Mechanical Instrumentation Research Articles

Applications of IoT in Manufacturing: Issues and Challenges

The Internet of Things (IoT) is the global network of inter-related physical devices such as sensors, objects, computing devices, mechanical instruments, smart applications and human resources that are becoming an essential part of the internet. These devices are the sources of data which provide abundant information in manufacturing processes. In an industrial environment, the Industrial Internet of Things (IIoT) plays a pivotal role in manufacturing. IIoT is the transformation of manufacturing process by making the industries more efficient, productive, and smarter. In order to survive, withstand in the market place and gain competitive advantage, the manufacturers are initiating to leverage IIoT technologies and data analytics. With globalization, global competitive pressures are challenging industries and manufacturing companies to manage the gaps in the workforce skills, drive out inefficiencies from the existing systems and enhance their business opportunities. The world is plunging into an era of data inter-connectivity and companies are able to enhance their production after adapting new technologies. In this context, this paper provides an understanding of the concept of IIoT and smart manufacturing. Further, the paper discusses in detail the issues concerning different applications of IoT in the industrial sector; and presents the challenges encountered in an IoT-based Industrial Data Management System (IDMS), which can manage the huge industrial data, support online monitoring and control smart manufacturing.

Clinical and imaging features of surgically treated low lumbar osteoporotic vertebral collapse in patients with Parkinson\u2019s disease

Osteoporosis and Parkinson’s disease (PD) are age-related diseases, and surgery for osteoporotic vertebral collapse (OVC) in PD patients become more common. OVC commonly affects the thoracolumbar spine, but low lumbar OVC is frequent in patients with lower bone mineral density (BMD). The aim of this study was to identify differences in clinical and imaging features of low lumbar OVC with or without PD and to discuss the appropriate treatment. The subjects were 43 patients with low lumbar OVC below L3 who were treated surgically, including 11 patients with PD. The main clinical symptoms were radicular pain in non-PD cases and a cauda equina sign in PD cases. Rapid progression and destructive changes of OVC were seen in patients with PD. The morphological features of OVC were flat-type in non-PD cases with old compression fracture, and destruction-type in PD cases without old compression fracture. Progression of PD was associated with decreased lumbar lordosis, lower lumbar BMD, and severe sarcopenia. High postoperative complication rates were associated with vertebral fragility and longer fusion surgery. Progression of postural instability as a natural course of PD may lead to mechanical stress and instrumentation failure. Invasive long-fusion surgery should be avoided for single low lumbar OVC.

Дискретно-подійне моделювання триангуляційних співвідношень складових робочого процесу лікаря-стоматолога при ендодонтичних маніпуляціях

Today in modern dentistry one of the urgent tasks is to increase the level of productivity of the dentist, while maintaining his or her mental and physical health. To find a rational solution to this issue, much attention is paid to ergonomics, which is aimed at protecting the work of doctors, improving the efficiency and quality of their work, creating optimal working conditions for them, ensuring safety and comfort for patients, and developing the latest dental equipment. The purpose of the study is to describe the clinical and experimental forecasting of the influence of ergonomics derivatives of dentists on the result of endodontic manipulations. Materials and methods. The methods, which were used, are targeted research methods, in particular Rapid Entire Body Assessment and Rapid Upper Limb Assessment, software Tecnomatix Jack (Siemens), StatPlusPro for Windows. The subject of research: a sample of 32 dentists (17 male dentists) (53.13%) and 15 female dentists (46.88%), who provide dental care on the basis of the University Dental Clinic, as well as in within other clinical bases of the dental faculty of Uzhhorod National University. Results and discussion. Analyzing the final results of iatrogenic interventions, there is a direct impact of ergonomics, justified by the presence of proven relationships between the integrated quality indicator of dental rehabilitation and procedural-manual-associated components of the treatment process. Non-compliance with the basic principles of ergonomics during various dental manipulations is evidence of changes in the pathological nature of the musculoskeletal system of the dentist, but there is still lack of data on the impact of the above changes on quantitative and qualitative indicators of effectiveness and predictability of treatment. Considerable attention needs to be paid to the analysis of the influence of ergonomic features of dentists' work on the result of endodontic treatment of teeth and their post-endodontic restoration, taking into account the initial complexity of this type of manipulation. As this is significantly influenced by anatomical variations in the structure of the endodontic, limited visualization of the working field, the need to ensure mandatory isolation of the intervention and permanent control over the absence of contamination of endodontic structures during treatment, topographic features of individual teeth (molars, in particular), features and physical characteristics of mechanical (rotational) and manual endodontic instruments. Conclusion. Occurrence of complications arising from endodontic treatment directly affect the prognosis of the dentition as a complex biomechanical system of the dental apparatus in cases of further post-endodontic restoration of teeth by direct or indirect restorations, as well as when using them as supports for future crowns, and also removable and non-removable types of orthopedic structures. In cases of fixation of bridges on endodontically treated teeth, the emergence of iatrogenic-associated complications due to biomechanical and biological properties of the endodontic, is associated with a decrease in the prognosis of success and survival of the entire prosthetic structure as a whole, rather than one independent unit of the tooth. Based on this, predicting the risks associated with the development of errors and complications during endodontic treatment, as well as their minimization through the use of various types of preventive measures remains an important scientific and practical issue not only therapeutic but also orthopedic dentistry

SA-SVM-Based Locomotion Pattern Recognition for Exoskeleton Robot

An exoskeleton robot is a kind of wearable mechanical instrument designed according to the shape and function of the human body. The main purpose of its design and manufacture is to enhance human strength, assist human walking and to help patients recover. The walking state of the exoskeleton robot should be highly consistent with the state of the human, so the accurate locomotion pattern recognition is the premise of the flexible control of the exoskeleton robot. In this paper, a simulated annealing (SA) algorithm-based support vector machine model is proposed for the recognition of different locomotion patterns. In order to improve the overall performance of the support vector machine (SVM), the simulated annealing algorithm is adopted to obtain the optimal parameters of support vector machine. The pressure signal measured by the force sensing resistors integrated on the sole of the shoe is fused with the position and pose information measured by the inertial measurement units attached to the thigh, shank and foot, which are used as the input information of the support vector machine. The max-relevance and min-redundancy algorithm was selected for feature extraction based on the window size of 300 ms and the sampling frequency of 100 Hz. Since the signals come from different types of sensors, normalization is required to scale the input signals to the interval (0,1). In order to prevent the classifier from overfitting, five layers of cross validation are used to train the support vector machine classifier. The support vector machine model was obtained offline in MATLAB. The finite state machine is used to limit the state transition and improve the recognition accuracy. Experiments on different locomotion patterns show that the accuracy of the algorithm is 97.47% ± 1.16%. The SA-SVM method can be extended to industrial robots and rehabilitation robots.

Robotic-assisted total knee arthroplasty improves accuracy and precision compared to conventional techniques.

Robotic-assisted total knee arthroplasty (RA-TKA) is theoretically more accurate for component positioning than TKA performed with mechanical instruments (M-TKA). Furthermore, the ability to incorporate soft-tissue laxity data into the plan prior to bone resection should reduce variability between the planned polyethylene thickness and the final implanted polyethylene. The purpose of this study was to compare accuracy to plan for component positioning and precision, as demonstrated by deviation from plan for polyethylene insert thickness in measured-resection RA-TKA versus M-TKA. A total of 220 consecutive primary TKAs between May 2016 and November 2018, performed by a single surgeon, were reviewed. Planned coronal plane component alignment and overall limb alignment were all 0° to the mechanical axis; tibial posterior slope was 2°; and polyethylene thickness was 9 mm. For RA-TKA, individual component position was adjusted to assist gap-balancing but planned coronal plane alignment for the femoral and tibial components and overall limb alignment remained 0 ± 3°; planned tibial posterior slope was 1.5°. Mean deviations from plan for each parameter were compared between groups for positioning and size and outliers were assessed. In all, 103 M-TKAs and 96 RA-TKAs were included. In RA-TKA versus M-TKA, respectively: mean femoral positioning (0.9° (SD 1.2°) vs 1.7° (SD 1.1°)), mean tibial positioning (0.3° (SD 0.9°) vs 1.3° (SD 1.0°)), mean posterior tibial slope (-0.3° (SD 1.3°) vs 1.7° (SD 1.1°)), and mean mechanical axis limb alignment (1.0° (SD 1.7°) vs 2.7° (SD 1.9°)) all deviated significantly less from the plan (all p < 0.001); significantly fewer knees required a distal femoral recut (10 (10%) vs 22 (22%), p = 0.033); and deviation from planned polyethylene thickness was significantly less (1.4 mm (SD 1.6) vs 2.7 mm (SD 2.2), p < 0.001). RA-TKA is significantly more accurate and precise in planning both component positioning and final polyethylene insert thickness. Future studies should investigate whether this increased accuracy and precision has an impact on clinical outcomes. The greater accuracy and reproducibility of RA-TKA may be important as precise new goals for component positioning are developed and can be further individualized to the patient. Cite this article: Bone Joint J2021;103-B(6 Supple A):74-80.

Acupuncture stimulation at HT7 as a non-pharmacological therapy for sleep disorder caused by caffeine administration in rats.

Insomnia is one of the most common sleep disorders and is difficult to completely treat because of the undesirable side effects of hypnotics. The present study was designed to investigate the hypnotic effect of acupuncture stimulation at HT7 on caffeine-induced sleep disorders and locomotor activity in rats. We also evaluated neuronal activity changes in the arousal region of the basal forebrain. Rats received intraperitoneal injections of caffeine, and then electroencephalogram power spectrum analysis and locomotor activity measurements were performed. Stimulation at HT7 was performed using a mechanical acupuncture instrument (MAI) before caffeine injection, and its effects on caffeine-induced changes in sleep architecture, locomotor activity and c-Fos expression were examined. Caffeine injection (7.5 mg/kg) produced a significant decrease in slow-wave sleep and an increase in wake time compared with saline injection. Caffeine injection also increased locomotor activity and c-Fos expression in the medial septum-vertical limb of the diagonal band of Broca (MS-VDB), one of the arousal regions of the basal forebrain. Stimulation at HT7 with the MAI alleviated the caffeine-induced sleep disturbance and the increase in locomotor activity. In addition, MAI treatment at HT7, compared with treatment at a location not corresponding to any traditional acupuncture point, reduced the caffeine-induced increase in c-Fos expression. These results indicate that the hypnotic effect of HT7 acupuncture stimulation on caffeine-induced insomnia was associated with suppression of neuronal activity in the basal forebrain.

Periodontal Decontamination Induced by Light and Not by Heat: Comparison between Oxygen High Level Laser Therapy (OHLLT) and LANAP

In periodontology, lasers have been suggested for the nonsurgical treatment of chronic periodontitis. Many wavelengths were tested, but unfortunately, most parts were not efficient. An Nd:YAG laser was applied in a specific protocol named the laser-assisted new attachment procedure (LANAP). LANAP seems to facilitate the refurbishment of new tissues from supporting structures of the periodontium, wherein the unhealthy surface of the roots exhibits pristine attachments in human beings. Photodynamic therapy (PDT) was investigated too. The aim of our study is to show the effects of oxygen high-level laser therapy (OHLLT) in removing all bacterial deposits on the root or implant surface by means of mechanical instrumentation and laser irradiation compared to LANAP and to nonsurgical debridement of periodontal pockets. At 7 days post-treatment, a real-time PCR test had similar results on the OHLLT and LANAP groups. After 9 months, all periodontal pockets were treated successfully, not showing significant differences in the clinical results between OHLLT and LANAP and with a decrease in the plaque index, bleeding on probing and probing depth compared with the nonsurgical debridement group.

Automated Quality Assessment of Interferometric Ring Laser Data.

In seismology, an increased effort to observe all 12 degrees of freedom of seismic ground motion by complementing translational ground motion observations with measurements of strain and rotational motions could be witnessed in recent decades, aiming at an enhanced probing and understanding of Earth and other planetary bodies. The evolution of optical instrumentation, in particular large-scale ring laser installations, such as G-ring and ROMY (ROtational Motion in seismologY), and their geoscientific application have contributed significantly to the emergence of this scientific field. The currently most advanced, large-scale ring laser array is ROMY, which is unprecedented in scale and design. As a heterolithic structure, ROMY’s ring laser components are subject to optical frequency drifts. Such Sagnac interferometers require new considerations and approaches concerning data acquisition, processing and quality assessment, compared to conventional, mechanical instrumentation. We present an automated approach to assess the data quality and the performance of a ring laser, based on characteristics of the interferometric Sagnac signal. The developed scheme is applied to ROMY data to detect compromised operation states and assign quality flags. When ROMY’s database becomes publicly accessible, this assessment will be employed to provide a quality control feature for data requests.

Multilayer Flexible Substrate Antenna Sensor for PT Measurement From Blood Plasma to Avoid Turbidity and Reagent Sensitivity Variations Through Regression Modelling

Passive antenna is applied in medical applications such as sensor, radiometer, rectenna, and implantable device for accurate measurement and analysis. Moreover, passive antennas can replace the optical sensors in the pathological instruments to overcome the drawbacks such as optical interference, offset voltage, time consumption and dark current. Furthermore, prothrombin time (PT) measurement through optical and mechanical instruments requires repeated testing for accurate results due to turbidity (lipemia) in blood Plasma and reagent sensitivity during coagulation. Plasma samples in instruments with more K vitamin influences the accuracy of PT measurements. In this paper, we propose a method to measure the PT from blood plasma through passive Ultra-Wideband sensor and overcomes the above problem. The proposed multilayer flexible substrate ultra-wide band (MFS-UWB) passive antenna absorbs the electromagnetic radiations from the concentration of plasma during clotting. The Concentration of plasma is proportional to electromagnetic energy density during clotting. The clotting duration time is acquired based on voltage. During clotting, observed electromagnetic emitted voltage is converted into frequency for measuring the clot concentration and the observed radiation from human blood clotting frequency ranges from 2GHz to 3GHz and voltage from 0.55mV to 0.85mV. The acquired blood clotting concentration voltage measures the prothrombin time using regression modelling and validated through laboratory values.

Influence of the Melt Extrusion Process on the Mechanical Behavior and the Thermal Properties of Ethylene Vinyl Alcohol Copolymer by Applying the Successive Self-nucleation and Annealing Thermal Fractionation

Ethylene vinyl alcohol copolymer was processed three times in a twin-screw extrusion pilot plant in order to reproduce the processing steps required to obtain EVOH nanocomposites. Thin film of the extruded EVOH was prepared by using a cast-film line. The melt flow index and rheological behavior of the film were determined. Viscoelastic parameters were evaluated in a dynamic mechanical testing instrument that revealed the presence of two signals, one attributed to the glass transition temperature and the other one related to the structural modifications associated to interlamellar separation. Thermal properties were evaluated in a differential scanning calorimetry by applying a standard evaluation and successive self-nucleation and annealing approach, finding structural modifications influenced by the melt extrusion process, although the overall percentage of crystallinity degree remains similar. Based on the structural results, the mechanical properties were evaluated considering the ethylene content and resulting on distinct mechanical behavior. Lower ethylene content allows the chain orientation induced during the processing of the film that favors the mechanical performance. Higher ethylene content promotes different deformation mechanisms and a relevant ductility.

Increase the functionality of vibration feeders with electromagnetic vibration

Under modern conditions vibrating hopper feeders with electromagnetic drive are irreplaceable when it comes to production processes in mechanical engineering and instrument making optimization processes. They are used to download small, medium or miniature details to automated technological equipment, such as automatic machines, automatic lines and automated complexes, or any other flexible automated production. The vibrating hopper loading devices are most commonly used in transportation and loading of details on working positions of assembly automatic machines and assembly automated complexes. In this case the details must be issued in a clearly oriented state. For this purpose, the stationary automated orienting devices, or the orienting devices located directly on the working vibrating feeders` bodies are used. Low compressed air pressure is often used in these devices. Apart from this, in some cases the low compressed air pressure is used in vibrating feeders to increase the maximum lifting angle when vibrating transportation of details on a transport tray of the feeder. We already know the designs of vibrating feeders, whose transport tray is equipped with channels and openings for the supply of compressed air, whose jets affect the parts that are transported in order to increase the maximum possible lifting angle or the speed of parts transportation, as well as to ensure the guaranteed gap between them at the download position. We also know the vibrating feeders` constructions equipped with jet pneumatic devices, which are set exactly on the vibrating feeder hopper and serve for non-contact orientation of details that are issued. All of these devices use the low compressed air supplied by means of the flexible pipeline from a workshop pneumatic network. But the fact that such network is simply absent in many enterprises` workshops makes it impossible to use the vibrating feeders like these, this way decreasing their use. For expanding their use it is necessary to have vibrating feeders with individual low pressure compressed air source. Modern production manufactures new models of machines with high technical economic indicators, so functionality increase of the existing one equipment and the development of new schemes of machines is an important task for designers and technological equipment manufacturers, because minimal improvement of its technological and performance can lead to a significant economic effect. The set of elements affecting the performance and efficiency of vibrating bunker feeders with electromagnetic drives that have a directional elastic system are presented in this paper. The additional structural elements increasing the functionality of such feeders are offered.

Retreatment of 6 Ceramic Restorations In A Single Session - The Application of Er:YAG Laser And CAD/CAM Technology: An 1 Year Follow Up Clinical Evaluation

Background: To present the benefits of high power lasers (Er: YAG and Nd: YAG) over the use of the high speed turbine for the extraction of ceramics restorations, without damaging the surfaces of the teeth; being a relatively easier and faster procedure without the use of anesthetic agents, and the preparation of the ceramic restorations and cementing in the single session; with a follow-up of 1 year. Objective: The benefits of lasers over high-speed turbine mechanical instrumentation for crown removal encompass efficient restoration recovery without damage to tooth surfaces; and a relatively easier and faster procedure without the use of anesthetic agents. Methods: The Er: YAG laser (no contact; 3.2-4.0 W, 20 Hz) was used to extract the porcelain prosthesis, followed by a gingivectomy with the Nd: YAG laser on tooth 12 to improve the gingival contour. The dental surfaces where the ceramic prosthesis will be cemented were scanned. Then, CAD / CAM technology was used to make the ceramic veneers that were cemented in the same session. Results: The efficacy the Er:YAG laser energy was observed by the decreased of the time to remove all-ceramic materials through ablation of bonding cements, reducing working time by 75% compared to a high-speed turbine. Conclusions: An Er: YAG laser can safely remove lithium disilicate crowns with the settings used in this study. Laser-assisted removal of all ceramic PDFs is a promising treatment protocol. The use of the Nd: YAG (2.0 W power, short 20Hz, 320 µm optical fiber, in contact) laser allowed gingivoplasty to be performed, automatically cauterizing avoiding post-operative bleeding, and facilitating the preparation of ceramic restorations the same day. The use of high-power lasers and the use of accompanying CAD / CAM technology allowed this clinical case to be completed in a single visit without the use of temporary restorations, achieving absolute patient satisfaction. Keywords Er:YAG; Nd:YAG; Lithium disilicate ceramic; CAD/CAM.

In Vitro Evaluation of Antimicrobial Efficacy of the Different Concentrations of Chitosan against Staphylococcus epidermidis in Disinfection of the Root Canal System

During endodontic procedures, along with mechanical instrumentation, irrigants are imperative for pathogeneradication. As the strains of pathogens are becoming antibiotic resistant at a constant ascending pace andalso the potentially harmful effect is associated with synthetic drugs, so studies on natural alternatives forirrigation are being done. Chitosan, a natural alternative, has been evaluated as an antimicrobial medicine.Recently, in cases presenting with persistent infections after endodontic treatment, it was noted that of all themicrobial species identified, the prevalence of s.epidermidis was the most. In this current study, an analysisof the antimicrobial effectiveness of chitosan as a potent root canal irrigant, for disinfecting the root canalwas conducted. Methodology: By the serial dilution method, the minimum inhibitory concentration wasdetermined. Dilution of the test solution was done using 10% DMSO solution. After which, incubationin a rotary incubator, at 180 rotations per minute, the temperature of 37?, for 24 hours was done. Forobtaining the zones of inhibition of different concentration (0.2%, 0.5%, 0.75, 1%) of chitosan irrigant, theagar diffusion method was applied and the resultant clear zone was measured with a ruler. Result: Chitosan(liquid) had promising antibacterial activity against Staphylococcus epidermidis, with a 16 mm zone ofinhibition at 100 µg/ml. Conclusion: Within the limitations of the present study, it was observed that, evenat lower concentrations, chitosan (liquid form) effectively hindered the further growth of S.epidermidis.

The Specifics of the Fiscal Mechanism Operation in the Ukrainian Lands in Cossack Times

The study of sources of filling and areas of use of the state treasury in the Cossack times becomes especially relevant, because it allows finding out whether this process was carried out in the Ukrainian lands chaotically, or had a clear order. The purpose of the study is to consider the specific features of the development and functioning of the fiscal mechanism on Ukrainian territory in the Cossack era (16th-18th centuries). The specific features of scientific tasks that are the subject of the study required the use of a set of special methods (philosophical, general, specific), the use of which helped analyse the historical aspects of the fiscal mechanism during the Zaporozhian Sich and Hetmanate. The study clarified the specific features of operation of the fiscal mechanism components, in particular the revenues and expenditures of the Cossack states. It is established that in Cossack times the revenues of the state treasury were mostly formed from tax sources, and also came from economic, judicial, military, and trade activities of the state. There were also specific revenue instruments of the fiscal mechanism, in particular “ralets”. In the Zaporizhzhya Sich, the revenues of the state treasury included monetary and material support from other states, and in the Hetmanate part of the state needs were met at the expense of state duties. In addition, separate taxes were imposed on the maintenance of the church and the clergy in the Hetmanate. The study found that in the Cossack era the expenditures of the state treasury were usually directed to the maintenance of the Cossack (Hetman's) administration, provision of military needs and financing of the church. With the increasing military and political pressure of the neighboring Polish and Russian states, the fiscal mechanism of the Cossack states lost its independence and acquired the characteristics of the invading states. The practical value of the study is that the historical analysis covered the basic principles of the fiscal mechanism in Cossack times, the elements of which can be introduced in modern conditions

Effect of three Mechanical Systems on Removal of Endotoxins from Asymptomatic Necrotic teeth with apical Periodontitis. (A randomized clinical trial)

Objective: The present study's objective was to evaluate the percentage of endotoxin diminution after mechanical instrumentation of asymptomatic necrotic teeth with apical periodontitis using three mechanical systems. Materials and Methods: One hundred and eighty patients between 18 and 65 participated in this research. Thirty-five of 140 teeth were selected for the four enlargement techniques. Control group, TFA, WOG, and PTN groups received final flushing with 6oC 17% EDTA solution gently administered to the WL through a cold (6oC) sterile metallic micro-cannula attached to the Endovac system (Kerr Endo) for one minute. Two samples of the canal were obtained using a sterile paper cone (size 30) introduced into the canal´s full length. Results: Results showed a statistically significant difference between the two groups in the percentage reduction of endotoxin levels (P-value &lt;0.001, Effect size = 0.598). Group PTN showed a statistically significantly lower median % reduction in endotoxin quantities than Group WOG and TFA. Conclusion: Under this study's conditions, it can be concluded that the PTN system was more effective in endotoxins reduction in teeth with necrotic pulps. When the RCT is correctly instrumented, single visit RCT can be as effective as a multiple visit treatment.

Evaluation of antibacterial efficiency of root canal disinfection by using Qmix an irrigating solution in root canal system &amp;#40;an in-vitro study&amp;#41;

Background : The major cause of pulpal and periapical diseases are living and non living irritants. The living irritants include various microorganisms including bacteria, yeast and viruses. The success of endondotic treatment depends on eradication of these microorganisms and prevention of reinfection. Mechanical instrumentation alone does not result in microorganism free root canal system, due to complex root canal anatomy. Thus, irrigants are essential to ensure microbial minimization and elimination of organic tissue remnants. Qmix irrigating solution used as a final rinse after bleach for one step smear layer removal and disinfection and eliminate greater than 99.99% of planktonic bacteria including the resistant species E.faecalis. Objective: The aim of this invitro study is to evaluate the antimicrobial efficacy of qmix irrigant in infected root canal system. Material and Methods: Crowns of 60 extracted premolar teeth were sectioned at the cemento-enamel junction. The samples were stored temporarily in physiological saline solution. The canals were shaped using crown down technique upto F3 protaper file. Enterococcus faecalis was inoculated on Brain heart infusion (BHI) agar plate and incubated anaerobically at 37 ?C for 24 h. After incubation, the specimens were removed and then rinsed. In the negative group (n=20), there was no treatment. In the other group (n=20), the sections were irrigated with 5 mL of 5.25% NaOCl for 60 s. The third group (n=20) is treated with Qmix solution for 60-90 seconds. After the disinfection procedures, samples were subjected to CFUcounting evaluations. Results: After irrigation, the elimination of bacteria and the smear layer in the positive group were significantly superior, compared with the negative group (p Conclusion: Both irrigating solution groups, especially the Qmix group, showed satisfactory bactericidal effects in experimentally contaminated root canals. Keywords: Qmix, E.faecalis.

Can Probiotics Emerge as Effective Therapeutic Agents in Apical Periodontitis? A Review

Apical periodontitis (AP) is a biofilm-associated disease initiated by the invasion of dental pulp by microorganisms from the oral cavity. Eradication of intracanal microbial infection is an important goal of endodontic treatment, and this is typically accomplished by mechanical instrumentation and application of sodium hypochlorite and chlorhexidine. However, these agents are tissue-irritating at higher concentrations and cytotoxic. Certain probiotics have been found effective in controlling marginal periodontitis, as evidenced by reduction of pathogenic bacterial loads, gains in clinical attachment levels, and reduced bleeding on probing. In vitro studies have shown inhibitory activity of some probiotics against endodontic pathogens. Similarly, in vivo studies in rats have demonstrated a positive immuno-modulatory role of probiotics in AP, as manifested by decreased levels of proinflammatory markers and increased levels of anti-inflammatory markers. A role for probiotics in effecting a reduction of bone resorption has also been reported. This review provides an outline of current research into the probiotic management of AP, with a focus on understanding the mechanisms of their direct antagonistic activity against target pathogens and of their beneficial modulation of the immune system.

Coupled dynamic modeling of piezo-actuated compliant mechanisms subjected to external loads

Piezoelectrically actuated compliant mechanisms are key techniques in designing micro/nano manipulators, precision positioning stages/grippers and many other mechanical instruments. By considering the coupling relationship among piezoelectric actuator, compliant mechanisms and their external loads, a new modeling methodology in Laplace domain is proposed to capture the coupling dynamic characteristics of such a complex system. The coupled dynamic model of piezo-actuated compliant mechanisms subjected to mass-spring-damper loads with an accessorial force is analytically derived in the form of transfer function based on the concept of two-port dynamic stiffness model and control theory. The coupled dynamic model is further transformed into a generalized control block diagram in a unified form. As an application case, the static and dynamic performances of a typical flexure-based precision manipulator actuated by amplified piezoelectric stacks are analyzed with the presented model. It is demonstrated, both numerically and experimentally, that the proposed approach is accurate and straightforward for solving the coupled dynamic modeling issue in piezo-actuated compliant mechanisms subjected to external loads, and would be general enough for a wide class of applications involving multi-domain dynamic problems.

Mechanical instruments and everyday life: the player piano in Portugal

AbstractThis paper examines player pianos in Portugal between the 1890s and the 1930s. In a small European country with few production facilities, mechanical music developed in a particular way since a local recording industry was expanding rapidly and radio was not yet disseminated. Despite the local market's reliance on imported goods, the music business concentrated on Portuguese pieces. The mechanisation of the piano and its display as a product that embodied modernity illustrates the transformations that took place in Portugal at the beginning of the 20th century. These were reflected in new forms of entertainment, such as cinemas and nightclubs that incorporated new music genres. At the dawn of the century, the leisure market relied on the popular music theatre, which was dominated by Portuguese, French and Spanish music. In the interwar period, English and American pieces made their way into people's lives, transforming the music business.

Development of Monitoring and Control Systems in Cavity Cooling System Test Loop for The Experimental Power Reactor

The Experimental Power Reactor as a fourth type of reactor currently being developed in Indonesia is high temperature gas cooled reactor which has a passive cooling system. This passive cooling system uses the principle of natural circulation through changes in water density and called as reactor cavity cooling system. To study the reactor cavity cooling system, a test facility will be created at BATAN which is called the Cavity Cooling Test Loop. This test facility consists of mechanical systems, piping and instrumentation. The instrumentation are includes temperature measurement, flow rate, pressure and heating control. Measurement and control monitoring systems that are needed in order to get data effectively and efficiently have not been made. Therefore, in this study, LabVIEW was used to create monitoring and control programs. A program to monitor temperature, flow rate and pressure has been made with a measurement point of 60 thermocouples, 1 flowmeter, and 1 pressure sensor. The heaters control program is made for 10 units with control of each heater ranging from 200°C to 900°C. Simulation has been done to test the performance of the program using DAQ simulator. Based on the simulation results, the program can be applied to the test facility by paying attention to the input type in the DAQ module.