Failure Analysis of Variably Sized 4340 Steel Mandrels Utilized in the Production of Seamless Superalloy Rings through the Vertical Ring Rolling Process

Vertical ring rolling is a forging process which forms seamless metal rings through applying a large force at elevated temperatures onto component materials stabilized by cylindrical mandrels. Carlton Forge Works, a company which produces rings of superalloy materials such as INCO718 and 718Plus, is experiencing a consistent failure of mandrels due to extreme conditions. An analysis of the lifetime (bulk material, heat treatment, and use) was performed, which aided in the identification of process variables tied to mandrel failure. Experiments were formed surrounding three variables of the mandrel heat treatment: Austenitization temperature, quenching temperature, and tempering conditions, with the goal of analyzing the degradation of mandrels prior to failure with hardness measurements. Rockwell Hardness C (HRC) was used in each of the three experiments. The first experiment assessed incomplete austenitization due to overcrowded furnaces at 1400˚F and 1550˚F. Secondly, quenching for 10 minutes at 70˚F, 100˚F and 150˚F, was performed to simulate quench vat conditions. Finally, extra tempering at 300˚F, 400˚F, 500˚F, 570˚F, 700˚F, 900˚F and 1400˚F was performed to replicate over-tempering of the mandrels during rolling. Hardness degradation below the HRC range of superalloy rings (35-40 HRC) was used to numerically fit the lifetime of components and propose solutions for mandrel failure

Тестирование скрытых дефектов в соединениях

Electronic instrumentation has a constant growth density layout and functionality. This entails an increase in the density of interconnection elements by increasing their number and reducing the size of it. The growing cost of interconnection structures (printed circuit boards, printing and wired mounting) associated with their complexity and increase of their reliability requirements, result in the search of new and improved non-destructive diagnostic methods and means of control. However, the existing methods do not allow control interconnects with sufficient certainty to identify a significant number of hidden defects. This class of defects can be diagnosed by means of non-destructive testing of interconnections, based on the detection of controlled circuit reaction to a current. The paper describes the principles for calculating the current to exercise that control.Электронное приборостроение находится в состоянии постоянного роста плотности компоновки и функциональности. Это влечет за собой рост плотности элементов межсоединений за счет увеличения их количества и уменьшения размеров. Возрастание стоимости конструкций межсоединений (печатных плат, печатного и проводного монтажа), связанное с их усложнением и возрастанием требований к надежности, обуславливает поиск новых и совершенствование существующих неразрушающих диагностических методов и средств контроля. Однако, существующие методы контроля межсоединений не позволяют с достаточной достоверностью выявить значительную часть скрытых дефектов. Такие дефекты могут быть диагностированы при помощи неразрушающего контроля соединений, основанного на регистрации реакции контролируемых цепей на воздействие импульса тока. В статье описываются принципы расчета параметров импульса тока и способ реализации такого контроля

Globální letecké aliance: vliv spolupráce na individuální výkon aerolinií

In recent years such constellations, like global aviation alliances were formed and they have been developing a lot. They heavily affect the airline market. Using the data from annual reports of 11 different airlines on operational and financial performances, I run a panel data model. The main objective is to understand the effect of global aviation alliance membership on the performance of airlines - revenue and passenger flow in particular. Using different methods and models, such as fixed effects and first differences based on panel data I was not able to document a significant result. Therefore, I could not conclude that it is either beneficial or not in terms of revenue and amount of passengers for airlines to enter an alliance. However, it is not the only thing to take into account and there is more to be researched in this industry, as well as a possibility to improve this research

Globální letecké aliance: vliv spolupráce na individuální výkon aerolinií

V posledních letech konstelace, jako jsou globální letecké aliance, vznikaly a byly výrazně rozvíjeny. Trh leteckých společností je jimi silně ovlivněn. S pomocí dat z výročních zpráv 11 různých leteckých společností z hlediska provozních a finančních výkonů představuji model panelových údajů. Hlavním cílem je pochopení dopadu členství v globální letecké alianci na výkon aerolinií s důrazem na výnosy a cirkulaci cestujících. Za použití různých metod a modelů, jako jsou například neměnné vlivy a prvotní rozdíly založené na panelových údajích, jsem nebyl schopen zaznamenat jednoznačný výsledek. Z tohoto důvodu nemohu v závěru říci, jestli je pro aerolinie vstup do aliance z hlediska výnosů a počtu pasažérů prospěšný, nebo neprospěšný. Nicméně nejedná se o jediné měřítko, které je potřeba brát v úvahu. Existuje mnoho dalších bodů, které by měly být v rámci tohoto odvětví průmyslu zkoumány, stejně jako tu jsou možnosti pro zdokonalení tohoto výzkumu.In recent years such constellations, like global aviation alliances were formed and they have been developing a lot. They heavily affect the airline market. Using the data from annual reports of 11 different airlines on operational and financial performances, I run a panel data model. The main objective is to understand the effect of global aviation alliance membership on the performance of airlines - revenue and passenger flow in particular. Using different methods and models, such as fixed effects and first differences based on panel data I was not able to document a significant result. Therefore, I could not conclude that it is either beneficial or not in terms of revenue and amount of passengers for airlines to enter an alliance. However, it is not the only thing to take into account and there is more to be researched in this industry, as well as a possibility to improve this research

1 GSPS digitizer based on the FPGA Mezzanine Card (FMC) standard with low-count pin connector.

Under the scope of a CERN summer student project, the schematic for ADC based on FMC mezzanine card with 1 GSPS sampling rate and 8 bit resolution was developed. The mezzanine is fully compatible with the standard: FPGA Mezzanine Card (FMC) [1]. A low-pin count connector was used to connect the mezzanine with the “carrier”. The carrier was an Open Hardware project: Simple PCIe FMC carrier (SPEC)

Economic Theoretical and Legal Issues of Antimonopoly Regulation in the Russian Electric Power Industry

The paper discusses the antimonopoly regulation of the Russian wholesale electricity and capacity market as an interconnection of economic theory and legal science. Research of results and by-effects of different regulation mechanisms and understanding the public danger of abusing monopoly power are problems of the economic theory and there are serious contradictions in these spheres nowadays. The legal science reflects these contradictions and transfers them into legal acts. The three legal acts that regulate pricing and bidding in the wholesale electricity and capacity market in Russia are analyzed. Findings show that the concepts of price manipulation and monopolistically high and low pricing are not clearly defined and allow violent interpretation

Specific features of genitourinary trichomoniasis clinical picture and improvement of diagnosis and treatment (clinical and experimental study)

Available from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio