Products In Presence Research Articles

Two-step steam pyrolysis of biomass for hydrogen production

In this study, different char based catalysts were evaluated in order to increase hydrogen production from the steam pyrolysis of olive pomace in two stage fixed bed reactor system. Biomass char, nickel loaded biomass char, coal char and nickel or iron loaded coal chars were used as catalyst. Acid washed biomass char was also tested to investigate the effect of inorganics in char on catalytic activity for hydrogen production. Catalysts were characterized by using Brunauer–Emmet–Teller (BET) method, X-ray diffraction (XRD) analyzer, X-ray fluorescence (XRF) and thermogravimetric analyzer (TGA). The results showed that the steam in absence of catalyst had no influence on hydrogen production. Increase in catalytic bed temperature (from 500 °C to 700 °C) enhanced hydrogen production in presence of Ni-impregnated and non-impregnated biomass char. Inherent inorganic content of char had great effect on hydrogen production. Ni based biomass char exhibited the highest catalytic activity in terms of hydrogen production. Besides, Ni and Fe based coal char had catalytic activity on H2 production. On the other hand, the results showed that biomass char was not thermally stable under steam pyrolysis conditions. Weight loss of catalyst during steam pyrolysis could be attributed to steam gasification of biomass char itself. In contrast, properties of coal char based catalysts after steam pyrolysis process remained nearly unchanged, leading to better thermal stability than biomass char.

Gains from trade due to within-firm productivity: does services exporting matter?

Abstract This paper focuses on gains from trade due to rising within-firm productivity in presence of services exporting. The complementarity between exporting and investing in productivity enhancements is investigated by using descriptive regressions using rich, firm-level data for the period 2003–2011 for Turkey. The authors use three productivity measures for robustness purposes. The results show that firms that export both goods and services throughout the sample have higher productivity compared to all other firms in the sample. Another important result of the paper is related to the firms that switch from being goods exporters to goods and services exporters, which exhibit higher productivity than firms that export only goods or firms that switch from services exporting to exporting both goods and services. Finally, within-firm gains from trade as measured by the productivity growth of firms is insensitive to the services exporting status. More importantly, the authors observe no effect of any of export status of firms considered in this paper on their productivity growth.

Optimization and characterization of bioplastic produced by bacillus cereus

Bioplastics can be defined as plastics made of biomass such as corn, sugarcane etc. These substances have been increasingly spotlighted as means to saving fossil fuels, reducing CO2 emission and plastic wastes. Biodegradability of Bioplastics has been widely publicized in society and the demand for packaging is rapidly increasing among retailers and the food industry at large scale. The plastic which is available in market is very dangerous as it is non-biodegradable. Therefore, it is the demand of the day that biodegradable plastics should be produced and used. The present review highlights all these points regarding the applications, production, types, challenges, sustainability, fermentation, process development and use of cheap substrates for bioplastics production. The bacterial isolate Bacillus cereus SE-1 was found to possess a higher level of PHB production in presence of various carbon sources used. However, a higher level of production was obtained with maltose (5.63 g/l) and a lower production was obtained when dextrose (0.4 g/l) was used as sole carbon source. FTIR analysis reveals that, the extracted PHB possesses the same pattern of functional groups as that of the standard PHB i.e. the characteristics presence of –OH and –C=O stretching. In order to increase the potential use of the extracted PHB, it was blended with thermoplastic starch under experimental conditions. After blending, the crystalline nature of the product was highly increased as the diffraction patterns were observed at 2e values of 26.80°, 31.74°, 45.59°, and 56.22°. Thus, the bacterial mediated PHB synthesis can be used as a better alternative to deal with the currently available practices of plastic use and its gradually increasing pollution level.

Mechanistic insights into solvent induced alkylation of p-cresol with tert-butyl alcohol using Brönsted acidic ionic liquids

In this work, a combination of density functional theory (DFT) and ab initio methods were used to develop a molecular level understanding of the alkylation of p-cresol with tert-butyl alcohol using Bronsted acidic ionic liquids (ILs) as catalysts. Commonly used triethylammonium based Bronsted acidic ILs were synthesized and their catalytic activity in the alkylation of p-cresol were investigated. Theoretical molecular simulation mimicking the experimental conditions was used to explain the conversion of p-cresol and selectivity to the alkylated products. The experimentally obtained product selectivity was correlated with the theoretically calculated atom reactivity based on superdelocalizabality parameter and the charge distribution. Effect of these parameters in the neutral as well as ionic pathway mechanism in presence of ionic liquid and water solvent mixture were investigated. The mechanism is confirmed from thermochemical energy values that the direct O-alkylation leading to the kinetically controlled ether product predominates at lower temperature (343K) and shorter reaction time. Whereas, the thermodynamically controlled ortho C-alkylated product, 2-TBC, predominates at higher temperature and longer reaction time. Solvent was also found to affect the product selectivity either at the C- or O- sites. With the formation of water as a side product in the course of the alkylation reaction, the dielectric constant of the reaction media increased. Hence, rearrangement of the tert-butyl carbocation in O-alkylated product in presence of the combined IL and water media leads to the formation of C-alkylated products.

Empathy and Materiality in Pixar’s "Inside Out"

Inside Out takes mostly place in the head of 11-year-old Riley who has just moved with her parents from Minnesota to San Francisco triggering a major interior drama. Five major core feelings that would structure everyone’s lives—Joy, Sadness, Anger, Disgust, and Fear—struggle to cope with the new events in Riley’s live. Apart from moving to a different city, missing her friends, and her pastimes (hockey), she has entered the preteen years, those that entail the loss of childhood. The film approaches this crucial moment in a child’s life, by building up a parallel world inhabited by feelings that have feelings themselves. In this article, I explore how this film about feelings encourages a “feeling with” the characters. The theoretical developments on empathy and narrative fiction stress the importance of perspective taking and have revolved mostly around the question of (multiple) focalization. In this article, I focus on what we may call the ‘material evocations’ of the animated film, which I relate to Hans Ulrich Gumbrecht’s notion of “production of presence” as that spatial relationship to the world and its objects, the tangibility or evocation of tangibility in aesthetic production. I look at how empathy is represented and elicited in the film by paying special attention to some ‘material’ features of the film: the ways objects are anthropomorphized, the rhythm of interventions and, very importantly, the texture and tangibility of animated objects and characters. An analysis informed by material poetics allows us to think empathy and emotions as embodied cognition and as an acknowledgment of interdependency.

Mass spectrometry based in vitro assay investigations on the transformation of pharmaceutical compounds by oxidative enzymes

The ubiquitous presence of trace organic chemicals in wastewater and surface water leads to a growing demand for novel removal technologies. The use of isolated enzymes has been shown to possess the capability for a targeted application but requires a clearer mechanistic understanding. In this study, the potential of peroxidase from horseradish (HRP) and laccase from Pleurotus ostreatus (LccPO) to transform selected trace organic chemicals was studied using mass spectrometry (MS)-based in vitro enzyme assays. Conversion by HRP appeared to be more efficient compared to LccPO. Diclofenac (DCF) and sotalol (STL) were completely transformed by HRP after 4 h and immediate conversion was observed for acetaminophen (APAP). During treatment with LccPO, 60% of DCF was still detectable after 24 h and no conversion was found for STL. APAP was completely transformed after 20 min. Sulfamethoxazole (SMX), carbamazepine (CBZ), ibuprofen (IBP) and naproxen (NAP) were insusceptible to enzymatic conversion. In pharmaceutical mixtures, HRP exhibited a preference for DCF and APAP and the generally less efficient conversion of STL was enhanced in presence of APAP. Transformation product pattern after treatment with HRP revealed polymerization products for DCF while STL showed cleavage reactions. DCF product formation shifted towards a proposed dimeric iminoquinone product in presence of APAP whereas a generally less pronounced product formation in mixtures was observed for STL. In conclusion, the enzymatic treatment approach worked selectively and efficiently for a few pharmaceuticals. However, for application the investigation and possibly immobilization of multiplex enzymes being able to transform diverse chemical structures is recommended.

Valorization of waste Date pits biomass for biodiesel production in presence of green carbon catalyst

In this study, an efficient utilization of waste Date pits biomass for synthesizing green carbon catalyst as well as production of biodiesel were investigated. The green carbon catalyst was modified by KOH and characterized by XRD, SEM, EDX, TEM and BET. Taguchi method in Response Surface Methodology (RSM) was applied to study the effect of several process parameters such as reaction temperature, time, catalysts type and methanol to oil ratio, on the yield of the produced biodiesel. The optimized yield obtained was 91.6% when the process temperature was 65°C, with catalyst type C3 (6wt% KOH on carbon) within 1h and with 9:1 methanol to oil ratio. The produced biodiesel was completely characterized in order to verify its quality, compared with the international standards. Fuel properties of the produced biodiesel were found to be a cetane number 60.31, density 881kg/m3, viscosity 4.24 mm2/s, cloud point 3.9°C, cold filter plugging point −0.62°C, pour point −1.4°C and flash point 141°C, which lies within the limits specified by the international standards of ASTM and EN. Waste Date pits biomass can be a promising platform for the production of green carbon catalysts as well as biodiesel production.

Precise manipulation of biophysical particle parameters enables control of proinflammatory cytokine production in presence of TLR 3 and 4 ligands.

The manuscript describes a systematic investigation into the effects of biophysical parameters of nanoparticles (NPs) on immune cells. Modulation of the biophysical character of the NP surface can be achieved by introduction of amino acids on monodisperse silica NPs, introducing a range of tunable biophysical parameters of interest, i.e. distinct sizes, different surface charges and varying degrees of surface hydrophobicity. We examine internalization of the NP in dendritic cells (DCs) and measure a myriad of cytokines, including IL-1β and IFNγ, which prognosticate the efficacy of the NPs as a potential vaccine (IL-1β metric) or active cellular immunotherapy carrier (IFNγ metric). Two different TLR ligands (a viral TLR3 ligand and a bacterial TLR4 ligand) were used along with the PAA NPs to compare their costimulatory immunogenicity. We strongly believe that this study will provide crucial information to many readers of Acta Biomaterialia and further drive the use of nanoparticle platforms in modulating immune responses.

Quantification of the production of hydrogen peroxide H2O2 during accelerated wine oxidation

Understanding how wines react towards oxidation is of primary importance. Here, a novel approach was developed based on the quantitative determination of the key intermediate H2O2 produced during accelerated oxidation by ambient oxygen. The assay makes use of the conversion of the non-fluorescent Amplex Red substrate into a fluorescent product in presence of H2O2. The total production of H2O2 during 30min was quantified with low within-day and between-day variabilities.Polymerized pigments, but not total polyphenols, played a major role in the determination of H2O2 levels, which were lower in white wines than red wines. H2O2 amounts also increased with temperature and the addition of metal ions, but did not depend on the concentration of many other wine constituents such as SO2. H2O2 levels did not correlate with anti-oxidant properties.We believe that this novel methodology might be generically used to decipher the oxidation mechanisms in wines and food products.

Abstract 619: Alpha Keto Acids Decompose Peroxides and Prevents Oxidation of Lipoproteins

Background: Alpha keto acids are unstable and decompose rapidly. In this study, we tested the ability of alpha keto acids to reduce peroxides and inhibit oxidation of lipoproteins. Methods: Keto salicylic acid (KSA) and Keto Octanoicacid (KoA) were synthesized and their ability to reduce hydrogen peroxides as well as lipid peroxides (LOOH) was measured using 13-hydroperoxyoctadecadienoic acid (13-HPODE). Lipoproteins (LDL and HDL) were isolated from human plasma and oxidation of liporproteins was performed using copper and MPO in the presence or absence of the keto compounds. RAW 264.7 cells and HUVECS were incubated with LPS and mm-LDL respectively either in the presence or absence of the keto compounds. RNA was isolated from treated cells and real time PCR was performed to analyze IL-1α, IL-6, MCP-1 and VCAM1 gene expressions. Reactive oxygen species were evaluated using DCF fluorescence in presence and absence of the keto compounds. Results: KSA reduced both H2O2 and 13-HPODE whereas KoA is able to reduce the former but not the latter. Both compounds inhibited the lipoprotein oxidation in a dose dependent manner and were able to reduce ROS production by H2O2. KSA is able to inhibit both LPS as well as mm-LDL induced inflammation. However, KoA showed a dual effect as it induced inflammatory markers in the presence of LPS, but inhibited the mm-LDL-induced inflammatory gene expressions. Conclusion: The results of our studies suggest that these keto compounds a) inhibit both enzymatic and non enzymatic oxidation of lipoproteins; b) reduce peroxides and ROS and c) have inhibitory and inducing effect on inflammatory cytokine/gene production in presence of mm-LDL and LPS respectively. Based on these results, we predict that these keto compounds could have therapeutic potential in reducing CVD/atherosclerosis-associated inflammation.

An efficient optimization process for hydrocarbon production in presence of geological uncertainty using a clustering method: A case study on Brugge field

We present the main steps of a production optimization process in presence of geological uncertainty. The geological model is the main source of uncertainty in hydrocarbon reservoir simulation which can reduce viability of the simulation results to be utilized in a production optimization process. Optimization of the expected net present value (NPV) based on evaluations of all probable geological realizations require prohibitive computation time. In this paper, we use a clustering method named Kernel K-means Method (KKM) to select a representative subset of geological models. The suggested method has been examined on the benchmark model of Brugge field. The clustering method selected 9 out of 40 realizations tuned in a previous history matching study. The statistics derived from NPV calculations in the selected realizations demonstrate a good match with those of all 40 realizations.A Reduced Order Modelling (ROM) coupled with a physically based optimization method named Guided Pattern Search (GPS) has been extended to take geological uncertainties into account. Four different optimization processes based on a full order or a reduced order simulation coupled with a GPS or a conventional pattern search (PS) algorithm have been carried out using the selected realizations. The best NPV results were obtained by execution of GPS on a full order simulation model. ROM led to reduction of the simulation time by a factor of eight which would make the optimization process tractable but caused some inaccuracy in the NPV evaluations. The combination of GPS and ROM resulted in an acceptable trade-off between NPV maximization and run time reduction.

Ultrasound assisted biodiesel production in presence of dolomite catalyst

Ultrasound (US) assisted transesterification of canola oil in presence of heterogeneous catalysts calcined dolomite and CaO was investigated in comparison to each other. An US generator (200W, 20kHz) equipped with an horn type probe (19mm) was used to study the effect of catalyst amount (3–7wt.% of oil), methanol/oil molar ratio (4/1–15/1), ultrasound power (30–50W), temperature (25–60°C) and time (60–120min) on US assisted biodiesel synthesis. Biodiesel yield reached over 97.4% for calcined dolomite at the end of 90min and 95.5% for CaO at the end of 75min. According to the results, US improved the transesterification reaction by reducing necessary time for high biodiesel yield, using calcined dolomite as well CaO as heterogeneous catalyst.

Funding, Repo and Credit Inclusion in Option Pricing via Dividends

This paper specializes a number of earlier contributions to the theory of valuation of financial products in presence of credit risk, repurchase agreements and funding costs. Earlier works, including our own, pointed to the need of tools such as Backward Stochastic Differential Equations (BSDEs) or semi-linear Partial Differential Equations (PDEs), which in practice translate to ad-hoc numerical methods that are time-consuming and which render the full valuation and risk analysis difficult. We specialize here the valuation framework to benchmark derivatives and we show that, under a number of simplifying assumptions, the valuation paradigm can be recast as a Black-Scholes model with dividends. In turn, this allows for a detailed valuation analysis, stress testing and risk analysis via sensitivities. We refer to the full paper for a more complete mathematical treatment.

Culture medium pH influence on Gluconacetobacter physiology: Cellulose production rate and yield enhancement in presence of multiple carbon sources

Gluconacetobacter genera are valued for bacterial cellulose (BC) and acetic acid production. BC is produced at optimal yields in classical microbiological media that are expensive for a large scale of production. In addition, BC usage for industrial purposes is limited due to low conversion rate into cellulose and to long incubation duration.In this paper, Gluconacetobacter isolated from apple vinegar was kinetically studied to evaluate cellulose production in presence of different carbon sources. Acetic and citric acid effect on Gluconacetobacter metabolism is clarified. It was shown that Gluconacetobacter uses glucose as a primary carbon source for cells growth and products formation. Acetic acid employment as a co-carbon source in Hestrin Schramm medium showed an increase of 17% in BC yield with a moderate decrease in the crystallite size of the resulting polymer.

O saber histórico e a experiência estética no teatro documentário contemporâneo

The essay focuses on the contemporary documentary performance regarding the transmission of historical knowledge on a double perspective: theatre and the production of meaning, history and the production of presence, according to the ideas of German philosopher Hans Ulrich Gumbrecht. In order to accomplish that, two plays are analysed: Um Museu Vivo de Memorias Pequenas e Esquecidas [A Living Museum of Small and Forgotten Memories] by Joana Craveiro, from Lisbon, Portugal, and Guerrilheiras ou Para a Terra nao Ha Desaparecidos [Guerrilla Women or There Are No Missing People for the Earth] by Gabriela Carneiro da Cunha, from Rio de Janeiro, Brazil. DOCUMENTARY THEATRE / HISTORIOGRAPHY / MEMORY / PRODUCTION OF MEANING / PRODUCTION OF PRESENCE

The self-assembly approach of tissue engineering for in vitro production of human tissue- and organ-specific constructs

The self-assembly approach of tissue engineering for in vitro production of human tissue- and organ-specific constructs

Slurry Phase Hydrocracking of Residue by Phosphomolybdic and Phosphotungstic Acids

Slurry phase hydrocracking of vacuum residue was studied on heteropoly acids and on super acid. In this regards, heteropoly acid of phosphomolybdic, phosphotungstic and superacid of molybdenum-antimony fluoride were used. Deep hydrocracking of residue was noticed even at moderate operating conditions for all acidic catalysts. Due to higher hydrogenating functionality of tungsten, the HDM activity of the phosphotungstic acid is higher than that of molybdenum containing acids. Even the residue hydrocracking activity of former catalyst is also high. It is also noticed from sulphur distribution of liquid product that thiophenic sulphur compounds are formed due to C-S bond cleavage at branching of condensed aromatic rings. Moreover, phosphotungstic acid gives high percentage of aromatic products whereas the considerable amount of saturate hydrocarbons is produced by phosphomolybdic acid. The coke produced by phosphotungstic acid catalyst is hard in nature indicating that extensive polymerization reaction occurs at reaction conditions. Higher H/C ratio indicates the deep hydrogenation of liquid products in presence of super acids. Instead of use superacid, tungsten based heteropoly acid can be effectively used for hydrocracking of residue.

Glycerol conversion into value-added products in presence of a green recyclable catalyst: Acid black carbon obtained from coffee ground wastes

Black carbon from coffee grounds (BCC) was treated with sulfuric acid (BCC-S) or fuming sulfuric acid (BCC-SF) and utilized as catalysts in glycerol etherification reactions. The BCC-SF showed a high amount of sulfur groups, about 8%. However, the treated BCC-S showed the lowest amount of sulfur groups, about 3%. Furthermore, these catalysts show high catalytic activity in the glycerol etherification with tert-butyl alcohol (TBA), the activity being higher for the BCC-SF. The yields for mono-tert-butyl glycerol (MTBG), di-tert-butyl glycerol (DTBG) and tri-tert-butyl-glycerol (TTBG) were very similar to those obtained using a commercial resin, Amberlyst-15. The yields for BCC-SF were about 40 and 20% for the MTBG and DTBG + TTBG, respectively. Furthermore, the acid black carbons showed high stability of the active groups and can be reused in consecutive reactions.

Production of rhamnolipids by Pseudomonas aeruginosa is inhibited by H2S but resumes in a co-culture with P. stutzeri: applications for microbial enhanced oil recovery

Sulfate-reducing bacteria and H2S exist widely in oil production systems, and in situ production of rhamnolipids is promising for microbial enhanced oil recovery (MEOR). However, information of the effect of S(2-) on rhamnolipids production is scarce. Two facultative anaerobic rhamnolipids-producing bacterial strains, Pseudomonas aeruginosa SG and WJ-1, were used. Above 10 mg S(2-)/l, both cell growth and rhamnolipids production were inhibited. A large inoculum (9%, v/v) failed to completely relieve the inhibitory effect of 10 mg S(2-)/l. Below 30 mg S(2-)/l, both strains resumed rhamnolipid production through co-culturing with the denitrifying and sulphide-removing strain Pseudomonas stutzeri DQ1. H2S has a direct but reversible inhibitory effect on rhamnolipids production. Control of H2S in oilfields is indispensable to MEOR, and the co-culture method is effective in restoring rhamnolipid production in presence of S(2-).

Measurement and Comparison of Reliability Performance of Photovoltaic Power Optimizers for Energy Production

Abstract Photovoltaic (PV) power optimizers are introduced in PV systems to improve their energetic productivity in presence of mismatching phenomena and not uniform operating conditions. Commercially available converters are characterized by different DC-DC topologies. A promising one is the boost topology with its different versions. It is characterized by its circuital simplicity, few devices and high efficiency values - necessary features for a Distributed Maximum Power Point Tracking (DMPPT) converter. PV power optimizer designs represent a challenging task since they operate in continuously changing operating conditions which strongly influence electronic component properties and thus the performance of complete converters. An aspect to carefully analyze in such applications is the thermal factor. In this paper, a necessity to have a suitable temperature monitoring system to avoid dangerous conditions is underlined In addition, another important requirement for a PV power optimizer is its reliability, since it can suggest a useful information on its diagnostic aspects, maintenance and investments. In fact, a reliable device requires less maintenance services, also improving the economic aspect. The evaluation of the electronic system reliability can be carried out using different reliability prediction models. In this paper, reliability indices, such as the Mean Time Between Failure (MTBF) or the Failure Rate of a Diode Rectification (DR) boost, are calculated using the evaluation of the Military Handbook 217F and Siemens SN29500 prediction models. With the reliability prediction results it has been possible to identify the most critical components of a DMPPT converter and a measurement setup has been developed in order to monitor the component stress level on the temperature, power, voltage, current, and energy in the DMPPT design phase avoiding the occurrence of a failure that might decrease the service life of the equipment.