Browsing by Author "Aziz, Khalid"

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    A Mathematical model for the prediction of wellbore heat loss and pressure drop in steam injection wells
    (1980) Fontanilla, Jerry P.; Aziz, Khalid
    Steam drive project design requires the condition of steam at the sandface before it enters the formation to obtain the recoverable oil as a result of this thermal oil recovery process. Several analytical wellbore heat loss models can be found in the literature, but they are made with numerous simplifying assumptions. A need for a comprehensive and rigorous model for the prediction of wellbore heat loss and pressure drop including the effects of gravity, friction, and kinetic energy for quantitative analyses therefore came into being. The mathematical model is developed by combining the continuity equation, the total energy equation, the mechanical energy equation or the extended Bernoulli equation, and the heat loss equation and reducing them to two first order differential equations in terms of the pressure gradient (dP/dz) and steam quality gradient (dx/dz). These equations are solved numerically in this thesis by the Fourth Order Runge Kutta method. The steam properties are read off directly from the steam tables obtained from Faires (1962). The pressure and steam quality at each mesh point along the injection tubing string are solved for in a step-wise manner until the depth reaches the sandface or the formation depth. An investigation of the two-phase pressure drop correlations for downward steam flow is also done. The Aziz, Govier and Fogarasi correlation, which is a correlation for upflow was modified for downflow in the bubble flow and slug flow patterns, but in the annular flow and mist flow there is no need for modification as a no slip condition is assumed. It was found that the Yamazaki and Yamaguchi correlation does not work for a steam system with liquid holdup less than 10%, as it predicts huge friction pressure drop in this range. An investigation was also conducted to see if existing correlations could be modified to improve their accuracy. It was found that Yamazaki and Yamaguchi's hydrostatic head correlation could be adjusted to match experimental data when frictional contribution is calculated with the Duns and Ros method. The limited testing done here shows that the Beggs and Brill correlation is the most reliable of all existing methods.
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    A Numerical study of natural convection in porous media
    (1968) Karra, Perayya Sastry; Aziz, Khalid
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    A Sequential solution approach for three-phase areal simulators
    (1978) Montesdeoca M., Carlos; Aziz, Khalid
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    An Experimental investigation of natural convection in porous media
    (1972) Kaneko, Takeshi; Aziz, Khalid
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    Analysis of parameters influencing steam injection rate in simulators
    (1982) Yuen, Bevan Bun Wo; Aziz, Khalid
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    Barriers for kangaroo mother care (KMC) acceptance, and practices in southern Ethiopia: a model for scaling up uptake and adherence using qualitative study
    (2021-01-07) Bilal, Selamawit M; Tadele, Henok; Abebo, Teshome A; Tadesse, Birkneh T; Muleta, Mekonnen; W/Gebriel, Fitsum; Alemayehu, Akalewold; Haji, Yusuf; Kassa, Dejene H; Astatkie, Ayalew; Asefa, Anteneh; Teshome, Million; Kawza, Aknaw; Wangoro, Shemels; Brune, Thomas; Singhal, Nalini; Worku, Bogale; Aziz, Khalid
    Abstract Background Globally, approximately 15 million babies are born preterm every year. Complications of prematurity are the leading cause of under-five mortality. There is overwhelming evidence from low, middle, and high-income countries supporting kangaroo mother care (KMC) as an effective strategy to prevent mortality in both preterm and low birth weight (LBW) babies. However, implementation and scale-up of KMC remains a challenge, especially in lowincome countries such as Ethiopia. This formative research study, part of a broader KMC implementation project in Southern Ethiopia, aimed to identify the barriers to KMC implementation and to devise a refined model to deliver KMC across the facility to community continuum. Methods A formative research study was conducted in Southern Ethiopia using a qualitative explorative approach that involved both health service providers and community members. Twenty-fourin-depth interviewsand 14 focus group discussions were carried out with 144study participants. The study applied a grounded theory approach to identify,examine, analyse and extract emerging themes, and subsequently develop a model for KMC implementation. Results Barriers to KMC practice included gaps in KMC knowledge, attitude and practices among parents of preterm and LBW babies;socioeconomic, cultural and structural factors; thecommunity’s beliefs and valueswith respect to preterm and LBW babies;health professionals’ acceptance of KMC as well as their motivation to implement practices; and shortage of supplies in health facilities. Conclusions Our study suggests a comprehensive approach with systematic interventions and support at maternal, family, community, facility and health care provider levels. We propose an implementation model that addresses this community to facility continuum.
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    Breastfeeding self-efficacy and breastmilk feeding for moderate and late preterm infants in the Family Integrated Care trial: a mixed methods protocol
    (2018-07-06) Brockway, Meredith; Benzies, Karen M; Carr, Eloise; Aziz, Khalid
    Abstract Background Breastmilk is the ideal nutrition for preterm infants. Yet, breastmilk feeding rates among preterm infants are substantially lower than those of full-term infants. Barriers incurred through hospital care practices as well as the physical environment of the neonatal intensive care unit (NICU) can result in physical and emotional separation of infants from their parents, posing a substantial risk to establishing and maintaining breastfeeding. Additionally, current practitioner-focused care provision in the NICU can result in decreased breastfeeding self-efficacy (BSE), which is predictive of breastfeeding rates in mothers of preterm infants at 6 weeks postpartum. Methods Family Integrated Care (FICare) integrates and supports parents to actively participate in the care of their infant while in the NICU. Nested within the broader FICare trial, we will conduct an explanatory sequential mixed methods study to investigate if FICare improves maternal BSE and rates of breastmilk feeding in moderate and late preterm infants at discharge from the NICU. In phase 1, we will calculate the mean difference between admission and discharge BSE scores for the intervention group. Mothers who score in the top and bottom 20th percentile of change scores will be invited to participate in a semi-structured telephone interview exploring maternal experiences with infant feeding in the NICU. We will conduct inductive thematic analysis to identify and describe the facilitators and barriers of FICare on maternal feeding experiences. Once data saturation is achieved and themes have been established, phase 2 will revisit the quantitative data to determine whether FICare was impactful on BSE and breastmilk feeding rates. Findings from the qualitative and quantitative phases will be integrated to determine how infant feeding experiences on FICare units work to improve or detract from maternal BSE and rates of breastmilk feeding. Discussion FICare may help to improve maternal BSE and rates of breastmilk feeding in moderate and late preterm infants. Improved breastmilk feeding outcomes can have a substantial impact on overall infant health, developmental outcomes, and maternal-infant bonding and will help to improve long-term health outcomes for moderate and late preterm infants. Trial registration ( NCT02879799 ). Registered May 27, 2016 protocol version June 9, 2016 Version 2.
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    Compositional modelling of displacement processes in porous media
    (1973) Leung, Stephen T.; Aziz, Khalid
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    Compressibility factor of sour natural gases
    (1970) Wichert, Edward; Aziz, Khalid
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    Correction to: Family Integrated Care (FICare) in Level II Neonatal Intensive Care Units: study protocol for a cluster randomized controlled trial
    (2020-03-19) Benzies, Karen M; Shah, Vibhuti; Aziz, Khalid; Isaranuwatchai, Wanrudee; Palacio-Derflingher, Luz; Scotland, Jeanne; Larocque, Jill; Mrklas, Kelly; Suter, Esther; Naugler, Christopher; Stelfox, Henry T; Chari, Radha; Lodha, Abhay
    After publication of our article [1], the authors have reported mathematical errors made in the sample size calculation for this cluster randomized controlled trial (cRCT) (Benzies et al. 2017).
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    Effect of Alberta Family Integrated Care (FICare) on Breastfeeding Self-Efficacy and Breastmilk Feeding in Moderate and Late Preterm Infants
    (2019-07-03) Brockway, Meredith L.; Benzies, Karen Marie; Carr, Eloise C. J.; Aziz, Khalid
    Background: Breastfeeding self-efficacy (BSE) predicts breastfeeding outcomes in mothers of full-term infants; however, neonatal intensive care unit (NICU) practices may impede BSE and breastmilk feeding in mothers of preterm infants. Alberta Family Integrated Care (FICare) integrates parents into the care of their infant while in the NICU, by enhancing parent support, parent education and information sharing. The objective of this PhD work was to explore how Alberta FICare works to inform maternal BSE and resultant infant feeding outcomes in mothers of moderate (320/7 – 336/7 weeks) and late preterm infants (340/7 – 356/7 weeks). Methods: I conducted an explanatory sequential mixed-methods sub-study of the Alberta FICare trial. Based on BSE change scores between admission and discharge for mothers in the intervention group, I invited mothers scoring in the top or bottom quintiles to participate in interviews about infant feeding experiences in the NICU. Interviews were analyzed using inductive thematic analysis. To assess the effects of FICare on BSE and breastmilk feeding rates at discharge, I used repeated measures ANCOVA and Chi square. Finally, I used an integration matrix to integrate qualitative and quantitative findings. Results: Overall, I included 457 mothers/infant dyads (70 twins; M = 336/7 weeks gestation) from the FICare trial. Interviews with 14 mothers revealed three major themes: (a) institutional influences, (b) relationship with the pump, and (c) establishing breastfeeding. FICare was effective at improving BSE for mothers of late preterm infants, F(1, 232) = 3.97, p = .048, partial η2 = .017, but not for mothers of moderate preterm infants, F(1, 191) = 0.79, p = .375. Although exclusive breastmilk feeding rates at discharge in late preterm infants enrolled in the FICare group were higher compared to the standard care group, these differences were not statistically significant, 72.3% versus 62.2%, χ2(1) = 2.90, p = 0.089; no notable difference in exclusive breastmilk feeding was observed in moderate preterm infants. Conclusion: FICare is an effective model of care to improve BSE in mothers of late preterm infants at discharge from the NICU. More research is required to understand why FICare did not improve BSE in mothers of moderate preterm infants.
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    Effectiveness of Alberta Family Integrated Care on infant length of stay in level II neonatal intensive care units: a cluster randomized controlled trial
    (2020-11-28) Benzies, Karen M; Aziz, Khalid; Shah, Vibhuti; Faris, Peter; Isaranuwatchai, Wanrudee; Scotland, Jeanne; Larocque, Jill; Mrklas, Kelly J; Naugler, Christopher; Stelfox, H. T; Chari, Radha; Soraisham, Amuchou S; Akierman, Albert R; Phillipos, Ernest; Amin, Harish; Hoch, Jeffrey S; Zanoni, Pilar; Kurilova, Jana; Lodha, Abhay
    Abstract Background Parents of infants in neonatal intensive care units (NICUs) are often unintentionally marginalized in pursuit of optimal clinical care. Family Integrated Care (FICare) was developed to support families as part of their infants’ care team in level III NICUs. We adapted the model for level II NICUs in Alberta, Canada, and evaluated whether the new Alberta FICare™ model decreased hospital length of stay (LOS) in preterm infants without concomitant increases in readmissions and emergency department visits. Methods In this pragmatic cluster randomized controlled trial conducted between December 15, 2015 and July 28, 2018, 10 level II NICUs were randomized to provide Alberta FICare™ (n = 5) or standard care (n = 5). Alberta FICare™ is a psychoeducational intervention with 3 components: Relational Communication, Parent Education, and Parent Support. We enrolled mothers and their singleton or twin infants born between 32 0/7 and 34 6/7 weeks gestation. The primary outcome was infant hospital LOS. We used a linear regression model to conduct weighted site-level analysis comparing adjusted mean LOS between groups, accounting for site geographic area (urban/regional) and infant risk factors. Secondary outcomes included proportions of infants with readmissions and emergency department visits to 2 months corrected age, type of feeding at discharge, and maternal psychosocial distress and parenting self-efficacy at discharge. Results We enrolled 654 mothers and 765 infants (543 singletons/111 twin cases). Intention to treat analysis included 353 infants/308 mothers in the Alberta FICare™ group and 365 infants/306 mothers in the standard care group. The unadjusted difference between groups in infant hospital LOS (1.96 days) was not statistically significant. Accounting for site geographic area and infant risk factors, infant hospital LOS was 2.55 days shorter (95% CI, − 4.44 to − 0.66) in the Alberta FICare™ group than standard care group, P = .02. Secondary outcomes were not significantly different between groups. Conclusions Alberta FICare™ is effective in reducing preterm infant LOS in level II NICUs, without concomitant increases in readmissions or emergency department visits. A small number of sites in a single jurisdiction and select group infants limit generalizability of findings. Trial registration ClinicalTrials.gov Identifier NCT02879799 , retrospectively registered August 26, 2016.
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    Family Integrated Care (FICare) in Level II Neonatal Intensive Care Units: study protocol for a cluster randomized controlled trial
    (2017-10-10) Benzies, Karen M; Shah, Vibhuti; Aziz, Khalid; Isaranuwatchai, Wanrudee; Palacio-Derflingher, Luz; Scotland, Jeanne; Larocque, Jill; Mrklas, Kelly; Suter, Esther; Naugler, Christopher; Stelfox, Henry T; Chari, Radha; Lodha, Abhay
    Abstract Background Every year, about 15 million of the world’s infants are born preterm (before 37 weeks gestation). In Alberta, the preterm birth rate was 8.7% in 2015, the second highest among Canadian provinces. Approximately 20% of preterm infants are born before 32 weeks gestation (early preterm), and require care in a Level III neonatal intensive care unit (NICU); 80% are born moderate (32 weeks and zero days [320/7] to 336/7 weeks) and late preterm (340/7 to 366/7 weeks), and require care in a Level II NICU. Preterm birth and experiences in the NICU disrupt early parent-infant relationships and induce parental psychosocial distress. Family Integrated Care (FICare) shows promise as a model of care in Level III NICUs. The purpose of this study is to evaluate length of stay, infant and maternal clinical outcomes, and costs following adaptation and implementation of FICare in Level II NICUs. Methods We will conduct a pragmatic, cluster randomized controlled trial (cRCT) in ten Alberta Level II NICUs allocated to one of two groups: FICare or standard care. The FICare Alberta model involves three theoretically-based, standardized components: information sharing, parenting education, and family support. Our sample size of 181 mother-infant dyads per group is based on the primary outcome of NICU length of stay, 80% participation, and 80% retention at follow-up. Secondary outcomes (e.g., infant clinical outcomes and maternal psychosocial distress) will be assessed shortly after admission to NICU, at discharge and 2 months corrected age. We will conduct economic analysis from two perspectives: the public healthcare payer and society. To understand the utility, acceptability, and impact of FICare, qualitative interviews will be conducted with a subset of mothers at the 2-month follow-up, and with hospital administrators and healthcare providers near the end of the study. Discussion Results of this pragmatic cRCT of FICare in Alberta Level II NICUs will inform policy decisions by providing evidence about the clinical effectiveness and costs of FICare. Trial registration ClinicalTrials.gov, ID: NCT02879799 . Registered on 27 May 2016. Protocol version: 9 June 2016; version 2.
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    Investigation of grid orientation in a two-dimensional, compositional, three-phase steam model
    (1981) Abou-Kassem, Jamal Hussein; Aziz, Khalid
    A new three-phase steamflood numerical model has been developed. It is fully implicit with the Jacobian being calculated analytically. The model can operate in one and two dimensions, compositional and noncompositional modes with the choice of block-centered or pointdistributed grid systems employing five-point or nine-point finite difference schemes. Two different approaches have been employed and tested for their ability to remove the effect of grid orientation in steamflood simulation. The nine-point finite difference scheme reduces the grid orientation effects dramatically while the harmonic total mobility scheme is demonstrated to aggravate the problem rather than alleviate it. The applicability of the two-point upstream mobility in steamflood simulation has been investigated. It has been shown that the twopoint upstream mobility weighting may not be valid for thermal process simulators. The results of grid size and time step sensitivity analyses show that the time - pore volume injected relationship is very sensitive to grid size and to a much lesser extent to time step size. Sensitivity studies of grid size and time step are meaningful only if each is carried out while the other variable has been chosen to minimize the truncation error associated with it. The effects of well model, heat loss, and gas hysteresis on performance parameters and primary variables are also presented and discussed. Several side benefits have resulted from this investigation. These are: 1. A novel method of solution has been developed. It offers significant reductions in both storage and computational requirements for problems with large number of grid blocks. 2. A one-problem formulation method has been developed. It involves the introduction of new pseudo physical equilibrium constants. 3. A new implicit injection scheme which takes into account the effect of steam flashing on injectivity has been developed. 4. Equations for the well geometric factor in the well model f or a corner well block have been derived. 5. An analytical solution for the rate of heat loss to the surrounding formations has been developed.
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    Numerical modelling of the transport of pollutants from continuous sources
    (1973) Carr, Larry Alexander; Aziz, Khalid