96 research outputs found
Type of housing as a factor of self-determination in persons with moderate intellectual disability
Uvod: Prethodna istraživanja su pokazala da je nivo samoodreÄenja osoba sa
intelektualnom ometenoÅ”Äu determinisan razliÄitim Äiniocima. Tip stanovanja
je jedan od znaÄajnih Äinilaca razvoja i praktikovanja te veÅ”tine.
Cilj: Cilj rada je utvrÄivanje razlika u nivou samoodreÄenja izmeÄu osoba sa umerenom
intelektualnom
ometenoÅ”Äu
koje
žive u
razliÄitim
tipovima
stanovanja.
Metode:
Uzorkom
je
obuhvaÄeno
87
odraslih
osoba
sa
umerenom
intelektualnom
ometenoÅ”Äu,
oba
pola,
koji
žive
u
razliÄitim
tipovima
stanovanja:
u
primarnim
porodicama,
institucijama
ili
programu
stanovanja
uz
podrŔku.
Za
prikupljanje
podataka o
nivou
samoodreÄenja
koriÅ”Äena
je
ARC
skala
samoodreÄenja.
Rezultati:
UtvrÄene
su
statistiÄki
znaÄajne
razlike
izmeÄu
ispitanika
koji
žive
u
razliÄitim
tipovima
stanovanja
na
nivou
ukupnog
samoodreÄenja
(F
=
14,500;
p
<
.001)
i
komponenti
samoodreÄenja:
autonomije
(F
=
17,995;
p
<
.001),
samoregulacije
(F
=
8,011;
p
=
.001),
psiholoŔke
osnaženosti
(F
=
15,634;
p
=
.005)
i
samorealizacije
(F
=
5,837;
p
=
.004).
Nivo
samoodreÄenja
osoba
sa
umerenom
intelektualnom
ometenoÅ”Äu
koje
stanuju
u
zajednici
uz
podrŔku
statistiÄki
je
znaÄajno
viŔi
od
nivoa
samoodreÄenja
osoba
koje
stanuju
u
primarnim
porodicama
(p
<
.001)
i
institucijama
(p
=
.004).
Osobe
koje
stanuju
u
institucijama
imaju
viŔi
nivo
samoodreÄenja
od
onih
koje
žive
sa
svojim
porodicama
(p =
.038).
ZakljuÄak:
Stanovanje
u
zajednici
uz
podrŔku
predstavlja
optimalan
ambijent
za
razvoj
veŔtina
samoodreÄenja
odraslih
osoba
sa
umerenom
intelektualnom
ometenoÅ”Äu.
Potrebno
je
intenzivirati
praksu
stanovanja
u
zajednici
uz
podrŔku
za
osobe
sa
umerenom
intelektualnom
ometenoÅ”Äu,
s
obzirom
na
to
da
je
utvrÄen stimulativan uticaj ovog tipa stanovanja na razvoj i praktikovanje ve-
Å”tina samoodreÄenog ponaÅ”anja.Introduction: Previous research has shown that the level of self- determination in
people with intellectual disability is determined by various factors. The type of housing is one
of the important factors in the development and practice of that skill.
Aim: The objective of the paper was to determine the difference in the level of selfdetermination
between persons with moderate intellectual disability who live in different
types of housing.
Methods: The sample included 87 adults with moderate intellectual disability, of
both genders, living in different types of housing: in primary families, institutions, or a
supported housing program. The ARC self-determination scale was used to collect data on
the level of self- determination.
Results: Statistically significant differences were found between respondents living in
different types of housing at the level of total self-determination (F = 14.500; p < .001) and
components of self- determination: autonomy (F = 17.995; p<.001), self-regulation (F = 8.011;
p = .001), psychological empowerment (F = 15.634; p = .005) and self- realization (F = 5.837;
p = .004). The level of self-determination in persons with moderate intellectual disabilities
within the supported community living program was statistically significantly higher than
the level of self-determination in persons living in primary families (p < .001) and institutions
(p = .004). People who lived in institutions had a higher level of self-determination than those
who lived with their families (p = .038).
Conclusion: The supported community living program is an optimal environment for
the development of self-determination in adults with moderate intellectual disabilities.
It is necessary to intensify the practice of supported housing in a community for people
with moderate intellectual disability, considering the determined stimulating effect on the
development and practice of self-determined behavior skills
Influence of different carbon monolith preparation parameters on pesticide adsorption
The capacity of carbon monolith for pesticide removal from water, and the
mechanism of pesticide interaction with carbon surface were examined.
Different carbon monolith samples were obtained by varying the carbonization
and activation parameters. In order to examine the role of surface oxygen
groups in pesticide adsorption, carbon monolith surface was functionalized by
chemical treatment in HNO3, H2O2 and KOH. The surface properties of the
obtained samples were investigated by BET surface area, pore size
distribution and temperature-programmed desorption. Adsorption of pesticides
from aqueous solution onto activated carbon monolith samples was studied by
using five pesticides belonging to different chemical groups (acetamiprid,
dimethoate, nicosulfuron, carbofuran and atrazine). Presented results show
that higher temperature of carbonization and the amount of activating agent
allow obtaining microporous carbon monolith with higher amount of surface
functional groups. Adsorption properties of the activated carbon monolith
were more readily affected by the amount of the surface functional groups
than by specific surface area. Results obtained by carbon monolith
functionalisation showed that Ļ-Ļ interactions were the main force for
adsorption of pesticides with aromatic structure, while acidic groups play an
important role in adsorption of pesticides with no aromatic ring in the
chemical structure
Preparation and Performance of Low Content Carbon Geopolymer
Due to the low CO2 emission of geopolymers compared to Portland cement, interest in their use as binding cement has increased in recent years. The main goal of this research is to relate the green and sustainable characteristics to the good mechanical and chemical properties of fly ashbased geopolymers. For those purposes, samples of different ratios of fly ash (FA) and metakaolin (MK) were prepared. Mineralogical characterization of the geopolymer samples conducted using X-ray powder diffraction (XRD) showed that in the geopolymer synthesis reaction new amorphous phase was formed. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) confirmed characteristic bands of Si-O and O-Si-O groups at 1045 cmā1 . Compressive strength analysis revealed that the optimal ratio of FA and MK is 50:50 and exhibits the highest value, while X-ray photoelectron spectroscopy (XPS) analysis revealed the total reduction of carbon content in the alkali activated geopolymer with optimal stoichiometry 50:50. The results of this research indicates the possibility to obtain a geopolymer material with almost complete absence of carbon, which implies further application as a material with very high environmental potential and zero carbon emission
HEMP FIBERS AGAIN IN SERBIA: OLD FIBERS ā NEW APPLICATIONS
This paper attempts to summarize the historical facts about the
cultivation and use of hemp in the world, and especially in Serbia, with a special
emphasis on the research and new application brought by the renaissance of hemp
production at the end of the 20th century. Hemp (Cannabis Sativa L.) as one of the
oldest cultivated plants represents a renewable and sustainable source of fibers, mainly
for textile production. Due to their specific chemical composition, structure and
properties, such as high specific strength, non-toxic, biocompatible and biodegradable
nature, hemp fibers become ideal candidates for a wide range of applications. Being
lignocellulosic, hemp can be used alone, or as combined with different kinds of polymers
to provide a wide range of useful composites in textiles, construction, automotive
industry, and soil conservation. Also, hemp fibers have proven to be efficient biosorbents
and suitable precursors for the production of low-cost carbon materials for adsorption
applications.U ovom radu su sumirane istorijske Äinjenice o gajenju i upotrebi
konoplje u Srbiji i svetu, sa posebnim osvrtom na istraživanja i nove primene sa
renesansom konoplje krajem 20. veka. Konoplja (Canabis Sativa L) je jedna od
najstarijih gajenih biljaka, i predstavlja obnovljiv i održiv izvor vlakana, uglavnom za
tekstilnu industriju. Zbog svog specifiÄnog hemijskog sastava, strukture i svojstava, kao
Å”to su visoka specifiÄna ÄvrstoÄa, netoksiÄnost, biokompatibilnost i biorazgradivost,
vlakna konoplje imaju visok potencijal za primenu u razliÄitim oblastima. Sama, ili kao
kompozit u kombinaciji sa razliÄitim vrstama polimera, konoplja nalazi primenu u
oblastima tekstila, graÄevinarstva, automobilske industrije, oÄuvanja životne sredine.
TakoÄe, vlakna konoplje su se pokazala kao efikasni biosorbenti i pogodni prekursori za
proizvodnju jeftinih ugljeniÄnih adsorbenata za preÄiÅ”Äavanje vode od organskih i
neorganskih zagaÄujuÄih materija
The effect of starch modification on the dye adsorption efficiency
Researches in the field of nanotechnology indicate the possibility of the development and application
of bionanocomposites based on clay minerals and biopolymers as promising materials for the removal
of pollutants from contaminated water. Therefore, this study is based on an examination of the effect
of intercalation of starch or cationic starch with kaolin clay or diatomaceous earth on the adsorption
properties of the obtained materials for the removal of anionic and cationic dyes from aqueous
solutions. Structural characterization of the obtained materials was performed by Fourier transform
infrared spectroscopy while the morphology of the samples was determined by Scanning electron
microscopy. The removal efficiency of methyl orange and crystal violet dyes was tested in a batch
system, while the dye concentration after the adsorption process was determined by UV-Vis
spectrophotometry. It was found that modification of cationic starch with clay and diatomaceous earth
improved the efficiency for removing crystal violet dye from an aqueous solution
Carbon cryogel as an adsorbent for removal of Cd(II), Zn(II) and Ni(II) ions from water
ZagaÄenje vodenih tokova teÅ”kim metalima je jedan od najakutnijih ekoloÅ”kih
problema danaŔnjice. S obzirom na to da teŔki metali nisu biorazgradivi, oni se akumuliraju
u životnoj sredini i na taj naÄin ulaze u lanac ishrane ljudi i životinja, pa kao veoma toksiÄne
materije, mogu izazivati niz opasnih i Äesto neizleÄivih bolesti. Iz tog razloga, istraživaÄi
godinama u nazad razvijaju nove i usavrÅ”avaju postojeÄe tehnike za preÄiÅ”Äavanje otpadnih
voda od ovih zagaÄujuÄih materija [1]. Za preÄiÅ”Äavanje vode zagaÄene teÅ”kim metalima
mogu se koristiti razliÄite metode: hemijska precipitacija, elektrohemijski tretmani, filtracija,
reverzna osmoza, jonska izmena, membranski procesi, adsorpcija. Jedna od najÄeÅ”Äe
koriÅ”Äenih je adsorpcija, koja zbog moguÄnosti regenerisanja adsorbenta, odgovarajuÄim
desorpcionim procesom, predstavlja veoma efektivnu i ekonomiÄnu metodu. ZahvaljujuÄi
razvijenoj specifiÄnoj povrÅ”ini i poroznosti, kao i prisustvu funkcionalnih grupa na povrÅ”ini,
razliÄiti ugljeniÄni materijali pokazuju visoku efikasnost u uklanjanju teÅ”kih metala iz
vode. Karbon kriogel (CC) predstavlja ugljeniÄni materijal razvijene mezoporoznosti Äije
se adsorpcione karakteristike mogu poboljŔati optimizacijom i kontrolisanjem parametara
dobijanja. U ovom radu je ispitana moguÄnost uklanjanja jona teÅ”kih metala (Cd2+, Ni2+ i
Zn2+) iz vode, koriÅ”Äenjem karbon kriogela i hemijski modifikovanog karbon kriogela.
Prvi korak u sintezi karbon kriogela je polikondenzacija rezorcinola i formaldehida,
u prisustvu natrijum-karbonata kao katalizatora. Organski kriogel pripremljen je solgel tehnologijom uz naknadno suŔenje postupkom zamrzavanja, dok je karbonizacija
organskog kriogela vrŔena u inertnoj atmosferi argona na temperaturi od 800 o
C [2]. U
cilju poboljŔanja adsorpcionih karakteristika karbon kriogela, izvrŔeno je hemijsko
modifikovanje koriÅ”Äenjem 5 M HNO3
. Karakterizacija materijala izvrŔena je merenjem
specifiÄne povrÅ”ine BET metodom, odreÄivanjem taÄke nultog naelektrisanja metodom
masene titracije, kao i odreÄivanjem vrsta funkcionalnih grupa prisutnih na povrÅ”ini
materijala, metodom infracrvene spektroskopije sa Furijeovom transformacijom (FTIR).
Ispitan je uticaj pH vrednosti rastvora, poÄetne koncentracije jona metala u rastvoru, kao i
vremena kontakta na adsorpciju teŔkih metala uzorcima karbon kriogela.Primenjenom hemijskom modifikacijom karbon kriogela ne dolazi do bitnijih
promena u specifiÄnoj povrÅ”ini i poroznosti materijala. S druge strane, ovim postupkom
dolazi do izmene povrÅ”inske hemije materijala, uvoÄenjem novih, i poveÄanjem broja
postojeÄih kiselih povrÅ”inskih grupa, Å”to je pokazano FTIR analizom i smanjenjem
vrednosti taÄke nultog naelektrisanja sa pHPZC = 9,3 na pHPZC = 3,1. Adsorpcija jona teÅ”kih
metala na modifikovanom i nemodifikovanom karbon kriogelu vrŔena je na pH = 6, jer pri
ovoj pH vrednosti materijali pokazuju najveÄi adsorpcioni kapacitet, a ujedno je izborom
ove pH izbegnuta precipitacija hidroksida metala. Izmene u hemiji povrŔine dovode i do
izmena adsorpcionih karakteristika karbon kriogela. Kako povrŔinske grupe predstavljaju
aktivna mesta za adsorpciju jona teÅ”kih metala, poveÄanje koliÄine povrÅ”inskih grupa kod
modifikovanog karbon kriogela dovodi do viÅ”estrukog poveÄanja adsorpcionog kapaciteta
Effect of alkali modification on adsorption efficiency of fly ash
As coal combustion in thermal power plants generates huge amounts of waste such as bottom ash and fly ash, there is a need to find new applications for these materials. One of the ways of its reuse is chemical or thermal modification of the ash in order to obtain new materials, which can be further
used as adsorbents of various pollutants from water. The subject of this research was the alkali modification and alkali activation of fly ash in purpose to increase the adsorption capacity towards heavy metal ions. The success of modification process and characterization of the obtained materials was monitored by Fourier transform infrared spectroscopy, X-ray fluorescence spectroscopy and scanning electron microscopy. The concentration of zinc and cadmium ions after adsorption was determinated by atomic absorption spectroscopy. The kinetics of the adsorption process on the most efficient adsorbent were examined and the experimental data were compared with pseudo-first and pseudo-second order models. The achieved results show a positive effect of alkaline modification of fly ash on adsorption efficiency of both metals, while alkaline activation gives an exceptionally effective adsorbent in the case of zinc
Heavy metals concentration in soils from parks and green areas in Belgrade
The current study included the investigation of several metals and their distribution in urban soils from parks and green areas in the city of Belgrade. The soils were sampled in January and February 2008. The concentrations of Cd, Co, Cu, Pb, Mn and Zn were measured, as well as the pH values and organic matter contents. The obtained results showed that there was a significant level of contamination in some samples, especially with lead, and that it was most probably caused by anthropogenic activities, mostly from traffic. The results were compared with the National legislation and Netherlands standards. Also, the recent results were compared with the data from previous work and it was concluded that there has been a certain increase of the Pb concentration in the past three years. The level of pollution in playground soil was very high and each analyzed sample exceeded the Dutch target value for Cd, Co and Pb
Fly ash modified waste cotton and cotton-polyester yarns for removal of heavy metals from water
Using two types of industrial waste materials (yarns and fly ash), adsorbents for removing heavy
metal ions from water were obtained. To improve the adsorption efficiency of cotton and cottonpolyester yarns, modification using fly ash and sodium alginate as a binder, was applied.
Characterization of materials was performed by Scanning electron microscopy and Fourier transform
infrared spectroscopy, while the concentration of lead and cadmium ions was determined using
atomic absorption spectroscopy. The modification of the material has contributed to an increase in
the adsorption efficiency of lead and cadmium by up to twice in comparis onto the unmodified
materials. It was found that the kinetics of the metal adsorption process can be better described by a
second-order pseudo model. The results showed that by combining two types of industrial waste,
cotton and cotton/polyester yarns and fly ash, highly efficient adsorbents for removing lead and
cadmium from aqueous solutions are obtained
A green adsorbent based on wheat starch for removal of selective organic pollutants from aqueous solutions
The objective of this study was to evaluate the adsorption efficiency of a cationic functionalized wheat starch, obtained with betaine hydrochloride and glycidyl trimethylammonium chloride by an environmentally friendly process without the use of organic solvents. Surface functional groups of samples were characterized by Fourier transform infrared spectroscopy, the morphology of the materials was examined using scanning electron microscopy, the nitrogen content was determined by elemental analysis, while UV-VIS spectroscopy and liquid chromatography-tandem mass spectrometry were used for adsorption investigation. The efficiency of obtained cationic starches to
adsorb the anionic and cationic dyes, as well as selected pharmaceuticals and pesticides was investigated. Adsorption experiments were performed in a batch system to determine the effect of contact time, initial concentration, and pH of the solution on the removal efficiency of crystal violet dye, which was chosen as the model for the detailed study of adsorption. Pseudo-first and pseudosecond order models were used to examine the adsorption kinetic, while Langmuir and Freundlich isotherm models were applied to equilibrium adsorption data. The results showed that environmentally and economically acceptable adsorbents prepared in this study could be effective in removing the examined organic pollutants
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