Investigations of The Hybrid Effects of The Operational Parameters In The Radial Forging Process Based On The Validation of The Hardness Test

In this study, considering all the parameters in radial forging and a three-dimensional model has been simulated using the finite element method. By implementing an elastoplastic state for the specimen tube, parameters such as friction type, residual stress distribution, effective strain distribution, material flow velocity and its effect on the neutral plate and the distribution of force in the die have been studied and analyzed. The effects of angle on the quality and characteristics of the specimen and the longevity of the die have also been obtained. Experimental results have been used to confirm the accuracy of the simulation. The results of the hardness test after forging were compared with the simulation results. Good agreement between the results indicates the accuracy of the simulation in terms of hardness. Therefore, this validation allows confirming the other obtained results for the analysis and prediction of various components in the forging process. After the validation and confirmation of the results through the hardness test, the hardness distribution was obtained by considering temperature changes and the effective strain on the specimen.

Solution Densities and Estimated Total Protein Contents Associated With Inappropriate Flotation of Separator Gel in Different Blood Collection Tubes

Context.—Clinical samples that have densities greater than that of separator gel in specimen tubes may exhibit gel flotation to the top of the specimen upon centrifugation. Inappropriate separator gel flotation can occur in specimens with high protein content. In automated analytical systems, gel flotation can lead to mechanical disruption and potential inaccurate result reporting upon aspiration into instrument sampling probes. Objective.—To determine the relative specimen densities and estimated total protein contents at which specimen gel flotation would occur upon centrifugation in commonly used commercial specimen tubes, a comparative study of separator gel density was initiated using prepared dextran solutions. Design.—Specific gravity of several dextran solutions was determined by direct hydrometry. The dextran solutions were introduced to serum and plasma lithium heparin BD Vacutainer specimen tubes manufactured by Becton, Dickinson and Company and into Vacuette specimen tubes manufactured by Greiner Bio-One containing separator gel. Following centrifugation the specimen tubes were examined for gel flotation. Results.—Flotation was observed at a lower dextran solution density for Greiner than for BD tubes in both serum and plasma separator gel specimen tubes. Additionally, some differences between specimen tube lots were observed for both BD and Greiner tubes. The total protein content in clinical samples that would result in gel flotation can be estimated for different specimen container types. Conclusions.—Differences were observed for the gel separator specific gravity in different blood collection containers. Laboratories wishing to avoid problems with inappropriate gel flotation in high protein samples should consider these observations.

endangered sounds: a sound project

endangered sounds is a project that focuses on the exploration of sound marks (trade-marked sounds). the initial stage of this project was funded by arts victoria, and comprised legal searches that resulted in the listings of sound marks registered in australasia and the united states of america. this list was published on the internet with a call for volunteers to collect samples of the listed sounds internationally. the volunteer was sent a specimen tube with label and cap, and asked to collect the sound by placing the specimen tube close to the source (thereby capturing the air through which the sound travelled), securing the cap and then completing the label, documenting the time, place and nature of the sound (sound mark reg. no., sound mark description, time of capture, date of capture, location, etc.). these specimen tubes were collected and displayed in chemistry racks in the exhibition in the biennale of electronic arts, perth in 2004, illustrating the frequency and diversity of the environment into which these ‘private’, protected sounds have been released. the exhibition project consisted of:(1) a web portal listing all the sound marks listed in australasia and the usa, and negotiations are underway to expand that to include the eu.(2) a collection of sound marks in specimen tubes with caps and labels gathered internationally by people who volunteered to collect samples of sound marks in their environment.(3) a number of glass vacuum desiccator vessels containing a small loudspeaker and sound reproduction chip suspended in a vacuum, reproducing sound marks in the vacuum, notionally breaking the law, but as sound does not travel in a vacuum the gallery visitor hears no sound – what then is the jurisdiction of the sound mark?(4) a card index register of lost and deceased sounds.this project questions the legitimacy of privatising and protecting sounds that are released at random in public spaces. if i own a multi-million dollar penthouse in a city, and work night shifts, i have no recourse against the loud harley davidson or australian football league (afl) siren that wakes me from my precious sleep – both sounds are privately protected, making their recording, reproduction and broadcast illegal.while there are legal mechanisms for protection against repeat offenders, and many of us are committed to a culturally conditioned moral obligation re sound dispersion, there are no legal limits – i can call the police, but the football siren is already within legal standards and still permeates the private domain of city dwellings. the noise abatement legislation is only applicable to regular breaches of the law, and takes some time to sort out, but it does not apply to singular occurrences which, although within legislated limits, still disturb. additionally, the laws are based on amplitude and do not really address the issue of propagation. the ownership of the sound is not addressed in these legislative mechanisms – it should be; if the sound is an emblem of corporate identity, we should be able to choose not to be exposed to it, in the same way that we can place a ‘no junk mail’ sign on our letter boxes. acknowledgement of the private domain is sacrosanct in other areas of legislation, in fact heavily policed, but not addressed in discussions of the acoustic environment beyond amplitude limitations.

Factitious Meningitis: A Recurring Problem

Although gram-negative meningitis is rare in our hospital, between July, 1982 and July, 1983 clusters of cerebrospinal fluid (CSF) smears were reported positive for gram-negative bacilli. Fourteen specimens were obtained by diagnostic lumbar punctures, and one was obtained during a myelogram. No CSF cultures were positive, and a diagnosis of factitious meningitis was eventually established for each patient. Nonviable gram-negative bacilli were found in 6.7% of manometers, and 23.3% to 90% of the specimen tubes tested from the same lots of commercial lumbar puncture trays. It was estimated that there were between 44 and 333 organisms per specimen tube. Two lots of the commercial myelogram trays yielded nonviable gram-negative bacilli from 50% of the specimen tubes and 33.3% of the manometers tested. Retrospective review of laboratory records for 1982 and 1983 revealed 23 total CSF smears positive for gram-negative bacilli. No CSF grew gram-negative bacilli, and chart reviews confirmed a diagnosis of factitious meningitis in each case. In addition to the clusters of false-positive smears, this had occurred sporadically in both years. The problem did not recur after separate sterile tubes were provided for CSF collection. Physicians and laboratories should be aware that nonviable contaminants in commercial products may be a source of false-positive CSF gram-stained smears.

Factitious Meningitis: A Recurring Problem

Although gram-negative meningitis is rare in our hospital, between July, 1982 and July, 1983 clusters of cerebrospinal fluid (CSF) smears were reported positive for gram-negative bacilli. Fourteen specimens were obtained by diagnostic lumbar punctures, and one was obtained during a myelogram. No CSF cultures were positive, and a diagnosis of factitious meningitis was eventually established for each patient. Nonviable gram-negative bacilli were found in 6.7% of manometers, and 23.3% to 90% of the specimen tubes tested from the same lots of commercial lumbar puncture trays. It was estimated that there were between 44 and 333 organisms per specimen tube. Two lots of the commercial myelogram trays yielded nonviable gram-negative bacilli from 50% of the specimen tubes and 33.3% of the manometers tested. Retrospective review of laboratory records for 1982 and 1983 revealed 23 total CSF smears positive for gram-negative bacilli. No CSF grew gram-negative bacilli, and chart reviews confirmed a diagnosis of factitious meningitis in each case. In addition to the clusters of false-positive smears, this had occurred sporadically in both years. The problem did not recur after separate sterile tubes were provided for CSF collection. Physicians and laboratories should be aware that nonviable contaminants in commercial products may be a source of false-positive CSF gram-stained smears.

Ultrastructural details as revealed by stereo transmission electron microscopy of high resolution, pre-shadowed surface snd freeze-etch replicas: sample— the drosophila eye

Whereas SEM is useful for studying the surface of objects such as an insect eye at relatively low magnifications, TEM of pre-shadowed replicas has advantages for visualization of the ultrastructural details of surfaces, and freeze-fractured, or freeze-etched specimens.For surface replica studies, fruit flies (Drosophila melanogaster) were glued with glycerol onto a solid copper cap which was then placed on the stage of the Denton freezeetch module. Specimens were frozen by flowing liquid nitrogen into the specimen tube. When specimen temperature reached -105°C, the chamber was evacuated and the shroud cooled to -196°C. With a vacuum of 5 x 10-6 mm Hg, the specimen was warmed to -95°C for 3 to 5 minutes to allow sublimation of any ice which might have condensed on its surface. Specimen temperature was then lowered to -150°C and specimen was shadowed with Pt and coated with carbon.

Temperature control apparatus used in flagellar regeneration experiments

Figure 38 illustrates diagrammatically the type of apparatus used to control temperature in the regeneration experiments of §V. The centrifuge box on the left of the diagram is used for the separation of cell bodies subsequent to deflagellation outside. The centrifuge is a variable speed type capable of a maximum 1600 rev/min. Thermal insulation is provided by a 3 in. thickness of expanded polystyrene. The temperature of this box is only roughly controlled to approximately 1 °C by means of a refrigerator probe and hot air blower. Both heating and cooling elements are under the control of mercury contact thermometers. The deflagellated organisms and the undeflagellated controls are placed in specimen tubes mounted on a rack in the right-hand chamber built from copper sheet and insulated in the same manner as chamber 1. Cooling or heating of this container is carried out by four thermo-electric units which are controlled by a thermistor temperature regulating system. The transparent top cover of the box allows the light from a 22 W fluorescent tube to illuminate the specimen area, and is also provided with small orifices through which specimen samples may be taken. The thermal conditions inside the growth compartment, recorded over 12 h continuous operation, showed temperature differentials, of the order of 0·05 °C, and within the specimen tube, better than 0·01 °C.

Freeze-Etching Simplified

Freeze-etching, as a tool in the preparation of biological specimens for electron microscopy, has seen relatively little use since it was introduced in 1957. The involved procedure, originally described, and, until recently, the cost of special equipment, must certainly have played a part in the failure of freeze-etching to become a commonly used technique. Efforts to solve some of the problems have resulted in the development of a modified freeze-etching module that can fit on nearly any vacuum evaporator and will permit the production of good specimens by an unskilled technician in less than one-half hour.The freeze-etching module (Fig. 1) consists of a collar (A) with two opposing hollow tubes supported by small collars so that the specimen end of the specimen tube (D) can rotate within the rotatable cold shroud (F).