524 research outputs found

    Distributed Beamforming with Wirelessly Powered Relay Nodes

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    This paper studies a system where a set of NN relay nodes harvest energy from the signal received from a source to later utilize it when forwarding the source's data to a destination node via distributed beamforming. To this end, we derive (approximate) analytical expressions for the mean SNR at destination node when relays employ: i) time-switching based energy harvesting policy, ii) power-splitting based energy harvesting policy. The obtained results facilitate the study of the interplay between the energy harvesting parameters and the synchronization error, and their combined impact on mean SNR. Simulation results indicate that i) the derived approximate expressions are very accurate even for small NN (e.g., N=15N=15), ii) time-switching policy by the relays outperforms power-splitting policy by at least 33 dB.Comment: 4 pages, 3 figures, accepted for presentation at IEEE VTC 2017 Spring conferenc

    A Quantum Key Distribution Network Through Single Mode Optical Fiber

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    Quantum key distribution (QKD) has been developed within the last decade that is provably secure against arbitrary computing power, and even against quantum computer attacks. Now there is a strong need of research to exploit this technology in the existing communication networks. In this paper we have presented various experimental results pertaining to QKD like Raw key rate and Quantum bit error rate (QBER). We found these results over 25 km single mode optical fiber. The experimental setup implemented the enhanced version of BB84 QKD protocol. Based upon the results obtained, we have presented a network design which can be implemented for the realization of large scale QKD networks. Furthermore, several new ideas are presented and discussed to integrate the QKD technique in the classical communication networks.Comment: This paper has been submitted to the 2006 International Symposium on Collaborative Technologies and Systems (CTS 2006)May 14-17, 2006, Las Vegas, Nevada, US

    Critical success factors in implementing an e-rostering system in a healthcare organisation

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    Effective and efficient staff scheduling has always been a challenging issue, especially in health service organisations. Both the extremes of staff shortage and overage have an adverse impact on the performance of healthcare organisations. In this case, an electronic and systematic staff scheduling (e-rostering) system is the often seen as the best solution. Unless an organisation has an effective implementation of such a system, possible cost savings, efficiency, and benefits could be minimal. This study is aimed to research key success factors for the successful effective implementation of an electronic rostering system, especially at healthcare organisations. A case study research method was used to evaluate critical success factors for effectively implementing an e-rostering system. The data were collected through interviews and observations. The findings indicate that technical support, an effective policy, leadership, clear goals and objectives, gradual change, evidence of the advantages of the new system, senior management support, and effective communication are the critical success factors in implementing an e-rostering system in healthcare organisations. Prior to this study, no such factors were grounded in the current context, so this research would help in bridging the gap towards effective implementation of an e-rostering system in the healthcare sector. This research also suggests future studies in different cultures and contexts

    Surgical Management of Soft Tissue Sarcoma

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    Background: To study the management patternof soft tissue sarcomas in a tertiary care settingMethods: In this descriptive study patients whowere operated for soft tissue masses were included.Intra-operative findings, procedure details andpostoperative orders were recorded. Postoperativechemo-radiotherapy records were reviewed andrecorded. Depth of the tumour was grouped asdeeper or superficial than 5 cm. The follow uprecords were accessed from the outpatientdepartment and any surgical complications wererecorded up to three years.Staging was done usingclinical and radiological criteria taking into accountthe histological grade,tumour size , depth, locallymph node invasion and metastasis.Surgicalprocedure for removal of STS are wide local excision(WLE), intralesional excision (IE) or tumordebulking, marginal excision (ME) and radicalexcision (RE).Results: Sixty eight patients with mean age of 43.0± 17.258 SD were diagnosed as cases of soft tissuesarcomas. Male to female ratio was 3.25:1.The mostcommon histopathological variety was malignantfibrous histiocytoma (35.3%) , followed byRhabdomyosarcoma(30%). Most common involvedsite was lower limbs (35.3%).Wide local excision wasperformed in majority (82.4%) . Most commonpostop complication was wound infection (10.3%)Conclusion: Clinicians must be agile about thenature of these tumours and their referral to aspecialist surgeon for further management. Promptdiagnosis, accurate investigations and earlyintervention will benefit the patients and help usunderstand this disease entity

    Deferred Prosecution Agreement: A tool to deter environmental crime by corporations in Malaysia

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    The commission of the corporate environmental crime is on the rise in Malaysia. This may be due to the existing legal system which stipulates minimal punishments and results in crime repetition. This study adopted a qualitative method through doctrinal legal research given the crucial need to assess and benefit from the prevailing implementation of deferred prosecution agreement (DPA) in another jurisdiction. This study aims to explore the suitability of DPA as an alternative tool to deter corporate environmental crime in Malaysia. Findings from the study demonstrated that DPA could effectively prevent corporate environmental crime in Malaysia. Keywords: Corporate Environmental Crime; Prosecution of Corporate Environmental Crime; Malaysian Legal System; Deferred Prosecution Agreement eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7i22.415

    Seed priming with different agents mitigate alkalinity induced oxidative damage and improves maize growth

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    Soil alkalinity is a severe threat to crop production globally as it markedly retards plant growth. Different techniques are used to mitigate alkaline stress, but priming techniques are considered the most appropriate. The current study was carried out in complete randomized design (CRD) to evaluate the effect of different priming techniques on maize crop grown under different levels of alkalinity stress. The experiment was comprised of different treatments of alkalinity stress (AS) including, control, 6 dS m-1 and 12 dS m-1 and different priming techniques including control, hydro-priming (HP), osmo-priming (OP) with potassium nitrate: KNO3) and redox-priming (RP) with hydrogen peroxide (H2O2). Results indicated that alkalinity stress significantly reduced plant growth and biomass production and induced severe alterations in physiological attributes and antioxidant activities. Soil alkalinity significantly reduced the root and shoot growth and subsequent biomass production by increasing electrolyte leakage (70.60%), hydrogen peroxide (H2O2: 31.65%), malondialdehyde (MDA: 46.23%) and sodium (Na+) accumulation (22.76%) and reduction in photosynthetic pigments, relative water contents (RWC), total soluble proteins (TSP) and free amino acids, potassium (K+) accumulation. However, priming treatments significantly alleviated the alkalinity-induced toxic effects and improved plant growth. OP (KNO3) remained the top performing. It appreciably improved plant growth owing to the improved synthesis of photosynthetic pigments, better RWC (16.42%), TSP (138.28%), FAA (178.37%), and K+ accumulation (31.385) and improved antioxidant activities (APX and CAT) by favoring the Na+ exclusion and maintenance of optimum Na+/K+. In conclusion, KNO3 priming is an imperative seed priming practice to improve maize growth and biomass production under alkalinity stress

    SOLAR ASSISTED EVAPORATIVE COOLING BASED PASSIVE AIR-CONDITIONING SYSTEM FOR AGRICULTURAL AND LIVESTOCK APPLICATIONS

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    Solar-chimney assisted evaporative cooling based passive-air-conditioning (SCAC) system has been investigated for different climatic cities of Pakistan. Driving force of system is based on solar chimney and electric fan for day and night time operations, respectively. Ideal temperature and humidity zones are formulated for agricultural products’ storage and animals’ thermal comfort. Recent studies have proven the advancement of Maisotsenko Cycle (M-Cycle) in air-conditioning (AC) field; therefore, SCAC system utilizes M-Cycle conception in order to achieve dew-point cooling. On the basis of M-Cycle experimental data available via literature, study provides thermodynamic investigation of SCAC system for various conditions. Two simplified correlations are developed for performance evaluation of M-Cycle unit. Both correlations showed precise agreement with experimental data with R2 > 0.95. The SCAC system could achieve sensible load of AC efficiently for various applications; however, performance index varies according to climatic conditions. The SCAC system’s applicability was found limited in humid areas because of nature of M-Cycle operation. Therefore, it has been concluded that system may not be sustainable as standalone AC, but it can be a onvenient solution in order to reduce the AC load. Moreover, it can provide chilled ceiling for various applications with the low-cost operation. It can be efficiently utilized in most of the dry and moderate areas, whereas, the system’s applicability is limited in humid and water scared regions

    Investigation of input and output energy for wheat production : a comprehensive study for Tehsil Mailsi (Pakistan)

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    The global increasing food demand can be met by efficient energy utilization in mechanized agricultural productions. In this study, input–output energy flow along with CO2 emissions for different wheat production cases (C-I to C-V) were investigated to identify the one that is most energy-efficient and environment-friendly case. Data and information about input and output sources were collected from farmers through questionnaires and face-to-face interviews. Input and output sources were converted into energy units by energy equivalents while CO2 emissions were calculated by emission equivalents. Data envelopment analysis (DEA) was conducted to compare technical efficiencies of the developed cases for optimization of inputs in inefficient cases. Results revealed that case C-Ⅴ (higher inputs, larger fields, the tendency of higher fertilizer application and tillage operations) has the highest energy inputs and outputs than the rest of the cases. Moreover, it possesses the lowest energy use efficiency and energy productivity. The highest CO2 emissions (1548 kg-CO2/ha) referred to C-Ⅴ while lowest emissions per ton of grain yield were determined in C-Ⅳ (higher electricity water pumping, moderate energy input). The grain yield increases directly with input energy in most of the cases, but it does not guarantee the highest values for energy indices. C-Ⅲ (moderate irrigations, educated farmers, various fertilizer applications) was found as an optimum case because of higher energy indices like energy use efficiency of 4.4 and energy productivity of 153.94 kg/GJ. Optimum input and better management practices may enhance energy proficiency and limit the traditionally uncontrolled CO2 emissions from wheat production. Therefore, the agricultural practices performed in C-Ⅲ are recommended for efficient cultivation of wheat in the studied area.The global increasing food demand can be met by efficient energy utilization in mechanized agricultural productions. In this study, input–output energy flow along with CO2 emissions for different wheat production cases (C-I to C-V) were investigated to identify the one that is most energy-efficient and environment-friendly case. Data and information about input and output sources were collected from farmers through questionnaires and face-to-face interviews. Input and output sources were converted into energy units by energy equivalents while CO2 emissions were calculated by emission equivalents. Data envelopment analysis (DEA) was conducted to compare technical efficiencies of the developed cases for optimization of inputs in inefficient cases. Results revealed that case C-Ⅴ (higher inputs, larger fields, the tendency of higher fertilizer application and tillage operations) has the highest energy inputs and outputs than the rest of the cases. Moreover, it possesses the lowest energy use efficiency and energy productivity. The highest CO2 emissions (1548 kg-CO2/ha) referred to C-Ⅴ while lowest emissions per ton of grain yield were determined in C-Ⅳ (higher electricity water pumping, moderate energy input). The grain yield increases directly with input energy in most of the cases, but it does not guarantee the highest values for energy indices. C-Ⅲ (moderate irrigations, educated farmers, various fertilizer applications) was found as an optimum case because of higher energy indices like energy use efficiency of 4.4 and energy productivity of 153.94 kg/GJ. Optimum input and better management practices may enhance energy proficiency and limit the traditionally uncontrolled CO2 emissions from wheat production. Therefore, the agricultural practices performed in C-Ⅲ are recommended for efficient cultivation of wheat in the studied area.King Saud University, Riyadh, Saudi Arabi

    Melatonin Induced Cold Tolerance in Plants: Physiological and Molecular Responses

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    Cold stress is one of the most limiting factors for plant growth and development. Cold stress adversely affects plant physiology, molecular and biochemical processes by determining oxidative stress, poor nutrient and water uptake, disorganization of cellular membranes and reduced photosynthetic efficiency. Therefore, to recover impaired plant functions under cold stress, the application of bio-stimulants can be considered a suitable approach. Melatonin (MT) is a critical bio-stimulant that has often shown to enhance plant performance under cold stress. Melatonin application improved plant growth and tolerance to cold stress by maintaining membrane integrity, plant water content, stomatal opening, photosynthetic efficiency, nutrient and water uptake, redox homeostasis, accumulation of osmolytes, hormones and secondary metabolites, and the scavenging of reactive oxygen species (ROS) through improved antioxidant activities and increase in expression of stress-responsive genes. Thus, it is essential to understand the mechanisms of MT induced cold tolerance and identify the diverse research gaps necessitating to be addressed in future research programs. This review discusses MT involvement in the control of various physiological and molecular responses for inducing cold tolerance. We also shed light on engineering MT biosynthesis for improving the cold tolerance in plants. Moreover, we highlighted areas where future research is needed to make MT a vital antioxidant conferring cold tolerance to plants
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