Study of Gasoline Pre-chamber combustion at Lean Operation

Regulations and other demands to enhance automobile fuel economy are growing increasingly strict to reduce CO2 as a measure to address the issues of global warming. The goal of this study was to enhance the fuel economy in high-load operation of a gasoline engine for hybrid vehicles, which is a useful means of addressing this issue. Technology for achieving lean combustion in high-load operation was studied to realize higher brake thermal efficiency by increasing the ratio of specific heat compared to theoretical air-fuel ratio (stoichiometric) EGR combustion. Issues for applying lean combustion to high-load operation include 1) the increased oxygen molarity results in increased knocking tendency compared to stoichiometric EGR combustion, and 2) increased leanness results in greater combustion variation due to the ignition delay period and the delayed second half of the combustion period. In order to solve these issues at lean operation, several combustion methods are examined on test bench. In this test study, Pre-chamber stratified combustion has an advantage of lean operation performance. Ignitability and high-speed combustion period of pre-chamber combustion was secured by setting the ignition areas inside the pre-chamber to the rich side relative to the total air-fuel ratio (A/F). NOx emissions are an issue for stratified combustion, but NOx emissions can be reduced by setting the pre-chamber A/F to approximately 23 and by making the pre-chamber volume sufficiently small compared to the main combustion chamber volume. Tests were performed using a single-cylinder engine to determine the pre-chamber volume and the diameter and number of jet nozzles. The pre-chamber volume and the diameter and number of jet nozzles were set under the restriction of dP/dθ, which is the index of combustion noise, as the target value or less. This specification realized minimum advance for the best torque (MBT) operation with an A/F of 35 at 2000 rpm, IMEP 810 kPa. The heat release characteristics of prechamber combustion shows that unlike the typical combustion pattern using strong flow, the heat release characteristics have two peaks. The first peak is the flame state wherein the jet flame has spread throughout the entire combustion chamber. This shows that the amount of heat released inside the pre-chamber enabled the flame jets from the jet nozzles to spread within the main combustion chamber. The second peak is the state wherein the unburned gas around the spread jet flames is all burning instantaneously. This combustion state results in rapid and stable combustion during the second half of combustion. This combustion characteristic realized MBT lean combustion in high-load operation. The balance between the compression ratio and the surface volume ratio (S/V) was reviewed to counter the drop in efficiency due to the increased S/V as a result of adding a pre-chamber, and this enabled MBT operation at 2000 rpm, IMEP 870 kPa, A/F 35 with an IMEP variation rate of 1.2 %, a main combustion period of 18 deg, and NOx of 30 ppm. Together with the effects of heat insulation coating inside the pre-chamber, this enhanced the brake thermal efficiency by +2 point compared to stoichiometric EGR combustion

Reliability consideration of a mobile communication system with network congestion

AbstractHigh quality traffic for networks is urgently needed for mobile communication systems. Mobile stations frequently become unavailable due to communication errors generated by network congestion. Traffic congestion in a network system may occur intermittently and continue for a length of time, sometimes causing communication errors. If congestions happens during communication, communication errors occur and the communication is rejected. This paper considers the problem of reliability in mobile communication systems during congestion by using a recovery scheme. We formulate a stochastic model of a mobile communication system which consists of mobile stations, several base stations and a switching center. When communication errors occur, the system makes a rollback recovery and returns to the recent checkpoint. We derive the mean time to take checkpoint and the expected number of rollback recoveries, handoff, and successful transmissions until communication errors occur. Further, we calculate the expected costs and discuss ways to minimize the costs by analyzing the optimal checkpoint intervals

Effect pof Root Temperature on the Budbreak and the Shoot Growth of Potted Vines of Muscat of Alexandria Heated from December and from February

ブドウ樹の発育と地温条件との関係を明らかにするために,接ぎ木2年生の鉢植えMuscat of Alexandria(H.F.台)について,1974年12月9日と1976年2月2日から室温を17℃以上に保ったガラス室内で,地温を6段階（12月処理：10,15,20,25,30,35℃,2月処理:15,18,20,25,30,33℃)に調節し,発芽ならびに新梢生長に及ぼす地温の影響を調査した. 1)ブリーディンブは地温15℃以上でみられ,12月処理,2月処理ともに処理開始後まもなく始まった. その期間は12月処理で長く,とくに20,25および30℃の各区では2週間もしくはそれ以上続いた. なお,2月処理ではいずれの区も4ないし7日間であった. 2)発芽所要日数は,12月処理では各区とも35-45日の範囲内で,地温が高い区ほど短かかったが,2月処理ではそのような傾向は認められず,いずれの区も17-20日の範囲内であった. 発芽率は,12月処理では母枝上の基部の芽もよく発芽した25,30℃の両区で高く,10℃区と15℃区では低かったが,2月処理では処理区間の差は少なかった. また,2月処理では発芽の開始から終了までの期間(発芽ぞろい)はいずれの区も短かかったが,12月処理では発芽率の低い10,15℃の両区で長かった. 3)発芽後の新梢生長は,12月処理,2月処理ともに,20,25,30℃の各区ですぐれ,10℃以下と33℃以上の区で劣った. また,新楕生長がすぐれた区では花房数も多い傾向であった. 4)以上の結果から,Muscat of Alexandriaの発芽に及ぼす地温の影響は処理時期によって著しく異なるが,新梢生長については,どの時期においてもその効果が大きいと思われた

Gas-Phase Epoxidation of Propylene to Propylene Oxide on a Supported Catalyst Modified with Various Dopants

In the present study, the production of propylene oxide (PO) from propylene via gas-phase epoxidation was investigated using various catalysts. Although Ag is known to be a highly active catalyst for the epoxidation of ethylene, it was not active in the present reaction. Both Al and Ti showed high levels of activity, however, which resulted in confusion. The present study was conducted to solve such confusion. Although the employment of MCM-41 modified with Ti and/or Al was reported as an active catalyst for epoxidation, the combination resulted in the formation of PO at a less than 0.1% yield. Since this research revealed that the acidic catalyst seemed favorable for the formation of PO, versions of ZSM-5 that were both undoped and doped with Na, Ti, and Ag were used as catalysts. In these cases, small improvements of 0.67% and 0.57% were achieved in the PO yield on H‒ZSM-5 and Ti‒ZSM-5, respectively. Based on the results of the Ti-dopant and acidic catalysts, Ag metal doped on carbonate species with a smaller surface area was used as a catalyst. As reported, Ag‒Na/CaCO3 showed a greater yield of PO at 1.29%. Furthermore, the use of SrCO3 for CaCO3 resulted in a further improvement in the PO yield to 2.17%. An experiment using CO2 and NH3 pulse together with SEM and TEM examinations for Ag‒Na/CaCO3 revealed that the greatest activity was the result of the greater particle size of metallic Ag rather than the acid‒base properties of the catalysts

Clinical usefulness of super high-resolution liquid crystal displays using independent sub-pixel driving technology

金沢大学医薬保健研究域保健学系We have developed and reported super-high resolution liquid crystal displays (SHR-LCDs) using a new resolution enhancement technology of the independent sub-pixel driving (ISD) that utilizes three sub-pixels contained in each pixel element. This technology realizes the three-times resolution enhancement of monochrome LCDs. A 15 mega-pixel (MP) SHR-LCD out of a 5MP LCD and a 9MP SHR-LCD out of a 3MP LCD, for example, are realized by this technology, which improves the depiction ability of detailed image shapes such as micro-calcifications of a mammography. Furthermore, the ISD technology brings not only resolution enhancement but also noise reduction effect by the high-frequency data sampling in displaying the clinical images. In this study, we have investigated the clinical efficacy of the SHR-LCDs by means of phantom observation studies and blind observer comparison studies using clinical mammography images performed by radiologists. We used a conventional 5MP LCD for a comparison of a 15MP SHR-LCD and a 9MP SHR-LCD to evaluate their efficacy. From the results of the studies, it was indicated that the SHR-LCDs using the ISD technology had the excellent ability to display the high-resolution digital mammography images. © 2008 Springer-Verlag Berlin Heidelberg

Incidence of Pulmonary Complications with the Prophylactic Use of High-flow Nasal Cannula after Pediatric Cardiac Surgery: Prophylactic HFNC Study Protocol

We will investigate the incidence of postoperative pulmonary complications (PPCs) with the prophylactic use of a high-flow nasal cannula (HFNC) after pediatric cardiac surgery. Children < 48 months old with congenital heart disease for whom cardiac surgery is planned will be included. The HFNC procedure will be commenced just after extubation, at a flow rate of 2 L/kg/min with adequate oxygen concentration to achieve target oxygen saturation ≥ 94%. This study will reveal the prevalence of PPCs after pediatric cardiac surgery with the prophylactic use of HFNC

Nationwide patient registry for GNE myopathy in Japan

BACKGROUND: GNE myopathy is a slowly progressive autosomal recessive myopathy caused by mutations in the GNE (glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase) gene. This study aimed to (1) develop a nationwide patient registry for GNE myopathy in order to facilitate the planning of clinical trials and recruitment of candidates, and (2) gain further insight into the disease for the purpose of improving therapy and care. METHODS: Medical records of genetically-confirmed patients with GNE myopathy at the National Center Hospital of the National Center of Neurology and Psychiatry (NCNP) were retrospectively reviewed in order to obtain data reflecting the severity and progression of the disease. We also referred to items in the datasheet of the nationwide registry of dystrophinopathy patients in the Registry of Muscular Dystrophies (Remudy). Items selected for the registration sheet included age, sex, age at onset, past history and complications, family history, body weight and height, pathological findings of muscle biopsy, grip power, walking ability, respiratory function, cardiac function, willingness to join upcoming clinical trials, and participation in patient associations. A copy of the original genetic analysis report was required of each patient. RESULTS: We successfully established the Remudy-GNE myopathy. Currently, 121 patients are registered nationwide, and 93 physicians from 73 hospitals collaborated to establish the registry. The mean age at onset was 27.7 ± 9.6 years, and 19.8% (24/121) of patients could walk without assistance. Mean presumed durations from onset to use of assistive devices (cane and/or braces) and a wheelchair, and loss of ambulation were 12.4, 15.2, and 21.1 years, respectively. Three patients had a past history and/or complication of idiopathic thrombocytopenia. To share the progress of this study with the community, newsletters were published on a regular basis, and included information regarding new phase I clinical trials for GNE myopathy. The newsletters also served as a medium to bring attention to the importance of respiratory evaluation and care for respiratory insufficiency. CONCLUSION: The Japanese Remudy-GNE myopathy is useful for clarifying the natural history of the disease and recruiting patients with genetically-confirmed GNE myopathy for clinical trials. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13023-014-0150-4) contains supplementary material, which is available to authorized users

Evaluation of a point-of-care serum creatinine measurement device and the impact on diagnosis of acute kidney injury in pediatric cardiac patients: A retrospective, single center study

Background and aims: Agreement between measurements of creatinine concentrations using point-of-care (POC) devices and measurements conducted in a standard central laboratory is unclear for pediatric patients. Our objectives were (a) to assess the agreement for pediatric patients and (b) to compare the incidence of postoperative acute kidney injury (AKI) according to the two methods. Methods: This retrospective, single-center study included patients under 18 years of age who underwent cardiac surgery and who were admitted into the pediatric intensive care unit of a tertiary teaching hospital (Okayama University Hospital, Japan) from 2013 to 2017. The primary objective was to assess the correlation and the agreement between measurements of creatinine concentrations by a Radiometer blood gas analyzer (Cre(gas)) and those conducted in a central laboratory (Cre(lab)). The secondary objective was to compare the incidence of postoperative AKI between the two methods based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. Results: We analyzed the results of 1404 paired creatinine measurements from 498 patients, whose median age was 14 months old (interquartile range [IQR] 3, 49). The Pearson correlation coefficient of Cre(gas) vs Cre(lab) was 0.968 (95% confidence interval [CI], 0.965-0.972, P Conclusion: There was an excellent correlation between Cre(gas) and Cre(lab) in pediatric patients. Although more patients were diagnosed as having postoperative AKI based on Cre(gas) than based on Cre(lab), paired measurements with a short time gap showed good agreement on AKI diagnosis

16S rRNA Methylase–producing, Gram-Negative Pathogens, Japan

To investigate the exact isolation frequency of 16S rRNA methylase–producing, gram-negative pathogenic bacteria, we tested 87,626 clinical isolates from 169 hospitals. Twenty-six strains from 16 hospitals harbored 16S rRNA methylase genes, which suggests sparse but diffuse spread of pan-aminoglycoside–resistant microbes in Japan

Carcinoma Arising from Brunner's Gland in the Duodenum after 17 Years of Observation – A Case Report and Literature Review

A 60-year-old man presented with melena and hematemesis in 1984. Esophagogastroduodenoscopy (EGD) detected a small protruding lesion in the duodenal bulb, which was diagnosed as Brunner's adenoma. No significant change was detected in subsequent annual EGD and biopsies for 10 years, after which the patient was not observed for 7 years. The patient presented with melena again in 2001. The lesion had changed shape to become a 10 mm sessile tumor with a central depression, and following a biopsy was diagnosed as an adenocarcinoma. The patient underwent partial resection of the duodenum. Histopathological assessment showed acidophilic cells with swollen nuclei, and clear cells forming a tubular or papillary tubule in the mucosal lamina propria and submucosal layer. The tumor cells stained positive for lysozyme, indicating that they arose from Brunner's gland. The patient showed no sign of recurrence and was disease-free for more than 34 months after surgery. The patient died of pneumonia. This is an extremely rare case of primary duodenal carcinoma arising from Brunner's gland in a patient observed for 17 years