Search results for: density of wood

Authors: Jon Ajuria, Edurne Redondo, Roman Mysyk, Eider Goikolea

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Hybrid capacitor configurations are now of increasing interest to overcome the current energy limitations of supercapacitors entirely based on non-Faradaic charge storage. Among them, Li-ion capacitors including a negative battery-type lithium intercalation electrode and a positive capacitor-type electrode have achieved tremendous progress and have gone up to commercialization. Inexpensive electrode materials from renewable sources have recently received increased attention since cost is a persistently major criterion to make supercapacitors a more viable energy solution, with electrode materials being a major contributor to supercapacitor cost. Additionally, Na-ion battery chemistries are currently under development as less expensive and accessible alternative to Li-ion based battery electrodes. In this work, we are presenting both lithium and sodium ion capacitor (LIC & NIC) entirely based on electrodes prepared from carbon materials derived from recycled olive pits. Yearly, around 1 million ton of olive pit waste is generated worldwide, of which a third originates in the Spanish olive oil industry. On the one hand, olive pits were pyrolized at different temperatures to obtain a low specific surface area semigraphitic hard carbon to be used as the Li/Na ion intercalation (battery-type) negative electrode. The best hard carbon delivers a total capacity of 270mAh/g vs Na/Na+ in 1M NaPF6 and 350mAh/g vs Li/Li+ in 1M LiPF6. On the other hand, the same hard carbon is chemically activated with KOH to obtain high specific surface area -about 2000 m2g-1- activated carbon that is further used as the ion-adsorption (capacitor-type) positive electrode. In a voltage window of 1.5-4.2V, activated carbon delivers a specific capacity of 80 mAh/g vs. Na/Na+ and 95 mAh/g vs. Li/Li+ at 0.1A /g. Both electrodes were assembled in the same hybrid cell to build a LIC/NIC. For comparison purposes, a symmetric EDLC supercapacitor cell using the same activated carbon in 1.5M Et4NBF4 electrolyte was also built. Both LIC & NIC demonstrates considerable improvements in the energy density over its EDLC counterpart, delivering a maximum energy density of 110Wh/Kg at a power density of 30W/kg AM and a maximum power density of 6200W/Kg at an energy density of 27 Wh/Kg in the case of NIC and a maximum energy density of 110Wh/Kg at a power density of 30W/kg and a maximum power density of 18000W/Kg at an energy density of 22 Wh/Kg in the case of LIC. In conclusion, our work demonstrates that the same biomass waste can be adapted to offer a hybrid capacitor/battery storage device overcoming the limited energy density of corresponding double layer capacitors.

Keywords: hybrid supercapacitor, Na-Ion capacitor, supercapacitor, Li-Ion capacitor, EDLC

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Authors: Aasheesh Raturi, Vimal Kothiyal, P. D. Semalty

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We studied mechanical properties of Eucalyptus tereticornis using FT-NIR spectroscopy. Firstly, spectra were pre-processed to eliminate useless information. Then, prediction model was constructed by partial least squares regression. To study the influence of pre-processing on prediction of mechanical properties for NIR analysis of wood samples, we applied various pretreatment methods like straight line subtraction, constant offset elimination, vector-normalization, min-max normalization, multiple scattering. Correction, first derivative, second derivatives and their combination with other treatment such as First derivative + straight line subtraction, First derivative+ vector normalization and First derivative+ multiplicative scattering correction. The data processing methods in combination of preprocessing with different NIR regions, RMSECV, RMSEP and optimum factors/rank were obtained by optimization process of model development. More than 350 combinations were obtained during optimization process. More than one pre-processing method gave good calibration/cross-validation and prediction/test models, but only the best calibration/cross-validation and prediction/test models are reported here. The results show that one can safely use NIR region between 4000 to 7500 cm-1 with straight line subtraction, constant offset elimination, first derivative and second derivative preprocessing method which were found to be most appropriate for models development.

Keywords: FT-NIR, mechanical properties, pre-processing, PLS

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Authors: Philip Edinger, Christian Ludwig

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The formation and control of tars remain one of the major challenges in the implementation of biomass gasification technologies. Robust, on-line analytical methods are needed to investigate the fate of tar compounds when different measures for their reduction are applied. This work establishes an on-line UV-Vis method, based on a liquid quench sampling system, to monitor tar compounds in biomass gasification processes. Recorded spectra from the liquid phase were analyzed for their tar composition by means of a classical least squares (CLS) and partial least squares (PLS) approach. This allowed for the detection of UV-Vis active tar compounds with detection limits in the low part per million by volume (ppmV) region. The developed method was then applied to two case studies. The first involved a lab-scale reactor, intended to investigate the decomposition of a limited number of tar compounds across a catalyst. The second study involved a gas scrubber as part of a pilot scale wood gasification plant. Tar compound quantification results showed good agreement with off-line based reference methods (GC-FID) when the complexity of tar composition was limited. The two case studies show that the developed method can provide rapid, qualitative information on the tar composition for the purpose of process monitoring. In cases with a limited number of tar species, quantitative information about the individual tar compound concentrations provides an additional benefit of the analytical method.

Keywords: biomass gasification, on-line, tar, UV-Vis

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Authors: E. Obreque-Slier, P. Osorio-Umaña, G. Vidal-Acevedo, A. Peña-Neira, M. Medel-Marabolí

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Sensory and nutraceutical characteristics of a wine are determined by different chemical compounds, such as organic acids, sugars, alcohols, polysaccharides, aromas, and polyphenols. The polyphenols correspond to secondary metabolites that are associated with the prevention of several pathologies, and those are responsible for color, aroma, bitterness, and astringency in wines. These compounds come from grapes and wood during aging in barrels, which correspond to the format of wood most widely used in wine production. However, the barrels is a high-cost input with a limited useful life (3-4 years). For this reason, some oenological products have been developed in order to renew the barrels and increase their useful life in some years. These formats are being used slowly because limited information exists about the effect on the wine chemical characteristics. The objective of the study was to evaluate the effect of different laubarrel renewal systems (staves and zigzag) on the polyphenolic characteristics of a Carménère wine (Vitis vinifera), an emblematic cultivar of Chile. For this, a completely randomized experimental design with 5 treatments and three replicates per treatment was used. The treatments were: new barrels (T0), used barrels during 4 years (T1), scraped used barrels (T2), used barrels with staves (T3) and used barrels with zigzag (T4). The study was performed for 12 months, and different spectrophotometric parameters (phenols, anthocyanins, and total tannins) and HPLC-DAD (low molecular weight phenols) were evaluated. The wood inputs were donated by Toneleria Nacional and corresponded to products from the same production batch. The total phenols content increased significantly after 40 days, while the total tannin concentration decreased gradually during the study. The anthocyanin concentration increased after 120 days of the assay in all treatments. Comparatively, it was observed that the wine of T2 presented the lowest values of these polyphenols, while the T0 and T4 presented the highest total phenol contents. Also, T1 presented the highest values of total tannins in relation to the rest of the treatments in some samples. The low molecular weight phenolic compounds identified by HPLC-DAD were 7 flavonoids (epigallocatechin, catechin, procyanidin gallate, epicatechin, quercetin, rutin and myricetin) and 14 non-flavonoids (gallic, protocatechuic, hydroxybenzoic, trans-cutaric, vanillinic, caffeic, syringic, p-coumaric and ellagic acids; tyrosol, vanillin, syringaldehyde, trans-resveratrol and cis-resveratrol). Tyrosol was the most abundant compound, whereas ellagic acid was the lowest in the samples. Comparatively, it was observed that the wines of T2 showed the lowest concentrations of flavonoid and non-flavonoid phenols during the study. In contrast, wines of T1, T3, and T4 presented the highest contents of non-flavonoid polyphenols. In summary, the use of barrel renovators (zig zag and staves) is an interesting alternative which would emulate the contribution of polyphenols from the barrels to the wine.

Keywords: barrels, oak wood aging, polyphenols, red wine

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Authors: Abdalla Ahmad Obeidat

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Developing efficient hydrogen storage materials is critical to advancing clean energy technologies, particularly for applications in fuel cells and renewable energy systems. This study explores materials for hydrogen storage through Density Functional Theory (DFT) calculations, addressing one of the most significant challenges in sustainable energy: the safe and efficient storage and release of hydrogen. Our research provides an in-depth analysis of various candidate compounds' structural and electronic properties, aiming to identify materials with enhanced hydrogen storage capacities. By investigating adsorption mechanisms and optimizing key material properties, we aim to contribute to developing high-performance hydrogen storage solutions. The findings from this work have the potential to impact the field of hydrogen fuel technology significantly, offering insights and advancements that support the transition to sustainable energy systems.

Keywords: hydrogen storage, density functional theory, electronic, thermal stability

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Authors: Lamla Thungathaa, Conrad Mahlasea, Lisa Ngcebesha

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1,4-Diamino-3,6-dinitropyrazolo[4,3-c]pyrazole (LLM-119) and its structural isomer 3,6-dinitropyrazolo[3,4-c]pyrazole-1,4(6H)-diamine were designed by structural reorientation of the fused pyrazole rings and their respective substituents (-NO2 and -NH2). Structural reorientation involves structural rearrangement which result in different structural isomers, employing this approach, six structural isomers of LLM-119 were achieved. The effect of structural reorientation (isomerisation and derivatives) on the enthalpy of formation, detonation properties, impact sensitivity, and density of these molecules is studied Computationally. The computational method used are detailed in the document and they yielded results that are close to the literature values with a relative error of 2% for enthalpy of formation, 2% for density, 0.05% for detonation velocity, and 4% for detonation pressure. The correlation of the structural reorientation to the calculated thermochemical and detonation properties of the molecules indicated that molecules with a -NO2 group attached to a Carbon atom and -NH2 connected to a Nitrogen atom maximize the enthalpy of formation and detonation velocity. The joining of pyrazole molecules has less effect on these parameters. It was seen that density and detonation pressure improved when both –NO2 or -NH2 functional groups were on the same side of the molecular structure. The structural reorientation gave rise to 3,4-dinitropyrazolo[3,4-c]pyrazole-1,6-diamine which exhibited optimal density and detonation performance compared to other molecules.

Keywords: LLM-119, fused rings, azole, structural isomers, detonation properties

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Authors: Yu-Jen Shih, Yao-Hui Hunag

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Electrocoagulation (EC) using metallic nickel foam as anode and cathode for the removal of boron from solution was studied. The electrolytic parameters included pH, current density, and initial boron concentration for optimizing the EC process. Experimental results showed that removal efficiency was increased by elevating pH from 4.0 to 8.0, and then decreased at higher pH. The electrolytic efficacy was not affected by current density. In respect of energy consumption, 1.25 mA/cm2 of current density was acceptable for an effective EC of boron, while increasing boric acid from 10 to 100 ppm-B did not impair removal efficiency too much. Cyclic voltammetry indicated that the oxide film, Ni(OH)2 and NiOOH, at specific overpotentials would result in less weight loss of anode than that predicted by the Faraday’s law. The optimal conditions under which 99.2% of boron was removed and less than 1 ppm-B remained in the electrolyte would be pH 8, four pairs of electrodes, and 1.25 mA/cm2 in 120 min as treating wastewaters containing 10 ppm-B. XRD and SEM characterization suggested that the granular crystallites of hydroxide precipitates was composed of theophrastite.

Keywords: borohydrides, hydrogen generation, NiOOH, electrocoagulation, cyclic voltammetry, boron removal

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Authors: Acumsiri Tantikarnpanit

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This paper aims to examine the relationship between urbanization and income inequality in Thailand during the period 2002–2020. Using a panel of data for 76 provinces collected from Thailand’s National Statistical Office (Labor Force Survey: LFS), as well as geospatial data from the U.S. Air Force Defense Meteorological Satellite Program (DMSP) and the Visible Infrared Imaging Radiometer Suite Day/Night band (VIIRS-DNB) satellite for nineteen selected years. This paper employs two different definitions to identify urban areas: 1) Urban areas defined by Thailand's National Statistical Office (Labor Force Survey: LFS), and 2) Urban areas estimated using nighttime light data from the DMSP and VIIRS-DNB satellite. The second method includes two sub-categories: 2.1) Determining urban areas by calculating nighttime light density with a population density of 300 people per square kilometer, and 2.2) Calculating urban areas based on nighttime light density corresponding to a population density of 1,500 people per square kilometer. The empirical analysis based on Ordinary Least Squares (OLS), fixed effects, and random effects models reveals a consistent U-shaped relationship between income inequality and urbanization. The findings from the econometric analysis demonstrate that urbanization or population density has a significant and negative impact on income inequality. Moreover, the square of urbanization shows a statistically significant positive impact on income inequality. Additionally, there is a negative association between logarithmically transformed income and income inequality. This paper also proposes the inclusion of satellite imagery, geospatial data, and spatial econometric techniques in future studies to conduct quantitative analysis of spatial relationships.

Keywords: income inequality, nighttime light, population density, Thailand, urbanization

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Authors: Hamid Mustafa, Huson J. Heather, Kim Eiusoo, Adeela Ajmal, Tad S. Sonstegard

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The objective of this study was to evaluate the informativeness of Bovine high density SNPs genotyping in Sahiwal cattle population. This is a first attempt to assess the Bovine HD SNP genotyping array in any Pakistani indigenous cattle population. To evaluate these SNPs on genome wide scale, we considered 777,962 SNPs spanning the whole autosomal and X chromosomes in Sahiwal cattle population. Fifteen (15) non related gDNA samples were genotyped with the bovine HD infinium. Approximately 500,939 SNPs were found polymorphic (MAF > 0.05) in Sahiwal cattle population. The results of this study indicate potential application of Bovine High Density SNP genotyping in Pakistani indigenous cattle population. The information generated from this array can be applied in genetic prediction, characterization and genome wide association studies of Pakistani Sahiwal cattle population.

Keywords: Sahiwal cattle, polymorphic SNPs, genotyping, Pakistan

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Authors: Nasrin Bakhshizadeh, Ashkan Forootan

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A major problem that affects the quality control of polymer in the industrial polymerization is the lack of suitable on-line measurement tools to evaluate the properties of the polymer such as melt and density indices. Controlling the polymerization in ordinary method is performed manually by taking samples, measuring the quality of polymer in the lab and registry of results. This method is highly time consuming and leads to producing large number of incompatible products. An online application for estimating melt index and density proposed in this study is a neural network based on the input-output data of the polyethylene production plant. Temperature, the level of reactors' bed, the intensity of ethylene mass flow, hydrogen and butene-1, the molar concentration of ethylene, hydrogen and butene-1 are used for the process to establish the neural model. The neural network is taught based on the actual operational data and back-propagation and Levenberg-Marquart techniques. The simulated results indicate that the neural network process model established with three layers (one hidden layer) for forecasting the density and the four layers for the melt index is able to successfully predict those quality properties.

Keywords: polyethylene, polymerization, density, melt index, neural network

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Authors: Baghdasaryan Marinka

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Monitoring the distribution of electric power consumption in the technological process of ore grinding is conducted. As a result, the impacts of the mill filling rate, the productivity of the ore supply, the volumetric density of the grinding balls, the specific density of the ground ore, and the relative speed of the mill rotation on the specific consumption of electric power have been studied. The power and technological factors affecting the reactive power generated by the synchronous motors, operating within the technological scheme are studied. A block diagram for evaluating the power consumption modes of the technological process is presented, which includes the analysis of the technological scheme, the determination of the place and volumetric density of the ore-grinding mill, the evaluation of the technological and power factors affecting the energy saving process, as well as the assessment of the electric power standards.

Keywords: electric power standard, factor, ore grinding, power consumption, reactive power, technological

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Authors: Rajendra Kumar

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We study the Electronic spectral density of a double coupled quantum dots sandwich between superconducting leads, where one of the superconducting leads (QD1) are connected with left superconductor lead and (QD1) also connected right superconductor lead. (QD1) and (QD2) are coupling to each other. The electronic spectral density through a quantum dots between superconducting leads having s-wave symmetry of the superconducting order parameter. Such junction is called superconducting –quantum dot (S-QD-S) junction. For this purpose, we have considered a renormalized Anderson model that includes the double coupled of the superconducting leads with the quantum dots level and an attractive BCS-type effective interaction in superconducting leads. We employed the Green’s function technique to obtain superconducting order parameter with the BCS framework and Ambegaoker-Baratoff formalism to analyze the electronic spectral density through such (S-QD-S) junction. It has been pointed out that electronic spectral density through such a junction is dominated by the attractive the paring interaction in the leads, energy of the level on the dot with respect to Fermi energy and also on the coupling parameter of the two in an essential way. On the basis of numerical analysis we have compared the theoretical results of electronic spectral density with the recent transport existing theoretical analysis. QDs is the charging energy that may give rise to effects based on the interplay of Coulomb repulsion and superconducting correlations. It is, therefore, an interesting question to ask how the discrete level spectrum and the charging energy affect the DC and AC Josephson transport between two superconductors coupled via a QD. In the absence of a bias voltage, a finite DC current can be sustained in such an S-QD-S by the DC Josephson effect.

Keywords: quantum dots, S-QD-S junction, BCS superconductors, Anderson model

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Authors: Claudia H. Swanson, Jens Günster

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This research addresses the densification via compaction and sintering of naturally occurring rock salt which was motivated by the fact that in a saline environment rock salt is thermodynamically stable and does show a mechanical behavior compatible to the surrounding host material. The sintering of rock salt powder compacts was systematically investigated using temperature and pressure as variables for the sinter process. The behavior of rock salt showed segregations of anhydrite, CaSO4 - the major impurity found in rock salt, to the grain boundaries between individual sodium chloride crystals. Powder compacts treated with lower pressures lost those anhydrite segregates over time while high pressure treated compacts remained with anhydrite segregates. The density reached in this study is 2.008 g cm-3 corresponding to a density of 92.5 % of the theoretical value. This high density is making the sintering a promising technique for rock salt as applications in underground appropriate environment.

Keywords: rock salt, sinter, anhydrite, nuclear safety

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Authors: Zhao Yang Liu, Jing Tao

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The Asian long-horned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae: Lamiinae), is a wood-borer and polyphagous xylophages native to Asia and killing healthy trees. As it causes serious danger to trees, the beetle has been paid close attention in the world. However, the genetic markers limited, especially microsatellite. In this study, 24 novel simple sequence repeat (SSR) molecular markers, a powerful tool for genetic diversity studies and linkage map construction, were developed and characterized from whole genome shotgun sequences. We developed SSR loci of 2 to 6 repeated and perfect units including 9895 points, the density of SSRs was found one SSR per 56.57 kb and the abundance of SSR was 0.02/kb, besides 140 types of repeats motifs were found. Half of the 48 pairs SSR primers (containing 4 di-, 7 tri-, 2 tetra- and 11 hexamers SSRs) we selected randomly from 1222 pairs of primers were polymorphism. The number of alleles for these markers in 48 individuals varied from 3 to 21 with an average of 7.71, the number of effective alleles ranged from 1.22 to 9.97 with an average of 3.54. Besides this, the polymorphic information content (PIC) ranged from 0.18 to 0.89 with a mean of 0.65, And Shannon's Information index (I) ranged from 0.46 to 2.62 with an average of 1.44. The results suggest that the method for screening of SSR in the whole genome is feasible and efficient. SSR markers developed in this study can be used for population genetic studies of A. glabripennis. Moreover, they may also be helpful for the development of microsatellites for other Coleoptera.

Keywords: SSR markers, Anoplophora glabripennis, genetic diversity, whole genome

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Authors: Neetu Malik, Sharad Shrivastava, Subrata Bandhu Ghosh

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Biocomposite materials were fabricated using mixing biodegradable polymer polycaprolactone (PCL) and Thermally Exfoliated Graphene Oxide (TEGO) through solution casting. Various samples of biocomposite films were prepared by varying the TEGO wt% composition by 0.1%, 0.5%, 1% and 1.5%. Thereafter, the density and water absorption of the composites were investigated with respect to immersion time in water. The moisture absorption results show that with an increase in weight percentage (from 0.1 to wt 1.5%) of TEGO within the biopolymer films, the absorption value of bio-nanocomposite films reduced rapidly from 27.4% to 14.3%. The density of hybrid composites also increased with increase in weight percentage of TEGO. These results indicate that the optimized composition of constituents in composite membrane could effectively reduce the anhydrous conditions of bio-composite film.

Keywords: thermally exfoliated graphene oxide, PCL, water absorption, density

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Authors: Waris Piyaphon, Sathaphorn O-Suwankul, Kittima Bootdee, Manit Nithitanakul

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Starch from rice was used as a filler in low density polyethylene in preparation of low density polyethylene/rice starch composite. This study aims to prepare LDPE/rice starch composites. Glycerol (GC) was used as a plasticizer in order to increase dispersion and reduce agglomeration of rice starch in low density polyethylene (LDPE) matrix. Low density polyethylene grafted maleic anhydride (LDPE-g-MA) was used as a compatibilizer to increase the compatibility between LDPE and rice starch. The content of rice starch was varied between 10, 20, and 30 %wt. Results indicated that increase of rice starch content reduced tensile strength at break, elongation, and impact strength of composites. LDPE-g-MA showed positive effect on mechanical properties which increased in tensile strength and impact properties as well as compatibility between rice starch and LDPE matrix. Moreover, the addition of LDPE-g-MA significantly improved the impact strength by 50% compared to neat composite. The incorporation of GC enhanced the processability of composite. Introduction of GC affected the viscosity after blending by reducing the viscosity at all shear rate. The presence of plasticizer increased the impact strength but decreased the stiffness of composite. Water absorption of the composite was increased when plasticizer was added.

Keywords: composite material, plastic starch composite, polyethylene composite, PE grafted maleic anhydride

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Authors: T. Zergoug, S. E. H. Abaidia, A. Nedjar, M. Y. Mokeddem

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Physical properties of uranium di-nitride (UN2) were investigated in detail using first principles calculations based on density functional theory. To treat the strong correlation effects caused by 5f Uranium valence electrons, on-site Coulomb interaction correction via the Hubbard-like term, U (DFT+U) was employed. The UN2 structural, mechanical and thermodynamic properties were calculated within DFT and Various U of DFT+U approach. The Perdew–Burke–Ernzerhof (PBE.5.2) version of the generalized gradient approximation (GGA) is used to describe the exchange-correlation with the projector-augmented wave (PAW) pseudo potentials. A comparative study shows that results are improved by using the Hubbard formalism for a certain U value correction like the structural parameter. For some physical properties the variation versus Hubbard U is strong like Young modulus but for others it is weakly noticeable such as the density of state (DOS) or bulk modulus. We noticed also that up from U=7.5 eV, elastic results become not conform to the cubic cell elastic criteria since the C44 values turn out to be negative.

Keywords: uranium diNitride, UN2, DFT+U, elastic properties

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Authors: E. M. D. Akuoko, Eliana Vasquez Osorio, Marcel Van Herk, Marianne Aznar

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Radiotherapy is an integral part of treatment for many patients with breast cancer. However, side effects can occur, e.g., fibrosis or erythema. If patients at higher risks of radiation-induced side effects could be identified before treatment, they could be given more individual information about the risks and benefits of radiotherapy. We hypothesize that breast density is correlated with the risk of side effects and present a novel method for automatic evaluation based on radiotherapy planning CT scans. Methods: 799 supine CT scans of breast radiotherapy patients were available from the REQUITE dataset. The methodology was first established in a subset of 114 patients (cohort 1) before being applied to the whole dataset (cohort 2). All patients were scanned in the supine position, with arms up, and the treated breast (ipsilateral) was identified. Manual experts contour available in 96 patients for both the ipsilateral and contralateral breast in cohort 1. Breast tissue was segmented using atlas-based automatic contouring software, ADMIRE® v3.4 (Elekta AB, Sweden). Once validated, the automatic segmentation method was applied to cohort 2. Breast density was then investigated by thresholding voxels within the contours, using Otsu threshold and pixel intensity ranges based on Hounsfield units (-200 to -100 for fatty tissue, and -99 to +100 for fibro-glandular tissue). Volumetric breast density (VBD) was defined as the volume of fibro-glandular tissue / (volume of fibro-glandular tissue + volume of fatty tissue). A sensitivity analysis was performed to verify whether calculated VBD was affected by the choice of breast contour. In addition, we investigated the correlation between volumetric breast density (VBD) and patient age and breast size. VBD values were compared between ipsilateral and contralateral breast contours. Results: Estimated VBD values were 0.40 (range 0.17-0.91) in cohort 1, and 0.43 (0.096-0.99) in cohort 2. We observed ipsilateral breasts to be denser than contralateral breasts. Breast density was negatively associated with breast volume (Spearman: R=-0.5, p-value < 2.2e-16) and age (Spearman: R=-0.24, p-value = 4.6e-10). Conclusion: VBD estimates could be obtained automatically on a large CT dataset. Patients’ age or breast volume may not be the only variables that explain breast density. Future work will focus on assessing the usefulness of VBD as a predictive variable for radiation-induced side effects.

Keywords: breast cancer, automatic image segmentation, radiotherapy, big data, breast density, medical imaging

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Authors: Noureddine Benharkat, Abdelkader Chouaih, Nourdine Boukabcha

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A thiourea derivative compound was synthesized and subjected to structural analysis using single-crystal X-ray diffraction (XRD). The crystallographic data unveiled its crystallization in the P21/c space group within the monoclinic system. Examination of the dihedral angles indicated a notable non-planar structure. To support and interpret these resulats, density functional theory (DFT) calculations were conducted utilizing the B3LYP functional along with a 6–311 G (d, p) basis set. Additionally, to assess the contribution of intermolecular interactions, Hirshfeld surface analysis and 2D fingerprint plots were employed. Various types of interactions, whether weak intramolecular or intermolecular, within a molecule can significantly impact its stability. The distinctive signature of non-covalent interactions can be detected solely through electron density analysis. The NCI-RDG analysis was employed to investigate both repulsive and attractive van der Waals interactions while also calculating the energies associated with intermolecular interactions and their characteristics. Additionally, a molecular docking study was studied to explain the structure-activity relationship, revealing that the title compound exhibited an affinity energy of -6.8 kcal/mol when docked with B-DNA (1BNA).

Keywords: computational chemistry, density functional theory, crystallography, molecular docking, molecular structure, powder x-ray diffraction, single crystal x-ray diffraction

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Authors: Fatemeh Safdari, Amirnaser Shamkhali, Gholamabbas Parsafar

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Carbon nanostructures are of great importance in academic research and industry, which can be mentioned to chemical sensors, catalytic processes, pharmaceutical and environmental issues. Common point in all of these applications is the occurrence of adsorption of molecules on these structures. Important carbon nanostructures in this case are mainly nanotubes and graphene. To modify pure graphene, recently, many experimental and theoretical studies have carried out to investigate of metal adsorption on graphene. In this work, the adsorption of CO molecules on pure graphene and on metal adatom on graphene surface has been simulated based on density functional theory (DFT). All calculations were performed by PBE functional and Troullier-Martins pseudopotentials. Density of states (DOS) for graphene-CO, graphen and CO around the Fermi energy has been moved and very small mixing occured which implies the physisorption of CO on the bare graphen surface. While, the results have showed that CO adsorption on transition-metal adatom on graphene surface is chemisorption.

Keywords: adsorption, density functional theory, graphene, metal adatom

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Authors: Yaping Zhao

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In the present study, the exact solutions for the steady response of quasi-linear systems under non-white wide-band random excitation are considered by means of the stochastic averaging method. The non linearity of the systems contains the power-law damping and the cross-product term of the power-law damping and displacement. The drift and diffusion coefficients of the Fokker-Planck-Kolmogorov (FPK) equation after averaging are obtained by a succinct approach. After solving the averaged FPK equation, the joint probability density function and the marginal probability density function in steady state are attained. In the process of resolving, the eigenvalue problem of ordinary differential equation is handled by integral equation method. Some new results are acquired and the novel method to deal with the problems in nonlinear random vibration is proposed.

Keywords: random vibration, stochastic averaging method, FPK equation, transition probability density

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Authors: Rubab Zafar Kahlon, Ibtisam Butt

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Forest resources are deteriorating and experiencing decline around the globe due to unsustainable use and over exploitation. The present study was an attempt to determine the relationship between human activities, forest resource utilization, extraction methods and practices of forest resource exploitation in the district Jhelum of Pakistan. For this purpose, primary sources of data were used which were collected from 8 villages through structured questionnaire and tabulated in Microsoft Excel 365 and SPSS 22 was used for multiple linear regression analysis. The results revealed that farming, wood cutting, animal husbandry and agro-forestry were the major occupations in the study area. Most commonly used resources included timber 26%, fuelwood 25% and fodder 19%. Methods used for resource extraction included gathering 49%, plucking 34% trapping 11% and cutting 6%. Population growth, increased demand of fuelwood and land conversion were the main reasons behind forest degradation. Results for multiple linear regression revealed that Forest based activities, sources of energy production, methods used for wood harvesting and resource extraction and use of fuelwood for energy production contributed significantly towards extensive forest resource exploitation with p value <0.5 within the study area. The study suggests that effective measures should be taken by forest department to control the unsustainable use of forest resources by stringent management interventions and awareness campaigns in Jhelum district.

Keywords: forest resource, biodiversity, expliotation, human activities

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Authors: Moulay Driss Mellaoui, Abdallah Imjjad, Rachid Boutiddar, Haydar Mohammad-Salim, Nivedita Acharjee, Hassan Bourzi, Souad El Issami, Khalid Abbiche, Hanane Zejli

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We have investigated the underlying molecular processes involved in the [3+2] cycloaddition (32CA) reactions between N-methyl-C-(2-furyl) nitrone and three acetylene derivatives: 4b, 5b, and 6b. For this investigation, we utilized molecular electron density theory (MEDT) and density functional theory (DFT) methods at the B3LYP-D3/6 31G (d) computational level. These 32CA reactions, which exhibit a zwitterionic (zw-type) nature, proceed through a one-step mechanism with activation enthalpies ranging from 8.80 to 14.37 kcal mol−1 in acetonitrile and ethanol solvents. When the nitrone reacts with phenyl methyl propiolate (4b), two regioisomeric pathways lead to the formation of two products: P1,5-4b and P1,4-4b. On the other hand, when the nitrone reacts with dimethyl acetylene dicarboxylate (5b) and acetylene dicarboxylic acid (but-2-ynedioic acid) (6b), it results in the formation of a single product. Through topological analysis, we can categorize the nitrone as a zwitterionic three-atom component (TAC). Furthermore, the analysis of conceptual density functional theory (CDFT) indices classifies the 32CA reactions of the nitrone with 4b, 5b, and 6b as forward electron density flux (FEDF) reactions. The study of bond evolution theory (BET) reveals that the formation of new C-C and C-O covalent bonds does not initiate in the transition states, as the intermediate stages of these reactions display pseudoradical centers of the atoms already involved in bonding.

Keywords: 4-isoxazoline, DFT/B3LYP-D3, regioselectivity, cycloaddition reaction, MEDT, ELF

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Authors: Reza Miresmaeili, Asghar Heydari Astaraee, Fereshteh Dolati

Abstract:

In the present study, an analytical model based on dislocation density model was developed to simulate grain refinement in surface mechanical attrition treatment (SMAT). The correlation between SMAT time and development in plastic strain on one hand, and dislocation density evolution, on the other hand, was established to simulate the grain refinement in SMAT. A dislocation density-based constitutive material law was implemented using VUHARD subroutine. A random sequence of shots is taken into consideration for multiple impacts model using Python programming language by utilizing a random function. The simulation technique was to model each impact in a separate run and then transferring the results of each run as initial conditions for the next run (impact). The developed Finite Element (FE) model of multiple impacts describes the coverage evolution in SMAT. Simulations were run to coverage levels as high as 4500%. It is shown that the coverage implemented in the FE model is equal to the experimental coverage. It is depicted that numerical SMAT coverage parameter is adequately conforming to the well-known Avrami model. Comparison between numerical results and experimental measurements for residual stresses and depth of deformation layers confirms the performance of the established FE model for surface engineering evaluations in SMA treatment. X-ray diffraction (XRD) studies of grain refinement, including resultant grain size and dislocation density, were conducted to validate the established model. The full width at half-maximum in XRD profiles can be used to measure the grain size. Numerical results and experimental measurements of grain refinement illustrate good agreement and show the capability of established FE model to predict the gradient microstructure in SMA treatment.

Keywords: dislocation density, grain refinement, severe plastic deformation, simulation, surface mechanical attrition treatment

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Authors: M. Mesrouk, A. Hadj Arab

Abstract:

This work allows highlight the effect of dust on the absorption of the optical spectrum on the photovoltaic module, the effect of the particles dust presence on the photovoltaic modules have been a microscopic scale studied with COMSOL Multi-physic software simulation. In this paper, we have supposed the dust layer as a diffraction network repetitive optical structure characterized by the spacing between particle which represented by 'd' and the simulated structure (air-dust particle-glass). In this study we can observe the relationship between the wavelength and the particle spacing, the simulation shows us that the maximum wavelength transmission value corresponding, λ0 = 400nm, which represent the spacing value between the particles dust, d = 400 nm. In fact, we can observe that while increase dust layer density the wavelength transmission value decrease, there is a relationship between the density and wavelength value which can be absorbed in a dusty photovoltaic panel.

Keywords: dust effect, photovoltaic module, spectral absorption, wavelength transmission

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Authors: Kajal Zarei

Abstract:

Supply chain management is becoming an increasingly important issue in many businesses today. In such circumstances, a number of reasons such as management deficiency in different segments of the supply chain, lack of streamlined processes, resistance to change the current systems and technologies, and lack of advanced information system have paved the ground to ask for innovative research studies. To this end, information technology (IT) is becoming a major driver to overcome the supply chain limitations and deficiencies. The emergence of IT has provided an excellent opportunity for redefining the supply chain to be more effective and competitive. This paper has investigated the IT impact on two-digit industry codes in the International Standard Industrial Classification (ISIC) that are operating in four groups of the supply chains. Firstly, the primary fields of the supply chain were investigated, and then paired comparisons of different industry parts were accomplished. Using experts' ideas and Analytical Hierarchy Process (AHP), the status of industrial activities in Kurdistan Province in Iran was determined. The results revealed that manufacturing and inventory fields have been more important compared to other fields of the supply chain. In addition, IT has had greater impact on food and beverage industry, chemical industry, wood industry, wood products, and production of basic metals. The results indicated the need to IT awareness in supply chain management; in other words, IT applications needed to be developed for the identified industries.

Keywords: supply chain, information technology, analytical hierarchy process, two-digit codes, international standard industrial classification

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Authors: Mohammad Amjad Sabir, Ishtiaq Khan, Shahid Ali, Umar Shabbir, Aneel Ahmad

Abstract:

Creep, being the main silt contributor to the rivers, is a slow, downhill flow of soils. The creep velocity is measured in millimeters to a couple of centimeters per year and is determined with the help of tilt caused by creep in the vertical objects and needs at least ten years to get a reliable creep velocity. This project was devised to calculate creep velocity using dendrochronology and looking for the difference of creep velocity registered by different trees on the same slope. It was concluded that dendrochronology provides a very reliable procedure of creep velocity estimation if ‘J’ shaped trees are studied for their horizontal movement and age. The age of these trees was measured using tree coring, and the horizontal movement was measured with a conventional tape. Using this procedure it does not require decades and additionally the data reveals the creep velocity for up to 150 years and even more instead of just a decade. It was also concluded that the creep velocity does not only depend on bulk density of soil hence no pronounced effect of bulk density was detected.

Keywords: creep velocity, Galiyat, Pakistan, dendrochronology, Nagri Bala

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Authors: Mahdi Almaky

Abstract:

The thermostabilization of High Density Polyethylene (HDPE) is realized through the action of primary antioxidant such as phenolic antioxidants and secondary antioxidants as aryl phosphates. The efficiency of two secondary antioxidants, commercially named Irgafos 168 and Weston 399, was investigated using different physical, mechanical, spectroscopic, and calorimetric methods. The effect of both antioxidants on the processing stability and long term stability of HDPE produced in Ras Lanuf oil and gas processing Company were measured and compared. The combination of Irgafos 168 with Irganox 1010, as used in smaller concentration, results in a synergetic effect against thermo-oxidation and protect better than the combination of Weston 399 with Irganox 1010 against the colour change at processing temperature and during long term oxidation process.

Keywords: thermostabilization, high density polyethylene, primary antioxidant, phenolic antioxidant, Irgafos 168, Irganox 1010, Weston 399

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Authors: Irfan Ahmad, Raza Ghafoor, Hammad Raza Ahmad, Muhammad Asif, Farrakh Nawaz, M. Tahir Siddiqui

Abstract:

Due to the exploding population of Pakistan the pressure on natural forests is increasing to meet the demands of wood and wood based products. Agroforestry is being practiced throughout the world on scientific basis but unfortunately the farmers of Pakistan are reluctant in its adoption. The presents study was designed to assess the adoption of agroforestry practices in Faisalabad with respect to land holdings of farmers and future suitability by using Geographic information system (GIS). Faisalabad is the third largest city of the country and is famous due to the textile industry. A comprehensive survey from target villages of the Lyallpur town of Faisalabad district was carried out. Out of total 65 villages, 40 were selected for study. From each selected village, one farmer who was actively engaged in farming activities was selected. It was observed that medium sized farmers having 10-20 acre were more in number as compared to small and large farmers. Number of trees was found maximum in large farm lands, ratio of diseased trees was almost similar in all categories with maximum in small farmlands (24.1%). Regarding the future prospects 35% farmer were interested in agroforestry practices 65% were not interested in the promotion of trees due to the non-availability of technical guidance and proper markets. Geographic images of the study site can further help the researchers and policy makers in the promotion of agroforestry.

Keywords: agroforestry trends, adoption, Faisalabad, geographic information system (GIS)

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Authors: Khalid S. Hashim, Andy Shaw, Rafid Alkhaddar, Montserrat Ortoneda Pedrola

Abstract:

A flow column has been innovatively used in the design of a new electrocoagulation reactor (ECR1) that will reduce the temperature of water being treated; where the flow columns work as a radiator for the water being treated. In order to investigate the performance of ECR1 and compare it to that of traditional reactors; 600 mL water samples with an initial temperature of 35 0C were pumped continuously through these reactors for 30 min at current density of 1 mA/cm2. The temperature of water being treated was measured at 5 minutes intervals over a 30 minutes period using a thermometer. Additional experiments were commenced to investigate the effects of initial temperature (15-35 0C), water conductivity (0.15 – 1.2 S) and current density (0.5 -3 mA/cm2) on the performance of ECR1. The results obtained demonstrated that the ECR1, at a current density of 1 mA/cm2 and continuous flow model, reduced water temperature from 35 0C to the vicinity of 28 0C during the first 15 minutes and kept the same level till the end of the treatment time. While, the temperature increased from 28.1 to 29.8 0C and from 29.8 to 31.9 0C in the batch and the traditional continuous flow models respectively. In term of initial temperature, ECR1 maintained the temperature of water being treated within the range of 22 to 28 0C without the need for external cooling system even when the initial temperatures varied over a wide range (15 to 35 0C). The influent water conductivity was found to be a significant variable that affect the temperature. The desirable value of water conductivity is 0.6 S. However, it was found that the water temperature increased rapidly with a higher current density.

Keywords: water temperature, flow column, electrocoagulation

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