Studying joint influence of a number of factors on borehole cleaning

Studying the behavior of cuttings transport under various conditions using experimental observations and computational fluid dynamics is the main method for analyzing the influence of cuttings, fluid and operating parameters on well cleaning. Despite the existing abundant models and recommendations of researchers, still there are problems with the accuracy of determining the cuttings layer height, critical velocity and other key parameters, which complicates the task of effective solution of the problem of borehole cleaning. The purpose of the study is to analyze the models obtained via the organization of a full factorial experiment and variance analysis to identify the influence of such factors as viscosity and flow rate of the drilling fluid in the annular space and the inclination angle of the well on the degree of cuttings transport. The studies of the kind are carried out using special devices called flow loops. Experimental data were taken from literature sources. To organize a full factorial experiment, the data of the dependent variable were combined into a combinational square, which simplified the coding of factor values. After setting the full factorial experiment, the models were obtained that made it possible to assess the contribution of the studied factors to the process of destruction product removal within the intervals determined while setting the research tasks. The obtained models allowed to determine the influence degree of each of the factors on the process under investigation. The results of the succeeding analysis of variance confirmed the indicated degree of influence and determined the rank of each of the factors in percentage.

Polyurethane Foam Rafts Supported In Vitro Cultures of Rindera graeca Roots for Enhanced Production of Rinderol, Potent Proapoptotic Naphthoquinone Compound

Unique phytochemical profile of plants belonging to Boraginaceae family provides a prolific resource of lipophilic pigments from the group of naphthoquinone derivatives. To overcome low compound content, the major obstacle of plant-based production, immobilization of Rindera graeca roots in in vitro cultures was implemented for efficient production of rinderol, novel furanonaphthoquinone derivative with anticancer properties. Chromatographic procedures revealed rinderol presence in extracts of all investigated root lines, derived both from root biomass and post-culture medium. Unexpectedly, in the second stage of the experiment, rinderol production was ceased in control, unmodified culture systems. On the contrary, roots immobilized on PUF rafts uniformly and stably produced rinderol, and its highest amount was noted for transformed root lines after 42 days of cultivation (222.98 ± 10.47 µg/flask). PUF occurred to be the main place of compound accumulation. Moreover, investigation of rinderol biological activity revealed its fast-acting cell death induction in HeLa cervical cancer cells at relatively low concentrations. Presented results revealed successful application of R. graeca roots immobilization on PUF rafts for production and in situ product removal of rinderol, novel lipophilic furanonaphthoquinone with suggested proapoptotic activity.

Removal of Inflammatory Tissue/Product by Sinus Membrane Puncturing during Lateral Sinus Augmentation in Asymptomatic Patients with Severely Opacified Sinuses: A Case Series

It is generally recommended that severe sinus membrane (SM) thickening should be treated prior to maxillary sinus augmentation (MSA), but during lateral MSA, inflammatory tissue/product may be removed by puncturing the SM. The present case report demonstrates surgical experience of lateral MSA with simultaneous inflammatory tissue/product removal for sinuses with severe opacification. In three patients requiring dental implant placement in the posterior maxilla, severe SM thickening was observed, but they were asymptomatic. The SM was gently elevated, followed by puncturing the SM, removing inflammatory tissue via the punctured site, draining, and thorough saline irrigation. Then, bone grafting and implant placement were performed with extra care not to spread bone substitute material into the punctured area. The postoperative pain following this procedure was more severe as compared to conventional MSA. Nasal bleeding was reported for 2–3 days. All implants were successfully integrated and demonstrated adequate function. Tissue samples retrieved during the surgery showed advanced inflammatory cell infiltration. The follow-up cone-beam computed tomographic scans revealed a significant reduction in SM thickening. In conclusion, inflammatory tissue/product removal by puncturing the SM can be applied during lateral MSA. However, more data should be needed due to the empirical nature of the present outcomes.

The effect of competition on product removal

The relationship between innovation and competition has been vastly studied over the past fifty years. However, one piece of the puzzle that has not been studied in detail is how in certain industries competition has an effect in the number of products that are removed from the market. That is why in this paper, I use scanner data to analyze the effect of competition on product removal. In particular, I track sales in the beer industry across a set of 1107 over a period of four years. Following previous studies, I use the merger between SABMiller and Molson Coors as an unexpected change in the industry to estimate future market concentration. I find that there is a negative relationship between removal and concentration. Therefore, retailers decide to remove products from their shelves in a faster way when the market is more competitive to open the gates for a more dynamic assortment.

Co-production of hydrogen and ethyl acetate in Escherichia coli

Background Ethyl acetate (C4H8O2) and hydrogen (H2) are industrially relevant compounds that preferably are produced via sustainable, non-petrochemical production processes. Both compounds are volatile and can be produced by Escherichia coli before. However, relatively low yields for hydrogen are obtained and a mix of by-products renders the sole production of hydrogen by micro-organisms unfeasible. High yields for ethyl acetate have been achieved, but accumulation of formate remained an undesired but inevitable obstacle. Coupling ethyl acetate production to the conversion of formate into H2 may offer an interesting solution to both drawbacks. Ethyl acetate production requires equimolar amounts of ethanol and acetyl-CoA, which enables a redox neutral fermentation, without the need for production of by-products, other than hydrogen and CO2. Results We engineered Escherichia coli towards improved conversion of formate into H2 and CO2 by inactivating the formate hydrogen lyase repressor (hycA), both uptake hydrogenases (hyaAB, hybBC) and/or overexpressing the hydrogen formate lyase activator (fhlA), in an acetate kinase (ackA) and lactate dehydrogenase (ldhA)-deficient background strain. Initially 10 strains, with increasing number of modifications were evaluated in anaerobic serum bottles with respect to growth. Four reference strains ΔldhAΔackA, ΔldhAΔackA p3-fhlA, ΔldhAΔackAΔhycAΔhyaABΔhybBC and ΔldhAΔackAΔhycAΔhyaABΔhybBC p3-fhlA were further equipped with a plasmid carrying the heterologous ethanol acyltransferase (Eat1) from Wickerhamomyces anomalus and analyzed with respect to their ethyl acetate and hydrogen co-production capacity. Anaerobic co-production of hydrogen and ethyl acetate via Eat1 was achieved in 1.5-L pH-controlled bioreactors. The cultivation was performed at 30 °C in modified M9 medium with glucose as the sole carbon source. Anaerobic conditions and gas stripping were established by supplying N2 gas. Conclusions We showed that the engineered strains co-produced ethyl acetate and hydrogen to yields exceeding 70% of the pathway maximum for ethyl acetate and hydrogen, and propose in situ product removal via gas stripping as efficient technique to isolate the products of interest.