Bending stress in gear teeth for variable surface pressure distribution

AbstractThe bending stress in the root fillets of gear teeth having convex, circular-arc profiles has been calculated using a new analytic model for variable surface pressure distribution. The gear tooth is modeled as a wedge with the load applied at the apex. Graphs of the nondimensional bending stress variation along the tooth length are presented for 14.5 °, 22.5 °, and 30 ° normal pressure angle; 5 °, 25 °, and 45 ° helix angle, and 16, 32, and 80 normal diametral pitch. Tables of the nondimensional maximum root-fillet stress variation are presented for the variation of normal pressure angle, helix angle, and normal diametral pitch. It is shown that gears with larger helix angles or normal diametral pitches or lower normal pressure angles have higher bending stresses for the same value of allowalble surface stress

Applying the ARPSO Algorithm to Shafting Alignment Optimization Design

Trial-and-error method for shafting alignment at the initial design stage in the shipbuilding industry is mostly carried out by shipyard designers. However, adjusting of a highly sensitive shaft line within a short period in order to obtain a reasonable positive design value for each bearing reaction force (load) and bearing pressure for the entire propulsion shafting system is very difficult. Any minor changes in the bearing location and/or off-set design values may cause different analytical results with a large design deviation, such that the fi nal design result may not comply with the classifi cation society requirements and manufacturers’ design criteria. The innovative ARPSO-SHAALIN design program successfully combines and integrates the Three Moment Equation Method (TMEM) for a continuous beam with the Attractive and Repulsive Particle Swarm Optimization (ARPSO) algorithm. The ARPSO algorithm searches for the values of global optimal design parameter for each bearing off-set and location of the propulsion shafting in the initial design stage in order to create a brand new optimal shafting arrangement. Design results are verifi ed and presented

Applying the ARPSO Algorithm to Shafting Alignment Optimization Design

Trial-and-error method for shafting alignment at the initial design stage in the shipbuilding industry is mostly carried out by shipyard designers. However, adjusting of a highly sensitive shaft line within a short period in order to obtain a reasonable positive design value for each bearing reaction force (load) and bearing pressure for the entire propulsion shafting system is very difficult. Any minor changes in the bearing location and/or off-set design values may cause different analytical results with a large design deviation, such that the fi nal design result may not comply with the classifi cation society requirements and manufacturers’ design criteria. The innovative ARPSO-SHAALIN design program successfully combines and integrates the Three Moment Equation Method (TMEM) for a continuous beam with the Attractive and Repulsive Particle Swarm Optimization (ARPSO) algorithm. The ARPSO algorithm searches for the values of global optimal design parameter for each bearing off-set and location of the propulsion shafting in the initial design stage in order to create a brand new optimal shafting arrangement. Design results are verifi ed and presented

Predictors of psychiatric readmissions in the short- and long-term: a population-based study in taiwan

OBJECTIVES: To explore the risks and rates of readmission and their predictors 14 days, one year, and five years after discharge for the psychiatric population in Taiwan. METHODS: This was a prospective study based on claims from 44,237 first-time hospitalized psychiatric patients discharged in 2000, who were followed for up to five years after discharge. The cumulative incidence and incidence density of readmission were calculated for various follow-up periods after discharge, and Cox proportional hazard models were generated to identify the significant predictors for psychiatric readmission. RESULTS: The less than 14-day, one-year, and five-year cumulative incidences were estimated at 6.1%, 22.3%, and 37.8%, respectively. The corresponding figures for incidence density were 4.58, 1.04, and 0.69 per 1,000 person-days, respectively. Certain factors were significantly associated with increased risk of readmission irrespective of the length of follow-up, including male gender, length of hospital stay >15 days, economic poverty, a leading discharge diagnosis of schizophrenia/affective disorders, and residence in less-urbanized regions. Compared to children/adolescents, young adults (20-39 years) were significantly associated with increased risks of <one-year and <five-year readmissions, but not <14-day readmission. Additionally, hospital characteristics were significantly associated with increased risk of <14-day and <one-year readmission, but not with risk of <five-year readmission. CONCLUSIONS: This study found that the significant predictors for psychiatric readmission 14 days to five years after discharge were essentially the same except for patient's age and hospital accreditation level. This study also highlighted the importance of socioeconomic factors in the prediction of readmission

Bilateral Ureteral Leiomyoma With Bilateral Ureteropelvic Junction Obstruction

Leiomyomas are benign tumors characterized by overgrowth of visceral smooth muscle in the respiratory, gastrointestinal, and female reproductive tracts. They rarely develop in the urinary system and only 10 cases of unilateral ureteral leiomyoma (UL) have been reported since 1955. No cases of bilateral UL or ureteropelvic junction obstruction due to UL have ever been reported. We present a case of bilateral UL with bilateral ureteropelvic junction obstruction. To the best of our knowledge, this is the first such case report in the English literature

INVESTIGATING THE INFLUENCE OF AUTHORITARIAN LEADERSHIP AND SUPERVISOR SATISFACTION ON TURNOVER INTENTION: THE MODERATING ROLE OF EMPLOYEE UPBRINGING

Authoritarian leadership is prevalent in the Asian region, and previous research has found a positive correlation between authoritarian leadership and employees' intention to leave their jobs. However, there are employees in the workplace who can adapt to such supervisors. Therefore, we approach this study from the perspective of "fit theory" to explore whether employees with authoritarian family upbringing can match with authoritarian leadership. This study aims to investigate the impact of authoritarian leadership on employees' intention to leave, with supervisor satisfaction as the mediator and employees' authoritarian family upbringing as the moderator. A total of 232 valid questionnaires were collected in this study. The results revealed that the level of authoritarian family upbringing among employees has a moderating effect on the relationship between authoritarian leadership and supervisor satisfaction

Optical, Excitonic, and Electronic Properties of CH3NH3PbI3 Thin Films and Their Application in Photovoltaics

In the past two years, the highest power conversion efficiency of perovskite absorber (PA)–based photovoltaics has been 20.2%. The PA can be fabricated on flat substrates (for example, ZnO, TiO2, and PEDOT:PSS) using solution processes, which have a low-cost advantage in terms of industry production. In this report, the recent advances of PA-based photovoltaics will be mentioned. Then, the optoelectronic properties of PA, material fabrication, and photovoltaic performance will be discussed. On the other hand, we used scanning electron microscopy, two-dimensional X-ray diffractometer, and photoluminescence spectroscopy to investigate the fundamental properties of CH3NH3PbI3 thin films fabricated with and without toluene washing treatment, which provides an assessment of the development potential of PA-based photovoltaics

Hyperbaric oxygen suppressed tumor progression through the improvement of tumor hypoxia and induction of tumor apoptosis in A549-cell-transferred lung cancer

Tumor cells have long been recognized as a relative contraindication to hyperbaric oxygen treatment (HBOT) since HBOT might enhance progressive cancer growth. However, in an oxygen deficit condition, tumor cells are more progressive and can be metastatic. HBOT increasing in oxygen partial pressure may benefit tumor suppression. In this study, we investigated the effects of HBOT on solid tumors, such as lung cancer. Non-small cell human lung carcinoma A549-cell-transferred severe combined immunodeficiency mice (SCID) mice were selected as an in vivo model to detect the potential mechanism of HBOT in lung tumors. HBOT not only improved tumor hypoxia but also suppressed tumor growth in murine xenograft tumor models. Platelet endothelial cell adhesion molecule (PECAM-1/CD31) was significantly increased after HBOT. Immunostaining of cleaved caspase-3 was demonstrated and apoptotic tumor cells with nuclear debris were aggregated starting on the 14th-day after HBOT. In vitro, HBOT suppressed the growth of A549 cells in a time-dependent manner and immediately downregulated the expression of p53 protein after HBOT in A549 cells. Furthermore, HBOT-reduced p53 protein could be rescued by a proteasome degradation inhibitor, but not an autophagy inhibitor in A549 cells. Our results demonstrated that HBOT improved tissue angiogenesis, tumor hypoxia and increased tumor apoptosis to lung cancer cells in murine xenograft tumor models, through modifying the tumor hypoxic microenvironment. HBOT will merit further cancer therapy as an adjuvant treatment for solid tumors, such as lung cancer