Computational study of the reaction between chloroacetone and OH radical

In this study, the reaction of the chloroacetone with OH radical was studied theoretically using density functional theory (DFT) and transition state theory. The potential energy surface of the reaction was calculated at the CAM-B3LYP/6-311++G(2d,2p) and M06-2X/6-311++G(2d,2p) levels. We initially considered four possible reaction paths: (1) the hydrogen atom abstraction from chloroacetone by OH radical; (2) the addition of the OH radical to the carbonyl carbon; (3) chlorine atom abstraction; and (4) SN2 displacement. The conventional transition state theory was employed to calculate the rate constants. The hydrogen abstraction from the ?CH2Cl group was found to be dominant. Since, the predicted total rate constant at the CAM-B3LYP/6-311++G(2d,2p) level was in good agreement with the experimental value at 298 K, the level of theory used in this study to describe this reaction is appropriate.ArticleCOMPUTATIONAL AND THEORETICAL CHEMISTRY. 1020:108-112 (2013)journal articl

Material damage in TBCs by a synthetic CMAS and the non-destructive detection:-An exploration via a single crystal YSZ-

More recently a new type of damage has been pronounced in thermal barrier coatings (TBCs) by calcium-magnesium-alumino-silicates (CMAS) from ingestion of siliceous minerals under certain operating conditions, based on synthetic material in Table 1. In order to understand material aspect of CMAS damage, a study on material interaction between a synthetic CMAS and a single crystal yttria-stabilized zirconia (YSZ) was studied in this work. Here, the effect of crystallographic orientation on the interaction was also investigated. The experimental works clearly showed that the material interaction between the CMAS and YSZ was significant, resulting in the change in microstructural morphology(Fig. 1(a)). The extent of interaction depended on the crystallographic factor of the YSZ (Fig. 1(b)). The CMAS damage developed depending on the crystallographic plane of YSZ; it was the lowest onthe {111} plane.This is a noteworthy finding tomitigate the CMAS damagein EB-PVD top coat. The change in physical properties was also found to be pronounced at the CMAS damaged area. Based on these findings the non-destructive detection was also tried for engineering applications. Please click Additional Files below to see the full abstract

Material damage in TBCs by a synthetic CMAS and the non-destructive detection:-An exploration via a single crystal YSZ-

More recently a new type of damage has been pronounced in thermal barrier coatings (TBCs) by calcium-magnesium-alumino-silicates (CMAS) from ingestion of siliceous minerals under certain operating conditions, based on synthetic material in Table 1. In order to understand material aspect of CMAS damage, a study on material interaction between a synthetic CMAS and a single crystal yttria-stabilized zirconia (YSZ) was studied in this work. Here, the effect of crystallographic orientation on the interaction was also investigated. The experimental works clearly showed that the material interaction between the CMAS and YSZ was significant, resulting in the change in microstructural morphology(Fig. 1(a)). The extent of interaction depended on the crystallographic factor of the YSZ (Fig. 1(b)). The CMAS damage developed depending on the crystallographic plane of YSZ; it was the lowest onthe {111} plane.This is a noteworthy finding tomitigate the CMAS damagein EB-PVD top coat. The change in physical properties was also found to be pronounced at the CMAS damaged area. Based on these findings the non-destructive detection was also tried for engineering applications. Please click Additional Files below to see the full abstract

Echocardiographic Manifestations in Patients with Cardiac Sarcoidosis

BackgroundCardiac sarcoidosis is a life-threatening disease with protean clinical manifestations, including congestive heart failure (CHF), conduction disturbance, ventricular arrhythmia and sudden death. Nonetheless, it is difficult to diagnose cardiac sarcoidosis in the clinical setting. Some echocardiographic findings of cardiac sarcoidosis associated with other diagnostic tools (201thallium scintigraphy, 67gallium citrate scan, serum markers and others) may be helpful upon early suspicion and diagnosis of cardiac sarcoidosis.Materials and MethodsFifty-two patients (36 female) with cardiac sarcoidosis, with a mean age of 48 ± 14 years (range, 21–70 yr), underwent a series of echocardiographic follow-up (mean, 88 ± 48 mo) examinations, and important echocardiographic parameters and findings were recorded.ResultsThere were left ventricular (LV) regional wall motion abnormalities (RWMAs) noted in 40 (localized in 16, multiple in 24), dilatation of the LV with impaired LV contractility in 28, thinning of the basal interventricular septum (IVS) in 27, thinning of LV free wall in 18, apical aneurysm in 12, apical thrombus in two, mimicking hypertrophic cardiomyopathy (HCM) in two, pericardial effusion (PE) in two (with cardiac tamponade in one), and LV wall thinning and aneurysm formation after steroid therapy for cardiac sarcoidosis in two of 43 patients.ConclusionThinning of the basal IVS or LV free wall is a specific echocardiographic finding of cardiac sarcoidosis. Other echocardiographic findings of cardiac sarcoidosis may mimic coronary artery disease (LV RWMA or apical aneurysm), CHF, or HCM. PE and thinning of the LV wall after steroid therapy were also noted in rare situations