Stress In Different Parts Research Articles

Thermo-mechanical evaluation of UO2-SiC fuel rod in hypothetical accidents using COMSOL multiphysics

In this research, the COMSOL is used as a multi-physics software to simulate the thermo-mechanical performance of a UO2-SiC fuel rod in hypothetical accidents of WWERs. First, by using the thermal and mechanical analysis, the temperature, strain and stress in different parts of the UO2-SiC fuel rod in normal operation are calculated. Next the performance of fuel rod in hypothetical reactivity insertions and hypothetical semi loss of coolant is evaluated. The results of the thermal and mechanical analysis of UO2-SiC fuel with different percentages of SiC and the substitution of Si instead of zirconium clad are also analyzed. Coupling point kinetic equations with COMSOL events related to the increase in reactor power, such as the reactivity insertion accident (RIA), are simulated. For more detail study, hydrogen diffusion in the clad, oxygen diffusion in the fuel and non-stoichiometric fuels are considered. Finally, a sensitivity analysis is carried out to see how the effective quantities affect the mechanical and thermal evaluations and COMSOL is introduced as a multi physics software could present accident evaluations.

Reflectance spectra for identifying stress in different parts of leaf: a case study on oil palm seedlings

ABSTRACT In this study, the spectral responses to drought stress of different parts in the leaf of oil palm seedlings named base, middle, and tip were investigated. The ability to detect stress even before symptoms emerge requires knowledge of which part of oil palm leaves responds more quickly to the stress. The analysis of the reflectance spectra in region 650–1050 nm was conducted on respective sections of the leaves of the oil palm seedlings. The analysis revealed that the stress affects the tip of the leaf, followed by the middle and then the base. It was noticed that the greatest loss of water and chlorophyll content was at the tip of the leaf. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used for clustering, while support vector machine (SVM) and linear discriminant analysis (LDA) were applied for categorization purposes. The outcomes of the PCA and HCA showed that the separation between the samples was based on the day and stress levels at respective sections of the leaf. With this, the possession of distinct morphological and physiological features by each part of the leaf can be concluded. From the PCA loadings, it was found that the regions 699–756 nm, 833–877 nm, and 933–958 nm showed noticeable bands and can be used to distinguish between the oil palm seedlings under stress. In addition, LDA and SVM classifiers demonstrated that the prediction accuracy of the stress level in oil palm seedlings was not influenced by the location in the leaf where the spectra were acquired.

Spectral indices for characterizing lentil accessions in the dryland of Pacific Northwest

Lentil is a cool season legume crop suffering terminal stress in different parts of the world, especially in North America, Australia, Southwest Asia and North Africa. Drought stress, which is often linked with high temperatures, is very damaging to grain legumes in practically all agricultural environments. In this experiment, 49 accessions were sown with a check variety in an augmented design in Whitlow farm 2015, central ferry farm 2016 and Spillman farm 2016, Washington state university. The three different locations were in the dryland of southeastern Washington. The collected 49 accessions were screened, where 32 accession were taken from the United States Department of Agriculture's single plant-derived core collection and 16 from lentil reference population of ICARDA and one check variety was Avondale. Secondary traits such as green Normalized difference vegetation index (GNDVI), red Normalized difference vegetation index (RNDVI), photochemical reflectance index (PRI), red Normalized difference vegetation index (RNDVI), water band index (WBI), and normalized water index (NWI) were collected using a multi spectral reflectance device and agronomic metrics such as days to flowering (DF), biomass yield per plant (BYP) and seed yield per plant (SYP) data were also collected as well. Multi trait genotype ideotype distance (MGIDI) addresses the restrictions of AMMI and GGE analysis by using BLUP and ideotype distance, which can properly select genotypes considering higher yields as well as consider other desirable parameters GNDVI, RNDVI, PRI, WBI, NWI. The accessions Avondale, PI 368647, ILL7090, PI33690, PI 5187, ILL 86, ILL595, PI 533690, PI 518734, ILL 1649, ILL 4781 were selected as the ten best genotypes and Avondale, ILL7090, PI533690 were less affected by G x E interaction and selected for further evaluation based on AMMI, GGE and MGIDI index.

RESULTS OF THE TECTONOPHYSICAL STUDY IN THE DZHANKHOT THRUST ZONE (NORTHWESTERN CAUCASUS)

The paper presents the results of detailed structural analysis of the Dzhankhot thrust zone which is a part of the system of overthrust nappe structures in the southern slope of the Northwestern Caucasus. The relevance of the research topic is found on the reason that despite the obvious importance of these overthrust nappes in the structure of the Greater Caucasus there is still lack of in-situ observational data on the detailed structure of thrust zones and on tectonic stress distribution pattern therein.As a result of the structural and geological studies of small disjunctive and plicative forms in the Upper Cretaceous and Paleocene sediment contact along the Dzhankhot thrust, there were identified the major structural and tectonic deformation patterns and the areal distribution of tectonic deformations depending on the distance to the thrust. There was determined the major type of stress in different parts of the thrust zone. There was shown the difference in the development of geological indicators of faults for different elements of the folded structures. In some cases, there was determined the sequence of deformations, from synsedimentary structures (clastic dikes in particular) to post-sedimentary brittle structures.The orientation of principal stress axes determined from the reconstruction data by method of cataclastic analysis of faults confirms a thrust-type deformation within the studied area near the Dzhankhot thrust. Local stress-tensor determinations are in good agreement with the location of observation points in the regional tectonic structure. Trajectories of the maximum compression axes, most of which are submeridionally and NNW-trending, change orientation to the northwest in the immediate vicinity of the Dzhankhot thrust fault zone. The identified features of tectonic structure and stressed-strained state of the Dzhankhot thrust zone allow considering this area as a natural structural and tectonophysical testing ground for both tectonic-stress-reconstruction-improvement methodologies and a study on natural deformation structures of the Greater Caucasus.

Implications of Foliar Particulate Matter Deposition on the Physiology and Nutrient Allocation of Dominant Perennial Species of the Indo-Gangetic Plains.

The ramifications of different concentrations of foliar particulate matter on the physiology, nutrient stoichiometry, allocation pattern, and their corresponding re-translocation rates were investigated for evergreen (Mangifera indica and Psidium guajava), semi-evergreen (Ficus religiosa and Azadirachta indica), and deciduous (Dalbergia sissoo) tree species in a simulation experiment over an exposure period of 2 years. Physiological parameters (Pn, gs, Ci, E, and WUE), nutrient stoichiometry (C: N) in different plant parts, and their allocation pattern for five macro- (C, N, K, Mg, Ca) and five (Zn, Ni, Mn, Cu, Fe) micro-elements at two different concentrations of particulate matter (ambient and elevated) with respect to control (no particulate load) were assessed. Significant differences in nutrient concentrations and their re-translocation rates were observed between the treatments in evergreen species compared to deciduous species. The photosynthetic rate significantly declined with an increase in foliar deposition of particulate matter. Higher variations in C, N, K, Mg, and Zn levels were found compared to other elements under particulate matter stress and the ratio of C/N showed a slight decline in mature leaves except in deciduous tree species. The nutrient stoichiometry revealed that the deciduous species were more tolerant whereas the re-translocation efficiency was maximum for the semi-evergreen tree species. The nutrient allocation was found greater in foliage compared to branch in evergreen and was opposite in semi-evergreen and deciduous tree species. The element re-translocation rate indicated an inconsistent behavior in nutrient recycling under the particulate matter load depending upon the tree species. The study entrenched a critical change in nutrient re-translocation and allocation pattern under the particulate stress in different parts of the tree, suggesting a novel approach for screening the tree species for sustainable plantation and planning of urban areas.

The noise pollution and heat stress in different parts of Rabak Cement Factory, White Nile State, Sudan

Cement industry caused environmental impacts at all stages of the process in the area; include emissions of airborne pollution in the form of dust, gases, noise and vibration. This study is conducted to evaluate the noise pollution and heat stress in different parts of Rabak Cement Factory. The study involved the exposed and unexposed groups. The noise levels were measured by the aid of an occupational health specialist who was familiar with the measuring device instructions and the study protocol. On the other hand, structured questionnaires were used to assess the workers' response to noise pollution in all sections of the factory. Environmental temperature was measured as close as feasible to the work area where the workers are exposed. The measurements were taken from two locations in the factory; the chemical laboratory and kiln in order to determine the heat stress. Some instruments were used to calculating heat stress parameters. Highest noise level was found in compressors 105.33 dB, conveyor belts 101.66 dB, raw materials mills 98.33dB and workshops 97.00 dB. The levels exceeded the maximum permitted noise level described by WHO. There is high temperature in work environment over standard level which may lead to heat stress. For these findings, the company should create a formal noise and heat stress management program.

Sleep Deprivation Affects Brain Acetylcholinesterase Activity and Cognitive Ability in Young and Aged Rats

Sleep plays an important role in maintaining neuronal circuitry, signalling and helps maintain overall health and wellbeing. Sleep deprivation (SD) disturbs the circadian physiology and exerts a negative impact on brain and behavioural functions. SD impairs the cellular clearance of misfolded neurotoxin various proteins which are involved in major neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease. SD affects the immunological and redox system resulting in neuroinflammation and oxidative stress. The aim of the present study is to investigate sleep deprivation (SD) induced oxidative stress in different parts of the brain and in vivo behavioural changes associated with aging. Lipid peroxidation and reduced antioxidant status were significantly (p<0.05) increased along with the altered learning and memory ability. The most affected part of the brain was hippocampus followed by cerebral cortex. Acetyl cholinesterase was found to be altered in SD treated rats. These are remarkably correlated with the cognitive impairment. Aging is the affects more deleterious effect. It is also evident that SD induces premature aging in the study.

Treenuts and groundnuts in the EAT-Lancet reference diet: Concerns regarding sustainable water use

The EAT-Lancet universal healthy reference diet recommends an increase in the consumption of healthy foods, among which treenuts and groundnuts. Both are, however, water-intensive products, with a large water footprint (WF) per unit of mass and protein and already today contribute to blue water stress in different parts of the world. The envisaged massive required increase in nut production to feed a global population with this reference diet, needs to occur in a water-sustainable way. In this paper, we identify and quantify where current nut production contributes to local blue water stress and discuss options for water-sustainable nut production. We show that 74% of irrigated nuts are produced under blue water stress (of which 63% under severe water stress), throughout many regions of the world, most notably in India, China, Pakistan, the Middle East, the Mediterranean region and the USA. We critically evaluate which nut types to promote given substantial differences in WFs. We propose sustainable intensification of nut production employing nut-specific WF benchmarks. We also recommend integrated water resources management including maximum sustainable levels of water consumption by setting of WF caps.

Optimizing Connecting Rod Design Using Fillet Radius Modifications in ANSYS

In this paper we have investigated a connecting rod design of a 2wheeler,. We have first measured the design parameters of the existing connecting rod and established the material used and cause of failure. We found that surface roughness in the big end is the main area for failure. Then a solid model of the same connecting rod was made using solidworks software. ANSYS software was employed to analyze and examine the effect of stress in different parts of the connecting rod. For the analysis we have started with the existing design parameters and then incrementally changed the fillet radius at big end with keeping the small end dimensions constant and then changing the fillet radius of the small end with keeping the fillet radius of the big end intact. Finally optimum parameters were selected for the modified design for the minimum stress conditions.

On the changes in the sea surface temperature in the benguela upwelling region. Part 2: the long-term tendencies

The paper examines the issue on the long-term trends in the sea surface temperature (SST) in the Benguela upwelling zone and their causes using the daily SST satellite data for 1985–2017’s and the daily near-surface wind for 1988–2017”s. It is shown that in the Benguela upwelling region, there is a significant intensification of driving winds in the last 20 yrs. This is accompanied by a decrease of the thermal upwelling index (taking into account the sign of the index or an increase of its absolute values) in the southern part of the Benguela upwelling, but practically does not influence this indicator in its northern part. The likely reason for this difference is the change in the wind field structure, as a result of which there are opposite trends in the magnitude of the vorticity of the tangential wind stress in different parts of the Benguela upwelling. In the southern part of the Benguela upwelling, both the Ekman’s upwelling and the vertical velocities due to the vorticity of the driving wind intensify, while in the northern part the corresponding trends have the opposite signs. This leads to a partial compensation of these two effects in the northern part of the Benguela upwelling. The reason for the change in the wind field structure is the displacement of the center of the Subtropical High to the south-east and the concomitant reversal of the near-surface wind vector in the coastal zone.

Approaches in Enhancing Thermotolerance in Plants: An Updated Review

Global warming has been increasing manifold in recent times, and this may cause tremendous economic losses in the near future. Recently, heat stress is considered one of the major constraints affecting crop growth and yield at world level. Heat stress reduced the plant growth, photosynthesis, mineral nutrients, and yield attributes. Heat stress caused both ultrastructural alterations and oxidative stress in different parts of plants. Plants can tolerate certain levels of heat stress by maintaining membrane stability, adjusting antioxidants and compatible solutes, and scavenging reactive oxygen species. Heat tolerance in plants can be improved by selecting heat-tolerant cultivars, genetic engineering, and exogenous application of osmolytes, microbes, mineral nutrients, soil amendments, and proper agricultural practices. This review is devoted to discuss the plants’ physiological and biochemical responses to heat stress and various integrated approaches to improve heat stress tolerance in plants.

Screening indices for cadmium-contaminated soil using earthworm as bioindicator.

Artificial soil simulation tests were conducted to study the response of oxidative stress in different parts of Eisenia fetida under cadmium Cd) stress. Factor analysis and analytic hierarchy process were used to establish a comprehensive mathematical model to screen key monitoring indices of the Cd-contaminated soil early warning system. This paper sets the short-term group and the long-term group. The former lasted 10days, and the latter was 30days. Gradient solution of 0, 50, 100, 125, 250, and 500mgkg-1 Cd2+ was used in each test group. The earthworm was cut into two parts from its clitellum to determine oxidative stress indices. Results showed that during the short-term stress, TP (total protein) in the head tissues of the earthworm was the key monitoring index for 3-4 and 8-9days of Cd stress. In addition, the TP in tail tissues was the key index for 2, 4, 6, and 8-10days of stress. On the first and second days, the key monitoring indices in the tail tissues were both the CAT (catalase), while in the head, they were CAT and TP, respectively. On the 5th, the 7th, and the 9th days, the focus should be on monitoring POD (peroxidase) in the tail tissues, while in the head tissues, they were POD, CAT, and TP, respectively. In the long-term test after 10days of Cd stress, the key monitoring index in head tissues was GPX (glutathione peroxidase), and in the tail, it was TP. At 20-30days, the key monitoring indices were TP in the head and MDA (malondialdehyde) in the tail.

Investigation of Performance and Residual Stress Generation of AlSi10Mg Processed by Selective Laser Melting

During the selective laser melting (SLM) process, the scanned layers are subjected to rapid thermal cycles. By working on the mechanical properties, residual stress, and microstructure, the high‐temperature gradients can have significant effect on the proper functioning and the structural integrity of built parts. This work presents a comprehensive study on the scanning path type and preheating temperature for AlSi10Mg alloy during SLM. According to the results, SLM AlSi10Mg parts fabricated in chessboard scanning strategy have higher mechanical properties or at least comparable to the parts fabricated in uniformity scanning strategy. In the SLM processing, the residual stress in different parts of the specimen varies with temperature gradient, and the residual stress at the edge of the specimen is obviously larger than that at the center. Under the chessboard scanning and preheating temperature 160°C, the residual stress in each direction of the specimens reaches the minimum. Under different forming processes, the morphology of the microstructure is obviously different. With the increase of preheating temperature, the molten pool in the side surface is obviously elongated and highly unevenly distributed. From the coupling relationship between the residual stress and microstructure, it can be found that the microstructure of top surface is affected by residual stresses σx and σy. But the side surface is mainly governed by residual stress σy; moreover, the greater the residual stress, the more obvious the grain tilt. In the XY and XZ surfaces, the scanning strategy has little influence on the tilt angle of the grain. But, the tilt angle and morphology of the microstructure are obviously affected by the preheating temperature. The results show that the residual stresses can effectively change the properties of the materials under the combined influence of scanning strategy and preheating temperature.

The present-day stress field of Australia: New release of the Australian Stress Map

SUMMARY The present-day stress field is important for a range of earth science disciplines including petroleum and geothermal geomechanics, mine safety, neotectonics and seismic hazard assessment. So far, many studies have been carried out to understand the state of stress in different parts of the world and the results reveal that the contemporary tectonic stress field can range from being uniform over large areas (100s-1000s of kilometres) to being highly varied over short distances (10s-100s of meters) due to interaction of different parameters. One of the most well-known examples of a heterogeneous stress pattern is observed in the Australian continent, which displays a wide range of stress orientations from province to province that, unlike all other major plates, are not aligned with absolute plate motion. The Australian Stress Map (ASM) project was started in 1996 to compile a public data set of maximum horizontal present-day tectonic stress information to determine and understand the state of stress in the Australian crust. The early phases of the ASM revealed that plate boundary forces provide the first-order control on the present-day stress pattern. However, all models of the stress field have failed to replicate the stress pattern in Eastern, and particularly north-eastern, Australia. The ASM project commenced again in 2012 with a primary aim of building up the database in Eastern Australia, such as new hydrocarbon provinces, and to help better establish the controls on the Australian stress field at scales ranging from tectonic plate down to individual fields and wells. To date, we have interpreted more than 400 borehole image logs in coal seam gas, mineral and conventional petroleum wells. The results show that local sources of stress (i.e. second and third orders) play a key role in the stress pattern of Australia which is an important issue for geothermal and unconventional exploration and production.

Study on Crane Structural Health Monitoring and Early Warning Expert System

Based on current research basis at home and abroad, in order to improve the level of safety technology and safeguard work efficiency, Internet of Things is brought into crane structural health monitoring. Crane structural health risk level evaluation criteria and structural health warning technology expert system are the two key aspects of the project. The mechanical properties of Q235 were studied and theoretical calculations were done by the technologies of ANSYS and ADAMS, finally the threshold was determined. Signals are collected by FBG sensors and transmitted to a demodulator, and then use software calculates the real-time stress by a formula we given in. Finally the real-time stress in different parts of the crane is acquired. If the real-time stress exceeds the allowable stress we set, it issues an alarm signal to the operators.

Structural Health Monitoring of Gantry Crane Based on EDGE Technology

The closely combination of Internet of Things and on-site monitoring and control technology is the development tendency of the site monitoring and control technology, especially the special equipment safety monitoring technology. EDGE technology is one way of Internet of Things technology realization. EDGE technology is a digital mobile phone technology which allows improved data transmission rates as a backward-compatible extension of GSM. It is also considered as a pre-3G (2.75G) radio technology and is part of ITU's 3G definition. It is used as one of the aims of the project which allows the operators to keep abreast of the crane operation status. Then a software platform is developed to monitor the real-time stress. A software platform is developed via a lot of preliminary work as mentioned above. The information is collected by FBG sensors and transmitted to the demodulator, and then the software calculates strain by a formula given in. Finally we acquire the real-time stress in different parts of the crane. If the real-time stress exceeds the allowable stress, it issues an alarm signal to the operator.

Application of Microclimate Modelling and Onsite Survey in Planning Practice Related to an Urban Micro-Environment

Numerical simulations of human thermal comfort conditions were carried out by means of the urban microclimate model ENVI-met in a popular children’s playground located in Szeged, Hungary. Bioclimatic conditions were quantified by the Physiologically Equivalent Temperature (PET). Based on the PET values, thermal stress maps were created in two different periods of typical summer and autumn days. The study aims to reveal the seasonal and diurnal spatial patterns of the simulated thermal conditions and thus the degree of heat stress in different parts of the playground. Furthermore, we analysed the momentary spatial distributions of the visitors triggered by the microclimatic conditions of the area. According to the simulation, remarkable differences in the thermal conditions were found depending on the sun elevation and the resulting shaded conditions as well as the radiation of the heated surfaces. The spatial distribution of the visitors seems to be highly influenced by the patterns of the thermal conditions but the location and the preference of the children’s playground equipment also affects it. In order to reveal the possible causes of the people’s behaviour, an onsite questionnaire survey was conducted on their opinions and possible modification requirements related to the design of the playground.

A Semi-mechanistic Modeling Strategy to Link In Vitro and In Vivo Drug Release for Modified Release Formulations

To develop a semi-mechanistic model linking in vitro to in vivo drug release. A nonlinear mixed-effects model describing the in vitro drug release for 6 hydrophilic matrix based modified release formulations across different experimental conditions (pH, rotation speed and ionic strength) was developed. It was applied to in vivo observations of drug release and tablet gastro intestinal (GI) position assessed with magnetic marker monitoring (MMM). By combining the MMM observations with literature information on pH and ionic strength along the GI tract, the mechanical stress in different parts of the GI tract could be estimated in units equivalent to rotation speed in the in vitro USP 2 apparatus. The mechanical stress in the upper and lower stomach was estimated to 94 and 134rpm, respectively. For the small intestine and colon the estimates of mechanical stress was 93 and 38rpm. Predictions of in vivo drug release including between subject/tablet variability was made for other newly developed formulations based on the drug release model and a model describing tablet GI transit. The paper outlines a modeling approach for predicting in vivo behavior from standard in vitro experiments and support formulation development and quality control.

Comparative studies on chlorpyrifos and methyl parathion induced oxidative stress in different parts of rat brain: Attenuation by antioxidant vitamins

Organophosphate (OP) pesticides are among the most widely used synthetic chemicals for controlling a wide variety of pests. Chlorpyrifos ( o, o′-diethyl- o-3,5,6-trichloro-2-pyridyl phosphorothionate, CPF) is among the leading OP pesticides used extensively throughout the world including India while methyl parathion ( o, o-di methyl- o- p-nitrophenyl phosphorothioate, MPT) another OP compound, widely used as insecticide and acaricide to control many biting or sucking pests of agricultural crops. Present study was carried out to compare the chronic toxicity of CPF and MPT, their potential to generate oxidative stress and ameliorating effects of antioxidant vitamins in brain of rats. Results of the present study clearly demonstrated that the oral exposure of CPF or MPT, generated oxidative stress in different parts of rat brain consequently accumulating malondialdehyde (MDA) and 4-hydroxynonanal (4HNE), the two major end products of lipid peroxidation, in all the three brain regions i.e. fore-, mid- and hind-brain. The levels of hydrogen peroxide (H 2O 2) were also increased in all the three brain regions when compared with control. CPF and MPT exposure caused decrease in the levels of reduced glutathione (GSH) and increase in the levels of oxidized glutathione (GSSG) in all the three brain regions. The increase in the levels of MDA, 4HNE, H 2O 2 and GSSG was less pronounced when CPF or MPT was given to the rats fed with a mixture of vitamin A, E and C. The present findings clearly show that oral intake of a mixture of vitamin A, E and C protects the rats from MPT or CPF induced oxidative stress and suggest that this treatment alleviates the toxicity of these pesticides to a greater extent.

Extracellular matrix composition of different regions of the knee joint cartilage in cattle

Articular cartilage covering the bone ends at the joint shows different chemical composition in different regions, depending on the mechanical and biological properties of that region. Several studies have shown a relationship between the chemical composition of the cartilage and biomechanical forces. In the present study we analysed five different knee joints divided into the following regions: F1-medial and lateral border of the patellar surface, F2-patellar surface of the femur, F3-medial and lateral condyles, P-articular surface of the patella and T-medial and lateral condyle of the tibia. The main glycosaminoglycan (GAG) present in these regions was chondroitin sulfate. Analysis of total GAG after digestion of the tissue with papain showed that in F2 and F3 there was a larger quantity of GAG/mg tissue, probably due to the dynamic character of the biomechanical forces in these regions. No significant differences were found for the extract and D1 fractions of the different regions. Analysis of the D4 fraction showed that the protein content was higher in the F3 and P regions than in their opposite T and F2 regions. The differences among the five regions may be a result of the non-uniform presence of biomechanical forces supported by these regions. It is important to consider that the intensity and direction of stress in different parts of a tissue may influence the composition of the extracellular matrix.