Abstract: Exploration and exploitation capabilities are both
important within Operations as means for improvement when
managed separately, and for establishing dynamic improvement
capabilities when combined in balance. However, it is unclear what
exploration and exploitation capabilities imply in improvement and
development work within an Operations context. So, in order to
better understand how to develop exploration and exploitation
capabilities within Operations, the main characteristics of these
constructs needs to be identified and further understood. Thus, the
objective of this research is to increase the understanding about
exploitation and exploration characteristics, to concretize what they
translates to within the context of improvement and development
work in an Operations unit, and to identify practical challenges. A
literature review and a case study are presented. In the literature
review, different interpretations of exploration and exploitation are
portrayed, key characteristics have been identified, and a deepened
understanding of exploration and exploitation characteristics is
described. The case in the study is an Operations unit, and the aim is
to explore to what extent and in what ways exploration and
exploitation activities are part of the improvement structures and
processes. The contribution includes an identification of key
characteristics of exploitation and exploration, as well as an
interpretation of the constructs. Further, some practical challenges are
identified. For instance, exploration activities tend to be given low
priority, both in daily work as in the manufacturing strategy. Also,
the overall understanding about the concepts of exploitation and
exploration (or any similar aspect of dynamic improvement
capabilities) is very low.
Abstract: The paper develops a Non-Linear Model Predictive
Control (NMPC) of water quality in Drinking Water Distribution
Systems (DWDS) based on the advanced non-linear quality dynamics
model including disinfections by-products (DBPs). A special attention
is paid to the analysis of an impact of the flow trajectories prescribed
by an upper control level of the recently developed two-time scale
architecture of an integrated quality and quantity control in DWDS.
The new quality controller is to operate within this architecture in the
fast time scale as the lower level quality controller. The controller
performance is validated by a comprehensive simulation study based
on an example case study DWDS.
Abstract: Knowledge of bone mechanical properties is important
for bone substitutes design and fabrication, and more efficient
prostheses development. The aim of this study is to characterize the
viscoelastic behavior of bone specimens, through stress relaxation
and fatigue tests performed to trabecular bone samples from bovine
femoral heads. Relaxation tests consisted on preloading the samples
at five different magnitudes and evaluate them for 1020 seconds,
adjusting the results to a KWW mathematical model. Fatigue tests
consisted of 700 load cycles and analyze their status at the end of the
tests. As a conclusion we have that between relaxation stress and
each preload there is linear relation and for samples with initial
Young´s modulus greater than 1.5 GPa showed no effects due fatigue
test loading cycles.
Abstract: In the immunologic sense, clinical infection is a state
of failure of the immune system to combat the pathogenic weapon of
the bacteria invading the host. A motile gram negative vibroid
organism associated with marked mono and poly nuclear cell
responses was traced during the examination of a clinical material
from an infected common carp Cyprinus carpio. On primary plate
culture, growth was shown to be pure, dense population of an
Aeromonas-like colony morphotype. The pure isolate was found to
be; Aerobic, facultatively anaerobic, non-halophilic, grew at 0C, and
37C, oxidase positive utilizes glucose through fermentative pathway,
resist 0/129 and novobiocin, produces alanine and lysine
decarboxylases but non-producing ornithine dehydrolases. Tests for
the in vitro determinants of pathogenicity has shown to be; Betahaemolytic
onto blood agar, gelatinase, casienase and amylase
producer. Three in vivo determinants of pathogenicity were tested as,
the lethal dose fifty, the pathogenesis and pathogenicity. It was
evident that 0.1 milliliter of the causal bacterial cell suspension of a
density 1 x 107 CFU/ml injected intramuscularly into an average of
100gms fish toke five days incubation period, then at the day six
morbidity and mortality were initiated. LD50 was recorded at the day
12 post-infection. Use of an LD50 doses to study the pathogenicity,
reveals mononuclear and polynuclear cell responses, on examining
the stained direct films of the clinical materials from the
experimentally infected fish. Re-isolation tests confirm that the reisolant
is same. The course of the infection in natural case was shown
manifestation of; skin ulceration, haemorrhage and descaling. On
evisceration, the internal organs were shown; congestion in the
intestines, spleen and, air sacs. The induced infection showed a
milder form of these manifestations. The grading of the virulence of
this organism was virulent causing chronic course of infections as
indicated from the pathogenesis and pathogenicity studies. Thus the
infectious bacteria were consistent with Aeromonas hydrophila, and
the infection was chronic.
Abstract: Biomass briquette gasification is regarded as a
promising route for efficient briquette use in energy generation, fuels
and other useful chemicals. However, previous research has been
focused on briquette gasification in fixed bed gasifiers such as
updraft and downdraft gasifiers. Fluidised bed gasifier has the
potential to be effectively sized to medium or large scale. This study
investigated the use of fuel briquettes produced from blends of rice
husks and corn cobs biomass, in a bubbling fluidised bed gasifier.
The study adopted a combination of numerical equations and Aspen
Plus simulation software, to predict the product gas (syngas)
composition base on briquette density and biomass composition
(blend ratio of rice husks to corn cobs). The Aspen Plus model was
based on an experimentally validated model from the literature. The
results based on a briquette size 32 mm diameter and relaxed density
range of 500 to 650kg/m3, indicated that fluidisation air required in
the gasifier increased with increase in briquette density, and the
fluidisation air showed to be the controlling factor compared with the
actual air required for gasification of the biomass briquettes. The
mass flowrate of CO2 in the predicted syngas composition increased
with an increase in air flow, in the gasifier, while CO decreased and
H2 was almost constant. The ratio of H2 to CO for various blends of
rice husks and corn cobs did not significantly change at the designed
process air, but a significant difference of 1.0 was observed between
10/90 and 90/10 % blend of rice husks and corn cobs.
Abstract: This study was aimed to investigate the machining
stability of a spindle tool with different preloaded amount. To this end,
the vibration tests were conducted on the spindle unit with different
preload to assess the dynamic characteristics and machining stability
of the milling machine. Current results demonstrate that the tool tip
frequency response characteristics and the machining stabilities in X
and Y direction are affected to change due to the different preload of
spindle bearings. As found from the results, a high preloaded spindle
tool shows higher limited cutting depth at mid position, while a spindle
with low preload shows a higher limited depth. This indicates that the
machining stability of a milling machine is affected to vary by the
spindle unit when it was assembled with different bearing preload.
Abstract: The research was conducted in order to determine the
organizational socialization levels of nurses working in hospitals in
the form of a descriptive study.
The research population was composed of nurses employed in
public and private sector hospitals in the province of Konya with 0-3
years of professional experience in the hospitals (N=1200); and the
sample was composed of 495 nurses that accepted to take part in the
study voluntarily. Statistical evaluation of data was conducted in
SPSS.16 software.
The results of the study revealed that the total score taken by
nurses at the organizational socialization scale was 262.95; and this
was close to the maximum score. Particularly the departmental
socialization sub-dimension proved to be higher in comparison to the
other two dimensions (organization socialization and task
socialization). Statistically meaningful differences were found in the
levels of organization socialization in relation to the status of
organizational orientation training, level of education and age group.
Abstract: More than 3000 plants of notable phyto-therapeutic
value grow in South Africa; these include Cissampelos capensis,
commonly known in Afrikaans as dawidjie or dawidjiewortel. C.
capensis is the most significant and popular medicinal plant used by
the Khoisan as well as other rural groups in the Western region of
South Africa. Its rhizomes are traditionally used to treat male fertility
problems. Yet, no studies have investigated the effects of this plant or
its extracts on human spermatozoa. Therefore, this study aimed at
investigating the effects of C. capensis rhizome extract (CRE)
fractions on ejaculated human spermatozoa in vitro. Spermatozoa
from a total of 77 semen samples were washed with human tubular
fluid medium supplemented with bovine serum albumin (HTF-BSA)
and incubated for 2 hours with 20 μg/ml progesterone (P4) followed
by incubation with different concentrations (0, 0.05, 0.5, 5, 50, 200
μg/ml) of fractionated CRE (F1=0% MeOH, F2=30% MeOH,
F3=60% MeOH and F4=100% MeOH) for 1.5 hours at 37°C. A
sample without addition of CRE fractions served as control. Samples
were analyzed for sperm motility, reactive oxygen species (ROS),
DNA-fragmentation, acrosome reaction and capacitation. Results
showed that F1 resulted in significantly higher values for ROS,
capacitation and hyper-activation compared to F2, F3, and F4 with
P4-stimulated samples generally having higher values. No significant
effect was found for the other parameters. In conclusion, alkaloids
present in F1 of CRE appear to have triggered sperm intrinsic ROS
production leading to sperm capacitation and acrosome reaction
induced by P4.
Abstract: It is the worldwide problem that the recycled PVB is
not recycled and it is wildly stored in landfills. However, PVB has
similar chemical properties such as PVC. Moreover, both of these
polymers are plasticized. Therefore, the study of thermal properties
of plasticized PVC and the recycled PVB obtained by recycling of
windshields is carried out. This work has done in order to find nondegradable
processing conditions applicable for both polymers.
Tested PVC contained 38% of plasticizer diisononyl phthalate
(DINP) and PVB was plasticized with 28% of triethylene glycol,
bis(2-ethylhexanoate) (3GO). The thermal and thermo-oxidative
decomposition of both vinyl polymers are compared by calorimetric
analysis and by tensile strength analysis.
Abstract: Steady three-dimensional and two free surface waves
generated by moving bodies are presented, the flow problem to be
simulated is rich in complexity and poses many modeling challenges
because of the existence of breaking waves around the ship hull, and
because of the interaction of the two-phase flow with the turbulent
boundary layer. The results of several simulations are reported. The
first study was performed for NACA0012 of hydrofoil with different
meshes, this section is analyzed at h/c= 1, 0345 for 2D. In the second
simulation a mathematically defined Wigley hull form is used to
investigate the application of a commercial CFD code in prediction of
the total resistance and its components from tangential and normal
forces on the hull wetted surface. The computed resistance and wave
profiles are used to estimate the coefficient of the total resistance for
Wigley hull advancing in calm water under steady conditions. The
commercial CFD software FLUENT version 12 is used for the
computations in the present study. The calculated grid is established
using the code computer GAMBIT 2.3.26. The shear stress k-ωSST
model is used for turbulence modeling and the volume of fluid
technique is employed to simulate the free-surface motion. The
second order upwind scheme is used for discretizing the convection
terms in the momentum transport equations, the Modified HRIC
scheme for VOF discretization. The results obtained compare well
with the experimental data.
Abstract: Copper (I) oxide microparticles with the morphology
of cubic and hollow sphere were synthesized with the assistance of
surfactant as the shape controller. Both particles were then subjected
to study the catalytic activity and observed the results of shape effects
of catalysts on rate of catalytic reaction. The decolorizing reaction of
crystal violet and sodium hydroxide was chosen and measured the
decreasing of reactant with respect to times using spectrophotometer.
The result revealed that morphology of crystal had no effect on the
catalytic activity for crystal violet reaction but contributed to total
surface area predominantly.
Abstract: Whey is the lactose rich by-product of the dairy
industry, having good amount of nutrient reservoir. Most abundant
nutrients are lactose, soluble proteins, lipids and mineral salts.
Disposing of whey by most of milk plants which do not have proper
pre-treatment system is the major issue. As a result of which, there
can be significant loss of potential food and energy source. Thus,
whey has been explored as the substrate for the synthesis of different
value added products such as enzymes. β-galactosidase is one of the
important enzymes and has become the major focus of research due
to its ability to catalyze both hydrolytic as well as
transgalactosylation reaction simultaneously. The enzyme is widely
used in dairy industry as it catalyzes the transformation of lactose to
glucose and galactose, making it suitable for the lactose intolerant
people. The enzyme is intracellular in both bacteria and yeast,
whereas for molds, it has an extracellular location. The present work
was carried to utilize the whey for the production of β-galactosidase
enzyme using both yeast and fungal cultures. The yeast isolate
Kluyveromyces marxianus WIG2 and various fungal strains have
been used in the present study. Different disruption techniques have
also been investigated for the extraction of the enzyme produced
intracellularly from yeast cells. Among the different methods tested
for the disruption of yeast cells, SDS-chloroform showed the
maximum β-galactosidase activity. In case of the tested fungal
cultures, Aureobasidium pullulans NCIM 1050 was observed to be
the maximum extracellular enzyme producer.
Abstract: An investigation of adaptable winglets for enhancing
morphing aircraft performance is described in this paper. The
concepts investigated consist of various winglet configurations
fundamentally centered on a baseline swept wing. The impetus for
the work was to identify and optimize winglets to enhance the
aerodynamic efficiency of a morphing aircraft. All computations
were performed with Athena Vortex Lattice modelling with varying
degrees of twist and cant angle considered. The results from this
work indicate that if adaptable winglets were employed on aircraft’s
improvements in aircraft performance could be achieved.
Abstract: Nowadays, the rapid development of CAD systems’
programming environments results in the creation of multiple
downstream applications, which are developed and becoming
increasingly available. CAD based manufacturing simulations is
gradually following the same trend. Drilling is the most popular holemaking
process used in a variety of industries. A specially built piece
of software that deals with the drilling kinematics is presented. The
cutting forces are calculated based on the tool geometry, the cutting
conditions and the tool/work-piece materials. The results are verified
by experimental work. Finally, the response surface methodology
(RSM) is applied and mathematical models of the total thrust force
and the thrust force developed because of the main cutting edges are
proposed.
Abstract: Metal thin-walled members have been widely used in
building industry. Usually they are utilized as purlins, girts or ceiling
beams. Due to slenderness of thin-walled cross-sections these
structural members are prone to stability problems (e.g. flexural
buckling, lateral torsional buckling). If buckling is not
constructionally prevented their resistance is limited by buckling
strength. In practice planar members of roof or wall cladding can be
attached to thin-walled members. These elements reduce
displacement of thin-walled members and therefore increase their
buckling strength. If this effect is taken into static assessment more
economical sections of thin-walled members might be utilized and
certain savings of material might be achieved. This paper focuses on
problem of determination of critical load of steel thin-walled beams
with lateral continuous restraint which is crucial for lateral torsional
buckling assessment.
Abstract: Aluminium matrix composites with alumina
reinforcements give superior mechanical & physical properties. Their
applications in several fields like automobile, aerospace, defense,
sports, electronics, bio-medical and other industrial purposes are
becoming essential for the last several decades. In the present work,
fabrication of hybrid composite was done by Stir casting technique
using Al 6061 as a matrix with alumina and silicon carbide (SiC) as
reinforcement materials. The weight percentage of alumina is varied
from 2 to 4% and the silicon carbide weight percentage is maintained
constant at 2%. Hardness and wear tests are performed in the as cast
and heat treated conditions. Age hardening treatment was performed
on the specimen with solutionizing at 550°C, aging at two
temperatures (150 and 200°C) for different time durations. Hardness
distribution curves are drawn and peak hardness values are recorded.
Hardness increase was very sensitive with respect to the decrease in
aging temperature. There was an improvement in wear resistance of
the peak aged material when aged at lower temperature. Also
increase in weight percent of alumina, increases wear resistance at
lower temperature but opposite behavior was seen when aged at
higher temperature.
Abstract: This paper addresses a cutting edge method of
business demand forecasting, based on an empirical probability
function when the historical behavior of the data is random.
Additionally, it presents error determination based on the numerical
method technique ‘propagation of errors.’ The methodology was
conducted characterization and process diagnostics demand planning
as part of the production management, then new ways to predict its
value through techniques of probability and to calculate their mistake
investigated, it was tools used numerical methods. All this based on
the behavior of the data. This analysis was determined considering
the specific business circumstances of a company in the sector of
communications, located in the city of Bogota, Colombia. In
conclusion, using this application it was possible to obtain the
adequate stock of the products required by the company to provide its
services, helping the company reduce its service time, increase the
client satisfaction rate, reduce stock which has not been in rotation
for a long time, code its inventory, and plan reorder points for the
replenishment of stock.
Abstract: The present study was aimed to examine the structure
of children’s adaptation during school transition and to identify a
commonality and dissimilarity at the elementary and junior high
school. 1,983 students in the 6th grade and 2,051 students in the 7th
grade were extracted by stratified two-stage random sampling and
completed the ASSESS that evaluated the school adaptation from the
view point of ‘general satisfaction’, ‘teachers’ support’, ‘friends’
support’, ‘anti-bullying relationship’, ‘prosocial skills’, and ‘academic
adaptation’. The 7th graders tend to be worse adaptation than the 6th
graders. A structural equation modeling showed the goodness of fit for
each grades. Both models were very similar but the 7th graders’ model
showed a lower coefficient at the pass from ‘teachers’ support’ to
‘friends’ support’. The role of ‘teachers’ support’ was decreased to
keep a good relation in junior high school. We also discussed how we
provide a continuous assistance for prevention of the 7th graders’ gap.
Abstract: In order to address construction project requirements
and specifications, scholars and practitioners need to establish
taxonomy according to a scheme that best fits their need. While
existing characterization methods are continuously being improved,
new ones are devised to cover project properties which have not been
previously addressed. One such method, the Project Definition Rating
Index (PDRI), has received limited consideration strictly as a
classification scheme. Developed by the Construction Industry
Institute (CII) in 1996, the PDRI has been refined over the last two
decades as a method for evaluating a project's scope definition
completeness during front-end planning (FEP). The main
contribution of this study is a review of practical project classification
methods, and a discussion of how PDRI can be used to classify
projects based on their readiness in the FEP phase. The proposed
model has been applied to 59 construction projects in Ontario, and
the results are discussed.
Abstract: This paper participates in giving new vision and
explains the learning and acquisition processes of English language
by analyzing a certain context. Five important factors in English
language acquisition and learning are discussed and suitable solutions
are provided. The factors are compared with the learners' linguistic
background at Bisha College of Technology BCT attempting to link
the issues faced by students and the research done on similar
situations. These factors are phonology, age of acquisition,
motivation, psychology and courses of English. These factors are
very important; because they interfere and affect specific learning
processes at BCT context and general English learning situations.