Less energy consumption, but how much?

The following report investigates the Almtuna preschool buildings potential improvements in energy efficiency. Almtuna preschool is owned by Skolfastigheter AB, which is a part of Uppsala Kommun. The preschool is situated in Fålhagen, east from the city centre. In November-December 2015 the old luminous lamps were replaced with the newer technique LED lamps. The results were based on a simulation model of the building in Simulink. The models corresponded closely with the reality. After the change of lamps, the total energy consumption decreased with 14% for January to Mars 2016 compared with the same months for 2011-2015. The findings of the report show that of the potential improvements only the ventilation would be a viable. The report suggests a photo voltaic system of 39 monocrystalline modules from the company JA Solar. These should be placed on the middle roof, and will produce about 10 500 kWh per year which is 16 % of the pre-school electricity consumption. In practice only 14 % of the buildings electricity consumption would be replaced as the electricity from the PV cells will be produced unevenly during the day and it is expected that at certain periods the PV cells will produce too much electricity for the building use. The estimated pay-back period for the investment and installation was 15 years. There is a possibility that the excess electricity produced could be sold to the grid. An alternative option is to store the energy in a battery. The suggested battery for energy storage is LiFePO₄ as it has a long lifespan and a high threshold to withstand up and down charges. The calculated potential energy storage during one year is 250 kWh. The report found however that the most economically viable option would be to sell the excess energy to the electricity network.Almtuna förskola ägs och förvaltas av Skolfastigheter AB, ett fastighetsföretag i Uppsala kommun. Förskolan ligger i stadsdelen Fålhagen öster om stadskärnan. I november-december 2015 utfördes ett byte av belysning från gamla lysrör till den senaste LED-tekniken. Denna studie har gjort en uppföljning på elförbrukningen efter lampbytet samt undersökt möjligheter för fortsatta energieffektiviseringar. Även potentialen för solkraft samt lagring av den producerade elektriciteten examinerades. Detta undersöktes med hjälp av en energimodell av byggnaden som utvecklades i mjukvaran Simulink. Valideringen visade att modellen stämde bra överens med verkligheten. Efter lampbytet minskade totala energiförbrukningen med 14 % för januari till mars 2016 jämfört med samma månader 2011-2015. Av energieffektiveringsåtgärderna (tilläggsisolering, byte av fönster och dörrar, ventilation, torkskåp och återkoppling av kökets luftflöden) som undersöktes var endast ventilationen som ansågs värd som investeringen. Studien föreslog även en anläggning på 39 moduler av monokristallina solceller från JA Solar placerade på mittentaket. De kommer enligt simulering i PVsyst producera ca 10 500 kWh per år vilket motsvarar 16 % av förskolans elförbrukning. I praktiken är det 14 % av förskolans elförbrukning som täcks då det sker överproduktion som dock kan säljas. Den uppskattade återbetalningstiden för enbart investering + installation är 15 år. Utifrån de genomförda simuleringarna framgick att överskottsel från solcellsanläggningen endast sker på helger, vilket leder till en relativt låg ekonomisk lagringspotential under året (ca 250 kWh). Studien visade att det var mer lönsam att sälja den överproducerade elen. Om lagringen skulle vara aktuell var alternativet med LiFePO₄-batteri mest intressant på grund av sin långa livslängd och förmåga att klara spridda upp- och ur-laddningar

Design and Performance of the mDOM Mainboard for the IceCube Upgrade

About 400 mDOMs (multi-PMT Digital Optical Modules) will be deployed as part of the IceCube Upgrade Project. The mDOM’s high pressure-resistant glass sphere houses 24 PMTs, 3 cameras, 10 flasher LEDs and various sensors. The mDOM mainboard design was challenging due to the limited available volume and demanding engineering requirements, like the maximum overall power consumption, a minimum trigger threshold of 0.2 photoelectrons (PE), the dynamic range and the linearity requirements. Another challenge was the FPGA firmware design, dealing with about 35 Gbit/s of continuous ADC data from the digitization of the 24 PMT channels, the control of a high speed dynamic buffer and the discriminator output sampling rate of about 1GSPS. High-speed sampling of each of the discriminator outputs at ~1 GSPS improves the leading-edge time resolution for the PMT waveforms. An MCU (microcontroller unit) coordinates the data taking, the data exchange with the surface and the sensor readout. Both the FPGA firmware and MCU software can be updated remotely. After discussing the main hardware blocks and the analog frontend (AFE) design, test results will be shown, covering especially the AFE performance. Additionally, the functionality of various sensors and modules will be evaluated

Galactic Core-Collapse Supernovae at IceCube: “Fire Drill” Data Challenges and follow-up

The next Galactic core-collapse supernova (CCSN) presents a once-in-a-lifetime opportunity to make astrophysical measurements using neutrinos, gravitational waves, and electromagnetic radiation. CCSNe local to the Milky Way are extremely rare, so it is paramount that detectors are prepared to observe the signal when it arrives. The IceCube Neutrino Observatory, a gigaton water Cherenkov detector below the South Pole, is sensitive to the burst of neutrinos released by a Galactic CCSN at a level >10σ. This burst of neutrinos precedes optical emission by hours to days, enabling neutrinos to serve as an early warning for follow-up observation. IceCube\u27s detection capabilities make it a cornerstone of the global network of neutrino detectors monitoring for Galactic CCSNe, the SuperNova Early Warning System (SNEWS 2.0). In this contribution, we describe IceCube\u27s sensitivity to Galactic CCSNe and strategies for operational readiness, including "fire drill" data challenges. We also discuss coordination with SNEWS 2.0

All-Energy Search for Solar Atmospheric Neutrinos with IceCube

The interaction of cosmic rays with the solar atmosphere generates a secondary flux of mesons that decay into photons and neutrinos – the so-called solar atmospheric flux. Although the gamma-ray component of this flux has been observed in Fermi-LAT and HAWC Observatory data, the neutrino component remains undetected. The energy distribution of those neutrinos follows a soft spectrum that extends from the GeV to the multi-TeV range, making large Cherenkov neutrino telescopes a suitable for probing this flux. In this contribution, we will discuss current progress of a search for the solar neutrino flux by the IceCube Neutrino Observatory using all available data since 2011. Compared to the previous analysis which considered only high-energy muon neutrino tracks, we will additionally consider events produced by all flavors of neutrinos down to GeV-scale energies. These new events should improve our analysis sensitivity since the flux falls quickly with energy. Determining the magnitude of the neutrino flux is essential, since it is an irreducible background to indirect solar dark matter searches

TXS 0506+056 with Updated IceCube Data

Past results from the IceCube Collaboration have suggested that the blazar TXS 0506+056 is a potential source of astrophysical neutrinos. However, in the years since there have been numerous updates to event processing and reconstruction, as well as improvements to the statistical methods used to search for astrophysical neutrino sources. These improvements in combination with additional years of data have resulted in the identification of NGC 1068 as a second neutrino source candidate. This talk will re-examine time-dependent neutrino emission from TXS 0506+056 using the most recent northern-sky data sample that was used in the analysis of NGC 1068. The results of using this updated data sample to obtain a significance and flux fit for the 2014 TXS 0506+056 "untriggered" neutrino flare are reported

Recent neutrino oscillation results with the IceCube experiment

The IceCube South Pole Neutrino Observatory is a Cherenkov detector instrumented in a cubic kilometer of ice at the South Pole. IceCube’s primary scientific goal is the detection of TeV neutrino emissions from astrophysical sources. At the lower center of the IceCube array, there is a subdetector called DeepCore, which has a denser configuration that makes it possible to lower the energy threshold of IceCube and observe GeV-scale neutrinos, opening the window to atmospheric neutrino oscillations studies. Advances in physics sensitivity have recently been achieved by employing Convolutional Neural Networks to reconstruct neutrino interactions in the DeepCore detector. In this contribution, the recent IceCube result from the atmospheric muon neutrino disappearance analysis using the CNN-reconstructed neutrino sample are presented and compared to the existing worldwide measurements