157 research outputs found
Characterisation of the Etching Quality in Micro-Electro-Mechanical Systems by Thermal Transient Methodology
Our paper presents a non-destructive thermal transient measurement method
that is able to reveal differences even in the micron size range of MEMS
structures. Devices of the same design can have differences in their
sacrificial layers as consequence of the differences in their manufacturing
processes e.g. different etching times. We have made simulations examining how
the etching quality reflects in the thermal behaviour of devices. These
simulations predicted change in the thermal behaviour of MEMS structures having
differences in their sacrificial layers. The theory was tested with
measurements of similar MEMS devices prepared with different etching times. In
the measurements we used the T3Ster thermal transient tester equipment. The
results show that deviations in the devices, as consequence of the different
etching times, result in different temperature elevations and manifest also as
shift in time in the relevant temperature transient curves.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Comparison of Two Low-Power Electronic Interfaces for Capacitive Mems Sensors
The paper discusses the importance and the issues of interfacing capacitive
sensors. Two architectures applicable for interfacing capacitive sensors are
presented. The first solution was designed to interface a capacitive humidity
sensor designed and built for a humidity-dependent monolithic capacitor
developed at Budapest University of Technology and Economics. The second case
presents the possible read-out solutions for a SOI-MEMS accelerometer. Both of
the architectures were built and tested in a discrete implementation to qualify
the methods before the integrated realization. The paper presents a detailed
comparison of the two methodsComment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
Non-destructive structural analysis of the heat conducting path in power electronics and solid state lighting by thermal transient testing
Thermal transient testing is a tool for examining structural
details of a heat conducting path composed of heat conduction
and heat convection sections. Using the change of inherent heat
in electronics, temperature transients provide a characterisation
technique where using x-ray or acoustic microscopy would be
troublesome and time-consuming.
A complete toolkit for the accurate dynamic characterisation
of subassemblies and cooling mounts is described in the
paper. After giving the theoretical background, it is shown that
the methodology can directly generate a valid and detailed
structural equivalent from a single transient measurement.
The descriptive thermal functions such as time constants
and structure functions are demonstrated in practical examples,
the capability of the structure functions for validating cooling
concepts and detecting assembly problems is shown.
Recognising the fact that systems with multiple energy
transport such as electric energy converted to heat and light
exhibit special features; the concept of structure functions has
been modified for applications in solid state lighting.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers
Trading between perceived risks and benefits related to biosimilar biological treatment in Crohn’s disease; discrete choice experiment among gastroenterologists
Objective: The objective of the study is to explore preferences of gastroenterologists for biosimilar drugs in Crohn’s Disease and reveal trade-offs between the perceived risks and benefits related to biosimilar drugs. Method: Discrete choice experiment was carried out involving 51 Hungarian gastroenterologists in May, 2014. The following attributes were used to describe hypothetical choice sets: 1) type of the treatment (biosimilar/originator) 2) severity of disease 3) availability of continuous medicine supply 4) frequency of the efficacy check-ups. Multinomial logit model was used to differentiate between three attitude types: 1) always opting for the originator 2) willing to consider biosimilar for biological-naïve patients only 3) willing to consider biosimilar treatment for both types of patients. Conditional logit model was used to estimate the probabilities of choosing a given profile. Results: Men, senior consultants, working in IBD center and treating more patients are more likely to willing to consider biosimilar for biological-naïve patients only. Treatment type (originator/biosimilar) was the most important determinant of choice for patients already treated with biologicals, and the availability of continuous medicine supply in the case biological-naïve patients. The probabilities of choosing the biosimilar with all the benefits offered over the originator under current reimbursement conditions are 89% vs 11% for new patients, and 44% vs 56% for patients already treated with biological. Conclusions: Gastroenterologists were willing to trade between perceived risks and benefits of biosimilars. The continuous medical supply would be one of the major benefits of biosimilars. However, benefits offered in the scenarios do not compensate for the change from the originator to the biosimilar treatment of patients already treated with biologicals
A qualitative investigation of the relevance of skin irritation and self-confidence bolt-ons and their conceptual overlap with the EQ-5D in patients with psoriasis
Objectives
A number of bolt-ons have been proposed for the EQ-5D, including two psoriasis-specific bolt-ons, skin irritation and self-confidence. The study investigates and compares the relevance and comprehensiveness of these psoriasis-specific bolt-ons and the EQ-5D-5L and explores the potential conceptual overlaps between the existing five dimensions and the two bolt-ons.
Methods
Psoriasis patients were purposively sampled according to age and gender. Semi-structured interviews, where participants were asked to complete the EQ-5D-5L and the bolt-ons while thinking aloud, were conducted. Probes were used to investigate the thought processes of patients regarding the dimensions, wording, recall period and relevant concepts not captured by the EQ-5D-5L and bolt-ons. Data were analysed thematically. A focus group was used to confirm the findings.
Results
Overall, 16 patients completed the interviews. Sixteen and fifteen patients considered skin irritation and self-confidence relevant areas to describe psoriasis problems. Three patients considered itching a form of discomfort, and thus, pointed out a potential overlap between pain/discomfort and skin irritation. Twelve patients reported overall 10 general health- or psoriasis-related concepts that are not captured by the EQ-5D-5L, including itching, social relationships and sex life. Eleven patients reported that the recall period of the EQ-5D-5L might be subject to bias because of the daily or within-day fluctuations of their symptoms.
Conclusions
The skin irritation and self-confidence bolt-ons contribute to improve content validity of the EQ-5D-5L in patients with psoriasis. The qualitative approach taken in this study expands the existing methodological framework for the development and testing validity of bolt-ons for the EQ-5D
Characterization of the etching quality in micro-electro-mechanical systems by thermal transient methodology
Our paper presents a non-destructive thermal transient measurement method that is able to reveal differences even in the micron size range of MEMS structures. Devices of the same design can have differences in their sacrificial layers as consequence of the differences in their manufacturing processes e.g. different etching times. We have made simulations examining how the etching quality reflects in the thermal behaviour of devices. These simulations predicted change in the thermal behaviour of MEMS structures having differences in their sacrificial layers. The theory was tested with measurements of similar MEMS devices prepared with different etching times. In the measurements we used the T3Ster thermal transient tester equipment. The results show that deviations in the devices, as consequence of the different etching times, result in different temperature elevations and manifest also as shift in time in the relevant temperature transient curves
Development and characterisation of pressed packaging solutions for high-temperature high-reliability SiC power modules
SiC is a wide bandgap semiconductor with better electrothermal properties than silicon, including higher temperature of operation, higher breakdown voltage, lower losses and the ability to switch at higher frequencies. However, the power cycling performance of SiC devices in traditional silicon packaging systems is in need of further investigation since initial studies have shown reduced reliability. These traditional packaging systems have been developed for silicon, a semiconductor with different electrothermal and thermomechanical properties from SiC, hence the stresses on the different components of the package will change. Pressure packages, a packaging alternative where the weak elements of the traditional systems like wirebonds are removed, have demonstrated enhanced reliability for silicon devices however, there has not been much investigation on the performance of SiC devices in press-pack assemblies. This will be important for high power applications where reliability is critical. In this paper, SiC Schottky diodes in pressure packages have been evaluated, including the electrothermal characterisation for different clamping forces and contact materials, the thermal impedance evaluation and initial thermal cycling studies, focusing on the use of aluminium graphite as contact material
Arthritis psoriaticával társuló középsúlyos és súlyos psoriasis betegségterhe Magyarországon
INTRODUCTION: Psoriasis is a frequent, chronic, systemic immune-mediated disease mainly affecting the skin and joints. AIM: To assess health related quality of life and cost-of-illness in moderate to severe psoriasis associated with psoriatic arthritis. METHOD: A cross-sectional questionnaire survey was conducted at two academic dermatology clinics in Hungary. RESULTS: Fifty-seven patients (65% males) completed the survey with a mean age of 54.3+/-11.6 years and mean EQ-5D score of 0.48+/-0.4. Mean annual total cost was euro8,977 per patient, of which 71% occurred due to biological therapy and 21% were indirect costs, respectively. Permanent work disability due to psoriasis accounted for euro1,775 (95% of the indirect costs). Per patient costs of subgroups not receiving systemic therapy (21%), traditional systemic therapy (32%), and biological systemic therapy (47%) amounted to the sum of euro1,729, euro1,799, and euro16,983, respectively. CONCLUSIONS: Patients on biological therapy showed significantly better health related quality of life. As for health economics, the efficacy of systemic treatments is appropriate to be assessed together in patients with moderate to severe psoriasis associated with psoriatic arthritis, since actual health gain might exceed that reported in psoriasis or psoriatic arthritis separately. Orv. Hetil., 2014, 155(48), 1913-1921
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