Inbound container storage price competition between the container terminal and a remote container yard

With the rapid development of global ocean transportation, storage space in container terminals is becoming a scarce resource. Hence, the terminal yard only performs as a temporary storage facility for inbound cargos. A storage charge is levied for inbound cargos that stay longer than a free storage time (called free-time-limit). After the free-time-limit, customers may move cargos from the terminal yard to a remote container yard where the storage price is lower than that in the terminal. This paper proposes inbound container storage pricing game models between the container terminal and a remote container yard. Two cases are considered: (1) the inbound container’s dwell time is random and follows a probability distribution function; (2) the inbound container’s dwell time is sensitive to the storage prices. The primary objective of this paper is to analyze the storage pricing behavior and competition outcomes of the container terminal and the remote container yard. A number of insights and analysis are provided.     

A novel approach to yard planning under vessel arrival uncertainty

Many container terminals in the world adopt the consolidated yard planning strategy, where containers to be loaded into the same vessel are stacked in groups. This has been a good strategy because when a vessel is loading, yard cranes will be stationed at these locations, and the trucks shuttle between the quay cranes and the yard cranes almost in a conveyor belt fashion. These locations are optimally chosen such that no two groups of containers are stacked in close vicinity if they are to be loaded simultaneously. However, when there is a change in vessel arrival schedule, it may cause congestion of trucks at yard locations where groups of containers in near vicinity are loading simultaneously. While the Robust Optimisation community may suggest having a robust plan—a plan that is immune to uncertainty, in this paper, we will like to find a solution that allows us to change easily when uncertainty reveals—a plan that is nimble. While the optimum solution for the nimble plan could be intractable, we explore various heuristics that enable us to find good solutions.     

The storage capacity expansion and space leasing for container depots

Positioning empty containers is one of the most effective ways to solve the container imbalance problem and is affected by the capacity of depots. A shipping company will be more competitive if the depot capacity is large. This study provides a decision tool for planning the expansion of depot capacity. Mathematical models are utilized to minimize the total relevant costs that include the capacity expansion cost, storage space leasing cost, inventory holding cost, container leasing cost, and positioning cost. The problem is formulated as a mixed integer program. Then, we develop a heuristic algorithm that is based on Lagrangian relaxation. Computational experiments are conducted to evaluate the performance of the proposed algorithm.     

Added-value of mosquito vector breeding sites from street view images in the risk mapping of dengue incidence in Thailand

Dengue is an emerging vector-borne viral disease across the world. The primary dengue mosquito vectors breed in containers with sufficient water and nutrition. Outdoor containers can be detected from geotagged images using state-of-the-art deep learning methods. In this study, we utilize such container information from street view images in developing a risk mapping model and determine the added value of including container information in predicting dengue risk. We developed seasonal-spatial models in which the target variable dengue incidence was explained using weather and container variable predictors. Linear mixed models with fixed and random effects are employed in our models to account for different characteristics of containers and weather variables. Using data from three provinces of Thailand between 2015 and 2018, the models are developed at the sub-district level resolution to facilitate the development of effective targeted intervention strategies. The performance of the models is evaluated with two baseline models: a classic linear model and a linear mixed model without container information. The performance evaluated with the correlation coefficients, R-squared, and AIC shows the proposed model with the container information outperforms both baseline models in all three provinces. Through sensitivity analysis, we investigate the containers that have a high impact on dengue risk. Our findings indicate that outdoor containers identified from street view images can be a useful data source in building effective dengue risk models and that the resulting models have potential in helping to target container elimination interventions.     

An analytical model for designing yard layouts of a straddle carrier based container terminal

In designing a yard layout for a container terminal several decisions have to be made. In this paper we propose a model which provides decision support for the design of yard layouts of terminals at which straddle carrier are used. We assume that straddle carriers are used for the horizontal transport and the stacking of containers. For the proposed model we develop estimates for the expected cycle distances of straddle carriers. In this case, we distinguish between cycles to landside facilities and to the quay. Numerical results are presented for several parameter settings. For instance, we present results for a comparison of layouts where the rows in the block are orientated parallel with layouts where the rows are orientated perpendicularly to the quay.     

A Novel Device for the Collection, Storage, Transport, and Delivery of Beneficial Insects, and its Application to Ophraella communa (Coleoptera: Chrysomelidae)

A multi-use device was developed for the collection, short-term storage, transport, and delivery of Ophraella communa (Coleoptera: Chrysomelidae), a biological control agent of common ragweed, Ambrosia artemisiifolia. The device is made from a 125-ml plastic specimen container that can hold O. communa adults or pupae. When used as an aspirator, insect collection and counting times are reduced. O. communa adults and pupae can be stored inside the container at 3°C with median survival of 41 and 21 days, respectively. A cotton wick saturated with water or a 5% sugar solution nourishes insects during transport and the container design minimizes insect mortality by providing an optimum microclimate during insect storage and transport. Designed to protect insects from rainfall and to limit encounters with predators and parasites, the containers can be used for field releases of O. communa adults and pupae. Although the container has been designed and tested for O. communa, it is highly versatile and could possibly be used with a variety of insect species.     

Container loading and unloading scheduling for a Mobile Harbor system: a global and local search method

Mobile Harbor (MH) is a type of mobile floating port system with an on-board crane for off-shore container handling capability. Due to its unique operational features, it creates a new type of operational scheduling problem. Container loading and unloading sequence schedule for the MH on-board crane is one such problem. An optimal schedule should minimize the on-board crane’s moves in a stem-to-stern direction while satisfying MH’s stability constraint. This paper presents a mathematical programming model to formally define the problem, and two heuristic methods, Genetic Algorithm (GA) method and local search method, are developed. Experimental results show that both GA and the local search method generate solutions of similar quality when the stability constraint is loose and that the local search method is not effective in finding a feasible solution for problems with a tight stability constraint.     

Effectiveness of two systems for transporting equine semen

The storage and transport of cooled, liquid semen is an effective way of facilitating the use of desirable stallions for breeding mares located on distant farms. The Equitainer System is the most widely used transport container and it has been shown that it is possible to ship semen in this container and obtain good conception rates. However, the cost of Equitainers is high, and stud-farms that ship large quantities of semen have tended to rely on cheaper alternatives, even though little documentation exists concerning their reliability, especially under extreme temperature conditions. Two different containers for transporting equine semen (the Equitainer and a styrofoam box) were compared in their effectiveness at maintaining semen quality (i.e. sperm motility and plasma membrane integrity) during 24 h of storage. The transport containers were stored at 2 different environmental temperatures, i.e., room temperature (20 degrees C) and 37 degrees C. Thirty-seven ejaculates from 10 Standardbred stallions (3 to 6 samples per stallion) were examined. Sperm function and plasma membrane integrity were assessed using a Mika Motion Analyzer and a fluorescein stain (Calcein AM/Ethidium homodimer) in fresh diluted semen that had been stored for 24 h at room temperature (20 degrees C). Another 18 ejaculates from 5 stallions were examined using methods described above, but the transport boxes were kept at a high environmental temperature (37 degrees C). After storage at room temperature, there was no significant difference in total sperm motility and frequency of spermatozoa with an intact plasma membrane between the 2 types of transport boxes. A significant difference was seen in linear sperm motility, with the Equitainer being the better container. However, a significant difference was also seen in average path velocity, with the styrofoam box being the better container. After storage at 37 degrees C, the Equitaner maintained semen quality better. A significant difference was seen in total sperm motility, average path velocity, lateral head displacement and frequency of spermatozoa with an intact plasma membrane between the 2 types of transport boxes. Although, both transport containers were satisfactory when used under normal conditions. The Equitainer seemed superior under more extreme temperatures and during longer transport periods (> 24 to 30 h).     

Household salt for retrospective dose assessments using OSL: signal integrity and its dependence on containment,sample collection,and signal readout

The aim of this work was to determine how a latent optically stimulated luminescence (OSL) signal in irradiated household salt is preserved under various ambient conditions, from the time of exposure to the time of signal readout. The following parameters were examined: optical fading in fluorescent light and under darkroom conditions (red light), thermal stability of the OSL signal during storage in a light-tight container, optical fading in representative container types, and sensitization effects of the OSL signal in exposed household salt. Furthermore, the influence of grain mixing within the saltshaker or salt container was studied by determining the dose gradient within typical salt packages. Finally, the signal integrity of salt irradiated under field conditions in a village in Belarus contaminated by Chernobyl fallout was investigated. The results show that the OSL signal in household salt is preserved in large cardboard box containers, but not in white plastic salt containers or in small portion bags used in, e.g., fast food restaurants. Furthermore, the continuous wave blue OSL signal in household salt does not fade significantly during storage up to 140 days. On the contrary, the signal appears to slowly increase during storage (“inverse fading”). Field tests of two different salt containers (with and without black tape to block light) located in Belarussian households confirmed that the signal is preserved in white plastic salt containers when they are covered with extra light-shielding material.     

Water Level Flux in Household Containers in Vietnam - A Key Determinant of Aedes aegypti Population Dynamics

We examined changes in the abundance of immature Aedes aegypti at the household and water storage container level during the dry-season (June-July, 2008) in Tri Nguyen village, central Vietnam. We conducted quantitative immature mosquito surveys of 171 containers in the same 41 households, with replacement of samples, every two days during a 29-day period. We developed multi-level mixed effects regression models to investigate container and household variability in pupal abundance. The percentage of houses that were positive for I/II instars, III/IV instars and pupae during any one survey ranged from 19.5-43.9%, 48.8-75.6% and 17.1-53.7%, respectively. The mean numbers of Ae. aegypti pupae per house ranged between 1.9-12.6 over the study period. Estimates of absolute pupal abundance were highly variable over the 29-day period despite relatively stable weather conditions. Most variability in pupal abundance occurred at the container rather than the household level. A key determinant of Ae. aegypti production was the frequent filling of the containers with water, which caused asynchronous hatching of Ae. aegypti eggs and development of cohorts of immatures. We calculated the probability of the water volume of a large container (>500L) increasing or decreasing by ≥20% to be 0.05 and 0.07 per day, respectively, and for small containers (<500L) to be 0.11 and 0.13 per day, respectively. These human water-management behaviors are important determinants of Ae. aegypti production during the dry season. This has implications for choosing a suitable Wolbachia strain for release as it appears that prolonged egg desiccation does not occur in this village.     

Decision support based automatic container sequencing system using heuristic rules

Container terminals in seaports constitute interfaces between the seaborne transport and transport-over-land of goods in global transport chains. The loading and unloading of containers are performed using quay cranes (QCs), which is the most important equipment for handling servicing vessels at a container terminal. Following tremendous growth in global container transshipments, terminals are facing increasing demand. Terminals at Shanghai are equipped with Tandem Lift which can lift two 40’ containers simultaneously to improve the efficiency of the QCs. A reasonable container combinations of Tandem Lift and container operation sequence are required to improve the servicing of vessels, meanwhile the dual cycling container operation of quay cranes has to be investigated. This paper presents a two-stage mathematical model and two-level heuristic algorithm for planning the container operation sequence using Tandem Lift in a feasible computational time. Based on the proposed methodology, a decision support system, called the Tandem Lift Container Sequence System (TLCSS). A case study of Shanghai Shengdong International Port Company (SSICT) proves that consideration of the container sequence with Tandem Lift dramatically shortens servicing time of vessels with the TLCSS.     

Stability of containerized urban street trees

Trees are usually grown in containers in the nursery until they reach a certain size, whereupon they are transplanted to a permanent location. Infrastructure development has often led to the removal of large trees. To maintain lush foliage and trees of a size that benefit urban ecology, trees can be grown in containers. Containerized trees can be moved from one location to another, and this relocation does not require root pruning or crown-size reduction. The drawback to having trees in containers is the small and confined volume of the container, which limits tree root development and thus affects containerized tree stability. The objective of this study was to understand the failure mechanisms for and the effect of the root dimensions on the stability of containerized trees. Therefore, small-scale stability model tests were conducted which were verified using numerical and analytical models. The results identified two failure modes that were likely to occur: tree overturning and container overturning. The mode of failure was dependent on the root dimensions. When the trees had extended their roots deep into the container, the whole container would overturn in the event of failure due to increased root confinement and shear resistance of the soil. On the other hand, the main failure mechanism when there was shallow root development was the uplifting of the tree from the container while the container remained upright. The results from numerical and analytical models were consistent with those obtained during the small-scale model stability tests.     

Effects of transport container and ambient storage temperature on motion characteristics of equine spermatozoa

This study was conducted to compare the cooling rates and storage temperatures within equine semen transport containers exposed to different ambient temperatures, and to evaluate the ability of these containers to preserve spermatozoal motility following 24 h of storage under these conditions. In Experiment 1, nonfat dried milk solids, glucose, sucrose, equine semen extender was divided into seven 40-mL aliquots and loaded into seven different semen transport containers: Equitainer I, Equitainer II, Equitainer III, ExpectaFoal, Bio-Flite, Lane STS, and Equine Express. After containers were loaded, they were subjected to one of three ambient storage temperatures: 1) 22 degrees C for 72 h, 2) -20 degrees C for 6 h followed by 22 degrees C for 66 h, or 3) 37 degrees C for 72 h. Cooling rates and storage temperatures of semen extender in each container were monitored with thermocouples and a chart recorder. In Experiment 2, semen from each of three stallions (3 ejaculates per stallion) was diluted to 25 x 10(6) spermatozoa/mL with semen extender, divided into 40 mL aliquots and loaded into transport containers as in Experiment I. Containers were subjected to one of three ambient storage conditions: 1) 22 degrees C for 24 h, 2) -20 degrees C for 6 h, followed by 22 degrees C for 18 h, or 3) 37 degrees C for 24 h. After 24 h of storage, spermatozoal motion characteristics (percentage of motile spermatozoa; MOT, percentage of progressively motile spermatozoa; PMOT, and mean curvilinear velocity; VCL) were evaluated using a computerized spermatozoal motion analyzer. Significant interactions were detected among storage conditions and semen transport containers for the majority of the temperature endpoints measured. When exposed to temporary ambient freezing conditions, the lowest temperatures attained by samples in containers ranged from -2.8 to 0.8 degrees C. Lowest temperature samples attained was not correlated (P > 0.05) with spermatozoal motility under any ambient condition. However, time below 4 degrees C was highly correlated (P < 0.05) with a reduction in spermatozoal motility. Mean cooling rates from 20 degrees C to 8 degrees C did not correlate with spermatozoal motility, except when containers were exposed to temporary freezing conditions. No container cooled samples below 6 degrees C in 22 degrees C or 37 degrees C environments except for the ExpectaFoal, in which samples fell below 4 degrees C under all ambient conditions. Ambient temperature affected MOT, PMOT and VCL of semen stored in all containers (P < 0.05) except for the Equitainer II in which motion characteristics remained high and were similar among all ambient temperatures (P > 0.05). Results suggest that stallion semen may be able to tolerate a wider range of cooling rates and storage temperatures than previously considered safe.     

The effect of shade on the container index and pupal productivity of the mosquitoes Aedes aegypti and Culex pipiens breeding in artificial containers

Abstract The aim of this study was to assess whether certain attributes of larval breeding sites are correlated with pupal productivity (i.e. numbers of pupae collected per sampling period), so that these could be used as the focus for control measures to enhance control efficiency. Therefore, the objectives were to identify the months of highest pupal productivity of Aedes aegypti (L.) and Culex pipiens L. (Diptera: Culicidae) in an urban temperate cemetery in Argentina where artificial containers of < 6 L (flower vases) were the predominant breeding habitats, to compare various measures of the productivity of sunlit and shaded containers and to determine whether the composition of the containers affected pupal productivity. Over a period of 9 months, 200 randomly chosen water‐filled containers (100 sunlit and 100 shaded), out of ～ 3738 containers present (～ 54% in shade), were examined each month within a cemetery (5 ha) in Buenos Aires (October 2006 to June 2007). In total, 3440 immatures of Cx pipiens and 1974 of Ae. aegypti were collected. The larvae : pupae ratio was 10 times greater for the former, indicating that larval mortality was greater for Cx pipiens. Both mosquito species showed a higher container index (CI) in shaded than in sunlit containers (Ae. aegypti: 12.8% vs. 6.9% [χ² = 17.6, P < 0.001]; Cx pipiens: 6.3% vs. 1.8% [χ² = 24, P < 0.001]). However, the number and the density of immatures per infested container and the number of pupae per pupa‐positive container did not differ significantly between sunlit and shaded containers for either species. Therefore, the overall relative productivity of pupae per ha of Ae. aegypti and Cx pipiens was 2.3 and 1.8 times greater, respectively, in shaded than in sunlit areas as a result of the greater CIs of containers in shaded areas. Neither the CI nor the number of immatures per infested container differed significantly among container types of different materials in either lighting condition. The maximum CI and total pupal counts occurred in March for Ae. aegypti and in January and February for Cx pipiens. The estimated peak abundance of pupae in the whole cemetery reached a total of ～ 4388 in the middle of March for Ae. aegypti and ～ 1059 in the middle of January for Cx pipiens. Spearman’s correlations between monthly total productivity and monthly CI were significant at P < 0.001 for Ae. aegypti (r_s = 0.975) and P < 0.01 for Cx pipiens (r_s = 0.869). Our findings indicate that the efficacy of control campaigns against the two most important mosquito vectors in temperate Argentina could be improved by targeting containers in shaded areas, with maximum effort during species‐specific times of year when pupal productivity is at its peak.     

Environmental Sustainability of Fluid Milk Delivery Systems in the United States

Beverage producers in the United States choose packaging based on cost and consumer preference. Monolayer high‐density polyethylene (HDPE) and gable‐top carton containers have long dominated the U.S. fluid milk market, but pressure for more sustainable packaging is increasing. We present a broad discussion on environmental sustainability of 18 fluid milk containers through life cycle assessment. Because different container types require unique milk processing, distribution, and disposal and incur or avoid milk losses, fluid milk delivery systems (FMDSs) are evaluated, rather than containers in isolation. By assessing FMDSs, a complete measure of containers’ environmental sustainability was obtained. Despite conservative assumptions about milk losses, differences in container size, milk processing, distribution, and container recycling, pair‐wise cradle‐to‐grave comparisons of FMDSs show there are no superior FMDSs. But, 500‐ to 1,000‐milliliter FMDSs are potentially superior to ≥half gallon if they prevent milk losses. Thus, the future of FMDSs in the United States depends on the industry's ability to prevent distribution (12%) and consumption milk losses (20% to 35%). Farm‐gate‐to‐grave comparisons showed that chilled HDPE FMDSs are superior to other plastic and chilled paperboard FMDSs for climate‐change impact, but the result is inconclusive for chilled HDPE to ambient (unrefrigerated) paperboard or plastic pouch FMDS comparisons. Plastic pouch FMDSs show potential to reduce nonrenewable fossil energy, but need to be recyclable. Ambient FMDSs are superior to chilled FMDSs for water depletion. Eight‐ounce paperboard FMDSs are superior to 8‐ounce plastic FMDSs. Thus, alternative FMDSs may improve environmental sustainability of the U.S. postfarm fluid milk supply chain.     

Dengue Outbreak in Mombasa City,Kenya, 2013–2014: Entomologic Investigations

Dengue outbreaks were first reported in East Africa in the late 1970s to early 1980s including the 1982 outbreak on the Kenyan coast. In 2011, dengue outbreaks occurred in Mandera in northern Kenya and subsequently in Mombasa city along the Kenyan coast in 2013–2014. Following laboratory confirmation of dengue fever cases, an entomologic investigation was conducted to establish the mosquito species, and densities, causing the outbreak. Affected parts of the city were identified with the help of public health officials. Adult Ae. aegypti mosquitoes were collected using various tools, processed and screened for dengue virus (DENV) by cell culture and RT-PCR. All containers in every accessible house and compound within affected suburbs were inspected for immatures. A total of 2,065 Ae. aegypti adults were collected and 192 houses and 1,676 containers inspected. An overall house index of 22%, container index, 31.0% (indoor = 19; outdoor = 43) and Breteau index, 270.1, were observed, suggesting that the risk of dengue transmission was high. Overall, jerry cans were the most productive containers (18%), followed by drums (17%), buckets (16%), tires (14%) and tanks (10%). However, each site had specific most-productive container-types such as tanks (17%) in Kizingo; Drums in Nyali (30%) and Changamwe (33%), plastic basins (35%) in Nyali-B and plastic buckets (81%) in Ganjoni. We recommend that for effective control of the dengue vector in Mombasa city, all container types would be targeted. Measures would include proper covering of water storage containers and eliminating discarded containers outdoors through a public participatory environmental clean-up exercise. Providing reliable piped water to all households would minimize the need for water storage and reduce aquatic habitats. Isolation of DENV from male Ae. aegypti mosquitoes is a first observation in Kenya and provides further evidence that transovarial transmission may have a role in DENV circulation and/or maintenance in the environment.     

Differences in preservation of canine chilled semen using different transport containers

In the present study, the effect of three different containers in the preservation of dog chilled semen, during 24, 48 and 72h was evaluated. Weekly sperm pools of different dogs were obtained, during 10 consecutive weeks. Semen samples were diluted in egg-yolk-Tris-fructose extender and stored in a Styrofoam box, a common Thermos flask and an Equitainer. Progressive motility, morphology and sperm membrane integrity were examined in semen aliquots taken daily from each container during the 3 days of storage. Additionally, integrity of the acrosome and sperm plasma membranes, determined by PI/Fitc-PSA staining was assessed at 48 and 72h of storage. At 24h no differences were observed between the three containers for the evaluated parameters. At 48h samples kept in the Equitainer presented a higher progressive motility than samples kept in the Thermos. At 72h, progressive motility was higher in the Equitainer than in the other two containers. Only samples kept in the Equitainer maintained similar levels of progressive motility between 24 and 72h. Membrane integrity assessed by eosin-nigrosin deteriorated over the 72h period, whereas functional membrane integrity determined by the hypoosmotic swelling test was independently affected by type of container (the Equitainer) kept a higher percentage of sperm cells with intact membrane) and time of storage (a decrease of membrane integrity between 24 to 72h). Staining with PI-Fitc-PSA allowed the detection of differences between containers but not between the two studied storage periods (48 and 72h). The results indicated that the use of the Equitainer is preferable when transporting chilled dog semen for more than 48h.     

A scheduling problem for a novel container transport system: a case of mobile harbor operation schedule

Mobile Harbor (MH) is a movable floating platform with a container handling system on board so that it can load/discharge containers to/from an anchored container ship in the open sea. As with typical quay crane operation, an efficient schedule for its operation is a key to enhancing its operational productivity. A MH operation scheduling problem is to determine a timed sequence of loading/discharging tasks, assignment of MH units to each task, and their docking position, with an objective of minimizing the makespan of a series of incoming container ships. A mixed integer programming model is formulated to formally define the problem. As a practical solution method to the problem, this paper proposes a rule-based algorithm and a random key based genetic algorithm (rkGA). Computational results show that the rkGA method produces a better-quality solution than the rule-based method, while requiring longer computation time.     

A new approach to the Container Positioning Problem

In this paper the Container Positioning Problem is revisited. This problem arises at busy container terminals and requires one to minimize the use of block cranes in handling the containers that must wait at the terminal until their next means of transportation. We propose a new Mixed Integer Programming model that not only improves on earlier attempts at this problem, but also better reflects reality. In particular, the proposed model adopts a preference to reshuffle containers in line with a just-in-time concept, as it is assumed that data is more accurate the closer to a container’s scheduled departure the time is. Other important improvements include a reduction in the model size, and the ability of the model to consider containers initially at the terminal. In addition, we describe several classes of valid inequalities for this new formulation and present a rolling horizon based heuristic for solving larger instances of the problem. We show that this new formulation drastically outperforms previous attempts at the problem through a direct comparison on instances available in the literature. Furthermore, we also show that the rolling horizon based heuristic can further reduce the solution time on the larger of these instances as well as find acceptable solutions to much bigger, artificially generated, instances.     

A chassis exchange terminal to reduce truck congestion at container terminals

Truck congestion for container terminals seems to be a worldwide unwanted phenomenon. In this paper we present and analyze a chassis exchange terminal concept to reduce the congestion. The terminal works as a kind of extended gate of a group of traditional container terminals. During the night containers are collected from these container terminals using chassis (or trailers). In daytime these containers on chassis are then collected and exchanged with export containers also on chassis. By exchanging the chassis we avoid extra handling of containers. As connecting and disconnecting to a chassis can be done in a short time, the chassis exchange terminal increases handling capacity substantially during peak hours. In this paper we analyze the concept for the Maasvlakte container terminals in Rotterdam. We investigate both the effect on waiting time, as well as the environmental effects.