Technical Library | 2024-08-29 18:30:46.0
The mechanical experience of consumption (i.e., feel, softness, and texture) of many foods is intrinsic to their enjoyable consumption, one example being the habit of twisting a sandwich cookie to reveal the cream. Scientifically, sandwich cookies present a paradigmatic model of parallel plate rheometry in which a fluid sample, the cream, is held between two parallel plates, the wafers. When the wafers are counterrotated, the cream deforms, flows, and ultimately fractures, leading to separation of the cookie into two pieces. We introduce Oreology (/Oriːˈɒl@dʒi/), from the Nabisco Oreo for "cookie" and the Greek rheo logia for "flow study," as the study of the flow and fracture of sandwich cookies. Using a laboratory rheometer, we measure failure mechanics of the eponymous Oreo's "creme" and probe the influence of rotation rate, amount of creme, and flavor on the stress–strain curve and postmortem creme distribution. The results typically show adhesive failure, in which nearly all (95%) creme remains on one wafer after failure, and we ascribe this to the production process, as we confirm that the creme-heavy side is uniformly oriented within most of the boxes of Oreos. However, cookies in boxes stored under potentially adverse conditions (higher temperature and humidity) show cohesive failure resulting in the creme dividing between wafer halves after failure. Failure mechanics further classify the creme texture as "mushy." Finally, we introduce and validate the design of an open-source, three-dimensionally printed Oreometer powered by rubber bands and coins for encouraging higher precision home studies to contribute new discoveries to this incipient field of study
Technical Library | 2011-09-26 13:53:30.0
On September 14, 2010, the late Shannon Wren, owner of VisionTech Components ("VisionTech"), and Stephanie McCloskey, VisionTech's Administrative Manager, were arrested during the execution of search and seizure warrants issued against the pair by the United States government after evidence connected them to the sale of counterfeit parts to the U.S. Navy, defense contractors and others. A ten-count indictment charged McCloskey with conspiracy, aiding and abetting in violation of Title 18 United States Code, Sections 371 and 2; trafficking in counterfeit goods, in violation of Title 18 United States Code, Section 2320; and mail fraud, in violation of Title 18 United States Code, Section 1341. McCloskey pled guilty to conspiracy and aiding and abetting for her role in the scheme.
Technical Library | 2008-12-23 22:32:32.0
Myth 1: I don't worry about design, because most of my problems are with defects from suppliers...
Technical Library | 2023-09-23 22:29:02.0
Moisture trapped within components and PBs presents a serious problem during the fabrication and assembly process. Too much moisture can lead to board failures when it is turned to steam during the reflow process.
Technical Library | 2016-09-15 17:10:40.0
This paper describes the purpose, methodology, and results to date of thermal endurance testing performed at the company. The intent of this thermal aging testing is to establish long term reliability data for printed wiring board (PWB) materials for use in applications that require 20+ years (100,000+ hours) of operational life under different thermal conditions. Underwriters Laboratory (UL) testing only addresses unclad laminate (resin and glass) and not a fabricated PWB that undergoes many processing steps, includes copper and plated through holes, and has a complex mechanical structure. UL testing is based on a 5000 hour expected operation life of the electronic product. Therefore, there is a need to determine the dielectric breakdown / degradation of the composite printed circuit board material and mechanical structure over time and temperature for mission critical applications.
Technical Library | 2010-06-03 22:23:03.0
Strategies for successful design and manufacture of microwave multilayer printed circuit boards. All aspects from pad registration, dimensional stability, impedance fluctuation, fusion bonding, thermal ageing, z-axis expansion, reliability, to Young's mod
Technical Library | 2011-02-10 16:14:34.0
In this paper, we discuss an electromagnetics based approach to transmission line design, and then explore a novel printed transmission line, Periodic Micro Transmission Line (PMTL™, Patents Pending), with improved signal integrity to 40 GHz.
Technical Library | 2012-08-09 20:33:45.0
First published in the 2012 IPC APEX EXPO technical conference proceedings. Corrosion resistance is becoming one of the most important topics in the electronics industry. Corrosion results in field failures and huge losses, which annually total several bi
Technical Library | 1999-05-06 14:46:09.0
Semiconductor manufacturing is characterized by very complex process flows made up of individual process steps, many of which are built to very close tolerances. Furthermore, there are complex interactions in these process flows, whereby each process step can affect many other steps, and each final device parameter might be determined by the results from many inputs...
Technical Library | 2009-02-26 03:25:09.0
STI has developed a patented1 packaging technology coined Imbedded Component/Die Technology (IC/DT®) to integrate multiple subsystems within an electronics assembly into a single, advanced, high-density assembly. Imbedded Component/Die Technology (IC/DT®) enables the manufacturing and assembly of smaller, lighter, and more technologically advanced high density CCAs through imbedding unpackaged components in a 3-D laminate substrate with integrated thermal management
