Form Of Tape Research Articles

Predicting Heat Transfer Enhancement with Twisted Tape Inserts Using Fuzzy Logic Techniques in Heat Exchangers

Fuzzy logic, introduced by Lotfi Zadeh in 1965, is a powerful method for modelling complex experiments. This study utilizes fuzzy logic to simulate and predict heat transfer in a double-pipe heat exchanger equipped with wavy inserts. The inserts, in the form of twisted tapes, have varying twist ratios (TR=9, 7, 6). The study investigates a range of Reynolds numbers (Re) from 6000 to 18000, with friction factors ranging from 0.03620 to 0.08231, and Nusselt numbers (Nu) between 66.13 and 253.28. The results for different twist ratios are compared to the ideal case. The experimental results indicate that the highest heat transfer occurs with a twist ratio of 6, leading to a significant increase of 162% in the Nusselt number and a 36.21% rise in the friction factor compared to the ideal scenario. In the fuzzy logic framework, the input variables are the twist ratio (Tr), temperature, and Reynolds number (Re), while the output variables are the friction factor (f) and Nusselt number (Nu). The study demonstrates that the Mamdani fuzzy inference system is an exceptionally effective tool for predicting experimental outcomes, given its low error rate. Upon analysing the data, it is observed that the graphs plotting the Nusselt number versus Reynolds number and friction factor versus Reynolds number, derived from both experimental data and the fuzzy logic model, exhibit nearly identical trends with a margin of error of just 3%. This high level of accuracy underscores the reliability of the fuzzy logic model in replicating the experimental results.

Endo- and exothermal mechanocaloric response in rubbers

AbstractWe investigated mechanocaloric properties of two silicone rubbers using an in-house made apparatus. Tension $$f$$ f and temperature change $$\Delta T$$ Δ T of the rubber samples in the form of tapes were measured as they were extended up to a normalized length $$\lambda \approx 2$$ λ ≈ 2 at a constant rate. Endothermal and exothermal components of the thermal response were observed and separated. The engineering stress and (decrease of) the entropy density derived from the data were analyzed. The number densities of the partial chains and the coefficients of the positive (endothermal) entropy contribution were determined as material constants of the rubbers. Non-idealities were revealed by the large difference between the work done on the rubber for the extension and the heat that evolved in the process. It decreased to a considerable extent when the heat was corrected for the endothermal effect arising from the above-mentioned endothermal entropy contribution. This may be understood as an indication of hidden near-ideality of silicone rubbers. Dissipation of the work into heat is quantified using the difference between the temperature changes on extension and contraction.

Molecular disruptions in PTFE as the basis of a therapy-level skin dosimeter

75 μm thick PTFE tape attracts interest, forming the basis of a potential skin dosimeter capable of utilization in radiotherapeutic external beam applications. The medium is readily available, for instance in the form of ordinary plumber's tape as used herein, typically of 12 mm width mounted on a spool. A60Co (mean energy 1.25 MeV) irradiator has been used to deliver doses in the range 0.1- to 10 Gy, with disrupted molecular bonds inspected via Raman spectrometry. The peak of greatest magnitude, at a wavenumber of ∼734 cm−1, corresponds to the difluoromethylene (CF2) symmetric stretching mode. Reduction in the peak intensity is seen to occur over the range 0.1- to 5 Gy, covering the values of skin dose typically arising in a single fractionated radiotherapeutic treatment. Results from these preliminary investigations point to a technique offering viability for radiotherapy skin dosimetry, utilizing a soft, low atomic number medium of particularly low-cost, also available in hypoallergenic form.

Study of the thermal protection characteristics of composite aerated concrete lintels when optimizing the life cycle of a building

The article is devoted to the study of the effectiveness of various methods of reinforcing composite aerated concrete lintels intended for window and door openings in the construction of civil buildings. The authors have developed a composite aerated concrete lintel for window and door openings, which includes two or three aerated concrete blocks and a seam at the ends made with polyurethane glue. The lintel reinforcement is made in the form of tape and parts of carbon fiber tape attached to aerated concrete blocks. The article provides a comparative analysis of various methods of reinforcing lintels made of aerated concrete, including steel rods and glass-composite reinforcement, as well as external tape reinforcement using carbon tapes. The results of the study allow us to conclude that external tape reinforcement with carbon fiber tapes is the most effective method. The most thermally efficient type of lintel reinforcement is external tape reinforcement with carbon fiber tapes, since the reduced heat transfer resistance is 6-10% higher than that of similar lintels with another type of reinforcement, and 10-28% higher than traditionally used lintels (reinforced solid lintels and composite U-shaped lintels).

CHOICE OF THE PARAMETERS OF TWISTED TAPES FOR HEAT TRANSFER INTENSIFICATION IN THE CHANNELS OF THE POWER EQUIPMENT COOLING SYSTEM

The paper presents the results of analyzing the efficiency of heat removal processes in the channels of the power equipment cooling system. The processes of heat transfer in the ventilation ducts of the cooling system for traction motors of diesel locomotive power plants are considered. The feasibility of using artificial intensification of heat transfer processes in the ducts with the help of spiral tapes is analyzed. Convective heat transfer intensifiers of this type are characterized by a significant increase in heat transfer coefficients, ease of manufacture, and low material consumption. Such devices can be used both in the design of new units and in the modernization of existing heat exchange equipment. The efficiency of intensification of heat transfer processes was evaluated by the level of reduction in the power of cooling system fans. The estimates were made assuming the same heat transfer coefficients in the channels with spiral strip inserts and in the channels without inserts. The length of the spiral tapes and the channel is the same. The effect of finning of the channel surface by the inserts was not taken into account. Known criterion equations were used to calculate the convective heat transfer coefficients and hydraulic resistance. It is shown that, despite the increase in hydraulic resistance coefficients and pressure losses in the channels of the air cooling system, the use of spiral tapes due to a noticeable decrease in the speed and, consequently, the cooling air consumption provides a reduction in fan power in a wide range of geometric parameters of spiral tapes while ensuring the required temperatures of equipment elements. The influence of the temperature of the walls of the cooling system channel on the required fan power when using artificial heat transfer intensifiers in the form of spiral tapes is estimated. Recommendations for the selection of geometric characteristics of spiral tapes are proposed, at which, taking into account the values of the channel wall temperature, a decrease in the power of the cooling system fans should be expected.

Effect of Residue Acrylic Monomers in Synthesized Solvent-Free Photoreactive Pressure-Sensitive Adhesives on the Main Properties of Transfer Tapes Applied to Joining Wooden Elements.

This publication describes the influence of residue monomers in synthesized pressure-sensitive adhesives based on acrylics on their main properties-tack, peel adhesion, shear strength and shrinkage-in the form of transfer tapes used for joining wooden elements in the furniture industry. The discussed carrier-free adhesive tapes are synthesized via photo-crosslinking and photopolymerization with UV radiation of the photoreactive prepolymers sandwiched between two adhesive siliconized polyester films. The simultaneous crosslinking and polymerization processes carried out under UV lamps placed simultaneously above and below the crosslinked photoreactive polymer layer lead to the production of a carrier-free adhesive film. The preliminary target of these studies was to investigate how the intensity of UV radiation and the time of its exposure affect the viscosity of the photoreactive compositions and the content of unreacted monomers in them. Next, the influence of the crosslinking agent concentration and UV irradiation time on the content of unreacted monomers after the crosslinking process was tested. The last step of the studies was the investigation of the influence of the residue monomer concentration on the application properties of the obtained pressure-sensitive adhesive layers. The typical PSA application properties were tested on the wood samples: tack, peel adhesion, shear strength (cohesion) and shrinkage.

Process chain for forming and consolidating fiber-reinforced thermoplastics and metallic sheets in a two-stage isothermal tool

Due to their good mechanical properties and low structural weight, multi-material structures are a promising approach in the automotive industry to lightweight design, body construction and functionalization. Especially metal and plastic are mainly combined to achieve improved properties of the final component compared to mono-material structures. This paper describes the development of a manufacturing cell for the joint forming and heat-assisted press joining of steels and continuous fiber-reinforced thermoplastics in the form of unidirectional carbon-fiber tapes. In order to achieve shorter cycle times and to ensure economical production, a manufacturing cell, supplemented with automated handling by means of two robots and an isothermal, two forming stages tool concept was developed and tested. The composite components produced were tested with regard to their mechanical performance. The feasibility of the production was demonstrated. All composite components had a higher specific load capacity than a pure steel component. Cycle times of well under 60 seconds were achieved. An enormous reduction in process time compared to variothermal tool concepts could be achieved with the new manufacturing cell.

Concrete Beams Reinforced with High Strength Rebar in Combination with External Steel Tape

The use of combined reinforcement in the form of external S275 steel tape and A1000 high-strength rebar is generally interesting for research. The use of a package of reinforcement enables a better choice of a rational cross-section area of reinforcement by varying the rebar diameter or the width of the steel tape. In addition, an interesting issue for research is the limit strain values of reinforcement of different strength classes since they can differ significantly, which affects the operation of the structure as a whole. For structures with combined reinforcement, there is still the number of issues not studied yet: for example, the stages of inclusion in the work of reinforcement and the magnitude of forces perceived by particular type of the reinforcement, the process and reasons for the destruction of experimental samples, the feasibility of such reinforcement, and the effect of high-strength rebar on the strength and deformability of reinforced concrete structures. Given that the issue of combined reinforcement is not sufficiently studied, the main task of the study was to investigate the stress–strain state of reinforced concrete beams with combined reinforcement (high-strength A1000 steel bars in combination with external S275 steel tape) in more detail.

Carbon Hybrid Materials-Design, Manufacturing, and Applications.

Carbon nanotubes (CNTs) have extraordinary properties and are used for applications in various fields of engineering and research. Due to their unique combination of properties, such as good electrical and thermal conductivity and mechanical strength, there is an increasing demand to produce CNTs with enhanced and customized properties. CNTs are produced using different synthesis methods and have extraordinary properties individually at the nanotube scale. However, it is challenging to achieve these properties when CNTs are used to form macroscopic sheets, tapes, and yarns. To further improve the properties of macroscale forms of CNTs, various types of nanoparticles and microfibers can be integrated into the CNT materials. The nanoparticles and microfibers can be chosen to selectively enhance the properties of CNT materials at the macroscopic level. In this paper, we propose a technique to manufacture carbon hybrid materials (CHMs) by combining CNT non-woven fabric (in the form of sheets or tapes) with microfibers to form CNT-CF hybrid materials with new/improved properties. CHMs are formed by integrating or adding nanoparticles, microparticles, or fibers into the CNT sheet. The additive materials can be incorporated into the synthesis process from the inlet or the outlet of the reactor system. This paper focuses on CHMs produced using the gas phase pyrolysis method with microparticles/fibers integrated at the outlet of the reactor and continuous microfiber tapes integrated into the CNT sheet at the outlet using a tape feeding machine. After synthesis, characterizations such as microscopy and thermogravimetric analysis were used to study the morphology and composition of the CNTs, and examples for potential applications are discussed in this paper.

Sosialisasi Pemasaran Digital, Literasi Keuangan Dan Pelatihan Pembuatan Besek Tape Bagi UMKM Desa Kasiyan Kecamatan Puger,Jember

The impact of the COVID-19 pandemic is still being felt by MSMEs in Indonesia to this day. MSMEs need to survive in the midst of the crisis by encouraging MSMEs to adapt and transform following business trends that are currently developing. One of them is MSME fish basket craftsmen and fermented cassava (Tape) producers in Kasiyan Village, Puger District, Jember Regency who require knowledge and understanding of digital marketing and financial literacy, as well as product innovation training in the form of Besek Tape as a means of broadening their horizons so that MSMEs can develop their businesses and are ready to face business challenges in the future.

Анализ плотности популяции Diptera: Muscidae в объектах животноводства

Abstract. Pig breeding is inevitably accompanied by an attack on animals by a large number of flies. Effective fly control requires biological information about the dynamics of the fly population over the seasons. The aim of the study was to determine the number and species composition of flies in the conditions of the Khatas pig farm in the winter. Methods. In the Khatas pig farm, during the technological cycle of production in December 2021, studies were carried out to determine the number of flies. To count the number of flies in the pigsties of the breeding, reproduction and fattening shops, traps were installed in the form of sticky tapes 84 cm long. There were 15 pigsties in three workshops of the pig farm. In each pigsty, one trap was placed at a height of 1.5 m from the floor. The number of insects caught on the glue trap was counted after 24 hours under laboratory conditions. Data analysis was carried out according to the method of V. N. Beklemishev. A trap with an exposure of 24 hours was taken as the unit for counting the number of flies. Results. For the first time, research has established the spread of flies in winter during the technological cycle of production at Khatas pig farm LLC. During the day, 1102 flies were caught by traps in three workshops. The species composition of flies in winter was represented by one species of Musca domestica L .The abundance index of adult flies in the rearing shop was 30.25 ± 7.56 flies per trap-day, and in the reproduction and fattening shops – 34 ± 5.78, and 57.2 ± 8.55 flies per trap-day, respectively. The scientific novelty lies in the fact that the number of adults of flies and their species composition in the Khatas pig farm of Yakutia in the winter period were determined for the first time in the obtained materials.

GIANT MAGNETORESISTANCE OBSERVED IN THIN FILM NiFe/Cu/NiFe STRUCTURES

In this paper, the technology for fabricating NiFe/Cu/NiFe layered structures by magnetron sputtering is presented. Two series of samples were fabricated on a glass substrate with a layered structure, where the individual layers were 30 nm NiFe, 5 nm Cu, and finally NiFe with a thickness of 30 nm. The series differed in the type of technology mask used. A constant magnetic field was applied to the substrate during the sputtering of the ferromagnetic layers. Measurements of the DC resistance of the obtained structures in the constant magnetic field of neodymium magnet packs with a constant magnetic field of about 0.5 T magnetic induction have been carried out. Comparison of the two series allows us to conclude the greater validity of using masks in the form of Kapton tape. The obtained results seem to confirm the occurrence of phenomena referred to as the giant magnetoresistance effect.

Complications of Suburethral Sling in the form of Mini Vaginal Tape (MVT): A Case Report

Synthetic mid-urethral sling has become the most widely used technique for the surgical treatment of stress urinary incontinence. Despite its higher success rate significant complications have been reported including- migration, encrustation, and vesico-urethral fistula formation by a mid-urethral sling (MUS). Following the mid-urethral sling procedure, periurethral stone and urethrovaginal fistula formation are very uncommon. After an online search, we could not find any reported case of migration, encrustation and vesico-urethral fistula formation by mid-urethral sling (MUS). In this case a 55 years female presented with lower abdominal pain and incontinence, 10 years after mid-urethral sling procedure in the form of mini vaginal tape (MVT). We successfully removed the stone formed by encrustation of the displaced sling and repaired the fistula. Following the sling procedure, patients need long term follow up. Although rare, a high degree of suspicion is mandatory for diagnosis and management of complications. Bangladesh J. Urol. 2021; 24(2): 232-234

Influence of Silicone Additives on the Properties of Pressure-Sensitive Adhesives.

Research was carried out on the influence of various silicone compounds on the properties of pressure-sensitive adhesives. Silicone-based pressure-sensitive adhesives have good self-adhesive properties and are used in many different industries. However, their thermal resistance is relatively low. In order to improve this property, modifications were made to these adhesives. Compositions were tested, such as viscosity or thermogravimetric analysis, as well as tests of finished products in the form of self-adhesive tapes, i.e., peel adhesion, tack, cohesion at room and elevated temperature, SAFT test (Shear Adhesive Failure Temperature), pot-live (viscosity) and shrinkage. During the tests, an increase in thermal resistance (225 °C), lower shrinkage (0.08%), and lower viscosity was achieved (16.5 Pas), which is a positive phenomenon in the technology of pressure-sensitive adhesives. Thanks to this research, the properties of silicone self-adhesive adhesives have been significantly improved.

Correlation between Tc and local structure of MgB2 with ZnO buffer layer: X-ray absorption fine structure study

In practical application, it is necessary to preserve the superconducting properties, including the critical temperature (Tc) of MgB2 in the form of tapes and wires that bond to a metallic substrate with a buffer layer. In this work, we investigate the relationship between the Tc and local structure of MgB2 films on ZnO buffered-Hastelloy substrate with various thicknesses using X-ray absorption fine structure. X-ray absorption near edge structure spectra reveal fluctuation of the boron σ-band near the Fermi level indicating an existence of lattice distortion inside the MgB2 films. Variations in the bond lengths of Mg–B and Mg–Mg from the extended X-ray absorption fine structure prove that the distortion in the MgB2 lattice is owing to the ZnO buffer layer. Besides the bond length, the Mg–B bond ordering was found to significantly affect the Tc behavior, which was attributed to the inter-plane strain caused by the ZnO buffer layer. Understanding the effect of the ZnO buffer layer on the local structure of MgB2 may help in determining the optimal conditions for enhancing the superconducting properties of MgB2 for power applications.

Optimisation of Slurry Compositions for Improving the Mechanical Properties of Low Temperature Co-Fired Ceramic (LTCC) Tapes

In the era of miniaturization and hybridization, the quest for novel materials for multilayer packaging had been increased. The multilayer packaging includes High Temperature Co-Fired Ceramics (HTCC), LTCC and ULTCC. LTCC which is the mixture of ceramic and glass (which reduces the firing temperature of ceramics) has attracted many researchers due to its lower firing temperature(<900°C). Due to this lower sintering temperature, it can be cofired with the low resistance metals like Ag and Au which increases its value in multilayer packaging field. The standard package fabrication process uses LTCC in the form of tapes. Each layer can be processed separately for punching, via filling and Screen printing and then stacked, laminated and sintered to get a multilayer package. The green sheet of LTCC should have sufficient adhesion to carrier film as well as mechanical properties to withstand the fabrication processes that it undergoes. These properties are mainly affected by the organic compositions used in the slurry preparation. The tape casting slurry was prepared by blending the LTCC powder with solvents, dispersants and binders for a predefined time in ball mill. The as prepared slurry was casted on a Mylar sheet in a continuous tape caster for varied thickness. The present study aims at reporting the effect of plasticizers and binders on the adhesion and mechanical properties of the tape. The starting material which was the mixture of Cordierite and Anorthite based recrystallizable glass was prepared through solid-state method. The powder was then characterised for its phase purity, microstructure and elemental compositions using XRD, FESEM and EDAX. The green tapes were characterised for its thickness, uniformity, green and sintered density, surface defects such as pinholes and cracks, adhesion and tensile strength. The dielectric properties as well as thermal properties are also evaluated. The results are reported.

Stabilized director buckling patterns in nematic elastomers and their dynamic optical effects

AbstractPearlescence and iridescence, which are a class of light diffusion effects that exhibit sharp viewing-angle-dependent brightness and colors, are important material properties for notification purposes and lighting devices. Here we report elastomeric materials with self-organized periodic birefringent patterns that exhibit these optical effects, with additional dynamic and reversible tunability. A stack of micron-thick layers, each of which has a nematic director tilted from the layer normal in a different direction, assembles a birefringence-pattern-based anisotropic diffuser in a nematic liquid-crystal elastomer. The periodic pattern is formed after buckling induced by the uniaxial thermal shrinkage, and the associated rotation of an initially uniform director state. The patterns can be stabilized by secondary crosslinking. Upon deformation or increasing the temperature, the light diffusion with viewing-angle-dependent colors reversibly fades owing to the diminishing of optical effects via strain-induced alignment or thermal randomization of birefringence, respectively. Such elastomers with tunable self-organized birefringence patterns can be used for reconfigurable optical elements and strain/temperature detection in the form of films, tapes, rods, and fibers.

Influence of consolidating process on the properties of composites from thermosetting carbon fiber reinforced tapes

AbstractCarbon fiber reinforced tapes are a feasible option to tailor material properties of composite structures and to reduce waste due to cut‐offs. But composite properties are not only influenced by the selected material, but also via the applied curing process. The aim of this experimental investigation is a comparison of the mechanical properties of thermosetting carbon fiber reinforced tapes, which are cured in different curing processes. In the composites industry the autoclave curing process is considered to be the highest quality process for handling preimpregnated semifinished‐products, so called prepregs. Alongside the autoclave process there are several alternative routes, named “out‐of‐autoclave”–processes, which can also be chosen for prepreg curing. One option is prepreg hot‐pressing, a process which is intended for large part quantities and easy process control. The development of fast curing thermosetting resin systems with the possibility of complete curing in the range of minutes introduced snap‐cure prepregs, recommended to be used solely in hot presses. For this reason this type of prepreg, in form of unidirectional tapes, was used for the following experiments. Two additional curing processes were investigated for process‐comparison, namely oven‐curing and in‐situ consolidation. The placement of the prepreg tapes for the laminate build‐up was done by an automated fiber placement unit followed by the curing processes as mentioned before. During the characterization of the material properties the general accepted statement of the excellent autoclave laminate quality could be confirmed. Strengths of around 930 MPa and even above were achieved with three‐point coupon bending tests for laminates cured in the autoclave. The fiber volume fraction was slightly above 58% and the laminate porosity was 0.5%. In comparison oven cured and hot pressed laminates strength values were lower at around 675–775 MPa. Hot pressed laminate porosity content was about 1.3% and the fiber volume fraction of these laminates was 52%. Oven cured laminates showed a higher porosity content above 4% and a fiber volume fraction of 51%. The new approach for prepreg curing, the in‐situ consolidation process provided fairly good results which were comparable to those of the oven cured laminates. In this process the unidirectional prepreg tape is directly cured at the surface of a heatable table during automated fiber placement without subsequent curing under a vacuum bag. The positive testing outcome of in‐situ consolidated laminates shows a big potential for future research and development of this process.

Complications of the suburethral sling in the form of Mini Vaginal Tape (MVT): A case report.

Synthetic sub-urethral sling has become the most widely used technique for the surgical management of stress urinary incontinence. Despite a higher success rate, complications like migration, encrustation, and stone formation have been reported by a mid-urethral sling (MUS). Among mid-urethral sling procedures, mini vaginal tape (MVT) is very popular. As periurethral stone formation and urethrovaginal fistula are very uncommon after MVT, case report on this issue is sparse. The current case report features a 55-year female presented with lower abdominal pain and continuous urinary incontinence, 10 years after the MVT. She was diagnosed as a case of periurethral stone with urinary incontinence due to urethro-vaginal fistula. Our surgical team successfully removed the stone formed by the encrustation of the displaced tape and repaired the fistula. Following the MVT, a high degree of suspicion and long-term follow-up is mandatory for the diagnosis and management of these rare complications.

Testing and numerical investigations of hybrid composite for flight control surfaces in manufacturing variability contest

The design and certification of composite structures is based on the building block approach (BBA), following a bottom-up procedure. Starting from the bottom level of Rouchon’s pyramid of test, thousands of coupons need to be produced to determine design allowables and capture manufacturing, geometrical and microstructure variability values. The numerical approach provides desirable data to be confirmed by a reduced testing campaign, especially for the preliminary design process stages and material selection.In this paper a carbon fibers reinforced composite with epoxide resin used for aerospace application has been analyzed, in form of both fabric and unidirectional tape to validate the numerical model considering Salver (of MA Group company) manufacturing process variability data. Hybrid laminates composed of unidirectional plies and woven fabric layers have been tested to pursue a tailored approach based on design guidelines and stress requirements for aircraft flight control surfaces. Benchmarking the experimental-numerical test results allows to assess the statistical reliability of the proposed method.