China
Africa
Explore chapters and articles related to this topic
Detection Technology
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
Litmus, a dye extracted from lichen, is a pH indicator. When the water-soluble litmus dye is dried on paper, it can be used to test pH. Red litmus paper turns blue to indicate a base and blue litmus paper turns red to indicate an acid. However, litmus indicates pH outside a range of approximately 4.3–8.1. Litmus indicator only classifies the material as an acid for materials with pH of 0–4.3 and as a base with pH of 8.1–14. Litmus will not produce a pH value.
Sensing pH for the Perfect Tomato
Published in Denise Wilson, Sensing the Perfect Tomato, 2019
Litmus indicators are among the oldest and most inexpensive pH sensors. A litmus indicator is a liquid mixture extracted from lichens that turns red when exposed to an acid and blue when exposed to a base. pH indicators that behave similarly to litmus indicators can vary from household liquids like the juice of cooked red cabbage, which is useful for at-home or school science experiments, to more consistent, commercially available litmus indicators like methyl red, which has three color ranges for highly acidic (red), moderate (orange), and highly basic (yellow) solutions. Since litmus was introduced as a way to roughly differentiate liquids by acid, base, or neutral characteristic, a wide range of pH indicators and dyes have been synthesized to provide a coarse measure of pH. Indicators that are particularly relevant to monitoring the tomato maturation and ripening process include methyl red, methyl orange, and bromocresol green, which offer color transitions within a pH unit of 5.1, 3.7, and 4.7, respectively (Pennsylvania State University n.d.). Naturally occurring pH indicators that offer color transitions in the pH ranges that correspond to tomato ripening processes include red cabbage, turnip skin, and the blue dye found in Asian pigeon wings (Khankaew et al. n.d.).
Glossary of scientific and technical terms in bioengineering and biological engineering
Published in Megh R. Goyal, Scientific and Technical Terms in Bioengineering and Biological Engineering, 2018
Litmus is a pH indicator paper (range 4.5–8.3) impregnated with an extracted lichen pigment. It turns red in acidic and blue in alkaline solutions. However, the use of litmus paper as an indicator is not a precise method of pH measurement.
Comparative assessment of lube oil, emission and performance of SI engine fueled with two different grades octane numbers
Published in Journal of the Chinese Institute of Engineers, 2020
Muhammad Usman, Ahmad Naveed, Syed Saqib, Jafar Hussain, Muhammad Kashif Tariq
In the light of published results, researchers have attempted to enhance fuel characteristics to improve performance and decrease harmful environmental pollutants without considering an integral part of SI engine performance, i.e. lube oil condition. The lube oil behavior has been widely studied for biodiesel and diesel, but a criterion has yet to be decided for SI engines running on gasoline. Litmus paper test, pH test, Spectroscopy and the reality that kinematic viscosity of lube oil progressively rises with the engine running hours are signs of various engine components’ wear rates. At higher temperature, low viscosity lube oil deteriorates due to higher rate of oxidation process (Koehler et al. 2003). During engine running, oil in lubricants can be replaced by water molecules at mating layers which results in lowering the lube oil strength and maturing the surfaces that, additionally, act like catalytic agent for degradation of the lube oil (Kubo et al. 2001; Totten 2006; Collister 1997). Contamination or oxidation process generally increases the viscosity of used lube oil (Rafie et al. 2013). Furthermore, in comparison to non-degraded lube oil, the degraded oil and various additives available in it are dangerous and destructive to health and environment. If the degraded oil gets blended with the water in drains, it can severely spoil the quality of water (Vazquez-Duhalt 1989). Dumping the lube oil into earth can effortlessly allow harmful contaminants and additives into the water present at the surface of earth (Andrews 2008). Therefore, impact of fuels on lube oil condition must also be studied to develop technologies related to SI engines.
Simultaneous removal of lead and cadmium ions from simulant and industrial waste water: using Calophyllum Inophyllum plant materials as sorbents
Published in International Journal of Phytoremediation, 2022
Sneha Latha Pala, Wondwosen Kebede Biftu, M. Suneetha, Kunta Ravindhranath
Stems of Calophyllum inophyllum were half-dried and digested in conc. H2SO4 for overnight. Then the material was further digested by heating in a round bottom flash connected to a water condenser for complete carbonization to occur. Then, the contents of the flask were poured slowly into a beaker containing distilled water and stirred well. Thus, generated active carbon was filtered and thoroughly washed with distilled water until the washing were neutral to litmus paper. The active-carbon was dried at 105 °C, cooled and preserved in brown bottles. The active carbon obtained from the stems of Calophyllum inophyllum was termed as: CISAC (Figure 2).
Lactate detection by colorimetric measurement in real human sweat by microfluidic-based biosensor on flexible substrate
Published in The Journal of The Textile Institute, 2019
Arife Kuşbaz, İkilem Göcek, Gülçin Baysal, Fatma Neşe Kök, Levent Trabzon, Hüseyin Kizil, Burçak Karagüzel Kayaoğlu
A narrow sample group of 10 healthy individuals including five women, five men, within an age of 20–25 was examined (Table 1). The sweat samples were collected from the individuals that perspired adequately after walking with a high speed for at least 30 min. The samples were divided into three fractions and examined in three different ways; (a) first fraction (20 µL) was introduced on the reservoirs of the designed biosensor and color intensity was assessed, (b) for second fraction, commercial lactic acid assay kit purchased from Biovision company was utilized for the quantitative analysis and (c) finally, pH value of sweat was determined by pH detection strip (litmus paper).