Some New Chemicals for Rubber and Their Reactivities as Free Radical Sources

The present paper is concerned with investigations about some new chemicals for rubber processing. The actions of the chemicals were classified into several types according to their selective activities. Chemicals having the tendency to abstract hydrogen atom from rubber molecules act as crosslinking agents or peptizers according to the nature of the radical produced and to the presence of oxygen. Benzoyl disulfide and diazothioether were found to be new vulcanizing agents and the quaternary ammonium salts of the aromatic series, sulfinic acids and alkyl nitrites were new peptizers for rubber. The chemicals composed of stable radical species acting as acceptors for sulfur radicals were found to be antiscorch agents. Chloro- or nitroso-compounds of imide, imine, alcohol, or mercaptan were found to have such characters. Aliphatic quaternary salts producing radicals with moderate activity on heating may open the sulfur rings. The vulcanization characteristics of some synthetic rubbers were found to be improved by using of some modifiers such as thioacetamide, trichloroisocyanuric acid, and trichloromelamine

A MOLECULAR THEORY OF FILLER REINFORCEMENT BASED UPON THE CONCEPTION OF INTERNAL DEFORMATION : A ROUGH APPROXIMATION OF THE INTERNAL DEFORMATION

ArticleJournal of the Faculty of Textile Science and Technology, Shinshu University. Ser. F, Physics and mathematics 1: 1-26(1962)departmental bulletin pape

An Attempt to Estimate the Charge Distribution in Sigma-Bond Systems

A classical inductive-effect model has been utilized in an attempt to estimate the change distribution in relatively complicated σ-bond systems. It is assumed that the formal charge on an atom is given as a vectorial sum of the polarities of the bonds attached to that atom and, further, that each bond induces a constant fraction of its own polarity in all of its neighboring bonds. Significance of the model has been tested for several model compounds which permit the closed-form solutions for the distributions of the internally self-consistent bond polarities. The model has been applied to the calculations of the charge distributions in alkanes, ｫ-alkyl halides and hydrated metallic ions ; the results are found to be compatible with observations

High-power, continuous-wave, scalable, single-frequency 852nm laser source for 213nm generation

We developed a high-power, continuous-wave (CW), single-frequency 852nm laser source, for the purpose of fourth harmonic generation at 213nm. Our approach is the doubly resonant sum-frequency mixing (DRSFM) with two fiber sources. An in-house single-frequency master oscillator at 1907nm is amplified by an in-house clad-pumped amplifier to 5W, and a commercial single-frequency master oscillator at 1540nm is amplified by a commercial amplifier to 10W. The two beams are combined via a dichroic mirror to a single beam before incident on a dual-wavelength resonator, consisting of one set of dual-wavelength mirrors. The external resonator is locked to the 1907nm laser frequency, and the frequency of the 1540nm is locked to the resonator, realizing double-resonance. With a periodically-poled stoichiometric lithium tantalate in the resonator, the sum-frequency at 852nm is efficiently generated. All 3 waves are in the same polarization (e-ray), allowing the effective use of Brewster-cut device, eliminating reflection loss for all wavelengths without any antireflection coatings. With 4.6W at 1907nm and 7.7W at 1540nm incident onto the resonator, 5.2W at 852nm was generated, representing the efficiency of greater than 40%. The experimental result indicates our current setup will be more efficient with higher input powers at 1907nm. With both fiber sources at 1540nm and 1907nm being scalable in output power, the output at 852nm is also scalable. By the forth harmonic of 852nm, 0.456 W CW 213nm was generated.New Energy and Industrial Technology Development Organization (NEDO) of JapanThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Scalable Approach for Continuous-Wave Deep-Ultraviolet Laser at 213nm

We present a novel approach for generation at 213nm in continuous-wave, corresponding to the fifth harmonic of common 1064nm laser, in pure continuous-wave mode. The approach is scalable in output power. Starting from two infrared fiber laser sources, we demonstrated 0.456W output at 213nm. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing AgreementOpen access journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Single-Stage Endoscopic Stone Extraction and Cholecystectomy during the Same Hospitalization

Background/Aims The clinical impact of single-stage endoscopic stone extraction by endoscopic retrograde cholangiopancreatography (ERCP) and cholecystectomy during the same hospitalization remains elusive. This study aimed to determine the efficacy and safety of single-stage ERCP and cholecystectomy during the same hospitalization in patients with cholangitis. Methods We retrospectively reviewed the medical records of 166 patients who underwent ERCP for mild to moderate cholangitis due to choledocholithiasis secondary to cholecystolithiasis from 2012 to 2016. Results Complete stone extraction was accomplished in 92% of patients (152/166) at the first ERCP. Among 152 patients who underwent complete stone extraction, cholecystectomy was scheduled for 119 patients (78%). Cholecystectomy was performed during the same hospitalization in 89% of patients (106/119). We compared two groups of patients: those who underwent cholecystectomy during the same hospitalization (n=106) and those who underwent cholecystectomy during a subsequent hospitalization (n=13). In the delayed group, cholecystectomy was performed about three months after the first ERCP. There were no significant differences between the groups in terms of operative time, rate of postoperative complications, and interval from cholecystectomy to discharge. Conclusions Single-stage endoscopic stone extraction is recommended in patients with mild to moderate acute cholangitis due to choledocholithiasis. The combination of endoscopic stone extraction and cholecystectomy during the same hospitalization is safe and feasible

Clinical application of scaffolds for cartilage tissue engineering

The purpose of this paper is to review the basic science and clinical literature on scaffolds clinically available for the treatment of articular cartilage injuries. The use of tissue-engineered grafts based on scaffolds seems to be as effective as conventional ACI clinically. However, there is limited evidence that scaffold techniques result in homogeneous distribution of cells. Similarly, few studies exist on the maintenance of the chondrocyte phenotype in scaffolds. Both of which would be potential advantages over the first generation ACI. The mean clinical score in all of the clinical literature on scaffold techniques significantly improved compared with preoperative values. More than 80% of patients had an excellent or good outcome. None of the short- or mid-term clinical and histological results of these tissue-engineering techniques with scaffolds were reported to be better than conventional ACI. However, some studies suggest that these methods may reduce surgical time, morbidity, and risks of periosteal hypertrophy and post-operative adhesions. Based on the available literature, we were not able to rank the scaffolds available for clinical use. Firm recommendations on which cartilage repair procedure is to be preferred is currently not known on the basis of these studies. Randomized clinical trials and longer follow-up periods are needed for more widespread information regarding the clinical effectiveness of scaffold-based, tissue-engineered cartilage repair