Coalescence dynamics of a hollow droplet falling in a liquid pool

The partial coalescence dynamics of a hollow droplet in a liquid pool is numerically investigated. We study the effect of the ratio of the inner to outer radii (Rr) of the hollow droplet while maintaining a constant volume. It is observed that for small values of the radius ratio, the coalescence dynamics is similar to that of a ‘filled’ droplet, but the partial coalescence is suppressed for large values of Rr. Increasing the value of increases the distance migrated by the inner bubble in the downward direction inside the pool away from the free surface. The location of the bubble after coalescence is found to play an important role in the pinch-off process of the satellite droplet. The influence of the governing dimensionless parameters on the coalescence dynamics has also been investigated

Socio-spatial equity analysis of relative wealth index and emergency obstetric care accessibility in urban Nigeria

Background: Better geographical accessibility to comprehensive emergency obstetric care (CEmOC) facilities can significantly improve pregnancy outcomes. However, with other factors, such as affordability critical for care access, it is important to explore accessibility across groups. We assessed CEmOC geographical accessibility by wealth status in the 15 most-populated Nigerian cities. Methods: We mapped city boundaries, verified and geocoded functional CEmOC facilities, and assembled population distribution for women of childbearing age and Meta’s Relative Wealth Index (RWI). We used the Google Maps Platform’s internal Directions Application Programming Interface to obtain driving times to public and private facilities. City-level median travel time (MTT) and number of CEmOC facilities reachable within 60 min were summarised for peak and non-peak hours per wealth quintile. The correlation between RWI and MTT to the nearest public CEmOC was calculated. Results: We show that MTT to the nearest public CEmOC facility is lowest in the wealthiest 20% in all cities, with the largest difference in MTT between the wealthiest 20% and least wealthy 20% seen in Onitsha (26 vs 81 min) and the smallest in Warri (20 vs 30 min). Similarly, the average number of public CEmOC facilities reachable within 60 min varies (11 among the wealthiest 20% and six among the least wealthy in Kano). In five cities, zero facilities are reachable under 60 min for the least wealthy 20%. Those who live in the suburbs particularly have poor accessibility to CEmOC facilities. Conclusions: Our findings show that the least wealthy mostly have poor accessibility to care. Interventions addressing CEmOC geographical accessibility targeting poor people are needed to address inequities in urban settings

A geospatial database of close-to-reality travel times to obstetric emergency care in 15 Nigerian conurbations

Travel time estimation accounting for on-the-ground realities between the location where a need for emergency obstetric care (EmOC) arises and the health facility capable of providing EmOC is essential for improving pregnancy outcomes. Current understanding of travel time to care is inadequate in many urban areas of Africa, where short distances obscure long travel times and travel times can vary by time of day and road conditions. Here, we describe a database of travel times to comprehensive EmOC facilities in the 15 most populated extended urban areas of Nigeria. The travel times from cells of approximately 0.6 × 0.6 km to facilities were derived from Google Maps Platform’s internal Directions Application Programming Interface, which incorporates traffic considerations to provide closer-to-reality travel time estimates. Computations were done to the first, second and third nearest public or private facilities. Travel time for eight traffic scenarios (including peak and non-peak periods) and number of facilities within specific time thresholds were estimated. The database offers a plethora of opportunities for research and planning towards improving EmOC accessibility

A geospatial database of close-to-reality travel times to obstetric emergency care in 15 Nigerian conurbations

Travel time estimation accounting for on-the-ground realities between the location where a need for emergency obstetric care (EmOC) arises and the health facility capable of providing EmOC is essential for improving pregnancy outcomes. Current understanding of travel time to care is inadequate in many urban areas of Africa, where short distances obscure long travel times and travel times can vary by time of day and road conditions. Here, we describe a database of travel times to comprehensive EmOC facilities in the 15 most populated extended urban areas of Nigeria. The travel times from cells of approximately 0.6 × 0.6 km to facilities were derived from Google Maps Platform’s internal Directions Application Programming Interface, which incorporates traffic considerations to provide closer-to-reality travel time estimates. Computations were done to the first, second and third nearest public or private facilities. Travel time for eight traffic scenarios (including peak and non-peak periods) and number of facilities within specific time thresholds were estimated. The database offers a plethora of opportunities for research and planning towards improving EmOC accessibility

Socio-spatial equity analysis of relative wealth index and emergency obstetric care accessibility in urban Nigeria

Background. Better geographical accessibility to comprehensive emergency obstetric care (CEmOC) facilities can significantly improve pregnancy outcomes. However, with other factors, such as affordability critical for care access, it is important to explore accessibility across groups. We assessed CEmOC geographical accessibility by wealth status in the 15 most-populated Nigerian cities. Methods. We mapped city boundaries, verified and geocoded functional CEmOC facilities, and assembled population distribution for women of childbearing age and Meta’s Relative Wealth Index (RWI). We used the Google Maps Platform’s internal Directions Application Programming Interface to obtain driving times to public and private facilities. City-level median travel time (MTT) and number of CEmOC facilities reachable within 60min were summarised for peak and non-peak hours per wealth quintile. The correlation between RWI and MTT to the nearest public CEmOC was calculated. Results We show that MTT to the nearest public CEmOC facility is lowest in the wealthiest 20%in all cities, with the largest difference in MTT between the wealthiest 20% and least wealthy 20% seen in Onitsha (26 vs 81min) and the smallest in Warri(20vs30min). Similarly, the average number of public CEmOC facilities reachable within 60min varies (11 among the wealthiest 20% and six among the least wealthy in Kano). In five cities, zero facilities are reachable under 60min for the least wealthy 20%. Those who live in the suburbs particularly have poor accessibility to CEmOC facilities. Conclusions. Our findings show that the least wealthy mostly have poor accessibility to care. Interventions addressing CEmOC geographical accessibility targeting poor people are needed to address inequities in urban settings

Geographical accessibility to functional emergency obstetric care facilities in urban Nigeria using closer-to-reality travel time estimates: a population-based spatial analysis

Better accessibility for emergency obstetric care facilities can substantially reduce maternal and perinatal deaths. However, pregnant women and girls living in urban settings face additional complex challenges travelling to facilities. We aimed to assess the geographical accessibility of the three nearest functional public and private comprehensive emergency obstetric care facilities in the 15 largest Nigerian cities via a novel approach that uses closer-to-reality travel time estimates than traditional model-based approaches. In this population-based spatial analysis, we mapped city boundaries, verified and geocoded functional comprehensive emergency obstetric care facilities, and mapped the population distribution for girls and women aged 15–49 years (ie, of childbearing age). We used the Google Maps Platform's internal Directions Application Programming Interface to derive driving times to public and private facilities. Median travel time and the percentage of women aged 15–49 years able to reach care were summarised for eight traffic scenarios (peak and non-peak hours on weekdays and weekends) by city and within city under different travel time thresholds (≤15 min, ≤30 min, ≤60 min). Findings As of 2022, there were 11·5 million girls and women aged 15–49 years living in the 15 studied cities, and we identified the location and functionality of 2020 comprehensive emergency obstetric care facilities. City-level median travel time to the nearest comprehensive emergency obstetric care facility ranged from 18 min in Maiduguri to 46 min in Kaduna. Median travel time varied by location within a city. The between-ward IQR of median travel time to the nearest public comprehensive emergency obstetric care varied from the narrowest in Maiduguri (10 min) to the widest in Benin City (41 min). Informal settlements and peripheral areas tended to be worse off compared to the inner city. The percentages of girls and women aged 15–49 years within 60 min of their nearest public comprehensive emergency obstetric care ranged from 83% in Aba to 100% in Maiduguri, while the percentage within 30 min ranged from 33% in Aba to over 95% in Ilorin and Maiduguri. During peak traffic times, the median number of public comprehensive emergency obstetric care facilities reachable by women aged 15–49 years under 30 min was zero in eight (53%) of 15 cities. Interpretation Better access to comprehensive emergency obstetric care is needed in Nigerian cities and solutions need to be tailored to context. The innovative approach used in this study provides more context-specific, finer, and policy-relevant evidence to support targeted efforts aimed at improving comprehensive emergency obstetric care geographical accessibility in urban Africa

Geographical accessibility to functional emergency obstetric care facilities in urban Nigeria using closer-to-reality travel time estimates: a population-based spatial analysis.

BACKGROUND: Better accessibility for emergency obstetric care facilities can substantially reduce maternal and perinatal deaths. However, pregnant women and girls living in urban settings face additional complex challenges travelling to facilities. We aimed to assess the geographical accessibility of the three nearest functional public and private comprehensive emergency obstetric care facilities in the 15 largest Nigerian cities via a novel approach that uses closer-to-reality travel time estimates than traditional model-based approaches. METHODS: In this population-based spatial analysis, we mapped city boundaries, verified and geocoded functional comprehensive emergency obstetric care facilities, and mapped the population distribution for girls and women aged 15-49 years (ie, of childbearing age). We used the Google Maps Platform's internal Directions Application Programming Interface to derive driving times to public and private facilities. Median travel time and the percentage of women aged 15-49 years able to reach care were summarised for eight traffic scenarios (peak and non-peak hours on weekdays and weekends) by city and within city under different travel time thresholds (≤15 min, ≤30 min, ≤60 min). FINDINGS: As of 2022, there were 11·5 million girls and women aged 15-49 years living in the 15 studied cities, and we identified the location and functionality of 2020 comprehensive emergency obstetric care facilities. City-level median travel time to the nearest comprehensive emergency obstetric care facility ranged from 18 min in Maiduguri to 46 min in Kaduna. Median travel time varied by location within a city. The between-ward IQR of median travel time to the nearest public comprehensive emergency obstetric care varied from the narrowest in Maiduguri (10 min) to the widest in Benin City (41 min). Informal settlements and peripheral areas tended to be worse off compared to the inner city. The percentages of girls and women aged 15-49 years within 60 min of their nearest public comprehensive emergency obstetric care ranged from 83% in Aba to 100% in Maiduguri, while the percentage within 30 min ranged from 33% in Aba to over 95% in Ilorin and Maiduguri. During peak traffic times, the median number of public comprehensive emergency obstetric care facilities reachable by women aged 15-49 years under 30 min was zero in eight (53%) of 15 cities. INTERPRETATION: Better access to comprehensive emergency obstetric care is needed in Nigerian cities and solutions need to be tailored to context. The innovative approach used in this study provides more context-specific, finer, and policy-relevant evidence to support targeted efforts aimed at improving comprehensive emergency obstetric care geographical accessibility in urban Africa. FUNDING: Google

Enhancing Inputs Use Efficiency through Resource Conservation Technologies: Empirical Evidences from Different Agro Climatic Zones of Uttar Pradesh

Resource conservation technologies (RCTs) are one of the improved practices for crop production, which enhance input use efficiency and reduce the negative consequences of crop production. Out of several options of RCTs, farmers mainly adopt and use zero/reduced tillage and rotavator for land preparation and sowing of wheat crop. The present study is based on primary data and it was collected from eight agro-climatic zones of Uttar Pradesh by using snowball method. Results suggest that, average cost of cultivation of wheat crop was lower and gross and net return from wheat was higher in case of RCTs adopters as compared to non-adopters. The economic benefits due to adoption of RCTs were higher in all the agro-climatic zones of Uttar Pradesh. After adoption of RCTs, diesel consumption, carbon emission and irrigation water use substantially reduced in the study area. The agronomic and net economic water productivity was higher for RCTs adopters as compared to non-adopters. The study further suggests that if farmers of eight agro-climatic zones of Uttar Pradesh allocate 25 per cent their wheat irrigated area under both technologies, the incremental wheat yield benefit and irrigation water saving would be the tune of 12.74 million quintal and 1011.09 MCM, respectively. Furthermore, if farmers of eight agro-climatic zones of Uttar Pradesh allocate 50 per cent their wheat irrigated area in future under both technologies an incremental wheat yield benefit would be 25.47 million quintals and irrigation water saving would be 2022.19 MCM. The allocation of 50 per cent of wheat irrigated area under both the technologies is quite possible after elimination of certain constraints in adoption of RCTs in the study area. The major constraints associated with the adoption of technologies are high cost of machines and non-availability of machines in time and at lower hiring charges. For the adoption of both technologies on large scale, government should provide more subsidies on the purchase of zero-tillage and rotavator machines because the cost of these machines are very high and farmers are unable to purchase them because of poor economic conditions in the study area. It will also help to reduce the hiring cost and availability of machines in time due to increase in number of machines in the study area

Enhancing Inputs Use Efficiency through Resource Conservation Technologies: Empirical Evidences from Different Agro Climatic Zones of Uttar Pradesh

Resource conservation technologies (RCTs) are one of the improved practices for crop production, which enhance input use efficiency and reduce the negative consequences of crop production. Out of several options of RCTs, farmers mainly adopt and use zero/reduced tillage and rotavator for land preparation and sowing of wheat crop. The present study is based on primary data and it was collected from eight agro-climatic zones of Uttar Pradesh by using snowball method. Results suggest that, average cost of cultivation of wheat crop was lower and gross and net return from wheat was higher in case of RCTs adopters as compared to non-adopters. The economic benefits due to adoption of RCTs were higher in all the agro-climatic zones of Uttar Pradesh. After adoption of RCTs, diesel consumption, carbon emission and irrigation water use substantially reduced in the study area. The agronomic and net economic water productivity was higher for RCTs adopters as compared to non-adopters. The study further suggests that if farmers of eight agro-climatic zones of Uttar Pradesh allocate 25 per cent their wheat irrigated area under both technologies, the incremental wheat yield benefit and irrigation water saving would be the tune of 12.74 million quintal and 1011.09 MCM, respectively. Furthermore, if farmers of eight agro-climatic zones of Uttar Pradesh allocate 50 per cent their wheat irrigated area in future under both technologies an incremental wheat yield benefit would be 25.47 million quintals and irrigation water saving would be 2022.19 MCM. The allocation of 50 per cent of wheat irrigated area under both the technologies is quite possible after elimination of certain constraints in adoption of RCTs in the study area. The major constraints associated with the adoption of technologies are high cost of machines and non-availability of machines in time and at lower hiring charges. For the adoption of both technologies on large scale, government should provide more subsidies on the purchase of zero-tillage and rotavator machines because the cost of these machines are very high and farmers are unable to purchase them because of poor economic conditions in the study area. It will also help to reduce the hiring cost and availability of machines in time due to increase in number of machines in the study area

Bond efficacy of recycled orthodontic brackets: A comparative in vitro evaluation of two methods

Context: Recycling of orthodontic brackets in developing orthodontic economies is an extremely common procedure. Bonding protocols and reliability of these brackets is, however, questionable, and still the subject of research. Aims: The aim was to evaluate and compare the shear bond strength of brackets recycled with sandblasting and silicoating. Materials and Methods: Ninety extracted human premolars were bonded with 0.022” SS brackets (American Orthodontics, Sheboygan USA) and then debonded. The debonded brackets were divided into three groups of 30 each. Group I: Sandblasting with 50-μm aluminum oxide (control group) Group II: Sandblasting with 50-μm aluminum oxide followed by metal primer application Group III: Silicoating with 30-μm Cojet sand followed by silane application and rebonded with Transbond XT. The sandblasted brackets and silicoated brackets were viewed under the scanning electron microscope, immediately after surface conditioning before rebonding. The shear bond strength with each group was tested. Statistical Analysis Used: One-way analysis of variance, post-hoc Scheffe multiple comparison tests. Results: The results showed that sandblasting created more irregularities and deeper erosions while silica coating created superficial irregularities and shallow erosions