Simple Instrument Research Articles

SIMPLE MUSICAL INSTRUMENTS USING TOUCHLESS TECHNOLOGY FOR KIDS

Musical instruments have been an important part of human culture since ancient times. In recent decades, technological developments have allowed us to create more sophisticated and creative musical instruments. one of them is by designing a simple musical instrument with arduino based touchless technology. In recent years, touchless technology has become increasingly popular in product and application development. Touchless technology allows users to interact with devices in a contactless manner or in other words not touching the device itself. The purpose of making a simple musical instrument design with touchless technology based on Arduino is to design a musical instrument that can be used even without touching the musical instrument. and it is also hoped that users, in this case children, will be interested or like the musical instrument. In addition, by designing a simple musical instrument with arduino-based touchless technology, it can provide an innovative and hygienic music playing experience for children. meaning that the touchless technology used in the musical instrument can minimize physical touch or physical contact for children, and also minimize the risk of transmission of diseases or viruses in children. With the experimental method, namely realizing a simple musical instrument with touchless technology, measurements can be made of the performance of the musical instrument and the effectiveness of touchless technology which is the main factor in the purpose of this tool, which is expected that children can be interested in the world of music

Validation of a Novel Electromagnetically Operated Free Flow Liquid Dispensing System

Repeat dispensing of liquids is a common requirement in many industries, often performed using automated machinery. These instruments often use complex mechanisms requiring expensive parts that may not be readily available. In resource-constrained regions there is a need for a simple device capable of reproducibly dispensing a controlled volume of fluid accurately. We evaluated the performance of a semi-automated liquid dispenser made from readily available parts that utilizes a programmable timer to trigger the activity of an electromagnetic valve, which allows delivery of liquid from a storage tank to the delivery nozzle via a flexible tube. The device was programmed to deliver a wide range of volumes and a gravimetric analysis of dispensed liquid was performed. The dispensed liquid maintained a linear relationship with the delivery time within the tested delivery range of 0.05 gram to 1.8 gram. It demonstrated high accuracy (>95%) and precision (coefficient of variation of <10%) for dispensing quantities more than 0.2 gram. However, the accuracy and precision suffered significantly below 0.2 gram. By changing nozzle diameters, we found a similar linear relationship between time and dispensed water weight for all tested nozzle sizes. By using a wide range of nozzle diameters, we could increase the range of delivery weight from 0.03 gram to 28.4 gram, with a very similar precision. This simple instrument is a user friendly, cost-effective, resource-efficient and reliable alternative for repeatedly dispensing a wide variety of liquids with various industrial applications, within a given volume range.

Collaborative validation of the quantification method for 57 allergens in ready to inject fragrance samples

AbstractThis publication presents the collaborative work conducted in CEN/TC 347/WG4 ‘Fragrance and colophony’ working group to evaluate the robustness of a GC–MS analytical methodology to quantify the extended list of 57 fragrance allergens in ‘ready to inject’ samples. The intention of this group was to provide an updated and consensual standard for the quantification of the extended allergen list. The analytical approach was based on the similar methodology than the original one developed for the 26 allergens, using a universal GC–MS simple quadrupole instrument. A ring test was performed among the different end‐user experiences of the CEN group to test the method on a representative fragrance matrix. Accuracy profile method was used to validate the analytical method within the 2–240 mg/kg concentration range. Thanks to the use of commercial standard mixes and dedicated automation of decisional tree for data treatment, 89% of tolerance intervals of targeted allergens were included into the acceptance limits in the whole 2–240 mg/kg concentration range. The objective of this article was to provide some complementary data to implement the NF EN 16274 standard in an analytical laboratory and to highlight the inherent difficulties linked to extended data treatment and complexity for the recovery of low concentration analytes and potential coelutions in a wide diversity of ready‐to inject samples.

Cu-Based Nanoneedle Array for Electrochemical Detection of Nitrate

The extensive usage of nitrogen-based fertilizers, food preservatives and explosive chemicals in various industries has led to the accumulation of nitrate in the ecosystems, especially in soil and water bodies. Several severe environmental and human health issues, including eutrophication, diseases related to N-nitroso compounds (such as Cancer, Parkinson and Gastritis) and blue-baby syndrome (methemoglobinemia), have arisen from the excessive nitrate concentration in the environment. Consequently, various government and regulatory agencies, such as the U.S. Environmental Protection Agency (EPA), have established the maximum nitrate ion concentration in drinkable water at 44 mg/L (0.71 mM). In this context, an accurate monitoring of the level of nitrate becomes important in environmental pollution control, food, clinical analysis, and other industries. While the spectroscopy techniques are of the most use due to its high precision and low limit of detection (LOD), these methods frequently require skilled workforces and specific instrumentations to operate. The electrochemical sensors benefit from recent developments of new nanomaterials to detect nitrate with a quick response, ability of continuously monitoring, small and simple instrumentation as well as easy to use. Several studies have utilized different strategies to fabricate Cu-based nanostructures (such as nanoparticles, nanoclusters, nanowires, and single-crystals) to achieve a low LOD. However, the sensitivity that has been achieved so far is still relatively low compared to the requirements for the real sampling applications.In this work, we utilized a one-step electrodeposition method to prepare Cu-based nano-array electrodes with high active surface sites, aiming for a fast and sensitive electrochemical detection of nitrate. The morphology of the array can be fine-tuned between nanoneedle and nanowire structures (Figure 1a and 1b). The x-ray diffraction (XRD) measurements indicate that the Cu-based nanoneedle array exhibited an abundant Cu(220) facet than the nanowire systems, which is usually associated with the active edge sites on copper (Figure 1c). The nanoneedle array was used for nitrate sensing via Cyclic Voltammetry methods which showed a sensitivity of 2.8 μA/μM*cm2, about 5-fold higher than the Cu foil control electrode (Figure 1d). The main reason of the sensitivity enhancement is that the nanoneedle structure resulted in a 30 times enrichment in the surface area compared to the Cu foil as shown in the electrochemical surface area (ECSA) measurement. Overall, our study provides a novel and convenient design of highly ordered Cu nanoneedle array structure for the sensitive electrochemical detection of nitrate. Figure 1

The diagnostic accuracy of spirometry as screening tool for adult patients with a benign subglottic stenosis

BackgroundThere is a considerable diagnostic delay in the diagnosis ‘benign acquired subglottic stenosis in adults’ (SGS, diagnosed by the reference standard, i.e. laryngo- or bronchoscopy). Patients are frequently misdiagnosed since symptoms of this rare disease may mimic symptoms of ‘asthma.’ The ‘Expiratory Disproportion Index’ (EDI) obtained by spirometry, may be a simple instrument to detect an SGS-patient. The aim of this study was to evaluate the diagnostic accuracy of the EDI in differentiating SGS patients from asthma patients.MethodsWe calculated the EDI from spirometry results of all SGS-patients in the Leiden University Medical Center (LUMC), who had not received treatment 2 years before their spirometry examination. We compared these EDI results with the EDI results of all true asthma patients between 2011 and 2019, who underwent a bronchoscopy (exclusion of SGS by laryngo- or bronchoscopy).ResultsFifty patients with SGS and 32 true asthma patients were included. Median and IQR ranges of the EDI for SGS and asthma patients were 67.10 (54.33–79.18) and 37.94 (32.41–44.63), respectively. Area under the curve (ROC) of the accuracy of the EDI at discriminating SGS and asthma patients was 0.92 (95% CI = 0.86–0.98). The best cut-off point for the EDI was > 48 (i.e. possible upper airway obstruction), with a sensitivity of 88.0%% (95%CI = 77.2-95.0%%) and specificity of 84.4% (95%CI = 69.4-94.1%).ConclusionsThe EDI has a good diagnostic accuracy discriminating subglottic stenosis patients from asthma patients, when compared to the reference standard. This measurement from spirometry may potentially shorten the diagnostic delay of SGS patients. Further studies are needed to evaluate clinical reproducibility.

A dilute-and-inject low-pressure gas chromatography-tandem mass spectrometry method for phthalate determination in extra virgin olive oil.

The goal of this study was to develop a method for the determination of nine phthalic acid esters in extra virgin olive oils using low-pressure gas chromatography-triple-quadrupole mass spectrometry. Sample preparation was simple, environmental friendly, and rapid inasmuch that it involved only dilution(<1mL of hexane). The low-pressure gas chromatography analyses were performed by using a 5 m wide-bore column. The limit of quantification for the phthalates ranged from 0.06 to 1.14mg kg-1 . Both intra- and interday precisions were measured, with coefficient of variation values ranging from 0.2% to 11.7%. The trueness of the method was measured by evaluating accuracy at the initial stage of the work and after 2 months, with values ranging between -8.7% and 12.1%. Moreover, blind accuracy was comprised between -11.6% and 14.2%. The method involves the use of simplified instrumentation and reduced analysis times (nearly two times faster) compared to a previously published comprehensive two-dimensional gas chromatography-triple-quadrupole mass spectrometry method, leading to a reduction of energy and helium consumption. The approaches were compared in analytical terms and for the environmental impact. In total, 23 olive oil samples were analyzed, with at least one phthalate detected in all but one sample.

AEROSOL OPTICAL DEPTH FROM SPECTRAL DIRECT NORMAL IRRADIANCE MEASUREMENTS IN MONTEVIDEO, URUGUAY

Abstract. Aerosols are liquid or solid particles with diameters between 2.5 and 10 µm suspended in the lower layers of the atmosphere. Aerosol Optical Depth (AOD) is a relevant parameter that quantifies their concentration in the atmosphere. It is usually estimated from sun photometer measurements at specific wavelengths. The objective of this work is to implement a simple inversion algorithm to retrieve AOD at six different wavelengths (340, 380, 440, 500, 675 and 870 nm) using solar direct normal spectral irradiance ground measurements from a relatively low cost collimated spectroradiometer (EKO MS-711) at a low-altitude site in Montevideo, Uruguay. The results obtained are compared with AERONET products for the same site, including AOD and Angström coefficient. The results of AOD for all wavelengths show a consistent negative mean bias (MBD, unitless), between −0.005 and −0.015, and dispersion (RMSD, unitless) between 0.021 and 0.015 (to be compared to a mean reference AOD of 0.097). These metrics improve considerably for very clear days, MBD up to ± 0.001 and RMSD under 0.007 (to be compared to a mean reference AOD of 0.058). These results are considered to be a first step in implementing the methodology and acquiring local knowledge about AOD retrievals using relatively simple instrumentation.

Field Measurements of Longshore Sediment Transport along Denu Beach, Volta Region, Ghana

Field measurements of longshore sediment transport have been performed in the surf zone along Denu Beach, located in the Volta Region of Ghana, West Africa. This study consisted of measuring sediment transport rates by the deployment of modified versions of Kraus streamer traps on a cross-shore distance, which was about half the average surf zone width. In addition to the measured transport rates, data on waves, longshore currents, and other morphological parameters were collected with simple and low-cost instrumentation. In total, about 22 datasets were obtained through several days of data collection spanning a period of 5 months. Mathematical formulae proposed by CERC (1984), Kamphuis (1991), and the new van Rijn (2014) were used to compute theoretical transports for the entire surf zone, which were validated by measured data. Applying the CERC equation with a K-value of 0.39, the theoretical transports were about one order of magnitude higher than the measured rates. The rates computed by the Kamphuis formula were slightly higher than those yielded by the van Rijn equation. They produced values that were, on average, about 3.5 and 2.9 times higher than the measured rates, respectively. This study then confirmed the capabilities of both the Kamphuis and van Rijn equations to provide closer estimates of longshore sediment transport on Denu Beach. It especially sheds light on the new van Rijn formula, which has not been used extensively in LST quantification across the world. We, therefore, concluded that both the Kamphuis and van Rijn equations could be particularly useful to local engineers in the prediction of LST prior to the design of coastal protection structures. Further long-term studies employing available cutting-edge technologies were also recommended to provide more information on longshore transport not only in Ghana but also in the entire Gulf of Guinea and for the establishment of a reliable sediment budget for the country and the entire region.

Optical imaging of in vivo adoptive T‐cell therapy: State of the art and challenges

AbstractAdoptive T‐cell therapy (ACT), which is an important type of live cell therapy, has achieved unprecedented success in treating hematological malignancies. Recent studies have shown that ACT is also a promising treatment for solid tumors. Visualizing the in vivo fates (distribution, homing, infiltration, proliferation, and exhaustion) of the immune cells used for ACT (ACT immune cells) is of great importance to promote basic research and clinical translation of ACT. Optical imaging techniques, including bioluminescence, fluorescence, and photoacoustic imaging, have the advantages of high sensitivity, high spatiotemporal resolution, minimal exposure to harmful radiation, and simple instrumentation. Recently, various types of optical imaging probes, including bioluminescence, fluorescence, and photoacoustic imaging probes, have been used to visualize ACT immune cells in vivo and evaluate the molecular mechanism, efficacy, and side effects of ACT. In this review, the optical imaging probes and labeling methods that have been used for in vivo visualization of ACT immune cells are summarized, and the opportunities and challenges of using optical imaging to visualize ACT immune cells in vivo are discussed.

Development and validation of a parental competence questionnaire in the paediatric hospital emergency setting (ECP-U)

ObjectiveTo develop and validate a parental competence questionnaire for parents of children seeking care in hospital emergency departments. MethodsAn instrumental study of the development of an assessment questionnaire was carried out in three phases: 1) review of relevant measures and item generation, 2) content validity evaluation, 3) psychometric evaluation. Exploratory factor analysis was performed to examine the factorial structure. Internal consistency was evaluated using ordinal alpha. Hypothesis testing was determined between the resulting factors, the Parental Stress Scale and the State-Trait Anxiety Inventory. ResultsThe participants were 270 parents of children aged 0–14 years old from a referral hospital in Valencia (Spain). An 18-item questionnaire was developed, comprising five factors that explain 53.0% of the variance: 1) “emotional management and expression”, 2) “passive social support”, 3) “parental agency”, 4) “basic needs and care” and 5) “active social support”. The internal consistency for the different factors was modest (>0.70). A negative correlation between the Parental Stress Scale and the parental competence questionnaire was found for most of the factors. ConclusionsThis questionnaire on parental competence in the hospital emergency department (ECP-U) is a useful and simple self-report instrument for assessing the parental competence of parents with children in the emergency department. Practical implicationsThe resulting questionnaire is of practical value to both healthcare professionals and researchers in this field. It can be administered quickly in clinical practice and used to identify parents' levels of parental competence and refer those with difficulties to appropriate support services.

RART-LAMP: One-Step Extraction-Free Method for Genotyping within 40 min.

Loop-mediated isothermal amplification (LAMP) is a commonly used alternative to PCR for point-of-care detection of nucleic acids due to its rapidity, sensitivity, specificity, and simpler instrumentation. While dual-labeled TaqMan probes are widely used in PCR for single-nucleotide polymorphism (SNP) genotyping, real-time LAMP primarily relies on turbidimetry or intercalator fluorescence measurements, which can be non-specific and generate false-positive results. In this study, we propose a closed-tube, dual-labeled RNA-modified probes and RNase H II-assisted real-time LAMP (RART-LAMP) method for SNP genotyping. Our findings indicate that (1) fluorescence signals were predominantly derived from probe hydrolysis rather than hybridization, (2) temperature-controlled hybridization between the probe and template ensured the specificity of SNP analysis, and (3) RNase H II hydrolysis between the target containing SNP sites and probes did not exhibit sequence specificity. Our RART-LAMP approach demonstrated excellent performance in genotyping C677T clinical samples, including gDNA extracted from blood, saliva, and swabs. More importantly, saliva and swab samples could be directly analyzed without any pretreatment, indicating promising prospects for nucleic acid analysis at the point of care in resource-limited settings.

Vibration Measurements by Self-Mixing Interferometry: An Overview of Configurations and Benchmark Performances

Self-mixing interferometry (SMI) is suitable to sense and measure vibrations of amplitudes ranging from picometers to millimeters at frequencies from sub-Hz to MHz’s. As an optical probe, SMI has the advantage of being non-invasive with the ability to measure without any treatment of the target surface and operate from a substantial standoff distance from the target. As an additional advantage, the SMI configuration is much simpler than that of conventional interferometers as it does not require any optical part external to the laser source. After a short introduction to the basics of SMI, we review the development of configurations of SMI instruments for vibration measurements, based on both analog and digital processing, with record performance to cover the range of vibration amplitudes from 0.1 nm to 1 mm, frequencies up to MHz, and stand-off distances up to 100 m. These performances set a benchmark that is unequaled by other approaches reported so far in the literature. The configurations we describe are (i) a simple MEMS-response testing instrument based on fringe counting, (ii) a half-fringe locking vibrometer for mechanical mode analysis and transfer function measurements, with a wide linear response on six decades of amplitude, (iii) a vibrometer with analog switching cancellation for μm-to-mm amplitude of vibrations, and (iv) a long standoff distance vibrometer for testing large structures at distances up to 100 m and with nm sensitivity. Lastly, as the vibrometer will almost invariably operate on untreated, diffusing surfaces, we provide an evaluation of phase-induced speckle pattern errors affecting the SMI measurement.

Determination of rhein and physcion in rhubarb by microchip capillary electrophoresis in mixed hydro-organic solvent combined with laser-induced fluorescence detection.

Microchip capillary electrophoresis in mixed hydro-organic solvent combined with laser-induced fluorescence detection was developed for the separation and detection of physcion and rhein in rhubarb. In contrast to the conventional capillary electrophoresis method, ammonium acetate-dimethyl sulfoxide was used as the basic buffer system in this method. The effects of background buffer, buffer apparent pH*, buffer concentration, water ratio, sample preparation method, and separation voltage on separation and detection were investigated. Optimized separation and detection conditions were obtained: the buffer consisted of 20mmol/L of ammonium acetate in hydro-organic solvent composed dimethyl sulfoxide, formamide, and water mixed at 60/20/20 (v/v/v) ratio. The separation voltage was 1.9kV. Under these conditions, the physcion, rhein, and other components of rhubarb can be completely separated within 150 s. Under the methodological verification, good linearity (R ≥ 0.9995) for physcion and rhein, and low limits of detection (0.085μg·mL-1 and 0.077μg·mL-1 , respectively), satisfactory peak area precisions, migration time precisions (1.74%-3.09%), and accuracy (recovery rate 97.8% and 101.4%) were achieved. It is shown that the proposed method is simple, efficient, fast, sensitive, simple instrument, consumes few samples, has low operating cost, and is linear.

Shock index in the emergency department as a predictor for mortality in COVID-19 patients: A systematic review and meta-analysis

BackgroundThe shock index (SI) ratio serves as a straightforward predictor to identify patients who are either at risk of or experiencing shock. COVID-19 patients with shock face increased mortality risk and reduced chances of recovery. This review aims to determine the role of SI in the emergency department (ED) to predict COVID-19 patient outcomes. MethodsThe systematic search was conducted in PubMed, ProQuest, Scopus, and ScienceDirect on June 16, 2023. We included observational studies evaluating SI in ED and COVID-19 patient outcomes. Random-effect meta-analysis was done to generate odds ratios of SI as the predictor of intensive care unit (ICU) admission and mortality. The sensitivity and specificity of SI in predicting these outcomes were also pooled, and a summary receiver operating characteristics (sROC) curve was generated. ResultsA total of eight studies involving 4557 participants were included in the pooled analysis. High SI was found to be associated with an increased risk of ICU admission (OR 5.81 [95%CI: 1.18–28.58], p = 0.03). Regarding mortality, high SI was linked to higher rates of in-hospital (OR 7.45 [95%CI: 2.44–22.74], p = 0.0004), within 30-day (OR 7.34 [95%CI: 5.27–10.21], p < 0.00001), and overall (OR 7.52 [95%CI: 3.72–15.19], p < 0.00001) mortality. The sensitivity and specificity of SI for predicting ICU admission were 76.2% [95%CI: 54.6%–89.5%] and 64.3% [95%CI: 19.6%–93.0%], respectively. In terms of overall mortality, the sensitivity and specificity were 54.0% (95%CI: 34.3%–72.6%) and 85.9% (95%CI: 75.8%–92.3%), respectively, with only subtle changes for in-hospital and within 30-day mortality. Adjustment of SI cut-off to >0.7 yielded improved sensitivity (95%CI: 78.0% [59.7%–89.4%]) and specificity (95%CI: 76.8% [41.7%–93.9%]) in predicting overall mortality. ConclusionSI in emergency room may be a simple and useful triage instrument for predicting ICU admission and mortality in COVID-19 patients. Future well-conducted studies are still needed to corroborate the findings of this study.

Construction of Magnetic Core-Large Mesoporous Satellite Immunosensor for Long-Lasting Chemiluminescence and Highly Sensitive Tumor Marker Determination.

Chemiluminescence immunoassay exhibits high sensitivity and signal-to-noise ratio, thus attracting great attention in the early diagnosis and dynamic monitoring of diseases. However, the collection of conventional flash-type chemiluminescence signal (<5s) relies heavily on automatic sampling and reading instrument. Herein, a novel core-satellite multifunctional chemiluminescence immunosensor is designed for the efficient enrichment and highly sensitive determination of cancer biomarker carcinoembryonic antigen (CEA) with enhanced and long-lasting output signal that can be conveniently recorded by a simple microplate plate reading instrument. Anti-CEA monoclonal antibody 2 (Ab2) modified Fe3 O4 @SiO2 microspheres (Fe3 O4 @SiO2 -Ab2, 370nm in diameter) are synthesized as the core for selectively capturing and enriching target CEA in solution, and anti-human CEA monoclonal antibody 1 (Ab1) and horseradish peroxidase (HRP) co-immobilized dendritic large-mesoporous silica nanospheres (MSNs-HRP/Ab1, 80nm in diameter, pore size: 17nm) are synthesized as the satellite for efficient immunological recognition and signal amplification. The as-designed core-satellite magnetic chemiluminescence immunosensors exhibit a broad linear range of 0.01-20ngmL-1 and a low detection limit of 3.0pgmL-1 for the convenient, highly specific, and sensitive determination of CEA in human serum. Such core-satellite chemiluminescence immunosensors are expected to act as a powerful tool for in vitro detection of various biomarkers, overcome the defect of conventional chemiluminescence relying heavily on expensive and bulky automatic instruments and popularize chemiluminescence analysis to primary medical institutions and remote areas.

Development of extension-mediated self-folding isothermal amplification technology for SARS-CoV-2 diagnosis

The coronavirus disease (COVID-19) pandemic has highlighted the importance of rapid and accurate diagnosis, and loop-mediated isothermal amplification (LAMP) has become a popular method because of its powerful amplification ability using a simple instrument such as a heater or water bath. However, LAMP has limitations such as the complexity of primer design and the difficulty of designing sequence-specific probes, leading to non-specific amplicons and false-positive results.To overcome these limitations, we developed a novel isothermal amplification system called the Extension-mediated self-folding Isothermal amplification Technology (ExIT). ExIT uses a newly designed, self-folding primer (SP) with two key functions. Hairpin structures are formed when the extended strand of the SP hybridizes, exposing the priming site for continuous binding of the new SP. This results in exponential amplification with only two primers, unlike conventional LAMP primer systems. Additionally, an unnatural base was introduced into the SP, which terminated the extension of polymerase and generated a ssDNA amplicon. This makes it easier to design and apply probes, reducing the possibility of false-positive results even if non-specific amplicons are produced.Through this strategy, we confirmed a sensitivity of 90 copies (3.6 copies/μL) and verified the specificity by testing for the presence or absence of non-complementary targets. Therefore, the validation of the ExIT was completed. In conclusion, ExIT will be key to solving the complexity of conventional LAMP design and offers great potential for successfully introducing sequence-specific probes to improve false positives.

Development and validation of a predictive model for the diagnosis of rheumatic heart disease in low-income countries based on two cross-sectional studies

ObjectivesWe developed a questionnaire-based risk-scoring system to identify children at risk for rheumatic heart disease (RHD) in rural India. The resulting predictive model was validated in Nepal, in a population with a similar demographic profile to rural India. MethodsThe study involved 8646 students (mean age 13.0 years, 46% boys) from 20 middle and high schools in the West Midnapore district of India. The survey asked questions about the presence of different signs and symptoms of RHD. Students with possible RHD who experienced sore throat and joint pain were offered an echocardiogram to screen for RHD. Their findings were compared with randomly selected students without these symptoms. The data were analyzed to develop a predictive model for identifying RHD. ResultsBased on our univariate analyses, seven variables were used for building a predictive model. A four-variable model (joint pain plus sore throat, female sex, shortness of breath, and palpitations) best predicted the risk of RHD with a C-statistic of 0.854. A six-point scoring system developed from the model was validated among similarly aged children in Nepal. ConclusionsA simple questionnaire-based predictive instrument could identify children at higher risk for this disease in low-income countries where RHD remains prevalent. Echocardiography could then be used in these high-risk children to detect RHD in its early stages. This may support a strategy for more effective secondary prophylaxis of RHD.

Renewable Electricity Transition: A Case for Evaluating Infrastructure Investments through Real Options Analysis in Brazil

This paper explores the uncertainty of expected returns by adopting the real options analysis method for the financial evaluation of renewable energy projects in Brazil. Energy transition is key to meeting climate targets, and real options analysis can play a pivotal role in evaluating renewable energy projects to meet those targets. The impact of the volatility of the chosen variables on the viability of the project is studied using Monte Carlo simulation in the R software. The results indicate that the lower the option value the higher the volatility of the project, leading to lower likelihood of the project being financed. The resulting model represents a simple instrument that can be incorporated in larger modelling frameworks (e.g., agent-based simulation) to assess the impact of real option analysis on different markets and environmental and socio-political conditions. These findings represent a strong case for the adoption of systems modelling to inform policy to support global energy transition, as the application of this method can make a renewable energy project financially more attractive in comparison to those relying on carbon intensive energy sources.

Simple and Accurate Instrumentation Device to Detect Loose-End Defective Cigarettes

Loose-end defect on the tip of the cigarette is a common problem found on production lines. Large companies use computerized sophisticated machines to detect and reject it automatically. However, the same solution can not be implemented in small or home industries because the investment cost is too high. This paper presents the development of simple electronic instrumentation to detect loose-end defects in cigarettes. It relies on the signal acquisition of a photoelectric transceiver mechanism that is converted and processed digitally to relatively quantify the difference between the good and defect. Motor-driven cigarette rotator device was built specially to test the performance of the instrumentation system. Loose-end defects are made artificially by removing 0.2 gr tobacco from the tip of a normal cigarette. The average quantifying relative value was found above 58.5%, this indicates that the system has good contrast properties. At the speed of 10,000 cigarettes/min, the average accuracy is 90.5%, and at 17,500 cigarettes/min, the average accuracy is 65.3%.

Method for the refractive index of various tissues based on fluorescence microscopy

Refractive index is an important optical constant that characterizes the interaction between light and specimen. A difference in refractive index between specimen and immersion medium introduces the imaging aberration and leads to a problem that the direct thickness measurement of a specimen by optical microscopy is not accurate. However, this aberration correction still requires the exact information of the refractive index of specimen and immersion medium. Herein, we propose an imaging strategy to estimate the refractive index for an unknown specimen. A simplified diffraction model is generated to obtain the relationship between axial scaling factor and refractive index. Then regular fluorescence microscopy is performed to measure the actual axial scaling factors of specimens from mouse muscle and tumor xenograft. Referring to our theoretical plot of axial scaling factor versus refractive index, the refractive index of tissue specimen is determined. For example, we obtain a mean refractive index (n) value of 1.36 for normal muscle tissues, and 1.41 for tumor xenografts. We demonstrate that this diffraction model-based estimation method is an alternative to the current techniques, improving the accurate measurement for refractive index of tissue specimen. The simple instrument requirement with an easy specimen preparation for this estimation method of refractive index may increase the image quality on tissue specimens with less aberration.