Abstract: The aim of the present work was to test in vitro inhibition of food pathogens and spoilage bacteria by crude bacteriocins from autochthonous lactic acid bacteria. Thirty autochthonous lactic acid bacteria isolated previously, belonging to the genera: Lactobacillus, Carnobacterium, Lactococcus, Vagococcus, Streptococcus, and Pediococcus, have been screened by an agar spot test and a well diffusion assay against Gram-positive and Gram-negative harmful bacteria: Bacillus cereus, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 6538, and Pseudomonas aeruginosa under conditions means to reduce lactic acid and hydrogen peroxide effect to select bacteria with high bacteriocinogenic potential. Furthermore, crude bacteriocins semiquantification and heat sensitivity to different temperatures (80, 95, 110°C, and 121°C) were performed. Another exploratory test concerning the response of St. aureus ATCC 6538 to the presence of crude bacteriocins was realized. It has been observed by the agar spot test that fifteen candidates were active toward Gram-positive targets strains. The secondary screening demonstrated an antagonistic activity oriented only against St. aureus ATCC 6538, leading to the selection of five isolates: Lm14, Lm21, Lm23, Lm24, and Lm25 with a larger inhibition zone compared to the others. The ANOVA statistical analysis reveals a small variation of repeatability: Lm21: 0.56%, Lm23: 0%, Lm25: 1.67%, Lm14: 1.88%, Lm24: 2.14%. Conversely, slight variation was reported in terms of inhibition diameters: 9.58± 0.40, 9.83± 0.46 and 10.16± 0.24 8.5 ± 0.40 10 mm for, Lm21, Lm23, Lm25, Lm14and Lm24, indicating that the observed potential showed a heterogeneous distribution (BMS = 0.383, WMS = 0.117). The repeatability coefficient calculated displayed 7.35%. As for the bacteriocins semiquantification, the five samples exhibited production amounts about 4.16 for Lm21, Lm23, Lm25 and 2.08 AU/ml for Lm14, Lm24. Concerning the sensitivity the crude bacteriocins were fully insensitive to heat inactivation, until 121°C, they preserved the same inhibition diameter. As to, kinetic of growth , the µmax showed reductions in pathogens load for Lm21, Lm23, Lm25, Lm14, Lm24 of about 42.92%, 84.12%, 88.55%, 54.95%, 29.97% in the second trails. Inversely, this pathogen growth after five hours displayed differences of 79.45%, 12.64%, 11.82%, 87.88%, 85.66% in the second trails, compared to the control. This study showed potential inhibition to the growth of this food pathogen, suggesting the possibility to improve the hygienic food quality.
Abstract: Sand cast samples of the as-received 66/34Mg-Al alloy were first homogenized at 4900C and then divided into three groups on which annealing, normalising and artificial ageing were respectively carried out. Thermal ageing of the samples involved treatment at 5000C, soaked for 4 hours and quenched in water at ambient temperature followed by tempering at 2000C for 2 hours. Test specimens were subjected to microstructure and mechanical analyses and the results compared. Precipitation of significant volume of stable Mg17Al12 crystals in the aged specimen’s matrix conferred superior mechanical characteristics compared with the annealed, normalized and as-cast specimens. The ultimate tensile strength was 93.4MPa with micro-hardness of 64.9HRC and impact energy (toughness) of 4.05J. In particular, its Young modulus was 10.4GPa which compared well with that of cortical (trabecule) bone’s modulus that varies from 12-17GPa.
Abstract: Evaluating the efficiency of decision making units has been frequently elaborated on in numerous publications. In this paper, the theoretical framework for a novel method of Distance Based Analysis (DBA) is presented. In addition, the method is performed on a sample of the ARWU’s top 54 Universities of the United States; the findings of which clearly demonstrate that the best ranked Universities are far from also being the most efficient.
Abstract: The development of an low cost acquisition system of S-EMG signals which are reliable, comfortable for the user and with high mobility shows to be a relevant proposition in modern biomedical engineering scenario. In the study, the sampling capacity of the Arduino microcontroller Atmel Atmega328 with an A / D converter with 10-bit resolution and its reconstructing capability of a signal of surface electromyography is analyzed. An electronic circuit to capture the signal through two differential channels was designed, signals from Biceps Brachialis of a healthy man of 21 years was acquired to test the system prototype. ARV, MDF, MNF and RMS estimators were used to compare de acquired signals with physiological values. The Arduino was configured with a sampling frequency of 1.5kHz for each channel, and the tests with the circuit designed offered a SNR of 20.57dB.
Abstract: The calcarenites carbonate rocks of the Quaternary ridges, which extend along the northwestern Mediterranean coastal plain of Egypt, represent an excellent model for the transformation of loose sediments to real sedimentary rocks by the different stages of meteoric diagenesis. The depositional and diagenetic fabrics of the rocks, in addition to the strata orientation, highly affect their ultimate compressive strength and other geotechnical properties.
There is a marked increase in the compressive strength (UCS) from the first to the fourth ridge rock samples. The lowest values are related to the loose packing, weakly cemented aragonitic ooid sediments with high porosity, besides the irregularly distributed of cement, which result in decreasing the ability of these rocks to withstand crushing under direct pressure. The high (UCS) values are attributed to the low porosity, the presence of micritic cement, the reduction in grain size and the occurrence of micritization and calcretization processes.
The strata orientation has a notable effect on the measured (UCS). The lowest values have been recorded for the samples cored in the inclined direction; whereas the highest values have been noticed in most samples cored in the vertical and parallel directions to bedding plane. In case of the inclined direction, the bedding planes were oriented close to the plane of maximum shear stress. The lowest and highest anisotropy values have been recorded for the first and the third ridges rock samples, respectively, which may attributed to the relatively homogeneity and well sorted grainstone of the first ridge rock samples, and relatively heterogeneity in grain and pore size distribution and degree of cementation of the third ridge rock samples, besides, the abundance of shell fragments with intraparticle pore spaces, which may produce lines of weakness within the rock.
Abstract: This investigation presents preparation of sample and
analysis of results of ballistic impact test as per EN 1063 on the size,
thickness, number, position, and type of the bonding interlayer
Polyvinyl Butyral, Poly Carbonate and Poly Urethane on bullet proof
glass. It was observed that impact energy absorbed by bullet proof
glass increases with the increase of the total thickness from 33mm to
42mm to 51mm for all the three samples respectively. Absorption
impact energy is greater for samples with more number of bonding
interlayers than with the number of glass layers for uniform increase
in total sample thickness. There is no effect on the absorption impact
energy with the change in position of the bonding interlayer.
Abstract: Asymmetric incremental sheet forming (AISF) could significantly reduce costs incurred by the fabrication of complex industrial components with a minimal environmental impact. The AISF experiments were carried out on commercially pure titanium (Ti-Gr2), Timetal (15-3-3-3) alloy, and Ti-6Al-4V (Ti-Gr5) alloy. A special testing geometry was used to characterize the titanium alloys properties from the point of view of the forming zone and titanium structure effect. The structure and properties of the materials were assessed by means of metallographic analyses and microhardness measurements.The highest differences in the parameters assessed as a function of the sampling zone were observed in the case of alpha-phase Ti-Gr2at the expense of the most substantial sheet thinning occurrence. A springback causes a smaller stored deformation in Timetal (β alloy) resulting in less pronounced microstructure refinement and microhardness increase. Ti-6Al-4V alloy exhibited early failure due to its poor formability at ambient temperature.
Abstract: The results of the study on the project evaluation to
develop the competencies, capabilities, and skills in repairing
computers of people in Jompluak Local Municipality, Bang Khonthi
District, Samut Songkram Province showed that the overall result
was good (4.33). When considering on each aspect, it was found that
the highest one was on process evaluation (4.60) followed by product
evaluation (4.50) and the least one was on feeding factor (3.97).
When considering in details, it was found that: 1) the context aspect
was high (4.23) with the highest item on the arrangement of the
training situation (4.67) followed by the appropriateness of the target
(4.30) and the least aspect was on the project cooperation (3.73). 2)
The evaluation of average overall primary factor or feeding factor
showed high value (4.23) while the highest aspect was on the
capability of the trainers (4.47) followed by the suitable venue (4.33)
while the least aspect was on the insufficient budget (3.47). 3) The
average result of process evaluation was very high (4.60). The
highest aspect was on the follow-op supervision (4.70) followed by
responsibility of each project staffs (4.50) while the least aspect was
on the present situation and the problems of the community (4.40). 4)
The overall result of the product evaluation was very high (4.50). The
highest aspect was on the diversity of the activities and the
community integration (4.67) followed by project target achievement
(4.63) while the least aspect was on continuation and regularity of the
activities (4.33). The trainees reported high satisfaction on the project
management at very high level (43.33%) while 40% reported high
level and 16.67% reported moderate level. Suggestions for the project
were on the additional number of the computer sets (37.78%)
followed by longer training period especially on computer skills
(43.48%).
Abstract: A thin gold metal layer was deposited on the top of
silicon oxide films containing embedded Si nanocrystals (Si-nc). The
sample was annealed in a gas containing nitrogen, and subsequently
characterized by photoluminescence. We obtained 3-fold
enhancement of photon emission from the Si-nc embedded in silicon
dioxide covered with a Gold layer as compared with an uncovered
sample. We attribute this enhancement to the increase of the
spontaneous emission rate caused by the coupling of the Si-nc
emitters with the surface plasmons (SP). The evolution of PL
emission with laser irradiated time was also collected from covered
samples, and compared to that from uncovered samples. In an
uncovered sample, the PL intensity decreases with time,
approximately with two decay constants. Although the decrease of
the initial PL intensity associated with the increase of sample
temperature under CW pumping is still observed in samples covered
with a gold layer, this film significantly contributes to reduce the
permanent deterioration of the PL intensity. The resistance to
degradation of light-emitting silicon nanocrystals can be increased by
SP coupling to suppress the permanent deterioration. Controlling the
permanent photodeterioration can allow to perform a reliable optical
gain measurement.
Abstract: The outstanding mechanical properties of Carbon
nanotubes (CNTs) have generated great interest for their potential as
reinforcements in high performance cementitious composites. The
main challenge in research is the proper dispersion of carbon
nanotubes in the cement matrix. The present work discusses the role
of dispersion of multiwalled carbon nanotubes (MWCNTs) on the
compressive strength characteristics of hydrated Portland IS 1489
cement paste. Cement-MWCNT composites with different mixing
techniques were prepared by adding 0.2% (by weight) of MWCNTs
to Portland IS 1489 cement. Rectangle specimens of size
approximately 40mm × 40mm ×160mm were prepared and curing of
samples was done for 7, 14, 28 and 35days. An appreciable increase
in compressive strength with both techniques; mixture of MWCNTs
with cement in powder form and mixture of MWCNTs with cement
in hydrated form 7 to 28 days of curing time for all the samples was
observed.
Abstract: The objectives of this research were to study the management of local towns and to develop a better model of town management according to the Philosophy of Sufficiency Economy. This study utilized qualitative research, field research, as well as documentary research at the same time. A total of 10 local towns or Tambons of Supanburi province, Thailand were selected for an in-depth interview. The findings revealed that the model of local town management according to Philosophy of Sufficient Economy was in a level of “good” and the model of management has the five basic guidelines: 1) ability to manage budget information and keep it up-to-date, 2) ability to decision making according to democracy rules, 3) ability to use check and balance system, 4) ability to control, follow, and evaluation, and 5) ability to allow the general public to participate. In addition, the findings also revealed that the human resource management according to Philosophy of Sufficient Economy includes obeying laws, using proper knowledge, and having integrity in five areas: plan, recruit, select, train, and maintain human resources.
Abstract: The two primary objectives of this research were (1)
to examine the current knowledge and actual circumstance of
agricultural workers about mangosteen product processing; and (2) to
analyze and evaluate ways to develop capacity of mangosteen
product processing. The population of this study was 15,125 people
who work in the agricultural sector, in this context, mangosteen
production, in the eastern part of Thailand that included Chantaburi
Province, Rayong Province, Trad Province and Pracheenburi
Province. The sample size based on Yamane’s calculation with 95%
reliability was therefore 392 samples. Mixed method was employed
included questionnaire and focus group discussion with
Connoisseurship Model used in order to collect quantitative and
qualitative data. Key informants were used in the focus group
including agricultural business owners, academic people in agro food
processing, local academics, local community development staff,
OTOP subcommittee, and representatives of agro processing
industry professional organizations. The study found that the
majority of the respondents agreed with a high level (in five- rating
scale) towards most of variables of knowledge management in agro
food processing. The result of the current knowledge and actual
circumstance of agricultural human resource in an arena of
mangosteen product processing revealed that mostly, the respondents
agreed at a high level to establish 7 variables. The guideline to
developing the body of knowledge in order to enhance the capacity
of the agricultural workers in mangosteen product processing was
delivered in the focus group discussion. The discussion finally
contributed to an idea to produce manuals for mangosteen product
processing methods, with 4 products chosen: (1) mangosteen soap;
(2) mangosteen juice; (3) mangosteen toffee; and (4) mangosteen
preserves or jam.
Abstract: Slab sliding system (SSS) with Coulomb friction
interface between slab and supporting frame is a passive structural
vibration control technology. The system can significantly reduce the
slab acceleration and accompanied lateral force of the frame. At the
same time it is expected to cause the slab displacement magnification
by sliding movement. To obtain the general comprehensive seismic
response of a single story structure, inelastic response spectra were
computed for a large ensemble of ground motions and a practical range
of structural periods and friction coefficient values. It was shown that
long period structures have no trade-off relation between force
reduction and displacement magnification with respect to elastic
response, unlike short period structures. For structures with the
majority of mass in the slab, the displacement magnification value can
be predicted according to simple inelastic displacement relation for
inelastically responding SDOF structures because the system behaves
elastically to a SDOF structure.
Abstract: Industries using conventional fossil fuels have an
interest in better understanding the mechanism of particulate
formation during combustion since such is responsible for emission
of undesired inorganic elements that directly impact the atmospheric
pollution level. Fine and ultrafine particulates have tendency to
escape the flue gas cleaning devices to the atmosphere. They also
preferentially collect on surfaces in power systems resulting in
ascending in corrosion inclination, descending in the heat transfer
thermal unit, and severe impact on human health. This adverseness
manifests particularly in the regions of world where coal is the
dominated source of energy for consumption.
This study highlights the behavior of calcium transformation as
mineral grains verses organically associated inorganic components
during pulverized coal combustion. The influence of existing type of
calcium on the coarse, fine and ultrafine mode formation mechanisms
is also presented. The impact of two sub-bituminous coals on particle
size and calcium composition evolution during combustion is to be
assessed. Three mixed blends named Blends 1, 2, and 3 are selected
according to the ration of coal A to coal B by weight. Calcium
percentage in original coal increases as going from Blend 1 to 3.
A mathematical model and a new approach of describing
constituent distribution are proposed. Analysis of experiments of
calcium distribution in ash is also modeled using Poisson distribution.
A novel parameter, called elemental index λ, is introduced as a
measuring factor of element distribution.
Results show that calcium in ash that originally in coal as mineral
grains has index of 17, whereas organically associated calcium
transformed to fly ash shown to be best described when elemental
index λ is 7.
As an alkaline-earth element, calcium is considered the
fundamental element responsible for boiler deficiency since it is the
major player in the mechanism of ash slagging process. The
mechanism of particle size distribution and mineral species of ash
particles are presented using CCSEM and size-segregated ash
characteristics. Conclusions are drawn from the analysis of
pulverized coal ash generated from a utility-scale boiler.
Abstract: Urban road dust comprises of a range of potentially
toxic metal elements and plays a critical role in degrading urban
receiving water quality. Hence, assessing the metal composition and
concentration in urban road dust is a high priority. This study
investigated the variability of metal composition and concentrations
in road dust in 4 different urban land uses in Gold Coast, Australia.
Samples from 16 road sites were collected and tested for selected 12
metal species. The data set was analyzed using both univariate and
multivariate techniques. Outcomes of the data analysis revealed that
the metal concentrations inroad dust differs considerably within and
between different land uses. Iron, aluminum, magnesium and zinc are
the most abundant in urban land uses. It was also noted that metal
species such as titanium, nickel, copper and zinc have the highest
concentrations in industrial land use. The study outcomes revealed
that soil and traffic related sources as key sources of metals deposited
on road surfaces.
Abstract: In this paper, a numerical algorithm using a coupled Galerkin-Differential Quadrature (DQ) method is proposed for the solution of dam-reservoir interaction problem. The governing differential equation of motion of the dam structure is discretized by the Galerkin method and the DQM is used to discretize the fluid domain. The resulting systems of ordinary differential equations are then solved by the Newmark time integration scheme. The mixed scheme combines the simplicity of the Galerkin method and high accuracy and efficiency of the DQ method. Its accuracy and efficiency are demonstrated by comparing the calculated results with those of the existing literature. It is shown that highly accurate results can be obtained using a small number of Galerkin terms and DQM sampling points. The technique presented in this investigation is general and can be used to solve various fluid-structure interaction problems.
Abstract: The Proton Exchange Membranes (PEM) are largely studied because they operate at low temperatures and they are suitable for mobile applications. However, there are some deficiencies in their operation, mainly those that use ethanol as a hydrogen source, that require a certain attention. Therefore, this research aimed to develop Nafion® composite membranes, mixing clay minerals, kaolin and halloysite to the polymer matrix in order to improve the ethanol molecule retentions and, at the same time, to keep the system’s protonic conductivity. The modified Nafion/Kaolin, Nafion/Halloysite composite membranes were prepared in weight proportion of 0.5, 1.0 and 1.5. The membranes obtained were characterized as to their ethanol permeability, protonic conductivity and water absorption. The composite morphology and structure are characterized by SEM and EDX and the thermal behavior is determined by TGA and DSC. The analysis of the results shows ethanol permeability reduction from 48% to 63%. However, the protonic conductivity results are lower in relation to pure Nafion®. As to the thermal behavior, the Nafion® composite membranes were stable up to a temperature of 325ºC.
Abstract: Climate considerations are essential dimensions in the assessment of thermal comfort and indoor environments inside Egyptian housing. The primary aim of this paper is to analyze the indoor environment of new housing in the new city of Assiut in the Southern Upper Egypt zone, in order to evaluate its thermal environment and determine the acceptable indoor operative temperatures. The psychrometric charts for ASHRAE Standard 55 and ACS used in this study would facilitate an overall representation of the climate in one of the hottest months in the summer season. This study helps to understand and deal with this problem and work on a passive cooling ventilation strategy in these contexts in future studies. The results that demonstrated the indoor temperature is too high, ranges between 31°C to 40°C in different natural ventilation strategies. This causes the indoor environment to be far from the optimum comfort operative temperature of ACS except when using air conditioners. Finally, this study is considered a base for developing a new system using natural ventilation with passive cooling strategies.
Abstract: We present in this work the performances of a mobile omnidirectional robot through evaluating its management of the redundancy of actuation. Thus we come to the predictive control implemented.
The distribution of the wringer on the robot actions, through the inverse pseudo of Moore-Penrose, corresponds to a « geometric ›› distribution of efforts. We will show that the load on vehicle wheels would not be equi-distributed in terms of wheels configuration and of robot movement.
Thus, the threshold of sliding is not the same for the three wheels of the vehicle. We suggest exploiting the redundancy of actuation to reduce the risk of wheels sliding and to ameliorate, thereby, its accuracy of displacement. This kind of approach was the subject of study for the legged robots.
Abstract: This review paper aims at understanding the importance of implementing sustainable green practices in the current hotel industry and the perception of the same from the point of view of the customers as well as the industry experts. Many hotels have benefited from green management such as enhanced reputation of the firm and more worth customers. For the business standing, it reduces business’s cost for posting advertisements and the clear hotel’s orientation shows hotels’ positive image which might increase employees’ recognition toward the business. Sustainability in business is the growth in lively processes which enable people to understand the potential to protect the Earth’s existent support systems. Well, looking to the future today’s green concerns will definitely become facet of more synchronized business environment, perhaps the concerns discussed in this study, may exchange a few words which hotels may consider in near future to widen awareness and improve business model.