Cleanroom Contamination Identification Method Development

During fabrication, assembly, and testing of spacecraft and flight hardware it is vital to avoid contaminants that can cause degradation and could result in significant failure. Yet, there is no existing contamination monitoring method that provides the identity of airborne particles in a cleanroom facility. Knowing the particle identities, would allow scientists and engineers to determine the source of the contaminants and prevent setbacks before they occur or cause damage. Current cleanliness monitoring methods include airborne particle counters (APCs), fallout filters, and visual inspections. Particle counts from APCs are the primary metric used to define a cleanroom class and hence its level of cleanliness, but do not provide identification nor can they differentiate between large and small sizes of particles. In addition, using fallout filters is not a proactive, timely, or representative approach to cleanroom contamination monitoring because these samples are only retrieved after 30 days and are placed away from spacecraft processing to avoid interference with operations. In contrast, the forced air sampling method can collect a sample within an hour at any location required and provide results in less than a day. This system uses a cassette and filter sample medium to capture airborne particles which are then taken to a scanning electron microscope with energy dispersive spectroscopy (SEM/EDS) to identify and size the captured particles. Development of forced air sampling into an established laboratory capability will allow for fast sampling and routine identification of unknown contamination sources within the cleanroom. The test method development required market research for an air sampling cassette that increases sample collection efficiency and a filter with low enough background contamination to allow differentiation between a blank (control) and the collected sample. It was determined that a conductive black cassette and a polycarbonate filter were the best options. Conductive black cassettes, in comparison to the standard styrene, are manufactured using polypropylene filled with carbon. This makes the cassette conductive and minimizes the tendency of particles to stick to the wall of the cassette due to electrostatic force. In previous trials a mixed cellulose ester (MCE) filter was used to capture the contaminants, however the rougher surface of the filter contributed to entrapment of the particles within the filter structure and made it harder to identify the particles. In comparison, track etched polycarbonate filters have random cylindrical pores and a smooth surface which contributes to uniform sample distribution on the surface of the filter. Future work includes: testing the system using control samples to determine the efficiency and suitability of the medium, performing sample collection in various environments to establish ideal operating parameters and analyzing contaminant particles using SEM/EDS and assistant characterization techniques. Once fully developed, employing the forced air sampling method will help to prevent damage to spacecraft, avoid schedule delays, and allow for mission success

Suitability assessment of a continuous process combining thermo-mechano-chemical and bio-catalytic action in a single pilot-scale twin-screw extruder for six different biomass sources

A process has been validated for the deconstruction of lignocellulose on a pilot scale installation using six types of biomass selected for their sustainability, accessibility, worldwide availability, and differences of chemical composition and physical structure. The process combines thermo-mechano-chemical and bio-catalytic action in a single twin-screw extruder. Three treatment phases were sequentially performed: an alkaline pretreatment, a neutralization step coupled with an extraction–separation phase and a bioextrusion treatment. Alkaline pretreatment destructured the wall polymers after just a few minutes and allowed the initial extraction of 18–54% of the hemicelluloses and 9–41% of the lignin. The bioextrusion step induced the start of enzymatic hydrolysis and increased the proportion of soluble organic matter. Extension of saccharification for 24 h at high consistency (20%) and without the addition of new enzyme resulted in the production of 39–84% of the potential glucose

Economic consequences that can be generated due to migration in the short, medium and long term

El presente artículo es resultado de una investigación sociojurídica, descriptiva y documental de enfoque cualitativo. En este trabajo se abordan los problemas económicos asociados al fenómeno migratorio en la actualidad y su impacto en los lugares en que se presentan de forma masiva, en particular, teniendo como referente el proceso migratorio de Venezuela hacia Colombia. El objetivo principal se centra en identificar las consecuencias económicas de la migración en el corto, mediano y largo plazo y entre los principales resultados de la investigación se destacan los efectos que puede generar una migración masiva hacia un determinado territorio, en especial, como consecuencia de unas expectativas que no responden a la realidad económica y social del país que recibe amplio ingreso de esta población. Como consecuencia, en relación con la población migrante venezolana que llega a territorio colombiano se destaca el aspecto positivo en cuanto el acceso a la salud y el acceso a la educación, por otro lado, se resalta el impacto negativo en el país emisor, en la medida que se debilita la mano de obra trabajadora y profesional, lo que puede generar una afectación en diversos aspectos o perspectivas sociales en el marco del crecimiento y desarrollo de un territorio, entre otros aspectos económicos, académicos y culturales.Universidad Libre -- Facultad de Derecho, Ciencias Políticas y Sociales -- DerechoThis article is the result of socio-legal, descriptive and documentary research with a qualitative approach. This work addresses the economic problems associated with the migration phenomenon today and its impact on the places where these migratory flows occur on a massive scale, in particular, taking as a reference the migration process from Venezuela to Colombia. The main objective is to identify the economic consequences of the migratory phenomenon in the short, medium and long term. Among the main results of the research are the effects that a massive migration to a certain territory can generate, especially as a result of expectations that do not respond to the economic and social reality of the country that receives a large income from the migrant population. As consequences in relation to the Venezuelan migrant population that arrives in Colombian territory, the positive aspect in terms of access to health and access to education is highlighted, on the other hand, the negative impact on the sending country is highlighted, to the extent that working and professional labor is lost, which generates an impact, among other aspects, on its economic, academic and cultural growth

Sets of Fractional Operators and Some of Their Applications

This chapter presents one way to define Abelian groups of fractional operators isomorphic to the group of integers under addition through a family of sets of fractional operators and a modified Hadamard product, as well as one way to define finite Abelian groups of fractional operators through sets of positive residual classes less than a prime number. Furthermore, it is presented one way to define sets of fractional operators which allow generalizing the Taylor series expansion of a vector-valued function in multi-index notation, as well as one way to define a family of fractional fixed-point methods and determine their order of convergence analytically through sets

Programa de educación y sensibilización sobre la hipertensión arterial y factores predisponentes en los municipios de Yopal, Neiva (Huila) y Uribía.

Fotografias, Diagramas de barras, Cronograma,Tablas.En este trabajo se pretende conocer la importancia del conocimiento sobre La hipertensión arterial (HTA) la cual constituye un grave problema de salud pública, en vista de la elevada frecuencia con que se presenta esta afección y las innumerables enfermedades y muertes que ocasionan sus complicaciones, sean estas cardíacas, cerebrales o renales.This paper aims to determine the importance of knowledge about hypertension (HTN) which is a serious public health problem, in view of the high frequency with which this condition occurs and countless illnesses and deaths caused complications, are these heart, brain or kidney

Effect of Boriding on the Mechanical Properties of AISI 1045 Steel

Efecto en las propiedades mecánicas de un acero borurado 1045.Some mechanical properties of AISI 1045 borided steels were estimated in the present work. The boriding process was carried out by the powder pack method at 950°C with 8 h of treatment. The fatigue strength on borided notched specimens was evaluated with rotating bending tests (R=1) considering a stress concentration factor (Kt) of 2.53. Likewise, the presence of residual stresses in boride layers was established by the XRD technique. The Daimler-Benz Rockwell C test was used, also, to estimate the strength adhesion of the coated system. The results show a decrease in the fatigue strength of AISI borided steels due to the presence of high porosity in the layers. Finally, the Rockwell-C adhesion test showed no coating failure for the boride layer

The Stories We Tell

These voices you will hear in this edition of First Gen Voices were crafted and cultivated in a summer trip to the Dominican Republic, where our writers had the opportunity to workshop and reflect on their experiences being first-generation. The purpose? To share their work, mind, and feelings about the struggles and incredible experiences they have made. It is their strength, resilience, and love. Enjoy

Teleagro: iot applications for the georeferencing and detection of zeal in cattle

The loss of reproductive efficiency of animals and cattle rustling have become one of the main concerns of farmers. The decrease in reproductive efficiency is mainly due to the low percentage in heat detection. Reproductive efficiency is commonly measured by the interval between births, which affects the daily milk production of the cow during its productive life and the income associated with the sale of milk from its production, conditioning the profitability of the farmers. The zeal for its part consists of the theft of bovine cattle that usually is used for its commercialization, bringing considerable losses. According to figures from the Observatory of Human Rights and International Humanitarian Law of the Fundacion Colombia Ganadera, Fundagán, only during 2014 there were 164 cases of cattle rustling, resulting in the loss of 3,798 cattle throughout the country, which represents a loss for the producers of 15 billion of Colombian money. This project proposes the development of a technological platform that combines hardware, software and communications systems of the latest technology and with open standards to provide an economic and reliable solution to the Colombian and Latin American livestock industry. In Colombia, there is a history of products and prototypes that have been developed to alleviate this problem, no platforms of similar benefits have been found that are accessible to farmers in the country. In this article, the different stages developed to obtain a validated prototype with the beneficiary entity and their respective results are socialized

In vitro gas production kinetics and degradability of a diet for growing lambs: effect of fibrolytic enzyme products at different dose levels

The objective of this study was to evaluate the effects of three fibrolytic enzyme products (cellulase (CEL), xylanase (XYL) and a 1:1 mixture of CEL and XYL (MIX)) at three dose levels (0, 1 and 3 lL/0.5 g DM) on the in vitro fermentation of a diet for growing lambs. Bottles were incubated for 96 h at 39 C. A mathematical model was used to estimate the parameters describing the gas production (GP) curve (b, c and L). Dry matter degradability (DMD) and fibre (NDFD and ADFD) degradability were determined at the end of the incubation period. Metabolisable energy (ME) and short chain fatty acids (SCFA) were calculated at 24 h of incubation. The asymptotic GP (parameter b) was affected (p<0.02) by enzyme product and dose level, with a significant linear response (p<0.05). Dose level affected ME and SCFA with a significant linear (p<0.05) and quadratic (p<0.01) response. The interaction between enzyme product and dose level was significant (p<0.05) for cumulative GP up to 72 and 96 h of incubation, pH, ADFD and DMD. The results suggest that application of exogenous cellulases has the potential to alter asymptotic GP and degradability of ADF and DM of a diet for growing lambs, but most of the results depend on the interaction between enzyme product and dose level. Future studies are required to determine the ideal combination between enzyme product and dose level for optimal degradation of ruminant feeds