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Induced abortion is one of the most common gynecological procedures in the world, with as many as three in every ten pregnancies ending in abortion. It, however, remains controversial. The objective of this scoping review was to explore and map existing literature on the experiences of those who provide abortion care. This exploratory review followed the Levac et al. guidelines and was reported in accordance with the PRISMA-ScR checklist. CINAHL, Cochrane, EMBASE, PsycInfo, PubMed, and Web of Science were used to identify peer-reviewed, original research articles published on providers' experience of abortion. We identified 106 relevant studies, which include a total sample of 4,250 providers from 28 countries and six continents. Most of the studies were qualitative (n = 83), though quantitative (n = 15) and mixed methods (n = 8) studies were also included. We identified two overarching themes: (1) Providers' experiences with abortion stigma and (2) Providers' reflections on their abortion work. Our findings suggest that providers from around the world experience challenges within society and their communities and workplaces which reinforce the stigmatization and marginalization of abortion and pose questions about the morality of this work. Most, however, are proud of their work, believe abortion care to be socially important and necessary, and remain committed to the provision of care. The findings of this review provide a comprehensive overview on the known experiences of providing abortion care. It is a key point of reference for international providers, researchers, and advocates to further this area of research or discussion in their own territories. The findings of this review will inform future work on how to support providers against stigmatization and will offer providers the chance to reflect on their own experiences.

Many recent studies have shown that the Reactivity Controlled Compression Ignition (RCCI) combustion strategy can achieve high efficiency with low emissions. However, it has also been revealed that RCCI combustion is difficult at high loads due to its premixed nature. To operate at moderate to high loads with gasoline/diesel dual fuel, high amounts of EGR or an ultra low compression ratio have shown to be required. Considering that both of these approaches inherently lower thermodynamic efficiency, in this study natural gas was utilized as a replacement for gasoline as the low-reactivity fuel. Due to the lower reactivity (i.e., higher octane number) of natural gas compared to gasoline, it was hypothesized to be a better fuel for RCCI combustion, in which a large reactivity gradient between the two fuels is beneficial in controlling the maximum pressure rise rate. The multi-dimensional CFD code, KIVA3V, was used in conjunction with the CHEMKIN chemistry tool and a Nondominated Sorting Genetic Algorithm (NSGA-II) to perform optimization for a wide range of engine operating conditions. Engine design parameters that were controlled by the genetic algorithm include the fraction of total fuel that is premixed (methane), the timing of the two diesel injections, the amount of diesel in each injection, the diesel fuel injection pressure, and the EGR percentage. The objective of the optimization was to simultaneously minimize soot, NOx, CO, and UHC emissions, as well as ISFC and ringing intensity. A broad load/speed range was investigated; six operating points from 4 to 23 bar IMEP and 800 to 1800 rev/min were optimized. These load/speed combinations represent typical heavy-duty engine conditions. Using the stock compression ratio of 16.1, it was determined that operation up to 13.5 bar IMEP could be achieved with no EGR, while still maintaining high efficiency and low emissions. The study also examined the sensitivity of RCCI combustion at high load to injection system parameters. The results emphasize that precise injection control is needed for combustion control.

Background Long COVID (LC) occurs when COVID-19 symptoms continue for 12 + weeks after the onset of infection. LC may have several impacts, including sickness absence. This study explored number of days off work due to COVID-19 infection among healthcare workers (HCWs) and predictors of long-term sickness absence (i.e., 4 + consecutive weeks off work). Methods Data were from the NHS CHECK survey and included 4,721 HCWs (19.6% of the cohort) who reported COVID-19-related symptoms and sickness absence at two follow-up periods, approximately 12 and 32 months post-baseline (baseline collected between April 2020 and January 2021). We conducted descriptive analysis to explore COVID-19-related sickness absence at both timepoints and to examine differences depending on whether HCWs self-reported symptoms consistent with LC or an LC diagnosis. We used multi-level logistic regression modelling to explore baseline predictors for reporting long-term sickness absence at follow-up among HCWs who reported LC symptoms. Results At 12 months, 89.5% of HCWs attributed sickness absence to a COVID-19 infection, while 84.6% reported the same at 32 months. Median self-reported days off work at both timepoints were higher among HCWs who self-reported LC symptoms (12mo = 14 days (IQR = 10–30), 32mo = 7 days (IQR = 4–14)) compared with HCWs who did not (12mo = 9.5 days (IQR = 3.5–14), 32mo = 5 days (IQR = 2–7)). A similar finding was observed for HCWs who reported a formal diagnosis of LC compared with those who did not. There was a noticeable reduction in COVID-19-related sickness absence between our 12 and 32 month follow-up surveys across all groups. Among HCWs who self-reported LC symptoms, predictors for reporting long-term sickness absence at both timepoints included having a pre-existing respiratory illness and being aged 41–50 years. Conclusions We found that reporting LC symptoms or having an LC diagnosis were associated with greater sickness absence among HCWs. The cause of the reduction in reported sickness absence between the timepoints is unclear, though it is most likely due to natural recovery from COVID-19, greater support available to staff with LC or the withdrawal of a special COVID-19 sickness absence payment in 2022. The need to support workers with LC to return and remain in work is still present.

Despite being one of the most common gynecological procedures in the world, abortion care remains highly stigmatized. Internationally, providers have noted negative impacts related to their involvement in the services, and abortion care has been described as \"dirty work.\" Though much of the existing research focuses on the challenges of providing, many have also highlighted the positive aspects of working in abortion care. Despite the steadily increasing interest in this area over the past decade, however, no one has sought to systematically review the literature to date. The aim of this review is to systematically explore published studies on the experiences of abortion care providers to create a narrative review on the lived experience of providing abortion care, reflecting on what is already known and what areas require further exploration. This review will be conducted according to the framework outlined by Levac et al, which expanded on the popular Arksey and O'Malley framework. We will systematically search for peer-reviewed articles in 6 electronic databases: CINAHL, the Cochrane Library, EMBASE, PsycInfo, PubMed, and Web of Science. Following a pilot exercise, we devised a search strategy to identify relevant studies. In this protocol, we outline how citations will be assessed for eligibility and what information will be extracted from the included articles. We also highlight how this information will be combined in the review. As of December 2021, at the time of writing, we have searched for articles in the electronic databases and identified 6624 unique citations. We intend to fully assess these citations for eligibility by the end of January 2022, chart and analyze data from the eligible citations by the end of March 2022, and submit a journal article for peer review by late spring 2022. The findings of this review will provide a comprehensive overview on the known experiences of providing abortion care. We also anticipate that the findings will identify aspects of care and experiences that are not reflected in the available literature. We will disseminate the results via a publication in a peer-reviewed academic journal and by presenting the findings at conferences in the areas of abortion care, obstetrics, and midwifery. As this review is a secondary analysis of published articles, ethical approval was not required. DERR1-10.2196/35481.

The focus of the present study was to characterize the fuel reactivity of high octane number fuels (i.e., low fuel reactivity), namely gasoline, ethanol, and methanol when mixed with cetane improvers under lean, premixed combustion conditions. Two commercially available cetane improvers, 2-ethylhexyl nitrate and di-tert-butyl peroxide, were used in the study. First, blends of the primary reference fuels iso-octane and n-heptane were port injected under fixed operating conditions. The resulting combustion phasings were used to generate effective PRF number maps. Then, blends of the aforementioned base fuels and cetane improvers were tested under the same lean premixed conditions as the PRF blends. Based on the combustion phasing results of the base fuel and cetane improver mixture, the effective PRF number, or octane number, could be determined. In all three base fuels it was found that 2-ethylhexyl nitrate is more effective at increasing fuel reactivity compared to di-tert-butyl peroxide. However, 2-ethylhexyl nitrate has a potential disadvantage due its nitrate group, which can manifest itself as NOx emissions. The relationship between the fuel-bound nitrate group and the engine-out NOx emissions was extensively characterized in the present study. It was also observed that methanol’s response to cetane improvers was better than that of ethanol, in spite of the fact that they have similar octane numbers in their neat form. Once the reactivity of the base fuels was characterized, two mixtures of methanol and cetane improvers were selected and compared to diesel fuel as the high reactivity fuel (i.e., direct injected) for RCCI combustion.

The focus of the present study was to characterize Reactivity Controlled Compression Ignition (RCCI) using a single-fuel approach of gasoline and gasoline mixed with a commercially available cetane improver on a multi-cylinder engine. RCCI was achieved by port-injecting a certification grade 96 research octane gasoline and direct-injecting the same gasoline mixed with various levels of a cetane improver, 2-ethylhexyl nitrate (EHN). The EHN volume percentages investigated in the direct-injected fuel were 10, 5, and 2.5%. The combustion phasing controllability and emissions of the different fueling combinations were characterized at 2300 rpm and 4.2 bar brake mean effective pressure over a variety of parametric investigations including direct injection timing, premixed gasoline percentage, and intake temperature. Comparisons were made to gasoline/diesel RCCI operation on the same engine platform at nominally the same operating condition. The experiments were conducted on a modern four cylinder light-duty diesel engine that was modified with a port-fuel injection system while maintaining the stock direct injection fuel system. The pistons were modified for highly premixed operation and feature an open shallow bowl design. The results indicate that the authority to control the combustion phasing through the fuel delivery strategy (e.g., direct injection timing or premixed gasoline percentage) is not a strong function of the EHN concentration in the direct-injected fuel. It was also observed that NOx emissions are a strong function of the global EHN concentration in-cylinder and the combustion phasing. In general, NOx emissions are significantly elevated for gasoline/gasoline+EHN operation compared with gasoline/diesel RCCI operation at a given operating condition.

A single-cylinder light-duty diesel engine was used to investigate dual fuel reactivity controlled compression ignition (RCCI) operated with two different fuel combinations: gasoline/diesel fuel and methanol/diesel fuel. The engine was operated over a range of conditions, from 1500 to 2300 rpm and 3.5 to 17 bar gross IMEP. Using the stock re-entrant piston bowl geometry, both fuel combinations were able to achieve low NOx and PM emissions with a peak gross indicated efficiency of 48%. However, at light load conditions both gasoline and methanol yielded poorer combustion efficiencies. Previous studies have shown that the high-levels of piston induced mixing that are created by the stock piston are not required, and in fact are detrimental due to increased heat transfer losses, for premixed combustion. Thus a modified piston featuring a shallow, flat piston bowl with nearly no squish land was also investigated. Using the modified piston, the gross indicated efficiency of RCCI combustion was significantly improved at light loads due to increases in combustion efficiency and decreases in heat transfer losses. At higher loads the modified piston also performed better than the stock piston, but the improvements were not as significant. Over the entire load and speed range, the modified piston yielded low NOx and PM emissions with a peak gross indicated efficiency of nearly 51%.

A novel exhaust-runner soot diagnostics has been developed and tested in a skip-fired diesel optical engine. Crank-angle-resolved soot emissions are measured during the cylinder blowdown and exhaust processes by multi-pass extinction of coherent, visible (635 nm) light as it passes through an optical exhaust runner. To evaluate diagnostic accuracy, comparisons are made of soot volume fraction measured by extinction in the optical exhaust runner and by a conventional smoke meter. The diagnostic exhibits excellent sensitivity with soot volume fraction detection limits of better than 0.2 parts per billion (ppb). The experiments also employed an engine exhaust particle sizer (EEPS) to characterize particle size distributions from the skip-fired optical engine. The diagnostic has been employed in this work to assess skip-fired cycle variations in soot emissions for two- and six-hole production diesel fuel injectors as oxygen concentration (i.e., dilution) is varied. As oxygen concentration is reduced for the two-hole tip, both mean soot volume fraction and cycle variations increase, with the coefficient of variation (COV) of extinction as high as 46%. At low intake oxygen (O₂) concentrations, soot apparently leaves the cylinder relatively early in the exhaust process. As O₂ concentration increases and soot volume fraction declines, smaller soot particles (as measured by the EEPS) leave the cylinder later in the exhaust stroke. Trends for the six-hole injector are similar, but cycle variations are significantly lower. The reduction in the cyclic variation of soot volume fraction as the number of orifices increases from two to six provides evidence that soot formed in a burning jet is a relatively stochastic event for which the COV is inversely proportional to the square of the number of distinct combustion plumes. The persistence of 27% exhaust soot COV for the six-hole tip at 14% intake O2 suggests that improved control and optimization of the spray formation and combustion event could significantly reduce the average engine-out PM emissions.

The potential of low temperature combustion to yield low NOx and soot while maintaining diesel-like thermal efficiencies has been demonstrated through countless studies. Methods of achieving low temperature combustion are just as numerous and they range from using high cetane number fuels, like diesel, with large amounts of exhaust gas recirculation, to completely premixing a high octane number fuel, like gasoline, and approaching an HCCI-like condition. The potential of operating a heavy-duty compression ignition engine fueled with conventional gasoline in a partially premixed combustion mode to have high thermal efficiency and low emissions has been demonstrated in this study. The objective of this work was to optimize the engine using computational tools. The KIVA3V-CHEMKIN code, a multi-dimensional engine CFD model was coupled to a Nondominated Sorting Genetic Algorithm (NSGA II), which is a multi-objective genetic algorithm. Two engine operating conditions were investigated in this study, a mid-load and a high-load point, 11 bar and 21 bar IMEP, respectively. The goal of the optimization study was to simultaneously reduce six objectives, which are soot, NOx, unburned hydrocarbons, carbon monoxide, indicated specific fuel consumption, and ringing intensity, which is related to maximum pressure rise rate. The genetic algorithm was allowed to vary eight engine design parameters that included pilot injection parameters, main injection parameters, injector included angle, number of injector nozzle holes, and swirl ratio. A non-parametric regression analysis tool was used to post-process the optimization results in order to illustrate the effects of the design parameters on the objectives. The results show that gross indicated thermal efficiencies of 50% with low emissions and low ringing intensity are possible at the mid-load condition. The high-load condition yields low NOx emissions, and an efficiency of 50% as well, but indicates that meeting soot emissions and ringing intensity constraints will be a challenge.

The authors have combined corrosion of steel fittings or perforated sheets with granular activated carbon (GAC) that had been pre-treated with Fe(III)-citrate, to produce an innovative and low-maintenance technique for removing arsenic from groundwater. Removal of arsenic was measured using two GAC column configurations: rapid small scale column tests (RSSCT's) and mini-column tests. Independent variables included pH, pre-corrosion procedure, and idling of the column (i.e. intentionally stopping flow for defined times in order to create reducing conditions). Use of corroded steel plus pre-treated GAC removed arsenic to below 10 μg/L for up to 248,000 bed volumes (BV) at pH 6, compared to 7,000 BVs for pre-treated GAC without pre-corroded steel. Performance was not as good at pH 6.5 or 7.5. Idling the system recovered the iron corrosion ability by reducing the passive Fe(III) layer on pre-corroded steel surface, as a result the BVs to arsenic breakthrough was doubled. But idling also caused brief periods of arsenic and iron release after restart, due to reductive dissolution of arsenic-containing ferric oxides. GAC was also effective as filtration media for removal of iron (hydr)oxide particles (and associated arsenic) that was released from the pre-corroded iron.