Ring Diameter Research Articles

Depth encoding PET detectors using single layer crystal array with different reflector arrangements along depths

Abstract Depth encoding detectors are preferred for PET scanners with a small ring diameter and a long axial field of view. In this work, novel depth encoding detectors using different inter-crystal reflector arrangements along the depth of single layer crystal arrays are proposed and their performance is evaluated. As compared to the previous four-layer detector with different reflector arrangements, the detectors proposed in this work are expected to improve the energy and timing resolution of the detectors. 4 × 4 LYSO arrays with a crystal size of 3 × 3 × 20 mm3 and 6 × 6 LYSO arrays with a crystal size of 2 × 2 × 20 mm3 are fabricated using two and four reflector arrangements along the crystal’s depth. The LYSO arrays are single-ended read out by 4 × 4 SiPM arrays with a pixel size of 3 × 3 mm2. The first and second half of the crystals are clearly resolved from the flood histograms for the two detectors with two reflector arrangements. 80% of the events can be correctly assigned to each half. The detectors provide a two layer depth encoding capability. The photopeak value and average energy resolution of the first and second half of the crystal are almost the same. The average crystal energy resolutions of the 4 × 4 and 6 × 6 LYSO arrays with two reflector arrangements are 10.4% and 11.6%, respectively. The timing resolutions of the two detectors are 284 ps and 442 ps for an energy window of 400 ∼ 600 keV. However, each quarter of the crystals cannot be clearly resolved for the two detectors with four reflector arrangements and further optimization is still required. The detectors developed in this work simultaneously provide a two layer depth encoding capability, good energy and timing resolution, and show great promise for developing high performance dedicated brain, whole body and total body PET scanners in the future.

Towards a Low-Cost and Portable Photoacoustic Microscope for Point-of-Care and Wearable Applications.

Several breakthrough applications in biomedical imaging have been reported in the recent years using advanced photoacoustic microscopy imaging systems. While two photon and other optical microscopy systems have recently emerged in portable and wearable form, there is much less work reported on the portable and wearable photoacoustic microscopy (PAM) systems. Working towards this goal, we report our studies on a low-cost and portable photoacoustic microscopy system that uses a custom fabricated 2.5 mm diameter ring ultrasound transducer integrated with a fiber-coupled laser diode. The ultrasound transducer is centered at 17.25 MHz, and shows ~ 45% and ~ 100% fractional bandwidths for ultrasound pulse-echo and photoacoustic A-line signals respectively. To achieve overall system portability, besides the imaging head, other backend imaging system components need to be readily portable as well. In this direction, we have studied the potential use of compact pre-amplifiers, scanning stages and microcontroller based data acquisition and reconstruction for photoacoustic imaging. The portable PAM system is validated by imaging phantoms embedded with light absorbing targets. Future directions that will likely help achieve a completely portable and wearable photoacoustic microscopy system are discussed.

The inaccuracy of the endoscopic anastomotic measurement techniques

Background: Roux-en-Y gastric bypass (RYGB) is a reliable treatment for obesity, and most of the people do lose weight after the surgery. However, there are risks for the failure to lose weight or weight regain. One of the primary reasons for weight regain after the RYGB is the size of the anastomosis at the gastrojejunostomy (GJ). There is no standard endoscopic technique for the measurement of this anastomosis. Consequently, many treatment plans may lead to ineffective intervention. This study was performed to identify the most accurate method to measure the luminal diameter of GJ endoscopically. This may allow better management of the patients with weight regain after the RYGB. Methods: Ten subjects were asked to endoscopically measure a ring of known diameter at the end of a plastic tube representing the esophagus using four commonly used endoscopic measuring techniques and a double channel endoscope. Subjects used (I) visual estimation (VE); (II) instrument reference (IR) to biopsy forceps; (III) esophageal dilating balloon (EDB); (IV) ruler made from an endoscopic retrograde cholangiopancreatography (ERCP) guide wire tip. The five models were presented in random order. The data was collected and saved in the institutional database. Results: A total of 10 participants, 9 surgeons and 1 gastroenterologist, participated in the study. Endoscopic experience was >1,000 scopes for 4 subjects; 250–500 for 3, and <100 for 3. The VE was the least accurate with an average diversion (AD) from the actual diameter of 6.25±4.95 mm (24.2%); followed by IR, 3.89±3.05 mm (14.8%); then the ruler, 2.4±1.9 mm (9.2%). The balloon measurement was the most accurate, with AD of 1.46±0.9 mm (7.2%). Of the 200 total measurements, 8 (4%) were accurate, 142 (71%) were underestimating, and 50 (25%) were overestimating. Underestimation was found in 82.5% (33/40) of each of the VE and IR methods; while it was less in the ruler method 60% (24/40); and least in the balloon method 40% (16/40). Additionally, the overestimation was highest in balloon method 55% (22/40), followed by ruler method 35% (14/40), then IR 15% (6/40); and lowest in VE 12.5% (5/40). Measurements of the largest model diameter (33 mm) were 98% underestimating; while only 2% were overestimating. In the smallest diameter model (13 mm), 16% of the measurements were underestimating; 2% were accurate, and 82% were overestimating. Conclusions: Endoscopic VE of anastomosis diameter is the least accurate method of measurement leading to the overestimation of the measurements. It is, therefore, highly recommended that endoscopists avoid using only VE entirely for the measurement of GJ. More objective methods may be considered for the measurement of GJ diameter.

Thermal performance enhancement in a parabolic trough receiver tube with internal toroidal rings: A numerical investigation

The present work investigates the incorporation of internal toroidal rings in an absorber tube of a solar parabolic trough collector (SPTC) with an objective to enhance the thermal performance. To produce substantial effect on the heat transfer rate, nine different cases of absorbers have been considered. The fully developed turbulent heat transfer characteristics of the absorber tube have been numerically studied and validated under varying inlet temperatures and flow rate of the heat transfer fluid (HTF). Realizable k-ε two-equation turbulence model with enhanced wall treatment has been used with ANSYS FLUENT 15 commercial codes. The influence of toroidal rings on heat transfer and fluid flow are evaluated and presented. The absorber with toroidal ring having a diameter ratio (H) of 0.88 and pitch size (p) of 2d is the thermally efficient optimal case. While the absorber with H = 0.92 and p = 2d is the energy efficient optimal case, with H being the ratio of inner to outer diameter of the toroidal ring and 2d being the distance between the adjacent rings, which is equal to two times the inner diameter of the absorber tube. When the inlet temperature of HTF is 600 K, the increase in efficiency for the thermally efficient and energy efficient optimal case are found to be 3.74% and 1.88%, while the increase in Nusselt number is found to be 2.33 and 1.49 times higher than the smooth absorber tube (SAT), respectively.

Characterization of the residual stresses introduced by a new joining method in diamond and tungsten carbide composites

In this work, a co-sintering method was used to attach diamond to cemented carbide composites. The joining method consists of sintering a green part (ring) of cemented carbide (CC) around a thermally stable diamond composite (TSDC) part (plug) to radially contain it. During the sintering step, the green body shrinks to a controlled level and therefore forms interference fit between the two parts (mismatch between the inner diameter (ID) of the CC ring and the outer diameter (OD) of the TSDC cylinder). The residual stresses induced by this process as well as the bond strength between the CC and the TSDC parts were quantitatively evaluated. It is shown that the interface pressure between the two parts, and the level of residual stresses, increased with increase in the designed interference fit, as well as with the increase of the ID/OD ratios of the CC ring.For the chosen material combination (cemented carbide ring comprised 90 vol% WC and 10 vol% Co with medium coarse WC grains; diamond composite plug comprised 84 vol% diamond and 16 vol% SiC), the values of the hoop stresses at the interface in the CC ring measured by neutron diffraction was determined to be between 150 MPa and 550 MPa, depending on the ID/OD ratio. It was also found that for a given ID/OD ratio, the increase of the designed interference fit had little effect on that attained due to the plastic deformation of the cemented carbide material at the interface during the sintering (dynamic) process. A mechanical bond around 60 MPa was nevertheless achieved.

LSPR Excitation on Au Nanorings From Integrated Hybrid Plasmonic Aperture Waveguide and Its Application in Methanol Detection in the IR-Band

The presented work deals with an infra-red (IR)-band methanol sensor, which has been realized in an integrated device having hybrid plasmonic aperture waveguide and Au-nanoring array over broad wall of it covered by porous silicon clad. Through modeling and numerical simulations, we have shown that suitable synthesized aperture in the waveguide can excite localized surface plasmon resonance (LSPR) on the nanorings of suitable diameter via radiative field coupling, whereas LSPR can be tuned with the received methanol by the porous silicon clad. Thus, by contrasting the power available at the sense port of the waveguide with null and finite methanol doses, we have determined sensitivity (STM) and figure of merit (FOM) of the sensor, and our further analyses suggest that the sensor response can be tailored by diameter of aperture and ring, and by the porosity of the silicon cladding medium. In this respect, we have found that, for 20%-45% clad porosity, S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TM</sub> = 77.95-66.66 nm/RIU and FOM = 17.51-7.66/RIU can be achieved during methanol detection.

Reversible Modulation of 2D Photonic Crystals with a Responsive Shape‐Memory DNA Hydrogel Film

AbstractResponsive DNA hydrogels are smart soft materials that have attracted significant attention in the past decade in various research fields, especially in biosensing. However, several limitations of DNA hydrogels, such as non‐recyclability, slow response, and high manufacturing cost, severely hamper their biosensing applications. In this work, shape‐memory DNA hydrogel film with thickness at micrometer scale is developed, serving as both target recognition unit and actuating unit for the regulation of 2D photonic crystals (2D PCs) embedded on the surface of the hydrogel film. External stimuli can drive the reversible shape changes of the DNA hydrogel films and therefore modulate the lattice spacing of 2D PC array, which can be directly observed by the diameter changes of the Debye diffraction ring. Compared with the bulk hydrogels, these DNA hydrogel films possess the advantages of lower cost and faster stimuli response; more importantly, diameter of the diffraction ring as signal output avoids the requirement of sophisticated instruments. pH‐responsive or Ag+/cysteine (Cys) responsive DNA hydrogel films are successfully developed as model systems to demonstrate the successful reversible modulation of the lattice spacing of 2D PCs. These smart DNA hydrogel film systems may have great potential in the development of future portable and visual biosensing devices.

Drying pattern and evaporation dynamics of sessile ferrofluid droplet on a PDMS substrate

The present study reports the evaporation dynamics, deposition pattern, effect of magnetic field and mechanism behind the pinning or depinning of the contact line of sessile ferrofluid droplet on a PDMS substrate. The concentration of ferrofluid has been varied as 0.0%, 0.1%, 1.0%, and 5.0%. Optical profilometry, confocal microscopy, micro-PIV and goniometry measurements have been carried out. The average evaporation rate increases with increase in ferrofluid concentration i.e. about twice increase in evaporation rate is observed at 5% ferrofluid concentration compared to 0.0% concentration. Crack formation takes place inside the coffee ring of the drying pattern. The crack size i.e. length and width increase with increase in ferrofluid concentration, which can be correlated to the drainage of solvent by the capillary action and formation of cluster. The contact line motion is a function of ferrofluid concentration, which influences the diameter of the coffee ring. The width of the coffee ring, the contact line velocity of the droplet during the receding phase and total drying period decrease with increase in concentration of ferrofluid. The contact line stops receding if the frictional force exceeds the horizontal component of surface tension force at a critical particle density in the contact line region. The application of magnetic field leads to uniform deposition pattern of the drying droplet, which can be correlated to higher duration of mixed mode evaporation of the ferrofluid droplet.

Multimodal structural disease progression of retinitis pigmentosa according to mode of inheritance

We analyze disease progression in retinitis pigmentosa (RP) according to mode of inheritance by quantifying the progressive decrease of the ellipsoid zone (EZ) line width on spectral domain optical coherence tomography (SD-OCT) and of the dimensions of the hyperautofluorescent ring on short-wave fundus autofluorescence (SW-FAF). In this retrospective study of 96 patients, average follow-up time was 3.2 ± 1.9 years. EZ line width declined at a rate of −123 ± 8 µm per year, while the horizontal diameter and ring area declined at rates of −131 ± 9 µm and −0.5 ± 0.05 mm2 per year, respectively. Disease progression was found to be slowest for autosomal dominant RP and fastest for X-linked RP, with autosomal recessive RP progression rates between those of adRP and XLRP. EZ line width and ring diameter rates of disease progression were significantly different between each mode of inheritance. By using EZ line width and horizontal diameter as parameters of disease progression, our results confirm that adRP is the slowest progressing form of RP while XLRP is the fastest. Furthermore, the reported rates can serve as benchmarks for investigators of future clinical trials for RP and its different modes of inheritance.

Effect of chronic topical latanoprost on the sclera and lamina cribrosa of form-deprived myopic Guinea pigs

The purpose of this study was to investigate the effects of latanoprost, an ocular hypotensive prostaglandin analog, on scleral collagen fibers and laminar pores in myopic guinea pigs. Young guinea pigs underwent monocular form deprivation (FD; white plastic diffusers) from 14-days of age for 10-weeks. After the first week, FD eyes also received daily topical A) latanoprost (Lat, 0.005%, n = 5) or B) artificial tears (AT; n = 5). At the end of the treatment period, animals were sacrificed, eyes enucleated and optic nerve heads (ONH) excised to include a 4 mm diameter ring of surrounding sclera for scanning electron microscopy (SEM), and an additional 6 mm ring of sclera surrounding the ONH was excised for transmission electron microscopy (TEM). For SEM, ONH samples were first immersed in 0.2M NaOH for 30 h to isolate the collagenous structures. All samples were stained with osmium tetroxide, dried through an ethanol series and finally subjected to critical point drying before imaging. Image J was used to analyze the dimensions of laminar pores (SEM images) and scleral collagen fibers (TEM images). As previously reported in a related study, latanoprost was effective in inhibiting myopia progression in FD eyes of the guinea pigs. The scleral fibers of FD myopic eyes treated with AT were smaller and more variable in cross-sectional areas compared to untreated (fellow) eyes (mean areas: 0.0059 ± 0.0013 vs. 0.0085 ± 0.002 μm2; p < 0.001), consistent with scleral changes reported for human myopia. In contrast, the scleral fibers of the Lat-treated FD eyes were similar to those of fellow eyes (0.0083 ± 0.002 vs. 0.0078 ± 0.0014 μm2). However, laminar pore size appeared unaffected by either the FD or drug treatments, with no significant difference found between FD eyes and their fellows, for either treatment group. That daily topical latanoprost appeared to protect against myopia-related changes in scleral collagen, rather than exaggerating them, as might be predicted from its known action on the uveoscleral extracellular matrix, lends further support its use for myopia control. In this guinea pig myopia model, the lamina cribrosa appeared unaffected.

Definition of giant inguinoscrotal hernias in infants and evaluation of reliable surgical approach in a single-center study.

ObjectiveInguinal hernia surgery is the most common surgery performed by pediatric surgeons. Giant inguinoscrotal hernia has not been clearly defined yet. The definition of giant inguinoscrotal hernia and the reliability of the surgical procedure were investigated in this study.Materials and methodsSixtyfour of totally 1548 male patients who have been operated with inguinal hernia from May 2015 to January 2018 were included in the study considering the diagnosis of giant inguinoscrotal hernia. The criteria for the diagnosis of giant inguinoscrotal hernia were determined as, observing that the hernia sac was filled with intestinal loops from the inguinal region to the scrotum during the physical examination, herniation of the intestines to the scrotum again as soon as the hernia was reduced and 2 cm and above inner ring diameter. High ligation and hernioplasty to 29 (45.3%) patients and hernioplasty using Zig maneuver to 35 (54.6%) patients were performed during the study.ResultsPostoperative wound infection was observed in 2 patients (6.8%) with high ligation and 1 (2.8%) patient with hernioplasty with Zig maneuver. Scrotal edema was detected in all the patients, which persisted until postoperative month 1. Recurrence was seen in 6 (20.6%) of 29 patients who operated using the high ligation method while it was seen in 2 (5.7%) of other 35 patients. None of the patients had testicular atrophy and/or iatrogenic undescended testis.ConclusionGiant inguinoscrotal hernias should be defined and evaluated as a group apart from classical inguinoscrotal hernias. Recurrence and morbidity rates were lower in patients who underwent hernioplasty using Zig maneuver.

Phase Diagram of 360° Domain Walls in Magnetic Rings

One method to increase bit density in magnetic memory devices is to use multi-state structures, such as a ferromagnetic nanoring with multiple domain walls (DWs), to encode information. However, there is a competition between decreasing the ring size in order to more densely pack bits and increasing it to make multiple DWs stable. This paper examines the effects of ring geometry, specifically inner and outer diameters (ODs), on the formation of 360° DWs. By sequentially increasing the strength of an applied circular magnetic field, we examine how DWs form under the applied field and whether they remain when the field is returned to zero. We examine the relationships between field strength, number of walls initially formed, and the stability of these walls at zero field for different ring geometries. We demonstrate that there is a lower limit of 200 nm to the ring diameter for the formation of any 360° DWs under an applied field, and that a high number of 360° DWs are stable at remanence only for narrow rings with large ODs.

NUEVO REGISTRO DE LA ESPECIE Cladopyxis hemibrachiata DEL GRUPO DINOFLAGENADO PARA LA RESERVA DE LA BIOSFERA DE SEAFLOWER, CARIBE COLOMBIANO

Los dinoflagelados son considerados como un grupo muy diverso, encontrados en la mayoría de los ambientes acuáticos, sin embargo, a pesar de la importancia de este grupo, son pocos los trabajos que se han hecho para el área del mar Caribe, siendo los registros más cercanos los reportados para el Golfo de México y la cadena submarina Vitória-Trindade en Brasil. En la presente nota se reporta por primera vez para el mar caribe colombiano la presencia de la especie de dinoflagelado Cladopyxis hemibrachiata Balech, en muestras colectadas en septiembre de 2017 en la Isla Cayo Serranilla (Reserva de biosfera Seaflower), mediante arrastres horizontales con una red cónica de 20 µm de tamaño de poro y diámetro del aro de 70 cm. Así mismo, se hicieron mediciones in situ de variables físicas y químicas del agua, cuyos datos obtenidos son típicos de aguas mesotróficas

Algorithm of calculation of focal parameters of profile electron beams, formed by the gas-discharge electron guns

An algorithm of calculation of the focal distance of a hollow conical electron beam, formed by high voltage glow discharge electron guns, as well as the calculation of the diameter and thickness of a focal ring of such a beam, are considered in the article. The proposed algorithm is based on the model of free moving of electrons in the anode plasma and formed on the base of the laws of electron optics with using the methods of discrete mathematics and minimax analysis. Obtained simulation results allow to find the important regularities, which characterized the dependencies of focal parameters of a hollow conical electron beam, formed by the high voltage glow discharge electron guns, on the constructive parameters of electrodes’ system of the electron gun.

Development and preliminary results of Xtrim-PET, a modular cost-effective preclinical scanner

We report on development of Xtrim-PET, a prototype low-cost preclinical PET system using high-density analog silicone photomultiplier (SiPM) arrays and pixelated scintillator LYSO:Ce crystals. Channel reduction method is employed to reduce 144 SiPM signals per detector block to 16 energy and 9 fast signals in the detector head. Using these signals, a Digital Front-End (DFE) board calculates energy, position, and time information of incident gamma photon and transmits data packets to a downstream Digital Coincidence Processing Unit (DCPU) in which the coincidence events are extracted in a fully pipelined digital processing fashion for maximum count throughput. The system consists of 10 detector blocks (detector head and DFE board), a DCPU board, and an acquisition computer. Prompt and delayed coincidence events are stored in list mode in the acquisition computer where first hand corrections are applied and 3D sinogram is generated in offline mode. Two-dimensional sinograms are then generated using single-slice rebinning algorithm and iterative image reconstruction methods are employed to generate the 3D image. The developed scanner works in room temperature without additional cooling system and has 180 mm ring diameter. Tomographic image resolution of 1.6, 1.7, and 1.8 mm FWHM was calculated along radial, tangential, and axial directions, respectively. Preliminary investigations were performed using NEMA image quality phantom in addition to rat cardiac and bone scans for preclinical evaluation of the scanner.

A reassessment of the proposed ‘Lairg Impact Structure’ and its potential implications for the deep structure of northern Scotland

The Lairg Gravity Low may represent a buried impact crater c . 40 km across that was the source of the 1.2 Ga Stac Fada Member ejecta deposit but the gravity anomaly is too large to represent a simple crater and there is no evidence of a central peak. Reanalysis of the point Bouguer gravity data reveals a ring of positive anomalies around the central low, suggesting that it might represent the eroded central part of a larger complex crater. The inner or peak rings of complex craters show a broadly consistent 2:1 relationship between ring diameter and total crater diameter, implying that the putative Lairg crater may be as much as 100 km across. This would place the crater rim within a few kilometres of the Stac Fada Member outcrop, a location inconsistent with the thickness and clast size of the ejecta deposit. We propose that the putative impact crater originally lay further east, substantially further from the Stac Fada Member than today, and was translocated westwards to its present location beneath Lairg during the Caledonian Orogeny. This model requires that a deep-seated thrust fault, analogous to the Flannan and Outer Isles thrusts, exists beneath the Moine Thrust in north–central Scotland.

Effect of confinement on the decay of vortex rings

The instances of vortex ring evolving in confined domains is observed in biological and engineering flows. The evolution of a vortex ring inside a non-axisymmetric confinement and the effect of this confinement on the decay of the ring is investigated in this paper. A square confinement is chosen for this purpose. The effect of confinement ratio (CR), defined as the ratio of the diameter of vortex ring to the size of confinement, is studied in detail. The asymmetry caused by the confinement on the ring is noted by measuring its properties on two different planes, namely the Y-plane and the diagonal plane. The asymmetry on the vortex ring is qualitatively observed to be dependent on CR.

The effect of simulated dust storm on wood development and leaf stomata in Quercus brantii L

Dust storms are increasingly threatening the forest ecosystem in Western Iran. Due to its coverage of vast area of Zagros forest, the Quercus brantii is at the front line of the attack. Most tree deaths in this forest are from this species. This study aims to investigate the effect of simulated dust on wood development and leaf stomata from seedlings of Persian oak. The oak seedlings were put in a chamber and dusted from 9 a.m. until 6 p.m. at three different days with an interval of 12 days. They were under three increasing concentrations of dust (5000, 7000, and 9000 mg/m3). Leaf and wood samples of about 10 seedlings were collected, and the leaf stomatal features, growth ring and vessel features of both treated and untreated seedlings were examined. The results showed no variations in stomatal features except for pore aperture. As for wood features, growth ring, vessel number and diameter considerably changed. In treated seedlings, the growth ring and vessel diameter were smaller and the number of vessels was higher than in the untreated seedlings. No detection of differences in stomatal features could be tracked due to the short-period of treatment. The usual seedlings’ annual growth could be altered by treatment affecting on both annual growth ring and vessel features. To sum up, it can be concluded that dust storm has strong effect on seedling’s growth as can limit wood formation

First record of Trichodina centrostrigeata Basson, Van As &amp; Paperna, 1983 (Ciliophora: Trichodinidae) from Oreochromis niloticus (Linnaeus, 1758) cultured in southeastern Mexico

Nile tilapia Oreochromis niloticus is one of the most economically important freshwater fish cultivated worldwide. Despite its importance and being one of the cichlid fish most studied from a parasitological point of view in Mexico, there are few studies about the ectoparasite protozoa that infect them. In this study, a total of 240 juvenile individuals of O. niloticus from an experimental culture (in Tabasco, Mexico) were examined to detect the presence of trichodinid parasites. Trichodinid parasites were impregnated with silver nitrate and stained with Harris´ hematoxylin solution for taxonomic evaluation. A disc-shaped trichodinid with a body diameter of 38 ± 3.3 μm adhesive disc diameter of 34 ± 3.3 μm and a denticulate ring diameter of 19 ± 2.1 μm was found. Trichodina centrostrigeata has been previously reported having specificity for cypriniform species, but in the present study, the Nile tilapia was reported as a new fish host and southeastern Mexico as a new geographical distribution for this parasite.

Mechanical characteristics of pine biomass of different sizes and shapes

In the present study, the mechanical properties of granular biomass of pine origin (sawdust, shavings, long shavings and pellets) were determined. The bulk and tapped densities were determined in a cylindrical chamber. The compacted density was measured, and the influence of the moisture content on this quantity was examined in a vane tester. The flowability and strength properties were determined using a direct shear tester (Jenike box) 210 mm in diameter and standard Schulze ring shear tester. The tests in the Jenike tester complied with the Eurocode 1 procedure for normal pressure (σn) of 15 and 30 kPa and speed of shearing of 0.17 mm s−1. Ring shear testing was conducted using a Schulze annular shear cell of 195 mm outer diameter. Tests were performed for 10 and 20 kPa pre-shear σn. A prototype vane tester was constructed for determining the torque, shear strength, and relaxation of a consolidated sample of granular biomass. σn was exerted by a pneumatic system with a rubber air spring and yoke. The torque and density were measured for moisture content in the range of 10–50% and for σn in the range of 5–30 kPa. The torque was observed to be affected by σn and the moisture content, whereas no relationship between the torque and the rotational speed was observed.