Reservoir simulations integrated with geomechanics for West Sak Reservoir

Master's Project (M.S.) University of Alaska Fairbanks, 2014Geomechanics is the study of the mechanical behavior of geologic formations. Geomechanics plays an important role in the life of a well. Without a proper understanding of the geomechanics of a reservoir, the projects associated with it may run into problems related to drilling, completion, and production. Geomechanics is important for issues such as wellbore integrity, sand production, and recovery in heavy oil reservoirs. While studying geomechanics, proper weight is given to mechanical properties such as effective mean stress, volumetric strain, etc., and the changes that these properties cause in other properties such as porosity, permeability, and yield state. The importance of analyzing geomechanics increases for complex reservoirs or reservoirs with heavy oil. This project is a case study of the West Sak reservoir in the North Slope of Alaska. Waterflooding has been implemented as enhanced oil recovery method in the reservoir. In this study, a reservoir model is built to understand the behavior and importance of geomechanics for the reservoir. First, a fluid model is built. After that, reservoir simulation is carried out by building two cases: one coupled with geomechanics and one without geomechanics. Coupling geomechanics to simulations led to the consideration of many important mechanical properties such as stress, strain, subsidence etc. Once the importance of considering geomechanical properties is established, different injection and production pressure ranges are used to understand how pressure ranges affect the geomechanical properties. The sensitivity analysis defines safer pressure ranges contingent on whether the formation is yielding or not. The yielding criterion is based on Mohr's Coulomb failure criteria. In the case of waterflooding, injection pressure should be maintained at 3800 psi or lower and production at 1600 psi or higher. And if injection rates are used as the operating parameter, it should be maintained below 1000 bbls/day. It is also observed that injection pressure dominates the geomechanics of the reservoir

Body image perception, eating attitude and influence of media among undergraduate students of medical college in Delhi: a cross sectional study

Background: Body image perception is being shaped by unrealistic ideals portrayed in the media. Body dissatisfaction is one of the most consistent and robust risk factors for eating disorders, low self-esteem, depression, and obesity. Therefore, the objective of the current study is to ascertain the body image perception, abnormal eating attitudes and the role of media among undergraduate students of a medical college in Delhi, India.Methods: Cross-sectional study on 370 undergraduate medical students of Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India selected using stratified random sampling. India. Students completed a self-administered questionnaire which consist of demographic information, perceived body image, Eating Attitudes test (EAT-26) to assess eating attitudes, Socio Cultural Attitude Towards Appearance Questionnaire 3(SATAQ-3) scale for the role of media on body image perception. Data was analyzed using SPSS v21.Results: A total of 370 students (57.6% males and 42.4% females) aged 17-30 years, mean age of 20.30 years±2.02(SD). Abnormal body image perception was seen in 35.4%, 21.1% had abnormal eating attitude (EAT-26≥20), 36.5%, 40.5% agreed to be influenced by models and athletic figures in media respectively, 42.2% accepted that media was their source of information regarding standards of attractiveness, 27.6% felt pressured to be attractive according to SATAQ-3. Males more than females had disordered eating attitudes and felt media pressure to achieve an ideal body image. Significant association was observed between age and perceived body image (p=0.033), gender and EAT-26 score (p=0.039), EAT 26 and perceived body image (p=0.006), general internalization of media and perceived body image (p=0.003), internalization-general, internalization-athlete, media as source of information and EAT-26 score (<0.001, 0.001, 0.003 respectively).Conclusions: The media should take more responsibility to not represent unrealistic ideals of body image concerning both males and females. Educational and preventive efforts at institutional levels should be made to promote a healthy body image and eating behaviours

Chip-Scale, Sub-Hz Fundamental Sub-kHz Integral Linewidth 780 nm Laser through Self-Injection-Locking a Fabry-P\'erot laser to an Ultra-High Q Integrated Resonator

Today's state of the art precision experiments in quantum, gravimetry, navigation, time keeping, and fundamental science have strict requirements on the level and spectral distribution of laser frequency noise. For example, the laser interaction with atoms and qubits requires ultra-low frequency noise at multiple offset frequencies due to hyperfine atomic transitions, motional sidebands, and fast pulse sequencing. Chip-scale integration of lasers that meet these requirements is essential for reliability, low-cost, and weight. Here, we demonstrate a significant advancement in atomic precision light sources by realizing a chip-scale, low-cost, 780 nm laser for rubidium atom applications with record-low 640 mHz (white noise floor at 0.2 Hz$^2$/Hz) fundamental and 732 Hz integral linewidths and a frequency noise that is multiple orders of magnitude lower than previous hybrid and heterogeneous self-injection locked 780 nm lasers and lower noise than bulk microresonator implementations. The laser is a Fabry-P\'erot laser diode self-injection locked to an ultra-high Q photonic integrated silicon nitride resonator. This performance is enabled by a 145 million resonator Q with a 30 dB extinction ratio, the highest Q at 780 nm, to the best of our knowledge. We analyze the impact of our frequency noise on specific atomic applications including atomic frequency references, Rydberg quantum gates, and cold atom gravimeters. The photonic integrated resonator is fabricated using a CMOS foundry-compatible, wafer-scale process, with demonstrated integration of other components showing promise for a full system-on-a-chip. This performance is scalable to other visible atomic wavelengths, opening the door to a variety of transitions across many atomic species and enabling low-power, compact, ultra-low noise lasers impacting applications including quantum sensing, computing, clocks and more

A study of cytological pattern of cervical papanicolaou smears in western Rajasthan, India

Background: Cervical cancer is one of the most common cancers of Indian females. Western Rajasthan differs a lot from rest of India in respect of geographical conditions, environment, culture, population density etc. and it also has relatively lower literacy rate which is one of the risk factor for many diseases. The objective of this study was to estimate the prevalence of cervical cytological pattern in females of western Rajasthan by using conventional Papanicolaou (Pap) smears for the screening of inflammatory, premalignant and malignant lesions of the cervix.Methods: This cross sectional study was conducted at tertiary care institute of western Rajasthan for 1.5 year duration, on 1768 females who were screened by Pap smear examination. After staining with conventional Papanicolaou technique, all smears were classified as per Bethesda nomenclature.Results: Out of 1768 smears 1039 (58.7%) were abnormal Pap smears, 445 (25.1%) were normal Pap smears while 284 (16.1%) smears had inadequate sample material to be examined. Out of 1039 abnormal smears, 956 (92.01%) smears reported to have inflammatory/reactive changes whereas 26 (2.50%) had atrophic changes in Pap smear and abnormality in epithelial cell was reported in 57(5.49%) smears.Conclusions: Pap smear examination is an effective screening procedure to detect cervical cytological abnormalities. Routine cytological screening by Pap smear should be offered to all women above 19 years or within 3 years of sexual activity. It is recommended to improve the awareness about the disease amongst females and skills of health care personal about proper preparation of Pap smear

Photonic integrated beam delivery in a rubidium 3D magneto-optical trap

Cold atoms are important for precision atomic applications including timekeeping and sensing. The 3D magneto-optical trap (3D-MOT), used to produce cold atoms, will benefit from photonic integration to improve reliability and reduce size, weight, and cost. These traps require the delivery of multiple, large area, collimated laser beams to an atomic vacuum cell. Yet, to date, beam delivery using an integrated waveguide approach has remained elusive. We report the demonstration of a 87Rb 3D-MOT using a fiber-coupled photonic integrated circuit to deliver all beams to cool and trap > 1 x 10^6 atoms to near 200 {\mu}K. The silicon nitride photonic circuit transforms fiber-coupled 780 nm cooling and repump light via waveguides to three mm-width non-diverging free-space cooling and repump beams directly to the rubidium cell. This planar, CMOS foundry-compatible integrated beam delivery is compatible with other components, such as lasers and modulators, promising system-on-chip solutions for cold atom applications

Prevalence and pattern of anemia in the second and third trimester pregnancy in Western Rajasthan

Background: Anemia in pregnancy is related to maternal-fetal morbidity and mortality. In developing countries like India it is important to study prevalence and pattern of anemia in pregnancy especially in the region with higher maternal mortality rate like western Rajasthan. The main objective was to study the prevalence and pattern of anemia in second and third trimester pregnant females in western Rajasthan.Methods: In this cross sectional study females with second and third trimester pregnancy were evaluated for presence of anemia with its morphological type and severity.Results: 17,552 second and third trimester pregnant females were evaluated and prevalence of anemia was found 48.4%. The percentages of mild, moderate and severe anemia were 35.1%, 51.3% and 13.4% respectively. Most common morphological type was microcytic hypochromic anemia (51%) followed by normocytic normochromic anemia (32%), dimorphic anemia (13%) and macrocytic anemia (4%).  Conclusions: There is high prevalence of anemia in pregnant females. This warrants the need of proper prophylaxis and early diagnosis of anemia in pregnancy to minimize the maternal-fetal morbidity and mortality

Physico-chemical properties based differential toxicity of graphene oxide/reduced graphene oxide in human lung cells mediated through oxidative stress

Goraphene derivatives (GD) are currently being evaluated for technological and biomedical applications owing to their unique physico-chemical properties over other carbon allotrope such as carbon nanotubes (CNTs). But, the possible association of their properties with underlying in vitro effects have not fully examined. Here, we assessed the comparative interaction of three GD - graphene oxide (GO), thermally reduced GO (TRGO) and chemically reduced GO (CRGO), which significantly differ in their lateral size and functional groups density, with phenotypically different human lung cells; bronchial epithelial cells (BEAS-2B) and alveolar epithelial cells (A549). The cellular studies demonstrate that GD significantly ineternalize and induce oxidative stress mediated cytotoxicity in both cells. The toxicity intensity was in line with the reduced lateral size and increased functional groups revealed more toxicity potential of TRGO and GO respectively. Further, A549 cells showed more susceptibility than BEAS-2B which reflected cell type dependent differential cellular response. Molecular studies revealed that GD induced differential cell death mechanism which was efficiently prevented by their respective inhibitors. This is prior study to the best of our knowledge involving TRGO for its safety evaluation which provided invaluable information and new opportunities for GD based biomedical applications

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries