Comparative evaluation of various testing methods for FCC catalysts

2021 ◽  
Vol 05 ◽  
pp. 54-61
Author(s):  
K.I. Dement’ev ◽  
◽  
T.A. Palankoev ◽  
Keyword(s):  
Comparative Evaluation ◽  
Fluidized Bed Reactors ◽  
Testing Methods ◽  
Laboratory Methods ◽  
Advantages And Disadvantages ◽  
Riser Reactor ◽  
Modern Methods ◽  
Industrial Unit ◽  
Fcc Catalysts ◽  
Cracking Catalysts

The article discusses modern methods of stabilization and testing of the activity of cracking catalysts (FCC). Laboratory methods for evaluating cracking catalysts using fixed and fluidized bed reactors are compared, and their advantages and disadvantages are discussed. The correspondence of material balances of cracking was experimentally determined using various laboratory methods and a pilot plant with a riser reactor in comparison with data of industrial unit. Based on the analysis of the results obtained, recommendations are given for the most relevant testing of cracking catalysts.

Genotypic Methods for HIV Drug Resistance Monitoring: The Opportunities and Challenges Faced by China

2019 ◽  
Vol 17 (4) ◽  
pp. 225-239 ◽  
Author(s):  
Lulu Zuo ◽  
Ke Peng ◽  
Yihong Hu ◽  
Qinggang Xu
Keyword(s):  
Drug Resistance ◽  
Virological Suppression ◽  
Testing Methods ◽  
Hiv Drug Resistance ◽  
Advantages And Disadvantages ◽  
Hiv Epidemic ◽  
Routine Surveillance ◽  
The World ◽  
Global Project ◽  
Hiv 1

AIDS is a globalized infectious disease. In 2014, UNAIDS launched a global project of “90-90-90” to end the HIV epidemic by 2030. The second and third 90 require 90% of HIV-1 infected individuals receiving antiretroviral therapy (ART) and durable virological suppression. However, wide use of ART will greatly increase the emergence and spreading of HIV drug resistance and current HIV drug resistance test (DRT) assays in China are seriously lagging behind, hindering to achieve virological suppression. Therefore, recommending an appropriate HIV DRT method is critical for HIV routine surveillance and prevention in China. In this review, we summarized the current existing HIV drug resistance genotypic testing methods around the world and discussed the advantages and disadvantages of these methods.

Small specimen techniques for estimation of tensile, fatigue, fracture and crack propagation material model parameters

2021 ◽  
pp. 030932472110252
Author(s):  
Julija Kazakeviciute ◽  
James Paul Rouse ◽  
Davide Focatiis ◽  
Christopher Hyde
Keyword(s):  
Fatigue Fracture ◽  
Structural Integrity ◽  
Standard Specimen ◽  
Creep Behaviour ◽  
Parameter Determination ◽  
Model Parameters ◽  
Small Specimen ◽  
Testing Methods ◽  
Advantages And Disadvantages ◽  
Tensile Fatigue

Small specimen mechanical testing is an exciting and rapidly developing field in which fundamental deformation behaviours can be observed from experiments performed on comparatively small amounts of material. These methods are particularly useful when there is limited source material to facilitate a sufficient number of standard specimen tests, if any at all. Such situations include the development of new materials or when performing routine maintenance/inspection studies of in-service components, requiring that material conditions are updated with service exposure. The potentially more challenging loading conditions and complex stress states experienced by small specimens, in comparison with standard specimen geometries, has led to a tendency for these methods to be used in ranking studies rather than for fundamental material parameter determination. Classifying a specimen as ‘small’ can be subjective, and in the present work the focus is to review testing methods that utilise specimens with characteristic dimensions of less than 50 mm. By doing this, observations made here will be relevant to industrial service monitoring problems, wherein small samples of material are extracted and tested from operational components in such a way that structural integrity is not compromised. Whilst recently the majority of small specimen test techniques development have focused on the determination of creep behaviour/properties as well as sub-size tensile testing, attention is given here to small specimen testing methods for determining specific tensile, fatigue, fracture and crack growth properties. These areas are currently underrepresented in published reviews. The suitability of specimens and methods is discussed here, along with associated advantages and disadvantages.

CURRENT STATE OF THE PROBLEM OF DRAINAGE FOR NEUROGENIC BLADDER

2021 ◽  
pp. 30-38
Author(s):  
Игорь Александрович Артюхов ◽  
Владимир Васильевич Кузьменко ◽  
Андрей Владимирович Кузьменко ◽  
Тимур Асланбекович Гяургиев
Keyword(s):  
Urinary Tract ◽  
Neurogenic Bladder ◽  
Lower Urinary Tract ◽  
Advantages And Disadvantages ◽  
Economic Significance ◽  
Relevant Today ◽  
Modern Methods ◽  
Neurogenic Disorders ◽  
Neurogenic Dysfunction ◽  
Lower Urinary

Данный литературный обзор посвящен одной из актуальных проблем современной урологии - нейрогенной дисфункции мочевыводящих путей. Нейрогенная дисфункция нижних мочевыводящих путей является одной из важнейших проблем современной урологии, что обусловлено ее высокой распространенностью, частотой вторичных осложнений со стороны мочевыделительной системы и социально-экономической значимостью. Распространенность нейрогенного мочевого пузыря среди пациентов, перенесших острое нарушение мозгового кровообращения, варьирует от 15 % до 94 % и зависит от времени, прошедшего с момента сосудистого события. В статье представлены патофизиологические механизмы, лежащие в основе данной патологии, подробно рассмотрены современные методы дренирования нижних мочевыводящих путей, их преимущества и недостатки. К современным способам дренирования при нейрогенных расстройствах нижних мочевыводящих путей относят периодическую (интермиттирующую) катетеризацию, постоянную катетеризацию и надлобковую цистостомию. Анализ доступной литературы указывает на то, что частота осложнений, ассоциированных как с нейрогенной дисфункцией мочевого пузыря, так и с используемыми способами дренирования, продолжает оставаться достаточно высокой. Таким образом, проблема профилактики катетер-ассоциированных осложнений и улучшения качества жизни данной категории больных на сегодняшний день продолжает оставаться актуальной и требует проведения дальнейших исследований в данной области This literature review is devoted to one of the most pressing problems of modern urology - neurogenic urinary tract dysfunction. Neurogenic dysfunction of the lower urinary tract is one of the most important problems of modern urology, due to its high prevalence, frequency of secondary complications from the urinary system, and socio-economic significance. The prevalence of neurogenic bladder among patients who have experienced acute cerebrovascular accident varies from 15 % to 94 % and depends on the time elapsed since the vascular event. The article presents the pathophysiological mechanisms underlying this pathology, discusses in detail modern methods of drainage of the lower urinary tract, their advantages and disadvantages. Modern methods of drainage for neurogenic disorders of the lower urinary tract include periodic (intermittent) catheterization, permanent catheterization, and suprapubic cystostomy. Analysis of the available literature indicates that the frequency of complications associated with both neurogenic bladder dysfunction and the drainage methods used continues to be quite high. Thus, the problem of preventing catheter-associated complications and improving the quality of life of this category of patients continues to be relevant today and requires further research in this area

scholarly journals Rehabilitation of patients after acute cerebrovascular accident followed by hemodynamically significant stenoses of the brachiocephalic arteries

2020 ◽  
pp. 25-29
Author(s):  
A. G. Shapovalova ◽  
V. G. Rapovka ◽  
A. O. Sobolevskaya ◽  
T. N. Negoda
Keyword(s):  
Carotid Arteries ◽  
Atherosclerotic Lesion ◽  
Cerebral Stroke ◽  
Cerebrovascular Accidents ◽  
Advantages And Disadvantages ◽  
Acute Cerebrovascular Accident ◽  
Modern Methods ◽  
Epidemiological Significance ◽  
Brachiocephalic Arteries

The literature data is presented covering epidemiological significance of acute cerebrovascular accidents (CVA) in‑ cidence in patients with brachiocephalic arteries lesion. The role of atherosclerotic lesion of carotid arteries in the develop‑ ment of ischemic cerebral stroke is shown. The basic methods for diagnosis of carotid arteries lesion has been analyzed as well as their availability and informative value. A comparative analysis of modern methods for surgical treatment of athero‑ sclerotic lesion of carotid arteries such as carotid endarterectomy (classic and eversion), endovascular procedure has been done. The main advantages and disadvantages of these treatment methods, indications and contraindications for their use are described. The timing of cerebral revascularization in the acute and delayed periods of ischemic stroke was estimated. The role of bilateral lesion of the carotid territory is shown as well as approaches to the treatment strategy of such patients.

scholarly journals Determination of 137Cs in Sea Water Samples Using Gamma Spectrometry

2020 ◽  
Vol 13 ◽  
pp. 247
Author(s):  
N. Evaggeliou ◽  
Ch. Lykomitrou ◽  
A. Zafiropoulou
Keyword(s):  
Gamma Spectrometry ◽  
Comparative Evaluation ◽  
Sea Water ◽  
Germanium Detector ◽  
Advantages And Disadvantages ◽  
High Purity Germanium ◽  
Co Precipitation ◽  
Radioanalytical Procedures

In the present study a comparative evaluation of two methods for 137Cs determination (pretreatment for gamma spectrometry) is attempted. One of them is the conventional AMP (ammonium molybdophosphate, (ΝΗ4)3Ρ(Μo3O10)4) method (radiochemical treatment based on coprecipitation) and the other one is a method based on pre-concentration of cesium in situ by using the Mark III Centrifugal Pump. The pump, which is described analytically in the study, is composed of a mo­tor (pump), four cartridge housings (containing the scavengers), a flow meter and a pressure tube (containing the battery pack and the timer board). For justification, this method is compared with the AMP co-precipitation one. Following up the radioanalytical procedures, the gamma spectrometry system (relative efficiency of high purity germanium detector 90%) is also demonstrated, as conformed to mea­ suring obtained parameters. Finally, the advantages and disadvantages of these two methods are recorded and the application of each one is suggested.

scholarly journals Modern therapeutic options in the treatment of bacterial vaginosis

2020 ◽  
Vol 69 (3) ◽  
pp. 39-45
Author(s):  
Evgeny F. Kira ◽  
Yulia V. Khalturina
Keyword(s):  
Bacterial Vaginosis ◽  
Therapeutic Options ◽  
Diagnosis And Treatment ◽  
Therapeutic Approaches ◽  
Advantages And Disadvantages ◽  
Modern Methods

This article reviews the pathogenetic aspects of bacterial vaginosis and modern methods of diagnosis and treatment of vaginal microbiocenosis disorders. The advantages and disadvantages of the available therapeutic approaches are discussed, and new opportunities and prospects in the treatment of bacterial vaginosis are highlighted.

scholarly journals MODERN METHODS OF THE TREATMENT OF ESOPHAGEAL STRICTURES IN BULLOUS EPIDERMOLYSIS CHILDREN

2019 ◽  
Vol 21 (1) ◽  
pp. 54-61
Author(s):  
Artem V. Tupylenko ◽  
M. M. Lokhmatov ◽  
N. N. Murashkin ◽  
V. I. Oldakovskiy
Keyword(s):  
Esophageal Stenosis ◽  
Optimal Method ◽  
Advantages And Disadvantages ◽  
Endoscopic Gastrostomy ◽  
Treatment And Prevention ◽  
Fluoroscopic Control ◽  
Esophageal Strictures ◽  
Modern Methods ◽  
Peg Tube ◽  
Surgical Operations

The review presents modern approaches to the treatment and prevention of the benign esophageal stenosis in epidermolysis bullosa (EB) children. There are discussed advantages and disadvantages of such main methods as conservative, intraluminal recanalization, and surgical operations used in the treatment of esophageal strictures in EB patients. The features of anesthesia in BE patients are described. Balloon dilatation of esophageal strictures under endoscopic or fluoroscopic control has been shown to be the optimal method of treating patients. In severe BE children with refractory esophageal stenosis, developmental delay, and nutritional status disorders, to perform hyperalimentation by virtue of the percutaneous endoscopic gastrostomy (PEG) tube is recommended.

scholarly journals ANALYSIS OF EXISTING METHODS FOR URANIUM-PLUTONIUM MIXED NITRIDE FUEL FAB-RICATION IN RUSSIA AND ABROAD

2020 ◽  
Vol 63 (6) ◽  
pp. 12-18
Author(s):  
Maxim S. Fedorov ◽  
Nikolay A. Baydakov ◽  
Alexander N. Zhiganov ◽  
Dmitry V. Zozulya
Keyword(s):  
High Voltage ◽  
Electric Pulse ◽  
Industrial Applications ◽  
Ceramic Technology ◽  
Laboratory Methods ◽  
Advantages And Disadvantages ◽  
Nitride Fuel ◽  
Powder Pressing ◽  
Uranium Nitride ◽  
Uranium Plutonium

This paper presents a review and a brief analysis of existing methods for producing mixed uranium nitride and plutonium, developed by both Russian and foreign scientists. The main parameters of the processes are considered, and their advantages and disadvantages are studied. Currently, the main areas of nitride fuel production are the metal hydride method and carbothermic reduction from the starting oxides. The methods are traditional ceramic technology. The starting products for the manufacture of nitride fuel powder can be either oxides (uranium dioxide and plutonium dioxide) or metals (uranium, plutonium and their alloys). To date, the technology for the manufacture of nitride fuel powder has not been finally selected. When considering existing methods, significant emphasis was placed on industrial applications and the simplicity of the hardware design processes. The laboratory methods are reflected in the work, which make it possible to simplify the process and reduce the costs of obtaining powders of mixed uranium and plutonium nitrides. However, they have significant difficulties in the technological implementation and low productivity of the processes. Of special interest among laboratory methods for producing mixed uranium and plutonium nitrides is the method of high-voltage electric pulse consolidation. This method allows sintering of tablets at the stage of powder pressing from mixed uranium and plutonium nitrides by passing a short high-voltage discharge with a power of several kW directly through the powder.

A survey of multi-agent organizational paradigms

2004 ◽  
Vol 19 (4) ◽  
pp. 281-316 ◽  
Author(s):  
BRYAN HORLING ◽  
VICTOR LESSER
Keyword(s):  
Comparative Evaluation ◽  
Organizational Design ◽  
Performance Characteristics ◽  
Multi Agent Systems ◽  
Organizational Strategies ◽  
Agent Systems ◽  
Advantages And Disadvantages ◽  
Multi Agent ◽  
Selection Of ◽  
Organizational Paradigms

Many researchers have demonstrated that the organizational design employed by an agent system can have a significant, quantitative effect on its performance characteristics. A range of organizational strategies have emerged from this line of research, each with different strengths and weaknesses. In this article we present a survey of the major organizational paradigms used in multi-agent systems. These include hierarchies, holarchies, coalitions, teams, congregations, societies, federations, markets, and matrix organizations. We will provide a description of each, discuss their advantages and disadvantages, and provide examples of how they may be instantiated and maintained. This summary will facilitate the comparative evaluation of organizational styles, allowing designers to first recognize the spectrum of possibilities, and then guiding the selection of an appropriate organizational design for a particular domain and environment.

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