Search results for: stress concentration factor

Authors: Rose Mini Agoes Salim, Shahnaz Safitri

Abstract:

The aim of this study is to test the effectiveness of teaching kindness in preschool children by using several techniques. Kindness is a physical act or emotional support aimed to build or maintain relationships with others. Kindness is known to be essential in the development of moral reasoning to distinguish between the good and bad things. In this study, kindness is operationalized as several acts including helping friends, comforting sad friends, inviting friends to play, protecting others, sharing, saying hello, saying thank you, encouraging others, and apologizing. It is mentioned that kindness is crucial to be developed in preschool children because this is the time the children begin to interact with their social environment through play. Furthermore, preschool children's cognitive development makes them begin to represent the world with words, which then allows them to interact with others. On the other hand, preschool children egocentric thinking makes them still need to learn to consider another person's perspective. In relation to social interaction, preschool children need to be stimulated and assisted by adult to be able to pay attention to other and act with kindness toward them. On teaching kindness to children, the quality of interaction between children and their significant others is the key factor. It is known that preschool children learn about kindness by imitating adults on their two way interaction. Specifically, this study examines two types of teaching techniques that can be done by parents as a way to teach kindness, namely the picture-storybook reading and hand-puppet storytelling. These techniques were examined because both activities are easy to do and both also provide a model of behavior for the child based on the character in the story. To specifically examine those techniques effectiveness in teaching kindness, two studies were conducted. Study I involves 31 children aged 5-6 years old with picture-storybook reading technique, where the intervention is done by reading 8 picture books for 8 days. In study II, hand-puppet storytelling technique is examined to 32 children aged 3-5 years old. The treatments effectiveness are measured using an instrument in the form of nine colored cards that describe the behavior of kindness. Data analysis using Wilcoxon Signed-rank test shows a significant difference on the average score of kindness (p < 0.05) before and after the intervention has been held. For daily observation, a ‘kindness tree’ and observation sheets are used which are filled out by the teacher. Two weeks after interventions, an improvement on all kindness behaviors measured is intact. The same result is also gained from both ‘kindness tree’ and observational sheets.

Keywords: kindness, moral teaching, storytelling, hand puppet

Procedia PDF Downloads 253

Authors: Nayeli Camacho, Fernanda Lara-Perez, Carolina Ortega-Portilla, Diego G. Espinosa-Arbelaez, Juan M. Alvarado-Orozco, Guillermo C. Mondragon-Rodriguez

Abstract:

Ultra-high molecular weight polyethylene (UHMWPE) has been the gold standard material for total knee replacements for almost five decades. Wear damage to UHMWPE articulating surface is inevitable due to the natural sliding and rolling movements of the knee. This generates a considerable amount of wear debris, which results in mechanical instability of the joint, reduces joint mobility, increases pain with detrimental biologic responses, and causes component loosening. The presence of wear particles has been closely related to adverse reactions in the knee joint surrounding tissue, especially for particles in the range of 0.3 to 2 μm. Carbon-based materials possess excellent mechanical properties and have shown great promise in tribological applications. In this study, diamond-like carbon coatings (DLC) and carbon nanotubes (CNTs) were used to decrease the wear rate of ultra-high molecular weight polyethylene. A titanium doped DLC (Ti-DLC) was deposited by magnetron sputtering on stainless steel precision spheres while CNTs were used as a second phase reinforcement in UHMWPE at a concentration of 1.25 wt.%. A comparative tribological analysis of the wear of UHMWPE and UHMWPE-CNTs with a stainless steel counterpart with and without Ti-DLC coating is presented. The experimental wear testing was performed on a pin-on-disc tribometer under dry conditions, using a reciprocating movement with a load of 1 N at a frequency of 2 Hz for 100,000 and 200,000 cycles. The wear tracks were analyzed with high-resolution scanning electron microscopy to determine wear modes and observe the size and shape of the wear debris. Furthermore, profilometry was used to study the depth of the wear tracks and to map the wear of the articulating surface. The wear tracks at 100,000 and 200,000 cycles on all samples were relatively shallow, and they were in the range of average roughness. It was observed that the Ti-DLC coating decreases the mass loss in the UHMWPE and the depth of the wear track. The combination of both carbon-based materials decreased the material loss compared to the system of stainless steel and UHMWPE. Burnishing of the surface was the predominant wear mode observed with all the systems, more subtle for the systems with Ti-DLC coatings. Meanwhile, in the system composed of stainless steel-UHMWPE, the intrinsic surface roughness of the material was completely replaced by the wear tracks.

Keywords: CNT reinforcement, self-lubricating materials, Ti-DLC, UHMWPE tribological performance

Procedia PDF Downloads 111

Authors: Siriwan Chatmaneerungcharoen

Abstract:

An emerging body of ‘21st century skills’-such as adaptability, complex communication skills, technology skills and the ability to solve non-routine problems--are valuable across a wide range of jobs in the national economy. Within the Thai context, a focus on the Philosophy of Sufficiency Economy is integrated into Science Education. Thai science education has advocated infusing 21st century skills and Philosophy of Sufficiency Economy into the school curriculum and several educational levels have launched such efforts. Therefore, developing science teachers to have proper knowledge is the most important factor to success of the goals. The purposes of this study were to develop 40 Cooperative Science teachers’ Technological Pedagogical Content Knowledge (TPACK) and to develop Professional Development Model integrated with Co-teaching Model and Coaching System (Co-TPACK). TPACK is essential to career development for teachers. Forty volunteer In-service teachers who were science cooperative teachers participated in this study for 2 years. Data sources throughout the research project consisted of teacher refection, classroom observations, Semi-structure interviews, Situation interview, questionnaires and document analysis. Interpretivist framework was used to analyze the data. Findings indicate that at the beginning, the teachers understood only the meaning of Philosophy of Sufficiency Economy but they did not know how to integrate the Philosophy of Sufficiency Economy into their science classrooms. Mostly, they preferred to use lecture based teaching and experimental teaching styles. While the Co- TPACK was progressing, the teachers had blended their teaching styles and learning evaluation methods. Co-TPACK consists of 3 cycles (Student Teachers’ Preparation Cycle, Cooperative Science Teachers Cycle, Collaboration cycle (Co-teaching, Co-planning, and Co-Evaluating and Coaching System)).The Co-TPACK enhances the 40 cooperative science teachers, student teachers and university supervisor to exchange their knowledge and experience on teaching science. There are many channels that they used for communication including online. They have used more Phuket context-integrated lessons, technology-integrated teaching and Learning that can explicit Philosophy of Sufficiency Economy. Their sustained development is shown in their lesson plans and teaching practices.

Keywords: technological pedagogical content knowledge, philosophy of sufficiency economy, professional development, coaching system

Procedia PDF Downloads 469

Authors: M. Aboalazayem, Essam A. Gouda, Ahmed M. Moussa, Amr E. Flifl

Abstract:

Field data collecting is considered one of the most difficult work due to the difficulty of accessing large zones such as large lakes. Also, it is well known that the cost of obtaining field data is very expensive. Remotely monitoring of lake water quality (WQ) provides an economically feasible approach comparing to field data collection. Researchers have shown that lake WQ can be properly monitored via Remote sensing (RS) analyses. Using satellite images as a method of WQ detection provides a realistic technique to measure quality parameters across huge areas. Landsat (LS) data provides full free access to often occurring and repeating satellite photos. This enables researchers to undertake large-scale temporal comparisons of parameters related to lake WQ. Satellite measurements have been extensively utilized to develop algorithms for predicting critical water quality parameters (WQPs). The goal of this paper is to use RS to derive WQ indicators in Aswan High Dam Reservoir (AHDR), which is considered Egypt's primary and strategic reservoir of freshwater. This study focuses on using Landsat8 (L-8) band surface reflectance (SR) observations to predict water-quality characteristics which are limited to Turbidity (TUR), total suspended solids (TSS), and chlorophyll-a (Chl-a). ArcGIS pro is used to retrieve L-8 SR data for the study region. Multiple linear regression analysis was used to derive new correlations between observed optical water-quality indicators in April and L-8 SR which were atmospherically corrected by values of various bands, band ratios, and or combinations. Field measurements taken in the month of May were used to validate WQP obtained from SR data of L-8 Operational Land Imager (OLI) satellite. The findings demonstrate a strong correlation between indicators of WQ and L-8 .For TUR, the best validation correlation with OLI SR bands blue, green, and red, were derived with high values of Coefficient of correlation (R2) and Root Mean Square Error (RMSE) equal 0.96 and 3.1 NTU, respectively. For TSS, Two equations were strongly correlated and verified with band ratios and combinations. A logarithm of the ratio of blue and green SR was determined to be the best performing model with values of R2 and RMSE equal to 0.9861 and 1.84 mg/l, respectively. For Chl-a, eight methods were presented for calculating its value within the study area. A mix of blue, red, shortwave infrared 1(SWR1) and panchromatic SR yielded the greatest validation results with values of R2 and RMSE equal 0.98 and 1.4 mg/l, respectively.

Keywords: remote sensing, landsat 8, nasser lake, water quality

Procedia PDF Downloads 93

Authors: Carolina Gutierrez-Cortes, Hector Suarez, Gustavo Buitrago

Abstract:

Bacteriocins are antimicrobial peptides produced by bacteria as a competitive strategy for substrate and habitat. Those peptides have a potential use as food biopreservatives due to their antimicrobial activity against foodborne pathogens, avoiding the use of additives that can be harmful to consumers. The industrial production of bacteriocins is currently expensive; one of the options to be competitive is the development of economic culture media, for example, with the use of agro-industrial wastes such as whey. This study evaluated the growth and production of bacteriocins from four strains: Pediococcus pentosaceus 63, Pediococcus pentosaceus 145, Pediococcus pentosaceus 146 and Pediococcus pentosaceus 147 isolated from ‘minas cheese’ (artisanal cheese made from raw milk in the state of Minas Gerais, Brazil) in order to select a strain with growth at high rates and higher antimicrobial activity against Listeria monocytogenes 104 after incubation on the culture medium designed with whey and other components. The media used were: MRS broth, modified MRS broth (using different sources of carbon and nitrogen and different amounts of micronutrients) and a culture medium designed by a factorial design using whey and other components. The final biomass concentrations of the four strains in MRS broth after 24 hours of incubation were very similar 9.25, 9.33, 9.25 and 9.22 (log CFU/mL) for P. pentosaceus 63, P. pentosaceus 145, P. pentosaceus 146 and P. pentosaceus 147 respectively. In the same assays, antimicrobial activity of 3200 AU/mL for the first three and of 12800 AU/mL for P. pentosaceus 147 were obtained. Culture of P. pentosaceus 63 on modified MRS broth, showed the effect of some sources of carbon on the activity of bacteriocin, obtaining 12800 AU/mL with dextrose and 25600 AU/mL with maltose. Cultures of P. pentosaceus 145, 146 and 147 with these same sugars presented activity of 12800 AU/mL. It was observed that the modified MRS medium using whey increased the antimicrobial activity of the strains at 16000, 6400, 16000 and 19200 AU/mL for each strain respectively, keeping the biomass at values close to 9 log units. About nitrogen sources, it was observed that the combination of peptone (10 g /L), meat extract (10 g/L) and yeast extract (5 g/L) promoted the highest activity (12800 AU/mL), and in all cases MgSO4, MnSO4, K2HPO4 and ammonium citrate at low concentrations adversely affected bacteriocin production. Because P. pentosaceus 147 showed the highest antimicrobial activity in the presence of whey, it was used to evaluate the culture medium (peptone (10 g/L), meat extract (8 g/L), yeast extract (2 g/L), Tween® 80 (1 g/L), ammonium citrate (2 g/L), sodium acetate (5 g/L), MgSO4 (0.2 g/L), MnSO4 (0.04 g/L)). With the designed medium added with whey, 9.34 log units of biomass concentration and 19200 AU/mL were achieved for P. pentosaceus 147. The above suggest that the new medium promotes the antimicrobial activity of P. pentosaceus 147 allowing the use of an economic medium using whey.

Keywords: antimicrobial activity, bacteriocins, pediococcus, whey

Procedia PDF Downloads 227

Authors: Bamikole J. Adeyemi, Prashant Jadhawar, Lateef Akanji

Abstract:

Liquid-liquid interfacial flow is an important process that has applications across many spheres. One such applications are residual oil mobilization, where crude oil and low salinity water are emulsified due to lowered interfacial tension under the condition of low shear rates. The amphiphilic components (asphaltenes and resins) in crude oil are considered to assemble at the interface between the two immiscible liquids. To justify emulsification, drag and snap-off suppression as the main effects of low salinity water, mobilization of residual oil is visualized as thickening and slip of the wetting phase at the brine/crude oil interface which results in the squeezing and drag of the non-wetting phase to the pressure sinks. Meanwhile, defining the boundary conditions for such a system can be very challenging since the interfacial dynamics do not only depend on interfacial tension but also the flow rate. Hence, understanding the flow boundary condition at the brine/crude oil interface is an important step towards defining the influence of low salinity water composition on residual oil mobilization. This work presents a numerical evaluation of three slip boundary conditions that may apply at liquid-liquid interfaces. A mathematical model was developed to describe the evolution of a viscoelastic interfacial thin liquid film. The base model is developed by the asymptotic expansion of the full Navier-Stokes equations for fluid motion due to gradients of surface tension. This model was upscaled to describe the dynamics of the film surface deformation. Subsequently, Jeffrey’s model was integrated into the formulations to account for viscoelastic stress within a long wave approximation of the Navier-Stokes equations. To study the fluid response to a prescribed disturbance, a linear stability analysis (LSA) was performed. The dispersion relation and the corresponding characteristic equation for the growth rate were obtained. Three slip (slip, 1; locking, -1; and no-slip, 0) boundary conditions were examined using the resulted characteristic equation. Also, the dynamics of the evolved interfacial thin liquid film were numerically evaluated by considering the influence of the boundary conditions. The linear stability analysis shows that the boundary conditions of such systems are greatly impacted by the presence of amphiphilic molecules when three different values of interfacial tension were tested. The results for slip and locking conditions are consistent with the fundamental solution representation of the diffusion equation where there is film decay. The interfacial films at both boundary conditions respond to exposure time in a similar manner with increasing growth rate which resulted in the formation of more droplets with time. Contrarily, no-slip boundary condition yielded an unbounded growth and it is not affected by interfacial tension.

Keywords: boundary conditions, liquid-liquid interfaces, low salinity water, residual oil mobilization

Procedia PDF Downloads 130

Authors: Somnath Bhattacharya, Kamal Sharma, Vaibhav Sonkar

Abstract:

Composite materials emerged in the middle of the 20th century as a promising class of engineering materials providing new prospects for modern technology. Recently, a new class of composite materials known as functionally graded materials (FGMs) has drawn considerable attention of the scientific community. In general, FGMs are defined as composite materials in which the composition or microstructure or both are locally varied so that a certain variation of the local material properties is achieved. This gradual change in composition and microstructure of material is suitable to get gradient of properties and performances. FGMs are synthesized in such a way that they possess continuous spatial variations in volume fractions of their constituents to yield a predetermined composition. These variations lead to the formation of a non-homogeneous macrostructure with continuously varying mechanical and / or thermal properties in one or more than one direction. Lightweight functionally graded composites with high strength to weight and stiffness to weight ratios have been used successfully in aircraft industry and other engineering applications like in electronics industry and in thermal barrier coatings. In the present work, elastic-plastic crack growth problems (using Ramberg-Osgood Model) in an FGM plate under cyclic load has been explored by extended finite element method. Both edge and centre crack problems have been solved by taking additionally holes, inclusions and minor cracks under plane stress conditions. Both soft and hard inclusions have been implemented in the problems. The validity of linear elastic fracture mechanics theory is limited to the brittle materials. A rectangular plate of functionally graded material of length 100 mm and height 200 mm with 100% copper-nickel alloy on left side and 100% ceramic (alumina) on right side is considered in the problem. Exponential gradation in property is imparted in x-direction. A uniform traction of 100 MPa is applied to the top edge of the rectangular domain along y direction. In some problems, domain contains major crack along with minor cracks or / and holes or / and inclusions. Major crack is located the centre of the left edge or the centre of the domain. The discontinuities, such as minor cracks, holes, and inclusions are added either singly or in combination with each other. On the basis of this study, it is found that effect of minor crack in the domain’s failure crack length is minimum whereas soft inclusions have moderate effect and the effect of holes have maximum effect. It is observed that the crack growth is more before the failure in each case when hard inclusions are present in place of soft inclusions.

Keywords: elastic-plastic, fatigue crack, functionally graded materials, extended finite element method (XFEM)

Procedia PDF Downloads 390

Authors: Cemil Atakara, Hüseyin Eryaman

Abstract:

The use of glass as an envelope of a building has been increasing in the twentieth century. For more transparency and dematerialization new glass facade types have emerged in the past two decades which depends on point fixed glazing system (PFGS). The aim of this study is to analyze of the PFGS systems which are used on the glass curtain wall according to their types, degree, architectural and structural effects. This new system is desired because it enhances the transparency of the façade and it minimizes the component of the frames or of the profiles. This PFGS led to new structural elements which use cables, rods, trusses when designing a glass building facades, this structural element called the suspended glass system with pre-stressed cable truss (SGSPCT) which has been used for the first time in 1980 in Serres building. The twenty glass buildings which are designed in different systems have been analyzed during this study. After these analyses five selected SGSPCT building analyzed deeply and one skeletal frame building selected from Lefkosa redesigned according to the analysis results. These selected buildings have been included of various cable-truss system typologies and degree. The methodology of this study is building analysis method and literature survey with the help of books, articles, magazines, drawings, internet sources and applied connection details of the glass buildings. The selected five glass buildings and case building have been detailed analyzed with their architectural drawings, photographs and details. A gridshell structure can be compared with a shell structure; it consists of discrete members connecting nodal points. As these nodal points lie on the surface of an imaginary shell, their shapes function almost identically. Difference between shell and gridshell structures can be found in the fact that, due to their free-form and thus, due to the presence of bending forces, gridshells are required to resist loading through their cross-section. This research is divided into parts. A general study about the glass building and cable-glass and grid shell system will be done in the first chapters. Structural analyses and detailed analyses with schematic drawings with the plans, sections of the selected buildings will be explained in the second part. The third part it consists of the advantages and disadvantages of the use of the SGSPCT and Grid Shell in architecture. The study consists of four chapters including the introduction chapter. The general information of the SGSPCT and glazing system has been mentioned in the first chapter. Structural features, typologies, transparency principle and analytical information on systems have been explained of the selected buildings in the second chapter. The detailed analyses of case building have been done according to their schematic drawings with the plans, sections in the third chapter. After third chapter SGSPCT discussed on to the case building and selected buildings. SGSPCT systems have been compared with their advantages and disadvantages to the other systems. Advantages of cable-truss systems and SGSPCT have been concluded that the use of glass substrates in the last chapter.

Keywords: cable truss, glass, grid shell, transparency

Procedia PDF Downloads 412

Authors: A. Olivi, P. Reyes Cabrera

Abstract:

Ageing and urbanization are two of the main trends that characterize the twenty-first century. Its trending is especially accelerated in the emerging countries of Asia and Latin America. Chile is one of the countries in the Latin American region, where the demographic transition to ageing is becoming increasingly visible. The challenges that the new demographic scenario poses to urban administrators call for searching innovative solutions to maximize the functional and psycho-social benefits derived from the relationship between older people and the environment in which they live. Although mobility is central to people's everyday practices and social relationships, it is not distributed equitably. On the contrary, it can be considered another factor of inequality in our cities. Older people are a particularly sensitive and vulnerable group to mobility. In this context, based on the ageing in place strategy and following the social innovation approach within a spatial context, the "Community Observatory of Territorial Information Control and Management" project aims at the collective search and validation of solutions for the satisfaction of mobility and accessibility specific needs of urban aged people. Specifically, the Observatory intends to: i) promote the direct participation of the aged population in order to generate relevant information on the territorial situation and the satisfaction of the mobility needs of this group; ii) co-create dynamic and efficient mechanisms for the reporting and updating of territorial information; iii) increase the capacity of the local administration to plan and manage solutions to environmental problems at the neighborhood scale. Based on a participatory mapping methodology and on the application of digital technology, the Observatory designed and developed, together with aged people, a crowdsourcing platform for smartphones, called DIMEapp, for reporting environmental problems affecting mobility and accessibility. DIMEapp has been tested at a prototype level in two neighborhoods of the city of Valparaiso. The results achieved in the testing phase have shown high potential in order to i) contribute to establishing coordination mechanisms with the local government and the local community; ii) improve a local governance system that guides and regulates the allocation of goods and services destined to solve those problems.

Keywords: accessibility, ageing, city, digital technology, local governance

Procedia PDF Downloads 133

Authors: M. Gowri, E. K. Girija, V. Ganesh

Abstract:

Background and Significance: Among the dental infections, inflammation and infection of the root canal are common among all age groups. Currently, the management of root canal infections involves cleaning the canal with powerful irrigants followed by intracanal medicament application. Though these treatments have been in vogue for a long time, root canal failures do occur. Treatment for root canal infections is limited due to the anatomical complexity in terms of small micrometer volumes and poor penetration of drugs. Thus, infections of the root canal seem to be a challenge that demands development of new agents that can eradicate C. albicans. Methodology: In the present study, we synthesized and screened silver-curcumin nanoparticle against Candida albicans. Detailed molecular studies were carried out with silver-curcumin nanoparticle on C. albicans pathogenicity. Morphological cell damage and antibiofilm activity of silver-curcumin nanoparticle on C. albicans was studied using scanning electron microscopy (SEM). Biochemical evidence for membrane damage was studied using flow cytometry. Further, the antifungal activity of silver-curcumin nanoparticle was evaluated in an ex vivo dentinal tubule infection model. Results: Screening data showed that silver-curcumin nanoparticle was active against C. albicans. Silver-curcumin nanoparticle exerted time kill effect and post antifungal effect. When used in combination with fluconazole or nystatin, silver-curcumin nanoparticle revealed a minimum inhibitory concentration (MIC) decrease for both drugs used. In-depth molecular studies with silver-curcumin nanoparticle on C. albicans showed that silver-curcumin nanoparticle inhibited yeast to hyphae (Y-H) conversion. Further, SEM images of C. albicans showed that silver-curcumin nanoparticle caused membrane damage and inhibited biofilm formation. Biochemical evidence for membrane damage was confirmed by increased propidium iodide (PI) uptake in flow cytometry. Further, the antifungal activity of silver-curcumin nanoparticle was evaluated in an ex vivo dentinal tubule infection model, which mimics human tooth root canal infection. Confocal laser scanning microscopy studies showed eradication of C. albicans and reduction in colony forming unit (CFU) after 24 h treatment in the infected tooth samples in this model. Conclusion: The results of this study can pave the way for developing new antifungal agents with well deciphered mechanisms of action and can be a promising antifungal agent or medicament against root canal infection.

Keywords: C. albicans, ex vivo dentine model, inhibition of biofilm formation, root canal infection, yeast to hyphae conversion inhibition

Procedia PDF Downloads 208

Authors: Hugo Badia

Abstract:

This research answers which is the most suitable transit network structure to serve specific demand requirements in an increasing urban dispersion process. Two main approaches of network design are found in the literature. On the one hand, a traditional answer, widespread in our cities, that develops a high number of lines to connect most of origin-destination pairs by direct trips; an approach based on the idea that users averse to transfers. On the other hand, some authors advocate an alternative design characterized by simple networks where transfer is essential to complete most of trips. To answer which of them is the best option, we use a two-step methodology. First, by means of an analytical model, three basic network structures are compared: a radial scheme, starting point for the other two structures, a direct trip-based network, and a transfer-based one, which represent the two alternative transit network designs. The model optimizes the network configuration with regard to the total cost for each structure. For a scenario of dispersion, the best alternative is the structure with the minimum cost. This dispersion degree is defined in a simple way considering that only a central area attracts all trips. If this area is small, we have a high concentrated mobility pattern; if this area is too large, the city is highly decentralized. In this first step, we can determine the area of applicability for each structure in function to that urban dispersion degree. The analytical results show that a radial structure is suitable when the demand is so centralized, however, when this demand starts to scatter, new transit lines should be implemented to avoid transfers. If the urban dispersion advances, the introduction of more lines is no longer a good alternative, in this case, the best solution is a change of structure, from direct trips to a network based on transfers. The area of applicability of each network strategy is not constant, it depends on the characteristics of demand, city and transport technology. In the second step, we translate analytical results to a real case study by the relationship between the parameters of dispersion of the model and direct measures of dispersion in a real city. Two dimensions of the urban sprawl process are considered: concentration, defined by Gini coefficient, and centralization by area based centralization index. Once it is estimated the real dispersion degree, we are able to identify in which area of applicability the city is located. In summary, from a strategic point of view, we can obtain with this methodology which is the best network design approach for a city, comparing the theoretical results with the real dispersion degree.

Keywords: analytical network design model, network structure, public transport, urban dispersion

Procedia PDF Downloads 231

Authors: Muhammad Qasim, Dolors Puigjaner, Josep Maria López, Joan Herrero, Carme Olivé, Gerard Fortuny

Abstract:

Computational modeling of the human pelvis using the finite element (FE) method has become extremely important to understand the mechanics of prostate motion and deformation when transrectal ultrasound (TRUS) guided biopsy is performed. The number of reliable and validated hyperelastic constitutive FE models of the male pelvis region is limited, and given models did not precisely describe the anatomical behavior of pelvis organs, mainly of the prostate and its neoplasms location. The motion and deformation of the prostate during TRUS-guided biopsy makes it difficult to know the location of potential lesions in advance. When using this procedure, practitioners can only provide roughly estimations for the lesions locations. Consequently, multiple biopsy samples are required to target one single lesion. In this study, the whole pelvis model (comprised of the rectum, bladder, pelvic muscles, prostate transitional zone (TZ), and peripheral zone (PZ)) is used for the simulation results. An isotropic hyperelastic approach (Signorini model) was used for all the soft tissues except the vesical muscles. The vesical muscles are assumed to have a linear elastic behavior due to the lack of experimental data to determine the constants involved in hyperelastic models. The tissues and organ geometry is taken from the existing literature for 3D meshes. Then the biomechanical parameters were obtained under different testing techniques described in the literature. The acquired parametric values for uniaxial stress/strain data are used in the Signorini model to see the anatomical behavior of the pelvis model. The five mesh nodes in terms of small prostate lesions are selected prior to biopsy and each lesion’s final position is targeted when TRUS probe force of 30 N is applied at the inside rectum wall. Code_Aster open-source software is used for numerical simulations. Moreover, the overall effects of pelvis organ deformation were demonstrated when TRUS–guided biopsy is induced. The deformation of the prostate and neoplasms displacement showed that the appropriate material properties to organs altered the resulting lesion's migration parametrically. As a result, the distance traveled by these lesions ranged between 3.77 and 9.42 mm. The lesion displacement and organ deformation are compared and analyzed with our previous study in which we used linear elastic properties for all pelvic organs. Furthermore, the visual comparison of axial and sagittal slices are also compared, which is taken for Magnetic Resource Imaging (MRI) and TRUS images with our preliminary study.

Keywords: code-aster, magnetic resonance imaging, neoplasms, transrectal ultrasound, TRUS-guided biopsy

Procedia PDF Downloads 87

Authors: Mikhail V. Khachaturyan, Inga A. Koryagina, Eugenia V. Klicheva

Abstract:

In modern conditions, scientific judgment of problems in developing mechanisms of value creation and risk management acquires special relevance. Formation of economic knowledge has resulted in the constant analysis of consumer behavior for all players from national and world markets. Effective mechanisms development of the demand analysis, crucial for consumer's characteristics of future production, and the risks connected with the development of this production are the main objectives of control systems in modern conditions. The modern period of economic development is characterized by a high level of globalization of business and rigidity of competition. At the same time, the considerable share of new products and services costs has a non-material intellectual nature. The most successful in Russia is the contemporary development of small innovative firms. Such firms, through their unique technologies and new approaches to process management, which form the basis of their intellectual capital, can show flexibility and succeed in the market. As a rule, such enterprises should have very variable structure excluding the tough scheme of submission and demanding essentially new incentives for inclusion of personnel in innovative activity. Realization of similar structures, as well as a new approach to management, can be constructed based on value-oriented management which is directed to gradual change of consciousness of personnel and formation from groups of adherents included in the solution of the general innovative tasks. At the same time, valuable changes can gradually capture not only innovative firm staff, but also the structure of its corporate partners. Introduction of new technologies is the significant factor contributing to the development of new valuable imperatives and acceleration of the changing values systems of the organization. It relates to the fact that new technologies change the internal environment of the organization in a way that the old system of values becomes inefficient in new conditions. Introduction of new technologies often demands change in the structure of employee’s interaction and training in their new principles of work. During the introduction of new technologies and the accompanying change in the value system, the structure of the management of the values of the organization is changing. This is due to the need to attract more staff to justify and consolidate the new value system and bring their view into the motivational potential of the new value system of the organization.

Keywords: value, risk, creation, problems, organization

Procedia PDF Downloads 287

Authors: Shahram Naghizadeh Raeisi, Ali Alghooneh, Seyed Jalal Razavi Zahedkolaei

Abstract:

Herein, a shelf stable (no refrigeration required) UHT processed, aseptically packaged whey protein drink was formulated by using a new strategy in microparticulate process. Applying thermal and two-dimensional mechanical treatments simultaneously, a modified protein (MWPC-80) was produced. Then the physical, thermal and thermodynamic properties of MWPC-80 were assessed using particle size analysis, dynamic temperature sweep (DTS), and differential scanning calorimetric (DSC) tests. Finally, using MWPC-80, a new RTD beverage was formulated, and shelf stability was assessed for three months at ambient temperature (25 °C). Non-isothermal dynamic temperature sweep was performed, and the results were analyzed by a combination of classic rate equation, Arrhenius equation, and time-temperature relationship. Generally, results showed that temperature dependency of the modified sample was significantly (Pvalue<0.05) less than the control one contained WPC-80. The changes in elastic modulus of the MWPC did not show any critical point at all the processed stages, whereas, the control sample showed two critical points during heating (82.5 °C) and cooling (71.10 °C) stages. Thermal properties of samples (WPC-80 & MWPC-80) were assessed using DSC with 4 °C /min heating speed at 20-90 °C heating range. Results did not show any thermal peak in MWPC DSC curve, which suggested high thermal resistance. On the other hands, WPC-80 sample showed a significant thermal peak with thermodynamic properties of ∆G:942.52 Kj/mol ∆H:857.04 Kj/mole and ∆S:-1.22Kj/mole°K. Dynamic light scattering was performed and results showed 0.7 µm and 15 nm average particle size for MWPC-80 and WPC-80 samples, respectively. Moreover, particle size distribution of MWPC-80 and WPC-80 were Gaussian-Lutresian and normal, respectively. After verification of microparticulation process by DTS, PSD and DSC analyses, a 10% why protein beverage (10% w/w/ MWPC-80, 0.6% w/w vanilla flavoring agent, 0.1% masking flavor, 0.05% stevia natural sweetener and 0.25% citrate buffer) was formulated and UHT treatment was performed at 137 °C and 4 s. Shelf life study did not show any jellification or precipitation of MWPC-80 contained beverage during three months storage at ambient temperature, whereas, WPC-80 contained beverage showed significant precipitation and jellification after thermal processing, even at 3% w/w concentration. Consumer knowledge on nutritional advantages of whey protein increased the request for using this protein in different food systems especially RTD beverages. These results could make a huge difference in this industry.

Keywords: high protein whey beverage, micropartiqulation, two-dimentional mechanical treatments, thermodynamic properties

Procedia PDF Downloads 75

Authors: Cedillo Ortiz Cesar Isaac, Marañón-Ruiz Virginia-Francisca, Lozano-Alvarez Juan Antonio, Jáuregui-Rincón Juan, Roger Chiu Zarate

Abstract:

Introduction: The contamination of water with the azo-dye is a problem worldwide as although wastewater contaminate is treated in a municipal sewage system, still contain a considerable amount of dyes. In the present, there are different processes denominated tertiary method in which it is possible to lower the concentration of the dye. One of these methods is by adsorption onto various materials which can be organic or inorganic materials. The xanthan is a biomaterial as removal agents to decrease the dye content in aqueous solution. The Zimm-Bragg model described the experimental isotherms obtained when this biopolymer was used in the removal of textile dyes. Nevertheless, it was not established if a possible correlation between dye structure and removal efficiency exists. In this sense, the principal objective of this report is to propose a qualitative relationship between the structure of three azo-dyes (Congo Red (CR), Methyl Red (MR) and Methyl Orange (MO)) and their removal efficiency from aqueous environment when xanthan are used as dye sequestering agents. Methods: The dyes were subjected to different pH and ionic strength values to obtain the conditions of maximum dye removal. Afterward, these conditions were used to perform the adsorption isotherm as was reported in the previous study in our group. The Zimm-Bragg model was used to describe the experimental data and the parameters of nucleation (Ku) and cooperativity (U) were obtained by optimization using the R statistical software. The spectra from UV-Visible (aqueous solution), Infrared absorption and Raman spectroscopies (dry samples) were obtained from the biopolymer-dye complex. Results: The removal percent with xanthan in each dye are as follows: with CR had 99.98 % when the pH is 12 and ionic strength is 10.12, with MR had 84.79 % when the pH is 9.5 and ionic strength is 43 and finally the MO had 30 % in pH 4 and 72. It can be seen that when xanthan is used to remove the dyes, exists a lower dependence between structure and removal efficiency. This may be due to the different tendency to form aggregates of each dye. This aggregation capacity and the charge of each dye resulting from the pH and ionic strength values of aqueous solutions are key factors in the dye removal. The experimental isotherm of MR was only that adequately described by Zimm-Bragg model. Because with the CR had the 100 % of remove thus is very difficult obtain de experimental isotherm and finally MO had results fluctuating and therefore was impossible get the accurate data. Conclusions: The study of the removal of three dyes with xanthan as dye sequestering agents suggests that aggregation capacity of dyes and the charge resulting from structural characteristics such as molecular weight and functional groups have a relationship with the removal efficiency. Acknowledgements: We are gratefully acknowledged support for this project by Consejo Nacional de Ciencia y Tecnología, México (CONACyT, Grant No. 632694.)

Keywords: adsorption, azo dyes, xanthan gum, Zimm Bragg theory

Procedia PDF Downloads 281

Authors: B. Cilek Tatar, G. Sumnu, M. Oztop, E. Ayaz

Abstract:

Encapsulation protects sensitive food ingredients against heat, oxygen, moisture and pH until they are released to the system. It can mask the unwanted taste of nutrients that are added to the foods for fortification purposes. Cherry laurels (Prunus laurocerasus) contain phenolic compounds which decrease the proneness to several chronic diseases such as types of cancer and cardiovascular diseases. The objective of this research was to study the effects of centrifugation, different coating materials and homogenization methods on microencapsulation of powders obtained from cherry laurels. In this study, maltodextrin and mixture of maltodextrin:whey protein with a ratio of 1:3 (w/w) were chosen as coating materials. Total solid content of coating materials was kept constant as 10% (w/w). Capsules were obtained from powders of freeze-dried cherry laurels through encapsulation process by silent crusher homogenizer or microfluidization. Freeze-dried cherry laurels were core materials and core to coating ratio was chosen as 1:10 by weight. To homogenize the mixture, high speed homogenizer was used at 4000 rpm for 5 min. Then, silent crusher or microfluidizer was used to complete encapsulation process. The mixtures were treated either by silent crusher for 1 min at 75000 rpm or microfluidizer at 50 MPa for 3 passes. Freeze drying for 48 hours was applied to emulsions to obtain capsules in powder form. After these steps, dry capsules were grounded manually into a fine powder. The microcapsules were analyzed for total antioxidant activity with DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method. Prior to high speed homogenization, the samples were centrifuged (4000 rpm, 1 min). Centrifugation was found to have positive effect on total antioxidant activity of capsules. Microcapsules treated by microfluidizer were found to have higher total antioxidant activities than those treated by silent crusher. It was found that increasing whey protein concentration in coating material (using maltodextrin:whey protein 1:3 mixture) had positive effect on total antioxidant activity for both silent crusher and microfluidization methods. Therefore, capsules prepared by microfluidization of centrifuged mixtures can be selected as the best conditions for encapsulation of cherry laurel powder by considering their total antioxidant activity. In this study, it was shown that capsules prepared by these methods can be recommended to be incorporated into foods in order to enhance their functionality by increasing antioxidant activity.

Keywords: antioxidant activity, cherry laurel, microencapsulation, microfluidization

Procedia PDF Downloads 295

Authors: Antonio Casero Martínez, María de Lluch Rayo Llinas

Abstract:

This work is part of an investigation into the relationship between romantic love and self-esteem in college students, performed by the students of matter "methods and techniques of social research", of the Master Gender at the University of Balearic Islands, during 2014-2015. In particular, we have investigated the relationships that may exist between self-esteem, gender and field of study. They are known as gender differences in self-esteem, and the relationship between gender and branch of study observed annually by the distribution of enrolment in universities. Therefore, in this part of the study, we focused the spotlight on the differences in self-esteem between the sexes through the various branches of study. The study sample consists of 726 individuals (304 men and 422 women) from 30 undergraduate degrees that the University of the Balearic Islands offers on its campus in 2014-2015, academic year. The average age of men was 21.9 years and 21.7 years for women. The sampling procedure used was random sampling stratified by degree, simple affixation, giving a sampling error of 3.6% for the whole sample, with a confidence level of 95% under the most unfavorable situation (p = q). The Spanish translation of the Rosenberg Self-Esteen Scale (RSE), by Atienza, Moreno and Balaguer was applied. The psychometric properties of translation reach a test-retest reliability of 0.80 and an internal consistency between 0.76 and 0.87. In this paper we have obtained an internal consistency of 0.82. The results confirm the expected differences in self-esteem by gender, although not in all branches of study. Mean levels of self-esteem in women are lower in all branches of study, reaching statistical significance in the field of Science, Social Sciences and Law, and Engineering and Architecture. However, analysed the variability of self-esteem by the branch of study within each gender, the results show independence in the case of men, whereas in the case of women find statistically significant differences, arising from lower self-esteem of Arts and Humanities students vs. the Social and legal Sciences students. These findings confirm the results of numerous investigations in which the levels of female self-esteem appears always below the male, suggesting that perhaps we should consider separately the two populations rather than continually emphasize the difference. The branch of study, for its part has not appeared as an explanatory factor of relevance, beyond detected the largest absolute difference between gender in the technical branch, one in which women are historically a minority, ergo, are no disciplinary or academic characteristics which would explain the differences, but the differentiated social context that occurs within it.

Keywords: study branch, gender, self-esteem, applied psychology

Procedia PDF Downloads 467

Authors: Jeffrey L. Hurst, Sarah M. Coyne

Abstract:

With the growth of technology and media, teens are increasingly exposed to media such as pornography and engaging in risky media use such as sexting. Parental media mediation strategies including controlling or autonomy supporting strategies can be an important protective factor against risky media uses. The purpose of this study is to examine how parental media mediation around media, influence adolescents’ behaviors including frequency of pornography use and sexting. We also examine the effects of parental media mediation on adolescents disclosing pornography use to parents and the amount of secrets that adolescents keep about pornography use. We hypothesize that controlling media mediation will result in more sexting, more frequency pornography use, more secrets about pornography and less disclosure to parents. We also predict that autonomy supportive media mediation will show the opposite pattern. Data for this study came from a nationally representative research project, Project M.E.D.I.A. Participants included 783 adolescents. 49% of the participants were male, and the mean age for boys was 15.44 years (SD= 3.34) and for girls was 15.3 years (SD=2.93). Parental media mediation was assessed using an eight-item measure with subscales of controlling and autonomy supporting media mediation. Participants were also asked if they have ever viewed pornography. If they answered yes, they were asked about the frequency of pornography use as well as if they have ever kept secrets from their parents about it and if they had ever disclosed their pornography use to their parents. The data analysis strategy for this study was a multiple group path analysis. Frequency of pornography use, sexting, secrets from parents and disclosure to parents were predicted by controlling and autonomy supporting parental media mediation, frequency of parents warning against pornography use, income and ethnicity. Groups were distinguished by boys and girls, allowing for sex differences. After running the model in MPLUS, we found partial support for our hypotheses. Autonomy supportive media mediation resulted in less sexting for boys (β= -.15, p < .05) and girls ( β= -.13, p < .05). Autonomy supportive media mediation also predicted keeping fewer secrets for girls (β=-.27, p < .01) but had no effect for boys. Controlling media mediation predicted more disclosure about pornography to parents for boys (β=.16, p < .05) and less disclosure to parents about pornography for girls (β=-.14, p < .05). Frequency of pornography was not predicted by any of the predictors in the model. Autonomy supportive media mediation was a very strong predictor of less sexting for both boys and girls. Parents should approach media mediation with this supportive and understanding mindset. Parental autonomy support allows adolescents to explore and develop their own moral beliefs without feeling guilt or shame from their parents. This need to have autonomy is also shown by girls disclosing less pornography use to their parents when parents are really controlling about media use. Interestingly, boys disclosed more to their parents when their parents were controlling. Further research is needed on why this is. Further research should also look at the effects that disclosing pornography use to parents has on future pornography use.

Keywords: media, moral development, parental mediation, pornography, sexting

Procedia PDF Downloads 158

Authors: E. G. Karvelas, C. Liosis, A. Theodorakakos, T. E. Karakasidis

Abstract:

Magnetic navigation of the drug inside the human vessels is a very important concept since the drug is delivered to the desired area. Consequently, the quantity of the drug required to reach therapeutic levels is being reduced while the drug concentration at targeted sites is increased. Magnetic navigation of drug agents can be achieved with the use of magnetic nanoparticles where anti-tumor agents are loaded on the surface of the nanoparticles. The magnetic field that is required to navigate the particles inside the human arteries is produced by a magnetic resonance imaging (MRI) device. The main factors which influence the efficiency of the usage of magnetic nanoparticles for biomedical applications in magnetic driving are the size and the magnetization of the biocompatible nanoparticles. In this study, a computational platform for the simulation of the optimal gradient magnetic fields for the navigation of magnetic nanoparticles inside a carotid artery is presented. For the propulsion model of the particles, seven major forces are considered, i.e., the magnetic force from MRIs main magnet static field as well as the magnetic field gradient force from the special propulsion gradient coils. The static field is responsible for the aggregation of nanoparticles, while the magnetic gradient contributes to the navigation of the agglomerates that are formed. Moreover, the contact forces among the aggregated nanoparticles and the wall and the Stokes drag force for each particle are considered, while only spherical particles are used in this study. In addition, gravitational forces due to gravity and the force due to buoyancy are included. Finally, Van der Walls force and Brownian motion are taken into account in the simulation. The OpenFoam platform is used for the calculation of the flow field and the uncoupled equations of particles' motion. To verify the optimal gradient magnetic fields, a covariance matrix adaptation evolution strategy (CMAES) is used in order to navigate the particles into the desired area. A desired trajectory is inserted into the computational geometry, which the particles are going to be navigated in. Initially, the CMAES optimization strategy provides the OpenFOAM program with random values of the gradient magnetic field. At the end of each simulation, the computational platform evaluates the distance between the particles and the desired trajectory. The present model can simulate the motion of particles when they are navigated by the magnetic field that is produced by the MRI device. Under the influence of fluid flow, the model investigates the effect of different gradient magnetic fields in order to minimize the distance of particles from the desired trajectory. In addition, the platform can navigate the particles into the desired trajectory with an efficiency between 80-90%. On the other hand, a small number of particles are stuck to the walls and remains there for the rest of the simulation.

Keywords: artery, drug, nanoparticles, navigation

Procedia PDF Downloads 107

Authors: Ioannis N. Sergentanis, Stavroula Papadodima, Maria Tsellou, Dimitrios Vlachodimitropoulos, Sotirios Athanaselis, Chara Spiliopoulou

Abstract:

Introduction: The aim of this study is the investigation of characteristics of suicide, as documented in autopsies during a five-year interval in the greater area of Attica, including the city of Athens. This could reveal possible protective or aggravating factors for suicide risk during a period strongly associated with the Greek debt crisis. Materials and Methods: Data was obtained following registration of suicide cases among autopsies performed in the Forensic Medicine and Toxicology Department, School of Medicine, National and Kapodistrian University of Athens, Greece, during the time interval from January 2011 to December 2015. Anonymity and medical secret were respected. A series of demographic and social factors in addition to special characteristics of suicide were entered into a specially established pre-coded database. These factors include social data as well as psychiatric background and certain autopsy characteristics. Data analysis was performed using descriptive statistics and Fisher’s exact test. The software used was STATA/SE 13 (Stata Corp., College Station, TX, USA). Results: A total of 162 cases were studied, 128 men and 34 women. Age ranged from 14 to 97 years old with an average of 53 years, presenting two peaks around 40 and 60 years. A 56% of cases were single/ divorced/ widowed. 25% of cases occurred during the weekend, and 66% of cases occurred in the house. A predominance of hanging as the leading method of suicide (41.4%) followed by jumping from a height (22.8%) and firearms (19.1%) was noted. Statistical analysis showed an association was found between suicide method and gender (P < 0.001, Fisher’s exact test); specifically, no woman used a firearm while only one man used medication overdose (against four women). Discussion: Greece has historically been one of the countries with the lowest suicide rates in Europe. Given a possible change in suicide trends during the financial crisis, further research seems necessary in order to establish risk factors. According to our study, suicide is more frequent in men who are not married, inside their house. Gender seems to be a factor affecting the method of suicide. These results seem in accordance with the international literature. Stronger than expected predominance in male suicide can be associated with failure to live up to social and family expectations for financial reasons.

Keywords: autopsy, Greece, risk factors, suicide

Procedia PDF Downloads 221

Authors: Hamed Hedayatnia, Nathan Van Den Bossche

Abstract:

Understanding the ways in which climate change accelerates or slows down the process of material deterioration is the first step towards assessing adaptive approaches for the conservation of historical heritage. Analysis of the climate change effects on the degradation risk assessment parameters like freeze-thaw cycles and wind erosion is also a key parameter when considering mitigating actions. Due to the vulnerability of cultural heritage to climate change, the impact of this phenomenon on material degradation criteria with the focus on brick masonry walls in Timurid heritage, located in Iran, was studied. The Timurids were the final great dynasty to emerge from the Central Asian steppe. Through their patronage, the eastern Islamic world in northwestern of Iran, especially in Mashhad and Herat, became a prominent cultural center. Goharshad Mosque is a mosque in Mashhad of the Razavi Khorasan Province, Iran. It was built by order of Empress Goharshad, the wife of Shah Rukh of the Timurid dynasty in 1418 CE. Choosing an appropriate regional climate model was the first step. The outputs of two different climate model: the 'ALARO-0' and 'REMO,' were analyzed to find out which model is more adopted to the area. For validating the quality of the models, a comparison between model data and observations was done in 4 different climate zones in Iran for a period of 30 years. The impacts of the projected climate change were evaluated until 2100. To determine the material specification of Timurid bricks, standard brick samples from a Timurid mosque were studied. Determination of water absorption coefficient, defining the diffusion properties and determination of real density, and total porosity tests were performed to characterize the specifications of brick masonry walls, which is needed for running HAM-simulations. Results from the analysis showed that the threatening factors in each climate zone are almost different, but the most effective factor around Iran is the extreme temperature increase and erosion. In the north-western region of Iran, one of the key factors is wind erosion. In the north, rainfall erosion and mold growth risk are the key factors. In the north-eastern part, in which our case study is located, the important parameter is wind erosion.

Keywords: brick, climate change, degradation criteria, heritage, Timurid period

Procedia PDF Downloads 119

Authors: Aaron Kim, Nydia Hernandez

Abstract:

Despite the known deficits in sleep duration among adolescents and the increasing prevalence of substance use behaviors among this group, relatively little is known about how insufficient sleep is related to various substance use behaviors and the underlying mechanisms. Informed by the literature suggesting the predictive role of insufficient sleep for substance use and depressive symptoms, we hypothesized that adolescents who lack sufficient sleep during school nights would report a higher level of depressive symptoms and substance use than their counterparts with sufficient sleep. We also hypothesized that depressive symptoms would explain the association of insufficient sleep with substance use, suggesting that mental health plays an important role as a mechanism between insufficient sleep and substance use. This study used the data drawn from the 2019 Youth Risk Behavior Surveillance System Data, which includes a nationally representative sample of U.S. high school students (N=13,677, 49.4% Female, 9th-12th graders). Self-report measures of insufficient sleep (sleeping<7 h on an average school night), depressive symptoms (yes/no), any past 30-day use of cigarette (yes/no), e-cigarette (yes/no), alcohol (yes/no), and marijuana (yes/no). Among the total sample, 47.9% of students reported that they did not have sufficient sleep on school nights, indicating sleeping less than 7 hours. Regarding depressive symptoms, 36.7% of students reported feeling sad or hopeless almost every day for two weeks or more in a row during the past 12 months. Also, the percentages of students who reported one or more times of cigarette use, e-cigarette use, alcohol use, and marijuana use in the past month were 5.32%, 30.11%, 26.83%, and 21.65%, respectively. For bivariate associations among these study variables, insufficient sleep was positively associated with other variables: depressive symptoms (r=.08, p<.001), cigarette use (r=.03, p<.001), e-cigarette use (r=.04, p<.001), alcohol use (r=.07, p<.001), and marijuana use (r=.08, p<.001). After controlling for students’ characteristics (i.e., age, gender, race/ethnicity, grades), sleeping less than 7 hours on school nights (vs. sleeping more than 7 hours) was significantly associated with the past 30-day use of alcohol and marijuana, whereas cigarette and e-cigarette uses were not. That is, the students who reported having an insufficient sleep on school nights had higher odds of alcohol (Odds Ratio [OR]=1.15, 95% Confidence Interval [CI]=1.014-1.301) and marijuana use (OR=1.36, 95% CI=1.132-1.543). In a subsequent analysis including depressive symptoms together with insufficient sleep, the association of insufficient sleep with alcohol use (OR=1.13, 95% CI=1.011-1.297) and marijuana use (OR=1.33, 95% CI=1.130-1.521) were attenuated and explained by depressive symptoms. Depressive symptoms significantly increased the odds of alcohol use by 32.2% (OR=1.32, 95% CI=1.131-1.557) and marijuana use by 202.1% (OR=2.02, 95% CI=1.672-2.502). These findings together suggest that insufficient sleep may contribute to increased risks of substance uses among adolescents. The current study also shows that psychological disorders of adolescents play important roles in understanding the association between insufficient sleep and substance use, suggesting insufficient sleep is related to substance use indirectly through depressive symptoms. This study indicates the importance of sleep deprivation among adolescents and screening for insufficient sleep in preventing/intervening in substance use.

Keywords: adolescents, depressive symptoms, sleep, substance use

Procedia PDF Downloads 127

Authors: Wesley A. Saltarelli, Nicolas R. Finkler, Adriana C. P. Miwa, Maria C. Calijuri, Davi G. F. Cunha

Abstract:

The metabolism of the streams is an indicator of ecosystem disturbance due to the influences of the catchment on the structure of the water bodies. The study of the respiration and photosynthesis allows the estimation of energy fluxes through the food webs and the analysis of the autotrophic and heterotrophic processes. We aimed at evaluating the metabolism in streams located in the Brazilian savannah, Cerrado (Sao Carlos, SP), by determining and modeling the daily changes of dissolved oxygen (DO) in the water during one year. Three water bodies with minimal anthropogenic interference in their surroundings were selected, Espraiado (ES), Broa (BR) and Canchim (CA). Every two months, water temperature, pH and conductivity are measured with a multiparameter probe. Nitrogen and phosphorus forms are determined according to standard methods. Also, canopy cover percentages are estimated in situ with a spherical densitometer. Stream flows are quantified through the conservative tracer (NaCl) method. For the metabolism study, DO (PME-MiniDOT) and light (Odyssey Photosynthetic Active Radiation) sensors log data for at least three consecutive days every ten minutes. The reaeration coefficient (k2) is estimated through the method of the tracer gas (SF6). Finally, we model the variations in DO concentrations and calculate the rates of gross and net primary production (GPP and NPP) and respiration based on the one station method described in the literature. Three sampling were carried out in October and December 2015 and February 2016 (the next will be in April, June and August 2016). The results from the first two periods are already available. The mean water temperatures in the streams were 20.0 +/- 0.8C (Oct) and 20.7 +/- 0.5C (Dec). In general, electrical conductivity values were low (ES: 20.5 +/- 3.5uS/cm; BR 5.5 +/- 0.7uS/cm; CA 33 +/- 1.4 uS/cm). The mean pH values were 5.0 (BR), 5.7 (ES) and 6.4 (CA). The mean concentrations of total phosphorus were 8.0ug/L (BR), 66.6ug/L (ES) and 51.5ug/L (CA), whereas soluble reactive phosphorus concentrations were always below 21.0ug/L. The BR stream had the lowest concentration of total nitrogen (0.55mg/L) as compared to CA (0.77mg/L) and ES (1.57mg/L). The average discharges were 8.8 +/- 6L/s (ES), 11.4 +/- 3L/s and CA 2.4 +/- 0.5L/s. The average percentages of canopy cover were 72% (ES), 75% (BR) and 79% (CA). Significant daily changes were observed in the DO concentrations, reflecting predominantly heterotrophic conditions (respiration exceeded the gross primary production, with negative net primary production). The GPP varied from 0-0.4g/m2.d (in Oct and Dec) and the R varied from 0.9-22.7g/m2.d (Oct) and from 0.9-7g/m2.d (Dec). The predominance of heterotrophic conditions suggests increased vulnerability of the ecosystems to artificial inputs of organic matter that would demand oxygen. The investigation of the metabolism in the pristine streams can help defining natural reference conditions of trophic state.

Keywords: low-order streams, metabolism, net primary production, trophic state

Procedia PDF Downloads 259

Authors: Marilou Cadatal-Raduban, Minh Hong Pham, Duong Van Pham, Tu Nguyen Xuan, Mui Viet Luong, Kohei Yamanoi, Toshihiko Shimizu, Nobuhiko Sarukura, Hung Dai Nguyen

Abstract:

There is a great deal of interest in developing all-solid-state tunable ultrashort pulsed lasers emitting in the ultraviolet (UV) region for applications such as micromachining, investigation of charge carrier relaxation in conductors, and probing of ultrafast chemical processes. However, direct short-pulse generation is not as straight forward in solid-state gain media as it is for near-IR tunable solid-state lasers such as Ti:sapphire due to the difficulty of obtaining continuous wave laser operation, which is required for Kerr lens mode-locking schemes utilizing spatial or temporal Kerr type nonlinearity. In this work, the transient cavity method, which was reported to generate ultrashort laser pulses in dye lasers, is extended to a solid-state gain medium. Ce:LiCAF was chosen among the rare-earth-doped fluoride laser crystals emitting in the UV region because of its broad tunability (from 280 to 325 nm) and enough bandwidth to generate 3-fs pulses, sufficiently large effective gain cross section (6.0 x10⁻¹⁸ cm²) favorable for oscillators, and a high saturation fluence (115 mJ/cm²). Numerical simulations are performed to investigate the spectro-temporal evolution of the broadband UV laser emission from Ce:LiCAF, represented as a system of two homogeneous broadened singlet states, by solving the rate equations extended to multiple wavelengths. The goal is to find the appropriate cavity length and Q-factor to achieve the optimal photon cavity decay time and pumping energy for resonator transients that will lead to ps UV laser emission from a Ce:LiCAF crystal pumped by the fourth harmonics (266nm) of a Nd:YAG laser. Results show that a single ps pulse can be generated from a 1-mm, 1 mol% Ce³⁺-doped LiCAF crystal using an output coupler with 10% reflectivity (low-Q) and an oscillator cavity that is 2-mm long (short cavity). This technique can be extended to other fluoride-based solid-state laser gain media.

Keywords: rare-earth-doped fluoride gain medium, transient cavity, ultrashort laser, ultraviolet laser

Procedia PDF Downloads 359

Authors: Noa Nelson, Orit Appel, Rachel Ben-ari

Abstract:

Organizational Citizenship Behavior (OCB) is voluntary employee behavior that contributes to the organization beyond formal job requirements. It can take different forms, such as helping teammates (OCB toward individuals; hence, OCB-I), or staying after hours to attend a task force (OCB toward the organization; hence, OCB-O). Generally, OCB contributes substantially to organizational climate, goals, productivity, and resilience, so organizations need to understand what encourages it. This is particularly challenging in security organizations. Security work is characterized by high levels of stress and burnout, which is detrimental to OCB, and security organizational design emphasizes formal rules and clear hierarchies, leaving employees with less freedom for voluntary behavior. The current research explored the role of Perceived Procedural Justice (PPJ) in enhancing OCB in a security organization. PPJ refers to how fair decision-making processes are perceived to be. It involves the sense that decision makers are objective, attentive to everyone's interests, respectful in their communications and participatory - allowing individuals a voice in decision processes. Justice perceptions affect motivation, and it was specifically suggested that PPJ creates an attachment to one's organization and personal interest in its success. Accordingly, PPJ had been associated with OCB, but hardly any research tested their association with security organizations. The current research was conducted among prison guards in the Israel Prison Service, to test a correlational and a causal association between PPJ and OCB. It differentiated between perceptions of direct commander procedural justice (CPJ), and perceptions of organization procedural justice (OPJ), hypothesizing that CPJ would relate to OCB-I, while OPJ would relate to OCB-O. In the first study, 336 prison guards (305 male) from 10 different prisons responded to questionnaires measuring their own CPJ, OPJ, OCB-I, and OCB-O. Hierarchical linear regression analyses indicated the significance of commander procedural justice (CPJ): It associated with OCB-I and also associated with OPJ, which, in turn, associated with OCB-O. The second study tested CPJ's causal effects on prison guards' OCB-I and OCB-O; 311 prison guards (275 male) from 14 different prisons read scenarios that described either high or low CPJ, and then evaluated the likelihood of that commander's prison guards performing OCB-I and OCB-O. In this study, CPJ enhanced OCB-O directly. It also contributed to OCB-I, indirectly: CPJ enhanced the motivation for collaboration with the commander, which respondents also evaluated after reading scenarios. Collaboration, in turn, associated with OCB-I. The studies demonstrate that procedural justice, especially commander's PJ, promotes OCB in security work environments. This is important because extraordinary teamwork and motivation are needed to deal with emergency situations and with delicate security challenges. Following the studies, the Israel Prison Service implemented personal procedural justice training for commanders and unit level programs for procedurally just decision processes. From a theoretical perspective, the studies extend the knowledge on PPJ and OCB to security work environments and contribute evidence on PPJ's causal effects. They also call for further research, to understand the mechanisms through which different types of PPJ affect different types of OCB.

Keywords: organizational citizenship behavior, perceived procedural justice, prison guards, security organizations

Procedia PDF Downloads 221

Authors: Eliane G. Tótoli, Hérida Regina N. Salgado

Abstract:

Daptomycin is an important antimicrobial agent used in clinical practice nowadays, since it is very active against some Gram-positive bacteria that are particularly challenges for the medicine, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). The importance of environmental preservation has receiving special attention since last years. Considering the evident need to protect the natural environment and the introduction of strict quality requirements regarding analytical procedures used in pharmaceutical analysis, the industries must seek environmentally friendly alternatives in relation to the analytical methods and other processes that they follow in their routine. In view of these factors, green analytical chemistry is prevalent and encouraged nowadays. In this context, infrared spectroscopy stands out. This is a method that does not use organic solvents and, although it is formally accepted for the identification of individual compounds, also allows the quantitation of substances. Considering that there are few green analytical methods described in literature for the analysis of daptomycin, the aim of this work was the development and validation of a green analytical method for the quantification of this drug in lyophilized powder for injectable solution, by Fourier-transform infrared spectroscopy (FT-IR). Method: Translucent potassium bromide pellets containing predetermined amounts of the drug were prepared and subjected to spectrophotometric analysis in the mid-infrared region. After obtaining the infrared spectrum and with the assistance of the IR Solution software, quantitative analysis was carried out in the spectral region between 1575 and 1700 cm-1, related to a carbonyl band of the daptomycin molecule, and this band had its height analyzed in terms of absorbance. The method was validated according to ICH guidelines regarding linearity, precision (repeatability and intermediate precision), accuracy and robustness. Results and discussion: The method showed to be linear (r = 0.9999), precise (RSD% < 2.0), accurate and robust, over a concentration range from 0.2 to 0.6 mg/pellet. In addition, this technique does not use organic solvents, which is one great advantage over the most common analytical methods. This fact contributes to minimize the generation of organic solvent waste by the industry and thereby reduces the impact of its activities on the environment. Conclusion: The validated method proved to be adequate to quantify daptomycin in lyophilized powder for injectable solution and can be used for its routine analysis in quality control. In addition, the proposed method is environmentally friendly, which is in line with the global trend.

Keywords: daptomycin, Fourier-transform infrared spectroscopy, green analytical chemistry, quality control, spectrometry in IR region

Procedia PDF Downloads 381

Authors: Mjellma Rexhepi, Blerta Rexhepi Kelmendi, Blana Krasniqi, Shaip Krasniqi

Abstract:

Rheumatoid arthritis is a chronic disease that causes inflammation of the joints which can be so severe that can cause not only deformities but also impairment of function that limits movement. This also contributes to the pain that accompanies this disease. This remains a problematic and challenging disease of modern medicine because treatment is still symptomatic. The main purpose of drug treatment is to reduce the activity of the disease, achieve remission, avoid disability and death. The etiology of the disease is idiopathic, but can also be linked to genetic, nongenetic factors such as hormonal, environmental or infectious. Current scientific evidence shows that vitamin D plays an important role in immune regulation mechanisms. Lack of this vitamin has been linked to loss of immune tolerance and the appearance of autoimmune processes, including rheumatoid arthritis. The purpose of the work was to define Vitamin D in patients hospitalized with rheumatoid arthritis in University Clinical Center of Kosova, as a basis of their connection with lifestyle and physical inactivity. The sample for the work was selected from patients with criteria met for rheumatoid arthritis who were hospitalized at the tertiary level of health care in Kosova. During the work have been investigated 100 consecutive patients fulfilling diagnostic criteria for rheumatoid arthritis, whereas in addition to the general characteristics are also determined the values of vitamin D at the beginning of hospitalization. The average age of the sample analyzed was 50.9±5.7 years old, with an average duration of rheumatoid arthritis disease 7.8±3.4 years. At the beginning of hospitalization, before treatment was initiated, the average value of vitamin D was 15.86±3.43, which according to current reference values is classified into the category of insufficient values. Correlating the duration of the disease, from the time of diagnosis to the day of hospitalization, on one side and the level of vitamin D on the other side, the negative correlation of a lower degree derived (r =-0.1). Physical activity affects the concentration of vitamin D in the blood through increased metabolism of fat and the release of vitamin D and its metabolites from adipose tissue. To now it is evident that physical activity is also accompanied by higher levels of vitamin D. In patients with rheumatoid arthritis, vitamin D levels were low compared to normal. Future works should be oriented toward investigating in detail the bone structure, quality of life and pain in patients with rheumatoid arthritis. More detailed scientific projects, with larger numbers of participants, should be designed for the future to clarify more possible mechanisms as factors related to this phenomenon such as inactivity, lifestyle and the duration of the disease, as well as the importance of keeping vitamin D values at normal limits.

Keywords: hospitalization, lifestyle, rheumatoid arthritis, vitamin D

Procedia PDF Downloads 18

Authors: Akemi Nasu, Keiko Matsumoto

Abstract:

Rehabilitation for cancer requires setting up individual goals for each patient and an approach that properly fits the stage of cancer when putting into practice. In order to cope with the daily changes in the patients' condition, the establishment of a good cooperative relationship between the nurses and the physiotherapists, occupational therapists, and speech-language-hearing therapists (therapists) becomes essential. This study will focus on the present situation of the cooperation between nurses and therapists, especially the speech-language-hearing therapists, and aim to elucidate what develops there. A semi-structured interview was conducted targeted at a physical therapist having practical experience in working in collaboration with nurses. The contents of the interview were transcribed and converted to data, and the data was encoded and categorized with sequentially increasing degrees of abstraction to conduct a qualitative explorative factor analysis of the data. When providing ethical explanations, particular care was taken to ensure that participants would not be subjected to any disadvantages as a result of participating in the study. In addition, they were also informed that their privacy would be ensured and that they have the right to decline to participate in the study. In addition, they were also informed that the results of the study would be announced publicly at an applicable nursing academic conference. This study has been approved following application to the ethical committee of the university with which the researchers are affiliated. The survey participant is a female speech-language-hearing therapist in her forties. As a result of the analysis, 6 categories were extracted consisting of 'measures to address appetite and aspiration pneumonia prevention', 'limitation of the care a therapist alone could provide', 'the all-inclusive patient- supportive care provided by nurses', 'expand the beneficial cooperation with nurses', 'providing education for nurses on the swallowing function utilizing videofluoroscopic examination of swallowing', 'enhancement of communication including conferences'. In order to improve the team performance, and for the teamwork competency necessary for the provision of safer care, mutual support is essential. As for the cooperation between nurses and therapists, this survey indicates that the maturing of the cooperation between professionals in order to improve nursing professionals' knowledge and enhance communication will lead to an improvement in the quality of the rehabilitation for cancer.

Keywords: cancer rehabilitation, nurses, speech-language-hearing therapists, interprofessional work

Procedia PDF Downloads 134

Authors: Tadesse Kebede Dabsu

Abstract:

Insect pest is one the major limiting factor for sustainable food production. To overtake insect pest problem, since Second World War, producers have used excessive insecticide for insect pest management. However, in the era of 21st Century, the excessive use of insecticide caused insect resistant, insecticide bioaccumulation, insecticide hazard to environment, human health problem, and the like. Due to these problems, research efforts have been focused on the development of environmental free sustainable insect pest management method. To minimize all above mentioned risk utilizing of biological control such as entomopathogenicmicroorganism include bacteria, virus, fungus, and their productsare the best option for suppress insect population below certain density level. The objective of this review was to review the updated available studies and recent developments on the entomopathogenic bacteria (EPB) as biological control of insect pest and challenge of using them for control of insect pest. EPB’s mechanisms of insecticidal activities, type, taxonomy, and history are included in this paper body. EPB has been successfully used for the suppression of populations of insect pests. Controlling of harmful insect by entomopathogenic bacteria is an effective, low bioaccumulation in environment and food, very specific, reduce resistance risk in insect pest, economically and sustainable method of major insect pest management method. Identified and reported as potential major common type of entomopathogenic bacteria include Bacillus thuringiensis, Photorhabdus sp., Xenorhabdus spp.Walbachiaspp, Actinomycetesspp.etc. These bacteria being enter into insect body through natural opening or by vector release toxin protein inside of insect and disrupt the cell’s content cause natural mortality under natural condition. As per reported by different scientists, insect orders like Lepidoptera, Hemiptera, Hymenoptera, Coleoptera, and Dipterahave been successful controlled by entomopathogenic bacteria. As per coming across in different scientific research journals, much of the work was emphasised on Bacillus thuringiensisbsp. Therefore, for commercial production like Bacillus thuringiensi, detail research should be done on other bacteria species. The efficacy and practical application of EPB are restricted to some crops and greenhouse area, but their field application at farmers’ level very less. So still much work needs to be done to the practical application of the EPB at widely application. Their efficacy, pathogenicity, and host range test should be tested under environmental condition.

Keywords: insect pest, entomopathogenic bacteria, biological control, agent

Procedia PDF Downloads 139

Authors: Loveline Ambo Angwah

Abstract:

The processing of cassava from tubers or roots into food using crude and rudimentary method (hand peeling, grating, frying and to sun drying) is a very cumbersome and difficult process. The crude methods are time consuming and labour intensive. While on the other hand, modern processing method, that is using machines to perform the various processes as washing, peeling, grinding, oven drying, fermentation and frying is easier, less time consuming, and less labour intensive. Rudimentarily, cassava roots are processed into numerous products and utilized in various ways according to local customs and preferences. For the people of Ngwo village, cassava is transformed locally into flour or powder form called ‘cumcum’. It is also sucked into water to give a kind of food call ‘water fufu’ and fried to give ‘garri’. The leaves are consumed as vegetables. Added to these, its relative high yields; ability to stay underground after maturity for long periods give cassava considerable advantage as a commodity that is being used by poor rural folks in the community, to fight poverty. It plays a major role in efforts to alleviate the food crisis because of its efficient production of food energy, year-round availability, tolerance to extreme stress conditions, and suitability to present farming and food systems in Africa. Improvement of cassava processing and utilization techniques would greatly increase labor efficiency, incomes, and living standards of cassava farmers and the rural poor, as well as enhance the-shelf life of products, facilitate their transportation, increase marketing opportunities, and help improve human and livestock nutrition. This paper presents a general overview of crude ways in cassava processing and utilization methods now used by subsistence and small-scale farmers in Ngwo village of the North West region in Cameroon, and examine the opportunities of improving processing technologies. Cassava needs processing because the roots cannot be stored for long because they rot within 3-4 days of harvest. They are bulky with about 70% moisture content, and therefore transportation of the tubers to markets is difficult and expensive. The roots and leaves contain varying amounts of cyanide which is toxic to humans and animals, while the raw cassava roots and uncooked leaves are not palatable. Therefore, cassava must be processed into various forms in order to increase the shelf life of the products, facilitate transportation and marketing, reduce cyanide content and improve palatability.

Keywords: cassava roots, crude ways, food system, poverty

Procedia PDF Downloads 168