Abstract: This paper aims to study decomposition behavior in
pyrolytic environment of four lignocellulosic biomass (oil palm shell,
oil palm frond, rice husk and paddy straw), and two commercial
components of biomass (pure cellulose and lignin), performed in a
thermogravimetry analyzer (TGA). The unit which consists of a
microbalance and a furnace flowed with 100 cc (STP) min-1 Nitrogen,
N2 as inert. Heating rate was set at 20⁰C min-1 and temperature
started from 50 to 900⁰C. Hydrogen gas production during the
pyrolysis was observed using Agilent Gas Chromatography Analyzer
7890A. Oil palm shell, oil palm frond, paddy straw and rice husk
were found to be reactive enough in a pyrolytic environment of up to
900°C since pyrolysis of these biomass starts at temperature as low as
200°C and maximum value of weight loss is achieved at about
500°C. Since there was not much different in the cellulose,
hemicelluloses and lignin fractions between oil palm shell, oil palm
frond, paddy straw and rice husk, the T-50 and R-50 values obtained
are almost similar. H2 productions started rapidly at this temperature
as well due to the decompositions of biomass inside the TGA.
Biomass with more lignin content such as oil palm shell was found to
have longer duration of H2 production compared to materials of high
cellulose and hemicelluloses contents.
Abstract: This paper deals with the evaluation of flow properties
of polymeric matrix with natural animal fillers. Technical university
of Liberec cooperates on the long-term development of “green
materials“ that should replace conventionally used materials
(especially in automotive industry). Natural fibres (of animal and
plant origin) from all over the world are collected and adapted
(drying, cutting etc.) for extrusion processing. Inside the extruder
these natural additives are blended with polymeric (synthetic and
biodegradable - PLA) matrix and created compound is subsequently
cut for pellets in the wet way. These green materials with unique
recipes are then studied and their mechanical, physical and
processing properties are determined. The main goal of this research
is to develop new ecological materials very similar to unfilled
polymers. In this article the rheological behaviour of chosen natural
animal fibres is introduced considering their shape and surface that
were observed with use of SEM microscopy.
Abstract: The study of piezoelectric material in the past was in
T-Domain form; however, no one has studied piezoelectric material in the S-Domain form. This paper will present the piezoelectric material in the transfer function or S-Domain model. S-Domain is a
well known mathematical model, used for analyzing the stability of the material and determining the stability limits. By using S-Domain
in testing stability of piezoelectric material, it will provide a new tool for the scientific world to study this material in various forms.
Abstract: This paper deals with the problem of thermal and
mechanical shocks, which rising during operation, mostly at
interrupted cut. Here will be solved their impact on the cutting edge
tool life, the impact of coating technology on resistance to shocks
and experimental determination of tool life in heating flame.
Resistance of removable cutting edges against thermal and
mechanical shock is an important indicator of quality as well as its
abrasion resistance. Breach of the edge or its crumble may occur due
to cyclic loading. We can observe it not only during the interrupted
cutting (milling, turning areas abandoned hole or slot), but also in
continuous cutting. This is due to the volatility of cutting force on
cutting. Frequency of the volatility in this case depends on the type
of rising chips (chip size element). For difficult-to-machine materials
such as austenitic steel particularly happened at higher cutting speeds
for the localization of plastic deformation in the shear plane and for
the inception of separate elements substantially continuous chips.
This leads to variations of cutting forces substantially greater than for
other types of steel.
Abstract: This study was aimed for investigating of
manufacturing high aluminum content Mg alloys using a horizontal
twin roll caster. Recently, weight saving has been key issues for lighter
transport equipments as well as electronic component parts. As
alternative materials to aluminum alloys, developing magnesium alloy
with higher strength has been expected. Normally high Aluminum
content Mg alloy has poor ductility and is difficult to be rolled because
of its high strength. However, twin roll casting process is suitable for
manufacturing wrought Mg alloys because materials can be cast
directly from molten metal. In this study, manufacturing of high
aluminum content magnesium alloy sheet using the roll casting
process has been carried out. Effects of manufacturing parameter, such
as roll velocity, pouring temperature and roll gap, on casting was
investigated. A microscopic observation of the crystals of cross section
of as cast strip as well as rolled strip was conducted.
Abstract: Among the many promising nanomaterials with antifungal properties, metal nanoparticles (silver nanoparticles) stand out due to their high chemical activity. Therefore, the aim of this study was to evaluate the effect of silver nanoparticles (AgNPs) against Phomopsis sp. AgNPs were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. The synthesized AgNPs have further been characterized by UV/Visible spectroscopy, Biophysical techniques like Dynamic light scattering (DLS) and Scanning Electron Microscopy (SEM). The average diameter of the prepared silver colloidal nanoparticles was about 52 nm. Absolute inhibitions (100%) were observed on treated with a 270 and 540 µg ml-1 concentration of AgNPs. The results from the study of the AgNPs antifungal effect are significant and suggest that the synthesized silver nanoparticles may have an advantage compared with conventional fungicides.
Abstract: Today, canines are still used effectively in acceleration detection situation. However, this method is becoming impractical in modern age and a new automated replacement to the canine is required. This paper reports the design of an innovative accelerant detector. Designing an accelerant detector is a long process as is any design process; therefore, a solution to the need for a mobile, effective accelerant detector is hereby presented. The device is simple and efficient to ensure that any accelerant detection can be conducted quickly and easily. The design utilizes Ultra Violet (UV) light to detect the accelerant. When the UV light shines on an accelerant, the hydrocarbons in the accelerant emit florescence. The advantages of using the UV light to detect accelerant are also outlined in this paper. The mobility of the device is achieved by using a Direct Current (DC) motor to run tank tracks. Tank tracks were chosen as to ensure that the device will be mobile in the rough terrain of a fire site. The materials selected for the various parts are also presented. A Solid Works Simulation was also conducted on the stresses in the shafts and the results are presented. This design is an innovative solution which offers a user friendly interface. The design is also environmentally friendly, ecologically sound and safe to use.
Abstract: This paper deals with the status of solid waste pollution in touristic spots of North coastal Andhra Pradesh. Case studies of Eco tourism, cultural tourism and pilgrim tourism are elaborately discussed and the study is based on both primary and secondary data. Data collection includes field collection of solid waste, semi structured interviews and observation of tourists. Results indicate generation of 72% Non biodegradable material in Eco touristic places like RK beach Visakhapatnam, Araku Valley. Pydithalli Jathra is a famous cultural touristic attraction and more than one lakh people converge here. The solid waste at this spot includes 20% coconut shells, 50% plastic bottles and covers, 20% Banana peelings and remaining are food materials. Radhasapthami is the most important festival celebrated at famous sun temple Arasavalli of Srikakulam. Here solid waste includes 50% water bottles, plastic covers, 10% papers, 10% hair, 30% left out food material and Banana peelings.
Abstract: An ordered porous antimony-doped tin oxide (ATO) film was successfully prepared using a simple coating process with colloidal templates. The facile production was effective when a combination of 16-nm ATO (as a model of an inorganic nanoparticle) and polystyrene (PS) spheres (as a model of the template) weresimply coated to produce a composite ATO/PS film. Heat treatment was then used to remove the PS and produce the porous film. The porous film with a spherical pore shape and a highly ordered porous structure could be obtained. A potential way for the control of pore size could be also achieved by changing initial template size. The theoretical explanation and mechanism of porous formation were also added, which would be important for the scaling-up prediction and estimation.
Abstract: Interaction of inorganic water-soluble salts and building stones is studied in the paper. Two types of sandstone and one type of spongillite as representatives of materials used in historical masonry are subjected to experimental testing. Within the performed experiments, measurement of moisture and chloride concentration profiles is done in order to get input data for computational inverse analysis. Using the inverse analysis, moisture diffusivity and chloride diffusion coefficient of investigated materials are accessed. Additionally, the effect of salt presence on water vapor storage is investigated using dynamic vapor sorption device. The obtained data represents valuable information for restoration of historical masonry and give evidence on the performance of studied stones in contact with water soluble salts.
Abstract: The predictability of masonry arch bridges and their
behaviour is widely considered doubtful due to the lack of knowledge
about the conditions of a given masonry arch bridge. The assessment
methods for masonry arch bridges are MEXE, ARCHIE, RING and
Frame Analysis Method. The material properties of the masonry and
fill material are extremely difficult to determine accurately.
Consequently, it is necessary to examine the effect of load dispersal
angle through the fill material, the effect of variations in the stiffness
of the masonry, the tensile strength of the masonry mortar continuum
and the compressive strength of the masonry mortar continuum. It is
also important to understand the effect of fill material on load
dispersal angle to determine their influence on ratings. In this paper a
series of parametric studies, to examine the sensitivity of assessment
ratings to the various sets of input data required by the frame analysis
method, are carried out.
Abstract: This paper studied the synthesis of monoacylglycerol (monolaurin) by glycerolysis of coconut oil and crude glycerol, catalyzed by Carica papaya lipase. Coconut oil obtained from cold pressed extraction method and crude glycerol obtained from the biodiesel plant in Department of Chemistry, Uttaradit Rajabhat University, Thailand which used oils were used as raw materials for biodiesel production through transesterification process catalyzed by sodium hydroxide. The influences of the following variables were studied: (i) type of organic solvent, (ii) molar ratio of substrate, (iii) reaction temperature, (iv) reaction time, (v) lipase dosage, and (vi) initial water activity of enzyme. High yields in monoacylglycerol (58.35%) were obtained with molar ratio of glycerol to oil at 8:1 in ethanol, temperature was controlled at 45oC for 36 hours, the amount of enzyme used was 20 wt% of oil and initial water activity of enzyme at 0.53.
Abstract: Ultrasonic machining (USM) is a non-traditional
machining process being widely used for commercial machining of
brittle and fragile materials such as glass, ceramics and
semiconductor materials. However, USM could be a viable
alternative for machining a tough material such as titanium; and this
aspect needs to be explored through experimental research. This
investigation is focused on exploring the use of ultrasonic machining
for commercial machining of pure titanium (ASTM Grade-I) and
evaluation of tool wear rate (TWR) under controlled experimental
conditions. The optimal settings of parameters are determined
through experiments planned, conducted and analyzed using Taguchi
method. In all, the paper focuses on parametric optimization of
ultrasonic machining of pure titanium metal with TWR as response,
and validation of the optimized value of TWR by conducting
confirmatory experiments.
Abstract: The aim of the article is to describe modern
contemporary systems of employees' remuneration used in
organizations, to give a general overview of these questions based on
the questionnaire survey made by the authors, as well as to assess
possible effects of economic crisis in this area. It is necessary to be
aware of the fact that firm's success in the contemporary business
environment depends not only on the technical equipment, financial
resources, availability of raw materials and information and effective
management, but one of the crucial factors of firm's success is its
human potential. The article emphasizes that the well working
remuneration system has a very important position in the
organization in the broadest sense. The paper also aims to the current
situation in the area of employees' remuneration in one of Czech
Republic regions, in the Moravian-Silesian Region.
Abstract: This paper describes analysis of low velocity transverse impact on fully backed sandwich beams with composite faces from Eglass/epoxy and cores from Polyurethane or PVC. Indentation on sandwich beams has been analyzed with the existing theories and modeled with the FE code ABAQUS, also loadings have been done experimentally to verify theoretical results. Impact on fully backed has been modeled in two cases of impactor energy with SDOF model (single-degree-of-freedom) and indentation stiffness: lower energy for elastic indentation of sandwich beams and higher energy for plastic area in indentation. Impacts have been modeled by ABAQUS. Impact results can describe response of beam in terms of core and faces thicknesses, core material, indentor energy and energy absorbed. The foam core is modeled using the crushable foam material model and response of the foam core is experimentally characterized in uniaxial compression with higher velocity loading to define quasi impact behaviour.
Abstract: Our results showed that for the growth of qualitative
seedling and vegetative raw material of ðó. marschallianus Willd. and
T. serphyllum L. it is more profitable to use the in vitro and
hydroponics combined method. In in vitro culture it is possible to do
micro-propagation whole year with 98-99% rhizogenesis. 30000
micro-plants were obtained from one explant during 9 months.
Hydroponic conditions provide the necessary microclimate for
microplants where the survival rate without acclimatization was
93.3%. The essential oil content in hydroponic dry herb of both
species in vegetative and blossom phase was 1.3% whereas in wild
plants it was 1.2%, the content of extractive substances and vitamin
C also exceeded wild plants. Our biochemical and radiochemical
investigations indicated that the medicinal raw materials obtained
from hydroponic and wild plants of Thymus species correspond to
the demands of SPh XI, and the content of artificial radionuclides
does not exceed the MACL.
Abstract: Semiconductor nanomaterials like TiO2 nanoparticles
(TiO2-NPs) approximately less than 100 nm in diameter have become
a new generation of advanced materials due to their novel and
interesting optical, dielectric, and photo-catalytic properties. With the
increasing use of NPs in commerce, to date few studies have
investigated the toxicological and environmental effects of NPs.
Motivated by the importance of TiO2-NPs that may contribute to the
cancer research field especially from the treatment prospective
together with the fractal analysis technique, we have investigated the
effect of TiO2-NPs on colony morphology in the dark condition
using fractal dimension as a key morphological characterization
parameter. The aim of this work is mainly to investigate the cytotoxic
effects of TiO2-NPs in the dark on the growth of human cervical
carcinoma (HeLa) cell colonies from morphological aspect. The in
vitro studies were carried out together with the image processing
technique and fractal analysis. It was found that, these colonies were
abnormal in shape and size. Moreover, the size of the control
colonies appeared to be larger than those of the treated group. The
mean Df +/- SEM of the colonies in untreated cultures was
1.085±0.019, N= 25, while that of the cultures treated with TiO2-NPs
was 1.287±0.045. It was found that the circularity of the control
group (0.401±0.071) is higher than that of the treated group
(0.103±0.042). The same tendency was found in the diameter
parameters which are 1161.30±219.56 μm and 852.28±206.50 μm
for the control and treated group respectively. Possible explanation of
the results was discussed, though more works need to be done in
terms of the for mechanism aspects. Finally, our results indicate that
fractal dimension can serve as a useful feature, by itself or in
conjunction with other shape features, in the classification of cancer
colonies.
Abstract: Scaffolds play a key role in tissue engineering and can be produced in many different ways depending on the applications and the materials used. Most researchers used an experimental trialand- error approach into new biomaterials but computer simulation applied to tissue engineering can offer a more exhaustive approach to test and screen out biomaterials. This paper develops the model of scaffolds and Computational Fluid Dynamics that show the value of computer simulations in determining the influence of the geometrical scaffold parameter porosity, pore size and shape on the permeability of scaffolds, magnitude of velocity, drop pressure, shear stress distribution and level and the proper design of the geometry of the scaffold. This creates a need for more advanced studies that include aspects of dynamic conditions of a micro fluid passing through the scaffold were characterized for tissue engineering applications and differentiation of tissues within scaffolds.
Abstract: The mechanical deformation and the electrical conductivity of lanthanum strontium cobalt ferrite oxide under uniaxial compression were investigated at various temperatures up to 1073 K. The material reveals a rather complex mechanical behaviour related to its ferroelasticity and completely different stress-strain curves are obtained during the 1st and 2nd loading cycles. A distinctive ferroelastic creep was observed at 293 K whilst typical ferroelastic stress-strain curve were obtained in the temperature range from 473 K to 873 K. At 1073 K, on the other hand, high-temperature creep deformation was observed instead of ferroelastic deformation. The conductivity increases with increasing compressive stress at all the temperatures. The increase in conductivity is related to both geometrical and piezoelectric effects. From 293 K to 873 K, where the material exhibits ferroelastic behaviour, the variation in the total conductivity decreases with increasing temperature. The contribution of the piezoelectric effect to the total conductivity variation also decreases with increasing temperature and the maximum in piezoconductivity has a value of about 0.75 % at 293 K for a compressive stress of 100 MPa. There is no effect of domain switching on conductivity except for the geometric effect. At 1073 K, the conductivity is simply proportional to the compressive strain.
Abstract: The main emphasis of metallurgists has been to process the materials to obtain the balanced mechanical properties for the given application. One of the processing routes to alter the properties is heat treatment. Nearly 90% of the structural applications are related to the medium carbon an alloyed steels and hence are regarded as structural steels. The major requirement in the conventional steel is to improve workability, toughness, hardness and grain refinement. In this view, it is proposed to study the mechanical and tribological properties of unalloyed structural (AISI 1140) steel with different thermal (heat) treatments like annealing, normalizing, tempering and hardening and compared with as brought (cold worked) specimen. All heat treatments are carried out in atmospheric condition. Hardening treatment improves hardness of the material, a marginal decrease in hardness value with improved ductility is observed in tempering. Annealing and normalizing improve ductility of the specimen. Normalized specimen shows ultimate ductility. Hardened specimen shows highest wear resistance in the initial period of slide wear where as above 25KM of sliding distance, as brought steel dominates the hardened specimen. Both mild and severe wear regions are observed. Microstructural analysis shows the existence of pearlitic structure in normalized specimen, lath martensitic structure in hardened, pearlitic, ferritic structure in annealed specimen.