Unloading Time Research Articles

Modelling of the Acetification Stage in the Production of Wine Vinegar by Use of Two Serial Bioreactors

In the scope of a broader study about modelling wine acetification, the use of polynomial black-box models seems to be the best choice. Additionally, the use of two serially arranged bioreactors was expected to result in increased overall acetic acid productivity. This paper describes the experiments needed to obtain enough data for modelling the process and the use of second-order polynomials for this task. A fractional experimental design with central points was used with the ethanol concentrations during loading of the bioreactors, their operation temperatures, the ethanol concentrations at unloading time, and the unloaded volume in the first one as factors. Because using two serial reactors imposed some constraints on the operating ranges for the process, an exhaustive combinatorial analysis was used to identify a working combination of such ranges. The obtained models provided highly accurate predictions of the mean overall rate of acetic acid formation, the mean total production of acetic acid of the two-reactor system, and ethanol concentration at the time the second reactor is unloaded. The operational variables associated with the first bioreactor were the more strongly influential to the process, particularly the ethanol concentration at the time the first reactor was unloaded, the unloaded volume, and the ethanol concentration when loading.

Hangar Utility Simulation as a Traffic Flow Density Scenario in Giwangan Market Yogyakarta

Giwangan Market as a fruit and vegetable wholesale market needs to be evaluated, organized and improved in the services. Currently, its development has undergone many changes. The hangar, which is the main block for loading and unloading fruits and vegetables, has shifted its function in several places. With the addition of semi-permanent buildings on the sides of hangars, the loading and unloading area are reduced and the entry and exit routes for vehicles are not functioning properly. 86% of vehicles with a tonnage of 2000 - 5000 kg that entered the Giwangan market were in the market for an average of 89.9 minutes. It is because the vehicle is not only loading and unloading but also selling in the market. So that other vehicles cannot load and unload. This study aims to measure the system performance which is estimated from the average actual travel time and the loading and unloading time of vehicles in the system. The alternative of rearranging hangar used is based on the development plan of the Giwangan Market Management Office. The simulation model has been verified and validated. The first rearrangement scenario is that all traders are moved to a new location (slaughterhouse). Second, the flow in and out of the hangar is one-way. Thus, the average vehicle in the system becomes 54.44 minutes and the hangar utility is 16.13% as an indicator that the hangar performance can be improved by increasing the number of vehicles capable of loading and unloading.

An effective approach for the dual-resource flexible job shop scheduling problem considering loading and unloading

Many manufacturing systems need more than one type of resource to co-work with. Commonly studied flexible job shop scheduling problems merely consider the main resource such as machines and ignore the impact of other types of resource. As a result, scheduling solutions may not put into practice. This paper therefore studies the dual resource constrained flexible job shop scheduling problem when loading and unloading time (DRFJSP-LU) of the fixtures is considered. It formulates a multi-objective mathematical model to jointly minimize the makespan and the total setup time. Considering the influence of resource requirement similarity among different operations, we propose a similarity-based scheduling algorithm for setup-time reduction (SSA4STR) and then an improved non-dominated sorting genetic algorithm II (NSGA-II) to optimize the DRFJSP-LU. Experimental results show that the SSA4STR can effectively reduce the loading and unloading time of fixtures while ensuring a level of makespan. The experiments also verify that the scheduling solution with multiple resources has a greater guiding effect on production than the scheduling result with a single resource.

An optimal solution policy to an integrated manufacturer-retailers problem with normal distribution of lead times of delivering equal and unequal-sized batches

In this paper a single-manufacturer multi-retailer integrated model is developed by extending the ideas of two single-vendor single-buyer integrated models, where Normal distribution of lead times of delivering equal- and/or unequal- sized batches of a lot was considered. In the original models, the mean lead time of delivering batches was assumed to be equal to sum of the times of setting up the used machine, processing of the first batch and inspection, loading, transfer and unloading of that batch. However, delivery time of each of the batches from the second to the last of the same lot is only concerned with the time of inspection, loading, transfer and unloading of that batch, not on the additional time of setting up the machine and processing of the first batch. As a result, extra inventories are accumulated during delivering those batches. In our model the mean lead time is assumed to be the mean of the times of inspection, loading, transfer and unloading of a batch. The supply chain flow is synchronized by transferring the lot either only with equal-sized batches or only with unequal-sized batches, and generating a notification point to the manufacturer to start processing of a next lot in time so that the mean lead times of batches is maintained. Then an optimal solution policy to that model is presented along with an algorithm and it is illustrated with numerical example problems. The benefit of this policy is highlighted by comparative studies on numerical example problems and significant reduction in the minimal total cost for a single-manufacturer 5-retailer numerical problem is found.

Flupyradifurone reduces nectar consumption and foraging but does not alter honey bee recruitment dancing

Foraging is essential for honey bee colony fitness and is enhanced by the waggle dance, a recruitment behavior in which bees can communicate food location and quality. We tested if the consumption of nectar (sucrose solution) with a field-realistic concentration of 4 ppm flupyradifurone (FPF) could alter foraging behavior and recruitment dancing in Apis mellifera. Foragers were repelled by FPF. They visited the FPF feeder less often and spent less time imbibing sucrose solution (2.5 M, 65% w/w) with FPF. As a result, bees feeding on the FPF treatment consumed 16% less nectar. However, FPF did not affect dancing: there were no effects on unloading wait time, the number of dance bouts per nest visit, or the number of dance circuits performed per dance bout. FPF could therefore deter bees from foraging on contaminated nectar. However, the willingness of bees to recruit nestmates for nectar with FPF is concerning. Recruitment can rapidly amplify the number of foragers and could overcome the decrease in consumption of FPF-contaminated nectar, resulting in a net inflow of pesticide to the colony. FPF also significantly altered the expression of 116 genes, some of which may be relevant for the olfactory learning deficits induced by FPF and the toxicity of FPF.

Integrated planning of train schedule template and container transshipment operation in seaport railway terminals

This paper investigates the transshipment operations between vessels and trains in seaport rail terminals. In order to get a more effective transshipment plan, the schedule plan of trains and the transshipment plan of containers among vessels, yards, and trains are determined simultaneously. To this end, a mixed integer programming (MIP) model is proposed to integrate the two sub-problems with the objective of minimizing the total operation cost, in which the service time window and unloading time requirement of trains are considered. It is demonstrated that some variables in the model can be relaxed without influencing the optimal result. Moreover, a set of valid inequalities are introduced to tighten the constraints. The result experiments show that the enhanced model can be solved more effectively. Then, extensive experiments have been conducted to analyze the influence of several factors, including the handling capacity, the yard capacity, and the value of unit cost. The results report that the handling capacity shows a significant effect on the performance of the transfer plan, and increasing the storage cost of import containers leads to a more effective transshipment plan.

Mathematical modeling of grain mictures in optimatization tasks of the dump bunker’s kinematic parameters

Typically, in the technological processes of agricultural production, machines and equipment are used, where self-loading containers, bunkers, operating on the principle of natural gravitational leakage of friable, grain materials are used for transportation or overload of bulk materials. But the use of such components is justified only for use in the process of harvesting maize ears in the swaths and provided that the start is fed to the collecting hopper of the combine harvester, and after filling it is overloaded in the technological transport by the principle of “dump truck”. When trying to go beyond these limitations to increase transportation or overload of bulk materials, there are objective difficulties that arise from the freezing and sticking of the bulk material in the absence of the gravitational leakage phenomenon. As part of the study described in this article, an analytical description of overcoming these difficulties is proposed. It is based on the fact that the analytical equations of motion of a grain mixture, such as quasi-liquids, allow taking into account the bunker’s turn around the fastening axis during unloading of the grain mixture. This analytical approach allows us to further substantiate the kinematic parameters of self-propelled bunkers of harvesting machines. The mode of the technological process of unloading the dump of the hopper with grain material with a minimum unloading time is analyzed. This means that the obtained scientific result in the form of the equation of motion of a grain mixture, as quasi-liquids, on a sloping plane is interesting from the theoretical point of view. From the practical point of view, the analytical equations of motion of the grain mixture, such as quasi-liquids, allow us to determine the conditions of use of combine harvesters in the technology of plant production. Thus, the applied aspect of using the obtained scientific result is the possibility of improving the typical technological process of harvesting agricultural crops. This is a prerequisite for the transfer of technological solutions to agro-industrial production.

Study on the influence of pre-stress time-characteristic on microstructure transformation in GH process

Firstly, simulation is used to analyze the temperature curve in pre-stress hardening grinding (PSHG). Then, according to the start and the end time of martensitic transformation, three time nodes are selected to study the pre-stress time characteristic; they are 1 s, 3 s, and 7 s after grinding. The influence of pre-stress on the initial temperature and content of martensite transformation in cooling is analyzed; the results indicate the content of martensite increases over the pre-stressed unloading time. To test the theory, experiments of PSHG with different unloading times are carried out. The microstructure of the grinding hardening surface is observed and explored by scanning electron microscopy (SEM). Then, the SEM images are binarized to get the martensite content on the hardening surface. The experimental results show martensite content is consistent with the theoretical analysis. Lath martensite and flake martensite can also be found in these pictures. Flake martensite slightly increases while unloading at 7 s, as it forms at a lower temperature. So the pre-stress time characteristic influences both the martensite content and the morphology of martensite formed.

A sustainable vendor-buyer inventory system considering transportation, loading and unloading activities

The increasing amount of worldwide carbon emissions has caused global warming, instigating governments to implement carbon policies such as the carbon cap-and-trade policy to achieve sustainable environmental development. This study aims to determine an optimal policy for the integrated system, which minimizes the total integrated cost while keeping ecological issues in mind. It discusses the carbon emissions (direct and indirect) generated by both parties (vendor and buyer) that involve freight forwarding activities. Loading and unloading activities involved in the process of both parties are considered. Lead-time is considered as a function of the production time, loading and unloading time, transportation time, and in-transit time. Logistics costs are a function of the weight of a product, distance traveled, fuel price, and fuel consumption. A proper solution algorithm was developed to find the optimal decision variables (order quantity, number of shipments, safety factor, lead-time, and total emission quantity), which minimize the total cost. A numerical example and sensitivity analysis are performed to reveal the efficiency of the proposed model by using Matlab12a. The findings of the study revealed that the parameters impact the decision variables significantly. In addition, managerial insights have also been drawn for decision-makers.

ОПРЕДЕЛЕНИЕ ОЧЕРЕДНОСТИ ОБСЛУЖИВАНИЯ ПОДВИЖНОГО СОСТАВА В ТРАНСПОРТНЫХ УЗЛАХ НА ОСНОВЕ КРИТЕРИЯ ОПТИМАЛЬНОСТИ

The article describes the methodology for determining the sequence of services based on the criterion of optimality. This approach reduces the waiting time for loading and unloading of rolling stock. The service priority model is used to describe a coordinated transportation process. The given numerical experiment reflects the validity of the model and algorithm

Multi-Bale Handling Unit for Efficient Logistics

This paper presents a design for a feedstock logistics system to supply a bioenergy plant located in the Southeast USA, specifically Piedmont, a physiographic region covering part of five states (VA, NC, SC, GA, and AL). The design uses a perennial grass (switchgrass) as the feedstock. Harvest is done with a round baler, and round bales are stored in single-layer ambient storage in satellite storage locations. New technology, 20-bale racks, was designed as the multi-bale handling unit. The analysis shows how proper design of the interactions between the several unit operations in a “logistics chain” can be used to minimize average delivered cost for the feedstock required for 24/7 operation. Racks are loaded at the satellite storage and delivered by hauling contractors hired by the plant and controlled by a “Feedstock Manager” at the plant to insure approximately the same number of loads are received each day. Single-bale handling at the plant is eliminated, thus the truck unload time is reduced and truck productivity (tons/day) is increased. At-plant handling and storage in 20-bale racks increases plant receiving facility productivity, and gives a reduction in plant cost to supply a continuous steam of material for 24/7 operation.

Uncertain four-dimensional multi-objective multi-item transportation models via GP technique

In this paper, a new type of four-dimensional multi-objective multi-item transportation problem is established using uncertain theory. We formulate and derive the expected value goal programming model and chance-constrained goal programming model based on the uncertain theory, where unit transportation cost, availabilities, capacities of conveyances, demands, unit transportation time, unit loading and unloading time are represented as uncertain matrices. Based on some properties of uncertain theory, the expected value goal programming model and chance-constrained goal programming model are transformed into the corresponding deterministic equivalents form via the soft computing technique, i.e., generalized reduced gradient technique named by LINGO-14.0. After that, a real-life numerical example is given to illustrate the performance of the models. Finally, the sensitivity analysis of the proposed model is presented through chance-constrained goal programming method with respect to different confidence levels.

Characteristics of unloading damage and permeability evolution of sandstone under hydro-mechanical coupling

A triaxial unloading mechanical test is conducted on sandstone considering different initial confining pressures and unloading rates under the effect of hydraulic coupling. The energy evolution of sandstone unloading failure is studied, and the influences of the initial confining pressure and unloading rate on the deformation characteristics and permeability evolution of sandstone are discussed. It is found that the initial confining pressure and unloading rate have a significant impact on the axial and radial strains of the sandstone, and the radial deformation is more sensitive to the unloading process. The energy dissipation of the sandstone sample increases with the increase of the confining pressure and is nonlinearly correlated to the unloading time. The permeability during the unloading deformation of the sandstone decreases with the increase in the initial confining pressure, indicating that the initial confining pressure of unloading has an inhibitory effect on the permeability of the sandstone. The permeability decreases with the increase in unloading rate, indicating that the faster the increase in the unloading rate, the greater the dissipated instantaneous elastic energy, which is accumulated and released during failure. The higher the degree of fracture in the sample, the larger the peak value of permeability.

Phase-Specific Predictors of Countermovement Jump Performance That Distinguish Good From Poor Jumpers.

Krzyszkowski, J, Chowning, LD, and Harry, JR. Phase-specific predictors of countermovement jump performance that distinguish good from poor jumpers. J Strength Cond Res 36(5): 1257-1263, 2022-The modified-reactive strength index (RSImod) is commonly examined during the countermovement vertical jump (CMJ) to assess neuromuscular characteristics (i.e., explosiveness, fatigue, adaptation, etc.) of an athlete. However, both phase-specific variables explaining RSImod and corresponding differences between good and poor jumpers are not well understood in trained populations. This study sought to (a) identify predictors of RSImod during the CMJ based on phase-specific temporal and rate of force development (RFD) variables, and (b) identify differences in those predictors between performers with high and low RSImod performances from a sample of collegiate male basketball players (n = 22; 20 ± 2 years; 1.99 ± 0.06 month; 93.8 ± 7.5 kg). Subjects performed 3 maximal effort CMJ trials while ground reaction force data was recorded using 2 force platforms. Phase-specific temporal and RFD variables were calculated and entered into separate stepwise regression models using backward elimination to identify predictors RSImod. Individuals were then categorized into high (n = 11; RSImod = 0.68 ± 0.10) and low (n = 11; RSImod = 0.48 ± 0.04) RSImod groups according to the overall median RSImod (RSImod = 0.55). Independent t-tests (α = 0.05) were conducted and supplemented by Cohen's d effect sizes (d ≥ 1.2, large) to compare groups relative to significant predictors identified by the linear regression models and related variables. The temporal regression model (R2 = 0.530) retained unloading time and concentric time, whereas the RFD regression model (R2 = 0.429) retained unloading RFD and braking RFD. The high RSImod group exhibited significantly greater RSImod scores (d = 2.51, p < 0.001) and jump heights (d = 1.58, p < 0.001), shorter times to takeoff (d = 1.27, p = 0.007) and concentric times (d = 1.51, p = 0.002), and a greater braking RFD (d = 1.41, p = 0.005) than the low RSImod group. Individuals targeting enhanced CMJ performance may consider exploring strategies or interventions to develop quicker unloading and concentric phases and increasing eccentric RFD abilities.

Effects of Housing, Short Distance Transport and Lairage on Meat Quality of Finisher Pigs.

Simple SummaryKnowledge of stressful stimuli is a fundamental aspect to improve and evaluate animal welfare. Animal stressors vary in function of, for example, housing, climate and handling technique. That is why it is important to investigate animal welfare in different circumstances (e.g., type of housing, climate and region). Belgian pig production is based on the Piétrain breed which is associated with the halothane gene and hence with the genetic susceptibility to stress. In pigs, there is a negative correlation between stress in the last few hours of their life and the final meat quality. In our research we investigated several potential parameters that could influence the meat quality of pork. We can conclude that numerous parameters on farm, during transport and in slaughterhouse influence meat quality. Specifically, reducing lung lesions by vaccination during raising, no mixing of pigs during the transport process, sufficient lairage time and transporting no extreme muscled pigs can improve meat quality. Adequate control and application of guidelines on farm, transport and slaughterhouse level are necessary to improve animal welfare, but also to reduce deterioration of meat quality important for the financial aspect and the appreciation of the consumer.Transport and associated handling can have adverse effects on pig welfare and meat quality. The purpose of the study was to determine (the variation of) effects of farm management, climate parameters, transport and lairage conditions on the meat quality of fattening pigs, heterozygous for the halothane gene. A total of 4763 fattening pigs were transported from 1 farm to a commercial slaughterhouse (distance 110 km) in 121 transports. From 2404 carcasses, carcass temperature and pH were measured 45 min post-mortem; 48 hours post-mortem pH, electrical conductivity, drip loss and meat color were registered. During the raising period sex, conditions at weaning (purchased or not as piglet, vaccination against mycoplasma) and (type of) pen during fattening (i.e., from about 22 kg to 105 kg) were registered to relate with pork quality. Transport season, weather parameters, regrouping or not during loading, transport combination (truck, trailer and driver), transport compartment and transport conditions (loading density, transport duration and unloading time) were monitored. At the slaughterhouse, duration of lairage and carcass conformation were followed up to examine correlations with meat quality parameters. Effects of farm management, climate parameters during transport, transport and slaughterhouse conditions on pork quality were demonstrated. Specifically, reducing lung lesions by vaccination during raising, no mixing of pigs during the transport process, sufficient lairage time and transporting no extreme muscled pigs can improve meat quality.

Influence of time-lagged unloading paths on fracture behaviors of marble using energy analysis and post-test CT visualization

Underground excavation usually results in the decrease of horizontal stress in the front of the working face, which may trigger the occurrence of rock bust hazards. Examining rock failure under confining pressure unloading conditions is necessary to reveal the fracture mechanism of rock mass subjected to stress disturbance. Although many investigations have studied the rock mechanical behaviors during unloading, the time-lagged triaxial unloading paths on the rock fracturing mechanisms are still poorly understood. Triaxial unloading experiments and the post-test CT scanning technique were conducted on fine-grained marble samples under different unloading conditions. The stress–strain behaviors, energy evolution characteristics, and the fracture pattern of samples were analyzed. The results indicate that obvious features at various stages can be identified from the deformation history curve of the elastic strain energy (Ue), total strain energy (U), and dissipated energy (Ud). U, Ue, and Ud almost all increase with sample deformation at the time duration stage, and the elastic energy and dissipation energy curves slightly decrease and increase again. After the unloading point, the dissipation energy sharply increases and the incremental rate of elastic energy becomes lower. The elastic strain energy increases with the increasing unloading rate for samples at the confining pressure unloading point and failure point, and it is influenced by the time-lag effect of confining pressure. The crack pattern in the CT images depends on the triaxial unloading rate and time effect, which is in good agreement with the energy dissipation and release analysis. The unloading strategy has an effect on the energy conversion during triaxial unloading tests; in other words, energy dissipation and release are dependent on the unloading rate and time.

Integrated cross-dock door assignment and truck scheduling with handling times

In a cross-dock, commodities are unloaded from incoming trucks, consolidated according to their destinations, and then loaded into outgoing trucks with little or no storage in between. In this paper, we address an integrated cross-dock door assignment and truck scheduling problem to simultaneously determine the assignment and scheduling of incoming trucks to inbound doors and outgoing trucks to outbound doors, with the objective of minimizing the total time to process all trucks. We consider handling times to be truckload and door dependent and to include unloading, transfer and loading times of commodities. We propose two mathematical programming formulations and two hybrid metaheuristics to solve the problem. We report the results of computational experiments to assess the performance of the formulations and algorithms on a set of benchmark instances.

Influence of unloading time on the residual curvature of a part after conjugate bending of a sheet billet on rolls with an elastic coating

The influence of the viscous properties of elastoplastic materials on the springing during unloading of parts bent according to the conjugate scheme on a two-roll machine with an elastic coating of the lower roll is studied. Keywords bending, sheet metal, springing, unloading time, viscosity coefficient. nurzak@mail.ru

Performance evaluation of a carousel configured multiple products flexible manufacturing system using Petri net

This study presents a schematic approach to model, simulate and analyze the overall performance of an FMS, comprising a carousel layout surrounded by manufacturing and assembly cells capable to deliver a variety of multiple products. All manufacturing and assembly cells are consisting of multiple multifunctional production and assembly machines, served by material loading and unloading robots, connected through a material transporting conveyor. Inter-cellular and intra-cellular routing flexibility are employed in the system through production resources operational and breakdown modes. Colored Petri net tools are used to develop a compact, editable and deadlock-free flexible manufacturing system model reveals important information about dynamic behavior and system performance measures e.g.; throughput, mean cycle time, and work-in-process (WIP) with reference to material handling and supply system, production resources reliability and process execution input variables. Variation in input factors namely mean machining and assembly time, material loading and unloading time, number of operations between failure, repair time, parts inter-arrival time, conveyor speed and buffer capacity have shown a substantial effect on the system performance. The results indicate successful applicability of colored Petri net tools for modelling, simulation, and evaluation of carousel configured multiple products flexible manufacturing system. Further, the optimal solution represents a deep relationship between the different production modes and responses to maximize the performance of a carousel configured multiple products FMS.

Indentation Deformation of a Cu47.5Zr19Hf28.5Al5 Bulk-Metallic Glass-Matrix Nanocomposite

In this work, we study the indentation deformation of a Cu47.5Zr19Hf28.5Al5 bulk-metallic glass-matrix composite and characterize the effects of the indentation-loading rate and the holding time at the peak-indentation load. For the same peak-indentation load, increasing the holding time and/or decreasing the indentation-loading rate cause the increase of the indentation depth. There exists the "bulge" of the unloading curve at the onset of the unloading for small indentation-loading rates. The Vickers hardness is a monotonically increasing function of the indentation-loading rate for the same peak-indentation load. For the indentations with the same loading and unloading time of 30 s and without an intermediate stage at the peak-indentation load, the Vickers hardness of the Cu47.5Zr19Hf28.5Al5 bulk-metallic glass-matrix composite decreases with the increase of the indentation load. The strain energy dissipated through plastic deformation during the indentation is a power-law function of the indentation load with a power index of 3/2, and the energy ratio (total energy/plastic energy) linearly increases with the depth ratio (residual indentation depth/maximum indentation depth).