• Advances in concrete construction
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• 제5권2호
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• pp.87-99
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• 2017

After passing through a magnetic field, the physical quality of water improves, and magnetic water (MW) is produced. There are many investigations on the effects of magnetic field on water that shows MW properties like saturation and memory effect. This study investigates the fresh and hardened properties of concrete mixed with MW, which contains silica fume (SF) and superplasticizer (SP). The test variables included the magnetic field intensity for producing MW (three kinds of water), SF content replaced cement (0 and 10 percent), water-to-cementitious materials ratio (W/CM=0.25, 0.35 and 0.45) and curing time (7, 28 and 90 days). The results of this study show that MW had a positive impact on the workability and compressive strength of concrete. By rising the intensity of the magnetic field which was used for producing MW, its positive influence on both workability and compressive strength improved. MW had greater positive impacts on samples containing SP that did not have SF. Moreover, the best compressive strength improvements of concrete achieved as W/CM ratio decreased.

• Computers and Concrete
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• 제31권2호
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• pp.97-110
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• 2023

This study investigates experimentally the impact of magnetized water (MW) on the fresh and hardened characteristics of concrete. Five types of MW are produced using magnetic fields of 1.4 and 1.6 Tesla for treating water with 100, 150, and 250 cycles. The concrete properties are assessed using the slump test, compressive strength test, scanning electron microscopy (SEM) analysis, energy dispersive X-ray analysis (EDX), and Fourier transform infrared spectrophotometry (FTIR). Furthermore, the chemical-physical characteristics of tap water (TW) and MW are evaluated. The results showed the magnetic field intensity has a significant impact on the magnetization effect; the best magnetizing conditions were found when TW was exposed successively to magnetic fields of 1.6 T and 1.4 T for 150 cycles. In addition, 150 MW cycles can be used to improve the compressive strength and workability of concrete by 40% and 17%, respectively. pH, total dissolved solids, and electrical conductivity improved by 15%, 17%, and 7%, respectively, when using MW. Additionally, MW can be used to enhance cement hydration chemical processes and made concrete's structure denser.

• Computers and Concrete
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• 제21권2호
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• pp.199-207
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• 2018

With the development of concrete technology, producing concrete products that have the ability to flow under their own weights and do not need internal or external vibrations is an important achievement. In this study, assessments are made on using travertine, marble and limestone rock flours in self-compacting lightweight concrete (SCLC). In fact, the effects of these powders on plastic and hardened phases of SCLC are studied. To address this issue, concrete mixtures with water to cementitious materials ratios of 0.42 and 0.45 were used. These mixtures were made with 0 and 10% silica fume (SF) replacement levels by cement weight. To achieve lightweight concrete, lightweight expanded clay aggregate (Leca) with the bulk density of about $520kg/m^3 $was utilized. Also two kinds of water were consumed involving tap water and magnetic water (MW) for investigating the possible interaction of MW and rock flour type. In this study, 12 mixtures were studied, and their specific weights were in the range of $1660-1692kg/m^3$. To study the mixtures in plastic phase, tests such as slump flow, J-ring, V-funnel and U-box were performed. By using marble and travertine powders instead of limestone flour, the plastic viscosities and rheology were not changed considerably and they remained in the range of regulations. Moreover, SCLC showed better compressive strength with travertine, and then with marble rock flours compared to limestone powders. According to the results of the conducted study, MW showed better performance in both fresh and hardened phases in all the mixes, and there was no interaction between MW and rock flour type.

• 한국초전도ㆍ저온공학회논문지
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• 제7권3호
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• pp.21-28
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• 2005

Superconducting synchronous motors and generators have the field coil composed of superconductor with almost zero resistance at superconducting state. Therefore, copper loss at the conventional field coil is eliminated and the superconducting machine gets higher efficiency. The armature coil of the superconducting machine is composed of copper wire and supported by non-magnetic material such as FRP (Fiber Reinforced Plastic) This paper contains the design Procedure of a 1MW superconducting synchronous motor using high-temperature superconductor only for the field coil. Especially, the armature coil is designed by water-cooling in order to dissipate Joule heat easily. Moreover, 3-dimensional electromagnetic design is conducted to get a proper design result and reduce design errors from 2-dimensional approach.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1258-1260
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• 2005

Superconducting synchronous motors and generators have the field coil composed of superconductor with almost zero resistance at superconducting state. Therefore, co or loss at the conventional field coil is eliminated and the superconducting machine gets higher efficiency. The armature coil of the superconducting machine is composed of cower wire and supported by non-magnetic material such as FRP(Fiber Reinforced Plastic). Although a fully-superconducting machine with superconducting armature coil has been researched, it was not developed toward industrial application because of AC transporting loss and difficulty in construction of the cooling structure and so on. This paper contains the design procedure of a 1 MW superconducting synchronous motor using high-temperature superconductor only for the field coil. Especially, the armature coil is designed by water-cooling in order to dissipate Joule heat easily. Moreover, 3-dimensional electromagnetic design is conducted to get a proper design result and reduce design errors from 2-dimensional approach.

• Journal of Nutrition and Health
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• 제49권6호
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• pp.401-410
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• 2016

자화수는 가격이 비싸지 않고 쉽게 만들 수 있으며 환경 친화적인 음용수임에도 불구하고 자화수 섭취의 건강상의 유익에 관해서는 과학적인 문헌이 매우 제한적이다. 본 연구는 유전적 소인에 의해 제2형 당뇨병이 발현되는 모델인 db/db 마우스 6주령 14마리를 당뇨군과 자화수군으로 나누어 각 7마리씩 배치하고, 이형접합체 마우스 10마리를 대조군으로 하여 총 3군으로 나누어 16주 동안 자화수를 투여하였다. 혈당 강하 효과를 보기 위해 공복혈당, 인슐린 농도, 내당능 검사, 당화 헤모글로빈을 측정 하였고, DNA 손상 감소 효과, 항산화 상태를 알아보았다. 당뇨군과 자화수군의 혈당치는 대조군에 비해 유의적으로 높았으며, 당뇨군의 혈당은 자화수 섭취 16주까지 높게 지속되었으나 자화수군의 혈당은 섭취 10주 후부터 유의적으로 감소하였다. 혈중 당화헤모글로빈 함량도 마찬가지로 대조군보다 당뇨군에서 증가하였고 자화수군에서는 유의적으로 감소하였으나 경구 당부하 검사 결과, 혈당 곡선하면적 (area under the curve, AUC)은 당뇨군과 자화수 투여군 사이에 유의적인 차이를 보이지 않았다. 당뇨쥐의 DNA 손상 정도는 세 가지 지표 (DNA in tail, tail length, tail moment) 모두 자화수군이 당뇨군에 비해 유의적으로 감소하였으며 이러한 효과는 혈액과 간에서 모두 나타났다. 적혈구 항산화 효소인 SOD, GSH-Px glutathione peroxidase 활성도는 대조군, 당뇨군, 자화수군 간에 차이를 보이지 않았고, 혈장 총항산화능인 TRAP 수준도 자화수 섭취로 인한 차이를 볼 수 없었다. 결론적으로 자화수 투여가 db/db mouse를 사용한 제2형 당뇨의 혈당 강하를 포함한 glycemic control에 유리한 개선효과를 보일 뿐 아니라 혈액과 간의 DNA 손상 감소효과까지 보임을 확인하였다. 그러나 그 기전에 대해서는 확실하게 규명하지 못하였으므로 앞으로 자화 수음용 효과를 뒷받침할 더욱 깊고 다양한 기전 연구가 수행되어야 할 것이다.