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This paper seeks to present the results of an experiment to investigate the effect of six part orientation (XY, XZ, YX, YZ, ZY, ZX) and a wide range of energy densities on ultimate tensile strength (UTS) and elongation of laser‐sintered nylon 12 (PA‐12) test specimens.

ASTM Type 1 specimens were built on a DTM Sinterstation 2500+ and tensile tested on an Instron 5569 A. The resulting data were fit to non‐linear regression models based on the well‐known Weibull growth model to predict each response based on the total energy density used in each trial.

The resulting regression models provide excellent fits with low sum of squared errors and normally distributed residuals. The resulting material properties are highly affected by the energy density and the build orientation. However, once sufficient energy density is applied, properties tend to converge to consistent values. To achieve maximum UTS of approximately 52 MPa, it is recommended that values of energy density above 0.25 W‐s per mm³ be used. To achieve maximum elongation of approximately 15‐16 percent, it is recommended that values of energy density above 0.40 W‐s per mm³ be used when building parts in the XY, XZ, YX, YZ orientations. Parts built in the ZX orientation exhibit lower elongation values at or below 12 percent for even high values of energy density.

This paper extends previous work of Starr, Gornet and Usher on the relationship between material properties, part orientation and energy density by proposing the use of the Weibull growth model. Recommendations are provided to assist users in the selection of correct energy density to achieve desirable mechanical properties in each specified orientation.

Adhesion has been measured between a powder injection molded (PIM) part and the stereolithography epoxy mold surrounding it after cooling. Analysis of release behavior suggests a link to the thermal properties of the mold material. Subsequent measurements of cooling in the part and at the part/mold interface are consistent with a one‐dimensional heat transfer model. Adhesion development at the part/mold interface shows a complex dependence on the thermal characteristics of both the mold and the PIM feedstock.

The purpose of this paper is to measure the effect of process conditions on mechanical properties of laser‐sintered nylon 12 (Duraform^®) and to determine the range of conditions that provide consistent mechanical performance for additive manufacturing.

Tensile test specimens were fabricated over a range of well‐characterized process conditions including laser power, laser speed, scan spacing, layer thickness, build orientation, and build position. Tensile modulus, yield strength, ultimate tensile strength and elongation‐at‐fracture were measured and related to process parameters.

Tensile properties are strongly related to the amount of energy deposited during scanning. Strength and modulus approach their maximum values as the energy deposited exceeds the amount needed to fully melt the applied powder. Elongation‐at‐fracture does not reach its maximum until higher energy‐melt ratio. Performance of blends with reused powder matches that of virgin powder when blend composition is adjusted to a standard melt‐flow index. The volumetric energy density and the energy‐melt ratio are useful for correlating mechanical properties with multiple process parameters and material thermal properties.

This work presents the most extensive data to date on mechanical properties of nylon 12 (Duraform^®) as they relate to the full range of process parameters. These data show that mechanical performance correlates strongly with the volume energy density. In contrast to the area energy density (a.k.a. Andrews Number), this volumetric parameter includes the effect of varying layer thickness and can be related directly to the melting characteristics of the polymer material. Within the parameter range studied, this relationship allows adjustment of one scan parameter for improved speed or dimensional accuracy while ensuring good strength by an offsetting adjustment of another parameter. Such trade‐offs will be important in future manufacturing applications of the laser sintering process. Understanding the energy‐melt ratio provides insight into the relationship between scan conditions and the physics of powder melting and sintering, and offers a methodology to relate results at other bed temperatures and with other polymer powders.

President Bill Clinton has had many opponents and enemies, most of whom come from the political right wing. Clinton supporters contend that these opponents, throughout the Clinton presidency, systematically have sought to undermine this president with the goal of bringing down his presidency and running him out of office; and that they have sought non‐electoral means to remove him from office, including Travelgate, the death of Deputy White House Counsel Vincent Foster, the Filegate controversy, and the Monica Lewinsky matter. This bibliography identifies these and other means by presenting citations about these individuals and organizations that have opposed Clinton. The bibliography is divided into five sections: General; “The conspiracy stream of conspiracy commerce”, a White House‐produced “report” presenting its view of a right‐wing conspiracy against the Clinton presidency; Funding; Conservative organizations; and Publishing/media. Many of the annotations note the links among these key players.

In an era when engagement in public spaces and places is increasingly regulated and constrained, we argue for the use of literary analytic tools to enable younger generations to critically examine and reenvision everyday spatialities (Rogers, 2016; Rogers et al., 2015). The purpose of this paper is to consider how spatial analyses of contemporary young adult literature enrich interrogations of the spaces and places youth must navigate, and the consequences of participation for different bodies across those spheres.

In a graduate seminar of teachers and writers, we examined literary texts through a combined framework of feminist cultural geography, mobilities and critical mobilities studies. In this paper, we interweave our own spatial analyses of two selected works of young adult fiction with the reflections of our graduate student participants to explore our spatial framework and its potential to enhance critical approaches to literature instruction.

We argue that spatial literary analysis may equip teachers and students with tools to critically examine the spaces and places of everyday life and creatively reenvision what it means to be an engaged citizen in uncertain and troubling times.

While we have engaged in this work for several years, we found that in light of the global pandemic, coupled with the recent antiracist demonstrations, a spatial approach to literary study emerges as a potentially even more relevant and powerful component of literature instruction.

The purpose of this paper is to provide a retrospective review of an early marketing text, Marketing Methods (1918) by Ralph Starr Butler.

Marketing Methods is summarized, and perspectives of scholars that have occurred since its publication are provided.

Marketing Methods represents the first college textbook to use the term “marketing” and, thus, represents a major and important early work in the field.

This review of Marketing Methods provides a retrospective on the development, structure, critical reviews and influence of this text.

Characteristics of the metal powder are a key factor in the success of powder bed fusion (PBF) additive manufacturing. Powders for PBF from different manufacturers may have a different particle size and/or bulk packing and flow behavior. Powder properties change as the powder is reused for multiple builds. This study seeks to measure the variability of commercial 17-4 PH stainless steel powders to determine the effect of powder variability on part density and demonstrate characterization methods that ensure part quality.

Commercial atomized metal powders from four different vendors were produced with two different atomizing gases (N2 and argon). Powder was characterized in both new and extensively reused conditions. All powders were characterized for flow and packing behavior, particle size and internal porosity. Coupons were manufactured using the laser PBF process with optimized scan strategy and exposure parameters. The quality of fabricated parts was measured using bulk density measurement.

Despite differences in powder flowability and particle size, fully dense parts (>99 per cent) were produced using all powders, except one. Residual porosity in these parts appeared to result from gas trapped in the powder particles. The powder with extensive reuse (400+ h in machine fabrication environment) exhibited reduced flowability and increased fraction of fine particles, but still produced full density parts.

This study demonstrates that full density parts can be fabricated using powders with a range of flowability and packing behavior. This suggests that a single flowability measurement may be sufficient for quality assurance in a production environment.

From one angle, abortion law appears to confirm the regime politics account of the Supreme Court; after all, the Reagan/Bush coalition succeeded in significantly curtailing the constitutional protection of abortion rights. From another angle, however, it is puzzling that the Reagan/Bush Court repeatedly refused to overturn Roe v. Wade. We argue that time and again electoral considerations led Republican elites to back away from a forceful assertion of their agenda for constitutional change. As a result, the justices generally acted within the range of possibilities acceptable to the governing regime but still typically had multiple doctrinal options from which to choose.