Sewage sludge coke estimation using thermal analysis

The imposition of more stringent legislation by CETESB in the State of So Paulo (Brazil) governing the disposal and utilization of sewage sludge, coupled with the growth in its generation has prompted a drive for alternative uses of sewage sludge. One option that is especially promising, due to its potential to valorize sludge, is its conversion into carbonaceous adsorbents or coke for industrial effluents treatment. Thus, a methodology is presented to estimate the coke produced from the sludge of a sewage treatment station using thermal analysis. The used sewage sludge, which comes from aerobic treatment, was collected in the wastewater treatment station of Barueri, one of the largest of the So Paulo metropolitan area. The sludge samples were collected, dried, ground, and milled until they passed an ABNT 200 sieve. The inert ambient used during its thermal treatment produces inorganic matter and coke as residual materials. Coke formation occurs in the 200-500 A degrees C range and, between 500 and 900 A degrees C, its thermal decomposition occurs. The highest formation of coke occurs at 500 A degrees C.

Uniaxial stress relaxation measurement in fluoroindate glasses

Glasses of composition 40InF3-20SrF2-16BaF2-20ZnF 2-2GdF3-2NaF (mol%) have been prepared under controlled atmosphere. The time response of the stresses under the application of a constant strain was determined by microellipsometer technique, performed in ambient atmosphere at T < Tg = 294°C. The glasses show a Newtonian behavior at small stress level. During the relaxation process, very small grooves perpendicular to the applied strain appeared on the glass surface and affected its behavior after a time. The formation of these grooves is associated with the ambient atmosphere. Measurements in dry atmosphere showed that humidity was an important parameter in the relaxation process.

Synthesis, characterization and thermal decomposition of [Pd2 (C2-dmba) (μ-SO4) (μ-SO4) SO22]

The bridged sulphate complex [Pd2 (C2,dmba) (μ-SO4) (SO2)2] has been obtained by reacting a saturated solution of SO2 in methanol and the cyclometallated compound [Pd(C2,N-dmba)(μ-N3)]2; (dmba = N,N-dimethylbenzylamine), at room temperature for 24 h. Reaction product was characterized by elemental analysis, NMR comprising 13C{1H} and 1H nuclei and I.R. spectrum's measurements. Thermal behavior has been investigated and residual products identified by X-ray powder diffraction.

Thermal inactivation of Phytophthora nicotianae

Phytophthora nicotianae was added to pasteurized soil at the rate of 500 laboratory-produced chlamydospores per gram of soil and exposed to temperatures ranging from 35 to 53°C for 20 days. The time required to reduce soil populations to residual levels (0.2 propagule per gram of soil or less) decreased with increasing temperatures. Addition of cabbage residue to the soil reduced the time required to inactivate chlamydo spores. Temperature regimes were established to simulate daily temperature changes observed in the field, with a high temperature of 47°C for 3 h/day, and were good estimators of the efficacy of soil solarization for the control of P. nicotianae in soil. Cabbage amendment reduced the time required to inactivate chlamydospores of P. nicotianae and its effect was more pronounced at lower temperature regimes.

Control of thermal damage in grinding by digital signal processing of raw acoustic emission

Grinding process is usually the last finishing process of a precision component in the manufacturing industries. This process is utilized for manufacturing parts of different materials, so it demands results such as low roughness, dimensional and shape error control, optimum tool-life, with minimum cost and time. Damages on the parts are very expensive since the previous processes and the grinding itself are useless when the part is damaged in this stage. This work aims to investigate the efficiency of digital signal processing tools of acoustic emission signals in order to detect thermal damages in grinding process. To accomplish such a goal, an experimental work was carried out for 15 runs in a surface grinding machine operating with an aluminum oxide grinding wheel and ABNT 1045 e VC131 steels. The acoustic emission signals were acquired from a fixed sensor placed on the workpiece holder. A high sampling rate acquisition system at 2.5 MHz was used to collect the raw acoustic emission instead of root mean square value usually employed. In each test AE data was analyzed off-line, with results compared to inspection of each workpiece for burn and other metallurgical anomaly. A number of statistical signal processing tools have been evaluated.

Effect of thermal treatments on tensile strength of commercially cast pure titanium and Ti-6Al-4V alloys

Heating titanium structures is assumed to relieve tensions induced by the casting process as well as possibly optimizing some mechanical properties. The aim of this investigation was to evaluate the effect of thermal treatments on tensile strength of commercially pure titanium (CP Ti) and Ti-6Al-4V alloy. Thirty dumbbell rods, with diameters of 3.0 mm at the central segment and lengths of 42 mm, were cast for each metal using the Rematitan System. CP Ti and Ti-6Al-4V specimens were randomly divided into three groups of ten: a control group that received no thermal treatment and two test groups. One (T1) was heated at 750°C for 2 h and the other (T2) was annealed at 955°C for 1 h and aged at 620°C for 2 h. Tensile strength was measured with a universal testing machine (MTS model 810). Tensile strength means and standard deviations were statistically compared using a Kruskal-Wallis test at a α = 0.05 significance level. No statistically significant differences in tensile strength were observed among CP Ti groups. For the Ti-6Al-4V alloy, the control and T1 groups revealed statistically higher tensile strengths when compared to the T2 group, with no significant difference between the control and T1 groups. © 2005 Springer Science + Business Media, Inc.

Digital monitoring of broiler breeder behavior for assessment of thermal welfare

The assessment of welfare issues has been a challenge for poultry producers, and lately welfare standards needs to be reached in order to agree with international market demand. This research proposes the use of continuous behavior monitoring in order to contribute for assessing welfare. A software was developed using the language Clarium. The software managed the recording of data as well as the data searching in the database Firebird. Both software and the observational methodology were tested in a trial conducted inside an environmental chamber, using three genetics of broiler breeders. Behavioral pattern was recorded and correlated to ambient thermal and aerial variation. Monitoring video cameras were placed on the roof facing the used for registering the bird's behavior. From video camera images were recorded during the total period when the ambient was bright, and for analyzing the video images a sample of 15min observation in the morning and 15 min in the afternoon was used, adding up to 30 min daily observation. A specific model so-called behavior was developed inside the software for counting specific behavior and its frequency of occurrence, as well as its duration. Electronic identification was recorded for 24h period. Behavioral video recording images was related to the data recorded using electronic identification.. Statistical analysis of data allowed to identify behavioral differences related to the change in thermal environment, and ultimately indicating thermal stress and departure from welfare conditions.

Influence of thermal and mechanical cycling on the flexural strength of ceramics with titanium or gold alloy frameworks

Objectives: The aim of this study was to evaluate the effect of thermal and mechanical cycling alone or in combination, on the flexural strength of ceramic and metallic frameworks cast in gold alloy or titanium. Methods: Metallic frameworks (25 mm × 3 mm × 0.5 mm) (N = 96) cast in gold alloy or commercial pure titanium (Ti cp) were obtained using acrylic templates. They were airborne particle-abraded with 150 μm aluminum oxide at the central area of the frameworks (8 mm × 3 mm). Bonding agent and opaque were applied on the particle-abraded surfaces and the corresponding ceramic for each metal was fired onto them. The thickness of the ceramic layer was standardized by positioning the frameworks in a metallic template (height: 1 mm). The specimens from each ceramic-metal combination (N = 96, n = 12 per group) were randomly assigned into four experimental fatigue conditions, namely water storage at 37 °C for 24 h (control group), thermal cycling (3000 cycles, between 4 and 55 °C, dwell time: 10 s), mechanical cycling (20,000 cycles under 10 N load, immersion in distilled water at 37 °C) and, thermal and mechanical cycling. A flexural strength test was performed in a universal testing machine (crosshead speed: 1.5 mm/min). Data were statistically analyzed using two-way ANOVA and Tukey's test (α = 0.05). Results: The mean flexural strength values for the ceramic-gold alloy combination (55 ± 7.2 MPa) were significantly higher than those of the ceramic-Ti cp combination (32 ± 6.7 MPa) regardless of the fatigue conditions performed (p < 0.05). Mechanical and thermo-mechanical fatigue decreased the flexural strength results significantly for both ceramic-gold alloy (52 ± 6.6 and 53 ± 5.6 MPa, respectively) and ceramic-Ti cp combinations (29 ± 6.8 and 29 ± 6.8 MPa, respectively) compared to the control group (58 ± 7.8 and 39 ± 5.1 MPa, for gold and Ti cp, respectively) (p < 0.05) (Tukey's test). While ceramic-Ti cp combinations failed adhesively at the metal-opaque interface, gold alloy frameworks exhibited a residue of ceramic material on the surface in all experimental groups. Significance: Mechanical and thermo-mechanical fatigue conditions decreased the flexural strength values for both ceramic-gold alloy and ceramic-Ti cp combinations with the results being significantly lower for the latter in all experimental conditions. © 2007 Academy of Dental Materials.

Root volume and dry matter of peanut plants as a function of soil bulk density and soil water stress

Soil compaction may be defined as the pressing of soil to make it denser. Soil compaction makes the soil denser, decreases permeability of gas and water exchange as well as alterations in thermal relations, and increases mechanical strength of the soil. Compacted soil can restrict normal root development. Simulations of the root restricting layers in a greenhouse are necessary to develop a mechanism to alleviate soil compaction problems in these soils. The selection of three distinct bulk densities based on the standard proctor test is also an important factor to determine which bulk density restricts the root layer. This experiment aimed to assess peanut (Arachis hypogea) root volume and root dry matter as a function of bulk density and water stress. Three levels of soil density (1.2, 1.4, and 1.6g cm-3), and two levels of the soil water content (70 and 90% of field capacity) were used. Treatments were arranged as completely randomized design, with four replications in a 3×2 factorial scheme. The result showed that peanut yield generally responded favorably to subsurface compaction in the presence of high mechanical impedance. This clearly indicates the ability of this root to penetrate the hardpan with less stress. Root volume was not affected by increase in soil bulk density and this mechanical impedance increased root volume when roots penetrated the barrier with less energy. Root growth below the compacted layer (hardpan), was impaired by the imposed barrier. This stress made it impossible for roots to grow well even in the presence of optimum soil water content. Generally soil water content of 70% field capacity (P<0.0001) enhanced greater root proliferation. Nonetheless, soil water content of 90% field capacity in some occasions proved better for root growth. Some of the discrepancies observed were that mechanical impedance is not a good indicator for measuring root growth restriction in greenhouse. Future research can be done using more levels of water to determine the lowest soil water level, which can inhibit plant growth.

Influence of the degradation on the stress cracking values of high density polyethylene (HDPE) geomembranes after different exposures

This paper presents results from stress cracking (SC) tests performed in both fresh and exposed high density polyethylene (HDPE) geomembranes (GM). The HDPE GMs were exposed to ultraviolet radiation, thermal aging (air oven) and tested for chemical compatibility with sodium hydroxide. Stress cracking tests in both fresh and degraded samples were performed in accordance to ASTM D5397: Notched Constant Tensile Load Test (NCTL) and Single Point-Notched Constant Tensile Load Test (SP-NCTL). The results of the NCTL showed that the geomembrane degradation process can be considered to be a catalyst for the phenomenon of SC because it caused a 50% to 60% reduction in stress crack resistance. The most resistance reduction was observed for the sample under chemical compatibility with sodium hydroxide. For the SP-NCTL, the results showed that the samples maintain the same trend verified in the NCTL. The largest resistance reduction was evidenced in samples undergoing ultraviolet degradation. © 2012 ejge.

Meat quality of young Nellore bulls with low and high residual feed intake

Fifty-nine Nellore bulls from low and high residual feed intake (RFI) levels were studied with the objective of evaluating meat quality traits. Animals were slaughtered when ultrasound-measured backfat thickness reached 4. mm, and samples of Longissimus were collected. A mixed model including RFI as fixed effect and herd and diet as random effects was used, and least square means were compared by t-test. More efficient animals consumed 0.730. kg dry matter/day less than less efficient animals, with similar performance. No significant differences in carcass weight, prime meat cuts proportion, chemical composition, pH, sarcomere length, or color were observed between RFI groups. Shear force, myofibrillar fragmentation index and soluble collagen content were influenced by RFI, with a higher shear force and soluble collagen content and a lower fragmentation index in low RFI animals. Feedlot-finished low RFI young Nellore bulls more efficiently convert feed into meat, presenting carcasses within quality standards. © 2012 Elsevier Ltd.

Photoelastic analysis of the influence of residual ridge inclination in conjugated class i mandibular prostheses with different attachment systems

Objectives: The aim of this study was to evaluate the stress distribution in mandibular free-end removable partial dentures (RPD) associated with FPD in the abutment teeth considering different inclinations of the residual ridge: (1) horizontal and (2) distal descending ridges and two designs of free-end RPD with different attachment systems were tested: (1) clasp and (2) system ERA. Methods. Axial loads (100 N) were applied on the teeth of the RPD. The images were recorded and the stress distribution was evaluated through photoelastic fringes. Results. In general, the distal descending ridge presented more photoelastic fringes in the region of the roots of the abutment teeth while the horizontal ridge exhibited higher compression in the base of the prosthesis. In the horizontal ridge, the denture with clasp presented more favourable stress distribution than the denture with the system ERA. In the distal descending ridge, the denture with the system ERA relieved the region of the abutment teeth and overloaded the residual ridge. Conclusion: The horizontal ridge presented more favourable performance; the dentures with clasp exhibited better performance for both ridges evaluated; the denture with the system ERA presented better results in the distal descending ridge. © 2013 Informa Healthcare.

Influência dos sistemas de retenção e da inclinação do rebordo residual em casos de próteses conjugadas Classe I mandibular: análise da distribuição das tensões pelo método da fotoelasticidade

Pós-graduação em Odontologia - FOA

The thermal stability of yellow fever vaccines

The assessment of yellow fever vaccine thermostability both in lyophilized form and after reconstitution were analyzed. Two commercial yellow fever vaccines were assayed for their thermal stability. Vaccines were exposed to test temperatures in the range of 8 (graus) C to 45 (graus) C. Residual infectivity was measured by a plaque assay using Vero cells. The titre values were used in an accelerated degradation test that follows the Arrhenius equation and the minimum immunizing dose was assumed to be 10 (ao cubo) particles forming unit (pfu)/dose. Some of the most relevant results include that (i) regular culture medium show the same degradation pattern of a reconstituted 17D-204 vaccine; (ii) reconstituted YF-17D-204 showed a predictable half life of more than six days if kept at 0 (graus) C; (iii) there are differences in thermostability between different products that are probably due to both presence of stabilizers in the preparation and the modernization in the vaccine production; (iv) it is important to establish a proper correlation between the mouse infectivity test and the plaque assay since the last appears to be more simple, economical, and practical for small laboratories to assess the potency of the vaccine, and (v) the accelerated degradation test appears to be the best procedure to quantify the thermostability of biological products.

Scrotal Thermography and Doppler Ultrasonography of the Testicular Artery of Buffaloes Subjected to Environmental Heat Stress

The process of spermatic division and differentiation (spermatogenesis) occurs with intratesticular temperature lower that the corporal temperature and for that is essential that the testicular thermoregulation mechanism occurs properly. For evaluation of the scrotal surface temperature can be used the infrared thermography or testicular sensors, besides that, can be evaluated the blood flux in the spermatic cord through the Doppler ultrasonography. Therefore the objective of this study was the evaluation of the scrotal thermography and Doppler flowmetry of the testicular artery of buffaloes subjected to environmental heat stress. For that were used seven healthy buffaloes, with age of 3 and 4 years, of the Murrah breed. For the surface scrotal temperature measurement (SST, degrees C) and superficial neck temperature (SNT, degrees C) was used the infrared termography (Infra Cam (TM) of the brand FLIR Systems Inc.), then Doppler flowmetry of the testicular artery in the region of the spermatic cord through the ultrasonography (Mylab 5, Esaote (R)) and measurement of the rectal temperature (RT, degrees C). The evaluations were done in two moments: moment 1 (M1) with all the animals in the shade (Temperature=32,2 degrees C) and moment 2 (M2) after 3 hours of exposure of animals to the sun (Temperature=38,7 degrees C To calculate the resistivity index (RI) and pulsatility index (PI), spectra were obtained from pulsed Doppler in three random regions of the testicular artery in the spermatic cord. Data were subjected to analysis of variance (ANOVA) followed by T test, using a significance level of 5%. There was an increase (p<0,05) of RT (37,4 +/- 0,4(a) vs 39,0 +/- 0,3(b); M1 and M2 respectively), SST (30,6 +/- 1,4(a) vs 35,2,0 +/- 1,0(b); M1 and M2 respectively) and SNT (33,1 +/- 2,5(a) vs 38,5,0 +/- 0,3(b); M1 e M2 respectively) e RI (0,67 +/- 0,1(a) vs 0,74 +/- 0,1(b); M1 e M2 respectively) in M2. Increasing trend was observed (0,05>p>0,01) in PI (1,10 +/- 0,4(a) vs 1,23 +/- 0,2(b); M1 and M2 respectively) in M2. The results of the present study allow us to conclude the healthy buffaloes have the scrotal average surface temperature 3 degrees C lower that the body temperature and that the exposure of 3 hours to sun in healthy buffaloes causes thermal stress to the animals and changes in its surface scrotal temperature, and the Doppler flowmetry of the testicular artery demonstrating the importance of thermal management for breeding buffaloes. Besides that, the thermography and the Doppler ultrasonography presented great potential to detect changes of testicular perfusion, being a promising additional test in the buffalo andrological evaluation.