Optimization of Patterned Surfaces for Improved Superhydrophobicity Through Cost-Effective Large-Scale Computations

The growing need for creating surfaces with specific wetting properties, such as superhyrdophobic behavior, asks for novel methods for their efficient design. In this work, a fast computational method for the evaluation of patterned superhyrdophobic surfaces is introduced. The hydrophobicity of a surface is quantified in energy terms through an objective function. The increased computational cost led to the parallelization of the method with the Message Passing Interface (MPI) communication protocol that enables calculations on distributed memory systems allowing for parametric investigations at acceptable time frames. The method is demonstrated for a surface consisting of an array of pillars with inverted conical (frustum) geometry. The parallel speedup achieved allows for low cost parametric investigations on the effect of the fine features (curvature and slopes) of the pillars on the superhydophobicity of the surface and consequently for the optimization of superhyrdophobic surfaces.Comment: 18 pages, 18 figure

PLEISTOCENE PALAEOCLIMATIC EVOLUTION FROM AGIOS GEORGIOS CAVE SPELEOTHEM (KILKIS, N. GREECE)

Palaeoclimatic reconstruction in N. Greece has been investigated in this study, using stable isotope analyses and U/Th dating of a speleothem (stalactite) from the cave of Agios Georgios (Kilkis). Sampling sequence was followed in detail in order to obtain high resolution analysis of the proxy. Speleothem δ18O entirely depends on two factors: changes in the δ18O of the percolation waters (a proxy for local rainfall δ18O) and the temperature of water-calcite fractionation inside the cave (a proxy for outside air temperatures). During periods of relatively stable temperatures, δ13C shifts are caused principally by variations in soil CO2 input and physico-chemical processes inside the cave. More important processes affect the δ13C signal of speleothem inside the cave are length of flow path and rates of CO2 degassing.The lower δ13C calcite values indicate greater respiratory activity of soils under wetter conditions. The stalagmite layers were dated through U/Th geochronological method, which places the carbonate precipitation in Middle Pleistocene (630-300ka BP). The isotopic composition of the layers was used in combination with the dating results to reconstruct the evolution of the area of Kilkis. Correlation with global climatic records shows that major climatic transitions that influenced northern hemisphere seem to have also affected the region of N. Greece

PLEISTOCENE PALAEOCLIMATIC EVOLUTION FROM AGIOS GEORGIOS CAVE SPELEOTHEM (KILKIS, N. GREECE)

Palaeoclimatic reconstruction in N. Greece has been investigated in this study, using stable isotope analyses and U/Th dating of a speleothem (stalactite) from the cave of Agios Georgios (Kilkis). Sampling sequence was followed in detail in order to obtain high resolution analysis of the proxy. Speleothem δ18O entirely depends on two factors: changes in the δ18O of the percolation waters (a proxy for local rainfall δ18O) and the temperature of water-calcite fractionation inside the cave (a proxy for outside air temperatures). During periods of relatively stable temperatures, δ13C shifts are caused principally by variations in soil CO2 input and physico-chemical processes inside the cave. More important processes affect the δ13C signal of speleothem inside the cave are length of flow path and rates of CO2 degassing.The lower δ13C calcite values indicate greater respiratory activity of soils under wetter conditions. The stalagmite layers were dated through U/Th geochronological method, which places the carbonate precipitation in Middle Pleistocene (630-300ka BP). The isotopic composition of the layers was used in combination with the dating results to reconstruct the evolution of the area of Kilkis. Correlation with global climatic records shows that major climatic transitions that influenced northern hemisphere seem to have also affected the region of N. Greece

The normal field instability under side-wall effects: comparison of experiments and computations

We consider a single spike of ferrofluid, arising in a small cylindrical container, when a vertically oriented magnetic field is applied. The height of the spike as well as the surface topography is measured experimentally by two different technologies and calculated numerically using the finite element method. As a consequence of the finite size of the container, the numerics uncovers an imperfect bifurcation to a single spike solution, which is forward. This is in contrast to the standard transcritical bifurcation to hexagons, common for rotational symmetric systems with broken up-down symmetry. The numerical findings are corroborated in the experiments. The small hysteresis observed is explained in terms of a hysteretic wetting of the side wall.Comment: accepted to New Journal of Physic

Limit overturning moment chuck

Limited memory capacity is one of the major constraints in Delay Tolerant Wireless Sensor Networks. Efficient management of the memory is critical to the performance of the network. This paper proposes a novel buffer management algorithm, SmartGap, a Quality of Information (QoI) targeted buffer management algorithm. That is, in a wireless sensor network that continuously measures a parameter which changes over time, such as temperature, the value of a single packet is governed by an estimation of its contribution to the recreation of the original signal. Attractive features of SmartGap include a low computational complexity and a simplified reconstruction of the original signal. An analysis and simulations in which the performance of SmartGap is compared with the performance of several commonly used buffer management algorithms in wireless sensor networks are provided in the paper. The simulations suggest that SmartGap indeed provides significantly improved QoI compared the other evaluated algorithms.QC 20150605</p

Spontaneous regression of a true splenic cyst: a case report and review of the literature

Splenic cysts are rare clinical findings, detected due to derivative symptoms or as a random discovery in abdominal imaging. Although there still remains controversy as to their optimal treatment, bigger secondary cysts should be treated surgically. However, spontaneous regression may be observed in cysts with a diameter smaller than 4 cm. In these cases, expectant treatment is preferable. We report, herein, a single case of a splenic cyst in an adult woman, who reported minor symptoms despite the size of the lesion and who demonstrated a possible almost total regression of the cyst within a ten-year period, accompanying with review of the most recent literature

Effect of Direct Oral Anticoagulant, Patient, and Surgery Characteristics on Clinical Outcomes in the Perioperative Anticoagulation Use for Surgery Evaluation Study.

Introduction  The Perioperative Anticoagulation Use for Surgery Evaluation (PAUSE) Study assessed a standardized perioperative management strategy in patients with atrial fibrillation who were taking a direct oral anticoagulant (DOAC) and required an elective surgery or procedure. The aim of this substudy is to analyze the safety of this management strategy across different patient subgroups, according to four presurgical variables: (1) DOAC type and dose, (2) surgery/procedure bleed risk, (3) patient renal function, and (4) age. Methods  Clinical outcomes analyzed included major bleeding (MB), arterial thromboembolism, any bleeding, and any thromboembolism. We used descriptive statistics to summarize clinical outcomes, where the frequency, proportion, and 95% confidence interval were reported. Fisher\u27s exact tests were used for testing the hypothesis of independence between the clinical outcome and patient characteristic, where the test p -values were reported. Results  There were 3,007 patients with atrial fibrillation requiring perioperative DOAC management. There was no significant difference in bleeding or thromboembolic outcomes according to DOAC type/dose regimen, renal function, or patient age. The rate of MB was significantly higher with high bleed risk procedures than low bleed risk procedures in apixaban-treated patients (2.9 vs. 0.59%; p  \u3c 0.01), but not in dabigatran-treated patients (0.88 vs. 0.91%; p  = 1.0) or rivaroxaban-treated patients (2.9 vs. 1.3%; p  = 0.06). The risk for thromboembolism did not differ according to surgery/procedure-related bleed risk. Conclusion  Our results suggest that in DOAC-treated patients who received standardized perioperative management, surgical bleed risk is an important determinant of bleeding but not thromboembolic outcomes, although this finding was not consistent across all DOACs. There were no differences in bleeding and thromboembolism according to DOAC type and dose, renal function, or age

Diffuse anorectal melanoma; review of the current diagnostic and treatment aspects based on a case report

Primary anorectal melanoma is a rare and aggressive disease. Patients commonly complain for changes in bowel habits and rectal bleeding, and proctoscopically they mostly appear as non pigmented or lightly pigmented polypoid lesions. Such a lesion should always raise a high index of suspicion in any gastroenterologist or surgeon to prompt surgery, since early radical excision is the only treatment option