Phase 9 Fiber Optic Cable Microbending and Temperature Cycling Tests

Optical fibers represent the back bone of the current communications networks. Their performance in the field lacks long term testing data because of the continuous evolution of the manufacturing of fibers and cables. An optical fiber cable that is installed in NASA's KSC has experienced a dramatic increase in attenuation after three years of use from 0.7 dB/km to 7 dB/km in some fibers. A thorough study is presented to assess the causes of such an attenuation increase. Material and chemical decomposition testing showed that there are no changes in the composition of the fiber which might have caused the increase in attenuation. Microbending and heat cycling tests were performed on the cable and individual fibers. It was found that the increase in attenuation is due to microbending caused by excessive stress exerted on the fibers. This was the result of manufacturing and installation irregularities

2022 Upgrade and Improved Low Frequency Camera Sensitivity for CMB Observation at the South Pole

Constraining the Galactic foregrounds with multi-frequency Cosmic Microwave Background (CMB) observations is an essential step towards ultimately reaching the sensitivity to measure primordial gravitational waves (PGWs), the sign of inflation after the Big-Bang that would be imprinted on the CMB. The BICEP Array telescope is a set of multi-frequency cameras designed to constrain the energy scale of inflation through CMB B-mode searches while also controlling the polarized galactic foregrounds. The lowest frequency BICEP Array receiver (BA1) has been observing from the South Pole since 2020 and provides 30 GHz and 40 GHz data to characterize the Galactic synchrotron in our CMB maps. In this paper, we present the design of the BA1 detectors and the full optical characterization of the camera including the on-sky performance at the South Pole. The paper also introduces the design challenges during the first observing season including the effect of out-of-band photons on detectors performance. It also describes the tests done to diagnose that effect and the new upgrade to minimize these photons, as well as installing more dichroic detectors during the 2022 deployment season to improve the BA1 sensitivity. We finally report background noise measurements of the detectors with the goal of having photon noise dominated detectors in both optical channels. BA1 achieves an improvement in mapping speed compared to the previous deployment season.Comment: Proceedings of SPIE Astronomical Telescopes + Instrumentation 2022 (AS22

Deep inelastic inclusive and diffractive scattering at Q2Q^2 values from 25 to 320 GeV2^2 with the ZEUS forward plug calorimeter

Deep inelastic scattering and its diffractive component, $ep \to e^{\prime}\gamma^* p \to e^{\prime}XN$, have been studied at HERA with the ZEUS detector using an integrated luminosity of 52.4 pb$^{-1}$. The $M_X$ method has been used to extract the diffractive contribution. A wide range in the centre-of-mass energy $W$ (37 -- 245 GeV), photon virtuality $Q^2$ (20 -- 450 GeV$^2$) and mass $M_X$ (0.28 -- 35 GeV) is covered. The diffractive cross section for $2 < M_X < 15$ GeV rises strongly with $W$, the rise becoming steeper as $Q^2$ increases. The data are also presented in terms of the diffractive structure function, $F^{\rm D(3)}_2$, of the proton. For fixed $Q^2$ and fixed $M_X$, \xpom F^{\rm D(3)}_2 shows a strong rise as \xpom \to 0, where \xpom is the fraction of the proton momentum carried by the Pomeron. For Bjorken-$x < 1 \cdot 10^{-3}$, \xpom F^{\rm D(3)}_2 shows positive $\log Q^2$ scaling violations, while for $x \ge 5 \cdot 10^{-3}$ negative scaling violations are observed. The diffractive structure function is compatible with being leading twist. The data show that Regge factorisation is broken.Comment: 89 pages, 27 figure

Analysis and Design of a New Dual Band Microstrip Patch Antenna Based on Slot Matching Y-Shaped

A new compact microstrip slot antenna with Y-shaped coupling aperture is proposed. This antenna is based on a rectangular form with a microstrip fed line for excitation, and consists of slots on the edge of the radiation patch to provide dual-band operation. The design and simulation of the antenna were performed using CST Microwave Studio simulator. A prototype of the proposed antenna has been constructed and tested. In order to validate the return loss of the prototype antenna, the experimental results are presented. The results show two available bands with –10 dB band S at 2.7 GHz and band C at 5 GHz. Also, good radiation performance and antenna gain over the two frequency ranges have been obtained. Computation results confirm the experimental findings

Emoji alter the perception of emotion in affectively neutral text messages

Previous studies of emoji effects on text sentiment demonstrate mixed findings. Further, these studies are limited by confounds, e.g., underlying text sentiment, lack of ecological validity. We considered emoji effects on the emotional valence of affectively neutral English-language text messages. We additionally considered differences across US-American, British, and Danish participants. 217 participants considered screenshots of question-and-response text message exchanges with/without emoji, in a 4 (emoji type: no emoji, negative, neutral, positive) × 3 (nationality: American, British, Danish) mixed-factors design. Cumulative link mixed-effects models demonstrated that messages + negative emoji were rated more-negatively than any other emoji conditions. Responses + positive emoji were rated more-positively than any other emoji condition. Responses + neutral emoji and responses without emoji were perceived as equally emotive. There was no emoji type × nationality interaction, suggesting that emoji effects were consistent across participants. Findings are considered viz linguistic processing, social interactions, education, marketing, and public health interventions

Experimental and numerical study of chemiluminescent species in low-pressure flames

Kathrotia T, Riedel U, Seipel A, Moshammer K, Brockhinke A. Experimental and numerical study of chemiluminescent species in low-pressure flames. APPLIED PHYSICS B. 2012;107(3):571-584