Compact Cylinder Research Articles

Hydrothermal solidification of siliceous and calcareous wastes into building materials: A generic mix design framework

The presence of inactive components in siliceous and calcareous wastes tends to cause a misunderstanding in their mix design for hydrothermal solidification. The contents of typical reactive elements (i.e. Caact, Siact and Alact) in raw materials are quickly determined by simulating hydrothermal conditions. A generic mix design framework is proposed, which utilizes the molar ratio of Caact/Siact as the controlling parameter. The framework was demonstrated through a series of studies, which involved the production of granular materials using a mixture of clayey soil with slaked lime, as well as the production of compacted cylinders using a mixture of clayey soil with either slaked lime or calcium carbide slag. Experimental results showed that the hydrothermal samples achieved their maximum strength when the molar ratio of Caact/Siact in raw materials approached the theoretical Ca/Si molar ratio (i.e. 0.83) in tobermorite, provided that the molar ratio of Alact/(Alact + Siact) remained below 21%.

A broadband Butler-based dual-polarized omni-directional antenna

AbstractThis paper presents a broadband Butler-based slant ±45° dual-polarized omni-directional antenna working at the frequency band of 1.69–2.69 GHz for extending wireless communication network capacity in the limited service size. The proposed antenna realizes a 360° full coverage with wider bandwidth in a compact cylinder and increases the network capacity to 6 × 6 MIMO instead of using three traditional 2 × 2 MIMO omni-directional antennas. Theoretical analysis, simulation, and fabrication are conducted to validate the idea of the proposed omni-directional antenna. The measured results show 46% bandwidth with 15 dB return loss, 2.2 dB azimuth null and 8.9–10.5 dBi gain for port-C with 0° phase increment, and 14.1 dB azimuth null and 9.6–10.6 dBi gain for port-L/R (left/right) with ±120° phase increment, respectively.

The Influence of a Rotary Compact Groove Cylinder on the Properties of Ring Spun Yarn

ABSTRACT Hairiness is a key index for yarn quality as it has a critically negative influence on weaving process. Yarns with less hairiness are highly demanded in textile industry. This work introduced an innovative way to mainly reduce the hairiness of ring spun yarns. Rotary compact groove cylinders (CGC) have been installed in the front of spinning nip to minimize the spinning triangle. Theoretical analysis has been carried out to reveal the mechanics of reducing hairiness. Two yarn types spun using conventional ring spinning and Siro spinning both with CGC device have also been compared to investigate this spinning method on the general application of different yarn types. Experimental results indicate that the CGC device can capture and control float fibers in the spinning triangle, pure cotton, and flax/cotton blend yarn were both improved with less hairiness (with reduction ratio of 3 mm hairs at 40% and 38%, respectively). The strength of CGC pure cotton yarn was improved, while the unevenness of CGC flax/cotton blend yarn were slightly deteriorated compared with original yarn. This method is easy to realize and requires no extra energy, which has great potential to be applied in the industrial production of ring spun yarns with better properties.

Chemo-rheological equivalence of bitumen between different lab ageing procedures: from binder to mixture

In an attempt to mimic the in-situ ageing of asphalt pavements, the exploration of appropriate laboratory ageing simulations has led to multiple standards on binder level. On asphalt mixture level, however, less consensus exists regarding ageing simulation protocols. This study aims to compare the chemo-rheological performance of bitumen between lab ageing protocols for binders, compacted and loose asphalt mixtures. A bituminous binder was used in bitumen ageing protocols, while it was also used to produce an AC10 mixture that was conditioned as a loose mixture and for compacted cylinders and slabs. Oven ageing of the mixtures was conducted for up to 9 days at 85 °C. The binder testing results, derived from empirical, rheological and chemical tests, indicate that 20 h of PAV ageing yields approximately similar results as 1–2 days of loose mixture oven ageing. Furthermore, in compacted samples, only the outer edge was influenced significantly by oxidative ageing.

A 3.7-kW Oscillating-Amplifying Integrated Fiber Laser Featuring a Compact Oval-Shaped Cylinder Package.

Combining the advantages of high efficiency, environmental robustness, and anti-reflection behavior, oscillating-amplifying integrated fiber lasers have become popular for use in high-power laser structures in industrial applications, wherein the size of the laser source matters. Here, an oscillating-amplifying integrated fiber laser in an oval-shaped cylinder package has been proposed and demonstrated, the footprint for which only occupies an area of 0.024 m2 apart from the pump diode, which is much smaller than in traditional planar fiber laser packages. Numerical simulations have been carried out, which have revealed that an oval-shaped cylinder package can effectively suppress the high-order mode in large mode area fiber setups and thereby benefit the integration of fusion points and the unpackaged elements at the same time. Over 3.7 kW of transverse mode instability (TMI)-free output power has been obtained, with a slope efficiency higher than 80%. With a custom-made chirped and tilted fiber Bragg grating (CTFBG), the Raman suppression ratio is improved to reach 38 dB at peak output power. The oval-shaped design has been verified to assist with the realization of TMI suppression and improve the integration of high-power fiber lasers. To the best of our knowledge, this fiber laser has among the smallest footprints of the various fiber sources at such high-power operating levels.

High-temperature mechanical behavior of compact carbon-bonded alumina based on a pitch-free lactose-tannin binder system

Compact cylinders and prismatic bars of carbon-bonded alumina based on an environment-friendly lactose-tannin binder system with lactose to tannin mass ratios of 5:1, 4:1 and 3:1, completely free of the conventional but harmful pitch binder, were prepared by slip casting and uniaxial pressing, respectively. The specimens were characterized by their physical properties (density, porosity), residual carbon content as well as microstructural analysis. In addition, the rheological behavior of the slurries was studied in order to prepare the compacts by slip casting. Mechanical tests at room temperature and, in particular, at high temperatures up to 1400 °C under bending, compression and creep loading, were performed. The results showed a brittle-to-ductile transition at temperatures between 1100 °C and 1300 °C. The bending strength of the bars was significantly lower compared to previously reported pitch-based ones. Early hardening of the powder before pressing could greatly decrease the bending strength. During heating at 1500 °C, cracks occurred unexpectedly on bars to be tested, and some dark grey droplets were observed as well after cooling down. A possible reason is a synergetic interaction between structural change of the carbonaceous matrix and overheating triggered by the electromagnetic field of the inductive heating.

Pharmacognostic Evaluation and Development of Quality Control Parameters for Root of Abelmoschus manihot (L.) Medik

Pharmacognosy Research,2023,15,1,101-111.DOI:10.5530/097484900263Published:December 2022Type:Original ArticleAuthors:Deshraj Shyamkant Chumbhale, and Mahendra Shivshankar Khyade Author(s) affiliations:Deshraj Shyamkant Chumbhale1, Mahendra Shivshankar Khyade2,* 1Department of Pharmacognosy, Amrutvahini College of Pharmacy, Sangamner, Ahmednagar, Maharashtra, INDIA. 2Department of Botany, Sangamner Nagarpalika Arts, D.J. Malpani Commerce and B.N. Sarda Science College (Autonomous), Sangamner, Maharashtra, INDIA. Abstract:Background: In traditional medicine, Abelmoschus manihot (L.) Medik, which belongs to the Malvaceae family, has been used to treat boils, sores, sprains, inflammations, tuberculosis, and leucoderma. Objectives: The objective of this study was to establish identification and quality control standards. Materials and Methods: For pharmacognostic evaluation, macroscopy, micromorphology and physicochemical constants have been used. Microchemical colour reaction tests and HPTLC studies were performed for qualitative phytochemistry. Results: Externally the root is yellowish-brown to yellowish-white and has a distinct odour, bitter taste, wavy shape, and smooth texture. The periderm was composed of 4-5 thin-walled cells. The secondary phloem has dilated rays and broad pyramid-shaped mucilage-packed rays. The fibres have thin walls and are narrow, and the secondary xylem is a compact circular cylinder with eight to eight radial lines of vessel chains. Prismatic calcium oxalate crystals, lignified long, narrow, thick-walled fibres with parenchyma cells, lignified cork cells, and cylindrical vessel elements were discovered in powdered samples. Physicochemically, the ash value was found above 8% which shows more than 75% solubility in acid whereas water and methanol extractive values were found to be just above and below 8% respectively. In UV-fluorescence study, very distinctive colour changes of the powdered root have been recorded. The phytochemical analysis reveals the presence of glycosides, saponins, flavonoids, tannins, and steroids. GC-MS and HPTLC are also used to characterize lipid and phenolic molecules. Conclusion: These findings will help in the future identification and quality control of A. manihot as reference standards. Keywords:Abelmoschus manihot, Pharmacognosy, Physicochemistry, PhytochemistryView:PDF (854.67 KB)

Low-frequency amplification of propeller tonal noise due to the scattering by a compact rigid cylinder

The present work addresses the scattering of the tonal noise of a low-speed propeller by a rigid cylinder, as a generic configuration representative of installed marine propellers. Both propeller and cylinder axes are parallel to each other. The diameters of the propeller and of the cylinder are much smaller than the acoustic wavelengths, as well as the propeller-cylinder distance. This corresponds to a compact regime of diffraction. Only the hydrodynamic tonal noise of the propeller at the first multiples of the blade-passing frequency is considered, assuming rigid blades, in a two-dimensional formulation. The direct and scattered sound fields are expressed in terms of spinning modes, with respect to the propeller and cylinder axes, respectively. Use is made of the exact Green’s function of the cylinder for the Helmholtz equation. The modes of orders ±1 are found the only efficient ones in the direct field, whereas higher-order modes rapidly decay. Yet, in the presence of the cylinder, higher-order modes are scattered into the contra-rotating mode of order 1 in the reference frame of the cylinder, with a strong amplification. A simple experiment, performed in air but with Helmholtz numbers typical of marine applications, confirms these results as key features of the asymptotic Green’s function of the cylinder. The same modal behavior is reproduced as closed-form simple expressions from a low-frequency approximation of the Green’s function. The results show that the installation effect is crucial for the tonal noise of marine propellers at very low frequencies.

A New Elastic Non Contacting Sealing Concept for Valves

The hydraulic binary counter concept was proposed as a means to realize compact and lightweight digital hydraulic cylinder drives for exoskeleton actuation. This counter principle is based on hydraulically actuated switching valves which have a hysteretic response with respect to the pilot pressure. Manufacturing tolerances of the tiny components caused unexpected high leakage which, in turn, led to a malfunction of the system.
 In this paper a new sealing concept, is introduced to solve this problem. It is based on a non-contact seal (sealing gap), which exploits a self-regulating, elasto-hydrodynamic effect to reduce a rather large initial gap h0 – to allow a rough tolerance – into a very small sealing gap h(x) to avoid dry friction of valve spool movement on the one hand but have very small leakage on the other hand.
 As sealing, an annular flexible ring made, e.g. of PTFE, is used which combines sufficient flexibility to allow this self adapting mechanism to a sufficient extent and to stay the high pressure loads.
 For the mathematical analysis of the concept, an approximate elasto-hydrodynamic analytical model is used. It sets the gap pressure, obtained from the Reynold’s equation for the sealing gap, the elastic restoring forces of the sealing ring, and the imparting pressure in equilibrium.
 The sealing concept is then simulated with a numerical model built with the finite element code ABAQUS, this results are compared with the one of the analytical model.
 It solves the Reynolds equation by a user defined subroutine. The simulation results indicate that this sealing principle delivers way better results than standard gap seals despite its rough manufacturing tolerances with one order of magnitude higher tolerance ranges. The application of this concept is not limited to small valves as needed for exoskeleton hydraulics but can be transferred to conventional type of hydraulics as well.

An exploratory numerical study of a diesel/methanol dual-fuel injector: Effects of nozzle number, nozzle diameter and spray spacial angle on a diesel/methanol dual-fuel direct injection engine

Methanol direct-injection makes it possible to the application of methanol at a high substitution ratio in diesel engines, but it is difficult to add a methanol injector to the already compact cylinder head. Therefore, an idea of a diesel/methanol dual-fuel injector is proposed, which can overcome both the inconvenience of arranging two injectors on the cylinder head and the disadvantage that the two injectors cannot be located in the center of the piston pit simultaneously. A three-dimensional simulation model coupled with chemical reaction kinetics is used to explore the effect of dual-fuel injector parameters including nozzle number and diesel/methanol spray spatial angle (β) on a diesel/methanol dual-fuel direct injection engine. The results show that more nozzles and smaller nozzle diameter contribute to fuel economy as well as the reduction of soot, THC, CO, and CH2O emissions, but higher ringing intensity (RI) and NOx emissions. It is found that 8 nozzles are the most suitable after weighing fuel economy, RI, and emissions. Secondly, influenced by the in-cylinder airflow, there exists an optimal spray spatial angle (β = 10°) to obtain the best fuel economy and emissions.

Manufacture of carbon-bonded alumina based on a lactose-tannin binder system via slip casting

Binders play an important role in the manufacture of carbon-bonded alumina (Al2O3-C) refractory materials. To diminish the currently used coal tar pitch binder Carbores® P, which could release hazardous polycyclic aromatic hydrocarbons during operations, environmental-friendly lactose and tannin are applied as the main binders in this study. Compact cylinders of fine-grained Al2O3-C based on the lactose-tannin (16 wt%) binder system with significantly reduced pitch content (4 wt%) are successfully prepared via slip casting for the first time. The lactose to tannin mass ratio is systematically varied from 5:1 to 1:5 in the raw material formulation. The specimens based on the new binder system are less dense, more porous and contain less residual carbon than the pitch-based reference. Mechanical tests show that the specimens with lactose-tannin ratio of 5:1, 4:1 and 3:1 have considerable cold crushing strengths, although the splitting tensile strengths are low. In contrast to the well-established pressing route, the slip casting route for compact Al2O3-C is more comparable to the replica route for Al2O3-C foam filter due to the pressureless shaping process.

Application of recyclable nano zero-valent iron encapsulated L-cysteine catalytic cylinder product for degradation of BTEX in groundwater by persulfate oxidation

Abstract Benzene, toluene, ethylbenzene and xylene (BTEX) possess a negative impact on the environment and human beings due to their highly toxic and carcinogenic properties. In this study, persulfate (PS) activated by nano zero-valent iron (nZVI) coupled with chelated L-cysteine (L-cys) process was investigated for BTEX degradation in contaminated groundwater. BTEX degradation had a significant acceleration and improvement with the removal from 62.7 to 100% along with the increasing dosage of L-cys from 0.12 to 0.27 M in 24 h. Further, the compact nZVI catalytic cylinder and nZVI encapsulated L-cys catalytic cylinder were successfully manufactured by encapsulating nZVI, and nZVI and L-cys together with additives of cement, river sand, stearic acid (SA) and zeolite. The SEM image, XRD patterns and FTIR spectra showed that the manufactured catalytic cylinder had a porous structure and encapsulated nZVI and L-cys successfully. Six successive cycles of BTEX degradation were completed and the degradation rate decreased gradually in each cycle. The catalytic activity of nZVI encapsulated L-cys catalytic cylinder was superior to nZVI catalytic cylinder in each cycle. The electron paramagnetic resonance (EPR) results indicated that HO• was the dominant active species in the BTEX degradation process. Benzoic acid (BA) scavenge experiments showed that L-cys could increase the yield of HO• in the PS/nZVI system. The HO• yields of PS/nZVI encapsulated L-cys catalytic cylinder system were 3.2 to 4.8 fold higher than those of the PS/nZVI catalytic cylinder system. The possible mechanisms of PS activation by nZVI encapsulated L-cys catalytic cylinder were supposed. Homogeneous Fenton reaction and heterogeneous catalysis on the nZVI surface are two co-existence mechanisms in the PS/nZVI encapsulated L-cys catalytic cylinder system. The findings of this study provide new insights into the mechanism of nZVI encapsulated L-cys catalytic cylinder activating PS, showing its potential applications for the remediation of groundwater.

Effect of curing temperature on carbonation behavior of steel slag compacts

Steel slag is now being explored as a novel prefabricated building material with high mechanical property and capability of carbon dioxide (CO2) storage when subjected to carbonation curing. Limited researches were focused on the effect of curing temperature on the carbonation performance of steel slag prefabricates. In this paper, the compacted steel slag cylinders were cured in the CO2 atmosphere of varied temperatures ranging from 0 °C to 90 °C. The evolutions of compressive strength and CO2 absorption ratio were tested. The changes of the surface temperature of the samples and the environmental temperature in the pressure tank during carbonation curing were recorded. The phase assemblage and microstructure of carbonated steel slag were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetry (TG) analysis. The results indicate that, in the early carbonation period, elevating the curing temperature is beneficial to the development of compressive strength and CO2 absorption ratio of the steel slag compacts. While, with the prolonging of curing time, the strength and CO2 absorption of samples cured at 0 °C and 90 °C is much lower than the samples cured at intermediate temperatures, i.e., 30 °C and 60 °C.

The study of Recoil Reducing Compact Air Pressure Device (CAPD)

Defense organization is one of the most reputed organization where best of the officers and soldiers serve for the safety on one’s country, without complaining about anything and giving their all in to protect us from various threats that could lead to disintegration of the country.Thus, the main motive to develop this device is to help our defense services to get the best, while they are giving their best for the country. The idea is to develop a device that would counter the recoil of the gun used by the officers and soldiers, to make them more efficient. Keeping in mind that the renewable resources of energy are depleting at a fast pace and pollution is increasing day by day leading to global warming, we have taken air as our resource to produce the desired effect. The device would be developed using aluminium, compact single cylinder air compressor and arduino programming to measure the pressure required for each shot fired from the gun. The principles of Law of conservation of momentum are applied to reduce the recoil of the gun to 80 %, thus helping in better aiming and precision. By installing this device, the demerits that makes AK47 a primitive gun would be subdued and without buying the expensive advanced guns, the arsenal would be upgraded at minimal cost possible.

Synthesis of pure (ligandless) titanium nanoparticles by EB-PVD method

Pure (ligandless) nanoparticles of titanium (4–20 nm) in a porous NaCl matrix (29–43 nm) were synthesized by the method of electron beam physical vapor deposition (EB-PVD). Independent electron beams were used to preheat the compacted cylinder from NaCl salt and Ti ingot up to formation of liquid melts. Evaporation of the initial materials from the melt surface, vapor flow mixing, and deposition of the mixed vapor on the surface of the water-cooled copper substrate took place in vacuum. Deposited condensate composition was regulated by the intensity of the vapor flows of evaporated materials. Results of studying the structure (SEM) and element composition of the condensate (EDS), phase composition (XPA), and the size of the nanoparticles (TEM) and crystallites (XPA + Scherrer equation), as well as their thermal stability in NaCl–Ti–O system (TGA), are given. It is shown that the dimensions and phase composition of titanium nanoparticles can be further controlled by heat treatment of the initial NaCl–Ti condensate, produced at low condensation temperatures. Investigations of the kinetics of oxidation of NaCl–Ti condensates in air (TGA) show that breaking of the vacuum in the chamber titanium nanoparticles in the porous NaCl matrix demonstrates high adsorption ability to moisture and oxygen from the air. With temperature increase up to 250–400 °C, practically all the moisture is removed, and further heating activates the process of titanium nanoparticle oxidation. Obtained results are considered from the viewpoint of physical and chemical adsorption.

Temperature and solvent facilitated extrusion based 3D printing for pharmaceuticals

On demand manufacturing of patient-specific oral doses provides significant advantages to patients and healthcare staff. Several 3D printing (3DP) technologies have been proposed as a potential digital alternative to conventional manufacturing of oral tablets. For an additive manufacturing approach to be successful for on-demand preparation, a facile process with minimal preparation steps and training requirements is needed. A novel hybrid approach to the 3D printing process is demonstrated here based on combining both a solvent and heating to facilitate extrusion. The system employed a moderate elevated temperature range (65-100 °C), a brief drying period, and a simple set-up. In this approach, a compact material cylinder is used as a pharmaceutical ink to be extruded in a temperature-controlled metal syringe. The process proved compatible with hygroscopic polymers [Poly(vinyl alcohol (PVA) and polyvinylpyrrolidone (PVP)] and a number of pharmaceutical fillers (lactose, sorbitol and D-mannitol). The fabricated tablets demonstrated acceptable compendial weight and content uniformity as well as mechanical resistance. In vitro drug release of theophylline from 3D printed tablets was dependent on the nature of the polymer and its molecular weight. This reported approach offers significant advantages compared to other 3DP technologies: simplification of pre-product, the use of a moderate temperature range, a minimal drying period, and avoiding the use of mechanically complicated machinery. In the future, we envisage the use of this low-cost and facile approach to fabricate small batches of bespoke tablets.

Separation of high velocity wet gas by phase-isolation and split-flow method

This paper proposes a new method for directly removing the liquid in wet gas from pipeline, especially for high velocity flow condition. The separation apparatus to be used is simply formed by enclosing a short section of the pipe with a compact cylinder and installing a swirler at the entrance. As gas–liquid mixture flows through the swirler downwardly, a strong swirl flow is created. Due to the centrifugal force, the two phases are isolated, forming a so-called swirling core-annular flow. Then a large portion of the gas core directly flows out of the separator, only the liquid film and a small portion of gas core (the conveying gas) enter the annular separation space through the upper portion of the ring-like window (RLW) in the pipe, where the conveying gas is separated from the liquid by centrifugal and gravitational forces and returns to the pipe through the lower part of the RLW. Numerical and experimental investigations were carried out in this study to determine the behavior of separation. The simulation and experimental results showed that the height of RLW has a strong effect on the behaviors of the separation, the conveying gas flowrate and the separation efficiency increase with the increase of RLW height, but the pressure drop also increases simultaneously. The separation efficiency even could approach 100% when the height of RLW is more than 1.5 pipe diameters with a 60% of conveying gas.

Co-based Superalloy (Stellite 6) Powder with Added Nanoparticles to be Molten by PTA

Nanotechnology is the domain of technological development and application of materials which go from 1 to 100 nm in at least one of their dimensions. The use of nanoparticles in engineering focuses on the development of new materials with special properties, which can be used as filler materials in the welding field. In this context, this study contributes to the stage preceding the deposition of the weld beads. This work aims to insert, using the colloidal processing technique, ceramic nanoparticles (ZrO2) into a Co-based superalloy (Stellite 6) and study the solidification of this “nanocomposite”. 4 filler materials in the shape of compacted cylinders were melted by PTA: Stellite 6 with added Fe carriers with ceramic nanoparticles (ZrO2) (1%, 2.5% and 7.5% volume) and Stellite 6 without any additions. The molten materials were characterized through optical and scanning electron microscopy with field emission (SEM-FEG), XRD and Vickers microhardness. The results show that the colloidal processing technique was effective in adhering the ZrO2 nanoparticles to the carrier Fe particles, which were mixed with Stellite 6, as well as the relationship between microstructure refinement, phases and microhardness after PTA melting.

Vessels Anastomosis Supporting Device for Coronary Artery Bypass Grafting

Coronary artery bypass grafting devices using integrated low-level energies adhesion has been developed. A prototype device was developed to establish device operating procedure for quick vascular adhesion and to indicate feasibility of anastomosis with the proposed mechanism. A cylinder part which has a nichrome winding is located at a tip of the prototype device to fix the position of a bypass graft on a coronary with vacuum and to give heat energy to the vessels. The sequence of the suction was suitably selected because the air flow due to suction deteriorated a heating capacity in the temperature measurement test. The prototype device successfully demonstrated the ability of vascular adhesion under blood flow environment. Then, an improved device with a compact cylinder and modified arms which has integrated heating and pressurizing mechanism was developed to easier access to the coronary and to prevent the heater from contacting to surrounding tissues was developed. An anastomosis success rate of the improved device is 83%. In addition, the improved device indicates sufficient tensile force which is 1.4 times higher than that of the prototype device and can withstand a blood pressure of 350 mmHg.

Ceramic Dust Based Binder for Sustainable Stabilisation of Low Flood-Plain Soil

The main objective of this study is to investigate the potential use of ceramic dust, by-products from manufacturing industry as a binder in the stabilisation of Laterite Soil. Laboratory investigation involving fabrication of soil cylinders of laterite soil stabilised with 100% CD and combination of CD with traditional binder Lime and PC at 50:50 ratio at 10%, 20% and 30% stabiliser dosage. The compacted cylinders were cured for 7, 28, 60 and 180 days prior for testing. The results from this study illustrated that all key parameters of compressive strength, durability and linear expansion were within the acceptable engineering standard of soil stabilisation. When using blended binders, it further enhances the engineering properties of stabilised material. From the environmental and sustainability, this cementitious technology anticipated that this new innovative stabiliser can be used in low flood-plain soil to mitigate the effect of flooding.