Evaluation of direct reading photoionization detector performance under various operational parameters

Background: A hand-held portable direct-reading monitor, including photoionization detector (PID) is renowned for its good sensitivity, considerable dynamic range, and nondestructive vapor detection ability in comparison to the tardy response of the PID in gas chromatography (GC), which its application has been restricted. In this study, the performance of a PID system (MultiRAE Lite) was evaluated as a replacement of GC in the measurement of toluene in a dynamic adsorption system. Methods: The test was done at different relative humidity levels (30%, 50%, and 80%), temperatures (21, 30, 40° C), and toluene concentrations (20, 100, 200, and 400 ppm). Results: The PID achieved 48% of all measurements meeting the comparison criterion. The results showed that the performance of the PID could be altered by the variables. The best performance of the PID was at temperature of 21° C, the relative humidity of 50%, and concentration of 200 ppm with the percentage of readings achieving the criterion of comparison to 58%, 54%, and 52%, respectively. The averages of the PID readings (mean ± SD at 200 ppm= 207.9 ± 8.7) were higher than the reference method measurements averages (mean ± SD at 200 ppm= 203.5 ± 5.8). The regression analysis of the toluene results from the PID and the reference method results indicated that the measurements were significantly correlated (r2 = 0.93). Conclusion: According to the results, the device response is linear. Therefore, the findings are acceptable in adsorption studies. In this way, the measurement of the sample concentration should be performed using the same instrument before and after the reactor in order to calculate the adsorption efficiency.

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High-Sensitivity Micro-Gas Chromatograph–Photoionization Detector for Trace Vapor Detection

ACS Sensors ◽

10.1021/acssensors.1c00482 ◽

2021 ◽

Author(s):

Maxwell Wei-Hao Li ◽

Abhishek Ghosh ◽

Anandram Venkatasubramanian ◽

Ruchi Sharma ◽

Xiaolu Huang ◽

...

Keyword(s):

High Sensitivity ◽

Gas Chromatograph ◽

Vapor Detection ◽

Photoionization Detector

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Performance of a capnodynamic method estimating cardiac output during respiratory failure - before and after lung recruitment

Journal of Clinical Monitoring and Computing ◽

10.1007/s10877-019-00421-w ◽

2019 ◽

Vol 34 (6) ◽

pp. 1199-1207

Author(s):

Thorir Svavar Sigmundsson ◽

Tomas Öhman ◽

Magnus Hallbäck ◽

Eider Redondo ◽

Fernando Suarez Sipmann ◽

...

Keyword(s):

Cardiac Output ◽

Respiratory Failure ◽

Reference Method ◽

Hemodynamic Instability ◽

Lung Lavage ◽

Lung Recruitment ◽

Recruitment Manoeuvre ◽

Percentage Error ◽

Before And After ◽

The Right

AbstractRespiratory failure may cause hemodynamic instability with strain on the right ventricle. The capnodynamic method continuously calculates cardiac output (CO) based on effective pulmonary blood flow (COEPBF) and could provide CO monitoring complementary to mechanical ventilation during surgery and intensive care. The aim of the current study was to evaluate the ability of a revised capnodynamic method, based on short expiratory holds (COEPBFexp), to estimate CO during acute respiratory failure (LI) with high shunt fractions before and after compliance-based lung recruitment. Ten pigs were submitted to lung lavage and subsequent ventilator-induced lung injury. COEPBFexp, without any shunt correction, was compared to a reference method for CO, an ultrasonic flow probe placed around the pulmonary artery trunk (COTS) at (1) baseline in healthy lungs with PEEP 5 cmH2O (HLP5), (2) LI with PEEP 5 cmH2O (LIP5) and (3) LI after lung recruitment and PEEP adjustment (LIPadj). CO changes were enforced during LIP5 and LIPadj to estimate trending. LI resulted in changes in shunt fraction from 0.1 (0.03) to 0.36 (0.1) and restored to 0.09 (0.04) after recruitment manoeuvre. Bias (levels of agreement) and percentage error between COEPBFexp and COTS changed from 0.5 (− 0.5 to 1.5) L/min and 30% at HLP5 to − 0.6 (− 2.3 to 1.1) L/min and 39% during LIP5 and finally 1.1 (− 0.3 to 2.5) L/min and 38% at LIPadj. Concordance during CO changes improved from 87 to 100% after lung recruitment and PEEP adjustment. COEPBFexp could possibly be used for continuous CO monitoring and trending in hemodynamically unstable patients with increased shunt and after recruitment manoeuvre.

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Synthesis of 70K stress protein by human leukocytes: effect of exercise in the heat

Journal of Applied Physiology ◽

10.1152/jappl.1991.70.1.466 ◽

1991 ◽

Vol 70 (1) ◽

pp. 466-471 ◽

Cited By ~ 59

Author(s):

A. J. Ryan ◽

C. V. Gisolfi ◽

P. L. Moseley

Keyword(s):

Protein Synthesis ◽

Relative Humidity ◽

Treadmill Exercise ◽

Stress Protein ◽

Exercise Bout ◽

Time Dependent ◽

Dependent Manner ◽

Human Leukocytes ◽

Before And After

To determine whether reinduction of 70,000-Da (70K) stress protein synthesis could be used as an assay for thermal history and/or cellular levels of 70K stress protein in hyperthermic humans, leukocytes were obtained before and after 2 h of exercise and then incubated at 37 or 41 degrees C. Five healthy males completed 2 h of treadmill exercise consisting of running at 4–6 km/h for 30–45 min followed by 75–90 min of walking up a 2–10% grade. This exercise bout was performed by two subjects in hot (46 degrees C, 15% relative humidity) and by five subjects in cooler (30 degrees C, 40% relative humidity) environmental conditions. Exercise resulting in rectal temperature (Tre) less than 40 degrees C did not alter the amount of 70K stress protein synthesized by leukocytes incubated at 41 degrees C. In contrast, exercise resulting in Tre greater than 40 degrees C reduced the amount of 70K stress protein synthesized by leukocytes incubated at 41 degrees C. A protein immunoblot, probed with an antibody specific for the inducible 72K stress protein, showed that the reduction of 35S-labeled 70K stress protein in these postexercise leukocyte samples occurred without marked elevations of this protein. In vitro incubation of human leukocytes at 40 degrees C for 15–120 min reduced, in a time-dependent manner, the amount of 70K stress protein synthesized during a subsequent 41 degrees C heat stress. This reduction of 70K stress protein synthesis in 41 degrees C-treated leukocytes was abolished when cycloheximide was present during the 40 degrees C preincubation.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effects of Environmental Factors on Concrete Carbonation Depth and Compressive Strength

Materials ◽

10.3390/ma11112167 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2167 ◽

Cited By ~ 25

Author(s):

Ying Chen ◽

Peng Liu ◽

Zhiwu Yu

Keyword(s):

Compressive Strength ◽

Phase Composition ◽

Relative Humidity ◽

Co2 Concentration ◽

Crystal Structure Analysis ◽

Hydration Products ◽

Carbonation Depth ◽

Concrete Carbonation ◽

Before And After ◽

Compressive Strength Of Concrete

The influence of temperature, CO2 concentration and relative humidity on the carbonation depth and compressive strength of concrete was investigated. Meanwhile, phase composition, types of hydration products and microstructure characteristics of samples before and after the carbonation were analyzed by XRD and ESEM. Research results demonstrate that temperature, CO2 concentration and relative humidity influence the carbonation depth and compressive strength of concrete significantly. There is a linear relationship between temperature and carbonation depth, as well as the compressive strength of concrete. CO2 concentration and relative humidity present a power function and a polynomial function with carbonation depth of concrete, respectively. The concrete carbonation depth increases with the increase of relative humidity and reaches the maximum value when the relative humidity is 70%. Significant differences of phase composition, hydration products and microstructure are observed before and after the carbonation. Carbonization products of samples are different with changes of temperatures (10 °C, 20 °C and 30 °C). The result of crystal structure analysis indicates that the carbonation products are mainly polyhedral spherical vaterite and aragonite.

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Factors influencing the Action of Dust Insecticides

Bulletin of Entomological Research ◽

10.1017/s0007485300027474 ◽

1950 ◽

Vol 41 (1) ◽

pp. 1-61 ◽

Cited By ~ 33

Author(s):

W. A. L. David ◽

B. O. C. Gardiner

Keyword(s):

Relative Humidity ◽

Soft Materials ◽

Experimental Procedure ◽

Hard Materials ◽

Dust Clouds ◽

Factors Influencing ◽

Before And After ◽

Sudan Iii ◽

Insecticidal Action ◽

Gain Access

The methods used to investigate the properties of dusts are described and, in a theoretical section, the relevance of the various physical properties to insecticidal action are considered.In order to investigate the effect of toxic and non-toxic dusts on insects the experimental procedure was simplified to eliminate all difficulties associated with the formation of uniform dust clouds and deposits. In problems relating to the adherence of the dusts to insects the actual quantity of dust was measured either by weighing the insects before and after dusting or by dyeing the dust with Sudan III and determining the quantity colorimetrically. The experiments were all conducted under known conditions of temperature and humidity.Non-toxic dusts killed insects by causing them to lose water. Not all non-toxic powders were equally effective when conditioned to the same relative humidity. All were without effect at saturated humidity and became progressively more rapid in action as the humidity at which the test was carried out was decreased (p. 32).The non-toxic dusts caused the insects to lose water by abrading certain areas of the cuticle ; the more extensive the abrasion the more quickly the insects died (p. 27).To be effective as an abrasive the dust must be hard and finely ground and, perhaps also, sharply angular. Thus materials which ranked high in Moh's scale of hardness were in general more effective than soft materials and hard materials became quite ineffective unless they contained material below about 10 μ, diameter. Presumably the coarser materials could not gain access to the articulations, etc., where abrasion usually occurred. This effect can be seen clearly with carborundum powders. Sharply angular glass was more effective than the same powder converted into rounded spheres (pp. 25–31).

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Capacitive and Conductometric type Dual-Mode Relative Humidity Sensor based on 5,10,15,20-tetra phenyl porphyrinato nickel (II) (TPPNi)

10.21203/rs.3.rs-775614/v1 ◽

2021 ◽

Author(s):

Rizwan Akram ◽

Muhammad Yaseen ◽

Zahid Farooq ◽

Ayesha Rauf ◽

Karwan Wasman Qadir ◽

...

Keyword(s):

Relative Humidity ◽

Humidity Sensor ◽

Dynamic Range ◽

Layer Structure ◽

Soret Band ◽

Organic Polymer ◽

Synthesis Process ◽

Microwave Assisted Synthesis ◽

Electrode Gap ◽

Electron Microscopic

Abstract In the present study, TPPNi has been synthesized by using a microwave-assisted synthesis process. The layer structure of the fabricated humidity sensor (Al/TPPNi/Al) consists of pair of planar 120 nm thin Aluminium (Al) electrodes (deposited by thermal evaporation) and ~ 160 nm facile spin-coated solution-processable organic polymer TPPNi as an active layer between the ~ 40 µm electrode gap which was created through shadow mask process. Physical characterization showed that synthesized TPPNi thin films are very well suitable for their application as ambient sensors based on location and width for Soret band from optical characterization, amorphous structure from XRD, and most importantly the porous surface morphology from field emission scanning electron microscopic study. Electrical properties (capacitance and impedance) of sensors were found to be substantially sensitive not only on relative humidity but also on the frequency of the input bias signal. Our findings demonstrate that the TPPNi has higher humidity sensitivity at lower frequencies. The proposed sensor exhibits multimode (capacitive and conductometric) operation with significantly higher sensitivity ~ 146.17 pF/%RH at 500 Hz and 48.23 kΩ/%RH at 1 kHz. The developed Al/TPPNi/Al surface type humidity sensor's much-improved detecting properties along with reasonable dynamic range and response time suggest that it could be effective for continuous humidity monitoring in multi environmental applications.

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Rapid measurement of serum water to assess pseudohyponatremia.

Clinical Chemistry ◽

10.1093/clinchem/32.6.983 ◽

1986 ◽

Vol 32 (6) ◽

pp. 983-986 ◽

Cited By ~ 10

Author(s):

S Faye ◽

R B Payne

Keyword(s):

Electrode System ◽

Diabetic Coma ◽

Lipid Concentration ◽

Selective Electrode ◽

Direct Reading ◽

Rapid Methods ◽

Rapid Measurement ◽

System A ◽

Before And After ◽

Space Occupying Lesion

Abstract Pseudohyponatremia is caused by an increased serum protein or lipid concentration producing a "space-occupying lesion" in serum water. Its presence and magnitude must be assessed in hyponatremic patients with, for example, paraproteinemia or hyperlipemic diabetic coma. In the absence of a direct-reading ion-selective electrode system, a method for measuring the water content of serum is required. We describe two rapid methods for measuring the diffusible water of serum: osmometry before and after dilution and chloride measurement before and after ultrafiltration. Either of these methods allows the true sodium status of a patient's serum to be determined.

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AVALIAÇÃO DA QUALIDADE DE LARANJA PÊRA APÓS ARMAZENAMENTO COM ETILENO

Boletim do Centro de Pesquisa de Processamento de Alimentos ◽

10.5380/cep.v20i2.1261 ◽

2002 ◽

Vol 20 (2) ◽

Author(s):

JORGE JOSÉ DO VALE OLIVEIRA ◽

MARIA CECÍLIA DE FIGUEIREDO TOLEDO ◽

JOSÉ MARIA MONTEIRO SIGRIST ◽

KATUMI YOTSUYANAGI ◽

IVÂNIA ATHIÉ

Keyword(s):

Relative Humidity ◽

Storage Period ◽

Quality Parameters ◽

Chemical Parameters ◽

Physical Chemical ◽

Before And After ◽

Orange Fruit

Laranjas da variedade Pêra, previamente armazenadas durante três dias, com e sem etileno foram pulverizadas com Imazalil, Tiabendazol e a mistura de ambos, formulados ou não com cera. Em seguida, foram mantidas durante 25 dias a 4ºC ± 2ºC/90% ± 5% de umidade relativa, sendo avaliados parâmetros de qualidade da laranja, antes e ao final do armazenamento. Com exceção do atributo cor não ocorreram diferenças estatisticamente significativas nos demais parâmetros químicos e físico-químicos, independente da exposição ao etileno. O etileno foi eficiente no desverdecimento de laranjas, sem comprometer seus atributos de qualidade, e o tratamento posterior com cera contribuiu para manter inalterado o padrão de cor obtido. EVALUATION OF THE QUALITY OF PÊRA ORANGE FRUIT AFTER STORAGE IN ETHYLENE Abstract Oranges of the variety Pêra previously stored during three days with and without ethylene were sprayed with Imazalil, Thiabendazole and a mixture of both fungicides, formulated with and without wax. Following this treatment the fruits were stored during 25 days at 4ºC ± 2ºC / 90% ± 5% of relative humidity, parameters related to orange quality were evaluated before and after the storage period. With exception of the attribute color, no significative statistically differences were observed in the chemical and physical-chemical parameters, independent of the exposure to ethylene. The ethylene was effective for the degreening of orange with no action on the quality parameters. The further treatment with wax contributed to maintain the pattern of colour unchanged.

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Sonar using chaotic sounding signals

MORSKIE INTELLEKTUAL`NYE TEHNOLOGII ◽

10.37220/mit.2021.51.1.005 ◽

2021 ◽

pp. 36-40

Author(s):

Ш.С. Фахми ◽

С.В. Горяинов ◽

А.В. Калач

Keyword(s):

Signal To Noise Ratio ◽

Water Environment ◽

Deterministic Chaos ◽

Reference Method ◽

Current Approach ◽

Arbitrary System ◽

Simulated Environment ◽

Before And After ◽

Probing Signal ◽

The Stability

В данной работе рассматривается подход к генерации зондирующего сигнала гидролокатора, основанный на применении систем с детерминированным хаосом. Рассматриваются актуальные подход к генерации зондирующего сигнала при проектировании гидролокаторов. Приводится описание полуявного метода Верле для произвольной системы обыкновенных дифференциальных уравнений. Приводится методология построения композиционных схем для получения методов численного интегрирования произвольного порядка на основе симметричного опорного метода. Приводятся результаты компьютерного моделирования форм различных сигналов до и после прохождения через имитацию водной среды. Приводятся экспериментальные результаты оценки погрешности в распознавании сигнала при различных значениях соотношения сигнал/шум имитируемой среды, проводится сравнительная оценка в значениях, полученных с использованием различных сигналов. Приводятся результаты оценки устойчивости исследуемых сигналов к перекрёстным помехам, проведена сравнительная оценка рассмотренных подходов к генерации зондирующего сигнала. Сделаны выводы о применимости хаотических сигналов в качестве зондирующих In this paper, we consider an approach to generating a sonar sounding signal based on the use of systems with deterministic chaos. The current approach to the generation of sounding singal in the design of sonar is considered. The semi-implicit Wehrle method for an arbitrary system of ordinary differential equations is described. A methodology for constructing composite schemes for obtaining methods of numerical integration of arbitrary order based on the symmetric reference method is presented. The results of computer simulation of the forms of various signals before and after passing through the simulated water environment are presented. Experimental results of estimating the error in signal recognition at different values of the signal-to-noise ratio of the simulated environment are presented, and a comparative assessment is made in the values obtained using different signals. The results of the evaluation of the stability of the studied signals to crosstalk are presented, and a comparative evaluation of the considered approaches to the generation of the probing signal is carried out. Conclusions are drawn about the applicability of chaotic signals as probing signals

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Validated Analytical Spectrofluorimetric Method for Quantitation of Diphenhydramine HCl in Commercial Dosage Forms

Journal of new developments in Chemistry ◽

10.14302/issn.2377-2549.jndc-18-2220 ◽

2018 ◽

Vol 1 (4) ◽

pp. 12-26

Author(s):

Syed Najmul Hejaz Azmi ◽

Aisha Al-Mahroqi ◽

Khoula Al-Mamari ◽

Shaima Al-Shukaili

Keyword(s):

Dynamic Range ◽

Fluorescence Emission ◽

Reference Method ◽

Pharmaceutical Formulations ◽

Ion Pair ◽

Ratio Method ◽

Eosin Y ◽

Stoichiometric Ratio ◽

Buffer Solution

Diphenhydramine HClis a weakly fluorescent drug having tertiary amine group forming ion pair complex with eosin Y in dichloromethane at pH 5 in disodium hydrogen phosphate-citric acid buffer solution. The complex formation was the basis for the development of new analytical method for determination of active diphenhydramine in pharmaceutical formulations. The stoichiometric ratio between diphenhydramine and eosin Y was studied by mole ratio method and found to be 2:1. The ion-pair complex showed maximum fluorescence emission intensity at 554 nm with excitation at 259 nm. The linear dynamic range was obtained in the concentration range of 2-22 µg mL-1 with a linear equation of FI = 0.361 + 13.675 C. The apparent Gibb’s free energy (ΔGº) was calculated and found to be -80.783 KJ mol-1, confirmed the feasibility of the reaction. The proposed method was successfully applied to the determination of diphenhydramine HCl in pharmaceutical formulations and in good agreement with the reference method.

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