Sticking Problems Research Articles

Moisture Determination of Static and In-Motion Powdered Infant Formula Utilising Multiprobe near Infrared Spectroscopy

Moisture content of powdered infant formula is a critical factor governing product quality, especially in terms of its physicochemical stability. High levels of moisture accelerate the conversion of amorphous lactose to α-lactose monohydrate, which is the main cause of sticking and caking problems. Conversely, milk powders may become more susceptible to lipid oxidation at relatively low moisture levels. Traditionally, moisture content has commonly been determined by methods based on the loss of weight when drying under controlled conditions in an oven. However, these methods are time consuming and not suitable for in-line measurement. Near infrared (NIR) spectroscopy is a rapid method and perhaps the most used and accepted alternative technique for the measurement of moisture content in the dairy industry. Significant challenges in using NIR spectroscopy in the manufacturing process are in-line measurement and real-time monitoring. In this work, a novel multiprobe NIR system based on a Fabry–Perot interferometer combined with four fibre probes was assessed for predicting the moisture content of samples with varying moisture levels (ranging from ca 2% to 13%) and recorded under static conditions and various levels of motion. Partial least squares (PLS) regression was used to correlate the spectral response to the reference moisture values. The coefficient of determination of calibration ( R2) and root mean square error of cross validation for the best model were 0.99% and 0.57%, respectively. The PLS calibration model was then applied to an independent set of samples recorded under both conditions: static [root mean square error of prediction ( RMSEP) = 0.62%] and motion at 0.01 m s−1 ( RMSEP = 0.66%), 0.07 m s−1 (1.07%) and 0.16 m s−1 (0.97%). Therefore, moisture predictions for both measuring modes agreed well with the reference values, even when samples were travelling at speeds of 0.16 m s−1. These results demonstrated that the approach is suitable for in-line moisture analysis of powdered infant formula.

Recent progress in low temperature nanoimprint lithography

Nanoimprint lithography is a low cost and high throughput technology to fabricate nanostructures with excellent resolution. However, traditional thermal nanoimprint limits its application field because high temperature induces many problems. Low temperature nanoimprint lithography, including ultraviolet nanoimprint lithography and room temperature nanoimprint lithography, can reduce or remove thermal cycle, overcome the sticking problem, alleviate the alignment errors due to different coefficients of thermal expansion and pattern polymer based materials that are intolerant to high temperature. Recent development of these three low temperature NIL techniques was discussed from the aspects of new resist, stamp, process and application. Low temperature nanoimprint has wide application in the fields of optoelectronics, displays and bio-applications.

A PDMS membrane microvalve with one-dimensional line valve seat for robust microfluidics

We have developed a monolithic polydimethylsiloxane (PDMS) membrane microvalve with an isotropically etched valve seat for robust microfluidics. In order to avoid bonding or sticking of the PDMS membrane to the valve seat during the bonding process, the valve seat was wet-etched to be a one-dimensional line instead of a plane. The simple wet-etching technique allowed for the fabrication of an anti-bonding architecture in a scalable manner, and it intrinsically prevented contact between the PDMS membrane and valve seat when no external force was applied (i.e., normally open). This approach enables the permanent device assembly so that the microfluidic chip can be operable in a wide range of fluid pressures (e.g., over 200 kPa) without any leakage and sticking problems.

Study on Continuing Airworthiness of Reciprocating Aeroengine about Valve Sticking and Valve Breakage

Recently, a certain type of aviation reciprocating engine encountered some valve sticking and valve breakage problems in succession because of lead built-up and bad compression performance of cylinders in China, which has serious impact on the safety and continuing airworthiness of this reciprocating engine and equipped aircraft. This article has undertaken an in-depth study on this valve sticking and breakage issue, analysis has been done on Chinese aviation gasoline chemical ingredient as well as differences of avgas between China and America. Binding the characteristics of this aero-engine, compression test and borescope inspection have been done on the affected cylinders, also an in-depth microscopic analysis on the deposit which has been accumulated on the cylinder, valve, spark plug and valve guide. Finally, solutions and recommendations are proposed to ensure the continuing safe operation of the engine and aircraft based on the analysis on obtained engine operation data. The reasons of valve sticking and valve breakage because of the lead built-up issue of reciprocation engine are not only the Tetraethyl lead content in Chinese avgas, but also engine operation conditions and levels of maintenances on engine.

Tablet formulation of an active pharmaceutical ingredient with a sticking and filming problem: direct compression and dry granulation evaluations

Objective: To develop a tablet formulation for an active pharmaceutical ingredient for which sticking and filming problems occurred during tablet punching.Methods: Direct compression and dry granulation tableting techniques were evaluated using factorial experimental design. The effects of chrome-coated punch tips, filler types and active percent in the tablet formulation by direct compression were evaluated. Similarly, for dry granulation using the roller compaction technique, three formulation factors – roller compaction pressure, intragranular filler percent and filler type – were studied. Tablets prepared by both techniques were characterized in regard to their compressibility index, tablet hardness, disintegration time, friability index and stickiness-filming index (an arbitrary index). Ten formulations were prepared by each technique. Using multiple response optimizations and estimated response surface plots, the data were analyzed to identify optimum levels for the formulation factors.Results: Compressibility index values for all the formulations prepared by direct compression exceeded 25%, unlike the blends prepared by dry granulation. Both tablet hardness and disintegration time for direct compression formulations were significantly lower than for dry granulation formulations. The friability index values were significantly higher for direct compression formulations than for dry granulation formulations. All the direct compression formulations, unlike the dry granulation formulations, had a high stickiness-filming index.Conclusion: Statistical analysis helped in identifying the optimum levels of formulation factors, as well as the method for eliminating sticking and filming. Unlike the direct compression technique, dry granulation yielded tablets for which sticking and filming were completely eliminated.

Influence of Intrinsic Solidification Behaviour on Quality of Stainless Steel Cast and Rolled Products

Recent advances in continuous casting have facilitated remarkable improvement in the quality of cast steel. The focus of the present paper is directed towards understanding of the influence of chemistry and intrinsic solidification behaviour on the different quality issues of stainless steel. An attempt has been made, wherever possible in quantitative terms , to correlate the chemistry and the process parameters with the quality factors. The relevant theoretical background has been touched upon. Understanding has been developed on the role of the ratio of nickel equivalent and chromium equivalent. This factor can be used to represent the chemistry of any stainless steel grade. Under similar casting conditions, specific problem of mould sticking , strand bulging , or depression formation has been explained invoking this chemistry factor. Each quality issue owes its genesis to interaction between the high-temperature strength and ductility of the solidifying shell during casting. The important roles of micro-segregation , the effective shell thickness during the early stage of casting , and the temperature range of transformation for δ-ferrite to austenite have been highlighted. An approach of grade-specific casting practice has been suggested to formulate the specific casting parameters. The developed understanding has been utilised to address specific quality problems in continuously cast slabs and rolled products of different stainless steel grades. This integrated understanding can be useful for ensuring the quality of stainless steel of any chemistry.

Research on Hydraulic Parameters and Field Tests of Horizontal Wells Sand-flushing with Rotating Jets

Horizontal wells sand-flushing by rotating jets is a new technology, which developed rapidly in recent years. By characters of high-pressure water jet and the technique of the damping rotation control, it can break up the consolidated sand bed easily and suspend the sand efficiently with the combination of high-pressure jet impact and strong annular helical flow. The technique can effectively solve the problem of sand sticking and pollution. It can fulfill the increasing production need of the horizontal well. This article studies the mechanism of sand-flushing with rotating jets and designs the optimization of hydraulic parameters, then forms the programming design software. The optimum displacement can clean out sand beds from the bottom and not cause new damage. Finally, field tests verify the feasibility for sand-flushing of horizontal wells with rotating jets.

44.1: Ameliorating the Sticking Phenomenon of the Photosensitive Alignment Layer by using Reactive Mesogen

AbstractIn this paper, we reported about photo‐alignment technology in neutralized the residual ion by using double side chain monomer for Fringe Field Switching (FFS) mode application. It could be improving on imaging sticking problem in alignment film which is photo‐reactive behavior include photo‐ degradation and cis‐trans conversion. According to the measurement results, the panel didn't change characteristics in driving voltage and pretilt angle etc., cause by doping low concentration.

Study on Cuttings Transport Efficiency Affected by Stabilizer's Blade Shape in Vertical Wells

Effective cuttings transport means a better hole cleaning in drilling operations, which can increase the rate of penetration (ROP), and avoids pipe sticking, higher drag and torque problems. This paper aimed to analyze cuttings transport efficiency affected by different blade shapes of stabilizers, which is often overlooked in drilling. For this purpose, Eulerian multiphase flow model was used to simulate the influence of different blade types of stabilizers on cuttings transport efficiency under rotating coordinates. Numerical simulations indicate that straight blade stabilizer is obviously superior to helical blade for cuttings transport efficiency in vertical wells using the same hydraulic parameter and rotating speed. Field tests were conducted in some medium-deep wells of Daqing Oil Field, and the results showed that repeated fragmentation of cuttings, bit balling and pipe sticking problems were improved, and ROP was obviously raised.

Technology Focus: Drilling and Completion Fluids (November 2012)

Technology Focus It has been a busy year for me; I definitely played less golf. I was appointed as the deputy chief of commercialization in the University of Malaya Center of Innovation and Commercialization (UMCIC) about a year ago. My tenure has just been extended for another year. UMCIC is a special unit within the university that spurs and elevates innovation and commercialization of academic research activities and output. This is echoed in most innovation and commercialization seminars and workshops. Everyone is talking about “the valley of death” and the challenges of getting universities and industry to be on the same page. In a recent oil and gas workshop I attended, a participant highlighted the limited (or lack of) real field-scale trials in the area of nano-technology application. It is an open secret that many industrial players tend to play it safe. As they say, “If it is working, don’t fix it.” However, things have changed over the years. The increases in energy demand and limited resources have driven the industry players to explore novel technologies, one of which is exploration and production nanotechnology. A tremendous amount of money has been invested in research laboratory and field trials in this area. In this feature, I highlighted four interesting papers that cover theoretical and experimental approaches and real field tests related to nanotechnology. The selected papers primarily discuss the applications of nanotechnology, specifically in drilling fluid technology. Two of the selected papers discuss field tests. One of the papers presents interesting preliminary test results of nano-based drilling fluids. It describes the formulation and test results of several nano-based fluids. The last paper presents the industry’s first field trial of a reservoir nanoagent. Here, the first industrially proven reservoir nanoagent template has been introduced and demonstrated through a push/pull field trial in an observation well. Another thing I learned, from a commercialization workshop, was the importance of commercializing an innovation. Innovation without commercialization is like watching a major golf tournament on Sunday without Tiger Woods, Rory McIlroy, Phil Michelson, Sergio Garcia, Jim Furyk, Matt Kuchar, Nick Watney, Steve Stricker, Zack Johnson, Jason Dufner, or Lee Westwood making the cut. I hope you enjoy and benefit from the selected papers. Don’t forget to look at the other interesting papers on the recommended reading list. In addition, watch for other related papers in the OnePetro online library. Recommended additional reading at OnePetro: www.onepetro.org. IPTC 14952 An Experimental Investigation on Use of Nanoparticles as Fluid Loss Additives in a Surfactant/Polymer-Based Drilling Fluid by Jayanth T. Srivatsa, Texas Tech University, et al. SPE 140816 A Biodegradable Chelating Agent Designed To Be an Environmentally Friendly Filter-Cake Breaker by Natalia Collins, Halliburton, et al. SPE 145840 Mitigating Lost Circulation and Differential Sticking Problems Using Silicon Nanoparticles by Saket M. Javeri, Maharashtra Institute of Technology, et al. SPE 153729 Wellbore Stability in Unconventional Shale—The Design of a Nanoparticle Fluid by Meghan Riley, M-I SWACO, et al.

The surface layer of pharmaceutical compacts: The role of the punch surface and its impact on the mechanical properties of the compacts

During pharmaceutical compaction, the interaction between the punch and the powder determines the formation and the aspect of the surface of the compact. In industry, the properties of the punch surface, which play a key role in this interaction, are sometimes changed by fixing an intermediate layer onto the punch to prevent sticking problems. In this article, the case of a polymer insert layer was studied. Firstly, sugar spheres were compacted with and without the polymer insert fixed onto the punches. After compaction with uncovered punches, the surface particles, which had been subjected to high deformation, were flattened on one side. However, it was observed, using confocal X-ray microfluorescence, that this kind of deformation was limited to the surface and that the bulk particles, which underwent a more isotropic deformation, still exhibited an approximately round shape. Secondly, the influence of the surface structure on the mechanical properties of the compacts was studied. The indentation hardness and the tensile strength of compacts of microcrystalline cellulose (MCC) and anhydrous calcium phosphate (aCP) were studied. No differences were found for the compacts of MCC produced with the two kinds of punches, but the compacts of aCP obtained with uncovered punches presented a higher hardness and a higher tensile strength than those obtained with covered punches.

ПРОБЛЕМА НАЛИПАННЯ АКРИЛОВИХ СПіВПОЛіМЕРіВ НА ОБЛАДНАННЯ ПРИ ЗАКЛЮЧНОМУ ОБРОБЛЕННі ТКАНИН

At the decision of problem of sticking of acryl copolymers on an equipment came from the mechanism of ionization of carboxyl groups of polymer. Both the decline of degree of sticking of polymer and increase of stability of compositions for dressing was thus attained.

Nano-Enhanced Drilling Fluids: Pioneering Approach to Overcome Uncompromising Drilling Problems

The idea of pushing the limits of drilling oil and gas wells by improving drilling fluids for undemanding and cost efficient drilling operations by extracting advantage from the wonders of nanotechnology forms the basis of the work presented here. Foremost, in order to highlight the significance of reducing the size distribution of particles, new clay ATR which has a chain like structure and offers enormous surface area and increased reactivity was tested in different sizes that were chemically and mechanically milled. Bentonite which is a commonly used drilling fluid additive was also tested in different particle size distribution (PSD) and rheological properties were tested. Significant reduction in viscosity with small sized particles was recorded. The tested material called ATR throughout this paper is shown to offer better functionality than bentonite without the requirement of other expensive additives. Experiments were performed with different size distributions and compositions and drastic changes in rheological properties are observed. A detailed investigation of the shear thinning behavior was also carried out with ATR samples in order to confirm its functionality for eliminating the problem of mechanical and differential pipe sticking, while retaining suitable viscosity and density for avoidance of problems like lost circulation, poor hole cleaning and inappropriate operating hydrostatic pressures.

A 500 MHz-to-1.2 GHz Reset Free Delay Locked Loop for Memory Controller with Hysteresis Coarse Lock Detector

This paper describes a reset-free delaylocked loop (DLL) for a memory controller application, with the aid of a hysteresis coarse lock detector. The coarse lock loop in the proposed DLL adjusts the delay between input and output clock within the pull-in range of the main loop phase detector. In addition, it monitors the main loop’s lock status by dividing the input clock and counting its multiphase edges. Moreover, by using hysteresis, it controls the coarse lock range, thus reduces jitter. The proposed DLL neither suffers from harmonic lock and stuck problems nor needs an external reset or start-up signal. In a 0.13-㎛ CMOS process, postlayout simulation demonstrates that, even with a switching supply noise, the peak-to-peak jitter is less than 30 ps over the operating range of 500-1200 ㎒. It occupies 0.04 ㎟ and dissipates 16.6 ㎽ at 1.2 ㎓.

Anti-Sticking Effects of Cr-N and Zr-DLC Films on Microinjection Molding for LGP Applications

Sticking problems in injection molds are a significant challenge in product quality control. Molds are usually coated with a surface ceramic layer to prevent sticking problems. This study presents two films deposited on light-guide plate microinjection molds using an unbalanced magnetron sputtering process to investigate the anti-sticking property of molds. The deposited film materials include chromium nitride (Cr-N) and zirconium containing diamond-like carbon (Zr-DLC). The anti-stick film properties examined here include water contact angles, the coefficients of friction, as well as product flatness for the practical injection process. The results show that the performance of Cr-N films involve water contact angles at 111.4 degrees and a coefficient of friction at 0.742, respectively. The performances of Zr-DLC films involve water contact angles at 86.2 degrees and a coefficient of friction at 0.106, respectively. For the practical injection process, the deposited Cr-N films have better anti-sticking property than do the deposited Zr-DLC films.

Development of Durable and High efficiency Thermal printhead

In recent years, applications with a thermal print system have been rapidly expanding to emerging countries. Under the circumstances, a lot of direct thermal paper is being developed locally by many companies leaving the end-users little to no choice but to use the local paper supplier.Unfortunately, some of this newly developed local direct thermal paper cause significant abrasions on the printheads forcing the users to replace the printheads frequently.Considering the situation, ROHM has developed a durable thermal printhead which can achieve three times longer life compared to conventional printheads, even with such severe locally manufactured medias. In addition, the new printhead has 15% improved energy-efficiency and contributes to the ability of accepting a low-sensitivity direct thermal paper.We have also developed AST (Anti Sticking Treatment) technology to prevent a sticking problem which causes a poor print-quality. The treatment also reduces paper residue build-up on the surface of printheads and keeps a good print-quality for continuous printing.

Contactless molding of arrayed chalcogenide glass lenses

The moldable chalcogenide glass material has been developed recently. This study developed a new process to produce an arrayed chalcogenide glass lenses by a contactless molding process, which is considered to have a great potential for the mass production of arrayed glass lenses with low cost, ease of manufacture and free of surface defects. The stainless steel plate with arrayed through holes was employed as the molds. The selenium based chalcogenide glass plate was put on the mold and nitrogen gas was introduced into the closed chamber to allow gas pressure up to 4 kg/cm 2. IR heating allows the chalcogenide glass plate to approach the soft point, and forces glass flows into the arrayed through holes to form the arrayed glass lenses by viscoelastic deformation. A higher forming temperature, pressure and longer time duration tend to produce the arrayed lenses with a higher peak height and a smaller radius of curvature. The arrayed chalcogenide glass lenses with a peak height of 430 μm can be obtained at a forming temperature of 305 °C, a gas pressure of 1 kg/cm 2 and a time duration of 110 s. The contactless gas assisted molding system can avoid contact induced glass sticking and gas bubble problems. The surface qualities of molded lenses are much better than that of lenses molded by the traditional contact molding process.

Design and fabrication of freestanding pitch-variable blazed gratings on a silicon-on-insulator wafer

This paper presents the design, fabrication and characterization of tunable blazed gratings by combining microactuators. A two-mask process is used to define a four-level blazed grating on silicon-on-insulator wafers, and high lateral resolution is achieved by fast atom beam etching. Electrostatic comb drive actuators with double-folded springs are proposed to translate the freestanding grating beams. In association with reactive ion etching and vapor HF release, the freestanding grating beams and the actuator structures are obtained on a 10 µm thick silicon device layer; the vapor HF release is used to remove the buried oxide layer, successfully relieving the residual stress and preventing sticking problems. The changes in the grating period are tested by applying the voltage to the microactuators and the optical experiments are carried out to characterize the diffraction properties of the fabricated grating. These experimental results show good agreement with theoretical prediction.

Modeling hysteresis in piezoelectric actuators using NARMAX models

This paper presents a non-linear moving average model with exogenous inputs (NMAX) and a non-linear auto-regressive moving average model with exogenous inputs (NARMAX) respectively to model static and dynamic hysteresis inherent in piezoelectric actuators. The modeling approach is based on the expanded input space that transforms the multi-valued mapping of hysteresis into a one-to-one mapping. In the expanded input space, a simple hysteretic operator is proposed to be used as one of the coordinates to specify the moving feature of hysteresis. Both the modified Akaike's information criterion (MAIC) and the recursive least squares (RLS) algorithm are employed to estimate the appropriate orders and coefficients of the models. The advantage of the proposed approach is in the systematic design procedure which can on-line update the model parameters so as to accommodate to the change of operation environment compared with the classical Preisach model. Moreover, the obtained model is non-linear in variables but linear in parameters so that it can avoid the problem of sticking in local minima which the neural network based models usually have. The results of the experiments have shown that the proposed models can accurately describe static and dynamic behavior of hysteresis in piezoelectric actuators.

Non-desired transitions and sliding-mode control of a multi-DOF mechanical system with stick-slip oscillations

Systems with discontinuous elements exhibit a wide variety of complex phenomena which must be considered in the control design process. A dynamical sliding-mode control is used to avoid different bit sticking problems appearing in conventional vertical oilwell drillstrings. The aim of the control system is to drive the rotary velocities of drillstring components to specified values. A discontinuous lumped-parameter torsional model of four degrees of freedom is considered. This model is more generic than those so far reported in the literature. The closed-loop system dynamics have four discontinuity surfaces. One of these surfaces is introduced in order to accomplish the control goal despite variations of key drilling parameters, such as, the weight on the bit, the top-rotary velocity and friction characteristics. Self-excited bit stick-slip oscillations and sticking phenomena are avoided with the controller here proposed. Moreover, an alternative procedure to investigate the stick-slip motion is presented, it is based on the study of the stability characteristics of the different system equilibria and their relationships to different sliding motions.