Abstract: Thermodynamic properties of liquids under negative pressures are interesting and important in fields of scienceand technology. Here, phase transitions of a thermotropic liquid crystal are investigatedin a range from positive to negative pressures with a metal Berthelot tube using a commercial pressure transducer.Two co-existinglines, namely crystal (Kr) –nematic (N), and isotropic liquid (I) - nematic (N) lines, weredrawn in a pressure - temperature plane. The I-N line was drawn to ca. -5 (MPa).
Abstract: In industrial environments, the heat exchanger is a
necessary component to any strategy of energy conversion. Much of
thermal energy used in industrial processes passes at least one times
by a heat exchanger, and methods systems recovering thermal
energy.
This survey paper tries to presents in a systemic way an sample
control of a heat exchanger by comparison between three controllers
LQR (linear quadratic regulator), PID (proportional, integrator and
derivate) and Pole Placement. All of these controllers are used mainly
in industrial sectors (chemicals, petrochemicals, steel, food
processing, energy production, etc…) of transportation (automotive,
aeronautics), but also in the residential sector and tertiary (heating, air
conditioning, etc...) The choice of a heat exchanger, for a given
application depends on many parameters: field temperature and
pressure of fluids, and physical properties of aggressive fluids,
maintenance and space. It is clear that the fact of having an
exchanger appropriate, well-sized, well made and well used allows
gain efficiency and energy processes.
Abstract: The increasing penetration of Distributed Generation and storage connected to the distribution network via PWM converters increases the possibility of a DC-component (offset) in voltage or current flowing into the grid. This occurs when even harmonics are present in the network voltage. DC-components can affect the operation and safety of several grid components. Therefore, an investigation of the way they are produced is important in order to take appropriate measures for their elimination. Further research on DC-components that appear on output voltage of converters is performed for different parameters of PWM technique and characteristics of even harmonics.
Abstract: The adsorption efficiency of various adsorbents for the removal of Zn(II) ions from the waste printing developer was studied in laboratory batch mode. The maximum adsorption efficiency of 94.1% was achieved with unfired clay pellets size (d ≈ 15 mm). The obtained values of adsorption efficiency was subjected to the independent-samples t test in order to investigate the statistically significant differences of the investigated adsorbents for the effective removal of Zn(II) ions from the waste printing developer. The most statistically significant differences of adsorption efficiencies for Zn(II) ions removal were obtained between unfired clay pellets (size d ≈ 15 mm) and activated carbon (½t½=6.909), natural zeolite (½t½=10.380), mixture of activated carbon and natural zeolite (½t½=9.865), bentonite (½t½=6.159), fired clay (½t½=6.641), fired clay pellets (size d ≈ 5 mm) (½t½=6.678), fired clay pellets (size d ≈ 8 mm) (½t½=3.422), respectively.
Abstract: Local utilities often face problems of local industrial
wastes, storm water disposal due to existing strict regulations. For
many local industries, the problem of wastewater treatment and
discharge into surface reservoirs can’t be solved through the use of
conventional biological treatment techniques. Current discharge
standards require very strict removal of a number of impurities such
as ammonia, nitrates, phosphate, etc. To reach this level of removal,
expensive reagents and sorbents are used.
The modern concept of rational water resources management
requires the development of new efficient techniques that provide
wastewater treatment and reuse.
As RO membranes simultaneously reject all dissolved impurities
such as BOD, TDS, ammonia, phosphates etc., they become very
attractive for the direct treatment of wastewater without biological
stage. To treat wastewater, specially designed membrane "open
channel" modules are used that do not possess "dead areas" that cause
fouling or require pretreatment. A solution to RO concentrate
disposal problem is presented that consists of reducing of initial
wastewater volume by 100 times. Concentrate is withdrawn from
membrane unit as sludge moisture. The efficient use of membrane
RO techniques is connected with a salt balance in water system.
Thus, to provide high ecological efficiency of developed techniques,
all components of water supply and wastewater discharge systems
should be accounted for.
Abstract: The aluminum impregnated catalysts of Al-alumina (Al-Al2O3), Al-montmorillonite (Al-Mmn) and Al-activated charcoal (Al-AC) of various percent loadings were prepared by wet impregnation method and characterized by SEM, XRD and N2 adsorption/desorption (BET). The catalytic properties were investigated in the degradation of waste polystyrene (WPS). The results of catalytic degradation of Al metal, 20% Al-Al2O3, 5% Al-Mmn and 20% Al-AC were compared with each other for optimum conditions. Among the catalyst used 20% Al-Al2O3 was found the most effective catalyst. The BET surface area of 20% Al-Al2O3 determined was 70.2 m2/g. The SEM data revealed the catalyst with porous structure throughout the frame work with small nanosized crystallites. The yield of liquid products with 20% Al-Al2O3 (91.53 ± 2.27 wt%) was the same as compared to Al metal (91.20 ± 0.35 wt%) but the selectivity of hydrocarbons and yield of styrene monomer (56.32 wt%) was higher with 20% Al-Al2O3 catalyst.
Abstract: This study focuses on the application of sensory thermography, as a non-invasive method to evaluate the musculoskeletal injuries that industry workers performing Highly Repetitive Movements (HRM) may acquire. It was made at a wireless company having the target of analyze temperatures in worker’s wrists, elbows and shoulders in workstations during their activities, this thru sensorial thermography with the goal of detecting maximum temperatures (Tmax) that could indicate possible injuries. The tests were applied during 3 hours for only 2 workers that work in workstations where there’s been the highest index of injuries and accidents. We were made comparisons for each part of the body that were study for both because of the similitude between the activities of the workstations; they were requiring both an immediate evaluation. The Tmax was recorder during the test of the worker 2, in the left wrist, reaching a temperature of 35.088ºC and with a maximum increase of 1.856°C
Abstract: In this study, we developed a complementary electrochromic device consisting of WO3 and NiO films fabricated by rf-magnetron sputtered. The electrochromic properties of WO3 and NiO films were investigated using cyclic voltammograms (CV), performed on WO3 and NiO films immersed in an electrolyte of 1 M LiClO4 in propylene carbonate (PC). Optical and electrochemical of the films, as a function of coloration–bleaching cycle, were characterized using an UV-Vis-NIR spectrophotometer and cyclic voltammetry (CV). After investigating the properties of WO3 film, NiO film, and complementary electrochromic devices, we concluded that this device provides good reversibility, low power consumption of -2.5 V in color state, high variation of transmittance of 58.96%, changes in optical density of 0.81 and good memory effect under open-circuit conditions. In addition, electrochromic component penetration rate can be retained below 20% within 24h, showing preferred memory features; however, component coloring and bleaching response time are about 33s.
Abstract: In this study, the Mo-electrode thin films were deposited using two-stepped process and the high purity copper indium selenide-based powder (CuInSe2, CIS) was fabricated by using hydrothermal process by Nanowin Technology Co. Ltd. Because the CIS powder was aggregated into microscale particles, the CIS power was ground into nano-scale particles. 6 wt% CIS particles were mixed and dispersed into isopropyl alcohol (IPA). A new non-vacuum thin-film deposition process, spray coating method (SPM), was investigated to deposit the high-densified CIS absorber layers. 0.1 ml CIS solution was sprayed on the 20 mm×10 mm Mo/glass substrates and then the CuInSe2 thin films were annealed in a selenization furnace using N2 as atmosphere. The annealing temperature and time were set at 550oC and 5 min, and 0.0g~0.6g extra Se content was added in the furnace. The influences of extra Se content on the densification, crystallization, resistivity (ρ), hall mobility (μ), and carrier concentration of the CIS absorber layers were well investigated in this study.
Abstract: In this study, we investigated (In,Ga,Zn)Ox (IGZO) thin films and examined their characteristics of using Ga2O3-2 ZnO (GZO) co-sputtered In2O3 prepared by dual target radio frequency magnetron sputtering at room temperature in a pure Ar atmosphere. RF powers of 80 W and 70 W were used for GZO and pure In2O3, room temperature (RT) was used as deposition temperature, and the deposition time was changed from 15 min to 60 min. Structural, surface, electrical, and optical properties of IGZO thin films were investigated as a function of deposition time. Furthermore, the GZO co-sputtered In2O3 thin films showed a very smooth and featureless surface and an amorphous structure regardless of the deposition time due to the room temperature sputtering process. We would show that the co-sputtered IGZO thin films exhibited transparent electrode properties with high transmittance ratio and low resistivity.
Abstract: To avoid battery assisted tags with limited lifetime batteries, it is proposed here to replace them by energy harvesting
systems, able to feed from local environment. This would allow total
independence to RFID systems, very interesting for applications
where tag removal from its location is not possible. Example is here
described for luggage safety in airports, and is easily extendable to similar situation in terms of operation constraints. The idea is to fix
RFID tag with energy harvesting system not only to identify luggage
but also to supply an embedded microcontroller with a sensor
delivering luggage weight making it impossible to add or to remove
anything from the luggage during transit phases. The aim is to
optimize the harvested energy for such RFID applications, and to
study in which limits these applications are theoretically possible.
Proposed energy harvester is based on two energy sources:
piezoelectricity and electromagnetic waves, so that when the luggage
is moving on ground transportation to airline counters, the piezo
module supplies the tag and its microcontroller, while the RF module
operates during luggage transit thanks to readers located along the
way. Tag location on the luggage is analyzed to get best vibrations, as
well as harvester better choice for optimizing the energy supply
depending on applications and the amount of energy harvested during
a period of time. Effects of system parameters (RFID UHF
frequencies, limit distance between the tag and the antenna necessary
to harvest energy, produced voltage and voltage threshold) are
discussed and working conditions for such system are delimited.
Abstract: This paper aims to study the role and activities of the participants and the impact of activities created in the local area in order to sustainably develop the local areas. This study applied both qualitative and quantitative approaches presented in descriptive style; the data was collected via survey, observation and in-depth interviews with samples. The results illustrated five sorts of roles of participants of the Cicada Walking-street and four types of creative activities; recreation based, art based, cultural based, and live events. Integration of local characteristics, arts and cultures were presented creatively and interestingly. Participants are various. The roles of the participants found in the Cicada Market are group of the property and area management, entrepreneurs, leisure (entertaining persons), local people, and tourists. The good impacts on local communities are those in terms of economy, environmental friendly and local arts and cultures promoting. On the other hand, the traffic congestion, waste and the increasing of energy consumption are negative impacts from area development.
Abstract: Using the technology acceptance model (TAM), this
study examined the external variables of technological complexity
(TC) to acquire a better understanding of the factors that influence the
acceptance of computer application courses by learners at Active
Aging Universities. After the learners in this study had completed a
27-hour Facebook course, 44 learners responded to a modified TAM
survey. Data were collected to examine the path relationships among
the variables that influence the acceptance of Facebook-mediated
community learning. The partial least squares (PLS) method was used
to test the measurement and the structural model. The study results
demonstrated that attitudes toward Facebook use directly influence
behavioral intentions (BI) with respect to Facebook use, evincing a
high prediction rate of 58.3%. In addition to the perceived usefulness
(PU) and perceived ease of use (PEOU) measures that are proposed in
the TAM, other external variables, such as TC, also indirectly
influence BI. These four variables can explain 88% of the variance in
BI and demonstrate a high level of predictive ability. Finally,
limitations of this investigation and implications for further research
are discussed.
Abstract: This paper proposes a new method to find the equations
of transformation matrix for the rotation angles of the two rotational
axes and the coordinates of the three linear axes of an orthogonal
multi-axis milling machine. This approach provides intuitive physical
meanings for rotation angles of multi-axis machines, which can be
used to evaluate the accuracy of the conversion from CL data to NC
data.
Abstract: This paper carries out a performance analysis based on
the first and second laws of thermodynamics for heat recovery vapor
generator (HRVG) of ammonia-water mixture when the heat source is
low-temperature energy in the form of sensible heat. In the analysis,
effects of the ammonia mass concentration and mass flow ratio of the
binary mixture are investigated on the system performance including
the effectiveness of heat transfer, entropy generation, and exergy
efficiency. The results show that the ammonia concentration and the
mass flow ratio of the mixture have significant effects on the system
performance of HRVG.
Abstract: In this paper, a sliding mode control method based on the passivity approach is proposed to control the position of surface-mounted permanent magnet synchronous motors (PMSMs). Firstly, the dynamics of a PMSM was proved to be strictly passive. The position controller with an adaptive law was used to estimate the load torque to eliminate the chattering effects associated with the conventional sliding mode controller. The stability analysis of the overall position control system was carried out by adopting the passivity theorem instead of Lyapunov-type arguments. Finally, experimental results were provided to show that the good position tracking can be obtained, and exhibit robustness in the variations of the motor parameters and load torque disturbances.
Abstract: This research intended to develop the model of community management for sustainable utilization by investigating on 2 groups of population, the family heads and the community management team. The population of the former group consisted of family heads from 511 families in 12 areas to complete the questionnaires which were returned at 479 sets. The latter group consisted of the community management team of 12 areas with 1 representative from each area to give the interview. The questionnaires for the family heads consisted of 2 main parts; general information such as occupations, etc. in the form of checklist. The second part dealt with the data on self reliance community development based on 4P Framework, i.e., People (human resource) development, Place (area) development, Product (economic and income source) development, and Plan (community plan) development in the form of rating scales. Data in the 1st part were calculated to find frequency and percentage while those in the 2nd part were analyzed to find arithmetic mean and SD. Data from the 2nd group of population or the community management team were derived from focus group to find factors influencing successful management together with the in depth interview which were analyzed by descriptive statistics. The results showed that 479 family heads reported that the aspect on the implementation of community plan to self reliance community activities based on Sufficient Economy Philosophy and the 4P was at the average of 3.28 or moderate level. When considering in details, it was found that the 1st aspect was on the area development with the mean of 3.71 or high level followed by human resource development with the mean of 3.44 or moderate level, then, economic and source of income development with the mean of 3.09 or moderate level. The last aspect was community plan development with the mean of 2.89. The results from the small group discussion revealed some factors and guidelines for successful community management as follows: 1) on the People (human resource) development aspect, there was a project to support and develop community leaders. 2) On the aspect of Place (area) development, there was a development on conservative tourism areas. 3) On the aspect of Product (economic and source of income) development, the community leaders promoted the setting of occupational group, saving group, and product processing group. 4) On the aspect of Plan (community plan) development, there was a prioritization through public hearing.
Abstract: This research aims to study the species, feeding behavior and activity characteristics of birds which reap benefits from the research area in boat touring routes in Klong Kone Sub-district, Muang District, Samut Songkram Province, Thailand from October 2013 – May 2014. The results from the survey of birds on all three routes found that there are 11 families and 22 species. Route 1 (Klong Kone canal) had the most species, 20 species. According to feeding behavior, there were insectivorous, piscivorous and aquatic invertebrate feeder birds. Activity characteristics of birds which reap benefits from the research were finding food, nesting and raise nestlings along boat touring routes.
Abstract: This research aims to study species, abundance, status
of birds, the similarities and activity characteristics of birds which
reap benefits from the research area in boat touring routes in Tha Ka
sub-district, Amphawa District, Samut Songkram Province, Thailand.
from October 2012 – September 2013. The data was analyzed to find
the abundance, and similarity index of the birds. The results from the
survey of birds on all three routes found that there are 33 families and
63 species. Route 3 (traditional coconut sugar making kiln – resort)
had the most species; 56 species. There were 18 species of commonly
found birds with an abundance level of 5, which calculates to 28.57%
of all bird species. In August, 46 species are found, being the greatest
number of bird species benefiting from this route. As for the status of
the birds, there are 51 resident birds, 7 resident and migratory birds,
and 5 migratory birds. On Route 2 and Route 3, the similarity index
value is equal to 0.881. The birds are classified by their activity
characteristics i.e. insectivore, piscivore, granivore, nectrivore and
aquatic invertebrate feeder birds. Some birds also use the area for
nesting.
Abstract: The objectives of this research were to develop and find the efficiency of integrated online lessons by investigating the usage of online lessons, the relationship between learners’ background knowledge, and the achievement after learning with online lessons. The sample group in this study consisted of 97 students randomly selected from 121 students registering in 1/2012 at Trimitwittayaram Learning Center. The sample technique employed stratified sample technique of 4 groups according to their proficiency, i.e. high, moderate, low, and non-knowledge. The research instrument included online lessons in integration model on the topic of Java Programming, test after each lesson, the achievement test at the end of the course, and the questionnaires to find learners’ satisfaction. The results showed that the efficiency of online lessons was 90.20/89.18 with the achievement of after learning with the lessons higher than that before the lessons at the statistically significant level of 0.05. Moreover, the background knowledge of the learners on the programming showed the positive relationship with the achievement learning at the statistically significant level at 0.05. Learners with high background knowledge employed less exercises and samples than those with lower background knowledge. While learners with different background in the group of moderate and low did not show the significant difference in employing samples and exercises.