Smart Contracts in the Construction Industry: A Systematic Review

On-time delivery of documentation and contracts has been recognized as a crucial requirement for the successful delivery of projects. However, the construction industry still depends on time-consuming traditional contract processes, which negatively affect the overall productivity of projects in the industry. The use of Smart Contracts (SCs) is highlighted as a suitable novel technology to expedite the contract processes and establish a reliable payment environment in the construction industry. Whilst there has been an increase in the debate about the use of SCs in construction in recent years, their use in practice still seems to be in its infancy. As such, the topic will benefit from a thorough review of benefits, drivers, barriers and strategies that can enhance the implementation of SCs in construction. This article presents the key findings from a Systematic Literature Review (SLR) on SCs in the construction industry, critically assessing existing studies on the topic. The study initially involved 171 research papers for the SLR process, and out of that 49 research papers were filtered for further analysis after reading their abstracts. A total of 30 papers were finally filtered after the full-text reading for the SLR. Descriptive and content analysis were used to analyse the full-text findings. The study graphically mapped the bibliographic materials by using the Visualization of Similarities (VoS) Viewer software. As per the findings, the topic has mostly been researched in Asia and the Pacific as a region and China as a country. It was noted that there were more empirical articles than theoretical studies related to SCs, evidencing the industry relevance of the issue. A total of 55% of the articles reviewed have been published in journals with a Q1 ranking. All the articles were written by multiple authors, with 30% of the journal articles having international co-authors and benefitting from the collaboration between authors. Key advantages identified in the literature go beyond contract and payment provisions and include aspects such as logistic handling, decentralized applications, business process management, automated payments, etc. Key drivers for adoption are supply chain pressure, competitive pressure, top management support, simple layout, reduction in risks of clients, clarity in responsibility and risk allocation, whereas the key barriers include insecurity, limited observability, incompatibility, inactive government collaboration and limited storage capacity. Key strategies to enhance the application of SC in construction include integrating theorems proving symbolic execution, using the selective transparency method and lock fund system, testing the integration of SCs with other systems at the initial stage, incorporating semi-automated consensus mechanisms for payments, constructing a mechanism to actively engage with government bodies, et

REST-based Offline e-Mail System

Over the years the Internet has grown from a research tool to a worldwide communication medium. One of the applications that has grown up with the Internet is e-mail. e-Mail has become an indispensable tool for both corporations and individuals, and web-based e-mail systems have become very popular. However, a major problem with web-based email is we cannot access them when not connected to the Internet. We have built an off-line web-based e-mail system to overcome this issue, and to provide fast response even over slow connections. This system is based on Representational State Transfer (REST) and maintains HTML5 local storage to store mail and meta-data in the browser without installing any plug-ins. The system records all user actions locally and synchronizes with the server when connected to the Internet

Embodied Energy Consumption in the Residential Sector: A Case Study of Affordable Housing

Embodied energy has a significant effect on the total environmental impact of a project. However, emphasis is often placed primarily on operational energy, resulting in a knowledge gap about the current state of embodied energy use in affordable housing. To address this, the study investigates the level of embodied energy consumption in affordable housing, as well as the drivers, barriers, and techniques to reduce embodied energy. Based on a single embedded case study covering the period from cradle to end of construction, data were collected using embodied energy calculations of three affordable housing units in the project, semi-structured interviews with five design team members, and a cross-examination of findings with contract documents. The results were analysed using sensitivity analysis and thematic analysis. The findings revealed that all three house units fulfilled the baseline embodied carbon target of 800 kg CO2/m2 and both detached properties fell within the LETI (2020) target of 500 kg CO2/m2. However, all three properties would fail to meet the RIBA or 2030 LETI target of 300 kg CO2/m2. This suggests that improvements are necessary to achieve future targets. The results show that financial capabilities and operational energy prioritisation act as the main enabler and barrier for reducing embodied energy. Local contractors/suppliers, minimising material use or intensity, and modular construction were highlighted as the key reduction techniques that can be used to help achieve future targets concerning embodied carbon in residential developments. The study contributes significantly to understanding the current state of embodied energy use in affordable housing and provides new insights on how to deal with embodied energy if we are to meet future energy targets

An Assessment of Intra-household Allocation of Food: A Case Study of the Urban Poor in Kandy

Malnutrition among children and women continues to be one of the major problems in Sri Lanka despite the food and nutritional intervention programs implemented since independence. The objectives of this study were to find out whether there is calorie malnutrition among the urban poor in Kandy and to find out the determinants of the intra-household allocation of calories. Calorie adequacy ratios of fathers, mothers and children were compared to find out whether there is calorie malnutrition among family members. Relative calorie allocation of individuals was regressed with socio-economic variables to find the determinants of the intra-household calorie allocation. Primary data collected using a structured questionnaire from sixty households in the lower income group in urban Kandy was used for the analysis. Results show that there was a significant difference among calorie adequacy ratios of fathers, mothers and children. Fathers have the highest and children have the lowest mean calorie adequacy ratios. Regression results indicate that income of mother and family size have significant positive and negative impacts respectively on mother’s relative calorie allocation. Results also show that there was an age and gender biased calorie allocation within the family. Income of mother had a negative effect on children’s calorie allocation. Though expansion in employment opportunities could alleviate malnutrition among women, it may aggravate malnutrition among children

REST-based Offline e-Mail System

Over the years the Internet has grown from a research tool to a worldwide communication medium. One of the applications that has grown up with the Internet is e-mail. e-Mail has become an indispensable tool for both corporations and individuals, and web-based e-mail systems have become very popular. However, a major problem with web-based email is we cannot access them when not connected to the Internet. We have built an off-line web-based e-mail system to overcome this issue, and to provide fast response even over slow connections. This system is based on Representational State Transfer (REST) and maintains HTML5 local storage to store mail and meta-data in the browser without installing any plug-ins. The system records all user actions locally and synchronizes with the server when connected to the Internet

Chemical Composition and Antimicrobial Activity of Two Sri Lankan Lichens, Parmotrema rampoddense, and Parmotrema tinctorum against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus

Introduction. Medicinal utility of lichens is ascribed to the presence of various secondary metabolites of low molecular weight and they have been used in traditional medicine including Ayurveda in the treatment of wounds and skin disorders. Despite the urgent need to effectively address the antibiotic resistance worldwide, the discovery of new antibacterial drugs has declined in the recent past. This emphasizes the increasing importance of investigating and developing new classes of antibiotics that can withstand antibiotic resistance. Aims of the study. The present study was conducted to investigate the chemical composition and the antibacterial activity of hexane, ethanol, and aqueous extracts of Parmotrema rampoddense and Parmotrema tinctorum, two lichens collected from Belihuloya, Sri Lanka, against Gram-negative and Gram-positive bacteria including twenty clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Materials and methods. Phytochemical analysis, thin layer chromatography (TLC), and Gas Chromatography Mass Spectrometry (GC-MS) were performed to determine the chemical composition of the two lichens. Hexane, ethanol, and aqueous extracts of both lichens were tested against clinical isolate of Gram-negative and Gram-positive bacteria including twenty clinical isolates of MRSA. Bacterial susceptibility was tested using a disc diffusion assay. Minimum inhibitory concentration (MIC) was determined by a broth microdilution method. Vancomycin was used as the positive control. Results. Alectorialic acid, atranorin, atraric acid, orcinol, and O-orsellinaldehyde were among the secondary metabolites identified by the TLC and GC-MS analysis. None of the lichen extracts were active against Gram-negative bacteria but both lichens showed a concentration-dependent activity against methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA. Ethanol extract of P. rampoddense showed the highest activity against MSSA with the MIC, 0.0192 mg/ml, but all MRSA isolates investigated showed MIC between 0.096 and 2.4 mg/ml for the same extract. Conclusion. Both lichens, P. rampoddense and P. tinctorum, represent potentially important sources of future antimicrobial drugs. Further investigation on the ethanol extract of P. rampoddense will enable us to determine the most active phytoconstituents responsible for the activity, their mechanism of action against bacterial pathogens, and also their cytotoxicity against normal cells

Physics with Positron Beams at Jefferson Lab 12 GeV

Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental program at the next generation of lepton accelerators. In the context of the Hadronic Physics program at the Jefferson Laboratory (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of the nucleon, in both the elastic and the deep-inelastic regimes. For instance, elastic scattering of (un)polarized electrons and positrons off the nucleon allows for a model independent determination of the electromagnetic form factors of the nucleon. Also, the deeply virtual Compton scattering of (un)polarized electrons and positrons allows us to separate unambiguously the different contributions to the cross section of the lepto-production of photons, enabling an accurate determination of the nucleon Generalized Parton Distributions (GPDs), and providing an access to its Gravitational Form Factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model through the search of a dark photon or the precise measurement of electroweak couplings. This letter proposes to develop an experimental positron program at JLab to perform unique high impact measurements with respect to the two-photon exchange problem, the determination of the proton and the neutron GPDs, and the search for the $A^{\prime}$ dark photon