Quantification Of Stress Research Articles

Quantification of Oscillatory Shear Stress from Reciprocating CSF Motion on 4D Flow Imaging.

Oscillatory shear stress could not be directly measured in consideration of direction, although cerebrospinal fluid has repetitive movements synchronized with heartbeat. Our aim was to evaluate the important of oscillatory shear stress in the cerebral aqueduct and foramen magnum in idiopathic normal pressure hydrocephalus by comparing it with wall shear stress and the oscillatory shear index in patients with idiopathic normal pressure hydrocephalus. By means of the 4D flow application, oscillatory shear stress, wall shear stress, and the oscillatory shear index were measured in 41 patients with idiopathic normal pressure hydrocephalus, 23 with co-occurrence of idiopathic normal pressure hydrocephalus and Alzheimer-type dementia, and 9 age-matched controls. These shear stress parameters at the cerebral aqueduct were compared with apertures and stroke volumes at the foramen of Magendie and cerebral aqueduct. Two wall shear stress magnitude peaks during a heartbeat were changed to periodic oscillation by converting oscillatory shear stress. The mean oscillatory shear stress amplitude and time-averaged wall shear stress values at the dorsal and ventral regions of the cerebral aqueduct in the idiopathic normal pressure hydrocephalus groups were significantly higher than those in controls. Furthermore, those at the ventral region of the cerebral aqueduct in the idiopathic normal pressure hydrocephalus group were also significantly higher than those in the co-occurrence of idiopathic normal pressure hydrocephalus with Alzheimer-type dementia group. The oscillatory shear stress amplitude at the dorsal region of the cerebral aqueduct was significantly associated with foramen of Magendie diameters, whereas it was strongly associated with the stroke volume at the upper end of the cerebral aqueduct rather than that at the foramen of Magendie. Oscillatory shear stress, which reflects wall shear stress vector changes better than the conventional wall shear stress magnitude and the oscillatory shear index, can be directly measured on 4D flow MR imaging. Oscillatory shear stress at the cerebral aqueduct was considerably higher in patients with idiopathic normal pressure hydrocephalus.

Design of a Unique Device for Residual Stresses Quantification by the Drilling Method Combining the PhotoStress and Digital Image Correlation.

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.

Solid-state cladding on thin automotive sheet metals enabled by additive friction stir deposition

• Additive friction stir deposition enables good cladding on 1.4 mm-thin substrates. • The reinforced structure is characterized by good formability and high strength. • The mechanical forces from the tool cause no local buckling in the thin substrates. • The residual stress and mismatch strain are first quantified for this new process. • The maximum tensile stress is around 40 MPa and the mismatch strain is 7.37 × 10 - 4 . Additive friction stir deposition is an innovative solid-state additive manufacturing process that creates near-net-shape 3D components based on deformation bonding rather than melting and solidification. Here, we employ this process for selective cladding on thin Al-Mg-Si sheet metals and evaluate its feasibility for automotive manufacturing based on the cladding quality and substrate distortion. We show that under optimal conditions, additive friction stir deposition can produce high-quality cladding without surface or interface porosity even if the substrate is as thin as 1.4 mm. In addition, the high strength and good formability of the original Al-Mg-Si substrate are preserved in the post-cladding reinforced structure, which exhibits an ultimate tensile strength of 250 MPa and an elongation of 30 %. Despite the mechanical forces imposed by the tool during deposition, no local buckling or wrinkling is observed in the thin substrate. During cooling, however, in situ monitoring shows that mild, global substrate distortion gradually develops. Upon unclamping, the cladding-on-plate system reconfigures itself to minimize the potential energy, leading to an anticlastic curvature. Based on the curvature measurement and classical lamination theory, this work provides the first quantification of the residual stress caused by this newly-developed additive technology, in which the maximum tensile stress is estimated to be around 40 MPa in the rectangular reinforced structure and the interface mismatch strain is 7.37 × 10 −4 . Both values are low thanks to the solid-state nature of the process.

Calcium as a reliable marker for the quantitative assessment of endoplasmic reticulum stress in live cells

Calcium (Ca2+) is an essential mineral of endoplasmic reticulum (ER) luminal biochemistry because of the Ca2+ dependence of ER-resident chaperones charged with folding de novo proteins that transit this cellular compartment. ER Ca2+ depletion reduces the ability of chaperones to properly fold the proteins entering the ER, thus leading to an accumulation of misfolded proteins and the onset of a state known as ER stress. However, not all conditions that cause ER stress do so in a manner dependent on ER Ca2+ depletion. Agents such as tunicamycin inhibit the glycosylation of de novo polypeptides, a key step in the maturation process of newly synthesized proteins. Despite this established effect of tunicamycin, our understanding of how such conditions modulate ER Ca2+ levels is still limited. In the present study, we report that a variety of ER stress–inducing agents that have not been known to directly alter ER Ca2+ homeostasis can also cause a marked reduction in ER Ca2+ levels. Consistent with these observations, protecting against ER stress using small chemical chaperones, such as 4-phenylbutyrate and tauroursodeoxycholic acid, also attenuated ER Ca2+ depletion caused by these agents. We also describe a novel high-throughput and low-cost assay for the rapid quantification of ER stress using ER Ca2+ levels as a surrogate marker. This report builds on our understanding of ER Ca2+ levels in the context of ER stress and also provides the scientific community with a new, reliable tool to study this important cellular process in vitro.

Mass spectrometry-based serum lipidomics strategy to explore the mechanism of Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves in the treatment of ischemic stroke

Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves (ESL) were reported to have neuroprotective function and are also used to treat cranial and cerebral traumas as a traditional Chinese medicine and food herbage plant. However, there has been no previous study on ESL treatment for stroke at the level of lipid disorders. To clarify the mechanism of ESL in treating ischemic stroke, this study was carried out from 3 aspects, namely, the regulation of lipid disorders, protection of the nervous system, as well as anti-inflammatory and antioxidant actions. This study established a lipidomics research strategy that was developed by UPLC-Q-TOF/MS analysis. The quantification of neurotransmitters in the serum and brain tissue of rats was performed using UPLC-TQ/MS. Also, we quantified the oxidative stress and inflammatory reaction by measuring the contents of SOD, MDA, TNF-α, IL-6, and IL-10 via the ELISA kits for serum and brain tissue. According to UPLC-Q-TOF/MS-based lipidomics analysis, 27 lipidomics biomarkers were identified in this study, including PC, PE, SM, and TG, which were distributed in various lipid metabolic pathways, including glycerophospholipid, linoleic acid, alpha-linolenic acid, glycerolipid, sphingolipid, and arachidonic acid metabolism pathways. By reversing the changes in the lipid content caused by the disease, ESL has a therapeutic effect on ischemic stroke. Furthermore, quantitative results of neurotransmitters indicated that they can be regulated by ESL. Finally, the results of ELISA showed that ESL can treat ischemic stroke to a certain extent by reducing the oxidative and inflammatory damage. Therefore, ESL may play a therapeutic role in the treatment of ischemic stroke in different ways. This research preliminarily revealed the mechanism of ESL in the treatment of ischemic stroke and provided support for the further application of ESL.

The effect of ultrafiltration transmembrane permeation on the flow field in a surrogate system of an artificial kidney

Abstract Renal Replacement Therapies generally associated to the Artificial Kidney (AK) are membrane-based treatments that assure the separation functions of the failing kidney in extracorporeal blood circulation. Their progress from conventional hemodialysis towards high-flux hemodialysis (HFHD) through the introduction of ultrafiltration membranes characterized by high convective permeation fluxes intensified the need of elucidating the effect of the membrane fluid removal rates on the increase of the potentially blood-traumatizing shear stresses developed adjacently to the membrane. The AK surrogate consisting of two-compartments separated by an ultrafiltration membrane is set to have water circulation in the upper chamber mimicking the blood flow rates and the membrane fluid removal rates typical of HFHD. Pressure drop mirrors the shear stresses quantification and the modification of the velocities profiles. The increase on pressure drop when comparing flows in slits with a permeable membrane and an impermeable wall is ca. 512% and 576% for $ \mathrm{CA}22/5\%{\mathrm{SiO}}_2 $ and $ \mathrm{CA}30/5\%{\mathrm{SiO}}_2 $ membranes, respectively.

Fleet Asset Management Opportunities Arising from Transient Monitoring of Power Transformers and Shunt Reactors

Power transformers and shunt reactors are strategic assets for every system operator and their downtime should be kept as low and controlled as possible. During their multi-decade service life, they are regularly exposed to transient overvoltages. These situations stress their insulation systems and can cause accelerated deterioration and aging. Since the shapes of these overvoltages are usually unknown, an additional approach to assessing the health index can be realized using monitoring systems with transient recorders. Analyzing the transient overvoltages using frequency domain severity factor, a quantification of additional stress on the transformer’s/shunt reactor’s insulation can be given. This can help in assessing the current state of the insulation system and can lead to more advanced fleet asset management.

The Potential Benefit of Monitoring Oxidative Stress and Inflammation in the Prevention of Non-Communicable Diseases (NCDs).

The significant increase in worldwide morbidity and mortality from non-communicable diseases (NCDs) indicates that the efficacy of existing strategies addressing this crisis may need improvement. Early identification of the metabolic irregularities associated with the disease process may be a key to developing early intervention strategies. Unhealthy lifestyle behaviours are well established drivers of the development of several NCDs, but the impact of such behaviours on health can vary considerably between individuals. How can it be determined if an individual’s unique set of lifestyle behaviours is producing disease? Accumulating evidence suggests that lifestyle-associated activation of oxidative and inflammatory processes is primary driver of the cell and tissue damage which underpins the development of NCDs. However, the benefit of monitoring subclinical inflammation and oxidative activity has not yet been established. After reviewing relevant studies in this context, we suggest that quantification of oxidative stress and inflammatory biomarkers during the disease-free prodromal stage of NCD development may have clinical relevance as a timely indicator of the presence of subclinical metabolic changes, in the individual, portending the development of disease. Monitoring markers of oxidative and inflammatory activity may therefore enable earlier and more efficient strategies to both prevent NCD development and/or monitor the effectiveness of treatment.

Quantification of elastic stresses for structurally distorted 90° very thin-walled pipe bends under in-plane bending

PurposeElastic stress solutions are required in the field of fracture mechanics and the analysis of creep failure. The published precise elastic solutions are not addressing the influence of the manufacturing process induced, inevitable cross sectional deviations called ovality and thinning. The influence of ovality on plastic limit and collapse loads are reported in literature. Hence, it is important to study the combined effect of ovality and thinning on elastic stresses of bends.Design/methodology/approachThis paper relies on elastic finite element evolutions of stress components– longitudinal membrane stress, longitudinal bending stress, circumferential membrane stress and circumferential bending stresses. Based on the results, the coefficients for the equations are also obtained through the regression analysis.FindingsNew analytical solutions are prescribed to estimate the elastic stresses at the mid-section of the 90° very thin-walled bend with ovality and thinning, when subjected to in-plane bending moment. The ovality has significant influence on elastic stress whereas the thinning is not so. The proposed equations give an accurate estimation of elastic stresses at the mid-section of the bend with the incorporation of the parameters, namely R/rm, rm/t and ovality.Research limitations/implicationsThe influence of shape imperfections, namely ovality and thinning on elastic stress of 90° very thin-walled bends having rm/t > 20, subject to in-plane bending moment is proposed.Originality/valueThe influence of shape imperfections, namely ovality and thinning, on elastic stress of 90° very thin-walled bends with rm/t > 20, subject to in-plane bending moment is proposed.

Hours of occurrence of daily extreme air temperature and relative humidity in Santa Maria, RS

This study aimed to determine the most frequent occurrence times of daily extremes of air temperature and relative humidity in Santa Maria, RS, Brazil. Hourly data from 2002 to 2019 were obtained from an automatic weather station belonging to INMET. The relative frequencies of the times of occurrence of the daily minimum and maximum air temperatures were calculated for each month. The results allowed knowing the times of occurrence of the daily maximum and minimum air temperatures and relative humidity in Santa Maria, RS, Brazil. Thus, it is possible to obtain greater accuracy in the estimation of chill hours, duration of vernalization periods, and in the quantification of stresses caused by inadequate values of these variables in agriculture. The daily minimum air temperature is most frequently recorded at 7:00 a.m., varying from 6:00 a.m. to 8:00 a.m. throughout the year. The daily maximum air temperature occurs most frequently at 4:00 p.m., while in December and January, it is delayed to 5:00 p.m. The daily maximum relative air humidity occurs most frequently at 7:00 a.m., varying from 7:00 a.m. to 9:00 a.m. throughout the year. The daily minimum relative air humidity, on the other hand, occurs most frequently at 5:00 p.m., varying from 4:00 p.m. to 6:00 p.m. in the different months of the year.

Quantification of residual stress governing the spin-reorientation transition (SRT) in amorphous magnetic thin films

Soft magnetic thin films with in-plane uniaxial magnetic anisotropy are of significant importance for a broad range of technological applications, including high-frequency power conversion. In-plane uniaxial anisotropy in amorphous films is of particular interest for ultra-low materials loss and MHz frequency operations. The present work is focused on one of the fundamental mechanisms, i.e., residual stress, that can negate the uniaxial anisotropy in amorphous films by engendering perpendicular magnetisation and hence, undermining the soft magnetic performance. It is quantified how the nature of residual stress, compressive or tensile, transforms the magnetisation from an in-plane to an out-of-plane configuration, also well-known as spin-reorientation transition (SRT). A correlation between engineered residual stress in multilayer stacks, induced by the uneven expansion of metallic/dielectric layers following a thermal-shock scheme, and SRT mechanism demonstrates tensile stress inside the films undermines the soft magnetic performance. We suggest the magnetic softness can be retained by eluding sources of tensile stress during fabrication or post-processing of the amorphous films.

Quantification of water stress induced within-field variability of carbon dioxide fluxes in a sugar beet stand

Net ecosystem exchange of carbon dioxide (NEE) and soil respiration at field scale can exhibit considerable spatial variability linked to the heterogeneity of soil properties and state variables. In this study, we measured NEE with the eddy covariance (EC) method in a sugar beet field characterized by high spatial variability in soil physical properties. We further measured NEE and soil respiration by chambers as well as soil water content and temperature at 18 locations within the field.Spatially averaged chamber-measured NEE showed good agreement to the EC-based data. During a dry period high spatial variation of within-field NEE was detected with the chamber method. The coefficient of variation was on average 0.57 during the dry period, with a maximum of 0.72. Based on the depth-specific soil water content measurements the AgroC ecosystem model was inverted for soil hydraulic properties at each of the 18 locations, where soil water content was measured. Analyzing the model results revealed that root water uptake stress was the main driver of spatial and temporal variability in crop development and NEE, whereby the soil coarse material fraction (gravel content) and thickness of the layer above a gravel dominated soil layer were identified as the main influencing soil properties.The chamber-measured NEE and the flux footprint analysis showed that particularly during periods of severe root water uptake stress EC-based measurements would be prone to biases. A combination of the footprint model with the AgroC ecosystem model estimated a bias of 14 % for the dry period and a vegetation period bias of 6 % in relation to the average CO2 flux.

Quantification of principal horizontal stresses inside a tunnel: An application of Fracture induced Electromagnetic Radiation (FEMR) technique in the Darjeeling-Sikkim Himalayas

Characterization of recent stresses, delineation of the locations of active faults/landslide prone slip planes and forecasting earthquakes are some of the emerging applications of the Fracture Induced Electromagnetic Radiation (FEMR) technique. It is believed that such radiation is polarized along the direction of maximum compression and proportional to the maximum applied shear stress. In this paper, we have demonstrated the use of the FEMR technique to calculate the magnitude and directions of principal horizontal stresses inside a tunnel of ~240 m length over a hilly road between Jorethang and Mayong near the village of Miyong in Sikkim, India by taking 11 “cross-sectional” measurements using a portable FEMR recording device called ANGEL-M. Although a reverse stress regime is obvious and established over the Himalayas, the results show a normal stress regime prevailing over this shallow, near-surface region of the tunnel and the direction of maximum shear stress changes along the tunnel length. The results were explained with the aid of a simple clay analogue model where normal reactivation of a thrust plane with changing dips was simulated. With this communication, we hope to encourage scientists and engineers to deploy the FEMR technique which is lesser known but quicker, non-destructive, cheaper, and more accessible than conventional methods in evaluating tunnel safety by calculating shallow stresses locally modified inside a tunnel.

Distortion and residual stresses in thick plate weld joint of austenitic stainless steel: Experiments and analysis

Abstract The present work aims to evaluate distortion and residual stresses in thick plate weld joints of austenitic stainless steel. Quantification of residual stresses in thick austenitic stainless steel weld joint is important because it is not desirable to carry out stress relieving after welding owing to the susceptibility to sensitization in the heat-affected zone. Therefore, systematic studies were carried out to predict and measure distortion and residual stresses in the austenitic stainless steel plate weld joint. Variables influencing the generation of residual stresses such as heat input, welding speed, constraints during welding were considered. 20 mm thick plate weld joint of austenitic stainless steel material was prepared using gas tungsten arc welding (GTAW) in unclamped condition and distortions were measured during welding after each pass. Sub-surface and through-thickness residual stresses were measured using blind hole drilling (BHD) and deep hole drilling (DHD) techniques respectively. Thereafter, the weld joint was modeled using the finite element method and analyzed for residual stresses and distortions. Thermal analysis was carried out using actual welding parameters and temperature-dependent material properties to generate temperature profile and compare it with the measured values. The temperature profile along with necessary boundary conditions was used for structural analysis to obtain distortion and residual stresses. Experimental and finite element analysis results for distortion and residual stresses compare well. Details of the experimental and numerical analysis results of distortion and residual stresses for thick section plate weld joints have been discussed in this paper. Also, the effects of differences in yield strengths of weld and base metals on distortion and residual stress results have been brought out.

Analysis of ABC1 protein family members in Lepidium apetalum seeds and the expression of LaAbc1 in seedlings in response to abiotic stresses

To study the biological function of activity of bcl complex (ABC1) proteins in Lepidium apetalum Willd., genes encoding ABC1 family proteins were identified from the seed transcriptome. The sequence most closely related to germination at a low temperature was selected and gene expressions in response to low temperature stress further studied. The results show that 21 ABC1 genes were expressed in seeds germinating at the low temperature: 4 genes were upregulated, 6 were downregulated, and 11 were not significantly different from controls. The results of fluorescence quantification of the low-temperature stress on the seedlings of 7-d-old L. apetalum showed that seven genes were up-regulated, six genes were down-regulated, and eight genes had no significant difference. Real-time quantitative PCR results show that under the low temperature stress, the expression of the LaAbc1-3 gene increased, but its expression decreased after some time. The expression of this gene increased again after removing the low temperature stress. The expression of LaAbc1-21 gene in L. apetalum seedlings showed a trend of decreasing first and then increasing. The LaAbc1-3 gene was insensitive to salt stress. Expression of the LaAbc1-21 gene was significantly up-regulated during the salt stress. Under osmotic stress, the expression of the LaAbc1-3 gene was down-regulated, and the expression was negatively correlated with polyethylene glycol (PEG-6000) concentration. Under the PEG-6000 treatment, the expression of the LaAbc1-21 gene was significantly up-regulated, and the expression was positively correlated with concentration. These results provide a basis for further analysis of the role of the ABC1 genes in the stress resistance of L. apetalum.

Comparison of different measures to monitor week-to-week changes in training load in high school runners

Training load is commonly used to monitor training stress and is the product of external and internal physiological loads experienced by an athlete. With emerging wearable technology, it is possible to evolve existing external load measurement from duration or distance to runner-specific biomechanical data, which when combined with existing measures of internal load such as session rating of perceived exertion (sRPE), may improve the quantification of training stress. This study compared week-to-week changes in training duration with different training loads obtained from common and more individualized measures of external load. The training of nine male high school cross-country runners from the same team undertaking the same training program was monitored for two consecutive weeks. This two-week cycle included a “coach-prescribed” low and high training load week. Training loads were calculated with sRPE and external load measures including: duration (minutes), Step Count, “Bone Stimulus” (IMeasureU), and cumulative vertical force. Weekly distances (in miles) were also measured. Between-week percent change (%Δ) was compared among training loads and minutes using paired t-tests and Cohen’s d effect size. Different %Δ were found between sRPExMinutes (%Δ=65 ± 25%; p = 0.002, d = 1.83), sRPExStep Count (%Δ=66 ± 31%; p = 0.006, d = 2.06), sRPExForce (%Δ=66 ± 29%; p = 0.002, d = 1.91), and miles (%Δ=28 ± 13%; p = 0.019, d = 0.71) compared to minutes (%Δ=20 ± 8%). These findings highlight that only using weekly volume can greatly misrepresent changes in training stress in runners. We therefore encourage coaches and practitioners to consider training monitoring approaches beyond just weekly distance or duration. Simple measures of training load that include duration and sRPE might be sufficient.

Highly accelerated aortic 4D flow MRI using compressed sensing: Performance at different acceleration factors in patients with aortic disease.

To systematically assess the feasibility and performance of a highly accelerated compressed sensing (CS) 4D flow MRI framework at three different acceleration factors (R) for the quantification of aortic flow dynamics and wall shear stress (WSS) in patients with aortic disease. Twenty patients with aortic disease (58 ± 15 y old; 19 M) underwent four 4D flow scans: one conventional (GRAPPA, R = 2) and three CS 4D flows with R = 5.7, 7.7, and 10.2. All scans were acquired with otherwise equivalent imaging parameters on a 1.5T scanner. Peak-systolic velocity (Vmax ), peak flow (Qmax ), and net flow (Qnet ) were quantified at the ascending aorta (AAo), arch, and descending aorta (DAo). WSS was calculated at six regions within the AAo and arch. Mean scan times for the conventional and CS 4D flows with R = 5.7, 7.7, and 10.2 were 9:58 ± 2:58 min, 3:40 ± 1:19 min, 2:50 ± 0:56 min, and 2:05 ± 0:42 min, respectively. Vmax , Qmax , and Qnet were significantly underestimated by all CS protocols (underestimation ≤ -7%, -9%, and -10% by CS, R = 5.7, 7.7, and 10.2, respectively). WSS measurements showed the highest underestimation by all CS protocols (underestimation ≤ -9%, -12%, and -14% by CS, R = 5.7, 7.7, and 10.2). Highly accelerated aortic CS 4D flow at R = 5.7, 7.7, and 10.2 showed moderate agreement with the conventional 4D flow, despite systematically underestimating various hemodynamic parameters. The shortened scan time may enable the clinical translation of CS 4D flow, although potential hemodynamic underestimation should be considered when interpreting the results.

Approaches for Reactive Oxygen Species and Oxidative Stress Quantification in Epilepsy.

Oxidative stress (OS) and excessive reactive oxygen species (ROS) production have been implicated in many neurological pathologies, including acute seizures and epilepsy. Seizure-induced damage has been demonstrated both in vitro and in several in vivo seizure and epilepsy models by direct determination of ROS, and by measuring indirect markers of OS. In this manuscript, we review the current reliable methods for quantifying ROS-related and OS-related markers in pre-clinical and clinical epilepsy studies. We first provide pieces of evidence for the involvement of different sources of ROS in epilepsy. We then discuss general methods and assays used for the ROS measurements, mainly superoxide anion, hydrogen peroxide, peroxynitrite, and hydroxyl radical in in vitro and in vivo studies. In addition, we discuss the role of these ROS and markers of oxidative injury in acute seizures and epilepsy pre-clinical studies. The indirect detection of secondary products of ROS such as measurements of DNA damage, lipid peroxidation, and protein oxidation will also be discussed. This review also discusses reliable methods for the assessment of ROS, OS markers, and their by-products in epilepsy clinical studies.

SmAvo and smaTo: A fruity odyssey of smart sensor platforms in Southern Africa

Avocado and tomato production are key agricultural sectors for many economies including South Africa. The quality of avocadoes and tomatoes that reach consumers is directly dependent on the handling at the postharvest stage. The fruit undergoes an extensive journey, and subsequently stress, comprised of several steps, including harvesting, application of postharvest treatments, packaging and transportation by road and sea to reach the export markets. To date, the quantification of these external stresses on a discrete fruit has not been measured in detail, primarily due to a lack of compatible instrumentation. This paper demonstrates a low cost, stand-alone, open source data acquisition system, termed smAvo and smaTo, that can be introduced effortlessly to monitor agricultural processing facilities and transportation networks. The miniaturised Arduino sensor platform is enclosed within a waterproof enclosure and surrounded by a 3D printed shell manufactured from morphologically compatible materials. The software is customisable to the needs of the research project or individual transportation phases under study, providing both extensive environmental data and high-frequency tri-axis acceleration measurements that are crucial to understanding the dynamic processes that directly affect the final quality of the fruit. Four successful field trials demonstrate the fidelity of both the smAvo and smaTo platforms.

Prediction of failures in steam boiler using quantification of residual stresses

The paper presents an analysis of the causes of an accident that occurred in the steam boiler during operation as aresult of the failure of the control system and subsequent uncontrolled operation of the steam boiler for several hours. After shutdown of the boiler, cracks were identified in many places of the piping system of the boiler and in one place the pipeline was completely destroyed. Analysis of the chemical composition and mechanical properties of the material and quantification of residual stresses by the hole drilling method were performed to assess possible causes of the failure of the steam boiler piping system. The effect of sudden temperature change on the failure of a piping system was performed by the finite element method. Based on the obtained results, it can be concluded that the temperature change in the piping system cannot be considered the main cause of the pipe system failure and that the accident did not occur only due to the failure of several protective mechanisms of the system. High levels of residual stress quantified at the site of the breach were found to be the most important cause of the failure.