scholarly journals Design and Simulation of MEMS Moisture Sensor Using COMSOL Multiphysics Software

2018 ◽  
Vol 7 (4.26) ◽  
pp. 141
Author(s):  
Muhamad Nazrin Ismail ◽  
Noriah Yusoff ◽  
Nor Hayati Saad ◽  
Amirul Abd Rashid

Micro-electro-mechanical system (MEMS) is a hybrid technology that combines electronic, electric and mechanical technology in a micron-size system. This allowed for higher performance and multifunction devices fabricated at much lighter weight and cost effective. One of the major application of MEMS is in sensor devices area. This paper highlight the simulation study of a typical moisture sensor fabricated from Tungsten Interdigitated (IDE) MEMS device. Using COMSOL Multiphysics software, the moisture sensor was modelled based on the current material and physical dimension and layout. The model then go through validation proses to its sensitivity performance against the experimental result. Subsequently, the optimization on sensor sensitivity was carried out by varying the model parameters including the sensor physical dimension, working temperature and humidity. The simulation result suggest that the sensor sensitivity is highly correlated to the electrode distance value. The average sensitivity of the sensor improved to ~48% better when the distance between reduced to 50% from 6 micron to 3 micron tested at temperature between 25 ̊ C to 45 ̊ C. This information is valuable as the input to the sensor designer in finalizing the MEMS physical layout in producing highly sensitive moisture sensor devices.  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kiyoaki Sugiura ◽  
Yuki Seo ◽  
Takayuki Takahashi ◽  
Hideyuki Tokura ◽  
Yasuhiro Ito ◽  
...  

Abstract Background TAS-102 plus bevacizumab is an anticipated combination regimen for patients who have metastatic colorectal cancer. However, evidence supporting its use for this indication is limited. We compared the cost-effectiveness of TAS-102 plus bevacizumab combination therapy with TAS-102 monotherapy for patients with chemorefractory metastatic colorectal cancer. Method Markov decision modeling using treatment costs, disease-free survival, and overall survival was performed to examine the cost-effectiveness of TAS-102 plus bevacizumab combination therapy and TAS-102 monotherapy. The Japanese health care payer’s perspective was adopted. The outcomes were modeled on the basis of published literature. The incremental cost-effectiveness ratio (ICER) between the two treatment regimens was the primary outcome. Sensitivity analysis was performed and the effect of uncertainty on the model parameters were investigated. Results TAS-102 plus bevacizumab had an ICER of $21,534 per quality-adjusted life-year (QALY) gained compared with TAS-102 monotherapy. Sensitivity analysis demonstrated that TAS-102 monotherapy was more cost-effective than TAS-102 and bevacizumab combination therapy at a willingness-to-pay of under $50,000 per QALY gained. Conclusions TAS-102 and bevacizumab combination therapy is a cost-effective option for patients who have metastatic colorectal cancer in the Japanese health care system.


2020 ◽  
Vol 58 (5A) ◽  
pp. 150
Author(s):  
Thuy Thi Pham ◽  
Hung Quoc Nguyen ◽  
Khai Manh Nguyen

The incredible growth of plastic waste is a major concern for the whole society in recent years. The accumulation of plastic waste has badly effects on wildlife, habitat, and humans. Plastics that act as pollutants are categorized into different sizes, from micro to macro. Disposable plastic waste was collected at the bakery shop and removed the residue food by tap water and NaOH 1M to remove residual food. This study focuses on modify waste plastic by sulfuric acid to bind the sulfonated function group on the structure of the polystyrene chain at room temperature. The sulfonated product was used for removing heavy metal ion in water with the mechanism of the ion exchange process. The prepared ion exchange material was characterized by FTIR and SEM to ensure that the sulfonation process has happened. The chromium (III) ion removal by modified ion exchange product in continuous mode was affected by an operational parameter such as the bed height of sulfonated material. The Yoon-Nelson and Thomas model were used to analyze the experimental result and the model parameters were evaluated. From this result, it can be concluded that with the increasing amount of sulfonated waste polystyrene, exchange capacity, and the time required for a 50% adsorbate breakthrough was higher.


2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Jie Zhang ◽  
Anja Olsen ◽  
Jytte Halkjær ◽  
Kristina Elin Nielsen Petersen ◽  
Anne Tjønneland ◽  
...  

Abstract Background It is easy and cost-effective to ask study participants to self-report height and weight and self-reported anthropometry is therefore widely used in epidemiological studies. However, it is questioned to what degree self-reported adiposity indices are a solid proxy of measured indices in terms of estimates of health outcomes. The current study aimed to quantify the agreement between self-reported and measured anthropometrics, including height, weight, body mass index (BMI), weight circumference (WC), and weight-to-height ratio (WHtR) in a contemporary cohort of adults, and to assess whether anthropometric indices misreporting yielded inaccurate estimates of associations with cardiometabolic biomarkers. Methods Self-reported and measured anthropometric variables were obtained from the Diet, Cancer, and Health-Next Generation Cohort (n = 39,514). Pearson correlations and Lin’s concordance correlations evaluated the correlation between self-report and measured anthropometrics. Misreporting in relation to age, sex and smoking status was investigated. Multivariable regression models and ROC analyses were used to assess the associations of cardiometabolic biomarkers with self-reported and measured general obesity and abdominal obesity. Results Self-reported height was overreported by 1.07 cm, weight was underreported by 0.32 kg on average, which led to self-reported BMI 0.42 kg/m2 lower than measured. Self-reported and measured height, weight, BMI, WC and WHtR were highly correlated (r = 0.98, 0.99, 0.98, 0.88, 0.86, respectively). Associations between self-reported indices and cardiometabolic biomarkers were comparable to associations assessed with measured anthropometrics. Conclusions The self-reported anthropometric indices were reliable when estimating associations with metabolic biomarkers. Key messages This study found overall agreement between self-reported and measured anthropometric variables.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Liu ◽  
Penghao Wang ◽  
Melissa L. Thomas ◽  
Dan Zheng ◽  
Simon J. McKirdy

AbstractInvasive species can lead to community-level damage to the invaded ecosystem and extinction of native species. Most surveillance systems for the detection of invasive species are developed based on expert assessment, inherently coming with a level of uncertainty. In this research, info-gap decision theory (IGDT) is applied to model and manage such uncertainty. Surveillance of the Asian House Gecko, Hemidactylus frenatus Duméril and Bibron, 1836 on Barrow Island, is used as a case study. Our research provides a novel method for applying IGDT to determine the population threshold ($$K$$ K ) so that the decision can be robust to the deep uncertainty present in model parameters. We further robust-optimize surveillance costs rather than minimize surveillance costs. We demonstrate that increasing the population threshold for detection increases both robustness to the errors in the model parameter estimates, and opportuneness to lower surveillance costs than the accepted maximum budget. This paper provides guidance for decision makers to balance robustness and required surveillance expenditure. IGDT offers a novel method to model and manage the uncertainty prevalent in biodiversity conservation practices and modelling. The method outlined here can be used to design robust surveillance systems for invasive species in a wider context, and to better tackle uncertainty in protection of biodiversity and native species in a cost-effective manner.


Author(s):  
Abdullah S Al Saleh ◽  
Patrick Berrigan ◽  
David Anderson ◽  
Sudeep Shivakumar

<p><strong>ABSTRACT</strong></p><p><strong>Background:</strong> To date, there have been few economic evaluations, from a Canadian perspective, of direct oral anticoagulants (DOACs) for the prevention of recurrent venous thromboembolism (VTE) in patients with acute unprovoked VTE. As a result, there is a lack of consensus about which treatment strategy should be adopted in the clinical setting.</p><p><strong>Objectives:</strong> To assess the cost-effectiveness of currently approved anti - coagulant options, in terms of cost per quality-adjusted life-year (QALY) gained, for the prevention of recurrent VTE in patients with unprovoked events managed on an outpatient basis.</p><p><strong>Methods:</strong> Microsoft Excel was used to develop a Markov model. Model parameters were determined using published literature, local hospital data, expert opinion, and chart review. The analysis considered the costs associated with pharmaceuticals, laboratory testing, hematologist fees, and treatment of recurrent VTE and major bleeding events. Effectiveness was measured in terms of QALYs, and incremental cost-effectiveness ratios (ICERs) were calculated.</p><p><strong>Results:</strong> For treatment lasting 3 months, apixaban represented the most cost-effective DOAC relative to low-molecular-weight heparin (LMWH) + vitamin K antagonist, with an ICER of $7379.66. For 6 months of treatment, apixaban again represented the most cost-effective treatment, with an ICER of $84.08 per QALY gained, and this drug dominated all the other strategies at 12 months. For lifetime treatment, DOACs were unlikely to be cost-effective, given a maximum willingness to pay of $50 000 to $100 000 per QALY. In a probabilistic sensitivity analysis at 6 months, 46.4% of iterations resulted in apixaban having lower costs and better outcomes than LMWH + vitamin K antagonist, and 78.6% of iterations resulted in an ICER below $100 000</p><p><strong>Conclusions:</strong> The findings of this study suggest that apixaban is likely cost-effective for treatment durations of 3, 6, and 12 months. However, for indefinite treatment, DOACs were unlikely to be cost-effective.</p><p><strong>RÉSUMÉ</strong></p><p><strong>Contexte :</strong> À ce jour, on a réalisé peu d’évaluations économiques, d’un point de vue canadien, sur les anticoagulants oraux directs (AOD) utilisés dans la prévention de la thromboembolie veineuse (TEV) récurrente chez les patients atteints de TEV idiopathique aiguë. Pour cette raison, aucun consensus n’a été établi quant à la stratégie thérapeutique à adopter en milieu clinique.</p><p><strong>Objectif :</strong> Évaluer le rapport coût-efficacité des anticoagulothérapies actuellement approuvées, en ce qui a trait au coût par année de vie pondérée par la qualité (QALY) gagnée, pour la prévention de la TEV récurrente chez les patients ayant subi des événements idiopathiques qui ont été traités en consultation externe.</p><p><strong>Méthodes :</strong> Le logiciel Excel de Microsoft a servi à créer un modèle de Markov. Les paramètres du modèle ont été établis à l’aide de la littérature, de données de l’hôpital local, d’opinions d’experts et d’une analyse de dossiers médicaux. L’analyse prenait en compte les coûts associés aux médicaments, aux examens de laboratoire, aux honoraires d’hématologues et au traitement de la TEV récurrente et d’hémorragies importantes. L’efficacité était mesurée en nombre de QALY et les rapports coûtefficacité différentiels ont été calculés.</p><p><strong>Résultats :</strong> Pour un traitement de trois mois, l’apixaban représentait l’AOD offrant le meilleur rapport coût-efficacité comparativement à l’héparine de bas poids moléculaire (HBPM) + un antagoniste de la vitamine K; il présentait un rapport coût-efficacité différentiel de 7379,66 $. Pour un traitement de six mois, l’apixaban représentait à nouveau le traitement le plus efficace par rapport au coût; il présentait un rapport coût-efficacité différentiel de 84,08 $ par QALY gagnée. Ce médicament surclassait toutes les autres stratégies après douze mois de traitement. En ce qui concerne un traitement à vie, les AOD offraient probablement un moins bon rapport coût-efficacité, compte tenu d’une propension à payer maximale se situant entre 50 000 $ et 100 000 $ par QALY. Dans une analyse de sensibilité probabiliste au sixième mois de traitement, 46,4 % des itérations se traduisaient par des coûts moins élevés et de meilleurs résultats pour l’apixaban relativement à l’HBPM + un antagoniste de la vitamine K. De plus, 78,6 % des itérations se traduisaient par un rapport coût-efficacité différentiel de moins de 100 000 $.</p><p><strong>Conclusions :</strong> Ces résultats laissent croire que l’apixaban présente probablement un rapport coût-efficacité intéressant pour les traitements d’une durée de 3, 6 et 12 mois. Cependant, en ce qui concerne un traitement d’une durée indéterminée, les AOD ne sont sans doute pas avantageux.</p>


2019 ◽  
Vol 117 (4) ◽  
pp. 317-322
Author(s):  
Michael G Just ◽  
Steven D Frank

AbstractTree-stem growth is an important metric for evaluating many ecological and silvicultural research questions. However, answering these questions may require monitoring growth on many individual trees that span changing environments and geographies, which can incur significant costs. Recently, citizen science has been successfully employed as a cost-effective approach to collect data for large-scale projects that also increases scientific awareness. Still, citizen-science-led tree-growth monitoring requires the use of tools that are affordable, understandable, and accurate. Here, we compare an inexpensive, easy-to-install dendrometer band to two other bands that are more expensive with more complex installations. We installed a series of three dendrometers on 31 red maples (Acer rubrum) in two urban areas in the eastern United States. We found that the stem-growth measurements reported by these dendrometers were highly correlated and, thus, validate the utility of the inexpensive band.


2003 ◽  
Vol 1856 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Sravanthi Konduri ◽  
Samuel Labi ◽  
Kumares C. Sinha

Incident prediction models are presented for the Interstate 80/Interstate 94 (Borman Expressway in northwestern Indiana) and Interstate 465 (northeastern Indianapolis, Indiana) freeway sections developed as a function of traffic volume, truck percentage, and weather. Separate models were developed for all incidents and noncrash incidents. Three model types were considered (Poisson regression, negative binomial regression, and nonlinear regression), and the results were compared based on magnitudes and signs of model parameter estimates and t-statistics. Least-squares estimation and maximum-likelihood methods were used to estimate the model parameters. Data from the Indiana Department of Transportation and the Indiana Climatology Database were used to establish the relationships. For a given session and incident category, the results from the Poisson and negative binomial models were found to be consistent. It was observed that, unlike section length, traffic volume is nonlinearly related to incidents, and therefore these two variables have to be considered as separate terms in the modeling process. Truck percentage was found to be a statistically significant factor affecting incident occurrence. It was also found that the weather variable (rain and snow) was negatively correlated to incidents. The freeway incident models developed constitute a useful decision support tool for implementation of new freeway patrol systems or for expansion of existing ones. They are also useful for simulating incident occurrences with a view to identifying elements of cost-effective freeway patrol strategies (patrol deployment policies, fleet size, crew size, and beat routes).


2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840027 ◽  
Author(s):  
Tzong-Shyng Leu ◽  
Ruei-Hung Kao

The study is to develop a novel bionic micropump, mimicking blood-suck mechanism of mosquitos with a similar efficiency of 36%. The micropump is produced by using micro-electro-mechanical system (MEMS) technology, PDMS (polydimethylsiloxane) to fabricate the microchannel, and an actuator membrane made by Fe-PDMS. It employs an Nd-FeB permanent magnet and PZT to actuate the Fe-PDMS membrane for generating flow rate. A lumped model theory and the Taguchi method are used for numerical simulation of pulsating flow in the micropump. Also focused is to change the size of mosquito mouth for identifying the best waveform for the transient flow processes. Based on computational results of channel size and the Taguchi method, an optimization actuation waveform is identified. The maximum pumping flow rate is 23.5 [Formula: see text]L/min and the efficiency is 86%. The power density of micropump is about 8 times of that produced by mosquito’s suction. In addition to using theoretical design of the channel size, also combine with Taguchi method and asymmetric actuation to find the optimization actuation waveform, the experimental result shows the maximum pumping flowrate is 23.5 [Formula: see text]L/min and efficiency is 86%, moreover, the power density of micropump is 8 times higher than mosquito’s.


1988 ◽  
Vol 28 (1) ◽  
pp. 29 ◽  
Author(s):  
HW Raadsma ◽  
KJ Thornberry

The major factors thought to affect the relationship between wax and suint and fleece rot susceptibility were examined. Time of sampling and fleece rot induction were the major factors which resulted in changes in wax and suint levels in the fleece and their relationship with fleece rot. Variation in staple portion used for extraction did alter the yields of wax and suint, but these yields were highly correlated to full staple values in the case of wax (r = 0.77-0.92) and lower in the case of suint (r = 0.23-0.77). Variation in length of staple used did not alter the relationship between wax and suint levels and fleece rot. We conclude that wax would be a more suitable indicator of fleece rot susceptibility than would suint because of its more stable relationship with fleece rot. Differences between sheep affected and unaffected with fleece rot in wax and suint values were small and consistent for the 15 Merino genotypes sampled. The evaluation of wax for indirect selection against fleece rot will depend on further evaluation of the required genetic parameters and a more cost-effective means of measurement.


2019 ◽  
Vol 262 ◽  
pp. 05014 ◽  
Author(s):  
Cezary Szydłowski ◽  
Jarosław Górski ◽  
Marcin Stienss ◽  
Łukasz Smakosz

The paper presents selected test results of asphalt mixture conducted in low temperatures. The obtained parameters are highly diverse. It concerns ultimate breaking loads, stiffness parameters related to Young's modulus but also the fracture course. Statistical analysis upon the results makes it possible to relevantly estimate the material-defining parameter values. Such a random approach leads to the mean values of breaking and fracture-triggering loads, dealing with their dispersion too. The estimated parameters allow to form appropriate numerical models of asphalt mixture specimens. This type of analysis supports the laboratory tests. The paper presents the authors' simplified model considering non-uniform material features. The results reflect the scatter of real laboratory test outcomes. In order to do so an algorithm to calibrate the numerical model parameters was created.


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