816 research outputs found
4-Formylphenyl 2,3,4,6-tetra-O-acetyl-β-d-galactopyranoside
The galactose ring in the title compound, C21H24O11, has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing features C—H⋯O interactions that lead to the formation of supramolecular layers in the ab plane
Biosynthesis and characterization of polyhydroxyalkanoates copolymers produced by pseudomonas putida bet001 isolated from palm oil mill effluent
The biosynthesis and characterization of medium chain length poly-3-hydroxyalkanoates (mcl-PHA) produced by
Pseudomonas putida Bet001 isolated from palm oil mill effluent was studied. The biosynthesis of mcl-PHA in this newly isolated microorganism follows a growth-associated trend. Mcl-PHA accumulation ranging from 49.7 to 68.9% on cell dry weight (CDW) basis were observed when fatty acids ranging from octanoic acid (C8:0) to oleic acid (C18:1) were used as sole carbon and energy source. Molecular weight of the polymer was found to be ranging from 55.7 to 77.7 kDa. Depending on the type of fatty acid used, the 1H NMR and GCMSMS analyses of the chiral polymer showed a composition of even and odd carbon atom chain with monomer length of C4 to C14 with C8 and C10 as the principal monomers. No unsaturated monomer was detected. Thermo-chemical analyses showed the accumulated PHA to be semi-crystalline polymer with good thermal stability, having a thermal degradation temperature (Td) of 264.6 to 318.8 (60.2) oC, melting temperature (Tm) of 43.(60.2) oC, glass transition temperature (Tg) of 21.0 (60.2) oC and apparent melting enthalpy of fusion (DHf) of 100.9 (60.1) J
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Latest Results from the Heidelberg-Moscow Double Beta Decay Experiment
New results for the double beta decay of 76Ge are presented. They are
extracted from Data obtained with the HEIDELBERG-MOSCOW, which operates five
enriched 76Ge detectors in an extreme low-level environment in the GRAN SASSO.
The two neutrino accompanied double beta decay is evaluated for the first time
for all five detectors with a statistical significance of 47.7 kg y resulting
in a half life of (T_(1/2))^(2nu) = [1.55 +- 0.01 (stat) (+0.19) (-0.15)
(syst)] x 10^(21) years. The lower limit on the half-life of the 0nu beta-beta
decay obtained with pulse shape analysis is (T_(1/2))^(0_nu) > 1.9 x 10^(25)
[3.1 x 10^(25)] years with 90% C.L. (68% C.L.) (with 35.5 kg y). This results
in an upper limit of the effective Majorana neutrino mass of 0.35 eV (0.27 eV).
No evidence for a Majoron emitting decay mode or for the neutrinoless mode is
observed.Comment: 14 pages, revtex, 6 figures, Talk was presented at third
International Conference ' Dark Matter in Astro and Particle Physics' -
DARK2000, to be publ. in Proc. of DARK2000, Springer (2000). Please look into
our HEIDELBERG Non-Accelerator Particle Physics group home page:
http://www.mpi-hd.mpg.de/non_acc
Porous amphiphilic biogel from facile chemo-biosynthetic route
Grafting of medium-chain-length poly-3-hydroxyalkanoates (mcl- -PHA) with glycerol 1,3-diglycerolate diacrylate (GDD) in acetone was performed using benzoyl peroxide as the initiator. A detailed mechanism scheme provides significant improvement to previous literature. Radical-mediated grafting generated –carbon inter-linking of mcl-PHA and GDD, resulting in a macromolecular structure with gel properties. The thermal properties of the copolymer for different graft yields were investigated as a function of initiator concentration, GDD monomer concentration, incubation period and temperature. The water absorption and porosity of the gel were significantly improved relative to neat mcl-PHA
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Certification of Completion of Level-2 Milestone 464: Complete Phase 1 Integration of Site-Wide Global Parallel File System (SWGPFS)
There has been substantial development of the Lustre parallel filesystem prior to the configuration described below for this milestone. The initial Lustre filesystems that were deployed were directly connected to the cluster interconnect, i.e. Quadrics Elan3. That is, the clients (OSSes) and Meta-data Servers (MDS) were all directly connected to the cluster's internal high speed interconnect. This configuration serves a single cluster very well, but does not provide sharing of the filesystem among clusters. LLNL funded the development of high-efficiency ''portals router'' code by CFS (the company that develops Lustre) to enable us to move the Lustre servers to a GigE-connected network configuration, thus making it possible to connect to the servers from several clusters. With portals routing available, here is what changes: (1) another storage-only cluster is deployed to front the Lustre storage devices (these become the Lustre OSSes and MDS), (2) this ''Lustre cluster'' is attached via GigE connections to a large GigE switch/router cloud, (3) a small number of compute-cluster nodes are designated as ''gateway'' or ''portal router'' nodes, and (4) the portals router nodes are GigE-connected to the switch/router cloud. The Lustre configuration is then changed to reflect the new network paths. A typical example of this is a compute cluster and a related visualization cluster: the compute cluster produces the data (writes it to the Lustre filesystem), and the visualization cluster consumes some of the data (reads it from the Lustre filesystem). This process can be expanded by aggregating several collections of Lustre backend storage resources into one or more ''centralized'' Lustre filesystems, and then arranging to have several ''client'' clusters mount these centralized filesystems. The ''client clusters'' can be any combination of compute, visualization, archiving, or other types of cluster. This milestone demonstrates the operation and performance of a scaled-down version of such a large, centralized, shared Lustre filesystem concept
Designing Chatbots for Crises: A Case Study Contrasting Potential and Reality
Chatbots are becoming ubiquitous technologies, and their popularity and adoption are rapidly spreading. The potential of chatbots in engaging people with digital services is fully recognised. However, the reputation of this technology with regards to usefulness and real impact remains rather questionable. Studies that evaluate how people perceive and utilise chatbots are generally lacking. During the last Kenyan elections, we deployed a chatbot on Facebook Messenger to help people submit reports of violence and misconduct experienced in the polling stations. Even though the chatbot was visited by more than 3,000 times, there was a clear mismatch between the users’ perception of the technology and its design. In this paper, we analyse the user interactions and content generated through this application and discuss the challenges and directions for designing more effective chatbots
Implications of TCO Topography on Intermediate Reflector Design for a Si mc Si Tandem Solar Cells Experiments and Rigorous Optical Simulations
Large Transverse Momenta in Statistical Models of High Energy Interactions
The creation of particles with large transverse momenta in high energy
hadronic collisions is a long standing problem. The transition from small-
(soft) to hard- parton scattering `high-pt' events is rather smooth. In this
paper we apply the non-extensive statistical framework to calculate transverse
momentum distributions of long lived hadrons created at energies from low
(sqrt(s)~10 GeV) to the highest energies available in collider experiments
(sqrt(s)~2000 GeV). Satisfactory agreement with the experimental data is
achieved. The systematic increase of the non-extensivity parameter with energy
found can be understood as phenomenological evidence for the increased role of
long range correlations in the hadronization process.
Predictions concerning the rise of average transverse momenta up to the
highest cosmic ray energies are also given and discussed.Comment: 20 pages, 10 figure
4-Formylphenyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyranoside
The pyranoside ring in the title compound, C21H24O11, has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing is dominated by C—H⋯O interactions that lead to the formation of supramolecular layers in the ab plane
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