Electronic and Thermoelectric Properties of Few-Layer Transition Metal Dichalcogenides

The electronic and thermoelectric properties of one to four monolayers of MoS$_{2}$, MoSe$_{2}$, WS$_{2}$, and WSe$_{2}$ are calculated. For few layer thicknesses,the near degeneracies of the conduction band $K$ and $\Sigma$ valleys and the valence band $\Gamma$ and $K$ valleys enhance the n-type and p-type thermoelectric performance. The interlayer hybridization and energy level splitting determine how the number of modes within $k_BT$ of a valley minimum changes with layer thickness. In all cases, the maximum ZT coincides with the greatest near-degeneracy within $k_BT$ of the band edge that results in the sharpest turn-on of the density of modes. The thickness at which this maximum occurs is, in general, not a monolayer. The transition from few layers to bulk is discussed. Effective masses, energy gaps, power-factors, and ZT values are tabulated for all materials and layer thicknesses

Current-voltage characteristics in donor-acceptor systems: Implications of a spatially varying electric field

We have studied the transport properties of a molecular device composed of donor and acceptor moieties between two electrodes on either side. The device is considered to be one-dimensional with different on-site energies and the non-equilibrium properties are calculated using Landauer's formalism. The current-voltage characteristics is found to be asymmetric with a sharp Negative Differential Resistance at a critical bias on one side and very small current on the other side. The NDR arises primarily due to the bias driven electronic structure change from one kind of insulating phase to another through a highly delocalized conducting phase. Our model can be considered to be the simplest to explain the experimental current-voltage characteristics observed in many molecular devices.Comment: 5 pages, 4 figures (accepted for publication in Physical Review B

Surgical management of hepatic hydatid cyst in children

The aim of this study was to demonstrate the surgical treatment and outcome of hydatid cyst in liver in children. The age of presentation varied from 8-11 years. All patients had abdominal pain, five had lump in right hypochondrium and three patients had fever. Hydatid cyst serology, indirect hemaglutination test, ultrasonography and CT scan done in all the patients. Histological examination supported the diagnosis of hydatidosis since the cyst wall contains outer laminated and inner germinal layer. All the patients got relief of their preoperative symptoms after surgery. Two patients had positive serology after surgery. Therefore, they were given two additional regimen of albendazole and turned out to be serologically negative. In conclusion, hydatid cyst management in children is not consensual. However, conservative surgery remains the treatment of choice to avoid serious complication in the endemic region of Indian subcontinent

Synthesis, Characterization and Role of Anions (Nitrate, Sulphate, Oxalate and Acetate) \in the Biological Activity of Hydrazine Derived Compounds and Their Metal Chelates

Hydrazine derived compounds and its Co(II), Cu(II) and Ni(II) chelates having the same metal ion but different anions (e.g., nitrate, sulphate, oxalate and acetate) have been synthesised and characterised by their physical, spectral and analytical data. In order to evaluate the participating role of anions in the antibacterial activity, these synthesised ligands and its metal chelates have been screened against bacterial species such as Staphylococcus aureous, pseudomonas aeruginosa, Klebsiella pneumonae and Proteus vulgarus, and the results are reported

Spectral, Magnetic and Biological Studie on Some Bivalent 3d Metal Complexes of Hydrazine Derived Schiff-Base Ligands

Metal(II) complexes of hydrazine derived Schiff-base ligands of the type M(L)2Cl2 where M = Co, Cu, Ni and Zn and L = L1 and L2 have been prepared and characterised by molar conductance, magnetic moment, elemental analysis and electronic, IR, H-NMR and 13C spectral data.The different modes of chelation of the ligands and their comparative biological properties against different bacterial species are reported

Biological Role of Cobalt(II), Copper(II) and Nickel(II) Metal Ions on the Antibacterial Properties of Some Nicotinoyl-Hydrazine Derived Compounds

Several cobalt(II), copper(II) and nickel(II) complexes of nicotinoylhydrazine-derived compounds were prepared and characterised by physical, spectral and analytical data. These compounds and their complexes have proven to be antibacterial. The screening data show the metal complexes to be more potential/bactericidal than the uncomplexed compounds against one or more bacterial species

Clinicopathologic features predictive of distant metastasis in patients diagnosed with invasive breast cancer

Purpose: National Comprehensive Cancer Network and European Society for Medical Oncology guidelines suggest screening for distant metastasis (M1) in symptomatic patients or those with locally advanced breast cancer. These guidelines are based on studies that often used pathologic staging for analysis. Physician variability in screening for M1 has also resulted in overuse of diagnostic tests. We sought to identify clinicopathologic features at diagnosis that could guide testing for metastatic disease.Methods: Patients diagnosed with invasive breast cancer between January 2014 and December 2015 were identified from our institutional database. Demographic and clinical variables were collected, including receptor profiles and clinical TNM staging. Rates of upstaging for each clinical stage and rates of concordance of pathologic and clinical staging were analyzed. Univariate analysis and multivariate regression analysis (P \u3c .05) identified predictors of upstaging to stage IV disease.Results: A total of 370 patients met the inclusion criteria. Seventy patients (18.9%) had metastatic disease at diagnosis. The rate of upstaging for stages I, IIA, IIB, and III were 0%, 5.6%, 18.8%, and 36.6%, respectively. Advancing clinical stage, tumor size, and nodal status resulted in a significantly higher rate (P \u3c .001) of upstaging to M1 disease. Age and hormone receptor status were not associated with upstaging to stage IV disease. Clinical stages I-III were concordant with pathologic staging in 65(42.8%) of 152 patients (kappa\u27s index, 0.197; P \u3c .000).Conclusion: Advancing clinical stage, tumor size, and nodal status at diagnosis were predictive of upstaging to M1 disease in patients with breast cancer. Distant metastatic workup should be considered in patients with clinical stage IIB disease or higher

Cutting Tools in Finishing Operations for CNC Rapid Manufacturing Processes: Experimental Studies

This paper reports an advanced approach in the application of CNC machining for rapid manufacturing processes (CNC-RM). The aim of this study is to improve the quality of machined parts by introducing different cutting tools during finishing operations. As the cutting is performed in different directions, the surfaces presented on part can be classified into several categories. Therefore, suitable cutting tools are assigned to machine particular surfaces and to improve the quality. Experimental studies have been carried out by fabricating several parts based on the suggested approach. The results provide further support for implementing this approach in rapid machining processes

Cutting Tools in Finishing Operations for CNC Rapid Manufacturing Processes: Experimental Studies

This paper reports an advanced approach in the application of CNC machining for rapid manufacturing processes (CNC-RM). The aim of this study is to improve the quality of machined parts by introducing different cutting tools during finishing operations. As the cutting is performed in different directions, the surfaces presented on part can be classified into several categories. Therefore, suitable cutting tools are assigned to machine particular surfaces and to improve the quality. Experimental studies have been carried out by fabricating several parts based on the suggested approach. The results provide further support for implementing this approach in rapid machining processes