Stigma contributes to the burden of individuals and families affected by Sickle cell disease (SCD) and causes delay in appropriate care seeking. The aim of this study is to examine the levels and ...associations between stigma, social support, self-efficacy, and self-care actions among adult patients with SCD in Oman using a cross-sectional, correlational design. Of the 264 participants, 56.1% (n = 148) were males, with mean age of 30.1 years (SD 7.7). Half of the participants were married, and 88.3% had no other associated diseases. The results demonstrate that patients in Oman suffer from health-related stigma. However, social support, self-efficacy, and self-care actions were reported to be high and correlated with several clinical and demographic variables. Based on the results, effective, low-cost interventions such as psycho-educational groups, individual counseling, or group therapies might be developed. They can promote belief in enhanced efficacy and improved SCD adaptation, thereby increasing patient, and provider satisfaction.
Background. Delirium is a common disorder among patients admitted to intensive care units. Identification of the predicators of delirium is very important to improve the patient’s quality of life. ...Methods. This study was conducted in a prospective observational design to build a predictive model for delirium among ICU patients in Oman. A sample of 153 adult ICU patients from two main hospitals participated in the study. The Intensive Care Delirium Screening Checklist (ICDSC) was used to assess the participants for delirium twice daily. Result. The results showed that the incidence of delirium was 26.1%. Multiple logistic regression analysis showed that sepsis (odds ratio (OR) = 9.77; 95% confidence interval (CI) = 1.91–49.92; P<0.006), metabolic acidosis (odds ratio (OR) = 3.45; 95% confidence interval CI = 1.18–10.09; P=0.024), nasogastric tube use (odds ratio (OR) 9.74; 95% confidence interval (CI) = 3.48–27.30; P≤0.001), and APACHEII score (OR = 1.22; 95% CI = 1.09–1.37; P≤0.001) were predictors of delirium among ICU patients in Oman (R2=0.519, adjusted R2=0.519, P≤0.001). Conclusion. To prevent delirium in Omani hospitals, it is necessary to work on correcting those predictors and identifying other factors that had effects on delirium development. Designing of a prediction model may help on early delirium detection and implementation of preventative measures.
Triple switch, triple mode (TSTM) DC-DC converters find extensive utilization in renewable energy applications. Unlike other DC-DC converters, TSTM converters operate with two duty cycles ...(<inline-formula><tex-math notation="LaTeX">d</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">d_{1}</tex-math></inline-formula>), achieving maximum power point tracking (MPPT) and output voltage regulation simultaneously. However, these converters often exhibit high voltage stress on the switches due to resonance caused by mismatched switch/inductor parameters. This paper proposes a new TSTM dc-dc converter for high voltage gain with low voltage stress. The advantages of the proposed converter include (i) elimination of resonance due to parameters mismatch, resulting in the suppression of voltage oscillations, (ii) flexibility to regulate the output voltage with two duty cycles, and (iii) high voltage gain over a wide range of duty cycles. The paper provides a detailed explanation of the converter topology, working principle, steady-state analysis, external characteristics, and closed-loop controller design. The design guidelines and performance comparison are also presented. A 460 W laboratory setup is built, and experimental verification is conducted for the voltage conversion from 24 V to 272 V.
Dual-buck (DB) structured ac-ac converters are becoming advanced due to their inherent protection from open- and short-circuit risks, and elimination of commutation issue. However, the existing DB ...ac-ac converters provide restricted bipolar voltage operations with a large semiconductor device count and underutilized inductors. This article proposed a new reduced switch DB ac-ac converter without commutation issue. The propose converter provides multiple buck-boost voltage operations with noninverting and inverting outputs, making it a flexible topology for various ac voltage applications. The propose converter exhibits the continuous input and output currents irrespective of operation mode, and performs well with nonunity power factor loads. The positive and negative voltage gains of the proposed converter can address the grid voltage sag and swell issues, respectively, making it right candidate for application as dynamic voltage restorer. A detailed comparative evaluation is carried out with existing DB converters, which validated the effectiveness of the proposed converter, including; reduced semiconductor device count and their power ratings, reduced inductor sizes with improved magnetic utilization, enhanced voltage compensation ranges, and better efficiency. A laboratory scale hardware prototype of the proposed converter is built and thoroughly tested to validate its operation.
This article proposes a new H-bridge structured bipolar pulsewidth modulation (PWM) buck-boost ac-ac converter based on the nondifferential ac choppers. The proposed converter can generate simple ...identical noninverting and inverting buck-boost voltage outputs by modulating one phase leg with single control duty ratio (<inline-formula><tex-math notation="LaTeX">{d}_1</tex-math></inline-formula> or <inline-formula><tex-math notation="LaTeX">{d}_2</tex-math></inline-formula>). It can also provide flexible identical noninverting and inverting buck-boost operations by modulating both phase legs with two control duty ratios (<inline-formula><tex-math notation="LaTeX">{d}_1</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">{d}_2</tex-math></inline-formula>). In the proposed topology, the use of nondifferential ac choppers eliminates the complementary switching of ac switches and related inductor open-circuit issue. Moreover, half the switching devices are configured as switching-cell units to avoid shoot-through occurrence due to accidental turn- on of complementary switches. Therefore, the proposed topology is free from commutation issue and can abolish PWM deadtimes to produce high-quality output with improved utilization of switch duty ratios. It also provides continuous input current and can perform normally with reactive loads. It has the potential to mitigate both voltage sags and swells (due to bipolar operation) when used as series voltage compensator; and unlike the existing nondifferential bipolar ac-ac converters, it can provide compensation for more intense voltage sags (of above 50%) as well. In-depth analysis of the proposed topology and hardware verifications are provided in this article.
Single-phase dual-buck ac-ac (DBAC) converters are gaining attention due to their intrinsic protection from shoot-through and open-circuit problems of conventional ac-ac converters. However, ...researches on DBAC converters are mainly concentrated around unipolar topologies. In a few developed bipolar topologies till date, the inverting buck-boost operations (for series voltage injection and step-variable frequency outputs) are inefficient and burdened by large voltage and current stresses ( v in + v o and i in + i o ) of switching devices and ripples of passive elements. In this article, an efficient dual-buck structured buck-boost ac-ac converter is proposed, with the following features: no voltage source shoot-through and inductor open-circuit problems, natural attainment of safe-commutation without additional protection circuitry or complex control, no need of PWM dead-times, and elimination of high-frequency conduction of MOSFET's body diodes and related slow reverse recovery issues. The proposed converter provides distinct type efficient inverting and non-inverting buck (EINIBu) and boost (EINIBo) operations, with smaller switch voltage/current stresses ( v in / v o and i in / i o ) and passive component ripples. Combined inverting and non-inverting buck-boost (CINIBB) operations are also proposed with separate tuning of buck and boost voltage transfer ratios. A simple adaptable switching strategy provides the switch control pulses for all circuit operations by modulating the buck and boost control reference signals. The proposed converter provides sustained input/output currents and performs well with non-resistive loads. Extensive theoretical analysis is presented followed by practical verifications on a 400-VA laboratory circuit.
In this article, we propose an improved high-boost-gain split-source inverter (SSI) for renewable energy generation. The proposed inverter retains the features of the existing SSIs, such as ...single-stage boost inversion with a reduced number of passive components and elimination of the inverse modulation-duty relationship constraint of the impedance-source inverters. It also provides additional features that include higher boost inversion ability than existing SSIs to connect low-voltage renewable energy sources to the grid, no voltage-source short-circuit issue, which increases the robustness of the proposed inverter and pulsewidth modulation dead times can be relieved, and the negative input dc-terminal and ac-neutral are electrically connected in the proposed inverter, resulting in a constant common-mode voltage and elimination of leakage ground currents for grid-interfaced PV power systems. A detailed circuit operation and analysis is provided, and experiments are performed on a 400-VA prototype inverter to confirm the working of the proposed topology.
Inter Professional Education and Collaboration (IPEC) is grounded on mutual respect, enhances collaborative practice, and increases satisfaction among health care professionals.
The study was ...conducted to assess the level of knowledge and readiness for IPEC among nursing students.
The student's level of knowledge was assessed using a 20 item questionnaire while their readiness for IPEC was measured using the Readiness for Interprofessional Learning Scale (RIPLS) comprising 19 items. A total of 125 nursing students participated in the study and data was analyzed using Statistical Package for the Social Sciences (SPSS) version 25
The mean level of knowledge was 44.41 with SD of 4.72. The mean readiness score was 79.09 with the SD of 11.77. There is no significant association between the knowledge and readiness of nursing students regarding IPEC and their demographic variables at 0.05 confidence level.
Majority of the students had moderately adequate knowledge about IPEC and high level of readiness towards IPEC. This implies that when appropriately implemented, the students will reap the benefits of IPEC, which has the potential to improve their ability to provide holistic nursing care to their patients.
This dissertation presents the design, development, and experimental results of the Scaled Heat Exchange Frequency Response Analysis (SHEFRA) experiment, which aimed to investigate the use of ...frequency response methods for measuring quasi-steady Nusselt number values in forced convection of a surrogate fluid for molten fluoride salt in circular ducts. The dynamic response in the flow channel was initiated by a periodically-varying fluid temperature at the inlet. Initial experimental results obtained from the SHEFRA experiment suggest that quasi-steady conditions are achievable for laminar flow conditions, showing good agreement with steady-state analytical predictions. The theoretical modeling and frequency scaling analysis provided insights into the relevant dimensionless parameters and their impact on the system’s behavior, allowing for optimal experimental parameters and conditions to be determined. Quasi-steady state heat transfer conditions are best approximated at high or low values of a dimensionless parameter, b*, defined as the dimensionless frequency multiplied by the ratio of wall thermal capacitance and fluid thermal conductivity. At the limit of high frequency, the quasi-steady regime approximates the analytically-predicted steady state heat transfer with an isothermal wall temperature boundary condition. Meanwhile, at the limit of low frequency, the quasi-steady state conditions approximate steady state pre- dictions for a constant flux boundary condition. In comparison, high frequency tests resulted in a better approximation of quasi-steady state near the inlet of the test section. The most deviation in the instantaneous Nusselt number exists in the middle frequency range. The results suggest that additional experimental data, covering a range of Prandtl and Reynolds numbers of interest for molten fluoride salt reactor operation, can be used to create Nusselt number correlations that can be compared with prototypical molten salt experiment data and hence qualify the use of surrogate fluids in scaled experiments. Additionally, frequency response parameter estimation techniques presented in this dissertation offer promising av- enues for future research in improving the accuracy of Nusselt number measurements with the potential of estimating other system parameters such as thermophysical properties. The SHEFRA experiment demonstrates the potential of using surrogate fluids and frequency response methods to obtain high-fidelity heat transfer data measurements relevant for molten salt reactor development.
