Contractual obligations analysis for construction waste management in Canada

Construction industry creates a massive amount of waste, which typically ends up in landfills. Canadian construction industry represents 30% of the total municipal solid waste deposited in landfills. Construction and demolition (C&D) waste has created negative socioeconomic and environmental impacts including contaminating ground water, emitting greenhouse gases, and adding more waste to scarce landfills. Literature is cited rework/waste generation due to ambiguity/errors in construction contract documents. Exculpatory clauses in contract documents are included in contractual agreements to prevent contractor claims, which often cause rework. After an extensive contract documents review, these clauses were categorized in to eight major areas. This paper (1) analyses expert opinions on pre-identified contractual clauses; and (2) introduces recommendations to minimize rework and waste in construction projects. It was found that the clauses related to quality, workmanship, and field quality control/inspection have the most potential to generate construction waste

Development of photo catalytic active building materials using zno nanorods

In many urban cities, the pollutants concentration at street level is quite high because of the dispersion of the exhaust generated by a large number of vehicles is hindered by surrounding tall buildings. Control of these pollutions has become a pressing need for the well-being of society. Many methods have been developed to control these pollutions. Currently, there is an increasing interest in the control of urban pollution level by using construction materials containing photocatalytic nanomaterials, without changing original performance of the building structure. The photocatalytic materials used in the building materials for the purification process are efficient to remove the contaminants such as NOx and VOC. Many works have been concerned with the application of different types of nanomaterials in photocatalytic processes. This paper presents the systematic study on the photocatalytic activity of ZnO nanorods on construction materials. In this method, ZnO nanorods were successfully synthesized by a wet chemical route. Systematic experiments were carried out to investigate the photocatalytic activity of the samples. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). It has been found that the ZnO nanoflowers contain many radial nanorods with the diameter of 100 nm and the length of 1–1.5 μm and these ZnO single-crystalline nanorods with wurtzite structure grow along the [ 0 0 1] direction. The formation mechanism of ZnO nanoflowers and nanorods was initially interpreted in terms of the general theory of the crystal nucleation and crystal growth direction. ZnO with flower-like morphology exhibited improved ability on the photocatalytic degradation

Accessibility and Usage of Digital Technologies among Academics for Research: A Case of Selected Humanities and Social Sciences Faculties in Sri Lankan Universities

The Humanities and Social Sciences (HSS) involve understanding the human experience and the relationships between individuals and groups in society. The adoption of digital technologies has challenged the discipline of HSS, creating an entirely new environment for the study of human activities. This research aims to explore the employment of digital tools, resources and services in HSS research. Further, the use of digital methods (DM) throughout the research process; the impact of COVID-19 on the use of DM in research; the constraints of using DM in research were tested. Both quantitative and qualitative data were collected from Colombo, Kelaniya and Sri Jayewardenepura universities targeting academics in Economics, English, English Language Teaching, Geography, History and Archeology, Buddhist Studies, Political Science, Sinhala, and Sociology. Considering the digital infrastructure facilities, most of the academics rated email (45.6%) and LMS services (46.7%) as excellent but maintenance provided by the institute was not adequate. Most academics rated good on access to data storage (37.9%); reference management software (27.5%); plagiarism detection software (29.1%); institutional repository (35.2%); and support to online publications (39.6%) provided by their institutes. 55.7% of surveyed academics in SS often use digital data collection methods while in the Humanities it was 43.4%. Online publishing was most often used by SS (50.9%) and only 39.5% by the Humanities. 53.8% of SS academics and 43.4% of humanities academics often use cloud storage. Findings confirmed the expansion of using digital research methods during the pandemic compared to the early pandemic situation. Collaborative research works, virtual conferences, citation databases and digital indexing were identified as popular trends. DOI: http://doi.org/10.31357/fhss/vjhss.v08i02.0

Mobilization of Iron Stored in Bacterioferritin Is Required for Metabolic Homeostasis in Pseudomonas aeruginosa

Iron homeostasis offers a significant bacterial vulnerability because pathogens obtain essential iron from their mammalian hosts, but host-defenses maintain vanishingly low levels of free iron. Although pathogens have evolved mechanisms to procure host-iron, these depend on well-regulated iron homeostasis. To disrupt iron homeostasis, our work has targeted iron mobilization from the iron storage protein bacterioferritin (BfrB) by blocking a required interaction with its cognate ferredoxin partner (Bfd). The blockade of the BfrB–Bfd complex by deletion of the bfd gene (Δbfd) causes iron to irreversibly accumulate in BfrB. In this study we used mass spectrometry and NMR spectroscopy to compare the proteomic response and the levels of key intracellular metabolites between wild type (wt) and isogenic ΔbfdP. aeruginosa strains. We find that the irreversible accumulation of unusable iron in BfrB leads to acute intracellular iron limitation, even if the culture media is iron-sufficient. Importantly, the iron limitation and concomitant iron metabolism dysregulation trigger a cascade of events that lead to broader metabolic homeostasis disruption, which includes sulfur limitation, phenazine-mediated oxidative stress, suboptimal amino acid synthesis and altered carbon metabolism

Detection and Minimization of Malware by Implementing AI in SMEs

The malware can threaten personal privacy by opening backdoors for attackers to access user passwords, IP addresses, banking information, and other personal data, whilst some malware extracts personal data and sends them to people unknown to the users. In this chapter, the authors will present recent case studies and discuss the privacy and security threats associated with different types of malwares. The small medium enterprises (SMEs) have a unique working model forming the backbone of the UK economy and malware affects SMEs’ organizations. Also, the use of Artificial Intelligence (AI) as both an offense and defense mechanism, for the hacker, and the end user will be investigated further. In conclusion, finding a balance between IT expertise and the costs of products that are able to help SMEs protect and secure their data will benefit the SMEs by using a more intelligent controlled environment with applied machine learning techniques and not compromising on costs will be discussed

Informed consent in Sri Lanka: A survey among ethics committee members

<p>Abstract</p> <p>Background</p> <p>Approval of the research proposal by an ethical review committee from both sponsoring and host countries is a generally agreed requirement in externally sponsored research.</p> <p>However, capacity for ethics review is not universal. Aim of this study was to identify opinions and views of the members serving in ethical review and ethics committees in Sri Lanka on informed consent, essential components in the information leaflet and the consent form.</p> <p>Methods</p> <p>We obtained ethical approval from UK and Sri Lanka. A series of consensus generation meetings on the protocol were conducted. A task oriented interview guide was developed. The interview was based on open-ended questionnaire. Then the participants were given a WHO checklist on informed consent and requested to rate the items on a three point scale ranging from extremely important to not important.</p> <p>Results</p> <p>Twenty-nine members from ethics committees participated. Majority of participants (23), believed a copy of the information leaflet and consent form, should accompany research proposal. Opinions about the items that should be included in the information leaflets varied. Participants identified 18 criteria as requirements in the information leaflet and 19 for the consent form.</p> <p>The majority, 20 (69%), believed that all research need ethical approval but identified limited human resource, time and inadequate capacity as constraints. Fifteen (52%) believed that written consent is not required for all research. Verbal consent emerged as an alternative to written consent. The majority of participants rated all components of the WHO checklist as important.</p> <p>Conclusion</p> <p>The number of themes generated for the consent form (N = 18) is as many as for the information leaflet (N = 19) and had several overlaps. This suggests that the consent form should be itemized to reflect the contents covered in the information leaflet. The participants' opinion on components of the information leaflets and consent forms proved to be similar with WHO checklist on informed consent.</p

Dynamic model of basic oxygen steelmaking process based on multi-zone reaction kinetics : model derivation and validation

A multi-zone kinetic model coupled with a dynamic slag generation model was developed for the simulation of hot metal and slag composition during the BOF operation. The three reaction zones, (i) jet impact zone (ii) slag-bulk metal zone (iii) slag-metal-gas emulsion zone were considered for the calculation of overall refining kinetics. In the rate equations, the transient rate parameters were mathematically described as a function of process variables. A micro and macroscopic rate calculation methodology (micro-kinetics and macro-kinetics) were developed to estimate the total refining contributed by the recirculating metal droplets through the slag-metal emulsion zone. The micro-kinetics involves developing the rate equation for individual droplets in the emulsion. The mathematical models for the size distribution of initial droplets, kinetics of simultaneous refining of elements, the residence time in the emulsion, dynamic interfacial area change were established in the micro-kinetic model. In the macro-kinetics calculation, a droplet generation model was employed and the total amount of refining by emulsion was calculated by summing the refining from the entire population of returning droplets. A dynamic FetO generation model based on oxygen mass balance was developed and coupled with the multi-zone kinetic model. The effect of post combustion on the evolution of slag and metal composition was investigated. The model was applied to a 200-ton top blowing converter and the simulated value of metal and slag was found to be in good agreement with the measured data. The post-combustion ratio was found to be an important factor in controlling FetO content in the slag and the kinetics of Mn and P in a BOF process

Syntheses and Electronic Properties of Rhodium(III) Complexes Bearing a Redox-Active Ligand

A series of rhodium(III) complexes of the redox-active ligand, H(L = bis(4-methyl-2-(1H-pyrazol-1-yl)phenyl)amido), was prepared, and the electronic properties were studied. Thus, heating an ethanol solution of commercial RhCl3·3H2O with H(L) results in the precipitation of insoluble [H(L)]RhCl3, 1. The reaction of a methanol suspension of [H(L)]RhCl3 with NEt4OH causes ligand deprotonation and affords nearly quantitative yields of the soluble, deep-green, title compound (NEt4)[(L)RhCl3]·H2O, 2·H2O. Complex 2·H2O reacts readily with excess pyridine, triethylphosphine, or pyrazine (pyz) to eliminate NEt4Cl and give charge-neutral complexes trans-(L)RhCl2(py), trans-3, trans-(L)RhCl2(PEt3), trans- 4, or trans-(L)RhCl2(pyz), trans-5, where the incoming Lewis base is trans- to the amido nitrogen of the meridionally coordinating ligand. Heating solutions of complexes trans-3 or trans-4 above about 100 °C causes isomerization to the appropriate cis-3 or cis-4. Isomerization of trans-5 occurs at a much lower temperature due to pyrazine dissociation. Cis-3 and cis- 5 could be reconverted to their respective trans- isomers in solution at 35 °C by visible light irradiation. Complexes [(L)Rh(py)2Cl](PF6), 6, [(L)Rh(PPh3)(py)Cl](PF6), 7, [(L)Rh(PEt3)2Cl](PF6), 8, and [(L)RhCl(bipy)](OTf = triflate), 9, were prepared from 2·H2O by using thallium(I) salts as halide abstraction agents and excess Lewis base. It was not possible to prepare dicationic complexes with three unidentate pyridyl or triethylphosphine ligands; however, the reaction between 2, thallium(I) triflate, and the tridentate 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine (ttpy) afforded a high yield of [(L)Rh(ttpy)]- (OTf)2, 10. The solid state structures of nine new complexes were obtained. The electrochemistry of the various derivatives in CH2Cl2 showed a ligand-based oxidation wave whose potential depended mainly on the charge of the complex, and to a lesser extent on the nature and the geometry of the other supporting ligands. Thus, the oxidation wave for 2 with an anionic complex was found at +0.27 V versus Ag/AgCl in CH2Cl2, while those waves for the charge-neutral complexes 3−5 were found between +0.38 to +0.59 V, where the cis- isomers were about 100 mV more stable toward oxidation than the trans- isomers. The oxidation waves for 6−9 with monocationic complexes occurred in the range +0.74 to 0.81 V while that for 10 with a dicationic complex occurred at +0.91 V. Chemical oxidation of trans-3, cis-3, and 8 afforded crystals of the singly oxidized complexes, [trans- (L)RhCl2(py)](SbCl6), cis-[(L)RhCl2(py)](SbCl4)·2CH2Cl2, and [(L)Rh(PEt3)2Cl](SbCl6)2, respectively. Comparisons of structural and spectroscopic features combined with the results of density functional theory (DFT) calculations between nonoxidized and oxidized forms of the complexes are indicative of the ligand-centered radicals in the oxidized derivatives

Cysteamine Inhibits Glycine Utilisation and Disrupts Virulence in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a major opportunistic human pathogen which employs a myriad of virulence factors. In people with cystic fibrosis (CF) P. aeruginosa frequently colonises the lungs and becomes a chronic infection that evolves to become less virulent over time, but often adapts to favour persistence in the host with alginate-producing mucoid, slow-growing, and antibiotic resistant phenotypes emerging. Cysteamine is an endogenous aminothiol which has been shown to prevent biofilm formation, reduce phenazine production, and potentiate antibiotic activity against P. aeruginosa, and has been investigated in clinical trials as an adjunct therapy for pulmonary exacerbations of CF. Here we demonstrate (for the first time in a prokaryote) that cysteamine prevents glycine utilisation by P. aeruginosa in common with previously reported activity blocking the glycine cleavage system in human cells. Despite the clear inhibition of glycine metabolism, cysteamine also inhibits hydrogen cyanide (HCN) production by P. aeruginosa, suggesting a direct interference in the regulation of virulence factor synthesis. Cysteamine impaired chemotaxis, lowered pyocyanin, pyoverdine and exopolysaccharide production, and reduced the toxicity of P. aeruginosa secreted factors in a Galleria mellonella infection model. Thus, cysteamine has additional potent anti-virulence properties targeting P. aeruginosa, further supporting its therapeutic potential in CF and other infections