A student's t-test was applied in carbon nanospheres synthesis from cis-1,4-polyisoprene considering the green chemical principles. The synthesis was carried out by Chemical Vapor Deposition method with a quartz tube reactor using an AISI 304 steel bar as catalyst. It was possible to obtain two types of different samples, one from the surface of the steel bar (catalyst) and another from the quartz tube surface (without catalyst) in the same experiment. Carbon spheres were observed in both samples by micrographs obtained by FESEM. The Raman and FTIR spectroscopies shown characteristic bands of this carbon structures (G and D). The results obtained by student's t-test proved a statistical significance between spheres means of samples collected from steel bar and quartz tube surface.

The incorporation of triturated tire particles as an aggregate in the concrete mixture is one of the ways to take advantage of this Waste Rubber (WR) in order to improve concrete properties, such as mechanical behavior. In this research we evaluated mechanical behavior of concrete specimens prepared with different amounts WR, which partially substituted the fine aggregate, under an indirect tensile test. In contrast with other’s researcher’s findings, our results show that the specimens with 5% WR present the highest value of indirect tensile strength (TP) of 4.36 MPa. Polynomial relationships between TP and compression strength (f´c), where Tp ranges from 0.1f´c to 0.2f´c. Specimens with the 0, 5 and 10% WR content show two types of failure: normal tension and tiple-cleft failure, described in the norm ASTM 1144-89. Nevertheless, specimens with 15 and 20% WR show a new failure not described in the norm, which is thought to be occurring due to the high amount of WR used.

Even though AA 7075 is an aluminum alloy with high mechanical properties, it is not often applied in manufacturing. This is so, because it is considered as very difficult to produce defect free welded joints. This is so, because this alloy has a tendency to hot cracking. The metallurgical problems that appear during welding of AA 7075 have not been fully solved but they have been reduced by applying alloys such as: 4043 and 5356 as filler metals. However, in literature there is little information about the metallurgical effects of these types of filler metals applied in arc welded joints of AA7075. This is especially true for Tungsten Inert gas welding. Therefore, this work is focused in comparing the microstructure and Vickers microhardness in weldments of AA 7075 with ER4043, ER5356 and AA7075 as filler metals. Besides, a set of welded joints with the three different filler metals were quenched after welding in order to modify the final microstructure. The results were evaluated by microstructural analysis focused on the Heat Affected Zone and Vickers microhardness and they were compared among them.

PA6 and PMMA polymers with different MWCNTs addition (5, 7 and 9 wt %) were synthetized through casting solution, resulting in improvement properties in contrast to pristine polymers. SEM images showed the MWCNTs embedded into polymeric matrices. D, G and G´ bands of MWCNTs were confirmed by Raman spectroscopy and functional groups observed in both nanocomposites by FTIR demonstrated a strong interaction. A significant increasing in electrical conductivity and microhardness was observed in all the nanocomposites. Major microhardness values were obtained in MWCNTs/PA6 (50 HV) however the MWCNTs/PMMA nanocomposites showed the highest electrical conductivity value (6.4×10-4 S/cm).

The aim of this research is to ameliorate the dispersion of pristine and functionalized Carbon Nanotubes (CNTs) into polystyrene with hydroxyl end groups (PSOH) matrices using low magnetic fields. The Multi-Walled Carbon Nanotubes (MWCNTs) were synthesized by chemical vapor deposition (CVD) using benzene as carbon source; to produce CNTs with and without functional groups two catalysts were used (stainless steel and ferrocene). The obtained nanotubes contained iron nanoparticles inside. PSOH were synthesized using styrene as monomer, azobisisobutyronitrile as initiator and 2-MeOH as chain transfer agent. The MWCNTs-PSOH matrices were formed using 1.6 wt % of carbon nanotubes into PSOH and ultrasonic mixing for 30 min. The mixing materials were poured into containers and dry at room temperature. While the material was drying, constant magnetic fields of 0.24 T were being applied for 50 min. The MWCNTs-PSOH composites were analysed by SEM, FTIR and Raman spectroscopy. SEM micrographs showed that MWCNTs without functional groups were incorporated in the middle of PSOH. The MWCNTs functionalized perform differently; a better dispersion through the entire polymer matrix was achieved, because the polymer embedded the CNTs. FTIR and Raman spectroscopy showed chemical interaction between PSOH and MWCNTs functionalized. The CNTs dispersion into PSOH was ameliorated through the use of low magnetic fields and functionalization.

BaAl2Si2O8 and SrAl2Si2O8 were synthesized by solid-state reaction of stoichiometric mixtures of either BaCO3 or SrCO3 with coal fly ash and Al2O3. The mixtures were mechanically activated in an attrition mill for up to 12 h and then reaction-sintered at 900-1300 °C, aiming to promote the formation of BaAl2Si2O8 and SrAl2Si2O8 as well as the conversion from their hexagonal (Hexacelsian) into their monoclinic (Celsian) forms, which is associated with improved mechanical properties in the sintered materials. Especially in the case of SrAl2Si2O8, the formation of Celsian was favored at relatively low sintering temperatures by increasing milling time. Although only the SrAl2Si2O8 composition was fully converted into Celsian, the Hexacelsian to Celsian conversions obtained for the mechanically-activated BaAl2Si2O8 composition were significantly higher than those previously reported in the literature for this compound. This could be attributed to the use of coal fly ash as raw material, which contains mineralizers that promote the mentioned conversion.

Glass-ceramics of eutectic composition in the wollastonite [W, CaO⋅SiO2]- tricalcium phosphate [TCP, β-Ca3(PO4)2] binary system were synthesized by using the glass-crystallization method. The parent glass was crystalized at 800-1300 °C for 0.5-5 h. The in vitro bioactivity of the synthesized glass-ceramics was tested in Kokubo’s Simulated Body Fluid (SBF) for 7-21 days, at pH = 7.4 and 37 °C. All materials were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS). The results showed that metastable Apatite phase [Ap, Ca10(PO4)6O], plus W and TCP phases expected according to the binary phase diagram, were formed. Ap was the first phase formed at 900 °C/0.5 h, which was followed by formation of W phase at 900 °C/2 h and of TCP phase at 1200 °C/0.5 h. The relative proportion of the formed crystalline phases was a function of heat treatment temperature and time. A eutectic microstructure was obtained for the materials heat-treated at 1300 °C for 2 or 5 h. All glass-ceramics showed the formation of a hydroxyapatite (HAp)-like layer during the in vitro bioactivity tests. After 21 days of soaking in SBF, the samples treated at 1300 °C/5 h showed a behavior similar to that typically shown by Bioeutectic® material, while the materials heat-treated at lower temperatures tended to form denser HAp-like layers, with similar thicknesses but with higher Ca/P molar ratios.

A simulation model is presented, where temperature, phases and internal stresses can be predicted as a function of time during the heating of large steel ingots for forging. Heating cycle measurements and computer simulations are compared for an A105 steel grade 34-Ton tapered ingot. A study of the heat transfer inside a natural gas-fired furnace was carried out to make an estimation of internal stresses due to thermal expansion and phase transformation from α ferrite and pearlite to γ austenite during heating. The model was validated with a second test of an AISI 4330 steel grade 35.4-Ton ingot. The simulation model described can calculate internal stresses in any ingot in order to optimize its heating cycle without compromising ingot internal quality, reducing energy consumption and increasing productivity of the furnace.

We study inclusion indices relative to an interpolation scale. Applications are given to several families of functions spaces.

The illudins are a family of fungal sesquiterpenes that have been studied as anti-tumor agents, and they also have antibacterial activity. Over a four-year period, 25304 fungal isolates (approximately 97% ascomycetes and 3% basidiomycetes), were screened for antibacterial activity against methicillin-resistant Staphylococcus aureus. Illudin-like compounds with antibacterial and cytotoxic activity against tumor cell lines were observed in 10 basidiomycete strains. The isolates were recovered from different types of substrata using indirect methods and only formed sterile mycelia in pure culture. The isolates were genetically related but not identical, based on PCR-based fingerprinting techniques. DNA sequencing of the ITS1-5.8 S-ITS2 region of the strains revealed that nine had identical sequences, indicating that they were conspecific. The sequence of the remaining isolate was 96.34% similar, suggesting that it was a closely related species. The D1–D2 region of the 25 S rRNA gene of the two strain types was also sequenced. Both sequences were 99.39% similar, and Coprinopsis gonophylla (syn. Coprinus gonophyllus) was the closest match for both. Strains were grown in pure culture on a rice-based medium that allowed the development of basidiomata from one culture of the main strain type, which was identified as C. episcopalis, a close relative of C. gonophyllus. Both species (or strain types) produced different types of illudin-like compounds. Three novel illudins (I, I2 and J2) were found to be produced by the cultures identified as C. episcopalis, while only illudinic acid was produced by the other Coprinopsis sp. The taxonomical relationships of the Coprinopsis species identified in this study with other illudin producers previously reported in the literature are discussed.

The problem of domination for positive compact operators between Banach lattices was solved by Dodds and Fremlin in [6]: given a Banach lattice $E$ with order continuous dual norm, an order continuous Banach lattice $F$ and two positive operators $0 \leqslant S \leqslant T : E \longrightarrow F$ , the operator $S$ is compact if $T$ is. A similar problem has been considered in the class of weakly compact operators by Abramovich [1] and in a general form by Wickstead [26]. Precisely, Wickstead's result shows that the operator $S$ is weakly compact if $T$ is whenever one of the following two conditions holds: either $E^{\prime}$ is order continuous or $F$ is order continuous. When it comes to Dunford–Pettis operators, Kalton and Saab [15] have proved that the operator $S$ is Dunford–Pettis if $T$ is, provided that the Banach lattice $F$ is order continuous. On the other hand, Aliprantis and Burkinshaw settled the problem of domination for compact [2] and weakly compact [3] endomorphisms (that is, the case when $E = F$ ). For example, they proved that if either the norm on $E$ or the norm on $E^{\prime}$ is order continuous, then the compactness of $T$ is inherited by the power operator $S^2$ . Also, they showed that, for $E$ an arbitrary Banach lattice, $T$ being compact always implies that $S^3$ is compact. More recently, Wickstead studied converses for the Dodds–Fremlin and Kalton–Saab theorems in [27] and for the Aliprantis–Burkinshaw theorems in [28].

A linear operator between two Banach spaces X and Y is strictly-singular (or Kato) if it fails to be an isomorphism on any infinite dimensional subspace. A weaker notion for Banach lattices introduced in [8] is the following one: an operator T from a Banach lattice X to a Banach space Y is said to be disjointly strictly-singular if there is no disjoint sequence of non-null vectors (xn)n∈ℕ in X such that the restriction of T to the subspace [(xn)∞n=1] spanned by the vectors (xn)n∈ℕ is an isomorphism. Clearly every strictly-singular operator is disjointly strictly-singular but the converse is not true in general (consider for example the canonic inclusion Lq[0, 1][rarrhk ]Lp[0, 1] for 1[les ]p<q<∞). In the special case of considering Banach lattices X with a Schauder basis of disjoint vectors both concepts coincide. The notion of disjointly strictly-singular has turned out to be a useful tool in the study of lattice structure of function spaces (cf. [7–9]). In general the class of all disjointly strictly-singular operators is not an operator ideal since it fails to be stable with respect to the composition on the right.

The aim of this paper is to study when the inclusion operators between arbitrary rearrangement invariant function spaces E[0, 1] ≡ E on the probability space [0, 1] are disjointly strictly-singular operators.

We prove a number of results concerning the embedding of a Banach lattice X into an r. i. space Y. For example we show that if Y is an r. i. space on [0, ∞) which is p-convex for some p > 2 and has nontrivial concavity then any Banach lattice X which is r-convex for some r > 2 and embeds into Y must embed as a sublattice. Similar conclusions can be drawn under a variety of hypotheses on Y; if X is an r. i. space on [0, 1] one can replace the hypotheses of r-convexity for some r > 2 by X ≠ L 2.

We also show that if Y is an order-continuous Banach lattice which contains no complemented sublattice lattice-isomorphic to ℓ 2 X is an order-continuous Banach lattice so that ℓ 2 is not complementary lattice finitely representable in X and X is isomorphic to a complemented subspace of Y then X is isomorphic to a complemented sublattice of YN for some integer N.