HACCP system in food trade why and how?

The purpose is to adopt the operation of HACCP to the hierarchy of the company, and to test the C CP selection mode within HACCP that excludes errors. The result is the presentation of the target hierarchy containing the HACCP system, and of the objective CCP selection method

USE OF APPROXIMATE ENGINEERING METHODS FOR SEMI-RIGID FRAME ANALYSIS

This paper gives a short summary about the possibilities of constructing more precise, but not too difficult connection models for frame analysis. It is dealing with simple methods, which can be useful tools for - either to construct envelope curves for the elastic and for the plastic behaviour separately, - or to determine the elastic - plastic response of the frame by concentrating all of non-linearities into real or pseudo connection springs, which are connecting the elastic members

Applying Heterogeneous Catalytic Reactions for Organic Chemical Syntheses

In this review the most important results achieved in the recent 12–15 years are summarized focusing on the heterogenous catalytic hydrogenations over transition metals (Pd, Pt, Ru, Rh, La), as well as the application of palladium, copper and other metals on a molecular sieve (4A) support in several organic chemical syntheses in liquid phase

Inputs and outputs of poly(ADP-ribosyl)ation: Relevance to oxidative stress

AbstractOxidative stress can cause DNA breaks which induce activation of the DNA nick sensor enzyme poly(ADP-ribose) polymerase-1 (PARP-1), part of the 17 member PARP enzyme family. PARP-1 modifies target proteins by attaching to them several NAD-derived ADP-ribose units forming poly(ADP-ribose) (PAR) polymers. PARylation controls many cellular processes while intense PARylation may also lead to cell death by various mechanisms. Here we summarize the modes of activation, inhibitors and modulators of PARP-1 and review the cellular functions regulated by the enzyme

Basins of attraction in a harmonically excited spherical bubble model

Basins of the periodic attractors of a harmonically excited single spherical gas/vapour bubble were examined numerically. As cavitation occurs in the low pressure level regions in engineering applications, the ambient pressure was set slightly below the vapour pressure. In this case the system is not strictly dissipative and the bubble can grow infinitely for sufficiently high pressure amplitudes and/or starting from large initial bubble radii, consequently, the stable bubble motion is not guaranteed. For moderate excitation pressure amplitudes the exact basins of attraction were determined via the computation of the invariant manifolds of the unstable solutions. At sufficiently large amplitudes transversal intersection of the manifolds can take place, indicating the presence of a Smale horseshoe map and the chaotic behaviour of system. The incidence of this kind of chaotic motion was predicted by the small parameter perturbation method of Melnikov

Selective Heterogeneous Catalytic Hydrogenation of Nitriles to Primary Amines

Primary amines are important intermediates, especially in the area of pharmaceutical, plastic and agrochemical industry. The heterogeneous catalytic hydrogenation of nitriles is one of the most frequently applied process for the synthesis of diverse amines. However, the control of the selectivity is a critical issue in this reaction. Over the past decade, many studies have been reported using heterogeneous transition metal catalysts for the selective reduction of nitriles to the corresponding primary amines. The type of the catalysts, especially, the chemical nature of metals in the catalysts is one of the most important factors to influence the selectivity, the reaction rate, and possibly also the reaction pathway and the deactivation of the catalyst. Thus, this review focuses on the heterogeneous transition metal catalysts and summarizes the recent developments achieved in the selective catalytic hydrogenation of nitriles to primary amines