scholarly journals Steam System Load Shedding Operational Analysis Using Dynamics Simulation of a Fertilizer Plant

2021 ◽  
Vol 287 ◽  
pp. 03017
Author(s):  
Abdul Rahim Norman ◽  
Azleen Azna Mohd Khairil Hing ◽  
M. Azfar Md Jaafar ◽  
Farah Syamim Anwar
Keyword(s):  
Case Studies ◽  
Load Shedding ◽  
Dynamics Simulation ◽  
Feed Water ◽  
Fuel Gas ◽  
Transient Behaviour ◽  
Fertilizer Plant ◽  
Plant Hydraulics ◽  
The Impact ◽  
Steam System

Steam system operation of a fertilizer plant can be complex due to high number of equipment, unavailable redundancy of steam suppliers and inter-dependency behaviour between steam users. The plant is subjected to partial or total shutdown whenever one boiler trips as both existing boilers are operating close to design capacity. Installation of an additional boiler will provide additional capacity margin in the event of one boiler trips. iCON(Symmetry) was used as the dynamic process simulation tool to establish proper management for load shedding activity with three boilers in operation. Model was developed for the integrated steam header, fuel gas and boiler feed water network. A detailed representation of the actual plant was achieved by incorporating plant hydraulics based on actual piping configurations, high fidelity equipment modelling, process control configurations, trip sequencing and operator manual interventions. This approach gives high accuracy in replicating the plant’s transient behaviour for load shedding case studies. The case studies prove the three boiler arrangement is able to sustain the plant’s continuous operation. An operational strategy was developed to minimize the impact of equipment trips. It is recommended to expand the model to include the process side to represent the actual plant behaviour with higher accuracy.

Navigating the New Retail Landscape

2020 ◽  
Author(s):  
Alan Treadgold ◽  
Jonathan Reynolds
Keyword(s):  
Case Studies ◽  
Business Models ◽  
Retail Industry ◽  
Drivers Of Change ◽  
Economic Crises ◽  
Global Pandemic ◽  
Personal Leadership ◽  
Practical Guidance ◽  
The Impact ◽  
Rapid Emergence

The retail industry globally is in an era of profound, perhaps unprecedented, change, change which has been further accelerated for many by the impact of the COVID-19 global pandemic and its attendant health and economic crises. This book is intended to serve as a wide-ranging, robust, practical guide to leaders of enterprises tasked with understanding and delivering success in the new landscape of retailing. Part 1 describes the major directions and drivers of change that define the new global landscape of retailing. Accelerating changes in technology, the rise to prominence globally of internet enabled shoppers and the rapid emergence of entirely new retail enterprises and business models are combining to re-shape the very fundamentals of the retail industry. The new landscape of retailing is unforgiving: success can be achieved more quickly than ever before but failure is equally rapid. Opportunities in the new landscape of retailing are profound, but so too are the challenges. Part 2 discusses the structures, skills and capabilities that retail enterprises will need to be successful in this new landscape and the skills and capabilities required of the leaders of retail enterprises. More than 25 detailed case studies of innovative, successful enterprises internationally and more than one hundred smaller examples, all updated and many new since the first edition, are used to illustrate the themes discussed. Frameworks are presented to provide practical guidance for enterprise leaders to understand and contextualize the nature of change re-shaping retail landscapes globally. Clear guidance is given of the capabilities, skills and perspectives needed at both an enterprise and personal leadership level to deliver success in the new landscape of retailing.

Impact Load Buffering Method Based on Stress Wave Attenuation Principle

2019 ◽  
Vol 11 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Lin Gan ◽  
He Zhang ◽  
Cheng Zhou ◽  
Lin Liu
Keyword(s):  
Stress Wave ◽  
Wave Attenuation ◽  
Impact Load ◽  
Dynamics Simulation ◽  
Scanning System ◽  
Isolation Method ◽  
Element Analysis ◽  
System A ◽  
High Emission ◽  
The Impact

Rotating scanning motor is the important component of synchronous scanning laser fuze. High emission overload environment in the conventional ammunition has a serious impact on the reliability of the motor. Based on the theory that the buffer pad can attenuate the impact stress wave, a new motor buffering Isolation Method is proposed. The dynamical model of the new buffering isolation structure is established by ANSYS infinite element analysis software to do the nonlinear impact dynamics simulation of rotating scanning motor. The effectiveness of Buffering Isolation using different materials is comparatively analyzed. Finally, the Macht hammer impact experiment is done, the results show that in the experience of the 70,000[Formula: see text]g impact acceleration, the new buffering Isolation method can reduce the impact load about 15 times, which can effectively alleviate the plastic deformation of rotational scanning motor and improve the reliability of synchronization scanning system. A new method and theoretical basis of anti-high overload research for Laser Fuze is presented.

scholarly journals The Impact of the Electric Field on Surface Condensation of Water Vapor: Insight from Molecular Dynamics Simulation

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 64 ◽  
Author(s):  
Qin Wang ◽  
Hui Xie ◽  
Zhiming Hu ◽  
Chao Liu
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Electric Field ◽  
Intermolecular Forces ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Attraction Force ◽  
Condensation Rate ◽  
Shape Transformation ◽  
The Impact

In this study, molecular dynamics simulations were carried out to study the coupling effect of electric field strength and surface wettability on the condensation process of water vapor. Our results show that an electric field can rotate water molecules upward and restrict condensation. Formed clusters are stretched to become columns above the threshold strength of the field, causing the condensation rate to drop quickly. The enhancement of surface attraction force boosts the rearrangement of water molecules adjacent to the surface and exaggerates the threshold value for shape transformation. In addition, the contact area between clusters and the surface increases with increasing amounts of surface attraction force, which raises the condensation efficiency. Thus, the condensation rate of water vapor on a surface under an electric field is determined by competition between intermolecular forces from the electric field and the surface.

scholarly journals An evaluation of the implementation of quality improvement (QI) in primary care dentistry: a multi-method approach

2021 ◽  
Vol 10 (2) ◽  
pp. e000839
Author(s):  
Heather Cassie ◽  
Vinay Mistry ◽  
Laura Beaton ◽  
Irene Black ◽  
Janet E Clarkson ◽  
...  
Keyword(s):  
Primary Care ◽  
Quality Improvement ◽  
Case Studies ◽  
Quality Care ◽  
Theoretical Domains Framework ◽  
Team Members ◽  
Knowledge And Skills ◽  
Scottish Government ◽  
The Impact

ObjectivesEnsuring that healthcare is patient-centred, safe and harm free is the cornerstone of the NHS. The Scottish Patient Safety Programme (SPSP) is a national initiative to support the provision of safe, high-quality care. SPSP promotes a coordinated approach to quality improvement (QI) in primary care by providing evidence-based methods, such as the Institute for Healthcare Improvement’s Breakthrough Series Collaborative methodology. These methods are relatively untested within dentistry. The aim of this study was to evaluate the impact to inform the development and implementation of improvement collaboratives as a means for QI in primary care dentistry.DesignA multimethod study underpinned by the Theoretical Domains Framework and the Kirkpatrick model. Quantitative data were collected using baseline and follow-up questionnaires, designed to explore beliefs and behaviours towards improving quality in practice. Qualitative data were gathered using interviews with dental team members and practice-based case studies.ResultsOne hundred and eleven dental team members completed the baseline questionnaire. Follow-up questionnaires were returned by 79 team members. Twelve practices, including two case studies, participated in evaluation interviews. Findings identified positive beliefs and increased knowledge and skills towards QI, as well as increased confidence about using QI methodologies in practice. Barriers included time, poor patient and team engagement, communication and leadership. Facilitators included team working, clear roles, strong leadership, training, peer support and visible benefits. Participants’ knowledge and skills were identified as an area for improvement.ConclusionsFindings demonstrate increased knowledge, skills and confidence in relation to QI methodology and highlight areas for improvement. This is an example of partnership working between the Scottish Government and NHSScotland towards a shared ambition to provide safe care to every patient. More work is required to evaluate the sustainability and transferability of improvement collaboratives as a means for QI in dentistry and wider primary care.

scholarly journals DSM Generation from Single and Cross-Sensor Multi-View Satellite Images Using the New Agisoft Metashape: The Case Studies of Trento and Matera (Italy)

2021 ◽  
Vol 13 (4) ◽  
pp. 593
Author(s):  
Lorenzo Lastilla ◽  
Valeria Belloni ◽  
Roberta Ravanelli ◽  
Mattia Crespi
Keyword(s):  
Case Studies ◽  
Accuracy Assessment ◽  
Stereo Pair ◽  
Commercial Software ◽  
Processing Module ◽  
Land Covers ◽  
Image Metadata ◽  
The Impact ◽  
The City ◽  
Reliable Software

DSM generation from satellite imagery is a long-lasting issue and it has been addressed in several ways over the years; however, expert and users are continuously searching for simpler but accurate and reliable software solutions. One of the latest ones is provided by the commercial software Agisoft Metashape (since version 1.6), previously known as Photoscan, which joins other already available open-source and commercial software tools. The present work aims to quantify the potential of the new Agisoft Metashape satellite processing module, considering that to the best knowledge of the authors, only two papers have been published, but none considering cross-sensor imagery. Here we investigated two different case studies to evaluate the accuracy of the generated DSMs. The first dataset consists of a triplet of Pléiades images acquired over the area of Trento and the Adige valley (Northern Italy), which is characterized by a great variety in terms of geomorphology, land uses and land covers. The second consists of a triplet composed of a WorldView-3 stereo pair and a GeoEye-1 image, acquired over the city of Matera (Southern Italy), one of the oldest settlements in the world, with the worldwide famous area of Sassi and a very rugged morphology in the surroundings. First, we carried out the accuracy assessment using the RPCs supplied by the satellite companies as part of the image metadata. Then, we refined the RPCs with an original independent terrain technique able to supply a new set of RPCs, using a set of GCPs adequately distributed across the regions of interest. The DSMs were generated both in a stereo and multi-view (triplet) configuration. We assessed the accuracy and completeness of these DSMs through a comparison with proper references, i.e., DSMs obtained through LiDAR technology. The impact of the RPC refinement on the DSM accuracy is high, ranging from 20 to 40% in terms of LE90. After the RPC refinement, we achieved an average overall LE90 <5.0 m (Trento) and <4.0 m (Matera) for the stereo configuration, and <5.5 m (Trento) and <4.5 m (Matera) for the multi-view (triplet) configuration, with an increase of completeness in the range 5–15% with respect to stereo pairs. Finally, we analyzed the impact of land cover on the accuracy of the generated DSMs; results for three classes (urban, agricultural, forest and semi-natural areas) are also supplied.

scholarly journals Long-term effectiveness of elderly health care voucher scheme strategies: a system dynamics simulation analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ka Chun Chong ◽  
Hong Fung ◽  
Carrie Ho Kwan Yam ◽  
Patsy Yuen Kwan Chau ◽  
Tsz Yu Chow ◽  
...  
Keyword(s):  
Primary Care ◽  
Chronic Disease ◽  
Public Sector ◽  
System Dynamics ◽  
The Elderly ◽  
Healthcare Services ◽  
Dynamics Simulation ◽  
Public And Private ◽  
The Public ◽  
The Impact

Abstract Background The elderly healthcare voucher (EHCV) scheme is expected to lead to an increase in the number of elderly people selecting private primary healthcare services and reduce reliance on the public sector in Hong Kong. However, studies thus far have reported that this scheme has not received satisfactory responses. In this study, we examined changes in the ratio of visits between public and private doctors in primary care (to measure reliance on the public sector) for different strategic scenarios in the EHCV scheme. Methods Based on comments from an expert panel, a system dynamics model was formulated to simulate the impact of various enhanced strategies in the scheme: increasing voucher amounts, lowering the age eligibility, and designating vouchers for chronic conditions follow-up. Data and statistics for the model calibration were collected from various sources. Results The simulation results show that the current EHCV scheme is unable to reduce the utilization of public healthcare services, as well as the ratio of visits between public and private primary care among the local aging population. When comparing three different tested scenarios, even if the increase in the annual voucher amount could be maintained at the current pace or the age eligibility can be lowered to include those aged 60 years, the impact on shifts from public-to-private utilization were insignificant. The public-to-private ratio could only be marginally reduced from 0.74 to 0.64 in the first several years. Nevertheless, introducing a chronic disease-oriented voucher could result in a significant drop of 0.50 in the public-to-private ratio during the early implementation phase. However, the effect could not be maintained for an extended period. Conclusions Our findings will assist officials in improving the design of the EHCV scheme, within the wider context of promoting primary care among the elderly. We suggest that an additional chronic disease-oriented voucher can serve as an alternative strategy. The scheme must be redesigned to address more specific objectives or provide a separate voucher that promotes under-utilized healthcare services (e.g., preventive care), instead of services designed for unspecified reasons, which may lead to concerns regarding exploitation.

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