A CUSUM-based method for monitoring simple linear profiles

In most statistical process control applications, the quality of a process or product is characterized by univariate or multivariate quality characteristics and monitored by the corresponding univariate and multivariate control charts, respectively. However, sometimes, the quality of a process or a product is better characterized by a relationship between a response variable and one or more explanatory variables. This relationship, which can be linear, nonlinear, or even a complicated model, is referred to as a profile. So far, several methods have been proposed for monitoring simple linear profiles. In this paper, a new method based on cumulative sum statistics is proposed to enhance monitoring of linear profiles in phase II. The performance of the proposed method is evaluated by average run length criterion. A comprehensive comparison is also conducted between the performance of the proposed method and the existing methods for monitoring simple linear profiles. The results show that the proposed method performs satisfactorily. In addition, the effects of reference value, sample size, and corrected sum of squares of explanatory variables on the performance of the proposed method are investigated.     

Representation and analysis of enterprise models with semantic techniques: an application to ArchiMate,e3value and business model canvas

Enterprise models assist the governance and transformation of organizations through the specification, communication and analysis of strategy, goals, processes, information, along with the underlying application and technological infrastructure. Such models cross-cut different concerns and are often conceptualized using domain-specific modelling languages. This paper explores the application of graph-based semantic techniques to specify, integrate and analyse multiple, heterogeneous enterprise models. In particular, the proposal described in this paper (1) specifies enterprise models as ontological schemas, (2) uses transformation mapping functions to integrate the ontological schemas and (3) analyses the integrated schemas with graph querying and logical inference. The proposal is evaluated through a scenario that integrates three distinct enterprise modelling languages: the business model canvas, e3value, and the business layer of the ArchiMate language. The results show, on the one hand, that the graph-based approach is able to handle the specification, integration and analysis of enterprise models represented with different modelling languages and, on the other, that the integration challenge resides in defining appropriate mapping functions between the schemas.     

Synthesis,characterization, and optimization of α‐Fe2O3/silica nanocomposites using homogenous precipitation method

The purpose of this study was to systematically synthesize and characterize the high surface area 10 wt% nanocomposites of α‐Fe₂O₃ (hematite)/silica using a simple and economically effective homogenous precipitation (HP) route via Response Surface Method combined with Central Composite Design (CCD). Accordingly, the RSM‐CCD approach including 20 experiments was designed to investigate the effects of three factors including concentration of iron chloride solution, pH and calcinations temperature on the final surface area of α‐Fe₂O₃/silica nanocomposites. The optimum surface area was 373 m²/g at the condition including iron chloride concentration of 0.018 mol/L, pH=8.95, and calcination temperature of 573°C.     

Ternary solubility of mono- and di-tert-butyl ethers of glycerol in supercritical carbon dioxide

Using a continuous flow apparatus, the ternary solubility of mono- and di-tert-butyl ethers of glycerol (MTBG and DTBG, respectively) in supercritical carbon dioxide was measured at the temperatures of 313.15, 333.15, and 348.15 K; a pressure range of 80-200 bar; and an expanded gas flow rate of 180 ± 10 mL min⁻¹ at average laboratory temperature of 300.15 K and pressure of 0.89 bar. The ternary solubility of the ethers at the constant temperatures of 333.15 and 348.15 K increased with increasing pressure up to the crossover point (i.e., 152 bar for MTBG and 170 bar for DTBG). MTBG exhibited a higher solubility than DTBG in scCO₂. The experimental data for the ternary solubility of MTBG and DTBG were correlated using the Bartle equation.     

Preparation of Nanostructured ZnO Thin Films Using Magnetron Sputtering for the Gas Sensors Applications

ZnO is one of the most promising transparent conducting oxide materials, which widely used in thin film gas sensors. In this research, the dependence of the thermal oxidation time on structural, morphological and gas sensing properties of ZnO thin films is investigated. ZnO nanostructures are synthesized by using DC magnetron sputtering for deposition of pure zinc layers on glass substrates and then thermal oxidation of deposited zinc layers to produce zinc oxide (ZnO) thin films. Obtained results from X-ray diffraction revealed that the degree of crystallinity and the average grain size of the ZnO deposited thin films enhance with increasing the thermal oxidation time. Surface topography and growth behavior of ZnO thin films have important role in optimization of gas sensing properties of these films. In this study, scanning electron microscopy and atomic force microscopy have been used to investigate the effective parameters related to the surface topography of the films. Obtained results from these analyzes revealed that the surface topography of ZnO deposited samples strongly depend on thermal oxidation time. Also the effect of thermal oxidation time on the performance of ZnO gas sensors is investigated. The results indicated that the ethanol gas sensing properties of ZnO samples improve with decreasing the size of grains.     

Study on the Hydrogenated Diamond-Like Carbon Films Synthesized by RF-PECVD from n-decane

Using a mixture of n-decane and hydrogen, diamond-like carbon thin films (DLCTFs) with high growth rate of 35?nm/min are deposited by radio frequency plasma enhanced chemical vapor deposition. We show that n-decane can be considered as a promising carbon source in DLCTF deposition. The properties of the deposited films such as structure, hydrogen content, deposition rate and refractive index are studied for 20, 50 and 100?sccm hydrogen flow rates (HFRs). It is shown that the deposition rate has a maximum of 35?nm/min for HFR?=?20?sccm and by increasing hydrogen concentration, deposition rate drops to 19?nm/min for HFR?=?100?sccm. The Raman spectra reveal that the films represent hydrogenated diamond-like carbon features. The photoluminescence background of the Raman spectra is used as a measure for hydrogen content of the films. The hydrogen content varies from 29 to 46% which yields a various amount of sp³ fraction. The results of the spectroscopic ellipsometry indicate that by increasing HFR, refractive index decreases from 2.1 to 1.9 at 632?nm. The aforementioned trends are attributed to the increase of hydrogen content in DLCTFs which is in very good agreement with enhancing of the photoluminescence background of the Raman spectra.     

Nisin‐loaded alginate‐high methoxy pectin microparticles: preparation and physicochemical characterisation

The bacteriocin nisin has been extensively used as potential natural preservative in the food industry. However, antimicrobial activity of nisin due to its binding with food components and inactivation by enzymatic degradation is reduced when it is applied in food. Encapsulation of nisin is an efficient approach to overcome the problems related to the direct application of this antimicrobial peptide in foods. In this study, nisin was encapsulated in alginate‐high methoxy pectin (HMP) microparticles, and its release studies were performed in water to determine the diffusion and the kinetic behaviour of the matrix. Results showed that the nisin content had a significant influence on encapsulation efficiency (EE), loading capacity (LC) and microparticles size. The values of EE, LC and particle mean diameter were about 47–54%, 16–21% and 57–131 μm, respectively. The nisin‐loaded microparticles showed nearly spherical structure with fold on the surface, as displayed by scanning electron micrograph. Interaction between alginate and HMP was confirmed by the changes in the intensity and wave number of the stretching vibrations of the hydroxyl and carboxyl groups in alginate‐HMP microparticles FTIR spectra. Furthermore, the addition of nisin resulted in a markedly increase in intensity of carboxylic peak at 1620 cm^?1, indicating the presence of nisin inside of the microparticles. The in vitro nisin release from these microparticles followed a sustained release profile consistent with a Fickian diffusion mechanism.