Operation Of Press Research Articles

Multiple Nerve Damages Because of Occupational Risk Factors

Upper extremity problems due to working are frequently encountered. We presented a case of bilateral multiple nerve damages that were thought to be secondary to working and were evaluated to eliminate the probability of presence of other etiological factors. The patient was a press operator and he was performing elbow flexion and wrist extension against resistance at work. He had numbness in the first and second fingers of his right hand and pain in the forearm. His last EMG revealed right median nerve, left median and ulnar palsy, total denervation in the right radial nerve. The patient underwent an operation in the right cubital region. During the operation, compression was found to be due to soft tissue pressure; the radial nerve was released and the neighboring scar tissue was cleaned. J Med Cases. 2015;6(3):128-130 doi: http://dx.doi.org/10.14740/jmc2068w

Modeling absorption and rheological changes as suspensions are applied to porous substrates

During the application of a suspension to a porous substrate, some components of the suspension can penetrate the substrate and change the properties of the suspension. During offset printing, a pigmented ink contacts porous paper and absorption of the oil from the ink by the paper influences the final product quality and press operations. Although various models have been presented in the literature to describe these processes, a quantitative comparison of models is lacking.Commercial cyan ink was diluted with mineral oil to generate various pigment and resin concentrations in the oil base. A porous ceramic plate with pores of approximately one micron in the top layer was used to simulate the porous layer of a paper-coating layer. The absorption rate of the ink-oil mixture into the plate was characterized gravimetrically. The viscosity change of the mixture after contact with the ceramic plate was characterized by a controlled stress rheometer. Three different models described in the literature were developed further to predict absorption rates and the rate of increasing viscosity. Next, the predictions of these models were compared to the experiments.A filtercake based model predicts the absorption rate at various concentrations of oil and ink. The increase in viscosity due to absorption is predicted qualitatively using various models. A modified filtercake model is proposed that predicts the absorption rates and viscosity increases of these systems within expected accuracy.

The Application of Toggle Mechanical Press in Hot Forming of High Strength Steel

This paper discusses mechanical digital servo press control system and operating characteristics and adaptability to the hot forming requirements of high strength steel using the toggle mechanical presses [1-4]. A servo motor drive control strategy is made to adapt the stamping process. This paper describes results acquired by applying toggle mechanical servo press developed by author to the hot forming of high strength steel [5-7].

Inertial pressing of pipe

Simulation of the inertial pressing of pipe is considered. The influence of the energy parameters of the storage device on the press residue is considered, with different needle designs. Conditions ensuring effective press operation are established.

Study on autobody of lancing process method using forming analysis

Sheet metal forming is one of the most useful and important methods in manufacturing the autobody panels because of the excellent production rate. The objective of sheet metal forming processes is to obtain a desired geometrical shape of products with good quality, low cost and reasonable lead time. This paper examines the validity of the finite element method analysis on the automobile centre pillar (CTR–PLR–L/R) and front pillar (FRT–PLR–L/R) stamping process by using the lancing engineering method. Lancing is a press operation in which a single line cut or slit is made on part way across the strip stock, without removing any metal. As a result, the proper lancing engineering method prevents fracturing by improving the sheet metal flow.

Stress Analysis of the Press Cage in Screw Press by Finite Element Method

Mechanical pressing is one of the most widely used methods of separating oil from oil plants. Screw press is a typical oil extraction equipment adopting this method. In which the pressing chamber is a core component, and the press cage, as a main part of it, whose strength is a precondition to ensure normal operation of the screw press. Comparing with the complexity and drawbacks of traditional analyzing and checking methods, here, computer aided analysis was used to make stress analysis. A simplified 3-D model of the press cage was built, and the finite analysis was conducted by ANSYS software. Then, the continuous deformation and stress distribution of the cage were obtained. The results can provide a good reference to the improvement and optimization of its structure design

Measuring Manufacturing Productivity

Whether manufacturing 2D or 3D printed products, the press itself is one of your largest investments; improving your Return-on- Investment is one of your key goals. For many presses, the ROI is predicated on producing hundreds of thousands or even millions of dollars worth of output. An increase of just a few percent would have a very significant impact on ROI. The industry has heretofore been satisfied with merely tracking job flow. Historically, identifying the obstacles to improving press productivity, utilization, and ROI has relied on anecdotal information; real information – quantitative press productivity data – has not been available.Recognizing the problem, we focused upon the lack of data identifying the bottlenecks. One fundamental breakthrough was realizing that only press operators on the shop floor know much of the needed information. The information must be acquired in a minimally invasive manner, categorized, aggregated, analyzed, and presented as metrics that support and facilitate identification of the real obstacles and bottlenecks.We will describe and demonstrate a new, patent-pending methodology and system that actually measures productivity of any press or other output-producing machine over time. This is not another printing MIS system; rather, it highlights bottlenecks and opportunities for productivity improvement. Implemented with today's state-of-the-art technologies, the system incorporates touchscreen, tablet-based data collection GUI, cloud-based data storage and analysis, and browser-based anytime, anywhere graphical dashboard and reporting.

Printers and Press Operators: The Oregonian Remembered

In May 1919, the Typographical Journal printed reminiscences written by Emily Chenoweth McCown and Wilkie Duniway — both former printers for the Oregonian — after the death of the newspaper's publisher, Henry Pittock. This primary document is a rare first-hand account of skilled trade workers, including engravers, lithographers, and stereotypers, who worked with newspaper printers and pressmen during the 1880s and 1890s. Harry Stein explores the lives of those workers during a time of rapid change in the North American newspaper industry. Linotype machines and improved printing presses introduced mechanization and speed to printing processes and, as a result, altered labor practices and divisions within newspapers. Through Stein's introduction, the historical significance of the letters is revealed.

Dimensional Synthesis for Multi-linkage of High-speed Mechanical Press

In order to improve the performance and solve problems produced under the high speed operation of the high-speed mechanical press, a comprehensive optimal mathematic model of main transmission mechanism of high-speed mechanical press was established. The model takes minimum of crack length and maximum of stamping angle as the evaluation index. In the meantime, the optimal model was established with MATLAB. The optimization result shows that the stamping angle of mechanism is increased by 56.2%, maximum speed of main slider is increased by 21.5% in the return stage, and acceleration of main slider is decreased by 69.5% near the bottom dead position. The displacement curve is more smooth in the near of bottom dead center. The optimized mechanism is beneficial to abundant deformation of material in the process of stamping, and to improve the dynamic precision of the bottom dead center.

First stage of bio-jet fuel production: non-food sunflower oil extraction using cold press method

As a result of concerning petroleum price increasing and environmental impact, more attention is attracted to renewable resources for transportation fuels. Because not conflict with human and animal food resources, non-food vegetable oils are promising sources for developing bio-jet fuels. Extracting vegetable oil from oilseeds is the first critical step in the pathway of bio-jet fuel production. When sunflower seeds are de-hulled, there are always about 5%–15% broken seed kernels (fine meat particles) left over as residual wastes with oil content up to 48%. However, the oil extracted from these sunflower seed residues is non-edible due to its quality not meeting food standards. Genetically modified sunflower grown on margin lands has been identified one of sustainable biofuel sources since it doesn't compete to arable land uses. Sunflower oils extraction from non-food sunflower seeds, sunflower meats, and fine sunflower meats (seed de-hulling residue) was carried out using a cold press method in this study. Characterization of the sunflower oils produced was performed. The effect of cold press rotary frequency on oil recovery and quality was discussed. The results show that higher oil recovery was obtained at lower rotary frequencies. The highest oil recovery for sunflower seeds, sunflower meats, and fine sunflower meats in the tests were 75.67%, 89.74% and 83.19% respectively. The cold press operating conditions had minor influence on the sunflower oil quality. Sunflower meat oils produced at 15 Hz were preliminarily upgraded and distilled. The properties of the upgraded sunflower oils were improved. Though further study is needed for the improvement of processing cost and oil recovery, cold press has shown promising to extract oil from non-food sunflower seeds for future bio-jet fuel production.

<i>In Situ</i> Detection of Forging Defects without Sensors in the Forging Tool

The early detection of defects in forged parts offers economical advantages due to the possibility of sorting them out of the process chain betimes. Hence, no further production costs are occurred by those parts. However, the detection of defects during forging processes is not state of the art. Usually defects of forged parts which are often not obvious and therefore cannot be identified by the press operator are detected by measurements after cooling or later by the customer. In both cases costs occur. Due to the rough conditions in forging shop floors (e. g. high temperatures and forces) the integration of sensors monitoring the forging process is hardly viable. Within the presented research project an in-situ forging process monitoring system is developed which works without sensors in the forging tool and shows results on the process quality directly after forging. A system consisting of two independent concepts (defect-identification and filling-identification) is developed to detect typical forging process failures. On the one hand the defect-identification is able to detect e.g. wrong press energy or insert-position. On the other hand the filling-identification aims to detect, if the cavity is completely filled by the work-piece. Both concepts work in real-time with the help of a computer and a screen visualising the results. One the one hand this paper presents the results of forging trials using the defect-identification and evaluates its capability. On the other hand the concept for the filling identification is presented.

MANUFACTURING DEFECTS OF TABLETS - A REVIEW

Tablet defects can come from any of the unit operation upstream and from the tablet press. The raw materials may be of poor quality or do not meet specification, causing excessive fines that lead to a host of defects. The formulation may be the source of defects if the material do not compress well or the processing step specified within the formulation fail to produce a powder a good flow, compressibility, and ejection properties. The processing and granulation of powder is often the source of defect. Every product behaves differently on a tablet press, even if it’s the same product run on a different day. The variation often stems from changes in the properties of the raw materials—active ingredients and excipients- from batch to batch. Naturally, the goal is to minimize these changes. Tablet press operators, however, don’t have any control over formulation and granulation. Tablet specifications are tight, and the list of possible defects is long: Variable weight, sticking, picking, capping, lamination, variable hardness, among others. This article focuses on these variations. It pinpoints the possible causes of these defects and offers advice on preventing and fixing the source of the problems. Key words: capping, mixing, granules, punches, compression, cracking

Philippe M. F. Peycam. The Birth of Vietnamese Political Journalism: Saigon 1916-1930. New York: Columbia University Press, 2012, xiii+306p.

The Birth of Vietnamese Political Journalism: Saigon 1916-1930 PHILIPPE M. F. PEYCAM New York: Columbia University Press, 2012, xiii+306p.The early 1920s in Saigon saw a florescence of publishing in the lively tradition of Parisian canards of the 1890s. French and Vietnamese language papers sprang up, took forthright positions, debated their peers eagerly, and tested the tolerance of colonial rulers. The French language press was largely free of censorship in Cochinchina, but circulation per day amounted to only several thousand copies total. Vietnamese papers were censored and sometimes shut down, yet daily circulation rose to 22,000 by 1924. This was a time when educated Vietnamese believed that it was feasible to secure more political space from the authorities by means of rational argument and mobilization of opinion.Philippe Peycam brings this story alive for today's readers, introducing us to a range of Vietnamese, French and metis actors, explaining press operations, and outlining the key issues of contention. A newspaper village (lang bao chi) emerged, composed of editors, donor/investors, writers, printers, vendors, and teenagers using the various offices as meeting place and library. A surprising number of French and Vietnamese participants belonged to the Masonic Order. I would have liked to know more about press finances, but recognize that sources are hard to find. A few wealthy landowners were willing to subsidize some papers until the government showed its displeasure at content. Editors pleaded with readers to pay their overdue subscriptions, while acknowledging that the post office sometimes chose to lose copies en route.March-July 1926 saw a dramatic shift to the left in Saigon. The new socialist governor general, Alexandre Varenne, proved a distinct disappointment. The leader of the moderate Constitutionalist Party, Bui Quang Chieu, refused to call for the release from jail of Nguy?n An Ninh, the most charismatic writer and speaker of the time. Crowds cheered when Ninh's comrades insisted that the colonial regime be confronted fearlessly. Following the unprecedented national funeral for Phan Châu Trinh and resulting expulsion of students from school, membership in clandestine patriotic groups proliferated. While these momentous months have been canvassed by earlier scholars, Peycam is the first to examine vigorously the emergence of what he styles opposition journalism. He also offers sensitive portraits of half-a-dozen key journalists beyond Ninh and Chieu.It's a pity that Peycam focuses solely on periodicals, when the 1920s also saw a parallel explosion of books and booklets, often published by the same groups. The monograph format gave authors more room to develop their arguments, even when only 16 or 32 pages in length. Peycam also says nothing about the way in which all these publications expanded the vocabulary and enriched the syntax of the Vietnamese language. However, I was delighted to see all the Vietnamese words in The Birth of Vietnamese Political Journalism carrying full diacritics.Peycam posits the arrival of a new sphere in 1920s Cochinchina, akin to what Jurgen Habermas famously depicted for eighteenth century Europe. Suddenly Vietnam possesses a public political culture, and even mass media politics (p. 34). I question these characterizations on three fronts. First, the audience for Saigon newspapers remained small, even if one assumes that three or four persons perused each copy, and groups sometimes listened to articles being read aloud. Secondly, collaboration between Vietnamese and French or metis activist-journalists fell off during the late 1920s, partly due to Surete divide-and-rule tactics, partly the secrecy demanded by some organizations. Finally, Saigon's effervescent print media failed to trigger similar activity in Annam and Tonkin, at least in the short-term. …

Sheet metal forming limits under stretch-bending with anisotropic hardening

One of the important failure criteria of press operations in industry for forming simulations is the Forming Limit Diagram (FLD). The complex loading effects on FLD, in particular the localized necking phenomenon under stretch-bending condition, have not been fully investigated and well understood. In practical sheet metal applications, the deformation is invariably three dimensional with a combination of stretching and bending. For most sheet materials under these complex loading processes used in industry, strong Bauschinger effect is observed, and the material hardening behavior tends to be anisotropic. This study aims to understand and evaluate such anisotropic hardening effect on the forming limit prediction under stretch-bending condition. The extended through-thickness Marciniak–Kuczynski (M–K) analysis is incorporated with Yoshida–Uemori (YU) two-surface kinematic hardening constitutive model, which has a more accurate description of the reverse loading behavior than that of the conventional isotropic hardening model. The material parameters used in this paper for YU model are calibrated with the experimental data from uniaxial large-strain tension-compression cyclic test. Both the isotropic hardening and YU kinematic hardening models with Hill'48 yield surface are employed in the analysis for the purpose of comparison. The Forming Limit Average Stress Diagram (FLASD) under stretch-bending condition is proposed to extend the understanding of Forming Limit Stress Diagram (FLSD) from in-plane to out-of-plane deformations. The “bending-ratio-dependent” phenomenon in forming limit diagram is predicted and observed in both stress/strain space with the proposed method. It suggests that the individual stress/strain state cannot represent system behavior. Forming limits under stretch-bending is suggested as an occurrence of system instability, not individual material instability. The system behavior of sheet metal deformation is reinforced as critical to the understanding of necking instability in stretch bending processes. The analysis shows that the Bauschinger effect provides positive effect in delaying the necking instability, predicting higher formability for sheet metals under stretch-bending. The insight obtained in this paper provides further understanding of the localized necking phenomenon under stretch-bending condition.

Influence of Allosteric Regulators on Individual Steps in the Reaction Catalyzed by Mycobacterium tuberculosis 2-Hydroxy-3-oxoadipate Synthase

Allosteric regulation often controls key branch points in metabolic processes. Mycobacterium tuberculosis 2-hydroxy-3-oxoadipate synthase (HOAS), a thiamin diphosphate (ThDP)-dependent enzyme, produces 2-hydroxy-3-oxoadipate using 2-ketoglutarate and glyoxylate. The proposed chemical mechanism in analogy with other ThDP-dependent carboligases involves multiple ThDP-bound covalent intermediates. Acetyl coenzyme A is an activator, and GarA, a forkhead association domain-containing protein known to regulate glutamate metabolism, is an allosteric inhibitor of HOAS. Steady state kinetics using assays to study the first half and the full catalytic cycle suggested that the regulators act at different steps in the overall mechanism. To explore the modes of regulation and to test the effects on individual catalytic steps, we performed circular dichroism (CD) studies using a non-decarboxylatable 2-ketoglutarate analog and determined the distribution of ThDP-bound covalent intermediates during the steady state of the HOAS reaction using one-dimensional (1)H gradient carbon heteronuclear single quantum coherence NMR. The results suggest that acetyl coenzyme A acts as a mixed V and K type activator and predominantly affects the predecarboxylation steps. GarA does not inhibit the formation of the predecarboxylation analog and does not affect the accumulation of the postdecarboxylation covalent intermediate derived from 2-ketoglutarate; however, it decreases the abundance of the product ThDP adduct in the HOAS pathway. Thus, the two regulators act on different halves of the catalytic cycle in an unusual regulatory regime.

An apparatus for studying scintillator properties at high isostatic pressures

We describe the design and operation of a unique hydraulic press for the study of scintillator materials under isostatic pressure. This press, capable of developing a pressure of a gigapascal, consists of a large sample chamber pressurized by a two-stage hydraulic amplifier. The optical detection of the scintillation light emitted by the sample is performed, through a large aperture optical port, by a photodetector located outside the pressure vessel. In addition to providing essential pressure-dependent studies on the emission characteristics of radioluminescent materials, this apparatus is being developed to elucidate the mechanisms behind the recently observed dependency of light-yield nonproportionality on electronic band structure. The variation of the light output of a Tl:CsI crystal under 511-keV gamma excitation and hydrostatic pressure is given as an example.

Characterization of the Staphylococcus aureus rRNA Methyltransferase Encoded by orfX, the Gene Containing the Staphylococcal Chromosome Cassette mec (SCCmec) Insertion Site

The gene orfX is conserved among all staphylococci, and its complete sequence is maintained upon insertion of the staphylococcal chromosome cassette mec (SCCmec) genomic island, containing the gene encoding resistance to β-lactam antibiotics (mecA), into its C terminus. The function of OrfX has not been determined. We show that OrfX was constitutively produced during growth, that orfX could be inactivated without altering bacterial growth, and that insertion of SCCmec did not alter gene expression. We solved the crystal structure of OrfX at 1.7 Å and found that it belongs to the S-adenosyl-L-methionine (AdoMet)-dependent α/β-knot superfamily of SPOUT methyltransferases (MTases), with a high structural homology to YbeA, the gene product of the Escherichia coli 70 S ribosomal MTase RlmH. MTase activity was confirmed by demonstrating the OrfX-dependent methylation of the Staphylococcus aureus 70 S ribosome. When OrfX was crystallized in the presence of its AdoMet substrate, we found that each monomer of the homodimeric structure bound AdoMet in its active site. Solution studies using isothermal titration calorimetry confirmed that each monomer bound AdoMet but with different binding affinities (K(d) = 52 ± 0.4 and 606 ± 2 μm). In addition, the structure shows that the AdoMet-binding pocket, formed by a deep trefoil knot, contains a bound phosphate molecule, which is the likely nucleotide methylation site. This study represents the first characterization of a staphylococcal ribosomal MTase and provides the first crystal structure of a member of the α/β-knot superfamily of SPOUT MTases in the RlmH or COG1576 family with bound AdoMet.

MATHEMATICAL MODELS OF PARTICLE SIZE DISTRIBUTION IN SIMULATION ANALYSIS OF HIGH-PRESSURE GRINDING ROLL OPERATIONS

The high-pressure grinding roll (HPGR) technology is currently one of the most efficient methods of hard ore comminution from the scope of the energy consumption. Throughput and energetic models of performance are quite well developed, but technological models predicting the comminution effects still needs an in-depth research. In the paper author presents the method of modeling of HPGR products' particle size distribution by using suitable mathematical models. A basis of the HPGR perfor- mance assessment and HPGR-based crushing circuits design is a product's particle size distribution. In order to precisely determine the particle size distribution of a HPGR product, parameters of product's particle size distributions should be conditional on the main technical parameters of the roller press like operating pressure and the speed of rolls. The most accurate approximation of a distribution of size parti- cle appears to be Weibull's truncated distribution and it is possible to obtain significant relationships between the approximation formula and the value of operating pressure, or feed characteristics. It makes possible a determination of mass recoveries of the product's respective size fractions and the productivity planning. Instead of pressure, the other HPGR operating parameters can be applied, but the pressure value appears to produce the most relevant relationship. A determination of HPGR product's particle size dis- tribution is a basis of the press operation simulation analysis.

Assessing, exploring, and monitoring quality of offset colour prints

Variations in offset print quality relate to numerous parameters of printing press and paper. To maintain a constant high print quality press operators need to assess, explore and monitor quality of prints. Today assessment is mainly done manually. This paper presents a novel system for assessing and predicting values of print quality attributes, where the adopted, random forests (RFs)-based, modeling approach also allows quantifying the influence of different paper and press parameters on print quality. In contrast to other print quality assessment systems the proposed system utilises common, simple print marks known as double grey-bars. Novel virtual sensors assessing print quality attributes using images of double grey-bars are presented. The inferred influence of paper and printing press parameters on quality of colour prints shows clear relation with known print quality conditions. Thorough analysis and categorisation of related work is also given in the paper.

Finite Element Analysis of Press Casing of Screw Press

The pressing chamber is the heart of the screw press, it forms the drainage barrel and has to contain the operating forces of the press. As press casing is an integral part of pressing chamber, the strength of the press casing ensures normal operation of the press. The mechanical models of pressing chamber of the ZX10 type press created in MATLAB 7.0 for linear programming, and the 3D model of the press casing created in UG NX4.0 software were imported into ANSYS 9.0 software and a linear static finite element analysis was performed. The visual deflection patterns the part experiences under "real world" loading conditions were obtained so as to complete the security check of strength.