Distribution Of Relative Angles Research Articles

Combining Ergonomic Risk Assessment (RULA) with Inertial Motion Capture Technology in Dentistry-Using the Benefits from Two Worlds.

Traditional ergonomic risk assessment tools such as the Rapid Upper Limb Assessment (RULA) are often not sensitive enough to evaluate well-optimized work routines. An implementation of kinematic data captured by inertial sensors is applied to compare two work routines in dentistry. The surgical dental treatment was performed in two different conditions, which were recorded by means of inertial sensors (Xsens MVN Link). For this purpose, 15 (12 males/3 females) oral and maxillofacial surgeons took part in the study. Data were post processed with costume written MATLAB® routines, including a full implementation of RULA (slightly adjusted to dentistry). For an in-depth comparison, five newly introduced levels of complexity of the RULA analysis were applied, i.e., from lowest complexity to highest: (1) RULA score, (2) relative RULA score distribution, (3) RULA steps score, (4) relative RULA steps score occurrence, and (5) relative angle distribution. With increasing complexity, the number of variables times (the number of resolvable units per variable) increased. In our example, only significant differences between the treatment concepts were observed at levels that are more complex: the relative RULA step score occurrence and the relative angle distribution (level 4 + 5). With the presented approach, an objective and detailed ergonomic analysis is possible. The data-driven approach adds significant additional context to the RULA score evaluation. The presented method captures data, evaluates the full task cycle, and allows different levels of analysis. These points are a clear benefit to a standard, manual assessment of one main body position during a working task.

Invariant-mass spectroscopy of O14 excited states

Excited states in $^{14}\mathrm{O}$ have been investigated both experimentally and theoretically. Experimentally, these states were produced via neutron-knockout reactions with a fast $^{15}\mathrm{O}$ beam and the invariant-mass technique was employed to isolate the $1p$ and $2p$ decay channels and determine their branching ratios. The spectrum of excited states was also calculated with the shell model embedded in the continuum that treats bound and scattering states in a unified model. By comparing energies, widths, and decay branching patterns, spin and parity assignments for all experimentally observed levels below 8 MeV are made. This includes the location of the second ${2}^{+}$ state that we find is in near degeneracy with the third ${0}^{+}$ state. An interesting case of sequential $2p$ decay through a pair of degenerate $^{13}\mathrm{N}$ excited states with opposite parities was found where the interference between the two sequential decay pathways produces an unusual relative-angle distribution between the emitted protons.

From Sequential Processes to Multifragmentation in Proton Reactions with Gold

The distribution of relative angles between the intermediate mass fragments has been measured and analyzed for thermal multifragmentation in p + Au collisions at 2.1, 3.6 and 8.1 GeV. The analysis has been done on an event by event basis. The multibody Coulomb trajectory calculations of all charged particles have been performed starting with the initial break-up conditions given by the combined model with the revised intranuclear cascade (INC) followed by the statistical multifragmentation model. The measured correlation function was compared with the calculated one to find the actual time scale of the intermediate mass fragment (IMF) emission. It found transition from sequential evaporation for p(2.1 GeV) + Au to simultaneous multibody decay of a hot and expanded nuclear system in case of p(8.1 GeV) + Au.

Search for the electromagnetic decay ofΔ(1232)resonance in nuclear matter

In order to inquire into the existence and significance of non-nucleonic degrees of freedom in the intermediate-energy regime, the production of protons and high-energy photons (E{sub {gamma}}{gt}30 MeV) emitted in the reaction {sup 36}Ar+{sup 27}Al at 95 MeV/nucleon has been studied. The quantitative analysis of the ({gamma}-p) invariant-mass and relative-angle distributions shows evidences of {Delta}(1232)-resonance excitation and {Delta}{r_arrow}N{gamma} decay. Experimental data are in agreement with microscopic theoretical calculations. {copyright} {ital 1998} {ital The American Physical Society}

Search for Delta (1232)-resonance excitation in heavy-ion collisions around 100 MeV/nucleon.

Correlations among protons and neutral pions emitted in the reaction $^{36}\mathrm{Ar}$+$^{27}\mathrm{Al}$ at 95 MeV/nucleon have been studied. The analysis of the (${\ensuremath{\pi}}^{0}\ensuremath{-}p$) invariant-mass and relative-angle distributions shows evidences of $\ensuremath{\Delta}(1232)$-resonance excitation. The experimental data are in agreement with the predictions of microscopic theoretical calculations.

Evidence for simultaneous breakup in reactions with relativistic α-projectiles

The relative-angle distributions of IMFs, studied for the system α + 197Au at 3.6 GeV/nucleon, show a strong suppression of small relative angles. By multi-body Coulomb trajectory calculations it is shown that the magnitude of this effect is very sensitive to the time scale of the IMF emission. The experimental angular distributions are well described assuming a fast breakup of the system with time less than 100 fm/c between IMF emissions.

Mechanism for the disassembly of excited 16O projectiles into four alpha particles.

The decay of excited {sup 16}O projectiles into the four alpha particle exit channel has been investigated. The projectiles, with bombarding energies of {ital E}/{ital A}=25 MeV, were excited through peripheral interactions with {sup 159}Tb target nuclei. A 4{pi} counter was used to detect both the projectile alpha particles and the light charged particles evaporated from the target nucleus. Criteria for selecting true {sup 16}O{r arrow}4{alpha} events with the minimum contamination from incorrectly identified events were examined. The distribution of relative angles between the four alpha particles in their center of mass frame was compared to simulations of {sup 16}O decay by sequential decay mechanisms. The relative angles were shown to be consistent with a sequential evaporation mechanism if a nonzero angular momentum is assumed for the excited projectile. The momentum distribution of the alpha particles in the reaction plane was examined and found to be anisotropic for high projectile excitation energies. This anisotropy was shown to be consistent with Coulomb interactions between the first emitted alpha particle and the target nucleus, which would indicate that the lifetime of the projectile is very short, on the order of 10{sup {minus}22} s.