166 research outputs found

    A Characterization of Different Alkali Chemical Agents for Alkaline Flooding Enhanced Oil Recovery Operations: An Experimental Investigation

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    Alkaline injection is a chemical enhanced oil recovery method that is used to increase oil recovery by reacting with the crude oil and creating an in situ surfactant. Many chemical agents can be used as an alkali during injection all of which have several advantages and disadvantages. This research focuses on the innate properties of three alkali agents and their ability to alter pH and temperature downhole. Alkali solutions were prepared with five different concentrations including 0.2, 1, 2, 3, and 4 wt%. The impact of varying the alkali concentration, monovalent cations manifested in sodium chloride, and divalent cations manifested in calcium chloride was investigated for all three alkalis. The chemical agents investigated include sodium hydroxide, sodium silicate, and sodium carbonate. Results indicated that sodium hydroxide and sodium silicate managed to impact the pH the most compared to the sodium carbonate. Sodium hydroxide also managed to increase the temperature significantly which is advantageous since it can reduce oil viscosity downhole. Sodium silicate had an advantage of being in liquid state at ambient conditions which makes injecting it downhole much easier compared to the two other alkaline agents. The chemical that was much affected by divalent cations was sodium silicate, which generated a precipitate and thus is not compatible with divalent cations, which are a major composition of most formation water. This research focuses on the innate properties of the alkali agents and the downhole factors that may impact their applicability in different oil reservoirs

    Preparation and characterization of starch /cellulose composite

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    Novel preparative method for starch/cellulose composite in different ratios has been reported. The composite is obtained by mixing cellulose extracted from paper garbage and corn starch in PEG/NaOH solution. Starch/cellulose composite is characterized by different techniques, namely XRD, TGA and optical absorption measurements. From XRD data, it is observed that cellulose would lead to expand the d-spacing of (1ī0 plane and decrease the d-spacing of (110) plane of starch. The UV absorption peaks are shifted towards the longest wavelengths in the visible region for starch/cellulose composite. However, the refractive index value decreases from 1.44 to 1.08 and consequently the dielectric constant value decreases from 2.07 to 1.16 with increasing the starch ratio. Furthermore, the glass transition temperature increases from 107 °C for starch to 115 °C for starch/cellulose composite. However, the excess in starch ratio leads to increase in local crosslink density in the composite network

    Analytical Study on Building a Comprehensive Big Data Management Maturity Framework

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    Harnessing big data in organizations today realizes benefits for competitive advantage. Generated profound insights are reflected in informed decision making, creating better business plans, and improved service delivery. Yet, organizations are still not recognizing how mature their big data management capabilities are. However, there is no structured approach to assess and build necessary capabilities for valuable big data utilizing, which draws a clear improvement pathway. Existing solutions lack a consistent perception of big data management capabilities, a reliable assessment, and a rigid improvement scheme. This paper contributes in building an analytical study on existing key works in assessing and building big data management capabilities. Drawing upon the results and gaps revealed from this analytical study, the main requirements for building a comprehensive big data management maturity framework are defined. This framework will enable organizations to assess and improve their current capabilities towards effective big data management.https://dorl.net/dor/ 20.1001.1.20088302.2022.20.1.13.

    The Association of Upper Body Obesity with Insulin Resistance in the Newfoundland Population

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    Body-fat distribution is a primary risk factor for insulin resistance and cardiovascular disease. Visceral fat explains only a portion of this risk. The link between upper-body fat and insulin resistance is uncertain. Furthermore, upper-body fat is not clearly defined. Dual-energy X-ray absorptiometry (DXA) can accurately quantify body fat. In this study, we explored the relationship between non-visceral upper-body adiposity and insulin resistance and other markers of metabolic syndrome. Fat proportions in the upper body, leg, and visceral regions were quantified by using DXA in 2547 adult Newfoundlanders aged 19 and older. Adjusting for remaining fat regions, we performed partial correlation analysis for each body region and insulin resistance defined by the Homeostatic Model of Assessment (HOMA). Similarly, partial correlation analysis was also performed between each fat region and other markers of metabolic syndrome, including high-density lipoprotein cholesterol (HDL), triglycerides (TG), body mass index (BMI), and blood pressure. Major confounding factors, including age, caloric intake, and physical activity, were statistically controlled by using partial correlation analysis. Interactions between sex, menopausal status, and medication status were also tested. Arm adiposity was correlated with HOMA-IR (R = 0.132, p < 0.001) and HOMA-β (R = 0.134, p < 0.001). Visceral adiposity was correlated with HOMA-IR (R = 0.230, p < 0.001) and HOMA-β (R = 0.160, p < 0.001). No significant correlation between non-visceral trunk adiposity and insulin resistance was found. Non-visceral trunk adiposity was negatively correlated with HDL in men (R = −0.110, p < 0.001) and women (R = −0.117, p < 0.001). Non-visceral trunk adiposity was correlated with TG (total: R = 0.079, p < 0.001; men: R = 0.105, p = 0.012; women: R = 0.078, p = 0.001). In menopausal women, leg adiposity was negatively correlated with HOMA-IR (R = −0.196, p < 0.001) and HOMA-β (R = −0.101, p = 0.012). Upper-body adiposity in the arms is an independent contributor to insulin resistance. Upper-body adiposity in the non-visceral trunk region is an independent contributor to metabolic syndrome. Leg adiposity is protective against metabolic syndrome in women

    Elemental, Morphological, and Corrosion Characterization of Different Surface States of Co-Cr Alloy for Prosthodontic Applications

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    In this study, four different groups were prepared in a cast model of an arch that received four implants made with a Co-Cr dental alloy. The surface of each group was prepared by four different surface treatments, including sandblasting with Al2O3 grains (SB), conventional finishing with dental burs (CF), milling with a CAD/CAM device (MIL), and electrodischarge machining (EDM). The characterization of the roughness parameters, morphology, elemental composition, and electrochemical properties of a dental Co-Cr alloy in different surface states exposed to an oral environment were reported. The electrochemical properties were tested with open-circuit potential (OCP) and anodic scan in Ringer’s solutions. The results of roughness parameters, elemental composition, OCP, corrosion potential and pitting potential were statistically analyzed by one-way ANOVA and the Tukey-Kramer multiple- comparison test at 95% confidence level. The roughness parameters classified the surfaces from smoothest to roughest according to the following order; CF, MIL, EDM, and SB. The CF group has the best corrosion resistance followed by the EDM, MIL, and SB groups

    Multiproxy analyses of paleoenvironmental and paleoceanographic changes during the Danian-Selandian in East Central Sinai: An integrated stable isotope and planktic foraminiferal data

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    Forty-three planktic foraminifera samples from the Themed section (East Central Sinai; Egypt) spanning the Zone Parvularugoglobigerina eugubina (Pα) to the Subzone Acarinina subsphaerica (P4b) have been studied. Data from δ13C, δ18O, and planktic foraminifera-based species diversity, depth habitat, preference for warm and cool surface waters, and nutrients (oligotrophic, mesotrophic, and eutrophic conditions) are used to infer paleoenvironmental changes throughout the Danian‒Selandian duration. Based on quantitative multivariate analyses (hierarchical cluster and principal component), three distinct intervals were recognized, Interval 1 (Pα‒P1b), Interval 2 (P1c‒P3a), and Interval 3 (P3a‒P4b). Interval 2 is further subdivided into three subintervals, 2a (part P1c), 2b (part P1c), and 2c (P2‒P3a). Two δ13C events are identified, Dan-C2 and Latest Danian Event (LDE) and elaborated concerning paleoenvironmental changes. During the earliest Danian planktic foraminiferal Pα Zone, moderately shallow and eutrophic conditions prevailed with cool surface waters and a shallow thermocline. Comparable conditions were still prevailing during P1a‒P1b, but with slightly deeper and mesotrophic conditions and a somewhat deeper thermocline and reduced stratification. P1b‒P1c exhibits a major shift from Eoglobigerina to Subbotina‒ Parasubbotina with cooler surface waters and moderate mesotrophic conditions. For Subzone P1c (upper part), slightly mesotrophic conditions were inferred, whereas for P2‒P3a (lower part), surface water warming and thermocline shallowing events have inferred with increased oligotrophic conditions. The Latest Danian Event (mid-P3a) is marked by a dramatic negative δ13C excursion, warm waters, increased mesotrophic conditions, and enhanced stratification. The dominance of Morozovella, Acarinina, and Igorina specify warm and oligotrophic conditions for subzones P3b‒P4b

    Entwicklung nachhaltiger Pflanzenschutzstrategien zur Bek_mpfung von Schadschmetterlingen im olivenanbau

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    Current olive growing practices range from the traditional Mediterranean olive grove to intensively managed olive plantations. Insecticides against major olive pests, like the olive moth (Prays oleae, Lep.: Yponomeutidae) and the jasmine moth, (Palpita unionalis, Lep.: Pyralidae) are still applied frequently. The European Union-funded international research project TRIPHELIO is aimed at the development of economically feasible and sustainable insecticide-free control methods for key Lepidopterous pests of olive. Main research activities focus on (1) the use of pheromones for mating disruption and improved monitoring of target pests, (2) habitat management strategies to enhance the activity of natural enemies in the olive grove, and (3) the use of inundative releases of mass-reared egg parasitoids of the genus Trichogramma. Moreover, tools for successful integration of the methods developed into an integrated pest management (IPM) strategy for olive pests were explored by optimising techniques for surveillance as well as considering potential side-effects of common pesticides on beneficial organisms. An intense exchange of scientific information and technology between European and North African countries was undertaken to create solutions for a wide range of olive growing regions. Key results and recommendations for further essential steps towards practical implementation are presented in this publication.Zusammenfassung Traditionelle, extensiv bearbeitete Olivenhaine, aber auch moderne Intensiv-Plantagen mit k_nstlicher Bew_sserung und hohem Einsatz von D_ngern bzw. chemischen Pflanzenschutzmitteln kennzeichnen die derzeitigen verschiedenen Anbauformen der Olive im Mittelmeerraum. Schadlepidopteren wie die Olivenmotte (Prays oleae, Lep.: Yponomeutidae) und die Jasminmotte (Palpita unionalis, Lep.: Pyralidae) werden durch regelm_ssigen Insektizideinsatz bek_mpft. Das von der EU gef_rderte internationale Forschungsprojekt TRIPHELIO zielte auf die Entwicklung insektizidfreier Alternativmethoden durch (1) die Optimierung der pheromongest _tzten _berwachung und Verwirrtechnik, (2) der Anwendung von Habitatmanagement-Strategien zur F_rderung nat_rlicher Gegenspieler, und (3) dem Einsatz von Trichogramma-Schlupfwespen. Zus_tzlich wurden Module f_r eine optimale Anwendung biotechnischer und biologischer Methoden bez_glich der Ph_nologie der Schadinsekten und m_glicher Nebenwirkungen von Pestiziden erarbeitet. Die intensive Kooperation zwischen Wissenschaftlern und Praktikern aus mehreren L_ndern Europas und Nordafrikas erlaubte den Entwurf m_glicher L_sungsans_tze f_r verschiedene Anbaubedingungen und klimatische Regionen des Mittelmeerraumes. Die wichtigsten Ergebnisse und Ausblicke f_r eine zuk_nftige praktische Umsetzung werden in dieser Ver_ffentlichung beschrieben

    Prediction of Gut Wall Integrity Loss in Viral Gastroenteritis by Non-Invasive Marker

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    BACKGROUND: Intestinal fatty acid binding proteins (I-FABPs) are mainly expressed in the intestinal villi, which are the initial site of destruction in viral gastroenteritis.AIM: This study was designed to assess serum I-FABPs as a predictor of gut wall integrity loss in viral gastroenteritis.PATIENTS AND METHODS: This case-control cross-sectional study was conducted on 93 cases of acute viral gastroenteritis. Twenty-eight healthy children matching in age were recruited as control group. Serum I-FABPs were measured using ELISA technique. Viral detection and typing were done by PCR for adenovirus, and by Reverse transcriptase PCR for rotavirus, astrovirus and norovirus.RESULTS: Serum I-FABPs level was significantly higher in the cases compared to the controls and was also higher in the 46 rotavirus gastroenteritis cases compared to other viral gastroenteritis cases. Serum I- FABPs level was significantly higher in severely dehydrated cases as compared to mildly dehydrated ones (P=0.037).CONCLUSION: Serum I-FABPs could be used as an early and sensitive predictor marker of gut wall integrity loss in children with viral gastroenteritis and its level can indicate case severity

    An evolutionary approach to modelling the thermo-mechanical behaviour of unsaturated soils

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    A new data mining approach is presented for modelling of the stress-strain and volume change behaviour of unsaturated soils considering temperature effects. The proposed approach is based on the evolutionary polynomial regression (EPR), which unlike some other data mining techniques, generates a transparent and structured representation of the behaviour of systems directly from raw experimental (or field) data. The proposed methodology can operate on large quantities of data in order to capture nonlinear and complex relationships between contributing variables. The developed models allow the user to gain a clear insight into the behaviour of the system. Unsaturated triaxial test data from literature was used for development and verification of EPR models. The developed models were also used (in a coupled manner) to produce the entire stress path of triaxial tests. Comparison of the EPR model predictions with the experimental data revealed the robustness and capability of the proposed methodology in capturing and reproducing the constitutive thermo-mechanical behaviour of unsaturated soils. More importantly, the capability of the developed models in accurately generalising the predictions to unseen data cases was illustrated. The results of a sensitivity analysis showed that the models developed from data are able to capture and represent the physical aspects of the unsaturated soil behaviour accurately. The merits and advantages of the proposed methodology are also discussed
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