Search results

1 – 10 of 71
Open Access
Article
Publication date: 30 June 2007

Jung Ung Min and Minyoung Park

Recently, the United Statesgovernment plans to introduce electronic container seals on all imported containers as a mandatory requirement. Further, containers without electronic…

Abstract

Recently, the United Statesgovernment plans to introduce electronic container seals on all imported containers as a mandatory requirement. Further, containers without electronic seals may be prohibited or restricted for import based on this planned regulation. An electronic seal is a tamper-free seal with radio frequency identification (RFID) chips embedded in it. It could provide additional security information such as the tamper evidence and the history of tampering status. In this paper, a brief review of the types of container seals, the characteristics of electronic seals, and their system components are presented. International efforts for securing cargo security are also reviewed including Container Security Initiative (CSI), Customs Trade Partnership Against Terrorism (C-TPAT), and International Standards Organization (ISO) requirements. Finally, the current issues and the status of technology development are discussed with future directions as a final word

Details

Journal of International Logistics and Trade, vol. 5 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

Open Access
Article
Publication date: 12 March 2020

Marius Siegfarth, Tim Philipp Pusch, Antoine Pfeil, Pierre Renaud and Jan Stallkamp

This study aims to investigate the potential of using polymer multi-material additive manufacturing (MMAM) to produce miniature hydraulic piston actuators combining rigid…

1972

Abstract

Purpose

This study aims to investigate the potential of using polymer multi-material additive manufacturing (MMAM) to produce miniature hydraulic piston actuators combining rigid structures and flexible seals. Such actuators offer great potential for medical robots in X-ray and magnetic resonance environments, where conventional piston actuators cannot be used because of safety issues caused by metal components.

Design/methodology/approach

Hydraulic pistons with two different integrated flexible seal shapes are designed and manufactured using MMAM. Design 1 features a ring-shaped seal made from a flexible material that is printed on the surface of the rigid piston shaft. Design 2 appears identical from the outside, yet an axial opening in the piston shaft is added to enable self-reinforced sealing as fluid pressure increases. For both designs, samples with three different outer diameters are fabricated leading to a total of six different piston versions. The pistons are then evaluated regarding leakage, friction and durability.

Findings

Measurement results show that the friction force for Design 2 is lower than that of Design 1, making Design 2 more suitable for the intended application. None of the versions of Design 2 shows leakage for pressures up to 1.5 MPa. For Design 1, leak-tightness varies with the outer diameter, yet none of the versions is consistently leak-tight at 1.5 MPa. Furthermore, the results show that prolonged exposure to water decreases the durability of the flexible material significantly. The durability the authors observe may, however, be sufficient for short-term or single-use devices.

Originality/value

The authors investigate a novel design approach for hydraulic piston actuators based on MMAM. These actuators are of particular interest for patient-specific medical devices used in radiological interventions, where metal-free components are required to safely operate in X-ray and magnetic resonance environments. This study may serve as a basis for the development of new actuators, as it shows a feasible solution, yet pointing out critical aspects such as the influence of small geometry changes or material performance changes caused by water absorption.

Details

Rapid Prototyping Journal, vol. 26 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 25 October 2021

Junjie Lu

This study aims to study the gas film stiffness of the spiral groove dry gas seal.

Abstract

Purpose

This study aims to study the gas film stiffness of the spiral groove dry gas seal.

Design/methodology/approach

The present study represents the first attempt to calculate gas film stiffness in consideration of the slipping effect by using the new test technology for dry gas seals. First, a theoretical model of modified generalized Reynolds equation is derived with slipping effect of a micro gap for spiral groove gas seal. Second, the test technology examines micro-scale gas film vibration and stationary ring vibration to determine gas film stiffness by establishing a dynamic test system.

Findings

An optimum value of the spiral angle and groove depth for improved gas film stiffness is clearly seen: the spiral angle is 1.34 rad (76.8º) and the groove depth is 1 × 10–5 m. Moreover, it can be observed that optimal structural parameters can obtain higher gas film stiffness in the experiment. The average error between experiment and theory is less than 20%.

Originality/value

The present study represents the first attempt to calculate gas film stiffness in consideration of the slipping effect by using the new test technology for dry gas seals.

Details

Industrial Lubrication and Tribology, vol. 73 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Open Access
Article
Publication date: 13 May 2022

Gabriel Dämmer, Hartmut Bauer, Rüdiger Neumann and Zoltan Major

This study aims to investigate the suitability of a multi-step prototyping strategy for producing pneumatic rotary vane actuators (RVAs) for the development of lightweight robots…

1217

Abstract

Purpose

This study aims to investigate the suitability of a multi-step prototyping strategy for producing pneumatic rotary vane actuators (RVAs) for the development of lightweight robots and actuation systems.

Design/methodology/approach

RVAs typically have cast aluminum housings and injection-molded seals that consist of hard thermoplastic cores and soft elastomeric overmolds. Using a combination of additive manufacturing (AM), computer numerical control (CNC) machining and elastomer molding, a conventionally manufactured standard RVA was replicated. The standard housing design was modified, and polymeric replicas were obtained by selective laser sintering (SLS) or PolyJet (PJ) printing and subsequent CNC milling. Using laser-sintered molds, actuator seals were replicated by overmolding laser-sintered polyamide cores with silicone (SIL) and polyurethane (PU) elastomers. The replica RVAs were subjected to a series of leakage, friction and durability experiments.

Findings

The AM-based prototyping strategy described is suitable for producing functional and reliable RVAs for research and product development. In a representative durability experiment, the RVAs in this study endured between 40,000 and 1,000,000 load cycles. Frictional torques were around 0.5 Nm, which is 10% of the theoretical torque at 6 bar and comparable to that of the standard RVA. Models and parameters are provided for describing the velocity-dependent frictional torque. Leakage experiments at 10,000 load cycles and 6 bar differential pressure showed that PJ housings exhibit lower leakage values (6.8 L/min) than laser-sintered housings (15.2 L/min), and PU seals exhibit lower values (8.0 l/min) than SIL seals (14.0 L/min). Combining PU seals with PJ housings led to an initial leakage of 0.4 L/min, which increased to only 1.2 L/min after 10,000 load cycles. Overall, the PU material used was more difficult to process but also more abrasion- and tear-resistant than the SIL elastomer.

Research limitations/implications

More work is needed to understand individual cause–effect relationships between specific design features and system behavior.

Originality/value

To date, pneumatic RVAs have been manufactured by large-scale production technologies. The absence of suitable prototyping strategies has limited the available range to fixed sizes and has thus complicated the use of RVAs in research and product development. This paper proves that functional pneumatic RVAs can be produced by using more accessible manufacturing technologies and provides the tools for prototyping of application-specific RVAs.

Details

Rapid Prototyping Journal, vol. 28 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 9 December 2019

Jihai Jiang, Wei-Peng Yan and Ge-Qiang Li

The purpose of this paper is to analyze the micro-motion of the cylinder block.

Abstract

Purpose

The purpose of this paper is to analyze the micro-motion of the cylinder block.

Design/methodology/approach

Based on the elasto-hydrodynamic lubrication, a numerical model for the cylinder block/valve plate interface is proposed, with consideration of the elastic deformations, the pressure-viscosity effect and asperity contacts. The influence-function method is applied to calculating the actual deformations of the cylinder block and the valve plate. The asperity contact model simplified from Greenwood assumption is introduced into the numerical model. Furthermore, the relationship between the micro-motion and the operating condition, the sealing belt width is discussed, respectively.

Findings

The results show an increase in the discharge pressure causes the tilt state and the vibrating motion getting worse, which can be eased by improving the rotational speed, the sealing belt width and the ratio of external and internal sealing belt width.

Originality/value

The proposed research can provide a theoretical reference for the optimizing design of cylinder block/valve plate pair.

Details

Industrial Lubrication and Tribology, vol. 72 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Open Access
Article
Publication date: 27 June 2023

Farid Salari, Paolo Bosetti and Vincenzo M. Sglavo

Particles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design…

Abstract

Purpose

Particles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design file is sliced to generate G-codes before printing. This paper aims to study the effect of key input parameters for slicer software on the final properties of printed products.

Design/methodology/approach

The one factor at a time (OFAT) methodology is used to investigate the impact of selected parameters on the final properties of printed specimens, and the causes for the variations in outcomes of each variable are discussed.

Findings

Finer aggregates can generate a more compact layer, resulting in a denser product with higher strength. Fluid pressure is directly determined by voxel rate (rV); however, high pressures enable better fluid penetration control for fortified products; for extreme rVs, residual voids in the interfaces between successive layers and single-line primitives impair mechanical strength. It was understood that printhead movement along the orientation of the parts in the powder bed improved the mechanical properties.

Originality/value

The design of experiment (DOE) method assesses the influence of process parameters on various input printing variables at the same time. As the resources are limited, a fractional factorial plan is carried out on a subset of a full factorial design; hence, providing physical interpretation behind changes in each factor is difficult. OFAT aids in analyzing the effect of a change in one factor on output while all other parameters are kept constant. The results assist engineers in properly considering the influence of variable variations for future DOE designs.

Details

Rapid Prototyping Journal, vol. 29 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 16 June 2022

Qinghong Fu

This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure (FSACWSS) for the high-speed railway subgrade through…

Abstract

Purpose

This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure (FSACWSS) for the high-speed railway subgrade through on-site tracking, monitoring and post-construction investigation.

Design/methodology/approach

Based on the working state of the waterproof sealing structure, the main functional characteristics were analyzed, and a kind of roller-compacted high elastic modulus asphalt concrete (HEMAC) was designed and evaluated by several groups of laboratory tests. It is applied to an engineering test section, and the long-term performance monitoring and subgrade dynamic performance testing system were installed to track and monitor working performances of the test section and the adjacent contrast section with fiber-reinforced concrete.

Findings

Results show that both the dynamic performance of the track structure and the subgrade in the test section meet the requirements of the specification limits. The water content in the subgrade of the test section is maintained at 8–18%, which is less affected by the weather. However, the water content in the subgrade bed of the contrast section is 10–35%, which fluctuates significantly with the weather. The heat absorption effect of asphalt concrete in the test section makes the temperature of the subgrade at the shoulder larger than that in the contrastive section. The monitoring value of the subgrade vertical deformation in the test section is slightly larger than that in the contrastive section, but all of them meet the limit requirements. The asphalt concrete in the test section is in good contact with the base, and there are no diseases such as looseness or spalling. Only a number of cracks are found at the joints of the base plates. However, there are more longitudinal and lateral cracks in the contrastive section, which seriously affects the waterproof and sealing effects. Besides, the asphalt concrete is easier to repair, featuring good maintainability.

Originality/value

This research can provide a basis for popularization and application of the asphalt concrete waterproof sealing structure in high-speed railways.

Details

Railway Sciences, vol. 1 no. 2
Type: Research Article
ISSN: 2755-0907

Keywords

Open Access
Article
Publication date: 2 January 2023

Sara Candidori, Serena Graziosi, Paola Russo, Kasra Osouli, Francesco De Gaetano, Alberto Antonio Zanini and Maria Laura Costantino

The purpose of this study is to describe the design and validation of a three-dimensional (3D)-printed phantom of a uterus to support the development of uterine balloon tamponade…

2132

Abstract

Purpose

The purpose of this study is to describe the design and validation of a three-dimensional (3D)-printed phantom of a uterus to support the development of uterine balloon tamponade devices conceived to stop post-partum haemorrhages (PPHs).

Design/methodology/approach

The phantom 3D model is generated by analysing the main requirements for validating uterine balloon tamponade devices. A modular approach is implemented to guarantee that the phantom allows testing these devices under multiple working conditions. Once finalised the design, the phantom effectiveness is validated experimentally.

Findings

The modular phantom allows performing the required measurements for testing the performance of devices designed to stop PPH.

Social implications

PPH is the leading obstetric cause of maternal death worldwide, mainly in low- and middle-income countries. The proposed phantom could speed up and optimise the design and validation of devices for PPH treatment, reducing the maternal mortality ratio.

Originality/value

To the best of the authors’ knowledge, the 3D-printed phantom represents the first example of a modular, flexible and transparent uterus model. It can be used to validate and perform usability tests of medical devices.

Details

Rapid Prototyping Journal, vol. 29 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 16 August 2023

Florian Ausserer, Igor Velkavrh, Fevzi Kafexhiu and Carsten Gachot

This study aims to focus on the development of an experimental setup for testing tribological pairings under a gas atmosphere at pressures up to 10 bar.

Abstract

Purpose

This study aims to focus on the development of an experimental setup for testing tribological pairings under a gas atmosphere at pressures up to 10 bar.

Design/methodology/approach

A pressure chamber allowing oscillating movement through an outer shaft was constructed and mounted on an oscillating tribometer. Due to a metal spring bellows system, a methodology for the evaluation of the coefficient of friction values separately from the spring forces was developed.

Findings

The selected material concept was qualitatively and quantitatively assessed. An evaluation of the static and the dynamic coefficient of friction was performed, which was crucial for the understanding of the adhesion effects of the tested material pairing. The amount of information that is lost due to averaging the measured friction values is higher than one would expect.

Originality/value

The developed experimental setup is unique and, compared with the existing tribometers for testing under gas ambient pressures, allows testing under contact conditions that are closer to real applications, such as compressors and expanders. An in-depth observation of the adhesion and stick–slip effects of the tested material pairings is possible as well.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2023-0173/

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Open Access
Article
Publication date: 26 November 2019

Indika Fernando, Jiangang Fei, Roger Stanley, Hossein Enshaei and Alieta Eyles

Quality deterioration in bananas along the supply chain (SC) due to cosmetic damage has been a persistent challenge in Australia. The purpose of this paper is to investigate the…

7048

Abstract

Purpose

Quality deterioration in bananas along the supply chain (SC) due to cosmetic damage has been a persistent challenge in Australia. The purpose of this paper is to investigate the incidence of cosmetic defects in bananas across the post-harvest SC and determining the causes of the diminished fruit quality at the retail stores.

Design/methodology/approach

The study quantified the level of cosmetic damage in 243 cartons of Cavendish bananas across three post-harvest SCs in Australia from pack houses to retail stores and identified the risk factors for cosmetic defects.

Findings

The level of cosmetic damage progressively increased from pack house (1.3 per cent) to distribution centre (DC) (9.0 per cent) and retail (13.3 per cent) and was significantly influenced by package height and pallet positioning during transit. Abrasion damage in ripened bananas was influenced by the travel distance between DC and retail store. The study also revealed a range of risk factors contributing to the observed damage including weakened paperboard cartons due to high moisture absorption during the ripening process.

Research limitations/implications

This study only investigated damage incidence in three post-harvest banana SCs in Australia and the damage assessments were confined to packaged bananas.

Originality/value

This study assessed the quality of bananas along the entire post-harvest SC from farm gate to retail store. The study provided knowledge of the extent of the quality defects, when and where the damage occurred and demonstrated the underlying factors for damage along the SC. This will enable the development of practical interventions to improve the quality and minimize wastage of bananas in the retail markets.

Details

Modern Supply Chain Research and Applications, vol. 1 no. 2
Type: Research Article
ISSN: 2631-3871

Keywords

1 – 10 of 71