Full Separation Research Articles

Low-Dimensional Invariant Embeddings for Universal Geometric Learning

AbstractThis paper studies separating invariants: mappings on D-dimensional domains which are invariant to an appropriate group action and which separate orbits. The motivation for this study comes from the usefulness of separating invariants in proving universality of equivariant neural network architectures. We observe that in several cases the cardinality of separating invariants proposed in the machine learning literature is much larger than the dimension D. As a result, the theoretical universal constructions based on these separating invariants are unrealistically large. Our goal in this paper is to resolve this issue. We show that when a continuous family of semi-algebraic separating invariants is available, separation can be obtained by randomly selecting $$2D+1 $$ 2 D + 1 of these invariants. We apply this methodology to obtain an efficient scheme for computing separating invariants for several classical group actions which have been studied in the invariant learning literature. Examples include matrix multiplication actions on point clouds by permutations, rotations, and various other linear groups. Often the requirement of invariant separation is relaxed and only generic separation is required. In this case, we show that only $$D+1$$ D + 1 invariants are required. More importantly, generic invariants are often significantly easier to compute, as we illustrate by discussing generic and full separation for weighted graphs. Finally we outline an approach for proving that separating invariants can be constructed also when the random parameters have finite precision.

(Invited) Recovery Of Silver And Silicon From EoL PV Modules

Photovoltaic modules global expansion has been dynamic over the last 20 years and is on the verge of becoming massive with the necessary ongoing energy transition. This development raises legitimate concerns of i) raw materials availability and ii) handling of modules as a waste after their decommissioning. End of Life (EoL) modules are indeed a powerful source of critical raw materials that worth being fully exploited and optimized to reduce the demand on natural resources and energy (>50MWh/t of PC-Si) to produce fresh modules whilst addressing the matter of wastes. We shall know that 6 tons of natural resources are needed to produce one ton of PV-grade Si, and the share of critical material Ag for PV production accounts already for more than 13% of global consumption. However, EoL module recycling has been poorly developed so far, mostly because of the difficult delamination stage necessary to release precious metals and Silicon. Different approaches, involving shredding, machining, solvents, flashing light have been investigated by different institutes or companies to delaminate the module structure and recycle metals, but none of them successfully demonstrated the recovery at large scale, suffering from a lack of purity, efficiency or scalability. In this context, ROSI developed an innovative route coupling different key steps to produce Silver and Silicon at industrial scale by recycling EoL modules. In order to address the varsity of polymer structures in PV panels, a thermal process based on pyrolysis ensures a generic approach of delamination to convert 100% of polymers into gas, thus releasing cell fragments. A mild chemical etching step then achieves the full separation of Silver fingers from the surface of Silicon, avoiding the use of harsh chemicals generally used in the recovery of metals from electronic wastes. A dedicated sortation process finally allows to recover high purity glass, copper, Silicon and Silver as depicted in Figure 1.Based on the thermal behaviour of different mixes of polymers, pyrolysis process has been optimized to ensure the full conversion of polymers in gas whilst limiting thermal budget regardless of the initial composition of the PV module. This optimization phase will be presented and coupled with the mild wet etching technology developed to obtain silver fingers. Characterizations of recoveredmaterials will be presented, together with their high value applications. Figure 1

Improved adeno-associated virus empty and full capsid separation using weak partitioning multi-column AEX chromatography.

Recombinant adeno-associated virus (rAAV) empty and full capsid separation has been a topic of interest in the rAAV gene therapy community for many years and the anion exchange chromatography (AEX) step has undergone various process optimizations to improve rAAV empty capsid separation, including AEX stationary phase, mobile phase, and process parameters. Here, we present a new AEX method that employs both weak partitioning chromatography (WPC) and multi-column chromatography (MCC) to achieve improved full rAAV percentage in the AEX pool. The WPC technology allows empty rAAV to be displaced by full rAAV during loading, while the MCC technology enables parallel column processing which further increases AEX step productivity. Our results show that, compared to baseline AEX batch chromatography, the AEX-WPC-MCC method demonstrated improvements in both AEX pool full rAAV percentage (∼ 20% increase) and rAAV genome recovery (∼ 20% increase). As a result, the productivity (full capsid generated per liter of AEX column per hour of processing time) of the AEX step increased by ∼34-fold from the baseline AEX batch run to the AEX-WPC-MCC run. It is foreseeable that this AEX-WPC-MCC method could find applications in large-scale rAAV manufacturing processes to improve AEX yield and reduce the cost of goods of rAAV manufacturing.

Tuning mobile phase properties to improve empty and full particle separation in adeno-associated virus productions by anion exchange chromatography.

In the past decade, recombinant adeno-associated virus (rAAV) has gained increased attention as a prominent gene therapy technology to treat monogenetic diseases. One of the challenges in rAAV production is the enrichment of full rAAV particles containing the gene of interest (GOI) payload. By adjusting the mobile phase properties of anion-exchange chromatography (AEX), it was demonstrated that empty and full separation of rAAV was improved in monolith based preparative AEX chromatography. When compared to the baseline method using NaCl, the use of tetraethylammonium acetate (TEA-Ac) in the AEX mobile phase resulted in enhanced resolution from 0.75 to 1.23 between "Empty" and "Full" peaks by salt linear gradient elution, as well as increased the percentage of full rAAV particles from 20% to 36% and genome recovery from 59% to 62%. Furthermore, a dual wash plus step elution AEX method was developed. Wherein, the first wash step harnesses TEA-Ac to separate empty and full capsids, which is followed by a second wash step that ensures no TEA-Ac salt is carried over into AEX eluate. The resulting optimized AEX purification method has the potential to be adapted for manufacturing and purification processes involving various rAAV production platforms that experience empty and full rAAV separation challenges.

New variable separation solutions and localized waves for (2+1)-dimensional nonlinear systems by a full variable separation approach

A full variable separation approach is firstly proposed for (2+1)-dimensional nonlinear systems by extending the well-established multilinear variable separation approach through the assumption that the expansion function is composed of full variable separated functions, namely, functions with respect to only one spacial or temporal argument. Taking the (2+1)-dimensional Boiti-Leon-Manna-Pempinelli equation, the Nizhnik-Novikov-Veselov equation and the dispersive long wave equation as examples, new full variable separation solutions are obtained with several arbitrary one dimensional functions. Especially, a common formula for some suitable physical quantities is discovered. By taking the arbitrary functions in different explicit expressions, the solutions can be used to describe plentiful novel nonlinear localized waves, which might be non-travelling waves as the spacial and temporal variables are fully separated into different functions. In particular, some new hybrid solitary waves, which can pulsate periodically, appear and/or decay with an adjustable lifetime, are discovered through the on-site interactions between a doubly periodic wave and a ring soliton, a four-humped dromion and a four-humped lump, and a doubly periodic wave and a cross type solitary wave. Nonlinear wave structures and their dynamical behaviours are discussed and graphically displayed in detail.

JUSTIFICATION OF AUGER CLOD-CRUSHER OF THE POTATO HARVESTER

The reasons for the low degree of mechanization of potato harvesting are analyzed and it is proposed to equip the potato harvester machine with a passive auger clod-crusher. It will make possible to loosen the surface layer of the field with ridges, to grind plant residues and tubers, moving them with the loosened soil to the inter-field space, excluding their access to the potato harvester. The application of a clod-crusher will contribute to the full separation of the tuberous soil mass. A number of structural and technological parameters of auger clod-crusher were determined.

A New Charge-Ordered Molecular Conductor: κ-(BEDT-TTF)2K+(18-crown-6)[CoII(NCS)4]∙(H2O)

A new molecular conductor, i.e., κ-(BEDT-TTF)2K+(18-crown-6)[CoII(NCS)4]∙(H2O), is semiconductive with substantial charge gap values (ΔE) of 0.57 eV (measured) and 0.37 eV (calculated). There is a full band separation despite formal average charge on BEDT-TTF of +0.5 and κ(kappa)-type packing of BEDT-TTF dimers that favors high conductivity. X-ray crystal structure analysis reveals complete charge ordering with full Coulomb charge on unique BEDT-TTF radical cations A (QA = +1), while unique molecules B are uncharged (QB = 0). Geometries of A (flat) and B (bent) differ considerably and are in accordance with the ascribing charges. Charge segregation is enhanced by forming tight face-to-face BEDT-TTF dimers AA (QAA = +2) and BB (QBB = 0). Strongly interacting double-charged dimers AA form “superstripes” running along a that are interleaved along b with chains of neutral dimers BB. Peculiar extremely thick (13.7 Å) four-decker insulating anion layers cast strong Coulomb potential onto the conductive layers predetermining charge localization in the latter.

The multiplicity of massive stars in the Scorpius OB1 association through high-contrast imaging

Context. Despite past efforts, a comprehensive theory of massive star formation is still lacking. One of the most remarkable properties of massive stars is that almost all of them are found in binaries or higher-order multiple systems. Since multiplicity is an important outcome parameter of a star formation process, observations that cover the full companion mass ratio and separation regime are essential to constrain massive star formation theories. Aims. We aim to characterise the multiplicity properties of 20 OB stars (one of which turned out to be a foreground object) in the active star-forming region Sco OB1 in the separation range 0.″15–6″ (∼200−9000 AU), using high-contrast imaging observations. These observations enabled us to reach very large magnitude differences and explore an as of yet uncharted territory of companions around massive stars. Methods. We used VLT/SPHERE to simultaneously observe with IFS and IRDIS, obtaining high-contrast imaging observations that cover a field of view (FoV) of 1.″73 × 1.″73 in YJH bands and 11″ × 12.″5 in K1 and K2 bands, respectively. We extracted low-resolution IFS spectra of candidate companions within 0.″85 and compared them with PHOENIX and ATLAS9 atmosphere models to obtain an estimate of their fundamental parameters. Furthermore, we retrieved an estimate of the mass and age of all sources in the larger IRDIS FoV. The observations reached contrast magnitudes of ΔK1 ∼ 13 on average, so we were able to detect sources at the stellar-substellar boundary. Results. In total, we detect 789 sources, most of which are likely background sources. Thirty objects that are estimated to be in the stellar mass regime have a 20% or lower probability of being spurious associations. We obtain SPHERE companion fractions of 2.3 ± 0.4 and 4.1 ± 0.8 for O- and B-type stars, respectively. Splitting the sample between more massive (> 20 M⊙) and less massive stars (< 20 M⊙), we obtain companion fractions of 2.3 ± 0.4 and 3.9 ± 0.7, respectively. Including all previously detected companions, we find a total multiplicity fraction of 0.89 ± 0.07 for separations in the range of ∼0−12 000 AU. Conclusions. With SPHERE, we are probing an unexplored area in the magnitude versus separation diagram of companions, which is crucial to achieve a complete overview of the multiplicity properties of massive stars and ultimately improve our understanding of massive star formation.

Oblique collisions of three wet spheres

Oblique collisions of three solid spheres coated with thin viscous layers are simulated, both to elucidate the interesting physics of the collision outcomes and to lay the groundwork for a new approach to modeling flows of many wet particles. Included in the analysis are fluid viscous and capillary forces, as well as solid contact and friction forces. A novel approach is developed based on a rotating polar coordinate system for each particle pair in near contact, including the possibility that a given particle is in simultaneous contact with both other particles. As the Stokes number (a dimensionless ratio of particle inertia and viscous forces) is increased, the collision outcome progresses from full agglomeration (all three particles sticking together due to viscous and capillary forces) to partial agglomeration (two particles sticking together while the third one separates) to full separation (all three particles separating post-collision). The results are also sensitive to various physical and geometrical properties, such as the ratio of fluid film thickness to particle diameter, the coefficient of friction, and the collision angles.

Posterior Palatal Expansion via Subnasal Endoscopy (2PENN) for Maxillary Deficiency: A Pilot Study.

Surgically assisted rapid palatal expansion (SARPE) addresses transverse maxillary deficiency, a known contributor to nasal obstruction. The purpose of this study was to assess the feasibility, preliminary outcomes, and safety of posterior palatal expansion via subnasal endoscopy (2PENN), a modified SARPE procedure, aimed at achieving anterior and posterior maxillary expansion. This prospective case series included consecutive adult patients with findings of transverse maxillary deficiency that underwent the 2PENN procedure from 4/2021 to 4/2022. Patients completed pre- and post-operative clinical evaluations, Nasal Obstruction and Septoplasty Effectiveness (NOSE) questionnaires, and computed tomography (CT), with measures including expansion at the level of the posterior nasal spine (PNS), first maxillary inter-molar distance (IMD), and anterior nasal spine (ANS). The cohort (N = 20) was middle-aged (39 ± 11 years), predominantly male (80%), and overweight (BMI 28 ± 4 kg/m2 ). The majority (85%) of patients had sleep breathing issues, of which 10 (59%) had polysomnography-confirmed obstructive sleep apnea (OSA). Full anterior-posterior separation of the mid-palatal suture line was evident on all post-operative CT scans, with mean expansion at the PNS of 3.6 ± 1.3 mm, IMD of 6.1 ± 1.6 mm and ANS of 7.0 ± 1.6 mm (p < 0.001). Following surgery, mean NOSE scores improved from 57 ± 23 to 14 ± 13 (p < 0.001). One patient required maxillary antrostomy for post-operative sinusitis. 2PENN is an effective and safe technique for achieving both anterior and posterior maxillary expansion in patients with transverse maxillary deficiency. Further study is warranted to better understand the effect of 2PENN in patients with OSA, particularly as it relates to improving pharyngeal patency. 4 Laryngoscope, 134:1970-1977, 2024.

Adeno-associated viral capsid stability on anion exchange chromatography column and its impact on empty and full capsid separation

Recombinant adeno-associated viral vector (rAAV) mediated gene therapy is gaining traction in treating genetic disorders. Current rAAV production systems yield a mixture of capsids largely devoid of the transgene (empty capsid) compared with the desired therapeutic product (full capsid). Anion exchange chromatography (AEX) is an attractive method for separating empty and full AAV capsids because of its scalability. Resin types and buffer composition are key considerations for AEX and must support capsid stability to be suitable for downstream processing. We examined the impact of binding durations (0-8 h) using various binding ionic strengths (15-75mM), pH (7.5-9.0), resin chemistry (POROS XQ, POROS HQ, POROS I, and BIA QA monolith), and proprietary Q resins with different ligand densities for effects on capsid stability. Empty capsids were altered upon extended binding, leading to retention time shifts and loss of resolution between empty and full capsids. Viral capsid protein analysis reveals that full capsids have more viral capsid protein 3 (VP3) proteins than empty capsids. Analytical hydrophilic liquid chromatography showed that empty capsid retention time shift is accompanied by changes to the empty capsid's native VP3 protein. Among the potential stabilizing additives considered, magnesium chloride was the most effective at reducing negative impacts caused by extended binding.

Silver ion chromatography enables the separation of 2-methylalkylresorcinols from alkylresorcinols.

Alkylresorcinols (∑ARs) is the generic term for a highly varied class of lipids found mainly in cereals. These bioactive compounds consist mainly of 5-alkylresorcinols (ARs), which differ in length, unsaturation, and substituents on the alkyl side chain on C-5. In addition, 2-methyl-5-alkylresorcinols (mARs) are scarcely studied minor compounds that are supposed to exist with the same structural diversity. In the first step, ∑ARswere enriched by solid-phase extraction from wheat grain and quinoa seed extracts. The subsequent application of silver ion chromatography (SIC), silica gel, coated with 20% AgNO3 , then deactivated with 1% water) enabled an unprecedented full separation of saturated mARs from conventional ARs. Specifically, saturated mARs were eluted with n-hexane/ethyl acetate (92:8, v/v), and conventional ARs with n-hexane/ethyl acetate (80:20, v/v). The unpreceded separation indicated that the SIC method could be useful not only for separations according to the degree of unsaturation, but also in the case of steric hindrance by additional (alkyl) substituents. Continued fractionation enabled the collection of unsaturated ARs in wheat and quinoa extracts. In this way, 35 ∑ARs (including five mARs) were detected by gas chromatography/mass spectrometry analysis in wheat and 45 ∑ARs (including 21 mARs) in quinoa. These included several low abundant and partly unknown ∑ARs such as 1,3-dihydroxy-5-tricosadienylbenzene.

Will the latest British reforms to rail passenger service procurement work?

In the 1990s Great Britain embarked on one of the most radical railway reforms undertaken anywhere in the world, with full vertical separation and privatisation of all aspects of the railway and the introduction of competition throughout the sector. However, since then Britain's railways have been plagued with multiple problems, most notably a failure to control costs, as well as multiple franchise failures and problems with developing sensible timetables, with consequent impacts on train performance. Multiple attempts to reform the initial model have failed and in 2018/2019 a fundamental review was undertaken which culminated in the publication of the Williams–Shapps plan for rail which proposes a major step back towards vertical integration with the establishment of a new government owned organisation to take charge both of infrastructure and services, although the latter will be operated by private companies under concessions. This paper reviews the reasons behind the problems experienced by Britain's railways – which led to the review – before setting out the proposed reforms and discussing whether they might solve the problems and what some of the critical success factors might be.

Applying machine learning methods for the analysis of two-dimensional mass spectra

In a measurement of isomeric yield-ratios in fission, the Phase-Imaging Ion-Cyclotron-Resonance technique, which projects the radial motions of ions in the Penning trap (JYFLTRAP) onto a position-sensitive micro-channel plate detector, has been applied. To obtain the yield ratio, that is the relative population of two states of an isomer pair, a novel analysis procedure has been developed to determine the number of detected ions in each state, as well as corrections for the detector efficiency and decay losses. In order to determine the population of the states in cases where their mass difference is too small to reach full separation, a Bayesian Gaussian Mixture model was implemented. The position-dependent efficiency of the micro-channel plate detector was calibrated by mapping it with ^{133}Cs^+ ions, and a Gaussian Process was trained with the position data to construct an efficiency function that could be used to correct the recorded distributions. The obtained numbers of counts of excited and ground-state ions were used to derive the isomeric yield ratio, taking into account decay losses as well as feeding from precursors.

Development and application of a supercritical fluid chromatography-tandem mass spectrometry method for the simultaneous determination of pantoprazole enantiomers in rat plasma

The study aimed to develop a supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) method for the enantioselective separation and quantification of pantoprazole in rat plasma. The method utilized protein precipitation with acetonitrile to prepare plasma samples. SFC was performed on an Acquity ultra-performance convergence chromatography (UPCC) system. An Acquity UPCC Trefoil™ CEL2 column was employed for enantioseparation, and isocratic elution was achieved using a mobile phase consisting of CO2-methanol (81:19, v/v). The detection of pantoprazole enantiomers and the internal standard phenacetin was carried out using a Xevo TQD triple quadrupole mass spectrometer in selected reaction monitoring mode with positive electrospray ionization. The developed method successfully achieved full separation of S- and R-pantoprazole enantiomers. Calibration curves were linear in the concentration range of 10–5000 ng/mL for both S- and R-pantoprazole. The method met the acceptance criteria for carry-over, accuracy, precision, extraction recovery, matrix effect, stability, and dilution integrity, demonstrating its stereoselectivity, sensitivity, accuracy, precision, and reliability. The validated method was then applied to investigate the toxicokinetics of racemic pantoprazole and evaluate the potential of chiral inversion between S- and R-pantoprazole in rats. Following oral administration of 200 mg/kg racemic pantoprazole once daily for 90 consecutive days, there was no significant difference in toxicokinetic parameters between the two enantiomers on both day 1 (single-dose experiment) and day 90 (multiple-dose experiment). This suggests that there is no enantioselectivity in the toxicokinetic behaviors of racemic pantoprazole in rat plasma. Additionally, bidirectional chiral inversion between S- and R-pantoprazole in plasma was observed after single-dose and multiple-dose oral administrations of S-pantoprazole (20, 100, and 200 mg/kg) or R-pantoprazole (200 mg/kg) to rats. Compared to single and low doses, there was no accumulation of each enantiomer in rat plasma following repeated and escalated dosing. Overall, this study provided the first report on the toxicokinetics of pantoprazole in rat plasma and presented the first SFC-MS/MS method for the simultaneous quantification of pantoprazole enantiomers in rat plasma.

Resolution limits of size exclusion chromatography columns identified from flow reversal and overcome by recycling liquid chromatography to improve the characterization of manufactured monoclonal antibodies

The flow reversal (FR) technique consists of reversing the flow direction along a chromatographic column. It is used to reveal the origin (such as poor column packing, active sites, or slow absorption/escape kinetics) for the resolution limit of 4.6 mm × 150 mm long columns packed with 1.7 μm 200 Å Bridge-Ethylene-Hybrid (BEHTM) Particles. These columns are used to separate manufactured monoclonal antibodies (mAb, ∼ 150 kDa) from their close impurities (or IdeS fragments, ∼ 100 kDa) by size exclusion chromatography (SEC). FR unambiguously demonstrates that the resolution limit of these SEC columns is primarily due to long-range flow velocity biases covering distances of at least 500 μm across the column diameter. This confirms the existence of center-to-wall flow heterogeneities which cause undesirable tailing for the mAb peak. Because the transverse dispersion coefficient (Dt=1.1 × 10−6 cm2/s) of mAbs across the column diameter is intrinsically low, the bandspreading of the mAb in a single flow direction is in part reversible upon reversing the flow direction. For the very same residence time in the column, the column efficiency is found to increase by +85% relative to that observed under conventional elution mode. The observed peak tailing of the mAb and its sub-units is not caused by active surface sites or by slow absorption/escape from the BEH Particles. Therefore, the most critical mAb impurities (hydrolytic degradation Fab/c and IdeS F(ab′)2 fragments) can only be successfully separated and quantified with acceptable accuracy by adopting alternate pumping recycling liquid chromatography (APRLC). APRLC enables the full baseline separation of the mAb and 100 kDa mAb fragments and partial separation of Fab/c and F(ab′)2 fragments after increasing the number of cycles to ten. It was made possible to accurately measure the relative abundances of the mAb (99.0 ± 0.1%), F(ab′)2 fragment (0.88 ± 0.03%), and Fab/c immunogenic fragment (0.13 ± 0.02%) in less than 45 min for a total mAb sample load of only 5 μg. Still, further improvements are needed to increase the sensitivity of the APRLC method and to reduce the solvent consumption by adopting narrow-bore 2.1 mm i.d. SEC columns.

Full Separation and Sequencing of Isomeric Proteoforms in the Middle-Down Mass Range Using Cyclic Ion Mobility and Electron Capture Dissociation.

Unambiguous identification of distinct proteoforms and their biological functions is a significant analytical challenge due to the many combinations of post-translational modifications (PTM) that generate isomeric proteoforms. Resulting chimeric tandem mass spectra hinder detailed structural characterization of individual proteoforms for mixtures with more than two isomers. Large isomeric peptides and intact isomeric proteins are extremely difficult to distinguish with traditional chromatographic separation methods. Gas-phase ion separation techniques such as ion mobility spectrometry (IMS) methods now offer high resolving power that may enable separation of isomeric biomolecules, such as peptides and proteins. We explored novel high-resolution cyclic ion mobility spectrometry (cIM) combined with an electro-magnetostatic cell for "on-the-fly" electron capture dissociation (ECD) for separation and sequencing of large isomeric peptides. We demonstrate the effectiveness of this approach on ternary mixtures of mono- and trimethylated isomers of histone H3 N-tails (∼5.4 kDa), achieving a complete separation of these isomers with an average resolving power of ∼400 and a resolution of 1.5 and with nearly 100% amino acid sequence coverage. Our results demonstrate the potential of the cIM-MS/MS(ECD) technology to enhance middle-down and top-down proteomics workflows, thereby facilitating the identification of near-identical proteoforms with essential biological functions in complex mixtures.

2-fluoro-1-methylpyridinium p-toluene sulfonate: a new LC-MS/MS derivatization reagent for vitamin D metabolites

Vitamin D analysis by MS faces several analytical challenges, including inefficient ionization, nonspecific fragmentation, interferences from epimers, isomers, and isobars, as well as very low concentration levels. In this study, we used 2-fluoro-1-methylpyridinium (FMP) p-toluene sulfonate for derivatization of vitamin D3 metabolites to increase detection sensitivity and allow for full chromatographic separation of vitamin D isomers and epimers. UHPLC-MS/MS was used for measurement of five vitamin D3 metabolites in human serum. Compared with Amplifex and 4-phenyl-1,2,4-triazolin-3,5-dion, the FMP p-toluene sulfonate reaction required less time to be performed. The method was optimized and validated to ensure accuracy, precision, and reliability. In-house and commercial quality control samples were used to assure the quality of the results for 25-hydroxyvitamin D3. The method showed very good linearity and intraday and interday accuracy and precision; coefficients of determination (r2) ranged between 0.9977 and 0.9992, relative recovery from 95 to 111%, and coefficient of variation from 0.9 to 11.3. Stability tests showed that the extracted derivatized serum samples were stable for 24 h after storage at −20°C; 24,25-dihydroxyvitamin D3 and 1,25-dihydroxyvitamin D3-FMP derivatives were stable for 1 week at −80°C. The method was applied to samples of healthy individuals for quantitative determination of vitamin D3, the two epimers of 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3.

Performance analysis of meta-morphing wing

To adapt to a dynamic mission environment, morphing wings change their outer shape dramatically. As the airfoil thickness grows, the leading-edge radius advances, making the leading-edge smoother and allowing the laminar air to resist full swing separation at greater angles of attack. In this paper, the gear rod mechanism with rack and pinion is installed on the wings. In addition to the gear rod mechanism, corrugated shapes given at the trailing edge for elastic deformation. Flaps are used primarily on the leading and trailing edges of the wing to increase the lift coefficient and camber of the wing. A morphing mechanism would achieve leading and trailing edge deflection as well as airfoil thickness deflection at the same time. The morphing wing model is designed in CATIA V5 software with NACA 2415 airfoil coordinates. Designed model is analyzed in ANSYS workbench with various angles of attack such as -100, 00, 50 and 100 with velocity 50 m/s as boundary conditions. Aerodynamic efficiency CL/Cd is calculated for morphing wing and compared with convention wing. Fuel consumption is one of the performance parameters that might be developed using the morphing wing concept. This morphing wing is a brand-new mechanism concept that focuses only on the mechanism rather than the materials.

Green and efficient separation of iron and phosphorus from high-phosphorus oolitic iron ore by reduction roasting without a dephosphorization agent

To provide a new method for the dephosphorization of high-phosphorus oolitic iron ore (HPOIO) by reduction roasting, the feasibility of the high-efficiency separation of iron and phosphorus by reduction roasting and magnetic separation process (RRMSP) without a dephosphorization agent was studied. The results showed that the full separation of iron and phosphorus was achieved without a dephosphorization agent. Under optimal conditions, powdery reduced iron (PRI) with 92.77% iron and 0.09% phosphorus content was produced. Iron recovery and dephosphorization reached 68.70% and 93.50%, respectively. In a weak reducing atmosphere, apatite was not reduced. A portion of the phosphorus in the iron minerals formed apatite, and the remaining phosphorus entered fayalite. Metallic iron and phosphorus minerals were physically separated. Compared with the addition of dephosphorization agent, clean production was realized without the addition of dephosphorization agent, but the iron recovery was not ideal; the economic benefits should be further studied in the future.