Assessment of recycled concrete aggregates as a pavement material

Jayakody, Shiran,Gallage, Chaminda,Kumar, Arun Techno-Press 2014 Geomechanics & engineering Vol.6 No.3

Population increase and economic developments can lead to construction as well as demolition of infrastructures such as buildings, bridges, roads, etc resulting in used concrete as a primary waste product. Recycling of waste concrete to obtain the recycled concrete aggregates (RCA) for base and/or sub-base materials in road construction is a foremost application to be promoted to gain economical and sustainability benefits. As the mortar, bricks, glass and reclaimed asphalt pavement (RAP) present as constituents in RCA, it exhibits inconsistent properties and performance. In this study, six different types of RCA samples were subjected classification tests such as particle size distribution, plasticity, compaction test, unconfined compressive strength (UCS) and California bearing ratio (CBR) tests. Results were compared with those of the standard road materials used in Queensland, Australia. It was found that material type 'RM1-100/RM3-0' and 'RM1-80/RM3-20' samples are in the margin of the minimum required specifications of base materials used for high volume unbound granular roads while others are lower than that the minimum requirement.

Mitigating health risks associated with alcoholic beverages through metabolic engineering

Jayakody, L.N.,Lane, S.,Kim, H.,Jin, Y.S. Current Biology ; Elsevier Science Ltd 2016 Current opinion in biotechnology Vol.37 No.-

Epidemiological studies have established a positive relationship between the occurrence of cancer and consumption of alcoholic beverages. Metabolic engineering of brewing yeast to reduce potential carcinogenic compounds in alcoholic beverage is technically feasible as well as economically promising. This review presents the mechanisms of formation of potentially carcinogenic components in alcoholic beverages, such as formaldehyde, acetaldehyde, ethyl carbamate, acrylamide, and heavy metals, and introduces effective genetic perturbations to minimize the concentrations of these harmful components. As precise and effective genome editing tools for polyploid yeast are now available, we envision that yeast metabolic engineering might open up new research directions for improving brewing yeast in order to ensure product safety as well as to increase overall quality of alcoholic beverages.

Improvement of Regenerative Power of IPMSM by Total Loss Minimization Method

Jayakody Shreen,Kyung-min Lee(이경민) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.11

Secure and Efficient Context-Aware Localization of Drones in Urban Scenarios

Sharma, Vishal,Jayakody, Dushantha Nalin K.,You, Ilsun,Kumar, Ravinder,Li, Jun Institute of Electrical and Electronics Engineers 2018 IEEE communications magazine Vol.56 No.4

<P>Drone swarming involves multiple unmanned aerial vehicles (UAVs), which are able to manoeuver autonomously, providing a vast range of surveillance applications such as traffic evaluations, driver monitoring, disaster management, temporary network support, and pedestrian tracking. All these applications are an integral part of urban surveillance. In other words, cooperation between multiple drones can facilitate urban surveillance while being able to provide high-quality 3D visualization of the surroundings. This 3D representation is driven by the initiation of accurate and non-overlapping waypoints. Such efficient localization depends on the type of context and its security validation by the receiving entities. For example, a highly burdened context with negligible security is of limited use. This article presents a novel solution that is capable of securing the context information for sharing 3D waypoints between UAVs. The proposed approach achieves optimal localization through hierarchical context- aware aspect-oriented Petri nets while being powered by a novel drone context-exchange protocol for security validations.</P>

Experimental Investigations of the Strong Off-Resonant Comb(SORC) Pulse Sequence in ?? NQR

Kim,S.S.,Jayakody,J.R.P.,Marino,R.A. 國立 昌原大學校 基礎科學硏究所 1993 基礎科學硏究所論文集 Vol.4 No.-

The behavior of induction signals during steady-state pulse irradiations in ?? NQR was investigated experimentally. It has long been known that the signal response to a long sequence of rf pulses will dramatically increase for pulse spacings less than T₂. This increase in exponential, and can result in signals comparable to optimally prepared Free Induction Decays. Because these "SORC" signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these quasi steady-state signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the method.

Secure and Energy-Efficient Handover in Fog Networks Using Blockchain-Based DMM

Sharma, Vishal,You, Ilsun,Palmieri, Francesco,Jayakody, Dushantha Nalin K.,Li, Jun IEEE 2018 IEEE communications magazine Vol.56 No.5

<P>Modern fog network architectures, empowered by IoT applications and 5G communications technologies, are characterized by the presence of a huge number of mobile nodes, which undergo frequent handovers, introducing a significant load on the involved network entities. Considering the distributed and flat nature of these architectures, DMM can be the only viable option for efficiently managing handovers in these scenarios. The existing DMM solutions are capable of providing smooth handovers, but lack robustness from the security point of view. Indeed, DMM depends on external mechanisms for handover security and uses a centralized device, which has obvious security and performance implications in flat architectures where hierarchical dependencies can introduce problems. We propose a new DMM schema based on the blockchain, capable of resolving hierarchical security issues without affecting the network layout, and also satisfying fully distributed security requirements with less consumption of energy.</P>

Experimental Investigations of the Strong Off-Resonant Comb ( SORC ) Pulse Scqucence in 14N NQR

S. S. Kim,J. R. P. Jayakody,R. A. Marino 기초과학연구소 1993 기초과학논문집 Vol.4 No.-

Metabolic Engineering of Probiotic <i>Saccharomyces boulardii</i>

Liu, Jing-Jing,Kong, In Iok,Zhang, Guo-Chang,Jayakody, Lahiru N.,Kim, Heejin,Xia, Peng-Fei,Kwak, Suryang,Sung, Bong Hyun,Sohn, Jung-Hoon,Walukiewicz, Hanna E.,Rao, Christopher V.,Jin, Yong-Su American Society for Microbiology 2016 Applied and environmental microbiology Vol.82 No.8

<P>Saccharomyces boulardii is a probiotic yeast that has been used for promoting gut health as well as preventing diarrheal diseases. This yeast not only exhibits beneficial phenotypes for gut health but also can stay longer in the gut than Saccharomyces cerevisiae. Therefore, S. boulardii is an attractive host for metabolic engineering to produce biomolecules of interest in the gut. However, the lack of auxotrophic strains with defined genetic backgrounds has hampered the use of this strain for metabolic engineering. Here, we report the development of well-defined auxotrophic mutants (leu2, ura3, his3, and trp1) through clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-based genome editing. The resulting auxotrophic mutants can be used as a host for introducing various genetic perturbations, such as overexpression or deletion of a target gene, using existing genetic tools for S. cerevisiae. We demonstrated the overexpression of a heterologous gene (lacZ), the correct localization of a target protein (red fluorescent protein) into mitochondria by using a protein localization signal, and the introduction of a heterologous metabolic pathway (xylose-assimilating pathway) in the genome of S. boulardii. We further demonstrated that human lysozyme, which is beneficial for human gut health, could be secreted by S. boulardii. Our results suggest that more sophisticated genetic perturbations to improve S. boulardii can be performed without using a drug resistance marker, which is a prerequisite for in vivo applications using engineered S. boulardii.</P>

A Novel Compact Ultra-Wideband Frequency-Selective Surface-Based Antenna for Gain Enhancement Applications

Din Iftikhar Ud,Ullah Waheed,Abbasi Nisar Ahmad,Ullah Sadiq,Shihzad Waleed,Khan Bilawal,Jayakody Dushantha Nalin K. 한국전자파학회 2023 Journal of Electromagnetic Engineering and Science Vol.23 No.2

This article presents a compact ultra-wideband (UWB) circular monopole antenna with a frequency-selective surface (FSS) for gain enhancement. The proposed antenna has a circular patch with circular cuts at the edges and is excited by a microstrip feed. The bottom plane is truncated and further modified by two triangular cuts at the sides and one rectangular cut in the middle to improve the radiation characteristics of the UWB antenna. The antenna is designed on an FR-4 substrate with a thickness of 1.6 mm, a relative permittivity of 4.3, and planner dimensions of 30 mm × 30 mm. To improve the proposed antenna’s gain, an FSS is designed that consists of periodic unit cells of metal printed on the upper layer of an FR-4 substrate with dimensions of 0.11λ × 0.11λ at the lowest operating frequency of 3.3 GHz. The FSS shows a very low transmission coefficient and linearly reducing reflection phase with increasing frequency over a frequency range of 3.3–10.8 GHz. The gain of the proposed antenna is increased from 3 dB to 8.1 dB at 9 GHz by placing the antenna on the FSS. Moreover, the prototype of the proposed antenna is fabricated, and the experimental results are measured, which show close agreements with simulated results. The FSS-based antenna has directional radiation patterns, making it a potential candidate for ground-penetrating radar and UWB applications.

Comparative transcriptome analysis of heat stress responsiveness between two contrasting ginseng cultivars

Jayakodi, Murukarthick,Lee, Sang-Choon,Yang, Tae-Jin The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.4

Background: Panax ginseng has been used in traditional medicine to strengthen the body and mental well-being of humans for thousands of years. Many elite ginseng cultivars have been developed, and ginseng cultivation has become well established during the last century. However, heat stress poses an important threat to the growth and sustainable production of ginseng. Efforts have been made to study the effects of high temperature on ginseng physiology, but knowledge of the molecular responses to heat stress is still limited. Methods: We sequenced the transcriptomes (RNA-Seq) of two ginseng cultivars, Chunpoong (CP) and Yunpoong (YP), which are sensitive and resistant to heat stress, respectively, after 1- and 3-week heat treatments. Differential gene expression and gene ontology enrichment along with profiled chlorophyll contents were performed. Results: CP is more sensitive to heat stress than YP and exhibited a lower chlorophyll content than YP. Moreover, heat stress reduced the chlorophyll content more rapidly in CP than in YP. A total of 329 heat-responsive genes were identified. Intriguingly, genes encoding chlorophyll a/b-binding proteins, WRKY transcription factors, and fatty acid desaturase were predominantly responsive during heat stress and appeared to regulate photosynthesis. In addition, a genome-wide scan of photosynthetic and sugar metabolic genes revealed reduced transcription levels for ribulose 1,5-bisphosphate carboxylase/oxygenase under heat stress, especially in CP, possibly attributable to elevated levels of soluble sugars. Conclusion: Our comprehensive genomic analysis reveals candidate loci/gene targets for breeding and functional studies related to developing high temperature-tolerant ginseng varieties.