Search results

1

Effect of Complexing Agent on the Structural, Optical and Electrical Properties of Polycrystalline Indium Sulfide Thin Films Deposited by Chemical Bath Deposition

100%

Göde F., Kariper İ., Güneri E., Ünlü S.

Acta Physica Polonica A

|

2017

|

vol. 132

|

issue 3

527-530

EN

Indium sulfide (β-In₂S₃) thin films are synthesized by chemical bath deposition method using three different complexing agent volumes, triethanolamine (TEA) (0.30, 0.45, and 0.60 ml). The effect of complexing agent on the structural, morphological, optical and electrical properties of chemically deposited indium sulfide (β-In₂S₃) thin films have been investigated in this work. The characterization of the present films is carried out using X-ray diffraction, scanning electron microscopy, UV-vis spectroscopy and electrical measurements. The structure of the films is polycrystalline with a cubic phase of β-In₂S₃. Firstly, the band gap of the film decreases from 3.74 eV to 3.15 eV by adding 0.30 ml TEA. Then, it increases to 3.79 eV with increasing TEA. Nevertheless, previously, the refractive index of the films increases from 2.13 to 2.67 for the 0.30 mL TEA and then it decreases to the value of 2.11 with increasing TEA. Extinction coefficient, real and dielectric constant of the films are calculated using the absorption and transmittance spectra. Firstly, the electrical resistivity of the films decreases from 3.46×10⁸ Ω cm to 1.33×10⁷ Ω cm by adding 0.30 ml TEA. Then, it increases to the value of 2.16×10⁹ Ω cm with increasing TEA. Eventually, the more conductive film with worm-like morphology detected from the scanning electron microscopy is synthesized using 0.30 ml TEA. These results show that complexing agent has an important effect on the structural, morphological, optical and electrical properties of the deposited films.

2

Morphological Evaluation of Variously Intercalated Pre-baked Clay

100%

Ullah H., Imtiaz A.

Polish Journal of Chemical Technology

|

2014

|

vol. 16

|

issue 2

5-11

EN

The use of porous materials is enjoying tremendous popularity and attention of the advance scientific communities due to their excellent adsorptive and catalytic activities. Clays are one of the most important candidates in the porous community which shows the above mentioned activities after modifing with a different intercalating agent. The paper is focused on the infiuence of some inorganic intercalating agents (NaOH) on the morphology of the variously intercalated clay samples. The alkali metal was used as the inorganic intercalating agent. The effect of intercalation temperature, intercalation agent concentration and intercalation time on the pre-baked clay morphology were also part of the study. Scanning electron microscopy (SEM) study was performed to evaluate the morphological changes of the resultant intercalates. Different morphological properties were improved significantly in the case of the inorganically modified clay samples. Thus, such intercalations are suggested to be effective if the clays under study are to be used for different industrial process at elevated conditions.

3

Method to obtain carbon nano-onions by pyrolisys of propane

100%

Garcia-Martin T., Rincon-Arevalo P., Campos-Martin G.

Open Physics

|

2013

|

vol. 11

|

issue 11

1548-1558

EN

We present a new and simple method for carbon nano-onions (CNOs) production which is based on the pyrolysis of Propane. CNOs are originated in a laminar premixed Propane/Oxygen flame of approximately 1.8 of stoichiometric coefficient. The stream of gasses resulting from the combustion drives the carbon particles towards the aluminium surface on which nano-onions are deposited and collected. The structure and size of the deposited carbon onion on the metal wall are characterized by High Resolution Transmission Electron Microscopy technique (HRTEM). The experimental images show the presence of two different types of CNOs. The first particles have diameters in the range of 18-25 nm and the second ones around 10 nm.

4

Cross-sectional study of adenoidal biofilms in a paediatric population and its clinical implications

88%

Subtil J., Bajanca-Lavado M. P., Rodrigues J., Duarte A., Reis L., Nogueira I., Jordao L.

Otolaryngologia Polska

|

2019

|

vol. 73(1)

22-28

EN

INTRODUCTION: Adenoids are nasopharyngeal lymphoid tissue with a relevant role in host defence against infection of upper respiratory tract. Nevertheless, adenoids are also a reservoir of microorganisms that can cause infections of upper respiratory tract and otitis particularly in children. OBJECTIVE: Evaluate and compare the association between biofilm assembly on adenoids and the incidence of recurrent infections in a paediatric population submitted to adenoidectomy by either infectious or non-infectious indication. METHODS: Scanning electron microscopy was used to assess biofilms on adenoid surface; biofilm assembly in vitro was monitored by crystal violet assay; antibiotic susceptibility was assessed following EUCAST guidelines; Hinfluenzae capsular typing was performed by PCR. RESULTS: Biofilms were present in 27.4% of adenoid samples and no statistical difference was found between infectious and non-infectious groups. In vitro, the most clinically relevant bacteria, H.influenzae, S.aureus, S.pyogenes, S.pneumoniae and M.catarrhalis, were mostly moderate biofilm assemblers (71.7%). 55.3% of these bacteria were intermediate/resistant to at least one of the tested antibiotics. No association was found between the ability to assemble biofilms in vitro and the presence of biofilms on adenoids nor antibiotic resistance. All H.influenzae were characterized as non-typeable. CONCLUSION: The presence of biofilms on adenoid surface was independent from clinical sample background. Bacterial ability to assemble biofilms in vitro cannot be used to predict biofilm assembly in vivo. The lack of correlation between biofilm formation and infectious respiratory diseases found contributes to question the relevance of biofilms on the pathogenesis of infectious diseases.

5

Prospective observational study of adenoidal biofilms in a paediatric population and its clinical implications

88%

Subtil J., Bajanca-Lavado M. P., Rodrigues J., Duarte A., Reis L., Nogueira I., Jordao L.

Polish Journal of Otolaryngology

|

2019

|

vol. 73

|

issue 1

22-28

EN

INTRODUCTION: Adenoids are nasopharyngeal lymphoid tissue with a relevant role in host defence against infection of upper respiratory tract. Nevertheless, adenoids are also a reservoir of microorganisms that can cause infections of upper respiratory tract and otitis particularly in children. OBJECTIVE: Evaluate and compare the association between biofilm assembly on adenoids and the incidence of recurrent infections in a paediatric population submitted to adenoidectomy by either infectious or non-infectious indication. METHODS: Scanning electron microscopy was used to assess biofilms on adenoid surface; biofilm assembly in vitro was monitored by crystal violet assay; antibiotic susceptibility was assessed following EUCAST guidelines; Hinfluenzae capsular typing was performed by PCR. RESULTS: Biofilms were present in 27.4% of adenoid samples and no statistical difference was found between infectious and non-infectious groups. In vitro, the most clinically relevant bacteria, H.influenzae, S.aureus, S.pyogenes, S.pneumoniae and M.catarrhalis, were mostly moderate biofilm assemblers (71.7%). 55.3% of these bacteria were intermediate/resistant to at least one of the tested antibiotics. No association was found between the ability to assemble biofilms in vitro and the presence of biofilms on adenoids nor antibiotic resistance. All H.influenzae were characterized as non-typeable. CONCLUSION: The presence of biofilms on adenoid surface was independent from clinical sample background. Bacterial ability to assemble biofilms in vitro cannot be used to predict biofilm assembly in vivo. The lack of correlation between biofilm formation and infectious respiratory diseases found contributes to question the relevance of biofilms on the pathogenesis of infectious diseases.

6

Application of selected diffractive and microscopic methods to evaluate the physical state of drug and morphology of microspheres obtained by spray drying of furosemide with Eudragit L30 D-55.

75%

Ostróżka-Cieślik A., Sarecka-Hujar B., Krzykawski T., Karcz J., Banyś A., Jankowski A.

Acta Poloniae Pharmaceutica - Drug Research

|

2018

|

vol. 75

|

issue 3

EN

In pharmaceutical technology, the analysis of physicochemical properties of raw materials, intermediates and products is part of quality control testing at each stage of designing formulations and in the routine evaluation of the final product. The aim of the study was to analyse the physical state of drug and the morphology of microspheres obtained by spray drying, where furosemide was incorporated in the polymeric matrix of Eudragit L30 D-55. The following optimal parameters of the spray drying process were established: aspirator capacity of 80%, T.in: 140 ° C, pump capacity: 10%. The laser diffraction method was used to analyse the size distribution of microspheres in the following furosemide-Eudragit L30 D-55 systems: 1:1, 1:3, 1:5. X-ray powder diffraction was applied to compare the degrees of crystallinity of the final product and the starting material. Furosemide has crystal structure both before and after spray drying, it occurs in the polymorphic forms (form I crystals). No reflection from the crystalline phase has been found on the diffraction pattern of Eudragit. This is an amorphous substance.

7

Chemical stability of plasmon-active silver tips for tip-enhanced Raman spectroscopy

75%

Kalbacova J., Rodriguez R. D., Desale V., Schneider M., Amin I., Jordan R., Zahn D. R. T.

Nanospectroscopy

|

2014

|

vol. 1

|

issue 1

EN

Silver nanostructures are used in tip- and surface-enhanced Raman spectroscopy due to their high electric field enhancement over almost the entire visible spectral range. However, the low chemical stability of silver, compared to other noble metals, promotes silver sulfide and sulfate formation which decreases its plasmonic activity. This is why silver tips are usually prepared on the same day of the experiments or are disregarded in favour of gold that is chemically more stable. Since silver degradation cannot be avoided, we hypothesized that a protection layer may be able to minimize or control degradation. In this contribution, we report the successful preparation of 4-biphenylthiol and 4’-nitro-4-biphenylthiol self-assembled monolayers on silver tips in order to protect them against tarnishing and to investigate the effect on the life-time of the plasmonic activity. The electrochemically etched wire surface was probed via Raman spectroscopy and scanning electron microscopy. The best long term stability and resistance against corrosion was shown by a monolayer of 4-biphenylthiol formed from dimethylformamide which did not display any degradation of the metallic tip during the observed period. Here, we demonstrate an easy and straightforward approach towards increasing the chemical stability of silver TERS-active probes.

8

Free of Volatile Organic Compounds Protection against Moisture in Building Materials/Zabezpieczenia Przegród Budowlanych Przed Wilgocią Wolne Od Lotnych Związków Organicznych

51%

Suchorab Z., Barnat-Hunek D., Smarzewski P., Pavlík Z., Černý R.

Ecological Chemistry and Engineering S

|

2014

|

vol. 21

|

issue 3

401-411

EN

The article presents information about moisture protection of building materials. The discussed parameters determining the efficiency of the water protection are material porosity, water absorptivity and surface condition of building materials. Moreover the ecological aspect of hydrophobic VOC-free preparations available on the market has been underlined. The first part of the article is a description of moisture problem in the building envelopes and the possibilities of its prevention. The special attention is put on the electric methods of moisture estimation with a special emphasis on the Time Domain Reflectometry (TDR) method. The second part of the article is devoted an experiment of model red-brick walls exhibited on capillary uptake process. For the experiment three model red-brick walls were built and prepared for water uptake process. The experiment was monitored by the capacitive and surface TDR probes thanks to which the necessity of sampling and material destruction could be avoided. Conducted experiments show the progress of water uptake phenomenon in the model walls which differ in type of protection against moisture and prove the potential of the non-invasive measurements using the surface TDR probes. Basic physical parameters of the applied bricks were determined together with the reflectometric measurements. Furthermore, Scanning Electron Microscopy (SEM) was used to analyze the hydrophobic layer continuity.

PL

W artykule przedstawiono parametry materiałów budowlanych, które wpływają na skuteczność stosowania preparatów hydrofobowych. Należą do nich porowatość, nasiąkliwość i stan powierzchni. Podkreślono również ekologiczne aspekty stosowania dostępnych na rynku budowlanym hydrofobowych preparatów wolnych od lotnych związków organicznych. Pierwsza część pracy jest omówieniem problemów wilgotnościowych w przegrodach budowlanych. Duży nacisk położono na elektryczne techniki detekcji wilgoci ze szczególnym uwzględnieniem metody TDR. Druga część ma charakter eksperymentalny. W celu zbadania zjawiska podciągania kapilarnego przygotowano trzy modelowe ścianki z cegły ceramicznej pełnej. Omawiany proces był monitorowany za pomocą czujników pojemnościowych oraz powierzchniowych sond TDR. Uzyskane wyniki pozwalają na śledzenie procesu podciągania kapilarnego w modelowych ściankach z cegły ceramicznej różniących się od siebie rodzajem zastosowanego preparatu hydrofobowego i potwierdzają możliwości sondy powierzchniowej TDR w pomiarach wilgotnościowych murów. Równolegle do badań za pomocą technik elektrycznych wyznaczono podstawowe parametry fizyczne cegły wykorzystanej do wymurowania ścianek, wykonano również zdjęcia za pomocą skaningowego mikroskopu elektronowego (SEM) w celu przeanalizowania ciągłości warstwy hydrofobowej.

Refine search results

Effect of Complexing Agent on the Structural, Optical and Electrical Properties of Polycrystalline Indium Sulfide Thin Films Deposited by Chemical Bath Deposition

Morphological Evaluation of Variously Intercalated Pre-baked Clay

Method to obtain carbon nano-onions by pyrolisys of propane

Cross-sectional study of adenoidal biofilms in a paediatric population and its clinical implications

Prospective observational study of adenoidal biofilms in a paediatric population and its clinical implications

Application of selected diffractive and microscopic methods to evaluate the physical state of drug and morphology of microspheres obtained by spray drying of furosemide with Eudragit L30 D-55.

Chemical stability of plasmon-active silver tips for tip-enhanced Raman spectroscopy

Free of Volatile Organic Compounds Protection against Moisture in Building Materials/Zabezpieczenia Przegród Budowlanych Przed Wilgocią Wolne Od Lotnych Związków Organicznych