scholarly journals Impact of Basalt Filler and Ceramizable Additives on the Toxicity of Gaseous Products Emitted from Thermal Decomposition of Silicone Rubber Composites

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3478
Author(s):  
Przemysław Rybiński ◽  
Bartłomiej Syrek ◽  
Witold Żukowski ◽  
Dariusz Bradło

The article illustrates the impact of basalt filler in the form of flakes and fibres on the toxicity of gaseous products that formed during the thermal decomposition of silicone rubber composites. The values of specific emissions of gases were determined with the help of the IR spectroscopy and further applied to calculate the toxicometric index. The presented method of measuring the concentrations of gaseous products resulting from thermal decomposition consists in the application of a fluidised bed reactor, which makes it possible to conduct the decomposition of a sample at a precisely assumed temperature value and imitate the conditions of a real fire. At a temperature lower than 700 °C, the gases resulting from the thermal decomposition of composites are particularly toxic due to the presence of significant concentrations of formaldehyde that does not undergo oxidation to more stable inorganic products. At a temperature of 600 °C the toxicity of gases for the samples with ceramizable additives and without them was similar. In the first case, there appeared to be a positive synergistic effect of mineral and basalt additives, and the basalt additives themselves increased the toxicity of gases. At higher temperatures of decomposition, the exponentially increasing rate of the oxidation reaction in the gaseous phase results in the lack of significant differences between the toxicity of gases for the samples with and without basalt additives. The toxicometric index value at temperatures of 700 °C and 800 °C was by one or two orders of magnitude higher, respectively, than the one that was observed in the temperature range of 500–600 °C, as inorganic components appear in the place of formaldehyde.

2021 ◽  
Vol 93 (2) ◽  
pp. 31-43
Author(s):  
Iryna Leshchukh ◽  
Olha Mulska

o analyse the impact of Lviv on centre-periphery interactions the authors calculated the Socio-Economic Development Index for different districts of the region and considered the distance of each district from the regional capital. The Socio-Economic Development Index (Іr) of each district was calculated as the arithmetic mean of indices of its economic (Іе) and social (Іs) development. A strong inverse relationship was found between districts’ indices and their distances from the regional capital (R = –0.69). The indices were used to classify districts into three categories: central, semi-peripheral, and peripheral. The central category includes districts located within a 50-km radius of Lviv and their indices range from 0.5 to 0.7. Semi-peripheral districts are located within the radius of 50-75 km and their Іr values range from 0.3 to 0.5. Peripheral districts are located at the furthest distance from the regional centre, and their Іr values are below 0.3. Because the correlation between the distance from the regional center and index value for some districts was not consistent with the general pattern, two subtypes of districts were also added – core and ancillary. The authors demonstrate that the impact of the regional capital on the socio-economic development of administrative districts decreases with their increasing distance from the regional center. The level of socio-economic development in districts depends, on the one hand, on the strength of impulses generated by the regional center, and on the other hand, is determined by the local economic capacity and ability to absorb the impacts of the regional center and other local growth poles.


2017 ◽  
Vol 38 (3) ◽  
pp. 411-422
Author(s):  
Katarzyna Bizon

Abstract Steady-state characteristics of a catalytic fluidised bed reactor and its dynamical consequences are analyzed. The occurrence of an untypical steady-state structure manifesting in a form of multiple isolas is described. A two-phase bubbling bed model is used for a quantitative description of the bed of catalyst. The influence of heat exchange intensity and a fluidisation ratio onto the generation of isolated solution branches is presented for two kinetic schemes. Dynamical consequences of the coexistence of such untypical branches of steady states are presented. The impact of linear growth of the fluidisation ratio and step change of the cooling medium temperature onto the desired product yield is analyzed. The results presented in this study confirm that the identification of a region of the occurrence of multiple isolas is important due to their strong impact both on the process start-up and its control.


2021 ◽  
Vol 12 ◽  
Author(s):  
Diana Borges Duarte ◽  
Lia Ferreira ◽  
Ana P. Santos ◽  
Cláudia Costa ◽  
Jorge Lima ◽  
...  

IntroductionPheochromocytomas are rare catecholamine-producing neuroendocrine tumours arising from chromaffin cells of the adrenal medulla or extra-adrenal sympathetic paraganglia. Recent studies have indicated that up to 40% of pheochromocytomas could be attributable to an inherited germline variant in an increasing list of susceptibility genes. Germline variants of the MYC-associated factor (MAX) gene have been associated with familial pheochromocytomas and paragangliomas with an autosomal dominant pattern of inheritance, a median age at onset of 33 years and an overall frequency estimated at 1.9%. We describe a deleterious MAX variant associated with hereditary pheochromocytoma in a family with four affected individuals.Case presentationThe first patient presented with bilateral pheochromocytoma in 1995; genetic testing was proposed to his oldest son, when he was diagnosed with a bilateral pheochromocytoma with a synchronous neuroblastoma. Upon the identification of the MAX variant c.97C>T, p.(Arg33Ter), in the latter individual, his two siblings and their father were tested and the same variant was identified in all of them. Both siblings were subsequently diagnosed with pheochromocytoma (one of them bilateral) and choose to remain on active surveillance before they were submitted to adrenalectomy. All the tumours secreted predominantly norepinephrine, accordingly to the typical biochemical phenotype ascribed to variants in the MAX gene.ConclusionThis case series is, to our knowledge, the one with the largest number of individuals with hereditary pheochromocytoma with a deleterious MAX variant in the same family. It is also the first case with a synchronous pheochromocytoma and neuroblastoma in carriers of a MAX deleterious variant. This report draws attention to some ill-defined features of pheochromocytoma and other malignancies associated with a MAX variant and highlights the importance of understanding the genotype-phenotype correlation in hereditary pheochromocytoma and the impact of oriented genetic testing to detect, survey and treat patients and kindreds at risk.


2019 ◽  
Vol 79 ◽  
pp. 106040 ◽  
Author(s):  
Przemysław Rybiński ◽  
Dariusz Bradło ◽  
Witold Żukowski ◽  
Bartłomiej Syrek

2013 ◽  
Vol 12 (7) ◽  
pp. 451-459
Author(s):  
Ashraf Yehia El-Naggar ◽  
Mohamed A. Ebiad

Gasoline come primarily from petroleum cuts, it is the preferred liquid fuel in our lives. Two gasoline samples of octane numbers 91 and 95 from Saudi Arabia petrol stations were studied. This study was achieved at three different temperatures 20oC, 30oC and 50oC representing the change in temperatures of the different seasons of the year. Both the evaporated gases of light aromatic hydrocarbons (BTEX) of gasoline samples inside the tank were subjected to analyze qualitatively and quantitatively via capillary gas chromatography. The detailed hydrocarbon composition and the octane number of the studied gasoline samples were determined using detailed hydrocarbon analyzer. The idea of research is indicating the impact of light aromatic compounds in gasoline on the toxic effect of human and environment on the one hand, and on octane number of gasoline on the other hand. Although the value of octane number will be reduced but this will have a positive impact on the environment as a way to produce clean fuel.


2017 ◽  
Vol 13 ◽  
pp. 244-261
Author(s):  
Mariola Tracz ◽  
Małgorzata Bajgier-Kowalska ◽  
Radosław Uliszak

Podkarpackie Voivodeship is one of the regions of Poland in which the number of agritourism entities is very high. Therefore tourism plays a significant role in its development strategy. The aim of the paper is to identify the current state of agritourism and the changes that have occurred in the region in the years 2000–2016. Specific objectives are to determine the distribution of agritourism farms and their offer, together with a comprehensive analysis of the environmental and socio-economic factors, as well as the impact of the Slovak-Ukrainian border. The report was developed on the statistical materials from the Polish Central Statistical Office, Podkarpackie Agricultural Advisory Centre in Boguchwała and data collected from municipalities and district offices that is published on their websites, as well as through interviews with 100 owners of agritourism farms in the Podkarpackie Voivodeship. The research has shown, on the one hand, the decline in the number of farms in the region and, on the other hand, the increase in the diversity of the tourist offer of these entities. Distribution of agritourism farms is closely linked to the attractiveness of natural environment and quality of secondary tourism resources. Traditional agritourism has not yet fully used its countryside, as well as cross-border advantages of its location.


2020 ◽  
Author(s):  
Ahmed Youssef Kada

BACKGROUND Covid-19 is an emerging infectious disease like viral zoonosis caused by new coronavirus SARS CoV 2. On December 31, 2019, Wuhan Municipal Health Commission in Hubei province (China) reported cases of pneumonia, the origin of which is a new coronavirus. Rapidly extendable around the world, the World Health Organization (WHO) declares it pandemic on March 11, 2020. This pandemic reaches Algeria on February 25, 2020, date on which the Algerian minister of health, announced the first case of Covid-19, a foreign citizen. From March 1, a cluster is formed in Blida and becomes the epicentre of the coronavirus epidemic in Algeria, its total quarantine is established on March 24, 2020, it will be smoothly alleviated on April 24. A therapeutic protocol based on hydroxychloroquine and azithromycin was put in place on March 23, for complicated cases, it was extended to all the cases confirmed on April 06. OBJECTIVE This study aimed to demonstrate the effectiveness of hydroxychloroquin/azithromycin protocol in Algeria, in particular after its extension to all patients diagnosed COVID-19 positive on RT-PCR test. We were able to illustrate this fact graphically, but not to prove it statistically because the design of our study, indeed in the 7 days which followed generalization of therapeutic protocol, case fatality rate decrease and doubling time increase, thus confirming the impact of wide and early prescription of hydroxychloroquin/azithromycin protocol. METHODS We have analyzed the data collected from press releases and follow-ups published daily by the Ministry of Health, we have studied the possible correlations of these data with certain events or decisions having a possible impact on their development, such as confinement at home and its reduction, the prescription of hydroxychloroquine/azithromycin combination for serious patients and its extension to all positive COVID subjects. Results are presented in graphics, the data collection was closed on 31/05/2020. RESULTS Covid-19 pandemic spreads from February 25, 2020, when a foreign citizen is tested positive, on March 1 a cluster is formed in the city of Blida where sixteen members of the same family are infected during a wedding party. Wilaya of Blida becomes the epicentre of coronavirus epidemic in Algeria and lockdown measures taken, while the number of national cases diagnosed begins to increases In any event, the association of early containment measures combined with a generalized initial treatment for all positive cases, whatever their degree of severity, will have contributed to a reduction in the fatality rate of COVID 19 and a slowing down of its doubling time. CONCLUSIONS In Algeria, the rapid combination of rigorous containment measure at home and early generalized treatment with hydroxychloroquin have demonstrated their effectiveness in terms of morbidity and mortality, the classic measures of social distancing and hygiene will make it possible to perpetuate these results by reducing viral transmission, the only unknown, the reopening procedure which can only be started after being surrounded by precautions aimed at ensuring the understanding of the population. CLINICALTRIAL Algeria, Covid-19, pandemic, hydroxychloroquin, azithromycin, case fatality rate


Author(s):  
Anna Peterson

This book examines the impact that Athenian Old Comedy had on Greek writers of the Imperial era. It is generally acknowledged that Imperial-era Greeks responded to Athenian Old Comedy in one of two ways: either as a treasure trove of Atticisms, or as a genre defined by and repudiated for its aggressive humor. Worthy of further consideration, however, is how both approaches, and particularly the latter one that relegated Old Comedy to the fringes of the literary canon, led authors to engage with the ironic and self-reflexive humor of Aristophanes, Eupolis, and Cratinus. Authors ranging from serious moralizers (Plutarch and Aelius Aristides) to comic writers in their own right (Lucian, Alciphron), to other figures not often associated with Old Comedy (Libanius) adopted aspects of the genre to negotiate power struggles, facilitate literary and sophistic rivalries, and provide a model for autobiographical writing. To varying degrees, these writers wove recognizable features of the genre (e.g., the parabasis, its agonistic language, the stage biographies of the individual poets) into their writings. The image of Old Comedy that emerges from this time is that of a genre in transition. It was, on the one hand, with the exception of Aristophanes’s extant plays, on the verge of being almost completely lost; on the other hand, its reputation and several of its most characteristic elements were being renegotiated and reinvented.


Sign in / Sign up

Export Citation Format

Share Document