The paper investigated the compressive strength of ground granulated blast furnace slag-based geopolymer concrete incorporated with palm oil fuel ash compared to portland limestone cement concrete. An appropriate geopolymer mix design was first determined. This mix entailed fine aggregates: coarse aggregates: cementitious material: liquid ratio of 2: 2.5: 1: 0.5, respectively, with 100% replacement of portland cement with ground granulated blast furnace slag (GGBS) incorporated with palm oil fuel ash (POFA). An alkaline solution was used in place of water containing sodium hydroxide and sodium silicate. Following this design, five geopolymer mixes were prepared, each of varying POFA-GGBS ratios of 0:100, 25:75, 50:50, 75:25, and 100:0, and a 14M alkaline solution was used. In addition, a control mix was determined, comprising 100% portland limestone cement (PLC) as the cementitious material and 100% water. Three cubic samples were casted for each geopolymer mix with the control mix, and then the geopolymer mixes were thermally cured for 24 hours. The compressive strength test was conducted on the test samples after ambient curing of 7 days and 28 days, and values for compressive strength (MPa) and failure load (KN) were recorded. Through comparative analysis, it was determined that the most efficient geopolymer mix was mix 2 of GGBS: POFA ratio of 75:25 with 14M alkaline solution. Mix 2 achieved the highest compressive strength of 65.41MPa, approximately 21.99% higher than the strength attained by portland cement concrete samples, measured to be 53.62MPa. Thus, geopolymer concrete can achieve greater strength than portland cement concrete. Keywords: Alkaline solution, Geopolymer concrete, cementitious material, ground granulated blast furnace slag, compressive strength, palm oil fuel ash
{"title":"Investigation of Compressive Strength of Slag-based Geopolymer Concrete Incorporated with Palm Oil Fuel Ash","authors":"F. Olutoge, Anuoluwapo Sola Kolade","doi":"10.47412/zgij9698","DOIUrl":"https://doi.org/10.47412/zgij9698","url":null,"abstract":"The paper investigated the compressive strength of ground granulated blast furnace slag-based geopolymer concrete incorporated with palm oil fuel ash compared to portland limestone cement concrete. An appropriate geopolymer mix design was first determined. This mix entailed fine aggregates: coarse aggregates: cementitious material: liquid ratio of 2: 2.5: 1: 0.5, respectively, with 100% replacement of portland cement with ground granulated blast furnace slag (GGBS) incorporated with palm oil fuel ash (POFA). An alkaline solution was used in place of water containing sodium hydroxide and sodium silicate. Following this design, five geopolymer mixes were prepared, each of varying POFA-GGBS ratios of 0:100, 25:75, 50:50, 75:25, and 100:0, and a 14M alkaline solution was used. In addition, a control mix was determined, comprising 100% portland limestone cement (PLC) as the cementitious material and 100% water. Three cubic samples were casted for each geopolymer mix with the control mix, and then the geopolymer mixes were thermally cured for 24 hours. The compressive strength test was conducted on the test samples after ambient curing of 7 days and 28 days, and values for compressive strength (MPa) and failure load (KN) were recorded. Through comparative analysis, it was determined that the most efficient geopolymer mix was mix 2 of GGBS: POFA ratio of 75:25 with 14M alkaline solution. Mix 2 achieved the highest compressive strength of 65.41MPa, approximately 21.99% higher than the strength attained by portland cement concrete samples, measured to be 53.62MPa. Thus, geopolymer concrete can achieve greater strength than portland cement concrete. Keywords: Alkaline solution, Geopolymer concrete, cementitious material, ground granulated blast furnace slag, compressive strength, palm oil fuel ash","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114873448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is a continuation of a history of the Department of Civil Engineering at The University of the West Indies (UWI) at St. Augustine. It thus extends an account of its formative decade 1961-1971 previously published (in 2013) in The West Indian Journal of Engineering. The three subsequent decades covered herein encompass milestones, and transformations: (a) beginning of graduate level research, (b) commencement of an MSc programme in Construction Engineering and Management, (c) change of name from Civil to ‘Civil and Environmental’ for embracing the heightened awareness of environmental concerns, (d) relocation into a purpose-built building with a floor space of approximately 5,000 m2, (e) construction of new environmental engineering, engineering geology, highway engineering, soil mechanics and structural engineering laboratories, (f) expansion and modernisation of the fluid mechanics laboratory, and (g) introduction of the semester system with its credit-based curriculum and assessment. Besides, there was a fivefold increase in student enrolment, followed by a sharp decline, and an increase in academic staff strength from six to twenty. This period also witnessed a gradual loss of regional diversity of its undergraduate students from a high of approximately 50 % in 1972 to less than 10% in 2001. On the other hand, there was a notable, and opposite, change in gender (female/male) ratio among the students – from less than 10%/90% in 1972 to approximately 50%/50% in 2001. Finally, the accreditation of the department’s degree programmes by the Engineering Council in the United Kingdom (UK), as well as the triennial visit of overseas external examiners, inherited from its inception, were maintained. Keywords: Civil Engineering; Coastal Engineering; Environmental Engineering; Education; History; University; West Indies
{"title":"The Department of Civil Engineering, UWI St. Augustine: A Historical Note of 1972-2001","authors":"G. Shrivastava","doi":"10.47412/uysc7563","DOIUrl":"https://doi.org/10.47412/uysc7563","url":null,"abstract":"This paper is a continuation of a history of the Department of Civil Engineering at The University of the West Indies (UWI) at St. Augustine. It thus extends an account of its formative decade 1961-1971 previously published (in 2013) in The West Indian Journal of Engineering. The three subsequent decades covered herein encompass milestones, and transformations: (a) beginning of graduate level research, (b) commencement of an MSc programme in Construction Engineering and Management, (c) change of name from Civil to ‘Civil and Environmental’ for embracing the heightened awareness of environmental concerns, (d) relocation into a purpose-built building with a floor space of approximately 5,000 m2, (e) construction of new environmental engineering, engineering geology, highway engineering, soil mechanics and structural engineering laboratories, (f) expansion and modernisation of the fluid mechanics laboratory, and (g) introduction of the semester system with its credit-based curriculum and assessment. Besides, there was a fivefold increase in student enrolment, followed by a sharp decline, and an increase in academic staff strength from six to twenty. This period also witnessed a gradual loss of regional diversity of its undergraduate students from a high of approximately 50 % in 1972 to less than 10% in 2001. On the other hand, there was a notable, and opposite, change in gender (female/male) ratio among the students – from less than 10%/90% in 1972 to approximately 50%/50% in 2001. Finally, the accreditation of the department’s degree programmes by the Engineering Council in the United Kingdom (UK), as well as the triennial visit of overseas external examiners, inherited from its inception, were maintained. Keywords: Civil Engineering; Coastal Engineering; Environmental Engineering; Education; History; University; West Indies","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134509777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amir Mohammed, F. Muddeen, Lincoln Marine, C. Ramlal
Critical Infrastructures (CIs) are essential assets used to maintain vital societal functions, for example utilities such as power, water, gas, and telecommunication networks. CIs comprise two main parts, namely a: Cyber component and a Physical component, which allow them to operate. Therefore, the occurrence of faults or attacks in either domain can result in the disruption of services, causing negative impacts beyond the system itself. The purpose of this article is to raise awareness within Trinidad and Tobago and, by extension, the Caribbean on the importance of maintaining resilient and cyber secure CIs for the purpose of critical infrastructure protection (CIP) given the current situation. A review of past incidents from 2012 - 2022 taken place both regionally and internationally is discussed, with major emphasis on those occurring in the Caribbean region. These incidents have been presented from the perspective of faults and cyber-attacks affecting CIs resulting in the disruption of services. In responding to frequently occurring scenarios, recommendations on the way forward have been proposed. Keywords: Critical Infrastructures (CIs), Critical Infrastructure Protection (CIP), Resilient Control, Cyber-attacks, Fault Tolerant Control
{"title":"The Exigency for Resilient and Cyber-Secure Critical Infrastructure in the Caribbean","authors":"Amir Mohammed, F. Muddeen, Lincoln Marine, C. Ramlal","doi":"10.47412/deox2766","DOIUrl":"https://doi.org/10.47412/deox2766","url":null,"abstract":"Critical Infrastructures (CIs) are essential assets used to maintain vital societal functions, for example utilities such as power, water, gas, and telecommunication networks. CIs comprise two main parts, namely a: Cyber component and a Physical component, which allow them to operate. Therefore, the occurrence of faults or attacks in either domain can result in the disruption of services, causing negative impacts beyond the system itself. The purpose of this article is to raise awareness within Trinidad and Tobago and, by extension, the Caribbean on the importance of maintaining resilient and cyber secure CIs for the purpose of critical infrastructure protection (CIP) given the current situation. A review of past incidents from 2012 - 2022 taken place both regionally and internationally is discussed, with major emphasis on those occurring in the Caribbean region. These incidents have been presented from the perspective of faults and cyber-attacks affecting CIs resulting in the disruption of services. In responding to frequently occurring scenarios, recommendations on the way forward have been proposed. Keywords: Critical Infrastructures (CIs), Critical Infrastructure Protection (CIP), Resilient Control, Cyber-attacks, Fault Tolerant Control","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123531628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, an alcoholic fermented beverage of acceptable quality characteristics was produced from two types of dasheen (Colocasia esculenta L. Schott) musts, A – boiled dasheen must and B – cooked dasheen with must, each at three total soluble solids (TSS) levels (18, 22 and 25 °Brix). Quality characteristics of pH, TSS, alcohol content, titratable acidity (TA), specific gravity (SG), and spectrophotometric, microbiological, and sensory evaluations were analysed in the fermented beverages. Fermentation caused pH, SG and TSS to decrease while simultaneously increased TA. Coliforms were not detected in any of the must and fermented beverage samples. The one-way ANOVA showed a significant difference (p<0.05) when the fermented beverage from musts A and B was compared on the final quality parameters of pH, SG, TSS, TA, a* component and sensory attributes (appearance, colour, taste, and mouthfeel). The beverage made from batch A, 25 °Brix was consumer acceptable based on sensory and physicochemical analyses with a pH of 3.12, SG of 1.0053, TSS of 10.13 °Brix, TA (% citric acid) of 0.75% and an alcohol content of 14.00 and 12.52% using the hydrometer and gas chromatography methods respectively. For the spectrophotometric analysis, the absorbance at 420 nm wavelength was 0.246 while the L* a* b* colour indices were 88.59, 0.13, and 1.36 respectively. The overall results indicate that this product can be beneficial to the Caribbean food and beverage industries. Keywords: Dasheen (Colocasia esculenta), alcoholic fermentation, sensory attributes, colorimetry, spectrophotometry, gas chromatography-flame ionisation detector
在这项研究中，用两种类型的茴香(Colocasia esculenta L. Schott)茴香，A -煮茴香和B -煮茴香，每一种都有三种总可溶性固形物(TSS)水平(18、22和25°白利度)，生产出一种质量特征可接受的酒精发酵饮料。分析了发酵饮料的pH、TSS、酒精含量、可滴定酸度(TA)、比重(SG)以及分光光度、微生物学和感官评价的质量特征。发酵使pH、SG和TSS降低，同时使TA升高。所有发酵饮料样品均未检出大肠菌群。单因素方差分析显示，a、B两种发酵液的最终质量参数pH、SG、TSS、TA、a*组分和感官属性(外观、颜色、味道、口感)均有显著差异(p<0.05)。通过感官和物理化学分析，消费者可以接受A批次25°白利度的饮料，pH为3.12,SG为1.0053,TSS为10.13°白利度，TA(%柠檬酸)为0.75%，使用比比计和气相色谱法分别为14.00和12.52%。在420 nm处吸光度为0.246,L* a* b*显色指数分别为88.59、0.13和1.36。总体结果表明，该产品可有利于加勒比地区的食品和饮料工业。关键词:大黄，酒精发酵，感官属性，比色法，分光光度法，气相色谱-火焰电离检测器
{"title":"Production and Characterisation of a Novel Dasheen (Colocasia esculenta) Alcoholic Fermented Beverage","authors":"Kerrian Jackson, R. Maharaj, M. Dookeran","doi":"10.47412/ufbj4076","DOIUrl":"https://doi.org/10.47412/ufbj4076","url":null,"abstract":"In this study, an alcoholic fermented beverage of acceptable quality characteristics was produced from two types of dasheen (Colocasia esculenta L. Schott) musts, A – boiled dasheen must and B – cooked dasheen with must, each at three total soluble solids (TSS) levels (18, 22 and 25 °Brix). Quality characteristics of pH, TSS, alcohol content, titratable acidity (TA), specific gravity (SG), and spectrophotometric, microbiological, and sensory evaluations were analysed in the fermented beverages. Fermentation caused pH, SG and TSS to decrease while simultaneously increased TA. Coliforms were not detected in any of the must and fermented beverage samples. The one-way ANOVA showed a significant difference (p<0.05) when the fermented beverage from musts A and B was compared on the final quality parameters of pH, SG, TSS, TA, a* component and sensory attributes (appearance, colour, taste, and mouthfeel). The beverage made from batch A, 25 °Brix was consumer acceptable based on sensory and physicochemical analyses with a pH of 3.12, SG of 1.0053, TSS of 10.13 °Brix, TA (% citric acid) of 0.75% and an alcohol content of 14.00 and 12.52% using the hydrometer and gas chromatography methods respectively. For the spectrophotometric analysis, the absorbance at 420 nm wavelength was 0.246 while the L* a* b* colour indices were 88.59, 0.13, and 1.36 respectively. The overall results indicate that this product can be beneficial to the Caribbean food and beverage industries. Keywords: Dasheen (Colocasia esculenta), alcoholic fermentation, sensory attributes, colorimetry, spectrophotometry, gas chromatography-flame ionisation detector","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129269050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accelerated global population increase, socioeconomic and environmental changes have resulted in spiralling maintenance costs for pavements. Current understanding of pavement deterioration fails to address this longstanding issue, and Small Island Developing States (SIDS) are not immune to the recurring expense incurred from pavement degradation. Existing academic debates on design and construction inadequacies in pavement longevity do not address regular maintenance challenges. This research examines the reasons for frequent pavement failures and explains how they affect Trinidad and Tobago’s future maintenance and economic development. A questionnaire was completed by 120 contractors, consultants, and state agency experts specialising in road construction and maintenance. The findings revealed from an assessment of the Relative Importance Index (RII) that utility cuts by the Water and Sewerage Authority were the most important (0.904), followed by maintenance culture (0.898), quality of work (workmanship) (0.888), poor drainage facilities, and overloaded vehicles (0.854). Climate change (temperature) was the lowest-ranked cause overall (0.568). The findings also show that economic growth and development are directly and indirectly affected, resulting in high vehicle running costs, longer travel times, and higher prices for fundamental products and services. Recommendations are made to aid engineers and policymakers in identifying critical causes and reducing the adverse consequences of frequent pavement failure. Keywords: Maintenance, Pavement deterioration, Perceptions, Road failures, Trinidad and Tobago
{"title":"Dominating Factors of Road Failures: Perceptions of Key Stakeholders in the Small Island Developing State of Trinidad and Tobago","authors":"L. Leon, L. Ellis, H. Martin, Byron Fermin","doi":"10.47412/mgbb4897","DOIUrl":"https://doi.org/10.47412/mgbb4897","url":null,"abstract":"Accelerated global population increase, socioeconomic and environmental changes have resulted in spiralling maintenance costs for pavements. Current understanding of pavement deterioration fails to address this longstanding issue, and Small Island Developing States (SIDS) are not immune to the recurring expense incurred from pavement degradation. Existing academic debates on design and construction inadequacies in pavement longevity do not address regular maintenance challenges. This research examines the reasons for frequent pavement failures and explains how they affect Trinidad and Tobago’s future maintenance and economic development. A questionnaire was completed by 120 contractors, consultants, and state agency experts specialising in road construction and maintenance. The findings revealed from an assessment of the Relative Importance Index (RII) that utility cuts by the Water and Sewerage Authority were the most important (0.904), followed by maintenance culture (0.898), quality of work (workmanship) (0.888), poor drainage facilities, and overloaded vehicles (0.854). Climate change (temperature) was the lowest-ranked cause overall (0.568). The findings also show that economic growth and development are directly and indirectly affected, resulting in high vehicle running costs, longer travel times, and higher prices for fundamental products and services. Recommendations are made to aid engineers and policymakers in identifying critical causes and reducing the adverse consequences of frequent pavement failure. Keywords: Maintenance, Pavement deterioration, Perceptions, Road failures, Trinidad and Tobago","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128546939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The World Bank in a decade ago reported a global collective of 1.3 billion tons of solid waste every year with building material accounting for half of this volume annually worldwide. Recycled materials from demolition sites have increased over the years to curtail the demand for natural aggregates (NA). This study investigates the use of recycled concrete aggregates (RCA) produced from high strength concrete and its effects on the mechanical properties of concrete and structural members. Further comparison was made to concrete with steel fibers. The results showed that the compressive strength of RCA concrete was 5% greater than NA concrete. The influence of the properties of durability and crushing resistance of the RCA, which exceeded that of NA, contributed to the higher concrete strengths when compared to NA concrete. Additionally, concrete with RCA and steel fibers had an increase of compressive strength by 16% to concrete without steel fibers. However, no significant increase in the deflection and strain of the beams under third point loading suggest that given the right conditions RCA can be used in place of NA Keywords: Construction waste; engineering sustainability; recycled concrete aggregate; structural members; steel fiber; waste management.
{"title":"Investigating the Use of Recycled Concrete as Aggregates in the Construction of Structural Beams","authors":"L. Ellis, L. Leon, Amy V. Charran","doi":"10.47412/xrhg1947","DOIUrl":"https://doi.org/10.47412/xrhg1947","url":null,"abstract":"The World Bank in a decade ago reported a global collective of 1.3 billion tons of solid waste every year with building material accounting for half of this volume annually worldwide. Recycled materials from demolition sites have increased over the years to curtail the demand for natural aggregates (NA). This study investigates the use of recycled concrete aggregates (RCA) produced from high strength concrete and its effects on the mechanical properties of concrete and structural members. Further comparison was made to concrete with steel fibers. The results showed that the compressive strength of RCA concrete was 5% greater than NA concrete. The influence of the properties of durability and crushing resistance of the RCA, which exceeded that of NA, contributed to the higher concrete strengths when compared to NA concrete. Additionally, concrete with RCA and steel fibers had an increase of compressive strength by 16% to concrete without steel fibers. However, no significant increase in the deflection and strain of the beams under third point loading suggest that given the right conditions RCA can be used in place of NA Keywords: Construction waste; engineering sustainability; recycled concrete aggregate; structural members; steel fiber; waste management.","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125656966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Port of Spain (POS) functions as the administrative, political, and commercial capital of Trinidad and Tobago, attracting many commuters daily. This paper reports the first part of a two-stage process of developing a quantitative measure of the performance of the Port of Spain public transportation network. It provides insight into the key stakeholders and the needs, preferences, and satisfaction of users of the Port of Spain transportation network. The key stakeholders in the transportation network were identified and classified in a stakeholder matrix on the basis of their interest and influence. A survey was undertaken to understand the public’s perception of the transport network and the travel patterns and characteristics. The results suggest that while most trips to and within Port of Spain are completed for employment, a significant percentage is for personal business and shopping/leisure. Moreover, while the largest number of trips ended in the central business district (CBD) of Port of Spain’s most destinations are outside the CBD. Survey participants were broadly dissatisfied with the transport system, indicating strong dissatisfaction with congestion, lack of accessibility and lack of information experienced in the capital city. Indeed, a minimum of forty-four percent and a maximum of seventy-eight of respondents were either dissatisfied or very dissatisfied with some aspects of the transport system. No more than twenty-five percent, and in the case of congestion only three percent, of respondents were either satisfied or very satisfied. Although transport safety received the least negative response among the transport indicators, approximately forty-six percent of respondents were dissatisfied or very dissatisfied with it. In general, females reported more dissatisfaction with transport safety compared to men. The findings also highlighted how disadvantaged users of public transportation are with respect to ease of travel to and within the city. This paper reports on the mapping of the network and the development of a performance index. Keywords: Commuter surveys, Stakeholder engagement, Traveller perceptions, Port of Spain; Trinidad and Tobago
{"title":"Port of Spain Commuter Patterns and Satisfaction Levels","authors":"Mildred Boneo, T. Townsend","doi":"10.47412/hovr8360","DOIUrl":"https://doi.org/10.47412/hovr8360","url":null,"abstract":"Port of Spain (POS) functions as the administrative, political, and commercial capital of Trinidad and Tobago, attracting many commuters daily. This paper reports the first part of a two-stage process of developing a quantitative measure of the performance of the Port of Spain public transportation network. It provides insight into the key stakeholders and the needs, preferences, and satisfaction of users of the Port of Spain transportation network. The key stakeholders in the transportation network were identified and classified in a stakeholder matrix on the basis of their interest and influence. A survey was undertaken to understand the public’s perception of the transport network and the travel patterns and characteristics. The results suggest that while most trips to and within Port of Spain are completed for employment, a significant percentage is for personal business and shopping/leisure. Moreover, while the largest number of trips ended in the central business district (CBD) of Port of Spain’s most destinations are outside the CBD. Survey participants were broadly dissatisfied with the transport system, indicating strong dissatisfaction with congestion, lack of accessibility and lack of information experienced in the capital city. Indeed, a minimum of forty-four percent and a maximum of seventy-eight of respondents were either dissatisfied or very dissatisfied with some aspects of the transport system. No more than twenty-five percent, and in the case of congestion only three percent, of respondents were either satisfied or very satisfied. Although transport safety received the least negative response among the transport indicators, approximately forty-six percent of respondents were dissatisfied or very dissatisfied with it. In general, females reported more dissatisfaction with transport safety compared to men. The findings also highlighted how disadvantaged users of public transportation are with respect to ease of travel to and within the city. This paper reports on the mapping of the network and the development of a performance index. Keywords: Commuter surveys, Stakeholder engagement, Traveller perceptions, Port of Spain; Trinidad and Tobago","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115374088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The demands on future energy conversion technologies are becoming increasingly stringent. Biofuels, which are considered to have a critical role in meeting growing energy needs, must find increasing avenues for compliance. Accordingly, ternary fuel blends have received significant attention because their physiochemical properties can be very similar to diesel, while overcoming some challenges associated with traditional biofuel use. Consequently, this work assesses the use of alcohol-biodiesel-vegetable oil blends in Compression Ignition (CI) engines. Three ethanol-biodiesel-vegetable oil blends were developed using 10%, 20% and 30% alcohol and their performances were compared to diesel and neat coconut oil. These blends were tested in a single cylinder diesel engine and their performances assessed using energy, emissions and exergy analyses. The results indicated that the blends had better brake thermal efficiency (BTE) values than diesel at high to medium loads, with the E30 blend having the highest BTE value of 31% at full load conditions as compared to 28.9% for diesel. The blends were also found to be comparable to diesel based on a First Law energy analysis. Additionally, it was found that the blends had better nitric oxides (NO) emission levels than diesel; at full load conditions, the E30 blend had the lowest value of 281 ppm as compared to diesel having a value of 299 ppm. However, they were found to have comparable levels for the other emissions characteristics that were examined. Further, the Second Law analyses indicated that the blends made better use of their fuel energy potential and thus, can be considered as a more suitable fuel for CI engine combustion. Collectively, the results suggest that the ternary blends are a viable candidate for future energy conversion via CI engines. Keywords: Ternary blends; ethanol; coconut oil; CI engines; exergy analysis; alternative fuels
{"title":"Energy, Emissions and Exergy Analyses of Ethanol-Biodiesel-Coconut Oil Ternary Fuel Blends and Comparative Assessment of Their Performance in Compression Ignition Engines","authors":"Renique Murray","doi":"10.47412/seca5934","DOIUrl":"https://doi.org/10.47412/seca5934","url":null,"abstract":"The demands on future energy conversion technologies are becoming increasingly stringent. Biofuels, which are considered to have a critical role in meeting growing energy needs, must find increasing avenues for compliance. Accordingly, ternary fuel blends have received significant attention because their physiochemical properties can be very similar to diesel, while overcoming some challenges associated with traditional biofuel use. Consequently, this work assesses the use of alcohol-biodiesel-vegetable oil blends in Compression Ignition (CI) engines. Three ethanol-biodiesel-vegetable oil blends were developed using 10%, 20% and 30% alcohol and their performances were compared to diesel and neat coconut oil. These blends were tested in a single cylinder diesel engine and their performances assessed using energy, emissions and exergy analyses. The results indicated that the blends had better brake thermal efficiency (BTE) values than diesel at high to medium loads, with the E30 blend having the highest BTE value of 31% at full load conditions as compared to 28.9% for diesel. The blends were also found to be comparable to diesel based on a First Law energy analysis. Additionally, it was found that the blends had better nitric oxides (NO) emission levels than diesel; at full load conditions, the E30 blend had the lowest value of 281 ppm as compared to diesel having a value of 299 ppm. However, they were found to have comparable levels for the other emissions characteristics that were examined. Further, the Second Law analyses indicated that the blends made better use of their fuel energy potential and thus, can be considered as a more suitable fuel for CI engine combustion. Collectively, the results suggest that the ternary blends are a viable candidate for future energy conversion via CI engines. Keywords: Ternary blends; ethanol; coconut oil; CI engines; exergy analysis; alternative fuels","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114951181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a finite volume analysis of the aerodynamics and heat transfer in attics of a clerestory roof design with pitch angles 14o, 18o, 30o and 45o and Rayleigh number range 3 x 105≤ Ra ≤ 2 x 107 is carried out. The shape of the enclosure has strong influence on the structure of the flow and temperature fields. The flow field is characterised by counter-rotating vortices enclosed by aerodynamic boundary layers. The size, strength and direction of rotation of the cells are controlled by the forces propelling the thermal plumes and the cold jets. The reduction of the number and size of the counter-rotating cells and their formation within the enclosures provide an analogous reduction of the total heat transfer rate as the roof pitch angle increases. The velocity and temperature profiles across midheight and midlength of the enclosures enable the prediction of appropriate position in the attic with the right condition to place sensitive items. On the heat transfer, the relationship between the mean Nusselt number and the Rayleigh number is presented in form of a correlation. Results obtained in the study are of significance to building engineers engaged in the analysis and design of building attics and tropical agriculturalists for the control of produce drying rates. Keywords: Heat transfer, heated below, natural convection, pitch roof, clerestory-shaped
{"title":"Fluid Flow and Heat Transfer Characteristics of Clerestory-Shaped Attics Heated from Below","authors":"O. Kamiyo, A. Waheed","doi":"10.47412/xiid6834","DOIUrl":"https://doi.org/10.47412/xiid6834","url":null,"abstract":"In this study, a finite volume analysis of the aerodynamics and heat transfer in attics of a clerestory roof design with pitch angles 14o, 18o, 30o and 45o and Rayleigh number range 3 x 105≤ Ra ≤ 2 x 107 is carried out. The shape of the enclosure has strong influence on the structure of the flow and temperature fields. The flow field is characterised by counter-rotating vortices enclosed by aerodynamic boundary layers. The size, strength and direction of rotation of the cells are controlled by the forces propelling the thermal plumes and the cold jets. The reduction of the number and size of the counter-rotating cells and their formation within the enclosures provide an analogous reduction of the total heat transfer rate as the roof pitch angle increases. The velocity and temperature profiles across midheight and midlength of the enclosures enable the prediction of appropriate position in the attic with the right condition to place sensitive items. On the heat transfer, the relationship between the mean Nusselt number and the Rayleigh number is presented in form of a correlation. Results obtained in the study are of significance to building engineers engaged in the analysis and design of building attics and tropical agriculturalists for the control of produce drying rates. Keywords: Heat transfer, heated below, natural convection, pitch roof, clerestory-shaped","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122333719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Literature indicates rapid prototyping (RP) application has become more widespread in design and development of human anatomy models. Practitioners are facing challenges in deployment of RP tools for development of cost-effective medical models, because there are no proven decision support systems in the selection of parameters such as speed, accuracy, materials, and customisation of commercial software. This study aims at alleviating some of these issues by exploring the use of a Genetic Algorithm (GA) approach combined with computer-aided design (CAD) and fused deposition modeling (FDM) techniques. Experiments were conducted using response surface methodology (RSM) to facilitate the optimisation process with build time and model material volume as responses. The validation of the study has been performed with a patella model and the results verified the effectiveness of the proposed RSM-GA approach in the design and development of the anatomical model. The results showed a 27% savings on model material compared to a non-refined model and was deemed satisfactory for practical use as there was a reduction in irregularities from CT data. The study also reveals that the parameter hollow has the largest effect on the responses, followed by the smooth parameter and then the wrap parameter.
{"title":"Mitigation of Design Issues in Development of Anatomical Models Using Rapid Prototyping","authors":"Nishkal George, B. Chowdary","doi":"10.47412/upfp4130","DOIUrl":"https://doi.org/10.47412/upfp4130","url":null,"abstract":"Literature indicates rapid prototyping (RP) application has become more widespread in design and development of human anatomy models. Practitioners are facing challenges in deployment of RP tools for development of cost-effective medical models, because there are no proven decision support systems in the selection of parameters such as speed, accuracy, materials, and customisation of commercial software. This study aims at alleviating some of these issues by exploring the use of a Genetic Algorithm (GA) approach combined with computer-aided design (CAD) and fused deposition modeling (FDM) techniques. Experiments were conducted using response surface methodology (RSM) to facilitate the optimisation process with build time and model material volume as responses. The validation of the study has been performed with a patella model and the results verified the effectiveness of the proposed RSM-GA approach in the design and development of the anatomical model. The results showed a 27% savings on model material compared to a non-refined model and was deemed satisfactory for practical use as there was a reduction in irregularities from CT data. The study also reveals that the parameter hollow has the largest effect on the responses, followed by the smooth parameter and then the wrap parameter.","PeriodicalId":364752,"journal":{"name":"West Indian Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116943282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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