Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimizing Chemical-Vapor-Deposition Diamond for Nitrogen-Vacancy Center Ensemble Magnetrometry

The nitrogen-vacancy (NV) center in diamond has emerged as a promising platform for highsensitivity, vector magnetic field detection and high spatial resolution magnetic-field imaging due to its unique combination of optical and spin properties. NV diamond magnetometry has enabled a wide array of applications from the noninvasive measurement of a single neuron action potential to the mapping μT-fields in μm-size meteorite grains. To further improve the magnetic sensitivity of an ensemble NV magnetometer, the growth and processing of the host diamond must be taken into account. This thesis presents a systematic study of the effects of diamond processing on bulk chemical-vapor-deposition diamond. In particular, NV chargestate composition and spin decoherence times are measured for diamonds irradiated with 1 MeV electrons at doses of 1×10−5×10 e−/cm2 and thermally annealed at temperatures of 850∘C and 1250∘C. The study provides an optimal range for diamond processing and shows the quenching of the NV center at high irradiation dosage from the creation of additional vacancy-related defects. Thesis Supervisor: Paola Cappellaro Title: Esther and Harold E. Edgerton Associate Professor of Nuclear Science and Engineering Thesis Supervisor: Danielle A. Braje Title: Assistant Group Leader, Quantum Information and Integrated Nanosystems MIT Lincoln Laboratory
Perovskite CsPbX3: A Promising Nonlinear Optical Material and Its Applications for Ambient All‐Optical Switching with Enhanced Stability

Perovskites are demonstrated as an excellent prospect for applications in all‐optical switching due to their excellent nonlinear optical effects. In this contribution, 2D cesium lead iodine (CsPbI3) quantum dots (QDs) and cesium lead bromine iodine (CsPbBrxI3−x) nanosheets (NSs) are prepared, characterized, and applied in all‐optical switching, and their asymmetric nonlinear optical response is also investigated. Moreover, the impact of the beam distortion on the CsPbI3 QDs and CsPbBrxI3−x NSs is systematically analyzed. An all‐optical switching technique based on perovskite QDs and NSs is experimentally investigated, which is realized by modulating the propagation of the signal beam with another controlling beam using spatial cross‐phase modulation. The achievement of all‐optical switching indicates that perovskites can be developed as an excellent optical material for all‐optical signal processing. The contribution reveals the potential applications of perovskites as a new type of optical information material, and it is therefore anticipated that CsPbI3 QDs, CsPbBrxI3−x NSs, and other 2D perovskite NSs could find promising applications in photonics devices (such as optical modulators, optical switchers, and detectors).
Influence of the Capping Ligand on the Band Gap and Electronic Levels of PbS Nanoparticles through Surface Atomistic Arrangement Determination

Lead sulfide (PbS) nanoparticles were synthesized by chemical methods with different sizes and different capping ligands (oleic acid, myristic acid, and hexanoic acid), avoiding ligand exchange procedures, to study the effect of characteristics of the capping ligands on their energy levels and band gap values. Experimental results (UV–vis–NIR, Fourier transform infrared, and Raman spectroscopies, cyclic voltammetry, transmission electron microscopy, and electron energy loss spectroscopy) showed a marked influence of the capping ligand nature on the electro-optical properties of PbS nanoparticles with a very similar size. Differences were observed in the atomistic arrangement on the nanoparticle surface and phonon vibrations with the different capping ligands. These observations suggest that the electro-optical properties of PbS nanoparticles are not only determined by their size, through quantum confinement effects, but also strongly affected by the atomistic arrangement on the nanoparticle surface, which is determined by the capping ligand nature.
SURFACE PROPERTIES OF CHITOSAN COMPOSITES WITH POLY(VINYL ALCOHOL) AND HYDROXYAPATITE

Surface properties of composites containing chitosan (Ch), poly(vinyl alcohol) (PVA) with hydroxyapatite (HAP) were investigated by contact angle measurements and atomic force microscopy (AFM). Thin films of Ch/HAP and Ch/PVA/HAP composites have been formed by casting methods from acetic acid solutions. Measurements of the contact angle for diiodomethane (D), and glycerol (G) on the surface of chitosan films, Ch/HAP and chitosan/PVA/HAP films were made and surface free energy was calculated. It was found that chitosan/HAP or Ch/PVA/HAP blend surface is enriched in high surface energy component i.e. chitosan. The study of composites by AFM showed a completely different morphology when compared with unmodified components. The roughness of composites increase after the addition of hydroxyapatite. This may indicates a strong interaction between the polymeric components and inorganic additive.
Smart Passivation Materials with a Liquid Metal Microcapsule as Self‐Healing Conductors for Sustainable and Flexible Perovskite Solar Cells

The electrical repair of device circuits has been considered a main issue in the area of electronic packaging. Demand for self‐healing conductors as cost‐effective and promising materials for prolonging the durability of devices has increased. Recently, diverse designs of self‐healing and deformable circuits have been introduced in virtue of their high stretchability and conductivity. However, encapsulating a liquid metal with a polymer in a micro‐size container is essential for real applications. In this work, core–shell‐structured liquid metal microcapsules (LMCs, diameter = 2–10 µm) are synthesized via in situ polymerization of urea‐formaldehyde onto liquid metal colloids. Passivation films comprising LMC/polymer composites are simply prepared using phase separation between the capsules and the liquid prepolymer. Capsules ruptured by cutting or pressing release and transport liquid metal to the damaged sites, leading to effective recovery of electrical pathways. Such self‐healing of the metal contacts shows the high potential of LMCs for smart passivation of electronic devices. As an example, flexible perovskite solar cells incorporated with the passivation film demonstrate perfect recovery of the photovoltaic parameters immediately after cutting the metal contact, exhibiting a power conversion efficiency (PCE) retention of 99% relative to the initial value (PCE = 15.07%).
Effect of Carbon Dots on Conducting Polymers for Energy Storage Applications

The influence of carbon dots (Cdots) in conducting polymers (polypyrrole (PPy) and polyaniline (PANI)) was investigated toward high specific capacitance. Herein, a viable in situ chemical oxidative polymerization method was employed to synthesize the polymer@Cdots composites. The enhancements of specific capacitance and long-term stabilities of PPy@Cdots and PANI@Cdots are due to the synergistic effect of polymers and Cdots. Thus, the Cdots in the composite enhanced more than double the capacitance of original polymers: The specific capacitances of composites were 676 and 529 F/g for PPy@Cdots and PANI@Cdots, respectively, at current density of 1 A/g. This report indicates the remarkable capacitance intension and the desirable durability reinforcement of pseudocapacitors by the easy addition of less-conductive carbon material.
Different Shapes of Carbon Nanotubes via Water Assisted Chemical Vapor Deposition

Carbon nanotubes with different shapes have been prepared using water assisted chemical vapor deposition technique (WA-CVD). Different thicknesses of nickel layers were sputtered on alumina substrate. These were treated under high temperature (700 °C) at hydrogen gas to grow nickel nanoparticles (Ni-NPs). Tube furnace (single type), argon and acetylene gases were used for Carbon Nanotubes (CNTs) growth. The FESEM, TEM, HRTEM, Raman spectroscopy, and XRD were used for characterization of the carbon product. The results show that Water Assisted CVD produces CNTs with no trace of amorphous carbon. Nickel catalyst thicknesses (0.5,1,3,3.45,6.8,100 nm) offer different shapes of carbon nanotubes (single walled carbon nanotube, plain MWCNT, helical carbon nanotube, carbon nanofiber).
Production and characterization of activated carbon from petroleum coke

Activated carbons (AC) were prepared from petroleum coke of Khartoum Refinery Company Delayed Coke Unit (KRC-DCU) by chemicalactivation methods with KOH as an active agent. The porous carbons were characterized by iodine value and methylene blue value, Fourier transform infrared spectroscopy and heavy metal content for petroleum cokeand AC. Two samples of porous AC obtained from KRC coke, by KOH activation with 1:4 and 1:5 (Coke: KOH) at 800 °C for 60 min. The iodine number and methylene blue values of these samples were found to be 1248 and 1242 mg g -1 , 43 and 51 mg g -1, respectively.The carbon yields of the two samples were registered to be 68 and 61%. It has been found that Coke to KOH ratio and activation time is effective for preparing high quality porous carbons
Atomic scale origins of sub-band gap optical absorption in gold-hyperdoped silicon

Gold hyperdoped silicon exhibits room temperature sub band gap optical absorption, with potential applications as infrared absorbers/detectors and impurity band photovoltaics. We use first-principles density functional theory to establish the origins of the sub band gap response. Substitutional gold AuSi and substitutional dimers AuSi − AuSi are found to be the energetically preferred defect configurations, and AuSi gives rise to partially filled mid-gap defect bands well offset from the band edges. AuSi is predicted to offer substantial sub-band gap absorption, exceeding that measured in prior experiments by two orders of magnitude for similar Au concentration. This suggests that in experimentally realized systems, in addition to AuSi, the implanted gold is accommodated by the lattice in other ways, including other defect complexes and gold precipitates. We further identify that it is energetically favorable for isolated AuSi to form AuSi − AuSi, which by contrast do not exhibit mid-gap states. The formation of dimers and other complexes could serve as nuclei in the earliest stages of Au precipitation, which may be responsible for the observed rapid deactivation of sub-band gap response upon annealing.Gold hyperdoped silicon exhibits room temperature sub band gap optical absorption, with potential applications as infrared absorbers/detectors and impurity band photovoltaics. We use first-principles density functional theory to establish the origins of the sub band gap response. Substitutional gold AuSi and substitutional dimers AuSi − AuSi are found to be the energetically preferred defect configurations, and AuSi gives rise to partially filled mid-gap defect bands well offset from the band edges. AuSi is predicted to offer substantial sub-band gap absorption, exceeding that measured in prior experiments by two orders of magnitude for similar Au concentration. This suggests that in experimentally realized systems, in addition to AuSi, the implanted gold is accommodated by the lattice in other ways, including other defect complexes and gold precipitates. We further identify that it is energetically favorable for isolated AuSi to form AuSi − AuSi, which by contrast do not exhibit mid-gap states. The forma.
Nonparametric MANOVA via Independence Testing

The $k$-sample testing problem tests whether or not $k$ groups of data points are sampled from the same distribution. Multivariate analysis of variance (MANOVA) is currently the gold standard for $k$-sample testing but makes strong, often inappropriate, parametric assumptions. Moreover, independence testing and $k$-sample testing are tightly related, and there are many nonparametric multivariate independence tests with strong theoretical and empirical properties, including distance correlation (Dcorr) and Hilbert-Schmidt-Independence-Criterion (Hsic). We prove that universally consistent independence tests achieve universally consistent $k$-sample testing and that $k$-sample statistics like Energy and Maximum Mean Discrepancy (MMD) are exactly equivalent to Dcorr. Empirically evaluating these tests for $k$-sample scenarios demonstrates that these nonparametric independence tests typically outperform MANOVA, even for Gaussian distributed settings. Finally, we extend these non-parametric $k$-sample testing procedures to perform multiway and multilevel tests. Thus, we illustrate the existence of many theoretically motivated and empirically performant $k$-sample tests. A Python package with all independence and k-sample tests called hyppo is available from this https URL.
ORBIT CORRECTION WITH MACHINE LEARNING TECHNIQUES AT THE SYNCHROTRON LIGHT SOURCE DELTA

In the last years, artificial intelligence (AI) has experienced a renaissance in many fields. AI-based concepts are nature-inspired and can also be used in the field of accelerator controls. At DELTA, various studies on this subject were conducted in the past. Among other possible applications, the use of neural networks for automated correction of the electron beam position (orbit control) is of interest. Machine learning (ML) simulations with a DELTA storage ring model were already successful. Recently, conventional Feed-Forward Neural Networks (FFNN) were trained on measured orbits to apply local and global beam position corrections to the 1.5–GeV storage ring DELTA. First experimental results are presented and compared with other orbit control methods.
Commitment Schemes from Supersingular Elliptic Curve Isogeny Graphs

In this work we present two commitment schemes based on hardness assumptions arising from super-singular elliptic curve isogeny graphs, which possess strong security properties. The ﬁrst is based on the CGL hash function while the second is based on the SIDH framework, both of which require a trusted third party for the setup phrase. The proofs of security of these protocols depend on properties of non-backtracking random walks on regular graphs. The optimal eﬃciency of these protocols depends on the size of a certain constant, deﬁned in the paper, related to relevant isogeny graphs, which we give conjectural upper bounds for.
Acta Polytechnica

We evaluate the performance of various selection methods for the Monte Carlo Tree Search algorithm in two-player zero-sum extensive-form games with imperfect information. We compare the standard Upper Confident Bounds applied to Trees (UCT) along with the less common Exponential Weights for Exploration and Exploitation (Exp3) and novel Regret matching (RM) selection in two distinct imperfect information games: Imperfect Information Goofspiel and Phantom Tic-Tac-Toe. We show that UCT after initial fast convergence towards a Nash equilibrium computes increasingly worse strategies after some point in time. This is not the case with Exp3 and RM, which also show superior performance in head-to-head matches.
Expectation Formation in Finance and Macroeconomics: A Review of New Experimental Evidence

This paper reviews the recent development and new findings of the literature on learning to forecast experiments (LtFEs). In general, the stylized finding in the typical LtFEs, namely the rapid convergence to the rational expectations equilibrium (REE) in negative feedback markets and persistent bubbles and crashes in positive feedback markets, is a robust result against several deviations from the baseline design (e.g., number of subjects in each market, price prediction versus quantity decision, short term versus long term predictions, predicting price or returns). Recent studies also find a high level of consistency between findings from forecasting data from the laboratory and the field and forecasting accuracy to be crucially dependent on the complexity of the task.
Conversion of Deterministic and Non-Deterministic Finite Automata to Regular Expression using Brzozowski Algebraic Method

Regular expressions are widely used in the field of compiler design, text editor, search for an emailaddress, train track switches, pattern matching, context switching and in many other areas of computer science. Regular expressions are used to represent certain set of string in algebraic manner. The demand of converting regular expression into finite automata and vice versa motivates research into some alternative so that time taken for above is minimized. For conversion of deterministic and nondeterministic finite automata to regular expression, Brzozowski Algebraic method, also known as Arden’s Theorem is used in this paper because of its simplicity and straight forwardness.
How Does Pandemic Influence Sustainable Development and Tourism Development in France?

Since the recent COVID-19 pandemic disturbance to the economies, pandemic discussion and information become important all over the world. This study makes unique attempt to test the pandemic information disclosure influence on sustainable development as well as on tourism development in France. We have also assessed tourism development, energy consumption, and urbanization impact on the sustainable development of France. Using Autoregressive distributed lags method with the annual data of 1996 to 2020, this paper offer novel contribution in the existing literature by showing that pandemic information disclosure has positive impact on sustainable development while information about pandemic adversely affect tourism development of France. On the other hand, tourism development was having highly positive impact on sustainable development while energy consumption negatively has impacted sustainable development revealing to focus on tourism development for sustainable development and to encourage people to start with lives having proper protective measures to avoid COVID-19 pandemic.
Multiple Offers

In search of a job, a worker may receive more than one offer. Focusing on new hires from non-employment, this paper documents (1) over 30 percent of them had multiple offers simultaneously just before starting the present job, (2) the probability of having multiple offers is negatively correlated with the unemployment rate, and (3) relative to workers with one offer, comparable workers with multiple offers enjoy a wage premium of over 10 percent for about nine years. The findings have implications for understanding the contribution of search frictions to wage dispersion and the sullying effect of recessions.
Spot Fishes at the Table: Tracking Retail Investors and Mutual Funds Return

We propose a new definition of mutual fund skill in tracking retail investors through characterizing trading synchronicity between mutual funds and retail flows. Firstly, we find robustness evidence that funds with low trading synchronicity significantly outperform funds with high trading synchronicity. Secondly, through a noisy rational expectations model with heterogeneous skills, we demonstrate the trading synchronicity captures mutual funds’ ability to explore noise retail flows, other than stock picking or market timing. These findings offer new evidence that some funds indeed track retail investors intentionally and that ability to explore retail flows could deliver excess return.
Mutual Fund's Discretionary Portfolio Disclosure Policies

I study the determinants and effects of mutual funds’ voluntary portfolio disclosure policies using hypotheses derived from the moral hazard, adverse selection, and informed trading literature. A majority of funds disclose their portfolio holdings at a higher frequency than the mandatory requirements. Among U.S. active, equity funds, disclosure frequency varies positively with institutional ownership, nonlinearly with performance, and negatively with risk-taking and portfolio liquidity. I also find that funds that change their voluntary portfolio disclosure policies earn higher flows without a degradation in performance. I conclude that funds’ voluntary portfolio disclosures reflect behaviors patterned by models of monitoring, countersignaling, and informed trading: portfolio disclosures help satisfy investors’ monitoring and funds’ signaling needs, while lack thereof protects against front-running and copy-catting.
Content-based Image Retrieval using Tesseract OCR Engine and Levenshtein Algorithm

Image Retrieval Systems (IRSs) are applications that allow one to retrieve images saved at any location on a network. Most IRSs make use of reverse lookup to find images stored on the network based on image properties such as size, filename, title, color, texture, shape, and description. This paper provides a technique for obtaining full image document given that the user has some portions of the document under search. To demonstrate the reliability of the proposed technique, we designed a system to implement the algorithm. A combination of Optical Character Recognition (OCR) engine and an improved textmatching algorithm was used in the system implementation. The Tesseract OCR engine and Levenshtein Algorithm was integrated to perform the image search. The extracted text is compared to the text stored in the database. For example, a query result is returned when a significant ratio of 0.15 and above is obtained. The results showed a 100% successful retrieval of the appropriate file base on the match even when partial query images were submitted. Keywords—Image Retrieval Systems; image processing; Optical Character Recognition (OCR), text matching algorithm, Tesseract OCR engine, Levenshtein Algorithm
Sampling efficiencies of two modified viable cascade impactors

ABSTRACT Prevention of airborne contagious diseases depends on successful characterization of aerosols in the environment. The use of cascade impactors to characterize ambient aerosols is one of the most commonly used methods, providing data on both particle size and concentration. In this study, the use of a cascade impactor recently described in the literature using 8 mL of liquid in Petri dishes (CI-L) was compared with a new method that uses wet membrane filters on top of wax filled Petri dishes (CI-WWMF). Sampling efficiencies of the cascade impactors were evaluated using 0.5, 1, 3, and 5 μm polystyrene latex (PSL) microspheres and aerosol consisting of single spores of Bacillus atrophaeus var. globigii (BG). The sampling efficiency of the CI-L was 6%, 11%, 17%, 21%, and 58% for 0.5, 1, 3, 5 μm PSL microspheres and BG spores, respectively. Higher overall sampling efficiencies of 71%, 91%, 60%, 64%, and 104% were observed for the same size and type of particles for the CI-WWMF. This study indicates that using wet filters on top of wax-filled Petri dishes (CI-WWMF) in a viable cascade impactor is more efficient than the CI-L method for size-selectively collecting biological aerosols from the environment. The CI-WWMF method is useful when a liquid medium is required for identifying and quantifying organisms using polymerase chain reaction (PCR) and immuno-assay techniques. Copyright © 2017 American Association for Aerosol Research
Spontaneous electrical activity in subpopulation of freshly isolated rat uterine myometrial cells

Many types of smooth muscle including uterus exhibit spontaneous electrical and mechanical activity of myogenic origin. Elucidation of the mechanisms responsible for the uterine autorhythmicity is crucial for the understanding of labour. In recent years, pacemaking in GI tract has been attributed to the activity of interstitial cells of Cajal (ICC) (see Hirst & Ward, 2003 for review). A similar mechanism has also been found in some of the urogenital smooth muscles (Sergeant et al. 2000). In our experiments we found that cells resembling the ICCs’ phenotype are present in the rat and human uterus. These cells, however, did not show spontaneous electrical activity attributable to their possible role as an intrinsic uterine pacemaker. In the present study we have investigated the ability of uterine smooth muscle cells to generate spontaneous action potentials.