504 research outputs found
Thermoelectric performance of weakly coupled granular materials
We study thermoelectric properties of inhomogeneous nanogranular materials
for weak tunneling conductance between the grains, g_t < 1. We calculate the
thermopower and figure of merit taking into account the shift of the chemical
potential and the asymmetry of the density of states in the vicinity of the
Fermi surface. We show that the weak coupling between the grains leads to a
high thermopower and low thermal conductivity resulting in relatively high
values of the figure of merit on the order of one. We estimate the temperature
at which the figure of merit has its maximum value for two- and
three-dimensional samples. Our results are applicable for many emerging
materials, including artificially self-assembled nanoparticle arrays.Comment: 4 pages, 3 figure
Management of patients with neck pain
Neck pain (cervicalgia) occupies one of the leading places among the reasons for outpatient visits, 75% of people have experienced neck pain at least once in their lives. In most cases, neck pain regresses; however, it recurs in almost one half of patients. The paper gives data on the risk factors, mechanisms, course, and prognosis of cervicalgia. It discusses the issues of differential diagnosis, examination, and approaches to treating this condition in these patients. Nonsteroidal anti-inflammatory drugs are most effective in treating patients with acute cervicalgia. Therapeutic exercises and manual therapy are indicated in patients with chronic cervicalgia. There is evidence on the efficacy and safety of meloxicam for the management of acute and chronic cervicalgia
Thermoelectric performance of granular semiconductors
We study thermoelectric properties of granular semiconductors with weak
tunneling conductance between the grains, g_t < 1. We calculate the thermopower
and figure of merit taking into account the shift of the chemical potential and
the asymmetry of the density of states in the vicinity of the Fermi surface due
to n- or p-type doping in the Efros-Shklovskii regime for temperatures less
than the charging energy. We show that for weakly coupled semiconducting grains
the figure of merit is optimized for grain sizes of order 5nm for typical
materials and its values can be larger than one. We also study the case of
compensated granular semiconductors and show that in this case the thermopower
can be still finite, although two to three orders of magnitude smaller than in
the uncompensated regime.Comment: 4 pages, 4 figure
Treatment for low back pain, use of meloxicam
To manage patients with low back pain is an urgent problem of modern medicine. The paper considers the main causes of chronic nonspecific lumbago and the principles of its diagnosis and treatment in the context of evidence-based medicine. Medical treatment using analgesics (nonsteroidal anti-inflammatory drugs (NSAIDs), weak opioids), antidepressants, therapeutic exercises, and cognitive-behavioral therapy as components of a multidisciplinary treatment is noted to be highly effective. The efficacy and side effects of NSAIDs, the high efficiency and safety of using meloxicam in different dosage forms are outlined.The authors set forth their experience in treating 85 patients with chronic low back pain and an observation of a female patient who has concurrent chronic migraine and abuses analgesics
Deformations of Existing Buildings, Caused by Construction Activities
Construction of a new building (NB) affects existing adjacent old buildings (OB) during pit excavation, piling, footing and NB erection. Two relevant history cases are described. In the first one, the graphs of OB settlements versus distance from the pit are given for the period of pit excavation and the total settlements for the period of NB erection. The second case gives the family of OB settlement time-related graphs versus distance from the pit, in which these settlements were caused by piling operations
- …