":"299 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140233034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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