Reduction Of Process Steps Research Articles

Process Window and Repeatability of Thermomechanical Tangential Ring Rolling

International objectives towards improved resource and energy efficiency require new manufacturing processes, such as the proposed thermomechanical tangential profiled ring rolling process. A rapid cooling-down for microstructural adjustment and a final calibration step via cold forming are combined into one single step. The reduction of process steps and the reduced number of heating cycles present opportunities for improved energy efficiency compared to traditional processes. Based on a series of experiments, this paper aims at showing the potential of this new process in terms of obtainable hardness and microstructure. The influence of the active cooling system and the rolling feed is demonstrated. They are identified as essential with regard to both the geometry and the microstructural properties of the produced part. Finally, the repeatability of the process is analyzed, and potential disturbances are identified and ranked.

Nonoptimal component placement of the human connectome supports variable brain dynamics

Abstract Neural systems are shaped by multiple constraints, balancing region communication with the cost of establishing and maintaining physical connections. It has been suggested that the lengths of neural projections be minimized, reducing their spatial and metabolic impact on the organism. However, long-range connections are prevalent in the connectomes across various species, and thus, rather than rewiring connections to reduce length, an alternative theory proposes that the brain minimizes total wiring length through a suitable positioning of regions, termed component placement optimization. Previous studies in nonhuman primates have refuted this idea by identifying a nonoptimal component placement, where a spatial rearrangement of brain regions in silico leads to a reduced total wiring length. Here, for the first time in humans, we test for component placement optimization. We show a nonoptimal component placement for all subjects in our sample from the Human Connectome Project (N = 280; aged 22–30 years; 138 females), suggesting the presence of constraints—such as the reduction of processing steps between regions—that compete with the elevated spatial and metabolic costs. Additionally, by simulating communication between brain regions, we argue that this suboptimal component placement supports dynamics that benefit cognition.

Real time object customization in CAD system

Object customization in Computer Aided Design (CAD) is a method used to modify the sketch parameters and change the model geometries. This method is one of important features in part modelling which empowered CAD user to simply modify their product. The conventional method of modifying CAD model is usually relied on the manual editing. This paper outlines a development of program than can be integrated in CAD/CAM system for real time object customization. It uses Visual Basic (VB) programming with custom Graphical User Interface (GUI) generated in NX10 (CAD/CAM software) interface. The main contribution of this research is a tool for real time object customization that capable to assist the modification of 3D model. In order to develop the tool, 3D model modification instructions are translated into programming codes by using Journaling tools in NX interface. Editable parameters are identified based on the model shapes. The related codes are reconstructed, modified and linked to the functional GUI. This allows user to simply modify the model shapes in real time with minimum process steps. The performance of the method is evaluated in terms of the reduction of process steps and time in modifying the 3D model in CAD system. All the findings and details of approach are presented.

Polymer-Steel-Sandwich-Structures: Influence of Process Parameters on the Composite Strength

As the demand of the automotive and aerospace industries for lightweight and cost effective materials increases, it is necessary to combine different materials with respect to their lightweight and functional properties. The combination of polymer-steel-sandwich composites - which consist of a polymer core structure (transferring shear loads) and two metal face-layers (absorbing tensile and compression loads occurring at bending) - suite the need of minimizing weight per area under bending loads. The reduction of process steps can be achieved by connecting the face layers and core in-situ via an in-mold assembly process using variothermal processing. The injection mold hereby is heated near the melt temperature of the polymer with a variothermal water processing unit. Via contact heating inserted steel blanks are heated to the same temperature as the mold. This process enables the combination of the metal surface with the polymer core by infiltrating the micro or nano scale structure, which is generated by laser structuring or nano coating. Through the increased mold/blank surface temperature induced via variothermal heating the melt viscosity is lowered. This decreasing viscosity of the polymer melt hereby enables a higher degree of infiltration of the laser structured and nano coated blanks. This improved infiltration behavior is a key factor for the adhesion of the sandwich components and beneficial for the composites strength. Within this work two steel blanks are inserted into the mold to manufacture sandwich structures with steel face layers and a polymer (here: polylactidacid; PLA) core. As these sandwich composites are prone to bending failure, the 4-point-bending test is used to characterize the mechanical properties of this hybrid structure. The two surface treatments will also be compared concerning their mechanical interface properties with a shear edge test. The additional reduction on the polymer melt viscosity by means of gas inducing with chemical blowing agent is investigated on the laser structured surfaces only. To investigate the influence of the polymers melts viscosity on the bonding properties chemical blowing agent is added for some blanks.

Warm and cold blanking of manganese-boron steel 22MnB5 with different tool geometries

Abstract Two main processes for shaping press hardened ultra-high strength steels (UHSS) are laser cutting and cold blanking, which are either cost-intensive and time-consuming or require high blanking force. Therefore, the integration of warm blanking and hot forming in one process represents a possible alternative for shaping UHSS. Due to the integration of various process steps such as forming, blanking and quenching, a reduction of process steps is possible. This leads to a decrease of time and operating costs. Tool load can be reduced as well because of the lower tensile strength of heated steel. However, there are several disadvantages to integrating these process steps. High process temperatures encourage warpage of tool and sheet and therefore an increase in tool and maintenance costs. To investigate the influence of process integration on the blanking and retraction forces and the quality of the cutting surface, several surveys were conducted by one-hole-blanking. One possibility to deal with the disadvantages could be the use of different punch geometries (plane, conical, truncated conical) in combination with different clearances during warm blanking of typical quenched 22MnB5. Characteristic cutting and retraction forces and temperatures as well as parameters of cutting surfaces were measured and analyzed. A variation of the punch geometry and clearance does not give a significant improvement in the forces and quality of the cutting surface. However, for a high part quality with less burr, a plane punch is recommended and a conical or a truncated conical punch may reduce friction induced wear in industrial applications by producing less burnish.

One-step nanoimprinted Bragg grating sensor based on hybrid polymers

Bragg grating sensors are used for real-time analysis of gases or liquids. Complex processing methods are typically required for the sensor fabrication. A reduction of process steps and costs during their fabrication is essential in order to broaden the field of application. Within this work, we demonstrate an innovative process for a one-step fabrication of integrated Bragg grating sensors and their successful application for temperature and refractive index sensing. UV-enhanced substrate conformal imprint lithography (UV-SCIL) is used to replicate surface relief Bragg grating (SBG) sensors on a full wafer scale. Multiple chips of a planar waveguide system including couplers and junctions were etched into a silicon wafer. Nanostructured SBGs were locally added on the waveguides by focused ion beam processing. The sensor structures were replicated by UV-SCIL into a commercially available hybrid polymer (OrmoComp®). Reflection measurements with different Bragg gratings were performed and compared to simulations. The results reveal narrow-band Bragg reflections, coinciding with the simulations. Further, the temperature dependence of the SBGs was investigated. The imprinted grating structures featured a very high temperature sensitivity of −202 pm/°C. The sensor response to a varying refractive index of the surrounding medium was determined for index matching liquids and aqueous solutions.

A Review on Biodiesel Production through Heterogeneous Catalysis Route

AbstractDepletion of oil reserves, increasing prices of petroleum products, and environmental concerns related to air pollution are the main driving forces for utilizing renewable energy resources to replace fossil fuels. Vegetable oils can be used to produce biodiesel. Biodiesel is obtained by transesterification of vegetable oil with alcohol using homogeneous or heterogeneous catalysts. In the industry, biodiesel is produced by heterogeneous catalysts due to high activity and selectivity, better reusability, reduction in processing steps, and wastes. The catalytic activity of catalysts depends on the strength and type of intrinsic basic or/and acid properties. Biodiesel production using heterogenous catalysts depends on the various reaction parameters such as reaction time, temperature, molar ratio of alcohol to oil, catalyst amount, and stirring speed. In this paper, the catalytic transesterification of various feedstocks such as edible oil, non‐edible oil, and waste using heterogeneous catalysts has been reviewed and optimization parameters for maximum biodiesel production have been summarized.

Binder-Free Hybrid Titanium-Niobium Oxide/Carbon Nanofiber Mats for Lithium-Ion Battery Electrodes.

Free-standing, binder-free, titanium-niobium oxide/carbon hybrid nanofibers are prepared for Li-ion battery applications. A one-pot synthesis offers a significant reduction of processing steps and avoids the use of environmentally unfriendly binder materials, making the approach highly sustainable. Tetragonal Nb2 O5 /C and monoclinic Ti2 Nb10 O29 /C hybrid nanofibers synthesized at 1000 °C displayed the highest electrochemical performance, with capacity values of 243 and 267 mAh g-1 , respectively, normalized to the electrode mass. At 5 A g-1 , the Nb2 O5 /C and Ti2 Nb10 O29 /C hybrid fibers maintained 78 % and 53 % of the initial capacity, respectively. The higher rate performance and stability of tetragonal Nb2 O5 compared to that of monoclinic Ti2 Nb10 O29 is related to the low energy barriers for Li+ transport in its crystal structure, with no phase transformation. The improved rate performance resulted from the excellent charge propagation in the continuous nanofiber network.

Influence of the Manufacturing Process (Comparison MuCell and Direct-LFT) of Foamed and Fiber Reinforced Polymer Sandwich Structures on the Fiber Length

The automotive and aerospace industries ask for lightweight and cost effective materials, material combinations and structures for their products. To achieve these goals certain composite material groups have to be optimized with respect to their lightweight potential and production methods.Thermoplastic sandwich composites - which consist of a core structure (transferring the load) and two face-layers (absorbing tensile and compression loads occurring at bending) - suite the need of minimizing weight per area under bending loads. Reduction of process steps can be achieved by connecting the face layers and core in-situ via in mold assembly process using foam injection molding (FIM). FIM uses a single material system and – as within this work – physical blowing agents (PBA) for foaming. To increase the strength and stiffness of FIM parts, (long glass) fibers are in cooperated to create long fiber reinforced thermoplastic (LFT) materials.A commercially available version of the LFT-FIM process is the MuCell® process (Trexel, Inc.). LFT granulate (~ 11 mm length) is fed into the injection molding machine, melted and combined with nitrogen as PBA. To skip the needed compounding process step of the rod granules Fraunhofer ICT developed a Direct LFT-FIM process where polymer and continuous fibers are fed into a twin-screw extruder, melted and mixed with nitrogen. This single phase solution then is transferred to an injection unit.Within this work, these two foam injection molding processes will be compared concerning their achievable fiber length. For that purpose, (foamed) long fiber reinforced polypropylene (PP) blanks were manufactured using identical raw materials such as polymer, additives and glass fibers. The semi-finished product, starting material for the MuCell® process, were manufactured by EASICOMP GmbH using the same raw materials as with the D-LFT process. The different blanks – foamed and fiber reinforced PP (30 wt% and 40 wt %) – were manufactured using one injection unit for the MuCell® process and one for the D-LFT-FIM process. To compare the fiber length the same mold optimized to reduce fiber breakage was used in both processes.

Aluminothermic production of titanium alloys (Part 2): Impact of activated rutile on process sustainability

The aluminothermic process provides a cost-reduced production method for titanium and titanium alloys by reduction of TiO2 with subsequent refining by electroslag remelting The aluminothermy involves high heating rates, high temperatures and short reactions times combined with a self-propagating behaviour of the reaction. By co-reduction of TiO2 and oxides of alloying elements such as vanadium pentoxide, direct synthesis of a titanium alloy is possible. The use of rutile ore concentrates causes a further reduction of process steps. In order to charge rutile ore complex thermodynamic calculations are required taking enthalpy input of various bycomponents into account. The aluminothermic reduction is conventionally enhanced by a highly heatproviding reaction based on the reduction of KClO4. In order to minimize the use of chlorine-based products extensive studies are made to investigate the feasibility of using mechanically activated rutile as input material for the aluminothermic process. Due to the mechanical activation the intrinsic enthalpy of the reaction is increased thus facilitates a process with reduced amount of KClO4. A major challenge represents the determination of a compromise between low activation duration and reduced KClO4 amount. In order to define the process window parameters like intrinsic chemical energy (enthalpy of the reaction mixture), equilibrium temperature and physical properties (particle size and mixing degree) were optimized. After adjusting the process parameters it is possible to save up to 42 % KClO4 for the ATR reaction with 2h activated input material. This reduction of KClO4 material affects a decrease of the produced gaseous compounds and the subsequent off-gas cleaning system.

Trends in the Steel Industry: Innovative Solutions to Drive Sustainability

Megatrends will shape the future. Climate change, urbanization, demographic change and globalization challenge all industries. The key to success will be the speed how the steel industry adapts to this fast changing environment. In order to sustainably maintain a competitive position, steel producers must focus on innovative technological solutions which provide advantages regarding costs, quality, production and maintenance. Siemens VAI Metals Technologies therefore focuses on sustainability in their research and development activities which provide benefits to steel producers now and in future. The biggest growth rates can be expected in India in the years to come. However, tightened competition must be expected, especially from China and other high developed steel producing countries. In recent years Siemens VAI Metals Technologies has increased its numbers of innovations with focus on flexibility regarding raw material quality, energy saving and recovery solutions, operational enhancements, reduction of process steps by compact plant designs and linking of processes, productivity and quality gains and maintenance improvements. An outlook into the future is provided in brief showing some future scenarios derived from an internal study called Pictures of the Future, made by Siemens VAI Metals Technologies recently.

Low-Cost Fabrication Strategies of Microfluidic Device on Glass Substrate

This paper presents a simple but reliable fabrication process for microfluidic devices on glass substrate using wet etching technology. Instead of using expensive Pyrex glasses as substrates and depositing expensive metal or polysilicon/amorphous silicon as etch masks in conventional method, glass slide is used as substrate and a single-layer negative photoresist RFJ-220 is used as the etching mask. The etch rates, generation of defects, undercut ratio and surface roughness are studied. In order to achieve high etching depth and smooth surface, buffered oxide etching with hydrochloric acid as additive is proposed. By proper cleaning and long-time hard baking, the undercut ratio can approach to 1. An 110μm depth microchannel with smooth surface is achieved. This fabrication process leads to a considerable reduction of process steps, fabrication time and material consumption. With this technique, we successfully fabricated a microfluidic device, which is used in the capture of hepatoma cells HepG2.

Production of Ti-6Al-4V Strip by Direct Rolling of Blended Elemental Powder

A significant research effort within the CSIRO Light Metal Flagship is aimed at developing new processes for the manufacture of (semi-finished) titanium products based on a powder metallurgy approach. The main driver for considering alternative processing and consolidation techniques to conventional ingot metallurgy is improved techno-economics associated with a reduction in processing steps and increased productivity via rapid consolidation of parts. In this respect, CSIRO has developed a process to manufacture sheet products utilising direct powder rolling; the process consists of cold rolling the powder feedstock to a green strip, which is then rapidly heated and hot rolled to consolidate the material completely. The work reported here was an investigation into the feasibility of fabricating Ti-6Al-4V strip by a blended elemental powder metallurgy route. The development of microstructures occurring during the processing and heat treatment steps has been studied. The generic roles of some process, material and heat treatment variables on the tensile properties and homogeneity of the final material have been assessed and are discussed in this paper.

Diffusion-Driven Device for a High-Resolution Dose−Response Profiling of Combination Chemotherapy

Combination therapies have proven vital in the fight against HIV and cancer. However, the identification and optimization of such combination therapies is largely experience driven and an activity of clinicians rather than of systematic screening efforts. Here we present a diffusion device, compatible with the format of a 12-well microtiter plate, to create and test all possible mixtures of two substances with only two pipetting steps. Applications to the testing of different drug combinations and the parallel screening of different leukemia cell lines as well as primary patient cells are presented. The diffusion device yields qualitatively and quantitatively comparable results to an MTT viability assay conducted in a standard 96-well format albeit with a tremendous reduction of processing steps. In addition, a fluorescence-based annexin V binding assay of cell death was implemented. Next to the reduction of processing steps, the diffusion device constitutes a considerable assay miniaturization that overcomes the problems typically associated with miniaturization as a consequence of small sample volumes. Given its ease of handling, the device will greatly advance the development and optimization of combination drugs and the identification of optimum drug combinations in personalized medicine.

Development of a Robust, Versatile, and Scalable Inoculum Train for the Production of a DNA Vaccine

For many microbial fermentation processes, the inoculum train can have a substantial impact on process performance in terms of productivity, profitability, and process control. In general, it is understood that a well-characterized and flexible inoculum train is essential for future scale-up and implementation of the process in a pilot plant or manufacturing setting. A fermentation process utilizing E. coli DH5 for the production of plasmid DNA carrying the HIV gag gene for use as a vaccine is currently under development in our laboratory. As part of the development effort, we evaluated inoculum train schemes that incorporate one, two, or three stages. In addition, we investigated the effect of inoculum viable-cell concentrations, either thawed or actively growing, over a wide range (from 2.5 x 10(4) to 1.0 x 10(8) viable cells/mL or approximately 0.001% to 4% of final working volume). The various inoculum trains were evaluated in terms of final plasmid yield, process time, reproducibility, robustness, and feasibility at large scale. The results of these studies show that final plasmid yield remained in the desired range, despite the number of stages or inoculation viable-cell concentrations comprising the inoculum train. On the basis of these observations and because it established a large database, the first part of these investigations supports an exceptional flexibility in the design of scalable inoculum trains for this DNA vaccine process. This work also highlighted that a slightly higher level of process reproducibility, as measured by the time for the culture to reach mid-exponential growth, was observed when using actively growing versus frozen cells. It also demonstrated the existence of a viable-cell concentration threshold for the one-stage process, since we observed that inoculation of the production stage with very low amounts of viable cells from a frozen source could lead to increased process sensitivity to external factors such as variation in the quality of the raw materials used in the medium formulation. However, our analysis indicates that, despite this slight disadvantage, a one-stage inoculum train was a viable option in many situations, especially if the inoculation viable-cell concentration was kept above 4.8 x 10(6) viable cells/mL. Because it leads to a reduction in process steps and eliminates some capital investments (i.e., inoculum fermenter), when feasible a one-stage process configuration will positively impact process economics.

AC-3-irradiation test of sphere-pac and pellet (U,Pu)C fuel in the US Fast Flux Test Facility

The objective of the AC-3 bundle experiment in the Fast Flux Test Facility (FFTF) was to evaluate a fuel fabrication method by ‘direct conversion’ of nitrate solutions into spherical uranium–plutonium carbide particles and to compare the irradiation performance of ‘sphere-pac’ fuel pins prepared at Paul Scherrer Institute (PSI) with standard pellet fuel pins fabricated at Los Alamos National Laboratory (LANL). The irradiation and post test examination results show that mixed carbide pellet fuel produced by powder methods and sphere-pac particle fuel developed by internal gelation techniques are both valuable advanced fuel candidates for liquid metal reactors. The PSI fabrication process with direct conversion of actinide nitrate solutions into various sizes of fuel spheres by internal gelation and direct filling of spheres into cladding tubes is seen as more easily transferable to remote operation, showing a significant reduction of process steps. The process is also adaptable for the fabrication of carbonitrides and nitrides (still based on a uranium matrix), as well as for actinides diluted in a (uranium-free) yttrium stabilized zirconium oxide matrix. The AC-3 fuel bundle was irradiated in the Fast Flux Test Facility (FFTF) during the years 1986–1988 for 630 full power days to a peak burn up of ∼8 at.% fissile material. All of the pins, irradiated at linear powers of up to 84 kW/m, with cladding outer temperatures of 465 °C appeared to be in good condition when removed from the assembly. The rebirth of interest for fast reactor systems motivated the earlier teams to report about the excellent, still perfectly relevant results reached; this paper focusing on the sphere-pac fuel behaviour.

The Effects of Hydrogen Annealing on Gate Oxide Integrity of U-Shaped Trench MOSFET with 400 Å Gate Oxide

The effects of hydrogen annealing on the thick gate oxide integrity of the U-shaped trench metal-oxide-semiconductor-field effect transistor (UMOSFET) were investigated. annealing was performed after trench etch and before gate oxidation. It was observed that the gate oxide integrity (GOI) of the gate oxide grown after annealing can be comparable to the standard approach (soft etch and sacrificial oxidation) when the trench width is kept at . When the trench width was reduced to the GOI of annealing samples was degraded slightly due to faceting at the transition region between trench sidewall and bottom. It was proven that using high-temperature gate oxidation, the UMOSFET with trench width and annealing has very high-quality gate oxide. The reduction of process steps and time and the potential for narrower trench make annealing an attractive process in trench MOSFET processing.

Production of AA6082 Feedstock for Forming in the Semi-Solid State

Thixoforming offers the possibility of forming complex aluminum parts with a superior quality and a reduction of processing steps. The production of a fine, equiaxed, globular microstructure is essential for thixoforming. Strain Induced Melt Activation (SIMA) and the Cooling Slope (CS) casting processes were employed to produce AA6082 thixotropic feedstock in the present work.. SIMA process produces such a microstructure through recrystallization of heavily deformed billets and a subsequent heat treatment in the mushy zone. Molten metal with a suitable superheat is cast over a water-cooled, inclined metal plate into a permanent mould to produce the thixotropic billet in the CS casting route. The effect of cold work and heating temperature and time were investigated for the SIMA process where as the effect of CS length, casting temperature on the final microstructures were investigated for a fixed set of heating conditions in the CS casting route.

In situ fabrication of SU-8 movable parts by using PAG-diluted SU-8 as the sacrificial layer

In this paper we proposed a novel technology to make SU-8 movable parts in situ by using PAG-diluted SU-8 or SU-8R, a SU-8 solution with no photoacid generator (PAG) content, as the sacrificial layer. Since they are not or less sensitive to UV light the unexposed bottom layer in UV lithography will be dissolved to release the movable components during the final develop in PGMEA (Propylene Glycol Monomethyl Ether Acetate). The use of PAG-diluted SU-8 or SU-8R as a sacrificial layer offers several advantages including significant reduction in processing steps. It becomes the simplest technique currently available for in situ fabrication of SU-8 movable parts. In this paper the lithographic sensitivities of SU-8 as a function of the PAG concentration, detailed fabrication process and examples of fabricated SU-8 movable parts will be presented.

Use of a photoresist sacrificial layer with SU-8 electroplating mould in MEMS fabrication

In this paper, new processes have been developed to fabricate micromechanical components and systems that utilize two different photoresists (Shipley S1813 and Hoechst AZ P4620) as sacrificial layers in conjunction with SU-8 photoresist used as an electroplating mould. The use of photoresists as sacrificial layers offers several advantages including reduction in processing steps and hence processing cost. However, the normal sacrificial layer photoresist processing cycle fails when used in conjunction with SU-8 photoresist. The latter is often used as an electroplating mould, especially for high-aspect ratio or tall microstructures in MEMS fabrication. In this paper, problems arising in the use of a photoresist sacrificial layer are discussed and new sacrificial layer processes are developed. New curing temperatures for photoresist sacrificial layers are determined, which prevent damage that otherwise occurs from the use of SU-8 as an electroplating mould. New hard baking temperatures determined are 175 °C and 200 °C for S1813 and AZ P4620 photoresist processes, respectively. A comb drive structure is utilized to demonstrate these new fabrication processes.