Modeling hourly diffuse solar-radiation in the city of São Paulo using a neural-network technique

dIn this work, a perceptron neural-network technique is applied to estimate hourly values of the diffuse solar-radiation at the surface in São Paulo City, Brazil, using as input the global solar-radiation and other meteorological parameters measured from 1998 to 2001. The neural-network verification was performed using the hourly measurements of diffuse solar-radiation obtained during the year 2002. The neural network was developed based on both feature determination and pattern selection techniques. It was found that the inclusion of the atmospheric long-wave radiation as input improves the neural-network performance. on the other hand traditional meteorological parameters, like air temperature and atmospheric pressure, are not as important as long-wave radiation which acts as a surrogate for cloud-cover information on the regional scale. An objective evaluation has shown that the diffuse solar-radiation is better reproduced by neural network synthetic series than by a correlation model. (C) 2004 Elsevier Ltd. All rights reserved.

Criteria for the diagnosis of diffuse uterine myohypertrophy

Objectives: Diffuse uterine myohypertrophy (DUMH) is a condition clinically diagnosed by the presence of uterine bleeding, homogeneous and diffuse uterine enlargement, and absence of any myoendometrial cause of bleeding. Since the morphologic criteria for the diagnosis of this entity are still controversial, this study aimed to investigate the clinical presentation and the morphologic findings of the cases of DUMH presenting at the University Hospital of Botucatu, São Paulo, Brazil, Methods: We retrospectively studied 43 consecutive patients with DUMH submitted to hysterectomy (test group) and compared the findings with those obtained from 28 patients submitted to hysterectomy due to a prolapsed uterus (control group). There were no significant differences in age, weight or height between the two groups. Results: the uterine weight of the DUMH group (mean +/- S.D. 157.4 +/- 46.4 g) was significantly heavier than that of the control group (99.5 +/- 35.4 g) and myometrial thickness was significantly greater in the DUMH group (2.5 +/- 0.5 cm) than in the control group (1.9 +/- 0.4 cm). No positive correlation was observed between increased uterine weight and parity, but there was a positive correlation between uterine weight and myometrial thickness. on the basis of the present study, we suggest that the diagnosis of DUMH be made clinically and in cases of uterine weight greater than or equal to 120 g and myometrial thickness greater than or equal to 2.0 cm. In addition, 10 cases of each group were analyzed by morphometry to evaluate interstitial fibrosis and myometrial hypertrophy. The data showed that the increase in uterine weight in DUMH is caused by enlargement of individual myometrial fibers rather than accumulation of interstitial collagen. Conclusion: Discriminant analysis to estimate the diagnostic significance of a number of clinical and pathologic variables (age, parity, uterine weight and morphometric parameters) was able to differentiate cases of DUMH from controls in 100% of the patients.

Global and diffuse solar irradiances in urban and rural areas in southeast Brazil

The seasonal evolution of daily and hourly values of global and diffuse solar radiation at the surface are compared for the cities of São Paulo and Botucatu, both located in Southeast Brazil and representative of urban and rural areas, respectively. The comparisons are based on measurements of global and diffuse solar irradiance carried out at the surface during a six year simultaneous period in these two cities. Despite the similar latitude and altitude, the seasonal evolution of daily values indicate that São Paulo receives, during clear sky days, 7.8% less global irradiance in August and 5.1% less in June than Botucatu. on the other hand, São Paulo receives, during clear sky days, 3.6% more diffuse irradiance in August and 15.6% more in June than Botucatu. The seasonal variation of the diurnal cycle confirms these differences and indicates that they are more pronounced during the afternoon. The regional differences are related to the distance from the Atlantic Ocean, systematic penetration of the sea breeze and daytime evolution of the particulate matter in São Paulo. An important mechanism controlling the spatial distribution of solar radiation, on a regional scale, is the sea breeze penetration in São Paulo, bringing moisture and maritime aerosol that in turn further increases the solar radiation scattering due to pollution and further reduces the intensity of the direct component of solar radiation at the surface. Surprisingly, under clear sky conditions the atmospheric attenuation of solar radiation in Botucatu during winter - the biomass burning period due to the sugar cane harvest - is equivalent to that at São Paulo City, indicating that the contamination during sugar cane harvest in Southeast Brazil has a large impact in the solar radiation field at the surface.

Adherence and experimental infection of bacteria associated with periodontal infections of young cattle in Brazil (Cara inchada)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determination of methyldopa in pharmaceutical formulations by combined spot test-diffuse reflectance spectroscopy

This paper describes a very simple and rapid quantitative reflectance spot test procedure for the determination of methyldopa in pharmaceutical formulations. This method is based on the complexation reaction of methyldopa with molybdate ions yielding a yellow stable complex on filter paper. Reflectance measurements were carried out at 410 nm. Under optimal conditions, the calibration graphs obtained for methyldopa by plotting the optical density of the reflectance signal (A R) vs. the log of the concentration were linear from 6.30 × 10 -3 to 1.89 × 10 -2 mol L -1, with a correlation coefficient of 0.998. The detection limit was 2.74 × 10 -3 mol L -1 (R.S.D. = 1.02%) for methyldopa. The common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method was applied to determine metyldopa in commercial pharmaceutical formulations. The results obtained by the proposed method compare favorably with those obtained by an official procedure at 95% confidence level. ©2006 Sociedade Brasileira de Química.

Antimicrobial activity of coffee-based solutions and their effects on Streptococcus mutans adherence

The aim of this study was to evaluate the antimicrobial activity of different coffee solutions and their effects on the adherence of Streptococcus mutans to glass surface. Coffee solutions were prepared with three commercial products (Pilao, Mellita and Café do Ponto) by two different methods (simple and boiled) (n=15). A control group was also included in the study. For antimicrobial activity testing, tubes containing coffee solution and culture medium were inoculated with a suspension of S. mutans ATCC 35688 and incubated for 1 min 1h, 2h and 4h. Serial dilutions and plating on BHI agar were performed. S, mutans adherence to glass in presence of different coffee solutions was also tested. The number of adhered bacteria (CFU/mL) was determined by plating method. The results were statistically analyzed by ANOVA and Turkey's test. The tested coffee solutions did not reduce the number of colony forming units of S. mutans in relation to the control at all evaluation periods. All the solutions reduced significantly the adherence of S. mutans to the glass surface in relation to control. The tested coffee solutions did not present any antimicrobial effect on Streptococcus mutans, however, all the coffee solutions reduced significantly the adherence of S mutans to the glass surface.

Effects of Coffea arabica on Streptococcus mutans adherence to dental enamel and dentine

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

Determination of atenolol in pharmaceutical formulations by diffuse reflectance spectroscopy

A simple analytical method for quantification of atenolol in pharmaceutical formulations by diffuse reflectance spectroscopy is described. The method is based on the reaction, on the filter paper surface, between the drug and p-chloranil producing a colored compound. The best reaction conditions were obtained with 20 μL of atenolol solution and 20 μL of p-chloranil. All reflectance measurements were carried out at 550 nm and the linear range was from 1.13×10-2 to 7.88×10-2 mol L-1 (r = 0.9992). The limit of detection was 2.80 × 10-3 mol L-1. The proposed method was successfully applied to analysis of different commercial brands of pharmaceutical formulations and the results obtained by the proposed method were in good agreement with those obtained using the British Pharmacopoeia method.

Adherence of Streptococcus mutans to uncoated and saliva-coated glass-ceramics and composites

This study sought to investigate the surface roughness and the adherence of Streptococcus mutans (in the presence and absence of saliva) to ceramics and composites. The early dental biofilms formed in situ on the materials were illustrated, using scanning electron microscopy (SEM). Feldspathic and leucite/feldspathic ceramics and microhybrid and microfilled composites were evaluated. Human dental enamel was used as the control. Standardized specimens of the materials were produced and surface roughness was analyzed. The adhesion tests were carried out in 24-well plates and colony forming units (CFU/mL) were evaluated. Values of roughness (μm) and adherence (CFU/mL) were analyzed statistically. Of all the surfaces tested, enamel was the roughest. Leucite/feldspathic ceramics were rougher than the feldspathic ceramic, while composites were similar statistically. Enamel offered the highest level of adherence to uncoated and saliva-coated specimens, while the leucite/feldspathic ceramic demonstrated greater adherence than the feldspathic ceramic and the composites were similar statically. The rougher restorative materials increased the adherence of S, mutans on the material surfaces.

Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37°C, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative.

Diffuse Effect of the Tungsten Doped Ba(Zr0.10Ti0.90)O3 Ferroelectric Ceramics

Barium zirconate titanate Ba(Ti0.90Zr0.10)O3 ceramics doped with WO3 (BZT:2W) have been prepared by a traditional solid phase reaction. The effect of temperature on the structural and electrical properties was investigated. X ray diffraction data evidenced formation of secondary phases for the samples sintered at 1300oC end 1350oC while the pure phase was attained at 1200oC. A modified Curie-Weiss law was used to describe the diffuseness of a phase transition. As temperature increases, the maximum dielectric permittivity decreased. The fine-grained sample showed a 'diffuse-like' ferroelectric behavior. The dielectric permittivity reaches a maximum value (εm ~6420 at 10 kHz) for the ceramics sintered at 1200oC for 4 hours.

Experimental analysis and adherence test of the electromagnetic zero-sequence blocking model

This paper reveals new contributions to the analysis and development of mitigating harmonic distortion devices. Considering the variety of sequential distribution of harmonic current, in the use of passive filters, one can point out the electromagnetic blocking device, which have received particular attention due to its robustness and low cost of installation. In this context, aiming the evaluation of the reliability of the results obtained through mathematical modeling, experimental tests are carried out using a low-power prototype, highlighting particular aspects related to its function as a zero-sequence harmonic blocking. © 2011 IEEE.

Annual and monthly mean global, direct and diffuse solar irradiation in Botucatu/SP/Brazil

This paper presents a climatic and statistical analysis of global, direct horizontal and diffuse radiation from a database of solar radiation measured from 1996 to 2006 in the city of Botucatu, SP, Brazil. Variation intervals of hourly and daily irradiation, annual mean 〈H̄G〉, 〈H̄bh〉 and 〈H̄d〉 irradiation, monthly mean 〈H̄G〉, 〈H̄ bh〉 and 〈H̄d〉 irradiation and monthly mean 〈K̄t〉, 〈K̄bh〉 and 〈K̄d〉 fractions were determined. Results showed that values of hourly and daily annual mean irradiation were as follows: 〈H̄G〉=1.49MJ/m2 and 〈H̄ G〉=17.74MJ/m2; 〈H̄bh〉=0. 90MJ/m2 and 〈H̄bh〉=10.33MJ/m2 and 〈H̄d〉=0.57 MJ/m2 and 〈H̄d〉=7.09MJ/m2, respectively. Variation intervals of hourly monthly mean irradiation were as follows: 〈H̄G〉 ranged from 1.65MJ/m2 in March to 1.16MJ/m2 in June; 〈H̄bh〉 ranged from 1.06MJ/m2 in April to 0.79MJ/m2 in June, and 〈H̄d〉 ranged from 0.70MJ/m2 in January to 0.37MJ/m2 in June and July. Similarly, daily 〈H̄ G〉 irradiation ranged from 21.35MJ/m2 in November to 12.94MJ/m2 in June; 〈H̄bh〉 ranged from 11.83MJ/m2 in April to 8.49MJ/m2 in June, and 〈H̄d〉 ranged from 10.29MJ/m2 in December to 4.38MJ/m2 in June. Variation intervals of hourly monthly mean fractions were as follows: 〈K̄t〉 ranged from 43.5% in January to 54.2% in April; 〈K̄bh〉 ranged from 33.6% in January to 58.0% in April and 〈K̄d〉 ranged from 66.4% in January to 42.0% in April. In the same way, daily 〈K̄ t〉 fractions ranged from 45.5% in January to 59.8% in August; 〈K̄bh〉 ranged from 38.9% in January to 62.0% in August and 〈K̄d〉 ranged from 61.1% in January to 37.7% in July.

Numerical correction for the diffuse solar irradiance by the melo-escobedo shadowring measuring method

The present paper deals with numerical corrections factors proposed as a function of the clearness index in order to correct the diffuse solar irradiance measured with the Melo-Escobedo Shadowring Measuring Method (ME shadowring). The global irradiance was measured by an Eppley - PSP pyranometer ; direct normal irradiance by an Eppley-NIP pyrheliometer fitted to a ST-3 sun tracking device and the diffuse irradiance by an Eppley-PSP pyranometer fitted to a ME shadowring. The validations were performed by the MBE and RMSE statistical indicators. The results showed that the numerical correction factors were appropriate to correct the shadowring diffuse irradiance.