Abstract: Environmental impacts of six 3D printers using
various materials were compared to determine if material choice
drove sustainability, or if other factors such as machine type, machine
size, or machine utilization dominate. Cradle-to-grave life-cycle
assessments were performed, comparing a commercial-scale FDM
machine printing in ABS plastic, a desktop FDM machine printing in
ABS, a desktop FDM machine printing in PET and PLA plastics, a
polyjet machine printing in its proprietary polymer, an SLA machine
printing in its polymer, and an inkjet machine hacked to print in salt
and dextrose. All scenarios were scored using ReCiPe Endpoint H
methodology to combine multiple impact categories, comparing
environmental impacts per part made for several scenarios per
machine. Results showed that most printers’ ecological impacts were
dominated by electricity use, not materials, and the changes in
electricity use due to different plastics was not significant compared
to variation from one machine to another. Variation in machine idle
time determined impacts per part most strongly. However, material
impacts were quite important for the inkjet printer hacked to print in
salt: In its optimal scenario, it had up to 1/38th the impacts coreper
part as the worst-performing machine in the same scenario. If salt
parts were infused with epoxy to make them more physically robust,
then much of this advantage disappeared, and material impacts
actually dominated or equaled electricity use. Future studies should
also measure DMLS and SLS processes / materials.
Abstract: Due to water shortage, application of saline water for
irrigation is an urgent in agriculture. In this study the effect of
calcium and potassium application as additive in saline root media for
reduce salinity adverse effects was investigated on tomato growth in
a hydroponic system with unequal distribution of salts in the root
media, which was divided in to two equal parts containing full
Johnson nutrient solution and 40 mMNaCl solution, alone or in
combination with KCl (6 mM), CaCl2 (4 mM), K+Ca (3+2 mM) or
half-strength Johnson nutrient solution. The root splits were
exchanged every 7 days. Results showed that addition of calcium,
calcium-potassium and nutrition elements equivalent to half the
concentration of Johnson formula to the saline-half of culture media
minimized the reduction in plant growth caused by NaCl, although
addition of potassium to culture media wasn’t effective. The greatest
concentration of sodium was observed at the shoot of treatments
which had smallest growth. According to the results of this study, in
case of dynamic and non-uniform distribution of salts in the root
media, by addition of additive to the saline solution, it would be
possible to use of saline water with no significant growth reduction.
Abstract: The IEEE 802.22 working group aims to drive the
Digital Video Broadcasting-Terrestrial (DVB-T) bands for data
communication to the rural area without interfering the TV broadcast.
In this paper, we arrive at a closed-form expression for average
detection probability of Fusion center (FC) with multiple antenna
over the κ − μ fading channel model. We consider a centralized
cooperative multiple antenna network for reporting. The DVB-T
samples forwarded by the secondary user (SU) were combined using
Maximum ratio combiner at FC, an energy detection is performed
to make the decision. The fading effects of the channel degrades
the detection probability of the FC, a generalized independent and
identically distributed (IID) κ − μ and an additive white Gaussian
noise (AWGN) channel is considered for reporting and sensing
respectively. The proposed system performance is verified through
simulation results.
Abstract: In this paper, the dynamic characteristics of a threelobe
journal bearing lubricated with micropolar fluids are determined
by the linear stability theory. Lubricating oil containing additives and
contaminants is modelled as micropolar fluid. The modified
Reynolds equation is obtained using the micropolar lubrication theory
.The finite difference technique has been used to determine the
solution of the modified Reynolds equation. The dynamic
characteristics in terms of stiffness, damping coefficients, the critical
mass and whirl ratio are determined for various values of size of
material characteristic length and the coupling number. The
computed results show that the three-lobe bearing lubricated with
micropolar fluid exhibits better stability compared with that
lubricated with Newtonian fluid. According to the results obtained,
the effect of the parameter micropolar fluid is remarkable on the
dynamic characteristics and stability of the three-lobe bearing.
Abstract: Regardless of the manufacturing process used,
subtractive or additive, material, purpose and application, produced
components are conventionally solid mass with more or less complex
shape depending on the production technology selected. Aspects
such as reducing the weight of components, associated with the low
volume of material required and the almost non-existent material
waste, speed and flexibility of production and, primarily, a high
mechanical strength combined with high structural performance, are
competitive advantages in any industrial sector, from automotive,
molds, aviation, aerospace, construction, pharmaceuticals, medicine
and more recently in human tissue engineering. Such features,
properties and functionalities are attained in metal components
produced using the additive technique of Rapid Prototyping from
metal powders commonly known as Selective Laser Melting (SLM),
with optimized internal topologies and varying densities. In order to
produce components with high strength and high structural and
functional performance, regardless of the type of application, three
different internal topologies were developed and analyzed using
numerical computational tools. The developed topologies were
numerically submitted to mechanical compression and four point
bending testing. Finite Element Analysis results demonstrate how
different internal topologies can contribute to improve mechanical
properties, even with a high degree of porosity relatively to fully
dense components. Results are very promising not only from the
point of view of mechanical resistance, but especially through the
achievement of considerable variation in density without loss of
structural and functional high performance.
Abstract: Vacuum Insulation Panel (VIP) can achieve very low
thermal conductivity by evacuating its inner space. Heat transfer in the
core materials of highly-evacuated VIP occurs by conduction through
the solid structure and radiation through the pore. The effect of various
scattering modes in combined conduction-radiation in VIP is
investigated through numerical analysis. The discrete ordinates
interpolation method (DOIM) incorporated with the commercial code
FLUENT® is employed. It is found that backward scattering is more
effective in reducing the total heat transfer while isotropic scattering is
almost identical with pure absorbing/emitting case of the same optical
thickness. For a purely scattering medium, the results agrees well with
additive solution with diffusion approximation, while a modified term
is added in the effect of optical thickness to backward scattering is
employed. For other scattering phase functions, it is also confirmed
that backwardly scattering phase function gives a lower effective
thermal conductivity. Thus the materials with backward scattering
properties, with radiation shields are desirable to lower the thermal
conductivity of VIPs.
Abstract: The objective of this study was to determine effect of
dietary essential oil (EO) compounds, which contained
cinnamaldehyde, eugenol, peppermint, coriander, cumin, lemongrass,
and an organic carrier on feed intake, milk composition, and rumen
fermentation of dairy cows during heat exposure. Thirty-two Holstein
cows (days in milk= 60 ± 5) were assigned to one of two treatment
groups: a Control and EO fed. The experiment lasted 28 days. Dry
matter intake (DMI) was measured daily while and milk production
was measured weekly. Our result showed that DMI and milk yield
was decreased (P < 0.01) in control cows relative to EO cows.
Furthermore, supplementation with EO was associated with a
decrease in the molar proportion of propionate (P < 0.05) and
increase (P < 0.05) in acetate to propionate ratio. In conclusion, EO
supplementations in diets can be useful nutritional modification to
alleviate for the decrease DMI and milk production during heat
exposure in lactating dairy cows.
Abstract: Asphaltic concrete for pavement construction in India
are produced by using crushed stone, gravels etc. as aggregate. In
north-Eastern region of India, there is a scarcity of stone aggregate.
Therefore the road engineers are always in search of an optional
material as aggregate which can replace the regularly used material.
The purpose of this work was to evaluate the utilization of
substandard or marginal aggregates in flexible pavement
construction. The investigation was undertaken to evaluate the effects
of using lower quality aggregates such as over burnt brick aggregate
on the preparation of asphalt concrete for flexible pavements. The
scope of this work included a review of available literature and
existing data, a laboratory evaluation organized to determine the
effects of marginal aggregates and potential techniques to upgrade
these substandard materials, and a laboratory evaluation of these
upgraded marginal aggregate asphalt mixtures. Over burnt brick
aggregates are water susceptible and can leads to moisture damage.
Moisture damage is the progressive loss of functionality of the
material owing to loss of the adhesion bond between the asphalt
binder and the aggregate surface. Hence zycosoil as an anti striping
additive were evaluated in this study. This study summarizes the
results of the laboratory evaluation carried out to investigate the
properties of asphalt concrete prepared with zycosoil modified over
burnt brick aggregate. Marshall specimen were prepared with stone
aggregate, zycosoil modified stone aggregate, over burnt brick
aggregate and zycosoil modified over burnt brick aggregate. Results
show that addition of zycosoil with stone aggregate increased
stability by 6% and addition of zycosoil with over burnt brick
aggregate increased stability by 30%.
Abstract: In the present work, the effects of additives, including
contents of the added antioxidants and type of the selected metallic
stearates (either calcium stearate (CaSt) or zinc stearate (ZnSt)), on
the thermal stabilities of carbon black (CB)/high density polyethylene
(HDPE) compounds were studied. The results showed that the AO
contents played a key role in the thermal stabilities of the CB/HDPE
compounds — the higher the AO content, the higher the thermal
stabilities. Although the CaSt-containing compounds were slightly
superior to those with ZnSt in terms of the thermal stabilities, the
remaining solid residue of CaSt after heated to the temperature of 600
°C (mainly calcium carbonate (CaCO3) as characterized by the X-ray
diffraction (XRD) technique) seemed to catalyze the decomposition
of CB in the HDPE-based compounds. Hence, the quantification of
CB in the CaSt-containing compounds with a muffle furnace gave an
inaccurate CB content — much lower than actual value. However,
this phenomenon was negligible in the ZnSt-containing system.
Abstract: This paper focuses on the presentation of results
which were obtained as a part of the project FR-TI 3/742: “System of
Lightweight Materials for Finishing of Buildings with Waste Raw
Materials”. Attention was paid to the light weighting of polymermodified
mortars applicable as adhesives, screeds and repair mortars.
In terms of repair mortars, they were ones intended for the sanitation
of aerated concrete.
Abstract: Load carrying capacity of an oil lubricated two-axial
groove journal bearing is simulated by taking into account the
viscosity variations in lubricant due to the addition of TiO2
nanoparticles as lubricant additive. Shear viscosities of TiO2
nanoparticle dispersions in oil are measured for various nanoparticle
additive concentrations. The viscosity model derived from the
experimental viscosities is employed in a modified Reynolds
equation to obtain the pressure profiles and load carrying capacity of
two-axial groove journal bearing. Results reveal an increase in load
carrying capacity of bearings operating on nanoparticle dispersions as
compared to plain oil.
Abstract: A simple, accurate and precise direct spectrophotometric method has been developed for the determination of cefixime in tablets and capsules. The method is based on the reaction of cefixime with a mixture of potassium iodide and potassium iodate to form yellow coloured product in ethanol-distilled water medium at room temperature which absorbed maximally at 352 nm. The factors affecting the reaction product were carefully studied and optimized. The validation parameters based on International Conference on Harmonisation (ICH, USA) guidelines were followed. The effect of common excipients used as additives has been tested and the tolerance limit was calculated for the determination of cefixime. Beer’s law is obeyed in the concentration range of 4 – 24 ug mL-1 with apparent molar absorptivity of 1.52 × 104 L mol-1cm-1 and Sandell’s sensitivity of 0.033 ug/cm2/ 0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.32 and 1.06 ug mL-1, respectively. The proposed method has been successfully applied for the determination of cefixime in pharmaceutical formulations. The results obtained by the proposed method were statistically compared with the reference method using t- and F- values and found no significant difference between the two methods. The proposed method can be used as an alternate method for routine quality control analysis of cefixime in pharmaceutical formulations.
Abstract: Boron-gypsum is a waste which occurs in the boric
acid production process. In this study, the boron content of this waste
is evaluated for the use in synthesis of magnesium borates and such
evaluation of this kind of waste is useful more than storage or
disposal. Magnesium borates, which are a sub-class of boron
minerals, are useful additive materials for the industries due to their
remarkable thermal and mechanical properties. Magnesium borates
were obtained hydrothermally at different temperatures. Novelty of
this study is the search of the solution density effects to magnesium
borate synthesis process for the increasing the possibility of borongypsum
usage as a raw material. After the synthesis process, products
are subjected to XRD and FT-IR to identify and characterize their
crystal structure, respectively.
Abstract: This paper is concerned with the stability problem
with two additive time-varying delay components. By choosing one
augmented Lyapunov-Krasovskii functional, using some new zero
equalities, and combining linear matrix inequalities (LMI)
techniques, two new sufficient criteria ensuring the global stability
asymptotic stability of DNNs is obtained. These stability criteria are
present in terms of linear matrix inequalities and can be easily
checked. Finally, some examples are showed to demonstrate the
effectiveness and less conservatism of the proposed method.
Abstract: Lead (Pb) poisoning is one of the most common and
preventable environmental health problems. There are different
sources of environmental pollution with lead as lead alkyl additives
in petrol and manufacturing processes. Pb in the atmosphere can be
deposited in urban soils, and may then be re-suspended to re-enter the
atmosphere. This could increase human exposure to Pb and cause
long-term health effects. Thus, monitoring Pb pollution is considered
one of the major tasks in controlling pollution. Scalp hair can be
utilized for the determination of lead (Pb) concentration. It provides a
lasting record of metal intakes of weeks or even months, and for most
metals, their accumulation in hair reflects their accumulation in the
whole body. This work was conducted to investigate the
concentration of lead in male scalp hair of Cairo (residential-traffic
and residential-industrial) and rural residents after twenty years of
phasing out of leaded gasoline. Results indicated that the mean
concentration of lead in hair of residential-traffic (9.7552 μg/g ±0.71)
and residential-industrial (12.3288 μg/g ±1.13) was significantly
higher than that in rural residents (4.7327 μg/g ±0.67). The mean
concentration of lead in hair of resident’s industrial areas was the
highest among Cairo residents and not the traffic areas as it was
before phasing out of leaded gasoline. Twenty years of phasing out of
leaded gasoline in Cairo has greatly improved the lead pollution
among residents of traffic areas, but industrial areas residents were
still suffering from lead pollution, which needs more efforts to
control the sources of lead pollution.
Abstract: The Analytic Hierarchy Process is frequently used
approach for solving decision making problems. There exists wide
range of software programs utilizing that approach. Their main
disadvantage is that they are relatively expensive and missing
intermediate calculations. This work introduces a Microsoft Excel
add-in called DAME – Decision Analysis Module for Excel.
Comparing to other computer programs DAME is free, can work
with scenarios or multiple decision makers and displays intermediate
calculations. Users can structure their decision models into three
levels – scenarios/users, criteria and variants. Items on all levels can
be evaluated either by weights or pair-wise comparisons. There are
provided three different methods for the evaluation of the weights of
criteria, the variants as well as the scenarios – Saaty’s Method,
Geometric Mean Method and Fuller’s Triangle Method.
Multiplicative and additive syntheses are supported. The proposed
software package is demonstrated on couple of illustrating examples
of real life decision problems.
Abstract: Soy protein is a common ingredient added to processed meats to enhance its functional characteristics. In our study, soybean products (fermented soy Natto and protein hydrolysate) containing hydrolyzed peptides and amino acids, with or without ascorbic acid were added to burger in order to improve its quality characteristics. Results showed that soy additives significantly increased moisture and protein content and reduced (P < 0.05) fat values. Ash content did not affect with Natto additive. Color tools, lightness and yellowness were higher (P
Abstract: This research studies the electroplating of zinc coating
in the zinc chloride bath mixed with supercritical CO2. The sodium
fluoride (NaF) was used as the bath additive to change the structure
and property of the coating, and therefore the roughness and corrosion
resistance of the zinc coating was investigated. The surface
characterization was performed using optical microscope (OM), X-ray
diffractometer (XRD), and α-step profilometer. Moreover, the
potentiodynamic polarization measurement in 3% NaCl solution was
employed in the corrosion resistance evaluation. Because of the
emulsification of the electrolyte mixed in Sc-CO2, the electroplated
zinc produced the coating with smoother surface, smaller grain, better
throwing power and higher corrosion resistance. The main role played
by the NaF was to reduce the coating’s roughness and grain size. In
other words, the CO2 mixed with the electrolyte under the supercritical
condition performed the similar function as brighter and leveler in zinc
electroplating to enhance the throwing power and corrosion resistance
of the coating.
Abstract: Zinc borate is an important boron compound that can be used as multi-functional flame retardant additive due to its high dehydration temperature property. In this study, theraw materials of ZnSO4.7H2O, NaOH and H3BO3werecharacterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) and used in the synthesis of zinc borates.The synthesis parameters were set to 100°C reaction temperature and 120 minutes of reaction time, with different molar ratio of starting materials (ZnSO4.7H2O:NaOH:H3BO3). After the zinc borate synthesis, the identifications of the products were conducted by XRD and FT-IR. As a result,Zinc Oxide Borate Hydrate [Zn3B6O12.3.5H2O], were synthesized at the molar ratios of 1:1:3, 1:1:4, 1:2:5 and 1:2:6. Among these ratios 1:2:6 had the best results.
Abstract: Soybean Natto powder was added to the burger in order to enhance the oxidative stability as well as decreases the microbial spoilage. The soybean bioactives compound (soybean Natto) as antioxidant and antimicrobial were added at level of 1, 2 and 3%. Chemical analysis and physical properties were affected by soybean Natto addition. All the tested soybean Natto additives showed strong antioxidant properties. The microbiological indicators were significantly (P < 0.05) affected by the addition of the soybean Natto. Decreasing trends of different extent were also observed in samples of the treatments for total viable counts, Coliform, Staphylococcus aureus, yeast and molds. Storage period was significantly (P < 0.05) affected on microbial counts in all samples Staphylococcus aureus were the most sensitive microbe followed by Coliform group of the sample containing soybean Natto. Sensory attributes were also performed, added soybean Natto exhibits beany flavor which was clear about samples of 3% soybean Natto.