Metodologia de análise de risco de investimento em projetos de eficiência energética com aplicação no aproveitamento da biomassa residual do dendê na Amazônia

A promoção das energias renováveis, como estratégias para mitigar as alterações climáticas é um grande desafio mundial, principalmente para países em desenvolvimento como Brasil que busca diversificar sua matriz energética a partir de fontes renováveis, mas possui restrições de custo de investimentos. Neste contexto, são necessárias ferramentas que mensurem os riscos de investimento em projetos de fontes de energia renovável. Este trabalho contribui para o desenvolvimento sustentável da Amazônia através do desenvolvimento de uma metodologia de análise de risco de investimento em projetos de eficiência energética aplicada no aproveitamento da biomassa do dendê. A crescente produção de dendê na região amazônica para geração de produtos alimentícios e biodiesel está gerando um grande volume de biomassa. Verificou-se que a utilização do resíduo da biomassa de dendê para a geração de energia e comercialização no mercado aumenta o seu valor econômico, para tanto se identificou os Critérios e Indicadores (C&I) de sustentabilidade da cadeia do dendê agrupando-os em: econômicos, ambientais, sociais e técnicos. Qualificando e quantificando os riscos que afetam os indicadores identificados. A metodologia desenvolvida foi analisada em três cenários futuros de crescimento econômico para o Brasil que foram construídos balizados nos cenários contidos no Plano Nacional de Energia 2030.

Respiratory muscle activity related to flow and lung volume in preterm infants compared with term infants

Infants with chronic lung disease (CLD) have a capacity to maintain functional lung volume despite alterations to their lung mechanics. We hypothesize that they achieve this by altering breathing patterns and dynamic elevation of lung volume, leading to differences in the relationship between respiratory muscle activity, flow and lung volume. Lung function and transcutaneous electromyography of the respiratory muscles (rEMG) were measured in 20 infants with CLD and in 39 healthy age-matched controls during quiet sleep. We compared coefficient of variations (CVs) of rEMG and the temporal relationship of rEMG variables, to flow and lung volume [functional residual capacity (FRC)] between these groups. The time between the start of inspiratory muscle activity and the resulting flow (tria)--in relation to respiratory cycle time--was significantly longer in infants with CLD. Although FRC had similar associations with tria and postinspiratory activity (corrected for respiratory cycle time), the CV of the diaphragmatic rEMG was lower in CLD infants (22.6 versus 31.0%, p = 0.030). The temporal relationship of rEMG to flow and FRC and the loss of adaptive variability provide additional information on coping mechanisms in infants with CLD. This technique could be used for noninvasive bedside monitoring of CLD.

Lung volume, breathing pattern and ventilation inhomogeneity in preterm and term infants

BACKGROUND: Morphological changes in preterm infants with bronchopulmonary dysplasia (BPD) have functional consequences on lung volume, ventilation inhomogeneity and respiratory mechanics. Although some studies have shown lower lung volumes and increased ventilation inhomogeneity in BPD infants, conflicting results exist possibly due to differences in sedation and measurement techniques. METHODOLOGY/PRINCIPAL FINDINGS: We studied 127 infants with BPD, 58 preterm infants without BPD and 239 healthy term-born infants, at a matched post-conceptional age of 44 weeks during quiet natural sleep according to ATS/ERS standards. Lung function parameters measured were functional residual capacity (FRC) and ventilation inhomogeneity by multiple breath washout as well as tidal breathing parameters. Preterm infants with BPD had only marginally lower FRC (21.4 mL/kg) than preterm infants without BPD (23.4 mL/kg) and term-born infants (22.6 mL/kg), though there was no trend with disease severity. They also showed higher respiratory rates and lower ratios of time to peak expiratory flow and expiratory time (t(PTEF)/t(E)) than healthy preterm and term controls. These changes were related to disease severity. No differences were found for ventilation inhomogeneity. CONCLUSIONS: Our results suggest that preterm infants with BPD have a high capacity to maintain functional lung volume during natural sleep. The alterations in breathing pattern with disease severity may reflect presence of adaptive mechanisms to cope with the disease process.

Lung volume reduction surgery versus conservative treatment in severe emphysema

Lung volume reduction surgery (LVRS) has been proposed for patients with severe emphysema to improve dyspnoea and pulmonary function. It is unknown, however, whether prognosis and pulmonary function in these patients can be improved compared to conservative treatment. The effect of LVRS and conservative therapy were compared prospectively in 57 patients with emphysema, who fulfilled the standard criteria for LVRS. The patients were divided into two groups according to their own decision. Patients in group 1 (n=29, eight females, mean+/-SEM 58.8+/-1.7 yrs, forced expiratory volume in one second (FEV1) 27.6+/-1.3% of the predicted value) underwent LVRS. Patients in group 2 (n=28, five females, 58.5+/-1.8 yrs, FEV1 30.8+/-1.4% pred) preferred to postpone LVRS. There were no significant differences in lung function between the two groups at baseline; however, there was a tendency towards better functional status in the control group. The control group had a better modified Medical Research Council (MMRC) dyspnea score (3.1+/-0.15 versus 3.5+/-0.1, p<0.04). Model-based comparisons were used to estimate the differences between the two groups over 18 months. Significant improvements were observed in the LVRS group compared to the control group in FEV1, total lung capacity (TLC), Residual volume (RV), MMRC dyspnea score and 6-min walking distance on all follow up visits. The estimated difference in FEV1 was 33% (95% confidence interval 13-58%; p>0.0001), in TLC 12.9% (7.9-18.8%; p>0.0001), in RV 60.9% 32.6-89.2%; p>0.0001), in 6-min walking distance 230 m (138-322 m; p<0.002) and in MMRC dyspnoea score 1.17 (0.79-1.55; p<0.0001). In conclusion, lung volume reduction surgery is more effective than conservative treatment for the improvement of dyspnoea, lung function and exercise capacity in selected patients with severe emphysema.

[Bilateral surgical lung volume reduction in severe emphysema]

OBJECTIVE: To report preliminary results with a new surgical method of treating terminal emphysema by bilateral reduction of lung volume. PATIENTS AND METHODS: In a prospective study, the results obtained with the first 20 consecutive patients (mean FEV1: 590 +/- 180 ml) who underwent operative reduction of lung volume were recorded. 19 of the 20 patients had required continuous oxygen supply. RESULTS: The patients were extubated 8.5 +/- 6 h postoperatively; thoracic drainage was removed after 9 +/- 6 days. The degree of dyspnoea was decreased in all patients (3.5 +/- 0.5 vs 0.5 +/- 0.1). Significant reduction of overinflation occurred soon after the operation (residual volume 273 +/- 125 to 201 +/- 107% of normal; total capacity from 142 +/- 18 to 109 +/- 22% of normal), as well as reduction in the degree of obstruction (FEV1 from 18 +/- 6 to 24 +/- 7% of normal; for each, P < 0.05). One patient died 3 weeks post-operatively of Candida infection. CONCLUSION: The method looks promising for the treatment of selected patients and may thus provide an alternative to lung transplantation.

A dual resonance, image -guided, volume localization technique for magnetic resonance spectroscopy

An interleaved, dual resonance, volume localization technique for $\sp1$H/$\sp{31}$P magnetic resonance spectroscopy has been designed, implemented on a 2 T imager/spectrometer, and verified with phantom studies.^ Localization techniques, including several single voxel techniques and spectroscopic imaging, were implemented, and studies were performed to compare the efficiency of each sequence of $\sp1$H/$\sp{31}$P spectral acquisitions. The sequence chosen was a hybrid of the stimulated echo single voxel technique and the spectroscopic imaging technique.^ Water suppression during the $\sp1$H spectral acquisitions was accomplished by the use of three narrow bandwidth RF saturation pulses in combination with three spoiler gradients. The spoiler gradient amplitudes were selected on the basis of a numerical solution of the Bloch equations. A post-acquisition water suppression algorithm was used to minimize any residual water signal.^ For interleaved $\sp1$H/$\sp{31}$P acquisitions, a dual resonance RF coil was constructed and interfaced to the existing RF detection system via a custom-designed dual resonance transcoupler and switching system. Programmable attenuators were incorporated to allow for changes in receiver and transmitter attenuation "on the fly".^ To provide the rapidly switched gradient fields required for the $\sp1$H/$\sp{31}$P acquisitions, an actively screened gradient coil system was designed and implemented. With this system, gradient field rise times on the order of 100 $\mu$s were obtained. These rapid switching times were necessary for minimizing intrasequence delays and for improving localization quality and water suppression efficiency.^ The interleaved $\sp1$H/$\sp{31}$P volume localization technique was tested using a two-compartment phantom. Analysis of the data showed that the spectral contamination was less than three percent. One-to-one spatial correspondence of the $\sp1$H and $\sp{31}$P spectra was verified and allowed for direct correlation of the spectral data with a standard magnetic resonance image. ^

Ocular residual astigmatism and topographic disparity vector indexes in normal healthy eyes

Purpose: To define a range of normality for the vectorial parameters Ocular Residual Astigmatism (ORA) and topography disparity (TD) and to evaluate their relationship with visual, refractive, anterior and posterior corneal curvature, pachymetric and corneal volume data in normal healthy eyes. Methods: This study comprised a total of 101 consecutive normal healthy eyes of 101 patients ranging in age from 15 to 64 years old. In all cases, a complete corneal analysis was performed using a Scheimpflug photography-based topography system (Pentacam system Oculus Optikgeräte GmbH). Anterior corneal topographic data were imported from the Pentacam system to the iASSORT software (ASSORT Pty. Ltd.), which allowed the calculation of the ocular residual astigmatism (ORA) and topography disparity (TD). Linear regression analysis was used for obtaining a linear expression relating ORA and posterior corneal astigmatism (PCA). Results: Mean magnitude of ORA was 0.79 D (SD: 0.43), with a normality range from 0 to 1.63 D. 90 eyes (89.1%) showed against-the-rule ORA. A weak although statistically significant correlation was found between the magnitudes of posterior corneal astigmatism and ORA (r = 0.34, p < 0.01). Regression analysis showed the presence of a linear relationship between these two variables, although with a very limited predictability (R2: 0.08). Mean magnitude of TD was 0.89 D (SD: 0.50), with a normality range from 0 to 1.87 D. Conclusion: The magnitude of the vector parameters ORA and TD is lower than 1.9 D in the healthy human eye.

The effect of caudal block on functional residual capacity and ventilation homogeneity in healthy children

Caudal block results in a motor blockade that can reduce abdominal wall tension. This could interact with the balance between chest wall and lung recoil pressure and tension of the diaphragm, which determines the static resting volume of the lung. On this rationale, we hypothesised that caudal block causes an increase in functional residual capacity and ventilation distribution in anaesthetised children. Fifty-two healthy children (15-30 kg, 3-8 years of age) undergoing elective surgery with general anaesthesia and caudal block were studied and randomly allocated to two groups: caudal block or control. Following induction of anaesthesia, the first measurement was obtained in the supine position (baseline). All children were then turned to the left lateral position and patients in the caudal block group received a caudal block with bupivacaine. No intervention took place in the control group. After 15 nun in the supine position, the second assessment was performed. Functional residual capacity and parameters of ventilation distribution were calculated by a blinded reviewer. Functional residual capacity was similar at baseline in both groups. In the caudal block group, the capacity increased significantly (p < 0.0001) following caudal block, while in the control group, it remained unchanged. In both groups, parameters of ventilation distribution were consistent with the changes in functional residual capacity. Caudal block resulted in a significant increase in functional residual capacity and improvement in ventilation homogeneity in comparison with the control group. This indicates that caudal block might have a beneficial effect on gas exchange in anaesthetised, spontaneously breathing preschool-aged children with healthy lungs.

Residual stress effects during near-threshold fatigue crack growth

The fatigue crack propagation behaviour of a low alloy, boron-containing steel has been examined after austenitizing at 900°C or 1250°C and tempering at a range of temperatures up to 400°C. Fatigue threshold values were found to vary with austenitizing and tempering treatment in a range between 3.3 to 6 MPa √m when tested at a stress ratio (R) of 0.2. Crack propagation rates in the Paris regime were insensitive to heat treatment variations. The crack propagation path was essentially transgranular in all conditions with small regions of intergranular facets appearing at growth rates around the knee of the da/dN vs ΔK curve. The crack front shape showed marked retardation in the centre of the specimen at low tempering temperatures. Experimental determinations and computer predictions of residual stress levels in the specimens indicated that this was due to a central residual compressive stress resulting from differential cooling rates and the volume change associated with the martensite transformation. The results are discussed in terms of microstructural and residual stress effects on fatigue behaviour. © 1987.

Myocardial Extracellular Volume Expansion And The Risk Of Recurrent Atrial Fibrillation After Pulmonary Vein Isolation.

This study tested whether myocardial extracellular volume (ECV) is increased in patients with hypertension and atrial fibrillation (AF) undergoing pulmonary vein isolation and whether there is an association between ECV and post-procedural recurrence of AF. Hypertension is associated with myocardial fibrosis, an increase in ECV, and AF. Data linking these findings are limited. T1 measurements pre-contrast and post-contrast in a cardiac magnetic resonance (CMR) study provide a method for quantification of ECV. Consecutive patients with hypertension and recurrent AF referred for pulmonary vein isolation underwent a contrast CMR study with measurement of ECV and were followed up prospectively for a median of 18 months. The endpoint of interest was late recurrence of AF. Patients had elevated left ventricular (LV) volumes, LV mass, left atrial volumes, and increased ECV (patients with AF, 0.34 ± 0.03; healthy control patients, 0.29 ± 0.03; p < 0.001). There were positive associations between ECV and left atrial volume (r = 0.46, p < 0.01) and LV mass and a negative association between ECV and diastolic function (early mitral annular relaxation [E'], r = -0.55, p < 0.001). In the best overall multivariable model, ECV was the strongest predictor of the primary outcome of recurrent AF (hazard ratio: 1.29; 95% confidence interval: 1.15 to 1.44; p < 0.0001) and the secondary composite outcome of recurrent AF, heart failure admission, and death (hazard ratio: 1.35; 95% confidence interval: 1.21 to 1.51; p < 0.0001). Each 10% increase in ECV was associated with a 29% increased risk of recurrent AF. In patients with AF and hypertension, expansion of ECV is associated with diastolic function and left atrial remodeling and is a strong independent predictor of recurrent AF post-pulmonary vein isolation.

Reference Values For High-density Lipoprotein Particle Size And Volume By Dynamic Light Scattering In A Brazilian Population Sample And Their Relationships With Metabolic Parameters.

Current data indicate that the size of high-density lipoprotein (HDL) may be considered an important marker for cardiovascular disease risk. We established reference values of mean HDL size and volume in an asymptomatic representative Brazilian population sample (n=590) and their associations with metabolic parameters by gender. Size and volume were determined in HDL isolated from plasma by polyethyleneglycol precipitation of apoB-containing lipoproteins and measured using the dynamic light scattering (DLS) technique. Although the gender and age distributions agreed with other studies, the mean HDL size reference value was slightly lower than in some other populations. Both HDL size and volume were influenced by gender and varied according to age. HDL size was associated with age and HDL-C (total population); non- white ethnicity and CETP inversely (females); HDL-C and PLTP mass (males). On the other hand, HDL volume was determined only by HDL-C (total population and in both genders) and by PLTP mass (males). The reference values for mean HDL size and volume using the DLS technique were established in an asymptomatic and representative Brazilian population sample, as well as their related metabolic factors. HDL-C was a major determinant of HDL size and volume, which were differently modulated in females and in males.

Lateral Pterygoid Muscle Volume And Migraine In Patients With Temporomandibular Disorders.

Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher's exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

Photocatalytic Degradation Of Ofloxacin And Evaluation Of The Residual Antimicrobial Activity.

Ofloxacin is an antimicrobial agent frequently found in significant concentrations in wastewater and surface water. Its continuous introduction into the environment is a potential risk to non-target organisms or to human health. In this study, ofloxacin degradation by UV/TiO2 and UV/TiO2/H2O2, antimicrobial activity (E. coli) of samples subjected to these processes, and by-products formed were evaluated. For UV/TiO2, the degradation efficiency was 89.3% in 60 min of reaction when 128 mg L(-1) TiO2 were used. The addition of 1.68 mmol L(-1) hydrogen peroxide increased degradation to 97.8%. For UV/TiO2, increasing the catalyst concentration from 4 to 128 mg L(-1) led to an increase in degradation efficiency. For both processes, the antimicrobial activity was considerably reduced throughout the reaction time. The structures of two by-products are presented: m/z 291 (9-fluoro-3-methyl-10-(methyleneamino)-7-oxo-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid) and m/z 157 ((Z)-2-formyl-3-((2-oxoethyl)imino)propanoic acid).