Treatment of malignant melanoma (clinical stages I and II) (author's transl)

The uncorrected cumulative five-year survival rate ("actuarial method") among 195 patients with infiltrative malignant melanoma of the skin was 58% (160 cases) in clinical stage I, 26% (35 cases) in clinical stage II. In addition to clinical staging, microstaging - i.e. the histologically determined depth of invasion of the primary tumour - is of great prognostic significance. In microstages 2 and 3 with the largest vertical tumour diameter below 0.76 mm, five-year survival rate was 100% while in microstage 3 with greater vertical tumour diameter it was 66% in microstage 4 55% and microstage 5 31%. Results of treatment can be reliably interpreted only if they are divided according to microstage. Propylactic dissection of the regional lymph-nodes (dissection in clinical stage I) need not be undertaken in microstages 2 and 3 with vertical tumours diameter below 0.76 mm. Whether prophylactic dissection was done in one or two sessions has apprarently no significant influence on survival rate. A single X-radiation dose to the primary tumour of 4 000 -6000 R immediately before excision of the tumour did not significantly increase the results. The results were particularly bad when the primary tumour was removed after inadequate manipulation.     

Analysis of a gas-phase Br<Subscript>2</Subscript>–H<Subscript>2</Subscript> redox flow battery

The operation of a gas-phase Br₂–H₂ flow battery is analyzed via a mathematical model and compared to experimental data. The model predicts the operating conditions of the cell in both fuel-cell (i.e., discharge) and electrolysis (i.e., charge) mode as a function of current, inlet gas composition, flow rate, and pressure differential across the membrane. The analysis reveals that gas-phase Br₂/HBr reactants significantly enhance mass transfer, which enables higher currents densities to be achieved compared to a liquid-fed system. A key feature of the model is water transport across the membrane, which determines membrane conductivity, reactant concentration and undesired condensation. The model is used to provide insight into cell operation, including operating conditions needed to avoid water condensation.     

Metal‐Free,Radical Addition to Alkenes via Desulfitative Chlorine Atom Transfer

An efficient method for radical additions to unactivated alkenes via desulfitative chlorine‐atom transfer is described. The reaction is based on the use of readily available sulfonyl chlorides as starting materials and cheap radical initiators such as azobisisobutyronitrile (AIBN), di‐tert‐butyldiazene (DTBD), and dilauroyl peroxide (DLP). No transition metal catalyst is required and the reaction takes place under mild conditions at temperatures ≤85 °C.     

Study of Deformation Phenomena in TRIP/TWIP Steels by Acoustic Emission and Scanning Electron Microscopy

Modern metastable steels with TRIP/TWIP effects have a unique set of physical-mechanical properties. They combine both high-strength and high-plasticity characteristics, which is governed by processes activated during deformation, namely, twinning, the formation of stacking faults, and martensitic transformations. To study the behavior of these phenomena in CrMnNi TRIP/TWIP steels and stainless CrNiMo steel, which does not have these effects in the temperature range under study, we used the method of acoustic emission and modern methods of signal processing, including the cluster analysis of spectral-density functions. The results of this study have been compared with a detailed microstructural analysis performed with a scanning electron microscope using electron backscatter diffraction (EBSD).     

Evaluation of porous cathodes for the electrochemical reduction of nitrates and nitrites in alkaline waste streams

This paper describes the mathematical modelling and experimental work performed to evaluate porous cathodes for the electrochemical reduction of nitrates and nitrites in alkaline waste streams. A dynamic model of a batch process was developed that included a divided cell with a porous cathode, a cation-selective separator, a planar anode, and reservoirs for electrolyte recirculation and gas–liquid separation. Constant current experiments were done using a divided cell with nickel foam as the porous cathode. The experiments were performed with a catholyte feed of either 0.6 M NaNO₂ or 1.95 M NaNO₃, both supported by a 1.33 M NaOH solution, a current density of 0.25 A cm^–2 and a solution temperature of 32 C. The experimental results showed that the ammonia production reaction is the dominant cathodic reaction (80% of the current). Estimates of the kinetic parameters were obtained using the experimental data and the model. The model was then used to simulate and study the performance of the porous electrode compared to the planar electrode for a range of operating currents. The results showed that at the optimum current density for a planar electrode of 0.25 A cm^–2, use of a porous cathode results in one-third the energy costs and time required to achieve 95% destruction of nitrate and nitrite compared to a planar cathode. At 0.40 A cm^–2, the energy and time required to achieve 95% destruction was an order-of-magnitude less for the porous electrode.     

On-line monitoring of partial discharges on stator windings oflarge rotating machines in the petrochemical environment

This paper describes a joint collaboration program between a major large electric machine manufacturer and a petrochemical manufacturer to investigate the effectiveness of time- and frequency-domain techniques for the online monitoring of the health of high-voltage machine stator insulation systems. Information is given on the factory and site testing carried out, as well as on the analysis and discussion of the results. It is concluded that both techniques can be used in the petrochemical environment for general assessments, but the time domain technique is required if identification of specific locations of discharge sites is needed     

Integrating natural language understanding with document structure analysis

Document understanding, the interpretation of a document from its image form, is a technology area which benefits greatly from the integration of natural language processing with image processing. We have developed a prototype of an Intelligent Document Understanding System (IDUS) which employs several technologies: image processing, optical character recognition, document structure analysis and text understanding in a cooperative fashion. This paper discusses those areas of research during development of IDUS where we have found the most benefit from the integration of natural language processing and image processing: document structure analysis, optical character recognition (OCR) correction, and text analysis. We also discuss two applications which are supported by IDUS: text retrieval and automatic generation of hypertext links     

Vapour–liquid slip in a parallel-plate electrochemical fluorination reactor

A mathematical model was used to study the effect of slip between the gas and liquid phases on the performance of an electrochemical fluorination reactor. The model incorporates two-phase flow with differential material, energy and pressure balances. The effect of slip on the temperature, pressure, gas fraction and current distribution in the reactor is presented under relatively severe operating conditions. In addition, the effect of slip on the cell voltage, current efficiency and energy usage is shown at different flow rates over a wide current range. It was found that slip of the gas past the liquid is insignificant under normal operating conditions, but it is significant at high cell currents and low flow rates. Under these more severe operating conditions, slip significantly reduces the cell voltage, and hence the energy usage, since less gas resides in the reactor.