scholarly journals LED Luminaires: Many Chips—Many Photometric and Lighting Simulation Issues to Solve

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4646
Author(s):  
Krzysztof Skarżyński ◽  
Wojciech Żagan ◽  
Kamil Krajewski
Keyword(s):  
Coordinate System ◽  
Optical Model ◽  
The Other ◽  
Practical Applications ◽  
Simulation Process ◽  
Key Issues ◽  
Lighting Simulation ◽  
Test Distance ◽  
Traditional Understanding ◽  
Led Luminaire

Currently, built LED luminaires are usually multi-source. This causes a large number of photometric and simulation problems connected with computer lighting visualization. This paper highlights three key issues with these luminaires: a change in the traditional understanding of the coordinate system for these luminaires, the photometric test distance of these luminaires and the need for the photometric separation of a single LED in the computer lighting simulation process. An optical model of a linear LED luminaire used in floodlighting was formulated on this basis. The presented conclusions refer to practical applications. Thus, it is necessary to address the crucial points that specify the coordinate system for the multi-source LED luminaire by its designer and present the information in a datasheet. The other important points concern determining the appropriate photometric test distance for the multi-source LED luminaires of a given type and creating photometric files for the different distances in the operation of the luminaire. Taking the above ideas into account will lead to an improvement in the quality and accuracy of lighting measurements and simulations.

scholarly journals Preparation and photocatalytic performance of metallic Nb0.9Ta0.1S2/2D-C3N4 composite

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Hanxiang Chen ◽  
Jianjian Yi ◽  
Zhao Mo ◽  
Yanhua Song ◽  
Wenshu Yang ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Low Cost ◽  
Metal Sulfide ◽  
Electron Hole ◽  
Practical Applications ◽  
Energy And Environment ◽  
Photocatalytic Application ◽  
Light Utilization ◽  
Ternary Metal ◽  
Key Issues

Abstract Photocatalysis technology has potential application in the field of energy and environment. How to expand visible light utilization and promote the separation efficiency of the carriers are the key issues for the high active photocatalysts preparation and future practical applications. In this work, a ternary metal sulfide Nb0.9Ta0.1S2 was prepared and used as an electron collector in the photocatalytic application. As a result, the generated electrons are quickly transferred to the surface of the composite to participate in the reaction. It was demonstrated that the photocatalytic activity of 2D-C3N4 was enhanced after the modification of Nb0.9Ta0.1S2. The Nb0.9Ta0.1S2/2D-C3N4 composite material was synthesized by solvothermal method. The composition of 5% Nb0.9Ta0.1S2/2D-C3N4 showed the highest H2 evolution rate of 1961.6 μmolg−1h−1, which was 6.6 times that of 2D-C3N4. The 15% Nb0.9Ta0.1S2/2D-C3N4 exhibited the best activity in Rhodamine B degradation rate of 97% in 2 h, which is 50% higher than that of 2D-C3N4. Nb0.9Ta0.1S2/2D-C3N4 can be used as electron trap to promote the effective separation of electron–hole pairs. This work provides benchmarks in exploring low-cost and efficient cocatalyst.

scholarly journals Radiation-Induced Asymmetric Grafting of Different Monomers into Base Films to Prepare Novel Bipolar Membranes

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2028
Author(s):  
Shin-ichi Sawada ◽  
Yasunari Maekawa
Keyword(s):  
Acrylic Acid ◽  
Anion Exchange ◽  
Graft Polymerization ◽  
The Other ◽  
Practical Applications ◽  
Bipolar Membranes ◽  
Graft Polymers ◽  
Grafting Reactions ◽  
Radiation Induced

We prepared novel bipolar membranes (BPMs) consisting of cation and anion exchange layers (CEL and AEL) using radiation-induced asymmetric graft polymerization (RIAGP). In this technique, graft polymers containing cation and anion exchange groups were introduced into a base film from each side. To create a clear CEL/AEL boundary, grafting reactions were performed from each surface side using two graft monomer solutions, which are immiscible in each other. Sodium p-styrenesulfonate (SSS) and acrylic acid (AA) in water were co-grafted from one side of the base ethylene-co-tetrafluoroethylene film, and chloromethyl styrene (CMS) in xylene was simultaneously grafted from the other side, and then the CMS units were quaternized to afford a BPM. The distinct SSS + AA- and CMS-grafted layers were formed owing to the immiscibility of hydrophilic SSS + AA and hydrophobic CMS monomer solutions. This is the first BPM with a clear CEL/AEL boundary prepared by RIAGP. However, in this BPM, the CEL was considerably thinner than the AEL, which may be a problem in practical applications. Then, by using different starting times of the first SSS+AA and second CMS grafting reactions, the CEL and AEL thicknesses was found to be controlled in RIAGP.

Total Productive Maintenance: Competing or Complementary to other Initiatives?

2013 ◽  
Vol 315 ◽  
pp. 472-476
Author(s):  
Adnan Hj. Bakri ◽  
Abdul Rahman Abdul Rahim ◽  
Noordin Mohd Yusof
Keyword(s):  
Large Scale ◽  
Manufacturing Industry ◽  
Short Review ◽  
The Other ◽  
Total Quality ◽  
Total Productive Maintenance ◽  
Quality Initiatives ◽  
Practical Applications ◽  
Manufacturing Organization

The objective of this short review paper is to examine the practical applications of Total Productive Maintenance (TPM) in the manufacturing industry. In this short review, an attempt was made to critically discuss the previous literatures related to TPM with the other established quality initiatives in the manufacturing, such as Total Quality Management (TQM) and Just-In-Time practice (JIT). This literature review-based research revealed an important research gaps related to TPM. The significance role of TPM as an important complementary to either TQM or JIT initiative is observed not been well addressed in the available literatures. Most of the researches available investigate these initiatives separately, focuses on the other element rather than addressing on the significant role of TPM as one of the main thrust. The separate implementation of such quality initiatives in the manufacturing organization means the requirement of large scale human, financial and technical resources as well the associated problems of running competing project in the company. The outcomes from this review justify the needs of further research in the area of TPM integration with other available initiatives, to further enhance its methodology aimed at solidifying its philosophy towards more realistic practical applications.

Effect of Specimen Geometry on the Predicted Mechanical Behavior of Polyethylene Pipe Material

2014 ◽  
Author(s):  
Tarek M. A. A. El-Bagory ◽  
Tawfeeq A. R. Alkanhal ◽  
Maher Y. A. Younan
Keyword(s):  
Mechanical Behavior ◽  
Longitudinal Direction ◽  
Primary Objective ◽  
The Other ◽  
Pipe Material ◽  
Ring Specimen ◽  
Design Data ◽  
Practical Applications ◽  
Other Hand ◽  
Gauge Section

The primary objective of the present paper is to depict the mechanical behavior of high density polyethylene, (HDPE), pipes under different loading conditions with different specimen geometries to provide the designer with reliable design data relevant to practical applications. Therefore, it is necessary to study the effect of strain rate, ring configuration, and grip or fixture type on the mechanical behavior of dumb-bell-shaped, (DBS), and ring specimens made from HDPE pipe material. DBS and ring specimens are cut from the pipe in longitudinally, and circumferential (transverse) direction respectively. On the other hand, the ring specimen configuration is classified into two types; full ring, (FR), and notched ring, (NR) (equal double notch from two sides of notched ring specimen) specimens according to ASTM D 2290-12 standard. Tensile tests are conducted on specimens cut out from the pipe with thickness 10 mm at different crosshead speeds (10–1000 mm/min), and ambient temperature, Ta = 20 °C to investigate the mechanical properties of DBS, and ring specimens. In the case of test specimens taken from longitudinal direction from the pipe a necking phenomenon before failure appears at different locations along the gauge section. On the other hand, the fracture of NR specimens occurs at one notched side. The results demonstrated that the NR specimen has higher yield stress than DBS, and FR specimens at all crosshead speeds. The present experimental work reveals that the crosshead speed has a significant effect on the mechanical behavior of both DBS, and ring specimens. The fixture type plays an important role in the mechanical behavior for both FR and NR specimens at all crosshead speeds.

scholarly journals AgFact: Linking farmers with facts

1997 ◽  
pp. 145-147
Author(s):  
G.I. Ogle ◽  
A.L. Craigie ◽  
M.J. Baker
Keyword(s):  
Service Sector ◽  
The Other ◽  
Information Need ◽  
End User ◽  
Information Base ◽  
The Public ◽  
High Profile ◽  
Key Issues ◽  
Distribution Chain

The AgLINK bulletin series dominated all agricultural and horticultural information publications from the late 1960s to the late 1980s, when it was discontinued. The collapse of such a high profile series raises questions about the viability of such a mechanism for linking farmers with facts. This failure highlights three key issues: the need to define and allocate the costs based on who benefits; the appropriate positioning of parties within the distribution chain; and a quality specification to which bulletins must adhere. We consider that AgFACT, the AgResearch pastoral agriculture information base which superseded AgLINK in 1997, should largely be cost neutral to science groups in AgResearch. However, the resources for providing information need to be met by science programmes, a cost which is outweighed by the opportunity to communicate with science stakeholders. The costs of distribution and retail need to fall with the other parties who benefit from the dissemination of this information - the retailer and the end user. We also consider that the role of AgResearch is in manufacture rather than sales to the public, which is best done by the agricultural service sector. AgFACT must maintain tight specifications, to ensure that it is relevant to farmers and other users, accurate and unbiased, and up to date. The penalty for not doing so is a loss of value and, moreover, a risk of it becoming a public liability. Keywords: AgFACT, AgLINK, agricultural information, information base, technology transfer

German Eugenics and the Wider World: Beyond the Racial State

2012 ◽  
Author(s):  
Paul Weindling
Keyword(s):  
Public Health ◽  
Welfare State ◽  
Ethnic Groups ◽  
Urban Growth ◽  
The Other ◽  
Racial Hygiene ◽  
Key Issues ◽  
Rapid Industrialization ◽  
The Individual ◽  
Size And Structure

This article discusses German eugenics as being incorporated of two strands, one racially oriented and the other welfare oriented. Eugenics in Germany was also characterized by its intention to reach out to a wider world of German colonies and German ethnic groups beyond the frontiers of the state. Key issues such as rapid industrialization and urban growth and associated changes in morbidity, family size and structure, and sexuality are addressed. The article outlines a system of public health in which eugenically-trained physicians served the race and nation rather than merely the individual. It provides an understanding of racial hygiene within the context of German imperialism, but the postwar loss of colonies, of territories to the new Polish state, creates a shift of focus within the new welfare state.

A numerical approach for simulating two-dimensional dense-snow avalanches in global coordinate systems

2021 ◽  
Author(s):  
Daniel Zugliani ◽  
Giorgio Rosatti ◽  
Stefania Sansone
Keyword(s):  
Coordinate System ◽  
Finite Volume ◽  
Reference System ◽  
Source Term ◽  
Numerical Approach ◽  
The Other ◽  
Snow Avalanche ◽  
Two Dimensional ◽  
Snow Avalanches ◽  
Avalanche Models

<p>Snow avalanche models are commonly based on a continuum fluid scheme, on the assumption of shallow flow in the direction normal to the bed, on a depth-averaged description of the flow quantities and on different assumptions concerning the velocity profile, the friction law, and the pressure in the flow direction (see Bartelt et al, 1999, Barbolini et al., 2000, for an overview). The coordinate reference system is commonly local, i.e., for each point of the domain, one axis is normal to the bed while the other two axes lay in a tangent plane. When the bed is vertical and the flow is not aligned with the steepest direction (e.g., in case of a side wall), the flow depth is no longer defined considering the normal direction and the model based on the local coordinate system is no longer valid. In near-vertical conditions, numerical problems can be expected.</p><p>Another critical point, for numerical models based on finite volume schemes and Godunov fluxes, is the accurate treatment of the source term in case of no-motion conditions (persistence, starting and stopping of the flow) due to the presence of velocity-independent, Coulomb-type terms in the bed shear stress. </p><p>In this work, we provide a numerical approach for a Voellmy-fluid based model, able to overcome the limits depicted above, to accurately simulate analytical solutions and to give reliable solutions in other cases (Zugliani & Rosatti, 2021). Firstly, differently from the other literature models, the chosen coordinate reference system is global (an axis opposite the gravity vector and the other two orthogonal axes lay in the horizontal plane) and therefore, the relevant mass and momentum equations have been derived accordingly. Secondly, these equations have been discretized by using a finite volume method on a Cartesian square grid where the Godunov fluxes has been evaluated by mean of a modified DOT scheme (Zugliani & Rosatti, 2016) while source terms in conditions of motion have been discretized by using an implicit operator-splitting technique. Finally, a specific algorithm has been derived to deal with the source term to determine the no-motion conditions.  Several test cases assess the capabilities of the proposed approach.</p><p> </p><p><strong>References:</strong></p><p>Barbolini, M., Gruber, U., Keylock, C.J., Naaim, M., Savi, F. (2000), <em>Application of statistical and hydraulic-continuum dense-snow avalanche models to five real European sites.</em> Cold Regions Science and Tech. 31, 133–149.</p><p>Bartelt, P., Salm, B., Gruber, U. (1999), <em>Calculating dense-snow avalanche runout using a voellmy-fluid model with active/passive longitudinal straining.</em> Journal of Glaciology 45, 242-254.</p><p>Zugliani D., Rosatti G. (2021), <em>Accurate modeling of two-dimensional dense snow avalanches in global coordinate system: the TRENT2D<sup>❄</sup> approach. </em>Paper under review.</p><p>Zugliani, D., Rosatti, G. (2016), <em>A new Osher Riemann solver for shallow water flow over fixed or mobile bed</em>, Proceedings of the 4th European Congress of the IAHR, pp. 707–713.</p>

Zero Knowledge Proofs

2018 ◽  
pp. 111-123 ◽  
Author(s):  
Kannan Balasubramanian ◽  
Mala K.
Keyword(s):  
Real World ◽  
The Other ◽  
Interactive Proof ◽  
Zero Knowledge ◽  
Practical Applications ◽  
Proof Of Knowledge ◽  
Real World Applications ◽  
Special Case ◽  
Zero Knowledge Proof

Zero knowledge protocols provide a way of proving that a statement is true without revealing anything other than the correctness of the claim. Zero knowledge protocols have practical applications in cryptography and are used in many applications. While some applications only exist on a specification level, a direction of research has produced real-world applications. Zero knowledge protocols, also referred to as zero knowledge proofs, are a type of protocol in which one party, called the prover, tries to convince the other party, called the verifier, that a given statement is true. Sometimes the statement is that the prover possesses a particular piece of information. This is a special case of zero knowledge protocol called a zero-knowledge proof of knowledge. Formally, a zero-knowledge proof is a type of interactive proof.

Rebirth and Redeath

2020 ◽  
pp. 73-81
Author(s):  
Nicolas Bommarito
Keyword(s):  
The Other ◽  
Central Problem ◽  
Other Hand ◽  
Traditional Understanding

This chapter discusses the cycle of birth and death in Buddhism. It is important to distinguish rebirth from reincarnation. Reincarnation is the transfer of a soul from body to body. Rebirth, on the other hand, is a cycle of many births and deaths, without any soul linking them. It is commonly called rebirth but it could equally well be redeath since each lifetime involves both a birth and a death. In many traditional forms of Buddhism, this cycle of rebirth and redeath includes supernatural being and places. Many traditional Buddhists think of these places and beings as real. In fact, this is central to many traditional statements of the central problem Buddhism aims to solve; these different kinds of lives all make up what is called samsara. Beings are constantly being born and dying in these different realms, over and over and over. On this traditional understanding, Buddhism solves the problem by ending this cycle of birth and death. The solution, sometimes called nirvana, is about getting out of the cycle.

Part III The right To Terminate, 8 Express Rights of Termination

2020 ◽  
Author(s):  
Stannard John E ◽  
Capper David
Keyword(s):  
Common Law ◽  
The Other ◽  
General Law ◽  
Key Issues ◽  
The Right ◽  
The Relationship

This chapter discusses express rights of termination. It is not always easy for a party to know for certain whether they are entitled to terminate or not. This is particularly so where the right in question depends on proof of fundamental breach or repudiation. For this reason, parties to a contract frequently, in the interests of certainty, make express provision for this by agreeing in advance that one or both of them may terminate if certain conditions are met. Such express rights of termination can depend on a wide variety of contingencies, but very frequently these will include a breach by the other party. Where this is the case, it is often difficult to distinguish termination under the express right from termination under the general law, particularly where the latter involves termination for breach of condition. The chapter then assesses four key issues with regard to express rights of this sort, most notably: (1) the relationship between express rights of termination and conditions at common law; (2) the requirements for the exercise of such rights; (3) the effect of termination under such a right; and (4) the problem of concurrent rights of termination.

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