Rotational Shift Research Articles

Rotational feeding combined with shift feeding in the electrochemical trepanning of a blisk

The structure of the blades on a blisk is generally characterized by spatial distortion and spatial bending. Electrochemical trepanning (ECTr) is an effective roughing method in blisk manufacturing. To improve the structural characteristics and the allowance distribution uniformity manufactured by ECTr, a new feeding strategy, in which the relative motion of the cathode and the workpiece is due to simultaneous rotational feeding (RF) and shift feeding (SF), is proposed. The approach is called the rotational feeding combined with shift feeding (RF-SF) strategy. A parametric model and an optimized method for calculating the feeding trajectory (FT) under the RF-SF strategy are presented. To assess the effectiveness of the proposed method, the FTs for a twisted blade with variable cross section and a degree of bending were calculated and simulated for the RF and RF-SF strategies. Compared with the RF strategy, the uniformity of the allowance distribution under the RF-SF strategy was improved by 60.4% and 50.3% at the concave and convex parts, respectively. A blade was machined with RF-SF ECTr. The deviations between the experimental and simulated results were 7.1% and 8.1%, respectively, thereby verifying the effectiveness of the proposed method.

A Cross-Sectional, Exploratory Study on the Impact of Night Shift Work on Midwives' Reproductive and Sexual Health.

Background: Shift work is the basis for health care system functioning. The non-standard schedules enforce abrupt changes in the timing of sleep and light-dark exposure. It can contribute to the increased risk of various medical conditions, including reproductive and sexual health issues. The purpose of the study was to assess the impact of shift work with night shifts on midwives’ reproductive and sexual health. Methods: This cross-sectional, exploratory study included 520 midwives. A descriptive questionnaire was distributed in person (414) and online (106) from July 2019 to May 2020. We used the Female Sexual Function Index (PL-FSFI) standardized questionnaire and proprietary research tools (applicable to demographic and social data and reproductive health). All statistical calculations were performed with the IBM SPSS 23 statistical package. Results: Shift work affects midwives’ reproductive and sexual health. Midwives working night shifts are more likely to experience reproductive problems and sexual dysfunctions. The most pronounced differences are observed in the experience of infertility and the number of miscarriages. PL-FSFI results clearly showed the adverse impact of working shifts including night shifts on functioning in various dimensions of sexual health. Conclusion: Shift work negatively affects reproductive and sexual health and causes work-life conflict experience. It is necessary to develop procedures that minimize shift rotation and implement work schedules that allow for recuperation or rest and ensure proper family and social life.

Rotational Doppler effect on reflection upon an ideal rotating propeller

The rotational Doppler shift is the counterpart of the usual linear Doppler effect for rotating bodies. We study by an experimental approach coupled with theoretical considerations the rotational shift of a fundamental laser light reflected on an ideal rotating propeller. We decompose the reflected light on a Laguerre–Gaussian basis and show that only modes having the same rotational symmetry as the propeller are involved in the decomposition. The latter experience a frequency shift proportional to the rotation frequency of the propeller and the topological charge of the beam. Extensions of this work in the microwave domain are then considered.

Rotational Doppler Effect in Vortex Light and Its Applications for Detection of the Rotational Motion

The linear Doppler effect has been widely used to detect the translational motion of objects. However, it suffers difficulties in measuring the angular motion of a rotating target. In recent years, the rotational Doppler effect based on a vortex beam has been helpful to solve the problem of rotational measurement and has attracted extensive attention in remote sensing. This paper expounds the theoretical and experimental basis of the rotational Doppler effect and briefly summarizes its development for the detection of macro and micro targets. Specifically, the properties and analysis methods of a rotational Doppler shift when the vortex beam is misaligned with the rotation axis are described in detail. In addition, the existing problems and further developments in rotation detection based on the rotational Doppler effect are discussed.

Perceived Family Function and Associated Predictors in Nurses: A Cross-Sectional Study.

BackgroundNurses play a key role in the health care system. However, clinical nurses experience different kinds of stressors that might impact the nurses' quality of life or quality of care. Family is one of the main social support resources, and quality family function might improve the quality of care provided by nurses. However, evidence on family function in Chinese clinical nurses is quite limited.ObjectivesThe current study was to evaluate the family function of the Chinese clinical nurses, and to explore associated predicting factors.MethodsA multi-center cross-sectional anonymous online survey was carried out. Chinese Family Function Scale was used in the study. Spearman's rank correlation analysis, Mann-Whitney U test, or Kruskal-Wallis H test was performed in the univariate analysis. The pairwise comparison method was used to determine whether the difference was significant between pair groups. Categorical regression (optimal scaling regression) was the main method to analyze factors that had been confirmed to be statistically significant in the univariate analysis.ResultsNineteen thousand four hundred and twenty-two nurses completed the online questionnaires. The median of the nurse's perceived family function score was three (Inter-quartile Range: IQR 2–5). The multivariate analysis showed that the highest education level (P <0.001), the hospital level (P <0 .001), rotation shift status (P <0.001), working department (P < 0.001), number of children (P < 0.001), monthly income per family member (P < 0.001) were significantly associated with family function. Moreover, the importance of the factors was the number of children (49.1%), monthly income per family member (20.7%), rotation shift status (12.4%), the highest education level (8.0%), the hospital level (7.6%), and working department (2.4%) in turn.ConclusionsThe family function was associated with multiple factors, which hints that managers, leaders, and government could make strategies to improve nurses' family function in order to lead nurses to make a balance between family and work. Policymakers, nursing managers, and employers should make strategies such as promoting children-care services, increasing nurses' income, educating and training enough nurses, and building a well-established system of career development to help clinical nurses improve their family function so that to improve the quality of care.

Observation of decay of nonadiabatic molecular unidirectional rotation via time-resolved rotational Doppler spectroscopy

In order to investigate the decay of nonadiabatic molecular unidirectional rotation (UDR) for nitrogen molecules, we measured the time-resolved rotational Doppler spectroscopy in first four revival periods after instantaneous excitation by a polarization shaped femtosecond laser. The results show that the rotational Doppler shifts decrease with increasing order of revival periods for full and half rotational revivals. Moreover, the maximum alignment of the molecular UDR at half rotational revivals was demonstrated to delay with revival periods increasing. This work is helpful to understand the kinetic processes of collisional decay for nonadiabatic molecular UDR, especially in the several revival periods after excitation.

Burnout syndrome among healthcare workers during COVID-19 Pandemic in Accra, Ghana.

The emergence of the corona virus disease 2019 (COVID-19) has increased the workload of health workers particularly those in sub-Saharan Africa predisposing them to extra job-related stress and its associated job-related burnout. Burnout reduces the number, distribution and productivity of health workers. This study sought to determine personal and job-related characteristics of health workers in Accra, Ghana that influenced their experience of burnout during the COVID-19 pandemic. A cross-sectional study was conducted among 1,264 health workers recruited from three public hospitals in Accra, Ghana between March to November, 2020. The participants were recruited using a proportionate stratified sampling technique and completed a pre-tested questionnaire that collected information on socio-demographic and job-related factors. Also, the questionnaire assessed participants' level of resilience and job-related burnout. Pearson's chi-square test was used to determine the association between burnout and the socio-demographic as well as job-related factors. However, for variables with observations less than six, a Fisher's exact test, was used to determine the associations. After the binary analysis, multivariate logistic regressions were used to determine the strength of association between the socio-demographic as well as job-related factors and burnout. Data analyses were conducted at a significant level (alpha 0.05) and power of 95% confidence with the aid of Stata 15.0. The prevalence of burnout among the participants was 20.57% with non-clinicians displaying higher burnout compared to clinicians (26.74&% v 15.64%, p< 0.001). Health workers with 1-5 years working experience were 26.81 more likely to experience burnout (AOR = 26.81, CI = 6.37-112.9). Night shifts defined as shifts between 8:00pm to 8:00am was associated with the 1.86 odds of experiencing burnout (OR = 1.86; 95% CI: 1.33-2.61; p<0.001). Also, participants of the primary level facility were 3.91 times more likely (AOR = 3.91, 95% CI = 2.39-6.41) to experience burnout on the job. Similarly, participants with additional jobs were 1.14 times more likely (AOR = 1.14, 95% CI = 0.75-1.74) to experience burnout. In addition, participants harboring intentions of leaving their current jobs were 4.61 times more likely (AOR = 4.61, 95% CI = 2.73-7.78) to experience burnout. Furthermore, participants with perceived high workload were 2.38 times more likely (AOR = 2.38, 95% CI = 1.40-4.05) to experience burnt-out on the job. There is high prevalence of burnout among health workers in Accra particularly during the onslaught of the COVID-19 pandemic. Working on night shifts and at the primary level of healthcare is significantly associated with increased odds of experiencing burnout.We recommend shift rotation for staff and adequate resource provision for primary level hospitals. The high burnout in this study could be influenced by other factors such as the grief caused by multiple losses and also the limited supportive resources for health workers.

Orbital angular momentum-based dual-comb interferometer for ranging and rotation sensing.

We present a dual-comb interferometer capable of measuring both the range to a target as well as the target's transverse rotation rate. Measurement of the transverse rotation of the target is achieved by preparing the probe comb with orbital angular momentum and measuring the resultant phase shift between interferograms, which arises from the rotational Doppler shift. The distance to the target is measured simultaneously by measuring the time-of-flight delay between the target and reference interferogram centerbursts. With 40 ms of averaging, we measure rotation rates up to 313 Hz with a precision reaching 1 Hz. Distances are measured with an ambiguity range of 75 cm and with a precision of 5.9 µm for rotating targets and 400 nm for a static target. This is the first dual-comb ranging system capable of measuring transverse rotation of a target. This technique has many potential terrestrial and space-based applications for lidar and remote sensing systems.

Nurses' perceptions of hourly rounding in Jordanian hospitals: A national survey.

This study aims to explore nurses' perceptions of hourly rounding in Jordanian hospitals. Hourly rounding is a standardized and systematic process conducted by nurses to anticipate and address needs in hospitalized patients. The evidence on hourly rounding is mixed, and research is needed to affirm the benefits of implementing hourly rounding across different contexts. A cross-sectional correlational design was used. A convenient sample of 1378 nurses was recruited from one military hospital, two university-affiliated hospitals, four governmental hospitals and four private hospitals in Jordan. The Hourly Rounding Questionnaire was used to collect data. Descriptive statistics, t test, one-way ANOVA and Kruskal-Wallis H test were used to analyse the data. The highest agreements between nurses were on the items related to the implementation of hourly rounding in terms of 'preventing patient falls' 1211 (87.9%), 'preventing hospital-acquired pressure ulcers' 1201 (87.2%) and 'addressing patients' position' 1199 (87%). The lowest agreements between nurses were on the items related to the involvement of nurses in the decision-making process and sense of ownership 268 (19.4%) and the availability of continued support and resources 239 (17.3%). Female nurses, nurses who often work on a shift rotation, nurses working in private hospitals and respiratory units had a positive perception of hourly rounding. Findings will inform nursing leaders and policy developers about the implementation of hourly rounding from nurses' perspectives. A protocol should accompany hourly rounding for robust evaluation to measure the impact of this process change with the involvement of nurses in the decision-making process.

Rotational object detection at noncoaxial light incidence based on the rotational Doppler effect.

The rotational Doppler effect (RDE) of optical vortex which can be used to detect the rotation speed, has become a well-known phenomenon and a hot topic of research in recent years. However, because the beam axis must be coaxial with the rotational axis of the object, it can only be used to detect cooperative targets in practical application. Here, we provide a novel approach for measuring rotational speed under light non-coaxial incidence relative to the rotating axis that uses the adjacent frequency difference of rotational Doppler shift signals. Theoretically, the rotational Doppler shift is proportional to the OAM mode of the incident beam, and the nature of the OAM carried by each photon is a discrete or quantized quantity under off-axis conditions leading to the discrete distribution of the Doppler shift signals. Experimentally, by extracting the difference between two adjacent Doppler shift signals, the rotating speed of the object can be determined. Based on our method, the rotational speed of the object can be measured precisely without the pre-known information about the position of the rotating axis. Our work supplies a significant complement to the conventional RDE theory and we believe it may promote the realistic application of the optical RDE-based metrology.

Real-time monitoring the hydrolysis of chiral molecules by optical weak measurement

As one of important optical properties of chiral molecules, the real-time monitoring of the optical rotation is of great significance to study the reaction characteristics of chiral molecules. In this study, we have built an optical frequency domain weak measurement system with linear common-path method for chiral sensing, in which the response between optical rotation and central wavelength shift can reach more than 1200 nm/rad. The high-precision measurement of the optical rotation of chiral molecules and the high-sensitivity real-time monitoring of the decomposition rate in the acidic hydrolysis of sucrose under different concentrations of catalysts are realized using this system. The experimental results are basically consistent with the theoretical prediction. This study shows that optical weak measurement chiral sensing can monitor the hydrolysis degree of chiral molecules in real time without separating and labeling molecules. It has great application potential in the production and research of chiral compounds, especially chiral medicine.

Calculation of set-up margin in frameless stereotactic radiotherapy accounting for translational and rotational patient positing error.

Rotation corrected set-up margins in stereotactic radiotherapy (SRT). This study aimed to calculate the rotational positional error corrected set-up margin in frameless SRT. 6D setup errors for the steriotactic radiotherapy patients were converted to 3D translational only error mathematically. Setup margins were calculated with and without considering the rotational error and compared. A total of 79 patients of SRT each received >1 fraction (3-6 fractions) incorporated in this study. Two cone-beam computed tomography (CBCT) scans were acquired for each session of treatment, before and after the robotic couch-aided patient position correction using a CBCT. The postpositional correction set-up margin was calculated using the van Herk formula. Further, a planning target volume_R (PTV_R) (with rotational correction) and PTV_NR (without rotational correction) were calculated by applying the rotation corrected and uncorrected set-up margins on the gross tumor volumes (GTVs). Statistical Analysis Used: General. A total of 380 sessions of pre- (190) and post (190) table positional correction CBCT was analyzed. Posttable position correction mean positional error for lateral, longitudinal, and vertical translational and rotational shifts was (x)-0.01 ± 0.05 cm, (y)-0.02 ± 0.05 cm, (z) 0.00 ± 0.05 cm, and (θ) 0.04° ± 0.3°, (Φ) 0.1° ± 0.4°, (Ψ) 0.0° ± 0.4°, respectively. The GTV volumes show a range of 0.13 cc-39.56 cc, with a mean volume of 6.35 ± 8.65 cc. Rotational correction incorporated postpositional correction set-up margin the in lateral (x), longitudinal (y) and vertical (z) directions were 0.05 cm, 0.12 cm, and 0.1 cm, respectively. PTV_R ranges from 0.27 cc to 44.7 cc, with a mean volume of 7.7 ± 9.8 cc. PTV_NR ranges from 0.32 cc to 46.0 cc, with a mean volume of 8.1 ± 10.1 cc. The postcorrection linear set-up margin matches well with the conventional set-up margin of 1 mm. Beyond a GTV radius of 2 cm, the difference between PTV_NR and PTV_R is ≤2.5%, hence not significant.

Fluid vortex mapping using the rotational Doppler effect

The light from a twisted laser beam, scattered at an air/water interface, experiences a rotational Doppler shift. We use a superposition of two beams with different topological charges to measure the beat frequency of the scattered light by a Rankine type vortex at different positions from its center. We show that the angular velocity decreases with the distance in total agreement with a Rankine vortex model. Several extensions are then considered, including the detection of turbulences generated in the wake of airplanes.

Locating the center of rotation of a planar object using an optical vortex.

The rotational Doppler effect (RDE) of optical vortex beams provides an efficient way to measure the rotational frequency of objects based on rotational Doppler frequency shifts, while the frequency shift signals display a distinct broadening effect when the vortex beam is laterally misaligned with the center of rotation of a planar object. We use a modal decomposition method to reveal the broadening effect and obtain a linear fitting equation between the quantity of signals and lateral misalignments. In an experiment of RDE, the lateral misalignment is extracted from the quantity of signal peaks. The fitting equation is proved to be precise within the uncertainty of ±0.17mm (±2.8% of the vortex beam radius), and the center of rotation is located with an error less than 3.33% of the beam radius. Our work provides a new approach to locate the center of rotation of noncooperative objects, which may be valuable in mechanical manufacturing and optical noncontact metrology.

Association of Circadian Rhythm, Daytime Sleepiness, and Fatigue According to the Type of Shift Work among Nurses Working at a Tertiary Teaching Hospital

Purpose: The purpose of this study was to examine the level of circadian rhythm, daytime sleepiness, and fatigue andtheir associations by type of shift work among nurses working at a tertiary teaching hospital. Methods: This study was across-sectional descriptive study. A total of 263 nurses were used as subjects. Using a structured survey, circadianrhythm, daytime sleepiness, and fatigue were assessed. Data were analyzed using Statistical Package For The SocialSciences (SPSS) version 26.0. Descriptive statistics were computed to explain sample and variable characteristics. Chi-squared test and independent t-test were used to compare the variables by general characteristics. Pearson’s corre lation coefficients were computed to examine the association between circadian rhythm, daytime sleepiness, and fatigue. Results: The average age of the participants was 27.35±3.99 years old for shift work and 39.63±8.99 years old fornon-shift work. In the circadian rhythm, most non-shift workers were intermediate type (83.3%), but approximatelyone-third of shift workers were evening type (31.0%). Fatigue was significantly higher in shift workers than in non-shiftworkers (t=2.26, p=.024). Fatigue in non-shift workers was significantly associated with circadian rhythm and daytimesleepiness (r=-.35, p=.005; r=.35, p=.006, respectively). However, fatigue in shift workers was only significantly asso ciated with daytime sleepiness (r=.28, p<.001). Conclusion: These findings indicate that customized strategies should beprepared to reduce nurses’ fatigue considering the type of work shift rotation. Nursing administrators need to considernurses’ circadian rhythm before the decision on shift work to expect better nursing outcomes.

Reducing ExacTrac intrafraction imaging uncertainty for prostate stereotactic body radiotherapy using a pre-treatment CBCT.

This study evaluated the intrafractional auto-matching uncertainties of prostate-implanted fiducial markers when using the ExacTrac v6.5 (Brainlab, Feldkirchen, Germany) X-ray stereoscopic system. A customised phantom with 3 implanted gold seeds was initially positioned at the isocentre using a cone beam CT (CBCT) prior to intrafractional imaging. Progressive offsets were applied to the phantom in all six directions (3 translational, 3 rotational) of 0mm, 1mm, 2mm, 0°, 1° and 2°. Subsequently, the ability of the ExacTrac image-matching functions to detect and correct these offsets was tested. For comparison, this procedure was repeated, but without a CBCT for pre-treatment positioning. The auto-matching uncertainties when a CBCT was introduced into the workflow were significantly reduced, and overall, the auto-matching statistics using the implanted marker (seeds) matching function was found to be more precise than the bony anatomy function in-phantom. The total standard deviations for the translational shifts using the implanted marker and bony anatomy functions respectively were 0.1mm and 0.3mm vertically, 0.1mm and 0.3mm longitudinally, and 0.1mm and 0.4mm laterally. The standard deviations for the rotational shifts using the implanted marker and bony anatomy matching functions respectively were 0.2° and 1.2° for the yaw (angle vert), 0.3° and 1.1° for the pitch (angle long), and 0.2° and 1.2° for the roll (angle lat) directions. The reduced uncertainties from introducing a CBCT for initial localisation resulted in decreased probability of inhibits due to false positives during treatment.

The impact of police–community relations: Recruitment and retention concerns of local police agencies

Abstract Recently, there has been a growing movement across the USA to defund police. Additionally, police agencies have faced a rapidly declining application pool. Fewer applicants combined with retention issues have led to staffing concerns and cultural impacts within departments. This study examines the recruitment and retention problems faced by a local police agency in response to struggles within police–community relations and calls to defund police nationwide. Three series of interviews were conducted among new hires in training, new hires post training, and voluntary departures. Findings from this study indicate three primary categories of themes effecting both recruitment and retention: support, operational standards and compensation, and transparency. Based on the findings, several policy implications should be considered to improve recruitment and retention within the department. These include developing a comprehensive website for candidates and current officers, adjusting personnel shift rotation, overhauling the Field Training Programme, and working to improve support.

Robust and High-Performance Machine Vision System for Automatic Quality Inspection in Assembly Processes.

This paper addresses the problem of automatic quality inspection in assembly processes by discussing the design of a computer vision system realized by means of a heterogeneous multiprocessor system-on-chip. Such an approach was applied to a real catalytic converter assembly process, to detect planar, translational, and rotational shifts of the flanges welded on the central body. The manufacturing line imposed tight time and room constraints. The image processing method and the features extraction algorithm, based on a specific geometrical model, are described and validated. The algorithm was developed to be highly modular, thus suitable to be implemented by adopting a hardware–software co-design strategy. The most timing consuming computational steps were identified and then implemented by dedicated hardware accelerators. The entire system was implemented on a Xilinx Zynq heterogeneous system-on-chip by using a hardware–software (HW–SW) co-design approach. The system is able to detect planar and rotational shifts of welded flanges, with respect to the ideal positions, with a maximum error lower than one millimeter and one sexagesimal degree, respectively. Remarkably, the proposed HW–SW approach achieves a 23× speed-up compared to the pure software solution running on the Zynq embedded processing system. Therefore, it allows an in-line automatic quality inspection to be performed without affecting the production time of the existing manufacturing process.

Moderate-intensity aerobic exercise as an adjunct intervention to improve sleep quality among rotating shift nurses.

Nurses working rotating shifts (RS) are at risk of circadian rhythm disruption, which can affect sleep quality and can lead to emotional stress, anxiety, and depression. Aerobic exercise is a type of repetitive and structured physical activity that involves the metabolic system, which utilizes oxygen to produce energy and has been demonstrated to improve shift-workers' health and well-being. The main purpose of engaging in regular moderate-intensity aerobic exercise is to improve cardiopulmonary fitness and functional capacity. When engaging in moderate-intensity aerobic exercise, the increase in arterial pressure is accompanied by a simultaneous increase in heart rate, which signifi-cantly contributes to the rise in blood pressure, which is reversed after exercise due to an increase in parasympathetic activity and a decrease in sympathetic activity. Moderate-intensity aerobic exercise includes walking at a moderate pace, water aerobics, dancing, recreational swimming, gardening, table tennis, and stair climbing at a moderate pace and represents a cost-effective health promotion strategy for im-proving sleep quality and duration. Adherence to a moderate-intensity aerobic exercise program may increase both sleep quality and duration by improving melatonin concentrations, endocrine activities, heart rate and slow wave sleep among nurses working RS. Occupational medicine practitioners should consider creating a workplace health promotion program that incorporates moderate-intensity aerobic exercise for RS-nurses to minimize the impact of shift work on their sleep quality.

Experimental and numerical study of the rotational Doppler shift in acoustic waves using static microphones

The rotational Doppler shift in acoustic waves carrying orbital angular momentum (OAM) has been applied in experiments to demonstrate the Zel'dovich amplification, which is analogously linked with the black hole radiance. However, rotating microphones used in the published experiments are difficult to assemble and intrinsically weak in the frequency response at frequencies around 0 Hz. To circumvent the limitations, this paper proposes an experimental method to study the rotational Doppler shift in acoustic OAM waves using static microphones. The Doppler shifted signals viewed by a rotating observer were extracted from the original acoustic signals at frequencies around 100 Hz, where the microphones had flat frequency response. The measured results not only demonstrated the extreme Doppler shift to a negative frequency but also showed that the acoustic amplitudes were very low when the Doppler shifted frequency was 0 Hz. This phenomenon was explained by showing in a time-domain numerical simulation that the wave was co-rotating with the observer. In addition, the characteristics of the simulated pressure contours of the rotating wave have been discussed. The proposed methods can further be used to study the physics related to the wave carrying OAM, such as the acoustic super-radiance.