Finite element analysis of fluid-structure interaction effect on liquid retaining structures due to sloshing

Fluid-structure interaction problems, which may be categorized into different types, have attracted the attention of engineers because of their numerous practical applications. Sloshing of liquid in a liquid filled container subjected to external excitations and coupled interaction between the liquid and container wall due to sloshing is one such problem. The focus of the present paper is on the development of a numerical scheme using finite element technique to calculate the sloshing displacement of liquid and pressure developed due to such sloshing. The scheme is extended to study the coupled effect of sloshing and container wall movement due to change in the liquid pressure.     

Signal recency effects can be distinguished from signal repetition effects in serial CRT tasks.

Reaction time (RT) is reduced in serial choice tasks when a particular signal, as distinct from the response made to it, is repeated on successive trials, N–1 and N. This experiment with 30 undergraduates showed a separate signal recency effect. RT is also reduced when a signal presented on trial N–2 recurs on trial N. In 3 many-to-one signal-to-response mapping tasks (2 responses 4 signals, 2 responses 8 signals, and 2 responses 16 signals), the effects of recent occurrence of signals were shown to be distinct from the effects of recent occurrence of responses made to them. The magnitude of signal recency effects varies directly with set size, but decreases, and may eventually disappear, with practice. The effect decreases with practice faster when signal sets are small than when they are large. A simple model accounts for these results and for earlier data from many-to-one mapping tasks that show that variations in signal entropy cease to affect choice reaction time if practice is sufficiently prolonged. Predictions from this model for changes in component RT distributions with signal set size, signal repetition, signal recency, and practice suggest further experiments. (French summary) (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fast Classification Networks For Signal Processing

We present a generalization of the corner classification approach to training feedforward neural networks that allows rapid learning of nonbinary data. These generalized networks, called fast classification (FC) networks, are compared against backpropagation and radial basis function networks and are shown to have excellent performance for prediction of time series and pattern recognition. FC networks do not require iterative training and they can be used in many signal processing applications where fast, nonlinear filtering provides an advantage.     

Where shall we shop today? A theory of multiple-stop,multiple-purpose shopping trips

ABSTRACT We integrate into a neo-classical multi-period consumer choice model two new elements: (1) storage and holding activities within a household and (2) an "economic landscape" containing many stores at different distances from the house, that sell possibly different product lines at different prices. The theory leads to multipurpose shopping trips in the one-household one-store case. In the one-household many-store model, we prove the existence of optima by an enumeration argument. We describe an iterative maximization process that generates a cost-minimizing "structure" of shopping trips. This "trip structure" defines a pattern of trips of different lengths to purchase different goods at relevant stores, so as to minimize the purchase and contextual (holding plus transport) cost of any level of consumption, with trip frequency and time-spacing determined over the planning horizon.     

Comparison of Ba(OH)2, BaO, and Ba as Starting Materials for the Synthesis of Barium Titanate by the Alkoxide Method

A discussion of the relative merits and problems of using Ba(OH)₂, BaO, and Ba as starting materials for the synthesis of barium titanate by the alkoxide method is presented. The Ba(OH)₂ process is promising because it does not involve the synthesis of barium alkoxide, whereas the BaO (93% pure) process suffers from complex chemical reactions; the impurities in BaO cause unknown effects on the composition and properties of the final ceramic. Use of high-purity Ba metal (99.99%) for the synthesis of barium alkoxide is more desirable since it results in high-purity, ultrafine barium titanate powders.     

Ultrasound guided fine needle aspiration cytology in abdominal tuberculosis

Although barium studies and CT are useful in assessing abdominal pathology in tuberculosis, imaging findings are not always specific and a histopathological or bacteriological confirmation is often required. The aim of the present study was to evaluate the role of ultrasound (US) guided fine needle aspiration cytology (FNAC) in the diagnosis of abdominal tuberculosis in patients with non-palpable lesions detected on US/CT. FNAC was performed on 31 sites in 30 patients. The sites included enlarged lymph nodes (n = 14), focal lesions in liver (n = 2) and spleen (n = 8), and thickened bowel in the ileocaecal region (n = 7). The results were classified cytomorphologically into four groups: (1) definite evidence of tuberculosis; (2) presumptive evidence of tuberculosis; (3) suggestive of tuberculosis; and (4) negative for tuberculosis. 18 of the 31 FNACs (58%) revealed a positive diagnosis of tuberculosis (definite evidence in nine patients and presumptive evidence in nine patients). 13 of the 31 FNACs (42%) showed either necrosis alone (n = 4) or negative results (n = 9). Zeihl-Neelson staining for acid-fast bacilli on direct smear was positive in only nine patients (29%). Splenic and lymph nodal FNAC had a high sensitivity (87.5% and 78.6%, respectively) in the diagnosis of tuberculosis. None of the bowel and liver FNACs was diagnostic. No complications were encountered. US guided FNAC offers a safe and accurate method of achieving a diagnosis in patients with suspected abdominal tuberculosis who present with radiologically demonstrable but non-palpable lesions, especially those involving lymph nodes and spleen.     

Aromatic polyesters (polyarylates) containing arylene sulfone ether linkages

A series of soluble aromatic polyesters (polyarylates) containing arylene sulfone ether linkages and having inherent viscosities of 0.36–1.10 dl/g were prepared by the two-phase low temperature polycondensation of 4,4′-[sulfonyl-bis(p-phenyleneoxy)]dibenzoyl chloride and 3,3′-[sulfonylbis(p-phenyleneoxy)]-dibenzoyl chloride with various bisphenols in an organic solvent-aqueous alkaline solution system in the presence of a phase transfer catalyst. Bisphenols 4,4′-[sulfonylbis(p-phenyleneoxy)]diphenol and 3,3′-[sulfonylbis(p-phenyleneoxy)]-diphenol were synthesized in quantitative yields by an improved procedure. The aromatic polyesters prepared were characterized by infrared spectroscopy, elemental analysis, solution viscosity, thermogravimetric analysis, differential scanning calorimetry and X-ray diffraction. The polyesters prepared had glass transition temperatures in the range 150–230°C and initial decomposition temperatures of 397–491°C. They gave transparent, tough and flexible films by the solution casting technique.