Search results for: finite element formulation

Authors: S. Begum, T. Biswas, M. A. Islam

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The present research investigates the distribution and contamination of heavy metals in core sediments collected from three locations of the Sundarbans mangrove forest. In this research, quality of the analysis is evaluated by analyzing certified reference materials IAEA-SL-1 (lake sediment), IAEA-Soil-7, and NIST-1633b (coal fly ash). Total concentrations of 28 heavy metals (Na, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, Ga, As, Sb, Cs, La, Ce, Sm, Eu, Tb, Dy, Ho, Yb, Hf, Ta, Th, and U) have determined in core sediments of the Sundarbans mangrove by neutron activation analysis (NAA) technique. When compared with upper continental crustal (UCC) values, it is observed that mean concentrations of K, Ti, Zn, Cs, La, Ce, Sm, Hf, and Th show elevated values in the research area is high. In this research, the assessments of metal contamination levels using different environmental contamination indices (EF, Igeo, CF) indicate that Ti, Sb, Cs, REEs, and Th have minor enrichment of the sediments of the Sundarbans. The modified degree of contamination (mCd) of studied samples of the Sundarbans ecosystem show low contamination. The pollution load index (PLI) values for the cores suggested that sampling points are moderately polluted. The possible sources of the deterioration of the sediment quality can be attributed to the different chemical carrying cargo accidents, port activities, ship breaking, agricultural and aquaculture run-off of the area. Pearson correlation matrix (PCM) established relationships among elements. The PCM indicates that most of the metal's distributions have been controlled by the same factors such as Fe-oxy-hydroxides and clay minerals, and also they have a similar origin. The poor correlations of Ca with most of the elements in the sediment cores indicate that calcium carbonate has a less significant role in this mangrove sediment. Finally, the data from this research will be used as a benchmark for future research and help to quantify levels of metal pollutions, as well as to manage future ecological risks of the vulnerable mangrove ecosystem, the Sundarbans.

Keywords: contamination, core sediment, trace element, sundarbans, vulnerable

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Authors: Daryl Clement Knutt, Neela Badrie, Marsha Singh

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Quality assurance and product labelling are vital in the food and drink industry, as a tactical tool in a competitive environment. The food label is a principal marketing tool which also serves as a regulatory mechanism in the safeguarding of consumer well –being. The objective of this study was to evaluate the level of consumers’ use and understanding of food labeling information and knowledge pertaining to food quality assurance systems. The study population consisted of Trinidadian adults, who were over the age of 18 (n=384). Data collection was conducted via a self-administered questionnaire, which contained 31 questions, comprising of four sections: I. socio demographic information; II. food quality and quality assurance; III. use of Labeling information; and IV. laws and regulations. Sampling was conducted at six supermarkets, in five major regions of the country over a period of three weeks in 2014. The demographic profile of the shoppers revealed that majority was female (63.6%). The gender factor and those who were concerned about the nutrient content of their food, were predictive indicators of those who read food labels. Most (93.1%) read food labels before purchase, 15.4% ‘always’; 32.5% ‘most times’ and 45.2% ‘sometimes’. Some (42%) were often satisfied with the information presented on food labels, whilst 35.7% of consumers were unsatisfied. When the respondents were questioned on their familiarity with terms ‘food quality’ and ‘food quality assurance’, 21.3% of consumers replied positively - ‘I have heard the terms and know a lot’ whilst 37% were only ‘somewhat familiar’. Consumers were mainly knowledgeable of the International Standard of Organization (ISO) (51.5%) and Good Agricultural Practices GAP (38%) as quality tools. Participants ranked ‘nutritional information’ as the number one labeling element that should be better presented, followed by ‘allergy notes’ and ‘best before date’. Females were more inclined to read labels being the household shoppers. The shoppers would like better presentation of the food labelling information so as to guide their decision to purchase a product.

Keywords: food labels, food quality, nutrition, marketing, Trinidad, Tobago

Procedia PDF Downloads 487

Authors: M. S. Sulaiman, N. Hassan, M. A. Aziz, M. S. A. Haron, J. H. A. Halim

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The classic profile of heritage clay roof tiles gives unique characteristics and timeless style to the almost historical building. It is not only designed to meet basic construction needs, offering great performance and durability but also highlights unnoticed stamp impressions, known as ‘insignia imprinted.’ It seems that the insignia imprinted is not significant to all stakeholders, especially in preserving heritage clay roof tiles in Malaysia. They are not even realized the existence and importance of that element, where it represents the cognitive and social character of that particular era. It creates a sense of belongings for the manufacturers regarding their most elementary features, such as a fortress, crown, fauna and etc. This research aims to identify and analyze the late stamp marks on heritage interlocking clay roof tiles in a government heritage building in Malaysia. The methodology used is literature reviews (desktop study), observation on sites, and interviews. Initial findings from the preliminary observation on-site in Peninsular Malaysia show some evidence that the stamp marks appear on the front and back sides of the tile that indicates the year, manufacturer, code numbers, and logos. Almost more than 30 samples of different types of stamp marks were found and collected. Some of which had been described Guichard & Carvin Cie Marsielle St Andre France, Pierre Sacoman St Henry Marsielle, Tuileries Aixoises Les Milles B.D.R France, The Calicut Tile Co Feroke, And B. Pinto & Co Mangalore dated 1865, 1919 and 1936. In view of this abundance of materials, it will lead to the establishment of a comprehensive database consisting of detailed specifications and material performance for future conservation works and maintenance purposes that will sustain for future references.

Keywords: clay roof tiles, insignia imprinted, interlocking, stamp mark

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Authors: Alexander Otchere Fianko, Clement Yeboah, Evans Oteng

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Prior research concludes that Green Procurement Practices positively drive Organisational Performance. Nonetheless, the nexus and conditions under which Green Procurement Practices contribute to a Firm’s Performance are less understood. The purpose of this quantitative relational study was to examine the relationship between Green Procurement Practices and 500 Firms’ Performances in Ghana. The researchers further seek to draw insights from the resource-based view to conceptualize Green Procurement Practices and Environmental Commitment as resource capabilities to enhance Firm Performance. The researchers used insights from the contingent resource-based view to examine Green Leadership Orientation conditions under which Green Procurement Practices contribute to Firm Performance through Environmental Commitment Capabilities. The study’s conceptual framework was tested on primary data from some firms in the Ghanaian market. PROCESS Macro was used to test the study’s hypotheses. Beyond that, Environmental Commitment Capabilities mediated the association between Green Procurement Practices and the Firm’s Performance. The study further seeks to find out whether Green Leadership Orientation positively moderates the indirect relationship between Green Procurement Practices and Firm Performance through Environmental Commitment Capabilities. While conventional wisdom suggests that improved Green Procurement Practices help improve a Firm’s Performance, this study tested this presumed relationship between Green Procurement Practices and Firm Performance and provides theoretical arguments and empirical evidence to justify how Environmental Commitment Capabilities uniquely and in synergy with Green Leadership Orientation transform this relationship. The study results indicated a positive correlation between Green Procurement Practices and Firm Performance. This result suggests that firms that prioritize environmental sustainability and demonstrate a strong commitment to environmentally responsible practices tend to experience better overall performance. This includes financial gains, operational efficiency, enhanced reputation, and improved relationships with stakeholders. The study's findings inform policy formulation in Ghana related to environmental regulations, incentives, and support mechanisms. Policymakers can use the insights to design policies that encourage and reward firms for their Green Procurement Practices, thereby fostering a more sustainable and environmentally responsible business environment. The findings from such research can influence the design and development of educational programs in Ghana, specifically in fields related to sustainability, environmental management, and corporate social responsibility (CSR). Institutions may consider integrating environmental and sustainability topics into their business and management courses to create awareness and promote responsible practices among future business professionals. Also, the study results can also promote the adoption of environmental accounting practices in Ghana. By recognizing and measuring the environmental impacts and costs associated with business activities, firms can better understand the financial implications of their Green Procurement Practices and develop strategies for improved performance.

Keywords: environmental commitment, firm’s performance, green procurement practice, green leadership orientation

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Authors: Jamil Hijazi, Stirling Howieson

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Over one-quarter of the Kingdom of Saudi Arabia’s total oil production (2.8 million barrels a day) is used for electricity generation. The built environment is estimated to consume 77% of the total energy production. Of this amount, air conditioning systems consume about 80%. Apart from considerations surrounding global warming and CO2 production it has to be recognised that oil is a finite resource and the KSA like many other oil rich countries will have to start to consider a horizon where hydro-carbons are not the dominant energy resource. The employment of hybrid ground cooling pipes in combination with black body solar collection and radiant night cooling systems may have the potential to displace a significant proportion of oil currently used to run conventional air conditioning plant. This paper presents an investigation into the viability of such hybrid systems with the specific aim of reducing carbon emissions while providing all year round thermal comfort in a typical Saudi Arabian urban housing block. At the outset air and soil temperatures were measured in the city of Jeddah. A parametric study then was carried out by computational simulation software (Design Builder) that utilised the field measurements and predicted the cooling energy consumption of both a base case and an ideal scenario (typical block retro-fitted with insulation, solar shading, ground pipes integrated with hypocaust floor slabs/ stack ventilation and radiant cooling pipes embed in floor).Initial simulation results suggest that careful ‘ecological design’ combined with hybrid radiant and ground pipe cooling techniques can displace air conditioning systems, producing significant cost and carbon savings (both capital and running) without appreciable deprivation of amenity.

Keywords: energy efficiency, ground pipe, hybrid cooling, radiative cooling, thermal comfort

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Authors: Robert Kwame Kpaliba, Dennis Kpakpor Adotey, Yaw Serfor-Armah

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Increase in the oceanic carbon dioxide absorbance from the atmosphere due to climate change has led to appreciable change in the chemistry of the oceans. The change in oceanic pH referred to as ocean acidification poses multiple threats and stresses on marine species, biodiversity, goods and services, and livelihoods. Marine ecosystems are continuously threatened by plethora of natural and anthropogenic stressors including carbon dioxide (CO₂) emissions causing a lot of changes which has not been experienced for approximately 60 years. Little has been done in Africa as a whole and Ghana in particular to improve the understanding of the variations of the carbonate chemistry of seawater and the biophysical impacts of ocean acidification on security of seafood, nutrition, climate and environmental change. There is, therefore, the need for regular monitoring of carbonate chemistry of seawater along Ghana’s coastline to generate reliable data to aid marine policy formulation. Samples of seawater were collected thrice every month for a one-year period from five study sites for the various parameters to be analyzed. Analysis of the measured physico-chemical and the carbonate chemistry parameters was done using simple statistics. Correlation test and ANOVA were run on both of the physico-chemical and carbonate chemistry parameters. The carbonate chemistry parameters were measured using computer software programme (CO₂cal v4.0.9) except total alkalinity and pH. The study assessed the variability of seawater carbonate chemistry in selected portions of the Central Atlantic Coastline of Ghana (Tsokomey/Bortianor, Kokrobitey, Gomoa Nyanyanor, Gomoa Fetteh, and Senya Breku landing beaches) over a 1-year period (June 2016–May 2017). For physico-chemical parameters, there was insignificant variation in nitrate (NO₃⁻) (1.62 - 2.3 mg/L), ammonia (NH₃) (1.52 - 2.05 mg/L), and salinity (sal) (34.50 - 34.74 ppt). Carbonate chemistry parameters for all the five study sites showed significant variation: partial pressure of carbon dioxide (pCO₂) (414.08-715.5 µmol/kg), carbonate ion (CO₃²⁻) (115-157.92 µmol/kg), pH (7.9-8.12), total alkalinity (TA) (1711.8-1986 µmol/kg), total carbon dioxide (TCO₂) (1512.1 - 1792 µmol/kg), dissolved carbon dioxide (CO₂aq) (10.97-18.92 µmol/kg), Revelle Factor (RF) (9.62-11.84), aragonite (ΩAr) (0.75-1.48) and calcite (ΩCa) (1.08-2.14). The study revealed that the partial pressure of carbon dioxide and temperature did not have a significant effect on each other (r² = 0.31) (p-value = 0.0717). There was an appreciable effect of pH on dissolved carbon dioxide (r² = 0.921) (p-value = 0.0000). The variation between total alkalinity and dissolved carbon dioxide was appreciable (r² = 0.731) (p-value = 0.0008). There was a significant correlation between total carbon dioxide and dissolved carbon dioxide (r² = 0.852) (p-value = 0.0000). Revelle factor correlated strongly with dissolved carbon dioxide (r² = 0.982) (p-value = 0.0000). Partial pressure of carbon dioxide corresponds strongly with atmospheric carbon dioxide (r² = 0.9999) (p-value = 0.00000).

Keywords: carbonate chemistry, seawater, central atlantic coastline, Ghana, ocean acidification

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Authors: Hasibul Kabir, Samin Shahriar Tokey, Md. Tofazzal Hossain

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One of the most necessary things in the present time is raising social awareness about global warming and climate change among the people. Though many types of mediums and techniques have been used to teach people about this global phenomenon, there are still more effective ways to reach people with useful information about global warming. As many traditional methods to teach people about global warming and climate change did not work well, video games were overdue. To learn how effective a video game can be in this regard, we developed a Video game, "Historia's Nightmare," that teaches people about Global warming and climate change. The game was designed to entertain people and give them an idea about the reasons and consequences of global warming and climate change while not being like traditional educational games. The game threw a mini quiz consisting of two MCQs based on the information shown in the game, where a gamer had to pass the quiz to reach the next level. We published the game on different platforms to let all types of people play and complete our experiment effectively. The game continuously communicated with our server to send data about gamers' performance. We observed the data, including the participants' performance, time spent, quiz score, and the in-game feedback on a regular basis, and finally came to a verdict. In our experiment, we have found that most participants positively accepted the game and learned something new. The participants who spent more on our game performed better in both quiz and the game. Our experiment's result demonstrates that video games can be a great way to teach people something, particularly to raise social awareness about global warming and climate change. It also demonstrates that the game can be a significant element in education and learning improvement.

Keywords: video game, global warming, social awareness, climate change, education, feedback

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Authors: Maliheh Raji, Hossein Abolghasemi, Jaber Safdari, Ali Kargari

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Samarium as a rare-earth element is playing a growing important role in high technology. Traditional methods for extraction of rare earth metals such as ion exchange and solvent extraction have disadvantages of high investment and high energy consumption. Emulsion liquid membrane (ELM) as an improved solvent extraction technique is an effective transport method for separation of various compounds from aqueous solutions. In this work, the extraction of samarium from aqueous solutions by ELM was investigated using response surface methodology (RSM). The organic membrane phase of the ELM was a nanofluid consisted of multiwalled carbon nanotubes (MWCNT), Span80 as surfactant, Cyanex 272 as mobile carrier, and kerosene as base fluid. 1 M nitric acid solution was used as internal aqueous phase. The effects of the important process parameters on samarium extraction were investigated, and the values of these parameters were optimized using the Central Composition Design (CCD) of RSM. These parameters were the concentration of MWCNT in nanofluid, the carrier concentration, and the volume ratio of organic membrane phase to internal phase (Roi). The three-dimensional (3D) response surfaces of samarium extraction efficiency were obtained to visualize the individual and interactive effects of the process variables. A regression model for % extraction was developed, and its adequacy was evaluated. The result shows that % extraction improves by using MWCNT nanofluid in organic membrane phase and extraction efficiency of 98.92% can be achieved under the optimum conditions. In addition, demulsification was successfully performed and the recycled membrane phase was proved to be effective in the optimum condition.

Keywords: Cyanex 272, emulsion liquid membrane, MWCNT nanofluid, response surface methology, Samarium

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Authors: M. Mohan, J. P. Roise, G. P. Catts

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Despite living in an era where conservation zones are de-facto the central element in any sustainable wildlife management strategy, we still find ourselves grappling with several pareto-optimal situations regarding resource allocation and area distribution for the same. In this paper, a multi-objective decision making (MODM) model is presented to answer the question of whether or not we can establish mutual relationships between these contradicting objectives. For our study, we considered a Red-cockaded woodpecker (Picoides borealis) habitat conservation scenario in the coastal plain of North Carolina, USA. Red-cockaded woodpecker (RCW) is a non-migratory territorial bird that excavates cavities in living pine trees for roosting and nesting. The RCW groups nest in an aggregation of cavity trees called ‘cluster’ and for our model we use the number of clusters to be established as a measure of evaluating the size of conservation zone required. The case study is formulated as a linear programming problem and the objective function optimises the Red-cockaded woodpecker clusters, carbon retention rate, biofuel, public safety and Net Present Value (NPV) of the forest. We studied the variation of individual objectives with respect to the amount of area available and plotted a two dimensional dynamic graph after establishing interrelations between the objectives. We further explore the concept of interdependency by integrating the MODM model with GIS, and derive a raster file representing carbon distribution from the existing forest dataset. Model results demonstrate the applicability of interdependency from both linear and spatial perspectives, and suggest that this approach holds immense potential for enhancing environmental investment decision making in future.

Keywords: conservation, interdependency, multi-objective decision making, red-cockaded woodpecker

Procedia PDF Downloads 336

Authors: Shaher Bano, Samia Fida, Asif Israr

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The continuous development and exploitation of materials and designs have diverted the attention of the world towards the use of robust composite materials known as fiber-metal laminates in many high-performance applications. The hybrid structure of fiber metal laminates makes them a material of choice for various applications such as aircraft skin panels, fuselage floorings, door panels and other load bearing applications. The synergistic effect of properties of metals and fibers reinforced laminates are responsible for their high damage tolerance as the metal element provides better fatigue and impact properties, while high stiffness and better corrosion properties are inherited from the fiber reinforced matrix systems. They are mostly used as a layered structure in different joint configurations such as lap and but joints. The FML layers are usually bonded with each other using either mechanical fasteners or adhesive bonds. This research work is also focused on modification of an adhesive bonded joint as a single lap joint of carbon fibers based CARALL FML has been modified to increase interlaminar shear strength and avoid delamination. For this purpose different joint modification techniques such as the introduction of spews and shoulder to modify the bond shape and use of nanofillers such as carbon nano-tubes as a reinforcement in the adhesive materials, have been utilized to improve shear strength of lap joint of the adhesively bonded FML layers. Both the simulation and experimental results showed that lap joint with spews and shoulders configuration have better properties due to stress distribution over a large area at the corner of the joint. The introduction of carbon nanotubes has also shown a positive effect on shear stress and joint strength as they act as reinforcement in the adhesive bond material.

Keywords: adhesive joint, Carbon Reinforced Aluminium Laminate (CARALL), fiber metal laminates, spews

Procedia PDF Downloads 297

Authors: Elvira Lumi, Hans Jazxhi

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In the works of the writer Flutura Açka, the play with these questions is acute, and in almost each of them, the act of loneliness and isolation builds in a completely involuntary way unique and frequent conceptual spaces. Because the object of study is too broad to grasp all the works, this study lays out a rapid paradox of our access to three of the novels in the line of numerous authorial works. The novel "Woman Loneliness" (2001), also marked as the first work in prose by the author, declares in the title the paradigm of what she has decided to confess. The gender segregation proclaimed in the title will be revealed step by step in the work as conventional human segregation without gender. In this novel, the analysis of the state of "loneliness" will require a contemplation beyond man, when the role of the environment and the distance from the center of the narrative base will be extremely visible in the work. The novel "Cross of Oblivion" (2004) has another form of perception of loneliness, which, unlike the one built by the characters themselves in the novel "Woman Loneliness," is imposed and obligatory to live by the circumstances. Its characters are trapped in loneliness, as loneliness that comes from impossibility, from the past, from dependence on fate, from fear of change, and from the obligation to accept it. At the heart of the novel, the plot of the novel game is dictated by the Kanun and its rules and the loneliness of the basis of life in unbroken waves towards the periphery of the event, a periphery that has very large geography and is played in today's Europe. The novel "Where are you?" (2009) has a completely different form of constructing the concept of loneliness and isolation that comes under conditions of repression and political pressure. The loneliness in this novel takes the form of the protective element from the circumstances that actually require a social inclusion; it is personal loneliness that ensures relative mental health of the characters, up to a new trap created by the circumstances, thus building life fragmentary “healthy” in the order of a mentally ill and socially ill society.

Keywords: loneliness, existential, isolation, woman, prose

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Authors: Vidhya Venugopal, Rekha S.

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Introduction: Climate change and the growing frequency of higher average temperatures and heat waves have detrimental health effects, especially for certain vulnerable groups with limited socioeconomic status (SES) or physiological capacity to adapt to or endure high temperatures. Little research has been conducted on the effects of heat stress on pregnant women and fetuses in tropical regions such as India. Very high ambient temperatures may worsen Adverse Pregnancy Outcomes (APOs) and are a major worry in the scenario of climate change. The relationship between rising temperatures and APO must be better understood in order to design more effective interventions. Methodology: We conducted an observational cohort study involving 865 pregnant women in various districts of Tamil Nadu districts between 2014 and 2021. Physiological Heat Strain Indicators (HSI) such as morning and evening Core Body Temperature (CBT) and Urine Specific Gravity (USG) were monitored using an infrared thermometer and refractometer, respectively. A validated, modified version of the HOTHAPS questionnaire was utilised to collect self-reported health symptoms. A follow-up was undertaken with the mothers to collect information regarding birth outcomes and APOs, such as spontaneous abortions, stillbirths, Preterm Birth (PTB), birth abnormalities, and Low Birth Weight (LBW). Major findings of the study: According to the findings of our study, ambient temperatures (mean WBGT°C) were substantially higher (>28°C) for approximately 46% of women performing moderate daily life activities. 82% versus 43% of these women experienced dehydration and heat-related complaints. 34% of women had USG >1.020, which is symptomatic of dehydration. APOs, which include spontaneous abortions, were prevalent at 2.2%, stillbirth/preterm birth/birth abnormalities were prevalent at 2.2%, and low birth weight was prevalent at 16.3%. With exposures to WBGT>28°C, the incidence of miscarriage or unexpected abortion rose by approximately 2.7 times (95% CI: 1.1-6.9). In addition, higher WBGT exposures were associated with a 1.4-fold increased risk of unfavorable birth outcomes (95% Confidence Interval [CI]: 1.02-1.09). The risk of spontaneous abortions was 2.8 times higher among women who conceived during the hotter months (February – September) compared to those women who conceived in the cooler months (October – January) (95% CI: 1.04-7.4). Positive relationships between ambient heat and APOs found in this study necessitate further exploration into the underlying factors for extensive cohort studies to generate information to enable the formulation of policies that can effectively protect these women against excessive heat stress for enhanced maternal and fetal health.

Keywords: heat exposures, community, pregnant women, physiological strain, adverse outcome, interventions

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Authors: Tew Leh Ghee

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The study's goal is to determine how celebrity endorsement affects Malaysian consumers' attitudes and intentions to buy skincare products. Since customers now largely rely on celebrity endorsement to influence purchasing decisions in almost every business, celebrity endorsement is not, in reality, a new phenomenon. Even though the market for skincare products has a vast potential to be exploited, corporations have yet to seize this niche via celebrity endorsement. Basically, there hasn't been much study done to recognize the significance of celebrity endorsement in this industry. This research combined descriptive and quantitative methods with a self-administered survey as the primary data-gathering tool. All of the characteristics under study were measured using a 5-point Likert scale, and the questionnaire was written in English. A convenience sample method was used to choose respondents, and 360 sets of valid questionnaires were gathered for the study's statistical analysis. Preliminary statistical analyses were analyzed using SPSS version 20.0 (Statistical Package for the Social Sciences). The backdrop of the respondents' demographics was examined using descriptive analysis. All concept assessments' validity and reliability were examined using exploratory factor analysis, item-total statistics, and reliability statistics. Pearson correlation and regression analysis were used, respectively, to assess relationships and impacts between the variables under study. The research showed that, apart from competence, celebrity endorsements of skincare products in Malaysia had a favorable impact on attitudes and purchase intentions as evaluated by attractiveness and dependability. The research indicated that the most significant element influencing attitude and buy intention was the credibility of a celebrity endorsement. The study offered implications in order to provide potential improvements of celebrity endorsement in skincare goods in Malaysia. The study's last portion includes its limits and ideas for the future.

Keywords: trustworthiness, influential, phenomenon, celebrity emdorsement

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Authors: Areej Isam Barham

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Developing students’ number sense is an essential element in the learning of mathematics. Number sense is one of the foundational ideas in mathematics where students need to understand numbers, representing them in different ways, and realize the relationships among numbers. Number sense also reflects students’ understanding of the meaning of operations, how they related to one another, how to compute fluently and make reasonable estimates. Developing students’ number sense in the mathematics classroom requires good preparation for mathematics teachers, those who will direct their students towards the real understanding of numbers and its implementation in the learning of mathematics. This study describes the development of elementary prospective mathematics teachers’ number sense through a mathematics teaching methods course at Qatar University. The study examined the effect of using the Lesh model in enhancing mathematics prospective teachers’ number sense. Thirty-nine elementary prospective mathematics teachers involved in the current study. The study followed an experimental research approach, and quantitative research methods were used to answer the research questions. Pre-post number sense test was constructed and implemented before and after teaching by using the Lesh model. Data were analyzed using Statistical Packages for Social Sciences (SPSS). Descriptive data analysis and t-test were used to examine the impact of using the Lesh model in enhancing prospective teachers’ number sense. Finding of the study indicated poor number sense and limited numeracy skills before implementing the use of the Lesh model, which highly demonstrate the importance of the study. The results of the study also revealed a positive impact on the use of the Lesh model in enhancing prospective teachers’ number sense with statistically significant differences. The discussion of the study addresses different features and issues related to the participants’ number sense. In light of the study, the research presents recommendations and suggestions for the future development of mathematics prospective teachers’ number sense.

Keywords: number sense, Lesh model, prospective mathematics teachers, development of number sense

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Authors: Suneet Jagdev

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Rapid urbanization has resulted in informal settlements on the periphery of nearly all big cities in the developing world due to lack of affordable housing options in the city. Residents of these communities have to travel long distances to get to work or search for jobs in these cities, and women, children and elderly people are excluded from urban opportunities. Affordable and safe public transport facilities can help them expand their possibilities. The aim of this research is to identify social capital as another important element of livable cities that can be protected and nurtured through transit-oriented development, as a tool to provide real resources that can help these transit-oriented communities become self-sustainable. Social capital has been referred to the collective value of all social networks and the inclinations that arise from these networks to do things for each other. It is one of the key component responsible to build and maintain democracy. Public spaces, pedestrian amenities and social equity are the other essential part of Transit Oriented Development models that will be analyzed in this research. The data has been collected through the analysis of several case studies, the urban design strategies implemented and their impact on the perception and on the community´s experience, and, finally, how these focused on the social capital. Case studies have been evaluated on several metrics, namely ecological, financial, energy consumption, etc. A questionnaire and other tools were designed to collect data to analyze the research objective and reflect the dimension of social capital. The results of the questionnaire indicated that almost all the participants have a positive attitude towards this dimensions of building a social capital with the aid of transit-oriented development. Statistical data of the identified key motivators against against demographic characteristics have been generated based on the case studies used for the paper. The findings suggested that there is a direct relation between urbanization, transit-oriented developments, and social capital.

Keywords: better opportunities, low-income settlements, social capital, social inclusion, transit oriented development

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Authors: Alex Fedoseyev

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This study explores Generalized Hydrodynamic Equations (GHE) for the simulation of turbulent flows. The GHE was derived from the Generalized Boltzmann Equation (GBE) by Alexeev (1994). GBE was obtained by first principles from the chain of Bogolubov kinetic equations and considered particles of finite dimensions, Alexeev (1994). The GHE has new terms, temporal and spatial fluctuations compared to the Navier-Stokes equations (NSE). These new terms have a timescale multiplier τ, and the GHE becomes the NSE when τ is zero. The nondimensional τ is a product of the Reynolds number and the squared length scale ratio, τ=Re*(l/L)², where l is the apparent Kolmogorov length scale, and L is a hydrodynamic length scale. The turbulence phenomenon is not well understood and is not described by NSE. An additional one or two equations are required for the turbulence model, which may have to be tuned for specific problems. We show that, in the case of the GHE, no additional turbulence model is needed, and the turbulent velocity profile is obtained from the GHE. The 2D turbulent channel and circular pipe flows were investigated using a numerical solution of the GHE for several cases. The solutions are compared with the experimental data in the circular pipes and 2D channels by Nicuradse (1932, Prandtl Lab), Hussain and Reynolds (1975), Wei and Willmarth (1989), Van Doorne (2007), theory by Wosnik, Castillo and George (2000), and the relevant experiments on Superpipe setup at Princeton, data by Zagarola (1996) and Zagarola and Smits (1998), the Reynolds number is from Re=7200 to Re=960000. The numerical solution data compared well with the experimental data, as well as with the approximate analytical solution for turbulent flow in channel Fedoseyev (2023). The obtained results confirm that the Alexeev generalized hydrodynamic theory (GHE) is in good agreement with the experiments for turbulent flows. The proposed approach is limited to 2D and 3D axisymmetric channel geometries. Further work will extend this approach by including channels with square and rectangular cross-sections.

Keywords: comparison with experimental data. generalized hydrodynamic equations, numerical solution, turbulent boundary layer, turbulent flow in channel

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Authors: Mohd Afif Md Nasir, Mohd Faizal Amin Nur, Jamaluddin Hasim, Abd Samad Hasan Basari, Mohd Halim Sahelan

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This study is aimed to investigate the suitability of Computer-Based Training (CBT) as one of the approaches in skills competency development at the Centre of Instructor and Advanced Skills Training (CIAST) Shah Alam Selangor and National Youth Skills Institute (NYSI) Pagoh Muar Johor. This study has also examined the perception among trainees toward Virtual Learning Environment (VLE) as to realize the development of skills in Welding Technology. The significance of the study is to create a computer-based skills development approach in welding technology among new trainees in CIAST and IKBN as well as to cultivate the element of general skills among them. This study is also important in elevating the number of individual knowledge workers (K-Workers) working in manufacturing industry in order to achieve the national vision which is to be an industrial nation in the year 2020. The design is a survey of research which using questionnaires as the instruments and is conducted towards 136 trainees from CIAST and IKBN. Data from the questionnaires is proceeding in a Statistical Package for Social Science (SPSS) in order to find the frequency, mean and chi-square testing. The findings of the study show the welding technology skills have developed in the trainees as a result of the application of the Virtual Reality simulator at a high level (mean=3.90) and the respondents agreed the skills could be embedded through the application of the Virtual Reality simulator (78.01%). The Study also found that there is a significant difference between trainee skill characteristics through the application of the Virtual Reality simulator (p<0.05). Thereby, the Virtual Reality simulator is suitable to be used in the development of welding skills among trainees through the skills training institute.

Keywords: computer-based training, virtual learning environment, welding technology, virtual reality simulator, virtual learning environment

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Authors: Rama Ajineh

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Neighborhoods are defined as local zones within settlements and cities recognized by individuals who live there, with their identities and given boundaries. Neighborhoods mainly structure individual’s lives, the small box which various social groups interact with each other, develop and become one strong entity. Also, it is a platform for more activities, providing many of the social services to enhance the connections between the people, giving a sense of community. However, some of these neighborhoods were unplanned and caused many social, economical and architectural problems to its residents in the first place, and to the city. A great example of such case is in Saudi Arabia, Jeddah, Al-Ruwais neighborhood, where the authority is planning to regenerate the area and make it a landmark for the city. Urban Regeneration of Unplanned Settlements is a process to make people live and work, now and in the future, and meet the various needs of the current and coming inhabitants, with a high-quality life for all. Through research, it was discovered that Urban regeneration plans on Al-Ruwais were planned regardless to the collective agreement of the inhabitants, giving themselves the absolute right to demolish and reconstruct the desired locations with a low compensation. Consequently, a deep research will be done on integrating the residents with the process, by showcasing examples of successful Urban Regenerations of Unplanned settlements in different cities. The research aims to understand the sustainable, and well-planned regeneration strategies used to enhance people’s living without harming them, and give sustainable urban solutions. Moreover, the research explores the definition of Sustainable Communities. The used methods in this paper are secondary research on site analysis and the relationship between the human and the neighborhood. The conclusion reveals the most successful fashion of Urban regeneration of Unplanned settlements and applies it to Al-Ruwais neighborhood considering the human factor as a primary element.

Keywords: architecture, human integration, original residents, site analysis, sustainable communities, urban sustainable solutions, urban regeneration

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Authors: Wegene Demeke

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Background: The demand for healthcare services is growing in developing and developed countries. Information and communication technology is used to facilitate healthcare services. In the case of developing countries, implementing telemedicine is aimed at providing healthcare for people living in remote areas where health service is not accessible. The implementations of telemedicine in developing countries are unsuccessful. For example, the recent study indicates that 90% of telemedicine projects are abandoned or failed in developing countries. Several researchers reported the technological challenges as the main factor for the non-adoption of telemedicine. However, this research reports the health professionals’ perspectives arising from technical, social and organizational factors that are considered as key elements for the setting and running of telemedicine in Ethiopia. The importance and significance of telemedicine for healthcare is growing. For example, the use of telemedicine in the current pandemic situation becomes an essential strategic element in providing healthcare services in developed countries. Method: Qualitative and quantitative exploratory research methods used to collect data to find factors affecting the adoption of Information and communication technologies for telemedicine use. The survey was distributed using emails and Google forms. The email addresses were collected from personal contact and publicly available websites in Ethiopia. The thematic analysis used to build the barriers and facilitators factors for establishing telemedicine services. A survey questionnaire with open-and-close questions was used to collect data from 175 health professionals. Outcome: The result of this research will contribute to building the key barriers and facilitators factors of telemedicine from the health professional perspectives in developing countries. The thematic analysis provides barriers and facilitators factors arising from technical, organizational, and social sources.

Keywords: telemedicine, ICT, developing country, Ethiopia, health service

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Authors: M. C. Pardo-Ferreira, J. C. Rubio-Romero, M. Martínez-Rojas

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Resilience Engineering is a new paradigm of safety management that proposes to change the way of managing the safety to focus on the things that go well instead of the things that go wrong. Many complex and high-risk sectors such as air traffic control, health care, nuclear power plants, railways or emergencies, have applied this new vision of safety and have obtained very positive results. In the construction sector, safety management continues to be a problem as indicated by the statistics of occupational injuries worldwide. Therefore, it is important to improve safety management in this sector. For this reason, it is proposed to apply Resilience Engineering to the construction sector. The Construction Phase Health and Safety Plan emerges as a key element for the planning of safety management. One of the key tools of Resilience Engineering is the Resilience Assessment Grid that allows measuring the four essential abilities (respond, monitor, learn and anticipate) for resilient performance. The purpose of this paper is to develop a questionnaire based on the Resilience Assessment Grid, specifically on the ability to learn, to assess whether a Construction Phase Health and Safety Plans helps companies in a construction site to implement this ability. The research process was divided into four stages: (i) initial design of a questionnaire, (ii) validation of the content of the questionnaire, (iii) redesign of the questionnaire and (iii) application of the Delphi method. The questionnaire obtained could be used as a tool to help construction companies to evolve from Safety-I to Safety-II. In this way, companies could begin to develop the ability to learn, which will serve as a basis for the development of the other abilities necessary for resilient performance. The following steps in this research are intended to develop other questions that allow evaluating the rest of abilities for resilient performance such as monitoring, learning and anticipating.

Keywords: resilience engineering, construction sector, resilience assessment grid, construction phase health and safety plan

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Authors: Durri Andriani, Irsan Tahar, Lilian Sarah Hiariey

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Every institution has to develop, implement, and control its policies to ensure the effectiveness of the institution. In doing so, all related stakeholders have to be involved to maximize the benefit of the policies and minimize the potential constraints and resistances. Open and distance education (ODE) institution is no different. As an education institution, ODE institution has to focus their attention to fulfilling academic needs of their students through open and distance measures. One of them is quality learning support system. Significant stakeholders in learning support system are tutors since they are the ones who directly communicate with students. Tutors are commonly seen as objects whose main responsibility is limited to implementing policies decided by management in ODE institutions. Nonetheless, tutors’ perceptions of tutorials are believed to influence tutors’ performances in facilitating learning support. It is therefore important to analyze tutors’ perception on various aspects of learning support. This paper presents analysis of tutors’ perceptions on policies of tutoriala in ODE institution using Policy Analysis Framework (PAF) modified by King, Nugent, Russell, and Lacy. Focus of this paper is on on-line tutors, those who provide tutorials via Internet. On-line tutors were chosen to stress the increasingly important used of Internet in ODE system. The research was conducted in Universitas Terbuka (UT), Indonesia. UT is purposely selected because of its large number (1,234) of courses offered and large area coverage (6000 inhabited islands). These posed UT in a unique position where learning support system has, to some extent, to be standardized while at the same time it has to be able to cater the needs of different courses in different places for students with different backgrounds. All 598 listed on-line tutors were sent the research questionnaires. Around 20% of the email addresses could not be reached. Tutors were asked to fill out open-ended questionnaires on their perceptions on definition of on-line tutorial, roles of tutors and students in on-line tutorials, requirement for on-line tutors, learning materials, and student evaluation in on-line tutorial. Data analyzed was gathered from 40 on-line tutors who sent back filled-out questionnaires. Data were analyzed qualitatively using content analysis from all 40 tutors. The results showed that using PAF as entry point in choosing learning support services as area of policy with delivery learning materials as the issue at UT has been able to provide new insights of aspects need to be consider in formulating policies in online tutorial and in learning support services. Involving tutors as source of information could be proven to be productive. In general, tutors had clear understanding about definition of online tutorial, roles of tutors and roles of students, and requirement of tutor. Tutors just need to be more involved in the policy formulation since they could provide data on students and problem faced in online tutorial. However, tutors need an adjustment in student evaluation which according tutors too focus on administrative aspects and subjective.

Keywords: distance education, on-line tutorial, tutorial policy, tutors’ perspectives

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Authors: Jeanne Leblond, Warren Viricel, Amira Mbarek

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Although several products have reached the market, gene therapeutics are still in their first stages and require optimization. It is possible to improve their lacking efficiency by the use of carefully engineered vectors, able to carry the genetic material through each of the biological barriers they need to cross. In particular, getting inside the cell is a major challenge, because these hydrophilic nucleic acids have to cross the lipid-rich plasmatic and/or endosomal membrane, before being degraded into lysosomes. It takes less than one hour for newly endocytosed liposomes to reach highly acidic lysosomes, meaning that the degradation of the carried gene occurs rapidly, thus limiting the transfection efficiency. We propose to use a new pH-sensitive lipid able to change its conformation upon protonation at endosomal pH values, leading to the disruption of the lipidic bilayer and thus to the fast release of the nucleic acids into the cytosol. It is expected that this new pH-sensitive mechanism promote endosomal escape of the gene, thereby its transfection efficiency. The main challenge of this work was to design a preparation presenting fast-responding lipidic bilayer destabilization properties at endosomal pH 5 while remaining stable at blood pH value and during storage. A series of pH-sensitive lipids able to perform a conformational switch upon acidification were designed and synthesized. Liposomes containing these switchable lipids, as well as co-lipids were prepared and characterized. The liposomes were stable at 4°C and pH 7.4 for several months. Incubation with siRNA led to the full entrapment of nucleic acids as soon as the positive/negative charge ratio was superior to 2. The best liposomal formulation demonstrated a silencing efficiency up to 10% on HeLa cells, very similar to a commercial agent, with a lowest toxicity than the commercial agent. Using flow cytometry and microscopy assays, we demonstrated that drop of pH was required for the transfection efficiency, since bafilomycin blocked the transfection efficiency. Additional evidence was brought by the synthesis of a negative control lipid, which was unable to switch its conformation, and consequently exhibited no transfection ability. Mechanistic studies revealed that the uptake was mediated through endocytosis, by clathrin and caveolae pathways, as reported for previous lipid nanoparticle systems. This potent system was used for the treatment of hypercholesterolemia. The switchable lipids were able to knockdown PCSK9 expression on human hepatocytes (Huh-7). Its efficiency is currently evaluated on in vivo mice model of PCSK9 KO mice. In summary, we designed and optimized a new cationic pH-sensitive lipid for gene delivery. Its transfection efficiency is similar to the best available commercial agent, without the usually associated toxicity. The promising results lead to its use for the treatment of hypercholesterolemia on a mice model. Anticancer applications and pulmonary chronic disease are also currently investigated.

Keywords: liposomes, siRNA, pH-sensitive, molecular switch

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Authors: Konrad Pietrykowski, Michal Bialy, Pawel Karpinski, Radoslaw Maczka

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The nozzle is an element of the rocket engine in which the conversion of the potential energy of gases generated during combustion into the kinetic energy of the gas stream takes place. The design parameters of the nozzle have a decisive influence on the ballistic characteristics of the engine. Designing a nozzle assembly is, therefore, one of the most responsible stages in developing a rocket engine design. The paper presents the results of the simulation of three types of rocket propulsion nozzles. Calculations were made using CFD (Computational Fluid Dynamics) in ANSYS Fluent software. The next types of nozzles differ in shape. The analysis was made of a conical nozzle, a bell type nozzle with a conical supersonic part and a bell type nozzle. Calculation results are presented in the form of pressure, velocity and kinetic energy distributions of turbulence in the longitudinal section. The courses of these values along the nozzles are also presented. The results show that the cone nozzle generates strong turbulence in the critical section. Which negatively affect the flow of the working medium. In the case of a bell nozzle, the transformation of the wall caused the elimination of flow disturbances in the critical section. This reduces the probability of waves forming before or after the trailing edge. The most sophisticated construction is the bell type nozzle. It allows you to maximize performance without adding extra weight. The bell type nozzle can be used as a starter and auxiliary engine nozzle due to its advantages. The project/research was financed in the framework of the project Lublin University of Technology-Regional Excellence Initiative, funded by the Polish Ministry of Science and Higher Education (contract no. 030/RID/2018/19).

Keywords: computational fluid dynamics, nozzle, rocket engine, supersonic flow

Procedia PDF Downloads 157

Authors: Ali Berk Bozan, Reşat Atalay Oyguç

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The demand for precast reinforced concrete (RC) structures is growing, considering their certain benefits, including faster assembly, homogeneous materials, and high-quality labor. The structural integrity of precast reinforced concrete (RC) constructions is influenced by the effectiveness of the joints and connections. This paper contains an analytical study about four types of precast reinforced concrete frames, which vary according to the number of storeys and the number of bays with two different types of moment-resisting beam-to-column connection is investigated under cyclic displacement loading up to 5.6% drift rate by using ABAQUS software. The first connection type is the widely used moment-resisting connection that is defined as a wet connection in the Turkish Seismic Code (TBDY). The second connection type is known as Artificial Controllable Plastic Hinge. The goal of this connection is to defend reinforced concrete components from earthquake-related plastic deformations by keeping them in a specialized connecting section. It will be possible to repair the broken connections after the earthquake. The cyclic behavior of the four types of frames with the mechanical plastic hinge and wet connection was analytically investigated, and then comparisons and suggestions were made on period, ductility, and structural system behavior coefficient. The analytical study shows that the replaceable plastic hinge element provides a significant period increase. Especially in the case of two storeys and two bays, the change in the period was felt the most compared to other frames. The results for ductility show a significant change in the ductility of the frames with replaceable plastic hinges. For the structural system behavior coefficient, a recommendation between 3.90 and 4.52 values was made.

Keywords: precast structures, replaceable plastic hinge, beam to column connections, ductility

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Authors: Lancelot Boulet, Pierre Benard, Ghislain Lartigue, Vincent Moureau, Nicolas Chauvet, Sheddia Didorally

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International aeronautic standards demand a fire certification for engines that demonstrate their resistance. This demonstration relies on tests performed with prototype engines in the late stages of the development. Hardest tests require to place a kerosene standardized flame in front of the engine casing during a given time with imposed temperature and heat flux. The purpose of this work is to provide a better characterization of a kerosene/air certification burner in order to minimize the risks of test failure. A first Large-Eddy Simulation (LES) study of the certification burner permitted to model and simulate this burner, including both adiabatic and Conjugate Heat Transfer (CHT) computations. Carried out on unstructured grids with 40 million tetrahedral cells, using the finite-volume YALES2 code, spray combustion, forced convection on walls and conduction in the solid parts of the burner were coupled to achieve a detailed description of heat transfer. It highlighted the fact that conduction inside the solid has a real impact on the flame topology and the combustion regime. However, in the absence of radiative heat transfer, unrealistic temperature of the equipment was obtained. The aim of the present study is to include the radiative heat transfer in order to reach the same temperature given by experimental measurements. First, various test-cases are conducted to validate the coupling between the different heat solvers. Then, adiabatic case, CHT case, as well as CHT including radiative transfer are studied and compared. The LES model is finally applied to investigate the heat transfer in a flame impaction configuration. The aim is to progress on fire test modeling so as to reach a good confidence level as far as success of the certification test is concerned.

Keywords: conjugate heat transfer, fire resistance test, large-eddy simulation, radiative transfer, turbulent combustion

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Authors: Fernández-Brito David, Lopez-Medina Javier Alonso, Murillo-Bracamontes Eduardo Antonio, Palomino-Ovando Martha Alicia, Gervacio-Arciniega José Juan

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Magnetic Force Microscopy (MFM) is an Atomic Force Microscopy (AFM) technique that characterizes, at a nanometric scale, the magnetic properties of ferromagnetic materials. Conventional MFM works by scanning in two different AFM modes. The first one is tapping mode, in which the cantilever has short-range force interactions with the sample, with the purpose to obtain the topography. Then, the lift AFM mode starts, raising the cantilever to maintain a fixed distance between the tip and the surface of the sample, only interacting with the magnetic field forces of the sample, which are long-ranged. In recent years, there have been attempts to improve the MFM technique. Bimodal MFM was first theoretically developed and later experimentally proven. In bimodal MFM, the AFM internal piezoelectric is used to cause the cantilever oscillations in two resonance modes simultaneously, the first mode detects the topography, while the second is more sensitive to the magnetic forces between the tip and the sample. However, it has been proven that the cantilever vibrations induced by the internal AFM piezoelectric ceramic are not optimal, affecting the bimodal MFM characterizations. Moreover, the Secondary Resonance Magnetic Force Microscopy (SR-MFM) was developed. In this technique, a coil located below the sample generates an external magnetic field. This alternating magnetic field excites the cantilever at a second frequency to apply the Bimodal MFM mode. Nonetheless, for ferromagnetic materials with a low coercive field, the external field used in SR-MFM technique can modify the magnetic domains of the sample. In this work, a Hybrid Bimodal MFM (HB-MFM) technique is proposed. In HB-MFM, the bimodal MFM is used, but the first resonance frequency of the cantilever is induced by the magnetic field of the ferromagnetic sample due to its vibrations caused by a piezoelectric element placed under the sample. The advantages of this new technique are demonstrated through the preliminary results obtained by HB-MFM on a hard disk sample. Additionally, traditional two pass MFM and HB-MFM measurements were compared.

Keywords: magnetic force microscopy, atomic force microscopy, magnetism, bimodal MFM

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Authors: Amany Haridy, Ahmed Elseragy, Fahd Omar

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The issue of temperature increase in the urban microclimate has been at the center of attention recently, especially in dense urban areas, such as the City of Alexandria in Egypt, where building surfaces have become the dominant element (more than green areas and streets). Temperatures have been rising during daytime as well as nighttime, however, the research focused on the rise of air temperature at night, a phenomenon known as the urban heat island. This phenomenon has many effects on ecological life, as well as human health. This study provided evidence of the possibility of reducing the urban heat island by using a green building envelope (green wall and green roof) in Alexandria, Egypt. This City has witnessed a boom in growth in its urban fabric and population. A simulation analysis using the Envi-met software to find the ratio of air temperature reduction was performed. The simulation depended on the orientation of the green areas and their density, which was defined through a process of climatic analysis made by the Diva plugin using the Grasshopper software. Results showed that the reduction in air temperature varies from 0.8–2.0 °C, increasing with the increasing density of green areas. Many systems of green wall and green roof can be found in the local market. However, treating an existing building requires a careful choice of system to fit the building construction load and the surrounding nature. Among the systems of choice, there was the ‘geometric system’ of vertical greening that can be fixed on a light aluminum structure for walls and the extensive green system for roofs. Finally, native plants were the best choice in the long term because they fare well in the local climate.

Keywords: envi-met, green building envelope, urban heat island, urban microclimate

Procedia PDF Downloads 205

Authors: Mao Zhaofang, Xu Yida, Fang Kan, Fu Enyuan, Zhao Zhao

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Nowadays, last-mile distribution plays an increasingly important role in the whole industrial chain delivery link and accounts for a large proportion of the whole distribution process cost. Promoting the upgrading of logistics networks and improving the layout of final distribution points has become one of the trends in the development of modern logistics. Due to the discrete and heterogeneous needs and spatial distribution of customer demand, which will lead to a higher delivery failure rate and lower vehicle utilization, last-mile delivery has become a time-consuming and uncertain process. As a result, courier companies have introduced a range of innovative parcel storage facilities, including pick-up points and lockers. The introduction of pick-up points and lockers has not only improved the users’ experience but has also helped logistics and courier companies achieve large-scale economy. Against the backdrop of the COVID-19 of the previous period, contactless delivery has become a new hotspot, which has also created new opportunities for the development of collection services. Therefore, a key issue for logistics companies is how to design/redesign their last-mile distribution network systems to create integrated logistics and distribution networks that consider pick-up points and lockers. This paper focuses on the introduction of self-pickup facilities in new logistics and distribution scenarios and the heterogeneous demands of customers. In this paper, we consider two types of demand, including ordinary products and refrigerated products, as well as corresponding transportation vehicles. We consider the constraints associated with self-pickup points and lockers and then address the location-routing problem with self-pickup facilities and heterogeneous demands (LRP-PFHD). To solve this challenging problem, we propose a mixed integer linear programming (MILP) model that aims to minimize the total cost, which includes the facility opening cost, the variable transport cost, and the fixed transport cost. Due to the NP-hardness of the problem, we propose a hybrid adaptive large-neighbourhood search algorithm to solve LRP-PFHD. We evaluate the effectiveness and efficiency of the proposed algorithm by using instances generated based on benchmark instances. The results demonstrate that the hybrid adaptive large neighbourhood search algorithm is more efficient than MILP solvers such as Gurobi for LRP-PFHD, especially for large-scale instances. In addition, we made a comprehensive analysis of some important parameters (e.g., facility opening cost and transportation cost) to explore their impacts on the results and suggested helpful managerial insights for courier companies.

Keywords: city logistics, last-mile delivery, location-routing, adaptive large neighborhood search

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Authors: N. Hachemi, I. Benmehdi, O. Hasnaoui

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The air like water is an essential element for living beings. Each day, a man breathes about 20m3 of air. It originally consists of a set of gas whose presence and concentrations correspond to the needs of life. This study focuses on air pollution by smoke and dust emitted from the chimney of the cement works of Beni Saf, pathological and their impact on the environment. Dust of the cement plant are harmless to permissible levels for living organisms, but the two combined phenomena namely the release of dust and aridity of the climate, which severely marked area of Beni Saf; have contributed adverse effects in on human health and the degradation of vegetation cover and species especially weakened by environmental stress. The most visible impact is certainly the deposition of dust on the surrounding areas of the cement factory, and seriously affecting the aesthetics of the landscape. Health problems are more important inside and outside the factory. Among the diseases notable caused by the cement works are: deafness, heart disease, asthma and mental. The dust of the cement works is mainly composed of fine particles of limestone, clay, free lime, silicates and also loaded of the gases such as carbon dioxide gas CO2. The accumulation of this gas in the atmosphere is directly involved in the phenomenon of increasing of greenhouse effect. Some gases, for example, are directly toxic. They can change the climate, changing precipitation types and become a greater source of stress by drought, etc. The environment also suffers from air pollution indirectly; it is more precisely the acid rain. They are produced by the combustion of non-metals in air. Acid rain has consequences for contaminating the soil, weakening the flora, fauna and acidifies lakes. Finally, the pollution problems are multiple and specific dust. It can worsen and change, it has reached epidemic proportions quantitatively and qualitatively disturbing and unpredictable.

Keywords: atmospheric pollution, cement, dust, environment

Procedia PDF Downloads 335

Authors: Sherine S. Aly, Fahd A. Hemeida, Mohamed A. Elshamy

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In the face of rapid urbanization and the myriad challenges posed by climate change, population growth, and socio-economic disparities, fostering urban resilience has become paramount. This abstract offers a comprehensive overview of the study on "Urban Resilience Challenges," exploring the background, methodologies, major findings, and concluding insights. The paper unveils a spectrum of challenges encompassing environmental stressors and deep-seated socio-economic issues, such as unequal access to resources and opportunities. Emphasizing their interconnected nature, the study underscores the imperative for holistic and integrated approaches to urban resilience, recognizing the intricate web of factors shaping the urban landscape. Urbanization has witnessed an unprecedented surge, transforming cities into dynamic and complex entities. With this growth, however, comes an array of challenges that threaten the sustainability and resilience of urban environments. This study seeks to unravel the multifaceted urban resilience challenges, exploring their origins and implications for contemporary cities. Cities serve as hubs of economic, social, and cultural activities, attracting diverse populations seeking opportunities and a higher quality of life. However, the urban fabric is increasingly strained by climate-related events, infrastructure vulnerabilities, and social inequalities. Understanding the nuances of these challenges is crucial for developing strategies that enhance urban resilience and ensure the longevity of cities as vibrant and adaptive entities. This paper endeavors to discern strategic guidelines for enhancing urban resilience amidst the dynamic challenges posed by rapid urbanization. The study aims to distill actionable insights that can inform strategic approaches. Guiding the formulation of effective strategies to fortify cities against multifaceted pressures. The study employs a multifaceted approach to dissect urban resilience challenges. A qualitative method will be employed, including comprehensive literature reviews and data analysis of urban vulnerabilities that provided valuable insights into the lived experiences of resilience challenges in diverse urban settings. In conclusion, this study underscores the urgency of addressing urban resilience challenges to ensure the sustained vitality of cities worldwide. The interconnected nature of these challenges necessitates a paradigm shift in urban planning and governance. By adopting holistic strategies that integrate environmental, social, and economic considerations, cities can navigate the complexities of the 21st century. The findings provide a roadmap for policymakers, planners, and communities to collaboratively forge resilient urban futures that withstand the challenges of an ever-evolving urban landscape.

Keywords: resilient principles, risk management, sustainable cities, urban resilience

Procedia PDF Downloads 53