Occurrence of heat waves in Triangulo Mineiro and Alto Paranaiba and their effect on milk yield and feed intake in cattle

The aim of this study was to estimate milk production and food consumption during the occurrence of heat waves in the Triangulo Mineiro and Alto Paranaiba, MG by means of bioclimatic zoning based on the Temperature and Humidity Index (THI). Therefore a history of heat wave occurrence between the years 2000-2010 was compiled. The decline in milk production (DMP) and reduced food consumption (RFC) were simulated in cities where periods of heat waves were identified. Frutal and Ituiutaba had the highest rate of heat wave occurrence per year. The DMP and RFC showed bioclimatic differences between the cities of Uberaba, Ituiutaba and Frutal. The cities with the best bioclimatic conditions were Sacramento and Patrocinio, as they presented a THI classified outside of the emergency range, with a night THI of below 76 and without heat waves. Therefore, the occurrence of heat waves can impair food intake and decrease milk production, thereby most effectively demonstrating the effects of thermal stress on dairy cows in the Triangulo Mineiro and Alto Paranaiba, MG region.

Effect of surface and heat treatments on the biaxial flexural strength and phase transformation of a Y-TZP ceramic

To evaluate the effect of grinding and airborne-particle abrasion on the biaxial flexural strength (BFS) and phase transformation of a Y-TZP ceramic, and examine whether sintering the veneering porcelain renders the previous heat treatment recommended by the manufacturer unnecessary. Materials and Methods: Lava zirconia specimens (N = 108) were obtained with the following dimensions: 14.0 mm diameter × 1.3 mm thickness (n = 36) and 14.0 mm × 1.6 mm (n = 72). The thicker specimens were ground with diamond burs under irrigation and received (heat-treated groups) or not (non-heat-treated groups) a heat treatment (1000°C for 30 min) prior to the four firing cycles applied to simulate the sintering of the veneering porcelain. All specimens were air abraded as follows (n = 12): 1) 30-μm silica-modified Al2O3 particles (Rocatec Soft); 2) 110-μm silica-modified Al2O3 particles (Rocatec Plus); and 3) 120-μm Al2O3 particles, followed by Rocatec Plus. Three specimens of each group were analyzed by x-ray diffraction (XRD) to assess the monoclinic phase content (%). The BFS test was performed in a mechanical testing machine (Instron 8874). Data (MPa) were analyzed by two-way ANOVA (grinding × airborne-particle abrasion and heat treatment × airborne-particle abrasion) and Tukey's post-hoc test (α = 0.05). The strength reliability was analyzed using the Weibull distribution. Results: Grinding significantly decreased the BFS of the non-heat-treated groups (p < 0.01). Within the ground groups, the previous heat treatment did not influence the BFS (p > 0.05). Air abrasion only influenced the BFS of the ground/heat-treated groups (p < 0.01). For the non-heat-treated groups, the grinding did not decrease the Weibull modulus (m), but it did decrease the characteristic strength (σ0). For Rocatec Soft and 120-μm Al2O3 particles + Rocatec Plus, the heat-treated groups presented lower m and higher σ0 than the ground/non-heat-treated groups. The independent variables did not seem to influence phase transformation. Air-abraded surfaces presented higher monoclinic zirconia content than the as-sintered and ground surfaces, which exhibited similar content. Conclusion: Even under irrigation, grinding compromised the Y-TZP ceramic strength. The sintering of the veneering porcelain rendered the previous heat treatment recommended by the manufacturer unnecessary. Airborneparticle abrasion influenced the strength of heat-treated zirconia.

Effect of surface and heat treatments on the biaxial flexural strength and phase transformation of a y-tzp ceramic

To evaluate the effect of grinding and airborne-particle abrasion on the biaxial flexural strength (BFS) and phase transformation of a Y-TZP ceramic, and examine whether sintering the veneering porcelain renders the previous heat treatment recommended by the manufacturer unnecessary. Materials and Methods: Lava zirconia specimens (N = 108) were obtained with the following dimensions: 14.0 mm diameter × 1.3 mm thickness (n = 36) and 14.0 mm × 1.6 mm (n = 72). The thicker specimens were ground with diamond burs under irrigation and received (heat-treated groups) or not (non-heat-treated groups) a heat treatment (1000°C for 30 min) prior to the four firing cycles applied to simulate the sintering of the veneering porcelain. All specimens were air abraded as follows (n = 12): 1) 30-μm silica-modified Al2O3 particles (Rocatec Soft); 2) 110-μm silica-modified Al2O3 particles (Rocatec Plus); and 3) 120-μm Al2O3 particles, followed by Rocatec Plus. Three specimens of each group were analyzed by x-ray diffraction (XRD) to assess the monoclinic phase content (%). The BFS test was performed in a mechanical testing machine (Instron 8874). Data (MPa) were analyzed by two-way ANOVA (grinding × airborne-particle abrasion and heat treatment × airborne-particle abrasion) and Tukey's post-hoc test (α = 0.05). The strength reliability was analyzed using the Weibull distribution. Results: Grinding significantly decreased the BFS of the non-heat-treated groups (p < 0.01). Within the ground groups, the previous heat treatment did not influence the BFS (p > 0.05). Air abrasion only influenced the BFS of the ground/heat-treated groups (p < 0.01). For the non-heat-treated groups, the grinding did not decrease the Weibull modulus (m), but it did decrease the characteristic strength (σ0). For Rocatec Soft and 120-μm Al2O3 particles + Rocatec Plus, the heat-treated groups presented lower m and higher σ0 than the ground/non-heat-treated groups. The independent variables did not seem to influence phase transformation. Air-abraded surfaces presented higher monoclinic zirconia content than the as-sintered and ground surfaces, which exhibited similar content. Conclusion: Even under irrigation, grinding compromised the Y-TZP ceramic strength. The sintering of the veneering porcelain rendered the previous heat treatment recommended by the manufacturer unnecessary. Airborneparticle abrasion influenced the strength of heat-treated zirconia.

Effect of post-polymerization heat treatment on a denture base acrylic resin: histopathological analysis in rats

This work examined the histological effects, on the rat palatal mucosa, of a denture base acrylic resin, submitted or not to a post-polymerization heat-treatment. Methods: Fifteen adult female Wistar rats, with sixty days old, weighting 150 g – 250 g were divided in G1: animals being maintained under the same conditions as the experimental groups following described, but without the use acrylic palatal plates (control group); G2: use of heat-polymerized acrylic resin palatal plates made of Lucitone 550; G3: use of palatal plates identical to G2, but subjected to a post-polymerization treatment in a water bath at 55°C for 60 min. The plates covered all the palate and were fixed in the molar region with light-cured resin, thus being kept there for 14 days. After the sacrifice, the palate was removed, fixed in formaldehyde 10% and decalcified with EDTA. Sections were stained using haematoxylin and eosin. Images in duplicate were made from the central region of the cuts, to measure the thickness (μm) of the keratin layers (TKC), epithelium total (TET) and connective tissue (TCC). Statistical analyses were carried out by one-way ANOVA and Tukey post-tests (α=0.05). Results: According to the results there was significant difference in the thickness of keratin between G2 and G3, with G1 having the intermediate value and similar to the other groups. There was a significant difference in the connective tissue with G3 heat treatment it was found to be effective, from the viewpoint of biocompatibility, for the acrylic resin denture base investigated.

Effect of heat-moisture treatment on the structural, physicochemical, and rheological characteristics of arrowroot starch

The effect of heat-moisture treatment on structural, physicochemical, and rheological characteristics of arrowroot starch was investigated. Heat-moisture treatment was performed with starch samples conditioned to 28% moisture at 100℃ for 2, 4, 8, and 16 h. Structural and physicochemical characterization of native and modified starches, as well as rheological assays with gels of native and 4 h modified starches subjected to acid and sterilization stresses were performed. Arrowroot starch had 23.1% of amylose and a CA-type crystalline pattern that changed over the treatment time to A-type. Modified starches had higher pasting temperature and lower peak viscosity while breakdown viscosity practically disappeared, independently of the treatment time. Gelatinization temperature and crystallinity increased, while enthalpy, swelling power, and solubility decreased with the treatment. Gels from modified starches, independently of the stress conditions, were found to have more stable apparent viscosities and higher G' and G″ than gels from native starch. Heat-moisture treatment caused a reorganization of starch chains that increased molecular interactions. This increase resulted in higher paste stability and strengthened gels that showed higher resistance to shearing and heat, even after acid or sterilization conditions. A treatment time of 4 h was enough to deeply changing the physicochemical properties of starch.

Effect of pressure-assisted heat treatment on photoluminescence emission of α-Bi2O3 needles

Materials with high photoluminescence (PL) intensity can potentially be used in optical and electronic devices. Although the PL properties of bismuth(III) oxide with a monoclinic crystal structure (α-Bi2O3) have been explored in the past few years, methods of increasing PL emission intensity and information relating PL emission to structural defects are scarce. This research evaluated the effect of a pressure-assisted heat treatment (PAHT) on the PL properties of α-Bi2O3 with a needlelike morphology, which was synthesized via a microwave-assisted hydrothermal (MAH) method. PAHT caused an angular increase between the [BiO6]-[BiO6] clusters of α-Bi2O3, resulting in a significant increase in the PL emission intensity. The Raman and XPS spectra also showed that the α-Bi2O3 PL emissions in the low-energy region (below ∼2.1 eV) are attributed to oxygen vacancies that form defect donor states. The experimental results are in good agreement with first-principles total-energy calculations that were carried out within periodic density functional theory (DFT).

Effect of heat treatment on microstructure and mechanical properties of Ti-5wt-%Ni alloys for use as biomaterial

Titanium alloys are among the most important and frequently used class of biomaterials. In addition to biocompatibility, it is important that an implant material present satisfactory mechanical properties that allow long term use in the body. To improve such properties, different heat treatments are used, as well as doping with oxygen. The presence of interstitial oxygen in the crystal lattice causes deformation, increases the hardness, and causes modifications in anelasticity, thereby decreasing the elastic modulus. In this study, an alloy was prepared by arc melting precursor metals, heat and mechanically treated, and doped with oxygen, resulting in samples with different processing conditions. In each condition, the alloy was characterised in terms of amount of oxygen, X-ray diffraction, and optical microscopy. In addition, properties of the alloy, such as hardness and elastic modulus, were analysed.

Heat or cold chronic stress affects organ weights and Hsp70 levels in chicken embryos

This study was carried out with the objective of evaluating the effect of heat (38.8 degreesC) or cold (35.8 degreesC) stress on chicken embryo development and tissues Hsp70 levels, after the 13th day of incubation. Embryo weight (percent egg weight), organ weight (percent embryo weight) and Hsp70 levels (ng Hsp70 mug(-1) total protein) in different tissues (liver, breast muscle, heart, lungs, brain and kidney) were studied at the end of incubation. Cold stress induced a lower embryo weight and lower kidney and lungs weights, whereas heart and liver were lighter in heat-stressed embryos. An interaction between temperature and age was obtained only for Hsp70 levels in kidney and heart. Cold-stressed embryos showed higher Hsp70 levels in the brain, lungs and liver; a decrease in brain and breast muscle Hsp70 levels was seen from the 19th to 20th days in control embryos. Hsp70 levels increased with age in kidneys of control embryos and in heart of heat- and cold-stressed embryos. In conclusion, this study showed that chicken embryo organ weights are affected by incubation temperature, and that Hsp70 expression is tissue dependent (higher levels being seen in the brain) being cold-stress more effective in increasing Hsp70 levels in most studied tissues.

Latent heat loss of dairy cows in an equatorial semi-arid environment

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Heat shock proteins (HSP): dermatological implications and perspectives

In recent years, several studies have demonstrated the protective effect of Heat Shock Proteins (HSP) on different organs and tissues under stressful conditions. However, most research explores the performance of those molecular chaperones during immune responses or pathological conditions like cancer, whereas the number of studies related to the performance of HSPs in the skin during diverse natural or physiopathological conditions is very low. Therefore, the aim of this article was to summarize the main concepts concerning the expression and performance of HSPs, from analysis of current medicine and cosmetics publications, as well as exploring the importance of these proteins in the dermatological area in physiological events such as cutaneous aging, skin cancer and wound healing and to present final considerations related to biotechnology performance in this area.

The effect of Eu3+ concentration on the Y2O3 host lattice obtained from citrate precursors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Heat Treatment and Oxygen Doping on the Mechanical Properties and Biocompatibility of Titanium-Niobium Binary Alloys

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxygen dynamics and the effects of heat treatments in SBCO samples investigated by mechanical spectroscopy

The compound SmBa(2)Cu(3)O(7-delta) (SBCO)-obtained by substituting rare-earth Sm for Y in the well-known and most studied YBa(2)Cu(3)O(6+delta) (YBCO)-is potentially attractive to study in order to understand the superconductivity mechanism in physics and in electronic device applications. For SBCO, the possibility of variable stoichiometry and the high mobility of oxygen in CuO(x) planes give rise to a rich phase diagram. This study reports on the effect of heat treatments in an oxygen atmosphere on the anelastic properties of this oxide, in which relaxation processes were observed, attributed to oxygen atom jumps present in the Cu-O planes during the orthorhombic phase.

Metal-insulator transition in Nd1-x Eu-x NiO3 probed by specific heat and anelastic measurements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The benefits of ethanol use for hydrogen production in urban transportation

The purpose of this paper is to describe the benefits of sugar cane ethanol in Brazil, appointing the productivity of this type of fuel based on hectares of plantation, its carbon dioxide cycle and the contribution to reduce the greenhouse effect. In the following step the uses of ethanol for hydrogen production by steam reforming is analyzed and some comparison with natural gas steam reforming is performed. The sugar cane industry in Brazil, in a near future, in the hydrogen era, could be modified according to our purpose, since besides the production of sugar, and ethylic and anhydric alcohol, Brazilian sugar cane industry will also be able to produce biohydrogen.Fuel cells appear like a promising technology for energy generation. Among several technologies in the present, the PEMFC (proton exchange membrane fuel cell) is the most appropriate for vehicles application, because it combines durability, high power density, high efficiency, good response and it works at relatively low temperatures. Besides that it is easy to turn it on and off and it is able to support present vibration in vehicles. A PEMFC's problem is the need of noble catalysts like platinum. Another problem is that CO needs to be in low concentration, requiring a more clean hydrogen to avoid fuel cell deterioration.One part of this paper was developed in Stockholm, where there are some buses within the CUTE (clean urban transport for Europe) project that has been in operation with FC since January 2004. Another part was developed in Guaratingueta, Brazil. Brazil intends to start up a program of FC buses. As conclusion, this paper shows the economical analysis comparing buses moved by fuel cells using hydrogen by different kinds of production. Electrolyze with wind turbine, natural gas steam reforming and ethanol steam reforming. (C) 2009 Elsevier Ltd. All rights reserved.