Characterization and Failure Analysis of Plastics

Volume 11B serves as a reference and guide to help engineers determine the causes of failure in plastic components and make corrective adjustments through design and manufacturing modifications. It contains seven major divisions, covering polymer science and processing, material selection and design, chemical, thermal, and physical analysis, mechanical behavior and testing, degradation mechanisms, systematic failure analysis, and life assessment and optimization. It examines a wide range of factors that contribute to the properties and behaviors of engineering plastics and the effect of thermal and mechanical stresses, impact loading, fatigue, wear, weathering, moisture and chemical exposure, photochemical aging, microbial degradation, and elevated temperatures. It addresses issues such as flammability, environmental stress cracking, crazing, and stress whitening and describes the unique characteristics of polymer fracture and how to assess and predict service life using fracture mechanics. It also presents and analyzes numerous examples of failure, including design and manufacturing related failures, wear failures of reinforced plastics, and failures due to creep and yielding.

Characteristics of product complementary feeding with fortified fish protein hydrolysate (FPH)

Malnutrition is still a major problem in Indonesia, particularly stunting and acute malnutrition due to protein deficiency. In contrast, Indonesia is rich in protein sources such as fish but they are poorly utilized. Biologically processed fish protein hydrolysate (FPH) has proven to be highly nutritious and digestible. Our preliminary study in developing the High Protein Complementary Food (HPCF) formula for infant enriched with FPH, showed that of 17 formulas, 3 formulas was the best. This study was aimed to analyzing sensory analysis using the hedonic test, physical analysis and absorption protein. The result shows that the hedonic test of FPH-enriched HPCF infant food revealed that the product was acceptable in term of colour, aroma and texture. In comparison to the commercial product, FPH-enriched instant HPCF infant product had higher bulk density. The highest Water Absorption Index (WAI) was F1-C, the highest Water Solubility Index (WSI) was F1-P, and the lowest rehydration was F2-P. Compared to commercial products, the instant FPH-enriched HPCF baby porridge has a bulk density that is greater than that of commercial products. The highest Water Absorption Index (WAI) was F1-C, the highest Water Solubility Index (WSI) was F1-P and the lowest time for Rehydration was at F2-P. HPCF enriched with FPH showed the best protein absorption significantly in the P2 treatment group

Mechanism for inverted-repeat recombination induced by a replication fork barrier

Replication stress and abundant repetitive sequences have emerged as primary conditions underlying genomic instability in eukaryotes. To gain insight into the mechanism of recombination between repeated sequences in the context of replication stress, we used a prokaryotic Tus/Ter barrier designed to induce transient replication fork stalling near inverted repeats in the budding yeast genome. Our study reveals that the replication fork block stimulates a unique recombination pathway dependent on Rad51 strand invasion and Rad52-Rad59 strand annealing activities, Mph1/Rad5 fork remodelers, Mre11/Exo1/Dna2 resection machineries, Rad1-Rad10 nuclease and DNA polymerase δ. Furthermore, we show recombination at stalled replication forks is limited by the Srs2 helicase and Mus81-Mms4/Yen1 nucleases. Physical analysis of the replication-associated recombinants revealed that half are associated with an inversion of sequence between the repeats. Based on our extensive genetic characterization, we propose a model for recombination of closely linked repeats that can robustly generate chromosome rearrangements.

Quo Vadis Nonlinear Optics? An Alternative and Simple Approach to Third Rank Tensors in Semiconductors

It is well understood that nonlinear optical (NLO) phenomena are deeply related to the material’s symmetry. Mathematically, the material symmetry can be described in terms of the nonzero parameters in the nonlinear susceptibility tensors. Generally, more complex structures involve more nonzero parameters in the tensor. The number of parameters increases rapidly if higher NLO orders are considered, complicating the physical analysis. Conventionally, these parameters are obtained via abstract symmetry analysis, e.g., group theory (GT). This work presents a novel theoretical analysis to approach the nonlinear tensor using the simplified bond hyperpolarizability model (SBHM) and compare it with GT. Our analysis is based on a light–matter interaction classical phenomenological physical framework. Rather than just looking at the symmetry of the crystal, the model applies physical considerations requiring fewer independent parameters in the tensor than GT. Such a simplification significantly improves the determination of the surface–bulk SHG contribution factors, which cannot be extracted from the experiment alone. We also show for the case of perovskite that the SHG contribution can be addressed solely from their surface dipoles with only one independent component in the tensor. Therefore, this work may open the path for a similar analysis in other complicated semiconductor surfaces and structures in the future, with potential applications to nanoscale surface characterization and real-time surface deposition monitoring.

Зависимость температуры сублимации образующихся в пламенах сажевых частиц от их размеров и структуры

In this paper, the dependence of the sublimation temperature of soot particles synthesized during the combustion of various hydrocarbons, depending on their size and structure, is obtained. The experimental approach is based on the analysis of the thermal radiation of particles heated to the sublimation temperature by a nanosecond laser pulse. The sublimation temperature of soot particles was measured using the two-color pyrometry method. In this paper, it is proposed to use the average size of primary particles to compare data in different flames. It is established, that the sublimation temperature of soot particles depends mainly on the stage of their formation, which is characterized by an increase in average size. It is shown, that with an increase in the average particle size from 12 to 23 nm, their sublimation temperature increases significantly from 2700 to 4500 K. This reflects a significant difference in the thermodynamic and optical properties of the so-called "young" and "mature" soot particles, which must be taken into account when developing methods of soot diagnostics and in the thermo-physical analysis of combustion and pyrolysis processes with the formation of soot.

SOME ASPECTS OF PREDICTING THE SEVERITY OF VIRUS-INDUCED BRONCHIAL ASTHMA EXACERBATION IN CHILDREN DUE TO COVID-19 PANDEMIC

bronchial asthma is an important medical and social issue directly affects the health of patients, their quality of life, and the direct and indirect economic costs associated with the disease are quite significant. Due to the pandemic caused by a new strain of coronavirus SARS-CoV-2, international and domestic regulations documents have updated the management of patients with asthma. In particular, there have been recommendations for remote visits to assess the patients’ complaints however physical analysis and objective examination are not available during such consultations. It can lead to errors in diagnostic of asthma exacerbation severity and treatment tactic for prescription the reliever therapy. So it is actuality to find out additional indicators to improve the diagnostic and prediction of the severity of the disease exacerbations. Given the urgency of the problem, the aim of the study is to evaluate the clinical and paraclinical parameters in children with virus-induced bronchial asthma exacerbation to predict the severity of the asthma attack and personify the management of patients. Have been examined 47 patients who were hospitalized for disease exacerbation. The severity of a asthma attack was considered a group-forming feature. Statistical analysis was performed using parametric and nonparametric calculation methods, methods of clinical epidemiology and biostatistics. The results of the study give grounds to predict a more severe asthma attack among urban residents who have a phenotype of late-onset asthma. An additional, anamnestic risk of more severe exacerbation of the disease is body weight at birth, which exceeds 3500 g. Among spirometric indicators the highest prognostic criterion for severe bronchial asthma exacerbation was the general index of bronchodilation, which was 15% and above, as well as the index of bronchodilation at the level of the distal airways with a cut-off point of 30% and above. In the presence of the above risk factors for severe asthma attack on the background of confirmed infection with the coronavirus strain SARS-CoV-2 the patient needs hospitalization, antiviral treatment, increasing the dose of inhaled steroids and additional β2-agonists. When predicting a mild or moderate asthma attack provoked by the coronavirus SARS-CoV-2, it is advisable to continue remote monitoring by an allergist and the management of exacerbation includes a temporary increase daily dose of inhaled glucocorticosteroids and additional using of β2-agonists. It is recommended to avoid taking nebulizers and use individual metered powder or aerosol inhalers in cases of inpatient treatment.

Effects of Donkeys Rearing System on Performance Indices, Carcass, and Meat Quality

This study compared growth rates, carcass, and meat quality obtained from 24 male crossbred donkey foals reared for meat production under an intensive (I) or extensive (E) feeding system. Donkeys were slaughtered at 16 months of age; the average final body weight, hot and cold carcass weight, and hot and cold dressing percentage were significantly higher (p < 0.05) in the I group. Samples of Longissimus Thoracis et Lumborum (LTL) were taken from each foal for chemical and physical analysis. Group I showed significant (p < 0.05) higher intramuscular fat, while the E group showed significantly (p < 0.05) higher protein and unsaturated fatty acids (UFA) contents, including n-3 essential fatty acids. Saturated fatty acids (SFA) and glycogen were significantly higher (p < 0.05) in the intensive system, monounsaturated fatty acids (MUFA) were significantly higher in the extensive system. The ratio PUFA/SFA was significantly higher (p < 0.05) in group E. The Thrombogenic Index (TI) was significantly higher (p < 0.05) in the I group. Meat tenderness was significantly higher (p < 0.05) in group I. The feeding system had no effect on cholesterol content and meat color characteristics. Donkeys average daily gain, carcass weight, and some meat quality parameters were significantly affected by the rearing system.

Fractional order plasma modeling based on linear polarization of LASER light: an Atangana–Baleanu Caputo approach

PurposeThe purpose of this offered research is to articulate a multifaceted kind of highly unstable initial perturbation and further analyze the performance of the plasma particles for time-fractional order evaluation.Design/methodology/approachFor this purpose, the authors designed specific geometry and further interpreted it into the mathematical model using the concepts of the Vlasov Maxwell system. The suggested algorithm is based on the finite-difference and spectral estimation philosophy. The management of time and memory in generic code for computational purposes is also discussed.FindingsThe main purpose is to analyze the fractional behavior of plasma particles and also the capability of the suggested numerical algorithm. Due to initial perturbations, there are a lot of sudden variations that occurred in the formulated system. Graphical behavior shows that SR parameter produces devastation as compared to others. The variation of fractional parameter between the defend domain demonstrates the hidden pictures of plasma particles. The design scheme is efficient, convergent and has the capability to cover the better physics of the problem.Practical implicationsPlasma material is commonly used in different areas of science. Therefore, in this paper, the authors increase the capability of the mathematical plasma model with specific geometry, and further suitable numerical algorithm is suggested with detailed physical analysis of the outcomes. The authors gave a new direction to study the performance of plasma particles under the influence of LASER light.Originality/valueIn the recent era, science has produced a lot of advancements to study and analyze the physical natural process, which exist everywhere in the real word. On behalf of this current developments, it is now insufficient to study the first-order time evaluation of the plasma particles. One needs to be more precise and should move toward the bottomless state of it, that is, macroscopic and microscopic time-evaluation scales, and it is not wrong to say that there exits a huge gap, to study the time evaluation in this discussed manner. The presented study is entirely an advanced and efficient way to investigate the problem into the new directions. The capability of the proposed algorithm and model with fractional concepts can fascinate the reader to extend to the other dimensions.