Pengembangan Desain Kapal Pancing Tonda dengan Material Fiberglass di Kabupaten Buton

Penggunaan kayu sebagai bahan pembuat kapal sudah mulai menghadapi permasalahan, khususnya kesediaan bahan baku. Selain semakin langkanya bahan baku kayu, harganya pun semakin mahal. Oleh karena itu upaya untuk mengaplikasikan bahan lain sebagai bahan pembuat kapal sudah saatnya dilakukan. Pada penelitian ini, salah satu bahan yakni fiberglass dicobakan untuk menggantikan kayu sebagai bahan pembuat kapal pancing tonda (troller). Walaupun harganya relatifmahal, namun untuk jangka panjang bahan ini lebih ekonomis. Hasil penelitian menunjukkan bahwa dengan aplikasi fiberglass, kapal yang dihasilkan lebih ringan dan menghasilkan kecepatan lebih tinggi dengan kekuatan mesin yang sama

Leaching Retention of CCA Metals from High- Temperature Reaction with Alkaline Earth and Iron Based Sorbents

Chromated copper arsenate (CCA) was the dominant wood preservative used for outdoor wood products to prevent structural decay prior to its phase down starting from 2004. Incineration is one key disposal alternative for CCA-treated wood; however, it results in volatilization of metals at high temperature and accumulation of metals in ash. The objective of this study was to assess alkaline earth and iron based sorbents for their capability to minimize leaching of metals from the incinerator ash. Experiments were carried out by heating CCA metal spikes combined with sorbents to temperatures of 700, 900 and 1100 oC. The residual ash was analyzed for leaching retention using the toxicity characteristic leaching procedure (TCLP) and speciation by X-ray diffraction (XRD). Results show that alkaline earth sorbents (cement, calcium hydroxide and magnesium hydroxide) were the most promising for reducing the leaching of arsenic from the ash below the 5 mg/L TCLP limit and retaining copper at concentrations below detection limits. For chromium, iron and magnesium based sorbents resulted the highest retention with low leachate concentrations (<5 mg/L) at temperatures of 1100 oC. Leaching appeared to be highly pH dependent with As and Cu leaching more at low pH values and Cr leaching more at high pH values. Results also indicate that the formation of compounds like Ca3As2O7, FeCr2O4 and CuCr2O4 during the reaction reduced the volatilization of metals. The results suggest that a combination of sorbents at different stages of high-temperature processes may offer effective control of the leaching of CCA metals.

Impact on Leaching & Retention of Metals from High Temperature Reaction of CCA Metals with Alumino-Silicate Sorbents

Past studies have shown that many alumino-silicate mineral sorbents are effective in controlling heavy metal emission during incineration. The objective of this study was to identify Al-Si based mineral sorbents that can minimize leaching of heavy metals from the incinerator ash of Chromated Copper Arsenate (CCA-) treated wood. Experiments were carried out using CCA metal spikes combined with Al-Si sorbents, heated to 700 oC, 900 oC and 1100 oC for 30 minutes. The residual ash was leached using the toxicity characteristic leaching procedure (TCLP).  X-Ray Diffraction (XRD) analysis was conducted to determine the crystalline speciation of the products. Results showed that low leaching was observed for chromium, below the 5 mg/L TC limit, by alumina and silica at all temperatures, and kaolin at higher temperatures (900 oC and 1100 oC). For copper, all sorbents displayed low leaching values (< 51 mg/l) as compared to the baseline. For arsenic, all sorbents exceeded the TC limit.  Speciation characterization results reveal the formation of several metal-metal and metal-mineral compounds that may have resulted in different leaching behaviors of each metal-sorbent pair under different combustion conditions. The results suggest a combination of sorbents at different stages of the combustion process can be effective to control the leaching of CCA metals

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

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Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurements of the Electroweak Diboson Production Cross Sections in Proton-Proton Collisions at root s=5.02 TeV Using Leptonic Decays

The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302 pb(-1). Events with two, three, or four charged light leptons (electrons or muons) in the final state are analyzed. The WW, WZ, and ZZ total cross sections are measured as sigma(WW) = 37:0(-5.2)(+5.5) (stat)(-2.6)(+2.7) (syst) pb, sigma(WZ) = 6.4(-2.1)(+2.5) (stat)(-0.3)(+0.5)(syst) pb, and sigma(ZZ) = 5.3(-2.1)(+2.5)(stat)(-0.4)(+0.5) (syst) pb. All measurements are in good agreement with theoretical calculations at combined next-to-next-to-leading order quantum chromodynamics and next-to-leading order electroweak accuracy