Search results for: corporate structure

Authors: Yaofei Jiang, Liangqing Wang, Yanjun Xu

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In recent years, geological explorations have been carried out on the Rumei hydropower station, China. After preliminary analysis of results, the mainly problem of slope in reservoir area is about the stability of accumulation body. It is found that there are 23 accumulations in various sizes in the reservoir area, and most of them are unfavorable geological bodies. Three typical (No. 1, 7, 17) accumulation body slopes were selected as subjects to investigate the stability of the slopes. Take No. 1 accumulation body slope as an example and basic geological condition investigation and formation mechanism analysis were carried out to study the stability and geological analysis of engineering influence of the slope. The accumulation body in the research area distributes along the river with natural slope of 32° ~ 37° which is the natural angle of repose of gravel. The formation mechanism is analyzed based on the composition and structure of the accumulation body. The middle and lower part of the body is dense full of gravel soil mixed with a small amount of sand gravel which is stable. In the upper part, gravel soil is interbedded with bad cemented gravel which as a weak surface is not conducive to slope stability. Under the natural condition before storing water, the underground water level is deep buried, mainly distributed in the bedrock, and the surface and groundwater discharge conditions of the accumulation body are good, which is beneficial to the stability of slope. The safety coefficient calculated by the limit equilibrium method is 1.14, which indicates the slope is basically stable. However, the safety coefficient drops to 1.02 when the normal storage level is 2895m, which is in a dangerous state. The accumulation body will be destabilized by a small-area instability to large-scale or overall instability.

Keywords: accumulation body slope, stability evaluation, geological engineering investigation, effect of storing water

Procedia PDF Downloads 166

Authors: Lina F. Ballesteros, Hafsae Lamsaf, Miguel A. Cerqueira, Lorenzo M. Pastrana, Sandra Carvalho, Jose A. Teixeira, S. Calderon V.

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The use of bio-based packaging materials containing metallic and bimetallic nanostructures is relatively modern technology. In this sense, the food packaging industry has been investigating biological and renewable resources that can replace petroleum-based materials to reduce the environmental impact and, at the same time, including new functionalities using nanotechnology. Therefore, the main objective of the present work consisted of developing bio-based poly-lactic acid (PLA) films with Zinc (Zn) and Zinc-Iron (Zn-Fe) nanostructures deposited by magnetron sputtering. The structural, antimicrobial, and optical properties of the films were evaluated when exposed at 60% and 96% relative humidity (RH). The morphology and elemental analysis of the samples were determined by scanning (transmission) electron microscopy (SEM and STEM), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The structure of the PLA was monitored before and after deposition by Fourier transform infrared spectroscopy (FTIR) analysis, and the antimicrobial and color assays were performed by using the zone of inhibition (ZOI) test and a Minolta colorimeter, respectively. Finally, the films were correlated in terms of the deposit conditions, Zn or Zn-Fe concentrations, and thickness. The results revealed PLA films with different morphologies, compositions, and thicknesses of Zn or Zn-Fe nanostructures. The samples showed a significant antibacterial and antifungal activity against E. coli, P. aeruginosa, P. fluorescens, S. aureus, and A. niger, and considerable changes of color and opacity at 96% RH, especially for the thinner nanostructures (150-250 nm). On the other hand, when the Fe fraction was increased, the lightness of samples increased, as well as their antimicrobial activity when compared to the films with pure Zn. Hence, these findings are relevant to the food packaging field since intelligent and active films with multiple properties can be developed.

Keywords: biopolymers, functional properties, magnetron sputtering, Zn and Zn-Fe nanostructures

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Authors: Ainur Mukhambetova, Miras Karzhauov, Vyacheslav Ogay

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Introduction: Mesenchymal stem cells (MSCs) have the capacity to be differentiated into several cell lineages and are a promising source for cell therapy and tissue engineering. However, currently most MSCs culturing protocols use media supplemented with fetal bovine serum (FBS), which limits their application in clinic due to the possibility of zoonotic infections, contamination and immunological reactions. Consequently, formulating effective serum free culture medium becomes one of the important problems in contemporary cell biotechnology. Objectives: The aim of this study was to define an optimal serum-free medium for culturing of periosteum derived MSCs. Materials and methods: The MSCs were extracted from human periosteum and transferred to the culture flasks pretreated with CELLstart™. Immunophenotypic characterization, proliferation and in vitro differentiation of cells grown on STEM PRO® MSC SFM were compared to the cells cultured in the standard FBS containing media. Chromosome analysis and flow cytometry were also performed. Results: We have shown that cells were grown on STEM PRO® MSC SFM retained all the morphological, immunophenotypic (CD73, CD90, CD105, vimentin and Stro-1) and cell differentiation characteristics specific to MSCs. Chromosome analysis indicated no anomalies in the chromosome structure. Flow cytometry showed a high expression of cell adhesion molecules CD44 (98,8%), CD90 (97,4%), CD105 (99,1%). In addition, we have shown that cell is grown on STEM PRO® MSC SFM have higher proliferation capacity compared to cell expanded on standard FBS containing the medium. Conclusion: We have shown that STEM PRO® MSC SFM is optimal for culturing periosteum derived human MSCs which subsequently can be safely used in cell therapy.

Keywords: cell technologies, periosteum-derived MSCs, regenerative medicine, serum-free medium

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Authors: Sreejani Barua, P. P. Srivastav

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Formulation of new functional food products for diabetes patients and obsessed people is a challenge for food industries till date. Starch is a certainly happening, ecological, reasonable and profusely obtainable polysaccharide in plant material. In the present scenario, there is a great interest in modifying starch functional properties without destroying its granular structure using different modification techniques. Resistant starch (RS) contains almost zero calories and can control blood glucose level to prevent diabetes. The current study focused on modification of mung bean starch which is a good source of legumes carbohydrate for the production of functional food. Heat moisture treatment (HMT) of mung starch was conducted at moisture content of 10-30%, temperature of 80-120 °C and time of 8-24 h.The content of resistant starch after modification was significantly increased from native starches containing RS 7.6%. The design combinations of HMT had been completed through Central Composite Rotatable Design (CCRD). The effects of HMT process variables on the yield of resistant starch was studied through Rapid Surface Methodology (RSM). The highest increase of resistant starch was found up to 34.39% when treated the native starch with 30% m.c at 120 °C temperature for 24 h.The functional properties of both native and modified mung bean starches showed that there was a reduction in the swelling power and swelling volume of HMT starches. However, the solubility of the HMT starches was higher than that of untreated native starch and also observed change in structural (scanning electron microscopy), X-Ray diffraction (XRD) pattern, blue value and thermal (differential scanning calorimetry) properties. Therefore, replacing native mung bean starch with heat-moisture treated mung bean starch leads to the development of new products with higher resistant starch levels and functional properties.

Keywords: Mung bean starch, heat moisture treatment, functional properties, resistant starch

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Authors: Rajai Al-Rousan

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The repair and strengthening of concrete structures is a big challenge for the concrete industry for both engineers and contractors. Due to increasing economical constraints, the current trend is to repair/upgrade deteriorated and functionally obsolete structures rather than replacing them with new structures. CFRP has been used previously by air space industries regardless of the high costs. The decrease in the costs of the composite materials, as results of the technology improvement, has made CFRP an alternative to conventional materials for many applications. The primary objective of this research is to investigate the flexural behavior of reinforced concrete (RC) beams externally strengthened with CFRP composites exposed for three years for the following conditions: (a) room temperature, (b) cyclic ponding in 15% salt-water solution, (c) hot-water of 65oC, and (d) rapid freeze/thaw cycles. Results indicated that the after three years of various environmental conditions, the bond strength between the concrete beams and CFRP sheets was not affected. No signs of separation or debonding of CFRP sheets were observed before testing. Also, externally strengthening RC beams with CFRP sheets leads to a substantial increase in the ductility of concrete structures. This is a result of forcing the concrete to undergo inelastic deformation, resulting in compression failure of the structure after yielding of steel reinforcement. In addition, exposure to heat water tank for three years reduces the ultimate load by about 11%. This 11% reduction in the ultimate load equates to about 53%, 46% and 68% loss of the gain of the strength attributed to the CFRP of 2/3 Layer, 1 Layers and 2 Layers CFRP Sheets respectively. This mean that with decreasing of number of layers the environmental exposure had an efficient effect on concrete by protection concrete from environmental effect and adverse effect on the bond performance.

Keywords: flexural, behavior, CFRP, composites, environment, conditions

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Authors: Hirokatsu Kawashima

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One important element of teaching/learning listening is intensive listening such as listening for precise sounds, words, grammatical, and semantic units. Several classroom-based investigations have been conducted to explore the usefulness of auditory recognition of phonological, grammatical and semantic errors in such a context. The current study reports the results of one such investigation, which targeted auditory recognition of phonological, grammatical, and semantic errors at the sentence level. 56 Japanese EFL learners participated in this investigation, in which their recognition performance of phonological, grammatical and semantic errors was measured on a 9-point scale by learners’ self-evaluation from the perspective of 1) two types of similar English sound (vowel and consonant minimal pair words), 2) two types of sentence word order (verb phrase-based and noun phrase-based word orders), and 3) two types of semantic consistency (verb-purpose and verb-place agreements), respectively, and their general listening proficiency was examined using standardized tests. A number of findings have been made about the interactive relationships between the three types of auditory error recognition and general listening proficiency. Analyses based on the OPLS (Orthogonal Projections to Latent Structure) regression model have disclosed, for example, that the three types of auditory error recognition are linked in a non-linear way: the highest explanatory power for general listening proficiency may be attained when quadratic interactions between auditory recognition of errors related to vowel minimal pair words and that of errors related to noun phrase-based word order are embraced (R2=.33, p=.01).

Keywords: auditory error recognition, intensive listening, interaction, investigation

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Authors: Sajjad Seifi Mofarah, S. K. Sadrnezhaad, Shokooh Moghadam, Javad Tavakoli

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In recent years a new method of combination treatment for cancer has been developed and studied that has led to significant advancements in the field of cancer therapy. Hyperthermia is a traditional therapy that, along with a creation of a medically approved level of heat with the help of an alternating magnetic AC current, results in the destruction of cancer cells by heat. This paper gives details regarding the production of the spherical nanocomposite PVA/γ-Fe2O3 in order to be used for medical purposes such as tumor treatment by hyperthermia. To reach a suitable and evenly distributed temperature, the nanocomposite with core-shell morphology and spherical form within a 100 to 200 nanometer size was created using phase separation emulsion, in which the magnetic nano-particles γ-Fe2O3 with an average particle size of 20 nano-meters and with different percentages of 0.2, 0.4, 0.5, and 0.6 were covered by polyvinyl alcohol. The main concern in hyperthermia and heat treatment is achieving desirable specific absorption rate (SAR) and one of the most critical factors in SAR is particle size. In this project all attempts has been done to reach minimal size and consequently maximum SAR. The morphological analysis of the spherical structure of the nanocomposite PVA/γ-Fe2O3 was achieved by SEM analyses and the study of the chemical bonds created was made possible by FTIR analysis. To investigate the manner of magnetic nanocomposite particle size distribution a DLS experiment was conducted. Moreover, to determine the magnetic behavior of the γ-Fe2O3 particle and the nanocomposite PVA/γ-Fe2O3 in different concentrations a VSM test was conducted. To sum up, creating magnetic nanocomposites with a spherical morphology that would be employed for drug loading opens doors to new approaches in developing nanocomposites that provide efficient heat and a controlled release of drug simultaneously inside the magnetic field, which are among their positive characteristics that could significantly improve the recovery process in patients.

Keywords: nanocomposite, hyperthermia, cancer therapy, drug releasing

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Authors: Malihe Moeinin, Robert Hill, Ferranti Wong

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Background: A white spot lesion (WSL) is defined as subsurface enamel porosity from carious demineralisation on the smooth surfaces of the tooth. It appears as a milky white opacity. Lesions shown an apparently intact surface layer, followed underneath by the more porous lesion body. The small pores within the body of the lesion act as diffusion pathway for both acids and minerals, so allowing the demineralisation of enamel to occur at the advancing front of the lesion. Objectives: The objective is to mapthe porosity and its size on WSL with Focused Ion Bean- Scanning Electron Microscopy (FIB-SEM) Method: The basic method used for FIB-SEM consisted of depositing a one micron thick layer of platinum over 25μmx 25μm of the interest region of enamel. Then, making a rough cut (25μmx 5μmx 20μm) with 3nA current and 30Kv was applied with the help of drift suppression (DS), using a standard “cross-sectional” cutting pattern, which ended at the front of the deposited platinum layer. Two adjacent areas (25μmx 5μmx 20μm) on the both sides of the platinum layer were milled under the same conditions. Subsequent, cleaning cross-sections were applied to polish the sub-surface edge of interest running perpendicular to the surface. The "slice and view" was carried out overnight for milling almost 700 slices with 2Kv and 4nA and taking backscattered (BS) images. Then, images were imported into imageJ and analysed. Results: The prism structure is clearly apparent on FIB-SEM slices of WSL with the dissolution of prism boundaries as well as internal porosity within the prism itself. Porosity scales roughly 100-400nm, which is comparable to the light wavelength (500nm). Conclusion: FIB-SEM is useful to characterize the porosity of WSL and it clearly shows the difference between WSL and normal enamel.

Keywords: white spot lesion, FIB-SEM, enamel porosity, porosity

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Authors: Jenyu Peng

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Incestuous abuse can be considered a form of domestic violence that exemplifies gender inequality. It challenges the common image of home as “haven of safety”. In Taiwan, even after years of feminist NGOs’ effort to encourage victims to speak up, the shared cultural representations of family, still praising piety towards the parents, seem to keep the incest trauma in secret. As clinical practitioners have observed, most devastating psychological sequels of incest trauma are often related to silencing. Thus one can expect that in families centered cultures, the difficulties for victims to disclose are greater, and the traumatic consequences more severe. This poses crucial therapeutic issues for clinicians working in those cultures. Since 2009, the author, a trained psychoanalyst and researcher, has been conducting “clinical fieldwork” on incest trauma in Taiwan. Employing ethnographical method, our theoretical references are both psychoanalytical and anthropological. The necessity of interdisciplinary efforts in incest trauma research will be addressed and discussed. The analyses of the present paper will focus on five incestuous families: four Han families, and one aboriginal. Although Taiwanese aboriginal peoples have been pretty much sinicized since decades, it is worth observing the convergent and divergent aspects in these two cultures. Moreover, findings of a previous research conducted in France during 2002-2004 will serve as background for the purpose of comparison. The results will be presented along with three questions: 1) How the perception of family influences the process of disclosure? 2) How the incestuous experience comes into play with victims’ gender identity and sexuality, pivotal for the subjectification? 3) How victims more successful in gendered subjectification modify their dynamics with their traumatizing family? This research finds that most victims tend to defend their own incestuous families, and that victims’ subjectivity and agency are actually entangled in the power structure of incestuous family.

Keywords: incestuous family, subjectification, gender identity, agency

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Authors: Hadach Fatiha, Algouti Ahmed, Algouti Abdellah, Jdaba Naji, Es-Sarrar Othman, Mourabit Zahra

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This paper investigates the structure and evolution of diapirism in the Ait Ourir basin, located in the High Atlas of Marrakesh, using structural and sedimentological fieldwork integrated with field mapping. A tectonic-sedimentological study of the Mesozoic cover of the Ait Ourir basin area revealed that these units were subjected to important saccadic halokinetic activity, reflected by anticline structures associated with regional faults that created several synclinal mini-basins. However, the lack of seismic coverage in the study area makes the proposed interpretation based on extrapolations of information observed on the surface. In this work, we suggest that faults and salt activity led to the formation of different structures within the studied area. The growth of the Triassic evaporites at different stages during the Mesozoic is reflected by progressive and local unconformities, recorded as having different ages. These structures created high diapiric zones with reduced sedimentation, showing abrupt lateral thickness variations in several places where this activity was occurring; this is clearly defined within the Wanina and Jbel Sour’s mini-basins, where the Senonian was observed to rest at an angular unconformity over the entire sedimentary cover encompassing the time period from the Liassic to the Turonian. The diapirism associated with the major faults, especially encountered between the basins, is often accompanied by late Triassic volcanic material. This diapir-fault relationship resulted in shallow and often depocentric zones in a pull-apart system within a distensive context.

Keywords: diapir, evaporites, faults, pull-apart, Mesozoic cover, Ait Ourir, western High Atlas, Morocco

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Authors: Kang Shuo-Shuo, Li Jian-Nan, Yang Shiming

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Purpose: The three-dimensional anatomical structure of the facial nerve recess and its relationship were measured by high-resolution temporal bone CT to provide imaging reference for cochlear implant operation. Materials and Methods: By analyzing the high-resolution CT of 160 cases (320 pleural ears) of the temporal bone, the following parameters were measured at the axial window niche level: 1. The distance between the facial nerve and chordae tympani nerve d1; 2. Distance between the facial nerve and circular window niche d2; 3. The relative Angle between the facial nerve and the circular window niche a; 4. Distance between the middle point of the face recess and the circular window niche d3; 5. The relative angle between the middle point of the face recess and the circular window niche b. Factors that might influence the anatomy of the facial recess were recorded, including the patient's sex, age, and anatomical variation (e.g., vestibular duct dilation, mastoid gas type, mothoid sinus advancement, jugular bulbar elevation, etc.), and the correlation between these factors and the measured facial recess parameters was analyzed. Result: The mean value of face-drum distance d1 is (3.92 ± 0.26) mm, the mean value of face-niche distance d2 is (5.95 ± 0.62) mm, the mean value of face-niche Angle a is (94.61 ± 9.04) °, and the mean value of fossa - niche distance d3 is (6.46 ± 0.63) mm. The average fossa-niche Angle b was (113.47 ± 7.83) °. Gender, age, and anterior sigmoid sinus were the three factors affecting the width of the opposite recess d1, the Angle of the opposite nerve relative to the circular window niche a, and the Angle of the facial recess relative to the circular window niche b. Conclusion: High-resolution temporal bone CT before cochlear implantation can show the important anatomical relationship of the facial nerve recess, and the measurement results have clinical reference value for the operation of cochlear implantation.

Keywords: cochlear implantation, recess of facial nerve, temporal bone CT, three-dimensional measurement

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Authors: D. Miroud, H. Mokaddem, M. Tata, N. Foucha

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The body of PDC (polycrystalline diamond compact) drill bit can be manufactured from two different materials, steel and tungsten carbide matrix. Commonly the steel body is produced by machining, thermal spraying a bonding layer and hardfacing of Ni-based matrix reinforced with fused eutectic tungsten carbide (WC/W2C). The matrix body bit is manufactured by infiltrating tungsten carbide particles, with a Copper binary or ternary alloy. By erosion-corrosion mechanisms, the PDC drill bits matrix undergoes severe damage, occurring particularly around the PDC inserts and near injection nozzles. In this study, we investigated the possibility to repair the damaged matrix regions by hardfacing technic. Ni-based hardfacing alloy reinforced with fused eutectic tungsten carbide is deposited on infiltrated WC-W-Ni substrate by oxyacetylene welding (OAW). The microstructure at the hardfacing / matrix interface is characterized by SEM- EDS, XRD and micro hardness Hv0.1. The hardfacing conditions greatly affect the dilution phenomenon and the distribution of carbides at the interface, without formation of transition zone. During OAW welding deposition, interdiffusion of atoms occurs: Cu and Sn diffuse from infiltrated matrix substrate into hardfacing and simultaneously Cr and Si alloy elements from hardfacing diffuse towards the substrate. The dilution zone consists of a nickel-rich phase with a heterogeneous distribution of eutectic spherical (Ni-based hardfacing alloy) and irregular (matrix) WC/W2C carbides and a secondary phase rich in Cr-W-Si. Hardfacing conditions cause the dissolution of banding around both spherical and irregular carbides. The micro-hardness of interface is significantly improved by the presence of secondary phase in the inter-dendritic structure.

Keywords: dilution, dissolution, hardfacing, infiltrated matrix, PDC drill bits

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Authors: Ainouna Bouziane

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The ability of Electron Tomography to recover the 3D structure of catalysts, with spatial resolution in the subnanometer scale, has been widely explored and reviewed in the last decades. A variety of experimental techniques, based either on Transmission Electron Microscopy (TEM) or Scanning Transmission Electron Microscopy (STEM) have been used to reveal different features of nanostructured catalysts in 3D, but High Angle Annular Dark Field imaging in STEM mode (HAADF-STEM) stands out as the most frequently used, given its chemical sensitivity and avoidance of imaging artifacts related to diffraction phenomena when dealing with crystalline materials. In this regard, our group has developed a methodology that combines image denoising by undecimated wavelet transforms (UWT) with automated, advanced segmentation procedures and parameter selection methods using CS-TVM (Compressed Sensing-total variation minimization) algorithms to reveal more reliable quantitative information out of the 3D characterization studies. However, evaluating the accuracy of the magnitudes estimated from the segmented volumes is also an important issue that has not been properly addressed yet, because a perfectly known reference is needed. The problem particularly complicates in the case of multicomponent material systems. To tackle this key question, we have developed a methodology that incorporates volume reconstruction/segmentation methods. In particular, we have established an approach to evaluate, in quantitative terms, the accuracy of TVM reconstructions, which considers the influence of relevant experimental parameters like the range of tilt angles, image noise level or object orientation. The approach is based on the analysis of material-realistic, 3D phantoms, which include the most relevant features of the system under analysis.

Keywords: electron tomography, supported catalysts, nanometrology, error assessment

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Authors: Fangyuan Shao, Wei Liu, Deli Gao

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Polycrystalline diamond compact (PDC) bits have occupied a large market of unconventional oil and gas drilling. The application of PDC bits benefits from the efficient rock breaking of PDC cutters. In response to increasingly complex formations, many shaped cutters have been invited, but many of them have not been solved by the mechanism of rock breaking. In this paper, two kinds of PDC cutters: a new axe-shaped (NAS) cutter and cylindrical cutter (benchmark) were studied by laboratory experiments. NAS cutter is obtained by optimizing two sides of axe-shaped cutter with curved surfaces. All the cutters were put on a vertical turret lathe (VTL) in the laboratory for cutting tests. According to the cutting distance, the VTL tests can be divided into two modes: single-turn rotary cutting and continuous cutting. The cutting depth of cutting (DOC) was set at 1.0 mm and 2.0 mm in the former mode. The later mode includes a dry VTL test for thermal stability and a wet VTL test for wear resistance. Load cell and 3D optical profiler were used to obtain the value of cutting forces and wear area, respectively. Based on the findings of the single-turn rotary cutting VTL tests, the performance of A NAS cutter was better than the benchmark cutter on elastoplastic material cutting. The cutting forces (normal forces, tangential force, and radial force) and special mechanical energy (MSE) of a NAS cutter were lower than that of the benchmark cutter under the same condition. It meant that a NAS cutter was more efficient on elastoplastic material breaking. However, the wear resistance of a new axe-shaped cutter was higher than that of a benchmark cutter. The results of the dry VTL test showed that the thermal stability of a NAS cutter was higher than that of a benchmark cutter. The cutting efficiency can be improved by optimizing the geometric structure of the PDC cutter. The change of thermal stability may be caused by the decrease of the contact area between cutter and rock at given DOC. The conclusions of this paper can be used as an important reference for PDC cutters designers.

Keywords: axe-shaped cutter, PDC cutter, rotary cutting test, vertical turret lathe

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Authors: Amna J. Ghith, Khaled Abu Zid, Khairia Youssef, Nasser Saad

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Backgrounds: The multikinase and vascular endothelial growth factor (VEGF) receptor inhibitors interrupt the pathway by which angiogenesis becomes established and promulgated, resulting in the inadequate nourishment of metastatic disease. VEGFR-2 has been the principal target of anti-angiogenic therapies. We disclose the new thieno pyrimidines as inhibitors of VEGFR-2 designed by a molecular modeling approach with increased synergistic activity and decreased side effects. Purpose: 2-substituted thieno pyrimidines are designed and synthesized with anticipated anticancer activity based on its in silico molecular docking study that supports the initial pharmacophoric hypothesis with a same binding mode of interaction at the ATP-binding site of VEGFR-2 (PDB 2QU5) with high docking score. Methods: A series of compounds were designed using discovery studio 4.1/CDOCKER with a rational that mimic the pharmacophoric features present in the reported active compounds that targeted VEGFR-2. An in silico ADMET study was also performed to validate the bioavailability of the newly designed compounds. Results: The Compounds to be synthesized showed interaction energy comparable to or within the range of the benzimidazole inhibitor ligand when docked with VEGFR-2. ADMET study showed comparable results most of the compounds showed absorption within (95-99) zone varying according to different substitutions attached to thieno pyrimidine ring system. Conclusions: A series of 2-subsituted thienopyrimidines are to be synthesized with anticipated anticancer activity and according to docking study structure requirement for the design of VEGFR-2 inhibitors which can act as powerful anticancer agents.

Keywords: docking, discovery studio 4.1/CDOCKER, heterocycles based anticancer agents, 2-subsituted thienopyrimidines

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Authors: Alireza Taghdiri, Sara Ghanbarzade Ghomi

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Existing buildings are permanently subjected to change, continuously renovated and repaired in their long service life. Old buildings are destroyed and their material and components are recycled or reused for constructing new ones. In this process, importance of sustainability principles for building construction is obviously known and great significance must be attached to consumption of resources, resulting effects on the environment and economic costs. Utilization strategies for extending buildings service life and delay in destroying have positive effect on environment protection. In addition, simpler alterability or expandability of buildings’ structures and reducing energy and natural resources consumption have benefits for users, producers and environment. To solve these problems, by applying theories of open building, structural components of some conventional building systems have been analyzed and then, a new geometry adaptive building system is developed which can transform and support different imposed loads. In order to achieve this goal, various research methods and tools such as professional and scientific literatures review, comparative analysis, case study and computer simulation were applied and data interpretation was implemented using descriptive statistics and logical arguments. Therefore, hypothesis and proposed strategies were evaluated and an adaptable and reusable 2-dimensional building system was presented which can respond appropriately to dwellers and end-users needs and provide reusability of structural components of building system in new construction or function. Investigations showed that this incremental building system can be successfully applied in achieving the architectural design objectives and by small modifications on components and joints, it is easy to obtain different and adaptable load-optimized component alternatives for flexible spaces.

Keywords: adaptability, durability, open building, service life, structural building system

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Authors: Ibrahim Hakeem

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Biosolids are stabilised sewage sludge produced from wastewater treatment processes. Biosolids contain valuable plant nutrient which facilitates their beneficial reuse in agricultural land. However, the increasing levels of legacy and emerging contaminants such as heavy metals (HMs), PFAS, microplastics, pharmaceuticals, microbial pathogens etc., are restraining the direct land application of biosolids. Pyrolysis of biosolids can effectively degrade microbial and organic contaminants; however, HMs remain a persistent problem with biosolids and their pyrolysis-derived biochar. In this work, we demonstrated the integrated processing of biosolids involving the acid pre-treatment for HMs removal and selective reduction of ash-forming elements followed by the bench-scale pyrolysis of the treated biosolids to produce quality biochar and bio-oil enriched with valuable platform chemicals. The pre-treatment of biosolids using 3% v/v H₂SO₄ at room conditions for 30 min reduced the ash content from 30 wt% in raw biosolids to 15 wt% in the treated sample while removing about 80% of limiting HMs without degrading the organic matter. The preservation of nutrients and reduction of HMs concentration and mobility via the developed hydrometallurgical process improved the grade of the treated biosolids for beneficial land reuse. The co-removal of ash-forming elements from biosolids positively enhanced the fluidised bed pyrolysis of the acid-treated biosolids at 700 ℃. Organic matter devolatilisation was improved by 40%, and the produced biochar had higher surface area (107 m²/g), heating value (15 MJ/kg), fixed carbon (35 wt%), organic carbon retention (66% dry-ash free) compared to the raw biosolids biochar with surface area (56 m²/g), heating value (9 MJ/kg), fixed carbon (20 wt%) and organic carbon retention (50%). Pre-treatment also improved microporous structure development of the biochar and substantially decreased the HMs concentration and bioavailability by at least 50% relative to the raw biosolids biochar. The integrated process is a viable approach to enhancing value recovery from biosolids.

Keywords: biosolids, pyrolysis, biochar, heavy metals

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Authors: Lu Ren, You-Liang Fang, Yan-Gang Zhao

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In recent years, the application of BIM (Building Information Modelling) to construction schedule plan has been the focus of more and more researchers. In order to assess the reasonable level of the BIM-based construction schedule plan, that is whether the schedule can be completed on time, some researchers have introduced reliability theory to evaluate. In the process of evaluation, the uncertain factors affecting the construction schedule plan are regarded as random variables, and probability distributions of the random variables are assumed to be normal distribution, which is determined using two parameters evaluated from the mean and standard deviation of statistical data. However, in practical engineering, most of the uncertain influence factors are not normal random variables. So the evaluation results of the construction schedule plan will be unreasonable under the assumption that probability distributions of random variables submitted to the normal distribution. Therefore, in order to get a more reasonable evaluation result, it is necessary to describe the distribution of random variables more comprehensively. For this purpose, cubic normal distribution is introduced in this paper to describe the distribution of arbitrary random variables, which is determined by the first four moments (mean, standard deviation, skewness and kurtosis). In this paper, building the BIM model firstly according to the design messages of the structure and making the construction schedule plan based on BIM, then the cubic normal distribution is used to describe the distribution of the random variables due to the collecting statistical data of the random factors influencing construction schedule plan. Next the reliability analysis of the construction schedule plan based on BIM can be carried out more reasonably. Finally, the more accurate evaluation results can be given providing reference for the implementation of the actual construction schedule plan. In the last part of this paper, the more efficiency and accuracy of the proposed methodology for the reliability analysis of the construction schedule plan based on BIM are conducted through practical engineering case.

Keywords: BIM, construction schedule plan, cubic normal distribution, reliability analysis

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Authors: Ljubica Dokić, Ivana Nikolić, Dragana Šoronja–Simović, Zita Šereš, Biljana Pajin, Nils Juul, Nikola Maravić

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The possibility of application the dietary fibers in production of crackers was observed in this work, as well as their influence on rheological and textural properties on the dough for crackers and influence on sensory properties of obtained crackers. Three different dietary fibers, oat, potato and pea fibers, replaced 10% of wheat flour. Long fermentation process and baking test method were used for crackers production. The changes of dough for crackers were observed by rheological methods of determination the viscoelastic dough properties and by textural measurements. Sensory quality of obtained crackers was described using quantity descriptive method (QDA) by trained members of descriptive panel. Additional analysis of crackers surface was performed by videometer. Based on rheological determination, viscoelastic properties of dough for crackers were reduced by application of dietary fibers. Manipulation of dough with 10% of potato fiber was disabled, thus the recipe modification included increase in water content at 35%. Dough compliance to constant stress for samples with dietary fibers decreased, due to more rigid and stiffer dough consistency compared to control sample. Also, hardness of dough for these samples increased and dough extensibility decreased. Sensory properties of final products, crackers, were reduced compared to control sample. Application of dietary fibers affected mostly hardness, structure and crispness of the crackers. Observed crackers were low marked for flavor and taste, due to influence of fibers specific aroma. The sample with 10% of potato fibers and increased water content was the most adaptable to applied stresses and to production process. Also this sample was close to control sample without dietary fibers by evaluation of sensory properties and by results of videometer method.

Keywords: crackers, dietary fibers, rheology, sensory properties

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Authors: Maryam Jaberi, Siavosh Shayan, Mojtaba Yamani

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Habble-Rud River basin (HR), up to 100 km length, one of the largest watersheds which drain into deserts to the north of Central Iran (Dasht-e Kavir). This stream is oblique with the NE-SW trending, flow in the southern range of central Alborz Mountains and the northern border of Central Iran. The end of the ~17 km suddenly change direction and with the southern trending to have a morphology which meanders passes through the Alborz Mountain ridge and flows into the Garmsar plain where it forms one of the largest alluvial fans in Iran, i.e. the vast Garmsar alluvial fan with an area of 476 km2. This study was carried out through morphometric analyses, longitudinal river profiles, and study of geomorpholic evidence such as fluvial terraces, gypsum-salt domes, seismic data, and satellite images. This study aimed to investigate the changes in the pattern of rivers in the southern part of the HR river basin. The southern part of HR river basin located at the southern foothills of the Central Alborz is characterized the thrust faults (Sorkheh-Kalut and Garmsar faults), folds,diapirs and arid climate. The activity of more than 10 salt domes that belong to the Oligocene-Miocene period has considerably influenced the pattern of streams in this region. Dissolution of these domes has not only reduced the quality of water and soil resources, but also has led to the formation of badlands and gullies.Our results indicated that the pattern of rivers in the southern part of HR river basin was influenced by discharge of the HR river in Quaternary, geological structure, subsidence of Central Iran and vertical uplift of Alborz mountain. These agents caused the formation meanders in the southern part of the HR River and evaluation of the seasonal rivers like Shoor-Darre and Garmabsar.

Keywords: geomorphologic evaluation, rivers pattern, Habble-Rud River basin, seasonal rivers

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Authors: Karen G. Bastidas Gomez, Hugo R. Zea Ramirez, Manuel F. Ribeiro Pereira, Cesar A. Sierra Avila, Juan A. Clavijo Morales

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The contamination of water sources with heavy metals such as mercury has been an environmental problem; it has generated a high impact on the environment and human health. In countries such as Colombia, mercury contamination due to mining has reached levels much higher than the world average. This work proposes the use of fique fibers as adsorbent in mercury removal. The evaluation of the material was carried out under five different conditions (raw, pretreated by organosolv, functionalized by TEMPO oxidation, fiber functionalized plus MOF-199 and fiber functionalized plus MOF-199-SH). All the materials were characterized using FTIR, SEM, EDX, XRD, and TGA. Regarding the mercury removal, it was done under room pressure and temperature, also pH = 7 for all materials presentations, followed by Atomic Absorption Spectroscopy. The high cellulose content in fique is the main particularity of this lignocellulosic biomass since the degree of oxidation depends on the number of hydroxyl groups on the surface capable of oxidizing into carboxylic acids, a functional group capable of increasing ion exchange with mercury in solution. It was also expected that the impregnation of the MOF would increase the mercury removal; however, it was found that the functionalized fique achieved a greater percentage of removal, resulting in 81.33% of removal, 44% for the fique with the MOF-199 and 72% for the MOF-199-SH with. The pretreated fiber and raw also showed 74% and 56%, respectively, which indicates that fique does not require considerable modifications in its structure to achieve good performances. Even so, the functionalized fiber increases the percentage of removal considerably compared to the pretreated fique, which suggests that the functionalization process is a feasible procedure to apply with the purpose of improving the removal percentage. In addition, this is a procedure that follows a green approach since the reagents involved have low environmental impact, and the contribution to the remediation of natural resources is high.

Keywords: biomass, nanotechnology, science materials, wastewater treatment

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Authors: Usama Bin Zubair, Syed Azhar Ali

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Introduction: Depression is emerging as a major public health problem in all parts of the world. Developing countries have a unique socioeconomic structure that affects the lives of its inhabitants in several ways. Going abroad for employment is one of the common social problems which have been faced by young males in developing countries. This included both highly qualified individuals as well as the labor class. Objective: To determine the difference in the presence of depressive symptoms among pregnant women with husbands living abroad and those with husbands living with them in Azad Jammu and Kashmir. Methods: The sample population comprised of pregnant women reporting for an antenatal checkup at Amna hospital Rawalakot. Cases constituted the pregnant women with husbands living abroad while controls were the pregnant women with husbands living with them. Patient health questionnaire-9 (PHQ-9) was used to record the presence and severity of depressive symptoms. Age, gestation, parity, rural or urban origin, education, level of family income, daily contact hours on the telephone or what’s app, previous pregnancy loss or complications, number of years abroad and visits to home per year were associated with the presence of depressive symptoms. Findings: The mean age of the study participants was 29.73 ±5.395 years. Sixty-six had significant depression in the case group, while 14 had in the control group (p-value<0.001). Education and rural background had a significant difference between the case and the control group. Less number of visits per year of the husband was strongly linked with the presence of depressive symptoms among the cases. Conclusion: Pregnant women with husbands abroad were found more prone to develop depressive symptoms as compared to those with husbands living with them. Special attention should be paid to the women whose husband had a lesser number of visits to the country.

Keywords: depression, pregnancy, lack of support, war zone

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Authors: Mannar R. Maurya, Bhawna Uprety, Fernando Avecilla, Pedro Adão, J. Costa Pessoa

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The reaction of the tripodal tetradentate dibasic ligand 6,6'–(2–(pyridin–2–yl)ethylazanediyl)bis(methylene)bis(2,4–di–tert–butylphenol), H2L1 I, with [VIVO(acac)2] in CH3CN gives the VVO–complex, [VVO(acac)(L1)] 1. Crystallization of 1 in CH3CN at ~0 ºC, gives dark blue crystals of 1, while at room temperature it affords dark green crystals of [{VVO(L1)}2µ–O] 3. Upon prolonged treatment of 1 in MeOH [VVO(OMe)(MeOH)(L1)] 2 is obtained. All three complexes are analyzed by single–crystal X–ray diffraction, depicting distorted octahedral geometry around vanadium. In the reaction of H2L1 with VIVOSO4 partial hydrolysis of the tripodal ligand results in elimination of the pyridyl fragment of L1 and the formation of H[VVO2(L2)] 4, containing the ONO tridentate ligand 6,6'–azanediylbis(methylene)bis(2,4–di–tert–butylphenol), H2L2 II. Compound 4, which was not fully characterized, undergoes dimerization in acetone yielding the hydroxido–bridged [{VVO(L2)}2µ–(HO)2] 5, having distorted octahedral geometry around each vanadium. In contrast, from a solution of 4 in acetonitrile, the dinuclear compound [{VVO(L2)}2µ–O] 6 is obtained, with trigonal bipyramidal geometry around each vanadium. The methoxido complex 2 is successfully employed as a functional catechol–oxidase mimic in the oxidation of catechol to o–quinone under air. The process is confirmed to follow a Michaelis–Menten type kinetics with respect to catechol, the Vmax and KM values obtained being 7.66×10–6 M min -1 and 0.0557 M, respectively, and the turnover frequency is 0.0541 min–1. Complex 2 is also used as a catalyst precursor for the oxidative bromination of thymol in aqueous medium. The selectivity shows quite interesting trends, namely when not using excess of primary oxidizing agent, H2O2 the para mono–brominated product corresponds to ~93 % of the products and no dibromo derivative is formed.

Keywords: oxidovanadium (V) complexes, tripodal ligand, crystal structure, catechol oxidase mimetic activity

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Authors: Adya Uluwita, Fernando Pedrosa, Georgi Georgiev, Christian Bernard, Raoul Masterson

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CERN is an international organisation funded by 23 countries that provide the particle physics community with excellence in particle accelerators and other related facilities. Founded in 1954, CERN has a wide range of accelerators that allow groundbreaking science to be conducted. Accelerators bring particles to high levels of energy and make them collide with each other or with fixed targets, creating specific conditions that are of high interest to physicists. A chain of accelerators is used to ramp up the energy of particles and eventually inject them into the largest and most recent one: the Large Hadron Collider (LHC). Among this chain of machines is, for instance the Proton Synchrotron, which was started in 1959 and is still in operation. These machines, called "injectors”, keep evolving over time, as well as the related infrastructure. Massive decommissioning of obsolete cables started in 2015 at CERN in the frame of the so-called "injectors de-cabling project phase 1". Its goal was to replace aging cables and remove unused ones, freeing space for new cables necessary for upgrades and consolidation campaigns. To proceed with the de-cabling, a project co-ordination team was assembled. The start of this project led to the investigation of legacy cables throughout the organisation. The identification of cables stacked over half a century proved to be arduous. Phase 1 of the injectors de-cabling was implemented for 3 years with success after overcoming some difficulties. Phase 2, started 3 years later, focused on improving safety and structure with the introduction of a quality assurance procedure. This paper discusses the implementation of this quality assurance procedure throughout phase 2 of the project and the transition between the two phases. Over hundreds of kilometres of cable were removed in the injectors complex at CERN from 2015 to 2023.

Keywords: CERN, de-cabling, injectors, quality assurance procedure

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Authors: Barbara Pittau, Piergiorgio Palla, Antonio Mastino

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Communication is fundamental to health education. The proper use of medicinal products is a crucial aspect of the health of citizens that affects both safety and health care spending. Therefore, encouraging/promoting communication, concerning the importance of proper use of pharmaceuticals, has substantial implications in terms of individual health, health care, and health care system sustainability. In view of these considerations, in the context of two projects, one of which is still in progress, a relational database-backed web application named COLLABORAFARMACISOLA has been designed and developed as a tool to analyze and visualize how people approach the use of medicinal products, with the aim of improving and enhancing communication efficacy. The software application is being used to collect information (anonymously and voluntarily) from the citizens of Sardinia, an Italian region, regarding their knowledge, experiences, and opinions towards pharmaceuticals. This study that was conducted to date on thousand of interviewed people, has focused on different aspects such as: the treatment interruption and the "self-prescription” without medical consultation, the attention paid to reading the leaflets, the awareness of the economic value of the pharmaceuticals, the importance of avoiding the waste of medicinal products and the attitudes towards the use of generics. To this purpose, our software application provides a set of ad hoc parsing routines, to store information into the structure of a relational database and to process and visualize it through a set of interactive tools aimed to emphasize the findings and the insights obtained. The results of our preliminary analysis show the efficacy of the awareness plan and, at the same time, the criticality and the needs of the territory under examination. The ultimate goal of our study is to provide a contribution to the community by improving communication that can result in a benefit for public health in a context strictly connected to the reality of the territory.

Keywords: communication, pharmaceuticals, public health, relational database, tool, web application

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Authors: José Alberto García Fernández, Zhimin Du, Xinqiao Jin

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Nowadays, data center industry faces strong challenges for increasing the speed and data processing capacities while at the same time is trying to keep their devices a suitable working temperature without penalizing that capacity. Consequently, the cooling systems of this kind of facilities use a large amount of energy to dissipate the heat generated inside the servers, and developing new cooling techniques or perfecting those already existing would be a great advance in this type of industry. The installation of a temperature sensor matrix distributed in the structure of each server would provide the necessary information for collecting the required data for obtaining a temperature profile instantly inside them. However, the number of temperature probes required to obtain the temperature profiles with sufficient accuracy is very high and expensive. Therefore, other less intrusive techniques are employed where each point that characterizes the server temperature profile is obtained by solving differential equations through simulation methods, simplifying data collection techniques but increasing the time to obtain results. In order to reduce these calculation times, complicated and slow computational fluid dynamics simulations are replaced by simpler and faster finite element method simulations which solve the Burgers‘ equations by backward, forward and central discretization techniques after simplifying the energy and enthalpy conservation differential equations. The discretization methods employed for solving the first and second order derivatives of the obtained Burgers‘ equation after these simplifications are the key for obtaining results with greater or lesser accuracy regardless of the characteristic truncation error.

Keywords: Burgers' equations, CFD simulation, data center, discretization methods, FEM simulation, temperature profile

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Authors: Lize Tibiriçá, Ronnie Lee, Samantha Behbahani

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Fibromyalgia (FM) is a musculoskeletal disorder affecting men and women of different ages and cultures. The cause of this disorder is unknown; however, studies suggest an etiology that involves biological and psychosocial factors. Few studies have shown that a personality type such as neuroticism is associated with chronic pain conditions. Past research has explored whether patients with FM present with a specific personality trait. However, studies have used different methods (i.e. Minnesota Multiphasic Personality Inventory (MMPI), Sociotropy and Autonomy Scale (SAS) and Dysfunctional Attitude Scale (DAS), Tridimensional Personality Questionnaire or Temperament and Character Inventory (TCI), Karolinska scale of personality, Big Five Inventory or NEO Personality Inventory) to explore the connection between FM and a personality type. They have identified personality types that present similar characteristics but vary in the name (i.e. high harm avoidance and low novelty seeking, psychasthenia/muscular tension/somatic anxiety, neuroticism). Although Zuckerman-Kuhlman Personality Questionnaire and the Big Five Inventory differ in terms of content and structure, both of them identify neuroticism as the personality type of FM patients, and the former also identifies these patients as having a low sociability personality trait. Previous research also shows a trend of sociotropic personality style with FM patients that also suffer from Major Depressive Disorder. Participants in these studies were, for the most part, adult female and researchers have recognized that as a limitation and whether their findings can be generalized to men and younger patients with FM. Furthermore, most studies reviewed were conducted in Europe (i.e. Spain) and had a cross-sectional design. Future research should replicate past studies in different countries and consider conducting a longitudinal study. Although it is suspected that FM course is modulated by FM patients’ personality, it is not known whether individuals with similar personalities will develop FM. This review sought to explain the differences and similarities between the personality types identified. Limitations in the studies reviewed were addressed, and considerations for future research and treatment were discussed.

Keywords: chronic pain, fibromyalgia, neuroticism, personality type

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Authors: Yasir Arafat, Asma Shah, Hua Shao

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Background and Aims: Legume/cereal intercropping is used worldwide for enhancement in biomass and yield of cereal crops. However, because of intercropping, the belowground biological and chemical interactions and their effect on physiological parameters and yield of crops are limited. Methods: Wheat faba bean (WF) intercropping was designed to understand the underlying changes in the soil's chemical environment, soil microbial communities, and effect on growth and yield parameters. Experimental plots were established as having no root partition (NRP), semi-root partition (SRP), complete root partition (CRP), and their sole cropping (CK). Low molecular weight organic acids (LMWOAs) were determined by GC-MS, and high throughput sequencing of the 16S rRNA gene was carried out to screen microbial structure and composition in different root partitions of the WF intercropping system. Results: We show that intercropping induced a shift in the relative abundance of some genera of plant growth promoting rhizobacteria (PGPR) such as Allorhizobium, Neorhizobium, Pararhizobium, and Rhizobium species and resulted in better growth and yield performance of wheat. Moreover, as the plant's distance of wheat from faba beans decreased, the diversity of microbes increased, and a positive effect was observed on physiological traits and crop yield. Furthermore, an abundance and positive correlations of palmitic acid, arachidic acid, stearic acid, and 9-Octadecenoic with PGPR were recorded in the root zone of WF intercropping, which can play an important role in this facilitative mechanism of enhancing growth and yield of cereals. Conclusion: The two treatments clearly affected soil microbial and chemical composition, which can be reflected in growth and yield enhancement.

Keywords: intercropping, microbial community, LMWOAs, PGPR, soil chemical environment

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Authors: Samson Mil'shtein, Dhawal Asthana, Benjamin Sullivan

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The wide energy gap of GaN is the major parameter justifying the design and fabrication of high-power electronic components made of this material. However, the existence of a piezo-electrics in nature sheet charge at the AlGaN/GaN interface complicates the control of carrier injection into the intrinsic channel of GaN HEMTs (High Electron Mobility Transistors). As a result, most of the transistors created as R&D prototypes and all of the designs used for mass production are D-mode devices which introduce challenges in the design of integrated circuits. This research presents the design and modeling of an E-mode GaN HEMT with a very low turn-on voltage. The proposed device includes two critical elements allowing the transistor to achieve zero conductance across the channel when Vg = 0V. This is accomplished through the inclusion of an extremely thin, 2.5nm intrinsic Ga₀.₇₄Al₀.₂₆N spacer layer. The added spacer layer does not create piezoelectric strain but rather elastically follows the variations of the crystal structure of the adjacent GaN channel. The second important factor is the design of a gate metal with a high work function. The use of a metal gate with a work function (Ni in this research) greater than 5.3eV positioned on top of n-type doped (Nd=10¹⁷cm⁻³) Ga₀.₇₄Al₀.₂₆N creates the necessary built-in potential, which controls the injection of electrons into the intrinsic channel as the gate voltage is increased. The 5µm long transistor with a 0.18µm long gate and a channel width of 30µm operate at Vd=10V. At Vg =1V, the device reaches the maximum drain current of 0.6mA, which indicates a high current density. The presented device is operational at frequencies greater than 10GHz and exhibits a stable transconductance over the full range of operational gate voltages.

Keywords: compound semiconductors, device modeling, enhancement mode HEMT, gallium nitride

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Authors: Jawaher A. Alsultan, Allen Feldman

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With the rapid switch to remote learning due to the COVID-19 pandemic, science teachers were suddenly required to teach their classes online. This breakneck shift to eLearning raised the question of how teacher educators could support science teachers who wanted to use reform-based methods of instruction while using virtual technologies. In this retrospective self-study, we, two science teacher educators, examined our practice as we worked with science teachers to implement inquiry, discussion, and argumentation [IDA] through eLearning. Ten high school science teachers from a large school district in the southeastern US participated virtually in the COVID-19 Community of Practice [COVID-19 CoP]. The CoP met six times from the end of April through May 2020 via Zoom. Its structure was based on a model of action research called enhanced normal practice [ENP], which includes exchanging stories, trying out ideas, and systematic inquiry. Data sources included teacher educators' meeting notes and reflective conversations, audio recordings of the CoP meetings, teachers' products, and post-interviews of the teachers. Findings included a new understanding of the role of existing relationships, shared goals, and similarities in the participants' situations, which helped build trust in the CoP, and the effects of our paying attention to the science teachers’ needs led to a well-functioning CoP. In addition, we became aware of the gaps in our knowledge of how the teachers already used apps in their practice, which they then shared with all of us about how they could be used for online teaching using IDA. We also identified the need to pay attention to feelings about tensions between the teachers and us around the expectations for final products and the project's primary goals. We found that if we are to establish relationships between us as facilitators and teachers that are honest, fair, and kind, we must express those feelings within the collective, dialogical processes that can lead to learning by all members of the CoP, whether virtual or face-to-face.

Keywords: community of practice, facilitators, self-study, action research

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