Binary common-ion alkali halide mixtures thermodynamic analysis of solid-liquid phase diagrams i. systems with negligible solid miscibility application of the extxd/sivamin method

Solid-liquid phase diagrams of 15 binary common-ion alkali halide mixtures, showing negligible solid miscibility, have been analyzed using the EXTXD/SIVAMIN method. The principles of and the philosophy behind the method, which permits the simultaneous derivation of the excess enthalpy and excess entropy functions from a single TX phase diagram, are discussed. The significance of the results is investigated by recalculating the phase diagrams and by comparing the excess enthalpy functions with experimental heats of mixing.     

UNSTUDIO

UNStudio由Ben van Berkel和Caroline Bos建立,是一家荷兰的建筑工作室,主要涉及的领域包括建筑、城市发展和基建项目。UNStudio的名字与实践中的合作有关。     

Benchmark exercise on risk assessment methods applied to a virtual hydrogen refuelling station

A benchmarking exercise on quantitative risk assessment (QRA) methodologies for hydrogen safety has been conducted within the project HyQRA, under the framework of the European Network of Excellence (NoE), HySafe. The aim of the exercise was twofold: (i) to identify the differences and similarities in approaches in a QRA and their results for a hydrogen installation and (ii) to identify knowledge gaps in the various steps and parameters underlying the risk quantification of hydrogen safety.First, a reference case was defined for the benchmark: a virtual hydrogen refuelling station (HRS) in virtual surroundings comprising housing, school, shops and other vulnerable objects. For the study, a two phase approach was followed.In phase 1, all nine partners were requested to conduct a QRA according to their usual approach and experience. Basically, participants were free to define representative release cases, to apply models and frequency assessments according their own methodology, and to present risk according to their usual format. To enable inter-comparison, a required set of results data was prescribed, like distances to specific thermal radiation levels from fires and distances to specific overpressure levels. Moreover, complete documentation of assumptions, base data and references was to be reported.It was not surprising that a wide range of results was obtained, both in the applied approaches as well as in the quantitative outcomes and conclusions. This made it difficult to identify exactly which assumptions and parameters were responsible for the differences in results.These results provided the basis for a more guided QRA, the second phase. This phase 2 was defined in which the QRA was determined by a more limited number of release cases (scenarios). The partners in the project agreed to assess specific scenarios in order to identify the differences in consequence assessment approaches. The results of this phase provide a better understanding of the influence of modelling assumptions and limitations on the eventual conclusions with regard to risk to on-site people and to the off-site public.     

Field measurement of splice loss applying the backscattering method

A method it proposed to measure mean splice loss applying the back-scattering method from one end of the fibre link only. To eliminate the influence of the difference in back-scattering properties of the spliced fibres, each backscattering coefficient is measured separately beforehand.     

Premature ejaculation and serotonergic antidepressants-induced delayed ejaculation: the involvement of the serotonergic system

OBJECTIVE: To analyze the causes of therapeutic success and failure in the management of patients with high-risk gestational trophoblastic tumors (GTTs). STUDY DESIGN: Analysis of 272 consecutive high-risk patients treated at the trophoblastic disease center at the Charing Cross Hospital between 1979 and 1995. RESULTS: EMA (etoposide, methotrexate, actinomycin D)/CO (cyclophosphamide, vincristine) chemotherapy is our treatment of choice for patients with high-risk GTT. In 272 consecutive patients the cumulative five-year survival was 86.2% (95% confidence interval, 81.9-90.5%). No deaths occurred from GTT more than two years after the start of treatment. In patients whose disease became resistant to EMA/CO or relapsed after receiving EMA/CO, the majority (70%) could be salvaged with further chemotherapy (usually with the EP (etoposide, cisplatin)/EMA chemotherapy with or without surgery. Multivariate analysis identified the following adverse prognostic factors: presence of liver metastases (P < .0001), prolonged interval from antecedent pregnancy (P < .0001), presence of brain metastases (P = .0008) and term delivery of antecedent pregnancy (P = .045). Intensive chemotherapy for treating high-risk GTT carries a small risk of inducing second malignancies, and two patients developed acute myeloid leukemia, 2 cervical malignancy and 1 gastric adenocarcinoma after receiving EMA/CO chemotherapy. CONCLUSION: EMA/CO is an effective and well-tolerated regimen for high-risk GTT. Salvage chemotherapy with EP/EMA is effective in the majority of patients whose disease is resistant to EMA/CO and should be combined with surgery when the dominant site of resistant disease is known. Major adverse prognostic variables have been identified, and patients with combinations of these factors should be considered for innovative therapeutic approaches from the outset.     

Sperm oil replacements from selectively hydrogenated soybean and linseed esters: Special lubricants

Soybean and linseed oils were selectively hydroenated with copper-on-silica gel catalyst. The linolenate content of the oils was reduced to diene and monoene with no appreciable increase in saturates. Hydrogenated soybean oils contained 68–76% monoene, 11–18% diene, 0% conjugated diene and triene, 1–6% conjugatable diene, 0–0.3% conjugatable triene, and 23–40% isolatedtrans double bonds. Hydrogenated linseed oils contained 44–54% monoene, 35–45% diene, 0% conjugated diene and triene, 0–7% conjugatable diene, 0–02% conjugatable triene, and 44–59% isoaltedtrans double bonds. Esters of fatty acids, derived from these selectively hydrogenated oils, were prepared with trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, ethylene glycol, C₁₈ saturated cyclic alcohols, primary C₁₂–C₁₈ saturated (nC₁₂, nC₁₄, nC₁₆, nC₁₈) alcohol, and primary C₁₆–C₁₈ saturated (nC₁₆, nC₁₈) alcohol blends. Measurements of viscosities and of smoke, flash, and fire points indicate that these esters are possible replacements for sperm oil. Certain of them, after sulfurization, also have potential as extreme pressure lubricant additives. Presented at the AOCS meeting in Philadelphia, September 1974.     

Cavernous malformations: from frame-based to frameless stereotactic localization

AIM: To determine the change in use of a day surgery unit over a 21-year period. DESIGN: Retrospective analysis. SETTING: The day surgery unit within a central London dental hospital. MATERIALS: The operating and anaesthetic records of surgical activity in 1973, 1983, 1993 and 1994. RESULTS: A six-fold increase in the total number of dentoalveolar procedures performed was demonstrated during the period studied. However, these procedures represented only 77.6% of surgical activity in 1994 compared with 98.9% in 1973. CONCLUSIONS: Day case surgery appears to be advantageous to patients, clinicians, hospital managers and purchasing authorities. The development of more specialist day case services and facilities within "dental centres' is proposed as a means of ensuring that the specialty is able to adapt to the changing patterns of health care in the future.