246 research outputs found
Sex differences of human corpus callosum revealed by polar coordinate system: magnetic resonance imaging study
Background: Evaluation of morphological and size changes related to various pathological conditions of the corpus callosum (CC) requires the data about sex dimorphism of the CC. The purpose of our study is to define potential morphological sex differences of the CC by the use of polar coordinate system as a system of measurements.
Materials and methods: After division of the CC into three equal segments by the use of polar coordinate system, we investigated the length of the hemisphere (A-Aā), the CC size as its midsagittal section area (CCA), the size of its segments (C1, C2, C3), thickness of the thinnest part of the CC (TCC) and the angular coordinate (a angle) of dorsal point of the TCC in a sample of 30 human brains magnetic resonance images (15 males and 15 females, age 20ā50 years).
Results: We found significantly larger CCA, C3 segment and the TCC in males. Statistically significant correlation in both, males and females, was found between parameters of the CCA and of all of its segments (C1, C2, C3), the C1 and C2, the C2 and C3 segments, as well as like as between the C2 and TCC. Sex differences were also in findings of significant correlation between the C1 and C3 segments, between CCA and TCC, and of significant negative correlation between the a angle and A-Aā only in females.
Conclusions: We concluded that the use of polar coordinate system appropriately reflects the anatomical and encephalometric characteristics of human CC
Exploring The Motives Of Religious Travel By Applying The Ahp Method ā The Case Study Of Monastery Vujan (Serbia)
Religious tourism is considered as the oldest form of peopleās travel. Thousands of years ago people travelled miles led by religious motives. Even though pilgrimage is older than most of the other tourism forms, research on the major motives for religious travel still occupies scientific attention. Vujan Monastery represents one of the main riddles among religious tourism researchers in Serbia. After the mysterious healing of Serbian Patriarch Pavle in 1946 who suffered from tuberculosis, this monastery became one of the most famous sacred places for orthodox Christians. The principle aim of this paper is to propose a new way for exploring and ranking the religious motivation using the Analytical Hierarchy Process (AHP) approach. In addition, the study proposes a set of motives ā both religious and secular, which can be applied for exploring the motivations for visiting any sacred site. The method was applied to discover the main motives which drive people to visit Vujan Monastery, get their rankings, as well as their preferences between different types of secular and religious motives. The results indicated a strong preference for religious motives compared to secular motives of visit of this sacred site. On balance, the research provides us with a complete ranking structure, encompassing all analyzed motives of visit which show us a clear picture of the main motivation for visits to Vujan monastery
Supplementary data for article : Panic, V. V.; Seslija, S. I.; Popovic, I. G.; Spasojevic, V. D.; Popovic, A. R.; Nikolic, V. B.; Spasojevic, P. M. Simple One-Pot Synthesis of Fully Biobased Unsaturated Polyester Resins Based on Itaconic Acid. Biomacromolecules 2017, 18 (12), 3881ā3891. https://doi.org/10.1021/acs.biomac.7b00840
Supporting information for: [https://doi.org/10.1021/acs.biomac.7b00840]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2568]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3058
The effect of structural changes on magnetic permeability of amorphous powder Ni80Co20
The structural changes of Ni80Co20 amorphous powder were tested during heating. The alloy was obtained by electrolysis from ammonia solution sulfate of cobalt and nickel on the titanium cathode. The differential scanning calorimetry (DSC) method was used to detect that the crystallization process of powder occurred in two stages with crystallization peaks temperatures of the first stage at 690 K and of the second stage at 790 K. The effect of structural relaxation and crystallization of powder on magnetic properties was predicted by measurement of the relative magnetic permeability change in isothermal and nonisothermal conditions. On the basis of the time change of relative magnetic permeability at a defined temperature in the temperature range of the first and second crystallization peak on the thermogram, the kinetics of crystallization was defined. It was predicted, that in the initial time interval, in the range of the first crystallization peak, the rate of crystallization is determined by the rate of nucleation of the amorphous part of the powder. However, in the second time interval, the crystallization rate is determined by the rate of diffusion. In the range of the second peak, in the beginning the rate of crystal growth is determined by activation energy of the atom pass from smaller to bigger crystal grain. In second time interval, the rate of crystal grain growth is determined by the diffusion rate of atoms to the location of integration into bigger crystal grains. For all processes which determine the rate of crystallization in temperature ranges of both crystallization peaks, the Arrhenius temperature dependence of rate for those processes is obtained. The relative magnetic permeability of crystallized powder at 873 K, is smaller for about 30 % than the relative magnetic permeability of fresh powder at room temperature. However, structurally relaxed powder at 573 K has an about 22 % larger magnetic permeability than the same fresh powder at room temperature
Combination free replacement and pro-rata warranty policy optimization model
Rizik koji prati razvoj proizvoda raste iz dana u dan. Jedan od faktora koji utiÄu na ovaj rizik je garancija proizvoda. Garancija je moÄno marketinÅ”ko oružje za proizvoÄaÄa i istovremeno dobra zaÅ”tita za proizvoÄaÄa i kupca, ali uvek podrazumeva dodatne troÅ”kove za proizvoÄaÄa. Ovi troÅ”kovi zavise od karakteristika pouzdanosti proizvoda i parametara garancije. Ovaj rad se bavi optimizacijom ovih parametara za poznatu raspodelu otkaza proizvoda u cilju smanjivanja troÅ”kova garancije i istovremenog zadržavanja njene promotivne funkcije. Kombinacija garancije besplatne zamene i parcijalne garancije je izabrana kao model, pri Äemu su varirane dužine perioda besplatne zamene i perioda parcijalne garancije, kao i koeficijenti koji definiÅ”u funkciju parcijalnih troÅ”kova. Vrednosti troÅ”kova garancije dobijene su pomoÄu analitiÄkih jednaÄina i simulacije. Dobijeni rezultati su prikazani i razmotreni i izneta su zakljuÄna opažanja.Product development risk increases more and more every day. One of the factors that affect this risk is product warranty. Warranty is a powerful marketing instrument for the manufacturer and a good protection for both the manufacturer and the customer, but it always involves additional costs to the manufacturer. These costs depend on the product reliability and the warranty parameters. This paper deals with the optimization of these parameters for known product failure distribution to reduce the warranty costs to the manufacturer while retaining the promotional function of the warranty. Combination free replacement and pro-rata warranty policy is chosen as a model and the length of free replacement and pro-rata policy periods are varied, as well as the coefficients that define the pro-rata cost function. Warranty costs are obtained by using analytical equations and by simulation. The obtained results are shown and discussed and some concluding remarks are given
Hydrogen Adsorption Process In Nanocrystalline Nuclear Graphite
Kinetics and mechanism of hydrogen adsorption in as-obtained and ground nuclear graphite
Wendelstein 7-X are examined. In the first time interval the adsorption process is determined
by dissociation of the hydrogen molecule, occurring at the outer surface and in open
micropores of nuclear graphite particles. However, in the second time interval, the slowest
step in the hydrogen adsorption is inter-granular and inter-crystallite diffusion in nanopores
of graphite. The X-ray analysis shows, that grinding of as-obtained nuclear graphite results in
finer particles with finer nanocrystals and larger density of opened pores and carbon reactive
sites. The capacity and rate of adsorption increase with comminution of nuclear graphite particles and adsorbed hydrogen does not sub stantially alter the microstructure of nuclear
graphite
Dual responsive hybrid hydrogels for controlled release of local anesthetic
Inteligentni hidrogelovi, kao Å”to su pH osetljivi hidrogelovi na bazi poli(metakrilne kiseline) (PMAA), imaju veliku primenu u ciljanoj dostavi lekova. MeÄutim, slaba mehaniÄka svojstva Äesto ograniÄavaju primenu PMAA. Kako bi se prevaziÅ”lo navedeno ograniÄenje, nanoceluloza (NC) je prvo ekstrakovana iz drvnog otpadnog materijala, a zatim dodata u PMAA, zato Å”to je NC biokompatibilna, netoksiÄna i ima odliÄna mehaniÄka svojstva. Zatim je dodata karboskimetil celuloza (CMC) (celulozni derivat koji se Äesto koristi za kontrolisano otpuÅ”tanje lekova). CMC može da stabilizuje nanoÄestice magnetita (MN) koje su takoÄe dodate. MN mogu znaÄajno da poboljÅ”aju mehaniÄka svojstva hidrogelova i takoÄe poseduju magnetna svojstva zbog Äega imaju primenu za ciljano otpuÅ”tanje lekova. Ovako dobijeni materijal bi mogao da zaÅ”titi lek, dostavi ga do mesta delovanja, kontroliÅ”e brzinu njegovog otpuÅ”tanja i na taj naÄin omoguÄi efikasno dejstvo leka sa smanjenim neželjenim efektima. Lokalni anestetik ā lidokain hidrohlorid (LH) se Äesto u tretmanima injektira Å”to može imati ozbiljne neželjene efekte. Inkapsulacijom LH u hidrogelove na bazi PMAA, NC, CMC i MN (PMNC/MN-L) reÅ”en je navedeni problem. Karakterizacija PMNC/MN-L hidrogelova je izvedena primenom FTIR i SEM spektroskopija i kompresionim testovima, a zatim je analizirano bubrenje hidrogelova i otpuÅ”tanje LH. U ovom radu predstavljen je jedinstveni naÄin āzeleneā sinteze hibridnih hidrogelova osetljivih na spoljne stimulanse unapreÄenih svojstava i njihove primene za kontrolisano otpuÅ”tanje lokalnog anestetika sa smanjenim neželjnim efektima
Risk Model for Integrated Management System
The purpose of this paper is to develop an integrated risk management model for standardized management systems: ISO 9001:2015 for quality management, ISO 14001:2015 for environmental management, ISO/IEC 27001:2013 for information security management, ISO 45001:2018 for Occupational Health and Safety Management, and ISO 22000:2005 for food safety management in order to enable organizations can manage their processes and associated risks versus requirements of each internal and external stakeholder through only one MS instead of several individual MSs defined and implemented in an isolated way according to a specific MSS and hence to decrease the number of resources employed and to enhance the organization performance
Kinetics of heat denaturation of pepsin in a strong acid media
Heat aggregation of pepsin, in a strong acid media; involve the stage of nucleation, and the stage of growth of aggregates. The initial parts of the kinetic curves of aggregation were followed via monitoring the increase of absorbance (A) and were linearized as {dA/dt; t} and {A; t 2 } functions. The slope of these curves is proportional to the product rate constant of reversible denaturation and the rate constant of growth of aggregates. Addition of Al3+ ions display a lag period whose appearance is caused by intramolecular predenaturational changes in the pepsin molecule.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Energy constrained sandpile models
We study two driven dynamical systems with conserved energy. The two automata
contain the basic dynamical rules of the Bak, Tang and Wiesenfeld sandpile
model. In addition a global constraint on the energy contained in the lattice
is imposed. In the limit of an infinitely slow driving of the system, the
conserved energy becomes the only parameter governing the dynamical
behavior of the system. Both models show scale free behavior at a critical
value of the fixed energy. The scaling with respect to the relevant
scaling field points out that the developing of critical correlations is in a
different universality class than self-organized critical sandpiles. Despite
this difference, the activity (avalanche) probability distributions appear to
coincide with the one of the standard self-organized critical sandpile.Comment: 4 pages including 3 figure
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