A Low Cost Remote Sensing System Using PC and Stereo Equipment

A system using a personal computer, speaker, and a microphone is used to detect objects, and make crude measurements using a carrier modulated by a pseudorandom noise (PN) code. This system can be constructed using a personal computer and audio equipment commonly found in the laboratory or at home, or more sophisticated equipment that can be purchased at reasonable cost. We demonstrate its value as an instructional tool for teaching concepts of remote sensing and digital signal processing.Comment: Accepted for publication in American Journal of Physic

Grain quality inspection system

A review of grain quality indicators and measurement methods was conducted in order to assess the feasibility of using remote sensing technology to develop a continuous monitoring system for use during grain transfer operations. Most detection methods were found to be too slow or too expensive to be incorporated into the normal inspection procedure of a grain elevator on a continuous basis. Two indicators, moisture content and broken corn and foreign material, show potential for automation and are of an economic value. A microprocessor based system which utilizes commercially available electronic moisture meter was developed and tested. A method for automating BCFM measurement is described. A complete system description is presented along with performance test results

Search for Low-Mass Dark-Sector Higgs Bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516  fb^(-1) of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the standard model-dark-sector mixing angle and the dark-sector coupling constant

Study of B → X_uℓv decays in BB events tagged by a fully reconstructed B-meson decay and determination of │V_(ub)│

We report measurements of partial branching fractions for inclusive charmless semileptonic B decays B → X_uℓν and the determination of the Cabibbo–Kobayashi–Maskawa (CKM) matrix element |V_(ub)|. The analysis is based on a sample of 467×10^6 Υ(4S)→BB decays recorded with the BABAR detector at the PEP-II e^+e^- storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions ΔB in several restricted regions of phase space and determine the CKM element |V_(ub)| based on different QCD predictions. For decays with a charged lepton momentum p_ℓ^*>1.0  GeV in the B meson rest frame, we obtain ΔB=(1.80±0.13_(stat)±0.15_(sys)±0.02_(theo))×10^(-3) from a fit to the two-dimensional M_X-q^2 distribution. Here, M_X refers to the invariant mass of the final state hadron X and q^2 is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |V_(ub)|=(4.33±0.24_(exp)±0.15_(theo))×10^(-3) as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for B^0 and B^- decays and derive a limit on the isospin breaking in B → X_uℓν decays

Search for lepton-number violating processes in B^+ → h^-l^+l^+ decays

We have searched for the lepton-number violating processes B^+→h^-ℓ^+ℓ^+ with h^-=K^-/π^- and ℓ^+=e^+/μ^+, using a sample of 471±3 million BB̅ events collected with the BABAR detector at the PEP-II e^+e^- collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90%-confidence-level upper limits on their branching fractions B(B^+→π^-e^+e^+)<2.3×10^(-8), B(B^+→K^-e^+e^+)<3.0×10^(-8), B(B^+→π^-μ^+μ^+)<10.7×10^(-8), and B(B^+→K^-μ^+μ^+)<6.7×10^(-8)

Precise measurement of the e^+e^- → π^+π^-(γ) cross section with the initial-state radiation method at BABAR

A precise measurement of the cross section of the process e^+e^-→π^+π^-(γ) from threshold to an energy of 3 GeV is obtained with the initial-state radiation (ISR) method using 232  fb^(-1) of data collected with the BABAR detector at e^+e^- center-of-mass energies near 10.6 GeV. The ISR luminosity is determined from a study of the leptonic process e^+e^-→μ^+μ^-(γ)γ_(ISR), which is found to agree with the next-to-leading-order QED prediction to within 1.1%. The cross section for the process e^+e^-→π^+π^-(γ) is obtained with a systematic uncertainty of 0.5% in the dominant ρ resonance region. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured ππ cross section from threshold to 1.8 GeV is (514.1±2.2(stat)±3.1(syst))×10^(-10)

Cross sections for the reactions e^+e^- → K^+K^-π^+π^-,K^+K^-π^0π^0, and K^+K^-K^+K^- measured using initial-state radiation events

We study the processes e^+e^- → K^+K^-π^+π^-γ, K^+K^-π^0π^0 γ, and K^+K^-K^+K^- γ, where the photon is radiated from the initial state. About 84 000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454  fb^(-1) of BABAR data. The invariant mass of the hadronic final state defines the e+e- center-of-mass energy, so that the K^+K^-π^+π^- γ data can be compared with direct measurements of the e^+e^- → K^+K^-π^+π^- reaction. No direct measurements exist for the e^+e^- → K^+K^-π^0π^0 or e^+e^- → K^+K^-K^+K^- reactions, and we present an update of our previous result based on a data sample that is twice as large. Studying the structure of these events, we find contributions from a number of intermediate states and extract their cross sections. In particular, we perform a more detailed study of the e^+e^- → ϕ(1020)ππγ reaction and confirm the presence of the Y(2175) resonance in the ϕ(1020)f_0(980) and K^+K^-f_0(980) modes. In the charmonium region, we observe the J/ψ in all three final states and in several intermediate states, as well as the ψ(2S) in some modes, and measure the corresponding products of branching fraction and electron width

Compatibility assessment of thermoplastic formulations

Presented at 19th Seminar on new trends in research of energetic materials (NTREM 2016)Prior to the large-scale preparation of any new chemical formulation an assessment of the potential reactivity between the components must be carried out. This practice, which is common to many fields including pharmaceutical science, is particularly essential in the case of energetic formulations whose chemical incompatibility may result in an unexpected and potentially explosive decomposition. The common method used to investigate incompatibility is to heat 1:1 (w/w) formulations and evaluate the variation in their thermal stability with respect to the neat, pristine explosive. The techniques used are: differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vacuum stability and heat flow calorimetry. As trends in energetics move towards safer formulations the components are more commonly selected for their high thermal stability and low sensitivity to initiation. However, recently prepared thermoplastic formulations which incorporate a thermally stable explosive, 2,2’,4,4’,6,6’-hexanitrostilbene (HNS II), and a selection of high-melting-point thermoplastics produced anomalous results during their compatibility assessment leading to the suggestion that historical tests originally devised for less thermally stable materials, such as N,N’,N’’-trinitro-1,3,5-triazacyclohexane (RDX), may not be directly transferable to the newer generations of insensitive explosive formulations