Chemical modification of metallocene‐based polyethylene–octene elastomer through solution grafting of acrylic acid and its effect on the physico‐mechanical properties

In the present work, the metallocene‐based polyethylene–octene elastomer (POE) was chemically modified by solution grafting of acrylic acid in presence of benzoyl peroxide. The relative proportions of graft and gel formation were optimized through %weight gain, Fourier Transform infrared spectroscopy, elemental analysis and proton nuclear magnetic resonance spectroscopy. The gel formation in the POE matrix was found to be the prime competitor. The effect of grafting at its maximum level on various physicomechanical properties was thoroughly investigated, using X‐ray diffraction analysis, differential scanning calorimetry, mechanical, dynamic mechanical, and thermogravimetric analysis. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Pixelated structures as a compositional medium

This paper illustrates the use of pixelated structures as a compositional medium. In this medium, compositions are constructed from parts that are very simple. Methods to generate a design vocabulary from these parts, and establish relationships between parts to construct compositions are brought together in the framework of formal languages. Finally, examples of compositions developed in this medium are presented.     

Synthesis and kinetics of ascorbic acid initiated graft copolymerized delignified cellulosic fiber

Graft copolymerization of delignified Grewia optiva fiber with methyl methacrylate (MMA) as vinyl monomer was attempted using ascorbic acid/H₂O₂ as redox initiator. Different reaction conditions affecting the grafting percentage (P_g) were optimized to get the maximum P_g (32.56%) of MMA onto delignified Grewia optiva fibers. Grafted and ungrafted fibers were subsequently subjected to evaluation of physico‐chemical properties such as swelling behavior and acid and alkali resistance. The rate expression for the grafting reaction (R_g = k [ASC]^0.12 [H₂O₂]^0.53 [MMA]^0.05) was evaluated and a suitable mechanism for grafting was suggested. The overall activation energy of the copolymerization reaction was found as 11.97 kJ mol^?1 at temperature range 25–65°C. Further, morphological and structural analysis of raw, delignified, and grafted Grewia optiva‐g‐poly(MMA) were studied by using Fourier‐transform Infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis.The tensile properties of grafted and ungrafted fiber samples were also reported. POLYM. ENG. SCI., 55:474–484, 2015. © 2014 Society of Plastics Engineers     

Development of a Liposome Based Contraceptive System for Intravaginal Administration of Progesterone

Progesterone bearing liposomes were prepared by the cast film method and characterized for various physical attributes. The liposomes could encapsulate nearly 98% of the drug. The progesterone bearing liposomes were incorporated into polyacrylamide gel and the drug content was determined. The in vitro drug dqfusion across she-goat vaginal membrane from the liposomal formulation was found to follow near zero order kinetics. The progestational activity of liposomal and control gel was assessed by monitoring the effect on the formation of corpora lutea. It was observed that both the formulations inhibit the formation of corpora lutea and thus, exhibited progestationul activity but the efsect of liposomal preparation was found to be greater and prolonged as compare to control gel.     

Studies on interfacial adhesion,tensile and thermal characteristics in blends of polystyrene/novalac resin

Specific interactions generate stability of the component parts in blends. Present work aims to elucidate intermolecular interactions in polystyrene/novolac blends by means of Infrared spectroscopic studies. It was found that strong interactions were observed at band 3095 cm^?1 assigned to aromatic C? H stretching vibrations, at band 2980 cm^?1 assigned to aliphatic C‐H stretching vibration and at band 1635 cm^?1 assigned to C?C stretch vibration of aromatic ring system. Maximum interaction was observed in blend consisting polystyrene/novolac (80:20 by parts, in this study it is blend B). Mechanical and thermal properties of the blends were also studied. Tensile strength data was found maximum in blend B. Nonisothermal method of Freeman and Carrol was used to investigate the kinetics of thermal degradation. The reactions were studied by thermogravimetry in nitrogen atmosphere. Decomposition of the blends was found in consecutive stages. The activation energies were determined for each stage of reactions. From thermal studies, blend B was found to be most stable. A degradation mechanism was suggested by compiling the reports of previous authors. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4630–4636, 2006     

Poly(adenosine diphosphoribose) polymerase in peripheral blood leukocytes from normal donors and patients with malignancies

A two-color flow cytometric technique was developed to analyze poly(ADP-ribose) polymerase (PADPRP) in different individuals as a function of different physiological or pathological conditions and to establish the basis for determining whether enzyme deficiency may predispose to degenerative or malignant disorders. Peripheral blood granulocytes were devoid of enzyme activity, whereas mononuclear cells had variable amounts. PADPRP was highest in B cells, intermediate in T cells, and lowest in monocytes. This pattern of enzyme distribution and relative enzyme content of different types of cells was remarkably constant in normal subjects. In a series of 66 normal donors there was no significant biological variation in enzyme content as a function of age, race, or sex. The mean PADPRP values in peripheral blood mononuclear cells from 81 random patient samples obtained from an ambulatory oncology clinic did not differ significantly from normal subjects. However, groups of patients with breast cancer, lymphocytic malignancies, and esophageal cancer were observed to have below normal levels for peripheral blood mononuclear cell PADPRP.     

Motor Imagery and Error Related Potential Induced Position Control of a Robotic Arm

The paper introduces an electroencephalography (EEG) driven online position control scheme for a robot arm by utilizing motor imagery to activate and error related potential (ErrP) to stop the movement of the individual links, following a fixed (pre-defined) order of link selection. The right (left) hand motor imagery is used to turn a link clockwise (counterclockwise) and foot imagery is used to move a link forward. The occurrence of ErrP here indicates that the link under motion crosses the visually fixed target position, which usually is a plane/line/point depending on the desired transition of the link across 3D planes/around 2D lines/along 2D lines respectively. The imagined task about individual link's movement is decoded by a classifier into three possible class labels:clockwise, counterclockwise and no movement in case of rotational movements and forward, backward and no movement in case of translational movements. One additional classifier is required to detect the occurrence of the ErrP signal, elicited due to visually inspired positional link error with reference to a geometrically selected target position. Wavelet coefficients and adaptive autoregressive parameters are extracted as features for motor imagery and ErrP signals respectively. Support vector machine classifiers are used to decode motor imagination and ErrP with high classification accuracy above 80%. The average time taken by the proposed scheme to decode and execute control intentions for the complete movement of three links of a robot is approximately 33 seconds. The steady-state error and peak overshoot of the proposed controller are experimentally obtained as 1.1% and 4.6% respectively.      

Systematic approach for automated determination of parting line for die-cast parts

The parting line decision for die-cast parts is a non-trivial task, which depends upon a number of factors related to the part geometry and the die-casting process requirements. This is a crucial decision which not only affects the design and manufacturing of the die-casting die but the part manufacturing as well. Normally, a die-casting die-design expert invests a lot of time, effort and resources to take this decision, which affects the part manufacturing lead time and cost. A systematic approach for automated determination of the parting line for die-cast parts is presented in this paper. Unlike the previous systems, which consider part geometric factors only, the system proposed in this paper also considers the die-casting process requirements to determine the parting line in a systematic and automated manner. Here we discuss classification of the die-cast part surfaces, identification of undercuts and protrusions, identification of parting line regions, and determination of the parting line. The system generates a number of feasible parting lines in a given parting direction after applying the die-casting process requirements. Finally, the most suitable parting line is determined from the feasible parting lines considering the industry best practices. The results obtained from the system are similar to those of the industry. The proposed system would prove to be a major step towards automation of the die-casting die design, leading to design–manufacturing integration of the die-casting process.     

Neutrosophic classifier: An extension of fuzzy classifer

Fuzzy classification has become of great interest because of its ability to utilize simple linguistically interpretable rules and has overcome the limitations of symbolic or crisp rule based classifiers. This paper introduces an extension to fuzzy classifier: a neutrosophic classifier, which would utilize neutrosophic logic for its working. Neutrosophic logic is a generalized logic that is capable of effectively handling indeterminacy, stochasticity acquisition errors that fuzzy logic cannot handle. The proposed neutrosophic classifier employs neutrosophic logic for its working and is an extension of commonly used fuzzy classifier. It is compared with the commonly used fuzzy classifiers on the following parameters: nature of membership functions, number of rules and indeterminacy in the results generated. It is proved in the paper that extended fuzzy classifier: neutrosophic classifier; optimizes the said parameters in comparison to the fuzzy counterpart. Finally the paper is concluded with justifying that neutrosophic logic though in its nascent stage still holds the potential to be experimented for further exploration in different domains.     

Temporal tracking of spectral variations

We propose a data adaptive spectral estimation algorithm which is suitable for nonstationary estimation situations. This algorithm is based on the conventional Fourier transform of the estimated autocorrelation function. The data adaptive feature is implemented into the autocorrelation function estimation. The algorithm is computationally efficient due to its recursive nature. Its frequency tracking performance is tested against another adaptive algorithm based on the frequently used least mean square algorithm (LMS) of Widrow and Hoff (1960). The two algorithms demonstrate similar performance in many situations. Computer simulations indicate that, when applied to a signal composed of two sinusoids with different power levels, the proposed algorithm tracks the lower-powered sinusoid better than the LMS algorithm.