Modyfikacja powierzchni stopu Ti-6Al-4V metodą PEO-EPD w zawiesinie ZrSiO4

Investigations on the surface modification of the Ti-6Al-4V alloy by plasma electrolytic oxidation are reported here. The oxidation process was carried out in a solution containing a zirconium silicate (ZrSiO4) suspension and sodium hydroxide (NaOH). Anodising was realised at voltages in a range from 100 V to 250 V. It was found that the morphology of the sample surface did not change during the oxidation of the alloy at 100 V. Application of voltages higher than 100 V led to the incorporation of zirconium silicate into the formed oxide layer and to significant changes of the surface morphology

Acoustic signalisation in the work environment of the disabled persons

Sygnały akustyczne w środowisku pracy, ze względu na ich funkcje użytkowe, można podzięk na informacyjne i bezpieczeństwa. Sygnały bezpieczeństwa przekazują informacje istotne dla zachowania bezpieczeństwa i ochrony zdrowia pracowników, m in. na temat zagrożeń w środowisku pracy (pożar, skażenie), awarii obsługiwanych urządzeń, poruszających się pojazdów itp. Sygnały informacyjne nie mają bezpośredniego wpływu na bezpieczeństwo pracowników, ale poprawiają ich komfort pracy, a niekiedy wręcz umożliwiają jej wykonywanie. Są szczególnie istotne w przypadku pracowników z niepełnosprawnością narządu wzroku. W odniesieniu do osób z niepełnosprawnością słuchu sygnały akustyczne muszą być uzupełnione np. o sygnały świetlne W artykule przedstawiono problematykę oraz wymagania dotyczące sygnalizacji akustycznej w projektowaniu obiektów i pomieszczeń oraz przystosowaniu stanowisk pracy dla osób niepełnosprawnych. Poruszono także kwestię uzupełnienia sygnalizacji akustycznej o sygnalizację świetlną.Auditory signals m the work environment can be divided into information signals and safety signals. Safety signals provide essential information to maintain the safety and health of workers, including risks in the work environment (fire, pollution), failure of deices, moving vehicles, etc. Information signals have no direct impact on the safety of the workers, but improve comfort and even allow to perform some activities. They are particularly important in the case of employees with sight disabilities. For persons with hearing disabilities auditory signals must be complemented by light signals. The article presents the issues and requirements for auditory signals in the design of objects and spaces and adaptation of workstation for people with disabilities The article also raises issues of auditory signals complemented by light signals

Threat posed by impulse noise produced by the industry and during explosions

Hałas impulsowy jest zagrożeniem dla słuchu występującym na wielu stanowiskach pracy, najczęściej związanych z obróbką metali oraz w obecności wystrzałów bądź eksplozji. Należy mieć na uwadze, że w przypadku silnych impulsów istnieje możliwość spowodowania trwałego ubytku słuchu nawet po jednej ekspozycji. W artykule przedstawiono właściwości hałasu impulsowego wytwarzanego przez 37 źródeł hałasu typowych dla przemysłu i zastosowań militarnych. Obliczono też liczbę minut lub dopuszczalną liczbę strzałów/eksplozji, na jakie mógłby być eksponowany pracownik na określonym stanowisku pracy.Impulse noise encountered at workplaces, usually related to either metal processing or gunshots and explosions, is a threat to hearing. It should be noted that strong impulses can induce a hearing loss even if caused by a single exposure. The article discusses properties of impulse noise generated by 37 sources typically found in the industry or at the military. The number of minutes and the admissible number of either gunshots or explosions towards which an employee might be exposed at a certain workstation was calculated and provided

Assessment of Impulse Noise Hazard and the Use of Hearing Protection Devices in Workplaces Where Forging Hammers are Used

The impulse noise is agent harmful to health not only in the case of shots from firearms and the explosions of explosive materials. This kind of noise is also present in many workplaces in the industry. The paper presents the results of noise parameters measurements in workplaces where four different die forging hammers were used. The measured values of the C-weighted peak sound pressure level, the A-weighted maximum sound pressure level and A-weighted noise exposure level normalized to an 8 h working day (daily noise exposure level) exceeded the exposure limit values. For example, the highest measured value of the C-weighted peak sound pressure level was 148.9 dB. In this study possibility of the protection of hearing with the use of earplugs or earmuffs was assessed. The measurement method for the measurements of noise parameters under hearing protection devices using an acoustical test fixture instead of testing with the participation of subjects was used. The results of these measurements allows for assessment which of two tested earplugs and two tested earmuffs sufficiently protect hearing of workers in workplaces where forging hammers are used

Attenuation of Noise by Motorcycle Safety Helmets

For workers such as police motorcyclists or couriers, traffic and engine noise reaching the ears is an important factor contributing to the overall condition of their work. This noise can be reduced with motorcycle helmets. In this study, insertion loss of motorcycle helmets was measured with the microphone-in-real-ear technique and sound attenuation with the real-ear-at-threshold method. Results for 3 Nolan helmets show essentially no protection against external noise in the frequency range 500 Hz, attenuation increases linearly at a rate of 8–9 dB per octave, to ~30 dB at 8 kHz. Lack of attenuation in the low-frequency range may cause annoying effects. In addition, high attenuation in the high-frequency range may decrease intelligibility of speech signals for a rider in a helmet. Attenuation measured in this study does not take into account noise generated by turbulent wind around the helmet. Thus, the measured values of attenuation represent a motorcycle rider’s best conditions of hearing

Attenuation of Noise by Motorcycle Safety Helmets

For workers such as police motorcyclists or couriers, traffic and engine noise reaching the ears is an important factor contributing to the overall condition of their work. This noise can be reduced with motorcycle helmets. In this study, insertion loss of motorcycle helmets was measured with the microphone-in-real-ear technique and sound attenuation with the real-ear-at-threshold method. Results for 3 Nolan helmets show essentially no protection against external noise in the frequency range 500 Hz, attenuation increases linearly at a rate of 8–9 dB per octave, to ~30 dB at 8 kHz. Lack of attenuation in the low-frequency range may cause annoying effects. In addition, high attenuation in the high-frequency range may decrease intelligibility of speech signals for a rider in a helmet. Attenuation measured in this study does not take into account noise generated by turbulent wind around the helmet. Thus, the measured values of attenuation represent a motorcycle rider’s best conditions of hearing

Assessment of Impulse Noise Hazard and the Use of Hearing Protection Devices in Workplaces where Forging Hammers are Used

The impulse noise is agent harmful to health not only in the case of shots from firearms and the explosions of explosive materials. This kind of noise is also present in many workplaces in the industry. The paper presents the results of noise parameters measurements in workplaces where four different die forging hammers were used. The measured values of the C-weighted peak sound pressure level, the A-weighted maximum sound pressure level and A-weighted noise exposure level normalized to an 8 h working day (daily noise exposure level) exceeded the exposure limit values. For example, the highest measured value of the C-weighted peak sound pressure level was 148.9 dB. In this study possibility of the protection of hearing with the use of earplugs or earmuffs was assessed. The measurement method for the measurements of noise parameters under hearing protection devices using an acoustical test fixture instead of testing with the participation of subjects was used. The results of these measurements allows for assessment which of two tested earplugs and two tested earmuffs sufficiently protect hearing of workers in workplaces where forging hammers are used

Effect of Musician’s Earplugs on Sound Level and Spectrum During Musical Performances

In this study, change in A-weighted and 1/3-octave sound pressure levels (SPLs) was used to assess the influence of wearing earplugs by musicians on their musical performances. Seven soloists and 3 music assembles performed 4 pieces of music with musician’s earplugs donned and doffed. They used silicon custom moulded earplugs with acoustic filters designed to attenuate sound by 9, 15 or 25 dB. Results showed that the use of earplugs affected the sound level and the spectrum of played sounds. This effect was the greatest for brass players. The difference between SPLs in high-frequency 1/3-octave bands and A-weighted SPLs with and without earplugs exceeded 5 and 15 dB, respectively. Similar changes for woodwind, percussion and string instruments were less noticeable than for brass instruments; they were more than 5 dB for 1/3-octave spectra and no more than 2 dB for A-weighted SPL

Evaluation of Exposure to Impulse Noise at Personnel Occupied Areas During Military Field Exercises

The tests reported in this paper were carried out to evaluate the exposure of soldiers to noise at operator and control positions during military field exercises. The tests were conducted during firing from a T-72 tank, a BWP-1 Infantry Fighting Vehicle, antitank guided missiles, a ZU-23-2K anti-aircraft gun, and a 2S1 GOZDZIK howitzer. The evaluation of noise exposure showed that the limit values of sound pressure level, referred to by both Polish occupational noise protection standards and the Pfander and Dancer hearing damage risk criteria developed for military applications, were repeatedly exceeded at the tested positions. Despite of the use of tank crew headgear, the exposure limit values of sound pressure level were exceeded for the crew members of the T-72 tank, the BWP-1 infantry fighting vehicle, and the 2S1 GOZDZIK howitzer. The results show that exposure of soldiers to noise during military field exercises is a potentially high hearing risk factor