Preparation,characterization, and optical properties of a chitosan–anthraldehyde crosslinkable film

A novel chitosan–anthraldehyde derivative film was prepared by the reaction of 79% deacetylated chitosan with 9‐anthraldehyde with a hydrogel by a solution casting method. The prepared chitosan derivative film was confirmed by ultraviolet–visible absorption spectroscopy of the absorption peak at 266 nm due to the presence of an anthracene ring. The crosslinking reaction showed significant changes in the Fourier transform infrared spectrum of the chitosan derivative film. The characteristic peak of CH?N stretching bands at 1610 cm^?1 confirmed the formation of a Schiff base after the reaction of chitosan with 9‐anthraldehyde. The film was evaluated by X‐ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, and second harmonic generation (SHG). The nature of the crystallinity of the chitosan derivative from X‐ray diffraction analysis confirmed that the film may have had nonlinear optical properties. The chitosan derivative showed a redshifted emission maximum because of the electron‐rich polymer main chain. No reabsorption of the second harmonic signal and no resonance enhancements were noticed during the SHG study; this indicated that the chitosan derivative possessed SHG ability. Overall, the chitosan derivative film opens new perspectives for optical material for biomedical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Water repellent ZnO nanowire arrays synthesized by simple solvothermal technique

The authors report on the water repellent properties of quasialigned zinc oxide (ZnO) nanowire arrays grown by low-temperature solvothermal technique. The uniform and dense ZnO nanowires of average diameter ∼ 75 nm have been found to have hexagonal wurtzite type structure. The as synthesized ZnO nanowire surfaces have hydrophilic nature with a water contact angle of 73° ± 3°. The superhydrophobic behavior with a water contact angle of 145° ± 3° of the nanowire arrays has been realized due to the reduction of surface free energy after being coated with an octadecyltrichlorosilane (OTS) monolayer. This work may be of huge importance from the viewpoint of both the understanding of the mechanisms involved and industrial applications.     

ImAge: an extensible agent-based architecture for image retrieval

We present an open and extensible architecture, ImAge, for content-based image retrieval in a distributed environment. The architecture proposes the use of system components with standard public interfaces for implementing retrieval functionality. The standardization of the components and their encapsulation in autonomous software agents result in functional stratification and easy extensibility. Collaboration of the independent retrieval resources in ImAge results in enhanced system capability. Reuse of existing retrieval resources is achieved by encapsulating them in agents with standard interfaces. The addition of independent agents with domain knowledege adds the capability of processing conceptual queries, while reusing the existing system components for feature-based retrieval. A communication protocol allows the declaration of the capabilities of the system components and negotiations for optimal resource selection for solving a retrieval problem. The use of mobile agents alleviates network bottlenecks. This paper describes a prototype implementation that validates the architecture.     

Mathematical modeling of moving heat source shape for submerged arc welding process

An attempt is made in this paper to find out the analytical solution of the thermal field induced in a semi-infinite body by a moving heat source with Gaussian distribution by selecting appropriate inside volume for submerged arc welding process. Three different types of heat source shapes in the form of oval, double ellipsoidal, and conical forms were considered and compared with the experimental result. The study shows that for heat input of submerged arc welding process, the best suitable heat source shape is in the form of an oval. The study also shows two alternate ways of predicting the size of the heat-affected zone.     

Perception of safety of cyclists in Dublin City

In recent years, cycling has been recognized and is being promoted as a sustainable mode of travel. The perception of cycling as an unsafe mode of travel is a significant obstacle in increasing the mode share of bicycles in a city. Hence, it is important to identify and analyze the factors which influence the safety experiences of the cyclists in an urban signalized multi-modal transportation network. Previous researches in the area of perceived safety of cyclists primarily considered the influence of network infrastructure and operation specific variables and are often limited to specific locations within the network. This study explores the factors that are expected to be important in influencing the perception of safety among cyclists but were never studied in the past. These factors include the safety behavior of existing cyclists, the users of other travel modes and their attitude toward cyclists, facilities and network infrastructures applicable to cycling as well as to other modes in all parts of an urban transportation network. A survey of existing cyclists in Dublin City was conducted to gain an insight into the different aspects related to the safety experience of cyclists. Ordered Logistic Regression (OLR) and Principal Component Analysis (PCA) were used in the analysis of survey responses. This study has revealed that respondents perceive cycling as less safe than driving in Dublin City. The new findings have shown that the compliance of cyclists with the rules of the road increase their safety experience, while the reckless and careless attitudes of drivers are exceptionally detrimental to their perceived safety. The policy implications of the results of analysis are discussed with the intention of building on the reputation of cycling as a viable mode of transportation among all network users.     

Generalized Thermoelastic Problem of a Spherically Isotropic Infinite Elastic Medium Containing a Spherical Cavity

This paper is concerned with the determination of thermoelastic stresses and temperature in a spherically isotropic infinite elastic medium having a spherical cavity in the context of the linear theory of generalized thermoelasticity with two relaxation time parameters (Green and Lindsay theory). The surface of the cavity is stress free and is subjected to a thermal shock. The basic equations have been written in the form of a vector-matrix differential equation in the Laplace transform domain, which is then solved by the eigenvalue approach. The numerical inversion of the transforms is carried out using the Bellman method. The stresses and temperature are computed and presented graphically. A comparison with isotropic body has also been studied.     

A farm‐to‐fork model to evaluate the level of polyacetylenes in processed carrots

Naturally occurring aliphatic C₁₇ polyacetylene compounds [falcarinol (FaOH), falcarindiol (FaDOH) and falcarindiol‐3‐acetate (FaDOAc)] in carrots are known for their bioactivity and health benefits. This study assesses the impact of pre‐ and postharvest processes (including food processing stages) on the level of polyacetylenes and evaluates subsequent human exposure using Monte Carlo simulation techniques. The model includes data inputs from both experimental and published literature sources. The sensitivity analysis highlights the importance of cultivar selection and agronomic factors. The sensitivity analysis also showed that peeling, blanching and boiling time of carrots have a significant negative influence on the level of polyacetylenes with correlation coefficients of ?0.15, ?0.14 and ?0.19 for FaOH, ?0.47, ?0.23 and ?0.20 for FaDOH and ?0.29, ?0.26 and ?0.25 for FaDOAc, respectively. The scenario analysis shows the practical application of the proposed model for industrial processing of carrots. This model could facilitate food processors in optimising critical processing factors such as peeling and cutting prior to processing of carrots.     

Fractional order phase shaper design with Bode’s integral for iso-damped control system

The phase curve of an open loop system is flat in nature if the derivative of its phase with respect to frequency is zero. With a flat-phase curve, the corresponding closed loop system exhibits an iso-damped property i.e. maintains constant overshoot with the change of gain. This implies enhanced parametric robustness e.g. to variation in system gain. In the recent past, fractional order (FO) phase shapers have been proposed by contemporary researchers to achieve enhanced parametric robustness. In this paper, a simple methodology is proposed to design an appropriate FO phase shaper to achieve phase flattening in a control loop, comprising a plant controlled by a classical Proportional Integral Derivative (PID) controller. The methodology is demonstrated with MATLAB simulation of representative plants and accompanying PID controllers.