Formal Modeling and Verification of a Blockchain-Based Crowdsourcing Consensus Protocol

Crowdsourcing is an effective technique that allows humans to solve complex problems that are hard to accomplish by automated tools. Some significant challenges in crowdsourcing systems include avoiding security attacks, effective trust management, and ensuring the system’s correctness. Blockchain is a promising technology that can be efficiently exploited to address security and trust issues. The consensus protocol is a core component of a blockchain network through which all the blockchain peers achieve an agreement about the state of the distributed ledger. Therefore, its security, trustworthiness, and correctness have vital importance. This work proposes a Secure and Trustworthy Blockchain-based Crowdsourcing (STBC) consensus protocol to address these challenges. Model checking is an effective and automatic technique based on formal methods that is utilized to ensure the correctness of STBC consensus protocol. The proposed consensus protocol’s formal specification is described using Communicating Sequential Programs (CSP#). Safety, fault tolerance, leader trust, and validators’ trust are important properties for a consensus protocol, which are formally specified through Linear Temporal Logic (LTL) to prevent several security attacks, such as blockchain fork, selfish mining, and invalid block insertion. Process Analysis Toolkit (PAT) is utilized for the formal verification of the proposed consensus protocol

Studies On the Role of Fungal Strains in Bioremediation of Dyes Isolated from Textile Effluents

Fungal strains are widely used for the cleaning of soil, sediments, groundwater, surface water, and the ecosystem. The presence of extracellular enzymes in fungi facilitates the process of bioremediation of textile dyes. This study was conducted to observe the quality of water being released from textile dyes industries and also the capability of some fungal strains which can remediate these dyes by showing the tendency of their resistance. Samples of water were collected from the polluted area surrounding the textile dyeing industries in Lahore. In the process of isolation, Potato Dextrose Agar (PDA) medium was used to verify the fungal growth. Fungal strains were purified, and the morphological characterization of fungal strains was carried out at 10X and 100X by using a magnification microscope. The fungal strains, such as Aspergillus niger, Aspergillusoryzae, and Aspergillusflavus were identified. The stress of four types of dyes was given to each fungal strain. The results showed that Aspergillusoryzae was one of the most stable, non-toxic, and resistant fungal species against the high stress of dyes as compared to other specie

Breakup and instability analysis of compound liquid jets

This study deals with the temporal instability of compound liquid jets. The presence of an outer column of liquid which is totally immiscible from the inner fluid introduces many interesting features in jet breakup dynamics. The governing equations which model the behavior of a compound jet are in general rather complex due to the presence of multiple free surfaces and different fluids. However, an asymptotic approach can be used to yield a set of one dimensional equations which greatly simplify the resulting analysis. We perform linear and nonlinear analysis to reveal many interesting features of the compound liquid jets. The influence of gravity on the instability and breakup of inviscid and viscous compound jets is also considered. Additionally, we estimate the theoretical breakup lengths, breakup time and droplet sizes of such jets for varying key parameters

Analyzing an Appropriate Blend of Face-to-Face, Offline and Online Learning Approaches for the In-Service Vocational Teacher’s Training Program

Blended learning approaches are considered as the most viable for the delivery of training to remote areas and accessing learners at a mass level. Blended learning is a combination of different learning approaches to facilitate the learners’ needs. The National Vocational and Technical Training Commission (NAVTTC) conducted an in-service vocational teachers’ training program through blended learning approaches in Pakistan. This study aimed to find the appropriate blend of face-to-face, online, and offline learning approaches for the training of in-service teachers in Pakistan. A mixed methods research approach was adopted. A survey collected data from 781 in-service vocational teachers who participated in training programs through blended learning approaches. The ANOVA test was applied to find the difference of the training participants’ attitude toward different modes of learning. It was found that trainees had more positive attitude toward a face-to-face learning approach than online and the online learning approach than offline learning. Semi-structured interviews were also conducted with training participants, admission and placement officers, and principals. They also endorsed that face-to-face learning approaches must be given more weight than online, and the online approach should have more weight than the offline approach. This study has practical implications for technical education and vocational training (TVET) institutes in developing countries such as Pakistan to design blended learning approaches for the training of in-service vocational teachers. Future research may be conducted on the effectiveness of in-service vocational education teachers through blended learning

Use of Natural Antimicrobial Agents: A Safe Preservation Approach

Microorganism contamination at various stages of food chain is one of the major causes for food spoilage that ultimately leads to food waste, increasing food insecurity issues and substantial economic losses. Various synthetic chemical preservatives are being used to control microbial food spoilage and to extend product shelf life. Researchers and consumers are discouraging the use of synthetic preservatives due to their negative health impacts. Naturally occurring antimicrobials have gained attention among researchers and food manufacturer due to their safety and nontoxic status. Natural preservatives are easy to obtain from plants, animals and microbes. These naturally occurring antimicrobial agents can be isolated from indigenous sources using various advanced techniques. Natural preservatives such as nisin, essential oils, and natamycin have effective potential against spoilage and pathogenic microorganisms. The regulations regarding the use of these naturally occurring preservatives are not well defined in some developing countries. This chapter focuses on source and their potential role, antimicrobial mechanism in food preservation, and current knowledge on the subject

Analyzing an Appropriate Blend of Face-to-Face, Offline and Online Learning Approaches for the In-Service Vocational Teacher’s Training Program

Blended learning approaches are considered as the most viable for the delivery of training to remote areas and accessing learners at a mass level. Blended learning is a combination of different learning approaches to facilitate the learners’ needs. The National Vocational and Technical Training Commission (NAVTTC) conducted an in-service vocational teachers’ training program through blended learning approaches in Pakistan. This study aimed to find the appropriate blend of face-to-face, online, and offline learning approaches for the training of in-service teachers in Pakistan. A mixed methods research approach was adopted. A survey collected data from 781 in-service vocational teachers who participated in training programs through blended learning approaches. The ANOVA test was applied to find the difference of the training participants’ attitude toward different modes of learning. It was found that trainees had more positive attitude toward a face-to-face learning approach than online and the online learning approach than offline learning. Semi-structured interviews were also conducted with training participants, admission and placement officers, and principals. They also endorsed that face-to-face learning approaches must be given more weight than online, and the online approach should have more weight than the offline approach. This study has practical implications for technical education and vocational training (TVET) institutes in developing countries such as Pakistan to design blended learning approaches for the training of in-service vocational teachers. Future research may be conducted on the effectiveness of in-service vocational education teachers through blended learning

Discourse and Corpus based Analysis of Doctor-Patient Conversation in the Context of Pakistani Hospitals

This study undertakes the analysis of the communicative patterns between doctors and patients by applying Sinclair and Coulthard’s (1975) IRF (Initiation, Response and Follow-up) Model. The focus of this study is to investigate the discourse features of the language used between the doctors and the patients in a hospital setting. It further explores how doctors and patients make sense of each other’s talk. The data was electronically recorded and then transcribed in terms of Dijk’s transcription key with the modification. IRF structural patterns of the original model were applied with modification due to change in the context in which the communication between the participants of the discourse took place. The discourse structure found in the data varied from that of the classroom discourse investigated by Sinclair and Coulthard. This study showed significant difference in the use of language in spoken and written form between the doctors and the patients. It also revealed that commonality, solidarity and familiarity in exchange structure was lacking in the communication between the doctors and patients which resulted in misunderstanding of the talk

Discourse and Corpus based Analysis of Doctor-Patient Conversation in the Context of Pakistani Hospitals

This study undertakes the analysis of the communicative patterns between doctors and patients by applying Sinclair and Coulthard’s (1975) IRF (Initiation, Response and Follow-up) Model. The focus of this study is to investigate the discourse features of the language used between the doctors and the patients in a hospital setting. It further explores how doctors and patients make sense of each other’s talk. The data was electronically recorded and then transcribed in terms of Dijk’s transcription key with the modification. IRF structural patterns of the original model were applied with modification due to change in the context in which the communication between the participants of the discourse took place. The discourse structure found in the data varied from that of the classroom discourse investigated by Sinclair and Coulthard. This study showed significant difference in the use of language in spoken and written form between the doctors and the patients. It also revealed that commonality, solidarity and familiarity in exchange structure was lacking in the communication between the doctors and patients which resulted in misunderstanding of the talk

Willingness to pay for vaccination against hepatitis b and its determinants: the case study of an industrial district of Pakistan

Willingness to pay (WTP) for vaccination of hepatitis disease is a good measure to monetize the physical effects of a disease into monetary values. Therefore, the present study aims to find the willingness to pay for self-paid vaccines for hepatitis and its determinants in an industrial district Faisalabad, Pakistan. Primary data was collected from 200 nonpatients of hepatitis which were personally interviewed by using convenient sampling method. A scenario was presented to the selected respondents by using CVM technique. The respondents were randomly assigned to pre-chosen payment bids defined on the basis of prevailing market rates for vaccination at the time of survey. The multivariate linear regression was used to find the determinants of WTP. The results show that females are slightly more willing to pay as compared to males. The variables like age, income and awareness about hepatitis have positive impact on WTP for vaccination of hepatitis disease. About 57.3 percent people belonging to low income group wanted vaccination free of cost in Pakistan.Government should launch free vaccination programs for the most vulnerable group (poor) and must launch awareness campaign to increase knowledge about disease