Process Point Of View Research Articles

Fabrication of highly regular suspended graphene nanoribbons through a one-step electron beam lithography process

A method to obtain pre-oriented large longitudinal 1-D arrays of identical suspended graphene nanoribbons is presented. Mechanical exfoliation from graphite was done in order to deposit single- and multiple-layered graphene over a Polymethyl-Methacrylate (PMMA) substrate, which is used as a sacrificial material. Electron beam lithography (EBL) is used to define the anchors and the suspended part of the structures. The method allows achieving a high number of graphene suspended nanoribbons with a very regular width and length. The main advantage of the method, from the process point of view, with respect to other standard procedures is that only one EBL step is needed in the whole sequence, so that the overall process is extremely simplified.

Interview

Dr Dingyou Zhang of GLOBALFOUNDRIES talks about her research interests and the paper ‘BMD Impact on Silicon Fin Defect at TSV Bottom’, page 954. Dr Dingyou Zhang As the semiconductor industry strived to scale according to Moore's Law, the conventional planar ICs encountered many physical, technological and economic bottlenecks. 3D integration technology, by stacking and connecting function blocks in a vertical fashion, promises to alleviate such bottlenecks and has been widely investigated in recent years. The potential benefits of 3D integration include multi-functionality, increased performance, increased data bandwidth, reduced power, small form factor, reduced packaging, increased yield and reliability, flexible heterogeneous integration, and reduced overall costs. Performance improvement in 3D ICs is mainly due to reduction of interconnect length reducing interconnect delay and power consumption. Small form factor is achieved by stacking active device layers on top of one another. During my M.S. and Ph.D. I was working on several research topics related to 3D integration, including TSV thermal-mechanical reliability and a novel chip-to-wafer 3D integration approach. I joined GLOBALFOUNDRIES in 2013 and I am currently working on advanced packaging technologies in the office of the CTO, focusing on through-silicon via (TSV) technology. The TSV is an important enabling component in 3D integration; electrically connecting multiple strata of ICs using short vertical vias that pass through a thinned silicon wafer substrate in order to establish a connection between the active side and backside of the die. Compared to conventional wirebonding and flipchip stacking, TSVs enable high-performance, high functionality, compact heterogeneous systems with high data bandwidth and speed, and low power requirements by providing the shortest interconnect path and higher interconnect density, compactly. However, it is challenging to fabricate reliable TSVs and substantial research is being conducted on aspects including their design, processing materials, metrology development and thermal-mechanical reliability. We report a recently found silicon fin defect at TSV bottom which was identified as a killer defect. To examine the root cause of this defect, we explored different inspection options and finally developed an effective method to catch the defect post TSV deep reactive ion etch. This is compatible with inline inspection and can be easily verified by cross-sectioning the via. With this well-established inspection approach, we were able to further investigate various potential root causes of the defect, such as TSV density microloading, TSV location and photoresist residue impacts. After ruling out other effects, bulk micro defect (BMD) turned out to be a key root cause; based on both BMD simulation and experimental results. Thus a low BMD or non-BMD silicon substrate is recommended to reduce or eliminate this defect. The work provides a viable way to clear this roadblock for TSV manufacturability. This is a killer defect which is hard to detect due to its deep location at the bottom of high aspect ratio vias, it can cause yield loss and requires elimination. We have seen mechanical failures caused by this defect after assembling TSV chips. One example we show is a silicon fin defect at TSV bottom causing copper diffusion into silicon cracks in TSV vicinity, after wafer thinning and TSV backside reveal process. A desirable inspection point for using our SEM automatic process inspection is right after TSV etch. Post etch is the first step in which we found this silicon fin defect and it saves downstream manufacturing resources from processing defective TSVs. Post etch inspection results can be easily verified physically and correlated to silicon fin defects, since TSVs are not filled with metal yet. This inspection approach can be adopted after TSV etch and before photoresist ashing and clean, which has less Q time concerns than between TSV post etch clean and dielectric liner deposition. 3D integration is predicted to be a key technology to solve performance and cost problems of conventional IC fabrication in the ITRS roadmap, which will probably be based on TSV technology. Full 3D process flows have already been demonstrated with no major showstoppers from a design or process point of view. While cost reduction is still on the to-do list for high volume production, multiple equipment and material suppliers are focusing on optimising processes to lower costs. With a positive outlook for commercialisation, a strong demand for such future 3D IC applications including memories and processors is expected in the next few years.

Historical Review of Die Drool Phenomenon in Plastics Extrusion

Die drool phenomenon is defined as unwanted spontaneous accumulation of extruded plastics on die exit face(s) of extrusion die during plastics extrusion process. Such accumulated material builds up on die exit face(s) and frequently or continually sticks onto the extruded product and by this way reduces the quality of the product. When the die drool appears, the extrusion process must be shut down and the die exit face(s) must be manually cleaned, which is time consuming as well as money consuming. Die drool has been observed from the beginning of plastics extrusion and the first published remark about it was made in 1946. For a long time it was considered as only an engineering problem and even if a wide range of suppressing ideas based on modification of extrusion dies, plastics materials, and processing conditions have already been patented, its source remained unclear. During the last few years, a number of experimental as well as theoretical research papers focusing on its fundamental nature have been published. Nowadays, die drool is considered as a fundamental rheological phenomenon. The force which drives the building up of extruded plastics on die exit face(s) is negative pressure (suction) occurring in the die exit edge(s) region where the free surface of the extruded plastics is created. Moreover, two different die drool types (external and internal) exist. The formation mechanisms of external/internal die drool are based on negative pressure occurring in the die exit region together with deformation of free extrudate surface/material separation wherever inside the extrusion equipment, respectively. From the processing point of view, the internal die drool is much more problematic than the external one, primarily due to a higher build up rate and compact shapes of the accumulated drool mass. Two theories of internal die drool formation mechanism based on wall slip theories (flow-induced molecular weight fractionation and stress-induced cohesive chain disentanglement) have been recently proposed and tested. In this historically ordered review, breakthrough works in the field of die drool research are presented, many ways to suppress it are shown, techniques for its quantitative evaluation and experimental methods for its analytical investigation are introduced, external and internal die drool types are explained, and theories of external as well as internal die drool formation mechanism are presented and discussed in depth, which can be especially helpful for plastics extrusion experts as well as for the rheological community.

Signal Processing for Nondifferentiable Data Defined on Cantor Sets: A Local Fractional Fourier Series Approach

From the signal processing point of view, the nondifferentiable data defined on the Cantor sets are investigated in this paper. The local fractional Fourier series is used to process the signals, which are the local fractional continuous functions. Our results can be observed as significant extensions of the previously known results for the Fourier series in the framework of the local fractional calculus. Some examples are given to illustrate the efficiency and implementation of the present method.

An inquiry into unidirectionality as a foundational element of grammaticalization

This paper assumes that in order to explain rather than describe language change, historical linguists should not only consider what happens diachronically at the language output level but also, crucially, what speaker-listeners do at the processing level. The reason for this is that the structure of the language is shaped by the properties of the neurolinguistic mechanism underlying both language use and language learning. It will be argued that analogy as an important principle in grammar formation is the main mechanism in grammaticalization and in change in general when looked at from a processing point of view. The paper discusses the workings of analogy in a number of cases in the history of English which have traditionally been interpreted as unidirectional cases of grammaticalization . It will be shown instead that multiple source constructions were involved, which influenced one another and thus gave direction to the change.

CNC Machining Based on UG for Stamping Die of Waveform Spring

In this paper, for the large scale production demand of waveform spring, it combines UG advantage of complex surface modeling and computer numerical control (CNC) machining, uses this way of surface modeling method of bicubic B-spline to establish the stamping die geometry model for the need of waveform spring production. And from a process point of view, it analyzes the key issues of die CNC machining to achieve the selection of optimal small tool radius, tool path rational planning and rough finishing parameters set. The application results show that: the shape precision of die surface could meet the design requirements and could achieve the precision stamping of waveform spring.

The Impact of Web Sites on Teaching and Learning Mathematics

Abstract The contribution presents an overview and analysis of research results concerning the influence of Internet on mathematics teaching and learning. The studies have been divided into categories according to their research focus. The second part focuses on free web resources. Website functions are being discussed in comparison to textbooks from the learning process point of view. Based on the investigation of a range of websites, the benefits and risks associated with web sites use in mathematics instruction are stated. These include an analysis of some mathematical and didactical errors in these resources.

New Heart Failure Guidelines Improve Prognosis, Quality of Life

New Heart Failure Guidelines Improve Prognosis, Quality of Life

Comprehensive Planning Materials and Products of Pars Khazar Industrial Company

In the last two decades wonderful changes is formed about technology information and computer systems that this matter causes the change of old view and the orient activity structure and gives its place to process point of view. According toviewand process management of all steps required to reach a conclusion considered as chain and therefore will be tried to create uniformity between existing capacities And all steps necessary to strengthen the efficiency and effectivenessof processes. Accomplishing thisonthecurrentindividualmembers of asupply chainplanning, control and coordination ofthe entire supply chainprocessperspective(supplied) should beimplemented. In this project was tried to first is attempted to identify supply chain ParsKhazar and finally a mathematical model that encompasses the important restrictions is the chain members to reduce the overall cost of materials, parts and productsto beoffered

Fast estimation of adsorption isotherm parameters in gradient elution preparative liquid chromatography. I: The single component case

The inverse method is a numeric method for fast estimation of adsorption isotherm parameters directly from overloaded elution profiles. However, it has previously only been used for isocratic experiments. Here we will extend the inverse method so it can be used for gradient elution too. This extended inverse method will make it possible to study the adsorption of substances whose retention factor vary strongly with the mobile-phase composition, like peptides and proteins, where the classic methods will fail. Our extended inverse method was verified using both simulations and real experiments. For simulated overloaded elution profiles we were able to determine almost exact Langmuir adsorption isotherm parameters with the new approach. From real experimental data, bi-Langmuir adsorption parameters were estimated using both the perturbation peak method and the extended inverse method. The shape of the acquired adsorption isotherms did match over the considered concentration range; however, the adsorption isotherm parameters found with the two methods were not the same. This is probably due to the fact that adsorption isotherm estimated with the inverse method is only a good approximation up to the highest eluted concentration in the used chromatograms. But this is not a serious drawback from a process point of view where the main objective is to make accurate predictions of elution profiles. The bi-Langmuir adsorption isotherm obtained with both methods could accurately predict the shape of overloaded elution profiles.

Reproducibility in M&S research: issues, strategies and implications for model development environments

As the use of computer simulation is increasingly becoming central to scientific enterprise, lack of proper documentation, validation and distribution of models and experiments may hamper reproducibility and hence cause a credibility gap. Building on prior research requires ability to reproduce simulation experiments and to further extend models to address increasingly challenging problems. In this article, we delineate three dimensions of reproducible research. For each dimension, issues, strategies and implications for simulation model development are identified. From a technical infrastructure point of view, we introduce the e-Portfolio concept, which is an ensemble of integrated active documents that interweave published manuscript, computer code, data and scientific workflow specification. From the process point of view, strategies and potential mechanisms are delineated to enable authors, publishers, funding agencies, journals and the broader scientific community to cooperate and establish a sustained model base, simulations, experiments and documentation, so that scientists can build on each other's work and achievements.

A computer assistant for monitoring tool performance during the drilling process

Nowadays, making holes using the drilling process plays a fundamental role in the manufacturing industry. However, preventing tool wear and/or breakage is still a major concern. From the production process point of view, several undesirable consequences may arise, such as downtimes, increased production costs, loss of dimensional tolerances and even irreversible workpiece defects. In this sense, the present article presents a computer assistant, which provides information about the current drilling process system. In particular, the computer assistant detects both tool wear and material heterogeneities.

Optimal reaction concept and plant wide optimization of the ethylene oxide process

In this paper, a new method for the identification of the best reaction concept from an overall process point of view is proposed. Using this method the optimal reaction route is determined independent of existing apparatuses and the recycle affecting the reactor is fully considered. The reaction concept and the design parameters of the process are simultaneously optimized. For this purpose, a detailed model of the reaction system including reaction kinetics, thermodynamic relationships, and intrinsic boundaries such as explosion limits as well as a complete model of the downstream process is set up. The potential of different reaction concepts including innovative process intensification alternatives can easily be determined by comparison with an optimized reference case.The example considered in this paper is the oxygen based ethylene oxide process, which is one of the most important chemical bulk processes. Sophisticated cooling in combination with distributed oxygen dosing along the reactor length is identified as best technical reaction concept with a potential of reducing the operating costs of an average sized plant by 1.35Mio$/a compared to an optimized reference case. In addition, the utility consumption is reduced, especially the consumption of electricity is decreased by 46.3%, and the overall CO2 emissions are cut by 8%.In conclusion, the proposed method enables the predictive determination of the best reaction concept from an overall process point of view taking the full interconnections between the reaction concept and the process into account and considering highly innovative process intensification options. Thereby, this method provides a key stone for the development of more economical and more sustainable chemical reactors and processes of the future.

Continuous Improvement Modeling to Support Enterprise Transformation

Enterprise managers have two important objectives: anticipating the enterprise evolution and mastering its transformation. But it is difficult to choose between available models and prove that the selected model can improve the enterprise performance. The aim of this article is to provide a clear view on enterprise modeling and to build a template for developing process models and enhancing their suitability. The enterprise is addressed from a process point of view, because processes impact different enterprise systems and bring considerable gains. An evaluation of process models based on a functional analysis is proposed. This approach acts as a guide for building models. Great importance is given to the impact of models on the enterprise information system and the enterprise knowledge system. As a result, the proposed modeling template keeps the coherence of these systems, allows control of the information flows and knowledge flows that spread through all of the enterprise processes, and permits the cho...

History and future of world's most advanced biorefinery in operation

Running a biomass biorefinery based on lignocellulosic feedstock is challenging both from a processing point of view as well as from a market point of view. Continuous process and product development is needed to meet the dynamics in the markets. Borregaard in Sarpsborg Norway is one of the most advanced biorefineries in operation today and has more than 40 years experience of running such a biorefinery. Based on this experience and presence in many markets, new strategies for converting lignocellulosic biomass to biochemicals and biofuels in a sustainable and profitable way has been implemented. The company is loyal to the biorefinery strategy of making the maximum amount of valuable products out of the biomass. Examples of potential new product lines are microfibrillar cellulose (MFC), water soluble specialty lignins from other sources than wood, lignocellulosic ethanol, proteins and sugar based chemicals. Both experience from the long history of running a biorefinery as well as the main development routes for future new bioproducts is analyzed and discussed.

A STUDY ON THE SUCCESSION MODEL OF FAMILY BUSINESSS

Family business has to face issues such as ownership issue, governance structure issue and succession issue, etc. in enterprise development history. Among them, the succession issue is an important transition point in enterprise’s survival and development. It is thus thought of as one of the most important strategic and decision making issues in the enterprise. This article aims at investigating the succession model of Family business. First, reviews are done on the meaning of Family business. Next, reviews and comments are made on the related models of the succession of Family business. It can be seen from the research that the ways of succession of Family business can be divided into process point of view and psychological point of view. Finally, main conclusions of this article are summarized and perspectives are also made on the future researches.

Remote Sensing Image Processing

Earth observation is the field of science concerned with the problem of monitoring and modeling the processes on the Earth surface and their interaction with the atmosphere. The Earth is continuously monitored with advanced optical and radar sensors. The images are analyzed and processed to deliver useful products to individual users, agencies and public administrations. To deal with these problems, remote sensing image processing is nowadays a mature research area, and the techniques developed in the field allow many real-life applications with great societal value. For instance, urban monitoring, fire detection or flood prediction can have a great impact on economical and environmental issues. To attain such objectives, the remote sensing community has turned into a multidisciplinary field of science that embraces physics, signal theory, computer science, electronics and communications. From a machine learning and signal/image processing point of view, all the applications are tackled under specific formalisms, such as classification and clustering, regression and function approximation, data coding, restoration and enhancement, source unmixing, data fusion or feature selection and extraction. This book covers some of the fields in a comprehensive way.

Dynamic behavior of coke drum process safety valves during blocked outlet condition in the refinery delayed coking unit

The design of Delayed Coking Unit of a refinery is a challenging project. This study highlights some of the design considerations in the delayed coking unit with an emphasis on process point of view and more specifically on the relief conditions of coke drums operating under an upset event which results in overpressure of coke drums.The results provided a practical and useful approach to control release of hot and heavy hydrocarbons to minimize their environmental impact. Blocked outlet conditions of normally open path of coke drum to the main fractionator is a critical issue in a refinery. Pressure safety valves calculations were carried out to address their dynamic behavior. It was assumed that the operating team will recognize the problem with sudden abnormal pressure fluctuations and intervene the upset condition in less than 15 min. A HYSYS simulation helped us to analyze the problem in more details.

A decision support system for animated film selection based on a multi-criteria aggregation of referees’ ordinal preferences

This paper presents a decision support system devoted to the selection of films for the International Animated Film Festival organized at Annecy, France, every year. It deals with the representation and aggregation of referees’ preferences along predefined criteria in addition to their overall selection point of view. The practical requirements associated with this application (often encountered in social or cultural areas as well) are: a common ordinal scale for the criteria scores, a procedure to deal with inconsistencies between criteria and overall scores, explanation tools of each referee’s preference model in order to facilitate the deliberation process and also to argument the selection decision. The processing of referees’ preferences is achieved thanks to a recent method which consists in finding a generalized mean aggregation operator representing the preferences of a referee, in a finite ordinal scale context. The method allows to deal with consistency conditions on referees’ behaviour in order to highlight the criteria or pair of criteria which are the most influential for each of the referees. All the functionalities have been implemented in an interactive decision software that facilitates a shared selection decision. Results issued from the 2007 selection are presented and analysed from the preference representation and processing point of view.

Microalgae as Sources of Carotenoids

Marine microalgae constitute a natural source of a variety of drugs for pharmaceutical, food and cosmetic applications—which encompass carotenoids, among others. A growing body of experimental evidence has confirmed that these compounds can play important roles in prevention (and even treatment) of human diseases and health conditions, e.g., cancer, cardiovascular problems, atherosclerosis, rheumatoid arthritis, muscular dystrophy, cataracts and some neurological disorders. The underlying features that may account for such favorable biological activities are their intrinsic antioxidant, anti-inflammatory and antitumoral features. In this invited review, the most important issues regarding synthesis of carotenoids by microalgae are described and discussed—from both physiological and processing points of view. Current gaps of knowledge, as well as technological opportunities in the near future relating to this growing field of interest, are also put forward in a critical manner.