scholarly journals Method for Pipeline Section Retrieval for Overhaul with Complete Replacement

2020 ◽  
Vol 459 ◽  
pp. 022028
Author(s):  
A M Akhmedov ◽  
S G Abramyan
Keyword(s):  
Complete Replacement ◽  
Pipeline Section

Development of the mathematical model for assessing the optimal measurement step when surveying the depth of the underground pipeline from the ground

2020 ◽  
Vol 10 (4) ◽  
pp. 364-371
Author(s):  
Ruslan V. Aginey ◽  
◽  
Rustem R. Islamov ◽  
Alexey A. Firstov ◽  
Elmira A. Mamedova ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Survey Data ◽  
Ground Surface ◽  
Maximum Error ◽  
Large Error ◽  
Bending Stress ◽  
Buried Pipeline ◽  
Optimal Measurement ◽  
Pipeline Section ◽  
Bending Stresses

Existing methods for estimating the bending stresses of buried pipeline section based on the survey data for the depth of the axis of the pipeline from the ground surface are characterized by a large error between the real values of the bending stress and the values of the bending stress obtained from the calculation results based on the survey data. The purpose of this study is to improve the methodology for calculating the bending stresses of buried pipeline section based on the results of determining the depth of the axis of the pipeline from the ground surface, taking into account the design features of the pipeline and the used search equipment. Mathematical models are proposed that allow for the set value of the maximum error in determining bending stresses for a particular pipeline to choose the optimal measurement step before the survey, which will allow to reduce the error. Explanations are given on the choice of the maximum step of the study based on the strength characteristics of the pipeline. A calculation is provided that confirms the adequacy of the developed mathematical models and the possibility of their application in practice.

Fabrication of poly (1, 8-octanediol-co-Pluronic F127 citrate)/chitin nanofibril/bioactive glass (POFC/ChiNF/BG) porous scaffold via directional-freeze-casting

2020 ◽  
Vol 40 (7) ◽  
pp. 591-599
Author(s):  
Yaling Tian ◽  
Kai Liang ◽  
Yali Ji
Keyword(s):  
Bioactive Glass ◽  
Porous Structure ◽  
Pore Structure ◽  
Porous Scaffold ◽  
Pluronic F127 ◽  
Porous Scaffolds ◽  
Freeze Casting ◽  
Promising Candidate ◽  
Complete Replacement

AbstractThe citrate-based thermoset elastomer is a promising candidate for bone scaffold material, but the harsh curing condition made it difficult to fabricate porous structure. Recently, poly (1, 8-octanediol-co-Pluronic F127 citrate) (POFC) porous scaffold was creatively fabricated by chitin nanofibrils (ChiNFs) supported emulsion-freeze-casting. Thanks to the supporting role of ChiNFs, the lamellar pore structure formed by directional freeze-drying was maintained during the subsequent thermocuring. Herein, bioactive glass (BG) was introduced into the POFC porous scaffolds to improve bioactivity. It was found the complete replacement of ChiNF particles with BG particles could not form a stable porous structure; however, existing at least 15 wt% ChiNF could ensure the formation of lamellar pore, and the interlamellar distance increased with BG ratios. Thus, the BG granules did not contribute to the formation of pore structure like ChiNFs, however, they surely endowed the scaffolds with enhanced mechanical properties, improved osteogenesis bioactivity, better cytocompatibility as well as quick degradation rate. Reasonably adjusting BG ratios could balance the requirements of porous structure and bioactivity.

scholarly journals Effects of complete replacement of corn flour with sorghum flour in dairy cows fed Parmigiano Reggiano dry hay-based ration

2021 ◽  
Vol 20 (1) ◽  
pp. 826-833
Author(s):  
Giovanni Buonaiuto ◽  
Alberto Palmonari ◽  
Francesca Ghiaccio ◽  
Giulio Visentin ◽  
Damiano Cavallini ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Corn Flour ◽  
Complete Replacement ◽  
Sorghum Flour ◽  
Parmigiano Reggiano

scholarly journals Regulation of mdr2 P-glycoprotein expression by bile salts

1997 ◽  
Vol 321 (2) ◽  
pp. 389-395 ◽  
Author(s):  
Charles M. G. FRIJTERS ◽  
Roelof OTTENHOFF ◽  
Michel J. A. van WIJLAND ◽  
Carin M. J. van NIEUWKERK ◽  
Albert K. GROEN ◽  
...  
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Control Diet ◽  
Mrna Level ◽  
Northern Blotting ◽  
Mrna Levels ◽  
Male Mice ◽  
Complete Replacement ◽  
P Glycoprotein ◽  
Mrna Content

The phosphatidyl translocating activity of the mdr2 P-glycoprotein (Pgp) in the canalicular membrane of the mouse hepatocyte is a rate-controlling step in the biliary secretion of phospholipid. Since bile salts also regulate the secretion of biliary lipids, we investigated the influence of the type of bile salt in the circulation on mdr2 Pgp expression and activity. Male mice were fed a purified diet to which either 0.1% (w/w) cholate or 0.5% (w/w) ursodeoxycholate was added. This led to a near-complete replacement of the endogenous bile salt pool (mainly tauromuricholate) by taurocholate or tauroursodeoxycholate respectively. The phospholipid secretion capacity was then determined by infusion of increasing amounts of tauroursodeoxycholate. Cholate feeding resulted in a 55% increase in maximal phospholipid secretion compared with that in mice on the control diet. Northern blotting revealed that cholate feeding increased mdr2 Pgp mRNA levels by 42%. Feeding with ursodeoxycholate did not influence the maximum rate of phospholipid output or the mdr2 mRNA content. Female mice had a higher basal mdr2 Pgp mRNA level than male mice, and this was also correlated with a higher phospholipid secretion capacity. This could be explained by the 4-fold higher basal cholate content in the bile of female compared with male mice. Our results suggest that the type of bile salts in the circulation influences the expression of the mdr2 gene.

scholarly journals Surgical Outcome of Chronic Subdural Haematoma: An Analysis of 300 Cases

2016 ◽  
Vol 24 (2) ◽  
pp. 126-131
Author(s):  
Sukriti Das ◽  
Asit Chandra Sarkar ◽  
Md Rafiqul Islam ◽  
Md Manirul Islam
Keyword(s):  
Normal Saline ◽  
Surgical Outcome ◽  
Subdural Haematoma ◽  
Subdural Space ◽  
Acute Subdural Haematoma ◽  
Related Factors ◽  
College Hospital ◽  
Complete Replacement ◽  
Poor General Health ◽  
Medical College

Chronic Subdural Heamatoma (CSDH) is defined as collection of blood in the brain’s surface, subdural space between dura and arachnoid. It is one of the most common clinical entities in daily neurosurgical practice among the elders, several weeks after the head injury. CSDH doesn’t always produce symptoms but when it does, it generally requires surgical treatment. The diagnosis and treatment are well established, but the cause of recurrence, complications and related factors are not completely understood. This study evaluated the clinical features, radiological findings and surgical results in a large series of patients treated at the Neurosurgery department of Dhaka Medical College Hospital. 300 consecutive patients (250 men and 50 women) age ranging from 30-85 years, GCS 5-15, volume of blood >25cc, symptomatic with CSDH were treated by one or two burr hole craniostomies. Haematoma cavity was irrigated with normal saline and closed system subdural drainage was continued for 1-2 days from January 2012 to December 2015. The clinical outcome was measure on 1st, 3rd, 5th and 7th POD using GCS scoring and GOS after 4 and 8 weeks of operations. Most patients 94%(282) had good recovery (GOS 5,4,3), 4%(12) showed no changes (GOS 2) and 2%(6) worsened (GOS 1). Recurrence of haematoma was recognized in 5%(15) patients 1-8 weeks after the first operation. 4%(12) patients suffered post operative complications of which 1.33%(4)patients were acute subdural haematoma caused by incomplete haemostasis of the scalp wound, 1.33%(4)patients were tension pneumocephalus and remaining due to hypertension, use of anticoagulants, poor general health and medical problems. Careful haemostasis and complete replacement of subdural haematoma with normal saline to prevent influx of air into the subdural space will further improve the surgical outcome for patients with CSDH.J Dhaka Medical College, Vol. 24, No.2, October, 2015, Page 126-131

Elastic-plastic bending of the pipeline under combined loading

2021 ◽  
pp. 372-377
Author(s):  
Виктор Миронович Варшицкий ◽  
Евгений Павлович Студёнов ◽  
Олег Александрович Козырев ◽  
Эльдар Намикович Фигаров
Keyword(s):  
Internal Pressure ◽  
Limit State ◽  
Bending Moment ◽  
Axial Direction ◽  
Longitudinal Force ◽  
Combined Loading ◽  
Dimensional Problem ◽  
Elastic Plastic ◽  
Pipeline Section ◽  
Thin Walled Pipe

Рассмотрена задача упругопластического деформирования тонкостенной трубы при комбинированном нагружении изгибающим моментом, осевой силой и внутренним давлением. Решение задачи осуществлено по разработанной методике с помощью математического пакета Matcad численным методом, основанным на деформационной теории пластичности и безмоментной теории оболочек. Для упрощения решения предложено сведение двумерной задачи к одномерной задаче о деформировании балки, материал которой имеет различные диаграммы деформирования при сжатии и растяжении в осевом направлении. Проведено сравнение с результатами численного решения двумерной задачи методом конечных элементов в упругопластической постановке. Результаты расчета по инженерной методике совпадают с точным решением с точностью, необходимой для практического применения. Полученные результаты упругопластического решения для изгибающего момента в сечении трубопровода при комбинированном нагружении позволяют уточнить известное критериальное соотношение прочности сечения трубопровода с кольцевым дефектом в сторону снижения перебраковки. Применение разработанной методики позволяет ранжировать участки трубопровода с непроектным изгибом по степени близости к предельному состоянию при комбинированном нагружении изгибающим моментом, продольным усилием и внутренним давлением. The problem of elastic plastic deformation of a thin-walled pipe under co-binned loading by bending moment, axial force and internal pressure is considered. The problem is solved by the developed method using the Matcad mathematical package by a numerical method based on the deformation theory of plasticity and the momentless theory of shells. To simplify the solution of the problem, it is proposed to reduce a twodimensional problem to a one-dimensional problem about beam deformation, the material of which has different deformation diagrams under compression and tension in the axial direction. Comparison with the results of numerical solution of the two-dimensional problem with the finite element method in the elastic plastic formulation is carried out. The obtained results of the elastic-plastic solution for the bending moment in the pipeline section under combined loading make it possible to clarify criterion ratio of the strength of the pipeline section with an annular defect in the direction of reducing the rejection. Application of the developed approach allows to rank pipeline sections with non-design bending in the steppe close to the limit state under combined loading of the pipeline with bending moment, longitudinal force and internal pressure.

Pseudo-morphogenesis in the shells of the Silurian brachiopods

2021 ◽  
Vol 3 ◽  
pp. 49-55
Author(s):  
V.I. Katkova ◽  
◽  
T.M. Beznosova ◽  
V.N. Filippov
Keyword(s):  
Structural Organization ◽  
Mineral Matter ◽  
Mineral Component ◽  
Early Paleozoic ◽  
Shell Material ◽  
Complete Replacement ◽  
Weathering Processes ◽  
Geological Past ◽  
Chernyshev Ridge ◽  
Crystalline Aggregates

The analysis of paleontological data, the study of mineral matter transformation involving live organisms in various rocks is important for the understanding of the events of the geological past. The aim of this work is to identify the bio-genic factor in the process of pseudo-morphogenesis in the shell sashes of the Early Silurian brachiopods from the car-bonate rocks of the Chernyshev Ridge. Structural and microscopic methods (Shimadzu XRD 6000; Fourier spectrometer InfraLum FT-02; JSM 6400 JEOL; VEGA3 TESCAN; MIN-8) were used to study quartz pseudomorphoses in the sashes of four shells of the Early Silurian brachiopods Borealis sр. of Pentamerida order from the carbonate strata of the Chernyshev Ridge. The salicification of the brachiopod shell walls resulted in the complete replacement of the original carbonate skeleton with a change in its structural organization. It is established that quartz is the main mineral component of the intra-shell material and secondary dolomite crystals and newly formed calcite aggregates. The paper discusses the participation of Early Paleozoic and modern cyanobacterial symbionts in the replacement of primary calcite with quartz and the formation of quartz crystalline aggregates on the shell walls. It is shown that quartz on the surface of shell sashes and in the intra-shell substance of brachiopods has undergone repeated transformations due to the combination of ancient and modern weathering processes.

scholarly journals Performance characteristics of African Cat fish (Clarias gariepinus) fed varying inclusion levels of silk worm pupae (Anaphe infracta)

2013 ◽  
Vol 42 (1) ◽  
pp. 76-80
Author(s):  
CO Olaniyi ◽  
GO Babasanmi
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Clarias Gariepinus ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Feed Conversion ◽  
Complete Replacement ◽  
Silk Worm

The use of Silkworm (Anaphe infracta) pupae as a protein source was investigated for its ability to replace fishmeal in the diet of Clarias gariepinus, African cat fish. Five dried diets formulated at 40% crude protein were fed to fingerlings of an average initial weight of 14.33g at 0 (control diet), 25, 50, 75 and 100% inclusion levels of silk worm meal. The experiment was conducted for 84 days were measured. Mean weight gain (MWG), specific growth rate (SGR), feed conversion ratio (FCR). The five inclusion levels of silk worm pupae supported the growth of Clarias gariepinus fingerlings, the growth and feed utilization were favoured by high inclusion level of silk worm meal. Significant differences (p<0.05) were observed among the treatments, although there were no significant differences (p>0.05) in the growth parameters between 50% and 75% inclusion levels. The 100% silk worm pupae meal inclusion gave the best final mean weight gain of 10.29g specific growth rate of 0.93%, feed conversion ratio of 2.18 and protein efficiency ratio (PER) of 0.012. The carcass protein and lipid contents increased compared to the levels of both at the beginning of the experiment. Even though, there were no significant differences (p>0.05) among proximate composition of the fish groups fed 25, 50 and 75%. The results showed that diet consists of 100% silk worm meal could be used as a complete replacement for fish meal in the diet formulation for Clarias gariepinus fingerlings. DOI: http://dx.doi.org/10.3329/bjas.v42i1.15787 Bang. J. Anim. Sci. 2013. 42 (1): 76-80

scholarly journals Application areas of phosphogypsum in production of mineral binders and composites based on them: a review of research results

2018 ◽  
Vol 149 ◽  
pp. 01012 ◽  
Author(s):  
Leonid Dvorkin ◽  
Nataliya Lushnikova ◽  
Mohammed Sonebi
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Industrial Wastes ◽  
Cement Clinker ◽  
Complete Replacement ◽  
Slaked Lime ◽  
The Impact ◽  
Furnace Slag

The increase of the consumption of gypsum products in construction industry with a limited amount of natural gypsum deposits requires alternative sources of gypsum-containing raw materials. In some countries which have fertilizers industry plants, the problem can be solved using industrial wastes, e.g. phosphorgypsum – a byproduct of fertilizers’ production. Kept in dumps over decades, phosphorgypsum is subjected to the chemical changes due to washing out impurities with rain and other natural factors. However, there are observed deviations of harmful impurities in dumped PG depending on its age., Phosphorgypsum of any age requires chemical treatment to neutralize remains of phosphorus and sulfuric acids, fluorine compounds. According to our researches one of the most simple and effective method of neutralization the impurities is using lime-containing admixtures. The paper presents results of laboratory tests of phosphorgypsum as a component of clinker and non-clinker binders. There were investigated the impact of phosphorgypsum as admixture for clinker binders to substitute natural gypsum. Neutralized phosphorgypsum can be applied as mineralizing admixture in calcination of Portland cement clinker. Adding 2 to 2.5% of phosphorgypsum as setting time regulator resulted in a similar physical and mechanical properties compared to mix made with natural gypsum. Another important area of phosphorgypsum application is sulphate activatoion of low-clinker blast-furnace slag cement (clinker content is less than 19%). According to results, the incorporation of phosphorgypsum as sulphate activator in cement has the better effect as natural gypsum. Other development has been carried out to modify the phosphorgypsum binder properties. Complex additive consisted of polycarboxylate-based superplasticizer and slaked lime permitted an increase mechanical properties of hardened phosphorgypsum binder due to significant a reduction of water consumption. Such modified binder can be used as partial or complete replacement of gypsum binder for filling cements and finishing plasters. It can substitute gypsum in non-clinker binders like supersulphated cements. There were also developed compositions of supersulphated cements based on low-alumina blast furnace slag and phosphorgypsum. Supersulphated cements were tested in normal-weight and light-weight concrete.

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