Drum Rotation Research Articles

Optimisation of Electrospinning Parameters for High-Strength Oriented Pan Nanofibre Mats

Abstract This study explores the optimisation of electrospinning parameters to enhance the strength and orientation of polyacrylonitrile (PAN) nanofibre mats, which are pivotal in filtration applications and other areas requiring high-strength, uniformly distributed nanofibres. The focus is on the electrospinning process, particularly on a rotating drum collector, which is instrumental in determining the morphology of nanofibres. Key process variables, including the distance between the collector and the syringe, feed rate, applied voltage, and polymer concentration, have been meticulously examined to understand their influence on the physical properties of PAN nanofibres. Our findings indicate that parameters such as voltage, collector-to-syringe distance, and drum rotation speed (RPM) significantly impact the mechanical performance of the nanofibre mats. The optimised electrospinning conditions produced PAN nanofibre mats with tensile strengths ranging from 1.61 MPa to 21.78 MPa, demonstrating a notable improvement in strength due to controlled fluid dynamics and expulsion of polymer solution during the process.

Research on the Collection Characteristics of a Hydraulic Collector for Seafloor Massive Sulfides

Ore collection is very important in deep-sea mining for seafloor massive sulfide (SMS). In view of the characteristics of SMS ores produced by mechanical crushing, which contain coarse particles and a wide particle size distribution, in-depth research on the collection process with a device combining a rotary crushing head and a flat suction mouth was conducted. In this paper, solid–liquid two-phase flow in the hydraulic collection process with a drum rotation is carried out using the computational fluid dynamics-discrete element method (CFD-DEM), and the flow field characteristics and particle motion characteristics are analyzed. The results indicate that particles with a maximum diameter of 20 mm can be effectively collected when the suction velocity is 3 m/s. The collection process of SMS mainly goes through three stages: particle disturbance start-up, partial particle influx, and stable collection. In addition, the appropriate drum speed facilitates the collection of SMS ore. Finally, the correctness of the numerical method was assessed using similarity experiments. This work can be used to guide the design of underwater mining equipment.

Optimizing rotary kiln operations for molybdenite concentrate oxidation roasting to produce molybdic trioxide

The effects of the rotational speed (0–10 rpm) and temperature (550–650 °C) of rotary kiln drums on the oxidation roasting of molybdenite (MoS2) concentrate was investigated in this study. Computational predictions indicated that production of MoO2 was more favorable than that of MoO3 up to a certain stage of the oxidation roasting process, after which MoO3 is produced through the consumption of MoO2. Thus, understanding the MoS2–MoO2–MoO3 relationship and its equilibrium is important. A drum rotational speed > 5 rpm significantly increased the S reduction rate and considerably decreased the S content at 60 min to < approx. 5 %. Additionally, the S content at 60 min decreased with decreasing the temperature from 650 to 550 °C due to the MoS2 concentrate exothermic reaction during oxidation roasting. The MoS2 to MoxOy (≈ MoO2+MoO3) conversion rate (%) was generally proportional to the rotational speed and reaction duration. X-ray diffraction analysis indicated that 5–10 rpm and 550–600 °C yielded a higher experimental conversion rate (97–98 %). Furthermore, the MoO2 and MoO3 conversions were separately quantified. Agglomeration was more pronounced without drum rotation and at higher temperatures. Analysis of the reaction kinetics using the unreacted-core model indicated that diffusion through the gas film layer is supported by the 20.9 kJ/mol activation energy obtained from the Arrhenius plot. Consequently, an appropriate drum rotational speed at a relatively low temperature is a prerequisite for producing MoO3 through the oxidation roasting of MoS2 concentrates in a rotary kiln.

Preparation and Property Analysis of Antibacterial Fiber Membranes Based on Hyperbranched Polymer Quaternary Ammonium Salts.

Due to their excellent properties, antimicrobial fiber membranes are widely applied in bioprotective materials. This work addresses the preparation of thermoplastic polyurethane (TPU)-based fiber membranes with active antimicrobial properties. 2-hydroxypropyl trimethyl ammonium chloride-terminated hyperbranched polymer (HBP-HTC) was synthesized and used as an antimicrobial agent. The fiber membranes were obtained by electrospinning a mixed solution of HBP-HTC and TPU. Different electrospinning conditions were investigated, such as the spinning voltage and drum rotation speed. The fiber membrane prepared under a 22 kV anode voltage and 100 rpm rotation speed had an average fiber diameter of 1.66 μm with a concentrated diameter distribution. Antibacterial tests showed that when the fiber membrane was loaded with 1500 mg/kg of HBP-HTC, the antibacterial rates of E. coli as well as S. aureus both reached 99.99%, exhibiting excellent proactive antimicrobial performance. Moreover, the protective performance of the fiber membrane was outstanding, with a filtration efficiency of 99.9%, a hydrostatic pressure resistance greater than 16,758 Pa, and a moisture permeability of 2711.0 g⋅(m2⋅d)-1.

Design of a universal low-temperature rotary apparatus for making meat and vegetable products considering the integrated adaptive mechanism

The object of this study is the implementation of low-temperature processes for the production of meat and vegetable products under the conditions of adding a dried semi-finished product of a high degree of readiness to the recipe when using the designed universal rotary device of continuous action. The rotary device of continuous action for low-temperature processing of meat and vegetable products with a cylindrical working chamber is heated by a film-like resistive electronic heater of the radiating type. It has a stationary wall (with a technical door for unloading and loading the device) and a technical wall (with an opening angle of 90°). On the inner surfaces of the walls, inclined converging ribs with an angle of 25° are installed, which are covered with an electric heater. Semi-finished meat and vegetable products are loaded onto carts with technological containers and mounted on a frameless drum (rotation frequency 0.03...0.06 s–1). The device converts secondary thermal energy into low-voltage power supply voltage (~3...8 W) for autonomous operation of fans. The proposed integrated adaptive mechanism for the system of complex interaction of the agricultural, processing, and production sectors implies the formation of resource efficiency of production processes from "farm to table". The designed device implements the process of frying meat-vegetable bread under conditions of reaching 80 °C in the center of the product. The obtained temperature field data confirm the uniformity of the temperature field during frying of the product (cooking readiness of the product at the initial weight of 650±20 g – 4.0 hours). The introduction of a multicomponent dried fraction based on potatoes, Jerusalem artichokes, zucchini, and carrots into the recipe of meat-vegetable bread reduces the weight loss of the semi-finished product during frying by 12.3 %. It increases the content of calcium, phosphorus, vitamin C accompanied with a decrease in energy value by 28.1 %

The impact of changing drum rotation direction on fabric motion and drying performance in clothes dryers

Fabric motion in tumble dryers, particularly the motion observed from the cross-section of the rotating drum, contributes significantly to the heat and mass transfer between textiles and the surrounding hot airflow. However, the wider picture for this process is not yet clear and requires further study. In this article, fabric motion with different drum rotation direction settings was analyzed experimentally to determine the effect of drum rotation direction on drying performance. A high-speed video camera was used to record the fabric motion during the entire drying process. The recorded movies were then processed, and the velocity and occupancy distributions of the tracer fabric and several motion indexes were analyzed by using OpenCV and Matlab. The results indicated that changes in the drum rotation mode cause significant variations in the dynamics of fabric motion in domestic tumble dryers across different drying conditions with variations in fabric size, drum rotation speed and load size. Constantly changing drum rotation direction plays an important role in enlarging the motion area and reducing the passive motion area, lifting the textiles up to a higher place and agitating the mixture inside the rotating drum. This means that the fabrics can be effectively scattered instead of tangling together, and because this drying condition provides more opportunities for them to be exposed to the surrounding hot airflow, it enhances convective heat and mass transfer within the drying chamber and reduces the formation of wrinkles on fabrics. This study could lead to new guidance for obtaining effective fabric motion patterns that lead to an optimal drying performance.

Research on dynamic characteristics of cutter breaking frozen soil and optimal drum rotation speed of the new shaft tunneling machine

To improve the efficiency of frozen soil excavation, the new shaft tunneling machine was developed. The new shaft tunneling machine exerts pressure on the frozen soil through the cutter under the joint action of its own gravity, the drum rotational force and the inertia force, and the frozen soil is damaged. By unique way of breaking frozen soil to improve the efficiency of frozen soil excavation, the drum rotation speed is one of the factors affecting the performance of frozen soil excavation. This article applies SolidWorks software to establish the model of cutter breaking frozen soil, takes advantage of Hyper Mesh finite element software coupled with LS-DYNA solver to acquire the regular pattern of change in the force change, frozen soil stress–strain and specific energy of cutter crushing frozen soil, etc., which analyzes the destruction of frozen soil when the drum of the new shaft tunneling machine is rotating at the speed of 25–40 rpm. Combine with field test to investigate the mechanism of cutter breaking frozen soil under the optimal drum rotation speed. The investigation results demonstrate that: when frozen soil's self-bearing capacity is lower than the force of cutter, it breaks up and detaches from the soil body, and frozen soil undergoes tensile, compressive and shear damages. For this research, it is instructive for practical engineering.

Analysis of Temperature Distribution on the Coffee Roaster Drum for a Capacity of 2 kg Using Computational Fluid Dynamics (CFD)

Coffee, one of Indonesia's largest commodities, is often processed using traditional methods and tools that rely heavily on manual labor and can be labor-intensive. To make the coffee roasting process more efficient and reduce the need for human effort, a coffee roasting machine can be used. This study aimed to analyze coffee roasting drums using computational fluid dynamics (CFD) to determine the optimal drum thickness and rotation speed in a coffee roasting machine. The study considered three different thicknesses (1mm, 2mm, and 3mm) and three different rotation speeds (60rpm, 65rpm, and 70rpm). The coffee roasting drum was modeled using CFD. The study's results showed that a drum thickness of 2mm and a rotation speed of 70rpm achieved the best heat distribution during roasting, reaching the desired temperature in 900 seconds. This information could be used to design a more efficient coffee roasting machine or improve the performance of existing machines.

Development MPC for the Grinding Process in SAG Mills Using DEM Investigations on Liner Wear.

The rapidly developing mining industry poses the urgent problem of increasing the energy efficiency of the operation of basic equipment, such as semi-autogenous grinding (SAG) mills. For this purpose, a large number of studies have been carried out on the establishment of optimal operating parameters of the mill, the development of the design of lifters, the rational selection of their materials, etc. However, the dependence of operating parameters on the properties of the ore, the design of the linings and the wear of lifters has not been sufficiently studied. This work analyzes the process of grinding rock in SAG mill and the wear of lifters. The discrete element method (DEM) was used to simulate the grinding of apatite-nepheline ore in a mill using different types of linings and determining the process parameters. It was found that the liners operating in cascade mode were subjected to impact-abrasive wear, while the liners with the cascade mode of operation were subjected predominantly to abrasive wear. At the same time, the results showed an average 40-50% reduction in linear wear. On the basis of modelling results, the service life of lifters was calculated. It is concluded that the Archard model makes it possible to reproduce with sufficient accuracy the wear processes occurring in the mills, taking into account the physical and mechanical properties of the specified materials. The control system design for the grinding process for SAG mills with the use of modern variable frequency drives (VFD) was developed. With the use of the proposed approach, the model predictive control (MPC) was developed to provide recommendations for controlling the optimum speed of the mill drum rotation.

Particle-size segregation patterns in a partially filled triangular rotating drum

In this paper a fully coupled particle-size segregation model for granular flows (Barker et al., J. Fluid Mech., vol. 909, 2021, p. A22) is used to simulate the development of the patterns in a triangular rotating drum. The results are compared with the experimental patterns formed with bidisperse and tridisperse granular mixtures, and with varying compositions and fill heights. In all cases the agreement between the simulations and experiments is remarkably good. The experimental patterns are generated in a narrow gap between transparent front and back sidewalls. These prevent three-dimensional motion, but also impose friction on the flow, making it thinner and faster than it would otherwise be. This promotes segregation, as it simultaneously increases the shear rate and reduces the local pressure. To obtain the correct flow dynamics and segregation, width-averaged sidewall friction is incorporated into the two-dimensional simulations, which are performed in OpenFOAM $^{\circledR}$ . The free-surface avalanche forms a boundary layer within which all the segregation occurs. Material in the lower reach of the avalanche is continuously deposited into an underlying solid body of grains, which rotates with the drum, and is eventually re-entrained into the avalanche along its upper reach. The changing geometry of the granular region (as the drum rotates) implies that the avalanche is constantly adjusting its length, position and depth. This generates a complex quasi-periodic flow, which when combined with particle-size segregation generates amazing patterns in the solid rotating granular body after only two drum rotations.

Experimental and numerical evaluation for drum dynamic reliability under extremely complex working conditions

Coal mining machine drums are prone to damage and malfunction under extremely complex working conditions, which seriously affects the efficiency and safety of coal production. In this paper, based on the theory of coal rock cutting and virtual simulation technology, finite element models of drum cutting coal rock were established and then verified by physical experiments. Through simulation analysis, the dynamic reliability of the drum was studied from three aspects: load, stress and wear, and a mathematical model of drum load was established with respect to the traction speed and drum rotation speed; based on the orthogonal test, the optimal working parameters to improve the wear resistance of the drum were derived. The results of the study found that when the traction speed increases, the load on the drum increases, and when the drum rotation speed increases, the load on the drum decreases; when the traction speed is increased from 2 to 6 m/min, the stress on the pick body under different rotation speeds increases to different degrees, with an average increase rate of 27.394%; when the drum rotation speed is 90 r/min, the traction speed is 3 m/min, and the coal loading mode is projectile loading, the wear depth of the picks and spiral blades is relatively small. The research method and results of this paper can provide a reference for the selection of the drum working parameters.

DIRECT NUMERICAL SIMULATIONS OF TWO-PHASE FLUIDS INTERFACE IN 2D ROTATING DRUMS USING A COUPLED VOF–IBM NUMERICAL APPROACH

Rotating drums play important roles in numerous industrial applications, such as mineral processing. This work is focused on the numerical study of the interface evolution in liquid-liquid and liquid-gas phase rotating drums. A new coupling strategy between volume of fluid (VOF) and immersed boundary method (IBM) approaches is developed. Relevant dimensionless numbers, including Reynolds, Froude, and Bond numbers, alongside viscosity and density ratios, are considered for the flow pattern characterization. Direct numerical simulations are performed in order to explore flow regimes within the rotating drum, addressing a gap in the literature concerning less-explored flow patterns, particularly in the rotating drum containing liquid-liquid phases. The flow pattern families characterizing rotating drums carrying liquid-liquid phases found in this study are (i) gravity stratified, (ii) mixing, (iii) annular, and (iv) rotation stratified flows. Additionally, the characteristic flow pattern families, (i) gravity stratified, (ii) pool, (iii) annular with pool, and (iv) annular flows, are identified in rotating drums carrying liquid-gas phases. The difference in the transitory responses between the rotating drum featuring liquid-liquid and liquid-gas phases is also shown and discussed. The main results highlight significant contributions for understanding the dynamics of rotating drums, particularly concerning the transitional interface development. By identifying new flow patterns and exploring transitional phenomena, this study enriches the understanding of complex fluid behavior within rotating drum configurations.

Development of egg yolk powder using a small-scale double drum dryer: Influence of steam pressure on physical properties

Egg yolk powder is a versatile and widely used food ingredient. Double drum dryers have been widely used in the food industry for many years, but no report was found that utilize drum dryer to produce powdered eggs. This study aimed to investigate double drum drying process conditions, especially steam pressures which consisted of three different conditions: 2.5, 3, and 3.5 bar with drum rotation of 2 revolutions per minute (rpm) to produce chicken egg yolk powder. Once egg yolk powder resulted, the products were evaluated in terms of yield, moisture content (MC), water activity (aw), bulk densities (ρB) and tapped densities (ρT), and color (L*/a*/b* coordinates). Results showed that steam pressures affected several parameters including yield, MC, aw and color properties of egg yolk powder but did not affect ρB and ρT. The egg yolk powder yielded was in range of 48–52%. MC and aw of egg yolk powder were in a range of 3.6– 5.1% and 0.38–0.43, respectively. In terms of density, the egg yolk powders had 0.40-0.43 g/cm3 and 0.46-0.48 g/cm3, for ρB and ρT, respectively. Regarding color, egg yolk powder was medium bright (59–62), less red (5–6), and yellowish (26-28). The double drum dryer is a promising technology for producing chicken egg yolk powder and prolonging its shelf life.

Determination of the optimal modes of operation of the clover grater and scarifier KS-0.3 P during scarification

The article provides information about the features of the device, the quality of work of the prototype of a new 25...30 % more productive clover grater and scarifier KS-0.3 P in comparison with the analogue KS-0.2 P. KS-0.3P includes a drum-type wiping and scarifying device, a pneumatic separation device, a two-stage exhaust air purification system containing a cyclone and a fabric filter. The increase in the productivity of the new machine is achieved by increasing the diameter of the drum with a solid wiping surface to 0.45 m and the length of the oval deck with scarifying plates to 0.7 m. The solid grating surface of the drum is welded from steel rods of hexagonal profile No. 12 mounted on an edge. The deck covering the drum from below by 180° is made of round bars with a diameter of 10 mm and nine steel plates with a thickness of 2 mm and a width of 11 mm, evenly distributed along the length of the deck. When studying the technological process of clover grater and scarifier the method of mathematic planning of the experiment was used. The quality of scarification done was evaluated using the GOST 12038-84, GOST 12036-85 methodologies and additionally introduced indicator of variation of the number of germinated seeds. The material supply was regulated by the degree of opening of the flap in the loading hopper in the range from 0.2 to 0.4 t/h. The rotation frequency of the drum was changed by a frequency converter from 550 to 650 min-1. Eastern galega seeds met GOST 52325-2005 requirements. The experiments were carried out in three-fold repetition. As a result of an experimental study of the KS-0.3P cloverworm-scarifier during the scarification of the seeds of the Eastern galega, the ranges of the optimal drum rotation speed of 550... 650 min-1 and the material supply of 0.3... 0.4 t / h were determined, when the specified agrotechnical indicators were provided: the degree of scarification not less than 95.0 % and crushing not more than 1.5 %.

A study of new washing machine for the care of delicate garments by testing on wool and silk fabrics

There is an increasing demand for gentle laundry and care of the delicate and high-end garments for maintaining their performance and appearance during the use. A tapping washing system was designed for the care of delicate garments. Adjustable and steady up-down tapping force was applied on fabrics or garments during laundry through the centric slider-crank mechanism with control parameters, such as the magnitude and frequency of the tapping force, washing temperature and duration, etc. By comparing with traditional drum rotation washing on wool and silk fabrics, the tapping washing method could prevent felting shrinkage of wool fabrics and crease of silk fabrics, and maintain their good appearance, although the washing efficiency for the removal of soils from garments needs to be further explored. The newly designed prototype of the tapping washing device could be the foundation for future research on gentle washing without the movement of fabrics but circulation of detergent washing solution during tapping action on the fabrics.

Experimental and Computational Fluid Dynamics Investigation on Tanning Process in a Rotating Drum

Mass transfer of chemicals greatly affects leather production efficiency and product quality. Leather shows different motions in a rotating drum during processing, which is strongly associated with chemicals’ mass transfer. However, how leather motions affect mass transfer remains unclear, which disfavors highly efficient leather manufacturing process. Here, different leather motion states were obtained by adjusting the drum rotation speed. Experimental results showed that the duration of leather rolling motion greatly increased by 41% when the rotation speed increased from 5 r/min to 20 r/min, and the uptake of the tanning agent was consequently improved, which indicated that the rolling motion is beneficial to mass transfer. Computational fluid dynamics simulation results showed that the mass transfer rate under rolling motion was higher than those under slipping, elevating and hanging motions, because the flow velocity and concentration gradient near the leather surface were higher under rolling motion. Accordingly, increasing the rolling motion enhanced the mass transfer in leather processing. This work identifies the leather motion beneficial for mass transfer and provides guidance on operating condition optimization and drum design for high-efficiency leather production.

Drying Schinus terebinthifolius leaves in a rotating drum dryer – Evaluation of the product quality and energy consumption by RSM models

The performance of a specially designed rotating drum for processing medicinal leaves was evaluated for air drying Schinus terebinthifolius leaves. The study is aimed at investigating the influence of air temperature, air velocity, leaf mass load, and drum rotation speed on leaf drying. Response Surface Methodology (RSM) was employed to optimize the drying conditions. Second-order polynomial equations were used to assess the effects of drying conditions on drying time, color degradation, and energy consumption. Based on the analysis, the optimum drying conditions were determined to be an air temperature of 52.5 °C, air velocity of 0.3 m/s, and a mass load of 200 g. The predicted values of drying time, specific power input and the chromatic parameter a*/b* at this optimal condition were 499 min, 14.4 kWh/kg and − 0.063, respectively. Furthermore, a comparison between ethanolic extracts obtained from fresh leaves and those from dried leaves revealed a significant decrease in total phenolic compounds (TPC) and antioxidant activity (AA) in the extracts from the dried leaves. Among the tested conditions, the best result for both TPC and AA was observed in the extracts of leaves air dried under 50 °C and 0.60 m/s, in which the TPC and AA dropped respectively from 75 mg GAE/mg dry matter and 90 % to approximately 22 mg GAE/mg dry matter and 88 %. The air temperature was identified as the most influential factor affecting the quality attributes of dried leaves and their extracts. The rotating drum proved to be an effective alternative for drying herbs and medicinal leaves.

Fabricating orientated nanofibrous meshes with a bespoke ultra-cost-effective electrospinning machine

Electrospinning's production method has been streamlined and perfected because to advancements in technology and increased demand. While working with electrospun fibers, it is crucial to ensure that they are collected in the correct orientation. Electrospun fibers can be either aligned or random. In contrast to randomly oriented fibers, all aligned ones will point in the same direction. Our results show that a low-cost, tailored electrospinning device can achieve equivalent performance to that of a commercially available system. High voltage (up to 36 kV) and nanofiber orientation adjustments are now being made to the proposed device. A high-voltage direct-current electrical power supply that is custom-built per order and wired by hand. Two specialized collectors, one portable and manufactured from conductive material for random nanofibers, and the other an inexpensive rotational drum collector for aligned nanofibers, have been developed to allow for precise orientation control. By applying Image J software to scanning electron micrographs, we were able to determine the average diameter and orientation of the fibers produced by the electrospinning apparatus, demonstrating its potential to produce nanoscale directed fibers. Because of this research, it's possible that schools will be able to afford an electrospinning system at a price far lower than the current market price.

Interfacial Dynamics Around a Swirling Roller in the Presence of Oppositely Imposed Horizontal Crossflows

Abstract The behavior of interfacial dynamics around a swirling circular drum is reported in the presence of horizontal crossflows of gaseous phase. A constant submergence ratio of the rotary drum is considered throughout this work. Forward and reverse crossflows are defined based on the direction of rotation of drum. A clockwise rotation is imposed on the drum and the rotation direction remains fixed throughout the present investigation. The pattern of film flow and cusp entrainment is observed thoroughly by considering rotational speed (ω) and strength of crossflow as influencing parameters. Strength of crossflow of gaseous phase is calibrated using flow Reynolds number based on roller diameter (Reflow=ρgUD/μg). Subsequently, we characterized the coated film thickness (h*=h/D) and cusp width (H*=H/D) by varying ω and Reflow. Furthermore, efforts are made to observe the influence of gravitational pull (calibrated using Archimedes number, Ar) and viscous drag (determined using Morton number, Mo) on interfacial morphology. The interfacial structures respond more to the rotational inertia compared to crossflow with the continuous increase of Mo. Again, the trailing end of cusp gets widened for the case of forward crossflow, whereas the cusp growth is obstructed in the presence of reverse crossflow, which is visualized using velocity vectors. We have also predicted appropriate correlations for film thickness (h*), cusp width (H*), and steady cusp length (θs*) in the presence of forward as well as reverse crossflow of air stream. Lastly, a theoretical framework is also developed to estimate film thickness and cusp width for both cases of crossflows and this framework agrees well with the simulated predictions.

A Bayesian approach for measuring nuclear material in radioactive waste using photofission

Photofission provides a mean for measuring nuclear material in large and dense radioactive waste packages. High-energy interrogating bremsstrahlung photons produced by a LINAC are indeed able to induce fissions in the depth of the waste matrix. In addition, a scintillation detector can detect high-energy delayed gamma rays that are able to escape the waste package. Scintillation detectors also allow performing measurements during photon irradiation, between LINAC pulses, to measure delayed gamma rays from short-lived fission products. Photofission measurement with a LaBr3 scintillation detector can help determining, in a Bayesian frame, the mass and position of actinides in radioactive waste packages. In addition to counting statistics, the model takes into account photofission yields and waste matrix density uncertainties. The model performances are numerically illustrated in the case of a 235 g238U lump placed inside a 50 cm radius drum homogeneously filled with 2.35 g/cm3 density concrete. In the most unfavourable angular position, with 32 drum rotations, when the 238U radial position is 10% and 90% of the waste drum radius, the expected relative uncertainty on the 238U mass is respectively 32% and 45%. The 238U angular position uncertainty is 10 mrad and its radial position can be determined with an expected uncertainty of 2 cm and 3 cm, when the 238U is respectively placed at 10% and 90% of the waste drum radius.