Tight Size Research Articles

Antibacterial Effect of Silver Nanoparticles against Oral Biofilms in Subjects with Motor and Intellectual Disabilities.

Motor and intellectual disabilities (MIDs) represent a great challenge for maintaining general health due to physical and cognitive limitations, particularly in the maintenance and preservation of oral health. Silver nanoparticles (AgNPs) have emerged as a promising therapeutic tool for bacterial control, including oral biofilms; however, knowledge of the bactericidal effectiveness of oral biofilms from patients with MIDs is insufficient. This study aims to determine the antimicrobial effect of AgNPs on different oral biofilms taken from patients with and without MIDs. Two sizes of AgNPs were prepared and characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Through consecutive sampling, biofilm samples were collected from 17 subjects with MIDs and 20 subjects without disorders. The antimicrobial effect was determined by obtaining the minimum inhibitory concentration (MIC) of AgNPs, and the identification and distribution of oral bacterial species were determined by polymerase chain reaction (PCR). Finally, correlations between sociodemographic characteristics and the antimicrobial levels of AgNPs were also explored. The values of the MIC results were analyzed with IBM-SPSS software (version25) using non-parametric tests for independent groups and correlations, with statistical significance being considered as p < 0.05. Both sizes of AgNPs exhibited tight particle size distributions (smaller: 10.2 ± 0.7 nm; larger: 29.3 ± 2.3 nm) with zeta potential values (-35.0 ± 3.3 and -52.6 ± 8.5 mV, respectively) confirming the stability that resulted in little to no agglomeration of nanoparticles. Although both sizes of AgNPs had good antimicrobial activity in all oral biofilms, the smallest particles had the best antimicrobial effects on the oral biofilm samples from patients with and without MIDs, even better than chlorhexidine (CHX) (p < 0.05). Likewise, the patients with disabilities showed higher levels of antimicrobial sensitivity to AgNPs compared with CHX (p < 0.05). Although the microorganisms included in the biofilms of females had a statistically higher growth level, the AgNP antimicrobial effect was statistically similar in both genders (p > 0.05). The most frequent bacteria for all oral biofilms were S. mutans (100%), P. intermedia (91.6%), T. forsythia (75.0%), T. denticola (75.0%), P. gingivalis (66.6%), F. nucleatum (66.6%), S. sobrinus (50.0%), and A. actinomycetemcomitans (8.3%). AgNPs exhibited considerable antimicrobial potential to be used as a complementary and alternative tool in maintaining and preserving oral health in patients with MIDs.

Widened Attention‐Enhanced Atrous Convolutional Network for Efficient Embedded Vision Applications under Resource Constraints

Onboard image analysis enables real‐time autonomous capabilities for unmanned platforms including aerial, ground, and aquatic drones. Performing classification on embedded systems, rather than transmitting data, allows rapid perception and decision‐making critical for time‐sensitive applications such as search and rescue, hazardous environment exploration, and military operations. To fully capitalize on these systems’ potential, specialized deep learning solutions are needed that balance accuracy and computational efficiency for time‐sensitive inference. This article introduces the widened attention‐enhanced atrous convolution‐based efficient network (WACEfNet), a new convolutional neural network designed specifically for real‐time visual classification challenges using resource‐constrained embedded devices. WACEfNet builds on EfficientNet and integrates innovative width‐wise feature processing, atrous convolutions, and attention modules to improve representational power without excessive overhead. Extensive benchmarking confirms state‐of‐the‐art performance from WACEfNet for aerial imaging applications while remaining suitable for embedded deployment. The improvements in accuracy and speed demonstrate the potential of customized deep learning advancements to unlock new capabilities for unmanned aerial vehicles and related embedded systems with tight size, weight, and power constraints. This research offers an optimized framework, combining widened residual learning and attention mechanisms, to meet the unique demands of high‐fidelity real‐time analytics across a variety of embedded perception paradigms.

Preparation of hydrophobic PTFE/ceramic membranes featuring a tight and uniform pore size distribution through the solid-state sintering of PTFE nanoparticles

The surface wettability and pore structure of membranes play crucial roles in determining their separation efficiency. Innovating ceramic membranes with hydrophobic surfaces holds considerable promise for broadening their applications. Owing to the remarkable hydrophobic properties and robustness of PTFE materials, this study suggests the fabrication of PTFE/ceramic composite membranes utilizing a solid-state sintering of PTFE nanoparticles. Polyvinyl alcohol (PVA) was employed as a binding agent to facilitate the formation of a uniform PTFE membrane layer on the porous ceramic substrate. A comprehensive investigation was conducted into the influence of various factors, including PVA addition, emulsion concentration, dip-coating duration, and sintering temperature, on the morphology and performance of these composite membranes. The results showed that the incorporation of PVA effectively mitigated the back-diffusion of PTFE particles and ensured the structural integrity of membrane. The resulting PTFE/ceramic membrane exhibited a finer and more uniform pore structure than the commercial PTFE membrane. The composite membrane boasted a water contact angle of 133°, an average pore size of 78 nm, and a membrane layer thickness of 3.8 μm. These characteristics contributed to its exceptional separation performance when utilized in the ultrafiltration of polystyrene nanoparticle suspensions and the androstenedione-contained water-in-oil emulsion.

Memory-Efficient and Flexible Detection of Heavy Hitters in High-Speed Networks

Heavy-hitter detection is a fundamental task in network traffic measurement and security. Existing work faces the dilemma of suffering dynamic and imbalanced traffic characteristics or lowering the detection efficiency and flexibility. In this paper, we propose a flexible sketch called SwitchSketch that embraces dynamic and skewed traffic for efficient and accurate heavy-hitter detection. The key idea of SwitchSketch is allowing the sketch to dynamically switch among different modes and take full use of each bit of the memory. We present an encoding-based switching scheme together with a flexible bucket structure to jointly achieve this goal by using a combination of design features, including variable-length cells, shrunk counters, embedded metadata, and switchable modes. We further implement SwitchSketch on the NetFPGA-1G-CML board. Experimental results based on real Internet traces show that SwitchSketch achieves a high Fβ-Score of threshold-t detection (consistently higher than 0.938) and over 99% precision rate of top-k detection under a tight memory size (e.g., 100KB). Besides, it outperforms the state-of-the-art by reducing the ARE by 30.77%\sim99.96%. All related implementations are open-sourced.

Synthesis and Characterization of Carbon Microbeads.

We report a microfluidic-based droplet generation platform for synthesizing micron-sized porous carbon microspheres. The setup employs carbon materials such as graphite, carbon nanotubes, graphene, fullerenes, and carbon black as starting materials. Custom composition, structure, and function are achieved through combinations of carbon materials, cross-linkers, and additives along with variations in process parameters. Carbon materials can be assembled into spheres with a mean diameter of units to hundreds of μm with relatively tight size distribution (<25% RSD). Pore structure and size (tens to hundreds of angstrom) can be modulated by incorporating porogen/coporogen dilutants during synthesis. The microbeads have excellent mechanical stability with an elastic modulus of hundreds of MPa. They can sustain high dynamic fluid flow pressures of up to 9000 psi. This work lays the foundation for synthesizing novel tailorable and customizable carbon microbeads. It opens avenues for applying these novel materials for composite and additive manufacturing, energy, life science, and biomedical applications.

Investigation on the effect of the gas-to-metal ratio on powder properties and PBF-LB/M processability

Metal powders for the laser powder bed fusion process are usually produced via gas atomization. However, due to the tight particle size distribution required for this application, the yield of the atomization process is low, resulting in a high-powder cost. In this work, atomization process parameters were varied to increase the gas-to-metal ratio to reduce the particle size distribution produced, and therefore increase the yield of the process. As a result, eight powders were produced starting from scrap AISI 136L material at different gas-to-metal ratio values, and the atomization process yield was successfully increased by 50%. First, the eight powders were characterized in terms of powder size, shape distributions, and flowability. Later, all powders were used to produce tensile specimens. The powders produced at higher yield exhibited a larger number of fine particles but slightly lower circularity, particularly in the coarse fraction. Furthermore, powders produced at a high gas-to-metal ratio demonstrated enhanced flowing properties and higher packing density. Consequently, these powders exhibited superior tensile performance, with ultimate tensile strength (UTS) ranging from 651 to 673 MPa and elongation values between 63 and 66%.

Prediction of gas–water relative permeability in tight rock from movable fluid distribution with nuclear magnetic resonance

The measurement of the relative permeability in tight rock is challenging due to its ultralow permeability and the time-consuming nature of the experiments. Studying the movable and unmovable fluid distribution and establishing a reliable relative permeability prediction model is an urgent problem to be solved. This paper used nuclear magnetic resonance (NMR) to investigate movable and unmovable water distribution in tight sandstone under different centrifugal forces. A new method for predicting gas–water relative permeability in tight rock is established based on movable fluid distribution using the capillary bundle model. The results show that the distribution of movable and unmovable fluids is strongly influenced by the tight rock's pore size distribution and structure. The unmovable fluid saturation increases as the tight rock's permeability and median radius decrease. The nonlinear correlation between the NMR relaxation time and the pore throat size obtained from high-pressure mercury intrusion can be used to derive the pore size of the fluid distribution in tight rocks. The ratio of the movable fluid thickness to pore throat size increases near linearly with the logarithm of the pore throat size. The proposed mathematical model for the prediction of gas-water relative permeability based on movable fluid distribution is verified by comparing with the normalized relative permeability curve measured from experiments. This new model offers an alternative method of estimating the gas–water relative permeability when measurement is unavailable due to the ultralow permeability of the core samples.

Artificial Lift: Adapting to Change

_ Humans and oil are alike in that the inner will to move from a comfortable spot—be it a sofa or a shale pore—often requires the application of outer motivation. It could be the hunger pangs prompting a reach for a donut or the pesky roommate—natural gas—lifting the hefty crude bead on its way to the surface in response to a pressure differential. So, what is a human to do when the oil needs a little extra convincing to leave its sofa? Artificial lift has long provided the swift kick needed to get and keep oil moving in conventional resources. Its story in unconventional resources is one of countless hours spent in the field figuring out that what works in one basin may not necessarily work in another and that what works today to economically lift oil to the surface will change over the life of the well. In this first part of a two-part series, we look at how the artificial-lift sector has adapted to producing unconventional resources. The second part of the series to publish in November will crack open the lift toolbox to take a deeper look at the techniques and technologies under development or new to the market. Steep Learning Curve While the life cycle of conventional oil and gas development is well documented, the rush of unconventional wells that kicked off in 2009 brought with it a whole slew of new challenges, like highly tortuous wellbores and solids production, spurring a greater appreciation for the intricacies of field development. “There was a steep learning curve in the early stages of producing from unconventional reservoirs. As operators continue to develop these reservoirs and push the envelope by drilling longer laterals with more-complex deviation profiles, artificial lift must keep adapting,” said Thomas Anderson, vice president of rod-lift solutions and PCS Ferguson at Champion X. “What worked last week needs to be tweaked to perform even better to handle the challenges we’ll face next week. It’s a constant evolution and we’re continually working to evolve our fit-for-purpose technologies, processes, and services to meet tomorrow’s challenges.” The remarkable growth of the US shale industry over the past 13 years has been, in part, built on the foundation of conventional oil and gas techniques and technologies. “Existing lift methods have been redefined based on newer production challenges not present in traditional vertical wells. Well geometry, landing depth, tight casing size, longer lateral draining higher production rates, and increased oil/gas rate are just a few of the new challenges in unconventional wells,” said Humberto Machado, global product line director for artificial lift at Weatherford. “The lesson learned here is the integrated planning and the development of an artificial-lift strategy that allows scalability, rapid deployment, robust and simple to operate, minimal infrastructure, and ability to match decline curve. This requires significant trial-and-error efforts to develop best practices, and operational guidelines to enhance overall system reliability,” he added. This redefinition, along with a little adaptation, and a whole lot of experimentation has developed a new toolbox unique to its role in the production process.

Essence of the Enhanced Osmotic Energy Conversion in a Covalent Organic Framework Monolayer.

Low membrane conductivity originated from a high membrane thickness has long been the "Achilles heel" of the conventional polymeric membrane, greatly hampering the improvement of the output power density in osmotic power generation. Herein, we demonstrate a molecularly-thin two-dimensional (2D) covalent organic framework (COF) monolayer membrane, featured with ultimate thickness, high pore density, and tight pore size distribution, which performs as a highly efficient osmotic power generator. Despite the large pore size up to 3.8 nm and relatively low surface charge density of 2.2 mC m-2, the monolayer COF membrane exhibits a high osmotic current density of 16.7 kA m-2 and an output power density of 102 W m-2 under 50 times the NaCl salinity gradient (0.5 M/0.01 M). This superior power density could be further improved to 170 W m-2 in the real seawater/river water gradient system. When the large pore size and low surface charge density are considered, this superior performance is not expected. Computational studies further reveal that the ultimate membrane permeability originated from the high membrane porosity, rather than ion selectivity, plays a dominant role in the production of high current density, especially under high salinity. This work provides an alternative strategy to realize improved output power density in ultrapermeable membranes.

Abstract 2282: Efficient sample preparation with Covaris AFA® technology enhances confidence in Illumina® TruSight™Oncology 500 Assay

Abstract High throughput and robust DNA fragmentation is a critical step in Next Generation Sequencing (NGS) for clinical genomics, ultimately ensuring higher quality for the final sequencing data. The typical requirements in NGS workflow (nucleic acid fragmentation, library preparation, sequencing, etc) comprise scalability, efficiency, reliability, and robustness. Failures to achieve confidence in any of the steps can negatively impact sequence data, rendering them unusable for diagnosis. Covaris’ Adaptive Focused Acoustics® (AFA®) technology enables efficient DNA fragmentation regardless of DNA concentration and starting molecular weight, ensuring a tight fragment size distribution, minimal sample loss, and most importantly, desired reliability and reproducibility.Illumina®’s TruSight™ Oncology 500 (TSO 500) protocol describes an enrichment-based approach to convert DNA and RNA extracted from formalin-fixed paraffin embedded (FFPE) tissue samples into libraries enriched for cancer-related genes that can be sequenced on Illumina® sequencing systems. The TSO 500 assay is optimized to prepare libraries from genomic DNA (gDNA) that is sheared to optimized fragment sizes and offers high fidelity determination of DNA variants across 523 cancer relevant genes. The TSO 500 assay is the assay of choice across most cancer centers using a standardized pipeline and therefore is suitable for routine use in precision oncology as a comprehensive genomic profiling solution. This study focuses on demonstrating the optimized DNA fragmentation protocol for TSO 500 assay with parallel 8-sample processing with an ML230 Focused-ultrasonicator. Citation Format: Debadeep Bhattacharyya, Kasturi Pal, Eugenio Daviso, Ulrich Thomann. Efficient sample preparation with Covaris AFA® technology enhances confidence in Illumina® TruSight™Oncology 500 Assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2282.

Multi-layered nanofiber membranes: Preparation, characterization, and application in wastewater treatment

Over the last few decades, micropollutants have been found in the natural surface water, and their presence poses a series of risks to living organisms in the aquatic biotope. Nanofiber membranes have been shown as a new strategy for separating micron-size pollutants due to their tight pore size and high water permeability. Here, a high-efficient multi-layered nanofiber membrane with improved mechanical strength was prepared using the lamination technique. First, polyamide 6 (PA6), polyacrylonitrile (PAN), and polyvinylidene fluoride (PVDF) nanofibers webs were selected. Then nanofibers were laminated on support under various temperatures. Prepared membranes were characterized using SEM, contact angle, pore size, and air permeability tests. The significance of lamination condition on membrane structure was investigated experimentally and statically. The membranes were examined for the treatment of synthetic micropollutants. According to the results, PAN and PA6 nanofiber membranes exhibited high water permeability (over 3000 L/(m2hbar)) under low pressure, whereas PVDF membranes showed zero permeability. Besides, the prepared nanofiber membranes could separate micropollutants from water with up to 99.91% separation efficiency. Prepared nanofiber membranes hold great promise for practical applications in environmental remediation.

The dual GLP-1 and GLP-2 receptor agonist dapiglutide promotes barrier function in murine short bowel.

Short bowel syndrome can occur after extensive intestinal resection, causing intestinal insufficiency or intestinal failure, which requires long-term parenteral nutrition. Glucagon-like peptide-2 (GLP-2) pharmacotherapy is now clinically used to reduce the disease burden of intestinal failure. However, many patients still cannot be weaned off from parenteral nutrition completely. The novel dual GLP-1 and GLP-2 receptor agonist dapiglutide has previously been shown to be highly effective in a preclinical murine short bowel model. Here, we studied the effects of dapiglutide on intestinal epithelial barrier function. In the jejunum, dapiglutide increased claudin-7 expression and tightened the paracellular tight junction leak pathway. At the same time, dapiglutide promoted paracellular tight junction cation size selectivity in the jejunum. This was paralleled by extension of the cation selective tight junction proteins claudin-2 and claudin-10b and preserved claudin-15 expression and localization along the crypt-villus axis in the jejunum. In the colon, no barrier effects from dapiglutide were observed. In the colon, dapiglutide attenuated the short bowel-associated, compensatorily increased epithelial sodium channel activity, likely secondary, by improved volume status. Future studies are needed to address the intestinal adaptation of the colon.

Facile Synthesis of Highly Dispersed and Well-Alloyed Bimetallic Nanoparticles on Oxide Support.

Supported alloy catalysts play a pivotal role in many heterogeneous catalytic processes of socioeconomic and environmental importance. But the controlled synthesis of supported alloy nanoparticles with consistent composition and tight size distribution remains a challenging issue. Herein, a simple yet effective method for preparation of highly dispersed, homogeneously alloyed bimetallic nanoparticles on oxide supports is reported. This method is based on solid solution of metal cations in parent oxide and strong electrostatic adsorption of a secondary metal species onto the oxide surface. In the reductive annealing process, hydrogen spillover occurs from the surface metal with a higher reduction potential to the solute metal in solid solution, leading to metal exsolution and homogenous alloying of the metals on the oxide surface. The ceria-supported Ni-Pt alloy is chosen as a model catalyst and hydrazine monohydrate decomposition is chosen as a probe reaction to demonstrate this method, and particularly its advantages over the conventional impregnation and galvanic replacement methods. A systematic application of this method using different oxides and base-noble metal pairs further elucidates its applicability and generality.

Investigating Growth of Gold Nanorods by Simultaneous Small‐Angle X‐Ray and Neutron Scattering

Increased usage of gold nanorods (AuNRs) in various biosensing and medical applications requires tight size and morphology control. This is often achieved by tuning the aggregation behavior of the stabilizing ligand cetrimonium bromide (CTAB). Because the role of CTAB during AuNR growth is still a matter of debate, simultaneous small‐angle X‐ray and neutron scattering experiments (SAXS/SANS) and measurements are performed. The SAXS/SANS measurements have enabled an instantaneous correlation between the size of evolving AuNR and the nanostructure of guiding CTAB moieties. Upon modifying the aggregation behavior of CTAB micelles by adding hexanol or pentanol as inert additives in the precursor solution, a marked change in reaction kinetics is observed. Alcohol‐modified CTAB nanostructures have improved AuNR size uniformity compared to those prepared in alcohol‐free CTAB solutions, which are attributed to different growth modes. The change in reaction kinetics is linked to a changed stabilization mechanism of reactants and nascent AuNR facilitated by CTAB micelles.

Identification of Glass Powders and Sands from the Crushing of Glass Waste from the City of Lom&amp;#233; in Togo

The sustainability of a city depends on the effective and efficient management of its solid waste. Waste recycling channels mainly process glass bottles for direct reuse. Some of these sectors carry out the crushing and grinding of end-of-life glass waste for use in civil engineering without the identification in terms of building materials being clearly established. The present study therefore aims to determine the physical and chemical characteristics of glass powders and sands resulting from the crushing and grinding of glass waste from Grand Lomé in Togo in order to consider their granular potential. Samples of sand and glass powder from the crushing and grinding of white, brown and green glass were subjected to characterization tests in the laboratory followed by analysis of the granular parameters and their modeling by Weibull’s law. The results show that the powder and the glass sand contain a high proportion of silica (SiO2) ranging from 69.11% to 70.18% and a low proportion of alumina (Al2O3) (less than 0.07) and iron (Fe2O3) (lower to 1.09). These three materials have tight and male graded grain sizes (Cu Cc omogeneous (k dab Mf 2.1) make these materials probable aggregates for plaster and coating mortars. Nevertheless, an in-depth study will be made to determine a suitable formula.

Novel design of bandages using cotton pads, doped with chitosan, glycogen and ZnO nanoparticles, having enhanced antimicrobial and wounds healing effects

In this present work, a new design for antimicrobial wound bandages is presented. The wound dressings were prepared using cotton fibers reinforced with elastic compression straps and secured with a polyester fabric of tight mesh size. The cotton pads were doped with a wound healing biocomposite, composed of chitosan, glycogen, and ZnO nanoparticles (CG@ZnONPs) previously formulated through a green process. The size of ZnONPs in the prepared CG@ZnONPs was 30–80 nm. The cotton pads impregnated with the CG@ZnONPs nanocomposite were characterized using FTIR, SEM, EDX, TGA, and DTGA methods. Moreover, the prepared dressings were tested on a number of intentionally injured rats. In this experiment, the % contraction of the treated wounds was monitored and compared to that of a control group of wounded rats, to which only sterile gauzes were applied. The results showed a much faster and an almost complete healing of rats treated with the synthesized dressings and the results were further confirmed by histopathological examination. The dressings were also found to exert a significant antimicrobial activity against a number of pathogenic microorganisms, generally encountered in common wounds, and could therefore be recommended to be a novel biomedical application for a fast, successful, and flawless wounds healing process.

Additional Criteria for Playground Impact Attenuating Sand

Falls within children’s playgrounds result in long bone and serious injuries. To lower the likelihood and severity of injury, impact attenuating surfaces (IAS) are installed within the impact area (fall zone). There are three primary IAS materials used, namely: granulated rubber products, wood fibre products, and sand. There is a deficiency with existing IAS test methods in that they do not take account of sand degradation over time. When children use the playground, sand degradation can occur when sand produces fines and smaller particles with low sphericity and angular which fill the voids between the sand particles. These fines and smaller particles tend to bind the sand and lower its impact attenuating performance. This paper proposes an additional IAS test to eliminate sands that degrade above an established threshold rate after installation due to normal usage. IAS degradation properties of fifteen IAS sands were tested including sand particle shape, sand particle distribution, percentage fines and sand particle degradation. This accelerated ageing test method is applicable only to sands and not rubber or wood fibre IAS products. The best IAS sands were sourced from quarries located on rivers that had eroded volcanic outcrops. These sands were shown to degrade the least and had little to no fines, and their particle shape was rounded to well-rounded. The most reliable source for good quality IAS sands on these rivers was on specific bends. The sand mined at these locations consistently had a tight particle size distribution.

Kinetics guided synthesis and performance of monodisperse zeolite LTA microspheres

Monodisperse zeolite microspheres hold great potential for wide industrial applications, but the existing preparation methods could hardly afford a uniform particle size distribution. Herein, the authors, for the first time, achieved the synthesis of monodisperse zeolite microspheres possessing high sphericity and tight particle size distribution with coefficient of variation (CV) less than 5%. Unlike previous methods that produce macroporous zeolites, the current strategy featured as shape-preserving steam assisted crystallization (SAC) successfully transforms aluminum and sodium source impregnated mesoporous silica microspheres into monodisperse zeolite LTA microspheres with tunable particle size between 10 and 30 μm. Spatiotemporal control of crystallization kinetics with balanced silica dissolution and zeolite nucleation is found to be essential for authentically maintaining the monodisperse spherical morphology, with larger-sized silica leading to higher zeolite sphericity. The pore size of the initial silica affects the resulting zeolite crystallinity, viz., larger silica pore size leads to higher zeolite crystallinity. Evolution of the zeolite microspheres involves synchronized silica dissolution and LTA crystallization in trapped domains facilitated by the intermediate, homogenously dispersed gel matrix, allowing to inherit the parent silica morphology. The LTA zeolite microspheres exhibit extremely high crystallinity, mechanical strength, thermal stability, and excellent air separation performance.

Efficient multi‐key fully homomorphic encryption over prime cyclotomic rings with fewer relinearisations

Multi-key fully homomorphic encryption (MKFHE) allows computations on ciphertexts encrypted by different users, which can be applied to implement secure multi-party computing (MPC). The current NTRU-based MKFHE has the following two drawbacks: One is that the relinearisation process during homomorphic evaluation is so complicated that the corresponding computation time is costly. The other is that a class of subfield attacks are proposed and affects the security of NTRU schemes over power-of-2 cyclotomic rings for large moduli q, especially for the NTRU-based fully homomorphic encryption (FHE) schemes. In this work, an efficient MKFHE scheme is proposed over prime cyclotomic rings with fewer relinearisations, which seems a good choice because of its potential to resist a subfield attack. More specifically, the time of the relinearisation process is reduced by half in homomorphic evaluations by separating the homomorphic multiplication and the relinearisation process (implementing two homomorphic multiplication operations together before relinearisation), while in current NTRU-type MKFHE schemes, these two processes are usually performed together. The error bound of the basic function components is re-analysed over prime cyclotomic rings in the average case, which can be used in the error analysis of our scheme. We construct an efficient NTRU-based single-key FHE scheme and an efficient MKFHE scheme over prime cyclotomic rings through relinearisation and modulus-switching techniques. The MKFHE scheme proposed has the on-the-fly property and has a tight ciphertext size compared with the GSW-type and BGV-type MKFHE schemes. An experiment shows that the homomorphic evaluation of the optimised single-key FHE scheme proposed is 1.9 times faster than an efficient NTRU-type MKFHE DHS16 proposed at DCC 2016.

Extreme relativistic reflection in the active galaxy ESO 033-G002

ABSTRACTWe present the first high signal-to-noise broad-band X-ray spectrum of the radio-quiet type-2 Seyfert ESO 033-G002, combining data from XMM–Newton and NuSTAR. The nuclear X-ray spectrum is complex, showing evidence for both neutral and ionized absorption, as well as reflection from both the accretion disc and more distant material, but our broad-band coverage allows us to disentangle all of these different components. The total neutral column during this epoch is NH ∼ (5−6) × 1022 $\rm \, cm^{-2}$, consistent with the optical classification of ESO 033-G002 as a type-2 Seyfert but not so large as to prevent us from robustly determining the properties of the innermost accretion flow. The ionized absorption – dominated by lines from Fe xxv and Fe xxvi – reveals a moderately rapid outflow (vout ∼ 5400 $\rm \, km~s^{-1}$) which has a column comparable to the neutral absorption. We find the disc reflection from the innermost regions to be extreme, with a reflection fraction of Rfrac ∼ 5. This requires strong gravitational lightbending and, in turn, both an extremely compact corona (within ∼2 RG of the black hole) and a rapidly rotating black hole (a* &amp;gt; 0.96). Despite this tight size constraint, with a temperature of kTe = 40–70 keV the X-ray corona in ESO 033-G002 appears similar to other active galactic nucle in terms of its placement in the compactness–temperature plane, consistent with sitting close to the limit determined by runaway pair production. Finally, combining X-ray spectroscopy, timing, and updated optical spectroscopy, we also estimate the mass of the black hole to be log[MBH/M⊙] ∼ 7.0–7.5.