Abstract: Starting in 2020, an EU-wide CO2-limitation of
95 g/km is scheduled for the average of an OEMs passenger car fleet.
Taking that into consideration additional improvement measures of
the Diesel cycle are necessary in order to reduce fuel consumption
and emissions while boosting, or at the least, keeping performance
values at the same time.
The present article deals with the possibilities of an optimized
air/water charge air cooler, also called iCAC (indirect Charge Air
Cooler) for a Diesel passenger car amongst extreme-boundary
conditions. In this context, the precise objective was to show the
impact of improved intercooling with reference to the engine working
process (fuel consumption and NOx-emissions). Several extremeboundaries
- e.g. varying ambient temperatures or mountainous
routes - that will become very important in the near future regarding
RDE (Real Driving emissions) were subject of the investigation.
With the introduction of RDE in 2017 (EU6c measure), the
controversial NEDC (New European Driving Cycle) will belong to
the past and the OEMs will have to avoid harmful emissions in any
conceivable real life situation.
This is certainly going to lead to optimization-measurements at the
powertrain, which again is going to make the implementation of
iCACs, presently solely used for the premium class, more and more
attractive for compact class cars. The investigations showed a benefit
in FC between 1 and 3% for the iCAC in real world conditions.
Abstract: Cement-based grouts has been used successfully to
repair cracks in many concrete structures such as bridges, tunnels,
buildings and to consolidate soils or rock foundations. In the present
study the rheological characterization of cement grout with
water/binder ratio (W/B) is fixed at 0.5. The effect of the replacement
of cement by bentonite (2 to 10% wt) in presence of superplasticizer
(0.5% wt) was investigated. Several rheological tests were carried out
by using controlled-stress rheometer equipped with vane geometry in
temperature of 20°C. To highlight the influence of bentonite and
superplasticizer on the rheological behavior of grout cement, various
flow tests in a range of shear rate from 0 to 200 s-1 were observed.
Cement grout showed a non-Newtonian viscosity behavior at all
concentrations of bentonite. Three parameter model Herschel-
Bulkley was chosen for fitting of experimental data. Based on the
values of correlation coefficients of the estimated parameters, The
Herschel-Bulkley law model well described the rheological behavior
of the grouts. Test results showed that the dosage of bentonite
increases the viscosity and yield stress of the system and introduces
more thixotropy. While the addition of both bentonite and
superplasticizer with cement grout improve significantly the fluidity
and reduced the yield stress due to the action of dispersion of SP.
Abstract: The purpose of this paper is to identify the main
challenges faced by companies in the timber construction sector and
to provide improvement opportunities that can be implemented on a
short-, medium- and long-term basis. To identify the challenges and
propose actions for each company a literature review and a multiple
case research were conducted using the Quick Scan Audit
Methodology. Finally, the findings and outcomes are compared with
each other to support companies in the timer construction sector
when implementing and restructuring their day-to-day activities.
Abstract: This study examined coaching leadership traits as preferred by athletes of universities and colleges of education located in Lagos State, South West Nigeria. Athletes from two universities (n=99) and two colleges of education (n=92) were involved as study sample. The Leadership Trait Preference Questionnaire (LTPQ) was used to measure athletes’ preferences. Mean and Spearman rank order statistics were used to analyze collected data. Results showed that the traits of friendliness and happiness, sense of humour and cheerfulness, and cooperation were most preferred irrespective of type of institution. College of education athletes were found to have higher mean preferences (M=34.54; SD=9.42) of leadership traits than their university counterparts (M=33.64; SD=9.46). A significantly strong relationship (rho=.81;*p
Abstract: Implementing significant advantages in the supply of self-compacting concrete (SCC) is necessary because of the, negative features of SCC. Examples of these features are the ductility problem along with the very high cost of its constituted materials. Silica fume with steel fiber can fix this matter by improving the ductility and decreasing the total cost of SCC by varying the cement ingredients. Many different researchers have found that there have not been enough research carried out on the steel fiber-reinforced self-compacting concrete (SFRSCC) produced with silica fume. This paper inspects both the fresh and the mechanical properties of SFRSCC with silica fume, the fresh qualities where slump flow, slump T50 and V- funnel. While, the mechanical characteristics were the compressive strength, ultrasound pulse velocity (UPV) and elastic modulus of the concrete samples. The experimental results have proven that steel fiber can enhance the mechanical features. In addition, the silica fume within the entire hybrid mix may possibly adapt the fiber dispersion and strengthen deficits due to the fibers. It could also improve the strength plus the bond between the fiber and the matrix with a dense calcium silicate-hydrate gel in SFRSCC. The concluded result was predicted using linear mathematical models and was found to be in great agreement with the experimental results.
Abstract: Information and Communications Technologies (ICT) has been integrated in education in many developing and developed countries alike, but the use of ICT in Tanzanian schools is dismal. Many Tanzanian secondary schools have no computers. The few schools with computers use them primarily for secretarial services and computer literacy training. The Tanzanian education system at other levels like secondary school level has to undergo substantial transformation, underscored by the growing application of new information and communication technology. This paper presents the e-readiness survey result from secondary schools in Tanzania. The paper also suggests how Tanzania can make use of the few present ICT resources to support and improve teaching and learning functions to improve performance and acquisition of knowledge by using e-Learning Management System (e-LMS).
Abstract: A Simultaneous Multithreading (SMT) Processor is
capable of executing instructions from multiple threads in the same
cycle. SMT in fact was introduced as a powerful architecture to
superscalar to increase the throughput of the processor.
Simultaneous Multithreading is a technique that permits multiple
instructions from multiple independent applications or threads to
compete limited resources each cycle. While the fetch unit has been
identified as one of the major bottlenecks of SMT architecture, several
fetch schemes were proposed by prior works to enhance the fetching
efficiency and overall performance.
In this paper, we propose a novel fetch policy called queue situation
identifier (QSI) which counts some kind of long latency instructions of
each thread each cycle then properly selects which threads to fetch
next cycle. Simulation results show that in best case our fetch policy
can achieve 30% on speedup and also can reduce the data cache level 1
miss rate.
Abstract: The influence of lactulose and inulin on rheological
properties of fermented milk during storage was studied.Pasteurized
milk, freeze-dried starter culture Bb-12 (Bifidobacterium lactis, Chr.
Hansen, Denmark), inulin – RAFTILINE®HP (ORAFI, Belgium) and
syrup of lactulose (Duphalac®, the Netherlands) were used for
experiments. The fermentation process was realized at 37 oC for 16
hours and the storage of products was provided at 4 oC for 7 days.
Measurements were carried out by BROOKFIELD standard methods
and the flow curves were described by Herschel-Bulkley model.
The results of dispersion analysis have shown that both the
concentration of prebiotics (p=0.04
Abstract: Producing companies aspire to high delivery
availability despite appearing disruptions. To ensure high delivery
availability safety stocksare required. Howeversafety stock leads to
additional capital commitment and compensates disruptions instead
of solving the reasons.The intention is to increase the stability in
production by configuring the production planning and control
systematically. Thus the safety stock can be reduced. The largest
proportion of inventory in producing companies is caused by batch
inventory, schedule deviations and variability of demand rates.These
reasons for high inventory levels can be reduced by configuring the
production planning and control specifically. Hence the inventory
level can be reduced. This is enabled by synchronizing the lot size
straightening the demand as well as optimizing the releasing order,
sequencing and capacity control.
Abstract: In this paper, we propose a new modular approach called neuroglial consisting of two neural networks slow and fast which emulates a biological reality recently discovered. The implementation is based on complex multi-time scale systems; validation is performed on the model of the asynchronous machine. We applied the geometric approach based on the Gerschgorin circles for the decoupling of fast and slow variables, and the method of singular perturbations for the development of reductions models.
This new architecture allows for smaller networks with less complexity and better performance in terms of mean square error and convergence than the single network model.
Abstract: This paper made an attempt to investigate the problem associated with enhancement of emulsions of light crude oil-water recovery in an oil field of Algerian Sahara. Measurements were taken through experiments using RheoStress (RS600). Factors such as shear rate, temperature and light oil concentration on the viscosity behavior were considered. Experimental measurements were performed in terms of shear stress–shear rate, yield stress and flow index on mixture of light crude oil–water. The rheological behavior of emulsion showed Non-Newtonian shear thinning behavior (Herschel-Bulkley). The experiments done in the laboratory showed the stability of some water in light crude oil emulsions form during consolidate oil recovery process. To break the emulsion using additives may involve higher cost and could be very expensive. Therefore, further research should be directed to find solution of these problems that have been encountered.
Abstract: This paper describes interconnection between
technical and economical making decision. The reason of this dealing
could be different: poor technical condition, change of substation
(electrical network) regime, power transformer owner budget deficit
and increasing of tariff on electricity. Establishing of recommended
practice as well as to give general advice and guidance in economical
sector, testing, diagnostic power transformers to establish its
conditions, identify problems and provide potential remedies.
Abstract: Our results showed that for the growth of qualitative
seedling and vegetative raw material of ðó. marschallianus Willd. and
T. serphyllum L. it is more profitable to use the in vitro and
hydroponics combined method. In in vitro culture it is possible to do
micro-propagation whole year with 98-99% rhizogenesis. 30000
micro-plants were obtained from one explant during 9 months.
Hydroponic conditions provide the necessary microclimate for
microplants where the survival rate without acclimatization was
93.3%. The essential oil content in hydroponic dry herb of both
species in vegetative and blossom phase was 1.3% whereas in wild
plants it was 1.2%, the content of extractive substances and vitamin
C also exceeded wild plants. Our biochemical and radiochemical
investigations indicated that the medicinal raw materials obtained
from hydroponic and wild plants of Thymus species correspond to
the demands of SPh XI, and the content of artificial radionuclides
does not exceed the MACL.
Abstract: The tracing methods determine the contribution the
power system sources have in their supplying. The methods can be used
to assess the transmission prices, but also to recover the transmission
fixed cost. In this paper is presented the influence of the modification of
commons structure has on the specific price of transfer. The operator
must make use of a few basic principles about allocation. Most
tracing methods are based on the proportional sharing principle. In this
paper Kirschen method is used. In order to illustrate this method, the 25-
bus test system is used, elaborated within the Electrical Power
Engineering Department, from Timisoara, Romania.
Abstract: This paper presents a threshold voltage model of pocket implanted sub-100 nm n-MOSFETs incorporating the drain and substrate bias effects using two linear pocket profiles. Two linear equations are used to simulate the pocket profiles along the channel at the surface from the source and drain edges towards the center of the n-MOSFET. Then the effective doping concentration is derived and is used in the threshold voltage equation that is obtained by solving the Poisson-s equation in the depletion region at the surface. Simulated threshold voltages for various gate lengths fit well with the experimental data already published in the literature. The simulated result is compared with the two other pocket profiles used to derive the threshold voltage models of n-MOSFETs. The comparison shows that the linear model has a simple compact form that can be utilized to study and characterize the pocket implanted advanced ULSI devices.
Abstract: The tracing methods determine the contribution the
power system sources have in their supplying. These methods can be
used to assess the transmission prices, but also to recover the
transmission fixed cost. In this paper is presented the influence of the
modification of commons structure has on the specific price of transfer
and on active power losses. The authors propose a power losses
allocation method, based on Kirschen-s method. The system operator
must make use of a few basic principles about allocation. The only
necessary information is the power flows on system branches and the
modifications applied to power system buses. In order to illustrate this
method, the 25-bus test system is used, elaborated within the Electrical
Power Engineering Department, from Timisoara, Romania.
Abstract: The purpose of this paper is to summarize the
following protection of scouring countermeasures by using
Bentonite-Enhanced Sand (BES) mixtures. The concept of
underground improvement is being used in this study to reduce the
void of the sand. The sand bentonite mixture was used to bond the
ground soil conditions surrounding the pile of integral bridge. The
right composition of sand bentonite mixture was proposed based on
previous findings. The swelling effect of bentonite also was
investigated to ensure there is no adverse impact to the structure of
the integral bridge. ScourScour, another name for severe erosion,
occurs when the erosive capacity of water resulting from natural and
manmade events exceeds the ability of earth materials to resist its
effects. According to AASHTO LRFD Specifications (Section
C3.7.5), scour is the most common reason for the collapse of
highway bridges in the United States
Abstract: The purpose of this research is to develop and apply the
RSCMAC to enhance the dynamic accuracy of Global Positioning
System (GPS). GPS devices provide services of accurate positioning,
speed detection and highly precise time standard for over 98% area on
the earth. The overall operation of Global Positioning System includes
24 GPS satellites in space; signal transmission that includes 2
frequency carrier waves (Link 1 and Link 2) and 2 sets random
telegraphic codes (C/A code and P code), on-earth monitoring stations
or client GPS receivers. Only 4 satellites utilization, the client position
and its elevation can be detected rapidly. The more receivable
satellites, the more accurate position can be decoded. Currently, the
standard positioning accuracy of the simplified GPS receiver is greatly
increased, but due to affected by the error of satellite clock, the
troposphere delay and the ionosphere delay, current measurement
accuracy is in the level of 5~15m. In increasing the dynamic GPS
positioning accuracy, most researchers mainly use inertial navigation
system (INS) and installation of other sensors or maps for the
assistance. This research utilizes the RSCMAC advantages of fast
learning, learning convergence assurance, solving capability of
time-related dynamic system problems with the static positioning
calibration structure to improve and increase the GPS dynamic
accuracy. The increasing of GPS dynamic positioning accuracy can be
achieved by using RSCMAC system with GPS receivers collecting
dynamic error data for the error prediction and follows by using the
predicted error to correct the GPS dynamic positioning data. The
ultimate purpose of this research is to improve the dynamic positioning
error of cheap GPS receivers and the economic benefits will be
enhanced while the accuracy is increased.
Abstract: The objective of this paper was to designing a
ventilation system to enhance the performance of roof solar collector
(RSC) for reducing heat accumulation inside the house. The RSC has
1.8 m2 surface area made of CPAC monier roof tiles on the upper part
and gypsum board on the lower part. The space between CPAC
monier and gypsum board was fixed at 14 cm.
Ventilation system of modified roof solar collector (modified
RSC) consists of 9 tubes of 0.15m diameter and installed in the
lower part of RSC. Experimental result showed that the temperature
of the room, and attic temperature. The average temperature
reduction of room of house used modified RSC is about 2oC. and the
percentage of room temperature reduction varied between 0 to 10%.
Therefore, modified RSC is an interesting option in the sense that it
promotes solar energy and conserve energy.
Abstract: In a wind power generator using doubly fed induction
generator (DFIG), the three-phase pulse width modulation (PWM)
voltage source converter (VSC) is used as grid side converter (GSC)
and rotor side converter (RSC). The standard linear control laws
proposed for GSC provides not only instablity against comparatively
large-signal disturbances, but also the problem of stability due to
uncertainty of load and variations in parameters. In this paper, a
nonlinear controller is designed for grid side converter (GSC) of a
DFIG for wind power application. The nonlinear controller is
designed based on the input-output feedback linearization control
method. The resulting closed-loop system ensures a sufficient
stability region, make robust to variations in circuit parameters and
also exhibits good transient response. Computer simulations and
experimental results are presented to confirm the effectiveness of the
proposed control strategy.