scholarly journals Experimental study on a small scale of gas hydrate cold storage apparatus

2010 ◽  
Vol 87 (11) ◽  
pp. 3340-3346 ◽  
Author(s):  
Yingming Xie ◽  
Gang Li ◽  
Daoping Liu ◽  
Ni Liu ◽  
Yingxia Qi ◽  
...  
Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 949
Author(s):  
Maged Mohammed ◽  
Nashi Alqahtani ◽  
Hamadttu El-Shafie

Dates are subjected to postharvest losses in quality and quantity caused by water loss, fermentation, insect infestation, and microbial spoilage during storage. Cold storage is the main element in the postharvest quality management used for fruit preservation. Although cold storage is used for dates, precision control of the relative humidity (RH) using ultrasonic applications is not used thus far, or it is applied to other fruits on a small scale. Therefore, we designed and constructed an ultrasonic humidifier (DUH) for RH control in the cold storage room (CSR) of dates. The optimum air velocity of 3 m s−1 at the outlets of the DUH ducts produced a mist amount of 6.8 kg h-1 with an average droplet diameter of 4.26 ± 1.43 µm at the applied voltage of 48 V and frequency of 2600 kHz of the transducers. The experimental validation was carried out by comparing a CSR controlled with the DUH with two conventional CSRs. The three tested CSRs were similar in dimensions, cooling system, and amount of stored dates. The time required for cooling 800 kg of dates in the controlled CSR from 25 °C to the target temperature of 5 °C was approximately 48 h. The DUH precisely controlled the RH at the maximum RH set point of 80% in the tested CSR at 5 °C. The controlled RH at 80% has a positive impact on the physicochemical characteristics of the stored dates. It significantly reduced the weight loss of the fruits and preserved fruit mass, moisture content, water activity, firmness, and color parameters. However, no significant effect was observed on fruit dimensions, sphericity, and aspect ratio. The microbial loads of mesophilic aerobic bacteria, molds, and yeasts fell within the acceptable limits in all tested CSRs. Both stored date fruits and artificially infested dates showed no signs of insect activity in the controlled CSR at the temperature of 5 °C and RH of 80%. The DUH proved to be a promising technology for postharvest quality management for dates during cold storage.


2014 ◽  
Vol 6 (5) ◽  
pp. 053108 ◽  
Author(s):  
Anders Mandrup Hansen ◽  
Robert Laugesen ◽  
Henrik Bredmose ◽  
Robert Mikkelsen ◽  
Nikolaos Psichogios

Author(s):  
K M Ahtesham Hossain Raju ◽  
Shinji Sato

Response of sand dune when overwashed by tsunami or storm surge, is investigated by conducting small scale laboratory study. Dune consisting of initially wet sand and initially dry sand are tested for three different sand grain sizes. Overtopping of water and the corresponding sediment transport are analyzed. These data set can be used to validate mathematical models associated with dune sediment transport as well as prediction of dune profile.


Author(s):  
Seiji Takanashi ◽  
Hiroki Takahashi ◽  
Tomohito Hori

At demolition sites in Japan, columns and walls are pulled down and demolished by heavy machinery or wire ropes. In a small-scale building in urban areas, columns and walls are pulled down by wire ropes. Before pulling down, workers damage the bottom part of the columns and walls for weakening them. However, if the damage of the columns and walls are too much, they fall down before use of wire ropes. As a result, they may crush workers. In this study, a fall prevention material was proposed with its installation method and verified its effectiveness by experiments. In an experiment of this study, steel pipes for supporting 3m-column were examined. The steel pipes were installed diagonally to the column. The column was loaded horizontally. We measured load and deformation until the steel pipe failed. As a result of experiments, it was found that the steel pipe buckled or the bolt supporting the steel pipe damaged. We concluded that this method is effective because the steel pipes were found to be sufficiently strong against the load generated in the steel pipes when the columns fell.


2018 ◽  
pp. 256-277
Author(s):  
Elena Novak ◽  
Tristan E. Johnson

Considerable resources have been invested in examining the game design principles that best foster learning. One way to understand what constitutes a well-designed instructional game is to examine the relationship between gaming characteristics and actual learning. This report discusses the lessons learned from the design and development process of instructional simulations that are enhanced by competition and storyline gaming characteristics and developed as instructional interventions for a study on the effects of gaming characteristics on learning effectiveness and engagement. The goal of the instructional simulations was to engage college students in learning the statistics concepts of standard deviation and the empirical rule. A pilot study followed by a small-scale experimental study were conducted to improve the value and effectiveness of these designed simulations. Based on these findings, specific practical implications are offered for designing actual learning environments that are enhanced by competition and storyline gaming elements.


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