Search results for: urban dead space
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6969

Search results for: urban dead space

3909 Embracing Complex Femininity: A Comparative Analysis of the Representation of Female Sexuality in John Webster and William Faulkner

Authors: Elisabeth Pedersen

Abstract:

Representations and interpretations of womanhood and female sexualities bring forth various questions regarding gender norms, and the implications of these norms, which are permeating and repetitive within various societies. Literature is one form of media which provides the space to represent and interpret women, their bodies, and sexualities, and also reveals the power of language as an affective and affected force. As literature allows an opportunity to explore history and the representations of gender, power dynamics, and sexuality through historical contexts, this paper uses engaged theory through a comparative analysis of two work of literature, The Duchess of Malfi by John Wester, and The Sound and the Fury by William Faulkner. These novels span across space and time, which lends to the theory that repetitive tropes of womanhood and female sexuality in literature are influenced by and have an influence on the hegemonic social order throughout history. It analyzes how the representation of the dichotomy of male chivalry and honor, and female purity are disputed and questioned when a woman is portrayed as sexually emancipated, and explores the historical context in which these works were written to examine how socioeconomic events challenged the hegemonic social order. The analysis looks at how stereotypical ideals of womanhood and manhood have damaging implications on women, as the structure of society provides more privilege and power to men than to women, thus creating a double standard for men and women in regards to sexuality, sexual expression, and rights to sexual desire. This comparative analysis reveals how strict gender norms are permeating and have negative consequences. However, re-reading stories through a critical lens can provide an opportunity to challenge the repetitive tropes of female sexuality, and thus lead to the embrace of the complexity of female sexuality and expression.

Keywords: femininity, literature, representation, sexuality

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3908 The Design of an Afghan Refugee Camp in Kerman City through Ecotech Architecture

Authors: Kourosh Ghaffari, Baghaei Azhang

Abstract:

This study aims to address two main questions whether a camp designed for refugees will affect their quality of life and how to effectively incorporate ecotech architecture into the architectural design of a refugee camp. The current study planned to ensure that the final design reflects the principles of ecotech architecture in most refugee camps. The design process has taken into account various factors, including flexibility, diversity in the camp space according to the ecotech approach, expandability in the building, spatial hierarchy in the design of camp spaces, and the assignment of territories and space sanctuaries to refugees. It should be noted that this study is not a research-oriented type of study and is only limited to collecting information and making hypotheses and questions related to the plan. The researchers attempted to provide a general summary of similar domestic and foreign examples and examine them in similar conditions using the ecotech architecture. The research method utilized in this study was qualitative. Afterwards, the climate studies of the target area, citing and paying attention to the criteria and points extracted from the theoretical framework, reaching the desired conclusion and examining similar examples were followed. Additionally, placement on the site, compliance with relevant standards and regulations, attention to the content and physical program, and addressing the idea and its evolution in all the details of the plan were presented. The data collection procedure included observation and library studies, and the design method was to determine and recognize the subject and examine similar samples. In conclusion, the principles of theoretical foundations, the design protocols in ecotech architecture and the scope of the study are dealt. Furthermore, the site analysis, the design process and the final plan are presented.

Keywords: ecotech architecture, livable city, shelter, refugee camp

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3907 Reuse of Wastewater After Pretreatment Under Teril and Sand in Bechar City

Authors: Sara Seddiki, Maazouzi Abdelhak

Abstract:

The main objective of this modest work is to follow the physicochemical and bacteriological evolution of the wastewater from the town of Bechar subjected to purification by filtration according to various local supports, namely Sable and Terrill by reducing nuisances that undergo the receiving environment (Oued Bechar) and therefore make this water source reusable in different areas. The study first made it possible to characterize the urban wastewater of the Bechar wadi, which presents an environmental threat, thus allowing an estimation of the pollutant load, the chemical oxygen demand COD (145 mg / l) and the biological oxygen demand BOD5 (72 mg / l) revealed that these waters are less biodegradable (COD / BOD5 ratio = 0.62), have a fairly high conductivity (2.76 mS/cm), and high levels of mineral matter presented by chlorides and sulphates 390 and 596.1 mg / l respectively, with a pH of 8.1. The characterization of the sand dune (Beni Abbes) shows that quartz (97%) is the most present mineral. The granular analysis allowed us to determine certain parameters like the uniformity coefficient (CU) and the equivalent diameter, and scanning electron microscope (SEM) observations and X-ray analysis were performed. The study of filtered wastewater shows satisfactory and very encouraging treatment results, with complete elimination of total coliforms and streptococci and a good reduction of total aerobic germs in the sand and clay-sand filter. A good yield has been reported in the sand Terrill filter for the reduction of turbidity. The rates of reduction of organic matter in terms of the biological oxygen demand, in chemical oxygen demand recorded, are of the order of 60%. The elimination of sulphates is 40% for the sand filter.

Keywords: urban wastewater, filtration, bacteriological and physicochemical parameters, sand, Terrill, Oued Bechar

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3906 Analysis of Magnetic Anomaly Data for Identification Structure in Subsurface of Geothermal Manifestation at Candi Umbul Area, Magelang, Central Java Province, Indonesia

Authors: N. A. Kharisa, I. Wulandari, R. Narendratama, M. I. Faisal, K. Kirana, R. Zipora, I. Arfiansah, I. Suyanto

Abstract:

Acquisition of geophysical survey with magnetic method has been done in manifestation of geothermalat Candi Umbul, Grabag, Magelang, Central Java Province on 10-12 May 2013. This objective research is interpretation to interpret structural geology that control geothermal system in CandiUmbul area. The research has been finished with area size 1,5 km x 2 km and measurement space of 150 m. And each point of line space survey is 150 m using PPM Geometrics model G-856. Data processing was started with IGRF and diurnal variation correction to get total magnetic field anomaly. Then, advance processing was done until reduction to pole, upward continuation, and residual anomaly. That results become next interpretation in qualitative step. It is known that the biggest object position causes low anomaly located in central of area survey that comes from hot spring manifestation and demagnetization zone that indicates the existence of heat source activity. Then, modeling the anomaly map was used for quantitative interpretation step. The result of modeling is rock layers and geological structure model that can inform about the geothermal system. And further information from quantitative interpretations can be interpreted about lithology susceptibility. And lithology susceptibilities are andesiteas heat source has susceptibility value of (k= 0.00014 emu), basaltic as alteration rock (k= 0.0016 emu), volcanic breccia as reservoir rock (k= 0.0026 emu), andesite porfirtic as cap rock (k= 0.004 emu), lava andesite (k= 0.003 emu), and alluvium (k= 0.0007 emu). The hot spring manifestation is controlled by the normal fault which becomes a weak zone, easily passed by hot water which comes from the geothermal reservoir.

Keywords: geological structure, geothermal system, magnetic, susceptibility

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3905 Importance of the Bali Strait for Devil Ray Reproduction

Authors: Irianes C. Gozali, Betty J.L. Laglbauer, Muhammad G. Salim, Sila K. Sari, Fahmi Fahmi, Selvia Oktaviyani

Abstract:

Muncar, located off the eastern coast of Java, is an important fishing port for small-scale fleets which land mobulid rays as retained bycatch, primarily in drift gillnets. Due to overlap with fishing grounds in the Bali Strait, three devil ray species are landed in Muncar, the spinetail devil ray Mobula mobular, the bentfin devil ray Mobula thurstoni, and the Chilean devil ray Mobula tarapacana, which are all listed as Endangered by the International Union for the Conservation of Nature. However, despite the importance of life-history data to better manage stocks, such information is still rare or unavailable for Indonesian mobulid ray populations. Using morphometric data, reproductive assessments, and samples collected from dead specimens at fish markets from 2015-2019, we provide information on the maturity stage, reproductive periodicity, gestation, and size at parturition. A majority of immature individuals of all three devil ray species were recorded (<10% individuals in Mobula mobular to <30% individuals in Mobula thurstoni). Pregnant females of two species, Mobula mobular and Mobula thurstoni were recorded containing embryos of various developmental stages (each with a single embryo in the left functional uterus), while for Mobula tarapacana, no fetuses were found. The largest embryo recorded in M. mobular was within the range of that previously reported for neonates of the species in Indonesia (957 cm, for a 920-994 range), and represents a near-term embryo reflecting size at parturition. Low reproductive output was confirmed for the study-species. Based on this study, we infer that the Bali Straight is likely an important location for devil ray reproduction, which raises concern for the sustainability of mobulid ray populations in the face of bycatch in drift gillnets. Potential management approaches to tackle this issue are discussed.

Keywords: devil ray, mobulid, reproduction, Indonesia

Procedia PDF Downloads 172
3904 Simulation of a Sustainable Irrigation System Development: The Case of Sitio Kantaling Village Farm Lands, Danao City, Cebu, Philippines

Authors: Amando A. Radomes Jr., LLoyd Jun Benjamin T. Embernatre, Cherssy Kaye F. Eviota, Krizia Allyn L. Nunez, Jose Thaddeus B. Roble III

Abstract:

Sitio Kantaling is one of the 34 villages in Danao City, Cebu, in the central Philippines. As of 2015, the eight households in the mountainous village extending over 40 hectares of land area, including 12 hectares of arable land, are the source of over a fifth of the agricultural products that go into the city. Over the years, however, the local government had been concerned with the decline in agricultural productivity because increasing number of residents are migrating into the urban areas of the region to look for better employment opportunities. One of the major reasons for the agricultural productivity decline is underdeveloped irrigation infrastructure. The local government had partnered with the University of San Carlos to conduct research on developing an irrigation system that could sustainably meet both agricultural and household consumption needs. From a macro-perspective, a dynamic simulation model was developed to understand the long-term behavior of the status quo and proposed the system. Data on population, water supply and demand, household income, and urban migration were incorporated in the 20-year horizon model. The study also developed a smart irrigation system design. Instead of using electricity to pump water, a network of aqueducts with three main nodes had been designed and strategically located to take advantage of gravity to transport water from a spring. Simulation results showed that implementing a sustainable irrigation system would be able to significantly contribute to the socio-economic progress of the local community.

Keywords: agriculture, aqueduct, simulation, sustainable irrigation system

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3903 Development of a Framework for Assessing Public Health Risk Due to Pluvial Flooding: A Case Study of Sukhumvit, Bangkok

Authors: Pratima Pokharel

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When sewer overflow due to rainfall in urban areas, this leads to public health risks when an individual is exposed to that contaminated floodwater. Nevertheless, it is still unclear the extent to which the infections pose a risk to public health. This study analyzed reported diarrheal cases by month and age in Bangkok, Thailand. The results showed that the cases are reported higher in the wet season than in the dry season. It was also found that in Bangkok, the probability of infection with diarrheal diseases in the wet season is higher for the age group between 15 to 44. However, the probability of infection is highest for kids under 5 years, but they are not influenced by wet weather. Further, this study introduced a vulnerability that leads to health risks from urban flooding. This study has found some vulnerability variables that contribute to health risks from flooding. Thus, for vulnerability analysis, the study has chosen two variables, economic status, and age, that contribute to health risk. Assuming that the people's economic status depends on the types of houses they are living in, the study shows the spatial distribution of economic status in the vulnerability maps. The vulnerability map result shows that people living in Sukhumvit have low vulnerability to health risks with respect to the types of houses they are living in. In addition, from age the probability of infection of diarrhea was analyzed. Moreover, a field survey was carried out to validate the vulnerability of people. It showed that health vulnerability depends on economic status, income level, and education. The result depicts that people with low income and poor living conditions are more vulnerable to health risks. Further, the study also carried out 1D Hydrodynamic Advection-Dispersion modelling with 2-year rainfall events to simulate the dispersion of fecal coliform concentration in the drainage network as well as 1D/2D Hydrodynamic model to simulate the overland flow. The 1D result represents higher concentrations for dry weather flows and a large dilution of concentration on the commencement of a rainfall event, resulting in a drop of the concentration due to runoff generated after rainfall, whereas the model produced flood depth, flood duration, and fecal coliform concentration maps, which were transferred to ArcGIS to produce hazard and risk maps. In addition, the study also simulates the 5-year and 10-year rainfall simulations to show the variation in health hazards and risks. It was found that even though the hazard coverage is very high with a 10-year rainfall events among three rainfall events, the risk was observed to be the same with a 5-year and 10-year rainfall events.

Keywords: urban flooding, risk, hazard, vulnerability, health risk, framework

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3902 An Overview of Informal Settlement Upgrading Strategies in Kabul City and the Need for an Integrated Multi-Sector Upgrading Model

Authors: Bashir Ahmad Amiri, Nsenda Lukumwena

Abstract:

The developing economies are experiencing an unprecedented rate of urbanization, mainly the urbanization of poverty which is leading to sprawling of slums and informal settlement. Kabul, being the capital and primate city of Afghanistan is grossly encountered to the informal settlement where the majority of the people consider to be informal. Despite all efforts to upgrade and minimize the growth of these settlements, they are growing rapidly. Various interventions have been taken by the government and some international organizations from physical upgrading to urban renewal, but none of them have succeeded to solve the issue of informal settlement. The magnitude of the urbanization and the complexity of informal settlement in Kabul city, and the institutional and capital constraint of the government calls for integration and optimization of currently practiced strategies. This paper provides an overview of informal settlement formation and the conventional upgrading strategies in Kabul city to identify the dominant/successful practices and rationalize the conventional upgrading modes. For this purpose, Hothkhel has been selected as the case study, since it represents the same situation of major informal settlements of the city. Considering the existing potential and features of the Hothkhel and proposed land use by master plan this paper intends to find a suitable upgrading mode for the study area and finally to scale up the model for the city level upgrading. The result highlights that the informal settlements of Kabul city have high (re)development capacity for accepting the additional room without converting the available agricultural area to built-up. The result also indicates that the integrated multi-sector upgrading has the scale-up potential to increase the reach of beneficiaries and to ensure an inclusive and efficient urbanization.

Keywords: informal settlement, upgrading strategies, Kabul city, urban expansion, integrated multi-sector, scale-up

Procedia PDF Downloads 159
3901 A Multi-Stage Learning Framework for Reliable and Cost-Effective Estimation of Vehicle Yaw Angle

Authors: Zhiyong Zheng, Xu Li, Liang Huang, Zhengliang Sun, Jianhua Xu

Abstract:

Yaw angle plays a significant role in many vehicle safety applications, such as collision avoidance and lane-keeping system. Although the estimation of the yaw angle has been extensively studied in existing literature, it is still the main challenge to simultaneously achieve a reliable and cost-effective solution in complex urban environments. This paper proposes a multi-stage learning framework to estimate the yaw angle with a monocular camera, which can deal with the challenge in a more reliable manner. In the first stage, an efficient road detection network is designed to extract the road region, providing a highly reliable reference for the estimation. In the second stage, a variational auto-encoder (VAE) is proposed to learn the distribution patterns of road regions, which is particularly suitable for modeling the changing patterns of yaw angle under different driving maneuvers, and it can inherently enhance the generalization ability. In the last stage, a gated recurrent unit (GRU) network is used to capture the temporal correlations of the learned patterns, which is capable to further improve the estimation accuracy due to the fact that the changes of deflection angle are relatively easier to recognize among continuous frames. Afterward, the yaw angle can be obtained by combining the estimated deflection angle and the road direction stored in a roadway map. Through effective multi-stage learning, the proposed framework presents high reliability while it maintains better accuracy. Road-test experiments with different driving maneuvers were performed in complex urban environments, and the results validate the effectiveness of the proposed framework.

Keywords: gated recurrent unit, multi-stage learning, reliable estimation, variational auto-encoder, yaw angle

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3900 The Comparison of Bird’s Population between Naturally Regenerated Acacia Forest with Adjacent Secondary Indigenous Forest in Universiti Malaysia Sabah

Authors: Jephte Sompud, Emily A. Gilbert, Andy Russel Mojiol, Cynthia B. Sompud, Alim Biun

Abstract:

Naturally regenerated acacia forest and secondary indigenous forest forms some of the urban forests in Sabah. Naturally regenerated acacia trees are usually seen along the road that exists as forest islands. Acacia tree is not an indigenous tree species in Sabah that was introduced in the 1960’s as fire breakers that eventually became one of the preferred trees for forest plantation for paper and pulp production. Due to its adaptability to survive even in impoverished soils and poor-irrigated land, this species has rapidly spread throughout Sabah through natural regeneration. Currently, there is a lack of study to investigate the bird population in the naturally regenerated acacia forest. This study is important because it shed some light on the role of naturally regenerated acacia forest on bird’s population, as bird is known to be a good bioindicator forest health. The aim of this study was to document the bird’s population in naturally regenerated acacia forest with that adjacent secondary indigenous forest. The study site for this study was at Universiti Malaysia Sabah (UMS) Campus. Two forest types in the campus were chosen as a study site, of which were naturally regenerated Acacia Forest and adjacent secondary indigenous forest, located at the UMS Hill. A total of 21 sampling days were conducted in each of the forest types. The method used during this study was solely mist nets with three pockets. Whenever a bird is caught, it is extracted from the net to be identified and measurements were recorded in a standard data sheet. Mist netting was conducted from 6 morning until 5 evening. This study was conducted between February to August 2014. Birds that were caught were ring banded to initiate a long-term study on the understory bird’s population in the Campus The data was analyzed using descriptive analysis, diversity indices, and t-test. The bird population diversity at naturally regenerated Acacia forest with those at the secondary indigenous forest was calculated using two common indices, of which were Shannon-Wiener and Simpson diversity index. There were 18 families with 33 species that were recorded from both sites. The number of species recorded at the naturally regenerated acacia forest was 26 species while at the secondary indigenous forest were 19 species. The Shannon diversity index for Naturally Regenerated Acacia Forest and secondary indigenous forests were 2.87 and 2.46. The results show that there was very significantly higher species diversity at the Naturally Regenerated Acacia Forest as opposed to the secondary indigenous forest (p<0.001). This suggests that Naturally Regenerated Acacia forest plays an important role in urban bird conservation. It is recommended that Naturally Regenerated Acacia Forests should be considered as an established urban forest conservation area as they do play a role in biodiversity conservation. More future studies in Naturally Regenerated Acacia Forest should be encouraged to determine the status and value of biodiversity conservation of this ecosystem.

Keywords: naturally regenerated acacia forest, bird population diversity, Universiti Malaysia Sabah, biodiversity conservation

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3899 Analysis of Dynamics Underlying the Observation Time Series by Using a Singular Spectrum Approach

Authors: O. Delage, H. Bencherif, T. Portafaix, A. Bourdier

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The main purpose of time series analysis is to learn about the dynamics behind some time ordered measurement data. Two approaches are used in the literature to get a better knowledge of the dynamics contained in observation data sequences. The first of these approaches concerns time series decomposition, which is an important analysis step allowing patterns and behaviors to be extracted as components providing insight into the mechanisms producing the time series. As in many cases, time series are short, noisy, and non-stationary. To provide components which are physically meaningful, methods such as Empirical Mode Decomposition (EMD), Empirical Wavelet Transform (EWT) or, more recently, Empirical Adaptive Wavelet Decomposition (EAWD) have been proposed. The second approach is to reconstruct the dynamics underlying the time series as a trajectory in state space by mapping a time series into a set of Rᵐ lag vectors by using the method of delays (MOD). Takens has proved that the trajectory obtained with the MOD technic is equivalent to the trajectory representing the dynamics behind the original time series. This work introduces the singular spectrum decomposition (SSD), which is a new adaptive method for decomposing non-linear and non-stationary time series in narrow-banded components. This method takes its origin from singular spectrum analysis (SSA), a nonparametric spectral estimation method used for the analysis and prediction of time series. As the first step of SSD is to constitute a trajectory matrix by embedding a one-dimensional time series into a set of lagged vectors, SSD can also be seen as a reconstruction method like MOD. We will first give a brief overview of the existing decomposition methods (EMD-EWT-EAWD). The SSD method will then be described in detail and applied to experimental time series of observations resulting from total columns of ozone measurements. The results obtained will be compared with those provided by the previously mentioned decomposition methods. We will also compare the reconstruction qualities of the observed dynamics obtained from the SSD and MOD methods.

Keywords: time series analysis, adaptive time series decomposition, wavelet, phase space reconstruction, singular spectrum analysis

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3898 Measuring Quality of Participation Processes: A Literature Review and Case Study to Determine Criteria for the Influence of Digital Tools

Authors: Michaela Kaineder, Beate Bartlmae, Stefan Gaebler, Miriam Gutleder, Marlene Wuerfl

Abstract:

Digital tools and e-participation processes have seen a steady increase in popularity in recent years. While online trends come with the premise of new opportunities and easier participatory possibilities, there are still manifold challenges that smart city initiators and developers need to face. In this paper, innovative quality criteria of citizen participation processes was suggested by defining meaningful and measurable evaluation categories. Considering various developments, including the global megatrend of connectivity, a need for a fundamental examination of the basic structure of citizen participation processes was identified. To this end, the application of methods and tools through different points in the policy cycle is required. In order to provide an overview of the current challenges and problems in the field of participation, this paper analyzes those issues by carrying out a literature review that also focuses on disparities in the civic sector that might hinder residents in their desire for engagement. Additionally, a case study was chosen to demonstrate the potential that e-participation tools offer to planning experts and public authorities when integrating citizen’s creativity and experience at a large scale. This online co-creation process finally leads to offline events – such as local co-design workshops - with professional planners. The findings of this paper subsequently suggest a combination of e-participation and analogue forms to merge the benefits of both worlds, resulting in a broader audience and higher quality for participation processes.

Keywords: citizen participation, disparities, e-participation, integrated urban development, sustainable development goals, sustainable urban development

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3897 Powers of Class p-w A (s, t) Operators Associated with Generalized Aluthge Transformations

Authors: Mohammed Husein Mohammed Rashid

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Let Τ = U |Τ| be a polar decomposition of a bounded linear operator T on a complex Hilbert space with ker U = ker |T|. T is said to be class p-w A(s,t) if (|T*|ᵗ|T|²ˢ|T*|ᵗ )ᵗᵖ/ˢ⁺ᵗ ≥|T*|²ᵗᵖ and |T|²ˢᵖ ≥ (|T|ˢ|T*|²ᵗ|T|ˢ)ˢᵖ/ˢ⁺ᵗ with 0Keywords: class p-w A (s, t), normaloid, isoloid, finite, orthogonality

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3896 Assessing Sustainability Dimensions of Transportation as a Critical Infrastructure: Jordan as a Case Study

Authors: Malak M. Shatnawi

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Infrastructure is the fundamental facility that plays an important part in socio-economic development for modern societies, if such sector is well planned, managed by decision makers in a way that is compatible with the population growth, safety, and national security needs; it will enrich progress, prosperity, awareness, social and economic welfare for any country. Infrastructure is the most important aspect of life because it can provide materials, products, and services that will improve and facilitate living conditions and maintain sustainability at the same time, and in order to study critical infrastructure, in general, we must think sustainability. Otherwise there will be a significant gap. The planning processes for sustainability include urban infrastructure and public transportation are considered the most important sectors for economic development for both developed and developing countries as they are linked to the civilizational and urban development, meanwhile, choosing the appropriate transportation mode that will provide a good level of service, and increase the satisfaction of the potential users is a difficult task. This research paper tries to assess where is Jordan located vs. each transportation sustainability dimensions in aspects related to social, economic and environmental dimensions based on (Zietsman et al. 2006) adopted model for sustainability transportation infrastructure. Measures of performance indicators for each dimensional goal were traced and supported with needed data, figures and statistical findings. The study uses analytical, descriptive style and methodology based on different references and previous studies from secondary data sources to support the case. Recommendations for enhancing sustainability were concluded, and future reform directions were proposed which can be applied to Jordan and generalized for other developing countries with similar circumstances.

Keywords: infrastructure transportation sustainability, economic, social, environmental

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3895 Pleated Surfaces: Experimentation and Examples

Authors: Maritza Granados Manjarrés

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This paper makes part of an investigation project which experiments with flat surfaces in order to pleat them using tessellations and flat origami conditions. The aim of the investigation is to eventually propose not only a methodology on how to pleat those surfaces but also to find an structural system to make them work as building skins. This stage of the investigation emphasizes on the experimentation with flat surfaces and different kinds of folding patterns and shows the many examples that can be made from this experimentation.

Keywords: flat origami, fold, space, surface

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3894 Real-Space Mapping of Surface Trap States in Cigse Nanocrystals Using 4D Electron Microscopy

Authors: Riya Bose, Ashok Bera, Manas R. Parida, Anirudhha Adhikari, Basamat S. Shaheen, Erkki Alarousu, Jingya Sun, Tom Wu, Osman M. Bakr, Omar F. Mohammed

Abstract:

This work reports visualization of charge carrier dynamics on the surface of copper indium gallium selenide (CIGSe) nanocrystals in real space and time using four-dimensional scanning ultrafast electron microscopy (4D S-UEM) and correlates it with the optoelectronic properties of the nanocrystals. The surface of the nanocrystals plays a key role in controlling their applicability for light emitting and light harvesting purposes. Typically for quaternary systems like CIGSe, which have many desirable attributes to be used for optoelectronic applications, relative abundance of surface trap states acting as non-radiative recombination centre for charge carriers remains as a major bottleneck preventing further advancements and commercial exploitation of these nanocrystals devices. Though ultrafast spectroscopic techniques allow determining the presence of picosecond carrier trapping channels, because of relative larger penetration depth of the laser beam, only information mainly from the bulk of the nanocrystals is obtained. Selective mapping of such ultrafast dynamical processes on the surfaces of nanocrystals remains as a key challenge, so far out of reach of purely optical probing time-resolved laser techniques. In S-UEM, the optical pulse generated from a femtosecond (fs) laser system is used to generate electron packets from the tip of the scanning electron microscope, instead of the continuous electron beam used in the conventional setup. This pulse is synchronized with another optical excitation pulse that initiates carrier dynamics in the sample. The principle of S-UEM is to detect the secondary electrons (SEs) generated in the sample, which is emitted from the first few nanometers of the top surface. Constructed at different time delays between the optical and electron pulses, these SE images give direct and precise information about the carrier dynamics on the surface of the material of interest. In this work, we report selective mapping of surface dynamics in real space and time of CIGSe nanocrystals applying 4D S-UEM. We show that the trap states can be considerably passivated by ZnS shelling of the nanocrystals, and the carrier dynamics can be significantly slowed down. We also compared and discussed the S-UEM kinetics with the carrier dynamics obtained from conventional ultrafast time-resolved techniques. Additionally, a direct effect of the state trap removal can be observed in the enhanced photoresponse of the nanocrystals after shelling. Direct observation of surface dynamics will not only provide a profound understanding of the photo-physical mechanisms on nanocrystals’ surfaces but also enable to unlock their full potential for light emitting and harvesting applications.

Keywords: 4D scanning ultrafast microscopy, charge carrier dynamics, nanocrystals, optoelectronics, surface passivation, trap states

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3893 Making Food Science Education and Research Activities More Attractive for University Students and Food Enterprises by Utilizing Open Innovative Space-Approach

Authors: Anna-Maria Saarela

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At the Savonia University of Applied Sciences (UAS), curriculum and studies have been improved by applying an Open Innovation Space approach (OIS). It is based on multidisciplinary action learning. The key elements of OIS-ideology are work-life orientation, and student-centric communal learning. In this approach, every participant can learn from each other and innovations will be created. In this social innovation educational approach, all practices are carried out in close collaboration with enterprises in real-life settings, not in classrooms. As an example, in this paper, Savonia UAS’s Future Food RDI hub (FF) shows how OIS practices are implemented by providing food product development and consumer research services for enterprises in close collaboration with academicians, students and consumers. In particular one example of OIS experimentation in the field is provided by a consumer research carried out utilizing verbal analysis protocol combined with audio-visual observation (VAP-WAVO). In this case, all co-learners were acting together in supermarket settings to collect the relevant data for a product development and the marketing department of a company. The company benefitted from the results obtained, students were more satisfied with their studies, educators and academicians were able to obtain good evidence for further collaboration as well as renewing curriculum contents based on the requirements of working life. In addition, society will benefit over time as young university adults find careers more easily through their OIS related food science studies. Also this knowledge interaction model re-news education practices and brings working-life closer to educational research institutes.

Keywords: collaboration, education, food science, industry, knowledge transfer, RDI, student

Procedia PDF Downloads 365
3892 Microfluidic Based High Throughput Screening System for Photodynamic Therapy against Cancer Cells

Authors: Rina Lee, Chung-Hun Oh, Eunjin Lee, Jeongyun Kim

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The Photodynamic therapy (PDT) is a treatment that uses a photosensitizer as a drug to damage and kill cancer cells. After injecting the photosensitizer into the bloodstream, the drug is absorbed by cancer cells selectively. Then the area to be treated is exposed to specific wavelengths of light and the photosensitizer produces a form of oxygen that kills nearby cancer cells. PDT is has an advantage to destroy the tumor with minimized side-effects on normal cells. But, PDT is not a completed method for cancer therapy. Because the mechanism of PDT is quite clear yet and the parameters such as intensity of light and dose of photosensitizer are not optimized for different types of cancers. To optimize these parameters, we suggest a novel microfluidic system to automatically control intensity of light exposure with a personal computer (PC). A polydimethylsiloxane (PDMS) microfluidic chip is composed with (1) a cell culture channels layer where cancer cells were trapped to be tested with various dosed photofrin (1μg/ml used for the test) as the photosensitizer and (2) a color dye layer as a neutral density (ND) filter to reduce intensity of light which exposes the cell culture channels filled with cancer cells. Eight different intensity of light (10%, 20%, …, 100%) are generated through various concentrations of blue dye filling the ND filter. As a light source, a light emitting diode (LED) with 635nm wavelength was placed above the developed PDMS microfluidic chip. The total time for light exposure was 30 minutes and HeLa and PC3 cell lines of cancer cells were tested. The cell viability of cells was evaluated with a Live/Dead assay kit (L-3224, Invitrogen, USA). The stronger intensity of light exposed, the lower viability of the cell was observed, and vice versa. Therefore, this system was demonstrated through investigating the PDT against cancer cell to optimize the parameters as critical light intensity and dose of photosensitizer. Our results suggest that the system can be used for optimizing the combinational parameters of light intensity and photosensitizer dose against diverse cancer cell types.

Keywords: photodynamic therapy, photofrin, high throughput screening, hela

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3891 CLEAN Jakarta Waste Bank Project: Alternative Solution in Urban Solid Waste Management by Community Based Total Sanitation (CBTS) Approach

Authors: Mita Sirait

Abstract:

Everyday Jakarta produces 7,000 tons of solid waste and only about 5,200 tons delivered to landfill out of the city by 720 trucks, the rest are left yet manageable, as reported by Government of Clean Sector. CLEAN Jakarta Project is aimed at empowering community to achieve healthy environment for children and families in urban slum in Semper Barat and Penjaringan sub-district of North Jakarta that consisted of 20,584 people. The project applies Community Based Total Sanitation, an approach to empowering community to achieve total hygiene and sanitation behaviour by triggering activities. As regulated by Ministry of Health, it has 5 pillars: (1) open defecation free, (2) hand-washing with soaps, (3) drinking-water treatment, (4) solid-waste management and (5) waste-water management; and 3 strategic components: 1) demand creation, 2) supply creation and 3) enabling environment. Demand creation is generated by triggering community’s reaction to their daily sanitation habits by exposing them to their surrounding where they can see faeces, waste and other environmental pollutant to stimulate disgusting, embarrassing and responsibility sense. Triggered people then challenged to commit to improving their hygiene practice such as to stop littering and start waste separation. In order to support this commitment, and for supply creation component, the project initiated waste bank with community working group. It facilitated capacity-building trainings, waste bank system formulation and meetings with local authorities to solicit land permit and waste bank decree. As it is of a general banking system, waste bank has customer service, teller, manager, legal paper and provides saving book and money transaction. In 8 months, two waste banks have established with 148 customers, 17 million rupiah cash, and about 9 million of stored recyclables. Approximately 2.5 tons of 15-35 types of recyclable are managed in both waste banks per week. On enabling environment, the project has initiated sanitation working group in community and multi sectors government level, and advocated both parties. The former is expected to promote behaviour change and monitoring in the community, while the latter is expected to support sanitation with regulations, strategies, appraisal and awards; to coordinate partnering and networking, and to replicate best practices to other areas.

Keywords: urban community, waste management, Jakarta, community based total sanitation (CBTS)

Procedia PDF Downloads 287
3890 Optimization of Interface Radio of Universal Mobile Telecommunication System Network

Authors: O. Mohamed Amine, A. Khireddine

Abstract:

Telecoms operators are always looking to meet their share of the other customers, they try to gain optimum utilization of the deployed equipment and network optimization has become essential. This project consists of optimizing UMTS network, and the study area is an urban area situated in the center of Algiers. It was initially questions to become familiar with the different communication systems (3G) and the optimization technique, its main components, and its fundamental characteristics radios were introduced.

Keywords: UMTS, UTRAN, WCDMA, optimization

Procedia PDF Downloads 370
3889 Left Posterior Pericardiotomy in the Prevention of Post-Operative Atrial Fibrillation and Cardiac Tamponade: A Retrospective Study of 2118 Isolated Coronary Artery Bypass Graft Patients

Authors: Ayeshmanthe Rathnayake, Siew Goh, Carmel Fenton, Ashutosh Hardikar

Abstract:

Post-Operative Atrial Fibrillation (POAF) is the most frequent complication of cardiac surgery and is associated with reduced survival, increased rates of cognitive changes and cerebrovascular accident, heart failure, renal dysfunction, infection and length of stay, and hospital costs. Cardiac tamponade, although less common, carries high morbidity and mortality. Shed mediastinal blood in the pericardial space is a major source of intrapericardial oxidative stress and inflammation that triggers POAF. The utilisation of a left posterior pericardiotomy aims to shunt blood from the pericardium into the pleural space and have a role in the prevention of POAF as well as cardiac tamponade. 2118 patients had undergone isolated Coronary Artery Bypass Graft (CABG) at Royal Hobart Hospital from 2008-2021. They were divided into pericardiotomy vs control group. Patient baseline demographics, intraoperative data, and post-operative outcomes were reviewed retrospectively. Total incidence of new POAF and cardiac tamponade was 26.1% and 0.75%, respectively. Primary outcome of both the incidence of POAF(22.9% vs27.8%OR 0.77 p<0.05) and Cardiac Tamponade (0% vs 1.1% OR 0.85 p<0.05) were less in the pericardiotomy group.Increasing age, BMI, poor left ventricular function (EF <30%), and return to theatre were independent predictors of developing POAF. There were similar rates of return to theatre for bleeding however, no cases of tamponade in the pericardiotomy group. There were no complications attributable to left posterior pericardiotomy and the time added to the duration of surgery was minimal. Left posterior pericardiotomy is associated with a significant reduction in the incidence of POAFand cardiac tamponade and issafe and efficient.

Keywords: cardiac surgery, pericardiotomy, post-operative atrial fibrillation, cardiac tamponade

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3888 On a Negative Relation between Bacterial Taxis and Turing Pattern Formation

Authors: A. Elragig, S. Townley, H. Dreiwi

Abstract:

In this paper we introduce a bacteria-leukocyte model with bacteria chemotaxsis. We assume that bacteria develop a tactic defense mechanism as a response to Leukocyte phagocytosis. We explore the effect of this tactic motion on Turing space in two parameter spaces. A fine tuning of bacterial chemotaxis shows a significant effect on developing a non-uniform steady state.

Keywords: chemotaxis-diffusion driven instability, bacterial chemotaxis, mathematical biology, ecology

Procedia PDF Downloads 356
3887 Between the House and the City: An Investigation of the Structure of the Family/Society and the Role of the Public Housing in Tokyo and Berlin

Authors: Abudjana Babiker

Abstract:

The middle of twenty century witnessed an explosion in public housing. After the great depression, some of the capitalists and communist countries have launched policies and programs to produce public housing in the urban areas. Concurrently, modernity was the leading architecture style at the time excessively supported the production, and principally was the instrument for the success of the public housing program due to the modernism manifesto for manufactured architecture as an international style that serves the society and parallelly connect it to the other design industries which allowed for the production of the architecture elements. After the second world war, public housing flourished, especially in communist’s countries. The idea of public housing was conceived as living spaces at the time, while the Workplaces performed as the place for production and labor. Michel Foucault - At the end of the twenty century- the introduction of biopolitics has had highlighted the alteration in the production and labor inter-function. The house does not precisely perform as the sanctuary, from the production, for the family, it opens the house to be -part of the city as- a space for production, not only to produce objects but to reproduce the family as a total part of the production mechanism in the city. While the public housing kept altering from one country to another after the failure of the modernist’s public housing in the late 1970s, the society continued changing parallelly with the socio-economic condition in each political-economical system, and the public housing thus followed. The family structure in the major cities has been dramatically changing, single parenting and the long working hours, for instance, have been escalating the loneliness in the major cities such as London, Berlin, and Tokyo and the public housing for the families is no longer suits the single lifestyle for the individuals. This Paper investigates the performance of both the single/individual lifestyle and the family/society structure in Tokyo and Berlin in a relation to the utilization of public housing under economical policies and the socio-political environment that produced the individuals and the collective. The study is carried through the study of the undercurrent individual/society and case studies to examine the performance of the utilization of the housing. The major finding is that the individual/collective are revolving around the city; the city identified and acts as a system that magnetized and blurred the line between production and reproduction lifestyle. The mass public housing for families is shifting to be a combination between neo-liberalism and socialism housing.

Keywords: loneliness, production reproduction, work live, publichousing

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3886 Determination of the Runoff Coefficient in Urban Regions, an Example from Haifa, Israel

Authors: Ayal Siegel, Moshe Inbar, Amatzya Peled

Abstract:

This study examined the characteristic runoff coefficient in different urban areas. The main area studied is located in the city of Haifa, northern Israel. Haifa spreads out eastward from the Mediterranean seacoast to the top of the Carmel Mountain range with an elevation of 300 m. above sea level. For this research project, four watersheds were chosen, each characterizing a different part of the city; 1) Upper Hadar, a spacious suburb on the upper mountain side; 2) Qiryat Eliezer, a crowded suburb on a level plane of the watershed; 3) Technion, a large technical research university which is located halfway between the top of the mountain range and the coast line. 4) Keret, a remote suburb, on the southwestern outskirts of Haifa. In all of the watersheds found suitable, instruments were installed to continuously measure the water level flowing in the channels. Three rainfall gauges scattered in the study area complete the hydrological requirements for this research project. The runoff coefficient C in peak discharge events was determined by the Rational Formula. The main research finding is the significant relationship between the intensity of rainfall, and the impervious area which is connected to the drainage system of the watershed. For less intense rainfall, the full potential of the connected impervious area will not be exploited. As a result, the runoff coefficient value decreases as do the peak discharge rate and the runoff yield from the storm event. The research results will enable application to other areas by means of hydrological model to be be set up on GIS software that will make it possible to estimate the runoff coefficient of any given city watershed.

Keywords: runoff coefficient, rational method, time of concentration, connected impervious area.

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3885 Measurement of Radon Exhalation Rate, Natural Radioactivity, and Radiation Hazard Assessment in Soil Samples from the Surrounding Area of Kasimpur Thermal Power Plant Kasimpur (U. P.), India

Authors: Anil Sharma, Ajay Kumar Mahur, R. G. Sonkawade, A. C. Sharma, R. Prasad

Abstract:

In coal fired thermal power stations, large amount of fly ash is produced after burning of coal. Fly ash is spread and distributed in the surrounding area by air and may be deposited on the soil of the region surrounding the power plant. Coal contains increased levels of these radionuclides and fly ash may increase the radioactivity in the soil around the power plant. Radon atoms entering into the pore space from the mineral grain are transported by diffusion and advection through this space until they in turn decay or are released into the atmosphere. In the present study, Soil samples were collected from the region around a Kasimpur Thermal Power Plant, Kasimpur, Aligarh (U.P.). Radon activity, radon surface exhalation and mass exhalation rates were measured using “sealed can technique” using LR 115-type II nuclear track detectors. Radon activities vary from 92.9 to 556.8 Bq m-3 with mean value of 279.8 Bq m-3. Surface exhalation rates (EX) in these samples are found to vary from 33.4 to 200.2 mBq m-2 h-1 with an average value of 100.5 mBq m-2 h-1 whereas, Mass exhalation rates (EM) vary from 1.2 to 7.7 mBq kg-1 h-1 with an average value of 3.8 mBq kg-1 h-1. Activity concentrations of radionuclides were measured in these samples by using a low level NaI (Tl) based gamma ray spectrometer. Activity concentrations of 226Ra 232Th and 40K vary from 12 to 49 Bq kg-1, 24 to 49 Bq kg-1 and 135 to 546 Bq kg-1 with overall mean values of 30.3 Bq kg-1, 38.5 Bq kg-1 and 317.8 Bq kg-1, respectively. Radium equivalent activity has been found to vary from 80.0 to 143.7 Bq kg-1 with an average value of 109.7 Bq kg-1. Absorbed dose rate varies from 36.1 to 66.4 nGy h-1 with an average value of 50.4 nGy h-1 and corresponding outdoor annual effective dose varies from 0.044 to 0.081 mSv with an average value of 0.061 mSv. Values of external and internal hazard index Hex, Hin in this study vary from 0.21 to 0.38 and 0.27 to 0.50 with an average value of 0.29 and 0.37, Respectively. The results will be discussed in light of various factors.

Keywords: natural radioactivity, radium equivalent activity, absorbed dose rate, gamma ray spectroscopy

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3884 Virtual Reference Service as a Space for Communication and Interaction: Providing Infrastructure for Learning in Times of Crisis at Uppsala University

Authors: Nadja Ylvestedt

Abstract:

Uppsala University Library is a geographically dispersed research library consisting of nine subject libraries located in different campus areas throughout the city of Uppsala. Despite the geographical dispersion, it is the library's ambition to be perceived as a cohesive library with consistently high service and quality. A key factor to being one cohesive library is the library's online services, especially the virtual reference service. E-mail, chat and phone are answered by a team of specially trained staff under the supervision of a team leader. When covid-19 hit, well-established routines and processes to provide an infrastructure for students and researchers at the university changed radically. The strong connection between services provided at the library locations as well as at the VRS has been one of the key components of the library’s success in providing patrons with the help they need. With radically minimized availability at the physical locations, the infrastructure was at risk of collapsing. Objectives:- The objective of this project has been to evaluate the consequences of the sudden change in the organization of the library. The focus of this evaluation is the library’s VRS as an important space for learning, interaction and communication between the library and the community when other traditional spaces were not available. The goal of this evaluation is to capture the lessons learned from providing infrastructure for learning and research in times of crisis both on a practical, user-centered level but also to stress the importance of leadership in ever-changing environments that supports and creates agile, flexible services and teams instead of rigid processes adhering to obsolete goals. Results:- Reduced availability at the physical library locations was one of the strategies to prevent the spread of the covid-19 virus. The library staff was encouraged to work from home, so student workers staffed the library’s physical locations during that time, leaving the VRS to be the only place where patrons could get expert help. The VRS had an increase of 65% of questions asked between spring term 2019 and spring term 2020. The VRS team had to navigate often complicated and fast-changing new routines depending on national guidelines. The VRS team has a strong emphasis on agility in their approach to the challenges and opportunities, with methods to evaluate decisions regularly with user experience in mind. Fast decision-making, collecting feedback, an open-minded approach to reviewing rules and processes with both a short-term and a long-term focus and providing a healthy work environment have been key factors in managing this crisis and learn from it. This was resting on a strong sense of ownership regarding the VRS, well-working communication tools and agile and active communication between team members, as well as between the team and the rest of the organization who served as a second-line support system to aid the VRS team. Moving forward, the VRS has become an important space for communication, interaction and provider of infrastructure, implementing new routines and more extensive availability due to the lessons learned during crisis. The evaluation shows that the virtual environment has become an important addition to the physical spaces, existing in its own right but always in connection with and in relationship with the library structure as a whole. Thereby showing that the basis of human interaction stays the same while its form morphs and adapts to changes, thus leaving the virtual environment as a space of communication and infrastructure with unique opportunities for outreach and the potential to become a staple in patron’s education and learning.

Keywords: virtual reference service, leadership, digital infrastructure, research library

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3883 Design and Development of an Optimal Fault Tolerant 3 Degree of Freedom Robotic Manipulator

Authors: Ramish, Farhan Khalique Awan

Abstract:

Kinematic redundancy within the manipulators presents extended dexterity and manipulability to the manipulators. Redundant serial robotic manipulators are very popular in industries due to its competencies to keep away from singularities during normal operation and fault tolerance because of failure of one or more joints. Such fault tolerant manipulators are extraordinarily beneficial in applications where human interference for repair and overhaul is both impossible or tough; like in case of robotic arms for space programs, nuclear applications and so on. The design of this sort of fault tolerant serial 3 DoF manipulator is presented in this paper. This work was the extension of the author’s previous work of designing the simple 3R serial manipulator. This work is the realization of the previous design with optimizing the link lengths for incorporating the feature of fault tolerance. Various measures have been followed by the researchers to quantify the fault tolerance of such redundant manipulators. The fault tolerance in this work has been described in terms of the worst-case measure of relative manipulability that is, in fact, a local measure of optimization that works properly for certain configuration of the manipulators. An optimum fault tolerant Jacobian matrix has been determined first based on prescribed null space properties after which the link parameters have been described to meet the given Jacobian matrix. A solid model of the manipulator was then developed to realize the mathematically rigorous design. Further work was executed on determining the dynamic properties of the fault tolerant design and simulations of the movement for various trajectories have been carried out to evaluate the joint torques. The mathematical model of the system was derived via the Euler-Lagrange approach after which the same has been tested using the RoboAnalyzer© software. The results have been quite in agreement. From the CAD model and dynamic simulation data, the manipulator was fabricated in the workshop and Advanced Machining lab of NED University of Engineering and Technology.

Keywords: fault tolerant, Graham matrix, Jacobian, kinematics, Lagrange-Euler

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3882 Challenges of Strategies for Improving Sustainability in Urban Historical Context in Developing Countries: The Case of Shiraz Bein Al-Haramein

Authors: Amir Hossein Ashari, Sedighe Erfan Manesh

Abstract:

One of the problems in developing countries is renovating the historical context and inducing behaviors appropriate to modern life to such a context. This study was conducted using field and library methods in 2012. Similar cases carried out in Iran and developing countries were compared to unveil the strengths and weaknesses of these projects. At present, in the historical context of Shiraz, the distance between two religious shrines of Shahcheragh (Ahmad ibn Musa) and Astaneh (Sayed Alaa al-Din Hossein), which are significant places in religious, cultural, social, and economic terms, is an area full of historic places called Bein Al-Haramein. Unfortunately, some of these places have been worn out and are not appropriate for common uses. The basic strategy of Bein Al-Haramein was to improve social development of Shiraz, to enhance the vitality and dynamism of the historical context of Bein Al-Haramein and to create tourist attractions in order to boost the city's economic and social stability. To this end, the project includes the huge Bein Al-Haramein Commercial Complex which is under construction now. To construct the complex, officials have decided to demolish places of historical value which can lead to irreparable consequences. Iranian urban design has always been based on three elements of bazaars, mosques and government facilities with bazaars being the organic connector of the other elements. Therefore, the best strategy in the above case is to provide for a commercial connection between the two poles. Although this strategy is included in the project, lack of attention to renovation principles in this area and complete destruction of the context will lead to its irreversible damage and will destroy its cultural and historical identity. In urban planning of this project, some important issues have been neglected including: preserving valuable buildings and special old features of the city, rebuilding worn buildings and context to attract trust and confidence of the people, developing new models according to changes, improving the structural position of old context with minimal degradation, attracting partnerships of residents and protecting their rights and finally using potential facilities of the old context. The best strategy for achieving sustainability in Bein Al-Haramein can be the one used in the distance between Santa Maria Novella and Santa Maria Del Fiore churches in historical context where while protecting the historic context and constructions, old buildings were renovated and given different commercial and service uses making them sustainable and dynamic places. Similarly, in Bein Al-Haramein, renovating old constructions and monuments and giving different commercial and other uses to them can help improve the economic and social sustainability of the area.

Keywords: Bein Al-Haramein, sustainability, historical context, historical context

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3881 Investigating the Public’s Perceptions and Factors Contributing to the Management of Household Solid Waste in Rural Communities: A Case Study of Two Contrasting Rural Wards in the Greater Tzaneen Municipality

Authors: Dimakatso Machetele, Clare Kelso, Thea Schoeman

Abstract:

In developing countries such as India, China, and South Africa, disposal of household solid waste in rural areas is of great concern. Rural communities face numerous challenges that include the absence of waste collection services and sanitation facilities. The inadequate provision of waste collection and sanitation services results to the occurrence of infectious diseases e.g., malaria. The gap in the management of household solid waste between rural and urban communities, whereby urban communities have better waste management services compared to rural areas is an environmental injustice towards rural communities. The unequal distribution of infrastructure in South Africa’s waste management is a concern that stems from the spatial inequalities of the country’s apartheid history. The Limpopo province has a higher proportion of households without waste collection services from the municipality. The present research objectives are to investigate the public’s perceptions and factors contributing to the management of household solid waste in two contrasting rural Wards in the Greater Tzaneen Municipality. There is limited data and studies that have been conducted to understand the management of household solid waste in rural areas, and specifically, for the Greater Tzaneen Municipality located in the Limpopo province, South Africa. The findings of the study will propose recommendations to the Greater Tzaneen Municipality, rural municipalities in South Africa, and globally to explore sustainable methods to manage household solid waste and explore economic opportunities within the waste management sector to alleviate poverty in rural communities.

Keywords: rural, household solid wase, perceptions, waste management

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3880 RPM-Synchronous Non-Circular Grinding: An Approach to Enhance Efficiency in Grinding of Non-Circular Workpieces

Authors: Matthias Steffan, Franz Haas

Abstract:

The production process grinding is one of the latest steps in a value-added manufacturing chain. Within this step, workpiece geometry and surface roughness are determined. Up to this process stage, considerable costs and energy have already been spent on components. According to the current state of the art, therefore, large safety reserves are calculated in order to guarantee a process capability. Especially for non-circular grinding, this fact leads to considerable losses of process efficiency. With present technology, various non-circular geometries on a workpiece must be grinded subsequently in an oscillating process where X- and Q-axis of the machine are coupled. With the approach of RPM-Synchronous Noncircular Grinding, such workpieces can be machined in an ordinary plung grinding process. Therefore, the workpieces and the grinding wheels revolutionary rate are in a fixed ratio. A non-circular grinding wheel is used to transfer its geometry onto the workpiece. The authors use a worldwide unique machine tool that was especially designed for this technology. Highest revolution rates on the workpiece spindle (up to 4500 rpm) are mandatory for the success of this grinding process. This grinding approach is performed in a two-step process. For roughing, a highly porous vitrified bonded grinding wheel with medium grain size is used. It ensures high specific material removal rates for efficiently producing the non-circular geometry on the workpiece. This process step is adapted by a force control algorithm, which uses acquired data from a three-component force sensor located in the dead centre of the tailstock. For finishing, a grinding wheel with a fine grain size is used. Roughing and finishing are performed consecutively among the same clamping of the workpiece with two locally separated grinding spindles. The approach of RPM-Synchronous Noncircular Grinding shows great efficiency enhancement in non-circular grinding. For the first time, three-dimensional non-circular shapes can be grinded that opens up various fields of application. Especially automotive industries show big interest in the emerging trend in finishing machining.

Keywords: efficiency enhancement, finishing machining, non-circular grinding, rpm-synchronous grinding

Procedia PDF Downloads 272