Search results for: advanced oxidation process

Authors: I. Sarenkova, I. Ciprovica, I. Cinkmanis

Abstract:

Lactobionic acid is a disaccharide formed from gluconic acid and galactose, and produced by oxidation of lactose. Productivity of lactobionic acid by microbial synthesis can be affected by various factors, and one of them is a presence of potassium, magnesium and manganese ions. In order to extend lactobionic acid production efficiency, it is necessary to increase the yield of lactobionic acid by optimising the fermentation conditions and available substrates for Pseudomonas taetrolens growth. The object of the research was to determinate the application of K₂HPO₄, MnSO₄, MgSO₄ × 7H₂O salts in different concentration for effective lactose oxidation to lactobionic acid by Pseudomonas taetrolens. Pseudomonas taetrolens NCIB 9396 (NCTC, England) and Pseudomonas taetrolens DSM 21104 (DSMZ, Germany) were used for the study. The acid whey was used as the study object. The content of lactose in whey samples was determined using MilcoScan^TM Mars (Foss, Denmark) and high performance liquid chromatography (Shimadzu LC 20 Prominence, Japan). The content of lactobionic acid in whey samples was determined using the high performance liquid chromatography. The impact of studied salts differs, Mn²⁺ and Mg²⁺ ions enhanced fermentation instead of K⁺ ions. Results approved that Mn²⁺ and Mg²⁺ ions are necessary for Pseudomonas taetrolens growth. The study results will help to improve the effectiveness of lactobionic acid production with Pseudomonas taetrolens NCIB 9396 and DSM 21104.

Keywords: lactobionic acid, lactose oxidation, Pseudomonas taetrolens, whey

Procedia PDF Downloads 146

Authors: M. E. Velásquez Torres, F. Tzompantzi, J. C. Castillo-Rodríguez, A. G. Romero Villegas, S. Mendéz-Salazar, C. E. Santolalla-Vargas, J. Cardoso-Martínez

Abstract:

Photocatalytic degradation, as an advanced oxidation technology, is a promising method in organic pollutant degradation. In this sense, chlorophenols should be removed from the water because they are highly toxic. The TiO₂ - X% ZnS photocatalysts, where X represents the molar percentage of ZnS (3%, 5%, 10%, and 15%), were synthesized using the one-step sol-gel method to use them as photocatalysts to degrade 4-chlorophenol. The photocatalysts were synthesized by a one-step sol-gel method. They were refluxed for 36 hours, dried at 80°C, and calcined at 400°C. They were labeled TiO₂ - X%ZnS, where X represents the molar percentage of ZnS (3%, 5%, 10%, and 15%). The band gap was calculated using a Cary 100 UV-Visible Spectrometer with an integrating sphere accessory. Ban gap value of each photocatalyst was: 2.7 eV of TiO₂, 2.8 eV of TiO₂ - 3%ZnS and TiO₂ - 5%ZnS, 2.9 eV of TiO₂ - 10%ZnS and 2.6 eV of TiO2 - 15%ZnS. In a batch type reactor, under the irradiation of a mercury lamp (λ = 254 nm, Pen-Ray), degradations of 55 ppm 4-chlorophenol were obtained at 360 minutes with the synthesized photocatalysts: 60% (3% ZnS), 66% (5% ZnS), 74% (10% ZnS) and 58% (15% ZnS). In this sense, the best material as a photocatalyst was TiO₂ -10%ZnS with a degradation percentage of 74%.

Keywords: 4-chlorophenol, photocatalysis, water pollutant, sol-gel

Procedia PDF Downloads 116

Authors: S. Belakry, D. Fasquelle, A. Rolle, E. Capoen, R. N. Vannier, J. C. Carru

Abstract:

Solid oxide fuel cells (SOFCs) are promising devices for energy conversion due to their high electrical efficiency and eco-friendly behavior. Their performance is not only influenced by the microstructural and electrical properties of the electrodes and electrolyte but also depends on the interactions at the interfaces. Nowadays, commercial SOFCs are electrically efficient at high operating temperatures, typically between 800 and 1000 °C, which restricts their real-life applications. The present work deals with the objectives to reduce the operating temperature and to develop cost-effective intermediate-temperature solid oxide fuel cells (IT-SOFCs). This work focuses on the development of metal-supported solid oxide fuel cells (MS-IT-SOFCs) that would provide cheaper SOFC cells with increased lifetime and reduced operating temperature. In the framework, the local company TIBTECH brings its skills for the manufacturing of porous metal supports. This part of the work focuses on the physical, chemical, and electrical characterizations of porous metallic supports (stainless steel 316 L and FeCrAl alloy) under different exposure conditions of temperature and atmosphere by studying oxidation, mechanical resistance, and electrical conductivity of the materials. Within the target operating temperature (i.e., 500 to 700 ° C), the stainless steel 316 L and FeCrAl alloy slightly oxidize in the air and H2, but don’t deform; whereas under Ar atmosphere, they oxidize more than with previously mentioned atmospheres. Above 700 °C under air and Ar, the two metallic supports undergo high oxidation. From 500 to 700 °C, the resistivity of FeCrAl increases by 55%. But nevertheless, the FeCrAl resistivity increases more slowly than the stainless steel 316L resistivity. This study allows us to verify the compatibility of electrodes and electrolyte materials with metallic support at the operating requirements of the IT-SOFC cell. The characterizations made in this context will also allow us to choose the most suitable fabrication process for all functional layers in order to limit the oxidation of the metallic supports.

Keywords: stainless steel 316L, FeCrAl alloy, solid oxide fuel cells, porous metallic support

Procedia PDF Downloads 82

Authors: Abigaba Sophia

Abstract:

Artificial intelligence (AI) has transformed the education sector by revolutionizing educational frameworks by providing new opportunities and innovative advanced platforms for language translation during the teaching and learning process. In today's education sector, the primary key to scholarly communication is language; therefore, translation between different languages becomes vital in the process of communication. KIU-T being an International University, admits students from different nations speaking different languages, and English is the official language; some students find it hard to grasp a word during teaching and learning. This paper explores the practical aspect of using artificial intelligence technologies in an advanced language translation manner during teaching and learning. The impact of this technology is reflected in the education strategies to equip students with the necessary knowledge and skills for professional activity in the best way they understand. The researcher evaluated the demand for this practice since students have to apply the knowledge they acquire in their native language to their countries in the best way they understand. The main objective is to improve student's language competence and lay a solid foundation for their future professional development. A descriptive-analytic approach was deemed best for the study to investigate the phenomena of language translation intelligence alongside Microsoft Office during the teaching and learning process. The study analysed the responses of 345 students from different academic programs. Based on the findings, the researcher recommends using the artificial intelligence language translation technique during teaching, and this requires the wisdom of human content designers and educational experts. Lecturers and students will be trained in the basic knowledge of this technique to improve the effectiveness of teaching and learning to meet the student’s needs.

Keywords: artificial intelligence, language translation technique, teaching and learning process, Microsoft Office

Procedia PDF Downloads 68

Authors: M. Hoseinnezhad, K. Gharanjig

Abstract:

Two organic dyes comprising carbazole as the electron donors and cyanoacetic acid moieties as the electron acceptors were synthesized. The organic dye was prepared by standard reaction from carbazole as the starting material. To this end, carbazole was reacted with bromobenzene and further oxidation and reacted with cyanoacetic acid. The obtained organic dye was purified and characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹HNMR), carbon nuclear magnetic resonance (¹³CNMR) and elemental analysis. The influence of heteroatom on carbazole donors and cyno substitution on the acid acceptor is evidenced by spectral and electrochemical photovoltaic experiments. Finally, light fastness properties for organic dye were investigated.

Keywords: dye-sensitized solar cells, indoline dye, nanostructure, oxidation potential, solar energy

Procedia PDF Downloads 185

Authors: Michal Urzynicok, Krzysztof Kwiecinski

Abstract:

The development of materials used in the power generation industry for the production of boilers and their parts is characterized by high steam parameters, which present new challenges. Implementation of new combinations of alloying elements that lead to the best possible mechanical properties, including creep resistance, greatly affects new steels' weldability. All new grades have to undergo many different examinations, in regards to bending and welding, in order to enable the development of fabrication technologies, ensuring failure-free production and assembly of boiler components. 12% Cr martensitic steels like THOR™ 115 or VM-12 SHC are characterized by high oxidation resistance in high-temperature environments. At the moment, VM-12 SHC can be found in many boilers where both headers and superheater coils were produced. As this material is very difficult to obtain, a search for a proper replacement has begun. A new creep strength-enhanced ferritic steel for service in supercritical and ultra-supercritical boiler applications was developed by Tenaris in Italy and it is designated as Thor™115 (Tenaris High Oxidation Resistance). As high demand in power plants occurred to replace some parts of existing installations fabricated from VM12-SHC with other alternatives, a new development of welding procedures has begun to prepare fabricators for the challenges of joining old components with new THOR™ 115 material. This paper covers the first research of welding of dissimilar joints made out of VM12-SHC and THOR™ 115.

Keywords: thor, vm12, dissimilar welding, weldability

Procedia PDF Downloads 142

Authors: Brahmia Nadjet

Abstract:

The growing needs of displacements led advanced countries in this field install new specific transport systems, able to palliate any deficiencies, especially when regular public transport does not adequately meet the requests of users. In this context, on-demand transport systems (ODT) are very efficient; they rely on techniques based on the location of trip generators which should be assured effectively with the use of operators responsible of the advance reservation, planning and organization, and studying the different ODT criteria (organizational, technical, geographical, etc.). As the advanced countries in the field of transport, some developing countries are involved in the adaptation of the new technologies to reduce the deficit in their communication system. This communication presents the study of an ODT implementation in the west of Algeria, by developing the Geomatics side of the study. This part requires the use of specific systems (such as GIS, RDBMS), so we developed the process through an application in an environment of mobility by using the computer tools dedicated to the management of the entities related to the transport field.

Keywords: ODT, geomatics, GIS, transport systems

Procedia PDF Downloads 489

Authors: Prashant Sharma, Jyotsna Dutta Majumdar

Abstract:

The present study concerns development of a composite thermal barrier coating consisting of a mixture of La2O3 and YSZ (with 8 wt.%, 32 wt.% and 50 wt.% 50% La2O3) by plasma spray deposition technique on a CoNiCrAlY based bond coat deposited on Inconel 718 substrate by high velocity oxy-fuel deposition (HVOF) technique. The addition of La2O3 in YSZ causes the formation of pyrochlore (La2Zr2O7) phase in the inter splats boundary along with the presence of LaYO3 phase. The coefficient of thermal expansion is significantly reduced from due to the evolution of different phases and structural defects in the sprayed coating. The activation energy for TGO growth under isothermal and cyclic oxidation was increased in the composite coating as compared to YSZ coating.

Keywords: plasma spraying, oxidation resistance, thermal barrier coating, microstructure, X-ray method

Procedia PDF Downloads 337

Authors: Lifar M. S., Tereshchenko A. A., Bulgakov A. N., Guda S. A., Guda A. A., Soldatov A. V.

Abstract:

Metal nanoparticles are widely used as heterogeneous catalysts to activate adsorbed molecules and reduce the energy barrier of the reaction. Reaction product yield depends on the interplay between elementary processes - adsorption, activation, reaction, and desorption. These processes, in turn, depend on the inlet feed concentrations, temperature, and pressure. At stationary conditions, the active surface sites may be poisoned by reaction byproducts or blocked by thermodynamically adsorbed gaseous reagents. Thus, the yield of reaction products can significantly drop. On the contrary, the dynamic control accounts for the changes in the surface properties and adjusts reaction parameters accordingly. Therefore dynamic control may be more efficient than stationary control. In this work, a reinforcement learning algorithm has been applied to control the simulation of CO oxidation on a catalyst. The policy gradient algorithm is learned to maximize the CO₂ production rate based on the CO and O₂ flows at a given time step. Nonstationary solutions were found for the regime with surface deactivation. The maximal product yield was achieved for periodic variations of the gas flows, ensuring a balance between available adsorption sites and the concentration of activated intermediates. This methodology opens a perspective for the optimization of catalytic reactions under nonstationary conditions.

Keywords: artificial intelligence, catalyst, co oxidation, reinforcement learning, dynamic control

Procedia PDF Downloads 109

Authors: Rehin Sulay, Anandhu Krishna, Jintumol Mathew, Vibin Ipe Thomas

Abstract:

N-Nitrosodimethyl amine, the simplest member of the N-Nitrosoamine family, is a carcinogenic and mutagenic agent that has gained considerable research interest owing to its toxic nature. Ozonation of industrially important hydrazines such as unsymmetrical dimethylhydrazine (UDMH) or monomethylhydrazine (MMH) has been associated with NDMA formation and accumulation in the environment. UDMH/MMH - ozonation also leads to several other transformation products such as acetaldehyde dimethyl hydrazone (ADMH), tetramethyl tetra azene (TMT), diazomethane, methyl diazene, etc, which can be either precursors or competitors for NDMA formation.In this work, we explored the formation mechanism of ADMH and TMT from UDMH-ozonation and their further oxidation to NDMA using the second-order Moller Plesset perturbation theory employing the 6-311G(d) basis set. We have also investigated how MMH selectively forms methyl diazene and diazomethane under normal conditions and NDMA in the presence of excess ozone. Our calculations indicate that the reactions proceed via an initial H abstraction from the hydrazine –NH2 group followed by the oxidation of the generated N-radical species. The formation of ADMH from the UDMH-ozone reaction involves an acetaldehyde intermediate, which then reacts with a second UDMH molecule to generate ADMH. The preferable attack of ozone molecule on N=C bond of ADMH generates DMAN intermediate, which subsequently undergoes oxidation to form NDMA. Unlike other transformation products, TMT formation occurs via the dimerization of DMAN. Though there exist a N=N bonds in the TMT, which are preferable attacking sites for ozone, experimental studies show the lower yields of NDMA formation, which corroborates with the high activation barrier required for the process(42kcal/mol).Overall, our calculated results agree well with the experimental observations and rate constants. Computational calculations bring insights into the electronic nature and kinetics of the elementary reactions of this pathway, enabled by computed energies of structures that are not possible to access experimentally.

Keywords: reaction mechanism, ozonation, substituted hydrazine, transition state

Procedia PDF Downloads 69

Authors: S. Divya, M. Jose

Abstract:

Over the past years, industrial dyes have emerged as a significant threat to aquatic life, extensively detected in drinking water and groundwater, thus contributing to water pollution due to their improper and excessive use. To address this issue, the utilization of core-shell structures has been prioritized as it demonstrates remarkable efficiency in utilizing light energy for catalytic reactions and exhibiting excellent photocatalytic activity despite the availability of various photocatalysts. This work focuses on the photocatalytic degradation of Nd₂O₃@SiO₂ CSNs under UV light irradiation against MB and RhB dyes. Different characterization techniques, including XRD, FTIR, and TEM analyses, were employed to reveal the material's structure, functional groups, and morphological features. VSM and XPS analyses confirmed the soft, paramagnetic nature and chemical states with respective atomic percentages, respectively. Optical band gaps, determined using the Tauc plot model, indicated 4.24 eV and 4.13 eV for Nd₂O₃ NPs and Nd₂O₃@SiO₂ CSNs, respectively. The reduced bandgap energy of Nd₂O₃@SiO₂ CSNs enhances light absorption in the UV range, potentially leading to improved photocatalytic efficiency. The Nd₂O₃@SiO₂ CSNs exhibited greater degradation efficiency, reaching 95% and 96% against MB and RhB dyes, while Nd₂O₃ NPs showed 90% and 92%, respectively. The enhanced efficiency of Nd₂O₃@SiO₂ CSNs can be attributed to the larger specific surface area provided by the SiO₂ shell, as confirmed by surface area analysis using the BET surface area analyzer through N₂ adsorption-desorption.

Keywords: core shell nanocomposites, rare earth oxides, photocatalysis, advanced oxidation process

Procedia PDF Downloads 47

Authors: Dorothea Voß, Tobias Esser, Michael Huber, Jakob Albert

Abstract:

The growing world population and the associated increase in demand for energy and consumer goods, as well as increasing waste production, requires the development of sustainable processes. In addition, the increasing environmental awareness of our society is a driving force for the requirement that processes must be as resource and energy efficient as possible. In this context, the use of polyoxometalate catalysts (POMs) has emerged as a promising approach for the development of green processes. POMs are bifunctional polynuclear metal-oxo-anion cluster characterized by a strong Brønsted acidity, a high proton mobility combined with fast multi-electron transfer and tunable redox potential. In addition, POMs are soluble in many commonly known solvents and exhibit resistance to hydrolytic and oxidative degradation. Due to their structure and excellent physicochemical properties, POMs are efficient acid and oxidation catalysts that have attracted much attention in recent years. Oxidation processes with molecular oxygen are worth mentioning here. However, the fact that the POM catalysts are homogeneous poses a challenge for downstream processing of product solutions and recycling of the catalysts. In this regard, nanofiltration membranes have gained increasing interest in recent years, particularly due to their relative sustainability advantage over other technologies and their unique properties such as increased selectivity towards multivalent ions. In order to establish an efficient downstream process for the highly selective separation of homogeneous POM catalysts from aqueous solutions using nanofiltration membranes, a laboratory-scale membrane system was designed and constructed. By varying various process parameters, a sensitivity analysis was performed on a model system to develop an optimized method for the recovery of POM catalysts. From this, process-relevant key figures such as the rejection of various system components were derived. These results form the basis for further experiments on other systems to test the transferability to serval separation tasks with different POMs and products, as well as for recycling experiments of the catalysts in processes on laboratory scale.

Keywords: downstream processing, nanofiltration, polyoxometalates, homogeneous catalysis, green chemistry

Procedia PDF Downloads 79

Authors: Nadjet Brahmia

Abstract:

The growing needs of displacements led advanced countries in this field install new specific transport systems, able to palliate any deficiencies, especially when regular public transport does not adequately meet the requests of users. In this context, on-demand transportation (ODT) are very efficient; they rely on techniques based on the location of trip generators which should be assured effectively with the use of operators responsible of the advance reservation, planning and organization, and studying the different ODT criteria (organizational, technical, geographical, etc.). As the advanced countries in the field of transport, some developing countries are involved in the adaptation of the new technologies to reduce the deficit in their communication system. This communication presents the study of an ODT implementation in the west of Algeria, by developing the Geomatics side of the study. This part requires the use of specific systems (such as GIS, RDBMS…), so we developed the process through an application in an environment of mobility by using the computer tools dedicated to the management of the entities related to the transport field.

Keywords: ODT, geomatics, GIS, transport systems

Procedia PDF Downloads 542

Authors: A. Hassiba Zemmouri, B. Nabil Mameri, C. Hakim Lounici

Abstract:

In this study, the effect of Fenton technology pretreatment on the anaerobic digestion of excess waste activated sludge (WAS) was investigated. The variation of physicochemical characteristics (TOC, DS, VSS, VS) and biogas volume (as form of value added products) were also evaluated. The preselected operator conditions of Fenton pretreatment were 0.01ml H2O2/g SS, 150 [H2O2]/[Fe2+], 25g/l TS, at 25 °C and 30, 60 and120 min as treatment duration. The main results show a Maximum solubilization and biodegradability (70%) obtained at 120 min of Fenton pretreatment duration. An increasing of TOC in soluble phase related obviously by releasing organic substances of sludge flocs was contested. Improving in biogas volume was also, increased. Fenton oxidation pretreatment may be a promising chemical pre-treatment for a benefic digestion, stabilization and volume reduction.

Keywords: waste activated sludge, fenton pre-treatment, biodegradability, biogas

Procedia PDF Downloads 632

Authors: Fabrizio Codella, Chris Parker, Samer Saab

Abstract:

The Kigali Amendment is driving the adoption of low Global Warming Potential refrigerants in commercial refrigeration systems in over a hundred countries. Several refrigeration systems for the small and large retail stores at mild and hot ambient temperature climates have been compared for hydrofluorocarbons (HFC), hydrofluoroolefins (HFO), transcritical CO₂ and propane, in typical and advanced system architectures. The results of system performance, emissions and lifetime cost have been compared. The greatest benefits were found to be obtained by low global warming potential HFO advanced systems.

Keywords: commercial refrigeration, CO₂, emissions, HFO, lifetime cost, performance

Procedia PDF Downloads 137

Authors: Elzbieta Sikorska-Simmons

Abstract:

Advanced dementia is a progressive terminal brain disease that is accompanied by a syndrome of difficult to manage symptoms and complications that eventually lead to death. The management of advanced dementia poses major challenges to family caregivers who act as patient health care proxies in making medical treatment decisions. Little is known, however, about how they manage advanced dementia and how their treatment choices influence the quality of patient life. This prospective qualitative study examines the key medical treatment decisions that family caregivers make while managing advanced dementia. The term ‘family caregiver’ refers to a relative or a friend who is primarily responsible for managing patient’s medical care needs and legally authorized to give informed consent for medical treatments. Medical decision-making implies a process of choosing between treatment options in response to patient’s medical care needs (e.g., worsening comorbid conditions, pain, infections, acute medical events). Family caregivers engage in this process when they actively seek treatments or follow recommendations by healthcare professionals. Better understanding of medical decision-making from the family caregiver perspective is needed to design interventions that maximize the quality of patient life and limit inappropriate treatments. Data were collected in three waves of semi-structured interviews with 20 family caregivers for patients with advanced dementia. A purposive sample of 20 family caregivers was recruited from a senior care center in Central Florida. The qualitative personal interviews were conducted by the author in 4-5 months intervals. The ethical approval for the study was obtained prior to the data collection. Advanced dementia was operationalized as stage five or higher on the Global Deterioration Scale (GDS) (i.e., starting with the GDS score of five, patients are no longer able survive without assistance due to major cognitive and functional impairments). Information about patients’ GDS scores was obtained from the Center’s Medical Director, who had an in-depth knowledge of each patient’s health and medical treatment history. All interviews were audiotaped and transcribed verbatim. The qualitative data analysis was conducted to answer the following research questions: 1) what treatment decisions do family caregivers make while managing the symptoms of advanced dementia and 2) how do these treatment decisions influence the quality of patient life? To validate the results, the author asked each participating family caregiver if the summarized findings accurately captured his/her experiences. The identified medical decisions ranged from seeking specialist medical care to end-of-life care. The most common decisions were related to arranging medical appointments, medication management, seeking treatments for pain and other symptoms, nursing home placement, and accessing community-based healthcare services. The most challenging and consequential decisions were related to the management of acute complications, hospitalizations, and discontinuation of treatments. Decisions that had the greatest impact on the quality of patient life and survival were triggered by traumatic falls, worsening psychiatric symptoms, and aspiration pneumonia. The study findings have important implications for geriatric nurses in the context of patient/caregiver-centered dementia care. Innovative nursing approaches are needed to support family caregivers to effectively manage medical care needs of patients with advanced dementia.

Keywords: advanced dementia, family caregiver, medical decision-making, symptom management

Procedia PDF Downloads 113

Authors: Mannar R. Maurya, Bithika Sarkar, Fernando Avecilla

Abstract:

Peroxidase activity is possibly successfully used for different industrial processes in medicine, chemical industry, food processing and agriculture. However, they bear some intrinsic drawback associated with denaturation by proteases, their special storage requisite and cost factor also. Now a day’s artificial enzyme mimics are becoming a research interest because of their significant applications over conventional organic enzymes for ease of their preparation, low price and good stability in activity and overcome the drawbacks of natural enzymes e.g serine proteases. At present, a large number of artificial enzymes have been synthesized by assimilating a catalytic center into a variety of schiff base complexes, ligand-anchoring, supramolecular complexes, hematin, porphyrin, nanoparticles to mimic natural enzymes. Although in recent years a several number of vanadium complexes have been reported by a continuing increase in interest in bioinorganic chemistry. To our best of knowledge, the investigation of artificial enzyme mimics of vanadium complexes is very less explored. Recently, our group has reported synthetic vanadium schiff base complexes capable of mimicking peroxidases. Herein, we have synthesized monoidovanadium(IV) and dioxidovanadium(V) complexes of pyrazoleone derivateis ( extensively studied on account of their broad range of pharmacological appication). All these complexes are characterized by various spectroscopic techniques like FT-IR, UV-Visible, NMR (1H, 13C and 51V), Elemental analysis, thermal studies and single crystal analysis. The peroxidase mimic activity has been studied towards oxidation of pyrogallol to purpurogallin with hydrogen peroxide at pH 7 followed by measuring kinetic parameters. The Michaelis-Menten behavior shows an excellent catalytic activity over its natural counterparts, e.g. V-HPO and HRP. The obtained kinetic parameters (Vmax, Kcat) were also compared with peroxidase and haloperoxidase enzymes making it a promising mimic of peroxidase catalyst. Also, the catalytic activity has been studied towards the oxidation of 1-phenylethanol in presence of H2O2 as an oxidant. Various parameters such as amount of catalyst and oxidant, reaction time, reaction temperature and solvent have been taken into consideration to get maximum oxidative products of 1-phenylethanol.

Keywords: oxovanadium(IV)/dioxidovanadium(V) complexes, NMR spectroscopy, Crystal structure, peroxidase mimic activity towards oxidation of pyrogallol, Oxidation of 1-phenylethanol

Procedia PDF Downloads 326

Authors: Diego Carrasco, Catarina Freitas, Hugo Rio Tinto, Ricardo Rio Tinto, Nuno Couto, Joaquim Gago, Carlos Carvalho

Abstract:

Introduction: Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CD) to drain the gallbladder can be a palliative care procedure for non-surgical oncologic patients with cholelithiasis and cholangitis process. Case description: A 59-years old Caucasian male diagnosed with extrahepatic cholangiocarcinoma with multiple liver, lung and peritoneum metastasis, unresponsive to treatment with gemcitabine/cisplatin, presented in the institution with fever, hypotension, and severe upper right abdominal pain secondary to cholelithiasis and cholangitis process. The patient was admitted and started on large spectrum antibiotics plus fluid-challenge. Afterward, a percutaneous transhepatic biliary drainage (PTBD) was performed to drain the gallbladder. This procedure temporarily stabilized the patient. However, the definitive solution required gallbladder removal. Since the patient exhibited an advanced oncologic disease and poor response to the chemotherapy, he was not a candidate for surgical intervention. Diagnostic Pathways: A self-expanding metal stent was placed from the duodenum into the bile duct by endoscopic ultrasound-guided. The stent allowed efficient drainage of the contrast from the gallbladder at the end of the endoscopic procedure. Conclusion and Discussion: The stent allowed efficient drainage of the contrast from the gallbladder at the end of the endoscopic procedure and successfully reversed the cholangitis process. EUS-CD is an effective and safe technique and can be used as a palliative care procedure for non-surgical oncologic patients.

Keywords: palliative care, cholangiocarcinoma, choledochoduodenostomy, endoscopic ultrasound-guided

Procedia PDF Downloads 169

Authors: Feng-Tsai Weng, Rick Wang, Yan-Cong Liao

Abstract:

Passivation is a kind of surface treatment for material to reinforce the corrosion resistance specially the stainless alloy. Passive film, is to getting more potential compared to their status before passivation. An oxidation film can be formed on the surface of stainless steel, which has a strong corrosion resistance ability after passivation treatment. In this research, a new passivation technology is proposed for a special stainless alloy which contains a 12-14% Chromium. This method includes the A-A-A (alkaline-acid-alkaline) process basically, which was developed by Carpenter that can neutralize trapped acid. Besides, a corrosion resistant coating layer was obtained by immersing the parts in a water bath of mineral oil at high temperature. Salt spray test ASTM B368 was conducted to investigated performance of corrosion resistant of the passivated stainless steel alloy parts. Results show much better corrosion resistant that followed a coating process after A-A-A Passivation process, than only using A-A-A process. The passivation time is with more than 380 hours of salt spray test ASTM B368, which is equal to 3000 hours of Salt spray test ASTM B117. Proposed passivation method of stainless steel can be completed in about 3 hours.

Keywords: passivation, alkaline-acid-alkaline, stainless steel, salt spray test

Procedia PDF Downloads 353

Authors: An-Ya Lo, Yi-Chen Chung, Yun-Chi Hsu, Chuan-Ming Tseng, Chiu-Yue Lin

Abstract:

In this study, the ternary alloy catalyst Pt20RuxSny (where 20, x, y represent mass fractions of Pt, Ru, and Sn, respectively) was optimized for the preliminary study of bio-ethanol fuel cells (BAFC). The morphology, microstructure, composition, phase-structures, and electrochemical properties of Pt20RuxSny catalyst were examined by SEM, TEM, EDS-mapping, XRD, and potentiostat. The effect of Sn content on electrochemical active surface (EAS) and oxidation activity were discussed. As a result, the additional Sn greatly improves the efficiency of Pt20RuxSny, either x=0 or 10. Through discussing the difference between ethanol and glycol oxidations, the mechanism of tolerance against poisoning has been proved. Overall speaking, the catalytic activity are in the order of Pt20RuxSny > Pt20Rux > Pt20Sny in both ethanol and glycol systems. Finally, Pt20Ru10Sn15 catalyst was successfully applied to demonstrate the feasibility of using bio-alcohol.

Keywords: Pt-Sn alloy catalyst, Pt-Ru-Sn alloy catalyst, fuel cell, ethanol, ethylene glycol

Procedia PDF Downloads 401

Authors: Xiping Guo, Fanglin Ge, Ping Guan

Abstract:

Refractory high entropy alloys are alternative materials expected to be employed at high temperatures. The comprehensive changes of microstructure and properties of NbTiZrCrAl refractory high entropy alloys are systematically studied by adjusting Al content. Five kinds of button alloy ingots with different contents of Al in NbTiZrCrAlX (X=0, 0.2, 0.5, 0.75, 1.0) were prepared by vacuum non-consumable arc melting technology. The microstructure analysis results show that the five alloys are composed of BCC solid solution phase rich in Nb and Ti and Laves phase rich in Cr, Zr, and Al. The addition of Al changes the structure from hypoeutectic to hypereutectic, increases the proportion of Laves phase, and changes the structure from cubic C15 to hexagonal C14. The hardness and fracture toughness of the five alloys were tested at room temperature, and the compressive mechanical properties were tested at 1000℃. The results showed that the addition of Al increased the proportion of Laves phase and decreased the proportion of the BCC phase, thus increasing the hardness and decreasing the fracture toughness at room temperature. However, at 1000℃, the strength of 0.5Al and 0.75Al alloys whose composition is close to the eutectic point is the best, which indicates that the eutectic structure is of great significance for the improvement of high temperature strength of NbTiZrCrAl refractory high entropy alloys. The five alloys were oxidized for 1 h and 20 h in static air at 1000℃. The results show that only the oxide film of 0Al alloy falls off after oxidizing for 1 h at 1000℃. After 20h, the oxide film of all the alloys fell off, but the oxide film of alloys containing Al was more dense and complete. By producing protective oxide Al₂O₃, inhibiting the preferential oxidation of Zr, promoting the preferential oxidation of Ti, and combination of Cr₂O₃ and Nb₂O₅ to form CrNbO₄, Al significantly improves the high temperature oxidation resistance of NbTiZrCrAl refractory high entropy alloys.

Keywords: NbTiZrCrAl, refractory high entropy alloy, al content, microstructural evolution, room temperature mechanical properties, high temperature compressive strength, oxidation resistance

Procedia PDF Downloads 74

Authors: Prateep Wajeetongratana

Abstract:

The objectives of the research were to examine that how management accounting techniques were perceived and used by companies listed on the stock exchange and to investigate similarities or differences of management accounting practices between companies listed on the stock exchange and Thai SMEs. Descriptive and inferential statistics were employed. The finding found that almost all of the companies used traditional management accounting techniques more than advanced management accounting techniques. Four management accounting techniques having no significant association with business characteristic were standard costing, job order costing, process costing. The barriers that Thai SMEs encountered were a lack of proper accounting system and the insufficient knowledge in management accounting of the accountants. The comparison results revealed that both companies listed on the stock exchange and Thai SMEs used traditional management accounting techniques more than advanced techniques.

Keywords: companies listed on the stock exchange, financial budget, management accounting, operating budget

Procedia PDF Downloads 372

Authors: S. Trafela, X. Xua, K. Zuzek Rozmana

Abstract:

In this study, we used an accurate and precise method to measure the electrochemically active surface areas (Aecsa) of nickel electrodes. Calculated Aecsa is really important for the evaluation of an electro-catalyst’s activity in electrochemical reaction of different organic compounds. The method involves the electrochemical formation of Ni(OH)₂ and NiOOH in the presence of adsorbed oxalate in alkaline media. The studies were carried out using cyclic voltammetry with polycrystalline nickel as a reference material and electrodeposited nickel nanowires, homogeneous and heterogeneous nickel films. From cyclic voltammograms, the charge (Q) values for the formation of Ni(OH)₂ and NiOOH surface oxides were calculated under various conditions. At sufficiently fast potential scan rates (200 mV s⁻¹), the adsorbed oxalate limits the growth of the surface hydroxides to a monolayer. Although the Ni(OH)₂/NiOOH oxidation peak overlaps with the oxygen evolution reaction, in the reverse scan, the NiOOH/ Ni(OH)₂ reduction peak is well-separated from other electrochemical processes and can be easily integrated. The values of these integrals were used to correlate experimentally measured charge density with an electrochemically active surface layer. The Aecsa of the nickel nanowires, homogeneous and heterogeneous nickel films were calculated to be Aecsa-NiNWs = 4.2066 ± 0.0472 cm², Aecsa-homNi = 1.7175 ± 0.0503 cm² and Aecsa-hetNi = 2.1862 ± 0.0154 cm². These valuable results were expanded and used in electrochemical studies of formaldehyde oxidation. As mentioned nickel nanowires, heterogeneous and homogeneous nickel films were used as simple and efficient sensor for formaldehyde detection. For this purpose, electrodeposited nickel electrodes were modified in 0.1 mol L⁻¹ solution of KOH in order to expect electrochemical activity towards formaldehyde. The investigation of the electrochemical behavior of formaldehyde oxidation in 0.1 mol L⁻¹ NaOH solution at the surface of modified nickel nanowires, homogeneous and heterogeneous nickel films were carried out by means of electrochemical techniques such as cyclic voltammetric and chronoamperometric methods. From investigations of effect of different formaldehyde concentrations (from 0.001 to 0.1 mol L⁻¹) on electrochemical signal - current we provided catalysis mechanism of formaldehyde oxidation, detection limit and sensitivity of nickel electrodes. The results indicated that nickel electrodes participate directly in the electrocatalytic oxidation of formaldehyde. In the overall reaction, formaldehyde in alkaline aqueous solution exists predominantly in form of CH₂(OH)O⁻, which is oxidized to CH₂(O)O⁻. Taking into account the determined (Aecsa) values we have been able to calculate the sensitivities: 7 mA mol L⁻¹ cm⁻² for nickel nanowires, 3.5 mA mol L⁻¹ cm⁻² for heterogeneous nickel film and 2 mA mol L⁻¹ cm⁻² for heterogeneous nickel film. The detection limit was 0.2 mM for nickel nanowires, 0.5 mM for porous Ni film and 0.8 mM for homogeneous Ni film. All of these results make nickel electrodes capable for further applications.

Keywords: electrochemically active surface areas, nickel electrodes, formaldehyde, electrocatalytic oxidation

Procedia PDF Downloads 148

Authors: S. Ghosh, L. Ramos, A. N. Kouamé, A.-L. Teillout, H. Remita

Abstract:

Catalytic materials have attracted continuous attention due to their promising applications in a variety of energy and environmental applications including clean energy, energy conversion and storage, purification and separation, degradation of pollutants and electrochemical reactions etc. With the advanced synthetic technologies, polymer nanostructures and nanocomposites can be directly synthesized through soft template mediated approach using swollen hexagonal mesophases and modulate the size, morphology, and structure of polymer nanostructures. As an alternative to conventional catalytic materials, one-dimensional PDPB polymer nanostructures shows high photocatalytic activity under visible light for the degradation of pollutants. These photocatalysts are very stable with cycling. Transmission electron microscopy (TEM), and AFM-IR characterizations reveal that the morphology and structure of the polymer nanostructures do not change after photocatalysis. These stable and cheap polymer nanofibers and metal polymer nanocomposites are easy to process and can be reused without appreciable loss of activity. The polymer nanocomposites formed via one pot chemical redox reaction with 3.4 nm Pd nanoparticles on poly(diphenylbutadiyne) (PDPB) nanofibers (30 nm). The reduction of Pd (II) ions is accompanied by oxidative polymerization leading to composites materials. Hybrid Pd/PDPB nanocomposites used as electrode materials for the electrocatalytic oxidation of ethanol without using support of proton exchange Nafion membrane. Hence, these conducting polymer nanofibers and nanocomposites offer the perspective of developing a new generation of efficient photocatalysts for environmental protection and in electrocatalysis for fuel cell applications.

Keywords: conducting polymer, swollen hexagonal mesophases, solar photocatalysis, electrocatalysis, water depollution

Procedia PDF Downloads 371

Authors: Mohammad Arabi

Abstract:

The development of advanced technologies in the field of signal processing and vibration analysis has enabled more accurate analysis and fault detection in electrical systems. This research investigates the application of temporal and frequency features in detecting faults in electric motor bearings, aiming to enhance fault detection accuracy and prevent unexpected failures. The use of methods such as deep learning algorithms and neural networks in this process can yield better results. The main objective of this research is to evaluate the efficiency and accuracy of methods based on temporal and frequency features in identifying faults in electric motor bearings to prevent sudden breakdowns and operational issues. Additionally, the feasibility of using techniques such as machine learning and optimization algorithms to improve the fault detection process is also considered. This research employed an experimental method and random sampling. Vibration signals were collected from electric motors under normal and faulty conditions. After standardizing the data, temporal and frequency features were extracted. These features were then analyzed using statistical methods such as analysis of variance (ANOVA) and t-tests, as well as machine learning algorithms like artificial neural networks and support vector machines (SVM). The results showed that using temporal and frequency features significantly improves the accuracy of fault detection in electric motor bearings. ANOVA indicated significant differences between normal and faulty signals. Additionally, t-tests confirmed statistically significant differences between the features extracted from normal and faulty signals. Machine learning algorithms such as neural networks and SVM also significantly increased detection accuracy, demonstrating high effectiveness in timely and accurate fault detection. This study demonstrates that using temporal and frequency features combined with machine learning algorithms can serve as an effective tool for detecting faults in electric motor bearings. This approach not only enhances fault detection accuracy but also simplifies and streamlines the detection process. However, challenges such as data standardization and the cost of implementing advanced monitoring systems must also be considered. Utilizing temporal and frequency features in fault detection of electric motor bearings, along with advanced machine learning methods, offers an effective solution for preventing failures and ensuring the operational health of electric motors. Given the promising results of this research, it is recommended that this technology be more widely adopted in industrial maintenance processes.

Keywords: electric motor, fault detection, frequency features, temporal features

Procedia PDF Downloads 24

Authors: Nadia A. Wassif, Bassem S. Nabawy

Abstract:

This paper gives an account of the petrophysical characteristics and the petrographical descriptions of Tertiary vesicular and amygdaloidal olivine basalt samples from Wadi Wizr in the central Eastern Desert of Egypt. The petrographical studies indicated that the studied vesicular basalt is rich in calcic-plagioclase, augite and olivine in addition to numerous amounts of fine opaque minerals and vesicules filled with carbonate and quartz amygdales. The degree of oxidation and alteration of magnetite and ilmenite were discussed in details. Petrophysically, the studied samples can be grouped into two main groups; the first group of samples is amygdaloidal basalt as the second group is vesicular. The vesicular group (the permeable one) is characterized by fair to very good porosity ‘Φ’, good to very good permeability ‘k’, very low true formation factor ‘F’ and micro to ultra micropores. On the other hand, the amygdaloidal basalt group (impermeable group) is characterized by very low storage capacity properties, fair porosity, negligible permeability, medium to high true formation factor and ultra micorpores. It has been found that; the petrophysical behavior is strongly dependent on the degree of oxidation and alteration; and in particular on the rate of cooling and oxidation of the ore minerals which caused filling in the primarily produced vesicules by low temperature secondary minerals.

Keywords: vesicular, amygdaloidal, basalt, petrophysics, Egypt

Procedia PDF Downloads 341

Authors: Lexuan Zhong, Chang-Seo Lee, Fariborz Haghighat, Stuart Batterman, John C. Little

Abstract:

Ultraviolet photocatalytic oxidation (UV-PCO) technology has been recommended as a green approach to health indoor environment when it is integrated into mechanical ventilation systems for inorganic and organic compounds removal as well as energy saving due to less outdoor air intakes. Although much research has been devoted to UV-PCO, limited information is available on the UV-PCO behavior tested by the mixtures in literature. This project investigated UV-PCO performance and by-product generation using a single and a mixture of acetone and MEK at 100 ppb each in a single-pass duct system in an effort to obtain knowledge associated with competitive photochemical reactions involved in. The experiments were performed at 20 % RH, 22 °C, and a gas flow rate of 128 m3/h (75 cfm). Results show that acetone and MEK mutually reduced each other’s PCO removal efficiency, particularly negative removal efficiency for acetone. These findings were different from previous observation of facilitatory effects on the adsorption of acetone and MEK on photocatalyst surfaces.

Keywords: by-products, inhibitory effect, mixture, photocatalytic oxidation

Procedia PDF Downloads 488

Authors: Bahram Khan, Anderson Rocha Ramos, Rui R. Paulo, Fernando J. Velez

Abstract:

With the growing demand for a new blend of applications, the users dependency on the internet is increasing day by day. Mobile internet users are giving more attention to their own experiences, especially in terms of communication reliability, high data rates and service stability on move. This increase in the demand is causing saturation of existing radio frequency bands. To address these challenges, researchers are investigating the best approaches, Carrier Aggregation (CA) is one of the newest innovations, which seems to fulfill the demands of the future spectrum, also CA is one the most important feature for Long Term Evolution - Advanced (LTE-Advanced). For this purpose to get the upcoming International Mobile Telecommunication Advanced (IMT-Advanced) mobile requirements (1 Gb/s peak data rate), the CA scheme is presented by 3GPP, which would sustain a high data rate using widespread frequency bandwidth up to 100 MHz. Technical issues such as aggregation structure, its implementations, deployment scenarios, control signal techniques, and challenges for CA technique in LTE-Advanced, with consideration of backward compatibility, are highlighted in this paper. Also, performance evaluation in macro-cellular scenarios through a simulation approach is presented, which shows the benefits of applying CA, low-complexity multi-band schedulers in service quality, system capacity enhancement and concluded that enhanced multi-band scheduler is less complex than the general multi-band scheduler, which performs better for a cell radius longer than 1800 m (and a PLR threshold of 2%).

Keywords: component carrier, carrier aggregation, LTE-advanced, scheduling

Procedia PDF Downloads 180

Authors: Zohreh Derikvand

Abstract:

One new 2D metal-organic coordination polymer of Ni(II) namely [Ni2(ndc)2(DMSO)4(H2O)]n, where ndc = naphthalene-1,4-dicarboxylic acid and DMSO= dimethyl sulfoxide has been synthesized and characterized by elemental analysis, spectral (IR, UV-Vis), thermal (TG/DTG) analysis and single crystal X-ray diffraction. Compound 1 possesses a 2D layer structure constructed from dinuclear nickel(II) building blocks in which two crystallographically independent Ni2+ ions are bridged by ndc2– ligands and water molecule. The ndc2– ligands adopt μ3 bridging modes, linking the metal centers into a two-dimensional coordination framework. The two independent NiII cations are surrounded by dimethyl sulfoxide and naphthalene-1,4-dicarboxylate molecules in distorted octahedron geometry. In the crystal structures of 1 there are non-classical hydrogen bonding arrangements and C-H–π stacking interactions. Electrochemical behavior of [Ni2(ndc)2(DMSO)4(H2O)]n, (Ni-NDA) on the surface of carbon nanotube (CNTs) glassy carbon electrode (GCE) was described. The surface structure and composition of the sensor were characterized by scanning electron microscopy (SEM). Oxidation of fructose on the surface of modified electrode was investigated with cyclic voltammetry and electrochemical impedance spectroscopy (EIS) and the results showed that the Ni-NDA/CNTs film displays excellent electrochemical catalytic activities towards fructose oxidation.

Keywords: naphthalene-1, 4-dicarboxylic acid, crystal structure, coordination polymer, electrocatalysis, impedance spectroscopy

Procedia PDF Downloads 319

Authors: Mina Kargozari, Isabel Revilla Martin, Ángel A. Carbonell-Barrachina

Abstract:

Different formulations of Turkish fermented sausages (sucuks) prepared with camel meat-hump (CH), camel meat-beef fat (CB), beef-hump (BH) and beef-beef fat (BB), were characterized. The sausages were analytically compared to determine differences in proximate composition and total cholesterol content (TCC), quality parameters such as fatty acids profile and fat quality characteristics, and lipid oxidation parameters including peroxide value, thiobarbituric acid-reactive substances (TBARS) and resulted carbonyl compounds. The PUFAs/SFAs ratio was higher in CB and BB samples than CH and BH (p<0.05). The higher calculated atherogenic and thrombogenic indexes (AI and TI) were obtained from the samples made with hump (p< 0.05) as a result of high amounts of their SFAs. The CH sausages contained high amount of total fat (p<0.05) among all samples. The CB sucuks exhibited the highest protein content and the lowest TCC and rancidity at the end of ripening (p<0.05). The TBARS results showed that beef fat samples were more susceptible to lipid oxidation. Moreover, no significant difference (p<0.05) was observed for the values of short aldehydes among the sucuk samples excepting nonanal. This study demonstrated that supplementing camel meat for the production of dry-fermented sausage resulted in high quality products with good functional and nutritional characteristics.

Keywords: fermented sausages, quality properties, SPME, total cholesterol content

Procedia PDF Downloads 313