Abstract: The transesterification of dimethyl malonate (DMM)
with phenol has been studied in vapour phase over cordierite
honeycomb coated with solid acid catalysts such as ZrO2,
Mo(VI)/ZrO2 and SO42-/ZrO2. The catalytic materials were prepared
honeycomb coated, powder forms, and characterized for their total
surface acidity by NH3-TPD and crystalinity by powder XRD
methods. Phenyl methyl malonate (PMM) and diphenyl malonate
(DPM) were obtained as the reaction products. A good conversion of
DMM (up to 82%) of MPM with 95% selectivity was observed when
the reactions were carried out at a catalyst bed temperature of 200 °C
and flow-rate of 10 mL/h in presence of Mo(VI)/ZrO2 as catalyst.
However, over SO4^2-/ZrO2 catalyst, the yield of DPM was found to be
higher. The results have been interpreted based on the variation of
acidic properties and powder XRD phases of zirconia on
incorporation of Mo(VI) or SO42– ions. Transesterification reactions
were also carried out over powder forms of the catalytic materials
and the yield of the desired phenyl ester products were compared
with that of the HC coated catalytic materials. The solid acids were
found to be reusable when used for at least 5 reaction cycles.
Abstract: Considering the challenges of short product life cycles
and growing variant diversity, cost minimization and manufacturing
flexibility increasingly gain importance to maintain a competitive
edge in today’s global and dynamic markets. In this context, an
aerodynamic part feeding system for high-speed industrial assembly
applications has been developed at the Institute of Production
Systems and Logistics (IFA), Leibniz Universitaet Hannover. The
aerodynamic part feeding system outperforms conventional systems
with respect to its process safety, reliability, and operating speed. In
this paper, a multi-objective optimisation of the aerodynamic feeding
system regarding the orientation rate, the feeding velocity, and the
required nozzle pressure is presented.
Abstract: Production fluids are transported from the platform to
tankers or process facilities through transfer pipelines. Water being
one of the heavier phases tends to settle at the bottom of pipelines
especially at low flow velocities and this has adverse consequences
for pipeline integrity. On restart after a shutdown, this could result in
corrosion and issues for process equipment, thus the need to have the
heavier liquid dispersed into the flowing lighter fluid. This study
looked at the flow regime of low water cut and low flow velocity oil
and water flow using conductive film thickness probes in a large
diameter 4-inch pipe to obtain oil and water interface height and the
interface structural velocity. A wide range of 0.1–1.0 m/s oil and
water mixture velocities was investigated for 0.5–5% water cut. Two
fluid model predictions were used to compare with the experimental
results.
Abstract: This research aimed to investigate the relationship
between attitude towards marketing mix, brand image and consumer
behavior of the passengers of low-cost airlines service. This study
employed by quantitative research and the questionnaire was used to
collect the data from 400 sampled of the passengers who have ever
used the low-cost airline services based in Bangkok, Thailand. The
descriptive statistics and Pearson’s correlation analysis were used to
analyze data. The research results revealed that the attitude of the marketing mix
of the low-cost airline services including product, price, place,
promotion and process had related to the consumer behavior on the
aspects of duration of service and frequency of service. While, the
brand image of the low cost airline including the characteristics of
organization, service quality and company identity had related to the
consumer behavior on duration of service, frequency of service and
cost of service at the significant statistically acceptable levels.
Abstract: The aim of this study is to evaluate the effect of
supplementing broiler starter diet with different levels of an essential
oil blend (EOB) containing capsaicin, carvacrol and cinnamaldehyde
on the performance of broilers. A total of 300 day-old straight-run
Cobb broiler chicks were randomly assigned to three treatments after
7-day group brooding following a completely randomized design
(CRD). Birds assigned in treatment 1 were given starter basal diet
while those in treatments 2 and 3 were given starter basal diet with
400 mg/kg antibiotic growth promoter (AGP) and 150 mg/kg EOB,
respectively, until the 28th day. Basal finisher feed were given for all
the treatments until harvest. Following 37 d feeding, body weight
gain, feed consumption, feed efficiency, dressing percentage,
livability and jejunal villi height were determined. Results showed no
significant differences (P>0.05) in growth performance. However,
villi height and crypt depth was significantly lower for birds fed
EOB.
Abstract: The photovoltaic and the semiconductor industries are
in growth and it is necessary to supply a large amount of silicon to
maintain this growth. Since silicon is still the best material for the
manufacturing of solar cells and semiconductor components so the
pure silicon like solar grade and semiconductor grade materials are
demanded. There are two main routes for silicon production:
metallurgical and chemical. In this article, we reviewed the
electrotecnological installations and systems for semiconductor
manufacturing. The main task is to design the installation which can
produce SOG Silicon from river sand by one work unit.
Abstract: In Algeria, the conditioning units of dates, generate
significant quantities of waste arising from sorting deviations. This
biomass, until then considered as a waste with high impact on the
environment can be transformed into high value added product. It is
possible to develop common dates of low commercial value, and put
on the local and international market a new generation of products
with high added values such as bio ethanol. Besides its use in
chemical synthesis, bio ethanol can be blended with gasoline to
produce a clean fuel while improving the octane.
Abstract: This study investigates the influence of low
temperature thermo-chemical pretreatment of organic food waste on
performance of COD solubilisation. Both temperature and alkaline
agent were reported to have effect on solubilizing any possible
biomass including organic food waste. The three independent
variables considered in this pretreatment were temperature (50-90oC),
pretreatment time (30-120 minutes) and alkaline concentration,
sodium hydroxide, NaOH (0.7-15 g/L). The maximal condition
obtained were 90oC, 15 g/L NaOH for 2 hours. Solubilisation has
potential in enhancing methane production by providing high amount
of soluble components at early stage during anaerobic digestion.
Abstract: A theoretical study of a humidification
dehumidification solar desalination unit has been carried out to
increase understanding the effect of weather conditions on the unit
productivity. A humidification-dehumidification (HD) solar
desalination unit has been designed to provide fresh water for
population in remote arid areas. It consists of solar water collector
and air collector; to provide the hot water and air to the desalination
chamber. The desalination chamber is divided into humidification
and dehumidification towers. The circulation of air between the two
towers is maintained by the forced convection. A mathematical
model has been formulated, in which the thermodynamic relations
were used to study the flow, heat and mass transfer inside the
humidifier and dehumidifier. The present technique is performed in
order to increase the unit performance. Heat and mass balance has
been done and a set of governing equations has been solved using the
finite difference technique. The unit productivity has been calculated
along the working day during the summer and winter sessions and
has compared with the available experimental results. The average
accumulative productivity of the system in winter has been ranged
between 2.5 to 4 (kg/m2)/day, while the average summer productivity
has been found between 8 to 12 (kg/m2)/day.
Abstract: Within this paper, latest results on processing of energetic nanomaterials by means of the Spray Flash Evaporation technique are presented. This technology constitutes a highly effective and continuous way to prepare fascinating materials on the nano- and micro-scale. Within the process, a solution is set under high pressure and sprayed into an evacuated atomization chamber. Subsequent ultrafast evaporation of the solvent leads to an aerosol stream, which is separated by cyclones or filters. No drying gas is required, so the present technique should not be confused with spray dying. Resulting nanothermites, insensitive explosives or propellants and compositions are foreseen to replace toxic (according to REACH) and very sensitive matter in military and civil applications. Diverse examples are given in detail: nano-RDX (n-Cyclotrimethylentrinitramin) and nano-aluminum based systems, mixtures (n-RDX/n-TNT - trinitrotoluene) or even cocrystalline matter like n-CL-20/HMX (Hexanitrohexaazaisowurtzitane/ Cyclotetra-methylentetranitramin). These nanomaterials show reduced sensitivity by trend without losing effectiveness and performance. An analytical study for material characterization was performed by using Atomic Force Microscopy, X-Ray Diffraction, and combined techniques as well as spectroscopic methods. As a matter of course, sensitivity tests regarding electrostatic discharge, impact, and friction are provided.
Abstract: The agenda of showing the scheduled time for
performing certain tasks is known as timetabling. It is widely used in
many departments such as transportation, education, and production.
Some difficulties arise to ensure all tasks happen in the time and
place allocated. Therefore, many researchers invented various
programming models to solve the scheduling problems from several
fields. However, the studies in developing the general integer
programming model for many timetabling problems are still
questionable. Meanwhile, this thesis describes about creating a
general model which solves different types of timetabling problems
by considering the basic constraints. Initially, the common basic
constraints from five different fields are selected and analyzed. A
general basic integer programming model was created and then
verified by using the medium set of data obtained randomly which is
much similar to realistic data. The mathematical software, AIMMS
with CPLEX as a solver has been used to solve the model. The model
obtained is significant in solving many timetabling problems easily
since it is modifiable to all types of scheduling problems which have
same basic constraints.
Abstract: Anaerobic digestion is a well-known technique for
sustainable energy recovery from sewage sludge. However, sewage
sludge digestion is restricted due to certain factors. Pre-treatment
methods have been established in various publications as a promising
technique to improve the digestibility of the sewage sludge and to
enhance the biogas generated which can be used for energy recovery.
In this study, continuous flow microwave (MW) pre-treatment with
different intensities were compared by using 5 L semi-continuous
digesters at a hydraulic retention time of 27 days. We focused on the
effects of MW at different intensities on the sludge solubilization,
sludge digestibility, and biogas production of the untreated and MW
pre-treated sludge. The MW pre-treatment demonstrated an increase
in the ratio of soluble chemical oxygen demand to total chemical
oxygen demand (sCOD/tCOD) and volatile fatty acid (VFA)
concentration. Besides that, the total volatile solid (TVS) removal
efficiency and tCOD removal efficiency also increased during the
digestion of the MW pre-treated sewage sludge compared to the
untreated sewage sludge. Furthermore, the biogas yield also
subsequently increases due to the pre-treatment effect. A higher MW
power level and irradiation time generally enhanced the biogas
generation which has potential for sustainable energy recovery from
sewage treatment plant. However, the net energy balance tabulation
shows that the MW pre-treatment leads to negative net energy production.
Abstract: Within Rapid Prototyping technologies are used many
types of materials. Many of them are recyclable but there are still as
plastic like, so practically they do not degrade in the landfill.
Polylactic acid (PLA) is one of the special plastic materials, which
are biodegradable and available for 3D printing within Fused
Deposition Modeling (FDM) technology. The question is, if the
mechanical properties of produced models are comparable to similar
technical plastic materials which are usual for prototype production.
Presented paper shows the experiments results for tensile strength
measurements for specimens prepared with different 3D printer
settings and model orientation. Paper contains also the comparison of
tensile strength values with values measured on specimens produced
by conventional technologies as injection moulding.
Abstract: Broiler slaughter waste has become a major source of
pollution throughout the world. Utilization of broiler slaughter waste
by dry rendering process produced Rendered Chicken Oil (RCO), a
cheap raw material for biodiesel production and Carcass Meal a feed
ingredient for pets and fishes. Conversion of RCO into biodiesel may
open new vistas for generating wealth from waste besides controlling
the major havoc of environmental pollution. A two-step process to
convert RCO to good quality Biodiesel was invented. Acid catalysed
esterification of FFA followed by base catalysed transesterification of
triglycerides was carried out after meticulously standardizing the
methanol molar ratio, catalyst concentration, reaction temperature,
and reaction time to obtain the maximum biodiesel yield of 97.62%
and lowest glycerol yield of 6.96%. RCO biodiesel blend was tested
in a CRDI diesel engine. The results revealed that the blending of
commercial diesel with 20% RCO biodiesel (B20) lead to less engine
wear, a quieter engine and better fuel economy. The better lubricating
qualities of RCO B20 prevented over heating of engine, which
prolongs the engine life. RCO B20 can reduce the import of crude oil
and substantially reduce the engine emissions as proved by
significantly lower smoke levels, thus mitigating climatic changes.
Abstract: The purpose of this research is to investigate the
marketing mix that is perceived to be important for the small sized
hotels in Pattaya. This research provides insights through a review of
the marketing activities performed by the small sized hotels. Nine
owners & marketing manager of small sized hotels and resorts, all
local Chonburi people, were selected for an in-depth interview. The
research suggests that seven marketing mixes (e.g. Product, Price,
Place, Promotion, People, Physical Evidence and Process) were
commonly used by these hotels, however, three types – People, Price
and Physical Evidence were considered most important by the
owners.
Abstract: This paper is concerned with the ways in which
Assisted Reproductive Technologies (ARTs) affect women’s lives
and perceptions regarding their infertility, contraception and
reproductive health. The paper is based on a qualitative feminist
survey study to explore and analyze issues arising from the use of
ARTs by women in New Delhi, the capital of India. A rapid growth in
the number of fertility clinics has been noticed recently. A critical
analysis of interviews revealed that these technologies are used and
developed for making profits at the cost of women’s lives. In this
way, these technologies are influencing and changing the traditional
patterns of motherhood requiring a rethinking about new ways of
reproduction introduced through the use of ARTs.
Abstract: The plastic industry plays very important role in the
economy of any country. It is generally among the leading share of
the economy of the country. Since metals and their alloys are very
rarely available on the earth. Therefore, to produce plastic products
and components, which finds application in many industrial as well
as household consumer products is beneficial. Since 50% plastic
products are manufactured by injection moulding process. For
production of better quality product, we have to control quality
characteristics and performance of the product. The process
parameters plays a significant role in production of plastic, hence the
control of process parameter is essential. In this paper the effect of
the parameters selection on injection moulding process has been
described. It is to define suitable parameters in producing plastic
product. Selecting the process parameter by trial and error is neither
desirable nor acceptable, as it is often tends to increase the cost and
time. Hence, optimization of processing parameter of injection
moulding process is essential. The experiments were designed with
Taguchi’s orthogonal array to achieve the result with least number of
experiments. Plastic material polypropylene is studied. Tensile
strength test of material is done on universal testing machine, which
is produced by injection moulding machine. By using Taguchi
technique with the help of MiniTab-14 software the best value of
injection pressure, melt temperature, packing pressure and packing
time is obtained. We found that process parameter packing pressure
contribute more in production of good tensile plastic product.
Abstract: The increase of technogenic and natural accidents,
accompanied by air pollution, for example, by combustion products,
leads to the necessity of respiratory protection. This work is devoted to the development of a calorimetric method
and a device which allows investigating quickly the kinetics of
carbon dioxide sorption by chemisorbents on the base of potassium
superoxide in order to assess the protective properties of respiratory
protective closed circuit apparatus. The features of the traditional approach for determining the
sorption properties in a thin layer of chemisorbent are described, as
well as methods and devices, which can be used for the sorption
kinetics study. The authors developed an approach (as opposed to the traditional
approach) based on the power measurement of internal heat sources
in the chemisorbent layer. The emergence of the heat sources is a
result of exothermic reaction of carbon dioxide sorption. This
approach eliminates the necessity of chemical analysis of samples
and can significantly reduce the time and material expenses during
chemisorbents testing. Error of determining the volume fraction of adsorbed carbon
dioxide by the developed method does not exceed 12%. Taking into
account the efficiency of the method, we consider that it is a good
alternative to traditional methods of chemical analysis under the
assessment of the protection sorbents quality.
Abstract: A method of effective planning and control of
industrial facility energy consumption is offered. The method allows
optimally arranging the management and full control of complex
production facilities in accordance with the criteria of minimal
technical and economic losses at the forecasting control. The method
is based on the optimal construction of the power efficiency
characteristics with the prescribed accuracy. The problem of optimal
designing of the forecasting model is solved on the basis of three
criteria: maximizing the weighted sum of the points of forecasting
with the prescribed accuracy; the solving of the problem by the
standard principles at the incomplete statistic data on the basis of
minimization of the regularized function; minimizing the technical
and economic losses due to the forecasting errors.
Abstract: Local steel slag is produced as a by-product during the
oxidation of steel pellets in an electric arc furnace. Using local steel
slag waste as a hundred substitutes of crashed stone in construction
materials would resolve the environmental problems caused by the
large-scale depletion of the natural sources of crashed stone. This
paper reports the experimental study to investigate the influence of a
hundred replacement of crashed stone as a coarse aggregate with
local steel slag, on the fresh and hardened geopolymer concrete
properties. The investigation includes traditional testing of hardening
concrete, for selected mixes of cement and geopolymer concrete. It
was found that local steel slag as a coarse aggregate enhanced the
slump test of the fresh state of cement and geopolymer concretes.
Nevertheless, the unit weight of concretes was affected. Meanwhile,
the good performance was observed when fly ash used as geopolymer
concrete based.