Integrating accounting and multiplicative calculus: an effective estimation of learning curve

Numerical interpolation methods are essential for the estimation of nonlinear functions and they have a wide range of applications in economics and accounting. In this regard, the idea of using interpolation methods based on multiplicative calculus for suitable accounting problems is self-evident. The purpose of this study, therefore, is to develop a way to better estimate the learning curve, which is an exponentially decreasing function, based on multiplicative Lagrange interpolation. The results of this study show that the proposed multiplicative method of learning curve provides more accurate estimates of labour costs when compared to the conventional methods. This is because the exponential functions are linear in multiplicative calculus. Furthermore, the results reveal that using the proposed method enables cost and managerial accountants to better calculate both cost of unused capacity and product cost in a cumulative production represented by a nonlinear function. The results of this study are also expected to help researchers, practitioners, economists, business managers, and cost and managerial accountants to understand how to construct a multiplicative based learning curve to improve such decisions as pricing, profit planning, capacity management, and budgeting.     

Synthesis and crystal structure of 1-benzyl-2-(4-benzyloxyphenyl)-5,6-dichloro-1<Emphasis Type="Italic">H</Emphasis>-benzimidazole

In this study 1-benzyl-2-(4-benzyloxyphenyl)-5,6-dichloro-1H-benzimidazole, II, was synthesised. Elemental analyses, 1H-NMR, and single-crystal structure determination have been carried out. The benzimidazole ring system is planar as expected. The molecules of II are arranged in rows running parallel to the b-axis with the molecules in adjacent rows inverted.     

Thermal analysis of a white calcium bentonite

A white calcium bentonite (CaB) taken from Çaml?dere (Ankara, Turkey) region was heated at various temperatures between 100 and 1100 °C for 2 h. The mineralogy of the CaB was determined as calcium smectite (CaS), metahalloysite (MH), opal-A (OA), opal-CT (OCT), quartz (Q), feldspar (F), and calcite (C) using the X-ray diffraction patterns of the natural CaB and its heated samples. Besides the XRD patterns, the thermogravimetry, differential thermal analysis, and low-temperature nitrogen adsorption (N₂-AD) data show that the CaS lose adsorbed and hydration water up to 300 °C, dehydroxylation takes place between 300 and 750 °C, and then the 2:1 layer structure completely collapses above 900 °C. The activation energies for the dehydration and dehydroxylation were calculated as 7636 and 48838 J mol^?1, respectively, from the TG data using Coats and Redfern method. The specific surface area (S) and specific micro–mesopore volume (V) obtained from N₂-AD data were 44 m² g^?1 and 0.100 cm³ g^?1 for the natural CaB. S and V reach their maxima of 105 m² g^?1 and 0.155 cm³ g^?1, respectively, at 300 °C, remain approximately constant as the temperature increases up to 700 °C and then decrease almost in parallel with each other, reaching their minima at 900 °C. This indicates that the S and V values increase gradually during dehydration and dehydroxylation of the CaS.     

Voltammetric and spectroscopic studies on the interaction of anti-cancer herbal drug rutin with an anti-tuberculosis agent rifampicin

In this paper, the interaction of rutin (Rt) with rifampicin (RIF) has been investigated using voltammetric and spectroscopic techniques. With the addition of RIF into the Rt solution, both the reduction and oxidation currents of rutin decrease with few changes in the peak potentials and no new peaks appeared. The binding of Rt with RIF forms a kind of supramolecular complex Rt-RIF, which is electrochemically non-active. The experimental data showed that the formation of supramolecular complex is due to the electrostatic attraction of Rt with RIF. The binding reaction resulted in the decrease of the concentration of free Rt in the solution, and the decrease of the cathodic peak current of Rt. The stoichiometry of the Rt-RIF biocomplex was determinated to be 1: 1 by means of voltammetric data. The effect of pH on the binding reaction has been also studied. Based on the peak current values of Rt in the presence and absence of RIF, the binding constants of Rt-RIF at pHs 4, 7 and 9 were calculated as 0.72 × 10⁴ M⁻¹, 1.28 × 10⁴ M⁻¹ and 0.19 × 10⁴ M⁻¹, respectively. The experimental results indicate that there is a strength interaction between Rt and RIF in neutral pH. This binding reaction was supported by UV-Vis. and IR spectroscopy techniques.     

Copper(II)-pyrazine-2,3-dicarboxylate Coordination Polymer with Monoethanolamine, [Cu(μ<Subscript>3</Subscript>-pzdc)(mea)]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>

Abstract  

A novel Cu(II)-pyrazine-2,3-dicarboxylate complex with monoethanolamine ligand (mea), [Cu(μ₃-pzdc)(mea)]_n (1), has been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structure of polynuclear complex has been determined by the single crystal X-ray diffraction technique. The pyrazine-2,3-dicarboxylate dianion exhibits tetradentate-μ₃ bridging ligand through three carboxylate oxygens and one nitrogen atom. The complex contains two copper(II) ions that exhibit two different coordination environments with two mea, two pzdc ligands, respectively. The Cu1(II) ion is coordinated by two carboxylate oxygen atoms, two N atoms and two O atoms of symmetry related carboxylate group, forming a distorted octahedral geometry, while Cu2(II) ion is coordinated by two bidentate mea ligands and remaining two coordination sites of distorted octahedral geometry are occupied by two carboxylate oxygen atoms of neighboring Cu1 molecule. Thermal analysis property and thermal decomposition mechanism of complex have been investigated by using thermal analyses techniques (TG, DTG and DTA).     

An evolutionary approach for tuning parametric Esau and Williams heuristics

Owing to its inherent difficulty, many heuristic solution methods have been proposed for the capacitated minimum spanning tree problem. On the basis of recent developments, it is clear that the best metaheuristic implementations outperform classical heuristics. Unfortunately, they require long computing times and may not be very easy to implement, which explains the popularity of the Esau and Williams heuristic in practice, and the motivation behind its enhancements. Some of these enhancements involve parameters and their accuracy becomes nearly competitive with the best metaheuristics when they are tuned properly, which is usually done using a grid search within given search intervals for the parameters. In this work, we propose a genetic algorithm parameter setting procedure. Computational results show that the new method is even more accurate than an enumerative approach, and much more efficient.     

Synthesis and characterisation of highly fluorescent core–shell nanoparticles based on Alexa dyes

Current and future developments in the emerging field of nanobiotechnology are closely linked to the rational design of novel fluorescent nanomaterials, e.g. for biosensing and imaging applications. Here, the synthesis of bright near infrared (NIR)-emissive nanoparticles based on the grafting of silica nanoparticles (SNPs) with 3-aminopropyl triethoxysilane (APTES) followed by covalent attachment of Alexa dyes and their subsequent shielding by an additional silica shell are presented. These nanoparticles were investigated by dynamic light scattering (DLS), transmission electron microscopy (TEM) and fluorescence spectroscopy. TEM studies revealed the monodispersity of the initially prepared and fluorophore-labelled silica particles and the subsequent formation of raspberry-like structures after addition of a silica precursor. Measurements of absolute fluorescence quantum yields of these scattering particle suspensions with an integrating sphere setup demonstrated the influence of dye labelling density-dependent fluorophore aggregation on the signaling behaviour of such nanoparticles.     

Optimal Keyword Bids in Search-Based Advertising with Stochastic Advertisement Positions

US expenditures on search-based advertising exceeded $12 billion in 2010. Advertisers bid for keywords, where bid price determines ad placement, affecting click-through and conversion rates. Advertisers must select keywords, allocating each a proportion of their fixed daily budget. In this paper, we construct a stochastic model for the selection and allocation process. We provide analytical results for the single-keyword problem and examine the multiple-keyword problem numerically. We investigate trade-offs between keywords given varying levels of risk and return. We show the implications of enforcing a probabilistic budget constraint. Our paper provides a critical analysis of the advertiser’s problem that may guide future research.     

Performance evaluation of a G-6-PD assay employing an adapted error grid graph

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is one of the most common genetic diseases, characterized by neonatal jaundice or hemolysis during adulthood. Neonatal screening for this disease has been established in many countries in the Mediterranean and Middle East region but not yet in Turkey. The performance of a new fully quantitative G-6-PD kit employing hemoglobin normalization was statistically evaluated and the cut-off points and reference values for the Izmir region (Aegean coast of Turkey) were established, including a long term performance evaluation of the method. Statistical acceptance of the bias and variation were also clinically evaluated using new tools, such as the Parkes error grid graph. The kit used is particularly suitable for use with Guthrie cards as well as with whole blood samples. We report here on the results of the evaluation, emphasizing the methodology we used for it.Presented at the 9th Conference on Quality in the Spotlight, 18–19 March 2004, Antwerp, Belgium.