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Exploring possible protective factors against antenatal depression is important since antenatal depression is common and affects both mother and child. The person characteristic trait mindfulness may be such a protective factor. Because of the high variability in depressive symptoms over time, we aimed to assess the association between trait mindfulness and trajectories of depressive symptoms during pregnancy. A subsample of 762 women participating in the HAPPY study completed the Three Facet Mindfulness Questionnaire-Short Form at 22 weeks of pregnancy. Possible different trajectories of Edinburgh Postnatal Depression Scale (EPDS) scores, assessed at each pregnancy trimester, were explored with growth mixture modeling. Three EPDS trajectories (classes) were identified: low stable symptom scores (N = 607, 79.7%), decreasing symptom scores (N = 74, 9.7%) and increasing symptom scores (N = 81, 10.6%). Compared to belonging to the low stable class (reference), women with higher scores on the trait mindfulness facets 'acting with awareness' and 'non-judging' were less likely to belong to the decreasing class (OR = 0.81, 95% CI [0.73, 0.90] and OR = 0.77, 95% CI [0.70, 0.84]) and increasing class (OR = 0.88, 95% CI [0.80, 0.97] and OR = 0.72, 95% CI [0.65, 0.79]). Women with higher scores on 'non-reacting' were less likely to belong to the increasing class (OR = 0.89, 95% CI [0.82, 0.97]), but not the decreasing class (OR = 0.96, 95% CI [0.87, 1.04]). All analyses were adjusted for confounders. Characteristics of trait mindfulness predicted low stable levels of depressive symptoms throughout pregnancy. Mindfulness-based programs may be beneficial for pregnant women as a strategy to alleviate depression risks. • Growth mixture modeling was used to assess antenatal depressive symptoms. • We found a low stable (79.7%), decreasing (9.7%) and increasing (10.6%) EPDS class. • Trait mindfulness facets were associated with EPDS trajectories during pregnancy. • Characteristics of trait mindfulness predicted low stable depressive symptom levels. [ABSTRACT FROM AUTHOR]

Characteristics of diesel sprays injected through Cummins medium-duty ISB injectors were studied experimentally in an optically accessible constant-volume combustion vessel. The experiments were performed with ultra-low-sulfur diesel (ULSD) under non-reacting and non-vaporizing conditions, including different ambient gas densities (23–65 kg/m3), injection pressures (500–1,500 bar), and injection duration times (0.5–1.5 ms). The ambient temperature of the vessel was maintained at a room temperature of 313 K for all the tests. A systematic comparison was made between single-hole (SH) and multi-hole (MH) injector configurations. A plume-to-plume variation in spray penetration length was observed for various operating conditions. A substantial deviation was observed for a specific hole against the averaged plume, indicating that arbitrary selection of the plume index may result in inaccurate spray characterization of the MH injector. The penetration length of the MH injector was shorter than that of the SH injector under the same operating conditions, indicating that a spray model calibrated on SH injector data may not accurately predict the transient spray behavior of the MH injector in practical engine simulations. A square-root correlation of the spray penetration length was applied for both the SH and MH injectors. The spray penetration length and dispersion angles of the ISB SH injector were also compared with those of the heavy-duty Cummins ISX SH injector. While the ISX SH injector showed a faster penetration than the ISB SH injector, the dispersion angle was similar. The differences in spray penetration between ISB and ISX injectors followed the expected trend based on their nozzle hole diameters.

Gasoline compression ignition (GCI) is a promising combustion technology that could help alleviate the projected demand for diesel in commercial transport while providing a pathway to achieve upcoming CO2 and criteria pollutant regulations for heavy-duty engines. However, relatively high (i.e., diesel-like) injection pressures are needed to enable GCI across the entire load range while maintaining soot emissions benefits and managing heat release rates. There have only been a limited number of previous studies investigating the spray characteristics of light distillates with high-pressure direct-injection hardware under charge gas conditions relevant to heavy-duty applications. The current work aims to address this issue while providing experimental data needed for calibrating spray models used in simulation-led design activities. The non-reacting spray characteristics of two gasoline-like fuels relevant to GCI were studied and compared to ultra-low-sulfur diesel (ULSD). These fuels shared similar physical properties and were thus differentiated based on their research octane number (RON). Although RON60 and RON92 had different reactivities, it was hypothesized that they would exhibit similar non-reacting spray characteristics due to their physical similarities. Experiments were conducted in an optically accessible, constant volume combustion chamber using a single-hole injector representing high-pressure, common-rail fuel systems. Shadowgraph and Mie-scattering techniques were employed to measure the spray dispersion angles and penetration lengths under both non-vaporizing and vaporizing conditions. Gasoline-like fuels exhibited similar or larger non-vaporizing dispersion angle compared to ULSD. All fuels followed a typical correlation based on air-to-fuel density ratio indicating that liquid density is the main governing fuel parameter. Injection pressure had a negligible effect on the dispersion angle. Gasoline-like fuels had slower non-vaporizing penetration rates compared to ULSD, primarily due to their larger dispersion angles. As evidenced by the collapse of data onto a non-dimensional penetration correlation over a wide range of test conditions, all fuels conformed to the expected physical theory governing non-vaporizing sprays. There was no significant trend in the vaporizing dispersion angle with respect to fuel type which remained relatively constant across the entire charge gas temperature range of 800–1200 K. There was also no discernable difference in vapor penetration among the fuels or across charge temperature. The liquid length of gasoline-like fuels was much shorter than ULSD and exhibited no dependence on charge temperature at a given charge gas pressure. This behavior was attributed to gasoline being limited by interphase transport as opposed to mixing or air entrainment rates during its evaporation process. RON92 had a larger non-vaporizing dispersion angle but similar penetration compared to RON60. Although this seems to violate the original similarity hypothesis for these fuels, the analysis was made difficult due to the use of different injector builds for the experiments. However, RON92 did show a slightly larger vapor dispersion angle than RON60 and ULSD. This observation was attributed to nuanced volatility differences between the gasoline-like fuels and indicates that vapor dispersion angle likely relies on a more complex correlation beyond that of only air-to-fuel density ratio. Finally, RON92 showed the same quantitative liquid length and insensitivity to charge gas temperature as RON60.

Blending of fossil fuels with alcohols is one of the most impressive strategies for emission control and enhancement of fuel efficiency. Accordingly, in the current paper, the effects of blend of Heavy Fuel Oil (HFO) with bioalcohols are numerically studied on the non-reacting spray characteristics. Three different fuels are considered by mixture of HFO with 20% of n-Butanol, Ethanol, and Methanol and compared against Pure HFO. For this purpose, the microscopic and macroscopic spray characteristics of the blended fuels are evaluated through the investigation of spray penetration, cone angle, spray volume, and Sauter Mean Diameter (SMD). Moreover, for detailed understanding of the spray characteristics, the non-dimensional numbers of Weber and Ohnesorge, and liquid spray morphology are analyzed. Also, the study of Histogram of density and droplet diameter is conducted. Eulerian-Lagrangian multiphase scheme is used for simulation of air-fuel interaction in OpenFOAM CFD toolbox. Lagrangian Particle Tracking method is utilized for fuel droplet tracking in Lagrangian scheme. A hybrid breakup model of KH-RT and standard model of k-ε in RANS is used respectively for breakup and turbulence modeling. The obtained numerical results are validated against existing experimental data with suitable accordance. Based on the computational results, longer spray penetration length, larger spray cone angle and greater spray volume are achieved for the blended fuels. It was also concluded that HFO-Ethanol improves the macroscopic characteristics compared to two other blended fuels, albeit the effect is very minimal. In addition, lower SMD value is obtained for the blended fuels compared to pure HFO.

The WHO recommends breastfeeding for at least six months as breastfeeding has many benefits for both infant and mother. The association of breastfeeding continuation with trait mindfulness during pregnancy and trajectories of postpartum depressive symptoms has not been examined yet. The current study aimed to assess this association using cox regression analysis. The current research is part of a large longitudinal prospective cohort study following women from 12 weeks of pregnancy onwards in the South-East part of the Netherlands. A total of 698 participants filled out the Three Facet Mindfulness Questionnaire-Short Form (TFMQ-SF) at 22 weeks of pregnancy and completed both the Edinburgh Postnatal Depression Scale (EPDS) and questions on breastfeeding continuation one week, six weeks, four months, and eight months postpartum. Breastfeeding continuation was defined as exclusive breastfeeding or both breastfeeding and formula. The assessment eight months postpartum was used as a proxy for the WHO recommendation to continue breastfeeding for at least six months. Two trajectories (classes) of EPDS scores were determined using growth mixture modeling: 1) low stable (N = 631, 90.4%), and 2) increasing (N = 67, 9.6%). Cox regression analysis showed that the trait mindfulness facet non-reacting was significantly and inversely associated with the risk of breastfeeding discontinuation (HR = 0.96, 95% CI [0.94, 0.99], p =.002), while no significant association was found for belonging to the increasing EPDS class versus belonging to the low stable class (p =.735), adjusted for confounders. This study is the first to show that higher trait mindfulness non-reacting scores, but not persistently low levels of postpartum depressive symptoms, increase the likelihood of breastfeeding continuation. Improving non-reacting in perinatal women by meditation practice as part of a mindfulness-based intervention may lead to better breastfeeding continuation outcomes. Several mindfulness-based programs may be suitable. [ABSTRACT FROM AUTHOR]

A uniform dispersion of reactants is necessary to achieve a complete reaction involving multiple components. Utilizing a combination of infrared spectroscopy, thermal analysis and low field NMR, we have elucidated the role of three types of reactive plasticizers on the crosslinking reaction between hexamethylenetetramine and phenol formaldehyde resin. These two seemingly dissimilar reactants are responsible for the exceptionally high mechanical strength in a number of organic-inorganic composites. The efficiencies of the curing reaction and the achieved crosslinked structures are strongly dependent on the type of plasticizer employed. Infrared active vibrations are used to characterize the changing molecular structures of the individual reactants as a function of temperature. The T 1 spin-lattice relaxation time measured using low field NMR is especially useful for the characterization of segmental dynamics of the chains in the formation of the extremely rigid crosslinked product. This study shows that the amount of crosslinking and the crosslinked structure can be very different for the three types of reactive plasticizers and also different in comparison to non-reactive plasticizers. We are also able to correlate the reactivity and functionality of the plasticizer to the crosslink density in the reacted product. [ABSTRACT FROM AUTHOR]

Blending of fossil fuels with alcohols is one of the most impressive strategies for emission control and enhancement of fuel efficiency. Accordingly, in the current paper, the effects of blend of Heavy Fuel Oil (HFO) with bioalcohols are numerically studied on the non-reacting spray characteristics. Three different fuels are considered by mixture of HFO with 20% of n-Butanol, Ethanol, and Methanol and compared against Pure HFO. For this purpose, the microscopic and macroscopic spray characteristics of the blended fuels are evaluated through the investigation of spray penetration, cone angle, spray volume, and Sauter Mean Diameter (SMD). Moreover, for detailed understanding of the spray characteristics, the non-dimensional numbers of Weber and Ohnesorge, and liquid spray morphology are analyzed. Also, the study of Histogram of density and droplet diameter is conducted. Eulerian-Lagrangian multiphase scheme is used for simulation of air-fuel interaction in OpenFOAM CFD toolbox. Lagrangian Particle Tracking method is utilized for fuel droplet tracking in Lagrangian scheme. A hybrid breakup model of KH-RT and standard model of k-e in RANS is used respectively for breakup and turbulence modeling. The obtained numerical results are validated against existing experimental data with suitable accordance. Based on the computational results, longer spray penetration length, larger spray cone angle and greater spray volume are achieved for the blended fuels. It was also concluded that HFO-Ethanol improves the macroscopic characteristics compared to two other blended fuels, albeit the effect is very minimal. In addition, lower SMD value is obtained for the blended fuels compared to pure HFO. [ABSTRACT FROM AUTHOR]

The cold spray and spray combustion characteristics of palm biodiesel were investigated and compared with baseline Jet-A1 fuel. Both fuel sprays were generated from an airblast type atomizer and compared under the same atomizing air-to-liquid mass ratio (ALR). Under non-reacting spray condition, droplet velocity profiles for both sprays peak at the centerline due to high atomizing air momentum, while the droplet size is smallest at the spray core. Palm biodiesel generated slightly larger droplet size compared to Jet-A1 due to the effect of higher viscosity and lower volatility. Utilising an airblast atomizer-based swirl burner, spray flames of Jet-A1 and palm biodiesel were established and compared under continuous, steady swirl conditions. The droplet velocity and diameter distributions within the reacting spray flames were significantly different compared to non-reacting spray due to interaction with swirl air flow and flame within the combustor. Spray flame reaction zones obtained via OH* chemiluminescence imaging showed that fuel droplets evaporated rapidly within 20 mm from the burner outlet. Reacting Jet-A1 flame showed smaller droplet size compared to biodiesel due to higher vaporisation rate and close proximity to flame reaction zone. Palm biodiesel showed consistently lower NO x but slightly higher CO emissions per unit energy compared to Jet-A1 under a range of ALR tested. [ABSTRACT FROM AUTHOR]

This article investigates the application of the large eddy simulation (LES) technique to turbulent isothermal swirling flows. The aim was to improve our understanding of the flow physics and turbulence structure of unconfined swirling flows and examine the capability of LES to predict the formation of the vortex breakdown (VB) and recirculation zones. In this study, the filtered Navier-Stokes equations are closed using the Smagorinsky eddy viscosity model with the localized dynamic procedure of Piomelli and Liu (1995). The Sydney University swirl burner experiments are simulated as test cases. Three different test cases have been investigated covering a range of swirl numbers and stream wise annular velocities. The cases considered have swirl numbers ranging from 0 to 1.59 and Reynolds numbers from 32400 to 59000. The LES calculations confirm that the combination of lower swirl number and higher axial velocity of the primary annulus leads to the establishment of the downstream vortex breakdown region. For the cases considered, the LES calculations were successful in predicting observed recirculation zones, vortex breakdown and showed good agreement with experimentally measured mean velocities, their rms fluctuations and Reynolds shear stresses. [ABSTRACT FROM AUTHOR]

This paper focuses on unconfined swirling flows of air surrounding a bluff-body having a central jet of air. Only one co-flowing primary annular air stream is swirled. The flow conditions investigated here cover a range of swirl numbers and streamwise annular velocities. Emphasis is placed on discerning typical flow structures and on discovering the influence of controlling parameters on the downstream regions of the jet and the recirculation within. The paper is part of a larger program aimed at providing an improved understanding of swirling flows.Laser doppler velocimetry is used to map three components of velocity 〈u〉, 〈v〉 and 〈w〉. In the flows investigated, an upstream recirculation zone is established above the burner’s exit plane. This zone is typical of that found behind bluff-bodies placed in strong axial streams. Additionally, it is shown that the formation of a downstream recirculation zone, hence the onset of vortex breakdown, depends not only on the swirl number but on other flow parameters such as the axial velocity of the primary swirling air, or its Reynolds number. Together, these two parameters appear to control the radial spread of the flow. Spatially, the progression towards downstream recirculation with changes in flow parameters is seen to occur around a fixed location in the streamwise direction. Beyond this axial position, the flowfield seems to be less affected by increases in swirl number. Non-recirculating flow structures are resolved in these flows and are found to cause elevated 〈u′w′〉 shear stresses. [Copyright &y& Elsevier]

Breastfeeding has been associated with many health benefits for both infant and mother. Trait mindfulness during pregnancy may have a beneficial impact on breastfeeding intention. The current study aimed to examine whether trait mindfulness during pregnancy was associated with antenatal breastfeeding intention. The current study is part of a large prospective population-based cohort study among pregnant women in the south of the Netherlands. A subsample of participants completed the Three Facet Mindfulness Questionnaire-Short Form at 22 weeks of pregnancy and a question on their breastfeeding intention at 32 weeks of pregnancy (N=790). Moreover, the Edinburgh Depression Scale and Tilburg Pregnancy Distress scale were completed at 32 weeks of pregnancy to assess levels of distress. Univariate analyses showed that women with breastfeeding intention during pregnancy had significantly higher scores on the mindfulness facet non-reacting (p <.001, medium effect size) and significantly lower scores on acting with awareness (p =.035, small effect size). A subsequent multiple logistic regression analysis showed that only non-reacting remained significantly associated with antenatal breastfeeding intention (OR=1.09, 95% CI [1.03, 1.15], p =.001), after controlling for confounders. Women who eventually initiated breastfeeding had significantly higher non-reacting scores (p <.001, small to medium effect size). The mindfulness facet non-reacting was found to be associated with antenatal breastfeeding intention. More research is needed to confirm our results, since the current study is one of the first assessing the possible relation of trait mindfulness during pregnancy and breastfeeding intention. Mindfulness-based programs during pregnancy could be helpful in improving non-reacting in pregnant women, which may enhance breastfeeding intention and ultimately the initiation of breastfeeding. [ABSTRACT FROM AUTHOR]