Sulfur mustard is a chemical agent of high military and terroristic significance. No effective antidote exists, and sulfur mustard can be fairly easily produced in large quantity. Rapid field testing ...of sulfur mustard is highly desirable. Existing analytical devices for its detection are available but can suffer from low selectivity, laborious sample preparation, and/or the need for complex instrumentation. We describe a new kind of test strip for rapid detection of gaseous sulfur mustard that is based on its degradation by the enzyme haloalkane dehalogenase that is accompanied by a change of local pH. This change can be detected using pH indicators contained in the strips whose color changes from blue-green to yellow within 10 min. In addition to visual read-out, we also demonstrate quantitative reflectometric readout by using a conventional digital camera based on red-green-blue data acquisition. Organic haloalkanes, such as 1,2-dichloroethane, have a negligible interfering effect. The visual limit of detection is 20 μg/L, and the one for red-green-blue read-out is as low as 3 μg/L. The assays have good reproducibility ±6% and ±2% for interday assays and intraday assays, respectively. The strips can be stored for at least 6 months without loss of function. They are disposable and can be produced fairly rapidly and at low costs. Hence, they represent a promising tool for in-field detection of sulfur mustard.
Liquid composite molding (LCM) is growing in importance as an alternative to traditional prepreg-autoclave methods for manufacture high-performance composites. The most significant roadblock to ...industry’s implementation of LCM is the usually higher void content compared with prepreg processing. One tool for reducing void levels in LCM involves optimization of flow velocity, which requires models to be developed to describe void formation at a given velocity. To help solve this problem, the following research illustrates the first known method for optical void measurement in situ during infusion in a carbon fiber reinforcement. Similar to previous studies on glass fiber, this work utilizes fluorescent dye and a digital camera to produce sufficient contrast and resolution for image analysis. Visible bubbles are photographed against the opaque carbon fiber background. An automated method of image analysis is outlined, which was used to analyze 230 images for three different flow orientations of a single fabric, producing the highest amount of experimental data seen so far on in situ void measurement. The resulting data identifies a minimum velocity threshold for minimal macro-void formation. The resultant void characterization framework will better enable optimization of LCM processing for high-performance composites based on carbon reinforcements.
•ABE-diesel has a lower sooting tendency compared with butanol-diesel.•Sooting tendency can be ordered as follows: acetone-diesel>butanol-diesel>ethanol–diesel.•Ethanol and butanol enhance the ...ability of ABE to reduce sooting tendency.•The extra acetone weakens the ability of ABE to reduce sooting tendency.
Acetone–Butanol–Ethanol (ABE), the intermediate product in bio-butanol production process using Biological Fermentation Purification technology, has been proposed to blend diesel directly for saving the high energy requirement of separating purity butanol. It is very important to study the sooting tendency of ABE-diesel blends, which determined whether it can be used as a clean alternative fuel. Therefore, in this paper, the smoke point and relationship between flame height and fuel uptake rate for a wide range ratio of ABE (0%, 5%, 10%, 20%, 30%, 50% in volume referred to as D100, ABE5, ABE10, ABE20,ABE30, and ABE50, respectively) were measured using wick-fed burner. Flame heights were captured by a Digital SLR camera and fuel uptake rate were gained from electronic analytical balance. It was observed that flame height versus fuel uptake rate started with a linear relationship, then disjointed points appeared, finally returned linear again. Threshold Sooting Index (TSI) and Oxygen Extended Sooting Index (OESI) calculated from fuel uptake rate and smoke point respectively were used to evaluate the blends’ sooting tendency. ABE-diesel has a lower sooting tendency than butanol-diesel because it owns higher oxygen content and lower carbon content for the same blend ratio. Besides, the contribution of acetone, butanol and ethanol to the intensity of ABE weaken blends’ sooting tendency were tested through increasing their relative concentrations in ABE. Since ethanol and butanol have higher H/C ratio and oxygen content from the view of molecular structure, their content in ABE play a positive role in weakening sooting tendency, while the acetone content in ABE has an opposite effect because of its unsaturation degree.
The original contribution of the present paper is to present a joint theoretical and experimental approach to implement the modulated absorption/emission technique. Two-dimensional fields of soot ...temperature and volume fraction can then be measured simultaneously in a reference steady laminar coflow axis-symmetric non-premixed ethylene flame established over the Santoro burner. The spontaneous flame emission is captured by two CMOS cameras that allow the measurements of the flame emission intensity at two different wavelengths, i.e., 645nm and 785nm in this study. Concomitantly, two 70mm diameter laser beams are used to pass through the flame, enabling the spectral line-of-sight attenuation to be imaged at the two wavelengths by the CMOS sensors. In these spectral ranges, both absorption and emission phenomena are dominated by soot. The local spectral absorption coefficient and spectral emission rate at both wavelengths are obtained by the onion-peeling method with Tikhonov regularization. The soot volume fraction map is inferred from the spectral absorption coefficient field. Mapping soot temperature does not require any model correlating soot volume fraction and local spectral absorption coefficient. Only the measurements of the latter at both wavelengths are required to enable the self-calibration of the technique and infer soot temperature from the ratio of the local spectral emission rates. Thus, the issue of the large discrepancies in the wavelength-dependent soot refractive index reported in the literature does not arise. Within the region of high soot temperatures, the results obtained by the methodology are in good agreement with numerical and experimental data available in the literature. The use of continuous wave lasers as the light sources enables future investigations in flickering flames where the phenomenon of intermittent soot release through the flame tip still needs to be better understood.
Object tracking is a technique for detecting and following the moving object. It can be used to helping security officers to monitor the room that has a large monitoring working area. The aim of ...research is to design the visual system of object tracking by using pan and tilt vision system. The orientation of camera can move in vertically and horizontally path. Visualization program for this project is consist of motion detection, edge detection and center of mass. The detected object position can be used for controlling the pan and tilt at mechanical system which is mounted on the camera to track the moving object. The results of research show the design of object tracking can detecting and following walking human with an ideal distance of 6 meters and directional angular shift is 5 degrees on the visual resolution of 360 × 240 pixels
•Spray characteristics of four aviation fuels were compared.•A higher viscosity diminishes the centrifugal force and increases the hydraulic resistance.•Both Pinj and ν significantly affect the spray ...development and structure.•A higher Pinj and lower ν shortened the breakup length leading to smaller droplets.•The distribution of the diameter showed a broader range at higher viscosity values.•SMD was correlated with fuel physical properties.
With advances in the fuel spray field, much attention has been paid to the atomization characteristics of aviation fuels. The physical properties of fuels play a vital role in their resulting spray structure and spatial distribution of droplets. These characteristics are becoming more important for choosing alternative fuels for optimal performance in next-generation gas turbines. The current study experimentally investigated the atomization quality and spray structure of aviation fuels with different viscosities sprayed through a pressure swirl-type nozzle by employing laser diagnostics. A set of CCD cameras synchronized to the Nd:YAG laser characterized the spray structure, and the size and velocity of the drops were quantified by the phase Doppler technique. The fuels were tested under various temperature and injection pressure conditions. An alteration in both the injection pressure and the physical properties of the fuel were found to significantly dominate the spray structure and atomization quality. The transitional development of hollow-conical sprays was shown to require a sufficient amount of swirl intensity, characterized by their physical properties and injection pressure. Fuels with a lower viscosity were experimentally found to generate well-developed hollow-conical sprays with finer drops, wide distribution in size, and higher velocity components, which are recognized as ideal spray properties in the combustion field.
Fear and anxiety due to severe labor pains could also lead to prolonged labor. The efforts made to accelerate the second stage labor process are by providing emotional support with the support of a ...labor camera. The mother is allowed to observe the development state of her baby's head through video on a tablet or laptop screen. Furthermore, the mother's emotional level becomes more provoked and motivated to strain the labor process faster. This study aims to determine the effect of the labor cameras on the second state duration in primiparous. The design of this study was a posttest-only control group design experiment with a total sample of 30 primiparous of the second stage at independent midwife practice in Bengkulu city in November–December 2020. Each group consisted of 15 for treatment (with labor cameras) and 15 for control (without labor cameras)—the assessment of the labor duration by counting the labor time in seconds during the second state. The statistical results using the t test and chi-square test analysis showed that the intervention group's labor duration (1,393.3 seconds) was shorter than the control group's (2,340.6 seconds). The mean difference in the delivery time was 947.3 seconds or 15.7 minutes faster in the intervention group than in the control group. In conclusion, using a labor camera on the labor duration of the second stage in primiparous mothers is an effect of using a labor camera. PENGARUH KAMERA PERSALINAN TERHADAP DURASI PERSALINAN KALA II PADA PRIMIPARARasa takut dan cemas akibat nyeri persalinan yang berat juga dapat menyebabkan partus lama. Salah satu upaya yang dilakukan untuk mempercepat proses kala II persalinan adalah memberikan dukungan emosional dengan bantuan kamera persalinan. Ibu diberi kesempatan untuk melihat perkembangan pengeluaran kepala bayinya melalui video pada layar tablet atau laptop sehingga tingkat emosional ibu menjadi lebih terbangun dan termotivasi untuk mempercepat proses persalinan. Penelitian ini bertujuan mengetahui pengaruh kamera persalinan terhadap durasi persalinan kala II pada primipara. Desain penelitian adalah eksperimen posttest-only control group design dengan jumlah sampel 30 primipara kala II di bidan praktik mandiri Kota Bengkulu pada November–Desember 2020. Tiap-tiap kelompok berjumlah 15 untuk kelompok perlakuan (menggunakan kamera persalinan) dan 15 untuk kontrol (tidak menggunakan kamera persalinan). Penilaian durasi persalinan dengan menghitung detik selama kala II berlangsung. Pengujian statistik menggunakan analisis uji t dan uji chi-square menunjukkan bahwa durasi persalinan kelompok perlakuan (1.393,3 detik) lebih singkat daripada kelompok kontrol (2.340,6 detik). Selisih perbedaan waktu persalinan rerata selama 947,3 detik atau 15,7 menit lebih cepat pada kelompok intervensi dibanding dengan kelompok kontrol. Simpulan, terdapat pengaruh penggunaan kamera persalinan terhadap durasi persalinan kala II pada ibu primipara.
The integration of plasmonic nanoparticles into biosensors has the potential to increase the sensitivity and dynamic range of detection, through the use of single nanoparticle assays. The analysis ...of the localized surface plasmon resonance (LSPR) of plasmonic nanoparticles has allowed the limit of detection of biosensors to move towards single molecules. However, due to complex equipment or slow analysis times, these technologies have not been implemented for point-of-care detection. Herein, we demonstrate an advancement in LSPR analysis by presenting a technique, which utilizes an inexpensive CMOS-equipped digital camera and a dark-field microscope, that can analyse the λmax of over several thousand gold nanospheres in less than a second, without the use of a spectrometer. This improves the throughput of single particle spectral analysis by enabling more nanoparticles to be probed and in a much shorter time. This technique has been demonstrated through the detection of interleukin-6 through a core-satellite binding assay. We anticipate that this technique will aid in the development of high-throughput, multiplexed and point-of-care single nanoparticle biosensors.
•New approach using a consumer-grade digital camera for single particle analysis.•Improved throughput for conducting single nanoparticles analysis (300x faster).•Detected 4.76 nM of IL-6 as a proof-of-concept for this analytical method.
Dual-fuel combustion strategies combining a premixed charge of natural gas and a pilot injection of diesel fuel offer the potential to reduce CO₂ emissions as a result of the high Hydrogen/Carbon ...(H/C) ratio of methane gas. Moreover, the high octane number of methane means that dual-fuel combustion strategies can be employed on compression ignition engines without the need to vary the engine compression ratio, thereby significantly reducing the cost of engine hardware modifications. The aim of this investigation is to explore the fundamental combustion phenomena occurring when methane is ignited with a pilot injection of diesel fuel. Experiments were performed on a single-cylinder optical research engine which is typical of modern, light-duty diesel engines. A high-speed digital camera recorded time-resolved combustion luminosity and an intensified CCD camera was used for single-cycle OH*chemiluminescence imaging. Experiments were performed for a wide range of equivalence ratios of the premixed charge. At low equivalence ratios, optical engine results revealed that combustion of the premixed charge of methane gas was dominated by spray entrainment and mixture stratification of diesel fuel. At higher equivalence ratios particularly close to stoichiometry, time-resolved natural luminosity images revealed significant modifications in combustion behavior indicating some evidence of flame propagation. Corresponding rates of heat release support the optical measurements in terms of revealing a significant impact on combustion following an increase of equivalence ratio. PLIF-tracer experiments were also performed in order to investigate the influence of in-cylinder fuel distribution on dual-fuel ignition.
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