Operational Charts Research Articles

Red lead: understanding red lead in lead−acid batteries

The use of red lead in battery plates is not very well known to a large segment of the lead–acid battery industry. Historically, it was used in pasted and tubular positive plates in order to improve their formation time and enhance deep-cycle performance. Although the use of red lead has diminished over the last few decades, many companies are again considering the use of red lead in their plates. This article aims to give manufacturers a solid knowledge of the properties of red lead, including production and handling methods. Further, it presents an understanding of the influence in battery production, battery performance, and the cost-saving potential of red lead usage. The first part of the article is intended to explain the chemical and physical properties and fields of usage of red lead. The most widely used red lead product specifications for the battery industry are presented and explained. In the second part, the typical equipment for the production of red lead is reviewed. Raw material requirements, material handling equipment, a red lead furnace and milling are presented and discussed. The reader is taken through the production of a typical batch of red lead. Operating charts, process control data and system photos will help to understand the production process. The final part outlines an overall view of process requirements and identifies stages in lead–acid battery production that will be influenced by the use of red lead.

Clinical importance of supratubal recess in cholesteatoma surgery.

To determine the importance of supratubal recess in cholesteatoma surgery by presenting the clinical presentation, imaging findings, and surgical treatment methods of 66 patients with cholesteatoma. We propose that the management of supratubal recess allows the opportunity for total removal of the cholesteatoma with the prevention of recurrence. Retrospective review of surgical cases. Tertiary referral center. Diagnostic and therapeutic procedures were performed. We present a series of patients with involvement of supratubal recess by reviewing the operative charts of 347 patients surgically treated for aural cholesteatoma between 1990 and 1999. We detected the involvement of supratubal recess in 19% (n = 66) of our operations for aural cholesteatoma removal. The intent of this study is to improve the chance for a successful outcome by decreasing the rate of recurrence. The surgical approach to supratubal recess in cholesteatoma operations is emphasized with our series.

U-shaped production lines: A review of theory and practice

Most writers describe the U-shaped production line as the special type of cellular manufacturing used in just-in-time (JIT) production systems. JIT is defined to be an umbrella term for a number of techniques whose purpose is to improve product quality and cost by eliminating all waste in the production system. The U-line arranges machines around a U-shaped line in the order in which production operations are performed. Operators work inside the U-line. One operator supervises both the entrance and the exit of the line. Machine-work is separated from operator-work so that machines work independently as much as possible. Standard operation charts specify exactly how all work is done. U-lines may be simple or complex. U-lines are rebalanced periodically when production requirements change. The U-line satisfies the flow manufacturing principle. This requires operators to be multi-skilled to operate several different machines or processes. It also requires operators to work standing up and walking. When setup times are negligible, U-lines are operated as mixed-model lines where each station is able to produce any product in any cycle. When setup times are larger, multiple U-lines are formed and dedicated to different products. 114 US and Japanese U-lines are examined in this study. The average U-line has 10.2 machines and 3.4 operators. About one-quarter of all U-lines are manned by one operator and so run in chase mode. The reported benefits are impressive. Productivity improved by an average of 76%. WIP dropped by 86%. Leadtime shrunk by 75%. Defective rates dropped by 83%.

Operating charts for continuous sedimentation I: Control of steady states

The industrial process of continuous sedimentation of solid particles in a liquid takes place in a clarifier-thickener unit, which is a large tank with a feed inlet somewhere in the middle and outlets at the top and bottom. For half a century the constitutive assumption by Kynch has provided a platform from which steady-state mass-balance considerations have been used to obtain rules and graphical tools for prediction of steady-state situations, design and control. This is often referred to as the `solids-flux theory' containing such key words as the `operating line', `state point' and `limiting flux'. The basic assumptions of the solids-flux theory yield a nonlinear partial differential equation that models the entire process. Since unique physically relevant solutions can now be obtained, the knowledge of these is used to establish and extend the solids-flux theory. Detailed information on all steady-state solutions and the control of these by adjusting a volume flow is presented by means of operating charts. Most of these are concentration-flux diagrams with information on, for example, how to perform a control action to fulfil a certain control objective formulated in terms of the output variables in steady state.

Laboratory evaluation and system sizing charts for a ‘second generation’ direct PV-powered, low cost submersible solar pump

A ‘new generation’ solar operated low-power and low capital cost submersible diaphragm pump designed for medium head applications is evaluated in this paper. The pump is designed and made by SHURflo Ltd. and is the 9325 type. The primary use of this pump is in providing water for remote homes and clinics, for human consumption and for agricultural use. In all tests, the pump was connected to a dedicated controller that allows either 12 V or 24 V operation. The experiments were undertaken by using the pumping test rig at CRES, and the evaluation methodology was ‘simulated field conditions’. The instantaneous water flow versus head characteristics were functions of the global irradiance on the array plane. The PV array power varied between 55 Wp and 220 Wp and both voltage modes were examined. The hydraulic efficiency was also calculated with respect to equivalent head. The daily operation charts were obtained by using the instantaneous pump performance in combination with typical daily irradiation profiles and the pump starting and stopping characteristics. These charts are useful for system sizing, taking into account the solar resource at the site of application, the required daily water delivery at a particular head and the available PV array. The results show that with this ‘new generation’ of direct solar-powered pumping systems, the PV array has been minimised, and so has been the capital investment cost, the need for battery storage has been eliminated and adequate water is delivered at an affordable price.

The use of KidSat images in the further pursuit of the frankincense roads to Ubar

A small team of middle and high school students used space shuttle images from the KidSat camera to conduct remote archaeology in an attempt to find indications of ancient "lost" cities, structures, or caravan routes in the Arabian desert. Working with scientists from NASA's Jet Propulsion Laboratory in Pasadena, CA, archaeologists from Southwest Missouri State University in Springfield, MO, and geographers from Humboldt State University in Arcata, CA, students utilized a variety of data and resources, including images taken from the space shuttle, Landsat images, Tactical Pilotage Charts (TPCs), Operational Navigation Charts (ONCs), archaeological maps, primary historical accounts, image processing tools, and secondary text and internet sources to hypothesize the many possible trade routes. In this research, the student team encountered and applied unique features of the KidSat images to this investigation.

Effect of natural organic matter loading on the atrazine adsorption capacity of an aging powdered activated carbon slurry

The effect of natural organic matter loading and calcium carbonate precipitate towards atrazine adsorption capacity of an aging powdered activated carbon slurry was investigated in an hybrid membrane process consisting of an immersed microfiltration membrane system in a completely stirred tank reactor containing powdered activated carbon. The reactor was fed with clarified Seine river water containing natural organic matter (NOM). Samples of the slurry were taken from the reactor and dried at low temperature to avoid the adsorbed NOM degradation. Thermal and CaCO 3 analyses were carried out to characterize each sample. The adsorption capacity of each sample was measured by the classical method of isotherms, a modelling method was applied to predict the adsorption capacity in natural water. Kinetic experiments were carried out and the results were also modelized to determine kinetic parameters ( k f and D s). The isotherms showed a significant decrease of the capacity during the 62 d of aging (from 3.4 to 0.4 mg g −1 for an equilibrium concentration of 0.1 μg L −1 in distilled-deionized water). A linear relationship was found between the Freundlich constant K and the age ( r 2>0.9). The kinetic experiments showed also the decrease of the D s value (from 1.16×10 −15 to 8.3×10 −17 m 2 s −1) while k f remained constant and appeared as a non-limiting parameter. Operating charts based on these results were drawn as tools for operators giving operating conditions (age of PAC slurry and fresh PAC dosage rate) to remove a given concentration of atrazine.

Clinical Significance of Fever After Percutaneous Nephrolithotomy

Objectives. In the immediate postoperative period after percutaneous stone removal, body temperature elevations are common. Pyrexia after a percutaneous nephrolithotomy (PCNL) generates concern because of the possibility of urinary extravasation and bacteremia. We reviewed our experience with PCNL to determine the clinical significance of a postoperative fever before discharge from the hospital. Methods. Between July 1994 and December 1996, 63 patients underwent 69 PCNLs. Each had documented negative urine cultures preoperatively and received prophylactic antibiotics at the time of surgery. For each case, clinical and operative charts were reviewed to determine stone composition, fever during hospital stay, postoperative bacteriologic cultures, postoperative white blood cell count (WBC), and clinical course. Results. Complete data were available for 66 procedures. Eight patients (12%) had at least one body temperature reading between 38.0 and 38.5°C. Eleven patients (16.7%) had at least one temperature greater than 38.5°C. Each patient with a temperature greater than 38.5°C was hemodynamically stable with negative blood and urine cultures. No patient with a fever between 38.0 and 38.5°C was cultured. Stone analysis did not demonstrate any association between postoperative fever and stone composition (including 22 struvite stones). Postoperative WBC also did not predict pyrexia. Fever alone did not prolong hospital stay. Conclusions. In patients with negative urine cultures who are prophylaxed with immediate preoperative antibiotics and maintained on postoperative antibiotics, pyrexia after PCNL does not require an immediate bacteriologic evaluation in those who are hemodynamically stable.

Supracricoid partial laryngectomy with cricohyoidoepiglottopexy for “early” glottic carcinoma classified as T1-T2N0 invading the anterior commissure

Purpose: “Early” glottic squamous cell carcinoma classified as T1-T2N0 with anterior commissure invasion is conventionnaly managed with vertical partial laryngectomy (VPL) or radiation therapy (FIT). At our institution, in the early 1980s, vertical partial laryngectomy was progressively replaced by supracricoid partial laryngectomy with cricohyoidoepiglottopexy (SCPL-CHEP). The medical files and operative charts of 62 patients with “early” glottic carcinoma classified as T1-T2N0 invading the anterior commissure, consecutively managed with cricohyoidoepiglottopexy, were retrospectively reviewed to ascertain whether any conclusions could be drawn regarding this treatment modality. Materials and Methods: Survival, local control, nodal recurrence, distant metastasis, and metachronous second primary tumor estimate was analyzed using the Kaplan-Meier life table method. Results: The 3- and 5-year actuarial survival estimate was 93.3% and 86.5%, respectively. The 3- and 5-year actuarial local control estimate was 98.2%. The only patient with local recurrence was successfully salvaged with FIT resulting in an overall 100% local control rate and laryngeal preservation rate. The 3- and 5-year actuarial nodal recurrence estimate was 1.8%. The 3- and 5-year actuarial distant metastasis estimate was 0% and 2%, respectively. Aspiration related completion total laryngectomy and permanent tracheostomy never occurred. Conclusion: The present retrospective study suggests that cricohyoidoepiglottopexy for glottic carcinoma classified as T1-T2 invading the anterior commissure resulted in higher local control rates and overall laryngeal preservation rate when compared with historical series using either VPL or RT. Further series are warranted to confirm our results.

A transformation procedure for digitising Defense Mapping Agency air navigation charts

The mathematical transformation for converting coordinates digitised from the Defense Mapping Agency 1:1 million Operational Navigation Chart, the 1:2 million Jet Navigation Chart and the 1:500,000 Tactical Pilotage Chart map sheets into latitudes and longitudes is described. A least squares adjustment is employed in order to improve the accuracy, and to provide a check on the quality of the digitisation.

Direct needle insufflation for pneumoretroperitoneum: anatomic confirmation and clinical experience

Objectives The feasibility and safety of direct needle insufflation to create pneumoretroperitoneum was assessed by an imaging study and clinical experience. Methods A total of 10 patients without previous retroperitoneal surgery or diseases received computed tomography scans of the retroperitoneum 2 cm above the iliac crest. Distances between quadratus lumborum and colon (Q-C distance) were measured in the supine and lateral positions. Changes of Q-C distance were calculated when the patient was changed from the supine to the lateral position. Operative charts on 38 retroperitoneoscopic procedures were collected prospectively to assess complications related to direct needle insufflation, which was performed by inserting a 14 G Veress needle blindly along the posterior axillary line 2 cm above the iliac crest. Results Q-C distance increased from 8.7 to 27.3 mm (left side) and 4.6 to 18.1 mm (right side) when the patient was changed from the supine to the lateral position, both P values <0.05. An average distance of 23 mm between colon and quadratus lumborum was found when patients were lying laterally. The misplacement of a Veress needle was encountered in 1 patient, in which a prefascia insufflation resulted in conversion of the endoscopic procedure. Needle puncture caused no visceral or great vessel injury. Conclusions Significant anterior movement of the colon was found when patients were changed from the supine to the lateral position. It provided a window for inserting the Veress needle blindly into the retroperitoneum. The high success rate (97%) and low complication rate of direct needle insufflation were found in actual clinical applications. We considered needle insufflation a safe and effective method of establishing a pneumoretroperitoneum for any retroperitoneoscopic procedure.

Design and control of flotation thickeners

Process variables influencing clarification and thickening by dissolved air flotation are summarized. Operational adjustments to full-scale thickeners are usually limited to the speed and periodicity of the float scrapers which, in turn, directly influence the effective drainage time of liquid from the floating sludge mass. Expressions are derived which relate float solids concentration and total float depth to the effective drainage time. Design and operation charts are derived from the equations. Results obtained from the City of Philadelphia Northeast WWTP are used to demonstrate the validity of the derived expressions. The enhanced thickening characteristics obtained when water treatment plant sludge was discharged to the WWTP is demonstrated. Polymer addition had only a slight beneficial effect. Use of the charts for operational control is demonstrated by means of an example.

Design and control of flotation thickeners

Process variables influencing clarification and thickening by dissolved air flotation are summarized. Operational adjustments to full-scale thickeners are usually limited to the speed and periodicity of the float scrapers which, in turn, directly influence the effective drainage time of liquid from the floating sludge mass. Expressions are derived which relate float solids concentration and total float depth to the effective drainage time. Design and operation charts are derived from the equations. Results obtained from the City of Philadelphia Northeast WWTP are used to demonstrate the validity of the derived expressions. The enhanced thickening characteristics obtained when water treatment plant sludge was discharged to the WWTP is demonstrated. Polymer addition had only a slight beneficial effect. Use of the charts for operational control is demonstrated by means of an example.

Calculation of optimal parameters for drill-and-blast operation chart in mining with direct slot stage cutting

Calculation of optimal parameters for drill-and-blast operation chart in mining with direct slot stage cutting

Anaesthesia for Charcot-Marie-Tooth disease: a review of 86 cases.

Operative charts were reviewed in 86 patients with Charcot-Marie-Tooth disease, a condition characterized by chronic muscular denervation. A total of 161 surgical procedures was performed. Major complications were few, and only one operative death occurred, unrelated to anaesthesia. Succinylcholine and malignant hyperthermia triggering agents were used in 41 (48%) and 77 (90%) patients, respectively, without untoward effects. Contrary to previous reports, this survey supports the safe use of succinylcholine and MH triggering agents in this disease.

Meteorological Support ofVoyagerWorld Flight, 14–23 December 1986

Meteorological support for the record-breaking, nine-day, nonstop, non-refueled flight around the world by Dick Rutan and Jeana Yeager in the Voyager aircraft 14–23 December 1986 is described. The strict meteorological criteria demanded by the flight restrictions of the unique Voyager aircraft and the facilities and meteorological tools used are discussed. A detailed description of the weather encountered during the world flight and the meteorological reasoning involved during selection of critical flight tracks are given. Satellite pictures and operational weather charts are used in an attempt to retain the authenticity of the meteorological background of this historic flight.

Activated Sludge Process Control by Behaviour of Secondary Settling Tanks

The mathematical models of activated sludge kinetics and solids flux have been investigated; the constants have been derived experimentally. By developing the equations of the two models, an operational chart for activated sludge process control has been plotted.

Operation Charts for a Successive Fed-batch Fermentation of Alcohol

Operation Charts for a Successive Fed-batch Fermentation of Alcohol

Pocket Computer Solution to Composite Materials Formulas

This paper contains the descriptions and instructions of the use of Radio Shack TRS-80 Pocket Computer for the key calculations of stiffness and strength of sym metric composite laminates. Specific programs are constructed, using BASIC language, to give instant computa tions on: (1) In-Plane Stiffness of Symmetric Laminates (2) Flexural Rigidity of Symmetric Sandwich Plates (3) In-Plane Strength of Symmetric Laminates (4) Flexural Strength of Symmetric Sandwich Plates The formulas and equation numbers used in the programming are the same as that found in Tsai and Hahn's "Introduction to Composite Materials" (Technomic, 1980). Listings of the programs are included along with flow diagrams, operation charts and memory contents. It would be a simple matter to run the program on a variety of minicomputer systems by altering the syntax as appropriate.

Design and operational charts for complete mixing activated sludge systems

This paper provides charts enabling the derivation of design and operational procedures for an activated sludge waste water treatment system including the final settler. These charts are based on a mathematical model including Monod relationships describing the microbial growth and the substrate removal in the aerator, while sedimentation in the final settler is assumed to follow the limiting flux theory. Charts represent the minimum required settler area, insuring that given effluent standards will be met, as a function of either the hydraulic retention time or the recycle rate. Most design and operational characteristics of the activated sludge system can be read directly on the charts, while a simple equation is provided for the sludge wasting rate. Operational procedures under constant or variable inflow conditions are first derived from the charts. It is concluded that operational policies including a constant recycle sludge concentration are especially attractive in response to various types of influent variations. Such policies allow one to maintain either the effluent substrate concentration or the recycle flow rate at the same level in most situations. Furthermore, the required settler area remains reasonably small. Large aerators provide considerable operational flexibility and appear to be required when hydraulic overloads are expected. The charts allow one to design the activated sludge system in such a way that expected overload conditions can be overcome. Least-cost design is briefly studied through simplified cost functions. This allows derivation of the best compromise between sufficient operational flexibility and least-cost design, leading to the “optimal overdesign” of the system. Parameter variability has a significant influence on the charts. Hence, correct determination of the model parameters is required before calibrating and using the charts.