Analele Universitatii

9-16

Authors: Olga-Ioana Amariei, Codruta-Oana Hamat, Daniel-Mihai Amariei

In this paper we propose a protocol for economic decision-making by the management of an industrial enterprise, which wishes to set up a new production unit. The problem is finding the location of the new production unit, which will minimize the total transport cost, consisting of an amount of costs directly proportional to the distances between the new and existing locations. In order to obtain the optimum location, the QSB software package was used, which uses, besides the Manhattan model and the Euclidean and Euclidean quadratic distance measurement model.

25-30

Authors: Marcel Burduniuc, Ion Stratan, Tudor Ambros

In the paper is done the calculation of the magnetic field of the threephase power transformer with three columns in extreme conditions. The calculation is performed with FEMM application based on finite element theory. The distribution of the magnetic flux from the transformer's magnetic core was obtained. It has been demonstrated the possibility of specifying of the winding and the magnetic system parameters of the transformer.

45-48

Authors: Kristijan Cincar

Ambient Assisted Living (AAL) systems help people to stay active and have a decent life with the help of continuous monitoring for healthcare. Sensors help us to monitor, but the activity of sensors to false positive or negative decay of these monitoring and the status of worships.This work we analyzed detection and tolerance for event triggering sensors in AAL systems.

53-58

Authors: Lenuta Cîndea, Vasile Iancu

The paper includes a comparative study on the efficiency of dimensional stabilization of welded stitches in P265GH steel pipes by local-stress relief heat-treatment and low frequency mechanical vibration. Considering the fields of use, these steels must provide high temperature resistance (creep) and ductility, especially elongation and cracking, at high, stable values during the use of the metal structure. Taking a decision on applying stress relieving treatment to a welded structure should take account of certain major factors. Also, depending on the level and distribution of the residual stresses, the volume of the weld structure and its complexity, it will be decided whether the stress will be done totally or locally. Also, one of the drawbacks of applying the method is that stress relieves the manufacturing time and cost of the welded structure. If for a thermally stressed part the duration is 24 hours or more in the case of mechanical vibration stabilization, the time shortens significantly.

67-75

Authors: Anthony Ede, Oluwarotimi Olofinnade, Solomon Oyebisi, Akpabot Akpabot, John Oluwafemi, Kehinde Oyeyemi

Selection of construction materials are normally based on their ability to support design loads all through the service life of the structure to be built. For a reinforced concrete structure, the prime choices fall on the quality of concrete and steel reinforcing bars. Concrete is a composite of cement matrix which fills the space between aggregates and binds them together. Concrete quality fluctuates considerably for various reasons such as immense variability of constituent materials’ properties,the skill of the producer, placement procedure and environmental issues. Concrete is universally accepted for its excellent compressive strength. Concrete’s poor tensile strength is normally combined with the high tensile strength of steel reinforcing bar, providing a reinforced concrete composite that is universally accepted for construction. Steel is manufactured in specialized plants and the properties are controlled and certified by the manufacturer. The designer is, therefore, more confident in specifying steel quality complying with a relevant standard, while the choice of concrete mixes is not easy. Nevertheless, concrete and steel complement each other, compensating the weaknesses in the properties of the two materials, thereby making it a universal accepted construction material that has built the world’s most buildings and infrastructure. But due to the frequent cases of the collapse of reinforced concrete buildings and infrastructure in Nigeria, a study of the properties of steel samples available in Nigeria is essential. The scope of this research is on factors that influence the ductility of reinforced concrete, i.e., the properties of steel rebar. This study considers the yield strength and the chemical properties of the three most common diameters of steel rebar used in Nigeria. The results show some deviations in mechanical characteristics and chemical properties of some of the samples. This confirms that some of the samples fell short of the BS codes’ benchmarks for steel rebar.

86-92

Authors: Gilbert-Rainer Gillich, Vasile Iancu, Nicoleta Gillich, David Lupu, Andrea Amalia Minda

Estimating the harmonic components of a signal is based on calculating the signal energy on certain spectral bins that position is defined by the signal time length. Because of this mode of calculation, a difference between the true frequency and the estimate is usually found. In this paper, we present an advanced frequency estimation method, which searches first for the time length for which an entire number of cycles is contained in the signal and afterward calculates the Discrete Fourier Transform (DFT). The results have been found significantly closer to the true frequency as those obtained by a standard DFT applied to the original signal, but it still depends on the number of cycles involved. To further improve the estimation results we propose a methodology to make a correction depending on the number of cycles and sampling frequency.

99-106

Authors: Sava Ianici, Draghiţa Ianici

Research on the harmonic transmissions has shown that their functional performances are mainly influenced by the kinematic and dynamic behavior of the flexible wheels in these transmissions. The paper presents a study of the particular aspects of kinematics within a double harmonic transmission. This study aims to present the mathematical algorithm for determining and constructing the trajectories of points located on the average fibers in the two front surfaces of the flexible wheel from a double harmonic transmission. In order to realize the graphical constructions of the trajectories of these points of the flexible wheel, an original calculation program was developed and run, written in the language Visual Basic.

119-124

Authors: Tatian-Cristian Mălin, Gilbert-Rainer Gillich, Dorian Nedelcu

The retrieval and storage of information from historical earthquake records are very important for the study of seismic activity and the prevention of the danger that earthquakes represent in areas with intense seismic activity. This is possible due to modern techniques and methods of processing, converting old data into digital data and storing them on online databases. This paper presents some important web-based database that provides tools for searching, selecting and downloading ground motion data.

133-138

Authors: Calin-Octavian Miclosina, Zoltan-Iosif Korka, Vasile Cojocaru

The paper presents the manner of determination of forces that act on a workpiece grasped by a pneumatically driven robotic gripper. The starting point consists of experimental determination of the pushing force necessary to move the workpiece held between the gripper's fingers. Then, by using theoretical relations, the friction force between the workpiece and the fingers, and the prehension force (also called gripping force) are computed, for different values of the pneumatic driving system pressure.

147-152

Authors: Ion-Cornel Mituletu, Deian-Dorel Ardeljan, Andrei-Viorel Aniţulesei

The paper describes the way of a system dimensioning required to achieve a linear displacement measurement. The system is based on a microcontroller and an incremental encoder. Taking into account the needing of electronic parameter adaptation at the interfacing of the incremental encoder and the microcontroller, a constructive-functional optimization is accomplished. The sensibility of displacement measurement is given by the number of pulses per angular unit, the microcontroller processing and counting speed as well as the efficiency of implemented algorithm and source code. At the dimensioning of electronic circuit is also requested to consider the possibility of perturbation inducing due to the electromagnetic interference of own sources or from environment.

161-168

Authors: Siti Nur Aqilah Amanina Mohd Kassim, Md Azree Othuman Mydin

In recent years, there has been a growth in the population and migration of people from rural areas to urban settings. This phenomenon serves as a contributing factor to the increase number of flyovers. Even though the growth of urban flyovers has optimized the urban transport system and improved the spatial structure of the city, the utilization of space under overpasses has many problems, and they can be dark, short, hostile, and abandoned spaces which are full of girders and include ill-shaped areas in some parts. A huge number of idle and forgotten spaces under the flyovers have been bred. Presently, dark and neglected, that is, the kind of derelict space that lurks below most highways and elevated roadways. Since the number of flyovers has been increasing nowadays, the idea of utilizing spaces under flyovers has become a moot point. The increase number of flyovers also resulted in many leftover spaces available under flyover. These unplanned spaces, if utilized properly, offer an abundance of opportunities. Hence, this study focuses on exploring possible construction and adaptive use of “grey space” under flyover. The case study will be in three main cities which is Penang, Kuala Lumpur and Johor Bahru. This research will be conducted through a combination of site observations, interview and questionnaire surveys. The main objective of this research is to propose three suitable designs for adaptive use of “grey space” under flyover that comply with rules and regulations. As for the conclusion, the size and the location of flyover will determine what can be developed. Hence, without performing any large construction, we will be able to utilize the leftover space under flyover.

181-190

Authors: Dorian Nedelcu, Gilbert-Rainer Gillich, Istvan Biro, Zoltan-Iosif Korka, Attila Gerocs

The objective of the paper is to calculate the velocities and accelerations for some points of the punching cards mechanism and to compare the results calculated through grapho-analytical method with the SolidWorks Motion results.

197-204

Authors: Marius Romocea

Given that the competition between the industrial companies is increasingly tough, the problem of setting up by them of the spare parts manufacturing programs with own resources has become of a great importance. Determining an optimal manufacturing program means setting up a program to ensure, with the material and human resources of the unit, an optimization criterion such as maximum profit, minimal expenses, minimum costs, etc. Next, we present the case where the "profit" optimization criterion is chosen using linear programming.

213-220

Authors: Vasile Solcanu, Marian Gaiceanu

The multitude of disturbing signals from the military operations theatres and battle platforms can lead to the nonlinear operation of radiofrequency (RF) modules in radio receivers with unfavorable effects on the processing of the useful signal. The authors propose in this paper a new way to compensate the operating effects of RF amplifiers in the nonlinear area by introducing a feedback loop based on signal decomposition in reverse power series.

231-238

Authors: Mihaela Dorica Stroia, Cornel Hațiegan

In the present paper we present 3D models of three types of components, parts of power supply system found in automobiles. Components were designed and dimensioned according to the needs of their rational exploitation. The three parts under analysis are battery connectors used in petrol or diesel automobiles. Material used for designing is nickel. Case studies consider a comparison between components behavior in terms of von Misses stresses, displacements, elongation, damage, life cycle, load factor or safety factor, when subjected to constraints and different loads.

245-252

Authors: Mohamad Izzat Zulkanain, Md Azree Othuman Mydin

Sensory integration provides a foundation for more complex learning and behavior. For most of us, effective sensory integration occurs automatically. For many people with autism, the process demands effort and attention with no guarantee of accuracy. Autism Spectrum Disorder (ASD) is referred as a spectrum disorder because each individual has different symptoms, sensitivities and level of functioning. Each of the autistic children’s sensory sensitivities differs from one to another. Specialized design of learning spaces for ASD children may unlock their full potential. Hence this research attempted to design sensory- friendly spaces for children with ASD to stimulate learning environment. The objectives of this research are in 3 folds; (1) to scrutinize the existing body of knowledge to ascertain relevant criteria exist to design space for ASD; (2) to evaluate three centres for children with ASD in relation to the body of knowledge examined; (3) to propose an inclusive design of spaces for children with ASD. Three case studies are chosen for these studies that are Calvary Victory Centre (Johor), Penawar Special Learning Centre (Johor) and National Autism Society Malaysia (NASOM) One Stop Centre (Selangor). Then, six components are identified to be considered in the design of the spaces and four stimuli consideration are identified that is needed to be implemented. So, designing a space that provide conducive environment for these children to use any of their senses comfortably, it may lead to effectiveness in learning process.

11-16

Authors: Cornelia-Victoria Anghel Drugarin, Vyacheslav V. Lyashenko, Muncho J. Mbunwe, M. Ayaz Ahmad

Image processing is one of the methods of analyzing and obtaining new information. Image processing methods can be applied to any image. Image processing is used in various fields of research. Among the stages of image processing, the stage of image pre-processing is important. This stage allows increasing the efficiency of the analysis of the original image. We considered the use of pre-processing for the analysis of natural polymer composites image. In this paper, we describe the possibilities of automatic processing of natural polymer composites image.

25-34

Authors: Aurel Băra, Dorian Nedelcu, Corneliu Dica

Starting from the initial geometry of the LDH 1250 CP locomotive chassis, the work aimed to optimize the geometry in the sense of maximum stresses reduction by geometric changes and the reinforcement of the structure. The optimization resulted from the need to transform the LDH 1250 Hydraulic Diesel Locomotive into the LHy-M Hybrid Locomotive, encompassing hybrid technology, powerful automation elements, as well as ergonomic redundant components that can complement and assimilate the extensive features of the old components of the rolling stock.

41-46

Authors: Petru Chioncel

This paper proposes a solution to exploit the wind potential of the Danube cluster by storing it in the Iron Gates I reservoir lake, through pumping the water downstream of the hydroelectric power plant. Storing energy by pumping water, i.e. turning the plant into a pumped storage hydroelectric plant, will chancel the unstable character of wind energy, also achieving peak load coverage under conditions of investment much be-lower to those of building a hydroelectric power plant with accumulation by pumping the Danube.

53-58

Authors: Vasile Cojocaru, Ovidiu Jitareanu

The paper presents the static analysis and the fatigue behavior analysis of the components of a tensile test equipment (hydraulic cylinder and tensile device), designed for didactic applications. The stress and the displacements that occur in the limit-loading approaches are calculated using static FEM analysis. It is also investigated the possibility of using the hydraulic cylinder and the tensile device in a redesigned equipment used for fatigue tests.

69-76

Authors: Monica-Adela Enache, Aurel Campeanu, Sorin Enache, Ion Vlad

In this paper there is analyzed, by simulation, the behavior of a reluctance synchronous motor, in case of two dynamic states caused by modifying the supply voltage. The mathematical model used, the Matlab program and the simulations obtained are presented. The paper ends with conclusions resulted by analysis. There is emphasized the fact that the dynamic stability of the motor is determined by the voltage value, as well as by the machine parameters. By simulation it is possible to establish the stability range and the ways of increasing the stability can be identified. The simulations are an absolutely necessary stage in the motor dimensioning stage.

87-98

Authors: Marius Savu Lolea, Emeric Remus Szabo, Cornelia-Victoria Anghel Drugarin, Petre Cret

This paper is dedicated to the analysis of the possibilities of assessing the level of electromagnetic pollution in the public spaces and the lucrative areas on the application of some statistical and probabilistic methods and by fuzzy modeling. The proposed models are applied to several components of the electrical grids located in Oradea or Bihor County.The first part of the paper ishows the statistic-probabilistic methods. There are presented models for calculating the level of electromagnetic pollution based on the probability of exceeding the dangerous threshold values of the characteristic magnitudes of the electromagnetic field. The second part is allocated to assessing the level of electromagnetic pollution by using fuzzy logic. There are elaborated models for fitting the values of electromagnetic field values into the risk levels given by the exposure of the organism in the electromagnetic field. By using the fuzzy toolbox from the Matlab software, the rules of inference for the specific conditions of electromagnetic field exposure and exposure, applied in power plants in Bihor County, are applied

107-112

Authors: Ion-Cornel Mituleţu, Elisabeta Spunei, Emanuel Markovican, Ion Popescu

Today's World is getting more efficient in mail deliveries or other applications using autonomous vehicles as drones because of their improved performances. The quadcopter appertains to the drone family having the advantage of flying stability light weight and accurate maneuverability. This paper describes the design and the adaptive tuning for dynamic control of a quadcopter using PID control technique. The experimental tests show improved response related to the previous results under the same input conditions.

117-126

Authors: Filip Niculescu, Adrian Savescu, Mirela Vasile

The air installation consists of high-capacity centrifugal compressors which pumps in parallel in an industrial pipe. The total air flow rate of the compressors in the pipe can be adjusted by acting on the air suction valve of each compressor so that the shut-off or opening of the compressor valve can regulate the flow rate of each compressor, which results in total flow control. The problem is to replace the analog control of the compressors with a digital control. If we have two types of compressors in the plant, the automatic setting involves closing or opening the suction valve of the compressors in a certain order so that besides the total objective to pump a particular flow we also have high energy efficiency.

137-142

Authors: Irina Maria Terfăloagă, Mihaela Dorica Stroia, Lenuţa Cîndea

The problem of additional conditions ensuring the strong convergence of Mann iteration for demicontractive mapping is investigated. A critical analysis of σ-demicontractivity condition is performed showing the applicability and how strong this condition is.

155-162

Authors: Cristian Tufisi, Gilbert-Rainer Gillich

Cristian Tufisi, Gilbert-Rainer Gillich The paper proposes modeling approaches of complex shape cracks. Structures may present many types of defects, of different irregular shapes and sizes, due to various reasons, and so it is very important for the model of the crack used to be accurate. There are three main categories for modeling of cracks; local stiffness reduction, discrete spring models, and complex models in two or three dimensions each proving to be reliable methods for generating finite element models.

9-16

Authors: Olga-Ioana Amariei, Codruţa-Oana Hamat

In the present paper, the types of decisions being taken at the top management level of a company, aim at its development and its manifestation on the competitive market, in the long run. These strategic decisions are adopted more in the conditions of risk and uncertainty determined by the forecast of market evolution.

24-34

Authors: Gaurav Kumar

This paper deals with the effects of Soret and dusty fluid on unsteady MHD flow past over porous plate. The flow is along over inclined plate with constant wall temperature and mass diffusion. The external uniform magnetic field is applied perpendicular to the inclined surface. The surface of plate is considered to be porous and fluid taken is a viscous, incompressible, an electrically conducting. The MHD flow model is consisting equations of momentum, diffusion equation and energy equation. The governing MHD flow model of partial differential equations is transformed to dimensionless equations by using dimensionless variables. To examined the solution of the MHD flow model, useful sets of the values of the parameters have been considered. The governing equations involved analytically. The results obtained have been examined with the help of graphs drawn for various parameters.

43-51

Authors: Andrea Amalia Minda, Gilbert-Rainer Gillich

It is known that experiments and hands-on learning are attractive for actual students. Furthermore, visualization permits an in-deep understanding of the learning content with beneficial consequence on the students’ performances. Consequently, virtual laboratories can aid students in achieving higher performances when studying machine design. In our research, after the students have familiarized with the theoretical aspects, they dispose of Java applets that allow performing supplementary experiments. After performing numerous experiments, which imply modifying the simulation parameters, it is observed that the students thoroughly understand the studied phenomenon.

61-68

Authors: Md Azree Othuman Mydin

For buildings and other constructions, fire protection is a must. The fear of uncontrolled fires and the desire to avoid their consequences is as ancient as human civilization. This fear has obvious enduring roots: unwanted fire is a destructive force that takes many thousands of human lives and destroys large quantities of asset. The primary objective of fire protection is to limit loss of properties and lives in the event of unexpected fires. Active fire protection is effective and efficient in most situations. However, passive fire protection, which includes the use of fire-proofing materials, provides an on-site fire resistance measure to prolong the longevity of load-bearing structures. Certainly, the nature, causes and scope of such events have changed considerably over millennia but fear and avoidance have remained as a primary human reaction and as an important human objective, respectively, for virtually every society. This paper will discuss on risk posed by fire, the passive fire protection components, conventional protection materials and thermally reactive materials. From the review, it can be concluded that active fire protection is effective and efficient in most situations passive fire protection, which includes the use of fire-proofing materials, provides an on-site fire resistance measure to prolong the longevity of load-bearing structures.

81-90

Authors: Arina Negoițescu, Adriana Tokar, Dan Negoiţescu

The article proposes an analysis of the dyeing/drying booths (DDB) operating parameters influence on the quality of products and processes that are specific to an economic agent, which has as its object of activities the design and production of integrated systems made of advanced composite materials, metallic materials and sandwich materials with different cores. In order to assess the product conformity, the production flow of products made of resin reinforced with glass fiber was followed and quality control of painted products was performed by final inspection. Final inspection is an essential factor in any scientific system of production organization and management. There have been highlighted measures in order to solve the spray-painted products nonconformities caused by the change of the dyeing/drying booths operating parameters. In this sense, solutions are proposed in order to correct the defects through three main actions.

99-104

Authors: Adrian Valentin Petrica

The paper presents the experimental achievement of heterogeneous joints, with dissimilar materials, as well as the analysis of these joints by mechanical and metallographic tests. After traction testing of the specimens, it was found that breaking occurred each time in the area of the base material, which leads to the conclusion that the strength of the welded joints is above the resistance of the base materials used.

111-117

Authors: Farah Nuratiqah Rusli, Md Azree Othuman Othuman Mydin

Malaysia is a country which is known for the heavy Islamic moral values presented in its culture and traditions. Mosques in Malaysia are well known for their beauty and captivating architecture. There are 5,300 mosques built in Malaysia as of November 2017 and the number is increasing as the years pass, but the accessibility of amenities for the PWDs is still a major problem. The mosque is not just for those without disabilities, therefore it is important to provide accessibility as to give the PwDs an equal opportunity for them to perform congregational prayers together with other devoted Muslims in respect of helping them perform their responsibilities and their social roles. Throughout history, community attitudes and physical obstructions in the built environment have barred PwDs from fully participating in the society. Access to education, employment, housing, recreation, cultural events, and transportation were denied to many people. These days, along with the emergence in the PWDs population, the mission for impartiality and equal rights is carried out aggressively. Currently, major changes in design requirements, both market-driven and legally mandated, are creating a new life system for PWDs and a new path for designers. This paper will present some of the major dilemmas faced by PwD’s when they perform prayers at mosque. Most of the mosque lack of accessibility and amenities for PwDs. Besides, PwDs are part of a community that needs to be assisted so that they can worship in comfort with the others. They also have equal rights and opportunities to live like other community members.

126-131

Authors: Adriana Tokar, Arina Negoițescu, Dan Negoiţescu, Marius Adam

From the point of view of the energy efficiency improvement and environmental protection, the recovery of waste heat from thermal systems is a necessity. The heat recovered through an economizer is a viable solution in order to achieve energy savings. For this reason, the article deals with a solution for recovering a quantity of thermal energy exhausted into the atmosphere through the dyeing/drying booths (DDB) burners stove pipes at an economic agent. The study illustrates the importance of recovering heat from flue gases in order to reduce pollutant emissions.

7-17

Authors: Basil Olufemi Akinnuli, Adeolu Adesoji Adediran, Tunde Claudius Akintayo

The present work reports investigations on mechanical and microstructural properties of foreign and locally fabricated brake disc. From safety point of view, brake disc is a crucial component of the braking system. Foreign brake disc (FBD) are known for their long life span and better mechanical properties under service condition. However, locally fabricated brake disc (LFBD) may possess similar or better mechanical properties than the foreign one. Therefore, the need to investigate their mechanical properties in order to determine which brake disc has better mechanical properties under the same service condition. It was observed that a high machinability index occurs in the locally fabricated brake disc as compared with the foreign brake disc, noticeable in the softness and weak graphite flakes formation in the matrix. Higher resistance to indentation was noticeable in the foreign brake disc as compared to the locally fabricated disc. The locally fabricated brake disc however, witnesses about 22% reduction in toughness compared to the foreign brake disc. An offshoot from this research will enhance the choice of material selection in the manufacturing of brake disc and assurance of locally made spare parts at affordable prices, and the provision of employment opportunities by establishing spare-parts production and allied industries.

33-40

Authors: Olga-Ioana Amariei, Codruța-Oana Hamat

In this article, we started from a case study in which we wanted to develop a proprietary design methodology of lower rank production systems, using several softwares. Due to its complexity, the study is truncated, making it the subject of some specialized articles. In this article the placement of a minimal number of machines is achieved, on which the technological flow can be achieved unidirectionally, by applying a new method - AOI method.

47-54

Authors: Lenuța Cîndea, Iuliana Zburlea, Cornel Hațiegan, Cristian Rudolf

The presence of stresses in the pipes of unalloyed and low alloyed steels with characteristics specified elevated temperature (hightemperature) can be put in the pipe-Dent the deformations occurring in the welded parts and the knowledge of their size allows to appreciate the ability of the test structures welded. To remove or reduce residual stresses and consequently to dimensional stabilization of the parts, use the thermal process. Comparisons have been made regarding the dimensional stabilization of the welded assembly by heat treatment of stress relief and dimensional stabilization by means of low frequency mechanical vibrations. Starting from the technological flow, two simulations were performed and the results obtained determined that the processing times were reduced in the case of vibration stabilization. The vibration stabilization system decreases thus reducing the manufacturing costs and consumes only a fraction of the heat demanded by the heat process, being one of the processes used predominantly for large welded assemblies, the intent being capable of being chipped at the place where the process of production.

67-71

Authors: Daniel Damian, Florentina Cziple, Adina Segneanu, Ioan Grozescu

Globally, the human population steady increase, expansion of urban areas, excessive industrialization including in agriculture, caused not only decrease to depletion of non-renewable resources, a rapid deterioration of the environment with negative impact on water quality, soil productivity and of course quality of life in general. This paper aims to prepare size controlled nanoparticles of aluminum oxide using a simple synthesis method. The morphology and dimensions of nanomaterial was investigated using modern analytical techniques: SEM/EDAX and XRD spectroscopy.

80-87

Authors: Marius Draghiciu, Zoltan-Iosif Korka, Gilbert-Rainer Gillich

The dynamic behaviour control of a butterfly valve is important because, when one of the valve disc natural frequency is close to the frequency of vortex shedding, which appears when the valve is fully open or partially closed, resonance may appear and vibration with significant amplitudes is generated. This paper presents an example by how the design of a butterfly valve disc can be improved by using a modal analysis performed by means of the finite element method. For this purpose, the research reveals the way in which the natural frequencies of the disc can be modified by applying stiffening ribs or changing the dimensions, respective the position of these ribs.

101-112

Authors: Maciej Dutkiewicz, Vasile Iancu, Irena Gołębiowska

In the paper an overview of passive control solutions used for reduction of vibration of civil engineering structures is presented and the special attention is put on the friction pendulum bearings applications as the example of facility supporting the frame building. The experimental results of the frame building equipped with friction pendulum bearing located on the vibration table is studied. The analysis covers the acceleration response of the frame in time domain as well as power amplitude spectrum for eleven levels of shaking table's horizontal excitation movement. On the basis of analysis the clasification of vibrations of the frame according to earthquake Intensity Modified Mercalli scale is performed. Discussion on effectivennes of friction pendulum depending on concave radius of the friction pendulum bearing and its friction coefficient is performed.

121-128

Authors: Tudorel Ene, Dorian Nedelcu

Using the analysis from the first part of the paper [1], the deck geometry is analyzed on several constructive solutions, which differ in the way of strut and lonjeron placement and in the way of loads placement. The optimal solution should take into account the maximum values of tension and distortion and the number and placement of weldings between the deck elements. Finally, a comparison between the results of the classic method and the improved method of the deck geometry is presented.

141-148

Authors: Marian Gaiceanu, Razvan Buhosu, Silviu Epure, Razvan Solea, Cristinel Dache

The objective of this paper is to improve the control quality of the DC drive system based on Arduino platform. The nameplate DC motor data are useful to provide the DC motor parameters. The cascade control loops provides good dynamic performances for the DC drive system. By using an adequate electric generator, the DC motor is loaded appropriately. Compared to the conventional control methods, in order to improve the load torque disturbances, this paper introduces feedforward load control loop. The simulation and experimental results are shown in this paper

157-162

Authors: Draghiţa Ianici, Sava Ianici

The correct operation and durability of the harmonic gear transmissions depends to a large extent on the precision of the execution, the deformation law and the durability of the flexible toothed wheel, the most requested element of the transmission. In this paper there is presented a comparative study of the deformation state of the short flexible toothed wheel of a double harmonic gear transmission for the case of four types of mechanical generators with two deformation waves: with cam, 2 rolls, 4 rolls and 2 eccentric discs. By analyzing the deformation laws of the flexible wheel for the 4 cases of generator waves, one can achieve a better understanding of how the harmonic engagement process takes place.

175-183

Authors: Pavel Kovač, Borislav Savković, Marin Gostimirovic, Dušan Jesic, Ildiko Mankova

The objective of this study is to examine the influence of machining parameters on surface finish in turning. A new approach in modeling surface roughness which uses design of experimentsis described in this paper. The values of surface roughness predicted by these models are then compared. The results showed that the proposed system can significantly increase the accuracy of the product profile when compared to the conventional approaches. The results indicate that the design of experiments with central composition plan modeling technique can be effectively used for the prediction of the surface roughness for steel difficult to machining

195-204

Authors: Feiza Memet

The concept of irreversibility is described based on theory of second law of thermodynamics. Its understanding followed by the entropy generation minimization is challenges for specialists. Nowadays advanced thermodynamics uses the entropy generation rate as a parameter able to quantify the significance of irreversibilities. Heat exchangers play a major role in the safety performance and economy of ships. The aim of this paper is to offer to marine engineers a tool to deal with optimum design of shell and tube heat exchangers by entropy generation minimization method. The modified entropy generation number is considered as the objective function in the minimization process. Thus, marine engineers’ goal is to minimize the modified entropy generation number in order to increase effectiveness and to decrease pressure drop.

211-218

Authors: Andrea Amalia Minda, Gilbert-Rainer Gillich

Due to leakage phenomena the frequencies and amplitude of the vibration signals given by the sinc function are not indicated correctly. There are interpolation methods that solve the problem of frequency evaluation but which sometimes present significant errors. This paper presents how the real value can be found if the amplitudes are known on 3 spectral lines that are in the vicinity of the actual frequency.

225-234

Authors: Lidia Nedeloni, Zoltan-Iosif Korka, Marian-Dumitru Nedeloni, Dumitru Pauliuc

Power transmissions that incorporate gears dissipate a significant amount of energy and noise. Thus, any improvement in their performance contributes to reducing energy consumption and noise pollution. In recent years, the opportunities offered by conventional technologies to increase gear performance have been fully exploited. Therefore, surface depositions on gear teeth have become increasingly important technologies in achieving objectives such as: improving energy performance, providing greater protection against superficial defects, increasing load capacity and reducing acoustic emissions generated during operation. However, gear coating technologies have begun to be developed, but the investigations are still insufficient. In this study, we carried out wear resistance investigations performed on fluoropolymer coatings for different working speeds, loads and lubrication conditions. The results point out that the deterioration rate of the coating increases with the increase of the working speed and the applied load. In addition, a slight lubrication, applied at the start of testing, leads to a noticeable improvement in wear behaviour. This study represents one step further in understanding the wear process of fluoropolymer coated gears.

247-256

Authors: Marian-Dumitru Nedeloni, Eugen Birtărescu, Lidia Nedeloni, Luminiţa Hatiegan, Sorin Laurenţiu Bogdan

This paper presents the experimental results of cavitation erosion research regarding the resistance of some steels. So, the cavitation erosion researches involve tests of hours for each test. These results are in tabular form, through charts and pictures presented in this paper.

267-278

Authors: Dan Negoiţescu, Dănuț Tokar, Adriana Tokar, Arina Negoiţescu

In the context of obligations to reduce greenhouse gas emissions to which EU countries have pledged, reducing energy consumption is a necessity of the current period. Thus, within Energy Strategy, Romania was among the first countries that have approved targets for the years 2012, 2015 and 2020. In this respect, the article presents a study regarding the assessment to an industrial consumer of the energy potential of the evacuated air jets through the exhaust systems with which technological facilities are equipped. In order to assess the possibility of utilizing the kinetic energy of the air jets evacuated by the exhaust systems, the calculation of the nominal power and power generated by a 600M2 wind turbine was performed. Based on the results obtained during the air jet speeds recording and of the recovered energy potential, it can be concluded that the evacuated air jet kinetic energy is a source that can be converted into electricity for the economic agent own consumption (insularised system).

287-301

Authors: Fiza Mohd Noh, Md Azree Othuman Mydin

The building and construction industry is a major contributor to the source of national economy. However, inappropriate construction waste management lead to various problems such as illegal dumping along the roadsides, demolition waste and disposal of construction at landfills that Malaysia is facing serious shortage of landfill space and recently the issue has become more serious throughout the country, which these have caused major government sources and environmental issue. Solid waste management is one of the environmental issues which always been a concerned to most governments. In urban areas, 46% of the population in the statistics that shows the world population has reached six billion. In 1997, generation of the municipal solid waste was about 0.49 billion tons around the globe with an estimated annual growth rate of 3.2-4.5% in develop nations and 2-3% in developing countries. The characteristics of solid waste generated were changed due to the rapid urbanization and industrialization.

312-319

Authors: Oyati E.N., Olotu Yahaya

Modelling of stream flow and discharge of river Awara under changed climate conditions using CLIMGEN for stochastic weather generation and WEAP model was used to simulate reserviour storage volume, water demand and river discharges at high spatial resolution (0.5°×0.5°, total 66,420 grid cells). Results of CLM-Based flow measurement shows a linear regression with R2 = 0.99 for IFPRI-MNP- IGSM_WRS calibration. Sensitivity simulation of ambient long-term shows an increase in temperature with 0.5oc thus the results of the studies generally show that annual runoff and river discharges could largely decrease. The projection of water demand 150 million m3 by 2020 against the reservoir storage volume 60 million m3 and decrease in rainfall depth by -5.7 mm. The output of the combined models used in this study is veritable to create robust water management system under different climate change scenarios.

329-332

Authors: Adrian Valentin Petrica

The bond strength of the thermally sprayed coatings is one of the most important features in the assessment of deposition quality. Standardized methods for determining the adhesion of thermally sprayed coatings refer to the layers deposited on flat surfaces and on the outer diameter of the cylindrical parts. Thermal spray deposition on internal cylindrical surfaces is particularly difficult for low diameter. In the case of inner cylindrical surfaces, one of the parameters that strongly influence adhesion is the diameter of the parts on which the deposit is made. The proposed method of measuring the adhesion of thermally sprayed layers offers concrete values of shear breaking force. This method can be successfully used especially for experimental samples having a small internal diameter.

338-351

Authors: Uday Singh Rajput, Gaurav Kumar

Effects of rotation and radiation on unsteady MHD flow past a vertical plate with variable wall temperature and mass diffusion in the presence of Hall current is studied here. Earlier we studied chemical reaction effect on unsteady MHD flow past an exponentially accelerated inclined plate with variable temperature and mass diffusion in the presence of Hall current. We had obtained the results which were in agreement with the desired flow phenomenon. To study further, we are changing the model by considering radiation effect on fluid, and changing the geometry of the model. Here in this paper we are taking the plate positioned vertically upward and rotating with velocity W. Further, medium of the flow is taken as porous. The plate temperature and the concentration level near the plate increase linearly with time. The governing system of partial differential equations is transformed to dimensionless equations using dimensionless variables. The dimensionless equations under consideration have been solved by Laplace transform technique. The model contains equations of motion, diffusion equation and equation of energy. To analyze the solution of the model, desirable sets of the values of the parameters have been considered. The governing equations involved in the flow model are solved by the Laplace-transform technique. The results obtained have been analyzed with the help of graphs drawn for different parameters. The numerical values obtained for the drag at boundary and Nusselt number have been tabulated. We found that the values obtained for velocity, concentration and temperature are in concurrence with the actual flow of the fluid.

356-371

Authors: Nicolae–Doru Stănescu, Nicolae Pandrea

This paper discusses the problem of simultaneous collisions between an ellipsoid and some planar surfaces. The approach is one based on the theory of screws and uses the notion of inertance. The authors consider that the coefficients of restitution are different for each planar surface and they obtain the velocities after the collision. An example concludes the theory

380-385

Authors: Mihaela Dorica Stroia, Cornelia Victoria Anghel Drugarin

It’s well known that trends worldwide are towards automation. We look for having automatic, or worst case semi-automatic, processes, systems, machines, with the purpose to produce a finished good in the shortest time. Consider we have a semi-automatic system used to obtain air separation. The entire system is ‘supervised’ by a so called DCS (Distributed Control System) with the role to command several vanes with different functions. Human factor interferes with DCS only for digital data input. The system converts digital information in analogical signals in order to control pressure or flow. The issues of interest addressed in the present paper concern losses and gains brought by automation for this particular case of study.

390-395

Authors: Fanel Dorel Scheaua

Modern structures made today benefit from quality materials that ensure their considerably long life. In addition to these materials, specific methods are used in order to counteract the dynamic actions that may require their structural strength and engineers greatest concern is to ensure an optimal degree of earthquake stability. Among the methods are used insulation and dissipation solutions by using special mechanical systems, which can counteract the earthquake action. A hydrostatic drive is described in this paper, which can also be attached to the structure in order to consume some of the earthquake energy, resulting in a diminished amount of energy transmitted to the structural frames. It is considered an energy dissipation system, whose operating principle is highly nonlinear.

402-410

Authors: Irina Maria Terfaloaga

The algorithms for solving convex feasibility problems receive great attention for their extraordinary utility and broad applicability in many areas of classical mathematics and modern physical sciences, (for example: computerized tomography). Usually, the convex feasibility problems are solved by projection algorithms. The projection method is a particular case of the Mann iteration process. Numerical examples are given.

418-428

Authors: Aw Nien Wei, Md Azree Othuman Mydin

It should be pointed out that salt crystallisation and rising dampness are two separate but interconnected processes. Both of these damages must be understood if damage is to be minimized and if corrective measures are to be successful. However, the term rising damp has been usually used to cover both aspects, it tends to overlook the role of salt, and issues that will increasingly significant due to the buildings are getting older and as the soils are becoming more saline. Hence this paper will focus on background and an understanding of salt crystallisation and rising damp problems. Furthermore, the discussion also will include the indications, causes and effects of both damages.

11-22

Authors: Olayinka Oluwole Agboola, Peter Pelumi Ikubani, Adeolu Adesoji Adediran, Rotimi Adedayo Ibikunle, Bamidele Temitope Ogunsemi

Gears as power transmission devices are capable of changing the speed, torque, and direction of a power source and are considered to be one of the most important devices used in many types of machinery owing to their durability and higher power transmission efficiency. Worm gears as a type of gear are widely used for transmitting power at high velocity ratios between non-intersecting shafts. Worm gears are very useful in machine design but its design requires a lot of design assumptions and calculations. To achieve a rapid design devoid of errors, there is need to have a customized computer program capable of designing worm gears using standardized design equations; and that is what WormCAD stands for. The software was designed using JavaScript programming language and the Node.js platform. The WormCAD was tested to be accurate, faster and convenient hence it will be a viable software to be used by worm gear designers.

31-38

Authors: Alexandru Victor Amariei, Daniel Mihai Amariei

In the present paper is followed an optimal dividing of five operators on the same number of machines, using the Hungarian algorithm through Network Modeling module, in the WinQSB software.

45-

Authors: Olga-Ioana Amariei, Codruţa Oana Hamat, Vadim Chistruga

In the present paper a series of advantages of the CPM method are presented, focusing on the optimization of design duration of an injection camshaft, by cost criteria. The minimum duration of finalizing the design of the injection camshaft will be determined, as well as the total cost associated to this project, normally, and then under crash regime. At the end, two types of sensitivity analysis will be performed: Meeting the desire completation time and Meeting the desired budget cost.

61-66

Authors: Cornelia Victoria Anghel Drugarin, Silviu Draghici, Eugen Raduca

Team Viewer software is used to remote control our PC. We can use this remote control technology to desktop sharing, online conferences and for file transfer between computers. Basically, using this software, you can ask for help a friend, or professional software to solve problems from a distance, without it having to be physically go to each client / friend in part. After installed and configured Team Viewer application, is complete, we can remote control the computer.

73-88

Authors: Constantin Gabriel Dobrean, Marius Biriescu, Marțian Moț, Gheorghe Madescu, Marian Greconici

The study shows the numerical simulation of the magnetic field for a permanent magnet synchronous generator prototype. Through the study, the OPERA software environment, a program based on the numerical computation using the finite element method and used for the virtual simulation of the synchronous generator prototype, is shown. This 5 kVA power, permanent magnet and low speed prototype is meant for uses in hydraulic driven applications, namely wind applications, and was performed within a cooperations between the Faculty of Automation and Computers and the Faculty of Electrical and Power Engineering within the “Politehnica” University of Timișoara.

95-102

Authors: Tudorel Ene

The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. One describes the MIG welding method in which the electromagnet is used as well as its preliminary calculus.

115-120

Authors: Marius Constantin Georgescu

This paper presents a case study regarding the analysis of electricity consumption for a slaughter house as industrial consumer. This analysis takes into consideration the load curves during a whole year time delay. Based on data processing statistical methods within this case study, the author develops a forecasting procedure with time series analysis in order to better estimate the electricity consumption during a year. For the considered consumer, continuous supplied all the day by two power delivery networks of 20kV by means of an electrical transformer, practical results have been considered in order to verify the accuracy of statistical analysis.

127-134

Authors: Sava Ianici, Draghiţa Ianici

The paper presents a study of the dynamic behaviour of flexible toothed wheel whit combined radial teeth (exterior, respectively interior), of a double harmonic gear transmission (DHGT). We present a comparative-critical analysis of two deformation laws of the flexible toothed wheel (one elliptical and other cosine type), using a set of computer programs of own conception, written in Visual Basic. We demonstrate a similarity between cosine deformation law of the flexible wheel and the elliptical law, proving that the cosine deformation law can approximate the elliptical law with a high degree of accuracy.

145-155

Authors: Sergiu Ivas, Mădălin Costin

In this paper is proposed a method for computing of optimal geometric dimensions of a DC electromagnet, based on the imposed dynamical characteristics. For obtaining the optimal design, it is built the criterion function in an analytic form that may be optimized in the order to find the constructive solution. Numerical simulations performed in Matlab software confirm the proposed work. The presented method can be extended to other electromagnetic devices which frequently operate in dynamic regime.

173-182

Authors: Zoltan-Iosif Korka, Constantin-Viorel Campian, Daniel-Iosif Balint, Vasile Cojocaru, Ana-Maria Budai

CFD (Computational Fluid Dynamic) is today a standard procedure for analyzing and simulating the flow through several hydraulic machines. In this process, the fluid flow domain is divided into small volumes where the governing equations are converted into algebraic ones, which are numerically solved. Computational results strongly depend on the applied mathematical model and on the numerical methods used for converting the governing equations into the algebraic ones. The goal of the paper is to evaluate, by numerical simulation, the hydraulic loads (forces and torques on the runner blades) of an existent Kaplan turbine and to compare them with the experimental results obtained from model test.

189-194

Authors: Ion-Cornel Mituletu, Dorian Anghel

The present paper describes research results considering the automatic control of a prehension module using a dual shape memory alloy (SMA) actuator. The offspring targeted a high-speed prehension appliance by means of adjusting constants of a PID controller. Furthermore, SMA springs are individually driven according each one’s particularities, aiming at prolonging life of dual SMA actuator, with respect to parametric values given by manufacturer. Problem of process control is approached from few perspectives: automatic control, software implementation and electronic performance, the first being the one subjected to following discussion.

203-210

Authors: Jean Loius Ntakpe, Nicoleta Gillich, Gilbert-Rainer Gillich

Damage detection and nondestructive evaluation of mechanical and civil engineering structures are nowadays very important to assess the integrity and ensure the reliability of structures. Thus, frequency evaluation becomes a crucial issue, since this modal parameter is mainly used in structural integrity assessment. The herein presented study highligts the possibility of increasing the frequency readability by involving a simple and cost-effective method.

222-227

Authors: Olaiya S., Mahmud Hauwau, Eboreime Lucky, Afolabi O.C.

Abattoir wastewater has a complex composition and very harmful to the environment. There is always need for reduction in the impact of natural and most especially anthropogenic pollution to enhance water quality, food safety and sustainable development. Physico-chemical and microbial properties analysed using standard laboratory procedures were temperature, pH, conductivity, turbidity, total solid (TS), total dissolved solid (TDS), total suspended solid (TSS), dissolved oxygen (DO), acidity, alkalinity, total hardness, calcium and magnesium hardness, chloride, iron and nitrate. Temperature ranged from 28.04- 29.12C, pH between was 7.67-8.01, Alkalinity is 0.45 mg/l, TS, BOD and TSS were 700 mm/l, 48 mm/l, 500 mm/l, DO is 2,100 ppm. Holistic outputs of the investigation revealed various water samples were contaminated with E. Coli and other enteric bacteria. The presence of coliform staphylococcus aures indicated the presence of microorganisms which are associated with water borne disease.

239-248

Authors: Omholua Anthony Omokhudu, Ujam A.J., Uviesherhe Okiemute Edijana

Nigerian grown species of bamboo called bambusa vulgaris which was examined to analyze its tensile strength. The fibre characteristics and tensile strength were investigated at three different fibre lengths and fibre loadings i.e 10, 30,50mm and 10, 30, 50 wt.% respectively. Fibre length was varied in each fibre loading from 10mm to 50mm, the tensile strength of the three different series of composites varies from 28.32Mpa to 38.10Mpa. The predicted optimum tensile strength is 44.51Mpa. Generated results have been validated by the confirmation of experiments at three replications, when the control factors were set at 30mm and 30% wt or (level 2, level 2), using Taguchi’s design of experiments approach. It was observed from the analysis of variance of the samples that there is a variation in the increase of tensile strength of the bamboo that are dependent on the fibre length and fibre loading used. The percentage contributions of parameter according to the pooled ANOVA for signal-to- Noise ratio showed that the fibre length (36.61%) in controlling variation and mean strength is significantly smaller than the fibre loading (44.15%).

261-272

Authors: Ion Paraschiv, Ion Voncilă, Mădălin Costin, Sergiu Ivas

The paper presents the interaction between electric field of a high voltage line and the body of a human being placed near the line, for normal situation, when human being is placed on the ground or in accidental situation when the human being is placed near the line. The research is based on a simplified model of human being solved by finite elements method. Both aspects as field measure (as a disturbance for human being) and energy one has been pointed out and, finally, forces via weighted tensor developed between field and human being. The work results, developed in this paper, may be successful used in the order to improve the normative exigencies for different practice field interactions.

283-290

Authors: Eugen Răduca, Marius Schmidt, Cornel Haţiegan, Ioan Hălălae, Silviu Drăghici

The paper presents an application based on a PLC Simatic S7-1200, using the "PID_Compact" logical function, which can be used for the improvement of control systems. We also present a practical application: a system for the improvement of the transportation system of the flour in a grain mill using "PID Compact" .

305-319

Authors: Uday Singh Rajput, Gaurav Kumar

Chemical reaction effect on unsteady MHD flow past an exponentially accelerated inclined plate with variable temperature and mass diffusion in the presence of Hall current is studied here. The fluid considered is gray, absorbing-emitting radiation but a non-scattering medium. The Governing equations involved in the present analysis are solved by the Laplace-transform technique. The velocity profile is discussed with the help of graphs drawn for different parameters like Grashof number, mass Grashof Number, Prandtl number, Chemical reaction parameter, Hall current parameter, accelerated parameter, the magnetic field parameter and Schmidt number, and the numerical values of skin-friction and Sherwood number have been tabulated.

329-336

Authors: Fanel Dorel Scheaua

The cultivation of agricultural land represents an important field of interest for all countries because through this area basic food is provided for human communities. Agricultural machines are considered part of special mechanical equipments category intended to perform mechanized works in farmlands, in order to obtain the optimal harvests. This paper shows a functional description of sprayer installation model which can be attached to the agricultural tractors. It represents an auxiliary installation capable of preparing the fluid mixtures to achieve the application of different sanitary treatments (herbicides, fungicides, insecticides) on field crops, using the hydraulic system of the agricultural tractor to which is connecting. The mounting solution for the installation is at the rear side of the tractor being the model widely used on most constructive pattern of agricultural tractors. Also a CFD analysis it was conducted on two nozzle models that can be used for treatment application on crops in agricultural fields. The results are presented for each nozzle model highlighting the fluid velocity substance coverage and total pressure for each model.

347-356

Authors: Adriana Tokar, Arina Negoițescu

The paper presents issues relating to existing standards underlying seismic design restrictions for non-structural components (NSC) related to constructions. Are presented measures that can be implemented to maintain a high level of safety in case of earthquake, natural gas plants, which due to the flammability of fuel, carry some risk of fire or explosion. The purpose of this paper is to highlight the need for seismic design of facilities using natural gas fuel for new buildings but also to review the existing installations in buildings by taking mandatory measures.

369-377

Authors: Olotu Yahaya, Omoregie Alexander, Dirisu H.O., Alhassan A.I.

The research study strongly focused on creating strong mechanism for measuring and evaluating soil moisture content comparing PR2 capacitance moisture meter and gravimetric approach. PR2 moisture meter shows a better performance accuracy of ± 6%; 0.06 m3/m3 and intercept a0 =1.8; indicating the field is heavy clay. It measures to 1000 mm depth with high precision; while realistic result could not be obtained from gravimetric method at this measuring depth. Therefore, effective soil moisture measuring, monitoring and evaluation can be achieved with PR2 moisture meter.