Background:The surgical management of patients with benign prostatic hyperplasia(BPH)has considerably evolved through recent years.Nonetheless,benefits and harms of several laser procedures are still to be determined....Background:The surgical management of patients with benign prostatic hyperplasia(BPH)has considerably evolved through recent years.Nonetheless,benefits and harms of several laser procedures are still to be determined.The study aimed to report perioperative and early functional results of patients treated with anatomical photo vaporization of the prostate(aPVP).Methods:Data from consecutive patients treated with aPVP by using a 180-W XPS GreenLight laser were prospectively collected in a single tertiary center between 2020 and 2023.The surgical procedure was divided into a modular step-by-step fashion.Patients were asked to complete self-administered questionnaires at baseline and during follow-up visits.Results:Overall,176 consecutive patients were enrolled.Median age was 65[interquartile range(IQR)63–72]years.The baseline median prostate volume was 61.2(IQR 52.5–71.0)mL,and the median max flow rate(Qmax)was 9.3(IQR 7.8–11.5)mL/s.Median preoperative International Prostate Symptom Score(IPSS)was 25(IQR 22–29).Overall,the median operative time was 42(IQR 31–47)minutes with a median energy/mL of tissue delivered of 2447 kJ/mL.At 3 month-evaluation,significant improvements were observed,with a median Qmax of 28(IQR:24–32)mL/s and a median IPSS reduction of 15(IQR:11–18)points.A strong inverse correlation was identified between energy delivery during initial procedural steps and the severity of postoperative storage symptoms(all p<0.05),underscoring the importance of precise energy modulation.Multivariate analysis identified increased prostate volume(odds ratio[OR]:1.02;95%confidence interval[CI]1.01–1.11;p=0.001)and higher prostate width-to-length ratio(OR:1.28;95%CI 1.04–1.78;p=0.03)as independent predictors of increased energy requirements.Conclusions:aPVP with 180-W XPS GreenLight laser is a safe and effective technique showing worthy early functional results.The limitation of the energy delivered in some key phases of the procedure may be associated with a significant reduction in postoperative irritative symptoms.The shape and dimensions of the prostate also play a critical role in determining the total energy required for complete adenoma removal.展开更多
The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs si...The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs significantly from that observed in sand gas condensate reservoirs. However, studies on improving the recovery of fractured gas condensate reservoirs are limited;thus, the impact of retrograde vaporization on condensate within fractured metamorphic buried-hill reservoirs remains unclear. To address this gap, a series of gas injection experiments are conducted in pressure-volume-temperature(PVT) cells and long-cores to investigate the retrograde vaporization effect of condensate using different gas injection media in fractured gas condensate reservoirs. We analyze the variation in condensate volume, gas-to-oil ratio, and condensate recovery during gas injection and examine the influence of various gas injection media(CO_(2), N_(2), and dry gas) under different reservoir properties and varying gas injection times. The results demonstrate that the exchange of components between injected gas and condensate significantly influences condensate retrograde vaporization in the formation. Compared with dry gas injection and N_(2) injection,CO_(2) injection exhibits a superior retrograde vaporization effect. At a CO_(2) injection volume of 1 PV, the percentage shrinkage volume of condensate is 13.82%. Additionally, at the maximum retrograde condensation pressure, CO_(2) injection can increase the recovery of condensate by 22.4%. However, the condensate recovery is notably lower in fractured gas condensate reservoirs than in homogeneous reservoirs, owing to the creation of dominant gas channeling by fractures, which leads to decreased condensate recovery. Regarding gas injection timing, the effect of gas injection at reservoir pressure on improving condensate recovery is superior to that of gas injection at the maximum retrograde condensation pressure. This research provides valuable guidance for designing gas injection development plans and dynamic tracking adjustments for fractured gas condensate reservoirs.展开更多
Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporizatio...Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporization temperatures are very high for a liquid that is neither ionic nor metallic, and whose molar mass is low. Thus, water remains liquid at atmospheric pressure up to 100C while similar molecules such as H2S, H2Se, H2Te for example would give a vaporization temperature close to 80C. This cohesion is in fact ensured by hydrogen bonds between water molecules. This type of bonds between neighboring molecules, hydrogen bonds, is quite often found in chemistry [1] [2]. Any change in the state of aggregation of a substance occurs with the absorption or release of a certain amount of latent heat of transformation. Latent heat of fusion, vaporization or sublimation is the ratio of the energy supplied as heat to the mass of the substance that is melted, vaporized or sublimated. As a result of the reversibility of the processes, the fusion heat is equal to the heat released in the reverse process: crystallization and solidification heat. And likewise the heat of vaporization is equal to the heat of condensation. This equality of heat is often used to determine experimentally either of these quantities. There are two main measurement methods: 1) Direct measurement using the calorimeter, 2) Indirect measure based on the use of the VantHoff relationship. The objective of this work is to measure the latent heat of water vaporization and verify the compatibility of the experimental values with the values given by the tables using the indirect method.展开更多
This study presents a contribution to the development of a model for vegetable oil droplets vaporization, with a particular focus on the influence of the experimental set-up for their use as fuel in diesel engines. Tw...This study presents a contribution to the development of a model for vegetable oil droplets vaporization, with a particular focus on the influence of the experimental set-up for their use as fuel in diesel engines. Two systems were considered: an open-environment system obtained through a hot gas flow, and a closed-environment system. Vaporization was conducted under identical conditions, with the results subsequently compared. The findings indicate that, for temperatures between 473 K and 673 K, droplets behaviour in both systems presents only a heating and expansion phase. For temperatures above 673 K, the behaviour of the droplets differs between the devices. In the open environment device, a linear reduction in droplets diameter is observed following the transient phase, suggesting stationary vaporization and enabling the calculation of a vaporization constant and the well-known D2 law is respected. In the closed-environment device, puffing, micro-explosions and gas ejections are observed, and it is not possible to determine vaporization constant and D2 law is not respected. The results demonstrate the necessity of developing a model for the thermal decomposition of vegetable oil before attempting to create a model for the vaporization of these oils. In order to achieve this, it is essential to construct an experimental setup that more closely emulates the real conditions within the combustion chamber of a diesel engine, taking into account the variables of pressure, temperature and the heating process.展开更多
The high concentration of heavy metal (Cu, Cr, Zn, Pb) in tannery sludge causes severe heavy metal emissions in the process of incineration. In the present investigation, the tannery sludge was treated with 85% phosph...The high concentration of heavy metal (Cu, Cr, Zn, Pb) in tannery sludge causes severe heavy metal emissions in the process of incineration. In the present investigation, the tannery sludge was treated with 85% phosphoric acid before the incineration process in the tube furnace to control the heavy metal emissions. The thermal behavior and heavy metal vaporization of pre-treated tannery sludge were investigated, and X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were also implemente...展开更多
Aim： To explore the feasibility and safety of greenlight photoselective vaporization of the prostate （PVP） on high-risk patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplas...Aim： To explore the feasibility and safety of greenlight photoselective vaporization of the prostate （PVP） on high-risk patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia （BPH） and to evaluate their clinical and voiding outcome. Methods： A total of 85 high-risk patients with obstructive BPH underwent PVP with an 80 W potassium-titanyl-phosphate laser, which was delivered through a side-deflecting fiber with a 23 Fr continuous flow cystoscope. Operative time, blood loss, indwelling catheterzation, international prostate symptom score （IPSS）, quality of life score （QoL）, uroflowmetry, postvoid residual urine volume and short-term complication rates were evaluated for all patients. Results： All patients got through the perioperative period safely. The chief advantages of PVP were： short operative time （25.6 ± 7.6 min）, little bleeding loss （56.8 ± 14.3 mL） and short indwelling catheterization （1.6 ± 0.8 d）. The IPSS and QoL decreased from （29.6 ± 5.4） and （5.4 ± 0.6） to （9.5 ± 2.6） and （1.3 ± 0.6）, respectively. The vast majority of patients were satisfied with voiding outcome. The mean maximal urinary flow rate increased to 17.8 mL/s and postvoid residual urine volume decreased to 55.6 mL. These results are significantly different from preoperative data （P 〈 0.05）. No patient required blood transfusion or fluid absorption. There were few complications and very high patient satisfaction after operation. Conclusion： PVP has a short operative time and high tolerance, and is safe, effective and minimally invasive for high-risk patients, therefore it might be considered as a good alternative treatment for high-risk patients with obstructive urinary symptoms as a result of BPH.展开更多
The vaporization ratios of the slurry at various temperature and partial pressure were calculated with the group-contribution method,and then the phase state of the slurry in the residue fluid catalytic cracking(RFCC)...The vaporization ratios of the slurry at various temperature and partial pressure were calculated with the group-contribution method,and then the phase state of the slurry in the residue fluid catalytic cracking(RFCC) disengager was determined.This research could provide some advices on how to select the technological conditions to decrease the coking in the RFCC disengager.The oil gas temperature and the slurry partial pressure had signifi- cant effects on the vaporization ratio of the slurry.Increasing the oil gas temperature and reducing the slurry partial pressure could effectively slow down the coking speed in the RFCC disengager.According to the calculation results, a correlation was established to predict the vaporization ratio of the slurry under different operating conditions.展开更多
In order to improve the calorific value and the recovery yield of converter gas during the steelmaking process, a novel and thermodynamically admissible process was proposed. This method involved injecting pulverized ...In order to improve the calorific value and the recovery yield of converter gas during the steelmaking process, a novel and thermodynamically admissible process was proposed. This method involved injecting pulverized coal into the vaporization cooling flue of a converter, and the approach was developed based on an industrial 30 t converter. The effects of temperature, O2 content, and the volumetric ratio of CO to CO2 on the conversion of the mixed components of gas were analyzed using thermodynamic calculations. Furthermore, the effect of the injection rate on the quality and quantity of gas was investigated. The results show that the O2 and CO2 components of flue gas decrease as the injection rate increases, whereas the CO and H2 components synchronously increase. With the injection rate of 30 kg min-1, the 02 and CO2 components of the gas decreased by 64.12 and 41.19%, respectively, while the CO and H2 increased by 20.09 and 236.84%, respectively, and the recovery time of gas increased by 11.61%, compared to non-injection.展开更多
Aqueous ammonia （NH3） solution can be used as an alternative absorption for the control of CO2 emitted from flue gases due to its high absorption capacity, fast absorption rate and low corrosion problem. The emissio...Aqueous ammonia （NH3） solution can be used as an alternative absorption for the control of CO2 emitted from flue gases due to its high absorption capacity, fast absorption rate and low corrosion problem. The emission of CO2 from iron and steel plants requires much attention, as they are higher than those emitted from power plants at a single point source. In the present work, low concentration ammonia liquor, 9 wt.%, was used with various additives to obtain the kinetic properties using the blast furnace gas model. Although a solution with a high ammonia concentration enables high CO2 absorption efficiency, ammonium ions are lost as ammonia vapor, resulting in reduced CO2 absorption due to the lower concentration of the ammonia absorbent. To decrease the vaporization of ammonia, ethylene glycol, glycerol and glycine, which contain more than one hydroxyl radical, were chosen. The experiments were conducted at 313 K similar to the CO2 absorption conditions for the blast furnace gas model.展开更多
Vaporization behavior （1163-1463 K） of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaC% was examined. A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapo...Vaporization behavior （1163-1463 K） of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaC% was examined. A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapor species from the sample of the FeO-CaO-SiO2-Al2O3 system＋PbO＋CaCl2 were metallic Pb, PbCl, PbCl2, and FeCl2, at the experimental temperature range. The experimental results show that the mole ratio of vaporized Cl in lead chlorides to vaporized Pb, simply expressed as Cl/Pb decreases with increasing temperature. The larger Cl/Pb means a larger ratio of gaseous PbCl2, since metallic Pb and PbCl vapors are formed in a similar reduction atmosphere. The evaporation is initially rapid and becomes steady after holding for 10 min. Gaseous PbCl2 is mainly formed during the heating period, and at the holding stage, it reacts with FeO to produce gaseous FeCl2 With regard to slag composition, FeO content and basicity significantly affect the evaporation of lead. High FeO content and high basicity promotes the formation of metallic Pb and PbCI, whereas, it prohibits PbCl2 evaporation.展开更多
The volume of fluid(VOF) formulation is applied to model the combustion process of a single droplet in a hightemperature convective air free stream environment.The calculations solve the flow field for both phases,and...The volume of fluid(VOF) formulation is applied to model the combustion process of a single droplet in a hightemperature convective air free stream environment.The calculations solve the flow field for both phases,and consider the droplet deformation based on an axisymmetrical model.The chemical reaction is modeled with one-step finite-rate mechanism and the thermo-physical properties for the gas mixture are species and temperature dependence.A mass transfer model applicable to the VOF calculations due to vaporization of the liquid phases is developed in consideration with the fluctuation of the liquid surface.The model is validated by examining the burning rate constants at different convective air temperatures,which accord well with experimental data of previous studies.Other phenomena from the simulations,such as the transient history of droplet deformation and flame structure,are also qualitatively accordant with the descriptions of other numerical results.However,a different droplet deformation mechanism for the low Reynolds number is explained compared with that for the high Reynolds number.The calculations verified the feasibility of the VOF computational fluid dynamics(CFD) formulation as well as the mass transfer model due to vaporization.展开更多
To investigate the factors that influence treatment satisfaction after high-power potassium-titanyl-phosphate （KTP） laser vaporization of the prostate, we compared the characteristics between patients who were satis...To investigate the factors that influence treatment satisfaction after high-power potassium-titanyl-phosphate （KTP） laser vaporization of the prostate, we compared the characteristics between patients who were satisfied and those who were not satisfied. In all, 97 patients aged between 53-82 years （median age 67 years） underwent high-power KTP laser vaporization of the prostate for lower urinary tract symptoms due to benign prostatic hyperplasia. At 12 months postoperatively, 60 patients were satisfied with the treatment, whereas 37 were dissatisfied. Although there were no differences in International Prostate Symptom Score （IPSS） values at baseline, the satisfied group scored better in total IPSS at 1, 3, 6, and 12 months postoperatively （P 〈 0.05）. At baseline, the maximum flow rate （Qmax） was lower in the dissatisfied group and remained low throughout the follow-up period, with the exception of 1 month postoperatively （P 〈 0.05）, compared with the satisfied group. There were no differences in other objective data between the two groups, including post-void residual and the number of voids based on the frequency-volume charts. In a multivariate model, a higher bladder contractility index was associated with a greater likelihood of treatment satisfaction 12 months after high-power KTP laser vaporization （odds ratio 1.024, 95% confidence interval 1.001-1.048, P 〈 0.05）. Patients who were not satisfied following the surgery had a smaller improvement in subjective symptoms and Qmax. In addition, our findings suggest that the relative risk of treatment dissatisfaction following high-power KTP laser vaporization was increased in patients with weak detrusor contractility.展开更多
A method for determination of trace rare earth elements in biological sample by ICP-AES with tungsten-spiral electrothermal vaporization(TETV-ICP-AES)sampling has been developed in this work. Several influencing facto...A method for determination of trace rare earth elements in biological sample by ICP-AES with tungsten-spiral electrothermal vaporization(TETV-ICP-AES)sampling has been developed in this work. Several influencing factors including desolvation and vaporization parameters,carrier gas flow rate and ma- trix effect were investigated in detail.Under optimal experimental conditions,the detection limits for La,Nd, Gd,Dy,Ho,Yb,Lu and Y were obtained in the range of 10^(-9)～10^(-11) g,and they are comparable to and,in most instances,better than those for the GFAAS and conventional pneumatic nebulisation-ICP-AES.The precision(RSD)obtained for this method is less than 6%.展开更多
The past literature on the use of vegetable oils as fuel in diesel engine revealed that utilizing vegetable oil fuels in diesel engines may require property changes in the oil or perhaps, some minor engine modificatio...The past literature on the use of vegetable oils as fuel in diesel engine revealed that utilizing vegetable oil fuels in diesel engines may require property changes in the oil or perhaps, some minor engine modifications or operating changes. This study was conducted to search for the effect of atmospheric oxygen on the puffing and bursting phenomena that occur during vegetable oils droplet vaporization process in their use as fuel in diesel engine. The fiber-suspended droplet technique was used, and the normalized square droplet diameter as well as the temperature evolution vicinity the droplet was analyzed. The results show that puffing and bursting phenomena highly depend on oxygen. In presence of atmospheric oxygen, there is an increase of the puffing and bursting intensity and therefore the evaporation rate of the vegetable oil droplets, but in an inert environment or when the environment is oxygen-depleted puffing and bursting phenomena disappearing and make place of a series of explosions with lower magnitude. The lack of oxygen reduces the thermal degradation, polymerization and oxidation reactions and consequently the vaporization rate of vegetable oils droplets;and could therefore lead to the formation of deposits in the form of polymers. This is unsuitable for their use as a fuel in diesel engines. It can also be concluded that atmospheric oxygen has some positive effects on engine performance and emissions when operating with vegetable oil. These results help to address the challenge for the use of alternative fuels such as non-edible vegetable oils.展开更多
The bis(N-ethyl-5-methylsalicylaldimine)nickel(II) [Ni(5-me-saletN)2] complex was synthesized and characterized by elemental analyses, FT-IR, TG-DTA, mass spectrometry and vapour pressure measurement studies. The TG c...The bis(N-ethyl-5-methylsalicylaldimine)nickel(II) [Ni(5-me-saletN)2] complex was synthesized and characterized by elemental analyses, FT-IR, TG-DTA, mass spectrometry and vapour pressure measurement studies. The TG curve of the complex showed a single-step weight loss commencing from 490 K to nil residue at 600 K, without competing fragmentation step. The non-isothermal vaporization activation energy value determined by Coats-Redfern method yielded the value of 93.5 ± 7 kJmol–1. The dynamic TG run proved the complex to be completely volatile. And the equilibrium vapour pressure of the complex over the temperature range of 421 - 524 K, determined by the TG-based transpiration technique yielded the value of 94.2 ± 1.2 kJmol–1 for its standard enthalpy of vaporization . The entropy of vaporization was calculated from the intercept and found to be 249.4 ± 2.6 Jmol–1•K–1.展开更多
A new method for direct determination of lanthanum in solid biological materials by fluorination electrothermal vaporization ICP-AES technique with polytetrafluoroethylene(PTFE)disperser as a fluorination agent has be...A new method for direct determination of lanthanum in solid biological materials by fluorination electrothermal vaporization ICP-AES technique with polytetrafluoroethylene(PTFE)disperser as a fluorination agent has been described.The effect of particle size on the signal intensity of La has been investigated.The vaporization behaviour of lanthanum and the main factors affecting fluorinating vaporization have been observed.Under optimum experimental conditions,the detection limit of La to this method is 2.0 ng/ml,and the RSD is 4.5%.The proposed method has been applied to determining directly trace lanthanum in solid biological standard reference materials without any chemical pretreatment,and the determined values are in good agreement with the certified ones.展开更多
Three series of laboratory vaporization experiments were conducted to investigate the carbon isotope fractionation of low molecular weight hydrocarbons（LMWHs）during their progressive vaporization.In addition to the ...Three series of laboratory vaporization experiments were conducted to investigate the carbon isotope fractionation of low molecular weight hydrocarbons（LMWHs）during their progressive vaporization.In addition to the analysis of a synthetic oil mixture,individual compounds were also studied either as pure single phases or mixed with soil.This allowed influences of mixing effects and diffusion though soil on the fractionation to be elucidated.The LMWHs volatilized in two broad behavior patterns that depended on their molecular weight and boiling point.Vaporization significantly enriched the ^13C present in the remaining components of the C6–C9 fraction,indicating that the vaporization is mainly kinetically controlled;the observed variations could be described with a Rayleigh fractionation model.In contrast,the heavier compounds（n-C10–n-C12）showed less mass loss and almost no significant isotopic fractionation during vaporization,indicating that the isotope characteristics remained sufficiently constant for these hydrocarbons to be used to identify the source of an oil sample,e.g.,the specific oil field or the origin of a spill.Furthermore,comparative studies suggested that matrix effects should be considered when the carbon isotope ratios of hydrocarbons are applied in the field.展开更多
According to graph theory method, new method is proposed for the prediction or vaporization heat at normal boiling point of paraffins with moleeular,atructure, and it is compared with other methods. We predict the. va...According to graph theory method, new method is proposed for the prediction or vaporization heat at normal boiling point of paraffins with moleeular,atructure, and it is compared with other methods. We predict the. vaporization heat at normal boiling point for 57 different paraffins, and that is compared with experimental data, its overall, absolute average deviation is 0.61%. The result is,superior to other methods.展开更多
Objectives:To compare the depth of thermal necrosis after use of bipolar resection and vaporization technique comparing intra-individually bipolar loop and bipolar button electrodes.Methods:Transurethral resection and...Objectives:To compare the depth of thermal necrosis after use of bipolar resection and vaporization technique comparing intra-individually bipolar loop and bipolar button electrodes.Methods:Transurethral resection and vaporization of the prostate was performed in 55 male patients(260 specimens in total).In a standardized procedure,a bipolar resection loop was used for resection,and a bipolar button electrode was used for vaporization.Both electrodes were applied in each patient,either in the left or in the right lateral lobe.The depth of necrotic zones in the resected or vaporized tissue of each patient was measured in a standardized way by light microscopy.Results:The mean depth with standard deviation of thermal injury caused by the loop electrode was 0.0495±0.0274 mm.The vaporization electrode caused a mean thermal depth with standard deviation of 0.0477±0.0276 mm.The mean difference of necrosis zone depths between the two types of electrodes(PlasmaButtoneresection loop)was 0.0018 mm(p=0.691).Conclusion:For the first time,we present directly measured values of the absolute necrosis zone depth after application of plasma in the transurethral treatment of benign prostatic hyperplasia.The measured values were lower than in all other transurethral procedures.Standardized procedures of measurement and evaluation allow a statistically significant statement that the low necrosis depth in bipolar procedures is independent of the applied electrodes.展开更多
In this study, the vaporization ratio of the 2-μm laser in the prostatic tissue with benign prostatic hyperplasia was examined in vitro, to explore a technique to estimate the clearance rate of prostatic tissue durin...In this study, the vaporization ratio of the 2-μm laser in the prostatic tissue with benign prostatic hyperplasia was examined in vitro, to explore a technique to estimate the clearance rate of prostatic tissue during the transurethral vaporesection of the prostate. A total of 9 fresh prostatic tissue specimens were obtained by open surgery and the wet weight of the prostatic tissue were measured immediately after the sample collection. Under the simulated conditions of transurethral vaporesection of the prostate by 2-μm laser, each prostate gland was completely vaporesected into fragments with a diameter of less than 1.0 cm in vitro tissue were collected and measured. Then After the vaporesection, the whole fragments of prostatic the lost weight of prostatic tissue, the weight of the collected prostatic tissue and the ratio of the lost weight of prostatic tissue to the wet weight of the prostate glandular organ specimen were calculated. The correlation between the weight of collected prostatic tissue and the weight of the whole glandular organ was analyzed. All the experimental procedures were carried out by one operator. Wet weight of the prostatic gland specimen and the weight of the harvested prostatic tissues after the procedure were recorded. With respect to the wet weight of prostate gland specimen, the percentage of the weight of collected prostatic tissue was （34.45±1.51） %, and the percentage of the lost weight of prostatic tissue was （65.55±1.51）%. Satisfactory linear relationship was observed between the weight of collected prostatic tissue and the wet weight of prostate gland specimen [y=3.245x=6.475 （t=15.097, P=0.000）]. It is concluded that under the simulated conditions of transurethral vaporesection of the prostate by 2-μm laser, the vaporization ratio of prostatic tissue can be calculated on the basis of the weight of collected prostatic tissue, and thereby the clearance of prostatic tissue during the formal operation by 2-μm laser could be quantitatively determined.展开更多
文摘Background:The surgical management of patients with benign prostatic hyperplasia(BPH)has considerably evolved through recent years.Nonetheless,benefits and harms of several laser procedures are still to be determined.The study aimed to report perioperative and early functional results of patients treated with anatomical photo vaporization of the prostate(aPVP).Methods:Data from consecutive patients treated with aPVP by using a 180-W XPS GreenLight laser were prospectively collected in a single tertiary center between 2020 and 2023.The surgical procedure was divided into a modular step-by-step fashion.Patients were asked to complete self-administered questionnaires at baseline and during follow-up visits.Results:Overall,176 consecutive patients were enrolled.Median age was 65[interquartile range(IQR)63–72]years.The baseline median prostate volume was 61.2(IQR 52.5–71.0)mL,and the median max flow rate(Qmax)was 9.3(IQR 7.8–11.5)mL/s.Median preoperative International Prostate Symptom Score(IPSS)was 25(IQR 22–29).Overall,the median operative time was 42(IQR 31–47)minutes with a median energy/mL of tissue delivered of 2447 kJ/mL.At 3 month-evaluation,significant improvements were observed,with a median Qmax of 28(IQR:24–32)mL/s and a median IPSS reduction of 15(IQR:11–18)points.A strong inverse correlation was identified between energy delivery during initial procedural steps and the severity of postoperative storage symptoms(all p<0.05),underscoring the importance of precise energy modulation.Multivariate analysis identified increased prostate volume(odds ratio[OR]:1.02;95%confidence interval[CI]1.01–1.11;p=0.001)and higher prostate width-to-length ratio(OR:1.28;95%CI 1.04–1.78;p=0.03)as independent predictors of increased energy requirements.Conclusions:aPVP with 180-W XPS GreenLight laser is a safe and effective technique showing worthy early functional results.The limitation of the energy delivered in some key phases of the procedure may be associated with a significant reduction in postoperative irritative symptoms.The shape and dimensions of the prostate also play a critical role in determining the total energy required for complete adenoma removal.
文摘The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs significantly from that observed in sand gas condensate reservoirs. However, studies on improving the recovery of fractured gas condensate reservoirs are limited;thus, the impact of retrograde vaporization on condensate within fractured metamorphic buried-hill reservoirs remains unclear. To address this gap, a series of gas injection experiments are conducted in pressure-volume-temperature(PVT) cells and long-cores to investigate the retrograde vaporization effect of condensate using different gas injection media in fractured gas condensate reservoirs. We analyze the variation in condensate volume, gas-to-oil ratio, and condensate recovery during gas injection and examine the influence of various gas injection media(CO_(2), N_(2), and dry gas) under different reservoir properties and varying gas injection times. The results demonstrate that the exchange of components between injected gas and condensate significantly influences condensate retrograde vaporization in the formation. Compared with dry gas injection and N_(2) injection,CO_(2) injection exhibits a superior retrograde vaporization effect. At a CO_(2) injection volume of 1 PV, the percentage shrinkage volume of condensate is 13.82%. Additionally, at the maximum retrograde condensation pressure, CO_(2) injection can increase the recovery of condensate by 22.4%. However, the condensate recovery is notably lower in fractured gas condensate reservoirs than in homogeneous reservoirs, owing to the creation of dominant gas channeling by fractures, which leads to decreased condensate recovery. Regarding gas injection timing, the effect of gas injection at reservoir pressure on improving condensate recovery is superior to that of gas injection at the maximum retrograde condensation pressure. This research provides valuable guidance for designing gas injection development plans and dynamic tracking adjustments for fractured gas condensate reservoirs.
文摘Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporization temperatures are very high for a liquid that is neither ionic nor metallic, and whose molar mass is low. Thus, water remains liquid at atmospheric pressure up to 100C while similar molecules such as H2S, H2Se, H2Te for example would give a vaporization temperature close to 80C. This cohesion is in fact ensured by hydrogen bonds between water molecules. This type of bonds between neighboring molecules, hydrogen bonds, is quite often found in chemistry [1] [2]. Any change in the state of aggregation of a substance occurs with the absorption or release of a certain amount of latent heat of transformation. Latent heat of fusion, vaporization or sublimation is the ratio of the energy supplied as heat to the mass of the substance that is melted, vaporized or sublimated. As a result of the reversibility of the processes, the fusion heat is equal to the heat released in the reverse process: crystallization and solidification heat. And likewise the heat of vaporization is equal to the heat of condensation. This equality of heat is often used to determine experimentally either of these quantities. There are two main measurement methods: 1) Direct measurement using the calorimeter, 2) Indirect measure based on the use of the VantHoff relationship. The objective of this work is to measure the latent heat of water vaporization and verify the compatibility of the experimental values with the values given by the tables using the indirect method.
文摘This study presents a contribution to the development of a model for vegetable oil droplets vaporization, with a particular focus on the influence of the experimental set-up for their use as fuel in diesel engines. Two systems were considered: an open-environment system obtained through a hot gas flow, and a closed-environment system. Vaporization was conducted under identical conditions, with the results subsequently compared. The findings indicate that, for temperatures between 473 K and 673 K, droplets behaviour in both systems presents only a heating and expansion phase. For temperatures above 673 K, the behaviour of the droplets differs between the devices. In the open environment device, a linear reduction in droplets diameter is observed following the transient phase, suggesting stationary vaporization and enabling the calculation of a vaporization constant and the well-known D2 law is respected. In the closed-environment device, puffing, micro-explosions and gas ejections are observed, and it is not possible to determine vaporization constant and D2 law is not respected. The results demonstrate the necessity of developing a model for the thermal decomposition of vegetable oil before attempting to create a model for the vaporization of these oils. In order to achieve this, it is essential to construct an experimental setup that more closely emulates the real conditions within the combustion chamber of a diesel engine, taking into account the variables of pressure, temperature and the heating process.
基金the Education Ministryof China (No. 305005)the Department of Sci-ence and Technology of Zhejiang Province, China (No.2007C210054)
文摘The high concentration of heavy metal (Cu, Cr, Zn, Pb) in tannery sludge causes severe heavy metal emissions in the process of incineration. In the present investigation, the tannery sludge was treated with 85% phosphoric acid before the incineration process in the tube furnace to control the heavy metal emissions. The thermal behavior and heavy metal vaporization of pre-treated tannery sludge were investigated, and X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were also implemente...
文摘Aim： To explore the feasibility and safety of greenlight photoselective vaporization of the prostate （PVP） on high-risk patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia （BPH） and to evaluate their clinical and voiding outcome. Methods： A total of 85 high-risk patients with obstructive BPH underwent PVP with an 80 W potassium-titanyl-phosphate laser, which was delivered through a side-deflecting fiber with a 23 Fr continuous flow cystoscope. Operative time, blood loss, indwelling catheterzation, international prostate symptom score （IPSS）, quality of life score （QoL）, uroflowmetry, postvoid residual urine volume and short-term complication rates were evaluated for all patients. Results： All patients got through the perioperative period safely. The chief advantages of PVP were： short operative time （25.6 ± 7.6 min）, little bleeding loss （56.8 ± 14.3 mL） and short indwelling catheterization （1.6 ± 0.8 d）. The IPSS and QoL decreased from （29.6 ± 5.4） and （5.4 ± 0.6） to （9.5 ± 2.6） and （1.3 ± 0.6）, respectively. The vast majority of patients were satisfied with voiding outcome. The mean maximal urinary flow rate increased to 17.8 mL/s and postvoid residual urine volume decreased to 55.6 mL. These results are significantly different from preoperative data （P 〈 0.05）. No patient required blood transfusion or fluid absorption. There were few complications and very high patient satisfaction after operation. Conclusion： PVP has a short operative time and high tolerance, and is safe, effective and minimally invasive for high-risk patients, therefore it might be considered as a good alternative treatment for high-risk patients with obstructive urinary symptoms as a result of BPH.
基金Supported by the National-Natural Science Foundation of China （No.20406013） and Program for New Century Excellent Talents in University （No.NCET-04-0107）.
文摘The vaporization ratios of the slurry at various temperature and partial pressure were calculated with the group-contribution method,and then the phase state of the slurry in the residue fluid catalytic cracking(RFCC) disengager was determined.This research could provide some advices on how to select the technological conditions to decrease the coking in the RFCC disengager.The oil gas temperature and the slurry partial pressure had signifi- cant effects on the vaporization ratio of the slurry.Increasing the oil gas temperature and reducing the slurry partial pressure could effectively slow down the coking speed in the RFCC disengager.According to the calculation results, a correlation was established to predict the vaporization ratio of the slurry under different operating conditions.
文摘In order to improve the calorific value and the recovery yield of converter gas during the steelmaking process, a novel and thermodynamically admissible process was proposed. This method involved injecting pulverized coal into the vaporization cooling flue of a converter, and the approach was developed based on an industrial 30 t converter. The effects of temperature, O2 content, and the volumetric ratio of CO to CO2 on the conversion of the mixed components of gas were analyzed using thermodynamic calculations. Furthermore, the effect of the injection rate on the quality and quantity of gas was investigated. The results show that the O2 and CO2 components of flue gas decrease as the injection rate increases, whereas the CO and H2 components synchronously increase. With the injection rate of 30 kg min-1, the 02 and CO2 components of the gas decreased by 64.12 and 41.19%, respectively, while the CO and H2 increased by 20.09 and 236.84%, respectively, and the recovery time of gas increased by 11.61%, compared to non-injection.
基金supported by a grant from the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP)funded by the Korean Government’s Ministry of Knowledge Economy (No. 20092010200011-12-1-000)the Korean Ministry of the Environment (MOE) as the "Human Resource Development Project for Waste to Energy"
文摘Aqueous ammonia （NH3） solution can be used as an alternative absorption for the control of CO2 emitted from flue gases due to its high absorption capacity, fast absorption rate and low corrosion problem. The emission of CO2 from iron and steel plants requires much attention, as they are higher than those emitted from power plants at a single point source. In the present work, low concentration ammonia liquor, 9 wt.%, was used with various additives to obtain the kinetic properties using the blast furnace gas model. Although a solution with a high ammonia concentration enables high CO2 absorption efficiency, ammonium ions are lost as ammonia vapor, resulting in reduced CO2 absorption due to the lower concentration of the ammonia absorbent. To decrease the vaporization of ammonia, ethylene glycol, glycerol and glycine, which contain more than one hydroxyl radical, were chosen. The experiments were conducted at 313 K similar to the CO2 absorption conditions for the blast furnace gas model.
基金supported by the National Natural Science Foundation of China (No.50704004)
文摘Vaporization behavior （1163-1463 K） of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaC% was examined. A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapor species from the sample of the FeO-CaO-SiO2-Al2O3 system＋PbO＋CaCl2 were metallic Pb, PbCl, PbCl2, and FeCl2, at the experimental temperature range. The experimental results show that the mole ratio of vaporized Cl in lead chlorides to vaporized Pb, simply expressed as Cl/Pb decreases with increasing temperature. The larger Cl/Pb means a larger ratio of gaseous PbCl2, since metallic Pb and PbCl vapors are formed in a similar reduction atmosphere. The evaporation is initially rapid and becomes steady after holding for 10 min. Gaseous PbCl2 is mainly formed during the heating period, and at the holding stage, it reacts with FeO to produce gaseous FeCl2 With regard to slag composition, FeO content and basicity significantly affect the evaporation of lead. High FeO content and high basicity promotes the formation of metallic Pb and PbCI, whereas, it prohibits PbCl2 evaporation.
基金supported by the National Basic Research Program (973) of China (No. 2011CB706501)the Fundamental Research Funds for the Central Universities (No. 1A4000172210101[67]),China
文摘The volume of fluid(VOF) formulation is applied to model the combustion process of a single droplet in a hightemperature convective air free stream environment.The calculations solve the flow field for both phases,and consider the droplet deformation based on an axisymmetrical model.The chemical reaction is modeled with one-step finite-rate mechanism and the thermo-physical properties for the gas mixture are species and temperature dependence.A mass transfer model applicable to the VOF calculations due to vaporization of the liquid phases is developed in consideration with the fluctuation of the liquid surface.The model is validated by examining the burning rate constants at different convective air temperatures,which accord well with experimental data of previous studies.Other phenomena from the simulations,such as the transient history of droplet deformation and flame structure,are also qualitatively accordant with the descriptions of other numerical results.However,a different droplet deformation mechanism for the low Reynolds number is explained compared with that for the high Reynolds number.The calculations verified the feasibility of the VOF computational fluid dynamics(CFD) formulation as well as the mass transfer model due to vaporization.
文摘To investigate the factors that influence treatment satisfaction after high-power potassium-titanyl-phosphate （KTP） laser vaporization of the prostate, we compared the characteristics between patients who were satisfied and those who were not satisfied. In all, 97 patients aged between 53-82 years （median age 67 years） underwent high-power KTP laser vaporization of the prostate for lower urinary tract symptoms due to benign prostatic hyperplasia. At 12 months postoperatively, 60 patients were satisfied with the treatment, whereas 37 were dissatisfied. Although there were no differences in International Prostate Symptom Score （IPSS） values at baseline, the satisfied group scored better in total IPSS at 1, 3, 6, and 12 months postoperatively （P 〈 0.05）. At baseline, the maximum flow rate （Qmax） was lower in the dissatisfied group and remained low throughout the follow-up period, with the exception of 1 month postoperatively （P 〈 0.05）, compared with the satisfied group. There were no differences in other objective data between the two groups, including post-void residual and the number of voids based on the frequency-volume charts. In a multivariate model, a higher bladder contractility index was associated with a greater likelihood of treatment satisfaction 12 months after high-power KTP laser vaporization （odds ratio 1.024, 95% confidence interval 1.001-1.048, P 〈 0.05）. Patients who were not satisfied following the surgery had a smaller improvement in subjective symptoms and Qmax. In addition, our findings suggest that the relative risk of treatment dissatisfaction following high-power KTP laser vaporization was increased in patients with weak detrusor contractility.
文摘A method for determination of trace rare earth elements in biological sample by ICP-AES with tungsten-spiral electrothermal vaporization(TETV-ICP-AES)sampling has been developed in this work. Several influencing factors including desolvation and vaporization parameters,carrier gas flow rate and ma- trix effect were investigated in detail.Under optimal experimental conditions,the detection limits for La,Nd, Gd,Dy,Ho,Yb,Lu and Y were obtained in the range of 10^(-9)～10^(-11) g,and they are comparable to and,in most instances,better than those for the GFAAS and conventional pneumatic nebulisation-ICP-AES.The precision(RSD)obtained for this method is less than 6%.
文摘The past literature on the use of vegetable oils as fuel in diesel engine revealed that utilizing vegetable oil fuels in diesel engines may require property changes in the oil or perhaps, some minor engine modifications or operating changes. This study was conducted to search for the effect of atmospheric oxygen on the puffing and bursting phenomena that occur during vegetable oils droplet vaporization process in their use as fuel in diesel engine. The fiber-suspended droplet technique was used, and the normalized square droplet diameter as well as the temperature evolution vicinity the droplet was analyzed. The results show that puffing and bursting phenomena highly depend on oxygen. In presence of atmospheric oxygen, there is an increase of the puffing and bursting intensity and therefore the evaporation rate of the vegetable oil droplets, but in an inert environment or when the environment is oxygen-depleted puffing and bursting phenomena disappearing and make place of a series of explosions with lower magnitude. The lack of oxygen reduces the thermal degradation, polymerization and oxidation reactions and consequently the vaporization rate of vegetable oils droplets;and could therefore lead to the formation of deposits in the form of polymers. This is unsuitable for their use as a fuel in diesel engines. It can also be concluded that atmospheric oxygen has some positive effects on engine performance and emissions when operating with vegetable oil. These results help to address the challenge for the use of alternative fuels such as non-edible vegetable oils.
文摘The bis(N-ethyl-5-methylsalicylaldimine)nickel(II) [Ni(5-me-saletN)2] complex was synthesized and characterized by elemental analyses, FT-IR, TG-DTA, mass spectrometry and vapour pressure measurement studies. The TG curve of the complex showed a single-step weight loss commencing from 490 K to nil residue at 600 K, without competing fragmentation step. The non-isothermal vaporization activation energy value determined by Coats-Redfern method yielded the value of 93.5 ± 7 kJmol–1. The dynamic TG run proved the complex to be completely volatile. And the equilibrium vapour pressure of the complex over the temperature range of 421 - 524 K, determined by the TG-based transpiration technique yielded the value of 94.2 ± 1.2 kJmol–1 for its standard enthalpy of vaporization . The entropy of vaporization was calculated from the intercept and found to be 249.4 ± 2.6 Jmol–1•K–1.
基金supported by the National Natural Science Foundation of China.
文摘A new method for direct determination of lanthanum in solid biological materials by fluorination electrothermal vaporization ICP-AES technique with polytetrafluoroethylene(PTFE)disperser as a fluorination agent has been described.The effect of particle size on the signal intensity of La has been investigated.The vaporization behaviour of lanthanum and the main factors affecting fluorinating vaporization have been observed.Under optimum experimental conditions,the detection limit of La to this method is 2.0 ng/ml,and the RSD is 4.5%.The proposed method has been applied to determining directly trace lanthanum in solid biological standard reference materials without any chemical pretreatment,and the determined values are in good agreement with the certified ones.
基金financially supported by the National ‘‘863’’ Project (Grant No. 2012AA0611401)the program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-JC103)
文摘Three series of laboratory vaporization experiments were conducted to investigate the carbon isotope fractionation of low molecular weight hydrocarbons（LMWHs）during their progressive vaporization.In addition to the analysis of a synthetic oil mixture,individual compounds were also studied either as pure single phases or mixed with soil.This allowed influences of mixing effects and diffusion though soil on the fractionation to be elucidated.The LMWHs volatilized in two broad behavior patterns that depended on their molecular weight and boiling point.Vaporization significantly enriched the ^13C present in the remaining components of the C6–C9 fraction,indicating that the vaporization is mainly kinetically controlled;the observed variations could be described with a Rayleigh fractionation model.In contrast,the heavier compounds（n-C10–n-C12）showed less mass loss and almost no significant isotopic fractionation during vaporization,indicating that the isotope characteristics remained sufficiently constant for these hydrocarbons to be used to identify the source of an oil sample,e.g.,the specific oil field or the origin of a spill.Furthermore,comparative studies suggested that matrix effects should be considered when the carbon isotope ratios of hydrocarbons are applied in the field.
文摘According to graph theory method, new method is proposed for the prediction or vaporization heat at normal boiling point of paraffins with moleeular,atructure, and it is compared with other methods. We predict the. vaporization heat at normal boiling point for 57 different paraffins, and that is compared with experimental data, its overall, absolute average deviation is 0.61%. The result is,superior to other methods.
文摘Objectives:To compare the depth of thermal necrosis after use of bipolar resection and vaporization technique comparing intra-individually bipolar loop and bipolar button electrodes.Methods:Transurethral resection and vaporization of the prostate was performed in 55 male patients(260 specimens in total).In a standardized procedure,a bipolar resection loop was used for resection,and a bipolar button electrode was used for vaporization.Both electrodes were applied in each patient,either in the left or in the right lateral lobe.The depth of necrotic zones in the resected or vaporized tissue of each patient was measured in a standardized way by light microscopy.Results:The mean depth with standard deviation of thermal injury caused by the loop electrode was 0.0495±0.0274 mm.The vaporization electrode caused a mean thermal depth with standard deviation of 0.0477±0.0276 mm.The mean difference of necrosis zone depths between the two types of electrodes(PlasmaButtoneresection loop)was 0.0018 mm(p=0.691).Conclusion:For the first time,we present directly measured values of the absolute necrosis zone depth after application of plasma in the transurethral treatment of benign prostatic hyperplasia.The measured values were lower than in all other transurethral procedures.Standardized procedures of measurement and evaluation allow a statistically significant statement that the low necrosis depth in bipolar procedures is independent of the applied electrodes.
基金supported by a grant from "The 11th Five-year Plan of Scientific Research" of People’s Liberation Army of China (No. 06MA297)
文摘In this study, the vaporization ratio of the 2-μm laser in the prostatic tissue with benign prostatic hyperplasia was examined in vitro, to explore a technique to estimate the clearance rate of prostatic tissue during the transurethral vaporesection of the prostate. A total of 9 fresh prostatic tissue specimens were obtained by open surgery and the wet weight of the prostatic tissue were measured immediately after the sample collection. Under the simulated conditions of transurethral vaporesection of the prostate by 2-μm laser, each prostate gland was completely vaporesected into fragments with a diameter of less than 1.0 cm in vitro tissue were collected and measured. Then After the vaporesection, the whole fragments of prostatic the lost weight of prostatic tissue, the weight of the collected prostatic tissue and the ratio of the lost weight of prostatic tissue to the wet weight of the prostate glandular organ specimen were calculated. The correlation between the weight of collected prostatic tissue and the weight of the whole glandular organ was analyzed. All the experimental procedures were carried out by one operator. Wet weight of the prostatic gland specimen and the weight of the harvested prostatic tissues after the procedure were recorded. With respect to the wet weight of prostate gland specimen, the percentage of the weight of collected prostatic tissue was （34.45±1.51） %, and the percentage of the lost weight of prostatic tissue was （65.55±1.51）%. Satisfactory linear relationship was observed between the weight of collected prostatic tissue and the wet weight of prostate gland specimen [y=3.245x=6.475 （t=15.097, P=0.000）]. It is concluded that under the simulated conditions of transurethral vaporesection of the prostate by 2-μm laser, the vaporization ratio of prostatic tissue can be calculated on the basis of the weight of collected prostatic tissue, and thereby the clearance of prostatic tissue during the formal operation by 2-μm laser could be quantitatively determined.
