Miracle-dz/UniFAR-FTUs huggingface dataset:
Gradient and lamellar heterostructures for superior mechanical properties

Heterostructured (HS) materials are a novel class of materials with mechanical properties that are superior over their conventional homogeneous counterparts. They are composed of HS zones with a dramatic difference in mechanical behaviors, which produces a synergistic effect on mechanical properties that are above the prediction by the rule-of-mixtures. Among all heterostructures, the two most studied are grain-size gradient structure and heterolamellar structure. These two heterostructures produce typical heterogeneous deformation during tensile deformation, producing long-range back stress in the soft zones and forward stress in the hard zones, which collectively produces hetero deformation-induced (HDI) stress to enhance the yield strength before yielding, and HDI hardening after yielding to retain ductility. In this article, we will focus on these two types of heterostructures. The issues, concerns, and progress are reviewed with the emphasis on the synergistic effect of mechanical properties, the fundamentals of several special plastic behaviors (e.g., strain gradient, HDI hardening and strain hardening), the plastic deformation mechanism, and the relationship between the microstructure and properties.
Psychological predictors of protective behaviours during the Covid‐19 pandemic: Theory of planned behaviour and risk perception

Abstract The Covid‐19 outbreak was declared a public health emergency by the World Health Organization in January 2020. As a consequence, several protective measures were urged by national governments in order to limit the spread of the pandemic. Drawing on the literature on health behaviours, in the present study, we investigated the psychological factors (i.e., attitudes, social norms, perceived behavioural control, intentions, and risk perception) that were associated with two highly recommended behaviours: frequent hand washing and social distancing (i.e., staying at home except for essential reasons). The study employed a correlational design with a follow‐up. A questionnaire including measures of psychological predictors was administered via social media to a sample of 403 adults residing in Italy during the lockdown. Self‐reported behaviours were assessed one week later. Findings showed that attitudes, social norms, perceived behavioural control were significantly related to hand washing and social distancing through intentions. Risk perception was a significant predictor of social distancing but not of hand washing. These findings suggest that intervention and communication strategies aimed at encouraging preventive measures during the Covid‐19 pandemic should be organized taking into account multiple factors which partially differ depending on the type of behaviour considered. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement.
Nanchizi New Courtyard Housing in Beijing: Residents’ Perceptions and Experiences of the Redevelopment

Cultural sustainability is the theoretical framework for this study, which investigates Nanchizi (“South Pond”) new courtyard housing experimental project constructed in Beijing, China, in 2003. It is located in a traditional courtyard house neighborhood right to the east of the Forbidden City, in a culturally and politically sensitive area that the initial scheme had even caught the attention of UNESCO. The redevelopment project has restored numerous single-storey traditional courtyard houses that were in relatively good condition, demolished those in poor condition, and rebuilt two-storey new courtyard housing units with modern facilities and shared courtyards whose style and features resemble some aspects of Beijing siheyuan. This 2007-2008 onsite survey and semi-structured interviews with residents, project architect, and lead developer critically examine this approach to historic preservation in China. The findings reveal that communal courtyards promote social interaction and private courtyards facilitate cultural activities, despite some issues raised by the residents, including irrational unit design and poor construction quality, among others. The study attempts to offer valuable lessons and proposes a new courtyard garden house design template for discussion and future practice.
Flow-assisted visual tracking using event cameras

Rui Jiang, CelePixel Technology Co. Ltd, 71 Nanyang Drive, Singapore 638075. Email: rui_jiang@u.nus. edu Abstract The data from event cameras not only portray contours of moving objects but also contain motion information inherently. Herein, motion information can be used in event‐ based and frame‐based object trackers to ease the challenges of occluded objects and data association, respectively. In the event‐based tracker, events within a short interval are accumulated. Within the interval, the histogram of local time measurements (or ‘motion histogram’) is proposed as the feature to describe the target and candidate regions. Then the mean‐shift tracking approach is used by shifting the tracker towards similarity maximisation on motion histograms between target and candidate regions. As for the frame‐based tracker, given the assumption that a single object moves at a constant velocity on the image plane, the distribution of local timestamps is modelled, followed by which object‐level velocities are obtained from parameter estimation. We then build a Kalman‐based ensemble, in which object‐level velocities are deemed as an additional measurement on top of object detection results. Experiments have been conducted to measure the performance of proposed trackers based on our self‐collected data. Thanks to the assistance from motion information, the event‐based tracker successfully differentiates partially overlapped objects with distinct motion profiles; The inter‐frame tracker avoids data association failure on fast‐moving objects and leads to fast convergence on object velocity estimation.
A Novel Design of Blowfish Algorithm for Image Security

In order to improve the security and efficiency of image encryption systems comprehensively an image encryption based on enhanced design of Blowfish scheme is proposed. The proposed system is employed block based image encryption technique combined with chaotic map properties. Firstly the digital image is scrambled and decomposed into several key based blocks randomly to decorrelated the relationship between original and processed image then each block is passed through an enhanced blowfish algorithm. The enhancement in design is to gain advantage of the strong facility, which is maintained by blowfish algorithm by overcoming its flaws, which leads to a significant improvement in security/performance. As a result the proposed system offers good performance for image encryption. The proposed algorithm is 320-bit Blowfish-like block cipher, where cascaded looking composition of F-functions is used instead of rounds. The key is accepted a variable length up to 400 bytes. The pragmatic aim of the proposed system is to decrease memory requirements and execution time while keeping the cipher simple and highly adaptable to future demands. To ensure improved encryption algorithm, the implementation of both techniques has been carried out for experimental purposes which is showed that the original image has a flat histogram after encrypted, a decreasing correlation between adjacent pixels in all color components and increasing entropy for the cases studied. The proposed algorithm has a sufficiently large key space and a very high sensitivity to the key. A comparative study with previous Blowfish algorithm shows the superiority of the modified algorithm.
Application of Neutron Flux from PUSPATI TRIGA Mark II Research Reactor in Enhancing Superconducting Properties of BSCCO Superconductor

The PUSPATI TRIGA Mark II Research Reactor is currently been used in various applications such as Neutron Activation Analysis (NAA), Delayed Neutron Activation Analysis (DNAA), radioisotope production for medical, industrial and agricultural purposes, Neutron Radiography and Small Angle Neutron Scattering (SANS). However, there are not much research activities on utilizing neutron flux from the reactor to study properties of superconducting materials. For superconductors to be fabricated into components of electrical and magnetic devices, the sustainability of the transition temperature, TC and the transport critical current density, JC of the materials is vital to ensure the durability and effectiveness of the devices. A strong superconducting flux pinning capability of superconductors is necessary to maintain high TC and larger JC. Meanwhile, exposure of superconductors to neutron flux is able to create the self-organization of defects that are responsible in producing higher TC and JC in superconductors where the defects act as the flux pinning centres. In this paper, we report the utilization of neutron flux from the PUSPATI TRIGA Mark II research reactor in enhancing the TC and JC of bismuth-strontium-calcium-copper oxide (BSCCO) superconductor. Appropriate sample holder and shielding was fabricated as protection from radiation effect. In this work, 2212-phase BSCCO superconductor (Bi-2212 phase) samples were synthesized using the conventional solid-state reaction method. The samples underwent fast neutron irradiation with neutron flux of 2.0 × 1011 neutrons/(cm2.s) for 6 hours. Results showed that the TC of the samples improved slightly, and the JC was found to increase by more than 3 folds.
Comparative Study on Electronic Structure and Optical Properties of α-Fe2O3, Ag/α-Fe2O3 and S/α-Fe2O3

The electronic structures and optical properties of pure, Ag-doped and S-doped α-Fe2O3 were studied using density functional theory (DFT). The calculation results show that the structure of α-Fe2O3 crystal changes after Ag and S doping, which leads to the different points of the high symmetry of Ag-doped and S-doped α-Fe2O3 with that of pure α-Fe2O3 in the energy band, as well as different Brillouin paths. In addition, the band gap of α-Fe2O3 becomes smaller after Ag and S doping, and the optical absorption peak shifts slightly toward the short wavelength, with the increased peak strength of S/α-Fe2O3 and the decreased peak strength of Ag/α-Fe2O3. However, the optical absorption in the visible range is enhanced after Ag and S doping compared with that of pure α-Fe2O3 when the wavelength is greater than 380 nm, and the optical absorption of S-doped α-Fe2O3 is stronger than that of Ag-doped α-Fe2O3.
I.P.O. determinants of delisting risk: Lessons from the Athens Stock Exchange

ABSTRACT Using data from the Athens Stock Exchange, we investigate early warning signs of delisting risk. We find that the probability of delisting and time to delist are positively associated with relative offer size and earnings’ manipulation, and negatively associated with hot-issuance periods and the joint effects of audit quality, amount of information in the I.P.O. prospectus, and the percentage of non-voluntary information. Our results are more strongly in line with asymmetric information explanations and more prevalent for voluntary delisted firms. Documenting I.P.O. survival factors for a new and different class of stocks extends the range of explanations for delisting risk.
SIMULTANEOUS ESTIMATION OF BECLOMETHASONE DIPROPIONATE AND CLOTRIMAZOLE BY Q - ABSORPTION RATIO METHOD

A simple UV spectroscopic method was developed and validated for the estimation of Beclomethazone dipropionate and Clotrimazole in bulk and pharmaceutical dosage form using methanol and buffer as solvent. The quantification was achieved at 240nm. Beers law was obeyed in the concentration range of 10-100 μg/ml for Clotrimazole and 2.5-25 μg/ml for Beclomethasone. The results of analysis have been validated statistically. The relative standard deviation was found to be less than 2.0%. The assay result of marketed formulation was calculated. The present result shows that the proposed method can be successfully implemented for the estimation of Beclomethasone dipropionate and Clotrimazole in bulk and its marketed formulations.
Traditional market sustainability in the perspective of market managers: A study at the Slipi Market Jakarta

Traditional markets are often evaluated based on consumer judgment. Consumers are considered as determinants of the sustainability of traditional markets from the purchasing side. Even though the managers have their view of the sustainability of their business facilities. Managers have an essential role in good traditional market management. Besides, there are not many studies exploring traditional markets from the managers’ perspective. Therefore, it is necessary to study the sustainability of traditional markets based on the managers’ perspective. This study used a descriptive qualitative method with in-depth interviews that assessed three aspects: environmental, economic, and social. Interviews were conducted with managers at the Slipi Market, Jakarta. The results show that environmental factors support traditional markets’ sustainability as a priority, namely the provision of building infrastructure and waste management, followed by economic factors and social factors. Traditional markets will not be lost by the rapid growth in the number of modern shopping centers because traditional markets are the driving force of the people’s economy.
Industrial perspectives on earth abundant, multinary thin film photovoltaics

The most efficient earth abundant, non-toxic thin film multelemental PV devices are fabricated from Cu, Zn, Sn, S and Se, with the chemical formula of Cu2ZnSn(SxSe1−x)4 (CZTS,Se). This material has enjoyed relatively rapid increases in efficiency from its inception to its present-day power conversion efficiency of 12.6%. But further increases in efficiency have been hampered by the inability to substantially increase Voc, the open circuit voltage. In this review article we will discuss the fundamentals of this important kesterite material including methods of film growth, post growth processing and device fabrication. Detailed studies of the properties of CZTS,Se including chemical, structural and electronic as well as full device electrical characterization have been performed in an effort to coax out the critical issues that limit performance. These experimental studies, enhanced by density functional theory calculations have pointed to fundamental bulk point defects, such as Cu–Zn antisites, and clusters of defects, as the primary culprits in limiting Voc increases. Improvements in device performance through grain boundary passivation and interface modifications are described. Exfoliation of functioning solar cells to expose the back surface along with engineering of new back contacts designed to impose electrostatic fields that drive electron-hole separation and increase Voc are discussed. A parallel route to increasing device performance by alloying Ag with CZTS,Se in order to inhibit Cu–Zn antisite defect formation has shown significant improvement in material properties. Finally, applications of high S (and hence higher Voc) CZTS,Se based devices to energy harvesting for ‘Internet-of-Things’ devices is discussed.
Belt Conveyors Rollers Diagnostics Based on Acoustic Signal Collected Using Autonomous Legged Inspection Robot

Growing demand for raw materials forces mining companies to reach deeper deposits. Difficult environmental conditions, especially high temperature and the presence of toxic/explosives gases, as well as high seismic activity in deeply located areas, pose serious threats to humans. In such conditions, running an exploration strategy of machinery parks becomes a difficult challenge, especially from the point of view of technical facilities inspections performed by mining staff. Therefore, there is a growing need for new, reliable, and autonomous inspection solutions for mining infrastructure, which will limit the role of people in these areas. In this article, a method for detection of conveyor rollers failure based on an acoustic signal is described. The data were collected using an ANYmal autonomous legged robot inspecting conveyors operating at the Polish Ore Enrichment Plant of KGHM Polska Miedź S.A. , a global producer of copper and silver. As a part of an experiment, about 100 m of operating belt conveyor were inspected. The sound-based fault detection in the plant conditions is not a trivial task, given a considerable level of sonic disturbance produced by a plurality of sources. Additionally, some disturbances partially coincide with the studied phenomenon. Therefore, a suitable filtering method was proposed. Developed diagnostic algorithms, as well as ANYmal robot inspection functionalities and resistance to underground conditions, are developed as a part of the “THING–subTerranean Haptic INvestiGator” project.
IpDFT-Tuned Estimation Algorithms for PMUs: Overview and Performance Comparison

The Interpolated Discrete Fourier Transform (IpDFT) is one of the most popular algorithms for Phasor Measurement Units (PMUs), due to its quite low computational complexity and its good accuracy in various operating conditions. However, the basic IpDFT algorithm can be used also as a preliminary estimator of the amplitude, phase, frequency and rate of change of frequency of voltage or current AC waveforms at times synchronized to the Universal Coordinated Time (UTC). Indeed, another cascaded algorithm can be used to refine the waveform parameters estimation. In this context, the main novelty of this work is a fair and extensive performance comparison of three different state-of-the-art IpDFT-tuned estimation algorithms for PMUs. The three algorithms are: (i) the so-called corrected IpDFT (IpDFTc), which is conceived to compensate for the effect of both the image of the fundamental tone and second-order harmonic; (ii) a frequency-tuned version of the Taylor Weighted Least-Squares (TWLS) algorithm, and (iii) the frequency Down-Conversion and low-pass Filtering (DCF) technique described also in the IEEE/IEC Standard 60255-118-1:2018. The simulation results obtained in the P Class and M Class testing conditions specified in the same Standard show that the IpDFTc algorithm is generally preferable under the effect of steady-state disturbances. On the contrary, the tuned TWLS estimator is usually the best solution when dynamic changes of amplitude, phase or frequency occur. In transient conditions (i.e., under the effect of amplitude or phase steps), the IpDFTc and the tuned TWLS algorithms do not clearly outperform one another. The DCF approach generally returns the worst results. However, its actual performances heavily depend on the adopted low-pass filter.
Fabrication, Characterization and In Vitro Cytotoxicity of Mesoporous β-Tricalcium Phosphate Using the Spray Drying Method

Mesoporous beta tricalcium phosphate (β-TCP) has recently attracted significant interest as an artificial bone tissue in orthopedics. However, a scalable process is required to meet future demands. Spray drying is one of the potential synthesis methods owing to its low cost and scalable production. In this study, various mesoporous β-TCP powders were calcined in the range of 800 to 1100 °C, with particle sizes ranging from ~0.3 to ~1.8 μm, specific surface areas from ~16 to ~64 m2/g, and average pore sizes of 3 nm. Except for the 800 °C calcined powder, the other β-TCP powders (calcination temperatures of 900, 1000, and 1100 °C) exhibited no cytotoxicity. These results indicate that spray-dried mesoporous β-TCP powders were obtained. Finally, the corresponding formation mechanisms are discussed.
Does Foreign Aid Work Well in Developing Countries? A Mediating Effect Approach

The purpose of this paper is to find the impact of the coefficient of aggregated and disaggregated aid in Asia, Africa and Latin America due to the causal mechanisms that transmit the effect through mediating variables such as investment, government consumption and import. We employed the fixed effect estimation procedure over the period of 1992-2016 with a sample of 29 countries. African countries are experiencing a negative total effect of multilateral aid on GDP which mediate via import. In Latin American countries, ODA, which mediates through government consumption, induce a greater positive impact than aid that transmits from investment. In Asian countries, ODA, which mediates through government consumption, induce a less negative impact than aid which transmit from investment. When the amount of ODA mediates through the causal path of import, the positive impact of aid is reduced by around 27 percent in Latin America while the negative impact of aid is reduced by around 55 percent in Asia. In case of aid heterogeneity, bilateral aid induces relatively promising advantage for developing countries. Accordingly, even though we used a different approach and our estimates are therefore not directly comparable to those of Burnside-Dollar (2000), our findings are very consistent with their finding that ‘aid effectiveness is conditional on policy’. JEL codes E22; F3; F35; H61; O11; O47
High-Throughput First-Principles Search for Ceramic Superlattices with Improved Ductility and Fracture Resistance

Abstract Superlattices—alternating coherently grown materials of nm thicknesses—proved their potential for enhancing typically antagonistic properties of ceramics: ductility, hardness, and fracture toughness. Material selection, however, is far from trivial, as superlattice films do not simply combine mechanical properties of their layer components. Here we employ high-throughput density functional theory calculations to develop design guidelines for nanolaminates combining cubic transition metal nitride and/or carbide ceramics. Out of 153 MX/M*X* superlattices (M, M* = Al, Ti, Zr, Hf, Nb, V, Ta, Mo, W, and X, X* = C, N) 145 are chemically and mechanically stable and most often contain vacancies on the non-metallic sublattice. Superior ductility together with moderate-to-high fracture toughness and interface strength (above that of the cubic TiN) narrow the set of perspective candidates. Key ingredients promoting the interface-induced enhancement of hardness and/or fracture toughness are lattices parameter and shear modulus mismatch of the layer components. Adding the requirement of phonon stability yields MoN/M*N, M* = Nb, Ta, Ti; TiN/WN (nitrides); HfC/M*N, M* = Mo, W; NbC/M*N, M* = Mo, W; TaC/M*N, M* = Mo, W; VC/M*N, M* = Hf, Ta, Zr (carbonitrides); as the top candidates for novel superlattice films.
A mechanistic study on tumour spheroid formation in thermosensitive hydrogels: Experiments and mathematical modelling

A tumour is a complex, growing tissue with a dynamic microenvironment. Its shape and size affect mass transport and thus the ability of drugs to penetrate into the tumour. Three-dimensional (3D) tumour spheroid culture has thus been recognised as an advanced tool for anti-cancer drug screening. However, the use of tumour spheroids has been hampered by the large variations in spheroid size, their irregular shape and the labour-intensive culture process. We explore thermosensitive hydrogels, P(NIPAM-AA), for culturing tumour spheroids and compare our approach with a traditional suspension culture method (non-adhesive surface) in terms of cell proliferation, tumour spheroid size distribution and spheroid morphology. Spheroids cultured in the microgel network show a narrower size distribution and a more spherical shape. We hypothesised that these observations could be explained by the fact that cells are homogeneously retained inside the hydrogels, cell aggregate formation is much slower due to network resistance and the cell death rate is smaller in comparison with the suspension culture. We developed a cellular automata (CA) model to validate these hypotheses. Spheroid formation with different parameter values, representing culture in suspension and in microgels, is simulated. Our results are consistent with the hypothesis that the microgel culture produces a more uniform size distribution of spheroids as a result of reduced cell death and the gel network resistance.