Pricing storage of outbound containers in container terminals

In container yard of container terminals, a storage charge is imposed to encourage customers to limit the space required for their containers. This study addresses the storage price scheduling problem for the storage of outbound containers. The price schedule consists of the free-time limit, which is the maximum duration for a container to stay in the yard without any charge, and storage charge per day for storing a container past the free-time-limit. Empirical data suggests that the efficiency of loading operations significantly depends on the space utilized by a vessel’s outbound containers. Mathematical models are developed to determine the optimal storage price schedule in such a manner that the terminal’s total profit is maximized or the total system’s cost is minimized. Both single and multi-vessel cases are considered. Properties of the optimal solution are derived from the mathematical models and numerical experiments are conducted to validate solutions.     

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.     

Strategies for improving a long-established terminal’s performance: a simulation study of a Turkish container terminal

Due to a long-lasting increase in global trade, only interrupted by the late-2000s economic crisis, container traffic has grown dramatically. As a result, new terminals have opened and existing terminals face much higher container handling than before. In order to meet these challenges, one of the biggest container terminals in Turkey has begun to reconsider its terminal operations and to achieve improvements of its overall logistics performance. Because the factors impacting the terminal’s performance are highly interrelated, a simulation model was developed to analyze the terminal operations, to identify potential bottleneck resources and to highlight directions for the future development of the configuration and the operational control system. For a long-established terminal like the one considered in this study the options for improving the overall performance are limited by the geographical dimensions and by the existing terminal equipment. By use of the simulation model the terminal operations are evaluated under different workload scenarios and alternative configurations are tested in order to support strategic decisions on the terminal’s development.     

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 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.     

Strategic allocation of cyclically calling vessels for multi-terminal container operators

We consider a terminal operator who provides container handling services at multiple terminals within the same port. In this setting, the well-known berth allocation problem can no longer be considered for each terminal in isolation since vessel calls should be spread over the various terminals to avoid peaks and troughs in quay crane utilization, and an allocation of two connecting vessels to different terminals will generate inter-terminal container transport. In this paper, we address the problem of spreading a set of cyclically calling vessels over the various terminals and allocating a berthing and departure time to each of them. The objectives are (1) to balance the quay crane workload over the terminals and over time and (2) to minimize the amount of inter-terminal container transport. We develop a solution approach based on mixed-integer programming that allows to solve real-life instances of the problem within satisfactory time. Additionally, a practical case study is presented based on data from the terminal operator PSA Antwerp who operates multiple terminals in the port of Antwerp, Belgium. The computational results show the cost of the currently agreed schedules, and that relatively small modifications can significantly reduce the required crane capacities and inter-terminal transport.     

Successful vitrification of bovine blastocysts on paper container

Cryopreservation of bovine embryos can be performed by a variety of methods with variable degree of success. Here, we report a new, easy to perform, simple, inexpensive, and successful method for vitrification of bovine blastocysts. In vitro produced bovine blastocysts were exposed to vitrification solution (5.5 m ethylene glycol, 10% serum and 1% sucrose) in one single step for 20 s, loaded on a paper container prepared from commonly available non-slippery, absorbent writing paper, and then were directly plunged into liquid nitrogen for storage. Vitrified blastocysts were warmed by serial rinsing in 0.5, 0.25 and 0.125 m sucrose solution for 1 min each. Results showed that one step exposure of bovine blastocysts to cryoprotective agents was sufficient to achieve successful cryopreservation. Under these conditions, more than 95% of blastocysts survived the vitrification-warming on paper containers which was significantly higher than those obtained from other containers, such as electron microscope (EM) grid (78.1%), open pulled straw (OPS; 80.2%), cryoloop (76.2%) or plastic straw (73.9%). Embryo transfer of blastocysts vitrified-warmed on paper container resulted in successful conception (19.3%) and full-term live birth of offspring (12.3%) which were lower (P < 0.05) than those obtained from non-vitrified blastocysts (38.0 and 32.7%) but were comparable (P > 0.05) to those obtained from blastocysts vitrified-warmed on EM grid (23.3 and 14.2%). Our results, therefore, suggest that paper may be an inexpensive and useful container for the cryopreservation of animal embryos.     

Seaside operations in container terminals: literature overview,trends, and research directions

Seaside operations are considered the bottleneck operation in most container terminals around the world. This paper presents an in-depth updated overview of the seaside operations at container terminals and highlights current trends and developments. We review and classify scientific journal papers on container terminal seaside operations, published between 2004 and 2012. The paper also discusses and challenges the current operational paradigms on seaside operations. Lastly, the paper identifies new avenues for academic research based on current trends and developments in the container terminal industry.     

Evaluating impact of truck announcements on container stacking efficiency

Container stacking rules are an important factor in container terminal efficiency. We build on prior research and use a discrete-event simulation model to evaluate the impact of a truck announcement system on the performance of online container stacking rules. The information that is contained in the announcement, i.e., the expected departure time for an import container, can be used to schedule pre-emptive remarshall moves. These moves can then be performed when the workload is low in order to decrease the export time and the crane workload at peak times.     

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.     

容器苗质量评定指标的研究

1　引　　言苗木质量的优劣直接影响造林成活率的高低 ,也影响林木初期生长速度 .优质苗木造林后 ,根系生长能力强 ,迅速扎根 ,适应性强 ,并且生长快 ,提前郁闭成林 ,对杂草、干旱、霜冻、病虫害的抵抗能力强 .然而 ,由于苗木的形态特征比较容易评定 ,且在某种条件下可以预测苗木的造林效果 ,因此 ,以往的苗木分级几乎都是以形态指标作为评定苗木质量的唯一根据 .Ｓｕｔｔｏｎ[8] 认为 ,此种评定方法在人工造林条件影响不大的情况下还很适用 ,如果造林条件影响大 ,形态指标就不能用来确定造林效果 .自 2 0世纪 80年代以来 ,国内学者从容器苗…     

A cooperative quay crane-based stochastic model to estimate vessel handling time

Having a good estimate of a vessel’s handling time is essential for planning and scheduling container terminal resources, such as berth positions, quay cranes (QCs) and transport vehicles. However, estimating the expected vessel handling time is not straightforward, because it depends on vessel characteristics, resource allocation decisions, and uncertainties in terminal processes. To estimate the expected vessel handling time, we propose a two-level stochastic model. The higher level model consists of a continuous-time Markov chain (CTMC) that captures the effect of QC assignment and scheduling on vessel handling time. The lower level model is a multi-class closed queuing network that models the dynamic interactions among the terminal resources and provides an estimate of the transition rate input parameters to the higher level CTMC model. We estimate the expected vessel handling times for several container load and unload profiles and discuss the effect of terminal layout parameters and crane service time variabilities on vessel handling times. From numerical experiments, we find that by having QCs cooperate, the vessel handling times are reduced by up to 15 %. The vessel handling time is strongly dependent on the variation in the QC service time and on the vehicle travel path topology.     

A plastic container for rearing insects on artificial diets

Abstract

Entomology Division’s Insect Rearing Section, in Auckland, has developed an insect rearing container especially suited to use with artificial diets (Fig. 1).     

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.     

Vesicular Glutamate Transporter 1 Orchestrates Recruitment of Other Synaptic Vesicle Cargo Proteins during Synaptic Vesicle Recycling

A long standing question in synaptic physiology is how neurotransmitter-filled vesicles are rebuilt after exocytosis. Among the first steps in this process is the endocytic retrieval of the transmembrane proteins that are enriched in synaptic vesicles (SVs). At least six types of transmembrane proteins must be recovered, but the rules for how this multiple cargo selection is accomplished are poorly understood. Among these SV cargos is the vesicular glutamate transporter (vGlut). We show here that vGlut1 has a strong influence on the kinetics of retrieval of half of the known SV cargos and that specifically impairing the endocytosis of vGlut1 in turn slows down other SV cargos, demonstrating that cargo retrieval is a collective cargo-driven process. Finally, we demonstrate that different cargos can be retrieved in the same synapse with different kinetics, suggesting that additional post-endocytic sorting steps likely occur in the nerve terminal.     

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.     

Cargo Transport at Microtubule Crossings: Evidence for Prolonged Tug-of-War between Kinesin Motors

Intracellular transport of cargos along microtubules is often complicated by the topology of the underlying filament network. The fundamental building blocks for this complex arrangement are filament intersections. The navigation of cargos across microtubule intersections remains poorly understood. Here, we demonstrate that kinesin-driven cargos are engaged in a tug-of-war at microtubule intersections. Tug-of-war events result in long pauses that can last from a few seconds to several minutes. We demonstrate that the extent of the tug-of-war and the duration of pauses change with the number of motors on the cargo and can be regulated by ionic strength. We also show that dwell times at intersections depend on the angle between crossing microtubules. Our data suggest that local microtubule geometry can regulate microtubule-based transport.     

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.     

Effect of climate and type of storage container on aflatoxin production in corn and its associated risks to wildlife species

The effects of grain storage containers on aflatoxin production, and the relationship between the level of aflatoxin and the number and weight of fluorescing kernels were determined in corn (Zea maize) stored in controlled climate regimes. Two hundred and forty 100-g samples were held up to 3 mos using four types of storage containers placed in four climates. Storage containers included corn placed in metal cans, paper bags, plastic bags, and paper bags placed in plastic bags. Climates were constant during the duration of the project and included a combination of temperatures and humidities. Temperatures were 29-32 C and 14-18 C; relative humidities were 85-88% and 35-40%. In addition, corn was exposed to environmental conditions conductive for aflatoxin production and 100 g samples were randomly collected, examined under ultraviolet light for fluorescence, and then quantified for aflatoxin levels. Corn samples tested negative for aflatoxin at the beginning of the project. Main (i.e., container, climate, and month) and interactive effects were not observed. Mean levels of aflatoxin ranged from 0 to 151 microg/kg. Aflatoxin was produced regardless of type of storage container, time of storage, and climatic conditions; however, only 8% of the samples produced aflatoxin levels that exceeded 50 microg/kg. Fluorescing corn ranged from 0 to 19 kernels per sample, while aflatoxin levels ranged from 0 to 1,375 microg/kg for the same samples. No relationships were found between the number and weight of fluorescing kernels of corn and aflatoxin levels. The black light test yielded a false negative rate of 23% when in fact the aflatoxin concentrations exceeded 50 microg/kg. Therefore, quantifying fluorescing grain under UV light should not be considered a feasible alternative for aflatoxin testing of grain intended for wildlife.     

Immunogenicity of therapeutic proteins. Part 2: impact of container closures

Immunogenicity as a potential consequence of therapeutic protein administration is increasingly being scrutinized in the biopharmaceuticals industry, particularly with the imminent introduction of biosimilar products. Immunogenicity is an important safety aspect requiring rigorous investigation to fully appreciate its impact. Factors involved in product handling, such as storage temperature, light exposure, and shaking, have been implicated in immunogenicity, while container closure systems are no less important. Intended to provide a stable environment for the dosage form, container closures may also interact with a product, affecting performance and potentially enhancing immunogenicity. Glass surfaces, air-liquid interfaces, and lubricants can mediate protein denaturation, while phthalates in plastics and latex rubber are sources of extractables and leachates that may contaminate a product, causing allergic reactions and increasing immunogenicity. The manufacture of therapeutic proteins therefore requires rigorous safety evaluations not just in the context of the product, but also product containment.