Evaluation of lubricant condition and engine health based on soft computing methods

Neural Computing and Applications - Evaluating the condition of the lubricant plays an influential role in the maintenance engineering of mechanical systems. This study has several objectives and...     

A digital frequency independent phase meter

A digital, frequency-independent phase meter is described. It makes use of pulses derived from the multiplication of the frequency of the reference input signal as its clock pulses instead of conventional crystal controlled clock generators. Advantages of the meter include simplicity and the elimination of gating error. The main source of error for this circuit is harmonic distortion of the input signals     

A study of Cr(VI) and NH4+adsorption using greensand (glauconite) as a low‐cost adsorbent from aqueous solutions

This paper investigates the removal of Cr(VI) and NH⁴⁺ from aqueous solutions using greensand (glauconite). The effects of adsorbent dosage, contact time, initial Cr(VI) and NH⁴⁺ concentrations, and pH were investigated in batch experiments. The results show that these parameters influenced Cr(VI) and NH⁴⁺ removal using glauconite considerably. Pseudo‐first‐order, pseudo‐second‐order and intraparticle diffusion kinetic models were applied to explain the kinetic data, and the pseudo‐second‐order model achieved good agreement. The equilibrium isotherm data are coordinated with the Freundlich, Langmuir models, Temkin and Dubinin–Radushkevich; the Freundlich model proved most best suitable. The removal efficiency of Cr(VI) and NH₄⁺ were 12.21 mg/g (54% at pH 3) and 19.24 mg/g (77.08% at pH 7). All in all, the results showed that the adsorption process on glauconite could be used as an effective method for removing Cr(VI) and NH⁴⁺ from aqueous solutions.     

A high resolution digital frequency meter for low frequencies

A digital frequency meter using frequency multiplication is described. It can be used in utility power system control centers and other low-frequency applications where resolutions of the order of 1/100 Hz and almost instantaneous readouts are essential. Possible improvements of the circuit are suggested     

Effect of Notch Location on Fatigue Life Prediction of Strength Mismatched HSLA Steel Weldments

Welding of high strength low alloy steels (HSLA) involves usage of low, even and high strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler material. In the present investigation, the fatigue crack growth behaviour of weld metal (WM) and heat affected zone (HAZ) regions of under matched (UM), equal matched (EM) and over matched (OM) joints has been studied. The base material used in this investigation is HSLA-80 steel of weldable grade. Shielded metal arc welding (SMAW) process has been used to fabricate the butt joints. Centre cracked tension (CCT) specimen has been used to evaluate the fatigue crack growth behaviour of the welded joints. Fatigue crack growth experiments have been conducted using servo hydraulic controlled fatigue testing machine at constant amplitude loading (R=0). A method has been proposed to predict the fatigue life of HSLA steel welds using fracture mechanics approach by incorporatin     

A Simulation Model for Life Cycle Project Management

This paper puts forward a simulation model specifically designed for holistic evaluation of project functionality within a life cycle project management framework. The authors describe a methodology for development of the aforementioned tool, referred to as a dynamic simulation modeling system (DSMS). The DSMS is geared toward modeling of service and manufacturing processes with hierarchical and modular modeling methodology; however, the underlying philosophy can be adopted for modeling any generic system. The enhanced modeling features and logical division of large systems into small process components and their internal linkage are the key contributions of this work. The aim of this development is to apply the simulation technique in order to evaluate the overall project functionalities from the dynamic business perspective. A set of business objective functions (i.e., life cycle objective function [LCOF]) has been employed as a basis for decision making throughout the project's life. Object-oriented programming language with the object-oriented database technology facilitates the necessary model capability. A brief case study has been used to demonstrate and discuss the model capability.     

Synthesis and Characterization of New Poly(ether-amide-imide)/Amino-Functionalized Fe3O4 Nanocomposites

New poly(amide-imide)/amino functionalized Fe₃O₄ nanocomposites were successfully fabricated through solution intercalation technique. A poly(amide-imide) derived from an imide-containing diacid and ether linkage diamine was synthesized and characterized. Aiming to have better compatibility, the hydrophilic nature of Fe₃O₄@SiO₂ was changed into organophilic using N-[3-(trimethoxysilyl)propyl]ethylenediamine. The amino-functionalized Fe₃O₄ showed well dispersion in the poly(amide-imide) matrix. Thermal gravimetric analysis results indicated that char yields of the nanocomposites were improved. Microscale combustion calorimetry results showed that poly(amide-imide) had good flame retardancy and amino-functionalized Fe₃O₄ has further improved this property of poly(amide-imide).     

J. Cosmet. Sci., 59, 385–398 (September/October 2008)Evaluation of liposomal and conventional formulations of octyl methoxycinnamate on human percutaneous absorption using the stripping method

The objective of this study was to determine the influence of vehicles on the penetration of octyl methoxycinnamate (OMC), as a UV absorber, to the stratum corneum by the stripping method. The experimental formulations consisted of a conventional o/w emulsion and multilamellar and small unilamellar liposomes (MLVs and SUVs) containing OMC. MLVs containing OMC were prepared by the fusion method and then converted to SUVs by probe sonication. Various formulations were then applied onto the midvolar forearms of six volunteers at a dose of 2 mg cm^-2. After determined timepoints, the stripping method was conducted whereby 22 tape strips were applied and subsequently divided into different stripping groups. The sunscreen agent was assessed by HPLC while the SPF (sun protection factor) of the formulations was determined in human volunteers in accordance with the Australian standard. Overall the results indicate that skin accumulation of OMC in MLVs was significantly greater than in the o/w emulsion and SUVs. Furthermore, SUV's penetration into the deeper skin layers was significantly greater than MLV's and that of a conventional o/w emulsion. Also, higher amounts of OMC were recovered from the upper layers of the stratum corneum than from the deeper layers in all the formulations tested. Finally, the SPF of the liposomes containing OMC was slightly greater than that of the control lotions at a similar concentration of OMC. In conclusion, the result of this study indicates that an MLV prepared by the fusion method could be a better vehicle for OMC as a sunscreen since it has a slightly better SPF compared to a conventional formulation and more remains in the stratum corneum, reducing its penetration to the deeper layers.
Address all correspondence to M. R. Jaafari.     

Synthesis of a Model for Life-Cycle Project Management

The focus of this article is on life-cycle objective–based project management models in general. The model has been designed (1) to facilitate employment of life-cycle objective–based project management approaches and (2) to support concurrent engineering and construction, thus promoting greater integration of total processes under which projects are proposed and implemented. In order to synthesize the functions designed in the model, we undertook a detailed case study of a large capital project. This case study has been documented in separate articles; only the results of the study will be presented in this article. While this field research shed light on the actual needs and requirements, the design of the functions was approached from first principles. They incorporate the basic shift from the traditional objectives of cost, time, and quality to life-cycle objective functions, such as return on investment, facility operability, and life-cycle integration. This article describes the fundamental philosophy and framework for the development of life-cycle project management in general and contrasts this with the traditional project management models.     

Developing a Model for Decision-Makers in Dynamic Modeling of Urban Water System Management

Water managers may modify many components of urban water systems to minimize water shortage. Since each modification activity has its own positive and negative effects, it is necessary to define an appropriate procedure to predict the consequences of each action. As the parameters of urban water supply and demand system have internal relationships in the time domain, a dynamic model is needed to forecast the result of changes and select the best modification activity. Here the Vensim® is applied as a modeling tool to choose the most effective water management activities in Tehran province. It has been found that the annual increase rate of water tariff by 16.4% and assigning 4.5% of revenue on reducing non-revenue water may be the most effective demand management activity to reduce water shortage in Tehran province. It has also been revealed that, even by implementing the most effective demand management activities in Tehran, the amount of required water in the next 10 years is more than the sustainable capacity of its resources and activities like seawater desalination are inevitable to prevent unsustainable use of water sources.