Reduction In Coefficient Research Articles

Application of Scirpus grossus fiber as a sound absorber

The application of Scirpus grossus (SG) fiber as a sound absorber is important to reduce the level of noise affected the physical and mental wellbeing of people. The sound absorption coefficient (SAC) and noise reduction coefficient (NRC) of the SG specimen were evaluated based on a typical model-based design using the data analysis with MATLAB. The results showed that SG specimen with a thickness of 20 mm coated with the perforated aluminum sheet (PAS) compared to that without coating can improve the capability of sound absorption by 14% at the frequency of 4000 Hz. SG specimen coated with PAS that has a NRC value of 0.39 can absorb 39% of sound and thus reflects 61% of sound wave while SG specimen without coating that has a NRC value of 0.23 absorbs 23% of sound and can reflect 77% of sound wave. The sound absorption class of D for SG specimen coated with PAS should be better that of E for SG specimen without coating, which permits us to get better understanding on the applications of SG fiber as a sound adsorber in the future.

Tribological performance of ficus carica oil modified with ethylene vinyl acetate and sodium dodecyl benzenesulfonate

PurposeDue to the environmental issues caused by petroleum lubricants used in lubrication, the concept of creating various bio-lubricants requires research globally. Thus, this study aims to develop, characterize and test the base ficus carica oil (fig oil) for its ethylene vinyl acetate copolymer (EVA) and sodium dodecylbenzene sulfonate (SDBS) content.Design/methodology/approachThe sample characterization was done using the Fourier transmission infrared spectrum, whereas the morphologies of the EVA, SDBS particles and lubricated surfaces were carried out under scanning electron microscope equipment. To ensure the homogeneity of the solution (base oil and additives), the formulations were subjected to the sonication process. The anti-friction and anti-wear properties of EVA and SDBS particles as lubricant additives were investigated using a ball on a flat high-frequency reciprocating rig tribo-tester.FindingsAccording to the findings, the base oil’s anti-friction and anti-wear capabilities can be greatly enhanced by the additions. revealed that the best results were obtained when 1.2% EVA + 2% SDBS was applied for the examination of wear (597.8 µm) and friction coefficient (0.106). Commercial references were used, nevertheless, and the results were excellent. This is because the particles in the contact area during lubrication have strong solubility and quickly penetrate the contact zone. The lubricating mechanisms were explained by a tribological model of the EVA + SDBS and SDBS particles.Research limitations/implicationsThe coefficient of friction and wear reduction caused by the use of the additives will certainly enhance system performance and protect the machine components from excessive wear that could cause damage or failure.Originality/valueThe originality and uniqueness of this work are officially affirmed by the authors. The authors’ autonomous and original contribution to the development of sustainable lubrication is represented in this work. To the best of the authors’ knowledge, no other study has been published or made publicly available that duplicates the precise scope and goals of our research, and this conclusion is based on a thorough literature assessment.

Forecasting the Problem of Excessive Oil Entrainment in a Desalter Using Spinning Drop Method.

Frequent desalter upsets in the refineries processing opportunity crude oils are often triggered by a rapid and uncontrollable buildup of the rag layer, a thick water-in-oil emulsion, at the oil-brine interface. This is caused by spontaneous emulsification of brine in oil. This study investigates a unique observation from a spinning drop (SD) tensiometer, revealing the low apparent interfacial tension and rigidity of SD caused by spontaneous emulsification. Fine droplets of brine generated through spontaneous emulsification decorate the SD surface and form a stable, low-energy bilayer. Simulated rag layers using the brines from upset incidences exhibit similar behavior, indicating that spontaneous emulsification is driven by chemical species in brine, which promote osmotic water transport. The rate of rag layer buildup correlates with the rate of spontaneous emulsification, with the temperature coefficient of interfacial tension reduction serving as a sensitive indicator. An imminent upset in the operation can be forecasted by measuring this temperature coefficient, enabling preventive measures.

Erosion mechanism of point bar retreat under the protection of a flexible mattress

Channel retreat can be responsible for the significant loss of banks, farmland, and wetlands, leading to drastic changes in fluvial sediment and local river regimes. Although current studies focus on the erosion process of natural river channels, the mechanism by which revetments, such as the flexible mattress, influence bank evolution is still unclear. Hence, by conducting a generalized model experiment, this study investigates the point bar failure process under the mattress protection, i.e., the episodic event when the soil reaches the static equilibrium state. Specifically, a scour hole develops at the junction between the soft and hard materials, causing mattress suspension on the bank toe’s side wall and resulting in a reduction coefficient for transverse scouring rate ranging from 0.08 to 0.15. Based on the theories of soil mechanics and river dynamics, the critical conditions for point bar instability were deduced, and a mechanical model describing its erosion process under the mattress protection was established. Furthermore, our model calculated the bank morphology and total erosion volume at different periods in the flume experiment, demonstrating a good agreement with the measured data. Additionally, variations in stability coefficient and forces exerted on soil (including shear strength, gravity, and fluid pressure) of the typical sections during point bar retreat were analyzed. Sensitivity analysis of the bank toe stability emphasized the controlling effect of soil mechanical properties and the negative feedback of mattress weight. The results reveal the interaction mechanism between the mattress protection and point bar failure, theoretically guiding the bank erosion strengthening and river management planning.

Adapting a phenomenological model for predicting acoustical behaviour of Camellia sinensis/Ananas comosus/E-glass fibre-blended epoxy hybrid composites

Developing a hybrid phenomenological model for predicting the sound absorption coefficient of a pineapple leaf fibre/waste tea leaf fibre/glass fibre/epoxy-based natural fibre-reinforced hybrid composites is the predominant topic of this article. Phenomenological models excel at extrapolating characteristic impedance and wave number whereas empirical models require fewer inputs but overlook wave propagation in pores. Existing models apply only to single-fibre-reinforced composites, necessitating the creation of a hybrid model for hybrid composites. The developed hybrid Zwikker–Kosten and Johnson–Champoux–Allard model shows good agreement with experimental data across the frequency range, with standard deviations of 0.001–0.029 and percent deviations of 1.11%–11.43%. The overall noise reduction coefficient between the model and experiments is 0.31 vs. 0.30, with a 3.33% deviation. Furthermore, the application of alkali treatment increased the surface roughness which in turn, enhanced the sound absorption capabilities of these composites. The increased fibre roughness also amplified friction between fibres and sound waves, resulting in higher sound absorption coefficients. In addition, X-ray diffraction, thermal stability (thermogravimetric analysis and differential scanning calorimetry), and scanning electron microscopy examinations were performed on the designated composition (5% by weight of pineapple leaf fibre and 25% by weight of waste tea leaf fibre) of the pineapple leaf fibre/waste tea leaf fibre/glass fibre/epoxy-based natural fibre-reinforced hybrid composite.

A controllable foaming approach for the fabrication of “rattan-like” graphene-based composite aerogel with desirable microwave absorption capacity

As a common environmental pollutant, microwave can cause great harms to human health. The development of high-performance microwave absorber with lightweight is indeed necessary. Herein, “rattan-like” graphene-based composite aerogels, having macroscopic pores surrounded by plenty of small pores, were designed and fabricated via an in-situ foaming then carbonized approach. Firstly, graphene oxide (GO), nanocellulose and ferrous ions were integrated into an aerogel with uniform large pores via a freeze-casting method. Then, the aerogel was immersed into a H2O2 solution, during which bubble clusters generated in situ. These bubbles were driven into the stacked GO sheets and formed small pores. With the increase of the H2O2 concentration from 0.5 to 10 wt%, the count percentage of the small pores in the aerogel increased from 81.5 to 95.2%. After the final carbonization, the graphene sheets were dually interconnected with magnetic nanoparticles and carbonized nanocellulose. The unique porous structure and dual-connected networks endowed the aerogel with enhanced conductive loss and optimized impedance matching capacity, and thus an excellent microwave absorption performance, whose maximum reflection loss achieves −68.5 dB. Further, the aerogel also exhibited superior sound absorption performance (noise reduction coefficient up to 0.91 in 1000–6300 Hz), and good mechanical stability.

Methodology for calculating load capacity reduction and slip relationship of clustered group nail connectors

Clustered group nail connectors are key connecting components for the full lifecycle construction and safe operation of steel–concrete composite structural bridges. To thoroughly investigate the stress mechanism of clustered group nail connectors in steel–concrete composite structures, this paper conducts a detailed numerical analysis on 100 sets of such connectors. It analyzes the stress mechanism of individual nail connectors and quantitatively calculates the group nail effect under the coupled action of multiple factors (nail spacing between layers, number of nail layers, concrete strength). Based on clarifying the force transmission patterns of nails and concrete in different layers during the loading process, this paper proposes a method for calculating the average bearing capacity reduction coefficient and the load-slip curve of single nails in clustered group nail connectors under the coupled action of multiple factors, which has been validated by experimental data. This research provides a theoretical basis for the design and calculation of group nail connectors in steel–concrete composite structural bridges.

Investigation on lubricity effectiveness Ficus carica lubricant modified with PTFE and TBHQ as additives for steel-steel contact application

The application of additives to the bio-lubricants is essential to improve the base oil tribological properties. A high-frequency reciprocating rig and different operating conditions were used to test the effects of tert-butylhydroquinone (TBHQ) and polytetrafluoroethylene (PTFE) polymer on the tribological performance of Ficus carica oil as a base oil for machine lubrication. The viscosity and Fourier transform infrared spectroscopy (FT-IR) evaluations were carried out to ascertain the additive's effectiveness. A scanning electron microscope was used to analyse the morphologies and the substrate-worn surfaces. When additives were applied separately, 1 wt% of PTFE produced a superior coefficient of friction (COF) and better wear reduction than other examined samples. In terms of wear resistance, commercial lubricant oil (CLO) SAE 5 W-30 performed better than the optimal 1 wt% PTFE + 0.3 wt% TBHQ blended with Ficus carica oil (FCO/L). At an increased frequency of 5 Hz, CLO outperformed FCO/L on COF and wear resistance. When examining the worn surfaces, less iron (Fe) was discovered on the FCO/L than the base Ficus carica oil, demonstrating the mending effect of the used additive as the underlying mechanism of wear reaction. The results show promising potential for the new formulation of a green lubricant since the tribological characteristics of Ficus carica oil were improved by the addition of the selected additives.

Enhancement mechanisms of self-lubricating Ti3SiC2 ceramic doping in CoCrFeNi high-entropy alloy via high-speed laser cladding: Tribology and electrochemical corrosion

High-entropy alloys (HEAs) are renowned for their superior mechanical properties and corrosion resistance, positioning them as promising materials in the realm of wear and corrosion-resistant applications. In this study, CoCrFeNi HEA coatings were fabricated utilizing the high-speed laser cladding (HLC), and the effects of adding Ti3SiC2 self-lubricating phase on the microstructure, wear resistance, and electrochemical corrosion performance of CoCrFeNi HEA coatings was investigated. The results show that CoCrFeNi HEA coatings synthesized via HLC exhibit an impressively low dilution rate of <0.1 %, while concurrently ensuring a robust metallurgical bond with the substrate. CoCrFeNi coating has an FCC simple solid solution structure. Upon the addition of Ti3SiC2, the composite structure comprises FCC, Ti3SiC2, and TiC phases. The friction coefficients (COFs) of CoCrFeNi coating and the coatings with 3, 6, and 9 at.% Ti3SiC2 content are 0.684, 0.628, 0.429, and 0.426, respectively. Predominantly, the wear mechanisms observed encompass abrasive wear, adhesive wear, and oxidative wear. Intriguingly, when the Ti3SiC2 content reaches 6 at.%, a contiguous self-lubricating layer forms within the wear track, leading to a notable reduction in COF and a marked enhancement in wear resistance. In electrochemical corrosion evaluations, the coatings demonstrated polarization resistances of 11,400, 9923, 9654, and 6125 Ω·cm2, respectively. While Ti3SiC2 exhibits commendable passivation capabilities, an elevated Ti3SiC2 content can expedite corrosion processes by fostering a potential difference battery formation on the coating surface.

3D Printed Nature Pattern Metastructure for The Sound Absorption Coefficient

This research investigates the influence of the shape of 3D printed metastructures on sound absorption performance, focusing on three distinct configurations inspired by nature: honeycomb, spiderweb, and gyroid. The objectives involve designing and producing sound-absorbing structures using the 3D printing Fused Deposition Modelling (FDM) method. Simultaneously, the study analyzes and compares their sound absorption performance by considering the sound absorption coefficient and the noise reduction coefficient (NRC) for each pore shape. Using computer-aided software, the three different pore shapes were designed and produced using Polylactic Acid (PLA) material through FDM 3D printing. Each design was replicated at three different thicknesses: 10mm, 20mm, and 30mm, all with a diameter of 94mm. The sound absorption coefficient of the samples was evaluated through impedance tube experiments, collecting data for alpha (α) from 250 Hz to 2000 Hz. Subsequently, NRC values were calculated for four different frequencies: 250Hz, 500Hz, 1000Hz, and 2000Hz, ensuring a comprehensive analysis. Results indicate that the gyroid structure exhibited the highest overall sound absorption coefficient across the tested frequency range, followed by the spider-web and honeycomb structures. Additionally, the 30mm thickness demonstrated greater sound-absorbing performance than the 20mm and 10mm thicknesses. These outcomes provide valuable insights into the sound absorption capabilities of 3D printed metastructures, highlighting the superior performance of the gyroid structure. Understanding the impact of pore shape and thickness on sound absorption performance contributes to the development of acoustically optimized materials for various applications

High-temperature axial tensile property and fire resisting performance of CFRP strand cable

High-temperature tensile tests and fire resisting performance tests were conducted on carbon fiber reinforced polymer (CFRP) strand cable, respectively, to identify axial tensile property deterioration of CFRP strand tendon (i.e., cable without initial tensile load) under 100–600℃ temperature range and determine fire resisting duration and ultimate temperature of CFRP strand cable with initial tensile load ratio from 0.2 to 0.8. High-temperature axial tensile property and fire resisting performance of different cables including CFRP and steel cables were compared to identify influence of non-uniform load distribution. The obtained results demonstrated that the dominate failure modes of specimen in both high-temperature tensile test and fire resisting performance test are tensile failure. Due to the degradation of mechanical property of resin matrix and bonding performance for resin matrix-fiber bundle interface exposed to elevated temperature, axial tensile strength of CFRP strand tendon degraded by 33.4% and 80.8% under 210℃ (glass transition temperature) and 600℃, respectively, compared to that under ambient temperature. Fire resisting duration of CFRP strand cables varied from 1.3 to 16.4 mins, indicating poor fire resisting performance. Reduction coefficient of bearing capacity for CFRP strand tendon decreased from 0.96 to 0.74 as temperature varied from 25 to 400℃, and then increased to 1.54 at 600℃. Compared to ribbed CFRP cable, CFRP strand cables with initial tensile load ratios ranging of 0.4 ∼ 0.8 (low ultimate temperatures) display worse fire resisting performance due to the prominent non-uniform load distribution among seven wires. Axial tensile strength and reduction coefficient of bearing capacity for CFRP strand tendon exposed to elevated temperature and fire resisting duration of CFRP strand cable and ribbed CFRP cable can be accurately predicted by the developed practical models.

Tradescantia Zebrina as New Creeping Plant for Good Sound Absorption Performance

The increasing need to address the environmental consequences of noise and visual pollution caused by infrastructure and industrial projects in residential regions has led to the implementation of regulations. These regulations aim to minimize such impacts and have resulted in a rising demand for acoustic barriers and visual screening solutions. Presently, green plants are being employed globally not only for creating a sustainable environment within green buildings but also for their sound absorption capabilities. The choice of plants suitable for green walls primarily focuses on tropical and annual species that demonstrate effortless growth capabilities. This research examines the capability of sound absorption of chosen creeping plants namely Tradescantia Zebrina (TZ) that potentially be used for green facades. The physical properties including morphology and acoustical properties by measuring the sound absorption coefficient (SAC) using two microphone impedance tubes. The plant with the noise reduction coefficient (NRC) was investigated further for the effect of the thickness of the plant on the sound absorption performance of a wall. The results showed 0.23, 0.35, and 0.52 NRC values respectively obtained from the different thicknesses of TZ There was an increment of sound absorption as the plants were attached to concrete brick as a green facade on its surface. On this basis, the capability to absorb sound by TZ as the green facade can be considered when designing the environmental structure.

Package-type strategies and packaging's carbon reduction decisions in the take-out industry

Using environmentally friendly packaging (E-packaging) instead of non-environmentally friendly packaging (N-packaging) can mitigate pollution and reduce carbon emissions. However, the market penetration rate of E-packaging is low, and the packaging carbon reduction level is uneven. This study uses game theory models to examine the factors affecting packaging carbon reduction levels and fees as well as firms' package-type decisions. First, we obtain the optimal solutions for packaging manufacturers and firms when they use different types of packaging under monopoly and competition, respectively. We find that green competition reduces the carbon reduction level of E-packaging, whereas price competition can increase it under certain conditions. The unit manufacturing cost of N-packaging and cost coefficient of carbon reduction are critical considerations for package-type decisions. When the unit manufacturing cost of N-packaging is low and the cost coefficient is large, no firm uses E-packaging. We also demonstrate that firms in a competitive market may become trapped in a prisoner's dilemma after making package-type decisions. Interestingly, we show that the firms' package-type decisions can hurt consumers and welfare under certain conditions, depending on the N-packaging's unit manufacturing cost and pollution damage factor. Our findings provide insights for packaging manufacturers, firms, and environmental regulatory agencies, and can help promote E-packaging.

Influence of corrosion on loading capacity of circular concrete-filled steel tubular column

Concrete-filled steel tubular (CFST) columns are commonly used in engineering, especially in load-bearing structures. This study conducts an in-depth examination of how the axial resistance of CFST columns varies with random corrosion. A finite element model for circular CFST columns is developed and its accuracy is verified using available experimental data. The interaction between the outer steel tube and the concrete column is explored, along with the introduction of a strength reduction coefficient concept. Additionally, the concept of an axial load-bearing capacity reduction coefficient is introduced to illustrate variations in the axial resistance of circular CFST columns during different corrosion stages. The degradation patterns of reduction coefficients for uniform and random corrosion depths in the steel tube and CFST columns with varying mass loss rates are analyzed, and formulas are provided to predict the axial resistance in different corrosion stages. Furthermore, the study investigates the influence of variables such as material strength, component dimensions, and the thickness of the external steel tube, resulting in adjustments to the original expressions for various conditions.

Study on Shear Slip Characteristics of Sandstone Plane Joints under Normal Dynamic Load Disturbance

Abstract Rock joints are susceptible to slip instability due to dynamic load disturbances such as blasting, earthquakes, and fracturation. A series of direct shear tests under the dynamic load were conducted on sandstone plane joints using the RDS-200xl. The work investigated the effects of normal static loads and normal dynamic-load frequencies and amplitudes on plane joints. Besides, the following items were proposed, that is, the peak-to-valley response rate, shear velocity vibration dominant frequency, shear-stress reduction coefficient, and discrete element numerical simulation method for plane-joint direct shear tests. The results were as follows: (1) The normal dynamic load frequency played a role in attenuating the shear stress amplitude with a threshold value of 0.5 Hz. (2) The shear velocity of the plane joint was completely controlled by the high normal dynamic load frequency. Their vibrational dominant frequencies were identical. (3) The amplitude of shear stress increased, and the median stress decreased with the increased normal dynamic load amplitude. The reduction-coefficient equation for sandstone plane joints was proposed to evaluate the shear stress under the normal dynamic load disturbance. (4) The shear-stress hysteresis phenomenon existed in the plane joints under the normal dynamic load, which required excessive shear displacements to reach peak shear strength. The peak shear displacement increased with the increased normal static load. Numerical simulations and indoor tests showed that high- and low-shear-velocity regions were the main reason for shear-stress hysteresis. The findings are conducive to revealing the shear destabilization mechanism of rock joints under dynamic load disturbance.

Structural characteristics properties of sugarcane bagasse and its sound absorption as composites

Noise pollution is one of the serious environmental pollutions. In recent years, the preparation of sound absorption composites using natural fibers as reinforcement material has attracted much attention. Sugarcane bagasse is a by-product of sugarcane. In order to improve the utilization rate of sugarcane bagasse, enrich and expand the application field of its renewable resources, sugarcane bagasse as a reinforcement material, and polycaprolactone as a matrix material are used to prepare sugarcane bagasse/polycaprolactone sound absorption composites by hot press molding technology to analyze the sound absorption performance. The sound absorption mechanism of the sugarcane bagasse sound absorption composites is revealed. First, the structural characteristics of sugarcane bagasse were characterized, and the relationship between its structure and sound absorption performance was analyzed. Second, the effects of sugarcane bagasse length, mass fraction, hot pressing pressure, hot pressing time, and hot pressing temperature on the sound absorption performance were investigated by one-factor analysis. The results show that when the length of sugarcane bagasse was 1.0 mm, the mass fraction was 35%, the hot pressing pressure was 12 MPa, the hot pressing time was 20 min, and the hot pressing temperature was 130°C, the average sound absorption coefficient was 0.38, the noise reduction coefficient was 0.31, and the maximal sound absorption coefficient was 0.80. This study provides an experimental and theoretical basis for the research and development of sound absorption composites made of sugarcane bagasse, and provides a new solution for the recycling of sugarcane bagasse.

ЗАВИСИМОСТЬ ТЕМПЕРАТУРЫ ПЕРЕДНЕЙ ПОВЕРХНОСТИ ТОКАРНОГО РЕЗЦА ОТ ЭВОЛЮЦИОННЫХ ИЗМЕНЕНИЙ ТРИБОДЕФОРМАЦИОННЫХ ПОКАЗАТЕЛЕЙ ПРОЦЕССА ОБРАБОТКИ

The study objective is modeling the temperature distribution on the surface of a heavily loaded tribocontact - front surface of a lathe tool - chips taking into account evolutionary changes in the cutting system.&#x0D; The task to which the paper is devoted is to assess the influence of evolutionary changes of tribodeformation parameters of the cutting process on the average and maximum temperature of the front surface of the lathe tool.&#x0D; Research methods. Contact temperatures are found out on the basis of mathematical modeling using data obtained during field experiments at longitudinal turning of 15X2NMFA steel blanks without cooling by T15K6 hard alloy plates. During resistance tests, the chip contact length with the front surface and the chip reduction coefficient used for calculation are determined, as well as the average temperature in the cutting zone, the value of which is used to assess the adequacy of the results obtained by digital modeling. &#x0D; The novelty of the work. Forecasting the temperature increase on the front surface of the cutter, taking into account the contribution of evolutionary changes in tribodeformation parameters of cutting.&#x0D; The results of the study. In the studied cutting system, according to the results of resistance tests, a decrease in the chip reduction coefficient is recorded over the processing time. The temperature distribution on the front surface of the cutter is modeled in two versions: taking into account the evolutionary adjustment of the chip reduction coefficient and related parameters – sliding velocity and thickness of the plastically deformed layer in the chip, and without taking into account their changes. It is found out that modeling adjusted for changes in tribological indicators allows to obtain calculated values of the temperature of the front surface closest to the experimentally recorded of average temperature in the cutting zone. &#x0D; Conclusions: Forecasting contact temperatures adjusted for evolutionary changes in tribodeformation parameters will allow to determine more accurately the moment in the evolution of the cutting system at which critical temperature values can be reached, and further processing is associated with the risk of critical wear or deterioration of the treated surface.

SELECTIVE LASER TRABECULOPLASTY AS A VALUEABLE MODALITY OF TREATMENT IN OPEN ANGLE GLAUCOMA PATIENT

Introduction &amp; ObjectivesSelective Laser Trabeculoplasty (SLT) has became an established treatment to lower intraocularpressure (IOP) for open angle glaucoma (OAG) and ocular hypertension. The aim of this study was toevaluate IOP lowering effect of SLT and correlate its laser parameter to the successful rate in OAG.&#x0D; MethodsThis is a prospective study of seventeen eyes OAG patients in Cicendo Eye Hospital from 1stNovember 2022 to 31th December 2022. SLT performed once in OAG with uncontrolled IOP (IOP &gt;21 mmHg). Outcome measured were IOP at post laser, 1week , 1 month, and 2 months of follow upafter SLT. Successful criteria determined as greater than 20% IOP reduction. Correlation betweensetting operational of SLT and primary outcome were measured. Student’s t-test (two-tailed,dependent) has been used to find the significance of study parameters.&#x0D; ResultsA total 17 eyes underwent SLT. Mean baseline IOP was 21,12 ? 4,0 mmHg. IOP was significantlydecreased from baseline post laser 18,06 ? 3,17 mmHg; at 1 week 17,06 ? 3,25 mmHg; 1 month15,53 ? 4,52 mmHg; and at 2 month follow up 15,47 ? 4,02 mmHg (p&lt;0,001). The successful rate ofSLT after two months follow up from this study were 76,5% samples (13 eyes). Mean of total laserenergy was 75,6 ? 16,8 mJ. There was correlation between total laser energy with percentage of 1month IOP reduction (coefficient : 0,470 (p&lt;0,029)).&#x0D; ConclusionSLT is effective and safe for reducing IOP in open angle glaucoma patient.

Experimental Research on Fatigue Behavior of Reinforced UHPC-NC Composite Beams under Cyclic Loading.

Ultra-high-performance concrete (UHPC), a new cement-based material that offers high mechanical strength and good durability, has been widely applied in construction and rehabilitation projects in recent years. An optimum bending system is achieved by positioning the UHPC layer at the bottom tensile zone of the composite beam and placing the normal-strength concrete (NC) layer at the upper compression zone, which is described as the UHPC-NC composite beam. The fatigue behavior of reinforced UHPC-NC composite beams was described in this study, with an emphasis on the effects of UHPC layer thickness and fatigue load level on the fatigue life of the beam, deformation of the interface between UHPC and NC layers, as well as the bending stiffness of the beam. A total of 9 reinforced UHPC-NC composite beams were tested under cyclic loading. The test variables include UHPC layer thicknesses (zero, 200, and 360 mm), reinforcement ratios (1.184% and 1.786%), and the upper load levels (0.39~0.65). The results showed that good bonding had been achieved without delamination between UHPC and NC layers prior to the final fatigue failure of the beam, and the bending stiffness of the composite beam experienced a three-stage reduction under cyclic loading. Furthermore, an equation was proposed to predict the stiffness reduction coefficient of UHPC-NC composite beams under cyclic loading.

Preparation and Properties of Gradient Sound-Absorbing Composites with Waste Feathers

To make full use of waste feather resources, waste feather fiber/polybutanediol succinate gradient sound-absorbing composites were prepared by a hot-pressing process with waste feather fiber as a reinforcing material and polybutanediol succinate as a matrix material. It can be applied to construction and other fields. The influence of gradient waste feather fiber mass fraction, gradient material density, and gradient material thickness on the sound-absorbing performance was studied, and the sound-absorbing mechanism of the material was analyzed. To determine the average sound-absorbing coefficient, maximum absorbing coefficient, and noise reduction coefficient as the evaluation index, the gradient sound-absorbing composites with waste feathers were compared with market common porous sound-absorbing materials with polyester fiber and wool fiber. The maximum sound-absorbing coefficient of the gradient sound-absorbing composites with waste feathers was 0.860; the average sound-absorbing coefficient was 0.408; the noise reduction coefficient was 0.393; and the noise reduction grade was IV. The sound-absorbing band was wide, and gradient sound-absorbing composites with waste feathers can be applied over a wide range.