ТЕХНИЧЕСКИЕ АСПЕКТЫ ДИЗАЙНА ЮВЕЛИРНЫХ ИЗДЕЛИЙ

The paper considers an influence of technical factors on jewelry design and provides an analysis of literature data that reveals that main investigations in this field are devoted to the following three problems, namely: problems pertaining to usage of up-to-date IT-technologies in design modeling; material science problems pertaining to influence of decorative and technological properties of the applied materials on esthetic quality of objects and also problems pertaining to manufacturing technology and decorative processing of jewelry.  An important role is played by systematic module approach to training of designers and specialists involved in designing and manufacturing of jewelry. Рассмотрено влияние технических факторов на дизайн ювелирных изделий. Сделан анализ литературных данных, из которого следует, что основные исследования в этой области посвящены изучению трех вопросов. К их числу относятся: вопросы использования современных IT-технологий в проектном моделировании; материаловедческие проблемы влияния декоративных и технологических свойств, применяемых материалов на эстетические качества объектов, а также проблемы технологии изготовления и декоративной обработки ювелирных украшений. Немаловажную роль при этом играет системный, модульный подход к подготовке дизайнеров и специалистов, занимающихся проектированием и изготовлением ювелирных изделий

Влияние ультразвуковых колебаний на величину сил резания в процессе алмазной доводки ювелирных камней

An influence of ultrasound vibrations initiated in a tool on decrease of cutting forces in the process of abrasive machining of jewel specimens has been investigated. The paper contains description of an pilot unit, a tool design and methodology of investigations. Mechanism of contact interaction due to ultrasound vibrations is described in the paper. Quantitative evaluation of decrease in cutting forces acting in the finishing zone and influence of acoustic and technological factors on the rate of decrease in these forces are given and determined in the paper.Исследовано влияние ультразвуковых колебаний, возбуждаемых в инструменте, на снижение сил резания в процессе абразивной обработки образцов ювелирных камней. Приведены описание экспериментальной установки, конструктивное исполнение инструмента и методика исследований. Описан механизм контактного взаимодействия при воздействии ультразвуковых колебаний; приведена количественная оценка снижения сил резания, действующих в зоне обработки; установлено влияние акустических и технологических факторов на степень снижения этих сил

Экспериментальная оценка влияния ультразвука на производительность и качество алмазной доводки хрупких материалов

The paper gives main principles of the methodology for execution of experimental investigations with the help of principally newly designed ultrasound machine-tool with acoustic system which is set in the spindle unit. Treatment of a number of semi-precious stones and mono-crystals by diamond tools of various graininess has revealed dominating technological factors that influence on quantitative and qualitative process indice. Mechanisms of inter-relation of a lapping disk and a treated piece with directed action of ultrasound oscillation are given in the paper. The obtained results testify efficiency of ultrasound application for treatment of hard and fragile materials (crystals).Приводятся основные положения методики проведения экспериментальных исследований на принципиально новой конструкции ультразвукового станка с акустической системой в шпиндельном узле. В результате обработки ряда поделочных камней и монокристаллов алмазоносными инструментами различной зернистости получены результаты, которые выявили доминирующие технологические факторы, влияющие на количественные и качественные показатели процесса. Даны механизмы взаимодействия диска-притира и обрабатываемого изделия при направленном действии ультразвуковых колебаний. Результаты свидетельствуют об эффективности использования ультразвука при обработке твердых и хрупких материалов (кристаллов)

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications: LAS VEGAS - An observational study in 29 countries

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (V T) size was 500 ml, or 7 to 9 ml kg−1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P ˂ 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P ˂ 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high V T and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome.</p

DYNAMICS OF VIBRATIONS OF A ROD ATTACHED TO THE ELASTIC ELEMENT

The paper presents a calculation of static and dynamic component of the displacement of the rod attached to an elastic element. A mathematical model of the dynamic processes of the rod, supported by a spring is supposed. The equations obtained by solving the wave equation, allow us to estimate the influence of the elastic properties of the springs on the movement of the rod. On the basis of the results suggested devices and ultrasound system with an elastic element

Experimental Evaluation of Ultrasound Influence on Productivity and Quality of Diamond Finishing of Fragile Materials

The paper gives main principles of the methodology for execution of experimental investigations with the help of principally newly designed ultrasound machine-tool with acoustic system which is set in the spindle unit. Treatment of a number of semi-precious stones and mono-crystals by diamond tools of various graininess has revealed dominating technological factors that influence on quantitative and qualitative process indice. Mechanisms of inter-relation of a lapping disk and a treated piece with directed action of ultrasound oscillation are given in the paper. The obtained results testify efficiency of ultrasound application for treatment of hard and fragile materials (crystals)