Search results for: historic block
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1284

Search results for: historic block

1164 Fabrication of Nanostructured Arrays Using Si-Containing Block Copolymer and Dually Responsive Photoresist

Authors: Kyoungok Jung, Chang Hong Bak, Gyeong Cheon Jo, Jin-Baek Kim

Abstract:

Nanostructured arrays have drawn extensive attention because of their unique properties resulting from nanoscale features. However, it is difficult to achieve uniform and freestanding 1D nanostrcutures over a large area. Here, a simple and novel method was developed for fabrication of universal nanoporous templates for high-density nanostructure arrays, by combining self-assembly of a Si-containing block copolymer with a bilayer lithography system. We introduced a dually responsive photoresist bottom layer into which the nanopatterns of block copolymer are transferred by oxygen reactive ion etching. Because the dually responsive layer becomes cross-linked by heating, it can be used as a hard template during the etching process. It becomes soluble again by chain scission upon exposure to light. Therefore, it can be easily removed by the lift-off process. The template was applicable to the various conducting substrates due to the compatibility of the photoresist with a wide range of substrates and was used in electrodeposition for well-aligned and high-density inorganic and organic nanoarrays. We successfully obtained vertically aligned and highly ordered gold nanorods and polypyrrole dots on the substrate without aggregation, and these arrays did not collapse after removing the dually responsive templates by the simple lift-off process.

Keywords: block copolymer, dually responsive, nanostructure, photoresist

Procedia PDF Downloads 238
1163 Speed Control of Brushless DC Motor Using PI Controller in MATLAB Simulink

Authors: Do Chi Thanh, Dang Ngoc Huy

Abstract:

Nowadays, there are more and more variable speed drive systems in small-scale and large-scale applications such as the electric vehicle industry, household appliances, medical equipment, and other industrial fields led to the development of BLDC (Brushless DC) motors. BLDC drive has many advantages, such as higher efficiency, better speed torque characteristics, high power density, and low maintenance cost compared to other conventional motors. Most BLDC motors use a proportional-integral (PI) controller and a pulse width modulation (PWM) scheme for speed control. This article describes the simulation model of BLDC motor drive control with the help of MATLAB - SIMULINK simulation software. The built simulation model includes a BLDC motor dynamic block, Hall sensor signal generation block, inverter converter block, and PI controller.

Keywords: brushless DC motor, BLDC, six-step inverter, PI speed

Procedia PDF Downloads 45
1162 On the Optimality of Blocked Main Effects Plans

Authors: Rita SahaRay, Ganesh Dutta

Abstract:

In this article, experimental situations are considered where a main effects plan is to be used to study m two-level factors using n runs which are partitioned into b blocks, not necessarily of same size. Assuming the block sizes to be even for all blocks, for the case n ≡ 2 (mod 4), optimal designs are obtained with respect to type 1 and type 2 optimality criteria in the class of designs providing estimation of all main effects orthogonal to the block effects. In practice, such orthogonal estimation of main effects is often a desirable condition. In the wider class of all available m two level even sized blocked main effects plans, where the factors do not occur at high and low levels equally often in each block, E-optimal designs are also characterized. Simple construction methods based on Hadamard matrices and Kronecker product for these optimal designs are presented.

Keywords: design matrix, Hadamard matrix, Kronecker product, type 1 criteria, type 2 criteria

Procedia PDF Downloads 341
1161 Conduction System Disease and Atrioventricular Block in Victims of COVID-19

Authors: Shirin Sarejloo

Abstract:

Background: Electrophysiological-related manifestation of COVID-19 is a matter of debate in the literature nowadays. A wide spectrum of arrhythmias was observed among patients who have been infected with COVID-19. Objectives: This study discussed the prevalence of arrhythmias and conduction system disease in patients with COVID-19. Method: In this retrospective study, demographic and electrocardiographic data of 432 expired COVID-19 patients who had been admitted to Faghihi Hospital of Shiraz University of Medical Sciences from August2020 until December 2020 were reviewed. Results: Atrioventricular nodal block (AVB) was found in 40(9.3%) patients. Furthermore, 28(6.5%) of them suffered from the first degree of AVB, and 12(2.8%) suffered from complete heart block (CHB). Among 189 cases (59.0%), ST-T changes agreed with myocardial infarction or localized myocarditis. Findings of myocardial injury, including fragmented QRS and prolonged QTc were observed among 91 (21.1%) and 28 (6.5%), respectively. In victims of COVID-19, conduction disease was not related to any comorbidities. Fragmented QRS, axis deviation, presence of S1Q3T3, and poor R wave progression were significantly related to conduction system abnormalities in victims of COVID-19 (P-value > 0.05). Conclusion: Our findings can serve in future studies that aim to develop a risk stratification method for susceptible COVID-19 patients. The myocardial injury appears to role significantly in COVID-19 morbidity and mortality. Consequently, we recommend health policymakers consider separate catheterization laboratories that provide service only to COVID-19 patients.

Keywords: COVID-19, conduction system, ECG, atrioventricular block

Procedia PDF Downloads 66
1160 Supramolecular Approach towards Novel Applications: Battery, Band Gap and Gas Separation

Authors: Sudhakara Naidu Neppalli, Tejas S. Bhosale

Abstract:

It is well known that the block copolymer (BCP) can form a complex molecule, through non-covalent bonds such as hydrogen bond, ionic bond and co-ordination bond, with low molecular weight compound as well as with macromolecules, which provide vast applications, includes the alteration of morphology and properties of polymers. Hence we covered the research that, the importance of non-covalent bonds in increasing the non-favourable segmental interactions of the blocks was well examined by attaching and detaching the bonds between the BCP and additive. We also monitored the phase transition of block copolymer and effective interaction parameter (χeff) for Li-doped polymers using small angle x-ray scattering and transmission electron microscopy. The effective interaction parameter (χeff) between two block components was evaluated using Leibler theory based on the incompressible random phase approximation (RPA) for ionized BCP in a disordered state. Furthermore, conductivity experiments demonstrate that the ionic conductivity in the samples quenched from the different structures is morphology-independent, while it increases with increasing ion salt concentration. Morphological transitions, interaction parameter, and thermal stability also examined in quarternized block copolymer. D-spacing was used to estimate effective interaction parameter (χeff) of block components in weak and strong segregation regimes of ordered phase. Metal-containing polymer has been the topic of great attention in recent years due to their wide range of potential application. Similarly, metal- ligand complex is used as a supramolecular linker between the polymers giving rise to a ‘Metallo-Supramolecule assembly. More precisely, functionalized polymer end capped with 2, 2’:6’, 2”- terpyridine ligand can be selectively complexed with wide range of transition metal ions and then subsequently attached to other terpyridine terminated polymer block. In compare to other supramolecular assembly, BCP involved metallo-supramolecule assembly offers vast applications such as optical activity, electrical conductivity, luminescence and photo refractivity.

Keywords: band gap, block copolymer, conductivity, interaction parameter, phase transition

Procedia PDF Downloads 140
1159 Performance Comparison of Space-Time Block and Trellis Codes under Rayleigh Channels

Authors: Jing Qingfeng, Wu Jiajia

Abstract:

Due to the crowded orbits and shortage of frequency resources, utilizing of MIMO technology to improve spectrum efficiency and increase the capacity has become a necessary trend of broadband satellite communication. We analyze the main influenced factors and compare the BER performance of space-time block code (STBC) scheme and space-time trellis code (STTC) scheme. This paper emphatically studies the bit error rate (BER) performance of STTC and STBC under Rayleigh channel. The main emphasis is placed on the effects of the factors, such as terminal environment and elevation angles, on the BER performance of STBC and STTC schemes. Simulation results indicate that performance of STTC under Rayleigh channel is obviously improved with the increasing of transmitting and receiving antennas numbers, but the encoder state has little impact on the performance. Under Rayleigh channel, performance of Alamouti code is better than that of STTC.

Keywords: MIMO, space time block code (STBC), space time trellis code (STTC), Rayleigh channel

Procedia PDF Downloads 323
1158 Immersive Block Scheduling in Higher Education: A Case Study in Curriculum Reform and Increased Student Success

Authors: Thomas Roche, Erica Wilson, Elizabeth Goode

Abstract:

Universities across the globe are considering how to effect meaningful change in their higher education (HE) delivery in the face of increasingly diverse student cohorts and shifting student learning preferences. This paper reports on a descriptive case study of whole-of-institution curriculum reform at one regional Australian university, where more traditional 13-week semesters were replaced with a 6-week immersive block model drawing on active learning pedagogy. Based on a synthesis of literature in best practice HE pedagogy and principles, the case study draws on student performance data and senior management staff interviews (N = 5) to outline the key changes necessary for successful HE transformation to deliver increased student pass rates and retention. The findings from this case study indicate that an institutional transformation to an immersive block model requires both a considered change in institutional policy and process as well as the appropriate resourcing of roles, governance committees, technical solutions, and, importantly, communities of practice. Implications for practice at higher education institutions considering reforming their curriculum model are also discussed.

Keywords: student retention, immersive scheduling, block model, curriculum reform, active learning, higher education pedagogy, higher education policy

Procedia PDF Downloads 35
1157 Examples from a Traditional Sismo-Resistant Architecture

Authors: Amira Zatir, Abderahmane Mokhtari, Amina Foufa, Sara Zatir

Abstract:

It exists in several regions in the world, of numerous historic monuments, buildings and housing environment, built in traditional ways which survive for earthquakes, even in zones where the seismic risk is particularly raised. These constructions, stemming from vernacular architecture, allow, through their resistances in the time earthquakes, to identify the various sismo-resistant "local" techniques. Through the examples and the experiences presented, the remark which can be made, is that in the traditional built, two major principles in a way opposite, govern the constructions in earthquake-resistant. It is about the very big flexibility, whom answer very light constructions, like the Japanese wooden constructions, Turkish and even Chinese; that of the very big rigidity to which correspond constructions in masonry in particular stone, more or less heavy and massive, which we meet in particular in the Mediterranean Basin, and in the historic sanctuary of Machu Pacchu. In it sensible and well-reflected techniques of construction are added, of which the use of the humble materials such as the earth and the adobe. The ancient communities were able to face the seismic risks, thanks to them know-how reflected in their intelligently designed constructions, testifying of a local seismic culture.

Keywords: earthquake, architecture, traditional, construction, resistance

Procedia PDF Downloads 389
1156 Comparative Study of Analgesic Efficacy of Ultrasound Guided Femoral Nerve Block Versus Intravenous Fentanyl Injection in Fracture Femur Patients at Emergency Department

Authors: Asmaa Hamdy, Israa Nassar, Tarek Aly

Abstract:

Introduction: Femoral fractures are the most common presentation in the Emergency Department (ED), and they can present as isolated injuries or as part of a polytrauma situation. To provide optimum pain management care to these patients, practitioners must be well prepared and current with utilizing modern evidence-based knowledge and practices. Management of pain associated with fracture femur in the emergency department has a critical role in the satisfaction of patients and preventing further complications. This study aimed to evaluate the analgesic efficacy of ultrasound-guided femoral nerve block compared with intravenous fentanyl in fractures of the femur in patients presented to the Emergency Department. Patients and Methods: Fifty patients with femur fractures were divided into two groups: Group A: In this group (twenty-five patients) were given intravenous fentanyl 2 micro-grams/kg and re-assessed for pain by Visual Analogue Score (VAS). Group B: In this group (twenty-five patients) underwent ultrasonography-guided femoral nerve block and were re-assessed for pain by VAS. Results: VAS score on the movement of the fractured limb between group A and group B at a 10-minute post-intervention period shows P= 0.043, and hence the difference is significant. VAS score on the movement of the fractured limb between group A and group B during a 10-minute post-intervention period showed a significant difference. Seventeen patients in group A had major PID with a percentage of 63% VS 10 patients in group B with a percentage of 37%. conclusion: both femoral nerve block and intravenous fentanyl are effective in relieving pain in patients with femur fractures. But femoral nerve block provides better and more intense analgesia and major pain intensity difference in less time. Moreover, the use of FNB had fewer side effects and more Hemodynamics stability compared to opioids.

Keywords: femur fracture, nerve block, fentanyl, ultrasound guided

Procedia PDF Downloads 72
1155 Compressed Sensing of Fetal Electrocardiogram Signals Based on Joint Block Multi-Orthogonal Least Squares Algorithm

Authors: Xiang Jianhong, Wang Cong, Wang Linyu

Abstract:

With the rise of medical IoT technologies, Wireless body area networks (WBANs) can collect fetal electrocardiogram (FECG) signals to support telemedicine analysis. The compressed sensing (CS)-based WBANs system can avoid the sampling of a large amount of redundant information and reduce the complexity and computing time of data processing, but the existing algorithms have poor signal compression and reconstruction performance. In this paper, a Joint block multi-orthogonal least squares (JBMOLS) algorithm is proposed. We apply the FECG signal to the Joint block sparse model (JBSM), and a comparative study of sparse transformation and measurement matrices is carried out. A FECG signal compression transmission mode based on Rbio5.5 wavelet, Bernoulli measurement matrix, and JBMOLS algorithm is proposed to improve the compression and reconstruction performance of FECG signal by CS-based WBANs. Experimental results show that the compression ratio (CR) required for accurate reconstruction of this transmission mode is increased by nearly 10%, and the runtime is saved by about 30%.

Keywords: telemedicine, fetal ECG, compressed sensing, joint sparse reconstruction, block sparse signal

Procedia PDF Downloads 99
1154 Identification of Tangible and Intangible Heritage and Preparation of Conservation Proposal for the Historic City of Karanja Laad

Authors: Prachi Buche Marathe

Abstract:

Karanja Laad is a city located in the Vidarbha region in the state of Maharashtra, India. It has a huge amount of tangible and intangible heritage in the form of monuments, precincts, a group of structures, festivals and procession route, which is neglected and lost with time. Three different religions Hinduism, Islam and Jainism along with associations of being a birthplace of Swami Nrusinha Saraswati, an exponent of Datta Sampradaya sect and the British colonial layer have shaped the culture and society of the place over the period. The architecture of the town Karanja Laad has enhanced its unique historic and cultural value with a combination of all these historic layers. Karanja Laad is also a traditional trading historic town with unique hybrid architectural style and has a good potential for developing as a tourist place along with the present image of a pilgrim destination of Datta Sampradaya. The aim of the research is to prepare a conservation proposal for the historic town along with the management framework. Objectives of the research are to study the evolution of Karanja town, to identify the cultural resources along with issues of the historic core of the city, to understand Datta sampradaya, and contribution of Saint Nrusinha Saraswati in the religious sect and his association as an important personality with Karanja. The methodology of the research is site visits to the Karanja city, making field surveys for documentation and discussions and questionnaires with the residents to establish heritage and identify potential and issues within the historic core thereby establishing a case for conservation. Field surveys are conducted for town level study of land use, open spaces, occupancy, ownership, traditional commodity and community, infrastructure, streetscapes, and precinct activities during the festival and non-festival period. Building level study includes establishing various typologies like residential, institutional commercial, religious, and traditional infrastructure from the mythological references like waterbodies (kund), lake and wells. One of the main issues is that the loss of the traditional footprint as well as the traditional open spaces which are getting lost due to the new illegal encroachments and lack of guidelines for the new additions to conserve the original fabric of the structures. Traditional commodities are getting lost since there is no promotion of these skills like pottery and painting. Lavish bungalows like Kannava mansion, main temple Wada (birthplace of the saint) have a huge potential to be developed as a museum by adaptive re-use which will, in turn, attract many visitors during festivals which will boost the economy. Festival procession routes can be identified and a heritage walk can be developed so as to highlight the traditional features of the town. Overall study has resulted in establishing a heritage map with 137 heritage structures identified as potential. Conservation proposal is worked out on the town level, precinct level and building level with interventions such as developing construction guidelines for further development and establishing a heritage cell consisting architects and engineers for the upliftment of the existing rich heritage of the Karanja city.

Keywords: built heritage, conservation, Datta Sampradaya, Karanja Laad, Swami Nrusinha Saraswati, procession route

Procedia PDF Downloads 130
1153 A Prospective Study on Alkali Activated Bottom Ash-GGBS Blend in Paver Blocks

Authors: V. Revathi, J. Thaarrini, M. Venkob Rao

Abstract:

This paper presents a study on use of alkali activated bottom ash (BA) and ground granulated blast furnace slag (GGBS) blend in paver blocks. A preliminary effort on alkali-activated bottom ash, blast furnace slag based geopolymer (BA-GGBS-GP) mortar with river sand was carried out to identify the suitable mix for paver block. Several mixes were proposed based on the combination of BA-GGBS. The percentage ratio of BA:GGBS was selected as 100:0, 75:25, 50:50, 25:75 and 0:100 for the source material. Sodium based alkaline activators were used for activation. The molarity of NaOH was considered as 8M. The molar ratio of SiO2 to Na2O was varied from 1 to 4. Two curing mode such as ambient and steam curing 60°C for 24 hours were selected. The properties of paver block such as compressive strength split tensile strength, flexural strength and water absorption were evaluated as per IS15658:2006. Based on the preliminary study on BA-GGBS-GP mortar, the combinations of 25% BA with 75% GGBS mix for M30 and 75% BA with 25% GGBS mix for M35 grade were identified for paver block. Test results shows that the combination of BA-GGBS geopolymer paver blocks attained remarkable compressive strength under steam curing as well as in ambient mode at 3 days. It is noteworthy to know BA-GGBS-GP has promising future in the construction industry.

Keywords: bottom ash, GGBS, alkali activation, paver block

Procedia PDF Downloads 329
1152 The UNESCO Management Plan for Urban Heritage Sites: A Critical Review of Olinda and Porto, in Brazil and Portugal

Authors: Francine Morales Tavares, Jose Alberto Rio Fernandes

Abstract:

The expanding concept of Heritage and the increased relevance of how heritage places relate to their surroundings is associated with an important shift in public heritage policies and how they consider the development of cities and communities, with an increasingly relevant role of management. Within the current discussions, management plans, mandatory since the year 2005 in areas classified by UNESCO as World Heritage, it is a tool for the reconciliation of cultural heritage demands with the needs of multiple users of a certain area, being especially critical in the case of urban areas with intense touristic pressure. Considering the transformations of the heritage policy management model, this paper discusses the practices on the integration of cultural heritage in urban policies through indicators which were selected from resource manual 'Managing Cultural World Heritage (2013)' and analyzed two case studies: The Management Plan of the Historic Centre of Porto (Portugal) and The Management Plan for the Historic Site of Olinda (Brazil). The empirical evidence concluded that for the historic centre of Porto the increase of tourism is the main aim driver in the management plan, with positive and negative aspects on the heritage management point of view, unlike Olinda, where the plan for the development of local urban policies was identified as essential. Plans also differ in form, content and process but coincide on being unaligned with committed local political leaders’ agendas, with the consequent misunderstandings between theory and practice, planning and management, and critically missing in the field integration of urban policies. Therefore, more debate about management plans, more efficient tools and also, appropriate methodologies to correlate cultural heritage and urban public policy are still lacking.

Keywords: world heritage, management plan, planning, urban policies

Procedia PDF Downloads 124
1151 Architecture of Contemporary Museums Located in the Historic Center of Cracow: One City, One Architect, Three Projects

Authors: A. Brach

Abstract:

The architecture of modern museums in the historical center should refer to a place in a cultural, historical, urban and architectural sense, using adequate and contemporary forms of architecture. The research and architectural analysis of selected museums in Cracow were conducted to illustrate which elements were decisive for the choice of architectural form. The evaluation of selected objects took into the consideration the following aspects: continuation of the historical form, contemporary form referring to the place, the individual-author form omitting the cultural aspect of the place. The presented projects showed the compromise as positive solutions rejecting both the direct imitation or 'historical continuation' as well as an individual form focused on an abstract form. In order to carry out research and confirm the thesis, three designs of Assoc. Prof. Eng. Arch. Krzysztof Ingarden in the historic city of Cracow were selected. Despite being constructed in one city, the neighborhood and cultural contexts of the locations are completely different. The neighborhood of the historical Royal Road and gothic church with unique decorations from the Polish Art Nouveau, artist Stanislaw Wyspianski (Wyspianski Pavilion), the bend of the Vistula hosting the Japanese culture (Museum of Japanese Art and Technology Manggha) and finally the old area of a horse riding school from the Austrian Empire times (Malopolska Garden of Art). All three buildings are dedicated to the culture of Japan, Polish artist Stanislaw Wyspianski, contemporary achievements and the promotion of art at its widest sense. Important fact for this research is that there is one author of all presented projects.

Keywords: adaptation of existing buildings, architecture in cracow, modern architecture, museums located in historic center

Procedia PDF Downloads 138
1150 Protection and Renewal Strategies of Historical Blocks from the Perspective of “Staged Authenticity”

Authors: Xu Yingqiang, Wang Zhongde

Abstract:

In the age of stock development, the contradiction between the protection and development of historical blocks in China has become increasingly prominent, among which how to reconcile the contradiction between tourists and local residents and inherit urban culture is an important proposition. Based on this, this paper introduces the theory of " staged authenticity ", combs its development process and related research progress, constructs an analysis and research model of historical blocks based on the theory of " staged authenticity ", and puts forward the protection and renewal strategy of historical blocks from the perspective of " staged authenticity ", which provides theoretical basis for coordinating the tourism-residence contradiction and protecting urban characteristics in the protection and renewal of historical blocks. The research holds that we should pay attention to the important value of "curtain" space, rationally arrange "curtain" and divide "foreground" and "background"; extract "props" from real history and culture to restore the authenticity of "stage" scenes; clever arrangement of tour streamline, so that all scenes are connected in series rhythmically; make the "actors" perform interactively in the "foreground" space, so as to enhance the "audience" sense of scene substitution.

Keywords: historic block, protection and renewal, staged authenticity, curtain

Procedia PDF Downloads 38
1149 Numerical Modeling of a Molten Salt Power Tower Configuration Adaptable for Harsh Winter Climate

Authors: Huiqiang Yang, Domingo Santana

Abstract:

This paper proposes a novel configuration which introduces a natural draft dry cooling tower system in a molten salt power tower. A three-dimensional numerical modeling was developed based on the novel configuration. A plan of building 20 new concentrating solar power plants has been announced by Chinese government in September 2016, and among these 20 new plants, most of them are located in regions with long winter and harsh winter climate. The innovative configuration proposed includes an external receiver concrete tower at the center, a natural draft dry cooling tower which is surrounding the external receiver concrete tower and whose shell is fixed on the external receiver concrete tower, and a power block (including a steam generation system, a steam turbine system and hot/cold molten salt tanks, and water treatment systems) is covered by the roof of the natural draft dry cooling tower. Heat exchanger bundles are vertically installed at the furthest edge of the power block. In such a way, all power block equipment operates under suitable environmental conditions through whole year operation. The monthly performance of the novel configuration is simulated as compared to a standard one. The results show that the novel configuration is much more efficient in each separate month in a typical meteorological year. Moreover, all systems inside the power block have less thermal losses at low ambient temperatures, especially in harsh winter climate. It is also worthwhile mentioning that a photovoltaic power plant can be installed on the roof of the cooling tower to reduce the parasites of the molten salt power tower.

Keywords: molten salt power tower, natural draft dry cooling, commercial scale, power block, harsh winter climate

Procedia PDF Downloads 315
1148 Poly(Trimethylene Carbonate)/Poly(ε-Caprolactone) Phase-Separated Triblock Copolymers with Advanced Properties

Authors: Nikola Toshikj, Michel Ramonda, Sylvain Catrouillet, Jean-Jacques Robin, Sebastien Blanquer

Abstract:

Biodegradable and biocompatible block copolymers have risen as the golden materials in both medical and environmental applications. Moreover, if their architecture is of controlled manner, higher applications can be foreseen. In the meantime, organocatalytic ROP has been promoted as more rapid and immaculate route, compared to the traditional organometallic catalysis, towards efficient synthesis of block copolymer architectures. Therefore, herein we report novel organocatalytic pathway with guanidine molecules (TBD) for supported synthesis of trimethylene carbonate initiated by poly(caprolactone) as pre-polymer. Pristine PTMC-b-PCL-b-PTMC block copolymer structure, without any residual products and clear desired block proportions, was achieved under 1.5 hours at room temperature and verified by NMR spectroscopies and size-exclusion chromatography. Besides, when elaborating block copolymer films, further stability and amelioration of mechanical properties can be achieved via additional reticulation step of precedently methacrylated block copolymers. Subsequently, stimulated by the insufficient studies on the phase-separation/crystallinity relationship in these semi-crystalline block copolymer systems, their intrinsic thermal and morphology properties were investigated by differential scanning calorimetry and atomic force microscopy. Firstly, by DSC measurements, the block copolymers with χABN values superior to 20 presented two distinct glass transition temperatures, close to the ones of the respecting homopolymers, demonstrating an initial indication of a phase-separated system. In the interim, the existence of the crystalline phase was supported by the presence of melting temperature. As expected, the crystallinity driven phase-separated morphology predominated in the AFM analysis of the block copolymers. Neither crosslinking at melted state, hence creation of a dense polymer network, disturbed the crystallinity phenomena. However, the later revealed as sensible to rapid liquid nitrogen quenching directly from the melted state. Therefore, AFM analysis of liquid nitrogen quenched and crosslinked block copolymer films demonstrated a thermodynamically driven phase-separation clearly predominating over the originally crystalline one. These AFM films remained stable with their morphology unchanged even after 4 months at room temperature. However, as demonstrated by DSC analysis once rising the temperature above the melting temperature of the PCL block, neither the crosslinking nor the liquid nitrogen quenching shattered the semi-crystalline network, while the access to thermodynamical phase-separated structures was possible for temperatures under the poly (caprolactone) melting point. Precisely this coexistence of dual crosslinked/crystalline networks in the same copolymer structure allowed us to establish, for the first time, the shape-memory properties in such materials, as verified by thermomechanical analysis. Moreover, the response temperature to the material original shape depended on the block copolymer emplacement, hence PTMC or PCL as end-block. Therefore, it has been possible to reach a block copolymer with transition temperature around 40°C thus opening potential real-life medical applications. In conclusion, the initial study of phase-separation/crystallinity relationship in PTMC-b-PCL-b-PTMC block copolymers lead to the discovery of novel shape memory materials with superior properties, widely demanded in modern-life applications.

Keywords: biodegradable block copolymers, organocatalytic ROP, self-assembly, shape-memory

Procedia PDF Downloads 105
1147 Fast Bayesian Inference of Multivariate Block-Nearest Neighbor Gaussian Process (NNGP) Models for Large Data

Authors: Carlos Gonzales, Zaida Quiroz, Marcos Prates

Abstract:

Several spatial variables collected at the same location that share a common spatial distribution can be modeled simultaneously through a multivariate geostatistical model that takes into account the correlation between these variables and the spatial autocorrelation. The main goal of this model is to perform spatial prediction of these variables in the region of study. Here we focus on a geostatistical multivariate formulation that relies on sharing common spatial random effect terms. In particular, the first response variable can be modeled by a mean that incorporates a shared random spatial effect, while the other response variables depend on this shared spatial term, in addition to specific random spatial effects. Each spatial random effect is defined through a Gaussian process with a valid covariance function, but in order to improve the computational efficiency when the data are large, each Gaussian process is approximated to a Gaussian random Markov field (GRMF), specifically to the block nearest neighbor Gaussian process (Block-NNGP). This approach involves dividing the spatial domain into several dependent blocks under certain constraints, where the cross blocks allow capturing the spatial dependence on a large scale, while each individual block captures the spatial dependence on a smaller scale. The multivariate geostatistical model belongs to the class of Latent Gaussian Models; thus, to achieve fast Bayesian inference, it is used the integrated nested Laplace approximation (INLA) method. The good performance of the proposed model is shown through simulations and applications for massive data.

Keywords: Block-NNGP, geostatistics, gaussian process, GRMF, INLA, multivariate models.

Procedia PDF Downloads 66
1146 Effect of Gravity on the Controlled Cooling of a Steel Block by Impinging Water Jets

Authors: E.K.K. Agyeman, P. Mousseau, A. Sarda, D. Edelin

Abstract:

The uniform and controlled cooling of hot metals by the circulation of water in canals remains a challenge due to the phase change of the water and the high heat fluxes associated with the phase change. This is because, during the cooling process, the phases are not uniformly distributed along the canals with the liquid phase dominating at the entrances of the canals and the gaseous phase dominating towards the exits. The difference in thermal properties between both phases leads to a heterogeneous temperature distribution in the part being cooled. Slowing down the cooling process is also a challenge due to the high heat fluxes associated with the phase change of water. This study investigates the use of multiple water jets for the controlled and homogenous cooling of hot metal parts and the effect of gravity on the effectiveness of the cooling process with a potential application in the cooling of composite forming moulds. A hole is bored at the centre of a steel block along its length. The jets are generated from the holes of a perforated steel pipe which is placed along the centre of the hole bored in the steel block. The evolution of the temperature with respect to time on the external surface of the steel block is measured simultaneously by thermocouples and an infrared camera. Different jet positions are tested in order to identify the jet placement configuration that ensures the most homogenous cooling of the block while the cooling speed is controlled by an intermittent impingement of the jets. In order to study the effect of gravity on the cooling process, a scenario where the jets are oriented in the opposite direction to that of gravity is compared to one where the jets are aligned in the same direction as gravity. It’s observed that orienting the jets in the direction of gravity reduces the effectiveness of the cooling process on the face of the block facing the impinging jets. This is due to the formation of a deeper pool of water due to the effect gravity and of the curved surface of the canal. This deeper pool of water influences the boiling regime characterized by a slower bubble evacuation when compared to the scenario where the jets are opposed to gravity.

Keywords: cooling speed, gravity, homogenous cooling, jet impingement

Procedia PDF Downloads 105
1145 The Addition of Opioids to Bupivacaine in Bilateral Infraorbital Nerve Block for Postoperative Pain Relief in Paediatric Patients for Cleft Lip Repair-Comparative Effects of Pethidine and Fentanyl: A Prospective Randomized Double Blind Study

Authors: Mrudula Kudtarkar, Rajesh Mane

Abstract:

Introduction: Cleft lip repair is one of the common surgeries performed in India and the usual method used for post-operative analgesia is perioperative opioids and NSAIDs. There has been an increase in use of regional techniques and Opioids are the common adjuvants but their efficacy and safety have not been studied extensively in children. Aim: A prospective, randomized, double-blind study was done to compare the efficacy, duration and safety of intraoral infraorbital nerve block on post-operative pain relief using bupivacaine alone or in combination with fentanyl or pethidine in paediatric cleft lip repair. Methodology: 45 children between the age group 5 – 60 months undergoing cleft lip surgery randomly allocated into 3 groups of 15 each received bilateral intraoral infraorbital nerve block with 0.75ml of solution. Group B received 0.25% bupivacaine; group P received 0.25% bupivacaine with 0.25mg/kg pethidine, group F received 0.25% bupivacaine with 0.25microgm/kg fentanyl. Sedation after recovery, post-operative pain intensity and duration of post-operative analgesia were assessed using Modified Hannallah Pain Score. Results: The mean duration of analgesia was 17.8 hrs in Group B, 23.53 hrs in Group F and 35.13 hrs in Group P. There was statistically significant difference between the means of the three groups- ANOVA (p < 0.05). Conclusion: Thus we conclude that addition of fentanyl or pethidine to bupivacaine for Bilateral Intraoral Infraorbital Nerve Block prolong the duration of analgesia with no complications and can be used safely in paediatric patients.

Keywords: cleft lip, infraorbital block, NSAIDS, Opiods

Procedia PDF Downloads 215
1144 Determination of Mercury in Gold Ores by CVAAS Method

Authors: Ratna Siti Khodijah, Mirzam Abdurrachman

Abstract:

Gold is recovered from gold ores. Within the ores, there are not only gold but also several types of precious metals. Copper, silver, and platinum group elements (ruthenium, rhodium, palladium, rhenium, osmium, and iridium) are metals commonly found in the ores. These metals combine to form an ore because they have the same properties. It is due to their position in periodic-system-of-elements are near to gold. However, the presence of mercury in every gold ore has not been mentioned, even though it is located right next to gold in the periodic-system-of-elements and they are located in the same block, d-block. Thus, it is possible that mercury is contained in the ores. Moreover, the elements of the same group with mercury—zinc and cadmium—sometimes can be found in the ores. It is suspected that mercury can not be detected because the processing of gold ores usually using fire assay method. Before the ores melting, mercury would evaporate because it has the lowest boiling point of all precious metal in the ores. Therefore, it suggested doing research on the presence of mercury in gold ores by CVAAS method. The results of this study would obtain the amount of mercury in gold ores that should be purified. So it can be produced economically if possible.

Keywords: boiling point, d-block, fire assay, precious metal

Procedia PDF Downloads 310
1143 Different Motor Inhibition Processes in Action Selection Stage: A Study with Spatial Stroop Paradigm

Authors: German Galvez-Garcia, Javier Albayay, Javiera Peña, Marta Lavin, George A. Michael

Abstract:

The aim of this research was to investigate whether the selection of the actions needs different inhibition processes during the response selection stage. In Experiment 1, we compared the magnitude of the Spatial Stroop effect, which occurs in response selection stage, in two motor actions (lifting vs reaching) when the participants performed both actions in the same block or in different blocks (mixed block vs. pure blocks).Within pure blocks, we obtained faster latencies when lifting actions were performed, but no differences in the magnitude of the Spatial Stroop effect were observed. Within mixed block, we obtained faster latencies as well as bigger-magnitude for Spatial Stroop effect when reaching actions were performed. We concluded that when no action selection is required (the pure blocks condition), inhibition works as a unitary system, whereas in the mixed block condition, where action selection is required, different inhibitory processes take place within a common processing stage. In Experiment 2, we investigated this common processing stage in depth by limiting participants’ available resources, requiring them to engage in a concurrent auditory task within a mixed block condition. The Spatial Stroop effect interacted with Movement as it did in Experiment 1, but it did not significantly interact with available resources (Auditory task x Spatial Stroop effect x Movement interaction). Thus, we concluded that available resources are distributed equally to both inhibition processes; this reinforces the likelihood of there being a common processing stage in which the different inhibitory processes take place.

Keywords: inhibition process, motor processes, selective inhibition, dual task

Procedia PDF Downloads 359
1142 First Order Filter Based Current-Mode Sinusoidal Oscillators Using Current Differencing Transconductance Amplifiers (CDTAs)

Authors: S. Summart, C. Saetiaw, T. Thosdeekoraphat, C. Thongsopa

Abstract:

This article presents new current-mode oscillator circuits using CDTAs which is designed from block diagram. The proposed circuits consist of two CDTAs and two grounded capacitors. The condition of oscillation and the frequency of oscillation can be adjusted by electronic method. The circuits have high output impedance and use only grounded capacitors without any external resistor which is very appropriate to future development into an integrated circuit. The results of PSPICE simulation program are corresponding to the theoretical analysis.

Keywords: current-mode, quadrature oscillator, block diagram, CDTA

Procedia PDF Downloads 427
1141 NUX: A Lightweight Block Cipher for Security at Wireless Sensor Node Level

Authors: Gaurav Bansod, Swapnil Sutar, Abhijit Patil, Jagdish Patil

Abstract:

This paper proposes an ultra-lightweight cipher NUX. NUX is a generalized Feistel network. It supports 128/80 bit key length and block length of 64 bit. For 128 bit key length, NUX needs only 1022 GEs which is less as compared to all existing cipher design. NUX design results into less footprint area and minimal memory size. This paper presents security analysis of NUX cipher design which shows cipher’s resistance against basic attacks like Linear and Differential Cryptanalysis. Advanced attacks like Biclique attack is also mounted on NUX cipher design. Two different F function in NUX cipher design results in high diffusion mechanism which generates large number of active S-boxes in minimum number of rounds. NUX cipher has total 31 rounds. NUX design will be best-suited design for critical application like smart grid, IoT, wireless sensor network, where memory size, footprint area and the power dissipation are the major constraints.

Keywords: lightweight cryptography, Feistel cipher, block cipher, IoT, encryption, embedded security, ubiquitous computing

Procedia PDF Downloads 325
1140 Constructing White-Box Implementations Based on Threshold Shares and Composite Fields

Authors: Tingting Lin, Manfred von Willich, Dafu Lou, Phil Eisen

Abstract:

A white-box implementation of a cryptographic algorithm is a software implementation intended to resist extraction of the secret key by an adversary. To date, most of the white-box techniques are used to protect block cipher implementations. However, a large proportion of the white-box implementations are proven to be vulnerable to affine equivalence attacks and other algebraic attacks, as well as differential computation analysis (DCA). In this paper, we identify a class of block ciphers for which we propose a method of constructing white-box implementations. Our method is based on threshold implementations and operations in composite fields. The resulting implementations consist of lookup tables and few exclusive OR operations. All intermediate values (inputs and outputs of the lookup tables) are masked. The threshold implementation makes the distribution of the masked values uniform and independent of the original inputs, and the operations in composite fields reduce the size of the lookup tables. The white-box implementations can provide resistance against algebraic attacks and DCA-like attacks.

Keywords: white-box, block cipher, composite field, threshold implementation

Procedia PDF Downloads 132
1139 Evaluating Social Sustainability in Historical City Center in Turkey: Case Study of Bursa

Authors: Şeyda Akçalı

Abstract:

This study explores the concept of social sustainability and its characteristics in terms of neighborhood (mahalle) which is a social phenomenon in Turkish urban life. As social sustainability indicators that moving away traditional themes toward multi-dimensional measures, the solutions for urban strategies may be achieved through learning lessons from historical precedents. It considers the inherent values of traditional urban forms contribute to the evolution of the city as well as the social functions of it. The study aims to measure non-tangible issues in order to evaluate social sustainability in historic urban environments and how they could contribute to the current urban planning strategies. The concept of neighborhood (mahalle) refers to a way of living that represents the organization of Turkish social and communal life rather than defining an administrative unit for the city. The distinctive physical and social features of neighborhood illustrate the link between social sustainability and historic urban environment. Instead of having a nostalgic view of past, it identifies both the failures and successes and extract lessons of traditional urban environments and adopt them to modern context. First, the study determines the aspects of social sustainability which are issued as the key themes in the literature. Then, it develops a model by describing the social features of mahalle which show consistency within the social sustainability agenda. The model is used to analyze the performance of traditional housing area in the historical city center of Bursa, Turkey whether it meets the residents’ social needs and contribute collective functioning of the community. Through a questionnaire survey exercised in the historic neighborhoods, the residents are evaluated according to social sustainability criteria of neighborhood. The results derived from the factor analysis indicate that social aspects of neighborhood are social infrastructure, identity, attachment, neighborliness, safety and wellbeing. Qualitative evaluation shows the relationship between key aspects of social sustainability and demographic and socio-economic factors. The outcomes support that inherent values of neighborhood retain its importance for the sustainability of community although there must be some local arrangements for few factors with great attention not to compromise the others. The concept of neighborhood should be considered as a potential tool to support social sustainability in national political agenda and urban policies. The performance of underlying factors in historic urban environment proposes a basis for both examining and improving traditional urban areas and how it may contribute to the overall city.

Keywords: historical city center, mahalle, neighborhood, social sustainability, traditional urban environment, Turkey

Procedia PDF Downloads 262
1138 The Importance of the Phases of Information, Diagnosis, Planning, Intervention and Management in a Historic Center

Authors: Giovanni Duran Polo

Abstract:

Demonstrate the importance of the stages such as Information, Diagnosis, Management, and Intervention is fundamental to have a historical, live, and quality inhabited center. One of the major actions to take is to promote the concept of the management of a historic center with harmonious development. For that, concerned actors should strengthen the concept that said historic center may be the neighborhood of all and for all. The centers of historical cities, presented as any other urban area, social, environmental issues etc; yet they get added value that have no other city neighborhoods. The equity component, either by the urban plan, or environmental quality offered properties of architectural, landscape or some land uses are the differentiating element, while the tool that makes them attractive face pressure exerted by new housing developments or shopping centers. That's why through the experience of working in historical centers, they are declared the actions in heritage areas. This paper will show how the encounter with each of these places are trying to take the phases of information, to gather all the data needed to be closer to the territory with specific data, diagnosis; which allowed the actors to see what state they were, felt how the heart is related to the rest of the city, show what problems affected the situation and what potential it had to compete in a global market. Also, to discuss the importance of the organization, as it is legal and normative basis for it have an order and a concept, when you know what can and what cannot, in an area where the citizen has many myth or history, when he wanted to intervene in protected buildings. It is also appropriate to show how it could develop the intervention phase, where the shares on the tangible elements and intervention for the protection of the heritage property are executed. The management is the final phase which will carry out all that was raised on paper, it's time to orient, explain, persuade, promote, and encourage citizens to take care of the heritage. It is profitable and also an obligation and it is not an insurmountable burden. It has to be said this is the time to pull all the cards to make the historical center and heritage becoming more alive today. It is the moment to make it more inhabited and to transformer it into a quality place, so citizens will cherish and understand the importance of such a place. Inhabited historical centers, endowments and equipment required, with trade quality, with constant cultural offer, with well-preserved buildings and tidy, modern and safe public spaces are always attractive for tourism, but first of all, the place should be conceived for citizens, otherwise everything will be doomed to failure.

Keywords: development, diagnosis, heritage historic center, intervention, management, patrimony

Procedia PDF Downloads 377
1137 A Retrospective Study of Pain Management Strategies for Pediatric Hypospadias Surgery in a Tertiary Care Hospital in Western Rajasthan

Authors: Darshana Rathod, Kirtikumar Rathod, Kamlesh Kumari, Abhilasha Motghare

Abstract:

Background and Aims: Hypospadias is one of the common congenital anomalies in males. Various modalities are used for pain management, including caudal, penile, pudendal, ring blocks, and systemic analgesics. There has yet to be a consensus regarding the most effective and safe analgesic method for controlling pain in these children. We planned this study to determine our institute's pain management practices for hypospadias surgeries. Material and Methods: This retrospective cohort study reviewed 150 children with hypospadias undergoing surgery from January 2020 to December 2023. Data regarding the mode of pain management, postoperative opioid requirement, PACU discharge, and complications was collected from the records. Results: For postoperative pain, 33 (22%) children received caudal block, 60 (40%) penile block, and 57 (38%) were managed by intravenous analgesics. A significant difference was found in the three groups, with the IV analgesic group requiring significantly higher opioid boluses in PACU [43 (75.4%) required two boluses (p < 0.05)]. The difference in PACU discharge time among the three groups was statistically significant (p< 0.05), with IV analgesics groups having the highest (55 mins [47, 60]), the Caudal group at 35mins (30, 40), and the dorsal penile block group at 35mins (25, 40). There was no significant difference in complications like edema, meatal stenosis, urethra-cutaneous fistula, or wound dehiscence among all three groups. Conclusion: Intravenous analgesics and regional blocks like caudal and penile blocks are the common pain management modalities in our institute. The regional blocks are effective in managing pain in the postoperative period and are not significantly associated with complications.

Keywords: caudal block, hypospadias, pain management, penile block

Procedia PDF Downloads 15
1136 Lidocaine-Bupivacaine Block Improve Analgesia in Cats Undergoing Orchiectomy

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

Abstract:

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

Procedia PDF Downloads 114
1135 Effects of Titanium Dioxide Coatings on Building Composites for Sustainable Construction Applications

Authors: Ifeyinwa Ijeoma Obianyo, Luqman Adedeji Taiwo, Olugbenga O. Amu, Azikiwe Peter Onwualu

Abstract:

Improving the durability of building materials saves maintenance costs, construction time, and energy. In this study, titanium dioxide coated conventional and non-conventional composites were produced, and the effects of titanium dioxide coatings were investigated. Conventional composites were produced using river sand and Portland cement, whereas non-conventional composites were produced by partially replacing river sand and Portland cement with quarry dust and rice husk ash. Water absorption and thickness swelling tests were conducted on the produced coated and non-coated block samples. A reduction in water absorption was observed in the coated composite samples when compared to the non-coated composite samples, and this is an indication of the improved durability of the samples coated with titanium dioxide. However, there was an increase in the thickness swelling of coatings on the coated block samples, but this increase has a slight influence on the compressive strength of the coated samples. The outcome of this study indicates that coating composite building blocks with titanium dioxide will improve theirdurability. Also, the site exposure experiments revealed the self-cleansing properties of TiO2-coated composite block samples, while the Rhodamine B discolouration test confirmed the photocatalytic features of TiO2-coated composite block samples.

Keywords: titanium dioxide, water absorption, durability, mechanical properties, building composite

Procedia PDF Downloads 79