Nuclear Space Research Articles

Abstract Nuclear Radiation shielding materials are essential in various industries, especially nuclear power, medical imaging, and space exploration. This research delves into the exploration of radiation shielding efficacy by infusing cement and waste marble composites with micro and nanoparticles of Cadmium Oxide (CdO) and Aluminum Oxide (Al2O3), focusing on key parameters such as half value layer (HVL), tenth value layer (TVL), linear attenuation coefficient (LAC), and mass attenuation coefficient (MAC). These composites show potential in enhancing the shielding performance due to the unique properties of the nanoparticles. We systematically characterize the structural, morphological, and radiation-shielding properties of the composites through experimentation. In addition to the Absorption buildup factor (EABF) was held in this study to help in enhancing the shielding material as it is an important parameter. The outcomes demonstrated that the CdO-Al2O3 particle addition enhanced the composites’ radiation shielding capabilities. Raising the weight% (Wt.%) of CdO-Al2O3 particles improved the efficiency of the shield. The outcomes also showed that nano-sized CdO-Al2O3 particles outperformed micro-sized particles in radiation shielding. The work shows the potential of CdO- Al2O3 doped cement-waste Marble matrix composites for applications including shielding against gamma radiation. This study correspondingly investigates the shielding capabilities using the FLUKA Monte Carlo code. The simulation employed a wide range of photon and neutron energies, up to 100 and 20 MeV respectively. The results show the effectiveness of the introduced composite in attenuating both gamma rays and neutrons, highlighting their potential applications in radiation shielding.

This study employs in situ transmission electron microscopy (TEM) to investigate the dynamic evolution of radiation-induced defects in gallium nitride (GaN) under high temperature (800 °C). The results demonstrate that defect cluster size increases progressively with irradiation dose (up to 2.48 displacements per atom, dpa), while cluster density exhibits a non-monotonic trend, peaking at intermediate doses (0.31–0.62 dpa) before declining due to coalescence of smaller clusters. Aberration-corrected scanning TEM reveals that irradiation generates dislocations, stacking faults, and cavities. Besides, N2 bubbles nucleate even at ultralow doses (0.02 dpa), driven by interstitial N aggregation and vacancy capture. Despite significant radiation damage, GaN maintains its crystalline structure without amorphization at high doses. Besides, there is negligible aggregation of defects around intrinsic dislocations—a behavior attributed to the high migration energy barriers of vacancies and interstitials in GaN. These findings elucidate the intrinsic radiation resistance mechanisms of GaN through atomic-level defect dynamics, providing critical guidance for designing next-generation radiation-tolerant power electronics and radiation detectors in extreme environments such as nuclear reactors and space applications.

This article deals with the effect of Kr15+ ion irradiation on the structure and properties of partially stabilized zirconium dioxide (ZrO2 + 3 mol. % Y2O3) ceramics. Ion irradiation is used to simulate radiation damage typical of operating conditions in nuclear reactors and space technology. It is shown that with an increase in the irradiation fluence, point defects are formed, dislocations accumulate, and the crystal lattice parameters change. At high fluences (>1013 ions/cm2), a phase transition of the monoclinic (m-ZrO2) phase to the tetragonal (t-ZrO2) and cubic (c-ZrO2) modifications is observed, which is accompanied by a decrease in the crystallite size and an increase in internal stresses. Changes in the mechanical properties of the material were also observed: at moderate irradiation fluences, strengthening is observed due to the formation of dislocation structures, whereas at high fluences (>1014 ions/cm2), a decrease in strength and a potential amorphization of the structure begins. The change in the phase composition was confirmed by X-ray phase analysis and Raman spectroscopy. The results obtained allow a deeper understanding of the mechanisms of radiation-induced phase transformations in stabilized ZrO2 and can be used in the development of ceramic materials with increased radiation resistance.

The integrity of DNA is put at risk by different lesions, among which double-strand breaks (DSBs) occur at a lower frequency but have the most life-threatening consequences. The study of DSB repair requires tools that can induce the accumulation of these breaks and includes the use of chemical genotoxins, ionizing radiation, or the expression of sequence-specific nucleases. While genotoxins and irradiation allow for dose-dependent studies, nuclease expression permits assessments at precise locations. In this work, we have leveraged the repetitive nature of the Ty transposon elements in the genome of Saccharomyces cerevisiae and the cutting activity of the RNA-guided Cas9 nuclease to create a tool that combines sequence specificity and dose-dependency. In particular, we can achieve the controlled induction of 0, 1, 15, or 59 DSBs in cells with an otherwise identical genetic background. We make the first application of this tool to better understand the behavior of the apical kinase of the DNA damage response Tel1 in the nuclear space. We found that Tel1 is capable of forming nuclear foci, which are clustered by condensin when DSBs occur in Ty elements. In striking contrast with other DSB-related protein foci, Tel1 foci are in tight contact with the nuclear periphery, therefore suggesting a role for the nuclear membrane in their congregation.

This study presents the development and characterization of CsPbBr3 (CPB) and CPB-poly-(methyl methacrylate) (CPB-PMMA) composite coatings on Fiber Bragg Grating (FBGs)-based sensors for high-sensitivity gamma radiation sensing. CPB precipitates were synthesized using a solvent-based method and uniformly deposited onto the FBGs. The incorporation of PMMA into the CPB matrix enhanced both mechanical stability and adhesion to the FBG surface. Spectral analysis revealed significant Bragg wavelength shifts in response to gamma radiation exposures, indicating strain-optic variations induced by radiation-matter interactions. Comparative investigations between uncoated, CPB-coated, and CPB-PMMA-coated FBGs confirmed that the coatings significantly enhance strain sensitivity and stability. The incorporation of PMMA modified the mechanical response, influencing residual stress and strain attenuation. The advantage of using fiber optic sensors includes the ability to enable multiplexed sensing across large areas, immunity to electromagnetic interference (EMI), and operability in high-temperature environments. Additionally, CPB and CPB-PMMA coatings demonstrated enhanced sensitivity under UV exposure, further highlighting their potential for advanced optical sensing applications in both radiation and UV-intensive environments. These results demonstrate the potential of CPB-based coatings for radiation monitoring in extreme environments, including in nuclear facilities, space missions, and near medical instruments using radiation sources. The findings provide a foundation for further optimization of perovskite-polymer composites to enhance sensor performance and long-term durability in radiation-intensive applications.

This manuscript presents a study on the effects of cryogenic irradiation on P-doped and Al-doped optical fibers, focusing on radiation-induced attenuation (RIA) when exposed to gamma radiation in the near-infrared (NIR) telecom wavelength 1550 nm. Results are compared to those obtained at room temperature under equivalent conditions. A novel P-doped fiber from the Israeli Institute for Advanced Photonics (ICAP) was tested for what we believe is the first time, along with commercially available P- and Al-doped optical fibers. All results are explained in terms of the defects that are associated with specific spectral ranges of each fiber chemistry. Results from the P-doped fiber show no recovery at room temperature and slight opposite recovery at cryogenic temperatures. The Al-doped fiber showed a slight recovery at both room and cryogenic temperatures. A kinetic model was used to extrapolate data up to higher doses, revealing higher RIA at cryogenic temperatures for both fiber types, with P-doped fiber exhibiting a 100% increase in expected saturation dose at cryogenic temperatures. By reporting the first experimental measurements of cryogenic RIA in P-doped and Al-doped fibers, this study sheds light on the underlying defects responsible for RIA at cryogenic temperature and represents an initial step toward developing in-situ cryogenic radiation dosimeters for nuclear fusion reactors, particle colliders, and space missions.

ECIL is a cornerstone public-sector enterprise in Hyderabad, established in 1967 to foster selfreliance in strategic electronics. Over time, ECIL has grown into a multi-disciplinary technology organization excelling in nuclear instrumentation, defence, aerospace, space communication, security, and e-governance. With a strong track record of indigenous innovation and high-profile projects—including electronic warfare systems— it has solidified its role under DAE and earned Miniratna-I status. With annual revenues exceeding ₹3,000 Cr and a workforce of several thousand, ECIL remains a pivotal contributor to India’s strategic electronics ecosystem

Transcription by RNA polymerase II is a fundamental step in gene regulation that mainly occurs in discrete nuclear foci, or transcription compartments, characterized by a high local concentration of polymerases and nascent RNA. Early studies referred to these foci as transcription factories, proposing that they harbour most transcriptional activity and all relevant protein machinery to produce mature RNAs. However, this model of transcriptional organization has long remained controversial owing to its mechanistic uncertainties. Recently, new insights into how these foci may form are being provided by studies of phase-separated transcriptional condensates that encompass RNA polymerases, transcription factors and RNA. Advances in 3D genomics and chromatin imaging are also deepening our understanding of how transcription compartments might facilitate communication between cis-regulatory elements in 3D nuclear space. In this Review, we contrast historical work on transcription factories with recent findings on transcriptional condensates to better understand the architecture and functional relevance of transcription compartments.

The growing need for information technology (IT) in education has resulted in higher energy consumption, more electronic waste, and harmful effects on the environment. As schools and universities aim for sustainable methods, Green Information Technology (Green IT) has become an important way to lessen environmental harm while supporting technology. This paper examines the chances and difficulties of using Green IT practices in schools. It points out significant benefits such as better energy efficiency, lower operating costs, increased awareness of environmental issues, and the use of digital learning tools that match sustainability goals. At the same time, the research finds major challenges like budget limits, lack of proper infrastructure, limited understanding among stakeholders, and the need for strong policy guidelines. By reviewing current research and case studies from both advanced and developing countries, the paper offers helpful suggestions for successfully adopting Green IT. The findings highlight the need for careful planning, policy creation, and skill development to promote a sustainable, technology-driven educational setting. Technology has significantly influenced society and its environment in various ways, facilitating the advancement of more sophisticated economies, including the current global economy. Scientific advancements have introduced numerous technologies to society, such as aircraft technology, automobile technology, biotechnology, computer technology, telecommunication technology, internet technology, renewable energy technology, atomic and nuclear technology, nanotechnology, and space technology, all of which have transformed people's lifestyles and enhanced their comfort[1].

Abstract Let Φ ′ \Phi^{\prime} denote the strong dual of a nuclear space Φ and let C ∞ ⁢ ( Φ ′ ) C_{\infty}(\Phi^{\prime}) be the collection of all continuous mappings x : [ 0 , ∞ ) → Φ ′ x\colon[0,\infty)\rightarrow\Phi^{\prime} equipped with the topology of local uniform convergence. In this paper, we prove sufficient conditions for tightness of probability measures on C ∞ ⁢ ( Φ ′ ) C_{\infty}(\Phi^{\prime}) and for weak convergence in C ∞ ⁢ ( Φ ′ ) C_{\infty}(\Phi^{\prime}) for a sequence of Φ ′ \Phi^{\prime} -valued processes. We illustrate our results with two applications. First, we show the central limit theorem for local martingales taking values in the dual of an ultrabornological nuclear space. Second, we prove sufficient conditions for the weak convergence in C ∞ ⁢ ( Φ ′ ) C_{\infty}(\Phi^{\prime}) for a sequence of solutions to stochastic partial differential equations driven by semimartingale noise.

The folding of the genome in the 3D nuclear space is fundamental for regulating all DNA-related processes. The association of the genome with the nuclear lamina into lamina-associated domains (LADs) represents the earliest feature of nuclear organization during development. Here, we performed a gain-of-function screen in mouse embryos to obtain mechanistic insights. We find that perturbations impacting histone H3 modifications, heterochromatin, and histone content are crucial for the establishment of nuclear architecture in zygotes and/or 2-cell-stage embryos. Notably, some perturbations exerted differential effects on zygotes versus 2-cell-stage embryos. Moreover, embryos with disrupted LADs can rebuild nuclear architecture at the 2-cell stage, indicating that the initial establishment of LADs in zygotes might be dispensable for early development. Our findings provide valuable insights into the functional interplay between chromatin and structural components of the nucleus that guide genome-lamina interactions during the earliest developmental stages.

ABSTRACTThe introduction of a pneumatic supporting system composed of gas springs and hydrostatic bearings in the free‐piston Stirling generator (FPSG) can effectively increase the power density of the nuclear space power plant. In this paper, a 1 kW FPSG with pneumatic supporting system was developed, and the working characteristics of dual gas springs were obtained under an external driving condition. A quasi‐one‐dimensional numerical model is established, the relative error between piston strokes is within 5%, and the maximum phase uncertainty is 5.36° between experimental and numerical results. The generator outputs 1011.3 W with a total thermo‐electric efficiency of 14.85% under the rated condition, and the hysteresis loss of gas springs is 535.6 W, which accounts for 7.85% of the total power input, and the global stiffness reaches 96.43 N/mm. A multitude of influencing factors (including operational, constitutive, and sealing parameters) on the performance of gas springs are evaluated. An expression for the correction coefficient of stiffness with respect to five influencing parameters is established through data regression, as well as an empirical formula for the hysteresis loss as a percentage of the total input power. The correlations indicate that the order of weights affecting the performance of gas springs is as follows: compression ratio, configuration factor, gap thickness, gap length, and wall temperature.

The microtubule-associated protein tau aggregates into oligomeric complexes that highly correlate with Alzheimer's disease (AD) progression. Increasing evidence suggests that nuclear membrane disruption occurs in AD and related tauopathies, but whether this is a cause or consequence of neurodegeneration remains unclear. Using the optogenetically inducible 4R1N Tau::mCherry::Cry2Olig (optoTau) system in iPSC-derived neurons, we demonstrate that tau oligomerization triggers nuclear rupture and nuclear membrane invagination. Pathological tau accumulates at sites of invagination, inducing structural abnormalities in the nuclear envelope and piercing into the nuclear space. These findings were confirmed in the humanized P301S tau (PS19) transgenic mouse model, where nuclear envelope disruption appeared as an early-onset event preceding neurodegeneration. Further validation in post-mortem AD brain tissues revealed nuclear lamina disruption correlating with pathological tau emergence in early-stage patients. Notably, electron microscopy shows that tau-induced nuclear invagination triggers global chromatin reorganization, potentially driving aberrant gene expression and protein translation associated with AD. These findings suggest that nuclear membrane disruption is an early and possibly causative event in tau-mediated neurodegeneration, establishing a mechanistic link between tau oligomerization and nuclear stress. Further investigation into nuclear destabilization could inform clinical strategies for mitigating AD pathogenesis.

We performed a simulation of the time-resolved photoelectron spectrum (TRPES) of trans-azobenzene after ππ∗ excitation in a mixed quantum-classical framework. The electronic structure of the molecule and of its cation was obtained with a semiempirical multireference configuration interaction approach, the nonadiabatic dynamics was simulated with the surface hopping algorithm, and the TRPES was determined by computing the relevant Dyson orbitals. According to our results, the TRPES obtained with a probe photon energy of 6.0eV shows two bands, the one at higher energy being due to the S2 electronic state of the molecule and the other one to the S1 state. For both bands, the main contribution to the spectrum originates from the D0 state of the cation. Our simulated TRPES is in very good agreement with the available experimental data, both in terms of the energetic positions of the bands and their lifetimes. Our findings confirm that the wavelength dependence of the photoisomerization quantum yields of trans-azobenzene is not due to a peculiar nonadiabatic decay process, as previously inferred from the experimental TRPES. Rather, the reason for the violation of Kasha's rule is that different regions of the nuclear phase space are explored in S1, whether this state is populated by direct excitation or by the radiationless decay of S2.

Artificial Intelligence Augmented Cerebral Nuclear Imaging.

Changes in nuclear shape and in the spatial organization of chromosomes in the nucleus commonly occur in cancer, ageing and other clinical contexts that are characterized by increased DNA damage. However, the relationship between nuclear architecture, genome organization, chromosome stability and health remains poorly defined. Studies exploring the connections between the positioning and mobility of damaged DNA relative to various nuclear structures and genomic loci have revealed nuclear and cytoplasmic processes that affect chromosome stability. In this Review, we discuss the dynamic mechanisms that regulate nuclear and genome organization to promote DNA double-strand break (DSB) repair, genome stability and cell survival. Genome dynamics that support DSB repair rely on chromatin states, repair-protein condensates, nuclear or cytoplasmic microtubules and actin filaments, kinesin or myosin motor proteins, the nuclear envelope, various nuclear compartments, chromosome topology, chromatin loop extrusion and diverse signalling cues. These processes are commonly altered in cancer and during natural or premature ageing. Indeed, the reshaping of the genome in nuclear space during DSB repair points to new avenues for therapeutic interventions that may take advantage of new cancer cell vulnerabilities or aim to reverse age-associated defects.

The high-energy radiation in nuclear energy, space missions, and other radiation-related fields would accelerate the deterioration of polymers, greatly reducing their service life and reliability. Here, a new concept of radiation resistance has been proposed, which is to reduce the effect of radiation degradation on polymer properties by constructing a radiation-stable macromolecular network. Concretely, this strategy was achieved by introducing a stable coordination interaction between macromolecules, and radiation-resistant elastomers (PG-Zn) were prepared. In radiated PG-Zn, the intermolecular coordination interaction could maintain the chain network well, even though its main chain has undergone a chain-breaking reaction. Therefore, after 300 kGy irradiation, PG-Zn still maintained nearly 18 MPa strength and 650% elongation at break, and its tensile deformation hysteresis rate was almost unchanged. The PG-Zn could be further modified, and the modified elastomer retains more than 80% of its mechanical properties after 300 kGy radiation, which is the most radiation-resistant elastomer reported to date. In addition, the design has good scalability and could be used to prepare radiation-resistant sensors, showing more than three times the service life of the ordinary group under irradiation. This radiation-resistant design presented a novel and promising approach for solving the radiation-aging problem of polymers.

Precise spatiotemporal regulation of gene expression is critical for the development and functioning of complex, multicellular organisms. Enhancers play a fundamental role in the regulation of gene expression, but the molecular underpinnings of enhancer-mediated gene activation remain poorly understood. Many mammalian genes are dependent on the activity of multiple enhancers, which can be separated from their target genes by large genomic distances. Accurate gene regulation therefore relies on specific interactions between enhancers and their target genes in 3D nuclear space. In this review, we discuss recent insights into the mechanisms by which enhancers cooperate to regulate precise and robust gene expression levels. We also review recent progress in our understanding of the molecular drivers of specific 3D interactions between enhancers and their target genes. We conclude by discussing current models of the molecular mechanisms by which enhancers activate gene expression in their 3D chromatin context.

The field-reversed configuration (FRC), a compact toroidal plasmoid, has a range of potential applications, particularly in nuclear fusion, space propulsion, and plasma research. Various formation methods have been developed to create the magnetic topology required for stable plasma confinement. Here, we propose and investigate a novel formation method using a plasma gun as the plasma source and a DC background magnetic field as the bias field. This approach reduces the device's dependence on high-voltage pulse power supplies for FRC formation and enhances magnetic flux retention. In our experiments, we observed the splitting of elongated FRCs. Specifically, FRCs with an elongation greater than 1.7 and low trapped magnetic flux—a central-to-external magnetic field ratio below 0.6—tended to split during translation. This study demonstrates a new technical scheme for FRC formation, and the experimental results may contribute to the FRC optimization and stability control during translation and compression.

ABSTRACT Smectic ferroelectric liquid crystal (FLC) with microsecond order switching has the potential for use in display and non-display type applications. There has also been a strive to develop FLC materials that can tolerate hostile environments like nuclear installation centres and space applications. To understand the behaviour of FLCs under such radiation-prone areas, we irradiated a room-temperature smectic FLC mixture with N+ ion beam, the most commonly available heavy ion inside and outside the Earth’s atmosphere. The thermal, dielectric and electro-optic properties of the FLC mixture were measured as functions of temperature and ion beam fluence (1015, 1016 and 1017 ions/cm2). The phase transition temperatures, permittivity, optical tilt angle and spontaneous polarisation of the mixture decreased significantly, indicating a reduction in the order parameter with irradiation. The conductivity of the irradiated mixture increased considerably likely due to the production of ions through the irradiation process. As spontaneous polarisation decreased and conductivity increased, switching time increased in the irradiated systems. This increase was moderate at low levels of exposure but became more pronounced at higher levels, indicating that degradation of display-related parameters may be minimal at lower doses of ion beam exposure but more severe at higher doses.