High-performance thermal emitters based on laser engineered metal surfaces

Effective thermal management is of paramount importance for all high-temperature systems operating under vacuum. Cooling of such systems relies mainly on radiative heat transfer requiring high spectral emissivity of surfaces, which is strongly affected by the surface condition. Pulsed laser structuring of stainless steel in air resulted in the spectral hemispherical emissivity values exceeding 0.95 in the 2.5–15 µm spectral region. The effects of surface oxidation and topography on spectral emissivity as well as high temperature stability of the surface structures were examined. High performance stability of the laser textured surfaces was confirmed after thermal aging studies at 320°C for 96 hour

Optimization of the secondary electron yield of laser-structured copper surfaces at room and cryogenic temperature

Electron cloud (e-cloud) mitigation is an essential requirement for proton circular accelerators in order to guarantee beam stability at a high intensity and limit the heat load on cryogenic sections. Laser-engineered surface structuring is considered a credible process to reduce the secondary electron yield (SEY) of the surfaces facing the beam, thus suppressing the e-cloud phenomenon within the high luminosity upgrade of the LHC collider at CERN (HL-LHC). In this study, the SEY of Cu samples with different oxidation states, obtained either through laser treatment in air or in different gas atmospheres or via thermal annealing, has been measured at room and cryogenic temperatures and correlated with the surface composition measured by x-ray photoelectron spectroscopy. It was observed that samples treated in nitrogen display the lowest and more stable SEY values, correlated with the lower surface oxidation. In addition, the surface oxide layer of air-treated samples charges upon electron exposure at a low temperature, leading to fluctuations in the SEY

Modelling laser modified secondary electron yield response of surfaces

Electron clouds hinder the operation of particle accelerators. In the Large Hadron Collider (LHC), the copper beam screens are located within close proximity to the beam path, resulting in beam-induced electron multipacting, which is the main source of electron cloud formation. Conditions for multipacting are encountered when such surfaces have a Secondary Electron Yield (SEY) greater than unity. Roughening the surface through laser processing offers an effective solution for reducing secondary electrons. Laser ablation leaves behind a complex rough, multi-scale geometrical surface with an altered chemical composition. Current models often over-simplify the geometry, do not have sufficient experimental data to derive input parameters, and exclude SEY-reducing mechanisms such as the surface chemistry. Leading to electron-matter interactions which do not resemble that of a real surface. Here, this complex surface is studied on copper used in the LHC, and the influence of microgeometry, inhomogeneous nanostructure and complex surface chemistry on the SEY is investigated. A novel, improved model is proposed that characterises these sophisticated structures, enabling the efficient design of surfaces to reduce SEY. To validate the model, samples were made using a variety of laser parameters. Modelling insights revealed that secondary electron suppression is not only caused by the microgeometry but also the nanostructure and chemical modification play a role. Contrary to the conventional theory, high aspect ratio structures are not necessarily required for effective SEY reduction. Currently, the model is applicable to a variety of surface morphologies and could be employed for other materials

Design and Implementation of Flower Export Consortium in Ceará State, Brazil

 The Brazilian presence in international commerce, despite the regional leadership in Latin America and the global importance of Brazil as an emerging economy, is quite limited, reaching only 1% of the world’s total trade. Nevertheless, the agribusiness sector is responsible for half of the country’s export and Brazil is the world leader in sugar, coffee, orange juice, tobacco, soybean and beef export. Export growth is considered to be a key factor for the economic development of the country and many governmental programs are being carried out. The Ministry of Agriculture, Livestock and Food Supply (MAPA), through its Cooperative Department (DENACOOP), has joined these efforts. The DENACOOP export consortia program is focused on building strategic alliance in agribusiness production chain. After successful experiences in implementing in grain and honey sector, an applied research project was set up focusing on a flower production chain in Northeast of Brazil, which has the potential to improve socio-economic indicators of a low income region. To carry out the project the Federal University of Viçosa research team has developed a design and implemen-tation procedure, which was based on structuring and translating the requirements of organizations and producers into contract’s clause. The consortium main clauses established that all the purchase and sale of agricultural inputs, the internal and external seedling market, roses, ornamental and vase flowers will be done together. The commercialization and the post-harvest activities will be done through the creation of a distribution center. Recently flower producers have signed the export consortium contract. The consortium is expected to improve the competitiveness of the flower production chain in the state of Ceará and increase the current minor importance of Brazil in the international flower trade

Tratamiento y control de la diabetes con intervención de estilo de vida en pacientes ambulatorios: Serie de Casos y Actualización: Diabetes treatment and control using lifestyle intervention in outpatient setting: Case Series and Update

The prevalence of diabetes demands the identification of more efficient long-term methods to achieve good patient control. This paper reports the progress of 4 patients diagnosed with previously poorly controlled diabetes and prediabetes with comorbidities that were attended in an outpatient clinic, they received orientation regarding lifestyle change and were instructed to increase consumption of dietary fiber and physical activity. Body composition and biochemical markers were followed and changes were reported. In a 5 month period Patient 1 achieved criterion for controlled diabetes and was able to suspend oral hypoglycemic agents, reducing his body weight by 10%. Within a 8 week period Patient 2 experienced a 50% decrease of HOMA IR and was able to achieve criteria of controlled diabetes. Furthermore a 3 kg increase in lean body mass and a 4 kg body weight decrease were documented. These findings were accompanied by a 23% and 38% decrease in total cholesterol and triglycerides respectively. Patient 3 achieved criteria for type 2 diabetes remission within a 18 month time span(Inicial HBA1C 11.4% Final HBA1C 5.3). Patient 4 progressed to remission of prediabetes and a decrease of 5.9% in total body weight in a 3 month period.Las cifras de prevalencia de la diabetes nos obligan a identificar métodos más eficientes a largo plazo para lograr el buen control de los pacientes. En este trabajo se reporta el curso clínico de 4 pacientes con diagnóstico de diabetes y prediabetes quienes fueron atendidos en la consulta externa y recibieron asistencia no intensiva para cambio de comportamiento en salud, orientada a aumentar consumo de fibra alimentaria y a aumentar sus niveles de actividad física.  Se reportan cambios en indicadores bioquímicos y antropométricos. El paciente 1 en 5 meses logró suspender hipoglucemiantes orales, disminuyendo un 10% de su peso corporal y logrando criterios de prediabetes (remisión parcial). El paciente 2 en un período de 8 semanas logró alcanzar criterios de diabetes controlada, disminuyendo en 50% el índice HOMA IR.  Además, se documentó pérdida de 4 kg de masa grasa corporal con ganancia de 3 kg de masa magra.  Lo anterior se acompañó de una disminución del 23% del colesterol total y 38% de triglicéridos. La paciente 3 alcanzó criterios de remisión de DM2 durante un seguimiento de 18 meses(HBA1C 11.4% inicial y 5.3% final). La paciente 4 evolucionó a remisión de prediabetes y disminución de 5.9% de peso corporal total en un periodo de 3 meses

Identification of hepatitis a virus mimotopes by phage display, antigenicity and immunogenicity

A phage-displayed peptide approach was used to identify ligands mimicking antigenic determinants of hepatitis A virus (HAV) for the first time. Bacteriophages displaying HAV mimotopes were isolated from a phage-display peptide library by affinity selection on serum antibodies from hepatitis A patients. Selected phage-peptides were screened for reactivity with sera from HAV infected patients and healthy controls. Four cloned peptides with different sequences were identified as mimotopes of HAV; three of them showed similarity in their amino acid sequences with at least one of the VP3 and VP1 antigenic proteins of HAV. One clone was recognised by 92% of the positive sera. The phagotopes competed effectively with HAV for absorption of anti-HAV-specific antibodies in human sera, as determined by ELISA. The four phage clones induced neutralising anti-HAV antibodies in immunised mice. These results demonstrate the potential of this method to elucidate the disease related epitopes of HAV and to use these mimotopes in diagnostic applications or in the development of a mimotope-based hepatitis A vaccine without the necessity of manipulation of the virus

Genomic, Lipidomic and Metabolomic Analysis of Cyclooxygenase-null Cells: Eicosanoid Storm, Cross Talk, and Compensation by COX-1

AbstractThe constitutively-expressed cyclooxygenase 1 (COX-1) and the inducible COX-2 are both involved in the conversion of arachidonic acid (AA) to prostaglandins (PGs). However, the functional roles of COX-1 at the cellular level remain unclear. We hypothesized that by comparing differential gene expression and eicosanoid metabolism in lung fibroblasts from wild-type (WT) mice and COX-2-/- or COX-1-/- mice may help address the functional roles of COX-1 in inflammation and other cellular functions. Compared to WT, the number of specifically-induced transcripts were altered descendingly as follows: COX-2-/->COX-1-/->WT+IL-1β. COX-1-/- or COX-2-/- cells shared about 50% of the induced transcripts with WT cells treated with IL-1β, respectively. An interactive “anti-inflammatory, proinflammatory, and redox-activated” signature in the protein–protein interactome map was observed in COX-2-/- cells. The augmented COX-1 mRNA (in COX-2-/- cells) was associated with the upregulation of mRNAs for glutathione S-transferase (GST), superoxide dismutase (SOD), NAD(P)H dehydrogenase quinone 1 (NQO1), aryl hydrocarbon receptor (AhR), peroxiredoxin, phospholipase, prostacyclin synthase, and prostaglandin E synthase, resulting in a significant increase in the levels of PGE2, PGD2, leukotriene B4 (LTB4), PGF1α, thromboxane B2 (TXB2), and PGF2α. The COX-1 plays a dominant role in shifting AA toward the LTB4 pathway and anti-inflammatory activities. Compared to WT, the upregulated COX-1 mRNA in COX-2-/- cells generated an “eicosanoid storm”. The genomic characteristics of COX-2-/- is similar to that of proinflammatory cells as observed in IL-1β induced WT cells. COX-1-/- and COX-2-/- cells exhibited compensation of various eicosanoids at the genomic and metabolic levels

First accelerator test of vacuum components with laser-engineered surfaces for electron-cloud mitigation

Electron cloud mitigation is an essential requirement for high-intensity proton circular accelerators. Among other solutions, laser engineered surface structures (LESS) present the advantages of having potentially a very low secondary electron yield (SEY) and allowing simple scalability for mass production. Two copper liners with LESS have been manufactured and successfully tested by monitoring the electron cloud current in a dipole magnet in the SPS accelerator at CERN during the 2016 run. In this paper we report on these results as well as the detailed experiments carried out on samples—such as the SEY and topography studies—which led to an optimized treatment in view of the SPS test and future possible use in the HL-LHC