Large Stokes shift downshifting organolanthanide complex,Eu(tta)3phen, is examined for inclusion in polymeric layers to replace the UVblocking layer in dye sensitized solar cell (DSSC) technology. The UV blocking layer increases stability but power conversion efficiency decreases as incident UV photons are not converted into photocurrent. Eu(tta)3phen doped polymeric film are prepared and atta…
Thermoelectric materials have attracted increasing attention because of their importance in applications such as energy harvesting and electronic cooling devices. [ 1–4 ] The performance of the thermoelectric devices is determined by the fi gure of merit,ZT , defi ned as ZT = S 2 σT / κ , where S is the Seebeck coeffi cient;σ , the electric conductivity; κ , the thermal conductivity; and …
Graphene is a material with enormous potential for numerous applications. Therefore, significant efforts are dedicated to large-scale graphene production using a chemical vapor deposition (CVD) technique. In addition, research is directed at developing methods to incorporate graphene in established production technologies and process flows. In this paper, we present a brief review of available…
This study investigates the esterification of hydrolyzed sea mango (Cerbera odollam)oil using several cationic ion exchange resins. The best resins were selected based on their performance in a preliminary esterification process. The best resins were then subsequently used in the optimization of the process parameters.The esterification parameters studied were reaction temperature (40–160°C)…
Animalmodels are important tools to predict human in vivo percutaneous absorption/penetration. Monkey, pig, rat, rabbit,guinea pig, hairless rodents, such as hairless rat, hairless mouse, hairless guinea pig and hairless dog, are among the most used animals for this purpose. Each animal model has its own advantages and weakness or limitation. To better correlate animal data with human skin abso…
Light quality shows strong effects on humans in many aspects, including aesthetics, psychology, physiology, and health. By assuming that natural light has the best light quality, devising a pseudo-natural light is hence important and critical. Here, an all-weather pseudo-natural light is demonstrated based on a high number of broad-band emitters. By doping six broad-band organic light-emitting…
In this book, we introduce the following: – A concept of basic language; a descriptive language of simple form in which it is possible to formulate recorded facts. The semantics of this basic language make it possible to clarify the links between linguistic, conceptual, and real entities of the application domain of a physical theory. – A new concept of idealization. We know that practica…
Part 2 of A Guide to Physics Problems contains problems from written graduate qualifying examinations at many universities in the United States and, for comparison, problems from the Moscow Institute of Physics and Technology, a leading Russian Physics Department. While Part 1 presented problems and solutions in Mechanics, Relativity, and Electrodynamics, Part 2 offers problems and solutio…
The written qualifying examination, a little publicized requirement of graduate physics programs in most universities, brings some excitement to the generally dull life of the graduate student. While undergoing this ordeal ourselves, we were reminded of the initiation ceremonies into certain strict monastic orders, designed to cause the novices enough pain to make them consider their vocation s…
In the Preface to the previous edition, we posed questions regarding trends in engineering education and practice, and whether the discipline of heat transfer would remain relevant. After weighing various arguments, we concluded that the future of engineering was bright and that heat transfer would remain a vital and enabling discipline across a range of emerging technologies including but …
Since the last edition, fundamental changes have occurred, both nationally and globally, in how engineering is practiced, with questions raised about the future of the profession. How will the practice of engineering evolve over the next decade? Will tomorrow’s engineer be more valued if he is a specialist, or more handsomely rewarded if she has knowledge of greater breadth but less depth…
This book is intended for junior and senior engineering students who are interested in learning some fundamental aspects of fluid mechanics. We developed this text to be used as a first course. The principles considered are classical and have been well-established for many years. However, fluid mechanics education has improved with experience in the classroom, and we have brought to bear in…
In this fifth edition we have retained the objectives of the first four editions: * to present a thorough treatment of engineering thermodynamics from the classical viewpoint, * to provide a sound basis for subsequent courses in fluid mechanics and heat transfer, and * to prepare students to use thermodynamics in engineering practice. While the fifth edition retains the basic organizati…
Dwell duration of multiple-injection scheme is an important parameter, which makes it possible to shift the tradeoff curve between soot and NOx closer to the origin. In this investigation, therefore, energy and exergy analyses are carried out for various two-step injection schemes in which 25% of the total fuel is injected during the second pulse and the dwell time is increased from 5°CA (cran…
The increasing importance of the Cu(In,Ga)Se2 based thin films photovoltaic industry claims for the development of new assessment and monitoring tools to answer the needs existing in the improvement of the control of the processes involved in the production of solar cells modules. In this frame, a strong interest has been given to the development methodologies for the assessment of the CIGS ab…
In April 2011, we published the first peer-reviewed analysis of the greenhouse gas footprint (GHG) of shale gas, concluding that the climate impact of shale gas may be worse than that of other fossil fuels such as coal and oil because of methane emissions. We noted the poor quality of publicly available data to support our analysis and called for further research. Our paper spurred a large incr…
In this paper, single molecule spectroscopy is used to probe the photophysical heterogeneity of near-infrared emitting silver nanoclusters stabilized in single stranded DNA containing 24 cytosines (C24-AgNCs). Focusing on this subset of emitters allows us to address and correlate their photophysical parameters. The results suggest that for these near-infrared emitting C24-AgNCs, the broad rang…
Ultrasound-assisted transesterification of refined palm oil (RPO) and crude palm oil (CPO) to produce biodiesel using a palm oil mill fly ash supported calcium oxide (CaO) catalyst is studied in this work. The reaction time is significantly reduced from a maximum of 360 min under conventional mixing to just 30 min with the use of ultrasound. Under ultrasonic cavitation, the required catalyst lo…
Photodetectors play key roles in many applications such as remote sensing,night vision, reconnaissance, medical imaging, thermal imaging, and chemical detection. Several properties such as performance, reliability, ease of integration, cost, weight, and form factor are all important in determining the attributes of photodetectors for particular applications. While a number of materials have be…
Recently, organic-based lead halide perovskites have received much attention for their high performance as light absorbers in thin-fi lm solar cells. [ 1–8 ] They exhibit not only a high optical absorption coeffi cient, optimal bandgap, and long electron/hole diffusion lengths, [ 9,10 ] which are advantageous for solar cells, but also good optical and electrical transport properties,making th…
Most animal experiments on cosmetics safety are prohibited and since March 2013, this obligation includes sensitization tests. However, until now there has been no validated alternative in vitro method. In this work, 400 compounds used in the cosmetic industry were selected to cover the greatest diversity of structures, biological activities and sensitizing potential.Thesemolecules were submit…
First reported by Farnum as much as 40 years ago, diketopyrrolopyrroles (2,5-dihydropyrrolo[4,3- c ]pyrrolo-1,4-diones) are currently one of the most widely used dyes, with applications that span high-quality pigments, fi eldeffect transistors, bulk-heterojunction solar cells, dye-sensitized solar cells,and fl uorescence imaging. Due to the breadth of their utility, there have been several foc…
Offshore and near-shore wind energy is one of the major renewable energy resources, which already make a substantial contribution to the energy supply in Europe. Nevertheless, development is still in the start-up phase, with new projects being planned and implemented continuously. This development needs to be informed, to enable deployment at the most suitable/ideal locations.However, in order…
In this study, three different kinds of simultaneous saccharification and fermentation (SSF) of washed pretreated corn stover with water-insoluble solids (WIS)content of 20% were investigated to find which one resulted in highest ethanol yield at high-solids loadings. The different methods were batch SSF, prehydrolysis followed by batch SSF and fed-batch SSF. Batch-SSF resulted in an ethanol y…
The human brain, with all its complexity, relies on an interconnected network of organic biological microfi bers, known as neurons, which facilitate the propagation of information across the body. Through the use of electrical action potentials, these signals are processed using different spatio-temporal principles (Figure S1, Supporting Information) that rely on the biochemical nature of axons…
Fluid mechanics is an exciting and fascinating subject with unlimited practical applications ranging from microscopic biological systems to automobiles, airplanes, and spacecraft propulsion. Fluid mechanics has also historically been one of the most challenging subjects for undergraduate students because proper analysis of fluid mechanics problems requires not only knowledge of the concept…
A study, entitled “Wabamun Lake Sequestration Project” or “WASP,” was performed to evaluate large-scale CO2 storage opportunities in the Wabamun area including potential risks. The project examined the feasibility of storing 20 megatons (Mt) of CO2 per year over 50 years. This scale is one order of magnitude larger than the typical benchmark (1 Mt/year) used in academic research and co…
In this paper, we demonstrate a two-step laser crystallization process for thin film silicon solar cells on glass. In a first step a 5mm thick amorphous silicon layer is crystallized by a diode laser to get the absorber. The multicrystalline layer consists of grains with sizes in the range of 1mmto 10mm. In a second step a thin amorphous silicon layer is epitaxially crystallized by an excimer l…
There is tremendous interest in one-dimensional nanostructures, since they permit enhanced properties as well as new paradigms for electronic, optical,optoelectronic, and photonic devices. Besides inorganic systems, nanowires (NWs) and nanotubes (NTs) containing an optically active polymer are now being intensively investigated. This article reviews recent developments in the various preparati…
Graphene quantum dots (GQDs) have attracted a great deal of interest from the viewpoints of both fundamental studies and applications. Photoluminescence (PL) is one of the intriguing properties of GQDs, however, the mechanism of the PL in GQDs is not fully understood. In the present study, a drastic change in the PL from UV to red light region is reported among GQDs separated by size-exclusion …
The growth of a multicrystalline silicon (mc-Si) ingot for solar cell applications was attempted using a Liquinert quartz crucible. A mc-Si ingot was also grown in a quartz crucible coated with Si3N4 powder for comparison with that from the Liquinert quartz crucible. The mc-Si ingot grown in the Liquinert quartz crucible had a shinier surface which has few impurity particles and higher minority…
Aluminum-doped zinc oxide (AZO) thin films are prepared by a low temperature (100 8C) aqueous solution deposition method with a subsequent UV post-deposition treatment at 140 8C. Film growth is governed by the retrograde solubility of zinc–ammine complexes at basic conditions (pH 11.4). Aluminum was introduced into the film as a dopant by co-precipitation, either using an aluminum metal foil …
One of the original dreams of three-dimensional (3D) dielectric photonic crystals has been to provide a 3D “designer electromagnetic vacuum”, which would allow tailoring of the spontaneous emission from emitters such as two-level systems, atoms,molecules, defects, or quantum dots located inside this artifi cial environment. This idea opens a wealth of opportunities. [ 1–3 ] For example, i…
The one-step selective oxidation of methanol to dimethoxymethane (DMM)was demonstrated over titania-supported molybdenum oxide catalysts, containing different amounts of molybdenum and prepared using two different impregnation techniques, namely wet impregnation and incipient wetness impregnation. The corresponding catalysts exhibited both acidic and redox properties, which are necessary for t…
This work reports the synthesis of photovoltaic-grade Cu2ZnSnSe4 thin films with Zn-poor compositions (Zn/ Sn
Fluid mechanics is concerned with the behaviour ofliquids and gases at rest and in motion. The proper understanding of mechanics of fluids is important in many branches of engineering: in biomechanics the flow of blood is of interest; ocean currents require a knowledge of fluid mechanics; chemical processing of plants require a thorough knowledge of fluid mechanics; aeronautical engineers requi…
Large-scale structural color fl exible coatings have been hard to create, and patterning color on them is key to many applications, including large-area strain sensors, wall-size displays, security devices, and smart fabrics. To achieve controlled tuning, a micro-imprinting technique is applied here to pattern both the surface morphology and the structural color of the polymer opal fi lms (POF…
The purpose of this article is to study the impact of oxyfuel combustion applied to a rotary kiln producing lime. Aspects of interest are product quality, energy efficiency, stack gas composition, carbon dioxide emissions, and possible benefits related to carbon dioxide capture. The method used is based on multicomponent chemical equilibrium calculations to predict process conditions. A generic…
In this work, pneumatic spray pyrolysis was used to deposit Cu2ZnSnS4 kesterite thin film layers onto soda lime glass substrates/Mo coated substrates (substrate configuration).Furthermore, pneumatic spray pyrolysis was also tested as a potential way to grow kesterite thin film layers on ZnO nanorod arrays on SnO2:F coated glass substrates (superstrate cell configuration). In this case semi-tr…
Technological applications increasingly demand materials with sophisticated features and improved functionalities. In this context, multifunctional materials (MFMs) are especially attractive as they are often capable of responding to different physical,chemical and/or biological stimuli. A particularly useful property that has been incorporated into MFMs is the shapememory effect (SME), which w…
In recent years, research about the application and optimization of PV panels has grown rapidly. Especially for stand-alone solar systems there have been some problems related to first stages of design and application. Finding the optimum slope of PV panels in order to maximize the absorbed solar radiation is considered as one of the major obstacles. Although in Malaysia there have been some r…
Layered transparent photonic stacks are known to give rise to highly brilliant color in a variety of living organisms. [ 1 ] The biomimetic replication of these structures not only offers a wide range of applications, but can also be used as a tool to gain understanding of the biological processes responsible for the self-assembly of these structures in nature. Recent studies showed that cellul…
Optical sensing from the ultraviolet (UV) to the near infrared (NIR) range have broad applications including imaging, telecommunications,biomedicine, environmental monitoring and defence sensing. [ 1–3 ] It is desirable to have a photodetector with a response spectrum covering a broad spectral range from UV to NIR. However, commercially available solid-state photodetectors have relatively nar…
The gyroid is a continuous and triply periodic cubic morphology which possesses a constant mean curvature surface across a range of volumetric fi ll fractions. Found in a variety of natural and synthetic systems which form through self-assembly, from butterfl y wing scales to block copolymers, the gyroid also exhibits an inherent chirality not observed in any other similar morphologies. These …
Plasmonic metasurfaces are investigated that consist of a sub-wavelength line pattern in an ultrathin (∼10 nm) silver fi lm, designed for extraordinary suppressed transmission (EOST) in the visible spectral range. Measurements with a near-fi eld scanning optical microscope (NSOM) demonstrate that farfi eld irradiation resonantly excites antenna-like (bright) modes that are localized on the m…
In this work we studied the interface growth upon deposition of indium-tin oxide (ITO) on amorphous hydrogenated Si (a-Si:H)/crystalline Si (c-Si) structures. The analysis methods used were X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) in combination with in situ film growth with magnetron sputtering. The analysis was complemented with transmission elec…
Structural, optical, and electrical properties of multilayer stacks ZnO:Al/Ag/ZnO:Al and ZrO2/Ag/ZrO2 are studied. The stacks are deposited on glass substrates without heating by consecutive r.f. magnetron sputtering of ZnO:Al and Ag or ZrO2 and Ag targets, respectively. The properties of samples as-deposited and annealed in forming gas atmosphere, at 180 8C for 1 h are compared. The structural…
Li-ion batteries are the powerhouse for the digital electronic revolution in this modern mobile society, exclusively used in mobile phones and laptop computers. The success of commercial Li-ion batteries i the 1990s was not an overnight achievement, but a result of intensive research and contribution by many great scientists and engineers. Then much efforts have been put to further improve the…
(Ga,In)N/GaN multiple quantum well blue light emitting diodes (LEDs) grown on mesa-patterned silicon substrates with improved electro-optic characteristics are demonstrated.The active regions are grown on top of high-reflectivity AlN/(Al,Ga)N distributed Bragg reflectors (DBRs). Due to efficient stress relaxation at the mesa edges, crack formation during growth or upon the post-growth coolingd…
The blocking problems in equipment and flowlines caused by precipitation of wax solids is a well-known problem and large research efforts have been focused on developing procedures dealing with wax deposition. Among the different alternatives, the use of chemicals is frequently used to inhibit wax precipitation.The presence of these compounds modifies the size and/or the shape of the paraffini…