Method to estimate the consumption of ice during fish storageMéthode d'estimation de la consommation de glace au cours de l'entreposage du poisson

The amount of ice needed for the storage of fresh fish is economically important especially in warm climates. It is affected by the insulation of the fish boxes and containers and by the procedures used in the handling and transporting of iced fish. This paper describes a simple method to estimate ice consumption during fish storage. The method was tried with plastic boxes containing hake (Merluccius hubbsi) when ice losses were caused by heat transfer due only to natural convection. It can be used also to test any kind of box or container, and can give valuable indications with other heat transfer conditions.     

Est-ce l'aspect du transport maritime, ou terrestre, qui doit primer dans la conception des conteneurs des marchandises périssable?

The author recounts the qualities that have to be met by autonomous containers if they are to perform satisfactorily during sea transport: methods of loading goods into the container, hoisting the container onboard ship, difficulties in ensuring onshore maintenance, controlling satisfactory onboard operation, the most frequent breakdowns occuring with refrigerating machinery, and the possibilities of interventions by crews. The unreliability of the autonomous container has contributed to the boom in the use of isothermal containers.     

Effects of food container depth on the quality and yield of superchilled and iced Atlantic salmon

Insulated food containers of different sizes are commonly used to preserve the quality of perishable fresh fish products during transport and storage. The aim of the study was to explore the effects of packaging solutions with various depths on the quality of iced and superchilled farmed Atlantic salmon (Salmo salar). Insulated containers of different depths (32, 42, and 60 cm) and 17-cm deep expanded polystyrene (EPS) boxes were used to simulate transport and storage of the fish. The fish quality was evaluated after 4, 10, and 14 days of storage, where measurements on drip loss, texture, cooking yield, sensory evaluation, water and lipid distribution, and characteristics analysis in the fish muscle by nuclear magnetic resonance (NMR) spectroscopy were performed. Increased container depth from 32 to 42 cm increased the drip loss of superchilled salmon from 2.4% to 3.1% after 10 days of storage at −1°C. Iced storage of salmon for 10 days in EPS boxes resulted in less drip loss (0.5%) compared with superchilled salmon (1.5%) stored in EPS. The NMR analysis, sensory evaluation, texture analysis, and cooking yield did not reveal any major differences between salmon stored in containers of different depths. Iced storage increased pressure marks as compared with non-iced, superchilled storage in insulated containers. The results indicate that transport of whole salmon in reusable insulated plastic containers with a depth of 60 cm is possible without major quality changes observed for up to 10 days.     

Flexible space-sharing strategy for storage yard management in a transshipment hub port

In this paper, a storage yard planning problem is studied for a transshipment port with limited space and high-throughput level. Generally, the consignment strategy is used in the yard for a transshipment port, where containers to the same destination vessel are stored together. This is to facilitate faster loading process as it reduces reshuffles as well as long distance movements of yard cranes. However, the consignment strategy is known to be inefficient in space utilization since each storage location must be dedicated to a particular vessel. To improve the space utilization while retaining the advantage of consignment, a new approach named the “flexible space-sharing strategy” is proposed. The idea is that the container space can be shared by two different vessels as long as their containers do not occupy the space at the same time. This strategy allows the same storage location to be reserved for two vessels. The amount of space will only be allocated to a specific vessel on the arrival of corresponding containers. By controlling where to stack the containers in the storage locations, the containers to each vessel are not mixed and the consignment feature can be preserved. This strategy is first formulated as a mixed integer program (MIP). As the MIP model has a block diagonal structure, we develop a search algorithm which combines MIP and heuristics to find the solution. The numerical experiments show that the “flexible space-sharing strategy” can handle much more containers within the same storage space compared with the “non-sharing strategy”.     

Dispatching vehicles in a mega container terminal

We consider a container terminal discharging and uploading containers to and from ships. The discharged containers are stored at prespecified storage locations in the terminal yard. Containers are moved between the ship area and the yard using a fleet of vehicles, each of which can carry one container at a time. The problem is to dispatch vehicles to the containers so as to minimize the total time it takes to serve a ship, which is the total time it takes to discharge all containers from the ship and upload new containers onto the ship. We develop easily implementable heuristic algorithms and identify both the absolute and asymptotic worst-case performance ratios of these heuristics. In simple settings, most of these algorithms are optimal, while in more general settings, we show, through numerical experiments, that these algorithms obtain near-optimal results for the dispatching problem.Research was supported in part by the Port of Singapore Authority (PSA).     

Estimation of the atmospheric corrosion on metal containers in industrial waste disposal

Solid industrial waste are often stored in metal containers filled with concrete, and placed in well-aerated warehouses. Depending on meteorological conditions, atmospheric corrosion can induce severe material damages to the metal casing, and this damage has to be predicted to achieve safe storage. This work provides a first estimation of the corrosivity of the local atmosphere adjacent to the walls of the container through a realistic modeling of heat transfer phenomena which was developed for this purpose. Subsequent simulations of condensation/evaporation of the water vapor in the atmosphere were carried out. Atmospheric corrosion rates and material losses are easily deduced. For handling realistic data and comparison, two different meteorological contexts were chosen: (1) an oceanic and damp atmosphere and (2) a drier storage location. Some conclusions were also made for the storage configuration in order to reduce the extent of corrosion phenomena.     

Density modification of ice particles in ice slurry

One of the characteristic properties of ice slurry is the buoyancy of ice particles, which leads to ice separation in unmixed ice slurries and the necessity to agitate storage vessels if ice slurry is to be extracted. Based on this, an investigation into the density modification of ice particles has been undertaken. Additional particles with higher density than ice should act as ice forming nuclei during ice generation, for which suitable particles have been determined and tested. It was possible to show that not all added particles act as ice forming nuclei in the role of a cell nucleus. Furthermore, it can be assumed that various particles agglomerate on the surface of ice particles; hence the density of ice particles increased more than expected due to the incorporation of several particles in each ice particle. These modified ice particles may sediment to the bottom of the container due to the high density of the numerous heavy foreign particles.     

影响冻结贮运过程鱼类品质变化因素的研究进展

目的介绍影响鱼类冻结贮存品质的因素、应对品质下降的措施,以及近几年国内外的研究进展,为今后优化冻藏工艺、保持冻藏鱼类品质提供参考。方法总结国内外对影响冻藏鱼类品质因素的研究,介绍冻藏鱼类冰晶生长、蛋白质降解和脂肪氧化对鱼肉品质的影响,归纳抑制鱼肉品质下降的方法。结果在冻结贮运过程中,冰晶的形成、生长、融化、反复冻融等都会损坏鱼体细胞,引发蛋白质变性。此外,鱼体死亡后内源性蛋白酶会促进蛋白质降解,同时改变鱼肉的质构,从而影响鱼肉的品质。鱼体内富含的脂肪在贮运过程中会发生氧化反应,随着贮藏时间的延长,将会严重影响鱼肉的风味、口感。结论冻结贮运技术能有效地保持鱼类的鲜度,为了更好地保持鱼肉品质,还需要结合其他保鲜技术进行复合保鲜。     

用活性薄膜贮存活鱼

研究了无机物充填的ＰＥ薄膜－－活性薄膜（ＡＦ）贮存活鲤鱼，在封闭的状态下，与普通聚乙烯薄膜袋相比，能明显地提高鲁鱼的平均寿命，共袋中水的溶解氧２浓度及ＰＨ值均高于ＰＥ薄膜袋，说明该活性薄膜具有调节水中氧气及二氧化碳浓度的功能。     

铀部件贮存容器内气氛控制方法研究

目的研究不同气氛控制方法对铀部件贮存容器内气氛演化及铀部件腐蚀情况的影响,获得优化的气氛控制方法。方法采用虚拟表面反应的方法建立铀材料与环境气氛反应、有机材料释放水分、干燥剂吸水的计算方法,计算提高容器密封性能、干燥剂及分散放置、有机材料干燥剂处理等气氛控制措施单独使用及联合使用的7种工况下容器内湿度控制及氧含量情况,以及铀部件的腐蚀增重情况,对比分析了各种气氛控制措施的效果。结果经研究可知,对于含铀部件的贮存容器,仅提高其密封性能反而会导致容器内缺氧,从而加速铀部件的腐蚀;放置干燥剂是较好的气氛控制方式,分散放置的效果更好;采用分散放置干燥剂的同时对有机材料进行干燥处理的气氛控制措施效果最好,不仅铀部件的腐蚀速率最低,而且可以长时间保持有氧低腐蚀速率状态。结论得到了含铀部件贮存容器内多组分气氛演化规律及铀部件腐蚀情况变化的计算方法,对比研究了多种气氛控制方法在气氛控制及降低铀部件腐蚀方面的效果,获得了优化的气氛控制方法。     

我国PWR燃料组件运输容器定期评价与经验反馈

目的 介绍我国放射性物品运输容器定期安全性能评价的相关标准和要求,并着重介绍我国现有3种不同型号的压水堆新燃料组件运输容器定期安全评价工作。方法 根据GB 11806等标准规范的要求,检查容器的使用维护历史,通过一系列的现场实验和数据分析,对容器结构、包容、传热、屏蔽和防止临界等5个方面的安全性能进行系统评价。结果 通过对245台不同型号的PWR燃料组件运输容器的现场检查结果分析,容器主要存在防腐层损伤、吊耳焊缝裂纹、密封垫开裂老化等安全隐患。结论 该项工作全面系统地总结了我国压水堆新燃料组件运输容器的安全现状,特别是验证了我国使用了20余年的新燃料组件运输容器的安全性能,具有重要的现实意义。同时,对今后放射性物品运输容器的设计、使用、维护等方面进行了经验总结和反馈。     

Réfrigération des conteneurs isothermes

The isothermal container without a refrigerating unit is, intrinsically, more rustic than the autonomous container. Cooling for the former is supplied by installations which can be more sophisticated and maintenance will therefore depend upon just one technical service. This article describes various transport processes and the advantages and drawbacks of different systems employed: brine or direct expansion, rate of air circulation, refrigerating machinery and thermometry, if sensitive, will enable one to detect the inherent anomalies in the condition of the goods before loading onboard.     

A bottleneck assignment approach to the multiple container loading problem

The container loading problem addresses the question of how to store several three dimensional, rectangular items (e.g. boxes) in one or more containers in such a way that maximum use is made of the container space. The multiple container problem concentrates on the situation where the consignment to be loaded cannot be accommodated in a single container. To minimize the number of required containers the repeated application of a single container approach is often suggested in the literature. In contrast, in this paper an approach based on a set partitioning formulation of the problem is presented. Within this approach a single container algorithm is used to produce alternative loading patterns. This approach easily allows introducing additional aspects, e.g. separation of boxes or complete shipment of boxes.     

Basic considerations on the calculation of the trippage number for returnable containers

The trippage number of returnable containers has a central position in economic, calculations and in comparing the environmental impacts of disposable and returnable container systems. Extremely varying trippage numbers are frequently reported for the same type of container, usually without any reference to the method of calculation. Only a few authors have published basic considerations on the calculation of the trippage number. Different methods of calculation have been recommended and different definitions of what should be understood by the ‘trippage number’ have been given. To investigate what is really achieved by these kinds of calculation, a model system, performing all the functions of a returnable container system in practice, for system analysis by computer simulation was established. By means of this model system it was found that in the lifetime of a container population one can differentiate between three kinds of populations, each one with an individual mean trippage number:

• (i) the average trippage number of all containers put into circulation
• (ii) the average trippage number of all lost containers
• (iii) the average trippage number of all existing containers, representing the total stock of circulating containers

Emanating from these basic considerations, it was found that the actual average trippage number of all containers put into circulation after ‘x’ fillings (U_x) can be calculated exactly by the quotientof the sum of all filled containers (ΣN) and the sum of all containers put into circulation (ΣE) since the first day of use of a container type according to the following expression It must be stated that correct results can only be achieved by taking into account all containers filled or put into circulation from the very first day of use. Despite this drawback, this kind of calculation has the advantage of being based on figures that are available and easily retraceable for almost all filling-plants. After the first circulation, the average trippage number (U_x) is equal to 1.0, rising with each circulation because of its tendency to approximate to a constant final value after an infinite number of fillings (U_x→∞), which can be calculated by the quotient of the sum of all filled containers (ΣN) and the sum of all lost containers (ΣA) since the first day of use of a container type, represented by the inverse value of the proportion of lost containers (a) or its complement, the share of refillable containers (r), according to This (theoretical) final value is approximated by each partial population (the population of all input new containers, of all lost and all existing containers) but with a different velocity, dependent on the parameters a=1?r (the loss rate) and r_z =1?b (the rate of containers returning to the filling-plant from the total stock of existing containers). The number of circulations needed to approach this final value rises with a decreasing share of lost containers (a) and with a decreasing share of containers returning to the filling plant (r_z) from the total container stock. The calculation by the inverse value of the share of lost containers (l/a ) is therefore not relevant to the calculation of the actual average trippage number of any partial population (number of new containers put into circulation, lost containers or stock of all existing containers). To receive correct results, also for this calculation, it is necessary to take into account all containers filled or lost from the very first day of use. This may be troublesome with a container type used by many filling-plants and with traditional old containers, where the necessary figures are no longer available. A further drawback of this kind of calculation is that the number of lost containers cannot be calculated exactly, because of the uncertainty of whether all containers, for which the plant holds the deposit, exist or not. Therefore the share of lost containers is mostly set too low, which results in the calculation of too high a trippage number.     

A simulation study of container size in two-card kanban systems

Setting container sizes is one of the first decisions that users of kanban systems must address. Yet researchers have largely assumed container sizes to be given. This paper investigates the effect of container size on average inventory and customer service levels in a two-card kanban system processing multiple part types. Container size and the number of kanbans are varied in tandem so that total in-process inventory capacity remains constant. Simulation results show that smaller containers lead to smaller average total inventories. The surprise is that smaller containers do not always lead to poorer average customer service. Smaller container sizes can lead to better average customer service when the costs of greater total setup time are offset by the benefits of more frequent material handling, that is less frequent station material starvation, and improved finished goods part mix. This occurs primarily when container size is larger than average finished-goods order size and when setup times are relatively short.     

Simulation of a multiterminal system for container handling

A generic simulation model structure for the design and evaluation of multiterminal systems for container handling is proposed. A model is constructed by combining three basic functions: transport, transfer, and stacking. It can be used for further detailing of the subsystems in the terminal complex while preserving the container flow patterns in the system. The modeling approach has been applied to the complete set of existing and future terminals in the Rotterdam port area, using forecasts of containers flows, statistical data from existing terminals, expert opinions, and conceptual designs of the new port area called “second Maasvlakte”. Experimental results including the requirements for deep-sea quay lengths, storage capacities, and equipment for interterminal transport are shown. Further traffic flows on the terminal infrastructure are determined, and the consequences of applying security scanning of containers are evaluated.     

不同包装容器对劲酒品质的影响

目的 研究包装容器对酒体品质的影响因素,为劲酒包装容器的选择提供科学的数据支撑。方法 采用光学透过率测试仪对不同包装容器的透光率进行了测定,并对贮存2年的劲酒的总黄酮含量、总皂苷含量、色率、淫羊藿苷含量、口感进行分析,数据分析的方法为随机区组设计资料的方差分析。结果 无色玻璃瓶、PET瓶透光率高达90%以上,深色瓶、涂漆瓶、陶瓷瓶、不锈钢瓶透光率均极小。总体来说高硼硅玻璃瓶和PET瓶储存的劲酒均有不同程度的颜色变浅,总黄酮、总皂苷含量降低,口感变差,其他容器储存的酒体之间没有明显差异,且它的总体品质要高于高硼硅玻璃瓶和PET瓶储存酒体的总体品质。结论 包装容器的透光性会对劲酒的品质产生影响,避光包装容器可能更适合劲酒的储存,避光容器的材质和形状对劲酒品质基本没有影响;对于透光性容器,容器形状可能影响劲酒品质,相较于圆柱型的包装容器,扁平型的可能更能保护劲酒品质。     

复合材料包装箱保温功能设计及验证

目的为满足包装箱保温功能技术要求,探究包装箱保温层厚度设计方案。方法基于低导热系数聚氨酯保温材料,通过傅里叶定律及安全系数理论分析确定包装箱保温层厚度,再对实物包装箱按照GJB 150.4.A—2009《军用装备实验室环境试验方法》进行高低温试验并验证。结果在高低温试验中,当箱内温度为22.2℃,箱外温度为40℃时,4 h后箱内最高温度可达29.2℃;当箱内温度为25.5℃,箱外温度为?30℃时,4 h后箱内最低温度降至2℃。通过分析,得出箱体内部温度与时间以及箱体温差之间的关系,箱体外部升温1℃时,箱体内部升温速率为0.037~0.1℃/h;箱体外部降温1℃时,降温速率为0.07~0.094℃/h。结论该设计方案能满足包装箱保温功能技术要求。     

Comparison of vehicle types at an automated container terminal

At automated container terminals, containers are transshipped from one mode of transportation to another. Automated vehicles transport containers from the stack to the ship and vice versa. Two different types of automated vehicles are studied in this paper, namely automated lifting vehicles and automated guided vehicles. An automated lifting vehicle is capable of lifting a container from the ground by itself. An automated guided vehicles needs a crane to receive and deliver a container.In designing automated container terminals one have to consider the choice for a certain type of equipment. The choice for a certain type of equipment should be made by performing a feasibility and economic analysis on various types of equipment. In this paper, we examine effects of using automated guided vehicles and automated lifting vehicles on unloading times of a ship, with simulation studies. In choosing a certain type of equipment we have considered criteria such as unloading times of a ship, occupancy degrees and the number of vehicles required. 38% more AGVs need to be used than ALVs. From this specific study, we conclude that, by observing only purchasing costs of equipment, ALVs are a cheaper option than AGVs.To obtain an accurate analysis we have performed a sensitivity analysis. It can be concluded that the design of the terminal and technical aspects of quay cranes impact the number of vehicles required and as a result the choice for a certain type of equipment. Correspondence to: Iris F. A. Vis     

储存容器对重金属检测样品的影响研究

采用电感耦合等离子体光谱法（ICP-OES）,在一定条件下、不同的储存容器中,同时测定铅、镉、铬、镍、钴、锑、锌、砷8种有害物质的检测量与初始量的变化率。试验结果表明,不同材质的容器中,相同种类重金属的检测值和初始值的变化率不同;相同材质的容器中,不同种类重金属的检测值与初始值的变化率也不相同。综合分析,较适宜储存重金属溶液的容器材质为氟化乙烯丙烯共聚物。