Organochlorine pesticide residues in poultry feed,chicken muscle and eggs at a poultry farm in Punjab,India

Animals intended for human food may absorb pesticides from residues in their feed, water or during direct/indirect exposure in the course of pest control. The objective of the present investigation was to monitor organochlorine pesticide residues in poultry feed, chicken muscle and eggs at a selected poultry farm. The samples were Soxhlet extracted for 8 h in 200 mL hexane–acetone (1:1, v/v) mixture. The clean‐up of the samples was performed by silica gel column chromatography and analysis was done on a gas chromatograph equipped with an electron capture detector. The mean total hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), endosulfan sulfate and heptachlor epoxide residues were 0.65, 0.91, 0.42 and 0.02 mg kg^?1, respectively, in feed while respective values for chicken muscle were 0.11, 0.24, 0.10 and 0.07 mg kg^?1. Higher residues were encountered in eggs as compared to muscle. None of the muscle samples exceeded maximum residue limits (MRL) for organochlorine pesticides, while all egg samples had values above the MRL for HCH and heptachlor epoxide and seven egg samples exceeded MRL for DDT residues. The results indicated that poultry feed could be one of the major sources of contamination for chicken and eggs. These residues are present despite complete ban on the use of technical HCH and DDT for agricultural purposes in India. Copyright © 2005 Society of Chemical Industry     

A Passive Authentication System Based on Optical Variable Nano/Micro-Structures

A new optical authentication and security system using optical variable nano/micro-structures (OVNs) is presented. The proposed design features a passive authentication method using a simple optical system found in common fabrication facilities. The passive authentication is obtained by insertion of an OVN image directly on a processing layer or divided between multiple layers of the fabrication process. Authentic fabrication process is validated when the proper alignment (reconstructed image, for example) at the end of the fabrication is achieved. Simple proof-of-concept devices with the OVN-based authentication system are presented along with the optical images of the resulting authentication patterns.     

Design evaluation of a small high-temperature reactor for process heat applications

The high-temperature reactor is also suitable for process heat application, in particular in smaller size units. On the basis of the results of R & D and demonstration work on coal refinement some improvements for small high-temperature reactor for process heat applications are discussed. These are: increase of the gas outlet temperature, the gas inlet temperature, the decrease of the overall system pressure, and non-integration of the primary circuit components. Some of these design evaluations are based on the results of the pre-project for the extension of the AVR-reactor in Jülich to be used as a process heat plant.     

Eigensolution for large structural systems with substructures

A method for calculating natural frequencies and mode shapes of large structural systems with substructures and the subspace iteration is developed. The method uses only substructural stiffness matrices and the mass matrix for each finite element of the system. The mass matrix for the entire structure or any of its substructures need not be computed. However, efficiency of the method is improved when mass matrix for the entire structure is computed and saved in the computer core. No approximating assumptions are made. Thus, natural frequencies and mode shapes for the finite element model employed are the same with or without the substructuring algorithm. This is demonstrated by computing first ten natural frequencies and the corresponding mode shapes for an open truss helicopter tail-boom structure.     

Computational design optimization: A review and future directions

A mathematical model for design optimization of engineering systems is defined. Computational algorithms to treat the model are reviewed and their features are discussed. The attributes of a good algorithm are given. Sequential quadratic programming algorithms that generate and use the approximate Hessian of the Lagrange function to calculate the search direction are the most recent methods. They are the most reliable methods among the available ones. Several other computational aspects, such as robust implementation of algorithms, use of a knowledge base, interactive use of optimization, and use of a database and database management system, are discussed. Recent developments in the field and future directions are presented.     

Design sensitivity analysis of elastic mechanical systems

Adjoint variable methods are employed to develop efficient numerical methods of computing design derivatives of performance measures of elastic mechanical systems. Taking advantage of symmetry in finite element matrices and differential operators, a sensitivity analysis method is developed and demonstrated on a variety of static and dynamic structures and on vibration and impact absorbers. Where direct numerical comparisons are possible, the method is shown to be five to ten times faster than methods previously employed.     

The growth of gypsum crystals on barite and calcite

The kinetics of crystallization of calcium sulfate dihydrate on barite and calcite seed materials have been studied at 25°C. The grown solid phases have also been investigated by scanning electron microscopy, specific surface area measurements, and by x-ray diffraction.     

Analysis of antibiotic residues in raw and commercial milk in Punjab,India vis‐à‐vis human health risk assessment

The present study quantitatively analyzed the occurrence of antibiotic residues in 524 milk samples (492 raw milk samples from dairy farms and 32 commercial milk samples) from Punjab, India using high‐performance liquid chromatography (HPLC). Tetracyclines, sulphonamides, fluoroquinolones (commonly used in veterinary practice in Punjab), and chloramphenicol (banned in food animals in India) were targeted and analyzed using multiresidue HPLC method. Out of 492 dairy farms milk samples, 78 (16%) were found to be positive for antibiotic residues with 20 (4%) exceeded the maximum residue limits (MRLs). Among 32 commercial milk samples, 4 (12.5%) were positive for antibiotic residues with one (3.1%) sample violated the MRL. Assessment of human health risks revealed that the current levels of antibiotic residues in milk pose no significant toxicological effects on the health of consumers. However, the results highlighted an immediate need of effective strategies for prevention of nonprudent use of antibiotics in veterinary practice for safeguarding consumer's health.