Search results for: total and partial densities of states

Authors: A. Bentabet, A. Aydin, N. Fenineche

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In this work, we try to determine the best analytical approximation of differential cross sections, used generally in Monte Carlo simulation, to study the electron/positron slowing down in solid targets in the energy range up to 10 keV. Actually, our comparative study was carried out on the angular distribution of the scattering angle, the elastic total and the first transport cross sections which are the essential quantities used generally in the electron/positron transport study by using both stochastic and deterministic methods. Indeed, the obtained results using the relativistic partial wave expansion method and the backscattering coefficient experimental data are used as criteria to evaluate the used model.

Keywords: differential cross-section, backscattering coefficient, Rutherford cross-section, Vicanek and Urbassek theory

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Authors: Laura Angulo, Petra Salamon, Martin Banse, Frederic Storkamp

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Fisheries subsidies are focus on reduce management costs or deliver income benefits to fishers. In 2015, total fishery budgetary transfers in 31 OECD countries represented 35% of their total landing value. However, subsidies to fishing have adverse effects on trade and it has been claimed that they may contribute directly to overfishing. Therefore, this paper analyses to what extend fisheries subsidies may 1) influence capture production facing quotas and 2) affect price dynamics. The study uses the fish module in AGMEMOD (Agriculture Member States Modelling, details see Chantreuil et al. (2012)) which covers eight fish categories (cephalopods; crustaceans; demersal marine fish; pelagic marine fish; molluscs excl. cephalopods; other marine finfish species; freshwater and diadromous fish) for EU member states and other selected countries developed under the SUCCESS project. This model incorporates transfer payments directly linked to fisheries operational costs. As aquaculture and wild fishery are not included within the WTO Agreement on Agriculture, data on fisheries subsidies is obtained from the OECD Fisheries Support Estimates (FSE) database, which provides statistics on budgetary transfers to the fisheries sector. Since support has been moving from budgetary transfers to General Service Support Estimate the last years, subsidies in capture production may not present substantial effects. Nevertheless, they would still show the impact across countries and fish categories within the European Union.

Keywords: AGMEMOD, budgetary transfers, EU Member States, fish model, fisheries support estimate

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Authors: Chunyang Miao, Bingxin Li, Shanglong Ning, Christopher J. B. Ford

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While it is challenging to fabricate electronic devices close to atomic dimensions in conventional top-down lithography, molecular electronics is promising to help maintain the exponential increase in component densities via using molecular building blocks to fabricate electronic components from the bottom up. It offers smaller, faster, and more energy-efficient electronic and photonic systems. A self-assembled monolayer (SAM) of molecules is a layer of molecules that self-assembles on a substrate. They are mechanically flexible, optically transparent, low-cost, and easy to fabricate. A large-area multi-layer structure has been designed and investigated by the team, where a SAM of designed molecules is sandwiched between graphene and gold electrodes. Each molecule can act as a quantum dot, with all molecules conducting in parallel. When a source-drain bias is applied, significant current flows only if a molecular orbital (HOMO or LUMO) lies within the source-drain energy window. If electrons tunnel sequentially on and off the molecule, the charge on the molecule is well-defined and the finite charging energy causes Coulomb blockade of transport until the molecular orbital comes within the energy window. This produces ‘Coulomb diamonds’ in the conductance vs source-drain and gate voltages. For different tunnel barriers at either end of the molecule, it is harder for electrons to tunnel out of the dot than in (or vice versa), resulting in the accumulation of two or more charges and a ‘Coulomb staircase’ in the current vs voltage. This nanostructure exhibits highly reproducible Coulomb-staircase patterns, together with additional oscillations, which are believed to be attributed to molecular vibrations. Molecules are more isolated than semiconductor dots, and so have a discrete phonon spectrum. When tunnelling into or out of a molecule, one or more vibronic states can be excited in the molecule, providing additional transport channels and resulting in additional peaks in the conductance. For useful molecular electronic devices, achieving the optimum orbital alignment of molecules to the Fermi energy in the leads is essential. To explore it, a drop of ionic liquid is employed on top of the graphene to establish an electric field at the graphene, which screens poorly, gating the molecules underneath. Results for various molecules with different alignments of Fermi energy to HOMO have shown highly reproducible Coulomb-diamond patterns, which agree reasonably with DFT calculations. In summary, this large-area SAM molecular junction is a promising candidate for future electronic circuits. (1) The small size (1-10nm) of the molecules and good flexibility of the SAM lead to the scalable assembly of ultra-high densities of functional molecules, with advantages in cost, efficiency, and power dissipation. (2) The contacting technique using graphene enables mass fabrication. (3) Its well-observed Coulomb blockade behaviour, narrow molecular resonances, and well-resolved vibronic states offer good tuneability for various functionalities, such as switches, thermoelectric generators, and memristors, etc.

Keywords: molecular electronics, Coulomb blokade, electron-phonon coupling, self-assembled monolayer

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Authors: Xuewen Yu, Danhui Dan

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The identification of impact load and some hard-to-obtain system parameters is crucial for the activities of analysis, validation, and evaluation in the engineering field. This paper proposes a method that utilizes neural networks based on 1D-CNN to identify the impact load and partial system parameters from measured responses. To this end, forward computations are conducted to provide datasets consisting of the triples (parameter θ, input u, output y). Then neural networks are trained to learn the mapping from input to output, fu|{θ} : y → u, as well as from input and output to parameter, fθ : (u, y) → θ. Afterward, feeding the trained neural networks the measured output response, the input impact load and system parameter can be calculated, respectively. The method is tested on two simulated examples and shows sound accuracy in estimating the impact load (waveform and location) and system parameters.

Keywords: convolutional neural network, impact load identification, system parameter identification, inverse problem

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Authors: Nadia Fatima Zahra Malki

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The aim of the study is to show the role of total Quality Management on firm performance, research relied on the views of a sample managers working in the Marinel pharmaceutical company. The research aims to achieve many objectives, including increasing awareness of the concepts of Total Quality Management on Firm Performance, especially in the manufacturing firm, providing a future vision of the possibility of success, and the actual application of the Principles of Total Quality Management in the manufacturing company. The research adopted a default model was built after a review and analysis of the literature review in the context of one hypothesis's main points at the origin of a group of sub-hypotheses. The research presented a set of conclusions, and the most important of these conclusions was that there is a relationship between the Principles of TQM and Firm Performance.

Keywords: total quality management, competitive advantage, companies, objectives

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Authors: A. M. Jungudo, M. A. Lasan

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Affordable housing has long been one of the basic necessities of life to man. The ever rising prices of building materials are one of the major causes of housing shortage in many developing countries. Breaching the gap of housing needs in developing countries like Nigeria is an awaiting task longing for attention. This is due to lack of research in the development of local materials that will suit the troubled economies of these countries. The use of earth material to meet the housing needs is a sustainable option and its material is freely available universally. However, people are doubtful of using the earth material due to its modest outlook and uncertain durability. This research aims at enhancing the durability of Compressed Earth Bricks (CEBs) using stone dust as a stabilizer. The result indicates that partial replacement of lateritic soil with stone dust at 30% improves its compressive strength along with abrasive resistance.

Keywords: earth construction, durability, stone dust, sustainable

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Authors: Lina Wu

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The excessive discharge of nitrogen in sewage greatly intensifies the eutrophication of water bodies and poses a threat to water quality. Nitrogen pollution control has become a global concern. Currently, the problem of water pollution in China is still not optimistic. As a typical high ammonia nitrogen organic wastewater, landfill leachate is more difficult to treat than domestic sewage because of its complex water quality, high toxicity, and high concentration.Many studies have shown that the autotrophic anammox bacteria in nature can combine nitrous and ammonia nitrogen without carbon source through functional genes to achieve total nitrogen removal, which is very suitable for the removal of nitrogen from leachate. In addition, the process also saves a lot of aeration energy consumption than the traditional nitrogen removal process. Therefore, anammox plays an important role in nitrogen conversion and energy saving. The process composed of short-range nitrification and denitrification coupled an ammo ensures the removal of total nitrogen and improves the removal efficiency, meeting the needs of the society for an ecologically friendly and cost-effective nutrient removal treatment technology. Continuous flow process for treating late leachate [an up-flow anaerobic sludge blanket reactor (UASB), anoxic/oxic (A/O)–anaerobic ammonia oxidation reactor (ANAOR or anammox reactor)] has been developed to achieve autotrophic deep nitrogen removal. In this process, the optimal process parameters such as hydraulic retention time and nitrification flow rate have been obtained, and have been applied to the rapid start-up and stable operation of the process system and high removal efficiency. Besides, finding the characteristics of microbial community during the start-up of anammox process system and analyzing its microbial ecological mechanism provide a basis for the enrichment of anammox microbial community under high environmental stress. One research developed partial nitrification-Anammox (PN/A) using an internal circulation (IC) system and a biological aerated filter (BAF) biofilm reactor (IBBR), where the amount of water treated is closer to that of landfill leachate. However, new high-throughput sequencing technology is still required to be utilized to analyze the changes of microbial diversity of this system, related functional genera and functional genes under optimal conditions, providing theoretical and further practical basis for the engineering application of novel anammox system in biogas slurry treatment and resource utilization.

Keywords: nutrient removal and recovery, leachate, anammox, partial nitrification

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Authors: Saghar Heidari

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In this paper, we study the valuation problem of European continuous-installment options under Markov-modulated models with a partial differential equation approach. Due to the opportunity for continuing or stopping to pay installments, the valuation problem under regime-switching models can be formulated as coupled partial differential equations (CPDE) with free boundary features. To value the installment options, we express the truncated CPDE as a linear complementarity problem (LCP), then a finite element method is proposed to solve the resulted variational inequality. Under some appropriate assumptions, we establish the stability of the method and illustrate some numerical results to examine the rate of convergence and accuracy of the proposed method for the pricing problem under the regime-switching model.

Keywords: continuous-installment option, European option, regime-switching model, finite element method

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Authors: Suwarno, M. Helmi Prakoso

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Mineral oil is commonly used for high voltage transformer insulation. The insulation quality of mineral oil is affecting the operation process of high voltage transformer. There are many contaminations which could decrease the insulation quality of mineral oil. One of them is water. This research talks about the effect of water content on dielectric properties, physic properties, and partial discharge pattern on mineral oil. Samples were varied with 10 varieties of water content value. And then all samples were tested to measure the dielectric properties, physic properties, and partial discharge pattern. The result of this research showed that an increment of water content value would decrease the insulation quality of mineral oil.

Keywords: dielectric properties, high voltage transformer, mineral oil, water content

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Authors: Aina Barcelona, Carolyn Oldham, Jordi Colomer, Teresa Serra

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The loss of seagrass meadows worldwide is being tackled by formulating coastal restoration strategies. Seagrass loss results in a network of vegetated patches which are barely interconnected, and consequently, the ecological services they provide may be highly compromised. Hence, there is a need to optimize coastal management efforts in order to implement successful restoration strategies, not only through modifying the architecture of the canopies but also by gathering together information on the hydrodynamic conditions of the seabeds. To obtain information on the hydrodynamics within the patches of vegetation, this study deals with the scale analysis of the minimum lengths of patch management strategies that can be effectively used on. To this aim, a set of laboratory experiments were conducted in a laboratory flume where the plant densities, patch lengths, and hydrodynamic conditions were varied to discern the vegetated patch lengths that can provide optimal ecosystem services for canopy development. Two possible patch behaviours based on the turbulent kinetic energy (TKE) production were determined: one where plants do not interact with the flow and the other where plants interact with waves and produce TKE. Furthermore, this study determines the minimum patch lengths that can provide successful management restoration. A canopy will produce TKE, depending on its density, the length of the vegetated patch, and the wave velocities. Therefore, a vegetated patch will produce plant-wave interaction under high wave velocities when it presents large lengths and high canopy densities.

Keywords: seagrass, minimum patch size, turbulent kinetic energy, oscillatory flow

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Authors: B. Oral, C. Bal, M. S. Kar, A. Akgürbüz

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Loss of maxillary central incisors occurs in many patients, and the treatment of young adults with this problem is a challenge for both prosthodontists and orthodontists. Common treatment alternatives are distalization of adjacent teeth and fabrication of a conventional 3-unit fixed partial denture, a single implant supported crown restoration or a resin-bonded fixed partial denture. This case report describes the indication of a resin-bonded fixed partial denture, preparation of the abutment teeth and the prosthetic procedures. The technique described here represents a conservative, esthetically pleasing and rapid solution for the missing maxillary central incisor when implant placement and/or guided bone regeneration techniques are not feasible because of financial, social or time restrictions. In this case a 16 year-old female patient who lost her maxillary left central incisor six years ago in a bicycle accident applied to our clinic with a major complaint of her unaesthetic appearance associated with the loss of her maxillary left central incisor. Although there was an indication for orthodontic treatment because of the limited space at the traumatized area, the patient did not accept to receive any orthodontic procedure. That is why an implant supported restoration could not be an option for the narrow area. Therefore maryland bridge as a minimal invasive dental therapy was preferred as a retention appliance so the patient's aesthetic appearance was restored.

Keywords: Maryland bridge, single tooth restoration, aesthetics, maxillary central incisors

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Authors: Aleksandrs Kovalcuks, Mara Duma

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Egg yolk oil is a concentrated source of egg bioactive compounds, such as fat-soluble vitamins, phospholipids, cholesterol, carotenoids and others. To extract lipids and other fat-soluble nutrients from liquid egg yolk, a two-step extraction process involving polar (ethanol) and non-polar (hexane) solvents were used. This extraction technique was based on egg yolk bioactive compounds polarities, where non-polar compound was extracted into non-polar hexane, but polar in to polar alcohol/water phase. But many egg yolk bioactive compounds are not strongly polar or non-polar. Egg yolk phospholipids, cholesterol and pigments are amphipatic (have both polar and non-polar regions) and their behavior in ethanol/hexane solvent system is not clear. The aim of this study was to clarify the behavior of phospholipids, cholesterol and carotenoids during extraction of egg yolk oil with ethanol and hexane and determine the loss of these compounds in egg yolk oil. Egg yolks and egg yolk oil were analyzed for phospholipids (phosphatidylcholine (PC) and phosphatidylethanolamine (PE)), cholesterol and carotenoids (lutein, zeaxanthin, canthaxanthin and β-carotene) content using GC-FID and HPLC methods. PC and PE are polar lipids and were extracted into polar ethanol phase. Concentration of PC in ethanol was 97.89% and PE 99.81% from total egg yolk phospholipids. Due to cholesterol’s partial extraction into ethanol, cholesterol content in egg yolk oil was reduced in comparison to its total content presented in egg yolk lipids. The highest amount of lutein and zeaxanthin was concentrated in ethanol extract. The opposite situation was observed with canthaxanthin and β-carotene, which became the main pigments of egg yolk oil.

Keywords: cholesterol, egg yolk oil, lutein, phospholipids, solvent extraction

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Authors: Malki Nadia Fatima Zahra, Kellal Cheimaa, Brahimi Houria

Abstract:

Aim of the study is to show the role of total Quality Management on firm performance; the research relied on the views of sample managers working in the Marinel pharmaceutical company. The research aims to achieve many objectives, including increasing awareness of the concepts of Total Quality Management on Firm Performance, especially in the manufacturing firm, providing a future vision of the possibility of success, and the actual application of the Principles of Total Quality Management in the manufacturing company. The research adopted a default model was built after a review and analysis of the literature review in the context of one hypothesis main points at the origin of a group of sub-hypotheses. The research presented a set of conclusions, and the most important of these conclusions was there is a relationship between the Principles of TQM and Firm Performance.

Keywords: total quality management, TQM dimension, firm performance, strategies

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Authors: Miang Hong Ngerng, Noor Diyana Jasme, May Jin Theong

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Volatile market environment is inevitable. Fund managers are struggling to choose the right strategy to survive and overcome uncertainties and adverse market movement. Therefore, finding certainty in the mist of uncertainty future is one of the key performance objectives for fund managers. Current available theoretical results are not practical due to strong reliance on the investment assumption made. This paper is to identify the component that can be forecasted in Ex-ante setting which is the realistic situation facing a fund manager in the actual execution of asset allocation in portfolio management. Partial lease square method was used to generate an index with 10 years accounting data from 191 companies listed in KLSE. The result shows that the index reflects the inner nature of the business and up to 30% of the stock return can be explained by the index.

Keywords: active portfolio management, asset allocation ex-ante investment, asset class, partial lease square

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Authors: Scott Kelting, Lucas Nozick

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The perpetually growing population and economy within the United States necessitates building construction of all types. Increased building generates environmental concerns, and rightfully so. This industry accounts for approximately 4% of the total GDP in the United States while creating around two-thirds of the material waste annually. The green building movement is certainly gaining popularity in both application and recognition through entities such as the United States Green Building Council (USGBC) and their LEED program; however, builders are also producing their ideas. Alternative housing solutions that include pre-fabricated building components and shipping container homes are making great strides in the residential construction industry, and will certainly play an important role in the future. This paper will compare the cost and schedule of modular, panelized and shipping container homes to traditional stick frame home construction in the Greater Los Angeles Metropolitan Area and recommend the best application for each option.

Keywords: cost, prefabricated, schedule, shipping container, stick framed

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Authors: Patricia O. Carvalho, Marcia C. F. Messias, Salvador Sanchez Vinces, Caroline F. A. Gatinoni, Vitor P. Iordanu, Carlos A. R. Martinez

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Lipidomics methods are widely used in the identification and validation of disease-specific biomarkers and therapy response evaluation. The present study aimed to identify a panel of potential lipid biomarkers to evaluate response to neoadjuvant chemoradiotherapy in rectal adenocarcinoma (RAC). Liquid chromatography–mass spectrometry (LC-MS)-based untargeted lipidomic was used to profile human serum samples from patients with clinical stage T2 or T3 resectable RAC, after and before chemoradiotherapy treatment. A total of 28 blood plasma samples were collected from 14 patients with RAC who recruited at the São Francisco University Hospital (HUSF/USF). The study was approved by the ethics committee (CAAE 14958819.8.0000.5514). Univariate and multivariate statistical analyses were applied to explore dysregulated metabolic pathways using untargeted lipidic profiling and data mining approaches. A total of 36 statistically significant altered lipids were identified and the subsequent partial least-squares discriminant analysis model was both cross validated (R2, Q2) and permutated. Lisophosphatidyl-choline (LPC) plasmalogens containing palmitoleic and oleic acids, with high variable importance in projection score, showed a tendency to be lower after completion of chemoradiotherapy. Chemoradiotherapy seems to change plasmanyl-phospholipids levels, indicating that these lipids play an important role in the RAC pathogenesis.

Keywords: lipidomics, neoadjuvant chemoradiotherapy, plasmalogens, rectal adenocarcinoma

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Authors: Mohammad Shams Esfand Abadi, Mohammad Ranjbar, Reza Ebrahimpour

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This work presents the distributed processing solution problem in a diffusion network based on the adapt then combine (ATC) and combine then adapt (CTA)selective partial update normalized least mean squares (SPU-NLMS) algorithms. Also, we extend this approach to dynamic selection affine projection algorithm (DS-APA) and ATC-DS-APA and CTA-DS-APA are established. The purpose of ATC-SPU-NLMS and CTA-SPU-NLMS algorithm is to reduce the computational complexity by updating the selected blocks of weight coefficients at every iteration. In CTA-DS-APA and ATC-DS-APA, the number of the input vectors is selected dynamically. Diffusion cooperation strategies have been shown to provide good performance based on these algorithms. The good performance of introduced algorithm is illustrated with various experimental results.

Keywords: selective partial update, affine projection, dynamic selection, diffusion, adaptive distributed networks

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Authors: C. F. Glover, J. Marinaccio, A. Barnes, I. Mabbett, G. Williams

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The aim of the current study is to optimise formulations, in terms of charging efficiency, of a printed Ni(OH)2 precursor coating of a battery anode. Through the assessment of the current densities during charging, the efficiency of a range of formulations are compared. The Scanning vibrating electrode technique (SVET) is used extensively in the field of corrosion to measure area-averaged current densities of freely-corroding metal surfaces when fully immersed in electrolyte. Here, a Ni(OH)2 electrode is immersed in potassium hydroxide (30% w/v solution) electrolyte and charged using a range of applied currents. Samples are prepared whereby multiple coatings are applied to one substrate, separated by a non-conducting barrier, and charged using a constant current. With a known applied external current, electrode efficiencies can be calculated based on the current density outputs measured using SVET. When fully charged, a green Ni(OH)2 is oxidised to a black NiOOH surface. Distinct regions displaying high current density, and hence a faster oxidising reaction rate, are located using the SVET. This is confirmed by a darkening of the region upon transition to NiOOH. SVET is a highly effective tool for assessing homogeneity of electrodes during charge/discharge. This could prove particularly useful for electrodes where there are no visible surface appearance changes. Furthermore, a scanning Kelvin probe technique, traditionally used to assess underfilm delamination of organic coatings for the protection of metallic surfaces, is employed to study the change in phase of oxides, pre and post charging.

Keywords: battery, electrode, nickel hydroxide, SVET, printed

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Authors: Kamran Dastafkan, Chuan Zhao

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Improving surface chemistry is a promising approach in addition to the rational alteration in the catalyst composition to advance water electrolysis. Here, we demonstrate an evident enhancement of oxygen evolution on an iron-nickel vanadate catalyst synthesized by a facile successive ionic adsorption and reaction method. The vanadate-modified catalyst demonstrates a highly efficient oxygen evolution in 1 M KOH by requiring low overpotentials of 274 and 310 mV for delivering large current densities of 100 and 400 mA cm⁻², respectively where vigorous gas bubble evolution occurs. Vanadate modification augments the OER activity from three aspects. (i) Both the electrochemical surface area (47.1 cm²) and intrinsic activity (318 mV to deliver 10 mA cm⁻² per unit ECSA) of the catalytic sites are improved. (ii) The amorphous and roughened nanoparticle-comprised catalyst film exhibits a high surface wettability and a low-gas bubble-adhesion, which is beneficial for the accelerated mass transport and gas bubble dissipation at large current densities. The gas bubble dissipation behavior is studied by operando dynamic specific resistance measurements where a significant change in the variation of the interfacial resistance during the OER is detected for the vanadate-modified catalyst. (iii) The introduced vanadate poly-oxo-anions with high charge density have electronic interplay with Fe and Ni catalytic centers. Raman study reveals the structural evolution of β-NiOOH and γ-FeOOH phases during the OER through the vanadate-active site synergistic interactions. Achievement of a high catalytic turnover of 0.12 s⁻¹ put the developed FeNi vanadate among the best recent catalysts for water oxidation.

Keywords: gas bubble dissipation, iron-nickel vanadate, low-gas bubble-adhesion catalyst, oxygen evolution reaction

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Authors: Muhammad Javed Bhatti, Tariq Ali, Muazz Ali

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Due to growing environmental awareness in Pakistan, the researchers are increasingly turning to assess and analyze properties of industrial waste and finding solutions on using industrial waste as secondary material. Due to industrialization, enormous by-products are produced and to utilize these by-products is the main challenge faced in Pakistan. Induction furnace slag is one of the industrial by-products from the iron and steel making industries. This paper highlights the true utilization of induction furnace slag as partial replacement of fine aggregate. For the experimental investigation, mixes were prepared with fine aggregate replacement using 0 percent, 5 percent, 10 percent, 15 percent, 20 percent, 25 percent, 30 percent, 35 percent and 40 percent induction furnace slag to evaluate the workability, compaction factor, compressive strength, flexural strength, modulus of elasticity.

Keywords: compressive strength, deflection, induction furnace slag, workability

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Authors: M. Abd El Hamid Ezzat

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Two field trials were conducted to study the effect of plant densities i.e., 190, 222, 266, 330 and 440 10³ plants ha⁻¹ on morphological characters, physiological and yield attributes of two faba bean types viz. determinate (FLIP-87 -117 strain) and indeterminate (c.v. Giza-461). The results showed that the indeterminate plants significantly surpassed the determinate plants in plant height at 75 and 90 days from sowing, number of leaves at all growth stages and dry matter accumulation at 45 and 90 days from sowing. Determinate plants possessed greater number of side branches than that of the indeterminate plants, but it was only significant at 90 days from sowing. Greater number of flowers were produced by the indeterminate plants than that of the determinate plants at 75 and 90 days from sowing, and although shedding was obvious in both types, it was greater in the determinate plants as compared with the indeterminate one at 90 days from sowing. Increasing plant density resulted in reductions in number of leaves, branches flowers and dry matter accumulation per plant of both faba bean types. However, plant height criteria took a reversible magnitude. Moreover, under all rates of plant densities the indeterminate type plants surpassed the determinate plants in all growth characters studied except for number of branches per plant at 90 days from sowing. The indeterminate plant leaves significantly contained greater concentrations of photosynthetic pigments i.e., chl. a, b and carotenoids than those found in the determinate plant leaves. Also, the data showed significant reduction in photosynthetic pigments concentration as planting density increases. Light extinction coefficient (K) values reached their maximum level at 60 days from sowing, then it declined sharply at 75 days from sowing. The data showed that the illumination inside the determinate faba bean canopies was better than the indeterminate plants. (K) values tended to increase as planting density increases, meanwhile, significant interactions were reported between faba bean type as planting density on (K) at all growth stages. Both of determinate and indeterminate faba bean plant leaves reached their maximum expansion at 75 days from sowing reflecting the highest LAI values, then their declined in the subsequent growth stage. The indeterminate faba bean plants significantly surpassed the determinate plants in LAI up to 75 days from sowing. Growth analysis showed that NAR, RGR and CGR reached their maximum rates at (60-75 days growth stage). Faba bean types did not differ significantly in NAR at the early growth stage. The indeterminate plants were able to grow faster with significant CGR values than the determinate plants. The indeterminate faba bean plants surpassed the determinate ones in number of seeds/pod and per plant, 100-seed weight, seed yield per plant and per hectare at all rates of plant density. Seed yield increased with increasing plant densities of both types. The highest seed yield was attained for both types 440 103 plants ha⁻¹.

Keywords: determinate, indeterminate faba bean, Physiological attributes, yield attributes

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Authors: A. Albar, U. Schwingenschlogel

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Device applications of transparent conducting oxides require a thorough understanding of the physical and chemical properties of the involved interfaces. We use ab-initio calculations within density functional theory to investigate the electronic states at the SnO/SnO2 hetero-interface. Tin dioxide and monoxide are transparent materials with high n-type and p-type mobilities, respectively. This work aims at exploring the modifications of the electronic states, in particular the charge transfer, in the vicinity of the hetero-interface. The (110) interface is modeled by a super-cell approach in order to minimize the mismatch between the lattice parameters of the two compounds. We discuss the electronic density of states as a function of the distance to the interface.

Keywords: density of states, ab-initio calculations, interface states, charge transfer

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Authors: Erdem Meriç

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Measuring total temperature of air flow accurately is a very important requirement in the development phases of many industrial products, including gas turbines and rockets. Thermocouples are very practical devices to measure temperature in such cases, but in high speed and high temperature flows, the temperature of thermocouple junction may deviate considerably from real flow total temperature due to the effects of heat transfer mechanisms of convection, conduction, and radiation. To avoid errors in total temperature measurement, special probe designs which are experimentally characterized are used. In this study, a validation case which is an experimental characterization of a specific class of total temperature probes is selected from the literature to develop a numerical conjugate heat transfer analysis methodology to study the total temperature probe flow field and solid temperature distribution. Validated conjugate heat transfer methodology is used to investigate flow structures inside and around the probe and effects of probe design parameters like the ratio between inlet and outlet hole areas and prob tip geometry on measurement accuracy. Lastly, a thermal model is constructed to account for errors in total temperature measurement for a specific class of probes in different operating conditions. Outcomes of this work can guide experimentalists to design a very accurate total temperature probe and quantify the possible error for their specific case.

Keywords: conjugate heat transfer, recovery factor, thermocouples, total temperature probes

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Authors: Saurabh Basu, Sudin Ganguly

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Conductance in graphene nanoribbons (GNR) in presence of magnetic (for example, Iron) and non-magnetic (for example, Gold) adatoms are explored theoretically within a Kane-Mele model for their possible spintronic applications and topologically non-trivial properties. In our work, we have considered the magnetic adatoms to induce a Rashba spin-orbit coupling (RSOC) and an exchange bias field, while the non-magnetic ones induce an RSOC and an intrinsic spin-orbit (SO) coupling. Even though RSOC is present in both, they, however, represent very different physical situations, where the magnetic adatoms do not preserve the time reversal symmetry, while the non-magnetic case does. This has important implications on the topological properties. For example, the non-magnetic adatoms, for moderately strong values of SO, the GNR denotes a quantum spin Hall insulator as evident from a 2e²/h plateau in the longitudinal conductance and presence of distinct conducting edge states with an insulating bulk. Since the edge states are protected by time reversal symmetry, the magnetic adatoms in GNR yield trivial insulators and do not possess any non-trivial topological property. However, they have greater utility than the non-magnetic adatoms from the point of view of spintronic applications. Owing to the broken spatial symmetry induced by the presence of adatoms of either type, all the x, y and z components of the spin-polarized conductance become non-zero (only the y-component survives in pristine Graphene owing to a mirror symmetry present there) and hence become suitable for spintronic applications. However, the values of the spin polarized conductances are at least two orders of magnitude larger in the case of magnetic adatoms than their non-magnetic counterpart, thereby ensuring more efficient spintronic applications. Further the applications are tunable by altering the adatom densities.

Keywords: magnetic and non-magnetic adatoms, quantum spin hall phase, spintronic applications, spin polarized conductance, time reversal symmetry

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Authors: Mousa Keshavarz, Abdul-Reza Dabbagh, Maryam Soyuf Jahromi

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The diversity of mangrove macrobenthos assemblages at mudflat and mangrove ecosystems of Port Khamir, Iran were investigated for one year. During this period, we measured physicochemical properties of water temperature, salinity, pH, DO and the density and distribution of the macrobenthos. We sampled a total of 9 transects, at three different topographic levels along the intertidal zone at three stations. Assemblages at class level were compared. The five most diverse and abundant classes were Foraminifers (54%), Gastropods (23%), Polychaetes (10%), Bivalves (8%) & Crustaceans (5%), respectively. Overall densities were 1869 ± 424 ind/m2 (26%) in spring, 2544 ± 383 ind/m2(36%) in summer, 1482 ± 323 ind/m2 (21%) in autumn and 1207 ± 80 ind/m2 (17%) in winter. Along the intertidal zone, the overall relative density of individuals at high, intermediate, and low topographic levels was 40, 30, and 30% respectively. Biodiversity indices were used to compare different classes: Gastropoda (Shannon index: 0.33) and Foraminifera (Simpson index: 0.28) calculated the highest scores. It was also calculated other bio-indices. With the exception of bivalves, filter feeders were associated with coarser sediments at higher intertidal levels, while deposit feeders were associated with finer sediments at lower levels. Salinity was the most important factor acting on community structure, while DO and pH had little influence.

Keywords: macrobenthos, biodiversity, mangrove forest, Khamir Port

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Authors: Sana Mohammad Jafar

Abstract:

Salmonella is one of the major causes of foodborne diseases throughout the world. Shrimp are an important commodity in world fishery trade. The microbiological quality of shrimp must be evaluated for assurance of shrimp. The aim of this study was to evaluate the microbiological quality and to determine the prevalence of Salmonella in shrimp sold in Khuzestan province. In this study, a total of 245 samples of shrimp sold in Khuzestan province were tested for Salmonella prevalence and total microbial population. The mean aerobic bacterial count in 50.2% of samples was 2200, in 29.8% of samples was 13,600, in 20% of samples was 36,700, and the mean aerobic bacterial count in the total samples was 20,000. (20,000 cfu/cc). Of the total samples, 33 samples were positive for Salmonella and the prevalence of Salmonella was determined 13.4%. These results indicate the possibility that shrimp contribute to foodborne infections. The improvement of shrimp quality is an important issue, and shrimp before consuming should be washed with water containing chlorine, with the aim of increasing safety. In addition, it should be avoided to eat shrimp as raw or not cooked properly.

Keywords: determination, total microbial, Salmonella, shrimp

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Authors: Davood Yazdani Cherati, Hussein Hashemi Senejani

Abstract:

In this paper, a convenient analytical solution for a system of coupled differential equations, derived from thermo-hydro-mechanical analysis of three-phase porous media such as unsaturated soils is developed. This kind of analysis can be used in various fields such as geothermal energy systems and seepage of leachate from buried municipal and domestic waste in geomaterials. Initially, a system of coupled differential equations, including energy, mass, and momentum conservation equations is considered, and an analytical method called AGM is employed to solve the problem. The method is straightforward and comprehensible and can be used to solve various nonlinear partial differential equations (PDEs). Results indicate the accuracy of the applied method for solving nonlinear partial differential equations.

Keywords: AGM, analytical solution, porous media, thermo-hydro-mechanical, unsaturated soils

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Authors: Benbellil-Tafoughalt Saida, Tababouchet Meriem

Abstract:

Sexual selection is the most supported explanation for genital extravagance occurring in animals. In promiscuous species, population density, as well as climate conditions, may act on the sperm competition intensity, one of the most important mechanism of post-copulatory sexual selection. The present study is empirical testing of sexual selection's potential role on genitalia variation in the simultanuously hermaphroditic land snail Helixaperta (Pulmonata, Stylommatophora). The purpose was to detect the patterns as well as the origin of the distal genitalia variability and especially to test the potential effect of sexual selection. The study was performed on four populations, H. aperta, different in habitat humidity regimes and presenting variable densities, which were mostly low. The organs of interest were those involved in spermatophore production, reception, and manipulation. We examined whether the evolution of those organs is connected to sperm competition intensity which is traduced by both population density and microclimate humidity. We also tested the hypothesis that those organs evolve in response to shell size. The results revealed remarkable differences in both snails’ size and organs lengths between populations. In most cases, the length of genitalia correlated positively to snails’ body size. Interestingly, snails from the more humid microclimate presented the highest mean weight and shell dimensions comparing to those from the less humid microclimate. However, we failed to establish any relation between snail densities and any of the measured genitalia traits.

Keywords: fertilization pouch, helix aperta, land snails, reproduction, sperm storage, spermatheca

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Authors: Sara Camino, Fernando Vega, Mercedes Cano, Benito Navarrete, José A. Camino

Abstract:

Carbon capture and storage (CCS) technologies should play a relevant role towards low-carbon systems in the European Union by 2030. Partial oxy-combustion emerges as a promising CCS approach to mitigate anthropogenic CO₂ emissions. Its advantages respect to other CCS technologies rely on the production of a higher CO₂ concentrated flue gas than these provided by conventional air-firing processes. The presence of more CO₂ in the flue gas increases the driving force in the separation process and hence it might lead to further reductions of the energy requirements of the overall CO₂ capture process. A higher CO₂ concentrated flue gas should enhance the CO₂ capture by chemical absorption in solvent kinetic and CO₂ cyclic capacity. They have impact on the performance of the overall CO₂ absorption process by reducing the solvent flow-rate required for a specific CO₂ removal efficiency. Lower solvent flow-rates decreases the reboiler duty during the regeneration stage and also reduces the equipment size and pumping costs. Moreover, R&D activities in this field are focused on novel solvents and blends that provide lower CO₂ absorption enthalpies and therefore lower energy penalties associated to the solvent regeneration. In this respect, sterically hindered amines are considered potential solvents for CO₂ capture. They provide a low energy requirement during the regeneration process due to its molecular structure. However, its absorption kinetics are slow and they must be promoted by blending with faster solvents such as monoethanolamine (MEA) and piperazine (PZ). In this work, the kinetic behavior of two sterically hindered amines were studied under partial oxy-combustion conditions and compared with MEA. A lab-scale semi-batch reactor was used. The CO₂ composition of the synthetic flue gas varied from 15%v/v – conventional coal combustion – to 60%v/v – maximum CO₂ concentration allowable for an optimal partial oxy-combustion operation. Firstly, 2-amino-2-methyl-1-propanol (AMP) showed a hybrid behavior with fast kinetics and a low enthalpy of CO₂ absorption. The second solvent was Isophrondiamine (IF), which has a steric hindrance in one of the amino groups. Its free amino group increases its cyclic capacity. In general, the presence of higher CO₂ concentration in the flue gas accelerated the CO₂ absorption phenomena, producing higher CO₂ absorption rates. In addition, the evolution of the CO2 loading also exhibited higher values in the experiments using higher CO₂ concentrated flue gas. The steric hindrance causes a hybrid behavior in this solvent, between both fast and slow kinetic solvents. The kinetics rates observed in all the experiments carried out using AMP were higher than MEA, but lower than the IF. The kinetic enhancement experienced by AMP at a high CO2 concentration is slightly over 60%, instead of 70% – 80% for IF. AMP also improved its CO₂ absorption capacity by 24.7%, from 15%v/v to 60%v/v, almost double the improvements achieved by MEA. In IF experiments, the CO₂ loading increased around 10% from 15%v/v to 60%v/v CO₂ and it changed from 1.10 to 1.34 mole CO₂ per mole solvent, more than 20% of increase. This hybrid kinetic behavior makes AMP and IF promising solvents for partial oxy–combustion applications.

Keywords: absorption, carbon capture, partial oxy-combustion, solvent

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Authors: Nkwachukwu Chukwuchekwa, Joy Ulumma Chukwuchekwa

Abstract:

Magnetic characteristics of grain-oriented electrical steel (GOES) are usually measured at high flux densities suitable for its typical applications in power transformers. There are limited magnetic data at low flux densities which are relevant for the characterization of GOES for applications in metering instrument transformers and low frequency magnetic shielding in magnetic resonance imaging medical scanners. Magnetic properties such as coercivity, B-H loop, AC relative permeability and specific power loss of conventional grain oriented (CGO) and high permeability grain oriented (HGO) electrical steels were measured and compared at high and low flux densities at power magnetising frequency. 40 strips comprising 20 CGO and 20 HGO, 305 mm x 30 mm x 0.27 mm from a supplier were tested. The HGO and CGO strips had average grain sizes of 9 mm and 4 mm respectively. Each strip was singly magnetised under sinusoidal peak flux density from 8.0 mT to 1.5 T at a magnetising frequency of 50 Hz. The novel single sheet tester comprises a personal computer in which LabVIEW version 8.5 from National Instruments (NI) was installed, a NI 4461 data acquisition (DAQ) card, an impedance matching transformer, to match the 600  minimum load impedance of the DAQ card with the 5 to 20  low impedance of the magnetising circuit, and a 4.7 Ω shunt resistor. A double vertical yoke made of GOES which is 290 mm long and 32 mm wide is used. A 500-turn secondary winding, about 80 mm in length, was wound around a plastic former, 270 mm x 40 mm, housing the sample, while a 100-turn primary winding, covering the entire length of the plastic former was wound over the secondary winding. A standard Epstein strip to be tested is placed between the yokes. The magnetising voltage was generated by the LabVIEW program through a voltage output from the DAQ card. The voltage drop across the shunt resistor and the secondary voltage were acquired by the card for calculation of magnetic field strength and flux density respectively. A feedback control system implemented in LabVIEW was used to control the flux density and to make the induced secondary voltage waveforms sinusoidal to have repeatable and comparable measurements. The low noise NI4461 card with 24 bit resolution and a sampling rate of 204.8 KHz and 92 KHz bandwidth were chosen to take the measurements to minimize the influence of thermal noise. In order to reduce environmental noise, the yokes, sample and search coil carrier were placed in a noise shielding chamber. HGO was found to have better magnetic properties at both high and low magnetisation regimes. This is because of the higher grain size of HGO and higher grain-grain misorientation of CGO. HGO is better CGO in both low and high magnetic field applications.

Keywords: flux density, electrical steel, LabVIEW, magnetization

Procedia PDF Downloads 275