Abstract: We report on transient laser action during the photo- polymerization process in organic thin films of acrylate monomers doped with a laser dye. The emission spectrum was monitored over a period of time in the direction orthogonal to the incident laser beam which is kept at a constant intensity during the experiments. The emission spectra display the signature of laser action after a certain amount of polymerization. We have also recorded the intensity of fluorescence as well as of the amplified stimulated emission (ASE) using a photodiode. Our results confirmed that all the emission is guided by an increase of the refractive index resulting from the photopolymerizationprocess. The spatial fluctuations in the density of the material are thought to act as micro-cavities leading to a random laser effect.
the apparatus emitting polymerizing light has been developed concurrently with the modernisation and the improvement of composite materials. Polymerization lamps differ from each other in many respects depending on the course of photopolymerizationprocess. this process is influenced by many factors such as: the monomer’s structure and functionality, composition and properties of resins, the temperature of the reaction, the presence of the oxygen, viscosity etc. the intensity of the light of photopolymerization lamps gradually decreases so it should be checked with the special metering equipment: radiometers, testers fixed in polymerization lamps, thermopiles. devices evaluating the polymerization process can assess, for example, remains of unreacted form of the monomer and real-time physicochemical changes: loss of function groups responsible for polymerization, photocrosslinking, polimerization shrinkage, index of light refraction (Dent. Med. Probl. 2012, 49, 4, 487–494).
Background. The basic knowledge of photometry and colorimetry possessed by dentists can increase their profes- sional work standards and facilitate co-operation on different communicative levels. The thermal effect of such reaction is the summary derivative of the kinetics of the reaction itself as well as the energy delivered by the light source used in the process. Due to the potential risk of thermal damage of tooth pulp, attempts of examining and explaining how temperature rise impacts tooth tissues need to be taken.
SLA method using the UV light is one of the various methods used to create the 3D structures. This method has been the oldest and still widely used. This process has obtained the patent in 1986 by Charles Hull . Also, DLP is similar to the SLA method. The main dif- ference of the DLP is to use a visible light source, such as a liquid crystal display panel and an arc lamp. SLA and DLP are based on the vat photopolymerization principle of photosensitive monomer resins when ex- posed to UV light or another similar power source. Photopolymerization is driven by a chemical reaction that produces free radicals when exposed to certain wavelengths of light. Photons from the light source dis- sociate the photoinitiator to a high energy radical state. The radical induces the polymerization of the macromer or monomer solution. However, the problem with this photopolymerizationprocess is that the created free rad- icals can have damage to the cell membrane, protein, and nucleic acids. Therefore, it is important to find a cytocompatible photo-initiator for the SLA 3D printing method. A typical schematic of vat photopolymerization method is shown in Fig. 2(a). To obtain the 3D scaffold for tissue engineering application, many researchers re- ported the SLA product with various biomaterials.
The goal of this work was to create a multi-physics finite element model that can accurately compute the electromagnetic, chemical and mechanical interactions that occur during the process of photopolymerization. This thesis has presented the successful development of the model that can be adapted to various physical situations to compute the reactions of different photosensitive resins undergoing the photopolymerizationprocess. We have detailed the theoretical background in developing this model includ- ing the effects contributed from electromagnetic interactions, the polymer concentration and its dependence on the intensity from the incoming light source, and the mechanical response of the polymerizing resin throughout the curing process. A simplified polymer concentration rate equation was proposed for easier computation that provided a refrac- tive index saturation effect that closely correlates with the saturation seen in experimental studies. The final refractive index change of 2% for the given input values were based off of experimental and material data from .
Photonics AG, iBeam) is used to photopolymerize the UV curing resin in the sample cell. A linearly polarized beam after a polarizing beam splitter (PBS) cube is directed to a spiral phase plate (SPP, RCP Photonics, VPP-1c), where the Gaussian beam is converted to a Laguerre-Gaussian beam carrying topological charge in the range of | | ≤ S 4. The vortex beam is focused by a high numerical aperture (NA) microscope objective (MO, Olympus, × 60, NA = 1.1 water immersion) to achieve an annular beam pro ﬁ le with a diameter of 1 − 2 μ m depending on S (see Figure 2 inset panels and Supporting Information, Figure S3). The beam focus is carefully located at the glass/resin boundary in order to initiate the photopolymerizationprocess on the glass surface of the sample cell. The laser power and the exposure time are ﬁ xed at 3 mW and 0.9 s, respectively, unless stated otherwise. Time-Lapse Imaging. Temporal evolution of the photo- polymerization is recorded by two complementary metal- oxide-semiconductor based cameras, for the side- and axial- views (CMOS1; CMOS2, Basler AG, acA1300 − 200um, 203 fps) at a frame rate of 100 fps. Time-lapse images recorded by the side-view camera visualize the growth of photopolymerized ﬁ bers and reveal their helical structure along the beam axis. The axial-view camera, on the other hand, can visualize the rotation of the ﬁ ber and its handedness.
There is an urgent demand worldwide for the development of highly selective adsorbents and sensors of heavy metal ions and other organic pollutants. Within these environmental and public health frameworks, we are combining the salient features of clays and chelatant polymers to design selective metal ion adsorbents. Towards this end, the ion imprinting approach has been used to develop a novel nanohybrid material for the selective separation of Cu 2+ ions in aqueous solution. The Cu 2+ -imprinted polymer/ montmorillonite nanocomposite (IIP/Mt) and non- imprinted polymer/montmorillonite nanocomposite (NIP/Mt) were prepared by radical photopolymerizationprocess in the visible light. Ion imprinting was indeed important as the recognition of copper ions by IIP/Mt was significantly superior to that of NIP/Mt that is the nanocomposite synthesized in the same way but in the absence of Cu 2+ ions. The adsorption process as batch study was investigated under the experimental condition affecting same parameters such as contact time, concentration of ions metals and pH. The adsorption capacity of Cu 2+ ions is maximized at pH 5. Removal of Cu 2+ ion achieved equilibrium within 15 minutes; the results obtained were found to be fitted by the pseudo-second order kinetics model. The equilibrium process was well described by the Langmuir isothermal model and the maximum adsorption capacity was found to be 23.6 mg/g.
octagon and from the octagon to the round in each of these processes. In this paper, using same method 2) as for the square process, the relationship between the bite ratio and the coeﬃcient of the width spread in each pass was investigated using a numerical simulation, and an equation to predict the shape in each pass was developed in the octagon process. The inﬂuence of forging conditions (the octagon shape, the feed, the rotation angle) on dimensional accuracy was investigated in the tap process. The process design method of achieving both good dimensional accuracy and productivity in the ﬁnish forging process was developed.
Saaty (1993:17) mentions that the preparation of a problem hierarchy is a step to defining complicated and complex problems so that are clearer and more detailed. The problem hierarchy is structured to help the decision making process that takes into account all the decision elements involved in the system. The decision hierarchy is prepared based on the views of those who have expertise and knowledge in the field concerned, the decision to be taken is made as a goal which is elaborated into more detailed elements to reach a stage that is most operational or measurable. The terms used in AHP for hierarchical level are: 1) Hierarchy level 0 is the goal, 2) Hierarchy level 1 is criteria, 3) Hierarchy level 2 is sub criteria, and 4) Hierarchy level 3 is alternative. The hierarchical structure in this study is contained in figure 2 below.
The experiments were conducted using Taguchi L9 design approach. The significance and contribution of each process parameter on the performance characteristics were found out using ANOVA method. The objective of this research was to determine the process parameters required to achieve minimum circularity and taper. Therefore, the quality characteristics of „smaller is better‟ for all performance characteristics were engaged in this study. The ANOVA results were developed by using the statistical software MINITAB. Each process parameter was designed to have three levels which are shown in Table 1 and the experimental results are presented in Table 2.
Currently, there are many tools helping the organizations define a software process. For example, a paper that presented a process definition to support a software development process via Software Process Lines . Organizations that need to improve software process can apply similar defined processes in their organization. Another paper proposes a tool to define electronic process guideline in a small software company . It defined basic process for the company by preparing technical conference and gathering the opinion of specialists. The research mentioned above emphasizes some tools to support some process definition only. It does not include the functions for auditing if the defined process has been implemented. An audit process is an important part of the “PPQA” area or the process and product quality assurance based on CMMI framework. The goal is to audit processes and
Laser forming is non convectional process of shaping or bending of metallic components, as a mean of rapid prototyping and of adjusting and aligning. There is no mechanical contact between tool and work material. These provide more advantage of process flexibility. Laser forming process works on the principle of “Thermal stresses are induced into the surface of work piece using high power laser beam. The internal stress induced plastic strain that bends the material that results in the elastic-plastic buckling.”In laser forming process heat is applied on the surface of work piece with a high power laser beam. So due to this applied heat the temperature gradient is generated across the thickness of work piece and produces thermal stress across the thickness of the work piece. So the internal stress induced due to external heat applied leads to plastic strain in the work piece that bend the material or results in elastic-plastic buckling which bends the sheet. the sheet metal is placed on work table, one end is fixed on a table using clamp while the other end is free. The heating on the material surface on one side by a moving laser beam which moves from one point to another in a straight line in defined path. The laser parameter such that laser power, feed rate and beam diameter should be adjusted such that surface melting of material is avoided. The sheet metal expands in heated zone and the surrounding material at lower temperature produces thermal stress in the work piece. The thermal stresses induce in the work piece due to temperature difference leads to a bending of the sheet metal.
(Tansel and Arkan, 1998) As the depth of cut is sometimes less than the grain size in the work piece material. The assumption of homogeneity in work piece material properties is no longer valid. Because Micro-grain-structure size is often of the same order of magnitude as the cutter radius of curvature, the grain structures will affect the overall cutting properties. This is a distinct difference between micro- and macro mechanical machining. The assumption in macro- mechanical machining is always that the materials are isotropic and homogenous. The changing crystallography during the cutting process also causes variation in the micro- cutting force and generates vibration. This vibration is difficult to eliminate by changing the machine tool design or process conditions, because it originates from the work piece. Therefore, an averaged constant cutting coefficient cannot e used for micro-machining applications due to tool geometry, small grain size, and non-uniformity of the work piece material. Examined vibration caused by no homogeneous materials (i.e. aluminum single crystal with in precision machining operations. They found that changing crystallography and grain orientation affects shear angle and strength. (Takeuchi and Sakaida, 2003) Analyzed the cutting force in turning-related to work piece material and hardness. Using different aluminum and silicon alloys, they observed different microstructures significantly influence the magnitude of the cutting force, both in their static and dynamic components. When the cutting tool engages from one metallurgical phase to another, the cutting conditions change, causing machining errors, vibration, or accelerated tool wear.
As both referees of this text claimed, and as proponents of anonymous and blind peer reviewing process claim, open-process peer reviewing might be a significant deterrent to many, if not to the vast majority of referees. The logic is the following: younger academics, or those with a lower career profile, or simply those whose work might be affected by any aspect of the reaction of the author who is being reviewed – none of these academics are likely to be willing to review a paper of a big academic star, if their names are revealed. According to this logic, anonymity protects the referee and gives her the freedom to respond without any possible retaliation by the author. Following the advice of referees and editors to put myself in the shoes of reviewers, rethinking the issues once more, I cannot identify with this logic. I tried. It does not work for me. If anything comes to my mind in such role playing, it is the desire to always have my name associated with the work I do. Anything less feels wrong to me, and rather unethical (Godlee, 2002). A critique behind the veil of anonymity, the key purported positive feature of the current system, seems also entirely at odds with how the new writing is produced. In writing, everything has to be referenced, the more, the better. Ideas are critiqued, improved or abolished, and it works not only because we see rational arguments in relation to each other, but because by knowing the name, the history, the previous work and intellectual, sometimes even business and political, associations of the author, we can put those ideas, both original and their critiques, in context.
Helpful Hints Check current year tax update manual for changes to the process Instructions for Form 1042-S and Publication 1187 (Specifications for Filing Form 1042S, Foreign Person’s U.S. Source Income Subject to Withholding, Electronically). Beginning Tax Year 2008 the IRS will no longer accept tape cartridge submissions.
requirements? Which processes are following a given regulation? Where do vi- olations occur? Which processes do we have under control? And so on. While IT has been supporting (in more or less automated fashions) the execution of business processes for long time now, in the past the adoption of ad-hoc and monolithic software solutions did not provide the necessary insight into how processes were executed and into their runtime state, preventing the adoption of IT also for compliance assessment. The advent of workflow management systems and, especially today, of web service-based business interactions and the service-oriented architecture (SOA) have changed this shortcoming, turning business processes into well-structured, modular, and distributed software arti- facts that provide insight into their internals, e.g., in terms of execution events for tasks, service calls, exchanged SOAP messages, control flow decisions, or data flows. All these pieces of information can be used for online monitoring or enforcement of compliant process behaviors or they can be logged for later assessment. Unfortunately, however, the resulting amount of data may be huge (in large companies, hundreds of events may be generated per minute!), and especially in terms of reporting and analysis it is not trivial to understand which data to focus on and how to get useful information out of them. Do- ing so is challenging and requires answering questions like how to collect and store evidence for compliance assessment in service-based business processes, how to report on the compliance state, and how to support the analysis of non- compliant situations. But more than these, the challenges this paper aims to solve are how to collect evidence in a way that is as less intrusive as possible, how to devise solutions that are as useful as possible, yet at the same time as generic as possible and independent of the particular IT system to be analyzed, and, finally, how to provide compliance experts with information that is as use- ful and expressive as possible. In light of these challenges, this paper provides the following contributions:
A process-centric clinical trial system with BPM provides the optimum infrastructure to manage and control critical business processes, and integrate with enterprise systems. Applications and business logic can be built out as needed by the organization. TranSenda has the only BPM platform focused solely on the life sciences industry. Over the last two years, we’ve collaborated with many of the industry’s largest players to create application libraries as well as process and interface templates that bridge the gap between market-savvy traditional clinical support applications and powerful, but market-agnostic pure play BPM vendors. The result is an industry-focused solution with flexibility and expandability that
In the other view, a larger number of studies tend to investigate only specific parts of a crowdsourcing process. The ad hoc nature of these studies has been recently highlighted in the literature (Geiger and Schader 2014; Man-Ching et al. 2011; Zhao and Zhu 2014). The issue is not about their usefulness due to lack of repeatability, but instead there is no collective cohesiveness. As a result, there is little scaffolding of the studies’ outcomes towards a structured, holistic framework. That is, this group of studies have suggested scattered sets of practices, which challenges organisations when trying to establish their crowdsourcing processes. As a result, the domain is still lacking “a comprehensive guideline through which practitioners can initiate and manage their crowdsourcing projects” (Amrollahi 2015, p. 2). In our research, we attempt to reconcile the two views by providing a more integrated picture of the crowdsourcing process. More precisely, we describe this integration as Business Process Crowdsourcing (BPC). The term BPC was coined by La Vecchia and Cisternino (2010), and further discussed by Thuan at al. (2014) as a way to establish organisational business processes based on crowdsourcing. Etymologically, BPC combines the phrase business process with the word crowdsourcing. This paper elevates the business process construct to be equally important to the crowdsourcing construct. According to Aalst and Hee (2004), a business process is defined as a collection of individual activities and a workflow coordinating them. It aims to achieve a particular goal with both effectiveness and efficiency. A business process is purely conceptual, yet it serves as a template for creating multiple, real life instances of the same process, which organisations may create repeatedly and concurrently. Given that, we define BPC as a set of activities completed by crowdsourcing entities, in conjunction with a coordination of these activities, that collectively form the entire business process.