Reliability History and Improvements to the ANL 50 MEV H- Accelerator

The H- Accelerator consists of a 750 keV Cockcroft Walton preaccelerator and an Alvarez type 50 MeV linac. The accelerator has been in operation since 1961. Since 1981, it has been used as the injector for the Intense Pulsed Neutron Source (IPNS), a national user facility for neutron scattering. The linac delivers about 3.5x1012 H- ions per pulse, 30 times per second (30 Hz), for multi-turn injection to a 450 MeV Rapid Cycling Synchrotron (RCS). IPNS presently operates about 4,000 hours per year, and operating when scheduled is critical to meeting the needs of the user community. For many years the IPNS injector/RCS has achieved an average reliability of 95%, helped in large part by the preaccelerator/linac which has averaged nearly 99%. To maintain and improve system reliability, records need to show what each subsystem contributes to the total down time. The history of source and linac subsystem reliability, and improvements that have been made to improve reliability, will be described. Plans to maintain or enhance this reliability for at least another ten years of operation, will also be discussed.Comment: 3 pages, 1 figur

Kompakt 2.0: estació de bombers i centre expositiu per la prevenció d’incendis

El projecte planteja un edifici de programa mixt que combina una estació de bombers amb un centre divulgatiu i museu dedicat als incendis i la seva prevenció. Aquest edifici se situa en el nou passeig marítim de la capital Noruega on s'està creant un nou eix cultural i turístic que obre la ciutat de cara al mar

A Real-Time Energy Monitor System for the Ipns Linac

Injected beam energy and energy spread are critical parameters affecting the performance of our rapid cycling synchrotron (RCS). A real-time energy monitoring system is being installed to examine the H- beam out of the Intense Pulsed Neutron Source (IPNS) 50 MeV linac. The 200 MHz Alvarez linac serves as the injector for the 450 MeV IPNS RCS. The linac provides an 80 ms macropulse of approximately 3x1012 H- ions 30 times per second for coasting-beam injection into the RCS. The RCS delivers protons to a heavy-metal spallation neutron target for material science studies. Using a number of strip-line beam position monitors (BPMs) distributed along the 50 MeV transport line from the linac to the RCS, fast signals from the strip lines are digitized and transferred to a computer which performs an FFT. Corrections for cable attenuation and oscilloscope bandwidth are made in the frequency domain. Rectangular pulse train phasing (RPTP) is imposed on the spectra prior to obtaining the inverse transform (IFFT). After the IFFT, the reconstructed time-domain signal is analyzed for pulse width as it progresses along the transport line. Time-of-flight measurements of the BPM signals provide beam energy. Finally, using the 3-size measurement technique, the longitudinal emittance and energy spread of the beam are determined

A door lock only accessible from one side at a time

A retrofit replacement to a Euro profile cylinder lock, ideal for secondary doors which are rarely accessed from the outside of a property

3′ UTR G-quadruplexes regulate miRNA binding

Abstract : MicroRNAs (miRNAs) are small noncoding RNAs that repress the translation of their target genes. It has previously been shown that a target’s availability to miRNA can be affected by its structure. G-quadruplexes (G4) are noncanonical structures adopted by G-rich nucleic acids that have been shown to have multiple biological functions. In this study, whether or not G4 structures’ presence in the 3′ UTRs of mRNAs can hinder miRNA binding was investigated. Putative G4 overlapping with predicted miRNAs’ binding sites was searched for, and 44,294 hits were found in humans. The FADS2 mRNA/mir331-3p pair was selected as a model example. In-line probing and G4-specific fluorescent ligand experiments binding were performed and confirmed the presence of a G4 near the predicted miRNA binding site. Subsequent luciferase assays showed that the presence of the G4 prevents the binding of mir331-3p in cellulo. Together, these results served as proof of concept that a G4 structure present in a 3′ UTR sequence should be taken into consideration when predicting miRNA binding sites

Local lung hypoxia determines epithelial fate decisions during alveolar regeneration.

After influenza infection, lineage-negative epithelial progenitors (LNEPs) exhibit a binary response to reconstitute epithelial barriers: activating a Notch-dependent ΔNp63/cytokeratin 5 (Krt5) remodelling program or differentiating into alveolar type II cells (AEC2s). Here we show that local lung hypoxia, through hypoxia-inducible factor (HIF1α), drives Notch signalling and Krt5pos basal-like cell expansion. Single-cell transcriptional profiling of human AEC2s from fibrotic lungs revealed a hypoxic subpopulation with activated Notch, suppressed surfactant protein C (SPC), and transdifferentiation toward a Krt5pos basal-like state. Activated murine Krt5pos LNEPs and diseased human AEC2s upregulate strikingly similar core pathways underlying migration and squamous metaplasia. While robust, HIF1α-driven metaplasia is ultimately inferior to AEC2 reconstitution in restoring normal lung function. HIF1α deletion or enhanced Wnt/β-catenin activity in Sox2pos LNEPs blocks Notch and Krt5 activation, instead promoting rapid AEC2 differentiation and migration and improving the quality of alveolar repair

Bunch stabilization using rf phase modulation in the intense pulse neutron source (IPNS) rapid cycling synchrotron (RCS)

Phase modulation (PM) is used to increase the current limit in the IPNS RCS. A device referred to as a scrambler introduces a small oscillating phase between the two RCS rf cavities at approximately twice the synchrotrons frequency, f{sub s}. The modulation introduced by the scrambler generates longitudinal oscillations in the bunch at 2f{sub s}. Modulations in the bunch are also observed transversely indicating a coupling between longitudinal and transverse motion. Comparing PM with amplitude modulation (AM), coupling to the beam is roughly equivalent at 2f{sub s}