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Reliability Assessment of NPP Safety Class Equipment Considering the Manufacturing Quality Assurance Process
No full textQuality and safety are intensely related and go hand in hand. Quality of the safety-grade equipment is very important for the safety of a nuclear power plant (NPP) and achieving production goals. During manufacturing of plant components or equipment, deviation from the design might occur at different stages of manufacturing for various reasons, such as a lack of skilled manpower, deviation of materials, human errors, malfunction of equipment, violation of manufacturing procedure, etc. These deviations can be assessed cautiously and taken into consideration in the final safety analysis report (FSAR) before issuing an operating license. In this paper, we propose a Bayesian belief network for quality assessment of safety class equipment of NPPs with a few examples. The proposed procedure is a holistic approach for estimation of equipment failure probability considering manufacturing deviations and errors. Case studies for safety-class dry transformers and reactor pressurizers employing the proposed method are also presented in this article. This study provides insights for probabilistic safety assessment engineers and nuclear plant regulators for improved assessment of NPP safety
Disparate roles for C. elegans DNA translocase paralogs RAD-54.L and RAD-54.B in meiotic prophase germ cells
No full textRAD54 family DNA translocases partner with RAD51 recombinases to ensure stable genome inheritance, exhibiting biochemical activities both in promoting recombinase removal and in stabilizing recombinase association with DNA. Understanding how such disparate activities of RAD54 paralogs align with their biological roles is an ongoing challenge. Here we investigate the in vivo functions of Caenorhabditis elegans RAD54 paralogs RAD-54.L and RAD-54.B during meiotic prophase, revealing distinct contributions to the dynamics of RAD-51 association with DNA and to the progression of meiotic double-strand break repair (DSBR). While RAD-54.L is essential for RAD-51 removal from meiotic DSBR sites to enable recombination progression, RAD-54.B is largely dispensable for meiotic DSBR. However, RAD-54.B is required to prevent hyperaccumulation of RAD-51 on unbroken DNA during the meiotic sub-stage when DSBs and early recombination intermediates form. Moreover, DSB-independent hyperaccumulation of RAD-51 foci in the absence of RAD-54.B is RAD-54.L-dependent, revealing a hidden activity of RAD-54.L in promoting promiscuous RAD-51 association that is antagonized by RAD-54.B. We propose a model wherein a division of labor among RAD-54 paralogs allows germ cells to ramp up their capacity for efficient homologous recombination that is crucial to successful meiosis while counteracting potentially deleterious effects of unproductive RAD-51 association with unbroken DNA
Multi-Abnormality Attention Diagnosis Model Using One-vs-Rest Classifier in a Nuclear Power Plant
No full textMulti-abnormal events, referring to the simultaneous occurrence of multiple single abnormal events in a nuclear power plant, have not been subject to consideration because multi-abnormal events are extremely unlikely to occur and indeed have not yet occurred. Such events, though, would be more challenging to diagnose than general single abnormal events, exacerbating the human error issue. This study introduces an efficient abnormality diagnosis model that covers multi-abnormality diagnosis using a one-vs-rest classifier and compares it with other artificial intelligence models. The multi-abnormality attention diagnosis model deals with multi-label classification problems, for which two methods are proposed. First, a method to effectively cluster single and multi-abnormal events is introduced based on the predicted probability distribution of each abnormal event. Second, a one-vs-rest classifier with high accuracy is employed as an efficient way to obtain knowledge on which particular multi-abnormal events are the most difficult to diagnose and therefore require the most attention to improve the multi-label classification performance in terms of data usage. The developed multi-abnormality attention diagnosis model can reduce human errors of operators due to excessive information and limited time when unexpected multi-abnormal events occur by providing diagnosis results as part of an operator support system
Operating System Support-Based Prevention Mechanism for Use-After-Free Attacks on the Glibc Memory Allocator
No full textUse-After-Free??? ?????? ??????????????? ???????????? ????????? ?????? ????????? ?????? ????????? ?????? ?????? ???????????? ???????????? ??????. ?????? ????????? ??? ????????? ??? ????????? ?????? ?????? ???????????? ?????? ????????? ??? ?????? ????????? ???????????? ???????????? ?????? ????????? ?????????????????? ?????? ?????????, ?????? ????????? MarkUs??? ??? ????????? ?????? ?????????????????? ??????????????? ?????? ??????????????? ????????? ??? ????????? ????????????. ????????? ??? ????????? ???????????? ?????? ?????? ????????? ?????? ??????????????? Use-After-Free ????????? ?????? ????????? ?????? ????????? MarKern??? ????????????. MarKern??? MarkUs??? ?????? ?????? Mark-and-Sweep ????????? ????????? ??????????????? ???????????? ???????????? ??????????????? ?????? ?????? ?????? ????????? ?????? ????????????. ?????? ?????? ????????? ?????? glibc(GNU C Library) Allocator??? ???????????? ???????????????. ?????? ??????, SPEC CPU 2017?????? glibc malloc?????? ???????????? ?????????????????? ?????? ?????? ?????? ??????(?????? ??????) ?????? 18.50%??? ??????????????? ????????? ????????? ??? ?????????
Preference of Selfie Images Captured by Front Camera - By Comparing Samsung Galaxy S22 Ultra and Apple iPhone 13 Pro Max
No full textThe use of the front camera, or the ???selfie camera??? is increasing among the young generation. The act of taking self-photos is not only to capture the moment, but also to enhance ones??? self-esteem and even as a way of self-branding. The current camera manufacturers are aiming for high specification and high performance of the camera. However, accurate color reproduction of the camera may not correlate with high satisfaction of the users. This study focuses on the selfie camera of the two representative smartphone brands, Samsung Galaxy S22 Ultra and Apple iPhone 13 Pro Max. The study asked the participants to take selfies under four different lighting environments with three colored backgrounds using the two smartphones. Participants evaluated preference scores for each portrait on the two smartphones in the range of 7, where 1 is the least preferred and 7 for the most preferred. The results for the preference of the selfie camera showed that the average preference score was higher for Samsung Galaxy S22 Ultra than Apple iPhone 13 Pro Max by 0.44. The preference for the two displays were very similar with difference of only 0.01. For the background color, light pink and light yellow was preferred for Samsung Galaxy S22 Ultra but dark blue was preferred for Apple iPhone 13 Pro Max. Relatively dark environment with low color temperature was referred for both smartphones. The interview revealed that the users preferred Samsung Galaxy S22 Ultra for the skin color and less detailed expression for the skin texture. Users who preferred Apple iPhone 13 Pro Max liked the captured atmosphere of the photo, especially at low luminance low color temperature environment. This study places the significance on understanding how the users evaluate the photos taken by the selfie camera
Merging biomass and CO2 utilization; process design and assessment on simultaneous production of lactic acid and formic acid from glycerol and CO2
No full textBiomass and CO2 conversion is receiving great attention to address climate change and energy crisis. Bio-based lactic acid (LA) appeals industries, however, current technologies suffer from low productivity and waste pro-duction. The transfer hydrogenation of glycerol and CO2 to LA and formic acid (FA) has been proposed as an alternative pathway, but further development and process design are required. This study proposes the inte-grated process for conversion of glycerol and CO2 to LA and FA derivatives. A two-pot/two-step transfer hy-drogenation was demonstrated to achieve high products yield, catalyst reusability, and product separation. The esterification of lactate and formate salts to corresponding esters utilizing CO2 was also developed, which re-duces H2SO4 consumption and K2SO4 waste. Techno-economic and life cycle assessments reveal that CO2 uti-lization is crucial for high economic benefit and low climate change impact. This study shows integrating biomass and CO2 could have synergies to design greener process
Developing Protein-based injectable hydrogels using PCNA and SpyCatcher for controlled cargo load and release
No full textThree-dimensionally crosslinked hydrogels have been widely developed for various biomedical applications such as scaffolds, drug delivery, and biomaterial implants. However, many hydrogels use chemical crosslinkers that limit their applications due to their potential toxicity and non-biodegradabiliy. To overcome these limitations, protein-based hydrogels have emerged as promising alternatives. Herein, we designed two different non-fibrous recombinant protein building blocks; a core trimeric proliferating cell nuclear antigen (PCNA) and a bridging SpyCatcher protein (SC) dimer. We genetically introduced SpyTag peptide (ST) to the (PCNA) to form ST-PCNA to serve as the core building blocks, and fused two SCs to form SC-SC as the connecting building blocks. Simple mixing of these two building block proteins (ST-PCNA and SC-SC) spontaneously led to the PCNA-based 3D networks, facilitating rapid gelation and resulting in stable protein-based hydrogel formations both in vitro and in vivo. The newly formed protein-based hydrogels possessed a 3D porous network structure that allows for control of cargo loading and release, making them well-suited for use as sustained release systems. To take advantage of the attractive properties of protein-based hydrogels, we evaluated injectability of hydrogels and the controlled loading and sustained release of various cargos, including fluorescent dyes, therapeutic drugs, and proteins, both in vitro and in vivo. These non-fibrous protein building block-based hydrogels may offer new opportunities to develop biocompatible and versatile platforms for sustained cargo delivery, scaffold formation, and implantable biomaterials
INVESTIGATIONS ON INTERACTIVE FAILURE MODES OF A LAMINATED COMPOSITE USING SYNCHROTRON RADIATION CT AND FEA
No full textHigh D2/H2 selectivity performance in MOF-303 under ambient pressure for potential industrial applications
No full textThe commercial demand for D2 is poised to increase significantly; however, the low natural abundance and the energy- and capital-intensive industrial separation (i.e., 24 K cryogenic distillation) will hamper future scientific and industrial growth in isotopologue separation. Alternatively, kinetic quantum sieving (KQS)-based adsorptive D2 separation has been proposed recently, but the separation performance is reported mostly at near zero pressure or in the sub-few ten mbar range. Herein, an Al-based Metal-Organic Framework, MOF-303, with 1-D narrow-micro pores is studied for D2/H2 adsorptive separation at ambient pressure. Cryogenic thermal desorption spectroscopic analysis of MOF-303 confirmed that the synergetic effect of binding affinity & enhanced KQS (owing to molecular rearrangement of D2 adsorbed phase at high pressure induced by strong D2 confinement), along with D2 partial condensation, leads to a significant increase in the D2 uptake with increasing exposure pressure up to 1,000 mbar. Consequently, a remarkable selectivity of 21.6 at 25 K has been achieved even at an operating pressure of 1000 mbar, which is an industry-friendly condition. The observed D2/H2 separation selectivity is about ten times higher than that of the industrial cryogenic method (best selectivity of below 2.5 at 24 K), and comparable to the performance of the adsorbent materials already reported with low operating pressure, making adsorptive D2/H2 separation through MOF-303 an alternative for cryogenic industrial isotopologue separation
Temperature-directed fluorescent switchable nanoparticles based on P3OT-PNIPAM nanogel composite
No full textPoly(N-isopropylacrylamide) (PNIPAM) is a unique stimuli-responsive material that exhibits a lower critical solution temperature (LCST). Owing to this characteristic temperature-dependent behavior, PNIPAM has found extensive utilization as an active material in various applications, including sensors, drug delivery, and cellular imaging. Herein, we demonstrate temperature-directed fluorescent switchable nanoparticles based on poly(3octylthiophene-2,5-diyl) (P3OT) nanoaggregate-embedded PNIPAM nanogel composites (POPNs) featuring different crosslinker contents. The amount of P3OT loading in the nanogel composites can be gradually controlled by varying the crosslinking density of the PNIPAM matrix; this may be attributable to the efficient entrapment of P3OT nanoaggregates in case of a dense polymeric network with the increase in crosslinking density. POPNs exhibit dramatic temperature-dependent fluorescence enhancement (by a factor of 2.11). This is based on the environmental changes affecting fluorescent P3OT chains at temperatures below and above the LCST of the PNIPAM matrix. Based on this temperature-directed fluorescent switching capability, POPN could find potential applications in various fields, including biomedical imaging and sensors