Velocity is probably the most important parameter in manufacturing, influencing performance, cost, productivity, energy and resources efficiency as well as safety and environmental issues. This paper ...presents basic phenomena as well as other important effects which are linked to velocity as a process parameter. In addition, applications, for example superplastic forming or high speed cutting, which have been founded on uncommon process velocities are discussed in the context of technological developments which have taken place over the past several years.
Sheet metal forming at elevated temperatures Neugebauer, R.; Altan, T.; Geiger, M. ...
CIRP annals,
2006, 2006-00-00, Letnik:
55, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
Due to the need to significantly reduce the part weights in automotive manufacturing, the use of lightweight materials becomes ever more important. Unfortunately, these materials are often associated ...with a limited cold formability. Due to this fact, production of large, complex sheet metal components using forming technology frequently entails increased expenditures. Moreover, processing high-strength materials requires correspondingly high processing forces and pressures. In order to find a solution to counter the disadvantages mentioned above, the use of elevated temperatures as a process parameter in forming operations represents a potential solution approach. The following paper will give an overview about research activities in the field of forming operations at elevated temperatures.
Mechatronic Systems for Machine Tools Neugebauer, R.; Denkena, B.; Wegener, K.
CIRP annals,
2007, 2007-00-00, Letnik:
56, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
This paper reviews current developments in mechatronic systems for metal cutting and forming machine tools. The integration of mechatronic modules to the machine tool and their interaction with ...manufacturing processes are presented. Sample mechatronic components for precision positioning and compensation of static, dynamic and thermal errors are presented as examples. The effect of modular integration of mechatronic system on the reconfigurability and reliability of the machine tools is discussed along with intervention strategies during machine tool operation. The performance and functionality aspects are discussed through active and passive intervention methods. A special emphasis was placed on active and passive damping of vibrations through piezo, magnetic and electro-hydraulic actuators. The modular integration of mechatronic components to the machine tool structure, electronic unit and CNC software system is presented. The paper concludes with the current research challenges required to expand the application of mechatronics in machine tools and manufacturing systems.
Aims
To evaluate the effectiveness of automated symptom and side effect monitoring on quality of life among individuals with symptomatic diabetic peripheral neuropathy.
Methods
We conducted a ...pragmatic, cluster randomized controlled trial (July 2014 to July 2016) within a large healthcare system. We randomized 1834 primary care physicians and prospectively recruited from their lists 1270 individuals with neuropathy who were newly prescribed medications for their symptoms. Intervention participants received automated telephone‐based symptom and side effect monitoring with physician feedback over 6 months. The control group received usual care plus three non‐interactive diabetes educational calls. Our primary outcomes were quality of life (EQ‐5D) and select symptoms (e.g. pain) measured 4–8 weeks after starting medication and again 8 months after baseline. Process outcomes included receiving a clinically effective dose and communication between individuals with neuropathy and their primary care provider over 12 months. Interviewers collecting outcome data were blinded to intervention assignment.
Results
Some 1252 participants completed the baseline measures mean age (sd): 67 (11.7), 53% female, 57% white, 8% Asian, 13% black, 20% Hispanic. In total, 1179 participants (93%) completed follow‐up (619 control, 560 intervention). Quality of life scores (intervention: 0.658 ± 0.094; control: 0.653 ± 0.092) and symptom severity were similar at baseline. The intervention had no effect on primary EQ‐5D: −0.002 (95% CI −0.01, 0.01), P = 0.623; pain: 0.295 (−0.75, 1.34), P = 0.579; sleep disruption: 0.342 (−0.18, 0.86), P = 0.196; lower extremity functioning: −0.079 (−1.27, 1.11), P = 0.896; depression: −0.462 (−1.24, 0.32); P = 0.247 or process outcomes.
Conclusions
Automated telephone monitoring and feedback alone were not effective at improving quality of life or symptoms for people with symptomatic diabetic peripheral neuropathy.
Trial Registration: ClinicalTrials.gov (NCT02056431).
What's new?
Frequent communication between individuals with diabetic peripheral neuropathy and primary care providers about symptoms and medication side effects is critical to optimizing medication dosing to treat painful diabetic peripheral neuropathy. Yet, there are considerable barriers to effective communication.
This cluster randomized controlled trial found that a brief intervention to automatically monitor person‐reported data on symptoms and side effects, and provide the information to physicians via an electronic health record was not effective in improving the outcomes valued by individuals with neuropathy.
Alerts alone are unlikely to change provider behaviour related to treatment intensification. More intensive interventions focused on individual activation or provider education may be more effective in changing prescribing behaviour and improving outcomes.
Parallel kinematic machines exhibit strong position-dependent dynamic behavior, which changes the stability and the productive cutting conditions within the machine work volume. In this paper, ...position-dependency of a hybrid serial-parallel scissor kinematic machine is modeled by synthesizing its substructural reduced order finite element models. The model allows the efficient investigation of position-dependency as an alternative to using time consuming full order finite element models. The predicted position dependency of the machine with the reduced order model is experimentally validated. Stability maps are simulated as a function of machine positions to identify the productivity levels within the machine work volume.
Advances in mechanical joining of magnesium Neugebauer, R.; Kraus, C.; Dietrich, S.
CIRP annals,
2008, 2008-00-00, Letnik:
57, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The application of conventional mechanical joining methods for joining magnesium parts is restricted by the limited formability of magnesium at room temperature. Dieless clinching is a new clinching ...method that works with a flat anvil as a counter tool, thus offering important benefits for the joining of magnesium. It is possible to decrease the heating time to 1
s or less, instead of 3–6
s with conventional clinching methods. This article discusses the mechanism and limits to possible heating time reduction and introduces new findings on the impact of adhesives between parts.
Interpersonal psychotherapy (IPT) is a time-limited psychotherapy for major depression. The aim of this study is to summarize findings from controlled trials of the efficacy of IPT in the treatment ...of depressive spectrum disorders (DSD) using a meta-analytic approach.
Studies of randomized clinical trials of IPT efficacy were located by searching all available data bases from 1974 to 2002. The searches employed the following MeSH categories: Depression/ Depressive Disorder; Interpersonal therapy; Outcome/Adverse Effects/Efficacy; in the identified studies. The efficacy outcomes were: remission; clinical improvement; the difference in depressive symptoms between the two arms of the trial at endpoint, and no recurrence. Drop out rates were used as an index of treatment acceptability.
Thirteen studies fulfilled inclusion criteria and four meta-analyses were performed. IPT was superior in efficacy to placebo in nine studies (Weight Mean Difference (WMD) - 3.57 -5.9, -1.16). The combination of IPT and medication did not show an adjunctive effect compared to medication alone for acute treatment (RR 0.78 0.30, 2.04), for maintenance treatment (RR 1.01 0.81, 1.25), or for prophylactic treatment (RR 0.70 0.30, 1.65). IPT was significantly better than CBT (WMD -2.16 -4.16,-0.15).
The efficacy of IPT proved to be superior to placebo, similar to medication and did not increase when combined with medication. Overall, IPT was more efficacious than CBT. Current evidence indicates that IPT is an efficacious psychotherapy for DSD and may be superior to some other manualized psychotherapies.
Incremental bulk forming is the oldest known technique in metal working. Many developments in this field have dramatically changed our society. Today incremental bulk forming processes are applied to ...quality products in small and large series production. Numerous advances have been realized. The motivation for using these processes is presented here. After a general definition of incremental processes and a classification of incremental bulk forming in particular, some innovative product and process examples are given that show the potential. Finally recent progress and challenges are illustrated in detail. This includes the development of new machinery for incremental bulk forming, advanced methods for process planning, occurrence of failure modes and the properties of finished products.
Summary
Contemporary femur fracture rates were examined in northern California women and compared by race/ethnicity. During 2006–2012, hip fracture rates declined, but diaphyseal fracture rates ...increased, especially in Asians. Women with diaphyseal fracture were younger and more likely to be bisphosphonate-treated. These disparities in femur fracture should be further examined.
Introduction
The epidemiology of diaphyseal femur fracture differs from proximal femur (hip) fracture, although few studies have examined demographic variations in the current era. This study examines contemporary differences in low-energy femur fracture by race/ethnicity in a large, diverse integrated health-care delivery system.
Methods
The incidence of hip and diaphyseal fracture in northern California women aged ≥50 years old during 2006–2012 was examined. Hip (femoral neck and pertrochanteric) fractures were classified by hospital diagnosis codes, while diaphyseal (subtrochanteric and femoral shaft) fractures were further adjudicated based on radiologic findings. Demographic and clinical data were obtained from health plan databases. Fracture incidence was examined over time and by race/ethnicity.
Results
There were 10,648 (97.3 %) hip and 300 (2.7 %) diaphyseal fractures among 10,493 women. The age-adjusted incidence of hip fracture fell from 281 to 240 per 100,000 women and was highest for white women. However, diaphyseal fracture rates increased over time, with a significant upward trend in Asians (9 to 27 per 100,000) who also had the highest rate of diaphyseal fracture. Women with diaphyseal fracture were younger than women with hip fracture, more likely to be of Asian race and to have received bisphosphonate drugs. Women with longer bisphosphonate treatment duration were also more likely to have a diaphyseal fracture, especially younger Asian women.
Conclusion
During 2006 to 2012, hip fracture rates declined, but diaphyseal fracture rates increased, particularly among Asian women. The association of diaphyseal fracture and bisphosphonate therapy should be further investigated with examination of fracture pattern.
Abstract To provide a close-to-reality simulation model, such as for improved surgery planning, this model has to be experimentally verified. The present article describes the use of a 3D laser ...vibrometer for determining modal parameters of human pelvic bones that can be used for verifying a finite elements model. Compared to previously used sensors, such as acceleration sensors or strain gauges, the laser vibrometric procedure used here is a non-contact and non-interacting measuring method that allows a high density of measuring points and measurement in a global coordinate system. Relevant modal parameters were extracted from the measured data and provided for verifying the model. The use of the 3D laser vibrometer allowed the establishment of a process chain for experimental examination of the pelvic bones that was optimized with respect to time and effort involved. The transfer functions determined feature good signal quality. Furthermore, a comparison of the results obtained from pairs of pelvic bones showed that repeatable measurements can be obtained with the method used.
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