Effects of a Low Vacuum Level on Vacuum Stability and Milking Parlor Performance for Sheep

2009 ◽  
Vol 52 (1) ◽  
pp. 247-252 ◽  
Author(s):  
A. Pazzona ◽  
M. Caria ◽  
L. Murgia
Keyword(s):  
Vacuum Stability ◽  
Vacuum Level

scholarly journals Comparison of the operation of milking machine control valves and a newly designed regulating device

2012 ◽  
Vol 49 (No. 3) ◽  
pp. 110-114 ◽  
Author(s):  
J. Fryč
Keyword(s):  
Electric Power ◽  
Statistical Evaluation ◽  
Dynamic Properties ◽  
Vacuum Pump ◽  
Vacuum Stability ◽  
Vacuum Level ◽  
Control Valves ◽  
Machine Control ◽  
Milking Machine

One of the basic demands for milking machines is to maintain a constant vacuum level if air consumption by milking machine is changed. The author designed a device with reducing valve for vacuum level regulation and a simultaneous vacuum pump control enabling electric power to be reduced. The paper deals with a comparison of the operation of standard control valves with the newly designed device used for vacuum regulation from the viewpoint of dynamic properties. When measuring vacuum stability by applying various regulation methods and a subsequent statistical evaluation of the results obtained it was proven that the function of the newly designed regulating device was comparable with the best reducing valves used so far.

Effect of vacuum level on milk flow and vacuum stability in Alpine goat milking

2019 ◽  
Vol 171 ◽  
pp. 1-7
Author(s):  
M. Zucali ◽  
A. Tamburini ◽  
A. Sandrucci ◽  
G. Gislon ◽  
L. Bava
Keyword(s):  
Vacuum Stability ◽  
Vacuum Level ◽  
Milk Flow

scholarly journals Chern-Simons invariants and heterotic superpotentials

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Lara B. Anderson ◽  
James Gray ◽  
Andre Lukas ◽  
Juntao Wang
Keyword(s):  
Heterotic String ◽  
New Techniques ◽  
Vacuum Stability ◽  
Large Classes ◽  
Moduli Stabilization ◽  
String Compactifications ◽  
Key Features ◽  
Effective Theories ◽  
Chern Simons ◽  
Tangent Bundles

Abstract The superpotential in four-dimensional heterotic effective theories contains terms arising from holomorphic Chern-Simons invariants associated to the gauge and tangent bundles of the compactification geometry. These effects are crucial for a number of key features of the theory, including vacuum stability and moduli stabilization. Despite their importance, few tools exist in the literature to compute such effects in a given heterotic vacuum. In this work we present new techniques to explicitly determine holomorphic Chern-Simons invariants in heterotic string compactifications. The key technical ingredient in our computations are real bundle morphisms between the gauge and tangent bundles. We find that there are large classes of examples, beyond the standard embedding, where the Chern-Simons superpotential vanishes. We also provide explicit examples for non-flat bundles where it is non-vanishing and non-integer quantized, generalizing previous results for Wilson lines.

scholarly journals Neutrino masses, vacuum stability and quantum gravity prediction for the mass of the top quark

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Guillem Domènech ◽  
Mark Goodsell ◽  
Christof Wetterich
Keyword(s):  
Quantum Gravity ◽  
Top Quark ◽  
Quark Mass ◽  
Scalar Potential ◽  
Planck Scale ◽  
Neutrino Masses ◽  
Top Quark Mass ◽  
Vacuum Stability ◽  
Intermediate Scale ◽  
Yukawa Couplings

Abstract A general prediction from asymptotically safe quantum gravity is the approximate vanishing of all quartic scalar couplings at the UV fixed point beyond the Planck scale. A vanishing Higgs doublet quartic coupling near the Planck scale translates into a prediction for the ratio between the mass of the Higgs boson MH and the top quark Mt. If only the standard model particles contribute to the running of couplings below the Planck mass, the observed MH∼ 125 GeV results in the prediction for the top quark mass Mt∼ 171 GeV, in agreement with recent measurements. In this work, we study how the asymptotic safety prediction for the top quark mass is affected by possible physics at an intermediate scale. We investigate the effect of an SU(2) triplet scalar and right-handed neutrinos, needed to explain the tiny mass of left-handed neutrinos. For pure seesaw II, with no or very heavy right handed neutrinos, the top mass can increase to Mt ∼ 172.5 GeV for a triplet mass of M∆ ∼ 108GeV. Right handed neutrino masses at an intermediate scale increase the uncertainty of the predictions of Mt due to unknown Yukawa couplings of the right-handed neutrinos and a cubic interaction in the scalar potential. For an appropriate range of Yukawa couplings there is no longer an issue of vacuum stability.

DEPOSITION OF SINGLE-PHASE CuInSe2 THIN FILMS UNDER LOW VACUUM LEVEL BY A TWO-STAGE GROWTH TECHNIQUE

2009 ◽  
Vol 16 (03) ◽  
pp. 381-386 ◽  
Author(s):  
J. B. CHU ◽  
H. B. ZHU ◽  
Z. A. WANG ◽  
Z. Q. BIAN ◽  
Z. SUN ◽  
...  
Keyword(s):  
Solar Cells ◽  
Single Phase ◽  
Low Cost ◽  
Control Process ◽  
Rf Magnetron Sputtering ◽  
Chalcopyrite Structure ◽  
Sputtering Deposition ◽  
Vacuum Level ◽  
X Ray ◽  
High Efficient

Single-phase CuInSe 2 films were grown by high vapor selenization of CuIn alloy precursors within a partially closed graphite box. The CuIn precursors were prepared using Cu x In y alloy targets with different composition rates under low vacuum level by a homemade sputtering system. The Cu and In composition rates of the used targets are 11:9, 10:10, and 9:11, respectively. The metallic precursor films were selenized using a two-step temperature profile, i.e. at 250°C and 400–500°C, respectively. The influence of the temperature at the second selenization step on the quality of the CIS absorbing layers was investigated. The CIS films were characterized by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The deposited CIS absorbers selenized at a high temperature of 500°C for 30 min exhibited a single-phase chalcopyrite structure with a preferential orientation in the (112) direction. These layers display uniform, large, and densely packed crystals with a grain size of about 3–5 μm. Cadmium sulfide buffer layer was manufactured by chemical bath deposition method. Bilayers ZnO / ZnO : Al were prepared by RF magnetron sputtering deposition. CIS solar cells with an efficiency of about 6.5% were produced without antireflective films. The method to fabricate CIS solar cells by a combination of the low vacuum sputtering deposition and the graphite box selenization process has provided a simple control process and shown a promising potential for developing high efficient and low-cost CuInSe 2 solar cells.

scholarly journals Sub-TeV singlet scalar dark matter and electroweak vacuum stability with vectorlike fermions

2020 ◽  
Vol 102 (7) ◽  
Author(s):  
Debasish Borah ◽  
Rishav Roshan ◽  
Arunansu Sil
Keyword(s):  
Dark Matter ◽  
Vacuum Stability

Responses of the bovine teat to machine milking: measurement of changes in thickness of the teat apex

1988 ◽  
Vol 55 (3) ◽  
pp. 331-338 ◽  
Author(s):  
Jörn Hamann ◽  
Graeme A. Mein
Keyword(s):  
Positive Pressure ◽  
Vacuum Level ◽  
Machine Milking ◽  
Before And After ◽  
The Mean ◽  
High Degree

SummaryChanges in the teat apex before and after different milking treatments were measured with a spring-loaded caliper device known as a cutimeter which could detect changes in thickness of the tissues of the teat end, presumably due to congestion and/or oedema, with a high degree of accuracy (± 2%) and repeatability (r = 0·99). Teat end thickness increased with increasing vacuum level. The mean increase immediately after milking with a conventional cluster was 2% for 24 teats milked at 30 kPa, 8% at 50 kPa and 21% at 70 kPa. At these vacuum levels, the mean increases for the same teats milked with an unconventional (PKME) teatcup were 10, 18 and 25% respectively. Cyclic application of 35 kPa positive pressure to the pulsation chamber of a conventional teatcup operating at 50 kPa reduced teat end thickness by 8% compared with the mean premilking value. Although most teats returned to within ± 2% of their premilking thickness values by 1 h after milking, differences were apparent between different milking systems for up to 4 h postmilking.

scholarly journals Usefulness of Surgical Media Center as a Cataract Surgery Educational Tool

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Tomoichiro Ogawa ◽  
Takuya Shiba ◽  
Hiroshi Tsuneoka
Keyword(s):  
Cataract Surgery ◽  
Surgical Procedures ◽  
Intraoperative Complications ◽  
Recording Device ◽  
Educational Tool ◽  
Intraoperative Complication ◽  
Vacuum Level ◽  
Media Center ◽  
Medical Optics ◽  
Education Tool

Purpose.This study retrospectively analyzed cataract surgeries to examine the usefulness of Surgical Media Center (SMC) (Abbott Medical Optics Inc.), a new cataract surgery recording device, for training of cataract surgery.Methods.We studied five hundred cataract surgeries conducted with a phacoemulsification system connected to the SMC. After surgery, the surgical procedures were reviewed, with changes in aspiration rate, vacuum level, and phaco power displayed as graphs superimposed on the surgical video. We examined whether use of SMC is able to demonstrate the differences in technique between experienced and trainee operators, to identify inappropriate phacoemulsification techniques from analyzing the graphs, and to elucidate the cause of intraoperative complications.Results. Significant differences in the time taken to reach maximum vacuum and the speed of increase in vacuum during irrigation and aspiration were observed between experienced and trainee operators. Analysis of the graphs displayed by SMC detected inappropriate phacoemulsification techniques mostly in cases operated by trainee operators.Conclusions. Using SMC, it was possible to capture details of cataract surgery objectively. This recording device allows surgeons to review cataract surgery techniques and identify the cause of intraoperative complication and is a useful education tool for cataract surgery.

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