Buckling Induced Nonlinear Phenomenon in a Micro-Electromechanical Resonator

Author(s):  
He Li ◽  
B. Balachandran

Oscillations of micro-electromechanical resonators constructed from clamped-clamped beam structures are studied in this effort. Piezoelectric actuation is used to excite these structures on the input side and piezoelectric sensing is carried out on the output side. Although axial loads in clamped-clamped beam based on micro-electromechanical systems (MEMS) have been considered before, the relevance of buckling to this problem has not studied before in such “small” scale systems. In this work, possibilities for buckling are examined, and it is shown that for resonance excitations, consideration of buckling may help explain associated experimentally observed spatial patterns as a nonlinear phenomenon.

Author(s):  
He Li ◽  
B. Balachandran

Oscillations of clamped-clamped micro-electromechanical resonators are studied in this effort. Piezoelectric actuation is used to excite these structures on the input side and piezoelectric sensing is carried out on the output side. Experimental observations of nonlinear phenomena are presented and nonlinear analysis in progress is presented to explain the experimental observations.


Author(s):  
Ruifeng Guo ◽  
Srikanth Venkataraman

Abstract In this paper, we present a scan chain fault diagnosis procedure. The diagnosis for a single scan chain failure is performed in three steps. The first step uses special chain test patterns to determine both the faulty chain and the fault type in the faulty chain. The second step uses a novel procedure to generate special test patterns to identify the suspect scan cell within a range of scan cells. Unlike previously proposed methods that restrict the location of the faulty scan cell only from the scan chain output side, our method restricts the location of the faulty scan cell from both the scan chain output side and the scan chain input side. Hence the number of suspect scan cells is reduced significantly in this step. The final step further improves the diagnostic resolution by ranking the suspect scan cells inside this range. The proposed technique handles both stuck-at and timing failures (transition faults and hold time faults). The experimental results based on simulation and silicon units for several products show the effectiveness of the proposed method.


2021 ◽  
Vol 13 (5) ◽  
pp. 853
Author(s):  
Mohsen Soltani ◽  
Julian Koch ◽  
Simon Stisen

This study aims to improve the standard water balance evapotranspiration (WB ET) estimate, which is typically used as benchmark data for catchment-scale ET estimation, by accounting for net intercatchment groundwater flow in the ET calculation. Using the modified WB ET approach, we examine errors and shortcomings associated with the long-term annual mean (2002–2014) spatial patterns of three remote-sensing (RS) MODIS-based ET products from MODIS16, PML_V2, and TSEB algorithms at 1 km spatial resolution over Denmark, as a test case for small-scale, energy-limited regions. Our results indicate that the novel approach of adding groundwater net in water balance ET calculation results in a more trustworthy ET spatial pattern. This is especially relevant for smaller catchments where groundwater net can be a significant component of the catchment water balance. Nevertheless, large discrepancies are observed both amongst RS ET datasets and compared to modified water balance ET spatial pattern at the national scale; however, catchment-scale analysis highlights that difference in RS ET and WB ET decreases with increasing catchment size and that 90%, 87%, and 93% of all catchments have ∆ET < ±150 mm/year for MODIS16, PML_V2, and TSEB, respectively. In addition, Copula approach captures a nonlinear structure of the joint relationship with multiple densities amongst the RS/WB ET products, showing a complex dependence structure (correlation); however, among the three RS ET datasets, MODIS16 ET shows a closer spatial pattern to the modified WB ET, as identified by a principal component analysis also. This study will help improve the water balance approach by the addition of groundwater net in the ET estimation and contribute to better understand the true correlations amongst RS/WB ET products especially over energy-limited environments.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3030
Author(s):  
Łukasz Smakosz ◽  
Ireneusz Kreja ◽  
Zbigniew Pozorski

Edgewise compression response of a composite structural insulated panel (CSIP) with magnesium oxide board facings was investigated. The discussed CSIP is a novel multifunctional sandwich panel introduced to the housing industry as a part of the wall, floor, and roof assemblies. The study aims to propose a computational tool for reliable prediction of failure modes of CSIPs subjected to concentric and eccentric axial loads. An advanced numerical model was proposed that includes geometrical and material nonlinearity as well as incorporates the material bimodularity effect to achieve accurate and versatile failure mode prediction capability. Laboratory tests on small-scale CSIP samples of three different slenderness ratios and full-scale panels loaded with three different eccentricity values were carried out, and the test data were compared with numerical results for validation. The finite element (FE) model successfully captured CSIP’s inelastic response in uniaxial compression and when flexural action was introduced by eccentric loads or buckling and predicted all failure modes correctly. The comprehensive validation showed that the proposed approach could be considered a robust and versatile aid in CSIP design.


2021 ◽  
Vol 13 (9) ◽  
Author(s):  
Görkem Cenk Yeşilova ◽  
Andreu Ollé ◽  
Josep Maria Vergès

AbstractIn this manuscript, we present the first systematic refitting results of the small-scale Middle Pleistocene (MIS11) rock shelter site of La Cansaladeta. The lithic materials that have been recovered from the archaeological levels E and J were the main study materials. These levels were investigated regarding spatial pattern analysis and analyzed with auxiliary methods such as quantitative density mapping demonstration and technological analysis of the lithic clusters. Thus, the spatial patterns of the two levels were compared and discussed, in terms of connections, clusters, and movement of the lithic elements. Undoubtedly, the well preservation of the archaeological levels offered a great opportunity for the interpretation of the spatial patterns in a high-resolution perspective. La Cansaladeta has not been paid attention adequately so far may be due to the small dimension of the excavation surface or to the scarcity of faunal record. Our results show that small-scale sites without long-distance refit/conjoin connections can provide significant spatial information. Indeed, if the sites have very well-preserved archaeological levels, the absence of long connections can be supported by the auxiliary methods.


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Do Thi Ngoc Le ◽  
Nguyen Van Thinh ◽  
Nguyen The Dung ◽  
Ralph Mitlöhner

The effects of disturbance regimes on the spatial patterns of the five most abundant species were investigated in three sites in a tropical forest at Xuan Nha Nature Reserve, Vietnam. Three permanent one-ha plots were established in undisturbed forest (UDF), lightly disturbed forest (LDF), and highly disturbed forest (HDF). All trees ≥5 cm DBH were measured in twenty-five 20 m × 20 m subplots. A total of 57 tree species belonging to 26 families were identified in the three forest types. The UDF had the highest basal area (30 m2 ha−1), followed by the LDF (17 m2 ha−1) and the HDF (13.0 m2 ha−1). The UDF also had the highest tree density (751 individuals ha−1) while the HDF held the lowest (478 individuals ha−1). Across all species, there were 417 “juveniles,” 267 “subadults,” and 67 “adults” in the UDF, while 274 “juveniles,” 230 “subadults,” and 36 “adults” were recorded in the LDF. 238 “juveniles,” 227 “subadults,” and 13 “adults” were obtained in the HDF. The univariate and bivariate data with pair- and mark-correlation functions of intra- and interspecific interactions of the five most abundant species changed in the three forest types. Most species indicated clumping or regular distributions at small scale, but a high ratio of negative interspecific small-scale associations was recorded in both the LDF and HDF sites. These were, however, rare in the UDF.


Author(s):  
Xiyue Zhang ◽  
Fangcheng Sun ◽  
Huaizu Wang ◽  
Yi Qu

As a significant ecological corridor from west to east across China, the Yangtze River Economical Belt (YREB) is in great need of green development and transformation. Rather than only focusing on the overall growth of green productivity, it is important to identify whether the technical change is biased towards economic performance or green performance in promoting green productivity. By employing the biased technical change theory and Malmquist index decomposition method, we analyze the green biased technical change in terms of industrial water resources in YREB at the output side and the input side respectively. We find that the green biased technical change varies during 2006–2015 at both the input side and output side in YREB. At the input side, water-saving biased technical change is generally dominant compared to water-using biased technical change during 2006–2015, presenting the substitution effects of non-water production factors. At the output side, the economy-growth biased technical change is the main force to promote green productivity, whereas the role of water-conservation biased technical change is insufficient. The green performance at the output side needs to be strengthened compared to the economic performance in YREB. A series of water-related environmental policies introduced in China since 2008 have promoted the green biased technical change both at the input side and the output side in YREB, but the policy effects at the output side is still inadequate compared to that at the input side. The technological innovation in sewage treatment and control need to catch up with the economic growth in YREB. Our research gives insights to enable a deeper understanding of the green biased technical change in YREB and will benefit more focused policy-making of green innovation.


2020 ◽  
Vol 10 (22) ◽  
pp. 8250
Author(s):  
Bor-Ren Lin ◽  
Kun-Yi Chen

A new hybrid inductor-inductor-capacitor (LLC) converter is investigated to have wide voltage input operation capability and zero-voltage turn-on characteristics. The presented circuit topology can be applied for consumer power units without power factor correction or with long hold-up time requirement, photovoltaic energy conversion and renewable energy power transfer. To overcome the weakness of narrow voltage gain of resonant converter, the hybrid LLC converter with different turns ratio of transformer is presented and the experimental investigation is provided to achieve wide voltage input capability (400 V–50 V). On the input-side, the converter can operate as full bridge resonant circuit or half bridge resonant circuit with input split capacitors for high or low voltage input region. On the output-side, the less or more winding turns is selected to overcome wide voltage input operation. According to the circuit structures and transformer turns ratio, the single stage LLC converter with wide voltage input operation capability (400 V–50 V) is accomplished. The laboratory prototype has been developed and the experimental waveforms are measured and demonstrated to investigate the effectiveness of the presented hybrid LLC converter.


2014 ◽  
Vol 63 (1_suppl) ◽  
pp. 18-37 ◽  
Author(s):  
Stefan Dahlberg ◽  
Jonas Linde ◽  
Sören Holmberg

Although the phenomenon of dissatisfied democrats has been frequently discussed in the literature, it has not often been empirically investigated. This article sets out to analyse the discrepancy between the strong support for democratic principles and the widespread discontent with the way democracy works. Drawing on earlier research on the sources of political support, using data from a wide range of democracies, the relevance of two contrasting explanatory perspectives are investigated. The first perspective argues that the sources of democratic discontent are found on the input-side of the political system in terms of representation. The contrasting view argues that the output-side of the political system is most important, where the quality of government plays the pivotal role. The results of the empirical analysis suggest that, in general, both types of factor are important, but also that these processes to a large extent are conditioned by the level of institutional consolidation.


Sign in / Sign up

Export Citation Format

Share Document