Improvement of impact and fatigue strength in compressor blades from VT8M alloy using combined treatment

The effect of combined treatment (deposition of TiN coating + ultrasonic hardening) of compressor blades made from titanium alloy VT8M on impact and fatigue strength is considered.     

Parameterized High Throughput Function Evaluation for FPGAs

This paper presents parameterized module-generators for pipelined function evaluation using lookup tables, adders, shifters, multipliers, and dividers. We discuss trade-offs involved between (1) full-lookup tables, (2) bipartite (lookup-add) units, (3) lookup-multiply units, (4) shift-and-add based CORDIC units, and (5) rational approximation. Our treatment mainly focuses on explaining method (3), and briefly covers the background of the other methods. For lookup-multiply units, we provide equations for estimating approximation errors and rounding errors which are used to parameterize the hardware units. The resources and performance of the resulting design can be estimated given the input parameters. A selection of the compared methods are implemented as part of the current PAM-Blox module generation environment. An example shows that the lookup-multiply unit produces competitive designs with data widths up to 20 bits when compared with shift-and-add based CORDIC units. Additionally, the lookup-multiply method or rational approximation can produce efficient designs for larger data widths when evaluating functions not supported by CORDIC.     

A parallel method for computing the generalized singular value decomposition

We describe a new parallel algorithm for computing the generalized singular value decomposition of two n × n matrices, one of which is nonsingular. Our procedure requires O(n) time and one triangular array of O(n²) processors.     

FDTD analysis of probe-fed cylindrical dielectric resonator antennaoperating in fundamental broadside mode

An analysis of a cylindrical dielectric resonator antenna operating at the fundamental broadside mode using the finite-difference time-domain (FDTD) method is presented. Good agreement between theoretical and experimental results on the input impedance of the DR antenna is obtained. The effects of the probe length, feed position and the dielectric constant on the input impedance are presented     

Attention deficit hyperactivity disorder and anxiety: is there an association with neurodevelopmental deficits?

OBJECTIVE: The co-occurrence of attention deficit hyperactivity disorder (ADHD) and anxiety is a well-established clinical observation. However, its status as a clinical construct is debated. We review the prevalence of 'ADHD and anxiety', its definitions, and its clinical correlates and we hypothesise that neurodevelopmental deficits may be increased in 'ADHD and anxiety'. METHOD: The authors identified empirical studies in the psychiatric and psychological literature. The search categories included hyperactivity, attention deficit hyperactivity disorder, attention deficit disorder and anxiety. RESULTS: 'ADHD and anxiety' is considerably more common in clinical than epidemiological samples. There are a range of definitions which address the situational variation in both ADHD and anxiety symptoms and the use of categorical and continuous variables to define them. Yet the nature of the anxiety is still unclear. It is associated with a poor response to psychostimulant medication treatment, and alternative pharmacotherapy approaches have been suggested. There is a controversy about whether neurodevelopmental deficits are associated with hyperactivity alone, or anxiety, or both. CONCLUSIONS: 'ADHD and anxiety' is important clinically because it is common and less responsive to psychostimulant medication. Important research issues include its heterogeneity which necessitates the collection of parent, teacher, and child self-reports of symptoms' presence or absence and the hypothesis that neurodevelopmental deficits may be increased in this group of children.     

Interdisciplinary treatment of the malignant lymphoma of the thyroid

720 patients with malignant tumor of the thyroid were treated at our department between 1950 and 1996. Histological examination revealed 15 cases (2%) of malignant lymphoma (14 female, 1 male mean age: 69.8 year). In 8 cases Hashimoto thyroiditis, in 1 case chronic lymphocytic thyroiditis was verified beyond the lymphoma. According to Ann Arbor staging, 9 patients were stage I E, 3 II E, 1 III E, and 2 IV E. Radical surgical treatment was performed in 7, palliative in also 7, and only biopsy in one case. Irradiation was administered in 9, chemotherapy in 8 patients. In 5 out of the 7 palliative operated patients tracheostomy was performed. 10 patients were lost. The therapy of the non-Hodgkin lymphoma of the thyroid is debated in the literature. There are some authors, who question the role of surgery. Our experience, based on the longer survival of the patients, who underwent radical operation, support those, who consider the possible surgical treatment as the initial part of the multimodal therapy.     

3D Modeling of electromigration combined with thermal–mechanical effect for IC device and package

This paper studies the numerical simulation method for electromigration in IC device and solder joint in a package under the combination of high current density, thermal load and mechanical load. The three dimensional electromigration finite element model for IC device/interconnects and solder joint reliability are developed and tested. Numerical experiment is carried out to obtain the electrical, thermal and stress fields with the migration failure under high current density loads. The direct coupled analysis and in-direct coupled analysis that include electrical, thermal and stress fields are investigated and discussed. The viscoplastic ANAND constitutive material model with both SnPb and SnAgCu lead-free solder materials is considered in the paper. An IC device is studied to show the modeling methodology and the comparison with previous test data. A global CSP package with PCB is modeled using relative coarse elements. In order to reduce the computational costs and to improve the calculation accuracy, a refined mesh sub-model is constructed. The sub-model technique is studied in a direct and indirect coupled multiple fields. The comparison of voids generation through numerical example in this paper and previous experimental result is given.