The quality of pork and the shelf life of the chosen carcass elements during storage depending on the method of carcass chilling

The aim of this study was to analyze the influence of the chilling method on meat quality and the microbiological durability of pork cuts during storage. The left half‐carcasses were put through the shock tunnel and the right half‐carcasses were placed directly in the chilling room. After chilling, pH measurements were taken in two muscles. The carcasses were cut, and drip loss, marbling, and color of LL muscle were estimated. The microbiological quality of meat elements was estimated according to the procedure included in the EC regulation. The total viable count tests were done after chilling, 8, 12, 14, 16, and 18 days of storing. The drip loss was higher in the group that was chilled slower. In the group of carcasses chilled quickly lower mass losses were observed. The positive effect of ?26 °C in the shocking tunnel on the microbial quality of carcass and vacuum packed primal cuts was not as intensive as expected. As showed the above presented results of the study, the economic aspect of pork carcass chilling system first of all should be taken under consideration in meat production.

Practical applications

The study shown that very low temperatures in the shock tunnel in chilling process of the pig carcasses (e.g., ?26 °C) do not bring the expected results as a significant increase in the shelf life of meat cuts and quality of meat. Therefore, it is useful to modify the regime of temperature through the use in industrial practice of higher temperatures in the shock tunnel. The economic aspect of pork carcass chilling system first of all should be taken under consideration in choosing of the chilling method.     

Planar and three-dimensional thick-film thermoelectric microgenerators

This paper describes manufacturing process as well as thermoelectric properties and long-term stability of planar and three-dimensional (3-D) thermoelectric structures made in thick-film/LTCC technology. Screen-printed thick-film thermocouples based on PdAg, Ag and Ni inks were manufactured and investigated. Seebeck coefficient and electrical output power were measured with the help of custom built automatic measuring system. Achieved results were compared with literature data and earlier authors’ results. Seebeck coefficient greater than 20 μV/K and about 5–8 μW/junction output power were measured for temperature difference of about 100 K for Ag–Ni thick-film planar thermocouple made on both used substrates. This combination of materials was chosen to create three-dimensional thick-film thermocouples (reported in the literature for the first time). We received for them Seebeck coefficient greater than 15 μV/K and the output power on level of 1 μW/junction for temperature gradient of about 60 K.     

At the Edges of Photosynthetic Metabolic Plasticity—On the Rapidity and Extent of Changes Accompanying Salinity Stress-Induced CAM Photosynthesis Withdrawal

The common ice plant (Mesembryanthemum crystallinum L.) is a facultative crassulacean acid metabolism (CAM) plant, and its ability to recover from stress-induced CAM has been confirmed. We analysed the photosynthetic metabolism of this plant during the 72-h response period following salinity stress removal from three perspectives. In plants under salinity stress (CAM) we found a decline of the quantum efficiencies of PSII (Y(II)) and PSI (Y(I)) by 17% and 15%, respectively, and an increase in nonphotochemical quenching (NPQ) by almost 25% in comparison to untreated control. However, 48 h after salinity stress removal, the PSII and PSI efficiencies, specifically Y(II) and Y(I), elevated nonphotochemical quenching (NPQ) and donor side limitation of PSI (Y_ND), were restored to the level observed in control (C₃ plants). Swelling of the thylakoid membranes, as well as changes in starch grain quantity and size, have been found to be components of the salinity stress response in CAM plants. Salinity stress induced an over 3-fold increase in average starch area and over 50% decline of average seed number in comparison to untreated control. However, in plants withdrawn from salinity stress, during the first 24 h of recovery, we observed chloroplast ultrastructures closely resembling those found in intact (control) ice plants. Rapid changes in photosystem functionality and chloroplast ultrastructure were accompanied by the induction of the expression (within 24 h) of structural genes related to the PSI and PSII reaction centres, including PSAA, PSAB, PSBA (D₁), PSBD (D₂) and cp43. Our findings describe one of the most flexible photosynthetic metabolic pathways among facultative CAM plants and reveal the extent of the plasticity of the photosynthetic metabolism and related structures in the common ice plant.     

Catalytic materials manufactured by the polyol process for monolithic dye‐sensitized solar cells

Three types of screen‐printable catalytic pastes were successfully prepared to be used as counterelectrode for monolithic dye solar cells encapsulated with glass frit. The electroless bottom‐up method or so‐called polyol process has been applied to fabricate thermally stable SnO₂:Sb/Pt and carbon black/Pt nanocomposites. The catalytic and electric properties of these materials were compared with a new platinum‐free type of carbon counterelectrode. The layers containing low platinum amounts (less than 5 µg/cm²) exhibit a very low charge transfer resistance of about 0·4 Ω · cm². Also the conductive carbon layer shows an acceptable charge transfer resistance of 1·6 Ω · cm². Additionally the catalytic layer containing porous carbon black reveals excellent sheet resistance below 5 Ω/□; this feature has enabled to work out a low cost counterelectrode which combined suitable catalytic and conductive properties. The layers have been characterized using following methods: electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FE‐SEM), energy filter transmission electron microscopy (EF‐TEM) and inductively coupled plasma mass spectroscopy (ICP‐MS). Copyright © 2008 John Wiley & Sons, Ltd.     

Assessment of protein fractions of three cultivars of <Emphasis Type="Italic">Pisum sativum</Emphasis> L.: effect of germination

Protein composition, nitrogen and amino acid content of Osborne fractions in different cultivars of Pisum sativum L. (cv. ucero, cv. ramrod and cv. agra) seeds were investigated and the effect of germination on these parameters was also analysed. Albumins comprised the main protein fraction in raw seeds, globulins were constituted mainly by vicilin, with a smaller proportion of the glutelin and prolamine fractions. Regarding the amino acid profile of pea protein fractions, although differences among pea cultivars were found, in general albumin, glutelin and prolamine fractions presented Asp, Glu and Gly as the major non-essential amino acids (NEAA) and Lys as the main essential amino acid (EAA). The globulin fraction, however, presented Asp, Glu, Gly and Arg as the major NEAA and Leu, Phe, Lys, and Thr as the main EAA. In general, the albumin fraction accounted for more sulphur amino acids and Lys, followed by the glutelin + prolamine fraction. Germination caused an increase in the total protein content of P. sativum cv. ucero and P. sativum cv. ramrod. In the albumin fraction a wide number of proteins underwent degradation and convicilin disappeared from the globulin fraction of pea sprouts whilst vicilin and legumin decreased slightly. In general, all the Osborne fractions of pea sprouts presented higher EAA contents than raw seeds. The estimated essential amino acid indexes of protein fractions for P. sativum cv. ucero (EAAI_adult and EAAI_egg) improved with the germination process whilst for P. sativum cv. ramrod and P. sativum cv. agra depended on the Osborne fraction.     

Development and Characterization of Grain Husks Derived Lignocellulose Filler Containing Polypropylene Composites

Oat and spelt husks (OH and SH, respectively) lignocellulosic biomass derived fillers have been compared with commercial wood flour (WF) in respects to their morphology, chemical composition, bulk density, aspect ratio, and thermal stability. OH and SH have been obtained by both mechanical milling and steam explosion auto‐hydrolysis treatment at various processing conditions. Reinforcement efficiency of OH and SH derived lignocellulosic biomass fillers on the flexural properties of maleic acid‐grafted polypropylene (PPgMA) compatibilized polypropylene (PP) composites is compared with that of WF. The compatibilized PP composites have been manufactured by melt compounding. Flexural test specimens of the compatibilized PP composites have been manufactured by injection molding. It has been demonstrated that both the husks derived lignocellulose fillers can be used to improve flexural modulus and maximal flexural strength of PP, although its modifying effect is somewhat smaller in comparison to WF reinforcement, most probably due to higher cellulose content of the latter. Husks derived lignocellulose filler‐reinforced PP composites, however, demonstrate increased flexibility in comparison to WF‐filled systems. POLYM. ENG. SCI., 59:2467–2473, 2019. © 2019 Society of Plastics Engineers     

Pre‐arrangement of solvability,complexity, stability and quality of GPC systems

A design problem of generalized predictive control (GPC) of plants characterized by discrete‐time models with a non‐zero transportation‐delay is considered. Conditions for the existence of the solution of the problem in terms of relevant design parameters (tuning knobs) are proposed and the system characteristics are discussed. Several design hints suitable for such plant models are proposed. Consequently, it is shown that by a suitable choice of the GPC tuning knobs a definite pre‐arrangement of the solvability, complexity, stability and quality (including robustness) of the resultant GPC control systems can be achieved. Some numerical examples are also given to illustrate the design problem and proposed methodology. Copyright © 2002 John Wiley & Sons, Ltd.     

The Systematic Errors of a Time-Division Power Converter under Sinusoidal and Nonsinusoidal Conditions

Systematic errors of an astable multivibrator based time-division active power converter are analyzed. Results of a computer simulation for sinusoidal and nonsinusoidal input signals are compared with test measurements of a standard converter. The paper shows that a conversion error of the power converter can be estimated from the harmonic content of the input waveforms.     

Zur Wahl der Struktur von Stangenmechanismen

Zusammenfassung Am Beispiel eines Lenksystems mit zwei doppeltwirkenden Hydraulikzylindern für Fahrzeuge mit Knickgelenk wird eine Methode zur Prüfung aller m?glichen Strukturen von Stangenmechanismen dargestellt. Danach wird mit Hilfe der Polyoptimierung die Geometrie des Getriebes bestimmt, das'den Konstruktions- und Einsatzbedingungen genügt. Die Methode der Polyoptimierung liefert dem Konstrukteur, im Vergleich zu den verbreiteten Optimierungsmethoden mit einer Zielfunktion, praxisnahe Ergebnisse. Der angewendete L?sungsweg zeigt neue M?glichkeiten für Mechanismen zur Lenkung von Fahrzeugen mit Knickgelenk. Diese L?sungen charakterisieren günstige Leistungsparameter.     

Temperature properties of the static induction transistor

It is shown that the temperature coefficient of the drain current of the triode like a JFET/SIT/is proportional to the potential barrier height of the device for small current densities. At large current densities the drift velocity and the gate-source built in patential are responsible for the temperature dependence of the drain current.