93 research outputs found

    Remediation of CO2CO_2 in Boudouard’s reaction as an example of reversible chemical reaction

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    One of the fundamental elements of a scientist's work is the ability to lead observations of the phenomena that surround us and based on them making conclusions. These observations are conducted within the so-called scientific experiments. Lessons learned based on the results obtained in experiments allow researchers to better understand the essence of the phenomena occurring in the world around us. Drawing conclusions is not always easy. In order to achieve this skill, we must possess a well-established knowledge in the field of the phenomenon that interests us. The most striking example of how important skills are observation and drawing proper conclusions is the phenomenon of global climate warming. The main parameter influencing temperatures registered on Earth is the concentration of greenhouse gases in the atmosphere, and especially carbon dioxide created from combustion processes. A significant role in studies of the reduction of CO2 emissions plays chemists. To be sure that conducted by them experiments are optimally designed, it is necessary to ensure them with proper education already at the secondary school level. The main aim of this article was to conduct the study in order to explain chemical issues that create the greatest cognitive difficulties among students. The second aim of the article was to propose a chemical experiment to students that would allow them to find out more about the phenomena governing in the area of problematic issues. The proposed experiment is based on the concept of solubility equilibrium. Results of preliminary tests that have been carried out after applying this experiment on a small group of students, indicated their better understanding of the studied subject

    Thermal properties of [Cr(NH3)6](BF4)3[Cr(NH_3)_6](BF_4)_3 studied by adiabatic and relaxation calorimetry

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    Four (solid–solid) phase transitions were detected in the temperature range of (9 to 300) K in polycrystalline [Cr(NH3)6](BF4)3 at TC1 = 240.7 K, TC2 = 108.0 K, TC3 = 91.9 K, and TC4 = 61.3 K by adiabatic calorimetry. The measurements by relaxation calorimetry were followed on lowering temperature from 20 K down to 0.35 K under six different external magnetic field values (9, 7, 5, 3, 1 and 0) T. For non-zero values of applied magnetic field well-defined Schottky anomaly appears. Magnetic heat capacity was calculated assuming the zero-field splitting for the decoupled Cr(III) ions. There is no discrepancy between the observed and calculated values. Isothermal magnetization curve recorded up to 5 T was measured at temperature of 1.8 K

    Comparison of the dielectric properties of Ecoflex® with L,D-poly(lactic acid) or polycaprolactone in the presence of SWCN or 5CB

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    The main goal of this paper was to study the dielectric properties of hybrid binary and ternary composites based on biodegradable polymer Ecoflex®, single walled carbon nanotubes (SWCN), and liquid crystalline 4′-pentyl-4-biphenylcarbonitrile (5CB) compound. The obtained results were compared with other created analogically to Ecoflex®, hybrid layers based on biodegradable polymers such as L,D-polylactide (L,D-PLA) and polycaprolactone (PCL). Frequency domain dielectric spectroscopy (FDDS) results were analyzed taking into consideration the amount of SWCN, frequency, and temperature. For pure Ecoflex®, two relaxation processes (α and β) were identified. It was shown that the SWCN admixture (in the weight ratio 10:0.01) did not change the properties of the Ecoflex® layer, while in the case of PCL and L,D-PLA, the layers became conductive. The dielectric constant increased with an increase in the content of SWCN in the Ecoflex® matrix and the conductive behavior was not visible, even for the greatest concentration (10:0.06 weight ratio). In the case of the Ecoflex® polymer matrix, the conduction relaxation process at a frequency ca. several kilohertz appeared and became stronger with an increase in the SWCN admixture in the matrix. Addition of oleic acid to the polymer matrix had a smaller effect on the increase in the dielectric response than the addition of liquid crystal 5CB. Fourier transform infrared (FTIR) results revealed that the molecular structure and chemical character of the Ecoflex® and PCL matrixes remained unchanged upon the addition of SWCN or 5CB in a weight ratio of 10:0.01 and 10:1, respectively, while molecular interactions appeared between L,D-PLA and 5CB. Moreover, adding oleic acid to pure Ecoflex® as well as the binary and ternary hybrid layers with SWCN and/or 5CB in a weight ratio of Ecoflex®:oleic acid equal to 10:0.3 did not have an influence on the chemical bonding of these materials

    Występowanie chorób autoimmunologicznych u pacjentów z późno ujawniającą się cukrzycą autoimmunologiczną u osób dorosłych — związek z genotypem HLA

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      Introduction: Latent autoimmune diabetes in adults (LADA) is a slow-developing form of autoimmune diabetes, characterised by the presence of type 1 diabetes-associated autoantibody and presentation at diagnosis similar to patients with type 2 diabetes. The aim of this study was to determine the prevalence of auto-antibodies related to endocrine autoimmune diseases in patients with LADA and to assess their association with HLA genotype. Material and methods: We evaluated the presence of anti-thyroglobulin (ATG), anti-thyroid peroxidase (ATPO), anti-tissue transglutaminase IgA (ATTA), and anti 21 hydroxylase (A21H) in 70 patients with LADA, 69 with Type 2 diabetes, and in 50 healthy controls HLA genotype was assed in subpopulation of sluclied subjects. Results: The presence of ATPO (28.6 vs. 10%); ATG (28.6 vs. 14%) was higher in patients with LADA in comparison to healthy controls and ATPO in comparison to patients with type 2 diabetes (38.6 vs. 17.4 %). In patients with LADA the presence of autoimmune thyroid autoantibodies was associated with newly diagnosed subclinical hypothyroidism; almost 7% of patients presented with high TSH. The presence of A21H (2.86 vs. 5.8 vs. 6.1%) and ATTA (2.86 vs. 4.3 vs. 6.0%) was not different between groups. Patients with high TSH level were positive for DQA1*0301 and DRB1*04 HLA genotype: DQB1*0201 and DQB1*02 were higher in patients positive for ATTA. Conclusions: Patients with LADA have higher prevalence of thyroid autoimmune diseases. In patients with LADA similarly to type 1 genotype DQA1*0301 seems to CONFER susceptibility to thyroid autoimmunity, and DQB1*0201 to celiac disease. (Endokrynol Pol 2016; 67 (2): 197–201)  Wstęp: Późno ujawniająca się cukrzyca autoimmunologiczną u osób dorosłych cechuje się obecnością przeciwciał skierowanych przeciwko antygenom wysp trzustkowych u pacjentów z kliniczną prezentacją cukrzycy typu 2. Celem pracy była ocena występowania chorób autoimmunologicznych u pacjentów z cukrzycą LADA oraz ocena związku z genotypem HLA. Materiał i metody: W obecnej pracy oceniono występowanie przeciwciał przeciwko-tyreoglobulinie (ATG), przeciwko peroksydazie tarczycowej (ATPO), przeciwko transglutaminazie tkankowej IgA (ATTA) oraz przeciwko 21 hydroksylazie (A21H) u 70 pacjentów z cukrzycą LADA, 69 z cukrzycą typu 2 oraz 50 osób z grupy kontrolnej oraz genotyp HLA. Wyniki: Częstość występowania przeciwciał ATPO (28,6 vs. 10%), ATG (28,6 vs. 14%) była wyższa w grupie pacjentów z cukrzycą typu LADA w porównaniu do grupy kontrolnej oraz ATPO (38,6 vs. 17,4%) w porównaniu z pacjentami z cukrzycą typu 2. W grupie pacjentów z cukrzycą typu LADA istotnie cześciej stwierdzono obecność przeciwciał ATPO oraz ATG, którym towarzyszyly nowowykryte zaburzenia kliniczne funkcji tarczycy. Częstość występowania przeciwciał przeciwko 21 OH hydroksylazie (2,86 vs. 5,8 vs. 6,1%) oraz przeciwko transglutaminazie w klasie IgA (2,86 vs. 4,3 vs. 6,0%) nie różniła się pomiędzy badanymi grupami. Genotyp HLA DQA1*0301 występował częściej u pacjentów z autoimmunologiczną niedoczynnością tarczycy, nastomiast DQB1*0201 u pacjentów z przeciwciałami ATTA będącymi markerem choroby trzewnej. Wnioski: U pacjentów z cukrzycą LADA częściej występują przeciwciała skierowane przeciwko antygenom tarczycy współistniejące z subliniczną niedoczynością tarczycy. (Endokrynol Pol 2016; 67 (2): 197–201)

    Characteristics of plastic waste processing in the modern recycling plant operating in Poland

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    Although Poland is one of the leading recipients of the waste stream in the European Union (EU), it is at the same time below the average in terms of efficiency of their use/utilization. The adopted technological solutions cause waste processing rates to be relatively low in Poland. As a result, the report of the Early Warning and Response System (EWRS) of the EU indicated Poland as one of the 14 countries of the EU which are at risk in terms of possibility of achieving 50% recycling of waste. This article discusses the implemented technological solutions, and shows the profitability of the investment and the values of the process heat demand both for extractor and reactor. The experimental part analyzed the composition of the input and output of the process and compared it to the required fuel specifications. Attention was drawn to the need to improve the recycling process in order to increase the quality of manufactured fuel components. As potential ways of solving the problem of low fuel quality, cleaning the sorted reaction mass from solid particles and extending the technological line with a distillation column have been proposed. The recommended direction of improvement of the technology is also the optimization of the process of the reactor’s purification and removal of contaminants

    Antidepressants in epilepsy

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    People with epilepsy (PWE) frequently suffer from comorbid mood and anxiety disorders. Depression is one of the major psychiatric comorbidities having a negative impact on the quality of life in people with epilepsy. A review of the literature indicates that the majority of antidepressant-related seizures have been associated with either ultra-high doses or overdosing and, generally, the risk of antidepressant-associated seizures is low. Correspondingly, there is some evidence indicating that antidepressants of most widely used groups may additionally lower the risk of triggering seizures. Four antidepressants are not recommended for patients with epilepsy, i.e.: amoxapine, bupropion, clomipramine and maprotiline. Clinicians applying first line of depression treatment in patients with epilepsy should consider use of SSRIs or SNRIs, particularly sertraline, citalopram, mirtazapine, reboxetine, paroxetine, fluoxetine, escitalopram, fluvoxamine, venlafaxine, duloxetine. Implementation of anticonvulsive drugs in depressed patients should include valproate, carbamazepine, lamotrigine, gabapentin, pregabalin. The paper reviews the evidence for the clinical use of antidepressants in PWE

    Modifications of EHPDB physical properties through doping with Fe2O3Fe_2O_3 nanoparticles (part II)

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    The aim of our study was to analyze the influence of various concentrations of γ-Fe(2)O(3) nanoparticles on the physical properties of the liquid crystalline ferroelectric SmC* phase, as well as to check the effect of introducing nanoparticles in the LC matrix on their properties in the prepared five nanocomposites. UV-vis spectroscopy showed that the admixture reduced the absorption of nanocomposites in the UV range, additional absorption bands appeared, and all nanocomposites were transparent in the range of 500–850 nm. The molecular dynamics in particular phases of the nanocomposites were investigated by the dielectric spectroscopy method, and it was found that nanoparticles caused a significant increase in the dielectric constant at low frequencies, a strong modification of the dielectric processes in the SmC* phase, and the emergence of new relaxation processes for the highest dopant concentrations. SQUID magnetometry allowed us to determine the magnetic nature of the nanoparticles used, and to show that the blocked state of nanoparticles was preserved in nanocomposites (hysteresis loops were also registered in the ferroelectric SmC* phase). The dependence of the coercive field on the admixture concentration and the widening of the hysteresis loop in nanocomposites in relation to pure nanoparticles were also found. In turn, the FT-MIR spectroscopy method was used to check the influence of the impurity concentration on the formation/disappearance or modification of the absorption bands, and the modification of both the FWHM and the maximum positions for the four selected vibrations in the MIR range, as well as the discontinuous behavior of these parameters at the phase transitions, were found
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