Thermal lattice Boltzmann simulations of variable Prandtl number turbulent flow

With the advent of massively parallel processor machines, thermal lattice Boltzmann equation (TLBE) techniques offer an attractive way of handling turbulence simulations. TLBE is new form of DNS (direct numerical simulation method)--with the important advantages of being ideal for multi-parallel processors as well as being able to handle complicated geometries. Since there are many kinetic models that will reproduce the macroscopic nonlinear (compressible) transport equations, TLBE chooses that subset which can be readily solved on a discrete spatial lattice. The lattice geometry must be so chosen that the discrete phase representation of TLBE will not taint the rotational symmetric continuum equations. For 2D compressible flows, linear stability analyses described in this work indicates that the hexagonal lattice is optimum.;In nearly all lattice Boltzmann literature, the linearized Boltzmann collision operator has been taken to be the simple single-time Krook relaxation collision operator. This scalar collision operator is sufficient to recover the nonlinear transport equations under Chapmann-Enskog expansions. However, all previous LBE have suffered from the problem of density dependent transport coefficients. Even though this poses no problem for incompressible flows, it is critical and must be handled for compressible fluid simulations. The other deficiency of conventional TLBE scheme with single relaxation operator is that it only allows for fixed Prandtl number flow simulations.;In this work, to simulate flows with arbitrary Prandtl number, a matrix collision operator is introduced. With the inclusion of additional free parameter in the off-diagonal components, the scheme is now extended to a multi-relaxation process. This allows generalizations on relaxation parameters to produce density independent transport coefficients. Explicit solutions of TLBE are presented for 2D free decaying turbulence

Analysis on Performance of DC Microgrid under Fault Condition

DC Microgrid is the high quality electric power by using DC distribution focused on the development of renewable energy resources such as photovoltaic cells, wind turbines, fuel cells and etc. In this system, DC grid is connected to the AC utility grid through AC/DC rectifier and several distributed generations are connected to DC line through converters in order to improve the reliability of the power system. Most of the faults cause on overhead lines of power system. When a fault occur on a power system, it is very important to check quickly, to detect it, to find its definite location and to restore power system as soon as possible. In this paper, the configurations of DC microgrid system and control methods of distributed generation are expressed. Moreover, fault on source side, fault on load side and fault on DC transmission line are analyzed. Faults are shown single line to ground fault for generation side and load side and line to line fault for DC transmission side. In order to identify the various faults characteristics of DC Microgrid, simulation results are performed with Matlab/ Simulink Software

Earthquakes and slip rate of the southern Sagaing fault: insights from an offset ancient fort wall, lower Burma (Myanmar)

Field investigations of an ancient fortress wall in southern Myanmar reveal an offset of ~6 m across the Sagaing fault, the major right-lateral fault between the Sunda and Burma plates. The fault slip rate implied by offset of this 16th-century fortress is between 11 and 18 cm yr^(–1). A palaeoseismological excavation within the fortress reveals at least two major fault ruptures since its construction. The slip rate we obtained is comparable to geodetic and geological estimates farther north, but is only 50 per cent of the spreading rate (38 mm yr^(–1)) at the Andaman Sea spreading centre. This disparity suggests that other structures may be accommodating deformation within the Burma Plate. We propose two fault-slip scenarios to explain the earthquake-rupture history of the southern Sagaing fault. Using both small offset features along the fault trace and historical records, we speculate that the southern Sagaing fault exhibits a uniform-fault-slip behaviour and that one section of the fault could generate a M7+ earthquake within the next few decade

A Systematic Review on the Effectiveness of Different Functional Treatments for Acute Ankle Sprains

Background: An ankle sprain is a very common sport-related injury and can reduce participation in sports and employment. It can also create further complications in the function of the joint. Purpose: To evaluate the effectiveness of different functional treatments and to ascertain which functional treatment is the most effective method for acute ankle sprains. Study Design: Systematic review. Methods: The design of this systematic review was developed in accordance with PRISMA-P 2015 statement and performed according to its guidelines. A computerized literature search was performed from PubMed Central, MEDLINE via OVID and Cochrane library. Randomized controlled trials or quasi-experimental studies, published within a ten-year period (2007 to 2017), in peer-reviewed journals, with full-text articles and written in English were included in this study. Any type of functional treatments being applied to treat acute ankle sprains were considered as an intervention and only adult participants were included in this review. Surgical methods, unpublished trials, not written in the English language or not experimental research were excluded. Results: From the pooled data of this review, the stocking was more effective at improving pain, swelling, functional outcomes, range of motion, and return to sport/work, and had higher patient satisfaction than the bandage. There was no evidence that the taping and lace-up brace were more effective than other functional interventions in the treatment of acute ankle sprains. Furthermore, the prevalence of complications was greatest for the taping and lace-up brace interventions. The semi-rigid or posterior rigid support group had a better functional recovery and higher patient satisfaction, but some complications were present. Conclusion: The semi-rigid or posterior rigid support group and stocking were the most effective functional interventions for acute ankle sprain treatment. What is known about this subject: The functional treatments are becoming popular due to being effective, inexpensive and simplistic to apply. Different types of functional interventions have been used according to the choice of clinicians and patients in the treatment of ankle sprains. According to the previous researches, semi-rigid support, ankle braces, bandage and lace-up supports have greater advantages than other functional treatments from different perspectives (Example. the elastic bandage had a slower recovery rate than semi-rigid brace but less complications than taping, the lace-up support was better in swelling management than other functional treatments). What this study adds to existing knowledge: This study found that the stocking is an effective treatment for managing acute ankle sprains. It is valuable for the patient because the cost of the stocking is considerably cheaper than other functional treatments and it is very easy to wear. Some popular functional treatments like lace-up support; taping and semi-rigid braces were shown to have some complications

ミャンマー・ヤンゴン市におけるデング3型ウイルス(DENV-3)遺伝子型Iの出現に伴うDENV-3症例の増加、2017年－2019年

長崎大学学位論文 [学位記番号]博（医歯薬）甲第1369号 [学位授与年月日]令和3年9月17

Searching for the 1912 Maymyo earthquake:new evidence from paleoseismic investigations along the Kyaukkyan Fault, Myanmar

The Great Burma earthquake (MsGR 8.0; Ms 7.6–7.7) occurred on May 23rd, 1912, and was one of the most remarkable early 1900's seismic events in Asia as described by Gutenberg and Richter (1954). The earthquake, focused near Maymyo, struck the Northern Shan State in eastern Myanmar. Contemporary evaluation of damage distribution and oral accounts led to a correlation between the earthquake and the topographically prominent Kyaukkyan Fault near the western margin of the Shan Plateau, although direct evidence has never been reported. This study aims to find evidence of paleoseismic activity, and to better understand the relationship between the 1912 earthquake and the Kyaukkyan Fault. Paleoseismic trenching along the Kyaukkyan Fault revealed evidence of several surface rupturing events. The northernmost trench exposes at least two visible rupture events since 4660 ± 30 BP: an older rupture stratigraphically constrained by AMS 14C dating to between 4660 ± 30 BP and 1270 ± 30 BP, and a younger rupture formed after 1270 ± 30 BP. The presence of pottery, bricks and cookingrelated charcoal in the younger faulted stratigraphy demonstrates Kyaukkyan Fault activity within human times, and a possible correlation between the younger rupture and the 1912 Maymyo earthquake is not excluded. The southern paleoseismic trench, within a broad transtensional basin far from bounding faults, exposes two (undated) surface ruptures. Further study is required to correlate those ruptures to the events dated in the north. These preliminary paleoseismological results constitute the first quantitative evidence of paleoseismic activity along the northern ~160 km of the Kyaukkyan Fault, and support existing evidence that the Kyaukkyan Fault is an active but slow-slipping structure with a long interseismic period.Published75-862T. Deformazione crostale attivaJCR Journa