Shield Type Research Articles

Shielding characteristics of a new epoxy resin reinforced by PbO nanoparticles and PbO micro for protection against X-ray and investigation of their cytotoxicity effects and photocatalytic activity

In this research, for the first time, lead oxide nanoparticles (PbO-NPs) were synthesized using Trigonella feonumgraecum plant seeds as a stabilizer and Pb (NO3)2 salt as lead precursor. The results of the XRD pattern displayed the synthesized NPs have an orthorhombic crystalline structure. According to FESEM images, the NPs had a mean size of about 18.62 nm with a spherical morphology. Also, the cytotoxicity of NPs was evaluated on the Hep G2 cancer cell line, and the IC50 value was reported as 267.07 μg/mL. Next, the photocatalytic performance of the synthesized PbO-NPs was investigated for removing methylene orange (MO) pigment under UVA light, which led to the destruction of about 94% after 120 min. Finally, to investigate the protective property of PbO-NPs against X-ray, a polymer nanocomposite of epoxy resin/PbO-NPs was prepared with different weight percentages. In the same way, other samples were also prepared, and then their ability to attenuate X-ray was studied with an X-ray tube with a voltage of 52 kV for the palm and 80 kV for the thigh of an average person, respectively. The measurement results show that with the increasing weight percentage of the fillers, the samples' linear and mass attenuation coefficient increases, which means an increase in the efficiency of the samples in X-ray attenuation. Generally, epoxy resin/PbO-NPs samples show a better effect than other samples. Therefore, these types of shields can attract more attention due to their lightness, cost-effectiveness, and far fewer environmental hazards than common lead shields.

Optimal design of selected features of exhaust system shields using different optimization methods and artificial neural networks

The article presents problems related to methods of optimal design of heat shields used in exhaust systems of internal combustion engines. The optimization method proposed in this paper goes well beyond the scope of the standard design process. The paper uses a variety of local and global optimization algorithms, those both built into numerical simulation systems and in-house and external algorithms. An optimization criterion was defined and numerically implemented, together with constraints derived from the real requirements for this type of shielding. A simplified numerical model of finite element method providing the required accuracy adapted to the optimization task was developed. In addition, the work also presents a method for creating finite element surrogate models using artificial neural networks. The process of selecting the network topology and its learning allowed the development of a metamodel characterized by very good quality, for which, despite the relatively large number of design variables, the response errors are completely acceptable from a practical point of view. Numerical results were compared and developed for the used methods and algorithms.

Evaluation of shielding performance and light emission characteristics of luminescent radiation shields using Gd2O2S

ABSTRACT Gadolinium oxysulfide (Gd2O2S: GOS) has a large absorption cross-section for thermal neutrons and a mass density similar to that of iron used for shielding against X and γ-ray radiation. During GOS scintillator production process, its waste is also generated. If GOS waste can be used as an effective shielding material, it is worthwhile as beneficial use of the waste. We developed a novel radiation-shielding material using GOS waste. The developed shielding material can shield X, γ-rays and thermal neutrons more efficiently than conventional shielding materials and emit visible light due to leaked radiation when the shielding material is damaged, which subsequently be used to check the integrity of shielding using visible light. In this study, two types of shields, concrete and mortar with GOS as the aggregate and epoxy resin with GOS were prototyped and tested for radiation transmission. Results indicate that GOS shielding has a 10% higher shielding ability for X and γ-rays than heavy concrete with iron as aggregate. Additionally, the same shielding effect for thermal neutrons was attained at 1/10 the thickness of heavy concrete. Thus, using GOS waste is not only cost effective but also contributes to a circular economy.

ИКОНОГРАФИЯ ЩИТОВ РИМСКИХ ЛЕГИОНЕРОВ ПОСЛЕДНЕЙ ТРЕТИ II В.: НА МАТЕРИАЛЕ РЕЛЬЕФОВ КОЛОННЫ МАРКА АВРЕЛИЯ

The article considers the reliefs with the Roman legionnaires’ images on the Column of Marcus Aurelius as a source on the Roman weaponry and military tactics of the last third of the 2nd century AD. Traditionally in historiography, those images are not considered sufficiently representative due to the large number of the borrowings from other monuments of the Roman triumphal art. By analyzing the images of various legionary shields on the Marcus Aurelius Column and comparing them with other monuments of the Roman art of the last third of the 2nd – early 3d centuries AD, there were similarities found between them in representing the elements of the Roman military equipment. The Column images prove the use by the legionnaires of at least four types of shields with various shapes. It is also assumed that Roman soldiers could have used the shields of different shapes and types even within the same formation or the formation without any reference to a particular line of formation construction. In general, the reliefs of the column make it possible to challenge the conventional wisdom of the uniform armament of the Roman legions during the period of the Principate. Thus, the reliefs of the Column of Marcus Aurelius can be considered a valuable source on the military affairs of the early Empire era.

Reduction of Radiation Risk to Cardiologists and Patients during Coronary Angiography: Effect of Exposure Angulation and Composite Shields

Purpose: This study aimed to design an improved form of a composite shield with different materials and shapes and simultaneously reduce the radiation dose to both the patient and operator.
 Materials and Methods: A female phantom study was performed with and without bismuth belt-shaped composite shields on the breast region at different beam projections used in coronary angiography. Dose measurements were conducted using GR-200 thermo-luminescence dosimeters, dose area product (DAP), and air kerma (AK) over regular and large breast locations, with and without using bismuth shields. An electronic personal dosimeter was used for operator dose assessment. Patients received doses between 2.27 mSv and 3.38 mSv, depending on the size and strength of beam projections.
 Results: The use of the developed shields caused a dose reduction of 18%–25% of sensitive breast tissue due to breast size and shield type. During coronary angiography, the mean values of DAP and AK were 2.02 (1.24-2.80) mGy.m2 and 314.1 (202.8-500) mGy, respectively. The highest recorded dose was at the LAO/CRA and LAO/CAU beam projections for both the patient and operator. After applying a belt shield, the operator's radiation dose was decreased by approximately 32%. We found a statistically significant correlation between the radiation dose received by the operator and the patient's breast radiation exposure dose (p<0.001, r2=0.93).
 Conclusion: The designed belt shield can be a potentially promising protective device for decreasing the radiation risk to the patient's breast and the operator during coronary angiography. However, further studies will be considered before the application of this shield in standard clinical practice.

Identification of DSPP novel variants and phenotype analysis in dentinogenesis dysplasia Shields type II patients.

To investigate the genetic causes and teeth characteristics of dentin dysplasia Shields type II(DD-II) in three Chinese families. Data from three Chinese families affected with DD-II were collected. Whole-exome sequencing (WES) and whole-genome sequencing (WGS) were conducted to screen for variations, and Sanger sequencing was used to verify mutation sites. The physical and chemical characteristics of the affected teeth including tooth structure, hardness, mineral content, and ultrastructure were investigated. A novel frameshift deletion mutation c.1871_1874del(p.Ser624fs) in DSPP was found in families A and B, while no pathogenic mutation was found in family C. The affected teeth's pulp cavities were obliterated, and the root canals were smaller than normal teeth and irregularly distributed comprising a network. The patients' teeth also had reduced dentin hardness and highly irregular dentinal tubules. The Mg content of the teeth was significantly lower than that of the controls, but the Na content was obviously higher than that of the controls. A novel frameshift deletion mutation, c.1871_1874del (p.Ser624fs), in the DPP region of the DSPP gene causes DD-II. The DD-II teeth demonstrated compromised mechanical properties and changed ultrastructure, suggesting an impaired function of DPP. Our findings expand the mutational spectrum of the DSPP gene and strengthen the understanding of clinical phenotypes related to the frameshift deletion in the DPP region of the DSPP gene. A DSPP mutation can alter the characteristics of the affected teeth, including tooth structure, hardness, mineral content, and ultrastructure.

Determination of Shielding Effectiveness of a Subnanosecond High-Power EM Interference by an Enclosure with Aperture Using Time Domain Approach

Determination of Shielding Effectiveness of a Subnanosecond High-Power EM Interference by an Enclosure with Aperture Using Time Domain Approach

Elaboration of X-ray shielding of highly barite-loaded polyester concrete: structure, mechanical properties, and MCNP simulation

Various research has been done in manufacturing and designing different types of radiation shielding. In this study, lead-free polymer composite panels with new special formulations have been prepared and characterized to prevent radiation leakage in medical facilities at the diagnostic energy range (60 – 120 keV). Polyester resin is used as a binder along with large amounts of mineral barium sulfate (barite) aggregate (more than 70 % by weight). SEM micrographs showed a homogeneous distribution of barite particles. Then the effects of adding barite on the physical, mechanical, and thermal properties of composite panels were investigated. The results showed that increasing the percentage of barite powder in the formulation, with the high wetting capability of polyester resin, improved physical and mechanical properties. The composite panel containing 80 wt% of barite had the highest tensile and flexure strength. Also the thermal stability of the composite panel containing 90 wt% of barite was 40 °C to 50 °C more than other samples. The samples' mass attenuation coefficient (μm) was calculated experimentally and theoretically using MCNP-5 simulation software and the XCOM program. Experimental and calculated results have been compared and were found to be in reasonable agreement. In general, with increasing barite content, the composite shielding panel became denser and μ increased while HVL and TVL values decreased. In addition, the studied shields were superior to lead by virtue of their non-toxic nature and will be a radiation shielding solution in making wall panels.

The Association of Radiation Exposure with Stable Chromosome Aberrations in Atomic Bomb Survivors Based on DS02R1 Dosimetry and FISH Methods.

The frequency of stable chromosome aberrations (sCA) in lymphocytes is a recognized radiation biological dosimeter. Its analysis can provide insights into factors that affect individual susceptibility as well as into the adequacy of radiation dose estimates used in studies of atomic bomb survivors. We analyzed the relationship between atomic bomb radiation exposure using the most recent DS02R1 dose estimates and the frequency of sCA as determined by FISH in 1,868 atomic bomb survivors. We investigated factors that may affect the background sCA rate and the shape and magnitude of the dose response. As in previous analyses of sCA in atomic bomb survivors that were based on Giemsa staining methods and used older DS86 dose estimates, the relationship between radiation dose and sCA rate was significant (P < 0.0001) with a linear-quadratic relationship at lower doses that did not persist at higher doses. As before, age at the time of the bombing and type of radiation shielding were significant dose-effect modifiers (P < 0.0001), but in contrast the difference in dose response by city was not so pronounced (P = 0.026) with a city effect not evident at doses below 1.25Gy. Background sCA rate increased with age at the time of examination (P < 0.0001), but neither sex, city, nor smoking was significantly associated with background rate. Based on FISH methods and recent dosimetry, the relationship between radiation dose and sCA frequency is largely consistent with previous findings, although the lesser importance of city as an effect modifier may reflect better dosimetry as well as more reproducible scoring of sCA. The persisting difference in sCA dose response by shielding category points to remaining problems with the accuracy or precision of radiation dose estimates in some A-bomb survivors.

Recent progress on multifunctional electromagnetic interference shielding polymer composites

• The review discusses the basic theory, attenuation mechanisms and characterization methods of electromagnetic interference (EMI) shielding. • The recent progress of multifunctional EMI shielding polymer composites are summarized and discussed with respect to their structures, fabrication methods and specific functions. • The critical scientific and technical issues for EMI shielding composites with different functions are proposed, and the main challenges in the development of multifunctional polymer-based EMI shielding materials are presented. The explosive development of electronic devices and wireless communication technology gives rise to the issue of electromagnetic pollution, known as electromagnetic interference (EMI). The accumulation of undesirable electromagnetic radiation in space disturbs the normal function of unshielded electronic appliances and poses seriously threat to human health. Thus, the development of EMI shielding materials have emerged to solve the grim problem. Considering the complex application contexts, EMI shielding materials have evolved from traditional single-function to multi-functions to meet the ever-increasing application requirements in recent few years. This paper provides detailed insight into the current research status and future challenges in the advancement of polymer-based EMI shielding materials with various functions. First, the basic theory of EMI shielding, factors influencing results and the dominating characterization technologies for EMI shielding properties are summarized. Then, the comprehensive descriptions of the seven types of multifunctional EMI shields are provided with respect to their structures, fabrication methods and specific functions. Meanwhile, the corresponding critical scientific and technical issues are proposed. Based on our comprehensive analysis, the main challenges in the development of multifunctional EMI shielding materials are presented. This review aims to provide some guidance and inspire more efforts toward functional EMI shielding material research to satisfy the growing requirements for next-generation electronic systems.

Construction solutions and calculation methods of horizontal protective shields for tunnel-type structures

The article considers features of creating horizontal protective shields made of steel pipes for construction of tunnel-type structures in a closed manner. Types of horizontal protective shields and methods of their construction are analyzed. Variants of modern tunnel structures arranged in difficult geological conditions with the use of lining from large diameter pipes along the perimeter of the entire structure are given. Factors influencing the choice of a rational shield shape and an appropriate design model for solving the problem of the stress-strain state of the soil body weakened by a horizontal cavity of a closed type are taken into account, considering various options for propping and external influence on the soil body under studyThe obtained value of settlement of the upper layer of the support also depends on the dynamic loads from the railway tracks, but does not take into account the sequence of the technological process of construction of an underground tunnel, which is a guideline for subsequent projects.

Towards obtaining the optimum physical, optical and nuclear radiation attenuation behaviours of tellurite–germanate glasses through Eu2O3 reinforcement: Glass synthesis, experimental and theoretical characterisation study

We report the physical, optical and nuclear radiation attenuation behaviours of tellurite–germanate (TeO2–GeO2–PbO) glasses reinforced with varying amounts of Eu2O3. The samples were synthesised using the conventional melt-quenching method and had the following composition (in wt.%): 33.34TeO2 - 33.33GeO2 - 33.33PbO (TGP). Different concentrations of Eu2O3 (in wt.%) were added to the glass composition, labelled TGP1, TGP2 and TGP3. The physical, optical and nuclear radiation attenuation properties were measured using both experimental and theoretical methods. At room temperature, the visible to near-infrared optical absorption spectrum ranged from 400 to 900 nm. The TGP1 sample with 1 wt% The Eu2O3 additive exhibited the lowest absorbance and the highest transparency. The TGP1 sample also exhibited the highest nuclear radiation absorption properties. The gamma-ray absorption capabilities of TGP1 were demonstrably superior to those of various types of glass shields and other old- and new-generation concrete-shielding materials. Thus, adding 1 wt% Eu2O3 to tellurite–germanate glasses would ‘improve nuclear radiation absorption and optical properties. It can also be concluded that expanded scientific community investigations in this area would be a significant step toward gaining a deeper understanding of these glass structures and determining what other optimisation tasks the addition of 1 wt% Eu2O3 can accomplish.

Coil Parameter Analysis in Wireless Electric Vehicle Charging

The hassle of using plug-in charging for electric vehicles (EVs) such as connecting charger to the port of vehicles, risk of getting electrocuted during rain, dirty and oily charging cable etc. can be eliminated using wireless/induction power transfer (IPT). It can be made smart and automated. Hence, IPT can be considered the future of EV charging. However, the technology is just emerging and there are a lot of limitations at present. The major problems are less efficiency caused by coil misalignment and air gap, and the electro-magnetic field generated around the coils which possesses greater risk for human health. These can be improved by selecting the types of coils and shields which produce maximum magnetic flux between the coils whereas reduce the flux outside the coils. In this research, the strength of magnetic fields produced by various types of coils (circular, square and hexagonal) were simulated in Ansys Maxwell 3D to understand their features and to know which coil is the best for high power transfer efficiency. Similarly, the effects of using ferrite and aluminum shields for leakage reduction, by varying their thickness, were studied. Finally, the leakage flux values were simulated at very high currents to understand their behavior in such conditions.

Study the Gamma Ray Attenuation of 60Co in the Polyester Composite_Calcium Ferrite Powder Supported Shields

This study included the production of composite materials shields of polyester fortified by Calcium Ferrite powder prepared by two different temperature degrees of annealing (800co and 1000co) to get the various size of the used granular powder.Geiger counter tube system used to study of the susceptibility of these shields on gamma radiation attenuation that emitted from the 60Co, were five types of nuclear shielding was prepared, two of them the powder annealed at temperatures 800co different concentrations of the proportion of the addition are 2% and 7% were used in, and the other two the powder annealed at 1000co and with the same concentrations above, the latter type is the pure polyester shield without any addition. The results showed that the linear attenuation coefficient μ increases and transmission coefficient T.F decreases with reinforcement powder concentration increasing in the sample and the granular size of the reinforcement powder increasing , and the relationship between the transmission factor the thickness of the shield X is an inverse, results also showed that the half values layer HVL and tenth value layer values TVL decrease with increasing of reinforcement powder concentration in the polymer and increasing of the granular powder size. The best results were achieved using a shield composite fortified by calcium Ferrite powder that annealed at 1000co with a concentration of 7%, indicating that the best.

DEICTIC MITIGATION VS COMMISSIVE ACTS IN POLITICAL INTERVIEW (BASED ON THE MODERN EUROPEAN DISCOURSE OF AID TO UKRAINE)

The article deals with the problem of correlation between the illocutionary force of indirect commissive acts and shields as deictic mitigating markers that reduce the level of promises by influencing their felicity conditions. The purpose of the article is to clarify the types of deictic shields and their function in weakening the illocutionary force of indirect promises in the European political discourse of assistance to Ukraine. The purpose is achieved by solving the following objectives that determine the research algorithm, including (a) felicity conditions revealing for commissives, weakened by shields that affect the illocutionary force of acts; (b) identifying those deictic coordinates of statements, the reference to which weakens the illocutionary force of commissives; (c) lexical-semantic and syntactic deictic mitigators complex determination. To achieve the purpose and objectives set in the article, the following research methods are used: the method of speech acts analysis and the method of inferencing the shields-based conventional implicatures, supplemented by elements of componential analysis. The article reached the following principal results. Firstly, among the felicity conditions for commissives weakened by shields, the article highlights the condition of speaker’s sincerity and the preparatory condition of his / her ability to perform a promissive act. Due to the shields, the promise is transferred from the scope of the action to the scope of the speaker’s possibilities. Secondly, based on the understanding of shields as the markers affecting either the speaker’s / addresser’s face-protecting attitude to the proposition or the deictic space-temporal-object coordinates of the utterance, the paper has identified that the illocutionary force of indirect commissives is mitigated by personal, temporal and object shields. Thirdly, we have singled out and specified a set of illocution-mitigating deictic devices, including means of role-playing deixis, epistemological modal verbs and their substitutes, which denote or connotate semes of “capabilities” and “possibilities”, means of negation, temporary deixis devices, i.e. the lexical and grammatical markers of future tense, resulting in the vagueness of promises / obligations; presuppositional adverbs with inference pattern of “impediment to a promised action”; passive structures that withdraw the speaker from the position of phrasal subject and an agent of the promising action; verbs and adverbs, which in their inference patterns contain the denotative or contextually connotated semes of a temporal reference to an indefinite future; metonymic generalization of the agent of action. The prospect for further research is the analysis of all types of mitigators, including bushes, hedges and shields, in their projection on rhetorical and manipulative methods of argumentation in political discourse as manifested by the discourse-forming concept “Caution”.

Shielding effectiveness of different polymers and low-density hydrides in a combined radiation shield for crewed interplanetary space missions

Exposure to Galactic cosmic rays (GCR) and solar particle events (SPE) has been identified as one of the critical barriers for long term space missions that impose both immediate and delayed health hazards on the astronauts. There are two types of protective shields available namely active and passive shields, and combining these two shields can be a useful strategy. The study aims to present the effectiveness of a combined radiation shield containing an active toroidal shield with a layer of passive shield made of different polymers or low-density hydrides. The active shield is capable of deflecting protons (Z < 1) with energies below 700 MeV/n and for Alpha, and Fe ions (Z > 1) it can deflect up to 200 MeV/n and 175MeV/n respectively. The shielding effectiveness of polymers and hydrides with different thicknesses was investigated with Monte Carlo simulations performed by means of Geant4/MULASSIS. The shielding properties were studied using proton, alpha, and Fe ions with energies of 1 GeV/n. Nuclear stopping power and Fast Neutron Removal Cross Section (FNRCS) were calculated using SRIM and PHY-X/PSD. For the 20 gm/cm2 thick layer made of polymers, the reduction of dose equivalent for proton, alpha, and Fe ion of 1GeV/n are 5.44%, 54.34%, and 63.76% respectively and in the case of Low-density Hydrides with the same dimension, the rates are 4.12%, 55.3%, and 76.88%. Low-density hydrides demonstrated better radiation shielding capability than the polymers. The results are compared with OLTARIS for GCR spectra of 2010 solar minimum. The downsides of this type of shield are also briefly covered.

Wiener–Hopf factorization indices of rational matrix functions with respect to the unit circle in terms of realization

As in the paper Groenewald et al. (2017) our aim is to obtain explicitly the Wiener–Hopf indices of a rational m×m matrix function R(z) that has no poles and no zeros on the unit circle T but, in contrast with Groenewald et al. (2017), the function R(z) is not required to be unitary on the unit circle. On the other hand, using a Douglas–Shapiro–Shields type of factorization, we show that R(z) factors as R(z)=Ξ(z)Ψ(z), where Ξ(z) and Ψ(z) are rational m×m matrix functions, Ξ(z) is unitary on the unit circle and Ψ(z) is an invertible outer function. Furthermore, the fact that Ξ(z) is unitary on the unit circle allows us to factor as Ξ(z)=V(z)W∗(z) where V(z) and W(z) are rational bi-inner m×m matrix functions. The latter allows us to solve the Wiener–Hopf indices problem. To derive explicit formulas for the functions V(z) and W(z) requires additional realization properties of the function Ξ(z) which are given in the last two sections.

Medieval Shields of Europe and Rus’ (Construction, Military Symbolic Significance, Development)

The article considers the problem of the development of shields, the main element of medieval protective equipment, and an important military and heraldic symbol in Ukrainian medieval state of Rus’ and in Europe in general. The state of the research and the source base are outlined. The main trends in the development of the design and symbolic significance of shields in Europe during the Middle Ages are outlined. At the same time, emphasis was placed on sources concerning Rus’ lands and adjacent territories. The author draws attention to the need to compare archaeological, written and iconographic sources in one study. The study focuses on the most representative sources, especially those that can be to apply on material from the Rus’ lands. It is emphasized that the shield as a basic element of protective equipment during the Middle Ages, іn Rus’ lands largely developed in line with European trends. Which in turn makes it impossible to isolate local features about to beginning of the ХІІІ century. At the turn of the XII–XIII centuries in some regions of Eastern Europe, namely the Rus’-Baltic-Polish border, a relatively new type of shield is being formed, the so-called “protopaveza”. This in turn had a direct impact on the armaments of Rus’ and the Teutonic Order in the ХІІІ–ХІV centuries. The author analyzes the main interactions and borrowings of types of shields between different regions of Eastern Europe during the Middle Ages. It is noted that in the Ukrainian medieval state of Rus’, which was at the intersection of Eastern and Western military traditions, shields of both European types and the eastern “kalkan” could be used. However, given the available sources, it is safe to say that the European trend of development of this protective equipment had an advantage. The author came to the conclusion that the shields used in Rus’ and Europe in the X–XII centuries generally belonged to the same types. In particular, it is round, almond-shaped and triangular shields. The issue of shields of the XIII–XV centuries remains more complicated. During this period can be observed as the influence of Western Europe on Rus’, for example, the spread of the knight's “tarch”. And trends that began in Eastern Europe, namely the spread of pavises in the XIV–XV centuries.

Fabrication, optical, structural, and gamma-ray attenuation properties of novel slag-waste glasses as superior shields: An exploring journey for waste to glass transformation

We present a comprehensive study on the transformation of municipal slug wastes into glass samples with exceptional gamma-ray attenuation capabilities that may be used in medical and industrial radiation applications to the benefit of society. The whole process is performed using an adsorbent developed by loading iron oxide and TiO2 on municipal solid waste melted slag. The loading is carried out through chemical reactions and high-temperature process. The oxidation of arsenite with a concentration of 100 mg L−1 is completed in 3 h. Next, the glass synthesis process is performed using well-known melt-quenching method. Structural, optical, and gamma-ray attenuation properties are determined using experimental and theoretical methods. Our findings showed that a wide hump centered at 2θ= 30° with no indication of any precise peaks emerging in the crystalline phases and glasses under investigation have amorphous natures. Using several well-known radioisotope energies, the half-value layers of slow waste glasses are determined. The 11-G sample demonstrated the greatest gamma-ray attenuation characteristics among the manufactured glass samples. The 11-G sample's half layer values are then compared to those of comparable glass, concrete, and polymer shields available in the literature. The results demonstrated that 11-G is clearly better than the other shield types. It can be concluded that some other novel materials with superior shielding properties may be manufactured using more thoroughly separating techniques in terms of determining the best conditions for this type of superior materials. It can be also concluded that some other characterization phases may be conducted in terms of identifying the undiscovered properties of the current samples towards better understanding of slug-waste based glasses and their potential applications.

RELATIONSHIPS BETWEEN TYPES OF PROTECTIVE EYEWEAR AND EYE LENS DOSE WITHIN ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY.

In this study, variations in eye lens dose across different types of protective operator eyewear as well as the most appropriate protective methods when conducting endoscopic retrograde cholangiopancreatography were evaluated. The eye lens doses of 10 types of commercially available protective eyewear were compared. The ratio of the measured value near the eye to the measured value at the eye lens position ranged from 0.65 to 5.40 and it varied according to the mounting position of the dosemeter as well as the type of protective eyewear. Thus, the eye lens dose may have been overestimated or underestimated. Regardless of the working conditions, a face shield type of protective eyewear is recommended to reduce the eye lens dose. Moreover, it is preferable to attach a lens dosemeter near the eye to measure and evaluate the eye lens dose.