Multicomponent Modelling Kinetics and Simultaneous Thermal Analysis of Apricot Kernel Shell Pyrolysis

Apricot kernel shells are naturally available source of biomass with potential for conversion to clean energy through a thermo-chemical process such as pyrolysis. To facilitate further process development, an advanced mathematical model which represents the process kinetics is developed and validated on the thermal decomposition studies using simultaneous thermal analysis, over a temperature range of 30-900 °C, at four heating rates of 5, 10, 15 and 20 °C min−1, under argon atmosphere. Model-free analysis and numerically developed methods were utilized for determination of effective activation energies, pre-exponential factors and the fractional contribution. A novel approach is introduced in order to determine actual pseudo-components of studied biomass that are included in its composition. The comparative study of the obtained kinetic results was also presented. The results obtained strongly indicated that the pseudo-component reaction modelling method could be employed to predict the experimental devolatilization rate and biomass composition with a high likelihood of success

Fleet renewal: An approach to achieve sustainable road transport

With more stringent requirements for efficient utilization of energy resources within the transport industry a need for implementation of sustainable development principles has appeared. Such action will be one of competitive advantages in the future. This is especially confirmed within the road transport sector. A methodology implemented in public procurement procedures for fleet renewal regarding the calculation of road vehicles’ operational lifecycle costs has been analyzed in detail in this paper. Afore mentioned calculation comprises the costs for: vehicle ownership, energy, carbon dioxide and pollutants emissions. Implementation of this methodology allows making the choice of energy efficient vehicles and vehicles with notable positive environmental effects. The objective of the research is to assess the influence of specific parameters of vehicle operational lifecycle costs, especially energy costs and estimated vehicle energy consumption, on vehicle choice in the procurement procedure. The case of urban bus fleet in Serbia was analyzed. Their operational lifecycle costs were calculated and differently powered vehicles were assessed. Energy consumption input values were defined. It was proved that defined fleet renewal scenarios could influence unquestionable decrease in energy consumption

Pljevlja lignite carbon emission charateristics

The anthropogenic emission of GHG especially CO has to be limited and reduced due to their impact on global warming and climate change. Combustion of fossil fuels in the energy sector has a dominant share in total GHG emissions. In order to reduce GHG emission, European Union established a scheme for GHG allowance trading within the community, and the implementation of the European Union emission trading scheme, which is a key to GHG reduction in a cost-effective way. An important part of emission trading scheme is prescribed methodology for monitoring, reporting, and verification of the emission of GHG including characterization of the local fuels combusted by the energy sector. This paper presents lignite characteristics from open-pit mine Borovica-Pljevlja, which has highest coal production in Montenegro (>1.2 Mt per year), including evaluation of its carbon emission factor based on the laboratory analysis of 72 coal samples. Testing of the samples included proximate and ultimate analysis, as well as, net calorific value determination. In accordance with the obtained results, linear correlations between net calorific value and combustible matter content, carbon content and combustible matter content, hydrogen content and combustible matter content, carbon content and net calorific value, were established. Finally, the non-linear analytical correlation between carbon emission factor and net calorific value for Pljevlja lignite was proposed, as a base for the precise calculation of CO emission evaluation

Implementation of GIS technologies in assessment and protection of natural values of Tara National Park

Mount Tara is among the most important centers of Balkan and European ecosystem and species biodiversity. It is characterized by diversified and well-maintained communities of old deciduous and mixed coniferous forests (beech/fir/spruce). They represent a unique example of well preserved forests in SE Europe with numerous endemic and relict species of indigenous flora and fauna. The geographical information system (GIS) that we have created has proved an excellent tool for valorization and protection of all natural values and potentials of Tara National Park.Geografski informacioni sistem je: organizovan skup računarskog hardvera softvera, geografskih podataka i kadra, dizajniran da efikasno prikuplja smešta, nadgrađuje, manipuliše, analizira i prikazuje sve forme geografski referencirane informacije. Za ekologe GIS je otvorio nove mogućnosti za istraživanja i aplikaciju sakupljenih informacija. Zbog same kompleksnosti sistema životne sredine mi najčešće nastojimo da ih proučavamo koristeći redukcionistički pristup, fokusirajući ce na male, diskretne pojednostavljene aspekte. Međutim većina problema u životnoj sredini su više faktorijalni i zahtevaju razmatranje širokog spektra izvora informacija pitanja i interesa. Za većinu ekoloških studija potrebne su nam eksplicitnije i kvalifikovanije terenske informacije vezane za faktore koji bi mogli da objasne posmatranu ekosistemsku, faunističku i florističku raznovrsnost u dimenziji prostorne i vremenske distribucije uključujući i podatke o geologiji, klimi, pedologiji, distribuciji i ponašanju istrživanih vrsta. Ovde svoju ulogu pronalaze geografski informacioni sistemi (GIS). Nacionalni park Tara obuhvata najveći deo planine Tare u zapadnoj Srbiji prosečne nadmorske visine 1000-1200 m na 180 km od Beograda. Ukupna površina zaštićenog područja Nacionalnog parka je 19.175 ha, a 37.584 ha predstavlja zaštitnu zonu oko Nacionalnog parka. Pripada opštini Bajina Bašta. Planina Tara predstavlja jednu od vrućih tačaka specijskog i ekosistemskog diverziteta sa 35 različitih šumskih zajednica lišćarskog, mešovito četinarskog tipa, kao i 19 opisanih livadskih zajednica. Mnoge od njih posebno one sa Pančićevom omorikom, imaju reliktan ili endemoreliktan karakter. U tom smislu sasvim je opravdano što se Tara danas našla na listi područja značajnih za očuvanje ptičijeg sveta (IBA) i dnevnih leptira Evrope (PBA), a u toku je njeno uključivanje u međunarodnu listu područja značajnog za očuvanje svetske flore (IPA). Kako se gazdovanje i upravljanje praktično svim prirodnim potencijalima NP Tara, do sada dominantno zasnivalo na principima šumarske tehnologije i inženjeringa ovaj rad ima svoju punu naučnu opravdanost u pokušaju implementacije savremenih naučnih saznanja iz oblasti zaštite biodiverziteta, konzervacione ekologije geografije i prostornog planiranja u mehanizam upravljanja prirodnim nacionalnim resursima. Ovaj tip vrednovanja i zaštite otvara mogućnost primene održivog/usklađenog korišćenja resursa NP Tara. Tokom 2002. i 2003. godine formirane su teme GIS NP Tara koje obuhvataju prirodne (geomorfologija, geologija, pedologija, hidrologija, vegetacija, flora fauna), korišćene (eksploatacija šuma) i veštačke (antropogene) sadržaje (puteve, brane, naselja, turističke sadržaje i granice). Geografski informacioni sistem koji je formiran za NP Taru sa temama koje ga čine da prati okvire sličnih projekata rađenih u Evropi i svetu i jedan je od tipičnih geografskih informacionih sistema (iz oblasti ekologije, zaštite životne sredine, šumarstva, itd), koji sadrži gotovo sve vrste podataka (izuzev satelitskih snimaka) u GIS (rasterske, vektorske, DEM, baza podataka i aerofotogrametrijske snimke).Projekat ministarstv

Systems of Hess-Appel'rot Type and Zhukovskii Property

We start with a review of a class of systems with invariant relations, so called {\it systems of Hess--Appel'rot type} that generalizes the classical Hess--Appel'rot rigid body case. The systems of Hess-Appel'rot type carry an interesting combination of both integrable and non-integrable properties. Further, following integrable line, we study partial reductions and systems having what we call the {\it Zhukovskii property}: these are Hamiltonian systems with invariant relations, such that partially reduced systems are completely integrable. We prove that the Zhukovskii property is a quite general characteristic of systems of Hess-Appel'rote type. The partial reduction neglects the most interesting and challenging part of the dynamics of the systems of Hess-Appel'rot type - the non-integrable part, some analysis of which may be seen as a reconstruction problem. We show that an integrable system, the magnetic pendulum on the oriented Grassmannian $Gr^+(4,2)$ has natural interpretation within Zhukovskii property and it is equivalent to a partial reduction of certain system of Hess-Appel'rot type. We perform a classical and an algebro-geometric integration of the system, as an example of an isoholomorphic system. The paper presents a lot of examples of systems of Hess-Appel'rot type, giving an additional argument in favor of further study of this class of systems.Comment: 42 page

Comparative pyrolysis kinetics of various biomasses based on model-free and DAEM approaches improved with numerical optimization procedure

The pyrolysis process of various types of biomass (agricultural and wood by-products) in non-isothermal conditions using simultaneous thermal analyses (STA) was investigated. Devolatilization kinetics was implemented through combined application of model-free methods and DAEM (distributed activation energy model) using Gaussian distribution functions of activation energies. Results obtained were used in the curve prediction of the rate of mass loss against temperature at various heating rates by numerical optimization. The possible calculation of biomass samples behavior under pyrolytic conditions as the summation of their pseudo-components, hemicelluloses, cellulose, and lignin is also explored. The differences between experimental and calculated data are less than 3.20% offering a quality test of applicability of proposed model on the kinetic studies of a wide range of biomass samples. It seems that the most physically realistic model is the decomposition of biomass in three reactions, depending on the composition of the biomass regarding hemicelluloses, cellulose, and lignin. Kinetic model applied here may serve as a starting point to build more complex models capable of describing the thermal behavior of plant materials during thermochemical processing

Morphometric Analysis of Nonsclerosed Glomeruli Size and Connective Tissue Content during the Aging Process

Number of sclerotic glomeruli increases during the aging process. Consequently, majority of remained nonsclerosed glomeruli become hypertrophic and some of them sclerotic, too. The aim of this study was to quantify the size and connective tissue content of nonsclerosed glomeruli and to evaluate the percentage of hypertrophic ones in examined human cases during the aging. Material was right kidney's tissue of 30 cadavers obtained during routine autopsies. Cadavers were without previously diagnosed kidney disease, diabetes, hypertension, or any other systemic disease. Tissue specimens were routinely prepared for histological and morphometric analysis. Images of the histological slices were analyzed and captured under 400x magnification with digital camera. Further they were morphometrically and statistically analyzed with ImageJ and NCSS-PASS software. Multiple and linear regression of obtained morphometric parameters showed significant increase of glomerular connective tissue area and percentage. Cluster analysis showed the presence of two types of glomeruli. Second type was characterized with significantly larger size, connective tissue content, and significantly lower cellularity, in relation to the first type. Such glomeruli might be considered as hypertrophic. First type of glomeruli was predominant in younger cases, while second type of glomeruli was predominant in cases older than 55 years

Security of wireless keyboards: Threats, vulnerabilities and countermeasures

Introduction/purpose: This paper provides an overview of research on computer system vulnerabilities caused by compromised electromagnetic radiation by wireless keyboards. Wireless devices that use event-triggered communication have been shown to have critical privacy issues due to the inherent leakage associated with radio frequency emissions. Wireless connectivity technology is a source of signal emanation that must be protected in terms of performance and security. Methods: Wireless device vulnerabilities and side-channel attacks are observed, along with electromagnetic emission of radio waves. Results: The findings highlight a specific wireless keyboard's security and encryption flaws. The results of penetration testing reveal vulnerabilities of targeted wireless keyboards in terms of outdated firmware, encryption, wireless reliability, and connection strength. Conclusion: Wireless keyboards have security flaws that disrupt radio communication, giving a malicious user complete access to the computer to which the keyboard is connected. An attacker can steal sensitive data by observing how the system works using compromised electromagnetic emissions

Surface chemistry and structural properties of proton-beam irradiated graphene oxide paper

Graphene oxide (GO) is a promising material for the futuregraphene-based electronics where the surface chemistry and structural properties of GO may play an important role. One of the unique methods with great potentialfor controllable modification of materials’ properties is the ion beam irradiation. In the present study, GO paper was irradiated with 15 keV proton- beam to a fluences from 5×10 16 to 2×1017 ionscm-2 , while Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray photoelectronspectroscopy (XPS) and Raman spectroscopy (RS)were used for the examination of surface chemistry and structural properties of the irradiated material. It was shown that proton beam irradiation leads to a partial reduction of GOwith the preferential removal of the alkoxy and epoxy groups. With the increasing fluence, the oxygen content from the XPS method and the intensity ratioof D and G Raman bandsboth showed decreasing trends. When oxygen content was compared to relative areas of specific functional groups and parameters of Raman peaks an interesting correlation was found that suggest optimal fluences for tuning the surface chemistry and structural properties of GO. The observed effects on surface chemistry and structural propertiescan be ascribed to physical and chemical effectsof ion beam irradiation. The interaction of functional groups with H-atom was investigated using DFT andsemi-empirical (SE) approach. SE calculations revealed that the reduction of the epoxy group appears at H-atom energies below 1.5 eV. This work identifies ion beam irradiation as a preferable technique for selective removal of surface oxygen groups and structural modification of GO where the applied fluence can be used for tuning the degree of change.IX Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 20-21, 2021; Belgrad

Altering Glass Transition of TPD thin Films with UV Light

N,N´-Bis(3-methylphenyl)-N,N’dyphenilbenzidine (TPD) is a hole-transport material used in electroluminescent devices whose glass transition temperature, Tg, depends on the film thickness.[1] For sufficiently thin films (d<30 nm), dewetting of amorphous TPD films deposited on a on fused silica or an ITO substrate occurs even at room temperature.[2] Following a brief report on increased thermal stability of UV irradiated TPD films,[3] we investigated the underlying mechanism responsible for it. From proton NMR and mass spectrometry measurements, coupled with morphology (AFM) and spectroscopy (UV-VIS) studies, we find that photo-excited TPD species react with oxygen in air. This leads to partially oxidized TPD films whose increased thermal stability we ascribe to stronger hydrogen bonding of photo-oxidized TPD species with hydrophilic substrates