ANALYSIS OF HEAT AND MASS TRANSFER ON THE PERISTALTIC MOVEMENT OF CARREAU NANOFLUIDS

In this investigation, we have analyzed the peristaltic movement of MHD Carreau nanofluids in a curved channel by taking the thermophoresis and Brownian motion effects into account. The governing equations of the fluid flow like the equations of continuity, momentum, temperature and concentration are modulated and abridged by using the theory of lubrication approximations. A regular perturbation is used to solve the simplified coupled nonlinear differential equations. The changes of various fluid parameters on axial velocity, temperature and concentrations are carefully calculated, and the graphical results are analyzed. According to the result of this study, it is determined that the resulting velocity of nanofluid decreases significantly when the applied radial magnetic field is strengthened. In addition, the curvature parameter has a significant impact on the concentration function, and when the curvature of the channel is increased, the absolute value of the nanoparticle concentration distribution diminishes.

Chemical component depositions in the microbial mats and travertine in the Khoito-Gol thermal spring (Eastern Sayan)

The results of studies of the chemical composition of water, travertine, and microbial mats in the Khoito-Gol mineral spring (Eastern Sayan) are presented. It was shown that the formation of mineral deposits, travertine, and microbial mat is connected with the active functioning of microorganisms and geological and geodynamic conditions. It has been revealed that the diversity of cyanobacterial and sulfur microbial mats increases as the distance from the springs of the thermal water grows. Microbial mats are hardened with carbonates being converted into solid travertine crusts that are built upon the top of older structures to form multi-meter domes. The concentration function of the microbial mats and thermal water showed higher coefficients of accumulation of nickel and beryllium.

Simulation of concentration of an admixture in the multiphase layer with random spherical inclusions

The diffusion of an admixture substance in a multiphase layer with randomly disposed spherical inclusions was investigated. The solution of the initial contact-boundary value problem is obtained in the form of the integral Neumann series. Computer simulation was performed based on the obtained calculation formula. Main regularities of the distributions of the averaged admixture concentration in the layer depending on the values of the diffusion coefficients, density and volume fractions of inclusions were established. The influence of the number of phases of the porous body on the diffusion processes in a multiphase layer with a uniform distribution of spherical inclusions was determined. The dependence of the increase of the averaged concentration function on the characteristic radii of spherical inclusions was analyzed, in particular, it is shown that the behavior of this function does not depend on the ratios of the reduced diffusion coefficients.

POS1123 DISORDERS OF URODYNAMICS AND PARENCHYMA CONCENTRATION FUNCTION IN PATIENTS WITH ARTERIAL HYPERTENSION AND GOUT

Background:The combination of arterial hypertension and gout increases the risk of developing chronic kidney disease in patients.Objectives:To assess urodynamics and concentration function of the renal parenchyma in patients with arterial hypertension and gout.Methods:We examined 87 patients with arterial hypertension and gout. 83% of the patients were men with a mean age of 55.4±12.3 years. Grade I arterial hypertension was detected in 43.7% of patients, grade II was in 36.9% and grade III was in 19.3%. The duration of arterial hypertension was 8 [4; 11] years. All the patients had chronic gouty arthritis. 30% of the patients had tophi. The duration of gout was 7 [2; 10] years. Markers of renal lesions, urine sediment and GFR calculation were assessed in all the patients. All the patients were performed a modern systems analysis of nephrological conditions based on comprehensive renoscintigraphy (SENS-CRS) which allows to make an in-depth differential analysis of the renal parenchyma and thus reveals abnormalities in the upper and lower urinary tract function with a minimum of radiation exposure of 0.6 mSv per patient.Results:Using the standard method of GFR calculation with CKD-EPI formula we found that 10 patients (11.3%) had no signs of CKD (GFR over 90 ml/min); 56 patients (64.5%) had I-II stage of CKD (GFR over 60 ml/min) 21 patients (24.2%) had III-IV stage of CKD (GFR less than 60 ml/min).The patients were divided into two groups for a differentiated assessment of urodynamics. Group I consisted of 66 patients with a GFR of more than 60 ml/min and Group II consisted of 21 patients with a GFR of less than 60 ml/min. The comparison of the two groups revealed abnormalities in urodynamics. In Group 1 arterial blood flow in the parenchyma (A 14.5±6.8 sec) was slowing down against the background of normal venous outflow (V 17.8%±9.2%). Concentration function of the kidneys was sufficient (Gren 17.6±5.2 o.e.). The total excretion rate of labeled urine from the two kidneys decreased to D = 56.5% ± 16.1% during its transition from the cortical to the cerebral layer of the renal parenchyma. The indixes of the relative urinary stasis in the renal calyx-pelvis system exceeded the standard ones on average by 2 times (KC 4.8 ± 3.2; KP 7.0 ± 4.2), which indicated stagnant disorders in the kidneys, hidden from conventional diagnostic methods. The patients in Group II had those abnormalities even more expressed (A 12.4±4.5 sec, V 12.8%±9.4%, D 51.9%±15.4%, KC 5.0±3.3; KP 9.5±5.2).16 patients under follow-up who had arterial hypertension with serum creatinine levels greater than 125 μmol/l were classified as a subgroup of patients at an increased risk of developing high stages of CKD. Stages I-II were previously diagnosed in the 16 patients according to the CKD-EPI formula and stage III CKD with a high risk of progression to stage IV CKD was diagnosed in one patient.A comparative analysis of the SENS-CRS data of the patients with arterial hypertension was performed between the above-mentioned 16 patients and the remaining 71 patients. The nonparametric Mann-Whitney method was used (p<0.05) for the purpose. The method was established only by the indicator D (%) of the rate of elimination of the radiopharmaceutical from the renal parenchyma. However, no significant differences were found either for the calculated GFR values, or for all other parameters of complex renoscintigraphyConclusion:After the gout diagnosis is made and confirmed by screening, it is important that patients with gout and hypertension should be included in the nephrologic monitoring system to control risk factors associated with the development or aggravation of CKD.The renocortical parameter D (%), used in the SENS-CRS technology, is a prognostically important preclinical marker of intrarenal congestion in the latent development of serious morphofunctional disorders in the renal parenchyma leading to the development of CKD or the aggravation of an existing stage of CKD.Disclosure of Interests:None declared.

Mengkaji Tindakbalas Nanozarah Silika Dioksida (SiO2) dengan Lisozim Dalam Larutan Penimbal

Kajian ini dilakukan untuk mengkaji kesan tindak balas nanozarah polimer, silika dioksida (SiO2) dengan protein, (Lisozim) dalam larutan penimbal. Tujuan kajian adalah untuk menentukan kestabilan serta kesan interaksi nanozarah SiO2 dengan lisozim sebagai fungsi kepekatan yang dikaji dengan menggunakan spektroskopi ultralembahyung-cahaya nampak (U.V.-Visible). Kaedah yang digunakan dalam kajian ini iaitu kaedah penambahan (serbuk), kaedah cecair homogen, kaedah perpisahan fasa dan kaedah penyerapan (tindakbalas). Hasil kajian mendapati penjerapan lisozim yang bercas positif (hidrofobik) terhadap permukaan nanozarah SiO2 yang bercas negatif (hidrofilik) adalah sesuai pada pH 7.8. Bagi perbezaan nisbah berat SiO2: Lisozim sama ada berat lisozim atau SiO2 tetap, puncak yang diperolehi adalah sekitar 280nm. Kadar penjerapan lisozim bergantung kepada masa tindak balas dan juga faktor pembauran. Saiz nanozarah SiO2 yang kecil menyebabkan ianya mempunyai luas permukaan yang besar berbanding isipadu dan membolehkan lisozim dijerap pada permukaannya tanpa sebarang halangan. Oleh yang demikian dapat disimpulkan bahawa, wujud kestabilan antara lisozim dan SiO2 yang membolehkan penjerapan berlaku dan terbentuknya gumpalan akibat daripada kesan tindak balas. This study was conducted to study the interaction effect of polymer nanoparticles, silica dioxide (SiO2) with protein, (Lysozyme) in buffer solution. The purpose of the study was to determine the stability and the effect of the interaction of SiO2 nanoparticles with lysozyme as a concentration function studied using ultraviolet-visible (U.V.-visible) spectroscopy. The methods used in this study are the addition method (powder), homogeneous liquid method, phase separation method and absorption method (interaction). The results of the study found that the adsorption of positively charged (hydrophobic) lysozyme to the surface of negatively charged SiO2 nanoparticles (hydrophilic) is suitable at pH 7.8. For the difference weight ratio in SiO2: Lysozyme either lysozyme weight or fixed SiO2, the peak obtained is around 280nm. The rate of absorption of lysozyme depends on the reaction time as well as the diffusion factor. The small size of the SiO2 nanoparticles causes it to have a large surface area compared to the volume and allows lysozymes to be adsorbed on its surface without any obstruction. Therefore, it can be concluded that there is a stability between lysozyme and SiO2 that allows adsorption to occur and the formation of agglomeration as a result of the interaction effect.

Calculation of displacements and internal forces of anchored retaining piles

Pile-anchor retaining structures are widely used in excavation engineering. The evaluation of lateral displacements, the internal forces of piles are extremely important for the performance of the structure. Most of the existing methods are empirical, semiempirical or FEM methods, while analytic calculation methods for this evaluation are rare. This paper presents an analytic method to calculate the displacements and internal forces of anchored retaining piles based on the existing design code. In the calculation method, the singular function is applied to evaluate the effect of segmented loading on the deflection of a beam with a nonuniform cross section. The load concentration function, expressed by the singular function, can describe the segmented load and be integrated without a complicated procedure for determining the integral constants. The method is applied to a structure in Wenzhou, China, and the calculation results are compared to the field measurement results. This method is only valid for pre-failure predictions.

Localization and elimination of glare in images of model ice surface

Изображения, получаемые при проведении экспериментов в ледовом бассейне, как правило, содержат многочисленные блики от средств искусственного освещения и естественных источников света. Вследствие зернистой структуры моделированного льда, в рамках одного блика яркие пиксели чередуются с более темными. Такие дефекты изображений препятствуют их автоматическому распознаванию. В статье предложены способы локализации данных дефектов и алгоритм их исключения с восстановлением изображения. Метод локализации замещаемой области основан на использовании функции концентрации пикселей с высокими значениями интенсивности. Алгоритм восстановления изображения основан на итеративном применении методов интерполяции и анизотропной диффузии. Эффективность предложенного способа продемонстрирована на примере восстановления изображений поверхности моделированного льда, приготовленного по технологии Fine Grain в ледовом бассейне Крыловского государственного научного центра (Санкт-Петербург). Images obtained during experiments in an ice tank as a rule contain a lot of glare from artificial lighting and photo equipment. Due to the grainy structure of model ice, bright pixels alternate with darker ones. Therefore, such defects prevent automatic recognition of images. The article suggests the method for localization of light spots on the surface of model ice as well as the algorithm for their elimination and image restoration. The method of area replacement is based on the use of high intensity pixel concentration function and delta concentration function. The image reconstruction algorithm is based on iterative application of interpolation and anisotropic diffusion methods to the part of an image with localized light spot. The effectiveness of the proposed method is demonstrated by the example of restoring images of the surface of simulated ice prepared in accordance with the Fine Grain technology in the ice tank of the Krylov State Research Centre (Saint Petersburg).