Phenols are probably the oldest disinfectants used, first ever used by Lister, in 1867. He used it to control surgical infections in the operating room. Phenol is often used in throat lozenges but it has little antimicrobial effect at low concentration. However, it has a remarkable antimicrobial effect at concentration above 1%. It is now rarely used because of its comparatively more side effects, such as it irritates the skin and has disagreeable odor. “Derivative of phenols are called phenolics.” In these substances, the molecule of phenol is chemically altered, in order to make it more efficient and reduce its irritating qualities. Examples are cresol, hexachlorophene and so on. MODE OF ACTION: Phenols actively precipitate proteins and denatures proteins hence, damaging the microbe. By lowering the surface tension, they disrupt membranes effecting, the stability of microorganism. It results in the leakage of cellular components, by injuring the lipid-containing membranes. EFFECTIVENESS: It kills vegetative cells and some fungi. It is moderately, effective against spores. It is rarely used, expect as a standard of comparison. Their effect is immediate. ADVANTAGES: The advantages of using phenols and related compounds is that, they are stable to heating and drying. Moreover, they are unaffected by organic compounds. DISADVANTAGES: When used in its pure form, phenol is harmful to tissues It also has a disagreeable odour. EXAMPLE: 1.
For this lab, zeolite and magnetized zeolite were synthesized and compared with charcoal to find out with would be the most effective in the sequestering of Procion Red dye. Finding the concentration and absorbance of each zeolite, magnetized zeolite, and charcoal, along with a calibration curve, the best adsorbent is determined. Charcoal was the overall best sequestration of the Procion Red dye, since the adsorbent was highest compared to the others. Introduction Pollution has increased in the environment over the years, so the purpose of this experiment is to find the best adsorbent of chemicals to reduce the pollution.
In conclusion, both of these examples strongly support the main idea
Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above.
There has recently been a lot of discussion regarding en primeur, whether it is sustainable for the long term or needs urgent changes or a holiday (Atkin, 2012). However, as I pointed out earlier the trade of fine Bordeaux wines cannot be restricted to en primeur, one needs to consider the whole value chain. As we have seen earlier how the trade system of Bordeaux works let me briefly summarize the main advantages and disadvantages of the system. STRENGTHS First of all, the en primeur campaign every spring following the harvest for nearly four months the new Bordeaux vintage is in the centre of attention of press, merchants and the consumers.
Pesticides and How it Works Abstract: A pest is "a plant or creature unfavorable to people or human concerns". Pesticide is Chemical or natural substance intended to slaughter or retard the development of pests that harm or meddle with the development of products, bushes, trees, timber and other vegetation coveted by people. Keywords: Antimicrobials, Antimicrobials, Herbicides Introduction:
Effect of Yeast on Temperature on Hydrogen Peroxide Solution in Water Khalid Al Sabeeh Ms. Dobrin 11-G Chemistry HL Jan 5, 2015 Abstract: Within this lab yeast was added to hydrogen peroxide solution in water. Temperature was the factor to be tested. In all trials, the initial and final, when yeast was added temperatures increased by 10˚C respectfully per trial.
CONCEPT OF SHELF-LIFE EXTENSION: Chitosan is a polymer which is extracted from chitin. It is natural, and thusly biodegradable and biocompatible. As a novel food preservative, chitosan offers the possibility to form edible film coatings on fresh or processed perishable foods in order to extend their shelf life. The chitosan film has antimicrobiological properties which allow it to protect the food it is coating.