The influence of the hardening coolant agent on the properties of hot rolled bars of the steel 42CrMo4

In the work the influence results of two different hardening coolant agents on the basic mechanical proprieties and microstructure of the round hot rolled bars were presented. The bars of 42CrMo4 steel were exposed to analysis, and for those bars in the hardening process, water and modern pro-ecological polymer cooling agents Aqua Quench MK were used

A method for the selection of certain force and energy parameters of automatic sheet metal coiling machines

The paper concerns issues related to the sheet coiling process on processing lines. The industry’s needs and requirements for semi-finished products in the form of coil sheets are presented. The paper also discusses the results of the calculations of selected force and energy parameters of devices for coiling sheets made of a zinc-titanium alloy. The presented results were obtained based on calculations and a practical verification of the adopted assumptions using newly-designed devices introduced into operation

Diagnosis of the wear of gears in the gearbox using the wavelet packet transform

The paper presents research aimed at diagnosing early cases of wear of gears tooth surface in the gearbox based on measurements of vibration signals and their processing using the wavelet packet transform. Analysis concerned the vibration signals recorded in a test bench experiment, during which the wear of gears teeth increased (pitting and spalling). The studies allow conclusions to be drawn that the processing of vibration signals using the wavelet packet transform allows the detection of early cases of wear of the working surface of the teeth on the basis of an analysis of selected details of wavelet decomposition and vibration measures

A method for detecting damage to rolling bearings in toothed gears of processing lines

This paper presents a method of diagnosing damage to rolling bearings in toothed gears of processing lines. The research has shown the usefulness of vibration signal measurements performed with a laser vibrometer and of the method of denoising signals by means of a discrete wavelet transform in detecting damage to bearings. The application of the method of analysis of the characteristic frequencies of changes in the vibration signal amplitude made it possible to draw conclusions about the type of damage to the bearings

Zawartość metalicznych i niemetalicznych pierwiastków w homogenatach próbek tkankowych pobranych z amputowanych na poziomie uda z powodu miażdżycy kończyn dolnych. Doniesienie wstępne

Background: Metallic and non-metallic elements have influence on the development the changes within structure and function of arteries in different regions of vascular tree. The content of elements into arterial walls varies according to geographical origin of people. Material and methods: Tissue specimens were taken from the six lower limbs amputated on the level of thigh due to atherosclerosis. The mean age was 69 (57 to 84). Tissue specimens were collected from the limbs from the level of amputation, the popliteal fossa and the dorsal artery of foot. After chemical processing of the tissues homogenates determination of the content of elements using atomic emission spectrometry method with inductively coupled plasma (inductively coupled plasma optical emission spectroscopy) was performed. The content of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, P, S, Sr and Zn was determined. Results: As a point of reference mean absolute value occurred from six specimens on the level of thigh was assumed as 100%. Content of non-metallic elements such as Ca, P and S rise towards to periphery of amputated limb reaching few times higher values on the level of dorsal artery of foot. Content of some metallic elements such as: Fe, Zn, K and Sr also rise towards to periphery of extremity. The Cu accumulation was the highest on the level of popliteal fossa, while Mn, Al and Mg concentration was the lowest on this same level and the highest in dorsal artery of foot. Conclusions: The influence of individual elements on development the atherosclerosis especially on necrotic changes requires further investigations. Described problem pose a preliminary report only in order to indicate the issue and to check the method of analysis

Indoor allergens in settled dust from kindergartens in city of Łódź, Poland

Objectives: The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration. Material and Methods: A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children's clothing (N = 36). The samples were collected in springsummer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA). Results: The mean geometric concentrations (±geometric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02±3.21 μg/g of dust; 0.97±4.49 μg/g of dust; 0.30±4.43 μg/g of dust and 0.01±3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2±5.39 μg Can f1/g of dust; 3.63±1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001). Conclusions: Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens

Children’s residential exposure to selected allergens and microbial indicators: endotoxins and (1→3)-β-D-glucans

Objectives: The study was aimed at assessment of exposure to endotoxins, (1→3)-β-D-glucans and mite, cockroach, cat, dog allergens present in settled dust in premises of children as agents which may be significantly correlated with the occurrence of allergic symptoms and diseases in children. Materials and Methods: The study covered 50 homes of one- or two-year-old children in Poland. Samples of settled dust were taken from the floor and the child's bed. The levels of (1→3)-β-D-glucans (floor), endotoxins (floor) and allergens of mite, cat, dog and cockroach (floor and bed) were analyzed. Results: Average geometric concentrations (geometric standard deviation) of endotoxins, (1→3)-β-D-glucans, Der p1, Fel d1, Can f1 and Bla g1 in children homes were on the floor 42 166.0 EU/g (3.2), 20 478.4 ng/g (2.38), 93.9 ng/g (6.58), 119.8 ng/g (13.0), 288.9 ng/g (3.4), 0.72 U/g (4.4) and in their beds (only allergens) 597.8 ng/g (14.2), 54.1 ng/g (4.4), 158.6 ng/g (3.1) 0.6 U/g (2.9), respectively. When the floor was covered with the carpet, higher concentrations of endotoxins, (1→3)-β-D-glucans and allergens (each type) were found in the settled dust (p < 0.05). The trend was opposite in case of allergens (except dog) analyzed from bed dust and significantly higher concentrations were found in the rooms with smooth floor (p < 0.05). Conclusions: Among the analyzed factors only the type of floor significantly modified both the level of biological indicators and allergens. The results of this study could be the base for verifying a hypothesis that carpeting may have a protective role against high levels of cockroach, dog and cat allergens

Diagnosis of the wear of gears in the gearbox using the wavelet packet transform

The paper presents research aimed at diagnosing early cases of wear of gears tooth surface in the gearbox based on measurements of vibration signals and their processing using the wavelet packet transform. Analysis concerned the vibration signals recorded in a test bench experiment, during which the wear of gears teeth increased (pitting and spalling). The studies allow conclusions to be drawn that the processing of vibration signals using the wavelet packet transform allows the detection of early cases of wear of the working surface of the teeth on the basis of an analysis of selected details of wavelet decomposition and vibration measures