Number Of Bays Research Articles

Theoretical study on the heat of formation of some polycyclic aromatic hydrocarbons

This paper reports the results on how structural details govern the heat of formation (ΔHf) of the catacondensed benzenoid hydrocarbons, a wide subclass of polycyclic aromatic hydrocarbons. To accomplish this goal, the influence of the molecular size (expressed through the number of six-membered rings, NR), number of bays (NB), number of coves (NC), number of fjords (NF), and molecular branching (expressed through the number of B3-type rings, NB3), as well as the position of the latter four structural features in a molecule were inspected. To obtain the ΔHf values, the semiempirical PM7 method was applied, and it showed good agreement with the existing experimental results. These structural properties affect ΔHf of these compounds differently. The strongest effect on ΔHf has NR, and it was found that ΔHf increases with increasing NR. ΔHf also increases with increasing NB3. However, when the molecular branching is moved across the molecule, it was found that ΔHf decreases, as it moves to the middle of a molecule. ΔHf of the examined compounds decreases with increasing NB, NC, and NF, and as the bay, cove, and fjord move to the middle of a molecule. When NB, NC, and NF take large values, this decrease slows down.

Graph-based solution for performance evaluation of shuttle-based storage and retrieval system

The aim of this study is to provide a graph-based solution for performance evaluation of a new autonomous vehicle-based storage and retrieval system, shuttle-based storage and retrieval system (SBS/RS), under various design concepts. By the graph-based solution, it is aimed the decision-maker (i.e. warehouse manager) evaluates a pre-defined system’s performance promptly and decides on the correct design concept based on his/her requirements from thousands of alternative design scenarios of SBS/RS. The design concepts include number of bays (NoB), aisles (NoA) and tiers (NoT) for the rack design and arrival rate of storage/retrieval (S/R) transactions to an aisle of the warehouse (AR). The performance of the system is evaluated in terms of average utilisation of lifts and average cycle time of S/R transactions. Simulation is utilised for the modelling purpose. Seven NoT, seven NoB and six AR scenarios are considered in the experiments. Hence, 294 experiments are completed to obtain the graphs. By this study, to the best of our knowledge it is the first time a graph-based solution including comprehensive design concepts of SBS/RS is presented.