Journal articles on the topic 'Heat flow'

The relation between heat flow, topography and Moho depth for recent maps of Europe is presented. Newest heat flow map of Europe is based on updated database of uncorrected heat flow values to which paleoclimatic correction is applied across the continental Europe (Majorowicz and Wybraniec 2010). Correction is depth dependent due to a diffusive thermal transfer of the surface temperature forcing, of which glacial–interglacial history has the largest impact. This explains some very low uncorrected heat flow values of 20–30 mW/m2in shallow boreholes in the shields, shallow basin areas of the cratons, and in other areas including orogenic belts where heat flow was likely underestimated due to small depth of the temperature logs. New integrated map of the European Moho depth (Grad et al 2009) is the first high resolution digital map for European plate, which is understood as an area from Ural Mountains in the east to mid-Atlantic ridge in the west, and Mediterranean Sea in the south to Spitsbergen and Barents Sea in Arctic, in the north. For correlation we used the following: onshore heat flow density data with palaeoclimatic correction (5318 locations), topography map (30x30 arc seconds, by Danielson and Gesch 2011) and Moho map by Grad et al (2009), providing longitude, latitude and Moho depth (with resolution of 0.1 degree). Analysis was limited to locations for which datasets were available. The area of continental Europe has been divided into two large domains: Precambrian East European craton and Palaeozoic Platform of the West Europe. In addition, two smaller areas were considered, corresponding to Scandinavian Caledonides and Anatolia. The results obtained reveal significantly different correlations between Moho depth, elevation and heat flow for these regions. For each region detailed analysis of these relations in different elevation ranges are presented. In general, it is observed that Moho depth is more significant for heat flow than elevation. Depending on the region and elevation range, heat flow value is up to two times larger than Moho depth, while relation of heat flow to elevation has much more variability.

The flow and heat transfer during impregnation of the filler with a non-Newtonian liquid in the process of forming composite products in closed forms is investigated. The flow is described by the Brinkman equation. In terms of rheology, medium is the Phan-Thien-Tanner fluid. The problem is solved by a numerical method of finite differences.

Introduction. Tanks and tank farms are widespread in many constituent entities of the Russian Federation and are among the most important elements of the model for the production, treatment, transportation and processing of oil and oil products. It is relevant both at the Russian and global levels to ensure that fire safety is arranged for tank farms to reduce highest risk levels according to the risk-based safety model. In the context of information and communication technology (ICT) developments and introduction of ICT into the operation and management of various facilities, over the past decades advanced methods have emerged for predicting the occurrence and development of emergency situations at facilities and enhancing management decisions on containment and elimination of emergency situations including fires.Goals and objectives. In this paper, the authors present a model that they developed to promptly forecast heat flows using artificial neural networks. The forecast model will improve the safety of fire brigade personnel responsible for extinguishing fires inside ground-based vertical steel tanks having protective walls. In the research, the authors place special emphasis on identifying dependence between the heat flow and the wind load. Methods. To achieve this goal, the authors arranged and conducted a series of experiments, collected experimental data on heat flows, and created training and test samples.Results. Dependences between heat flows and environmental factors were identified by constructing adaptive neuro-fuzzy inference systems or adaptive network-based fuzzy inference systems (ANFIS). Various types of membership functions, optimisation and system generation methods were compared and it was found out that for ANFISs, prediction of heat flows with regard to and disregarding wind loads were optimal, if subcluster and hybrid optimisation methods were used, as they had lowest error values for samples.Discussion. The analysis shows that wind speed and tank location can rise temperatures of the air, tank wall and petrol. Therefore, despite the complexity of the analysis, the regard for all these factors makes it possible to identify a safe distance between a burning tank and firefighters.Conclusions. The research made it possible to develop a model for prompt heat flow forecasting with the help of artificial intelligence elements (ANFIS). The results obtained in the course of the work make it possible to increase the efficiency of prompt forecasting of the dynamic behaviour of fire inside tanks and tank farms and optimize managerial decision-making by responsible persons.

This paper examines the Electro-MHD flow and heat transfer of a third grade fluid passing through a porous channel. An unidirectional and one-dimensional flow is propelled with the aid of lorentz force generated due to interaction of vertically applied magnetic field along with horizontally applied electric field. The equations of momentum and energy governing the third grade fluid flow are transformed to algebraic equation from nonlinear partial differential equation by implementing fully implicit finite difference scheme and solution is obtained by damped-Newton method. Lastly, the problem is simulated using MATLAB and the influence on velocity and temperature profiles with variation of non-dimensional parameters are depicted graphically. The noteworthy findings of this study is that the increasing values of elastic parameter α and non-Newtonian parameter γ diminishes the flow velocity and results in enhancement of temperature profile. A completely contrasting effect is observed for increasing values of strength of electric and magnetic field.

On the basic of consideration of the heat-conduction problem for a semi-bounded space with a temperature profile defined by a parabola with an exponent n, a new concept of construction of constitutive involves the introduction of a local function for a heat flow or for the temperature, with is determined from the heat-conduction equation. The approach proposed made it possible to obtain a number of new integral relation: an improved integral for the temperature momentum, an integral of a quadratic heat flow, and an integral of a quadratic temperature function. Two Schemes of optimizing the exponent n with the use of the error norms E1 and are proposed. As compared to the Langford norm, the indicated error norms made it possible to substantially increase the approximation accuracy of solutions of the problem posed.

The boundary layer flow of temperature-dependent variable thermal conductivity and dynamic viscosity on flow, heat, and mass transfer of magnetized and dissipative Casson fluid over a slenderized stretching sheet has been studied. The model explores the Cattaneo-Christov heat flux paradox instead of the Fourier’s law plus the stratifications impact. The variable temperature-dependent plastic dynamic viscosity and thermal conductivity were assumed to vary as a linear function of temperature. The governing systems of equations in PDEs were transformed into non-linear ordinary differential equations using the suitable similarity transformations, hence the approximate solutions were obtained using Chebyshev Spectral Collocation Method (CSCM). Effects of pertinent flow parameters on concentration, temperature, and velocity profiles are presented graphically and tabled, therein, thermal relaxation and wall thickness parameters slow down the distribution of the flowing fluid. A rise in Casson parameter, temperature-dependent thermal conductivity, and velocity power index parameter increases the skin friction thus leading to a decrease in energy and mass gradient at the wall, also, temperature gradient attain maximum within 0.2 - 1.0 variation of Casson parameter.

In this paper, the development features of a single free jet of hightemperature nitrogen interacting with a flat surface were studied. Calculation of the heat exchange process during heating by the attacking jets is very difficult to implement analytically due to complexity of the gas-dynamic processes occurring both in a single jet and in a system of jets interacting with the metal. The computational difficulties are aggravated by the fact that when interacting with the surface the jet as such disappears. The flat (fan) flow interacts with the surface: form, aerodynamic properties and thermal state of the flow strongly differ from those of the original jet. The studies were conducted on the basis of numerical simulation in the FloEFD software and computing complex for multiphysical simulation based on solution of the equations of gas dynamics and heat transfer. The solved system of equations consisted of Navier-Stokes equations, equations of energy and continuity and was supplemented by k – ε turbulence model. A three-dimensional model was developed for simulation, the necessary properties, initial and boundary conditions were specified. In the study of aerodynamics of a single high-temperature jet interacting with the surface, the main defining values were: nitrogen flow rate from the nozzle U0 , nitrogen temperature T, internal diameter of the nozzle d0 , distance from the nozzle section to the surface h, distance from the critical point (point of intersection of the jet axis with the surface) along the flow radius r. Data on the gas velocity decrease as the jet develops due to the loss of initial energy to engage the motionless surrounding gas in motion, is presented. The studies have shown that increase in the initial velocity of gas outflow brings the area of higher velocities closer to the surface both in the jet itself and in the fan jet. This factor contributes to heat transfer intensification. In addition, high speeds increase the total thickness of the fan flow and reduce the thickness of hydrodynamic boundary layer, which increases with distance from the critical point.

The effects of chemical reaction and thermal-diffusion mixed convection heat and mass transfer for Hiemenz flow through porous media has been studied. The plate is embedded in a uniform porous medium in order to allow for possible fluid wall suction or blowing and has a power-law variation of both the wall temperature and concentration. We used similarity solution to transform the system of partial differential equations, into a boundary value problem of coupled ordinary differential equations. We then solve these ordinary differential equations by a MATLAB routine bvp4c. We conducted a parametric study of all involved parameters and the results represented graphically.

A three-dimensional model was developed to simulate the laminar flow and convective heat transfer in rectangular silicon microchannels，which have hydraulic diameter of 95.3，92.3 ,85.8 , 80 and 75μm respectively．The rationality of the simulation methods and results were validated by comparing with experimental data. The simulation results indicate that the aspect ratio has a significant impact on the Poiseuille number. Conventional fluid flow theory is fit for researching the fluid flow in microchannels, Po is a constant that is not dependent on the Reynolds number.

Introduction (statement of the problem and relevance). Starting an internal combustion engine (ICE) at negative ambient temperatures is difficult for a number of reasons. A decrease in the volatility of gasoline leads to the liquid fuel deposition on the cylinder walls, as a result of which the fuel-air mixture ignition is difficult or impossible. Another reason is the geometric dimensions reduction of the gaps in the plain bearings, which is a consequence of the use of materials with different thermal expansion coefficients in the engine design. The high kinematic viscosity of the oil creates a higher hydraulic resistance in the system. These factors complicate the engine oil flow to friction pairs, which can lead to an oil starvation and bearing shell life reduction.The purpose of the research was to determine the optimal pre-heating mode from the point of view of the process energy efficiency and the preservation of the engine resource.Methodology and research methods. To control the thermal state, the internal combustion engine and the cooling circuit were equipped with measuring equipment. The values of temperature, pressure and volume flow sensors were recorded. To implement the pre-heating modes proposed in the article, an engineering engine control unit was used, which allowed making changes in the basic software configuration.Scientific novelty and results. An alternative method of pre-heating has been proposed, including preheating of the engine oil-water heat exchanger to reduce the time for reaching the minimum oil pressure at the main gallery inlet during a cold start. The article provides descriptions of the regular and proposed pre-heating cycles, their assessment in accordance with the represented criteria. Experimental data on pre-heating cycles and cold starts at an ambient temperature of –40°C are presented. The necessity of warming up the engine standard water-oil heat exchanger before a cold start has been experimentally proved, the curves of pressure changes at the main gallery inlet, depending on the pre-heating mode, are given.Practical significance. Reducing the negative influence of cold start on the ICE resource.

Changes in cyclic electron flow (CEF) around PSI activity after exposing grape (Vitis vinifera L.) seedling leaves to the combined stress of high temperature (HT) and high light (HL) were investigated. The PSII potential quantum efficiency (Fv/Fm) decreased significantly under exposure to HT, and this decrease was greater when HT was combined with HL, whereas the PSI activity maintained stable. HT enhanced CEF mediated by NAD(P)H dehydrogenase remarkably. Compared with the control leaves, the half-time of P700+ re-reduction decreased during the HT treatment; this decrease was even more pronounced under the combined stress, implying significantly enhanced CEF as a result of the treatment. However, the heat-induced increase in nonphotochemical quenching (NPQ) was greater under HL, accompanied by a greater enhancement in high-energy state quenching. These results suggest that the combined stress of HT and HL resulted in severe PSII photoinhibition, whereas CEF showed plasticity in its response to environmental stress and played an important role in PSII and PSI photoprotection through accelerating generation of the thylakoid proton gradient and the induction of NPQ.

Objective: To develop and validate a stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method for the determination of colchicine in bulk and ethosomal gel nano-formulation.Methods: The chromatographic conditions were optimized using stainless steel Hypersil Gold C-18 analytical column with the dimensions of 250 mm x 4.6 mm ID x 5 µm. The mobile phase consisted of acetonitrile and ammonium acetate buffer (20 mmol/l, pH=4.85) in the ratio of 32:68 v/v. The flow rate was set at 1 ml/min and the detection wavelength was 353 nm. The column was maintained at 30 °C and the injection volume was 10 µl. The stability of colchicine in different conditions was investigated by exposing the drug to stress degradation using acid, base, oxidation, heat and light.Results: There was no interference from excipients, impurities, dissolution media or degradation products at the retention time of colchicine 5.9 min indicating the specificity of the method. The limit of detection (LOD) and the limit of quantification (LOQ) were 8.64 ng/ml and 26.17 ng/ml respectively. The drug showed good stability under heat, acid, oxidation and light, but substantial degradation was observed under alkali condition. The procedure was validated for specificity, linearity, accuracy and precision.Conclusion: A simple, rapid, specific and stability-indicating HPLC–UV method for the determination of colchicine in the pure and ethosomal gel was successfully developed. The developed method was statistically confirmed to be accurate, precise, and reproducible.

Nanofluid flow through non-corrugated and corrugated channels is studied using a two-dimensional (2D) and three dimensions (3D) numerical simplification. Due to the high computational costs of a full 3D grid model, the 2D approach offer a more practical advantage. However, little information about its validity is available. The aim of this study is to explore to which extent 2D simulations can describe the flow within a 3D geometry, and to investigate how effective the commonly used 2D numerical simplification is in nanofluid flow through non-corrugated and corrugated channels. A case study has implemented with 2D and 3D mesh models to compare their results taking into consideration the analysis of heat transfer and pressure drop. A simulation has been carried out using Ansys fluent software to compare the results for different Reynolds Numbers ranges from 10000 to 30000 and different geometries non-corrugated, semicircle and rectangular channels. The results show that for non-corrugated channel there is a slight difference between 2D and 3D results for all Reynolds number ranges, while for both semicircle and rectangular corrugated channels, the difference becomes larger for high Reynold’s Number.

In the traditional heap leaching of rare earth minerals, the top of the rare earth pile is covered with leaching liquid. This creates trouble for vegetation restoration carried out timely on the top of the pile. In order to solve this trouble, a novel pile structure into which leaching liquid is laterally injected is proposed for heap leaching of rare earth. In this study, a laboratory test is carried out to study the formation and distribution of preferential flow paths for the rare earth pile under a horizontal liquid injection condition. Furthermore, numerical simulations based on a dual-permeability model are conducted to investigate the influence of the preferential flow paths on the seepage characteristics in the rare earth pile. The results show that, under the horizontal liquid injection condition, the fine particles of the rare earth move away from the liquid injection end and also toward the lower part of the pile. The migration of the fine particles results in the formation and connection of macropore, thereby generating preferential flow paths in the rare earth pile. The preferential flow paths are mainly distributed in the lower part of the pile near the liquid injection end. This causes the fluid in the lower part of the pile to seep faster significantly than that in the upper part. Within the region where the preferential flow paths develop, the seepage in the early stage of the horizontal liquid injection is dominated by preferential flow. The preferential flow is more significant at the locations farther away from the liquid injection end.

The process of daily variation in tomato stem diameter is examined in order to justify the use of this parameter to control drip irrigation. Changes in the size of individual plant parts depend on the provision of water, light, heat and nutrients to the production process. Therefore, such plant parameters as leaf temperature, xylem flow rate, fruit and stem diameter can be indicators of availability of necessary resources. The research was carried out in Novosibirsk region in June - September 2020. The value of the range of daily variations in stem diameter, which has a close relationship to relative soil moisture, was used as an indicator of plant water stress. The source of the information is the results of measurements of soil moisture and stem diameter growth of tomato. Experiments to assess the effect of water deficit on stem parameters were carried out on a plant set out in the open ground separately from the rest. Artificial water stress conditions were created by watering once a week. Data were collected using a PM-11z phytomonitor, soil moisture and stem diameter growth sensors. The results of measurements were processed in Microsoft Office Excel program. It was found that the range of daily fluctuations of stem diameter growth depends on moisture availability. When soil moisture is below 30%, the plant experiences water stress and the range of stem diameter fluctuations increases. The maximum growth in stem diameter was observed at 7-10 a.m. and the minimum at 13-15 p.m. local time. The difference between the maximum and minimum of the daily stem diameter increase characterizes the range of the daily stem diameter difference, which correlates closely with soil moisture. The correlation coefficient between them is 0.72. The limit for the daily stem diameter difference is 0.025 mm at 30% soil moisture. If the actual value of this parameter exceeds the limit value, the irrigation system can be activated. The implementation of this approach makes it possible to automate the irrigation process and to take into account the indicator that signals water stress of the plant.

Objective. To compare the cardioprotective effcacy of a preservation solution based on Krebs–Henseleit buffer and HTK solution in the model of heterotopic heart transplantation in rat.Design and methods. A study was conducted on 12 Wistar rats. The animals were divided into groups depending on the preservation solution used: 1) Krebs–Henseleit buffer-based solution (n = 7), 2) HTK (n = 5). Each experiment consisted of collecting donor heart, preserving it with an appropriate cardioplegic solution, heterotopic transplantation into a recipient rat followed by explantation and evaluation of left ventricular contractility using the Langendorff model and histochemical assessment of the irreversible myocardial damage. Coronary blood flow in the donor heart was assessed in vivo using ultrasound doppler flowmetry. After 3 hours, the donor heart was explanted and connected to the Langendorff apparatus to assess left ventricular contractility, and the myocardium was subjected to histochemical staining with 1 % triphenyltetrazolium chloride for the assessment of the irreversible myocardial damage.Results. In the group of Krebs–Henseleit buffer-based cardioplegic solution, 7 experiments were performed. Myocardial infarct size was 3,5 ± 1,2%, the coronary flow rate was 4,5 ± 1,3 ml/min, and the developed left ventricular pressure of the donor heart was 70 ± 6,3 mmHg at diastolic left ventricular pressure of 10 mmHg. In the HTK solution group (n = 5), in all of the experiments after the start of blood flow, the transplanted heart did not begin to contract, and all 5 hearts remained in an asystole state. Therefore, after the end of the 3-hour reperfusion period, the assessment of the contractility of the left ventricle using the Langendorff apparatus was not carried out. Coronary flow rate was only 0,4 ± 0,1 ml/min, probably resulting from inadequate cardioprotection with HTK solution. Due to the lack of adequate reperfusion, the accurate assessment of the irreversible myocardial damage was impossible in the HTK solution group.Conclusions. The technique of heterotopic heart transplantation in rats is adequate and informative for the study of ischemia-reperfusion myocardial damage as well as for the study of the effectiveness of cardioplegic and cardiac preservation solutions. Cardioplegic solution based on Krebs– Henseleit buffer demonstrated greater cardioprotective effectiveness in our model compared to HTK solution.

The relevance of the research topic. Morpho-functional changes in peripheral circulation established in type 1 diabetes mellitus correlate with changes in central hemodynamics, allowing the use of microcirculation indicators as diagnostic and prognostic criteria for assessing the degree of functional vascular disorders.Purpose – identifcation of microcirculation features of the blood by the method of laser Doppler flowmetry in children with different experience of type 1 diabetes in key age categories.Methods. The study included 67 children with type 1 diabetes mellitus aged 12-15 years with an experience of the disease from six months to ten years. The comparison group consisted of 38 healthy children. The state of the microvasculature was assessed by laser Doppler flowmetry using a laser analyzer for capillary blood flow LAKK-OP.Results. In children with an experience of type 1 diabetes of less than two years, microcirculation disorders in periodontal tissues correspond to the hyperemic form, accompanied by increased perfusion, a decrease in the amplitude of low-frequency oscillations, increased heart rate, high blood flling, and blood flow bypass. For children with an endocrinopathy experience of more than three years, microcirculation disorders correspond to a stagnant form, combined with a decrease in perfusion due to stagnation of blood in the venular link, endothelial domination with suppression of neurogenic and cardiac fluctuations, low effciency and redistribution of blood flow in favor of the nutritive link.Summary. With the increase in experience, the degree of compensation of type 1 diabetes, the progression of diabetic microangiopathy, it is advisable to designate two stages of development of microcirculatory disorders. Early - compensatory with active adaptation, including neurogenic and endothelial regulation mechanisms. Late - decompensation with passive adaptation, supporting the effectiveness of microcirculation due to myogenic control of regulation, shunting and increasing the rate of blood outflow.

Relevance. Morpho-functional changes in peripheral circulation established in type 1 diabetes mellitus correlate with changes in central hemodynamics, allowing the use of microcirculation indicators as diagnostic and prognostic criteria for assessing the degree of functional vascular disorders. Identifcation of microcirculation features of the blood by the method of laser Doppler flowmetry in children with different experience of type 1 diabetes in key age categories.Materials and methods. The study included 67 children with type 1 diabetes mellitus aged 12-15 years with an experience of the disease from six months to ten years. The comparison group consisted of 38 healthy children. The state of the microvasculature was assessed by laser Doppler flowmetry using a laser analyzer for capillary blood flow LAKK-OP.Results. In children with an experience of type 1 diabetes of less than two years, microcirculation disorders in periodontal tissues correspond to the hyperemic form, accompanied by increased perfusion, a decrease in the amplitude of low-frequency oscillations, increased heart rate, high blood flling, and blood flow bypass. For children with an endocrinopathy experience of more than three years, microcirculation disorders correspond to a stagnant form, combined with a decrease in perfusion due to stagnation of blood in the venular link, endothelial domination with suppression of neurogenic and cardiac fluctuations, low efciency and redistribution of blood flow in favor of the nutritive link.Conclusions. With the increase in experience, the degree of compensation of type 1 diabetes, the progression of diabetic microangiopathy, it is advisable to designate two stages of development of microcirculatory disorders. Early – compensatory with active adaptation, including neurogenic and endothelial regulation mechanisms. Late – decompensation with passive adaptation, supporting the effectiveness of microcirculation due to myogenic control of regulation, shunting and increasing the rate of blood outflow.

Epicardial coronary arteries are the subject of the majority of research attention and treatment techniques. This is because interventional cardiologists focus on relieving the obstructions in epicardial coronary arteries which are easily seen on angiography. On the contrary, the coronary microvasculature receives less attention. The heart microvasculature, which consists of capillaries and arterioles, is negatively affected when the epicardial coronary artery becomes blocked. When the occlusion is relieved, sometimes the blood flow to the ischemic tissue still remains impeded, a phenomenon known as no-reflow. This review article aims to provide an in-depth understanding of the pathophysiology and management strategies needed to tackle this life-threatening phenomenon.

Abstract Multiple myeloma (MM) is an incurable malignancy characterized by the accumulation of terminally differentiated plasma cells in the bone marrow, usually accompanied by continuous monoclonal immunoglobulin production. This production requires proper folding and assembly of immunoglobulin chains, conducted by disulfide bonds formation in the endoplasmic reticulum (ER). Disulfide bonds are formed via electron transfer from thiol groups in a protein relay system, from protein disulfide isomerase (PDI) to ER oxidoreductase1 (ERO1) and finally to molecular oxygen, generating one molecule of hydrogen peroxide (H2O2) as secondary product for each disulfide bond formed. The high ER protein-folding demand usually placed on MM cells predisposes them to accumulation of unfolded proteins, which results in ER stress and also oxidative stress, both capable to induce cell death. Cellular defense systems for these specific forms of stress, known as the unfolded protein response (UPR) and oxidative stress response, have been explored as therapeutic targets for MM. 15-Deoxy-D12,14-prostaglandin J2 (15d-PGJ2) is a member of J2 series of PGs, characterized by the presence of an electrophilic carbonyl group in the cyclopentenone ring, which confers them biological properties that are different from those of other components of the PG family. These include anti-inflammatory, anti-proliferative and pro-apoptotic activities, depending on the concentration and cell type. Starting from the observation that15d-PGJ2 is emerging as the most potent antineoplastic agent of the J2 series of PGs, in the present study we investigated its effect on MM cells. We found that 15d-PGJ2 displayed superior cytotoxicity than dexamethasone in MM cell lines. Using flow cytometry, we demonstrated intracellular reactive oxygen species (ROS) formation in these cells after 15d-PGJ2 treatment, which was associated with an augmented ratio of oxidized to reduced glutathione (GSH), indicating that the cells were under oxidative stress. Due to its electrophilic property, it has been suggested that 15d-PGJ2 may directly react with GSH and/or other thiol compounds. Such reactions would deplete essential cellular antioxidants thereby leading to oxidative stress in MM cells. Results from qPCR analysis showed that 15d-PGJ2 induces transcription of UPR genes, including GRP78, GRP94, EDEM1 and also PRDX4. GRP78/BiP and GRP94 are ER-resident chaperones, members of the heat shock protein (HSP) 70 family and HSP 90 family, respectively. These chaperones were described to bind to immunoglobulin chains assisting their assembly. The ER degradation-enhancer mannosidase-like protein 1 (Edem1) is involved in the degradation of misfolded proteins to prevent their aggregation and cytotoxicity. PRDX4 encodes the ER-localized peroxiredoxin (Prx) IV, an enzyme not yet recognized as an UPR component, but recently demonstrated to use the H2O2 produced by ERO1 during disulfide bond formation to generate another pair of disulfide, with the additional benefit of reducing H2O2 to water. Increased transcription of these genes indicates an attempt to preserve ER-processing function and MM cells survival in response to accumulated misfolded proteins. In this regard, 15d-PGJ2-induced oxidative stress, by provoking oxidative modification of proteins, could have intensified the formation of misfolded proteins, thereby activating UPR signaling. In agreement with 15d-PGJ2-mediated accumulation of misfolded proteins, which are prevented from progressing further along the secretory pathway, our results from ELISA have shown a massive decrease in the concentration of light chain immunoglobulin secreted by MM cells in the presence of 15d-PGJ2, but not dexamethasone. These data suggest that 15d-PGJ2 favors ROS accumulation and protein misfolding, especially threatening the survival of cells that have a high protein-folding load and/or are susceptible to oxidative stress. In this sense, multiple myeloma and related disorders may benefit from 15d-PGJ2 therapy. Disclosures: Demasi: FAPESP: Research Funding. Napimoga:FAPESP: Research Funding.

Heat transfer augmentation for Taylor-Couette flows between concentric cylinders have been investigated experimentally. Due to its importance and widespread in wide industrial applications such as heat exchangers, reactors, well dinning, packed beds, compressors and gas turbines, chemical industries, etc. Different variables are investigated in the present work as follow, Rayleigh number (2×106 ≤ Ra ≤ 2×107), Taylors number (0 ≤ Ta ≤ 2.4×1010), Richardson Number (0.004 ≤ Ri ≤ 0.4) and nanoparticles volume fractions(φ) of Al2O3 with water base (0 % ≤ φ ≤ 0.225 %) in which prepared in two step method. The enhancement in heat transfer was 16.5% to 24% due to rising the concentration of Nano fluids of Al2O3-pure water from 0% to 0.225%. Also, the Nusselt number increases with increasing Rayleigh and Richardson numbers. Finally, a correlation was deduced to describe the experimental work and linked the studied parameters with difference less than 13.5 %. The comparison between experimental work and previous works found a good agreement between them.

Pulmonary hypertension (PH) is defned as an increase in mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg at rest as assessed by right heart catheterization (RHC). The symptoms of PH are non-specifc and mainly related to progressive right ventricular (RV) dysfunction. In some patients the clinical presentation may be related to mechanical complications of PH andthe abnormal distribution of blood flow in the pulmonary vascular bed, include hemoptysis related to rupture of hypertrophied bronchial arteries. Hemoptysis is a serious complication that is rarely reported in patients with pulmonary arterial hypertension (PAH). Hemoptysis severity ranges from mild to very severe leading tosudden death. Hemoptysis are reported to be a terminal stage ofa complication due to PAH with prevalence is variable, from 1% to 6%. Although the incidence is quite rare, the presence of recurrent hemoptysis in patients with pulmonary hypertension is a sign of poor prognosis. Bronchial artery embolization is suggested as an acute emergency procedure in the case of severe hemoptysis or as elective intervention in cases of frequent mild or moderate episodes.

The Murmansk region is characterized by a number of specific climatic and geographical features: a polar night, a long snowy period, an unstable geo-heliophysical setting. All of the above factors have a negative impact on children with disabilities. The article describes the application of the method of analysis of heart rate variability to assess the dynamic changes in the functional state of the body of preschool children with general speech underdevelopment, as well as with stuttering. The work was carried out on the Kola Peninsula in the period of the exit from the «polar night», when exacerbations of somatic diseases are most often recorded in children, and there is a decrease in the immunological reactivity and adaptation potential. The main purpose of this work was to conduct research on the selection of methods for the functional diagnosis of a child’s body in the Kola North to track the state of the state during the educational process on the basis of a preschool institution during the most unfavorable periods. Functional diagnostics included weekly dynamic measurements of the functional status of children of both groups on a non-invasive cardiac rhythmograph, followed by mathematical processing of the main cardiorhythmographic parameters. The use of heart rate variability analysis makes it possible to identify differences in the functional state of preschool children with various speech disorders associated with the nosological structure of the defect. In addition, the use of this method allows you to track changes in the state of children in the course of the educational process in preschool institutions and to adjust the flow of information, taking into account the individual characteristics and adaptive capacities of children with speech disorders.

Unsteady flow of Casson fluid past through a vertical channel has been studied by some researchers due to its importance of applications in science and technology. Therefore, the main purpose of this paper is to obtain exact solutions for unsteady free convection flows of Casson fluid with effects of magnetohydrodynamics (MHD) past through vertical channel. This paper is continued study from published article [18] with additional effects of magnetohydrodynamics (MHD). Dimensional governing equations are converted into dimensionless forms by using appropriate dimensionless variables. Dimensionless parameters are obtained through dimensionless process such as Casson fluid, time, Prandtl number, Grashof number and magnetic field. Laplace transform method is used to solve the dimensionless equations with associated initial and boundary conditions. Solutions for velocity and temperature profiles are obtained. Skin friction and Nusselt number are also calculated. The obtained analytical results for velocity and temperature are plotted graphically to discuss the influence of dimensionless parameters on profiles. It is observed that fluid velocity increases with increases of Grashof number, Gr and time, t whereas it decreases with increases of Casson parameter, γ, magnetic field parameter, M and Prandtl number, Pr. Besides that, it is found that temperature profiles decrease with high value of Prandtl number, Pr while increases with high value of time, t. In order to validate the results, the obtained results in limiting cases are compared with the published results and it is found to be in a mutual agreement.

BACKGROUND Coronary heart disease is one of the main causes of the population’s disability and mortality in Russia and abroad. Revascularization with coronary stents in the course of the most suitable drug therapy is one of the most important treatments of coronary heart disease. It is essential to pay special attention to the research results of using modern stents, in particular, the frst Russian drug-eluting stent “CALYPSO”.AIM OF STUDY To study immediate and medium-term results of Limus-eluting stents procedure in patients with acute coronary syndrome.MATERIAL AND METHODS 304 patients with acute coronary syndrome were included into the research and were divided into 2 groups. The frst group consisted of 156 patients with CALYPSO stent (Angioline, Russia). The other group consisted of 148 patients who had undergone revascularization with the XIENCE stent (Abbot Vascular, USA). Their health state was monitored via phone 3, 6, 9 and 12 months later. After the discharge from the hospital, the drug therapy was prescribed, and instrumental procedures of diagnostics were planned for the period of 9–12 months. According to the results of the examination, patients with suspected or confrmed myocardial ischemia underwent follow-up coronary angiography.RESULTS The success of implantation was 98.63% in the frst group, and 99.4% in the second group. One fatal outcome occurred in both groups during hospitalization (thus making 0.64% и 0.67%). The placement of the CALYPSO stent in distal parts of coronary arteries requested signifcantly less time and contrast. Medium-term results of stenting in both groups appeared to be comparable (thus, all cause death 3 (1.92%) and 2 (1.35%), restenosis >50% 3 (1.92%) and 3 (2 %), late thrombosis — 0 in both groups, cardiac death — 0 in both groups. End points (MACE) in both groups were 1.28% and 0.67%.CONCLUSION Taking into consideration immediate and medium-term results it can be concluded that domestic stents (CALYPSO) are comparable to stents XIENCE. The CALYPSO stent is more advantageous than the XIENCE in the delivery to the lesion focus while performing the procedure in distal flow.

Background: With the approval of detachable coils in 1995, endovascular treatment of intracranial aneurysms has become an alternative to surgical clip ligation. Despite the introduction of “modified” coils and advanced techniques such as stent-assisted and balloon-assisted coiling, coil embolization has major limitations because of inability to completely and permanently occlude all aneurysms. As stents were being developed for intracranial use, it was hypothesized that stents could be utilized to divert flow “away” from the aneurysm “back” into the parent vessel, and the concept of “endovascular flow diversion” was proposed. This study aims to report our experience with cerebral aneurysms, which may improve in the treatment with the flow-diverter stent and follow up (1). Methods: This study was conducted in consecutive series of 23 patients. 23 procedures were performed for treating these patients in Ha Noi heart hospital from January 2019 to January 2020. 23 flow diverter stents (Pipeline) were used. Aneurysms morphology, stent patency and cerebral parenchyma before and after intervention were analyzed on images of digital subtraction angiography (DSA), computed tomography (CT) and magnetic resonance (MR). The follow-up data after 3–6 months and 12 months were recorded. Results: In 23 patients (8 men, 15 women), aneurysms of internal carotid artery were mostly common (95.7%), especially in cavernous segments. 13 cases (74%) had saccular aneurysms, and 2 cases (9%) had multiple aneurysms, and only 3 cases (13%) had fusiform aneurysms. Endovascular treatment was successfully performed at rate of 100%.. Mortality and morbidity rates were 0% and 0%, respectively. MRI and MSCT follow-up at 3 months showed complete or incomplete occlusions of aneurysms was 26.1% or 34.8%, respectively. Conclusions: Deployment of flow diverter stent is safe and effective with high rate of successful and low procedural complications

The problem of hydration and transport processes in fresh concrete is strongly coupled and non- inear, and therefore, very difficult for a numerical modelling. Physically accurate results can be obtained using fine-scale simulations, which are, however, extremely time consuming. Therefore, there is an interest in developing new physically accurate and computationally effective models. In this paper, a new fully coupled two-scale (meso-macro) homogenization framework for modelling of simultaneous heat transfer, moisture flows, and hydration phenomena in fresh concrete is proposed. A modified mesoscalemodelisfirstintroduced. Inthismodel, concreteisassumedasacompositematerialwithtwo periodically distributed mesoscale components, cement paste and aggregates. A homogenized model is then derived by an upscaling method from the mesoscale model. The coefficients for the homogenized model are obtained from the solution of a periodic cell problem. For solving the periodic cell problem, two approaches are used – a standard finite element method and a simplified closed-form approximation taken from literature. The homogenization framework is then implemented in MATLAB environment and finally employed for illustrative numerical experiments, which verify that the homogenized model provides physically accurate results comparable with the results obtained by the mesoscale model. Moreover, it is verified that, using the homogenization framework with a closed-form approach to the periodic cell problem, significant computational cost savings can be achieved.

Cardiovascular toxicity is one of the important problems of clinical oncology. Atherosclerosis progression was demonstrated in patients with cancer and chemotherapy.Te aim– to evaluate the vascular wall characteristics and to determine the predictors of AS of brachiocephalic arteries progression during anticancer therapy in patients with breast cancer.Methods.Te study involved 43 patients with newly diagnosed breast cancer (BC) (II–III stage) with overexpression of HER2; median age 50 (40;57) years. All patients underwent neoadjuvant drug therapy with antracyclines, taxanes and trastuzumab followed by surgery, radiation and hormone therapy according to the indications. Before anticancer therapy the general clinical examination was conducted and lipid profle, plasma lipoprotein (a) [Lp(a)] level, titres of autoantibodies IgM and IgG to lipoproteins and their oxidized derivatives were estimated. Te vascular wall stiffness (pulse wave velocity on the carotid-femoral (PWVcf) and shoulder-ankle (PWVsa) segments, the central pressure, carotid intima-media thickness (CIMT) and the degree of stenosis of the brachiocephalic arteries) were determined at baseline and at each stage of anticancer therapy. Te atherosclerosis progression was determined if the new stenosis (≥15%) or increase of preexisting stenosis (≥5%) were revealed; CIMT increase ≥ 0.1 mm. Te parameters of cellular immunity (peripheral blood lymphocyte phenotyping via direct immunofluorescence and flow cytometry), lipid spectrum parameters, serum concentration of Lp (a), autoantibodies IgM and IgG against lipoproteins and their oxidized derivatives, as well as PWVсf and PWVsa were assessed in 17 BC patients before the onset of neoadjuvant therapy and in 20 healthy women.Results.BC patients and healthy women were comparable in traditional cardiovascular risk factors but differed in PWVsa and PWVcf levels (p<0.05). In BC patients the activation of T-cell immunity with the stimulation of both subpopulations with pro-inflammatory and regulatory properties was observed (p<0.05). Te direct correlations between the content of activated T-lymphocytes (T-act), T-helpers (T) 1 and PWVsa (p<0.05), as well as T-act, T1 and T2 and PWVcf (p<0.05) were revealed in the general group. Te decrease of systolic blood pressure (SBP), central SBP (SBPc), central diastolic blood pressure (DBPc), PWVcf and PWVsa levels accompanied with a temporary heart rate increase were observed during anticancer therapy; SBP, SBPc, PWVcf levels restored by the end of the follow-up period. Te CIMT increase was detected in 22 (51%), and the atherosclerosis progression in 26 (60%) BC patients during anticancer therapy. Lp (a) level above 12.8 mg/dl was associated with CIMT increase (p<0.05). Age > 48 years and radiation therapy were risk factors for CIMT increase and atherosclerosis progression (p<0.05), respectively.Conclusions. Te vascular stiffness is increased in BC patients, which is associated with the activation of effector subpopulations of T-lymphocytes and the elevation of circulating level of both pro-atherogenic and anti-atherogenic T-cells. Te level of Lp (a) above 12.8 mg/dl is associated with atherosclerosis progression, which requires further research. Age and radiation therapy are the risk factors for atherosclerosis progression during anticancer therapy.

According to modern technologies of construction and operation of transport tunnels, it is assumed in the present work that drainage of water does not occur inside the membrane in the area of reinforced coating of the tunnel and here takes place a non-stationary process of transfer of hygroscopic mass (moisture) together with а similar process of heat transfer between the ventilation stream and the surrounding mining massif. Thus, we have to deal only with the sorption mass content in the pores of the massif and the water in the explicit form in the tunnels can only be in exceptional cases as local sources and therefore, their influence on the ventilation flow should be considered separately. The paper provides results of mathematical modeling of heat and mass transfer processes as well as graphs and nomograms, which can be used to define non-stationary coefficients of the heat and mass transmission required for thermal physics calculation of underground ventilation. The additional flows initiated by the Soret and Dufour effects usually strengthen the main flows, but in practice one can find a case where it is not necessary to take into account the effect of additional flows. Based on the analysis of processes, the criteria that determine the numerical value of these show the case when accounting for additional flows of Soret and Dufour is mandatory. The marked effects can be ignored when 106 Lα=1.

Abstract A general method of solving the drift kinetic equation is developed for an axisymmetric magnetic field. Expanding a distribution function in general moments a set of ordinary differential equations are obtained. Successively expanding the moments and magnetic-field involved quantities in Fourier series, a set of linear algebraic equations is obtained. The set of full (Maxwellian and non-Maxwellian) moment equations is solved to express the density, temperature, and flow velocity perturbations in terms of radial gradients of equilibrium pressure and temperature. Closure relations that connect parallel heat flux density and viscosity to the radial gradients and parallel gradients of temperature and flow velocity, are also obtained by solving the non-Maxwellian moment equations. The closure relations combined with the linearized fluid equations reproduce the same solution obtained directly from the full moment equations. The method can be generalized to derive closures and transport for an electron-ion plasma and a multi-ion plasma in a general

This article describes an innovative design of a solar-wind generator for a distributed energy Hyperloop high-speed system. The knowhow of this development is to mount flexible silicon solar panels (SP) on wind turbine blades, thus optimizing the thermal efficiency of solar panels. The basic dimensions of the wind turbine blades and the maximum internal flow velocities at the blade outlet (tips) are presented. At low wind velocities, it is rational to locate solar panels on the outer end (or the tip) of a blade, rather than along the blade length.The cooling effect can be increased by using materials with low thermal resistance for the SP and blades, or by reducing their thickness.To increase the heat transfer coefficient, it is recommended to use the airflow turbulence on the solar panel surface. In practice, this can be achieved both by changing the operating parameters and by introducing innovative design solutions.For better cooling of solar panels, it is recommended to use the technology of a wind flow sucked into the blade inner cavity. Changing the geometry of the outer end (tip) of the blades and the use of deflectors also give a better panel cooling parameters.

Late ripening berry dehydration is an important phenomenon that occurs through grape berry water loss due to the alteration of the fruit water budget when transpiration and potential water back flow to the plant exceed the import of water into the berry through the phloem and xylem. Berry shrivelling can have a significant economic impact, reducing yields by ≥25 % with consequences on berry composition and the resulting wine. Its occurrence and consequences are expected to increase due to predicted climate change, shifting grape development and ripening into warmer periods (i.e., heat waves and drought events).

The authors studied the state of blood flow in the system of arterial vessels of the head and neck in 30 patients with hypertensive disease (HD) stage I, arterial hypertension (AH), 1st degree – in 26 (86,7 %) and 2nd degree – in 4 (13,3 %) people, with comorbid migraine (M) – in 14 (46,7 %) people and tension-type headache (TTH) – in 16 (53,3 %) people, triplex scanning of extra- and intracranial vessels was performed and measurement of arterial blood pressure was conducted. In patients with AH and comorbid M or TTH, decrease in the velocity and volume parameters of blood flow in the arteries at the extracranial and intracranial level, as well as increase in the indexes of blood flow resistance in comparison with the control, were revealed. In patients with AH and TTH, blood flow in the left vertebral artery and right posterior cerebral artery was lower than in patients with AH and M.

The authors studied the state of blood fl ow in the system of venous vessels of the head and neck in 14 patients with hypertensive disease (HD) stage I, arterial hypertension (AH), 1st degree – in 11 (78,6 %) and 2nd degree – in 3 (21,4 %) people, with comorbid migraine (M) – in 8 (57,1 %) people and tension-type headache (TTH) – in 6 (48,9 %) people. Triplex scanning of extra- and intracranial vessels was performed and measurements of venous pressure in the system of deep veins of the upper extremities were made. In patients with AH and comorbid M or TTH, deviations from the venous outfl ow in the vessels of the head and neck were detected. Disorders of the venous outfl ow in patients with hypertension and M are more pronounced in the pool of the internal jugular veins (IJV) and vertebral veins (VV), and in patients with hypertension and TTH - in the pool of VV and superior orbital vein (SOV). In AH and M, the venous pressure in the upper limbs is increased.

Since both “cardiac pump” and “thoracic pump” theories have been proved during cardiopulmonary resuscitation (CPR), the mechanism of forward blood flow during closed chest compression still remains open to question. The cardiac pump seems to work by the direct compression of the cardiac ventricles between the sternum and vertebral column. A pressure gradient created between the ventricle and aorta generates systemic blood flow. However, the thoracic pump mechanism presumes chest compression causes a rise in intrathoracic pressure which generates a blood flow from the thoracic cavity to the systemic circulation. Retrograde blood flow from the right heart into the systemic veins is prevented by a concomitant collapse of veins at the thoracic inlet. We hypothesize that the intrinsic decrease of vascular resistance from the aorta to peripheral arteries and the existence of competent venous valves enable blood to flow unidirectionally by the fluctuation of intravascular pressures during closed chest compression. The purpose of this study is to prove an antegrade arterial blood flow without cardiac compression and intrathoracic pressure changes in an animal cardiac arrest model. We demonstrate that arterial pulses can be developed by using an extracorporeal circuit, resulting in forward blood flow from the aorta through the systemic vasculature. It can be suggested that changes in intravascular pressure provoked by either cardiac or thoracic pump generate systemic blood flow during closed chest compression, while systemic vascular patency and valve function may be required for successful CPR.

In this paper, we are concerned about the nature of information and how to gather and compose data with the help of so called FAIR digital objects (FDOs) in order to transform them to knowledge. FDOs are digital surrogates of real objects. The nature of information is intrinsically linked to the kind of questions one is asking. One might not ask a question or get philosophical about it. Answers depend on the data different disciplines gather about their objects of study. In Statistical Physics, classical Shannon entropy measures system order which in equilibrium just equals the heat exchanged with the environment. In cell biology, each protein carries certain functions which create specific information. Cognitive science describes how organisms perceive their environment via functional sensors and control behavior accordingly. Note that one can have function and control without meaning. In contrast, psychology is concerned with the assessment of our perceptions by assigning meaning and ensuing actions. Finally, philosophy builds logical constructs and formulates principles, in effect transforming facts into complex knowledge. All these statements make sense, but there is an even more concise way. Indeed, Luciano Floridi provides a precise and thorough classification of information in his central oeuvre On the Philosophy of Information (Floridi 2013). Especially, he performs a sequential construction to develop the attributes which data need to have in order to count as knowledge. Semantic information is necessarily well-formed, meaningful and truthful. Well-formed data becomes meaningful by action based-semantics of an autonomous-agent solving the symbol grounding problem (Taddeo and Floridi 2005) interacting with the environment. Knowledge is created then by being informed through relevant data accounted for. We notice that the notion of agency is crucial for defining meaning. The apparent gap between Sciences and Humanities (Bawden and Robinson 2020) is created by the very existence of meaning. Further, meaning depends on interactions & connotations which are commensurate with the effective complexity of the environment of a particular agent resulting in an array of possible definitions. In his classical paper More is different (Anderson 1972) discussed verbatim the hierarchical nature of science. Each level is made of and obeys the laws of its constituents from one level below with the higher-level exhibiting emergent properties like wetness of water assignable only to the whole system. As we rise through the hierarchies, there is a branch of science for each level of complexity; on each complexity level there are objects for which it is appropriate and fitting to build up vocabulary for the respective levels of description leading to formation of disciplinary languages. It is the central idea of causal emergence that on each level there is an optimal degree of coarse graining to define those objects in such a way that causality becomes maximal between them. This means there is emergence of informative higher scales in complex materials extending to biological systems and into the brain with its neural networks representing our thoughts in a hierarchy of neural correlates. A computational toolkit for optimal level prediction and control has been developed (Hoel and Levin 2020) which was conceptually extended to integrated information theory of consciousness (Albantakis et al. 2019). The large gap between sciences and humanities discussed above exhibits itself in a series of small gaps connected to the emergence of informative higher scales. It has been suggested that the origin of life may be identified as a transition in causal structure and information flow (Walker 2014). Integrated information measures globally how much the causal mechanisms of a system reduce the uncertainty about the possible causes for a given state. A measure of “information flow” that accurately captures causal effects has been proposed (Ay and Polani 2008). The state of the art is presented in (Ay et al. 2022) where the link between information and complexity is discussed. Ay et al single out hierarchical systems and interlevel causation. Even further, (Rosas et al. 2020) reconcile conflicting views of emergence via an exact information-theoretic approach to identify causal emergence in multivariate data. As information becomes differentially richer one eventually needs complexity measures beyond {Rn}. One may define generalized metrices on these spaces (Pirr&oacute 2009) measuring information complexity on ever higher hierarchical levels of information. As one rises through hierarchies, information on higher scale is usually gained by coarse graining to arrive at an effective, nevertheless exact description, on the higher scale. It is repeated coarse graining of syntactically well-ordered information layers which eventually leads to semantic information in a process which I conjecture to be reminiscent of renormalization group flow leading to a universal classification scheme. Thus, we identify scientific disciplines and their corresponding data sets as dual universality classes of physical and epistemic structure formation, respectively. Above the semantic gap, we may call this process quantification of the qualitative by semantic metrics. Indeed, (Kolchinsky and Wolpert 2018) explored for the first time quantitative semantic concepts in Physics in their 2018 seminal paper entitled Semantic information, autonomous agency and non-equilibrium statistical physics. Their measures are numeric variants of entropy. Semantic information is identified with ‘the information that a physical system has about its environment that is causally necessary for the system to maintain its own existence over time’. FDOs are employed in these processes in two fundamental ways. For practical implementations of FDO technology, see accompanying abstract (Wittenburg et al. 2022). First, the FAIR principles (Wilkinson et al. 2016) ensure that unconnected pieces of data may be percolated into an integrated data space. Percolation creates the information density needed to feed AI-driven built up of semantic space. Without FDOs we wouldn't have the gravity for this to occur. Second, the very structure of FDOs, capable of symmetry preserving or breaking fusion events into composed entities, makes them homologous to mathematical categories. This will proof to be a powerful tool to unravel the nature of information via analyzing its topological structure algebraically, especially when considering our conjecture concerning universality, classes of information and their possible instantiations on vastly different length and time scales, in effect explaining analogous structure formation.

Transient storage refers to a vital process affecting nutrient retention dynamics. To explore how streambed topography, discharge, and nutrient ambient concentration impact the transient storage and nitrogen retention of the headwater stream, tracer experiments were performed in five reaches of the Yanqi watershed. The one-dimensional transport with inflow and storage model (OTIS) was employed to simulate the solute injection. Transient storage potential was evaluated by transient storage metrics. Moreover, the material balance method was adopted to obtain the amount of nitrogen retention in the respective reach, and the nutrient spiraling metrics were determined to assess the nitrogen retention potential. As revealed from this study, improving transient storage under low flow conditions effectively facilitated nitrogen retention (except for the case of low-head weirs reach), while the erosion of high discharge destroyed the transient storage zone, thereby reducing the nitrogen retention potential. Ecological restoration in the Yanqi watershed could rescue nitrogen retention potential to a natural state under low flow, whereas limitations were identified in nitrogen retention potential under high flow and high ambient concentration.

In the present paper, the simulation of blood flow in the left coronary artery is performed using angiography images of a healthy person. Artery blockage is the most prevailing cause of coronary artery disease (CAD). The presence of blockage inside the artery breaks the continuity of blood supply to the other part of the body and therefore causes for heart attack. In the present study, two different three-dimensional models namely; normal and 50% plaque are used for the numerical studies. Five inlet velocities 0.10, 0.20, 0.50, 0.70 and 0.80 m/s are considered corresponding to different blood flow conditions to study the effect of velocity on the human heart. Finite Volume Method (FVM) based Computational fluid dynamics (CFD) technique is executed for the numerical simulation of blood flow. Hemodynamics factors are computed and compared for the two geometrical models (Normal Vs. Blockage model). Area Average Wall Shear Stress (AAWSS) ranges from 4.1-33.6 Pa at the façade of the Left Anterior Descending (LAD) part of the Left Coronary Artery (LCA) for the constricted artery. The predominantly low WSS index is analogous to the normal artery affirms the existence of plaque. From the medical point of view, this can prove as an excellent factor for early diagnosis of CAD. Therefore, a hindrance can be created in the increasing frequency of myocardial infarction (MI).

0. IntroductionIf we follow the line of much literature surrounding airports and urban mobility, the emphasis often falls on the fact that these spaces are designed to handle the mega-scale and super-human pace of mass transit. Airports have rightly been associated with velocity, as zones of rapid movement managed by enormous processing systems that guide bodies and things in transit (Pascoe; Pearman; Koolhaas; Gordon; Fuller & Harley). Yet this emphasis tends to ignore the spectrum of tempos and flows that are at play in airport terminals — from stillness to the much exalted hyper-rapidity of mobilized publics in the go-go world of commercial aviation.In this photo essay I'd like to pull a different thread and ask whether it's possible to think of aeromobility in terms of “uneven, differential mobility” (Bissell 280). What would it mean to consider waiting and stillness as forms of bodily engagement operating over a number of different scales and temporalities of movement and anticipation, without privileging speed over stillness? Instead of thinking mobility and stillness as diametrically opposed, can we instead conceive of them as occupying a number of different spatio-temporal registers in a dynamic range of mobility? The following is a provisional "visual ethnography" constructed from photographs of air terminal light boxes I have taken over the last five years (in Amsterdam, London, Chicago, Frankfurt, and Miami). Arranged into a "taxonomy of differentiality", each of these images comes from a slightly different angle, mode or directionality. Each view of these still images displayed in billboard-scale light-emitting devices suggests that there are multiple dimensions of visuality and bodily experience at play in these image-objects. The airport is characterized by an abundance of what appears to be empty space. This may be due to the sheer scale of mass transport, but it also arises from a system of active and non-active zones located throughout contemporary terminals. This photo series emphasises the "emptiness" of these overlooked left-over spaces that result from demands of circulation and construction.1. We Move the WorldTo many travellers, airport gate lounges and their surrounding facilities are loaded with a variety of contradictory associations and affects. Their open warehouse banality and hard industrial sterility tune our bodies to the vast technical and commercial systems that are imbricated through almost every aspect of contemporary everyday life.Here at the departure gate the traveller's body comes to a moment's rest. They are granted a short respite from the anxious routines of check in, body scans, security, information processing, passport scanning, itineraries, boarding procedures and wayfaring the terminal. The landside processing system deposits them at this penultimate point before final propulsion into the invisible airways that pipe them into their destination. We hear the broadcasting of boarding times, check-in times, name's of people that break them away from stillness, forcing people to move, to re-arrange themselves, or to hurry up. Along the way the passenger encounters a variety of techno-spatial experiences that sit at odds with the overriding discourse of velocity, speed and efficiency that lie at the centre of our social understanding of air travel. The airline's phantasmagorical projections of itself as guarantor and enabler of mass mobilities coincides uncomfortably with the passenger's own wish-fulfilment of escape and freedom.In this we can agree with the designer Bruce Mau when he suggests that these projection systems, comprised of "openings of every sort — in schedules, in urban space, on clothes, in events, on objects, in sightlines — are all inscribed with the logic of the market” (Mau 7). The advertising slogans and images everywhere communicate the dual concept that the aviation industry can deliver the world to us on time while simultaneously porting us to any part of the world still willing to accept Diners, VISA or American Express. At each point along the way these openings exhort us to stop, to wait in line, to sit still or to be patient. The weird geographies depicted by the light boxes appear like interpenetrating holes in space and time. These travel portals are strangely still, and only activated by the impending promise of movement.Be still and relax. Your destination is on its way. 2. Attentive AttentionAlongside the panoramic widescreen windows that frame the choreography of the tarmac and flight paths outside, appear luminous advertising light boxes. Snapped tightly to grid and locked into strategic sightlines and thoroughfares, these wall pieces are filled with a rotating menu of contemporary airport haiku and ersatz Swiss graphic design.Mechanically conditioned air pumped out of massive tubes creates the atmosphere for a very particular amalgam of daylight, tungsten, and fluorescent light waves. Low-oxygen-emitting indoor plants are no match for the diesel-powered plant rooms that maintain the constant flow of air to every nook and cranny of this massive processing machine. As Rem Koolhaas puts it, "air conditioning has launched the endless building. If architecture separates buildings, air conditioning unites them" (Koolhaas). In Koolhaas's lingo, these are complex "junkspaces" unifying, colliding and coalescing a number of different circulatory systems, temporalities and mobilities.Gillian Fuller reminds us there is a lot of stopping and going and stopping in the global circulatory system typified by air-terminal-space.From the packing of clothes in fixed containers to strapping your belt – tight and low – stillness and all its requisite activities, technologies and behaviours are fundamental to the ‘flow’ architectures that organize the motion of the globalizing multitudes of today (Fuller, "Store" 63). It is precisely this functional stillness organised around the protocols of store and forward that typifies digital systems, the packet switching of network cultures and the junkspace of airports alike.In these zones of transparency where everything is on view, the illuminated windows so proudly brought to us by J C Decaux flash forward to some idealized moment in the future. In this anticipatory moment, the passenger's every fantasy of in-flight service is attended to. The ultimate in attentiveness (think dimmed lights, soft pillows and comfy blankets), this still image is captured from an improbable future suspended behind the plywood and steel seating available in the moment —more reminiscent of park benches in public parks than the silver-service imagined for the discerning traveller.3. We Know ChicagoSelf-motion is itself a demonstration against the earth-binding weight of gravity. If we climb or fly, our defiance is greater (Appleyard 180).The commercial universe of phones, cameras, computer network software, financial instruments, and an array of fancy new gadgets floating in the middle of semi-forgotten transit spaces constitutes a singular interconnected commercial organism. The immense singularity of these claims to knowledge and power loom solemnly before us asserting their rights in the Esperanto of "exclusive rollover minutes", "nationwide long distance", "no roaming charges" and insider local knowledge. The connective tissue that joins one part of the terminal to a commercial centre in downtown Chicago is peeled away, revealing techno-veins and tendrils reaching to the sky. It's a graphic view that offers none of the spectacular openness and flights of fancy associated with the transit lounges located on the departure piers and satellites. Along these circulatory ribbons we experience the still photography and the designer's arrangement of type to attract the eye and lure the body. The blobby diagonals of the telco's logo blend seamlessly with the skyscraper's ribbons of steel, structural exoskeleton and wireless telecommunication cloud.In this plastinated anatomy, the various layers of commercially available techno-space stretch out before the traveller. Here we have no access to the two-way vistas made possible by the gigantic transparent tube structures of the contemporary air terminal. Waiting within the less travelled zones of the circulatory system we find ourselves suspended within the animating system itself. In these arteries and capillaries the flow is spread out and comes close to a halt in the figure of the graphic logo. We know Chicago is connected to us.In the digital logic of packet switching and network effects, there is no reason to privilege the go over the stop, the moving over the waiting. These light box portals do not mirror our bodies, almost at a complete standstill now. Instead they echo the commercial product world that they seek to transfuse us into. What emerges is a new kind of relational aesthetics that speaks to the complex corporeal, temporal, and architectural dimensions of stillness and movement in transit zones: like "a game, whose forms, patterns and functions develop and evolve according to periods and social contexts” (Bourriaud 11). 4. Machine in the CaféIs there a possible line of investigation suggested by the fact that sound waves become visible on the fuselage of jet planes just before they break the sound barrier? Does this suggest that the various human senses are translatable one into the other at various intensities (McLuhan 180)?Here, the technological imaginary contrasts itself with the techno alfresco dining area enclosed safely behind plate glass. Inside the cafes and bars, the best businesses in the world roll out their biggest guns to demonstrate the power, speed and scale of their network coverage (Remmele). The glass windows and light boxes "have the power to arrest a crowd around a commodity, corralling them in chic bars overlooking the runway as they wait for their call, but also guiding them where to go next" (Fuller, "Welcome" 164). The big bulbous plane sits plump in its hangar — no sound barriers broken here. It reassures us that our vehicle is somewhere there in the network, resting at its STOP before its GO. Peeking through the glass wall and sharing a meal with us, this interpenetrative transparency simultaneously joins and separates two planar dimensions — machinic perfection on one hand, organic growth and death on the other (Rowe and Slutsky; Fuller, "Welcome").Bruce Mau is typical in suggesting that the commanding problem of the twentieth century was speed, represented by the infamous image of a US Navy Hornet fighter breaking the sound barrier in a puff of smoke and cloud. It has worked its way into every aspect of the design experience, manufacturing, computation and transport.But speed masks more than it reveals. The most pressing problem facing designers and citizens alike is growth — from the unsustainable logic of infinite growth in GDP to the relentless application of Moore's Law to the digital networks and devices that define contemporary society in the first world. The shift of emphasis from speed to growth as a time-based event with breaking points and moments of rupture has generated new possibilities. "Growth is nonlinear and unpredictable ... Few of us are ready to admit that growth is constantly shadowed by its constitutive opposite, that is equal partners with death” (Mau 497).If speed in part represents a flight from death (Virilio), growth invokes its biological necessity. In his classic study of the persistence of the pastoral imagination in technological America, The Machine in the Garden, Leo Marx charted the urge to idealize rural environments at the advent of an urban industrialised America. The very idea of "the flight from the city" can be understood as a response to the onslaught of technological society and it's deathly shadow. Against the murderous capacity of technological society stood the pastoral ideal, "incorporated in a powerful metaphor of contradiction — a way of ordering meaning and value that clarifies our situation today" (Marx 4). 5. Windows at 35,000 FeetIf waiting and stillness are active forms of bodily engagement, we need to consider the different layers of motion and anticipation embedded in the apprehension of these luminous black-box windows. In The Virtual Window, Anne Friedberg notes that the Old Norse derivation of the word window “emphasizes the etymological root of the eye, open to the wind. The window aperture provides ventilation for the eye” (103).The virtual windows we are considering here evoke notions of view and shelter, open air and sealed protection, both separation from and connection to the outside. These windows to nowhere allow two distinct visual/spatial dimensions to interface, immediately making the visual field more complex and fragmented. Always simultaneously operating on at least two distinct fields, windows-within-windows provide a specialized mode of spatial and temporal navigation. As Gyorgy Kepes suggested in the 1940s, the transparency of windows "implies more than an optical characteristic; it implies a broader spatial order. Transparency means a simultaneous perception of different spatial locations" (Kepes 77).The first windows in the world were openings in walls, without glass and designed to allow air and light to fill the architectural structure. Shutters were fitted to control air flow, moderate light and to enclose the space completely. It was not until the emergence of glass technologies (especially in Holland, home of plate glass for the display of commercial products) that shielding and protection also allowed for unhindered views (by way of transparent glass). This gives rise to the thesis that windows are part of a longstanding architectural/technological system that moderates the dual functions of transparency and separation. With windows, multi-dimensional planes and temporalities can exist in the same time and space — hence a singular point of experience is layered with many other dimensions. Transparency and luminosity "ceases to be that which is perfectly clear and becomes instead that which is clearly ambiguous" (Rowe and Slutsky 45). The light box air-portals necessitate a constant fluctuation and remediation that is at once multi-planar, transparent and "hard to read". They are informatic.From holes in the wall to power lunch at 35,000 feet, windows shape the manner in which light, information, sights, smells, temperature and so on are modulated in society. "By allowing the outside in and the inside out, [they] enable cosmos and construction to innocently, transparently, converge" (Fuller, "Welcome" 163). Laptop, phone, PDA and light box point to the differential mobilities within a matrix that traverses multiple modes of transparency and separation, rest and flight, stillness and speed.6. Can You Feel It?Increasingly the whole world has come to smell alike: gasoline, detergents, plumbing, and junk foods coalesce into the catholic smog of our age (Illich 47).In these forlorn corners of mobile consumption, the dynamic of circulation simultaneously slows and opens out. The surfaces of inscription implore us to see them at precisely the moment we feel unseen, unguided and off-camera. Can you see it, can you feel it, can you imagine the unimaginable, all available to us on demand? Expectation and anticipation give us something to look forward to, but we're not sure we want what's on offer.Air travel radicalizes the separation of the air traveller from ground at one instance and from the atmosphere at another. Air, light, temperature and smell are all screened out or technologically created by the terminal plant and infrastructure. The closer the traveller moves towards stillness, the greater the engagement with senses that may have been ignored by the primacy of the visual in so much of this circulatory space. Smell, hunger, tiredness, cold and hardness cannot be screened out.In this sense, the airplanes we board are terminal extensions, flying air-conditioned towers or groundscrapers jet-propelled into highways of the air. Floating above the horizon, immersed in a set of logistically ordained trajectories and pressurized bubbles, we look out the window and don't see much at all. Whatever we do see, it's probably on the screen in front of us which disconnects us from one space-time-velocity at the same time that it plugs us into another set of relations. As Koolhaas says, junkspace is "held together not by structure, but by skin, like a bubble" (Koolhaas). In these distended bubbles, the traveler momentarily occupies an uncommon transit space where stillness is privileged and velocity is minimized. The traveler's body itself is "engaged in and enacting a whole kaleidoscope of different everyday practices and forms" during the course of this less-harried navigation (Bissell 282).7. Elevator MusicsThe imaginary wheel of the kaleidoscope spins to reveal a waiting body-double occupying the projected territory of what appears to be a fashionable Miami. She's just beyond our reach, but beside her lies a portal to another dimension of the terminal's vascular system.Elevators and the networks of shafts and vents that house them, are to our buildings like veins and arteries to the body — conduits that permeate and structure the spaces of our lives while still remaining separate from the fixity of the happenings around them (Garfinkel 175). The terminal space contains a number of apparent cul-de-sacs and escape routes. Though there's no background music piped in here, another soundtrack can be heard. The Muzak corporation may douse the interior of the elevator with its own proprietary aural cologne, but at this juncture the soundscape is more "open". This functional shifting of sound from figure to ground encourages peripheral hearing, providing "an illusion of distended time", sonically separated from the continuous hum of "generators, ventilation systems and low-frequency electrical lighting" (Lanza 43).There is another dimension to this acoustic realm: “The mobile ecouteur contracts the flows of information that are supposed to keep bodies usefully and efficiently moving around ... and that turn them into functions of information flows — the speedy courier, the networking executive on a mobile phone, the scanning eyes of the consumer” (Munster 18).An elevator is a grave says an old inspector's maxim, and according to others, a mechanism to cross from one world to another. Even the quintessential near death experience with its movement down a long illuminated tunnel, Garfinkel reminds us, “is not unlike the sensation of movement we experience, or imagine, in a long swift elevator ride” (Garfinkel 191).8. States of SuspensionThe suspended figure on the screen occupies an impossible pose in an impossible space: half falling, half resting, an anti-angel for today's weary air traveller. But it's the same impossible space revealed by the airport and bundled up in the experience of flight. After all, the dimension this figures exists in — witness the amount of activity in his suspension — is almost like a black hole with the surrounding universe collapsing into it. The figure is crammed into the light box uncomfortably like passengers in the plane, and yet occupies a position that does not exist in the Cartesian universe.We return to the glossy language of advertising, its promise of the external world of places and products delivered to us by the image and the network of travel. (Remmele) Here we can go beyond Virilio's vanishing point, that radical reversibility where inside and outside coincide. Since everybody has already reached their destination, for Virilio it has become completely pointless to leave: "the inertia that undermines your corporeity also undermines the GLOBAL and the LOCAL; but also, just as much, the MOBILE and the IMMOBILE” (Virilio 123; emphasis in original).In this clinical corner of stainless steel, glass bricks and exit signs hangs an animated suspension that articulates the convergence of a multitude of differentials in one image. Fallen into the weirdest geometry in the world, it's as if the passenger exists in a non-place free of all traces. Flows and conglomerates follow one another, accumulating in the edges, awaiting their moment to be sent off on another trajectory, occupying so many spatio-temporal registers in a dynamic range of mobility.ReferencesAppleyard, Donald. "Motion, Sequence and the City." The Nature and Art of Motion. Ed. Gyorgy Kepes. New York: George Braziller, 1965. Adey, Peter. "If Mobility Is Everything Then It Is Nothing: Towards a Relational Politics of (Im)mobilities." Mobilities 1.1 (2006): 75–95. Bissell, David. “Animating Suspension: Waiting for Mobilities.” Mobilities 2.2 (2007): 277-298.Bourriaud, Nicolas. Relational Aesthetics. Trans. Simon Pleasance and Fronza Woods. Paris: Les Presses du Reel, 2002. Classen, Constance. “The Deodorized City: Battling Urban Stench in the Nineteenth Century.” Sense of the City: An Alternate Approach to Urbanism. Ed. Mirko Zardini. Baden: Lars Muller Publishers, 2005. 292-322. Friedberg, Anne. The Virtual Window: From Alberti to Microsoft. Cambridge: MIT P, 2006. Fuller, Gillian, and Ross Harley. Aviopolis: A Book about Airports. London: Black Dog Publishing, 2005. Fuller, Gillian. "Welcome to Windows: Motion Aesthetics at the Airport." Ed. Mark Salter. Politics at the Airport. Minnesota: U of Minnesota P, 2008. –––. "Store Forward: Architectures of a Future Tense". Ed. John Urry, Saolo Cwerner, Sven Kesselring. Air Time Spaces: Theory and Method in Aeromobilities Research. London: Routledge, 2008. 63-75.Garfinkel, Susan. “Elevator Stories: Vertical Imagination and the Spaces of Possibility.” Up Down Across: Elevators, Escalators, and Moving Sidewalks. Ed. Alisa Goetz. London: Merrell, 2003. 173-196. Gordon, Alastair. Naked Airport: A Cultural History of the World's Most Revolutionary Structure. New York: Metropolitan, 2004.Illich, Ivan. H2O and the Waters of Forgetfulness: Reflections on the Historicity of Stuff. Dallas: Dallas Institute of Humanities and Culture, 1985. Kepes, Gyorgy. Language of Vision. New York: Dover Publications, 1995 (1944). Koolhass, Rem. "Junkspace." Content. 6 Mar. 2009 ‹http://www.btgjapan.org/catalysts/rem.html›.Lanza, Joseph. "The Sound of Cottage Cheese (Why Background Music Is the Real World Beat!)." Performing Arts Journal 13.3 (Sep. 1991): 42-53. McLuhan, Marshall. “Is It Natural That One Medium Should Appropriate and Exploit Another.” McLuhan: Hot and Cool. Ed. Gerald Emanuel Stearn. Middlesex: Penguin, 1967. 172-182. Marx, Leo. The Machine in the Garden: Technology and the Pastoral Ideal in America. London: Oxford U P, 1964. Mau, Bruce. Life Style. Ed. Kyo Maclear with Bart Testa. London: Phaidon, 2000. Munster, Anna. Materializing New Media: Embodiment in Information Aesthetics. New England: Dartmouth, 2006. Pascoe, David. Airspaces. London: Reaktion, 2001. Pearman, Hugh. Airports: A Century of Architecture. New York: Abrams, 2004. Remmele, Mathias. “An Invitation to Fly: Poster Art in the Service of Civilian Air Travel.” Airworld: Design and Architecture for Air Travel. Ed. Alexander von Vegesack and Jochen Eisenbrand. Weil am Rhein: Vitra Design Museum, 2004. 230-262. Rowe, Colin, and Robert Slutsky. Transparency: Literal and Phenomenal. Perspecta 8 (1963): 45-54. Virilio, Paul. City of Panic. Trans. Julie Rose. Oxford: Berg, 2005.

Depression memes are a widespread phenomenon across all social media platforms. To get your hit of depression memes, you can go to any number of pages on Facebook, the subreddit “2me4meirl”, where the posts that are “too real” for more mainstream subreddits go, but nevertheless counting over one million subscribers or, on Instagram, and find innumerable accounts dedicated to “sad memes”, many with tens to hundreds of thousands of followers. In a recent study, depression memes were found to be responsible for 35 per cent of the content researchers analysed in the “#depressed” hashtag on Instagram (McCosker and Gerrard). As a subculture, it is one that has truly embraced the polyvocality of memes, allowing many voices to speak at once through their lack of fixed meaning (Milner). In depression memes, polyvocality allows the user to identify with any number of anxieties affectively represented by the memes without being authentically tied to them, under the guise of irony. Therefore, depression memes find themselves being used in a myriad of ways that do not refer to a stable structure of meaning. This allows me to problematise their roles as both masks and intimate texts within an ironic meme culture.Drawing on traditional readings of irony such as Wayne C. Booth but also contemporary approaches to authenticity, mask cultures and meme culture (de Zeeuw; Tuters), this article situates depression memes specifically within neoliberal regimes of feeling, manifested both in online practices of authenticity and the subject of value (Skeggs and Yuill) and in discourses of resilience and accountability surrounding mental health (Fullagar et al.; James; McCosker). It argues that an internet depression culture based on the principles of dissimulation serves both the purpose of protection from recuperation by dominant narratives but paradoxically creates an ambiguity that generates that risk. In this way, I speak to current anxieties surrounding memes, including ambiguity, irony, and identity formation.Internet Depression Culture Intrinsic to their nature as memes, depression memes can be found in a variety of spaces, formats and platforms. The ones below (Figure 1) circulate on mainstream social media platforms like Facebook and Instagram through accounts dedicated to “sadposting” or the sharing of mental illness memes. They refer to overwhelming feelings of anxiety, a lack of will to live and a desire to recover. In their recent study on hashtagging depression on Instagram, McCosker and Gerrard found memes to be responsible for a wide range of content in the “depressed” hashtag on the platform. They argue that the use of the hashtag “depressed” is primarily as a “memetic device, often with a sense of irreverence, subversiveness and pathos, but in an effort to use the connective power of the popular tag to gain attention and Likes” (McCosker & Gerrard 9). Intimacy and memes as identity performance are therefore intimately intertwined, espousing the memetic logic that there is “safety in relatability” (Ask and Abidin 844), which is dependent on “connecting to common anxieties in a pleasurable, noncompromising way” (Kanai 228).Figure 1. Depression Memes. Sources, from left to right. Top row: <https://www.instagram.com/p/Bl5p88Tg8Cw/>; <https://www.facebook.com/mentallythrillmemes/>; <https://twitter.com/animatedtext>. Bottom row: <https://lovenotlogic.tumblr.com/post/168640369069>; <https://disasterlesbian.com/post/158174792381>; <https://www.facebook.com/mentallythrillmemes>.Indeed, meme culture depends both on the notion that certain forms of content can be relied on to “gain attention and likes” and increase a user’s social capital, but can also be interpreted as intimate and private forms of expression. The popularity of depression memes is a testament to this principle, but at the heart of this culture is a usage of irony that remains ambiguous and undefined. Whether these texts can be found to reflect genuine feelings of relatability is complex, but ultimately irrelevant. As Burton remarks on the culture of Kek, “sociologically speaking”, the sharing of these memes still constitutes a cultural engagement. Therefore, what I refer to as internet depression culture must be understood not as an attitude of self-presentation, but an inter-affective network that relies on precarious and overwhelmingly ironic objects whose authenticities as intimate texts are dependent on volatile and unstable structures of meaning.Wayne C. Booth’s A Rhetoric of Irony tells us that for an expression to be understood as ironic, their meaning needs to be reconstructed by the reader and intended by the author. The reader must therefore draw from the cultural and historical context of the expression to reconstruct covert meaning that the author intended. The inferential process draws from the context of the expression to give meaning to irony. Online, the cultural context in which depression memes have risen to popularity is precisely that which gives them their reason for being. To understand this, we need to realise that, for the last decade, the symptoms that depression memes cultivate have been lying dormant under the tyranny of happiness era of social media (Freitas). I tie this notion to the doctrine of authenticity behind the identity imperative of social media platforms like Facebook (Van Dijck), and contrast it to the forms of subjectivisation anonymous or pseudonym-based cultures on platforms like 4chan embody. Within this dialectic, memes have arisen as the logic of the Internet, and irony as their social contract (Tuters; Burton). New forms of sociality that manifest within this culture are necessarily ambiguous and risk-filled ones, and need to be explored.From the Happiness Effect to a New Sensibility In The Happiness Effect, Donna Freitas investigated social media usage in young adults by surveying over 800 college students about the relationship between social media and their emotional well-being. Her results allowed her to coin the term “happiness effect”, when: “young people feel so pressured to post happy things on social media”. She writes: “most of what everyone sees on social media from their peers are happy things; as a result, they often feel inferior because they aren’t actually happy all of the time” (14). Feelings of inadequacy result when users interpret what other users post to be authentically felt, despite themselves feeling “pressured” to post a certain type of content, one they do not resonate with but fabricate for the purpose of posting. Indeed, the authenticity imperative behind identity-based social media is what defines our relationship to it.Identity-based platforms like Facebook rely on allowing the user to create an identity on their site, but demand from users that the platform be used for “‘expressing who they are’, implying that users do not “perform” their identity on Facebook; they are the selves they portray on Facebook” (Kant 34). As always, this must be situated within the commercial logic behind the seemingly “free” and “public” service the platform offers. Multiplicity and having “multiple identities” (van Dijck) does not cooperate with Facebook’s platform logic because it does not produce valuable legible data which conforms to “normative, regulatory and commercially viable frameworks” (Kant 35). As Skeggs and Yuill note, the contemporary neo-liberal imperative to perform and authorize one’s value in public is more likely to produce a curated persona rather than the “authentic” self demanded by Facebook (380). The happiness effect manifests this. Despite not being legitimate, an identity must be curated to fit in with the other performed personas on the platforms, which are taken as authentic.To many, the irony that makes depression memes such as those in Figure 1 work is in their subversion of the happiness effect and the authenticity imperative. The meaning to be reconstructed in a depression meme consists in peeling back the layer that demands from us to act as the best, happiest, version of ourselves online. Simply put, it unmasks the actual authentic self behind the curated one. Therefore, the self made visible by partaking, sharing or liking depression memes is not necessarily the best one, but, fundamentally, it is a more authentic one. Indeed, it seemed that, in the early phase of its life, users were enamoured with depression memes because it released them from the burden of identity management. What emerged in this phase of the depression memes movement was the perception of a new sensibility based on a more authentic intimacy than had ever been associated with memes. Press coverage of the topic continued to celebrate the emancipatory potential of depression memes, citing the movement as reflective of a new, more sentimental public made possible by the internet (Roffman).As has been argued before by McCosker, the forms of digital intimacy that render personalised distress visible are ones entrenched in visibility and authenticity, pillars of the face culture of Facebook. Comments on memes or reviews of depression meme pages continuously cited relatability and visibility as their reason for identification with the page. Users felt that these memes allowed them to be seen online, with their mental illness, and feel intimately connected to other viewers; “it feels good to know that other people go through the same thing as me” (Figure 2). Though it is a form of public performance, the intimacy generated here feels inherently private because it relies on unravelling certain structures of meaning. This is a skill that, users imply, can only be attained by having experienced the feelings evoked in the depression memes. In these comments, intimacy is a form of identity performance, and a discourse of accountability underpins one of authenticity. Irony, though present, is quickly reconstructed and explained away into more stable structures of meaning through these discourses.Figure 2. Reviewers of “Mentally thrill memes” on Facebook. Irony and Masked PracticesHowever, the tension produced within the user’s psyche by years of subjectivisation and the “curated self” has taken its toll. The social contract of irony in digital culture has come just in time to recuperate authenticity from the burden of management it was placing on its subjects. I’ve spoken to the use of irony as generative of new forms on intimacy, but here I turn to how irony can simultaneously be adopted for the purposes of evading that stifling regime of the self and doctrine of authenticity. In terms of platform moderation in the case of sensitive or problematic issues, subversion through irony allows an alternative discursive economy to exist by evading censorship. When it rejects models through which the self can be turned into data by turning its back on commensurable ways of displaying public emotion, it is a commentary on the authenticity culture of social media. In this, it reflects practices of dissimulation.Ideologically, anonymity and multiplicity in the “deep vernacular web” stands in antithesis to the doctrine of authenticity. Anonymised imageboard cultures such as those found on 4chan have moulded themselves as the Other to the straightforward intentionality of profile based social media (de Zeeuw, Between). Their truth is in their collectivistic rejection of authenticity, constituting an anti-personal, faceless and authorless mass, infamous for their subversion through trolling. They obey an Internet logic that can be summarised as follows; “the internet is not serious business, and anyone who thinks otherwise should be corrected and is, essentially, undeserving of pity” (Tuters). In this, the logic of dissimulation operates as their reason for being. Dissimulation entails a play with identity, one not interested in stability but more in the constant deferral of meaning and self. This negotiation is based on evading the notion of the self in order to gain further freedom through collective play. For these anonymised and anti-personal cultures, the value of dissimulation is to mediate their relationship to society at large.Indeed, as Daniel de Zeeuw notes, mask cultures’ play with identity is not simply a reactionary movement against the subjectivisation of social media but can be understood as part of a rich carnivalesque tradition which revels in the potential of the mask. In this case, the collective culture gathers around the picture of the mask as a symbol of the “dialectic between the masked mass and the authorial, personal self” (de Zeeuw, Immunity 276). The notion that a more authentic, truer self lies under a series of masks is also one taken up by psychoanalysis and various schools of thought. In this way, irony has often been compared to “peering behind a mask” (Booth 33), leading to its valorisation as an act of dissimulation by these cultures. Taking as gospel that “there is no true Self, only an endless series of interchangeable masks” (Lovink 40), for these cultures the mask “is the work of art that best exemplifies the detachment achieved through irony” (Trilling 120). However, irony “risks disaster more aggressively than any other device” (Booth 41). The potential that mask cultures value irony for also creates risk because it trains readers to expect something but never tells us when to stop interpreting its irony. The emancipatory capacity of irony then, is a tension-filled one.Ironic Depression MemesDepression memes I addressed before peel back the layers of the happiness effect and social media cultures by legitimising themselves through authenticity. I turn now to ironic memes about depression memes and their tie to the principles of dissimulation as influenced by mask cultures. Meme culture’s existence across social media platforms, and structural nature as logic of ironic undermining means that, once depression memes were praised in earnest as the new sensibility of the Internet, the next step for the depression memes movement was to be deeply disingenuous and self-aware about the promise of authenticity they were offering. Memes about depression memes are meta memes that are self-reflective about the depression meme movement, referencing using memes to combat loneliness, sadness or overthinking in an ironic way.Figure 3. Ironic memes referencing the use of depression humour. Sources, from left to right. Top row: <https://www.instagram.com/p/B3aH9cmIr1L>; <https://www.reddit.com/r/MemeEconomy/comments/8wotcn/invest/>; <https://jennyhoelzer-deactivated2016120.tumblr.com/post/153443805168/>. Bottom row: <https://twitter.com/animatedtext>; <https://www.instagram.com/p/B0ZsQAMHiAU>; <https://www.reddit.com/r/2meirl4meirl/comments/8se3l5/2meirl4meirl/>.Ironic depression memes can be found on the same platforms other depression memes circulate in, existing as a parallel discourse to, and meta-commentary on, the celebratory, cathartic engagement in depression memes as seen on Facebook. They acknowledge the use of the mask, drawing attention to the divide between one’s chosen digital self-presentation and offline identity. Through this, they re-edify boundaries that depression memes were praised as obliterating. In the ironic memes above, presenting yourself as depressed online is okay, but actually being depressed is no laughing matter (actual suicide = no), and therefore should not be memed about. Memes are a mask that depressed millennials offer to other depressed millennials, to be used against depression, sadness, and overthinking, but mostly to hide that, though the memes are “ironic”, the depression is still very much “chronic”.Ironic depression memes shed the burden of cultures of authenticity and accountability when they disavow the notion of a fixed self. The use of the meme as a mask evokes a privacy and anonymity found within irony that rejects the contemporary mediation of mental ill health through a set of discourses based in neoliberal personhood (Fullagar et al.; McCosker). The bonds being made here are supposedly private, revelling in the facelessness of collective irony, but both weak and risky. The value of the meme is defined by the acknowledgement of the usage of the mask to hide emotions still too taboo or painful to publicly gesture too. Though depression memes undermine that authenticity and accountability should be the pillars of mental health discourse, their use of irony creates unstable ground for a new structure of feeling to emanate from these memes. Irony is about expecting something to mean something else, therefore valuing one set of meaning over another (Booth 33). If the new set of meaning fundamentally cannot be identified, which is key in dissimulation and mask-cultural practices, then this new culture opens up ambiguity which can be recuperated by dominant narratives. In this way, I argue that dissimulation serves the purposes of protection from the mediation of depression through individualising discourse, but paradoxically creates an opening to do so. Wholesome Memes and Resilience I turn now to how “wholesome memes” provide non-ironic commentary on the irony of memes. I argue that, even in a logic removed from the authenticity imperative of face media, and therefore from a notion of identity and profile based interaction, narratives of accountability still recuperate the subversion of depression memes. In the case of depression memes, discourses of resilience and overcoming are promoted as the “correcting” set of values, preferential to the ambiguous multiplicity of dissimulation. Figure 4. “Fixedyourmeme” wholesome memes making use of editing and re-writing.The “wholesome memes” movement aims to edit and correct depression memes, such as examples from a Tumblr page entitled “fixed your meme”. These memes take on popular meme formats that are either neutral and open to remixing, or are known in popular meme culture to be predetermined. On the right, “My memes are ironic, my depression is [chronic]” is a popular motif whose grammar is predetermined (seen in Figure 3) but also an easily deciphered subtext, even if written over, if one is well-versed in meme culture and the mechanisms through which it replicates itself. The explicit editing and re-writing, crossing out the “toxic” message to make apparent the re-writing of the narrative, is purposeful here. The relation to resilience is built as much inside and outside the text. It serves to exemplify the overcoming of the mental illness and the move towards a radical attitude of self-love and recovery. Wholesomeness, positivity, wellness and self-care are the keywords. In these texts, the wellness industry serves as a counter-narrative, preaching a discourse that dictates: “it is within an individual’s power and even a moral obligation to be happy” (Garde-Hansenand Gorton 104).When I refer to resilience, I refer to a specific kind of discourse as coined by Robin James that follows the logic of acknowledging and overcoming damage in order to be “rewarded with increased human capital, status, and other forms of recognition and recompense” (19). Overcoming brings added human capital because it demonstrates resilience which boosts society’s resilience. When depression memes render embodied suffering visible and publicly intelligible, they perform resilience through a therapeutic narrative. In these types of narratives, we see what Fullagar et al. describe as “affective work and action which is required in efforts to be ‘happy’ and achieve ‘normality’” that “commonly evokes a particular form of introspection and surveillance” (10). In this way, wholesome memes can be thought of as an affective assemblage that recuperates narratives of subversion as embodied by ironic memes and mask cultures, thereby “re-ordering flows through capitalist relations that exploit the connection between desire and lack” (Holland 68). Conclusion Internet depression culture operates at the crux of meme culture and neoliberal subjectivisation by both enacting and overcoming mental health regimes of care through irony. The irony within depression memes to be reconstructed is dependent on two structures of meaning. The first is the one within which the memes are being read and interpreted, namely an online meme culture and its collective irony imperative, which I argue is also a parallel discursive area of the neoliberal subjectivisation of value on social media. The second is a product of years of increasing individualisation of mental health discourse, one that emphasises resilience and overcoming in line with values of authenticity and accountability. In different Internet cultures, the intersection of these two contexts manifests differently. Online, irony and polysemy are both tools of subversion and privacy. However, cultures of play are constantly challenged by social media and places where dominant narratives are ones of authenticity and accountability. Depression memes demonstrate that irony can be mobilised into authentic flows of intimacy in the context of certain dominant discourses.Figure 5. “I thought it was just memes”. Source: <https://thisiselliz.com/post/152882025410>.ReferencesAsk, Kristine, and Crystal Abidin. “My Life Is a Mess: Self-Deprecating Relatability and Collective Identities in the Memification of Student Issues.” Information, Communication & Society 21.6 (2018): 834-850.Booth, Wayne C. A Rhetoric of Irony. 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