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Artigos de revistas sobre o assunto "Protective mask 90":
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Dinsmore, Jessica, Susan Brands, Steven Perry, Michael Lopez, Yutong Dong, Daniel Palasz e Jennifer Tucker. "Efficacy of Various Facial Protective Equipment for Infection Control in a Healthcare Setting". Western Journal of Emergency Medicine 22, n.º 5 (17 de agosto de 2021): 1045–50. http://dx.doi.org/10.5811/westjem.2021.3.50516.
Resumo:
Introduction: The coronavirus 2019 (COVID-19) pandemic has reinforced the importance of facial protection against droplet transmission of diseases. Healthcare workers wear personal protection equipment (PPE), including face shields and masks. Plastic face shields may have advantages over regular medical masks. Although many designs of face shields exist, there is a paucity of evidence regarding the efficacy of shield designs against droplet transmissions. There is even less published evidence comparing various face shields. Due to the urgency of the pandemic and the health and safety of healthcare workers, we aimed to study the efficacy of various face shields against droplet transmission. Methods: We simulated droplet transmission via coughing using a heavy-duty chemical spray bottle filled with fluorescein. A standard-adult sized mannequin head was used. The mannequin head wore various face shields and was positioned to face the spray bottle at either a 0°, 45°, or 90° angle. The spray bottle was positioned at and sprayed from 30 centimeters (cm), 60 cm, or 90 cm away from the head. These steps were repeated for all face shields used. Control was a mannequin that wore no PPE. A basic mask was also tested. We collected data for particle count, total area of particle distribution, average particle size, and percentage area covered by particles. We analyzed percent covered by particles using a repeated measures mixed-model regression with Tukey-Kramer pairwise comparison. Results: We used least square means to estimate the percentage area covered by particles. Wearing PPE regardless of the design reduced particle transmission to the mannequin compared to the control. The LCG mask had the lowest square means of 0.06 of all face-shield designs analyzed. Tukey-Kramer pairwise comparison showed that all PPEs had a decrease in particle contamination compared to the control. LCG shield was found to have the least contamination compared to all other masks (P < 0.05). Conclusion: Results suggest the importance of wearing a protective covering against droplet transmission. The LCG shield was found to decrease facial contamination by droplets the most of any tested protective equipment.
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Letowski, T. R., G. L. Ricard e J. E. Greives. "The Effect of the XM45 Gas Mask and Hood on Directional Hearing". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 41, n.º 2 (outubro de 1997): 864–67. http://dx.doi.org/10.1177/107118139704100229.
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We measured listeners' directional sensitivity for narrow bands of noise and for speech recognition while they were wearing the XM45 gas mask and hood and compared it to normal free-field listening. Bekesy tracking was used to measure absolute hearing thresholds for 1/3 octave bands of noise centered at 0.125, 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz. and masked intelligibility thresholds for speech were measured using the Modified Rhyme Test. Both the noise and speech signals were presented from loudspeakers located at azimuths of 0°, 45°, 90°, 135°, and 180°. The mask and hood significantly elevated noise-band thresholds for those bands centered at 1.0 kHz and above. Sensitivity to masked speech was increased by over 12 dB by lateral loudspeaker placement, and wearing a gas mask and hood reduced this gain by 80 percent. These results document a loss of auditory spatial awareness that has not been apparent from previous studies of speech intelligibility while wearing chemical protective equipment.
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Stojić, Mihailo, Ivo Udovičić, Aleksandar Vranjanac, Ana Popadić, Nevena Radović, Daliborka Jaćimović, Katarina Mladenović, Duško Maksimović, Vojislava Nešković e Dušica Stamenković. "Perioperative strategy during pandemic caused by SARS CoV-2 virus: Perioperative strategy during COVID-19 pandemic". Serbian Journal of Anesthesia and Intensive Therapy 42, n.º 1-2 (2020): 49–55. http://dx.doi.org/10.5937/sjait2002049s.
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The main feature of the SARS CoV-2 virus pandemic is the collapse of the health care system due to a large number of patients. This situation requires strict perioperative control of the infection to suppress the transmission of pathogens among surgical patients. Reduction of residual contamination of the working environment requires a combination of deep cleaning with disinfectants and ultraviolet C radiation. Intubation is a high-risk procedure for virus transmission and demands rigorous respect of personal protection for anesthesia providers, including a protective mask (FFP 2, FFP3), two pairs of gloves ("double gloves technique") and goggles, and disinfectant near the anesthesiology team. The workspace needs pre-planning and control of the movement through the so-called "green" and "red" zones. Before surgery, maintaining of patient's hygiene is important - including hair and body washing with antiseptic skin cleanser gel, rinse of the oral and nasal cavity and hand washing. During preoperative preparation, identification of COVID-19 infection is necessary. If the patient is febrile and the test results show the existence of a lung infection, SpO2 ≤ 90% of unknown cause and the operation is not urgent, the anesthesiologist should inform the patient, family, and surgeon that the operation should be postponed. If the patient is tested positive for SARS-CoV-2, elective surgery is delayed until the complete recovery of the patient, which includes a negative test and recovery from COVID-19. Patient should recover in the operating room after extubation. The surgical mask should be placed over an oxygen mask. Patient is transported with a surgical mask on his face to the ward directly.
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Madu, Victory C., Heather Carnahan, Robert Brown, Kerri-Ann Ennis, Kaitlyn S. Tymko, Darryl M. G. Hurrie, Gerren K. McDonald, Stephen M. Cornish e Gordon G. Giesbrecht. "Skin Cooling on Breath-Hold Duration and Predicted Emergency Air Supply Duration During Immersion". Aerospace Medicine and Human Performance 91, n.º 7 (1 de julho de 2020): 578–85. http://dx.doi.org/10.3357/amhp.5433.2020.
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PURPOSE: This study was intended to determine the effect of skin cooling on breath-hold duration and predicted emergency air supply duration during immersion.METHODS: While wearing a helicopter transport suit with a dive mask, 12 subjects (29 ± 10 yr, 78 ± 14 kg, 177 ± 7 cm, 2 women) were studied in 8 and 20°C water. Subjects performed a maximum breath-hold, then breathed for 90 s (through a mouthpiece connected to room air) in five skin-exposure conditions. The first trial was out of water for Control (suit zipped, hood on, mask off). Four submersion conditions included exposure of the: Partial Face (hood and mask on); Face (hood on, mask off); Head (hood and mask off); and Whole Body (suit unzipped, hood and mask off).RESULTS: Decreasing temperature and increasing skin exposure reduced breath-hold time (to as low as 10 ± 4 s), generally increased minute ventilation (up to 40 ± 15 L · min−1), and decreased predicted endurance time (PET) of a 55-L helicopter underwater emergency breathing apparatus. In 8°C water, PET decreased from 2 min 39 s (Partial Face) to 1 min 11 s (Whole Body).CONCLUSION: The most significant factor increasing breath-hold and predicted survival time was zipping up the suit. Face masks and suit hoods increased thermal comfort. Therefore, wearing the suits zipped with hoods on and, if possible, donning the dive mask prior to crashing, may increase survivability. The results have important applications for the education and preparation of helicopter occupants. Thermal protective suits and dive masks should be provided.Madu VC, Carnahan H, Brown R, Ennis K-A, Tymko KS, Hurrie DMG, McDonald GK, Cornish SM, Giesbrecht GG. Skin cooling on breath-hold duration and predicted emergency air supply duration during immersion. Aerosp Med Hum Perform. 2020; 91(7):578–585.
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Mijakoski, Dragan, Sasho Stoleski, Dragana Bislimovska, Elena Pazheska-Dimitrioski, Elizabeta Karasmanakis, Jordan Minov e Jovanka Karadzinska-Bislimovska. "Personal Protective Equipment in Health Workers during Coronavirus Disease-19 Outbreak". Open Access Macedonian Journal of Medical Sciences 8, T1 (25 de dezembro de 2020): 634–41. http://dx.doi.org/10.3889/oamjms.2020.5621.
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BACKGROUND: Coronavirus (CoV) disease (COVID)-19 pandemic has put immense pressure on the healthcare systems worldwide.
AIM: The aim of the actual study was to assess the availability of personal protective equipment (PPE) in health workers (HWs) during an outbreak.
METHODS: The study was conducted in April-May 2020 using an on-line questionnaire. Completed surveys were returned by 560 HWs (297 physicians, 79 nurses/technicians, 78 dentists, 9 pharmacists, and 97 other HWs).
RESULTS: High proportion of HWs was using one surgery mask for two or more times or not using it at all when contacting patients who were self-isolated (35.3%) or severe acute respiratory syndrome CoV (SARS-CoV)-2 positive (19.3%). More than 90% of participants were using surgery masks and gloves every time or almost every time while working with patients who were self-isolated or SARS-CoV-2 positive. High frequency of participants reported: No isolation zones at the workplace (61.2%), no triage of patients at the entrance (33.4%), and not attended a training course about the correct usage of PPE (72%).
CONCLUSION: The data obtained can be used in the creation of specific interventions in healthcare settings aimed at providing high-quality PPE through the development of a national healthcare strategy that can lead to the prevention of COVID-19 in HWs.
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Gupta, Kalika, Mitin Parmar, Pranav Bhavsar e Milan Chaudhary. "An Analytical Study Carried Out to Identify Symptoms of Occupational Lung Diseases and Preventive Measures among Workers Involved in Marble Industries in Rajsamand District of Rajasthan". Journal of Evidence Based Medicine and Healthcare 8, n.º 02 (11 de janeiro de 2021): 53–57. http://dx.doi.org/10.18410/jebmh/2021/11.
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BACKGROUND Occupational lung diseases are diseases affecting the respiratory system, including occupational asthma, black lung disease and many more. Workers exposed to marble dust stand an increased risk of suffering from asthma symptoms, chronic bronchitis, nasal inflammation and impairment of lung functions. The recognition of occupational causes can be made difficult by years of latency between exposure in the workplace and the occurrence of disease. Through this study, authors have established the importance of early identification of symptoms of occupational lung diseases and the importance of preventive measures that can be applied to reduce incidence of such diseases. METHODS This was a cross sectional community-based study conducted on 340 marble mining or cutting workers of Rajnagar [Morwar], Rajsamand district of Rajasthan, for a duration of three months. Workers were clinically examined and asked about environmental conditions and use of preventive measures through a questionnaire designed by the investigators and with the help of pamphlets and videos, educational interventions were provided. RESULTS Almost 90 % of the workers didn’t use protective measure like mask or shield. Among the 10 % workers who were using safety measures, 60 % were using face mask and 20 % were using apron at the work place. After the educational intervention given by investigators, around 63 % had started using various safety measures. CONCLUSIONS Early interventions after development of symptoms are important as they can decrease chances of further worsening of the condition. Health education, periodic health check-ups and use of protective measures are the essence in preventing occupational lung diseases. KEYWORDS Occupational Lung Disease, Cough, Marble Workers, Silicosis
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AlSarheed, Maha. "Children’s Perception of Their Dentists". European Journal of Dentistry 05, n.º 02 (abril de 2011): 186–90. http://dx.doi.org/10.1055/s-0039-1698878.
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ABSTRACTObjectives: The aim of this study was to assess school children’s feelings and attitudes toward their dentist. Methods: A questionnaire designed to evaluate children’s attitudes and preferences toward dentists was completed by 583 children (289 females, 294 males) with age range 9-12 years attending public schools. Results: 76% of the children who completed the questionnaire reported that they had been to the dentist before. Of the children who had visited the dentist, approximately 64% reported liking their visit, 11% didn’t like their visit, and 12% were afraid. 90% of the children preferred their dentist to wear a white coat, while 40% preferred them to wear a mask and protective eye glasses as protective measures during treatment. When asked to choose between two pictures of different clinical settings, 63% of the children indicated that they preferred a decorated dental clinic over a plain clinic. Fear of local anesthesia and tooth extraction were the most common reasons cited for not liking dental treatment. Conclusions: Children have strong perceptions and preferences regarding their dentists. Data collected for this study can be used by dentists to improve delivery of care. (Eur J Dent 2011;5:186-190)
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Monteiro, Camila Gonçalves Jezini, Mariana Martins e. Martins, Adriana de Alcantara Cury-Saramago e Henry Pinheiro Teixeira. "Biosafety conducts adopted by orthodontists". Dental Press Journal of Orthodontics 23, n.º 3 (junho de 2018): 73–79. http://dx.doi.org/10.1590/2177-6709.23.3.073-079.oar.
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ABSTRACT Objective: This cross-sectional observational study was designed to assess the biosafety conducts adopted by orthodontists, and possible differences regarding training time. Methods: Both the application of methods for sterilization/disinfection of instruments and materials, and the use of personal protective equipment (PPE) were collected through questionnaires via e-mail. Results: The questionnaires were answered by 90 orthodontists with a mean age of 37.19 ± 9.08 years and mean training time of 13.52 ± 6.84 years. Regarding orthodontic pliers, 63.23% use an autoclave, except 1 who does not perform any procedure. All participants use autoclave to sterilize instruments, and 95.6% of respondents perform cleaning with chemicals prior to sterilization. Most of them (65.56%) use an autoclave to sterilize orthodontic bands, with some still associating disinfection methods, while few (18.89%) do nothing at all. There was a high incidence of the answer “nothing” for the methods used for elastic, accessories, bandages, metal springs, and arches. All respondents use mask and gloves in attendance, 78.92% use aprons, 58.92% use protective goggles, and 50.01% use cap. Training time significantly influenced (p = 0.003) only the use of glutaraldehyde for sterilization/disinfection of pliers. Conclusions: The sterilization and cleaning of pliers, instruments, and bands, besides the use of PPE, received more uniform and positive responses, while other items suggest disagreements and possible failures. Only orthodontists trained for more than 13 years choose using glutaraldehyde for pliers sterilization/disinfection, the only adopted method with a significant difference in relation to training time.
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Bayraktar-Ekincioglu, Aygin, Gamze Korubük e Kutay Demirkan. "An evaluation of chemotherapy drug preparation process in hospitals in Turkey – A pilot study". Journal of Oncology Pharmacy Practice 24, n.º 8 (20 de julho de 2017): 563–73. http://dx.doi.org/10.1177/1078155217720007.
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Objective To identify the practice differences among chemotherapy units and the opinions of pharmacists on safety precautions for handling antineoplastic drugs in hospitals. Method The survey was administered to hospital pharmacists in Turkey. The pharmacists who work in chemotherapeutic drug preparation units were asked to participate if they are volunteered. The participating pharmacists were asked questions about the type of chemotherapy units, order and verification process of chemotherapy protocols and potential shortcomings of chemotherapy preparation. The questions were initially assessed in a small sample of pharmacists and subsequently revised and refined. The filled and returned questionnaires were accepted as given consent. Results A total of 97 questionnaires were delivered and 40 (41%) were returned by pharmacists. The median age and practicing years in hospitals of the pharmacists were 38.0 and 6.25 years, respectively. Fully automated chemotherapy units were used by 42.5% of respondents, whereas 30% prepare chemotherapeutics manually; furthermore, 87.5% provide chemotherapeutic drug preparations (admixtures) less than 120 per day. With regard to the drug preparation process, more than half of the respondents ‘always’ use protective equipment without foot covers (32.3%). Almost 90% of respondents ‘always’ use a coat, mask and biological safety cabinets; however, 20% of respondents ‘often’ use closed-system drug transfer sets. More than 50% of pharmacists expressed that they have sufficient knowledge on cytotoxics and the risk of exposure, protective precautions, selection and usage of personal protective equipment and correct storage of cytotoxics. Conclusion Pharmacists acknowledge sufficient understanding of safe preparation and handling of chemotherapeutics, but reported practices by pharmacists in hospitals are not consistent with published recommendations. Providing theoretical and practical educations for pharmacists and developing standard procedures for preparing chemotherapy may be beneficial in improving the preparation and use of antineoplastics in Turkey.
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Achsar, Aulia Martyana, e Arie Zainul Fatoni. "Manajemen Pasien Dekstroskoliosis Berat dengan Kegagalan Napas yang disebabkan oleh Syok Septik dan Pneumonia". Journal of Anaesthesia and Pain 2, n.º 1 (31 de janeiro de 2021): 40–47. http://dx.doi.org/10.21776/ub.jap.2021.002.01.05.
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Latar belakang: Dekstroskoliosis adalah jenis skoliosis dengan deformitas kurva tulang belakang ke kanan. Dekstroskoliosis berat dengan Cobbs Angle > 70o mengakibatkan berkurangnya kapasitas paru, Functional Residual Capacity (FRC), volume tidal, dan mempunyai kondisi seperti penyakit paru restriktif. Pada kondisi berat dapat menyebabkan hipoksemia, hiperkapnia dan gagal napas. Penyebab tersering gagal napas pada pasien dekstroskoliosis berat ialah sepsis/syok septik yang disebabkan oleh pneumonia. Sampai saat ini belum ada tatalaksana khusus yang menjelaskan tentang manajemen pasien dekstroskoliosis berat dengan gagal napas yang disebabkan syok septik dan pneumonia. Kasus: Pria berusia 46 tahun dengan berat badan 40 kg dan tinggi badan 165 cm rujukan dari Rumah Sakit luar dengan riwayat sesak napas dan kehilangan kesadaran sejak satu minggu sebelumnya, masuk ke Instalasi Gawat Darurat dengan laju pernapasan 40 x/menit, dengan menggunakan Nonrebreathing Mask 15 lpm saturasi oksigen terukur hanya 90% dengan tekanan darah 60/40 mmHg dan laju nadi 120 x/menit. Pasien memiliki riwayat batuk dengan dahak kuning dan demam sekitar 1 bulan. Pasien dinilai sebagai gagal napas dengan dekstroskoliosis berat dan penyulit syok septik dan Community Acquired Pneumonia, kami lakukan tindakan intubasi dan resusitasi sesuai sepsis bundle terbaru, pasien kemudian kami rawat di Intensive Care Unit (ICU) selama 10 hari dengan bantuan ventilasi mekanik invasif dengan menggunakan prinsip Lung protective strategy dan Survival Sepsis Campaign Bundle terbaru, hari ke 11 pasien stabil bisa lepas dari ventilator dan dipindahkan ke bangsal. Kesimpulan: Lung protective strategy dan Survival Sepsis Campaign Bundle dapat digunakan untuk manajemen pasien dekstroskoliosis berat dengan gagal napas yang disebabkan syok septik dan pneumonia.
Teses / dissertações sobre o assunto "Protective mask 90":
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Gustafsson, Rebecca, e Anneli Wuotila. "Intensivvårdssjuksköterskors erfarenheter av kommunikation vid användning av skyddsmask 90 i vården av patienter med covid-19". Thesis, Luleå tekniska universitet, Institutionen för hälsa, lärande och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-85819.
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Bakgrund: Bristande kommunikation är en faktor som påverkar patientsäkerheten negativt inom hälso- och sjukvården. Personlig skyddsutrustning som till exempel skyddsmask 90, används av intensivvårdssjuksköterskor under covid-19 pandemin. Personlig skyddsutrustning såsom skyddsmask 90 har visat sig dämpa ljudnivån på verbal kommunikation, samtidigt som kommunikation genom ansiktsuttryck försvinner helt. Syfte: Syftet med studien var att undersöka intensivvårdssjuksköterskors erfarenheter av kommunikation vid användning av skyddsmask 90 i vården av patienter med covid-19. Metod: Denna studie är en kvalitativ intervjustudie, där rekrytering av deltagare genomförts med ett ändamålsenligt urval. Analysen utfördes induktivt med en manifest ansats. Resultat: I resultatet framkom fyra huvudkategorier. Huvudkategorierna: Att kommunikationen försvåras, att skapa förutsättningar för en bättre kommunikation, att upprätthålla patientsäkerheten, att anpassa sig till arbete i skyddsmask 90. Faktorer som försvårar kommunikationen är att ljudnivån vid samtal blir lägre än normalt. För intensivvårdssjuksköterskorna blir det svårare att lugna och trösta patienterna, då de har svårare att höra och förstå vad som sägs när personalen använder skyddsmask 90. Det som främjar kommunikationen är närhet till patienten, samt en tydlig och strukturerad kommunikation. Patientsäkerheten kan upprätthållas genom att använda vedertagna kommunikationsmodeller vid samtal såsom closed-loop och SBAR, men även genom att fråga för att vara säker på att rätt saker uppfattades. Efter en tillvänjningstid i skyddsmask 90 är det möjligt att upprätthålla en adekvat kommunikation. Slutsatser: För att säkerställa en god kommunikation kan användare av skyddsmask 90 använda sig av kommunikationsverktyg, prata nära, tydligt och endast om relevanta saker. Genom att säkerställa en god kommunikation upprätthålls även en god patientsäkerhet.
Capítulos de livros sobre o assunto "Protective mask 90":
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"§ 2. Statutory regulations and their interrelationship". In International Trade Mark and Signs Protection, editado por Paul Lange, 90–91. Nomos, 2010. http://dx.doi.org/10.5771/9783845266404-90.
Trabalhos de conferências sobre o assunto "Protective mask 90":
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Tsisar, Valentyn, Carsten Schroer, Olaf Wedemeyer, Aleksandr Skrypnik e Jürgen Konys. "Corrosion of 9% Cr Ferritic/Martensitic Steels in Flowing Pb-Bi Eutectic With 10−7 Mass% Dissolved Oxygen at 450 and 550 °C". In 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60826.
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Corrosion behavior of 9 %Cr ferritic/martensitic (F/M) P92, E911 and EUROFER steels was investigated in flowing (2 m/s) Pb-Bi with 10−7 mass%O at 450 and 550 °C for up to 8766 and 2011 h, respectively. The steels show mixed corrosion modes simultaneously revealing protective scaling, accelerated oxidation and solution-based attack. At 450 °C, the accelerated oxidation resulted in a metal recession averaging 6 μm (± 2 μm) after ∼8766 h while local solution-based corrosion attack ranged from ∼40 to 350 μm. At 550 °C, the accelerated oxidation resulted in a metal recession of about 10 μm (± 2 μm) after ∼2011 h. Solution-based corrosion attack appears more regularly at 550 °C, with a maximum depth ranged from ∼90 to 1000 μm. Incubation time for solution based attack is 500–2000 h for 450 °C and < 300 h for 550 °C. The EUROFER steel showed more severe metal recession via both oxidation and solution-based corrosion in comparison with P92 and E911 steels. The possible effect of alloying and structure on the corrosion response of 9 %Cr F/M steels is discussed.
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Andrews, G. E., I. M. Khalifa, A. A. Asere e F. Bazdidi-Tehrani. "Full Coverage Effusion Film Cooling With Inclined Holes". In ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/95-gt-274.
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Effusion cooling with 15 film cooling rows of holes was investigated and a comparison of normal and inclined holes was undertaken for laser drilled holes. Overall and adiabatic cooling effectiveness data are presented for a density ratio of 2.5 for N=9688 holes per square metre and an X/D of 11. The main variable studied was the angle of inclination of the 30° film holes to the crossflow, 30°, 90° and 150°. Comparison was made with 90° holes of similar X/D and a smaller X/D of 4.5, which was shown to be as effective as inclining the holes for improving the cooling effectiveness. The opposed film cooling flow of the 150° inclined hole was very effective in providing a good film protection at the leading rows of holes. A cooling effectiveness of 0.7 was demonstrated at a mass flow per unit surface area G of 0.35–0.4 kg/sm2 bar with both 30° and 150° holes. This was equivalent to 15–20% of the combustor air flow for a typical gas turbine combustor. Comparison with previous work on effusion cooling showed reasonable agreement for similar geometries, although very few previous workers have reported overall cooling effectiveness results. Also the present work covered a much wider range of film cooling mass flow, a larger number of rows of holes and a more practical density ratio than in previous work.
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"Magnetic Pre-Loading for a Tonpilz-Type Acoustic Projector". In Structural Health Monitoring. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901311-1.
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Abstract. This paper describes a new magnet-based method for applying a compressive pre-load to the piezoceramic elements of a Tonpilz-type acoustic projector, with the advantage of lower damping due to mechanical friction and a greater range of unhampered resonant motion since no plate spring is required. The Tonpilz-type acoustic projector can be applied to structural health monitoring studies involving air coupled ultrasound. Acoustic model predictions and the measured behaviour of a relaxor ferroelectric single crystal (RFSC) based prototype device, operating in air, are presented and show good correlation. With a 5 V drive, at 9420 Hz resonance, the prototype device generates a sound pressure level of 113 dB measured at an axial distance of 5 mm. The maximum peak tip displacement of the device’s head mass is predicted to be 0.7 µm at resonance. This is well within the 2 µm displacement produced by the 90 N magnetic pre-load, thus protecting the RFSC ceramic element from damaging tensile stress.
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Thakare, Ketan, Laura Jerpseth, Hongmin Qin e Zhijian Pei. "Preliminary Investigation of Removing Copper Contamination From Water Using Algae". In ASME 2020 15th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/msec2020-8521.
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Abstract Drinking water contaminated with metal ions can cause negative health effects in humans. Acute heavy metal poisoning can cause such symptoms as vomiting and fainting, while chronic heavy metal poisoning can lead to organ failure and death. It has previously been shown that concentration of metal ions in water solution was decreased by algae. This paper reports a study to examine the ability of two Chlamydomonas reinhardtii algae strains to remove copper ions from water solution. Chlamydomonas reinhardtii was chosen for this study because it is easy to culture, and can be used to generate strains with a higher efficiency to remove metals. In this study, the three-factor, two-level full factorial design was used to conduct experiments. Three factors were algae strain, initial copper concentration, and exposure time. Two levels of the algae strain are: cc125 — the Chlamydomonas reinhardtii strain found commonly in the wild, and AGG1 — an experimentally modified Chlamydomonas reinhardtii strain. Two levels of initial copper concentration and exposure time were 1.5 and 3 ppm, and 2.5 and 5 hours, respectively. Copper concentration in the water solution after experiments was measured using inductively coupled plasma-mass spectrometry, or ICP-MS. Statistical analysis showed that algae strain was the only factor that significantly affected percentage decrease in copper concentration, at the significance level of 0.05. The cc125 strain decreased copper concentration more efficiently than the AGG1 strain. The cc125 strain decreased copper concentration by 97% for the water solution with an initial copper concentration of 1.5 ppm, and by 90% for the solution with an initial copper concentration of 3 ppm. Copper concentrations of all solutions treated by the cc125 strain were below the Environmental Protection Agency pollution threshold level of 1.3 ppm.
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Zhang, Yang, e Xin Yuan. "Turbine Endwall Film Cooling With Pressure Side Radial Holes". In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95273.
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A key technology of gas turbine performance improvement was the increase in the turbine inlet temperature, which brought high thermal loads to the nozzle guide vane (NGV) components. Strong pressure gradients in the NGVs and the complex secondary flow field had made thermal protection more challenging. As for the endwall surface near the side gill pressure region, the relatively higher local pressure and cross flow apparently decreased the film-cooling effectiveness. The aim of this investigation was to evaluate a new design, improving the film-cooling performance in a cooling blind area with radial cylindrical holes on the pressure side. The test cascades model was manufactured according to the GE-E3 nozzle guide vane scaled model, with a scale ratio of 2.2. The experiment was performed under the inlet Mach number 0.1 and the Reynolds number 3.5×105 based on an axial chord length of 78 mm. Four rows of staggered radial film-cooling holes were placed at the pressure side gill region. The diameter of the cylindrical holes was 1 mm and the length was 5 d, with a hole space of 6 d. The spanwise angle of the cooling holes was 35 ° and the radial angle was 90 °. Three blowing ratios were chosen as the test conditions in the experiment, M = 0.7, M = 1.0 and M = 1.3. The film-cooling effectiveness was probed using PSP (pressure sensitive painting) technology and the post processing was performed by means of a mass and heat transfer analogy. Through the investigation, the following results could be achieved: 1) the film-cooling effectiveness on the endwall surface near the pressure side gill region increased, with the highest parameter at X/Cax = 0.3; 2) a double-peak cooled region developed towards the suction side as the blowing ratio increased; 3) the advantage of the pressure side radial cooling holes was apparent on the endwall surface near the gill region, while the coolant film was obviously weakened along the axial chord at a low blowing ratio. The influence of the pressure film cooling could only be detected in the downstream area of the endwall at the higher blowing ratio.