These days, an increase in terrorist attacks and advanced techniques for creating small explosive devices using powerful, high-explosive materials are causing massive building collapses, economic losses, and death. Protecting and mitigating the effects of explosions on structures and the people in them have become important to scientists. In this article, the effect of different parameters on the target structure, such as standoff distance, charge weight, and the use of protection systems have been reviewed. It is not economical to design the main parts of the structure so that they can withstand different hazards, therefore the use of different protection systems and materials such as walls, fences, sacrificial claddings, sandwich panels, and FRP, to mitigate the blast pressure and diffracted waves, and the results of their analysis have been discussed. The role of these protection systems is to absorb high kinetic energy in the form of strain energy through deformation. It is sometimes possible to replace these systems with a new one after failure at a lower cost than structures without a protection system. This paper presents an overview for beginner researchers to study the effects of the explosion on the structures and investigate solutions to reduce these harmful effects and protect the structures, and their inhabitants.

The aim of this study was to use meta-analysis to identify the enteric methane (CH4) Mitigation strategy that reduced CH4 emission without lowering production. To this end, a database initially developed was updated, compiling data from 61 publications (233 experiments) for various observations in dairy cattle on effects of hydrogen sink (H-sink), ionophore, lipid and concentrate feeds inclusion on enteric CH4 produc-tion, milk production and milk composition from dair cattle. There was no significant effect (P>0. 05) of H-sink and ionophore feeds inclusion on CHy4 production while supplementation of lipid and concentrate considerably suppressed CH4 production (P<0. 05). CH4 production per kg milk produced was not de-pressed with H-sink treatment (P<0. 05). Lipids lightly increased CH4 production per kg milk from 26. 19 g kg− 1 for control to 29. 12 g kg− 1 for treatment (P>0. 05), while concentrate and ionophore feeds inclusion decreased CH4 production per kg milk with no significant effect (P>0. 05). There was a significant effect of concentrate on milk protein and milk yield, which increased from 23. 27 kg d− 1 for control to 26. 52 kg d− 1 for concentrate treated diet (P<0. 05). Milk yield and milk protein was not significantly affected with H-sink, ionophore and lipid feeds inclusion (P>0. 05). This meta-analysis demonstrates that lipid and concen-trate feeds inclusion reduced CH4 emissions from dairy cattle without lowering their production.

Reputation management systems are in wide-spread use to regulate collaborations in cooperative systems. Collusion is one of the most destructive malicious behaviors in which colluders seek to affect a reputation management system in an unfair manner. Many reputation systems are vulnerable to collusion, and some model-specific Mitigation methods are proposed to combat collusion. Detection of colluders is shown to be an NP-complete problem. In this paper, we propose the Colluders Similarity Measure (CSM) which is used by a heuristic clustering algorithm (the Colluders Detection Algorithm (CDA)) to detect colluders in O (n2m + n4) in which m and n are the total number of nodes and colluders, respectively. Furthermore, we propose an architecture to implement the algorithm in a distributed manner which can be used together with compatible reputation management systems. Implementation results and comparison with other Mitigation approaches show that our scheme prevents colluders from unfairly increasing their reputation and decreasing the reputation of the other nodes.

Semi-buried structures are most commonly used at first line of defense along the border between two countries. This demands investigation of their dynamic behaviour under blast loading. Herein, a semi-buried structure with foam sandwiched walls and buttresses to reduce the effect of blast is analysed. The effect of provision of different configurations of buttresses and foam core between two layers of structural wall subjected to explosive loadings is investigated using ABAQUS/Explicit® . Modelling of semi-buried structure is carried out by employing shell elements and soil is modelled using frequency independent spring-dashpot-mass model. The foam core is modelled using brick elements with reduced integration and volumetric hardening. Effect of strain rate on structural steel is modelled by employing Johnson-Cook (J-C) model. Results indicate that geometry of buttresses and foam core type governs structural response to dynamic loading. It is observed that inner wall of the structure is protected by foam provided in between walls and helps in blast Mitigation. Further, it is observed that design of such structures is dependent on the correct identification of buttresses type and isolation of inner wall of structure by provision of energy absorbing materials like foam.