Performance analysis of a novel eco‐friendly internal combustion engine cycle

The Miller cycle applications have been performed to diminish NO_x released from internal combustion engines (ICEs), in recent years. The Miller cycle provides decreased compression ratio and enhanced expansion ratio; hereby, maximum in‐cylinder combustion temperatures diminish, and NO_x formations slow down remarkably. Another less‐known method is Takemura cycle application, which provides heat addition into engine cylinder at constant combustion temperatures. In this study, a novel cycle including the Miller cycle and the Takemura cycle has been developed by using novel numerical models and computing methods with seven processes and a novel way to decrease NO_x emissions at higher levels compared with the single applications of known cycles. A comprehensive performance examination of the proposed cycle engine in terms of performance characteristics such as effective power (EFP), effective power density (EFPD), exergy destruction (X), exergy efficiency (ε), and ecological coefficient of performance (ECOP) has been conducted. The impacts of engine operating and design parameters on the performance characteristics have been computationally examined. Furthermore, irreversibilities depending on incomplete combustion loss (INCL), exhaust output loss (EXOL), heat transfer loss (HTRL), and friction loss (FRL) have been considered in the performance simulations. The minimum exergy destruction and maximum performance specifications have been observed with 30 of the compression ratio. Maximum effective power values have been obtained at range between 1 and 1.2 of equivalence ratio. The optimum range for exergy efficiency is between 0.8 and 1 of equivalence ratio. Increasing engine speed has provided enhancing effective power. However, an optimum range has been found for the exergy efficiency that is interval of 3000 to 4000 rpm. The results obtained can be assessed by researchers studying on modeling of the engine systems and designs.     

Biometric identification using fingertip electrocardiogram signals

In this research work, we present a newly fingertip electrocardiogram (ECG) data acquisition device capable of recording the lead-1 ECG signal through the right- and left-hand thumb fingers. The proposed device is high-sensitive, dry-contact, portable, user-friendly, inexpensive, and does not require using conventional components which are cumbersome and irritating such as wet adhesive Ag/AgCl electrodes. One of the other advantages of this device is to make it possible to record and use the lead-1 ECG signal easily in any condition and anywhere incorporating with any platform to use for advanced applications such as biometric recognition and clinical diagnostics. Furthermore, we proposed a biometric identification method based on combining autocorrelation and discrete cosine transform-based features, cepstral features, and QRS beat information. The proposed method was evaluated on three fingertip ECG signal databases recorded by utilizing the proposed device. The experimental results demonstrate that the proposed biometric identification method achieves person recognition rate values of 100% (30 out of 30), 100\(\%\) (45 out of 45), and 98.33\(\%\) (59 out of 60) for 30, 45, and 60 subjects, respectively.     

Synthesis and properties of radiation‐induced acrylamide–acrylic acid hydrogels

Acrylamide (AAm)/acrylic acid (AAc) hydrogels in the cylindirical form were prepared by γ‐irradiating binary systems of AAm/AAc with 2.6–20.0 kGy γ‐rays. The effect of the dose and relative amounts of AAc and pH on the swelling properties, diffusion behavior of water, diffusion coefficients, and network properties of hydrogel systems was investigated. The swelling capacities of AAm/AAc hydrogels were in the range of 1000–3000%, while poly(acrylamide) (PAAm) hydrogels swelled in the range of 450–700%. Water diffusion into hydrogels was found to be non‐Fickian‐type diffusion. Diffusion coefficients of AAm/AAc hydrogels were found between 0.79 × 10^?5 and 2.78 × 10^?5 cm² min^?1. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3570–3580, 2002     

The necessity of reexamining previous life prediction analyses ofsolder joints in electronic packages

There are several different constitutive relations for describing the creep behavior of solder to predict the fatigue life of a solder joint. The differences among these constitutive relations for fatigue life prediction of electronic packages are unknown because analysts using finite element programs such as ABAQUS or ANSI'S are generally limited to specific built-in material models. The objective of this study is to implement a procedure that allows the use of various creep models in the analysis of electronic packages using ANSYS. Special user routines are developed so the user can incorporate virtually any creep relation and determine the inelastic strain energy density developed in the three-dimensional solid elements. Comparisons are performed for the modified creep routines and the viscoplastic formulation of Anand's model in ANSYS. It is found that the scheme used by ANSYS to determine plastic work density is incorrect and will be remedied in a future release. The implications of this revision to ANSYS are critical because a change in scheme will make comparisons with past studies and analyses difficult. The value of the empirical parameters based on previous analyses, which are widely used in the prediction of package fatigue life, will have to be reexamined     

Synthesis and characterization of novel comb-type amphiphilic graft copolymers containing polypropylene and polyethylene glycol

Amphiphilic comb-type graft copolymers containing polypropylene (PP) and polyethylene glycol (PEG) have been prepared. Polypropylene-g-polyethylene glycol comb-type thermoplastic amphiphilic copolymers were synthesized by the reaction between chlorinated polypropylene and polyethylene glycol in the presence of a base via a “grafting to” technique. A series of graft copolymers containing PEGs with molecular weights of 600 and 2,000 Da in the range of 4–34 mol% PEG were obtained. The amphiphilic graft copolymers with PEG segments in range between 20 and 30 mol% PEG displayed good film properties with elongation at break 275–440%. The hydrophilicity of the amphiphilic copolymers increases with the increasing PEG content in the copolymer while the mechanical properties decrease. Therefore, PP-g-PEG2000 with PEG contents in the range of 20–30 mol% PEG should be useful for medical and industrial applications where good film properties are needed.     

Glucose recognition capabilities of hydroxyethyl methacrylate‐based hydrogels containing poly(ethylene glycol) chains

A configurational biomimetic imprinting technique was used to prepare recognition sites for glucose in copolymers of 2‐hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA) prepared with crosslinking agents containing poly(ethylene glycol) (PEG). We report on the structure, diffusive, and recognition characteristics of these gels, the effect of the type and ratio of crosslinking agent, as well as the template/comonomer ratios on glucose binding ability. The highest equilibrium glucose binding was found as 2.67 mg/g dry polymer when PEG monomethacrylate (PEGMMA) was used in combination with tetra ethylene glycol dimethacrylate (TEGDMA) (50%) as a crosslinking agent. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 103: 432–441, 2007     

Synthesis and room temperature coating of nano ZrB2 on copper using mechanical roll-milling

In this study, ZrB₂ was prepared from ZrOCl₂.8H₂O, H₃BO₃ and citric acid by using the gel method. The gel was dried at 400 °C and then it was calcined at 1500 °C. The prepared 0.5–1 μm ZrB₂ powder was encapsulated into the Cu tube. For the purpose of coating ZrB₂ on Cu metal, the roll-milling of ZrB₂ particles inside the cylindrical Cu tube has been performed at room temperature. The prepared ZrB₂ coating on Cu was analyzed by using FE-SEM, EDS, XRD, electrical resistivity and CV measurements. The final ZrB₂ particle size on the surface of the coating layer was below 100 nm, and the coating thicknesses were about 15–20 μm. The long nanofiber like ZrB₂ structures was observed. The coating of nano ZrB₂ on Cu was achieved by using this novel roll-milling process which is an environmental friendly, low cost and practical technique.     

Cross-cultural interface design strategy

This paper addresses the emerging need for an integration of the cultural and social factors of metaphors into interface design, by creating cultural models within the context of indigenous users. Current theoretical and empirical work is reviewed that uses existing cultural models. Finally, an investigative strategic model is proposed for research in this field that incorporates all the important components of cultural contexts of metaphors in interface design.