Pre and post-treatments to improve weldability and mechanical properties of Aluminum-Polyamide laser welded specimens

in Procedia CIRP (2020), 94

The laser polishing surface treatment is a prerequisite for enhanced weldability that is enabled by superior adhesion between the weldments. The paper describes the laser polishing process of the aluminum ... [more ▼]

The laser polishing surface treatment is a prerequisite for enhanced weldability that is enabled by superior adhesion between the weldments. The paper describes the laser polishing process of the aluminum surface to develop a relatively thick and porous artificial aluminum oxide layer. Microscopic observation shows the laser polishing process significantly improves the adhesion of molten polyamide to the aluminum surface. Besides, the shear load of the pretreated joints is much higher than that of as-received ones. However, for the majority of the welded samples, the failure happens at the polyamide near the interface of aluminum/polyamide due to the thermal effect and structural changes of polyamide during the welding process. By applying the post-treatment of the welded specimens with different cycles, the mentioned failure mechanism is not observed anymore. Therefore, the mechanical properties of the joint will be improved and reach to the limits of the base materials. [less ▲]

Pre-Conference Workshop #3 : Experimental Media Archaeology

Presentation (2017, June 28)

Pre-empted Patents, Infringed Patents, and Firms’ Participation in Markets for Technology

in Research Policy (2014)

Pre-Hurricane Consumer Stockpiling and Post- Hurricane Product Availability: Empirical Evidence from Natural Experiments

in Production and Operations Management (2020), 29(10), 2350-2380

The provision of essential supplies is a key service provided by retailers when demand spikes due to consumer stockpiling during environmental emergencies. Moreover, it is important for retailers to ... [more ▼]

The provision of essential supplies is a key service provided by retailers when demand spikes due to consumer stockpiling during environmental emergencies. Moreover, it is important for retailers to quickly recover from these events by replenishing the stock of essential supplies to meet the continuing needs of local residents. The main purpose of this research is to study consumer precautionary stockpiling behavior prior to the onset of hurricane landfalls and determine the impact of this behavior on in-store product availability for various formats of retail store outlets. Specifically, we focus on the bottled water product category, an essential emergency category in hurricane preparedness. This study combines an event analysis methodology with econometric models using archival retail scanner data from 60 U.S. retail chains located in 963 counties and real-time data from four recent U.S. continental hurricanes. We find that supply-side characteristics (retail network and product variety), demand-side characteristics (hurricane experience and household income), and disaster characteristics (hazard proximity and hazard intensity) significantly affect consumer stockpiling propensity as the hurricanes approach. The increased consumer stockpiling has immediate and longer-term impacts on retail operations, namely, in-store product availability. Among various retail formats, drug stores are associated with the highest consumer stockpiling propensity before hurricanes, while dollar stores and discount stores are associated with the lowest in-store product availability following hurricanes. Our study points to the need for retailers and policymakers to carefully monitor factors affecting consumer stockpiling behavior that will allow for better allocation of critical supplies during the hurricane season. [less ▲]

A pre-literary intervention in a multilingual setting.

Poster (2015, September)

Pre-primary Education in Mauritius: Perspectives on Play for Development in Diversified Contexts

Report (2009)

Pre-service teachers and classroom teachers learning together: A collaborative teacher education program

in Excelsior: Leadership in Teaching and Learning (2007), 1(2), 39-48

The field-based science methods course described in this paper uses a professional development school to enhance the professional practices of classroom teachers, pre-service teachers, and college faculty ... [more ▼]

The field-based science methods course described in this paper uses a professional development school to enhance the professional practices of classroom teachers, pre-service teachers, and college faculty alike. Participants work together to develop and teach inquiry-based science in a fourth-grade classroom. This article describes how participants are immersed in the teaching and learning of science. [less ▲]

Pre-service teachers' beliefs about mathematics teaching and learning in preschool

Scientific Conference (2015)

Pre-shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism

in Proc. WCX World Congress Experience (2018, April)

The automotive industry is swiftly moving towards Ethernet as the high-speed communication network for in-vehicle communication. There is nonetheless a need for protocols that go beyond what standard ... [more ▼]

The automotive industry is swiftly moving towards Ethernet as the high-speed communication network for in-vehicle communication. There is nonetheless a need for protocols that go beyond what standard Ethernet has to offer in order to provide additional QoS to demanding applications such as ADAS systems or audio/video streaming. The main protocols currently considered for that purpose are IEEE802.1Q, AVB with the Credit Based Shaper mechanism (IEEE802.1Qav) and TSN with its Time-Aware Shaper (IEEE802.1Qbv). AVB/CBS and TSN/TAS both provide efficient QoS mechanisms and they can be used in a combined manner, which offers many possibilities to the designer. Their use however requires dedicated hardware and software components, and clock synchronization in the case of TAS. Previous studies have also shown that the efficiency of these protocols depends much on the application at hand and the value of the configuration parameters. In this work, we explore the use of “pre-shaping” strategies under IEEE802.1Q for bursty traffic such as audio/video streams as a simple and efficient alternative to AVB/CBS and TSN/TAS. Pre-shaping means inserting on the sender side “well-chosen” pauses between successive frames of a transmission burst (e.g., as it happens when sending a camera frame), all the other characteristics of the traffic remaining unchanged. We show on an automotive case-study how the use of pre-shaping for audio/video streams leads to a drastic reduction of the communication latencies for the best-effort streams while enabling to meet the timing constraints for the rest of the traffic. We then discuss the limitations of the pre-shaping mechanism and future works needed to facilitate its adoption. [less ▲]

Preassociative aggregation functions

in Laurent, Anne; Strauss, Olivier; Bouchon-Meunier, Bernadette (Eds.) et al 15th International Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems, IPMU 2014, Montpellier, France, July 15-19, 2014. Proceedings, Part III (2014, July 22)

We investigate the associativity property for varying-arity aggregation functions and introduce the more general property of preassociativity, a natural extension of associativity. We discuss this new ... [more ▼]

We investigate the associativity property for varying-arity aggregation functions and introduce the more general property of preassociativity, a natural extension of associativity. We discuss this new property and describe certain classes of preassociative functions. [less ▲]