Polymerization of acrylamide initiated by the redox system Ce(IV)-4,4′-azobis (4-cyano pentanol)

Summary Acrylamide was polymerized by eeric ion Ce (IV)-4,4-azobis(4-cyano pentanol)(ACP) redox pair in aqueous nitric acid under nitrogen atmosphere. The rate of polymerization is proportional to [M]²,[ACP] and [Ce(IV)]^–1. Termination mechanism which was exclusively linear offered one azo group per polymeric chain. The obtained polyacrylamide can be used as a water soluble initiator for vinyl polymerization.     

Evaluation of adhesion and fatigue of MoS2-Nb solid-lubricant films deposited by pulsed-dc magnetron sputtering

The thin film deposition for tribological applications becomes more and more widespread. The tribological performance of the overlay coatings correlates with coating-substrate adhesion. Hence, it is important to measure adhesive strength. The scratch adhesion test for thin films is extensively used. In this work, MoS₂-Nb coatings deposited by closed-field unbalanced magnetron sputtering (CFUBMS) have been scratch tested in two modes. A multi-mode operation was used as sliding-fatigue, like multi-pass scratching in the same track at different fractions of critical load (unidirectional sliding) and a standard mode using progressive load operation. Failure mechanisms are discussed according to examination of response of very dense microstructure and the adhesion value. The critical load to the first failure (L_C1) was 15 N but the final adhesion value from the film and substrate interface was 120 N (L_C2) as function of the coating thinning. The coefficient of friction (COF) from the multi-scratch for MoS₂-Nb started at a very high value of around 0.067, 0.073, and 0.093 under 5, 8, and 15 N loads respectively and then drops to 0.006, 0.035, and 0.065 at the end of the 1000 cycles. The most significant finding in the test is that when the multi-scratch passes reached to 1000 cycles, micro scale fatigue failures disappeared.     

Machine Learning and Classical Forecasting Methods Based Decision Support Systems for COVID-19

From late 2019 to the present day, the coronavirus outbreak tragically affected the whole world and killed tens of thousands of people. Many countries have taken very stringent measures to alleviate the effects of the coronavirus disease 2019 (COVID-19) and are still being implemented. In this study, various machine learning techniques are implemented to predict possible confirmed cases and mortality numbers for the future. According to these models, we have tried to shed light on the future in terms of possible measures to be taken or updating the current measures. Support Vector Machines (SVM), Holt-Winters, Prophet, and Long-Short Term Memory (LSTM) forecasting models are applied to the novel COVID-19 dataset. According to the results, the Prophet model gives the lowest Root Mean Squared Error (RMSE) score compared to the other three models. Besides, according to this model, a projection for the future COVID-19 predictions of Turkey has been drawn and aimed to shape the current measures against the coronavirus.     

Hexagonal-Type Ising Nanowire with Core/Shell Structure Designed with Half-Integer Spins: Compensation Behaviors and Phase Diagrams in the Temperature and Interaction Planes

The effective field theory with correlation is used to investigate the magnetic behaviors of the mixed spin-1/2 and spin-3/2 hexagonal Ising nanowire (HIN) with core/shell in the crystal field. The total magnetization as a function of the temperature is used to describe the compensation behaviors of the system, and the N-, Q-, P-, R-, and S-type compensation types are given. The dependence of the phase diagrams on interaction parameters is studied in detail and presented the phase diagrams in the six different planes, namely (J ₁, Δ, T), (J _C, Δ, T), (J _S, Δ, T), (J ₁, J _C, T), (J ₁, J _S, T) and (J _C, J _S, T).Besides, the system exhibit second-order phase transition and first-order phase transitions, which can be found via the variations of the total magnetization with the crystal field in the mixed spin-1/2 and spin-3/2 HIN.     

Materials specificity and directed assembly of a gold-binding peptide

Adsorption studies of a genetically engineered gold-binding peptide, GBP1, were carried out using a quartz-crystal microbalance (QCM) to quantify its molecular affinity to noble metals. The peptide showed higher adsorption onto and lower desorption from a gold surface compared to a platinum substrate. The material specificity, that is, the preferential adsorption, of GBP1 was also demonstrated using gold and platinum micropatterned on a silicon wafer containing native oxide. The biotinylated three-repeat units of GBP1 were preferentially adsorbed onto gold regions delineated using streptavidin-conjugated quantum dots (SAQDs). These experiments not only demonstrate that an inorganic-binding peptide could preferentially adsorb onto a metal (Au) rather than an oxide (SiO2) but also onto one noble metal (Au) over another (Pt). This result shows the utility of an engineered peptide as a molecular erector in the directed immobilization of a nanoscale hybrid entity (SAQDs) over selected regions (Au) on a fairly complex substrate (Au and Pt micropatterned regions on silica). The selective and controlled adsorption of inorganic-binding peptides may have significant implications in nano- and nanobiotechnology, where they could be genetically tailored for specific use in the development of self-assembled molecular systems.     

Design of positive feedback driven current-mode amplifiers Z-Copy CDBA and CDTA,and filter applications

In this study, high-performance current-mode amplifiers Z-Copy current differencing buffered amplifier (ZC-CDBA) and current differencing trans-conductance amplifier (ZC-CDTA) are designed. In order to improve input impedances of the amplifiers, a new approach based on positive feedback is proposed. Impedance improvement/reduction is achieved by using only two extra transistors for each input. This number of extra transistors is very few compared to that in conventional negative feedback based improvement techniques. The proposed technique is justified by performing a detailed stability analysis. It is shown that the input impedances of ZC-CDBA and ZC-CDTA can be safely reduced to the level of 50 Ω by considering fabrication scatterings. The proposed amplifiers are verified with analog filter applications, a new KHN and recently proposed biquadratic and frequency agile filters. It is shown that the filters operate accurately at the frequency level of 100 MHz. This is a clear sign of the proposed amplifiers’ high performance. Layout and post layout simulations are done for the proposed circuits using AMS 0.18 µm parameters in Cadence environment.     

Technological intelligence and competitive strategies: An application study with fuzzy logic

During the last few decades, technology and strategies have become one of the most important factors for the countries, firms and for their competitive properties. Technological intelligence, management, forecasting and innovation are big problems for undeveloped countries but considerable strengths for the developed ones and the firms that attach importance to these concepts. This paper describes technology and its concepts and their integration of competitive factors and strategies, also based on the findings and comments of a sample survey of technological intelligence and activities in Turkish Manufacturing Industry.     

Exploratory Stage Lighting Design using Visual Objectives

Lighting is a critical element of theater. A lighting designer is responsible for drawing the audience's attention to a specific part of the stage, setting time of day, creating a mood, and conveying emotions. Designers often begin the lighting design process by collecting reference visual imagery that captures different aspects of their artistic intent. Then, they experiment with various lighting options to determine which ideas work best on stage. However, modern stages contain tens to hundreds of lights, and setting each light source's parameters individually to realize an idea is both tedious and requires expert skill. In this paper, we describe an exploratory lighting design tool based on feedback from professional designers. The system extracts abstract visual objectives from reference imagery and applies them to target regions of the stage. Our system can rapidly generate plausible design candidates that embody the visual objectives through a Gibbs sampling method, and present them as a design gallery for rapid exploration and iterative refinement. We demonstrate that the resulting system allows lighting designers of all skill levels to quickly create and communicate complex designs, even for scenes containing many color‐changing lights.     

Minimum reliable scale selection in 3D

Multiscale analysis is often required in image processing applications because image features are optimally detected at different levels of resolution. With the advance of high-resolution 3D imaging, the extension of multiscale analysis to higher dimensions is necessary. This paper extends an existing 2D scale selection method, known as the minimum reliable scale, to 3D volumetric images. The method is applied to 3D boundary detection and is illustrated in examples from biomedical imaging. The experimental results show that the 3D scale selection improves the detection of edges over single scale operators using as few as three different scales.     

Development of low temperature curing, 120°C, durable, corrosion protection powder coatings for temperature sensitive substrates

Commercial low temperature cure powder coatings, including candidates representative of all the major coating chemistries, were evaluated. Nearly all failed to adequately react at a cure schedule of 120°C for 30 min, and none, even when prepared at their manufacturer’s lowest recommended cure conditions, met the stringent performance needs for temperature-sensitive military applications. Initial research is presented toward developing low temperature cure powder coatings that simultaneously meet all performance requirements at this target cure schedule. Using commercial resins, corrosion inhibitors, and catalysts, this research effort has closed gaps in low temperature cure coating performance and has helped to identify critical deficiencies. This study establishes direction for future developments in new resin and catalyst technologies. Presented at the 31 st Annual International Waterborne, High-Solids, and Powder Coatings Symposium, February 18–20, 2004, in New Orleans, LA.