Analysis of the color properties of papers subjected to different recycling numbers in electrophotographic (toner) printing

Purpose In this present study, electrophotographic printing is made on papers which are subjected to different recycling numbers, and this paper aims to examine the colour changes of this printing type. Design/methodology/approach Four-colour electrophotographic printing is carried out on adhering to the INGEDE 11p standard recycled papers four times under the same conditions. Colour measurements are made by means of electrophotographic printed colour scales printed on these recycled papers. Colour measurements are made with the X-Rite eXact spectrophotometer according to the ISO 13655:2017 standard. As a result of colour measurements, colour differences (ΔL′, ΔH′, ΔC′, ΔE00) of recycled papers are determined using some formulas. Findings According to the values obtained after four recycling, the highest ΔL′ value is found to be 4.80 yellow and the lowest 1.92 black. Again, according to the measurement results, it is determined that the highest ΔE00 is yellow colour with a value of 5.66, and lowest ΔE00 is black colour with a value of 1.98. In ΔH′, black colour is the highest value of 12.61, the lowest value with −2.05 is obtained in magenta colour. It was observed that the highest ΔC′ value is 2.98 in yellow, and the lowest value is −0.28 in black. Originality/value In the printing industry, sometimes customers want to monitor the colour differences in the printing by taking the L′a′b′ obtained values as a result of printing from the printing houses. If the colour differences exceed the tolerance values, then they can interfere with the printing. As a result of the calculations, colour changes in electrophotographic printing are observed with many parameters. This study can be a pioneer for the studies that can be done on this subject.

Reversible colour/luminescence colour changes of tetracyanoruthenium(II) complexes by sorption/desorption of water molecules in crystal

We report colour/luminescence colour changes of M[Ru(bpy)(CN)4] crystal (M2+ = Ca2+, Sr2+, and Ba2+; bpy = 2,2’-bipyridine). An X-ray crystallographic study reveals the crystals are constructed by linear-chains of {[Ru(bpy)(CN)4][Ca(H2O)5]}n,...

Changes in the Medieval Colour Scheme of the Southern Façade of Wrocław Town Hall—A Case Study

The aim of this article is to discuss the colour transformations of one of the most representative Gothic façades in Central Europe—the southern façade of Wrocław Town Hall. Based on iconographic, architectural, and stratigraphic research, it was possible to find the remains of two stages of medieval colour changes. Based on these discoveries, an attempt was made to reconstruct both phases of the medieval colour scheme. The research findings enable the object to be described with regard to the architecture and colours of late gothic façades in Poland, Czechia and Germany.

Can the Dynamic Colouration and Patterning of Bluelined Goatfish (Mullidae; Upeneichthys lineatus) Be Perceived by Conspecifics?

Bluelined goatfish (<i>Upeneichthys lineatus</i>) exhibit dynamic body colour changes and transform rapidly from a pale, buff/white, horizontally banded pattern to a conspicuous, vertically striped, red pattern when foraging. This red pattern is potentially an important foraging signal for communication with conspecifics, provided that <i>U. lineatus</i> can detect and discriminate the pattern. Using both physiological and behavioural experiments, we first examined whether <i>U. lineatus</i> possess visual pigments with sensitivity to long (“red”) wavelengths of light, and whether they can discriminate the colour red. Microspectrophotometric measurements of retinal photoreceptors showed that while <i>U. lineatus</i>lack visual pigments dedicated to the red part of the spectrum, their pigments likely confer some sensitivity in this spectral band. Behavioural colour discrimination experiments suggested that <i>U. lineatus</i>can distinguish a red reward stimulus from a grey distractor stimulus of variable brightness. Furthermore, when presented with red stimuli of varying brightness they could mostly discriminate the darker and lighter reds from the grey distractor. We also obtained anatomical estimates of visual acuity, which suggest that <i>U. lineatus</i> can resolve the contrasting bands of conspecifics approximately 7 m away in clear waters. Finally, we measured the spectral reflectance of the red and white colouration on the goatfish body. Visual models suggest that <i>U. lineatus</i> can discriminate both chromatic and achromatic differences in body colouration where longer wavelength light is available. This study demonstrates that <i>U. lineatus</i> have the capacity for colour vision and can likely discriminate colours in the long-wavelength region of the spectrum where the red body pattern reflects light strongly. The ability to see red may therefore provide an advantage in recognising visual signals from conspecifics. This research furthers our understanding of how visual signals have co-evolved with visual abilities, and the role of visual communication in the marine environment.

Autonomic Dysfunction Post-Inoculation with ChAdOx1 nCoV-19 Vaccine

This report describes persistent paresthesia, haemodynamic changes including orthostatic tachycardia, and skin colour changes due to autonomic dysfunction after a single dose of the ChAdOx1-nCoV-19 vaccine (AstraZeneca) in a healthy 29-year-old male.

A novel growth and isolation medium for exoelectrogenic bacteria

A microbiological isolation and growth medium that can effectively discriminate electrochemically active exoelectrogenic bacteria from other non-exoelectrogenic bacteria, is currently unavailable. In this study, we developed a novel chromogenic growth and isolation solid medium based on MnO2 that can selectively allow the growth of exoelectrogenic bacteria and change the medium colour in the process. Known exoelectrogenic bacteria such as Shewanella oneidensis MR1 and other such bacteria from functional microbial fuel cell (MFC) anodes were capable of growing and changing colour in the novel growth medium. On the contrary, non-exoelectrogenic bacteria such as Escherichia coli ATCC 25922 were incapable of growing and inducing a colour changes in the novel medium. Further biochemical characterisation of these isolated exoelectrogenic bacteria by Raman micro-spectroscopy demonstrated that these bacteria over express cytochrome proteins that are vital in extracellular electron transfer events. This medium is a convenient method to isolate exoelectrogenic bacteria from complex environmental samples.

Development and Validation of a Stability-Indicating HPLC Method for the Simultaneous Determination of trans-Resveratrol and cis-Resveratrol in an Injectable Solution

trans-Resveratrol, a phytochemical compound with antioxidant power and various therapeutic effects, such as cardioprotective, chemopreventive, and neuroprotective, among others, has disadvantages of poor solubility and limited stability, creating difficulties for the development of new strategies for its quantification. This study developed and validated an analytical stability method for trans-resveratrol by high-pressure liquid chromatography with photodiode-array detection (HPLC-PDA), which allowed its quantification in the presence of its degradation products. The quantification of trans-resveratrol occurred at a retention time of 2.6 min, with ammonium formate (10 mM, pH = 4)/acetonitrile, 70/30 v/v, as mobile phase. The validation met the ICH Q2 criteria of specificity, method linearity (2.8–4.2 μg/ml), precision and accuracy, robustness, quantification limit (0.176 μg/ml), and detection (0.058 μg/ml). As degradation products, cis-resveratrol was observed at 3.9 min, which could be resveratrone in 3.2 min and five unidentified products in 0.7, 1.0, 1.4, 1.8, and 5 min. Some solutions subjected to temperature stress of 40 and 60°C, UV light, and acidic and basic hydrolysis exhibited colour changes. An analytical method was obtained by HPLC-PDA, which allowed quantifying the stability of trans-resveratrol in a fast and specific manner in the presence of its degradation products.

Assessment of Microbiological Safety and Physicochemical Changes of Grey Oyster Mushroom (Pleurotus sajor-caju) during Storage at 4 °C and 25 °C

This study aimed to evaluate the microbiological and physicochemical properties of grey oyster mushroom during storage (day 0, 3, 6, 9, 12) at 4 °C and 25 °C. The microbial quality and safety analyses were aerobic plate count (APC), yeast and mould count, Escherichia coli count, Bacillus cereus count, and Listeria monocytogenes count, while the physicochemical analyses were pH, water activity, colour, and firmness. Grey oyster mushroom stored at 4 °C showed increasing trend in all microbial counts. A similar trend was observed at 25 °C, but with higher microbial counts except for L. monocytogenes which had a slight reduction from 1.82 ± 1.16 at day 0 to 0.24 ± 0.34 log CFU/g at day 6. The pH of grey oyster mushroom was quite stable when stored at 4 °C (6.42 ± 0.03 at day 0 to 6.46 ± 0.21 at day 12). A decrease in pH was observed when the mushroom was stored at 25 °C (6.42 ± 0.03 at day 0 to 5.38 ± 0.93 at day 6). The Browning Index (BI) increased which indicated by the colour changes on the mushroom cap (front and back) especially at 25 °C. Firmness analysis carried out on mushroom cap and stalk showed a decreasing trend during storage, at which 25 °C displayed prominent loss of firmness in cap and stalk as compared to 4 °C. In conclusion, slower deterioration was observed in grey oyster mushroom stored at 4 °C as compared to 25 °C. This is based on lower microbial counts, and minimal changes in pH, BI, and firmness of grey oyster mushroom.

Indicator Made from Countryside Flower Petals

Present research introduces on the natural indicator (Acid-Base). For this samples were collected from countryside flower petals. These are pink Madhabilata flower, violet Dahlia flower, yellowish red Miralibis Jalapa, light pink Nerium Oleander. With the help of pH meter colour changes were observed using Soxhlet extractor. Cold extract of the flower petals are prepared. For this study we use UV/Visible Spectrophotometer to determine the maximum wave length. The decreasing order of intercept from the above spectroscopic plots that pink Madhabilata> violet Dahlia>redish yellow Miralibis Jalapa> light pink Nerium Oleander. Natural indicators show prominent colour changes in acidic and basic solutions. So, it is easily replaceable to the synthetic indicator which is toxic in nature. These natural indicators are easily available, cheap, environment friendly and also nature friendly.

Atlas of Micromorphological Degradation of Archaeological Birch Bark

In this paper we present an atlas of micromorphological degradation of archaeological birch bark for the first time. We analysed the morphology of 13 samples extracted from ice-logged, waterlogged and cave-retrieved objects dated from the Neolithic to the Middle Age by means of light microscopy (LM) and transmission electron microscopy (TEM). We then compared their morphology to that of a contemporary sample, both intact and decayed. In all samples, 13 morphological characteristics that can be associated with fungal, bacterial, chemical, mechanical and light degradation are defined and described, and example LM and TEM images are provided. This novel atlas provides conservator-restorers a much-needed tool to relate the macroscopic appearance to the microscopic structure of birch bark objects. The most important macroscopic features allowing estimation of the state of preservation at the cell level are colour changes, loss of pliability, presence of delamination and increased brittleness. Colour change and delamination can be connected to microscopic features, and microscopic analysis can trace whether they were caused by biotic, chemical or physical decay. However, increased brittleness cannot be connected to a specific microscopic feature.