Search query: vacuum pressure control semiconductor device

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abstract: At low pressure, cold plasmas are used for a wide range of applications such as coating, flow control, or microelectronics. Currently, this industry requires expensive vacuum systems which consume energy and time, and therefore it is very appealing to develop similar processes at atmospheric pressure. Under this condition, dielectric barrier discharge (DBD) is one of the best ways to obtain a cold plasma. The dielectric barriers naturally limit the current, and then the plasma temperature. Unfortunately, at atmospheric pressure the discharge ignition between the electrodes requires high voltage, which is generally obtained through a step up transformer. The parasitic elements of this device exclude a smart control for the discharge. In order to overcome this default, we analyze the performance of a transformerless power supply developed with a recently released single chip high voltage semiconductor. The circuit uses only two high voltage switches synthesized by means of the 10 kV SiC MOSFET (Metal Oxide Semiconductor Field Effect Transistor) The design and implementation of the electric converter are presented and validated with experiments carried out on UV excimer DBD lamps. Then, the performances of the 10 kV SiC switches are analyzed and the relevance of this device for DBD applications is discussed.
author_names: Mame Andallah Diop

Antoine Belinger

Hubert Piquet
title: 10 kV SiC MOSFET Evaluation for Dielectric Barrier Discharge Transformerless Power Supply
year: 2020

author_names: O G Korol'

Boris Volodimirovich Klimenko

Oleksandr V'iacheslavovich Ieres'ko
title: Investigations of transients in the novel semiconductor device of forced control of the vacuum contactor monostable electromagnet
venue: Bulletin of NTU "KhPI" Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice
year: 2019

abstract: We describe an easy to assemble and robust design of a ConFlat (CF) iris diaphragm device installed in a vacuum environment with its aperture size directly adjustable by users outside the vacuum. This design involves commercially available vacuum equipment, 3D printed but vacuum compatible components and a minimal need of professional machining to be straightforwardly taken advantage by a wide range of research groups. The iris diaphragm is centered in a 4.5 in. o.d. double sided CF flange with user customizable mounting orientation to allow a maximum range of aperture opening from 0.5 mm to 15 mm in diameter. Installation of this device does not require an additional pump for differential pumping across the iris diaphragm. The functionality of this device is examined at a pressure of ~7 x10 9 Torr to provide continuous control on the cross section of a light beam passed through the aperture.We describe an easy to assemble and robust design of a ConFlat (CF) iris diaphragm device installed in a vacuum environment with its aperture size directly adjustable by users outside the vacuum. This design involves commercially available vacuum equipment, 3D printed but vacuum compatible components and a minimal need of professional machining to be straightforwardly taken advantage by a wide range of research groups. The iris diaphragm is centered in a 4.5 in. o.d. double sided CF flange with user customizable mounting orientation to allow a maximum range of aperture opening from 0.5 mm to 15 mm in diameter. Installation of this device does not require an additional pump for differential pumping across the iris diaphragm. The functionality of this device is examined at a pressure of ~7 x10 9 Torr to provide continuous control on the cross section of a light beam passed through the aperture.
author_names: Yi Chi Zhang

David Y Lee
title: A ConFlat iris diaphragm device for direct beam control and alignment inside a vacuum chamber
venue: AIP Advances
year: 2019

abstract: We present a novel and compact design of a constant pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular, the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, in which efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hectopascals. The CPI device can also be used in condensation particle counters (CPCs) cloud condensation nucleus counters (CCNCs) and gas phase sampling instruments across a wide range of altitudes and inlet pressures. The constant pressure is achieved by changing the inner diameter of a properly scaled O ring that acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate 0.1 L min 1) upstream of an aerodynamic lens constant, deviating at most by only 2 from a preset value. In our setup, a pressure sensor downstream of the O ring maintains control of the pinch mechanism via a feedback loop and setpoint conditions are reached within seconds. The device was implemented in a few instruments, which were successfully operated on different research aircraft covering a wide range of ambient pressures, from sea level up to about 55 hPa. Details of operation and the quality of aerosol particle transmission were evaluated by laboratory experiments and in flight data with a single particle mass spectrometer.
author_names: Sergej Molleker

Frank Helleis

Thomas Klimach

Oliver Appel

Hans-Christian Clemen

Antonis Dragoneas

Christian Gurk

Andreas Hunig

Franziska Kollner

F Rubach

Christiane Schulz

Johannes Schneider

Stephan Borrmann
title: Application of an O ring pinch device as a constant pressure inlet (CPI) for airborne sampling
year: 2020

abstract: Abstract. We present a novel and compact design of a constant pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular, the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, in which efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hectopascals. The CPI device can also be used in condensation particle counters (CPCs) cloud condensation nucleus counters (CCNCs) and gas phase sampling instruments across a wide range of altitudes and inlet pressures. The constant pressure is achieved by changing the inner diameter of a properly scaled O ring that acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate 0.1 L min 1 upstream of an aerodynamic lens constant, deviating at most by only 2 from a preset value. In our setup, a pressure sensor downstream of the O ring maintains control of the pinch mechanism via a feedback loop and setpoint conditions are reached within seconds. The device was implemented in a few instruments, which were successfully operated on different research aircraft covering a wide range of ambient pressures, from sea level up to about 55 hPa. Details of operation and the quality of aerosol particle transmission were evaluated by laboratory experiments and in flight data with a single particle mass spectrometer.
author_names: Sergej Molleker

Frank Helleis

Thomas Klimach

Oliver Appel

Hans-Christian Clemen

Antonis Dragoneas

Christian Gurk

Andreas Hunig

Franziska Kollner

F Rubach

Christiane Schulz

Johannes Schneider

Stephan Borrmann
title: Application of an O ring pinch device as a constant pressure inlet (CPI) for airborne sampling
year: 2020

abstract: Functionalizing noble metal surfaces with (bio)organic molecules is a vibrant field of research, with key applications in medicine, catalysis, and molecular electronics. Control over the molecular self assembly is essential to creating functional devices. Here, we exploit our high pressure, high temperature scanning tunneling microscope (STM) to relate the effects of controllable parameters (temperature and pressure) to atomic scale assembly mechanisms. Using methanethiol self assembly on Au(111) as a model system, we monitor the formation and assembly of the ubiquitous (CH3S)2Au "staple" motif into row structures at pressures of up to 1 bar. We observe a pressure induced transition from the usual 1/3 monolayer (ML) saturation coverage in vacuum to 3/8 ML at 1 bar, thus providing the first evidence for a pressure gap effect for thiol adsorption. Complementing our experiments, we employed dispersion corrected density functional theory computations to model the formed surface adlayers, corresponding STM images, and underlying equilibrium thermodynamics.
author_names: Rik Valentijn Mom

Sigismund T A G Melissen

Philippe Sautet

Joost W M Frenken

Stephan N Steinmann

Irene M N Groot
title: The Pressure Gap for Thiols: Methanethiol Self Assembly on Au(111) from Vacuum to 1 bar
venue: The Journal of Physical Chemistry C
year: 2019

abstract: In this study, a hybrid multi cup electric cupping system (HMECS) was proposed, based on the ancient cupping method. HMECS consisted of several cups that could be used simultaneously to treat different areas of the patient's body. Each cup was equipped with its own pump and pressure monitoring system. Moreover, the vacuum pressure of the cups was controlled using fuzzy logic. Through automated control of the vacuum pressure, long term relief of muscle tightness was achieved. To develop a scientific foundation for this alternative treatment, we compared the VAS(Visual Analog Scale) and ODI(Oswestry Disability Index) scores from conventional basic cupping to the VAS and ODI scores for our proposed HMECS. The improvement rate in the VAS and ODI scores using HMECS after three treatments was higher than that achieved by basic cupping. These results, combined with the convenience offered by enhanced IT capabilities, should increase the popularity of this device among an aging society, and facilitate the opportunity to further explore the potential of Oriental medical practices.
author_names: Jong-Chan Kim

Tung-Shuen Wei

Jae-Sub Ko

Heung-Kook Choi

Myungja Tak

Chee-Yong Kim
title: A Study on Oriental Medicine Hybrid Multi cup Electric Cupping Contents using Vacuum Pressure
year: 2014

abstract: Getter materials are technically proven and industrially well implemented solutions for maintaining a vacuum inside electronic devices to assure long lifetimes and proper operating conditions. The pressure requirements of some hermetically packaged microelectromechanical systems (MEMS) devices, such as gyroscopes, accelerometers, infrared (IR) bolometers, and digital mirrors, are very stringent. The internal pressure can be as low as in the 10 3 mbar range. Due to the desorption phenomena of gaseous species from the internal surfaces, the vacuum inside such hermetically sealed electronic devices tends to degrade over time and, in the worst case, can affect the proper operation of the device. The integration of a special nanostructured getter film is an effective way to preserve and guarantee the performance of such devices. In addition to the getter material, there is also the need to develop and customize analytical techniques for post process vacuum quality control and reliability checks of hermetic bonding, which are extremely important for the assessment of a device's overall performance, lifetime, and manufacturing process yield.
author_names: L Mauri

A Porta

Alessio Corazza

Marco Moraja
title: Vacuum Packaging Requirements for MEMS and Characterization Techniques
year: 2020

abstract: BackgroundDamage control laparotomy, or abbreviated initial laparotomy followed by temporary abdominal closure (TAC) intensive care unit resuscitation, and planned re laparotomy, is frequently used to manage intra abdominal bleeding and contamination among critically ill or injured adults. Animal data suggest that TAC techniques that employ negative pressure to the peritoneal cavity may reduce the systemic inflammatory response and associated organ injury. The primary objective of this study is to determine if use of a TAC dressing that affords active negative pressure peritoneal therapy, the ABThera Open Abdomen Negative Pressure Therapy System, reduces the extent of the systemic inflammatory response after damage control laparotomy for intra abdominal sepsis or injury as compared to a commonly used TAC method that provides potentially less efficient peritoneal negative pressure, the Barker's vacuum pack.Methods/DesignThe Intra peritoneal Vacuum Trial will be a single center, randomized controlled trial. Adults will be intraoperatively allocated to TAC with either the ABThera or Barker's vacuum pack after the decision has been made by the attending surgeon to perform a damage control laparotomy. The study will use variable block size randomization. On study days 1, 2, 3, 7, and 28, blood will be collected. Whenever possible, peritoneal fluid will also be collected at these time points from the patient's abdomen or TAC device. Luminex technology will be used to quantify the concentrations of 65 mediators relevant to the inflammatory response in peritoneal fluid and plasma. The primary endpoint is the difference in the plasma concentration of the pro inflammatory cytokine IL 6 at 24 and 48 h after TAC dressing application. Secondary endpoints include the differential effects of these dressings on the systemic concentration of other pro inflammatory cytokines, collective peritoneal and systemic inflammatory mediator profiles, postoperative fluid balance, intra abdominal pressure, and several patient important outcomes, including organ dysfunction measures and mortality.DiscussionResults from this study will improve understanding of the effect of active negative pressure peritoneal therapy after damage control laparotomy on the inflammatory response. It will also gather necessary pilot information needed to inform design of a multicenter trial comparing clinical outcomes among patients randomized to TAC with the ABThera versus Barker's vacuum pack.Trial registrationClinicalTrials.gov identifierhttp:/www.clicaltrials.gov/ct2/show/NCT01355094
author_names: Derek J Roberts

Craig N Jenne

Chad Geoffrey Ball

Corina Tiruta

Caroline Leger

Zhengwen Jimmy Xiao

Peter Faris

Paul B McBeth

Christopher James Doig

Christine R Skinner

Stacy Ruddell

Paul Kubes

Andrew W Kirkpatrick
title: Efficacy and safety of active negative pressure peritoneal therapy for reducing the systemic inflammatory response after damage control laparotomy (the Intra peritoneal Vacuum Trial) study protocol for a randomized controlled trial
venue: Trials
year: 2013

abstract: In this study, we introduce a dynamic process model as well as the design methodology of optimized fuzzy controller for its efficient application to vacuum production system to produce a semiconductor, solar module and display and so on. In a vacuum control field, PID control method is widely used from the viewpoint of simple structure and preferred performance. But, PID control method is very sensitive to the change of environment of control system as well as the change of control parameters. Therefore, it`s difficult to get a preferred performance results from target system which has a complicated structure and lots of nonlinear factors. To solve such problem, we propose the design methodology of an optimized fuzzy PID controller through a following series of steps. First a dynamic characteristic of the target system is analyzed through a series of experiments. Second the process model is built up and its characteristic is compared with real process. Third, the optimized fuzzy PID controller is designed using genetic algorithms. Finally, the fuzzy controller is applied to target system and then its performance is compared with that of other conventional controllers(PID, PI, and Fuzzy PI controller) The performance of the proposed fuzzy controller is evaluated in terms of auto tuned control parameters and output responses considered by ITAE index, overshoot, rise time and steady state time.
author_names: Sung-Kwun Oh

Seukgu Cho

Seung-Joo Lee
title: Analysis of Dynamic Model and Design of Optimized Fuzzy PID Controller for Constant Pressure Control
year: 2012