Understanding the role of ion interactions in soluble salt flotation

ManuscriptThere is anecdotal evidence for the significant effects of salt ions on the flotation separation of minerals using process water of high salt content. Examples include flotation of soluble salt minerals such as potash, trona and borax in brine solutions. Although some of the effects are expected, some do not seem to be encompassed by classical theories of colloid science. Several experimental and modeling techniques for determining solution viscosity, surface tension, bubble-particle attachment time, contact angle, atomic force microscopy, sumfrequency vibrational spectroscopy and molecular dynamics simulation have been used to provide further information on air-solution and solid-solution interfacial phenomena, especially the interfacial water structure due to the presence of dissolved ions. These studies indicate that the ion specific effect is the most significant factor influencing flotation in brine solutions

Evaluation of the relationship between stylohyoid complex morphology and maxillary/mandibular position using cone beam computed tomography

Background: The aim of this study was to examine the morphologic features of the stylohyoid complex (SHC) and its relation to maxillomandibular position using three-dimensional cone beam computed tomography (CBCT) images. Materials and methods: CBCT images from 157 individuals (74 females, 83 males) were analysed in this study. SHC length, width, and sagittal and transverse angles were measured. The subjects were grouped as skeletal class I, II, and III in order to determine the relative positions of the maxilla and mandible in the sagittal plane and as hypodivergent, normodivergent, and hyperdivergent according to the vertical rotation of the mandible in relation to the skull base. Mann-Whitney U and Kruskal-Wallis H tests were used for statistical analysis. Results: Mean SHC length was 23.56 ± 8.05 mm on the right side and 22.0 ± 6.51 mm on the left; mean SHC width was 3.31 ± 1.40 mm on the right and 2.93 ± 1.30 mm on the left. Mean sagittal angle was 27.43 ± 6.75° on the right side, 27.70 ± 6.51° on the left; mean transverse angle was 70.39 ± 4.59° on the right side and 71.79 ± 4.99° on the left. The only significant difference based on skeletal classification was greater SHC length among males compared to females in the class III group (p < 0.05). Conclusions: No significant relationship was observed between SHC morphology and position of the maxilla or mandible. However, the gender difference observed among class III subjects suggests that SHC morphology may be affected by craniofacial morphology. Maxillofacial surgeons should investigate this anatomical landmark variation before surgical interventions involving this region, such as temporomandibular joint procedures

In-plant testing of membranes to treat electroplating wastewater

This is the final report submitted for the work performed under the NASA Cooperative Agreement NCC3-301 for the project entitled 'In-Plant Testing of Membranes To Treat Electroplating Waste water'. The main objective of the research project was to determine if the crosslinked polyacrylic acid salt films developed by NASA scientists could be used for heavy metal removal from the wastewater generated by the metals-finishing or electroplating industry. A variety of tasks identified in the original proposal were completed. These included: (1) analysis of our industrial partner Aetna Plating's zinc electroplating process and its wastewater treatment needs for zinc removal; (2) design and construction of a laboratory-scale unit to continuously supply and remove the ion exchange films from the zinc wastewater; (3) performance of a series of runs on such a unit to determine its operating characteristics; and (4) design of a prototype unit for use at the industrial site. In addition, there were a number of tasks that had not been identified in the original proposal but were later judged to be necessary for the successful completion of the project. These were: (1) batch equilibrium and kinetic experiments with analysis of the experimental results to accurately determine the equilibrium and kinetic parameters for the ion exchange films; (2 ) simulation studies for proper design of the prototype unit; and (3) preliminary runs to exchange the films from H form to Calcium form

A Search for Vector Diquarks at the CERN LHC

Resonant production of the first generation vector diquarks at the CERN Large Hadron Collider (LHC) is investigated. It is shown that the LHC will be able to discover vector diquarks with masses up to 9 TeV for quark-diquark-quark coupling alpha_(D)=0.1 and 4 TeV for alpha_(D)=5x10^(-4).Comment: 9 pages, 4 tables, 4 figure

Short-ranged ordering for improved mean-field simulation of disordered media: insights from refractory-metal high-entropy alloy carbonitrides

Multi-principal element materials (MPEMs) have been attracting a rapidly growing interest due to their exceptional performance under extreme conditions, from cryogenic conditions to extreme-high temperatures and pressures. Despite the simple conceptual premise behind their formation, computational high-throughput first-principles design of such materials is extremely challenging due to the large number of realizations required for sufficient statistical sampling of their design space. Furthermore, MPEMs are also known to develop short-ranged orderings (SROs) which can play a significant role in their stability and properties. Here, we present an expedient and efficient first-principles computational framework for assessing the compositional and mechanical properties of MPEMs, including SRO effects. This heuristic methodology systematically corrects phase-averaged free-energies of MPEMs to include SRO phases, while imposing constraints for materials design. To illustrate the methodology, we study the stability and mechanical properties of equi-molar refractory-metal high-entropy alloy carbonitrides (RHEA-CNs) such as ZrNbMoHfTaWC3N3. We show that SRO, arising due to preferential neighboring among refractory metals, is necessary for thermodynamic and mechanical stability and to satisfy the imposed design criteria, leading to complex compositions for which their molar fraction and mechanical properties are predicted.Comment: 7 pages, 4 figures, and 1 table. Supplemental Material of 20 pages, 10 figures, and 4 tables. 17M

Anatomical evaluation of nasopalatine canal on cone beam computed tomography images

Background: Nasopalatine canal (NPC) (incisive canal) morphology is important for oral surgery techniques carried out on the maxilla, in the treatment of naso- palatine cyst, palatal pathologies that require a surgical intervention. Materials and methods: The morphology of NPC was classified in sagittal, coronal and axial planes on the cone beam computed tomography (CBCT). The length of NPC was found by measuring the distance between the mid-points of nasopalatine foramen and incisive foramen. The numbers, shapes and diameters of incisive and nasopalatine foramina were examined. Nasopalatine angle present between the NPC and the palate and anterior to the NPC was measured.  Results: In the sagittal plane, the shape of NPC was classified in six groups: 26.7% hourglass, 14.7% cone, 13.3% funnel, 16.0% banana, 28.7% cylindrical and 0.7% reverse-cone-shaped. In the coronal plane, shape of NPC was classified in three groups: 63.3% Y-shaped, 36.0% single canal, 0.7% double canal and external border of NPC was classified in four groups: 26.7% U, 28.7% Y, 44.0% V and 0.7% reverse-V-shaped. In the axial plane, the shape of nasopalatine foramen, incisive foramen and NPC at the mid-level was evaluated. The shape of the canal was detected as four types at three evaluated levels: round, oval, heart- and triangle-shaped. It was seen in every three axial planes that the round group is more than the others.  Conclusions: The morphological properties and variations of NPC should be con- sidered with a correct radiological evaluation so as to prevent the complications and improper practices in local anaesthesia, maxillary surgery and implant surgery practices. Especially dentists, otolaryngologist and plastic surgeons need to know the anatomy and variations of NPC.

H\u3csup\u3e+\u3c/sup\u3e-H\u3csup\u3e-\u3c/sup\u3e coincidences from the three-body dissociation of excited H\u3csub\u3e3\u3csup\u3e+\u3c/sup\u3e\u3c/sub\u3e

The laboratory energy distribution of protons in coincidence with an H- ion, resulting from the dissociation of excited H3+, has been measured for H+-H- pairs emitted along the beam for 4.0-keV H3+-He collisions. An approximate energy distribution of H+-H- pairs for the collinear configuration of the dissociation products is obtained by transforming the measured laboratory spectrum to the H3+ center-of-mass (c.m.) frame. Coincidence data suggest that the reaction producing H+-H- pairs where the H+ ion has near-zero energies (3+ ions using a full configuration-interaction calculation with a basis set of atomic orbitals consisting of 1s, 1s’, 1p’, 2s, and 2p centered on the protons forming an isosceles (C2vsymmetry) or an equilateral (D3h symmetry) triangle. The states leading to asymptotic H++H++H- limits have been identified by calculating 〈1/r12〉-1, the inverse of the expectation value of the electron-electron repulsion term. The states identified by this procedure have adiabatic Born-Oppenheimer energies of 40–45 eV above the H3+ ground state at the H3+ equilibrium separation. The limits on the total available internal energy to be shared by the three dissociation products that one obtains from the experimentally determined H+-H- coincidence spectrum are consistent with the identified H3+ excited states