Tube coupling device

A first annular ring of a tube coupling device has a keyed opening sized to fit around the nut region of a male coupling, and a second annular ring has a keyed opening sized to fit around the nut of a female coupling. Each ring has mating ratchet teeth and these rings are biased together, thereby engaging these teeth and preventing rotation of these rings. This in turn prevents the rotation of the male nut region with respect to the female nut. For tube-to-bulkhead locking, one facet of one ring is notched, and a pin is pressed into an opening in the bulkhead. This pin is sized to fit within one of the notches in the ring, thereby preventing rotation of this ring with respect to the bulkhead

Ripples of Learning: A Middle School Teacher's Application of Content and Pedagogy Learned in the ESSEA Online Earth System Science Course

This article provides an overview of an Earth System Science Education Alliance (ESSEA) online professional development course for middle school classroom teachers. The course uses real-world events to develop content understandings of Earth system science, and it models best practices for age appropriate pedagogy. Topics include a brief description of the course itself and of efforts to evaluate its efficacy. The article is also available in printable form, and a video clip is included. Educational levels: Graduate or professional

Universal corner entanglement from twist operators

The entanglement entropy in three-dimensional conformal field theories (CFTs) receives a logarithmic contribution characterized by a regulator-independent function $a(\theta)$ when the entangling surface contains a sharp corner with opening angle $\theta$. In the limit of a smooth surface ($\theta\rightarrow\pi$), this corner contribution vanishes as $a(\theta)=\sigma\,(\theta-\pi)^2$. In arXiv:1505.04804, we provided evidence for the conjecture that for any $d=3$ CFT, this corner coefficient $\sigma$ is determined by $C_T$, the coefficient appearing in the two-point function of the stress tensor. Here, we argue that this is a particular instance of a much more general relation connecting the analogous corner coefficient $\sigma_n$ appearing in the $n$th R\'enyi entropy and the scaling dimension $h_n$ of the corresponding twist operator. In particular, we find the simple relation $h_n/\sigma_n=(n-1)\pi$. We show how it reduces to our previous result as $n\rightarrow 1$, and explicitly check its validity for free scalars and fermions. With this new relation, we show that as $n\rightarrow 0$, $\sigma_n$ yields the coefficient of the thermal entropy, $c_S$. We also reveal a surprising duality relating the corner coefficients of the scalar and the fermion. Further, we use our result to predict $\sigma_n$ for holographic CFTs dual to four-dimensional Einstein gravity. Our findings generalize to other dimensions, and we emphasize the connection to the interval R\'enyi entropies of $d=2$ CFTs.Comment: 26 + 15 pages, 6 + 1 figures, 4 + 1 tables; v2: minor modifications to match published version, references adde

Achieving Atomically Smooth Surfaces and Ultra Sharp Platinum-Iridium Tips for Deposition of Organic Molecules

Organic materials are used in traditional solar cells and in flexible electronics. Unfortunately, the conductivities of organic semiconductors are significantly lower than their inorganic counterparts. This project examines the crucial first steps to enhancing the conductivities of these organic materials by crystallization via surface reconstructions. For this, the surface must be not only atomically smooth, but also atomically clean because there must be both enough room for the molecule to lie on and no possible adsorbates for the deposited material to react with. In this work, we looked at two substrates, gold and silicon. For the gold, we examined two annealing methods: hot plate and flame annealing. The hot plate method is the more viable, producing terrace widths of ~150nm, which is 50nm wider than achieved by flame anneal. For the silicon, a simple cleaving method in a nitrogen environment produced step edges of width ~20nm. These surfaces are characterized with Scanning Tunneling Microscopy (STM), however, atomic resolution has yet to be achieved in either case, possibly due to other adsorbates obscuring the surface. For the best STM images, we also need an atomically sharp, conductive tip. To achieve this, we used a two-step procedure for electrochemically etching platinum-iridium wire. The final step is a micro-polishing etch which utilizes H2SO4 to finely etch the tip down to exhibit radii of curvature of 70-100 nanometers with completion determined visually. In order to improve on this process, we are currently developing a circuit that will electrically determine completion which will result in more reproducible tips.https://engagedscholarship.csuohio.edu/u_poster_2017/1027/thumbnail.jp

ORTHOPEDIC LEG BRACE

Knee braces generally have been rigid in both the knee bending direction and in the knee straightening direction unless a manually operated release is incorporated in them to allow the knee to bend. Desirably a braced knee joint should effectively duplicate the compound, complex, actions of a normal knee. The key to knee braces is the knee joint housing. The housing herein carries a number of cam action pawls. with teeth adapted to engage the internal teeth of a ratchet ring mounted in the housing. Cam action return springs and the shape of the cam action pawl teeth allow rotation of the ratchet ring in a leg straightening direction while still supporting a load. The leg can then be extended during walking while at the same time being prevented by the cam action pawls from buckling in the knee bending direction

John Wesley: the synthesis of John Calvin and Martin Luther

Typewritten sheets in cover. Thesis (M.A.)--Boston University Bibliography: p. 90-94

New initiators for the ring-opening polymerisation of lactones

This thesis describes the preparation of new yttrium and indium phosphasalen catalysts for the stereocontrolled ring-opening polymerisation of rac-lactide. Systematic ligand modification was performed by changing the size of the phosphine substituents, the identity of the central donor of the diimine bridge, and through increasing the steric bulk at the ortho and para phenolate positions. The coordination chemistry of the final complexes was then explored with full characterisation by multinuclear NMR spectroscopy, elemental analysis or high-resolution mass spectrometry, and in most cases, single crystal X-ray diffraction. Yttrium phosphasalen compounds were found to be active initiators for the ring-opening polymerisation of rac-lactide, affording moderately isotactic polymers. The level of stereocontrol was shown to be influenced by the nature of the phosphine substituents, the diimine bridge, and to a limited extent, the size of the ortho phenolate substituents. The stereocontrol was observed to change when the diimine bridge donor atom was changed, with an NH substituent yielding isotactic enchainment (Pi = 0.72) and an O donor yielding moderately heterotactic (Ps = 0.73) enchainment. Indium phosphasalen compounds were similarly active for ROP, affording isotactic polymers, with one exception, which afforded atactic PLA. The level of stereocontrol was found to correlate with the flexibility of the diimine bridge and largely by the size of the ortho phenolate substituents. In the best cases, highly isotactic polylactide was afforded (Pi = 0.87 at 298 K) concurrent with fast rates, showcasing one of the best performing initiators in the stereocontrolled ring-opening polymerisation of raclactide. Finally, an yttrium phosphasalen complex was applied for the ring-opening polymerisation of three large macrolactones: ω-pentadecalactone (C15), ω-nonadecalactone (C19) and ω- tricosalactone (C23). A comparison is made between yttrium phosphasalen and aluminium salen complexes as initiators for these monomers, showing that with the former, higher rates (minute vs. hour timescales) are observed. The polymerisations of macrolactones are generally more challenging as they are entropically driven, hence the thermodynamic parameters are also uncovered, showing that high conversions (near-quantitative) remain feasible, with molecular weights up to 32 kg mol-1, even using ring sizes up to C23.Open Acces