Numerical Investigation of Multi-Scale Mixing in Microchannel T-Junction With Wavy Structure

2012 ◽  
Author(s):  
Nita Solehati ◽  
Joonsoo Bae ◽  
Agus Pulung Sasmito
Keyword(s):  
Schmidt Number ◽  
Molecular Diffusion ◽  
Chaotic Mixing ◽  
Small Scale ◽  
Transport Mechanisms ◽  
Huge Amount ◽  
Multi Scale ◽  
Wavy Structure ◽  
Mixing Quality

Mixing in chemical microreactors is a multi-scale processes as the transport mechanisms occur at different length scales. The small scale mixing depends mainly on molecular diffusion which causes conventional microchannel T-junction has poor mixing quality. To improve the quality, one can utilize secondary flow generated by wavy structure to enhance chaotic mixing. To gain better understanding of the interplay of transport mechanism, we develop numerical model for mixing in micro-channel T-junction with wavy structure. To ensure robust and accurate solutions, several discretization methods and mesh sizes were tested and compared. It is found that the solutions are sensitive to the Reynolds; huge amount of mesh (>107) is required to resolve small molecular diffusion and chaotic mixing especially at high Schmidt number, whilst relatively lesser mesh is found to be sufficient for conventional T-junction. Further, parallelization is found to be beneficial to expedite the computation, albeit the speed is not linear with the number of the processors. The mixing quality of T-junction with wavy structure is then compared with that of conventional T-junction counterpart. It is noted that up to 50% improvement of mixing quality is achieved with wavy structure which has potential for several applications.

Evaluation of the mixing quality of high-viscosity yield stress fluids in a tubular reactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Le Xie ◽  
Guangwen He ◽  
Bin Yu ◽  
Shaowei Yan
Keyword(s):  
Yield Stress ◽  
Large Scale ◽  
Molecular Diffusion ◽  
Time History ◽  
High Viscosity ◽  
Cfd Model ◽  
Step Method ◽  
Mean Velocity ◽  
Mixing Quality

Abstract In this study, the mixing quality of high-viscosity yield stress fluid (Carbopol aqueous solution) under laminar and turbulent flow regimes was evaluated through a numerical experimental study. A three-dimensional computational fluid dynamics large-eddy simulation (CFD-LES) model was employed to capture large-scale vortex structures. The proposed CFD model was validated by the experimental data in terms of mean velocity profiles and velocity-time history. Thereafter, the CFD model was applied to simulate the residence time distribution using the tracking technique: tracer pulse method and step method. In addition, the non-ideal flow phenomena caused by molecular diffusion and eddy diffusion were evaluated. The effects of the rheological properties on the mixing performance were also investigated. The presented results can provide useful guidance to enhance mass transfer in reactors with high-viscosity fluids.

PENGUATAN KAPASITAS WIRAUSAHAWAN MIKRO MENGGUNAKAN METODE PENDAMPINGAN DI DESA MEKARGALIH, KECAMATAN JATINANGOR, KABUPATEN SUMEDANG

Dharmakarya ◽  
2020 ◽  
Vol 9 (2) ◽  
Author(s):  
RUDI Saprudin DARWIS
Keyword(s):  
Service Learning ◽  
Business Development ◽  
Small Scale ◽  
Learning Program ◽  
Student Service

ABSTRACTWeaknesses that are still commonly found in the businesses carried out by MSME entrepreneurs are the weakness of business accounting and packaging. Small scale business with limited marketing is seen as not requiring bookkeeping in its management and does not require packaging that is too good. This is the basis for the need for assistance to improve the capacity of MSME actors. Improving the capacity of MSME actors individually is done using the mentoring method. The choice to use a mentoring method to increase business productivity. Assistance was carried out with students of SMEs during the student service-learning program in Mekargalih Village, Jatinangor District, Sumedang Regency. Bookkeeping assistance is carried out by students by carrying out bookkeeping practices together so that the community can continue to learn good bookkeeping methods. Likewise, assistance in improving the quality of shredded chili packaging. Students help SMEs in designing packaging that will be used on their products. The assistance process is considered effective in supporting the business development of MSME entrepreneurs because the process can be carried out intensively. ABSTRAKKelemahan yang masih banyak ditemui pada usaha-usaha yang dilakukan pelaku UMKM adalah lemahnya pembukuan usaha dan pengemasannya. Skala usaha yang kecil dengan pemasaran yang terbatas dipandang tidak memerlukan pembukuan dalam pengelolaanya serta tidak memerlukan pengemasan yang terlalu bagus. Hal ini menjadi dasar perlunya dilakukan pendampingan untuk meningkatkan kapasitas pelaku UMKM. Peningkatan kapasitas pelaku UMKM secara perorangan dilakukan dengan menggunakan metode pendampingan. Pilihan untuk menggunakan metode pendampingan dalam meningkatkan produktivitas usahanya. Pendampingan dilakukan bersama mahasiswa terhadap pelaku UMKM selama pelaksanaan KKN mahasiswa di Desa Mekargalih, Kecamatan Jatinangor, Kabupaten Sumedang. Pendampingan pembukuan dilakukan mahasiswa dengan cara melakukan praktik pembukuan bersama-sama sehingga masyarakat bisa terus mempelajari cara pembukuan yang baik. Demikian juga dengan pendampingan dalam peningkatan mutu kualitas kemasan abon cabe. Mahasiswa membantu pelaku UMKM dalam merancang kemasan yang akan digunakan pada produknya. Proses pendampingan dinilai efektif dalam mendukung pengembangan usaha pelaku UMKM karena proses bisa dilakukan secara intensif.

scholarly journals Detection of Myocardial Infarction Using ECG and Multi-Scale Feature Concatenate

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1906
Author(s):  
Jia-Zheng Jian ◽  
Tzong-Rong Ger ◽  
Han-Hua Lai ◽  
Chi-Ming Ku ◽  
Chiung-An Chen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Network Structure ◽  
Class Imbalance ◽  
Class Imbalance Problem ◽  
Multi Scale ◽  
Imbalance Problem ◽  
Average Accuracy ◽  
Significant Difference ◽  
Electrocardiogram Ecg

Diverse computer-aided diagnosis systems based on convolutional neural networks were applied to automate the detection of myocardial infarction (MI) found in electrocardiogram (ECG) for early diagnosis and prevention. However, issues, particularly overfitting and underfitting, were not being taken into account. In other words, it is unclear whether the network structure is too simple or complex. Toward this end, the proposed models were developed by starting with the simplest structure: a multi-lead features-concatenate narrow network (N-Net) in which only two convolutional layers were included in each lead branch. Additionally, multi-scale features-concatenate networks (MSN-Net) were also implemented where larger features were being extracted through pooling the signals. The best structure was obtained via tuning both the number of filters in the convolutional layers and the number of inputting signal scales. As a result, the N-Net reached a 95.76% accuracy in the MI detection task, whereas the MSN-Net reached an accuracy of 61.82% in the MI locating task. Both networks give a higher average accuracy and a significant difference of p < 0.001 evaluated by the U test compared with the state-of-the-art. The models are also smaller in size thus are suitable to fit in wearable devices for offline monitoring. In conclusion, testing throughout the simple and complex network structure is indispensable. However, the way of dealing with the class imbalance problem and the quality of the extracted features are yet to be discussed.

scholarly journals Multi-Scale Ionospheric Anomalies Monitoring and Spatio-Temporal Analysis during Intense Storm

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 215
Author(s):  
Na Cheng ◽  
Shuli Song ◽  
Wei Li
Keyword(s):  
Magnetic Storm ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Ionospheric Disturbance ◽  
Ionospheric Scintillation ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Multi Scale ◽  
Intense Storm

The ionosphere is a significant component of the geospace environment. Storm-induced ionospheric anomalies severely affect the performance of Global Navigation Satellite System (GNSS) Positioning, Navigation, and Timing (PNT) and human space activities, e.g., the Earth observation, deep space exploration, and space weather monitoring and prediction. In this study, we present and discuss the multi-scale ionospheric anomalies monitoring over China using the GNSS observations from the Crustal Movement Observation Network of China (CMONOC) during the 2015 St. Patrick’s Day storm. Total Electron Content (TEC), Ionospheric Electron Density (IED), and the ionospheric disturbance index are used to monitor the storm-induced ionospheric anomalies. This study finally reveals the occurrence of the large-scale ionospheric storms and small-scale ionospheric scintillation during the storm. The results show that this magnetic storm was accompanied by a positive phase and a negative phase ionospheric storm. At the beginning of the main phase of the magnetic storm, both TEC and IED were significantly enhanced. There was long-duration depletion in the topside ionospheric TEC during the recovery phase of the storm. This study also reveals the response and variations in regional ionosphere scintillation. The Rate of the TEC Index (ROTI) was exploited to investigate the ionospheric scintillation and compared with the temporal dynamics of vertical TEC. The analysis of the ROTI proved these storm-induced TEC depletions, which suppressed the occurrence of the ionospheric scintillation. To improve the spatial resolution for ionospheric anomalies monitoring, the regional Three-Dimensional (3D) ionospheric model is reconstructed by the Computerized Ionospheric Tomography (CIT) technique. The spatial-temporal dynamics of ionospheric anomalies during the severe geomagnetic storm was reflected in detail. The IED varied with latitude and altitude dramatically; the maximum IED decreased, and the area where IEDs were maximum moved southward.

scholarly journals 106 - Environmental Influences on the Cognitive and Psychological Well Being of Older Adults with Dementia

2020 ◽  
Vol 32 (S1) ◽  
pp. 15-16
Author(s):  
William E. Reichman ◽  
L. Bradford Perkins ◽  
Hilde Verbeek
Keyword(s):  
Quality Of Life ◽  
Older Adults ◽  
Physical Environment ◽  
Culture Change ◽  
Long Term Care ◽  
Small Scale ◽  
Term Care

This symposium will review the latest data on the influence of environmental design and its attributes on the cognitive and psychological wellbeing of older adults living with dementia. The presenters will cover the myriad ways in which the physical environment of care can adapt to the changing demands of older adults with sensory, motor and cognitive deficits and foster optimal functioning and quality of life. The role of emerging technologies will also be reviewed as they complement the contribution of the design of the physical environment to the wellbeing of older adults with cognitive impairment. Information will be offered through a review of the existing research literature as well as case studies that illustrate the impact of environmental modification on fostering wellbeing and minimizing the emergence of the behavioral and psychological symptoms of dementia. The presenters will represent and integrate sensibilities that have emerged from the fields of architecture, cognitive neuroscience and psychology.How the Principles of the Culture Change Movement Inform Environmental Design and the Application of Technology in the Care of Older Adults Living with DementiaWilliam E. ReichmanThe culture change movement informs a number of principles that have been applied to more contemporary design concepts for the congregate care of older adults living with dementia. This talk will review the core tenets of the Culture Change Movement as exemplified by the Greenhouse, Dementia Village and other innovative models of congregate long-term care. Specific reference will be made to how these tenets have been operationalized around the world into the design of programming and the creation of residential care environments that foster a better quality of life for older adults and an enhanced work environment for care providers. This talk will also include the emerging role of technologies that complement innovative design of the environment and which foster optimized social and recreational functioning of older adults living with dementia.A Better Life Through a Better Nursing Home DesignL. Bradford PerkinsOver the last 20 years there has been extensive experimentation related to the role of the environment in the housing, care and treatment of persons with Alzheimer’s and other age related dementias. Prior to that time the typical housing and care environment was a locked unit in a skilled nursing or other restrictive senior living facility. In 1991 the Presbyterian Association on Aging in Western Pennsylvania opened Woodside Place on its Oakmont campus. This small 36 bed facility was designed to incorporate the latest research and care experience with persons suffering from these issues. This one small project, as well as the long post occupancy research led by Carnegie Mellon University, clearly demonstrated that individuals with Alzheimer’s and related forms of dementia could lead a healthier, happier, higher quality of life in a more residential, less restrictive environment. Not everything in this pioneering project worked, and five generations of living and care models have followed that have refined the ideas first demonstrated by Woodside Place. Bradford Perkins, whose firm designed Woodside Place and over 100 other related projects, will discuss what was learned from Woodside Place as well as the five generations of projects (and post occupancy research) that followed.Innovative dementia care environments as alternatives for traditional nursing homes: evidence and experiences from the NetherlandsHilde VerbeekKey goals of the dementia care environment focus on increasing autonomy, supporting independence and trying to enable one’s own lifestyle for as long as possible. To meet these goals, innovative, small-scale and homelike care environments have been developed that have radically changed the physical, social and organizational aspects of long-term care in the Netherlands. This presentation discusses various Dutch models that have implemented small-scale and homelike care environments, including green care farms, dementia village and citizen initiatives. The models reflect a common care concept, focusing on residents’ remaining strengths, providing opportunity for choice and aiming to sustain a sense of self and control. A small number of residents (usually 6 to 8) live together in a homelike environment and nursing staff are part of the household. Residents are encouraged to participate in daily household activities, emphasizing normalization of daily life with person-centred care. The physical environment resembles an archetypal home. This talk presents the scientific evidence on the impact and effects of these small-scale, homelike models on residents, their family caregivers and staff. Furthermore, the presentation will highlight working approaches and how these initiatives have positively influenced routine care across the long-term care spectrum.

scholarly journals Machine Learning for Dissimulating Reality

Proceedings ◽  
2021 ◽  
Vol 77 (1) ◽  
pp. 17
Author(s):  
Andrea Giussani
Keyword(s):  
Machine Learning ◽  
Language Processing ◽  
Huge Amount ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Technological Advances ◽  
Textual Data ◽  
Musical Scores ◽  
Mathematical Formulas

In the last decade, advances in statistical modeling and computer science have boosted the production of machine-produced contents in different fields: from language to image generation, the quality of the generated outputs is remarkably high, sometimes better than those produced by a human being. Modern technological advances such as OpenAI’s GPT-2 (and recently GPT-3) permit automated systems to dramatically alter reality with synthetic outputs so that humans are not able to distinguish the real copy from its counteracts. An example is given by an article entirely written by GPT-2, but many other examples exist. In the field of computer vision, Nvidia’s Generative Adversarial Network, commonly known as StyleGAN (Karras et al. 2018), has become the de facto reference point for the production of a huge amount of fake human face portraits; additionally, recent algorithms were developed to create both musical scores and mathematical formulas. This presentation aims to stimulate participants on the state-of-the-art results in this field: we will cover both GANs and language modeling with recent applications. The novelty here is that we apply a transformer-based machine learning technique, namely RoBerta (Liu et al. 2019), to the detection of human-produced versus machine-produced text concerning fake news detection. RoBerta is a recent algorithm that is based on the well-known Bidirectional Encoder Representations from Transformers algorithm, known as BERT (Devlin et al. 2018); this is a bi-directional transformer used for natural language processing developed by Google and pre-trained over a huge amount of unlabeled textual data to learn embeddings. We will then use these representations as an input of our classifier to detect real vs. machine-produced text. The application is demonstrated in the presentation.

scholarly journals Small-Scale Coastal Fisheries in the Midst of Adaptation and Diversification: Insights from Southern Italy

2021 ◽  
Vol 13 (13) ◽  
pp. 7393
Author(s):  
Agata Nicolosi ◽  
Donatella Di Gregorio ◽  
Giuseppe Arena ◽  
Valentina Rosa Laganà ◽  
Donatella Privitera
Keyword(s):  
Southern Italy ◽  
Multiple Correspondence Analysis ◽  
Marketing Strategies ◽  
Small Scale ◽  
Artisanal Fishing ◽  
Economic Activities ◽  
Coastal Fisheries ◽  
Cluster Identification ◽  
The Eu

The study looks at the problems facing coastal fishing communities. It highlights the impacts that, in the complex framework of the EU reforms, have manifested themselves on economic activities and on society. The aim of the paper is twofold: to examine small-scale artisanal fishing in an area of Southern Italy in order to develop resilience and diversification and at the same time to outline the profiles of local bluefish buyers to highlight development strategies for the sector. The research carried out through a direct survey by administering a questionnaire to fishermen operating in areas of Southern Italy and the data cross-referenced with the opinions of local consumers. A conjoint experiment, followed by a multiple correspondence analysis and cluster identification, was used to outline the profiles of local bluefish buyers. The results of the analysis reveal that the fish market and the restaurant sector are the main distribution channels preferred by fishermen. Furthermore, fishermen are very sensitive to environmental issues and are willing to collaborate and actively participate in the environmental protection of the sea. Consumers recognise the quality of local bluefish, and they implicitly perceive the sustainability of the method of capture. The results show the need to undertake synergistic actions for the fishing industry, capable of activating marketing strategies adequately to support, promote and develop the sector. The results of the study provide helpful information for food companies in order to better segment their market and target their consumers, as well as to effectively promote their product using brands, certifications and traceability.

Research Note: Women's Experience of the Mother Role

1993 ◽  
Vol 41 (2) ◽  
pp. 347-360 ◽  
Author(s):  
Pat O'Connor
Keyword(s):  
Medical Records ◽  
Rating Scales ◽  
Empirical Work ◽  
Research Note ◽  
Small Scale ◽  
Intensive Study ◽  
Lower Middle Class ◽  
Women's Experience ◽  
Mother Role

Despite the feminist critique of the assumptions implicit in the ideology of motherhood, relatively little empirical work has been done on women's own experience of this role. This research note uses data from a small scale intensive study of 51 married or cohabiting mothers aged 20–42 years old, whose oldest child was 15 years old, and who were randomly selected from medical records in a lower middle class area of North London. Building on Boulton's (1983) conceptualization, it differentiates between three aspects of this role (namely their commitment to it; its perceived identity enhancing/ destructive character and the positive/negative quality of their interaction with their children). These women's experience of the mother role was then assessed on these dimensions – using rating scales and anchoring examples (which are illustrated here). This research note suggests that even within this relatively homogenous lower middle/upper working class sample, the experience of motherhood was extremely varied: with less than half of the sample experiencing it positively at all three levels. An attempt is made to explain this variation.

Build Direction Effects on Additively Manufactured Channels

2015 ◽  
Author(s):  
Jacob C. Snyder ◽  
Curtis K. Stimpson ◽  
Karen A. Thole ◽  
Dominic Mongillo
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Small Scale ◽  
Turbine Cooling ◽  
Gas Turbine Cooling ◽  
Gas Turbine Heat Transfer ◽  
Manufacturing Techniques ◽  
Traditional Manufacturing

With the advances of Direct Metal Laser Sintering (DMLS), also generically referred to as additive manufacturing, novel geometric features of internal channels for gas turbine cooling can be achieved beyond those features using traditional manufacturing techniques. There are many variables, however, in the DMLS process that affect the final quality of the part. Of most interest to gas turbine heat transfer designers are the roughness levels and tolerance levels that can be held for the internal channels. This study investigates the effect of DMLS build direction and channel shape on the pressure loss and heat transfer measurements of small scale channels. Results indicate that differences in pressure loss occur between the test cases with differing channel shapes and build directions, while little change is measured in heat transfer performance.

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