Phonons, electrons and thermal transport in Planckian high Tc materials

The room-temperature thermal diffusivity of high Tc materials is dominated by phonons. This allows the scattering of phonons by electrons to be discerned. We argue that the measured strength of this scattering suggests a converse Planckian scattering of electrons by phonons across the room-temperature phase diagram of these materials. Consistent with this conclusion, the temperature derivative of the resistivity of strongly overdoped cuprates is noted to show a kink at a little below 200 K that we argue should be understood as the onset of a high-temperature Planckian T-linear scattering of electrons by classical phonons. This kink continuously disappears toward optimal doping, even while strong scattering of phonons by electrons remains visible in the thermal diffusivity, sharpening the long-standing puzzle of the lack of a feature in the T-linear resistivity at optimal doping associated with the onset of phonon scattering.

Axial Compressive Behavior of Geopolymer Recycled Lump Concrete

To reduce the environmental pollution from cement production and the damage to natural resources from aggregate mining in the concrete industry, a relatively new concrete, termed geopolymer recycled lump concrete (GRLC), which uses geopolymer as the binding material to replace traditional cement and uses large demolished concrete lumps (DCLs) to partly replace concrete, is prepared in this study. Cubic and cylindrical GRLC specimens containing fresh geopolymer concrete and DCLs were tested under axial compression with various parameters, including the compressive strength levels of both fresh geopolymer concrete and DCLs, and the replacement ratio of DCLs. The compressive behavior of the GRLC specimens was compared with traditional cement recycled lump concrete (CRLC) specimens, with test results showing that GRLC specimens possess higher compressive strength than CRLC specimens under the same experimental conditions, which is due to the strengthening effect that fresh geopolymer concrete has on the DCLs. From the scanning electron microscope pattern of the GRLC specimen, it is found that the geopolymer bonds well with the old mortar attached to DCLs. As the replacement ratio increases from 0% to 33%, the elastic modulus of GRLC increases by 5%–11% but Poisson’s ratio remains almost constant (in the 0.16–0.17 range). Based on the measured strength and the predicted results, which coincide with one another well, a modified method for predicting the compressive strength of GRLC cubic and cylindrical specimens is proposed.

Description of the statistical variations of the measured strength for brittle ceramics: A comparison between two-parameter Weibull distribution and normal distribution

It is generally assumed that the measured strength of brittle ceramics follows a Weibull distribution. However, there seems to be few sound and direct evidences to support this assumption. Several previous studies have shown that other distributions, such as normal distribution and log-normal distribution may describe more appropriately the strength data than Weibull distribution. In this paper, the efficiency of using a normal distribution to describe the strength which follows a Weibull distribution is examined based on Monte-Carlo simulations. It was shown that there exist strong correlations between the parameters of normal distribution and those of Weibull distribution. For the designed fracture probability not lower than 0.01, analyses based on both normal distribution and Weibull distribution may give nearly identical predictions for the applicable stress levels. For lower fracture probabilities, the differences between the predictions of both distributions are not significant. It was suggested that, if there is no evidence to confirm that the measured strength follows a certain distribution, normal distribution and Weibull distribution seem to have the same efficiency in analysing the statistical variations in the measured strength of ceramics.

Pregnancy outcomes in women of different body types in cervical insufficiency

The rate of preterm birth remains high and has no downward trend, despite the introduction of new technologies. Isthmic-cervical insufficiency is one of the most important causes of premature birth. At the same time, many issues related to the prediction and treatment of isthmic-cervical insufficiency remain open. There is now a sufficient number of studies showing the relationship between somatotype, course and outcome of the disease. At the same time, stu dies related to the study of somatotypes in obstetric pathology are not enough. The aim of the work is to assess the outcomes of pregnancy in women with isthmic-cervical insufficiency, taking into account the type of physique. Materials and methods. the course and outcomes of pregnancy in 164 women with cervical insufficiency were studied. A computer somatotropina by R.N. Dorokhov all the best for measured strength of the pelvic floor muscles using a device pelvic muscle trainer. Conclusions. The most frequently CI was found in women with mesosomatic and micro mesosomatic somatotype. Women macromesosomatic and micromesosomatic body types revealed low levels of muscle strength of the pelvic floor and a higher percentage of premature births. In groups macrosomy, macromesosomatic, microsomal body types often use different methods of correction CI. At the same time, the highest percentage of surgical correction of CI was observed in patients with macrosomatic type of physique. In other patients with different somatotypes, a non-surgical correction method was used.

Motor Examination in the Diagnosis of Carpal Tunnel Syndrome

The relative importance and use of motor evaluation to diagnose carpal tunnel syndrome (CTS) is not clear. Because the ulnar nerve is not affected in CTS, we evaluated comparing the strength of the median-nerve innervated muscles to the ulnar innervated muscles in the same patient, through manual muscle testing (MMT) and a handheld dynamometer. Our purpose was to evaluate whether this method, which takes into account patient-dependent factors that would affect both groups of muscles equally, can provide better assessment of CTS. A retrospective case-control review of MMT and dynamometer-measured strength for CTS was performed. The study was performed retrospectively but prior to surgery or other treatment. There were 28 cases (CTS) and 14 controls (without CTS). Positive nerve conduction tests defined cases. MMT of the thenar musculature was found to be unreliable as a test for CTS. Comparisons to ulnar nerve innervated muscle strength did not improve sensitivity or specificity of the MMT examination. Use of the dynamometer improved sensitivity and specificity of motor testing in CTS over MMT. Motor evaluation is important for the diagnosis of CTS, but further study is warranted, specifically to define the method of motor evaluation and delineate the subgroup of patients (predominantly thenar motor presentation) that would benefit most from motor testing and motor-focused treatment.

Mechanical properties of micro- and nanocrystalline diamond foils

Diamond coating of suitable template materials and subsequent delamination allows for the manufacturing of free-standing diamond foil. The evolution of the microstructure can be influenced by secondary nucleation via control of process conditions in the hot-filament chemical vapour deposition process. Bending tests show extraordinarily high strength (more than 8 GPa), especially for diamond foils with nanocrystalline structure. A detailed fractographic analysis is conducted in order to correlate measured strength values with crack-initiating defects. The size of the failure causing flaw can vary from tens of micrometres to tens of nanometres, depending on the diamond foil microstructure as well as the loading conditions.