A structural reliability model for composite materials

This work is a part of a project aimed at developing a model and procedure to evaluate the structural reliability of a laminate whose laminae properties are statistically known. The inputs consist of the laminae's elastic properties (deterministic in that they are not as closely related to manufacturing technology) and the derived allowable strengths (aleatoric variables), as well as the sequence (number, orientation, position) of the laminae in the laminate. The output, the laminate's structural reliability, allows determination of the laminate's collapse process, with the most probable lamina failure sequence.     

LISP as a rapid prototyping environment: The Chinese tutor

LISP provides a powerful interactive environment that supports rapid prototyping of complex software. This has always been a main feature of the language, and one that has contributed to its widespread use for experimental applications. Recent years have also seen the development of LISP systems that provide performance comparable with, or better than, that of more traditional programming languages. The next logical step is to show that systems developed in LISP with a rapid-prototyping approach can also provide excellent performance. As an example of the suitability of LISP for rapid prototyping of efficient systems, this article presents a case study where a system was built in a Common Lisp environment out of a series of existing tools. Reliance on existing tools, as well as the interactive features typical of LISP, resulted in extremely rapid prototyping. The system, a computer-based tutor for beginner-level Chinese, was developed in less than three man-weeks. Very rapid development time, however, did not in any way sacrifice performance: the system's performance is quite good and comparable to that of ad hoc systems. This is true of both the interactive component of the program, i.e. the interface to the student, and the database component, which stores the system's knowledge about the Chinese language. The factors that contributed most to the short development time were the extensive reliance on existing tools, the use of an efficient knowledge representation language to implement most of the data structures, and the use of an integrated programming environment. All of these factors were in turn made possible, or at least greatly facilitated, by the choice of LISP as the programming language.     

A spice-based approach to steady state circuit analysis

A new SPICE-based approach for steady state circuit analysis is presented which uses SPICE computational capabilities and a master programme to carry out the periodic response. the master programme implements a suitable method for steady state analysis and is linked with SPICE only via I/O SPICE files. This allows the use of all SPICE analyses together with the new one simply by adding a new statement in the input SPICE file. In this paper the bases of this technique, including the chosen steady state method and the whole system structure, are discussed. Simulation results produced by this technique have been compared, by means of two meaningful examples, with those obtained both by SPICE and by a dedicated simulator for steady state analysis working in the frequency domain.     

Fast parallel polynomial division via reduction to triangular toeplitz matrix inversion and to polynomial inversion modulo a power

It is known that division with a remainder of two polynomials of degree at most s can be performed over an arbitrary field F of constants using uniform arithmetic and Boolean circuits of depth O(log s log log s) and polynomial size. A new algorithm is presented that yields those bounds via reduction to triangular Toeplitz matrix inversion and to polynomial inversion modulo a power. (If|F| > (s?1)² or if P-uniform computation is allowed, then the depth can be reduced to O(log s).) This approach is new and makes the result conceptually simpler.     

Development and Validation of a Method for the Determination of Quinolones in Muscle and Eggs by Liquid Chromatography-Tandem Mass Spectrometry

In this study, the development and validation of a multiresidue method for the detection of 11 quinolones (marbofloxacin, norfloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, nalidixic acid, flumequine) in muscle and eggs were reported. The method involved an extraction with a methanol/metaphosphoric acid mixture and a clean up by Oasis hydrophilic-lipophilic balance (HLB) cartridge. The validation was performed according to the Commission Decision 2002/657/EC. Linearity, specificity, decision limit (CCα), detection capability (CCβ), recovery, precision (repeatability and within-laboratory reproducibility), and ruggedness were determined. Depending on the analytes, CCα and CCβ ranged from 113 to 234 μg/kg and from 126 to 282 μg/kg in muscle samples, whereas in eggs, these parameters were between 5.6 and 7.4 μg/kg and between 6.1 and 9.8 μg/kg, respectively. In both the examined matrices, the recovery values were always higher than 90 % and precision, calculated as relative standard deviation, was equal to or lower than 16 % for repeatability and 23 % for within-laboratory reproducibility. The described method can be considered adequate for the simultaneous determination and quantification of quinolones in the tested food matrices.     

Rapid depletion of marbofloxacin residues in rabbit after therapeutic treatment

Although rabbit meat production represents a very small percentage of the world meat market, this percentage has been growing continuously during the last 30 years. Rabbit is considered a minor food species, and therefore no drugs are specifically registered for this animal. This situation encourages rabbit farmers to make off-label use of antibacterial drugs authorized for food-producing animal species other than rabbits. In the present study, the distribution and elimination of the fluoroquinolone antibacterial agent marbofloxacin in rabbit muscle, liver, and kidney was investigated. Marbofloxacin was chosen as a representative of a new generation of antibacterial drugs active against most gram-positive and gram-negative bacteria and mycoplasms; it is well tolerated and has short elimination times in bovine and swine species. Rabbits were treated with marbofloxacin at 2 mg kg of body weight(-1) for 5 days. Residual concentrations in liver, kidney, and muscle tissues were determined posttreatment with high-performance liquid chromatography and fluorescence detection. Marbofloxacin was rapidly distributed and eliminated from rabbit tissues. Concentrations were higher in the liver and kidney than in muscle. However, 48 h after the end of treatment, marbofloxacin concentrations dropped below the maximum residue level fixed for this antibacterial drug in cattle and pigs. Considering the efficacy of marbofloxacin for the treatment of the most common rabbit diseases, its tolerability, and its short elimination time as verified in the present study, use of this antibacterial drug could be extended to therapeutic treatment of rabbits.     

Sputter-induced trap states at oxidized and grafted silicon surfaces: A comparative study

This paper analyzes the role of sputtering geometries on the conduction mechanism of metal-insulator-semiconductor devices where the insulating film is either SiO_x or a grafted organic (sub)monolayer. The current-voltage characteristics were analyzed and correlated to the presence of traps in the band gap. The most influential defect was found to be related to interstitial Si (Si_i). We will show that its deactivation moves the Fermi level towards other defect/impurity levels depending on both the insulating layer and the deposition geometry. Si_i density decrease is observed when samples are less exposed to sputtered particles and radiation flow, although major effects are also correlated to the degradation of the organic monolayer upon sputtering.