Search results for: Material Culture

Authors: Mohammad Imani, JabraeilNasl Seraji, Abolfazl Zakerian

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Background: Reaction time is the amount of time it takes to respond to a stimulus. In fact The time that passes between the introduction of a stimulus and the reaction by the subject to that stimulus. The aim of this interventional study is evaluation of bright light effects on concentration and diffuse attention reaction time, tension, angry, fatigue and alertness among shift workers. There are several incentives that can reduce the reaction time or added. Bright light as one of the environmental factors can reduce reaction time. Material &Method: This cross-sectional descriptive study was conducted in 1391, in 88 subjects (44 Fixed morning worker and 44 shift worker ) In a 24 h time (13-16-19-22-1-4-7-10) in an ordinary light situation after a randomly selected sample size calculation, concentration and diffuse attention test (reaction time) has been done. After intervention and using of bright light (4500lux), again reaction time test was done. After analyzing by ElISA method obtained data were analyzed by statistical software SPSS 19 and using T-test and ANOVA statistical analysis. Results: Between average of reaction time tests in ordinary light exposed to fixed morning workers and bright light exposed to shift worker, with 95% CI, (P>%5) there was no significant relationship. After the intervention and the use of bright light (4500 lux),between average of concentration and diffused attention reaction time tests in ordinary light exposure on the fixed morning workers and bright light exposure shift workers with 95% CI, (P<5%) there was significant relationship. Conclusion: In sometimes of 24 h during ordinary light exposure concentration and diffused attention reaction time has changed in shift workers. After intervention, during bright light (4500lux) exposure as a light shower, focused and diffuse attention reaction time, tension ,angry and fatigue decreased.

Keywords: bright light, reaction time, tension, angry, fatigue, alertness

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Authors: Tabin Millo, Khoob Chand, Ashok Kumar Jaiswal

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Introduction: Various kinds of violence and offences are related to alcohol consumption by the offenders. The relationship between alcohol and violence is complex. But its study is important to achieve understanding of violence as well as alcohol related behavior. This study was done to know the blood alcohol concentration in people involved in various offences and its demographic pattern. The study was carried out in the forensic toxicology laboratory, department of Forensic Medicine, All India Institute of Medical Sciences, New Delhi, India. Material and methods: The blood samples were collected from the arrested people shortly after the commission of the offence by the emergency medical officers in the emergency department and forwarded to the forensic toxicology laboratory through the investigating officer. The blood samples were collected in EDTA vial with sodium fluoride preservative. The samples were analyzed by using gas chromatography with head space (GC-HS), which is ideal for alcohol estimation. The toxicology reports were given within a week. The data of seven years (2011-17) were analyzed for its alcohol concentration, associated crimes and its demographic pattern. Analysis and conclusion: Total 280 samples were analyzed in the period of 2011-2017. All were males except one female who was a bar dancer. The maximum cases were in the age group of 21-30 years (124 cases). The type of offences involved were road traffic accidents (RTA), assault cases, drunken driving, drinking in public place, drunk on duty, sexual offence, bestiality, eve teasing, fall etc. The maximum cases were of assault (75 cases) followed by RTA (64 cases). The maximum cases were in the alcohol concentration range of 101-150mg% (58 cases) followed by 51-100mg% (52 cases). The maximum blood alcohol level detected was 391.51 mg%, belonging to a security guard found unconscious. This study shows that alcohol consumption is associated with various kinds of violence and offences in society.

Keywords: alcohol, crime, toxicology, violence

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Authors: Rong-Yang Lai, Jia-Yu Wu, Chih-Han Chang, Yung-Chung Chen

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The dental bridge is one of the clinical methods of the treatment for missing teeth. The dental bridge is generally designed for two layers, containing the inner layer of the framework(zirconia) and the outer layer of the porcelain-fused to framework restorations. The design of a conventional bridge is generally based on the antagonist tooth profile so that the framework evenly indented by an equal thickness from outer contour. All-ceramic dental bridge made of zirconia have well demonstrated remarkable potential to withstand a higher physiological occlusal load in posterior region, but it was found that there is still the risk of all-ceramic bridge failure in five years. Thus, how to reduce the incidence of failure is still a problem to be solved. Therefore, the objective of this study is to develop mechanical designs for all-ceramic dental bridges framework by reducing the stress and enhancing fracture resistance under given loading conditions by finite element method. In this study, dental design software is used to design dental bridge based on tooth CT images. After building model, Bi-directional Evolutionary Structural Optimization (BESO) Method algorithm implemented in finite element software was employed to analyze results of finite element software and determine the distribution of the materials in dental bridge; BESO searches the optimum distribution of two different materials, namely porcelain and zirconia. According to the previous calculation of the stress value of each element, when the element stress value is higher than the threshold value, the element would be replaced by the framework material; besides, the difference of maximum stress peak value is less than 0.1%, calculation is complete. After completing the design of dental bridge, the stress distribution of the whole structure is changed. BESO reduces the peak values of principle stress of 10% in outer-layer porcelain and avoids producing tensile stress failure.

Keywords: dental bridge, finite element analysis, framework, automatic program

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Authors: Koyar Rane

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Nano- to submicron size particles of narrow particle size distribution of semi-conducting TiO₂, ZnO, NiO, CuO, Fe₂O₃ have been synthesized by novel hydrazine method and tested for their gas sensing, photocatalytic and bactericidal activities and the behavior found to be enhanced when the oxides in the thin film forms, that obtained in a specially built spray pyrolysis reactor. Hydrazine method is novel in the sense, say, the UV absorption edge of the white pigment grade wide band gap (~3.2eV) TiO₂ and ZnO shifted to the visible region turning into yellowish particles, indicating modification occurring the band structure. The absorption in the visible region makes these oxides visible light sensitive photocatalysis in degrading pollutants, especially the organic dyes which otherwise increase the chemical oxygen demand of the drinking water, enabling the process feasible not under the harsh energetic UV radiation regime. The electromagnetic radiations on irradiation produce electron-hole pairs Semiconductor + hν → e⁻ + h⁺ The electron-hole pairs thus produced form Reactive Oxygen Species, ROS, on the surface of the semiconductors, O₂(adsorbed)+e⁻ → O₂• - superoxide ion OH-(surface)+h⁺ →•OH - Hydroxyl radical The ROS attack the organic material and micro-organisms. Our antibacterial studies indicate the metal oxides control the Biological Oxygen Demand (BOD) of drinking water which had beyond the safe level normally found in the municipal supply. Metal oxides in the thin film form show overall enhanced properties and the films are reusable. The results of the photodegradation and antibactericidal studies are discussed. Gas sensing studies too have been done to find the versatility of the multifunctional metal oxides.

Keywords: hydrazine method, visible light sensitive, photo-degradation of dyes, water/airborne pollutant

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Authors: Chia-Wen Yeh, Ting-Sheng Lin, Chih-Han Chang

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Pressure garment has been used to prevent and treat the hypertrophic scars following serious burns since 1970s. The use of pressure garment is believed to hasten the maturation process and decrease the highness of scars. Pressure garment is custom made by reducing circumferential measurement of the patient by 10%~20%, called Reduction Factor. However the exact reducing value used depends on the subjective judgment of the therapist and the feeling of patients throughout the try and error process. The Laplace Law can be applied to calculate the pressure from the dimension of the pressure garment by the circumferential measurements of the patients and the tension profile of the fabrics. The tension profile currently obtained neglects the stress relaxation and hysteresis effect within most elastic fabrics. The purpose of this study was to investigate the influence of the tension attenuation, from stress relaxation and hysteresis effect of the fabrics. Samples of pressure garment were obtained from Sunshine Foundation Organization, a nonprofit organization for burn patients in Taiwan. The wall tension profile of pressure garments were measured on a material testing system. Specimens were extended to 10% of the original length, held for 1 hour for the influence of the stress relaxation effect to take place. Then, specimens were extended to 15% of the original length for 10 seconds, then reduced to 10% to simulate donning movement for the influence of the hysteresis effect to take place. The load history was recorded. The stress relaxation effect is obvious from the load curves. The wall tension is decreased by 8.5%~10% after 60mins of holding. The hysteresis effect is obvious from the load curves. The wall tension is increased slightly, then decreased by 1.5%~2.5% and lower than stress relaxation results after 60mins of holding. The wall tension attenuation of the fabric exists due to stress relaxation and hysteresis effect. The influence of hysteresis is more than stress relaxation. These effect should be considered in order to design and evaluate the pressure of pressure garment more accurately.

Keywords: hypertrophic scars, hysteresis, pressure garment, stress relaxation

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Authors: Anna Strakowska, Marian Zaborski

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This abstract focuses an overview of the methods used to create self-healing silicone composites. It has been shown how incorporating of polyhedral oligomeric silsesquioxanes (POSS) molecules with acid and basic groups to silicone rubber affects the barrier properties, mechanical properties in room and reduced temperature or the influence on relaxation rates of the methylvinylsilicone rubber vulcanizates. Moreover, the presence of silsesquioxanes, their content and the way of composites preparing affect the amount of ionic bonds, as indicated by dynamic - mechanical thermal analysis (DMTA) as well as measurements of equilibrium swelling in toluene. The aim of this work was to study the influence of concentration and different functional groups types selected silsesquioxanes compounds on self-healing effect of silicone rubber and obtain elastomers with good barrier and mechanical properties. Composites based on the methylvinylsilicone rubber with fumed silica as the fillers were manufactured and studied. To obtain self-healing effect various silsesquioxanes with amino and acid groups were used. Every tested sample demonstrated the ability to the self-treatment. The most significant effect was observed for system containing amic-acid isobytyl POSS/ aminopropylisobutyl POSS. Composite with this silsesquioxanes was exhibited the best improvement of gas permeability after heal. Moreover, the addition of POSS with acid and basic groups clearly affects the mechanical properties of the vulcanizates. The most significant effect was observed for the composite material consisting of amic-acid isobytyl POSS / aminoethylaminopropylisobutyl POSS, which tensile strength was even greater than the reference vulcanizate with fumed silica. The development of autonomous self-healing materials could have an enormous influence on all industry branches from motorization to power industry. Self-repairing materials would have a massive impact on lengthening product lifetimes, increasing safety, and lowering product costs by reducing maintenance requirements.

Keywords: barrier properties, mechanical properties, POSS, self-healing composites

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Authors: Sandrine Cardinal, Jean-Marc Pelletier, Guang Xie, Florian Mercier, Florent Delmas

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Bulk metallic glasses exhibit several superior properties, compared to their corresponding crystalline counterpart, such as high strength, high elastic limit or good corrosion resistance. Therefore they can be considered as good candidates for structural applications in many sectors. However, they are generally brittle and do not exhibit plastic deformation at room temperature. These materials are mainly obtained by rapid cooling from a liquid state to prevent crystallization, which limits their size. To overcome these two drawbacks: fragility and limited dimensions, composite metallic glass matrix reinforced by a second phase whose role is to slow crack growth are developed. Concerning the limited size of the pieces, the proposed solution is to get the material from amorphous powders by densifying under load. In this study, Cu50Zr45Al5 bulk metallic glassy matrix composites (MGMCs) containing different volume fraction (Vf) of Zr crystalline particles were manufactured by spark plasma sintering (SPS). Microstructure, thermal stability and mechanical properties of the MGMCs were investigated. Matrix of the composites remains a fully amorphous phase after consolidation at 420°C under 600 MPa. A good dispersion of the particles in the glassy matrix is obtained. Results show that the compressive strength decreases with Vf : 1670 MPa (Vf=0%) to 1300MPa (Vf=30%), the elastic modulus decreases but only slighty respectively 97.3GPa and 94.5 GPa and plasticity is improved from 0 to 4%. Fractographic investigation indicates a good bonding between amorphous and crystalline particles. In conclusion, present study has demonstrated that SPS method is useful for the synthesis of the bulk glassy composites. Large controlled microstructure specimens with interesting ductility can be obtained compared with others methods.

Keywords: composite, mechanical properties, metallic glasses, spark plasma sintering

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Authors: Kenichi Hirota, Jifeng Wang, Sadao Araki, Koji Endo, Hideki Yamamoto

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Zirconium (Zr) has been used as a fuel cladding tube for nuclear reactors, because of the excellent corrosion resistance and the low adsorptive material for neutron. Generally speaking, the natural resource of Zr is often containing Hf that has similar properties. The content of Hf in the Zr resources is about 2~4 wt%. In the industrial use, the content of Hf in Zr resources should be lower than the 100 ppm. However, the separation of Zr and Hf is not so easy, because of similar chemical and physical properties such as melting point, boiling point and things. Solvent extraction method has been applied for the separation of Zr and Hf from Zr natural resources. This method can separate Hf with high efficiency (Hf < 100ppm), however, it needs much amount of organic solvents for solvent extraction and the cost of its disposal treatment is high. Therefore, we attached attention for the fractional crystallization. This separation method depends on the solubility difference of Zr and Hf in the solvent. In this work, hexafluorozirconate (hafnate) (K2Zr(Hf)F6) was used as model compound. Solubility of K2ZrF6 in water showed lower than that of K2HfF6. By repeating of this treatment, it is possible to purify Zr, practically. In this case, 16-18 times of recrystallization stages were needed for its high purification. The improvement of the crystallization process was carried out in this work. Water, hydrofluoric acid (HF) and hydrofluoric acid (HF) +hydrochloric acid (HCl) mixture were chosen as solvent for dissolution of Zr and Hf. In the experiment, 10g of K2ZrF6 was added to each solvent of 100mL. Each solution was heated for 1 hour at 353K. After 1h of this operation, they were cooled down till 293K, and were held for 5 hours at 273K. Concentration of Zr or Hf was measured using ICP analysis. It was found that Hf was separated from Zr-Hf mixed compound with high efficiency, when HF-HCl solution was used for solvent of crystallization. From the comparison of the particle size of each crystal by SEM, it was confirmed that the particle diameter of the crystal showed smaller size with decreasing of Hf content. This paper concerned with purification of Zr from Zr-Hf mixture using crystallization method.

Keywords: crystallization, zirconium, hafnium, separation

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Authors: Robin Anderson, Elizabeth Latham, David Nisbet

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Propagation and dissemination of antimicrobial resistant and pathogenic microbes from spoiled silages and composts represents a serious public health threat to humans and animals. In the present study, the antimicrobial activity of the short chain nitro-compound, 2-nitro-1-propanol (9 mM) as well as the medium chain fatty acid, lauric acid, and its glycerol monoester, monolaurin, (each at 25 and 17 µmol/mL, respectfully) were investigated against select pathogenic and multi-drug resistant antimicrobial resistant Gram-positive bacteria common to spoiled silages and composts. In an initial study, we found that growth rates of a multi-resistant Enterococcus faecalis (expressing resistance against erythromycin, quinupristin/dalfopristin and tetracycline) and Staphylococcus aureus strain 12600 (expressing resistance against erythromycin, linezolid, penicillin, quinupristin/dalfopristin and vancomycin) were more than 78% slower (P < 0.05) by 2-nitro-1-propanol treatment during culture (n = 3/treatment) in anaerobically prepared ½ strength Brain Heart Infusion broth at 37oC when compared to untreated controls (0.332 ± 0.04 and 0.108 ± 0.03 h-1, respectively). The growth rate of 2-nitro-1-propanol-treated Listeria monocytogenes was also decreased by 96% (P < 0.05) when compared to untreated controls cultured similarly (0.171 ± 0.01 h-1). Maximum optical densities measured at 600 nm were lower (P < 0.05) in 2-nitro-1-propanol-treated cultures (0.053 ± 0.01, 0.205 ± 0.02 and 0.041 ± 0.01, respectively) than in untreated controls (0.483 ± 0.02, 0.523 ± 0.01 and 0.427 ± 0.01, respectively) for E. faecalis, S. aureus and L. monocytogenes, respectively. When tested against mixed microbial populations during anaerobic 24 h incubation of spoiled silage, significant effects of treatment with 1 mg 2-nitro-1-propanol (approximately 9.5 µmol/g) or 5 mg lauric acid/g (approximately 25 µmol/g) on populations of wildtype Enterococcus and Listeria were not observed. Mixed populations treated with 5 mg monolaurin/g (approximately 17 µmol/g) had lower (P < 0.05) viable cell counts of wildtype enterococci than untreated controls after 6 h incubation (2.87 ± 1.03 versus 5.20 ± 0.25 log10 colony forming units/g, respectively) but otherwise significant effects of monolaurin were not observed. These results reveal differential susceptibility of multi-drug resistant enterococci and staphylococci as well as L. monocytogenes to the inhibitory activity of 2-nitro-1-propanol and the medium chain fatty acid, lauric acid and its glycerol monoester, monolaurin. Ultimately, these results may lead to improved treatment technologies to preserve the microbiological safety of silages and composts.

Keywords: 2-nitro-1-propanol, lauric acid, monolaurin, gram positive bacteria

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Authors: Elena Mugarza, Stephanie Glendinning, Ross Stirling, Colin Davies

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The effects of climate change and increased rainfall events on UK-based infrastructure are observable, with an increasing number being reported on in the national press. The fatal derailment at Stonehaven in 2020 prompted a wider review of Network Rail-owned earthworks assets. The event was indicated by the Rail Accident Investigation Branch (RAIB) to be caused by mis-installed drainage on the adjacent cutting. The slope failure on Snake Pass (public highway A57) was reportedly caused by significant water ingress following numerous storm events and resulted in the road’s closure for several months. This problem is only projected to continue with greater intensity and more prolonged rainfall events forecasted in the future. Subsequently, this project is designed to evaluate effective drainage trench design within infrastructure embankments, considering the capillary barrier phenomenon that may govern their deterioration and resultant failure. Theoretically, the differential between grain sizes of the embankment clays and gravels, customarily used in drainage trenches, would have a limiting effect on infiltration. As such, it is anticipated that the inclusion of an additional material with an intermediate grain size should improve the hydraulic conductivity across the drainage boundary. Multiple drainage designs will be studied using instrumentation within the drain and surrounding clays. Data from the real-world installation at the BIONICS embankment will be collected and compared with laboratory and Finite Element (FE) simulations. This research aims to reduce the risk of infrastructure slope failures by improving the resilience of earthwork drainage and lessening the consequential impact on transportation networks.

Keywords: earthworks, slope drainage, transportation slopes, deterioration, capillary barriers, field study

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Authors: H. S. S Abou El-Mal, A. S. Sherbini, H. E. M. Sallam

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Mode II fracture toughness (KIIc) of fiber reinforced concrete has been widely investigated under various patterns of testing geometries. The effect of fiber type, concrete matrix properties, and testing mechanisms were extensively studied. The area of hybrid fiber addition shows a lake of reported research data. In this paper an experimental investigation of hybrid fiber embedded in high strength concrete matrix is reported. Three different types of fibers; namely steel (S), glass (G), and polypropylene (PP) fibers were mixed together in four hybridization patterns, (S/G), (S/PP), (G/PP), (S/G/PP) with constant cumulative volume fraction (Vf) of 1.5%. The concrete matrix properties were kept the same for all hybrid fiber reinforced concrete patterns. In an attempt to estimate a fairly accepted value of fracture toughness KIIc, four testing geometries and loading types are employed in this investigation. Four point shear, Brazilian notched disc, double notched cube, and double edge notched specimens are investigated in a trial to avoid the limitations and sensitivity of each test regarding geometry, size effect, constraint condition, and the crack length to specimen width ratio a/w. The addition of all hybridization patterns of fiber reduced the compressive strength and increased mode II fracture toughness in pure mode II tests. Mode II fracture toughness of concrete KIIc decreased with the increment of a/w ratio for all concretes and test geometries. Mode II fracture toughness KIIc is found to be sensitive to the hybridization patterns of fiber. The (S/PP) hybridization pattern showed higher values than all other patterns, while the (S/G/PP) showed insignificant enhancement on mode II fracture toughness (KIIc). Four point shear (4PS) test set up reflects the most reliable values of mode II fracture toughness KIIc of concrete. Mode II fracture toughness KIIc of concrete couldn’t be assumed as a real material property.

Keywords: fiber reinforced concrete, Hybrid fiber, Mode II fracture toughness, testing geometry

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Authors: Muhammad Abdul Basit Memon

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The importance of organizational knowledge sharing and knowledge management has been documented in numerous research studies in available literature, since knowledge sharing has been recognized as a founding pillar for superior organizational performance and a source of gaining competitive advantage. Built on this, most of the successful organizations perceive knowledge management and knowledge sharing as a concern of high strategic importance and spend huge amounts on the effective management and sharing of organizational knowledge. However, despite some very serious endeavors, many firms fail to capitalize on the benefits of knowledge sharing because of being unaware of the individual characteristics, interpersonal, organizational and contextual factors that influence knowledge sharing; simply the antecedent to knowledge sharing. The extant literature on antecedents to knowledge sharing, offers a range of antecedents mentioned in a number of research articles and research studies. Some of the previous studies about antecedents to knowledge sharing, studied antecedents to knowledge sharing regarding inter-organizational knowledge transfer; others focused on inter and intra organizational knowledge sharing and still others investigated organizational factors. Some of the organizational antecedents to KS can relate to the characteristics and underlying aspects of knowledge being shared e.g., specificity and complexity of the underlying knowledge to be transferred; others relate to specific organizational characteristics e.g., age and size of the organization, decentralization and absorptive capacity of the firm and still others relate to the social relations and networks of organizations such as social ties, trusting relationships, and value systems. In the same way some researchers have highlighted on only one aspect like organizational commitment, transformational leadership, knowledge-centred culture, learning and performance orientation and social network-based relationships in the organizations. A bulk of the existing research articles on antecedents to knowledge sharing has mainly discussed organizational or environmental factors affecting knowledge sharing. However, the focus, later on, shifted towards the analysis of individuals or personal determinants as antecedents for the individual’s engagement in knowledge sharing activities, like personality traits, attitude and self efficacy etc. For example, employees’ goal orientations (i.e. learning orientation or performance orientation is an important individual antecedent of knowledge sharing behaviour. While being consistent with the existing literature therefore, the antecedents to knowledge sharing can be classified as being individual and organizational. This paper is an endeavor to discuss a conceptual framework of the individual and organizational antecedents to knowledge sharing in the light of the available literature and empirical evidence. This model not only can help in getting familiarity and comprehension on the subject matter by presenting a holistic view of the antecedents to knowledge sharing as discussed in the literature, but can also help the business managers and especially human resource managers to find insights about the salient features of organizational knowledge sharing. Moreover, this paper can help provide a ground for research students and academicians to conduct both qualitative as well and quantitative research and design an instrument for conducting survey on the topic of individual and organizational antecedents to knowledge sharing.

Keywords: antecedents to knowledge sharing, knowledge management, individual and organizational, organizational knowledge sharing

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Authors: Agumah N. B. Orji, M. U., Oru C. M., Ugbo, E. N., Onwuliri E. A Nwakaeze, E. A.,

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ERG11 gene has been reported to be one of the genes whose expression is responsible for resistance of Candida to various triazole drugs, which are first line treatment for candidiasis. This study was carried out to determine the prevalence of Triazole (Fluconazole and voriconazole) resistant Candida albicans expressing ERG11 gene from adult females in Abakaliki. Urine and vaginal swab samples were randomly collected from volunteers after obtaining their consent to participate in the study. A total of 565 adult females participated in the study. A total of 340 urine specimens and 288 vaginal swab specimens were collected. Direct wet mount technique, as well as culture in Trichomonas broth, were used to examine the urine and vaginal swab specimens for the presence of motile Trichomonads. The Trichomonas broth used was selective for both T. vaginalis and C. albicans. Broths that yielded budding yeast cells after microscopy were subcultured on to Sabouraud dextrose agar, after which Germ tube test was carried out to confirm the presence of C. albicans. Biochemical tests, including carbohydrate fermentation and urease utilization, were also performed. Antibiogram of C. albicans isolates obtained from this study was carried out using commercially available azole drugs. Fluconazole and voriconazole were selected as Triazole drugs used for this study. Nystatin was used as a tangential control. An MIC test was carried out with E-strips on some of the resistant C. albicans isolates A total of 6 isolates that resisted all the azole drugs were selected and screened for the presence of ERG11 gene using Reverse transcriptase polymerase chain reaction technique. The total prevalence recorded for C. albicans was 13.0%. Frequency was statistically higher in Pregnant (7.96%) than non pregnant (5.09%) volunteers (X2=0.94 at P=0.05). With respect to clinical samples, frequency was higher in vaginal swabs samples (7.96%) than Urine samples (5.09%) (X2=9.05 at P=0.05). Volunteers within the age group 26-30 years recorded the highest prevalence (4.46%), while those within the age group 36-40 years recorded the lowest at 1.27%(X2=4.34 at P=0.05). In pregnant female participants, the highest frequency was recorded with those in their 3rd trimester (4.14%), while lowest incidence was recorded for those in their first trimester (0.80%). Antibiogram results from this study showed that C. albicans isolates obtained from this study resisted Fluconazole (72%) more than Voriconazole (57%). Only one out of the six selected isolates yielded resistance in the MIC test. Results obtained from the RT-PCR showed that there was no expression of ERG11 gene among the fluconazole resistant isolates of C. albicans. Observed resistance may be due to other factors other than expression of ERG11 gene.

Keywords: candida, ERG11, triazole, nigeria

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Authors: P. T. Ngan

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Purpose: The study aims to answer the question what are motivational conditions that have great influences on employees’ innovative work behaviors by investigating the case of SATAMANKULMA/ Anya Productions Ky in Kuopio, Finland. Design/methodology: The main methodology utilized was the qualitative single case study research, analysis was conducted with an adapted thematic content analysis procedure, created from empirical material that was collected through interviews, observation and document review. Findings: The paper highlights the significance of combining relevant synergistic extrinsic and intrinsic motivations into the organizational motivation system. The findings show that intrinsic drives are essential for the initiation phases while extrinsic drives are more important for the implementation phases of innovative work behaviors. The study also offers the IDEA motivation model-interpersonal relationships & networks, development opportunities, economic constituent and application supports as an ideal tool to optimize business performance. Practical limitations/ implications: The research was only conducted from the perspective of SATAMANKULMA/Anya Productions Ky, with five interviews, a few observations and with several reviewed documents. However, further research is required to include other stakeholders, such as the customers, partner companies etc. Also the study does not offer statistical validity of the findings; an extensive case study or a qualitative multiple case study is suggested to compare the findings and provide information as to whether IDEA model relevant in other types of firms. Originality/value: Neither the innovation nor the human resource management field provides a detailed overview of specific motivational conditions might use to stimulate innovative work behaviors of individual employees. This paper fills that void.

Keywords: employee innovative work behaviors, extrinsic motivation, intrinsic motivation, organizational innovativeness

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Authors: Farusil Najeeb Mullaveettil, Rolanas Dauksevicius

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Cellular structures produced by additive manufacturing have earned wide research attention due to their unique specific strength and energy absorption potentiality. The literature review concludes that pattern type and density are vital parameters that affect the mechanical properties of parts formed by additive manufacturing techniques and have an influence on printing time and material consumption. Fused deposition modeling technique (FDM) is used here to produce Polyvinylidene fluoride (PVDF) parts. In this work, patterns are based on triply periodic minimal surfaces (TPMS) produced by PVDF-based filaments using the FDM technique. PVDF homopolymer filament Fluorinar-H™ and PVDF copolymer filament Fluorinar-C™ are printed with three types of TPMS patterns. The patterns printed are Gyroid, Schwartz diamond, and Schwartz primitive. Tensile, flexural, and compression tests under quasi-static loading conditions are performed in compliance with ISO standards. The investigation elucidates the deformation mechanisms and a study that establishes a relationship between the printed and nominal specimens' dimensional accuracy. In comparison to the examined TPMS pattern, Schwartz diamond showed a higher relative elastic modulus and strength than the other patterns in tensile loading, and the Gyroid pattern showed the highest mechanical characteristics in flexural loading. The concluded results could be utilized to produce informed cellular designs for biomedical and mechanical applications.

Keywords: additive manufacturing, FDM, PVDF, gyroid, schwartz primitive, schwartz diamond, TPMS, tensile, flexural

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Authors: Valeria Velasco, Ana M. Bonilla, José L. Vergara, Alcides Lofa, Jorge Campos, Pedro Rojas-García

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Staphylococcus aureus is both commensal bacterium and opportunistic pathogen that can cause different diseases in humans and can rapidly develop antimicrobial resistance. Since this bacterium has the ability to colonize the nares and skin of humans and animals, there is a risk of contamination of food in different steps of the food chain supply. Emerging strains have been detected in food-producing animals and meat, such as methicillin-resistant S. aureus (MRSA). The aim of this study was to determine the prevalence and oxacillin susceptibility of S. aureus in the pork chain supply in Chile and to suggest some natural antimicrobials for control. A total of 487 samples were collected from pigs (n=332), carcasses (n=85), and retail pork meat (n=70). Presumptive S. aureus colonies were isolated by selective enrichment and culture media. The confirmation was carried out by biochemical testing (Api® Staph) and molecular technique PCR (detection of nuc and mecA genes, associated with S. aureus and methicillin resistance, respectively). The oxacillin (β-lactam antibiotic that replaced methicillin) susceptibility was assessed by minimum inhibitory concentration (MIC) using the Epsilometer test (Etest). A preliminary assay was carried out to test thymol, carvacrol, oregano essential oil (Origanum vulgare L.), Maqui or Chilean wineberry extract (Aristotelia chilensis (Mol.) Stuntz) as anti-staphylococcal agents using the disc diffusion method at different concentrations. The overall prevalence of S. aureus in the pork chain supply reached 33.9%. A higher prevalence of S. aureus was determined in carcasses (56.5%) than in pigs (28.3%) and pork meat (32.9%) (P ≤ 0.05). The prevalence of S. aureus in pigs sampled at farms (40.6%) was higher than in pigs sampled at slaughterhouses (23.3%) (P ≤ 0.05). The contamination of no packaged meat with S. aureus (43.1%) was higher than in packaged meat (5.3%) (P ≤ 0.05). The mecA gene was not detected in S. aureus strains isolated in this study. Two S. aureus strains exhibited oxacillin resistance (MIC ≥ 4µg/mL). Anti-staphylococcal activity was detected in solutions of thymol, carvacrol, and oregano essential oil at all concentrations tested. No anti-staphylococcal activity was detected in Maqui extract. Finally, S. aureus is present in the pork chain supply in Chile. Although the mecA gene was not detected, oxacillin resistance was found in S. aureus and could be attributed to another resistance mechanism. Thymol, carvacrol, and oregano essential oil could be used as anti-staphylococcal agents at low concentrations. Research project Fondecyt No. 11140379.

Keywords: antimicrobials, mecA gen, nuc gen, oxacillin susceptibility, pork meat

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Authors: E. Nakamachi, K. Matsumoto, K. Yamamoto, Y. Morita, H. Sakamoto

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In recently, electromagnetic and mechanical stimulations have been recognized as the effective extracellular environment stimulation technique to enhance the defected peripheral nerve tissue regeneration. In this study, we developed a new hybrid bioreactor by adopting 50 Hz uniform alternative current (AC) magnetic stimulation and 4% strain mechanical stimulation. The guide tube for nerve regeneration is mesh structured tube made of biodegradable polymer, such as polylatic acid (PLA). However, when neural damage is large, there is a possibility that peripheral nerve undergoes necrosis. So it is quite important to accelerate the nerve tissue regeneration by achieving enhancement of nerve axonal extension rate. Therefore, we try to design and fabricate the system that can simultaneously load the uniform AC magnetic field stimulation and the stretch stimulation to cells for enhancement of nerve axonal extension. Next, we evaluated systems performance and the effectiveness of each stimulation for rat adrenal pheochromocytoma cells (PC12). First, we designed and fabricated the uniform AC magnetic field system and the stretch stimulation system. For the AC magnetic stimulation system, we focused on the use of pole piece structure to carry out in-situ microscopic observation. We designed an optimum pole piece structure using the magnetic field finite element analyses and the response surface methodology. We fabricated the uniform AC magnetic field stimulation system as a bio-reactor by adopting analytically determined design specifications. We measured magnetic flux density that is generated by the uniform AC magnetic field stimulation system. We confirmed that measurement values show good agreement with analytical results, where the uniform magnetic field was observed. Second, we fabricated the cyclic stretch stimulation device under the conditions of particular strains, where the chamber was made of polyoxymethylene (POM). We measured strains in the PC12 cell culture region to confirm the uniform strain. We found slightly different values from the target strain. Finally, we concluded that these differences were allowable in this mechanical stimulation system. We evaluated the effectiveness of each stimulation to enhance the nerve axonal extension using PC12. We confirmed that the average axonal extension length of PC12 under the uniform AC magnetic stimulation was increased by 16 % at 96 h in our bio-reactor. We could not confirm that the axonal extension enhancement under the stretch stimulation condition, where we found the exfoliating of cells. Further, the hybrid stimulation enhanced the axonal extension. Because the magnetic stimulation inhibits the exfoliating of cells. Finally, we concluded that the enhancement of PC12 axonal extension is due to the magnetic stimulation rather than the mechanical stimulation. Finally, we confirmed that the effectiveness of the uniform AC magnetic field stimulation for the nerve axonal extension using PC12 cells.

Keywords: nerve cell PC12, axonal extension, nerve regeneration, electromagnetic-mechanical stimulation, bioreactor

Procedia PDF Downloads 263

Authors: Rohin Rameswarapu, Sameer Valsangkar

Abstract:

Background: Globally, musculoskeletal disorders are the largest single cause of work-related illnesses accounting for over 33% of all newly reported occupational illnesses. Risk factors for MSD need to be delineated to suggest means for amelioration. Material and methods: In this current cross-sectional study, the prevalence of MSDs among workers in an electrical company assembly line, the socio-demographic and job characteristics associated with MSD were obtained through a semi-structured questionnaire. A quantitative assessment of the physical risk factors through the Rapid Upper Limb Assessment (RULA) tool, and measurement of psychosocial risk factors through a Likert scale was obtained. Statistical analysis was conducted using Epi-info software and descriptive and inferential statistics including chi-square and unpaired t test were obtained. Results: A total of 263 workers consented and participated in the study. Among these workers, 200 (76%) suffered from MSD. Most of the workers were aged between 18–27 years and majority of the workers were women with 198 (75.2%) of the 263 workers being women. A chi square test was significant for association between male gender and MSD with a P value of 0.007. Among the MSD positive group, 4 (2%) had a grand score of 5, 10 (5%) had a grand score of 6 and 186 (93%) had a grand score of 7 on RULA. There were significant differences between the non-MSD and MSD group on five out of the seven psychosocial domains, namely job demand, job monotony, co-worker support, decision control and family and environment domains. Discussion: The current cross-sectional study demonstrates a high prevalence of MSD among assembly line works with inherent physical and psychosocial risk factors and recommends that not only physical risk factors, addressing psychosocial risk factors through proper ergonomic means is also essential to the well-being of the employee.

Keywords: musculoskeletal disorders, India, occupational health, Rapid Upper Limb Assessment (RULA)

Procedia PDF Downloads 345

Authors: Sara D. Garduno-Diaz, Ramona Milcheva, Chanyu Xu

Abstract:

Women’s reproductive stages (pre-pregnancy, pregnancy, and lactation) represent a time of higher micronutrient needs. With a healthy food selection as the first path of choice to cover these increased needs, tandem micronutrient supplementation is often required. Because pregnancy and lactation should be treated with care, all supplements consumed should be of quality ingredients and manufactured through controlled processes. This work describes the process followed for the development of plant-based multiple micronutrient supplements aimed at addressing the growing demand for natural ingredients of non-animal origin. A list of key nutrients for inclusion was prioritized, followed by the identification and selection of qualified raw ingredient providers. Nutrient absorption into the food matrix was carried out through natural processes. The outcome is a new line of products meeting the set criteria of being gluten and lactose-free, suitable for vegans/vegetarians, and without artificial conservatives. In addition, each product provides the consumer with 10 vitamins, 6 inorganic nutrients, 1 source of essential fatty acids, and 1 source of phytonutrients each (maca, moringa, and chlorella). Each raw material, as well as the final product, was submitted to microbiological control three-fold (in-house and external). The final micronutrient mix was then tested for human factor contamination, pesticides, total aerobic microbial count, total yeast count, and total mold count. The product was created with the aim of meeting product standards for the European Union, as well as specific requirements for the German market in the food and pharma fields. The results presented here reach the point of introduction of the newly developed product to the market, with acceptability and effectiveness results to be published at a later date.

Keywords: fertility, lactation, organic, pregnancy, vegetarian

Procedia PDF Downloads 145

Authors: Vibha Venkataramu, B. V. Venkatarama Reddy

Abstract:

Natural river sand is the most preferred choice as fine aggregate in masonry mortars. Uncontrolled mining of sand from riverbeds for several decades has had detrimental effects on the environment. Several countries across the world have put strict restrictions on sand mining from riverbeds. However, in countries like India, the huge infrastructural boom has made the local construction industry to look for alternative materials to sand. This study aims at understanding the suitability of granulated blast furnace slag (GBS) as fine aggregates in masonry mortars. Apart from characterising the material properties of GBS, such as particle size distribution, pH, chemical composition, etc., of GBS, tests were performed on the mortars with GBS as fine aggregate. Additionally, the properties of five brick tall, stack bonded masonry prisms with various types of GBS mortars were studied. The mortars with mix proportions 1: 0: 6 (cement: lime: fine aggregate), 1: 1: 6, and 1: 0: 3 were considered for the study. Fresh and hardened properties of mortar, such as flow and compressive strength, were studied. To understand the behaviour of GBS mortars on masonry, tests such as compressive strength and flexure bond strength were performed on masonry prisms made with a different type of GBS mortars. Furthermore, the elastic properties of masonry with GBS mortars were also studied under compression. For comparison purposes, the properties of corresponding control mortars with natural sand as fine aggregate and masonry prisms with sand mortars were also studied under similar testing conditions. From the study, it was observed the addition of GBS negatively influenced the flow of mortars and positively influenced the compressive strength. The GBS mortars showed 20 to 25 % higher compressive strength at 28 days of age, compared to corresponding control mortars. Furthermore, masonry made with GBS mortars showed nearly 10 % higher compressive strengths compared to control specimens. But, the impact of GBS on the flexural strength of masonry was marginal.

Keywords: building materials, fine aggregate, granulated blast furnace slag in mortars, masonry properties

Procedia PDF Downloads 119

Authors: Noor Abdelhamid

Abstract:

Almost half of Cairo’s growing population is housed in self-built, self-governed informal settlements serving as an alternative in the absence of government-provided public housing. These settlements emerged as the spatial expression of informal practices or activities operating outside regulated, formal frameworks. A comprehensive narrative of political events, administrative decisions, and urban policies set the stage for the growth of informal expression in Egypt. The purpose of this qualitative inquiry is to portray informal self-governance practiced by residents in the Cairo region. This research argues that informal spatial practices offer an alternative urban framework for bottom-up development in the absence of government provisions. In the context of this study, informal self-governance is defined as the residents’ autonomous control and use of public urban space in informal settlements. The case study for this research is Ard al-Liwa, a semi-formal settlement representing the majority of informal settlement typologies in Egypt, which consist of the formal occupation of land through an uncontrolled land subdivision, zoning, and construction. An inductive methodological approach is adopted to first study informal practices as singular activities and then as components of a larger environment. The collected set of empirical data consists of audiovisual material and observations obtained during regular site visits and interviews with residents native to the settlement. Methods of analysis are synthesized to identify themes in the data: the static and dynamic use of sidewalks, the urban traces of informal building allocation and construction, the de facto right to urban space, and the resultant spatial patterns. The paper concludes by positioning the research in the context of the current architectural practice, questioning the role, and responsibility, of designers in these self-governed urban regions.

Keywords: Egypt, informal settlements, self-governance, urban framework

Procedia PDF Downloads 154

Authors: Benbelkacem Ouerdia

Abstract:

Heterotrophic denitrification has been proven to be one of the most feasible processes for removing nitrate from wastewater and drinking water. In this process, heterotrophic bacteria use organic carbon for both growth and as an electron source. Underground water pollution by nitrates become alarming in Algeria. A survey carried out revealed that the nitrate concentration is in continual increase. Studies in some region revealed contamination exceeding the recommended permissible dose which is 50 mg/L. Worrying values in the regions of Mascara, Ouled saber, El Eulma, Bouira and Algiers are respectively 72 mg/L, 75 mg/L, 97 mg/L, 102 mg/L, and 158 mg/L. High concentration of nitrate in drinking water is associated with serious health risks. Research on nitrate removal technologies from municipal water supplies is increasing because of nitrate contamination. Biological denitrification enables the transformation of oxidized nitrogen compounds by a wide spectrum of heterotrophic bacteria into harmless nitrogen gas with accompanying carbon removal. Globally, denitrification is commonly employed in biological nitrogen removal processes to enhance water quality The study investigated the valorization of a vegetable residue as a carbon source (dates nodes) in water treatment using the denitrification process. Throughout the study, the effect of inoculums addition, pH, and initial concentration of nitrates was also investigated. In this research, a natural organic substance: dates nodes were investigated as a carbon source in the biological denitrification of drinking water. This material acts as a solid substrate and bio-film carrier. The experiments were carried out in batch processes. Complete denitrification was achieved varied between 80 and 100% according to the type of process used. It was found that the nitrate removal rate based on our results, we concluded that the removal of organic matter and nitrogen compounds depended mainly on the initial concentration of nitrate. The effluent pH was mainly affected by the C/N ratio, where a decrease increases pH.

Keywords: biofilm, carbon source, dates nodes, heterotrophic denitrification, nitrate, nitrite

Procedia PDF Downloads 479

Authors: Zafar Iqbal Bhatti

Abstract:

The present research aims to examine and evaluate the frequencies and practices of verb complementation patterns in English newspaper social columns published in Pakistan and Britain. The research will demonstrate that Pakistani English is a non-native variety of English having its own unique usual and logical characteristics, affected by way of the native languages and the culture, upon syntactic levels, making the variety users aware that any differences from British or American English that are systematic and regular, or another English language, are not even if they are unique, erroneous forms and typical characteristics of several kinds. The objectives are to examine the verb complementation patterns that British and Pakistani social columnists use in relation to their syntactic categories. Secondly, to compare the verb complementation patterns used in Pakistani and British English newspapers social columns. This study will figure out various verb complementation patterns in Pakistani and British English newspaper social columns and their occurrence and distribution. The word classes express different functions of words, such as action, event, or state of being. This research aims to evaluate whether there are any appreciable differences in the verb complementation patterns used in Pakistani and British English newspaper social columns. The results will show the number of varieties of verb complementation patterns in selected English newspapers social columns. This study will fill the gap of previous studies conducted in this field as they only explore a little about the differences between Pakistani and British English newspapers. It will also figure out a variety of languages used in Pakistani and British English journals, as well as regional and cultural values and variations. The researcher will use AntConc software in this study to extract the data for analysis. The researcher will use a concordance tool to identify verb complementation patterns in selected data. Then the researcher will manually categorize them because the same type of adverb can sometimes be used for various purposes. From 1st June 2022 to 30th Sep. 2022, a four-month written corpus of the social columns of PE and BE newspapers will be collected and analyzed. For the analysis of the research questions, 50 social columns will be selected from Pakistani newspapers and 50 from British newspapers. The researcher will collect a representative sample of data from Pakistani and British English newspaper social columns. The researcher will manually analyze the complementation patterns of each verb in each sentence, and then the researcher will determine how frequently each pattern occurs. The researcher will use syntactic characteristics of the verb complementation elements according to the description by Downing and Locke (2006). The researcher will examine all of the verb complementation patterns in the data, and the frequency and distribution of each verb complementation pattern will be evaluated using the software. The researcher will explore every possible verb complementation pattern in Pakistani and British English before calculating the occurrence and abundance of each verb pattern. The researcher will explore every possible verb complementation pattern in Pakistani English before calculating the frequency and distribution of each pattern.

Keywords: verb complementation, syntactic categories, newspaper social columns, corpus

Procedia PDF Downloads 41

Authors: Tania Lisboa, Angela Voyajolu, Adam Ockelford

Abstract:

The positive impact of music on the development of children with autism is widely acknowledged: music offers a unique channel for communication, wellbeing and self-regulation, as well as access to culture and a means of creative engagement. Yet, no coherent program exists for parents, carers and teachers to follow with their children in the early years, when the need for interventions is often most acute. Hence, research and the development of resources is urgently required. Autism is a project with children on the autism spectrum. The project aims at promoting the participants’ engagement with music through involvement in specially-designed musical activities with parents and carers. The main goal of the research is to verify the effectiveness of newly designed resources and strategies, which are based on the Sounds of Intent in the Early Years (SoI-EY) framework of musical development. This is a pilot study, comprising case studies of five children with autism in the early years. The data comprises semi-structured interviews, observations of videos, and feedback from parents on resources. Interpretative Phenomenological Analysis was chosen to analyze the interviews. The video data was coded in relation to the SoI-EY framework. The feedback from parents was used to evaluate the resources (i.e. musical activity cards). The participants’ wider development was also assessed through selected elements of the Early Years Foundation Stage (EYFS), a national assessment framework used in England: specifically, communication, language and social-emotional development. Five families of children on the autism spectrum (aged between 4-8 years) participated in the pilot. The research team visited each family 4 times over a 3-month period, during which the children were observed, and musical activities were suggested based on the child’s assessed level of musical development. Parents then trialed the activities, providing feedback and gathering further video observations of their child’s musical engagement between visits. The results of one case study will be featured in this paper, in which the evidence suggests that specifically tailored musical activity may promote communication and social engagement for a child with language difficulties on the autism spectrum. The resources were appropriate for the children’s involvement in musical activities. Findings suggest that non-specialist musical engagement with family and carers can be a powerful means to foster communication. The case study featured in this paper illustrates this with a child of limited verbal ability. There is a need for further research and development of resources that can be made available to all those working with children on the autism spectrum.

Keywords: autism, development, music education, resources

Procedia PDF Downloads 100

Authors: Sarekha Woranuch, Rangrong Yoksan

Abstract:

Chitosan is a derivative of chitin, which is a second most naturally abundant polysaccharide found in crab shells, shrimp shells, and squid pens. The applications of chitosan in pharmaceutical, cosmetics, food and packaging industries have been reported owing to its general recognition as safe, excellent biodegradability and biocompatibility, as well as ability to form films, membranes, gels, beads, fibers and particles. Nevertheless, chitosan is an amino polysaccharide consisting of strong inter- and intramolecular hydrogen bonds which limit its solubility in neutral pH water resulting in restricted utilization. Chemical modification is an alternative way to impede hydrogen bond formation. The objective of the present research is to improve water solubility and antioxidant activity of chitosan by grafting with ferulic acid. Ferulic acid was grafted onto chitosan at the C-2 position via a carbodiimide-mediated coupling reaction. Different mole ratios of chitosan to ferulic acid (i.e. 1.0:0.0, 1.0:0.5, 1.0:1.0, 1.0:1.5, 1.0:2.0, and 1.0:2.5) and various reaction temperatures (i.e. 40, 60, and 80 °C) were used. The reaction was performed at different times (i.e. 1.5, 3.0, 4.5, and 6.0 h). The obtained ferulic acid-grafted chitosan was characterized by FTIR and 1H NMR technique. The influences of ferulic acid on crystallinity, solubility and radical scavenging activity of chitosan were also investigated. Ferulic acid grafted chitosan was successfully synthesized as confirmed from (i) the appearance of FTIR absorption band at 1517 cm-1 belonging to C=C aromatic ring of ferulic acid and the increased C–H stretching band intensity and (ii) the appearance of proton signals at δ = 6.31-7.67 ppm ascribing to methine protons of ferulic acid. The condition in which the reaction temperature of 60°C, reaction time of 3 h and the mole ratio of chitosan to ferulic acid of 1:1 gave the highest ferulic acid substitution degree, i.e. 0.37. The resulting ferulic acid grafted chitosan was soluble in water (1.3 mg/mL) due to its reduced crystallinity as compared with chitosan and also exhibited 90% greater radical scavenging activity than chitosan. The result suggested the utilization of ferulic acid grafted chitosan as an antioxidant material.

Keywords: antioxidant property, chitosan, ferulic acid, grafting

Procedia PDF Downloads 455

Authors: Jose Melena, Rosa Santander, Tanya Gonzalez, Richard Duque, Juan Illanes

Abstract:

Ecuador is one of the countries with the greatest aquatic biodiversity worldwide. In particular, there are at least a dozen native marine species with great aquaculture potential locally. This research concerns one of those species. It has proposed to implement experimental protocols in order to induce spawning and to generate the early larval development of the giant reef clam P. multicostata under controlled conditions. Bioassays were carried out with one adult batch (n= 8) with an average valvar length of 118,4 ± 5,8 mm, which were collected near of the Puerto Santa Rosa (2° 12' 30'' S, 80° 58' 28'' W), Santa Elena Province. During a short acclimation stage, the eight adults of giant reef clam P. multicostata were exposed to thermal stress. Briefly, the experimental protocol for spawning induction was based on the application of 20°C for 1 h and 30°C for 1 h on P. multicostata broodstock at least three consecutive times by one day. After spawning, collected sexual material was released for external fertilization process. After the delivery of gametes, it was achieved 3,25 × 10⁶ viable zygotes. As results, fertilized eggs had 56 µm diameter; while first and second cell divisions were observed to 2,5 h post-fertilization, with individual average length of 68 ± 5 µm and polar body. Latter cell divisions, including gastrula stage, appeared at 9 h post-fertilization, with individual average length of 73 ± 4 µm and trochophore stage at 15 h post-fertilization with individual average length of 75 ± 4 µm. In addition, veliger stage was registered at 20 h post-fertilization with individual average length of 82 ± 6 µm. Umboned larvae appeared at day 8 post-fertilization, with individual average length of 148 ± 6 µm. These pioneering results worldwide can strengthen the local conservation process of the overexploited P. multicostata and to encourage its production for commercial purposes.

Keywords: Ecuador, larval development, Periglypta multicostata, spawning induction

Procedia PDF Downloads 131

Authors: Shubham Sharma, Sandra Barkauskaite, Brendan Duffy, Swarna Jaiswal, Amit K. Jaiswal

Abstract:

Food packaging protects food from temperature, light, and humidity; preserves food and guarantees the safety and the integrity of the food. Advancement in packaging research leads to development of active packaging system with numerous properties such as oxygen scavengers, carbon-dioxide generating systems, antimicrobial active packaging, moisture control packaging, ethylene scavengers etc. In the active packaging, several additives such as essential oils, polyphenols etc. are incorporated into packaging film or within the packaging material to achieve the desired properties. This study investigates the effect on the structural, thermal and functional properties of different poly(lactide) – poly (butylene adipate-co-terephthalate) (PLA-PBAT) blend films incorporated with clove essential oil. The PLA-PBAT films were prepared by a solution casting method and then characterized based on their optical, mechanical properties, surface hydrophobicity, chemical composition, antimicrobial activity against S. aureus and E. coli, and inhibition of biofilm formation of E. coli. Results showed that, the developed packaging film containing clove oil has significant UV-blocking property (80%). However, incorporation of clove oil resulted in reduced transparency and tensile strength of the film as the concentration of clove oil increased. The surface hydrophobicity of packaging film was improved with the increasing concentration of essential oil. Similarly, thickness of the clove oil containing films increased from 36.71 µm to 106.67 µm as the concentration increases. The antimicrobial activity and biofilm inhibition study showed that the clove-incorporated PLA-PBAT composite film was effective against tested bacteria E. coli and S. aureus. This study showed that the PLA-PBAT – Clove oil composite film has significant antimicrobial and UV-blocking properties and can be used as an active food packaging film.

Keywords: active packaging, clove oil, poly(butylene adipate-co-terephthalate), poly(lactide)

Procedia PDF Downloads 146

Authors: Mark Kaahwa, Chang Zhu, Moses Muhumuza

Abstract:

This study investigates the satisfaction of distance education university students (DEUS) with the use of audio media as a medium of instruction. Studying students’ satisfaction is vital because it shows whether learners are comfortable with a certain instructional strategy or not. Although previous studies have investigated the use of audio media, the satisfaction of students with an instructional strategy that combines radio teaching and podcasts as an independent teaching strategy has not been fully investigated. In this study, all lectures were delivered through the radio and students had no direct contact with their instructors. No modules or any other material in form of text were given to the students. They instead, revised the taught content by listening to podcasts saved on their mobile electronic gadgets. Prior to data collection, DEUS received orientation through workshops on how to use audio media in distance education. To achieve objectives of the study, a survey, naturalistic observations and face-to-face interviews were used to collect data from a sample of 211 undergraduate and graduate students. Findings indicate that there was no statistically significant difference in the levels of satisfaction between male and female students. The results from post hoc analysis show that there is a statistically significant difference in the levels of satisfaction regarding the use of audio media between diploma and graduate students. Diploma students are more satisfied compared to their graduate counterparts. T-test results reveal that there was no statistically significant difference in the general satisfaction with audio media between rural and urban-based students. And ANOVA results indicate that there is no statistically significant difference in the levels of satisfaction with the use of audio media across age groups. Furthermore, results from observations and interviews reveal that DEUS found learning using audio media a pleasurable medium of instruction. This is an indication that audio media can be considered as an instructional strategy on its own merit.

Keywords: audio media, distance education, distance education university students, medium of instruction, satisfaction

Procedia PDF Downloads 113

Authors: Mengdi Zhang, Xufeng Liu, Zhenji Gao, Ying Li, Zhu Rao, Yi Huang

Abstract:

As an open system, the earth is constantly undergoing the transformation and release of matter and energy. Fault zones are relatively discontinuous and fragile geological structures, and the release of material and energy inside the Earth is strongest in relatively weak fault zones. Earthquake events frequently occur in fault zones and are closely related to tectonic activity in these zones. In earthquake precursor observation, monitoring the spatiotemporal changes in the release of related gases near fault zones (such as radon gas, hydrogen, carbon dioxide, helium), and analyzing earthquake precursor anomalies, can be effective means to forecast the occurrence of earthquake events. Radon gas, as an inert radioactive gas generated during the decay of uranium and thorium, is not only a indicator for monitoring tectonic and seismic activity, but also an important topic for ecological and environmental health, playing a crucial role in uranium exploration. At present, research on soil radon gas mainly focuses on the measurement of soil gas concentration and flux in fault zone profiles, while research on the correlation between spatiotemporal concentration changes in the same region and its geological background is relatively little. In this paper, Tangshan area in north China is chosen as research area. An analysis was conducted on the seismic geological background of Tangshan area firstly. Then based on quantitative analysis and comparison of measurement radon concentrations of 2023 and 2010, combined with the study of seismic activity and environmental changes during the time period, the spatiotemporal distribution characteristics and influencing factors were explored, in order to analyze the gas emission characteristics of the Tangshan fault zone and its relationship with fault activity, which aimed to be useful for the future work in earthquake monitor of Tangshan area.

Keywords: radon, Northern China, soil gas, earthquake

Procedia PDF Downloads 76

Authors: Ouerdia Benbelkacem Belouanas

Abstract:

Heterotrophic denitrification has been proven to be one of the most feasible processes for removing nitrate from waste water and drinking water. In this process, heterotrophic bacteria use organic carbon for both growth and as an electron source. Underground water pollution by nitrates become alarming in Algeria. A survey carried out revealed that the nitrate concentration is in continual increase. Studies in some region revealed contamination exceeding the recommended permissible dose which is 50 mg/L. Worrying values in the regions of Mascara, Ouled saber, El Eulma, Bouira and Algiers are respectively 72 mg/L, 75 mg/L, 97 mg/L, 102 mg/L, and 158 mg/L. High concentration of nitrate in drinking water is associated with serious health risks. Research on nitrate removal technologies from municipal water supplies is increasing because of nitrate contamination. Biological denitrification enables transformation of oxidized nitrogen compounds by a wide spectrum of heterotrophic bacteria into harmless nitrogen gas with accompanying carbon removal. Globally, denitrification is commonly employed in biological nitrogen removal processes to enhance water quality. The study investigated the valorization of a vegetable residue as a carbon source (dates nodes) in water treatment using the denitrification process. Throughout the study, the effect of inoculums addition, pH, and initial concentration of nitrates was also investigated. In this research, a natural organic substance: dates nodes were investigated as a carbon source in the biological denitrification of drinking water. This material acts as a solid substrate and bio-film carrier. The experiments were carried out in batch processes. Complete denitrification was achieved varied between 80 and 100% according to the type of process used. It was found that the nitrate removal rate based on our results, we concluded that the removal of organic matter and nitrogen compounds depended mainly on initial concentration of nitrate. The effluent pH was mainly affected by the C/N ratio, where a decrease increases pH.

Keywords: biofilm, carbon source, dates nodes, heterotrophic denitrification, nitrate, nitrite

Procedia PDF Downloads 411