In order for the working status of the aluminum alloyed hydraulic valve body to be controlled in actual conditions, a new friction and wear design device was designed for the cast iron and aluminum alloyed valve bodies comparison under the same conditions. The results displayed that: (1) The oil leakage of the aluminum alloyed hydraulic valve body was higher than the corresponding oil leakage of the iron body during the initial running stage. Besides during a later running stage, the oil leakage of the aluminum alloyed body was lower than corresponding oil leakage of the iron body; (2) The actual oil leakage of different materials consisted of two parts: the foundation leakage that was the leakage of the valve without wear and wear leakage that was caused by the worn valve body; (3) The aluminum alloyed valve could rely on the dust filling furrow and melting mechanism that led the body surface to retain dynamic balance, resulting in the valve leakage preservation at a low level. The aluminum alloy modified valve body can meet the requirements of hydraulic leakage under pressure, possibly constituting this alloy suitable for hydraulic valve body manufacturing.
In order to study the effects of various gating systems on the casting of a complex aluminum alloyed multi-way valve body, both software simulation analysis and optimization were carried out. Following, the aluminum alloyed multi-way valve body was cast to check the pouring of the aluminum alloy valve body. The computer simulation results demonstrated that compared to the single side casting mode, the casting method of both sides of the gating system would reduce the filling of the external gas, while the air contact time would be lower. Adversely, due to the pouring on both sides, the melt cannot reach at the same time, leading to the liquid metal speed into the cavity to differ, which affected the liquid metal filling stability. The riser unreasonable setting led to the solidification time extension, resulting in a high amount of casting defects during solidification. Also, both gating systems led the entire casting inconsequential solidification. To overcome the latter problems, a straight gate was set at the middle pouring and the horizontal gate diversion occurred on both sides of pouring, which could provide better casting results for the aluminum alloyed multi-valve body.
This paper describes assumptions, goals, methods, results and conclusions related to fuel tank arrangement of a flying wing passenger airplane configuration. A short overview of various fuel tank systems in use today of different types of aircraft is treated as a starting point for designing a fuel tank system to be used on very large passenger airplanes. These systems may be used to move fuel around the aircraft to keep the centre of gravity within acceptable limits, to maintain pitch and lateral balance and stability. With increasing aircraft speed, the centre of lift moves aft, and for trimming the elevator or trimmer must be used thereby increasing aircraft drag. To avoid this, the centre of gravity can be shifted by pumping fuel from forward to aft tanks. The lesson learnt from this is applied to minimise trim drag by moving the fuel along the airplane. Such a task can be done within coming days if we know the minimum drag versus CG position and weight value. The main part of the paper is devoted to wing bending moment distribution. A number of arrangements of fuel in airplane tanks are investigated and a scenario of refuelling – minimising the root bending moments – is presented. These results were obtained under the assumption that aircraft is in long range flight (14 hours), CL is constant and equal to 0.279, Specific Fuel Consumption is also constant and that overall fuel consumption is equal to 20 tons per 1 hour. It was found that the average stress level in wing structure is lower if refuelling starts from fuel tanks located closer to longitudinal plane of symmetry. It can influence the rate of fatigue.
Although chaetognaths inhabiting polar ecosystems are relatively well known, there are few reports on their functioning in the Antarctic coastal plankton community. The presented results provide the first comprehensive description of population structure of chaetognaths in the neritic zone west of the Antarctic Peninsula. The studies were performed on samples collected in Admiralty Bay, from December 1994 to June 1995. Following six chaetognath species were determined: Eukrohnia hamata, E. bathypelagica, E. fowleri, Pseudosagitta gazellae, P. maxima and Solidosagitta marri. The representatives of Eukrohnia were observed almost throughout the research period, whereas those of Pseudosagitta and Solidosagitta were found only during first four months of our investigation. Eukrohnia hamata showed a strong dominance in respect to abundance (max. 445 ind./1000 m3). The mean abundance of all taxa significantly fluctuated in the study period and across weeks. Generally, all species were represented by the first three maturity stages (I-III), individuals stage IV occurred sporadically, and mature specimens (stage V) were not recorded at all. Morphometric analysis of the most abundant species showed distinct differences in their total length and body proportions. Our findings may suggest that chaetognath populations in Admiralty Bay are migrant, dependent on the inflow of water from the Bransfield Strait, but to prove this statement further, round year study is necessary.
One of the applications of tether system is in the field of satellite technology, where the mother ship and satellite equipment are connected with a cable. In order to grasp the motion of this kind of tether system in detail, the tether can be effectively modeled as flexible body and dealt by multibody dynamic analysis. In the analysis and modeling of flexible body of tether, large deformation and large displacement must be considered. Multibody dynamic analysis such as Absolute Nodal Coordinate Formulation with an introduction of the effect of damping force formulation can be used to describe the motion behavior of a flexible body. In this study, a parameter identification technique via an experimental approach is proposed in order to verify the modeling method. An example of swing-up control using the genetic algorithm control approach is performed through simulation and experiment. The validity of the model and availability of motion control based on multibody dynamics analysis are shown by comparison between numerical simulation and experiment.
This work focuses on finding a numerical solution for vehicle acoustic studies and improving the usefulness of the numerical experimental parameters for the development stage of a new automotive project. Specifically, this research addresses the importance of modal cavity damping for vehicle exerts during numerical studies. It then seeks to suggest standardized parameter values of modal cavity damping in vehicular acoustic studies. The standardized value of modal cavity damping is of great importance for the study of vehicular acoustics in the automotive industry because it would allow the industry to begin studies of the acoustic performance of a new vehicle early in the conception phase with a reliable estimation that would be close to the final value measured in the design phase. It is common for the automotive industry to achieve good levels of numerical-experimental correlation in acoustic studies after the prototyping phase because this phase can be studied with feedback from the simulation and experimental modal parameters. Thus, this research suggests values for modal cavity damping, which are divided into two parts due to their behaviour: ξ(x) = -0.0126(x − 100) + 6.15 as a variable function to analyse up to 100 Hz and 6.15% of modal cavity damping constant for studies between 30 Hz and 100 Hz. The sequence of this study shows how we arrived at these values.
Changes in body mass and body reserves of Little Auks (Alle alle) were studied throughout the breeding season. Body mass loss after chick hatching was analyzed with respect to two hypotheses: (1) mass loss reflects the stress of reproduction, (2) mass loss is adaptive by reducing power consumption during flight. Body mass of both males and females increased during incubation, dropped abruptly after hatching, and remained stable until the end of the chick-rearing period. These changes were largely due to change in mass of fat reserves. Body mass, fat, and protein reserves, when corrected for body size, did not differ between sexes at the end of incubation. Female size-corrected body mass at that time was correlated with peak body mass of chicks. The estimated energy savings for flight due to the decline in adult body mass after chick hatching were small compared with the total energy expenditure of adults feedings chicks, which did not support hypothesis (2). The contribution to chick feeding was not equal; the ratio of females to males caught with food for chicks was 1.8. Size-corrected body mass during chick-rearing was lower in females, proportional to their higher chick feeding effort compared with males. Females, in contrast to males, lost protein reserves during chick-rearing. Digestive tract mass of adults increased by half throughout the breeding period. These findings supported elements of hypothesis (1). Despite high energy expenditure rates, both sexes had about 10 g of fat reserves at the end of chick feeding. Body mass of both sexes was constant during the greater part of the chick-feeding period. It was suggested therefore that mass loss is regulated with respect to lower fat reserves required during chick-rearing.
High resolution body surface potential maps and an equivalent current dipole model of the cardiac generator were used to assess the heart state in two abnormal conditions: WPW syndrome with single accessory pathway and local ventricular ischemia. Results of a simulation study and experimental verification of the method for both cardiologic abnormalities are presented. Single accessory pathway in WPW syndrome was simulated as initial ventricular activation at the atrio-ventricular ring. Using a current dipole model of the cardiac generator, the locus of arrhythmogenic tissue was assessed with a mean error of 11 mm. Experimental localization of the accessory pathway in a WPW patient was in good agreement with the invasively obtained site. Local repolarization changes were simulated as shortening of the myocytes action potentials in three regions typical for stenosis of main coronary arteries. Using surface QRST integral maps and dipolar source model, small subendocardial and subepicardial lesions of myocardium were inversely located with a mean error of 9 mm and larger transmural lesions with a considerable mean error of 17 mm. Extent and prevalence of subepicardial or subendocardial type of the lesion were reflected in the dipole moment and orientation. In experimental verification of the method, in 7 of 8 patients that underwent PCI of a single vessel, estimated equivalent current dipole position matched well the treated vessel. The results suggest that diagnostic interpretation of body surface potential maps based on dipolar source model could be a useful tool to assess local pathological changes in the heart.
The coastal zone and estuaries of Quang Ninh and Hai Phong have great potential not only for economic development but also for protection and conservation of biodiversity and ecosystem. Nowadays, due to industrial, agricultural and anthropogenic activities signs of water pollution in the region have been found. The level of surface water pollution can be determined by traditional methods through observatory stations. However, a traditional approach to determine water contamination is discontinuous, and thereby makes pollution assessment of the entire estuary very difficult. Nowadays, remote sensing technology has been developed and widely applied in many fields, for instance, in monitoring water environments. Remote sensing data combined with information from in-situ observations allow for extraction of polluted components in water and accurate measurements of pollution level in the large regions ensuring objectivity. According to results obtained from Spot-5 imagery of Quang Ninh and Hai Phong, the extracted pollution components, like BOD, COD and TSS can be determined with the root mean square error, the absolute mean error and the absolute mean percentage error (%): ±4.37 (mg/l) 3.86 (mg/l), 27%; ±55.32 (mg/l), 48.30 (mg/l), 14%; and ±32.90 (mg/l), 23.38 (mg/l), 28%; respectively. Obtained outcomes guarantee objectivity in assessing water contaminant levels in the investigated regions and show the advantages of remote sensing applications in Resource and Environmental Monitoring in relation to Water – Air – Land.
In this article I try to think about the terms “stories” and “ontologies” in Ewa Domańska’s works: Mikrohistorie. Spotkania w międzyświatach (1999; 2005), Historie niekonwencjonalne (2006), Historia egzystencjonalna (2012), Historia ratownicza (2014) and I try to compare my conclusions with her latest publication. I am interested in the turning point in her thoughts, giving up the theory and methodology of history and switching to the ontology of the dead body. In order to do this I look through these publications and indicate which threads could help work out the excellent, innovative, and fresh conception of Nekros. The main part of the article is a detailed discussion of this. In the other part, I consider how to interpret more traditionally a past description like “cultural memory” and whether Domańska’s works accidentally invalidate them. I suggest a short statement of Marcin Napiórkowski’s and Stephen Marks’ works to show closer (Marks) and further (Napiórkowski) parallels or completely different presentations of similar problems.
This article takes up Adam Dziadek’s somatic approach to literature to explore the theme of erotic experience in two poems by Jarosław Iwaszkiewicz, ‘L’amour Cosaque’ and ‘Amore profane’. With the help of inputs from gender studies and the contemporary theories of the subject it has been possible to profi le the ‘I’ of the poems as a deeply fragmented and sexually ambiguous subject, and, upon the evidence of the elusive autobiographical details woven into the text, as a subject suspended in a liminal space, between the real and the fi ctive world. After analyzing the body represented in the text, both perfect and decrepit, as well as traces of the poet’s carnality that interfere with the text and the reader’s sense of his own soma the article arrives at the following conclusion: in Jarosław Iwaszkiewicz’s lyrics the body seems to project its impressions and experiences onto reality, thus blurring the border between the inside and the outside.
The aim of the paper is to shed light on the theoretical background of the inclusion of health in the standard of living studies, and the use of two of its specifi c measures — life expectancy at birth and body height. Hence, the article describes the idea of capabilities and functionings developed by Amartya Sen as a proposed solution to the limitations of the classic measurement of the standard of living.
Martin Heidegger’s philosophy influenced both psychiatry and practical psychotherapy of mentally disturbed patients. The essay deals with Heidegger’s concepts of corporeality and disease, as they were expounded in the Zollikon seminars, and discusses the influence of Heidegger’s Dasein-analysis on Ludwig Binswanger and Medard Boss. The concepts of Dasein-analysis, proposed by the two psychiatrists, are also discussed. At the end of the paper the author shows the relevance of Heidegger’s thought for psychiatry and psychotherapy in general and for the so-called anthropological psychiatry in particular.