62 research outputs found
Analyze Gelling Properties for Time-Dependent Non-Newtonian Fluids
Drilling fluids are visco-elastic materials. This means that they behave as a viscous fluid when subject to sufficient shear stress and like an elastic solid when they are in near static conditions. Both properties are time-dependent.
While drilling a well, there could be many instances when a change in the velocity of drilling fluid is required. For instance, we may have to adjust the pump flow rate depending upon the formation drilled. In a similar manner, there could be variations in the flow rate due to the movement of the drill string as it can move axially, rotationally, and side-wise. Another example is the change of flow rate owing to the difference in the flow geometry while passing from the annulus. In all these cases, the drilling fluid required a definite time to attain new equilibrium conditions.
Nevertheless, the time-dependence rheological properties of drilling fluids are usually not measured during drilling operations. Additionally, in the lab measurements, seldom are experiments performed beyond 30 minutes of resting time. Consequently, it is difficult to estimate how thixotropy impacts pressure losses in drilling operations. Against this backdrop, our research is focused on the analysis of the gelling properties of time-dependent non-Newtonian fluids.
We have systematically measured the time-dependence of the rheological properties of different samples of water-based and oil-based fluids with a scientific rheometer in order to capture how the gel strength of the drilling fluids responds to variations of other relevant parameters involved. Furthermore, we have analyzed the behaviours of those fluids for the longer resting times until no further gel strength is developed in them
Analyze Gelling Properties for Time-Dependent Non-Newtonian Fluids
Drilling fluids are visco-elastic materials. This means that they behave as a viscous fluid when subject to sufficient shear stress and like an elastic solid when they are in near static conditions. Both properties are time-dependent.
While drilling a well, there could be many instances when a change in the velocity of drilling fluid is required. For instance, we may have to adjust the pump flow rate depending upon the formation drilled. In a similar manner, there could be variations in the flow rate due to the movement of the drill string as it can move axially, rotationally, and side-wise. Another example is the change of flow rate owing to the difference in the flow geometry while passing from the annulus. In all these cases, the drilling fluid required a definite time to attain new equilibrium conditions.
Nevertheless, the time-dependence rheological properties of drilling fluids are usually not measured during drilling operations. Additionally, in the lab measurements, seldom are experiments performed beyond 30 minutes of resting time. Consequently, it is difficult to estimate how thixotropy impacts pressure losses in drilling operations. Against this backdrop, our research is focused on the analysis of the gelling properties of time-dependent non-Newtonian fluids.
We have systematically measured the time-dependence of the rheological properties of different samples of water-based and oil-based fluids with a scientific rheometer in order to capture how the gel strength of the drilling fluids responds to variations of other relevant parameters involved. Furthermore, we have analyzed the behaviours of those fluids for the longer resting times until no further gel strength is developed in them
Requirement Validation for Embedded Systems in Automotive Industry Through Modeling
Requirement validation contributes significantly toward the success of software projects. Validating requirements is also essential to ensure the correctness of embedded systems in the auto industry. The auto industry emphasizes a lot on the verification of car designs and shapes. Invalid or erroneous requirements lead to inappropriate designs and degraded product quality. Considering the required expertise and time for requirement validation, significant attention is not devoted to verification and validation of requirements in the industry. Currently, the failure ratio of software projects is significantly higher and the key reason for that appears to be the inappropriate and invalidated requirements at the early stages in the projects. To that end, we propose a model-based approach that uses the existing V&V model. Through virtual prototyping, the proposed approach eliminates the need to validate the requirements after each stage of the project. Consequently, the model is validated after the design phase and the errors in requirements are detected at the earliest stage. In this research, we performed two different case studies for requirement validation in the auto industry by using a modeling-based approach and formal technique using Petri nets. A benefit of the proposed modeling-based approach is that the projects in the auto industry domain can be completed in less time due to effective requirements validation. Moreover, the modeling-based approach minimizes the development time, cost and increases productivity because the majority of the code is automatically generated using the approach
Citizen engagement for co-creating low carbon smart cities: practical lessons from Nottingham City Council in the UK
Cities constitute three quarters of global energy consumption and the built environment is responsible for significant use of final energy (62%) and greenhouse gas emissions (55%). Energy has now become a strategic issue for local authorities (LAs) and can offer savings when budget cuts have threatened the provision of core services. Progressive LAs are exploring energy savings and carbon reduction opportunities as part of the sustainable and smart city agenda. This paper explores the role of citizens in smart city development as "buildings don't use energy: people do". Citizens have the potential to shape transitions towards smart and sustainable futures. This paper contributes to the growing evidence base of citizen engagement in low carbon smart cities by presenting novel insights and practical lessons on how citizen engagement can help in smart city development through co-creation with a focus on energy in the built environment. A case study of Nottingham in the UK, a leading smart city, is analysed using Arnstein's Ladder of Citizen Participation. Nottingham City Council (NCC) has pledged to keep "citizens at the heart" of its plans. This paper discusses learnings from two EU funded Horizon 2020 projects, REMOURBAN (REgeneration MOdel for accelerating the smart URBAN transformation) and eTEACHER, both of which aimed to empower citizens to reduce energy consumption and co-create smart solutions. Although these two projects are diverse in approaches and contexts, what unites them is a focus on citizen engagement, both face to face and digital. REMOURBAN has seen a "whole house" approach to retrofit in vulnerable communities to improve liveability through energy efficiency. User interaction and co-creation in eTEACHER has provided specifications for technical design of an energy saving App for buildings. eTEACHER findings reflect users' energy needs, understanding of control interfaces, motivations for change and own creative ideas. Citizens were made co-creators in eTEACHER from the beginning through regular communication. In REMOURBAN, citizens had a role in the procurement and bidding process to influence retrofit project proposals. Findings can help LAs to engage demographically diverse citizens across a variety of buildings and communities for low carbon smart city development
Assessment of factors affecting quality of life in oral squamous cell carcinoma patients using university of washington quality of life questionnaire
Introduction Post-treatment Quality of Life (QOL) is considered an important outcome in cancer patients. A number of questionnaire tools have been designed for its assessment. University of Washington Quality of Life (UW QOL) questionnaire version four is a reliable tool for assessment of post-treatment QOL in oral squamous cell carcinoma (OSCC) patients. Our aim was to identify the post-treatment problems faced by OSCC patients and to assess the impact of clinical factors affecting post-treatment QOL by using UW QOL (version four) questionnaire. Methods The study was conducted on 59 patients with OSCC who were treated with curative intent at Patel Hospital, Karachi from August 2015 to September 2015. Patients were asked to fill the UW QOL questionnaire (version four) on their follow-up visit. Results Overall mean composite QOL score was 66.59 ± 16.98. Chewing and saliva (dryness of mouth) had the lowest scores (38.98 ± 37.2 and 56.78 ± 41.4, respectively) among all domains while pain and anxiety had the highest scores (80.93 ± 20.4 and 79.66 ± 29.8, respectively). Patients having tumors of the tongue, late stage (III and IV) tumors, and restricted mouth opening had significantly lower mean composite QOL scores. Patients with tongue tumors revealed significantly lower scores for pain, swallowing, mood, and anxiety. Patients with late-stage tumors showed significantly lower scores for chewing, swallowing, taste, saliva, appearance, anxiety, and recreation. Patients with restricted mouth opening had significantly lower scores for pain, speech, appearance, recreation, and anxiety domains. Conclusion Different clinical features have different impacts on QOL in terms of problems faced by the patients. Features having a significant effect should be identified, and measures focused on most relevant problems should be employed in order to improve the post-treatment QOL
Orbital Embryonal Rhabdomyosarcomain Karachi (1998-2002)
Objective: To study the epidemiology of ocular Rhabdomyosarcoma (ORMS) in Karachi.
Methods: Incident ORMS cases resident of Karachi, registered at Karachi Cancer Registry (KCR) during 1st January 1998 to 31st December 2002 were included in the study. The data were classified using ICD-O2; computerized with Canreg-3, and analyzed using SPSS 10.0.
Results: Ten cases of ORMS were reported to KCR during 1998-2002. RMS originated in the orbit in eight cases, conjunctiva in one and eyelid in one. Nine cases presented with proptosis, associated with conjunctivitis in four cases. One case presented with eyelid swelling. The crude annual incidence rate was 0.13/100,000, the age standardized rate was 0.3/100,000. The mean age of childhood cases was 10.4 years (95% CI 4.0; 16.7); and adult cases was 24.8 years (95% CI 12.8; 36.7). At presentation, eight patients were older than 10 years and three were older than 20 years. Five cases were categorized as childhood malignancies. Tumors were a TNM stage III disease at presentation in eight cases; survival at the end of one year was 70%, and at the end of two years 20%. There were no survivors at the end of three years.
Conclusion: ORMS in Karachi is a disease with a dismal survival. It may reflect a late presentation, or shorter adult ORMS survival or a manifestation of a different genetic pattern, associated with rapid evolution and poor prognosis. Health education for the population, especially parents and health providers is essential for early ORMS diagnosis. Pediatricians, ophthalmologists and health professionals, can play a vital role. Healthcare planning should focus on capacity building for ophthalmologic screening. Cytogenetic studies are advised to determine the genetic pattern
Poly[[di-μ-aqua-(μ-4-formyl-2-methoxyphenolato)disodium] 4-formyl-2-methoxyphenolate]
In the title coordination polymer, {[Na2(C8H7O3)(H2O)4](C8H7O3)}n, all the non-H atoms except the water O atoms lie on a crystallographic mirror plane. One sodium cation is bonded to four water O atoms and one vanillinate O atom in a distorted square-based pyramidal arrangement; the other Na+ ion is six-coordinated by four water O atoms and two vanillinate O atoms in an irregular geometry. One of the vanillinate anions is directly bonded to two sodium ions, whilst the other only interacts with the polymeric network by way of hydrogen bonds. In the crystal, a two-dimensional polymeric array is formed; this is reinforced by O—H⋯O hydrogen bonds, which generate R
2
1(6) and R
2
2(20) loops
Characteristics of Fine Particulate Matter (PM2.5) over urban, suburban and rural areas of Hong Kong
In urban areas, Fine Particulate Matter (PM2.5) associated with local vehicle emissions can cause respiratory and cardiorespiratory disease and increased mortality rates, but less in rural areas. However, Hong Kong may be a special case since the whole territory often suffers from regional haze from nearby mainland China, as well as local sources. Therefore, to understand which areas of Hong Kong may be affected by damaging levels of fine particulates, PM2.5 data were obtained from March 2005 to February 2009 for urban, suburban and rural air quality monitoring stations; namely Central (city area, commercial area, and urban populated area), Tsuen Wan (city area, commercial area, urban populated, and residential area), Tung Chung (suburban and residential area), Yuen Long (urban and residential area), and Tap Mun (remote rural area). To evaluate the relative contributions of regional and local pollution sources, the study aims to test the influence of weather conditions on PM2.5 concentrations. Thus meteorological parameters including temperature, relative humidity, wind speed, and wind directions were obtained from the Hong Kong Observatory.. The results showed that Hong Kong’s air quality is mainly affected by regional aerosol emissions, either transported from the land or ocean, as similar patterns of variations in PM2.5 concentrations were observed over urban, suburban, and rural areas of Hong Kong. Only slightly higher PM2.5 concentrations were observed over urban sites, such as Central, compared to suburban and rural sites, which could be attributed to local automobile emissions. Results showed that meteorological parameters have potential to explain 80% of the variability in daily mean PM2.5 concentrations at Yuen Long, 77% at Tung Chung, 72% at Central, 71% at Tsuen Wan, and 67% at Tap Mun during the spring to summer part of the year. The results provide not only a better understanding of the impact of regional long-distance transport of air pollutants on Hong Kong’s air quality but also a reference for future regional-scale collaboration on air quality management
EFFECT OF WASTE POLYETHYLENE TEREPHTHALATE BOTTLE FIBERS ON THE MECHANICAL PROPERTIES OF RECYCLED CONCRETE
The use of beverage containers, most of which are made of polyethylene terephthalate bottles, results in several problems with regard to sustainability. The purpose of this study was to evaluate and contrast the impact on the mechanical characteristics of concrete caused by the incorporation of polyethylene terephthalate bottle fibres in varying amounts. These fibres were generated by cutting bottles into precise dimensions (width of 5 mm and length of 25 mm), and they were used in various concentrations such as 0,25 %; 0,5 % and 1,0 % by volume of concrete with different amounts of recycled aggregate. To verify the reliability of the outcomes of the experiment, a statistical analysis was performed. According to the results, the concrete that contained 0 % recycled coarse aggregate and varying amounts of plastic fibres had a greater degree of workability compared with concrete that had either 50 % or 100 % recycled coarse aggregate. The comprehensive test findings demonstrated that the addition of polyethylene terephthalate fibres decreased compressive and split tensile strength. The study concluded that certain parameters, such as plastic fibres, curing days, and recycled aggregate, interacted together in a synergistic manner to impact the compressive and splitting tensile strengths of the concrete, with proposed equations for their prediction
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