Abstract: After cold pressing of pumpkin oil, the defatted oil cake (PUOC) was utilised as raw material for processing of bio-functional hydrolysates. In this study, the in vitro bioactivity of an alcalase (AH) and a pepsin hydrolysate (PH) prepared from the major pumpkin 12S globulin (cucurbitin) are compared. The hydrolysates were produced at optimum reaction conditions (temperature, pH) for the enzymes, during 60min. The bioactivity testing included antioxidant and angiotensin I converting enzyme inhibitory activity assays. The hydrolysates showed high potential as natural antioxidants and possibly antihypertensive agents in functional food or nutraceuticals. Additionally, preliminary studies have shown that both hydrolysates could exhibit modest α-amylase inhibitory activity, which indicates on their hypoglycemic potential.
Abstract: In this work the concentration of steepwater from corn starch industry is monitored using ultrafiltration membrane. The aim was to examine the conditions of ultrafiltration of steepwater by applying the membrane of 2.5nm. The parameters that vary during the course of ultrafiltration, were the transmembrane pressure, flow rate, while the permeate flux and the dry matter content of permeate and retentate were the dependent parameter constantly monitored during the process. Experiments of ultrafiltration are conducted on the samples of steepwater, which were obtained from the starch wet milling plant „Jabuka“ Pancevo. The procedure of ultrafiltration on a single-channel 250mm lenght, with inner diameter of 6.8mm and outer diameter of 10mm membrane were carried on. The membrane is made of a-Al2O3 with TiO2 layer obtained from GEA (Germany). The experiments are carried out at a flow rate ranging from 100 to 200lh-1 and transmembrane pressure of 1-3 bars. During the experiments of steepwater ultrafiltration, the change of permeate flux, dry matter content of permeate and retentate, as well as the absorbance changes of the permeate and retentate were monitored. The experimental results showed that the maximum flux reaches about 40lm-2h-1. For responses obtained after experiments, a polynomial model of the second degree is established to evaluate and quantify the influence of the variables. The quadratic equitation fits with the experimental values, where the coefficient of determination for flux is 0.96. The dry matter content of the retentate is increased for about 6%, while the dry matter content of permeate was reduced for about 35-40%, respectively. During steepwater ultrafiltration in permeate stays 40% less dry matter compared to the feed.
Abstract: In the paper environmental impact analysis the optimal Diesel engine for a light helicopter was performed. The paper consist an answer to the question of what the optimal Diesel engine for a light helicopter is, taking into consideration its expected performance and design capacity. The use of turbocharged engine with self-ignition and an electronic control system can substantially reduce the negative impact on the environment by decreasing toxic substance emission, fuel consumption and therefore carbon dioxide emission. In order to establish the environmental benefits of the diesel engine technologies, mathematical models were created, providing additional insight on the environmental impact and performance of a classic turboshaft and an advanced diesel engine light helicopter, incorporating technology developments.
Abstract: This study presents the optimal design and formulation of a kinematic model of a flexible slider crank mechanism. The objective of the proposed innovative design is to take extra advantage of the compliant mechanism and maximize the fatigue life by applying the Taguchi method. A formulated kinematic model is developed using a pseudo-rigid-body model (PRBM). By means of mathematic models, the kinematic behaviors of the flexible slider crank mechanism are captured using MATLAB software. Finite element analysis (FEA) is used to show the stress distribution. The results show that the optimal shape of the flexible hinge includes a force of 8.5N, a width of 9mm and a thickness of 1.1mm. Analysis of variance shows that the thickness of the proposed hinge is the most significant parameter, with an F test of 15.5. Finally, a prototype is manufactured to prepare for testing the kinematic and dynamic behaviors.
Abstract: Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require systematic investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 300 series austenitic stainless steels have been evaluated in the temperature ranges of 200-800oC and 200-900oC. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property.
Abstract: High strength Fe-36Ni-base Invar alloys containing Al contents up to 0.3 weight percent were cast into ingots and thermodynamic equilibrium during solidification has been investigated in this study. From the thermodynamic simulation using Thermo-Calc®, it has been revealed that equilibrium phases which can be formed are two kinds of MC-type precipitates, MoC, and M2C carbides. The mu phase was also expected to form by addition of aluminum. Microstructure observation revealed the coarse precipitates in the as-cast ingots, which was non-equilibrium phase and could be resolved by the successive heat treatment. With increasing Al contents up to 0.3 wt.%, tensile strength of Invar alloy increased as 1400MPa after cold rolling and thermal expansion coefficient increased significantly. Cold rolling appeared to dramatically decrease thermal expansion coefficient.
Abstract: Results of a field study carried out at Trinitapoli (Puglia region, southern Italy) on the irrigation of an artichoke crop with three types of water (secondary-treated wastewater, SW; tertiary-treated wastewater, TW; and freshwater, FW) are reported. Physical, chemical and microbiological analyses were performed on the irrigation water, and on soil and yield samples.
The levels of most of the chemical parameters, such as electrical conductivity, total suspended solids, Na+, Ca2+, Mg+2, K+, sodium adsorption ratio, chemical oxygen demand, biological oxygen demand over 5 days, NO3 –N, total N, CO32, HCO3, phenols and chlorides of the applied irrigation water were significantly higher in SW compared to GW and TW. No differences were found for Mg2+, PO4-P, K+ only between SW and TW. Although the chemical parameters of the three irrigation water sources were different, few effects on the soil were observed. Even though monitoring of Escherichia coli showed high SW levels, which were above the limits allowed under Italian law (DM 152/2006), contamination of the soil and the marketable yield were never observed. Moreover, no Salmonella spp. were detected in these irrigation waters; consequently, they were absent in the plants. Finally, the data on the quantitative-qualitative parameters of the artichoke yield with the various treatments show no significant differences between the three irrigation water sources. Therefore, if adequately treated, municipal wastewater can be used for irrigation and represents a sound alternative to conventional water resources.
Abstract: Speed, power consumption and area, are some of the most important factors of concern in modern day memory design. As we move towards Deep Sub-Micron Technologies, the problems of leakage current, noise and cell stability due to physical parameter variation becomes more pronounced. In this paper we have designed an 8T Read Decoupled Dual Port SRAM Cell with Dual Threshold Voltage and characterized it in terms of read and write delay, read and write noise margins, Data Retention Voltage and Leakage Current. Read Decoupling improves the Read Noise Margin and static power dissipation is reduced by using Dual-Vt transistors. The results obtained are compared with existing 6T, 8T, 9T SRAM Cells, which shows the superiority of the proposed design. The Cell is designed and simulated in TSPICE using 90nm CMOS process.
Abstract: The more homogenized population taken over by the Republic immediately after the Ottoman was being canalized towards the goal of national identity and the historical and cultural structure of the nation was being readdressed and redefined. Modernization and Westernization history of the new Turkey, which started with Ottoman reforms and took its final form with the Kemalist nation-state, politically resulted in transformation from a multinational empire to a “nation-state” and adopted reaching to the level of Western civilizations as a sociology ideal. This objective of change will be achieved, on the one hand, by finding the Turkish culture which was preserved only by the society and by instilling Western civilization to national culture, on the other hand. In line with this, it is seen that in musical considerations while Turkish folk music was accepted and adopted as an indispensible part of Turkish identity, Turkish classical music was refused on the ground that it was not a part of Turkish identity. Again in this period, it is seen that with the notion of cultural reform, which is a part of “nation building”, the desire to create a national music to be performed with Western techniques brought along deliberate interventions to folk music.
Abstract: Two multisensor system architectures for navigation
and guidance of small Unmanned Aircraft (UA) are presented and
compared. The main objective of our research is to design a compact,
light and relatively inexpensive system capable of providing the
required navigation performance in all phases of flight of small UA,
with a special focus on precision approach and landing, where Vision
Based Navigation (VBN) techniques can be fully exploited in a
multisensor integrated architecture. Various existing techniques for
VBN are compared and the Appearance-Based Navigation (ABN)
approach is selected for implementation. Feature extraction and
optical flow techniques are employed to estimate flight parameters
such as roll angle, pitch angle, deviation from the runway centreline
and body rates. Additionally, we address the possible synergies of
VBN, Global Navigation Satellite System (GNSS) and MEMS-IMU
(Micro-Electromechanical System Inertial Measurement Unit)
sensors, and the use of Aircraft Dynamics Model (ADM) to provide
additional information suitable to compensate for the shortcomings of
VBN and MEMS-IMU sensors in high-dynamics attitude
determination tasks. An Extended Kalman Filter (EKF) is developed
to fuse the information provided by the different sensors and to
provide estimates of position, velocity and attitude of the UA
platform in real-time. The key mathematical models describing the
two architectures i.e., VBN-IMU-GNSS (VIG) system and VIGADM
(VIGA) system are introduced. The first architecture uses VBN
and GNSS to augment the MEMS-IMU. The second mode also
includes the ADM to provide augmentation of the attitude channel.
Simulation of these two modes is carried out and the performances of
the two schemes are compared in a small UA integration scheme (i.e.,
AEROSONDE UA platform) exploring a representative cross-section
of this UA operational flight envelope, including high dynamics
manoeuvres and CAT-I to CAT-III precision approach tasks.
Simulation of the first system architecture (i.e., VIG system) shows
that the integrated system can reach position, velocity and attitude
accuracies compatible with the Required Navigation Performance
(RNP) requirements. Simulation of the VIGA system also shows
promising results since the achieved attitude accuracy is higher using
the VBN-IMU-ADM than using VBN-IMU only. A comparison of
VIG and VIGA system is also performed and it shows that the
position and attitude accuracy of the proposed VIG and VIGA
systems are both compatible with the RNP specified in the various
UA flight phases, including precision approach down to CAT-II.
Abstract: The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is considered experimentally. The present study was made for supercritical flow of Froude number varying between 2 to 9 and approach to expanded channel width ratios 0.4, 0.5, 0.6 and 0.8. Physical explanations of the variation of these characteristics under varying flow conditions are discussed based on the observation drawn from experimental results. The analytical equation for the sequent depth ratio in an abruptly expanding channel as given by eminent hydraulic engineers are verified well with the experimental data for all expansion ratios, and the empirical relation was also verified with the present experimental data.
Abstract: A numerical study based on the Lattice Boltzmann Method (LBM) is proposed to solve one, two and three dimensional heat and mass transfer for isothermal carbonization of thick wood particles. To check the validity of the proposed model, computational results have been compared with the published data and a good agreement is obtained. Then, the model is used to study the effect of reactor temperature and thermal boundary conditions, on the evolution of the local temperature and the mass distributions of the wood particle during carbonization
Abstract: This paper deals with the direct torque control (DTC) of the induction motor. This type of control allows decoupling control between the flux and the torque without the need for a transformation of coordinates. However, as with other hysteresis-based systems, the classical DTC scheme represents a high ripple, in both the electromagnetic torque and the stator flux and a distortion in the stator current. As well, it suffers from variable switching frequency. To solve these problems various modifications, in conventional DTC scheme, have been made during the last decade. Indeed the DTC based on space vector modulation (SVM) has proved to generate very low ripples in torque and flux with constant switching frequency. It also shows almost the same dynamic performances as the classical DTC system. On the other hand, fuzzy logic is considered as an interesting alternative approach for its advantages: Analysis close to the exigencies of user, ability of nonlinear systems control, best dynamic performances and inherent quality of robustness.
Therefore, two fuzzy direct torque control approaches, for the induction motor fed by SVM-voltage source inverter, are proposed in this paper. By using these two approaches of DTC, the advantages of fuzzy logic control, space vector modulation, and direct torque control method are combined. The performances of these DTC schemes are evaluated through digital simulation using Matlab/Simulink platform and fuzzy logic tools. Simulation results illustrate the effectiveness and the superiority of the proposed Fuzzy DTC-SVM schemes in comparison to the classical DTC.
Abstract: The radiative heat transfer problem is investigated numerically for 2D complex geometry biomass pyrolysis reactor composed of two pyrolysis chambers and a heat recuperator. The fumes are a mixture of carbon dioxide and water vapor charged with absorbing and scattering particles and soot. In order to increase gases residence time and heat transfer, the heat recuperator is provided with many inclined, vertical, horizontal, diffuse and grey baffles of finite thickness and has a complex geometry. The Finite Volume Method (FVM) is applied to study radiative heat transfer. The blocked-off region procedure is used to treat the geometrical irregularities. Eight cases are considered in order to demonstrate the effect of adding baffles on the walls of the heat recuperator and on the walls of the pyrolysis rooms then choose the best case giving the maximum heat flux transferred to the biomass in the pyrolysis chambers. Ray effect due to the presence of baffles is studied and demonstrated to have a crucial effect on radiative heat flux on the walls of the pyrolysis rooms. Shadow effect caused by the presence of the baffles is also studied. The non grey radiative heat transfer is studied for the real existent configuration. The Weighted Sum of The Grey Gases (WSGG) Model of Kim and Song is used as non grey model. The effect of soot volumetric fraction on the non grey radiative heat flux is investigated and discussed.
Abstract: Recent concerns of the growing impact of aviation on
climate change has prompted the emergence of a field referred to as
Sustainable or “Green” Aviation dedicated to mitigating the harmful
impact of aviation related CO2 emissions and noise pollution on
the environment. In the current paper, a unique “green” business
jet aircraft called the TransAtlantic was designed (using analytical
formulation common in conceptual design) in order to show the
feasibility for transatlantic passenger air travel with an aircraft
weighing less than 10,000 pounds takeoff weight. Such an advance in
fuel efficiency will require development and integration of advanced
and emerging aerospace technologies. The TransAtlantic design is
intended to serve as a research platform for the development of
technologies such as active flow control. Recent advances in the field
of active flow control and how this technology can be integrated
on a sub-scale flight demonstrator are discussed in this paper. Flow
control is a technique to modify the behavior of coherent structures
in wall-bounded flows (over aerodynamic surfaces such as wings and
turbine nozzles) resulting in improved aerodynamic cruise and flight
control efficiency. One of the key challenges to application in manned
aircraft is development of a robust high-momentum actuator that
can penetrate the boundary layer flowing over aerodynamic surfaces.
These deficiencies may be overcome in the current development
and testing of a novel electromagnetic synthetic jet actuator which
replaces piezoelectric materials as the driving diaphragm. One of
the overarching goals of the TranAtlantic research platform include
fostering national and international collaboration to demonstrate (in
numerical and experimental models) reduced CO2/ noise pollution
via development and integration of technologies and methodologies
in design optimization, fluid dynamics, structures/ composites,
propulsion, and controls.
Abstract: Multilevel inverter is a promising inverter topology for high voltage and high power applications. This inverter synthesizes several different levels of DC voltages to produce a stepped AC output that approaches the pure sine waveform. The three different topologies, diode-clamped inverter, capacitor-clamped inverter and cascaded h-bridge multilevel inverter are widely used in these multilevel inverters. Among the three topologies, cascaded h-bridge multilevel inverter is more suitable for photovoltaic applications since each PV array can act as a separate dc source for each h-bridge module. This research especially focus on photovoltaic power source as input to the system and shows the potential of a Single Phase Cascaded H-bridge Eleven level inverter governed by the fuzzy logic controller to improve the power quality by reducing the total harmonic distortion at the output voltage. Hence the efficiency of the system will be improved. Simulation using MATLAB/SIMULINK has been done to verify the performance of cascaded h-bridge eleven level inverter using sinusoidal pulse width modulation technique. The simulated output shows very favorable result.
Abstract: Humic acids (HA) were produced by a Trichoderma
viride strain under submerged fermentation in a medium based on the
oil palm empty fruit bunch (EFB) and the main variables of the
process were optimized by using response surface methodology. A
temperature of 40°C and concentrations of 50g/L EFB, 5.7g/L potato
peptone and 0.11g/L (NH4)2SO4 were the optimum levels of the
variables that maximize the HA production, within the
physicochemical and biological limits of the process. The optimized
conditions led to an experimental HA concentration of 428.4±17.5
mg/L, which validated the prediction from the statistical model of
412.0mg/L. This optimization increased about 7–fold the HA
production previously reported in the literature. Additionally, the
time profiles of HA production and fungal growth confirmed our
previous findings that HA production preferably occurs during fungal
sporulation. The present study demonstrated that T. viride
successfully produced HA via the submerged fermentation of EFB
and the process parameters were successfully optimized using a
statistics-based response surface model. To the best of our
knowledge, the present work is the first report on the optimization of
HA production from EFB by a biotechnological process, whose
feasibility was only pointed out in previous works.
Abstract: It is well documented that introductory computer
programming courses are difficult and that failure rates are high. The
aim of this project was to reduce the high failure and withdrawal rates
in learning to program. This paper presents a number of changes in
module organization and instructional delivery system in teaching
CS1. Daily out of class help sessions and tutoring services were
applied, interactive lectures and laboratories, online resources, and
timely feedback were introduced. Five years of data of 563 students
in 21 sections was collected and analyzed. The primary results show
that the failure and withdrawal rates were cut by more than half.
Student surveys indicate a positive evaluation of the modified
instructional approach, overall satisfaction with the course and
consequently, higher success and retention rates.
Abstract: The effects of soil inoculation with phosphorien-containing phosphate-dissolving bacteria (PDB) and/or magnesium (Mg) foliar application at the rates of 0, 0.5 and 1mM on growth, green pod and seed yields, and chemical constituents of Pisum sativum L. grown on a sandy calcareous soil were investigated. Results indicated that PDB and/or Mg significantly increased shoot length, number of branches plant–1, total leaf area plant–1 and canopy dry weight plant–1, leaf contents of pigments, soluble sugars, free proline, nitrogen, phosphorus, potassium, magnesium, and calcium, and Ca/Na ratio, while leaf Na content was reduced. PDB and/or Mg also increased green pod and seed yields. We concluded that PDB and Mg have pronounced positive effects on Pisum sativum L. plants grown on sandy calcareous soil. PDB and Mg, therefore, have the potential to be applied for various crops to overcome the adverse effects of the newly-reclaimed sandy calcareous soils.
Abstract: Occupational Self Efficacy (OSE) reflects the
conviction of a person’s ability to fulfill his job related behavior at a
perfectly acceptable level to the employer. Transformational
leadership improves followers’ commitment by influencing their
needs, values, and self-esteem. Employees also develop a dyadic
relationship with their immediate superiors. Study was conducted
amongst one hundred and twenty two (122) bank managers in Sri
Lanka. They were selected based on multi-stage (seniority in the
hierarchy, gender, department-wise etc.) stratified random sampling.
Major objectives of this study were to analyze the impact of
Transformational leadership style, and OSE along with Sociodemographic
factors, and Career, Job and Organizational experience,
to the Career satisfaction of managers. SPSS software was used for
parametric and non-parametric statistical analyses. Career satisfaction
had positive impacts with their Transformational leadership style, and
their relationships with the immediate superior. Impact of sociodemographic
factors, and career exposure to career satisfaction was
assessed.