• Title/Summary/Keyword: Centre of pressure

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Synthesis and Biological Activities of New Substituted Indoles

  • Hishmat, Orchidee H.;Nakkady, Sally S.;El Shabrawy, Osama A.;Mahmoud, Sawsan S.
    • Archives of Pharmacal Research
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    • v.15 no.1
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    • pp.104-108
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    • 1992
  • 2, 3-Diphenyl-6-formyl-5-methoxyindole reacts with ethyl cyano acetate to yield the arylidene derivative which forms with urea and thiourea the corresponding pyrimidine derivatives. The arylidene derivatives react with hydrazines and with active methylenes to form the respective pyrazole derivatives and the $\alpha, \;\beta$-disubstituted acrylonitriles. Seven new compounds were tested for their effects on the arterial blood pressure of rats and analgesic activity.

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Process Modeling and Optimization Studies in Drying of Current Transformers

  • Bhattacharya, Subhendu;D'Melo, Dawid;Chaudhari, Lokesh;Sharma, Ram Avatar;Swain, Sarojini
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.6
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    • pp.273-277
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    • 2012
  • The vacuum drying process for drying of paper in current transformers was modeled with an aim to develop an understanding of the drying mechanism involved and also to predict the water collection rates. A molecular as well as macroscopic approach was adopted for the prediction of drying rate. Ficks law of diffusion was adopted for the prediction of drying rates at macroscopic levels. A steady state and dynamic mass transfer simulation was performed. The bulk diffusion coefficient was calculated using weight loss experiments. The accuracy of the solution was a strong function of the relation developed to determine the equilibrium moisture content. The actually observed diffusion constant was also important to predict the plant water removal rate. Thermo gravimetric studies helped in calculating the diffusion constant. In addition, simulation studies revealed the formation of perpetual moisture traps (loops) inside the CT. These loops can only be broken by changing the temperature or pressure of the system. The change in temperature or pressure changes the kinetic or potential energy of the effusing vapor resulting in breaking of the loop. The cycle was developed based on this mechanism. Additionally, simulation studies also revealed that the actual mechanism of moisture diffusion in CT's is by surface jumps initiated by surface diffusion balanced against the surrounding pressure. Every subsequent step in the cycle was to break such loops. The effect of change in drying time on the electrical properties of the insulation was also assessed. The measurement of capacitance at the rated voltage and one third of the rated voltage demonstrated that the capacitance change is within the acceptance limit. Hence, the new cycle does not affect the electrical performance of the CT.

Consideration for the development of room-temperature ambient-pressure superconductor (LK-99) (상온상압 초전도체(LK-99) 개발을 위한 고찰)

  • Sukbae Lee;Jihoon Kim;Sungyeon Im;SooMin An;Young-Wan Kwon;Keun Ho Auh
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.33 no.2
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    • pp.61-70
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    • 2023
  • This paper examines the way of thinking and limitations of physicists regarding the phenomenon of superconductivity and outlines how room-temperature and ambient-pressure superconductors can be developed through the statistical thermodynamic background of the liquid state theory. In hypothesis, the number of electron states should be limited by confining them to a state close to one-Dimension. Simultaneously, the electron-electron interactions should be frequent enough for the electrons to have liquid-like properties. As an example of implementing the hypothesis, our team reports the development of room-temperature and ambient-pressure superconductivity of a material named LK-99 (superconducting compound name developed in the research), whose structure was revealed through numerous experiments with a clue found by chance. Moreover, we summarize the theoretical and experimental basis for the characteristics and discovery of the world's first superconducting material surpassing the critical temperature of 97℃ at atmospheric pressure.

Advances in the understanding of molybdenum effect on iodine and caesium reactivity in condensed phase in the primary circuit in nuclear severe accident conditions

  • Gouello, Melany;Hokkinen, Jouni;Karkela, Teemu
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1638-1649
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    • 2020
  • In the case of a severe accident in a Light Water Reactor, the issue of late release of fission products, from the primary circuit surfaces is of particular concern due to the direct impact on the source term. CsI is the main iodine compound present in the primary circuit and can be deposited as particles or condensed species. Its chemistry can be affected by the presence of molybdenum, and can lead to the formation of gaseous iodine. The present work studied chemical reactions on the surfaces involving gaseous iodine release. CsI and MoO3 were used to highlight the effects of carrier gas composition and oxygen partial pressure on the reactions. The results revealed a noticeable effect of the presence of molybdenum on the formation of gaseous iodine, mainly identified as molecular iodine. In addition, the oxygen partial pressure prevailing in the studied conditions was an influential parameter in the reaction.

Flow-induced interior noise from a turbulent boundary layer of a towed body

  • Abshagen, J.;Kuter, D.;Nejedl, V.
    • Advances in aircraft and spacecraft science
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    • v.3 no.3
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    • pp.259-269
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    • 2016
  • In this work results from an underwater experiment on flow-induced noise in the interior of a towed body generated from a surrounding turbulent boundary layer are presented. The measurements were performed with a towed body under open sea conditions at towing depths below 100 m and towing speeds ranging from 2.4 m/s to 6.2 m/s (4 kn to 12 kn). Focus is given in the experiments to the relation between (outer) wall pressure fluctuations and the (inner) hydroacoustic near-field on the reverse side of a flat plate. The plate configuration consists of a sandwich structure with an (thick) outer polyurethane layer supported by an inner thin layer from fibre-reinforced plastics. Parameters of the turbulent boundary layer are estimated in order to analyse scaling relations of wall-pressure fluctuations, interior hydroacoustic noise, and the reduction of pressure fluctuations through the plate.

Removal of BP-3 Endocrine Disrupting Chemical (EDC) using cellulose acetate and ZnOnano particles mixed matrix membranes

  • Rajesha, B.J.;Chandan, H.R.;Sunil, K.;Padaki, Mahesh;Balakrishna, Geetha R.
    • Membrane and Water Treatment
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    • v.7 no.6
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    • pp.507-520
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    • 2016
  • The effect of ZnO on cellulose acetate in the removal of benzophenone-3 (BP-3) was investigated. The benzophenone-3 (BP-3) which is an endocrine disrupting chemical (EDC) was completely removed (100%) from the drinking water using Cellulose Acetate (CA) and zinc oxide (ZnO) composite membranes. The membranes were prepared by DIPS method and the filtration experiments were conducted by dead end filtration unit. The macrostructure of the membrane were studied by ATR-IR and XRD Spectra's. Atomic force microscopy (AFM) and Scanning electron microscopy (SEM) were used to study the micro properties of the membranes. The laboratory experiments such as water uptake study and pure water flux performed to confirm the increasing hydrophilicity. The enhancing hydrophilicity was confirmed with respect to higher the concentration of nanoparticles. Evaluation of BP-3 removal was carried in different experimental conditions, such as, different Trans membrane pressure and different concentration of feed. The membrane with low pressure showed better performance by rejecting 100% of BP-3. However, 1 ppm, 3 ppm and 6 ppm of feed solution was used and among them 3 ppm of feed solution gives 100% rejection. The ZnO nanoparticales enhances the performance of CA membrane by showing maximum rejection.

In-shoe Loads during Treadmill Running (트레드밀 달리기시 신발 내부의 부하에 관한 연구)

  • Lee, Ki-Kwang
    • Korean Journal of Applied Biomechanics
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    • v.14 no.2
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    • pp.105-119
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    • 2004
  • To enhance our understanding of the loads on the foot during treadmill running, we have used a pressure-sensitive insole system to determine pressure, rate of loading and impulse distributions on the plantar surface during treadmill running, both in minimally cushioned footwear and in cushioned shoes. This report includes pressure, rate of loading, impulse and contact time data from a study of ten subjects running on a treadmill at 4.0m/s. Among heel-toe runners, the highest peak pressures and highest rates of loading were observed under the centre of the heel and in the medial forefoot. The arch regions were only lightly loaded. Contact time was greater in the forefoot than in the heel. Two-thirds of the impulse recorded during the step was the result of forces applied through the forefoot, mostly in the region of the metatarsal heads. The distribution of loads in the shoe suggests that the load distributing properties of the cushioning system are most important in the centre of the heel, under the metatarsal heads and great toe. Shock attenuation is primarily required under the centre of the heel and to lesser extent under the metatarsal heads. Some energy dissipation may be desirable in the heel region because it causes shock to be absorbed with less force. All the 'propulsive' effort is applied through the forefoot. Therefore, this region should as resilient as possible.