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2010

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Articles 751 - 780 of 950

Full-Text Articles in Chemistry

Xanthene Carboxamides: Indicators For The Assay Of N-Buli And Etmgbr, Shekelia Baccus, M. Perry Davis Jr., David R. Magnin Jan 2010

Xanthene Carboxamides: Indicators For The Assay Of N-Buli And Etmgbr, Shekelia Baccus, M. Perry Davis Jr., David R. Magnin

Journal of the South Carolina Academy of Science

No abstract provided.


The Effects Of The Sumter Wastewater Treatment Plant On The Survival And Reproduction Of Ceriodaphnia Dubia In Chronic Toxicity Tests, Erin Worley, Pearl R. Fernandes, S. Michele Harmon, Jeff Steinmetz Jan 2010

The Effects Of The Sumter Wastewater Treatment Plant On The Survival And Reproduction Of Ceriodaphnia Dubia In Chronic Toxicity Tests, Erin Worley, Pearl R. Fernandes, S. Michele Harmon, Jeff Steinmetz

Journal of the South Carolina Academy of Science

No abstract provided.


Associative Learning In Larval Dosophila Melanogaster: The Role Of Heredity In Learning Speed And Persistence Of Leaning Into Adulthood, Jasmin Hicklen, Domonique Jones, Michelle Vieyra Jan 2010

Associative Learning In Larval Dosophila Melanogaster: The Role Of Heredity In Learning Speed And Persistence Of Leaning Into Adulthood, Jasmin Hicklen, Domonique Jones, Michelle Vieyra

Journal of the South Carolina Academy of Science

No abstract provided.


Studies Toward The Total Synthesis Of (±)-Α-Yohimbine By Double Annulation, Raghu Ram Chamala Jan 2010

Studies Toward The Total Synthesis Of (±)-Α-Yohimbine By Double Annulation, Raghu Ram Chamala

University of Kentucky Doctoral Dissertations

The indole alkaloids, a class of natural products, have received much synthetic attention for years due to their diverse structures and interesting biological properties. We are particularly interested in synthesizing some of the yohimbine alkaloids extracted from the bark of a tall evergreen African tree (Corynanthe yohimbe, commonly known as fringe tree). Yohimbine and its stereoisomers have been tempting targets for synthetic organic chemists for more than fifty years. These compounds feature a pentacyclic ring system with two heteroatoms and five stereogenic centers.

Broadly, the fifteen different synthetic approaches that led to the successful completion of yohimbine alkaloids …


Contact Angle Of A Nano-Drop On A Heterogeneous Surface, John Ritchie Jan 2010

Contact Angle Of A Nano-Drop On A Heterogeneous Surface, John Ritchie

Theses and Dissertations

CONTACT ANGLE OF A NANO-DROP ON A HETEROGENEOUS SURFACE By John Andre Ritchie, Master of Science A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University Virginia Commonwealth University, 2010 Major Director: Dr. Alenka Luzar, Professor of Chemistry

We examine the relation between contact angle of a nanodrop of water and the location of surface-water interaction energy at the perimeter and beneath the drop. Young’s equations gives the relationship between surface tension, at the three phase solid liquid vapor interface, and contact angle on a homogeneous surface. Cassie and Baxter …


15N Solid-State Nmr Detection Of Flavin Perturbation By H-Bonding In Models And Enzyme Active Sites, Dongtao Cui Jan 2010

15N Solid-State Nmr Detection Of Flavin Perturbation By H-Bonding In Models And Enzyme Active Sites, Dongtao Cui

University of Kentucky Doctoral Dissertations

Massey and Hemmerich proposed that the different reactivities displayed by different flavoenzymes could be achieved as a result of dominance of different flavin ring resonance structures in different binding sites. Thus, the FMN cofactor would engage in different reactions when it had different electronic structures. To test this proposal and understand how different protein sites could produce different flavin electronic structures, we are developing solid-state NMR as a means of characterizing the electronic state of the flavin ring, via the 15N chemical shift tensors of the ring N atoms. These provide information on the frontier orbitals. We propose that …


Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima, Matthew S. Luchansky, Bryan S. Der, Sabato D'Auria, Gabriella Pocsfalvi, Luisa Iozzion, Daniela Marasco, Jonathan D. Dattelbaum Jan 2010

Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima, Matthew S. Luchansky, Bryan S. Der, Sabato D'Auria, Gabriella Pocsfalvi, Luisa Iozzion, Daniela Marasco, Jonathan D. Dattelbaum

Chemistry Faculty Publications

Members of the periplasmic binding protein superfamily are involved in the selective passage of ligands through bacterial cell membranes. The hyperthermophilic eubacterium Thermotoga maritima was found to encode a highly stable and specific periplasmic arginine-binding protein (TM0593). Following signal sequence removal and overexpression in Escherichia coli, TM0593 was purified by thermoprecipitation and affinity chromatography. The ultra-stable protein with a monomeric molecular weight of 27.7 kDa was found to exist as both a homodimer and homotrimer at appreciable concentrations even under strongly denaturing conditions, with an estimated transition temperature of 116 °C. Its multimeric structure may provide further evidence of …


Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima. 2. Molecular Organization And Structural Stability, Andrea Scirè, Anna Marabotti, Maria Staiano, Luisa Iozzion, Matthew S. Luchansky, Bryan S. Der, Jonathan D. Dattelbaum, Fabio Tanfani, Sabato D'Auria Jan 2010

Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima. 2. Molecular Organization And Structural Stability, Andrea Scirè, Anna Marabotti, Maria Staiano, Luisa Iozzion, Matthew S. Luchansky, Bryan S. Der, Jonathan D. Dattelbaum, Fabio Tanfani, Sabato D'Auria

Chemistry Faculty Publications

ABC transport systems provide selective passage of metabolites across cell membranes and typically require the presence of a soluble binding protein with high specificity to a specific ligand. In addition to their primary role in nutrient gathering, the binding proteins associated with bacterial transport systems have been studied for their potential to serve as design scaffolds for the development of fluorescent protein biosensors. In this work, we used Fourier transform infrared spectroscopy and molecular dynamics simulations to investigate the physicochemical properties of a hyperthermophilic binding protein from Thermotoga maritima. We demonstrated preferential binding for the polar amino acid arginine …


Tuning Σ-Holes: Charge Redistribution In The Heavy (Group 14) Analogues Of Simple And Mixed Halomethanes Can Impose Strong Propensities For Halogen Bonding, Kelling J. Donald, Bernard K. Wittmaack, Chad Crigger Jan 2010

Tuning Σ-Holes: Charge Redistribution In The Heavy (Group 14) Analogues Of Simple And Mixed Halomethanes Can Impose Strong Propensities For Halogen Bonding, Kelling J. Donald, Bernard K. Wittmaack, Chad Crigger

Chemistry Faculty Publications

Halogen bonding between halide sites (in substituted organic molecules or inorganic halides) and Lewis bases is a rapidly progressing area of exploration. Investigations of this phenomenon have improved our understanding of weak intermolecular interactions and suggested new possibilities in supramolecular chemistry and crystal engineering. The capacity for halogen bonding is investigated at the MP2(full) level of theory for 100 compounds, including all 80 MH4-nXn systems (M = C, Si, Ge, Sn, and Pb; X = F, Cl, Br, and I). The charge redistribution in these molecules and the (in)stability of the σ-hole at X as …


Non-Portland Cement Activation Of Blast Furnace Slag, Anne Elizabeth Oberlink Jan 2010

Non-Portland Cement Activation Of Blast Furnace Slag, Anne Elizabeth Oberlink

University of Kentucky Master's Theses

The purpose of this project was to produce a “greener” cement from granulated ground blast furnace slag (GGBS) using non-Portland cement activation. By eventually developing “greener” cement, the ultimate goal of this research project would be to reduce the amount of Portland cement used in concrete, therefore reducing the amount of carbon dioxide emitted into the atmosphere during cement production.

This research studies the behavior of mineral binders that do not contain Portland cement but instead comprise GGBS activated by calcium compounds or fluidized bed combustion (FBC) bottom ash. The information described in this paper was collected from experiments including …


Synthesis, Characterization, Electrochemistry And Biological Properties Of Schiff Bases And Their Metal Complexes., Zuraini Kadir Jan 2010

Synthesis, Characterization, Electrochemistry And Biological Properties Of Schiff Bases And Their Metal Complexes., Zuraini Kadir

Student Works (2010-2019)

A series of new indole hydrazone Schiff bases and their metal complexes have been synthesized, characterized and evaluated for anti-ulcerogenic activity.The Schiff bases derived from indole-3-acetic acid hydrazide and 2-hydroxyacetophenone and their zinc(II), nickel (II) and copper complexes were synthesized by condensation in ethanol. The IR, 1H and 13C NMR, UV Visible data indicate that the hydrazone ligands are coordinated to zinc metal. Indole hydrazones coordinated to zinc(II), nickel(II) and copper(II) metals as dimer ligands. The IR spectrum of the free ligand indicates that in solid state the ligand remains in the keto form. Recrystallization of ligand and complex 5-methyl-2-hydroxyacetophenone …


Characteristics Of Proton Conducting Pva-Chitosan Polymer Blend Electrolytes., Mohd Fakhrul Zamani Abdul Kadir Jan 2010

Characteristics Of Proton Conducting Pva-Chitosan Polymer Blend Electrolytes., Mohd Fakhrul Zamani Abdul Kadir

Student Works (2010-2019)

The main focus of this present work is to build a good conducting solid polymer electrolyte (SPE) based on chitosan and poly(vinyl alcohol)(PVA) blend. Solution cast technique has been employed to produce sample films in this work. From the scanning electron micrographs (SEM) the surface morphology of the blend containing 40 wt.% chitosan and 60 wt.% PVA (C4P6) is homogenous and miscible in one and another. The C4P6 film is the most amorphous and is the best candidate for the polymer host in the electrolyte systems studied in the present work. Ammonium Nitrate (NH4NO3) is the doping salt that provides …


Electrodeposition Of Tin Using Tin (Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid., Yang Kok Kee Jan 2010

Electrodeposition Of Tin Using Tin (Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid., Yang Kok Kee

Student Works (2010-2019)

The electrodeposition of tin from Tin(II) Methane Sulfonate (MSA) with varying concentration in air and water stable 1-butyl-1-methyl-pyrrolidinium trifluoromethanesulfonate, (BMPOTF) ionic liquid at room temperature was studied. Cyclic Voltammetry served to characterize the electrochemical behavior of tin reduction and oxidation. The diffusion coefficient of stannous ions in the mixture of BMPOTF ionic liquid and MSA based electrolyte obtained via Randles-Sevcik and Cottrell equation was 2 × 10-7 cm2/s. Electroplating on copper panel was conducted under different current densities to determine BMPOTF based tin plating solution current efficiency. Mixture of BMPOTF and MSA based tin plating solution gave current efficiency as …


The Thermal Characteristic Of Imipenem Encapsulated In Low And High Molecular Weight Of Polyethylene Glycol., Abdul Aziz Ismail Jan 2010

The Thermal Characteristic Of Imipenem Encapsulated In Low And High Molecular Weight Of Polyethylene Glycol., Abdul Aziz Ismail

Student Works (2010-2019)

Microencapsulation technique is widely used in pharmaceutical industries to control the release of a drug. Biodegradable polymer such as Polyethylene glycol (PEG) is frequently used as encapsulation material. This study has tried to produce microencapsulation product of Imipenem antibiotics in Polyethylene Glycol.Commercially available product called Tienam® was used as a major source of Imipenem. We used freeze-drying method to produce the microencapsulation products. The successful of producing of this product is confirmed by the yellowish appearance of the product whereby it shows the colour properties of Tienam® Thermal analysis using Differential Scanning Calorimeter (DSC) was used to characterize pure materials …


Application Of Solid-Phase Microextraction For The Analysis Of Polycyclic Aromatic Hydrocarbons In Hyophila Involuta As A Natural Biosensor., Elizabeth Fong Yew Mei Jan 2010

Application Of Solid-Phase Microextraction For The Analysis Of Polycyclic Aromatic Hydrocarbons In Hyophila Involuta As A Natural Biosensor., Elizabeth Fong Yew Mei

Student Works (2010-2019)

This work describes a simple and rapid extraction method by using solid-phase microextraction (SPME) technique for the determination of polycyclic aromatic hydrocarbons (PAHs) from mosses of Hyophila involuta which is found commonly and abundantly throughout Peninsular Malaysia. Mosses have been chosen in our study since they are effective bioindicators as they take up nutrients and pollutants directly from the atmosphere and they have no root system. These properties make them ideal for evaluating pollutant levels in the air over a monitored period of time. This study has been developed and optimized based on the extraction of the analytes of interest …


Studies Of Antioxidant Activity Of Bioactive Compounds Derived From Ardisia Crispa., Hassan Mahmood Kzar Jindal Jan 2010

Studies Of Antioxidant Activity Of Bioactive Compounds Derived From Ardisia Crispa., Hassan Mahmood Kzar Jindal

Student Works (2010-2019)

In recent times, researches have focused on medicinal plants in order to extract natural and low cost antioxidants that can help protect the human body against oxidative stress, and replace the synthetic additives that might be carcinogenic. In present study, the crude extracts of leaves and fruits from Ardisia crispa were investigated for their chemical constituents and antioxidant activity. Preliminary phytochemical screening of the crude extracts via TLC analysis revealed the presence of several secondary compounds mainly, terpenoids and phenolic compounds in addition to alkaloids and saponins. HPLC analysis showed the possibility of presence of gallic acid in the fruits …


Synthesis Of Urethane Acrylate Macromer From Palm Oil-Based Polyol And Its Application As A Resin For Dental Composite., Fadhel A. A. Alsanabani Jan 2010

Synthesis Of Urethane Acrylate Macromer From Palm Oil-Based Polyol And Its Application As A Resin For Dental Composite., Fadhel A. A. Alsanabani

Student Works (2010-2019)

A slightly branched urethane acrylate macromer (UAM) was synthesized by reacting palm oil-based polyol with excess amounts of polymeric methylene diphenyl diisocyanate (MDI) to form urethane prepolymer, then reacted with 2-hydroxyethyl methacrylate (HEMA) and FT-IR spectroscopy confirmed the urethane and grafted acrylate groups. 0.2% by weight of camphoroquinone (CQ) and 0.8% by weight of ethyl-4-N,N-dimethylamino-benzoate (4EDMAB) by weight were added to render the experimental resins light-curable. Their viscosity, percentage of degree of conversion (%DC) and cross-linking density (CLD), percentage of volumetric polymerization shrinkage (%VPS), water sorption and solubility, flexural strength, modulus of elasticity and toughness were determined and compared to …


Synthesis And Characterization Of Zinc Oxide Nanostructures., Khalifa Said Zahran Al-Azri Jan 2010

Synthesis And Characterization Of Zinc Oxide Nanostructures., Khalifa Said Zahran Al-Azri

Student Works (2010-2019)

The growth mechanism, morphology, structure and optical properties of the ZnO nanostructures grown on bare and gold-coated silicon substrates using carbothermal reaction at atmospheric pressure were investigated under different growth conditions. The ZnO nanostructures formed were studied as a function of substrate location, furnace temperature, Ar gas flow rate, deposition time and ZnO powder to carbon powder mass ratio. The morphology and structure of the samples were characterized using the fieldemission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy(EDX) spectrum, x-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). It was found that in both silicon and gold-coated silicon …


Thermo-Electrical And Mechanical Studies On Polymer-Organically Modified Montmorillonite Composite., Norhana Abdul Halim Jan 2010

Thermo-Electrical And Mechanical Studies On Polymer-Organically Modified Montmorillonite Composite., Norhana Abdul Halim

Student Works (2010-2019)

The field of polymer-nanoclay composite has attracted a lot of attention in materials studies due to the dramatic improvement on polymers characteristics. For example mechanical and thermal properties, chemical resistance as well as the reduced gas permeability. However, structural changes and the mechanisms that may contribute to these improvements are not fully understood. In this work, the study on polymer nanoclay composite concentrates on the effects of OMON inclusion within different polymer matrix systems. The matrixes are a series of natural rubbers (Standard Malaysia Rubber – Latex grade (SMRL); Deproteinized Natural Rubber (DPNR) and Epoxidized Natural Rubber (ENR-50)), plasticized Polyvinyl …


Chemical Constituents Of Aglaia Lanuginose. King, Fadzly Adzhar Kamarulzaman Jan 2010

Chemical Constituents Of Aglaia Lanuginose. King, Fadzly Adzhar Kamarulzaman

Student Works (2010-2019)

Aglaia is a small genus of trees that belong to the family Meliaceae. They are widely distributed in India, Malay Peninsula and throughout Indomalesia. The chemistry of Aglaia has been extensively investigated and most of the researches done on these plants focused on their effect as insecticides, antifeedant, growth inhibitors, cytotoxicity and others. The dichloromethane extract from the bark of Aglaia lanuginose were studied. The chromatographic separation on both of the extracts gave ten compounds. The compounds isolated were identified as eichlerialactone 102, methyl eichlerianate 103, cabraleone 104, ocotillone 105, 4-hydroxycinnamyl acetate 106, cabralealactone 107, eichlerianic acid 108, shoreic acid …


Synthesis, Characterization And Biological Activities Of Some Indole Derivatives And Their Metal Complexes., Mohamed Mustafa Mohamed Ibrahim Jan 2010

Synthesis, Characterization And Biological Activities Of Some Indole Derivatives And Their Metal Complexes., Mohamed Mustafa Mohamed Ibrahim

Student Works (2010-2019)

Tryptamine (1H-indole-3-ethyleneamine) Schiff bases were prepared by the condensation reaction of ethanolic solution of tryptamine with: salicylaldehyde (TS), 5 chlorosalicylaldehyde (TCS), 5-nitrosalicylaldehyde (TNS), 3,5-di-tert-butyl-2-hydroxy benzaldehyde (TTET) and the ketones: 2-hydroxyacetophenone (THAP), 5-methyl-2- hydroxyacetophenone (TMeHAP), 5-methoxy-2 hydroxyacetophenone (TOMeHAP), 5- chloro-2-hydroxyacetophenone (TClHAP) and 5-bromo-2 hydroxyacetophenone (TBrHAP). The ligands were coordinated to Zn(II), Cu(II) and Ni(II) by the reaction of metal acetates with the corresponding ligand in a 1 : 2 metal to ligand ratio. The solid products formed were collected, washed with ethanol and recrystallized from a suitable solvent. All the ligands and complexes prepared have been characterized by spectroscopic methods using …


Optimization Of Solid-Phase Microextraction For The Determination Of Organo-Phosphorus And Organo-Chlorine Pesticide Residues In Natural Water Near Aquaculture Farms., Chan Chun Foong Jan 2010

Optimization Of Solid-Phase Microextraction For The Determination Of Organo-Phosphorus And Organo-Chlorine Pesticide Residues In Natural Water Near Aquaculture Farms., Chan Chun Foong

Student Works (2010-2019)

The global shrimp farming industry had a rapid growth in the 1980s due to the high demand for shrimp. Apart from the destruction of mangroves and wetlands, the intensive operation of shrimp aquaculture deteriorated the water quality in the region. Variety of chemicals and biological products were used to prevent the outbreaks of diseases in the intensively managed shrimp ponds. Pesticides were used as disinfectands to kill unwanted organisms in the pond. SPME-GC-ECD method was developed for the determination of azinphos-ethyl, chlorphyrifos-methyl, diazinon, dichlorvos, endosulfan-I, endosulfan-II, endosulfan sulfate and malathion from water samples of shrimp aquaculture area in Manjung district, …


Electrical And Structural Studies Of Polyacrylonitrile (Pan) Complexed With Inorganic Salts., Khairul Bahiyah Md Isa Jan 2010

Electrical And Structural Studies Of Polyacrylonitrile (Pan) Complexed With Inorganic Salts., Khairul Bahiyah Md Isa

Student Works (2010-2019)

In the present study, polymer electrolyte films composed of polyacrylonitrile (PAN) as a host polymer, ethylene carbonate (EC) as the plasticizer and lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3) as dopant salts were prepared by the solution cast technique. Five systems of polymer electrolytes films have been prepared; these systems are the plasticized-PAN system i.e. PAN-EC system, two salted-PAN systems i.e. PAN-LiCF3SO3 and PAN-NaCF3SO3, and two plasticized-salted PAN systems i.e. PAN-EC-LiCF3SO3 and PAN-EC-NaCF3SO3. The pure PAN film was prepared as a reference. The ionic conductivity for each system is characterized using impedance spectroscopy. The room temperature conductivity of the pure …


The Thermoluminescence Properties Of Manganese Doped Zns Nanophosphor., Khalid Humaid Zahir Al-Hinai Jan 2010

The Thermoluminescence Properties Of Manganese Doped Zns Nanophosphor., Khalid Humaid Zahir Al-Hinai

Student Works (2010-2019)

The thermoluminescence (TL) properties of Manganese (Mn) doped ZnS nanophosphors were investigated after gamma irradiation at room temperature. The ZnS:Mn nanophosphors were prepared by chemical precipitation method by using Zinc sulfate, Sodium sulfide and Manganese sulfate. 1 mole, 2 moles and 3 moles of Manganese sulfate were used to have different concentrations of Mn in doped ZnS. The formation of the nanophosphors was characterized by high resolution scanning electron microscopy FESEM, XRD and EDX. The obtained products consist of particles with the dimension about 85–150nm. Comparison between ZnS nanophosphors and commercial ZnS powder glow curves was studied. It was observed …


Synthesis Of Chromium-Based Ziegler-Natta Catalysts And Thier Application In Ethylene Polymerization And Copolymerization., Wong Jun Xuan Jan 2010

Synthesis Of Chromium-Based Ziegler-Natta Catalysts And Thier Application In Ethylene Polymerization And Copolymerization., Wong Jun Xuan

Student Works (2010-2019)

Four chromium-based oxo-trinuclear carboxylate complexes were prepared by reacting Cr(NO3).9H2O with acetic acid and substituted carboxylic acids to produce [Cr3O(CH3COO)6.3H2O]NO3.7H2O,[Cr3O(ClCH2COO)6.3H2O]NO3.3H2O, [Cr3O(Cl2CHCOO)6.3H2O]NO3.H2O and [Cr3O(Cl3CCOO)6.3H2O]NO3.2H2O, which alysis (TGA).Chromium content in each complex was determined by titrimetry method and the result was in good agreement with that from TGA. Chromium(III)monochloroacetate complex[Cr3O(ClCH2COO)6.3H2O]NO3.3H2O in combination with diethylaluminium chloride formed heterogeneous catalyst system for ethylene polymerization and ethylene-propylene copolymerization. Both Al/Cr ratio and temperature influenced the catalytic activity. The maximum activity of ethylene polymerization was 1768 gPE/gCr/hr/atm, achieved by polymerizing ethylene at 29°C with Al/Cr ratio 30.8. Effect of chloro-substituent groups on carboxylic ligand was studied …


Synthesis, Characterization And Biological Activities Of Three Indole Schiff Bases And Their Copper And Nickel Complexes., Nazzatush Shimar Jamaludin Jan 2010

Synthesis, Characterization And Biological Activities Of Three Indole Schiff Bases And Their Copper And Nickel Complexes., Nazzatush Shimar Jamaludin

Student Works (2010-2019)

Three derivatives of indole-3-carboxaldehyde with indole-3-acetic hydrazide and their copper(II) and nickel(II) complexes were synthesized. The Schiff base compounds were varied on the substituent where each compound holds a hydrogen, chlorine and bromine atom on the 5th position of indole-3-carboxaldehyde. The structures of the ligands and their complexes were elucidated by various characterization methods. All compounds were screened for their biological effects on neuroprotective screening (in vitro), acute toxicity test (in vivo), ethanol-induced gastric ulcer (anti-ulcer) and glucose tolerance test (antidiabetic). All compounds except bromine-containing compounds were not dose dependent while compounds with bromine displayed significant results, acting as inhibitory …


Chemical Constituents Of Cryptocarya Densiflora., Nurul Nazneem Wan Othman Jan 2010

Chemical Constituents Of Cryptocarya Densiflora., Nurul Nazneem Wan Othman

Student Works (2010-2019)

The extraction of alkaloids from the Malaysian Cryptocarya densiflora has been carried out in this study. The alkaloids were extracted from the bark and leaves of this species using acid base extraction and the crude alkaloids obtained were subjected to extensive chromatographic techniques such as thin layer and column chromatography. The structural elucidation of the purified alkaloids were performed with the aid of spectroscopic methods i.e. 1H NMR, 13C NMR, 2D NMR, IR, UV and LCMS. Investigation of the alkaloidal content from the bark of Cryptocarya densiflora afforded six alkaloids and their structures were elucidated as laurotetanine 63, isocaryachine 64, …


New Palm Oil Products By Enzymatic Interesterification And Dry Fractionation., Saw Mei Huey Jan 2010

New Palm Oil Products By Enzymatic Interesterification And Dry Fractionation., Saw Mei Huey

Student Works (2010-2019)

Palm olein is one of the major palm oil products that domestically and industrially used as cooking or frying oil. Palm olein tends to crystallize at low temperature that limits its usage in temperate countries. In spite of various nutritional studies, palm olein is also not well considered as recommended choice due to its higher saturation content. Against these factors, there is a need to reduce its saturation content. In this study, the saturation content in palm olein was reduced through the combination of enzymatic interesterification and dry fractionation. Enzymatic interesterification allows interchanging of acyl groups between and within triacylglycerols …


Synthesis, Characterization And Electrochemical Studies Of Cu(Ii), Fe(Ii), Fe(Iii) And Ni(Ii) Complexes Of Someo-Phenylenediamine Schiff Bases., Abdulaziz Ali Alomari Jan 2010

Synthesis, Characterization And Electrochemical Studies Of Cu(Ii), Fe(Ii), Fe(Iii) And Ni(Ii) Complexes Of Someo-Phenylenediamine Schiff Bases., Abdulaziz Ali Alomari

Student Works (2010-2019)

Four Schiff base ligands, N,N’-1,2-benzene-1,2-diyl-bis(5-chlorosalicylideneimine) (H2L1), N,N’-1,2-benzene-1,2-diyl-bis(4-bromosalicylideneimine) (H2L2), N,N’-1,2- benzene-1,2-diyl-bis(4-hydroxysalicylideneimine) (H2L3), and N,N’-1,2-benzene-1,2-diyl-bis(3-bromo-5-chlorosalicylideneimine) (H2L4) were obtained in good yields from the condensation reaction of o-phenylenediamine with 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, 4-hydroxysalicylaldehyde and 3-bromo-5-chlorosalicylaldehyde respectively. These Schiff bases formed complexes with copper(II), iron(II) and nickel(II) ions in good yields. The structures of these complexes are mainly square planar, which is confirmed by the crystal structure of nickel(II) complex of bis-N,N’-3-chloro-5-bromosalicylideneamine-,2-diaminobenzene. Attempts to prepare the corresponding iron(III) complexes were unsuccessful. The ligands were characterized by Fourier transform infrared spectroscopy, elemental analysis, 1H-Nuclear magnetic resonance spectroscopy and UV-vis spectroscopy, while the complexes were characterized by …


Synthesis And Characterization Of Silicon Oxide And Silicon Carbide Nanostructures., Majid Salim Mohammed Al-Ruqieshi Jan 2010

Synthesis And Characterization Of Silicon Oxide And Silicon Carbide Nanostructures., Majid Salim Mohammed Al-Ruqieshi

Student Works (2010-2019)

Silicon oxide nanostructures have attracted extensive interests in recent years due to their physical and optical properties. SiOx nanostructures are synthesized by catalytic and non-catalytic approaches. With catalytic approach, long and uniform amorphous silicon oxide nanowires, nanofibers (comet and tree like), nanocakes and nanocages were synthesized on Si substrate by carbothermal evaporation reactions of TiO2 at high temperature. The SiOx nanowires were about 13 nm to 243 nm in diameters and 194 nm to several microns in length and the nanofibres with diameter between 8 nm to 30 nm and around 50 nm to 2.5μm in length. The diameter and …