Comparison of insertion time, pull-out strength, and screw-media interface area of customized pedicle screw with different core and thread design against commercial pedicle screw: a pilot study on Indonesian Population

Objective This research aimed to developing customized pedicle screw based on Indonesian vertebral anatomy and compare the insertion time, pull-out strength, and screw-media interface area of different screw design. We have developed 3 different types of pedicle screws (v-thread cylinder-core, square-thread cylinder-core and square-thread conical-core). The thread diameter was calculated from pedicle width of Indonesian population (6 mm). We used commercially available pedicle screw as control group (6.2 mm). Result The insertion time were significantly difference between v-thread cylinder-core pedicle screw (22.94 s) with commercially available pedicle screw (15.86 s) (p < 0.05). The pull-out strength was significantly difference between commercially available pedicle screw (408.60 N) with square-thread conical pedicle screw (836.60 N) (p < 0.05). The square-thread conical-core group have the highest interface area (1486.21 mm2). The data comparison showed that the square-thread conical-core customized pedicle screw group has comparable insertion time and has better pull-out strength than commercially available pedicle screw.

The Characterization of Some Ancient Egyptian Funerary Linens from the Twenty-First Dynasty Discovered in the Bab El-Gasus Excavation

The ancient Egyptians had a distinct and flourishing textile industry with diverse characteristics. The developments in archaeological textile studies over the last few decades have assisted in identifying the techniques used in the manufacture of fabrics and demonstrated the complexity of this ancient industry. The ancient Egyptians are well-known for the production of linen fabrics of varying structures and purposes for everyday use by different social classes. The Bab El-Gasus tomb at Deir El-Bahari, the tomb of the priests and priestesses of Amun, is one of the most important excavations for this subject as within the tomb several types of funerary linen textiles from the Twenty-First Dynasty (1070–945 BC) were discovered. This paper aims to characterize some of these linen pieces that were preserved and displayed at the Egyptian Museum in Cairo. The pieces are of high-quality linen, were decorated, and retain their original colours. Investigations were carried out to study their main textile characteristics such as thread diameter, twist direction, thread count and weave type, in addition to characterizing the diagnostic features of the textiles such as fringes, selvedges, self-bands, hues, decoration and their state of deterioration. A Dino-Lite portable digital microscope was used to examine the linen textiles. There were various significant findings and the study revealed some of the distinctive characteristics and versatility of ancient Egyptian textiles, offering new insights for the textile production techniques used at that time.

The role of high-resolution ultrasonic examination in the analysis of the structure and causes of complications after cosmetological thread implantation into the face and neck soft tissues

Objective The goal is to optimize the diagnosis of complications after thread implantation using high-resolution ultrasound (US).Material and Methods The study design included the formation of twelve sample comparison groups. Inclusion criteria for the group: women without evident somatic pathology after cosmetic implantation in various periods after the procedure. The difference between the groups was in the chemical composition of the material (L-lactic acid, polydiaxanone, copolymer of L-actide with ԑ-caprolactone, polypropylene, polyester fiber in a silicone sheath, metal), complaints (the presence of amyctic, the presence of overcorrection, the absence of complaints), the period of time after implantation (up to 6 months, from 6 to 12 months, more than a year). Then ultrasound was performed, 33 qualitative and 7 quantitative indicators were analyzed. The study involved 93 women aged 29 to 65 years after the thread implantation. The circulation period varied from 3 days to 20 years.Results An analysis of the relationship between quantitative and qualitative features revealed statistically significant connections between the presence of an acoustic shadow and threads of polylactic acid and polypropylene, the presence of reverberation, and the metal – gold (p < 0.0001). Relationships were established between polyester fibers in a silicone sheath with complaints of inflammation, the presence of edema during examination, perifocal edema around the thread during ultrasound (p < 0.0001). The difference was also found between the diameter of the thread in the group of patients examined up to 6 months and the group in the period 6–12 months after implantation (p < 0.0001), as well as the group up to 6 months and more than a year (p = 0.0033).Conclusion The presence of an acoustic shadow, a thread diameter of more than 1 mm are ultrasound signs of fibrotic changes around the thread. The characteristic echographic signs of inflammation around the thread will be a zone of reduced echoicity, corresponding to perifocal edema. Hypercorrection is a consequence of fibrotic changes development around the thread.

SOFTWARE MODULES AND PROCEDURES OF A COMPUTER PROGRAM FOR DETERMINING THE TENSION OF A KEVLAR THREAD WHEN KNITTING USING A RECURSOR ALGORITHM

Improving the process of knitting fabrics from Kevlar complex threads on flat knitting machines is to create the minimum necessary tension in the area of formation of the knitted fabric. To ensure this, it is necessary to determine the change in relative tension in the refueling zones of Kevlar complex threads on flat knitting machines. These zones are formed by arranging the thread guides, tension compensation devices, tension devices and thread break control devices in the working area of the supply system to form a spatial filling line for each specific knitting machine. This complex task for flat knitting machines should be based on the use of specially designed computer programs. Given the specifics of processing Kevlar complex threads on flat knitting machines, when determining the relative tension in each zone, it is necessary to use a recursion algorithm, when the output tension of Kevlar complex threads from the previous zone will be the input for the next zone. When determining the tension of Kevlar complex threads, their interaction with the guides of Kevlar complex threads, tension compensation devices, tension devices and devices for controlling the breakage of Kevlar complex threads, it is necessary to take into account the value of Kevlar complex thread diameter, its physical and mechanical properties, deformation, deformation the coefficient of bending stiffness when determining the actual angle of coverage of the guide surface. Ensuring the minimum necessary tension in the area of formation of the knitted fabric will allow to obtain the parameters of the loop structure of property and tactical equipment of servicemen capable of protecting the human body from fire, cold, cutting, barbed weapons, shock and shotgun impact. Minimizing the tension in each zone of the line of Kevlar complex threads on flat knitting machines will reduce the probability of breakage, which is important for improving knitting processes from the standpoint of improving the productivity of flat knitting machines and product quality. Mathematical support of a computer program requires the development of models of thread guides, tension compensation devices, tension devices and thread break control devices, taking into account the real physical and mechanical properties of Kevlar complex threads and real geometric and structural parameters of structural elements of the feed system.

Comparison of Insertion Time, Pull-out Strength, and Screw-media Interface Area of Customized Pedicle Screw With Different Core and Thread Design Against Commercial Pedicle Screw

Objective: This research aimed to developing customized pedicle screw based on Indonesian vertebral anatomy and compare the insertion time, pull-out strength, and screw-media interface area of different screw design. We have developed 3 different types of pedicle screws (v-thread cylinder-core, square-thread cylinder-core and square-thread conical-core). The thread diameter was calculated from pedicle width of Indonesian population (6 mm). We used commercially available pedicle screw as control group (6.2 mm). Result: The insertion time were significantly difference between v-thread cylinder-core pedicle screw (22,94 s) with commercially available pedicle screw (15.86 s) (p<0.05). The pull-out strength was significantly difference between commercially available pedicle screw (408.60 N) with square-thread conical pedicle screw (836.60 N) (p<0.05). The square-thread conical-core group have the highest interface area (1486.21 mm2). The data comparison showed that the square-thread conical-core customized pedicle screw group has comparable insertion time and has better pull-out strength than commercially available pedicle screw.

Algorithmic and Computer Software for Determination of Thread Tension After Guide Large Curvacity

The conducted studies of the effect of the structure of the threads on the amount of tension when interacting with guides and working bodies of weaving machines and knitting machines, which have a large curvature in the zone of contact with the thread, established a mechanism for the process of increasing the tension of the thread after the guide by changing the radius of curvature of the guide and friction forces in the zone contact. It is proved that the increase in tension is explained by a change in the angle of coverage of the thread of a guide of large curvature, and for complex threads and yarns, the real angle of coverage will be greater than the calculated one, due to deformation of the thread diameter in the contact zone, and for monofilaments it is less than the calculated one due to bending stiffness. The sequential passage of the thread along the guides, from the entry zone to the formation zone of fabric and knitwear, leads to a stepwise increase in tension. In this case, the output parameter of the tension after the previous guide will be the input parameter for the subsequent guide, which makes it possible to use recursion when determining the tension in front of the formation zone. In this regard, research on the computer implementation of the algorithm for determining the thread tension on technological equipment using recursion should be considered relevant.

New approach to treatment of ventral hernias of the medial localization

Importance. Functional results of treatment of the ventral hernias of the medial localization after endoprosthetics of the abdominal wall by the standard polypropylene prosthesis remain unsatisfactory because of the limited flexibility of the abdominal wall. Purpose. To improve functional results of treatment of patients with ventral hernias of the medial localization by applying a light strengthened endoprosthesis. Materials and methods. There was done a comparative analysis of the results of treatment of 60 patients with medial hernias of the anterior abdominal wall. Patients were divided into two groups with 30 people in each group. In the first group over-aponeurotic endoprosthetics of the abdominal wall defect was provided with the use of a standard polypropylene prosthesis with the thread diameter 120 micron, while in the second group there was used a light strengthened endoprosthesis with the thread diameter in the basic zones 90 micron and in the strengthened zones 120 and 90 micron. Effectiveness of treatment in the nearest post-operative period was evaluated by the degree of severity of inflammatory implantation response, and in the long-term period evaluation was done on the base of functional state of the abdominal muscles, quality of life of patients and results of treatment by four point scale. Results and their discussion. Inflammatory exudative response on implantation of the light strengthened endoprosthesis was less and reparative response was 1,1 times higher compare to a standard prosthesis. Endoprosthetics of the abdominal wall with a light strengthened endoprosthesis improved contractility of the abdominal muscles in 1,2 times. Restoration of the functions of the abdominal muscles had a positive influence on quality of life, namely, physical component of health improved by 4,5%, as well as on long-term results of treatment by the increased number of excellent and good results of treatment by 20% and reduction of satisfactory results by 20%. Conclusions. The use of a light strengthened endoprosthesis enables to improve the functional results of treatment of ventral hernias of the medial localization.

Prediction of Sewing Thread Consumption for Over-Edge Stitches Class 500 Using Geometrical and Multi-Linear Regression Models

Rapid and precise methods (geometrical and statistical), which aim to predict the amount of sewing thread needed to sew a garment using different over-edge stitches of class 500 (501, 503, 504, 505, 512, 514, 515, and 516), have been provided. Using a geometrical method of different over-edge stitch shapes, sewing consumption value was determined to avoid the unused stocks for each stitch type. The prediction of the sewing thread consumption relative to each investigated over-edge stitch was proposed as a function of the studied input parameters, such as material thickness, stitch density, yarn diameter, and seam width (distance between the needle and the cutter and the distance between two needles). To improve the established models using a geometrical method, a statistical method based on multi-linear regression was studied. Geometrical and statistical results were discussed, and the coefficient R2 value was determined to evaluate the accuracy of the tested methods. By comparing the estimated thread consumption with the experimental ones, we concluded that the geometrical method is more accurate than the statistical method regarding the range of R2 (from 97.00 to 98.78%), which encourages industrialists to use geometrical models to predict thread consumption. All studied parameters contributing to the sewing thread consumption behavior were investigated and analyzed in the experimental design of interest. It was concluded that the most important parameter affecting thread consumption is the stitch density. The material thickness and the seam width (B1) have a little impact on thread consumption values. However, the seam thread diameter has a neglected effect on thread consumption.

Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens

The present work examines the variations in the aerodynamic characteristics of four insect-proof screens by means of wind tunnel tests and digital image processing. The tested insect-proof screens were examined in three different conditions: (i) in their new, unused state; (ii) under conditions of accumulated dust and dirt after a period of 3 to 4 years of use; and (iii) under clean conditions after a period of 3 to 4 years of use and a cleaning treatment with high-pressure water. The deterioration of the screens caused the mesh to become less tense, therefore increasing its thickness and improving its aerodynamic behaviour despite a slight increase of the thread diameter and a subsequent decrease of the 2-dimensional porosity. The pressure drop coefficient, Fφ, of the used but clean screens was 1.5% to 8.8% lower (for u=1.0 m/s) than that of the new ones, thus increasing the discharge coefficient, Cd,φ, by between 0.8% and 4.8% as a result of the presence of the screens. On the other hand, comparison of the used screens in their clean and unclean states showed that the accumulation of dirt has a major bearing on their aerodynamic characteristics: Fφ increased by between 16.5% and 61.2% (for u=1.0 m/s) for the unclean screens, resulting in a Cd,φ reduction of between 7.5% and 21.3% and therefore a lower natural ventilation capacity of the greenhouse. A regular cleaning treatment of the insect-proof screens is a simple measure that improves the natural ventilation capacity of the greenhouse.