Knife Blade Research Articles

Effect of Alloying Elements on the Sharpness Retention of Knife Blades Made of High Carbon Martensitic Stainless Steels

Blades usually become blunt as the blade tip suffers wear during cutting, and improving the sharpness retention of steel blades has become an attractive prospect in various industries. In this study, blades were fabricated from commercial high carbon martensitic stainless steels (154CM, 440C and N690) with different contents of alloying elements. 154CM with higher Mo content demonstrated superior capability in sharpness retention to 440C and N690, although these steels exhibit similar chemical composition, carbide phases, microstructure and HRC hardness. Further investigations via SEM and nanoindentation indicated that the faster deterioration of sharpness in 440C and N690 may result from the fatigue peeling of the carbides, which was aggravated by the modulus mismatch between carbide particles and the martensitic steel matrix.

The Titer of Citrus Yellow Vein Clearing Virus Is Positively Associated with the Severity of Symptoms in Infected Citrus Seedlings.

Citrus yellow vein clearing virus (CYVCV), a new member of the genus Mandarivirus in the family Alphaflexiviridae, is the causal agent of citrus yellow vein clearing disease. CYVCV is transmitted to citrus by Dialeurodes citri, grafting, and contaminated knife blades, threatening citrus production. In this study, four infectious full-length complementary DNA clones of CYVCV (namely AY112, AY132, AY212, and AY221) derived from CYVCV isolate AY were obtained through yeast homologous recombination and inoculated to 'Eureka' lemon (Citrus limon Burm. f.) by Agrobacterium-mediated vacuum infiltration. Pathogenicity analysis indicated that the clones AY212 and AY221 caused more severe symptoms than AY112 and AY132. Northern blot and quantitative reverse transcription PCR analyses showed that the titers of virulent clones (AY212 and AY221) were significantly higher than those of attenuated clones (AY112 and AY132) in the infected 'Eureka' lemon seedlings. Subsequent comparative studies of viral infectivity, accumulation, and symptoms induced by AY221 in nine citrus cultivars indicated that the infectivity of AY221 varied from 25 to 100% between cultivars; 'Oota' ponkan (C. reticulata L.) showed the lowest infection rate, with mild symptoms, which might be a useful resource for CYVCY-resistance genes; and CYVCV titer was positively associated with the symptom development in infected citrus seedlings. In general, this report revealed the biological properties of CYVCV, thus laying a foundation for further investigation of pathogenic mechanisms in this virus.

Penetrating chest trauma in Sauer's danger zone without serious heart or lung damage: An unusual case report.

Introduction and importanceSauer's danger zone is an area on the anterior chest where trauma is considered to cause heart and macrovascular injury. Herein, we report the case of an injured patient showing evidently fatal findings on chest radiography and computed tomography (CT) presenting almost no actual fatal injuries on surgical examination.Case presentationThe patient was an 86-year-old man who was found by a family member with a 30-cm knife blade stuck in his left front chest (Sauer's danger zone). On chest CT findings, the knife was observed to be inserted through the 4th intercostal space, penetrating the lungs. The tip of the knife appeared to be anchored to the dorsal side of the 9th intercostal space.Clinical discussionWe found no damage to the heart, only a 2-cm-long and 1-cm-deep cut in the lingular segment area.ConclusionWe confirmed that the amount of bleeding in the inserted drain was an indicator of non-macrovascular injury. In cases of chest trauma, chest tube drainage and hemodynamics should always be observed, and the potential need for emergency surgery should be considered.

Characterization of the transfer probability of Salmonella ser. Typhimurium between pork and a cutting knife in an experimental model

Cross-contamination is an important event for bacterial transfer throughout the pork production chain. In Brazil, Salmonella sp. is the most relevant hazard in the pork industry, and further knowledge concerning its contamination is essential for in-depth risk assessments. Thus, we aimed to assess the transfer probability of Salmonella sp. between a knife and pork in a domestic kitchen scenario to provide parametrization for incorporating transfer of Salmonella sp. in risk assessment models. To estimate Salmonella Typhimuium transfer rates between contaminated pork and a knife blade during cutting, 23 independent experiments were performed. A Bayesian inference was utilized to determine the transfer probability, capturing the uncertainty generated in the transfer probability experiments. The mean transfer probability was 0.03 for knife to pork [0.029; 0.032] 95% credible interval (CrI) and 0.0042 for pork to knife [0.0041; 0.0043] 95% CrI. The probabilistic estimate of the transfer probability of Salmonella sp. during pork cutting gives insights on a relevant parameter for the consumer phase of the pork production industry in Brazil, allowing for enhanced risk assessment models.

Late-onset Seizure and Left Hemiparesis after Unusual Craniocerebral Penetrating Injury by a Rusty Sickle: A Case Report

BACKGROUND: Penetrating head injuries are a significant public health problem in worldwide, with an estimated 35.000 civilian deaths annually. Patients that survive to reach the hospital require rapid triage and imaging evaluation. This case report describes a patient with late-onset seizures and left hemiparesis after unusual craniocerebral penetrating injury by a rusty sickle. CASE PRESENTATION: A 26-year-old man reported that he had a sickle stabbed into the right-side parietal area. On admission, he had no neurological deficits. The rusty sickle was broken off just above the skull and did not protrude from the scalp. Computed tomography showed that the knife blade was in the parenchyma without underlying tract hematoma. Surgery was performed after 2 h of admission. Post-operatively, he recovered with no neurological deficit. After 16th days postoperatively, he was complaining of seizure and left hemiparesis. CT scan with contras showed edema and hypodense lesion at the right side of hemisphere. A course of intravenous phenytoin 100 mg/8 h and ceftriaxone 2 g/day was initiated. Physical therapy was done on the patient for 2 weeks. CONCLUSION: Traumatic brain injury (TBI) is the result of energy being transferred from an object to the human skull and underlying brain. Post-traumatic epilepsy is a common complication and can occur as early or late manifestations related to penetrating TBI. Prophylactic treatment of post-traumatic seizures (PTS) is currently not routinely recommended beyond 1 week following head injury (role of antiseizure prophylaxis). Phenytoin is the most rigorously tested AED for PTS.

Normothermic regional perfusion surgical technique for the procurement of cardiac donors after circulatory death.

Normothermic regional perfusion surgical technique for the procurement of cardiac donors after circulatory death.

Розрахунок параметрів тунельного розрізу при факоемульсифікації у хворих з раніше проведеною передньою радіальною кератотомією

Мета. Вибір типу тунельного розрізу на підставі математичних розрахунків у хворих на катаракту з раніше проведеною передньою радіальною кератотомією. Матеріали та методи. У розрахунках використовувалась формула довжини хорди окружності: L = 2R · sin(α/2), де R — радіус рогівки, α — кут у градусах між двома рогівковими надрізами. Довжину хорди вимірювали на лімбі (верхній край тунельного розрізу) та 2 мм від лімба (ніжній край тунельного розрізу). Більш важливою є хорда 2 мм від лімба, тому що відстань між кератотомічними розрізами в цьому місці є меншою. До ширини леза ножа необхідно додати ще від 0,4 мм до 1,0 мм залежно від типу післяопераційного загоювання рогівки, що і буде запорукою пересічення розрізів. Результати. Найпоширенішими є ножі 2,2 мм та довжиною тунелю 2 мм. Тому проводимо розрахунки на базі цього ножа у пацієнтів з 8 та 12 кератотомічними розрізами та діаметром рогівки 12 мм за вертикаллю та 11 мм за горизонталлю. У пацієнтів з 8 кератотомічними розрізами є можливість використовувати ніж 2,2 мм для рогівкового тунельного розрізу, а у хворих з 16 насічками використання рогівкового тунелю неможливе. Висновки. У пацієнтів, хворих на катаракту, в яких раніше була проведена передня радіальна кератотомія, потрібен особливий підхід щодо вибору тунельного розрізу. Вибір доступу залежить від діаметра рогівки, кількості кератотомічних надрізів та ширини ножа і вираховується за допомогою формули довжини хорди окружності.

Variability and specificity of bone cutting mark properties in cases involving stabbing with knives.

Sharp force traumas are frequently encountered in stabbing crime victims. During an examination, the properties of cutting marks in bones are compared with the properties of suspect tools, particularly knives. Therefore, the variation and specificity of knife and cutting mark properties must be known. This article provides the variability and specificity of a set of knife blade and cutting mark properties. Plain and serrated knives are used to create experimental cutting marks in porcine ribs, knife properties are derived from surface acquisitions of the blades and mark properties from Micro-CT data. We consider two conditions, automated stabbing using a motorized stage and manual stabbing. In addition, we study the influence of maceration on marks. For knives, the blade edge angle, blade thickness, and bevel height, and for cutting marks, the shape, the wall angle, the width, and the bevel height are determined and compared. The results show that the relationship between corresponding properties of blades and marks depends on the knife type. For plain knives, the width and wall angle of the marks are dependent on the mark depth and are significantly smaller than the blade properties edge angle and width. For serrated knives, this is not the case. The mark shape only provides slight support for a knife type for marks deeper than the blade bevel height. In conclusion, mark properties are only specific for a particular knife brand and model if the blade properties differ significantly and assuming a specific knife type.

An Unusual Cervical Penetrating Wound Extended to the Right Pleural Dome

The solution of continuity of the tissues of the neck with rupture of the platysma muscle is called a cervical penetrating wound. The authors report a case of an unusual penetrating neck wound extended to the pleural dome by stabbing a psychiatric patient. They describe the diagnostic circumstances, the therapeutic approach and discuss data from the literature. It was a 26-year-old young woman, who was received in ENT for a penetrating neck wound with a stab wound following a suicide attempt. The diagnosis of a penetrating stab wound to the neck extending to the right pleural dome was retained. The exploratory cervicotomy with the extraction of the foreign body found a knife blade penetrating the anterior base of the right side of the neck to the right pleural dome, sparing the noble vasculo-nervous and aero-digestive organs of the neck. The postoperative course was simple and the evolution was favourable. This unusual penetrating wound of the neck is spectacular and remarkable for the absence of involvement of noble organs despite the involvement of the pleural dome. However, it remains a concern in psychiatric patients and requires multidisciplinary management and systemic management in order to avoid recurrence.

МОДЕЛИРОВАНИЕ НАПРЯЖЕННОГО СОСТОЯНИЯ ДЛЯ РАСЧЕТА ПРОГИБА СТЕРЖНЕВОГО КОНСОЛЬНОГО НОЖА ПРИ АВТОМАТИЗИРОВАННОМ РАСКРОЕ ТКАНИ

The article de nes the relevance of calculating the strength and stability of the movable cutting tool of cutting machines in the textile industry. A mathematical model for calculating the parameters of the stress state, the de ection of the cantilever cutting knife blade when cutting the fabric at any time is described. The relationship between the stability of knives used in mobile cutting machines and automated units and the cutting error has been determined. Parameters of wear of the cutting edge of the knife have been determined. Recommendations are given on the application of the research results in industrial production and in the modernization of automated cutting equipment to improve the accuracy of fabric cutting.

Materiały krzemieniarskie ze stanowiska Wysoka 1, pow. łańcucki (badania 1995)

This study contains information about flint materials discovered at the site 1 in Wysoka, Łańcut commune. This inventory consists of 57 items. Most of them were discovered in the context of features of the Mierzanowice culture. They are made mainly of Świeciechów flint, and they are of typical Early Bronze Age flintwork nature (half-products of bifacial axes, backed blade knife). In addition, not numerous Neolithic artefacts of the Malice culture were discovered there.

Interrupted Incision Fasciotomy for Acute Compartment Syndrome After Extracorporeal Membrane Oxygenation: Surgical Technique with a Report of Two Cases

BackgroundAfter extracorporeal membrane oxygenation (ECMO), acute compartment syndrome (ACS) can develop because of limb ischemia or reperfusion. The standard treatment for ACS is emergency fasciotomy. We introduced an interrupted incision technique instead of a long double‐incision to reduce blood loss and subsequent hypovolemia in ECMO patients.Case presentationTwo patients were treated venoarterial ECMO with heparinization by inserting cannulas into their right femoral vessels: Case #1 after emergency pulmonary thrombectomy for massive pulmonary thrombi and Case #2 after percutaneous coronary intervention for ST‐elevation myocardial infarction with ventricular fibrillation. Some of the ‘5 P' signs of ACS were detected on their right legs. We treated them with the interrupted incision fasciotomy: four or five skin incisions of 2–3 cm each on lateral side; one 6–7 cm proximal skin incision with one or two separate short distal skin incisions of 1–1.5 cm each on the posteromedial side. The subcutaneous layer was also incised through these interrupted incisions; interrupted multiple “soft tissue tunnels” can be formed above muscle layer between the incisions. Once the fascia was exposed, the connected fasciotomy was performed with the knife blade facing subcutaneous layer, rather than muscle. The two patients' foot pulse, skin color, and muscle tone were immediately restored, and delayed primary wound closures were possible. Both patients were satisfied with their limb salvage and could walk with a little help using an orthosis or a cane.ConclusionsWe recommend the interrupted incision fasciotomy as an attractive and effective technique for ACS, particularly after ECMO.

Study on working bodies of the soil preparation machine for sowing potatoes

The purpose of the study is to substantiate the parameters of the guide knife and the loosening pointed leg of the machine. The basic principles and methods of classical mechanics, mathematical analysis and statistics were used in this study. Theoretical studies were carried out to determine the parameters of the guide knife and the loosening pointed leg of the machine. It is established that to ensure the required value of the crest height with minimal energy consumption, the height and length of the guide knife should be 8 and 15 cm, respectively, the angle of the knife blade to the horizon - 30º, the longitudinal distance from the toe of the ploughshare body of the knife toe – 13 cm. To ensure the required crumbling of the soil, the width of the pointed loosening paw should be 15 cm.

An effective approach to fabricate the corrosion resistance of superhydrophobic ZnO/Ni composite coating on carbon steel substrate

In this study, the carbon steel substrates were coated with nickel (Ni), zinc oxide (ZnO) and ZnO/Ni coatings by electrodeposition approach and modified with stearic acid (STA)-ethanol solution to obtain STA-Ni, STA-ZnO and STA-ZnO/Ni coatings, respectively. The surface morphologies, chemical compositions and surface roughnesses of the modified coatings were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and confocal laser scanning microscope (CLSM), respectively. The wettability tests shows that the water contact angle (WCA) of the modified coatings with micro/nanostructure are all greater than 150° and the sliding angle (SA) are all less than 10°, especially the STA-ZnO/Ni coating with a WCA of 164.3° and a SA of 2.3°, displaying the prominent superhydrophobicity. Interestingly, the three modified coatings all exhibited excellent mechanical stabilities and self-cleaning properties after being scratched by a knife blade, peeled off by adhesive tape, abrased by sandpaper, and contaminated by chalk dust. Moreover, the corrosion resistance tests confirms that the STA-ZnO/Ni superhydrophobic coating possess higher durability and anticorrosion performance than that of STA-ZnO and STA-Ni coatings. The superhydrophobic STA-ZnO/Ni composite coating prepared by two-step electrodeposition combined with low surface energy material modification designed in this work shows great potential and prospect in industrial application.

Comparison of 70% Alcohol Disinfection and Sodium Hypochlorite Acid Disinfection on Kitchen Knife Blades, Handles and Cutting Boards

Comparison of 70% Alcohol Disinfection and Sodium Hypochlorite Acid Disinfection on Kitchen Knife Blades, Handles and Cutting Boards

Knife cut marks inflicted by different blade types and the changes induced by heat: a dimensional and morphological study

Detailed information on skeletal trauma analysis of burned bone is important to ascertain the manner and cause of death in forensic casework. This research used three different knife types, one with a non-serrated blade, one a fine-serrated blade, and one a coarse-serrated blade, to inflict trauma to manually macerated Sus scrofa ribs (n = 240), and these ribs were later exposed to heat. Qualitative and quantitative analyses were conducted using macroscopic and microscopic techniques to assess specific characteristics of the cut marks. Differences in cut mark dimension and morphology of the ribs were investigated. After heat exposure, the cut marks on the rib samples remained recognisable and did not alter considerably. A level of dimensional and morphological preservation was reliant on the cutting action and the features of the knife blade as well as surrounding bone injury. The cut marks inflicted by the non-serrated blade remained recognisable despite exposure to the burning process. However, the cut marks inflicted by the coarse-serrated blade were likely to change significantly when exposed to heat. This study leads to two important results: (1) identification of pre-existing cut marks prior to heat exposure is possible in reconstructed burned bone fragments, and (2) cut marks from different types of knife blades showed dissimilar responses to heat. The outcomes obtained in this study stressed the need to adopt great care with the effects of heat on skeletal trauma analysis.

ON THE ISSUE OF DETERMINING THE CRITICAL CUTTING SPEED OF THE MECHANISM FOR FORMING AND TRIMMING THE FALSE EDGE OF THE DORNIER RAPIER LOOM

In this paper, an attempt is made to develop a method for determining the critical cutting speed of the threads of the false edge of the edge-forming mechanism of the weaving rapier machine. The proposed calculation method takes into account the impact nature of the cutting process at a critical speed, which allows taking into account the mutual influence of the parameters of the working process and more fully assess the mechanics of this process, in which the intensity of the cutting force and the value of the contact stress take the maximum value. The paper calculates the critical cutting speed for some of the main types of threads used and the parameters of the knife blade. The presented calculation results can be used to select rational design parameters of the knife blade, depending on the type of processed threads, when designing and researching new edge-forming mechanisms on looms.

To the Creation of a Semiautomatic Device for Sharpening Cutting Pairs of Shearing Machines for Sheep

It has been established that the quality of sharpening, which ensures the sharpness of the comb and knife blades and their tight fit throughout the entire stroke of the latter, is of decisive importance for ensuring the cutting process to be performed by the cutting pair. It is shown that the used sharpening devices provide the necessary sharpness, but require high qualifications of sharpeners, whose training under the conditions of seasonal work is quite problematic. Based on the TA-1 apparatus and using a number of proven solutions, a semiautomatic device for sharpening cutting pairs has been developed, which makes it possible to exclude the influence of the human factor: the sharpener does not affect the sharpening process, it works as an operator and controller.

Application of ALD Thin Films on the Surface of the Surgical Scalpel Blade

The article describes biomaterials and surgical instruments, in particular surgical cutting tools. In addition, the functions of coatings and the layer vapor deposition methods are described. In the experimental component of the study, zinc oxide thin film was deposited on the surgical knife blades by the atomic layer deposition (ALD) method with a varying number of cycles. The structures of the deposited thin films were investigated using a Raman spectrometer and the surface topography of the samples was examined using atomic force microscopy and scanning electron microscopy. The adhesion of the thin films was tested using the micro-scratch method. The corrosion resistance was also tested. Surgical instruments coated with non-allergenic metal oxide coatings, containing metal structures that reduce the growth of bacteria, could significantly decrease the risk of undesirable reactions of the body during and after surgery.

Retained Lumbar Intradiscal Surgical Knife Blade Retrieved Via Extended Extraforaminal Approach: Case Report and Review

Background and Importance: During a lumbar discectomy, the surgical knife might be broken and embedded deeply within the disc space. In some cases, it may be impossible to remove the broken blade during the initial surgery despite allocating several hours for this purpose. This fact may justify a subsequent surgical session. However, the eventual retrieval of the broken scalpel during a second surgical encounter can likewise be a very daunting challenge. Case Presantation: An L4-L5 discectomy in a young boy was complicated by the presence of an intradiscal broken surgical knife blade. The broken blade was successfully retrieved in a subsequent surgical session via the extended extraforaminal approach. Conclusion: The occurrence of an intradiscal retained broken scalpel has been rarely discussed within medical literature. There exist a wide variety of different approaches used for such a needed retrieval. The extended extraforaminal corridor has yet to be described within the context of medical journalism.