Duplex Technology Research Articles

LTE Network Area Coverage on FDD and TDD Technology

FDD (Frequency Division Duplexing) and TDD (Time Division Duplexing) Technology I is a duplex technology on the 4G LTE network. FDD technology in Indonesia is deployed in the 900 MHz, 1800 MHz and 2100 MHz frequency bands. Meanwhile, TDD technology uses frequency of 2300 MHz. In order to see the performance from the side of coverage, a measurement of the signal strength is conducted by direct measurements in field so that the appropriate technology and frequency band can be determined for the measurement area. The measurements have been done by two samples of different frequencies, namely 1800 MHz for FDD and 2300 MHz for TDD. Measurement of coverage is conducted on the same existing BTS and different BTS for both FDD and TDD modes. The parameter used in this measurement is the RSRQ value as one of the basic parameters of KPI (Key Performance Indicator). The results of drivetest data obtained the farthest coverage area of 789 m, namely the FDD (Frequency Division Duplexing) technology with frequency of 1800 MHz and TDD with frequency of 2300 MHz for 633 m.

In-Band Full Duplex Wireless LANs: Medium Access Control Protocols, Design Issues and Their Challenges

In-band full duplex wireless medium access control (MAC) protocol is essential in order to enable higher layers of the protocol stack to exploit the maximum benefits from physical layer full duplex technology. Unlike half duplex wireless local area network, a full duplex MAC protocol has to deal with several unique issues and challenges that arise because of the dynamic nature of the wireless environment. In this paper, we have discussed several existing full duplex MAC protocols and have shown qualitative comparisons among these full duplex MAC protocols. Full duplex in-band wireless communication has the potential to double the capacity of wireless network. Inter-client Interference (ICI) is a hindrance in achieving double spectral efficiency of the in-band full-duplex wireless medium. In this paper, we have classified existing solutions to the ICI problem and compared the solutions with respect to the proposed approaches, their advantages and disadvantages.We have also identified and discussed several issues and challenges of designing a full duplex MAC protocol. Results of qualitative comparisons of various wireless full duplex MAC protocols may be applied to design new protocols as well as researchers may find the identified issues and challenges helpful to solve various problems of a full duplex MAC protocol.

Application of Duplex Technology for Modification of Friction Pair Surfaces

The set of studies on modified superficial layer friction pair parts made of X155CrVMo12-1steel was discussed. The said layer is produced according to the duplex process of nitriding and oxidation and is investigated using methods of metallography, X-ray diffraction analysis and micro-hardness measurement based on the oblique and transverse polished sections of the studied surfaces. The results produced proved the duplex process efficiency.

A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead

Physical layer security which safeguards data confidentiality based on the information-theoretic approaches has received significant research interest recently. The key idea behind physical layer security is to utilize the intrinsic randomness of the transmission channel to guarantee the security in physical layer. The evolution towards 5G wireless communications poses new challenges for physical layer security research. This paper provides a latest survey of the physical layer security research on various promising 5G technologies, including physical layer security coding, massive multiple-input multiple-output, millimeter wave communications, heterogeneous networks, non-orthogonal multiple access, full duplex technology, etc. Technical challenges which remain unresolved at the time of writing are summarized and the future trends of physical layer security in 5G and beyond are discussed.

Energy Saving in Construction by Wide Application of High-Quality Insulation Based on Basalt Fibers

The influence of modern heat insulation materials on the ecological compatibility and fire resistance of residential and public buildings is considered. The nomenclature of fibrous heat insulation materials from basic rocks of volcanic origin is described. For basalt super thin fibers (BSTF), the production technology is described. The factors negatively influencing the engineering-and-economical performance of the duplex technology of production of the BSTF are analyzed. The engineering-and-economical performance of innovative enterprises for the production of basalt heat insulation and measures for its use in construction are given.

Experimental Research of Pyro Treatment of Canvases Made of Super Thin Basalt Fiber

Основной целью выполненного экспериментального исследования процесса пирообработки образцов холстов из супертонкого базальтового волокна, полученных на действующей промышленной установке, реализующей дуплексную технологию их производства, является подтверждение эффекта уменьшения пылевыделения при работе с такими холстами и формирование рекомендаций для назначения параметров процесса пирообработки. Актуальна проблема по максимальному уменьшению выделения пыли от материалов, используемых в производствах. Мелкодисперсная пыль, содержащаяся в холстах из базальтового волокна, вредна для кожи, слизистой оболочки и в особенности для легких человека. Даже при условии, что содержание пыли в производственном помещении находится в пределах норм, установленных техническими требованиями, аккумулируемое за годы работы воздействие на дыхательные пути имеет пагубные последствия для организма человека. Перед началом исследований процесса пирообработки была поставлена задача - предложить методику количественной оценки содержания в холстах из супертонкого базальтового волокна пылевидных включений. Такие включения могут загрязнять окружающее пространство производственного помещения при работе с холстами, при их ручной транспортировке, складировании, ручной упаковке или при изготовлении из них изделий заданной геометрической формы. Очевидно также, что эффективность процесса пирообработки холстов из базальтового волокна будет существенным образом зависеть от параметров теплового поля, создаваемого источником пламени. Поэтому следующая задача состояла в изучении распределения в пространстве высокотемпературного поля пламени горелки. На основном этапе исследований пламенем обрабатывались образцы холстов из супертонкого базальтового волокна при различной длительности воздействия, и проводился сравнительный анализ с необработанными образцами. Результаты свидетельствуют о влиянии обработки холстов пламенем на уменьшение количества мелкодисперсной пыли, выходящей из образцов в воздух при тряске и других видах механического воздействия.

Concepts of the physical level of the fifth generation communications systems

The most promising technologies of signal forming and multiple access have been considered from the viewpoint of bandwidth-time resource usage. They include the full duplex technology, subcarrier forming method using a comb filter bank, the non-orthogonal multiple access method, and the sparse code multiple access method. The main existing implementation schemes of full duplex communication based on the analog and digital proper transmitter in the reception channel are described. The filtering multifrequency signal system using a bank of comb filters is considered. The spectrum of such signal is shown to have a much weaker out-of-band radiation as compared to the existing subcarrier forming techniques. The non-orthogonal multiple access method and the sparse code multiple access method are investigated, and relationships of the bit error rates as a function of the signal-to-noise ratio for communications systems based on these methods are presented. It has been shown that the multiple access methods under consideration are more effective in the bandwidth-time resource usage as compared to the existing technologies.

The Analyse of Nanocomposite Thin Coatings Using Specimens Prepared by Focused Ion Beam Milling

The microstructure of physical vapour deposition (PVD) coatings deposited by duplex technology was investigated by Dual Beam FIB/SEM system (focused ion beam / scanning electron microscope), which allows one to examine cross sections of specimens from their surface down to the substrate. Examined were PVD coatings of nanocomposite type: duplex AlXN3 (X=Cr) and duplex nACRo3, deposited by LARC and CERC technologies. Duplex coating is a modern technology, which combines plasma nitriding and PVD coating in one cycle. The FIB analysis can be widely used in the field of study of basic materials and technological applications as it is based on highly focused ion beam which enables accurate machining of the investigated specimens and flexible processing at a micro/nanometric level. Cross sections of specimens obtained by FIB-SEMs document the arrangement of individual deposited nanomultilayers within the nanocomposite coatings and their EDS analysis in specific locations.

Micro-Abrasive Wear Testing of Surface Engineered Surgical Grade CoCrMo Alloy for Biotribological Applications

Abstract Wear of metal-on-metal hip joints is a concern due to the toxicity and biological reaction of wear debris. Retrieved CoCrMo hip implants have shown that abrasive wear is the predominant failure mechanism in such joints. There have been some efforts to improve the wear resistance of joint implants through the application of hard biocompatible ceramic coatings. However, the adhesion of the coatings has been a concern. The aim of the present work was to study the wear resistance of surface engineered CoCrMo alloy intended for biotribological applications by means of an abrasive wear test, based on the ball-crater technique. Different surface conditions were obtained on surgical grade wrought CoCrMo alloy: plasma nitrided, physical vapor deposition (PVD) coated (monolayer CrN and multilayer (TiN/CrN)×3) and modified using duplex surface engineering technology (a combination of the two previous approaches: plasma nitriding followed by plasma assisted PVD). The engineered surfaces were characterized by scanning electron microscopy, nanoindentation and, atomic force microscopy (AFM). Scratch test was used to determine the influence of the duplex technology on the adhesion of the coatings to substrate. The wear resistance of the different surface conditions was determined using a slurry abrasive micro-abrasion testing device. It was found that the duplex engineering technology enables a significant rise in the resistance of surfaces against concentrated loading modes, improving the adhesion of the coatings to the substrate; however, it has no significant influence improving the wear resistance of the samples during the abrasive wear tests.

Combined surface heat treatment: state-of-the-art

Thermal electron beam (EB) technologies, thermochemical surface treatments, and numerous variants of physical and chemical vapour deposition (PVD or CVD) hard coatings are used to treat a wide spectrum of different tools and highly loaded components, and have, to some extent, become successful industrial applications. Specifically, each of these groups of surface technologies is used to enhance surface hardness and wear resistance. The application is restricted, however, by physical, technical and technological characteristics. Special loading conditions present a great challenge, as the load–bearing capacity of each of the surface layers produced is limited. The combination of EB surface treatment with thermochemical treatment and/or PVD or CVD hard coating enables significant further improvement of the relevant properties. This paper presents a survey about the history, the state of the art of development as well as fields of application for these innovative duplex or triplex surface technologies.

Improve of the ATDD in Cognitive Radio Wireless Network

The radio spectrum is limited, but in urban and rural areas some bands of radio spectrum are idle in most of the time. Some bands of radio spectrum are occupied occasionally. On the other hand, some bands are excessively used. This paper propsed an adaptive time division Duplex (ATDD) technology to effectively improve the transmission delay in the large range ,such as the rural network in 802.22 network.

Enhancing saltiness in emulsion based foods

Abstract Background The concept of enhancing saltiness perception in emulsions and a liquid food formulated with the emulsions (ambient vegetable soup) through increasing salt concentration in the continuous phase while retaining the fat content of the (aqueous continuous) product was evaluated. This was accomplished by increasing the droplet phase volume using duplex emulsion technology. Viscosity and droplet size distribution was measured. Saltiness evaluation was based on simple paired comparison testing (2-Alternate Forced Choice tests, BS ISO 5495:2007). Results Single and duplex emulsions and emulsion-based products had comparable mean oil droplet diameters (25 to 30 μm); however, viscosity of the duplex emulsion systems was considerably higher. Sensory assessment of saltiness of emulsion pairs (2AFC) indicated duplex technology enhanced saltiness perception compared to a single emulsion product at the same salt content (6.3 g/100 g) in both simple emulsions and the formulated food product (P = 0.0596 and 0.0004 respectively) although assessors noted the increased viscosity of the duplex systems. The formulated food product also contained pea starch particles which may have aided product mixing with saliva and thus accelerated tastant transport to the taste buds. Lowering salt content in the duplex systems (to levels of aqueous phase salt concentration similar to the level in the single systems) resulted in duplex systems being perceived as less salty than the single system. It appears that the higher viscosity of the duplex systems could not be “overruled” by enhanced mixing through increased droplet phase volume at lowered salt content. Conclusions The results showed that salt reduction may be possible despite the added technology of duplex systems increasing the overall measured viscosity of the product. The changes in viscosity behavior impact mouthfeel, which may be exploitable in addition to the contribution towards salt reduction. With a view to applying this technology to real processed foods, it needs to be tested for the product in question but it should be considered as part of a salt reduction tool box.

Tribological investigation of low friction duplex surface treatment based on modified molybdenum disulphide coating

One of the numerous possibilities to decrease friction and wear of sliding surfaces consists of the application of two-step (so called duplex) technologies. A novel duplex technology of gas sulphonitriding of a 41CrAlMo7 steel with subsequent deposition of a low friction MoS2(Ti,W) coating by means of non-reactive magnetron deposition is described in the present paper. A pin and vee block geometry and a relevant Falex apparatus were chosen for implementation of a linear friction contact under heavy loadings. For comparison, five other treatments of machine parts applied in the industry were used in the paper as well. As a result of the tests, only the specimens after the proposed novel duplex treatment based on sulphonitriding and a low friction MoS2(Ti,W) coating deposition outlasted the full load of 3500 N during 6 min without any failure from all the six different treatments investigated in the work.

Electron meets nitrogen: combination of electron beam hardening and nitriding

AbstractCombined heat treatments, also known as duplex or hybrid technologies, offer new structure/property relationships in layered matrix compounds. The treatment sequence is critical. There are within reach both properties and property gradients that are impossible to achieve using the respective single treatment processes alone nor by simple addition of the effects of the single processes. Good technical progress is given by the combination of thermochemical treatment with high energy beam surface hardening, in particular electron beam hardening. After a historical survey (milestones) of the combination of thermochemical with thermal (surface) heat treatment technologies, the paper deals with the principles of the combining electron beam hardening after nitriding and vice versa , electron beam hardening before nitriding and the effects on microstructure and properties. Typical examples of industrial application are discussed. In this field of heat treatment, further development is focused on combinati...

Safety and Efficacy of the Sonographic Acceleration of the Middle Cerebral Artery Recanalization: Results of the pilot Thrombotripsy Study

The aim was to demonstrate the safety and efficacy of continuous ultrasound monitoring of the artery occlusion area (sonothrombotripsy) in patients with acute middle cerebral artery (MCA) occlusion. A total of 52 consecutive patients with acute MCA occlusion were included in the thrombotripsy group. Doppler monitoring of the region of occlusion was performed for up to 45 min. The control group was created from the NAIS study database. Patients were matched for their vascular status, age, sex, artery occlusion, NIHSS at admission, rt-PA treatment and time to the first ultrasound examination. The number of recanalized arteries at 6 and 24 h after the onset of symptoms, the number of independent patients (mRS 0-2 versus 3-6) after 90 d, and the number of serious adverse events were statistically evaluated. In the thrombotripsy group, 19 patients (36.5%) had complete recanalization and 27 (51.9%) patients had partial recanalization at 1 h after the start of the TCCS monitoring. Higher recanalization rates at 6 and 24 h after stoke onset were also seen compared with controls (69.2% versus 7.7% and 92.3% versus 61.5% complete recanalizations, respectively, p < 0.05). Independence (mRS 0-2) at day 90 was achieved by 61.5% of the thrombotripsy patients and 32.7% controls, p < 0.05, odds ratio 1.88 (95% confidence interval = 1.23 – 2.90). In both groups, two symptomatic intracerebral hemorrhages and one symptomatic brain edema occurred. Sonothrombotripsy with diagnostic transcranial duplex technology is safe and may offer benefit in addition to standard of care stroke treatment. E-mail: ( skoloudik@hotmail.com)

Ambient OPC conditioning effect outside and heat-induced interaction between the OPC and fuser belt inside the Oc&amp;#xE9; VP6000 printer

The Oc&#xE9; Gemini Instant Duplex technology forms the heart of the Oc&#xE9; VarioPrint 6160/6200/6250 printer line. Since duplex productivity is key, the main technological issues that have been solved during development were architectural and robustness related. Robustness, in our philosophy, not only means large lifetimes of parts and consumables, but also a robust, constant and consistent performance and print quality of both print processes for various media and environments. To realize the necessary print quality robustness, we have made various innovations in the OPC, LED-printhead, transfer efficiency, transfuse robustness and process control.In this contribution we will first describe the essentials of the printing process of the Oc&#xE9; VarioPrint 6160/6200/6250 printer line. After that, we elaborate a little further on the influence of ambient humidity conditions on the OPC-belt and its production process. Finally, the transfer-transfuse process and the heat interaction with the OPC-belt is discussed. These items represent two related print quality problems that had to be solved in order to realize a productive duplex print engine on an integral level.

Traceability of extensively produced Iberian pigs using visual and electronic identification devices from farm to slaughter1

A total of 351 Iberian pigs with equal numbers of both sexes from 2 commercial farms were used to study the ability of various identification devices to guarantee the traceability required for labeled meat products from Iberian pigs reared under extensive production conditions in Spain. The performance of tattoos, visual ear tags, electronic ear tags, and i.p.-injected transponders of half duplex and full duplex technologies were compared during a production cycle from nursery to slaughter at 15 mo of age (156 +/- 3 kg of BW). No major health reactions to any of the identification methods were detected. Results showed that tattooing was not an adequate identification procedure due to reading difficulties as a consequence of dark skin, soiled appearance, and figure deformation. Ear tag losses and failures were affected by fencing type and increased in one of the farms (20.4 and 15.7% for losses and failures, respectively; P < 0.05) as a consequence of using barbed-wire fences. Ear tag losses decreased when fences changed to stone blocks at 365 d of age. Visual and electronic ear tag losses during transport and slaughter were low (3.7% for visual and 3.1% for electronic tag). Results of injectable transponders during the growing-fattening period were variable and were more readable for the half duplex than for the full duplex i.p. transponders (92.0 vs. 68.7% +/- 1.5; P < 0.05). Handheld transceivers worked properly under extensive conditions, although the body size and skin characteristics of the Iberian breed might limit the performance of reading devices, and the use of transceivers with longer reading distances is recommended. The main problem observed with i.p. transponders was their low recovery rate at slaughter due to the lack of adherence of the transponders to the omentum.

Plasma-ion beam source enhanced deposition system

An advanced deposition system, plasma-ion beam source enhanced deposition system, is introduced. This equipment is composed of metal ion implantation source, gas ion implantation source, magnetron sputtering source, planar plasma source, hot filament plasma source and magnetic filtered cathode arc source. The metal implantation source and the gas implantation source are working with cathode arc and magnetron sputtering simultaneously. Many kinds of duplex technologies of plasma enhanced deposition can be realized in this system. The characteristics of plasma sources are described. Some duplex hard coatings are prepared, such as metal-doped diamond-like carbon (DLC) films, nitriding-TiN films and hard coatings on bearing steel at low temperature. The performances of these films were studied. The results show that the processes can be widely used in industry.

Sclerotherapy of spider veins

Sclerotherapy of spider veins Victoria Vitale-Lewis; Boston; 1995; Butterworth-Heinemann; 142 pages; $125. This brief textbook serves as an excellent primer for those physicians interested in the management of spider veins. Dr. Vitale-Lewis reviews the anatomy and physiology of spider veins as well as the venous system and goes through a thorough review of patient selection, examination, and testing. The description of injection technique is as precise as one can be in a field where most of us develop our own technical concepts. The results and complications omit none of the major problems in the management of this vexing patient complaint. The discussion of results rightfully emphasizes the great importance of patient satisfaction with the procedure. Although as many as 80% of patients are symptomatic, in the end, the patients' evaluation of results has a profound effect on their desire to continue in the treatment protocol. It is patient satisfaction with the procedure more than anything else that results in their continuing in a treatment program. The author fairly reviews both sides of the compression controversy, but stops short of recommending a long-term compression program, which we have found indispensable in decreasing recurrence. The effect of climate on a decision to use compression therapy is touched on and is a critical part of the argument of whether we can get a patient to use long-term support stockings. Not enough emphasis is placed on the need for a custom-fitted pressure gradient support stocking to control long-term recurrence. A minor point of issue is the initial use of a cotton ball at the injection site to provide additional pressure. We have pointed out in previous publications the importance of compressing not the needle entry point, but the entire length of vein that has been filled with sclerosing agent, thus necessitating a more comprehensive type of gauze pad. The major problem with the book is in the area of preoperative noninvasive testing. The Doppler examination is well-illustrated and adequately described, but the usefulness of bidirectional Doppler is not considered. The handheld Doppler scan can be expected to identify some sites of incompetence, but probably not all. Neither can it identify anatomic variations, duplicate veins, or enlarged tributary veins that may overlie smaller underdeveloped named veins. The author chooses to dismiss duplex technology as bulky, cumbersome, and expensive, but it is difficult to argue with its ability to measure, localize, and classify a wide range of conditions. Duplex technology in patients who have exclusively spider veins has shown us a surprising range of large reflux points that would not have been detected and quantified without the duplex scan. The frequency and wide range of venous anomalies remain an unending surprise that can only be guessed at by other techniques. Consequently, we use duplex scanning routinely in this group of patients. On the whole, this is an excellent textbook, well-illustrated and comprehensive in its bibliography, and a must-read for those physicians who are interested in sclerotherapy.

Ultrasound Assessment of Mesenteric and Renal Ischemia

Diagnostic ultrasonography has shown an incredible rate of development during the past 2 decades. This advance has most recently been marked by the introduction of duplex technology and Doppler color flow imaging. The full impact of these new technologies may not be realized until their clinical usefulness has been defined. With application of duplex scanning and Doppler color flow imaging to evaluation of the visceral vasculature, the user quickly becomes aware of the capabilities and limitations of these modalities. An understanding of the basics of duplex and color flow technology and the complexity of visceral hemodynamics is essential to achieve accurate ultrasound evaluations of these circulatory systems.