Detonation driven shock wave interactions with perforated plates

The study of detonations and their interactions is vital for the understanding of the high-speed flow physics involved and the ultimate goal of controlling their detrimental effects. However, producing safe and repeatable detonations within the laboratory can be quite challenging, leading to the use of computational studies which ultimately require experimental data for their validation. The objective of this study is to examine the induced flow field from the interaction of a shock front and accompanying products of combustion, produced from the detonation taking place within a non-electrical tube lined with explosive material, with porous plates with varying porosities, 0.7–9.7%. State of the art high-speed schlieren photography alongside high-resolution pressure measurements is used to visualise the induced flow field and examine the attenuation effects which occur at different porosities. The detonation tube is placed at different distances from the plates' surface, 0–30 mm, and the pressure at the rear of the plate is recorded and compared. The results indicate that depending on the level of porosity and the Mach number of the precursor shock front secondary reflected and transmitted shock waves are formed through the coalescence of compression waves. With reduced porosity, the plates act almost as a solid surface, therefore the shock propagates faster along its surface

Hybrid: The Future of Construction Meetings in the Digital Age

Over the last few years, many construction companies have had to upheave traditional methods of construction meetings to adapt to rapidly changing COVID-19 safety and regulation protocols. For many, this has meant taking common in-person meetings (OAC, pre-construction, and design) and shifting them virtual. As companies continue to move forward in a post-pandemic climate, the question of whether they will continue with virtual meetings or revert to in-person meetings still lingers in the air. To get a better read on the future of construction meetings post-pandemic, a survey was sent to determine what most people prefer. A total of 21 responses were collected from commercial construction companies. 24% of the respondents were project engineers, 52% were project managers, 19% were upper management, and 5% were superintendents. Out of the 21 total respondents, 24% preferred virtual, 66% preferred in-person, and 10% preferred hybrid. While the responses leaned heavily toward an in-person meeting––the respondents were still mixed on the positives and drawbacks of each. Based on the reasoning, there is one conclusive takeaway–hybrid meetings, a mix of in-person and Zoom attendees, are here to stay

JPL Ephemeris Tapes E9510, E9511, and E9512

The first issue of JPL Ephemeris Tapes is described. These tapes carry the positions and velocities of the planets and of the Moon, plus nutations and nutation rates in longitude and obliquity, together with second and fourth modified differences, for the interval December 30, 1949, to January 5, 2000

Hydrothermal hydrolysis of starch with CO2 and detoxification of the hydrolysates with activated carbon for bio-hydrogen fermentation.

The imminent use of hydrogen as an energy vector establishes the need for sustainable production technologies based on renewable resources. Starch is an abundant renewable resource suitable for bio-hydrogen generation. It was hypothesised that starch hydrolysates from a large (250 mL) hydrothermal reactor could support bioH2 fermentation without inhibition by toxic byproducts.\ud \ud Starch was hydrolysed at high concentrations (40 200 g.L-1) in hot compressed water (HCW) with CO2 at 30 bar in a 250 mL reactor, the largest so far for polysaccharide hydrolysis, at 180 235 °C, 15 min. Hydrolysates were detoxified with activated carbon (AC) and tested in biohydrogen fermentations. The maximum yield of glucose was 548 g.kg starch 1 carbon at 200 °C. 5 hydroxymethyl furfural, the main fermentation inhibitor, was removed by AC to support 70% more hydrogen production than the untreated hydrolysates. The potential utilization of starch hydrolysates from HCW treatment for upscaled fermentations is promising

Studying the role of the strawberry Fra protein family in the flavonoid metabolism during fruit ripening

Strawberry fruits are highly appreciated worldwide due to their pleasant flavor and aroma and to the health benefits associated to their consumption. An important part of these properties is due to their content in secondary metabolites, especially phenolic compounds, of which flavonoids are the most abundant in the strawberry fruit. Although the flavonoid biosynthesis pathway is uncovered, little is known about its regulation. The strawberry Fra a (Fra) genes constitute a large family of homologs of the major birch pollen allergen Bet v 1 and for which no equivalents exist in Arabidopsis. Our group has shown that Fra proteins are involved in the formation of colored compounds in strawberries (Muñoz et al., 2010), which mainly depends on the production of certain flavonoids; that they are structurally homologs to the PYR/PYL/RCAR Arabidopsis ABA receptor, and that they are able to bind flavonoids (Casañal et al., 2013). With these previous results, our working hypothesis is that the Fra proteins are involved in the regulation of the flavonoids pathway. They would mechanistically act as the ABA receptor, binding a protein interactor and a ligand to regulate a signaling cascade and/or act as molecular carriers. The main objective of this research is to characterize the Fra family in strawberry and gain insight into their role in the flavonoid metabolism. By RNAseq expression analysis in ripening fruits we have identified transcripts for 10 members of the Fra family. Although expressed in all tissues analyzed, each family member presents a unique pattern of expression, which suggests functional specialization for each Fra protein. Then, our next approach was to identify the proteins that interact with Fras and their ligands to gain knowledge on the role that these proteins play in the flavonoids pathway. To identify the interacting partners of Fras we have performed a yeast two hybrid (Y2H) screening against cDNA libraries of strawberry fruits at the green and red stages. A protein that shares a 95% homology to the Heat stress transcription factor A-4-C like of Fragaria vesca (HSA4C) interacts specifically with Fra1 and not with other family members, which suggests functional diversification of Fra proteins in specific signaling pathways. The Y2H screening is not yet saturated, so characterization of other interacting proteins with other members of the Fra family will shed light on the functional diversity within this gene family. This research will contribute to gain knowledge on how the flavonoid pathway, and hence, the fruit ripening, is regulated in strawberry; an economically important crop but for which basic research is still very limited. References: Muñoz, C, et al. (2010). The Strawberry Fruit Fra a Allergen Functions in Flavonoid Biosynthesis. Molecular Plant, 3(1): 113–124. Casañal, A, et al (2013). The Strawberry Pathogenesis-related 10 (PR-10) Fra a Proteins Control Flavonoid Biosynthesis by Binding Metabolic Intermediates. Journal of Biological Chemistry, 288(49): 35322–35332.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Depósitos de zeolitas naturales de Cuba

Zeolite deposits exist in almost every province and region in Cuba. They are related to back-arc sequences from Cretaceous and Paleocene- Eocene volcanic arcs, and to top sequences of the axial arc zone from a Cretaceous volcanic arc, of which the latter developed only in the central part of Cuba. Due to the transformation of volcanic shards of medium-acid composition clinoptilolite, mordenite and less widespread montmorillonite originated. Clinoptilolite substitutes volcanic shards, and mordenite is formed after it

Epistemología social normativa: Fuller vs. Goldman

ResumenEste trabajo tiene como objetivo discutir dos versiones normativas de la Epistemología Social (es), cuyas propuestas iniciales surgidas hace 25 años dieron lugar al futuro establecimiento de una nueva tradición. Examinando sus propuestas uno puede encontrar que su interés en la normatividad, pese a diferencias substantivas, intenta llamar la atención de estudios filosóficos y sociales de la ciencia, a fin de analizar sus conexiones y ofrecerles un marco para pensar sus indagaciones sobre el estudio de la producción del conocimiento, retomando algunas tareas clásicas de la epistemología. Sin embargo, la es como perspectiva interdisciplinar más amplia trae a colación la pregunta del propio fin de la epistemología en nuestro tiempo. El trabajo se divide en tres partes; en la primera, damos un bosquejo del surgimiento de estas visiones; después, exponemos con más detalle cada una de ellas y, finalmente, cerramos con una pequeña reflexión.AbstractThe aim of this paper is to discuss two normative versions of Social Epistemology (se), whose initial approaches raised 25 years ago gave place to a new tradition. Revisiting the origin of each account one can find that their interest in normativity, despite their differences, tries to draw the attention of philosophical and social studies of science with the aim of analyzing their connections and provide them with a frame to take in their own inquiries of knowledge production the classical missions of epistemology. Yet, se as a broader interdisciplinary project raises the question of the role of epistemology in our time. The paper is divided in three parts. In the first, we give an account of the emergence of these visions, after that, we review each one of them in more detail and, finally, we end up with a brief comment