Next generation material interfaces for neural engineering
واسط های مواد نسل بعدی برای مهندسی عصبی-2021
Neural implant technology is rapidly progressing, and gaining broad interest in research fields such as electrical engineering, materials science, neurobiology, and data science. As the potential applications of neural devices have increased, new technologies to make neural intervention longer-lasting and less invasive have brought attention to neural interface engineering. This review will focus on recent developments in materials for neural implants, highlighting new technologies in the fields of soft electrodes, mechanical and chemical engineering of interface coatings, and remotely powered devices. In this context, novel implantation strategies, manufacturing methods, and combinatorial device functions will also be discussed.
Biometric indices of eleven mangrove fish species from southwest Bangladesh
شاخص های بیومتریک یازده گونه ماهی حرا از جنوب غربی بنگلادش-2021
Biometric indices, i.e. i) length-weight relationships (LWRs), ii) form factor (a3.0), iii) length-frequency distributions (LFDs), and iv) condition factors (relative KR and Fulton’s KF) are considered to be very cru- cial in the assessment of fishery studies as they provide information on fish population growth and coastal habitat well-being. The study of biometric indices of mangrove fish has, however, received little attention. Our research investigates the LFDs, LWRs, a3.0, KR and KF of 395 individuals from nine families (Latidae, Engraulidae, Gobiidae, Mugilidae, Synbranchidae, Schilbeidae, Scatophagidae, Plotosidae, and Terapontidae). The LFDs showed that the lowest total length (TL) was 4.57 cm for Stolephorus tri, and highest TL was 56.20 for Monopterus cuchia. The LWRs showed that the b (allometric coefficient) values ranging from 2.01 (Plotosus canius) to 3.29 (Terapon jarbua), appeared as highly significant (P < 0.001). Moreover, the KR values ranged from 0.80 to 1.36, which indicate a good state of health of the population. Our findings could be useful in updating the FishBase (online database) and tracking mangrove fish spe- cies sustainably.© 2021 National Institute of Oceanography and Fisheries. Hosting by Elsevier B.V. This is an open accessarticle under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: Length-weight relationship | Growth | Form factor | Condition | FishBase
Making the invisibles visible: Including animals in sustainability (and) accounting
قابل مشاهده کردن نامرئی ها: شامل حیوانات در حسابداری و پایداری-2021
In this essay we draw attention to a crisis that touches upon a great number of individuals: the plight of non-human animals. Billions of farmed animals are slaughtered each year to produce for instance food and clothes, while wild animals experience various degrees of human-induced harms. Yet, non-human animals are largely invisible in discussions of sustainability and associated accounting efforts. This is due to a problematic ontology that leaves domesticated animals hovering between society and nature while grouping wild animals with their habitats and inanimate things. Our purpose is to consider how to make animals visible in sustainability (and) accounting. To that end, we first illustrate how sociology and philosophy, among other disciplines, have begun to shift towards the view that non-human animals are worthy of our moral, political and legal consideration. We then develop a view of sustainability that explicitly includes animals and introduce an accounting framework with examples of indicators to track progress from no rights to fundamental rights for non-human animals.
keywords: حقوق حیوانات | رفاه حیوانات | شاخص ها | پایداری | Animal rights | Animal welfare | Indicators | Sustainability
Person-identification using familiar-name auditory evoked potentials from frontal EEG electrodes
شناسایی فرد با استفاده از پتانسیل نام-آشنا شنوایی الکترودهای EEG جلو برانگیخته-2021
Electroencephalograph (EEG) based biometric identification has recently gained increased attention of re- searchers. However, state-of-the-art EEG-based biometric identification techniques use large number of EEG electrodes, which poses user inconvenience and consumes longer preparation time for practical applications. This work proposes a novel EEG-based biometric identification technique using auditory evoked potentials (AEPs) acquired from two EEG electrodes. The proposed method employs single-trial familiar-name AEPs extracted from the frontal electrodes Fp1 and F7, which facilitates faster and user-convenient data acquisition. The EEG signals recorded from twenty healthy individuals during four experiment trials are used in this study. Different com- binations of well-known neural network architectures are used for feature extraction and classification. The cascaded combinations of 1D-convolutional neural networks (1D-CNN) with long short-term memory (LSTM) and with gated recurrent unit (GRU) networks gave the person identification accuracies above 99 %. 1D-convolutional, LSTM network achieves the highest person identification accuracy of 99.53 % and a half total error rate (HTER) of 0.24 % using AEP signals from the two frontal electrodes. With the AEP signals from the single electrode Fp1, the same network achieves a person identification accuracy of 96.93 %. The use of familiar-name AEPs from frontal EEG electrodes that facilitates user convenient data acquisition with shorter preparation time is the novelty of this work.
Keywords: Auditory evoked potential | Biometrics | Deep learning | Electroencephalogram | Familiar-name | Person identification
‘Going agile’: Exploring the use of project management tools in fostering psychological safety in group work within management discipline courses
رفتن چابک: بررسی استفاده از ابزارهای مدیریت پروژه در پرورش ایمنی روانشناختی در کار گروهی در دوره های انضباط مدیریت-2021
While psychological safety is widely acknowledged to be a crucial factor in determining how well teams function, little attention has been paid to this phenomenon in management education and HE more broadly. This highlights an important gap, given the ‘thorny’ nature, and pervasive use, of group work. We contribute the first examination of an HE intervention to increase psycho- logical safety. Specifically, through a two-phase mixed methods approach (pre/post surveys and focus groups, student diaries), we examine the implementation of Agile project management principles in both an undergraduate and postgraduate digital marketing course (total n = 131). The findings illustrate that the intervention increased psychological safety along with team- performance, group learning, interpersonal communication and creativity, whilst also reducing the free-rider problem. The study provides three contributions. First, we extend knowledge of psychological safety by showing it can be fostered through interventions providing two core antecedents (supporting facilitation and a cohesive framework). Second, we build knowledge of psychological safety in education by evidencing a greater breadth of positive outcomes, which until now has been mostly limited to knowledge development. Third, we expand understanding of implementing group work interventions in management, providing five important considerations for educational practitioners.
keywords: چابک | ایمنی روانی | کار گروهی | اسکرام | ابزارهای مدیریت پروژه | Agile | Psychological safety | Group work | Scrum | Project management tools
Improved optical and electrical properties for heterojunction solar cell using Al2O3/ITO double-layer anti-reflective coating
بهبود خواص نوری و الکتریکی برای سلول های خورشیدی ناهمگون با استفاده از پوشش ضد انعکاس دو لایه Al2O3/ITO-2021
Silicon heterojunction solar cells have been gaining remarkable attention in the photovoltaic industry in recent years owing to their low temperature coefficient and high efficiency. This study aimed to maximize the short circuit current density (Jsc), which is directly correlated with the absorbance of the solar cells. An advanced ray tracking model and hall effect measurement was used to improve the optical properties of Al2O3/ITO as a double layered anti-reflection coating (DLARC) on the solar cell. RF/DC power sputtering system was used to deposit ITO layer, while atomic layer deposition was used to deposit Al2O3 on ITO to create a DLARC. An average decrease in reflection from 9.33% to 4.74% and enhancement in EQE from 76.89% to 84.34% were observed for the DLARC in the wavelength spectrum at 300–1100 nm. It also exhibited a higher Jsc value of 41.13 mA/cm2 and maximum conversion efficiency of 21.6%. The findings of both simulation and experiments showed that the Al2O3/ITO DLARC has better anti-reflection properties than a single-layer ITO coating.
Keywords: Silicon heterojunction solar cell | Double layered anti-reflection coating | Optical Properties | Electrical Properties
Moisture dependence of electrical resistivity in under-percolated cement-based composites with multi-walled carbon nanotubes
وابستگی مقاومت الکتریکی به رطوبت در کامپوزیت های پایه سیمانی کم نفوذ با نانولوله های کربنی چند جداره-2021
Cement-based piezoresistive composites have attracted significant attention as smart construction materials for embedding self-sensing capability in concrete infrastructure. Although a number of studies have been conducted using multi-walled carbon nanotubes (MWCNTs) as a functional filler for self-sensing cement-based composites, studies addressing the influence of the internal moisture state on the electrical properties are relatively scant. In this study, we aim to experimentally investigate the effect of internal moisture state on the electrical resistivity of cement-based composites containing MWCNTs as an electrically conductive medium to raise a need for calibration of self-sensing data considering the internal moisture state. To this end, the moisture dependence of electrical resistivity in under-percolated cement-based composites was mainly evaluated, along with other material properties such as strength, shrinkage, and flowability. Results revealed that the electrical resistivity increased almost linearly as the internal relative humidity (IRH) decreased, and the increase was more pronounced below the percolation threshold. In addition, it was found that the strength gained by the microfiller effect of MWCNTs was significantly reduced particularly in under-percolated mixtures, leading to overall strength reductions. Furthermore, this study showed that the more the MWCNT was added, the smaller the flowability was obtained due to the increased viscosity of the mixture. The findings of this study are expected to provide pivotal information for accurate and reliable interpretations of self-sensing data generated by MWCNT-embedded cement-based composites.
Keywords: carbon nanotubes | cement-based composites | electrical resistivity | internal relative humidity | percolation threshold | self-sensing
3D-printable conductive materials for tissue engineering and biomedical applications
مواد رسانای قابل چاپ سه بعدی برای مهندسی بافت و کاربردهای زیست پزشکی-2021
Many patients that undergo autografting suffer from donor site morbidity and risk of immune rejection. Tissue engineering is receiving considerable attention as engineered tissues could help overcome the drawbacks of autografts and achieve better performance on tissue repair, replacement and regeneration. Conductivity is one of the desired properties of engineered scaffolds and tissue constructs as bioelectricity plays an important role in the native physiological environment. Hence, conductive materials have been extensively used in the making of biosensors, tissue engineering scaffolds and drug delivery systems to elicit electrically-mediated signals, thus mimicking the natural cellular environment. Conductive polymers, carbon-based materials, and metal nanoparticles are the main categories of conductive materials used. Ionic liquids, especially biocompatible ionic liquids, is currently being explored as a competitive filler composite to greatly improve the conductivity of polymers with little to zero cytotoxicity. The effects of electrical stimulation on cell alignment, migration, proliferation, and differentiation as well as detailed properties of different types of conductive materials are briefly yet succinctly reviewed. Furthermore, 3D printing of conductive scaffolds and hydrogels, and their corresponding biomedical applications are also discussed.
Keywords: Conductive biomaterials | Bioprinting | Tissue engineering | Ionic liquids | Electrical stimulation
Digital extraction: Blockchain traceability in mineral supply chains
استخراج دیجیتال: قابلیت ردیابی بلاکچین در زنجیره های تأمین مواد معدنی-2021
Digital data — including technologically-mediated data generated by blockchain-enabled traceability — is performing an increasingly integral role in extractive operations, but scarce attention has been paid to the structuring effect of these digital technologies or the socio-economic spatiality of data-driven mining operations. Drawing on extensive qualitative research (interviews, participant observation, and two sets of survey data among actors relevant to these mineral supply chains), this article advances the notion of “digital extraction” todescribe the collection, analysis, and instrumentalization of digital data generated under the banner of blockchain-based due diligence, chain of custody certifications, and various transparency mechanisms, situated alongside and in support of mineral extraction. The article mobilizes concepts from political geography and political ecology to argue that digital technologies of traceability in extractive processes potentially create new forms of control and exclusion or exacerbate existing social, political, and territorial dispossession through asymmetric relations of power and knowledge in mineral supply chains. Despite industry efforts to make mineral supply chains more sustainable by resorting to digital certification and traceability, the strategic uses of un- certainty, ignorance, and ambiguity undergirding blockchain-enabled traceability systems fail to challenge existing inequalities in resource use and access or fulfill the promise of transparency and accountability.
Keywords: Blockchain | Traceability | Mining | Digital extraction | Certification | Digital technology | Political ecology
IFRS convergence and accounting quality: India a case study
همگرایی و کیفیت حسابداری IFRS: مطالعه موردی هند-2021
This study examines the impact on accounting quality in India after converging Indian generally accepted accounting principles (IGAAP) with International Financial Reporting Standards (IFRS). The converged form of IGAAP is referred as Indian Accounting Standards (Ind AS). Using a pre-and post-IFRS adoption period design, we compare the quality of accounting information reported under IGAAP and Ind AS. Our results show that accounting quality deteriorates immediately after the adoption of Ind AS. In particular, we document that the implementation of IFRS-converged standards results in lower variability in net income, a higher magnitude of discretionary accruals, less timely recognition of losses, and lower value relevance of reported earnings. Subsequent tests suggest that the deterioration in accounting quality ameliorates with the passage of time. The findings of the study suggest that there may be a learning curve for the benefits of IFRS adoption/convergence to diffuse over time through a system. Moreover, simply adopting or converging to IFRS without concurrent changes in institutional and enforcement frameworks may not result in improvements in accounting quality, especially in countries with weak regulatory jurisdictions. Consequently, more attention needs to be paid to implementation and diffusion issues, such as integrating IFRS intentionally in the University curriculum and providing workshops and continuing education courses to improve stakeholder familiarity with IFRS. Improvements in the institutional structures of financial reporting should also be implemented.
keywords: همگرایی | کیفیت حسابداری | هندوستان | IFRS | Convergence | Ind AS | Accounting quality | India