Mixture Of Pellets Research Articles

Effect of particle size distribution on the thermal conductivity of crushed GMZ bentonite pellet mixtures

Effect of particle size distribution on the thermal conductivity of crushed GMZ bentonite pellet mixtures

Mechanical properties of teguline clay pellet mixtures during continuous oedometric compression

Clay pellet mixtures are generally compressed to improve their engineering performance. Deepening the comprehension of the mechanical properties of these mixtures in the complete compression process facilitates the benefit to the engineering design and their utilization. In this study, the effects of soil grain size distribution, water content and dry density on the mechanical properties and microstructure of Teguline clay pellet mixtures during a continuous oedometric compression process are explored. Three types of soil pellet mixtures, including mixture A (grain size ≤5 mm), mixture B (≤ 0.4 mm) and mixture C (2–5 mm), were prepared with different water contents of 7%, 8% and 12% respectively. Subsequently, continuous oedometeric compression was undertaken to explore their mechanical behaviours of the soil pellet mixtures. After that, the microstropic structures of the compacted pellet mixtures were investigated using mercury intrusion porosimetry (MIP). The results indicated that mixture A has a minimal initial packing density of pellet mixtures, while mixture C has a maximum one at the initial compression stage. After completion of compression, the compression curves of the pellet mixtures tended to converge uniformity at a semilogarithm coordinate as the vertical stress increased. All of the compression curves presented a concave shape at the plastic compression stage, which is significantly influenced by grain size distribution and water content. In contrast, the elastic compression and rebound behaviours are little affected by the grain size distribution and water content. As far as the microstructure is concerned, compacted samples prepared by mixture A or C presented a unimodal pore structure, while those by mixture B showcased a bimodal pore structure. In comparison with the unimodal pore distribution of the undisturbed stiff clay, the compacted samples displayed a pseudo-unimodal pore distribution because the inter-aggregate pores still existed. A double tangent method was proposed to determine the delimiting pore diameter of the pseudo-unimodal pore distribution curves and found that the delimiting pore diameter decreased with the increase of dry density and water content. Moreover, the inflexion point for the pore diameter of compacted samples prepared by coarse soil was larger than that of fine soil. Combining this work with previous research, it was found that the high compression of coarse soil easily causes the pseudo-unimodal shape, which is also impacted by water content and particle properties. This work could help deepen the understanding of the mechanical characteristics and microstructure of the stiff clay pellet mixtures during continuous oedometric compression.

The Effect of Binders on the Quality of Fermented Poultry Manure Pellets as Unconventional Feed

Poultry manure has the potential to be used as a feed ingredient because it has a high enough protein and amino acid with less growth of patoghenic microorganism. The improvement of poultry manure as pellet can help to increase the palatability and feed storaging. This study aimed to determine the influence of different binders on the chemical and physical attributes of pellets derived from fermented poultry manure. Three binders, namely tapioca flour (T1), wheat flour (T2), and cassava flour (T3), were utilized in the fermentation process, with the fermented poultry manure. A 10% binder was added into the mixture, which was subsequently processed using a pelletizer. Each treatment was replicated three times, with each replication requiring 1500 g of the pellet mixture. Laboratory analyses were conducted to evaluate chemical quality through proximate analysis and gross energy assessment, while physical quality analyses included physical characteristics, measurements of diameter, length, and density, stacking density, stack compaction density, pellet durability index (PDI), modulus of uniformity, modulus of fineness, buoyancy, and water resistance. The results indicated that variations in binders did not yield numerically differences in dry matter content, organic matter, crude fat, crude fiber, and gross energy. Notably, pellets containing a wheat flour binder exhibited the highest crude protein content numerically. Furthermore, influenced the buoyancy test, with wheat flour binder showing the best buoyancy. This study recommends the adoption of wheat flour as a binder in the production of pellets based on fermented poultry manure.

Grinding of Australian and Brazilian Iron Ore Fines for Low-Carbon Production of High-Quality Oxidised Pellets

Oxidised pellets have become an indispensable high-quality charge for blast furnaces. Nevertheless, high-quality pellet feeds are becoming scarcer and scarcer. To broaden the range of sources of pellet feeds and reduce the production cost of pellets, more steel mills are predicted to use coarse iron ore fines with a relatively low iron grade and low impurities for the preparation of desirable pellet feeds through a typical wet grinding–settling–filtering process. In this work, the grinding, settling and filtering behaviour of Brazilian and Australian iron ore fines are studied and compared, with the aim of discovering the internal relationship between the mineralogical characteristics of different iron ore types and their grinding–settling–filtering performance. Additionally, the effects of ore blending on pellet preparation were investigated. The results show that, usually, the higher the hardness of the iron ore, the more grinding energy is required. Australian and Brazilian ore fines exhibit good grindability, with a Bond work index of about 10–15 kW·h/t. Furthermore, ore blending can reduce grinding energy consumption and improve settling and filtration rates, and the addition of finely ground Australian ores improves the balling performance of pellet mixtures. At the same bentonite content, the ball drop strength of the three blends with added Australian ore is significantly higher than that of the base blend, and the fired pellets obtained from Blend 1, Blend 2 and Blend 3 blends exhibit good metallurgical properties.

Cushion-coated pellets for tableting without external excipients

Multiple-unit dosage forms prepared by compacting pellets offer important manufacturing and compliance advantages over pellet-filled capsules. However, compaction may negatively affect the release control mechanism of pellets, and subunits may not be readily available after intake. Application of a cushioning layer to the starting units is here proposed as a strategy to obtain tablets with satisfactory mechanical strength, rapid disintegration and maintenance of the expected release profile of individual subunits while avoiding the use of mixtures of pellets and excipients to promote compaction and limit the impact of the forces involved. Cushion-coating with PEG1500, a soft and soluble material, was proved feasible provided that the processing temperature was adequately controlled. Cushioned gastro-resistant pellets were shown to consolidate under relatively low compaction pressures, which preserved their inherent release performance after tablet disintegration. Adhesion problems associated with the use of PEG1500 were overcome by applying an outer Kollicoat® IR film. Through design of experiment (DoE), robustness of the proposed approach was demonstrated, and the formulation as well as tableting conditions were optimized. The tableted cushion-coated pellet systems manufactured would allow a relatively high load of modified-release units to be conveyed, thus setting out a versatile and scalable approach to oral administration of multiple-unit dosage forms.

Effect of granular structure and initial suction on shear strength of GMZ bentonite for deep geological disposal

Granular bentonites have recently attracted increasing attention to serve as buffering/backfilling material alternatives in deep geological repository for disposing high-level radioactive waste (HLRW). In this paper, GMZ bentonite was prepared in the forms of compacted powder (CP), powder/pellet mixture (PPM) and pellet mixture (PM), and a series of direct shear tests, compression tests, soil-water retention tests and microstructural observation were conducted. Results show that the water retention capacity is independent of granular structure and dry density at suction s > 10 MPa. Below this suction, variation in water content should be related to the difference in microstructure. As s decreased, the specimen became more compressible and its shear resistance decreased while showing unimportant changes at s > 100 MPa. Besides, differences in compression and shear behavior between three types of specimens became gradually less obvious with decreasing suction. This indicates that wetting-induced comparable fabric could gradually cause similar compression and shearing response. Both high-density pellets and gradation are considered to affect the internal friction mode and mechanical interlocking phenomenon, so that the peak shear strength and relevant parameters varied. The unified effective stress equation considering both capillary and adsorptive mechanisms was used to predict the peak shear strength, and the predicted values agreed well with test data mostly for the high suction range. The results and ideas obtained in this study are conceived to provide helpful reference for material selection and assessment of bentonite barriers for deep geological disposal.

Effect of torrefaction on fuel properties of biopellets

The study aimed to determine the effects of torrefaction on the fuel properties of pellets. Therefore, firstly, torrefaction parameters of rose (Rosa Damascena Mill.) oil distillation solid waste and red pine sawdust were determined through the torrefaction optimization process in terms of temperature and holding time. Then, using the selected torrefaction parameters, 14 different raw and torrefied pellets containing RP, PS, and Turkish Elbistan Lignite were prepared in different weight ratios. Finally, the fuel properties of the prepared raw and torrefied pellets, namely dimensions, proximate analyses, higher heating values, tensile strength, durability, abrasive resistance, and water uptake resistances, were investigated. The findings demonstrated that the higher heating values and carbon content of raw biomass samples increased while their volatile matter content decreased. The use of lignite at high concentrations led to an increase in ash content and a decrease in the strength and durability of pellets, which should be emphasized. In addition, red pine sawdust was used in place of solid waste from rose oil distillation solid waste to produce pellets with greater strength. All pellet mixtures with torrefaction had higher heating values and energy densities despite the fact that their mass and energy efficiency had decreased. It was determined that torrefaction increased the pellets' resistance to absorbing water and gave them a more hydrophobic structure. Thus, it was determined that torrefaction could enhance the crucial fuel parameters of the biomass samples.

CONVERSION OF CARBON-CONTAINING RAW MATERIAL USING PLASMA TECHNOLOGIES

The state of development of plasma gasification technologies of carbon-containing raw materials in Ukraine is analyzed. It is shown that despite some pessimistic domestic assessments of the prospects for their development, the state of research and development in this field at the global level indicates the inevitable breakthrough directions for the development of such technologies and, first of all, in the field of hydrogen energy. In particular, this concerns the prospects of using such difficult-to-process raw materials for hydrogen production as, for example, sewage sludge or worn automobile tires. This will create an additional powerful effect from their implementation, bearing in mind the solution of complex environmental problems of modern Ukraine. The experimental part of this work is devoted to the study of the prospects of such processing, using the example of a laboratory version of a plasma chemical reactor, made according to the scheme of the process of inverted gasification of solid organic raw materials with the introduction of a plasma jet into the pyrolysis zone. The output of hydrogen depended on the raw material: the lowest one was from sewage sludge pellets, and the highest one was from rubber crumb of worn automobile tires; in the case of gasification of a mixture of sewage sludge pellets and rubber crumb, an intermediate value of this indicator was observed. It is important that the output of hydrogen was determined not so much by its content in the raw material, but by the reactivity of the latter, which also corresponded to the degree of use of water vapor. The level of reactivity determined the degree of use of water vapor in the case of pellets up to 29 %, and rubber crumb up to 56 % and, accordingly, the chemical efficiency of gasification reached 39 % and 55 %. It follows from the results of the research that in the conditions of relatively low temperatures in the experimental reactor, the mixing of pellets of sewage sludge and rubber crumb does not create a synergistic effect of advantages regarding the energy efficiency of the process. Bibl. 58, Fig. 4, Tab. 4.

Holothurians play an important role in mitigating the impacts of aquaculture on sediment conditions

As deposit feeders contribute to bioremediation and nutrient recycling in sediments, positively impacting water and sediment quality, holothurians are candidate organisms for multitrophic aquaculture. This study aimed to investigate the potential of Holothuria poli to reduce the environmental footprint of fish farms through a benthocosm experiment. The experimental setup included four benthocosms with holothurians(H+) and four without (H-). The 58-day experiment included two phases: constant organic enrichment and recovery. In order to simulate the organic enrichment sediment conditions under a typical fish farm, a mixture of fish feces and fish feed pellets was added. Results showed that holothurians effectively reduced organic matter and H2S and increased redox, RPD depth and sediment oxygenation, thereby preventing anoxic conditions. Also, during the recovery phase, holothurians facilitated rapid sediment recovery, while the sediments without holothurians remained organic-enriched until the end of the experiment. The study emphasizes the significance of holothurians in mitigating the impacts of aquaculture on sediment conditions and so promoting environmental sustainability.

Modelling in the frame of hydro-mechanical infiltration column experi-ment to study the behaviour of binary mixtures of bentonite MX80

Binary mixtures of high-density MX80 bentonite pellets (80% mass ratio at a dry density of 2.0 Mg/m3) and powder (dry density of 1.1 Mg/m3) at hygroscopic water contents are studied by the French Institute of Radiation Protection and Nuclear Safety (IRSN) as an alternative in engineered barrier systems for the long-term disposal of radioactive wastes. The MX80 bentonite was studied by many authors [1–4] with this aim. These mixtures show a dry density around 1.49 Mg/m3 on pouring into infiltration column experiment tests.
 An infiltration column cell (100 mm in diameter and 350 mm high) has been developed at a reduced scale of 1/100 of the VSS (i.e., at 1/10 of the in situ VSEAL test) to reproduce asymmetric hydration using independent top (fast injection) and radial (slow injection) water pressure systems, which will undergo fast hydration from the calcareous Oxfordian formation at the top and a slower one by water reaching radially through the Callovo-Oxfordian formation. It also allows performing gas injections at different locations of the core of the bentonite mixture (top and bottom boundaries) and under various hydraulic states. The infiltration column is composed of four transparent cylinders, made of Perspex to visualise processes occurring at the interface during the hydration and gas injection phases (Figure 1a). This cell has been assembled with three stainless-steel injection rings that ensure slow radial water injection through three independent automatic pressure/volume controllers. These stainless-steel injection rings also hold the different lateral transducers (six total stress cells and three water pressure transducers embedded in the soil and three relative humidity probes installed in small dismountable chambers) (Figure 1a). The assembled cell is inserted into a rigid frame composed of two stainless steel disks on the two sides of the cylinder connected by four metallic rods.
 A numerical model has been developed to better understand the coupled hydro-mechanical response of this multi-porosity mixture and particularly of its constitiuents upon hydration.The characterisation of pellet and powder components have been focused on their water retention properties, water permeability, compressibility on loading and on suction changes, as well as on their swelling pressure response and the progressive changes of their pore size distribution on wetting. This information at component scale has allowed the upscaling into a 2D plane-strain numerical model based on the discretisation of pellets and inter-pellet powder using Code_Bright FEM [5]. This plane-strain model captures the pellet shape effect without changing the geometry of the pellets.The geometry used in the simulations corresponds to an infiltration column at constant volume mimicking the actual asymmetric hydraulic conditions of the VSS. Figure 2b presents the geometry of the model used at constant volume based on the discretisation of pellets and powder (252 pellets of 8 mm diameter and surrounded by powder filling the entire inter-pellet volume).The generated numerical mixture has a mass-basis proportion of 77.6% pellets and 22.5% powder, which is close to the mixture proportion. Figure 1b shows the three lateral slow-rate hydration boundaries, as well as the fast-rate hydration boundary at the top. The modelling has focused on analysing the global and particularly the local responses: water mass transfer between powder and pellets, evolution of local degrees of saturation and porosities (inside pellets and powder), and mean stress evolution in the pellet and powder domains. Water retention and permeability properties of the components are dependent on porosity and the degree of saturation.
 A non-linear elastic model has been considered for the components, in which volumetric deformations are induced by net mean stress and suction changes. Therefore, the pellets and powder have different hydraulic and mechanical properties as a consequence of the different initial properties, but they share the same constitutive relationship of a single structured material. Figure 1c presents the time evolution of porosities (inside the pellets and powder), showing that the mixture tends towards a more homogeneous distribution of porosity as the pellets expand and compress the highly deformable clay powder. During the transient hydration stage, the expansion of pellets at the top of the column evolves faster due to the proximity of the hydration front. Figure 1d shows the water retention curves of the pellets and powder at the initial state and after hydration as predicted by the model, compared to experimental data [6,7]. The predicted water retention curves of the pellets and powder adequately follow the trend of the data reported by [7] and also seem to reproduce the mixture model data suggesting a homogenisation of the retention properties of the material after hydration.

Pengembangan Pakan Ikan Berprotein Tinggi Dari Keong Mas (Pomacea Canaliculata) Terhadap Ikan Nila (Oreochromis Niloticus) Dan Penerapannya Dalam Program Kerja Kuliah Kerja Nyata Di Masyarakat Desa Sungai Petai

This research focuses on developing high protein fish feed derived from golden snails with the addition of a mixture of fish pellets. The aim of this research is to produce high quality fish feed from available local resources and apply it in the Community Service Program (KKN) in village communities. Experimental methods were used to develop a feed formula with the right ratio of golden snails and fish pellets. The feed developed has a high protein content and a balanced nutritional composition. Furthermore, the KKN program was implemented in the village by involving students as facilitators in the socialization and application of high protein fish food to the community. The results show positive adoption of the feed by village communities and increased productivity of fish farming. This program provides dual benefits, namely increasing village community income through more efficient fish farming and supporting sustainable use of local resources.

Bentonite buffer under high temperature: laboratory experiments and coupled process modeling

Abstract. Bentonite buffer in a geological repository will be simultaneously heated from decaying radioactive waste and hydrated from the surrounding host rock, triggering complex and coupled THMC (thermal–hydrological–mechanical–chemical) processes. Understanding the THMC behavior of bentonite-based engineered barrier system (EBS) is key to the evaluation and prediction of its long-term performance. Studies on the THMC process have been focused on conditions under 100 ∘C, as most design concepts impose a thermal limit of 100 ∘C in bentonite. Recently, studies under high-temperature conditions have been conducted to evaluate the possibility of raising the thermal limit and expanding the data/knowledge base to increase the confidence level. In this abstract, we present a series of bench-scale laboratory experiments at high temperatures (up to 200 ∘C) and the corresponding modeling work. Two sets of column tests were conducted, and each set consisted of two test columns: a control column undergoing only hydration (non-heated) and an experiment column experiencing both heating and hydration (heated). During the experiment, frequent X-ray computed tomography (CT) images were collected to provide a 3D visualization of the density distribution and present the spatiotemporal evolution of (1) hydration/dehydration, (2) clay swelling/shrinkage, (3) displacement, and (4) mineral precipitation. The two sets of tests differ with respect to several experimental conditions, such as bentonite type, compacted density and water content, water chemistry, and hydration pressure, but the important difference is that the first set used bentonite powder with a dry density of 1.28 g cm−3, whereas the second set used granulated bentonite (mixture of pellets and powder) with a dry density of 1.45–1.5 g cm−3. In both sets of experiments, a comprehensive post-dismantling characterization of bentonite samples was carried out after the column tests had been running for 1.5 years. Comparing non-heated and heated columns, the temperature gradient led to lower degree of homogenization of bentonite after bentonite became fully saturated; comparing the first and second sets, granulated and powdered bentonite exhibited drastically different hydration behavior. A THM model with a 2D axisymmetric grid system was used to interpret the data from the first set of tests. The model considers the combined impact of saturation, fluid pressure, and porosity change due to swelling/compression on the spatiotemporal distribution of bulk density and movement of the thermocouple modules. Observations from the tests help us understand the early perturbation of bentonite buffer under high temperature, and data from these tests improve the calibration of key constitutive hydrological and mechanical models and, therefore, enhance the modeling capability with respect to calculating the long-term evolution of bentonite buffer.

Assessment of pellet mixture segregation during machine capsule filling

Assessment of pellet mixture segregation during machine capsule filling

Estimation of hot metal desulfurization by intermediate and final blast-furnace slag when using pellets of different basicity in blast-furnace charge

n the process of blast-furnace smelting, up to 90% of coke sulfur is captured by the iron ore charge, accumulating in hot metal in the amount that was absorbed from the gas phase. Desulphurization of cast iron occurs when it interacts first with the intermediate, and at the final stage, with the final blast-furnace slag. In this regard, it is of interest to evaluate the desulfurizing properties of the intermediate and final slag, which affect the sulfur content in hot metal. Melting mixtures of pellets of different basicity and sinter in a blast furnace leads to the formation of primary and intermediate slags of different chemical composition. When smelting hot metal in blast furnaces, mainly unfluxed pel-lets and fluxed sinter are used. In the course of the study, mixtures of sinter and pellets of different basicity were pre-pared, which ensured the production of final blast-furnace slag with a basicity of CaO/SiO2 = 1.15 units. The mixtures were reduced and melted in graphite crucibles with the smelting products filtered through a coke nozzle. The coeffi-cients of sulfur distribution between intermediate slag and hot metal obtained from iron ore charge with different basicity of sinter and pellets were determined. The lowest sulfur distribution coefficient between the intermediate slag and hot metal is observed when the basicity of the pellets is in the range of 0.5‒1.2 units. To increase the desulfurization capacity of the intermediate slag, it is advisable to use unfluxed and fluxed pellets with a basicity of 0.25 units in the blast-furnace charge and an sinter with a basicity of 1.78‒1.87 units. Studies of the kinetics of the interaction of hot metal and final blast-furnace slag have shown that the final slag provides a high degree of desulfurization of hot metal during their interaction for 1 hour or more

Temperature and alkaline solution effects on the hydro-mechanical behaviours of GMZ bentonite pellet mixtures

Temperature and alkaline solution effects on the hydro-mechanical behaviours of GMZ bentonite pellet mixtures

ORNL Progress in Disruption Mitigation Technology in Support of ITER

The mitigation of plasma disruptions in tokamaks has become a very important topic in magnetic fusion research, motived by the potential challenges that may occur in ITER disruptions due to the high magnetic field and high plasma current. Such disruptions can have a deleterious effect on the internal components due to the fast dissipation of the plasma thermal energy and the magnetic stored energy leading to large forces, as well as the possible formation of several megaamperes of energetic runaway electrons during the current quench. Oak Ridge National Laboratory has been developing and deploying technology to inject material into the plasma to rapidly radiate the thermal energy and start a fast plasma current ramp down to dissipate the magnetic stored energy. The choice of materials to inject and the injection technology have evolved over the past decades to arrive at the present systems planned for ITER based on cryogenic pellets of hydrogen-neon mixtures for thermal mitigation and hydrogen pellets for runaway electron mitigation. This scheme injects shattered cryogenic material into the plasma from pellets formed in situ in a pipe gun and fired onto angled metal surfaces at the end of the injection line just before entering the plasma. In this paper, we describe the evolution of schemes and technologies that have been employed for disruption mitigation and runaway electron prevention and dissipation, discuss how they have performed in present-day experiments, and give the outlook for the use of this technology in a burning plasma and how it may continue to evolve in the future.

The Diet of the West African Crested Tern Unveiled by an Analysis of Otoliths Collected Over 20 Years along Its Main Breeding Sites

This study reports on the diet of breeding West African Crested Terns Thalasseus albididorsalis on the basis of otoliths found in excrement (a mixture of pellets and faeces near nests). During the period 1998–2019, towards the end of the incubation period, excrement samples were collected from breeding colonies on islands, along the Atlantic coast from Mauritania to Guinea. In 31 samples with a total of 8956 otoliths we identified 53 fish families, 75 genera and 101 species. Twelve fish families occurred in more than 2% of the samples. The families of Haemulidae, Mugilidae, Pristigasteridae and Sparidae were particularly numerous (found in 10.5–15.7% of samples). The most numerous species were Bigeye Grunt Brachydeuterus auritus (9.8%) and West African Ilisha Ilisha africana (13.3%). There were marked differences in the diets of terns from the Banc d'Arguin (Mauritania), The Langue de Barbarie (northern Senegal) and all more southerly sites together (Senegal, The Gambia, Guinea Bissau and Guinea). On Ile aux Oiseaux, Delta du Saloum, Senegal, we found long-term changes in the diet of the terns with a marked decrease in Brachydeuterus auritus and the family Sparidae and a strong increase in Ilisha africana. Our analyses suggest that breeding West African Crested Terns are food generalists rather than specialists. This is surprising in view of the general trend in terns of the genus Thalasseus. There are indications that chick diets may differ from those of adults.

Large scale Vertical SEALing (VSEAL) test: Impact of gas migration on bentonite based vertical seals

The Institute for Radiological protection and Nuclear Safety (IRSN) has launched the VSEAL project to investigate the impact of gas migration on the long-term performance of bentonite based vertical sealing systems. This project relies on in-situ experiments emplaced in IRSN´s Underground ResearchLaboratory (URL) in Tournemire (South France) and small-scale tests conducted in laboratory. The studied material is mixture of MX80 bentonite high density pellets and powder which are being evaluated as possible sealing materials in deep geological repositories. The test is still in progress, but the collected set of data provides already valuable information of the hydro mechanical behavior of Vertical sealing systems during hydration.

A New Preparation Method for 3D Bio-composite Filament Manufacturing: a Study on the Effects of Ball Milling on the Cohesion/Adhesion of an Agave tequilana Bagasse/PLA Pellet Mixture

This study created a composite polymer for 3D printing from agave by-product using mechanical alloying process. The cold milling technique used by the ball mill is a standard procedure to homogenize metallic mixtures. This paper reports results from a series of laboratory tests to create a homogeneous mixture that could be extruded into a printable filament mixture of agave bagasse fibres and PLA pellets by using the kinetic energy of a ball mill. PLA and agave bagasse mixtures in this study were ground several times using this principle; steel and ceramic balls were used to grind them. The results of the study showed that this principle can be effective on a polymer-based mixture; indeed, an adhesion between the pellets and the agave bagasse fibres was obtained. The results showed the different parameters that influence the mixture quality as the milling time, the ball material, the number of balls, the mixture concentration and the rotational speed. Optical and ESEM/EDX analyses have confirmed our expectations about cohesion between fibres pulverized in powder and pellet adhesion, where powder accumulation on all the surfaces was detected. The absence of powder penetration in the pellets allowed us to explain the losses obtained during the process and to find new solutions to reduce them. Proof-of-concept parts were 3D printed with agave bagasse/PLA filaments. Their printed quality can be compared to that of commercial filaments. These results offer new perspectives to reuse agricultural by-products to create composite filament with a chemical-free manufacturing process.

Comparative Study between Fabricated Plastic Scintillator and Existing Product for Gamma Detection

A plastic scintillator with an injection method has been developed for a gamma radiation detector. The scintillator was made from the main matrix of polystyrene (PS) pellets with the addition of primary dopant PTP (para-terphenyl) 1.5% wt and secondary dopant as wavelength shifter (WLS) POPOP (1,4-bis [2- (phenyloxazolyl) )] - benzene) 0.01 - 0.05% wt. The mixture of pellets and dopants was fed to the extruder machine to obtain scintillating pellets and then referred to the machine to obtain a 3 mm thin plate plastic scintillator. The evaluation of absorption using a spectrophotometer UV-Vis showed that PS absorbs photons at a wavelength of 310 – 340 nm and PS containing POPOP produces a maximum emission at a wavelength of 421 nm. The evaluation of cesium 137 (137Cs) and cobalt 60 (60Co) gamma spectrum using the photomultiplier tube (PMT) Hamamatsu R878 showed the results of Compton spectrum characters with a gross counting maximum of 0.78 and 0.89, respectively, compared to the commercial plastic scintillator. The results of this study are expected to be usefully utilized in the development of a large-volume plastic scintillator for the radiation portal monitor (RPM).