Three-dimensional inviscid analysis of radial turbine flow and a limited comparison with experimental data

The three-dimensional inviscid DENTON code is used to analyze flow through a radial-inflow turbine rotor. Experimental data from the rotor are compared with analytical results obtained by using the code. The experimental data available for comparison are the radial distributions of circumferentially averaged values of absolute flow angle and total pressure downstream of the rotor exit. The computed rotor-exit flow angles are generally underturned relative to the experimental values, which reflect the boundary-layer separation at the trailing edge and the development of wakes downstream of the rotor. The experimental rotor is designed for a higher-than-optimum work factor of 1.126 resulting in a nonoptimum positive incidence and causing a region of rapid flow adjustment and large velocity gradients. For this experimental rotor, the computed radial distribution of rotor-exit to turbine-inlet total pressure ratios are underpredicted due to the errors in the finite-difference approximations in the regions of rapid flow adjustment, and due to using the relatively coarser grids in the middle of the blade region where the flow passage is highly three-dimensional. Additional results obtained from the three-dimensional inviscid computation are also presented, but without comparison due to the lack of experimental data. These include quasi-secondary velocity vectors on cross-channel surfaces, velocity components on the meridional and blade-to-blade surfaces, and blade surface loading diagrams. Computed results show the evolution of a passage vortex and large streamline deviations from the computational streamwise grid lines. Experience gained from applying the code to a radial turbine geometry is also discussed

Generation of a composite grid for turbine flows and consideration of a numerical scheme

A composite grid was generated for flows in turbines. It consisted of the C-grid (or O-grid) in the immediate vicinity of the blade and the H-grid in the middle of the blade passage between the C-grids and in the upstream region. This new composite grid provides better smoothness, resolution, and orthogonality than any single grid for a typical turbine blade with a large camber and rounded leading and trailing edges. The C-H (or O-H) composite grid has an unusual grid point that is connected to more than four neighboring nodes in two dimensions (more than six neighboring nodes in three dimensions). A finite-volume lower-upper (LU) implicit scheme to be used on this grid poses no problem and requires no special treatment because each interior cell of this composite grid has only four neighboring cells in two dimensions (six cells in three dimensions). The LU implicit scheme was demonstrated to be efficient and robust for external flows in a broad flow regime and can be easily applied to internal flows and extended from two to three dimensions

An overview of indoor air quality and its impact on respiratory health among Malaysian school-aged children

The indoor environment is a major source of human exposure to pollutants. Some pollutants can have concentrations that are several times higher indoors than outdoors. Prolonged exposure may lead to adverse biologic effects, even at low concentrations. Several studies done in Malaysia had underlined the role of indoor air pollution in affecting respiratory health, especially for school-aged children. A critical review was conducted on the quantitative literature linking indoor air pollution with respiratory illnesses among school-aged children. This paper reviews evidence of the association between indoor air quality (IAQ) and its implications on respiratory health among Malaysian school-aged children. This review summarizes six relevant studies conducted in Malaysia for the past 10 years. Previous epidemiologic studies relevant to indoor air pollutants and their implications on school-aged children's respiratory health were obtained from electronic database and included as a reference in this review. The existing reviewed data emphasize the impact of IAQ parameters, namely, indoor temperature, ventilation rates, indoor concentration of carbon dioxide (CO2), carbon monoxide (CO), particulate matters (PM), volatile organic compounds (VOCs), nitrogen dioxide (NO2) and airborne microbes, on children's respiratory health. The study found that most of the Malaysian school-aged children are exposed to the inadequate environment during their times spent either in their houses or in their classrooms, which is not in compliance with the established standards. Children living in households or studying in schools in urban areas are more likely to suffer from respiratory illnesses compared with children living in homes or studying in schools in rural areas

Health-related quality of life in pediatric patients with leukemia in Singapore: a cross-sectional pilot study

There has been a paradigm shift in health service delivery to a more holistic approach, which considers Quality of Life (QoL) and overall functioning. Health-Related Quality of Life (HRQoL) is a multidimensional construct that encompasses physical functioning as well as psychosocial aspects of emotional and social functioning. This study explored factors related to HRQoL in Asian pediatric patients with leukemia in Singapore. The available variables included: age, treatment duration, household income, gender, ethnicity, religion, diagnosis, and phase of treatment. It is hypothesized that the relationships will be significant. In the current study, there were 60 patients (60% males) with leukemia; their ages ranged from 1 to 21 years (Mean = 8.03, Standard Deviation = 4.55). The hypothesis was partially supported. Age had a significant positive relationship with physical functioning, r(60) = 0.28, p < 0.05, physical health, r(60) = 0.28, p < 0.05, and the total HRQoL score, r(60) = 0.29, p < 0.05. Treatment duration had a positive relationship with school functioning, r(60) = 0.28, p < 0.05. All other correlations were statistically non-significant. The effects of the available psychosocial variables of gender, ethnicity, and religion were examined on scores from the Pediatric Quality of Life Inventory (PedsQL). Ethnicity had a significant effect on social functioning, U = 292.00, p < 0.05, r = 0.3 (medium effect size). Specifically, Chinese (Median = 85.00, n = 33) had significantly higher scores on social functioning than others (Median = 70.00, n = 27). The remaining comparisons were statistically non-significant. The current findings added to QoL research, and provided an impetus for more research in the area of HRQoL for children with leukemia in Singapore

Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

Smartphone apps for mindfulness interventions with suicidality in Asian youths: literature review

Background: The advent of mobile technology has ushered in an era where smartphone applications can be used for intervention for suicidality. Objective: Review recent research relevant to smartphone application that can be used for mindfulness intervention for suicidality in Asian youths. Methods: The inclusion criteria for this review is papers published in peer reviewed journals from 2007 to 2017 with usage of search terms namely ‘smartphone application’, and ‘mindfulness’, assessed against the inclusion criteria and screened by an experienced Asian clinician to be of clinical utility for mindfulness intervention for suicidality with Asian youths. Results: Initial search on databases yielded 375 results. 14 Full text papers that fit the inclusion criteria were assessed for eligibility and 10 papers were included in the current review. Conclusions: This review highlighted the paucity of evidence-based and empirically validated research into effective smartphone applications that can be used for mindfulness interventions for suicidality with Asian youths

Live Migration in Emerging Cloud Paradigms

The elastic provisioning of resources and the capability to adapt to changing resource demand and environmental conditions on-the-fly are, probably, key success factors of cloud computing. Live migration of virtual resources is of pivotal importance in achieving such key properties. However, the ability to effectively and efficiently determine which resource to be migrated and where, by satisfying proper objectives and constraints, remains a research challenge. The existing literature is generally based on metaheuristics running a central resolver. Such an approach is not suitable because it only considers the quality-of-service aspect during the decision-making performance while ignoring the regulatory challenges. This column highlights the regulatory challenges associated with the cross-border dataflow implication of migration and stresses the need to adopt alternative decision approaches.postprin

Patient-Related Barriers to Timely Dialysis Access Preparation: A Qualitative Study of the Perspectives of Patients, Family Members, and Health Care Providers

Rational & Objective A key aspect of smooth transition to dialysis is the timely creation of a permanent access. Despite early referral to kidney care, initiation onto dialysis is still suboptimal for many patients, which has clinical and cost implications. This study aimed to explore perspectives of various stakeholders on barriers to timely access creation. Study Design Qualitative study. Setting & Participants Semi-structured interviews with 96 participants (response rate, 67%), including patients with stage 4 chronic kidney disease (n = 30), new hemodialysis patients with (n = 18) and without (n = 20) permanent access (arteriovenous fistula), family members (n = 19), and kidney health care providers (n = 9). Analytical Approach Thematic analysis. Results Patients reported differential levels of behavioral activation toward access creation: avoidance/denial, wait and see, or active intention. 6 core themes were identified: (1) lack of symptoms, (2) dialysis fear and practical concerns (exaggerated fear, pain, cost, lifestyle disruptions, work-related concerns, burdening their families), (3) evaluating value against costs/risks of access creation (benefits, threat of operation, viability, prompt for early initiation), (4) preference for alternatives, (5) social influences (hearsay, family involvement, experiences of others), and (6) health care provider interactions (mistrust, interpersonal tension, lack of clarity on information). Themes were common to all groups, whereas nuanced perspectives of family members and health care providers were noted in some subthemes. Limitations Response bias. Conclusions Individual, interpersonal, and psychosocial factors compromise dialysis preparation and contribute to suboptimal dialysis initiation. Our findings support the need for interventions to improve patient and family engagement and address emotional concerns and misperceptions about preparing for dialysis