47 research outputs found

    Idiopathic club foot treated with the Ponseti method. Clinical and sonographic evaluation of Achilles tendon tenotomy. A review of 221 club feet

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    SummaryThe Ponseti method applied to treating idiopathic club foot consists in placing successive corrective casts, possibly an Achilles tendon tenotomy, then derotation braces, a method that has proven its efficacy. This study compared 221 cases of club foot treated with this method between 2002 and 2007 divided into two groups, based on whether or not Achilles tendon tenotomy was performed. Assessment was both clinical and sonographic. We observed clear improvement of the results in the group that underwent Achilles tendon tenotomy and a significant difference in the rate of secondary surgery. The sonographic evaluation also showed improvement of the morphological results. We now systematically propose Achilles tendon tenotomy however severe club foot may be

    Timescales of chemical equilibrium between the convecting solid mantle and over- and underlying magma oceans

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    After accretion and formation, terrestrial planets go through at least one magma ocean episode. As the magma ocean crystallises, it creates the first layer of solid rocky mantle. Two different scenarios of magma ocean crystallisation involve that the solid mantle either (1) first appears at the core–mantle boundary and grows upwards or (2) appears at mid-mantle depth and grows in both directions. Regardless of the magma ocean freezing scenario, the composition of the solid mantle and liquid reservoirs continuously change due to fractional crystallisation. This chemical fractionation has important implications for the long-term thermo-chemical evolution of the mantle as well as its present-day dynamics and composition. In this work, we use numerical models to study convection in a solid mantle bounded at one or both boundaries by magma ocean(s) and, in particular, the related consequences for large-scale chemical fractionation. We use a parameterisation of fractional crystallisation of the magma ocean(s) and (re)melting of solid material at the interface between these reservoirs. When these crystallisation and remelting processes are taken into account, convection in the solid mantle occurs readily and is dominated by large wavelengths. Related material transfer across the mantle–magma ocean boundaries promotes chemical equilibrium and prevents extreme enrichment of the last-stage magma ocean (as would otherwise occur due to pure fractional crystallisation). The timescale of equilibration depends on the convective vigour of mantle convection and on the efficiency of material transfer between the solid mantle and magma ocean(s). For Earth, this timescale is comparable to that of magma ocean crystallisation suggested in previous studies (Lebrun et al., 2013), which may explain why the Earth's mantle is rather homogeneous in composition, as supported by geophysical constraints

    From working in the wheat field to managing wheat: women innovators in Nepal

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    This article presents research conducted in Nepal’s Terai plains in 2014-15 showing that women are innovating in wheat to the extent that wheat farming is experiencing a shift from feminization of agricultural labor towards women taking control over decision making. Processes accounting for this include male out-migration, non-governmental organizations working on promoting women’s equality that has developed women’s confidence, individual support from extension agents, and strong cooperation between women to foster each other’s “innovation journeys.

    ВАКУУМНАЯ ЛИНЕЙНАЯ УСТАНОВКА ДЛЯ НАНЕСЕНИЯ ГИДРОФОБНОГО ПРОСВЕТЛЯЮЩЕГО ПОКРЫТИЯ НА СЕНСОРНЫЕ ДИСПЛЕИ

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    The aim of the work is to develop vacuum technological equipment for deposition an interference antireflection coating with the evaporation of a hydrophobic protective layer in a single vacuum cycle. To deposition an interference antireflection coating, the method of magnetron reactive sputtering in the alternating current mode with a frequency of 20 kHz is used. This method allows using of a wide range of sputtered materials and obtains stable and high-quality coatings on various substrates. To determine the optical characteristics, a spectrophotometer was used, which evaluated the transmittance and reflection in the visible region of the spectrum of electromagnetic radiation. To check the physical characteristics of the hydrophobic coating, abrasion test of the coating with metal wool with a load of 1 kg/cm2 was used. The novelty of the presented method is the combination of the liquid-phase coating method together with physical deposition in a vacuum without interrupting the process. This method allows increasing productivity and yield of suitable parts since the number of operations at the multi-stage stage of production of the touch display is reduced. After the development and adjustment of the Aurora G5 linear vacuum equipment, a stable and reproducible process for producing hydrophobic anti-reflective coatings over large areas with high performance was obtained. An antireflection coating was obtained with an average reflection coefficient of less than 0.6 % in the wavelength range of 400 to 700 nm. The adhesion test showed grade 0 according to the ISO classification. The resulting coatings have high hardness >9 H and abrasion resistance >5000 cycles. The result of this development and research is the introduction of vacuum processing equipment in the manufacturing process for the manufacture of anti-reflective hydrophobic coatings on touch displays.Целью работы является разработка вакуумного технологического оборудования для напыления интерференционного просветляющего покрытия с последующим нанесением гидрофобного защитного слоя в едином вакуумном цикле. Для напыления интерференционного просветляющего покрытия используется метод магнетронного реактивного распыления в режиме переменного тока с частотой 20 кГц. Данный метод позволяет использовать широкий спектр распыляемых материалов и получать стабильные и качественные покрытия на различных подложках. Для определения оптических характеристик использовали спектрофотометр, которым оценивали коэффициенты пропускания и отражения в видимой области спектра электромагнитного излучения. Для проверки физических характеристик гидрофобного покрытия использовали тест на истирание покрытия металлической ватой с нагрузкой 1 кг/см2. Новизной представленного метода является совмещение жидкофазного метода нанесения покрытий совместно с физическим распылением в вакууме без разрыва технологического процесса. Данный метод позволяет добиться увеличения производительности и выхода годных деталей, так как уменьшается количество операций на многоступенчатом этапе производства сенсорного дисплея. После разработки и настройки линейного вакуумного оборудования Aurora G5 был получен стабильный и воспроизводимый технологический процесс получения гидрофобных просветляющих покрытий на большие площади с высокой производительностью. Получено просветляющее покрытие со средним коэффициентом отражения менее 0,6 % в диапазоне длин волн 400 до 700 нм. Проверка адгезии показала 0 класс согласно классификации ISO. Полученные покрытия имеют высокие твердость >9H и стойкость к истиранию >5000 циклов. Итогом данной разработки и исследования является внедрение вакуумного технологического оборудования в производственный процесс изготовления просветляющих гидрофобных покрытий на сенсорные дисплеи

    In-line sputtering coater of hydrophobic antireflection coating for sensor display

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    Целью работы является разработка вакуумного технологического оборудования для напыления интерференционного просветляющего покрытия с последующим нанесением гидрофобного защитного слоя в едином вакуумном цикле. Для напыления интерференционного просветляющего покрытия используется метод магнетронного реактивного распыления в режиме переменного тока с частотой 20 кГц. Данный метод позволяет использовать широкий спектр распыляемых материалов и получать стабильные и качественные покрытия на различных подложках. Для определения оптических характеристик использовали спектрофотометр, которым оценивали коэффициенты пропускания и отражения в видимой области спектра электромагнитного излучения. Для проверки физических характеристик гидрофобного покрытия использовали тест на истирание покрытия металлической ватой с нагрузкой 1 кг/см2. Новизной представленного метода является совмещение жидкофазного метода нанесения покрытий совместно с физическим распылением в вакууме без разрыва технологического процесса. Данный метод позволяет добиться увеличения производительности и выхода годных деталей, так как уменьшается количество операций на многоступенчатом этапе производства сенсорного дисплея. После разработки и настройки линейного вакуумного оборудования Aurora G5 был получен стабильный и воспроизводимый технологический процесс получения гидрофобных просветляющих покрытий на большие площади с высокой производительностью. Получено просветляющее покрытие со средним коэффициентом отражения менее 0,6 % в диапазоне длин волн 400 до 700 нм. Проверка адгезии показала 0 класс согласно классификации ISO. Полученные покрытия имеют высокие твердость >9H и стойкость к истиранию >5000 циклов. Итогом данной разработки и исследования является внедрение вакуумного технологического оборудования в производственный процесс изготовления просветляющих гидрофобных покрытий на сенсорные дисплеи

    Properties of Nitrogen/Silicon Doped Vertically Oriented Graphene Produced by ICP CVD Roll-to-Roll Technology

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    Simultaneous mass production of high quality vertically oriented graphene nanostructures and doping them by using an inductively coupled plasma chemical vapor deposition (ICP CVD) is a technological problem because little is understood about their growth mechanism over enlarged surfaces. We introduce a new method that combines the ICP CVD with roll-to-roll technology to enable the in-situ preparation of vertically oriented graphene by using propane as a precursor gas and nitrogen or silicon as dopants. This new technology enables preparation of vertically oriented graphene with distinct morphology and composition on a moving copper foil substrate at a lower cost. The technological parameters such as deposition time (1–30 min), gas partial pressure, composition of the gas mixture (propane, argon, nitrogen or silane), heating treatment (1–60 min) and temperature (350–500 °C) were varied to reveal the nanostructure growth, the evolution of its morphology and heteroatom’s intercalation by nitrogen or silicon. Unique nanostructures were examined by FE-SEM microscopy, Raman spectroscopy and energy dispersive X-Ray scattering techniques. The undoped and nitrogen- or silicon-doped nanostructures can be prepared with the full area coverage of the copper substrate on industrially manufactured surface defects. Longer deposition time (30 min, 450 °C) causes carbon amorphization and an increased fraction of sp3-hybridized carbon, leading to enlargement of vertically oriented carbonaceous nanostructures and growth of pillars

    Vertically oriented graphene based walls and columns obtained by ICP CVD method on moving substrates as prior stage of the roll-to-roll technology

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    Superior optoelectronic properties of graphene have made this material as a special applicant in displays, touch and graphene-based screens with smaller and long-lasting batteries including the field of mobile telephony. Recently we have introduced the process for the formation of vertically oriented graphene (VOG) walls with a curved morphology by ICP CVD method. Such VOG walls represent a very promising material for different applications (e.g. miniature batteries and other optoelectronic devices) due to its unique orientation and open carbon network structure. For the first time such VOG walls have been grown directly on a moving substrate that is a prerequisite for its production by the roll-to-roll technology providing higher yield of the production process at lower cost of the product

    Growing primordial continental crust self-consistently in global mantle convection models

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    The majority of continental crust formed during the hotter Archean was composed of Tonalite-Trondhjemite-Granodiorite (TTG) rocks. In contrast to the present-day loci of crust formation around subduction zones and intra-plate tectonic settings, TTGs are formed when hydrated basalt melts at garnet-amphibolite, granulite or eclogite facies conditions. Generating continental crust requires a two step differentiation process. Basaltic magma is extracted from the pyrolytic mantle, is hydrated, and then partially melts to form continental crust. Here, we parameterise the melt production and melt extraction processes and show self-consistent generation of primordial continental crust using evolutionary thermochemical mantle convection models. To study the growth of TTG and the geodynamic regime of early Earth, we systematically vary the ratio of intrusive (plutonic) and eruptive (volcanic) magmatism, initial core temperature, and internal friction coefficient. As the amount of TTG that can be extracted from the basalt (or basalt-to-TTG production efficiency) is not known, we also test two different values in our simulations, thereby limiting TTG mass to 10% or 50% of basalt mass. For simulations with lower basalt-to-TTG production efficiency, the volume of TTG crust produced is in agreement with net crustal growth models but overall crustal (basaltic and TTG) composition stays more mafic than expected from geochemical data. With higher production efficiency, abundant TTG crust is produced, with a production rate far exceeding typical net crustal growth models but the felsic to mafic crustal ratio follows the expected trend. These modelling results indicate that (i) early Earth exhibited a “plutonic squishy lid” or vertical-tectonics geodynamic regime, (ii) present-day slab-driven subduction was not necessary for the production of early continental crust, and (iii) the Archean Earth was dominated by intrusive magmatism as opposed to “heat-pipe” eruptive magmatism
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