Effect of PEG on rheology and stability of nanocrystalline titania hydrosols

Very stable titania hydrosols were prepared by fast hydrolysis of titanium isopropoxide in a large excess of water. XRD patterns show that these sols contain nanocrystals (5–6 nm) of anatase (70%) and brookite (30%). TEM images indicate that these primary particles form aggregates whose mean hydrodynamic diameter, determined by photon correlation spectroscopy, is in the range of 80–90 nm. The flow curves of these colloids, recorded for several volume fractions of nanoparticles, can be perfectly fitted, in the range 0–100 s1, with a power-law model. In this range the behavior is Newtonian but for larger shear rates a shear thinning is observed. The viscosity dependence on particle concentration can be predicted by a Batchelor-type model were the volume fraction of particles is replaced by an effective volume fraction of aggregates, taking into account their fractal dimension. Addition of polyethylene glycol (PEG 2000) induced a marked decrease (more than 50%) of the sol viscosity down to a minimum. This is explained by assuming that PEG adsorbs on the surface of TiO2 particles producing stabilization by steric effects and leading to formation of more compact aggregates. Without PEG the sol viscosity strongly decreases on aging. This effect is not caused by the growth of primary particles. It is rather interpreted as a progressive reorganization of the aggregates toward a more compact packing

Fostering Economic Growth: The Establishment of the Free Economic Zone in Gjakova

Kosova is a developing country which has a huge trade imbalance. In order to decrease the trade imbalance of Kosova, the Ministry of Trade and Industry has decided to establish free economic zones in the cities of Gjakova, Mitrovica and later Prizren. These economic zones were established under the Law Nr. 04/L-159 – on economic zones. This project will be specifically focused on the free economic zone of Gjakova. Gjakova is a city in south-west of Kosovo with a very rich history in industrialization in the times of ex-Yugoslavia. Its previous industrialization and its geographical position have made it possible for Gjakova to be one of the free economic zones in Kosova. The purpose of this zone is to increase the number of foreign investments in Kosova, decrease the trade imbalance of Kosova by increasing exports, increase the number of jobs and income, concentrate businesses in one place only, and increase the competition in domestic and foreign markets. According to research the previous potential in industrialization of Gjakova will not affect the developments in the present day free economic zone. The giant socially owned enterprises that used to exist in Gjakova will not be able to be revitalized because their facilities have suffered a lot of damages and their machines are stolen or completely damaged. An alternative to develop the free economic zone is to use the property of these enterprises for other business activities. This is where the role of the central government and municipal government are intertwined. The municipality of Gjakova does not own any of these enterprises, therefore if any business is interested in using these facilities they should buy them from the Kosovo Privatization Agency or request a long-term lease

Rheological behaviour and spectroscopic investigations of cerium-modified AlO(OH)colloidal suspensions

The rheological behaviour of aqueous suspensions of boehmite (AlO(OH)) modified with different Ce-salts (Ce(NO3)3, CeCl3, Ce(CH3COO)3 and Ce2(SO4)3) was investigated at a fixed Ce/Al molar ratio (0.05). Freshly prepared boehmite suspensions were near-Newtonian and time-independent. A shear-sensitive thixotropic network developed when Ce-salts with monovalent anions were introduced in the nanoparticle sols. The extent of particle aggregation dramatically increased with ageing for Ce(NO3)3 and CeCl3 whereas an equilibrium value was reached with Ce(CH3COO)3. The addition of Ce2(SO4)3 with divalent anions involved no thixotropy but rather a sudden phase separation. The combined data set of IRTF and DRIFT spectra indicated that free View the MathML source anions of peptized boehmite adsorb on the nanoparticle surface by H-bond. The introduction of Ce-salts in the boehmite sol led to the coordination between Ce3+ ions and View the MathML source anions adsorbed on boehmite i.e. to [Ce(NO3)4(H2O)x]− complex. Such coordination led to a thixotropic behaviour which was lower with Ce(NO3)3 compared to CeCl3 and Ce(CH3COO)3. In contrast, Ce2(SO4)3 formed insoluble complexes with dissolved aluminium species. The formation of H-bonded surface nitrate complexes was found to play a decisive role on the particle–particle interactions and consequently on the rheological behaviour of the sols

An efficient route to aqueous phase synthesis of nanocrystalline γ-Al2O3 with high porosity: From stable boehmite colloids to large pore mesoporous alumina

In this paper we emphasise the important role of Pluronic F127 on the porosity of mesoporous alumina prepared from boehmite colloids. By focusing on the F127/boehmite interactions we show how the concepts of interface science may help to predict and improve the textural characteristics of mesoporous alumina. By varying the synthetic parameters, in particular the copolymer content, we show that the porosity of c-Al2O3 can be enhanced by 400% and the average pore diameter can be expanded from 5 to 14 nm. These results are discussed in terms of interactions between the Pluronic F127 and boehmite colloids, and are correlated to the critical micelle concentration (CMC) of the copolymer. The textural characteristics of the mesoporous alumina can be further improved either by introducing hydrocarbons in the preformed boehmite/copolymer sols or by concentrating the sols. In comparison with as-synthesised alumina, those prepared with F127 showed improved thermal stability. Furthermore, boehmite/copolymer sols were stable for all surfactant concentrations investigated and can give high quality coatings suitable for catalytic applications

Mistrivsel i kroppsøvingsfaget - en kvalitativ undersøkelse fra barneskolen

Sammenderag. Denne oppgaven handler om mistrivsel blant elever i kroppsøvingsfaget. Kroppsøving er et fag som generelt er godt likt av elevene, men nyere rapporter forteller at opptil 30 % av elever enten ikke liker eller hater faget (Borgen & Leirhaug, 2012). Studiens formål var å undersøke hvorfor elever opplever kroppsøving som vanskelig og problematisk, og se på hvilken betydning de tre grunnleggende psykologiske behovene fra «Self-Determination Theory», utviklet av Deci og Ryan (1985), har å si for elevenes trivsel. Videre så jeg på hvilke tiltak som bør settes i gang fra kroppsøvingslærere. Studien baserer seg på en kvalitativ tilnærming der 5 elever på 5.trinn ved to barneskoler gjennomførte et spørreskjema, og deltok i et kvalitativt forskningsintervju. Studiens teorigrunnlag baserer seg på Deci & Ryan (1985) sin Selvbestemmelsesteori, samt positivt læringsmiljø. Funn fra undersøkelsen viste at tilhørighets- og autonomibehovet har størst betydning for elevenes trivsel, deltakelse og motivasjon i faget. Overraskende var kompetanse det psykologiske behovet som syntes å ha minst betydning for trivselen og motivasjonen til elevene i denne undersøkelsen. Det kan tenkes at elevene ikke er blitt kjent med læringsmålene, og anser ikke faget som et læringsfag. Et annet interessant funn var at flere av informantene var regelmessig fysisk aktive på fritiden, der fire av de fem deltar i organisert aktivitet. Videre kom det frem at mangel på autonomi var en viktig årsak til at informantene opplever kroppsøving som problematisk, sett at tilhørighetsbehovet ble nevnt som viktigst. Det tyder på at tilrettelegging av kroppsøvingsundervisningen spiller en sentral rolle i elevenes opplevelse av faget. Andre faktorer som kunne ha en innvirkning av elevenes trivsel og deltakelse i kroppsøvingsundervisningen var tidligere deltakelse med fysisk aktivitet på fritiden og psykologisk læringsmiljø. Disse forholdene anses ikke å være isolerte, ettersom de virket å ha en sammenheng på hverandre. Nøkkelord: mistrivsel, trivsel, kroppsøving, selvbestemmelsesteori, positivt læringsklim

Nada puedo sentir… solo el vacío me acompaña

La cotidianeidad que presentan dos hermanos con patología orgánica terminal, el déficit de simbolización, la dinámica familiar atravesada por esas circunstancias y el encuentro con los aprendizajes escolares son el escenario de las reflexiones que enuncia el trabajo. El informe de la docente domiciliaria es referente para desarrollar la teoría a partir de la génesis del yo, la organización corporal y las pulsiones de vida y muerte. El desvalimiento que padecen los niños por una complejidad de combinaciones conlleva a una desmezcla pulsional, al arrasamiento subjetivo traducido en un avance de la pulsión de muerte no sólo desde lo orgánico sino desde lo simbólico imposibilitando los aprendizajes escolares

Nursing Care during ERCP

Introduction: Endoscopic retrograde cholangio pancreatography (ERCP) is an endoscopic procedure that allows a detailed examination and diagnose of diseases of the bile ducts and the pancreatic ducts. Abroad, this procedure is considered a routine one, whereas in our country, falling short of specialized personnel, facilities and environments it is used little or not at all. The ERCP nurse should be specialized and should perform all the duties that a nurse performs in a operation room. Objective: Since in the “Xhaferr Kongoli” hospital in Elbasan was inaugurated the endoscopic department which includes ERCP the objective of this theme is emphasizing the role of ERCP and the performance of the nurse during it. Methodology: 14 clinical cases which were diagnosed and treated with ERCP were taken into study. 6 were pancreatic illness cases and 8 were bile ducts illness cases. For the patients with pancreatic illnesses ERCP was used in 100% of the cases for diagnosis and in 83, 33% of the cases for treatment. In bile ducts illnesses ERCP was used in 87,5% of cased for diagnosis and in 75% of cases for treatment. Complications were observed in 33, 33% of cases in the first group and in 37,5% of cases in the second group. The complications which were manifested during the procedure included the decrease of TA, respiratory depression, throat and abdominal pains which were quickly normalized with the intervention of the medical team. Conclusions: ERCP is a mini-invasive procedure which creates the possibility of resolving problems which before required the execution of more invasive procedures that couldn’t resolve permanently the problem of the patient. It can also be used as a palliative procedure in case of non-operable tumors improving much the life of the patient. The role of the nurse during ERCP involves not only the care during and after the procedure, but also involves informing the patient about the preparations he should make and the complications that can occur during it. The nurse of ERCP serves as an intermediate between the doctor and the patient and is the advocate of the latest.Keywords: ERCP, radiology room, pancreatic diseases, etc