Abstract: Goat dairy products are gaining popularity worldwide. In developing countries, but also in many marginal regions of the Mediterranean area, goats represent a great part of the economy and ensure food security. In fact, these small ruminants are able to convert efficiently poor weedy plants and small trees into traditional products of high nutritional quality, showing great resilience to different climatic and environmental conditions. In developed countries, goat milk is appreciated for the presence of health-promoting compounds, bioactive compounds such as conjugated linoleic acids, oligosaccharides, sphingolipids and polyammines. This paper focuses on the recent advances in literature on the nutritional properties of goat milk and on innovative techniques to improve its quality as to become a promising functional food. The environmental sustainability of different methodologies of production has also been examined. Goat milk is valued today as a food of high nutritional value and functional properties as well as small environmental footprint. It is widely consumed in many countries due to high nutritional value, lower allergenic potential, and better digestibility when compared to bovine milk, that makes this product suitable for infants, elderly or sensitive patients. The main differences in chemical composition between a cow and goat milk rely on fat globules that in goat milk are smaller and in fatty acids that present a smaller chain length, while protein, fat, and lactose concentration are comparable. Milk nutritional properties have demonstrated to be strongly influenced by animal diet, genotype, and welfare, but also by season and production systems. Furthermore, there is a growing interest in the dairy industry in goat milk for its relatively high concentration of prebiotics and a good amount of probiotics, which have recently gained importance for their therapeutic potential. Therefore, goat milk is studied as a promising matrix to develop innovative functional foods. In addition to the economic and nutritional value, goat milk is considered a sustainable product for its small environmental footprint, as they require relatively little water and land, and less medical treatments, compared to cow, these characteristics make its production naturally vocated to organic farming. Organic goat milk production has becoming more and more interesting both for farmers and consumers as it can answer to several concerns like environment protection, animal welfare and economical sustainment of rural populations living in marginal lands. These evidences make goat milk an ancient food with novel properties and advantages to be valorized and exploited.
Abstract: The substantial development of the construction
industry has forced the cement industry, its major support, to focus
on achieving maximum productivity to meet the growing demand for
this material. This means that the reliability of a cement production
system needs to be at the highest level that can be achieved by good
maintenance. This paper studies the extent to which the
implementation of RCM is needed as a strategy for increasing the
reliability of the production systems component can be increased,
thus ensuring continuous productivity. In a case study of four Libyan
cement factories, 80 employees were surveyed and 12 top and middle
managers interviewed. It is evident that these factories usually
breakdown more often than once per month which has led to a
decline in productivity. In many times they cannot achieve the
minimum level of production amount. This has resulted from the
poor reliability of their production systems as a result of poor or
insufficient maintenance. It has been found that most of the factories’
employees misunderstand maintenance and its importance. The main
cause of this problem is the lack of qualified and trained staff, but in
addition it has been found that most employees are not found to be
motivated as a result of a lack of management support and interest. In
response to these findings, it has been suggested that the RCM
strategy should be implemented in the four factories. The results
show the importance of the development of maintenance strategies
through the implementation of RCM in these factories. The purpose
of it would be to overcome the problems that could secure the
reliability of the production systems. This study could be a useful
source of information for academic researchers and the industrial
organizations which are still experiencing problems in maintenance
practices.
Abstract: Negative pressure phenomenon appears in many
thermodynamic, geophysical and biophysical processes in the Nature
and technological systems. For more than 100 years of the laboratory
researches beginning from F. M. Donny’s tests, the great values of
negative pressure have been achieved. But this phenomenon has not
been practically applied, being only a nice lab toy due to the special
demands for the purity and homogeneity of the liquids for its
appearance. The possibility of creation of direct wave of negative
pressure in real heterogeneous liquid systems was confirmed
experimentally under the certain kinetic and hydraulic conditions.
The negative pressure can be considered as the factor of both useful
and destroying energies. The new approach to generation of the
negative pressure waves in impure, unclean fluids has allowed the
creation of principally new energy saving technologies and
installations to increase the effectiveness and efficiency of different
production processes. It was proved that the negative pressure is one
of the main factors causing hard troubles in some technological and
natural processes. Received results emphasize the necessity to take
into account the role of the negative pressure as an energy factor in
evaluation of many transient thermohydrodynamic processes in the
Nature and production systems.
Abstract: Just-In-Time (JIT) is a lean manufacturing tool, which provides the benefits of efficiency, and of minimizing unnecessary costs for many organisations. However, the risks arising from these benefits have been disregarded. These risks impact on system processes disrupting the whole supply chain. This paper proposes an inventory model that can simultaneously reduce costs and risks in JIT systems. This model is developed to ascertain an optimal ordering strategy for procuring raw materials by using regular multi-external and local backup suppliers to reduce the total cost of the products, and at the same time to reduce the risks arising from this cost reduction within production systems. Some results that will be illustrated in the second part of this paper are presented.
Abstract: In today-s competitive market, most companies
develop manufacturing systems that can help in cost reduction and
maximum quality. Human issues are an important part of
manufacturing systems, yet most companies ignore their effects on
production performance. This paper aims to developing an integrated
workforce planning system that incorporates the human being.
Therefore, a multi-objective mixed integer nonlinear programming
model is developed to determine the amount of hiring, firing,
training, overtime for each worker type. This paper considers a
workforce planning model including human aspects such as skills,
training, workers- personalities, capacity, motivation, and learning
rates. This model helps to minimize the hiring, firing, training and
overtime costs, and maximize the workers- performance. The results
indicate that the workers- differences should be considered in
workforce scheduling to generate realistic plans with minimum costs.
This paper also investigates the effects of human learning rates on the
performance of the production systems.
Abstract: As German companies roll out their standardized
production systems to offshore manufacturing plants, they face the
challenge of implementing them in different cultural environments.
Studies show that the local adaptation is one of the key factors for a
successful implementation. Thus the question arises of where the line
between standardization and adaptation can be drawn. To answer
this question the influence of culture on production systems is
analysed in this paper. The culturally contingent components of
production systems are identified. Also the contingency factors are
classified according to their impact on the necessary adaptation
changes and implementation effort. Culturally specific decision
making, coordination, communication and motivation patterns
require one-time changes in organizational and process design. The
attitude towards rules requires more intense coaching and controlling.
Lastly a framework is developed to depict standardization and
adaption needs when transplanting production systems into different
cultural environments.
Abstract: Modern highly automated production systems faces
problems of reliability. Machine function reliability results in
changes of productivity rate and efficiency use of expensive
industrial facilities. Predicting of reliability has become an important
research and involves complex mathematical methods and
calculation. The reliability of high productivity technological
automatic machines that consists of complex mechanical, electrical
and electronic components is important. The failure of these units
results in major economic losses of production systems. The
reliability of transport and feeding systems for automatic
technological machines is also important, because failure of transport
leads to stops of technological machines. This paper presents
reliability engineering on the feeding system and its components for
transporting a complex shape parts to automatic machines. It also
discusses about the calculation of the reliability parameters of the
feeding unit by applying the probability theory. Equations produced
for calculating the limits of the geometrical sizes of feeders and the
probability of sticking the transported parts into the chute represents
the reliability of feeders as a function of its geometrical parameters.
Abstract: Fair share is one of the scheduling objectives supported on many production systems. However, fair share has been shown to cause performance problems for some users, especially the users with difficult jobs. This work is focusing on extending goaloriented parallel computer job scheduling policies to cover the fair share objective. Goal-oriented parallel computer job scheduling policies have been shown to achieve good scheduling performances when conflicting objectives are required. Goal-oriented policies achieve such good performance by using anytime combinatorial search techniques to find a good compromised schedule within a time limit. The experimental results show that the proposed goal-oriented parallel computer job scheduling policy (namely Tradeofffs( Tw:avgX)) achieves good scheduling performances and also provides good fair share performance.
Abstract: CONWIP (constant work-in-process) as a pull
production system have been widely studied by researchers to date.
The CONWIP pull production system is an alternative to pure push
and pure pull production systems. It lowers and controls inventory
levels which make the throughput better, reduces production lead
time, delivery reliability and utilization of work. In this article a
CONWIP pull production system was simulated. It was simulated
push and pull planning system. To compare these systems via a
production planning system (PPS) game were adjusted parameters of
each production planning system. The main target was to reduce the
total WIP and achieve throughput and delivery reliability to
minimum values. Data was recorded and evaluated. A future state
was made for real production of plastic components and the setup of
the two indicators with CONWIP pull production system which can
greatly help the company to be more competitive on the market.
Abstract: This paper implements the inventory model developed in the first part of this paper in a simplified problem to simultaneously reduce costs and risks in JIT systems. This model is developed to ascertain an optimal ordering strategy for procuring raw materials by using regular multi-external and local backup suppliers to reduce the total cost of the products, and at the same time to reduce the risks arising from this cost reduction within production systems. A comparison between the cost of using the JIT system and using the proposed inventory model shows the superiority of the use of the inventory model.
Abstract: The paper provides the basic overview of simulation optimization. The procedure of its practical using is demonstrated on the real example in simulator Witness. The simulation optimization is presented as a good tool for solving many problems in real praxis especially in production systems. The authors also characterize their own experiences and they mention the strengths and weakness of simulation optimization.