Modeling process-structure-property relationships for additive manufacturing

This paper presents our latest work on comprehensive modeling of process-structure-property relationships for additive manufacturing (AM) materials, including using data-mining techniques to close the cycle of design-predict-optimize. To illustrate the process-structure relationship, the multi-scale multi-physics process modeling starts from the micro-scale to establish a mechanistic heat source model, to the meso-scale models of individual powder particle evolution, and finally to the macro-scale model to simulate the fabrication process of a complex product. To link structure and properties, a high-efficiency mechanistic model, self-consistent clustering analyses, is developed to capture a variety of material response. The model incorporates factors such as voids, phase composition, inclusions, and grain structures, which are the differentiating features of AM metals. Furthermore, we propose data-mining as an effective solution for novel rapid design and optimization, which is motivated by the numerous influencing factors in the AM process. We believe this paper will provide a roadmap to advance AM fundamental understanding and guide the monitoring and advanced diagnostics of AM processing.     

Intelligent decision aids for abnormal events in nuclear power plants

German nuclear power plants are characterized by a high degree of automation, not only for normal operation but also for abnormal events. Therefore the role of the operating personnel is mainly a supervisory function. Nevertheless, for a spectrum of unexpected events the operating personnel have to react with manual recovery actions. In order to minimize human error in such recovery actions, different kinds of intelligent decision aid support the operators today. In this paper such aids are discussed and one of them is described in more detail.     

Blood flow and venous distensibility in the upper and lower extremities of newborn infants

The electrocapacitance plethysmograph was utilized to measure peripheral blood flow and venous distensibility in 17 newborn infants and 20 adults. Measurements were made in the upper and lower extremities in each subject under identical environmental conditions. Blood flow in the forearm and calf were found to be significantly higher in infants than adults. In infants there were no significant differences in the blood flow between the upper and lower extremities. In contrast, in the adults, the blood flow was significantly higher in the upper than in the lower extremities. Similarly, venous distensibility was observed to be higher in infants than in adults. While no significant differences were observed in the venous distensibility between the upper and lower extremities in infants, the venous distensibility was found to be higher in the forearm than in the leg in adults.     

The roles of protein phosphorylation/dephosphorylation in tumor necrosis factor antitumor effects

The roles of protein phosphorylation and dephosphorylation in the tumor necrosis factor (TNF) cytotoxic and antiproliferative effects on L-929-transformed fibroblasts were explored. Genistein and erbstatin, specific inhibitors of tyrosine kinase, had antiproliferative but not cytotoxic effects on the cells by themselves and synergistically enhanced the cytotoxic and antiproliferative effects of TNF-alpha. Immunoblot analysis with a monoclonal antiphosphotyrosine antibody revealed that TNF, administered for 5-180 min, induced tyrosine dephosphorylation of two pairs of membranal proteins, 34-36 kDa and 50-52 kDa, and potentiated tyrosine phosphorylation of a 115-kDa protein in both the cytosolic and membranal fractions of the cells. A very brief exposure (30 sec) to TNF induced rapid phosphorylation of several proteins, whereas genistein, but not inhibitors of other protein kinases, enhanced this effect of TNF. The results suggest that TNF activity could be potentiated by the inhibition of tyrosine phosphorylation and point to specific proteins that are dephosphorylated on tyrosine in response to TNF.     

Electroejaculation in combination with intracytoplasmic sperm injection in patients with psychogenic anejaculation results in lower fertilization rates

OBJECTIVE: To evaluate the outcome of intracytoplasmic sperm injection (ICSI) with sperm obtained by electroejaculation in men with psychogenic anejaculation. DESIGN: Retrospective clinical study. SETTING: In Vitro Fertilization Unit, Bikur Cholim Hospital, Jerusalem, Israel. PATIENT(S): Seven men with psychogenic anejaculation who underwent 16 sessions of electroejaculation in combination with ICSI. INTERVENTION(S): Electroejaculation, ICSI. MAIN OUTCOME MEASURE(S): Semen analysis, ICSI, fertilization rates. RESULT(S): All patients had poor sperm motility. One hundred forty-seven oocytes were injected, with a fertilization rate of 27% (39/142). One ongoing pregnancy was achieved. CONCLUSION(S): Sperm obtained by electroejaculation have low motility and reduced fertilization potential. Nevertheless, ICSI should be offered to improve the possibility of successful pregnancy.     

Advances in probabilistic safety assessment

This paper reviews the evolution of Probabilistic Safety Assessment in the last twenty years, the basic methodology, lessons learned, as well as several current issues. These include the formal use of expert opinions, model uncertainties, the notion of a living PSA, and source-term uncertainties.