Present Setup Research Articles

Fine Motor Assessment in Upper Extremity Using Custom-Made Electronic Pegboard Test.

A fine motor test involves the manipulation of smaller objects with fingers, hands, and wrists. This test is an integral part of the evaluation of an upper extremity function. Nine Hole Peg Test (NHPT) is one among such tests which assess the ability to manipulate pegs with the thumb and finger. There is a need to develop a fine motor assessment tool which is reproducible and mimics closely the natural movement of hands. The aim of this work is to develop an electronic pegboard which is easy to administer and efficient in terms of time. Pegboard device is modified and standardized by (1) Adding electronic circuits to custom-made pegboard and programmed using a microcontroller (ATmega2560), (2) Following a specific sequence in placing and picking the pegs from the board, and (3) Using Infrared sensor and robust algorithm to ensure one peg movement at a time. The setup is administered on 15 healthy participants (nine females, six males aged between 21 and 80) and the outcome is compared with the results of traditional NHPT. Predefined sequence in moving the pegs and electronic timer features provide reliable results for repeated measurements and facilitate storing test score in a digital repository. This data could be used as reference data during the follow-up visits. The maximum difference between the measured timing between the present setup and traditional NHPT is about 6.7%. It is important to note that, due to inherent delay (response time) in the traditional NHPT, when compared to present setup the measured timing is always on the higher side. Nondependency on the manual stopwatch to record the time and hands-free of any wearable device are the advantages of the present setup.

Wick-free paradigm for high-performance vapor-chamber heat spreaders

In this study, a novel vapor chamber featuring wickless wettability-patterned components is designed, fabricated, and tested. This is the first phase-change heat transfer apparatus comprised entirely of wick-free elements that transport liquid by way of wetting forces generated by precise surface-wettability patterning. Our approach takes advantage of the phase-changing properties of water within a closed loop composed of two opposing, wickless wettability-patterned plates, one acting as an evaporator, and the other designed as a condenser. The plates feature different geometric wettability patterns, each especially designed/engineered to transform a flat rectangular copper plate to a functional component of a low-profile vapor chamber. The wettability pattern of the condenser facilitates spatially controlled dropwise and filmwise condensation and offers an optimal way to move the condensate through specifically built wedge tracks utilizing capillary forces. The wettability pattern laid on the evaporator enables the collection/accumulation and transport of the returning condensate fluid to the heat-input portion where evaporation must be strongest for maximum heat removal. Using this system, we effectively cooled a 0.9 cm2 heated area by spreading the heating power (∼200 W) over a 30× larger condenser area. The best performance metrics were thermal resistance 0.18 K/W at 10 W, in-plane thermal conductivity 1.17 kW/(m·K) at 22 W, and maximum heat flux ∼ 2.2 MW/m2. The present wick-free vapor-chamber heat-spreader apparatus is the first of its type and the simplicity of its design along with its moderate dimensions (making it light and thin) are important advantages that make this system well-suited for a wide range of thermal management applications.

A new look at distributed optimal output agreement of multi-agent systems

This paper studies the distributed optimal output agreement problem for multi-agent systems with the agents admitting the essential reference-tracking capability characterized by the well-known notion of system types. In the present system setup, the agents know only the gradient values of their corresponding local objective functions, and distributed optimizers are designed to generate reference signals for the agents. Under mild assumptions on the local objective functions and the connectivity between the agents, it is shown that the agents’ outputs can be steered to the global optimum of the total objective function as long as the system type of each agent is not less than one. A numerical example on the simultaneous formation and source seeking of a group of vertical take-off and landing (VTOL) vehicles is employed to verify the effectiveness of the proposed approach.

Inducing thermionic emission from lanthanum hexaboride probes in Magnum-PSI

For thermionic emission rates exceeding the incident plasma electron flux, recent theory proposes an inverse sheath regime, with promising properties for future application in fusion edge plasmas. With the aim of inducing thermionic emission in fusion-relevant plasma conditions, several lanthanum hexaboride probes were heated in the linear plasma generator Magnum-PSI. During exposures at low plasma power and additional pulsed laser heating, the probe’s floating potential was reduced by up to 12%, providing a possible indication of thermionic emission. However, these observations coincided with rapid erosion of probe material, attributed to enhanced lanthanum self-sputtering. During follow-up experiments with helium plasmas at electron temperatures around 1 eV, the lanthanum ion impact energy and sputtering yield were reduced, and rapid erosion was avoided, thus confirming the thesis of self-sputtering. A parameter scan of plasma power resulted in LaB 6 surface temperatures up to 2450 °C, exceeding the theoretical inverse sheath threshold temperature by over 300 °C. However, the probe’s floating potential did not deviate from reference measurements using a probe with high electronic work function, indicating absence of strong thermionic emission. This apparent discrepancy is attributed to the effects of probe surface modifications as observed during these experiments: impurity deposition, erosion and cavity formation. These modifications possibly affected the LaB 6 electronic work function, thereby keeping the inverse sheath threshold out of reach. In conclusion, although LaB 6 has one of the lowest work functions available, the inverse sheath threshold conditions could not be reached with the present setup in Magnum-PSI. Surface modifications thus do form a limiting factor for the application of LaB 6 in fusion-relevant plasma conditions. Moreover, the window of stable operation for LaB 6 in dense hydrogen plasmas is limited below ∼ 1.5 eV, and does not overlap with the conditions expected in the edge region of future fusion devices like ITER. • LaB 6 probes were heated up to 2450 °C under fusion-relevant plasma conditions. • Surface modifications limit the effective operation of powder-pressed LaB 6 . • Lanthanum self-sputtering in dense plasma conditions leads to rapid erosion. • The LaB 6 operation window does not overlap with ITER divertor conditions.

Biopharmaceutical-Type Chinese Hamster Ovary Cell Cultivation Under Static Magnetic Field Exposure: A Study of Genotoxic Effect.

The lack of a sufficient research base is the reason for the ongoing discussion regarding the genotoxic effect of magnetic field (MF) exposure on mammalian cell cultures. Chinese hamster ovary (CHO) suspension-type cells, which are widely used for biopharmaceutical production, are potentially subjected to an increased MF when cultivated in bioreactors equipped with bottom-placed magnetically coupled stirring mechanisms. The main challenge for conducting research in this field remains the availability of a suitable experimental setup that generates an appropriate MF for the raised research question. In the present study, a simple and cost-effective experimental setup was developed that generated a static MF, similar to what has been modeled in large-scale bioreactors and, at the same time, was suitable for experimental cell cultivation in laboratory conditions. The measured maximum magnetic flux density to which the cells were exposed was 0.66 T. To assess the possible genotoxic effect, cells were continuously subcultivated in laboratory petri dishes for a period of 14 days, corresponding to a typical duration of a biopharmaceutical production process in a conventional fed-batch regime. The genotoxic effect was assessed using the cytokinesis-block micronucleus assay with fluorescent staining. Results showed that a 0.66-T static MF exposure had no significant long-term effect on cell viability and chromosomal damage but demonstrated a short-term effect on cell apoptosis. Significant increase in nuclear bud formation was observed. These findings may encourage other researchers in future studies investigating cellular responses to MF exposure and contribute relevant data for comparison.

Effects of whole-body vibration training in a cachectic C26 mouse model

Targeted exercise combined with nutritional and pharmacological strategies is commonly considered to be the most optimal strategy to reduce the development and progression of cachexia. For COPD patients, this multi-targeted treatment has shown beneficial effects. However, in many, physical activity is seriously hampered by frailty and fatigue. In the present study, effects of whole-body-vibration-training (WBV) were investigated, as potential alternative to active exercise, on body mass, muscle mass and function in tumour bearing mice. Twenty-four male CD2F1-mice (6–8 weeks, 21.5 ± 0.2 g) were stratified into four groups: control, control + WBV, C26 tumour-bearing, and C26 tumour-bearing + WBV. From day 1, whole-body-vibration was daily performed for 19 days (15 min, 45 Hz, 1.0 g acceleration). General outcome measures included body mass and composition, daily activity, blood analysis, assessments of muscle histology, function, and whole genome gene expression in m. soleus (SOL), m. extensor digitorum longus (EDL), and heart. Body mass, lean and fat mass and EDL mass were all lower in tumour bearing mice compared to controls. Except from improved contractility in SOL, no effects of vibration training were found on cachexia related general outcomes in control or tumour groups, as PCA analysis did not result in a distinction between corresponding groups. However, analysis of transcriptome data clearly revealed a distinction between tumour and trained tumour groups. WBV reduced the tumour-related effects on muscle gene expression in EDL, SOL and heart. Gene Set Enrichment Analysis showed that these effects were associated with attenuation of the upregulation of the proteasome pathway in SOL. These data suggest that WBV had minor effects on cachexia related general outcomes in the present experimental set-up, while muscle transcriptome showed changes associated with positive effects. This calls for follow-up studies applying longer treatment periods of WBV as component of a multiple-target intervention.

A photoionized pulsed low-energy ion beam source for quantum state-to-state crossed ion-molecule scattering.

Here, we report the designand test of a pulsed low-energy ion beam source for crossed ion-molecule scattering studies. The ions are produced by laser photoionization based methods and thus can be prepared in well-defined quantum states. By using the combination of a double Einzel lenses setup and a specially designed shielding tube, a well spatially confined ion bunch with tunable kinetic energies in the range of 1.0-5.0eV and typical spreads of ∼150meV (full width at half maximum) can be formed in the center of a velocity-map imaging (VMI) stack. By combining it with a recently constructed three-dimensional VMI system, the present apparatus is readily available for quantum state-to-state crossed ion-molecule scattering studies.

Reduced Scale Experimental Modelling of Distributed Thermal Response Tests for the Estimation of the Ground Thermal Conductivity

The knowledge of the ground thermal properties, and in particular the ground thermal conductivity is fundamental for the correct sizing of the Ground Coupled Heat Pump (GCHP) plant. The Thermal Response Test (TRT) is the most used experimental technique for estimating the ground thermal conductivity. This paper presents an experimental setup aimed to realise a suitable scale prototype of the real borehole heat exchanger (BHE) and the surrounding ground for reduced scale TRT experiments. The scaled ground volume is realised with a slate block. Numerical analyses were carried out to correctly determine suitable geometric and operational parameters for the present setup. The scaled heat exchanger, inserted into the block, is created with additive technology (3D printer) and equipped with a central electrical heater along its entire depth and with temperature sensors at different radial distances and depths. Present measurements highlight the possibility to reliably perform a TRT experiment and to estimate the slate/ground thermal conductivity with an agreement of about +12% with respect to measurements provided by a standard commercial conductivity meter on proper cylindrical samples of the same material and onto 10 different portions of the slate block.

Non-Invasive in Vivo Quantification of Directional Dependent Variation in Mechanical Properties for Human Skin.

Skin is the body’s largest organ, and it shows non-linear and anisotropic behavior under the deformation. This behavior of the skin is due to the waviness and preferred orientation (in a particular direction) of collagen fibers. This preferred orientation of collagen fibers results in natural pre-tension and anisotropy of the skin. The knowledge of natural skin pre-tension and anisotropy is essential during incisions and surgery. The available suction-based devices quantify the anisotropy through the displacement field and cannot measure the stress-strain relation in particular directions. Therefore, in the current study, an in vivo full-field measurement suction apparatus was developed to measure the stress and strain of skin in all planar directions through a single experiment. First, this apparatus was tested on silicone substrates of known properties, and then it was used to test the skin of 12 human forearms. Further, to check the effect of hand stability on the measurements, the obtained results of the skin were compared with the results of a standard test performed in the same skin using a steady setup. The consistency between these two results confirms that the stability of the hand does not influence the measurements of skin properties. Furthermore, using the developed apparatus, the skin’s anisotropy and its relation with the Kraissl’s lines orientation was quantified by measuring the toe and linear moduli at an interval of one degree. The minimum and maximum values of the toe and linear moduli were 0.52 ± 0.09 and 0.59 ± 0.11 MPa, and 3.09 ± 0.47 and 5.52 ± 1.13 MPa, respectively. Also, the direction of maximum moduli was found almost similar to Kraissl’s lines’ orientation. These results confirm the contribution of skin pre-tension on the anisotropy of the skin. The present apparatus mimics the tissue expansion procedure, where observation of the test may be helpful in the selection of size and shape of the expander.

Interfacial Properties of a PEM Water Electrolysis Pt Electrode Probed by Operando Tender Ambient Pressure X-Ray Photoelectron Spectroscopy

The probe of the chemical, structural, and electronic properties at the electrode-electrolyte interfaces under operational conditions is critical for the mechanistic study and optimization of all the electrochemical systems and has therefore been at the center of numerous studies [1]. Soft X-ray Ambient pressure X-ray photoelectron spectroscopy (APXPS) has been known as a promising in-situ/operando technique, but its applications in the probe of a realistic solid/liquid interface under ambient conditions has been limited by the short inelastic mean free path (IMFP) of photoelectrons in the liquid medium. Here, inspired by prior work [2,3] and taking advantage of the synchrotron tender X-ray source (Beamline 9.3.1) at the Advanced Light Source of the Lawrence Berkeley National Laboratory [4], the IMFP can be significantly increased. A larger IMFP enables interfacial characterization under higher background pressures and through liquid overlayer greater than 30 nm in thickness. We have designed and built a graphene sealed operando electrolysis electrochemical cell that is compatible with an existing tender X-ray APXPS setup for the investigation of electrode-electrolyte interfaces under operational conditions. The present setup will be utilized to probe various systems involving solid/liquid interfaces, including but not limited to the interactions of ions, the solvation of salts, and electrocatalysis.In this work, the utilization of tender X-rays (2000 – 6000 eV) facilitates investigations of the electrode-electrolyte interface with a liquid-layer thickness of tens of nanometers, which can be preserved within the sandwiched region between the topmost graphene and the Pt nanoparticle loaded proton exchange membrane (PEM). In addition, the environmental water vapor pressure within the analysis chamber was kept at the water vapor pressure at 298 K (~15 Torr). The setup allows the study of a water splitting electrolyzer under real working conditions, where the electrocatalytic performance and the operando photoemission spectroscopy can be simultaneous investigated. As a proof-of-concept, Pt nanoparticle-catalyzed oxygen evolution reaction (OER) was investigated under operando conditions. The electrochemistry and detailed analysis of the photoemission spectra demonstrating the evolution of the chemical, structural, and electronic properties at the H2O/Pt interface under the influence of external electrical field will be presented.

Effectiveness of Virtual Teaching Tools on Knowledge and Practice of Biomedical Waste Management among Housekeeping Staff of a Tertiary Care Centre, Rishikesh

Background: The present bio-medical waste (BMW) practices, setup, and framework explored that almost 82% of primary, 60% of secondary, and 54% of tertiary health-care facilities had no trustworthy BMW management system. This study aimed to improve the knowledge and practice of BMW management among housekeeping staff of a tertiary care center, Rishikesh. Materials and Methods: One group pre-test post-test quasi-experimental study was conducted on 139 housekeeping staff. A self-structured knowledge questionnaire and practice checklist through the interview method was used for data collection. Virtual teaching tools (video about BMW management and e-pamphlet) were developed for the study and used. Results: After the intervention, in post-test it was found that the majority of participants had excellent knowledge (111; 79.8%), some (24; 17.3%) had good, and only few (4; 2.9%) had moderate knowledge. None of the participants were found to have poor knowledge after the intervention. There is significant difference in pre-existing (15.89 ± 2.49) and post-test (21.20 ± 4.61) knowledge score, pre-existing practice (21.67 ± 2.13), and post-test (24.95 ± 2.42) practice. There was association between educations their work area with knowledge and significant relationship between work area and past training programs with practice. There is a significant correlation between pre-test knowledge and practice (p=0.00) and post-test knowledge and practice (P = 0.01). Conclusion: It is evident that a virtual teaching tool that comprises video and e-pamphlet is useful in improving the knowledge and practice of housekeeping staff on BMW management.

Common veterinary practice in small animal anesthesia - an online survey among small animal practitioners in Europe

Survey concerning the situation of small animal anesthesia in Europe and assessment of the compliance with the guidelines of the AVA (American Society of Anesthesiologists) and the DVG specialty group VAINS (Veterinary Anesthesia, Intensive Care, Emergency Medicine, and Pain Management). A link to an online survey with questions concerning anesthesia management (topics include demographics, equipment, monitoring, thermal management, pre-anesthetic examination, anesthetic protocol, and others) was sent to small animal practitioners in several countries. A total of 767 evaluable questionnaires came from Germany (n = 343), Austria (n = 216), Switzerland (n = 83), the United Kingdom (n = 38), France (n = 25), Hungary (n = 25), Scandinavia (n = 23), and "other countries" (n = 11). On average, 91 % of respondents complied with the AVA guideline and 58 % complied with the VAINS specialty group guideline even before its publication. Practices/clinics with higher staff possessed superior equipment, and practices/clinics performing higher numbers of anesthesias per week were more likely to implement "good preliminary examination." Although the guidelines were found to be implemented to a certain degree, the presented study reveals a potential for optimization of the anesthesia regime in many practices/clinics, e. g. by improving the equipment or allowing for better use of present apparatus.

Accelerated mass transfer enhancement by density-driven natural convection

ABSTRACT The prolonged heat and mass transfer can be enhanced by orders of magnitude that originate from the natural convection. This work examines the mass transfer enhancement in the fluid motion inside a horizontal capillary. In the experimental setup, dye or polystyrene (PS) in aqueous sucrose is taken on one side, and water is on the other side. The main purpose of employing two different systems (i.e. dye and PS) is that it can confirm whether the enhanced mass transfer is with only nanoparticles or it can be possible without nanoparticles in the presence of solute concentration gradients in a fluid. It is demonstrated that the induced flow is due to natural convection attributed to the density-driven flow. The induced flow in the present setup may open up various additional applications for the systems where rapid mixing is important, for instance, rapid formation of drug carriers.

Geology and sedimentary environment of the Surma Group of rocks, Bandarban anticline, Bandarban, Bangladesh

The study illustrates the effect of tectonics, climate, and relative sea-level change on the depositional process of the Miocene Bhuban and Boka Bil Formation of Bengal Basin. Outcrop sediments of five transverse sections exposed along the axial zone of Bandarban anticline were studied. Twelve lithofacies such as Gm, Gms, Sm, ST, Sp, Sr, Sl, Sf, Sll, Fw, Fl and Fm have been identified within the successions and grouped into (i) turbidite generated, (ii) outer fan distal lobe basin plain and (iii) tide-influenced facies association. The analyses reveal that the Bhuban Formation was turbidite- generated that deposited below the continental shelf-slope environment. The Lower Bhuban Member consists of gray to brownish-gray calcareous sandstone with shale deposited under the channelized lobe of submarine fan. The Middle Bhuban Member dominated by black shale-siltstone deposited in distal turbidite lobe due to change the flow regime. The Upper Bhuban Member consists of yellow to yellowish gray, coarse to medium-grained sandstone-siltstone with black shale that deposited under channelized to nonchannelized lobes of submarine fan. The increasing sedimentation during the formation of the Upper Bhuban Member can be caused by increased the intensity of the Asian Monsoon that carried huge sediment from the Himalaya. The Boka Bil Formation was deposited under estuary to tidal flat environment. The area was uplifted during and/or after subduction of the Indian Plate beneath the Burmese Plate. The monsoonal intensity enhances sedimentation that moved prograding delta towards the south. These processes shifted depositional environment from continental shelf-slope to marginal shallow marine during deposition of the Boka Bil Formation. The continental slope aligned east-west direction and sediments likely derived from the Himalaya and Trans-Himalaya in the present geographical setup during deposition of the sediments.

Analysis of the liquids composition by the sound produced by their heating

When a liquid is heated and the power of the heater is high enough (about 1MW/m2), bubbles are formed at the surface of the heater. Their expansion and collapse are the source of a specific sound, known to everybody who uses a kettle to prepare water for tea or coffee. The main goal of this study is to investigate whether it is possible to judge about the composition of the heated liquid by this sound. A specialized experimental set up is assembled and a systematic study of all known factors, influencing the sound is carried out. It is found out that the most crucial parts of the set up are the container for the liquids and the heater. They are discussed in detail and considerations for further improvements are given. It is demonstrated that with the present apparatus it is possible to detect changes in the sound spectrum when changing the composition of the liquid. For example, one can distinguish between pure water and water with less than 0.1% of ethanol. Along with admixtures of different alcohols, experiments with a soap solution in water and carbonated water are performed.

Analytical and Experimental Investigation of a Plate Fin Heat Exchanger at Cryogenics Temperature

Plate-fin heat exchangers provide a broad range of applications in many cryogenic industries for liquefaction and separation of gasses because of their excellent technical advantages such as high effectiveness, compact size, etc. Correlations are available for the design of a plate-fin heat exchanger, but experimental investigations are few at cryogenic temperature. In the present study, a cryogenic heat exchanger test setup has been designed and fabricated to investigate the performance of plate-fin heat exchanger at cryogenic temperature. Major parameters (Colburn factor, Friction factor, etc.) that affect the performance of plate-fin heat exchangers are provided concisely. The effect of mass flow rate and inlet temperature on the effectiveness and pressure drop of the heat exchanger are investigated. It is observed that with an increase in mass flow rate effectiveness and pressure drop increases. The present setup emphasis the systematic procedure to perform the experiment based on cryogenic operating conditions and represent its uncertainties level.

Bragg coherent diffraction imaging allowing simultaneous retrieval of three-dimensional shape and strain distribution for 40–500 nm particles

We report the improvement of an apparatus for Bragg coherent X-ray diffraction imaging (Bragg-CDI) at BL22XU in SPring-8 to expand the applicable particle size and the application of the Bragg-CDI technique for Pd and ferroelectric barium titanate (BaTiO3) fine crystals with particle sizes of 40–500 nm. Preparing a vacuum environment around the sample enabled us to obtain the high-contrast diffraction pattern of a 40 nm particle. The reconstructed three-dimensional image showed the outer shape, size, and internal phase (strain) for a single particle. A single 500 nm BaTiO3 particle showed a straight and sharp antiphase-boundary shape, whereas smaller BaTiO3 particles showed different phase boundary shapes. The present Bragg-CDI apparatus, thus, allows the observation of the outer shape, size, and inner phase distribution for a single particle with a size of 40–500 nm.

Operando structural investigations of thermoelectric materials

Operando characterization provides direct insight into material response under application conditions and it is essential to understand the stability limits of thermoelectric materials and their decomposition mechanisms. An operando setup capable of maintaining a thermal gradient while running DC current through a bar-shaped sample has been developed. Under operating conditions, X-ray scattering data can be measured along the sample to obtain spatially resolved structural knowledge in concert with measurement of electrical resistance and the Seebeck coefficient. Here thermoelectric β-Zn4Sb3, which is a mixed ionic–electronic conductor, is studied, and a significant temperature dependence of the Zn migration is directly observed. Measurements with the thermal gradient applied either along or opposite to the DC current establish that the ion migration is an electrochemical effect rather than a thermodiffusion. Consideration of only the applied critical voltage or current density is insufficient for deducing the stability limits and structural integrity of materials with temperature-dependent ion mobility. The present operando setup is not limited to studies of thermoelectric materials, and it also lends itself to studies of, for example, ion diffusion in solid-state electrolytes or structural transformations in solid-state reactions.

Spin‐Polarization and Resonant States in Electronic Conduction through a Correlated Magnetic Layer

The transmission through a magnetic layer of correlated electrons sandwiched between noninteracting normal‐metal leads is studied within model calculations. The linear regime in the framework of the Meir–Wingreen formalism is considered, according to which the transmission can be interpreted as the overlap of the spectral function of the surface layer of the leads with that of the central region. By analyzing these spectral functions, it is shown that a change in the coupling parameter between the leads and the central region significantly and nontrivially affects the conductance. The role of band structure effects for the transmission is clarified. For a strong coupling between the leads and the central layer, high‐intensity localized states are formed outside the overlapping bands, while for weaker coupling this high‐intensity spectral weight is formed within the leads’ continuum band around the Fermi energy. A local Coulomb interaction in the central region modifies the high‐intensity states, and therefore the transmission. For the present setup, the major effect of the local interaction consists in shifts of the band structure because any sharp features are weakened due to the macroscopic extension of the layers.

Application of fracture mechanics for the characterization of poly(vinyl chloride) pipes. II. Evaluation of a ring‐type specimen for fracture mechanics testing

AbstractAn unplasticized poly(vinyl chloride) (U‐PVC) pipe sample used in infrastructure applications in Brazil (nominal diameter DN 100, outside diameter 110 mm) was evaluated according to different fracture mechanics methodologies, including essential work of fracture (EWF) and other fracture toughness parameters such as the stress intensity factor and plane strain energy release rate . This pipe sample was also tested for the quality of processing (degree of gelation) via differential scanning calorimetry (DSC) and tensile strength. The comparative evaluation of different specimen configurations—curved specimens in three‐point bending (CTPB) and full rings in tension (SNRT), in thicknesses varying from 5 to 30 mm, showed initial evidence of the suitability of ring‐type specimens for the evaluation of EWF and . Results also indicate that the full ring geometry, at least in the present experimental setup, presents some drawbacks probably due to the storage of large amounts of elastic energy throughout the test. This fact leads to relevant deviations in both load–displacement behavior and results for strain energy release rate (), and the results found here will guide future research using full and split rings in different loading modes and improved experimental setups. It was also confirmed that the value of , determined by a modified Charpy test, is independent of the type of specimen tested, as long as the test mode and specimen width are the same. Both the experimental value of and the estimated value for the plane strain stress intensity factor () showed excellent agreement with values reported for other U‐PVC compositions.