Heat production and error probability relation in Landauer reset at effective temperature

The erasure of a classical bit of information is a dissipative process. The minimum heat produced during this operation has been theorized by Rolf Landauer in 1961 to be equal to $k_B T \ln 2$ and takes the name of Landauer limit, Landauer reset or Landauer principle. Despite its fundamental importance, the Landauer limit remained untested experimentally for more than fifty years until recently when it has been tested using colloidal particles and magnetic dots. Experimental measurements on different devices, like micro-mechanical systems or nano-electronic devices are still missing. Here we show the results obtained in performing the Landauer reset operation in a micro-mechanical system, operated at an effective temperature. The measured heat exchange is in accordance with the theory reaching values close to the expected limit. The data obtained for the heat production is then correlated to the probability of error in accomplishing the reset operation

Band gap engineering of MoS2_2 upon compression

Molybdenum disulfide (MoS$_2$) is a promising candidate for 2D nanoelectronic devices, that shows a direct band-gap for monolayer structure. In this work we study the electronic structure of MoS$_2$ upon both compressive and tensile strains with first-principles density-functional calculations for different number of layers. The results show that the band-gap can be engineered for experimentally attainable strains (i.e. $\pm 0.15$). However compressive strain can result in bucking that can prevent the use of large compressive strain. We then studied the stability of the compression, calculating the critical strain that results in the on-set of buckling for free-standing nanoribbons of different lengths. The results demonstrate that short structures, or few-layer MoS$_2$, show semi-conductor to metal transition upon compressive strain without bucking

Sea surface temperature distribution in the Azores region. Part I: AVHRR imagery and in situ data processing.

Sixteen months of 1.1 km resolution NOAA-12, -14, and -16 data for the Azores region are investigated. Advanced Very High Resolution Radiometer (AVHRR) derived sea surface temperature (SST) is compared to an extensive in situ temperature measurement database, mainly constituted during fisheries campaigns. This comparison shows that SST maps include numerous pixels with temperature values below the range observed for the Azores. Low temperatures are attributed in literature to pixel contamination by cloud neighbouring and these are usually removed by eroding pixels around clouds. Results of this study show that running an erosion filter removes only two thirds of the contaminated pixels. Remnant clouds are filtered inputting threshold values to SST 8-day temperature histograms. Based on a comparison of the SST values derived on an image-by-image basis, it is also demonstrated that differences among the sensors are lower than the measurement accuracy, whilst, on the contrary, nighttime and daytime SST distributions are statistically different. Based on monthly and 15-day average computations at nighttime, AVHRR-derived SST distribution in the Azores and associated dominant space and time scales are proposed in the second part of this paper (SST distribution in the Azores region. Part II: Space and time variability and its relation to North Atlantic Oscillation)

Sea surface temperature distribution in the Azores region. Part I: AVHRR imagery and in situ data processing.

Sixteen months of 1.1 km resolution NOAA-12, -14, and -16 data for the Azores region are investigated. Advanced Very High Resolution Radiometer (AVHRR) derived sea surface temperature (SST) is compared to an extensive in situ temperature measurement database, mainly constituted during fisheries campaigns. This comparison shows that SST maps include numerous pixels with temperature values below the range observed for the Azores. Low temperatures are attributed in literature to pixel contamination by cloud neighbouring and these are usually removed by eroding pixels around clouds. Results of this study show that running an erosion filter removes only two thirds of the contaminated pixels. Remnant clouds are filtered inputting threshold values to SST 8-day temperature histograms. Based on a comparison of the SST values derived on an image-by-image basis, it is also demonstrated that differences among the sensors are lower than the measurement accuracy, whilst, on the contrary, nighttime and daytime SST distributions are statistically different. Based on monthly and 15-day average computations at nighttime, AVHRR-derived SST distribution in the Azores and associated dominant space and time scales are proposed in the second part of this paper (SST distribution in the Azores region. Part II: Space and time variability and its relation to North Atlantic Oscillation)

Nonlinear oscillators for vibration energy harvesting

Vibration to electricity energy conversion strategies are discussed by using nonlinear stochastic dynamics. General principles for the exploitation of nonlinear oscillators in energy harvesting that provide useful leads for the realization of micropower generators of practical interest are presented