Determination of Latent Heats of Vaporization and Fusion

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.

Experimental Investigation on Condensate Revaporization During Gas Injection Development in Fractured Gas Condensate Reservoirs

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.

Thermal behaviors and heavy metal vaporization of phosphatized tannery sludge in incineration process

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...

Evaluation of greenlight photoselective vaporization of the prostate for the treatment of high-risk patients with benign prostatic hyperplasia

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.

Vaporization behavior of lead from the FeO-CaO-SiO_2-Al_2O_3 slag system

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.

Preliminary Study on the Vaporization Ratio of the Slurry in the Residue Fluid Catalytic Cracking Disengager

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.

Vapor Pressure, Vaporization Enthalpy, Standard Enthalpy of Formation and Standard Entropy of n-Butyl Carbamate

The vapor pressures of n-butyl carbamate were measured in the temperature range from 372.37 K to 479.27 K and fitted with Antoine equation. The compressibility factor of the vapor was calculated with the Virial equation and the second virial coefficient was determined by the Vetere model. Then the standard enthalpy of vaporization for n-butyl carbamate was estimated. The heat capacity was measured for the solid state(299.39–324.2 K) and liquid state(336.65–453.21 K) by means of adiabatic calorimeter. The standard enthalpy of formation ΔfH[crystal(cr),298.15 K] and standard entropy S(crystal,298.15 K) of the substance were calculated on the basis of the gas-phase standard enthalpy of formation ΔfH(g,298.15 K)and gas-phase standard entropy S(g,298.15 K), which were estimated by the Benson method. The results are acceptable, validated by a thermochemical cycle.

Treatment satisfaction after I year high-power potassiumtitanyl-phosphate photoselective vaporization of the prostate

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.

ELECTRO-THERMAL EFFECTS AND DEFORMATION RESPONSE OF CARBON FIBER MAT CEMENT BEAMS

A carbon fiber mat is a sheet composed of intercrossing short carbon fibers,which has more stable and lower electrical resistivity compared with dispersed short carbon fiber mixed in cement.Thereby carbon fiber mat cement could exhibit obvious electro-thermal effect.When electrified,the temperature of composite structures made up of cement mortar and carbon fiber mat will rise rapidly.If the temperature field is not uniform,temperature difference will cause structures to deform,which can be used to adjust the deformation of structures.The temperature field and deformation response driven by the electro-thermal effects of a type of carbon fiber mat cement beams are studied.Firstly,the temperature and deformation responses are studied using theories of thermal conduction and elasticity.Secondly,experimental results are given to verify the theoretical solution.These two parts lay the foundation for temperature and deformation adjustment.

Determination of Trace Rare Earth Elements in Biological Samples by ICP-AES with Tungsten-spiral Electrothermal Vaporization Sampling

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%.

Model of Polysilicon Electro-thermal Micro Actuator and Research of Micro Scale Effect

A type of crank beam electro-thermal micro actuator was prescribed. Mechanical model of the actuator was established, and the static characteristic was analyzed.Comparing the theoretical analysis with experimental data, it is found that the thermodynamic character of material in micro actuator has a different variable regularity contrasted to that used in macro scale machines. It is the micro scale effect that results in the deviation between the simulating result and experimental results. The thermodynamic expression of polysilicon, which was fitted by means of the experimental data concerned, was used to modify the mechanical model. The modified model, in which the micro scale thermodynamic characteristic was considered, was more reasonable and could make the optimal design and control strategies analyzing the straight-line micro actuator more feasible.

Microstructure and wear resistance of electro-thermal explosion sprayed stellite coating used for remanufacturing

Electro-thermal explosion directional spraying was used to prepare the stellite coating on substrate of the AISI 1045 steel. The morphologies of cross-section and worn scar, porosity, distribution of elements, micro- hardness and wear resistance of the coating were determined by means of SEM, EDAX, micro-hardness tester and sliding wear tester. Because of the compact construction, good bonding and high hardness, the coating is characterized by good wear resistance. The results show that the mainly failure mode of the stellite coating is micro- plowing.

STUDY ON THE THERAPEUTIC EFFECT AND MECHANISMS OF ELECTRO-THERMAL NEEDLING FOR TREATMENT OF VULVAL LEUKOPLASIA

In the present paper,444 patients with vulvar leukoplasia were treated by selectingacupoints in the local area and along the meridian plus Qugu（CV 2）and Huiyin（CV 1）and usingelectro-thermal needling.The total effective rate was up to 100.0％and the cure rate 87.3％.Theelectro-thermal effect directly acted on the affected area but strengthened the immunologic function ofthe whole body and raised the content of serum copper.

The Effect of Atmospheric Oxygen on the Puffing and Bursting Phenomena during Vegetable Oils Droplets Vaporization Process for Their Use as Biofuel in Diesel Engine

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.

Sintering process as relevant parameter for Bi_2O_3 vaporization from ZnO-Bi_2O_3-based varistor ceramics

The relationship between sintering process and vaporization of the Bi2O3 in ZnO-Bi2O3-based varistor ceramics was investigated.The phase and microstructure evolution during the sintering process were examined.The results show that the higher the sintering temperature or the longer the sintering time is,the more the Bi2O3 is volatilized.The heating rate has little effects on the Bi2O3 volatilized in ZnO-Bi2O3-based varistor ceramics.This is in accordance with the relative X-ray diffraction peak area ratio analysis.The results also show that the sintering temperature has the greatest impact on the vaporization of the Bi2O3,then followed by sintering time,and the effect of the heating rate is the minimum.

ELECTRO-THERMAL MOXIBUSTION ON ACUPOINTS FOR TREATMENT OF 98 CASES OF SCIATICA

98 patients with sciatica are treated.by stimubting acupoints using a self-made electro-thermal moxibustion instrument.Results show that 82 cases arecured,8 improved and 5 effective,with the total effective rate of 96.9％.The temperature relesed from this instrument is adjustable.The electro-thermal moxibustion therapy is short in treatment duration and rapid in taking effect.Ithas no needling-induced pain and no side-effects,and is accepted preferably by patients.

STUDY OF EXPLOSIVE VAPORIZATION OF LD11R ALUMINUMALLOY DURING ELECTRON BEAM DEEP PENETRATION

High-power-density electron beam with single pulse was performed on the LD11R aluminum alloy. The electron beam was focused on three typical positions. For each case, the distribution of the solute concentration at the cavity bottom solid-liquid interface was investigated by using the 'rapidly fixing' method. The interaction of the beam and solute atoms was analyzed. A new mechanism of explosive vaporization was proposed based on the present results. The occurrence of this explosive vaporization source was discussed.

High-temperature corrosion-resistance performance of electro-thermal explosion spraying coating

As a new spraying technology used in the remanufacturing engineering, electro-thermal explosion spraying holds a lot of advantages. Electro-thermal explosion spraying coating aliquation phenomena are reduced and non-crystal, micro-crystal and millimicron-crystal and other microstructure are formed. The corrosion-resistance ability of electro-thermal explosion spraying coating in high temperature environment was surveyed respectively. SEM equipped with EDS was employed to analyze the microstructure of spraying coating before and after corrosion. The corrosion-resistance mechanism of the spraying coating was discussed.

Determination of Cd,Pb and Sr by Microwave Plasma Torch Atomic Emision Spectrometry Using an Electrothermal Vaporization Sample Introduction System

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In Vitro Study on the Vaporization Ratio of 2-μm Laser in Human Prostatic Tissue

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.