scholarly journals Simulation of Concentrated Photovoltaic Cooling System

Solar Energy ◽  
2004 ◽  
Author(s):  
Christopher Halford ◽  
Robert F. Boehm
Keyword(s):  
Cooling System ◽  
Ambient Air ◽  
System Model ◽  
Pv System ◽  
Actual Performance ◽  
Backing Plate ◽  
Size Number ◽  
Fan Speed ◽  
The Individual ◽  
Selection Of

This paper reports work underway in converting a dish-Stirling system to a dish-PV system at UNLV. The existing SAIC dish–Stirling system is being retrofitted with new fixed-focus facets and an Amonix photovoltaic receiver to replace the Stirling engine/generator package. As is the case with photovoltaic systems generally, the Amonix cells being used in this application lose efficiency as their temperatures increase. To combat this effect, cooling is provided by circulating liquid through channels in the backing plate. The liquid is then pumped through an array of automotive type radiators and the excess heat is rejected to the ambient air. Reported here is the development of a numerical model for the cooling system, with specific attention being paid to the transient response. Experimental data is taken to determine the various properties of the individual components to be used in the system and this data is used in a MatLab-based simulation. The cooling system model can then be linked to a similar model for the receiver and cell assembly and the optimization functions included in MatLab can be used to select the input parameters (pump size, number of radiators, fan speed, etc.) that maximize the overall efficiency of the system. The predictions of the model can be used in the selection of the final cooling system design and the validity of the model can be checked against the actual performance of the unit.

Simulation and Optimization of a Concentrated Photovoltaic System

2005 ◽  
Vol 128 (2) ◽  
pp. 139-145 ◽  
Author(s):  
I. Mahderekal ◽  
C. K. Halford ◽  
R. F. Boehm
Keyword(s):  
Numerical Model ◽  
Conversion Efficiency ◽  
Cooling System ◽  
Photovoltaic System ◽  
Weather Data ◽  
Entire System ◽  
Simulation And Optimization ◽  
Size Number ◽  
Input Parameters ◽  
Fan Speed

Reported here is the development, using results of analysis and experiments, and optimization of a numerical model for a concentrated photovoltaic system. Models for the two major components of the system (cooling system and receiver) are developed separately from one another and then linked to simulate the performance for the entire system. The model is linked to yearly weather data and the optimization routines included in MATLAB are then used to select the input parameters (pump size, number of radiators, fan speed, etc.) which maximize the solar to electrical conversion efficiency of the system.

scholarly journals Basic design of a cooling system for nylon 6, 6 process

2018 ◽  
Vol 7 (3) ◽  
pp. 977
Author(s):  
Karthik Silaipillayarputhur Ph. D ◽  
Nasser Al Mulhim ◽  
Abdullah Al Mulhim ◽  
Mohammed Arfaj ◽  
Ahmed Al Naim
Keyword(s):  
Heat Exchanger ◽  
Rate Ratio ◽  
Cooling System ◽  
Ambient Air ◽  
Nylon 6 ◽  
Polymer Fibers ◽  
Basic Design ◽  
Quenching Process ◽  
Pre Treatment ◽  
Selection Of

The project concentrates on the basic design of a cooling system for rapidly cooling nylon 6, 6 polymer fibers using cold air. The ambient air after pre-treatment in the air-washer is available at 72°F all year round. Based on the company’s throughput, it is required to supply (quench) air at 58°F. Nylon 6, 6 polymer after thorough polymerization is distributed through 16 quench cabinets and each quench cabinet requires approximately 530 ft3/min (cubic feet per minute, CFM) of air. The project concentrates on the basic design of a cooling system wherein air at the required mass flow rate is supplied at 58°F for the quenching process. A basic design of the refrigeration cycle and heat exchangers were considered in this work. In the development of the basic design for heat exchanger, performance charts were developed. Performance charts describe the performance of the heat exchanger in terms of fundamental dimensionless parameters. Using performance charts it was clearly seen that increasing the number of transfer units (NTU) doesn’t necessarily increase the rate of heat transfer. Increasing the NTU beyond an optimum value is pointless and increases the capital cost of the heat exchanger. The preliminary design involves selection of appropriate NTU and capacity rate ratio for the heat exchanger. From the capacity rate ratio and NTU, it is fairly straight forward to extrapolate the detailed design for the heat exchanger. A cooling system model was developed for the design process and for the simulation of the cooling system.  

scholarly journals Enhancement of Poly-Crystal PV Panels Performance by Air-to-Air Heat Exchanger Cooling System

2021 ◽  
Vol 16 ◽  
pp. 157-163
Author(s):  
Khaleel Abushgair
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Ambient Air ◽  
Bottom Surface ◽  
Solar Panels ◽  
Pv System ◽  
System A ◽  
Pv Module ◽  
Back Panel ◽  
The Impact

The temperature of silicon Poly-Crystal photovoltaic (PV) solar panels has a significant impact on their efficiency emphasizing the necessity of cooling approach to be used. The current study looked at the impact of adopting a unique forced convictive air-to-air heat exchanger as a cooling approach to boost the efficiency of PV solar panels, as efficiency of silicon Poly-Crystal PV solar panels would decrease as its temperature increased. The research was carried out experimentally with both an uncooled and cooled PV system. A unique cooling system for PV panels was designed and experimentally investigated in Amman, Jordan included a heat exchanger connected to a blower that drove ambient air over the back-panel surface and a chimney to draw the cooled air outside. This cooling system would improve the PV panel's efficiency. It was found that by directing cooled air over the bottom surface of the PV module at an ideal rate of 0.01020 m3/s, the temperature of the PV module could be reduced from an average of 40 °C (without cooling) to 34 °C. As a result, the efficiency and output power of PV modules increased by roughly 2 % and 12.8 %, respectively.

Pengaruh Persepsi Kegunaan, Persepsi Kemudahan, Kecepatan, Keamanan 75 dan Kerahasiaan Serta Kesiapan Teknologi Informasi Wajib Pajak terhadap Penggunaan e-Filing Bagi Wajib Pajak Orang Pribadi Di Kota Tangerang, Kecamatan Karawaci

2016 ◽  
Vol 8 (1) ◽  
pp. 75-91 ◽  
Author(s):  
Shelby Devina ◽  
Waluyo Waluyo
Keyword(s):  
Ease Of Use ◽  
Perceived Usefulness ◽  
Security And Privacy ◽  
Primary Data ◽  
Perceived Ease Of Use ◽  
Analysis Technique ◽  
Convenience Sampling ◽  
The Individual ◽  
Tax Payers ◽  
Selection Of

The objective of this research was to examine the effect of perceived usefulness, perceived ease of use, speed, security and privacy and readiness technology tax payers information to e-Filing usage. The object of this study is the individual tax payers in Tangerang City, Karawaci District. The selection of the sample is determined based on convenience sampling method. Data used in this study was primary data, id est: questionnaires. The respondent in this study were 110. Data analysis technique in this study using multiple linear regression. The result of this study were (1) perceived usefulness have a significant impact towards e-Filing usage; (2) perceived ease of use have a significant impact towards e-Filing usage; (3) speed does not have a significant impact towards e-Filing usage; (4) security and privacy does not have a significant impact towards e-Filing usage; (5) readiness technology tax payers information does not have a significant impact towards e-Filing usage; (6) perceived usefulness, perceived ease of use, speed, security and privacy and readiness technology tax payers information all simultaneously, have a significant impact towards e-Filing usage. Keywords: e-Filing usage, perceived usefulness, perceived ease of use, readiness technology tax payers information, security and privacy.

PROBLEM ASPECTS OF THE IMPLEMENTATION OF CRIMINAL PROCEDURAL NORMS OF PROTECTION OF THE VICTIMS FROM CRIME

2020 ◽  
pp. 72-76
Author(s):  
Яна Валерьевна Самиулина
Keyword(s):  
Preventive Measure ◽  
Criminal Procedure ◽  
Legal Rights ◽  
Criminal Proceedings ◽  
Effective Mechanism ◽  
The Russian Federation ◽  
The Individual ◽  
The Right ◽  
To Receive ◽  
Selection Of

В настоящей статье предпринята попытка исследовать отдельные проблемные аспекты института потерпевшего в российском уголовном процессе. В этих целях подвергнуты анализу правовые нормы, регламентирующие его процессуальный статус. Раскрываются отдельные пробелы уголовно-процессуального законодательства в сфере защиты законных прав и интересов потерпевшего. Автор акцентирует внимание на том, что совершенствование уголовно-процессуального законодательства в части расширения правомочий потерпевшего по отстаиванию своих нарушенных преступлением прав следует продолжить. На основании проведенного исследования действующего законодательства в части регламентации прав потерпевшего от преступления предлагается расширить перечень получаемых им копий постановлений, указанных в п. 13 ч. 2 ст. 42 УПК РФ. Автор предлагает включить в перечень указанной законодательной нормы право получения потерпевшим копии постановления об избрании конкретного вида меры пресечения, избранного в отношении подозреваемого (обвиняемого). Для создания действенного механизма защиты интересов потерпевших от преступления юридических лиц предлагаем ч. 9 ст. 42 УПК РФ изложить в следующей редакции: «в случае признания потерпевшим юридического лица его процессуальное право в уголовном процессе осуществляет представляющий его профессиональный адвокат». This article attempts to investigate certain problematic aspects of the institution of the victim in the Russian criminal process. For this purpose, analyzed the individual norms governing his procedural status. Separate gaps of the criminal procedure legislation in the sphere of protection of the legal rights and interests of the victim are disclosed. The author emphasizes that the improvement of the criminal procedure legislation in terms of the extension of the victim’s authority to defend his rights violated by the crime should be continued. On the basis of the study of the current legislation regarding the regulation of the rights of the victim of a crime, it is proposed to expand the list of decisions received by him, referred to in paragraph 13, part 2 of article 42 Code of Criminal Procedure. The author proposes to include in the list of the indicated legislative norm the right to receive the victim a copy of the decision on the selection of a specific type of preventive measure, selected in relation to the suspect (accused). To create an effective mechanism for protecting the interests of legal entities victims of a crime, we offer part 9 of art. 42 of the Code of Criminal Procedure of the Russian Federation shall be reworded as follows: «if a legal entity is recognized as a victim, his procedural right in criminal proceedings is exercised by the professional lawyer representing him».

SAMUEL J. BROADS CONTRIBUTIONS TO THE ACCOUNTING PROFESSION

1996 ◽  
Vol 23 (2) ◽  
pp. 69-85 ◽  
Author(s):  
Gary John Previts ◽  
Thomas R. Robinson
Keyword(s):  
Self Regulation ◽  
Accounting Profession ◽  
General Acceptance ◽  
Accounting Principles ◽  
The Individual ◽  
Securities Laws ◽  
Analogous Reasoning ◽  
Independent Audit ◽  
Selection Of

In the decade following the passage of the Federal Securities Laws of 1933 and 1934, the reform of accounting and auditing practices directed authority for selection of accounting principles and auditing procedures away from the discretion of the individual accountant and auditor. Instead, a self-regulatory peer driven process to establish general acceptance for a more limited set of principles and procedures was being initiated. Two events which occurred in 1938 indelibly affected this process, the SEC's decision to issue Accounting Series Release No. 4, which empowered non-governmental entities as potential sources of authoritative support, and the McKesson & Robbins fraud which called into question the value of the independent audit and the role of external auditing at the very time a momentum had been established for self-regulation by the nascent and recently reunified accounting profession. The contributions of Samuel J. Broad in both the initiatives for self-regulation of accounting principles and of auditing procedures is examined in this paper. Further, several examples of Broad's rhetorical technique of employing analogous reasoning to facilitate dissemination of complex economic and accounting issues are examined.

Application of the turbidity ratio method in the spherical particle size determination in the range m ∈ and α ∈

1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann
Keyword(s):  
Refractive Index ◽  
Spherical Particle ◽  
Ratio Method ◽  
Refractive Indices ◽  
Relative Refractive Index ◽  
Particle Size Determination ◽  
The Individual ◽  
The Given ◽  
Turbidity Ratio ◽  
Selection Of

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.

Revising the Indications of Transtemporal Surgical Approaches in the Modern Endoscopic Era of Skull Base Surgery: A Dying Art

2020 ◽  
Author(s):  
Ravi Sankar Manogaran ◽  
Raj Kumar ◽  
Arulalan Mathialagan ◽  
Anant Mehrotra ◽  
Amit Keshri ◽  
...  
Keyword(s):  
Skull Base ◽  
Surgical Approach ◽  
Nerve Palsy ◽  
Tertiary Care ◽  
Surgical Approaches ◽  
Microsurgical Anatomy ◽  
Complete Excision ◽  
Lateral Skull Base ◽  
The Individual ◽  
Selection Of

Abstract Objectives The aim of the study is to emphasize and explore the possible transtemporal approaches for spectrum of complicated lateral skull base pathologies. Design Retrospective analysis of complicated lateral skull base pathologies was managed in our institute between January 2017 and December 2019. Setting The study was conducted in a tertiary care referral center. Main Outcome Measures The study focused on the selection of approach based on site and extent of the pathology, the surgical nuances for each approach, and the associated complications. Results A total of 10 different pathologies of the lateral skull base were managed by different transtemporal approaches. The most common complication encountered was facial nerve palsy (43%, n = 6). Other complications included cerebrospinal fluid (CSF) collection (15%, n = 2), cosmetic deformity (24%, n = 4), petrous internal carotid artery injury (7%, n = 1), and hypoglossal nerve palsy (7%, n = 1). The cosmetic deformity included flap necrosis (n = 2) and postoperative bony defects leading to contour defects of the scalp (n = 2). Conclusion Surgical approach should be tailored based on the individual basis, to obtain adequate exposure and complete excision. Selection of appropriate surgical approach should also be based on the training and preference of the operating surgeon. Whenever necessary, combined surgical approaches facilitating full tumor exposure are recommended so that complete tumor excision is feasible. This requires a multidisciplinary team comprising neurosurgeons, neuro-otologist, neuroanesthetist, and plastic surgeons. The surgeon must know precise microsurgical anatomy to preserve the adjacent nerves and vessels, which is necessary for better surgical outcomes.

scholarly journals Classifying the Biological Status of Honeybee Workers Using Gas Sensors

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 166
Author(s):  
Jakub T. Wilk ◽  
Beata Bąk ◽  
Piotr Artiemjew ◽  
Jerzy Wilde ◽  
Maciej Siuda
Keyword(s):  
Gas Sensors ◽  
Laboratory Tests ◽  
Test Chamber ◽  
Ambient Air ◽  
True Positive Rate ◽  
True Positive ◽  
Positive Rate ◽  
Parameters Of Accuracy ◽  
Selection Of

Honeybee workers have a specific smell depending on the age of workers and the biological status of the colony. Laboratory tests were carried out at the Department of Apiculture at UWM Olsztyn, using gas sensors installed in two twin prototype multi-sensor detectors. The study aimed to compare the responses of sensors to the odor of old worker bees (3–6 weeks old), young ones (0–1 days old), and those from long-term queenless colonies. From the experimental colonies, 10 samples of 100 workers were taken for each group and placed successively in the research chambers for the duration of the study. Old workers came from outer nest combs, young workers from hatching out brood in an incubator, and laying worker bees from long-term queenless colonies from brood combs (with laying worker bee’s eggs, humped brood, and drones). Each probe was measured for 10 min, and then immediately for another 10 min ambient air was given to regenerate sensors. The results were analyzed using 10 different classifiers. Research has shown that the devices can distinguish between the biological status of bees. The effectiveness of distinguishing between classes, determined by the parameters of accuracy balanced and true positive rate, of 0.763 and 0.742 in the case of the best euclidean.1nn classifier, may be satisfactory in the context of practical beekeeping. Depending on the environment accompanying the tested objects (a type of insert in the test chamber), the introduction of other classifiers as well as baseline correction methods may be considered, while the selection of the appropriate classifier for the task may be of great importance for the effectiveness of the classification.

scholarly journals Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Porcine Model ◽  
Animal Experiments ◽  
Radioactive Tracers ◽  
The Individual ◽  
Selection Of

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

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