Cutting load capacity of end mills with complex geometry

Cutting load capacity of cemented carbide end mills with high length-to-diameter ratios is determined from critical geometric and loading parameters, including a stress concentration factor (SCF) to account for serrated edges, which is determined by finite element analysis. Tensile strengths are characterised using a statistical Weibull analysis from 4-point bend tests of cemented carbide blanks of two different diameters. The approach is used to predict probability of survival for cutters under different loading conditions. Results are compared to measured failure cutting loads under service conditions as well as to those measured in static three point bend tests

Effects of Mev Si Ions and Thermal Annealing on Thermoelectric and Optical Properties of SiO2/SiO2+Ge Multi-nanolayer thin Films

AbstractThermoelectric generator devices have been prepared from 200 alternating layers of SiO2/SiO2+Ge superlattice films using DC/RF magnetron sputtering. The 5 MeV Si ionsbombardmenthasbeen performed using the AAMU Pelletron ion beam accelerator to formquantum dots and / or quantum clusters in the multi-layer superlattice thin films to decrease the cross-plane thermal conductivity, increase the cross-plane Seebeck coefficient and increase the cross-plane electrical conductivity to increase the figure of merit, ZT. The fabricated devices have been annealed at the different temperatures to tailor the thermoelectric and optical properties of the superlattice thin film systems. While the temperature increased, the Seebeck coefficient continued to increase and reached the maximum value of -25μV/K at the fluenceof 5x1013 ions/cm2. The decrease in resistivity has been seen between the fluence of 1x1013 ions/cm2 and 5x1013 ions/cm2. Transport properties like Hall coefficient, density and mobility did not change at all fluences. Impedance spectroscopy has been used to characterize the multi-junction thermoelectric devices. The loci obtained in the C*-plane for these data indicate non-Debye type relaxation displaying the presence of the depression parameter

A Structured Blood Conservation Program in Pediatric Cardiac Surgery

OBJECTIVE: The limitation of alternative transfusion practices in infants increases the benefits of blood conservation. We analyzed the efficacy of a structured program to reduce transfusions and transfusion-associated complications in cardiac surgery PATIENTS AND METHODS: Our pediatric surgery database was reviewed retrospectively, comparing outcomes from two different time periods, after the implementation of an effective blood conservation program beginning in March 2014. A total of 214 infants (8.1±3.4 months) who underwent biventricular repair utilizing CPB (Group 1 – Blood conservation) were studied in a 12-month period (March 2014-February 2015) after the implementation of the new program, and compared with 250 infants (7.91±3.2 months) (Group 2 – Control-No blood conservation) of the previous 12 – month period (March 2013-February 2014). RESULTS: The proportion of patients transfused with red blood cells was 75.2% (N=188) in control group and reduced by 16.4% in the study group (58.8% – 126 patients, p CONCLUSIONS: These findings, in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in pediatric cardiac operations. Circuit miniaturization, ultrafiltration, and reduced postoperative bleeding, presumably secondary to higher fibrinogen and other coagulation factor levels, contributed to this outcome

A Cardiopulmonary Bypass Based Blood Management Strategy in Adult Cardiac Surgery

BACKGROUND: Despite the recent introduction of a number of technical and pharmacologic blood conservation measures, bleeding and allogeneic transfusion remain persistent problems in open-heart surgical procedures. Efforts should be made to decrease or completely avoid transfusions to avoid these negative reactions. METHODS: Our coronary artery bypass grafting database was reviewed retrospectively and a total of 243 patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) were studied in a 12-month period (January-December 2016) after the implementation of the new program, and compared with 275 patients of the previous 12-month period.All the staff involved in the care of the patients were educated about the risks and benefits of blood transfusions and the new transfusion guidelines in a 45-min training. We revised our guidelines for transfusions based on the STS. A transfusion log was created. Reduction in IV fluid volume was targeted. CPB circuitry was redesigned to achieve significantly less prime volume. Results: The proportion of patients transfused with red blood cells was 56% (n =154) in the control group and reduced by 26.8% in the study group (29.2%; 71 patients; P \u3c .01). Blood transfusion rate (1.7 +./- 1/3.05 +./- 1 units), postoperative hemorrhage (545 +./- 50/ 775 +./- 55 mL), respiratory support duration (12.4 +./- 7/16.8 +./- 8 h) and ICU stay (2.2+./-1.1/ 3.5+./-1.2 days) were significantly better in the blood conservation group. Conclusion: These findings, in addition to risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in adult cardiac operations

Local Monte Carlo estimation methods in the solution of global illumination equation

In this article, we consider local estimations of the Monte Carlo method for solving the equation of the global illumination. The local estimations allow directly calculating the luminance at a predetermined point, in a given direction for an arbitrary bidirectional reflectance distribution function (BRDF). Thus, there is no need to construct the map of the illumination. Thereby it is much more effective than direct modeling or the method of finite element. The use in lighting calculations of the object described by the spherical harmonics is also discussed in the article

Thermoelectric Figures of Merit of Zn4Sb3 and Zrnisn-based Half-heusler Compounds Influenced by Mev Ion-beam Bombardments

AbstractSemiconducting β-Zn4Sb3 and ZrNiSn-based half-Heusler compound thin films with applications as thermoelectric (TE) materials were prepared using ion beam assisted deposition (IBAD). High-purity solid zinc (Zn) and antimony (Sb) were evaporated by electron beam to grow the β-Zn4Sb3 thin film while high-purity zirconium (Zr) powder and nickel (Ni) tin (Sn) powders were evaporated by electron beam to grow the ZrNiSn-based half-Heusler compound thin film. Rutherford backscattering spectrometry (RBS) was used to analyze the composition of the thin films. The grown thin films were subjected to 5 MeV Si ions bombardment for generation of nanostructures in the films. We measured the thermal conductivity, Seebeck coefficient, and electrical conductivity of these two systems before and after 5 MeV Si ions beam bombardment. The two material systems have been identified as promising TE materials for the application of thermal-to-electrical energy conversion, but the efficiency still limits their applications. The electronic energy deposited due to ionization in the track of MeV ion beam couldcause localized crystallization. The nanostructures produced by MeV ion beam can cause significant change in both the electrical and the thermal conductivity of thin films, thereby improving the efficiency. We used the 3ω-method (3rd harmonic) measurement system to measure the cross-plane thermal conductivity, the van der Pauw measurement system to measure the electrical conductivity, and the Seebeck-coefficient measurement system to measure the cross-plane Seebeck coefficient. The thermoelectric figures of merit of the two material systems were then derived by calculations using the measurement results. The MeV ion-beam bombardment was found to decrease the thermal conductivity of thin films and increase the efficiency of thermal-to-electrical energy conversion

Fractional Ostrowski type inequalities for functions of bounded variaton with two variables

We first establish some fractional equalities for functions of bounded variation with two variables. Then we derive some fractional Ostrowski and Trapezoid type inequalities for functions of bounded variation with two variables. In addition, we give some Midpoint inequalities as special cases of our main results.WOS:0005415092000122-s2.0-8508947064

Multipartite minimum uncertainty products

In our previous work we have found a lower bound for the multipartite uncertainty product of the position and momentum observables over all separable states. In this work we are trying to minimize this uncertainty product over a broader class of states to find the fundamental limits imposed by nature on the observable quantites. We show that it is necessary to consider pure states only and find the infimum of the uncertainty product over a special class of pure states (states with spherically symmetric wave functions). It is shown that this infimum is not attained. We also explicitly construct a parametrized family of states that approaches the infimum by varying the parameter. Since the constructed states beat the lower bound for separable states, they are entangled. We thus show that there is a gap that separates the values of a simple measurable quantity for separable states from entangled ones and we also try to find the size of this gap.Comment: 18 pages, 5 figure

Evolution of Conversations in the Age of Email Overload

Email is a ubiquitous communications tool in the workplace and plays an important role in social interactions. Previous studies of email were largely based on surveys and limited to relatively small populations of email users within organizations. In this paper, we report results of a large-scale study of more than 2 million users exchanging 16 billion emails over several months. We quantitatively characterize the replying behavior in conversations within pairs of users. In particular, we study the time it takes the user to reply to a received message and the length of the reply sent. We consider a variety of factors that affect the reply time and length, such as the stage of the conversation, user demographics, and use of portable devices. In addition, we study how increasing load affects emailing behavior. We find that as users receive more email messages in a day, they reply to a smaller fraction of them, using shorter replies. However, their responsiveness remains intact, and they may even reply to emails faster. Finally, we predict the time to reply, length of reply, and whether the reply ends a conversation. We demonstrate considerable improvement over the baseline in all three prediction tasks, showing the significant role that the factors that we uncover play, in determining replying behavior. We rank these factors based on their predictive power. Our findings have important implications for understanding human behavior and designing better email management applications for tasks like ranking unread emails.Comment: 11 page, 24th International World Wide Web Conferenc

Fraunhofer diffraction description in the approximation of the light field theory

The wavelength is that natural scale that determines the applicability domains of the ray approximation and the wave approximation of light. If the change of the radiation power spatial density is significant at the wavelength scale, we deal with the light diffraction phenomenon, which is a subject to the wave optics. Let us consider the diffraction phenomenon at the diaphragm. It is possible to distinguish the near zone with significant wave inhomogeneities (i.e. the Fresnel zone) and the far Fraunhofer diffraction zone, in which the wave becomes close to homogeneous (the so-called quasi-homogeneous) and the ray approximation is possible. The problem is that there is no explicit relationship between the radiance of the rays before and after diaphragm. Method for determining the boundary conditions for the radiance in the Fraunhofer zone through the radiance of the incident radiation is proposed in the paper. This approach for computing the radiance field in the Fraunhofer zone can be generalized to other problems of optics, thereby providing the possibility of using computationally efficient ray-approximation-based methods to determine the light fields