Knife Blade Research Articles

EVALUATION OF DAMAGE OF ROUNDWOOD ASSORTIMENTS CAUSED BY VARIED CONSTRUCTION, TECHNICAL SOLUTIONS AND CONDITIONS OF HARVESTER HEAD FEED ROLLERS

The purpose of this study was to evaluate the depth of damages caused by harvester head feed roller spikes to birtch veneer logs, harvested according to top diameter group (18x25cm, 25cm), spruce sawlogs (6x10cm), spruce and pine sawlogs according to top diameter group (10x14cm, 14x18cm). Thirteen technical solutions and conditions of the harvester head soft feed rollers (Moipu Standard, Rib), standard feed rollers (Multi-Tree Handling (MTH), Steel Thumbnail) and agreesive feed rollers (TP) were tested in this study.Regulation parameters of hydraulic system and angles of delimbing knife blades during the harvesting of stems in different woodland types and seasonality using single grip harvesters: John Deere 1270E, John Deere 1070E and John Deere 1070D equipped with harvester heads: H754; H480C and H460 were examined in clearcutting and thinning operations in twenty four wood felling sites in Kurzeme and Vidzeme region of Latvia.

Life Course Practices in Bronze Age Landscapes of East Central Sweden: Beyond Divine Chiefs and Neodiffusionism

This paper treats the ritual traditions and practices connected with burials in Bronze Age cairns and stone-settings in the province of Södermanland in east central Sweden. The author discusses how the social and ritual roles of the individuals buried in cairns can be intertwined with the characteristics ofthe landscape contexts where caims have been placed. Particular attention is given to the meaning ofa special combination of artefacts —a razor, a pair of tweezers, a double-stud and a knife blade —found in Bronze Age burial contexts. The author suggests that the razor and the other ritual equipment may have been used in connection with life course rituals.

Fra grænselandet mellem to kulturer

Fra grænselandet mellem to kulturer

Justification of the parameters and operating modes of the disinfecting system

Increasing yields is an important task for our country. This is possible due to removing the tip of the shoot, which stimulates the potential of the plant itself, and such products can be sold as organic since no other chemicals are used to increase yields. When the shoot tip is removed, a wound is formed through which pathogens can enter. To reduce the likelihood of plant contamination, the device provides a system for applying a disinfectant solution (hydrogen peroxide) to the knife blade. The settings of the injector are taken into account. When choosing a spray gun, it is necessary to take into account the average working pressure, equal to P = 0.28 MPa, which provides a solution flow rate щa Q = 0.8 l • min-1 with a nozzle diameter of 0.1 mm. These requirements can be met by spray guns of caliber 04 or 05. At a spray angle of 800, the recommended spray angle is 300; the mounting distance is 0.3 m below the plane of rotation of the cut-off wheel. The initial flow rate of the liquid of 17.33 m • s-1 will provide stable droplet formation, providing the recommended dispersion of the solution of 150-200 microns.

Broken surgical blade retrieval following lumbar discectomy through paravertebral/lateral transpsoas approach: A case report

Background: There are rare reports of broken surgical blades occurring during lumbar discectomy, and even fewer that discuss their retrieval.Case Description: While a 54-year-old male was undergoing a lumbar discectomy, the knife blade was broken. As it was difficult to retrieve the fragment through the original incision, the patient was closed, and a postoperative angio-computerized tomography (CT) was obtained. When the CT angiogram (CTA) documented the retained fragment had become lodged near the iliac vein within the psoas muscle, a second operation for blade retrieval, consisting of a paravertebral, lateral transpsoas approach, was successfully performed.Conclusion: In some cases, it is difficult to retrieve a broken scalpel blade during the index surgery. When this occurs, we would recommend closing the patient, and obtaining a CTA to better document the location of the retained foreign body. Based upon these findings, a safer second stage procedure may be performed (e.g., as in this case using a paravertebral lateral transpsoas approach) to avoid undue sequelae/morbidity.

After Incision, the Skin Knife Blade Is No More Contaminated Than a Fresh Knife Blade.

The rationale for discarding the skin knife blade and replacing it with another blade for deeper dissection is to prevent bacteria that may be present on the skin from being carried into the deeper layers of the wound. This practice is very controversial because numerous, yet limited, studies exist that support and refute the findings. The purpose of this study was to directly compare the rate of contamination of a skin knife blade with a control blade. We took the surface samples using Replicate Organism Detection and Counting plates of 344 knife blades immediately after making skin incision during the following four types of orthopaedic cases: total hip arthroplasty, total knee arthroplasty, lumbar spine surgery, and cervical spine surgery. At the same time, we sampled 344 control blades. The comparison of positives skin versus control, overall and within each subgroup was done using a bivariate two-sample z-test for the equality of proportions. Overall, 35 (5.1%) of the 688 specimens had a positive result. No difference was noted in the rate of positive cultures for the 344 skin blades 4.9% and the 344 control blades 5.2%. No differences were observed in the rate of positive specimens for skin blades (7.4%, 3.4%, 7.7%, and 3.9%) and control blades (2.5%, 4.1%, 7.7%, and 9.2%) for total hip arthroplasty, total knee arthroplasty, C spine, and L spine, respectively. No differences were observed regarding skin prep, room number, case order, room turnover time, or in-room to incision time. Staphylococus species was the predominant bacteria identified. We found no evidence to support the theoretical advantage of changing the knife blade after making skin incision to avoid contamination. Contamination rates were the same for both the skin and control blades overall and for all subgroup analysis.

The Role of Functional Efficiency in the Decline of North America’s Copper Culture (8000–3000 BP): an Experimental, Ecological, and Evolutionary Approach

The copper-using cultures of North America’s Archaic Period (10,000–3000 BP) have long been an archaeological enigma. For millennia, Middle and Late Archaic hunter-gatherers (8000–3000 BP) around the Upper Great Lakes region made utilitarian implements out of copper, only for these items to decline in prominence and frequency as populations grew and social complexity increased during the Archaic to Woodland Transition. From a cultural evolutionary perspective, the trajectory of North America’s copper usage presents a conundrum, as it is generally assumed that “superior” tools, i.e., metals, will replace inferior ones, i.e., stone. For well over a century, scholars have pondered the reason for the demise of copper technology that was once a wide-spread phenomenon. To address this question, an extensive archaeological experimental program was conducted which compared replica copper tools (spear points, knife blades, and awls) to analogous ones made of stone or bone to assess whether relative functional efficiency contributed to the decline of utilitarian copper implements. Here, the results of this three-part research program are presented in concert with population dynamics and ecological change to paint a broader picture of the complex interrelationships between the social, ecological, and technological spheres of past human behaviors. The synthesis of these approaches reveals that functional explanations—derived from experimental archaeology placed in an evolutionary framework—can shed much light on the trajectory of metal use in the North American Great Lakes.

Facile fabrication and mass production of TPU/Silica/STF coated aramid fabric with excellent flexibility and quasi-static stab resistance for versatile protection

Stab-resistant materials with lightness and softness have received increasing attention with the progress and development of society. In this paper, we have fabricated excellent flexibility and quasi-static stab resistance fabric by coated thermoplastic polyurethanes (TPU)/Silica /Shear thickening fluid (STF) on the aramid fabric, which can be facile fabrication and mass production. Several tests, including quasi-static stab test, quasi-static puncture test, yarn pull-out test, and interlayer peeling test were conducted to evaluate the bonding fastness between TPU film and the stab resistance of the coated fabric. The results showed that the quasi-static stab resistance, puncture resistance, and yarn pulling-out performance of TPU-coated fabrics were improved greatly compared to neat fabrics. Coated fabrics had lower quality increase and less flexibility decrease as compared with neat fabrics. The stab resistance of the fabric treated with TPU coating solution with silica additive was also improved. Meanwhile, the aramid fabric coated with a coating solution containing 3 % fumed silica had the best performance in terms of knife stab and puncture force performance (135.98% higher for P1 knife blade stabbing, 127.21 % for S1 knife blade stabbing and 129.48 % for spike punching) as compared with neat fabrics.

Implementation of the new resource saving technology in manufacturing process

The authors of the article justify the expediency of applying resource saving in developing innovative technologies for hot rolling of boning knife blades from steel slabs. Such knives are widely used in meat processing industry. Metal consumption of the process was significantly reduced after changing the existing factory technology of making boning knives. The operation of cutting or grinding was replaced by hot rolling. The specific feature of the technology lies in minimizing the metal loss into shavings during the final processing of the steel slab by means of cutting. Reducing metal loss in making such steel parts and raising metal utilization rate are achieved by maximum possible approximation of forging configuration to the end product contour and preservation of the allowances regulated by the operational chart. The authors suggest optimal combinations of basic parameters of introduction of resource saving technology into production. To adduce an example the authors justify the possibility of shaping and simultaneous hardening of the knife blade during hot rolling between deforming rollers. Energy intensity of the technology suggested is lowered by means of reducing the time for further mechanic processing of the forging by cutting. Practical approbation of the introduced resource saving technology in repair production made it possible to raise the metal utilization rate to 95% and to reduce by 1.2 the production cost of a boning knife as the end product. When manufacturing the parts metal resources are saved due to the fact that irreversible loss of metal in the innovative technology of the boning knives’ production differs a lot from that in the traditional one. Technical and economic calculations adduced in the article show the effectiveness of the research and prove the profit of implementation of the new technology

Effect of Alcohol Disinfection on the Handle and Blade of Vegetables Knives by using ATP Inspection and Microbial Stamp Test

To prevent food poisoning, we focused on kitchen vegetable knives, which are likely to cause secondary contamination, and conducted hygiene inspections to obtain results. The values after cooking and after washing, and after washing and after 70%spraying alcohol compared using the ATP wiping test and the microbial stamp test (selective medium: general bacteria, Escherichia coli, Staphylococcus aureus, Salmonella, Vibrio parahaemolyticus). As a result, the ATP test value decreased statistically significantly and became 100 or less after 70%alcohol sprayings. However, not all of the bacterial counts in the selective medium were statistically significantly different even after 70%alcohol sprayings. The reason the data was not clear due to 70% alcohol spray conditions. It may be advisable to perform a microbiological stamp test after applying 70%alcohol spray multiple times instead of once to a fully moistened knife handle and blade. In the future, we would like to consider the handling of more hygienic cooking utensils by further changing the 70%alcohol spraying conditions and conducting, Microbiological tests using a selective medium.

P.735 Emotion recognition processing as a predictor of clinical response to SSRI treatment in first episode versus recurrent depression

Surgical scalpel broken is rarely reported in posterior lumbar discectomy or fusion surgeries, but when it happens and even the broken part is deeply located in the disk space, there is no guideline to remove it during the initial surgery.A 56-year-old female with L3-L4 and L4-L5 disk herniation and stenosis underwent 2-level transforaminal lumbar diskectomy and fusion. The knife blade was broken in the L4-L5 disk space during the annulus resection. Despite a 1.5-hour trial for removal with fluoroscopy, the broken part gradually migrated to the anterior border of the disk space. Eventually, arthroscopy was used for retrieval, the blade tip was clearly recognized in the arthroscopic view, which improved the accuracy of the subsequent operation. The blade fragment was removed successfully within 30 minutes.Arthroscopic retrieval of a broken scalpel deeply located in the intradiskal space is recommended as an alternative method when conventional effort is unable to remove it, especially when the broken blade migrates anteriorly, which may provoke catastrophic consequences.

Исследование параметров процесса резания швейных ниток

Sewing thread cutting processes are widely used in semi-automatic machines in the garment industry. The lack of scientifically justified methods for designing mechanisms for thread trimming in semi-automatic sewing machines makes studying these processes a topical issue. There are works that examine cutting free-hanging yarn using scissors. However, these results cannot be used to develop mechanisms for thread trimming in semi-automatic sewing machines for the following reasons: the properties of free-hanging yarn and sewing thread vary significantly, and the cutting conditions for the thread that grips the blade of a movable knife are different as well. Another reason is that as a rule, sewing thread cutting occurs in a limited space, which imposes a significant restriction on the design parameters of knives and affects the cutting process. There are no such restrictions when cutting yarn. Cutting threads by the method of scissors does not provide complete cutting of all the components of the thread if the knife blades are not in tight contact with each other. To ensure complete trimming, a design scheme of cutting was developed, and calculation formulas were obtained for determining the force exerted by the thread on the movable knife, taking into account the mechanical characteristics of the cut thread.

Laparoscopic Radical Hysterectomy with Enclosed Colpotomy Using Surgical Stapler for Early-Stage Cervical Cancer

Study Objective To report the application of Ethicon Endo-Surgery re-usable linear cutter (Ethicon endocutter) in vaginal closure without usage of uterine manipulator to prevent tumor spillage in laparoscopic radical hysterectomy for early-stage cervical cancer. Design A step-by-step explanation of the procedures using a video. Setting Hospital for women's health teaching and research. Patients or Participants This is a 41-year-old woman with clinical stage IBI cervical squamous cell cancer. Interventions After the contraindication was removed, laparoscopic type C radical hysterectomy with pelvic lymph node dissection and ovarian transposition were performed, the surgery was finished without usage of uterine manipulator. The patient signed an informed consent that allows us to use her clinical data. Measurements and Main Results In this method, after completion of the radical hysterectomy procedures, an Ethicon endocutter was placed into abdominal cavity through a 12-mm trocar. The uterus was elevated with fixed sutures on the uterus. Then, the stapler was placed. Before the surgical stapler was fired to close the vagina, we should checked that no other unintended structure was included in the jaws of the stapler. After being fired, the stapler places 2 triple-staggered rows of titanium staples and simultaneously knife blade cuts between them. Once the vagina has been divided, the stapler was released. The upper part of the vaginal cuff was excised and checked by pathology as a surgical margin, and the uterus was removed through the vagina. Finally, the vaginal cuff was closed with absorbable barbed sutures. Conclusion Vaginal closure with Ethicon endocutter before colpotomy is a useful and effective procedure to block vaginal cuff and prevent tumor spillage during laparoscopic radical hysterectomy of cervical cancer.

Influence of Intermediate Cryogenic Treatment on the Microstructural Transformation and Shift in Wear Mechanism in AISI D2 Steel

AISI D2 steels are an interesting family of tool steels that generally have applications in knife blades, shaper blades, and forging and punching dies due to its optimum toughness, lower wear rate, and relatively high hardness. The present research work aims to design a new heat treatment cycle consisting of single tempering followed by cryogenic treatment and soft tempering to improve the wear properties of these steels. Specimens of AISI D2 tool steel were subjected to three different heat treatment cycles: hardened and double tempered at 450 °C (HTT450), hardened and double tempered at 450 °C followed by cryotreatment and soft tempering at 250 °C (HTT450CT250), and hardened and single tempered at 450 °C followed by cryotreatment and soft tempering at 250 °C (HT450CT250). The microstructures of the samples were characterized for hardness, carbide density, impact energy, wear loss, wear surfaces, and residual stresses. The influence of these measured parameters on the wear behavior was determined using a pin-on-disc wear testing machine. The results confirmed that HT450CT250 is the optimized heat treatment cycle out of the three cycles studied, which showed enhanced wear resistance index, minimum compressive residual stresses, and optimum impact toughness due to increased volume fraction and finer distribution of carbides in the tempered martensite structure. It is further revealed that there is a change in morphology of carbides from globular to needle-shaped, resulting in wear transition, which is well corroborated by scanning electron microscopy studies and wear surface analysis.

USING 3D-MODELLING METHODS DURING ACUTE HEART INJURY EXAMINATION

Despite the fact that the classical methods of acute trauma research are well studied and widely used in forensic medicine, in recent years in the world and domestic forensic practice are increasingly introduced modern computer technology and three-dimensional spatial modeling, which significantly complement and improve visualization of bodily injuries, as well as increase the accuracy of identification of the weapon of injury.Aim of the work. Forensic identification of the stabbing-cutting tool found at the scene and seized by the investigating authorities, with the presence of stab wounds to the heart, using photogrammetry and 3D modeling of the wound canal in the heart muscle.Materials and methods. As the materials of the study were used barbed cutting tool and individual elements of the wound canal, which were examined using photogrammetry and subsequent 3D modeling for their compliance in the examination of acute heart injury.Research results. An example of using the method of 3D modeling is given and its advantages in comparison with classical methods used in forensic practice during the examination of bodily injuries in the forensic identification of stabbing-cutting tools are shown. It is shown that when comparing the 3D model of a knife blade provided by investigators, its length, width at the site of the greatest thickening and bevel of the blade created by photogrammetry and three-dimensional spatial modeling with 3D models of fragments of the wound canal of stab-cut heart damage, their full compliance. The measurement results obtained from 3D models of fragments of the wound canal with the help of computer programs "Agisoft Photoscan" and "3ds max" are an order of magnitude more accurate than the measurements provided by classical methods.Conclusions. The use of photogrammetry and modern 3D modeling technologies allows to obtain 3D models of the wound canal in the thickness of the heart muscle or any other parenchymal organ and stabbing-cutting tool, to make more accurate linear measurements and comparison of fragments of the wound canal with the probable injury tool compliance.The electronic archive of 3D models will allow to save the parameters of damages in their original form, use them during additional, repeated or commission examinations, virtual expert experiment, as well as send by e-mail for remote consultation and investigative bodies and juries for use during court hearings.

Analysis of the Archaeozoological Material From XI—XIII Centuties Settlement Ihren 8

The Ihren peninsula is situated in the Samara district of Dnipro city. The advantageous geographical location in the lower reaches of the Dnieper River basin was conducive to the habitation of this place in the course of Mesolithic time. From the beginning of 1930-ies, archaeological sites of Mesolithic, Neolithic, Bronze Age and namely Medieval time on the territory of the peninsula were discovered and excavated. In the case of the river erosion and potential building development on its territory, the archaeological excavations have become a necessity. In July 2018, the excavation work of the archaeological expedition of the National University of “Kyiv-Mohyla academy” was held. The head of the expedition was prof. L. Zalizniak. During the process of research, the peninsula stratigraphy was clarified and some objects and cultural stratums of XI—XIII centuries were discovered. The materials found consisted of ceramics fragments, amphorae, metal knife blades and fishing hooks. A high concentration of glass bracelets indicates the wealth of the settlement’s inhabitants. The object of this research is animal bones, which were found in the context of cultural stratums of XI—XIII centuries. The biggest percentage of bones belongs to domestic animals, such as cows, pigs, small-hoofed animals, such as sheep and goats. Red deer, elk, roe deer were the objects of hunting strategy. Their horns were used for bone tools and handcraft. Fishing was one of the important branches of the economy. 12 fish species from 5 families were identified from the fish bones, the most valuable of which belong to the sheefish, pike, sander and carp. Almost all of the fish bones were big in size. It can be possible during big fish selection in the process of fishing. The perforated fish vertebrae emphasize the important role of fish production. The results supplement previous researches and give a base for the reconstruction of certain aspects of settlement economy.

Removal of bovine digital dermatitis-associated treponemes from hoof knives after foot-trimming: a disinfection field study

BackgroundBovine digital dermatitis (BDD) is an infectious foot disease found commonly in dairy herds. Foot-trimming is an important husbandry procedure for reducing the ensuing lameness; however, epidemiological, and microbiological studies have identified this as a risk activity for transmitting BDD.Three disinfectants have previously been identified in laboratory work as effective for removing viable BDD-associated Treponema spp., from hoof knife blades. The present study enrolled 133 dairy cattle with BDD lesions, and swabbed hoof knife blades before and after foot-trimming, and after knife disinfection with one of three disinfectants (1:100 FAM30®, 2% Virkon® and 2% sodium hypochlorite) to assess their efficacy under field conditions.ResultsDetection of BDD treponeme phylogroup DNA was undertaken by direct PCR of swabs, and viable treponemes were detected by PCR of swab cultures after 6 weeks’ incubation.Where hoof knives did not contact the lesion, BDD-associated treponemes were detected after foot-trimming in 12/22 (54.5%) cases by direct PCR and 1/22 (4.5%) cases by PCR of cultured organisms. Where contact was made with the lesion, 111/111 (100%) samples taken after trimming were positive by direct PCR and 47/118 (39.8%) were positive by culture PCR. Viable organisms were identified in cultures from lesion stages M2, M3, M4 and M4.1. No viable organisms were detected after disinfection of hoof knives.ConclusionsHoof knives post-trimming were frequently contaminated with BDD-associated treponeme DNA. Viable organisms were identified in cultures whether contact had been made between hoof knife and lesion or not, although contact clearly increased the frequency of detection of viable organisms. The three disinfectants tested were effective for removing viable organisms. The disinfection protocol used in this study should therefore be considered reliable for adoption as standard industry practice.

Reducing Surgical Time: An Innovative and Versatile Instrument for Creating Multiple Brick-Pattern Sagittal Recipient Sites in a Single Stroke

<b><i>Introduction:</i></b> Recipient-site creation is a very important step in the hair transplant procedure as it ultimately decides the density, direction, and exit angle of the implanted hair and the final result of the procedure. It can be done with knives or needles. The slits can be <i>sagittal</i> (parallel to hair direction) or <i>coronal</i> (perpendicular to hair direction). For better visual density and coverage, the majority of hair restoration surgeons use sagittal slits. <b><i>Methods:</i></b> Recipient-site creation takes up a significant amount of the surgeon9s time. A considerable reduction in surgical time for coronal slit creation has been described using a multi-slit knife.¹ A multi-slit knife for sagittal slits has not been described until this paper. Our technique reduces surgical time by the use of an innovative and versatile new instrument that enables the creation of single rows of equidistant “brick-pattern” sagittal slits of the same direction, angle, and depth in a single stroke. <b><i>Results:</i></b> The device that we have designed enables the surgeon to reduce the time needed for recipient-site creation while increasing precision. It is a versatile instrument that can be used with appropriate configurations in bald, thinning, and vertex regions. <b><i>Discussion:</i></b> The vast majority of hair restoration surgeons typically use cut-to-size knife blades to create recipient sites, which is repetitive and time-consuming. Brick-pattern slits are preferred to minimize the “see-through effect,” which adds time and challenges.³ Our instrument is easy to assemble and use, and can create slits at desired density, depth, and angle.

THE DESTRUCTIVE EFFORT OF THE CUTTING IN THE INTERACTION BETWEEN THE BLADES OF DISC KNIFE AND HERBAL MASS

The process of cutting is widely used during the stockpiling and preparation of fodder - the processing of stems by the direct application of the force that arises at the cutting edge of the knife. Almost 85% of stem fodder are ground fodder for the stockpiling of which the forage harvesters are used. Grinding of leaf mass is one of the most energy-consuming operations in the general process of stockpiling and the final quality of the fodder depends on it. The energy intensity of the grinding process is influenced by both the constructive and operating parameters of the machine, the cutting pair, and the physical and mechanical properties of the leaf-stem mass. Therefore, the development of grinding machines, the biter-knife in particular, should be carried out on the basis of detailed studies of the process of cutting grass mass, taking into account the current power and energy parameters. The object of the study in this article was the process of cutting a herbal mass with a biter-knife grinding machine containing an active disk knives. The purpose of the work was to establish the analytical dependence of the destructive cutting force in the interaction of the blade of the disk knive of biter-knife grinding machine with herbal mass. The task of the work was: to analyze the researches and publications on establishing the effort of cutting a layer of leaf stem and influence of various factors on its magnitude; to establish a mathematical model of calculation the critical effort of cutting a layer of grass mass with a cutting pair: double finger of the feed rotor - a disk knife during the cutting with sliding. The research methodology was based on the analysis of the interaction of the working parts of the grinding machine with herbal mass using the methods of theoretical mechanics. In the scientific work the interaction of single-blade blade of a disk knife of a biter-knife grinding machine with a leaf-stem mass is considered under the condition of double-backed cutting with sliding. The force interaction of the knife`s blade with the grass mass was analyzed and the dependence (3) of the calculation of the critical destructive cutting force Rkr was determined. From the obtained expression it is established that its magnitude is influenced by both the constructive parameters of the cutting steam and the technological parameters of the grinding machine. Also the magnitude of the destructive force is affected by the transformed angle of sharpening of the blade of the disk knife and the sliding angle.

On a knife edge: A preliminary investigation of clothing damage using rounded-tip knives

Bladed weapons are frequently encountered in violent crime offences including street based and armed robberies, murder, sexual assaults and terrorism. A study was conducted involving four frequently encountered clothing fabrics: t-shirt (knitted cotton), denim jeans (twill woven cotton), long sleeved top (knitted synthetic blend), and skirt (non-woven faux leather) and five knives to investigate any damage resulting from a downward stabbing motion, with 300 stabs in total. Any resultant penetrating severance damage was then photographed, measured and analysed. Statistical analysis revealed significant differences between the stab hole size and shape, as a consequence of the design of a bladed weapon (in particular, the tip shape) that caused it. There is a notable correlation between the Assure knife (rounded tip) and no resulting severance damage, as the fabric surfaces were not breached with this knife. This suggests a clear alternative to pointed tip knife blades. These findings will be of interest to investigators of knife crime offences, crime-reduction units, knife manufacturers and practitioners, who share the goal of identifying a safer alternative to conventional knife blade design.