One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

The Bohlmann–Rahtz pyridine synthesis and the Hantzsch dihydropyridine synthesis can be carried out in a microwave flow reactor or using a conductive heating flow platform for the continuous processing of material. In the Bohlmann–Rahtz reaction, the use of a Brønsted acid catalyst allows Michael addition and cyclodehydration to be carried out in a single step without isolation of intermediates to give the corresponding trisubstituted pyridine as a single regioisomer in good yield. Furthermore, 3-substituted propargyl aldehydes undergo Hantzsch dihydropyridine synthesis in preference to Bohlmann–Rahtz reaction in a very high yielding process that is readily transferred to continuous flow processing

Freeform Extrusion of High Solids Loading Ceramic Slurries, Part I: Extrusion Process Modeling

A novel solid freeform fabrication method has been developed for the manufacture of ceramic-based components in an environmentally friendly fashion. The method is based on the extrusion of ceramic slurries using water as the binding media. Aluminum oxide (Al2O3) is currently being used as the part material and solids loading as high as 60 vol. % has been achieved. This paper describes a manufacturing machine that has been developed for the extrusion of high solids loading ceramic slurries. A critical component of the machine is the deposition system, which consists of a syringe, a plunger, a ram actuated by a motor that forces the plunger down to extrude material, and a load cell to measure the extrusion force. An empirical, dynamic model of the ceramic extrusion process, where the input is the commanded ram velocity and the output is the extrusion force, is developed. Several experiments are conducted and empirical modeling techniques are utilized to construct the dynamic model. The results demonstrate that the ceramic extrusion process has a very slow dynamic response, as compared to other non-compressible fluids such as water. A substantial amount of variation exists in the ceramic extrusion process, most notably in the transient dynamics, and a constant ram velocity may either produce a relatively constant steady-state extrusion force or it may cause the extrusion force to steadily increase until the ram motor skips. The ceramic extrusion process is also subjected to significant disturbances such as air bubble release, which causes a dramatic decrease in the extrusion force, and nozzle clogging, which causes the extrusion force to slowly increase until the clog is released or the ram motor skips.Mechanical Engineerin

Freeform Extrusion of High Solids Loading Ceramic Slurries, Part II: Extrusion Process Control

Part I of this paper provided a detailed description of a novel fabrication machine for high solids loading ceramic slurry extrusion and presented an empirical model of the ceramic extrusion process, with ram velocity as the input and extrusion force as the output. A constant force is desirable in freeform extrusion processes as it correlates with a constant material deposition rate and, thus, good part quality. The experimental results in Part I demonstrated that a constant ram velocity will produce a transient extrusion force. In some instances the extrusion force increased until ram motor skipping occurred. Further, process disturbances, such as air bubble release and nozzle clogging that cause sudden changes in extrusion force, were often present. In this paper a feedback controller for the ceramic extrusion process is designed and experimentally implemented. The controller intelligently adjusts the ram motor velocity to maintain a constant extrusion force. Since there is tremendous variability in the extrusion process characteristics, an on-off controller is utilized in this paper. Comparisons are made between parts fabricated with and without the feedback control. It is demonstrated that the use of the feedback control reduces the effect of process disturbances (i.e., air bubble release and nozzle clogging) and dramatically improves part quality.Mechanical Engineerin

Distal thoracic oesophageal perforation secondary to blunt trauma: Case report

BACKGROUND: Traumatic perforation of the distal oesophagus due to blunt trauma is a very rare condition and is still associated with a significant morbidity and mortality. This is further exacerbated by delayed diagnosis and management as symptoms and signs are often masked by or ascribed to more common blunt thoracic injuries. CASE REPORT: We present a case of a distal oesophageal perforation, secondary to a fall from a third storey window, which was masked by concomitant thoracic injuries and missed on both computed tomography imaging and laparotomy. The delay in his diagnosis significantly worsened the patient's recovery by allowing the development of an overwhelming chest sepsis that contributed to his death. CONCLUSION: Early identification of an intrathoracic oesophageal perforation requires deliberate consideration and is essential to ensure a favorable outcome. Treatment should be individualised taking into account the nature of the oesophageal defect, time elapsed from injury and the patient's general condition

Aqueous-Based Extrusion Fabrication of Ceramics on Demand

Aqueous-Based Extrusion Fabrication is an additive manufacturing technique that extrudes ceramic slurries of high solids loading layer by layer for part fabrication. The material reservoir in a previously developed system has been modified to allow for starting and stopping of the extrusion process on demand. Design pros and cons are examined and a comparison between two material reservoir designs is made. Tests are conducted to determine the optimal deposition parameters for starting and stopping the extrudate on demand. The collected test data is used for the development of a deposition strategy that improves material deposition consistency, including reduced material buildup at sharp corners. Example parts are fabricated using the deposition strategy and hardware design.Mechanical Engineerin

Recurrent laryngeal nerve palsy due to impacted dental plate in the thoracic oesophagus: case report

<p>Abstract</p> <p>Background</p> <p>Retained oesophageal foreign bodies must be urgently removed to prevent potentially serious complications. Recurrent laryngeal nerve palsy is rare and has not been reported in association with a foreign body in the thoracic oesophagus.</p> <p>Case presentation</p> <p>We present a case of a dental plate in the thoracic oesophagus that caused high dysphagia. Delayed diagnosis led to a recurrent laryngeal nerve palsy, which persisted despite successful surgical removal of the foreign body.</p> <p>Conclusion</p> <p>Oesophagoscopy is essential to fully assess patients with persistent symptoms after foreign body ingestion, irrespective of the level of dysphagia. Recurrent laryngeal nerve palsy may indicate impending perforation and should prompt urgent evaluation and treatment.</p

Stress in Rural North Georgia Policing

There are many operational and organizational stressors in policing. This study was designed to gain a better understanding of what causes police officers in a rural southern state mental and physical stress and to determine how best to assist officers when they are dealing with stress. The purpose of this study was to determine whether organizational or operational issues cause more stress among police officers in a rural southern state. Qualitative research methods and the phenomenological approach to obtain data from participants who have experienced job-related stressors were used. The social construct theory, a theory of knowledge in sociology, was used for this study. Data were collected by conducting interviews with 14 current police officers in a rural southern state with a minimum of two years of experience in rural policing. The in-vivo coding method was used to code the interview data in MAXQDA software. The study revealed that 13 of the 14 participants attributed organizational issues as their main stress factor. The findings from this study may result in positive social change for police officers and subsequently the communities they serve. The police department and the community benefit when officers are in good physical and mental health. Gaining an understanding of what factors contribute to officers\u27 stress and determining ways to treat the effects of stress could contribute to positive social change by having psychologically and emotionally healthy officers on the street and that could strengthen the partnership between a police department and the community it serves

Japanese multinationals in the post-bubble era:new challenges and evolving capabilities

Since the bursting of Japan's bubble economy, from 1990 onwards, Japanese multinational companies (MNCs) have faced new competitive challenges and questions about the management practices on which they had built their initial success in global markets. Japanese engagement in the international economy has undergone a number of phases. In the period before the Second World War, Japanese companies learnt from foreign MNCs in trading, shipping, and manufacturing, frequently through strategic alliances, and leveraged their capabilities to succeed in overseas and largely Asian markets. In the immediate post-war decades, during the Japanese ‘economic miracle’, there were notable examples of MNC investment in raw materials and labour intensive production, but both inward and outward foreign direct investment were not significant. Japanese companies achieved leadership in management and technology, in order to support a strategy of export-orientated industrialization. Changes in government policies in the developed economies of the US and Western Europe forced leading Japanese manufacturers to convert themselves into MNCs and to transfer their home-grown capabilities to overseas subsidiaries. The period after 1990 marked declining Japanese competitiveness and it asked questions about the ability of Japanese MNCs to be more responsive and global in their strategies, organization and capabilities.No Full Tex

Collaboration Makes More Lights Come on than Those on the Runway: Experiential Learning through an Interdisciplinary Fashion Show Project Merges Fashion and Technology

Inspired by the Metropolitan Museum of Art exhibit, Manus x Machina: Fashion in an Age of Technology, the idea for the theme Futuristic Floral was born to guide the direction of the Apparel Merchandising and Product Development (AMPD) fashion show. In only the second year of production, we wanted to make sure the show would entertain the audience and be a professional production. However, as educators, our primary goal was to make a lasting impact on the education of our students. This project has pushed our students to think, act, communicate, and create on a level that would not have been possible without the interaction of students from apparel and electrical engineering. The true impact for all students involved remains to be seen when the lights go down after the show and they realize they have been a part of something much bigger than they could create on their own