Storage of chicken breast meat in paper coated with different types of hydrophobic agents

Chicken meat is well known for its high nutritional value. Its shelf life is short, due to the pronounced perishability, even under refrigeration. Paper bags are usually used as packaging materials, due to their biodegradability. The main negative aspect concerning paper is its high porosity and low moisture barrier. In this regard, it has to be coated/modified with efficient moisture barrier materials. The storage of chicken breast meat wrapped in four types of paper-based materials currently in use in Romania (RO), Italy (IT), Spain (SP) and Slovenia (SLO) is reported. RO and IT are paper coated with polyethylene (PE) film, SP is waxed paper, and SLO is paper modified with hydrophobized starch. The influence of the coating film on the organoleptical, biochemical and microbiological characteristics of the chicken breast meat stored at 4°C was the aim of the study. The mathematical modelling revealed two aspects: (1) the stability period in which the meat safe for consumption is in the range 1.92–2.18 days in the case of all paper types, and (2) cadaverine, the amine generated by protein degradation, is a less sensitive indicator of the meat alteration than microbial growth. The papers coated with PE (RO and IT samples) and with hydrophobized starch (SLO paper) were packaging materials more efficient that the waxed paper (SP sample). The polyethylene film reduced the conversion of putrescine into spermidine in a higher extent than wax.     

Tone-Based Contention Resolution for Multi-hop Wireless Sensor Networks

Wireless Personal Communications - Medium access control protocols with common active period (AP MACs) are frequently used in wireless sensor networks (WSNs) with medium-load traffic requirements....     

Impact of packaging properties on the physical-chemical-microbiological-sensory characteristics of Ricotta cheese during storage

Ricotta is a highly perishable cheese of which shelf-life is strongly influenced by the properties of packages in which it is stored. Four plastic packages currently in use in Italy (IT), Romania (RO), Slovenia (SLO), and Spain (SP) are characterized in term of structure, barrier, and antimicrobial properties, and their efficiency in the ricotta storage at 4°C is assessed. Differential scanning calorimetry and Fourier-transform infrared spectroscopy analysis indicate that the IT and SP packages are made of low-density polyethylene and the RO and SLO packages consist of polyethylene and polyamide 6. Permeability to the water vapour and oxygen transmission rate vary as follows: IT>SLO > RO > SP and SP > IT>RO > SLO, respectively. The SP package expressed the highest antimicrobial inhibition whilst the IT package the lowest. The maximum amounts of volatile compounds in cheese were reached after 3 days in the IT and SP packages and after 6 days in the SLO and RO packages. The score 2.8 for cheese overall acceptability was exceeded after 7 days in the IT, RO, and SP packages and 6 days in the SLO package. Barrier properties of packages significantly influence the shelf-life of ricotta. Low barrier properties resulted in high level of oxygen and water vapours inside the headspace of packages ultimately favour the microbial development. The simultaneous compliance of microbiological safety level and overall acceptability score gives ricotta a shelf-life of 3 days in the IT, RO, and SP packages and 1 day in the SLO package.     

Assessment of mitigation measures contribution to CO2 reduction in sustainable energy action plan

Clean Technologies and Environmental Policy - The paper shows the process of the development of the sustainable energy action plan (SEAP) for the city of Zagreb and analysis of the interaction...     

Non-iterative parameter estimation of the 2R-1C model suitable for low-cost embedded hardware

Frontiers of Information Technology & Electronic Engineering - Parameter estimation of the 2R-1C model is usually performed using iterative methods that require high-performance processing...     

Feed-in tariffs for promotion of energy storage technologies

Faster market integration of new energy technologies can be achieved by use of proper support mechanisms that will create favourable market conditions for such technologies. The best examples of support mechanisms presented in the last two decades have been the various schemes for the promotion of renewable energy sources (RES). In the EU, the most successful supporting schemes are feed-in tariffs which have significantly increased utilisation of renewable energy sources in Germany, Spain, Portugal, Denmark and many other EU countries. Despite the successful feed-in tariffs for RES promotion, in many cases RES penetration is limited by power system requirements linked to the intermittency of RES sources and technical capabilities of grids. These problems can be solved by implementation of energy storage technologies like reversible or pumped hydro, hydrogen, batteries or any other technology that can be used for balancing or dump load. In this paper, feed-in tariffs for various energy storage technologies are discussed along with a proposal for their application in more appropriate regions. After successful application on islands and outermost regions, energy storage tariffs should be also applied in mainland power systems. Increased use of energy storage could optimise existing assets on the market.     

THERMALLY INDUCED VIBRATIONS IN AN ELASTIC BODY WITH A SPHERICAL CAVITY

An elastic heat-conducting body with a cavity can be set in vibration if the temperature of the cavity varies cyclically with time. A simple closed solution can be derived if the geometry is spherical and if the temperature oscillates harmonically. The amplitude of the stresses increases with increasing inertia. If the velocities of temperature waves and elastic waves coincide, no resonancelike amplification of the stresses occurs.     

Experience with an On‐board Weighing System Solution for Heavy Vehicles

Mining, construction, and other special vehicles for heavy use are designed to work under high‐performance and off‐road working conditions. The driving and executive mechanisms of the support structures and superstructures of these vehicles frequently operate under high loads. Such high loads place the equipment under constant risk of an accident and can jeopardize the dynamic stability of the machinery. An experimental investigation was conducted on a refuse collection vehicle. The aim of this research was to determine the working conditions of a real vehicle: the kinematics of the waste container, that is, a hydraulic rotate drum for waste collection; the dynamics of the load manipulator (superstructure); the vibrations of the vehicle mass; and the strain (stress) of the elements responsible for the supporting structure. For an examination of the force (weight) on the rear axle of a heavy vehicle, caused by its own weight and additional load, a universal measurement system is proposed. As a result of this investigation, we propose an alternative system for continuous vehicle weighing during waste collection while in motion, that is, an on‐board weighing system, and provide suggestions for measuring equipment designs.     

Influence of imperfect carrier recovery on satellite QPSK communication system performance

The purpose of this paper is to provide the theoretical approach for determining the bit error probability in detecting a coherent quaternary phase-shift-keyed signal transmitted over a soft-limited channel in the presence of the uplink and downlink noise, as well as the noisy carrier reference signal. The uplink noise is considered in the specific way through the envelope variations and the frequency offset of the signal remitted by the satellite station having influence on the variations of the phase-locked loop parameters in the receiving ground station, consequently on the probability density function of the phase error, i.e. the average bit error probability. The downlink noise is also taken into consideration. The determined results are based on the non-linear phase-locked loop model with primary emphasis on the degradations in the system performance produced by the imperfect carrier signal extraction. Copyright © 1999 John Wiley & Sons, Ltd.     

Experimental determination of mechanical properties and short-time creep of AISI 304 stainless steel at elevated temperatures

The high temperature properties of AISI 304 stainless steel were studied.Basic data about the employed experimental equipment,testing procedures,and specimen geometry were given.The experimental setup was used to obtain stress-strain diagrams from tensile tests at room temperature as well as several elevated temperatures.Furthermore,the specimens were subjected to short-time creep tests at various temperatures.Stress levels for creep testing were established as a percentage of yield stress.The results indic...