Day1

  • University of Cambridge, United Kingdom
  • Title:Joint Mode Selection and Power Control for D2D Underlaid Cellular Networks
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Abstract:

Device-to-Device (D2D) communication is a promising technology that can potentially enhance both spectral and energy efficiency of cellular networks. This paper develops an innovative strategy in terms of Mode Selection and Power Control in Device-to-Device (D2D) communications underlaying uplink cellular networks with one base station (BS). In fact, the important issue in D2D communications is the Radio Resource Management Algorithms (RRM), since it covers the concepts of D2D transmit power control, mode selection and resource allocation. Our proposed solution encompasses both mode selection (choosing between cellular and D2D mode) and power control. This solution aims at ensuring to the cellular users a sufficient coverage probability, based on a predetermined Signal to Noise Ratio (SINR) threshold, while including as many D2D links as possible. Two Sufficient conditions based on both cellular and D2D users conditions, are suggested and compared in this paper, in order to enhance a proposed centralized power control problem. Two algorithms are carried out to ensure both mode selection and power control. Finally, simulations are carried out to show the effectiveness of the two proposed approaches.

Biography:

Sameh Najeh has received her Bachelor Degree in Mathematics in 1999, from the University of Sciences of Tunis, Tunisia, and Master and Ph.D. Degrees in Telecommunications from the National Engineering School of Tunis (ENIT), Tunisia, in 2002 and 2008, respectively. She also had her university accreditation in July 2020. Currently, Sameh is an Assistant Professor at SUP’COM of Tunis, Tunisia. Her research interests lie in signal processing and Digital communication. Currently, she is focusing on Radio Resource Mangement in 5G using game theory.

  • University of Reims Champagne Ardenne (URCA), France
  • Title:Geometrical Impact on Physical Properties of Mesoscopic Scale Thick Material Thin Films.
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Abstract:
A real material thin film never exhibits a perfect or ideal geometrical shape, regardless of its formation conditions. This is mainly depicted by its unavoidable bulk usually represented by its thickness (d ≠ 0) and its surface irregularities part commonly considered in term of surface roughness ( σ
≠ 0), both film characteristics being closely interconnected since they are simultaneously induced by the same sample growth process. Their specific morphology and microstructure configurations respectively engender different material behaviors under a particular physical field (E) effect. Any related film’s property (p) always results from their combined contributions. The study of p evolution is commonly investigated through its dependence on d, as mainly encountered for macroscopic scale thick samples (d ≥ 1µm), which is acceptable only when the condition (d/ σ ) ≥ 102 is fully validated. Achieving that condition is not at all systematic for real mesoscopic scale thick samples (d < 1µm) whilst the material property is clearly manifested. The study of p evolution as indicated above becomes widely problematic in that case. We here propose an original approach of dealing with the last situation for which d and σ are both taken into account. The method is applied to each specimen of a thin film’s series. An adapted common sample characteristic is thereby established that serves as a consistent variable of the film property. Illustration of that approach is provided by the study of nanostructured nickel electrodeposits for which coercivity (Hc) and magnetic domain size properties (w) are precisely investigated.

  • China Institute of Atomic Energy , China
  • Title:Physical Investigations of Solid Particles in Medical Injections by Nuclear Track Membranes
  • Time :

Abstract:

Solid particles contained in medical injections are harmful to human health if they enter the blood vessel through transfusion. Great number of glass shards and rubber fragments are two components of solid particles extremely easy to fall in liquid medicine. They are produced respectively by breaking ampoules and puncturing rubber plugs with needles.
In order to collect and remove the glass shards and rubber fragments, two types of cascade nuclear track filters have been designed and constructed. Simulated liquid medicines are prepared. Mimic transfusion process are carried out. The behaviors of the particles through the cascade track filters are investigated by using a scanning electron microscope (SEM) and Coulter instruments.
The two types of cascade nuclear track filters are: (1) PP+PET cascade track filter made of polypropylene (PP) fiber membrane as preliminary filter and polyethylene terephthalate (PET) nuclear track membrane as terminal filter; (2) Nylon+PET cascade track filter made of Nylon tortuous-pore membrane as preliminary filter and PET nuclear track membrane as terminal filter.
The shapes, structures, sizes and localities of the particles intercepted by the cascade filters are investigated by the scanning electron microscope (SEM), from which the rules of transport of the particles in transfusion are derived. The Coulter instruments are aimed at counting the solid particles before and after filtration in liquid medicine, from which the removal efficiencies of the cascade filters for solid particles are obtained. The flow rates of liquid medicine through the cascade filters are defined as the ratios of the volume of the passed liquid medicine to the time of filtration. The filtration was carried out at a pressure of 1 m high water column. The filtration time was 10 minutes.
The following results have been obtained in the investigations:
(1) Different types of solid particles can be identified with a scanning electron microscope (SEM). The glass shard has regular edges, sharp tips and smooth surfaces. The rubber fragment has wavy edges, blunt or round tips and uneven surfaces.
(2) Glass shards and rubber fragments may block and damage blood capillaries and cause lifelong injury.
(3) The structure of PP fiber membrane is very loose. The gaps between the neighboring fibers possess considerable discrepancies from very big to somewhat small. Very big solid particles are possible to penetrate through the big gaps and remain in the liquid medicine. Therefore, single PP membrane is insufficient to remove the big particles.
(4) The structure of Nylon tortuous-pore membrane is different from PP membrane; but the gaps between neighboring structures are also dispersed in size. Single Nylon membrane is also not suitable as filter to remove big particles from liquid medicine.
(5) Fortunately, it has been known before and shown in this work that PET nuclear track membrane has straight track pores, regular pore shape, unitary pore size and smooth flat surface. It can collect or remove all the solid particles larger than its pore size. The cascade nuclear track filters by using PET track membrane as terminal filter is a unique design for collecting and removing solid particles from liquid medicine.
(6) Specific functions of the preliminary PP and Nylon filters have been proved to be true and necessary that the preliminary filters can help to increase the removal efficiencies and to raise the flow rate of the cascade filters. The former effect is due to the removing of a part of big and small solid particles by the preliminary filters; the latter effect is due to the reduction of blocking the track pores by solid particles.
(7) The removal efficiencies and flow rates of the cascade track filters are all high enough to fulfill the requirements of medical services in China. Both types of the cascade track filters have been accepted by Chinese hospitals due to their high performances. The removal of solid particles from liquid medicine by nuclear track membranes will be helpful to strengthen the health of mankind in the world.

Biography:

Shi-Lun Guo is a professor in China Institute of Atomic Energy (CIAE) in Beijing. He joined in his Institute in 1961. He started to study Solid State Nuclear track Detectors (SSNTD) in 1965. He established the first laboratory in China on Fission Track Dating (FTD). He got the first radioactive age of Peking Man at Zhoukoudian in China by fission track method. This age was waited for 50 years by archaeologists. He got the first age of ancient man in Baise, China by fission track dating. This datum breached the theory on human evolution proposed 50 year ago. He started to study nuclear track membranes (NTM) in 1984. He helped to establish the first firm in China to produce filtration devices with nuclear track membranes for medical uses. This firm is the biggest firm in China for applications of nuclear track membrane.
Shi-Lun Guo worked in University of California at Berkeley, USA in 1982 to 1984, and worked in University of Marburg, West Germany in 1984, 1985, 1988 and 1990. He visited Waseda University in Tokyo, Japan many times to carry out bilateral collaboration.
Shi-Lun Guo is the winner of two awards from China National Science Congress and 4 awards from the Ministry of China National Nuclear Industry, from the Chinese Science Committee of National Defence, and from the Chinese People’s Liberation Army
Shi-Lun Guo was the President of the International Nuclear Track Society and an Honorary member of the International Nuclear Track Society. He served as an Editorial Board member of the International journal Radiation Measurements from 1981 to 2018, and served in the Editorial Board of the Japanese journal: Journal of Radiation Research. He also was the Editorial Board Members in two Chinese journals.

  • North China Electric Power University, China
  • Title:Dropwise Condensation and Droplet Dynamics on Nanostructure Surface
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Abstract:

Superhydrophobic nanostructures behaves lotus effect to promote droplet detachment. Thus, it was once regarded as the promising surface to enhance condensation heat transfer. To reveal the condensation heat transfer mechanism on nanostructure surface, three aspects of research were performed: the condensation experiment for long-term operation, the theoretical selection criterion of droplet detachment modes and the heat transfer model for dropwise condensation. The experiment identified two heat transfer regimes on fresh nanograss surface: higher heat transfer coefficients with droplet jumping, and constant heat transfer coefficients with droplet rolling. Compared with smooth hydrophobic surface, the nanograss surface has smaller droplet departure size but lower heat transfer coefficients. During one-week operation, condensate droplet detachment modes change from jumping or rolling to sliding, inducing the breakage of nanograsses. As result, the condensation heat transfer coefficients decrease. There detachment modes including jumping, rolling and sliding were observed for dropwise condensation on nonograss surface. The real detachment mode is the mode with minimum value of drop detachment radius. The detachment drop radii in jumping, rolling and sliding modes can be obtained from dimensionless criterion equations by energy, torque and force balance analysis, respectively. Specially, Prof. David Quéré proposed the problem of mode selection between rolling and sliding twenty years ago. Here, we answer this problem theoretically. It is interesting to find that switching criterion between rolling and sliding is only dependent on equilibrium contact angle  e: for  e<126.3°, a droplet only slides; for  e>147.0°, a droplet only rolls. Thus, the 147.0 is also recommended as contact angle boundary between hydrophobicity and superhydrophobicity. A theoretical model is proposed based on switching criterion of droplet detachment modes. Compared with classical model, the other improvements included linking surface wettability with micro-structure parameters, considering nano-porous thermal resistance under condensate droplets, etc. The model predictions match the measured heat transfer data well. It is concluded that nanostructure introduces both positive and negative effects to dropwise condensation. The increased nucleation sites number and decreased droplet detachment size
contribute positively, while the additional nano-porous thermal resistance behaves negatively. Broken nanostructures induced by long-term operation enlarge nano-pillars spacing, which weakens the positive effects and strengthens the negative contributions to yield heat transfer deterioration. To solve the problems on homogeneous nanostructure surface, the biphilic surface with hydrophilic dots among superhydrophobic nanostructures is recommended as the next generation of functional surface for condensation.

Biography:

Dr. Jian Xie is the specially hired researcher from school of Wu zhonghua and School of Energy Power and Mechanical in North China Electric Power University. He is the winner of Wu Zhonghua Scholarship and Chen Xuejun outstanding paper award. His research interest focuses on droplet dynamics and phase change heat transfer on functional materials with micro/nano structures. His contributions include: proposing theoretical mode selection criterion between droplet sliding and rolling; linking shock wave with microstructure parameters during droplet impacting porous membrane; improving dropwise condensation heat transfer model on nanostructure surface; obtaining controllable dropwise condensation and self-organizing droplet arrays on heterogeneous surface, etc. In the past few years, Dr. Jian Xie has undertaken or participated several foundations from National Natural Science Foundation of China and Ministry of Science and Technology. In recent years, he published over 40 SCI papers and served as guest editor for some SCI journals. Dr. Jian Xie has been invited to give keynote pretentions for 2019 ASME International Conference of Micro/Nanoscale Heat and Mass Transfer, 2018 International Conference on Nanomaterials & Nanotechnology and 2017 International Symposium of Fluids and Thermal Engineering. He is also invited to perform the IAAM Award Lecture for the coming 31st American Advanced Materials Congress.

  • University of Ferhat Abbas Sétif 1, Algeria
  • Title:ZnO/Carbon Nanowalls Ahell/Core Nanostructures as Electrode for Supercapacitors
  • Time :

Abstract:

Carbon nanowalls (CNW) were coated with zinc oxide (ZnO) for use as supercapacitor electrodes. The ZnO layers of different thicknesses were deposited using pulsed laser ablation in oxygen reactive atmosphere.
The performance of the CNW-ZnO electrodes such as specific capacitance and capacity retention, depends on the ZnO thickness which in turn influences of the CNW-ZnO electrodes. The areal capacitance of the CNW-ZnO measured in mild electrolyte of 1M KCl was as high as 4.3 mF.cm−2 at a current density of 0.2 mA.cm−2 and 1.41 mF.cm−2 at a scan rate of 10 mV.s−1 with an enhanced capacitance stability over 26,000 cycles. Such results demonstrate the potential use of ZnO nanostructures for low cost and high performance material for electrochemical capacitors.

Biography:

Since joining the University of Ferhat Abbas Sétif 1 and the University of Lille, GUERRA has been involved with studies related to supercapacitors for energy storage.