Design, Fabrication, and Experimental Validation of a Warm Hydroforming Test System

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Mevlüt Türköz ◽  
Hüseyin Selçuk Halkacı ◽  
Mehmet Halkacı ◽  
Murat Dilmeç ◽  
Semih Avcı ◽  
...  
Keyword(s):  
Fluid Pressure ◽  
Test System ◽  
Process Window ◽  
Small Scale ◽  
Production Test ◽  
Part Quality ◽  
Heating And Cooling ◽  
Warm Hydroforming ◽  
And Performance ◽  
First Time

In this study, a hydroforming system was designed, built, and experimentally validated to perform lab-scale warm hydromechanical deep drawing (WHDD) tests and small-scale industrial production with all necessary heating, cooling, control and sealing systems. This manuscript describes the detailed design and fabrication stages of a warm hydroforming test and production system for the first time. In addition, performance of each subsystem is validated through repeated production and/or test runs as well as through part quality measurements. The sealing at high temperatures, the proper insulation and isolation of the press frame from the tooling and synchronized control had to be overcome. Furthermore, in the designed system, the flange area can be heated up to 400 °C using induction heaters in the die and blank holders (BH), whereas the punch can be cooled down to temperatures of around 10 °C. Validation and performance tests were performed to characterize the capacity and limits of the system. As a result of these tests, the fluid pressure, the blank holder force (BHF), the punch position and speed were fine-tuned independent of each other and the desired temperature distribution on the sheet metal was obtained by the heating and cooling systems. Thus, an expanded optimal process window was obtained to enable all or either of increased production/test speed, reduced energy usage and time. Consequently, this study is expected to provide other researchers and manufacturers with a set of design and process guidelines to develop similar systems.

PREPARATION, MICROSTRUCTURE AND PERFORMANCE OF NANOSCALE CERAMICS REINFORCED HARD COMPOSITE COATING

2014 ◽  
Vol 21 (01) ◽  
pp. 1450004 ◽  
Author(s):  
PENG LI
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Sliding Wear ◽  
Rapid Heating ◽  
Dry Sliding Wear ◽  
Nanoscale Particles ◽  
Heating And Cooling ◽  
And Performance ◽  
First Time ◽  
Microstructure And Performance

This paper is based on the dry sliding wear of Stellite SF 12- B 4 C - TiN - Mo composite coating deposited on a pure Ti using a laser cladding technique, the parameters of which provide almost crack-free composites with low porosity. To the best of our knowledge, it is the first time that Stellite SF 12- B 4 C - TiN - Mo mixed powders are deposited as the hard composites by a laser cladding technique. Scanning electron microscope images indicate that the nanoscale particles are produced in such coating. The fact that due to the sufficiently rapid heating and cooling rates of the laser cladding technique, the ceramics, such as TiC or TiB 2 did not have enough time to grow up, resulting in the formation of the nanoscale particles. Compared with a pure Ti substrate, the increments of the micro-hardness and wear resistance are obtained for such composite coating.

scholarly journals FCC-ee: the synthesis of a long history of e+e- circular colliders

2021 ◽  
Vol 136 (9) ◽  
Author(s):  
K. Oide ◽  
J. Wenninger
Keyword(s):  
Small Scale ◽  
Vacuum Chambers ◽  
Double Ring ◽  
Electron Positron ◽  
Beam Lifetime ◽  
History Of ◽  
Beam Parameters ◽  
And Performance ◽  
Beam Currents ◽  
First Time

AbstractThe design of FCC-ee is relying on the accumulated experience of $$\mathrm {e^{+}e^{-}}$$ e + e - colliders that have been designed, constructed and operated in the past 40 years. FCC-ee will surpass the 26.7 km long Large Electron Positron collider LEP by a factor 4 in size. Like for LEP the large size is justified by the need to control the synchrotron radiation losses that for both machines reach a few percent per turn. To that end LEP had the first large super-conducting (SC) RF system with around 3.8 GV of accelerating voltage. LEP achieved for the first time very large beam-beam parameters of around 0.08, and it relied on transversely polarized beams to determine accurately the beam energy for the experiments. The DA$$\varPhi $$ Φ NE collider, together with PEP II and KEKB split the two beams into separate vacuum chambers to reach much higher Ampere-level beam currents. To overcome beam-beam lifetime and performance issues DA$$\varPhi $$ Φ NE used for the first time the Crab Waist concept for the interaction region (IR) optics. The B-factories, PEP-II and KEKB have verified the double-ring $$\mathrm {e^{+}e^{-}}$$ e + e - collider with multi-ampere stored currents for over 1000 bunches, small $$\beta ^*$$ β ∗ , top-up injection, and achieved then-highest luminosity. KEKB has applied 22-mrad crossing angle at the IP with crab crossing. Both machines inherited accelerator techniques from their predecessors, PEP and TRISTAN, which was a small-scale LEP. Currently the next generation SuperKEKB collider is starting up. It has already achieved some milestones required for FCC-ee such as small $$\beta ^*$$ β ∗ (0.8 mm) and virtual crab-waist scheme with a large Piwinski angle (>10).

“Little Trio” for clarinet, bassoon and piano

2018 ◽  
pp. 75-79
Author(s):  
N. Yakovchuk
Keyword(s):  
Chamber Music ◽  
Instrumental Music ◽  
Instrumental Ensemble ◽  
Interesting Phenomenon ◽  
Theoretical Understanding ◽  
Classical Traditions ◽  
And Performance ◽  
Instrumental Ensembles ◽  
Written Compositions ◽  
First Time

The chamber-instrumental ensemble music in the Ukrainian musical culture of the last third of the 20th and the beginning of the 21st centuries occupies one of the leading places and is characterized by powerful processes in its development. Such circumstances caused the Ukrainian musicologist interests to the problems of chamber-instrumental music creativity and performance. There are appeared researches in the field of theory, history and performance problems covering the most important questions like chamber music definitions, specific genre issues, the growing function of piano in the Ukrainian chamber music, the increasing questions of technique and timbre importance of modern instrumental ensembles. In the significant multifaceted creative work of contemporary Ukrainian composer, Oleksandr Yakovchuk, the genre of chamber instrumental ensemble music represents a complex and interesting phenomenon. Original and skillfully written compositions reflect artistic world of the composer of postmodern time and gained recognition in music life of Ukraine and beyond. These works are highly appreciated in performing practice of our days. The purpose of the article is to analyze the work — “Little Trio” for clarinet, bassoon and piano (1980), which has the signs of neoclassical tendency in the composer’s style. The methodological basis of this research is a comprehensive approach in theoretical understanding of the subject of research (the methods of textology, source study as well as the method of interviewing the author were used). The scientific novelty of this article is in the priority of its main provisions, since the “Little Trio” entered the scientific circulation for the first time. The three-movement “Little Trio” (1980) is notable for the light feeling of timbre colours and the shape clarity. The Ist movement — Allegretto giocoso — is written in a sonata form following all classical traditions. Quite interesting are the two monologues of clarinet and bassoon from the IInd movement, they represent very modern line in Ukrainian chamber music — the possibility of sincere confession which comes through the solo cadence. In the IIIrd movement, the composer took advantage from the folk Ukrainian dance “hopak” using the rhythm of it and creating dance character of the Final.

The impact of traditional plants and their secondary metabolites in the discovery of COVID-19 treatment

2020 ◽  
Vol 26 ◽  
Author(s):  
Shabana Bibi ◽  
Ayesha Sarfraz ◽  
Ghazala Mustafa ◽  
Zeeshan Ahmed ◽  
Muhammad Aurang Zeb ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Test System ◽  
Chemical Information ◽  
System Type ◽  
The Family ◽  
Comprehensive Search ◽  
Coronavirus Infection ◽  
The Impact ◽  
First Time ◽  
Plant Sources

Background: Coronavirus Disease-2019 belongs to the family of viruses which cause a serious pneumonia along with fever, breathing issues and infection of lungs for the first time in China and later spread worldwide. Objective: Several studies and clinical trials have been conducted to identify potential drugs and vaccines for Coronavirus Disease-2019. The present study listed natural secondary metabolites identified from plant sources with antiviral properties and could be safer and tolerable treatment for Coronavirus Disease-2019. Methods: A comprehensive search on the reported studies was conducted using different search engine such as Google scholar, SciFinder, Sciencedirect, Medline PubMed, and Scopus for the collection of research articles based on plantderived secondary metabolites, herbal extracts, and traditional medicine for coronavirus infections. Results: Status of COVID-19 worldwide and information of important molecular targets involved in COVID-19 is described and through literature search, is highlighted that numerous plant species and their extracts possess antiviral properties and studied with respect to Coronavirus treatments. Chemical information, plant source, test system type with mechanism of action for each secondary metabolite is also mentioned in this review paper. Conclusion: The present review has listed plants that have presented antiviral potential in the previous coronavirus pandemics and their secondary metabolites which could be significant for the development of novel and a safer drug which could prevent and cure coronavirus infection worldwide.

Do Accounting Faculty Characteristics Impact CPA Exam Performance? An Investigation of Nearly 700,000 Examinations

2015 ◽  
Vol 31 (3) ◽  
pp. 291-300 ◽  
Author(s):  
Dennis M. Bline ◽  
Stephen Perreault ◽  
Xiaochuan Zheng
Keyword(s):  
Exam Performance ◽  
Faculty Research ◽  
Pass Rates ◽  
Accounting Faculty ◽  
Research And Teaching ◽  
Faculty Characteristics ◽  
Cpa Exam ◽  
Faculty Research Productivity ◽  
And Performance ◽  
First Time

ABSTRACT While many colleges and universities publicize CPA examination pass rates as evidence of having a high-quality accounting program, some have questioned whether program-specific characteristics are legitimate predictors of examination success. To examine this issue, we empirically investigate the link between accounting faculty characteristics and performance on the CPA examination. We examine the results from nearly 700,000 first-time exam sittings taken during the period 2005–2013 and find that faculty research and teaching specialization has a significant impact on CPA exam performance. That is, when a program has a relatively higher percentage of accounting faculty with expertise in a particular content area tested on the exam (e.g., auditing), graduates achieve higher scores on the related exam section (e.g., AUD). We also find that faculty research productivity and CPA certification status are positively related to candidate exam performance. We believe these results contribute to the existing literature on the determinants of CPA exam success and also provide important insights to those responsible for accounting faculty staffing and development.

Study on Common Ground Testing Platform Technology for Telemetry Core Equipment

2012 ◽  
Vol 220-223 ◽  
pp. 1472-1475
Author(s):  
Qiu Lin Tan ◽  
Xiang Dong Pei ◽  
Si Min Zhu ◽  
Ji Jun Xiong
Keyword(s):  
Data Exchange ◽  
Common Ground ◽  
Digital Signal ◽  
Test System ◽  
Automatic Test System ◽  
Module Design ◽  
The Status ◽  
Output Module ◽  
And Performance ◽  
Hardware Circuit

On the basis of automatic test system of the status in domestic and foreign, by analysis of the various functions and performance of the integrated test system, a design of the integrated test system is proposed, FPGA as the core logic controller of the hardware circuit. The system of the hardware design include: digital signal source output modules, analog output module and PCM codec module. Design of hardware circuit are mainly described. In addition, a detailed analysis of some key technologies in the design process was given. Overall, its data exchange with host computer is through the PCI card, data link and bandwidth can be expanded in accordance with the actual needs. The entire system designed in the modular principle, which has a strong scalability.

scholarly journals QPOs in compact binaries from small scale eruptions in an inner magnetized disk

2020 ◽  
Author(s):  
Nicolas Scepi ◽  
Mitchell C Begelman ◽  
Jason Dexter
Keyword(s):  
Rapid Heating ◽  
Small Scale ◽  
Type B ◽  
Periodic Oscillations ◽  
X Ray ◽  
Compact Binaries ◽  
Heating And Cooling ◽  
Low Mass ◽  
X Ray Binaries ◽  
Standard Disk

Abstract Dwarf novæ (DNe) and low mass X-ray binaries (LMXBs) are compact binaries showing variability on time scales from years to less than seconds. Here, we focus on explaining part of the rapid fluctuations in DNe, following the framework of recent studies on the monthly eruptions of DNe that use a hybrid disk composed of an outer standard disk and an inner magnetized disk. We show that the ionization instability, that is responsible for the monthly eruptions of DNe, is also able to operate in the inner magnetized disk. Given the low density and the fast accretion time scale of the inner magnetized disk, the ionization instability generates small, rapid heating and cooling fronts propagating back and forth in the inner disk. This leads to quasi-periodic oscillations (QPOs) with a period of the order of 1000 s. A strong prediction of our model is that these QPOs can only develop in quiescence or at the beginning/end of an outburst. We propose that these rapid fluctuations might explain a subclass of already observed QPOs in DNe as well as a, still to observe, subclass of QPOs in LMXBs. We also extrapolate to the possibility that the radiation pressure instability might be related to Type B QPOs in LMXBs.

Framework and performance analysis of college English testing system based on data mining technology

2021 ◽  
pp. 1-11
Author(s):  
Liu Narengerile ◽  
Li Di ◽  
Keyword(s):  
Data Mining ◽  
Test System ◽  
Test Time ◽  
Testing System ◽  
Test Results ◽  
System Software ◽  
Examination System ◽  
Mining Technology ◽  
College English ◽  
And Performance

At present, the college English testing system has become an indispensable system in many universities. However, the English test system is not highly humanized due to problems such as unreasonable framework structure. This paper combines data mining technology to build a college English test framework. The college English test system software based on data mining mainly realizes the computer program to automatically generate test papers, set the test time to automatically judge the test takers’ test results, and give out results on the spot. The test takers log in to complete the test through the test system software. The examination system software solves the functions of printing test papers, arranging invigilation classrooms, invigilating teachers, invigilating process, collecting test papers, scoring and analyzing test papers in traditional examinations. Finally, this paper analyzes the performance of this paper through experimental research. The research results show that the system constructed in this paper has certain practical effects.

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