PROTECTION OF ALUMINUM 6061 USED IN WATER VEHICLES FROM FLOUR FROM SALT CORROSION BY COATING

2021 ◽  
Vol 0 (15) ◽  
pp. 0-0
Author(s):  
Senai YALÇINKAYA ◽  
Kenan KOÇYİĞİT

Aim: Every country in the world develops defense strategies in order to protect their borders and to be cautious against attacks from outside, according to their geographical locations. They use underwater and surface vehicles to meet the defense needs of countries that have coasts on seas or oceans. These vehicles need to be light in order to have low fuel consumption and high mobility. Method: Aluminum and aluminum alloy materials are generally used in these vehicles in order to meet these requirements and also to have high strength. In these vehicles, which are in motion in water, corrosion and abrasions occur on the surfaces due to high pressure and friction. Coating methods are applied to minimize these corrosions and abrasions. The selection of aluminum to be applied to these coating methods and the heat treatments to be applied to aluminum materials before coating will be evaluated. In this study, by giving examples of coating types, studies will be carried out on how much the formation of corrosion on aluminum surfaces reduces or prevents. Salt fog test will be applied in order to determine the decrease in the amount of corrosion formation. Salt fog testing will be performed in accordance with the MIL-STD-810G standard. Samples will be prepared for the studies to be carried out on the aluminum 6061 alloys. These samples will be aged by T6 heat treatment. After the aging process, for anodized coating types such as type 1 class 3, type 2 class 1 type 2 class 2 type 3 class 1 type 3 class 2 from anodic anodized coating types, each sample will be in the salt cabinet for 50 hours each turn to see the difference clearly. will be subjected to the fog test. After every 50 hours, the sample will be left to dry for 50 hours. After 50 hours of drying time, these samples, which were subjected to salt fog test, will be compared with each other before the test under normal conditions and after drying after the test.Results: In this study, it has been tried to determine how the aluminum 6061 alloy, which is one of the most preferred materials for underwater and above-water vehicles, behaves against corrosion after T6 heat treatment and the coating types that should be applied in order to maximize its resistance against this corrosion. Conclusion: When the images taken from the optical microscope were compared, it was observed that the type 3 class 1 type was more durable than the other coating types.

2016 ◽  
Vol 256 ◽  
pp. 69-74
Author(s):  
Zhao Yang ◽  
Guang Xu Wang ◽  
Xue Xuan Xu ◽  
Xiao Long He ◽  
Jian Ning Lu

Thixo-forging has been proved to be able to fabricate bi-metal parts with a complex outline and a relatively regular interface economically. These products have potential applications on high volume stability radiators, brakes, and pistons. However, it is very difficult to evaluate the curved interfaces by micro observations. In this work, Al-22%Si-Cu/Al-7%Si-Mg bi-metal parts were fabricated by thixo-forging; state of the interfaces of the bi-metal parts was investigated by X-ray flaw detector observations and tensile test; optical microscope (OM) observation and scan electron microscope (SEM) observation were applied to assist the analysis. The results show that the metallurgical bonding of the interfaces is of good quality. No large scale flaw was found on the interface in X-ray flaw detector observation. It was found that higher forging pressure decreased the size of the crack on the interface and in the matrix. However, higher forging pressure can slightly improve tensile strength. Large ratio of fresh interface relates to original interface resulted in a slightly better tensile strength. Without heat-treatment, the bi-metal forgings have an average tensile strength of 106 MPa. T6 heat treatment blunted the blades of the plate like crack and nodulized the defects, T6 heat treatment also decreased the size of the Si particles. As a result, the average tensile strength of the bi-metal forgings increased to 200 MPa.


2006 ◽  
Vol 59 (suppl_4) ◽  
pp. ONS-336-ONS-346 ◽  
Author(s):  
Emidio Procaccini ◽  
Georg Dorfmüller ◽  
Martine Fohlen ◽  
Christine Bulteau ◽  
Olivier Delalande

Abstract OBJECTIVE: Hypothalamic hamartomas (HHs) require surgical treatment in patients presenting with refractory epilepsy. METHODS: The authors report on a single-center series of 33 patients (24 males, 9 females) who underwent surgery between January 1997 and April 2004. They experienced several types of seizure (gelastic, tonic, partial, atonic, generalized tonic-clonic, dacrystic, infantile spasm, mental retardation, and behavioral and endocrino-logical abnormalities). Forty-nine interventions were carried out. Every patient, with the exception of the first, underwent hamartoma disconnection (pterional approach, six patients; endoscopy, 15 patients; both, 11 patients). The endoscopic approach was carried out with a frameless stereotactic system to enhance feasibility and efficacy of the disconnecting procedure. RESULTS: Surgery-related neurological complications occurred in two patients, both after a pterional microsurgical approach. Furthermore, two patients experienced pan-hypopituitarism and one patient experienced transitory central insipid diabetes. All patients but one showed recovery or considerable improvement of their epilepsy (Engel Class 1, 48.5%; Engel Class 2, 3%; Engel Class 3, 45.5%; mean follow-up duration, 1 yr 7 mo). CONCLUSION: According to the proposed classification of sessile HH into four types, the best candidates for endoscopic disconnection are Type 2 and Type 3 HHs. In the present series, 90% of patients affected by Type 2 HH became seizure free and the remaining 10% improved; of those with Type 3 HH at presentation, 35.3% recovered and 60% improved. Neuropsychological and endocrinological test results showed improvement in many patients. Data from our series demonstrate that frameless stereotactic endoscopic disconnection should be considered as the treatment of choice in the presence of favorable anatomic conditions.


Author(s):  
A.M. Satarkulova

The assessment and dynamic control over students’ status is a very important task. It allows timely detection of prenosological status prior to pathology and health maintenance in students. The objective of the paper is to assess the adaptive abilities of the body, to analyze changes in heart rate variability indicators in students with various types of autonomic regulation, to identify prenosological status and precursory pathological symptoms. Materials and Methods. The study enrolled 302 students from India, aged 21.54±1.43. Programming complex «Psychophysiologist» was used to register the main HRV parameters within 5 minutes. Health status was evaluated according to the index of functional changes and the scale of functional states. Results. N.I. Shlyk (2009) distinguished two groups of students with different types of autonomic regulation: type 1 (53 %) with moderate and type 2 (5 %) with marked characteristics of central regulation profile, type 3 (35 %) with moderate and type 4 (7 %) with marked characteristics of autonomous regulation profile. Main parameters of HRV and adaptation potential were defined for each student.All the parameters characterized functional and health status. Conclusions. It was shown that 82 % of trial subjects (type 1), 53 % (type 2), 94 % (type 3) and 95 % (type 4) demonstrated satisfactory adaptation and their physiological processes were at an optimal level. 18 % of students (type 1) demonstrated reduced adaptive abilities of the body. Moreover, they were under moderate stress. 47 % of subjects (type 2) were also under a significant stress, which was proven by excessively high SI, low SDNN and TP, and an increased index of functional changes. 5 % of students (type 4) revealed dysfunctional characteristics in the heart rhythm, peculiar to pathology. Keywords: foreign students, heart rate variability, types of autonomic regulation, adaptation potential, functional status. Оценка состояния студентов и динамический контроль за ним является важной задачей, поскольку позволяет своевременно выявлять у студентов донозологические состояния, предшествующие патологии, и способствовать сохранению здоровья. Цель. Оценка адаптивных возможностей организма, анализ изменений показателей вариабельности сердечного ритма у студентов с различными типами вегетативной регуляции, выявление донозологических состояний и ранних признаков патологии. Материалы и методы. В исследовании участвовало 302 студента в возрасте 21,54+1,43 года из Индии. Регистрировались основные параметры ВСР в течение 5 мин с использованием программно-аппаратного комплекса «Психофизиолог». Состояние и уровень здоровья оценивались по индексу функциональных изменений и шкале функциональных состояний. Результаты. По способу, предложенному Н.И. Шлык, выделены группы студентов с различными типами вегетативной регуляции: I (53 %) и II типы (5 %) – с умеренным и выраженным преобладанием центрального контура регуляции соответственно, III (35 %) и IV типы (7 %) – с умеренным и выраженным преобладанием автономного контура регуляции соответственно. У каждого из студентов определены основные параметры ВСР и адаптационного потенциала, характеризующие функциональное состояние и уровень здоровья. Выводы. Показано, что для 82 % обследуемых с I типом, 53 % со II типом, 94 % c III типом и 95 % с IV типом регуляции характерно состояние удовлетворительной адаптации, физиологические процессы сохраняются на оптимальном уровне. В группе студентов I типа у 18 % студентов адаптивные возможности организма снижены, выявлено состояние умеренного напряжения. У 47 % обследуемых II типа также зафиксировано состояние резко выраженного напряжения, индикатором которого является чрезмерно высокое значение SI, низкие величины SDNN и ТP, повышенное значение индекса функциональных изменений. В группе студентов с IV типом у 5 % учащихсяв регуляции ритма сердца выявлены дисфункциональные признаки, характерные для патологии. Ключевые слова: иностранные студенты, вариабельность сердечного ритма, типы вегетативной регуляции, адаптационный потенциал, функциональное состояние.


1954 ◽  
Vol 32 (1) ◽  
pp. 119-125
Author(s):  
W. Wood ◽  
Eina M. Clark ◽  
F. T. Shimada ◽  
A. J. Rhodes

Studies on the basic immunology of poliomyelitis in Canadian Eskimos have been continued. Some 87 sera collected from Eskimos at Pangnirtung, Baffin Island, have been examined for the presence of Type 1 and Type 3 poliomyelitis antibody by quantitative tests in tissue cultures. The same sera were previously examined for Type 2 antibody by quantitative tests in mice. The results of the three determinations are now presented together for comparison. These sera came from Eskimos aged 2 to 72 years of age. None of the Eskimos showed any evidence of paralysis. Examination of the medical records did not suggest that any paralytic disease had been present in this part of Baffin Island. Very few of the sera showed the presence of poliomyelitis antibody; thus, Type 1 antibody was demonstrated in the sera of 8%, Type 2 antibody in the sera of 9%, and Type 3 antibody in the sera of 14%. No significant number of Eskimos below the age of 45 years had acquired poliomyelitis antibody. The antibody titers mostly ranged between 10−1.0 and 10−2.0, and were significantly lower than the titers customarily found in recently paralyzed cases. These findings suggest that poliomyelitis infection occurred in Pangnirtung Eskimos many years before the date on which the samples were taken (1951). These results point to the worldwide prevalence of the three types of poliomyelitis virus.


1977 ◽  
Vol 40 (3) ◽  
pp. 626-646 ◽  
Author(s):  
C. K. Knox ◽  
S. Kubota ◽  
R. E. Poppele

1. Responses of DSCT neurons to random electrical stimulation of peripheral nerves of the hindleg at group I intensity were studied using cross-correlation analysis of the output spike train with the stimulus. Three types of response were found: type 1 was due to monosynaptic activation of DSCT cells, type 2 resulted from inhibition of those cells, and type 3 was due to a long-latency excitation that was probably polysynaptic. 2. Most of the units studied responded to stimulation of both proximal and distal flexor and extensor nerves. The extensive convergence of afferent input on DSCT cells is much greater than has been observed previously, with type 2 and type 3 responses totaling 80% of the observed responses. We attribute this to the sensitivity of the analysis in detecting small changes in postsynaptic excitability. 3. The results of the study, particularly the derivation of postsynaptic excitability changes, generally confirm those of earlier work employing intracellular recording. 4. By varying stimulus rate and stimulus intensity in the group 1 range and simulating the resulting correlations, we conclude that excitability changes in DSCT cells are the net result of complex interactions involving excitation and inhibition. A summary of these findings is presented as a model for the minimum circuitry necessary to account for the observed behavior.


2021 ◽  
Vol 47 (02) ◽  
pp. 192-200
Author(s):  
James S. O'Donnell

AbstractThe biological mechanisms involved in the pathogenesis of type 2 and type 3 von Willebrand disease (VWD) have been studied extensively. In contrast, although accounting for the majority of VWD cases, the pathobiology underlying partial quantitative VWD has remained somewhat elusive. However, important insights have been attained following several recent cohort studies that have investigated mechanisms in patients with type 1 VWD and low von Willebrand factor (VWF), respectively. These studies have demonstrated that reduced plasma VWF levels may result from either (1) decreased VWF biosynthesis and/or secretion in endothelial cells and (2) pathological increased VWF clearance. In addition, it has become clear that some patients with only mild to moderate reductions in plasma VWF levels in the 30 to 50 IU/dL range may have significant bleeding phenotypes. Importantly in these low VWF patients, bleeding risk fails to correlate with plasma VWF levels and inheritance is typically independent of the VWF gene. Although plasma VWF levels may increase to > 50 IU/dL with progressive aging or pregnancy in these subjects, emerging data suggest that this apparent normalization in VWF levels does not necessarily equate to a complete correction in bleeding phenotype in patients with partial quantitative VWD. In this review, these recent advances in our understanding of quantitative VWD pathogenesis are discussed. Furthermore, the translational implications of these emerging findings are considered, particularly with respect to designing personalized treatment plans for VWD patients undergoing elective procedures.


2021 ◽  
Author(s):  
Hui Xu ◽  
Lei Chen ◽  
Wansuo Duan

AbstractThe optimally growing initial errors (OGEs) of El Niño events are found in the Community Earth System Model (CESM) by the conditional nonlinear optimal perturbation (CNOP) method. Based on the characteristics of low-dimensional attractors for ENSO (El Niño Southern Oscillation) systems, we apply singular vector decomposition (SVD) to reduce the dimensions of optimization problems and calculate the CNOP in a truncated phase space by the differential evolution (DE) algorithm. In the CESM, we obtain three types of OGEs of El Niño events with different intensities and diversities and call them type-1, type-2 and type-3 initial errors. Among them, the type-1 initial error is characterized by negative SSTA errors in the equatorial Pacific accompanied by a negative west–east slope of subsurface temperature from the subsurface to the surface in the equatorial central-eastern Pacific. The type-2 initial error is similar to the type-1 initial error but with the opposite sign. The type-3 initial error behaves as a basin-wide dipolar pattern of tropical sea temperature errors from the sea surface to the subsurface, with positive errors in the upper layers of the equatorial eastern Pacific and negative errors in the lower layers of the equatorial western Pacific. For the type-1 (type-2) initial error, the negative (positive) temperature errors in the eastern equatorial Pacific develop locally into a mature La Niña (El Niño)-like mode. For the type-3 initial error, the negative errors in the lower layers of the western equatorial Pacific propagate eastward with Kelvin waves and are intensified in the eastern equatorial Pacific. Although the type-1 and type-3 initial errors have different spatial patterns and dynamic growing mechanisms, both cause El Niño events to be underpredicted as neutral states or La Niña events. However, the type-2 initial error makes a moderate El Niño event to be predicted as an extremely strong event.


2021 ◽  
Vol 13 (4) ◽  
pp. 2389
Author(s):  
Jung-Shun Chen

The indoor air of a hospital is always full of bacteria and viruses due to patients with different diseases. These bacteria and viruses could be highly infectious to the people in the hospital irrespective of their health conditions, and could be hazardous to the patients, their care takers, and hospital staff. Thus, keeping a good hospital air quality is very essential to the operation of the hospital. This study aims at enhancing ventilation of the interior lighting of hospitals with germicidal capabilities. Air disinfection is accomplished by adding the specially designed disinfecting filters and fans to existing embedded lamps in the hospitals. The embedded lamp has a square shape of 601 mm in width and 112 mm in thickness. In the design stage, the air flow inside the embedded lamp with the added filters and fans was investigated by numerical simulation using a computational fluid dynamics (CFD) tool. Three designs, referred to as Types 1, 2, and 3, were evaluated using steady-state CFD flow simulations. The ventilation rate of the Type 1 design was about 251.9 CMH, and 348.3 CMH for the Type 2 design by increasing the fan outlet area. However, even though the ventilation was increased by 34%, the flow field of the Type 2 design was not uniform, resulting in flows being circulated around the side locations. Thus, the Type 3 design further treats this aspect by streamlining the outlet geometry and adding flow guiding vanes to reduce flow resistance and flow unsteadiness; the corresponding air ventilation rate reached 376.3 CMH. Hence, the Type 3 design was fabricated and tested. The test results confirm that the design not only has a higher ventilation rate but also operates under a smaller pressure drop, thus accomplishing the goal of providing good air quality in the hospital environment efficiently. Moreover, the associated flow noise is reduced by about 8 dBA. Hence, both an increase in the air ventilation rate and a reduction of noise are achieved simultaneously by the present method.


Author(s):  
Mi Hyeon Seong ◽  
Eunyoung Shin ◽  
Sohyune Sok

The purpose of this study is to identify the types of perception of successful aging in middle-aged men and to analyze and describe the characteristics of each type of successful aging perception of middle-aged men in South Korea. This study uses an exploratory study design, applying the Q methodology, which is a subjective research method. The participants were 25 middle-aged men (40 to 60 years old) living in C, Y, and B cities, which were P-samples that were judged to best reveal the successful aging of middle-aged men. In this study, principal component analysis of the PQ method program was used. The five perception types of successful aging among middle-aged men are Type 1 for the “leisure type”, Type 2 for the “mature type”, Type 3 for the “health-oriented type”, Type 4 for the “patriarchal type”, and Type 5 for the “family-centered type”. The mature type had the highest variance among the five types, and the leisure type was the type that showed the second-highest variance. In nursing practice, nurses need to pay attention to the successful aging perceptions of middle-aged Korean men for their successful aging in the future.


Author(s):  
Dylan Trundell ◽  
Anne Skalicky ◽  
Hannah Staunton ◽  
Asha Hareendran ◽  
Stephanie Le Scouiller ◽  
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