Quantifying technological aspects of process sustainability: a thermodynamic approach

Thermodynamic analysis has greatly helped to compare and to improve the energy efficiency of all kinds of technological processes, and recently we have also attempted to analyse some important biochemical processes under intracellular conditions. This work has pointed to some key strategies on sustainable process operation, such as the exceptionally high thermodynamic efficiencies of chemical and solar energy conversion in living cells.From this it was expected that the sustainability strategies of specific biochemical processes and those of the ecosphere as a whole could be of guidance to current technological processes, especially now that there is a growing demand from government and industry to effectively deal with sustainability aspects in process analysis. Our focus on this issue has led to methodologies to quantify technological aspects of sustainability by making use of thermodynamic principles. Three indicators were constructed to express three technological aspects of process sustainability. First, an indicator for the sustainability of resource utilization considers the thermodynamic input and the availability the resources used in the process. Secondly, an efficiency indicator focuses on the conversion and loss of thermodynamic quantities in the process itself. Thirdly, an indicator for environmental compatibility takes into account the thermodynamic input required to prevent possible negative side effects of the process, such as global warming or water pollution. The three indicators are used to reflect on (un)sustainable characteristics of current technological processes compared to biochemical processes. Finally, we address the drawbacks of combining indicator values to express overall sustainability.     

Critical incidents and chronic stressors at work: Their impact on forensic doctors.

Workers in medium- or high-risk professions are often confronted with critical incidents at the workplace. The impact of these acute stressors may be serious and enduring. Many workers also experience chronic job stressors, such as work overload or role conflicts. This study examined the frequently neglected relationship of acute and chronic stressors with self-reported health symptoms, such as posttraumatic responses, fatigue, and burnout. This association was investigated in a sample of forensic doctors in the Netherlands (N = 84). It was found that the more traumatic events the respondents experienced, the more problems they reported in coping with the traumatic events. Chronic job stressors were associated with posttraumatic responses (intrusions and avoidances) and with burnout and fatigue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Digital implementation of bus clamped space vector modulation

Space vector modulation has recently become a popular PWM method of supplying a high performance drive. An adaptation of SVM modulation is presented here. This system is called bus clamped space vector modulation. This method has some practical advantages when compared to normal SVM. These include a reduced average switching frequency, easy digital implementation and asynchronous control and switching frequencies     

Phase I/II study of a short course of weekly cisplatin in patients with advanced solid tumours

Twenty-five patients with advanced solid tumours were entered in a phase I/II study of six, weekly cycles of cisplatin. Nineteen patients were chemonaive and six were previously treated. The starting dose was 50 mg m-2 week-1. This dose could be escalated without major toxicity to 70 mg m-2 week-1. At a dose of 80 mg m-2 myelosuppression grade 3 occurred as well as grade 1 nephro- and neurotoxicity. The maximum tolerated dose was 85 mg m-2 with dose limiting thrombocytopenia. Hypertonic saline was effective in preventing nephrotoxicity. Ondansetron was a very effective antiemetic in the first weeks of treatment but its efficacy waned later on. Responses were observed in head and neck cancer, melanoma and mesothelioma. At the dose level of 80 mg m-2 the optimal dose intensity was reached. This schedule will be tested further in phase II studies.     

Methotrexate and 6-mercaptopurine maintenance therapy for childhood acute lymphoblastic leukemia: dose adjustments by white cell counts or by pharmacokinetic parameters?

In a consecutive study of 14 boys and 17 girls with non-B-cell ALL who were > or = 1 year of age at diagnosis, the degree of myelosuppression during the last year of MTX/6MP maintenance therapy was analyzed in relation to the erythrocyte concentration of MTX polyglutamates and 6-thioguanine nucleotides (E-MTX and E-6TGN, the respective major cytotoxic metabolites of MTX and 6MP). For each patient, E-MTX and E-6TGN levels were measured 2-15 (median, 6) and 2-17 (median, 7) times, respectively. From these measurements, arithmetic means of E-MTX and E-6TGN were calculated (mE-MTX and mE-6TGN, respectively). Since MTX and 6MP probably work synergistically, the product of mE-MTX and mE-6TGN was calculated for each patient (mE-MTX x 6TGN). The degree of myelosuppression was registered as the mean WBC determined following cessation of the therapy minus the mean WBC measured during the therapy (mWBCshift). The mean WBCs measured on therapy (mWBC(on)) and off therapy were highly correlated (r = 0.48, P = 0.009). The median mWBCshift was 2.7 x 10(9)/l (range, 1.4-4.8 x 10(9)/l). In a multivariate regression analysis, the best-fit model to predict the mWBCshift included mE-MTX x 6TGN, age at drug withdrawal, and mWBC in the order given [mWBCshift = 4.3 + 0.00089 x (mE-MTX x 6TGN) - 0.097 x age - 0.41 x mWBC(on); global rs = 0.66, P = 0.0002]. Thus, the patients with higher mE-MTX x 6TGN values, the younger patients, and the patients with the lowest WBC during therapy had the most pronounced degree of myelosuppression as measured by mWBCshift. These results indicate that E-MTX and E-6TGN may give a better reflection of the treatment intensity than do the WBCs alone.     

Genetic algorithms for optimal logical database design

The focus of this paper is database design using automated database design tools or more general CASE tools. We present a genetic algorithm for the optimization of (internal) database structures, using a multi-criterion objective function. This function expresses conflicting objectives, reflecting the well-known time/space trade-off. This paper shows how the solution space of the algorithm can be set up in the form of tree structures (forests), and how these are encoded by a simple integer assignation. Genetic operators (database transformations) defined in terms of this encoding behave as if they manipulate tree structures. Some basic experimental results produced by a research prototype are presented.     

Excess mortality in general hospital patients with delirium: a 5-year follow-up of 519 patients seen in psychiatric consultation

Mortality was determined in 519 patients with delirium who were seen in psychiatric consultation in two general hospitals. Among 419 patients with simple delirium (DSM-III: 293.00) in-hospital mortality was 26%. As compared to average hospital patients the age adjusted in-hospital excess mortality ratio varied from 6.2 for patients with malignancies to 2.1 for patients with motor system disease. After hospital discharge the 5-yr cumulative mortality was 51%. As compared to the general population excess mortality was noted in most, but not in all diagnostic subgroups. The age and sex adjusted excess mortality ratio varied from 14.1 for malignancies to 1.3 for motor system disease. The figures underline a general notion that delirium may be an indicator of disorders of grave prognosis, but mortality appears to depend more on the medical condition than on the presence of delirium.     

Outcome of transplantation for standard-risk leukaemia with grafts depleted of lymphocytes after conditioning with an intensified regimen

One hundred and eighty-one consecutive patients with standard-risk leukaemia were transplanted with HLA-identical sibling grafts depleted of lymphocytes using counter-flow centrifugation. In 116 patients, standard conditioning was intensified by the addition of anthracyclines. Multivariate analysis revealed significantly more acute GVHD > or = grade 2 and a trend towards more chronic GVHD in patients conditioned with the addition of anthracyclines. For all patients the risk for chronic GVHD, but not for acute GVHD increased with a higher number of T cells in the graft. The projected 5-year probability of relapse was significantly lower in the group of patients conditioned with anthracyclines; 26% versus 52% (P = 0.015). In multivariate analysis the addition of anthracyclines to the conditioning regimen was the only significant factor contributing to a lower probability of relapse. The projected 5-year probability of leukaemia-free survival [LFS] in the patients conditioned with and without the addition of anthracyclines was 56% and 36%, respectively (P = 0.004). In multivariate analysis the addition of anthracyclines to the conditioning regimen correlated significantly with a lower number of mixed chimaeras in patients at 6 and 12 months after BMT. Mixed chimaerism at 6 months after transplantation did not significantly correlate with a higher incidence of relapse in further follow-up. In contrast, mixed chimaerism at 12 months after BMT was significantly associated with higher relapse rate. We conclude that the addition of anthracyclines to the conditioning regimen improves outcome of BMT using T-cell-depleted grafts.     

Non-uniform hydrogen attack cavitation and the role of interaction with creep

Hydrogen attack (HA) is the development of grain-boundary porosity by cavities filled with high-pressure methane that originates from the reaction of carbides with hydrogen at high temperatures. The cavities grow by grain-boundary diffusion and by creep of the adjacent grain material till they coalesce with neighbouring cavities to form a microcrack. Earlier work on HA has focussed on unit cells containing a single cavity, using average cavitation properties. Here, non-uniform cavitation properties on the grain-size scale are assumed in a polycrystalline aggregate, and unit cell analyses are performed to investigate the influence of the adjacent grains on the development of the grain-boundary HA. The numerical results are explained in terms of two simplified models which highlight the key parameters governing the grain deformation-grain boundary cavitation interaction process.