Segmented mandrel tests of as-received and hydrogenated WWER fuel cladding tubes

Kiraly, Marton,Horvath, Marta,Nagy, Richard,Ver, Nora,Hozer, Zoltan Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.9

The mechanical interaction between the fuel pellet and the cladding tube of a nuclear fuel rod is a very important for safety studies as this phenomenon could lead to fuel failure and release of radioactivity. To investigate the ductility of cladding tubes used in WWER type nuclear power plants, several mandrel tests were performed in the Centre for Energy Research (EK). This modified mandrel test was used to model the mechanical interaction between the fuel pellet and the cladding using a segmented tool. The tests were conducted at room temperature and at 300 ℃ with inactive as-received and hydrogenated cladding ring samples. The results show a gradual decrease in ductility as the hydrogen content increases, the ductile-brittle transition was seen above 1500 ppm hydrogen absorbed.

Evaluation of axial and tangential ultimate tensile strength of zirconium cladding tubes

Marton Kiraly,Daniel Mihaly Antok,Laszlone Horvath,Zoltan Hozer 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.3

Different methods of axial and tangential testing and various sample geometries were investigated, andnew test geometries were designed to determine the ultimate tensile strength of zirconium claddingtubes. The finite element method was used to model the tensile tests, and the results of the simulationswere evaluated. Axial and tangential tensile tests were performed on as-received and machined fuelcladding tube samples of both E110 and E110G Russian zirconium alloys at room temperature to comparetheir ultimate tensile strengths and the different sample preparation methods

Feasibility of the Far Lateral Suboccipital Approach to the Retroodontoid Region. How Much Bone Removal Is Truly Needed?

Gergely Boon,Kristof Kiraly,Tamas Ruttkay,Bernhard Hirt,Koller Heiko 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Objective: The posterolateral extradural suboccipital approach can be used to reach the anterior epidural space and the retro-odontoid regions. The extent of necessary bone removal of the atlas vertebra (C1) has not yet been defined. We studied the changes in the size of the horizontal and vertical surgical windows using stepwise bone removal of C1. A representative case is shown. Methods: The anatomical study was performed bilaterally on five Thiel-fixed human cadavers (mean age, 83.7 years). The surgical window (horizontal×vertical) required to access the retro-odontoid region via a posterolateral approach was measured for an intact C1 posterior arch, after a semicircular inferior partial resection of the C1 arch, after resection of the unilateral hemiarch of C1, and finally after drilling approximately 3 mm from the medial aspect of the lateral mass of C1. Results: The intact C1 resulted in a very narrow surgical window of 6.3 mm×9.7 mm (horizontal×vertical). The vertical window increased to a 13 mm after the semicircular inferior partial resection of the C1 arch and to 17.3 mm in the case of removal of the ipsilateral C1 posterior arch. The bone removal from the medial aspect of the C1 lateral mass resulted in a widening of the horizontal surgical window to 10.3 mm. The final size of the surgical window was 10.3 mm×17.3 mm. The patient with severe kyphoscoliosis of the craniocervical spine was successfully operated on using odontoid and C1–2 facet osteotomies. Conclusion: If only the anterior epidural space or the base of the odontoid needs to be reached, the semicircular inferior partial resection of the C1 arch allows for an adequate surgical window. The tip of the odontoid could only be reached if the ipsilateral posterior arch is resected.

Characteristics and Psychiatric Symptoms of Internet Gaming Disorder among Adults Using Self-Reported DSM-5 Criteria

NaRi Kim,SamuelSukHyun Hwang,JungSeok Choi,DaiJin Kim,Zsolt Demetrovics,Orsolya Kiraly,Katalin Nagygyorgy,Mark. D. Griffiths,SoYeon Hyun,HyunChul Youn,SamWook Choi 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.1

Objective-The Section III of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) proposed nine diagnostic criteria and five cut-point criteria for Internet Gaming Disorder (IGD). We aimed to examine the efficacy of such criteria. Methods-Adults (n=3041, men: 1824, women: 1217) who engaged in internet gaming within last 6 months completed a self-report online survey using the suggested wordings of the criteria in DSM-5. Major characteristics, gaming behavior, and psychiatric symptoms of IGD were analyzed using ANOVA, chi-square, and correlation analyses. Results-The sociodemographic variables were not statistically significant between the healthy controls and the risk group. Among the participants, 419 (13.8%) were identified and labeled as the IGD risk group. The IGD risk group scored significantly higher on all motivation subscales (p<0.001). The IGD risk group showed significantly higher scores than healthy controls in all nine psychiatric symptom dimensions, i.e., somatization, obsession-compulsion, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism (p<0.001). Conclusion-The IGD risk group showed differential psychopathological manifestations according to DSM-5 IGD diagnostic criteria. Further studies are needed to evaluate the reliability and validity of the specific criteria, especially for developing screening instruments.

A Method to Quantify Breast MRI for Predicting Tumor Invasion in Patients with Preoperative Biopsy- Proven Ductal Carcinoma in Situ (DCIS)

고명수,김성헌,강봉주,최병길,송병주,차은숙,Atilla Peter Kiraly,김인성 대한자기공명의과학회 2013 Investigative Magnetic Resonance Imaging Vol.17 No.2

Purpose : To determine the quantitative parameters of breast MRI that predict tumor invasion in biopsy-proven DCIS. Materials and Methods: From January 2009 to March 2010, 42 MRI examinations of 41 patients with biopsy-proven DCIS were included. The quantitative parameters, which include the initial percentage enhancement (E1), peak percentage enhancement (Epeak), time to peak enhancement (TTP), signal enhancement ratio (SER), arterial enhancement fraction (AEF), apparent diffusion coefficient (ADC) value, long diameter and the volume of the lesion, were calculated as parameters that might predict invasion. Univariate and multivariate analyses were used to identify the parameters associated with invasion. Results: Out of 42 lesions, 23 lesions were confirmed to be invasive ductal carcinoma (IDC) and 19 lesions were confirmed to be pure DCIS. Tumor size (p = 0.003; 6.5 ± 3.2 cm vs. 3.6 ± 2.6 cm, respectively) and SER (p =0.036; 1.1 ± 0.3 vs. 0.9 ± 0.3, respectively) showed statistically significant high in IDC. In contrast, E1,Epeak, TTP, ADC, AEF and volume of the lesion were not statistically significant. Tumor size and SER had statistically significant associations with invasion, with an odds ratio of 1.04 and 22.93, respectively. Conclusion: Of quantitative parameters analyzed, SER and the long diameter of the lesion could be specific parameter for predicting invasion in the biopsy-proven DCIS.

Transgenic Strategy to Improve Stress Resistance of Crop Plants

Horvath, Gabor V.,Oberschall, Attila,Deak, Maria,Sass, Laszlo,Vass, Imre,Barna, Balazs,Kiraly, Zoltan,Hideg, Eva,Feher, Attila The Korean Society of Plant Biotechnology 1999 Plant molecular biology and biotechnology research Vol.1 No.1

Rapid accumulation of reactive oxygen species (ROS) and their toxic reaction products with lipids and proteins significantly contributes to the damage of crop plants under biotic and abiotic stresses. We have identified several stress activated alfalfa genes, including the gene of the alfalfa ferritin and a novel NADPH-dependent aldose/aldehyde reductase enzyme. Transgenic tobacco plants that synthesize alfalfa ferritin in vegetative tissues-either in its processed form in chloroplast or in the cytoplasmic non-processed form-retained photosynthetic function upon free radical toxicity generated by paraquat treatment and exhibited tolerance to necrotic damage caused by viral and fungal infections. We propose that by sequestering intracellular iron involved in generation of the very reactive hydroxyl radicals through a Fenton reaction, ferritin protects plant cells from oxidative damage. Our preliminary results with the other stress-inducable alfalfa gene (a NADPH-dependent aldo-keto reductase) indicate, that the encoded enzyme may play role in the stress response of the plant cells. These studies reveal new pathways in plants that can contribute to the increased stress resistance with a potential use in crop improvement.