scholarly journals A Review of Nanomaterial Based Scintillators

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7701
Author(s):  
Sujung Min ◽  
Hara Kang ◽  
Bumkyung Seo ◽  
JaeHak Cheong ◽  
Changhyun Roh ◽  
...  

Recently, nanomaterial–based scintillators are newly emerging technologies for many research fields, including medical imaging, nuclear security, nuclear decommissioning, and astronomical applications, among others. To date, scintillators have played pivotal roles in the development of modern science and technology. Among them, plastic scintillators have a low atomic number and are mainly used for beta–ray measurements owing to their low density, but these types of scintillators can be manufactured not in large sizes but also in various forms with distinct properties and characteristics. However, the plastic scintillator is mainly composed of C, H, O and N, implying that the probability of a photoelectric effect is low. In a gamma–ray nuclide analysis, they are used for time–related measurements given their short luminescence decay times. Generally, inorganic scintillators have relatively good scintillation efficiency rates and resolutions. And there are thus widely used in gamma–ray spectroscopy. Therefore, developing a plastic scintillator with performance capabilities similar to those of an inorganic scintillator would mean that it could be used for detection and monitoring at radiological sites. Many studies have reported improved performance outcomes of plastic scintillators based on nanomaterials, exhibiting high–performance plastic scintillators or flexible film scintillators using graphene, perovskite, and 2D materials. Furthermore, numerous fabrication methods that improve the performance through the doping of nanomaterials on the surface have been introduced. Herein, we provide an in–depth review of the findings pertaining to nanomaterial–based scintillators to gain a better understanding of radiological detection technological applications.

Chemosensors ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 239
Author(s):  
Sujung Min ◽  
Youngsu Kim ◽  
Kwang-Hoon Ko ◽  
Bumkyung Seo ◽  
JaeHak Cheong ◽  
...  

Plastic scintillators are widely used in various radiation measurement applications, and the use of plastic scintillators for nuclear applications including decommissioning, such as gamma-ray detection and measurement, is an important concern. With regard to efficient and effective gamma-ray detection, the optimization for thickness of plastic scintillator is strongly needed. Here, we elucidate optimization of the thickness of high-performance plastic scintillator using high atomic number material. Moreover, the EJ-200 of commercial plastic scintillators with the same thickness was compared. Two computational simulation codes (MCNP, GEANT4) were used for thickness optimization and were compared with experimental results to verify data obtained by computational simulation. From the obtained results, it was confirmed that the difference in total counts was less than 10% in the thickness of the scintillator of 50 mm or more, which means optimized thickness for high efficiency gamma-ray detection such as radioactive 137Cs and 60CO. Finally, simulated results, along with experimental data, were discussed in this study. The results of this study can be used as basic data for optimizing the thickness of plastic scintillators using high atomic number elements for radiation detection and monitoring.


Author(s):  
Hidehito Nakamura ◽  
Hisashi Kitamura ◽  
Ryuta Hazama

This study demonstrates that the energy resolution of a newly developed 100 per cent pure polyvinyltoluene (PVT) plate allows its use as a base material for a plastic scintillator. The energy resolution, which is a key element for high-performance radiation detectors, was Δ E / E =8.41±0.07% (full width at half maximum (FWHM)) for 976 keV K-line conversion electrons from a 207 Bi source. On the basis of results from 207 Bi and 137 Cs sources, the observed energy resolution of the PVT plate, Δ E / E =8.2/ E 1/2 % (FWHM), was slightly better than that of a typical plastic scintillator (BC-408), Δ E / E =8.7/ E 1/2 % (FWHM), with E in units of MeV. These results prompted us to search for other new base materials for plastic scintillators. In this study, we examined polyethylene terephthalate (PET) bottles, a common source of domestic plastic waste. We demonstrated that a lump of heat-proof PET bottles is fluorescent; moreover, there is excellent compatibility of the fluorescence with the quantum efficiency of typical photomultiplier tubes. This inexpensive source of plastic appears suitable for radiation measurements and as a base material for plastic scintillators. Future studies on the radiation response of plastics should lead to the development of higher performance and more eco-friendly radiation detectors.


2020 ◽  
Vol 12 (2) ◽  
pp. 19-50 ◽  
Author(s):  
Muhammad Siddique ◽  
Shandana Shoaib ◽  
Zahoor Jan

A key aspect of work processes in service sector firms is the interconnection between tasks and performance. Relational coordination can play an important role in addressing the issues of coordinating organizational activities due to high level of interdependence complexity in service sector firms. Research has primarily supported the aspect that well devised high performance work systems (HPWS) can intensify organizational performance. There is a growing debate, however, with regard to understanding the “mechanism” linking HPWS and performance outcomes. Using relational coordination theory, this study examines a model that examine the effects of subsets of HPWS, such as motivation, skills and opportunity enhancing HR practices on relational coordination among employees working in reciprocal interdependent job settings. Data were gathered from multiple sources including managers and employees at individual, functional and unit levels to know their understanding in relation to HPWS and relational coordination (RC) in 218 bank branches in Pakistan. Data analysis via structural equation modelling, results suggest that HPWS predicted RC among officers at the unit level. The findings of the study have contributions to both, theory and practice.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1130
Author(s):  
Mariana Pires Figueiredo ◽  
Ana Borrego-Sánchez ◽  
Fátima García-Villén ◽  
Dalila Miele ◽  
Silvia Rossi ◽  
...  

This work presents the development of multifunctional therapeutic membranes based on a high-performance block copolymer scaffold formed by polyether (PE) and polyamide (PA) units (known as PEBA) and layered double hydroxide (LDH) biomaterials, with the aim to study their uses as wound dressings. Two LDH layer compositions were employed containing Mg2+ or Zn2+, Fe3+ and Al3+ cations, intercalated with chloride anions, abbreviated as Mg-Cl or Zn-Cl, or intercalated with naproxenate (NAP) anions, abbreviated as Mg-NAP or Zn-NAP. Membranes were structurally and physically characterized, and the in vitro drug release kinetics and cytotoxicity assessed. PEBA-loading NaNAP salt particles were also prepared for comparison. Intercalated NAP anions improved LDH–polymer interaction, resulting in membranes with greater mechanical performance compared to the polymer only or to the membranes containing the Cl-LDHs. Drug release (in saline solution) was sustained for at least 8 h for all samples and release kinetics could be modulated: a slower, an intermediate and a faster NAP release were observed from membranes containing Zn-NAP, NaNAP and Mg-NAP particles, respectively. In general, cell viability was higher in the presence of Mg-LDH and the membranes presented improved performance in comparison with the powdered samples. PEBA containing Mg-NAP sample stood out among all membranes in all the evaluated aspects, thus being considered a great candidate for application as multifunctional therapeutic dressings.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.


Nanoscale ◽  
2016 ◽  
Vol 8 (5) ◽  
pp. 2857-2866 ◽  
Author(s):  
Matilde Saura-Múzquiz ◽  
Cecilia Granados-Miralles ◽  
Marian Stingaciu ◽  
Espen Drath Bøjesen ◽  
Qiang Li ◽  
...  

High-performance hexaferrite magnets of aligned single-domain nanoplatelets are obtained by supercritical synthesis and compaction through Spark Plasma Sintering.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amir Muhammad Afzal ◽  
In-Gon Bae ◽  
Yushika Aggarwal ◽  
Jaewoo Park ◽  
Hye-Ryeon Jeong ◽  
...  

AbstractHybrid organic–inorganic perovskite materials provide noteworthy compact systems that could offer ground-breaking architectures for dynamic operations and advanced engineering in high-performance energy-harvesting optoelectronic devices. Here, we demonstrate a highly effective self-powered perovskite-based photodiode with an electron-blocking hole-transport layer (NiOx). A high value of responsivity (R = 360 mA W−1) with good detectivity (D = 2.1 × 1011 Jones) and external quantum efficiency (EQE = 76.5%) is achieved due to the excellent interface quality and suppression of the dark current at zero bias voltage owing to the NiOx layer, providing outcomes one order of magnitude higher than values currently in the literature. Meanwhile, the value of R is progressively increased to 428 mA W−1 with D = 3.6 × 1011 Jones and EQE = 77% at a bias voltage of − 1.0 V. With a diode model, we also attained a high value of the built-in potential with the NiOx layer, which is a direct signature of the improvement of the charge-selecting characteristics of the NiOx layer. We also observed fast rise and decay times of approximately 0.9 and 1.8 ms, respectively, at zero bias voltage. Hence, these astonishing results based on the perovskite active layer together with the charge-selective NiOx layer provide a platform on which to realise high-performance self-powered photodiode as well as energy-harvesting devices in the field of optoelectronics.


2020 ◽  
Vol 19 (4) ◽  
pp. 30-42
Author(s):  
A. A. Igolkin ◽  
T. A. Chubenko ◽  
A. D. Maksimov

The problem of developing optimal-design electromagnetic valves is relevant for many industries. The development of technology is characterized by increased power and pressures used for actuator mechanisms, as well as by reducing the dimensions and mass of automatic units. The goal of this article is to develop an advanced electromagnetic valve that would ensure optimal combination of high performance, reliability, technological effectiveness and minimal cost. On the basis of standard dependences for electromagnetic phenomena a mathematic model of a SU.1 valve was developed. It was calculated in several special-purpose software packages: NISA, FEMM, ANSYS Maxwell. Parametric analysis was implemented in ANSYS Maxwell for variable working gap settings and values of current force in the solenoid. As a result, the magnetic induction distribution field was obtained. The results of modeling the operation of the electromagnetic valve and the magnetic induction distribution field are presented for variable working gap settings and different values of current force in the solenoid. The model of an advanced electromagnetic valve for a liquid rocket engine was developed on the basis of the dependences obtained. The duration of single engine firing obtained is 40 msec. The results obtained make it possible to create a valve with hold-open time of 800msec, which is considered sufficient for application in electromagnetic direct current valves.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yinghui Han ◽  
Le Li ◽  
Yunpeng Liu ◽  
Xue Li ◽  
Xiaohan Qi ◽  
...  

A simple and efficient process method for the preparation of strontium bismuth oxides (SBOs) via an impregnation-calcination method is presented. The synthesized active materials are characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical performance of the as-synthesized SBO samples is observed to decrease gradually as the strontium content is increased from 25% to 50%. The SBO sample with a Sr/Bi ratio of 1 : 3 shows the highest specific capacitance of 1228.7 F g−1 (specific capacity of 204.8 mAh g−1) at a current density of 1 A g−1 and a good cycling stability (75.1%) over 3000 charge-discharge cycles. The improved performance of the supercapacitors can be attributed to the unique structural features resulting from the addition of appropriate portions of Sr, which supports high electron conductivity and rapid ion/electron transport within the electrode and at the electrode/electrolyte interface. All the results show that the SBOs have considerable potential for use as high-performance battery-type electrodes in supercapacitors.


2012 ◽  
Vol 2012 (DPC) ◽  
pp. 002285-002315
Author(s):  
Simon McElrea ◽  
Vern Solberg

Effective 3D stacking of DRAM devices can offer many benefits; improved performance, increased component density and greater surface area utilization. To enable the new generations of processors to reach their performance potential many manufacturers have developed more efficient interface formats that enable greater memory bandwidth. This revolution in performance driven electronic systems continues to challenge the IC packaging industry. The challenge is clear. To ensure that the memory functions are able to support the increased signal speed, product developers will need to explore more innovative 3D package assembly techniques and process refinement methodologies. The methodology selected for package assembly, however, must consider process complexity, the costs associated with each process, overall package assembly yield and, from the users perspective, end product reliability. For some applications companies have had limited success in stacking die elements directly onto an interposer substrate using wire-bond processes. High performance DRAM die, however, is especially difficult to stack. This is due to the center positioned wire-bond sites. This factor has complicated the DRAM die stacking process and because of the excessively long wire-bond interface, functional signal speed is significantly degraded. Stacking individually packaged DRAM (package-on-package) has had considerable success but the package outline dimension and package height can be excessive. In this paper the authors will introduce a very innovative and very thin 3D package developed specifically for center-bond pad DRAM die. The package assembly methodology promises to remain economical because it requires no special die level process steps and it can utilize the existing package assembly infrastructure. Additionally, data compiled during extensive performance and reliability modeling will be presented along with the results from actual physical qualification testing.


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