On the rate of evaporation of water into a stream of dry air, humidified air and superheated steam, and the inversion temperature

The concept of inversion temperature was developed in order to assess the effectiveness of superheated steam as a drying agent when compared with dry or humid air above a given temperature. The inversion temperature can be defined in different ways, for different physical situations, thus leading to strong discrepancies between its reported numerical values. A clear understanding of such definitions and its consequences over the inversion temperature values is of major importance, as well as the way to estimate the inversion temperature of interest for a given practical evaporation process. Analytical expressions are proposed for some possible definitions of the inversion temperature. Special emphasis is devoted to the physical reasoning on the existence of the inversion temperature and how its value is affected by other variables such as humidity level, mass flow rate and geometry of the evaporative system.     

Squamous cell carcinoma in individuals under 40 years of age

We reviewed all the cases of Squamous Cell Carcinoma in people under 40 years of age, diagnosed histologically at the Dermatopathology Laboratory of the Santa Maria Hospital, from January 1985 to December 1993. The 19 cases detected were analysed for age, sex, occupation, anatomical site of the tumor, evolution, smoke and alcoholic habits, skin phototypes, immunosuppression, previous viral infections, previous radiotherapy or PUVA therapy and associated diseases. A prevalence of an occupation involving more exposure to the sun was found. Males were more affected than females (2.2/1). In 37% of the patients we detected heavy alcoholic habits. The most frequent anatomical site was the lower lip (42%). Patients with skin phototype I were more affected (53%).     

Analysis of the frequency noise of tunable multisection DBR lasers

A theoretical analysis is performed of the frequency noise in tunable two- and three-section distributed Bragg reflector (DBR) laser diodes (LDs), taking into account the nonlinear gain compression effect. For a two-section DBR LD the frequency noise is shown to depend significantly on the tuning current, particularly at low frequencies (below the gigahertz range) and for low and moderate values of the grating coupling coefficient. For high values of this coefficient the tuning dependence is generally negligible when the tuning is performed only through the DBR section, but it becomes significant when using the phase control current in a three-section device. It is shown that the enhancement factor for the spontaneous emission rate due to the longitudinal field dependence increases significantly with tuning for low values of the grating coupling coefficient     

Empirical Optimization for a Sparse Linear Solver: A Case Study

This paper describes initial experiences with semi-automated performance tuning of a sparse linear solver in LS-DYNA, a large, widely used engineering application. Through a collection of tools supporting empirical optimization, we alleviate the burden of performance tuning for mapping today’s sophisticated engineering software to increasingly complex hardware platforms. We describe a tool that automatically isolates code segments to create benchmark subsets for the purposes of performance tuning. We present a collection of automatically generated empirical results that demonstrate the sensitivity of the application’s performance to optimization parameters. Through this case study, we demonstrate the importance of developing automatic performance tuning support for performance-sensitive applications.     

Dynamic process modelling of iron ore sintering

A mathematical model was developed for the iron ore sintering process considering all the major thermochemical phenomena in the system, assuming both the static and moving bed configurations. The model predicted a large number of parameters pertinent to the sintering process including the temperatures of the gas and solid, concentration of various species, amount of solid melted etc. The results were tested against the data existing in literature, and a limited number of pot tests conducted in a pilot plant. Despite high complexity of the problem, the agreement between the experimental and simulated data was reasonably good.     

Reverse dorsal metacarpal osteocutaneous flap

There are a number of possibilities for local and vascularized bone transfer when a small amount of cortico-cancellous bone is required in the hand and fingers. The authors describe the dissection technique and a clinical application of a reverse dorsal metacarpal osteocutaneous flap to reconstruct the proximal phalanx of a fifth finger. They emphasise the bone vascularisation, studied 48 hours postoperatively with a bone scan and confirmed with bone healing 4 weeks later. The advantages are: it is a compound flap, easy to dissect under tourniquet in one operation, it can be done in an emergency care situation and it does not require ligation of an important vascular axis. The essential precaution is to visualise the patency of the fourth dorsal metacarpal artery before flap dissection, acknowledging that in only 63% of cases is there a vascular pattern that allows flap dissection with a long arc of rotation.     

MRI study of bread baking: experimental device and MRI signal analysis

An oven dedicated to a magnetic resonance imager (MRI) was designed and constructed for continuous monitoring of the entire baking process. The general aim was to test whether response variables conventionally measured on bread loaves, such as temperature, density, and water loss, were consistent with those reported for similar products baked in classical convection ovens. MRI images acquired during baking are presented and discussed, emphasising the need to develop quantitative MRI methods allowing conversion of the MRI signal into one variable of interest, such as local density or local water content.     

HPLC separation,NMR and QTOF/MS/MS structure elucidation of a prominent nitric oxide donor agent based on an isomeric composition of a nitrosyl ruthenium complex

A new and promising nitrosyl ruthenium complex, [Ru(NO)(bdqi-COOH)(terpy)](PF₆)₃, bdqi-COOH is 3,4-diiminebenzoic acid and terpy is 2,2′-terpyridine, has been synthesized as a NO donor agent. The procedure used for [Ru(NO)(bdqi-COOH)(terpy)](PF₆)₃ synthesis has, apparently, yielded the formation of two isomers in which the ligand bdqi-COOH appears to be coordinated in its reduced form (bdcat-COOH), which could have differences in their pharmacological properties. Therefore, it was intended to separate the two possible isomers by high-performance liquid chromatography (HPLC) and to characterize them by high resolution mass spectrometry (QTOF MS) and by magnetic nuclear resonance spectroscopy (NMR). The results obtained by MS showed that the ESI-MS mass spectra of both HPLC column fractions, e.g. peak 1 and peak 2, are essentially equal, showing that both isomers display nearly identical gas-phase behavior with clusters of isotopologue ions centered at m/z 573, m/z 543 and m/z 513. Regarding the NMR analysis, the results showed that the positional isomerism is located in the bdqi-COOH ligand. From the observed results it can be concluded that the synthesis procedure that has been used results in the formation of two [Ru(terpy)(bdqi-COOH)NO](PF₆)₃ isomers.