1,322 research outputs found
Do the new exchange rate indexes offer better answers to old questions?
Foreign exchange rates ; Dollar, American ; International trade
The recent decline in agricultural exports: is the exchange rate the culprit?
Exports ; Farm produce
Selecting an intermediate target for monetary policy
Monetary policy ; Money supply
Decoupling of epitaxial graphene via gold intercalation probed by dispersive Raman spectroscopy
Signatures of a superlattice structure composed of a quasi periodic arrangement of atomic gold clusters below an epitaxied graphene (EG) layer are examined using dispersive Raman spectroscopy. The gold-graphene system exhibits a laser excitation energy dependant red shift of the 2D mode as compared to pristine epitaxial graphene. The phonon dispersions in both the systems are mapped using the experimentally observed Raman signatures and a third-nearest neighbour tight binding electronic band structure model. Our results reveal that the observed excitation dependent Raman red shift in gold EG primarily arise from the modifications of the phonon dispersion in gold-graphene and shows that the extent of decoupling of graphene from the underlying SiC substrate can be monitored from the dispersive nature of the Raman 2D modes. The intercalated gold atoms restore the phonon band structure of epitaxial graphene towards free standing graphene
Continuous Commissioning of a Central Chilled Water & Hot Water System
A central chilled water / hot water system
provides cooling / heating energy from central utility
plants to multiple customers (buildings) through
campus distribution loops. To effectively transport
the chilled water and hot water to the buildings and
control the flow, several types of bypass schemes are
used, including air handling unit coil bypass, pump
bypass, building loop bypass, distribution loop
bypass, and central utility plant decoupling. Most of
the bypass schemes are designed to provide comfort
to each building without regard for the loop pumping
requirements. Continuous Commissioning of the
building and campus loops is necessary to ensure
adequate water flow to each building and reduce the
overall pumping energy required for both the campus
loops and the building loops. Some optimization of
the plant chiller 1 boiler operation is also necessary
and beneficial. In general, through Continuous
Commissioning, chilled water and hot water loop
temperature differences will be improved, leading to
reduced chilled water and hot water flow rates. This
will save pumping energy and improve chiller/boiler
efficiancy
Unusual magnetic-field dependence of partially frustrated triangular ordering in manganese tricyanomethanide
Manganese tricyanomethanide, Mn[C(CN)3]2, consists of two interpenetrating
three-dimensional rutile-like networks. In each network, the tridentate C(CN)3-
anion gives rise to superexchange interactions between the Mn2+ ions (S=5/2)
that can be mapped onto the "row model" for partially frustrated triangular
magnets. We present heat capacity measurements that reveal a phase transition
at T_N = 1.18K, indicative of magnetic ordering. The zero-field magnetically
ordered structure was solved from neutron powder diffraction data taken between
0.04 and 1.2 K. It consists of an incommensurate spiral with a temperature
independent propagation vector Q=(2Q 0 0)=(+/-0.622 0 0), where different signs
relate to the two different networks. This corresponds to (+/-0.311 +/-0.311 0)
in a quasi-hexagonal representation. The ordered moment mu=3.3mu_B is about 2/3
of the full Mn2+ moment. From the values of T_N and Q, the exchange parameters
J/k = 0.15 K and J'/J = 0.749 are estimated. The magnetic-field dependence of
the intensity of the Bragg reflection, measured for external fields
H||Q, indicates the presence of three different magnetic phases. We associate
them with the incommensurate spiral (H < 13.5 kOe), an intermediate phase (13.5
kOe 16 kOe)
proposed for related compounds. For increasing fields, Q continuously
approaches the value 1/3, corresponding to the commensurate magnetic structure
of the fully frustrated triangular lattice. This value is reached at H_c = 19
kOe. At this point, the field-dependence reverses and Q adopts a value of 0.327
at 26 kOe, the highest field applied in the experiment. Except for H_c, the
magnetic ordering is incommensurate in all three magnetic phases of
Mn[C(CN)3]2.Comment: accepted for publication in J. Phys.: Condens. Matte
- …