Measurement of the inelastic proton-proton cross section at s = 13 $$ \sqrt{s}=13 $$ TeV

Sirunyan, A. M.,Tumasyan, A.,Adam, W.,Ambrogi, F.,Asilar, E.,Bergauer, T.,Brandstetter, J.,Brondolin, E.,Dragicevic, M.,Erö,, J.,Escalante Del Valle, A.,Flechl, M.,Friedl, M.,Frü,hwirth, R.,Gh Springer-Verlag 2018 Journal of high energy physics Vol.2018 No.7

<P>A measurement of the inelastic proton-proton cross section with the CMS detector at a center-of-mass energy of root s = 13 TeV is presented. The analysis is based on events with energy deposits in the forward calorimeters, which cover pseudorapidities of -6.6 < eta < -3.0 and +3.0 < eta < +5.2. An inelastic cross section of 68.6 +/- 0.5(syst) +/- 1.6(lumi) mb is obtained for events with M-x > 4.1 GeV and/or M-Y > 13 GeV, where M-x and M-Y are the masses of the diffractive dissociation systems at negative and positive pseudorapidities, respectively. The results are compared with those from other experiments as well as to predictions from high-energy hadron-hadron interaction models.</P>

Search for natural and split supersymmetry in proton-proton collisions at s = 13 $$ \sqrt{s}=13 $$ TeV in final states with jets and missing transverse momentum

Sirunyan, A. M.,Tumasyan, A.,Adam, W.,Ambrogi, F.,Asilar, E.,Bergauer, T.,Brandstetter, J.,Brondolin, E.,Dragicevic, M.,Erö,, J.,Escalante Del Valle, A.,Flechl, M.,Friedl, M.,Frü,hwirth, R.,Gh Institute of Physics Pub 2018 The journal of high energy physics Vol.2018 No.5

<P>A search for supersymmetry (SUSY) is performed in final states comprising one or more jets and missing transverse momentum using data from proton-proton collisions at a centre-of-mass energy of 13 TeV. The data were recorded with the CMS detector at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb(-1). The number of signal events is found to agree with the expected background yields from standard model processes. The results are interpreted in the context of simplified models of SUSY that assume the production of gluino or squark pairs and their prompt decay to quarks and the lightest neutralino. The masses of bottom, top, and mass-degenerate light-flavour squarks are probed up to 1050, 1000, and 1325 GeV, respectively. The gluino mass is probed up to 1900, 1650, and 1650 GeV when the gluino decays via virtual states of the aforementioned squarks. The strongest mass bounds on the neutralinos from gluino and squark decays are 1150 and 575 GeV, respectively. The search also provides sensitivity to simplified models inspired by split SUSY that involve the production and decay of long-lived gluinos. Values of the proper decay length CT0 from 10(-3) to 10(5) mm are considered, as well as a metastable gluino scenario. Gluino masses up to 1750 and 900 GeV are probed for CT0 = 1mm and for the metastable state, respectively. The sensitivity is moderately dependent on model assumptions for CT0 greater than or similar to 1 m. The search provides coverage of the CT0 parameter space for models involving long-lived gluinos that is complementary to existing techniques at the LHC.</P>

Electroweak production of two jets in association with a Z boson in proton-proton collisions at $$\sqrt{s}= $$ s = 13 $$\,\text {TeV}$$ TeV

Sirunyan, A. M.,Tumasyan, A.,Adam, W.,Ambrogi, F.,Asilar, E.,Bergauer, T.,Brandstetter, J.,Brondolin, E.,Dragicevic, M.,Erö,, J.,Del Valle, A. Escalante,Flechl, M.,Friedl, M.,Frü,hwirth, R.,Gh Springer-Verlag 2018 The European physical journal. C, Particles and fi Vol.78 No.7

<P>A measurement of the electroweak (EW) production of two jets in association with a Z boson in proton-proton collisions at root s = 13 TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lljj final state with l including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses m(ll) > 50 GeV, m(jj) > 120 GeV, and transverse momenta P-Tj > 25 GeV is sigma(EW) (lljj) = 534 +/- 20 (stat) fb (syst) fb, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are -2.6 < cwww/Lambda(2) < 2.6 TeV-2 and -8.4 < cw/Lambda(2) < 10.1 TeV-2. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.</P>

Search for a heavy right-handed W boson and a heavy neutrino in events with two same-flavor leptons and two jets at s = 13 $$ \sqrt{s}=13 $$ TeV

Sirunyan, A. M.,Tumasyan, A.,Adam, W.,Ambrogi, F.,Asilar, E.,Bergauer, T.,Brandstetter, J.,Brondolin, E.,Dragicevic, M.,Erö,, J.,Escalante Del Valle, A.,Flechl, M.,Friedl, M.,Frü,hwirth, R.,Gh Institute of Physics Pub 2018 The journal of high energy physics Vol.2018 No.5

<P>A search for a heavy right-handed W boson (W-R) decaying to a heavy right-handed neutrino and a charged lepton in events with two same-flavor leptons (e or mu) and two jets, is presented. The analysis is based on proton-proton collision data, collected by the CMS Collaboration at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb(-1). No significant excess above the standard model expectation is seen in the invariant mass distribution of the dilepton plus dijet system. Assuming that couplings are identical to those of the standard model, and that only one heavy neutrino flavor N-R contributes significantly to the W-R decay width, the region in the two-dimensional (m(WR), m(NR)) mass plane excluded at 95% confidence level extends to approximately m(WR) = 4 : 4TeV and covers a large range of right-handed neutrino masses below the W-R boson mass. This analysis provides the most stringent limits on the W-R mass to date.</P>

Experimental study on optimization of CO₂ laser welding parameters for polypropylene-clay nanocomposite welds

M. R. Nakhaei,N. B. Mostafa Arab,Gh. Naderi,M. Hoseinpour Gollo 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.3

In this paper, polypropylene-clay nanocomposite sheets of 2 mm thickness with 0 wt%, 3 wt% and 5 wt% nanoclay are butt welded using a CO2 laser to determine the effect of clay content and laser process parameters on weld tensile strength. For this purpose, Taguchi parametric design and optimization method was used to design experiments and develop a model to predict weld tensile strength as a function of clay content and laser process parameters such as laser power, welding speed and focal position. The adequacy of the model was checked using analysis of variance and by conducting extra confirmation tests. Using Taguchi optimization approach, the optimum levels of parameters were determined. The results indicated that an increase in clay content and welding speed decreased the weld strength, whereas increasing laser power increased weld strength. Furthermore, increase in focal position showed an increasing and then a decreasing effect on weld strength.

Out of plane behavior of walls, using rigid block concepts

Gh.M, Mohammadi,F, Yasrebi Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.3

Out of plane behaviors of walls and infills are investigated in this paper, using rigid block concepts. Walls and infills are sometimes separated from top beams because of in plane movement of the walls and crumbling mortar layers under the top beams. Therefore, sufficient strength should be supplied to hold them against out of plane forces. Such walls are studied here under some real and scaled earthquakes, regarding their out of plane behavior. Influences of some reinforcements, connecting the walls to frames or perpendicular walls, are also studied. It is shown that unreinforced walls of regular sizes (3 m high and 4.5 m long) are normally unstable in the earthquakes. However, performing some reinforced bars that connect them to adjacent elements- frames or perpendicular walls - stabilizes them. Eventually, it is concluded that supplying 3 reinforced bars at 1/4, 2/4 and 3/4 of the panel's height stabilizes the walls in the assumed earthquakes. In this regard, for 20 cm and 35 cm thick walls ${\Phi}$18mm and ${\Phi}$20mm bars are to be used, respectively. For walls with other configurations, the forces and required areas of the reinforcements can be determined by the developed method of this paper.

Analytical solution for dynamic behavior of multiwall carbon nanotubes subjected to mechanical shock loading

M. Tahani,M. H. Abolbashari,Gh. Mohajeri Minaei,S. T. Talebian 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

Dynamic behavior and frequency analysis of multiwall carbon nanotubes (MWCNTs) with finite length are investigated using an analyticalmethod. By applying multiple elastic shells and a linearized model of van der Waals forces, a comprehensive continuum dynamicmodel of MWCNTs is developed. Also, by utilizing Laplace transform, time histories of MWCNTs subjected to shock lading are obtained. Then by using the fast Fourier transform (FFT), the time responses are transferred to the frequency domain and natural frequenciesare found. The accuracy of results is verified by comparing the results of sudden loading with those obtained by numerical methods. Furthermore, an abrupt unloading after ramp loading is simulated, and the dependency of diameter and length on the axial and radialnatural frequencies of MWCNTs is examined. Also, by characterizing the longitudinal displacement, the wave propagation velocities areobtained and an explicit expression is found for the axial natural frequencies of MWCNTs subjected to shock loading.

Application of frictional sliding fuse in infilled frames, fuse adjustment and influencing parameters

M. Mohammadi-Gh,V. Akrami 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.6

An experimental investigation is conducted here to study the effects of applying frictional sliding fuses (FSF) in concrete infilled steel frames. Firstly, the influences of some parameters on the behavior of the sliding fuse are studied: Methods of adjusting the FSF for a certain sliding strength are explained and influences of time duration, welding and corrosion are investigated as well. Based on the results, time duration does not significantly affect the FSF, however influences of welding and corrosion of the constitutive plates are substantial. Then, the results of testing two 1/3 scale single-storey single-bay concrete infilled steel frames having FSF are presented. The specimens were similar, except for different regulations of their fuses, tested by displacement controlled cyclic loading. The results demonstrate that applying FSF improves infill behaviors in both perpendicular directions. The infilled frames with FSF have more appropriate hysteresis cycles, higher ductility, much lower deteriorations in strength and stiffness in comparison with regular ones. Consequently, the infills, provided with FSF, can be regarded as an engineered element, however, special consideration should be taken into the affecting parameters of their fuses.

Out of plane behavior of walls, using rigid block concepts

Mohammadi Gh.M.,Yasrebi F. 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.3

Out of plane behaviors of walls and infills are investigated in this paper, using rigid block concepts. Walls and infills are sometimes separated from top beams because of in plane movement of the walls and crumbling mortar layers under the top beams. Therefore, sufficient strength should be supplied to hold them against out of plane forces. Such walls are studied here under some real and scaled earthquakes, regarding their out of plane behavior. Influences of some reinforcements, connecting the walls to frames or perpendicular walls, are also studied. It is shown that unreinforced walls of regular sizes (3 m high and 4.5 m long) are normally unstable in the earthquakes. However, performing some reinforced bars that connect them to adjacent elements- frames or perpendicular walls - stabilizes them. Eventually, it is concluded that supplying 3 reinforced bars at 1/4, 2/4 and 3/4 of the panel’s height stabilizes the walls in the assumed earthquakes. In this regard, for 20 cm and 35 cm thick walls Φ18mm and Φ20mm bars are to be used, respectively. For walls with other configurations, the forces and required areas of the reinforcements can be determined by the developed method of this paper.

Feasibility of using biogas in a micro turbine for supplying heating, cooling and electricity for a small rural building

Rajaei, Gh.,Atabi, F.,Ehyaei, M.A. Techno-Press 2017 Advances in energy research Vol.5 No.2

In this study, the use of a micro gas turbine system using biogas to supply heating, cooling and electricity loads of a rural building located in rural area around Tehran has been studied. Initially, the amount of energy needed by the farmhouse was calculated and then the number of needed microturbines was determined. Accordingly, the amount of substances entering biogas digester as well as tank volume were determined. The results of this study showed that village house loads including electrical, heating and cooling and hot water loads can be supplied by using a microturbine with a nominal power of 30 kW and $33.5m^3/day$ of biogas. Digester tank and reservoir tank volumes are $67m^3$ and $31.2m^3$, respectively. The cost of electricity produced by this system is 0.446 US$/kWh. For rural area in Iran, this system is not compatible with micro gas turbine and IC engine system use urban natural gas due to low price of natural gas in Iran, but it can be compatible by wind turbine, photovoltaic and hybrid system (wind turbine& photovoltaic) systems.