Effect of dopant atoms on the roughness of III-V semiconductor cleavage surfaces

We demonstrate that the presence of dopant atoms influences the roughness, morphology, and optical mirror properties of III-V semiconductor (110) cleavage surfaces. High concentrations of Te dopant atoms in GaAs lead to macroscopically curvatured (110) cleavage surfaces with high step concentrations. This "glass-like" fracture behavior is explained by the "lattice superdilation phenomenon" induced by high concentrations of Te dopant atoms in GaAs. (C) 2000 American Institute of Physics. [S0003-6951(00)02303-2]

Atmosphere study on the thermal decomposition behavior of delubrication aiding additives

In the present study, the effect of delubrication aiding additives on the thermal decomposition behavior was investigated. Such additives have been introduced in order to reduce stain formation caused by soot particles. Therefore, the atmosphere during the heat treatment of FeCuC components with Kenolube lubricant and a clean burn additive has been monitored by in-situ FTIR atmosphere analysis directly in the furnace. It was found, that delubrication aids reduce the decomposition into stable species like aromatic compounds. Furthermore, the formation of CO, CO2 and CH4 was increased considerably. In comparison to compacts without delubrication aid, the maximum peak temperatures of the gas evolution does not change considerably. However, with such an additive further peaks are visible. In particular, the bands caused by CO2 and alkene show additional peaks at lower temperatures. As a conclusion it is shown, that delubrication aids lead to improved lubricant decomposition as well as intensified soot burn-off

Functionalized metallic hollow sphere structures

Metal hollow spheres (MHS) and metal hollow sphere structures are special types of cellular metals with an enormous application potential in structural and functional applications. A lot of effort has been made during the last two decades in order to develop the manufacturing process and to investigate the properties of this type of structure. Additional functionalizing of MHS is possible by filling the spheres with ceramic powders or phase change materials. Furthermore, by coating the spheres with different ceramic layers new properties and functions are added. Thus, the structures show excellent mechanical damping properties as well as high heat capacity for thermal storage and fast heat loading and unloading. Grinding or ceramic coating bring more functions to the surface of the spheres. The manufacture and properties of different types of functionalized MHS and their possible applications are highlighted here

Thyroid associated ophthalmopathy: evidence for CD4(+) γδ T cells; de novo differentiation of RFD7(+) macrophages, but not of RFD1(+) dendritic cells; and loss of γδ and αβ T cell receptor expression

Aim: To characterise periorbital immune cells (stages, kinetics) in active and inactive thyroid associated ophthalmopathy (A-TAO; I-TAO). Methods: In orbital tissue cryosections of patients with A-TAO (n = 15), I-TAO (n = 11), and healthy controls (n = 14), adipose and fibrovascular areas were evaluated for MHC II(+) cells, CD45(+) total leukocytes, myeloid cells (CD33(+) monocytes; CD14(+) macrophages; mature RFD7(+) macrophages; RFD1(+) dendritic cells (DCs)), and lymphoid cells (CD4(+) T cells; αβ and γδ T cells; CD20(+) B cells). Results are expressed as medians and 5% confidence intervals. Results: In fibrovascular septae, a surge of CD33(+) immigrants clearly correlating with disease activity generated significantly increased (p<0.05) percentages of CD14(+) and RFD7(+) macrophages. Intriguingly, CD4(+) cells were mostly γδ T cells, while αβ T helper cells were much less frequent. Successful treatment rendering TAO inactive apparently downregulates monocyte influx, macrophage differentiation, and T cell receptor expression. Similar trends were recorded for adipose tissue. Interestingly, RFD1(+) DCs were completely absent from all conditions examined. Conclusion: A-TAO coincides with periorbital monocyte infiltration and de novo differentiation of macrophages, but not DCs. The authors discuss a novel potential role for inflammatory CD4(+) γδ T cells in TAO. Successful treatment apparently downregulates orbital monocyte recruitment and effects functional T cell knockout