Search results for: hybridization chain reaction
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4173

Search results for: hybridization chain reaction

2043 Detection of Heroin and Its Metabolites in Urine Samples: A Chemiluminescence Approach

Authors: Sonu Gandhi, Neena Capalash, Prince Sharma, C. Raman Suri

Abstract:

A sensitive chemiluminescence immunoassay (CIA) for heroin and its major metabolites is reported. The method is based on the competitive reaction of horseradish peroxidase (HRP)-labeled anti-MAM antibody and free drug in spiked urine samples. A hapten-protein conjugate was synthesized by using acidic derivative of monoacetyl morphine (MAM) coupled to carrier protein BSA and was used as an immunogen for the generation of anti-MAM (monoacetyl morphine) antibody. A high titer of antibody (1:64,0000) was obtained and the relative affinity constant (Kaff) of antibody was 3.1×107 l/mol. Under the optimal conditions, linear range and reactivity for heroin, mono acetyl morphine (MAM), morphine and codeine were 0.08, 0.09, 0.095 and 0.092 ng/mL respectively. The developed chemiluminescence inhibition assay could detect heroin and its metabolites in standard and urine samples up to 0.01 ng/ml.

Keywords: heroin, metabolites, chemiluminescence immunoassay, horse radish peroxidase

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2042 Epidemiological Model for Citrus Black Spot Dynamics along the Pre-Harvest Supply Chain

Authors: Nqobile Muleya, Winston Garira, Godwin Mchau

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Citrus Black Spot (CBS) is a fungal disease that is responsible for huge economical loss and poses a threat to the citrus industry worldwide. We construct a mathematical model framework for citrus black spot between fruits to characterise the dynamics of the disease development, paying attention to the pathogen life cycle. We have made an observation from the model analysis that the initial inoculum from ascomata is very important for disease development and thereafter it is no longer important due to conidia which is responsible for secondary infection. Most importantly, the model indicated that ascospores and conidia are very important parameters in developing citrus black spot within a short distance. The basic reproductive number and its importance in relation to citrus black spot persistence are outlined. A numerical simulation of the model was done to explain the theoretical findings.

Keywords: epidemiological modelling, Guidnardia citricarpa, life cycle stage, fungal, disease development

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2041 Structural and Optical Characterization of Silica@PbS Core–Shell Nanoparticles

Authors: A. Pourahmad, Sh. Gharipour

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The present work describes the preparation and characterization of nanosized SiO2@PbS core-shell particles by using a simple wet chemical route. This method utilizes silica spheres formation followed by successive ionic layer adsorption and reaction method assisted lead sulphide shell layer formation. The final product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopic, infrared spectroscopy (IR) and transmission electron microscopy (TEM) experiments. The morphological studies revealed the uniformity in size distribution with core size of 250 nm and shell thickness of 18 nm. The electron microscopic images also indicate the irregular morphology of lead sulphide shell layer. The structural studies indicate the face-centered cubic system of PbS shell with no other trace for impurities in the crystal structure.

Keywords: core-shell, nanostructure, semiconductor, optical property, XRD

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2040 Protein-Thiocyanate Composite as a Sensor for Iron III Cations

Authors: Hosam El-Sayed, Amira Abou El-Kheir, Salwa Mowafi, Marwa Abou Taleb

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Two proteinic biopolymers; namely keratin and sericin, were extracted from their respective natural resources by simple appropriate methods. The said proteins were dissolved in the appropriate solvents followed by regeneration in a form of film polyvinyl alcohol. Proteinium thiocyanate (PTC) composite was prepared by reaction of a regenerated film with potassium thiocyanate in acid medium. In another experiment, the said acidified proteins were reacted with potassium thiocyante before dissolution and regeneration in a form of PTC composite. The possibility of using PTC composite for determination of the concentration of iron III ions in domestic as well as industrial water was examined. The concentration of iron III cations in water was determined spectrophotometrically by measuring the intensity of blood red colour of iron III thiocyanate obtained by interaction of PTC with iron III cation in the tested water sample.

Keywords: iron III cations, protein, sensor, thiocyanate, water

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2039 Influence of La on Increasing the ORR Activity of LaNi Supported with N and S Co-doped Carbon Black Electrocatalyst for Fuel Cells and Batteries

Authors: Maryam Kiani

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Non-precious electrocatalysts play a crucial role in the oxygen reduction reaction (ORR) for regenerative fuel cells and rechargeable metal-air batteries. To enhance ORR activity, La (a less active element) is added to modify the activity of Ni. This addition increases the surface contents of Ni2+, N, and S species in LaNi/N-S-C, while still maintaining a substantial specific surface area and hierarchical porosity. Therefore, the additional La is essential for the successful ORR process.In addition, the presence of extra La in the LaNi/N-S-C electrocatalyst enhances the efficiency of charge transfer and improves the surface acid-base characteristics, facilitating the adsorption of oxygen molecules during the ORR process. As a result, this superior and desirable electrocatalyst exhibits significantly enhanced ORR bifunctional activity. In fact, its ORR activity is comparable to that of the 20 wt% Pt/C.

Keywords: fuel cells, batteries, dual-doped carbon black, ORR

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2038 Design of Dendritic Molecules Bearing Donor-Acceptor Groups (Pyrene-Bodipy): Optical and Photophysical Properties

Authors: Pasquale Porcu, Mireille Vonlanthen, Gerardo Zaragoza-Galán, Ernesto Rivera

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In this work, we report the synthesis of a novel series of dendritic molecules bearing donor-acceptor groups (pyrene-bodipy) with potential applications in energy transfer. Initially, first and second generation Fréchet type dendrons (Py2-G1OH and Py4-G2OH) were prepared from 1-pyrenylbutanol and 3,5-dihydroxybenzylic alcohol. These compounds were further linked to a bodipy unit via an esterification reaction in order to obtain the desired products (Bodipy-G1Py2) and Bodipy-G2Py4). These compounds were fully characterized by FTIR and 1H and 13C NMR spectroscopy and their molecular weights were determined by MALDITOF. The optical and photophysical properties of these molecules were evaluated by absorbance and fluorescence spectroscopy, in order to compare their behaviour with other analogue molecules.

Keywords: bodipy, dendritic molecules, optical properties, pyrene

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2037 Business Strategy, Crisis and Digitalization

Authors: Flora Xu, Marta Fernandez Olmos

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This article is mainly about critical assessment and comprehensive understanding of the business strategy in the post COVID-19 scenario. This study aims to elucidate how companies are responding to the unique challenges posed by the pandemic and how these measures are shaping the future of the business environment. The pandemic has exposed the fragility and flexibility of the global supply chain, and procurement and production strategies should be reconsidered. It should increase the diversity of suppliers and the flexibility of the supply chain, and some companies are considering transferring their survival to the local market. This can increase local employment and reduce international transportation disruptions and customs issues. By shortening the distance between production and market, companies can respond more quickly to changes in demand and unforeseen events. The demand for remote work and online solutions will increase the adoption of digital technology and accelerate the digital transformation of many organizations. Marketing and communication strategies need to adapt to a constantly changing environment. The business resilience strategy was emphasized as a key component of the response to the COVID-19. The company is seeking to strengthen its risk management capabilities and develop a business continuity plan to cope with future unexpected disruptions. The pandemic has reconfigured human resource practices and changed the way companies manage their employees. Remote work has become the norm, and companies focus on managing workers' health and well-being, as well as flexible work policies to ensure operations and support for employees during crises. This change in human resources practice has a lasting impact on how companies apply talent and labor management in the post COVID-19 world. The pandemic has prompted a significant review of business strategies as companies adapt to constantly changing environments and seek to ensure their sustainability and profitability in times of crisis. This strategic reassessment has led to product diversification, exploring international markets and adapting to the changing market. Companies have responded to the unprecedented challenges brought by the COVID-19. The COVID-19 has promoted innovation effort in key areas and focused on the responsibility in today's business strategy for sustainability and the importance of corporate society. The important challenge of formulating and implementing business strategies in uncertain times. These challenges include making quick and agile decisions in turbulent environments, risk management, and adaptability to constantly changing market conditions. The COVID-19 highlights the importance of strategic planning and informed decision-making - making in a business environment characterized by uncertainty and complexity. In short, the pandemic has reconfigured the way companies handle business strategies and emphasized the necessity of preparing for future challenges in a business world marked by uncertainty and complexity.

Keywords: business strategy, crisis, digitalization, uncertainty

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2036 Simulation Modeling and Analysis of In-Plant Logistics at a Cement Manufacturing Plant in India

Authors: Sachin Kamble, Shradha Gawankar

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This paper presents the findings of successful implementation of Business Process Reengineering (BPR) of cement dispatch activities in a cement manufacturing plant located in India. Simulation model was developed for the purpose of identifying and analyzing the areas for improvement. The company was facing a problem of low throughput rate and subsequent forced stoppages of the plant leading to a high production loss of 15000MT per month. It was found from the study that the present systems and procedures related to the in-plant logistics plant required significant changes. The major recommendations included process improvement at the entry gate, reducing the cycle time at the security gate and installation of an additional weigh bridge. This paper demonstrates how BPR can be implemented for improving the in-plant logistics process. Various recommendations helped the plant to increase its throughput by 14%.

Keywords: in-plant logistics, cement logistics, simulation modelling, business process re-engineering, supply chain management

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2035 Effects of Conjugated Linoleic Acid on the Reproductive Axis of Ram

Authors: Behnaz Mahdavi, Hamidreza Khodaei, Alireza Banitaba

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Conjugated Linoleic Acid is a group of long-chain unsaturated fatty acids with more than one double bond and a mixture of 28 isomers of Linoleic acid (C 18:2) and it is counted as one of the essential acids. The main purpose of this study was to investigate the effect of CLA on some reproductive hormones in rams. In this study, six rams 3 to 4 years old with an average weight of 90 kg were selected. Rams were randomly divided into 3 groups and were treated by CLA treatment for 30 days. The first group (as a control group) did not receive CLA, The second group received 0.5 gr and the third group received 1 gram of CLA. The blood testing was done on rams every 15 days using a 20 ml syringe. Data analysis was performed by SAS software. Also mean comparison was done using Duncan's test method (p<0.05). Obtained results showed that the serum concentration of testosterone hormone was decreased numerically as well as the concentration of FSH hormone however the concentration of LH was increased. Also, the CLA had a significant effect on Leptin concentration. CLA in oral form can reduce the concentration of testosterone in rams.

Keywords: CLA, ram, testosterone, conjugated linoleic acid

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2034 Waste Recovery: A Sustainable Way for Application of Solid Waste from WTP's in Building Materials

Authors: Flavio Araujo, Livia Dias, Fabiolla Lima, Paulo Scalize, Antonio Albuquerque

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Water treatment residues (WTR) are solid waste produced during drinking water treatment and have recently been seen as a reusable material. The aim of this research was show how to use the residue generated in a Water Treatment Plant, located in Goiania, Brazil, following the considerations of the law of solid waste to obtain normative parameters and consider sustainable alternatives for reincorporation of the residues in the productive chain for manufacturing various materials construction. In order to reduce the environmental liabilities generated by sanitation companies and discontinue unsustainable forms of disposal. The analyzes performed: Granulometry, Scanning Electron Microscopy and X-Ray Diffraction demonstrated the potential application of residues to replace the soil and sand, because it has characteristics compatible with small aggregate and can be used as feedstock for the manufacture of materials as ceramic and soil-cement bricks, mortars, interlocking floors and concrete artifacts.

Keywords: residue, sustainable, water treatment plants, WTR, WTP

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2033 Evaluation of Yield and Yield Components of Malaysian Palm Oil Board-Senegal Oil Palm Germplasm Using Multivariate Tools

Authors: Khin Aye Myint, Mohd Rafii Yusop, Mohd Yusoff Abd Samad, Shairul Izan Ramlee, Mohd Din Amiruddin, Zulkifli Yaakub

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The narrow base of genetic is the main obstacle of breeding and genetic improvement in oil palm industry. In order to broaden the genetic bases, the Malaysian Palm Oil Board has been extensively collected wild germplasm from its original area of 11 African countries which are Nigeria, Senegal, Gambia, Guinea, Sierra Leone, Ghana, Cameroon, Zaire, Angola, Madagascar, and Tanzania. The germplasm collections were established and maintained as a field gene bank in Malaysian Palm Oil Board (MPOB) Research Station in Kluang, Johor, Malaysia to conserve a wide range of oil palm genetic resources for genetic improvement of Malaysian oil palm industry. Therefore, assessing the performance and genetic diversity of the wild materials is very important for understanding the genetic structure of natural oil palm population and to explore genetic resources. Principal component analysis (PCA) and Cluster analysis are very efficient multivariate tools in the evaluation of genetic variation of germplasm and have been applied in many crops. In this study, eight populations of MPOB-Senegal oil palm germplasm were studied to explore the genetic variation pattern using PCA and cluster analysis. A total of 20 yield and yield component traits were used to analyze PCA and Ward’s clustering using SAS 9.4 version software. The first four principal components which have eigenvalue >1 accounted for 93% of total variation with the value of 44%, 19%, 18% and 12% respectively for each principal component. PC1 showed highest positive correlation with fresh fruit bunch (0.315), bunch number (0.321), oil yield (0.317), kernel yield (0.326), total economic product (0.324), and total oil (0.324) while PC 2 has the largest positive association with oil to wet mesocarp (0.397) and oil to fruit (0.458). The oil palm population were grouped into four distinct clusters based on 20 evaluated traits, this imply that high genetic variation existed in among the germplasm. Cluster 1 contains two populations which are SEN 12 and SEN 10, while cluster 2 has only one population of SEN 3. Cluster 3 consists of three populations which are SEN 4, SEN 6, and SEN 7 while SEN 2 and SEN 5 were grouped in cluster 4. Cluster 4 showed the highest mean value of fresh fruit bunch, bunch number, oil yield, kernel yield, total economic product, and total oil and Cluster 1 was characterized by high oil to wet mesocarp, and oil to fruit. The desired traits that have the largest positive correlation on extracted PCs could be utilized for the improvement of oil palm breeding program. The populations from different clusters with the highest cluster means could be used for hybridization. The information from this study can be utilized for effective conservation and selection of the MPOB-Senegal oil palm germplasm for the future breeding program.

Keywords: cluster analysis, genetic variability, germplasm, oil palm, principal component analysis

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2032 Improvement in Ni (II) Adsorption Capacity by Using Fe-Nano Zeolite

Authors: Pham-Thi Huong, Byeong-Kyu Lee, Jitae Kim, Chi-Hyeon Lee

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Fe-nano zeolite adsorbent was used for removal of Ni (II) ions from aqueous solution. The adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and the surface area Brunauer–Emmett–Teller (BET) using for analysis of functional groups, morphology and surface area. Bath adsorption experiments were analyzed on the effect of pH, time, adsorbent doses and initial Ni (II) concentration. The optimum pH for Ni (II) removal using Fe-nano zeolite was found at 5.0 and 90 min of reaction time. The maximum adsorption capacity of Ni (II) was 231.68 mg/g based on the Langmuir isotherm. The kinetics data for the adsorption process was fitted with the pseudo-second-order model. The desorption of Ni (II) from Ni-loaded Fe-nano zeolite was analyzed and even after 10 cycles 72 % desorption was achieved. These finding supported that Fe-nano zeolite with high adsorption capacity, high reuse ability would be utilized for Ni (II) removal from water.

Keywords: Fe-nano zeolite, adsorption, Ni (II) removal, regeneration

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2031 Perovskite-Type La1−xCaxAlO3 (x=0, 0.2, 0.4, 0.6) as Active Anode Materials for Methanol Oxidation in Alkaline Solutions

Authors: M. Diafi, M. Omari, B. Gasmi

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Perovskite-type La1−xCaxAlO3 were synthesized at 1000◦C by a co- precipitation method. The synthesized oxide powders were characterized by X-ray diffraction (XRD) and the oxide powders were produced in the form of films on pretreated Ni-supports by an oxide-slurry painting technique their electrocatalytic activities towards methanol oxidation in alkaline solutions at 25°C using cyclic voltammetry, chronoamperometry, and anodic Tafel polarization techniques. The oxide catalysts followed the rhombohedral hexagonal crystal geometry. The rate of electro-oxidation of methanol was found to increase with increasing substitution of La by Ca in the oxide matrix. The reaction indicated a Tafel slope of ~2.303RT/F, The electrochemical apparent activation energy (〖∆H〗_el^(°#)) was observed to decrease on increasing Ca content. The results point out the optimum electrode activity and stability of the Ca is x=0.6 of composition.

Keywords: electrocatalysis, oxygen evolution, perovskite-type La1−x Cax AlO3, methanol oxidation

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2030 Pet Bearing Bio-Based Moities

Authors: Majdi Abid

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During the last few decades, great efforts have been made for the development of innovative materials using vegetal biomass. This strategy is understandable for different reasons including the predictable dwindling of the petrochemical feedstock and their price increase as well as the counterbalancing of the environmental problems. As novel bio-based monomers used in polyesters synthesis, two families, namely 1,4:3,6-dianhydrohexitols and furanics were prepared for saccharidic renewable resources. The present work deals with a detail investigation on the synthesis of poly(ethylene-co-isosorbide terephthalate-co-furoate) (PEITF) by melt polycondensation of dimethylterephtalate (DMT), 5,5’-isopropylidene-bis (ethyl 2-furoate) (DEF) ethan-1,2-diol (ED) and isosorbide (IS). Polycondensationwas achieved in two steps: (i) the formation of a hydroxyethylterminated oligomer by reaction of starting diester mixture with excess ED and, (ii) a polycondensation step with elimination of ED was used to obtain high molar mass copolyesters. Copolymers of various compositions were synthesized and characterized by 1H NMR, SEC, DSC and TGA. The resulting materials are amorphous polymers (Tg = 104–127 °C) with good thermal stability.

Keywords: bio-based monomers, furan, isosrbide, polycondensation

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2029 Synthesis and Characterization of Zr and V Co-Doped BaTiO₃ Ceramic

Authors: Kanta Maan Sangwan, Neetu Ahlawat, Rajender Singh Kundu

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BaZrTiO3 ceramics having high dielectric constant and low dielectric loss are interesting material for being used as commercial capacitor applications. BZT (BaZrTiO3) has attracted attentions for their many applications for the microwave technology as the doping of Zr4+ on Ti4+ has advantage to the stability of the system. In the present work, co-doping of Zr and V with BaTiO3 ceramics was synthesized by the conventional solid state reaction technique and sintered at 1200 K for 6 hours, and their structural and ferroelectric properties were studied. The XRD (x-ray diffraction) pattern of BZT (BaZrTiO3) ceramics shows that the crystalline sample is single phase tetragonal structure with P4mm space group. The result revealed that Zr ion enters the unit cell maintaining the perovskite structure of BZT ceramics and the impedance spectroscopy of the sample performed in selected frequency and temperature range.

Keywords: ferroelectric, impedance spectroscopy, space group, tetragonal

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2028 Photo-Degradation of a Pharmaceutical Product in the Presence of a Catalyst Supported on a Silicoaluminophosphate Solid

Authors: I. Ben Kaddour, S. Larbaoui

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Since their first synthesis in 1984, silicoaluminophosphates have proven their effectiveness as a good adsorbent and catalyst in several environmental and energy applications. In this work, the photocatalytic reaction of the photo-degradation of a pharmaceutical product in water was carried out in the presence of a series of materials based on titanium oxide, anatase phase, supported on the microporous framework of the SAPO4-5 at different levels, under ultraviolet light. These photo-catalysts were characterized by different physicochemical analysis methods in order to determine their structural, textural, and morphological properties, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), microscopy scanning electronics (SEM), nitrogen adsorption measurements, UV-visible diffuse reflectance spectroscopy (UV-Vis-DRS). In this study, liquid chromatography coupled with spectroscopy of mass (LC-MS) was used to determine the nature of the intermediate products formed during the photocatalytic degradation of DCF.

Keywords: photocatalysis, titanium dioxide, SAPO-5, diclofenac

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2027 Mannose-Functionalized Lipopolysaccharide Nanoparticles for Macrophage-Targeted Dual Delivery of Rifampicin and Isoniazid

Authors: Mumuni Sumaila, Viness Pillay, Yahya E. Choonara, Pradeep Kumar, Pierre P. Kondiah

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Tuberculosis (TB) remains a serious challenge to public health globally, despite every effort put together to curb the disease. Current TB therapeutics available have proven to be inefficient due to a multitude of drawbacks that range from serious adverse effects/drug toxicity to inconsistent bioavailability, which ultimately contributes to the emergence of drug-resistant TB. An effective ‘cargo’ system designed to cleverly deliver therapeutic doses of anti-TB drugs to infection sites and in a sustained-release manner may provide a better therapeutic choice towards winning the war against TB. In the current study, we investigated mannose-functionalized lipopolysaccharide hybrid nanoparticles for safety and efficacy towards macrophage-targeted simultaneous delivery of the two first-line anti-TB drugs, rifampicin (RF) and isoniazid (IS). RF-IS-loaded lipopolysaccharide hybrid nanoparticles were fabricated using the solvent injection technique (SIT), incorporating soy lecithin (SL) and low molecular weight chitosan (CS) as the lipid and polysaccharide components, respectively. Surface-functionalized nanoparticles were obtained through the reaction of the aldehyde group of mannose with free amine functionality present at the surface of the nanoparticles. The functionalized nanocarriers were spherical with average particle size and surface charge of 107.83 nm and +21.77 mV, respectively, and entrapment efficiencies (EE) were 53.52% and 69.80% for RF and IS, respectively. FTIR spectrum revealed high-intensity bands between 1663 cm⁻¹ and 1408 cm⁻¹ wavenumbers (absent in non-functionalized nanoparticles), which could be attributed to the C=N stretching vibration produced by the formation of Schiff’s base (–N=CH–) during the mannosylation reaction. In vitro release studies showed a sustained-release profile for RF and IS, with less than half of the total payload released over a 48-hour period. The nanocarriers were biocompatible and safe, with more than 80% cell viability achieved when incubated with RAW 264.7 cells at concentrations 30 to 500 μg/mL over a 24-hour period. Cellular uptake studies (after a 24-hour incubation period with the murine macrophage cells, RAW 264.7) revealed a 13- and a 9-fold increase in intracellular accumulation of RF and IS, respectively, when compared with the unformulated RF+IS solution. A 6- and a 3-fold increase in intracellular accumulation of RF and IS, respectively, were observed when compared with the non-functionalized nanoparticles. Furthermore, fluorescent microscopy images showed nanoparticle internalization and accumulation within the RAW 264.7 cells, which was more significant in the mannose-functionalized system compared to the non-functionalized nanoparticles. The overall results suggested that the fabricated mannose-functionalized lipopolysaccharide nanoparticles are a safe and promising platform for macrophage-targeted delivery of anti-TB therapeutics. However, in vivo pharmacokinetic/pharmacodynamics studies are required to further substantiate the therapeutic efficacy of the nanosystem.

Keywords: anti-tuberculosis therapeutics, hybrid nanosystem, lipopolysaccharide nanoparticles, macrophage-targeted delivery

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2026 Immobilization of β-Galactosidase from Kluyveromyces Lactis on Polyethylenimine-Agarose for Production of Lactulose

Authors: Carlos A. C. G. Neto, Natan C. G. Silva, Thais O. Costa, Luciana R. B. Goncalves, Maria v. P. Rocha

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Galactosidases are enzymes responsible for catalyzing lactose hydrolysis reactions and also favoring transgalactosylation reactions for the production of prebiotics, among which lactulose stands out. These enzymes, when immobilized, can have some enzymatic characteristics substantially improved, and the coating of supports with multifunctional polymers in immobilization processes is a promising alternative in order to extend the useful life of the biocatalysts, for example, the coating with polyethyleneimine (PEI). PEI is a flexible polymer that suits the structure of the enzyme, giving greater stability, especially for multimeric enzymes such as β-galactosidases and also protects it from environmental variations, for example, pH and temperature. In addition, it can substantially improve the immobilization parameters and also the efficiency of enzymatic reactions. In this context, the aim of the present work was first to develop biocatalysts of β-galactosidase from Kluyveromyces lactis immobilized on PEI coated agarose, determining the immobilization parameters, its operational and thermal stability, and then to apply it in the hydrolysis of lactose and synthesis of lactulose, using whey as a substrate. This immobilization strategy was chosen in order to improve the catalytic efficiency of the enzyme in the transgalactosylation reaction for the production of prebiotics, and there are few studies with β-galactosidase from this strain. The immobilization of β-galactosidase in agarose previously functionalized with 48% (w/v) glycidol and then coated with 10% (w/v) PEI solution was evaluated using an enzymatic load of 10 mg/g of protein. Subsequently, the hydrolysis and transgalactosylation reactions were conducted at 50 °C, 120 RPM for 20 minutes, using whey (66.7 g/L of lactose) supplemented with 133.3 g/L fructose at a ratio of 1:2 (lactose/fructose). Operational stability studies were performed in the same conditions for 10 cycles. Thermal stabilities of biocatalysts were conducted at 50 ºC in 50 mM phosphate buffer, pH 6.6, with 0.1 mM MnCl2. The biocatalysts whose supports were coated were named AGA_GLY_PEI_GAL, and those that were not coated were named AGA_GLY_GAL. The coating of the support with PEI considerably improved immobilization yield (2.6-fold), the biocatalyst activity (1.4-fold), and efficiency (2.2-fold). The biocatalyst AGA_GLY_PEI_GAL was better than AGA_GLY_GAL in hydrolysis and transgalactosylation reactions, converting 88.92% of lactose at 5 min of reaction and obtaining a residual concentration of 5.24 g/L. Besides that, it was produced 13.90 g/L lactulose in the same time interval. AGA_GLY_PEI_GAL biocatalyst was stable during the 10 cycles evaluated, converting approximately 80% of lactose and producing 10.95 g/L of lactulose even after the tenth cycle. However, the thermal stability of AGA_GLY_GAL biocatalyst was superior, with a half-life time 5 times higher, probably because the enzyme was immobilized by covalent bonding, which is stronger than adsorption (AGA_GLY_PEI_GAL). Therefore, the strategy of coating the supports with PEI has proven to be effective for the immobilization of β-galactosidase from K. lactis, considerably improving the immobilization parameters, as well as the enzyme, catalyzed reactions. In addition, the use of whey as a raw material for lactulose production has proved to be an industrially advantageous alternative.

Keywords: β-galactosidase, immobilization, lactulose, polyethylenimine, whey

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2025 Networked Radar System to Increase Safety of Urban Railroad Crossing

Authors: Sergio Saponara, Luca Fanucci, Riccardo Cassettari, Ruggero Piernicola, Marco Righetto

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The paper presents an innovative networked radar system for detection of obstacles in a railway level crossing scenario. This Monitoring System (MS) is able to detect moving or still obstacles within the railway level crossing area automatically, avoiding the need of human presence for surveillance. The MS is also connected to the National Railway Information and Signaling System to communicate in real-time the level crossing status. The architecture is compliant with the highest Safety Integrity Level (SIL4) of the CENELEC standard. The number of radar sensors used is configurable at set-up time and depends on how large the level crossing area can be. At least two sensors are expected and up four can be used for larger areas. The whole processing chain that elaborates the output sensor signals, as well as the communication interface, is fully-digital, was designed in VHDL code and implemented onto a Xilinx Virtex 6.

Keywords: radar for safe mobility, railroad crossing, railway, transport safety

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2024 Magnetron Sputtered Thin-Film Catalysts with Low Noble Metal Content for Proton Exchange Membrane Water Electrolysis

Authors: Peter Kus, Anna Ostroverkh, Yurii Yakovlev, Yevheniia Lobko, Roman Fiala, Ivan Khalakhan, Vladimir Matolin

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Hydrogen economy is a concept of low-emission society which harvests most of its energy from renewable sources (e.g., wind and solar) and in case of overproduction, electrochemically turns the excess amount into hydrogen, which serves as an energy carrier. Proton exchange membrane water electrolyzers (PEMWE) are the backbone of this concept. By fast-response electricity to hydrogen conversion, the PEMWEs will not only stabilize the electrical grid but also provide high-purity hydrogen for variety of fuel cell powered devices, ranging from consumer electronics to vehicles. Wider commercialization of PEMWE technology is however hindered by high prices of noble metals which are necessary for catalyzing the redox reactions within the cell. Namely, platinum for hydrogen evolution reaction (HER), running on cathode, and iridium for oxygen evolution reaction (OER) on anode. Possible way of how to lower the loading of Pt and Ir is by using conductive high-surface nanostructures as catalyst supports in conjunction with thin-film catalyst deposition. The presented study discusses unconventional technique of membrane electron assembly (MEA) preparation. Noble metal catalysts (Pt and Ir) were magnetron sputtered in very low loadings onto the surface of porous sublayers (located on gas diffusion layer or directly on membrane), forming so to say localized three-phase boundary. Ultrasonically sprayed corrosion resistant TiC-based sublayer was used as a support material on anode, whereas magnetron sputtered nanostructured etched nitrogenated carbon (CNx) served the same role on cathode. By using this configuration, we were able to significantly decrease the amount of noble metals (to thickness of just tens of nanometers), while keeping the performance comparable to that of average state-of-the-art catalysts. Complex characterization of prepared supported catalysts includes in-cell performance and durability tests, electrochemical impedance spectroscopy (EIS) as well as scanning electron microscopy (SEM) imaging and X-ray photoelectron spectroscopy (XPS) analysis. Our research proves that magnetron sputtering is a suitable method for thin-film deposition of electrocatalysts. Tested set-up of thin-film supported anode and cathode catalysts with combined loading of just 120 ug.cm⁻² yields remarkable values of specific current. Described approach of thin-film low-loading catalyst deposition might be relevant when noble metal reduction is the topmost priority.

Keywords: hydrogen economy, low-loading catalyst, magnetron sputtering, proton exchange membrane water electrolyzer

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2023 The Affective Motivation of Women Miners in Ghana

Authors: Adesuwa Omorede, Rufai Haruna Kilu

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Affective motivation (motivation that is emotionally laden usually related to affect, passion, emotions, moods) in the workplace stimulates individuals to reinforce, persist and commit to their task, which leads to the individual and organizational performance. This leads individuals to reach goals especially in situations where task are highly challenging and hostile. In such situations, individuals are more disposed to be more creative, innovative and see new opportunities from the loopholes in their workplace. However, when individuals feel displaced and less important, an adverse reaction may suffice which may be detrimental to the organization and its performance. One sector where affective motivation is eminently present and relevant, is the mining industry. Due to its intense work environment; mostly dominated by men and masculinity cultures; and deliberate exclusion of women in this environment which, makes the women working in these environments to feel marginalized. In Ghana, the mining industry is mostly seen as a very physical environment especially underground and mostly considerd as 'no place for a woman'. Despite the fact that these women feel less 'needed' or 'appreciated' in such environments, they still have to juggle between intense work shifts; face violence and other health risks with their families, which put a strain on their affective motivational reaction. Beyond these challenges, however, several mining companies in Ghana today are working towards providing a fair and equal working situation for both men and women miners, by recognizing them as key stakeholders, as well as including them in the stages of mining projects from the planning and designing phase to the evaluation and implementation stage. Drawing from the psychology and gender literature, this study takes a narrative approach to identify and understand the shifting gender dynamics within the mine works in Ghana, occasioning a change in background disposition of miners, which leads to more women taking up mine jobs in the country. In doing so, a qualitative study was conducted using semi-structured interviews from Ghana. Several women working within the mining industries in Ghana shared their experiences and how they felt and still feel in their workplace. In addition, archival documents were gathered to support the findings. The results suggest a change in enrolment regimes in a mining and technology university in Ghana, making room for a more gender equal enrolments in the university. A renowned university that train and feed mine work professional into the industry. The results further acknowledge gender equal and diversity recruitment policies and initiatives among the mining companies of Ghana. This study contributes to the psychology and gender literature by highlighting the hindrances women face in the mining industry as well as highlighting several of their affective reactions towards gender inequality. The study also provides several suggestions for decision makers in the mining industry of what can be done in the future to reduce the gender inequality gap within the industry.

Keywords: affective motivation, gender shape shifting, mining industry, women miners

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2022 Establishing Multi-Leveled Computability as a Living-System Evolutionary Context

Authors: Ron Cottam, Nils Langloh, Willy Ranson, Roger Vounckx

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We start by formally describing the requirements for environmental-reaction survival computation in a natural temporally-demanding medium, and develop this into a more general model of the evolutionary context as a computational machine. The effect of this development is to replace deterministic logic by a modified form which exhibits a continuous range of dimensional fractal diffuseness between the isolation of perfectly ordered localization and the extended communication associated with nonlocality as represented by pure causal chaos. We investigate the appearance of life and consciousness in the derived general model, and propose a representation of Nature within which all localizations have the character of quasi-quantal entities. We compare our conclusions with Heisenberg’s uncertainty principle and nonlocal teleportation, and maintain that computability is the principal influence on evolution in the model we propose.

Keywords: computability, evolution, life, localization, modeling, nonlocality

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2021 Enhancement of Mechanical and Biological Properties in Wollastonite Bioceramics by MgSiO3 Addition

Authors: Jae Hong Kim, Sang Cheol Um, Jong Kook Lee

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Strong and biocompatible wollastonite (CaSiO3) was fabricated by pressureless sintering at temperature range of 1250~ 1300 ℃ and phase transition of to β-wollastonite with an addition of MgSiO3. Starting pure α-wollastonite powder were prepared by solid state reaction, and MgSiO3 powder was added to α-wollastonite powder to induce the phase transition α to β-wollastonite over 1250℃. Sintered wollastonite samples at 1250℃ with 5 and 10 wt% MgSiO3 were α+β phase and β phase respectively, and showed higher densification rate than that of α or β-wollastonite, which are almost the same as the theoretical density. Hardness and Young’s modulus of sintered wollastonite were dependent on the apparent density and the amount of β-wollastonite. Young’s modulus (78GPa) of β-wollastonite added 10 wt% MgSiO3 was almost double time of sintered α-wollastonite. From the in-vitro test, biphasic (α+β) wollastonite with 5wt% MgSiO3 addition had good bioactivity in simulated body fluid solution.

Keywords: β-wollastonite, high density, MgSiO3, phase transition

Procedia PDF Downloads 585
2020 Estimation of the External Force for a Co-Manipulation Task Using the Drive Chain Robot

Authors: Sylvain Devie, Pierre-Philippe Robet, Yannick Aoustin, Maxime Gautier

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The aim of this paper is to show that the observation of the external effort and the sensor-less control of a system is limited by the mechanical system. First, the model of a one-joint robot with a prismatic joint is presented. Based on this model, two different procedures were performed in order to identify the mechanical parameters of the system and observe the external effort applied on it. Experiments have proven that the accuracy of the force observer, based on the DC motor current, is limited by the mechanics of the robot. The sensor-less control will be limited by the accuracy in estimation of the mechanical parameters and by the maximum static friction force, that is the minimum force which can be observed in this case. The consequence of this limitation is that industrial robots without specific design are not well adapted to perform sensor-less precision tasks. Finally, an efficient control law is presented for high effort applications.

Keywords: control, identification, robot, co-manipulation, sensor-less

Procedia PDF Downloads 164
2019 COVID-19 Impact: How the Pandemic Changed the Fashion Industry

Authors: Akshata Patel, Reenu Singh

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This paper focuses on current and upcoming fashion trends and global impact on the fashion industry due to the COVID-19 pandemic. The pandemic has had a major impact on the fashion industry worldwide. At the same time, the fashion market also faces challenges in consumer demand. As the supply chain and distribution channels are interconnected, this outbreak has a global impact due to travel restrictions and raw materials shortages. Given that this particular period represents an unprecedented market situation with almost no prior research on how the industry will recover from such a crisis and mold back to its original form, this research aims to propose new possibilities by evaluating the framework of specific segments. Based on the analysis and extensive literature review, the study develops a conceptual model that will illustrate the various connections among the different segments of the fashion industry. The findings provide actionable considerations for fashion industry pupils when implementing appropriate strategies to prevent unfavourable outcomes during times of crisis, such as the COVID-19 outbreak.

Keywords: COVID-19, fashion industry, global impact, new possibilities, pandemic

Procedia PDF Downloads 291
2018 Efficiency of Modified Granular Activated Carbon Coupled with Membrane Bioreactor for Trace Organic Contaminants Removal

Authors: Mousaab Alrhmoun, Magali Casellas, Michel Baudu, Christophe Dagot

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The aim of the study is to improve removal of trace organic contaminants dissolved in activated sludge by the process of filtration with membrane bioreactor combined with modified activated carbon, for a maximum removal of organic compounds characterized by low molecular weight. Special treatment was conducted in laboratory on activated carbon. Tow reaction parameters: The pH of aqueous middle and the type of granular activated carbon were very important to improve the removal and to motivate the electrostatic Interactions of organic compounds with modified activated carbon in addition to physical adsorption, ligand exchange or complexation on the surface activated carbon. The results indicate that modified activated carbon has a strong impact in removal 21 of organic contaminants and in percentage of 100% of the process.

Keywords: activated carbon, organic micropolluants, membrane bioreactor, carbon

Procedia PDF Downloads 326
2017 Upgrading of Bio-Oil by Bio-Pd Catalyst

Authors: Sam Derakhshan Deilami, Iain N. Kings, Lynne E. Macaskie, Brajendra K. Sharma, Anthony V. Bridgwater, Joseph Wood

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This paper reports the application of a bacteria-supported palladium catalyst to the hydrodeoxygenation (HDO) of pyrolysis bio-oil, towards producing an upgraded transport fuel. Biofuels are key to the timely replacement of fossil fuels in order to mitigate the emissions of greenhouse gases and depletion of non-renewable resources. The process is an essential step in the upgrading of bio-oils derived from industrial by-products such as agricultural and forestry wastes, the crude oil from pyrolysis containing a large amount of oxygen that requires to be removed in order to create a fuel resembling fossil-derived hydrocarbons. The bacteria supported catalyst manufacture is a means of utilizing recycled metals and second life bacteria, and the metal can also be easily recovered from the spent catalysts after use. Comparisons are made between bio-Pd, and a conventional activated carbon supported Pd/C catalyst. Bio-oil was produced by fast pyrolysis of beechwood at 500 C at a residence time below 2 seconds, provided by Aston University. 5 wt % BioPd/C was prepared under reducing conditions, exposing cells of E. coli MC4100 to a solution of sodium tetrachloropalladate (Na2PdCl4), followed by rinsing, drying and grinding to form a powder. Pd/C was procured from Sigma-Aldrich. The HDO experiments were carried out in a 100 mL Parr batch autoclave using ~20g bio-crude oil and 0.6 g bio-Pd/C catalyst. Experimental variables investigated for optimization included temperature (160-350C) and reaction times (up to 5 h) at a hydrogen pressure of 100 bar. Most of the experiments resulted in an aqueous phase (~40%) and an organic phase (~50-60%) as well as gas phase (<5%) and coke (<2%). Study of the temperature and time upon the process showed that the degree of deoxygenation increased (from ~20 % up to 60 %) at higher temperatures in the region of 350 C and longer residence times up to 5 h. However minimum viscosity (~0.035 Pa.s) occurred at 250 C and 3 h residence time, indicating that some polymerization of the oil product occurs at the higher temperatures. Bio-Pd showed a similar degree of deoxygenation (~20 %) to Pd/C at lower temperatures of 160 C, but did not rise as steeply with temperature. More coke was formed over bio-Pd/C than Pd/C at temperatures above 250 C, suggesting that bio-Pd/C may be more susceptible to coke formation than Pd/C. Reactions occurring during bio-oil upgrading include catalytic cracking, decarbonylation, decarboxylation, hydrocracking, hydrodeoxygenation and hydrogenation. In conclusion, it was shown that bio-Pd/C displays an acceptable rate of HDO, which increases with residence time and temperature. However some undesirable reactions also occur, leading to a deleterious increase in viscosity at higher temperatures. Comparisons are also drawn with earlier work on the HDO of Chlorella derived bio-oil manufactured from micro-algae via hydrothermal liquefaction. Future work will analyze the kinetics of the reaction and investigate the effect of bi-metallic catalysts.

Keywords: bio-oil, catalyst, palladium, upgrading

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2016 Preparation and Characterization of Photocatalyst for the Conversion of Carbon Dioxide to Methanol

Authors: D. M. Reddy Prasad, Nur Sabrina Binti Rahmat, Huei Ruey Ong, Chin Kui Cheng, Maksudur Rahman Khan, D. Sathiyamoorthy

Abstract:

Carbon dioxide (CO2) emission to the environment is inevitable which is responsible for global warming. Photocatalytic reduction of CO2 to fuel, such as methanol, methane etc. is a promising way to reduce greenhouse gas CO2 emission. In the present work, Bi2S3/CdS was synthesized as an effective visible light responsive photocatalyst for CO2 reduction into methanol. The Bi2S3/CdS photocatalyst was prepared by hydrothermal reaction. The catalyst was characterized by X-ray diffraction (XRD) instrument. The photocatalytic activity of the catalyst has been investigated for methanol production as a function of time. Gas chromatograph flame ionization detector (GC-FID) was employed to analyze the product. The yield of methanol was found to increase with higher CdS concentration in Bi2S3/CdS and the maximum yield was obtained for 45 wt% of Bi2S3/CdS under visible light irradiation was 20 μmole/g. The result establishes that Bi2S3/CdS is favorable catalyst to reduce CO2 to methanol.

Keywords: photocatalyst, CO2 reduction, methanol, visible light, XRD, GC-FID

Procedia PDF Downloads 504
2015 Port Governance Model by International Freight Forwarders’ Point of View: A Study at Port of Santos - Brazil

Authors: Guilherme B. B. Vieira, Rafael M. da Silva, Eliana T. P. Senna, Luiz A. S. Senna, Francisco J. Kliemann Neto

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Due to the importance of ports to trade and economic development of the regions in which they are inserted, in recent decades the number of studies devoted to this subject has increased. Part of these studies consider the ports as business agglomerations and focuses on port governance. This is an important approach since the port performance is the result of activities performed by actors belonging to the port-logistics chain, which need to be properly coordinated. This coordination takes place through a port governance model. Given this context, this study aims to analyze the governance model of the port of Santos from the perspective of port customers. To do this, a closed-ended questionnaire based on a conceptual model that considers the key dimensions associated with port governance was applied to the international freight forwarders that operate in the port. The results show the applicability of the considered model and highlight improvement opportunities to be implemented at the port of Santos.

Keywords: port governance, model, Port of Santos, customers’ perception

Procedia PDF Downloads 455
2014 Effect of Cadmium on Oxidative Enzymes Activity in Persian Clover (Trifolium resupinatum L.)

Authors: Homayun Ghasemi, Mojtaba Yousefirad, Mozhgan Farzamisepehr

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Heavy metals are among soil pollutant resources that in case of accumulation in the soil and absorption by the plant, enter into the food chain and poison the plants or the people who consume those plants. This research was performed in order to examine the role of cadmium as a heavy metal in the activity of catalase and peroxidase as well as protein concentration in Trifolium resupinatum L. based on a randomized block design with three repetitions. The used treatments included consumption of Cd (NO3)2 at four levels, namely, 0, 100, 200, and 300 ppm. The plants under study were treated for 10 days. The results of the study showed that catalase activity decreased by the increase of cadmium. Moreover, peroxidase activity increased by an increase inthe consumption of cadmium. The analysis of protein level showed that plantlet protein decreased in high cadmium concentrations. The findings also demonstrated that cadmium concentration in roots was higher than in shoots.

Keywords: catalase, heavy metal, peroxidase, protein

Procedia PDF Downloads 250