Abstract The paper explains what chromium is, where it can be found and what its basic uses are.The paper also explains its advantages and disadvantages. In addition, the paper gives a case study in order to illustrate environmental exposure to public residence.
Outline:
Chromium Chromium health
Toxic effect
Protection and Sampling
Industrial use
Environmental Exposure
Case study
Diagnosis Tests
Distribution of Chromium Treatment
From the Paper "'Environmental hazards are rare these days because environmental regulations but they do occur. To illustrate environmental chromium exposure to public residence I will review a case study of a chromate-processing facility. When the waste from chromate-processing facilities is not disposed of properly, leaching from the topsoil and rocks allows it to enter bodies of water. Those that live near a chromate production facility can be exposed by airborne particulate through inhalation and by solution through ingestion if it seeps into their drinking water."
Abstract The paper evaluates some of the predominant methods of remediation of chromium contaminated sites. The paper notes that the methods employed are divided into two types: removal from the soil (in which various chemical extractants are used to flush chromium from the site) or immobilization in the soil (in which reducing agents are used to break down dangerous forms of chromium). The paper examines several of the more promising methods of remediation currently being employed, and concludes with a discussion and analysis of the methods in terms of their real-world applicability.
From the Paper " Chromium contamination, especially contamination of Cr(VI), is a significant environmental hazard. It will have a significant effect on the quality of the soil and the quality of the groundwater. Because of this, it is very important that effective and practical remediation techniques be developed that can chemically remove or immobilize the presence of chromium at the site. After briefly examining some of the methods currently being developed, which can be roughly divided into extractive versus immobilization techniques, there seems to be demonstrable promise in the possibility of cleaning up chromium-contaminated sites."
Abstract This paper explains that, if the corrosion on aircraft is undetected or untreated, corrosion problems can lead to structural failures and, hence, pose a great safety risk. The author points out that the most popular method of corrosion prevention is the use of chromate surface treatments of the aluminum structures; however, using hexavalent-chromium compounds for surface coating is an environmentally unsound practice because chromium is well-known as a highly toxic and carcinogenic agent. The paper relates that tackling corrosion at the designing and manufacturing phase is key to successful control of the corrosion menace; proper maintenance also occupies a significant role in remedying the damage and in prolonging the life of the aircraft.
Table of Contents
Introduction
Corrosion Problem
Corrosion Control (A Design and Manufacturing Issue)
Corrosion Control by Coating
Maintenance Programs
Conclusion
From the Paper "Cervical corrosion occurs when a corrosive fluid gets inside the joints or penetrates the coated surface. Both the forms of corrosion are dangerous and can result in cracking of the metal surface. The problem is more pronounced in aging aircrafts which are exposed to corrosive materials over a long period of time. The 1988 Aloha Airline B-737-200 incident was an eye opener to the dangers of corrosion. Due to undetected corrosion the whole fuselage of the plane got separated in mid air. This incident led to the formation of the "Aging Aircraft Task Force Steering Committee" which is currently known as the "Airworthiness Assurance Working Group"."
A discussion on the different types of emeralds, vis-a-vis its chemicals, texture, temperature conditions and significance in society since ancient times.
792 words (approx. 3.2 pages), 4 sources, 2002, $ 28.95
Abstract This paper traces the history of emeralds from ancient Egypt, to 18th century to today's mining areas in Columbia, Zimbabwe, Zambia. It discusses the different types of emeralds, the treatments for the stone, colors, textures, healing attributes and gemstones.
From the Paper "To the ancient Egyptians, the emerald's green color stood for fertility and rebirth. The gemstone was used to treat eye diseases. The Greeks worked the Egyptian mines during the time of Alexander the Great and throughout the Ptolemaic Dynasty. ?The Greeks regarded the emerald as the sacred stone of the goddess Venus and of the Earth Goddess.? (Emeralds!) "
