Abstract: In the age of automation and computation aiding manufacturing, it is clear that manufacturing systems have become more complex than ever before. Although technological advances provide the capability to gain more value with fewer resources, sometimes utilisation of the manufacturing capabilities available to organisations is difficult to achieve. Flexible manufacturing systems (FMS) provide a unique capability to manufacturing organisations where there is a need for product range diversification by providing line efficiency through production flexibility. This is very valuable in trend driven production set-ups or niche volume production requirements. Although FMS provides flexible and efficient facilities, its optimal set-up is key in achieving production performance. As many variables are interlinked due to the flexibility provided by the FMS, analytical calculations are not always sufficient to predict the FMS’ performance. Simulation modelling is capable of capturing the complexity and constraints associated with FMS. This paper demonstrates how discrete event simulation (DES) can address complexity in an FMS to optimise the production line performance. A case study of an automotive FMS is presented. The DES model demonstrates different configuration options depending on prioritising objectives: utilisation and throughput. Additionally, this paper provides insight into understanding the impact of system set-up constraints on the FMS performance and demonstrates the exploration into the optimal production set-up.
Abstract: This paper uses a primary data from 670 Chinese
manufacturing firms, together with the newly introduced regressionbased
inequality decomposition method, to study the effect of
openness on wage inequality. We find that openness leads to a
positive industry wage premium, but its contribution to firm-level
wage inequality is relatively small, only 4.69%. The major
contributor to wage inequality is human capital, which could explain
14.3% of wage inequality across sample firms.
Abstract: To improve the manufacturing efficiency of biologics, such as antibody drugs, a quality engineering framework was designed. Within this framework, critical steps and parameters in the manufacturing process were studied. Identification of these critical steps and critical parameters allows a deeper understanding of manufacturing capabilities, and suggests to process development department process control standards based on actual manufacturing capabilities as part of a PDCA (plan-do-check-act) cycle. This cycle can be applied to each manufacturing process so that it can be standardized, reducing the time needed to establish each new process.
Abstract: Recycling, as part of any sustainable environment, is continuously evolving and impacting on new materials in manufacturing. One example of this is the recycled solid waste of Tetra Pak ™ packaging, which is a highly pollutant waste as it is not biodegradable since it is manufactured with different materials. The Tetra Pak ™ container consists of thermally joined layers of paper, aluminum and polyethylene. Once disposed, this packaging is recycled by completely separating the paperboard from the rest of the materials. The aluminum and the polyethylene remain together and are used to create the poly-aluminum, which is widely used to manufacture roof tiles. These recycled tiles have different thermal and acoustic properties compared with traditional manufactured ceramic and cement tiles. In this work, we compare a group of tiles using nondestructive optical testing to measure the superficial micro deformations of the tiles under well controlled experiments. The results of the acoustic and thermal tests show remarkable differences between the recycled tile and the traditional ones. These results help to determine which tile could be better suited to the specific environmental conditions in countries where extreme climates, ranging from tropical, desert-like, to very cold are experienced throughout the year.
Abstract: The present work is devoted to thermographic studies of curved composite panels (unidirectional GFRP) with subsurface defects. Various artificial defects, created by inserting PTFE stripe between individual layers of a laminate during manufacturing stage are studied. The analysis is conducted both with the use finite element method and experiments. To simulate transient heat transfer in 3D model with embedded various defect sizes, the ANSYS package is used. Pulsed Thermography combined with optical excitation source provides good results for flat surfaces. Composite structures are mostly used in complex components, e.g., pipes, corners and stiffeners. Local decrease of mechanical properties in these regions can have significant influence on strength decrease of the entire structure. Application of active procedures of thermography to defect detection and evaluation in this type of elements seems to be more appropriate that other NDT techniques. Nevertheless, there are various uncertainties connected with correct interpretation of acquired data. In this paper, important factors concerning Infrared Thermography measurements of curved surfaces in the form of cylindrical panels are considered. In addition, temperature effects on the surface resulting from complex geometry and embedded and real defect are also presented.
Abstract: Wetting efficiency of microstructures or nanostructures patterned on Si wafers is a real challenge in integrated circuits manufacturing. In fact, bad or non-uniform wetting during wet processes limits chemical reactions and can lead to non-complete etching or cleaning inside the patterns and device defectivity. This issue is more and more important with the transistors size shrinkage and concerns mainly high aspect ratio structures. Deep Trench Isolation (DTI) structures enabling pixels’ isolation in imaging devices are subject to this phenomenon. While low-frequency acoustic reflectometry principle is a well-known method for Non Destructive Test applications, we have recently shown that it is also well suited for nanostructures wetting characterization in a higher frequency range. In this paper, we present a high-frequency acoustic reflectometry characterization of DTI wetting through a confrontation of both experimental and modeling results. The acoustic method proposed is based on the evaluation of the reflection of a longitudinal acoustic wave generated by a 100 µm diameter ZnO piezoelectric transducer sputtered on the silicon wafer backside using MEMS technologies. The transducers have been fabricated to work at 5 GHz corresponding to a wavelength of 1.7 µm in silicon. The DTI studied structures, manufactured on the wafer frontside, are crossing trenches of 200 nm wide and 4 µm deep (aspect ratio of 20) etched into a Si wafer frontside. In that case, the acoustic signal reflection occurs at the bottom and at the top of the DTI enabling its characterization by monitoring the electrical reflection coefficient of the transducer. A Finite Difference Time Domain (FDTD) model has been developed to predict the behavior of the emitted wave. The model shows that the separation of the reflected echoes (top and bottom of the DTI) from different acoustic modes is possible at 5 Ghz. A good correspondence between experimental and theoretical signals is observed. The model enables the identification of the different acoustic modes. The evaluation of DTI wetting is then performed by focusing on the first reflected echo obtained through the reflection at Si bottom interface, where wetting efficiency is crucial. The reflection coefficient is measured with different water / ethanol mixtures (tunable surface tension) deposited on the wafer frontside. Two cases are studied: with and without PFTS hydrophobic treatment. In the untreated surface case, acoustic reflection coefficient values with water show that liquid imbibition is partial. In the treated surface case, the acoustic reflection is total with water (no liquid in DTI). The impalement of the liquid occurs for a specific surface tension but it is still partial for pure ethanol. DTI bottom shape and local pattern collapse of the trenches can explain these incomplete wetting phenomena. This high-frequency acoustic method sensitivity coupled with a FDTD propagative model thus enables the local determination of the wetting state of a liquid on real structures. Partial wetting states for non-hydrophobic surfaces or low surface tension liquids are then detectable with this method.
Abstract: The aim of this study is to present the results of a retrospective survey on the foreign matter found in foods analyzed at the Adolfo Lutz Institute, from July 2001 to July 2015. All the analyses were conducted according to the official methods described on Association of Official Agricultural Chemists (AOAC) for the micro analytical procedures and Food and Drug Administration (FDA) for the macro analytical procedures. The results showed flours, cereals and derivatives such as baking and pasta products were the types of food where foreign matters were found more frequently followed by condiments and teas. Fragments of stored grains insects, its larvae, nets, excrement, dead mites and rodent excrement were the most foreign matter found in food. Besides, foreign matters that can cause a physical risk to the consumer’s health such as metal, stones, glass, wood were found but rarely. Miscellaneous (shell, sand, dirt and seeds) were also reported. There are a lot of extraneous materials that are considered unavoidable since are something inherent to the product itself, such as insect fragments in grains. In contrast, there are avoidable extraneous materials that are less tolerated because it is preventable with the Good Manufacturing Practice. The conclusion of this work is that although most extraneous materials found in food are considered unavoidable it is necessary to keep the Good Manufacturing Practice throughout the food processing as well as maintaining a constant surveillance of the production process in order to avoid accidents that may lead to occurrence of these extraneous materials in food.
Abstract: This paper presents the findings of successful implementation of Business Process Reengineering (BPR) of cement dispatch activities in a cement manufacturing plant located in India. Simulation model was developed for the purpose of identifying and analyzing the areas for improvement. The company was facing a problem of low throughput rate and subsequent forced stoppages of the plant leading to a high production loss of 15000MT per month. It was found from the study that the present systems and procedures related to the in-plant logistics plant required significant changes. The major recommendations included process improvement at the entry gate, reducing the cycle time at the security gate and installation of an additional weigh bridge. This paper demonstrates how BPR can be implemented for improving the in-plant logistics process. Various recommendations helped the plant to increase its throughput by 14%.
Abstract: Processes of production of innovative medical tools have interdisciplinary character. They consist of direct and indirect close cooperation of specialists of different scientific branches. The Knowledge they have seems to be important for undertaken design, construction and manufacturing processes. The Knowledge exchange between participants of these processes is therefore crucial for the final result, which are innovative medical products. The paper draws attention to the necessity of feedback from the end user to the designer / manufacturer of medical tools which will allow for more accurate understanding of user needs. The study describes prerequisites of production processes of innovative medical (surgical) tools including participants and category of knowledge resources occurring in these processes. They are the result of research in selected Polish organizations involved in the production of medical instruments and are the basis for further work on the development of knowledge sharing model in interdisciplinary teams geographically dispersed.
Abstract: The material selection problem is concerned with the
determination of the right material for a certain product to optimize
certain performance indices in that product such as mass, energy
density, and power-to-weight ratio. This paper is concerned about
optimizing the selection of the manufacturing process along with the
material used in the product under performance indices and
availability constraints. In this paper, the material selection problem
is formulated using binary programming and solved by genetic
algorithm. The objective function of the model is to minimize the
total manufacturing cost under performance indices and material and
manufacturing process availability constraints.
Abstract: Centrifugal-casting machine is used in manufacturing
special machine components like multi-layer journal bearing used in
all internal combustion engine, steam, gas turbine and air craft turboengine
where isotropic properties and high precisions are desired.
Moreover, this machine can be used in manufacturing thin wall hightech
machine components like cylinder liners and piston rings of IC
engine and other machine parts like sleeves, and bushes. Heavy-duty
machine component like railway wheel can also be prepared by
centrifugal casting. A lot of technological developments are required
in casting process for production of good casted machine body and
machine parts. Usually defects like blowholes, surface roughness,
chilled surface etc. are found in sand casted machine parts. But these
can be removed by centrifugal casting machine using rotating
metallic die. Moreover, die rotation, its temperature control, and good
pouring practice can contribute to the quality of casting because of
the fact that the soundness of a casting in large part depends upon
how the metal enters into the mold or dies and solidifies. Poor
pouring practice leads to variety of casting defects such as
temperature loss, low quality casting, excessive turbulence, over
pouring etc. Besides these, handling of molten metal is very
unsecured and dangerous for the workers. In order to get rid of all
these problems, the need of an automatic pouring device arises. In
this research work, a robot assisted pouring device and a centrifugal
casting machine are designed, developed constructed and tested
experimentally which are found to work satisfactorily. The robot
assisted pouring device is further modified and developed for using it
in actual metal casting process. Lot of settings and tests are required
to control the system and ultimately it can be used in automation of
centrifugal casting machine to produce high-tech machine parts with
desired precision.
Abstract: A composite material with carbon fiber and polymer
matrix has been used as adherent for manufacturing adhesive joints.
In order to evaluate different fiber orientations on joint performance,
the adherents with the 0°, ±15°, ±30°, ±45° fiber orientations were
used in the single lap joint configuration. The joints with an overlap
length of 25 mm were prepared according to the ASTM 1002
specifications and subjected to tensile loadings. The structural
adhesive used was a two-part epoxy to be cured at 70°C for an hour.
First, mechanical behaviors of the adherents were measured using
three point bending test. In the test, considerations were given to
stress to failure and elastic modulus. The results were compared with
theoretical ones using rule of mixture. Then, the joints were
manufactured in a specially prepared jig, after a proper surface
preparation. Experimental results showed that the fiber orientations
of the adherents affected the joint performance considerably; the
joints with ±45° adherents experienced the worst shear strength, half
of those with 0° adherents, and in general, there was a great
relationship between the fiber orientations and failure mechanisms.
Delamination problems were observed for many joints, which were
thought to be due to peel effects at the ends of the overlap. It was
proved that the surface preparation applied to the adherent surface
was adequate. For further explanation of the results, a numerical
work should be carried out using a possible non-linear analysis.
Abstract: The paper presents an additive manufacturing process for the production of metal and composite parts. It is termed as composite metal foil manufacturing and is a combination of laminated object manufacturing and brazing techniques. The process has been described in detail and is being used to produce dissimilar aluminum to copper foil single lap joints. A three dimensional finite element model has been developed to study the thermo-mechanical characteristics of the dissimilar Al/Cu single lap joint. The effects of thermal stress and strain have been analyzed by carrying out transient thermal analysis on the heated plates used to join the two 0.1mm thin metal foils. Tensile test has been carried out on the foils before joining and after the single Al/Cu lap joints are made, they are subjected to tensile lap-shear test to analyze the effect of heat on the foils. The analyses are designed to assess the mechanical integrity of the foils after the brazing process and understand whether or not the heat treatment has an effect on the fracture modes of the produced specimens.
Abstract: Nanotechnology in pristine sense refers to building of
structures at atomic and molecular scale. Meticulously
nanotechnology encompasses the nanomaterials with at least one
dimension size ranging from 1 to 100 nanometres. Unlike the literal
meaning of its name, nanotechnology is a massive concept beyond
imagination. This paper predominantly deals with relevance of
nanotechnology in automotive industries. New generation of
automotives looks at nanotechnology as an emerging trend of
manufacturing revolution. Intricate shapes can be made out of fairly
inexpensive raw materials instead of conventional fabrication
process. Though the current era have enough technology to face
competition, nanotechnology can give futuristic implications to pick
up the modern pace. Nanotechnology intends to bridge the gap
between automotives with superior technical performance and their
cost fluctuation. Preliminarily, it is an area of great scientific interest
and a major shaper of many new technologies. Nanotechnology can
be an ideal building block for automotive industries, under constant
evolution offering a very wide scope of activity. It possesses huge
potential and is still in the embryonic form of research and
development.
Abstract: Manufacturing process has been considered as one of
the most important activity in business process. It correlates with
productivity and quality of the product so industries could fulfill
customer’s demand. With the increasing demand from customer,
industries must improve their manufacturing ability such as shorten
lead-time and reduce wastes on their process. Lean manufacturing
has been considered as one of the tools to waste elimination in
manufacturing or service industry. Workforce development is one
practice in lean manufacturing that can reduce waste generated from
operator such as waste of unnecessary motion. Anthropometric
approach is proposed to determine the recommended measurement in
operator’s work area. The method will get some dimensions from
Indonesia people that related to piston workstation. The result from
this research can be obtained new design for the work area
considering ergonomic aspect.
Abstract: A myriad of environmental issues face the Nigerian
industrial region, resulting from; oil and gas production, mining,
manufacturing and domestic wastes. Amidst these, much effort has
been directed by stakeholders in the Nigerian oil producing regions,
because of the impacts of the region on the wider Nigerian economy.
Although collaborative environmental management has been noted as
an effective approach in managing environmental issues, little
attention has been given to the roles and practices of stakeholders in
effecting a collaborative environmental management framework for
the Nigerian oil-producing region. This paper produces a framework
to expand and deepen knowledge relating to stakeholders aspects of
collaborative roles in managing environmental issues in the Nigeria
oil-producing region. The knowledge is derived from analysis of
stakeholders’ practices – studied through multiple case studies using
document analysis. Selected documents of key stakeholders –
Nigerian government agencies, multi-national oil companies and host
communities, were analyzed. Open and selective coding was
employed manually during document analysis of data collected from
the offices and websites of the stakeholders. The findings showed
that the stakeholders have a range of roles, practices, interests, drivers
and barriers regarding their collaborative roles in managing
environmental issues. While they have interests for efficient resource
use, compliance to standards, sharing of responsibilities, generating
of new solutions, and shared objectives; there is evidence of major
barriers and these include resource allocation, disjointed policy,
ineffective monitoring, diverse socio- economic interests, lack of
stakeholders’ commitment and limited knowledge sharing. However,
host communities hold deep concerns over the collaborative roles of
stakeholders for economic interests, particularly, where government
agencies and multi-national oil companies are involved. With these
barriers and concerns, a genuine stakeholders’ collaboration is found
to be limited, and as a result, optimal environmental management
practices and policies have not been successfully implemented in the
Nigeria oil-producing region. A framework is produced that describes
practices that characterize collaborative environmental management
might be employed to satisfy the stakeholders’ interests. The
framework recommends critical factors, based on the findings, which
may guide a collaborative environmental management in the oil
producing regions. The recommendations are designed to re-define
the practices of stakeholders in managing environmental issues in the
oil producing regions, not as something wholly new, but as an
approach essential for implementing a sustainable environmental
policy. This research outcome may clarify areas for future research as
well as to contribute to industry guidance in the area of collaborative
environmental management.
Abstract: Customer’ needs, quality, and value creation while
reducing costs through supply chain management provides challenges
and opportunities for companies and researchers. In the light of these
challenges, modern ideas must contribute to counter these challenges
and exploit opportunities. Therefore, this paper discusses the impact
of the quality cost on revenue sharing as a most important incentive
to configure business networks. This paper develops the quality cost approach to align with the
modern era. It develops a model to measure quality costs which
might enable firms to manage revenue sharing in a supply chain. The
developed model includes five categories; besides the well-known
four categories (namely prevention costs, appraisal costs, internal
failure costs, and external failure costs), a new category has been
developed in this research as a new vision of the relationship between
quality costs and innovations in industry. This new category is
Recycle Cost. This paper also examines whether such quality costs in
supply chains influence the revenue sharing between partners. Using the author's quality cost model, the relationship between
quality costs and revenue sharing among partners is examined using a
case study in an Egyptian manufacturing company which is a part of
a supply chain. This paper argues that the revenue-sharing proportion
allocated to supplier increases as the recycle cost of supplier
increases, and the revenue-sharing proportion allocated to
manufacturer increases as the prevention and appraisal costs increase,
as well as the failure costs, the recycle costs of manufacturer, and the
recycle costs of suppliers decrease. However, the results present
surprising findings. The purposes of this study are developing quality cost approach
and understanding the relationships between quality costs and
revenue sharing in supply chains. Therefore, the present study
contributes to theory and practice by explaining how the cost of
recycling can be combined in quality cost model to better
understanding the revenue sharing among partners in supply chains.
Abstract: Lead being a toxic heavy metal that mankind is
exposed to the highest levels of this metal. There are different sources
of environmental pollution with lead as lead alkyl additives in petrol
and manufacturing processes. The contaminated atmosphere in urban
and industrial areas by lead in Egypt may lead to the contamination
of foods beside the other different sources. The present investigation
studied the risk assessment of lead in some Egyptian edible
vegetables and fruits collected from different environments in Greater
Cairo Governorate, i.e. industrial, heavy traffic and rural areas. A
total of 325 leafy and fruity vegetables and fruits samples belonging
to 11, 6 and 4 different species, respectively were randomly collected
from markets of the three main models. Data indicated the variation
of lead levels in different three areas. The highest levels of lead were
detected in the samples collected from industrial and traffic areas.
However, the lowest levels were found in the rural areas. It could be
concluded that determination of lead levels in foods from different
localities and environments at regularly is very important.
Abstract: Coal fly ash, an industrial by product of coal
combustion thermal power plants is considered as a hazardous
material and its improper disposal has become an environmental
issue. On the other hand, manufacturing conventional clay bricks
involves on consumption of large amount of clay and leads
substantial depletion of topsoil. This paper unveils the possibility of
using fly ash as a partial replacement of clay for brick manufacturing
considering the local technology practiced in Bangladesh. The effect
of fly ash with different replacing ratio (0%, 20%, 30%, 40%, and
50% by volume) of clay on properties of bricks was studied. Bricks
were made in the field parallel to ordinary bricks marked with
specific number for different percentage to identify them at time of
testing. No physical distortion is observed in fly ash brick after
burning in the kiln. Results from laboratory test show that
compressive strength of brick is decreased with the increase of fly
ash and maximum compressive strength is found to be 19.6 MPa at
20% of fly ash. In addition, water absorption of fly ash brick is
increased with the increase of fly ash. The abrasion value and
Specific gravity of coarse aggregate prepared from brick with fly ash
also studied and the results of this study suggests that 20% fly ash
can be considered as the optimum fly ash content for producing good
quality bricks utilizing present practiced technology.
Abstract: Over the past few decades, manufacturing has evolved
from a more labor-intensive set of mechanical processes to a
sophisticated set of information based technology processes. With the
existence of various advanced manufacturing technologies (AMTs),
more and more functions or jobs are performed by these machines
instead of human labour. This study was undertaken in order to
research the extent of AMTs adoption in manufacturing companies in
Kenya. In order to investigate a survey was conducted via
questionnaires that were sent to 183 selected AMT manufacturing
companies in Kenya. 92 companies responded positively. All the
surveyed companies were found to have a measure of investment in
at least two of the 14 types of AMTs investigated. In general the
company surveyed showed that the level of AMT adoption in Kenya
is very low with investments levels at a mean of 2.057 and
integration levels at a mean of 1.639 in a scale of 1-5.