Port Opening Research Articles

Kinematics of an Articulated Connecting Rod and Its Effect on Simulated Compression Pressures and Port Timings

This study discusses the motion of the articulated connecting rod of an integral-engine compressor and the effect of the kinematics on in-cylinder pressure and port timings. A piston position modeling technique based on kinematics and engine geometry is proposed in order to improve the accuracy of simulated in-cylinder compression pressures. Many integral-engine compressors operate with an articulated connecting rod. For this type of engine-driven compressor, two power pistons share a crank throw with the compressor. The hinge pins that attach the power piston connecting rods to the crank are offset, causing the piston locations for each cylinder to be out of phase with each other. This causes top dead center (TDC) to occur at different crank angles, alters the geometric compression ratio, and also changes the port timings for each cylinder. In this study, the equations of motion for the pistons of the four possible compressor/piston configurations of a Cooper-Bessemer GMW are developed. With the piston profiles, the intake and exhaust port timings were determined and compared to those of a slider-crank mechanism. The piston profile was then inputted into GT-POWER, an engine modeling software developed by Gamma Technologies, in order to obtain an accurate simulation match to the experimental in-cylinder pressure data collected from a Cooper-Bessemer GMWH-10C. Assuming the piston motion of an engine with an articulated connecting rod is similar to a slider-crank mechanism can create a difference in port timings. The hinge pin offset creates asymmetrical motion about 180°aTDC, causing the port timings to also be asymmetrical about this location. The largest differences are shown in the intake port opening of about 10 deg and a difference in exhaust port opening of about 7 deg when comparing the motion of the correct configuration to the motion of a slider-crank mechanism. It is shown that properly calculating the piston motion profiles according to the crank articulation and engine geometry provides a good method of simulating in-cylinder pressure data during the compression stroke.

Numerical Modeling of a Wave Turbine and Estimation of Shaft Work

Wave rotors are periodic-flow devices that provide dynamic pressure exchange and efficient energy transfer through internal pressure waves generated due to fast opening and closing of ports. Wave turbines are wave rotors with curved channels that can produce shaft work through change of angular momentum from inlet to exit. In the present work, conservation equations with averaging in the transverse directions are derived for wave turbines, and quasi-one-dimensional model for axial-channel non-steady flow is extended to account for blade curvature effects. The importance of inlet incidence is explained and the duct angle is optimized to minimize incidence loss for a particular boundary condition. Two different techniques are presented for estimating the work transfer between the gas and rotor due to flow turning, based on conservation of angular momentum and of energy. The use of two different methods to estimate the shaft work provides confidence in reporting of work output and confirms internal consistency of the model while it awaits experimental data for validation. The extended wave turbine model is used to simulate the flow in a three-port wave rotor. The work output is calculated for blades with varying curvature, including the straight axial channel as a reference case. The dimensional shaft work is reported for the idealized situation where all loss-generating mechanisms except flow incidence are absent, thus excluding leakage, heat transfer, friction, port opening time, and windage losses. The model developed in the current work can be used to determine the optimal wave turbine designs for experimental investment.

A Study on the Adoption of ‘Higher Education’ during the Early Opening Port Era in Korea(1876-1894)

A Study on the Adoption of ‘Higher Education’ during the Early Opening Port Era in Korea(1876-1894)

A small three-way valve using particle excitation with piezoelectric transducers for hydraulic actuators

Robots composed of hydraulic actuators have been utilized in various fields and at disaster sites. However, the hydraulic control system for multiple-degree-of-freedom mechanisms is large because such systems require many control components. The purpose of this research was to develop a small hydraulic flow control valve. This paper describes the fabrication and evaluation of a small three-way valve by particle excitation using a piezoelectric transducer. This valve consists of two transducers and can switch the inlet and outlet ports by applying an AC voltage of different driving frequencies to each transducer because each transducer has different resonant frequencies. The flow rate was controlled by applying a voltage to the piezoelectric transducer. We evaluated the vibration characteristics of the fabricated three-way valve. The vibration velocity exhibited peaks at 120 and 155 kHz for the inlet and outlet port, respectively, and that of each transducer increased with the applied voltage. Therefore, this three-way valve can switch the opening port by changing the driving frequencies and continuously controlling the flow rate. As a result, we have succeeded in driving the novel small three-way valve.

개항기 한글신문의 평등개념 연구 : 『독립신문』과『제국신문』을 중심으로

개항기 한글신문의 평등개념 연구 : 『독립신문』과『제국신문』을 중심으로

Radiation shielding calculations for a 3D ITER benchmark model using TRIPOLI-4® Monte Carlo code

The International Thermonuclear Experimental Reactor (ITER) is currently under construction in France. From the radiation shielding and radiation protection points of view, an intense and large neutron source with energy around 14.1 MeV will be generated from the D-T plasma zone during the ITER operation and diverse gamma-ray sources from neutron activation of the reactor structure materials and coolant should be considered for the reactor operation and maintenance. To decrease the radiation impacts caused by these neutron and gamma sources, iterative designs and nuclear analyses of ITER components are currently performed with three dimensional Monte Carlo radiation transport calculations. Due to the important dimensions of ITER, the thick tokamak blanket modules, and the diagnostic and functional port openings, variance reduction techniques are essential in these Monte Carlo neutron transport calculations. To verify the reactor components design models and to check the radiation transport calculation results, advanced graphic features of the calculation tool are also necessary. With the growing interest in using the TRIPOLI-4® Monte Carlo radiation transport code for ITER applications, the aim of this paper is to study the feasibility to use variance reduction features of TRIPOLI-4 code on a 3D ITER benchmark model which is a 40° toroidal segment including 5796 vol cells. The calculation results reported in this paper include the axial and radial profiles of the inboard TF coil heating and the neutron flux attenuation through the equatorial port plugs and shield. The performance of the TRIPOLI-4 graphic tool under its parallel computing mode was also evaluated.

The economic, social, and environmental impacts of cruise tourism

We use a unique multi-method natural experiment to measure economic, social, and environmental impacts of cruise tourism on a local community. Through the measurement of multidimensional indicators before and after the opening of a cruise ship port, and using control groups, we compare community impacts with greater detail and control than previous studies. Although theory and industry multiplier estimates predict gains in employment, income, and related measures, we find little evidence of improvement. The ability of the local population to provide for necessities and obtain sufficient food worsened, corruption increased, and there were substantial negative environmental impacts. One observed benefit to communities was a decrease in crime due to an increase in government expenditure on policing. Our results show that in low taxation and regulation environments with an absence of community development and involvement initiatives, large cruise tourism projects can fail to provide benefits for local populations.

Would “suction above cuff” be a better option than the “standard” endotracheal tube for the prevention of ventilator-associated pneumonia: A randomized study in postoperative neurological patients

Context:Ventilator associated pneumonia is one the most common nosocomial infection encountered in the ICU patients. Despite of the implementation of the VAP prevention bundle, the incidence remains high. This can be attributed to the peritubal leak and the aspiration of the oropharyngeal secretions. The secretions further forms a nidus for the growth of organisms in the lower respiratory tract. In this study, a specialised tube, named ‘suction above cuff endotracheal tube’ is used, which has an additional suction port opening above the cuff. This is to facilitate timely aspiration of the secretion which pent-up above the cuff and gradually trickles down the trachea resulting in pneumonia.Aim:to compare the incidence of VAP with standard endotracheal tube (SETT) and suction above cuff endotracheal tube (SACETT) in neurological post-operative patients and its impact on clinical outcome.Settings and Design:60 patients of post-operative neurological cases aged ≥ 18 years and requiring intubation and/or ventilation and anticipated to remain on ETT for ≥48 h were randomized to receive either SETT or SACETT.Results:In this study involving neurological population, there was no significant difference in incidence of clinical and microbiological VAP between SETT and SACETT group, when other strategies for VAP prevention were similar. Other outcomes were similar with use of either tube for intubation.

Erosion degradation characteristics of a linear electro-hydrostatic actuator under a high-frequency turbulent flow field

The paper proposes a performance degradation analysis model based on dynamic erosion wear for a novel Linear Electro-Hydrostatic Actuator (LEHA). Rather than the traditional statistical methods based on degradation data, the method proposed in this paper firstly analyzes the dominant progressive failure mode of the LEHA based on the working principle and working conditions of the LEHA. The Computational Fluid Dynamics (CFD) method, combining the turbulent theory and the micro erosion principle, is used to establish an erosion model of the rectification mechanism. The erosion rates for different port openings, under a time-varying flow field, are obtained. The piecewise linearization method is applied to update the concentration of contaminated particles within the LEHA, in order to gain insight into the erosion degradation process at various stages of degradation. The main contribution of the proposed model is the application of the dynamic concentration of contamination particles in erosion analysis of Electro-Hydraulic Servo Valves (EHSVs), throttle valves, spool valves, and needle valves. The effects of system parameters and working conditions on component wear are analyzed by simulations. The results of the proposed model match the expected degradation process.

The birth of modern fashion in Korea: Sartorial transition between hanbok and yangbok through production, mediation and consumption

Abstract Sartorial change from hanbok (Korean dress) to yangbok (western dress) is commonly seen as marking the transitional Opening Port era of the late nineteenth century, when modern fashion emerged, seemingly replacing ‘traditional’ Korean dress with ‘modern’ western dress. However, when examining actual cases of Korean sartorial practice, this linear and dichotomous framework – non-western traditional versus western modern – has limits in its approach, lacking the multiplicity of local meanings and experiences in line with particular social and cultural contexts. This study instead explores the protean transition of dress and fashion in Korea as a way of challenging Eurocentric notions of fashion. In particular, it seeks a better understanding of the sartorial transition and local practice of modern dress and fashion emerging in colonial modern Korea through production, mediation and consumption. Critically reinterpreting diverse sources of object, image and text gleaned from the modern colonial period (1910–45), the framework of production–mediation–consumption builds up a rounded picture of the emergence of modern Korean dress and fashion that materialized through not only yangbok but also hanbok. Reflecting modern ironies of the time and the specificities of colonial society, the dichotomy between the two dress systems (hanbok and yangbok) was rather nuanced, multifaceted and intricately developed in relation to modern fashion, local modernities and the ways in which they evolved in the vernacular Korean context, across colonial and western fashion discourses.

Articulatory correlates of phonemic and coarticulatory nasalization

Phonological theory distinguishes nasal and oral vowel counterparts by velopharyngeal port opening, neglecting other phonetic differences between phonemic and coarticulatory nasalization. Recent articulatory work provides evidence of oropharyngeal distinctions, in addition to velic lowering. This study (12 Brazilian Portuguese speakers) uses real-time MRI to investigate oropharyngeal differences between oral, phonemically nasal, and phonetically nasalized vowels /a, i, u/. Tissue boundaries in midsagittal vocal tract images were automatically detected to reveal each vowel repetition’s aperture function. Principal Components Analysis determined vocal tract regions responsible for the greatest variance in the data. Time-dynamic analyses of vocal tract area in these regions used smoothing spline ANOVA. Results show the tongue body and/or hyperpharynx as the most important articulators. For /a/, nasal vowels demonstrate wider hyperpharyngeal and narrower tongue body regions compared to oral vowels. For /u/, o...

Analysis of scavenge port designs and exhaust valve profiles on the in-cylinder flow and scavenging performance in a two-stroke boosted uniflow scavenged direct injection gasoline engine

In this study, effects of intake scavenge port designs and exhaust valve opening profiles were studied on the scavenging process in a newly proposed two-stroke boosted uniflow scavenged direct injection gasoline engine by detailed three-dimensional engine simulations. As the most important geometric parameters, the axis inclination angle and swirl orientation angle of scavenge ports, as shown in Figure 1, were investigated and optimized for best scavenging performances at first. With the optimal axis inclination angle of 90° and swirl orientation angle of 20°, various combinations of scavenge port opening timing, exhaust valve opening duration and exhaust valve opening timing were then analysed. Four distinct scavenging periods, that is, early backflow period, backflow scavenging period, main scavenging period and post backflow period, were identified and their impacts on the in-cylinder flow motions and scavenging performances were investigated. The results show that the optimal scavenging performance can be achieved with a higher delivery ratio, charging efficiency and scavenging efficiency when the post backflow is just avoided by tuning the difference between the closing timings of scavenge ports and exhaust valves (Δ close) and the overlap between the opening profiles of scavenge ports and exhaust valves (Δ overlap) for a specific exhaust valve opening duration. A longer exhaust valve opening duration can be used to further improve the scavenging performances. In addition, the difference between the opening timings of scavenge ports and exhaust valves (Δ open) can be increased to improve scavenging efficiency. The Δ close also shows strong positive correlation with in-cylinder swirl ratio and negative correlation with tumble ratio. The results presented in this study provide the fundamental knowledge of the scavenging process in the uniflow scavenged two-stroke engine and assist the design of scavenge ports and valve strategies to optimize in-cylinder flow motion and scavenge performances in the two-stroke boosted uniflow scavenged direct injection gasoline engine with a variable valve actuation system for exhaust valves.

開港期의 會社制度 硏究

開港期의 會社制度 硏究

A study on the vest shape and tailoring of the Korean Empire in the 1900s

The purpose of this study is to fundamentally examine the vests of the robes “Daeraebok” and “Soraebok” of the Korean Empire from the 1876 Port Opening to the 1910 annexation of Korea to Japan. Among the collections of different robes of the Korean Empire which belong to various universities and institutions, only the vests were surveyed. The shape of the vests in the Korean Empire were single-breasted and doublebreasted. Most V-necklines and vests with a shawl collar look like a tailored collar, where the collar outline was shaped like a notched and picked collar, which is a mix of the step collar and roll collar of the 19th century. The rear center line was not flat, but inclined to a triangle. All vests of the robe Daeraebok were equipped with gold buttons, and those of the robe Soraebok had black satin buttons. The tailoring characteristic is that the front has a different material (dark black wool) from the back (black silk). This characteristic is expected to be an important basic piece of information in the restoration and reproduction of the vest, which was worn during the imperial period, especially to reveal its shape, characteristics and composition. This characteristic can also be used as data of cultural contents based on Korean modern history.

Study on “Industry of Joseon”, a Japanese Magazine Published in Busan during the Port Opening Period

Study on “Industry of Joseon”, a Japanese Magazine Published in Busan during the Port Opening Period

ADITYA upgrade vacuum vessel: Design, construction, testing, installation and operation

Limiter based ADITYA tokamak has been upgraded in the divertor configured ADITYA-U tokamak. The ADITYA tokamak upgradation includes the replacement of rectangular cross section vacuum vessel by circular cross section vacuum vessel to accommodate additional poloidal (divertor) coils in space between the new vessel and toroidal field coils. The major radius (0.75m) and minor radius (0.25m) has been kept same as of old torus so as to accommodate the new torus inside the toroidal field coils. In order to accommodate as many numbers of diagnostics as possible, the ADITYA-U vessel is designed to have 111 port openings directly on the vessel. The leak proof, UHV condition, precise dimensions and lots of weld and demountable joints in the new vessel made the fabrication job very challenging. The ADITYA-U vacuum vessel of SS304L has been precisely fabricated as per IPR design by Godrej & Boyce Mfg. Co. Ltd. under the supervision of IPR scientists. The factory and IPR site acceptance tests of new vessel had been completed successfully, such as dimensional measurement, leak test, pressure, baking. The final acceptable tests had been carried out successfully as results of local leak rate <5×10−10mbarl/s and global leak rate <5×10−8mbar.l/s, UHV test as <10−9mbar, vessel baking >150°C. After external testing, the vessel has been installed successfully in ADITYA-U tokamak structure. In this paper, we present the all details of ADITYA-U vacuum vessel like design, analysis, fabrication, acceptance, installation and operation to ascertain its suitability for the plasma experiments.

Acceptance and Development of Western Agriculture after Opening of Port

Acceptance and Development of Western Agriculture after Opening of Port

Erosion of installations in ports of a fusion reactor by hot fuel atoms

Charge-exchange interactions between plasma ions and neutrals, recycling from the first wall of a fusion reactor, generate c-x atoms of high energy. These may get into openings of diagnostic ports in the wall, leading to enhanced erosion of installations there, e.g., first mirrors. The energetic spectra of c-x atoms are modeled with the plasma density, electron and ion temperatures varying across the flux surfaces and by taking into account the inhomogeneity of the neutral density along the surfaces due to the absence of recycling at the opening position. The rate of erosion caused by physical sputtering with hot atoms on installations inside the port is computed for the plasma conditions expected in the DEMO fusion reactor, for several fusion relevant materials (beryllium, iron, molybdenum and tungsten), versus the port opening radius and clearance to the installation surface.

개항기 경상도관찰사 이헌영과 달성향약

개항기 경상도관찰사 이헌영과 달성향약

O PORTO DO PECÉM – CE E AS SUAS RELAÇÕES COM O BRASIL: DEFINIÇÃO DE UMA HINTERLÂNDIA

doi: 10.12957/geouerj.2016.15969 This article analysis the relationship between the Pecem Port and Brazil, from a logical of flows. To note that Pecem’s Port, 60 kms from Fortaleza, the state capital, was built to integrate the Industrial and Port Complex, which is still in installation. With this temporal mismatch between the port's opening in 2002 and the construction of anchor industries, the Pecem Port sought to expand its structure allowing the export and import of other commodities. With its proximity to the United States and Europe, the Pecem port has been a response to a wide range of municipalities. This article intend to present the development of port systems, Pecem’s Port and especially define its hinterland, ie, what is your real influence area.