Nuclear Characteristics Research Articles

Interaction-sedimentation strategy for highly efficient removal of refractory humic substances in biologically treated wastewater effluent: from mechanistic investigation to full-scale application

Based on the accurate characterization of the binding sites of humic substances (HS) and their binding coefficients with ferric ions (Fe(III)), a coupled interaction-sedimentation (CIS) technology was proposed for dealing with HS in the biologically treated wastewater effluent (BTWE) from a full-scale antibiotic production wastewater treatment plant. The infrared spectral and carbon-13 nuclear magnetic resonance characteristics showed that (i) protonated carboxyl groups in HS were the main binding sites for Fe(III) and HS, (ii) one carboxyl group of HS interacted with one ferric ion, (iii) the Fe(III)-binding ability of fulvic acids (FA) was 2.8 times as much as that of humic acids (HA) when FA and HA coexisted, and (iv) the presence of non-humic substances in the effluent organic matter (EfOM) amplified the Fe(III)-binding ability difference between FA and HA to 4.9 times. Afterwards CIS technology was successfully optimized and applied in engineering-scale and superior HS and EfOM removal efficiencies of 94.2% and 84.0% were reached, respectively. The CIS technology and its engineering application in this study not only fulfill the direct discharging standard for antibiotic production wastewater, but also have the potential for replication in broader advanced treatments for BTWE.

Distribution characteristics of movable fluid in tight sandstone based on nuclear magnetic resonance

Movable fluid parameter is an important index to evaluate the seepage characteristics of tight sandstone reservoir. Combined with high-pressure displacement and nuclear magnetic resonance movable fluid testing principle, the nuclear magnetic resonance movable fluid characteristics of six typical tight sandstone core samples of Xujiahe Formation in Central Sichuan Basin were studied. Based on mercury injection capillary pressure curve, the nuclear magnetic resonance T2 spectrum distribution was converted into pore throat According to the radius distribution, the minimum pore throat radius of the movable fluid and the contribution of different pore sizes to the movable fluid are determined. The research shows that the movable fluid saturation of the tight sandstone reservoir in the second member of Xujiahe Formation in Central Sichuan is closely related to the pressure difference, with good logarithmic correlation, and the main contribution to the movable fluid saturation is the reservoir space > 0.1 μm. 70% of the total movable fluid saturation is injected at a lower pressure (about 5MPa). In the later stage, high pressure injection can only enter the reservoir pore with small pore size, and the total amount is small and increases slowly. Therefore, the total contribution of high pressure drive to gas saturation in the later stage is small.

Molecular Evolutionary Analyses of Euplotes Species Living in Freshwater and Marine Habitats: A Mitogenomic Perspective

Ciliates are the most complex unicellular eukaryotic organisms, which play important roles in various ecosystems. The Euplotes is a dominant genus in the ciliates Euplotida and consists of approximate one hundred species. They distribute widely in environments with various salinity levels including freshwater, brackish, seawater as well as hypersaline. In this study, we obtained four mitochondrial genomes of Euplotes species, using both high throughput sequencing and Sanger sequencing. Combined with two previously reported Euplotes mitochondrial genomes, we analyzed their gene structure, codon usage pattern as well as phylogenetic relationship. We found that gene rearrangement exists in Euplotes and codon usage bias is different among these species. Phylogenetic analyses based on both mitochondrial and nuclear genes further unveiled that Euplotes spp. living in similar salinity levels tend to be clustered together. Moreover, we found that the dN/dS ratios of two mitochondrial genes, cox1 and cox2, are significantly different between marine and freshwater species, indicating the salinity could act as a barrier for the Euplotes species distribution. We also recommended mitochondrial genes to discriminate the species with highly similarity of Euplotes which could not be easily distinguished by nuclear gene marker and morphological characteristics. This study provides novel resources to improve our understanding of Euplotes evolution and also its adaptation to habitats with different salinity levels.

Neutronic performance of the hybrid-low power research reactor for education and neutron applications

Korea Atomic Energy Research Institute (KAERI) has designed a second-generation Hybrid-Low Power Research Reactor (H-LPRR), which can be used as a critical assembly and conventional research reactor simultaneously. Particularly, the fuel assemblies and the reflectors of the H-LPRR are designed to stand alone without any supporting equipment and to replace each other. Its eight irradiation holes are located on the edge of the core and are applicable to neutron activation analysis and radioisotope production. In this study, some of the important nuclear characteristics are provided such as the control absorber rod worth, shutdown margin, safety reactivity factor, which are calculated by using the MCNP6.1 code with the ENDF/B-VII.0 library. Following a reactivity insertion accident, the power trend as a function of the time was also analyzed using the RELAP5/MOD3.3 code. The main safety parameters of the H-LPRR and MNSR were compared to quantitatively evaluate the neutronics performance of the H-LPRR. From these results, it can be confirmed that the H-LPRR possesses high performance in terms of nuclear design and safety analysis, and it can be a suitable option for countries considering replacement of existing and aging low power research reactors.

Optical and nuclear radiation protection characteristics of lithium bismo-borate glasses: Role of ZrO2 substitution

The current study is intended to examine the optical, structural and photon/neutron shielding qualities of a group of different ZrO2 content doped 60B2O3 +20Bi2O3+(20-x)Li2O + xZrO2 glasses, labeled as BBLZ1, BBLZ2, BBLZ3, BBLZ4 and BBLZ5 manufactured via the melt quenching technique. The specific gravity of the glasses was boosted with increasing ZrO2 additive and molar volume exhibited the opposite trend versus the density. XRD patterns were obtained to reveal the amorphous structure of the glasses. Spectra of optical absorption for BBLZ glasses were recorded in the wavelength region 200–1100 nm. The direct band gap (Eg) values dropped from 4.24 to 3.87 eV with the boosting ZrO2 content while the indirect Egs declined from 3.78 to 3.18 eV. The refractive index grew as the ZrO2 substitution ratio enhanced. To determine photon shielding parameters of BBLZ glasses, the mass attenuation coefficients (MAC) were gained viz Py-MLBUF online program for the 0.015–15 MeV gamma ray energies. Several shielding parameters of BBLZ glasses such as Half Value Layer (HVL), Exposure Buildup Factor (EBF) and Mean Free Path (MFP) were reached using MAC values. The highest MACs differ from 68.188 cm2/g to 0.036 cm2/g for BBLZ5 glass while the lowest μ/ρ values varying from 69.413 cm2/g to 0.036 cm2/g belong to the BBLZ1 glass. The thinnest MFP and HVL values were observed in the BBLZ5 glass with the highest ZrO2 contribution (4 mol %). Adding ZrO2 to the fabricated glasses reduced photon buildup. BBLZ5 glass was determined to be the safest neutron shield due to its high density. It can be concluded that ZrO2 addition with increasing rates to lithium bismo-borate glasses reinforced both optical properties and nuclear radiation security qualities.

Comparative Analysis of Perfectionism and Value-Semantic Barriers of the Student's Personality

The research compares perfectionism as a personal quality and its value-semantic barriers during the acquisition of the first professional skills in order to provide psychological support for social adaptation. It is argued that timely diagnosis of such condition can clarify the necessary psychotherapeutic interventions. A program of point studies to present new empirical data and formulate new relationships between structural and nuclear characteristics of the individual was formalized. The classical quasi-experimental approach of D. Campbell was used for analysis. The achieved results can help to form a more critical scientific view on the studied problem.

Abstract PS6-09: An AI-digital breast cancer risk discrimination platform (PreciseDx) using a representative H&E image and selected clinical variables accurately categorized patients with oncotype Dx low risk recurrence scores (RS)

Abstract Background: Clinical practice guidelines emphasize the critical importance of grading and stage in breast cancer treatment. Although histologic grade is subjective, non-quantitative, skill-dependent, and oftentimes inaccurate it remains an independent prognostic feature and therefore plays a direct role in patient management including neoadjuvant therapy vs surgery, and interpretation of genomic studies. We developed an AI-based platform which combines digital H&E features with select clinical variables to assess risk of breast cancer recurrence and evaluated ability to predict Oncotype low risk RS categorization. Methods: Retrospective study to identify a subset of Mt. Sinai, NY invasive ductal breast cancer (IDC) patients from 2010-2016 with H&E stained slides, clinical features and OncotypeDx recurrence scores (RS). Recurrence endpoint(s): local- regional, distant-recurrence free and overall survival. Digital images generated with Philips scanning system; reviewed by two pathologist for tumor content and quality prior to image analysis and feature extraction. Support vector machine learning models were used for initial feature performance and final models generated. Positive predictive value (PPV), sensitivity (S) and likelihood ratios (LR) were used for performance. Results: 391 patients: mean age 57 years, 100% Stage I/II, 59% Grade 2, and 6% LN+ve 0-3; 97% IDC, 100% ER+ve, 94% PR+ve, 0% Her2 amplified; median follow-up 61 months; 323 (83%) low risk (</=25) RS and 68 (17%) high risk RS (>25). There were 23 events (6%) and 13 (56%) were locoregional recurrence. PreciseDx model with age, and PR levels combined with imaging features reflective of mitotic activity and nuclear characteristics (clinical grade not selected) correctly identified LR RS categorization: PPV of 91%, [95CI 0.87-0.94], Se 92% [0.86-0.95] and positive / negative likelihood ratio : 6.8, and 0.5, respectively. Conclusions: Application of an AI-digital breast cancer risk assessment platform using only the H&E image and limited clinical data successfully classified low risk RS patients with high accuracy. Future models will extend outcome to 10 years and evaluate treatment selection and duration Citation Format: Michael Joseph Donovan, Nina Shpalensky, Marcel Prastawa, SM Abishek, Richard Scott, Mary Sawyer, Jack Zeineh, Gerardo Fernandez. An AI-digital breast cancer risk discrimination platform (PreciseDx) using a representative H&E image and selected clinical variables accurately categorized patients with oncotype Dx low risk recurrence scores (RS) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-09.

Composition and structural characterization of pectin in micropropagated and conventional plants of Premma puberula Pamp.

The metabolites produced by plants can be enhanced by plant tissue culture. In Premma puberula Pamp., the pectin content in leaves is 30 %–40 %, and it is widely used in the food industry and medicine. However, inefficient propagation has seriously restricted the utilization of pectin resources. Therefore, we established an efficient micropropagation technology for P. puberula through comparative analysis in mature leaves of regenerated and conventionally propagated plants. The results showed that the pectin composition of their leaves was similar in terms of galacturonic acid, monosaccharide composition, degree of esterification, functional groups, nuclear magnetic resonance spectrum and morphological characteristics. Furthermore, micropropagated plants had better hardness, gumminess and chewiness characteristics than conventionally propagated plants and were similar in emulsion stability, adhesiveness, springiness, cohesiveness and viscoelasticity. Therefore, micropropagation technology will provide an important guarantee for the industrial production of pectin from P. puberula. The technical essentials include callus induction, embryoid formation, and root induction, followed by acclimatization and transplanting.

Optimization design and application study on a high temperature resistant borated polyethylene shielding material

This paper carried out an optimization design and application study on a high temprature resistant borated polyethylene shielding material, according to the nuclear power plant source characteristics and special protection requirements. The composition of borated polyethylene shielding material was optimized based on the genetic algorithm and Monte Carlo methods, then it was realized by blending modification and graft copolymerization to improve the high temperature resistant, shielding and mechanical properties. Finally, comprehensive properties such as mechanical, neutron shielding, irradiation resistance and high temperature resistance experiments were verified with the ordinary borated polyethylene and polypropylene. Those just proved the optimized borated polyethylene shielding material has excellent performance comparatively, especially it could keep complete structure in a high temperature environment up to 190°C during 48 hours, meeting the requirements of radiation protection safety for nulear power plant completely.

Investigation of Radiolabeling Efficacy by Enhancement of the Chemical form of no Carrier Added 177Lu Isolated by Electro Amalgamation Process.

Due to the suitable nuclear decay characteristics, 177Lu is an attractive radionuclide for various therapeutic applications. The non-carrier added form of177Lu has drawn much attention because of its high specific activity needed in radiolabeling studies. There have been several separation methods for NCA177Lu production. Among the various separation methods, the electro-amalgamation separation method has got a large potential for large scale production. Li presence is a significant problem in this separation method, which seriously affects the radiolabeling efficiency. In this study, Li was separated from the final product of electro-amalgamation separation by adding an ion-exchange chromatography column to the separation process. NCA 177Lu was obtained by 84.09% ELM separation yield, 99.9% radionuclide purity and, 65 Ci/g specific activity. Then, 177Lu (177LuCl3 chemical form) was separated from Li using the ion exchange chromatography method by a separation yield of 94%. The obtained results of the radiolabeling efficacy studies showed that the radiochemical purity and radio-complex stability were significantly increased by separating NCA 177Lu from Li. This new separation setup consisting of two steps allows using 177Lu of such a favorable quality for labeling studies.

CBX8 acts as an independent RNA-binding protein to regulate the maturation of miR-378a-3p in colon cancer cells.

CBX8 is the core component of the PCG family protein PRC1 complex. It is overexpressed in many solid tumors and plays an important role in the prognosis and biological behaviors of tumors such as occurrence, development, invasion, and metastasis. However, exploration of the role and molecular mechanism of CBX8 in tumors is still in its infancy. Our study found that the down-regulation of CBX8 expression by RNA interference induced differential expression of several microRNAs in human colon cancer cells. The 5 most differentially expressed miRNA precursors (pre-miRNA) (hsa-miR-363-3p, hsa-miR-378a-3p, hsa-miR-371b-3p, hsa-miR-361-3p, and hsa-miR-576-3p) share a common motif sequence: ARAAAKUGCMC. We selected miR-378a-3p and further revealed that the negative regulation of miRNA expression by CBX8 mainly occurs in the processing of pre-miRNA to mature miRNA. CBX8 uses its own RNA-binding domain to interact with pre-miRNA, and is dependent on its own nuclear localization characteristics to limit nucleoplasmic transport of pre-miRNA. Changing the characteristic sequence of pre-miRNA or mutating the RNA-binding domain and nuclear localization signal of CBX8 can effectively weaken the regulation of miR-378a-3p expression by CBX8. However, our experimental results showed that miR-378a-3p inhibited the malignant expression of human colon cancer cells by targeting PDIA4, resulting in increased activity of caspases-3 and -7. In summary, our study suggests that CBX8 acts as an independent RNA-binding protein to regulate miRNA expression. Simultaneously, this study shows the correlation between the CBX8/miR-378a-3p/PDIA4 pathway and the malignant biological properties of colorectal cancer, suggesting this proposed pathway as a possible therapeutic target for human cancers.

Clinicopathological Study of Spectrum of Muscle Disorders in a Tertiary Care Hospital

Introduction: The diagnostic approach to muscle disorders is often challenging due to paucity of literature, unavailability of ancillary facilities, affordability and improper sample collection. The role of pathologist in terms of categorising the muscle biopsy interpretation with limited resources plays an imminent role in guiding clinicians for further therapeutic approach. Aim: To analyse spectrum of various muscle disorders and to relate their clinical and histopathological findings. Materials and Methods: This was observational retrospective as well as prospective study of 63 muscle biopsies received during 10 years period from June 2009 to June 2019, at Department of Pathology in Grant Government Medical College, Mumbai, India. Slides of muscle biopsies received prior to June 2017 were restained and reviewed while muscle biopsies after this period were studied prospectively. Various histomorphological and histopathological (fascicular architecture, variation in size and shape of fibers, necrosis and degenerative/regenerative changes, nuclear characteristics, type and distribution of inflammatory cells along with interstitial changes) features were studied in detail and the findings were compared with similar previous studies. These findings when clubbed together with clinical, biochemical and Electromyography (EMG) findings, to guide the path towards appropriate diagnosis. Results: The present study evaluated and analysed 63 muscle biopsies, clinically, histopathologically and histomorphologically. Mean age was 30.6 years, 43 (68.25%) patients were males and 20 (31.75%) patients were females. A number of 12 (19.04%) patients were clinically diagnosed as having limb- girdle muscular dystrophy, followed by 9 (14.28%) patients as inflammatory myositis. Eight patients (12.69%) were diagnosed as Polymyositis (PM), five (7.93%) as Dermatomyositis (DM), one (1.58%) patient each of juvenile DM and inclusion body myositis. Histopathologically, the cases diagnosed were PM- 14 cases (22.22%) followed by muscular dystrophy (excluding limb-girdle muscular dystrophy)- 12 cases (19.04%) and limb- girdle muscular dystrophy- 9 cases (14.28%). conclusion: Although molecular and genetic studies are need of hour, histomorphological features helps in proper categorisation of cases, however close liaison between pathologist and clinicians is essential and histopathological findings should only be interpreted in light of clinical manifestations and laboratory findings.

Дуалистический характер оценочных высказываний в англоязычном драматургическом дискурсе

The article is devoted to the problem of interaction between emotional and rational aspects of evaluative utterances within English drama discourse. The aim of the study is to analyze the dualistic nature of evaluative messages and develop a set of demarcation criteria which would contribute to their classification. The material for the analysis is a sample of 2,000 evaluative utterances presented in the plays by contemporary British and American playwrights. The study was carried out in line with the linguoaxiological approach and employed the corresponding methods. On the basis of linguoaxiological interpretation, the following criteria were developed: 1) the hierarchical relationship of subjective and objective factors in the evaluative utterance; 2) the level of spontaneity and situational awareness; 3) the degree of addresser-addressee pragmatic interaction. Linguistic characteristics were mapped to determine the communicative specifics of the designated types of evaluation in a stylized dialogue. The typical lexical means of evaluative modulation were identified, as well as syntactic models which act as the nuclear characteristics of emotional-evaluative and rational-evaluative messages at the linguistic level; phonographic and enantiosemic means which determine the emotional orientation of a judgment were analyzed. The presented statistical data reflect the frequency ratio of positive and negative evaluative utterances according to the superiority of the emotional evaluative or rational evaluative aspect. It is concluded that predominance of the relevant side in the evaluative utterance determines the complex verbal representation of the evaluative attitude and generates the pragmatics of evaluative utterances as reactions or opinions within stylized communication in English.

Study of various nuclear features of papillary thyroid carcinoma in other thyroid lesions

Introduction: Papillary thyroid carcinoma is the only thyroid malignancy that is diagnosed on the basis of its nuclear characteristics, regardless of cytoplasmic features, growth patterns or immunohistochemistry. Although nuclear features have become hallmark for the diagnosis, they are neither constant nor specific. They can be seen in other tumours and non-tumours condition of thyroid. With the aim to know the frequency of various nuclear features of papillary thyroid carcinoma in other thyroid lesions and also to find out which of the various nuclear features are most diagnostic of papillary thyroid carcinoma, this study was done. Materials and Methods: The present study was conducted on Fine needle aspiration cytology of thyroid lesions where corresponding histopathological diagnosis was available, from 2010 to 2016. All cytology smears of were reviewed by two investigators who were blinded with respect to the final histopathological diagnosis. Results: 155 cases were included in the study; category 2 was the most common constituting 76%, followed by category 6 which was 35%. Frequency of various nuclear features of papillary carcinoma in other thyroid categories varied from 10% to 33%. Conclusion: Frequency of various nuclear features of papillary carcinoma in other thyroid categories varied from 10% to 33% and Intranuclear cytoplasmic inclusions are the most diagnostic nuclear features of papillary carcinoma. Keywords: Papillary thyroid carcinoma, Nuclear inclusions, Nuclear grooves, Fine granular chromatin.

Inhibitory effects of nodakenin on inflammation and cell death in lipopolysaccharide-induced liver injury mice

BackgroundNodakenin, a coumarin glucoside isolated from the roots of Angelica biserrata, has been reported to have anti-inflammatory, antibacterial, anticancer effects. However, despite these studies, the potential liver protective effects of nodakenin in inflammatory liver injury models have not been reported. MethodsA mouse model of inflammatory liver injury was induced by injection of lipopolysaccharide (LPS) (15 mg/kg, intraperitoneally (i.p)). Liver tissue AST, ALT, ROS, T-GSH and T-SOD were analyzed by ELISA. The concentrations of TNF-α, IL-6, and IL-1β in serum of LPS-induced inflammatory liver injury mice were analyzed. The mRNA expression levels of GPx1, catalase, SOD1, SOD2, TNF-α, IL-6, IL-1β, iNOS and COX-2 were analyzed using real-time PCR. The expressions of MAPK, IRF3, NF-κB, Nrf2, HO-1, caspase-3 and caspase-7 were analyzed using western blotting. Liver tissue was stained with IHC to confirm NF-κB, Nrf-2, HO-1, caspase-3, Bax, and Bcl2. Tunnel analysis was performed to confirm the fragmented nuclear DNA characteristics of apoptosis. ResultsThe administration of nodakenin (10 and 30 mg/kg) reduced serum aminotransferase levels compared to LPS-induced liver damage and significantly improved the oxidative state of liver tissue and pathological damage. Moreover, inhibited the phosphorylation of transforming growth factor beta (TGF-β)-activated kinase (TAK)-1 in LPS-induced inflammatory liver injury model, and significantly inhibited the transcriptional of nuclear factor-kappa B (NF-kB) and the secretion of pro-inflammatory mediators. In addition nodakenin pre-treatment also attenuated hepatocyte death by regulating apoptosis-related mitochondrial proteins, such as cysteinyl aspartate specific proteinase 3 (caspase 3), poly (ADP-ribose) polymerase (PARP), B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax). ConclusionOur findings suggest that nodakenin has anti-inflammatory, anti-oxidant and anti-apoptotic activity and may be an adjunctive prevention agent for liver injury.

Assessment of cytological features of glandular lesions of the cervix on conventional smear preparations-a comprehensive study from a tertiary care hospital.

Atypical glandular cells (AGC) as a diagnostic category in cervicovaginal cytology remains as a challenge to cytopathologists. The aim of the present study is to identify the cytological features helpful in categorizing AGC as reactive or neoplastic upon correlation with histology. The study was a retrospective review of cervical smears, with histopathological follow up, reported as glandular lesions for a period of 9 years. The architectural and nuclear features studied were adapted from The Bethesda System (TBS) to stratify the lesions as AGC, AGC-FN (atypical glandular cells favour neoplasia) and adenocarcinoma. The cytological categories were correlated with histology. A total of 89 cases of which 67 (AGC NOS = 34, AGC FN = 19, adenocarcinoma = 14) with histology were reviewed. Neoplastic lesions were encountered in 14 cases (34.6%). Of the cases diagnosed as AGC-NOS, AGC-FN and adenocarcinoma, 26.5%, 68.4% and 100% respectively were neoplastic on histopathology. Squamous lesions accounted for 14.9% of all the glandular lesions. Rosette or acinar formation and loss of polarity frequently observed in neoplastic lesions as compared to reactive changes (p = 0.0004, p = 0.001). Of the nuclear features, nuclear hyperchromasia or coarse clumping of chromatin along with nuclear membrane irregularity and nuclear pleomorphism was frequently associated with neoplastic lesions as compared to reactive conditions (p = 0.007, p = 0.001, p = 0.0002). A diagnosis of AGC at cytology harbors significant number of malignant lesions when confirmed on biopsy. Architectural features complemented with nuclear characteristics helps in differentiating between reactive and neoplastic conditions. Hence stratifying glandular lesions at cytology according to TBS helps in the management.

PERSONAL AND PROFESSIONAL CHARACTERISTICS OF AN INCLUSIVE EDUCATION TEACHER FROM COMPETENCY-BASED APPROACH POSITION

The relevance of the theoretical study presented in the article is due to the need for scientific support for the training of teachers for activities in the context of inclusive education. The competency-based approach is the theoretical basis for the development of teacher’s professional activity model that meets the requirements of taking into account the specifics of educational needs of students from different groups. However, the positions of competency-based approach are interpreted ambiguously in pedagogy, and this complicates its theoretical and empirical application. The purpose of this article is to analyze the competency-based approach as a concrete scientific methodology for modeling the personal and professional characteristics of an inclusive education teacher. As leading methods we used: analysis, synthesis, generalization, modeling. The results obtained made it possible to identify both the possibilities and limitations of the competency-based approach in the study and justification of the personal and professional characteristics of pedagogical activity. Its use is advisable in conjunction with basic research of professional pedagogical activity, revealing its essential semantic, nuclear characteristics. It is indicated that as a conceptual basis for applying the competency-based approach to the practice of inclusive education it is proposed to consider N.V Kuzmina’s theory of personality professionalism and activity, which is heuristic to the contemporary research problems of transprofessionalism of a specialist.

Development and Performance Evaluation of Solid-Free Drilling Fluid for CBM Reservoir Drilling in Central Hunan

Solid-free drilling fluid is a matter of cardinal significance in the course of Coal bed Methane (CBM) reservoir drilling. This study evaluated the performance of solid-free CBM drilling fluid in central Hunan. Three types of surfactants, namely TX-10 (nonionic), HSB1618 (zwitterionic) and penetrant T (anionic), were added in basic fluid at various concentrations of 0.05, 0.10 and 0.15% (m/m). This study comprised of drilling fluid rheology, sample mineral analysis, sample nuclear magnetic resonance (NMR) scanning, sample wettability, and sample surface micro characteristics tests. The results show that TX-10 and HSB1618 enhance the rheological properties of drilling fluid, such as yield point and gel strength. Penetrant T has opposite effect on it. It was found that the minimum American Petroleum Institute (API) filtration is only 0.3 mL. This study adopted a new method using laser particle size analyzer to evaluate suspension performance. Based on the surface micro characteristics of the sample and the NMR scanning tests, it is found that the residual amount of basic fluid + HSB1618 in the sample is the smallest. The wettability modification curve indicates that three surfactants decrease the sample’s hydrophobicity. With the increase of surfactant concentration, all above parameters change regularly. The basic fluid + 0.10% HSB1618 has the strongest hydrophobicity for sample at pH = 10. This study obtained a set of solid-free drilling fluid system, which provides better suspension capacity and large contact angle and reduces residue of drilling fluid in CBM reservoir. Ultimately, it can accelerate the desorption of coal gas and reduce damage to the reservoir.

Impact of uranium oxide (UO2) fuel with molybdenum (Mo) inserts on pressurized water reactor performance and safety

This work investigates nuclear reactor performance and safety characteristics of UO2 with high thermal conductivity Mo insert structures by using multiphysics modeling techniques. The purpose of this study is to use scoping analyses to quantify the impact of using Mo inserts from neutronic and heat transfer standpoints. Attention is given to reactor performance parameters, such as cycle length, maximum fuel temperature, temperature gradients in the fuel, and stored energy in the fuel. The finite-element code BISON and the Monte Carlo particle transport code Serpent were used to perform sensitivity analyses on the Mo insert geometry to optimize the insert design and inform larger scale modeling that required the homogenization of the UO2 and Mo. Although BISON is often used as a fuel performance analysis tool, it is used in this context for heat transfer analysis only. Fuel performance optimization is outside the scope of the current study, but would be important for future work focused on this concept. The results showed that the insert had little impact on neutronic performance and that homogenizing the UO2 and Mo was acceptable for reactor physics calculations. Reactivity temperature coefficients calculated using homogeneous UO2-Mo were shown to be relatively similar to UO2, but higher Mo content and 235U enrichment can reduce the worth of soluble boron and control rods. The effect of insert geometry on heat transfer was much greater, and an approximately 15–20% difference in maximum fuel temperature was predicted between the best and worst performing heat transfer geometries. Thermal conductivity calibration based on the finite element analysis results was performed to improve the accuracy of temperature predictions in reactor analysis models that homogenized the UO2-Mo fuel. Compared with UO2 in a pressurized water reactor (PWR), the optimized UO2-Mo design increased the margin to fuel melt by 13–32% across the fuel cycle, but it requires the 235U enrichment to exceed 5% to match the cycle length of conventional UO2.

Optimized methods for production and purification of Titanium-45

Titanium-45 (t1/2 = 3.08 h) is a radiometal with excellent nuclear characteristics, including a high positron branching ratio (85%) and low average positron energy (0.439 MeV), for the development of PET imaging agents. 45Ti was produced via the 45Sc(p,n)45Ti reaction on the University of Alabama at Birmingham TR24 cyclotron in GBq quantities. Optimized separation methods were developed and preliminary radiochemistry studies were also carried out. This work shows 45Ti is a promising radiometal for future studies.