A Study on Combinatories in Discrete Mathematics

The next two chapters deal with Set Theory and some related topics from Discrete Mathematics. This chapter develops the basic theory of sets and then explores its connection with combinatorics (adding and multiplying; counting permutations and combinations), while Chapter 5 treats the basic notions of numerosity or cardinality for finite and infinite sets.Most mathematicians today accept Set Theory as an adequate theoretical foundation for all of mathematics, even as the gold standard for foundations.* We will not delve very deeply into this aspect of Set Theory or evaluate the validity of the claim, though we will make a few observations on it as we proceed. Toward the end of our treatment, we will focus on how and why Set Theory has been axiomatized. But even disregarding the foundational significance of Set Theory, its ideas and terminology have become indispensable for a large number of branches of mathematics as well as other disciplines, including parts of computer science. This alone makes it worth exploring in an introductory study of Discrete Mathematics

Pyrolysed almond shells used as electrodes in microbial electrolysis cell

9 p.The large cost of components used in microbial electrolysis cell (MEC) reactors represents an important limitation that is delaying the commercial implementation of this technology. In this work, we explore the feasibility of using pyrolysed almond shells (PAS) as a material for producing low-cost anodes for use in MEC systems. This was done by comparing the microbial populations that developed on the surface of PAS bioanodes with those present on the carbon felt (CF) bioanodes traditionally used in MECs. Raw almond shells were pyrolysed at three different temperatures, obtaining the best conductive material at the highest temperature (1000 °C). The behaviour of this material was then verified using a single-chamber cell. Subsequently, the main test was carried out using two-chamber cells and the microbial populations extant on each of the bioanodes were analysed. High-throughput sequencing of the 16S rRNA gene for eubacterial populations was carried out in order to compare the microbial communities attached to each type of electrode. The microbial populations on each electrode were also quantified by real-time polymerase chain reaction (realtime PCR) to determine the amount of bacteria capable of growing on the electrodes’surface. The results indicated that the newly developed PAS bioanodes possess a biofilm similar to those found on the surface of traditional CF electrodes. This research was possible thanks to the financial support of the Junta de Castilla y León, and was financed by European Regional Development Funds (LE320P18). C. B. thanks the Spanish Ministerio de Educación, Cultura y Deporte for support in the form of an FPI fellowship grant (Ref #: BES-2016-078329)

Effects of cognitive-behavioral programs for criminal offenders

Cognitive-behavioral therapy (CBT) is among the more promising rehabilitative treatments for criminal offenders. Reviews of the comparative effectiveness of different treatment approaches have generally ranked it in the top tier with regard to effects on recidivism (e.g., Andrews et al., 1990; Lipsey & Wilson, 1998). It has a well-developed theoretical basis that explicitly targets “criminal thinking” as a contributing factor to deviant behavior (Beck, 1999; Walters, 1990; Yochelson & Samenow, 1976). And, it can be adapted to a range of juvenile and adult offenders, delivered in institutional or community settings by mental health specialists or paraprofessionals, and administered as part of a multifaceted program or as a stand-alone intervention. Meta-analysis has consistently indicated that CBT, on average, has significant positive effects on recidivism. However, there is also significant variation across studies in the size of those treatment effects. Identification of the moderator variables that describe the study characteristics associated with larger and smaller effects can further develop our understanding of the effectiveness of CBT with offenders. Of particular importance is the role such moderator analysis can play in ascertaining which variants of CBT are most effective. The objective of this systematic review is to examine the relationships of selected moderator variables to the effects of CBT on the recidivism of general offender populations

Hydrothermal deposition of CdS on vertically aligned ZnO nanorods for photoelectrochemical solar cell application

CdS/ZnO nanorods composite nanofilms were successfully synthesized via hydrothermal method on indium doped tin oxide glass substrates. Sequentially deposited CdS formed cauliflower like nanostructures on vertically aligned ZnO nanorods. The morphological, compositional, structural and optical properties of the films were characterized by field emission scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction and ultraviolet–visible spectroscopy. Photoelectrochemical conversion efficiencies were evaluated by photocurrent measurements in a mixture of Na2S and Na2SO3 akaline aqueous solution. The amount of deposit, as well as the diameter and crystallinity of the CdS cauliflower were found to increase with growth time. CdS/ZnO nanorods composite exhibited greater photocurrent response than ZnO nanorod arrays. Besides, the composite film with 90 min of growth duration displayed the highest photocurrent density which is nearly four times greater than plain ZnO nanorods under the illumination of halogen light. The result exhibited remarkable photoconversion efficiency (η) of 1.92 %

A speedup technique for dynamic graphs using partitioning strategy and multithreaded approach

There are many pre-processing-based speedup techniques for shortest path problems that are available in the literature. These techniques have an increased demand because of large datasets in such applications such as roadmaps, web search engines and mobile data sets. Pre-processing for the Time-Dependent Shortest Path Problem is still a demanding process that involves graph or network partitioning strategy. Efficient pre-processing of graphs or networks reduces the shortest path computation time while parallelizing the pre-processing phase improves the speedup of the system. In this paper, a speedup technique called Recursive Spectral Bisection (RSB) combined with the Elliptic Convolution of the shortest path method is proposed for dynamic Time-Dependent networks. The same method has been parallelized, and the results are tested on three types of graphs. It is observed that the Time-Dependent RSB combined with the Elliptic Convolution of the shortest path method has no update time, and the Query Performance Loss (QPL) is reduced in planar and road networks compared to random networks. In road networks, the proposed method achieves an average speedup in a QPL of 140. The use of the Parallel speedup technique results in an average speedup in a QPL of more than 1 in the planar and road networks

Role of NaOH concentration on synthesis and characterization of β-V2O5 nanorods by solvothermal method

In this work, synthesis of β-V2O5 nanorods by solvothermal method was adopted at optimum experimental conditions by varying the concentration of NaOH as 0.5M, 1M, 1.5M and 2M. The obtained products were characterization by following techniques, XRD, RAMAN, FTIR, and FESEM. The XRD results reveal the formation of β-V2O5 nanorods and its crystalline nature was confirmed by its lattice parameters. The Raman analysis shows a peak at 485, 770 and 998 cm−1 corresponds to the vibration of O-V-O bonds. Similarly the FITR peaks appeared at the 530 and 786 cm−1 can be attributed to the symmetric stretching of Metal Oxide (V-O). The morphology and its structure of β-V2O5 nanorods can be analysized by the FESEM techniques and its images shows the formation of β-V2O5 nanorods with different dimensions. The role of concentration of NaOH can be studied by comparing the FESEM micrographs. It is clearly evident from FESEM images as the concentration of NaOH increases from 0.5 M to 2M, the shape and size of the change rapidly and the surface effect results in the mesoporous features on the surface of nanorods. Its note worthy as the concentration of NaOH increases results in the flattening of nanorods could be observed due more of interaction of NaOH precursor solution.Published versio

Hydrothermal synthesis and electrochemical properties of ZnCo2O4 microspheres

Zinc cobalt oxide (ZnCo2O4) microspheres are prepared at three different hydrothermal process temperatures (100 °C, 130 °C, and 160 °C) assisted with urea. XRD studies reveal the spinel face-centered cubic (Fd3m) structure of ZnCo2O4 microspheres. The optical and vibrational properties of the product are characterized by photoluminescence and FTIR studies. The strong nearband edge emission peak observed at 392 nm corresponds to the direct recombination of the exciton-exciton collision process for all three synthesized products; SEM analysis reveals the complete growth stage of spherical ZnCo2O4 microspheres at three different temperatures. The electrochemical properties of synthesized ZnCo2O4 microspheres are analyzed by cyclic voltammetry, electroimpedance spectroscopy, and galvanostatic charging and discharging studies. ZnCo2O4 microspheres (SH3–160 °C) exhibit the superior specific capacitance of 500 F/g at 0.75 A/g current density and retain their specific capacitance of 80% at current density 2 A/g. ZnCo2O4 microspheres (SH3–160 °C) may be considered as a good candidate as electrode in supercapacitor applications.This work was supported by UGC Start-Up Research Grant No. F.30-326/2016 (BSR)