Efficacy of Combined Phacoemulsification and Goniosynechialysis in the Treatment of Patients with Primary Angle Closure Disease and Concomitant Cataract at Preah Ang Duong Hospital in Cambodia

Background: Goniosynechialysis is a surgical procedure that has been shown to slow the progression of glaucoma in oriental eyes with chronic angle closure glaucoma. This procedure was successful in 80% of cases, and the peripheral anterior syenchiae did not exist until one year later. Nonetheless, there is little evidence of its efficacy in our context. Our study aims to investigate the efficacy of goniosynechialysis during phacoemulsification in patients with primary angle closure disease and concomitant cataract. Methods: This was an observational, prospective study. The intra-ocular pressure, need for anti-glaucoma drugs, visual acuity, the extent of synechiae, anterior chamber depth, surgical success rate, and other indicators were monitored for at least three months following surgery. Results: This study included 114 patients (118 eyes), 61 with chronic angle closure glaucoma (51.69%), 33 with primary angle closure (27.97%), and 24 with acute attack angle closure (20.34%), who were surgically treated with phacoemulsification and goniosynechialysis (Phaco-GSL). The mean intra-ocular pressure had significantly decreased three months after surgery (pre- vs post-op: 22.04 ± 10.86 vs 15.41 ± 6.06 mmHg, p-value p-value p-value p-value p-value Conclusion: Regardless of the type of glaucoma, combined phacoemulsification-goniosynechialysis is effective in lowering pressure, restoring vision, reducing the need for anti-glaucoma drugs, and preventing the synechial recurrence. Success was higher in eyes with less extensive synechiae. Phaco-GSL is safe and effective in the treatment of primary angle closure diseases with co-existing cataract.

Implications of fine water mist environment on the post-detonation processes of a PE4 explosive charge in a semi-confined blast chamber

The effects of a fine water mist environment in a semi-confined blast chamber on the chemical and thermodynamic processes following detonation of a 20 g PE4 explosive charge have been investigated.The effects were quantified by the analysis of pressure profiles recorded where several parameters including arrival time of the shock at the sensors, peak overpressures, specific impulse of the positive phase, period of the negative phase and the specific impulse of the multiple reflections were quantified.The effect of the fine water mist on the arrival time, peak pressures and the specific impulse of the positive phase agrees with previous findings in literature. In this paper, the focus is on the implications of the fine water mist on the negative phase and the impulse of multiple pressure reflections. The period of the negative phase was found to have increased by 40% and with higher negative peak pressure in the mist condition compared to the atmospheric condition. The activities of the multiple pressure reflections were found to have decreased considerably, both in number and in amplitude leading to lower impulses(by about 60%) for the water mist conditions.

Analyzing the Flow Field in the Oil Chamber of a Hydrostatic Guide Rail Used for Ultra-Precision Machining: Numerical Simulation and Performance Optimization

In order to explore the impact of different structural design parameters and environmental factors on the performance of the hydrostatic guide rail,the flow field inside its oil chamber is simulated,which provides direction and guidance for the design and optimization of the guide rail system.Based on the theory of fluid lubrication and the Reynolds equation,numerical simulations are performed through a mathematical model.The results suggest that the bearing capacity of the oil film increases with the oil supply pressure.The film thickness and the film stiffness share a positive correlation.Different oil film thickness and different input pressure parameters can have a significant impact on bearing capacity and oil film stiffness.The correlations identified in the present analysis can be used as a basis to optimize the guide rail design.

Effects of ultrasound on the desulfurization performance of hot coal gas over Zn-Mn-Cu supported on semi-coke sorbent prepared by high-pressure impregnation method

Zn-Mn-Cu/SC（U） sorbent was hydrothermally synthesized by ultrasound-assisted high-pressure impregnation method with semi-coke（SC）as support and the mixed solution of zinc nitrate,manganese nitrate and copper nitrate as active component precursors.The desulfurization performances of hot coal gas on the prepared sorbent at a mid-temperature of 500°C were tested in fixed-bed reactor.Morphology and pore structure of the prepared sorbent were also characterized by TEM,N2adsorption/desorption isotherms and XRD.For comparison,the sorbent of Zn-Mn-Cu/SC prepared by conventional high-pressure impregnation was also evaluated and characterized in order to study the effects of ultrasound treatment.Zn-Mn-Cu/SC（U） sorbent prepared by high-pressure impregnation under ultrasound-assisted condition showed a better desulfurization performance than Zn-Mn-Cu/SC.It could remove H2 S from 1000×10-6m3/m3 to 0.1×10-6m3/m3 at 500°C and maintained for 12.5 h with the sulfur capacity of 7.74%,in which both the breakthrough time and sulfur capacity were about 32% and 51% higher than those of Zn-Mn-Cu/SC sorbent.The introduction of ultrasound during high-pressure impregnation process greatly improved the morphology and pore structure of the sorbent.The ultrasonic treatment made particle size of active components smaller and made them more evenly disperse on semi-coke support,which provided more opportunities to contact with H2S in coal-based gases.However,there were no any difference in compositions and existing forms of active components on the Zn-Mn-Cu/SC and Zn-Mn-Cu/SC（U） sorbents.

Anatomical Evidence for the Neural Connection from the Emotional Brain to Autonomic Innervation in the Anterior Chamber Structures of the Eye

Objective Previous studies have shown that the autonomic nervous system(ANS),which can be affected by emotions,is important in the occurrence or progression of glaucoma.The autonomic innervation distributed in the anterior chamber(AC)structures might play an efferent role in the neural regulation of intraocular pressure(IOP).This study aimed to investigate the anatomic neural connection from the emotional brain to autonomic innervation in the AC.Methods A retrograde trans-multisynaptic pseudorabies virus encoded with an enhanced green fluorescent protein(PRV531)and non-trans-synaptic tracer FAST Dil were injected into the right eye of mice,respectively.Fluorescent localization in the emotional brain and preganglionic nuclei was studied.Five and a half days after PRV531 injection into the right AC,fluorescent signals were observed in several emotional brain regions,including the amygdala,agranular insular cortex,lateral septal nuclei,periaqueductal gray,and hypothalamus.Autonomic preganglionic nuclei,including Edinger-Westphal nucleus,superior salivatory nucleus,and intermediolateral nucleus,were labeled using PRV531.Results The sensory trigeminal nuclei were not labeled using PRV531.The fluorescence signals in the nuclei mentioned above showed bilateral distribution,primarily on the ipsilateral side.Seven days after injecting FAST Dil into the AC,we observed no FAST Dil-labeled neurons in the central nervous system.Conclusion Our results indicate a neural connection from the emotional brain to autonomic innervation in the AC,which provides anatomical support for the emotional influence of IOP via the ANS.

Numerical simulation of flow field characteristics and the improvement of pressure oscillation of rotating detonation engine

Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and improve propulsion performance.Therefore,in order to improve the characteristics of detonation flow field,the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper,and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field,which is a new method to regulate the detonation flow field.The results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber,which makes RDE be affected by rolling moment and results in the loss of axial kinetic energy.In the external flow field of combined chamber,the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed,which results in Mach disk structure.Moreover,the pressure monitoring points are set at the external flow field.The pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly weakened.Compared to the annular chamber,the relative standard deviation(RSD) has been reduced from 14.6% to5.6%.The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field,and is of great significance to promote the potential of RDE and nozzle design.

Based on the experimentation mathematical modeling and autoregulation realization for gas-collector pressure of coke furnace

Technical process and pressure control system of coke furnace were introduced.The mathematical model based on experimental method of gas-collector pressure wasproposed.To a certain extent, it is more reliable and dependable than mechanism method.Manufacturing process and experimental modeling can be finished at the same time, andfurthermore, the mathematical model can be established automatically.The realization algorithmof the total decoupling and on the line's modification for model value plays an importantrole in improving regulating quality.Finally, the DCS network structure to realizethe process was introduced.The control results show that the regulator can get reliableand robust performance.

An Experimental Determination of the Supply and Exhaust Pressures in an Electro-Pneumatic Clutch Actuation System

Inlet and outlet orifices in an actuation chamber are sources through which the supply and exhaust pressures pass during the actuation process in clutch systems. They are key ingredients in an actuation chamber and are very phenomenal in heavy-duty vehicle operation. It is these pressures that initiate linear or rotary motions in drive systems. The pressure actions are processed in an enclosure termed an actuation chamber. Oftentimes, the forces or pressures produced in an actuation chamber are unknown and immeasurable owing to a lack of precise instruments to accomplish them. This challenge can only be approached via an improvised technique that requires experimentation. This is precisely what this presentation is all about. The knowledge of these parameters is important in the study of the actuation process in electro-pneumatic clutch systems of heavy-duty vehicles. The study was done with a Mercedes Benz Actros Truck Model MP 2, 2031 Actuator chamber. An empirical and analytical approach was adopted. Meter rule, Venire Callipers and Mass Spring Balance were deployed for the experiments. Piston coil or spring, clutch distance in the actuator, the cross-sectional diameter of the actuator, and displacement in the free lengths of the coils among others were measured. The results of the experiments were analysed and used to determine the values of the supply (inlet) and exhaust (outlet) pressures which results stood at 9.61 bars and 11.299 bars, respectively.

Elimination of phosphorus vaporizing from molten silicon at finite reduced pressure

Elimination of phosphorus vaporizing from silicon was investigated. Si-P alloy made from electronic grade silicon was used. All the samples were analyzed by GD-MS. Theory calculation determines that phosphorus evaporates from molten silicon as gas species P and P2 at a finite reduced pressure. The experimental results show that phosphorus mass fraction can be decreased from 0.046% （460ppmw） to around 0.001% （10ppmw） under the condition of temperature 1 873 K, chamber pressure 0.6-0.8 Pa, holding time 1 h. Both experimental data and calculation results agree that at high phosphorus concentration, phosphorus removal is quite dependent on high chamber pressure while it becomes independent on low chamber pressure. The reason is that phosphorus evaporates from molten silicon as gas species P2 at a relatively high phosphorus concentration, while gas species P will be dominated in its vapour at low phosphorus content.

Vacuum chamber suppression of gas-explosion propagation in a tunnel

To control and reduce the harm of a gas explosion, a new method is proposed for suppressing gas-explosion propagation in a tunnel by using a vacuum chamber. We studied the suppression effect on gas explosions by placing a vacuum chamber at dif-ferent positions along the tunnel. The results indicate that: 1) the vacuum chamber can absorb the explosion wave and explosion energy as much as possible at the beginning of the gas explosion, and; 2) when the vacuum chamber is used the closer it is to the ignition source the more significant the suppression effect. In addition, by using the vacuum chamber: 1) the flame propagation velocity decreases from ultrasonic to subsonic; 2) the flame propagation distance is remarkably shortened; 3) the maximum peak value of overpressure (pm) decreases from 0.34 to 0.17 MPa or less, and; 4) the impulse of the blast wave (I) decreases from 20 to 8 kPa·s or less.

Fatigue behaviour of coke drum materials under thermal-mechanical cyclic loading

Coke drums are vertical pressure vessels used in the delayed coking process in petroleum refineries. Significant temperature variation during the delayed coking process causes damage in cracking. There were some studies on coke drums in the form of bulging and the fatigue life estimation for the coke drums, but most of them were based on strain-fatigue life curves at constant temperatures, which do not consider simultaneous cyclic temperature and mechanical loading conditions. In this study, a fatigue testing system is successfully devel- oped to allow performing thermal-mechanical fatigue （TMF） test similar to the coke drum loading condition. Two commonly used base and one clad materials of coke drums are then experimentally investigated. In addition, a comparative study between isothermal and TMF lives of these materials is conducted. The experimental findings lead to better understanding of the damage mechanisms occurring in coke drums and more accurate prediction of fatigue life of coke drum materials.

Optimal arrangement for pressure measurement points in working chamber of earth pressure balance shield

In order to exactly provide scientific basis for pressure dynamic balance control of working chamber of earth pressure balance shield (EPBS),study on optimal arrangement of pressure measurement points in working chamber was conducted. Based on mathematical description of optimal arrangement for pressure measurement points,fuzzy clustering analysis and discriminant analysis were used to divide pressure regions of nodes on bulkhead. Finally,the selection method of optimal measurement points was proposed,and by selecting d6.28 m EPBS as study object,the case study was conducted. By contrast,based on optimal arrangement scheme of pressure measurement points,through adopting weighted algorithm,the absolute error mean of equivalent pressure of working chamber is the smallest. In addition,pressure curve of optimal arrangement points presents parabola,and it can show the state of pressure distribution on bulkhead truly. It is concluded that the optimal arrangement method of pressure measurement points in working chamber is effective and feasible,and the method can provide basis for realizing high precision pressure control of EPBS.

The weeping characteristic of submerged multi-orifice plate

Weeping is an adverse phenomenon which results in higher pressure drop and poorer aeration performance.Visual experiments have been conducted to study the mechanism by which weeping impairs the work performance of multi-orifice plate.A theoretical model is improved to analyze the weeping phenomenon of multiorifice plate based on potential flow theory.The relations of different bubbling conditions and weeping rate are analyzed.Weeping condition and average weeping rate have relation with the driven pressure differential and dynamic variation of gas chamber pressure.In addition,a set of experiments are designed to study the influence of various factors on weeping rate.The bubble coalescence during bubble formation is a fatal factor determining weeping rate,so the relation between weeping rate and gas flow rate is concerned with the pitch of orifices and orifice diameter.There is a critical plate thickness which is in favor of weeping.

Impact of impregnation pressure on desulfurization performance of Zn-based sorbents supported on semi-coke

High-pressure impregnation, a new preparation method for sorbents to remove H2S from hot coal gas, is introduced in this paper. Semi-coke （SC） and ZnO is selected as the support and active component of sorbent, respectively. The sorbent preparation process includes high-pressure impregnation, filtration, ovendry and calcination. The aim of this research is to primarily study the effects of the impregnation pressure on physical properties and desulfurization ability of the sorbent. The desulfurization experiment was carried out in a fixed-bed reactor at 500 ~C and a simulated coal gas used in this work was composed of CO （33 vol%）, H2 （39 vol%）, H2S （300 ppm in volume）, and N2 （balance）. Experimental results show that the pore structure of the SC support can be improved effectively and ZnO active component can be uniformly dispersed on the support, with the small particle size of 10-500 nm. Sorbents prepared using high-pressure impregnation have better desulfurization capacity and their active components have higher utilization rate. P20-ZnSC sorbent, obtained by high-pressure impregnation at 20 atm, has the best desulfurization ability with a sulfur capacity of 7.54 g S/100g sorbent and a breakthrough time of 44 h. Its desulfurization precision and efficiency of removing H2S from the middle temperature gases can reach 〈 1 ppm and 〉99.7%, respectively, before sorbent breakthrough.

The Mineralisation Process as Deduced from Sr Isotopic Data from Lonplats' Eastern Platinum Mine,Western Bushveld Complex and Large-Scale Geometry of the Floor to the Merensky Reef

At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allows for a more detailed investigation of processes that are normally telescoped to the point of being irresolvable.Very minor platinum-group element(PGE)

Differences in Root Growth and Permeability in the Grafted Combinations of Dutch Tomato Cultivars (Starbuck and Maxifort) and Japanese Cultivars (Reiyo, Receive, and Magnet)

Grafting is widely established in agriculture and provides practical advantages for vegetable production. We investigated physiological differences between the grafted combinations of Dutch (Starbuck and Maxifort) and Japanese (Reiyo, Receive and Magnet) tomato cultivars. Plants were grown hydroponically until the flowers on the first truss bloomed, and the following parameters were measured: fresh weight of the aerial parts, root surface area, root permeability (by using a pressure chamber), and water potential of exudates (by using an isopiestic psychrometer). The Starbuck/Maxifort combination had higher values of the aerial part weight, root surface area, and root permeability than Reiyo/Receive, whereas Reiyo/Maxifort tended to have higher values of these parameters than Reiyo/Receive and Reiyo/Magnet. Maxifort had a significantly larger root surface area than Receive, but root permeability was not significantly different. InReiyo/Maxifort and Starbuck/Receive, these parameters were not significantly different except for a single comparison of root permeability. Thus, root permeability and root surface area may depend not only on the rootstock but be also affected by scion in grafted plants. Water potential of exudates was similar in most combinations and experiments. This shows that three rootstock cultivars provided similar nutrient concentrations even with different scions.

Dynamic calibration method of capacitive pressure measuring device

This paper presents working principle,structure and a dynamic calibration method of capacitive pressure measuring device.Using this method,placing calibrated capacitive electronic pressure measuring device and three standard sensors in simulation chamber pressure generator is proper and the data generated by them are analyzed and compared.This calibration method realizes dynamic calibration of capacitive electronic pressure measuring device under actual working pressure;pressure signal and frequency spectrum are analyzed.The experimental results show that simulation chamber pressure calibration method is feasible.

Buckling Properties of a Subsea Function Chamber for Oil/Gas Processing in Deep Waters

Due to the complexity of installations and connections of subsea production equipment and the massive structures involved in a challenging environment,the failure of subsea production equipment could induce enormous loss to the safety and reliability of structures in addition to the cost of the oilfield development.One of the challenges that the subsea production structures face,as it moves to ultra-deep water and polar underwater equipment,is to design subsea shell structures capable of withstanding high external pressures.Hence,a subsea function chamber(SFC)has been lately proposed as a viable solution,which has a high level of safety and reliability,and a technique for the subsea production system.This paper presents a general and efficient buckling and collapse analysis strategy.In this work,the SFC is composed of cylindrical and hemispherical shaped steel material.Initial imperfection-based nonlinear buckling analysis has been carried out to investigate the buckling and risks associated with different thicknesses of the structure.Linear and nonlinear static buckling analyses have been carried out using ABAQUS software.By introducing the nonlinear properties of materials,the nonlinear numerical model of SFC is established.The effects of the thickness of differentmodels and the number of stiffeners on the bucklingmodes are discussed.The wall thickness is calculated by the Donnell equation and Timoshenko’s classical method.It has been found that the classical solutions given by the Donnell and Timoshenko equations are more accurate for structures with larger lengths and diam.The thickness and number of stiffeners have a great influence on the ultimate buckling external pressure load of SFC structure.

Measurement of Sound Pressure Levels in Anechoic Chamber and a Noisy Environment Experimentally

In real life, when a noise problem occurs, it is important to identify the cause and measure the noise of the source, since it may affect human beings or other constructions due to vibration generated from noise, so it is necessary to determine the noise related to a specific source like a machine in the presence of other sources which is a very important approach in noise control engineering. In this article a full experiment was executed to measure the sound pressure levels of various sources (stationary and non-stationary), in both an anechoic chamber and a non-ideal noisy environment. The sound pressure level was extracted for different sources and compared for both ideal and non-ideal environment. The results showed that acoustical free field of the space is the best field to do measurements to avoid reflection, on the other hand the difference between the source and the background should be more than 3 dB to get better results.

Spectral characteristics of underwater laser-induced breakdown spectroscopy under high-pressure conditions

Laser-induced breakdown spectroscopy(LIBS) has been proven to be an attractive technique for in situ oceanic applications.However,when applying LIBS into deep-sea,the pressure effect caused by different ocean depths is inescapable and could have great influence on the LIBS signals.In this work,spectral characteristics of underwater LIBS were investigated as a function of pressure in the range of 0.1-45 MPa.A high-pressure chamber built in the laboratory was used to simulate the high-pressure deep-sea environment.Optimal laser energy and detection delay were first determined under different pressure conditions and were shown to be independent of the external pressure.The increase in pressure has a significant impact both on the peak intensity and line broadening of the observed spectra.The peak intensity of Na,Li and K lines increases with the increasing pressure until a maximum intensity is reached at 12.5 MPa.Above this value,the peak intensity decreases gradually up to 45 MPa.For Ca line,the maximum intensity was observed at 30 MPa.The line broadening keeps constant at low pressures from 0.1-10 MPa,while it increases linearly at higher pressures,indicating a higher electron density caused by the compression effect of the high external pressure.We also compared the spectral data obtained from the high-pressure chamber and from the field sea trials,and the good consistency between the laboratory data and sea-trial data suggested the key role of pressure effect on underwater LIBS signals for practical deep-sea applications.