Physical Sciences and Mathematics Commons^™

Experiments In Aerobic And Anaerobic Biodegradation Of Trichloroethylene, Qiong Liao

Theses

The removal of trichloroethylene (TCE) from industrial waste has been intensively studied in recent years, Biodegradation has been determined to be an effective treatment for TCE in the environment. Many researchers have studied the biodegradation of TOE and obtained successful results based on the use of specific isolated bacteria. At the NJIT Biotechnology Laboratory, a new method is being developed in which immobilized activated sludge is used to degrade several toxic chemicals in various reactor configurations. The objective of this research is to determine if these methods can be extended to treat TCE.

Activated sludge from a wastewater treatment plant …

Low Pressure Chemical Vapor Deposition (Lpcvd) Of Silicon Carbide From Diethylsilane, Yi-Tong Shi

Theses

The depositions of amorphous and cubic-crystal SiC from a new chemical vapor deposition source, diethylsilane(DES), have been studied. Amorphous SiC thin films and crystalline cubic-SiC materials have been deposited on silicon wafers at temperature lower and higher than 850C, respectively. The activation energy and a reaction mechanism involving the production and subsequent desorption of diethylsilene has been suggested, which explains the observed deposition dependency with the temperature and reactor pressure. A model based on the polymerization of DES is offered and the deposition rate is found to be the result of a large number of simultaneously occuring deposition processes for …

Methods Development For Determination Of Trace Polar Volatile Organics In Environmental Samples, Qingchu Peng

Theses

The determination of trace levels of organic compounds in water samples is well developed for the less polar compounds, but the polar compounds are more difficult. The development of reliable and reproducible methods for such compounds as volatile alcohols and ketones is necessary if environmental monitoring is to be extended to these compounds.

The purge-and-trap method is frequently used for determination of volatiles in water samples. The method has problems when hydrophylic substances are being analyzed, since these are less easy to purge from the solution and more difficult to trap and desorb quantitatively. The high amount of water carried …

Preparation And Testing Of Novel Dental Adhesives Based On Bis- Gma/Tegdma Monomer System, Deyun Sun

Theses

In this study, polymerizable phosphonate adhesives synthesized from Diethylchloro-phosphate and 2-Hydroxyethylmethylacrylate and formulated with G-methacryloxy-propyltrimethoxy silane is used in Bis-GMA/TEGDMA monomer system. All the raw materials and finished products are characterized with infrared spectra, vapor pressure osmometry, viscosity and gel test. The bonding strength to tooth materials is determined by Instron machine. The work emphasizes applying polymeric organic phosphonate adhesive to Bis-GMA/TEGDMA monomer system and investigates the appropriate conditions for the crosslinking of Bis-GMA/TEGDMA monomer system. Average bonding strength of 744 psi to enamel and 600 to dentine are ob¬tained in comparision to 550 psi to enamel for phosphonate/silane/MMA/PMMA and …

Investigations Of Substitution Of Bi And Tl For Rare Earth Elements In Superconducting Rba2cu3oy, Jian Tang

Theses

Substitution of some other elements for rare earth or yttrium in high-T_c superconducting RBa₂Cu₃O_y compounds (R = Y, Nd, etc.) may improve chemical and physical properties of the materials, shed light on the superconducting mechanism of the new materials, and help to find new superconducting materials with even higher transition temperatures.

Bi³⁺ and Tl³⁺ have been reported earlier to result in higher T_c's in the related layer-structure compounds. The effect of electronegativity on superconductivity could be studied if substitution of Bi or Tl for Y or other rare earth elements …