Characterisation and modelling of water wicking and evaporation in capillary porous media for passive and energy-efficient applications

Passive devices based on water wicking and evaporation offer a robust, cheap, off-grid, energy-efficient and sustainable alternative to a wide variety of applications, ranging from personal thermal management to water treatment, from filtration to sustainable cooling technologies. Among the available, highly-engineered materials currently employed for these purposes, polyethylene-based fabrics offer a promising alternative thanks to the precise control of their fabrication parameters, their light-weight, thermal and mechanical properties, chemical stability and sustainability. As such, both woven and non-woven fabrics are commonly used in capillary-fed devices, and their wicking properties have been extensively modelled relying on analytical equations. However, a comprehensive and flexible modelling framework able to investigate and couple all the heat and mass transfer phenomena regulating the water dynamics in complex 2-D and 3-D porous components is currently missing. This work presents a comprehensive theoretical model aimed to investigate the wetting and drying performance of hydrophilic porous materials depending on their structural properties and on the external environmental conditions. The model is first validated against experiments (R2=0.99 for the wicking model; errors lower than 14% and 1% for the evaporation and radiative models, respectively), then employed in three application cases: the characterisation of the capillary properties of a novel textile; the assessment of the thermal performance of a known material for personal thermal management when used in different conditions; the model-assisted design of a porous hydrophilic component of passive devices for water desalination. The obtained results showed a deep interconnection between the different heat and mass transfer mechanisms, the porous structure and external working conditions. Thus, modelling their non-linear behaviour plays a crucial role in determining the optimal material characteristics to maximise the performance of porous materials for passive devices for the energy and water sector

Electrically tunable near-field radiative heat transfer via ferroelectric materials

We explore ways to actively control near-field radiative heat transfer between two surfaces that relies on electrical tuning of phonon modes of ferroelectric materials. Ferroelectrics are widely used for tunable electrical devices, such as capacitors and memory devices; however, their tunable properties have not yet been examined for heat transfer applications. We show via simulations that radiative heat transfer between two ferroelectric materials can be enhanced by over two orders of magnitude over the blackbody limit in the near field, and can be tuned as much as 16.5% by modulating the coupling between surface phonon polariton modes at the two surfaces via varying external electric fields. We then discuss how to maximize the modulation contrast for tunable thermal devices using the studied mechanism.United States. Dept. of Energy. Office of Basic Energy Sciences (DE-FG02-02ER45977

Sustainable polyethylene fabrics with engineered moisture transport for passive cooling

Polyethylene (PE) has emerged recently as a promising polymer for incorporation in wearable textiles owing to its high infrared transparency and tuneable visible opacity, which allows the human body to cool via thermal radiation, potentially saving energy on building refrigeration. Here, we show that single-material PE fabrics may offer a sustainable, high-performance alternative to conventional textiles, extending beyond radiative cooling. PE fabrics exhibit ultra-light weight, low material cost and recyclability. Industrial materials sustainability (Higg) index calculations predict a low environmental footprint for PE fabrics in the production phase. We engineered PE fibres, yarns and fabrics to achieve efficient water wicking and fast-drying performance which, combined with their excellent stain resistance, offer promise in reducing energy and water consumption as well as the environmental footprint of PE textiles in their use phase. Unlike previously explored nanoporous PE materials, the high-performance PE fabrics in this study are made from fibres melt spun and woven on standard equipment used by the textile industry worldwide and do not require any chemical coatings. We further demonstrate that these PE fibres can be dry coloured during fabrication, resulting in dramatic water savings without masking the PE molecular fingerprints scanned during the automated recycling process

Quasicrystals: Making invisible materials

All-dielectric photonic quasicrystals may act as zero-refractive-index homogeneous materials despite their lack of translational symmetry and periodicity, stretching wavelengths to infinity and offering applications in light wavefront sculpting and optical cloaking.Comment: 5 pages, 2 figure

Sustainable polyethylene fabrics with engineered moisture transport for passive cooling

Polyethylene (PE) has emerged recently as a promising polymer for incorporation in wearable textiles owing to its high infrared transparency and tuneable visible opacity, which allows the human body to cool via thermal radiation, potentially saving energy on building refrigeration. Here, we show that single-material PE fabrics may offer a sustainable, high-performance alternative to conventional textiles, extending beyond radiative cooling. PE fabrics exhibit ultra-light weight, low material cost and recyclability. Industrial materials sustainability (Higg) index calculations predict a low environmental footprint for PE fabrics in the production phase. We engineered PE fibres, yarns and fabrics to achieve efficient water wicking and fast-drying performance which, combined with their excellent stain resistance, offer promise in reducing energy and water consumption as well as the environmental footprint of PE textiles in their use phase. Unlike previously explored nanoporous PE materials, the high-performance PE fabrics in this study are made from fibres melt spun and woven on standard equipment used by the textile industry worldwide and do not require any chemical coatings. We further demonstrate that these PE fibres can be dry coloured during fabrication, resulting in dramatic water savings without masking the PE molecular fingerprints scanned during the automated recycling process.The textile industry is one of the largest polluters. Here the authors show that polyethylene is a sustainable alternative textile with water wicking and fast-drying performance. The fabrication of polyethylene fabrics is compatible with standard equipment and could be dry-coloured, further reducing water consumption

Стволовой энцефалит Бикерстаффа, острый поперечный миелит и острая моторная аксональная нейропатия: сложности диагностики и лечения пациентов с перекрестными синдромами. Клиническое наблюдение

We report a 40-year-old woman presented with consciousness disturbance, ataxia, asymmetrical limb weakness, hyperreflexia. Due to magnetic resonance imaging findings, the patient was diagnosed with Bickerstaff’s brainstem encephalitis overlapped with acute transverse myelitis. Later she developed distal muscles atrophy and the electroneuromyographic study revealed axonal motor neuropathy, therefore acute motor axonal neuropathy was diagnosed. The patient underwent one course of intravenous immunoglobulin therapy with the regression of symptoms and magnetic resonance imaging changes. Nine months after symptoms onset, the patient has completely recovered. This overlapping case of Bickerstaff’s brainstem encephalitis, acute transverse myelitis and acute motor axonal neuropathy provides further support that these conditions are part of the same spectrum. Представлено клиническое наблюдение пациентки 40 лет с нарушением сознания, атаксией, асимметричным нижним парапа- резом, гиперрефлексией. В связи с обнаружением по данным магнитно-резонансной томографии изменений головного и спинного мозга был поставлен диагноз стволового энцефалита Бикерстаффа и острого поперечного миелита. Позднее ввиду развившейся атрофии дистальных мышц верхних и нижних конечностей было проведено электронейромиографическое исследование, выявившее изолированное поражение моторных волокон и подтвердившее присоединение острой моторной аксональной нейропатии. Однократный курс внутривенного иммуноглобулина дал положительный эффект c регрессом симптомов и очаговых изменений при повторном магнитно-резонансном исcледовании. Через 9 мес от дебюта болезни отмечено полное восстановление неврологического дефицита. Таким образом, был поставлен диагноз перекрестного синдрома стволового энцефалита Бикерстаффа, острого поперечного миелита и острой моторной аксональной нейропатии. Описанный случай может служить дополнительным подтверждением патогенетического сходства этих состояний.

Corpus Based Approaches to Figurative Language

Since the inception of the biennial Corpus Linguistics Conferences in 2001, we have held an accompanying work-shop/colloquium on Corpus-Based Approaches to Figurative Language, with the exception of 2007. We are continuing the tradition in 2009 with the 5th Corpus Linguistics Conference at the University of Liverpool, UK, 20th-23rd July. The theme of the colloquium this year is variation and variability in metaphor. This is a broad topic that is intended to encompass matters such as, but not limited to: variation in particular types of metaphor, such as temporal metaphors, across different genres such as news items or personal blogs; degrees of entrenchment or conventionality in metaphor, again possibly across different genres/registers; the nature of mixed metaphors; and how to use corpora to get at such types of information. The colloquium was also open to contributions examining any aspect of figurative language from a corpus-based perspective, since we believe that, for example, participants who have undertaken good corpus-based studies of a particular topic, but who have used only a single genre or corpus, may find fruitful interaction with other participants who have investigated similar topics but used different genres. Such interaction is by itself an important contribution to the theme of variety and variability