3D Printers, Obsolete Firearm Supply Controls, and the Right To Build Self-Defense Weapons Under Heller

This Comment describes how 3D printers will render current firearm regulations obsolete by allowing individuals to easily produce firearms—production that, when exercised by law-abiding citizens, may be protected under the Supreme Court’s decision in District of Columbia v. Heller. The regulatory system will be undermined in two phases. First, printers will be able to produce the only regulated piece of a firearm, the frame. Second, the printing of complete guns may be realized as 3D print technology advances or firearm design evolves. These developments, which could cause substantial changes in how both criminals and legitimate consumers obtain firearms, could lead to outright prohibition of personal manufacture or specific bans on weapons made by 3D printers. District of Columbia v. Heller, the Supreme Court’s 2008 decision interpreting the Second Amendment as protecting an individual right to possess firearms, could be interpreted to constrain this particular regulatory response. Specifically, Heller may create a right for individuals to make their own weapons to be used in self-defense and may protect certain processes and materials involved in making firearms. Part I introduces 3D printers and explains which gun components they can already produce. Part II explains how firearms are presumptively distributed under federal regulations, describes the structure of the firearm industry, and discusses theories on how consumers and criminals actually obtain guns. Part III explains how 3D printers may change the way firearms are acquired, undermining or even rendering obsolete the current regulatory system. Part IV, after outlining the constitutional right to bear arms, interprets Heller as supporting an individual right for law-abiding citizens to make their own self-defense weapons, and explains why this interest is legitimate. Part IV also analyzes the extent to which Heller may extend Second Amendment protection to weapons made by additive manufacturing. The Conclusion summarizes and stresses the importance of 3D printers remaining unrestricted, irrespective of their influence on self-defense. Cite as: 42 Golden Gate U. L. Rev. 447 (2012)

3D Printers, Obsolete Firearm Supply Controls, and the Right To Build Self-Defense Weapons Under Heller

This Comment describes how 3D printers will render current firearm regulations obsolete by allowing individuals to easily produce firearms—production that, when exercised by law-abiding citizens, may be protected under the Supreme Court’s decision in District of Columbia v. Heller. The regulatory system will be undermined in two phases. First, printers will be able to produce the only regulated piece of a firearm, the frame. Second, the printing of complete guns may be realized as 3D print technology advances or firearm design evolves. These developments, which could cause substantial changes in how both criminals and legitimate consumers obtain firearms, could lead to outright prohibition of personal manufacture or specific bans on weapons made by 3D printers. District of Columbia v. Heller, the Supreme Court’s 2008 decision interpreting the Second Amendment as protecting an individual right to possess firearms, could be interpreted to constrain this particular regulatory response. Specifically, Heller may create a right for individuals to make their own weapons to be used in self-defense and may protect certain processes and materials involved in making firearms. Part I introduces 3D printers and explains which gun components they can already produce. Part II explains how firearms are presumptively distributed under federal regulations, describes the structure of the firearm industry, and discusses theories on how consumers and criminals actually obtain guns. Part III explains how 3D printers may change the way firearms are acquired, undermining or even rendering obsolete the current regulatory system. Part IV, after outlining the constitutional right to bear arms, interprets Heller as supporting an individual right for law-abiding citizens to make their own self-defense weapons, and explains why this interest is legitimate. Part IV also analyzes the extent to which Heller may extend Second Amendment protection to weapons made by additive manufacturing. The Conclusion summarizes and stresses the importance of 3D printers remaining unrestricted, irrespective of their influence on self-defense. Cite as: 42 Golden Gate U. L. Rev. 447 (2012)

Isovector nuclear spin-orbit interaction from chiral pion-nucleon dynamics

Using the two-loop approximation of chiral perturbation theory, we calculate the momentum and density dependent isovector nuclear spin-orbit strength $V_{ls}(p,k_f)$. This quantity is derived from the spin-dependent part of the interaction energy $\Sigma_{spin} = {i\over 2} \vec \sigma \cdot (\vec q \times\vec p)[U_{ls}(p,k_f)- V_{ls}(p,k_f)\tau_3 \delta]$ of a nucleon scattering off weakly inhomogeneous isospin-asymmetric nuclear matter. We find that iterated $1\pi$-exchange generates at saturation density, $k_{f0}=272.7$MeV, an isovector nuclear spin-orbit strength at $p=0$ of $V_{ls}(0,k_{f0}) \simeq 50$ MeVfm$^2$. This value is about 1.4 times the analogous isoscalar nuclear spin-orbit strength $U_{ls}(0,k_{f0})\simeq 35$ MeVfm$^2$ generated by the same two-pion exchange diagrams. We also calculate several relativistic 1/M-corrections to the isoscalar nuclear spin-orbit strength. In particular, we evaluate the contributions from irreducible two-pion exchange to $U_{ls}(p,k_f)$. The effects of the three-body diagrams constructed from the Weinberg-Tomozawa $\pi\pi NN$-contact vertex on the isoscalar nuclear spin-orbit strength are computed. We find that such relativistic 1/M-corrections are less than 20% of the isoscalar nuclear spin-orbit strength generated by iterated one-pion-exchange, in accordance with the expectation from chiral power counting.Comment: 15 pages, 8 figure

Murre populations in flux : what factors affect seabird reproductive success?

Overview: The reproductive success of common murres at Yaquina Head Outstanding Natural Area varies from year to year. Students will learn how researchers monitor seabird populations and explore data to determine how seabird reproductive success is connected to environmental conditions and trophic relationships.Learning Goals: Students will learn the following: • Reproductive success of organisms can vary from year to year. • Long term data collection provides opportunities to record patterns and detect anomalies. • Reproductive success can be connected to environmental conditions

Nuclear spin-orbit interaction from chiral pion-nucleon dynamics

Using the two-loop approximation of chiral perturbation theory, we calculate the momentum and density dependent nuclear spin-orbit strength $U_{ls}(p,k_f)$. This quantity is derived from the spin-dependent part of the interaction energy $\Sigma_{spin} = {i\over 2} \vec \sigma \cdot (\vec q \times\vec p) U_{ls}(p,k_f)$ of a nucleon scattering off weakly inhomogeneous isospin symmetric nuclear matter. We find that iterated $1\pi$-exchange generates at saturation density, $k_{f0}=272.7$MeV, a spin-orbit strength at $p=0$ of $U_{ls}(0,k_{f0})\simeq 35$ MeVfm$^2$ in perfect agreement with the empirical value used in the shell model. This novel spin-orbit strength is neither of relativistic nor of short range origin. The potential $V_{ls}$ underlying the empirical spin-orbit strength $\widetilde U_{ls}= V_{ls} r_{ls}^2$ becomes a rather weak one, $V_{ls}\simeq 17$ MeV, after the identification $r_{ls}= m_\pi^{-1}$ as suggested by the present calculation. We observe however a strong $p$-dependence of $U_{ls}(p,k_{f0})$ leading even to a sign change above $p=200$MeV. This and other features of the emerging spin-orbit Hamiltonian which go beyond the usual shell model parametrization leave questions about the ultimate relevance of the spin-orbit interaction generated by $2\pi$-exchange for a finite nucleus. We also calculate the complex-valued isovector single-particle potential $U_I(p,k_f)+ i W_I(p,k_f)$ in isospin asymmetric nuclear matter proportional to $\tau_3 (N-Z)/(N+Z)$. For the real part we find reasonable agreement with empirical values and the imaginary part vanishes at the Fermi-surface $p=k_f$.Comment: 20 pages, 10 Figures, Accepted for publication in Nuclear Physics

Underwater acoustic measurements of the WET-NZ device at Oregon State University’s ocean test facility

Potential impacts from sound transmitted by wave energy conversion (WEC) devices on marine ecosystems are not well understood and remain an important environmental concern for the developing marine hydrokinetic renewable energy industry. On August 22, 2012 the Northwest National Marine Renewable Energy Center (NNMREC) began a test deployment of a WEC device at Oregon State University’s ocean test facility (OTF) off the coast of Newport, Oregon (figure 1). The operational Wave Energy Technologies – New Zealand (WET-NZ) device provides the first opportunity to measure acoustic changes in the ambient sound field resulting from WEC technology testing at NNMREC’s mobile OTF. The main objective of the acoustic measurements included in this initial report is to determine if the WET-NZ device under test transmits acoustic energy above National Marine Fisheries Service (NMFS) marine mammal harassment thresholds

Technology Screens and Effects on Attention: A Meta-Analysis

This study looks at how technology screens have an effect on academic performance considering how technology is becoming relied upon more every day. A meta-analytic review that quantitively combines data was conducted to estimate effect sizes between technology screens and academic performance. The study held no restrictions on location or ethnicity. 12 studies were chosen, consisting of 31,844 total participants. Ethnicity, research design, and screen type were found to moderate the effect of screen time on academic performance. Theoretical implications and future research is also discussed in this study

The sediment response of a dissipative beach to variations in wave climate

Using wave and wind data from nearby buoys and gauges, real time kinematic global positioning system (RTK-GPS) and light detection and ranging (lidar) topographic survey data, and a robust video record, we have quantified the Large Scale Coastal Behavior (LSCB) of a dissipative end member beach in the Pacific Northwest. This study of Agate Beach from 1992 - 2001 reveals important observations of beach behavior on temporal and spatial scales that have received little attention in recent nearshore research. Similarly, the high-energy conditions characteristic of the Agate Beach study site define it as an dissipative end member that is not well understood. In order to describe the variability of the system at spatial scales of hundreds of meters to kilometers and time scales of months to years, regression models for wave parameters and the beach sediment response were developed consisting of annually periodic functions superimposed upon long-term trends. The amplitudes of the seasonal periodicity in significant wave heights (AHs = 0.94 m ± 0.06), dominant wave period (ATp = 2.1 sec ± 0.1), and mean wave direction (Aθ 12.3° ± 2.0) exhibit larger variability than the long-term trends observed within a year (βHs = 6.7 cm/yr ± 2.6, βTp = 0.15 sec/yr ± 0.04, βθ = 3° S/yr ± 1.0). Agreement between the long-term trends in wave statistics and morphology suggest a directly forced beach response. Assuming alongshore transport of sediment at Agate Beach is wave-driven, the long-term increase in significant wave heights (βHs) and change to a more southerly approach in wave direction (βθ), coincident with the 1997-98 El Niflo/ 1998-99 La Nina sequence, correlate with the increase in sediments along the beach (ΔVb = l.84x10⁵ m³). Predictions of wavedriven alongshore transport estimate a net accretion at Agate Beach (ψ net = 2.73x10⁸ m³) over the 9 year record length. In addition to the long-term increasing trend in sediment volume, a seasonally based fluctuation in sediments is observed (Avb = 7.85x10⁴ m³ ± 2.13x10⁴). Video image analysis shows this increase in subaerial beach sediment volume at the northern end of the Newport littoral cell also coincides with the long-term offshore migration of the outer sand bar (βoBx = 11.0 m/yr ± 0.8). This result also suggests accretion of sediments in a wider crossshore region than observed in the survey record. Similar to the signature of beach volume variations, the cross-shore position of the outer sand bar also varies with season (AQBX = 114.9 m ± 4.2). The seasonal migrations in the outer sand bar position displays much larger variations than the long-term behavior described by βOBx. Analysis of 27 topographic surveys resolves the cross-shore structure of the time varying beach surface. Using empirical orthogonal functions (EOF), 2 distinct eigen-modes of variance describe the seasonal patterns of sediment behavior at Agate Beach. The first mode describes 34% of the variance and is related to the summer growth of a dune field that is limited to elevations above MHW, z = 1.076 m. Analysis of concurrent wind field measurements shows this mode of variance is well correlated with aeolian processes. The second mode (21% of the variance) is wave-driven, and corresponds to the seasonal behavior of the beach surface below MHW. Observations show the MHW elevation serves as a transitional zone between dune related and wave-driven processes that affect the seasonal evolution of Agate Beach