Search results for: temperature profile

Authors: Pakize Neslihan Taslı, Alev Cumbul, Gul Merve Yalcın, Fikrettin Sahin

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A key experimental trial in the regeneration of large oral and craniofacial defects is the neogenesis of osseous and ligamentous interfacial structures. Currently, oral regenerative medicine strategies are unpredictable for repair of tooth supporting tissues destroyed as a consequence of trauma, chronic infection or surgical resection. A different approach combining the gel-casting method with Hydroxy Apatite HA-based scaffold and different cell lineages as a hybrid system leads to successively mimic the early stage of tooth development, in vitro. HA is widely accepted as a bioactive material for guided bone and tooth regeneration. In this study, it was reported that, HA porous scaffold preparation, characterization and evaluation of structural and chemical properties. HA is the main factor that exists in tooth and it is in harmony with structural, biological, and mechanical characteristics. Here, this study shows mimicking immature tooth at the late bell stage design and construction of HA scaffolds for cell transplantation of human Adipose Stem Cells (hASCs), human Bone Marrow Stem Cells (hBMSCs) and Gingival Epitelial cells for the formation of human tooth dentin-pulp-enamel complexes in vitro. Scaffold characterization was demonstrated by SEM, FTIR and pore size and density measurements. The biological contraction of dental tissues against each other was demonstrated by mRNA gene expressions, histopatologic observations and protein release profile by ELISA tecnique. The tooth shaped constructs with a pore size ranging from 150 to 300 µm arranged by gathering right amounts of materials provide interconnected macro-porous structure. The newly formed tissue like structures that grow and integrate within the HA designed constructs forming tooth cementum like tissue, pulp and bone structures. These findings are important as they emphasize the potential biological effect of the hybrid scaffold system. In conclusion, this in vitro study clearly demonstrates that designed 3D scaffolds shaped as a immature tooth at the late bell stage were essential to form enamel-dentin-pulp interfaces with an appropriate cell and biodegradable material combination. The biomimetic architecture achieved here is providing a promising platform for dental tissue engineering.

Keywords: tooth regeneration, tissue engineering, adipose stem cells, hydroxyapatite tooth engineering, porous scaffold

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Authors: Narjis Kahtoon

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The issue of the wage discrimination on the basis of gender and social problem has been a significant research problem for several decades. Whereas lots of have explored reasons for the persistence of an inequality in the wages of male and female, none has successfully explained away the entire differentiation. The wage discrimination on the basis of gender and social problem of working women is a global issue. Although inequality in political and economic and social make-up of countries all over the world, the gender wage discrimination, and social constraint is present. The aim of the research is to examine the gender wage discrimination and social constraint from an international perspective and to determine whether any pattern exists among cultural dimensions of a country and the man and women remuneration gap in Readymade Garment Sector of Pakistan. Population growth rate is significant indicator used to explain the change in population and play a crucial point in the economic development of a country. In Pakistan, readymade garment sector consists of small, medium and large sized firms. With an estimated 30 percent of the workforce in textile- Garment is females’. Readymade garment industry is a labor intensive industry and relies on the skills of individual workers and provides highest value addition in the textile sector. In the Garment sector, female workers are concentrated in poorly paid, labor-intensive down-stream production (readymade garments, linen, towels, etc.), while male workers dominate capital- intensive (ginning, spinning and weaving) processes. Gender wage discrimination and social constraint are reality in Pakistan Labor Market. This research allows us not only to properly detect the size of gender wage discrimination and social constraint but to also fully understand its consequences in readymade garment sector of Pakistan. Furthermore, research will evaluated this measure for the three main clusters like Lahore, Karachi, and Faisalabad. These data contain complete details of male and female workers and supervisors in the readymade garment sector of Pakistan. These sources of information provide a unique opportunity to reanalyze the previous finding in the literature. The regression analysis focused on the standard 'Mincerian' earning equation and estimates it separately by gender, the research will also imply the cultural dimensions developed by Hofstede (2001) to profile a country’s cultural status and compare those cultural dimensions to the wage inequalities. Readymade garment of Pakistan is one of the important sectors since its products have huge demand at home and abroad. These researches will a major influence on the measures undertaken to design a public policy regarding wage discrimination and social constraint in readymade garment sector of Pakistan.

Keywords: gender wage differentials, decomposition, garment, cultural

Procedia PDF Downloads 190

Authors: S. Mezghani, E. Perrin, J. L. Bodnar, J. Marthe, B. Cauwe, V. Vrabie

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Non contact evaluation of the thickness of paint coatings can be attempted by different destructive and nondestructive methods such as cross-section microscopy, gravimetric mass measurement, magnetic gauges, Eddy current, ultrasound or terahertz. Infrared thermography is a nondestructive and non-invasive method that can be envisaged as a useful tool to measure the surface thickness variations by analyzing the temperature response. In this paper, the thermal quadrupole method for two layered samples heated up with a pulsed excitation is firstly used. By analyzing the thermal responses as a function of thermal properties and thicknesses of both layers, optimal parameters for the excitation source can be identified. Simulations show that a pulsed excitation with duration of ten milliseconds allows to obtain a substrate-independent thermal response. Based on this result, an experimental setup consisting of a near-infrared laser diode and an Infrared camera was next used to evaluate the variation of paint coating thickness between 60 µm and 130 µm on two samples. Results show that the parameters extracted for thermal images are correlated with the estimated thicknesses by the Eddy current methods. The laser pulsed thermography is thus an interesting alternative nondestructive method that can be moreover used for non conductive substrates.

Keywords: non destructive, paint coating, thickness, infrared thermography, laser, heterogeneity

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Authors: Erfan Asghari Fesaghandis, Reza Ghaffari Adli, Abbas Kianvash, Hossein Aghajani, Homa Homaie

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NiTi alloys possess magnificent superelastic, shape memory, high strength and biocompatible properties. For improving mechanical properties, foremost, superelasticity behavior, heat treatment process is carried out. In this paper, two different heat treatment methods were undertaken: (1) solid solution, and (2) aging. The effect of each treatment in a constant time is investigated. Five samples were prepared to study the structure and optimize mechanical properties under different time and temperature. For measuring the upper plateau stress, lower plateau stress and residual strain, tensile test is carried out. The samples were aged at two different temperatures to see difference between aging temperatures. The sample aged at 500 °C has a bigger crystallite size and lower amount of Ni which causes the mentioned sample to possess poor pseudo elasticity behaviour than the other aged sample. The sample aged at 460 °C has shown remarkable superelastic properties. The mentioned sample’s higher plateau is 580 MPa with the lowest residual strain (0.17%) while other samples have possessed higher residual strains. X-ray diffraction was used to investigate the produced phases.

Keywords: heat treatment, phase transformation, superelasticity, NiTi alloy

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Authors: El Miloudi Djelloul

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Based on analysis on applications by perception control technology in computer network security status and security protection measures, from the angles of network physical environment and network software system environmental security, this paper provides network security system perception control solution using Internet of Things (IOT), telecom and other perception technologies. Security Perception Control System is in the computer network environment, utilizing Radio Frequency Identification (RFID) of IOT and telecom integration technology to carry out integration design for systems. In the network physical security environment, RFID temperature, humidity, gas and perception technologies are used to do surveillance on environmental data, dynamic perception technology is used for network system security environment, user-defined security parameters, security log are used for quick data analysis, extends control on I/O interface, by development of API and AT command, Computer Network Security Perception Control based on Internet and GSM/GPRS is achieved, which enables users to carry out interactive perception and control for network security environment by WEB, E-MAIL as well as PDA, mobile phone short message and Internet. In the system testing, through middle ware server, security information data perception in real time with deviation of 3-5% was achieved; it proves the feasibility of Computer Network Security Perception Control System.

Keywords: computer network, perception control system security strategy, Radio Frequency Identification (RFID)

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Authors: Umran Kurtan, Hamide Aydin, Sevim Unugur Celik, Ayhan Bozkurt

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In the present work, novel hBN/polyacrylonitrile composite nanofibers were produced via electrospinning approach and loaded with the electrolyte for rechargeable lithium-ion battery applications. The electrospun nanofibers comprising various hBN contents were characterized by using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The influence of hBN/PAN ratios onto the properties of the porous composite system, such as fiber diameter, porosity, and the liquid electrolyte uptake capability were systematically studied. Ionic conductivities and electrochemical characterizations were evaluated after loading electrospun hBN/PAN composite nanofiber with liquid electrolyte, i.e., 1 M lithium hexafluorophosphate (LiPF6) in ethylene carbonate (EC)/ethyl methyl carbonate (EMC) (1:1 vol). The electrolyte loaded nanofiber has a highest ionic conductivity of 10−3 S cm⁻¹ at room temperature. According to cyclic voltammetry (CV) results it exhibited a high electrochemical stability window up to 4.7 V versus Li+/Li. Li//10 wt% hBN/PAN//LiCO₂ cell was produced which delivered high discharge capacity of 144 mAhg⁻¹ and capacity retention of 92.4%. Considering high safety and low cost properties of the resulting hBN/PAN fiber electrolytes, these materials can be suggested as potential separator materials for lithium-ion batteries.

Keywords: hexagonal boron nitride, polyacrylonitrile, electrospinning, lithium ion battery

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Authors: Wu Wei-Ting, Liu Po-Yen, Chang Chin-Tzu, Cheng Wei-Chun

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Three types of low-temperature phase transformations in an Fe-12.5 Mn-6.53 Al-1.28 C (wt %) alloy have been studied. The steel underwent solution heat treatment at 1100℃ and isothermal holding at low temperatures. γ’ phase appears in the austenite matrix in the air-cooled steel. Coherent ultra-fine particles of γ’ phase precipitated uniformly in the austenite matrix after the air-cooling process. These ultra-fine particles were very small and only could be detected by TEM through dark-field images. After short periods of isothermal holding at low temperatures these particles of γ’ phase grew and could be easily detected by TEM. A pro-eutectoid reaction happened after isothermal holding at temperatures below 875 ℃. Proeutectoid κ-carbide and ferrite appear in the austenite matrix as grain boundary precipitates and cellular precipitates. The cellular precipitates are composed of lamellar κ-carbide and austenite. The lamellar κ-carbide grains are always accompanied by layers of austenite twins. The presence of twin layers adhering to the κ-carbide plates might be attributed to the lower activation energy for the precipitation of κ-carbide plates in the austenite. The final form of phase transformation is the eutectoid reaction for the decomposition of supersaturated austenite into stable κ-carbide and ferrite phases at temperatures below 700℃. The ferrite and κ-carbide are in the form of pearlite lamellae.

Keywords: austenite, austenite twin layers, κ-carbide, twins

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Authors: Khobaib Khobaib, Alexander Mikkelsen, Zbigniew Rozynek

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Electric fields have proven useful for inducing droplet deformation and to structure particles adsorbed at droplet interfaces. In this experimental research, direct current electric fields were applied to deform particle-covered droplets made out of silicone oil and immersed in castor oil. The viscosity of the drop and surrounding fluid were changed by external heating. We designed an experimental system in such a way that electric field-induced electrohydrodynamic (EHD) flows were asymmetric and only present on one side of the drop, i.e., the droplet adjoined a washer and adhered to one of the electrodes constituting the sample cell. The study investigated the influence of viscosity on the steady-state deformation magnitude of particle-laden droplets, droplet compression, and relaxation, as well as particle arrangements at drop interfaces. Initially, before the application of an electric field, we changed the viscosity of the fluids by heating the sample cell at different temperatures. The viscosity of the fluids was varied by changing the temperature of the fluids from 25 to 50°C. Under the application of a uniform electric field of strength 290 Vmm⁻¹, electric stress was induced at the drop interface, yielding drop deformation. In our study, we found that by lowering the fluid viscosity, the velocity of the EHD flows was increased, which also increases the deformation of the drop.

Keywords: drop deformation and relaxation, electric field, electrohydrodynamic flow, particle assembly, viscosity

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Authors: Yogi Wibisono Budhi, Ferry Iskandar, Veinardi Suendo, Muhammad Fakhrudin, Neng Tresna Umi Culsum

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Oil palm empty fruit bunch (OPEFB), an abundant agro-waste in Indonesia, is being studied as raw material of Cellulose Nanocrystals (CNC) synthesis. Instead of conventional acid mineral, phosphotungstic acid (H₃PW₁₂O₄₀, HPW) was used to hydrolyze cellulose due to recycling ability and easy handling. Before hydrolysis process, dried EFB was treated by 4% NaOH solution at 90oC for 2 hours and then bleached using 2% NaClO₂ solution at 80oC for 3 hours to remove hemicellulose and lignin. Hydrolysis reaction parameters such as temperature, acid concentration, and reaction time were optimized with fixed solid-liquid ratio of 1:40. Response surface method was used for experimental design to determine the optimum condition of each parameter. HPW was extracted from the mixed solution and recycled with diethyl ether. CNC was separated from the solution by centrifuging and washing with distilled water and ethanol to remove degraded sugars and unreacted celluloses. In this study, pulp from dried EFB produced 44.8% yield of CNC. Dynamic Light Scattering (DLS) analysis showed that most of CNC equivalent diameter was 140 nm. Crystallinity index was observed at 73.3% using X-ray Diffraction (XRD) analysis. Thus, a green established process for the preparation of CNC was achieved.

Keywords: acid hydrolysis, cellulose nanocrystals, oil palm empty fruit bunch, phosphotungstic acid

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Authors: Kalpana Singh, Nikita Katiyar

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This research investigates the impact of Raga Bhairavi, a prominent musical scale in Indian classical music, on the mood and basic physiological parameters of research scholars at the University of Lucknow - India. The study focuses on the potential therapeutic effects of listening to Raga Bhairavi during morning hours. A controlled experimental design is employed, utilizing self-reporting tools for mood assessment and monitoring physiological indicators such as heart rate, oxygen saturation levels, body temperature and blood pressure. The hypothesis posits that exposure to Raga Bhairavi will lead to positive mood modulation and a reduction in physiological stress markers among research scholars. Data collection involves pre and post-exposure measurements, providing insights into the immediate and cumulative effects of the musical intervention. The study aims to contribute valuable information to the growing field of music therapy, offering a potential avenue for enhancing the well-being and productivity of individuals engaged in intense cognitive activities. Results may have implications for the integration of music-based interventions in academic and research environments, fostering a conducive atmosphere for intellectual pursuits.

Keywords: bio-musicology, classical music, mood assessment, music therapy, physiology, Raga Bhairavi

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Authors: Saroj Poudel, Joshua Mancini, Douglas Pike, Jennifer Timm, Alexei Tyryshkin, Vikas Nanda, Paul Falkowski

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On the early Earth, protein-metal complexes likely harvested energy from a reduced environment. These complexes would have been precursors to the metabolic enzymes of ancient organisms. Hydrogenase is an essential enzyme in most anaerobic organisms for the reduction and oxidation of hydrogen in the environment and is likely one of the earliest evolved enzymes. To attempt to reinvent a precursor to modern hydrogenase, we computationally designed a short thirteen amino acid peptide that binds the often-required catalytic transition metal Nickel in hydrogenase. This simple complex can achieve hundreds of hydrogen evolution cycles using light energy in a broad range of temperature and pH. Biophysical and structural investigations strongly indicate the peptide forms a di-nickel active site analogous to Acetyl-CoA synthase, an ancient protein central to carbon reduction in the Wood-Ljungdahl pathway and capable of hydrogen evolution. This work demonstrates that prior to the complex evolution of multidomain enzymes, early peptide-metal complexes could have catalyzed energy transfer from the environment on the early Earth and enabled the evolution of modern metabolism

Keywords: hydrogenase, prebiotic enzyme, metalloenzyme, computational design

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Authors: Zulfiye Ahan, Mustafa Dogu, Elcin Yilmaz

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The use of nonwoven textile materials in many application areas is rapidly increasing thanks to their versatile performance properties. The automotive industry is one of the largest sectors in the world, with a potential market of more than 2 billion euros for nonwoven textile materials applications. Lightweight materials having higher mechanical performance, better sound and heat insulation properties are of interest in many applications. Since the usage of nonwoven surfaces provides many of these advantages, the demand for this kind of material is gradually growing, especially in the automotive industry. Nonwoven materials used in lightweight vehicles can contain economical and high strength thermoplastics as well as durable components such as glass fiber. By bringing these composite materials into foam structure containing micro or nanopores, products with high absorption ability, light and mechanically stronger can be fabricated. In this respect, our goal is to produce thermoplastic composite nonwoven by using nonwoven glass fiber fabric reinforced polypropylene (PP). Azodicarbonamide (ADC) was selected as a foaming agent, and a thermal process was applied to obtain a porous structure. Various foaming temperature ranges and residence times were studied to examine the foaming behaviour of the thermoplastic composite nonwoven. Physicochemical and mechanical tests were applied in order to analyze the characteristics of composite foams.

Keywords: composite nonwoven, thermoplastic foams, foaming agent, foaming behavior

Procedia PDF Downloads 219

Authors: Mohammadreza Akbari, Leila Abdollahpour, Sara Akbari, Pooya Soleimani

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Transferring thermo at the field of solid materials for instance tube-shaped structures, causing dynamical vibration at them. Majority of thermal and fluid processes are done engineering science at solid materials, for example, thermo-transferred pipes, fluids, chemical and nuclear reactors, include thermal processes, so, they need to consider the moment solid-fundamental structural strength unto these thermal interactions. Fluid and thermo retentive materials in front of external force to it like thermodynamical force, hydrodynamical force and static force continuously according to a function of time vibrated, and this action causes relative displacement of the structural materials elements, as a result, the moment resistance analysis preservation materials in thermal processes, the most important parameters for design are discussed. Including structural substrate holder temperature and fluid of the administrative and industrial center, is a cylindrical tube that for vibration analysis of cylindrical cells with heat and fluid transfer requires the use of vibration differential equations governing the structure of a tubular and thermal differential equations as the vibrating motive force at double-glazed cylinders.

Keywords: heat transfer, elements in cylindrical coordinates, analytical solving the governing equations, structural vibration

Procedia PDF Downloads 324

Authors: Anders Schou Simonsen, Thomas Condra, Kim Sørensen

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Various processes are modelled using a discrete phase, where particles are seeded from a source. Such particles can represent liquid water droplets, which are affecting the continuous phase by exchanging thermal energy, momentum, species etc. Discrete phases are typically modelled using parcel, which represents a collection of particles, which share properties such as temperature, velocity etc. When coupling the phases, the exchange rates are integrated over the cell, in which the parcel is located. This can cause spikes and fluctuating exchange rates. This paper presents an alternative method of coupling a discrete and a continuous plug flow phase. This is done using triangular parcels, which span between nodes following the dynamics of single droplets. Thus, the triangular parcels are propagated using the corner nodes. At each time step, the exchange rates are spatially integrated over the surface of the triangular parcels, which yields a smooth continuous exchange rate to the continuous phase. The results shows that the method is more stable, converges slightly faster and yields smooth exchange rates compared with the steam tube approach. However, the computational requirements are about five times greater, so the applicability of the alternative method should be limited to processes, where the exchange rates are important. The overall balances of the exchanged properties did not change significantly using the new approach.

Keywords: CFD, coupling, discrete phase, parcel

Procedia PDF Downloads 245

Authors: Dike H. Ogbuagu, Etsede J. Oritsematosan

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This work investigated possible inductions of CaC₂, often misused by fruit vendors to stimulate artificial ripening, on mammalian sperm morphology and viability. Thirty isogenic strains of male albino mice, Mus musculus (age≈ 8weeks; weight= 32.5±2.0g) were acclimatized (ambient temperature 28.0±1.0°C) for 2 weeks and fed standard growers mash and water ad libutum. They were later exposed to graded toxicant concentrations (w/w) of 2.5000, 1.2500, 0.6250, and 0.3125% in 4 cages. A control cage was also established. After 5 weeks, 3 animals from each cage were sacrificed by cervical dislocation and the cauda epididymis excised. Sperm morphology and viability were determined by microscopic procedures. The ANOVA, means plots, Student’s t-test and variation plots were used to analyze data. The common abnormalities observed included Double Head, Pin Head, Knobbed Head, No Tail and With Hook. The higher toxicant concentrations induced significantly lower body weights [F(829.899) ˃ Fcrit(4.19)] and more abnormalities [F(26.52) ˃ Fcrit(4.00)] at P˂0.05. Sperm cells in the control setup were significantly more viable than those in the 0.625% (t=0.005) and 2.500% toxicant doses (t=0.018) at the 95% confidence limit. CaC₂ appeared to induced morphological abnormalities and reduced viability in sperm cells of M. musculus.

Keywords: artificial ripening, calcium carbide, fruit vendors, sperm morphology, sperm viability

Procedia PDF Downloads 204

Authors: Elsayed Elmiligy, Dzolkhifili Omar, Norhayu Asib

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Sitophilus oryzae is a primary destructive insect pest. A study on nanoemulsion formulation of C. hystrix peel oil and evaluation of its insecticidal effect on the adults of S. oryzae was held in toxicology laboratory at Faculty of Agriculture, Universiti Putra Malaysia (UPM). Three nanoemulsion formulations (F1, F2, and F3) were prepared using C. hystrix peel oil (a.i), Tween 80 (surfactant), AMD 810 (carrier) and deionized water. The selected formulations have undergone stability tests, surface tension, zeta potential and particle size measurements. The formulations were tested for their contact and fumigant activity against the adults of S. oryzae. LC₅₀ values were obtained from Probit regressions using the Polo-PC program. All the formulations showed stability under storage temperature and centrifugation. They were characterized as nanoemulsions as they remained in the range of nanoscale 200 nm. The formulations revealed lower surface tension in the range of 29.5 to 30.4 mN/m. They showed stable of zeta potential values. The formulations showed the highest toxicity against the adults of S. oryzae. The order of decreasing toxicity was F1 > F2 > F3 with LC₅₀ values of 52.1, 58.5, and 61.7 µl/l for contact toxicity, and 71, 75.5, and 76.7 µl/l air for fumigant bioassay after 72 hours. Formulation of C. hystrix peel oil in a nanoemulsion enhance its effectiveness and reduce the amount of applied essential oil.

Keywords: Citrus hystrix peel oil, Sitophilus oryzae, nanoemulsion, contact toxicity, Fumigant bioassay

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Authors: M. Aboudalle, Le Btth, M. Sari, F. Meftah

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In parallel with the appearance of new materials, brick masonry had and still has an essential part of the construction market today, with new technical challenges in designing bricks to meet additional requirements. Being used in structural applications, predicting the performance of clay brick masonry allows a significant cost reduction, in terms of practical experimentation. The behavior of masonry walls depends on the behavior of their elementary components, such as bricks, joints, and coatings. Therefore, it is necessary to consider it at different scales (from the scale of the intrinsic material to the real scale of the wall) and then to develop appropriate models, using numerical simulations. The work presented in this paper focuses on the mechanical characterization of the terracotta material at ambient temperature. As a result, the static Young’s modulus obtained from the flexural test shows different values in comparison with the compression test, as well as with the dynamic Young’s modulus obtained from the Impulse excitation of vibration test. Moreover, the Young's modulus varies according to the direction in which samples are extracted, where the values in the extrusion direction diverge from the ones in the orthogonal directions. Based on these results, hollow bricks can be considered as transversely isotropic bimodulus material.

Keywords: bimodulus material, hollow clay brick, ımpulse excitation of vibration, transversely isotropic material, young’s modulus

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Authors: Samuel Matylewicz, K. W. Goossen

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The deployment of white or cool (high albedo) roofing is a common energy savings recommendation for a variety of buildings all over the world. Here, the effect of a white roof on the energy savings of an ice rink facility in the northeastern US is determined by measuring the effect of solar irradiance on the consumption of the rink's ice refrigeration system. The consumption of the refrigeration system was logged over a year, along with multiple weather vectors, and a statistical model was applied. The experimental model indicates that the expected savings of replacing the existing grey roof with a white roof on the consumption of the refrigeration system is only 4.7 %. This overall result of the statistical model is confirmed with isolated instances of otherwise similar weather days, but cloudy vs. sunny, where there was no measurable difference in refrigeration consumption up to the noise in the local data, which was a few percent. This compares with a simple theoretical calculation that indicates 30% savings. The difference is attributed to a lack of convective cooling of the roof in the theoretical model. The best experimental model shows a relative effect of the weather vectors dry bulb temperature, solar irradiance, wind speed, and relative humidity on refrigeration consumption of 1, 0.026, 0.163, and -0.056, respectively. This result can have an impact on decisions to apply white roofing to refrigerated buildings in general.

Keywords: cool roofs, solar cooling load, refrigerated buildings, energy-efficient building envelopes

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Authors: Itissam Abuiziah

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This work presents a case study of water-hammer analysis and control for the Oum Azza pumping station project in the coastal area of Rabat to Casablanca from the dam Sidi Mohamed Ben Abdellah (SMBA). This is a typical pumping system with a long penstock and is currently at design and executions stages. Since there is no ideal location for construction of protection devices, the protection devices were provisionally designed to protect the whole conveying pipeline. The simulation results for the transient conditions caused by a sudden pumping stopping without including any protection devices, show that there is a negative beyond 1300m to the station 5725m near the arrival of the reservoir, therefore; there is a need for the protection devices to protect the conveying pipeline. To achieve the goal behind the transient flow analysis which is to protect the conveying pipeline system, four scenarios had been investigated in this case study with two types of protecting devices (pressure relief valve and desurging tank with automatic air control). The four scenarios are conceders as with pressure relief valve, with pressure relief valve and a desurging tank with automatic air control, with pressure relief valve and tow desurging tanks with automatic air control and with pressure relief valve and three desurging tanks with automatic air control. The simulation result for the first scenario shows that overpressure corresponding to an instant pumping stopping is reduced from 263m to 240m, and the minimum hydraulic grad line for the length approximately from station 1300m to station 5725m is still below the pipeline profile which means that the pipe must be equipped with another a protective devices for smoothing depressions. The simulation results for the second scenario show that the minimum and maximum pressures envelopes are decreases especially in the depression phase but not effectively protects the conduct in this case study. The minimum pressure increased from -77.7m for the previous scenario to -65.9m for the current scenario. Therefore the pipeline is still requiring additional protective devices; another desurging tank with automatic air control is installed at station2575.84m. The simulation results for the third scenario show that the minimum and maximum pressures envelopes are decreases but not effectively protects the conduct in this case study since the depression is still exist and varies from -0.6m to– 12m. Therefore the pipeline is still requiring additional protective devices; another desurging tank with automatic air control is installed at station 5670.32 m. Examination of the envelope curves of the minimum pressuresresults for the fourth scenario, we noticed that the piezometric pressure along the pipe remains positive over the entire length of the pipe. We can, therefore, conclude that such scenario can provide effective protection for the pipeline.

Keywords: analysis methods, protection devices, transient flow, water hammer

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Authors: H. Al-Baghli, F. Al-Asfour

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The current applied asphalt technology for Kuwait roads pavement infrastructure is the hot mix asphalt (HMA) pavement, including both pen grade and polymer modified bitumen (PMBs), that is produced and compacted at high temperature levels ranging from 150 to 180 °C. There are no current specifications for warm and cold mix asphalts in Kuwait’s Ministry of Public Works (MPW) asphalt standard and specifications. The process of the conventional HMA is energy intensive and directly responsible for the emission of greenhouse gases and other environmental hazards into the atmosphere leading to significant environmental impacts and raising health risk to labors at site. Warm mix asphalt (WMA) technology, a sustainable alternative preferred in multiple countries, has many environmental advantages because it requires lower production temperatures than HMA by 20 to 40 °C. The reduction of temperatures achieved by WMA originates from multiple technologies including foaming and chemical or organic additives that aim to reduce bitumen and improve mix workability. This paper presents a literature review of WMA technologies and techniques followed by an experimental study aiming to compare the results of produced WMA samples, using a water containing additive (foaming process), at different compaction temperatures with the HMA control volumetric properties mix designed in accordance to the new MPW’s specifications and guidelines.

Keywords: warm-mix asphalt, water-bearing additives, foaming-based process, chemical additives, organic additives

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Authors: Ikudayisi Akinola, Adeyemo Folasade, Adeyemo Josiah

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This study focuses on the hydro-geology and chemistry of Ikogosi Warm Spring in South West Nigeria. Ikogosi warm spring is a global tourist attraction because it has both warm and cold spring sources. Water samples from the cold spring, warm spring and the meeting point were collected, analyzed and the result shows close similarity in temperature, hydrogen iron concentration (pH), alkalinity, hardness, Calcium, Magnesium, Sodium, Iron, total dissolved solid and heavy metals. The measured parameters in the water samples are within World Health Organisation standards for fresh water. The study of the geology of the warm spring reveals that the study area is underlain by a group of slightly migmatised to non-migmatised paraschists and meta-igneous rocks. The concentration levels of selected heavy metals, (Copper, Cadmium, Zinc, Arsenic and Cromium) were determined in the water (ppm) samples. Chromium had the highest concentration value of 1.52ppm (an average of 49.67%) and Cadmium had the lowest concentration with value of 0.15ppm (an average of 4.89%). Comparison of these results showed that, their mean levels are within the standard values obtained in Nigeria. It can be concluded that both warm and spring water are safe for drinking.

Keywords: cold spring, Ikogosi, melting point, warm spring, water samples

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Authors: Rajneesh, Priyanka Singh

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Biomass resources have been one of the main energy sources for mankind since the dawn of civilization. There is a vast scope to convert these energy sources into biogas which is a clean, low carbon technology for efficient management and conversion of fermentable organic wastes into a cheap and versatile fuel and bio/organic manure. Thus, in order to enhance the performance of anaerobic digester, an optimizing analysis of resultant parameters (organic dry matter (oDM) content, methane percentage, and biogas yield) has been done for a plug flow anaerobic digester having mesophilic conditions (20-40°C) with the wet fermentation process. Based on the analysis, correlations for oDM, methane percentage, and biogas yield are derived using multiple regression analysis. A statistical model is developed to correlate the operating variables using the design of experiment approach by selecting central composite design (CCD) of a response surface methodology. Results shown in the paper indicates that as the operating temperature increases the efficiency of digester gets improved provided that the pH and hydraulic retention time (HRT) remains constant. Working in an optimized range of carbon-nitrogen ratio for the plug flow digester, the output parameters show a positive change with the variation of dry matter content (DM).

Keywords: biogas, digester efficiency, design of experiment, plug flow digester

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Authors: Abdelgawad, Salah El-Tahawy

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This paper aimed to establish econometrical equation models for the Nile delta region in Egypt, which will represent a basement for future predictions of Lumpy skin disease outbreaks and its pathway in relation to climate change. Data of lumpy skin disease (LSD) outbreaks were collected from the cattle farms located in the provinces representing the Nile delta region during 1 January, 2015 to December, 2015. The obtained results indicated that there was a significant association between the degree of the LSD outbreaks and the investigated climate factors (temperature, wind speed, and humidity) and the outbreaks peaked during the months of June, July, and August and gradually decreased to the lowest rate in January, February, and December. The model obtained depicted that the increment of these climate factors were associated with evidently increment on LSD outbreaks on the Nile Delta of Egypt. The model validation process was done by the root mean square error (RMSE) and means bias (MB) which compared the number of LSD outbreaks expected with the number of observed outbreaks and estimated the confidence level of the model. The value of RMSE was 1.38% and MB was 99.50% confirming that this established model described the current association between the LSD outbreaks and the change on climate factors and also can be used as a base for predicting the of LSD outbreaks depending on the climatic change on the future.

Keywords: LSD, climate factors, Nile delta, modeling

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Authors: Rastislav Stojsavljevic

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During most of the Middle Ages, warmer-than-average weather prevailed in the Balkan Peninsula in Southeast Europe. This period is also called Medieval Climate Optimum. It had its most noticeable phases during the 12th and 13th centuries. Due to climatic conditions, the appearance of unstable weather was observed. Strong storms and hail were a frequent occurrence. From the 9th to the 15th century, the Christian religion dominated the Balkan Peninsula. From East-West Schism (1054 A.D.), most of the people in Balkan states belonged to Eastern Orthodox churches: Byzantium, Bulgaria, Serbia and Bosnia. Medieval Croatia and the coastal part (the Adriatic Sea) of Zeta belonged to the Roman Catholic church. In addition to the dominant Christian religion, a lot of pagan Slavic cults remained in the Balkans during the Middle Ages. Various superstitions were a regular occurrence. They were dominant during severe storms, floods, great droughts, the appearance of comets, etc. In this paper, the appearance of warm and cold temperature spells will be investigated. In the second half of the 14th century, the Little Ice Age began and lasted for several centuries. The period of the first half of the 15th century is characterized by cold and snowy winters. Hunger was a regular occurrence. This has given rise to many beliefs which will be researched and mentioned in the paper.

Keywords: the Balkans, religion, medieval climate optimum, little ice age

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Authors: Beata Lachtara, Renata Szewczyk, Katarzyna Bielinska, Kinga Wieczorek, Jacek Osek

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Listeria monocytogenes is an important human and animal pathogen that causes foodborne outbreaks. The bacteria may be present in different types of food: cheese, raw vegetables, sliced meat products and vacuum-packed sausages, poultry, meat, fish. The most common method, which has been used for the investigation of genetic diversity of L. monocytogenes, is PFGE. This technique is reliable and reproducible and established as gold standard for typing of L. monocytogenes. The aim of the study was characterization by molecular serotyping and PFGE analysis of L. monocytogenes strains isolated from fresh fish and fish products in Poland. A total of 301 samples, including fresh fish (n = 129) and fish products (n = 172) were, collected between January 2014 and March 2016. The bacteria were detected using the ISO 11290-1 standard method. Molecular serotyping was performed with PCR. The isolates were tested with the PFGE method according to the protocol developed by the European Union Reference Laboratory for L. monocytogenes with some modifications. Based on the PFGE profiles, two dendrograms were generated for strains digested separately with two restriction enzymes: AscI and ApaI. Analysis of the fingerprint profiles was performed using Bionumerics software version 6.6 (Applied Maths, Belgium). The 95% of similarity was applied to differentiate the PFGE pulsotypes. The study revealed that 57 of 301 (18.9%) samples were positive for L. monocytogenes. The bacteria were identified in 29 (50.9%) ready-to-eat fish products and in 28 (49.1%) fresh fish. It was found that 40 (70.2%) strains were of serotype 1/2a, 14 (24.6%) 1/2b, two (4.3%) 4b and one (1.8%) 1/2c. Serotypes 1/2a, 1/2b, and 4b were presented with the same frequency in both categories of food, whereas serotype 1/2c was detected only in fresh fish. The PFGE analysis with AscI demonstrated 43 different pulsotypes; among them 33 (76.7%) were represented by only one strain. The remaining 10 profiles contained more than one isolate. Among them 8 pulsotypes comprised of two L. monocytogenes isolates, one profile of three isolates and one restriction type of 5 strains. In case of ApaI typing, the PFGE analysis showed 27 different pulsotypes including 17 (63.0%) types represented by only one strain. Ten (37.0%) clusters contained more than one strain among which four profiles covered two strains; three had three isolates, one with five strains, one with eight strains and one with ten isolates. It was observed that the isolates assigned to the same PFGE type were usually of the same serotype (1/2a or 1/2b). The majority of the clusters had strains of both sources (fresh fish and fish products) isolated at different time. Most of the strains grouped in one cluster of the AscI restriction was assigned to the same groups in ApaI investigation. In conclusion, PFGE used in the study showed a high genetic diversity among L. monocytogenes. The strains were grouped into varied clonal clusters, which may suggest different sources of contamination. The results demonstrated that 1/2a serotype was the most common among isolates from fresh fish and fish products in Poland.

Keywords: Listeria monocytogenes, molecular characteristic, PFGE, serotyping

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Authors: Huimin Liu, Li Xiang, Yue Liu, Jing Wang

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Background: As one of typical case for the developing countries who are stepping into the aging times globally, more and more older people in China might face the problem of which they could not maintain normal life due to the functional disability. While the government take efforts to build long-term care system and further carry out related policies for the core concept, there is still lack of strong evidence to evaluating the profile of disability states in the elderly population and its transition rate. It has been proved that disability is a dynamic condition of the person rather than irreversible so it means possible to intervene timely on them who might be in a risk of severe disability. Objective: The aim of this study was to depict the picture of the disability transferring status of the older people in China, and then find out individual characteristics that change the state of disability to provide theory basis for disability prevention and early intervention among elderly people. Methods: Data for this study came from the 2011 baseline survey and the 2013 follow-up survey of the China Health and Retirement Longitudinal Study (CHARLS). Normal ADL function, 1~2 ADLs disability,3 or above ADLs disability and death were defined from state 1 to state 4. Multi-state Markov model was applied and the four-state homogeneous model with discrete states and discrete times from two visits follow-up data was constructed to explore factors for various progressive stages. We modeled the effect of explanatory variables on the rates of transition by using a proportional intensities model with covariate, such as gender. Result: In the total sample, state 2 constituent ratio is nearly about 17.0%, while state 3 proportion is blow the former, accounting for 8.5%. Moreover, ADL disability statistics difference is not obvious between two years. About half of the state 2 in 2011 improved to become normal in 2013 even though they get elder. However, state 3 transferred into the proportion of death increased obviously, closed to the proportion back to state 2 or normal functions. From the estimated intensities, we see the older people are eleven times as likely to develop at 1~2 ADLs disability than dying. After disability onset (state 2), progression to state 3 is 30% more likely than recovery. Once in state 3, a mean of 0.76 years is spent before death or recovery. In this model, a typical person in state 2 has a probability of 0.5 of disability-free one year from now while the moderate disabled or above has a probability of 0.14 being dead. Conclusion: On the long-term care cost considerations, preventive programs for delay the disability progression of the elderly could be adopted based on the current disabled state and main factors of each stage. And in general terms, those focusing elderly individuals who are moderate or above disabled should go first.

Keywords: Markov model, elderly people, disability, transition intensity

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Authors: M. Moncef Khaddar

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This paper focuses mainly on a contextualized understanding of ‘autocratic authoritarianism’ in Tunisia without approaching its peculiarities in reference to the ideal type of capitalist-liberal democracy but rather analysing it as a Tunisian ‘civilian dictatorship’. This is reminiscent, to some extent, of the French ‘colonial authoritarianism’ in parallel with the legacy of the traditional formal monarchic absolutism. The Tunisian autocratic political system is here construed as a state manufactured nationalist-populist authoritarianism associated with a de facto presidential single party, two successive autocratic presidents and their subservient autocratic elites who ruled with an iron fist the de-colonialized ‘liberated nation’ that came to be subjected to a large scale oppression and domination under the new Tunisian Republic. The diachronic survey of Tunisia’s autocratic authoritarian system covers the early years of autocracy, under the first autocratic president Bourguiba, 1957-1987, as well as the different stages of its consolidation into a police-security state under the second autocratic president, Ben Ali, 1987-2011. Comparing the policies of authoritarian regimes, within what is identified synchronically as a bi-cephalous autocratic system, entails an in-depth study of the two autocrats, who ruled Tunisia for more than half a century, as modern adaptable autocrats. This is further supported by an exploration of the ruling authoritarian autocratic elites who played a decisive role in shaping the undemocratic state-society relations, under the 1st and 2nd President, and left an indelible mark, structurally and ideologically, on Tunisian polity. Emphasis is also put on the members of the governmental and state-party institutions and apparatuses that kept circulating and recycling from one authoritarian regime to another, and from the first ‘founding’ autocrat to his putschist successor who consolidated authoritarian stability, political continuity and autocratic governance. The reconfiguration of Tunisian political life, in the post-autocratic era, since 2011 will be analysed. This will be scrutinized, especially in light of the unexpected return of many high-profile figures and old guards of the autocratic authoritarian apparatchiks. How and why were, these public figures, from an autocratic era, able to return in a supposedly post-revolutionary moment? Finally, while some continue to celebrate the putative exceptional success of ‘democratic transition’ in Tunisia, within a context of ‘unfinished revolution’, others remain perplexed in the face of a creeping ‘oligarchic transition’ to a ‘hybrid regime’, characterized rather by elites’ reformist tradition than a bottom-up genuine democratic ‘change’. This latter is far from answering the 2010 ordinary people’s ‘uprisings’ and ‘aspirations, for ‘Dignity, Liberty and Social Justice’.

Keywords: authoritarianism, autocracy, democratization, democracy, populism, transition, Tunisia

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Authors: Ikram Kamal, Mohamed Blaghen

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Biosurfactants are amphiphilic biological compounds consisting of hydrophobic and hydrophilic domains produced extracellularly or as part of the cell membrane by a variety of yeast, bacteria and filamentous fungi. Biosurfactant applications in the environmental industries are promising due to their biodegradability, low toxicity, and effectiveness in enhancing biodegradation and solubilization of low solubility compounds. Currently, the main application is for enhancement of oil recovery and hydrocarbon bioremediation due to their biodegradability and low critical micelle concentration (CMC). The use of biosurfactants has also been proposed for various industrial applications, such as in food additives, cosmetics, detergent formulations and in combinations with enzymes for wastewater treatment. In this study, we have investigated the potential of bacterial strains: Mannheimia haemolytica, Burkholderia cepacia and Serratia ficaria were collected aseptically from the lagoon Marchika (water and soil) in Nador, Morocco; for the production of biosurfactants. This study also aimed to optimize the biosurfactant production process by changing the variables that influence the type and amount of biosurfactant produced by these microorganisms such as: carbon sources and also other physical and chemical parameters such as temperature and pH. Emulsification index, methylene blue test, and thin layer chromatography (TLC) revealed the ability of strains used in this study to produce compounds that could emulsify gasoline. In addition, a GC/MS was used to separate and identify different biosurfactants purified.

Keywords: biosurfactants, Mannheimia haemolytica, biodegradability, Burkholderia cepacia, Serratia ficaria

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Authors: Izabella Szollosi, Klara Marton

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Aphasia can be defined as a weakness in accessing linguistic information. Accessing linguistic information is strongly related to information processing, which in turn is associated with the cognitive control system. According to the literature, a deficit in the cognitive control system interferes with language processing and contributes to non-fluent speech performance. The aim of our study was to explore this hypothesis by investigating how cognitive control interacts with language performance in participants with non-fluent aphasia. Cognitive control is a complex construct that includes working memory (WM) and the ability to resist proactive interference (PI). Based on previous research, we hypothesized that impairments in domain-general (DG) cognitive control abilities have negative effects on language processing. In contrast, better DG cognitive control functioning supports goal-directed behavior in language-related processes as well. Since stroke itself might slow down information processing, it is important to examine its negative effects on both cognitive control and language processing. Participants (N=52) in our study were individuals with non-fluent Broca’s aphasia (N = 13), with transcortical motor aphasia (N=13), individuals with stroke damage without aphasia (N=13), and unimpaired speakers (N = 13). All participants performed various computer-based tasks targeting cognitive control functions such as WM and resistance to PI in both linguistic and non-linguistic domains. Non-linguistic tasks targeted primarily DG functions, while linguistic tasks targeted more domain specific (DS) processes. The results showed that participants with Broca’s aphasia differed from the other three groups in the non-linguistic tasks. They performed significantly worse even in the baseline conditions. In contrast, we found a different performance profile in the linguistic domain, where the control group differed from all three stroke-related groups. The three groups with impairment performed more poorly than the controls but similar to each other in the verbal baseline condition. In the more complex verbal PI condition, however, participants with Broca’s aphasia performed significantly worse than all the other groups. Participants with Broca’s aphasia demonstrated the most severe language impairment and the highest vulnerability in tasks measuring DG cognitive control functions. Results support the notion that the more severe the cognitive control impairment, the more severe the aphasia. Thus, our findings suggest a strong interaction between cognitive control and language. Individuals with the most severe and most general cognitive control deficit - participants with Broca’s aphasia - showed the most severe language impairment. Individuals with better DG cognitive control functions demonstrated better language performance. While all participants with stroke damage showed impaired cognitive control functions in the linguistic domain, participants with better language skills performed also better in tasks that measured non-linguistic cognitive control functions. The overall results indicate that the level of cognitive control deficit interacts with the language functions in individuals along with the language spectrum (from severe to no impairment). However, future research is needed to determine any directionality.

Keywords: cognitive control, information processing, language performance, non-fluent aphasia

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Authors: Joseph C. Chen, Joshua Cox

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This research focuses on the use of the Taguchi method to reduce the surface roughness and improve dimensional accuracy of parts machined by Wire Electrical Discharge Machining (EDM) with S7 heat treated steel material. Due to its high impact toughness, the material is a candidate for a wide variety of tooling applications which require high precision in dimension and desired surface roughness. This paper demonstrates that Taguchi Parameter Design methodology is able to optimize both dimensioning and surface roughness successfully by investigating seven wire-EDM controllable parameters: pulse on time (ON), pulse off time (OFF), servo voltage (SV), voltage (V), servo feed (SF), wire tension (WT), and wire speed (WS). The temperature of the water in the Wire EDM process is investigated as the noise factor in this research. Experimental design and analysis based on L₁₈ Taguchi orthogonal arrays are conducted. This paper demonstrates that the Taguchi-based system enables the wire EDM process to produce (1) high precision parts with an average of 0.6601 inches dimension, while the desired dimension is 0.6600 inches; and (2) surface roughness of 1.7322 microns which is significantly improved from 2.8160 microns.

Keywords: Taguchi Parameter Design, surface roughness, Wire EDM, dimensional accuracy

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