The measurement of dynamic thermal response in rooms using pseudo-random binary sequences

A technique for the measurement of room thermal responses in the time domain using pseudo-random binary sequences is described. The technique gives a determination of the impulse response and the theoretical basis of this is briefly reviewed. Most emphasis, however, is placed on details of the apparatus and experimental procedures. Examples are given of experimental results obtained with a simple test enclosure and, using Fourier transformation, these are compared with results obtained with sinusoidal excitation.     

Multiple sequence comparison — a peptide matching approach

We present in this paper a peptide matching approach to the multiple comparison of a set of protein sequences. This approach consists in looking for all the words that are common to q of these sequences, where q is a parameter.

The comparison between words is done by using as reference an object called a model. In the case of proteins, a model is a product of subsets of the alphabet Σ of the amino acids. These subsets belong to a cover of Σ, that is, their union covers all of Σ. A word is said to be an instance of a model if it belongs to the model.

A further flexibility is introduced in the comparison by allowing for up to e errors in the comparison between a word and a model. These errors may concern gaps or substitutions not allowed by the cover. A word is said to be this time an occurrence of a model if the Levenshtein distance between it and an instance of the model is inferior or equal to e. This corresponds to what we call a Set-Levenshtein distance between the occurrences and the model itself. Two words are said to be similar if there is at least one model of which both are occurrences. In the special case where e = 0, the occurrences of a model are simply its instances. If a model M has occurrences in at least q of the sequences of the set, M is said to occur in the set.

The algorithm presented here is an efficient and exact way of looking for all the models, of a fixed length k or of the greatest possible length k_max, that occur in a set of sequences. It is linear in the total length n of the sequences and proportional to (e + 2)(2e+ 1)k^e+1p^e+1 g^k where k n is a small value in all practical situations, p is the number of sets in the cover and g is related to the latter's degree of nontransitivity.

Models are closely related to what is called a consensus in the biocomputing area, and covers are a good way of representing complex relationships between the amino acids.     

Influence of ion energy on damage induced by Au-ion implantation in silicon carbide single crystals

This article reports on the influence of the ion energy on the damage induced by Au-ion implantation in silicon carbide single crystals. 6H-SiC samples were implanted with Au ions at room temperature at two different energies: 4 and 20 MeV. Both Rutherford Backscattering spectrometry in channelling geometry (RBS/C) and Raman spectroscopy were used to probe the ion implantation-induced damage. Results show that the accumulated damage increases with the fluence up to the amorphization state. RBS/C data indicate that 4-MeV implantation induces more damage than 20-MeV implantation at a given fluence. This effect is attributed to nuclear collisions since the amount of damage is identical at 4 or 20 MeV when the fluence is rescaled in dpa. Surprisingly, Raman data detect more damage for 20-MeV implantation than for 4-MeV implantation at low fluence (below 10¹³ cm⁻²) where point defects are likely formed.     

A review about the effects of structural and operational factors on the gigacycle fatigue of steels

It is well‐known that the high cycle fatigue (HCF) strength of steel components is influenced by a lot of factors depending on both material, loading (including environment), specimen or component geometry (design), and manufacturing process. Based on a literature review of a lot of experimental data, a synthesis is proposed in this paper to discuss the effect of the structural and operational factors on the very high cycle fatigue (VHCF) characteristics of steels. HCF and VHCF regimes are distinguished in terms of failure mechanisms and S‐N curve shapes for high and low strength steels. Then, the effect of the microstructural and mechanical features on the VHCF resistance is debated as different parameters (microstructure, inclusion size type and depth, hydrogen, environment, maximum tensile strength, and residual stresses). Next, the influence of the loading conditions is addressed by taking into account both the frequency effect, the highly stressed volume, the loading type, and loading ratio. Finally, the influence of the testing techniques used in VHCF experiments is discussed.     

Improvement of Modified Wood Properties with Addition of Chestnut Tannins in Lactic Acid-Based Treatments

Wood modification treatments based on lactic acid oligomers (OLA) and monomers (LA) enhance beech dimensional stability (up to 70%) and biological resistance (less than 3% weight loss according to EN113). Chestnut wood tannins natural biological activity might improve the modified wood durability with milder curing conditions. Treatment consisted of the impregnation of monomers or oligomers mixtures followed by curing (140?°C/160?°C for 48h). Tannins addition is almost inconsequential with oligomeric-based treatment but improved the monomeric-based treatment. In this case, modified wood biological resistance and product persistence were increased. OLA impregnated wood cured at 160?°C was always the best performing treatment regarding dimensional stability and durability, but the addition of tannins in LA systems conferred promising properties to wood allowing simplification of the modification process.     

Influence of Covalent Bonds on the Adhesion Energy at Elastomer-Glass Interfaces

The aim of this study was to analyze the effect of interfacial covalent bonds on the adhesive behavior of an elastomer, a crosslinked polydimethylsiloxane, and a glass substrate. These covalent bonds were created by applying to both materials an appropriate surface treatment by means of plasma polymerization. Adhesion measurements were carried out by analyzing the contact area between a rubber hemisphere and a flat rigid glass plate. The contact was forced under a given compressive loading for different times t_c, then the load was removed and the fracture propagation at the interface was recorded as a function of relaxation time t_r. Finally, adhesion energies were also determined by means of a probe test using a tensile testing machine.     

Influence of methionine supply on the response of lactational performance of dairy cows to supplementary folic acid and vitamin B12

The present experiment was undertaken to determine if the effects of supplementary folic acid on lactational performance were caused by improved methylneogenesis and if the supply in vitamin B₁₂ could affect this metabolic pathway. In this eventuality, supplementary Met, a major source of preformed methyl groups, should reduce the requirements for these vitamins. Sixty multiparous Holstein cows were assigned to 10 blocks of 6 cows each according to their previous milk production. Within each block, 3 cows were fed a diet estimated to supply Met as 1.83% metabolizable protein and 3 cows were fed the same diet supplemented with 18 g of rumen-protected methionine (RPM) to supply Met as 2.23% of metabolizable protein. Within each level of Met, cows received no vitamin supplement or weekly intramuscular injections of 160 mg of folic acid alone or combined with 10 mg of vitamin B₁₂ from 3 wk before to 16 wk after calving. There was no treatment effect on dry matter intake during pre- and postcalving periods: 13.4 ± 0.4 and 21.8 ± 0.4 kg/d, respectively. Milk production was not affected by RPM supplementation. Folic acid and vitamin B₁₂ given together tended to increase milk production during the 16 wk of lactation. This effect was more pronounced during the first 4 wk of lactation: 37.5, 37.7, and 40.3 ± 0.9 kg/d for cows receiving no vitamin supplement, folic acid alone, or folic acid combined with vitamin B₁₂, respectively. Milk fat yield was not affected by treatments. Lactose, crude protein, and total solid yields were greater, in early lactation, in cows injected with folic acid and vitamin B₁₂ together but this effect diminished as lactation progressed. Intramuscular injections of folic acid alone or combined with vitamin B₁₂ tended to decrease plasma concentrations of homocysteine from 5.51 μM with no vitamin supplement to 4.54 and 4.77 ± 0.37 μM, respectively. Results of the present experiment suggest that the effects of the combined supplement of folic acid and vitamin B₁₂ on lactational performance of dairy cows were not due to an improvement in methyl groups supply, because RPM supplement, a source of preformed methyl groups, did not alter the cow responsiveness to vitamin supplements.