A Software Model for Parameters Affecting the Dimensions of Reinforced Concrete Prefabricated Facade Elements

In this study, a model software of a computer program related to determining dimensional behavior, which will contribute to the multi-layered units used on the facade of industrial buildings to be standardized, has been prepared. By means of this model software, the factors determining the width (A), the height (h) and the section (d) of the units of a building facade, could be evaluated. These factors, at the same time, from the dimensions of building facade units providing “thermal insulation, sound insulation statically behavior and coordination dimension of facade unit.” In the program (named as MT2 Prefabrike), these four factors could be evaluated by providing the optimization in sequence and within themselves. Thus, by developing a new method of approach in the standardizing of facade units, apart from the visible characteristics of the units, the idea of standardizing the performance and behavior expected from the units, are put forward. In the model program formed with this idea, before producing of the facade units, the optimization is to be provided by analyzing the factors which are effective in giving dimension to the units, in abstract condition (computerized). Keywords: a model software, building facade unit, prefabrication, thermal and sound ınsulation, static behavior analysis, the facades of ındustrial buildings

A Waste Energy Recovery Management for Electricity Generation from Two Temperature Grades of Energy Sources in Subcritical Organic Rankine Systems

Waste energy represents one of the most critical issues for the economic utilization and management of energy in modern industrial fields. This article outlines a scheme to utilize two different source temperature levels within the envelope of higher than 200 °C zones. Two regenerative organic Rankine cycles (RORC) were implemented to construct a compound regenerative organic Rankine cycle (CRORC) to improve the energy management of the sources. These two mini-cycles were integrated throughout an intermediate economizer circuit to extract a certain amount of energy from the high-temperature level mini-cycle. R-123 was circulated in the high-temperature cycle due to its high critical temperature at evaporation and condensation temperatures of 160 °C and 50 °C, respectively. R-123, R-21, and hydrocarbon R-600 were used as working fluids for the low-temperature cycle at evaporation and condensation temperatures of 130 °C and 35 °C, respectively. The R-123 fluid in the high-temperature mini-cycle was superheated to 170-240 °C, whereas the fluid in the low-temperature level was superheated to 180 °C. The results showed that the independent system (IRORC) requires more energy recovery than the compound system by a maximum of 2% to achieve the same net power output. This corresponds to the enhancement of 2% for the system net thermal efficiency of the compound (CRORC) system compared to the independent (IRORC) one. The compound (CRORC) system revealed a net thermal efficiency in the range of 14% and 15.6% for the test conditions. The mini-cycle net thermal efficiency of the low-temperature in the compound system was enhanced by a range of 2.5-5% compared to that of the independent arrangement. R-123/R-123 and R-123/R-21 systems exhibited higher net thermal efficiencies than the R-123/R-600 one by 3% and 2%, respectively. Increasing the superheat degree of the high-temperature mini-cycle from 10 °C to 80 °C for the compound system has improved the thermal efficiency by 7.6-7.9% for the examined fluid pairs and operating conditions. Keywords: compound cycle, regenerative, energy management, energy recovery, organic fluids

E-Banking and Monetary Policy in Nigeria

The goal of this paper is to assess the impact of e-banking, which are distinct from conventional banking systems, on central banks’ monetary policy. E-banking poses a challenge to central banks’ ability to control interest rates and it may also increase endogenous financial instability. The challenge to interest rate control stems from the possibility that e-banking may diminish the financial system’s demand for central bank liability, rendering central banks unable to conduct meaningful open market operations. Increased financial instability could emerge from the increased elasticity of private money production and from the periodic runs out of e-banking into central bank money that generates liquidity crises. Similarly, the future of e-banking is dependent on its growth, regulation and increased technological advancements that would boost the security of the new instrument. It will directly impact the central bank’s control of monetary policy unless it is included in its measurements of monetary aggregates. We therefore recommend that since the impact of e-banking on monetary policy depends solely on how fast it will spread and the extent to which it will substitute for cash, it is vital that Central Bank of Nigeria (CBN) considers taking steps to compensate the resulting decrease in its balance sheet. Also, CBN must have to impose special obligations with the money reserve on the e-banking issuer in case of any large increase in e-banking creativity that will affect the monetary policy at the end. The government must keep the rate of prices stable and with this condition, where e-banking will be equal to other forms of money which maintain by apportion percentage as a reserve ratio to the central bank. Similarly, if e-banking spreads moderately, there will be a decrease in the seigniorage income and thus, the decrease in the balance sheet of CBN will be limited. Hence, it must include e-banking in monetary aggregates that the spread of e-banking may lead to a change in the velocity of money. Keywords: monetary policy, e-banking, technology, velocity of money

Assessment of Miniature Piezoelectric Travelling-Wave Beam and Plate Robots

Different up-to-date utilizations have found several benefits in condensing the size of autonomous robots. Miniature traveling wave piezoelectric robots have proven to be appropriate for many of these applications. The principles of locomotion embraced in these robots are mainly inspired by natural biological locomotion and could be categorized by their movement through a specific medium. In this article, after having highlighted the amplifying effect of piezoelectric actuators generating the locomotion necessary for robotic requests, we will review the different types of such locomotion. Next, we will discuss the traveling wave piezoelectric resonant robots. Succeeding, we will look at the operation and usages of piezoelectric beam and plate robots. Finally, we will discuss the modeling aspects implicated in these robots and more generally, the modeling of piezoelectric patches stuck on thin structures. Keywords: piezoelectric, miniature, travelling-wave, locomotion, beam and plate robots

Liquefaction Potential Analysis in Bucharest City as a Result of the Ground Shaking during Strong Vrancea Earthquakes

Bucharest, the capital of Romania with about 2.5 million inhabitants, is frequently struck by intense, damaging earthquakes (2–3 events per century). The Collaborative Research Center 461 (CRC-461) entitled: “Strong Earthquakes - a Challenge of Geosciences and Civil Engineering” was established in July 1996 and ended in December 2007, but some projects continued until 2010. It was funded by the German Research Foundation and involved the University of Karlsruhe which today belongs to Karslruhe Institute of Technology. The CRC aimed strategic research in the field of strong earthquakes with regional focus on the Vrancea seismic events in Romania. Between 1995–2007 several research works were done in Romania, with the support of several Romanian research institutes and the University of Bucharest. One of the research questions was to study the occurring of liquefaction during strong earthquakes within the shallow sandy layers in Bucharest. In suitable conditions, strong earthquakes can cause, under certain geologic conditions, liquefaction and therewith ground failure as sand boils, lateral spreading, or differentiated subsidence. In the present paper we analyze the liquefaction risk for Bucharest. For this purpose, at 10 representative sites in Bucharest, Seismic Cone Penetration Tests (SCPTu) were executed. An area-wide evaluation of the liquefaction probability in Bucharest was established. The factor of safety (FS) against liquefaction and the probability of liquefaction (PL) were computed from the obtained test-data. For the first time, maps of the liquefaction potential index (Li) for Bucharest were outlined. This map shows how severe the liquefaction phenomena might be during strong Vrancea earthquakes in Bucharest, amplifying the site effects. Keywords: hydrogeologic conditions, liquefaction probability, liquefaction hazard, Bucharest city, strong Vrancea earthquakes

ANumerical Uncertainty in Parallel Processing Using Computational Fluid Dynamics as Example

Computational methods such as Computational Fluid Dynamics (CFD) traditionally yield a single output – a single number that is much like the result one would get if one were to perform a theoretical hand calculation. However, this paper will show that computation methods have inherent uncertainty which can also be reported statistically. In numerical computation, because many factors affect the data collected, the data can be quoted in terms of standard deviations (error bars) along with a mean value to make data comparison meaningful. In cases where two data sets are obscured by uncertainty, the two data sets are said to be indistinguishable. A sample CFD problem pertaining to external aerodynamics is copied and ran on 29 identical computers in a university computer lab. The expectation is that all 29 runs should return exactly the same result; unfortunately, in a few cases the result turns out to be different. This is attributed to the parallelization scheme which partitions the mesh to run in parallel on multiple cores of the computer. The distribution of the computational load is hardware-driven depending on the available resource of each computer at the time. Things, such as load-balancing among multiple Central Processing Unit (CPU) cores using Message Passing Interface (MPI) are transparent to the user. Software algorithm such as METIS or JOSTLE is used to automatically divide up the load between different processors. As such, the user has no control over the outcome of the CFD calculation even when the same problem is computed. Because of this, numerical uncertainty arises from parallel (multicore) computing. One way to resolve this issue is to compute problems using a single core, without mesh repartitioning. However, as this paper demonstrates even this is not straight forward. Keywords: numerical uncertainty, parallelization, load-balancing, automotive aerodynamics

The D-Learning Alternative during COVID-19 Crisis: A Preliminary Evaluation based on Kirkpatrick’s Model

The COVID-19 pandemic has placed schools around the world under unprecedented challenges where saving students’ lives is placed ahead of education as a priority. Within these conditions of distress and uncertainty, education authorities had no choice but to move traditional classes into online ones to ensure the sustainability of studies. The abrupt inevitable decision has been a first for most if not all teachers and students who are invited to cope with a totally new teaching/learning model without necessarily having prior experience in Distance Learning in terms of apparatus or techniques. This study comes as an in-progress appraisal of the D-learning scenarios proposed by Moulay Ismail University (MIU) in Meknes, Morocco, based on a two-level evaluation model (Reaction and Learning) proposed by Daniel Kirkpatrick. It is a real-time evaluation of a learning strategy that has long been considered optional for some students, to become, rather, a plan A constituent for many education departments around the world. The study investigates areas of success and failure from the students’ perspective via 4 sub-indicators: accessibility, autonomy, retention and psychological impact. The study concludes that the figures can be more reassuring about the D-learning experience in MIU once issues related to connectivity and communication are redressed. Keywords: d-learning, e-learning, pandemic, COVID-19, Kirkpatrick’s model, information and communication technology

Design of a Four-Seat, General Aviation Electric Aircraft

Financial and environmental considerations continue to encourage aircraft manufacturers to consider alternate forms of aircraft propulsion. On the financial end, it is the continued rise in aviation fuel prices, as a result of an increasing demand for air travel, and the depletion of fossil fuel resources; on the environmental end, it is concerns related to air pollution and global warming. New aircraft designs are being proposed using electrical and hybrid propulsion systems, as a way of tackling both the financial and environmental challenges associated with the continued use of fossil fuels. While battery capabilities are evolving rapidly, the current state-of-the-art offers an energy density of ~ 250 Wh/kg. This is sufficient for small, general aviation electric airplanes, with a modest range no more than 200 km. This paper explores the possibility of a medium range (750 km) electric, four-seat, FAR-23 certifiable general aviation aircraft, assuming an energy density of 1500 Wh/kg, projected to be available in 2025. It presents the conceptual and preliminary design of such an aircraft, which includes weight and performance sizing, fuselage design, wing and high-lift system design, empennage design, landing gear design, weight and balance, stability and control analysis, drag polar estimation, environmental impact and final specifications. The results indicate that such an aircraft is indeed feasible, promising greener general aviation fleets around the world. Keywords: general aviation aircraft, electric aircraft, aircraft design

Agile-Stage-Gate Approach: Exploratory Research on the Structure, Roles, and Responsibilities

One of the most prominent methodologies gaining recognition in recent years is the Agile-Stage-Gate approach. The relatively new hybrid model is a combination of the Stage-Gate and the Agile-Scrum models. Several companies already using the Stage-Gate process have recently adopted the Agile-Stage-Gate approach to improve product development and project management. However, each of these companies has added their adjustments and modifications to the new approach in order to accommodate their specialized needs and to achieve the goals that are unique to their company. Therefore, no fixed structure or standardized features have been explicitly assigned to this hybrid approach. Instead, each company has added on different features and manipulated the new approach to fit whatever needs arise from moment to moment. This ambiguity leads to the question of whether the structure, roles, and responsibilities of this new approach can be defined and if so, how these clear and consistent definitions can improve productivity, efficiency, communication and market response time. The purpose of this study is to explore the structure, roles, and responsibilities within this new approach and to identify patterns that emerge during the product development and project management processes. The research questions presented were administered and examined through a qualitative survey. Fifty-two complete responses were collected from experienced individuals who have varying degrees of experience with the Agile-Stage-Gate approach. These findings revealed many similarities and differences between the structure, roles, and responsibilities of this approach, which were also dependent on the product and project type being considered. The most apparent similarities between roles and responsibilities were found in the case of software products and new product development projects. The Agile-Stage-Gate approach has also had a significant and undeniable impact on team communication and performance and was shown to improve overall quality and productivity. Keywords: agile, stage-gate, customer, scrum, sprint, hybrid, ideation, combination products, backlog, retrospective

What 5G has been and what should 5G+ be?

In this work we aim to provide a comprehensive summary of the most inspiring aspects of 5G mobile networks. In addition, we present the latest findings on the promising 6G technology towards a world of fully digital connectivity. The key determinants are extreme system performance and combinations of requirements for new use cases. We study new performance targets beyond 5G in two stages: 5G+ evolution and new 6G step. Relevant technologies considered too immature for 5G or outside the defined scope are outlined. To justify our vision of future mobile networks, we point out the need for closer collaborations of academia, standardizing bodies, industrial organizations and governments. The contribution strategy is gradual evolution and performance enhancement of mobile communications. Finally, we identify challenges and directions on network technology roadmap toward 6G. Keywords: wireless communication, mobile broadband, low-latency communi-cation, 5G network, 3GPP, 6G vision