Double-pass System Research Articles

Energetic and Exergetic Analyses of a Double-Pass Tubular Absorber for Application in Solar Towers

Abstract The present research integrates the concept of double-pass (DP) flows with high-temperature solar receivers to introduce an innovative design aimed at minimizing heat losses and optimizing performance. The new DP system was developed using a tubular absorber derived from billboard solar tower technology and operated with air as the heat transfer medium. Computational fluid dynamic models are developed based on an experimental campaign conducted at a solar furnace facility. The computational analyses indicated that employing the DP design instead of single-pass (SP) absorbers results in an average enhancement of energy and exergy efficiency by 35% and 225%, respectively, across all test conditions. However, this enhancement is accompanied by an average increase in pressure drop of ∼60%. The detailed exergy analysis also revealed the contribution of each term in the exergetic performance, identifying the exergy destruction between the sun and the absorber as the primary source, accounting for an average of ∼65% of the total inlet exergy for both SP and DP absorbers. Consequently, the DP presents itself as a promising alternative design for future solar tower configurations, offering improved Nu numbers up to ∼50% in air-based solar systems.

High-Speed Schlieren Imaging of Vapor Formation in Electrospray Plume.

Previous mechanistic descriptions of electrosprays mostly focused on the dynamics of Taylor cones, initial droplets, and progeny droplets. However, vapor formation during droplet desolvation in an electrospray plume has not been discussed to a great extent. Here, we implement a double-pass on-axis schlieren high-speed imaging system to observe generation and propagation of vapors in an offline electrospray source under different conditions. Switching between turbulent and laminar vapor flow was observed for all of the scanned conditions, which may be attributed to randomly occurring disturbances in the sample flow inside the electrospray emitter. Calculation of mean vapor flow velocity and analysis of vapor flow patterns were performed using in-house developed image processing programs. Experiments performed at different electrospray voltages (0-6 kV), solvent flow rates (100-600 μL min-1), and methanol concentrations (50-100%), indicate only a weak dependency between electrospray voltage and mean vapor velocity, implying that the vapor is mostly neutral; thus, the vapor is not accelerated by electric field. On the other hand, electrospraying solutions of analytes (with mass 151 Da or 12 kDa) did not remarkably increase the overall vapor flow velocity. The source of vapor's velocity is attributed to the inertia of the electrospray droplets. Although there are some differences between a modern electrospray ionization (ESI) setup and the setup used in our experiment (e.g., using a higher flow rate and larger emitter), we believe the findings of our study can be projected to a modern ESI setup.

Development of dual-path multi-pass Thomson scattering system in GAMMA 10/PDX

A dual-path Thomson scattering (DPTS) system was developed to measure electron temperature and density in a GAMMA 10/PDX central cell (CC) and an end cell (EC). The DPTS comprises CC Thomson scattering system (CC-TS) and an EC Thomson scattering system (EC-TS). In the CC-TS, we developed a multipass system to improve the signal intensities and time resolution. In the EC-TS, a double-pass system was developed as a preliminary step in developing a multipass system. In a previous EC-TS, the optical components for the double-pass configuration were placed in a vacuum vessel. To reduce the influence of stray light and facilitate alignment, a hole for the double-pass laser path was made on the partition wall in the vacuum chamber such that the probe laser could be extracted into the atmosphere and the double-path configuration could be easily adjusted. We applied DPTS to detached plasma experiments and successfully measured the core and edge electron temperatures and densities with the detached plasma experiments with the additional application of supersonic molecular beam injection and central electron cyclotron heating in the core plasma to simultaneously introduce intermittent particle flux.

Comparison of optical myopia control interventions: effect on peripheral image quality and vision.

This study compares the effects on peripheral vision and image quality of four myopia control interventions: a) Perifocal spectacles/ArtOptica, b) Stellest spectacles/Essilor), c) MiyoSmart spectacles/Hoya and d) MiSight contact lenses/CooperVision. Five subjects participated with habitual or no correction as reference. Three techniques were used: 1) Hartmann-Shack sensors for wavefront errors, 2) double-pass imaging system for point-spread-functions (PSF), and 3) peripheral acuity evaluation. The results show that multiple evaluation methods are needed to fully quantify the optical effects of these myopia control interventions. Perifocal was found to make the relative peripheral refraction (RPR) more myopic in all subjects and to interact with the natural optical errors of the eye, hence showing larger variations in the effect on peripheral vision. MiSight had a smaller effect on RPR, but large effect on peripheral vision. Stellest and MiyoSmart also showed small effects on RPR but had broader double-pass PSFs for all participants, indicating reduced retinal contrast. Reduction in peripheral retinal contrast might thereby play a role in slowing myopia progression even when the peripheral refraction does not turn more myopic.

Differences in retinal images quality between normal and subclinical keratoconus and its association to posterior corneal asymmetry.

To compare retinal image quality in subclinical keratoconus and normal eyes using a double-pass aberrometer and to correlate it with posterior surface deformation. Sixty normal corneas were compared to 20 subclinical keratoconus (SKC) corneas. Retinal image quality was assessed using a double-pass system in all the eyes. The objective scatter index (OSI) modulation transfer function (MTF) cutoff, Strehl ratio (SR), and Predicted Visual Acuity (PVA) values at 100%, 20%, and 9% were calculated and compared between the groups. Posterior corneal asymmetry was measured using a combined Placido Dual Scheimpflug Analyzer, and correlations were tested with all optical quality parameters. Significant decrease in optical quality parameters was observed in SKC eyes compared with that in normal eyes. Subclinical KC eyes expressed greater scattering (OSI = 0.66 ± 0.36 vs 0.47 ± 0.26) and reduced contrast images (MTF and SR) than normal eyes, with 38.82 ± 9.4 and 0.22 ± 0.04, and 44.35 ± 7.1 and 0.24 ± 0.04, respectively. The reduction in the image contrast parameters (MTF and SR) was strongly correlated to the level of posterior corneal asymmetry in SKC. The greater the posterior asymmetry, the more affected was the image contrast, with r = -0.63 and -0.59, respectively for MTF and SR. Retinal image quality was significantly more affected in eyes with subclinical keratoconus than in normal eyes. The reduction in optical quality observed in subclinical keratoconus was strongly associated with the increased asymmetry of the posterior cornea.

Simultaneous real-time analysis of tear film optical quality dynamics and functional visual acuity in dry eye disease

BackgroundTo assess the effect of tear film instability in dry eye disease (DED) by measuring visual performance and tear film optical quality in a simultaneous real-time analysis system.MethodsThirty-seven DED participants and 20 normal controls were recruited. A simultaneous real-time analysis system was developed by adding a functional visual acuity (FVA) channel to a double-pass system. Repeated measurements of FVA and objective scatter index (OSI) were performed simultaneously with this system under blink suppression condition for 20 s. Patient-reported symptoms was evaluated using the Ocular Surface Disease Index (OSDI) questionnaire. Mean FVA, mean OSI, and visual acuity break-up time were defined. The OSI maintenance ratio was calculated as an evaluation index to assess the difference between dynamic OSI changes and baseline OSI. The visual maintenance ratio was also calculated in the same way.ResultsModerate correlations were noted between mean OSI and FVA-related parameters (mean FVA, visual maintenance ratio, visual acuity break-up time: 0.53, − 0.56, − 0.53, respectively, P < 0.01 for all). Moderate to high correlations were noted between OSI maintenance ratio and FVA-related parameters (mean FVA, visual maintenance ratio, visual acuity break-up time: − 0.62, 0.71, 0.64, respectively, all P < 0.01). The metrics derived from the simultaneous real-time analysis system were moderately correlated with the patient-reported symptoms and the visual acuity break-up time possessed the highest correlation coefficients with OSDI total, ocular symptoms, and vision-related function (− 0.64, − 0.63, − 0.62, respectively, P < 0.01). The OSI-maintenance ratio alone appeared to exhibit the best performance of the metrics for the detection of DED with sensitivity of 95.0% and specificity of 83.8% and the combinations of FVA parameters and OSI parameters were valid and can further improve the discriminating abilities.ConclusionsOSI-related metrics were found to be potential indicators for assessing and diagnosing DED which correlated with both subjective visual performance and patient-reported symptoms; the FVA-related metrics were quantifiable indicators for evaluating visual acuity decline in DED.Trial registration number: Chinese Clinical Trial Registry, ChiCTR2100051650. Registered 29 September 2021, https://www.chictr.org.cn/showproj.aspx?proj=134612

Calibration of a collinear backscattering Mueller matrix imaging system

A collinear backscattering Mueller matrix (CBMM) imaging system has clear advantages in the detection of bulk biological tissues, which are highly scattering and depolarizing. Due to the double-pass configuration and noise in the system, the calibration of a collinear backscattering Mueller matrix imaging system is usually complex and of poor accuracy. In this work, we propose an alternative modified eigenvalue calibration method (ECM) based on the equivalent standard sample. For better noise suppression and higher calibration accuracy, we design the distribution of polarization states over the Poincaré sphere and solve for the parameters of equivalent standard samples by means of an optimization. Compared to other variants of the eigenvalue calibration method used in the double-pass system, the accuracy of the proposed method is improved by more than 40 times. The comparison results with the error model-based calibration methods indicate that the modified eigenvalue calibration method generally gives the best accuracy and precision, as well as the best reliability.

Quality of Vision After LASIK, PRK and FemtoLASIK: An Analysis Using the Double Pass Imaging System HD AnalyzerTM®.

PurposeAnalyze and compare the quality of vision of Photorefractive keratectomy (PRK), LASER in situ keratomileusis with mechanical microkeratome (LASIK) and femtosecond-assisted LASIK (FS-LASIK) using the double-pass imaging system HD AnalyzerTM®.SettingOphthalmology department of Centro Hospitalar Universitário do Porto (CHUPorto).DesignRetrospective, non-randomized, single center study.MethodsAnalysis of three equivalent groups of patients submitted to PRK, LASIK and FS-LASIK at our department. The objective quality of vision assessment included the objective scatter index (OSI), the modular transfer function cutoff frequency (MTF) and the predicted visual acuity within the 100% (PVA), 20% (PVA20) and 9% contrast levels (PVA9) that were evaluated at baseline, 1st week, 1 and 6 months after surgery.Results118 eyes were included: 40 underwent LASIK, 43 FS-LASIK and 35 PRK. The mean age was 30.6±4.6 years old and 56% were female. There was a significant impact concerning the type of procedure in the objective quality of vision analysis (Repeated measures ANOVA): the FS-LASIK group showed lower OSI values overtime [F(1,2)=4.566, p=0.012, OSI 0.83±0.53 (FS-LASIK) vs 0.87±0.47 (PRK) and 1.21±1.44 (LASIK)], higher MTF values [F(1,2)=6.569, p=0.002, MTF 40.17±8.33 vs 32.37±11.4 (PRK) and 30.26±10.28 (LASIK)], higher PVA 100% [F(1,2)=10.871, p<0.001], PVA 20% [F(1,2)=9.737, p<0.001] and PVA 9% [F(1,2)=6.335), p=0.003].ConclusionIn our study, FS-LASIK showed an excellent optical performance through the HD AnalyzerTM technology, with significantly lower OSI and higher MTF, PVA100, PVA20 and PVA9 values. According to our results, this procedure seems to be superior to PRK and LASIK regarding visual quality objective parameters.

Sub-60-fs, compact 1100-nm fiber laser system based on double-pass pre-chirp managed amplification.

An ytterbium-doped, single-stage, double-pass nonlinear fiber amplification system was fabricated for amplifying an 1100-nm mode-locking fiber laser. Pre-chirp managed amplification (PCMA) was applied in realizing the nonlinear amplification process with an all-polarization-maintaining (PM) fiber construction. The system can deliver 19.8-nJ, 58.7-fs, 24.4-MHz amplified signal pulses with a 10-dB spectral range spanning from 1049 nm to 1130 nm. Further experimental investigations were conducted in exploring the dynamics of the double-pass nonlinear amplification process. This compact 1100-nm ultrafast fiber laser can be implemented for multi-photon microscopy (MPM) with deep penetration depth.

100 kHz Narrow-Linewidth Burst-Mode MOPA Laser System With Uniform Envelope

In this study, a 100-kHz narrow-linewidth burst-mode laser system combined with a master oscillator power amplifier (MOPA) structure was reported with a stable pulse burst profile over 2 ms duration. A theoretical model was established to characterize and compensate the variation characteristics of coefficient of variation (COV) within a burst envelope for the double-pass three-stage amplification system, in terms of different parameter factors. Simulated results yielded similar tendency with the measured ones. For a stable burst envelope with a COV of 2.72% and 2.93%, output pulse energy at a 100 kHz repetition rate was scaled up to 1.08 and 4.38 mJ in the case of an input average pulse energy of 8.6 and 116.51 nJ, respectively. Corresponding Mx2 and My2 values with 2.2 and 2.4 were endowed with 1.08 mJ output single-pulse energy and 2.7 and 2.1 for 4.38 mJ pulse energy. The spectral linewidth of amplified pulses was measured to be less than 83.1 and 67.9 MHz, with respect to output pulse duration of 10.3 and 96.1 ns, respectively.

An overview on dry eye disease diagnosis: options for new non-invasive testing technologies

This literature review intends to provide an overview of the new non-invasive testing technologies and their role in the diagnosis of dry eye disease (DED). Including imaging technologies of tear volume, tear film stability, meibomian glands morphology and function, corneal morphology, biomarkers and ocular surface temperature, as well as tear osmolarity, optical quality, blinking test and so on. New testing technologies can provide an indirect and objective assessment of the ocular surface, tear condition and visual quality. Testing technologies, such as tear volume, meibography and tear osmolarity have been widely recognized and applied in clinical practice, showing higher specificity and sensitivity than traditional tests. Others, such as strip meniscometry, interferometer, light scattering technology, double-pass system, blinking test and so on, are currently in the stage of clinical research and improvement, and may translate to routine clinical detection techniques in the future. The new non-invasive testing technologies can non-invasively evaluate the ocular surface and tears, and measure the changes of components related to the disease, which play an important role in the diagnosis, classification, clinical management and curative effect evaluation of DED.

Thermo-hydraulic analysis of a solar cogeneration air-heater

The requirement of energy becomes utmost essential for sustainability of modern societies and for future growth of economy and industries. The ever-increased demand of energy has put tremendous pressure on conventional energy resources which are already been stretched to its limit. The renewable energy resources especially solar energy being a viable and sustainable source of energy has acclaimed a wide attention as prominent substitute to conventional energy sources. Among these, the utility of solar air heater is yet to be explored fully. SAH has a number of applications namely drying of aquatic products, drying of crops, room heating and other industrial applications. However, the drawbacks of SAH are weather and time dependency, need of large heat transfer area and a large volume flow of air due to depressing heat transfer coefficient of air. To mitigate the aforementioned problems, a double-glazed double-pass SAH system is proposed and tested theoretically. The focus of the recommended system is to minimize the factors which reduce the performance of the conventional SAH. A comparative study is done between the double-glazed DPSAH system with and without roughness.

Open-view Binocular Double-pass System for the Study of Dynamic Accommodation

We present a new open-view dynamic double-pass (DP) system for the study of accommodative response in binocular natural viewing conditions. The DP point spread function (PSF) of the eye is analyzed to compute the Visual Strehl Ratio (VSR) fluctuation as a function of time at 50 Hz frame rate. Preliminary results showed that the proposed method can quantify the temporal dynamic of the optical and visual quality of both eyes simultaneously.

Parametric study of a solar dryer system for the development and application of solar energy in Sierra Leone

A transient mathematical model has been evaluated to determine the principle of a solar crop dryer for drying vegetables (onion). Considering the meteorological conditions of Freetown (Latitude 8.4840 N, Longitude -13.2300 W), the model was developed to determine air temperatures and other operational parameters of the drying system for a day of March 21st. However, the investigated system had effectively reduced the drying process of onion. The developed double-pass solar air collector system showed a low-temperature output in the morning hours and displayed high-temperature results in the afternoon hours. From 8:00 to 16:00, the solar collector generates fluid output temperatures above 50 0 C, with a peak value of 96 0 C occurred at 12:00. The influence of the mass flow rate on the system's thermal efficiency was investigated. It was noticed that for a certain solar radiation value, an increased in the mass flow rate caused an exponential increased in the solar air collector thermal efficiency. Findings also revealed that an increased in the solar collector length led to a slightly decreased in the outlet air temperatures at a mass flow rate of 0.02 kg/s. The influence of increasing drying air temperatures and air velocity within the drying chamber reduces drying time significantly. The drying time for products dried in the first tray is lesser than for products dried in the subsequent trays, owing to temperature variations. The computation findings were verified to previous studies in the literature and observed to be strongly comparable.

Experimental determination of the lateral resolution of surface electric potential measurements by Kelvin probe force microscopy using biased electrodes separated by a nanoscale gap and application to thin-film transistors.

A method is proposed to estimate the lateral resolution of surface potential profile measurements using Kelvin probe force microscopy (KPFM) on operating electronic devices. De-embedding the measured profile from the system response is required for various applications, such as contact characterization of thin-film transistors, or local longitudinal electric field measurements. A method is developed based on the measurement of the electric potential profile of two metallic electrodes separated by a nano-gap, providing a quasi-planar configuration. The electrodes are independently biased so as to produce an abrupt and well-controlled potential step. This calibration sample is used to measure the system impulse response in various configurations. Due to the application constrains, the KPFM method employed here is based on a dual-pass mode, demonstrated to provide reliable measurements on operating electronic devices. The method is applied to two types of conductive AFM probes. Measurements are performed at different tip-to-sample heights allowing the determination of the lateral resolution of the double-pass method. Detailed description of the measurements and resolution results are given for the present KPFM configuration. The system resolution measurement technique can be extended to other KPFM modes and can be used to monitor the degradation of the tip quality during long measurement campaigns. Finally, the method is applied to the characterization of thin-film transistors, and the effects of contact edge sharpness on the device behavior is discussed. The longitudinal electric field responsible for charge injection at the source-contact edge is successfully estimated and compared for organic thin-film transistors fabricated by stencil lithography or electron-beam lithography.

Diffraction efficiency of a double-pass acousto-optic modulation system

espanolSe describe la caracterizacion de un sistema de modulacion acusto-optico y la optimizacion del set up para mejorar la eficiencia de la difraccion en configuraciones de paso simple y doble. En la configuracion de paso simple, el sistema consta de un modulador acusto-optico, un oscilador controlado por voltaje (V.C.O) y un amplificador de radiofrecuencia, en la cual, se caracterizo la eficiencia de la difraccion y la potencia optica del haz difractado en funcion de la radiofrecuencia aplicada. Adicionalmente, tomando como referencia la necesidad de corregir la variacion del angulo de difraccion que se puede tener cuando se modula en frecuencia el sistema en paso simple, se presenta su correccion por medio de la implementacion de la configuracion en paso doble. La configuracion de paso doble, consta de un VCO que controla la senal acustica entrante al modulador, un modulador el cual difracta la luz incidente y esta pasa por una lamina retardadora para evitar la retro reflexion del haz; despues usando un iris se deja pasar solo el orden 1 de difraccion luego se usa un espejo plano el cual direcciona el laser en la segunda pasada de este en el modulador. Una vez optimizado el sistema en paso doble se procedio a obtener la curva de eficiencia de difraccion y potencia en funcion de la frecuencia. Este trabajo se presenta como una herramienta actualizada para la caracterizacion e implementacion de un sistema de modulacion acusto-optico en configuracion de doble paso. EnglishWe described the characterization of an acousto-optic modulation system and the optimization of the set up to improve the efficiency of diffraction in single and double-pass configurations. In the singlepass configuration, the system consists of an acousto-optic modulator, a voltage-controlled oscillator (VCO) and a radio frequency amplifier, in which the diffraction efficiency and the optical power of the diffracted beam were characterized in the function of the applied radiofrequency. Additionally, taking as a reference the need to correct the variation of the diffraction angle that may occur when the system is modulated in frequency in a simple step, its correction is presented by means of the implementation of the configuration in double step. The double-pass configuration consists of a VCO that controls the incoming acoustic signal to the modulator, a modulator which diffracts the incident light and this passes through a retarder sheet to avoid the retroreflection of the beam; Then, using an iris, only order 1 of diffraction of the beam was allowed to pass and a plane mirror was used for working in the infrared which directs the laser in the second pass of it in the modulator. Once the double-pass system had been optimized, the diffraction efficiency curve was obtained. This work is presented as an updated guide for the implementation of an acousto-optic modulation system in a double-pass configuration.

Influence of Reading on Smartphone Screens on Visual Optical Quality Metrics and Tear Film Stability.

To evaluate the impact of a prolonged reading session on a smartphone screen on optical quality metrics and tear film stability. This prospective study was conducted in 41 healthy volunteers who were asked to read an article on a smartphone screen for 20 minutes. The following tests were performed before the reading task in this consecutive order and repeated after the reading task in the same order: automated noninvasive tear break-up time, optical quality assessment including Objective Scatter Index (OSI), modulation transfer function, Strehl ratio, and tear film dynamic analysis as follows: vision break-up time (VBUT) as a function of OSI changes within 20 seconds, using a double-pass aberrometer imaging system, and fluorescein tear break-up time (FBUT) measured using the slit lamp. All break-up time-related parameters (noninvasive tear break-up time, FBUT and VBUT) were significantly reduced after the reading task (P < 0.01). The OSI was significantly worsened after the reading task (P = 0.01), whereas all the other optical quality metrics (modulation transfer function and Strehl ratio) slightly deteriorated, were not statistically significant. A significant correlation was found between the shortening of the FBUT, VBUT, and the worsening of the OSI (r = -0.33, P < 0.05). A reading session on a smartphone screen in healthy subjects was found to significantly affect the tear film stability and objectively worsen the retinal image quality.

Transmittance measurement of the in vivo human eye with a double-pass system

Purpose: To develop a methodology based on a double-pass system to obtain information about the transmittance of ocular media. Methods: The procedure consists of recording double-pass images at different powers of a laser diode of 780 nm and determining the scattering in an area between 25–35 arcmin of each image. The scattering showed linear behavior in respect to the irradiance of the laser, and the slope of the linear fit was proportional to the transmittance squared of the media evaluated. An artificial eye with different filters was tested first. Then, fifteen subjects with clear ocular media were divided into two groups: ten subjects classified by the iris color were recruited for the measurements of an ocular transmittance index and the estimation of the transmittance (group A), and another five subjects were selected for measurements with neutral filters (group B). Results: The measurements performed in group A presented a mean transmittance of 42.95%. No differences in the transmittance were found between subjects with different iris color (p = 0.154). Measurements in group B showed a good correlation (r = 0.959, p &lt; 0.001) between the expected and the measured value for the transmittance. Conclusion: We proposed and evaluated a method to determine the transmittance of the eye in vivo using the double-pass system.

Agreement between subjective and predicted high and low contrast visual acuities with a double-pass system.

To evaluate the agreement between subjective high and low contrast visual acuity (VA) and predicted values from double-pass system measurements in healthy candidates to laser refractive surgery. Ninety-two eyes measured during the preoperative screening to laser refractive surgery were included in this retrospective analysis. High contrast subjective visual acuity (HCVA) and low contrasts at 20% (LCVA20) and 9% (LCVA9) were compared with the predicted VA obtained with a commercial double-pass system (OQAS) at the same levels of contrast, 100% (OV100), 20% (OV20), and 9% (OV9). The agreement was evaluated with Bland-Altman analysis computing the limits of agreement (LoAs) and the correlations with the spearman rho. An underestimation of VA was obtained with the double-pass system for the highest contrast. Differences between predictive and subjective measurements were statistically significant for 100% contrast (- 0.08 logMAR, p < 0.0005), but not for 20% (- 0.03 logMAR, p = 0.07) and 9% (- 0.02 logMAR, p = 0.9) of contrasts. The LoAs increased with the decrease of contrast from 0.29 with 100% to 0.39 logMAR with 9% of contrast. A weak correlation was obtained between subjective and predicted VA (rho ≤ 0.33) that was only significant for 100% (p = 0.001) and 20% (p = 0.004) contrasts. Mean differences between methods were reasonably small so mean results obtained for predicted VA in OQAS studies can be considered as reliable, at least in healthy subjects and for low contrast. However, limits of agreement were considerably poor which means that OQAS cannot replace individual subjective measurements of VA in clinical practice.

The Hybrid (PVT) Double-Pass System with a Mixed-Mode Solar Dryer for Drying Banana

In this paper, the hybrid PVT double pass system with a mixed-mode solar dryer type under forced convection has been designed, fabricated and installed for drying crops. The dryer was tried by drying 300 grams of banana slices in the air temperature of dryer range from 43.2 to 60.2°C. The initial moisture rate of banana was about 78% and the most dropped in moisture content was from 78% to 33% after 8 hours of the drying process. The banana slices are distributed in two identical trays and it was noticed that the most and least decreasing in weight of banana samples was from 150 to 48 gram and from 150 to 55 gram in lower and upper tray respectively, when the mass flow rate as 0.031 and 0.017 kg/s, which means that the high reduction was 68% of weight banana at a high mass flow rate of airflow. The critical parameter such as temperature distribution of the PVT with dryer room, useful heat gain, and thermal efficiency are computed by using the MATLAB 2015b program built for this purpose. The optimum useful heat gain and thermal efficiency were reached 423.7 and 52.98% respectively when the solar radiation 1190 and the mass flow rate of 0.031 kg/s.