Hybrid Manufacturing: Integrating Direct Write and Stereolithography

A commercial stereolithography (SL) machine was modified to integrate fluid dispensing or direct-write (DW) technology with SL in an integrated manufacturing environment for automated and efficient hybrid manufacturing of complex electrical devices, combining threedimensional (3D) electrical circuitry with SL-manufactured parts. The modified SL system operates similarly to a commercially available machine, although build interrupts were used to stop and start the SL build while depositing fluid using the DW system. An additional linear encoder was attached to the SL platform z-stage and used to maintain accurate part registration during the SL and DW build processes. Individual STL files were required as part of the manufacturing process plan. The DW system employed a three-axis translation mechanism that was integrated with the commercial SL machine. Registration between the SL part, SL laser and the DW nozzle was maintained through the use of 0.025-inch diameter cylindrical reference holes manufactured in the part during SL. After depositing conductive ink using DW, the SL laser was commanded to trace the profile until the ink was cured. The current system allows for easy exchange between SL and DW in order to manufacture fully functional 3D electrical circuits and structures in a semi-automated environment. To demonstrate the manufacturing capabilities, the hybrid SL/DW setup was used to make a simple multi-layer SL part with embedded circuitry. This hybrid system is not intended to function as a commercial system, it is intended for experimental demonstration only. This hybrid SL/DW system has the potential for manufacturing fully functional electromechanical devices that are more compact, less expensive, and more reliable than their conventional predecessors, and work is ongoing in order to fully automate the current system.Mechanical Engineerin

Variability of the Sea Surface Temperature Around Cuba

Space and time variability of sea surface temperature in oceanic and shelf waters of Cuba were examined using the Advanced Very High Resolution Radiometer (AVHRR) sensors flown on satellites operated by the National Oceanic and Atmospheric Administration from February 1995 to August 2001. Statistics at 90 specific time series stations around Cuba were extracted from the AVHRR images to characterize shelf and oceanic waters using the long-term overall mean, minimum, and maximum sea surface temperature (SST) values. Shelf and oceanic waters reached SST maxima (29.5-30.5°C) in August. Waters off southern and western Cuba reached slightly higher temperatures than those off the northeast in the Old Bahamas Channel; waters along the northern coast of Cuba were about 1°C cooler on average than those along the southern coast. Oceanic waters around Cuba experienced minima (24.5-25.5°C) in February-March, about a month after shelf waters. Only minor regional differences in maximum temperatures were observed in shelf areas. Shelf regions around Cuba have lower annual average SSTs than adjacent oceanic waters, and the range of monthly average SST of shelf waters exceeded that of oceanic waters by 3°C, with the largest differences observed during winter. Shelf waters also cooled down at \u3e0.04°C/d, or twice as fast as oceanic waters (0.02°C/d) by action of sensible heat and evaporative losses. Shelf waters also warmed up at rates exceeding 0.06°C/d, which was two to three times faster than oceanic waters (0.02-0.03°C/d). SST anomalies were slightly positive between February 1995 and February 1999 and slightly negative from October 1999 to August 2001. In summer of 1995, 1997, and 1998, coral bleaching was observed in northern and southern reefs of Cuba. Summer anomalies \u3e1°C occurred in May 1995 and August 1997, which may have contributed to the coral bleaching

Influencia del carbón activado en la filtración del agua del río Muyurina para mantener la resistencia del concreto, Ayacucho 2020

En este trabajo de investigación se tuvo como objetivo dar a conocer el uso del carbón activado para la filtración del agua del río Muyurina y ver la influencia que tienen estas aguas filtradas en la resistencia del concreto, ya que en la actualidad existen lugares que aún no cuentan con agua potable y optan por usar recursos hídricos de los ríos para usarlo en la construcción de sus viviendas por ello esto ayudaría en mejorar la calidad del agua del río para poder usarlos en la mezcla del concreto en el valle de Muyurina, distrito de Tambillo, Ayacucho. La metodología empleada en esta investigación fue experimental con enfoque cuantitativo, ya que se realizaron análisis físicos y químicos en un laboratorio certificado al agua del río Muyurina y a las muestras de aguas filtradas con diferentes dosificaciones de carbón activado (filtro A=31.91%, filtro B=37.25% y filtro C=42.55%), también se hicieron ensayos de compresión al concreto mezclado con las muestras de las diferentes aguas filtradas con un diseño de mezcla patrón para un F’c=210 kg/cm2 a los 7 y 14 días, se tuvo como último ensayo el tiempo de fraguado inicial por medio de la resistencia a la penetración. Mediante los ensayos realizados se comprobó que el uso de filtros de carbón activado mejora la calidad del agua del río Muyurina y a su vez el uso de estas aguas filtradas con diferentes porcentajes de carbón activado mejora la resistencia del concreto en proporción a la calidad de aguas filtradas obtenidas y usadas para la mezcla del concreto y mejorando de la misma forma en el ensayo de tiempo de fraguado del concreto. Finalmente se sugirió que se empleen más estudios sobre este tema ya que se podría usar como una alternativa para la obtención del recurso hídrico para la construcción sin riesgos de perjudicar la calidad del concreto en zonas que no cuentan con un sistema de agua potable

Propuesta de un sistema de gestión de inventarios basado en el método PEPS para una Empresa Comercial de Productos Perecibles

Una gestión de inventarios eficiente ayudará a tener un correcto manejo de los productos en las empresas y aplicar métodos de control traerá como consecuencia un incremento relativo en la liquidez de la empresa, por ello es que en la presente investigación se realiza la propuesta de un sistema de gestión de inventarios, en donde a través de una guía de observación llegamos a tener el diagnóstico la situación actual, de acuerdo al análisis de prevalencia, se concluye que la dimensión con mayor riesgo es la planificación de políticas con un porcentaje del 78%, seguido de métodos contables y administrativos que representa un 69% y por último el control físico representa un 54%. Es así que proponemos un sistema de gestión de inventarios basado en el Método PEPS para poder mejorar los métodos de control en la empresa.JULIACAEscuela Profesional de ContabilidadContabilidad genera

G Protein Subunit Dissociation and Translocation Regulate Cellular Response to Receptor Stimulation

We examined the role of G proteins in modulating the response of living cells to receptor activation. The response of an effector, phospholipase C-β to M3 muscarinic receptor activation was measured using sensors that detect the generation of inositol triphosphate or diacylglycerol. The recently discovered translocation of Gβγ from plasma membrane to endomembranes on receptor activation attenuated this response. A FRET based G protein sensor suggested that in contrast to translocating Gβγ, non-translocating Gβγ subunits do not dissociate from the αq subunit on receptor activation leading to prolonged retention of the heterotrimer state and an accentuated response. M3 receptors with tethered αq induced differential responses to receptor activation in cells with or without an endogenous translocation capable γ subunit. G protein heterotrimer dissociation and βγ translocation are thus unanticipated modulators of the intensity of a cell's response to an extracellular signal

Applications of isothermal titration calorimetry - the research and technical developments from 2011 to 2015

Isothermal titration calorimetry is a widely used biophysical technique for studying the formation or dissociation of molecular complexes. Over the last 5years, much work has been published on the interpretation of isothermal titration calorimetry (ITC) data for single binding and multiple binding sites. As over 80% of ITC papers are on macromolecules of biological origin, this interpretation is challenging. Some researchers have attempted to link the thermodynamics constants to events at the molecular level. This review highlights work carried out using binding sites characterized using x-ray crystallography techniques that allow speculation about individual bond formation and the displacement of individual water molecules during ligand binding and link these events to the thermodynamic constants for binding. The review also considers research conducted with synthetic binding partners where specific binding events like anion-π and π-π interactions were studied. The revival of assays that enable both thermodynamic and kinetic information to be collected from ITC data is highlighted. Lastly, published criticism of ITC research from a physical chemistry perspective is appraised and practical advice provided for researchers unfamiliar with thermodynamics and its interpretation

In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

TXS 0506+056 with Updated IceCube Data

Past results from the IceCube Collaboration have suggested that the blazar TXS 0506+056 is a potential source of astrophysical neutrinos. However, in the years since there have been numerous updates to event processing and reconstruction, as well as improvements to the statistical methods used to search for astrophysical neutrino sources. These improvements in combination with additional years of data have resulted in the identification of NGC 1068 as a second neutrino source candidate. This talk will re-examine time-dependent neutrino emission from TXS 0506+056 using the most recent northern-sky data sample that was used in the analysis of NGC 1068. The results of using this updated data sample to obtain a significance and flux fit for the 2014 TXS 0506+056 "untriggered" neutrino flare are reported