Liquid-Liquid Equilibrium of Sesame Fatty Acid (Ethyl and Methyl) Ester + Glycerol + Ethanol/Methanol Mixtures at Different Temperatures.

This study aimed to investigate the liquid-liquid equilibrium (LLE) behavior of sesame fatty acid ethyl ester (FAEE) and methyl ester (FAME) in combination with glycerol and the co-solvents ethanol and methanol. FAEE and FAME were produced through the transesterification of mechanically extracted and purified sesame oil, using potassium hydroxide (KOH) as a homogeneous base catalyst. The reactions were conducted in ethanol and methanol to produce FAEE and FAME, respectively. Post-reaction, the products were separated and purified, followed by an analysis of the LLE behavior at 313.15 K and 323.15 K under atmospheric pressure (101.3 kPa). The experimental process for the miscibility analysis utilized a jacketed glass cell adapted for this study. Miscibility limits or binodal curves were determined using the turbidity-point method. Tie lines were constructed by preparing mixtures of known concentrations within the two-phase region, which allowed the phases to separate after agitation. Samples from both phases were analyzed to determine their composition. This study revealed that higher temperatures promoted greater phase separation and enhanced the biodiesel purification process. The NRTL model effectively correlated the activity coefficients with the experimental data, showing good agreement, with a root-mean-square deviation of 3.5%. Additionally, the data quality was validated using Marcilla's method, which yielded an R2 value close to 1. Attraction factors and distribution coefficients were also calculated to evaluate the efficiency of the co-solvents as extraction agents. The findings indicated higher selectivity for methanol than for ethanol, with varying degrees of distribution among the co-solvents. These results offer significant insights into enhancing biodiesel production processes by considering the effects of co-solvents on the LLE properties of mixtures, ultimately contributing to more efficient and cost-effective biodiesel production.

A Review of EPDM (Ethylene Propylene Diene Monomer) Rubber-Based Nanocomposites: Properties and Progress.

Ethylene propylene diene monomer (EPDM) is a synthetic rubber widely used in industry and commerce due to its high thermal and chemical resistance. Nanotechnology has enabled the incorporation of nanomaterials into polymeric matrixes that maintain their flexibility and conformation, allowing them to achieve properties previously unattainable, such as improved tensile and chemical resistance. In this work, we summarize the influence of different nanostructures on the mechanical, thermal, and electrical properties of EPDM-based materials to keep up with current research and support future research into synthetic rubber nanocomposites.

Online yarn hairiness- Loop & protruding fibers dataset.

This paper introduces an online dataset focused on detecting hairiness in yarn, including loop and protruding fibers. The dataset is designed for use in assessing artificial intelligence algorithms. The dataset consists of 684 original images. Through augmentation, this number increases to 1644, with 11,037 annotations derived from videos featuring 56.4tex purple cotton yarn. The videos were captured during the winding and unwinding processes of the purple yarn coil. An image acquisition system capable of capturing high-resolution images while the yarn is in motion was used, reaching speeds of up to 4.2 m/s and producing images with a resolution of 1.6M pixels. This dataset containing 100m of purple cotton yarn images was recorded and is available for download in various formats, including, among others, YOLOv8, YOLOv5, YOLOv7, MT-YOLOv6, COCO JSON, YOLO Darknet, Pascal VOC XML, TFRecord, CreateML JSON. Within an interface developed for a designed mechatronic prototype, users can choose to gather images or videos of yarn. Various characteristics of the yarn, such us: diameter, linear mass, volume, twist orientation, twist step, number of cables, hairiness index, number of loose fibers, thin places, thick places, neps (mass parameters) and U, CV and sH (statistical parameters) can be obtained. Recently, this online yarn spinning dataset was employed to validate artificial neural network models for real-time detection of hairiness in yarns, including loop fibers and protruding fibers. The dataset presented, with its clear annotations and wide array of augmentation techniques, serves as a foundational resource for prospective studies in textile engineering, enabling progress in the analysis and comprehension of yarn analysis.

Attenuation photochemical potential of Pontal of Paranapanema river waters (Brazil) from agrochemicals: geographical and temporal assessment.

Knowledge of the environmental photochemical fate of pesticides is essential to assess their potential impacts. However, there are few studies in the literature focused on the photochemical attenuation of micropollutants in Brazilian rivers. In this context, this study characterized the surface waters of the Pontal of Paranapanema region (region which concentrates more than 80% of Brazilian sugarcane cultivations), in order to determine its photochemical attenuation potential against micropollutants in different seasons. Thus, the steady-state concentrations of the photochemically produced reactive intermediates (PPRIs) (hydroxyl radical, HO•; singlet oxygen, 1O2, and triplet-excited state chromophoric dissolved organic matter, 3CDOM*), formed in the rivers, were simulated by using the APEX model (Aquatic Photochemistry of Environmentally-occurring Xenobiotics), considering the sunlight irradiance, water chemistry, and depth. Based on our simulations, these concentrations vary between 0.35 × 10-15 and 4.52 × 10-14 mol L-1 for HO•, 1.3 × 10-15 and 1.2 × 10--14 mol L-1 for 3CDOM*, and 2.5 × 10-15 and 2.5 × 10-14 mol L-1 for 1O2. Finally, mathematical simulations were used for predicting persistence of pesticides atrazine (ATZ) and diuron (DIR) in Pontal of Paranapanema surface waters and the half-life times (t1/2) of the pollutants ranged from a few hours to one week.

Using Object Detection Technology to Identify Defects in Clothing for Blind People.

Blind people often encounter challenges in managing their clothing, specifically in identifying defects such as stains or holes. With the progress of the computer vision field, it is crucial to minimize these limitations as much as possible to assist blind people with selecting appropriate clothing. Therefore, the objective of this paper is to use object detection technology to categorize and detect stains on garments. The defect detection system proposed in this study relies on the You Only Look Once (YOLO) architecture, which is a single-stage object detector that is well-suited for automated inspection tasks. The authors collected a dataset of clothing with defects and used it to train and evaluate the proposed system. The methodology used for the optimization of the defect detection system was based on three main components: (i) increasing the dataset with new defects, illumination conditions, and backgrounds, (ii) introducing data augmentation, and (iii) introducing defect classification. The authors compared and evaluated three different YOLOv5 models. The results of this study demonstrate that the proposed approach is effective and suitable for different challenging defect detection conditions, showing high average precision (AP) values, and paving the way for a mobile application to be accessible for the blind community.

Optimization Studies and Compositional Oil Analysis of Pequi (Caryocar brasiliense Cambess) Almonds by Supercritical CO2 Extraction.

Caryocar brasiliense Cambess (pequi) is the fruit of the pequizeiro tree found in the Brazilian Cerrado (savanna). Supercritical fluids have been used to effectively extract bioactive chemicals. In light of the paucity of research on the supercritical extraction of pequi, in this study, experimental tests were conducted on the extraction of pequi almond oil using supercritical CO2; the optimal extraction conditions were determined, and the fatty acids and active compounds in the oil were characterized. The experiments were conducted using the Box-Behnken experimental design of a three-variable system: pressure (15, 20, and 25 MPa), temperature (303.15, 318.15, and 333.15 K), and flow rate (2, 3, and 5 g.min-1). The optimal extraction conditions were 318.15 K, 25 MPa, and 5.0 g.min-1, which yielded 27.6 wt% of oil. The experimental kinetic curves were described using a second-order quadratic model (based on the Sovová model), which demonstrated a satisfactory correspondence with the kinetic curves. Significant amounts of squalene, stigmasterol, oleic fatty acids, and palmitic fatty acids were detected in pequi almond oil.

Sustainable removal of nitrite waste to value-added ammonia on Cu@Cu2O core-shell nanostructures by pulsed laser technique.

The biochemical reduction of nitrite (NO2-) ions to ammonia (NH3) requires six electrons and is catalyzed by the cytochrome c NO2- reductase enzyme. This biological reaction inspired scientists to explore the reduction of nitrogen oxyanions, such as nitrate (NO3-) and NO2- in wastewater, to produce the more valuable NH3 product. It is widely known that copper (Cu)-based nanoparticles (NPs) are selective for the NO3- reduction reaction (NO3-RR), but the NO2-RR has not been well explored. Therefore, we attempted to address the electrocatalytic conversion of NO2- to NH3 using Cu@Cu2O core-shell NPs to simultaneously treat wastewater by removing NO2- and producing valuable NH3. The Cu@Cu2O core-shell NPs were constructed using the pulsed laser ablation of Cu sheet metal in water. The core-shell nanostructure of these particles was confirmed by various characterization techniques. Subsequently, the removal of NO2- and the ammonium (NH4+)-N yield rate were estimated using the Griess and indophenol blue methods, respectively. Impressively, the Cu@Cu2O core-shell NPs exhibited outstanding NO2-RR activity, demonstrating a maximum NO2- removal efficiency of approximately 94% and a high NH4+-N yield rate of approximately 0.03 mmol h-1.cm-2 at -1.6 V vs. a silver/silver chloride reference electrode under optimal conditions. The proposed NO2-RR mechanism revealed that the (111) facet of Cu favors the selective conversion of NO2- to NH3 via a six-electron transfer. This investigation may offer a new insight for the rational design and detailed mechanistic understanding of electrocatalyst architecture for the effective conversion of NO2- to NH4+.

Co(II), Ni(II), and Zn(II) complexes based on new hybrid imine-pyrazole ligands: structural, spectroscopic, and electronic properties.

The present work reports the theoretical investigation of Co(II), Ni(II), and Zn(II) complexes containing Schiff bases (used as ligands) derived from the reaction of 2-hydroxy-1-naphthaldehyde with N-(2-aminoethyl) pyrazoles. The spectral analyses were carried out using infrared, Raman, and UV-Vis spectroscopy. Vibrational analyses were performed in order to investigate the mechanisms involving metal-ligand and intra-ligand vibrations and indicated the possibility of charge transfer related to the transitions n[Formula: see text]* and [Formula: see text]*. Structure optimizations and normal coordinate force field calculations were performed via the density functional theory (DFT) method at the HSE06/6-311G(d,p)/LanL2DZ level. A thorough analysis was also conducted regarding the nonlinear optical (NLO) properties and the natural bond orbital (NBO) of the complexes. The results show that these complexes have prospective application as materials for NLO. Furthermore, the NBO analysis confirms the coordination between the lone pair (LP) electrons of the donor atoms (O and N) and the metal acceptors. Finally, studies were conducted regarding the electronic properties of the complexes; among the properties investigated included the frontier molecular orbitals (FMO) and the molecular electrostatic potential (MEP), allowing to determine the energy gap and charge distribution.

Laser-photobiomodulation on titanium implant bone healing in rat model: comparison between 660- and 808-nm wavelength.

Laser-photobiomodulation (L-PBM) has been widely studied and its biomodulatory effects have been established on irradiated cells, increasing viability and proliferation and on damaged tissues. In addition, L-PBM may reduce and modulate the inflammatory process. The effect of 660-nm and 808-nm laser-photobiomodulation on bone repair around titanium dental implants placed in rat's femur was evaluated by histomorphometry. Twenty-seven Wistar rats were divided into 3 groups of nine animals: group C - non-irradiated control; group R - λ=660nm irradiated; and group IR - λ=808nm irradiated. Each group was further divided in 3 subgroups of three animals each, according to histomorphometry analysis in 3 days, 7 days, and 14 days after irradiation. Histological H.E.-stained slides were photographed, and bone matrix measured in new-formed bone area. Bone matrix histomorphometry analysis indicates that at 7 days in the irradiated groups (R and IR), a bigger area matrix was observed in relation to control group (C) (p=0.04 and p=0.048 respectively). On the other hand, at 14 days, control group (C) presented a bigger area than infrared irradiated (IR) (p=0.001) and red irradiated group (R) also showed a bigger area than infrared irradiated group (IR) (p=0.019). Histological analysis indicates that irradiated groups (R and IR) exhibited a faster bone tissue matrix production than control group.

Assessment of black liquor hydrothermal treatment under sub- and supercritical conditions: Products distribution and economic perspectives.

This study reports an alternative method for black liquor treatment with potential for energy and process savings in the paper and pulp industry. Gasification of black liquor was carried out under sub- and supercritical conditions, varying the black liquor feed composition (0.10, 2.55 and 5.00 wb%) and temperature (350, 425 and 500 °C). Liquid products were identified by high resolution mass spectrometry (FT-Orbitrap MS) and compounds belonging to classes O3 and O4 were found to be the most representative in the products of reactions performed at 500 °C. The mass spectra results also revealed the overall selectivity of reactions, where decarboxylation and demethoxylation reactions were favored under subcritical and supercritical conditions, respectively. Among the gaseous products, hydrogen and methane were produced with maximum of 69.04 and 28.75 mol%, respectively, at 2.55 wb% and 425 °C. The proposed thermodynamic modelling of the reaction system satisfactorily predicted the gas phase behavior of the system. In the economic analysis, the simulated conditions indicated that the main energy requirements for a scaled-up black liquor gasification process are related to the necessary heat exchangers and pressurizing of the black liquor solution. Furthermore, the cost of the black liquor gasification is around 0.06 US$ per kg of feed stream. Liquid and gaseous products from gasification could be obtained at a cost of 56.64 US$ and 3.35 US$ per tonne of stream, respectively. Therefore, black liquor gasification is an interesting route for obtaining combustible gases and value-added bioproducts.

Non-noble metal (Ni, Cu)-carbon composite derived from porous organic polymers for high-performance seawater electrolysis.

The hydrothermal preparation of o-dianisidine and triazine interlinked porous organic polymer and its successive derivatisation via metal infusion (Ni, Cu) under hydrothermal and calcination conditions (700 °C) to yield pristine (ANIPOP-700) and Ni/Cu decorated porous carbon are described here (Ni-ANIPOP-700 and Cu-ANIPOP-700). To confirm their chemical and morphological properties, the as-prepared materials were methodically analyzed using solid state 13C and 15N NMR, X-ray diffraction, Raman spectroscopy, field emission scanning and high resolution transmission electron microscopic techniques, and x-ray photoelectron spectroscopy. Furthermore, the electrocatalytic activities of these electrocatalysts were thoroughly investigated under standard oxygen evolution (OER) and hydrogen evolution reaction (HER) conditions. The results show that all of the materials demonstrated significant activity in water splitting as well as displayed excellent stability (22 h) in both acidic (HER) and basic conditions (OER). Among the electrocatalysts reported in this study, Ni-ANIPOP-700 exhibited a lower overpotential η10 of 300 mV in basic medium (OER) and 150 mV in acidic medium (HER), as well as a lower Tafel slope of 69 mV/dec (OER) and 181 mV/dec (HER), indicating 30% lower energy requirement for overall water splitting. Gas chromatography was used to examine the electrolyzed products.

Cardiac autonomic modulation response and functional capacity in older women / Respuesta de la modulación autonómica cardíaca y capacidad funcional en mujeres mayores / Resposta da modulação autonômica cardíaca e capacidade funcional em mulheres idosas

ABSTRACT Objective: To analyze cardiac autonomic modulation response and functional capacity in physically active older women. Methods: Seventy-five older women (60-70 years) from the community were divided into the following groups: sedentary (n=19), hydro-gymnastics (n=18), pilates (n=19), and dance (n=19). Blood pressure, body composition, heart rate variability, and functional capacity were assessed for the characterization of the groups at rest and 48 hours after the last physical exercise session. Results: The sedentary group presented higher waist-to-hip ratio, diastolic blood pressure, and resting heart rate compared to the other groups (p<0.05). It was also observed that the dance group presented better functional capacity and VO2peak scores (all p<0.05). Regarding cardiac autonomic modulation, both dance and pilates groups demonstrated better RMSSD (26.71 ± 9.07 and 29.82 ± 7.16, respectively; p<0.05), LF (45.79 ± 14.81 and 45.95 ± 15.16 n.u., respectively; p<0.05), and LF/HF (0.92 ± 0.56 and 0.58 ± 0.26, respectively; p<0.05) scores. In the symbolic analysis, the dance group had a greater predominance of parasympathetic autonomic modulation than the other groups (p<0.05). Conclusion: These results conclude that physically active elderly women, practicing hydro-gymnastics, pilates or dance, presented physiological benefits, such as better functional capacity and improvements in hemodynamic variables and autonomic cardiac modulation. In addition, the group that practiced dance presented greater parasympathetic modulation, as well as greater functional capacity, when compared to the other modalities. Level of evidence: I; STARD: studies of diagnostic accuracy.

RESUMEN Objetivo: Analizar la respuesta de la modulación autonómica cardíaca y la capacidad funcional en mujeres mayores físicamente activas. Métodos: Setenta y cinco mujeres mayores (60 a 70 años) de la comunidad fueron divididas en los siguientes grupos: sedentaria (n = 19), hidrogimnasia (n = 18), pilates (n = 19) y danza (n = 19). La presión arterial, la composición corporal, la variabilidad de la frecuencia cardíaca y la capacidad funcional fueron evaluadas para la caracterización de los grupos en reposo y 48 horas después de la última sesión de ejercicio físico. Resultados: El grupo sedentario presentó mayor relación cintura-cadera, presión arterial diastólica y frecuencia cardíaca en reposo cuando comparado a los otros grupos (p <0,05). Se observó que el grupo de danza presentó mejores puntajes de capacidad funcional y VO2Pico (todos p <0,05). Con relación a la modulación autonómica cardíaca, los grupos de danza y pilates demostraron mejores puntajes para RMSSD (26,71 ± 9,07 y 29,82 ± 7,16, respectivamente; p <0,05), LF (45,79 ± 14,81 y 45,95 ± 15,16 nu, respectivamente; p <0,05), y LF/HF (0,92 ± 0,56 y 0,58 ± 0,26, respectivamente; p <0,05). En el análisis simbólico, el grupo de danza presentó mayor predominancia de la modulación autonómica parasimpática que los demás grupos (p <0,05). Conclusión: Esos resultados concluyen que las mujeres mayores físicamente activas, practicantes de hidrogimnasia, pilates o danza, tienen beneficios fisiológicos, como mejor capacidad funcional y mejora de las variables hemodinámicas y de la modulación cardíaca autonómica. Además, el grupo que practicaba danza tuvo mayor modulación parasimpática y mayor capacidad funcional cuando comparado con las otras modalidades. Nivel de evidencia: I; STARD: estudios de precisión diagnóstica.

RESUMO Objetivo: Analisar a resposta da modulação autonômica cardíaca e a capacidade funcional em idosas fisicamente ativas. Métodos: Setenta e cinco mulheres idosas (60 a 70 anos) da comunidade foram divididas nos seguintes grupos: sedentária (n = 19), hidroginástica (n = 18), pilates (n = 19) e dança (n = 19). A pressão arterial, a composição corporal, a variabilidade da frequência cardíaca e a capacidade funcional foram avaliadas para a caracterização dos grupos em repouso e 48 horas depois da última sessão de exercício físico. Resultados: O grupo sedentário apresentou maior relação cintura-quadril, pressão arterial diastólica e frequência cardíaca em repouso quando comparado aos outros grupos (p <0,05). Observou-se também que o grupo da dança apresentou melhores escores de capacidade funcional e VO2pico (todos p < 0,05). Com relação à modulação autonômica cardíaca, os grupos de dança e pilates demonstraram melhores escores para RMSSD (26,71 ± 9,07 e 29,82 ± 7,16, respectivamente; p < 0,05), LF (45,79 ± 14,81 e 45,95 ± 15,16 nu, respectivamente; p<0,05) e LF/HF (0,92 ± 0,56 e 0,58 ± 0,26, respectivamente; p < 0,05). Na análise simbólica, o grupo da dança apresentou maior predominância da modulação autonômica parassimpática do que os demais grupos (p < 0,05). Conclusão: Esses resultados concluem que idosas fisicamente ativas praticantes de hidroginástica, pilates ou dança, têm benefícios fisiológicos, como melhor capacidade funcional e melhora das variáveis hemodinâmicas e da modulação cardíaca autonômica. Além disso, o grupo que praticava dança teve maior modulação parassimpática e maior capacidade funcional quando comparado com outras modalidades. Nível de evidência: I; STARD: estudos de precisão diagnóstica.

Acute Effects of Resistance Exercise With Blood Flow Restriction in Elderly Women: A Pilot Study.

AIM: To compare the acute effects of two resistance exercise sessions with different partial blood flow restrictions (BFR) on hemodynamic parameters and cardiac autonomic modulation in older women with metabolic syndrome. METHODS: Thirty-nine older women (64.4 ± 4.5 years) were allocated into three groups: BFR0 = resistance exercise (20%, 1 maximum repetition [MR]) + 0% BFR; BFR60 = 20% 1 MR resistance exercise + 60% BFR; and BFR80 = 20% 1MR resistance exercise + 80% BFR. RESULTS: A reduction of 14 mmHg (BFR60 group) and 13 mmHg (BRF80 group) was observed 48 hr after the first exercise session, while vagal modulation was increased in the BRF60 group after 24 and 48 hr. CONCLUSION: A low-intensity resistance exercise session with 60% and 80% of BFR resulted in blood pressure (systolic, diastolic, and mean) reduction and positive changes on heart rate variability after 24 h of a RE session.

Influence of Family History of Diabetes on Cardiac Autonomic Dysfunction of Adolescents

Abstract Background To evaluate cardiac autonomic modulation of adolescents with a family history of diabetic parents. Objective This study aims to evaluate the influence of a family history of diabetes on cardiac autonomic modulation. Methods This is an analytical and cross-sectional study on adolescents between 11 and 18 years of age, of both genders, who were divided into group with a family history of diabetes and a control group without a family history of diabetes. The study protocol consisted of the analysis of heart rate variability, blood pressure, anthropometric measurements, and body composition. Also, by using questionnaires, level of physical activity, sexual maturation, and sleep quality were evaluated. Normality of data distribution was tested using the Kolmogorov-Smirnov test. Then, statistical significance was evaluated using the Student's t-test, and the Cohen's teste was used for calculation of the effect size. The level of significance adopted in the statistical analysis was 5%. Results When the group of individuals with a family history of diabetes was compared with the control group, statistically significant differences were observed in the variables the standard deviation of the NN time series interval (SDNN) (43.9 ± 2.2 vs. 53.5 ± 2.6 ms), the square root of the quadratic differences (RMSSD) (41.9 ± 3.3 vs. 52.4 ± 3.2 ms), standard deviation of beat-to-beat instantaneous variability (SD1) (29.7 ± 2.3 vs. 37.1 ± 2.3 ms), long-term standard deviation of continuous RR intervals (SD2) (. 54.1 ± 2.6 vs. 66.66 ± 3.5 ms), and in low frequency (LF) (496.0 ± 49.5 vs. 728 ± 71.6 ms2) and high frequency (HF) (1050.0 ± 120.4 vs. 737.4 ± 98.5 ms2) in the frequency domain. Conclusions Global autonomic modulation is decreased in adolescents with a family history of diabetes. We also observed a decrease in vagal activity in this group. So, sympathetic autonomic modulation is predominant in this population. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Oxygen Reduction Reaction on a CuII Complex of 3,5-Diamino-1,2,4-triazole: A DFT Approach.

The high costs for producing catalysts for fuel cells combined with low efficiency in oxygen reduction make metal-organic complexes a promising alternative to noble-metal catalysts. The electrochemical activity of Cu-complex-based catalysts has been reported by many authors, but only a few works are devoted to theoretical studies. In this manuscript, we use density functional theory (DFT) calculations to investigate the oxygen reduction reaction (ORR) on a CuII complex of 3,5-diamino-1,2,4-triazole. The determining steps for the associative and dissociative mechanisms are the oxygen adsorption and the oxygen bond cleavage, respectively. The barrier for breaking the O-O bond in the dissociative mechanism was estimated at 0.7 eV.

Land-use effect on hydropedology in a mountainous region of Southeastern Brazil / Efeito do uso do solo na hidropedologia em uma região montanhosa do sudeste do Brasil

ABSTRACT In Brazil, the Mantiqueira Range, southeastern region, shelters the last remnants of the ecologically important Upper Montane Tropical Forest. since extensive exploration that has been taking place in this biome for decades, the influence of land-use changes on hydropedology in these areas must be investigated once major land-use changes have been observed. This study aims to evaluate the land-use influence on soil drainable porosity (SDP) in a headwater watershed located in the Mantiqueira Range region, and to validate the proposed methods based on micromorphological and hydrological indicators. The native vegetation of the study area is Atlantic forest that occupies 62% of the area, and the remaining 38% has been used for pasture. Thirty nine combinations of environmental variables were tested, each one generating a map for predicting SDP. The performance of the spatial prediction of SDP was assessed using 20% of the data from the total number of samples collected throughout the watershed. The least values of SDP are due to the process of removal of native forest and replacement by pasture. Areas with high to moderate SDP are associated with native forest fragments demonstrating the effects of the Atlantic Forest on the water infiltration and groundwater recharge processes, given by the greater contribution of baseflow in a forested catchment located within the studied watershed. The analysis of soil micromorphological images provided useful supporting information on the soil porosity system and along with hydrological properties of the watershed helped understand the SDP behavior on subsurface and groundwater storage capacity.

RESUMO No Brasil, a Serra da Mantiqueira, abriga um dos últimos remanescentes da Floresta Tropical de Altitude. Devido a grande exploração que vem ocorrendo neste bioma há décadas, a influência na hidropedologia decorrente das mudanças do uso do solo deve ser investigada. O objetivo deste estudo foi avaliar a influência do uso do solo na porosidade drenável do solo (PDS) em uma bacia hidrográfica localizada na região da Serra da Mantiqueira e validar os métodos propostos com base em indicadores micromorfológicos e hidrológicos. A vegetação nativa da área de estudo é a Mata Atlântica que ocupa 62% da área, e com os 38% restantes utilizados para pastagem. Trinta e nove combinações de variáveis ​​ambientais foram testadas, cada uma gerando um mapa para predizer a PDS. O desempenho da predição espacial da PDS foi avaliado utilizando 20% dos dados do número total de amostras coletadas em toda a bacia hidrográfica. Os menores valores de PDS são devidos ao processo de remoção de floresta nativa e substituição por pastagem. Áreas com altos a moderados valores de PDS estão associadas a fragmentos de florestas nativas que demonstram os efeitos da Mata Atlântica nos processos de infiltração de água e de recarga de água subterrânea na região da Mantiqueira, dada a maior contribuição do fluxo base em áreas florestadas. A análise micromorfológica do solo forneceu informações úteis sobre o sistema poroso do solo e as propriedades hidrológicas da bacia hidrográfica, ajudando a entender o comportamento da PDS e a capacidade de armazenamento em subsuperfícíe.

Influence of Screw Surface Treatment on Retention of Implant-Supported Fixed Partial Dentures.

The aim of this study was to assess the effect of a diamond-like carbon (DLC) coating on the removal torque of prefabricated implant screws after cyclic loading. Four groups with two crowns supported by two implants (n = 5) were obtained according to splinted and nonsplinted prosthesis, using titanium or DLC screws (splinted crowns with titanium screw [STi], splinted crowns with DLC screw [SC], nonsplinted crowns and titanium screw [NSTi], and nonsplinted crowns and DLC screw [NSC]). The prosthetic screws were tightened at 32 Ncm and retightened, and the specimens were submitted to 106 mechanical cycles (4 Hz/98 N). After cyclic loading, loosening torque was evaluated, and the final measurements were performed. Data were analyzed by two-way analysis of variance and Tukey's test (α = .005). There was statistically significance in the interaction of screw × splinting (P = .003). For the group that used titanium screws, NSTi showed smaller removal torque compared with STi. It was concluded that the use of the DLC coating screws in nonsplinted prosthesis maintain the torque after cyclic loading.

Oxygen Reduction on Ag(100) in Alkaline Solutions--A Theoretical Study.

Silver is much more reactive to oxygen than gold; nevertheless, in alkaline solutions, the rates of oxygen reduction on both metals are similar. To explain this phenomenon, the first, rate-determining step of oxygen reduction on Ag(100) is determined by a combination of DFT, molecular dynamics, and electrocatalysis theory. In vacuum, oxygen is adsorbed on Ag(100), but in the electrochemical environment, the adsorption energy is offset by the loss of hydration energy as the molecule approaches the surface. As a result, the first electron transfer should take place in an outer-sphere mode. Previously, the same mechanism for oxygen reduction on Au(100) has been predicted, and these calculations have been repeated by using a more advanced version of the electrocatalysis theory discussed herein to confirm previous conclusions. The theoretical results compare well with experimental data.

Electrochemical adsorption of OH on Pt(111) in alkaline solutions: combining DFT and molecular dynamics.

The adsorption of OH on Pt(111) in alkaline solution has been investigated by a method that combines density functional theory, molecular dynamics, and quantum statistical mechanics. In particular, we have calculated the free energy surface for the reaction. A physisorbed hydroxide ion in a metastable state and a stable adsorbed uncharged OH group are observed. The energy of activation at equilibrium is comparatively low, so that the reaction is fast.

On the electrochemical deposition and dissolution of divalent metal ions.

The deposition of Cu(2+) and Zn(2+) from aqueous solution has been investigated by a combination of classical molecular dynamics, density functional theory, and a theory developed by the authors. For both cases, the reaction proceeds through two one-electron steps. The monovalent ions can get close to the electrode surface without losing hydration energy, while the divalent ions, which have a stronger solvation sheath, cannot. The 4s orbital of Cu interacts strongly with the sp band and more weakly with the d band of the copper surface, while the Zn 4s orbital couples only to the sp band of Zn. At the equilibrium potential for the overall reaction, the energy of the intermediate Cu(+) ion is only a little higher than that of the divalent ion, so that the first electron transfer can occur in an outer-sphere mode. In contrast, the energy of the Zn(+) ion lies too high for a simple outer-sphere reaction to be favorable; in accord with experimental data this suggests that this step is affected by anions.