Search results for: dissipative anchoring

Authors: Woo-tai Jung, Jong-sup Park, Jae-yoon Kang, Moon-seoung Keum

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CFRP (Carbon Fiber Reinforced Polymer) is mainly used as reinforcing material for degraded structures owing to its advantages including its non-corrodibility, high strength, and lightweight properties. Recently, dedicated studies focused not only on its simple bonding but also on its tensioning. The tension necessary for prestressing requires the anchoring of multi-CFRP tendons with high capacity and the surface treatment of the CFRP tendons may also constitute an important issue according to the type of anchor. The wedge type, swage type or bonded type anchor can be used to anchor the CFRP tendon. The bonded type anchor presents the disadvantage to lengthen the length of the anchor due to the low bond strength of the CFRP tendon without surface treatment. This study intends to overcome this drawback through the application of a method enlarging the bond area at the end of the CFRP tendon. This method enlarges the bond area by splitting the end of the CFRP tendon along its length and can be applied when CFRP is produced by pultrusion. The application of this method shows that the mono-CFRP tendon and 3-multi CFRP tendon secured the anchor performance corresponding to the tensile performance of the CFRP tendon and that the 7-multi tendon secured anchor performance corresponding to 90% of the tensile strength due to the occurrence of buckling in the steel tube anchorage.

Keywords: carbon fiber reinforced polymer (CFRP), tendon, anchor, tensile property, bond strength

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Authors: Meiyun Meng

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Urban China is now undergoing social transformation based on its rapid economic growth, developing its individualism and feminism. This paper approaches emergent relationships between female individuals’ everyday lives and urban China through internal migration, home-making practices and life-course perspectives. Focusing on Shenzhen, it explores how ten highly educated female migrants pursue aspirations of accommodating ‘non-majority’ identities, such as lesbians, divorced, or childless women, in urban China. Based on life stories and home video tours, this paper finds how these women develop non-majority lifestyles to negotiate their aspirations. On the one hand, they ‘sail’ away from past/present situations where collectivist and hetero-patriarchal norms marginalised their non-majority identities. On the other hand, they ‘anchor’ in places where ‘new’ socio-cultural contexts allow female individuals to pursue alternative opportunities and preferential lifestyles. This paper provides fresh insights to interpret the social transformation in urban China, under the collectivist culture and hetero-patriarchal norms, through the lens of individual everyday home-making practices.

Keywords: home-making practices, internal migration, highly educated women, shenzhen, transforming urban China

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Authors: Mafalda Fabiene Ferreira Pantoja, Joao Da Costa Pantoja, Rui Humberto Costa De Fernandes Povoas

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The present paper seeks to present a theoretical and practical reflection about examples of contemporary architecture in the world context where concerns about the planet become prominent and increasingly necessary. Firstly, a brief introduction will be made on the conceptual principles of tectonics in architecture in order to apply such concepts in a perspective of analysis of the intersection between design and construction in contemporary examples of Norman Foster’s architecture, once his work has demonstrated attitudes of composition that concerns about the place, technology, materials, and building life. Foster's compositions are usually focused on the role of technology in the process of architectural design, making his works a mixture of place, program, construction, and formal structures. The main purpose of the present paper is the reflection on the tools of theoretical and practical analysis about tectonics, optimizing the resources that allow cultural anchoring and creation of identity. Also establishing relation between resources, building life cycle and employment of correct materials, in order to find out how the tectonic concept can elevate the status of contemporary architecture, making it qualitative in a more sustainable context and adapted to current needs.

Keywords: contemporary architecture, norman foster, tectonic, sustainable architecture

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Authors: Peikun Zhang, Chunhua Cui

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Photoelectrochemical (PEC) water splitting provides a promising pathway to convert solar energy into renewable fuels. However, the main and seemingly insurmountable obstacle is that the sluggish kinetics of oxygen evolution reaction (OER) severely jeopardizes the overall efficiency, thus exploring highly active, stable, and appreciable catalysts is urgently requested. Herein a competitive coordination strategy was demonstrated to form a reversible hybrid homo-heterogeneous catalyst for efficient OER in alkaline media. The dynamic process involves an in-situ anchoring of soluble nickel–bipyridine pre-catalyst to a conductive substrate under OER and a re-dissolution course under open circuit potential, induced by the competitive coordination between nickel–bipyridine and nickel-hydroxyls. This catalyst allows to elaborately self-modulate a charge-transfer layer thickness upon the catalytic on-off operation, which affords substantially increased active sites, yet remains light transparency, and sustains the stability of over 200 hours of continuous operation. The integration of this catalyst with exemplified state-of-the-art Ni-sputtered Si photoanode can facilitate a ~250 mV cathodic shift at a current density of 20 mA cm-2. This finding helps the understanding of catalyst from a “dynamic” perspective, which represents a viable alternative to address remaining hurdles toward solar-driven water oxidation.

Keywords: molecular catalyst, oxygen evolution reaction, solar energy, transition metal complex, water splitting

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Authors: Grace Anweh, Patience Achakpa-ikyo

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The issue of women unfavourable representation in the mass media is long standing. While it is a worldwide problem, developing countries in Africa especially Nigeria are considered peculiar. This paper, ‘mass media representation and the status of women in the 2015, general elections in Nigeria’ therefore aimed to assess the current trend of role playing in the mass media and how this has affected general status of women in Nigeria politics with particular reference to the 2015 general elections. The study employed a review of secondary literature and data regarding previous performances of Nigeria women in politics from 1999 to 2015 and the picture that has been paid by Nigerian mass media about women. Anchoring the paper on the agenda setting theory of the mass media, the paper analysed secondary literature and discovered that from 1999 to date, women have been participating in politics but rather than improve their status in elective offices, the percentage of women for such offices is rather declining. This trend the paper concluded is attributed to the way and manner women are represented in the mass media - as not good for policy making offices except as kitchen and home managers. The paper therefore recommends that, the country should adopt the quota allocation for all the political parties in order to give women a chance to compete with their male counterparts. While women should strive towards the managerial and ownership of media houses in order to represent the interest of women in politics thus offering the opportunity for the favourable representation of women and role models for those who may want to tour a similar part.

Keywords: mass media, media representation, Nigeria elections, women

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Authors: Lee Waters, Itay Basevitch, Matthew Timmis

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Objectives: Eye tracking technology is a valuable method of assessing individuals gaze behaviour, but it does not unveil why they are engaging in certain practices. To address limitations in sport eye tracking research the present paper aims to investigate the gaze behaviours soccer officials engage in during successful and unsuccessful offside decisions, but also why. Methods: 20 male active amateur qualified (Level 4-7) soccer officials (Mage 22.5 SD 4.61 yrs) with an average experience of 41-50 games wore eye tracking technology during an applied attack versus defence drill. While reviewing the eye tracking footage, retrospective semi-structured interviews were conducted (M=20.4 min; SD=6.2; Range 11.7 – 26.8 min) and once transcribed inductive thematic analysis was performed. Findings and Discussion: To improve the understanding of gaze behaviours and how officials make sense of the environment, during the interview’s key constructs of offside, decision making, obstacles and emotions were summarised as the higher order themes while making offside decisions. Gaze anchoring was highlighted to be a successful technique to allow officials to see all relevant information, whereas the type of offside was emphasised to be a key factor in correct interpretation. Furthermore, specific decision-making training was outlined to be inconsistent and not always applicable. Conclusions: Key constructs have been identified and explained, which can be shared with soccer officials through training regimes. Eye tracking technology has also been shown to be a useful and innovative reflective tool to assist in the understanding of individuals gaze behaviours.

Keywords: eye tracking, gaze behvaiour, decision making, reflection

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Authors: Dhruv Mehta, Alexander van Zuijlen, Hester Bijl

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Large Eddy Simulation (LES) numerically resolves the large energy-containing eddies of a turbulent flow, while modelling the small dissipative eddies. On a wind farm, these large scales carry the energy wind turbines extracts and are also responsible for transporting the turbines’ wakes, which may interact with downstream turbines and certainly with the atmospheric boundary layer (ABL). In this situation, it is important to conserve the energy that these wake’s carry and which could be altered artificially through numerical dissipation brought about by the schemes used for the spatial discretisation and temporal integration. Numerical dissipation has been reported to cause the premature recovery of turbine wakes, leading to an over prediction in the power produced by wind farms.An energy-conserving scheme is free from numerical dissipation and ensures that the energy of the wakes is increased or decreased only by the action of molecular viscosity or the action of wind turbines (body forces). The aim is to create an LES package with energy-conserving schemes to simulate wind turbine wakes correctly to gain insight into power-production, wake meandering etc. Such knowledge will be useful in designing more efficient wind farms with minimal wake interaction, which if unchecked could lead to major losses in energy production per unit area of the wind farm. For their research, the authors intend to use the Energy-Conserving Navier-Stokes code developed by the Energy Research Centre of the Netherlands.

Keywords: energy-conserving schemes, modelling turbulence, Large Eddy Simulation, atmospheric boundary layer

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Authors: Claudius Peter Van Wyk

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Given the increasingly manifest phenomena, as described in complexity theory, of volatility, uncertainty, complexity and ambiguity (VUCA), Taleb's notion of 'antifragility, has a significant contribution to make to positive psychology applied to wellbeing. Antifragility is argued to be fundamentally different from the concepts of resiliency; as the ability to recover from failure, and robustness; as the ability to resist failure. Rather it describes the capacity to reorganise in the face of stress in such a way as to cope more effectively with systemic challenges. The concept, which has been applied in disciplines ranging from physics, molecular biology, planning, engineering, and computer science, can now be considered for its application in individual human and social wellbeing. There are strong correlations to Antonovsky's model of 'salutogenesis' in which an attitude and competencies are developed of transforming burdening factors into greater resourcefulness. We demonstrate, from the perspective of neuroscience, how technology measuring nervous system coherence can be coupled to acquired psychodynamic approaches to not only identify contextual stressors, utilise biofeedback instruments for facilitating greater coherence, but apply these insights to specific life stressors that compromise well-being. Employing an on-going case study with BMW South Africa, the neurological mapping is demonstrated together with 'reframing' and emotional anchoring techniques from neurolinguistic programming. The argument is contextualised in the discipline of psychoneuroimmunology which describes the stress pathways from the CNS and endocrine systems and their impact on immune function and the capacity to restore homeostasis.

Keywords: antifragility, complexity, neuroscience, psychoneuroimmunology, salutogenesis, volatility

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Authors: Katsumi Mera

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The purpose of this study was to clarify the relationship between strengths/weaknesses on studying and subjective well-being among Japanese working adults. We conducted an online questionnaire survey of Japanese working adults (aged 20-69) and obtained 1,063 valid responses. Subjective well-being was evaluated using the Cantril Self-Anchoring Striving Scale, the method used in the World Happiness Survey, in which the highest possible life is set at 10, and the lowest possible life is set at 0. The mean subjective well-being of all 1,063 respondents was 5.87, which is a very similar value that was obtained in the Japanese World Happiness Survey in 2023. First, we investigated the respondents' strengths/weaknesses in studying and their subjective well-being. The results showed that the subjective well-being of the group who answered that they were good at studying (6.62) was significantly higher than that of the group who answered that they were poor at studying (5.15). Next, we investigated the subjective well-being of students who answered that they were good at Japanese, Math, English, Social studies, and Science, the major subjects in Japan, and found that the subjective well-being of the group that answered that they were good at these subjects was higher than that of the group that answered that they were poor at these subjects. When the correlation between the score of "strengths/weaknesses on studying" and the score of "subjective well-being" was examined, those who answered that they were good at studying had higher subjective well-being (correlation coefficient r = 0.26, p < 0.001). The correlation between the subjective well-being score and the score of "strengths/weaknesses on studying each subject” was examined. Among the subjects, the subjective well-being score was the highest for those who answered that they were good at English (correlation coefficient r = 0.17, p < 0.001). These results indicate a relationship between strengths/weaknesses on studying and subjective well-being among workers in Japan. These findings may provide an important basis for considering what kind of education should be focused on in order to nurture working adults with high levels of well-being.

Keywords: subject well-being, strengths/weaknesses, studying, Japanese working adults

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Authors: Yanrong Song, Zikai Dong, Runqin Xu, Jinrong Tian, Kexuan Li

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Nonlinear polarization rotation (NPR) technique has become one of the main techniques to achieve mode-locked fiber lasers for its compactness, implementation, and low cost. In this paper, we demonstrate a compact mode-locked Yb-doped fiber laser based on NPR technique in the all normal dispersion (ANDi) regime. In the laser cavity, there are no physical filter and polarization controller in laser cavity. Mode-locked pulse train is achieved in ANDi regime based on NPR technique. The fiber birefringence induced filtering effect is the mainly reason for mode-locking. After that, an extra 20 m long single-mode fiber is inserted in two different positions, dissipative soliton operation and noise like pulse operations are achieved correspondingly. The nonlinear effect is obviously enhanced in the noise like pulse regime and broadband spectrum generated owing to enhanced stimulated Raman scattering effect. When the pump power is 210 mW, the central wavelength is 1030 nm, and the corresponding 1st order Raman scattering stokes wave generates and locates at 1075 nm. When the pump power is 370 mW, the 1st and 2nd order Raman scattering stokes wave generate and locate at 1080 nm, 1126 nm respectively. When the pump power is 600 mW, the Raman continuum is generated with cascaded multi-order stokes waves, and the spectrum extends to 1188 nm. The total flat spectrum is from 1000nm to 1200nm. The maximum output average power and pulse energy are 18.0W and 14.75nJ, respectively.

Keywords: fiber laser, mode-locking, nonlinear polarization rotation, Raman scattering

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Authors: Yingwei Hou, Tao Liu, Yong Pang

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The paper explored the three-dimensional deformation of mussel plaques anchor to wet polydimethylsiloxane (PDMS) substrates under tension stress with different angles. Mussel plaques exhibiting natural adhesive structures, have attracted significant attention for their remarkable adhesion properties. Understanding their behavior under mechanical stress, particularly in a three-dimensional context, holds immense relevance for biomimetic material design and bio-inspired adhesive development. This study employed a novel approach to investigate the 3D deformation of the PDMS substrates anchored by mussel plaques subjected to controlled tension. Utilizing our customized stereo digital image correlation technique and mechanical mechanics analyses, we found the distributions of the displacement and resultant force on the substrate became concentrated under the plaque. Adhesion and sucking mechanisms were analyzed for the mussel plaque-substrate system under tension until detachment. The experimental findings were compared with a developed model using finite element analysis and the results provide new insights into mussels’ attachment mechanism. This research not only contributes to the fundamental understanding of biological adhesion but also holds promising implications for the design of innovative adhesive materials with applications in fields such as medical adhesives, underwater technologies, and industrial bonding. The comprehensive exploration of mussel plaque behavior in three dimensions is important for advancements in biomimicry and materials science, fostering the development of adhesives that emulate nature's efficiency.

Keywords: adhesion mechanism, mytilus edulis, mussel plaque, stereo digital image correlation

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Authors: Samuel Ahamefula Mba

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Fluid turbulence is a complex and nonlinear phenomenon that occurs in various natural and industrial processes. Understanding turbulence remains a challenging task due to its intricate nature. One approach to gain insights into turbulence is through the study of entropy, which quantifies the disorder or randomness of a system. This research presents a numerical investigation of entropy signatures in fluid turbulence. The work is to develop a numerical framework to describe and analyse fluid turbulence in terms of entropy. This decomposes the turbulent flow field into different scales, ranging from large energy-containing eddies to small dissipative structures, thus establishing a correlation between entropy and other turbulence statistics. This entropy-based framework provides a powerful tool for understanding the underlying mechanisms driving turbulence and its impact on various phenomena. This work necessitates the derivation of the Poisson equation for pressure transformation of Navier-Stokes equation and using Chebyshev-Finite Difference techniques to effectively resolve it. To carry out the mathematical analysis, consider bounded domains with smooth solutions and non-periodic boundary conditions. To address this, a hybrid computational approach combining direct numerical simulation (DNS) and Large Eddy Simulation with Wall Models (LES-WM) is utilized to perform extensive simulations of turbulent flows. The potential impact ranges from industrial process optimization and improved prediction of weather patterns.

Keywords: turbulence, Navier-Stokes equation, Poisson pressure equation, numerical investigation, Chebyshev-finite difference, hybrid computational approach, large Eddy simulation with wall models, direct numerical simulation

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Authors: Hoa Thi Hoang, Stephan Sass, Michael U. Kumke

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Concanavalin A (conA) is a protein has been widely used in sensor system based on its specific binding to α-D-Glucose or α-D-Manose. For glucose sensor using conA, either fluoresence based techniques with intensity based or lifetime based are used. In this research, liposomes made from phospholipids were used as a biomimetic membrane system. In a first step, novel building blocks containing perylene labeled glucose units were added to the system and used to decorate the surface of the liposomes. Upon the binding between rhodamine labeled con A to the glucose units at the biomimetic membrane surface, a Förster resonance energy transfer system can be formed which combines unique fluorescence properties of perylene (e.g., high fluorescence quantum yield, no triplet formation) and its high hydrophobicity for efficient anchoring in membranes to form a novel probe for the investigation of sugar-driven binding reactions at biomimetic surfaces. Two glucose-labeled perylene derivatives were synthesized with different spacer length between the perylene and glucose unit in order to probe the binding of conA. The binding interaction was fully characterized by using high-end fluorescence techniques. Steady-state and time-resolved fluorescence techniques (e.g., fluorescence depolarization) in combination with single-molecule fluorescence spectroscopy techniques (fluorescence correlation spectroscopy, FCS) were used to monitor the interaction with conA. Base on the fluorescence depolarization, the rotational correlation times and the alteration in the diffusion coefficient (determined by FCS) the binding of the conA to the liposomes carrying the probe was studied. Moreover, single pair FRET experiments using pulsed interleaved excitation are used to characterize in detail the binding of conA to the liposome on a single molecule level avoiding averaging out effects.

Keywords: concanavalin A, FRET, sensor, biomimetic membrane

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Authors: Kimberly Tasha Jiayi Tang, Changqing Lin, Zhe Wang, Tze-Wai Wong, Md. Shakhaoat Hossain, Jian Yu, Alexis Lau

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Hong Kong has practiced a risk-based Air Quality Health Index (AQHI) system that sums hospitalization risks associated with short-term exposure to air pollu-tants. As an air pollution risk communication tool, it informs the public about the current air quality, anchoring around the World Health Organization's (WHO) 2005 Air Quality Guidelines (AQGs). Given the WHO's recent update in 2021, assessing how Hong Kong’s air quality risk communication can be en-hanced using these updated guidelines is essential. Hong Kong’s AQHI is lim-ited by solely focusing on short-term health risks, which could lead the public to underestimate cumulative health impacts. Therefore, we propose the intro-duction of a composite AQHI that reports both long-term and short-term health risks. Additionally, the WHO interim targets will be considered as anchor points for various health risk categories. Furthermore, with the increasing ozone levels in Hong Kong and Southern China due to improved NOx mitigation measures, it has been a challenging task in balancing health protection against climate mitigation. However, our findings present a promising outlook. Despite the rise in ozone levels, the combined health risks in Hong Kong and Guang-dong have seen a decline, largely due to reductions in NO2 and PM concentra-tions, both having significant health implications. By shifting from a concentra-tion-based approach to a health risk-based system like the AQHI, our study highlights the prospective of harmonizing health protection and climate mitiga-tion goals. This health-focused framework suggests that rigorous NOx controls can effective-ly serve both objectives in parallel.

Keywords: air quality management, air quality health index, health risk management, air pollution

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Authors: Gaafar Omer BaOmer, Abdulmohsin A. Al-Sofyani, Hassan A. Ramadan

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Drupella is found on coral reefs throughout the tropical and subtropical shallow waters of the Indo-Pacific region. Drupella is muricid gastropod, obligate corallivorous and their population outbreak can cause significant coral mortality. Belt transect surveys were conducted at two sites (Bohairat and Baydah) in Jeddah coast, Saudi Arabia to assess prey preferences for D. cornus with respect to prey availability through resource selection ratios. Results revealed that there are different levels of prey preferences at the different age stages and at the different sites. Acropora species with a caespitose, corymbose and digitate growth forms were preferred prey for recruits and juveniles of Drupella cornus, whereas Acropora variolosa was avoided by D. cornus because of its arborescent colony growth form. Pocillopora, Stylophora, and Millipora were occupied by Drupella cornus less than expected, whereas massive corals genus Porites were avoided. High densities of D. cornus were observed on two fragments of Pocillopora damicornis which may because of the absence of coral guard crabs genus Trapezia. Mean densities of D. cornus per colony for each species showed significant differentiation between the two study sites. Low availability of Acropora colonies in Bayadah patch reef caused high mean density of D. cornus per colony to compare to that in Bohairat, whereas higher mean density of D. cornus per colony of Pocillopora in Bohairat than that in Bayadah may because of most of occupied Pocillopora colonies by D. cornus were physical broken by anchoring compare to those colonies in Bayadah. The results indicated that prey preferences seem to depend on both coral genus and colony shape, while mean densities of D. cornus depend on availability and status of coral colonies.

Keywords: prey availability, resource selection, Drupella cornus, Jeddah, Saudi Arabia

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Authors: R. Udayabhaskar, R. V. Mangalaraja, V. T. Perarasu, Saeed Farhang Sahlevani, B. Karthikeyan, David Contreras

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Bandgap engineering of CeO₂ nanocrystals is of high interest for many research groups to meet the requirement of desired applications. The band gap of CeO₂ nanostructures can be modified by varying the particle size, morphology and dopants. Anchoring the metal oxide nanostructures on graphene sheets will result in composites with improved properties than the parent materials. The presence of graphene sheets will acts a support for the growth, influences the morphology and provides external paths for electronic transitions. Thus, the controllable synthesis of ceria:graphene composites with various morphologies and the understanding of the optical properties is highly important for the usage of these materials in various applications. The development of ceria and ceria:graphene composites with low cost, rapid synthesis with tunable optical properties is still desirable. By this work, we discuss the synthesis of pure ceria (nanospheres) and ceria:graphene composites (nano-rice like morphology) by using commercial microwave oven as a cost effective and environmentally friendly approach. The influence of the graphene on the crystallinity, morphology, band gap and luminescence of the synthesized samples were analyzed. The average crystallite size obtained by using Scherrer formula of the CeO₂ nanostructures showed a decreasing trend with increasing the graphene loading. The higher graphene loaded ceria composite clearly depicted morphology of nano-rice like in shape with the diameter below 10 nm and the length over 50 nm. The presence of graphene and ceria related vibrational modes (100-4000 cm⁻¹) confirmed the successful formation of composites. We observed an increase in band gap (blue shift) with increasing loading amount of graphene. Further, the luminescence related to various F-centers was quenched in the composites. The authors gratefully acknowledge the FONDECYT Project No.: 3160142 and BECA Conicyt National Doctorado2017 No. 21170851 Government of Chile, Santiago, for the financial assistance.

Keywords: ceria, graphene, luminescence, blue shift, band gap widening

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Authors: Stefano Barone

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Seismic retrofit of buildings through base isolation represents a consolidated protection strategy against earthquakes. It consists in decoupling the ground motion from that of the structure and introducing anti-seismic devices at the base of the building, characterized by high horizontal flexibility and medium/high dissipative capacity. This allows to protect structural elements and to limit damages to non-structural ones. For these reasons, full functionality is guaranteed after an earthquake event. Base isolation is applied extensively to both new and existing buildings. For the latter, it usually does not require any interruption of the structure use and occupants evacuation, a special advantage for strategic buildings such as schools, hospitals, and military buildings. This paper describes the application of seismic isolation to three existing masonry buildings in Italy: Villa “La Maddalena” in Macerata (Marche region), “Giacomo Matteotti” and “Plinio Il Giovane” school buildings in Perugia (Umbria region). The seismic hazard of the sites is characterized by a Peak Ground Acceleration (PGA) of 0.213g-0.287g for the Life Safety Limit State and between 0.271g-0.359g for the Collapse Limit State. All the buildings are isolated with a combination of free sliders type TETRON® CD with confined elastomeric disk and anti-seismic rubber isolators type ISOSISM® HDRB to reduce the eccentricity between the center of mass and stiffness, thus limiting torsional effects during a seismic event. The isolation systems are designed to lengthen the original period of vibration (i.e., without isolators) by at least three times and to guarantee medium/high levels of energy dissipation capacity (equivalent viscous damping between 12.5% and 16%). This allows the structures to resist 100% of the seismic design action. This article shows the performances of the supplied anti-seismic devices with particular attention to the experimental dynamic response. Finally, a special focus is given to the main site activities required to isolate a masonry building.

Keywords: retrofit, masonry buildings, seismic isolation, energy dissipation, anti-seismic devices

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Authors: Daniele Losanno, Giorgio Serino

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This paper focuses on parametric analysis of reinforced concrete structures equipped with supplemental damping braces. Practitioners still luck sufficient data for current design of damper added structures and often reduce the real model to a pure damper braced structure even if this assumption is neither realistic nor conservative. In the present study, the damping brace is modelled as made by a linear supporting brace connected in series with the viscous/hysteretic damper. Deformation capacity of existing structures is usually not adequate to undergo the design earthquake. In spite of this, additional dampers could be introduced strongly limiting structural damage to acceptable values, or in some cases, reducing frame response to elastic behavior. This work is aimed at providing useful considerations for retrofit of existing buildings by means of supplemental damping braces. The study explicitly takes into consideration variability of (a) relative frame to supporting brace stiffness, (b) dampers’ coefficient (viscous coefficient or yielding force) and (c) non-linear frame behavior. Non-linear time history analysis has been run to account for both dampers’ behavior and non-linear plastic hinges modelled by Pivot hysteretic type. Parametric analysis based on previous studies on SDOF or MDOF linear frames provide reference values for nearly optimal damping systems design. With respect to bare frame configuration, seismic response of the damper-added frame is strongly improved, limiting deformations to acceptable values far below ultimate capacity. Results of the analysis also demonstrated the beneficial effect of stiffer supporting braces, thus highlighting inadequacy of simplified pure damper models. At the same time, the effect of variable damping coefficient and yielding force has to be treated as an optimization problem.

Keywords: brace stiffness, dissipative braces, non-linear analysis, plastic hinges, reinforced concrete frames

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Authors: Mohammed E. A. Brixi Nigassa, Nassima Labdelli, Ahmed Slami, Arnaud Pothier, Sofiane Soulimane

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According to the world health organization (WHO), there are almost 285 million people with visual disability, 39 million of these people are blind. Nevertheless, there is a code for these people that make their life easier and allow them to access information more easily; this code is the Braille code. There are several commercial devices allowing braille reading, unfortunately, most of these devices are not ergonomic and too expensive. Moreover, we know that 90 % of blind people in the world live in low-incomes countries. Our contribution aim is to concept an original microactuator for Braille reading, as well as being ergonomic, inexpensive and lowest possible energy consumption. Nowadays, the piezoelectric device gives the better actuation for low actuation voltage. In this study, we focus on piezoelectric (PZT) material which can bring together all these conditions. Here, we propose to use one matrix composed by six actuators to form the 63 basic combinations of the Braille code that contain letters, numbers, and special characters in compliance with the standards of the braille code. In this work, we use a finite element model with Comsol Multiphysics software for designing and modeling this type of miniature actuator in order to integrate it into a test device. To define the geometry and the design of our actuator, we used physiological limits of perception of human being. Our results demonstrate in our study that piezoelectric actuator could bring a large deflection out-of-plain. Also, we show that microactuators can exhibit non uniform compression. This deformation depends on thin film thickness and the design of membrane arm. The actuator composed of four arms gives the higher deflexion and it always gives a domed deformation at the center of the deviceas in case of the Braille system. The maximal deflection can be estimated around ten micron per Volt (~ 10µm/V). We noticed that the deflection according to the voltage is a linear function, and this deflection not depends only on the voltage the voltage, but also depends on the thickness of the film used and the design of the anchoring arm. Then, we were able to simulate the behavior of the entire matrix and thus display different characters in Braille code. We used these simulations results to achieve our demonstrator. This demonstrator is composed of a layer of PDMS on which we put our piezoelectric material, and then added another layer of PDMS to isolate our actuator. In this contribution, we compare our results to optimize the final demonstrator.

Keywords: Braille code, comsol software, microactuators, piezoelectric

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Authors: Angel Pérez Sánchez

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Magnet attraction or repulsion is not a product of a strange force from afar but comes from anchored lines of force inside the magnet as if it were reinforced concrete since you can move a small block by taking the steel rods that protrude from its interior. This approach serves as a basis for studying the behavior of diamagnetic materials. The significance of this study is to unify all diamagnetic phenomena: Movement of grapes, cooper approaching a magnet, Magnet levitation, etc., with a single explanation for all these phenomena. The method followed has consisted of observation of hundreds of diamagnetism experiments (in copper, aluminum, grapes, tomatoes, and bismuth), including the creation of own and new experiments and application of logical deduction product of these observations. Approaching a magnet to a hanging grape, Diamagnetism seems to consist not only of a slight repulsion but also of a slight attraction at a small distance. Replacing the grapes with a copper sphere, it behaves like the grape, pushing and pulling a nearby magnet. Diamagnetism could be redefined in the following way: There are materials that don't magnetize their internal structure when approaching a magnet, as ferromagnetic materials do. But they do allow magnetic lines of force to run through its interior, enhancing them without creating their own lines of force. Magnet levitates on superconducting ceramics because magnet gives lines near poles a force superior to what a superconductor can enhance these lines. Little further from the magnet, enhancing of lines by the superconductor is greater than the strength provided by the magnet due to the distance from the magnet's pole. It is this point that defines the magnet's levitation band. The anchoring effect of lines is what ultimately keeps the magnet and superconductor at a certain distance. The magnet seeks to levitate the area in which magnetic lines are stronger near de magnet's poles. Pouring ferrofluid into a magnet, lines of force are observed coming out of the poles. On other occasions, diamagnetic materials simply enhance the lines they receive without moving their position since their own weight is greater than the strength of the enhanced lines. (This is the case with grapes and copper). Magnet and diamagnetic materials look for a place where the lines of force are most enhanced, and this is at a small distance. Once the ideal distance is established, they tend to keep it by pushing or pulling on each other. At a certain distance from the magnet: the power exerted by diamagnetic materials is greater than the force of lines in the vicinity of the magnet's poles. All Diamagnetism phenomena: copper, aluminum, grapes, tomatoes, bismuth levitation, and magnet levitation on superconducting ceramics can now be explained with the support of magnetic lines of force.

Keywords: diamagnetism, magnetic levitation, magnetic lines of force, enhancing magnetic lines

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Authors: Mannar R. Maurya, Bithika Sarkar, Fernando Avecilla

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Peroxidase activity is possibly successfully used for different industrial processes in medicine, chemical industry, food processing and agriculture. However, they bear some intrinsic drawback associated with denaturation by proteases, their special storage requisite and cost factor also. Now a day’s artificial enzyme mimics are becoming a research interest because of their significant applications over conventional organic enzymes for ease of their preparation, low price and good stability in activity and overcome the drawbacks of natural enzymes e.g serine proteases. At present, a large number of artificial enzymes have been synthesized by assimilating a catalytic center into a variety of schiff base complexes, ligand-anchoring, supramolecular complexes, hematin, porphyrin, nanoparticles to mimic natural enzymes. Although in recent years a several number of vanadium complexes have been reported by a continuing increase in interest in bioinorganic chemistry. To our best of knowledge, the investigation of artificial enzyme mimics of vanadium complexes is very less explored. Recently, our group has reported synthetic vanadium schiff base complexes capable of mimicking peroxidases. Herein, we have synthesized monoidovanadium(IV) and dioxidovanadium(V) complexes of pyrazoleone derivateis ( extensively studied on account of their broad range of pharmacological appication). All these complexes are characterized by various spectroscopic techniques like FT-IR, UV-Visible, NMR (1H, 13C and 51V), Elemental analysis, thermal studies and single crystal analysis. The peroxidase mimic activity has been studied towards oxidation of pyrogallol to purpurogallin with hydrogen peroxide at pH 7 followed by measuring kinetic parameters. The Michaelis-Menten behavior shows an excellent catalytic activity over its natural counterparts, e.g. V-HPO and HRP. The obtained kinetic parameters (Vmax, Kcat) were also compared with peroxidase and haloperoxidase enzymes making it a promising mimic of peroxidase catalyst. Also, the catalytic activity has been studied towards the oxidation of 1-phenylethanol in presence of H2O2 as an oxidant. Various parameters such as amount of catalyst and oxidant, reaction time, reaction temperature and solvent have been taken into consideration to get maximum oxidative products of 1-phenylethanol.

Keywords: oxovanadium(IV)/dioxidovanadium(V) complexes, NMR spectroscopy, Crystal structure, peroxidase mimic activity towards oxidation of pyrogallol, Oxidation of 1-phenylethanol

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Authors: Ane Escobar, Paula Angelomé, Mihaela Delcea, Marek Grzelczak, Sergio Enrique Moya

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The antibacterial capacity of bone-anchoring implants can be improved by the use of antibiotics that can be delivered to the media after the surgery. Mesoporous films have shown great potential in drug delivery for orthopedic applications, since pore size and thickness can be tuned to produce different surface area and free volume inside the material. This work shows the synthesis of mesoporous titania films (MTF) by sol-gel chemistry and evaporation-induced self-assembly (EISA) on top of glass substrates. Pores with a diameter of 12nm were observed by Transmission Electron Microscopy (TEM). A film thickness of 100 nm was measured by Scanning Electron Microscopy (SEM). Gentamicin was used to study the antibiotic delivery from the film by means of High-performance liquid chromatography (HPLC). The Staphilococcus aureus strand was used to evaluate the effectiveness of the penicillin loaded films toward inhibiting bacterial colonization. MC3T3-E1 pre-osteoblast cell proliferation experiments proved that MTFs have a good biocompatibility and are a suitable surface for MC3T3-E1 cell proliferation. Moreover, images taken by Confocal Fluorescence Microscopy using labeled vinculin, showed good adhesion of the MC3T3-E1 cells to the MTFs, as well as complex actin filaments arrangement. In order to improve cell proliferation Bone Morphogenetic Protein-2 (BMP-2) was adsorbed on top of the mesoporous film. The deposition of the protein was proved by measurements in the contact angle, showing an increment in the hydrophobicity while the protein concentration is higher. By measuring the dehydrogenase activity in MC3T3-E1 cells cultured in dually functionalized mesoporous titatina films with gentamicin and BMP-2 is possible to find an improvement in cell proliferation. For this purpose, the absorption of a yellow-color formazan dye, product of a water-soluble salt (WST-8) reduction by the dehydrogenases, is measured. In summary, this study proves that by means of the surface modification of MTFs with proteins and loading of gentamicin is possible to achieve an antibacterial effect and a cell growth improvement.

Keywords: antibacterial, biocompatibility, bone morphogenetic protein-2, cell proliferation, gentamicin, implants, mesoporous titania films, osteoblasts

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Authors: Cunyu Zhang

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Through literature review about studies related to tense, it is found that there exist disagreements on the definition and existence of Chinese tense. Influenced by some researches on English language which regard tense as a grammatical category based on the verbal inflections of English, some Chinese researchers claim that there is no tense in Chinese language as there are no verbal inflections involved. Meanwhile, other Chinese researchers hold that Chinese still has tense although its verbs are non-inflectional based on the fact that Chinese lexical expressions can imply temporal meaning. We assume that the reasons for the above disagreements in terms of Chinese tense lie in the fact that all the previous studies prefer to view language “from the below” which means expressions of tense are the core part of these studies. However, there are about 6,000 languages with distinct expressions all over the world. Hence, if the language studies only concentrate on expressions, it must become more difficult to understand the nature of language. By contrast, functions of languages are similar; otherwise, the human beings could not communicate with each other. Therefore, we believe that it is necessary for us to have a theoretical study on Chinese tense within the framework of SFL which holds that language is a system where meaning is the core part while form is just the realization of meaning. In addition, SFL is a general linguistic providing a universal framework for languages all over the world. Therefore, based on Systemic Functional Linguistics, the paper firstly redefines tense as a deictic semantic category for describing the speaker’s temporal location of processes and relevant temporal relations. With reference to this definition, this study explores the meaning system of tense. It is proposed that tense expresses four kinds of meaning, namely interpersonal, experiential, logical and textual meanings. From the interpersonal angle, tense helps to exchange temporal information between the speaker and the listener, and the temporal information refers to the anchoring of a concerned process in the past, present or future by the speaker. From the experiential angle, tense plays a role in the temporal locating of material, mental, relational, existential, behavioral and verbal processes by the speaker. From the logical angle, tense denotes the temporal relations at the two levels of clause and clause complex, and such relations fall into simultaneity, anteriority and posteriority. From the textual angle, tense refers to the temporal relations at the level of text, and the temporal relations in question concern linear serial relations and synchronous serial relations.

Keywords: Chinese, meaning system, Systemic Functional Linguistics, tense

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Authors: Emiliano Matta

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Passive resonant vibration absorbers are among the most widely used dynamic control systems in civil engineering. They typically consist in a single-degree-of-freedom mechanical appendage of the main structure, tuned to one structural target mode through frequency and damping optimization. One classical scheme is the pendulum absorber, whose mass is constrained to move along a curved trajectory and is damped by viscous dashpots. Even though the principle is well known, the search for improved arrangements is still under way. In recent years this investigation inspired a type of bidirectional pendulum absorber (BPA), consisting of a mass constrained to move along an optimal three-dimensional (3D) concave surface. For such a BPA, the surface principal curvatures are designed to ensure a bidirectional tuning of the absorber to both principal modes of the main structure, while damping is produced either by horizontal viscous dashpots or by vertical friction dashpots, connecting the BPA to the main structure. In this paper, a variant of BPA is proposed, where damping originates from the variable tangential friction force which develops between the pendulum mass and the 3D surface as a result of a spatially-varying friction coefficient pattern. Namely, a friction coefficient is proposed that varies along the pendulum surface in proportion to the modulus of the 3D surface gradient. With such an assumption, the dissipative model of the absorber can be proven to be nonlinear homogeneous in the small displacement domain. The resulting homogeneous BPA (HBPA) has a fundamental advantage over conventional friction-type absorbers, because its equivalent damping ratio results independent on the amplitude of oscillations, and therefore its optimal performance does not depend on the excitation level. On the other hand, the HBPA is more compact than viscously damped BPAs because it does not need the installation of dampers. This paper presents the analytical model of the HBPA and an optimal methodology for its design. Numerical simulations of single- and multi-story building structures under wind and earthquake loads are presented to compare the HBPA with classical viscously damped BPAs. It is shown that the HBPA is a promising alternative to existing BPA types and that homogeneous tangential friction is an effective means to realize systems provided with amplitude-independent damping.

Keywords: amplitude-independent damping, homogeneous friction, pendulum nonlinear dynamics, structural control, vibration resonant absorbers

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Authors: Sif J. Friis, Mette Poulsen, Torben Strom Hansen, Peter Herskind, Jens V. Nygaard

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Gastric biomechanics governs a large range of scientific and engineering fields, from gastric health issues to interaction mechanisms between external devices and the tissue. Determination of mechanical properties of the stomach is, thus, crucial, both for understanding gastric pathologies as well as for the development of medical concepts and device designs. Although the field of gastric biomechanics is emerging, advances within medical devices interacting with the gastric tissue could greatly benefit from an increased understanding of tissue anisotropy and heterogeneity. Thus, in this study, uniaxial tensile tests of gastric tissue were executed in order to study biomechanical properties within the same individual as well as across individuals. With biomechanical tests in the strain domain, tissue from the antrum region of six porcine stomachs was tested using eight samples from each stomach (n = 48). The samples were cut so that they followed dominant fiber orientations. Accordingly, from each stomach, four samples were longitudinally oriented, and four samples were circumferentially oriented. A step-wise stress relaxation test with five incremental steps up to 25 % strain with 200 s rest periods for each step was performed, followed by a 25 % strain ramp test with three different strain rates. Theoretical analysis of the data provided stress-strain/time curves as well as 20 material parameters (e.g., stiffness coefficients, dissipative energy densities, and relaxation time coefficients) used for statistical comparisons between samples from the same stomach as well as in between stomachs. Results showed that, for the 20 material parameters, heterogeneity across individuals, when extracting samples from the same area, was in the same order of variation as the samples within the same stomach. For samples from the same stomach, the mean deviation percentage for all 20 parameters was 21 % and 18 % for longitudinal and circumferential orientations, compared to 25 % and 19 %, respectively, for samples across individuals. This observation was also supported by a nonparametric one-way ANOVA analysis, where results showed that the 20 material parameters from each of the six stomachs came from the same distribution with a level of statistical significance of P > 0.05. Direction-dependency was also examined, and it was found that the maximum stress for longitudinal samples was significantly higher than for circumferential samples. However, there were no significant differences in the 20 material parameters, with the exception of the equilibrium stiffness coefficient (P = 0.0039) and two other stiffness coefficients found from the relaxation tests (P = 0.0065, 0.0374). Nor did the stomach tissue show any significant differences between the three strain-rates used in the ramp test. Heterogeneity within the same region has not been examined earlier, yet, the importance of the sampling area has been demonstrated in this study. All material parameters found are essential to understand the passive mechanics of the stomach and may be used for mathematical and computational modeling. Additionally, an extension of the protocol used may be relevant for compiling a comparative study between the human stomach and the pig stomach.

Keywords: antrum region, gastric biomechanics, loading-unloading, stress relaxation, uniaxial tensile testing

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Authors: Lalita, Niladri Sarkar, Subhasis Ghosh

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Since the discovery of high temperature superconductivity (HTSC) in cuprates, several aspects of this phenomena have fascinated physics community. The most debated one is the linear temperature dependence of normal state resistivity over wide range of temperature in violation of with Fermi liquid theory. The linear-in-T resistivity (LITR) is the indication of strongly correlated metallic, known as “strange metal”, attributed to non Fermi liquid theory (NFL). The proximity of superconductivity to LITR suggests that there may be underlying common origin. The LITR has been shown to be due to unknown dissipative phenomena, restricted by quantum mechanics and commonly known as ‘‘Planckian dissipation” , the term first coined by Zaanen and the associated inelastic scattering time τ and given by 1/τ=αkBT/ℏ, where ℏ, kB and α are reduced Planck’s constant, Boltzmann constant and a dimensionless constant of order of unity, respectively. Since the first report, experimental support for α ~ 1 is appearing in literature. There are several striking issues which remain to be resolved if we desire to find out or at least get a clue towards microscopic origin of maximal dissipation in cuprates. (i) Universality of α ~ 1, recently some doubts have been raised in some cases. (ii) So far, Planckian dissipation has been demonstrated in overdoped Cuprates, but if the proximity to quantum criticality is important, then Planckian dissipation should be observed in optimally doped and marginally underdoped cuprates. The link between Planckian dissipation and quantum criticality still remains an open problem. (iii) Validity of Planckian dissipation in all cuprates is an important issue. Here, we report reversible change in the superconducting behavior of high temperature superconductor Bi2Sr2Ca2Cu3O10+δ (Bi-2223) under dynamic doping induced by photo-excitation. Two doped Bi-223 samples, which are x = 0.16 (optimal-doped), x = 0.145 (marginal-doped) have been used for this investigation. It is realized that steady state photo-excitation converts magnetic Cu2+ ions to nonmagnetic Cu1+ ions which reduces superconducting transition temperature (Tc) by killing superfluid density. In Bi-2223, one would expect the maximum of suppression of Tc should be at charge transfer gap. We have observed suppression of Tc starts at 2eV, which is the charge transfer gap in Bi-2223. We attribute this transition due to Cu-3d9(Cu2+) to Cu-3d10(Cu+), known as d9 − d10 L transition, photoexcitation makes some Cu ions in CuO2 planes as spinless non-magnetic potential perturbation as Zn2+ does in CuO2 plane in case Zn-doped cuprates. The resistivity varies linearly with temperature with or without photo-excitation. Tc can be varied by almost by 40K be photoexcitation. Superconductivity can be destroyed completely by introducing ≈ 2% of Cu1+ ions for this range of doping. With this controlled variation of Tc and resistivity, detailed investigation has been carried out to reveal Planckian dissipation underdoped to optimally doped Bi-2223. The most important aspect of this investigation is that we could vary Tc dynamically and reversibly, so that LITR and associated Planckian dissipation can be studied over wide ranges of Tc without changing the doping chemically.

Keywords: linear resistivity, HTSC, Planckian dissipation, strange metal

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Authors: Daniela Ailincai, Bogdan C. Simionescu, Luminita Marin

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Polymer dispersed liquid crystals (PDLC) represent an interesting class of materials which combine the ability of polymers to form films and their mechanical strength with the opto-electronic properties of liquid crystals. The proper choice of the two components - the liquid crystal and the polymeric matrix - leads to materials suitable for a large area of applications, from electronics to biomedical devices. The objective of our work was to obtain PDLC films with potential applications in the biomedical field, using poly vinyl alcohol boric acid (PVAB) as a polymeric matrix for the first time. Presenting all the tremendous properties of poly vinyl alcohol (such as: biocompatibility, biodegradability, water solubility, good chemical stability and film forming ability), PVAB brings the advantage of containing the electron deficient boron atom, and due to this, it should promote the liquid crystal anchoring and a narrow liquid crystal droplets polydispersity. Two different PDLC systems have been obtained, by the use of two liquid crystals, a nematic commercial one: 4-cyano-4’-penthylbiphenyl (5CB) and a new smectic liquid crystal, synthesized by us: buthyl-p-[p’-n-octyloxy benzoyloxy] benzoate (BBO). The PDLC composites have been obtained by the encapsulation method, working with four different ratios between the polymeric matrix and the liquid crystal, from 60:40 to 90:10. In all cases, the composites were able to form free standing, flexible films. Polarized light microscopy, scanning electron microscopy, differential scanning calorimetry, RAMAN- spectroscopy and the contact angle measurements have been performed, in order to characterize the new composites. The new smectic liquid crystal has been characterized using 1H-NMR and single crystal X-ray diffraction and its thermotropic behavior has been established using differential scanning calorimetry and polarized light microscopy. The polarized light microscopy evidenced the formation of round birefringent droplets, anchored homeotropic in the first case and planar in the second, with a narrow dimensional polydispersity, especially for the PDLC containing the largest amount of liquid crystal, fact evidenced by SEM, also. The obtained values for the water to air contact angle showed that the composites have a proper hydrophilic-hydrophobic balance, making them potential candidates for bioapplications. More than this, our studies demonstrated that the water to air contact angle varies as a function of PVAB matrix crystalinity degree, which can be controled as a function of time. This fact allowed us to conclude that the use of PVAB as matrix for PDLCs obtaining offers the possibility to modulate their properties for specific applications.

Keywords: 4-cyano-4’-penthylbiphenyl, buthyl-p-[p’-n-octyloxy benzoyloxy] benzoate, contact angle, polymer dispersed liquid crystals, poly vinyl alcohol boric acid

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Authors: Mamunur Rashid, Jialin Yan

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The current years have witnessed a rapid evolution and integration of artificial intelligence (AI) in various fields, prominently influencing the education industry. Acknowledging this transformative wave, AI tools like ChatGPT and Grammarly have undeniably introduced perspectives and skills, enriching the educational experiences of higher education students. The prevalence of AI utilization in higher education also drives an increasing number of researchers' attention in various dimensions. Departments, offices, and professors in universities also designed and released a set of policies and guidelines on using AI effectively. In regard to this, the study targets exploring and analyzing graduate students' perspectives regarding AI guidelines set by teachers. A mixed-methods study will be mainly conducted in this study, employing in-depth interviews and focus groups to investigate and collect students' perspectives. Relevant materials, such as syllabi and course instructions, will also be analyzed through the documentary analysis to facilitate understanding of the study. Surveys will also be used for data collection and students' background statistics. The integration of both interviews and surveys will provide a comprehensive array of student perspectives across various academic disciplines. The study is anchored in the theoretical framework of self-determination theory (SDT), which emphasizes and explains the students' perspective under the AI guidelines through three core needs: autonomy, competence, and relatedness. This framework is instrumental in understanding how AI guidelines influence students' intrinsic motivation and sense of empowerment in their learning environments. Through qualitative analysis, the study reveals a sense of confusion and uncertainty among students regarding the appropriate application and ethical considerations of AI tools, indicating potential challenges in meeting their needs for competence and autonomy. The quantitative data further elucidates these findings, highlighting a significant communication gap between students and educators in the formulation and implementation of AI guidelines. The critical findings of this study mainly come from two aspects: First, the majority of graduate students are uncertain and confused about relevant AI guidelines given by teachers. Second, this study also demonstrates that the design and effectiveness of course materials, such as the syllabi and instructions, also need to adapt in regard to AI policies. It indicates that certain of the existing guidelines provided by teachers lack consideration of students' perspectives, leading to a misalignment with students' needs for autonomy, competence, and relatedness. More emphasize and efforts need to be dedicated to both teacher and student training on AI policies and ethical considerations. To conclude, in this study, graduate students' perspectives on teacher-provided AI guidelines are explored and reflected upon, calling for additional training and strategies to improve how these guidelines can be better disseminated for their effective integration and adoption. Although AI guidelines provided by teachers may be helpful and provide new insights for students, educational institutions should take a more anchoring role to foster a motivating, empowering, and student-centered learning environment. The study also provides some relevant recommendations, including guidance for students on the ethical use of AI and AI policy training for teachers in higher education.

Keywords: higher education policy, graduate students’ perspectives, higher education teacher, AI guidelines, AI in education

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Authors: Mariia A. Parfenenko, Ilya S. Dantsev, Sergei V. Bochenkov, Natalia V. Vinogradova, Olga S. Groznova, Victoria Yu. Voinova

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Introduction: Autism is the most common neurodevelopmental disorder. Autism is characterized by difficulties in social interaction and adherence to stereotypic behavioral patterns and frequently co-occurs with epilepsy, intellectual disabilities, connective tissue disorders, and other conditions. CHD8 codes for chromodomain-helicase-DNA-binding protein 8 - a chromatin remodeler that regulates cellular proliferation and neurodevelopment in embryogenesis. CHD8 is one of the genes most frequently involved in autism. Patients and methods: 2 unrelated male patients, P3 and P12, aged 3 and 12 years old, underwent whole genome sequencing, which determined that they both had different likely pathogenic variants, both previously undescribed in literature. Sanger sequencing later determined that P12 inherited the variant from his affected mother. Results: P3 and P12 presented with autism, a developmental delay, ataxia, sleep disorders, overgrowth, and macrocephaly, as well as other clinical features typically present in patients with causative variants in CHD8. The mother of P12 also has autistic traits, as well as ataxia, hypotonia, sleep disorders, and other symptoms. However, P3 and P12 also have different cardiac abnormalities. P3 had signs of a repolarization disorder: a flattened T wave in the III and aVF derivations and a negative T wave in the V1-V2 derivations. He also had structural valve anomalies with associated regurgitation, local contractility impairment of the left ventricular, and diastolic dysfunction of the right ventricle. Meanwhile, P12 had Wolff-Parkinson-White syndrome and underwent radiofrequency ablation at the age of 2 years. At the time of observation, P12 had mild sinus arrhythmia and an incomplete right bundle branch block, as well as arterial hypertension. Discussion: Cardiac abnormalities were not previously reported in patients with causative variants in CHD8. The underlying mechanism for the formation of those abnormalities is currently unknown. However, the two hypotheses are either a disordered interaction with CHD7 – another chromodomain remodeler known to be directly involved in the cardiophenotype of CHARGE syndrome – a rare condition characterized by coloboma, heart defects and growth abnormalities, or the disrupted functioning of CHD8 as an A-Kinase Anchoring Protein, which are known to modulate cardiac function. Conclusion: We observed 2 unrelated autistic males with likely pathogenic variants in CHD8 that presented with typical symptoms of CHD8-related neurodevelopmental disorder, as well as cardiac abnormalities. Cardiac abnormalities have, until now, been considered uncharacteristic for patients with causative variants in CHD8. Further accumulation of data, including experimental evidence of the involvement of CHD8 in heart formation, will elucidate the mechanism underlying the cardiophenotype of those patients. Acknowledgements: Molecular genetic testing of the patients was made possible by the Charity Fund for medical and social genetic aid projects «Life Genome.»

Keywords: autism spectrum disorders, chromodomain-helicase-DNA-binding protein 8, neurodevelopmental disorder, cardio phenotype

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Authors: Tiantian Min, Chuanxiang Cheng, Jin Yue

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The growth and reproduction of microorganisms in food packaging can cause food decay and foodborne diseases, which pose a serious threat to the health of consumers and even cause serious economic losses. Active food packaging containing antibacterial bioactive compounds is a promising strategy for extending the shelf life of products and maintaining the food quality, as well as reducing the food waste. However, most active packaging can only act as slow-release effect for antimicrobials, which causes the release rate of antimicrobials not match the growth rate of microorganisms. Stimuli-responsive active packaging materials based on biopolymeric substrates and bioactive substances that respond to some biological and non-biological trigger factors provide more opportunities for fresh food preservation. The biological stimuli factors such as relative humidity, pH and enzyme existed in the exudate secreted by microorganisms have been expected to design food packaging materials. These stimuli-responsive materials achieved accurate release or delivery of bioactive substances at specific time and appropriate dose. Recently, metal-organic-frameworks (MOFs) nanoparticles become attractive carriers to enhance the efficiency of bioactive compounds or drugs. Cellulose nanofibrils have been widely applied for film substrates due to their biodegradability and biocompatibility. The abundant hydroxyl groups in cellulose can be oxidized to carboxyl groups by TEMPO, making it easier to anchoring MOFs and to be further modification. In this study, a pH and enzyme dual-responsive CAR@ZIF-8/TOCNF/PE film was fabricated by in-situ growth of ZIF-8 nanoparticles onto TEMPO-oxidized cellulose (TOCNF) film and further coated with pectin (PE) for stabilization and controlled release of carvacrol (CAR). The enzyme triggered release of CAR was achieved owing to the degradation of pectin by pectinase secreted by microorganisms. Similarly, the pH-responsive release of CAR was attributed to the unique skeleton degradation of ZIF-8, further accelerating the release of CAR from the topological structure of ZIF-8. The composite film performed excellent crystallinity and adsorb ability confirmed by X-ray diffraction and BET analysis, and the inhibition efficiency against Escherichia coli, Staphylococcus aureus and Aspergillus niger reached more than 99%. The composite film was capable of releasing CAR when exposure to dose-dependent enzyme (0.1, 0.2, and 0.3 mg/mL) and acidic condition (pH = 5). When inoculated 10 μL of Aspergillus niger spore suspension on the equatorial position of mango and raspberries, this composite film acted as packaging pads effectively inhibited the mycelial growth and prolonged the shelf life of mango and raspberries to 7 days. Such MOF-TOCNF based film provided a targeted, controlled and sustained release of bioactive compounds for long-term antibacterial activity and preservation effect, which can also avoid the cross-contamination of fruits.

Keywords: active food packaging, controlled release, fruit preservation, in-situ growth, stimuli-responsive

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