Search results for: planar traction force

Authors: Jitendra Pratap, Jonathan Sivyer

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Introduction: Dual energy/Spectral CT scanning permits simultaneous acquisition of two x-ray spectra datasets and can complement radiological diagnosis by allowing tissue characterisation (e.g., uric acid vs. non-uric acid renal stones), enhancing structures (e.g. boost iodine signal to improve contrast resolution), and quantifying substances (e.g. iodine density). However, the latter showed inconsistent results between the 2 main modes of dual energy scanning (i.e. dual source vs. dual layer). Therefore, the present study aimed to determine which technology is more accurate in quantifying iodine density. Methods: Twenty vials with known concentrations of iodine solutions were made using Optiray 350 contrast media diluted in sterile water. The concentration of iodine utilised ranged from 0.1 mg/ml to 1.0mg/ml in 0.1mg/ml increments, 1.5 mg/ml to 4.5 mg/ml in 0.5mg/ml increments followed by further concentrations at 5.0 mg/ml, 7mg/ml, 10 mg/ml and 15mg/ml. The vials were scanned using Dual Energy scan mode on a Siemens Somatom Force at 80kV/Sn150kV and 100kV/Sn150kV kilovoltage pairing. The same vials were scanned using Spectral scan mode on a Philips iQon at 120kVp and 140kVp. The images were reconstructed at 5mm thickness and 5mm increment using Br40 kernel on the Siemens Force and B Filter on Philips iQon. Post-processing of the Dual Energy data was performed on vendor-specific Siemens Syngo VIA (VB40) and Philips Intellispace Portal (Ver. 12) for the Spectral data. For each vial and scan mode, the iodine concentration was measured by placing an ROI in the coronal plane. Intraclass correlation analysis was performed on both datasets. Results: The iodine concentrations were reproduced with a high degree of accuracy for Dual Layer CT scanner. Although the Dual Source images showed a greater degree of deviation in measured iodine density for all vials, the dataset acquired at 80kV/Sn150kV had a higher accuracy. Conclusion: Spectral CT scanning by the dual layer technique has higher accuracy for quantitative measurements of iodine density compared to the dual source technique.

Keywords: CT, iodine density, spectral, dual-energy

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Authors: I. S. R. Butswat, D. Zahraddeen

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This study identified and described some skill-based and necessity-driven entrepreneurship in animal agriculture (AA). AA is an integral segment of the world food industry, and provides a good and rapid source of income. The contribution of AA to the Sub-Saharan economy is quite significant, and there are still large opportunities that remain untapped in the sector. However, it is imperative to understand, simplify and package the various components of AA in order to pave way for rapid wealth creation, poverty eradication and women empowerment programmes in sub-Saharan Africa and other developing countries. The entrepreneurial areas of AA highlighted were animal breeding, livestock fattening, dairy production, poultry farming, meat production (beef, mutton, chevon, etc.), rabbit farming, wool/leather production, animal traction, animal feed industry, commercial pasture management, fish farming, sport animals, micro livestock production, private ownership of abattoirs, slaughter slabs, animal parks and zoos, among others. This study concludes that reproductive biotechnology such as oestrous synchronization, super-/multiple ovulation, artificial insemination and embryo transfer can be employed as a tool for improvement of genetic make-up of low-yielding animals in terms of milk, meat, egg, wool, leather production and other economic traits that will necessitate sustainable job and wealth creations.

Keywords: animal, agriculture, entreprenurship, wealth

Procedia PDF Downloads 246

Authors: Jhonnatan Eduardo Zamudio Palacios, Oscar Leonardo Mosquera Dussan, Daniel Guzman Perez, Daniel Alfonso Botero Rosas, Oscar Fabian Rubiano Espinosa, Jose Antonio Garcia Torres, Ivan Dario Chavarro, Ivan Ramiro Rodriguez Camacho, Jaime Orlando Rodriguez

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The training of cilsitas with some type of disability finds in the technological development an indispensable ally, generating every day advances to contribute to the quality of life allowing to maximize the capacities of the athletes. The performance of a cyclist depends on physiological and biomechanical factors, such as aerodynamic profile, bicycle measurements, connecting rod length, pedaling systems, type of competition, among others. This study particularly focuses on the description of the dynamic model of a transtibial prosthesis for Paralympic cyclists. To make the model, two points are chosen: in the radius centers of rotation of the plate and pinion of the track bicycle. The parametric scheme of the track bike represents a model of 6 degrees of freedom due to the displacement in X - Y of each of the reference points of the angles of the curve profile β, cant of the velodrome α and the angle of rotation of the connecting rod φ. The force exerted on the crank of the bicycle varies according to the angles of the curve profile β, the velodrome cant of α and the angle of rotation of the crank φ. The behavior is analyzed through the Matlab R2015a software. The average strength that a cyclist exerts on the cranks of a bicycle is 1,607.1 N, the Paralympic cyclist must perform a force on each crank about 803.6 N. Once the maximum force associated with the movement has been determined, it is continued to the dynamic modeling of the transtibial prosthesis that represents a model of 6 degrees of freedom with displacement in X - Y in relation to the angles of rotation of the hip π, knee γ and ankle λ. Subsequently, an analysis of the kinematic behavior of the prosthesis was carried out by means of SolidWorks 2017 and Matlab R2015a, which was used to model and analyze the variation of the hip angles π, knee γ and ankle of the λ prosthesis. The reaction forces generated in the prosthesis were performed on the ankle of the prosthesis, performing the summation of forces on the X and Y axes. The same analysis was then applied to the tibia of the prosthesis and the socket. The reaction force of the parts of the prosthesis varies according to the hip angles π, knee γ and ankle of the prosthesis λ. Therefore, it can be deduced that the maximum forces experienced by the ankle of the prosthesis is 933.6 N on the X axis and 2.160.5 N on the Y axis. Finally, it is calculated that the maximum forces experienced by the tibia and the socket of the transtibial prosthesis in high performance competitions is 3.266 N on the X axis and 1.357 N on the Y axis. In conclusion, it can be said that the performance of the cyclist depends on several physiological factors, linked to biomechanics of training. The influence of biomechanical factors such as aerodynamics, bicycle measurements, connecting rod length, or non-circular pedaling systems on the cyclist performance.

Keywords: biomechanics, dynamic model, paralympic cyclist, transtibial prosthesis

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Authors: Mikko Hänninen

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This paper explores the effect online retail platforms have on customer behavior and retail patronage through an inductive multi-case study. Existing research on retail platforms and ecosystems generally focus on competition between platform members and most papers maintain a managerial perspective with customers seen mainly as merely one stakeholder of the value-exchange relationship. It is proposed that retail platforms change the nature of customer relationships compared to traditional brick-and-mortar or e-commerce retailers. With online retail platforms such as Alibaba, Amazon and Rakuten gaining increasing traction with their platform based business models, the purpose of this paper is to define retail platforms and look at how leading retail platforms are able to create value for their customers, in order to foster meaningful customer’ relationships. An analysis is conducted on the major global retail platforms with a focus specifically on understanding the tools in place for creating customer value in order to show how retail platforms create and maintain customer relationships for fostering customer loyalty. The results describe the opportunities and challenges retailers face when competing against platform based businesses and outline the advantages as well as disadvantages that platforms bring to individual consumers. Based on the inductive case research approach, five theoretical propositions on consumer behavior in online retail platforms are developed that also form the basis of further research with this research making both a practical as well as theoretical contribution to platform research streams.

Keywords: retail, platform, ecosystem, e-commerce, loyalty

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Authors: Chro Kavian

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The studies conducted show that cancer is a disease caused by populations of microbes, a notion gaining traction as the interaction between the human microbiome and the tumor microenvironment (TME) increasingly shows how environment and microbes dictate the progress and treatment of neoplastic diseases. A person’s human microbiome is defined as a collection of bacteria, fungi, viruses, and other microorganisms whose structure and composition influence biological processes like immune system modulation and nutrient metabolism, which, in turn, affect how susceptible a person is to neoplastic diseases, and response to different therapies. Recent reports demonstrated the influence specific microbiome bacterial populations have on the TME, thereby altering tumoral behaviors and the TME’s contributing factors that impact patients' lives. In addition, gut microbes and their SCFA products are important determinants of the inflammatory landscape of tumors and augment anti-tumor immunity, which can influence immunotherapy outcomes. Studies have also found that dysbiosis, or microbial imbalance, correlates with biological processes such as cancer progression, metastasis, and therapy resistance, leading scientists to explore the use of microbiome deficiencies as adjunctive approaches to chemotherapy and other, more traditional treatments. Nonetheless, mental health practitioners struggling to comprehend the existent gap between cancer patients with pronounced resolutive capabilities and the profound clinical impact Microbiome-targeted cancer therapy has been proven to possess.

Keywords: microbiome, cancer, tumor, immune system

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Authors: Wei-Po Wu, Wen-Yu Liu, Wei−Ting Lin, Hen-Yu Lien

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Introduction: Improving balance function for individuals after stroke is a crucial target in physiotherapy. Aquatic therapy which challenges individual’s postural control in an unstable fluid environment may be beneficial in enhancing balance functions. The purposes of the systematic review with meta-analyses were to validate the effects of aquatic therapy in improving balance functions for individuals with strokes in contrast to conventional physiotherapy. Method: Available studies were explored from three electronic databases: PubMed, Scopus, and Web of Science. During literature search, the published date of studies was not limited. The study design of the included studies should be randomized controlled trials (RCTs) and the studies should contain at least one outcome measurement of balance function. The PEDro scale was adopted to assess the quality of included studies, while the 'Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence' was used to evaluate the level of evidence. After the data extraction, studies with same outcome measures were pooled together for meta-analysis. Result: Ten studies with 282 participants were included in analyses. The research qualities of the studies were ranged from fair to good (4 to 8 points). Levels of evidence of the included studies were graded as level 2 and 3. Finally, scores of Berg Balance Scale (BBS), Eye closed force plate center of pressure velocity (anterior-posterior, medial-lateral axis) and Timed up and Go test were pooled and analyzed separately. The pooled results shown improvement in balance function (BBS mean difference (MD): 1.39 points; 95% confidence interval (CI): 0.05-2.29; p=0.002) (Eye closed force plate center of pressure velocity (anterior-posterior axis) MD: 1.39 mm/s; 95% confidence interval (CI): 0.93-1.86; p<0.001) (Eye closed force plate center of pressure velocity (medial-lateral) MD: 1.48 mm/s; 95% confidence interval (CI): 0.15-2.82; p=0.03) and mobility (MD: 0.9 seconds; 95% CI: 0.07-1.73; p=0.03) of stroke individuals after aquatic therapy compared to conventional therapy. Although there were significant differences between two treatment groups, the differences in improvement were relatively small. Conclusion: The aquatic therapy improved general balance function and mobility in the individuals with stroke better than conventional physiotherapy.

Keywords: aquatic therapy, balance function, meta-analysis, stroke, systematic review

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Authors: Kashif Nesar Rather, Mantu Kumar Mahalik

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The discourse surrounding climate change has gained considerable traction, with a discernible emphasis on its nuanced and consequential impact on gender inequality. Concurrently, escalating global tensions are contributing to heightened uncertainty, potentially exerting influence on gender disparities. Within this framework, this study attempts to empirically investigate the implications of climate change and world uncertainty on the gender inequality for a balanced panel of 100 economies between 1995 to 2021. The estimated models also control for the effects of globalisation, economic growth, and education expenditure. The panel cointegration tests establish a significant long-run relationship between the variables of the study. Furthermore, the PMG-ARDL (Panel mean group-Autoregressive distributed lag model) estimation technique confirms that both climate change and world uncertainty perpetuate the global gender inequalities. Additionally, the results establish that globalisation, economic growth, and education expenditure exert a mitigating influence on gender inequality, signifying their role in diminishing gender disparities. These findings are further confirmed by the FGLS (Feasible Generalized Least Squares) and DKSE (Driscoll-Kraay Standard Errors) regression methods. Potential policy implications for mitigating the detrimental gender ramifications stemming from climate change and rising world uncertainties are also discussed.

Keywords: gender inequality, world uncertainty, climate change, globalisation., ecological footprint

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Authors: S. Kampeephat, P. Krachodnok, R. Wongsan

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The conventional rectangular horn has been used for microwave antenna a long time. Its gain can be increased by enlarging the construction of horn to flare exponentially. This paper presents a study of the shaped woodpile Electromagnetic Band Gap (EBG) to improve its gain for conventional horn without construction enlargement. The gain enhancement synthesis method for shaped woodpile EBG that has to transfer the electromagnetic fields from aperture of a horn antenna through woodpile EBG is presented by using the variety of shaped woodpile EBGs such as planar, triangular, quadratic, circular, gaussian, cosine, and squared cosine structures. The proposed technique has the advantages of low profile, low cost for fabrication and light weight. The antenna characteristics such as reflection coefficient (S11), radiation patterns and gain are simulated by utilized A Computer Simulation Technology (CST) software. With the proposed concept, an antenna prototype was fabricated and experimented. The S11 and radiation patterns obtained from measurements show a good impedance matching and a gain enhancement of the proposed antenna. The gain at dominant frequency of 10 GHz is 25.6 dB, application for X- and Ku-Band Radar, that higher than the gain of the basic rectangular horn antenna around 8 dB with adding only one appropriated EBG structures.

Keywords: conventional rectangular horn antenna, electromagnetic band gap, gain enhancement, X- and Ku-band radar

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Authors: Xiuguo Zhao, He Li, Alireza Yazdani, Xiaoning Zheng, Xinxi Xu

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Wound infected poses a serious threat to the surgery on the patient during the process of surgery. Understanding the bacteria-carrying particles (BCPs) transportation and deposition in the open surgical wound model play essential role in protecting wound against being infected. Therefore BCPs transportation and deposition in the surgical wound model were investigated using force-coupling method (FCM) based computational fluid dynamics. The BCPs deposition in the wound was strongly associated with BCPs diameter and concentration. The results showed that the rise on the BCPs deposition was increasing not only with the increase of BCPs diameters but also with the increase of the BCPs concentration. BCPs deposition morphology was impacted by the combination of size distribution, airflow patterns and model geometry. The deposition morphology exhibited the characteristic with BCPs deposition on the sidewall in wound model and no BCPs deposition on the bottom of the wound model mainly because the airflow movement in one direction from up to down and then side created by laminar system constructing airflow patterns and then made BCPs hard deposit in the bottom of the wound model due to wound geometry limit. It was also observed that inertial impact becomes a main mechanism of the BCPs deposition. This work may contribute to next study in BCPs deposition limit, as well as wound infected estimation in surgical-site infections.

Keywords: BCPs deposition, computational fluid dynamics, force-coupling method (FCM), numerical simulation, open surgical wound model

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Authors: Salima Djehaichia, Rachid Lassoued

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Reinforced concrete structural walls are very efficient elements for protecting buildings against excessive early damage and against collapse under earthquake actions. It is therefore of interest to develop a numerical model which simulates the typical behavior of these units, this paper presents and describes different modeling techniques that have been used by researchers and their advantages and limitations mentioned. The earthquake of Boumerdes in 2003 has demonstrated the fragility of structures and total neglect of sismique design rules in the realization of old buildings. Significant damage and destruction of buildings caused by this earthquake are not due to the choice of type of material, but the design and the study does not congruent with seismic code requirements and bad quality of materials. For idealizing the failure of rules, a parametric study focuses on: low rate of reinforcements, type of reinforcement, resistance moderate of concrete. As an application the modeling strategy based on finite elements combined with a discretization of wall more solicited by successive thin layers. The estimated performance level achieved during a seismic action is obtained from capacity curves under incrementally increasing loads. Using a pushover analysis, a characteristic non linear force-displacement relationship can be determined. The results of numeric model are confronted with those of Algerian Para seismic Rules (RPA) in force have allowed the determination of profits in terms of displacement, shearing action, ductility.

Keywords: modeling, old building, pushover analysis, structural walls

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Authors: Justyna Skrzyńska, Zdzisław Kobos, Zbigniew Wochyński

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The assessment of characterologic type is an essential element which decides about the proper task performance in the Air Forces. The aim of the research was to specify the percentage distribution of characterologic features by cadets studying particular courses in Polish Air Force Academy with the use of questionnaire. 34 first-year cadets chosen by lot and disunited into aircrafts pilots (N-10), helicopter pilots (N-13) and navigators(N-11) participated in the research. All of the questioned have had their psychomotor education examined in Military Aviation Medicine Institute in Warsaw, Poland. Moreover all of them are characterised by very good fitness. In the research, an anonymous poll(based on Myers-Briggs Type Indicator) appraising cadets’ characterologic type has been used. Cadets were provided with the same accommodation and nutrition. The findings have shown that percentage distribution was diversified, however it could be distinctly observed that most of future helicopter pilots (69%) are introverts whereas the majority of aircrafts pilots (70%) and navigators (100%) are extraverts. Moreover, it was also observed that 70% of cadets studying aircrafts pilotage run regular lifestyle and have judging skill according to Myers-Briggs Type Indicator. In future navigators group, 73% of students do not have this characteristic. The research has shown that cadets studying pilotage are more likely to demonstrate the characteristics which are essential for a performance of the important tasks in pilots environment than the cadets studying navigation.

Keywords: pilot, Myers-Briggs Type indicator, questionnaire research, cadets, psychomotor education

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Authors: Maria Elisabete Costa Ferreira

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Domestic violence is a serious social issue in which victims are mostly women. Domestic violence develops in cycles, starting with the building of tension, passing through the incident of abuse and ending with reconciliation, also known as honeymoon. As time goes by, the shorter these phases become, and the greater and more severe the attacks, rarely leading to the death of the victim of abuse. Sometimes, the victim stops the abuse by killing the aggressor, usually after the immediate aggression has taken place. This poses an important obstacle to the claim of self-defense by the victim of domestic violence pending trial for the homicide of her long-time abuser. The main problem with self-defense claims in such cases is that the law requires the act of aggression to be present or imminent (imminent threat or immediate danger) so that it permits the victim to take her defense into her own hands. If the episode of aggression has already taken place, this general requirement for the admissibility of self-defense is not satisfied. This paper sheds new light on the concept of the actuality of the aggression, understanding that, since domestic violence is a permanent offense, for as long as the victim stays under the domain of the aggressor, imminent threat will be present, allowing the self-defense claim of a woman who kills her abuser in such circumstances to be admissible. An actualist interpretation of the requirement of the necessity of the means used in self-defense will be satisfied when evaluated from the subjective perspective of the intimate partner victim. Necessity will be satisfied if it is reasonable for the victim to perceive the use of lethal force as the only means to release herself from the abuser.

Keywords: domestic violence, homicide, self-defense, imminent threat, necessity of lethal force

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Authors: Chai Mingming, Li Lei, Lu Xiaoxia

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In this paper, the mechanism of stratified liquids’ mixing in a cylinder is investigated. It is focused on the effects of Rayleigh-Taylor Instability (RTI) and rotation of the cylinder on liquid interface mixing. For miscible liquids, Planar Laser Induced Fluorescence (PLIF) technique is applied to record the concentration field for one liquid. Intensity of Segregation (IOS) is used to describe the mixing status. For immiscible liquids, High Speed Camera is adopted to record the development of the interface. The experiment of RTI indicates that it plays a great role in the mixing process, and meanwhile the large-scale mixing is triggered, and subsequently the span of the stripes decreases, showing that the mesoscale mixing is coming into being. The rotation experiments show that the spin-down process has a great role in liquid mixing, during which the upper liquid falls down rapidly along the wall and crashes into the lower liquid. During this process, a lot of interface instabilities are excited. Liquids mix rapidly in the spin-down process. It can be concluded that no matter what ways have been adopted to speed up liquid mixing, the fundamental reason is the interface instabilities which increase the area of the interface between liquids and increase the relative velocity of the two liquids.

Keywords: interface instability, liquid mixing, Rayleigh-Taylor Instability, spin-down process, spin-up process

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Authors: Phillip Thebe

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African traders in China have generated magnanimous attention from scholars because of their choices to take short-term trips to Guangzhou and other places in search of cheaper products taking advantage of the status of China as a "global manufacturing hub". Nevertheless, their activities only gained traction at the turn of the millennium, with their presence in China incrementally dwindling over the next two decades. Now, with the devastating effects of COVID-19, their journeys have had to be totally cut short by unending lockdowns and stiff migration rules due to China's zero-tolerance of COVID-19 policy. This unfortunate yet untimely occurrence has left many scholars wondering if this marks the end of African traders in China and, indeed, the end of their business careers. Between March and September 2022, 20 traders were followed back to Africa, Zimbabwe, to find out what they are doing after having been shut out of China. Data was collected through ethnographic immersion and purposive in-depth interviewing in and around the city of Bulawayo. Snowballing was employed to reach out to the traders until a saturation point was reached and interview transcripts were filed for analysis. The findings revealed that some still trading online in China, report different opinions and feelings about doing business during COVID-19. Others have left the Chinese marketplace, now pursuing European industries in Turkey and other places. Others are still getting Chinese goods but in African countries such as Tanzania, Mozambique, South Africa, and Botswana. Some are now into the second-hand clothing trade, whereas others have stopped doing business to pursue other life-course interests. These and other issues are addressed in this paper from the anthropology of migration and globalization perspectives.

Keywords: entrepreneurship, African traders, China, COVID-19, Africans in China

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Authors: Karim Kheloufi, El Hachemi Amara

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In the present study, a three-dimensional transient numerical model was developed to study the temperature field and cutting kerf shape during laser fusion cutting. The finite volume model has been constructed, based on the Navier–Stokes equations and energy conservation equation for the description of momentum and heat transport phenomena, and the Volume of Fluid (VOF) method for free surface tracking. The Fresnel absorption model is used to handle the absorption of the incident wave by the surface of the liquid metal and the enthalpy-porosity technique is employed to account for the latent heat during melting and solidification of the material. To model the physical phenomena occurring at the liquid film/gas interface, including momentum/heat transfer, a new approach is proposed which consists of treating friction force, pressure force applied by the gas jet and the heat absorbed by the cutting front surface as source terms incorporated into the governing equations. All these physics are coupled and solved simultaneously in Fluent CFD®. The main objective of using a transient phase change model in the current case is to simulate the dynamics and geometry of a growing laser-cutting generated kerf until it becomes fully developed. The model is used to investigate the effect of some process parameters on temperature fields and the formed kerf geometry.

Keywords: laser cutting, numerical simulation, heat transfer, fluid flow

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Authors: Maria Pintea, Nigel Mason

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Induced chemistry is one of the newest pathways in the nanotechnology field with applications in the focused electron beam induced processes for deposition of nm scale structures. Si(OPr)₄ and Ti(OEt)₄ are two of the precursors that have not been so extensively researched, though highly sought for semiconductor and medical applications fields, the two compounds make good candidates for FEBIP and are the subject of velocity slice map imaging analysis for deposition purposes, offering information on kinetic energies, fragmentation channels, and angular distributions. The velocity slice map imaging technique is a method used for the characterization of molecular dynamics of the molecule and the fragmentation channels as a result of induced chemistry. To support the gas-phase analysis, Meso-Bio-Nano simulations of irradiation dynamics studies are employed with final results on Fe(CO)₅ deposited on various substrates. The software is capable of running large scale simulations for complex biomolecular, nano- and mesoscopic systems with applications to thermos-mechanical DNA damage, complex materials, gases, nanoparticles for cancer research and deposition applications for nanotechnology, using a large library of classical potentials, many-body force fields, molecular force fields involved in the classical molecular dynamics.

Keywords: focused electron beam induced deposition, FEBID, induced chemistry, molecular dynamics, velocity map slice imaging

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Authors: Marco Furinghetti, Alberto Pavese, Michele Rinaldi

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Concave Surface Slider devices have been more and more used in real applications for seismic protection of both bridge and building structures. Several research activities have been carried out, in order to investigate the lateral response of such a typology of devices, and a reasonably high level of knowledge has been reached. If radial analysis is performed, the frictional force is always aligned with respect to the restoring force, whereas under bidirectional seismic events, a bi-axial interaction of the directions of motion occurs, due to the step-wise projection of the main frictional force, which is assumed to be aligned to the trajectory of the isolator. Nonetheless, if non-linear time history analyses have to be performed, standard codes provide precise rules for the definition of an averagely spectrum-compatible set of accelerograms in radial conditions, whereas for bidirectional motions different combinations of the single components spectra can be found. Moreover, nowadays software for the adjustment of natural accelerograms are available, which lead to a higher quality of spectrum-compatibility and to a smaller dispersion of results for radial motions. In this endeavor a simplified design procedure is defined, for building structures, base-isolated by means of Concave Surface Slider devices. Different case study structures have been analyzed. In a first stage, the capacity curve has been computed, by means of non-linear static analyses on the fixed-base structures: inelastic fiber elements have been adopted and different direction angles of lateral forces have been studied. Thanks to these results, a linear elastic Finite Element Model has been defined, characterized by the same global stiffness of the linear elastic branch of the non-linear capacity curve. Then, non-linear time history analyses have been performed on the base-isolated structures, by applying seven bidirectional seismic events. The spectrum-compatibility of bidirectional earthquakes has been studied, by considering different combinations of single components and adjusting single records: thanks to the proposed procedure, results have shown a small dispersion and a good agreement in comparison to the assumed design values.

Keywords: concave surface slider, spectrum-compatibility, bidirectional earthquake, base isolation

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Authors: Claudeline D. Cellan

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Development is multifaceted, and efforts to hasten growth in all these facets have been gaining traction in recent years. Thus, producing a composite index that is reflective of these multidimensional impacts captures the interests of policymakers. The problem lies in going through a mixture of theoretical, methodological and empirical decisions and complexities which, when done carelessly, can lead to inconsistent and unreliable results. This study looks into index computation from a different and less complex perspective. Borrowing the idea of archetypes or ‘pure types’, archetypal analysis looks for points in the convex hull of the multivariate data set that captures as much information in the data as possible. The archetypes or 'pure types' are estimated such that they are convex combinations of all the observations, which in turn are convex combinations of the archetypes. This ensures that the archetypes are realistically observable, therefore achievable. In the sense of composite indices, we look for the best among these archetypes and use this as a benchmark for index computation. Its straightforward and simplistic approach does away with aggregation and substitutability problems which are commonly encountered in index computation. As an example of the application of archetypal analysis in index construction, the country data for the Human Development Index (HDI 2017) of the United Nations Development Programme (UNDP) is used. The goal of this exercise is not to replicate the result of the UNDP-computed HDI, but to illustrate the usability of archetypal analysis in index construction. Here best is defined in the context of life, education and gross national income sub-indices. Results show that the HDI from the archetypal analysis has a linear relationship with the UNDP-computed HDI.

Keywords: archetypes, composite index, convex combination, development

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Authors: Biskri Yasmina, Laidi Babouri, Dehas Ouided, Bougherira Nadjiba, Baghloul Rahima

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Algeria is one of the countries which have extraordinary resources in vegetable fibers (Palmier, Alfa, Cotton, Sisal). Unfortunately, their valorization in the practical fields, among other things, in building materials, is still little exploited. Several works align with the fact that the use of plant fibers in mortar is an advantageous solution, given its abundance and its socio-economic and environmental impact. The idea of introducing plant fiber into the field of Civil Engineering is not new. Based on the work of several researchers in this field, we propose to study the mechanical behavior of mortar based on Sisal fibers. This work consists of the experimental characterization in the fresh state (workability) and in the hardened state (mechanical resistance to compression and traction by three-point bending) on the scale of mortar mortars based on sisal plant fibers. The main objective of this work is the study of the effect of fiber incorporation on mechanical properties (compressive strength and three-point bending strength). In this study, we varied two parameters, such as the length of the fiber (7cm, 10 cm) and the fibers percentage (0.25%, 0.5%, 0.75%, 1%, 1.25% and 1.5%). The results show that there is a slight increase in the compressive strength of the fiber-reinforced mortars compared to the reference mortar (mortar without fibers). With regard to the three-point bending tests, the fiber-reinforced mortars presented higher resistances compared to the reference mortar and this was for the different lengths and different percentages studied.

Keywords: mortar, plant fiber, experimentation, mechanical characterization, analysis

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Authors: Orla McConnell, Cormac MacMahon, Jen Harvey

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Ireland’s national professional development framework for those who teach in higher education, aims to provide guidance and leadership in the planning, developing and engaging in professional development practices. A series of pilot projects have been initiated to help explore the framework’s likely utility and acceptance by educators and their institutions. These projects require engagement with staff in the interpretation and adaption of the framework within their working contexts. The purpose of this paper is to outline the development of one such project with engineering educators at three Institutes of Technology seeking designation as a technological university. The initiative aims to gain traction in the acceptance of the framework with the engineering education community by linking core and discipline-specific teaching and learning competencies with professional development activities most valued by engineering educators. Informed by three strands of literature: professional development in higher education; engineering education; and teaching and learning training provisions, the project begins with a survey of all those involved in teaching and learning in engineering across the three institutes. Based on engagement with key stakeholders, subsequent qualitative research informs the contextualization of the national framework for discipline-specific and institutional piloting. The paper concludes by exploring engineering educator perceptions of the national framework’s utility based on their engagement with the pilot process. Feedback from the pilot indicates that there is a significant gap between the professional development needs of engineering educators and the current professional development provision in teaching and learning.

Keywords: engineering education, pilot, professional development, teaching and learning

Procedia PDF Downloads 329

Authors: Amr Hamdy

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Background: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Many methods have been developed to decrease its rate. The aim of this study was to evaluate the applicability of a new non-pharmacologic maneuver in decreasing its rate. Methods: This case series study was conducted in one centre in Cairo, Egypt, from January-2010 to June-2013. 400 pregnant–women aged 18 years or more and candidate for normal labour; were enrolled to this study. High-risk subjects for PPH were excluded. After placental delivery, the new maneuver was done by sustained traction of the anterior and posterior lips of the cervix by two ovum forceps for duration of 90 seconds. The amount of blood loss was estimated by standardized visual estimation after removal of the forceps. All subjects were followed up for 6 hours. Results: The rate of PPH, defined as more than 500 ml, was 8 cases (2%) with 95% CI (0.63-3.37%). The rate of PPH was not affected by parity, gestational age, episiotomy or the presence of tears. PPH is more in cases with anemia (p 0.032). It occurred in all cases with uterine atony (p <0.001). The range of estimated blood loss was 550-600ml in cases with PPH and 150-450ml in cases without PPH. Severe PPH more than 1000 ml, did not occur. Conclusion: This pilot study introduced a novel maneuver that can be helpful in decreasing the rate of PPH and reducing the amount of post partum blood loss.Despite the low rate of PPH showed in this study, the need for conducting a randomized controlled study is at its highest level before further inclusion of such manoeuvre to be a part of the current medical practice and before considering it as an evident tool to decrease the burden of PPH.

Keywords: maternal mortality, new manoeuvre, post-partum haemorrhage, uterine atony

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Authors: Madhurima Poddar, Vinay Sharma, Shaikh M. Mobin, Rajneesh Misra

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Three 1,8-naphthalimide (NPI) substituted 4,4-difluoroboradiaza-s-indacene (BODIPY) dyads were synthesized via Pd-catalyzed Sonogashira cross-coupling reaction of ethynyl substituted NPI with the meso-, β- and α-halogenated BODIPYs, respectively. The photophysical and electrochemical data reveals considerable electronic communication between the BODIPY and NPI moieties. The electronic absorption spectrum reveals that the substitution of NPI at α position of BODIPY exhibit better electronic communication between the NPI and the BODIPY units. The electronic structures of all the dyads exhibit planar geometries which are in a good correlation with the structures obtained from single crystal X-ray diffraction. The crystal structures of the dyads exhibit interesting supramolecular interactions. The dyads show good cytocompatibility with the potential of multicolor live-cell imaging; making them excellent candidates for biological applications. The work provides an important strategy of screening the substitution pattern at different position of BODIPYs which will be useful for the design of BODIPY based organic molecules for various optoelectronic applications as well as bio-imaging.

Keywords: bio-imaging studies, cross-coupling, cyclic voltammetry, density functional calculations, fluorescence spectra, single crystal XRD, UV/Vis spectroscopy

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Authors: T. C. Ng, R. Radzi, T. K. Ng, H. C. Chen

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The analgesic effects of lidocaine-bupivacaine block in cats undergoing routine orchiectomy were determined in this controlled, randomized, and blinded study. Twelve cats were randomly assigned to two groups. Cats in local block group received subcutaneous infiltration of 1 mg/kg of 2% lidocaine and 1 mg/kg of 0.5% bupivacaine into the scrotal sac. Cats in control group received equivolume of saline. Both groups were induced with mixture of ketamine (15 mg/kg) and acepromazine (0.1 mg/kg) intramuscularly and maintained on sevoflurane via facemask. Non-invasive blood pressures (BP), heart (HR), and respiratory rate (RR) were measured intra-operatively at specific events. Post-operatively, all cats received meloxicam, 0.2 mg/kg subcutaneously. Pain scores were determined at 4, 8, and 24 hours postoperatively. Mechanical pressure thresholds (MPT) at the perineum and metatarsus were determined at 2, 4, 8, and 24 hours postoperatively. Intra-operatively, the BP and HR tended to be higher in the control group. The increment in HR peaked during traction and autoligation of the spermatic cord in the control group. There was no treatment difference in RR. Post-operatively, pain scores in the group given local blocks were lower than the control group at 4 hour post-operation. There was no treatment difference in the post-operative HR, RR, BP and MPT values. In conclusion, subcutaneous infiltration of lidocaine-bupivacaine into the scrotal sac before orchiectomy improved intra-operative hemodynamic stability and provided better analgesia up to 4 hours post-surgery.

Keywords: analgesia, bupivacaine, cat, lidocaine, local block, orchiectomy

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Authors: B. Neethu, Diptesh Das

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The present study investigates the performance of a semi-active controller using magneto-rheological dampers (MR) for seismic response reduction of a multi-span bridge. The application of structural control to the structures during earthquake excitation involves numerous challenges such as proper formulation and selection of the control strategy, mathematical modeling of the system, uncertainty in system parameters and noisy measurements. These problems, however, need to be tackled in order to design and develop controllers which will efficiently perform in such complex systems. A control algorithm, which can accommodate un-certainty and imprecision compared to all the other algorithms mentioned so far, due to its inherent robustness and ability to cope with the parameter uncertainties and imprecisions, is the sliding mode algorithm. A sliding mode control algorithm is adopted in the present study due to its inherent stability and distinguished robustness to system parameter variation and external disturbances. In general a semi-active control scheme using an MR damper requires two nested controllers: (i) an overall system controller, which derives the control force required to be applied to the structure and (ii) an MR damper voltage controller which determines the voltage required to be supplied to the damper in order to generate the desired control force. In the present study a sliding mode algorithm is used to determine the desired optimal force. The function of the voltage controller is to command the damper to produce the desired force. The clipped optimal algorithm is used to find the command voltage supplied to the MR damper which is regulated by a semi active control law based on sliding mode algorithm. The main objective of the study is to propose a robust semi active control which can effectively control the responses of the bridge under real earthquake ground motions. Lumped mass model of the bridge is developed and time history analysis is carried out by solving the governing equations of motion in the state space form. The effectiveness of MR dampers is studied by analytical simulations by subjecting the bridge to real earthquake records. In this regard, it may also be noted that the performance of controllers depends, to a great extent, on the characteristics of the input ground motions. Therefore, in order to study the robustness of the controller in the present study, the performance of the controllers have been investigated for fourteen different earthquake ground motion records. The earthquakes are chosen in such a way that all possible characteristic variations can be accommodated. Out of these fourteen earthquakes, seven are near-field and seven are far-field. Also, these earthquakes are divided into different frequency contents, viz, low-frequency, medium-frequency, and high-frequency earthquakes. The responses of the controlled bridge are compared with the responses of the corresponding uncontrolled bridge (i.e., the bridge without any control devices). The results of the numerical study show that the sliding mode based semi-active control strategy can substantially reduce the seismic responses of the bridge showing a stable and robust performance for all the earthquakes.

Keywords: bridge, semi active control, sliding mode control, MR damper

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Authors: Divyans Mahansaria

Abstract:

User authentication is an important security measure for protecting confidential data and systems. However, the vulnerability while authenticating into a system has significantly increased. Thus, necessary mechanisms must be deployed during the process of authenticating a user to safeguard him/her from the vulnerable attacks. The proposed solution implements a novel authentication mechanism to counter various forms of security breach attacks including phishing, Trojan horse, replay, key logging, Asterisk logging, shoulder surfing, brute force search and others. QR code (Quick Response Code) is a type of matrix barcode or two-dimensional barcode that can be used for storing URLs, text, images and other information. In the proposed solution, during each new authentication request, a QR code is dynamically generated and presented to the user. A piece of generic information is mapped to plurality of elements and stored within the QR code. The mapping of generic information with plurality of elements, randomizes in each new login, and thus the QR code generated for each new authentication request is for one-time use only. In order to authenticate into the system, the user needs to decode the QR code using any QR code decoding software. The QR code decoding software needs to be installed on handheld mobile devices such as smartphones, personal digital assistant (PDA), etc. On decoding the QR code, the user will be presented a mapping between the generic piece of information and plurality of elements using which the user needs to derive cipher secret information corresponding to his/her actual password. Now, in place of the actual password, the user will use this cipher secret information to authenticate into the system. The authentication terminal will receive the cipher secret information and use a validation engine that will decipher the cipher secret information. If the entered secret information is correct, the user will be provided access to the system. Usability study has been carried out on the proposed solution, and the new authentication mechanism was found to be easy to learn and adapt. Mathematical analysis of the time taken to carry out brute force attack on the proposed solution has been carried out. The result of mathematical analysis showed that the solution is almost completely resistant to brute force attack. Today’s standard methods for authentication are subject to a wide variety of software, hardware, and human attacks. The proposed scheme can be very useful in controlling the various types of authentication related attacks especially in a networked computer environment where the use of username and password for authentication is common.

Keywords: authentication, QR code, cipher / decipher text, one time password, secret information

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Authors: Dries Dulsster

Abstract:

This research we want to discuss the implications of the concept of ‘lalangue’ and illustrate its importance for lacanian psychoanalysis and its clinical practice. We will look at this concept through an in depth reading of Lacan’s later seminars, his lectures at the North-American universities and his study on James Joyce. We will illustrate the importance of this concept with a case study from a clinical practice. We will argue that the introduction of ‘lalangue’ has several theoretical and clinical implications that will radically change Lacans teachings. We will illustrate the distinction between language and lalangue. Language serves communication, but this is not the case with lalangue. We will claim that there is jouissance in language and will approach this by introducing the concept of ‘lalangue’. We will ask ourselves what the effect will be of this distinction and how we can use this in clinical practice. The concept of ‘lalangue’ will introduce a new way of thinking about the unconscious. It will force us to no longer view the unconscious as Symbolic, but as Imaginary or Real. Another implication will be the approach on the symptom, no longer approaching it as a formation of the unconscious. It will be renamed as ‘sinthome’, as function of the real. Last of all it will force us to rethink the lacanian interpretation and how we direct the treatment. The implications on a clinical level will be how we think about the lacanian interpretation and the direction of the treatment. We will no longer focus on language and meaning, but focus on jouissance and the ways in which the subject deals with this. We will illustrate this importance with a clinical case study. To summarize, the concept of lalangue forces us to radically rethink lacanian psychoanalysis, with major implications on a theoretical and clinical level. It introduces new concepts such as the real unconscious and the sinthome. It will also make us rethink the way we work as lacanian psychoanalysts.

Keywords: Lacan's later teaching, language, Lalangue, the unconscious

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Authors: Z. Miao, Y. Chu, Y. Zhang

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The unique cholesteric phase liquid crystals obtained by mixing nematic liquid crystals with chiral dopants have gained valuable applications in the display field for their selective reflection and circular dichroism properties. The periodic arrangement of the helical structure of cholesteric liquid crystals makes it possible to produce Bragg reflection of circularly polarized light irradiated perpendicularly to the liquid crystals and, therefore, to acquire semi- or fully reflective surfaces or films. If the polymer-liquid crystal composites are combined with polymeric monomers, commercialized reflective broadband films can be fabricated. In this study, the polymer-liquid crystal composites reflecting visible light region (wavelength centered at 550 nm) were studied to analyze the effects of AC electric field at different voltages and frequencies on the optical texture of the composites, as well as the effects of polymerization temperature and ultraviolet (UV) intensity on the polymerization reaction and reflection bandwidth. The optimal sample was finally obtained at 100Hz, 120V, 30℃, 1.00 mW/cm², which provides a research suggestion to solve the influencing factors of visible light reflection bandwidths.

Keywords: cholesteric liquid crystal, reflection bandwidths, negative dielectric anisotropy, planar texture

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Authors: Somya Ranjan Patro, Abhigna Bhatt, Arnab Banerjee

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Inertial amplifier has recently gained increasing attention as a new mechanism for vibration control of structures. Currently, theoretical investigations are undertaken by researchers to reveal its fundamentals and to understand its underline principles in altering the structural response of structures against dynamic loadings. This paper investigates experimental and analytical studies on the dynamic characteristics of hybrid beam inertial amplifier (HBIA). The analytical formulation of the HBIA has been derived by implementing the spectral element method and rigid body dynamics. This formulation gives the relation between dynamic force and the response of the structure in the frequency domain. Further, for validation of the proposed HBIA, the experiments have been performed. The experimental setup consists of a 3D printed HBIA of polylactic acid (PLA) material screwed at the base plate of the shaker system. Two numbers of accelerometers are used to study the response, one at the base plate of the shaker second one placed at the top of the inertial amplifier. A force transducer is also placed in between the base plate and the inertial amplifier to calculate the total amount of load transferred from the base plate to the inertial amplifier. The obtained time domain response from the accelerometers have been converted into the frequency domain using the Fast Fourier Transform (FFT) algorithm. The experimental transmittance values are successfully validated with the analytical results, providing us essential confidence in our proposed methodology.

Keywords: inertial amplifier, fast fourier transform, natural frequencies, polylactic acid, transmittance, vibration absorbers

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Authors: Irati Barandiaran, Xabier Velasco-Iza, Galder Kortaberria

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Hybrid inorganic/organic nanostructured materials based on block copolymers are of considerable interest in the field of Nanotechnology, taking into account that these nanocomposites combine the properties of polymer matrix and the unique properties of the added nanoparticles. The use of block copolymers as templates offers the opportunity to control the size and the distribution of inorganic nanoparticles. This research is focused on the surface modification of inorganic nanoparticles to reach a good interface between nanoparticles and polymer matrices which hinders the nanoparticle aggregation. The aim of this work is to obtain a good and selective dispersion of Fe3O4 magnetic nanoparticles into different types of block copolymers such us, poly(styrene-b-methyl methacrylate) (PS-b-PMMA), poly(styrene-b-ε-caprolactone) (PS-b-PCL) poly(isoprene-b-methyl methacrylate) (PI-b-PMMA) or poly(styrene-b-butadiene-b-methyl methacrylate) (SBM) by using different grafting strategies. Fe3O4 magnetic nanoparticles have been surface-modified with polymer or block copolymer brushes following different grafting methods (grafting to, grafting from and grafting through) to achieve a selective location of nanoparticles into desired domains of the block copolymers. Morphology of fabricated hybrid nanocomposites was studied by means of atomic force microscopy (AFM) and with the aim to reach well-ordered nanostructured composites different annealing methods were used. Additionally, nanoparticle amount has been also varied in order to investigate the effect of the nanoparticle content in the morphology of the block copolymer. Nowadays different characterization methods were using in order to investigate magnetic properties of nanometer-scale electronic devices. Particularly, two different techniques have been used with the aim of characterizing synthesized nanocomposites. First, magnetic force microscopy (MFM) was used to investigate qualitatively the magnetic properties taking into account that this technique allows distinguishing magnetic domains on the sample surface. On the other hand, magnetic characterization by vibrating sample magnetometer and superconducting quantum interference device. This technique demonstrated that magnetic properties of nanoparticles have been transferred to the nanocomposites, exhibiting superparamagnetic behavior similar to that of the maghemite nanoparticles at room temperature. Obtained advanced nanostructured materials could found possible applications in the field of dye-sensitized solar cells and electronic nanodevices.

Keywords: atomic force microscopy, block copolymers, grafting techniques, iron oxide nanoparticles

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Authors: Bohsiu Wu

Abstract:

Among serious crimes, child homicide is a rather rare event. However, the killing of children stirs up a special type of emotion in society that pales other criminal acts. This study examines the relevancy of three possible community-level explanations for child homicide: social deprivation, female empowerment, and social isolation. The social deprivation hypothesis posits that child homicide results from lack of resources in communities. The female empowerment hypothesis argues that a higher female status translates into a higher level of capability to prevent child homicide. Finally, the social isolation hypothesis regards child homicide as a result of lack of social connectivity. Child homicide data, aggregated by US postal ZIP codes in California from 1990 to 1999, were analyzed with a negative binomial regression. The results of the negative binomial analysis demonstrate that social deprivation is the most salient and consistent predictor among all other factors in explaining child homicide victimization at the ZIP-code level. Both social isolation and female labor force participation are weak predictors of child homicide victimization across communities. Further, results from the negative binomial regression show that it is the communities with a higher, not lower, degree of female labor force participation that are associated with a higher count of child homicide. It is possible that poor communities with a higher level of female employment have a lesser capacity to provide the necessary care and protection for the children. Policies aiming at reducing social deprivation and strengthening female empowerment possess the potential to reduce child homicide in the community.

Keywords: child homicide, deprivation, empowerment, isolation

Procedia PDF Downloads 194