Automatic heart-rate-based selection of pedal load and control system for electric cart

This paper describes an autoselection method for the pedal load of an electric cart, and the control system. The method checks the driver’s physical condition just before the start of driving, calculates the driver’s rating of perceived exertion, and uses that to automatically select a suitable pedal load. To ensure that the level of physical exertion is safe, the largest pedal load is determined on the basis of Borg’s CR10, the Karvonen formula, a pedaling experiment, and statistical data. A driver’s degree of fatigue is estimated from his heart rate, and a pedal load (between the largest and almost zero) is automatically selected. In addition, a dynamic output-feedback cart control system was designed that guarantees the stability of the cart system for any allowable pedal load. A stability condition is derived by employing the concept of dynamic parallel distributed compensation. Finally, experiments demonstrate the validity of the method.     

Carbon-supported tetragonal MnOOH catalysts for oxygen reduction reaction in alkaline media

Carbon-supported MnOOH catalyst was prepared by reducing KMnO₄ with carbon Black Pearls 2000. TEM and XRD characterization results show that nanosized tetragonal MnOOH crystals formed in the specimen when the MnOOH content ranged from 9 wt.% to 36 wt.%. The oxygen reduction reaction (ORR) activity of the catalyst with different amounts of MnOOH content in alkaline media was investigated using a rotating disc electrode (RDE) and a rotating ring-disc electrode (RRDE). The number of electrons involved in the ORR increased from 3.2 to 3.9 with the increase of the MnOOH content from 9 wt.% to 36 wt.% in the catalyst. The kinetic current increased to 0.0184 A cm⁻² when the MnOOH content was increased to 72 wt.%. However, both the number of electrons and the kinetic current decreased when the MnOOH content was increased from 72 wt.% to 90 wt.%. The MnOOH/C catalyst with optimized MnOOH content and suitable loading in the cathode is promising for applications in alkaline fuel cells.     

New Insights in the Pathogenesis of Multiple Sclerosis—Role of Acrolein in Neuronal and Myelin Damage

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by an inappropriate inflammatory reaction resulting in widespread myelin injury along white matter tracts. Neurological impairment as a result of the disease can be attributed to immune-mediated injury to myelin, axons and mitochondria, but the molecular mechanisms underlying the neuropathy remain incompletely understood. Incomplete mechanistic knowledge hinders the development of therapies capable of alleviating symptoms and slowing disease progression in the long-term. Recently, oxidative stress has been implicated as a key component of neural tissue damage prompting investigation of reactive oxygen species (ROS) scavengers as a potential therapeutic option. Despite the establishment of oxidative stress as a crucial process in MS development and progression, ROS scavengers have had limited success in animal studies which has prompted pursuit of an alternative target capable of curtailing oxidative stress. Acrolein, a toxic β-unsaturated aldehyde capable of initiating and perpetuating oxidative stress, has been suggested as a viable point of intervention to guide the development of new treatments. Sequestering acrolein using an FDA-approved compound, hydralazine, offers neuroprotection resulting in dampened symptom severity and slowed disease progression in experimental autoimmune encephalomyelitis (EAE) mice. These results provide promise for therapeutic development, indicating the possible utility of neutralizing acrolein to preserve and improve neurological function in MS patients.     

Solvent-free selective oximation of aldehydes using facile and reusable heterogenous polyoxometalate

The efficiency of various heteropoly compounds as well-known solid acids was investigated and a new procedure was developed for synthesis of Z-isomers of aldoximes. This method consistently has the advantage of excellent yields and short reaction times. Furthermore, the catalyst could be easily recovered after completion of the reaction and reused without a considerable loss of its activity.     

Integrated micro- and miniscale electromechanical systems with permanent-magnet servo-motors and VLSI drivers–controllers

The current trends in development and deployment of advanced micro- and miniscale electromechanical systems (MEMS) have facilitated the unified fundamental, applied, and experimental research activities in the analysis and design of state-of-the-art motion devices (rotational and translational electromechanical motion devices), integrated circuits (ICs), and controllers. The objectives of this paper are to design, develop, and compare different control algorithms for high-performance MEMS with permanent-magnet rotational servo-motors controlled by ICs (VLSI driver–controller is fabricated using CMOS technology). The problems to be solved are very challenging because a number of long-standing issues in design, hardware integration, control, nonlinear analysis, and robustness have to be solved. The major emphases of this paper are the analysis and design of robust servo-systems, as well as the comparison of the dynamic performance of closed-loop MEMS with different control algorithms. We synthesize, verify, and test proportional–integral, integral with state feedback extension, relay, and sliding mode controllers. It is illustrated that the sliding mode control laws drive the states and tracking error to the switching surface and maintain (keep) the states and tracking error within this nonlinear switching surface in spite of different references, disturbances, parameter variations, and uncertainties. That is, robust tracking, desired accuracy, and disturbance attenuation are achieved. We report the experimental setup which was built to perform the advanced studies of high-performance MEMS. The testbed was built to integrate permanent-magnet microscale servo-motor and ICs (driver–controller).     

Statistical characterization of a real video on demand service: User behaviour and streaming-media workload analysis

The video on demand service characterized in this article has surpassed 4 years of service, and the access log database stores information of more than 160,000 reproductions and 900 videos. The wide variety of subjects, the range of content lengths and a frequent update of contents (several new videos every day), clearly differentiate this study from other previous research limited to specific users, subjects or environments. We present a statistical study of user behaviour and streaming traffic, analyzing session characteristics, mistaken reproductions, amount of media delivered, number and length of pauses and jumps in the reproduction, popularity and daily access profile. The results of the analysis will allow us to develop simulation models and workload generators to evaluate different scenarios and situations of the service.     

Determination of Most Economical Scrapers Fleet

Scrapers are valuable construction equipment for large earthmoving operations. Their production rates vary widely as they depend on the equipment performance, operation’s travel time, and haul-road conditions. Determining the most economical selection of the size, model, and number of scrapers is a rather tedious process that involves repetitive calculations. A spreadsheet application was created in order to facilitate such calculations and select the most economical scraper from the list of available equipment for the job under consideration. The application is made of seven spreadsheets containing a scrapers’ database, performance charts, soil properties, and other supporting worksheets. The application provides a user interface to solicit all data entries specific to a project. Once the user enters the required data the system compares the production rate, time required for the job, determines the estimated unit cost for each scraper in the database, and recommends the most economical selection.     

Development of Selective Inhibitors for Human Aldehyde Dehydrogenase 3A1 (ALDH3A1) for the Enhancement of Cyclophosphamide Cytotoxicity

Aldehyde dehydrogenase 3A1 (ALDH3A1) plays an important role in many cellular oxidative processes, including cancer chemoresistance, by metabolizing activated forms of oxazaphosphorine drugs such as cyclophosphamide (CP) and its analogues, such as mafosfamide (MF), ifosfamide (IFM), and 4‐hydroperoxycyclophosphamide (4‐HPCP). Compounds that can selectively target ALDH3A1 could permit delineation of its roles in these processes and could restore chemosensitivity in cancer cells that express this isoenzyme. Here we report the detailed kinetic and structural characterization of an ALDH3A1‐selective inhibitor, CB29, previously identified in a high‐throughput screen. Kinetic and crystallographic studies demonstrate that CB29 binds within the aldehyde substrate‐binding site of ALDH3A1. Cellular proliferation of ALDH3A1‐expressing lung adenocarcinoma (A549) and glioblastoma (SF767) cell lines, as well as ALDH3A1 non‐expressing lung fibroblast (CCD‐13Lu) cells, is unaffected by treatment with CB29 and its analogues alone. However, sensitivity toward the anti‐proliferative effects of mafosfamide is enhanced by treatment with CB29 and its analogue in the tumor cells. In contrast, the sensitivity of CCD‐13Lu cells toward mafosfamide was unaffected by the addition of these same compounds. CB29 is chemically distinct from the previously reported small‐molecule inhibitors of ALDH isoenzymes and does not inhibit ALDH1A1, ALDH1A2, ALDH1A3, ALDH1B1, or ALDH2 isoenzymes at concentrations up to 250 μM . Thus, CB29 is a novel small molecule inhibitor of ALDH3A1, which might be useful as a chemical tool to delineate the role of ALDH3A1 in numerous metabolic pathways, including sensitizing ALDH3A1‐positive cancer cells to oxazaphosphorines.     

Design and analysis of noise margin,write ability and read stability of organic and hybrid 6-T SRAM cell

This paper analyzes SRAM cell designs based on organic and inorganic thin film transistors (TFTs). The performance in terms of static noise margin (SNM), read stability and write ability for all-p organic (Pentacene–Pentacene), organic complementary (Pentacene–C₆₀) and hybrid complementary (Pentacene–ZnO) configurations of SRAM cell is evaluated using benchmarked industry standard Atlas 2-D numerical device simulator. Moreover, the cell behaviour is analyzed at different cell and pull-up ratios. The electrical characteristics and performance parameters of individual TFT used in SRAM cell is verified with reported experimental results. Furthermore, the analytical result for SNM of all-p organic SRAM cell is validated with respect to the simulated result. Besides this, the cell and pull-up ratios of the hybrid and organic SRAM cells are optimized for achieving best performance of read and write operations and thereafter, the results are verified analytically also. The SNM of hybrid cell is almost two times higher than the all-p SRAM, whereas this improvement is just 18% in comparison to the organic memory cell. On the other hand, the organic complementary SRAM cell shows an improvement of 26% and 22% for the read stability in comparison to the all-p organic and hybrid SRAM cells, respectively. Contrastingly, this organic cell demonstrates a reduction of 16% in the SNM and an increment of 76% in write access time in comparison to the hybrid cell. To achieve an overall improved performance, the organic complementary SRAM cell is designed such that the access transistors are pentacene based p-type instead of often used n-type transistor. Favorably, this organic SRAM design shows reasonably lower write access time in comparison to the cell with n-type access OTFTs. Moreover, this cell shows adequate SNM and read stability that too at substantially lower width of p-type access OTFTs.     

Docosahexaenoic acid increases permeability of lipid vesicles and tumor cells

Docosahexaenoic acid (DHA), a long-chain polyunsaturated ω3 fatty acid, is tested to determine its mode of action as an anti-cancer agent. We demonstrate that DHA can increase the permeability of phospholipid vesicles, as monitored by vesicle swelling in isomolar erythritol and leakage of sequestered carboxylfluorescein, and T27A tumor cells, as monitored by swelling in isomolar erythritol and release of sequestered⁵¹Cr. DHA was incorporated into lipid vesicles as either the free fatty acid or as 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine. DHA was incorporated into the tumor cells by fusion with vesicles made from the mixed-chain phosphatidylcholines. DHA is demonstrated here to be much more effective in increasing permeability than is oleic acid, the major unsaturated fatty acid normally found in tumor plasma membranes. It is proposed that incorporation of DHA makes tumor plasma membranes substantially more permeable, which may explain, in part, its anti-tumor properties.