scholarly journals Assessing the Impact of Virtual Standby Systems in Failure Propagation for Complex Wastewater Treatment Processes

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Fredy Kristjanpoller ◽  
Pablo Viveros ◽  
Nicolás Cárdenas ◽  
Rodrigo Pascual
Keyword(s):  
Wastewater Treatment ◽  
Production Systems ◽  
Simulation Analysis ◽  
Preliminary Treatment ◽  
Operational Characteristic ◽  
Production Forecast ◽  
Failure Propagation ◽  
Modelling Methodology ◽  
Failure Scenario ◽  
The Impact

This article proposes an original probabilistic modelling methodology named Virtual Standby (VSB), which enables a practical simulation, analysis, and evaluation of the impact on availability and reliability achieved by potential buffering policies on the performance of complex production systems. Virtual Standby (VSB) corresponds to a design and operational characteristic where some machines under a failure scenario are capable to provide for a limited time, continuity to the subsystems downstream before suffering delay which is currently not considered when assessing availability. This feature plays a relevant role on the propagation of the effect of a failure; indeed, it could prevent the propagation by guaranteeing the isolation time needed to recover from its failure, controlling and reducing the production losses downstream. A case study of the preliminary treatment process of a wastewater treatment facility (WWTF) is developed bearing in mind the systemic behaviour in the event of a failure and the specific features of each equipment. VSB is a big advantage for the representation of this complex processes because, among other things, it considers the impact of buffering policies on the perceived availability of the system. This model allows determining different production levels, with a better and easier fitting of the reliability, availability, and production forecast of the process. Finally, the comparison between the VSB simulation results with traditional procedures that do not consider the operational continuity under a failure scenario confirms the strength and precision of the proposal for complex systems.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

Optimisation and control of the inflow to a wastewater treatment plant using integrated modelling tools

1998 ◽  
Vol 37 (1) ◽  
pp. 347-354 ◽  
Author(s):  
Ole Mark ◽  
Claes Hernebring ◽  
Peter Magnusson
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pilot Project ◽  
Integrated Modelling ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
The Impact

The present paper describes the Helsingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Helsingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant. As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.

scholarly journals Review: Impacts of shade on cattle well-being in the beef supply chain

2020 ◽  
Author(s):  
Lily N Edwards-Callaway ◽  
M Caitlin Cramer ◽  
Caitlin N Cadaret ◽  
Elizabeth J Bigler ◽  
Terry E Engle ◽  
...  
Keyword(s):  
Supply Chain ◽  
Heat Stress ◽  
Beef Cattle ◽  
Production Systems ◽  
Construction Materials ◽  
Well Being ◽  
Third Party ◽  
Ambient Temperatures ◽  
Stress Susceptibility ◽  
The Impact

ABSTRACT Shade is a mechanism to reduce heat load providing cattle with an environment supportive of their welfare needs. Although heat stress has been extensively reviewed, researched, and addressed in dairy production systems, it has not been investigated in the same manner in the beef cattle supply chain. Like all animals, beef cattle are susceptible to heat stress if they are unable to dissipate heat during times of elevated ambient temperatures. There are many factors that impact heat stress susceptibility in beef cattle throughout the different supply chain sectors, many of which relate to the production system, i.e. availability of shade, microclimate of environment, and nutrition management. The results from studies evaluating the effects of shade on production and welfare are difficult to compare due to variation in structural design, construction materials used, height, shape, and area of shade provided. Additionally, depending on operation location, shade may or may not be beneficial during all times of the year, which can influence the decision to make shade a permanent part of management systems. Shade has been shown to lessen the physiologic response of cattle to heat stress. Shaded cattle exhibit lower respiration rates, body temperatures, and panting scores compared to un-shaded cattle in weather that increases the risk of heat stress. Results from studies investigating the provision of shade indicate that cattle seek shade in hot weather. The impact of shade on behavioral patterns is inconsistent in the current body of research, some studies indicating shade provision impacts behavior and other studies reporting no difference between shaded and un-shaded groups. Analysis of performance and carcass characteristics across feedlot studies demonstrated that shaded cattle had increased ADG, improved feed efficiency, HCW, and dressing percentage when compared to cattle without shade. Despite the documented benefits of shade, current industry statistics, although severely limited in scope, indicate low shade implementation rates in feedlots and data in other supply chain sectors do not exist. Industry guidelines and third party on-farm certification programs articulate the critical need for protection from extreme weather but are not consistent in providing specific recommendations and requirements. Future efforts should include: updated economic analyses of cost versus benefit of shade implementation, exploration of producer perspectives and needs relative to shade, consideration of shade impacts in the cow-calf and slaughter plant segments of the supply chain, and integration of indicators of affective (mental) state and preference in research studies to enhance the holistic assessment of cattle welfare.

scholarly journals Tanning Wastewater Treatment by Ultrafiltration: Process Efficiency and Fouling Behavior

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 461
Author(s):  
Fu Yang ◽  
Zhengkun Huang ◽  
Jun Huang ◽  
Chongde Wu ◽  
Rongqing Zhou ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Shear Rate ◽  
Membrane Surface ◽  
Filtration Efficiency ◽  
Operating Conditions ◽  
Process Efficiency ◽  
Transmembrane Pressure ◽  
Leather Industry ◽  
Pore Blocking ◽  
The Impact

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.

Governance of differential stakeholder interests in supply chains and networks

2013 ◽  
Vol 13 (2) ◽  
pp. 99-105 ◽  
Author(s):  
E.F.M. Wubben ◽  
H.J. Bremmers ◽  
P.T.M. Ingenbleek ◽  
A.E.J. Wals
Keyword(s):  
Social Sciences ◽  
Business Models ◽  
Production Systems ◽  
Stakeholder Management ◽  
Data Gathering ◽  
Health Claims ◽  
Stakeholder Dialogue ◽  
Stakeholder Interests ◽  
Multi Stakeholder ◽  
The Impact

Competing frames and interests regarding food provision and resource allocation, adding to the increased global interdependencies, necessitate agri-food companies and institutions to engage themselves in very diverse multi-stakeholder settings. To develop new forms of interaction, and governance, researchers with very different backgrounds in social sciences try to align, or at least share, research trajectories. This first paper in a special issue on governance of differential stakeholder interests discusses, first, different usages of stakeholder categories, second, the related intersubjectivity in sciences, third, an rough sketch of the use of stakeholder management in different social sciences. Social science researchers study a wide variety of topics, such as individual stakeholder impact on new business models, stakeholder group responses to health claims, firm characteristics explaining multi-stakeholder dialogue, and the impact of multi-stakeholder dialogue on promoting production systems, and on environmental innovations. Interestingly, researchers use very different methods for data gathering and data analysis.

scholarly journals USMED: broadening the impact of simulation analysis methodology

2005 ◽  
Author(s):  
R.R. Barton ◽  
L.W. Schruben ◽  
J.C. Ford ◽  
D. Hopkins ◽  
D. Goldsman ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Analysis Methodology ◽  
The Impact

Wind Farm Grid Integration Simulation Analysis of the Impact of Power System Transient Stability

2013 ◽  
Vol 805-806 ◽  
pp. 334-337
Author(s):  
Shi Wei Su ◽  
You Wei Zhou ◽  
Wei Xiong
Keyword(s):  
Power System ◽  
Wind Farm ◽  
Transient Stability ◽  
Simulation Analysis ◽  
Direct Access ◽  
Grid Integration ◽  
Access System ◽  
Wind Dispersion ◽  
The Impact ◽  
Single Set

Analysis compares the direct access to a single set of wind power systemTwo groups of wind farm access system directlyMultiple sets of wind farm access system directly And Multiple sets of wind dispersion access system's impact on power system transient stability. And compare the simulation results, Concluded that wind farm access capacity and its topology structure's influence on system transient stability.

Postcolonialism

Geography ◽  
2021 ◽  
Author(s):  
Lindsay Naylor
Keyword(s):  
Production Systems ◽  
Colonial Period ◽  
Economic Relations ◽  
15Th Century ◽  
Accumulation By Dispossession ◽  
Indigenous Groups ◽  
The 19Th Century ◽  
The Impact ◽  
British Colonies ◽  
Independence Movements

In the colonial period imperialism advanced in uneven ways across time and space globally. European exploration in the late 15th century first brought destructive, exploitative, and deadly changes to what became known as the Americas. The subjugation and elimination of Indigenous groups, which commenced during this period, created the conditions for accumulation by dispossession, enslavement (of both Indigenous groups and people stolen from Africa), plantation-style production systems, and the extraction of resources—the legacies of which still mark political, social, economic, and environmental landscapes today. Following rebellion and successful de jure (legal) independence from Europe in the late 1700s and early 1800s (starting with the radical uprising of enslaved peoples in Haiti), Western powers turned to new regions to regain such systems of control and resource extraction. In 1848, the Berlin Conference was held— also called the “Scramble for Africa,” where European powers divided the continent and created new sites of extraction. Such patterns followed in South and Southeast Asia as well as North Africa and Central Asia in the latter parts of the 19th century. As a result of these violent campaigns, there are very few places on the globe that did not sustain, at some point, a form of colonial-imperial relation. Independence movements were ongoing and by the end of the 20th century, de jure colonial control had all but disappeared. Decolonization had occurred and the global periphery entered the period of being postcolonial. Former British colonies were assembled into the Commonwealth, which changed relations from direct control and subjugation to allegiance to the Queen and for some, drastic changes in economic relations, (this had the effect of marginalizing Indigenous struggles in many of these places). Notwithstanding the legal separation of the colonies from imperial powers, de facto (in effect) colonial arrangements lingered and remain today, giving rise to a series of critiques and new ways of thinking about imperialism and the impact of colonialism, such as the theory of postcolonialism.

A Dynamic Analysis Of The Impact Of Air Pollution On The daylight Availability In An Open-plan Office In London

2021 ◽  
pp. 94-103
Author(s):  
Jiangtao Du ◽  
Steve Sharples
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Simulation Analysis ◽  
Design Stage ◽  
Design Strategies ◽  
Early Design Stage ◽  
Pollutant Deposition ◽  
Open Plan ◽  
Building Project ◽  
The Impact

The deposition of air pollutants on glazing can significantly affect the daylight transmittance of building fenestration systems in urban areas. This study presents a simulation analysis of the impact of air pollution and glazing visual transmittance on indoor daylight availability in an open-plan office in London. First, the direct links between glazing visual transmittance and daylighting conditions were developed and assessed. Second, several simple algorithms were established to estimate the loss of daylight availability due to the pollutant deposition at the external surface of vertical glazing. Finally, some conclusions and design strategies to support facade planning at the early design stage of an urban building project were developed.

Sign in / Sign up

Export Citation Format

Share Document