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This article introduces four rubber-pad formation techniques for the pressing and drawing of components from thin sheet metals. The Guerin process is the simplest technique of rubber formation, which enables the production of shallow sheet metal parts with complex contours and bends. Free formation is another technique used to draw near-hemispherical shells using a rubber medium. Different bending processes can also be conducted using a rubber pad as a flexible die. Multipoint formation is applied to form complex three-dimensional sheet metal parts with discrete dies and rubber cushions. The fundamentals of these techniques as well as the influence of process parameters on the results are investigated in this paper

A strategy based on machine learning is discussed to close the gap between the detailed description of combustion chemistry and the numerical simulation of combustion systems. Indeed, the partial differential equations describing chemical kinetics are stiff and involve many degrees of freedom, making their solving in three-dimensional unsteady simulations very challenging. It is discussed in this work how a reduction of the computing cost by an order of magnitude can be achieved using a set of neural networks trained for solving chemistry. The thermochemical database used for training is composed of time evolutions of stochastic particles carrying chemical species mass fractions and temperature according to a turbulent micro-mixing problem coupled with complex chemistry. The novelty of the work lies in the decomposition of the thermochemical hyperspace into clusters to facilitate the training of neural networks. This decomposition is performed with the Kmeans algorithm, a local principal component analysis is then applied to every cluster. This new methodology for combustion chemistry reduction is tested under conditions representative of a non-premixed syngas oxy-flame.

Background: The aim of this study was to evaluate the role of nasogastric tube after laparoscopic repair of small peforation of duodenal ulcers in low risk patients. Methods: A retrospective study on 69 consecutive perforated duodenal ulcer patients with size of perforation of less than 5 mm, ASA score of less than 4, Boey score of less than 2, treated with laparoscopic repair at Hue University of Medicine and Pharmacy Hospital from January 2012 to June 2018. Patients were divided into two groups: group 1 with postoperative nasogastric tube and group 2 without postoperative nasogastric tube because patients were uncooperative and removed the nasogastric tube themselves. Results: The mean age was 47.8 ± 14.7 years. Male/female ratio was 22. The mean of duration from symptom onset until surgery was 7.5 ± 5.5 hours. 60 patients (87.0%) had a Boey score of 0 and nine patients (13.0%) had a Boey score of 1. The mean of size of perforation was 3.5 ± 1.0 mm. All of perforations were on the anterior duodenal wall. The patients in the group 2 had a significantly shorter interval between surgery and passage of first flatus than in group 1 (1.8 ± 0.5 days vs 2.6 ± 0.7 days (p = 0.042)), had a significantly shorter postoperative hospital stay than in group 1 (4.5 ± 0.6 days vs 5.8 ± 0.8 days (p = 0.026)). There was no significant difference between group 1 and group 2 in the duration of analgesic use (2.3 ± 0.5 days vs 2.8 ± 0.8 days, p = 0.097). There was no morbidity or mortality in two groups. Conclusions: The patients without postoperative nasogastric tube had a significantly shorter interval between surgery and passage of first flatus and postoperative hospital stay. The use of postoperative nasogastric tube in small perforations of duodenal ulcers in low risk patients seems to be unnecessary. Key words: Perforated duodenal ulcer, laparoscopic repair, laparoscopic surgery, nasogastric tube

Thermal radiation is the dominant mode of heat transfer in many combustion systems, and in typical flameless furnaces, it can represent up to 80% of the total heat transfer. Accurate modeling of radiative heat transfer is, thus, crucial in the design of these large-scale combustion systems. Thermal radiation impacts the thermochemistry, thereby the energy efficiency and the temperature sensitive species prediction, such as NOx and soot. The requirement to accurately describe the spectral dependence of gaseous radiative properties of combustion products interacts with the modeling of finite rate chemistry effects and conjugates heat transfer and turbulence. Additionally, because of the multiple injection of fuels and/or oxidizers of various compositions, case-specific radiative properties' expressions are required. Along these lines, a comprehensive modeling to couple radiation and combustion in reacting flows is attempted and applied to the simulation of flameless combustion. Radiation is modeled using the spectral line-based weighted-sum-of-gray-gases approach to calculate gaseous radiative properties of combustion products using the correlation of the line-by-line spectra of H2O and CO2. The emissivity weights and absorption coefficients were optimized for a range of optical thicknesses and temperatures encountered in the considered furnace. Efforts were also made on the development of a reliable and detailed experimental dataset for validation. Measurements are performed in a low calorific value syngas furnace operating under flameless combustion. This test rig features a thermal charge which can extract about 60% of combustion heat release via 80% of radiative heat transfer, making it of special interest for modeling validation. The comparison between the simulation and the experiment demonstrated a fair prediction of heat transfer, energy balance, temperature, and chemical species fields.

Background: Single-port laparoscopic surgery (SPLS) is increasingly used in surgery and in the treatment of perforated duodenal ulcer. The aim of this study was to evaluate technical factors for perforated duodenal ulcer repair by SPLS. Methods: A prospective study on 42 consecutive patients diagnosed with perforated duodenal ulcer and treated with SPLS at Hue university of medicine and pharmacy hospital and Hue central hospital from January 2012 to February 2015. Results: The mean age was 48.1 ± 14.2 (17 - 79) years. 40 patients were treated with suture of the perforation by pure SPLS. There was one case (2.4%) in which one additional trocar was required. Conversion to open surgery was necessary in one patient (2.4%) in which the perforation was situated on the posterior duodenal wall. Two patients (4.8%) with history of abdominal surgery were successfully treated by pure SPLS. The size of perforation was correlated with suturing time (correlation coefficient r = 0.459) and operative time (correlation coefficient r = 0.528). Considering suture type, X stitches were used in 95.5% cases, simple stitches were used in one case (2.4%) while Graham patch repair technique was utilized in one case (2.4%) with large perforation. Most cases (95.1%) required only simple suture without omental patch. Peritoneal drainage was spared in most cases (90.2%). Conclusions: SPLS is a safe method for the treatment of perforated duodenal ulcer. Posterior duodenal location is the main cause of conversion to open surgery. Factor related to operative time is perforation size. Key words: perforated duodenal ulcer, single port laparoscopic repair, single port laparoscopy

Background: Single-port laparoscopic surgery (SPLS) is increasingly used in surgery and in the treatment of perforated duodenal ulcer. The aim of this study was to evaluate mid-term outcome of perforated duodenal ulcer repair using SPLS. Methods: A prospective study on 72 consecutive patients diagnosed with perforated duodenal ulcer and treated with SPLS at Hue University Hospital and Hue Central Hospital from January 2012 to Mars 2016. Results: The mean age was 48.8 ± 14.0 (17 - 79) years. Male/female ratio was 17.0. Four patients (5.6%) with history of abdominal surgery were successfully treated by pure SPLS. Patients were classified as ASA 1, ASA 2 and ASA 3 in 86.1%, 12.5%, and 1.4% of cases, respectively. Using Boey scoring system, there were 86.1% and 12.5% of cases classified as Boey 0 and Boey 1 while there were no Boey 2 and 3 cases. The average size of perforation was 4.1 ± 2.6 (1.5-22) mm. The perforation was situated on the anterior duodenal wall in 98.6% of cases and on the posterior duodenal wall in 1.4% of cases. There was one case (1.4%) in which one additional trocar was required. Conversion to open surgery was necessary in one patient (1.4%) in which the perforation was situated on the posterior duodenal wall. Average length of hospital stay was 5.7 ± 1.2 (4-12) days. Post-operative complications rate was 2.8%. There was no leakage from the repair site, no port-site hernia and no post-operative mortality. At 2-month follow-up visit, patients were classified as Visick 1 in 95.1% of cases and Visick 2 in 4.9% of cases and the duodenal ulcer was completely healed on gastroduodenoscopy in 86.7% of cases. At 12-month follow-up, patients were classified as Visick 1 in 93.5% of cases and Visick 2 in 4.3% of cases. There was one case (2.2%)diagnosed with recurrent duodenal ulcer perforation at 5 months after the repair of the first perforation. On gastroduodenoscopy, recurrent duodenal ulcer was seen in 8.9% of cases. Conclusions: SPLS is a safe method for the treatment of perforated duodenal ulcer. Conversion rate was 1.4%. Recurrent duodenal ulcer rate was 8,9% and recurrent duodenal ulcer perforation rate was 2.2% after 12-month follow-up. Key words: perforated duodenal ulcer, single port laparoscopic repair, single port laparoscopy

Background Single-port laparoscopic surgery (SPLS) was increasingly used on several surgical diseases. The aim of this study is evaluation of the results of the suture of the perforation by SPLS for the perforated duodenal ulcer treatement. Methods From January 2012 to July 2014, 35 patients with perforated duodenal ulcers underwent simple suture of the perforations by SPLS at Hue University Hospital and Hue Central Hospital. Results The mean age was 45.9 ± 14.4 years. The sex ratio (male/female) was 16.5 and the mean of BMI was 19.2 ± 2.3. There was one patient (2.9%) with previous history of laparoscopic repair of perforated duodenal ulcer. The duration of the symptoms was 9.9 ± 12.3 hours. 97.1% of patients had the perforations of the anterior wall of the duodenum. The mean size of the perforation was 4.7 ± 3.4 mm (2 – 22mm). 2.9% of patients had the perforations of the posterior wall of the duodenum. The rate of the conversion to the open surgery was 2.9%. The mean operative time was 75.8 ± 33.7min, and the mean hospital stay was 5.8 ± 1.4 days. The mean of the analgesic requirement time was 2.9 ± 0.8 days. The wound length was 1.9 ± 0.1 cm. There was 5.9% of the patients had wound infection. There was no operation-related mortality. Conclusions Simple suture of the perforation by single-port laparoscopic surgery is a feasible and safe procedure, and it may be a scarless surgical technique for perforated duodenal ulcers treatement. Key words: single-port laparoscopic surgery, perforated duodenal ulcer

Objectives: Developing software for practice and assessement of the anatomy of the thorax and abdomen. Main contents and Method: Development of the software will include the following steps: Dissection of a male cadaver at the anatomy department of the Hue College of Medicine and Pharmacy; Taking pictures of each stage of dissection; Collection of images from other sources; Use of Macromedia Authorware software for development of software for practicing and assessing the anatomy of the thorax and abdomen. Results: Our goal is to have software of 414 MB size, and when installed will have a directory entry of size 477MB containing 3 programs files. Overall, will contain: 497 pages, with each page containing an image and description of anatomical structures of the thoracic wall, lungs, heart, mediastinum, abdominal wall, inguinal canal, peritonial cavity, stomach, spleen, liver, intestines, pancreas, kidney and adrenal gland, and also male and female pelvis. 13 3D videos for the organs and structures of the thoracical and abdominal cavities. 100 single choice quesitons for the organs and structures of the thoracic and abdominal cavities. The software will be very easy to use. It will be useable for any area of medical specialty.

The role of principal additives is investigated in an attempt to obtain high-threshold-field ZnO-based varistors in the traditional way. In the order of effect level, these are Sb2O3, Co3O4, Cr2O3 and MnO2. In the range of 0.5-5 mol%, the increase of additive content decreases the average ZnO grain size. As a result, the number of grains per unit thickness increases, which gives rise to the threshold field. The value of barrier voltage vb calculated from experimental data is about 1.4-2 V. The potential barrier height determined from the temperature dependence of the current-voltage characteristics is 0.3-0.5 eV. The abnormally large vb of a sample doped with 8 mol% Sb2O3 is quantitatively interpreted by the influence of the spinel phase through the energy-band-bending effect caused by the Bi2O3-rich phase and the hypothesis of a 'preferential path' of the current.

'Nam Roi' pummelo is a famous fruit tree in the Mekong Delta of Viet Nam. Therefore, in recent years, growers extended the cultured area because it guarantees a high income. As a consequence there is a high demand for planting material, and we studied the possibilities of vegetative propagation by cuttings during the period from March 1999 to February 2000. The results of our study showed that a rice husk substrate was better than sand, and that naphthalene acetic acid (NAA) 1000 ppm stimulated rooting (84% rooted). The type of cutting was also a factor affecting the success rate; we studied three types of cuttings.