EVALUATION OF CAVITATION PERFORMANCE OF AN AXI-SYMMETRIC BODY WITH PUMPJET PROPULSOR

A Pumpjet (PJP) was designed for an underwater body (UWB) with an axi-symmetric configuration as part of a technology development program for design and development of pumpjet. Its propulsive and cavitation performances were predicted through CFD study. The propulsor design was evaluated for its propulsion characteristics through model tests conducted in a Wind Tunnel. In the concluding part of the study, evaluation of the cavitation performance of the pumpjet was undertaken in a Cavitation Tunnel (CT). In order to assess the cavitation free operational speeds and depths of the vehicle with respect to pumpjet, cavitation tests of the PJP were carried out in behind condition at CT to determine the cavitation inception numbers for rotor, stator and cowl. The model test results obtained were corrected for full scale Reynolds number and subsequently analyzed for cavitation inception speeds at different operating depths. This entire exercise facilitated the development of an innovative testing technique and a special test setup for finding cavitation performance of pumpjet propulsor. The technique was evaluated by comparative corroboration of inception position and depth obtained from CFD analysis. From the model tests it was also found that the cavitation inception of the rotor takes place on the tip face side at higher advance ratios and cavitation shifts towards the suction side as the shaft rotation rate increases whereas the stator and cowl are free from any cavitation.

A study of the physical properties and bending stiffness of antistatic and antibacterial knitted fabrics

Different fiber blends, knit patterns, and treatments may be applied to increase the functionality and comfort of knitted fabrics. In this research, the physical properties and bending stiffness of 1 × 1 rib and half-milano rib fabrics with four fiber blends (90% cotton/10% antistatic PET, 80% cotton/20% antistatic PET, 70% cotton/30% antistatic PET, and 65% cotton/35% antistatic PET) applied to each knit pattern were studied. The effect of fabric direction (course and wale), technical side (face side and back side), and treatment (dying, softening with Aquasoft® SI hydrophilic softener, and Polygiene VO-600 antibacterial finish) on the physical characteristics and bending stiffness of the fabrics was evaluated. The results revealed that dyeing and softening increased the fabric area density and both wale and course densities and decreased fabric thicknesses compared to the control fabrics. The antibacterial finish applied to the softened samples did not change the physical properties. Bending stiffness in the course direction was lower than in the wale direction, and it was higher for technical face samples than for technical back ones. The 1 × 1 rib knitted fabrics showed lower stiffness than the half-milano rib fabrics. Treatment of the investigated fabrics decreased bending stiffness for both treatment sample groups compared to the control group.

The effect of oil feeding type and oil grade on the oil film bearing capacity

Two types of hydrodynamically lubricated plain journal bearings were subject to examination differing in the method used to feed them with oil. The first type was fed from a lubrication pocket and the second from the bearing face side. Mathematical models were developed with two-way oil flow allowing to determine the oil film bearing capacity, the maximum pressure, the maximum temperature, and the film oil minimum height for given position of journal relative to solid bush. Static characteristics were developed used in the further course of the study to compare operating parameters of the considered types of bearings. Another issue considered in the paper is the effect of oil VG grade on bearing performance with conditions of oil feeding taken into account and results of the research presented.

Blindstitch machines for men suit manufacturing: Part 2

Different blindstitch machines are used in men suit industrial manufacturing process to replace traditional manual sewing techniques and ensure high work process productivity. The waistband of the trousers is felled with special machines of stitches 103. Beltloop machines process double-folded belt loops for trousers with or without inserted tape. To create 3D shape to lapels and collars of jacket padding machines are used. Spot tacking machines fix together two or more layers of fabric with stitches invisible on the face side of the garment. Machines for felling undercollars create V-shaped zig-zag stitches 314. Two kind of machines are used to fell the lining in the armhole and bottom of the sleeve. Blindstitch machines for certain technological operations are manufactured by companies: Strobel, Maier, Japsew, Global, others.

Numerical Investigation of the Hydrodynamic Performance of the Propeller Behind the Ship with and Without Wed

The presented paper numerically carries out the investigation of the hydrodynamic performance of the propeller behind the ship with and without wake equalizing duct (WED). It is mounted in front of the propeller in order to equalize the ship’s wake flow and improve the propeller performance. The computational fluid dynamics (CFD) analysis software STAR-CCM solver was adopted to simulate the KP505 propeller behind the KRISO container ship (KCS) using overlapping grid technology and user-defined functions. To obtain the effect of a –duct on propeller performance, the ship bare hull case, the with-propeller case, and the with-propeller-and-duct case are also computed. Together, these computations provide for a –complete CFD comparison of the duct effects. Also, the Taguchi design of the experiment method is applied to investigate three parameters (angle of attack, trailing edge radius, and chord length) of the duct. Finally, the main dimensions are obtained, and the thrust and torque coefficients are presented and discussed for one blade and whole blades during one cycle. Based on the numerical results, it is indicated that good design increases efficiency by 1.67%, and a –bad design may reduce efficiency by 3.25%. Also, the effect of the WED caused to decrease the pressure pulse by 35.9% in the face side of the propeller blade.

Two-Character Dialogue

Chapter 15 describes and illustrates using storyboards the basics of blocking and shooting two-character dialogue. Whether characters are standing, seated, or walking, conversations cut better when shots are designed to mirror each other and to maintain consistent screen geography. The geometry that arises from the positions, heights, and movement of characters is the basis of determining camera placement for proper matching and continuity editing. Several common configurations of characters are explored, including face to face, side by side, and walking. Standard templates of shots to cover conversations are presented. Several commonly used blocking techniques for getting two characters into and out of position for their dialogue are described and illustrated.

THE STONE FINIAL-DISCFROM THE LATE MESOLITHIC LAYER AT BEREGOVAYA II IN THE MIDDLE TRANSURALS REGION

При раскопках стоянки Береговая II на Горбуновском торфянике в Зауралье в слое позднего мезолита был найден перфорированный диск-навершие из тальк-хлоритовой горной породы. На лицевой стороне диска грубой шлифовкой моделирован выступающий нос, гравировкой показаны брови, усы и борода личины. Отверстие для рукоятки в центре расположено на месте рта. Всего в Зауралье известно 4 крупных перфорированных диска, которые исследователи относили к эпохе бронзы и интерпретировали как диски-календари. Отличительные черты нашего диска позволяют считать его скорее навершием ритуального оружия типа булавы. Находка подобного артефакта в четких стратиграфических условиях – в культурном слое позднего мезолита стоянки Береговой II – и сходство отдельных деталей антропоморфной личины на диске с деталями лица Большого Шигирского идола доказывают гораздо более раннее их бытование в Среднем Зауралье. The excavations at the Beregovaya II site in the Gorbunovo peat-bog in the Transurals yielded a perforated end-piece disc made from talc chlorite rock. The face side of the disc features a protruding nose made by rough grinding, whereas the brows, the moustache and the beard of the human-like mask are rendered by engraving. There is a shaft-hole in the center where there should be the mouth. Totally four large perforated discs referred by researchers to the Bronze Age and interpreted as calendar discs that are known in the Transurals region. The distinguishing features of this finial-disc suggest that, most likely, it was a part of a ceremonial weapon such as a macehead. The find of this artifact in the clear stratigraphic context of the Late Mesolithic occupation layer at Beregovaya II and similarity between some parts of the anthropomorphic human-like mask on the disk and the face of the Big Shigir idol is an evidence that such discs were used in the Middle Transurals much earlier.

The formation mechanism of protrusion of long thread by axial self-infeed rolling process

In the forming process of long threads by axial self-infeed rolling process, the protrusion generates on the top of the tooth profile, which affects the strength and precision of the formed threads. In this article, the principle of the axial self-infeed rolling process was described, and the finite element model was established to simulate the forming process of threads. The formation mechanism of protrusion was analyzed through material flow, which was verified by experiments. The pre-rolling angle and material’s influence on the protrusion size was also investigated. The results showed that the axial motion of the rollers squeezed one flank of the tooth, leading to higher protrusion on the face side as compared to the other side. During the rolling process, the height of the protrusion increased first and then decreased, reaching the maximum value when the height of the formed tooth was 73% of the whole tooth. In order to reduce the protrusion height, the pre-rolling angle should be 2°.

Operational Problems in Welded Joints of Flow Sensors Used in Power Engineering

The paper presents operational problems present in fluid and gas flow measurement systems. Tests (involving laser welded tubes made using a focused and a defocused beam) were concerned with the quality of welded joints. The tests revealed that the use of the focused beam resulted in the formation of cracks in the welds. In addition, post-weld observations revealed undercuts on the weld face side, responsible for the thinning of the tubes, yet without compromising their service life.

Orbital Floor Blow-Out Fractures: Ultrasonography, Postoperative Complications and Rehabilitation

The aim of this retrospective study was to analyze indications and the efficiency of post-operative rehabilitation in patients with orbital floor blow-out fractures. The selected patients were with orbital floor blow-out fractures and post-operative rehabilitation; eight case records were traced. The symptoms of the eyes (eye position and movements, coordimetry, ultrasonography) were noted before and after surgical correction and rehabilitation treatment. The data were statistically analyzed using a computer software package, SPSS version 16.0. A value of p < 0.05 was considered as statistically significant. All eight (100%) patients were men. The average age was 19.88 ± 8.25 years (14–34 years). The most common complaint was diplopia, it was in eight (100%) patients’ numb of affected face side was in two (28.6%), vertigo in one (12.5%), nausea in one (12.5%) patient. Post–operative complications were: diplopia – eight (100%) patients, postoperative scar – three (37.5%), eyelid swelling – four (50%), haematoma – one (12.5%) patient. After rehabilitation post-operative symptoms (postoperative scar, eyelid swelling, haematoma) decreased significantly (p < 0.05). Insignificant diplopia was left in seven (87.5%) (p > 0.05) patients, but it did not disturb their general activities. Patients were not treated surgically, neither they got correction with prismatic spectacles after rehabilitation. One (12.5%) patient was under supervision. Before rehabilitation ultrasonography was done for five (62.5%) patients. Ultrasonography was repeated only for one (12.5%) patient after rehabilitation. Coordimetry was done for all patients while they were being treated in order to find out the efficiency of rehabilitation. Rehabilitation can be recommended to patients with post-operative complications such as diplopia, swelling, post-operative scar. Treatment effect should be objectified by ultrasonography.Keywords: rehabilitation, orbital floor fracture, postoperative complications, ultrasonography.