Stress Compensation Research Articles

Experimental Determination of Critical Fields of 90-Degree Domain Wall Displacement in Plastically Deformed Low-Carbon Steels

Experimental data are presented for the field dependences of differential magnetic permeability μd (H0) of plastically deformed low-carbon steel-St3 samples both in an unloaded state and under tensile stresses. It is shown that applying tensile stresses drastically changes the shape of curves μd (H0 ) a fact that indicates compensation of internal residual compressive stresses in the samples by external tensile stresses. A new technique is proposed for the experimental determination of the critical fields of displacement of 90-degree domain boundaries based on dependences μd (H0 ). Residual compressive stresses in plastically deformed St3 steel are estimated.

Accurate calculation and measurement method for elongation of pre-stressed strand of Bridges

In the pre-stressed construction of bridge strands, tension stress is used as the control and strand elongation is used as the calibration and the elongation of strands directly affects the performance of the bridge structure. So, it must be very precise. In actual construction, due to inadequate grasp of basic theory by technicians, improper measurement methods or inaccurate selection of calculation formulas, neglecting the relationship between the actual elongation value and the tool/job clip withdrawal amount, resulting in the deviation between the actual measured value and the theoretical design value is beyond the standard, which is very unfavorable to the quality of the engineering structure. This article starts with the basic science theory, through numerical calculation and theoretical analysis, explains the work stress compensation retracting amount of the Work anchor and tool anchor, and the compensation stress calculation method due to the stress loss caused by the retraction. It shows the working principle of the pre-stressed equipment, and proposes and validates accurate calculation and measurement method of strand extension.

Shakedown analysis of elastic-plastic structures considering the effect of temperature on yield strength: Theory, method and applications

According to the extended Melan's static theorem, theoretical and numerical aspects of the stress compensation method (SCM) are presented to perform shakedown analysis of elastic-plastic structures considering the effect of temperature on yield strength. Instead of constructing a mathematical programming formulation, this developed method consists of the two-level iterative scheme. The inner loop constructs the statically admissible self-equilibrating stress field, while the outer loop evaluates a sequence of decreasing load factors to approach to the shakedown limit multiplier. The yield strength considering temperature effect is updated based on the current temperature at each outer iteration, and the yield conditions are checked at all Gauss points. The numerical procedure is well incorporated into ABAQUS finite element code and used for calculating the shakedown limits of structures considering yield strengths as different functions of temperature under complex thermomechanical loading system. The method is validated by some plane stress and axisymmetric numerical examples with theoretical and numerical solutions, and subsequently applied to solve the practical shakedown problem of a pipe with oblique nozzle. The results demonstrate that the developed method is stable, accurate and efficient, and can effectively evaluate the shakedown limit of an elastic-plastic structure where the yield strength of material varies with temperature.

Apparatus for combined nanoscale gravimetric, stress, and thermal measurements

We present an apparatus that allows for the simultaneous measurement of mass change, heat evolution, and stress of thin film samples deposited on quartz crystal microbalances (QCMs). We show device operation at 24.85 ± 0.05 °C under 9.31 ± 0.02 bars of H2 as a reactive gas. Using a 335 nm palladium film, we demonstrate that our apparatus quantifies curvature changes of 0.001 m-1. Using the QCM curvature to account for stress induced frequency changes, we demonstrate the measurement of mass changes of 13 ng/cm2 in material systems exhibiting large stress fluctuations. We use a one-state nonlinear lumped element model to describe our system with thermal potentials measured at discrete positions by three resistance temperature devices lithographically printed on the QCM. By inputting known heat amounts through lithographically defined Cr/Al wires, we demonstrate a 150 μW calorimetric accuracy and 20 μW minimum detectable power. The capabilities of this instrument will allow for a more complete characterization of reactions occurring in nanoscale systems, such as the effects of hydrogenation in various metal films and nanostructures, as well as allow for direct stress compensation in QCM measurements.

The effect of arginine on the activity and compartmentalization of lysosomal cysteine proteinases of parenchymatous organs in oxidative stress on the background of experimental hyperhomocysteinemia

Aim. Evaluation of the effect of arginine on the activity and intracellular distribution of cathepsins B, L, H in liver, kidney and lung tissue in experimental hyperhomocysteinemia and developing on its background oxidative damage of proteins.
 Materials and Methods. Hyperhomocysteinemia in male rats of the Wistar line was formed by daily oral administration of a suspension of methionine at a dose of 1.5 g/kg 2 times a day for 21 days, to study the action of arginine the substance was used orally from 12 to 21 days of methionine administration at a dose of 500 mg/kg. In tissue homogenates measurements were carried out in cytoplasmic and lysosomal fractions. The state of oxidative modification of proteins was evaluated by analysis of the absorption spectrum of carbonyl derivatives, the activity of cathepsins B, L, H was determined by spectrofluorometric method, the activity of acid phosphatase – by the unified method «at the end point».
 Results. In the cytoplasmic (nonsedimentary) fraction of the liver and kidney reduced activity of cathepsin L (in both tissues), cathepsin B (in the kidney), cathepsin H (in the liver) was found on the background of the increase in the products of proteins oxidative modification in experimental hyperhomocysteinemia. The introduction of arginine in experimental hyperhomocysteinemia completely eliminated the manifestations of oxidative damage of proteins, partially correcting the activity of enzymes: there was an increase in the activity in non sedimentary (cytoplasmic) fraction due to intracellular redistribution of enzymes. There is found inverse correlation between the content of oxidative carbonylation products of proteins and the activity of cathepsins in the non sedimentary fraction, as well as the proportion of their non sedimentary activity.
 Conclusions. 1. Arginine at a dose of 500 mg/kg at a 10day administration completely corrects the increase in the products of oxidative protein carbonylation that develops in experimental hyperhomocysteinemia. 2. Under the influence of arginine there is an increase in the reduced due to isolated hyperhomocysteinemia activity of cathepsins B, L, H in the cytoplasmic fraction of the liver and kidney due to intracellular redistribution of enzymes. 3. Arginine administration causes nonselective increase of the lysosomal membrane permeability, and as a result, changes in the compartmentalization of lysosomal cysteine proteases. 4. The inverse correlation of the level of protein oxidative modification products with the activity of cathepsins in cytoplasmic (nonsedimentary) fractions, and the proportions of their nonsedimentary activity, suggesting the presence of contribution of changes in the compartmentalization of lysosomal cysteine proteinases in developing under the action of arginine compensation of oxidative stress in experimental hyperhomocysteinemia.

The effect of arginine on the activity and compartmentalization of lysosomal cysteine proteinases of parenchymatous organs in oxidative stress on the background of experimental hyperhomocysteinemia

Aim. Evaluation of the effect of arginine on the activity and intracellular distribution of cathepsins B, L, H in liver, kidney and lung tissue in experimental hyperhomocysteinemia and developing on its background oxidative damage of proteins.
 Materials and Methods. Hyperhomocysteinemia in male rats of the Wistar line was formed by daily oral administration of a suspension of methionine at a dose of 1.5 g/kg 2 times a day for 21 days, to study the action of arginine the substance was used orally from 12 to 21 days of methionine administration at a dose of 500 mg/kg. In tissue homogenates measurements were carried out in cytoplasmic and lysosomal fractions. The state of oxidative modification of proteins was evaluated by analysis of the absorption spectrum of carbonyl derivatives, the activity of cathepsins B, L, H was determined by spectrofluorometric method, the activity of acid phosphatase – by the unified method «at the end point».
 Results. In the cytoplasmic (nonsedimentary) fraction of the liver and kidney reduced activity of cathepsin L (in both tissues), cathepsin B (in the kidney), cathepsin H (in the liver) was found on the background of the increase in the products of proteins oxidative modification in experimental hyperhomocysteinemia. The introduction of arginine in experimental hyperhomocysteinemia completely eliminated the manifestations of oxidative damage of proteins, partially correcting the activity of enzymes: there was an increase in the activity in non sedimentary (cytoplasmic) fraction due to intracellular redistribution of enzymes. There is found inverse correlation between the content of oxidative carbonylation products of proteins and the activity of cathepsins in the non sedimentary fraction, as well as the proportion of their non sedimentary activity.
 Conclusions. 1. Arginine at a dose of 500 mg/kg at a 10day administration completely corrects the increase in the products of oxidative protein carbonylation that develops in experimental hyperhomocysteinemia. 2. Under the influence of arginine there is an increase in the reduced due to isolated hyperhomocysteinemia activity of cathepsins B, L, H in the cytoplasmic fraction of the liver and kidney due to intracellular redistribution of enzymes. 3. Arginine administration causes nonselective increase of the lysosomal membrane permeability, and as a result, changes in the compartmentalization of lysosomal cysteine proteases. 4. The inverse correlation of the level of protein oxidative modification products with the activity of cathepsins in cytoplasmic (nonsedimentary) fractions, and the proportions of their nonsedimentary activity, suggesting the presence of contribution of changes in the compartmentalization of lysosomal cysteine proteinases in developing under the action of arginine compensation of oxidative stress in experimental hyperhomocysteinemia.

Behavioral Assessment of Stress Compensation in Minipigs Transgenic forthe Huntington Gene Using Cortisol Levels:A Proof-of-Concept Study.

Huntington's disease (HD) is an autosomal-dominant, progressive neurodegenerative disorder with motor, cognitive, behavioral and metabolic symptoms. HD patients exhibit an altered response to stress which is reflected in changes of cortisol levels. Large animal models of HD such as the Libechov minipig are currently explored in preclinical studies to improve translational reliability and assessing behavior is of interest. This study aimed to investigate whether cortisol metabolism and response to stress are changed in minipigs transgenic for the Huntington gene (tgHD) compared to wildtype (wt) animals suggesting that cortisol may be used as a marker for stress in minipigs. Thirty-two Libechov minipigs (14 tgHD and 18 wt) were tested before, during and after a stressor, i.e., a hoof trimming procedure, was applied at baseline and after one year. A total of six saliva samples were collected at each assessment and cortisol was measured. In addition, body temperature and respiratory rate were assessed at three pre-determined points during each hoof trimming procedure. All minipigs showed a rise of cortisol in response to the hoof trimming stressor similarly to cortisol changes induced by stress observed in humans. No relevant differences were detected between tgHD and wt minipigs. Cortisol testing for the assessment of stress compensation, e.g., during hoof trimming, is feasible and well tolerated in wt and tgHD minipigs. To elucidate the time profile of cortisol responses to stressors further studies with assessments at multiple time points and exploration of the diurnal profiles of cortisol in minipigs are recommended.

Nutrient‐specific compensation for seasonal cold stress in a free‐ranging temperate colobine monkey

Abstract Homeostatic responses of animals to environmentally induced changes in nutrient requirements provide a powerful basis for predictive ecological models, and yet, such responses are virtually unstudied in the wild. We tested for macronutrient‐specific compensatory feeding responses by free‐ranging golden snub‐nosed monkeys (Rhinopithecus roxellana) inhabiting high altitude temperate forests, where they experience a substantial difference in ambient temperature in cold winters vs. warmer springs. The monkeys had free access to natural foods throughout the year, and to ensure that any seasonal differences in nutrient intake were due to homeostatic compensation and not constraints on food availability, we studied the monkeys during periods in which they were provisioned with the same amount of supplementary foods in winter and spring. Thermoregulatory energy costs in winter and spring were calculated using partitional calorimetric estimations of convective and radiative heat loss obtained from thermal imaging of free‐ranging monkeys in situ. Daily nutrient intakes were measured using continuous focal follows (average 6.9 hr/day) of free‐ranging individuals (27 days in spring and 28 days in winter). We used a nutritional geometry framework to integrate these data and test three predictions: (a) In order to remain thermoneutral (balance heat loss with heat expenditure), golden snub‐nosed monkeys increase daily energy consumption during the winter compared to spring; (b) this increase is achieved specifically by increasing intake of the primary energetic nutrients, carbohydrate and lipid, relative to protein; and (c) the seasonal increase in ingested fat and carbohydrate calories will quantitatively match the additional thermoregulatory costs in winter compared with spring. Our results showed that daily metabolisable energy intake in winter (721.5 kJ/mbm) was 1.8 times that in spring (399 kJ/mbm). As predicted, this difference was specific to fat and carbohydrate, whereas seasonal protein intake did not differ significantly. Winter consumption of fat and carbohydrate was 326 kJ/mbm per day greater than in spring, a value that closely matched the seasonal difference in the daily energetic costs of thermoregulation (329 kJ/mbm). This is the first study to test for a match between nutrient‐specific homeostatic compensation and environmentally induced perturbations in nutrient requirements in free‐ranging animals and underpins the potential for the homeostasis framework to provide predictive power to ecological models.

A numerical formulation and algorithm for limit and shakedown analysis of large-scale elastoplastic structures

In this paper, a novel direct method called the stress compensation method (SCM) is proposed for limit and shakedown analysis of large-scale elastoplastic structures. Without needing to solve the specific mathematical programming problem, the SCM is a two-level iterative procedure based on a sequence of linear elastic finite element solutions where the global stiffness matrix is decomposed only once. In the inner loop, the static admissible residual stress field for shakedown analysis is constructed. In the outer loop, a series of decreasing load multipliers are updated to approach to the shakedown limit multiplier by using an efficient and robust iteration control technique, where the static shakedown theorem is adopted. Three numerical examples up to about 140,000 finite element nodes confirm the applicability and efficiency of this method for two-dimensional and three-dimensional elastoplastic structures, with detailed discussions on the convergence and the accuracy of the proposed algorithm.

Interfacial Form Stress in the Southern Ocean State Estimate

AbstractThe wind stress that drives the Antarctic Circumpolar Current (ACC) exits the fluid via topographic form stress (TFS) at the sea floor; interfacial form stress (IFS) is thought to carry much of this momentum from source to sink. These form stresses combine to help set the strength and structure of the Southern Ocean meridional overturning circulation (MOC), a key nexus of heat and gas exchange between the deep ocean and the atmosphere. For the first time in a general circulation model, we calculate the time‐varying, three‐dimensional IFS field directly from zonal pressure gradients across vertical perturbations in isopycnal layer interfaces. We confirm previous findings that IFS compensates wind stress at the surface and topographic form stress at the seafloor in the Drake Passage latitudes. We find that zonal and time‐mean IFS is primarily responsible for this surface wind stress compensation, with some contribution from transient eddy IFS. Mean, standing eddy, and transient eddy IFS combine to compensate topographic form stress at depth. Both standing and transient eddy IFS concentrate at stationary meanders along the ACC, and transient eddy IFS dominates standing eddy IFS in regions of high eddy kinetic energy. Finally, total IFS changes sign from balancing eastward wind stress to balancing westward topographic form stress around 28.1 kg m−3, close to the upper limit of Antarctic Bottom Water, indicating the role of buoyancy forcing in setting the structure of the IFS field.

Proteomic Analysis of Cerebral Cortex Extracts from Sus scrofa with Induced Hemorrhagic Stroke.

Cerebrovascular diseases, including stroke and micro stroke, are the main causes of death in contemporary society. Hemorrhagic stroke is the fast emerging defficiency in the brain function resulting from disturbance of blood supply to the brain caused by the rapture of blood vessels (Lopez et al. in Proteomics Clin Appl 6:190-200, 2012). The influence of a model hemorrhagic stroke on white pigs with the change in the protein profile of their cortical samples 24 h and 2 months after the stroke was examined using mass-spectrometric analysis. Different proteins (n = 30) were identified, and their content was elevated. These proteins are involved in the mechanisms of neuroprotection, including compensation of oxidative stress (TXN, SNCA, PRDX6, ENO1), prevention of unwanted protein aggregation and apoptosis (PTMA, SNCA, SNCB), release of neurotransmitters (GAPDH, PEBP1) and assembly of the cytoskeleton (ACTA2, PTMA, TUBA4A, TUBA1D), etc. Also, a group of seven Ras family proteins involved in the regulation of cell proliferation and differentiation was found in the samples taken 24 h following the stroke. The relative concentrations of most of the proteins in the samples taken 2 months after the stroke demonstrate intermediate values between the control sample and the sample taken in 24 h, indicating the extinction of change in the protein profile with time. During the first 24 h after the stroke, there is an increase in protein fractions participating in exocytosis, synaptic plasticity/signaling, and support of neurotransmitter transport. Such shift in the weight of protein functional clusters can be attributed to activation of compensatory mechanisms in the body focused on neuroprotection.

Shakedown analysis of engineering structures under multiple variable mechanical and thermal loads using the stress compensation method

The determination of shakedown load or shakedown domain is an important task in structural design and integrity assessment. In this paper, a novel numerical procedure based on the stress compensation method (SCM) is developed to perform shakedown analysis of engineering structures under multiple variable mechanical and thermal loads. By applying the compensation stress on the yield regions that occur at every load vertex of the prescribed loading domain to adjust the total stress to the yield surface and re-solving the equilibrium equations, the statically admissible residual stress field for static shakedown analysis is constructed. A robust and effective iteration control technique with some convergence parameters is used to check the change of the compensation stress in the inner loop and to update the shakedown load multiplier in the outer loop. For the purpose of general use, the method is implemented into ABAQUS platform. The shakedown problems for the Bree plate, a square plate with a central circular hole and a practical thick vessel with nozzles under some two-dimensional and three-dimensional loading domains are effectively solved and analyzed. Both alternating plasticity mechanism and ratcheting mechanism to determine the shakedown boundary of these structures are revealed. Numerical applications show that the proposed method has good numerical stability, high accuracy and efficiency, and is well suited for shakedown analysis of large-scale practical engineering structures.

Prefinished Metal Polymer Hybrid Parts

In this study, the shaping and assembly behavior of adhesive polymer-metal-composites was investigated in an international cooperation using two step curable uretdione-polyester-based powder coatings (IPF development) which acts simultaneously as a reactive adhesive agent and as a high quality surface finish. To create the composite, a thermoplastic polyurethane (TPU) layer with good compatibility to the powder coating was over-molded onto a powder coated aluminum substrate. A polyamide (PA6) layer was over-molded on to the TPU layer to create a stiff composite structure with possibilities for further functionalization. The TPU-layer in between the metal substrate and the polymer top layer acts as a stress and strain compensation layer. These loads are caused by thermal expansion (under fluctuating temperatures) and external forces/deformation. Another key feature of the composite is the innovative process chain. The powder coating can resist high deformation and therefore the coating is suitable for a future application on to a metal substrate using a coil coating procedure. In addition, the coil could be easily implemented into a production line as a semi-finished product. The prefinished coated metal substrate could be formed (e.g. incremental forming, deep drawing) and inserted in the over-molding procedure. This overall shortened process chain allows not only an effective fabrication of pre-coated semi-finished materials and polymer-metal-joints in high quantities by saving process steps (e.g. cleaning steps, glue application) but also a higher versatility in the following composite production.

Review Article: Stress in thin films and coatings: Current status, challenges, and prospects

The issue of stress in thin films and functional coatings is a persistent problem in materials science and technology that has congregated many efforts, both from experimental and fundamental points of view, to get a better understanding on how to deal with, how to tailor, and how to manage stress in many areas of applications. With the miniaturization of device components, the quest for increasingly complex film architectures and multiphase systems and the continuous demands for enhanced performance, there is a need toward the reliable assessment of stress on a submicron scale from spatially resolved techniques. Also, the stress evolution during film and coating synthesis using physical vapor deposition (PVD), chemical vapor deposition, plasma enhanced chemical vapor deposition (PECVD), and related processes is the result of many interrelated factors and competing stress sources so that the task to provide a unified picture and a comprehensive model from the vast amount of stress data remains very challenging. This article summarizes the recent advances, challenges, and prospects of both fundamental and applied aspects of stress in thin films and engineering coatings and systems, based on recent achievements presented during the 2016 Stress Workshop entitled “Stress Evolution in Thin Films and Coatings: from Fundamental Understanding to Control.” Evaluation methods, implying wafer curvature, x-ray diffraction, or focused ion beam removal techniques, are reviewed. Selected examples of stress evolution in elemental and alloyed systems, graded layers, and multilayer-stacks as well as amorphous films deposited using a variety of PVD and PECVD techniques are highlighted. Based on mechanisms uncovered by in situ and real-time diagnostics, a kinetic model is outlined that is capable of reproducing the dependence of intrinsic (growth) stress on the grain size, growth rate, and deposited energy. The problems and solutions related to stress in the context of optical coatings, inorganic coatings on plastic substrates, and tribological coatings for aerospace applications are critically examined. This review also suggests strategies to mitigate excessive stress levels from novel coating synthesis perspectives to microstructural design approaches, including the ability to empower crack-based fabrication processes, pathways leading to stress relaxation and compensation, as well as management of the film and coating growth conditions with respect to energetic ion bombardment. Future opportunities and challenges for stress engineering and stress modeling are considered and outlined.

InGaN stress compensation layers in InGaN/GaN blue LEDs with step graded electron injectors

We investigate the effect of InGaN stress compensation layer on the properties of light emitting diodes based on InGaN/GaN multiple quantum well (MQW) structures with step-graded electron injectors. Insertion of an InGaN stress compensation layer between n-GaN and the step graded electron injector provides, among others, strain reduction in the MQW region and as a result improves epitaxial quality that can be observed by 15-fold decrease of V-pit density. We observed more uniform distribution of In between quantum wells in MQW region from results of electro- and photoluminescence measurement. These structural improvements lead to increasing of radiant intensity by a factor of 1.7–2.0 and enhancement of LED efficiency by 40%.

Структурно-фазовые превращения в монокристаллическом цирконии при деформации сдвигом под давлением

The structural-phase transformation in pseudo-single crystal of zirconium during deformation on Bridgman anvils is studied by X-ray spectroscopy with synchrotron radiation. The angles of rotation in the Bridgman anvils turning varied from φ = 0 deg to φ = 45 deg. It was shown that the α-phase lattice is compressed at a true strain value e = 4.6, which is reflected in its parameters: the α-phase parameter "α" decreases by 5.3%, and the parameter "c" by 0.3%. On the contrary, the ω-phase arising in the process of deformation under pressure showed a tendency to stretching, if the parameter "a" of this phase practically does not change with an increase in the degree of deformation, then the parameter "c" is insignificant, by 0.14%, but increases. This behavior can probably be explained by the small atomic density and strong anisotropy in terms of the atomic density of the planes and series of the ω-phase. It is determined that the structure arising in the process of deformation of the baric ω-phase, deformation conditions from e = 0.5 to e = 4.6, does not undergo textural changes. At this step of deformation, only the stage of nucleation of the ω-phase is observed only in area of the α-phase, which have a favorable crystallographic orientation. The formation of groups of planar defects in the ω phase is a mechanism for the compensation of elastic stresses during lattice transformation α → ω under conditions of high quasihydrostatic pressure.

Compensation for chronic oxidative stress in ALADIN null mice.

ABSTRACTMutations in the AAAS gene coding for the nuclear pore complex protein ALADIN lead to the autosomal recessive disorder triple A syndrome. Triple A patients present with a characteristic phenotype including alacrima, achalasia and adrenal insufficiency. Patient fibroblasts show increased levels of oxidative stress, and several in vitro studies have demonstrated that the nucleoporin ALADIN is involved in both the cellular oxidative stress response and adrenal steroidogenesis. It is known that ALADIN knock-out mice lack a phenotype resembling human triple A syndrome. The objective of this study was to determine whether the application of chronic oxidative stress by ingestion of paraquat would generate a triple A-like phenotype in ALADIN null mice. Adult male mice were fed either a paraquat (0.25 g/kg diet) or control diet for 11 days. After application of chronic oxidative stress, ALADIN knock-out mice presented with an unexpected compensated glutathione metabolism, but lacked a phenotype resembling human triple A syndrome. We did not observe increased levels of oxidative stress and alterations in adrenal steroidogenesis in mice depleted for ALADIN. This study stresses the species-specific role of the nucleoporin ALADIN, which in mice involves a novel compensatory mechanism for regulating the cellular glutathione redox response.

Symmetrical Sandwich-Structured SiN/Si/SiN Composite for Lithium-Ion Battery Anode with Improved Cyclability and Rate Capacity

Substoichiometric silicon nitride/silicon/substoichiometric silicon nitride (SiN/Si/SiN) composite with a symmetrical sandwich structure is investigated as the anode of thin-film lithium-ion battery. The SiN film between the Si film and electrolyte acts as a clamping layer to suppress the anode volume expansion and stabilize the formation of solid-state interphase, while the SiN film between the Si film and current collector works as a buffer layer to enhance the mechanical strength and electrical contact at the anode/current collector interface. Compared with the pure Si anode, the SiN/Si/SiN anode exhibits improved mechanical stability and keeps intact even after cycling. Consequently, the SiN/Si/SiN anode shows much better cycling stability (1702 mAh g−1 at 0.6 C with a capacity fading rate of 0.1% per cycle) and higher rate performance than the Si anode (3222 mAh g−1 with a fading rate of 0.7% per cycle). Moreover, because the SiN buffer layer can effectively alleviate the stress (caused by anode volume change) accumulated at the anode/current collector interface and also the stress compensation effect can be created by using this symmetrical sandwich structure, the SiN/Si/SiN anode presents higher mechanical stability and thus better electrochemical performance than the anode with a structure of SiN/Si on the current collector.

Metabolic mechanisms of development and compensation of osmotic stress in the brain

Extracellular fluid of the brain, consisting of cerebrospinal fluid and interstitial fluid, is normally isotonic to blood plasma. Problems arise with a rapid change in osmolality of circulating blood or interstitial brain fluid. The permeability of the blood-brain barrier is lower than in the peripheral capillaries, but this permeability is still several times greater than the passive permeability for electrolytes or glucose. Because of this difference, it is believed that the brain is like an osmometer: it swells with reduced plasma osmolality and contracts (dehydrated) when the plasma becomes hypertonic. Osmotic stress has a direct effect on the functioning of the brain and triggers physiological compensatory mechanisms, in the absence of which due to the intensity or duration of stress, irreversible serious complications may develop. Knowledge and understanding of these processes are the basis for preventing their development and treatment.

The influence of stress on the quartz birefringent optical filter

Firstly, based on the elasto-optical effect of quartz crystal, the formula of the transmissivity for the quartz birefringent optical filter (QBOF) applied with the mechanical-stress is derived and analyzed by numerical simulation, which shows that when the stress is applied on the surface of the quartz crystal vertically or parallel to its optical axis, the phase retardation of the quartz crystal will change accordingly, then the output optical spectrum of QBOF applied with stress is measured by Ultra-6600 spectrophotometer, the related experimental results are agreed with the simulation results very well, which show that when the stress is applied on the surface of the quartz crystal, the central wavelength will shift the longer or shorter wavelength according to the direction and the value of the applied stress. At last, a new type of the stress compensation QBOF is proposed, it can offset the change of phase retardation of the quartz crystal caused by the variation of temperature, which will has a certain application for the stable output of optical filter when the environment temperature changes as we believe.