Surgical management of necrotizing scleritis

We successfully used autogenous periosteum to reinforce the weakened sclera of two patients with necrotizing scleritis. One of these patients previously had an onlay scleral graft made from homologous banked sclera, which had subsequently melted. Autogenous periosteum is suggested as an alternative to banked sclera for scleral reinforcement.     

Continuous simulation of a car-following equation

Traffic behavior along an urban roadway is explored using a continuous simulation model of a leader-follower pair of vehicles. The model employs a non-linear car-following differential equation that characterizes the motion of the pair. The implementation of the conceptual model is programmed in the continuous simulation language, MIMIC. In analyzing the results, an emphasis is placed on the formulation of a simple exponential expression that describes the pair motion. This exponential formula may replace the traditional differential equation in sketching pair behavior and platoon dispersion in traffic systems and simulation models.     

The surface tension of Fe-Y and Fe-C-Y alloys at 1550°C

The surface tensions of liquid Fe-Y and Fe-C-Y alloys containing 0 to 2 wt pct C and up to 0.8 wt pct Y were measured at 1550°C with a sessile drop technique. Yttrium was found to be surface active in both Fe-Y and Fe-C-Y alloys in the composition ranges studied. The addition of carbon reduces the surface tension of Fe-Y alloys. This work is based on a portion of a thesis submitted by R. MRDJENOVICH to Wayne State University in partial fulfillment of the requirements for the degree Master of Science in Metallurgical Engineering.     

The Scintillation Mechanism in Thallium Doped Alkali Halides

In the scintillation mechanism for alkali iodides doped with thallous iodide: 1. Most of the luminescence, and possibly all of it, is from recombination and therefore energy transfer is predominantly from charge transport to thallium. 2. There are two modes of recombination at thallium which differ in the sequence of charge trapping at Tl+. The electron may be trapped before a mobile hole recombines with it, or the hole may be trapped before recombination with a free electron. 3. Thermal hole diffusion is an important process at room temperature and determines which mode a recombination event follows. 4. Both modes of recombination are active. 5. There is non-thermal hole trapping which is a significant part of the scintillator mechanism.     

Fatigue-crack propagation characteristics of aluminum alloys in thick sections

Fatigue-crack propagation data have been obtained for a variety of aluminum alloys, tempers, and products in relatively thick sections of interest for large aircraft shapes. For the higher stress-intensity ranges, the alloys rate in about the same order with regard to resistance to fatigue crack propagation as with regard to plane-strain fractare toughness. However, for low stress intensity ranges (i.e. short cracks or low load ranges) the rate of fatigue-crack propagation was lowest for two alloys, 2020-T651 and 2014-T652. which have low plane-strain fracture toughness. The relative order for different specimen orientations was generally consistent with that based upon plane-strain fracture toughness. High humidity results in higher rates of fatigue-crack propagation, with the effect indicated to be largest for those alloys which are susceptible to stress corrosion cracking.     

Synthesis of conjugated bile acids by means of a peptide coupling reagent

The conditions for the preparation of conjugated bile acids by means of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline are described. Conjugation is obtained in one step via the intermediary formation of mixed carbonic-carboxylic acid anhydrides.     

Acute effusive-constrictive pericarditis in influenza A

Constrictive pericarditis may complicate the course of several viral infections, mainly Coxsackie virus group B, as well as in rheumatoid disease, radiation and neoplasm. Perimyocardial involvement during influenzal infections is usually mild and does not progress to constriction or tamponade. A single case of cardiac tamponade caused by influenza A was reported in 1986. We report a case of acute effusive-constrictive pericarditis due to influenza A infection. Corticosteroids resulted in some benefit, but did not relieve constriction, which required extensive pericardiectomy.