Improvement of pavement foundation response with multi-layers of geocell reinforcement: Cyclic plate load test

Khalaj, Omid,Tafreshi, Seyed Naser Moghaddas,Mask, Bohuslav,Dawson, Andrew R. Techno-Press 2015 Geomechanics & engineering Vol.9 No.3

Comprehensive results from cyclic plate loading at a diameter of 300 mm supported by layers of geocell are presented. The plate load tests were performed in a test pit measuring $2000{\times}2000mm$ in plane and 700 mm in depth. To simulate half and full traffic loadings, fifteen loading and unloading cycles were applied to the loading plate with amplitudes of 400 and 800 kPa. The optimum embedded depth of the first layer of geocell beneath the loading plate and the optimum vertical spacing of geocell layers, based on plate settlement, are both approximately 0.2 times loading plate diameter. The results show that installation of the geocell layers in the foundation bed, increase the resilient behavior in addition to reduction of accumulated plastic and total settlement of pavement system. Efficiency of geocell reinforcement was decreased by increasing the number of the geocell layers for all applied stress levels and number of cycles of applied loading. The results of the testing reveal the ability of the multiple layers of geocell reinforcement to 'shakedown' to a fully resilient behavior after a period of plastic settlement except when there is little or no reinforcement and the applied cyclic pressure are large. When shakedown response is observed, then both the accumulated plastic settlement prior to a steady-state response being obtained and the resilient settlements thereafter are reduced. The use of four layers of geocell respectively decreases the total and residual plastic settlements about 53% and 63% and increases the resilient settlement 145% compared with the unreinforced case. The inclusion of the geocell layers also reduces the vertical stress transferred down through the pavement by distributing the load over a wider area. For example, at the end of the load cycle of the applied pressure of 800 kPa, the transferred pressure at the depth of 510 mm is reduced about 21.4%, 43.9%, 56.1% for the reinforced bases with one, two, and three layers of geocell, respectively, compared to the stress in the unreinforced bed.

Growth, Quality, and Physiological Characteristics of Gerbera (Gerbera jamesonii L.) Cut Flowers in Response to Different NO3‑:NH4+ Ratios

Mohammad Ali Khalaj,Shahram Kiani,Amir Hosein Khoshgoftarmanesh,Reihaneh Amoaghaie 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.4

We investigated the effects of different NO3¯:NH4+ratios in nutrient solution on the yield and growth ofgerbera (Gerbera jamesonii) cut flowers in soilless culture. Two cultivars of gerbera (red ‘Stanza’ and yellow ‘DoubleDutch’) were supplemented with four different NO3¯:NH4+ratios (100:0, 80:20, 60:40, and 40:60). Replacing 20%nitrate in the nutrient solution with ammonium resulted in the higher number of leaves per plant, highest fresh anddry weights of roots and shoots, greatest number of flowers, highest flower stalk diameter and flower disk diameter,longest vase life, highest fresh and dry weight of inflorescences, and highest relative water contents in petals comparedwith the control. Decreasing the NO3¯:NH4+ratio to 60:40 caused a considerable reduction in plant growth and biomass. The chlorophyll and carotenoid contents, as well as catalase (CAT) and peroxidase (POX) activity, increased withincreasing proportion of ammonium-to-nitrate in the nutrient solution. The results suggest that a NO3¯:NH4+ratio of80:20 should be used for gerbera cut flower production to achieve the highest growth and quality.

Optimum QoS Classes in Interworking of Next Generation Networks

Khoshnevis, Behrouz,Khalaj, Babak H. The Korea Institute of Information and Commucation 2007 Journal of communications and networks Vol.9 No.4

In this paper, we consider the problem of optimum selection of quality-of-service(QoS) classes in interworking between the networks in a next-generation-network(NGN) environment. After introducing the delay-cost and loss-cost characteristics, we discuss the time-invariant(TI) and time-variant(TV) scenarios. For the TI case, we show that under nearly lossless transmission condition, each network can make its own optimization regardless of other networks. For the TV case, we present sufficient conditions under which the optimum QoS class of each network can be considered fixed with respect to time without considerable degradation in the optimization target. Therefore, under the conditions presented in this paper, the QoS of a flow in each network can be determined solely by considering the characteristics of that network and this QoS class can be held fixed during the flow period.

Optimum QoS Classes in Interworking of Next Generation Networks

B. Khoshnevis,B. H. Khalaj 한국통신학회 2007 Journal of communications and networks Vol.9 No.4

Acute Necrotizing Encephalopathy in Adult Patients With COVID-19: A Systematic Review of Case Reports and Case Series

Shaghayegh Karami,Fattaneh Khalaj,Houman Sotoudeh,Zohreh Tajabadi,Ramin Shahidi,Mohammad Amin Habibi,Mahsa Shirforoush Sattari,Amir Azimi,Seyed Ali Forouzannia,Romina Rafiei,Hamid Reihani,Reza Nemati 대한신경과학회 2023 Journal of Clinical Neurology Vol.19 No.6

Background and Purpose Acute necrotizing encephalopathy (ANE) is a rare neurological disorder that is often associated with viral infections. Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a few COVID-19-associated ANE cases have been reported. Since very little is known about ANE, the present study aimed to determine the clinical, biochemical, and radiological characteristics of affected patients. Methods A search was conducted on PubMed, Scopus, Embase, and Web of Science databases for articles published up to August 30, 2022 using relevant keywords. Case reports and series in the English language that reported ANE in adult patients with COVID-19 confirmed by reverse transcription polymerase chain reaction were included in this study. Data on the demographic, clinical, laboratory, and radiological characteristics of patients were extracted and analyzed using the SPSS software (version 26). Results The study included 30 patients (18 males) with COVID-19 and ANE who were aged 49.87±18.68 years (mean±standard deviation). Fever was the most-prevalent symptom at presentation (66.7%). Elevated C-reactive protein was observed in the laboratory assessments of 13 patients. Computed tomography and magnetic resonance imaging were the most-common radiological modalities used for brain assessments. The most commonly prescribed medications were methylprednisolone (30%) and remdesivir (26.7%). Sixteen patients died prior to discharge. Conclusions The diagnosis of COVID-19-associated ANE requires a thorough knowledge of the disease. Since the clinical presentations of ANE are neither sensitive nor specific, further laboratory and brain radiological evaluations will be needed to confirm the diagnosis. The suspicion of ANE should be raised among patients with COVID-19 who present with progressive neurological symptoms.

QoSNC: A Novel Approach to QoS-Based Network Coding for Fixed Networks

Salavati, Amir Hesam,Khalaj, Babak Hossein,Crespo, Pedro M.,Aref, Mohammad Reza The Korea Institute of Information and Commucation 2010 Journal of communications and networks Vol.12 No.1

In this paper, we present a decentralized algorithm to find minimum cost quality of service (QoS) flow subgraphs in network coded multicast schemes. The main objective is to find minimum cost subgraphs that also satisfy user-specified QoS constraints, specifically with respect to rate and delay demands. We consider networks with multiple multicast sessions. Although earlier network coding algorithms in this area have demonstrated performance improvements in terms of QoS parameters, the proposed QoS network coding approach provides a framework that guarantees QoS constraints are actually met over the network.

QoSNC: A Novel Approach to QoS-Based Network Coding for Fixed Networks

Amir Hesam Salavati,Babak Hossein Khalaj,Pedro M. Crespo,Mohammad Reza Aref 한국통신학회 2010 Journal of communications and networks Vol.12 No.1

In this paper, we present a decentralized algorithm to find minimum cost quality of service (QoS) flow subgraphs in network coded multicast schemes. The main objective is to find minimum cost subgraphs that also satisfy user-specified QoS constraints,specifically with respect to rate and delay demands. We consider networks with multiple multicast sessions. Although earlier network coding algorithms in this area have demonstrated performance improvements in terms of QoS parameters, the proposed QoS network coding approach provides a framework that guarantees QoS constraints are actually met over the network.

Microstructure and Micromorphology of Cu/Co Nanoparticles: Surface Texture Analysis

Ştefan Ţălu,Miroslaw Bramowicz,Slawomir Kulesza,Atefeh Ghaderi,Vali Dalouji,Shahram Solaymani,Zahra Khalaj 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.5

This paper analyses the three-dimensional (3-D) surface texture ofCu/Co thin films deposited by DC-Magnetron sputtering methodon the silicon substrates. The prepared Cu/Co nanoparticles wereused as research materials. Three groups of samples were depositedon silicon substrates in the argon atmosphere and gradually cooleddown to room temperature. The crystalline structures and elementalcompositions were analyzed by X-ray diffraction (XRD) spectrumwith conventional Bragg-Brentano geometry. X-ray diffractionprofile indicates that Co and Cu interpenetrating crystallinestructures are formed in these films. The sample surface imageswere recorded using atomic force microscopy (AFM) and analyzedby means of the fractal geometry. Statistical, fractal and functionalsurface properties of prepared samples were computed to describemajor characteristics of the spatial surface texture of Cu/Conanoparticles. Presented deposition method is a versatile, costeffective,and simple method to synthesize nano- and microstructuresof Cu/Co thin films. This type of 3-D morphology allows tounderstand the structure/property relationships and to investigatedefect-related properties of Cu/Co nanoparticles. Presented resultsconfirm the possibility of preparing high-quality Cu/Co nanoparticlesvia DC-Magnetron sputtering method on silicon substrates.