Abstract The contents are concerned with a concept of an oilless and frictionless compressor operating without dead movement and having functional parameters superior to compressors of renowned manufacturers. The concept is based on patents No. 68220, 83060, P377851 by W. Chomczyk and patents P394072, P385733 by W. Chomczyk, W. Ostapski and J. Piotrowski. The proposed design of an oilless compressor ensures volumetric efficiency higher than that encountered in conventional compressors. It also generates pure compressed medium without necessity of filtering from oil particles, which is especially desired in food, pharmaceutical, medical, fragrance, chemical and automation industry.
In this work we report simulation and experimental results for an MWIR HgCdTe photodetector designed by computer simulation and fabricated in a joint laboratory run by VIGO Sytems S.A. and Military University of Technology. The device is based on a modified N+pP+ heterostructure grown on 2”., epiready, semi-insulating (100) GaAs substrates in a horizontal MOCVD AIX 200 reactor. The devices were examined by measurements of spectral and time responses as a function of a bias voltage and operating temperatures. The time response was measured with an Optical Parametric Oscillator (OPO) as the source of ~25 ps pulses of infrared radiation, tuneable in a 1.55–16 μm spectral range. Two-stage Peltier cooled devices (230 K) with a 4.1 μm cut-off wavelength were characterized by 1.6 × 1012 cm Hz1/2/W peak detectivity and < 1 ns time constant for V > 500 mV.
The article presents state of work in technology of free-space optical communications (Free Space Optics − FSO). Both commercially available optical data links and their further development are described. The main elements and operation limiting factors of FSO systems have been identified. Additionally, analyses of FSO/RF hybrid systems application are included. The main aspects of LasBITer project related to such hybrid technology for security and defence applications are presented.
The study presents the summary of the knowledge of energy-active segments of steel buildings adapted to obtain electrical energy (EE) and thermal energy (TE) from solar radiation, and to transport and store TE. The study shows a general concept of the design of energy-active segments, which are separated from conventional segments in the way that allows the equipment installation and replacement. Exemplary solutions for the design of energy-active segments, optimised with respect to the principle of minimum thermal strain and maximum structural capacity and reliability were given . The following options of the building covers were considered: 1) regular structure, 2) reduced structure, 3) basket structure, 4) structure with a tie, high-pitched to allow snow sliding down the roof to enhance TE and EE obtainment. The essential task described in the study is the optimal adaptation of energy-active segments in large-volume buildings for extraction, transportation and storage of energy from solar radiation.
Th e forearm is a body region of numerous anatomical variations. Due to its favorable anatomy fl exor digitorum superfi cialis muscle (FDS) is commonly used in tendon transfer surgeries. In this study a unique combination of abnormalities was found in a single forearm: the fl exor digitorum superfi cialis muscle penetrated by the median nerve, one of the fl exor digitorum superfi cialis tendons early division and absence of the palmaris longus muscle. Described variation potentially may lead to the clinical manifestation of the median nerve compression and should be also considered during FDS surgery.
Vegetable oils belong to a large group of substances consumed on a daily basis. World vegetable oil production is soaring, reducing the popularity of animal fats. Heavy metals pose a threat to human health. It is estimated that about 80% of the daily dose of heavy metals enters the human body through the consumption of food. Hence, it is necessary to monitor their concentrations in food products. Besides, the presence of heavy metals is thought to have possible negative influence on the quality of oils, especially on their taste and smell. Heavy metals may also accelerate the process of the rancidifiction of oils. Rapeseeds, soybean seeds and linseeds were selected for the analysis because they are one of the most popular oilseeds and at the same time they differ in terms of growing conditions. The analyses of different fractions and the ready-made product were also performed. The aim of the study was to determine the variation in concentrations of heavy metals, iron and manganese in different fractions during production. The significant concentrations of iron, manganese and zinc were observed in oilseeds. It was also shown that during different stages of oil refining the concentrations of metals decrease. The concentrations of metals are compared with those reported in literature.
The main goal of this study was to investigate possible residua of thymic tissue in 100 adult cadavers with no thoracic pathology known before, by dissection of standard locations of thymic tissue in perithyroid, periaortic, peritracheal and retrotracheal spaces, as well as areas located next to the course of phrenic, vagus and left recurrent laryngeal nerves. Thus obtained tissue samples were studied by two pathologists independently. The remnants of the thymic tissue were found in 61 out of 100 specimens studied. It means that residua of ectopic thymic tissue is common, which may have a huge impact on the results of treatment of many diseases i.e. myasthenia gravis in course of thymoma.