Failures of Mechanical Fasteners

2021 ◽  
pp. 379-401
Author(s):  
Michael B. Connelly
Keyword(s):  
Environmental Effects ◽  
Elevated Temperatures ◽  
Preventive Measures ◽  
Threaded Fasteners ◽  
Common Causes ◽  
Mechanical Fasteners ◽  
Improper Use

Abstract This article first provides an overview of the types of mechanical fasteners. This is followed by sections providing information on fastener quality and counterfeit fasteners, as well as fastener loads. Then, the article discusses common causes of fastener failures, namely environmental effects, manufacturing discrepancies, improper use, or incorrect installation. Next, it describes fastener failure origins and fretting. Types of corrosion in threaded fasteners and their preventive measures are then covered. The performance of fasteners at elevated temperatures is addressed. Further, the article discusses the types of rivet, blind fastener, and pin fastener failures. Finally, it provides information on the mechanism of fastener failures in composites.

scholarly journals Influence of sexually transmitted infections in a horse breeding

2015 ◽  
Vol 69 (5-6) ◽  
pp. 443-452
Author(s):  
Marjan Kosec ◽  
Natasa Sterbenc ◽  
Janko Mrkun ◽  
Igor Klobucar ◽  
Primoz Klinc
Keyword(s):  
Risk Factors ◽  
Sexually Transmitted Diseases ◽  
Artificial Insemination ◽  
Clinical Picture ◽  
Preventive Measures ◽  
Sexually Transmitted ◽  
Direct Damage ◽  
Horse Breeding ◽  
Common Causes ◽  
Infectious Etiology

The most frequent problems in horses reproduction are generally divided into those of infectious and non infectious etiology. Common causes of infectious diseases are usual?ly viruses and bacteria, and less frequently protozoa, mykoplasma and fungi. In this work there are presented the most important fact about sexually transmitted diseases, their clinical picture, risk factors, preventive measures as well as measures to prevent and eradicate the diseases. The biggest risk factor for sexually transmitted diseases in horses are breeding stallions, both in natural mating and in artificial insemination. Therefore, in order to prevent genital infections in horses, it is essential that the stallions used for breeding are healthy (non-infected). That can be determined with certainty only if the stallions are examined (tested) just before the breeding season on most frequent sexually transmitted diseases (CEM,EAV). It is well known that in most cases the clinical picture of sexually transmitted diseses is not manifested on genitals. As well, variations in clinical picture can be expected also in mares, depending on the stage of the disease and its etiology. Harms arising from sexually transmitted diseases can be divided into direct and indirect. Direct damage occurs in the form of endometritis, miscarriage, stillbirths and births of weak foals, and indirect in restricting the traffic of infected and suspicios animals, isolation of the infected ones as well as medical treatment and interrupting mating.

scholarly journals Evaluasi Penggunaan Antibiotik pada Pasien Infeksi Saluran Kemih di Instalasi Rawat Inap RSUP X di Klaten Tahun 2017

2019 ◽  
Vol 16 (1) ◽  
pp. 38-48
Author(s):  
Nawang Nawakasari ◽  
Ambar Yunita Nugraheni
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Data Retrieval ◽  
Antibiotic Use ◽  
Number Of Patients ◽  
Common Causes ◽  
Exact Evaluation ◽  
Improper Use ◽  
The Right ◽  
Tract Infections

Urinary tract infections are infections are characterized by the presence of bacteria that grow and multiply in the urinary tract in excess of the normal amount. Based on the Indonesian Health Profile, urinary tract infections (UTI) are the 10 most common causes of death. Improper use of antibiotics can cause no therapeutic effect and resistance. This study aims to evaluate the accuracy of antibiotic use in patients with urinary tract infections in central hospital Klaten in 2017 covers the right indication, right patient, right medication, and right dosage. Research with non-experimental methods of data retrieval retrospectively and analyzed descriptively. The inclusion criteria in this study were adult patients 18-64 years old, inpatients suffering from urinary tract infections including cystitis and pyelonephritis, receiving antibiotics and complete medical record data. The results showed that patients with urinary tract infections in RSUP in Klaten 2017 had 72 patients with 76 antibiotic prescriptions. Based on the number of patients, the evaluation results showed the right indication is 100% and the right patients is 100%, while the exact evaluation results of the right drug is 96.05% and the right doses is 27,63%.

Fatigue and Fracture Estimation for Metallic Components: Some Current Methods and Future Developments

1995 ◽  
Vol 117 (B) ◽  
pp. 121-127
Author(s):  
D. V. Nelson ◽  
Sheri D. Sheppard
Keyword(s):  
Recent Work ◽  
Environmental Effects ◽  
Fracture Behavior ◽  
Elevated Temperatures ◽  
Metallic Alloys ◽  
Future Developments ◽  
Fatigue And Fracture ◽  
Mechanical Components

Current approaches widely used in fatigue and fracture evaluations of mechanical components are summarized. Metallic alloys, and fatigue and fracture behavior in the absence of environmental effects such as corrosion or elevated temperatures, are considered. Certain shortcomings in the approaches are then discussed, followed by samples of recent work to improve the capabilities to make fatigue and fracture assessments. Finally, future developments that could further enhance those capabilities are suggested.

Fatigue and Fracture Estimation for Metallic Components: Some Current Methods and Future Developments

1995 ◽  
Vol 117 (B) ◽  
pp. 121-127 ◽  
Author(s):  
D. V. Nelson ◽  
Sheri D. Sheppard
Keyword(s):  
Recent Work ◽  
Environmental Effects ◽  
Fracture Behavior ◽  
Elevated Temperatures ◽  
Metallic Alloys ◽  
Future Developments ◽  
Fatigue And Fracture ◽  
Mechanical Components

Current approaches widely used in fatigue and fracture evaluations of mechanical components are summarized. Metallic alloys, and fatigue and fracture behavior in the absence of environmental effects such as corrosion or elevated temperatures, are considered. Certain shortcomings in the approaches are then discussed, followed by samples of recent work to improve the capabilities to make fatigue and fracture assessments. Finally, future developments that could further enhance those capabilities are suggested.

THE HARMFUL COMPLICATIONS OF PERIPHERAL NERVES IN NEUROSURGICAL PRACTICE

Vestnik ◽  
2021 ◽  
pp. 131-135
Author(s):  
Е.К. Дюсембеков ◽  
А.Р. Халимов ◽  
И.Т. Курмаев ◽  
А.В. Николаева ◽  
А.С. Жайлаубаева ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Sciatic Nerve ◽  
Peripheral Nerves ◽  
Preventive Measures ◽  
Nerve Injuries ◽  
Absolute Value ◽  
Iatrogenic Injuries ◽  
Common Causes ◽  
Working Age ◽  
Late Referral

Проведено исследование 93 пациентов с ятрогенными повреждениями периферических нервов, 11,7% по отношению ко всем оперированным пациентам. Женщин было 51, мужчин 42. Пациенты трудоспособного возраста составили 88%. Позднее обращение за специализированной нейрохирургической помощью составило 53,7%. Чаще всех повреждался седалищный нерв - 29,1%, затем лучевой нерв - 22,6%. Наиболее частые причины ятрогенных осложнений - это операции на опорно-двигательном аппарате (79 - 84,9%). Представлены виды оперативных вмешательств, предложены меры по профилактике и своевременному специализированному лечению больных с ятрогенными повреждениями нервов. Research has been done of 93 patients with iatrogenic injuries of peripheral nerves. It amounted to 11,7 per cent of all patients, who received surgical treatment. In the absolute value, there were 51 men and 42 women in gender equivalent. The significant quantity of working age patients amounts to 88%. 53.7% - it is late referral to specialized neurosurgical care. The volume of sciatic nerve injuries was the largest and amounted to 29,1%, the next a radial nerve - 22,6%. Most common causes of harmful complications there are operations on the musculoskeletal system (79 - 84,9%).The article shows the types of surgery, preventive measures and timely specialized treatment of patients with iatrogenic nerve injuries were proposed

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Observations oh Nucleation and Growth of Voids in Nickel

1970 ◽  
Vol 28 ◽  
pp. 414-415
Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel
Keyword(s):  
High Purity ◽  
Growth Stage ◽  
Elevated Temperatures ◽  
Early Growth ◽  
Nucleation And Growth ◽  
Pure Nickel ◽  
Different Temperatures ◽  
Total Fluence ◽  
Neutron Exposure ◽  
Growth Of Voids

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.

Voids in Irradiated Tungsten and Molybdenum

1969 ◽  
Vol 27 ◽  
pp. 190-191
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd
Keyword(s):  
Melting Point ◽  
Fast Neutron ◽  
Neutron Irradiation ◽  
Elevated Temperatures ◽  
Irradiation Temperature ◽  
The Body ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

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