Senior Seminars in Chemistry
Spring 2005


Seniors -- Spring 2005

(left to right) L. Mahoney, E. Rodriquez, J. Oliver, C. Bauer, M. Han, and (rear) Kenneth Carter (Alumni Speaker)

Seminar Abstracts & Other Information

1. DDT Controversy: Save Lives or Save the Environment

Carolyn Bauer

Although the use of 2,2-bis(p-chlorophenyl)1,1,1,trichlororethane, better known as DDT, was banned in the United States in 1972 it is still being used in many countries today.  Primarily, DDT is employed as a vector to combat the spread of Malaria.  Despite DDT’s revolutionary advances in insect control it has also been discovered to be an increasing environmental threat.  Should the use of DDT be continued in the fight against Malaria or are we overlooking the devastating effects that this serious insecticide is causing?

References:

1.            Roberts, D.R. et al. Perspectives.1997, 3, 295-303.

2.         Wolff M.S. Environmental Research. 1995, 84, 151-61.

3.         Curtis C.F. Parasitology Today. 2000, 16, 119-21.

2. A look at the high levels of arsenic concentration of ground water in Bangladesh

Jennifer Oliver

 High arsenic levels are causing massive health problems among the population such as arsenecosis and cancer. This poisoning has been named the worst mass poisoning in history with millions of people exposed. Arsenic has a high mobility in the environment, which can be attributed to its chemical characteristics. Possible methods of removal include chemical precipitation, ion exchange, adsorption, and membrane processes. All methods have specific problems and benefits, so choosing the best method is not always easy. Most methods are only effective in removing arsenate ion and so any arsenite ion be oxidized first. The most common method is chemical precipitation with aluminum or iron hydroxides. This treatment process consists of coagulation followed by flocculation, sedimentation and filtration. This process can, however, be costly, which is a big concern for the people of Bangladesh.

References:

1.            Environmental Protection Agency (December 2000). Technologies and Costs for Removal of Arsenic From Drinking Water  (EPA 815-R-00-028), Retrieved April 19, 2005.  http://www.epa.gov/safewater/arsenic.html

2.         Smith, Allan H.; Lingas, Elena O.; Rahman, Mahfuzar.  World Health Organization (2000).  Contamination of Drinking-Water by Arsenic in Bangladesh: A Public Health Emergency.  Retrieved April 17, 2005.          http://www.who.int/water_sanitation_health/dwq/arsenic/en/

3.            Caldwell, Bruce K., Caldwell, John C., S.N. Mitra, Smith, Wayne. Searching for an Optimum Solution to the Bangladesh Arsenic Crisis.  Accepted May 30, 2002.  Social Science and Medicine Volume 56 Issue 10, May 2003 pages 2089-2096

            www.elsevier.com/locate/socsimed

3. Statins: Cholesterol Preventing Drugs

Evan M. Rodriguez

 Statins are a class of terpine-based molecules that are primarily used in the pharmaceutical industry for the treatment of high cholesterol. Although the first statins were isolated from microorganisms, the newest statins are synthesized. The effect of statins is primarily due to it competitive inhibition of HMG-CoA Reductase, which is the enzyme in the rate-determining step of cholesterol synthesis. Recent research has shown that statins have potential anti-cancer effects. This may be a result of the reduction of GTP-Biding proteins, which are produced during the cholesterol biosynthesis pathway. GTP-Binding proteins are important to malignant function of cancer cells.

 References:

1.         Sleijfer, S., et al. (2004). “The Potential Of Statins: As Part of Anti-Cancer Treatment.” European Journal of Cancer. 41. 4, 516-522 

2.         http://en.wikipedia.org/wiki/Statin., last visited on May 2, 2005

3.         www.Pfizer.com, last visited on May 2, 2005

4.         Istvan, E. Et al. (2000). “Crystal Structure Of The Catalytic Portion 0f Human HMG-CoA Reductase: Insight Into Regulation of Activity and Catalysis.” The EMBO Journal, 19, 5, 819-830

  

4. Liquid Crystals

Mavis W. Han

 A Liquid Crystal Display (LCD) is a thin, lightweight display device with no moving parts. It consists of an electrically-controlled light-polarizing liquid trapped in cells between two transparent polarizing sheets. The polarizing axes of the two sheets are aligned perpendicular to each other. Each cell is supplied with electrical contacts that allow an electric field to be applied to the liquid inside.

References:

1.         Peter J. Collings, Liquid Crystals, 2nd ed. Princeton University Press, Princeton and Oxford. 2002

2.         Tatsuo Uchida and Takahiro Ishinabe, “Reflective Liquid Crystal Display,” MRS Bulletin, November 2002

3.         http://electronics.howstuffworks.com/lcd.htm

4.         http://www.elis.ugent.be/ELISgroups/lcd/lc/lc2.html

  

5. Environmental Remediation of Toxic Organic Compounds Employing Heterogeneous Catalysts

Luther Mahoney

In the wake of numerous reports of toxic chemicals evolving from household utilities, new generations of heterogeneous photocatalysts are being studied for environmental remediation of toxic indoor pollutants. These mesoporous photocatalyst powders form the MCM (Mobil Composition of Materials) family, which was discovered in 1992 by Mobil Oil Company researchers.  Currently, a transition metal doped MCM group of heterogeneous catalysts is being studied as catalysts for the photodegradation of toxic organic compounds such as acetaldehyde (CH3CHO). The presentation will primarily focus on the synthesis, characterization, and photocatalyst study of transition metal doped V-MCM-48 mesoporous powders. Furthermore, an extensive historical background of the MCM family of heterogeneous catalysts will be provided in the presentation with numerous possible applications.

References:

1.            Hoffmann, Michael R.; Martin, Scot T.; Choi, Wonyong; & Bahnemann, Detlef W.  “Environmental Applications of Semiconductor Photocatalysis,”Chemical Reviews, 1995, 95, 1, 70-96

2.            Linsebigler, Amy L.; Lu, Guangquan; & Yates Jr. John T. 

“Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results,” Chemical Reviews, 1995, 95, 3, 735-758

3.            Schumacher, Kai; Ravikovitch, Peter I.; Du Chesne, Alexander; Neimark, Alexander V.; & Unger, Klaus K.  “Characterization of MCM-48 Materials,” Langmuir, 2000, 16, 4648-4654

4.            Schumacher, Kai; du Fresne von Hohenesche, Cedric; Unger, Klaus K.; Ulrich, Ralph; Du Chesne, Alexander; Wiesner, Ulrich; & Spiess, Hans W. “The Synthesis of Spherical Mesoporous Molecular Sieves MCM-48 with Heteroatoms Incorporated into the Silica Framework,” Advanced Materials, 1999, 11, 14, 1194-1198

5.            Rodrigues, Shalini; Uma, S.; Martyanov, Igor N.; & Klabunde, K. J.  “Visible light induced photocatalytic activity for degradation of acetaldehyde using transition metal incorporated Al-MCM-41 (aluminum doped silica zeolitic material),” Journal of Photochemistry and Photobiology A: Chemistry, 2004, 165, 51-58