Experimental and numerical stress and strain analysis of the boiler reversing chamber tube plate

Boilers are one of the most used units for both heat generation plants and industry systems. Their operation is subjected to different working loads and maintenance requirements. Exploitation experience points out critical boiler zones where failures and break downs typically occur. This paper analyzes critical zones in hot water fire-tube boiler. Experimental procedure was performed on the model of this type of boilers and its critical element. The tube plate of hot water boiler was identified as the most critical one. Experimental analysis and numerical model verification were performed using Aramis system based on 3-D digital image correlation method. Numerical analysis was done in ANSYS software package and verification of results was done based on measurements obtained by strain gauges and local measurements performed by the Aramis system. Stress-strain analysis indicates the critical zones of boiler tube plate. The character of change parameters such as strain and stress occurring in the critical zones can be verified both by experimental and numerical data. The paper presents a novel approach in experimental and numerical analyses that can be conducted in similar units and used for existing unit optimization, as well as for new product testing on different loads and provide opportunity for further development and improvement for practical industrial application

Influence of breed, season and gender on chemical composition and meat quality of pigs

The effect of breed, gender and the farrowing season on the variability of pork quality traits was examined in the present study. The observed properties were the pH value (pH45 and pH24) of the Longissimus dorsi muscle (LD) and Semimembranosus muscle (SM), the chemical composition (water, fat, ash and protein content), the water binding capacity, the colour and thickness of the LD fibres. In the present study, the influence (P lt 0.05) of the farrowing season for both measured pH values in SM was established, as well as significant influence (P lt 0.01) on pH24 in LD, while the other factors did not influence the pH of the muscles tested. The established difference in the mean values of water content in LD between fatteners SW and LWxSL (0.69%) was statistically very significant (P lt 0.001) while the influence of genotype and sex of fatteners was not determined for fat, ash and protein content. The genotype of fatteners influenced the ability to bind water (P lt 0.001) and the meat colour (P lt 0.05) while the muscle thickness was not affected (P> 0.05)

Successfully treated multiple brain abscess in a newborn: A case report

Multiple brain abscesses are exceedingly uncommon in newborns and represent a serious medical problem associated with high morbidity and mortality. Treatment is also controversial issue, and can require surgery, abscess aspiration, antibiotic therapy, and eradication of the primary source. We report a case of successfully treated multiple brain abscess in a newborn with combined therapy which consisted of abscess aspiration and prolonged antibiotics. Patient developed hydrocephalus as late complication which was also successfully treated with ventriculoperitoneal shunt

Effects of structural optimization on practical roof truss construction

© 2019 Published by the Serbian Academic Center. In truss structural optimization the most frequently optimized factor of a structure is its weight. The minimization of weight contributes not only to savings in material, but also in other aspects of the structure such as number of elements used, number of welds needed, outer surface area, etc. This research aims to show the difference in optimal solutions for four different topological cases of a typical trapezoidal roof truss looking at their effects on overall outer surface area. The truss layouts are optimized for sizing, and a combination of sizing and shape with a minimal weight objective function. In order to ensure the most practically applicable solutions the example optimized in this paper uses dynamic constraints for buckling, stress constraints, and nodal displacement constraints. The overall outer surface area for all cases is compared, as surface protection accounts for a substantial part of the total cost of roof truss construction. Optimal solutions show a lack of correlation between weight and surface area, which is discussed in the conclusion

Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: Compatibility study with detergent ingredients and washing performance

An indigenous Pseudomonas aeruginosa strain has been studied for lipase and protease activities for their potential application in detergents. Produced enzymes were investigated in order to assess their compatibility with several surfactants, oxidizing agents and commercial detergents. The crude lipase appeared to retain high activity and stability in the presence of several surfactants and oxidizing agents and it was insusceptible to proteolysis. Lutensol (R) XP80 and Triton (R) X-100 strongly activated the lipase for a long period (up to 40 and 30% against the control after 1 h) while the protease activity was enhanced by the addition of Triton (R) WR1339 and Tween (R) 80. The washing performance of the investigated surfactants was significantly improved with the addition of the crude enzyme preparation. Studies were further undertaken to improve enzymes production. The optimization of fermentation conditions led to an 8-fold increase of lipase production, while the production of protease was enhanced by 60%

SYNCHRONOUS MANEC (MIXEDADENO-NEUROENDOCRINE CARCINOMA) OF THE COLON AND RENAL CELL CARCINOMA-CASE REPORT

Synchronous multiple carcinomas represent two or more primary carcinoma that occur sumultaneously in the same patient. In order to fulfill the condition that tumors are synchronous, each tumor must be primary and not a metastasis of another tumor. The occurrence of renal carcinoma synchronously with colonic carcinoma is not so common. On the other hand, the pathohistological image in rare cases shows a mixed glandular and neuroendocrine component described in earlier works. In this paper, we present a patient who made a colonoscopy, a biopsy from a tumor change in the cecum due to malady, fainting, loss of appetite, and a positive test for faecal occult bleeding, and confirmed that it is an a-denocarcinoma of the cecum. Multi slise computerized tomography of the abdomen also described a tumor change in the uretero-pelocalrix system of the left kidney region. The patient had no urinary tract disorders. The diagnosis of the synchronous tumor of the cecum and left kidney was set. A right hemicolectomy with latero-lateral ileo-transverse anastomosis, as well as left nephroureterectomy, was performed. What is particularly interesting in this case is that the pathohistological picture of the cecum carcinoma shows a rare form of tumor tone, mixed adeno-neuroendocrine carcinoma. In patients with diagnosed colorectal cancer, routine as well as additional preoperative diagnostic procedures should be performed to exclude the existence of kidney cancer, since, when synchronous with colorectal carcinoma occurs, renal carcinoma is mainly asymptomatic. In rare cases, the pathohistological picture may also show the neuroendocrine component of the tumor, which directs further therapy to the other direction

Lessons from the 2018-2019 European droughts: a collective need for unifying drought risk management

Drought events and their impacts vary spatially and temporally due to diverse pedo-climatic and hydrologic conditions, as well as variations in exposure and vulnerability, such as demographics and response actions. While hazard severity and frequency of past drought events have been studied in detail, little is known about the effect of drought management strategies on the actual impacts and how the hazard is perceived by relevant stakeholders. In a continental study, we characterised and assessed the impacts and the perceptions of two recent drought events (2018 and 2019) in Europe and examined the relationship between management strategies and drought perception, hazard, and impact. The study was based on a pan-European survey involving national representatives from 28 countries and relevant stakeholders responding to a standard questionnaire. The survey focused on collecting information on stakeholders' perceptions of drought, impacts on water resources and beyond, water availability, and current drought management strategies on national and regional scales. The survey results were compared with the actual drought hazard information registered by the European Drought Observatory (EDO) for 2018 and 2019. The results highlighted high diversity in drought perception across different countries and in values of the implemented drought management strategies to alleviate impacts by increasing national and sub-national awareness and resilience. The study identifies an urgent need to further reduce drought impacts by constructing and implementing a European macro-level drought governance approach, such as a directive, which would strengthen national drought management and mitigate damage to human and natural assets

Lessons from the 2018-2019 European droughts: a collective need for unifying drought risk management

Drought events and their impacts vary spatially and temporally due to diverse pedo-climatic and hydrologic conditions, as well as variations in exposure and vulnerability, such as demographics and response actions. While hazardous severity and frequency of past drought events have been studied in detail, little is known about the effect of drought management strategies on the actual impacts, and how the hazard is perceived by relevant stakeholders for inducing action. In a continental study, we characterised and assessed the impacts and the perceptions of two recent drought events (2018 and 2019) in Europe and examined the relationship between management strategies and drought perception, hazard and impacts. The study was based on a pan-European survey involving national representatives from 28 countries and relevant stakeholders responding to a standard questionnaire. The survey focused on collecting information on stakeholders’ perceptions of drought, impacts on water resources and beyond, water availability and current drought management strategies at national and regional scales. The survey results were compared with the actual drought hazard information registered by the European Drought Observatory (EDO) for 2018 and 2019. The results highlighted high diversity in drought perceptions across different countries and in values of implemented drought management strategies to alleviate impacts by increasing national and sub-national awareness and resilience. The study concludes with an urgent need to further reduce drought impacts by constructing and implementing a European macro-level drought governance approach, such as a directive, which would strengthen national drought management and lessen harm to human and natural potentials