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Iskalni niz: "ključne besede" (quality control) .

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1.
Quality control of thermally modified timber using dynamic vapor sorption (DVS) analysis
Miha Humar, Rožle Repič, Davor Kržišnik, Boštjan Lesar, Romana Cerc Korošec, Christian Brischke, Lukas Emmerich, Gregor Rep, 2020, izvirni znanstveni članek

Povzetek: The importance of thermal modification is increasing worldwide. Increased use of thermally modified timber (TMT) has resulted in a need for reliable quality control, comprising control of variation of the production within defined limits, allowing third-party control in the case of certification and the regulation of customer complaints and claims. Techniques are thus needed to characterise the modification of quality in terms of improved target properties of TMT during industrial production, and of TMT products that have been in service for an arbitrary time. In this study, we aimed to utilise dynamic vapor sorption (DVS) for this purpose. Norway spruce (Picea abies) and European beech (Fagus sylvatica) samples were thermally modified at different temperatures according to different heat treatment techniques: (1) the Silvapro process based on an initial vacuum; (2) an air heat treatment, whereby samples were wrapped in aluminium foil; (3) thermal modification of wood samples in the ambient atmosphere in a laboratory oven. Wood samples from closed processes were analysed for validation. TMT was characterised with respect to mass loss, colour and density. Mass loss of wood due to modification (MLTM) was correlated with factors derived from DVS analysis. The present DVS measurements suggest that the equilibrium wood moisture content (EMC95% RH), the time to reach 10% wood moisture content (t10% MC), and the elongation factor, c, derived from a logarithmic function, can serve as alternative parameters to characterise the quality of several thermal modification processes. Further studies are recommended using other wood species, different modification processes and further parameters gained from DVS measurements to understand the robustness and the predictive power of the applied technique
Ključne besede: thermal modification, quality control, dynamic vapour sorption, wood, moisture content
Objavljeno v DiRROS: 31.08.2023; Ogledov: 258; Prenosov: 133
.pdf Celotno besedilo (1,91 MB)
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2.
Documenting metrological traceability as intended by ISO 15189:2012 : a consensus statement about the practice of the implementation and auditing of this norm element
Marc H. M. Thelen, Florent Vanstapel, Pika Meško-Brguljan, Bernard Gouget, Guilaine Boursier, Edward Barrett, Christos Kroupis, Maria Lohmander, Luděk Šprongl, Tatjana Vodnik, 2019, izvirni znanstveni članek

Povzetek: ISO15189:2012 requires medical laboratories to document metrological traceability of their results. While the ISO17511:2003 standard on metrological traceability in laboratory medicine requires the use of the highest available level in the traceability chain, it recognizes that for many measurands there is no reference above the manufacturer's selected measurement procedure and the manufacturer's working calibrator. Some immunoassays, although they intend to measure the same quantity and may even refer to the same reference material, unfortunately produce different results because of differences in analytical selectivity as manufacturers select different epitopes and antibodies for the same analyte. In other cases, the cause is the use of reference materials, which are not commutable. The uncertainty associated with the result is another important aspect in metrological traceability implementation. As the measurement uncertainty on the clinical samples is influenced by the uncertainty of all steps higher in the traceability chain, laboratories should be provided with adequate and appropriate information on the uncertainty of the value assignment to the commercial calibrators that they use. Although the between-lot variation in value assignment will manifest itself as part of the long-term imprecision as estimated by the end-user, information on worst-case to be expected lot-lot variation has to be communicated to the end-user by the IVD provider. When laboratories use ancillary equipment that potentially could have a critical contribution to the reported results, such equipment needs verification of its proper calibration and criticality to the result uncertainty could be assessed by an approach based on risk analysis, which is a key element of ISO15189:2012 anyway. This paper discusses how the requirement for metrological traceability as stated in ISO15189 should be met by the medical laboratory and how this should be assessed by accreditation bodies.
Ključne besede: laboratories, medical laboratory science, risk management, quality control, quality improvement, health care quality assurance, metrological traceability
Objavljeno v DiRROS: 22.10.2020; Ogledov: 1221; Prenosov: 265
URL Povezava na datoteko

3.
Amino- and ionic liquid-functionalised nanocrystalline ZnO via silane anchoring - an antimicrobial synergy
Marjeta Čepin, Vasko Jovanovski, Matejka Podlogar, Zorica Crnjak Orel, 2015, izvirni znanstveni članek

Povzetek: Temperature has critical impact on food quality and safety within food supply chain, therefore, food should be kept at the defined storage temperature range. Final consumer should be assured when buying food about actual temperature and thermal history of the selected food product and this is why it should be indicated on the packed or prepacked item. The chromogenic temperature indicator for cold food chain was prepared from suitable active material packed in the properly structured holder. When temperature rises above the defined storage temperature, the active material changes colour and physical state (solid/liquid). Simultaneously, special packaging structure enables irreversible recording of the time exposed to the elevated temperature. The active material was made of thermochromic composite, consisting of dye, developer and solvent. It changes colour at its melting point, being coloured below and discoloured above it. The temperature is called activation temperature of the composite. Its value was adjusted by appropriate solvent and additives used for preparation of the composite, to reach the desired value. The temperature dependent colour change of the composite was determined by colorimetric measurements. The conditions for best observation of the change by naked eye were also examined. The structure of the active material’s holder was analyzed for best displaying of the time spend at high temperature (above the activation temperature). Functioning of the indicator was examined with growth of pathogens as a function of migration of the active material at temperature above the required storage temperature of the food. It was found out that the described chromogenic temperature indicator for cold food chain shows the thermal history of food storage by colour-, phase- and migration changes of the active composite material and consequently would be reliable as indicator in cold food chain to indicate temperature abuse and would disclose potential growth of psychrophilic microorganisms.
Ključne besede: Chromogenic temperature indicator, Food cold chain, Food quality and safety, Temperature control, Thermal history
Objavljeno v DiRROS: 16.12.2014; Ogledov: 6117; Prenosov: 926
URL Povezava na celotno besedilo

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