Electric Tape Research Articles

Effects of liquid-fuel temperature on rotating-detonation-wave propagation

The utilization of liquid fuel will greatly expand the application scope of rotating detonation engines, and there are still great challenges to achieve high-performance liquid-fuel rotating detonation operation. In this paper, aviation kerosene was used as the liquid fuel to investigate the effects of fuel temperature on the propagation characteristics of rotating detonation waves in two combustor structures: annular and cavity. An electric heating tape was employed to heat the kerosene up to 390 K. The results demonstrate that increasing the temperature of kerosene enhances its atomization efficiency, leading to a marked enhancement in the peak pressure and propagation stability of detonation waves. Moreover, the duration required to establish a detonation wave is notably reduced, as low as 11.2 ms. Furthermore, the detonation wave velocity increases with fuel temperature, with significantly higher velocities observed in the cavity combustor structure compared to the annular combustor structure. In the cavity combustor, the detonation wave velocity can reach up to 74 % of the theoretical CJ value. The results verify the feasibility of improving the rotating-detonation performance via increasing liquid-fuel temperature, which can provide reference for the engineering application of rotating detonation.

Used Polyethylene Bags to form Electric Insulation Sheet and Tape: An Innovative Frugal Approach

Used Polyethylene Bags to form Electric Insulation Sheet and Tape: An Innovative Frugal Approach

Simple Contact Sensor for Material on Die in Sheet Hydroforming

A simple material contact sensor on the forming tool was devised for sheet hydroforming. The applicability was investigated for the shallow forming of aluminum alloy sheet. A flat bottom axisymmetric die or a conical one was used. An antistatic electric tape was used as contact sensor. It is flexible and attached to the die cavity in the radial direction. Electrical resistance of the tape between the center and the contact position of the material changes as the forming progresses. The change in voltage of the resistance part corresponding to the contact length was captured continuously. The strain at the center of the circular test piece was also continuously measured using a strain gage for large deformation. A short contact length was captured for the flat bottom die, since the test piece deforms into a dome shape, and the tip of the dome contacts to the center of the die cavity. On the other hand, the captured length was longer in the forming with the conical die. The repetitive separation and contact motion of the test piece to the die in impact forming due to the impulsive water pressure was successfully captured by the contact sensor. The accuracy was relatively coarse due to that the diameter of the die cavity was small. However, it was found that the simple contact sensor can be applied to evaluate the deformation behavior of the material. The measured maximum strain of the test piece was larger in impact forming, and the strain concentration occurred. This may be due to the negative strain rate sensitivity of the material.

Chosen Mechanical Properties of Electric Tape Fences

This research is focused on electric tape fencing, particularly of fast-moving animals, especially horses. The mechanical behavior of electric fences is of great importance. On the one hand, the fence should be durable enough, but, on the other hand, it should break if a livestock gets spooked and decides to run through to not cause harm to the animal. Main goal of this study is, therefore, to analyze mechanical properties of different electric tape fences during tensile stress and to propose suitable rheological model useful both for describing mechanical behavior and for predicting properties of electric tape fences. The mechanical behavior of electric fences was examined through two main experimental tests: (a) quasi-static tests to gain the full stress/strain responses of the electric tape in tension and (b) dynamic and stress–relaxation tests to characterize the electric tape fence viscoelasticity. It was found out that strength of electric tape fences is directly dependent on total cross-section area of monofilaments, whereas stiffness coefficients and plasticity limits were also studied. Based on the detailed findings from both types of tension tests, a rheological model of the electric fence was proposed. The results show that the model appropriately describes the experimentally obtained data.

Making the Invisible Audible: A Simple Sound-Emitting Water Level Meter.

Making the Invisible Audible: A Simple Sound-Emitting Water Level Meter.

AUTOMATED CALCULATIONS IN THE DEVELOPMENT OF ENERGY-EFFICIENT DESIGNS OF FURNACES FOR ALUMINUM SCRAP REMELTING

The analysis of operational thermal conditions of the furnaces for aluminum scrap remelting is given. It was established that it is necessary to choose refractory materials with aluminum oxide content more than 85 % and the thickness of the thermal insulation should ensure the temperature of the external surfaces not higher than 50 °C when designing the furnaces for lining. On the basis of relevant methods packages of application programs have been developed for design calculations of lining and thermal insulation considering thermal conductivity change of individual layers as a result of their complete or partial impregnation with molten aluminum; calculations of energy balances; the selection of external heating devices with electric or flame heating. The power of the external heat source, the amount of heat spent on heating the scrap to the melting temperature, melting and overheating the melt to the working temperature and heat loss have been taken into account in the energy balance. The heat balance equation is used for determination of the melting time for electrically heated furnaces or the power of burner devices at the desired melting time. In the design calculations, the necessary thicknesses of lining and heat-insulating materials are chosen for all elements of enclosure. With appropriate calculations in dialog mode, it is also possible to change materials and their thickness quickly in case of exceeding the allowable operating temperatures of these materials. Options of using electric tape or wire heaters made of nichrome or EI-626 steel were considered during external heating devices calculations. Flame heating can be implemented using gas burners or liquid fuel nozzles. Further variant calculations based on the developed methods and software made it possible to create a furnace design with a capacity of 600 kW with reduced energy and operating costs for the melting process. Bibl. 14, Fig. 1, Tab. 1.

Performance of Calcium Chloride- Ammonia Adsorption Refrigeration System

An experimental study on the performance of calcium chloride-ammonia adsorption system is described. A single bed water cooled condenser adsorption refrigerator prototype, which utilises calcium chloride-ammonia pair has been developed and tested in the laboratory. Experiments have been conducted for desorption temperatures of 100 °C with desorption time varying from 1 to 4 hours. An electric tape heater and a timer were used to perform the experiments. The adsorption temperature profile, adsorption rate and prototype performance have been analysed and discussed. The tested heating and desorption temperature of 100 °C and heating and desorption time of 1 to 4 hours was able to create a cooling effect of the cold chamber of the prototype of between -0.8 to 8.3 °C, which is adequate for vaccine storage requirement of 2 to 8 °C. The estimated Coefficient of Performance of the system ranges between 0.025 and 0. 076.

Virtual Fencing Is Comparable to Electric Tape Fencing for Cattle Behavior and Welfare.

Virtual fencing technology restricts animal movement via communicated signals without physical boundaries. Specifically, the eShepherd™ automated virtual fencing system operates via GPS technology and provides stimuli via a neckband device. An audio warning tone is emitted at the virtual boundary which is followed by an electrical pulse if the animal continues moving forward. Animal welfare is a priority consideration for the commercial implementation of virtual fencing systems. The current study assessed the effects of a virtual fence, in comparison to an electric tape fence, to contain eight groups of eight 12–14 month old steers within a 6-ha area across eight separate paddocks for 4 weeks following 1 week acclimation to the paddocks. Cattle were assessed across two cohorts (four groups/cohort) from January until March 2019 in Australia. Body weight and fecal samples from each animal were taken weekly. Fecal samples were processed for fecal cortisol metabolite (FCM) concentrations. IceQube R®'s fitted to the leg measured individual lying and standing time and the virtual fencing neckbands recorded GPS location and all administered audio and electrical stimuli. Cattle were maintained within their allocated area by both fence types across the 4-week period and those with the virtual fences were responding correctly to the audio cue with an average of 71.51 ± 2.26% of all cues across all animals being audio only. There was individual variation in rate of learning. The electric tape groups in cohort 1 showed a greater increase in body weight over 4 weeks than the virtual fence groups (P < 0.001) but this difference was not confirmed in cohort 2. The fence type statistically influenced the total daily lying time (P = 0.02) with less lying in cattle from the virtual fence groups but this difference equated to an average of <20 min per day. There were no differences between fence types in FCM concentrations (P = 0.39) and the concentrations decreased across time for all cattle (P < 0.001). These results indicate that virtual fencing technology effectively contains animals in a prescribed area across 4 weeks without substantial behavioral and welfare impacts on the cattle.

Ex-situ up-conversion of biomass pyrolysis bio-oil vapors using Pt/Al2O3 nanostructured catalyst synergistically heated with steel balls via induction

Radiofrequency-driven hydrodeoxygenation of sawdust pyrolysis vapor and the coking performance of the catalysts were investigated using Pt/Al2O3 commercial pellets mixed with steel balls inside an alumina tube. The radio-frequency induction heating of the catalyst bed was compared with a conventional method of heating using electric tape engulfing the catalyst bed reactor. Partial deoxygenation of the oil was successfully achieved in the catalytic upgrading of pyrolysis oil at 234°C, with the use of the induction heater. The molar O/C ratio of the oil decreased from 1.36 to 0.51. No deoxygenation of the oil was observed using the electric tape control under identical conditions as both carbon and oxygen appeared to be removed at approximately equal rates, with the carbon being deposited in the form of coke onto the catalyst instead of being recovered in the liquid.

Relationship between the earlywood-to-latewood transition and changes in levels of stored starch around the cambium in locally heated stems of the evergreen conifer Chamaecyparis pisifera

We observed the formation of latewood tracheids with narrow diameters and thick walls and the disappearance of stored starch around the cambium on the locally heated region of stems in evergreen conifer Chamaecyparis pisifera during winter cambial dormancy. Wood formation is controlled by cambial cell division, which determines the quantity and quality of wood. We investigated the factors that control cambial activity and the formation of new tracheids in locally heated stems of the evergreen conifer Chamaecyparis pisifera. Electric heating tape was wrapped around one side of the stem, at breast height, of two trees in 2013 and two in 2014. Pairs of stems were locally heated in winter, and small blocks were collected from heated and non-heated regions of stems. Cambial activity and levels of stored starch around the cambium were investigated by microscopy. Cambial reactivation and xylem differentiation occurred earlier in heated than in non-heated regions. New cell plates were formed after 14–18 days of heating. After a few layers of tracheids with large diameters and thin walls had formed, cell division and cell enlargement during differentiation were inhibited. Tracheids with narrow diameters and thick walls, defining those as latewood, were formed near the cambium, and finally, four to six layers of tracheids were induced. After cambial reactivation, amounts of stored starch started to decrease and starch disappeared completely from phloem and xylem cells that were located near the cambium during the differentiation of heated regions. Our results suggest that an increase in temperature induces the conversion of stored starch to soluble sugars for continuous cambial cell division and earlywood formation. By contrast, a shortage of stored starch might be responsible for inhibition of cambial activity and induction of the formation of latewood tracheids.

Changes in the localization and levels of starch and lipids in cambium and phloem during cambial reactivation by artificial heating of main stems of Cryptomeria japonica trees.

Cambial reactivation in trees occurs from late winter to early spring when photosynthesis is minimal or almost non-existent. Reserve materials might be important for wood formation in trees. The localization and approximate levels of starch and lipids (as droplets) and number of starch granules in cambium and phloem were examined from cambial dormancy to the start of xylem differentiation in locally heated stems of Cryptomeria japonica trees in winter. Electric heating tape was wrapped on one side of the stem of Cryptomeria japonica trees at breast height in winter. The localization and approximate levels of starch and lipids (as droplets) and number of starch granules were determined by image analysis of optical digital images obtained by confocal laser scanning microscopy. Localized heating induced earlier cambial reactivation and xylem differentiation in stems of Cryptomeria japonica, as compared with non-heated stems. There were clear changes in the respective localizations and levels of starch and lipids (as droplets) determined in terms of relative areas on images, from cambial dormancy to the start of xylem differentiation in heated stems. In heated stems, the levels and number of starch granules fell from cambial reactivation to the start of xylem differentiation. There was a significant decrease in the relative area occupied by lipid droplets in the cambium from cambial reactivation to the start of xylem differentiation in heated stems. The results showed clearly that the levels and number of storage starch granules in cambium and phloem cells and levels of lipids (as droplets) in the cambium decreased from cambial reactivation to the start of xylem differentiation in heated stems during the winter. The observations suggest that starch and lipid droplets might be needed as sources of energy for the initiation of cambial cell division and the differentiation of xylem in Cryptomeria japonica.

Trademarks of Faith: "Chabad and Chanukah in America"

Americans familiar with the Brooklyn-based Chabad Hasidic movement know the group primarily through its public Jewish ritual and outreach campaigns, from the ‘‘mitzvah tanks’’ in American cities, to its star-studded telethons and photo-ops with political leaders. Perhaps the group’s best known public campaign is the giant Chanukah menorah lightings it sponsors and the associated media coverage. While some of these lightings are geared towards local crowds, others are staged media events, televised live on public and cable channels, and more recently, streamed on Chabad-affiliated web sites. Starting in 1989, Chabad simultaneously linked international Chanukah menorah lightings with real-time reporting in their televised Chanukah Live spectaculars. Many ‘‘outside’’ photographers have documented Chabad’s Chanukah celebrations as tourists, and others, such as Mal Warshaw in the 1970s, Yaakov Agam in the 1980s, and Frederic Brenner in the 1990s turned to Chabad’s Chanukah events as artists. One of the photographs Brenner reproduced in large-scale format in his Diaspora: Homelands in Exile album (2003) and in a two-page foldout in the Jews/America/A Representation album (1996), is a black-andwhite panoramic shot of the interior of the Chabad World Headquarters during the 1993 Chanukah season (Figure 1). Entitled Chanukah Live!, this photograph records the spectacle of Chabad’s embrace of modern technology for the annual televised Chanukah extravaganza. Taken in the last months of Rabbi Menachem Mendel Schneerson’s life, the ‘‘Rebbe,’’ as his Hasidim reverentially call him, dominates an otherwise empty room through a refracted image on seven monitors in preparation for the Chanukah Live! broadcast in December of 1993. Loudspeakers, hanging cables, electric tape, exposed air conditioner ducts, vents, and still fans riddle the ceiling and hasty banners advertise the upcoming holiday media event on the

A proposal of a new display method for the tactile voice coder: Usage of the swept convex pattern

A fingertip tactile vocoder for the deaf, has been designed, which has a vibrator matrix with 4×16 pins. A sweeping display method was proposed so that the stimuli were moved from right to left on a fingertip surface like electric news tape. From the experimental results, it was proven that an identification rate of the seven Japanese monosyllabic voices increased and reached 55% at a sweep speed of 10 cm/s. Furthermore, in order to improve identification rate, the usage of the convex pattern like Braille has been proposed, in addition to the sweeping display method. It was found that the identification rate of the seven Japanese monosyllabic voices increased by combining the convex pattern with the vibratory pattern, and the increment was about 20%, even though training period was 30 min. From the above results, it was concluded that the usage of the swept convex pattern besides the swept vibratory pattern was effective to increase the identification rate of speech. [Work supported by the Ministry of Education, Science and Culture, Grant-in-Aid for Scientific Research (A)(2) No. 06402067.]

Equipment

Hotfoil Ltd of Wombourne, Wolverhampton, have developed an extruded electric heating tape called the ‘Type GP.’ The heating tape is woven glass insulated plastic sheathed and it can be operated for temperatures up to 50°C.

Very thin electric tape with high initial and maximum magnetic permeability

Very thin electric tape with high initial and maximum magnetic permeability

An automatic sample changer for α-, ß- and γ- active sources

A sample changer with a turntable that accommodates twelve uncovered, solid sources for α- or soft ß-particle counting in a windowless gas-flow counter is described. The turntable movement was designed to position the sources accurately beneath the counter. A pneumatic jack unit raises the source and seals it to the counter so that entrapped air can be displaced by the counting gas during a flushing period that precedes the counting period. A second position is provided for a detector of a different type, an end-window ß-particle counter or a NaI(Tl) crystal, for example. An absorption curve can be obtained automatically with an end-window counter by placing the source on a shelf below the turntable and absorbers in the turntable. Sources can be counted for a selected time or until a selected number of counts accumulates, whichever occurs first. Timing is done by a tuning fork oscillator. The turntable position number, accumulated count, duration of count period and elapsed time from an arbitrary zero are recorded at the end of each count cycle by an electric typewriter and/or tape punch.

Rubber Resins: Some Properties and Possibilities of Use

Abstract However, their present uses and possible future uses deserve consideration. Their tendency to thicken in certain solvents has been applied to use in imparting false body (thickening) to certain varnishes. In such cases it is likely that the rubber resin is modified to reduce tackiness before compounding it into quick-drying spirit varnishes. As plasticizers for brittle resins and asphalts they afford a very inexpensive raw material. But, again, experiments must be performed to see if the rubber resin is compatible with the natural or synthetic one, as there is little information as to whether plasticizers form solid solutions or only mechanical mixtures with the resins after heating and mixing. In one case a large shoe manufacturer purchased many tons of gutta-percha resin for impregnation of threads used in sewing on soles; the object was to prevent the entrance of moisture into the shoe and to supply a flexible adhesive. Electric friction tape, which must have an eversoft tacky surface, is coated with a compound of a bitumen, regenerated rubber, and a gutta resin, and is similar in composition to readily appliable insulation pastes, which are used on underground electric cables. The use in ever-soft adhesives and in flypaper are only two of the minor ones. The application of these resins to textiles in the form of emulsions shows large possibilities, as they can be emulsified with ammonium oleate or linoleate and, on drying, leave behind films of rubber resin and the fat acid of the emulsifier. A hardened balata resin has been used in linoleum cement. The soft resin or even the oily one can be hardened by heating for four hours at 80° C, after adding 1 per cent of manganese resinate or 0.5 per cent of calcium carbonate. Treatment of the same resin with sulfur chloride results in a viscous resin which, when warm, can be pulled out into ropes like taffy candy and, when cold, is still viscous. In closing, the writer wishes to state that, even if a reader may fail to find here the exact information he desires about a certain rubber resin, let it be hoped that what information he does find will save many hours of fruitless toil.