Jade Jung - Academia.edu (original) (raw)

Papers by Jade Jung

Metals and Materials, 1998

Cu-TiB2 composite has been manufactured by spray forming process. The microstructures of over-spr... more Cu-TiB2 composite has been manufactured by spray forming process. The microstructures of over-sprayed powder, spray-formed billet, and extruded rod have been characterized by optical microscopy and x-ray diffractometry. The tensile strength of extruded rod was measured by tensile testing. TiB2 particles were formed in a Cu melt of 1500°C by chemical reaction between Ti and B. The TiB2 volume fraction

Materials Science and Engineering: A, 2000

Dispersion strengthened Cu alloys have been manufactured by conventional spray forming and also b... more Dispersion strengthened Cu alloys have been manufactured by conventional spray forming and also by reactive spray forming, followed by hot extrusion of the spray deposited billets. In this work, we have systematically investigated the relationship between the microstructure and mechanical properties of the Cu alloys fabricated through two techniques by means of optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile testing. The size of dispersed particles in the reactive spray formed alloy was much finer than that in the conventionally spray formed alloy. That was because the dominant chemical reaction between Ti and B had occurred in Cu-Ti-B alloy melt in conventional spray forming while it had occurred after deposition of droplets in reactive spray forming. The yield strength of the reactive spray formed alloy was greater than that of the conventional spray formed alloy in spite of a lower volume fraction of reinforced particles. To understand the mechanism responsible for this experimental observation, the yield strength of the two Cu alloys were analyzed using the dislocation pileup model and Orowan mechanism, which were fairly consistent with the experimental results. Increase in yield strength of reactive spray formed alloy compared with that of conventional spray formed alloy was largely attributed to nanoscale TiB dispersoids. This indicates that refining the reinforced particle size to nanoscale is of special importance for the development of high strength Cu alloys since the yield strength predominantly depends on the size and volume fraction of the reinforcement. From this point of view, reactive spray forming can be considered as a new promising process to develop high strength Cu alloys.

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Journal of Organometallic Chemistry

Abstract The reaction of Os 3 (CO) 12 with the tripodal ligand 1,1,1-tris(diphenylphosphinomethyl... more Abstract The reaction of Os 3 (CO) 12 with the tripodal ligand 1,1,1-tris(diphenylphosphinomethyl)ethane, triphos, results in the formation of the 48e trinuclear cluster complex Os 3 [μ-Ph 2 PCH 2 C(Me)(CH 2 PPh)CH 2 PC 6 H 4 ](CO) 7 (η 1 -Ph). This new complex has been characterized by X-ray crystallography as well as by IR and NMR spectroscopy. The activation of the triphos ligand to yield the novel 9e donor ligand Ph 2 PCH 2 C(Me)(CH 2 PPh)CH 2 PC 6 H 4 is unprecedented. The triphos ligand does not cap the triangular Os 3 face; instead, the three phosphorus atoms are coordinated to only two of the metal atoms with the remaining osmium atom coordinated by an ortho -metalated aryl group. The triphos ligand is also transformed in several ways. Two C–P bonds are cleaved during the reaction, yielding an η 1 phenyl ligand in the product and free benzene. The bonding in 1 has been examined by electronic structure calculations.

Journal of Organometallic Chemistry, 2016

Abstract Four new triosmium carbonyl complexes containing multiple dppm ligands were produced by ... more Abstract Four new triosmium carbonyl complexes containing multiple dppm ligands were produced by microwave heating of solutions containing Os3(CO)12 and excess dppm. Three of these complexes, Os3(μ-H)2(CO)6(μ-dppm)[μ3-Ph2PCHP(C6H4)Ph] (2), Os3(CO)6[μ3-Ph2PCH2P(C6H4)Ph]2 (3), and Os3(μ-H)(CO)6[μ3-PhPCH2P(C6H4)Ph][μ3-PhPCH(C6H4)PPh] (4), contain two dppm ligands per Os3 unit, while the fourth, Os3(μ-H)(CO)5(dppm)[μ3-PhPCH2P(C6H4)Ph][μ3-PhPCH(C6H4)PPh] (5), is the first example of an Os3 cluster containing three dppm ligands. Microwave heating was also used to prepare the known complex Os3(μ-dppm)2(CO)8 (1) more efficiently than previously reported. The new complexes 2–5 have been characterized by IR, NMR, mass spectrometry, and X-ray crystallography. In addition, the bonding in these complexes has been examined by electronic structure calculations. All of the new complexes contain at least one dppm ligand that has undergone C H and/or C P bond activation. Complex 2 is a 48e cluster that contains one intact dppm ligand and one face-capping dppm ligand that coordinates all three osmium sites through the phosphine moieties and cyclometalated and ortho-metalated carbon atoms. Complex 3 is a 48e cluster with two ortho-metalated dppm ligands while complexes 4 and 5 are 50e clusters that possess a common metallic framework with one cyclometalated dppm ligand and one ortho-metalated dppm ligand.

Journal of Radioanalytical and Nuclear Chemistry, 2008

In order to reduce the toxicity of both raw wastewater and effluent from a rubber products factor... more In order to reduce the toxicity of both raw wastewater and effluent from a rubber products factory, γ-ray treatment was applied at different dose levels. The γ-ray treatment did not completely removed the toxicity, suggesting that there were major toxicants other than destroyable organic compounds. Toxicity identification evaluation (TIE phase 1) was conducted to characterize major toxicants using Daphnia magna. The suspected toxicants in both raw wastewater and effluent were mostly filterable materials and EDTA chelatable metals and, to some degree, non-polar organic compounds. Anion-exchange removable compounds, most likely organics, were found only in raw wastewater. Metal analyses showed that zinc and copper concentrations were above levels causing toxicity to D. magna. After 20 kGy γ-ray treatment of raw wastewater, filtrations both at pH 3 and at the initial pH (pH 3.6) showed dramatic change (9 to 77% and 29 to 85%, respectively) in toxicity reduction, suggesting the formation of toxic filterable materials which are stable even at acidic conditions. Unlike raw wastewater, there was no significant change in TIE results after γ-ray treatment at 20 kGy for rubber effluent.

Journal of Organometallic Chemistry, 2013

Microwave heating is used to synthesize compounds of the type Os 2 (m-O 2 CR) 2 (CO) 6 , includin... more Microwave heating is used to synthesize compounds of the type Os 2 (m-O 2 CR) 2 (CO) 6 , including the first example with aromatic carboxylate ligands. The one-step preparation of these complexes is straightforward and does not require an air-free reaction environment. The compounds for which R ¼ Me (1) or Et (2) are produced in higher yield than previously reported by the microwave irradiation of Os 3 (CO) 12 for less than 15 min in acetic or propionic acid, respectively. This method may also be used to prepare the new compound Os 2 (m-O 2 CH) 2 (CO) 6 (3) by reaction with formic acid, but a higher yield is obtained when 1,2-dichlorobenzene is used as a co-solvent. Irradiating a mixture of Os 3 (CO) 12 and excess benzoic acid in 1,2-dichlorobenzene gives another new complex Os 2 (m-O 2 CC 6 H 5) 2 (CO) 6 (4). X-ray crystallographic analyses of 3 and 4 reveal molecular structures similar to that of 1 with approximate C 2v symmetry. When the molar ratio of benzoic acid to Os 3 (CO) 12 is 1:1, then the major product is the trinuclear cluster Os 3 (m-H)(m-O 2 CC 6 H 5)(CO) 10 (5) instead of a dinuclear compound. This represents the first instance in which a cluster of this type has been produced directly from Os 3 (CO) 12 instead of through a multi-step procedure.

Journal of Cluster Science, 2013

Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science - METALL MATER TRANS A, 1998

The solidified carbide morphology, the decomposition behavior of the M2C carbide, and the carbide... more The solidified carbide morphology, the decomposition behavior of the M2C carbide, and the carbide distribution after forging of an Fe-1.28C-6.4W-5.0Mo-3.1V-4.1Cr-7.9Co (wt pct) high-speed steel prepared by spray forming have been investigated. The spray-formed microstructure has been characterized as a discontinuous network of plate-shaped M2C carbides and a uniform distribution of fine, spherical MC carbides. The metastable M2C carbides formed during solidification have been fully decomposed into MC and M6C carbides after sufficient annealing at high temperatures. Initially, the M6C carbides nucleate at M2C/austenite interfaces and proceed to grow. In the second stage, the MC carbides form either inside the M6C carbides or at the interfaces between M6C carbides. With this increasing degree of decomposition of the M2C carbide, the carbides become more uniformly distributed through hot forging, which produces a significant increase in ultimate bend strength. The decomposition treatme...

Journal of …, 2011

Microwave-assisted syntheses of the osmium cluster synthons Os6 (CO) 18, Os3 (CO) 10 (NCMe) 2, an... more Microwave-assisted syntheses of the osmium cluster synthons Os6 (CO) 18, Os3 (CO) 10 (NCMe) 2, and Os3 (μ-H)(μ-OH)(CO) 10 are reported. Microwave irradiation of Os3 (CO) 12 in a small amount of 1, 2-dichlorobenzene is shown to be a superior method of preparing ...

Synlett, 2009

SBA-15-supported ionic liquid-Pd(OAc) 2 3 was prepared by the immobilization of ionic liquid 1 on... more SBA-15-supported ionic liquid-Pd(OAc) 2 3 was prepared by the immobilization of ionic liquid 1 onto SBA-15, followed by the treatment with Pd(OAc) 2 and ionic liquid [BMI][PF 6 ]. Heck reaction of aryl halides 4 with acrylates 5 was carried out with 1 mol% Pd of 3 in the presence of ...

Journal of Organometallic Chemistry, 2009

The results of simple microwave-assisted ligand substitution reactions of Os 3 (CO) 12 are report... more The results of simple microwave-assisted ligand substitution reactions of Os 3 (CO) 12 are reported. In a remarkably short period of time, the labile complex Os 3 (CO) 11 (NCMe) is prepared in high yield without the need for a decarbonylation reagent such as trimethylamine oxide. Microwave irradiation of Os 3 (CO) 12 in a relatively small amount of acetonitrile is shown to be a useful first step in two-step, one-pot syntheses of the cluster complexes Os 3 (CO) 11 (py) and Os 3 (CO) 11 (PPh 3).

$Research paper thumbnail of The influence of reinforced particle fracture on strengthening of spray formed Cu-TiB {sub 2} composite$