Forms of continuity in architectural space

Starting from understanding the architectural space as one of many modes of continual urban space, the research focuses on the interpretation of concepts developed in order to describe the properties of the so-called cognitive architecture. In the last decade, guided by the issue of social effects of architecture, many investigations in the field of theory of architecture were conducted within the framework constituted from the philosophical elaborations of the notion of affect, mainly by Gilles Deleuze, Felix Guattari and Brian Massumi. In some proposals, the concept of cognitive architecture was established to describe the impact that the space occupied with new information and communication technologies exerts on the domains of intellect and mental disposition, coupled with the practices of every-day life. Cognitive architecture emerges as a consequence of the intertwinings of physical and mental processes in individuals’ bodies, as well as between them, that characterize social space in contemporary communication-information age. The concept of cognitive architecture thus emphasizes the ways in which technologies of communication shape the mental sphere of humans and its relation to material processes in humans’ bodies. Paralleling this phenomenon, in the field of architectural design, the architect Philippe Rahm has developed a practice based on investigations into the morphogenetic potential of material flows in space. The flows in question comprise a series of chemical, physical and biological transformations through which non-living materials and human mind and body become directly connected. Comparing and intersecting theoretical interpretations of cognitive architecture with Rahm’s design strategies, we shall offer a set of notions that trace new forms of unity between mind, body and architectural space, as a contribution to the exploration of the concept of bodily-mental-social continuum

Autoxidation of lipids in parchment

Historic parchment is a macromolecular material, which is complex due to its natural origin, inhomogeneity of the skin structure, unknown environmental history and potential localised degradation. Most research into its stability has so far focussed on thermal and structural methods of analyses. Using gas chromatographic analysis of the atmosphere surrounding parchment during oxidation, we provide the experimental evidence on the production of volatile aldehydes, which can be the products of lipid autoxidation. Oxidation of parchment with different aldehyde emissions was additionally followed in situ using chemiluminometry and the same techniques were used to evaluate the oxidation of differently delipidised parchment. It was shown that the production of peroxides and the emission of aldehydes from the material decrease with lower lipid content. Building on this evidence, we can conclude that the presence of lipids (either initially present in the skin or resulting from conservation intervention) leads to oxidative degradation of collagen and that the non-destructive analysis of the emission of volatiles could be used as a quick tool for evaluation of parchment stability

Emission of reactive oxygen species during degradation of iron gall ink

Iron gall inks are characterised by high contents of acids and transition metals, promoting degradation of cellulose due to hydrolysis and oxidation, respectively. Their chemical interaction with the environment is not well understood, especially in view of emissions of degradation products which could lead to spread of degradation processes. In order to study the emissions, we employed gas chromatography/mass spectrometry following headspace micro-extraction, and liquid chromatography following hydroxyl radical scavenging with appropriate probes. We also studied chemiluminescence of cellulose affected by ink degradation. We show that while the emissions of organic volatile degradation compounds by inks are less intense than those of surrounding paper, ink does promote the degradation of cellulose across big distances (from object to object). We were able to link this to emission of reactive oxygen species, probably hydrogen peroxide. Its emission from ink is considerably more intensive than from paper

An Overview of Conventional and Emerging Analytical Methods for the Determination of Mycotoxins

Mycotoxins are a group of compounds produced by various fungi and excreted into the matrices on which they grow, often food intended for human consumption or animal feed. The high toxicity and carcinogenicity of these compounds and their ability to cause various pathological conditions has led to widespread screening of foods and feeds potentially polluted with them. Maximum permissible levels in different matrices have also been established for some toxins. As these are quite low, analytical methods for determination of mycotoxins have to be both sensitive and specific. In addition, an appropriate sample preparation and pre-concentration method is needed to isolate analytes from rather complicated samples. In this article, an overview of methods for analysis and sample preparation published in the last ten years is given for the most often encountered mycotoxins in different samples, mainly in food. Special emphasis is on liquid chromatography with fluorescence and mass spectrometric detection, while in the field of sample preparation various solid-phase extraction approaches are discussed. However, an overview of other analytical and sample preparation methods less often used is also given. Finally, different matrices where mycotoxins have to be determined are discussed with the emphasis on their specific characteristics important for the analysis (human food and beverages, animal feed, biological samples, environmental samples). Various issues important for accurate qualitative and quantitative analyses are critically discussed: sampling and choice of representative sample, sample preparation and possible bias associated with it, specificity of the analytical method and critical evaluation of results

Plastics in Heritage Collections: Poly(vinyl chloride) Degradation and Characterization

Museums and galleries house increasingly large collections of objects and contemporary art made of plastic materials, many of which undergo rapid material change. The main degradation processes of poly(vinyl chloride) (PVC) are elimination of HCl and plasticizer migration or leaching. This results in visible discolouration, stickiness and cracking. Degradation is known to be a multi-stage process that includes HCl elimination, formation of conjugated polyenes and cross-linking. Elimination of HCl begins due to structural irregularities (allylic and tertiary chlorides) and results in the formation of polyenes. When at least 7 conjugated double bonds are present, discolouration of PVC becomes visible. Non-invasive techniques, such as IR and Raman spectroscopy are used for polymer identification and plasticizer quantification. Plasticizer degradation and particularly the late stages of PVC degradation can be investigated using SEC, GC-MS, TGA and DSC. Studies in heritage collections have revealed that, apart from HCl, PVC objects emit 2-ethylhexanol and other volatile degradation products, however, there is currently no indication that HCl is emitted at usual indoor conditions. There seems to be a general lack of systematic research into PVC degradation at the conditions of storage and display, which could result in the development of dose-response functions and in the development of preventive conservation guidelines for the management of PVC collections

A case of complete heart block with a therapeutic dilemma

Third-degree atrioventricular (AV) block, also referred to as complete heart block (CHB), is caused by a cardiac conduction system disease or damage resulting in no conduction through the atrioventricular node (AVN), leading to complete dissociation of the atrial and ventricular beats. We present a case of a patient with acquired CHB who has been treated without a permanent pacemaker

A myocardial infarction caused by an epicardial radiofrequency ablation

A myocardial infarction (MI) occurs when blood flow in the coronary blood vessel decreases or stops causing damage to the heart muscle. Cardiac radiofrequency ablation (RFA) is a procedure using catheters inserted through a vein or artery which reach heart and deliver RF energy in the form of heat to modify the heart tissue that triggers or sustains tachycardia or tachyarrhythmia

Podmazivanje krutim i plinovitim tvarima

Kroz ovaj rad dan je prikaz danas korištenih plinovitih i krutih maziva. Objašnjena su njihova svojstva i načini nanošenja na strojne elemente koje treba podmazivati i naveden je primjer iz prakse – podmazivanje zrakom ležajeva turbine zubarskog alata

Representation of working class in popular Croatian and Yugoslavian Movies

Rad ne sadrži sažetak