bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation on bond in post‐installed anchored bars and lap splices subjected to direct tension
Authors: Croppi José I. , Genesio Giovacchino , Piccinin Roberto , Casucci Daniele , Ahrens Mark Alexander , Mark Peter
Published: April 2023

Moment‐resisting monolithic connections between new and pre‐existing structural members are frequently used whenever existing reinforced‐concrete structures must be extended and/or strengthened. Overlapping post‐installed and cast‐in‐place bars is a common solution to provide reinforcement continuity. Nowadays, post‐installed bars with high‐performance mortars can reach higher bond strength than cast‐in‐place bars configurations. While higher performance could lead to shorter embedment lengths, uncertainties and constraints from design standards limit the potential for cost‐effective solutions. In this work, an experimental investigation on post‐installed lap splices is presented with some novelties in terms of test setup and specimen layout. The bond of a high‐performance injection mortar used in all specimens was assessed by means of tension tests. Lap length, concrete strength, and confinement by transverse reinforcement are the variable factors in the study of the load–slip behavior of the bars and the splitting resistance of the specimens. Results are in good accordance with the design formulas available in standards and empirical data published in the literature.
Pharmaceutical Applications of Ionic Liquids: A Personal Account
Authors: Md Moshikur Rahman , Goto Masahiro
Published: April 2023

Ionic liquids (ILs) have been extensively used in drug formulation and delivery as designer solvents and other components because of their inherent tunability and useful physicochemical and biopharmaceutical properties. ILs can be used to manage some of the operational and functional challenges of drug delivery, including drug solubility, permeability, formulation instability, and in vivo systemic toxicity, that are associated with conventional organic solvents/agents. Furthermore, ILs have been recognized as potential solvents to address the polymorphism, limited solubility, poor permeability, instability, and low bioavailability of crystalline drugs. In this account, we discuss the technological progress and strategies toward designing biocompatible ILs and explore potential biomedical applications, namely the solubilization of small and macromolecular drugs, the creation of active pharmaceutical ingredients, and the delivery of pharmaceuticals.
Using complete blood count‐derived inflammatory markers to compare postoperative inflammation in dogs undergoing open or laparoscopic ovariectomy
Authors: Espadas‐González Lorena , Usón‐Casaús Jesús M. , Pastor‐Sirvent Nieves , Santella Massimo , Ezquerra‐Calvo Javier , Pérez‐Merino Eva M.
Published: April 2023

Background

The inflammatory response triggered in dogs after laparoscopic ovariectomy (LapOV) or ovariectomy through mini‐celiotomy (COV) has never been compared using the neutrophil‐to‐lymphocyte ratio (NLR), platelet‐to‐lymphocyte ratio (PLR) and systemic inflammatory index (SII).

Methods

Bitches underwent LapOV (n = 25) or COV (n = 25). NLR, PLR and SII were calculated 1 hour before ovariectomy (T0) and 2−3, 6−8 and 20−24 hours (T1−T3) after surgery.

Results

Surgical time was longer in the LapOV group. Changes over time were observed in the NLR, PLR and SII in both groups (p <0.001). PLR at baseline and T1 (p = 0.03 and 0.01) and NLR, PLR and SII at T2 (p = 0.01, 0.01 and 0.009) were higher in the LapOV group than in the COV group, but they did not differ at T3.

Limitations

The overrepresentation of Greyhounds in the LapOV group and the short‐term follow‐up are the study's main limitations.

Conclusion

Although an inflammatory peak was observed 6−8 hours after COV or LapOV, it was higher after the laparoscopy. However, there was no difference in the bitches' inflammatory status 24 hours after surgery.
Analysing wind power ramp events and improving very short‐term wind power predictions by including wind speed observations
Authors: Lochmann Moritz , Kalesse‐Los Heike , Schäfer Michael , Heinrich Ingrid , Leinweber Ronny
Published: April 2023

Though wind power predictions have been consistently improved in the last decade, persistent reasons for remaining uncertainties are sudden large changes in wind speed, so‐called ramps. Here, we analyse the occurrence of ramp events in a wind farm in Eastern Germany and the performance of a wind power prediction tool in forecasting these events for forecasting horizons of 15 and 30 min. Results on the seasonality of ramp events and their diurnal cycle are presented for multiple ramp definition thresholds. Ramps were found to be most frequent in March and April and least frequent in November and December. For the analysis, the wind power prediction tool is fed by different wind velocity forecast products, for example, numerical weather prediction (NWP) model and measurement data. It is shown that including observational wind speed data for very short‐term wind power forecasts improves the performance of the power prediction tool compared to the NWP reference, both in terms of ramp detection and in decreasing the mean absolute error between predicted and generated wind power. This improvement is enhanced during ramp events, highlighting the importance of wind observations for very short‐term wind power prediction.
Application of infrared spectroscopy and its theoretical simulation to arsenic adsorption processes
Authors: Ablat Hadiya , Nurmamat Xamsiya , Ma Xiaoyan , Xie Qingqing , Zhao Zhixi
Published: April 2023

Accurate detection and analysis of arsenic pollutants are an important means to enhance the ability to manage arsenic pollution. Infrared (IR) spectroscopy technology has the advantages of fast analysis speed, high resolution, and high sensitivity and can be monitored by real‐time in situ analysis. This paper reviews the application of IR spectroscopy in the qualitative and quantitative analysis of inorganic and organic arsenic acid adsorbed by major minerals such as ferrihydrite (FH), hematite, goethite, and titanium dioxide. The IR spectroscopy technique cannot only identify different arsenic contaminants but also obtain the content and adsorption rate of arsenic contaminants in the solid phase. The reaction equilibrium constants and the degree of reaction conversion can be determined by constructing adsorption isotherms or combining them with modeling techniques. Theoretical calculations of IR spectra of mineral adsorbed arsenic pollutant systems based on density functional theory (DFT) and analysis and comparison of the measured and theoretically calculated characteristic peaks of IR spectra can reveal the microscopic mechanism and surface chemical morphology of the arsenic adsorption process. This paper systematically summarizes the qualitative and quantitative studies and theoretical calculations of IR spectroscopy in inorganic and organic arsenic pollutant adsorption systems, which provides new insights for accurate detection and analysis of arsenic pollutants and arsenic pollution control.

Practitioner Points

This paper reviews the application of infrared spectroscopy in the qualitative and quantitative analyses of inorganic and organic arsenic acid adsorbed by major minerals such as ferrihydrite, hematite, goethite, and titanium dioxide, which can help identify and evaluate the type and concentration of arsenic pollutants in water bodies.

In this paper, theoretical calculations of infrared spectra of mineral adsorbed arsenic pollutant systems based on density functional theory reveal the adsorption mechanism of arsenic pollutants in water at the solid–liquid interface and help to develop targeted arsenic pollution control technologies.

This paper provides a new and reliable analytical detection technique for the study of arsenic contaminants in water bodies.
Polymer nanomaterials for use as adjuvant surgical tools
Authors: Erdi Metecan , Sandler Anthony , Kofinas Peter
Published: April 2023

Materials employed in the treatment of conditions encountered in surgical and clinical practice frequently face barriers in translation to application. Shortcomings can be generalized through their reduced mechanical stability, difficulty in handling, and inability to conform or adhere to complex tissue surfaces. To overcome an amalgam of challenges, research has sought the utilization of polymer‐derived nanomaterials deposited in various fashions and formulations to improve the application and outcomes of surgical and clinical interventions. Clinically prevalent applications include topical wound dressings, tissue adhesives, surgical sealants, hemostats, and adhesion barriers, all of which have displayed the potential to act as superior alternatives to current materials used in surgical procedures. In this review, emphasis will be placed not only on applications, but also on various design strategies employed in fabrication. This review is designed to provide a broad and thought‐provoking understanding of nanomaterials as adjuvant tools for the assisted treatment of pathologies prevalent in surgery.

This article is categorized under:

Implantable Materials and Surgical Technologies > Nanomaterials and Implants

Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery
Research on the Public Participation of Nuclear Safety Based on Social Psychology
Authors: Li Guanghui , Bai Gang , Li Xiaoding , Qu Yunhuan , Gong Yu
Published: April 2023

Nuclear safety concerns the development of the cause of putting nuclear energy and technology to good use, environmental safety, and the public interest. The public participation of nuclear safety is an important means of popularizing safety knowledge and eliminating public concerns. Social psychology is a branch of psychology that studies the social phenomena of individuals and groups. In fact, the public participation of nuclear safety is a collective activity for citizens to integrate into nuclear safety and participate in nuclear safety. The theoretical root of public participation is social psychology. Using social psychology to analyze the behavior and ideas of various stakeholders in public participation can effectively enhance the relevance and effectiveness of public participation. Therefore, it is very important to carry out public safety research based on social psychology. This paper investigates the present situation of public participation of nuclear safety, and analyze the misunderstandings of current public participation based on social psychology: Public participation requires a high level of knowledge because more knowledgeable people are more supportive of nuclear energy; The public must either support or oppose nuclear energy, without a third option; Public opposition to nuclear energy is attributed to insufficient public participation; Wrong views should be downplayed and will disappear over time; Public participation is only the responsibility of dedicated staff. For these misunderstandings, this paper proposes a follow-up to the recommendations of public participation: Understand the conformity among individuals; Apply various measures to engage people from different groups to improve the effectiveness of public participation; Encourage extensive participation to create synergy; Step up international cooperation to promote public participation.
Economic Analysis of the One Through Fuel Cycle Based on Equilibrium Mass Flow
Authors: Li Zhiyong , Hu Jiang , Rong Mei , Shang Xin , Zhang Yifan
Published: April 2023

In order to evaluate the cost of each stage of the one through fuel cycle (OTC), the uranium required for each stage of the OTC is calculated in detail based on the equilibrium mass flow. According to the material flow analysis, front-end cost and back-end cost of the nuclear fuel cycle under different discount rates are analyzed according to the material flow. The results show that the front-end cost increases with the discount rate, while the back-end cost decreases with the discount rate, and the front-end cost is higher than the back-end cost. The three stages of natural uranium, uranium enrichment and fuel manufacturing not only account for a large proportion of the total cost, but also have a strong sensitivity. Among them, the cost of uranium enrichment has the greatest impact on LCOE, followed by the cost of natural uranium.
Calculation and Analysis of Polonium-210 Source Term in Primary Coolant System of Lead-Bismuth Fast Reactor
Authors: Wan Haixia
Published: April 2023

After the lead-bismuth coolant flows through the core area of the lead-bismuth fast reactor and is irradiated by neutrons, the radionuclide Polonium-210 will be produced. Polonium-210 has a half-life of 138 days and releases alpha particles during decay. With certain volatility, Polonium-210 will pose a potential threat to the environment. Therefore, Polonium-210 is one of the key contents of radiation environmental impact assessment of lead-bismuth reactor. The calculation model of Polonium-210 is established according to the metabolic mechanism of Polonium-210 in the coolant. According to the Polonium-210 calculation model, the generation, decay and migration laws of Polonium-210 in the whole life were analyzed, and the influence of extraction rate on the saturation of Polonium-210 was calculated. The results show that, taking a 20MWth lead-bismuth reactor as an example, in the case of no extraction, Polonium-210 reaches saturation in the fifth year of reactor operation, with a saturation activity of 3.15E + 15Bq. With an extraction efficiency of 90%, Polonium-210 will reach saturation on the 60th day after the reactor starts operating, with a saturation activity of 3.83E + 10Bq. The calculation results can provide a reference for the research on the distribution of Polonium-210 in the coolant.
Effects of Eluting Volumes to Isolation Efficiencies in Manual Synthesis of Ga-68 Labelled FAPI-04
Authors: Jiang Fei , Xing Naiguo , Lv Taiyong , Sun Zhanliang , Zhao Yan
Published: April 2023

Among different FAPIs (fibroblast activation protein inhibitors) developed for PET imaging, 68Ga-FAPI-04 has demonstrated the most impressive properties with low nanomolar affinity to FAP, near-complete internalization of radioactivity bound to FAP, and rapid blood clearance. The application of 68Ga-FAPI-04 has been extended to 28 different kinds of clinical cancer detection. The manual synthesis of 68Ga-FAPI-04 is like other 68Ga-labeling peptides, such as PSMA-11 and DOTATATE. However, because the radiochemical conversion (RCC) is about 90%, it is required to conduct a purification and isolation process to meet the required standard for clinical application. The purpose of this work is to characterize the increase of isolation efficiency (IE) by increasing the volume of eluting liquid applied to C18 columns and sterile filters. We designed an experiment and measured the residual activity distribution on both C18 columns and sterile filters for different eluting volumes. We characterized the change of activity residuals and isolation efficiencies with different eluting volumes in the process of purification and isolation. As a result, it was found that there were more activity leftovers on sterile filters than on C18 columns. By increasing the eluting volume from 6 mL to 12 mL, we measured the average IE being improved from 62.4% to 87.4%, which is greatly beneficial to clinical applications. In addition, the fluctuation of IE which might come from the different radiolabeling operators or materials used in the experiment, was also obviously decreased from 11.3% to 4.5%. This method has been proven to be efficient in the production of 68Ga-FAPI-04.
A Multi-state Degradation Model for Reliability Assessment of Multi-component Nuclear Safety Systems Considering Degradation Dependency and Random Shocks
Authors: Liang Qingzhu , Peng Changhong , Zhang Hang , Lu Jianchao
Published: April 2023

The degradation (e.g., wear, stress corrosion cracking, and fatigue) of nuclear safety systems is an inherently irreversible process, which will lead to system failure when the accumulated damage reaches a threshold level, resulting in catastrophic consequences. Therefore, it is essential to understand and model the degradation behavior of nuclear safety systems to predict and prevent potential failures and thus effectively avoid subsequent losses. This paper proposes a multi-state degradation model for multi-component nuclear safety systems, considering the dependency among the degradation processes and the effect of random shocks. The degradation processes of the system were modeled by the Semi-Markov process. The arrival of random shocks obeys a Poisson process. The transfer kernel function of the holistic model was derived, based on which the Monte Carlo algorithm for estimation of the system reliability was developed. Based on a simple case, the correctness of the proposed model is verified. The model is applied to the reliability analysis of one sub-system of the residual heat removal system of a nuclear power plant.
Multi-Physics Coupling Model for Thermal Hydraulics and Solute Transport in CRUD Deposits
Authors: Liu Yan , Liu Xiaojing , Du Sijia , Wang Jiageng , He Hui
Published: April 2023

The porous Chalk River Unidentified Deposit (CRUD) depositions on the fuel cladding have a great impact on the heat transfer and power distribution of the reactor, resulting in a decrease in reactor safety and economy. In current paper, a multi-physics model is developed to simulate thermal hydraulics and boron hideout within the CRUD depositions. Processes including heat transfer, pressure drop, capillary flow, solute transport, chemical reactions and radiolysis reactions are fully coupled. The coolant flows through the capillary tubes in the porous medium and evaporates into steam at the surface of chimneys. The solute diffuses into the porous medium by capillary flow and maintains its chemical equilibrium. Chemistry and thermal hydraulics are coupled by saturation temperature that varies with solute concentrations. The new model can reasonably predict the distributions of temperature, pressure, Darcy velocity and chemical concentrations. This model shows the effect of evaporation at the chimney surface on CRUD temperature and boric acid concentration. In addition, the results show that boron hideout is caused by the accumulation of boric acid and the precipitation of Li2B4O7 at the bottom of CRUD. The influence of morphology parameters such as porosity, thickness, and chimney geometry on heat transfer and solute transport within CRUD depositions is also evaluated.
Study on Composition Design of Enamel Coating and Its Resistance to Active Metal Vapor Corrosion
Authors: Jiang Y. F. , Li H. Y. , Chen J. , Shi X. Q. , Zhu Y. X.
Published: April 2023

After evaporation of cerium metal (simulated radioactive substance) in a stainless steel plate in a production process, Ce and Fe elements are interdiffused at the bonding interface and Ce-Fe solid solution is formed. There are problems such as incomplete recovery of attached materials and increased surface roughness at the interface, which cannot be reused. In order to reduce radioactive iste generation, metallic enamel coating is prepared on stainless steel substrate with SiO2, Al2O3, Na2O, K2O, CaF2 and CoO and its resistance to active metal vapor corrosion at high temperature is studied. The results show that the enamel coating is closely bonded to the substrate, forming a chemical bond of Fe-Co rich phase. The enamel coating can stably form a film with cerium metal atoms, and the evaporation coating does not fall off. The microstructure results show that cerium oxide is formed at the bonding interface between the enamel coating and cerium metal, forming a stable chemical bond. Compared with stainless steel substrate, there is no interfacial corrosion caused by mutual diffusion between enamel coating and cerium metal at the bonding interface, so it can only desorb cerium metal without damaging the coating and realize multiple reuse.
Study on the Effects from Spacer Wires on Coolant Flow Within a Fuel Assembly Used in the CiADS Core
Authors: Li Yunxiang , Meng Lu , Li Song , Liu Bo , Wang Disi , Zhang Youpeng , Zhang Lu , Jiang Wei
Published: April 2023

Spacer wires are frequently applied as the positioning components of fuel bundles in lead-based fast reactor fuel assemblies. It is extremely important to carry out the research of the impacts from spacer wires on coolant flow within fuel assemblies, and therefore the safety performances of reactor core. In this paper, the open source CFD calculation software OpenFOAM was adopted to perform the refined numerical simulation on the multi-pitch assembly model of 61 bundles and analyze the distribution of flow characteristics such as pressure, velocity, and temperature. The results show that: there is a pressure difference on both sides of the wires, which may cause the coolant to mix laterally; the mixing effect incurred by the wires may cause the uneven distribution of coolant velocity. There are obvious high-speed and low-speed zones, and the high-speed zone is located at the same position as the low-pressure zone. Due to the high flow rate in the peripheral sub-channel, the coolant temperature is lower. The maximum temperature difference at the outlet of the fuel assembly can reach 20K, which may cause local overheating and therefore cladding rupture under accidental conditions. The simulation can provide a reference for the correction of the calculation results of the 1D single-channel program and lay the foundation for the development of the subsequent two-phase flow model for fuel assemblies containing wire spacers.
Evaluation of Uncertainty for Determination of Trace Uranium in Biology by Laser Fluorescence Method
Authors: Wang Yajie , Wang Lufeng , Dong Chuanjiang , Li Li , Tang Mengqi , Sun Weizhong , Wu Yao
Published: April 2023

Large amounts of uranium-containing radioactive waste are generated in reactor operation and in the research and manufacture of nuclear fuel elements. At present, there are various uranium enrichment and separation methods such as reduction precipitation method, ion exchange method, solvent extraction method, membrane filtration method, adsorption method, and microorganism method to treat the uranium-containing radioactive waste generated in the related processes of nuclear facilities. However, the airborne effluent or liquid effluent discharged after treatment may still contain radioactive uranium. It is well known that uranium is a radioactive heavy metal element, and its radioactive and chemical toxicity cannot be ignored. Uranium in the environment enters the human body through the food route, and its long half-life can make the human body suffer from continuous radioactive internal radiation damage. As an environmental medium, organisms are closely related to the entry of uranium into the human body through food. Therefore, it is of great significance to carry out accurate measurement of uranium content in environmental-grade biological samples around nuclear facilities, however, complete and accurate measurement results include measurement data and uncertainty. Laser fluorescence method is a method for rapid analysis of uranium content in environmental samples. It has the advantages of high sensitivity, simple sample pretreatment, and wide measurement range, which has been widely used in nuclear industry, environmental monitoring and scientific research. At present, there is a lack of relevant reports on the uncertainty of the measurement of total uranium content in environmental-grade biological samples by laser fluorescence method. It is of great significance to accurately measure the uranium content in biological samples by evaluating the uncertainty of this method. In this paper, the WGJ-III trace uranium analyzer was used to analyze the uncertainty source of total uranium in environmental-grade biological samples by laser fluorescence method. The uncertainty measurement model was established, the uncertainty components were quantified, and the expanded uncertainty of the measurement of total uranium content in environmental biological samples was calculated. The evaluation results showed that the expanded uncertainty of a 0.05 g environmental biological sample is 10.8% (k = 2) without dilution, and the dominant uncertainty component is derived from the measurement uncertainty of sample fluorescence counting.
Research on ΔI Control Strategy During Rapid Power Reduction
Authors: Meng Desheng , Duan Rong , Li Zhijun
Published: April 2023

Cold source for the cooling system is provided by CRF pump in nuclear power plant. During failure of CRF pump, a rapid core power reduction to a lower power level is needed, which poses a challenge to ΔI control of the core. Based on the requirements of operating technical specifications, the influence of various factors concerned the ΔI control strategy such as cycle burn-up, low power level and power reduction methods is researched for the rapid power reduction process in a certain balance cycle. Meanwhile, sensitivity analysis is carried out on the action of the control banks for different phases during the rapid power reduction process. Based on the analysis of the main influencing factors, proposal on the rapid power reduction strategy related to the reduced power level, power reduction method and different characteristic burn-up is put forward. The match of the cooling capacity of the CRF pump and the reduced core power is realized, thus ensure the safety and economy performance of reactor core.
Heterogeneous Reactivity Effect Analysis of Pu Spots Considering Grain Size Distribution Based on MOC
Authors: Ohara Masato , Ogawa Akifumi , Kitada Takanori , Takeda Satoshi
Published: April 2023

In the process of Mixed Oxide (MOX) fuel fabrication, plutonium grains, called plutonium spots (Pu spots), occur in MOX fuel because uranium and plutonium cannot be mixed completely. The previous study showed that the prediction accuracy of criticality is improved by considering the heterogeneity of Pu spots in MOX fuel in the analysis of some critical experiments. The analysis of the heterogeneity has been performed by Monte Carlo calculations, to ensure that core geometry and self-shielding effects are accurately considered in nuclear calculations. However, the results of Monte Carlo calculations are obtained with the statistical errors, thus the small reactivity worth is difficult to be analyzed. Therefore, in the previous study, the heterogeneous model by using a method devised by R. Sanchez was introduced into OpenMOC that is deterministic calculation code. Although there are numerous sizes of Pu spots in MOX fuel, an only single size of the grain could be considered in the modified OpenMOC. Therefore, in this study, the modified OpenMOC code was additionally modified to consider the grain size distribution of Pu spots.

The calculation result obtained by the additionally modified OpenMOC shows that the heterogeneous reactivity effect caused by numerous grain sizes of Pu spots is evaluated at −0.190%Δk/kk’ at highly enriched fuels. On the other hand, a heterogeneous reactivity effect by single grain size is evaluated at −0.225%Δk/kk’. The additionally modified OpenMOC makes it possible to study the effect of considering the grain size distribution of Pu spots in MOX fuel.
Study of Stress Analysis Method for Floating Nuclear Power Plant Containment Under Combined Multiple Loads
Authors: Li Jiyue , Wang Donghui , Zhang Meng , Liu Hongbing , Qu Xianqiang
Published: April 2023

Floating nuclear power plants (FNPP) are a combination of small nuclear reactors and hull structures. The applicable design codes and simulation analysis methods of floating nuclear power plants are nearly seldom, especially for the ultimate strength of containment considering multi loads. In order to analyze the structural strength of the steel containment of a floating nuclear power plant under the combined action of multiple loads, the structural response is analyzed in ANSYS considering the external hull loads and internal containment loads such as wave loads, wind loads, current loads, hull impact loads, internal pressure and temperature of the containment. The structural response result from wind, wave, current, internal pressure and temperature loads are calculated, separately, to obtain the stress field of the containment. Finally, the stress fields of the containment generated by each load are superimposed to obtain the stress distribution characteristics of the containment, and then strength assessment and stress analysis are performed.
Numerical Simulation of Flow Boiling Heat Transfer in Helical Tubes Under Marine Conditions
Authors: Yuan Leqi , Cheng Kun , Bian Haozhi , Liao Yaping , Jiang Chenxi
Published: April 2023

Lead-based cooled reactors in most countries and some small reactors at sea use helical tube steam generators. Compared with U-tubes, the convection heat transfer coefficient in the spiral tube is higher, the structure is more compact, and the secondary flow is generated under the action of centrifugal force and gravity, which can achieve the effect of wetting the inner wall of the tube. However, due to the importance of the steam generator in the reactor and the complexity of the flow and boiling in the helical tube, the aggregation behavior of bubbles, the distribution of the two-phase interface and the secondary flow in the tube will significantly affect the heat transfer characteristics, so the gas-liquid phase in the tube is studied. Distribution, changes in heat transfer coefficients, and fluid flow characteristics are very important.

In order to study the boiling heat transfer characteristics of helical once-through steam generators under static and marine conditions to provide safe and reliable energy supply for offshore facilities such as marine floating, this study uses STAR-CCM+ software, VOF method and Rohsenow boiling model to study the heat transfer capacity and flow characteristics of flow boiling in a helical tube under swaying and tilting conditions. The gas-liquid phase distribution characteristics, secondary flow variation characteristics and convective heat transfer coefficient of the fluid under different swing functions and inclined positions are obtained by numerical calculation, and the law of physical parameters changing with the cycle is found. The research results show that the secondary flow and heat transfer capacity in the tube change with the cycle, and the change is most obvious at the tube length of 0.8m. 5% of the normal condition; when the inclination angle is 45°, the maximum increase of the convection heat transfer coefficient is 16.8%, and the maximum decrease is 6.6%.
Analytical Method Research of Source Term for Steam Generator Tube Rupture Accident of Small Modular Reactor
Authors: Xia Ming-ming , Wang Jun-long , Zhu Jian-ping , Tian Chao , Liu Jia-jia
Published: April 2023

Based on the full reference to the existing engineering practice and safety review experience, and considering the actual design characteristics of the small modular reactor ACP100, a set of source term analysis method suitable for ACP100 of the steam generator tube rupture (SGTR) accident is proposed, and the source term analysis and consequence evaluation of ACP100 SGTR accident was carried out using this method. The analysis shows that the radiological consequences of the accident source term calculated by this method meet the acceptance criteria of small modular reactor. The analysis results of this article can provide support for the follow-up review of accident source term of ACP100.
Electroweak-flavour and quark-lepton unification: a family non-universal path
Authors: Davighi Joe , Isidori Gino , Pesut Marko
Published: April 2023

Abstract

We present a family-non-universal extension of the Standard Model where the first two families feature both quark-lepton and electroweak-flavour unification, via the SU(4) Sp(4)L Sp(4)R gauge group, whereas quark-lepton unification for the third family is realised à la Pati-Salam. Via staggered symmetry breaking steps, this construction offers a natural explanation for the observed hierarchical pattern of fermion masses and mixings, while providing a natural suppression for flavour-changing processes involving the first two generations. The last-but-one step in the symmetry-breaking chain is a non-universal 4321 model, characterised by a vector leptoquark naturally coupled mainly to the third generation. The stability of the Higgs sector points to a 4321 → SM symmetry-breaking scale around the TeV, with interesting phenomenological consequences in B physics and collider processes that differ from those of other known 4321 completions.
Discrete bulk reconstruction
Authors: Aaronson Scott , Pollack Jason
Published: April 2023

Abstract

According to the AdS/CFT correspondence, the geometries of certain spacetimes are fully determined by quantum states that live on their boundaries — indeed, by the von Neumann entropies of portions of those boundary states. This work investigates to what extent the geometries can be reconstructed from the entropies in polynomial time. Bouland, Fefferman, and Vazirani (2019) argued that the AdS/CFT map can be exponentially complex if one wants to reconstruct regions such as the interiors of black holes. Our main result provides a sort of converse: we show that, in the special case of a single 1D boundary divided into N “atomic regions”, if the input data consists of a list of entropies of contiguous boundary regions, and if the entropies satisfy a single inequality called Strong Subadditivity, then we can construct a graph model for the bulk in linear time. Moreover, the bulk graph is planar, it has O(N2) vertices (the information-theoretic minimum), and it’s “universal”, with only the edge weights depending on the specific entropies in question. From a combinatorial perspective, our problem boils down to an “inverse” of the famous min-cut problem: rather than being given a graph and asked to find a min-cut, here we’re given the values of min-cuts separating various sets of vertices, and need to find a weighted undirected graph consistent with those values. Our solution to this problem relies on the notion of a “bulkless” graph, which might be of independent interest for AdS/CFT. We also make initial progress on the case of multiple 1D boundaries — where the boundaries could be connected via wormholes — including an upper bound of O(N4) vertices whenever an embeddable bulk graph exists (thus putting the problem into the complexity class NP).
Integrable models based on non-semi-simple groups and plane wave target spacetimes
Authors: Sfetsos Konstantinos , Siampos Konstantinos
Published: April 2023

Abstract

We initiate the construction of integrable λ-deformed WZW models based on non-semisimple groups. We focus on the four-dimensional case whose underlying symmetries are based on the non-semisimple group $$ {E}_2^c $$

E
2
c

. The corresponding gravitational backgrounds of Lorentzian signature are plane waves which can be obtained as Penrose limits of the λ-deformed SU(2) background times a timelike coordinate for appropriate choices of the λ-matrix. We construct two such deformations which we demonstrate to be integrable. They both deform the Nappi-Witten plane wave and are inequivalent. Nevertheless, they have the same underlying symmetry algebra which is a Saletan-type contraction of that for the λ-deformed SU(2) background with a timelike direction. We also construct a plane wave from the Penrose limit of the λ-deformation of the $$ \frac{\textrm{SU}(2)}{\textrm{U}(1)} $$

SU

2

U

1

coset CFT times a timelike coordinate which represents the deformation of a logarithmic CFT constructed in the past. Finally, we briefly consider contractions based on the simplest Yang-baxter σ-models.
Extensions of two-field mimetic gravity
Authors: Zheng Yunlong , Rao Haomin
Published: April 2023

Abstract

Two-field mimetic gravity was recently realized by looking at the singular limit of the conformal transformation between the auxiliary metric and the physical metric with two scalar fields involved. In this paper, we reanalyze the singular conformal limit and find a more general solution for the conformal factor A, which greatly broadens the form of two-field mimetic constraint and thus extends the two-field mimetic gravity. We find the general setup still mimics the role of dark matter at the cosmological background level. Moreover, we extend the action by introducing extra possible term for phenomenological interests. Surprisingly, some special cases are found to be equivalent to general relativity, k-essence theory and Galileon theory. Finally, we further extend the theory by allowing the expression of mimetic constraint to be arbitrary without imposed condition, and show that the dark matter-like behavior is unaffected even in this extension.
Actively transcribed rDNA and distal junction (DJ) sequence are involved in association of NORs with nucleoli
Authors: Liskovykh Mikhail , Petrov Nikolai S. , Noskov Vladimir N. , Masumoto Hiroshi , Earnshaw William C. , Schlessinger David , Shabalina Svetlana A. , Larionov Vladimir , Kouprina Natalay
Published: April 2023

Although they are organelles without a limiting membrane, nucleoli have an exclusive structure, built upon the rDNA-rich acrocentric short arms of five human chromosomes (nucleolar organizer regions or NORs). This has raised the question: what are the structural features of a chromosome required for its inclusion in a nucleolus? Previous work has suggested that sequences adjacent to the tandemly repeated rDNA repeat units (DJ, distal junction sequence) may be involved, and we have extended such studies by addressing several issues related to the requirements for the association of NORs with nucleoli. We exploited both a set of somatic cell hybrids containing individual human acrocentric chromosomes and a set of Human Artificial Chromosomes (HACs) carrying different parts of a NOR, including an rDNA unit or DJ or PJ (proximal junction) sequence. Association of NORs with nucleoli was increased when constituent rDNA was transcribed and may be also affected by the status of heterochromatin blocks formed next to the rDNA arrays. Furthermore, our data suggest that a relatively small size DJ region, highly conserved in evolution, is also involved, along with the rDNA repeats, in the localization of p-arms of acrocentric chromosomes in nucleoli. Thus, we infer a cooperative action of rDNA sequence—stimulated by its activity—and sequences distal to rDNA contributing to incorporation into nucleoli. Analysis of NOR sequences also identified LncRNA_038958 in the DJ, a candidate transcript with the region of the suggested promoter that is located close to the DJ/rDNA boundary and contains CTCF binding sites. This LncRNA may affect RNA Polymerase I and/or nucleolar activity. Our findings provide the basis for future studies to determine which RNAs and proteins interact critically with NOR sequences to organize the higher-order structure of nucleoli and their function in normal cells and pathological states.
Über ein Jahr B-Zell-gerichtete Therapie mit Ofatumumab s.c.: erste Ergebnisse einer prospektiven, patientenzentrierten Real-world-Beobachtungsstudie
Authors: Klimas Rafael , Karl Anna-Sophia , Poser Philip Lennart , Sgodzai Melissa , Theile-Ochel Simon , Gisevius Barbara , Faissner Simon , Nastos Ilias , Gold Ralf , Motte Jeremias
Published: April 2023

Einleitung

Ofatumumab (Kesimpta™) ist ein s.c. anwendbarer Anti-CD20-Antikörper, welcher seit 2021 in Deutschland für die Behandlung der schubförmigen Multiplen Sklerose (RMS) eingesetzt wird. Die Selbstanwendung bietet ein hohes Maß an Unabhängigkeit von intravenösen Applikationsformen bei stark wirksamer Immuntherapie. In dieser Studie erfassten wir die patientenzentrierte Erfahrung bei 99 von 127 Patienten, die durch uns auf das Medikament eingestellt wurden. Ziel war die Untersuchung der Verträglichkeit und Akzeptanz aus Patientensicht.

Methoden

Die Datensammlung erfolgte mittels Arztdokumentationen, Fragebögen und Telefoninterviews.

Ergebnisse

Die Kohorte besteht aus 127 Patienten. Die Patienten erhielten 2,8 (± SD 1,7) Vortherapien. Die mittlere Therapiedauer mit Ofatumumab betrug 9,8 Monate (± SD 3,5). Strukturiert erfasst wurden 99 Patienten. 23 % der Patienten gaben an, während der Erstapplikation des Medikaments keine Nebenwirkungen gehabt zu haben. 19 % bewerteten die Nebenwirkungen als „sehr mild“ und 18 % als „mild“. Hierbei traten Schüttelfrost/Fieber (48 %), Kopf- (46 %) und Gliederschmerzen (45 %), sowie andere Symptome (19 %) auf. Bei Folgeinjektionen gaben 72 % der Patienten keine Nebenwirkungen an. 87 % der Patienten empfanden die Handhabung des Medikaments als „sehr einfach“. Es kam zu einem Schubereignis während der Therapie mit Ofatumumab.

Diskussion

Unsere Studie zeigt, dass Ofatumumab von den Patienten gut akzeptiert und vertragen wird. Im Beobachtungszeitraum ist es zu einem Schubereignis gekommen. Die Nebenwirkungen sind mild und treten vor allem während der Erstanwendung auf. Es konnte keine erhöhte Infektneigung beobachtet werden. Die Daten legen nahe, dass Ofatumumab auch in der Real-world-Anwendung eine wirksame und sichere Therapieoption für Patienten mit einer schubförmig remittierenden multiplen Sklerose ist.
Metal budget and origin of aqueous brines depositing deep-seated Zn-Pb mineralization linked to hydrocarbon reservoirs, North German Basin
Authors: Sośnicka Marta , Lüders Volker , Duschl Florian , Kraemer Dennis , Laurent Oscar , Niedermann Samuel , Banks David A. , Wilke Franziska , Wohlgemuth-Ueberwasser Cora , Wiedenbeck Michael
Published: April 2023

The origin, evolution, and interplay of brine and hydrocarbon fluid systems play a crucial role in the formation of deep sediment-hosted base metal ore deposits. Here we investigate ratios of halogens, noble gases, stable C and S isotopes, and metal budgets of aqueous brines, which deposited deep-seated and near-surface hydrothermal Zn-Pb mineralization hosted by Zechstein carbonates in the Lower Saxony Basin (North German Basin), by studies of fluid inclusions in sphalerite and quartz. Major and trace element geochemistry and noble gas isotopic signatures of brine inclusions revealed that the ore-forming fluids were highly reactive and experienced prolonged interactions with host rocks in the constricted, over-pressured metal source regions and consequently evolved from near-neutral, oxidized brines towards more reduced, acidic high-salinity brines. Quartz-hosted halite-saturated fluid inclusions with Th <200°C contain Zn and Pb concentrations up to ca. 9400 μg g-1 and 5200 μg g-1, respectively, and indicate the efficiency of metal scavenging processes. The interactions with Westphalian coals and Corg-rich shales influenced the redox state as well as the trace and critical element budget of the sphalerite-hosted fluid inclusions, with enrichment in Ge, Pd, Sb, Tl, Bi, and Ag. The salinities of metalliferous fluids originated primarily from seawater evaporation, however in addition a significant halite-dissolution component is present in the southern part of the Lower Saxony Basin. High concentrations of radiogenic noble gases and potassium in the sphalerite-hosted fluid inclusions are ascribed to strong interactions with the Paleozoic siliciclastic sedimentary pile and crystalline basement rocks. Reflux of the strongly modified, sulfur-poor, Zn-Pb-bearing acidic brines, proceeded via re-activated structurally controlled pathways into sour gas or gas-saturated brine pools in the Zechstein Ca2 carbonate unit. Here, mixing of the ascending metal-rich brines with H2S derived from thermochemical sulfate reduction (TSR), resulted in the deposition of deep-seated Zn-Pb ores in the Lower Saxony Basin. The overall timing of the Zn-Pb ore formation can be constrained to the Upper Cretaceous basin inversion.
An effective validation of analytical method for determination of a polar complexing agent: the illustrative case of cytotoxic bleomycin
Authors: Plesnik Helena , Bosnjak Masa , Cemazar Maja , Sersa Gregor , Kosjek Tina
Published: April 2023

The effectiveness of highly polar agents in cancer treatment is well recognized, but their physicochemical properties make their analytical determination a demanding task. Their analysis requires peculiar sample preparation and chromatographic separation, which heavily impacts the precision of such an analytical method. As a case study, we chose a polar cytotoxic bleomycin, which is a mixture of complexing congeners with relatively high molecular mass, a fact that creates an added challenge in regard to its detection via electrospray mass spectrometry. These issues combined lead to a deprived method performance, so the aim of this study is manifold, i.e., to optimize, validate, and establish quality performance measures for determination of bleomycin in pharmaceutical and biological specimens. Quantification of bleomycin is done at diametrically different concentration levels: at the concentrations relevant for analysis of pharmaceutical dosage forms it is based on a direct reversed-phase HPLC-UV detection, involving minimum sample pretreatment. On the contrary, analysis of bleomycin in biological specimens requires phospholipid removal and protein precipitation followed by HILIC chromatography with MS/MS detection of bleomycin A2 and B2 copper complexes being the predominant species. This study further attempts to solve the traceability issue in the absence of certified reference standards, determines measurement uncertainty, investigates BLM stability and method performance characteristics, and, last but not least, provides an explanatory example of how a method quality assurance procedure should be established in case of an exceedingly complex analytical method.

Graphical abstract
Fake Science – zwielichtige Wissenschaft
Authors: Lenz Hans-J.
Published: April 2023

Im Folgenden wird die erschreckende Breite von Fake Science vor Augen geführt. Da ist zum einen die von Wirtschaft und Industrie finanzierte, zweckgebundene Auftragsforschung, deren Forschungsziel es einzig ist, nicht Hypothesen zu bestätigen oder zu beweisen, sondern Verwirrung unter der Bevölkerung beim Kausalzusammenhang von gesellschaftlichen Phänomenen zu stiften. Der Zusammenhang von Rauchen und Lungenkrebs fällt hier runter. Zum anderen wird die Aufrichtigkeit des gesamten Wissenschaftsbetriebs ausgehebelt, indem Pseudoverlage und -tagungen (vermeintlichen) Wissenschaftlern die Möglichkeit bieten, Manuskripte ungeprüft zu veröffentlichen oder Vorträge zu halten, deren Inhalt fragwürdig oder sogar Unsinn ist. Wie immer beim Datenbetrug bilden Profit oder Prestige den Antriebsmotor.
Synthesis of novel antibacterial grafted sodium alginate copolymer-based adsorbent for wastewater treatment
Authors: Darwesh Hebatallah , Mohamed Riham R. , Soliman Soliman M. A.
Published: April 2023

Grafting of styrene (S) onto biopolymer Sodium Alginate (NaAlg) via free-radical polymerization forming (NaAlg-g-PS), using potassium persulfate K2S2O8 (KPS) as initiator. Fourier-transform infrared spectroscopy (FT-IR) and Proton nuclear magnetic resonance (1H-NMR) characterized the formed grafted copolymer and scanning electron microscope (SEM) to show changes in the surface morphology of sodium alginate, which occurred due to the grafting process. The effect of various grafting parameters on Sodium Alginate as; Styrene and KPS concentration, the grafting temperature, and grafting time is studied. The adsorption of the grafted copolymer to both cationic dye (Malachite Green) and anionic dye (Congo Red) was investigated. In addition to the effect of the adsorption of the grafted copolymer for toxic heavy metals such as Cu2+, Cr6+, Ni2+, and Co2+. The order of the metal adsorption by grafted copolymer is Cr6+ > Cu2+ > Co2+ > Ni2+. The biological activity of the grafted copolymer was shown toward Neisseria gonorrhoeae (Gram-negative), and Bacillus subtilis (Gram-positive) using the agar diffusion method. The obtained results showed excellent improvement in the antibacterial activity of the alginate against Bacillus subtilis and Neisseria gonorrhoeae by the grafting process.

Graphical abstract