Terms Of Capacity Utilization Research Articles

The system-wide effects of dispatch, response and operational performance on emergency medical services during Covid-19

In this paper, we analyze the Fire Department of New York City’s pre-hospital emergency medical services dispatch data for the period of March 20, 2019–June 13, 2019, and the corresponding Covid lockdown period of March 20, 2020–June 13, 2020. A fixed effects negative binomial model is used to estimate the heterogeneity effects of average ambulance travel or response times on the daily volume of emergency calls, year, day of the week, dispatcher-assigned medical emergency call type, priority rank, ambulance crew response, borough and an offset for missing calls. We also address the limitations of other non-parametric Covid studies or parametric studies that did not properly account for over-dispersion. When our model is estimated and corrected for clustered standard errors, fixed effects, and over-dispersion, we found that Wednesday was the only day of the week that was most likely to increase travel response time with an odd ratio of 6.91%. All grouped call types that were categorized showed significant declines in average travel time, except for call types designated as allergy and an odds ratio of 21.81%. When compared to Manhattan, Staten Island ambulance response times increased with an odds ratio of 19.05% while the Bronx showed a significant decline with an odds ratio of 31.92% advanced life support (ALS) and BLS ambulances showed the biggest declines in travel time with the exception of BLS assigned ambulance types and emergency priority rank of 6. Surprisingly, in terms of capacity utilization, the dispatch system was not as overwhelmed as previously predicted as emergency call volume declined by 8.83% year over year.

Enhanced Electrochemical Performance of Simple Electrospun Non-Woven Nickel/Carbon Nanofibers as a Functional Interlayer for Lithium-Sulfur Batteries.

Non-woven nickel/carbon nanofibers (NW(Ni/C)NFs) are developed using a facile one-pot electrospinning method as a functional interlayer for rechargeable lithium-sulfur (Li-S) batteries. The functional interlayer of NW(Ni/C)NFs is sandwiched between a sulfur cathode and the separator and acts as a shuttle inhibitor to sulfur and polysulfides. Because of the sandwiched structure and the nickel additive, the Li-S cell shows better performance in terms of capacity utilization and reversibility. When the NW(Ni/C)NFs were calcined at 900 °C with 1 g of nickel salt additive, the discharge capacity of the cells was the best, and the initial discharge capacity was 1062 mAh g-1. With 200 charge-discharge cycles at 1 C, the discharge capacity of the cells remained above 910 mAh g-1, which is about 85.7% of its initial capacity. The improvement to the cells' electrochemical performance is attributed to the 3D architecture of the NW(Ni/C)NFs as a functional interlayer and to the appropriate amount of nickel addition. This provides a good conductive network with structural stability and the migrating polysulfide reduces the "shuttling phenomenon" during the charge-discharge processes.

Model based adaptive control of a continuous capture process for monoclonal antibodies production

A two-column capture process for continuous processing of cell-culture supernatant is presented. Similar to other multicolumn processes, this process uses sequential countercurrent loading of the target compound in order maximize resin utilization and productivity for a given product yield. The process was designed using a novel mechanistic model for affinity capture, which takes both specific adsorption as well as transport through the resin beads into account. Simulations as well as experimental results for the capture of an IgG antibody are discussed. The model was able to predict the process performance in terms of yield, productivity and capacity utilization. Compared to continuous capture with two columns operated batch wise in parallel, a 2.5-fold higher capacity utilization was obtained for the same productivity and yield. This results in an equal improvement in product concentration and reduction of buffer consumption. The developed model was used not only for the process design and optimization but also for its online control. In particular, the unit operating conditions are changed in order to maintain high product yield while optimizing the process performance in terms of capacity utilization and buffer consumption also in the presence of changing upstream conditions and resin aging.

Priori Knowledge Guided Approach for Optimal Peer Selection in P2P VoD Systems

With the rise of Video-on-Demand (VoD) systems as a preferred way to distribute video content over IP networks, many research works and innovations have focused on improving the scalability of streaming systems by looking at distributed approaches such as peer-to-peer (P2P). One of the most critical aspects in P2P-assisted streaming system is the real-time resource allocation, which drives the performance of the system in terms of capacity utilization and VoD requests rejection rates. In this paper, we specifically focus on the problem of maximizing the P2P streaming system utilization by effectively alternating between different resource allocation strategies. Switching between different resource allocation strategies is guided by a run-time statistical analysis of performances against predicted content popularity pattern. A key contribution of this paper resides in effectively combining different, and potentially conflicting, performance objectives when deciding on which resource allocation strategy to use. Indeed, we use a Bayesian Fusion to select the most appropriate resource allocation strategy to deal with future content demand. With our P2P resource allocation framework, a VoD service operator can combine any number of resource allocation strategies and formulate different performance objectives that meet the requirements of its network and the content consumption behavior of its users.

Relative Scale Efficiency & Benchmarking Top Ten Selected Indian States of Textile Industry

Indian Textile & Clothing industry has been the backbone of Indian Economy ever since Indian Economy gained global recognition and has been passing through many phases of ups and downs during ancient, medieval and modern days. With its 4% approximate contribution towards Indian National Income, Second largest employment (around 42 million direct employment) generation and more than 15% in Indian Industrial Production and in total export earnings as well, it has been the focal centre of Government policy and attention. However, in terms of capacity utilization and inefficient operation, it has remained the point of concern for policy makers and economists. Present paper is an attempt to trace the magnitude of relative scale inefficiency, input and output slacks of Top Ten Indian States in the field of Textile and clothing Industry. The level of relative scale efficiency and benchmarking of major contributing Indian States in textile industry is attempted by using Input-Oriented CRS Model of DEA with carefully selected set of Inputs and Outputs under different models. And various states are considered as Decision Making Units (DMUs) to calculate Scale efficiency. The study explores the feasibility of and is an attempt on developing decision rationalization model in the benefit of Textile Industry in India.

Nickel foam as interlayer to improve the performance of lithium–sulfur battery

In this report, a porous, electronically conductive nickel foam foil (NFF), which is rolled for smooth surface, is introduced as an interlayer placed between the sulfur electrode and the separator to suppress the loss of active material and self-discharge behavior in lithium–sulfur (Li–S) systems. The electrodes are characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge test. The cell with the rolled NFF interlayer shows superior performance in terms of capacity utilization, reversibility, and enhanced rate capability. It exhibits reversible discharge capacity of 604 mAh g−1 after 80 cycles at 0.2 C, which is much higher than that of pristine sulfur without NFF (424 mAh g−1). The improvement on electrochemical performance is attributed to the 3D architecture of nickel foam foil as lithium–sulfur batteries interlayer, which can provide a good conductive network with structural stability and the porous architecture accommodating the migrating polysulfide to reduce the shuttling phenomenon during the charge–discharge processes.

Highly reversible Li/dissolved polysulfide batteries with binder-free carbon nanofiber electrodes

Conventional lithium–sulfur batteries suffer from rapid capacity fade which limits their commercialization applications. Li/dissolved polysulfide cells with binder-free, interwoven, self-standing carbon electrodes show outstanding performance in terms of capacity utilization and reversibility. To further understand this system, we present here a binder-free carbon nanofiber (CNF) paper electrode with large interspaces between fibers, low manufacturing cost, and high polysulfide loadings. The 3D interwoven structure of the CNF paper electrode allows transitions between high-order polysulfides (charged products) and lithium sulfide (discharged product) to occur within a confined environment. Crystalline Li2S is found within the large interspaces of the 3D electrode framework after the 1st discharge, avoiding the formation of dense passivation layers on the cathode. The robust porous CNF paper electrode leads to superior electrochemical performance with a reversible capacity of 1094 mA h g−1 after 80 cycles at a C/5 rate and Coulombic efficiencies above 98% with a sulfur loading of 1.7 mg cm−2. A stable reversible capacity of ∼900 mA h g−1 is obtained with a much higher sulfur loading of 5.1 mg cm−2, making this battery configuration promising for practical applications.

Local Versus Centralized Charging Strategies for Electric Vehicles in Low Voltage Distribution Systems

Controlled charging of electric vehicles offers a potential solution to accommodating large numbers of such vehicles on existing distribution networks without the need for widespread upgrading of network infrastructure. Here, a local control technique is proposed whereby individual electric vehicle charging units attempt to maximise their own charging rate for their vehicle while maintaining local network conditions within acceptable limits. Simulations are performed to demonstrate the benefits of the technique on a test distribution network. The results of the method are also compared to those from a centralized control method whereby EV charging is controlled by a central controller. The paper outlines the advantages and disadvantages of both strategies in terms of capacity utilization and total energy delivered to charging EVs.

A hierarchical planning system for energy intensive production environments

This paper describes a hierarchical production planning approach with decision support features for energy intensive industries with particular reference to a tile manufacturing factory. In the tiling industry, the facilities which contribute most to the consumption of energy (and, hence, to the production costs) are usually the kilns where the curing operation is carried out. Frequently, the kilns are also the bottleneck in terms of capacity utilization. Thus, in order to save on energy costs, a planning approach which aims at minimizing the number of active kilns throughout the year is needed besides optimizing the process design in the curing department. To achieve the latter goal, it is necessary to take into account demand fluctuations as well as detailed capacity restrictions while deciding on the lot sizes of the products and the kilns on which the products are loaded. Rather than adopting a monolithic mathematical model for developing a desirable production plan, a hierarchical approach which decomposes the problem into two sub-problems is preferred. In the first level, products and capacity are aggregated over the planning horizon to achieve an overall consideration of demand fluctuations over time. Then, the solution provided by the aggregate solution for the current planning period is disaggregated into a detailed lot sizing and loading solution. The disaggregated problem is difficult to solve and hence, a heuristic is proposed here. This planning approach is sustained by a Decision Support System which enables the elimination of possible inconsistencies in the production plan by providing an effective interaction with the decision maker.