CFD simulations for predicting vertical upflow liquid nitrogen transfer line chilldown process using a 3D two-phase flow mixture model

Side-stream fermentation drives partial denitrification/anammox for enhanced nitrogen removal and anaerobic ammonium oxidation bacteria enrichment in a flocs-based continuous-flow anaerobic/aerobic/anoxic system.

Atmospheric intermediate volatile organic compounds （IVOCs） are complex mixtures. Due to the limited separation and identification capabilities of one-dimensional gas chromatography （1D-GC）， a large portion of atmospheric IVOCs-which often elute as unresolved or complex peaks-are categorized as an unspeciated complex mixture （UCM）. This constrains the accurate apportionment of atmospheric IVOCs. To address this problem， an alternative analytical method has been developed utilizing thermal desorption-flow modulation comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry （TD-FM GC×GC-TOF MS） to measure atmospheric IVOCs. Analytical optimization focused on fill and flush time within a 3-second modulation period， with optimal values determined as 2 870 ms and 130 ms， respectively， to maximize separation efficiency and signal response. Compounds were separated on a ZB-5HT column （20 m×0.18 mm×0.18 μm） as the first dimension， with a BP-50 column （5 m×0.25 mm×0.20 μm） serving as the second dimension. Helium was employed as the carrier gas with column pressures maintained at 254.4 kPa （first dimension） and 202.1 kPa （second dimension）. The following temperature program was used： 50 ℃ for 10 min， then increased to 300 ℃ at 10 ℃/min， with the final temperature held for 20 min. The MS was operated in electron impact （EI， 70 eV） ionization mode. Both the ion source and transfer line temperatures were set at 300 ℃. MS signals were recorded in full scan mode with a scan range of m/z 40 to m/z 800. During thermal desorption， the desorption temperature was set at 320 ℃， and the cold trap temperature was maintained at -10 ℃ to capture desorbed targets. The secondary desorption flow rate was set at 16 mL/min. Under these optimized conditions， the method demonstrated acceptable linearity， with correlation coefficients ranging from 0.922 3 to 0.998 4， for 69 selected targets spanning 1 to 20 ng/tube， with method detection limits （spiked at 1 ng/tube） between 0.010 7 and 0.410 1 ng/m3， with recoveries ranging from 80.4% to 136.0%. Relative standard deviation values among replicate samples （n=7） spiked at 1 ng/tube， 3 ng/tube， and 10 ng/tube levels were around 4.5%-33.9%， 3.2%-19.9% and 3.5%-18.6%， respectively. Application of the method to atmospheric IVOC samples collected from an urban site of Shanghai， revealed total IVOCs mass concentrations of 8.6-61.1 μg/m3. Of these， mass concentrations of 853 individual species identified by the present method comprised 96.2% of total IVOCs. Consequently，the newly developed method improved the identification rate for UCM. Importantly， the newly speciated aromatics， chlorinated IVOCs， and oxygenated IVOCs exhibited different emission sources distinct from those routinely monitored compounds. Therefore， this study established a reliable method for determining atmospheric IVOCs， offering strong data support for precise source apportionment of complex IVOCs in the atmosphere. Additionally， this method can be used to monitor IVOCs across various environmental metrics， thereby providing essential data to support the management and control of these compounds.

Stability factor for robust balancing of transfer lines under task processing time uncertainty

Non-destructive beam diagnostics are essential for low-energy medical cyclotrons, where even thin interceptive devices can severely degrade beam quality. We investigate an external fiber monitor (EFM) based on Ce-doped silica scintillating fibers that detects secondary radiation generated at existing beamline components of the 18 MeV Bern Medical Cyclotron beam transfer line (BTL). Three use cases were studied: (i) beam intensity monitoring around an electrically isolated, water-cooled beam dump; (ii) beam-loss monitoring around a 10 mm collimator under varying the beam focusing; and (iii) by steering a 6×6 mm beam spot on a beam dump. For case (i), the summed EFM signal exhibits a linear dependence on the current on target over nearly three orders of magnitude. In case (ii), a normalized EFM-based beam-loss proxy scales monotonically with an electrical loss proxy across several focusing settings. Furthermore, opposing-fiber signal ratios provide decoupled, monotonic sensitivity to horizontal and vertical beam displacements.

Implementation of In-Situ Vision System on Transfer Line to Improve Packaging Quality and Minimize Waste: Automotive Supplier Case Study

Abstract Surface contamination not only influences but in some cases even dominates the measured properties of two-dimensional materials. Although different cleaning methods are often used for contamination removal, commonly used spectroscopic cleanliness assessment methods can leave the level of achieved cleanliness ambiguous. Despite two decades of research on 2D materials, the true cleanliness of the used samples is often left open to interpretation. In this work, free-standing monolayer graphene and hexagonal boron nitride are annealed at different temperatures in a custom-built ultra-high vacuum heating chamber, connected to a scanning transmission electron microscope via a vacuum transfer line, enabling atomically resolved cleanliness characterization as a function of annealing temperature, while eliminating the introduction of airborne contamination during sample transport. While annealing at 200 °C already reduces contamination significantly, it is not until 400 °C or higher, where over 90% of the free-standing monolayer areas are atomically
clean. At this point, further contamination removal is mainly limited by defects in the material and metal contamination introduced during the sample transfer or growth. The achieved large, atomically clean areas can then be used for further nanoscale engineering steps or device processing, facilitating interaction with the material rather than contamination.

Reliable engineering of low-resistance metal semiconductor (M/S) contacts is critical for advancing indium oxide (In2O3) based semiconductor technologies. As device dimensions shrink to the micrometer regime, minimizing contact resistance becomes essential to ensure channel limited operation rather than contact dominated. In this study, we systematically optimized Ni/In2O3 contacts using mild rapid thermal annealing (RTA) at 250 °C in nitrogen ambient conditions compatible with back-end-of-line (BEOL) processing and evaluated their performance using the transfer line method (TLM). Ni/In2O3 TLM structures were fabricated via photolithography and liftoff, followed by RTA at varying durations. Quantitative TLM analysis demonstrated a substantial reduction in contact resistance (RC) to 6.24 Ω, normalized contact resistance (N · RC) to 1.25×10−1 Ω cm, specific contact resistivity (ρC) to 1.53×10−6 Ω cm2, and a short transfer length (LT) of 123 nm, all achieved without intentional doping or complex metallization. This process driven, BEOL compatible approach provides a robust route to low-resistance contacts in In2O3 thin films, enabling a reliable foundation for next generation low power, high performance oxide electronics.

Ultralow-temperature cryogenic transmission electron microscopy using a new helium flow cryostat stage.

The Beijing Electron Positron Collider II upgrade (BEPCII-U) has been proposed to optimize the maximum collision energy and data acquisition efficiency in higher energy region (>2.1 GeV). To achieve higher luminosity at higher energies, the number of superconducting radio frequency (SRF) cavities will be doubled. The cryogenic system of the BEPCII-U employs two cryogenic plants to provide the refrigeration for the three types of superconducting (SC) devices: SRF cavities, SC multi-function magnets (MFMs) and superconducting solenoid magnet (SSM). The cryogenic subsystem for SRF cavities has been upgraded from the original 500 W to 1 kW at 4.2 K due to the increased number of SRF cavities (4 cavities). The main tasks include the design of the cooling process, 499.8 MHz cavity cryomodules, local distribution valve boxes (LDVBs) and different types of multi-channel transfer lines (MCTLs) based on existing conditions. Meanwhile, the cryogenic subsystem for SC magnets has also been upgraded to enhance the reliability of the cryo-plant and to develop new SC MFM-cryomodules and associated valve boxes. The main tasks are including the design of the SC MFM-cryomodules, a cryogenic horizontal test stand (HTS) for SC magnets and working scheme for the main screw compressors (MSCs). The cryogenic system for the BEPCII-U has been designed, constructed and commissioned since the beginning of 2021, and the detailed design is presented in this paper.

This study investigates and validates the feasibility of a Charpy impact testing methodology conducted at 4K ultra-cryogenic temperatures using liquid helium (LHe). Conventional cryogenic impact tests are primarily performed at 77K using liquid nitrogen; however, with the increasing demand for hydrogen energy systems operating at lower temperatures, evaluating mechanical properties at temperatures below 20K has become essential. In this context, a new approach was developed to cool ISO 148-1 standard 316L stainless steel specimens by directly injecting LHe into a specially designed containment system. The injection was performed at a pressure of 9 psig, and it was experimentally confirmed that the specimen core temperature stabilized at approximately 4K within 45 seconds after LHe exposure. Subsequent Charpy impact testing at this temperature demonstrated reliable and repeatable results, confirming that sufficient thermal equilibrium had been achieved. The study not only demonstrates the technical feasibility of this cooling approach but also provides supporting data on the stability and reproducibility of mechanical property evaluation under ultra-low temperatures. In particular, the results offer significant insight into material behavior relevant for components exposed to cryogenic hydrogen conditions, such as storage tanks, transfer lines, and safety valves. The proposed methodology overcomes practical limitations of traditional testing setups by allowing efficient specimen cooling without requiring full-system cryogenic insulation. Therefore, this work provides a crucial reference framework for future material development and testing in support of next-generation hydrogen infrastructure, where accurate property data under extreme cryogenic conditions is critical for safe and efficient system design.

• Alternative cooling concept for superconducting cables in liquid hydrogen: indirect configuration by placing the cable in a helium-filled protective pipe to avoid material incompatibilities. • Thermal coupling by natural convection in stagnant helium as a contact gas: no circulation system for helium. • Experimental validation of a specific correlation for heat transfer by natural convection in enclosed spaces [ 1 ] for fluids with Prandtl numbers < 1 at cryogenic temperatures. This contribution presents conceptual designs for a hybrid power transfer line (PTL) with liquid hydrogen (LH 2 ) and high temperature superconductors (HTS). The synergetic combination of chemical and electrical energy transfer provides a high overall efficiency and large power density. To avoid critical material compatibility with hydrogen and improve safety aspects, one option is to place the HTS cable within the same cryostat but separated from the LH 2 flow by a protective pipe. A key challenge of this indirect cooling is the heat transfer capability from the cable to the hydrogen. To improve the thermal contact, the protective pipe is filled with helium as a contact gas. Evaluating the indirect cooling needs modelling of heat transfer by natural convection, which relies on empirical correlations. In this work, an experiment is designed to validate the correlations at cryogenic temperatures. The presented test set-up is of reduced geometric complexity and experiments are executed with liquid nitrogen (LN 2 ) at 77 K. The measurement series includes different cable sample topologies and the overall results show a good accordance with a chosen empiric description of natural convection in enclosed space. The outcome enables further quantitative investigations of the indirect cooling concept for hybrid PTLs. Preliminary results predict a sufficient thermal coupling between the HTS cable and stagnant helium.

Pipe failures in dense phase transfer lines were detected in a Polyethylene (PE) granule process plan due to excessive vibration. A dynamic time–history analysis and a fatigue evaluation were performed to identify the root cause and mitigate vibration, in addition to the existing static stress analysis study. The piping system is designed for slug flow, in which moving solid/liquid material which is driven by gas pockets generates various transient forces at elbows. Time–History Inputs (TIH) and Time–History Location (THL) files were, as a result, constructed from the vendor slug forces, elbow geometry, and inter–elbow distances. Unlike the static profiles, time–history analysis here applies to force–time data directly and then evaluates the response incrementally through each event. Further analysis showed that these static methods tend to overpredict the stresses combined with dynamic time–history analysis, while the fatigue evaluation confirms a safe mode of operation over the overall expected life cycle. Time–history dynamics is essential for any realistic stress and fatigue predictions in slug-loaded transfer lines and avoiding unnecessary overdesign. This study provides opportunities to investigate more details for condition monitoring maintainability gaps, as well as to resolve the problem.

Abstract Optics tuning in transfer lines and LINACs can be challenging due to the fact that multiple combinations of machine settings can lead to the same diagnostic output. Moreover, the lack of a periodic solution can limit the ability to infer optics in the same way as rings from BPM signals. Model based approaches are often used to assist with the optics tuning in combination with optimization or parameter estimation. Here we have developed a novel approach using machine learning inverse models trained on a known configuration to detect variations in quadrupole settings without explicitly including them in the model. This paper shows a comparison of neural network models and linear models on both a simulation based study and experimental studies conducted at the AGS to RHIC transfer line at Brookhaven National Lab.

Influence of the transfer segment between thermal desorber and gas chromatograph applied to essential oil samples.

Spherical Halbach arrays, when uniformly magnetized outward, enable large‐scale magnetic structures: orbital halos, vacuum conduits for charged streams and vehicles, defensive barriers, and long‐distance energy transfer lines. To synthesize system architectures, kinematic and field‐pressure calculations, control strategies, and material estimates into a comprehensive design framework. Prototyping and scaling pathways are outlined for applications from nano‐robot lunar hops to crewed launch pipelines. Also, to explore the theoretical framework and propulsion dynamics of negatively charged nano-scale spherical Halbach arrays transiting long-range distances under engineered magnetic and electric field environments. Through combined Lorentz and energy conservation principles, to evaluate the feasibility of transferring a nano-Halbach from Earth to orbit, the Moon, Mars, and beyond. Analytical models incorporate gravitational and relativistic effects, while optimizations emphasize phased field pulse systems. Results show that purely magnetic propulsion exceeds relativistic thresholds, whereas phased electric acceleration schemes yield feasible velocities, with Moon transfer achievable in ~6 minutes and Mars in ~58 days. Additionally, to present a hybrid electromagnetic propulsion framework that combines nested spherical Halbach arrays with rotating photonic fields—specifically light, laser, and X-ray beams. This system explores the dynamic behavior of negatively charged nano-scale Halbach spheres under layered electromagnetic environments. Analytical models and field richness equations are developed to simulate particle motion, confinement, and acceleration. The fusion of coherent light, structured laser beams, and high-frequency X-rays introduces novel mechanisms for torque, trapping, and quantum-scale modulation. Applications range from nano-propulsion and particle confinement to photonic reactors and quantum field control.

This work describes examples of the use of cryogenic lines and their designs, referring in detail to typical structural nodes found in cryogenic transfer lines. As a special case, multichannel cryogenic transfer lines are described, in which the process pipes are made of Invar. This has a significant impact on the number of internal supports and the method of thermal shrinkage compensation, which directly impact into reduced heat input during the transfer of cryogenic media. The second law of thermodynamics and the Gouy-Stodola theorem are discussed from the perspective of their application in optimizing and evaluating heat and mass transfer devices. The next part of the work presents the internal structure of the selected 250 m multichannel cryogenic transfer line. Several variants of the method of supporting process pipes have been presented and compared with the solution using Invar. For each solution, an entropy analysis was carried out in order to select the best design in terms of the entropy generated in the process pipes. From the examples presented, it is proven that entropy minimization method can be used for complex optimization of entire cryogenic distribution systems, as well as their indi-vidual components.

The Polish Free-Electron Laser (PolFEL), which is currently under construction in the National Centre for Nuclear Research in Świerk near Warsaw, will comprise an electron gun and from four to six cryomodules, each accommodating two nine-cell TESLA RF superconducting resonant cavities. To cool the superconducting resonant cavities, the cryomodules will be supplied with superfluid helium at a temperature of 2 K. Other requirements regarding the cooling power of PolFEL result from the need to cool the power couplers for the accelerating cryomodules (5 K) and thermal shields, which limit the heat inleaks due to radiation (40–80 K). The machine will utilize several thermodynamic states of helium, including two-phase superfluid helium, supercritical helium, and low-pressure helium vapours. Supercritical helium will be supplied from a cryoplant by a cryogenic distribution system (CDS)—transfer line and valve boxes—where it will be thermodynamically transformed into a superfluid state. This article presents the architecture of the CDS, discusses several design solutions that could have been decided on with the use of second law analysis, and presents the design methodology of the chosen CDS elements.

Traditional supervisory control methods for the nonblocking control of discrete event systems often suffer from exponential computational complexity. Reinforcement learning-based approaches mitigate state explosion by sampling many random sequences instead of computing the synchronous product of multiple modular supervisors, but they struggle with limited reachable state spaces. A primary novelty of this study is to use the K-means clustering method for online inference with the learned state-action values. The clustering method divides all events at a state into the good group and the bad group. The events in the good group are allowed by the supervisor. The obtained supervisor policy can ensure both system constraints and larger control freedom compared to conventional RL-based supervisors. The proposed framework is validated by two case studies: an industrial transfer line (TL) system and an automated guided vehicle (AGV) system. In the TL case study, nonblocking reachable states increase from 56 to 72, while in the AGV case study, a substantial expansion from 481 to 3558 states is observed. Our new method achieves a balance between computational efficiency and nonblocking supervisory control.

The existing study is concerned with isolating unknown impurities from the bulk drug of Empagliflozin. The bulk drug Empagliflozin, Column: Agilent Technologies DB-FFAP 30mx 0.530mm, 1.0-micron, Instrument: PerkinElmer, GC 2014, for GC-MS Column: Agilent Technologies, Elite 5-MS, 30mm X 0.25 mm, 1.0-micron Instrument: Perkin Elmer, Carrier gas: Helium Source Temp.: 230°C, Transfer line: 250°C Inlet Temp.: 180°C, Diluent: Methanol Source energy: 70eV IR and 1HNMR. Column: DB-624,30m x 0.53mm x 3.0 um or equivalent oven Temperature. The injector and detector temperatures were 200°C and 240°C. For a 0.2 ml injection volume and 0.1-minute injection period, the (LOD) Limit of detection and (LOQ) Quantitation were 25 ppm and 76 ppm, respectively. In the Empagliflozin samples, the % recovery for acetic acid varied from 94.10 to 96.31. The devised technique was verified by specificity, linearity, accuracy, quantitation limit, precision, accuracy, and robustness by the principles set out by the International Council on Harmonisation. The IR shows that the Acetic acid impurity was unknown and confirmed. by GC-MS and NMR spectra. An unknown impurity was identified during bulk drug analysis. It was isolated and characterized using various analytical techniques, such as IR, NMR, GC, and GC-MS. Acetic acid, a genotoxic residual solvent, was identified as an unknown impurity and needs to be quantified and validated for routine analytical work. Residual solvents are undesirable compounds (solvents) produced or employed during the production of pharmaceutical formulations, excipients, or drugs, that don't seem to be eliminated by reasonable means in the final product. Method validation was carried out using GC-Column due to better separation in GC-HS mode. The validated method was proven specific, accurate, precise, and sensitive. The advanced and validated process can be implemented to determine and quantify Acetic acid in Empagliflozin bulk drug.