A model for determining the time of pointing a grip-cutting device of feller buncher machines on a growing tree

Исследование посвящено нахождению аналитической математической модели по определению времени наведения захватно-срезающего устройства на растущее дерево. В качестве известных параметров используются конструктивные размеры технологического оборудования, снятые с компоновочно-кинематических схем валочно-пакетирующих машин, требуемая высота пня и среднее расстояние между деревьями пасики. Поиск требуемой модели кратко можно разделить на несколько последовательных этапов: нахождение пути, который пройдет шток гидроцилиндра привода стрелы, и по известной формуле скорости перемещения поршня гидроцилиндра находится время на подвод стрелы к дереву; нахождение пути, который пройдет шток гидроцилиндра привода рукояти; нахождение пути, который пройдет шток гидроцилиндра привода наклона захватно-срезающего устройства; нахождение пути, который пройдет шток гидроцилиндра привода рычагов захвата в процессе раскрытия. Сумма времени на подвод каждого из элементов технологического оборудования и есть время на наведение, присущее неопытному оператору, в случае опытного оператора время на наведение захватно-срезающего устройства к дереву определяется максимальным временем одного из компонентов. The research is devoted to finding an analytical mathematical model for determining the aiming time of a feller head on a growing tree. As the known parameters are used. The design dimensions of the technological equipment, taken from layout and kinematic diagrams of feller-buncher machines, the required stump height and the average distance between the trees of the windrow. The search for the required model can be briefly divided into several successive steps: finding the path that the hydraulic cylinder rod of the boom drive will take and by the known formula of speed of movement of the hydraulic cylinder piston is time to bring the boom to the tree; finding the way which the rod of the hydraulic cylinder of the arm drive; to find the path which the hydraulic cylinder rod of the tilt of the feller head; finding the path which the hydraulic cylinder rod for the arm actuator will take during the opening. The sum of the time for supplying each of the elements of technological equipment is the time required for the orientation, which is characteristic for a nonexperienced operator. In case of an experienced operator the time for setting the feller head to the tree is determined by the maximum time of one of the components.

Trueness of Intraoral Scanners in Implant-Supported Rehabilitations: An In Vitro Analysis on the Effect of Operators’ Experience and Implant Number

(1) Background: Intraoral scanners (IOS) are widely used in prosthodontics. However, a good trueness is mandatory to achieve optimal clinical results. The aim of the present in vitro study was to compare two IOS considering the operator’s experience and different implant clinical scenarios. (2) Methods: Two IOS (IT—Itero, Align Technology; and OS—Opera MC, Opera System, Monaco) were compared simulating three different clinical scenarios: single implant, two implants, and full-arch rehabilitation. Ten scans were taken for each configuration by two different operators (one expert, one inexperienced); influence of operator experience and the type of scanner used was investigated. (3) Results: Trueness of the scans differed between the experienced and non-experienced operator and this difference was statistically significant in all the three scenarios (p = 0.000–0.001, 0.037). A significant difference was present between the scanners (p = 0.000), in the two-implant and full-arch scenarios (p = 0.00). (4) Conclusions: Experience of the operator significantly affect trueness of IT and OP scanners. A statistically significant difference was present among IOS in the two-implant and full-arch scenarios.

Reciproc Blue x V-File: a study on the performance of two reciprocant instruments after third use

Objective: The cleaning and shaping of root canals is undeniably a step of great importance for the success of endodontic treatment. With the aim of optimizing the time and quality of this step, numerous instruments of different materials and shapes have been developed over the years. One of these instruments was nickel-titanium files, which have greater flexibility and resistance, allowing a better prognosis for endodontic treatment. In this study, two endodontic files, Reciproc Blue and V-File, were compared with the aim of evaluating their performance after the third use. Materials and methods: 60 acrylic blocks wrapped with laminated paper and filled with Nankin ink were used. Instrumentation was performed with an endodontic engine, by an experienced operator. After instrumentation, the blocks were photographed so that the photographs were superimposed. Results: After statistical analysis, it was found that there was no significant difference in the performance of the two groups after the third use. Conclusion: There was no significant difference between the two studied groups, and both are safe for the preparation of curved canals, but it is necessary that the manufacturer's recommendation is followed, regarding the number of canals instrumented with the same file.

The Effects of Magnification and Operator’s Experience on the Quality of Preclinical Dental Procedures

Aims: This study evaluated the effect of magnification on the quality of preclinical class I cavity preparations according to operator’s experience. Methodology: This was an experimental laboratory study. The response variable was the quality of Class I cavity preparations evaluated by the Class I Cavity Preparation Assessment - COCA. Class I cavity preparations were performed in all artificial first molars under four conditions: unaided visualization, using a simple loupe, using a Galilean loupe, and using a Keplerian loupe (N=640). The two-factor analysis of variance was performed (α=0.05). Results: No interactions between operator’s experience and magnification device were found (p>0.05). Although, higher quality scores were given to cavity preparations in tooth #36 using the Galilean loupe compared to naked eye (p<0.01). The more experienced operator received higher quality scores for tooth #46 regardless of the magnification system used (µexperienced=7.0±2.3 and µinexperienced=5.4±2.4). Conclusion: The use of magnification devices did not influence the quality of class I cavity preparations performed on tooth #16, 26, 46. Galilean loupe was associated with improved quality of the cavity preparation performed on tooth #36, and the operator’s experience influenced the quality of the preparation on tooth #46.

Comparison of Distal Radial, Proximal Radial, and Femoral Access in Patients with ST-Elevation Myocardial Infarction

Recent studies have indicated that distal radial access (DRA) is feasible in patients undergoing percutaneous coronary intervention (PCI). The present study aimed to compare DRA, proximal radial access (PRA), and femoral access (FA) in patients with ST-elevation myocardial infarction (STEMI) undergoing PCI. Data were analyzed for 109 patients with STEMI treated via primary PCI from March 2020 to May 2021. The success rate of DRA was 83.3% (35/42), including seven cases of failed puncture (puncture failure = 5, severe radial artery spasm = 2). Primary PCI via the DRA was successful in all 35 patients. After classifying the patients requiring crossover into a separate group, the percentage of the puncture time in the door-to-wiring time was 2.7% [2.2–4.3], 3.3% [2.3–4.0], 2.6% [1.2–4.9], and 27.0% [13.5–29.3] in the DRA (n = 35), PRA (n = 24), FA (n = 26), and crossover (n = 9) groups, respectively (p < 0.01). Only two local hematomas (≤5 cm) occurred in the DRA group, while one patient in the FA group required surgical treatment and a transfusion for an access-site vascular injury. When performed by an experienced operator, DRA may represent a feasible alternative to other access routes in select patients with STEMI undergoing PCI, such as those with a high risk of bleeding.

INAF Online Lab: can hands-on, educational laboratories be online?

&lt;p&gt;&lt;strong&gt;INAF &lt;em&gt;Online Lab&lt;/em&gt;&lt;/strong&gt; is the name of the project born within EduINAF (the online magazine of the Italian Institute of Astrophysics) during the Covid-19 pandemic and the subsequent rearrangement of the outreach and teaching activities normally carried out in person. These online laboratories are an example of how to virtually take by the hand those same young people with whom only a year ago it was possible, and indeed natural, to interact live. From their schools or homes, the students are guided through the activity by an experienced operator, and take on the role of astronomers while building, observing, learning and wondering about the great mysteries of space. The four online laboratories currently active have been optimized to be perfectly usable during science festivals in an interactive way and at practically no cost.&lt;/p&gt; &lt;p&gt;Throughout the presentation, we will describe the project and its possible applications and evolutions, with some examples to be shown to the audience.&lt;/p&gt;

3D Segmentation of Perivascular Spaces on T1-Weighted 3 Tesla MR Images With a Convolutional Autoencoder and a U-Shaped Neural Network

We implemented a deep learning (DL) algorithm for the 3-dimensional segmentation of perivascular spaces (PVSs) in deep white matter (DWM) and basal ganglia (BG). This algorithm is based on an autoencoder and a U-shaped network (U-net), and was trained and tested using T1-weighted magnetic resonance imaging (MRI) data from a large database of 1,832 healthy young adults. An important feature of this approach is the ability to learn from relatively sparse data, which gives the present algorithm a major advantage over other DL algorithms. Here, we trained the algorithm with 40 T1-weighted MRI datasets in which all “visible” PVSs were manually annotated by an experienced operator. After learning, performance was assessed using another set of 10 MRI scans from the same database in which PVSs were also traced by the same operator and were checked by consensus with another experienced operator. The Sorensen-Dice coefficients for PVS voxel detection in DWM (resp. BG) were 0.51 (resp. 0.66), and 0.64 (resp. 0.71) for PVS cluster detection (volume threshold of 0.5 within a range of 0 to 1). Dice values above 0.90 could be reached for detecting PVSs larger than 10 mm3 and 0.95 for PVSs larger than 15 mm3. We then applied the trained algorithm to the rest of the database (1,782 individuals). The individual PVS load provided by the algorithm showed a high agreement with a semi-quantitative visual rating done by an independent expert rater, both for DWM and for BG. Finally, we applied the trained algorithm to an age-matched sample from another MRI database acquired using a different scanner. We obtained a very similar distribution of PVS load, demonstrating the interoperability of this algorithm.

Lateral Abdominal Muscles Shear Modulus and Thickness Measurements under Controlled Ultrasound Probe Compression by External Force Sensor: A Comparison and Reliability Study

The aim of this study was to perform a reliability and agreement analysis and to compare lateral abdominal muscles (LAMs) thickness and elasticity results obtained by an experienced operator, by a non-experienced operator, and in an ultrasound imaging probe compression controlled (PCC) condition with minimal force necessary to obtain a proper ultrasound image. The sample consisted of 39 adolescents. An Aixplorer ultrasound scanner was used to evaluate the LAM. The probe in PCC condition was positioned in a prepared probe holder coupled with a pressure sensor. The LAM thickness and elasticity measurements were significantly (p < 0.05) different in the ultrasound PCC condition, compared to results obtained by both examiners. The abdominal oblique external and internal muscle thickness measurements were underestimated and all LAM shear moduli were overestimated during measurements without controlling the probe compression by an external sensor. The intra-class correlation coefficient was excellent in all conditions, but the smallest detectable differences were approximately 43–60% lower during the measurements collected in PCC condition. Differences in LAM measurements between PCC and ‘on-hand’ conditions may be clinically irrelevant when the force applied by the probe is consciously controlled by the examiner. However, during ultrasound measurements of the LAM morphology, the potential under/over estimation should always be considered when measurements are performed without controlling probe compression by an external sensor.

DESCRIPTION OF PRE AND POST HEMOGLOBIN CONDITIONS OF CAESAREAN SECTION

Background: Cesarean delivery without any indication of an increase should the procedure be safer but there is still an increased risk for pregnant women who have a cesarean birth, which is bleeding. Research Objective: To find out the description of hemoglobin levels pre and post cesarean delivery at the Mother and Child Hospital Dian Pertiwi Karanganyar Regency.Research Methods: This research is secondary data research taken from medical record installations at Dian Pertiwi Mother and Child Hospital in Karanganyar Regency.Results: Of 82 samples of pregnant women who gave birth by cesarean at the Mother and Child Hospital Dian Pertiwi Karanganyar 44 (60%) with normal hemoglobin levels above 12 gr / dl pre-cesarean section and 38 (40%) with hemoglobin levels 11 gr / dl post cesarean section.Conclusion: Samples of pregnant women who gave birth by cesarean and there was no history of anemia before cesarean section, after cesarean section decreased hemoglobin levels 2.1 gr / dl. The decrease in hemoglobin level is also supported by the management carried out by a very experienced operator, according to the procedure that makes a decrease in hemoglobin levels is not much.

Rapid Truck Loading for Efficient Feedstock Logistics

A multi-bale handling unit offers an advantage for the efficient hauling of round bales. Two empty racks on trailers are left at a satellite storage location for loading while a truck tractor delivers two loaded racks to the biorefinery, thus uncoupling the loading and hauling operations and increasing the efficiency of both. The projected 10 min trailer exchange time equals the projected 10 min unload time at the biorefinery achieved by lifting off the two full racks and replacing them with two empties, a technology adapted from the container shipping industry. A concept is presented for a bale loader that latches onto the rack/trailer and loads bales into the bottom tier chambers. This machine will load 10 bales into the rack on the front trailer by attaching on to the front of the trailer and 10 bales into the rear trailer by attaching onto the rear. A telehandler removes bales from single-layer storage and places them in the bale loader to load the bottom tier compartments. The top tier compartments are loaded directly from the top. Expectations are that an experienced operator can average 9 loads in a 10 h workday, and load-out cost is estimated as 3.61 USD/Mg, assuming the average achieved load-out productivity over annual operation is 60% of optimum productivity (24 Mg/h) equal to 14.4 Mg/h. Cost increases to 4.81 USD/Mg when the productivity factor drops to 45%, and cost is 3.09 USD/Mg for a factor of 70%.