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Item The C-Hf-Ti System (Carbon-Hafnium-Titanium)(JOURNAL OF PHASE EQUILIBRIA, 2000) Bandyopadhyay, DebashisThe assessed phase diagram of the Ti-C system shown in[1990Oka] conducted a detailed assessment of the C-Hf Fig. 1 is taken from [1998Oka].[1995Alb],[1996Jon], and system, where only one intermediate phase exists. The [1996Sei] reported other assessments of this system, which assessed phase diagram shown in Fig. 3 is taken from consists of two terminal solids α-Ti and β-Ti and a refractory[1990Oka]. Three terminal solids, C (graphite), α-Hf, and monocarbide TiC. The other phases present are liquid and β-Hf, are present in this system.[Massalski1] has reported graphite (C). Two eutectic and one peritectoid reaction appear the temperature of β-Hf⇔ α-Hf allotropic transformation as in this system at 1646, 2776, and 920 C, respectively. There 1743 C. There are several conflicting reports in the literature seems to be a tendency of carbon ordering at compositions([1954Cot],[1961Por],[1962Kat], and [1965Rud]) regarding below stoichiometry; as a result, the Ti2C phase does not the eutectic reaction temperature between C and Hf and its appear in the binary phase diagram. The crystal structure corresponding composition. The crystal structure data of the data shown Table 1 are taken from [Massalski2]. C-Hf system shown in Table 3 are taken from [1990Oka].Item The C-Ti-Zr system (carbon-titanium-zirconium) (vol 22, pg 64, 1998)(JOURNAL OF PHASE EQUILIBRIA, 2001-04) Bandyopadhyay, DebashisItem The Ti-V-C system (titanium-vanadium-carbon)(Springer, 2000-03) Bandyopadhyay, DebashisThe assessed phase diagram of Ti-C system shown in Fig. 1 is taken from [1998Oka]. Other recent work was done on this system by [1995Alb], [1996Sei1], and [1996Jon]. The system consists of two terminal solids aTi and b Ti and a refractory monocarbide TiC. Since there is a tendency of carbon ordering at the compositions below stoichiometry, the phase Ti2C does not appear in the phase diagram. Other phases present are liquid and graphite (C). Two eutectic and one peritectoid reaction appear in this system at 1646, 2776, and 920 °C, respectively.Item The Ti-Cr-C (titanium-chromium-carbon) system(Springer, 1999-05) Bandyopadhyay, DebashisThe assessed phase diagram of Ti-C system in Fig. 1 is taken from [98Oka]. Other recent assessments of this were done by [95Alb],[96Jon], and [96Sei]. The system consists of two terminal solids αTi and βTi and a refractory monocarbide TiC. Other phases present are liquid (L) and graphite (C). Two eutectic and one peritectoid reactions appear in this system at 1646, 2776, and 920 C, respectively. Crystal structure data shownItem The C-Ti-Zr system (carbon-titanium-zirconium)(Springer, 2001-01) Bandyopadhyay, DebashisThe assessed phase diagram of the Ti-C system in Fig. 1 is taken from [1998Oka],[1995ALB],[1996Jon], and [1996Sei] have reported other assessments of this system; all show two terminal solids alpha-Ti and beta-Ti and a refractory monocarbide TiC with other phases being liquid and graphite (C). Two eutectic reactions and one peritectoid reaction take place in this system at 1646 deg C, 2776 deg C, and 920 deg C, respectively. There seems to be a tendency of carbon ordering at compositions below stoichiometry. As a result, the Ti^ sub 2^ C phase does not appear in the binary phase diagram. Crystal structure data of the Ti-C systemItem The C-Nb-Ti system (Carbon - Niobium - Titanium)(Springer, 2000-01) Bandyopadhyay, DebashisThe assessed phase diagram of the Ti-C system in Fig. 1 is taken from [1998Oka]. Other recent assessments on this were done by [1996Jon] and [1996Sei]. The system consists of two terminal solids aTi and bTi and a refractory monocarbide TiC. Other phases present are liquid and graphite C. Two eutectic and one peritectoid reaction appear in this system at 1646, 2776, and 920 °C, respectively.Item The Ti - N - C system (titanium - nitrogen - carbon)(Springer, 2000-03) Bandyopadhyay, DebashisThe assessed phase diagram of Ti-C system in Fig. 1 is taken from [1998Oka]. Other recent assessments of this system were done by [1995Alb], [1996Jon1], and [1996Sei]. The system consists of two terminal solids aTi and bTi and bTi and a refractory monocarbide TiC. The phase Ti2C does not appear in the equilibriam phase diagram, as there appears to be a tendency of carbon ordering at the stoichiometry. Other phases present are liquid and graphite (C). Two eutectic and one peritectoid reaction appear in this system at 1646, 2776, and 920 °C, respectivelyItem Ionic Liquid as Soluble Support for Synthesis of 1,2,3-Thiadiazoles and 1,2,3-Selenadiazoles(ACS, 2012) Kumar, AnilA convenient synthesis of 1,2,3-thiadiazoles and 1,2,3-selenadiazoles was achieved using an ionic liquid as a novel soluble support. Ionic liquid-supported sulfonyl hydrazine was synthesized and reacted with a number of ketones to afford the corresponding ionic liquid-supported hydrazones that were converted to 1,2,3-thiadiazoles in the presence of thionyl chloride. The reaction of ionic liquid-supported hydrazones with selenium dioxide in acetonitrile afforded 1,2,3-selenadiazoles. The advantages of this methodology were the ease of workup, simple reaction conditions, and high purity.Item Local Softness and Hardness Based Reactivity Descriptors for Predicting Intra- and Intermolecular Reactivity Sequences: Carbonyl Compounds(ACS, 1998) Roy, Ram KinkarThe DFT-based reactivity descriptors “local softness” and “local hardness” are used as reactivity indices to predict the reactivity sequences (both intramolecular and intermolecular) of carbonyl compounds toward nucleophilic attack on them. The finite difference approximation is used to calculate local softness, whereas local hardness is approximated by −Vel/2N, where Vel is the electronic part of the molecular electrostatic potential. Both aldehydes and ketones, aliphatic and aromatic, have been selected as systems. Critical cases, e.g., C6H5CHCHCHO, CH3CHCHCHO, and CH2CHCHO, where a CC double bond is in conjugation with the CO group, are also considered. Two new reactivity descriptors are proposed, “relative electrophilicity” (sk+/sk-) and “relative nucleophilicity” (sk-/sk+), which will help to locate the preferable reactive sites. Our results show that local hardness can be used as a guiding parameter when constructing intermolecular reactivity sequences.Item A Simple Model to Predict Preferable Aldol Products from Unsymmetrical Ketones Using Local Hard−Soft Acid−Base Concept(ACS, 2001) Roy, Ram KinkarUnsymmetrical ketones produce two types of enolate intermediates upon deprotonation, which are known as “less substituted” and “more substituted” ones. The major final aldol product will depend on which one of these two enolate intermediates is more reactive toward the incoming reactant (i.e., aldehyde in the case of aldol condensation reaction) in the next stage of the reaction. As here the active sites belong to two different chemical systems, “local hardness” values are reported to be more reliable (Langenaeker et al. J. Phys. Chem. 1995, 99, 6424, and Roy et al. J. Phys. Chem. 1998, 102, 3746) to predict the intermolecular reactivity order of these two intermediates. But in this article we have proposed a very simple model which simultaneously represents both kinds of enolate intermediates. So the present study can be considered as a first one in which an intermolecular problem has been recasted as an intramolecular one, and thus “local softness” and related reactivity descriptors have been used, instead of the “local hardness”, to predict the intermolecular reactivity orders. The generated results show that the model works at satisfactory level.