Sticking Effect Research Articles

Comparative Research of the Sizing Performance of the Compact Spun-Yarn and Ring Spun-Yarn

The characteristics of the compact spun yarn were introduced, and the problems in the sizing process of compact spun yarns were analyzed. Because of the high size loading of the compact spun yarn, a large number of yarns break and the chubbiness of the fabric were affected. Aiming at the problems above, through sizing experiment and testing of the performance of the yarns, the differences between the compact spun yarn and the conventional ring spun yarn were analyzed. Comparing with the conventional ring spun yarn, the size loading rate of the compact spun yarn was reduced about 1 to 3.5 percentage points under the same equipment conditions and sizing techniques. To obtain the same strength and hairiness sticking effect, the size loading of the compact spun yarn can be 5 to 6 percentage points lower than that of the conventional ring spun yarn. Sizing materials can be saved, and the cost of the sizing process could reduced by 50%.

Dynamic analysis of planar multi-body systems with LuGre friction at differently located revolute clearance joints

In this paper, the dynamic response of a planar rigid multi-body system with stick–slip friction in revolute clearance joints is studied. LuGre friction law is proposed to model the stick–slip friction at the revolute clearance joints. This is because using this law, one can capture the variation of the friction force with slip velocity, thus making it suitable for studies involving stick–slip motions. The effective coefficient of friction is represented as a function of the relative tangential velocity of the contacting bodies, that is, the journal and the bearing, and an internal state. In LuGre friction model, the internal state is considered to be the average bristle deflection of the contacting bodies. By applying the LuGre friction law on a typical slider–crank mechanism, the friction force in the revolute joint having clearance is seen not to have a discontinuity at zero slip velocity throughout the simulation unlike in static friction models. In addition, LuGre model was observed to capture the Stribeck effect which is a phenomenon associated directly with stick–slip friction. The friction forces are seen to increase with increase in input speed. The effect of stick–slip friction on the overall dynamic behavior of a mechanical system at different speeds was seen to vary from one clearance joint to another.

Effects of stick–slip motions on Besocke-style scanners in scanning probe microscopes

In Besocke-style scanners, a theoretical model with stick–slip sliding boundary conditions is presented by Timoshenko beam theory combined with the harmonic-balance method. The flexural vibration characteristics of the piezo-tubes induced by the stick–slip motions of the ball on the rail are investigated. The results show that the flexural vibrations essentially depend on the ratio of the ball–rail lateral friction threshold to the product of the ball–rail lateral contact stiffness and the vibration amplitude of the ball. When the ratio changes from zero to one, the lateral friction applied to the ball induces complex flexural vibrations. The vibrations can be regulated by adjusting an input electric signal to change the vibration amplitude of the ball, or using an external electro-magnetic force to change the preload of the ball–rail interaction, or changing the radius of the ball. Thus, the adverse vibrations of Besocke-style scanner can be eliminated to improve the spatial resolution of the atomic structure in scanning probe microscopes.

Observation on the effect of auricular point sticking for vomiting induced by chemotherapy

Objective To explore the effect of auricular point sticking in relieving chemotherapy induced vomiting, and to observe its effect on the usage of Ondansetron hydrochlorid injection.

Fluorescence Correlation Spectroscopy in Semiadhesive Wall Proximity

With examination of diffusion in heterogeneous media through fluorescence correlation spectroscopy, the temporal correlation of the intensity signal shows a long correlation tail and the characteristic diffusion time results are no longer easy to determine. Excluded volume and sticking effects have been proposed to justify such deviations from the standard behavior since all contribute and lead to anomalous diffusion mechanisms . Usually, the anomalous coefficient embodies all the effects of environmental heterogeneity providing too general explanations for the exotic diffusion recorded. Here, we investigated whether the reason of anomalies could be related to a lack of an adequate interpretative model for heterogeneous systems and how the presence of obstacles on the detection volume length scale could affect fluorescence correlation spectroscopy experiments. We report an original modeling of the autocorrelation function where fluorophores experience reflection or adsorption at a wall placed at distances comparable with the detection volume size. We successfully discriminate between steric and adhesion effects through the analysis of long time correlations and evaluate the adhesion strength through the evaluation of probability of being adsorbed and persistence time at the wall on reference data. The proposed model can be readily adopted to gain a better understanding of intracellular and nanoconfined diffusion opening the way for a more rational analysis of the diffusion mechanism in heterogeneous systems and further developing biological and biomedical applications.

Source dependency of exospheric sodium on Mercury

Due to a large solar radiation effect, the sodium exosphere exhibits many interesting effects, including the formation of an extended corona and a tail-like structure. The current suite of observations allows us to study some physical properties of the sodium exosphere, such as the source rates and the interaction with the surface, both experimentally and theoretically. In order to quantify the complex variations in the sodium exosphere in more detail, we use an exospheric model with the Monte-Carlo method to examine the surface interactions of a sodium atom, including the surface thermal accommodation rate and the sticking coefficient. The source rates from different components, such as the photon stimulated desorption (PSD), the meteoroid impact vaporization (MIV), and the solar wind ion sputtering (IS), can be constrained by comparing our exospheric model calculations with the published observational data. The detected terminator to limb (TL) ratio on the disk and the tail production rate can be explained with no sticking effect and small thermal accommodation rates. We also examine the best fit of the MIV source evolution, through comparison with the disk-averaged emission. The resultant discrepancy between the observations and the model fit may reflect the surface variation in the sodium abundance. A comprehensive mapping of the surface geochemical composition of the surface by the MESSENGER and Bepi-Colombo missions should give us more information about the nature of this surface-bound exosphere.

Comparative study to assess the effect of chewing stick and toothbrush on oral hygiene, gingival health and pocket depth among patients attending dental outpatient clinic in Udaipur, India

Objective: The purposes of this study was to assess and compare the oral hygiene, gingival health and pocket depth among patients using miswak (Salvadora Persica L) and toothbrush. Method: A total of 528 subjects participated in this study (63.6% females and 36.4% males), ranging in age from 20 to 45 years (mean = 35.43 ± 12.83). After fulfilling the entry criteria participants were classified according to their oral hygiene habits as miswak users (group I), tooth brush and paste users (group II) or both miswak users and tooth brush and paste users (group III). All subjects were assessed using Simplified Oral Hygiene Index (OHI-S), gingival index, pocket depth and gingival recession. Result: There was no statistically significant difference of mean OHI-S scores between miswak (1.04±0.64), toothbrush (1.08± 0.71) and combined users (1.09±0.74). On the other hand, all the three groups differ significantly in relation to mean gingival index scores, miswak (0.95±0.63), toothbrush (1.20± 0.59) and combined users (1.44±0.71) (p= 0.000). Also, Group II (3.90±1.88) demonstrated a significantly higher mean pocket depth than Group I (3.31±2.12) (p=0.019). However, gingival recession was significantly higher in Group I (2.17±1.64) in comparison to Group II (1.37±1.35) and Group III (1.30±1.58) (P=0.000). Conclusion: This study demonstrated that, miswak (Salvadora Persica L) users exhibited good oral hygiene and gingival index score but they had higher gingival recession scores which may influence the periodontal health. Key words: Tooth brush; Miswak; Oral hygiene; Gingivitis; Periodontal pocket; gingival recession

Spreading of fluids on solids under pressure: Slip and stick effects

Spreading of different types of fluid on solids under an impressed force is an interesting problem. Here we study spreading of four fluids, having different hydrophilicity and viscosity on two substrates – glass and perspex, under an external force. The area of contact of fluid and solid is video-photographed and its increase with time is measured. The results for different external forces can be scaled onto a common curve. We try to explain the nature of this curve on the basis of existing theoretical treatment where either the no-slip condition is used or slip between fluid and substrate is introduced. We find that of the eight cases under study, in five cases quantitative agreement is obtained using a positive slip coefficient. The remaining three can be explained with a negative slip coefficient, equivalent to a sticking effect.

Haptic supplementation and postural control in the elderly: Review and perspectives for assistive technologies

The present review paper focuses on the potential beneficial effect of haptic supplementation on postural control in the elderly. In the first part, we analyse the effects of age-related alterations in sensory integration on postural stability, in relation with the current models of human upright stance and sensorimotor mechanisms of postural control. Then, we present existing biofeedback devices and the most influential studies on haptic supplementation provided by a fixed or a mobile “touch support” that have been shown to enhance postural stability. In particular, we detailed preliminary results of a research program currently in progress in our group to investigate the effect of functional haptic information provided by a mobile support on postural stability. We speculate about potential applications of these findings. Finally, we suggest that investigating the effects of a haptic stick could help to better understand how elderly people use a walking aid in a “light” manner as a mediator for sensory cues during locomotion. In addition, it could eventually lead to the conception of new walking aids for various populations.

Nanogeometry Matters: Unexpected Decrease of Capillary Adhesion Forces with Increasing Relative Humidity

The sticking effect between hydrophilic surfaces occurring at increasing relative humidity (RH) is an everyday phenomenon with uncountable implications. Here experimental evidence is presented for a counterintuitive monotonous decrease of the capillary adhesion forces between hydrophilic surfaces with increasing RH for the whole humidity range. It is shown that this unexpected result is related to the actual shape of the asperity at the nanometer scale: a model based on macroscopic thermodynamics predicts this decrease in the adhesion force for a sharp object ending in an almost flat nanometer-sized apex, in full agreement with experiments. This anomalous decrease is due to the fact that a significant growth of the liquid meniscus formed at the contact region with increasing humidity is hindered for this geometry. These results are relevant in the analysis of the dynamical behavior of nanomenisci. They could also have an outstanding value in technological applications, since the undesirable sticking effect between surfaces occurring at increasing RH could be avoided by controlling the shape of the surface asperities at the nanometric scale.

Random Catalyst Walking along Polymerized Poly(3-hexylthiophene) Chains in Kumada Catalyst-Transfer Polycondensation

A "walking" process of Ni catalysts during Kumada catalyst-transfer polycondensation along polymerizing poly(3-hexylthiophene), P3HT, chains was investigated. To simplify polymer end group identifications, a compound Br-C(6)H(4)-Ni(dppe)-Br was prepared and used as an externally addable initiator. Normally, aryl moieties present in initiators incorporate into the structure of the resulting P3HT as the starting groups. We demonstrate that due to the presence of the C-Br group located in the para-position to the Ni substituent of the initiator, two different polymeric products are formed. One of them is the "normal" product, that is, P3HT with a para-bromophenyl end group, whereas another one has the phenyl ring inside the P3HT chain. The content of the product with the internal phenyl ring increases with the increase of the polymerization degree. Control experiments demonstrated that no intermolecular catalyst transfer takes place in the conditions used. Such results suggest that catalytic Ni(0) species are able to walk along the polymerizing chain containing many tens of thienyl rings up to the opposite end and can initiate polymerization there. Numerical analysis of a random hopping model was undertaken, which revealed that a combination of a random catalyst walking along the chain and a "sticking effect" at the end groups is operative in Kumada catalyst-transfer polycondensation.

Photoalignment of nematic liquid crystal on polyamic‐acid‐based soluble polyimide with no side fragments

Abstract— The photoalignment of nematic LC on a layer of newly synthesized UV‐sensitive polyimide without side fragments is reported. The photoaligning polymer advantageously differs from other photoaligning materials because of its extremely low sticking effect and residual DC voltage. These parameters, as well as the UV and thermal stability of the alignment, are not worse than those of rubbed polyimides. At the same time, the new material possesses all the advantages of photoaligning polymers.

RFN effects optimise solenoid valves

Simrit has made progress in reducing the sticking effects in solenoid valves by using nano-scale materials.

Effect of wall slip on the shear flow of a polymer in a channel with a wavy bottom

The effect of stick and wall slip boundary conditions on the specific features of the shear flow of viscous polymers in a confined two-dimensional channel with a wavy bottom is studied. The distribution of flow-rate disturbances across the transverse cross section of the channel is calculated by the numerical simulation of the Navier-Stokes equation for an incompressible fluid at arbitrary amplitudes and an arbitrary wave number of the wall. The wall slip is modeled by the introduction of a thin layer of a low-viscosity fluid at the bottom face. Slippage leads to a marked enhancement of flow rate disturbances including inertial advection. The results agree with the known analytical solutions for the low-amplitude wall wave.

Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork

AbstractBACKGROUND: The aim of this study was to find natural spice and herb extracts with antibacterial and antioxidant capacities that could be potentially used as natural preservatives in raw pork.RESULTS: The inhibitory effects of cinnamon stick, oregano, clove, pomegranate peel and grape seed extracts on Listeria monocytogenes, Staphylococcus aureus and Salmonella enterica were evaluated in raw pork at room temperature (∼20 °C). The influences of these extracts on lipid oxidation in the meat were also investigated. The pH, colour parameters and TBARS (thiobarbituric acid‐reactive substances) values were tested periodically. The results showed that all five natural extracts, especially clove, were effective against the bacteria. During storage the colour parameters of the extract‐treated pork samples changed slightly, in comparison with significant changes in the control. Treatments with these extracts increased the stability of raw pork against lipid oxidation. Clove was the most effective for retarding lipid oxidation and presented the highest antioxidant activity in raw pork.CONCLUSION: This study suggests that the tested extracts, especially clove, have potential as natural preservatives to reduce numbers of pathogenic bacteria, colour degradation and lipid oxidation in raw pork. Copyright © 2009 Society of Chemical Industry

Observation on effect of Anpu sticking combined with Iodoform internal drainage in treatment of patients with pressure sore of stage III and IV

Objective To explore the effect of combined therapy Anpu sticking with Iodoform internal drainage in treatment of patients with pressure sore of stage Ⅲ and Ⅳ. Methods 41 patients with Total bedsores 64 Ⅲ～Ⅳ period of pressure sore were divided into two groups : treatment group of 22 patients with 34 bedsores were combined therapy Anpu sticking with Iodoform internal drainage , the control group of 19 patients with 30 bedsores were treated with 0. 5 percent iodophorm. Results The total rate of effectiveness was 97.05 percent in the treatment group, 83. 33 percent in the control group. The effectiveness was higher in treatment group than that in controlled group and there were significantly differences between two groups (P<0.01) . Conclusion The effect of combined therapy Anpu sticking with Iodoform internal drainage in treatment of patients with pressure sore of stage Ⅲ and Ⅳ is better than 0. 5 percent iodophorm. Key words: Anpu sticking; Iodoform; Drainage; Combined therapy; Pressure sore

Micro continuum analysis of Wigner-Seitz model

There is a continuum contradiction between the Wigner-Seitz model and the volume infinitesimal. By analyzing the attractive force and the repulsive force of the bcc and fcc double Wigner-Seitz model with the classical Lennard-Jones potential, the conclusion that the relative error satisfies the engineering analysis is established even if double Wigner-Seitz models superpose. By comparing the single atom Al sphere-surface force of the Wigner-Seitz model with the discrete simulation, a satisfactory result is obtained. Based on the Wigner-Seitz model, the dynamic equation of the digital micro-mirror device （DMD）, including the sticking effect, is found. The DMD simulation result is compared with the measurement result. The conclusion that the Wigner-Seitz model satisfies the micro-continuum requirement of the micro- and nano-engineering is arrivedat.

Openness, Managerial Incentives and Heterogeneous Firms

Motivated by new evidence that managerial incentives play an important role in determining firm productivity, this paper incorporates the principal-agent mechanism into the new heterogeneous firm trade framework to examine the link between openness and endogenous firm productivity. We show that firm heterogeneity plays a crucial role in the effects of openness on firms' optimal incentive contracts via the trade-induced carrot and stick effect. This mechanism increases the marginal value of managerial effort, which motivates the firm owners (principals) to offer a higher power contract to the managers (agents) to reduce managerial slacks. The intra-firm managerial incentive mechanism stressed in this paper could be viewed as complementary to the inter-firm reallocation effect in the Melitz (2003) model in explaining the observed link between openness and aggregate productivity.

P‐254: Late‐News Poster: Investigation into Stability of Liquid Crystal Alignment with Newly Developed Polyimide Based Photopolymer

AbstractWe investigated the UV and thermal stability of newly developed PI based photopolymer. Image sticking effects of the test cell fabricated by the photoalignment method is compared to that by the rubbing method. Not only the UV and thermal stability, but also the image sticking effect is equivalent to those of the test cell fabricated by the rubbing method. We also demonstrate IPS cell fabricated by the photoalignment method with our material.

P‐129: Rejuvenated Photoalignment of Liquid Crystal on Cinnamoil‐Containing Polymers

AbstractWe report on easy orientation axis alternation in new photoaligning polymers (PG materials) based on cellulose backbone containing photosensitive cinnamoil groups. Materials have strong application potential due to high aligning quality and photosensitivity, strong anchoring energy, small sticking effect. Rejuvenation of polymer after UV‐irradiation makes PG attractive for various applications.