Green Operations Research Articles

Constant and Green Mode Operation Technique in Flyback and Push-Pull DC-DC Converter

Abstract: The high frequency switching causes switching losses and reduces the efficiency of converters. Therefore, operating the DC-DC converters with lower frequencies at light loads reduces the switching losses significantly. Variable frequency switching is generally defined as Green mode operation. The green mode control method is obtained from high efficiency over the entire load range. This method is also called variable frequency control and it changes the switching frequency according to the load condition. At full load conditions, the controller increases the switching frequency to decrease switching ripple and ripple-related conduction loss. When the load decreases, the controller decrease switching frequency to diminish switching loss and increase switch life cycle. In this paper, the flyback and push-pull converter topologies are simulated using MATLAB/Simulink and the results obtained from the variable switching converter are compared with the results obtained from constant switching frequency. Keywords: Green Mode Operation, Flyback Converter, Push-Pull Converter, Variable Switching Frequency, Constant Switching Frequency.

Green Supply Chain Performance Measurement using Green SCOR Model in Agriculture Industry: A Case Study

The agriculture industry has proliferated in the last decades, increasing the envi­ron­mental footprint. Several development concepts include integrating the ecological aspect into the supply chain to reduce environmental degradation. In implementing the idea, companies in the agriculture industry need to evaluate their performance in the environmental area. This measure­ment uses the Green Supply Chain Operations Reference (GSCOR) Model that provides its entire supply chain aspect. This study demonstrates that the enable parameter criterion, which shows the magnitude of employee management toward environmental requirements, significantly impacts supply chain performance. Other criteria are also critical, such as a plan that considers every entity's usage and a source that considers the supply of the entities. The performance measurement produces a 6.357 value in the yellow color category with an average condition in the company. It produces three key performance indicators (KPI), such as water usage, percentage hazardous materials in inventory, and percentage hazardous waste, with a red classification that should be improved.

Effect of Pd-Sensitization on Poisonous Chlorine Gas Detection Ability of TiO2: Green Synthesis and Low-Temperature Operation.

Ganoderma lucidum mushroom-mediated green synthesis of nanocrystalline titanium dioxide (TiO2) is explored via a low-temperature (≤70 °C) wet chemical method. The role of Ganoderma lucidum mushroom extract in the reaction is to release the ganoderic acid molecules that tend to bind to the Ti4+ metal ions to form a titanium-ganoderic acid intermediate complex for obtaining TiO2 nanocrystallites (NCs), which is quite novel, considering the recent advances in fabricated gas sensing materials. The X-ray powder diffraction, field emission scanning electron microscopy, Raman spectroscopy, and Brunauer–Emmett–Teller measurements etc., are used to characterize the crystal structure, surface morphology, and surface area of as-synthesized TiO2 and Pd-TiO2 sensors, respectively. The chlorine (Cl2) gas sensing properties are investigated from a lower range of 5 ppm to a higher range of 400 ppm. In addition to excellent response–recovery time, good selectivity, constant repeatability, as well as chemical stability, the gas sensor efficiency of the as-synthesized Pd-TiO2 NC sensor is better (136% response at 150 °C operating temperature) than the TiO2 NC sensor (57% at 250 °C operating temperature) measured at 100 ppm (Cl2) gas concentration, suggesting that the green synthesized Pd-TiO2 sensor demonstrates efficient Cl2 gas sensing properties at low operating temperatures over pristine ones.

Pengukuran kinerja green manufacturing pada industri tahu sumedang untuk meningkatkan kinerja terhadap lingkungan menggunakan GSCOR dan LCA

The application of an environmentally sound industry is one of the environmental conservation issues and a global issue in the industry. The application of an environmentally sound industry can be implemented in the Green Manufacturing system. The tofu industry in the production process uses a high volume of water, resulting in a high volume of liquid waste, which can pollute the environment. The problem with the Sari Kedelai industry is that there has not been a performance measurement on the environment and an analysis of the resulting impact. This study aims to measure the performance of Green Manufacturing with the GSCOR (Green Supply Chain Operations Reference) and LCA (Life Cycle Assessment) methods as well as formulate suggestions for improvements to the Sari Kedele industry in the context of implementing Green Manufacturing. The results of performance measurement using the GSCOR method in the Sari Kedele industry has a value of 79.78 which was included in the good category. Environmental impact analysis is assessed with a focus on GHG emissions (Greenhouse Gases) that uses LCA with an ISO 14040 approach resulting in a GHG emission value of CO2-eq/kg tofu of 3.7107.

ISO 8685 compliant contractual ship-loading export facility: bauxite sampling plant process design and equipment selection for chemical sampling

The paper discusses the process design and mass balance for the minimum and maximum design case to illustrate the ISO 8685 compliance of a 2-year-running barge loading payment station sampling plant. The plant samples -100 mm, export quality, bauxite material from a barge-loading conveyor delivering 10 kton/h at 5.4 m/s. The green field operation does not know the Coefficient of Variation or the Size Range Factor as required inputs to calculate the Number of Primary Increments and Minimum Gross Sample Mass required. Therefore, informed assumptions were made given performance data of a neighboring sampling system that is in operation for over a decade. Without the available variation and size factor data the ISO-compliant scheme design could not commence. Where this data is not available for green field projects, it poses a risk that plant designs may not be compliant where variabilities could exceed assumptions on the input parameters. The system is designed for various barge carrying capacities with lot size in mass. Operational quality assurance however requires samples more frequently and therefore sublot periods are 4 hourly time based. ISO 8685 compliance is achieved with sample increments taken at maximum throughputs and barge sizes to determine the time-based interval. At reduced throughputs, the fixed time interval regime results in the minimum ISO requirements to be exceeded and tied in well with client overall quality incentives. Primary sample increments from a tailored cross belt sampler are crushed automatically in the sampling plant to 25 mm and then to 6mm using two stages of double roll crushers. The sample is then subdivided through secondary and tertiary sampling to produce a composite 4-hourly chemical sample. The 4-hourly sublot samples are collected in an ergonomic 4-way carousel with each composite sample representing 1-hour barge loading production— allowing the client quality assurance insights into their blending facility performance.

Heat flux in chains of nonlocally coupled harmonic oscillators: Mean-field limit.

We consider one-dimensional systems of all-to-all harmonically coupled particles with arbitrary masses, subject to two Langevin thermal baths. The couplings correspond to the mean-field limit of long-range interactions. Additionally, the particles can be subject to a harmonic on-site potential to break momentum conservation. Using the nonequilibrium Green's operator formalism, we calculate the transmittance, the heat flow, and local temperatures for arbitrary configurations of masses. For identical masses, we show analytically that the heat flux decays with the system size N as 1/N regardless of the conservation or not of the momentum and of the introduction or not of a Kac factor. These results describe, in good agreement, the thermal behavior of systems with small heterogeneity in the masses.

Impact of fintech and green finance on environmental quality protection in India: By applying the semi-parametric difference-in-differences (SDID)

This research study is one of the significant to offer an inclusive investigation of the impact of green finance correlated policies by applying text analysis approach and panel data from 28 states and 8 union territories between 2010 and 2020. The paper uses the SDID and illustrates that overall, India's green finance associated with policies have directed a substantial decrease in industrial CO2 emissions during the study period. Furthermore, the paper determined that the Fintech growth pays to the reduction of SO2 (sulfur dioxide) emissions and positively influences environmental safety and investment enterprises. India is a great competitor worldwide in green finance strategy operation, and controllers need to accelerate the design of green finance products and boost the volume of financial institutions to provide green credit facilities. Though minimalizing the risk fintech stances, policymakers should inspire fintech's to take part in environmental quality protection inventiveness that encourages green consumption actively.

The killed Brox diffusion

We are proposing to study a diffusion in random environment confined in bounded interval. As for many standard diffusions, we build in natural way a stochastic process with bounded domain, but with addition of considering a random environment. We carry out this construction using the Brox diffusion and applying well-known diffusion theory in a quenched fashion, which is a natural way to deal with random environment. The outcome of this procedure is an object that we may call the killed Brox diffusion. Since the generator of this process is initially an ill-posed expression we develop a Sturm–Liouville theory for one-dimensional second-order differential operators with white-noise coefficients. Our first main result is to give a close form of the Green operator associated to the generator, i.e., the inverse of the generator. We do so by setting the Lagrange identity in this context. Then, we give explicit expressions in quenched form of the probability density function of the process; such an object is given theoretically in terms of the spectral decomposition using the eigenvalues and eigenfuntions of the infinitesimal generator of the diffusion. Moreover, we characterize the eigenvalues and eigenfunctions using some integro-differential equations.

Profit distribution and stability analysis of joint distribution alliance based on tripartite evolutionary game theory under the background of green and low carbon.

Joint distribution is an advanced logistics organization model for improving the quality and efficiency of express logistics industry and achieves high-quality development of logistics, but the distribution of common profit has always been a key obstacle to the effective development of joint distribution. Based on the background of green and low carbon, this paper explores a fairer and more reasonable profit distribution scheme. The profit game between the government and the two types of member enterprises is analyzed. By focusing on how the government plays a role in inducing the joint distribution alliance to bring the green and low-carbon requirements into the profit distribution, the strategy evolution process of the three parties, the factors affecting the profit distribution and the stability of alliance are discussed through the establishment of "government-member enterprise A-member enterprise B" tripartite evolutionary game model. Finally, the evolutionary game model is numerically simulated based on system dynamics. It is found that (1) it is necessary for the government to guide and motivate the alliance to create internal incentives and constraints. The effect of government subsidies and rewards to member enterprises is greater than the penalties for member enterprises. (2) The member enterprises are likely to conspire together to defraud government subsidies and rewards, carry out "free riding" and other speculative activities, which makes it necessary for the government and the alliance to establish supervision mechanism, information disclosure mechanism, and property rights protection system. (3) The willingness of member enterprise to positively cooperate will increase with the increase of the additional benefit coefficient, the proportion of profit distribution and the importance of environmental benefit factor; and will decrease with the increase of the cost of promoting green distribution operations.

Do stock markets value green operations? Evidence from India

PurposeThis study aims to examine the impact of green operation (measured using the energy intensity of its operations) on the value of corporate firms in stock markets. The authors also examine the channel of such an impact and its implication on a firm's financing choices.Design/methodology/approachThe authors conduct various univariate and multivariate regression analyses on a panel of all non-financial Indian firms listed on the National Stock Exchange from 2010 through 2018. The authors use the sensitivity of investments to the cash flows model to test the financial constraints hypothesis.FindingsThe authors’ analysis shows a positive relationship between energy efficiency (firms that consume a lesser amount of energy per unit of sale) and the value of firms in the stock market. The authors empirically attribute this greater valuation to the lesser volatility of stock returns, measured by the standard deviation of daily stock returns. Finally, the authors observe that investments in energy-efficient firms are less sensitive to their internal cash flows.Practical implicationsThe results suggest that less green firms face greater constraints in accessing finance from external sources and, therefore, depend more on internal than external capital to finance their investments. Hence, managers of such firms can ease their financing pressures by making their operations greener.Originality/valueIn this study, the authors examine the implications of green operations on the financing choices of firms. This aspect of going green is important because managers will have enough incentives to invest in green technologies as that would increase their access to external finance and, hence, decrease their financial constraints.

Integral representations in the complex plane and iterated boundary value problems

Fundamental solutions to differential operators lead to integral operators providing integral representation formulas for solutions to related differential equations. Proper modifications of the fundamental solutions result in integral operators which are related to certain boundary value problems. For complex partial differential operators of arbitrary order in the plane, fundamental solutions are achievable by properly integrating the Cauchy kernel. Particular such complex model differential operators are the polyanalytic and the polyharmonic operators. A hierarchy of integral operators is available for these model operators leading to polyanalytic Cauchy–Schwarz and to polyharmonic Green, Neumann, Robin, and hybrid Green integral operators. The theory is supplemented here by constructing a new polyanalytic Pompeiu (Pompeiu–Vekua) integral operator of any order adjusted to (iterated) Neumann boundary conditions.

Green Operating Room—Current Standards and Insights From a Large North American Medical Center

Green Operating Room—Current Standards and Insights From a Large North American Medical Center

Power Grid Low Carbon Collaborative Planning Method Using Improved Cat Swarm Optimization Algorithm in Edge Cloud Computing Environment

The current power grid planning mostly realizes the calculation and analysis based on the factors of operation reliability or operation economy, but low-carbon green operation has become the main melody of power system development. Aiming to support the green and reliable operation of the power grid, this paper proposes a power grid low-carbon collaborative planning method based on improved cat swarm optimization algorithm. First, the carbon emission characteristics of the whole cycle of power grid construction are analyzed on the edge side, and a power grid planning model including environmental, economic, and reliability is constructed; on the cloud side, the cat swarm optimization algorithm is improved based on quantum mechanics and chaotic algorithm to achieve efficient solution to the power grid low-carbon planning model, which can support the stable and sustainable operation. Finally, the simulation experiment is realized based on IEEE 39 bus system. In this experiment, the construction cost and carbon emission of the proposed collaborative planning method are 23 million yuan and 2.28 t/MWh, respectively, which can reduce carbon emission while optimizing the construction cost and maintaining the low-carbon and stable operation.

An environmental management system in seaports: evidence from Malaysia

ABSTRACT Seaports face significant environmental challenges in their role as hubs for logistics activities, particularly since ships are significant contributors to energy consumption, global warming and air and marine pollution. The environmental pressures facing ports has led to the emergence of the green port concept. Port Klang is the largest port in Malaysia, characterised not only by significant container throughput, but also by significant congestion issues, emissions and pollution. These characteristics led to the selection of Port Klang, the nation’s major seaport, as a case study for this analysis of the variables most relevant in the effective implementation of the green port concept and subsequent research into how this green seaport concept influences a seaport’s future competitiveness. To achieve these aims, the Analytic Hierarchy Process (AHP) has been employed. The findings of the analysis suggest that environmental quality, the use of energy and resources, waste handling and habitat quality and greenery are the critical influential factors required for establishing green port hub status and that then port competitiveness is most significantly affected by green operations, sustainable equipment, resources management and cost efficiency at seaports.

Innovative Logistics Practices: Performance Assessment of Third-party Logistics Services Providers in Malaysia

In the contemporary business global sphere, it is so problematic, if not impossible, for an organization to be competitively deprived of working in alliance, closely with external associates. The idea of Supply Chain Management, (SCM), arose in this track and strives to optimally manage the physical goods and/or services. Logistics is the key competitive factor in the manufacturing sector because of the innovative models’ variants and options. For instance, in Malaysia, the manufacturing sector is a major contributor to the annual GDP, hence, there is a need for sustainable technology that can project significant business operations and supply chain management impacts. But this is far from being the case in the contemporary. Based on the increasing logistics benefits, the importance of the assessment of logistics efficiency and impact is attracting increased consideration. Green Logistics (GL) involves not only the delivery of green products or services to customers but also the inclusive logistics flow of items from cradle to grave in addition to reverse logistics. Numerous green events and operations have been instigated, such as manufacture scheduling and network construction. This article aimed at investigating the innovative logistics practices relationship with the operations of third-party logistics service providers in Malaysia. To achieve this, the study engages a structured questionnaire survey. 256 questionnaire was retrieved out of 333 questionnaires distributed electronically and 27 questionnaires were rejected based on some parallel errors and 229 questionnaires was eventually analyzed This is 69% of the questionnaire. In the analysis, SPSS version 20 was utilized. The outcome showed that selection of vehicle type and procurement on quality, cost, and environmental impacts as the main feature of innovation in sustainability. Innovative green logistics serve as a moderating factor in the relationship between 3PLs service provider’s key performance factors and green logistics in the Manufacturing industry of Malaysia. Hence, it fulfills one of the key economic growth activities or operations under strategic thrust 2 of SPV2030.

Agent‐based simulation of cross‐contamination of Escherichia coli O157:H7 on lettuce during processing and temperature fluctuations during storage in a produce facility. Part 2: Model implementation

AbstractAn agent‐based simulation was developed to represent the spatial and temporal Escherichia coli O157:H7 cross‐contamination dynamics in a processing facility for fresh‐cut romaine lettuces using NetLogo. An extension was added to the model to predict E. coli O157:H7 growth due to temperature abuses in a cold storage facility. A user‐friendly interface was created to follow variations in model outputs. The number of contaminated bags and lettuce contamination levels were computed and visualized. Experimental data of cross‐contamination from literature was used to describe the facility and validate the model. The key factor affecting cross‐contamination in the process is the free chlorine (FC) concentration dose rate. The number of contaminated bags per batch decreases nonlinearly as FC is added to the flume tank. The contamination level in the shredded lettuces increases linearly with initial microbial load or the initial contamination probability on lettuce heads. Both the level and probability of contamination in the facility's environment alter the number of contaminated bags. Batch size influences the number of contaminated bags when the first incoming lettuce batch is contaminated. The smaller the batch size the smaller number of contaminated bags. Storage room temperature fluctuations (13 and 19°C and 8 and 12°C) show the importance of real‐time monitoring to avoid pathogen growth and number of contaminated bags. This work provides insight on applications of agent‐based modeling approach using NetLogo to visualize cross‐contamination in fresh‐cut leafy green processing operations. It analyzes cross‐contamination and its impact on processing performance by studying the effect of mitigation strategies.Practical applicationsTo support ready‐to‐eat leafy greens postharvest operations, this work investigated the benefits of using visualization to develop strategies to prevent produce cross‐contamination along processing and the effect of temperature abuse during storage. Output from the model can be used in Quantitative Management Risk Assessment (QMRA) applications. By developing a simulation‐based decision support system, the safety of processing and storage steps of fresh‐cut leafy greens are investigated. Pathogen cross‐contamination and growth models are integrated to observe impacts of varying contamination levels in incoming produce and equipment surfaces, concentrations of free chlorine in the wash water, and storage temperatures on the number of contamination bags over time. Computational experiments study a pilot plant of Romaine lettuces contaminated with E. coli O157:H7. Results indicate that the key factor affecting cross‐contamination is the chlorination concentration dose rate in the wash water. Other factors include the level of contamination on the incoming lettuce heads or in the facility environment (equipment). Storage room temperature fluctuations showed the importance of real‐time monitoring to avoid microorganism growth and thus prevent an increase in the number of contaminated bags.

On mean Green operator and Eshelby tensor of hollow cylinders with length from infinite tubes to flat rings in isotropic elastic media

Using the (RT-IRT) Radon transform and inversion formula method, the author has previously reported the exact formal expressions for the mean shape function (mSF) of a finite solid cylinder of general aspect ratio in any infinite medium and for the related mean Green operator (mGO) and mean Eshelby tensor (mET) in cases of isotropic elastic-like (including dielectric-like) linear properties. Nearly exact solutions were obtained provided an accurate analytical approximation of an elliptic integral. Using the same RT-IRT method, the present work addresses the case of hollow cylinders with finite length in same isotropic property contexts. From examining the general formal mSF expression (and comparing with the limits of infinitely long cylinders and infinitely flat platelets) a simple accurate approximation is provided for the mSF, mGO and mET of "thin" hollow cylinders, from tubes to rings what covers a wide range of practical situations. The same expression being shown to hold on the thick side limit, the conjecture that it may be relevant over the whole thickness range is questioned.

Singular Green operators in the edge algebra formalism

We give a new description of the class of singular Green operators introduced by Grubb in the study of parameter-dependent boundary value problems, employing the concept of operator-valued symbols introduced by Schulze in the framework of pseudodifferential operators on manifolds with edges.

Towards the optimal orchestration of steerable mmWave backhaul reconfiguration

Future generations of mobile networks will require increased backhaul capacity to connect a massive amount of small cells (SCs) to the network. Since having an optical connection to each SC might be infeasible, mmWave links are an interesting alternative due to their large available bandwidth. An advantage of a wireless backhaul is that the topology can be reconfigured to adapt to changing traffic demands, new operator policies, or to rapidly overcome network failures. In this work, we investigate the problem of orchestrating the reconfiguration of mmWave wireless backhaul networks with mechanically steerable antennas assuming green backhaul operation where nodes are turned off when not in use. The orchestration involves scheduling and coordinating the powering on/off of nodes, the rotation of antennas to achieve alignment for link establishment, and setting up and tearing down links to minimize packet loss during the reconfiguration. We model the problem as a Mixed Integer Linear Program (MILP) for optimal orchestration and propose a sub-optimal reduced MILP for larger instances. Numerical results for different topologies using a realistic traffic trace indicate that optimizing reconfiguration orchestration can significantly reduce packet loss in comparison to a straightforward reconfiguration approach, enabling a smooth transition between target mmWave backhaul topologies.

Reverse Logistics Performance Indicators for the Construction Sector: A Building Project Case

While the performance evaluation of reverse logistics (RL) practices in the construction sector is crucial, it is seemingly limited compared to that in the manufacturing sector. As the project life cycle in the construction sector is typically long, effective coordination among the stakeholders is needed to integrate RL into each phase of the project life cycle. This paper proposes a new model of RL for the construction industry, incorporating the dimensions, elements, and, most importantly, indicators needed for the evaluation of RL performance. The model was initially derived from the extant literature. It was then refined through (1) focus group discussion, by which suggestions pertinent to the proposed model were collated from academics and practitioners, and (2) judgments by academics and practitioners to validate the model. The validated model includes 21 indicators to measure RL performance, spanned throughout the green initiation, green design, green material management, green construction, and green operation and maintenance phases. The paper offers a new method for how RL can be adopted in the construction industry by proposing an innovative model that will benefit stakeholders in the construction industry.