Thermal Hydraulic Modeling of Once-Through Steam Generator by Two-Fluid U-Tube Steam Generator Code

The THERMIT U-tube steam generator (THERMIT-UTSG) code was used for evaluation for the parametric study of a scaled once-through pressurized water reactor steam generator (OTSG) made by Babcock & Wilcox. The results of the code were compared to the experimental data of the 19-tube OTSG and a simple heat transfer code that was developed by Osakabe. The main calculated thermodynamic parameters were primary-secondary fluid temperatures, tube wall internal and external temperatures that were subjected to primary and the secondary fluid, and the secondary fluid vapor quality. The assessed code can be used for modeling the OTSGs with some modification. The results of THERMIT-UTSG were in agreement with the experimental results and the prediction of Osakabe’s numerical model

Thermal Hydraulic Modeling of Once-Through Steam Generator by Two-Fluid U-Tube Steam Generator Code

The THERMIT U-tube steam generator (THERMIT-UTSG) code was used for evaluation for the parametric study of a scaled once-through pressurized water reactor steam generator (OTSG) made by Babcock & Wilcox. The results of the code were compared to the experimental data of the 19-tube OTSG and a simple heat transfer code that was developed by Osakabe. The main calculated thermodynamic parameters were primary-secondary fluid temperatures, tube wall internal and external temperatures that were subjected to primary and the secondary fluid, and the secondary fluid vapor quality. The assessed code can be used for modeling the OTSGs with some modification. The results of THERMIT-UTSG were in agreement with the experimental results and the prediction of Osakabe's numerical model

A comparison between the risk of needle stick injuries among nurses in emergency wards and nurses in other wards of hospitals

Background and Aim: Nursing work in emergency departments is tangled with unbearable hardship and high working pressure as well as an increased risk of occupational injuries. Needle stick injury is among such risks. Incidence of these injuries differs in different hospital wards. This study aimed to determine needle stick injury risks in emergency ward in comparison with other wards of Qazvin hospitals in 2010. Materials and Methods: This historical cohort study was done on nursing staff working in Qazvin hospitals. Statistical population included nursing staffs at Qazvin hospitals who were responsible for direct patient care. From among nurses working in the emergency wards, 52 were selected. Control group consisted of 258 nurses who had worked in other wards of the same hospitals. The research instrument was a self-administered questionnaire. To determine validity and reliability of the Instrument, content validity and test-retest were performed. The collected data was analyzed using Independent t test, Mann-Whitney, Chi-Square, Fisher Exact Test, and Logistic Regression through SPSS (version 16) at 0.05. Results: Risk of injury in emergency ward was three times more than other wards (p<0.01). The average numbers of beds in emergency wards and in other wards were 24.2±.6.7 and 18.1± 10.7 respectively. Nonetheless, number of nurses on different shifts in emergency wards, especially in the evening shift, was significantly lower (p<0.05). However, according to logistic regression analysis, the work in emergency ward was an independent risk factor for needle stick injuries (p<0.05). Conclusion: The risk of needle stick injuries among nurses in emergency wards is dramatically higher than other wards. It seems that more beds per nurse affects this increased risk. It is proposed that the number of nurses in emergency departments be increased, especially in the evening shift so that the risk of this serious injury may be reduced

The usual suspects: How psychological motives and thinking styles predict the endorsement of well-known and COVID-19 conspiracy beliefs

Research on belief in conspiracy theories identified many predictors but often failed to investigate them together. In the present study, we tested how the most important predictors of beliefs in conspiracy theories explain endorsing COVID‐19 and non‐COVID‐19 conspiracy theories and conspiracy mentality. Apart from these three measures of conspiratorial thinking, participants (N = 354) completed several measures of epistemic, existential, and social psychological motives, as well as cognitive processing variables. While many predictors had significant correlations, only three consistently explained conspiratorial beliefs when included in one model: higher spirituality (specifically eco‐awareness factor), higher narcissism, and lower analytical thinking. Compared to the other two conspiratorial measures, predictors less explained belief in COVID‐19 conspiracy theories, but this depended on items' content. We conclude that the same predictors apply to belief in both COVID and non‐COVID conspiracies and identify New Age spirituality as an important contributor to such beliefs

Hemodynamic effect of atrioventricular and interventricular dyssynchrony in patients with biventricular pacing: Implications for the pacemaker syndrome

Background/Objectives: Pacemaker syndrome was mainly described as the sequel of atrioventricular (AV) dyssynchrony. The role of interventricular (VV) dyssynchrony has not been studied yet. The aims of this study were to noninvasively assess the hemodynamic effects of different ventricular pacing sites with and without AV and VV dyssynchrony and to observe the patients for clinical symptoms of the pacemaker syndrome during the AV sequential and ventricular-only pacing modes. Materials and Methods: Between March 2009 and February 2010, 40 patients (28 men; mean age, 61 ± 15 years) with biventricular (BiV) device were enrolled. Mean systolic and diastolic blood pressures (BP) of 5 beats were measured 5 minutes after each mode change using fingertip plethysmography. The patients were also observed for the occurrence of symptoms suggestive of the pacemaker syndrome, including dyspnea, palpitations, dizziness, presyncope, and syncope. Results: There was no difference in mean systolic BP among different ventricular-only pacing modes (all P = NS). However, mean systolic BP was significantly higher in AV sequential biventricular pacing (DDD-BiV) compared with ventricular-only pacing modes (all P0.05). Conclusions: The present study showed that the non-AV sequential BiV and LV pacing may have no significant benefit compared with RV pacing in terms of systolic blood pressure. However, there was marked hemodynamic improvement following mode change to AV sequential BiV pacing. This study may have important implications for pathogenesis of pacemaker syndrome

Cardiogoniometry can predict positive response to cardiac resynchronization therapy � A proof of concept study

Background: According to American Heart Association guidelines, QRS duration and morphology are used to select patients for cardiac resynchronization therapy (CRT). But still there are some patients who are not responding to this device. We investigated whether the Cardiogoniometry (CGM) as a three-dimensional vectorcardiogram method can improve patient selection. Methods: Echocardiography and CGM were performed for 25 consecutive patients with Left bundle branch morphology who were candidate for CRT implantation and were in sinus rhythm. Patients re-evaluated by echocardiography after 6 months post CRT implantation. Results: The mean age of the patients was 63 ± 13 years and 17 (68) were males. The mean LVEF was 19.4 ± 7.4 and 24.2 ± 11.5 before and after CRT implantation respectively. Median of the duration of the R loop before the R maximum demonstrated a negative correlation with the increase in LVEF, (r = �0.36, P = 0.07) and mean of maximal spatial velocity of the T-loop for all measured showed a positive correlation (r = 0.39, p = 0.04). Other parameters didn't show any significant differences. Conclusions: Three-dimensional vectorcardiogram parameters can be helpful to predict the CRT response. Shorter duration of the R loop before the maximum R and smaller R loop area are predictors for responder patients. © 201

Cardiogoniometry can predict positive response to cardiac resynchronization therapy � A proof of concept study

Background: According to American Heart Association guidelines, QRS duration and morphology are used to select patients for cardiac resynchronization therapy (CRT). But still there are some patients who are not responding to this device. We investigated whether the Cardiogoniometry (CGM) as a three-dimensional vectorcardiogram method can improve patient selection. Methods: Echocardiography and CGM were performed for 25 consecutive patients with Left bundle branch morphology who were candidate for CRT implantation and were in sinus rhythm. Patients re-evaluated by echocardiography after 6 months post CRT implantation. Results: The mean age of the patients was 63 ± 13 years and 17 (68) were males. The mean LVEF was 19.4 ± 7.4 and 24.2 ± 11.5 before and after CRT implantation respectively. Median of the duration of the R loop before the R maximum demonstrated a negative correlation with the increase in LVEF, (r = �0.36, P = 0.07) and mean of maximal spatial velocity of the T-loop for all measured showed a positive correlation (r = 0.39, p = 0.04). Other parameters didn't show any significant differences. Conclusions: Three-dimensional vectorcardiogram parameters can be helpful to predict the CRT response. Shorter duration of the R loop before the maximum R and smaller R loop area are predictors for responder patients. © 201

Vat polymerization 3D printing of composite acrylate photopolymer-based coated glass beads

Vat photopolymerization-based three-dimensional (3D) printing techniques have been used as an efficient method for complex and special geometries in various applications. Composites are also a group of polymer materials that are obtained by adding a reinforcing component such as filler, fibres with different origins. Therefore, the development of 3D printable composites is paramount due to their high precision and speed of production. Glass beads (GBs) have been favorites as economical reinforcement agents for their chemical stability, water resistance in acidic environments, dimensional stability, and eco-friendly properties. In this study, 3D printable composites based on coated glass beads (CGBs) have been prepared. First, the beads are coated with ultraviolet (UV) curable resins to improve the interface with the polymer matrix. Then, CGBs are mixed with 3D printing resin and formulated for digital light processing (DLP) printing. The coating process is checked by scanning electron microscopy (SEM), and the mechanical properties of the 3D-printed composite structures have been evaluated by bending and compression tests. Also, the fracture behavior of cured resin has been checked with SEM. Mechanical property investigations have shown the success of the 3D printing of the CGBs into a photopolymer resin (PR) composite with behavior modification and compatibility of the interface with the matrix in practice

Can prodromal symptoms predict recurrence of vasovagal syncope?

Background: Vasovagal syncope (VVS) is a common symptom with empirical therapy and high recurrence rate. Our goal was to determine whether the pattern of presyncopal prodromal symptoms can predict the recurrence probability of vasovagal syncope. Methods: Seventy-nine consecutive patients (male/female: 53/26) with history of VVS and positive tilt table test (TTT) were enrolled in the study and completed the follow-up time for one year. They all had normal electrocardiograms and cardiac echocardiography without underlying disease. All of them were evaluated meticulously for prodromal symptoms (diaphoresis, nausea, palpitation and blurred vision) and frequency of syncopal spells in their past medical history. They received metoprolol at maximum tolerated dose and were taught tilt training as an empirical therapy after TTT. Results: Fifty-four patients (68.4) reported at least one of the four main prodromal symptoms. Median syncopal ± presyncopal spells were 4 episodes. Forty-two patients (53.2) experienced recurrence of syncope or presyncope during the follow-up period. In recurrent symptomatic patients, diaphoresis had been more significantly reported in their past medical history (p = 0.018) and they had more syncopal spells before TTT (p = 0.001). Age, gender and type of TTT response did not have any effect on the recurrence of VVS. Conclusions: Patients with a history of diaphoresis as a prodromal symptom and more pre-tilt syncopal attacks experience more syncopal or presyncopal spells during follow-up. Copyright © 2008 Via Medica