Separation and recovery of materials from scrap printed circuit boards

Printed circuit boards from waste computers, televisions, and mobile phones were pyrolysed in a fixed bed reactor with the aim of separating and recovering the organic and metallic materials. A selection of printed circuit boards from each of the three waste classes was pyrolysed at 800°C and the pyrolysis products were analysed using GC-FID, GC-TCD, GC-MS, GC-ECD, ICP-MS, and SEM-EDX. The pyrolysis oils contained high concentrations of phenol, 4-(1-methylethyl)phenol, and p-hydroxyphenol, as well as bisphenol A, tetrabromobisphenol A, methyl phenols, and bromophenols. The pyrolysis oils also contained significant concentrations of organo – phosphate compounds and a number of tetrabromobisphenol A pyrolysis products were also identified. The pyrolysis residues were very fragile and the organic, glass fibre, and metallic fractions could easily be separated and the electrical components could easily be removed from the remains of the printed circuit boards. The ash in the residue mainly consisted of copper, calcium, iron, nickel, zinc, and aluminium, as well as lower concentrations of valuable metals such as gallium, bismuth, silver, and gold, silver was present in particularly high concentrations. Many other metals were also identified in the ash by ICP-MS and SEM EDX. The pyrolysis gases mainly consisted of CO2 and CO but all of the C1 – C4 alkanes and alkenes were present, as were some inorganic halogens

Thermal Decomposition and Combustion of γ-irradiated Polyamide 6 Containing Phosphorus Oxynitride or Phospham

Polyamide 6 (PA-6) containing the fire retardants phosphorus oxynitride ((PON)m) or phospham ((PN2H)n) was exposed to 60Co-γ-rays (absorbed dose: 1.0–4.0 MGy). The irradiation led to crosslinking of the polymer which caused an increase in the char yield and a decrease in the flammability of the polymer. The combustion behavior was strongly affected by irradiation: dripping was totally prevented in the case of system PA-6/(PN2H)n and strongly retarded in the case of system PA-6/(PON)m. The thermal stability of the system PA-6/(PN2H)n decreased with increasing absorbed dose whereas the thermal stability of the system PA-6/(PON)m did not change

О книге Б. В. Яковлева «Повышение эффективности систем теплофикации и теплоснабжения»

The monograph contains generalized results of author’s investigations and practical work in respect of modernization of power-and-heat generation steam turbine plants with stage water heating.This book is intended for researchers, engineers and other technical personnel, lecturers, post graduates and students of heat power engineering specialities.Монография является обобщением результатов проведенной автором исследовательской и практической работы по совершенствованию теплофикационных паротурбинных установок со ступенчатым подогревом воды.Рассчитана на научных и инженерно-технических работников, преподавателей, Аспирантирантов и студентов теплоэнергетических специальностей

COVID-19-associated coagulopathy: a clinical case

Background. Comorbid patients with a new coronavirus disease (COVID-19) often have thrombosis or bleeding in different periods of the disease. Early diagnosis of these complications and adequate therapy of these patients are complicated due to the peculiarities of the disease in comorbidity. Anticoagulation regimens in patients with COVID-19 are still unclear. The protocol of efficacy and safety the intermediate or therapeutic dose of low-molecular-weight heparins  is not clear and complete. It is very important to organize an individual approach for correction of the anticoagulants doses, taking into account the coagulation tests and the activity of inflammatory markers.Clinical case description. We report a 71-year-old white male with COVID-19 pneumonia. Acute respiratory distress syndrome and atrial fibrillation were diagnosed in ten days of the disease. Therapeutic anticoagulation was started upon the admission. As early as in the 20th day of the disease a gluteal hematoma developed. Hence, prophylactic regimen of anticoagulation was started, but the worsening of dyspnea at rest, decreasing in SpO2 values to 82% according to pulse oximetry, and thrombelastographic hypercoagulability were observed after two days of such anticoagulation treatment. The patient has been receiving daily low-molecular-weight heparins injections in therapeutic doses for the following two weeks, and then the doctors have switched him to new oral anticoagulants. Patient was discharged to continue ambulatory anticoagulant’s treatment.Conclusion. It is clear that the optimal choice of anticoagulation strategy in comorbid patients with concomitant COVID-19 remains challenging and requires randomized trials. Until the guidelines develop the effective anticoagulation strategy for various phenotypes of COVID-19 patients, the clinicians’ knowledge, experience and creative thinking will be apply to choose effective anticoagulant’s treatment on individual basis

Gottron’s Carcinoid Papillomatosis: Case Report

Introduction. Gottron’s papillomatosis is a rare benign type of dermatosis with pseudoepitheliomatous hyperplasia of the epidermis, first described as an independent disease by the German dermatologist H.A. Gottron. Invasive epidermal growth and hyperkeratosis reveal no signs of malignancy. Chronic venous insufficiency and lymphedema can be associated with various secondary skin lesions: the formation of ulcers, hyperkeratosis and skin papillomatosis, as well as infectious complications. Skin papillomatosis may be a manifestation of paraneoplastic syndrome, which requires a careful differential diagnosis. Timely treatment of complications in a patient with concomitant somatic pathology performed by a multidisciplinary team of specialists is necessary to improve the prognosis. Considering the relative rarity of Gottron’s papillomatosis and the lack of awareness among practicing physicians regarding the differential diagnosis of this disease, we present this clinical analysis.Description of a clinical case. Patient L., 42 years old (body mass index — 76.5 kg/m2) with chronic lymphovenous insufficiency, lymphedema, erysipelas of the right lower limb associated with unspecified skin papillomatosis, was urgently hospitalized in a health care institution “City Clinical Hospital No. 3” of Grodno (Republic of Belarus), consulted by a multidisciplinary team of clinicians including a therapist, a cardiologist, a dermatologist, an endocrinologist, an infectious disease specialist, and a surgeon. Taking into account the clinical status of the patient and the retrospective analysis of archival records of previous examinations performed on the patient in the health care institution “Grodno University Clinic”, the type of dermatosis was determined as Gottron’s papillomatosis of both lower extremities. In terms of the clinical diagnosis of the patient, complex therapy was initiated in a hospital setting, which was then continued at the outpatient stage.Conclusion. Adequate long-term treatment of morbid obesity and chronic lymphovenous insufficiency is necessary to prevent serious complications. According to the academic literature, timely diagnosis of such a rare dermatosis as Gottron’s papillomatosis, as well as the prescription of adequate therapy determine the possibility of regression in the early stages of the disease

About the Book «Higher Efficiency of Power-and-Heat Generation and Heat Supply Systems»

The monograph contains generalized results of author’s investigations and practical work in respect of modernization of power-and-heat generation steam turbine plants with stage water heating.This book is intended for researchers, engineers and other technical personnel, lecturers, post graduates and students of heat power engineering specialities