Sharp Blades Research Articles

Quixotic

Quixotic Jenna Le (bio) Plymouth, NH We shrieked Eyesore!, blew raspberries, chagrinedwhen Groton's turbines loomed on the horizonin the most literal sense. No charming windmillsof the Old Dutch waffle-wingèd kind,these power generators, gray-shark-finned,are starkly functional as streptomycinand rawboned as a weasel that's been skinned.They crimp the mountain range whose shade we rise in each sunup, snarl its formerly streamlinedshape into one that there's no recognizing.Their sharp Inquisitorial blades remindus we're the sinning scions of folks who sinnedin their own times. We're told these shineless tinedmachines are meant to save us from a poisonwe fed ourselves, deluged our unrefinedintestines with. What starchy moralizing. [End Page 182] Jenna Le Jenna Le is the author of Six Rivers (NYQ Bools, 2011) and A History of the Cetacean American Diaspora (Indolent Books 2018). She was selected by Marylin Nelson as winner of Poetry By The Sea's inaugural sonnet competition in 2019. She has recent poems in AGNI, Poet Lore, and West Branch. She can be found at Jennalewriting.com. Copyright © 2020 Pleiades and Pleiades Press

Cutting resistance of soft materials: Effects of blade inclination and friction

In cutting soft elastic materials, friction is often the most relevant term of the total applied force, and techniques to minimise the required effort involve the restraint of frictional dissipation. It is well known from practical experience that cutting is made much easier if performed with a combination of slicing and pushing. A slice-push effect, known to reduce the cutting force, can be introduced by skewing the blade with respect to the travelling direction of the blade itself. The observed drop of the required force is connected to the competing dissipative contributions, with frictional dissipation being reduced at larger inclination angles. This study reports the results of several cutting tests on soft elastomeric plates, in which we have recorded the experimental force-displacement curves during the insertion of sharp stainless-steel blades. An energy-based model is employed to discern the different contributions to the measured force in the various stages of the cutting process, with particular focus on the steady state initiated after full penetration of the blade. The effects of the inclination angle of the blade are discussed with respect to the steady state force obtained from the experiments.

Edged weapons awareness.

Edged weapons (sometimes referred to as sharp weapons or blades) are an increasing threat to military personnel, the blue light community (police, ambulance, firefighters, other first responders) and the general public worldwide. The use of edged weapons in criminal and terrorist incidents internationally means the forensic community needs an awareness of the technology of edged weapons, how they are used, the damage (clothing and wounding) that might be caused and any other forensic implications. In this paper, the magnitude of the problem is presented, prior research summarised and implications for forensic investigations discussed.

Identification of Obsidian Sources on Milos, Greece

Obsidian, a natural volcanic glass, was used extensively in ancient times because of its quality as a raw material for sharp blades. As such, obsidian is of high interest for provenancing studies, since reliable provenancing can provide information about trade routes, extension of territory, long-distance contacts and the mobility of prehistoric peoples. In general, well-established databases of the characteristic elemental composition, the chemical fingerprint, are needed for reliable provenancing. On Milos Island, two sources of raw obsidian, namely Agia Nychia (Cape Bombarda) and Demenegakion are known. Recent literature claims a third source close to Agios Ioannis. In a sampling expedition with the goal to complete the Atominstitut’s database on the chemical fingerprints of obsidian, samples at Agios Ioannis were collected to include this new source. At the location, 16 scattered samples were taken for analysis, even though no direct outcrop could be identified. On the nearby island Kimolos, several more samples were found. Using instrumental neutron activation analysis (INAA), the chemical fingerprint of the samples was measured and compared to the values in the database. All samples from Agios Ioannis were identified as either from Demenegakion or Agia Nychia, indicating that no further source of obsidian exists at the location.

Foreign Body Extraction Extravaganza! Approach to 25 Foreign Bodies, One Patient

Introduction: Specific characteristics of foreign bodies can present as challenges to successful endoscopic removal. Endoscopic removal is urgent in cases of sharp objects, esophageal obstruction, or battery ingestion. Case: A 45-year old Caucasian inmate with a history of bipolar disorder, self-injurious behavior (including self-mutilation creating enterocutaneous fistula), and ingestion of six AA batteries previously presented for repeat ingestion of multiple foreign bodies with diffuse abdominal pain, hemoptysis, and nausea. His vitals were stable with no significant lab abnormalities. Abdominal x-ray revealed 3 radio-opaque foreign bodies: An irregular circular object, a straightened paperclip, and a hexagonal/rectangular density. Cross-sectional imaging noted stable appearance straightened paperclip was interposed between stomach and transverse colon mesentery without perforation or inflammation. Neck and chest x-rays were negative for perforated viscus. Upper endoscopy was initially performed with moderate sedation, revealing multiple sharp razor blades in the stomach. The procedure was aborted to be performed with general anesthesia. Subsequent endoscopy resumed under general anesthesia. A blunt disc-shaped metallic object was removed with rat-toothed forceps and one AA battery was removed with a snare. A hood placed at the end of the endoscope for removal of sharp razorblades, however only partially opened at GE junction. A long esophageal overtube was placed. Subsequently, 21 razor blades were individually removed as an endoscopy technician held overtube in place to prevent migration and exposing GE junction/distal esophagus to sharp objects. Finally, two irregular circular objects, one of which became lodged into the overtube, were removed with both the snared lodged object and overtube taken out together from the mouth at the conclusion of the procedure. The patient tolerated the procedure well and was extubated without complication. Follow up abdominal x-ray did not reveal any remaining foreign bodies. The patient remained stable and discharged. Conclusions: Endotracheal intubation and general anesthesia should be considered for prolonged cases and safe endoscopic removal of multiple and/or sharp foreign bodies. A long esophageal overtube is preferred over hood for removal of sharp objects from the stomach. Future design improvements in endoscopic tools could aid in safer and more effective means of foreign body removal.1889_A Figure 1 No Caption available.1889_B Figure 2 No Caption available.1889_C Figure 3 No Caption available.

Miniaturized Optical Resolution Photoacoustic Microscope Based on a Microelectromechanical Systems Scanning Mirror.

In this paper, we report a miniaturized optical resolution photoacoustic microscopy system based on a microelectromechanical system (MEMS) scanning mirror. A two-dimensional MEMS scanning mirror was used to achieve raster scanning of the excitation optical focus. The wideband photoacoustic signals were detected by a flat ultrasound transducer with a center frequency of 10 MHz and an active area of 2 mm in diameter. The size and weight of this device were 60 mm × 30 mm × 20 mm and 40 g, respectively. We evaluated this system using sharp blades, carbon fibers, and a silver strip target. In vivo experiments of imaging vasculatures in the mouse ear, brain, and human lip were completed to demonstrate its potential for biological and clinical applications.

Rüzgâr Türbinlerinin Yıldırımdan Korunması için Bir Eğitim Setinin Tasarlanması

Among renewable energy sources, wind energy has drawn a great attention in last decade. Wind turbines are usually installed at places with high altitudes because of the nature of the wind. In addition to this, wind turbines have sharp blades. Due to these two features of wind turbines, they can be exposed to lightning. Hence, lightning protection of wind turbines is a critical subject. In this study, an educational kit is designed to demonstrate the lightning protection methods of wind turbine. By using this kit, different receptor, conductor or types of placement of conductor can be examined. In this study, design steps of the kit is presented in details. The educational kit is also tested under artificial lightning which are generated in the high voltage laboratory and measurement results are presented. The education kit is also used by students in a laboratory course to understand lightning protection of a wind turbine.

INVESTIGATION OF SKIN LACERATION THRESHOLD UNDER A SPECIFIC CONDITION: BLADE PENETRATION TEST ON PORCINE SKIN

Skin lacerations are not fatal but constitute one of the most common injuries in daily life. There is a need, therefore, for measures to prevent skin lacerations caused by accidents; however, since only a few engineering studies have been undertaken, the threshold of skin laceration is still unclear. In this study, the thresholds of skin laceration under moderate loading rate are proposed according to the results of penetration tests on porcine skin using a knife or blunt blade. In the tests, a sharp blade (knife) and blunt blade with an edge having a small radius of curvature were applied to the external surfaces of dorsal and ventral porcine skin specimens. Penetration tests using sharp blades showed that the average rupture load was 39.0[Formula: see text]N for dorsal skin and 36.0[Formula: see text]N for ventral skin. On the other hand, the results of the penetration tests using the blunt blade were statistically analyzed by ordinal logistic regression, because the rupture load could not be defined precisely based on the load sequence data. The regression curves show that the rupture loads for a 50% probability were within the range of 123.7[Formula: see text]N to 214.4[Formula: see text]N for dorsal region skin and 80.1[Formula: see text]N to 160.0[Formula: see text]N for ventral region skin.

Photoacoustic endomicroscopy based on a MEMS scanning mirror.

In this Letter, we present a high-resolution photoacoustic endomicroscopy probe based on a microelectromechanical systems (MEMS) scanning mirror. The built-in optical assembly consists of a 0.7mm graded-index (GRIN) lens for light focusing and a ϕ1 mm MEMS mirror to reflect and scan the beam. A miniaturized unfocused ultrasound transducer with a center frequency of 10MHz is used for photoacoustic detection. Sharp blades, carbon fibers, and black tapes were utilized to evaluate the performance of the system. In vivo mouse ears and resected rectums were imaged to further demonstrate the feasibility of this probe for potential biological and clinical applications.

An energy dissipating mechanism for crushing square aluminium/CFRP tubes

A platen with cutting blades was introduced as a new energy dissipating mechanism to simultaneously cut and crush square bare CFRP tubes and CFRP tubes wrapped externally with aluminium sheets. The specially designed and manufactured platens with four round tip blades, four sharp tip blades and eight round tip blades were used to reduce the initial peak crushing force and increase the energy absorption of CFRP tubes. Notches were introduced at one end of tubes to control the location of the initial failure. Experimental results showed that the deformation mode of CFRP tubes and aluminium sheet-wrapped CFRP tubes that were crushed by platens with blades was a combination of splaying progressive and transverse shearing failure mode. More damage was observed to CFRP plies when tubes were crushed by using round tip blades. Tubes cut and crushed by a platen with eight round tip blades had a lower initial peak crushing force, higher mean crushing force, larger energy absorption and higher specific energy absorption in comparison with counterpart tubes crushed by flat platens. A comparison between the new trigger mechanism proposed in this study (cutting blades) and other different trigger mechanisms used in published literature was made.

Inverted multiscale optical resolution photoacoustic microscopy.

Optical resolution photoacoustic microscopy (ORPAM) is one of the fastest evolving photoacoustic imaging modalities. It not only has a comparable spatial resolution to pure optical microscopies such as epifluorescence microscopy, confocal microscopy, and two-photon microscopy, but also owns a higher penetration depth. In this study, we report an inverted multiscale (IM)-ORPAM that utilizes a two-dimensional galvanometric scanner integrated with two microscopic imaging lenses to achieve rotary-scanning-based multiscale imaging. A 15MHz cylindrically focused ultrasonic transducer is mounted on a motorized rotator to synchronously follow the optical scanning paths. To minimize the loss of signal-to-noise ratio, the acoustic focal line is precisely adjusted confocal with the optical focal plane. Black tapes, carbon fibers, and sharp blades are imaged to evaluate the performance of the system, and in vivo multiscale imaging of vasculatures inside the ears and brains of mice is demonstrated using this system.

Development of a Tractor Operated Sugarcane Cutter Planter for Mechanisation of Sugarcane Planting in Deep Furrows

A tractor operated sugarcane cutter planter was designed and developed at ICAR-Indian Institute of Sugarcane Research, Lucknow (IISR) for planting of sugarcane. It was equipped with deep furrow opener to facilitate furrow method of sugarcane planting. The designed planter consisted of deep furrow opener, sharp edged blades to cut whole cane into 350 mm long pieces as seed material, metering device for application of fertiliser and insecticide, soil covering shovels and tamping roller for pressing soil cover. It was a mounted type equipment rigidly attached with tractor through three-point linkage. Planter was pulled by the tractor and its cutting blades and fertiliser metering rollers were driven by tractor PTO shaft. Planter was field tested at IISR farm in sandy loam soil. At forward speed of 0.5 ms−1, mean overlapping between two successive setts were 72 mm, which was acceptable and well within the desired overlapping range of 50–100 mm for subtropical India. Effective field capacity (output) of the planter was 0.16 ha h−1. Its performance was compared with conventional method of planting. Depth of furrow was 250 mm in case of the planter as against 120 mm in conventional method. Mean soil covering depth over planted setts was 80 mm. Mean bud emergence improved by 3.7 % in case of the planter as compared to conventional planting. Only 25 labour-h ha−1 labour is involved for planting with the developed planter which is about 11 times less than the conventional method of planting (280 labour-h ha−1). Cost of planting operation was also saved by about 63 % using the developed planter.

How to Avoid Cast Saw Complications

As casts are routinely used in pediatric orthopaedics, casts saws are commonly used to remove such casts. Despite being a viewed as the "conservative" and therefore often assumed safest treatment modality, complications associated with the use of casts and cast saws occur. In this manuscript, we review the risk factors associated with cast saw injuries. Cast saw injuries are thermal or abrasive (or both) in nature. Thermal risk factors include: cast saw specifications (including a lack of attached vacuum), use of a dull blade, cutting in a concavity, too thin padding, and overly thick casting materials. Risk factors associated with abrasive injuries include: sharp blades, thin padding, and cutting over boney prominences. Because nearly all clinicians contact the skin with the blade during cast removal, appropriate "in-out technique" is critical. Such technique prevents a hot blade from remaining in contact with the skin for any significant time, diminishing the risk of burn. Similarly, using such technique prevents "dragging the blade" that may pull the skin taught, cutting it. It may be useful to teach proper technique as perforating a cast rather than cutting a cast.

Modified methods for isolation of pancreatic stellate cells from human and rodent pancreas.

Primary cultures of pancreatic stellate cells (PSCs) remain an important basis for in vitro study. However, effective methods for isolating abundant PSCs are currently lacking. We report on a novel approach to isolating PSCs from normal rat pancreases and human pancreatic ductal adenocarcinoma (PDAC) tissue. After anaesthesia and laparotomy of the rat, a blunt cannula was inserted into the pancreatic duct through the anti-mesentery side of the duodenum, and the pancreas was slowly infused with an enzyme solution until all lobules were fully dispersed. The pancreas was then pre-incubated, finely minced and incubated to procure a cell suspension. PSCs were obtained after the cell suspension was filtered, washed and subject to gradient centrifugation with Nycodenz solution. Fresh human PDAC tissue was finely minced into 1×1×1 mm3 cubes with sharp blades. Tissue blocks were placed at the bottom of a culture plate with fresh plasma (EDTA-anti-coagulated plasma from the same patient, mixed with CaCl2) sprinkled around the sample. After culture for 5–10 days under appropriate conditions, activated PSCs were harvested. An intraductal perfusion of an enzyme solution simplified the procedure of isolation of rat PSCs, as compared with the multiple injections technique, and a modified outgrowth method significantly shortened the outgrowth time of the activated cells. Our modification in PSC isolation methods significantly increased the isolation efficiency and shortened the culture period, thus facilitating future PSC-related research.

Repeatable pre-cracking preparation for fracture testing of polymeric materials

Currently, in order to create a sharp pre-crack in a polymeric material for fracture toughness testing, a hand-held razor blade is used. This technique produces cracks of varying angle, length, and crack-front shape. Additionally, there are considerable safety concerns regarding the handling of sharp razor blades. A repeatable, safe method of producing a consistent, sharp pre-crack of a specified length, orientation and crack front is presented here, by use of a simple custom fixture. The specimen preparation procedure has wide applicability for fracture analysis of many brittle materials.

Tracheal intubation in patients with anticipated difficult airway using Boedeker intubation forceps and McGrath videolaryngoscope.

Videolaryngoscopes with sharp angulated blades improve the view of the vocal cords but this does not necessarily result in higher success rates of intubation The aim of this study was to evaluate the efficacy of using Boedeker intubation forceps in conjunction with McGrath Series 5 Videolaryngoscope (MVL) in patients with predictors for difficult intubation. The study was conducted at the Department of Anaesthesia, Copenhagen University Hospital from September to December 2013. Patients with one or more predictors of difficult intubation scheduled for general anaesthesia were assessed for eligibility. Patients were intubated using Boedeker intubation forceps and MVL. The primary endpoint was time to intubation. The secondary endpoints were intubation success rate, number of intubation attempts, intubation conditions and post-operative hoarseness. Thirty-three patients were assessed for eligibility, and 25 patients were included in the study with a median SARI score of 3 (IQR 3-4). Twenty-two (88%, 95% confidence interval [74-100%]) of the patients were successfully intubated by the method with a median time to intubation of 115 s (IQR 78-247). Steering and advancement of the tube were reported as acceptable in 21 (84%) and 22 cases (88%), respectively, and excellent in 10 cases (45%) for both measures. Ten cases (40%) were intubated on the first attempt. There were three cases (12%) of failed intubation; in these cases, successful intubation was obtained by using a styletted tube. Most patients with anticipated difficult intubation can be successfully intubated with Boedeker intubation forceps and MVL. However, endotracheal tube placement failed in 3/25 patients despite a good laryngeal view.

Strong and Conductive Dry Carbon Nanotube Films by Microcombing.

In order to maximize the carbon nanotube (CNT) buckypaper properties, it is critical to improve their alignment and reduce their waviness. In this paper, a novel approach, microcombing, is reported to fabricate aligned CNT films with a uniform structure. High level of nanotube alignment and straightness was achieved using sharp surgical blades with microsized features at the blade edges to comb single layer of CNT sheet. These microcombs also reduced structural defects within the film and enhanced the nanotube packing density. Following the microcombing approach, the as-produced CNT films demonstrated a tensile strength of up to 3.2 GPa, Young's modulus of up to 172 GPa, and electrical conductivity of up to 1.8 × 10(5) S m(-1) , which are much superior to previously reported CNT films or buckypapers. More importantly, this novel technique requires less rigorous process control and can construct CNT films with reproducible properties.

Electrohydrodynamic Plumes due to Autonomous and Nonautonomous Charge Injection by a Sharp Blade Electrode in a Dielectric Liquid

This paper addresses the numerical investigation of an electrohydrodynamic (EHD) plume induced by a sharp blade electrode in a dielectric liquid. Different injection laws, namely, autonomous and nonautonomous ones, are considered, and the importance of the blade shape is emphasized, especially for nonautonomous injection laws. Different flow regimes arise according to the value of the Reynolds number based on the ionic mobility and the distance d between the blade and the vertical plate. It is found that the critical Reynolds number for which the transition between steady and unsteady regimes occurs depends on the injection law, on the blade shape, on the M parameter, and on the injection strength C. For much higher Reynolds number, the flow turns to be chaotic and behaves as a jet flow with the development of a Kelvin-Helmoltz instability. The use of different sharp blades indicates that a higher electric field at the tip of the blade plays a significant effect on the development of the EHD plume. The plumes have been characterized by their charge density distribution which shows, in the early stages of the simulation, that its dynamics is significantly dependent on the blade shape as well as on the nonautonomous injection law.

Socio-economic Importance of Bamboo among the Nagas of Nagaland

Bamboo is grown extensively in Nagaland and the socio- economic life of the Nagas revolves around the varied use of bamboo and its products. Beginning with the sharp bamboo blades prepared to remov...

Overuse Injuries Of Finnish Elite Junior Ice Hockey Players. Prospective Online Survey

Frequent forceful impacts, the unpredictable nature of the game, the long sticks and the sharp blades of the skates as well as high velocity of skating and shooting the puck make ice hockey an injury-prone sport. Most of the previous ice hockey injury studies have focused on traumatic injuries. In team sports, absence of one player may affect the team´s performance and chances of winning. This fact might create pressure for a player to decide to compete while injured or ill. The purpose of the study was to define the number, type, and anatomic location of overuse injuries in the high level Junior A and B (15–19-year-old) ice hockey players, and whether players report the injuries to coaching and medical staff. Players self-reported the injury data via online survey. The data was collected between September 2009 and March 2010. Out of 55 subjects, 33 players (62%) were injured. Of all injuries, 70.4% (45 injuries) were traumatic and 69.6% (19 injuries) were overuse injuries. Players reported 95% of the injuries to coaching staff and they reported 75% of the injuries to medical staff. Injuries that were not reported to coaching or medical staff were minor injuries. The estimated average probability of player sustaining at least one injury during the season was 62.2% (95% CI 0.49–0.75). Hip/groin was the most common site for overuse injury (7 injuries, 36.8% of all overuse injuries). Therefore, injury prevention focus should be placed on reducing the number of muscle sprains and especially hip/groin injuries. More knowledge is needed about the modifiable risk factors of these injuries. Injuries that were not reported to coaching or medical staff were all minor injuries.