Simultaneous thermal and contraction/expansion curves analysis for solidification control of cast irons

The first part of the paper summarizes the performance of two mould devices,illustrating by representative shrinkage tendency results in ductile cast iron as affected by mould rigidity(green and furan resin sand moulds)and inoculant type(FeSi-based alloys).Less rigid green sand moulds encourage the formation of contraction defects,not only because of the high initial expansion values(ε(di))(max),but also because of the increased solidification undercooling.A high inoculation efficiency means not only lowering the carbides formation sensitivity and increasing the nodule count,but also a prolonged graphitization through to the end of the eutectic freezing,as observed by the high population of small late forming nodules,which leads to minimizing the tendency for shrinkage.The second part of the paper illustrates an application of this equipment to commercial foundry use.It conducts thermal analysis and volume change measurements in a single ceramic cup with cast iron quality as a variable.La-bearing FeSi inoculant appears to be more effective than RE(Rare Earth)-FeSi alloy in FeSiMgCa treated irons(no RE),in terms of reducing eutectic undercooling and(ε(di))(max),favourable for lower sensitivity to shrinkage formation.Experiments also compared solidification patterns for white[WI],grey[GI]and ductile[DI]irons,to correlate the most important events between the cooling curves and contraction curves,to evaluate the sensitivity to shrinkage formation.All of the irons have similar values for initial expansion up to the start of eutectic freezing,but,after that,the graphite formation promotes expansion(more than 5 times for nodular graphite),resulting in a difference in maximum expansion(2 times higher for DI).The graphitic expansion has two contrary effects.Increased graphitic expansion(force)leads to a higher shrinkage sensitivity during the first part of the eutectic reaction,but also to a decrease of shrinkage at the end of solidification,due to forcing the last liquid iron to occupy the previous formed cavities.Consequently,strong graphitization process promotion at the end of solidification favours the castings'soundness.

Simultaneous Spectrophotometric Determination of Four Components including Acetaminophen by Taget Factor Analysis

UV Spectrophotometric Target Factor Analysis （TFA） was used for the simultaneous determination of four components （acetaminophen, guuaifenesin, caffeine, Chlorphenamine maleate） in cough syrup. The computer Frogram of TFA is based on VC＋＋ language. The difficulty of overlapping of absorption spectra of four compounds was overcome by this procedure. The experimental results show that the average recovery of each component is all in the range from 98.9% to 106.8% and each component obtains satisfactory results without any pre-separation.

Analysis of Difficulties in Simultaneous Interpreting(SI) from a Psycho-linguistic Perspective

Nowadays,simultaneous interpreting(SI) plays a prominent role in global communications,especially for important international affairs.This kind of interpretation delivers information in an instantaneous way without wasting extra time for language processing.Performing well in SI requires long-time training and abundant experience.Making a comprehensive categorization and analysis on the difficulties in SI on the basis of psycho-linguistic theories are the key points.Due to the distinctive features of these difficulties,corresponding suggestions will be offered to improve the efficiency in SI training and to level up the performance of SI interpreters.

Analysis of Magnetic Field Inducted in Brain by Multi-Channel Magnetic Stimulation

Multi-channel magnetic stimulation is an efficient method to improve the conventional magnetic stimulation. A multi-channel magnetic brain stimulator was developed and the distribution of magnetic field was calculated by finite-element analysis software-ANSYS. The results show that when five coils work simultaneously, the area where the magnetic flux density is larger than 0.01 T would expand to almost the whole brain region, and the magnetic stimulation depth would be improved. Experiments were performed on ten subjects (mean age 25) using the stimulator, and the EEG power spectrums before and after stimulation were analyzed. The experimental results show that the beta component of EEG obviously increases after magnetic stimulation, and the effect is more obvious by using more coils simultaneously because of the deeper stimulation.

Non-isothermal kinetic analysis of thermal dehydration of La_2(CO_3)_3·3.4H_2O in air

The single phase La2（CO3）3·3.4H2 O was synthesized by hydrothermal method. The thermal decomposition and intermediates and final solid products of La2（CO3）3·3.4H2O from 30 to 1000 °C were characterized by XRD, FTIR and DTA-TG. The kinetics of dehydration of La2（CO3）3·3.4H2O in the temperature range of 30-366 °C was investigated under non-isothermal conditions. Flynn-Wall-Ozawa and Friedman isoconversion methods were used to calculate the activation energy and analyze the reaction steps; multivariate non-linear regression program was applied to determine the most probable mechanism and the kinetic parameters. The results show that the thermal dehydration of La2（CO3）3·3.4H2O is a kind of three-step competitive reaction, and controlled by an n-order initial reaction followed by n-order competitive reaction（FnFnFn model）. The activation energy matching with the most probable model is close to value obtained by Friedman method. The fitting curves match the original TG-DTG curves very well.

MOTION ANALYSIS OF TAPER MACHINING USING FOUR-AXIS WEDM MACHINE TOOL

The configuration and the reference frame of the four-axis wire-electric discharge machining （WEDM） machine tool are introduced. Based on the motion analysis of the four-axis WEDM machine tool, an algorithm for controlling the four-axis motion is proposed. The algorithm is applicable to both the invariable and variable taper machining. Motion loci of the machining platform and the wire guiding head are deduced by the algorithm according to the bottom surface locus of the workpiece and the taper angle. The algorithm is used in the CNC system of the four-axis WEDM machine tool and confirmed to be effective.

Simultaneous Quantification of Ibuprofen and Paracetamol in Tablet Formulations Using Transmission Fourier Transform Infrared Spectroscopy

A very simple, non-destructive, inexpensive and green strategy was applied for the simultaneous determination of ibu-profen (IBP) and paracetamol (PC) using transmission Fourier Transform Infrared (FTIR) spectroscopy in tablet formulations for routine quality control laboratories. For the determination of the active pharmaceutical ingredients (API), KBr pellets containing known amount of standards and samples were used for acquisition of the FTIR spectra. The partial least squares (PLS) calibration model was developed using the spectral region from 1781 - 1683 cm-1 for IBP and 1630 - 1530 cm-1 for PC. The excellent coefficients of determination (R2), 0.9999 and 0.9998 were achieved for IBP and PC, respectively. The accuracy of calibration model was also verified through root mean square error of cross validation (RMSECV) which was found to be 0.064. This work clearly shows the capability of transmission FTIR spectroscopy for assessment of exact quantity of API to control the quality of finished products as well as during processing in pharmaceutical industries without involvement of any solvent.

An analysis and evaluation system of pulsed GMAW process based on LabVIEW

A process evaluation system for pulsed gas metal arc welding （GMAW-P） based on the Lab V1EW platform has been developed. This system is comprised of two modules, a simultaneous display module and a data analysis module. Using these modules, the system can not only provide a comprehensive direct viewing display of the welding electric signal and high speed camera photo, but also can analyze the characteristic parameters of the welding process. The results show that the system works properly.

Decoupling Adaptive Sliding Mode Observer Design for Wind Turbines Subject to Simultaneous Faults in Sensors and Actuators

This paper proposes an adaptive sliding mode observer(ASMO)-based approach for wind turbines subject to simultaneous faults in sensors and actuators.The proposed approach enables the simultaneous detection of actuator and sensor faults without the need for any redundant hardware components.Additionally,wind speed variations are considered as unknown disturbances,thus eliminating the need for accurate measurement or estimation.The proposed ASMO enables the accurate estimation and reconstruction of the descriptor states and disturbances.The proposed design implements the principle of separation to enable the use of the nominal controller during faulty conditions.Fault tolerance is achieved by implementing a signal correction scheme to recover the nominal behavior.The performance of the proposed approach is validated using a 4.8 MW wind turbine benchmark model subject to various faults.Monte-Carlo analysis is also carried out to further evaluate the reliability and robustness of the proposed approach in the presence of measurement errors.Simplicity,ease of implementation and the decoupling property are among the positive features of the proposed approach.

Ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry method for the simultaneous determination of itraconazole and hydroxy itraconazole in human plasma

A highly sensitive, selective, and precise ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated for simultaneous quantification of itraconazole and hydroxy itraconazole in human plasma by a single liquid-liquid extraction step. The precursor to product ion transitions of m/z 705.3/392.3, m/z 721.2/408.3 and m/z 708.2/435.4 were used to detect and quantify itraconazole, hydroxy itraconazole and itraconazole-d3 respectively. The lower limit of quantitation was found to be 0.500 ng/mL for itraconazole and 1.00 ng/mL for hydroxy itraconazole. The mean recoveries for itraconazole and hydroxy itraconazole were found to be 100.045% and 100.021%, respectively. This developed method with a chromatographic run time of 2.0 min was successfully applied to a bioequivalence study of 100 mg itraconazole capsule.

Simultaneous Optimization of Incomplete Multi-Response Experiments

This article attempts to develop a simultaneous optimization procedure of several response variables from incomplete multi-response experiments. In incomplete multi-response experiments all the responses (p) are not recorded from all the experimental units (n). Two situations of multi-response experiments considered are (i) on units all the responses are recorded while on units a subset of responses is recorded and (ii) on units all the responses (p) are recorded, on units a subset of responses is recorded and on units the remaining subset of responses is recorded. The procedure of estimation of parameters from linear multi-response models for incomplete multi-response experiments has been developed for both the situations. It has been shown that the parameter estimates are consistent and asymptotically unbiased. Using these parameter estimates, simultaneous optimization of incomplete multi-response experiments is attempted following the generalized distance criterion [1]. For the implementation of these procedures, SAS codes have been developed for both complete (k ≤ 5, p = 5) and incomplete (k ≤ 5, p1 = 2, 3 and p2 = 2, 3, where k is the number of factors) multi-response experiments. The procedure developed is illustrated with the help of a real data set.

Thermodynamic analysis of Na−S−Fe−H_(2)O system for Bayer process

Thermodynamic diagrams of Na−S−Fe−H_(2)O system were constructed to analyze the behavior of sulfur and iron in the Bayer process.After digestion,iron mainly exists as Fe_(3)O_(4) and Fe_(2)O_(3) in red mud,and partial iron transfers into solution as Fe(OH)_(3)^(−),HFeO_(2)^(−),Fe(OH)_(4)^(−)and Fe(OH)_(4)^(2−).The dominant species of sulfur is S^(2−),followed by SO_(4)^(2−),and then SO_(3)^(2−)and S_(2)O_(3)^(2−).The thermodynamic analysis is consistent with the iron and sulfur species distribution in the solution obtained by experiments.When the temperature decreases,sulfur and iron can combine and precipitate.Controlling low potential and reducing temperature are beneficial to removing them from the solution.XRD patterns show that NaFeS_(2)·2H_(2)O,FeS and FeS_(2) widely appear in red mud and precipitates of pyrite and high-sulfur bauxite digestion solution.Thermodynamic analysis can be utilized to guide the simultaneous removal of sulfur and iron in the Bayer process.

Simultaneous Determination of Uranium and Thorium with Standard Dual-addition Method

dual-standard addition method was proposed and the principle of simultaneous determination for a interfering binary mixtures was discussed. The proposed procedure was applied to spectroscopic analyses for the simultaneous determination of uranium and thorium without prior separation. Various molar ratios of uranium/thorium, from 0.5∶1 to 10∶1, can be determined with satisfactory precision and accuracy. Uranium and thorium content in a phosphate ore and simulated sample were determined, the recoveries were 98.4%～102.5% for uranium and 96.8%～102.3% for thorium, the relative standard deviations (R.S.D) were 1.5%～2.3% for uranium and 2.1%～3.1% for thorium.

Non-Isothermal Kinetic Analysis of Thermal Decomposition of the Ca-Bentonite from Santai, China

The thermal decompositions of Ca-bentonites (CaB) from Santai ,Shichuan Province, China over the temperature rage of 30-1100℃ were investigated by simultaneous thermal analyzer. Non-isothermal Kinetic analysis were employed to study the thermal decomposition mechanism by using Netzsch Thermokinetics software. The dependence of the activation energy on conversion degree were evaluated by isoconversional methods. The probably mechanism and the corresponding kinetic parameters were determined by multivariate non-linear regression program.

Simultaneous Determination of Bufadienolides and Qualitative Evaluation for Venenum Bufonis by High Performance Liquid Chromatography

A high performance liquid chromatographic method was used for the simultaneous identification and qualitative evaluation of 12 bufadienolides（resibufogenin, einobufagin, cinobufaginol, arenobufagin, bufalin, bufotalin, gamabufotalin, cinobufotalin, ψ-bufaranogin, desacetylcinobufagin, telocinobufagin and resibufogenol） in Venenum Bufonis. The chromatographic separation was performed on a Dikma C18 analytical column via gradient elution with an aqueous solution of acetonitrile and 0.3% acetic acid at a flow rate of 0.8 mL/min. The method was validated to be acceptable in consideration of linearity（r2 〉 0.9992） and recovery（ranged from 98.9% to 102.0%）. The limits of detection of the bufadienolides were from 0.48 ng for bufalin to 6.00 ng for cinobufotalin. The intra-day and inter-day precisions of the method were evaluated and were less than 3.0%. The method was successfully used to analyze 19 batches of Venenum Bufonis, and the similarity values between batches were calculated by Similarity Evaluation System for Chromatographic Fingerprint of TCM（Version 2004A, Chinese Pharmacopoeia Committee, Beijing）. The results show that the contents of bufadienolides in the medicine and the similarity values based on these bufadienolides varied significantly from batch to batch. This proposed method could be utilized to qualify and control Venenum Bufonis to ensure its safety and efficacy in application.

Simultaneous determination of fourteen components of Gumiganghwal-tang tablet in human plasma by UPLC-ESI-MS/MS and its application to pharmacokinetic study

Gumiganghwal-tang is a traditional herbal medicine widely used for its anti-inflammatory,analgesic,and antipyretic effects.However,the safety and efficacy of its active ingredients based on an in vivo pharmacokinetic(PK)study have yet been investigated.We have established a sensitive and accurate UPLC-ESI-MS/MS method and conducted a PK study on 14 constituents of Gumiganghwal-tang through human plasma analysis.Analytical conditions were optimized according to the physicochemical properties of the 14 compounds to facilitate efficient separation and eliminate overlap or interference between peaks.KINETEX-C18 and Inertsil-C8 columns were used as UPLC stationary phases,and acetonitrile and aqueous formic acid were used as mobile phases.All the analytes were quantified with a triple quadrupole mass spectrometer using electrospray ionization in multiple reaction monitoring mode.The chromatograms of 14 bioactive compounds showed excellent elution and sensitivity,and each peak was selectively separated and quantified without interference with each other or impurities.The established analytical method was based on international guidelines and was successfully used to perform PK studies of 14 herbal ingredients in humans after oral administration with Gumiganghwal-tang tablets.The oral absorption of most active components of Gumiganghwal-tang was relatively rapid and remained considerably long in the body to be quantified in plasma up to 48 h after administration.

Development and Validation of a Method for Simultaneous Determination of Metformin and Saxagliptin in a Formulation by RP-HPLC

A simple, specific, sensitive, precise and accurate reverse phase high performance liquid chromatographic method (RP-HPLC) was developed for the simultaneous analysis of Metformin and Saxagliptin in active pharmaceutical ingredients (APIs) as well as in marketed tablet (combination) dosage forms. The method was achieved on Enable C18 G (250 × 4.6 mm;5 μm particle size) column using 0.05 M KH2PO4 buffer (pH 4.5):Methanol:Acetonitrile (60:20:20 %v/v) as a mobile phase at a flow rate of 0.6 mL/min and by employing UV detection at 220 nm wavelength. The retention time of Metformin and Saxagliptin were found to be 4.38 min and 6.92 min, respectively. The method was validated as per ICH guidelines. The limit of detection (LOD) and limit of quantification (LOQ) of Metformin were found to be 0.112 μg/mL and 0.373 μg/mL, respectively, while those of Saxagliptin were found to be 0.029 μg/mL and 0.096 μg/mL, respectively. The method was found to be rapid, sensitive, linear, specific, accurate, precise and economic for the quality control and stability assays of Metformin and Saxagliptin in marketed tablet dosage forms.

Meta-analysis of efficacy and safety of concurrent or staged bilateral total knee arthroplasty

Objective: To study the safety and efficacy of concurrent bilateral total knee arthroplasty orstaged bilateral total knee replacement using meta-analysis. Methods: The databases of ChinaWanfang, CNKI, PubMed, Cochrane Library, and Web of Science were searched conducted formeta-analysis of the extracted data using Review Manager 5.3 software. Results: ①A total of 18retrospective cohort studies were included, 72 831 patients in the same period group and 103595 patients in the staging group. ②The results of meta showed that in the staging group, theincidence of postoperative cardiac complications[OR= 1.21, 95%CI=(1.10~1.34), P<0.000 1] ,neurological complications[OR=1.67, 95%CI=(1.29~2.16), P<0.000 1], deep vein thrombosis[OR=1.38, 95%CI(1.27~1.50), P<0.000 01], mortality[OR=2.18, 95%CI=(1.67~2.84),P<0.000 01] and perioperative blood loss [OR=246.75, 95%CI=(233.30~260.20)] were lessthan those in the same period group (P<0.000 01);The postoperative deep infection rate in thesame period group [OR=0.61, 95%CI=(0.52~0.71), P<0.000 01] was lower than that in thestaging group;The postoperative superficial infection rate [OR=0.96, 95%CI=(0.66~1.40)],revision rate of joint replacement [OR= 1.04, 95%CI=( 0.96~1.12)], HSS score [OR=0.10,95%CI=(-0.61~0.80), P=0.79] and knee joint activity score [OR=-0.23, 95%CI=(-1.25~0.78)]were not statistically significant between the two groups(P>0.05).Conclusion: Stagingbilateral total knee replacement can more effectively reduce the incidence of perioperativecomplications and reduce the amount of blood transfusion, while concurrent bilateral total kneereplacement can reduce the rate of deep infection. To further compare the efficacy and safety ofconcurrent or staged bilateral total knee arthroplasty, further studies must be conducted in theform of a randomized clinical trial to evaluate the results mentioned in this meta-analysis.

An Analysis of Farming in the Rural Economic Development of West Virginia

Farming is still an important sector in rural economic development of West Virginia where 44% of the population lives in rural areas and 24% of the land is used for farming. While income earnings, education and employment rates are low in rural areas, poverty rates and unemployment are high compared to the urban areas. Thus, in the context of rural development farming is a potential major economic sector where 42% of the people＇s primary occupation is reported as farming. The objective of this study is to identify and estimate the potential impacts of farm employment in rural economic growth of West Virginia. Data from U.S. Bureau of Labor Statistics and U.S Census Bureau for the period of 1993 to 2008 are used for the empirical analysis. A model derived from the three simultaneous equations of Duncan is used for analysis. Three-Stage Least Squares （3SLS） method using the statistical package of STATA is used for estimation. The results concerning simultaneous relationships with population density growth, per capita income growth, and farm employment growth reveal significant importance of farming in rural economic development of West Virginia. Furthermore, the results indicate the positive impacts of population density, number of people with farming as principal occupation, and crop production on rural farming sector.