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Full-Text Articles in Chemistry
Solid Phase Extraction Of Pesticides With Determination By Gas Chromatography, Anwar A. Bhuiyan, Harry O. Brotherton
Solid Phase Extraction Of Pesticides With Determination By Gas Chromatography, Anwar A. Bhuiyan, Harry O. Brotherton
Journal of the Arkansas Academy of Science
A simple, rapid, and effective method for the extraction of fifteen organochlorine and organophosphorus pesticides based on the use of solid phase Bond Elut C-18 cartridges was studied as an alternative method to those based on extraction with organic solvents. Solid phase extraction is an attractive chromatographic sample preparation technology that reduces analysis time, costs, labor, and solvent consumption relative to traditional liquid/liquid extraction methods. The sample recoveries with the use of solid phase extractions were excellent for most pesticides. Analyte concentration by a factor as great as 1000-fold was achieved readily. The adsorbed pesticides were eluted from the solid …
Reduction Of Dendrite Formations To Improve The Appearance Of The Powder Cured Films For Automotive Industry, Alexandru S. Biris, C. U. Yurteri, Malay K. Mazumder, Robert A. Sims, P. H. Williams
Reduction Of Dendrite Formations To Improve The Appearance Of The Powder Cured Films For Automotive Industry, Alexandru S. Biris, C. U. Yurteri, Malay K. Mazumder, Robert A. Sims, P. H. Williams
Journal of the Arkansas Academy of Science
The appearance of powder-coated films is dependent upon powder chemistry and spraying parameters. One of the most important physical factors controlling the powder film appearance is the microdeposition of the powder particles on the grounded substrate. During the electrostatic deposition of powder, the formation of dendrites and agglomerates was observed; these formations have an adverse effect on the final film appearance and their elimination may result in smoother and glossier films. Dendrites are generated due to bipolar charging and inter-particulate electrostatic attractive forces. The corona charging technique is mostly used in industrial powder coating applications. At low corona voltages (- …
Electrostatic Microencapsulation Of Composite Particulate Materials For Manufacturing And Environmental Applications, S. De, M. Pritchett, Malay K. Mazumder, Robert A. Sims, C. U. Yurteri, Alexandru S. Biris, A. Rego
Electrostatic Microencapsulation Of Composite Particulate Materials For Manufacturing And Environmental Applications, S. De, M. Pritchett, Malay K. Mazumder, Robert A. Sims, C. U. Yurteri, Alexandru S. Biris, A. Rego
Journal of the Arkansas Academy of Science
Electrostatic microencapsulation is a dry coating process where two powders, one containing the fines and the other relatively larger particles, are separately dispersed in air and pre-charged with opposite polarity, using corona charging for electrostatic coagulation. These oppositely charged core and guest particles experience attractive electrostatic forces and generate composite particles. Preliminary experiments of electrostatic microencapsulation were performed using Anionic Exchange Resin (AG 1-X8) as the host particle and Red Toner (Omega 4000) as the guest particles. An electrostatic microencapsulation tower has been designed for generation of composite particles using particles of different particle size distribution.
Chemical Composition Of Particles Of D < 0.20 Mu In The Lower Stratospheric Aerosol, Spring 1993, Joseph D. Scott, David M. Chittenden Ii
Chemical Composition Of Particles Of D < 0.20 Mu In The Lower Stratospheric Aerosol, Spring 1993, Joseph D. Scott, David M. Chittenden Ii
Journal of the Arkansas Academy of Science
The majority of the mass of stratospheric aerosol collected during the spring of 1993 consisted principally of particles of d >0.20 mu containing a mixture of H2SO4 and (NaK)2SO4. However, the composition of the more numerous particles with d< 0.2 mu was very different. X-ray emission spectra (EDS) of individual particles indicated that there were three different chemical populations of small particles. The most numerous population was almost all C with only traces of S and Na. The second population contained metal sulfates and chlorides, possibly accreted to a C-containing matrix. The third population consisted of S- and Cl- containing species and trace amounts of Na and K ions. The number of equivalents of metal ion was much less than that of S and Cl species, indicating that most of the S and Cl was not ionic, but was covalently bonded, perhaps to a C matrix.
Modification Of Surface Properties Of Polymeric Materials, Rajesh Sharma, Robert A. Sims, Malay K. Mazumder
Modification Of Surface Properties Of Polymeric Materials, Rajesh Sharma, Robert A. Sims, Malay K. Mazumder
Journal of the Arkansas Academy of Science
Polymeric materials are successfully used in virtually all industries ranging from semiconductors, and coatings, to household appliances, automotive, and biomedical implants. Polymers generally have excellent bulk physical and chemical properties. However, certain properties of polymers such as low surface energy, low wettability, and high electrical resistivity sometimes limit their applications. Changing the bulk formulation of the polymers can alter some of these properties, but in general this is not acceptable as it can affect "desirable" bulk properties. Surface modification techniques have been used to alter polymer surfaces without affecting the bulk properties of the material. Most polymers have very high …
Alumina And Synthesis Intermediates Derived From Diethylkaluminum Amide, Benzaldehyde And Water, Stephen E. Hall, Lize Wilcox, William S. Tyree, David A. Lindquist, Malay K. Mazumder
Alumina And Synthesis Intermediates Derived From Diethylkaluminum Amide, Benzaldehyde And Water, Stephen E. Hall, Lize Wilcox, William S. Tyree, David A. Lindquist, Malay K. Mazumder
Journal of the Arkansas Academy of Science
The reaction of diethylaluminum amide [Et2AINH2] with benzaldehyde in toluene produces a solution of ethylaluminoxane polymer [EtAlO] and hydrobenzamide [PhCH=NCH(Ph)N=CHPh]. Alumina then is precipitated by the addition of water. Transition aluminas that may be useful in heterogeneous catalyst applications are obtained after calcining. Details of the chemistry of solution intermediates according to 1H NMR and the properties of the alumina product according to surface area analyses and powder x-ray diffraction are described.