3,465 research outputs found
Policy Design for Controlling Set-Point Temperature of ACs in Shared Spaces of Buildings
Air conditioning systems are responsible for the major percentage of energy
consumption in buildings. Shared spaces constitute considerable office space
area, in which most office employees perform their meetings and daily tasks,
and therefore the ACs in these areas have significant impact on the energy
usage of the entire office building. The cost of this energy consumption,
however, is not paid by the shared space users, and the AC's temperature
set-point is not determined based on the users' preferences. This latter factor
is compounded by the fact that different people may have different choices of
temperature set-points and sensitivities to change of temperature. Therefore,
it is a challenging task to design an office policy to decide on a particular
set-point based on such a diverse preference set. As a result, users are not
aware of the energy consumption in shared spaces, which may potentially
increase the energy wastage and related cost of office buildings. In this
context, this paper proposes an energy policy for an office shared space by
exploiting an established temperature control mechanism. In particular, we
choose meeting rooms in an office building as the test case and design a policy
according to which each user of the room can give a preference on the
temperature set-point and is paid for felt discomfort if the set-point is not
fixed according to the given preference. On the other hand, users who enjoy the
thermal comfort compensate the other users of the room. Thus, the policy
enables the users to be cognizant and responsible for the payment on the energy
consumption of the office space they are sharing, and at the same time ensures
that the users are satisfied either via thermal comfort or through incentives.
The policy is also shown to be beneficial for building management. Through
experiment based case studies, we show the effectiveness of the proposed
policy.Comment: Journal paper accepted in Energy & Buildings (Elsevier
Nonlocality-controlled interaction of spatial solitons in nematic liquid crystals
We demonstrate experimentally that the interactions between a pair of
nonlocal spatial optical solitons in a nematic liquid crystal (NLC) can be
controlled by the degree of nonlocality. For a given beam width, the degree of
nonlocality can be modulated by varying the pretilt angle of NLC molecules via
the change of the bias. When the pretilt angle is smaller than pi/4, the
nonlocality is strong enough to guarantee the independence of the interactions
on the phase difference of the solitons. As the pretilt angle increases, the
degree of nonlocality decreases. When the degree is below its critical value,
the two solitons behavior in the way like their local counterpart: the two
in-phase solitons attract and the two out-of-phase solitons repulse.Comment: 3 pages, 4 figure
Novel proton conductors in the layered oxide material LixlAl0. 5Co0. 5O2
It is demonstrated that good proton conductors can be obtained in transition-element-rich layered intercalation materials such as LixAl0.5Co0.5O2. A power density of 173 mW cm−2 is achieved at 525 °C with a thick electrolyte (0.79 mm thick). The ionic conductivity of nominal LiAl0.5Co0.5O2 is 0.1 S cm−1 at 500 °C. This is the highest among known polycrystalline proton-conducting materials
All-optical wavelength-tunable narrow-linewidth fiber laser
Parameter regulations of narrow-linewidth fiber lasers in frequency domain
has drawn considerable interests for widespread applications in the light
quantum computing, precise coherent detection, and generation of micro-waves.
All-optical methods provide compact, precise and fast accesses to achieving
these lasers with wavelength-tunability. Here, the optical-thermal effects of
graphene is utilized to precisely control operations of free-running lasers
with a tuning speed of 140 MHz/ms. Assisted by the single-longitude-mode
operation and linewidth suppression of stimulated Brillouin backscattering, we
obtain an optical-controllable ~750 Hz fiber laser with a wavelength-tuning
range of 3.7 nm
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