Mechanical Engineering Commons^™

Integrating Qplm And Biomedical Test Data With An Anisotropic Fiber Distribution Model And Predictions Of Tgf-Β1 And Igf-1 Regulation Of Articular Cartilage Fiber Modulus, Michael E. Stender, Christopher B. Raub, Kevin A. Yamauchi, Reza Shirazi, Pasquale Vena, Robert L. Sah, Scott J. Hazelwood, Stephen M. Klisch

Mechanical Engineering

A continuum mixture model with distinct collagen (COL) and glycosaminoglycan elastic constituents was developed for the solid matrix of immature bovine articular cartilage. A continuous COL fiber volume fraction distribution function and a true COL fiber elastic modulus ( Ef) were used. Quantitative polarized light microscopy (qPLM) methods were developed to account for the relatively high cell density of immature articular cartilage and used with a novel algorithm that constructs a 3D distribution function from 2D qPLM data. For specimens untreated and cultured in vitro, most model parameters were specified from qPLM analysis and biochemical assay results; consequently, Ef was …

Work In Progress: Outreach Assessment: Measuring Engagement, Lizabeth Schlemer, John Oliver, Katherine Chen, Sophia Rodriguez Mata, Eric Kim

Industrial and Manufacturing Engineering

The Learn By Doing Lab (LBDL) at Cal Poly, San Luis Obispo is an on-campus laboratory where 5th through 8th grade students are taught by undergraduates who may be planning a careers in teaching. The two populations - elementary students and undergraduates - are equally important in the process. Since 2008, the lab has seen over 4000 elementary and junior high students and over 100 undergrads have participated. In most outreach assessment the number of individuals participating is an important metric, but this last Spring we experimented with a more in depth measure of effectiveness. As in any learning experience …

Technology Portal For Energy Efficient Buildings, Larry D. Hermanson, Daniel Studer, Annie Mroz

STAR Program Research Presentations

Project: Technology Portal for Energy Efficient Buildings

Date: August 2, 2012

Author: Larry Hermanson

Mentor: Daniel Studer

Cohort: Annie Mroz

Lab site: National Renewable Energy Laboratory (NREL)

Buildings account for 71% of the electricity demand and 39% of the primary energy consumption in the United States. The Commercial Buildings Group at NREL provides builders, designers and building owners accurate information to significantly improve the energy efficiency of new and existing buildings. The Technology Portal for Energy Efficient Buildings will increase the accessibility of standardized and credible energy performance data for all building systems, thereby allowing building owners to better evaluate …

Selective Laser Sintering; A Design Of Experiments, Philip David Hopkins, Victor Castillo Phd

STAR Program Research Presentations

Additive Manufacturing (AM), also commonly known as 3D Printing or Rapid Prototyping, is a method of manufacturing that provides for the ability to make intricate internal features and easily customizable parts. The concept is to break a Computer Aided Design (CAD) file into a series of thin layers that are sent to the machine and laid down one layer at a time. Just like any other form of processing, material properties can alter by undergoing this process. Manipulating various parameters of the AM process can allow for different properties to be achieved. For this reason, an in depth study will …

Integrating Courses Through Project Based Learning, Lizabeth Schlemer, Sema E. Alptekin, Karen R. Bangs

Industrial and Manufacturing Engineering

Integrating three courses (one sophomore level, two senior level) through Project Based Learning (PBL) within the Industrial Engineering curriculum at the California Polytechnic State University, San Luis Obispo is presented. Three courses (IME 443 Facilities Planning and Design - senior level; IME 420 Simulation - senior level; and IME 223 Process Improvement Fundamentals - sophomore level) were linked by various mechanisms: Common industry projects, common students in two of the three courses; senior students having access to sophomores in their teams to carry out time consuming tasks such as time studies, and sophomores having access to seniors as team members, …

Effect Of Gold Content On The Microstructural Evolution Of Sac305 Solder Joints Under Isothermal Aging, Mike Powers, Jianbiao Pan, Julie Silk, Patrick Hyland

Industrial and Manufacturing Engineering

Au over Ni on Cu is a widely used printed circuit board (PCB) surface finish, under bump metallization (UBM), and component lead metallization. It is generally accepted that less than 3 wt.% Au in Sn-Pb solder joints inhibits formation of detrimental intermetallic compounds (IMC). However, the critical limit for Au content in Pb-free solder joints is not well established. Three surface-mount package platforms, one with a matte Sn surface finish and the others with Ni/Au finish, were soldered to Ni/Au-finished PCB using Sn-3.0Ag- 0.5Cu (SAC305) solder, in a realistic manufacturing setting. The assembled boards were divided into three groups: one …

The Morphology Evolution And Voiding Of Solder Joints On Qfn Central Pads With A Ni/Au Finish, Julie Silk, Jianbiao Pan, Mike Powers

Industrial and Manufacturing Engineering

In this paper, we report on a comprehensive study regarding the morphology evolution and voiding of SnAgCu solder joints on the central pad of two different packages – QFN and an Agilent package called TOPS – on PCBs with a Ni/Au surface finish. Samples were isothermally aged at the equivalent of 0, 2, 7 and 14 years service life. Representative solder joints were cross-sectioned and analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) in order to investigate the evolution of the solder joint morphology as a function of Au content and isothermal aging. IMC thickness was …