scholarly journals Evaluation of corrosion in steel reinforced concrete with brick waste

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Julieta D. Chelaru ◽  
◽  
Maria Gorea ◽  
Keyword(s):  
Grain Size ◽  
Current Problem ◽  
Preparation Method ◽  
Electrochemical Impedance ◽  
Corrosion Process ◽  
Steel Reinforced Concrete ◽  
Steel Rebar ◽  
Cement Mortars ◽  
A Current ◽  
Anticorrosion Properties

The massive demolition of old buildings in recent years has generated tons of waste, especially brick waste. Thus, a concern of recent research is the use of this waste for the production of environmentally friendly concrete. At the same time, corrosion of the reinforcement steel rebar in classical concrete is a current problem. In this context, in the present paper a study was carried out on the corrosion of metal reinforcement in cement mortars with added brick waste. The corrosion process was analyzed on four compositions of mortars without and with 15%, 25% and 35% brick waste replacing the sand. The brick waste has majority content in SiO2, Al2O3, FeO3 and CaO. The grain size distribution of brick waste was close to that of the sand (dmax = 2 mm). The preparation method of the samples was similar to ordinary mortars. The corrosion action on the rebar in concrete, at different brick waste concentrations, was investigated by electrochemical measurements (polarization curves and electrochemical impedance spectroscopy (EIS)) at 1 month and 26 months. The results obtained at 26 months revealed that the addition of the brick waste in mortar improved the anticorrosion properties in the case of all samples compared with the etalon mortar. The best results were obtained in the case of the sample with 15% brick waste (the efficiency was ≈ 90%). The corrosion intermediary layer formed on the rebar surface was evidenced by SEM-EDX.

Novel magneto-optical recording materials: Bi-substituted garnet films

1991 ◽  
Vol 49 ◽  
pp. 776-777
Author(s):  
Takao Suzuki ◽  
Hossein Nuri
Keyword(s):  
Grain Size ◽  
Amorphous Film ◽  
Nitrogen Atmosphere ◽  
Optical Recording ◽  
Garnet Film ◽  
Media Noise ◽  
Garnet Films ◽  
Order Of Magnitude ◽  
A New Technique ◽  
A Current

For future high density magneto-optical recording materials, a Bi-substituted garnet film ((BiDy)3(FeGa)5O12) is an attractive candidate since it has strong magneto-optic effect at short wavelengths less than 600 nm. The signal in read back performance at 500 nm using a garnet film can be an order of magnitude higher than a current rare earth-transition metal amorphous film. However, the granularity and surface roughness of such crystalline garnet films are the key to control for minimizing media noise.We have demonstrated a new technique to fabricate a garnet film which has much smaller grain size and smoother surfaces than those annealed in a conventional oven. This method employs a high ramp-up rate annealing (Γ = 50 ~ 100 C/s) in nitrogen atmosphere. Fig.1 shows a typical microstruture of a Bi-susbtituted garnet film deposited by r.f. sputtering and then subsequently crystallized by a rapid thermal annealing technique at Γ = 50 C/s at 650 °C for 2 min. The structure is a single phase of garnet, and a grain size is about 300A.

Inhibition Effects of Some Organic Compounds on Zinc Corrosion in 3.5% NaCl

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Viorel Branzoi ◽  
Alina Pruna ◽  
Florina Branzoi
Keyword(s):  
Organic Compounds ◽  
Electrochemical Impedance ◽  
Corrosion Process ◽  
Diffusion Control ◽  
Cathodic Reaction ◽  
Zinc Electrode ◽  
Electrochemical Studies ◽  
Nacl Solution ◽  
Sodium Dodecylsulphate ◽  
Zinc Corrosion

The inhibition of zinc corrosion in 3.5% NaCl solution by some organic compounds (sodium dodecylsulphate (SDS), sodium dodecylbenzosulphonate (SDBS) and sodium 1,4-bis(2-etylhexyl) sulphosuccinate (AOT)) was investigated. The inhibition efficiencies were determined by polarization measurements of the zinc electrode in the solution. Electrochemical impedance spectroscopy (EIS) was also used for electrochemical studies of zinc electrode in this medium. The results showed that the used surfactants inhibit the cathodic reaction of hydrogen evolution and at low anodic overvoltage the corrosion process is under activation control, while at high anodic overvoltage the process is under diffusion control.

scholarly journals FRI0431 PROFILE OF INFECTIOUS SPONDYLODISCITIS ACCORDING TO THE SITE: UNIFOCAL VERSUS MULTIFOCAL

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 814.3-814
Author(s):  
A. Ben Tekaya ◽  
L. Ben Ammar ◽  
M. Ben Hammamia ◽  
O. Saidane ◽  
S. Bouden ◽  
...  
Keyword(s):  
Current Problem ◽  
Common Factor ◽  
Cord Compression ◽  
Posterior Arch ◽  
Significant Difference ◽  
Infectious Spondylodiscitis ◽  
Vertebral Biopsy ◽  
Inflammatory Syndrome ◽  
Different Levels ◽  
A Current

Background:Infectious spondylodiscitis is a therapeutic emergency and is a current problem. It can affect the different levels of the spine. Multifocal forms, touching several floors, however remain rare.Objectives:To compare the clinical, biological, radiological and therapeutic aspects of unifocal versus multifocal spondylodiscitis.Methods:This is a retrospective study of 113 patients admitted to our service over a period of 20 years [1998-2018]. The diagnosis of spondylodiscitis was made on the basis of clinical, biological, radiological and bacteriological data. We have divided our population into two groups: unifocal and multifocal spondylodiscitis.Results:Spondylodiscitis was more frequently unifocal (75.2%) than multifocal (24.8%). The average age of the patients was 55.8 years. There were 62 men and 51 women. There was no difference in age and sex between the two groups (p=0.5 and p=0.8, respectively).Diabetes was more frequent in the group of multifocal spondylodiscitis but with no statistically significant difference (p=0.4). No statistically significant difference between the two groups regarding the start mode (p=0.7), the schedule (p=0.3), the presence of neurological signs (p=0.7), fever (p = 0.2), impaired general condition (p=0.6) and biological inflammatory syndrome (p=0.6).Cervical and dorsal spine involvement was more common in multifocal spondylodiscitis (p = 0.02 and p = 0.01; respectively). There were 11 spondylodiscitis involving 2 floors (cervical and dorsal: 2 cases, cervical and lumbar: 3 cases, dorsal and lumbar: 6 cases) and 3 spondylodiscitis involving 3 floors.Radiologically, the presence of vertebral fracture and involvement of the posterior arch was more frequent during the multifocal form (p=0.03 and p=0.001; respectively). The frequency of para-vertebral abscesses, epiduritis and the presence of spinal cord compression were similar in the two groups (p=0.6; p=0.7 and p=0.2, respectively).Tuberculosis was more frequent during the multifocal form (p = 0.05) and brucellosis during the unifocal form (p = 0.03). Disco-vertebral biopsy was performed in 79 cases. It was more often contributory during multifocal spondylodiscitis (p = 0.03).The occurrence of immediate complications was more frequent in multifocal spondylodiscitis but with no statistically significant difference (p=0.2).Conclusion:Multifocal sppondylodiscitis is seen mainly in immunocompromised subjects. Our study found that diabetes is the most common factor in immunosuppression. Note also the predominance of involvement of the posterior elements, tuberculous origin and immediate complications.Disclosure of Interests:None declared

Evaluation of the corrosion behavior of AZ31 magnesium alloy with different protein concentrations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yucong Ma ◽  
Mohd Talha ◽  
Qi Wang ◽  
Zhonghui Li ◽  
Yuanhua Lin
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Surface Film ◽  
Energy Dispersive Spectrometer ◽  
Inhibitory Effect ◽  
Corrosion Process ◽  
High Concentration ◽  
Content Type ◽  
Atomic Force

Purpose The purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L). Design/methodology/approach Electrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film. Findings Experimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance. Originality/value When the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.

scholarly journals Innovative tourism product as a factor in the development of the tourism industry

2020 ◽  
Vol 11 (2) ◽  
pp. 33-40
Author(s):  
I. Kudinova ◽  
Keyword(s):  
Foreign Investment ◽  
Current Problem ◽  
Tourism Industry ◽  
Tourist Industry ◽  
Tourism Product ◽  
Marketing Service ◽  
Favorable Conditions ◽  
Further Development ◽  
A Current ◽  
Trend Direction

The research of the conformation and development of innovative tourist products is a current problem today. The article summarized and systematized the innovative features of the tourist product in order to build the tourist industry and increase the competitiveness of the tourist industry. It stated that innovation is a necessary process in creating a new attractive tourist product, also in creating сonducive conditions for intensifying the activity of investors in the tourist sphere of the country. The following types of innovations in the tourist industry are listed, namely: product, technological, marketing, service, organizational and management innovations and innovations of logistics. The competitive strengths which should be the basis of formation of competitiveness of Ukraine in the field of tourist business, are highlighted, namely: unique healing climate, numerous territories with therapeutic opportunities, considerable historical and cultural potential, attractiveness of our country's tourist industry for foreign investment. Also defined are the problematic directions regarding the tourist attractiveness of Ukraine. Emphasis is placed on the fact that the state should support the development of tourist business in Ukraine in accordance with the following principles: to provide financing in accordance with the needs of the industry, to create favorable conditions for its further development, to determine and maintain priority directions of the development of the industry, to support and protect the Ukrainian and foreign tourists, tour operators and agents and their associations. The popular and new innovative directions of tourist, trends and technologies that are currently in demand with tourists are identified. Each tourist trend direction is described. The main requirements are listed and proposals are made to create an innovative tourist product.

scholarly journals Diagnostic search algorithm for IgE-independent allergic rhinitis

2020 ◽  
Vol 19 (2) ◽  
pp. 69-73
Author(s):  
R. A. Trigubenko ◽  
◽  
E. G. Portenko ◽  
Keyword(s):  
Allergic Rhinitis ◽  
Current Problem ◽  
Search Algorithm ◽  
Eosinophilic Inflammation ◽  
Igg Antibodies ◽  
Secondary Immunodeficiency ◽  
Characteristic Features ◽  
Methods Of Treatment ◽  
Bacterial Superinfection ◽  
A Current

Allergic rhinitis is a widespread disease located at the junction of two specialties: otorhinolaryngology and allergology. Currently, it is characterized by an early onset, often continuously recurring course and refractory to traditional methods of treatment. Unstable remissions, a tendency to complications, and the lack of effectiveness of the therapy suggest that allergic rhinitis occurs against the background of secondary immunodeficiency, a favorable factor for the development of bacterial superinfection on the damaged mucous membrane of the nasal cavity. In conditions of impaired immune homeostasis, the microbial landscape of the nasal mucosa is characterized by polymorphism, bacterial agents can act as an infectious antigen. The article is devoted to a current problem – chronic IgE-independent allergic rhinitis due to allergen-specific lymphocytes or IgG antibodies with the formation of immune complexes. The article reveals the content of the concept of “chronic infectious-dependent allergic rhinitis”, its characteristic features are highlighted and described, the key stages of diagnosis are considered. The importance of knowledge about mediators of chronic eosinophilic inflammation for practitioners is reflected. The work is interdisciplinary in nature, written at the intersection of otorhinolaryngology, allergology and immunology and will be interesting to doctors of various specialties.

scholarly journals Legislation regarding social protection of children and youth in Sweden with particular emphasis on protection from abuse and neglect

Temida ◽  
2003 ◽  
Vol 6 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Slobodan Savic ◽  
Djordje Alempijevic
Keyword(s):  
Social Protection ◽  
Social Care ◽  
Current Problem ◽  
Children And Youth ◽  
Vulnerable Groups ◽  
Psychological Consequences ◽  
Abuse And Neglect ◽  
Professional Contact ◽  
A Current ◽  
Consequences Of Violence

Protection of children from abuse and neglect is a current problem in the world. The consequences of violence against children are very important because they can leave behind permanent bodily injuries up to severe invalidity, as well as psychological consequences which very often lead to transmission of violence into next generations. In most extreme cases death occurs as a consequence of abuse and neglect. In this paper authors present legislation which regulate social protection of children and youth in Sweden, with special emphasis on protection from abuse and neglect. Sweden is a country in which social care of most vulnerable groups including children, was always at the top of priorities. Authors made comparative analysis of Swedish and domestic (Serbian) laws regarding protection of children from violence, with particular emphasis on mandatory report of these cases from professionals who are in regular professional contact with children. Authors will also put emphasis on duties of medical doctors in the system of protection of children and youth from abuse and neglect.

Robotic grasping with obstacle avoidance using octrees

2020 ◽  
Vol 25 (3) ◽  
pp. 7-12
Author(s):  
Rud V.V. ◽  
Keyword(s):  
Control Systems ◽  
Current Problem ◽  
Robot Manipulator ◽  
General Purpose ◽  
Advantages And Disadvantages ◽  
Specific Position ◽  
Recognition Of Objects ◽  
Manipulator Control ◽  
A Current

This paper considers the problems of the integration of independent manipulator control systems. Areas of control of the manipulator are: recognition of objects and obstacles, identification of objects to be grasped, determination of reliable positions by the grasping device, planning of movement of the manipulator to certain positions with avoidance of obstacles, and recognition of slipping or determination of reliable grasping. This issue is a current problem primarily in industry, general-purpose robots, and experimental robots. This paper considers current publications that address these issues. Existing algorithms and approaches have been found in the management of both parts of the robot manipulator and solutions that combine several areas, or the integration of several existing approaches. There is a brief review of current literature and publications on the above algorithms and approaches. The advantages and disadvantages of the considered methods and approaches are determined. There are solutions that cover either some areas or only one of them, which does not meet the requirements of the problem. Using existing approaches, integration points of existing implementations are identified to get the best results. In the process, a system was developed that analyzes the environment, finds obstacles, objects for interaction, poses for grasping, plans the movement of the manipulator to a specific position, and ensures reliable grasping of the object. The next step was to test the system, test the performance, and adjust the parameters for the best results. The resulting system was developed by the research team of RT-Lions, Technik University, Reutlingen. The hardware research robot includes an Intel Realsense camera, a Sawyer Arm manipulator from Rethink Robotics, and an internally grabbing device.

Two remarks about Sudoku squares

2006 ◽  
Vol 90 (519) ◽  
pp. 425-430 ◽  
Author(s):  
A. D. Keedwell
Keyword(s):  
Current Problem ◽  
Latin Square ◽  
Latin Squares ◽  
Critical Set ◽  
Critical Sets ◽  
The Given ◽  
A Current ◽  
Defining Sets

Smallest defining setsA standard Sudoku square is a 9 × 9 latin square in which each of the nine 3 × 3 subsquares into which it can be separated contains each of the integers 1 to 9 exactly once.A current problem is to complete such a square when only some of the cells have been filled. These cells are often called ‘givens’. (Such problems are currently (2005) published daily in British newspapers.) In more mathematical terms, the given filled cells constitute a defining set or uniquely completable set for the square if they lead to a unique completion of the square. If, after deletion of any one of these givens, the square can no longer be completed uniquely, the givens form a critical set. The investigation of critical sets for ‘ordinary’ latin squares is a topic of current mathematical interest. (See [1] for more details.)

Sign in / Sign up

Export Citation Format

Share Document