Search results for: D. Planes Meseguer

Authors: Doo W. Lee, Soo J. Lee, Bye R. Yoon, Jae Y. Jho, Kyehan Rhee

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Hand exoskeletons have been developed in order to assist daily activities for disabled and elder people. A figure exoskeleton was developed using ionic polymer metal composite (IPMC) actuators, and the performance of it was evaluated in this study. In order to study dynamic performance of a finger dummy performing pinching motion, force generating characteristics of an IPMC actuator and pinching motion of a thumb and index finger dummy actuated by IMPC actuators were analyzed. The blocking force of 1.54 N was achieved under 4 V of DC. A thumb and index finger dummy, which has one degree of freedom at the proximal joint of each figure, was manufactured by a three dimensional rapid prototyping. Each figure was actuated by an IPMC actuator, and the maximum fingertip force was 1.18 N. Pinching motion of a dummy was analyzed by two video cameras in vertical top and horizontal left end view planes. A figure dummy powered by IPMC actuators could perform flexion and extension motion of an index figure and a thumb.

Keywords: finger exoskeleton, ionic polymer metal composite, flexion and extension, motion analysis

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Authors: M. Okeke, A. Blyth

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Industrial Control Systems (ICS) such as Supervisory Control And Data Acquisition (SCADA) can be seen in many different critical infrastructures, from nuclear management to utility, medical equipment, power, waste and engine management on ships and planes. The role SCADA plays in critical infrastructure has resulted in a call to secure them. Many lives depend on it for daily activities and the attack vectors are becoming more sophisticated. Hence, the security of ICS is vital as malfunction of it might result in huge risk. This paper describes how the application of Prey Predator (PP) approach in flocks of birds could enhance the detection of malicious activities on ICS. The PP approach explains how these animals in groups or flocks detect predators by following some simple rules. They are not necessarily very intelligent animals but their approach in solving complex issues such as detection through corporation, coordination and communication worth emulating. This paper will emulate flocking behavior seen in birds in detecting predators. The PP approach will adopt six nearest bird approach in detecting any predator. Their local and global bests are based on the individual detection as well as group detection. The PP algorithm was designed following MapReduce methodology that follows a Split Detection Convergence (SDC) approach.

Keywords: artificial life, industrial control system (ICS), IDS, prey predator (PP), SCADA, SDC

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Authors: Demet Tatar, Bahattin Düzgün

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In this study, we have newly developed titanium-tin oxide (TiSnO) thin films as the transparent conducting oxides materials by the spray pyrolysis technique. Tin oxide thin films doped with different Ti content were successfully grown by spray pyrolysis and they were characterized as a function of Ti content. The effect of Ti contents on the crystalline structure and optical properties of the as-deposited SnO2:Ti films was systematically investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), atomic force microscopy (AFM), UV-vis spectrometer and photoluminecenc spectrophotometer. The X-ray diffraction patterns taken at room temperature showed that the films are polycrystalline. The preferred directions of crystal growth appeared in the difractogram of SnO2: Ti (TiTO) films were correspond to the reflections from the (110), (200), (211) and (301) planes. The grain size varies from 21.8 to 27.8 nm for (110) preferred plane. SEM and AFM study reveals the surface of TiTO to be made of nanocrystalline particles. The highest visible transmittance (570 nm) of the deposited films is 80 % for 20 wt % titanium doped tin oxide films. The obtained results revealed that the structures and optical properties of the films were greatly affected by doping levels. These films are useful as conducting layers in electro chromic and photovoltaic devices.

Keywords: transparent conducting oxide, gas sensors, SnO2, Ti, optoelectronic, spray pyrolysis

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Authors: Zoran Jovanovic, Zoran Masonicic, S. Dragutinovic, Z. Sakota

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In this paper, results concerning flame propagation of various fuels in a particular combustion chamber with four tilted valves were elucidated. Flame propagation was represented by the evolution of spatial distribution of temperature in various cut-planes within combustion chamber while the flame front location was determined by dint of zones with maximum temperature gradient. The results presented are only a small part of broader on-going scrutinizing activity in the field of multidimensional modeling of reactive flows in combustion chambers with complicated geometries encompassing various models of turbulence, different fuels and combustion models. In the case of turbulence two different models were applied i.e. standard k-ε model of turbulence and k-ξ-f model of turbulence. In this paper flame propagation results were analyzed and presented for two different hydrocarbon fuels, such as CH4 and C8H18. In the case of combustion all differences ensuing from different turbulence models, obvious for non-reactive flows are annihilated entirely. Namely the interplay between fluid flow pattern and flame propagation is invariant as regards turbulence models and fuels applied. Namely the interplay between fluid flow pattern and flame propagation is entirely invariant as regards fuel variation indicating that the flame propagation through unburned mixture of CH4 and C8H18 fuels is not chemically controlled.

Keywords: automotive flows, flame propagation, combustion modelling, CNG

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Authors: M.F. Elkady, Sahar Zaki, Desouky Abd-El-Haleem

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Silver nanoparticles (AgNPs) are already widely prepared using different technologies. However, there are limited data on the effects of hydrogen ion concentration on nano-silver production. In this investigation, the impact of the pH reaction medium toward the particle size, agglomeration and the yield of the produced bio-synthesized silver were established. Quasi-spherical silver nanoparticles were synthesized through the biosynthesis green production process using the Egyptian E. coli bacterial strain 23N at different pH values. The formation of AgNPs has been confirmed with ultraviolet–visible spectra through identification of their characteristic peak at 410 nm. The quantitative production yield and the orientation planes of the produced nano-silver were examined using X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Quantitative analyses indicated that the silver production yield was promoted at elevated pH regarded to increase the reduction rate of silver precursor through both chemical and biological processes. As a result, number of the nucleus and thus the size of the silver nanoparticles were tunable through changing pH of the reaction system. Accordingly, the morphological structure and size of the produced silver and its aggregates were determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. It was considered that the increment in pH value of the reaction media progress the aggregation of silver clusters. However, the presence of stain 23N biomass decreases the possibility of silver aggregation at the pH 7.

Keywords: silver nanoparticles, biosynthesis, reaction media pH, nano-silver characterization

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Authors: Xianjia Meng, Chuanyong Qu

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Compact bone produces fatigue damage under the inevitable physiological load. The accumulation of fatigue damage can change the bone’s micro-structure at different scales and cause the catastrophic failure eventually. However, most tests were limited to the macroscopic modulus of bone and there is a need to assess the microscopic modulus during fatigue progress. In this paper, nano-identation was used to investigate the bone specimen subjected to four point bending. The microscopic modulus of the same area were measured at different degrees of damage including fracture. So microscopic damage can be divided into three stages: first, the modulus decreased rapidly and then They fell slowly, before fracture the decline became fast again. After fracture, the average modulus decreased by 20%. The results of inner and outer planes explained the influence of compressive and tensile loads on modulus. Both the compressive and tensile moduli decreased with the accumulation of damage. They reached the minimum at ending and increased after fracture. The modulus evolution under different strains were revealed by the side. They all fell slowly and then fast with the accumulation of damage. The fractured results indicated that the elastic modulus decreased obviously at the high strain while decreased less at the low strain. During the fatigue progress, there was a significant difference in modulus at low degree of damage. However, the dispersed modulus tended to be similar at high degree of damage, but they became different again after the failure.

Keywords: fatigue damage, fracture, microscopic modulus, bone, nano-identation

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Authors: Atilla Bayram

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This paper presents the trajectory tracking control of a spatial redundant hybrid manipulator. This manipulator consists of two parallel manipulators which are a variable geometry truss (VGT) module. In fact, each VGT module with 3-degress of freedom (DOF) is a planar parallel manipulator and their operational planes of these VGT modules are arranged to be orthogonal to each other. Also, the manipulator contains a twist motion part attached to the top of the second VGT module to supply the missing orientation of the endeffector. These three modules constitute totally 7-DOF hybrid (parallel-parallel) redundant spatial manipulator. The forward kinematics equations of this manipulator are obtained, then, according to these equations, the inverse kinematics is solved based on an optimization with the joint limit avoidance. The dynamic equations are formed by using virtual work method. In order to test the performance of the redundant manipulator and the controllers presented, two different desired trajectories are followed by using the computed force control method and a switching control method. The switching control method is combined with the computed force control method and genetic algorithm. In the switching control method, the genetic algorithm is only used for fine tuning in the compensation of the trajectory tracking errors.

Keywords: computed force method, genetic algorithm, hybrid manipulator, inverse kinematics of redundant manipulators, variable geometry truss

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Authors: Guanlin Wu, Jiajia Yao, Fang Liu, Junshuai Xue, Jincheng Zhang, Yue Hao

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Owing to the excellent thermal conductivity and ultra-wide bandgap, Aluminum nitride (AlN)/Gallium nitride (GaN) is a highly promising material to achieve high breakdown voltage and output power devices among III-nitrides. In this study, we explore the growth and characterization of polarization-induced AlN/GaN heterostructures using plasma-assisted molecular beam epitaxy (PA-MBE) on AlN-on-sapphire templates. To improve the crystal quality and demonstrate the effectiveness of the PA-MBE approach, a thick AlN buffer of 180 nm was first grown on the AlN-on sapphire template. This buffer acts as a back-barrier to enhance the breakdown characteristic and isolate leakage paths that exist in the interface between the AlN epilayer and the AlN template. A root-mean-square roughness of 0.2 nm over a scanned area of 2×2 µm2 was measured by atomic force microscopy (AFM), and the full-width at half-maximum of (002) and (102) planes on the X-ray rocking curve was 101 and 206 arcsec, respectively, using by high-resolution X-ray diffraction (HR-XRD). The electron mobility of 443 cm2/Vs with a carrier concentration of 2.50×1013 cm-2 at room temperature was achieved in the AlN/GaN heterostructures by using a polarization-induced GaN channel. The low depletion capacitance of 15 pF is resolved by the capacitance-voltage. These results indicate that the polarization-induced AlN/GaN heterostructures have great potential for next-generation high-temperature, high-frequency, and high-power electronics.

Keywords: AlN, GaN, MBE, heterostructures

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Authors: Mehmet Salih Bayraktutan

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Geomechanical properties of Rock Salt Deposits in Tuzluca Salt Mine Area (Eastern Turkey) are studied for modeling the operation- excavation strategy. The purpose of this research focused on calculating the critical value of span height- which will meet the safety requirements. The Mine Site Tuzluca Hills consist of alternating parallel bedding of Salt ( NaCl ) and Gypsum ( CaS04 + 2 H20) rocks. Rock Salt beds are more resistant than narrow Gypsum interlayers. Rock Salt beds formed almost 97 percent of the total height of the Hill. Therefore, the geotechnical safety of Galleries depends on the mechanical criteria of Rock Salt Cores. General deposition of Tuzluca Basin was finally completed by Tuzluca Evaporites, as for the uppermost stratigraphic unit. They are currently running mining operations performed by classic mechanical excavation, room and pillar method. Rooms and Pillars are currently experiencing an initial stage of fracturing in places. Geotechnical safety of the whole mining area evaluated by Rock Mass Rating (RMR), Rock Quality Designation (RQD) spacing of joints, and the interaction of groundwater and fracture system. In general, bedded rock salt Show large lateral deformation capacity (while deformation modulus stays in relative small values, here E= 9.86 GPa). In such litho-stratigraphic environments, creep is a critical mechanism in failure. Rock Salt creep rate in steady-state is greater than interbedding layers. Under long-lasted compressive stresses, creep may cause shear displacements, partly using bedding planes. Eventually, steady-state creep in time returns to accelerated stages. Uniaxial compression creep tests on specimens were performed to have an idea of rock salt strength. To give an idea, on Rock Salt cores, average axial strength and strain are found as 18 - 24 MPa and 0.43-0.45 %, respectively. Uniaxial Compressive strength of 26- 32 MPa, from bedded rock salt cores. Elastic modulus is comparatively low, but lateral deformation of the rock salt is high under the uniaxial compression stress state. Poisson ratio = 0.44, break load = 156 kN, cohesion c= 12.8 kg/cm2, specific gravity SG=2.17 gr/cm3. Fracture System; spacing of fractures, joints, faults, offsets are evaluated under acting geodynamic mechanism. Two sand beds, each 4-6 m thick, exist near to upper level and at the top of the evaporating sequence. They act as aquifers and keep infiltrated water on top for a long duration, which may result in the failure of roofs or pillars. Two major active seismic ( N30W and N70E ) striking Fault Planes and parallel fracture strands have seismically triggered moderate risk of structural deformation of rock salt bedding sequence. Earthquakes and Floods are two prevailing sources of geohazards in this region—the seismotectonic activity of the Mine Site based on the crossing framework of Kagizman Faults and Igdir Faults. Dominant Hazard Risk sources include; a) Weak mechanical properties of rock salt, gypsum, anhydrite beds-creep. b) Physical discontinuities cutting across the thick parallel layers of Evaporite Mass, c) Intercalated beds of weak cemented or loose sand, clayey sandy sediments. On the other hand, absorbing the effects of salt-gyps parallel bedded deposits on seismic wave amplitudes has a reducing effect on the Rock Mass.

Keywords: bedded rock salt, creep, failure mechanism, geotechnical safety

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Authors: Marwa Al-Subhi, Eiman Al-Ajmi, Mallak Al-Maamari, Humood Al-Dhuhli, Srinivasa Rao

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The orbit and its contents are affected by various pathologies and craniofacial anomalies. Sound knowledge of the normal orbital dimensions is clinically essential for successful surgical outcomes and also in the field of forensic anthropology. Racial, ethnic, and regional variations in the orbital dimensions have been reported. This study sought to determine the orbital dimensions of Omani subjects who had been referred for computed tomography (CT) images at a tertiary care hospital. A total of 273 patients’ CT images were evaluated retrospectively by using an electronic medical records database. The orbital dimensions were recorded using both axial and sagittal planes of CT images. The mean orbital index (OI) was found to be 83.25±4.83 and the prevalent orbital type was categorized as mesoseme. The mean orbital index was 83.34±5.05 and 83.16±4.57 in males and females, respectively, with their difference being statistically not significant (p=0.76). A statistically significant association was observed between the right and left orbits with regard to horizontal distance (p<0.05) and vertical distance (p<0.01) of orbit and OI (p<0.05). No significant difference between the OI and age groups was observed in both males and females. The mean interorbital distance and interzygomatic distance were found to be 19.45±1.52 mm and 95.59±4.08 mm, respectively. Both of these parameters were significantly higher in males (p<0.05). Results of the present study provide reference values of orbital dimensions in Omani subjects. The prevalent orbital type of Omani subjects is mesoseme, which is a hallmark of the white race.

Keywords: orbit, orbital index, mesoseme, ethnicity, variation

Procedia PDF Downloads 122

Authors: Reham H. Diab, Amira A. A. Abdallah, Eman A. Embaby

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Background: The effectiveness of bracing on preventing spino-pelvic alignment deterioration in idiopathic scoliosis has been extensively studied especially in the frontal plane. Yet, there is lack of knowledge regarding the effect of soft braces on spino-pelvic alignment in the sagittal plane. Achieving harmonious sagittal plane spino-pelvic balance is critical for the preservation of physiologic posture and spinal health. Purpose: This study examined the kyphotic angle, lordotic angle and pelvic inclination in the sagittal plane and trunk imbalance in the frontal plane before and after a six-month rehabilitation period. Methods: Nineteen patients with idiopathic scoliosis participated in the study. They were divided into two groups; experimental and control. The experimental group (group I) used the SpineCor brace in addition to a rehabilitation exercise program while the control group (group II) had the exercise program only. The mean ±SD age, weight and height were 16.89±2.15 vs. 15.3±2.5 years; 59.78±6.85 vs. 62.5±8.33 Kg and 162.78±5.76 vs. 159±5.72 cm for group I vs. group II. Data were collected using for metric Π system. Results: Mixed design MANOVA showed that there were significant (p < 0.05) decreases in all the tested variables after the six-month period compared with “before” in both groups. Moreover, there was a significant decrease in the kyphotic angle in group I compared with group II after the six-month period. Interpretation and conclusion: SpineCor brace is beneficial in reducing spino-pelvic alignment deterioration in both sagittal and frontal planes.

Keywords: adolescent idiopathic scoliosis, SpineCor, spino-pelvic alignment, biomechanics

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Authors: Mohammad Salem Abdullah Al-Hwaiti

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The stratiform copper mineralization of the Burj-Dolomite shale (BDS) formations of deposits shows that the copper mineralization within the BDS occurs as hydrated copper chlorides and carbonates (mainly paratacamite and malachite, respectively), while copper silicates (mainly chrysocolla and planchette) are the major ore minerals in the BDS. Thus, on the basis of the petrographic and field occurrence, three main stages operated during the development of the copper ore in the sandy and shaly lithofacies. During the first stage, amorphous chrysocolla replaced clays, feldspars, and quartz. This stage was followed by the transition from an amorphous phase to a better-crystallized phase, i.e., the formation of planchette and veins from chrysocolla. The third stage was the formation of chrysocolla along fracture planes. Other secondary minerals are pseudomalachite, dioptase, neoticite together with authigenic fluorapatite. Paratacamite and malachite, which are common in the dolomitic lithofacies, are relatively rare in the sandy and silty lithofacies. The Rare Earth Elements (REEs) patterns for the BDS showed three stages in the evolution of the Precambrian–Cambrian copper mineralization system, involving the following: (A) Epigenetic mobilization of Cu-bearing solution with formation Cu-carbonate in dolomite and limestone mineralization and Cu-silicate mineralization in sandstone; (B) Transgression of Cambrian Sea and SSC deposition of Cu-sulphides during dolomite diagenesis in the BDS Formation; continued diagenesis and oxidation leads to the formation of Cu(II) minerals; (C) Erosion and supergene enrichment of Cu in basement rocks. Detrital copper-bearing sediments accumulate in the lower Cambrian clastic sequence.

Keywords: dolomite shale, copper mineralization, REE, Jordan

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Authors: Abraham J. Rizkalla, Joanne F. Irons, Christopher Q. Cao

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Purpose: Lobectomy was considered the standard of care for early-stage non-small lung cancer (NSCLC) after the Lung Cancer Study Group trial demonstrated increased locoregional recurrence for sublobar resections. However, there has been heightened interest in segmentectomies for selected patients with peripheral lesions ≤2cm, as investigated by the JCOG0802 and CALGB140503 trials. Minimally invasive robotic surgery facilitates segmentectomies with improved maneuverability and visualization of intersegmental planes using indocyanine green. We hereby present a patient who underwent robotic lingulectomy for an undiagnosed ground-glass opacity. Methodology: This video demonstrates a robotic portal lingulectomy using three 8mm ports and a 12mm port. Stereoscopic direct vision facilitated the identification of the lingula artery and vein, and intra-operative bronchoscopy was performed to confirm the lingula bronchus. The intersegmental plane was identified by indocyanine green and a near-infrared camera. Thorough lymph node sampling was performed in accordance with international standards. Results: The 18mm lesion was successfully excised with clear margins to achieve R0 resection with no evidence of malignancy in the 8 lymph nodes sampled. Histopathological examination revealed lepidic predominant adenocarcinoma, pathological stage IA. Conclusion: This video presentation exemplifies the standard approach for robotic portal lingulectomy in appropriately selected patients.

Keywords: lung cancer, robotic segmentectomy, indocyanine green, lingulectomy

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Authors: Juan Antonio Mondragon Sanchez, Ruben Santamaria

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The DNA G-quadruplex is a four-stranded DNA structure conformed by stacked planes of four base paired guanines (G-quartet). The guanine rich DNA sequences are present in many sites of genomic DNA and can potentially lead to the formation of G-quadruplexes, especially at the 3'-terminus of the human telomeric DNA with many TTAGGG repeats. The formation and stabilization of a G-quadruplex by small ligands at the telomeric region can inhibit the telomerase activity. In turn, the ligands can be used to regulate oncogene expression making the G-quadruplex an attractive target for anticancer therapy. Clearly, the G-quadruplex structured in the telomeric DNA is of fundamental importance for rational drug design. In this context, we investigate two G-quadruplex structures, the first follows from the sequence TTAGGG(TTAGGG)3TT (HUT1), and the second from AAAGGG(TTAGGG)3AA (HUT2), both in a K+ solution. We determine the free energy surfaces of the HUT1 and HUT2 structures and investigate their conformations using replica-exchange metadynamics simulations. The carbonyl-carbonyl distances belonging to different guanines residues are selected as the main collective variables to determine the free energy surfaces. The surfaces exhibit two main local minima, compatible with experiments on the conformational transformations of HUT1 and HUT2 under substitution of the K+ ions by the Na+ ions. The conformational transitions are not observed in short MD simulations without the use of the metadynamics approach. The results of this work should be of help to understand the formation and stability of human telomeric G-quadruplex in environments including the presence of K+ and Na+ ions.

Keywords: g-quadruplex, metadynamics, molecular dynamics, replica-exchange

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Authors: Omid Khaiyat, David Hawkes

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Introduction: There remains a lack of information on sophisticated coordination patterns across shoulder girdle muscles. Considering the stability of the shoulder being heavily dependent on coordinated muscle activity during its wide-ranging movements, it is important that key intermuscular relationships are well-defined for a better understanding of underlying pathology. This study investigated shoulder intermuscular coordination during different planes of shoulder elevation. Materials and Methods: EMG was recorded from 14 shoulder muscles in 20 healthy participants during shoulder flexion, scapula plane elevation, abduction, and extension. Cross-correlation by means of Pearson Correlation Coefficient (PCC) was used to examine the coordination between different muscles and muscle groups. Results: Coordination between rotator cuff and deltoid muscle groups was significantly higher (p =0.020-0.035) during the initial (PCC) = 0.79) and final (PCC = 0.74) phases of elevation compared to the mid-range (PCC = 0.34). Furthermore, a high level of coordination (PCC = 0.89) was noted between the deltoid group and the adductor group (latissimus dorsi and teres major) during the initial stage of shoulder elevation. Conclusion: The destabilising force of the deltoid during the initial stage of shoulder elevation is balanced by coordinated activity of rotator cuff, latissimus dorsi, and teres major. This is also the case for the end-range of movement, where increased demand for stability again leads to higher coordination between the deltoid and rotator cuff muscle groups. Appreciation of the sophistication of normal shoulder function evidence-based rehabilitation strategies for conditions such as subacromial impingement syndrome or shoulder instability can be developed.

Keywords: shoulder, coordination, EMG, muscle activity, upper limb

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Authors: Tarek S. Duzan, Fisal Ben Ammer, Mohamed Sula

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In some places within Sirt Basin-Libya, it has been noticed that seismic data below pre-upper cretaceous unconformity (PUK) is hopeless to resolve the large-scale structural features and is unable to fully determine reservoir delineation. Seismic artifacts (multiples) are observed in the reservoir zone (Nubian Formation) below PUK, which complicate the process of seismic interpretation. The nature of the unconformity and the structures below are still ambiguous and not fully understood which generates a significant gap in characterizing the geometry of the reservoir, the uncertainty accompanied with lack of reliable seismic data creates difficulties in building a robust geological model. High resolution dipmeter is highly useful in steeply dipping zones. This paper uses FMl and OBMl borehole images (dipmeter) to analyze the structures below the PUK unconformity from two wells drilled recently in the North Gialo field (a mature reservoir). In addition, borehole images introduce new evidences that the PUK unconformity is angular and the bedding planes within the Nubian formation (below PUK) are significantly titled. Structural dips extracted from high resolution borehole images are used to construct a new geological model by the utilization of latest software technology. Therefore, it is important to use the advance well logs technology such as FMI-HD for any future drilling and up-date the existing model in order to minimize the structural uncertainty.

Keywords: FMI (formation micro imager), OBMI (oil base mud imager), UBI (ultra sonic borehole imager), nub sandstone reservoir in North gialo

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Authors: Vera Wilden, Benno Hoffmeister, Georgios Balaskas, Lukas Rauber, Burkhard Walter

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Light-weight timber frame elements represent an efficient structural solution for wooden multistory buildings. The wall elements of such buildings – which act as shear diaphragms- provide lateral stiffness and resistance to wind and seismic loads. The tendency towards multi-story structures leads to challenges regarding the prediction of stiffness, strength and ductility of the buildings. Lightweight timber frame elements are built up of several structural parts (sheeting, fasteners, frame, support and anchorages); each of them contributing to the dynamic response of the structure. This contribution describes the experimental and numerical investigation and development of enhanced lightweight timber frame buildings. These developments comprise high-performance timber frame walls with the variable arrangements of sheathing planes and dissipative anchors at the base of the timber buildings, which reduce damages to the timber structure and can be exchanged after significant earthquakes. In order to prove the performance of the developed elements in the context of a real building a full-scale two-story building core was designed and erected in the laboratory and tested experimentally for its seismic performance. The results of the tests and a comparison of the test results to the predicted behavior are presented. Observation during the test also reveals some aspects of the design and details which need to consider in the application of the timber walls in the context of the complete building.

Keywords: dissipative anchoring, full scale test, push-over-test, wood shear walls

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Authors: Umar Sambo Umar, Ahmad Isah Haruna, Abubakar Sadik Maigari, Muhammad Bello Abubakar

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Schist belts in Nigeria occur prominently west of longitude 80 E and sporadic to the east, they are upper Proterozioc low-medium grade deformed metasediments and metavolcanics that were intruded by Pan-African granitoids. The Wonaka schist belt, though reportedly distinctive in composition and metamorphism, is the least understood; the host for primary gold were not defined, structures which may control primary enrichment have not been delineated. The aim of this work is to determine the relationship between litho-structures and the gold around Wonaka schist belt through geological field mapping, petrographic studies and structural data analysis via ArcGis 10.2, Surfer 11.0 and Stereopro 2.0. The results show that the major rock types are mica schist and migmatites, muscovites detected during microstructural analysis suggests low-grade metamorphism in the metapelites. The shear zones identified were trending North Northeast – South Southwest (NNE-SSW), fractures trend mostly Northeast-Southwest (NE-SW) perpendicular to planes of gneissic foliations, these conform to the late Pan-African deformational episode. Pegmatite lodes, net self-cross cutting quartz veins as well as the quartz stringers hosted by both migmatites and schist are delineated as targets for primary gold mineralization, while major confluences of the streams serve as zones for secondary (placer) gold targets since the streams are dendritic and intermittent.

Keywords: gold mineralization, Nigeria, migmatites, Wonaka schist belt

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Authors: Adenike O. Olatunji-Akioye, Emmanual B Farayola

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In order to improve the animal protein recommended daily intake of Nigerians, there is an upsurge in breeding of hitherto shunned food animals one of which is the rabbit. Radiography and ultrasonography are tools for diagnosing disease and evaluating the anatomical architecture of parts of the body non-invasively. As the rabbit is becoming a more important food animal, to achieve improved breeding of these animals, the best of the species form a breeding stock and will usually depend on breeding soundness which may be evaluated by assessment of the male reproductive organs by these tools. Four male intact rabbits weighing between 1.2 to 1.5 kg were acquired and acclimatized for 2 weeks. Dorsoventral views of the testes were acquired using a digital radiographic machine and a 5 MHz portable ultrasound scanner was used to acquire images of the testes in longitudinal, sagittal and transverse planes. Radiographic images acquired revealed soft tissue images of the testes in all rabbits. The testes lie in individual scrotal sacs sides on both sides of the midline at the level of the caudal vertebrae and thus are superimposed by caudal vertebrae and the caudal limits of the pelvic girdle. The ultrasonographic images revealed mostly homogenously hypoechogenic testes and a hyperechogenic mediastinum testis. The dorsal and ventral poles of the testes were heterogeneously hypoechogenic and correspond to the epididymis and spermatic cord. The rabbit is unique in the ability to retract the testes particularly when stressed and so careful and stressless handling during the procedures is of paramount importance. The imaging of rabbit testes can be safely done using both imaging methods but ultrasonography is a better method of assessment and evaluation of soundness for breeding.

Keywords: breeding soundness, rabbit, radiography, ultrasonography

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Authors: Salima Tabti, Chaima Maouche, Tinhinene Louaileche, Amel Djedouani, Ismail Warad

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Novel Schiff base ligand HL has been synthesized by condensation of aromatic amine and DHA. It was characterized by UV-Vis, FT-IR, SM, NMR (1H, 13C) and also by single-crystal X-ray diffraction. The crystal structure shows that compound crystallized in a triclinic system in P-1 space group and with a two unit per cell (Z = 2).The asymmetric unit, contains one independent molecules, the conformation is determined by an intermolecular N-H…O hydrogen bond with an S(6) ring motif. The molecule have an (E) conformation about the C=N bond. The dihedral angles between the phenyl and pyran ring planes is 89.37 (1), the two plans are approximately perpendicular. The catecholase activity of is situ copper complexes of this ligand has been investigated against catechol. The progress of the oxidation reactions was closely monitored over time following the strong peak of catechol using UV-Vis. Oxidation rates were determined from the initial slope of absorbance. time plots, then analyzed by Michaelis-Menten equations. Catechol oxidation reactions were realized using different concentrations of copper acetate and ligand (L/Cu: 1/1, 1/2, 2/1). The results show that all complexes were able to catalyze the oxidation of catechol. Acetate complexes have the highest activity. Catalysis is a branch of chemical kinetics that, more generally, studies the influence of all physical or chemical factors determining reaction rates. It solves a lot of problems in the chemistry reaction process, especially for a green, economic and less polluting chemistry. For this reason, the search for new catalysts for known organic reactions, occupies a very advanced place in the themes proposed by the chemists.

Keywords: dehydroacetic acid, catechol, copper, catecholase activity, x-ray

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Authors: Subhasisa Nath, David Waugh, Graham Ormondroyd, Morwenna Spear, Andy Pitman, Paul Mason

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Wood is one of the most sustainable and environmentally favourable materials and is chemically treated in timber industries to maximise durability. To increase the chemical preservative uptake and retention by the wood, current limiting incision technologies are commonly used. This work reports the effects of single pulse CO2 laser-incision and frequency tripled Nd:YAG percussion laser-incision on the characteristics of laser-incised holes in the Radiata Pine. The laser-incision studies were based on changing laser wavelengths, energies and focal planes to conclude on an optimised combination for the laser-incision of Radiata Pine. The laser pulse duration had a dominant effect over laser power in controlling hole aspect ratio in CO2 laser-incision. A maximum depth of ~ 30 mm was measured with a laser power output of 170 W and a pulse duration of 80 ms. However, increased laser power led to increased carbonisation of holes. The carbonisation effect was reduced during laser-incision in the ultra-violet (UV) regime. Deposition of a foamy phase on the laser-incised hole wall was evident irrespective of laser radiation wavelength and energy. A maximum hole depth of ~20 mm was measured in the percussion laser-incision in the UV regime (355 nm) with a pulse energy of 320 mJ. The radial and tangential faces had a significant effect on laser-incision efficiency for all laser wavelengths. The laser-incised hole shapes and circularities were affected by the wood anatomy (earlywoods and latewoods in the structure). Subsequently, the mechanism of laser-incision is proposed by analysing the internal structure of laser-incised holes.

Keywords: CO2 Laser, Nd: YAG laser, incision, drilling, wood, hole characteristics

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Authors: Băilă Diana Irinel, Păcurar Răzvan, Păcurar Ancuța

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Although the volumes of fibre reinforced polymer composites (FRPs) used for aircraft applications is a relatively small percentage of total use, the materials often find their most sophisticated applications in this industry. In aerospace, the performance criteria placed upon materials can be far greater than in other areas – key aspects are light-weight, high-strength, high-stiffness, and good fatigue resistance. Composites were first used by the military before the technology was applied to commercial planes. Nowadays, composites are widely used, and this has been the result of a gradual direct substitution of metal components followed by the development of integrated composite designs as confidence in FRPs has increased. The airplane uses a range of components made from composites, including the fin and tailplane. In the last years, composite materials are increasingly used in automotive applications due to the improvement of material properties. In the aerospace and automotive sector, the fuel consumption is proportional to the weight of the body of the vehicle. A minimum of 20% of the cost can be saved if it used polymer composites in place of the metal structures and the operating and maintenance costs are alco very low. Glass fiber-epoxy composites are widely used in the making of aircraft and automobile body parts and are not only limited to these fields but also used in ship building, structural applications in civil engineering, pipes for the transport of liquids, electrical insulators in reactors. This article was establish the high-performance of composite material, a type glass-epoxy used in automotive and aeronautic domains, concerning the tensile and flexural tests and SEM analyzes.

Keywords: glass-epoxy composite, traction and flexion tests, SEM analysis, acoustic emission (AE) signals

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Authors: Wen-Jay Lee, Kuo-Ning Chiang

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The graphene binding with silicon substrate has apparently Schottky barriers property, which can be used in the application of solar cell and light source. Because graphene has only one atom layer, the atomistic structure of graphene binding with the silicon surface plays an important role to affect the properties of graphene. In this work, temperature effect on the morphology of graphene sheet attached on different crystal planes of silicon substrates are investigated by Molecular dynamics (MD) (LAMMPS, developed by Sandia National Laboratories). The results show that the covered graphene sheet would cause the structural deformation of the surface Si atoms of stubtrate. To achieve a stable state in the binding process, the surface Si atoms would adjust their position and fit the honeycomb structure of graphene after the graphene attaches to the Si surface. The height contour of graphene on different plane of silicon surfaces presents different pattern, leading the local residual stress at the interface. Due to the high density of dangling bond on the Si (111)7x7 surface, the surface of Si(111)7x7 is not matching with the graphene so well in contrast with Si(100)2x1and Si(111)2x1. Si(111)7x7 is found that only partial silicon adatoms are rearranged on surface after the attachment when the temperature is lower than 200K, As the temperature gradually increases, the deformation of surface structure becomes significant, as well as the residue stress. With increasing temperature till the 815K, the graphene sheet begins to destroy and mixes with the silicon atoms. For the Si(100)2x1 and Si(111)2x1, the silicon surface structure keep its structural arrangement with a higher temperature. With increasing temperature, the residual stress gradually decrease till a critical temperatures. When the temperature is higher than the critical temperature, the residual stress gradually increases and the structural deformation is found on the surface of the Si substrates.

Keywords: molecular dynamics, graphene, silicon, Schottky barriers, interface

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Authors: Mounir Baccar, Amel Gammoudi, Abdelhak Ayadi

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The efficient mixing of highly viscous fluids is required for many industries such as food, polymers or paints production. The homogeneity is a challenging operation for this fluids type since they operate at low Reynolds number to reduce the required power of the used impellers. Particularly, close-clearance impellers, mainly helical ribbons, are chosen for highly viscous fluids agitated in laminar regime which is currently heated through vessel wall. Indeed, they are characterized by high shear strains closer to the vessel wall, which causes a disturbing thermal boundary layer and ensures the homogenization of the bulk volume by axial and radial vortices. The hydrodynamic and thermal behaviors of Newtonian fluids in vessels agitated by helical ribbon impellers, has been mostly studied by many researchers. However, rarely researchers investigated numerically the agitation of yield stress fluid by means of helical ribbon impellers. This paper aims to study the effect of the Double Helical Ribbon (DHR) stirrers on both the hydrodynamic and the thermal behaviors of yield stress fluids treated in a cylindrical vessel by means of numerical simulation approach. For this purpose, continuity, momentum, and thermal equations were solved by means of 3D finite volume technique. The effect of Oldroyd (Od) and Reynolds (Re) numbers on the power (Po) and Nusselt (Nu) numbers for the mentioned stirrer type have been studied. Also, the velocity and thermal fields, the dissipation function and the apparent viscosity have been presented in different (r-z) and (r-θ) planes.

Keywords: Bingham fluid, Hydrodynamic and thermal behavior, helical ribbon, mixing, numerical modelling

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Authors: Lamees Nasser, Yago Diez, Robert Martí, Joan Martí, Ibrahim Sadek

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Automated 3D breast ultrasound (ABUS) screening is a novel modality in medical imaging because of its common characteristics shared with other ultrasound modalities in addition to the three orthogonal planes (i.e., axial, sagittal, and coronal) that are useful in analysis of tumors. In the literature, few automatic approaches exist for typical tasks such as segmentation or registration. In this work, we deal with two problems concerning ABUS images: nipple and rib detection. Nipple and ribs are the most visible and salient features in ABUS images. Determining the nipple position plays a key role in some applications for example evaluation of registration results or lesion follow-up. We present a nipple detection algorithm based on color and shape of the nipple, besides an automatic approach to detect the ribs. In point of fact, rib detection is considered as one of the main stages in chest wall segmentation. This approach consists of four steps. First, images are normalized in order to minimize the intensity variability for a given set of regions within the same image or a set of images. Second, the normalized images are smoothed by using anisotropic diffusion filter. Next, the ribs are detected in each slice by analyzing the eigenvalues of the 3D Hessian matrix. Finally, a breast mask and a probability map of regions detected as ribs are used to remove false positives (FP). Qualitative and quantitative evaluation obtained from a total of 22 cases is performed. For all cases, the average and standard deviation of the root mean square error (RMSE) between manually annotated points placed on the rib surface and detected points on rib borders are 15.1188 mm and 14.7184 mm respectively.

Keywords: Automated 3D Breast Ultrasound, Eigenvalues of Hessian matrix, Nipple detection, Rib detection

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Authors: Chetna Tyagi. G. B. V. S. Lakshmi, Ambuj Tripathi, D. K. Avasthi

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Graphene oxide provides a good host matrix for preparing nanocomposites due to the different functional groups attached to its edges and planes. Being biocompatible, it is used in therapeutic applications. As enzyme-based biosensor requires complicated enzyme purification procedure, high fabrication cost and special storage conditions, we need enzyme-less biosensors for use even in a harsh environment like high temperature, varying pH, etc. In this work, we have prepared both enzyme-based and enzyme-less graphene oxide-based biosensors for glucose detection using glucose-oxidase as enzyme and gold nanoparticles, respectively. These samples were characterized using X-ray diffraction, UV-visible spectroscopy, scanning electron microscopy, and transmission electron microscopy to confirm the successful synthesis of the working electrodes. Electrochemical measurements were performed for both the working electrodes using a 3-electrode electrochemical cell. Cyclic voltammetry curves showed the homogeneous transfer of electron on the electrodes in the scan range between -0.2V to 0.6V. The sensing measurements were performed using differential pulse voltammetry for the glucose concentration varying from 0.01 mM to 20 mM, and sensing was improved towards glucose in the presence of gold nanoparticles. Gold nanoparticles in graphene oxide nanocomposite played an important role in sensing glucose in the absence of enzyme, glucose oxidase, as evident from these measurements. The selectivity was tested by measuring the current response of the working electrode towards glucose in the presence of the other common interfering agents like cholesterol, ascorbic acid, citric acid, and urea. The enzyme-less working electrode also showed storage stability for up to 15 weeks, making it a suitable glucose biosensor.

Keywords: electrochemical, enzyme-less, glucose, gold nanoparticles, graphene oxide, nanocomposite

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Authors: Behrooz Daneshmand

Abstract:

Software Defined Networking (SDN) is designed to meet the future needs of 5G mobile networks. The SDN architecture offers a new solution that involves separating the control plane from the data plane, which is usually paired together. Network functions traditionally performed on specific hardware can now be abstracted and virtualized on any device, and a centralized software-based administration approach is based on a central controller, facilitating the development of modern applications and services. These plan standards clear the way for a more adaptable, speedier, and more energetic network beneath computer program control compared with a conventional network. We accept SDN gives modern inquire about openings to security, and it can significantly affect network security research in numerous diverse ways. Subsequently, the SDN architecture engages systems to effectively screen activity and analyze threats to facilitate security approach modification and security benefit insertion. The segregation of the data planes and control and, be that as it may, opens security challenges, such as man-in-the-middle attacks (MIMA), denial of service (DoS) attacks, and immersion attacks. In this paper, we analyze security threats to each layer of SDN - application layer - southbound interfaces/northbound interfaces - controller layer and data layer. From a security point of see, the components that make up the SDN architecture have a few vulnerabilities, which may be abused by aggressors to perform noxious activities and hence influence the network and its administrations. Software-defined network assaults are shockingly a reality these days. In a nutshell, this paper highlights architectural weaknesses and develops attack vectors at each layer, which leads to conclusions about further progress in identifying the consequences of attacks and proposing mitigation strategies.

Keywords: software-defined networking, security, SDN, 5G/IMT-2020

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Authors: Valentina Paolucci, Jessica De Santis, Vittorio Ricci, Giacomo Giorgi, Carlo Cantalini

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Despite their potential in gas sensing applications, the major drawback of 2D exfoliated metal dichalcogenides (MDs) is that they suffer from spontaneous oxidation in air, showing poor chemical stability under dry/wet conditions even at room temperature, limiting their practical exploitation. The aim of this work is to validate a synthesis strategy allowing microstructural and electrical stabilization of the oxides that inevitably form on the surface of 2D dichalcogenides. Taking advantage of spontaneous oxidation of MDs in air, we report on liquid phase exfoliated 2D-SnSe2 flakes annealed in static air at a temperature below the crystallization temperature of the native a-SnO2 oxide. This process yields a new class of 2D Layered Amorphous Metal Oxides Sensors (LAMOS), specifically few-layered amorphous a-SnO2, showing excellent gas sensing properties. Sensing tests were carried out at low operating temperature (i.e. 100°C) by exposing a-SnO2 to both oxidizing and reducing gases (i.e. NO2, H2S and H2) and different relative humidities ranging from 40% to 80% RH. The formation of stable nanosheets of amorphous a-SnO2 guarantees excellent reproducibility and stability of the response over one year. These results pave the way to new interesting research perspectives out considering the opportunity to synthesize homogeneous amorphous textures with no grain boundaries, no grains, no crystalline planes with different orientations, etc., following gas sensing mechanisms that likely differ from that of traditional crystalline metal oxide sensors. Moreover, the controlled annealing process could likely be extended to a large variety of Transition Metal Dichalcogenides (TMDs) and Metal Chalcogenides (MCs), where sulfur, selenium, or tellurium atoms can be easily displaced by O2 atoms (ΔG < 0), enabling the synthesis of a new family of amorphous interfaces.

Keywords: layered 2D materials, exfoliation, lamos, amorphous metal oxide sensors

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Authors: Syed Muhammad Basit Ali, Usama Saleem, Irtiza Ali

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Internal combustion engines have been pioneers in the aviation industry, use of piston engines for aircraft propulsion, from propeller-driven bi-planes to turbo-prop, commercial, and cargo airliners. To provide an adequate amount of thrust piston engine rotates the propeller at a specific rpm, allowing enough mass airflow. Thrust is the only forward-acting force of an aircraft that helps heavier than air bodies to fly, depending on the mathematical model and variables included in that with the correct measurement. Test-benches have been a bench-mark in the aerospace industry to analyse the results before a flight, having paramount significance in reliability and safety engineering, depending on the mathematical model and variables included in that with the correct measurement. Calculation of thrust from a piston engine also depends on environmental changes, the diameter of the propeller, and the density of air. The project would be centered on piston engines used in the aviation industry for light aircraft and UAVs. A static thrust test bench involves various units, each performing a designed purpose to monitor and display. Static thrust tests are performed on the ground, and safety concerns hold paramount importance. The execution of this study involves research, design, manufacturing, and results based on reverse engineering initiating from virtual design, analytical analysis, and simulations. The final evaluation of results gathered from various methods such as co-relation between conventional mass-spring and digital loadcell. On average, we received 17.5kg of thrust (25+ engine run-ups – around 40 hours of engine run), only 10% deviation from analytically calculated thrust –providing 90% accuracy.

Keywords: aviation, aeronautics, static thrust, test bench, aircraft maintenance

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Authors: Rahmi Aksoy

Abstract:

The western part of Konya consists of an area of block faulted basin and ranges. Present day topography is characterized by alternating elongate mountains and depressions trending east-west. A number of depressions occur in the region. One of the large depressions is the E-W trending Kızılören-Küçükmuhsine (KK basin) basin bounded on both sides by normal faults and located on the west of the Konya city. The basin is about 5-12 km wide and 40 km long. Ranges north and south of the basin are composed of undifferentiated low grade metamorphic rocks of Silurian-Cretaceous age and smaller bodies of ophiolites of probable Cretaceous age. The basin fill consists of the upper Miocene-lower Pliocene fluvial, lacustrine, alluvial sediments and volcanic rocks. The younger and undeformed Plio-Quaternary basin fill unconformably overlies the older basin fill and is composed predominantly of conglomerate, mudstone, silt, clay and recent basin floor deposits. The paleostress data on the striated fault planes in the basin indicates NW-SE extension and associated with an NE-SW compression. The eastern end of the KK basin is cut and terraced by the active Konya fault zone. The Konya fault zone is NE trending, east dipping normal fault forming the western boundary of the Konya depression. The Konya depression consists mainly of Plio-Quaternary alluvial complex and recent basin floor sediments. The structural data gathered from the Konya fault zone support normal faulting with a small amount of dextral strike-slip tensional tectonic regime that shaped under the WNW-ESE extensional stress regime.

Keywords: central Anatolia, fault kinematics, Kızılören-Küçükmuhsine basin, Konya fault zone, neotectonics

Procedia PDF Downloads 332