A generic model for diffusive dynamics of the substrate and fluorescein tagged enzyme in microfluidic platform

Microsystem Technologies - The aim of this study was to develop a model that describes enzymatic conversion in a microfluidic system along with convective and diffusive transport of...     

Highly efficient CoB catalyst using a support material based on Spirulina microalgal strain treated with ZnCl2 for hydrogen generation via sodium borohydride methanolysis

In the study, a different support material based on ZnCl₂‐treated Spirulina microalgal strain (SSMS‐ZnCl₂) was prepared. Then, the SSMS‐ZnCl₂‐CoB catalysts were used as a very efficient catalyst to produce hydrogen via the SB methanolysis. The SB concentration, Co metal percentage in the supported‐catalyst, ZnCl₂ concentration, ZnCl₂ impregnation time, temperature, and reusability experiments were performed. The maximum hydrogen generation rates (HGR) for the SSMS‐ZnCl₂‐CoB at 30°C and 60°C were found to be 9266 and 36 366 mL min^?1 g_cat^?1, respectively. In addition, TOF values for 30°C and 60°C were calculated 33 and 110 L·mol_H2·mol_Co^?1·min^?1 for the methanolysis of SB with SSMS‐ZnCl₂‐CoB catalyst. The activation energy was 31.13 kJ mol^?1. The reusability experiments were repeated five times under the same conditions. The almost 100% conversion was obtained at each use. XRD, FTIR, TEM, SEM‐EDX, and ICP‐MS analysis were performed for SSMS‐ZnCl₂‐CoB characterization.     

Analysis of tweets about football: 2013 and 2018 leagues in Turkey

ABSTRACT

Football has recently developed into a unique sector with complex management and marketing functions, where novel communication technologies are employed. In this paper, we aim to contribute to the numerous fields involving emerging European sports marketing literature, social media analytics, and digital consumer behaviour. Our purpose is to explore Twitter use related with football by analysing real-time streamed data in offering a longitudinal perspective by focusing on 2013 and 2018 leagues in Turkey via the use of social media analytics framework. Retrieved dataset involved randomly selected publicly available 370 thousand and 6.8 million real-time tweets in 2013 and 2018 leagues, respectively. We report that majority of tweets about the football was posted within the three-hour window before the match independent of the match result and the importance of the result. Moreover, pre-match tweeting volume was almost a crystal ball signalling match winning. Our findings are valuable for sports managers and marketers where some key suggestions provided are to involve particular contexts of winning or losing in their after-match marketing plans, to value weekdays as much as the weekends, and to utilise the after-work prime time of social media engagement.     

Friction and wear studies between cylinder liner and piston ring pair using Taguchi design method

This paper reports an experimental study of tribological characteristics of cylinder liner (CL)/piston ring (PR) pair. Reciprocating wear process parameters are optimized for minimum weight loss and friction based on mixed L₁₆ Taguchi orthogonal design with three process parameters, sliding velocity, applied load and oil type. It is observed that sliding velocity have the most significant influence on both weight loss and friction characteristics of CL/PR pair. The interaction of sliding velocity and oil type has some significant influence on weight loss of piston ring. The experimental results are in good agreement with the values from the theoretical model.     

Spirulina microalgal strain as efficient a metal-free catalyst to generate hydrogen via methanolysis of sodium borohydride

Metal-free catalyst based on Spirulina platensis microalgae (SPM) is protonated by phosphoric acid (H₃PO₄) treatment (SPM-H₃PO₄). The microalgae sample is then exposed to heating with different temperatures including 200, 300, and 400 °C (SPM-H₃PO₄-H). The modified microalgae sample based on Spirulina platensis as a catalyst is directly used to generate hydrogen via the methanolysis of sodium borohydride (MSB). The activation temperature, activation time, NaBH4 concentration, catalyst amounts, temperature and reusability tests were carried out. The maximum hydrogen production rates (HGR) obtained for SPM-H₃PO₄-H at temperatures of 30 °C and 60 °C were 3975 and 9600 mLmin⁻¹gcat⁻¹, respectively. At the same time, the activation energy(Ea) of 17.78 kJ mol⁻¹ was obtained. Reusability experiments were performed for this microalgae-based metal-free catalyst. XRD, SEM, FTIR, BET, and TEM analyzes were performed for characterization of these metal-free catalyst samples.     

Detection of weather images by using spiking neural networks of deep learning models

Neural Computing and Applications - The transmission of weather information of a location at certain time intervals affects the living conditions of the people there directly or indirectly....     

Removal of C.I. Basic Blue 41 from aqueous solution by supercritical water oxidation in continuous-flow reactor

Oxidation of aqueous solution of C.I. Basic Blue 41 (BB41), which is model azo dye pollutants, was studied in a continuous-flow reactor that was operated between 400 and 650 °C at a fixed pressure of 25 MPa. The total organic carbon (TOC) concentration of BB41 was in the range of 30.60 and 152.97 mmol/L in the feed stock solution. Hydrogen peroxide (H₂O₂) was used as an oxygen source and the oxidant concentrations were between 73.53 and 489.64 mmol/L in the feed stock solution. The results demonstrated that supercritical water oxidation (SCWO) process decreases the TOC up to 99.87% in very short reaction times (at residence times of 9–19 s). According to the wastewater and oxidant concentrations, the global rate expression was regressed from the complete set of data for each dye solution. As a result of regression analysis, the reaction rate expression for the oxidation of BB41 was determined with the activation energy of 18.88 (±0.9) kJ/mol and the pre-exponential factor of 2.8 (±0.5) mmol^?0.16 L^0.16 s^?1; and the reaction orders for BB41 (based on TOC) and the oxidant were 0.84 (±0.03) and 0.32 (±0.05) in a 95% confidence level.     

Dynamic analysis of an embedded microbeam carrying a moving microparticle based on the modified couple stress theory

In this study, analytical and numerical solution procedures are proposed for vibration of an embedded microbeam under action of a moving microparticle based on the modified couple stress theory (MCST) within the framework of Euler–Bernoulli beam theory. The governing equation and the related boundary conditions are derived by using Hamilton’s principle. The closed form solution of the transverse deflections of the embedded microbeam is obtained using the finite Fourier sine transformation. In the numerical solution, the dynamic deflections are computed by using the Lagrange’s equations in conjunction with the direct integration method of Newmark. The static deflections are also obtained analytically. A detailed parametric study is conducted to study the influences of the material length scale parameter, the Poisson’s ratio, the velocity of the microparticle and the elastic medium constant as well as the solution procedures on the dynamic responses of the microbeam. For comparison purpose, static deflections and free vibration frequencies of the microbeam are obtained and compared with previously published studies. Good agreement is observed. The results show that the above mentioned effects play an important role on the dynamic behavior of the microbeam.     

Non-linear vibration analysis of a functionally graded Timoshenko beam under action of a moving harmonic load

In this paper, non-linear dynamic analysis of a functionally graded (FG) beam with pinned–pinned supports due to a moving harmonic load has been performed by using Timoshenko beam theory with the von-Kármán’s non-linear strain–displacement relationships. Material properties of the beam vary continuously in thickness direction according to a power-law form. The system of equations of motion is derived by using Lagrange’s equations. Trial functions denoting transverse, axial deflections and rotation of the cross-sections of the beam are expressed in polynomial forms. The constraint conditions of supports are taken into account by using Lagrange multipliers. The obtained non-linear equations of motion are solved with aid of Newmark-β method in conjunction with the direct iteration method. In this study, the effects of large deflection, material distribution, velocity of the moving load and excitation frequency on the beam displacements, bending moments and stresses have been examined in detail. Convergence and comparison studies are performed. Results indicate that the above-mentioned effects play a very important role on the dynamic responses of the beam, and it is believed that new results are presented for non-linear dynamics of FG beams under moving loads which are of interest to the scientific and engineering community in the area of FGM structures.     

Dynamic programming solution to the batching problem in just-in-time flow-shops

Mixed-model manufacturing systems are widely used by companies, in order to meet the customers’ demand for a variety of products, in an efficient way. This paper is concerned with a special class of mixed-model manufacturing systems: flow-shops. In a flow-shop, each product has to be processed by a number of machines, following a common route. We study the production smoothing problem under presence of non-zero setup and processing times which also vary among the products. We split the master problem into two sub-problems which are concerned with determining the batch sizes and production sequences, respectively. We develop a dynamic programming procedure to solve the batching problem, and suggest using an existing method from the current literature to solve the sequencing problem. We conduct a computational study and show that our solution approach is effective in meeting the JIT goals and efficient in its computational requirements.