Levels Of Compressive Force Research Articles

Machine learning modeling for ultrasonic quality attribute assessment of pharmaceutical tablets for continuous manufacturing and real-time release testing

In in-process quality monitoring for Continuous Manufacturing (CM) and Critical Quality Attributes (CQA) assessment for Real-time Release (RTR) testing, ultrasonic characterization is a critical technology for its direct, non-invasive, rapid, and cost-effective nature. In quality evaluation with ultrasound, relating a pharmaceutical tablet’s ultrasonic response to its defect state and quality parameters is essential. However, ultrasonic CQA characterization requires a robust mathematical model, which cannot be obtained with traditional first principles-based modeling approaches. Machine Learning (ML) using experimental data is emerging as a critical analytical tool for overcoming such modeling challenges. In this work, a novel Deep Neural Network-based ML-driven Non-Destructive Evaluation (ML-NDE) modeling framework is developed, and its effectiveness for extracting and predicting three CQAs, namely defect states, compression force levels, and amounts of disintegrant, is demonstrated. Using a robotic tablet handling experimental rig, each attribute’s distinct waveform dataset was acquired and utilized for training, validating, and testing the respective ML models. This study details an advanced algorithmic quality assessment framework for pharmaceutical CM in which automated RTR testing is expected to be critical in developing cost-effective in-process real-time monitoring systems. The presented ML-NDE approach has demonstrated its effectiveness through evaluations with separate (unused) test datasets.

Investigating the Impact of UV-C Radiation on the Mechanical Characteristics of Semifinished Potato Tubers Prepared from Varied Potato Cultivars

The relationship between various characteristics of postharvest vegetables and their corresponding biological surface properties is strongly interconnected, leading to a broad spectrum of properties after irradiation. The primary objective of the present study was to investigate how different doses of Ultraviolet-C (UV-C) radiation affect the mechanical properties of semifinished potato tubers derived from distinct Polish varieties, namely, Innovator, Fineziya, and Victoria. A low UV-C dose ranging from 0 to 30 mJ/cm2 was administered. The Innovator variety, when subjected to irradiation, exhibited the highest levels of compression force, cutting force, and bending force. Additionally, the irradiated samples demonstrated improved resistance to compression force, bending force, and increased weight compared to the control samples. Conversely, the control samples exhibited higher resistance to cutting load than the irradiated ones in all varieties. The analysis of variance confirmed a significant difference in compression, cutting force, and tuber weight among the treatment samples in all varieties. Furthermore, stress-strain analyses were performed and showed an elastic behavior of the Victoria variety and a higher Young’s modulus for the Innovator variety.

The effect of thoracic dimensions on compression depth during cardiopulmonary resuscitation.

The effect of the dimensions of the thoracic cage on the resuscitation outcome of cardiopulmonary resuscitation (CPR) maneuvers has long been debated. In this study, the effect of changes in the rib cage dimensions on the achieved compression depth was investigated using finite element simulations. A total of 216 different rib cage geometry models were considered and, in each case, the result of applying different levels of compression force up to 600 N were simulated. The Haller Index of the rib cage is defined as the ratio of the transverse diameter and the antero-posterior diameter. Our results suggest that, with a fixed level of compression force, performing CPR on rib cages having a low Haller Index and/or a larger height leads to compression depths below the average. Alternatively, if a target compression depth is set for CPR, in general a lower compression force would be required for individuals with higher Haller Index and/or lower chest height. In addition, present results indicate that wider chested individuals will experience lower stress levels on their ribs to achieve the required CPR target depth. Moreover, in the present study we propose predictive models, based on anthropometric parameters, for compression depth and rib stress during chest compressions. In particular, the model suggests that in future correlations of empirical CPR data the patients' Haller index and vertical (sagittal) cross-area are the best parameters to be used as independent variables in a fit.

Effect of binder, lubricant and compression force levels on hardness and disintegration time of immediate release tablets with a high-dose API - a 33 full-factorial design

Effect of binder, lubricant and compression force levels on hardness and disintegration time of immediate release tablets with a high-dose API - a 33 full-factorial design

Influence of Crack Width in Alternating Tension–Compression Regimes on Crack-Bridging Behaviour and Degradation of PVA Microfibres Embedded in Cement-Based Matrix

The use of high-performance polymeric microfibres in enhancing the ductility of cementitious composites is widespread. A vivid example is the application of strain-hardening cement-based composites (SHCCs) in the construction industry. However, there are a few challenges which need to be addressed with respect to material design. For instance, the ductility of SHCC diminishes under alternating tension–compression loading, where the fibres lose their crack-bridging capacity due to specific damage mechanisms. The damage development and its influence on crack-bridging capacity have been studied in previous works by the authors. The paper at hand focuses on the influence of crack width on the crack-bridging capacity of polymeric microfibres in conjunction with the number of cycles in an alternating tension–compression regime with different cyclic compressive force levels. It shows that bridging capacity can be markedly influenced by crack width: an increase in crack width leads to more severe damage to the fibres and thus to lower crack-bridging capacity. Then, after analysing the specimens by means of electron microscopy, a hypothesis is presented to address the effect of crack width on damage development. Finally, a simple approach is proposed for estimating the influence of different parameters on fibre degradation.

Forces in the Distal Radius During a Pushup or Active Wrist Motions.

To determine the 6 degrees of freedom forces and moments in the distal radius that occur during a pushup or other active wrist motions. Eight fresh-frozen cadaveric wrists were moved through 6 physiological motions and held at 1 static pushup position while the force through the distal radius was measured with a 6 degrees of freedom load cell. Three levels of compressive force were applied at the pushup position. Active wrist motions caused axial forces up to 283 N and moments up to 0.7 N-m. Those motions with a smaller range had significantly smaller axial forces than the larger flexion-extension or dart-thrower's motions. With an 89-N pushup force applied, the average maximum axial force was 69 N, the radially directed force was 12 N, and the moment about the radioulnar axis was 2.3 N-m. Linear extrapolation of the forces to 100% body weight indicate that the axial force going through the distal radius would be 663 N, the radial force would be 147 N, and the moment about the radioulnar axis would be 18.6 N-m. Large distal radius forces and moments can occur during pushup and active wrist motions. There are not only large axial compressive forces but also nontrivial radially directed forces. This study may help surgeons and therapists better treat complicated distal radius fractures as well as provide for better comparisons of existing or new distal radius plates and constructs that are designed to treat these complicated loading patterns.

Can Breast Compression Be Reduced in Digital Mammography and Breast Tomosynthesis?

The objective of this study was to investigate the impact of decreasing breast compression during digital mammography and breast tomosynthesis (DBT) on perceived pain and image quality. In this two-part study, two groups of women with prior mammograms were recruited. In part 1, subjects were positioned for craniocaudal (CC) and mediolateral oblique (MLO) views, and four levels of compression force were applied to evaluate changes in breast thickness, perceived pain, and relative tissue coverage. No imaging was performed. In part 2, two MLO DBT images of one breast of each patient were acquired at standard and reduced compression. Blurring artifacts and tissue coverage were judged by three breast imaging radiologists, and compression force, breast thickness, relative tissue coverage, and perceived pain were recorded. Only the first reduction in force was feasible because further reduction resulted in inadequate breast immobilization. Mean force reductions of 48% and 47% for the CC and MLO views, respectively, resulted in a significantly reduced perceived pain level, whereas the thickness of the compressed breast increased by 0.02 cm (CC view) and 0.09 (MLO view, part 1 of the study) and 0.38 cm (MLO view, part 2 of the study), respectively, with no change in tissue coverage or increase in motion blurring. Mammography and DBT acquisitions may be possible using half of the compression force used currently, with a significant and substantial reduction in perceived pain with no clinically significant change in breast thickness and tissue coverage.

Bipolar Electrosurgical Vessel-Sealing Device With Compressive Force Monitoring

Bipolar electrosurgical vessel sealing is commonly used in surgery to perform hemostasis. The electrode compressive force is demonstrably an important factor affecting the vessel seal burst pressure, an index of the seal quality. Using a piezoresistive force sensor attached to the handle of a laparoscopic surgical device, applied handle force was measured and used to predict the electrosurgical vessel compressive force and the pressure at the electrode. The sensor enables the monitoring of vessel compressive force during surgery. Four levels of compressive force were applied to seal three types of porcine vessels (carotid artery, femoral artery, and jugular vein). The burst pressure of the vessel seal was tested to evaluate the seal quality. Compressive pressure was found to be a statistically significant factor affecting burst pressure for femoral arteries and jugular veins. Vessels sealed with low compressive pressure (<300 kPa) have a higher failure rate (burst pressure<100 mm Hg) than vessels sealed with high compressive pressure. An adequate compressive force is required to generate the compressive pressure needed to form a seal with high burst pressure. A laparoscopic surgical device with compressive force monitoring capability can help ensure adequate compressive pressure, vessel burst pressure, and quality of seal.

Does an increase in compression force really improve visual image quality in mammography? – An initial investigation

ObjectiveLiterature speculates that visual image quality (IQ) and compression force levels may be directly related. This small study investigates whether a relationship exists between compression force levels and visual IQ. MethodTo investigate how visual IQ varies with different levels of compression force, 39 clients were selected over a 6 year screening period that had received markedly different amounts of compression force on each of their three sequential screens. Images for the 3 screening episodes for all women were scored visually using 3 different IQ scales. ResultsCorrelation coefficients between the 3 IQ scales were positive and high (0.82, 0.9 and 0.85). For the scales, the IQ scores their correlation does not vary significantly, even though different compression levels had been applied. Kappa IQ scale 1: 0.92, 0.89, 0.89. ANOVA IQ scale 2: p = 0.98, p = 0.55, p = 0.56. ICC IQ scale 3: 0.97, 0.93, 0.91. ConclusionFor the 39 clients there is no difference in visual IQ when different amounts of compression are applied. We believe that further work should be conducted into compression force and image quality as ‘higher levels’ of compression force may not be justified in the attainment of suitable visual image quality.

Comparison of headless screws used in the treatment of proximal nonunion of scaphoid bone

Screws with different levels of compression force are available for scaphoid fixation and it is known that the Acutrak screw generates greater compression than the Herbert screw. We retrospectively compared two types of headless compression screw for their effectiveness in the repair of scaphoid nonunion. Twenty-nine cases of proximal scaphoid nonunion were surgically treated with non-vascularised bone graft: the Acutrak screw was used in 17 patients and the cannulated Herbert screw in 12 patients. Wrist range of motion, Mayo wrist score, grip strength and QuickDASH scores were indicators used for the functional evaluation. Radiographic findings were assessed for consolidation of nonunion and signs of arthrosis. The mean follow-up time was 49.2 months (range 12-96). Statistically, there was no significant difference between the Acutrak and Herbert screw types in terms of functional evaluation and time required for consolidation. Greater compression did not influence the functional outcome, consolidation rate or time to consolidation. The need for greater compression in the treatment of proximal scaphoid nonunions is thus questionable because it may increase the risk of proximal fragment communition.

Investigation of Material Fatigue Behavior Through Cyclic Ball Indentation Testing

Abstract An experimental investigation of cyclic indentation testing to characterize the fatigue response of three different metallic materials: two aluminum alloys (2014-T651 and 7175-T7351) and a duplex stainless steel (2205), was carried out. The force-displacement response during cyclic loading was logged continuously throughout the entire duration of the test and the data were analyzed to identify parameters such as change in total depth of penetration, change in loading and unloading slopes, change in unloading intercept as a function of number of cycles, and change in displacement range as a function of number of cycles. From the results, one could identify the transient response of the material during cyclic loading, and identify some specific points relating to fatigue failure life, such as knee-point response in depth of penetration as a function of number of cycles of loading. It was observed that data on unloading slope plotted as a function of number of cycles also provide an indication of specimen failure in compression-compression fatigue. The responses were found to be similar for all the three materials tested at different maximum compressive force levels. Failure life data in the low cycle fatigue (LCF) region was evaluated for Al-Cu-Mg alloy 7175-T7351 and the data compared with the failure indicators (knee point) during cyclic indentation testing. A reasonable correlation was established between failure life, as indicated by LCF testing and knee point indicated by cyclic indentation. Experiments were also carried out on virgin material of 7175-T7351 alloy and plastically deformed material of the same alloy. Both static and cyclic indentation tests show a difference in material behavior before and after residual plastic deformation. Further work is required to correlate failure life data as obtained from cyclic indentation with specimens having controlled damage levels, before this technique can be used for residual life estimation purposes.

Development of a method for the determination of caffeine anhydrate in various designed intact tables by near-infrared spectroscopy: A comparison between reflectance and transmittance technique

Using near-infrared (NIR) spectroscopy, an assay method which is not affected by such elements of tablet design as thickness, shape, embossing and scored line was developed. Tablets containing caffeine anhydrate were prepared by direct compression at various compression force levels using different shaped punches. NIR spectra were obtained from these intact tablets using the reflectance and transmittance techniques. A reference assay was performed by high-performance liquid chromatography (HPLC). Calibration models were generated by the partial least-squares (PLS) regression. Changes in the tablet thickness, shape, embossing and scored line caused NIR spectral changes in different ways, depending on the technique used. As a result, noticeable errors in drug content prediction occurred using calibration models generated according to the conventional method. On the other hand, when the various tablet design elements which caused the NIR spectral changes were included in the model, the prediction of the drug content in the tablets was scarcely affected by those elements when using either of the techniques. A comparison of these techniques resulted in higher predictability under the tablet design variations using the transmittance technique with preferable linearity and accuracy. This is probably attributed to the transmittance spectra which sensitively reflect the differences in tablet thickness or shape as a result of obtaining information inside the tablets.

Evaluation and Validation of a Fully Instrumented Hüttlin HKC 05-TJ Laboratory-Scale Fluidized Bed Granulator

The instrumentation and validation of a laboratory-scale fluidized bed apparatus is described. For continuous control of the process, the apparatus is instrumented with sensors for temperature, relative humidity (RH), and air velocity. Conditions of inlet air, fluidizing air, product, and exhaust air were determined. The temperature sensors were calibrated at temperatures of 0.0°C and 99.9°C. The calibration of the humidity sensors covered the range from 12% RH to 98% RH using saturated electrolyte solutions. The calibration of the anemometer took place in a wind tunnel at defined air velocities. The calibrations led to satisfying results concerning sensitivity and precision. To evaluate the reproducibility of the process, 15 granules were prepared under identical conditions. The influence of the type of pump used for delivering the granulating liquid was investigated. Particle size distribution, bulk density, and tapped density were determined. Granules were tableted on a rotary press at four different compression force levels, followed by determination of tablet properties such as weight, crushing strength, and disintegration time. The apparatus was found to produce granules with good reproducibility concerning the granule and tablet properties.

Compression force/time-profiles of microcrystalline cellulose, dicalcium phosphate dihydrate and their binary mixtures—a critical consideration of experimental parameters

Compression force/time-profiles of microcrystalline cellulose and dicalcium phosphate dihydrate and mixtures thereof were compared on a modern rotary press by three different methods of compression: compression to a constant tablet weight, compression to a constant tablet height and compression from a constant filling depth. Compression was carried out at three different compression force levels. The differences obtained by analysing the area under the curve in the compression, dwell and decompression phase could be explained by differences of the in-die working density of the powders and their respective compression behaviour. From data of the compression phase as well as from the area-quotient-index obtained from the dwell time it was possible to estimate the percolation threshold of dicalcium phosphate dihydrate in a mixture with microcrystalline cellulose to ~ 50% (w/w) corresponding to 30% (v/v).

Evaluation of debonding characteristics of a new collapsible ceramic bracket

A new collapsible ceramic bracket designed with a metal-lined arch wire slot has been recently introduced. The bracket also incorporates a vertical slot designed to help create a consistent bracket failure mode during debonding. The new bracket is thought to combine the esthetic advantages of ceramics and the functional advantages of debonding metal brackets. The purpose of this study was to compare (1) the shear bond strength of the new collapsible bracket with a traditional ceramic bracket, (2) the compressive force required to debond the new bracket from the enamel surface with that needed to debond a traditional metal bracket, and (3) the bond failure location when debonding the new bracket and a traditional ceramic bracket when pliers are used. Sixty-one Clarity collapsible ceramic brackets, 41 Transcend 6000 brackets, and 21 Victory Series metal brackets were bonded to the teeth with the same bonding system. The Zwick Universal Test Machine was used to determine the shear bond strength of 21 teeth bonded with the new bracket and 20 teeth bonded with the Transcend brackets. The same testing device was used to determine the compression force levels needed to debond 20 collapsible brackets and 21 metal brackets. Pliers were used to debond both the new ceramic brackets and Transcend brackets to determine the mode of bond failure. After debonding, all teeth and brackets were examined under 10× magnification. Any adhesive remaining after bracket removal was assessed according to the Adhesive Remnant Index (ARI). The findings indicated that the shear bond strength of the new Clarity ceramic bracket was comparable to that of a conventional ceramic bracket. Similarly, there were no significant differences in the results of the compression tests comparing the magnitude of forces needed to deform and debond both the new ceramic and metal brackets. The ARI scores for both the shear and compression tests indicated a similar bond failure pattern when the new collapsible brackets were compared with either the conventional ceramic or metal brackets. On the other hand, the χ2 test results indicated that, when debonding pliers were used, there was a significantly greater incidence of an ARI score of 1 with the collapsible brackets. This indicated that, when debonding the new brackets with the Weingart pliers, there was a greater tendency for most of the adhesive to remain on the enamel surface. In conclusion, the main advantage of the Clarity ceramic brackets is that they can be debonded in the same manner as metal brackets. When the new ceramic brackets are debonded with the Weingart pliers, most of the residual adhesive remained on the enamel surface, a pattern that is similar to the one observed with metal brackets. The failure at the bracket-adhesive interface decreases the probability of enamel damage but necessitates the removal of more residual adhesive after debonding. (Am J Orthod Dentofac Orthop 1997;112:552-9.)

Optimization-Based Biomechanical Evaluation of Isometric Exertions on a Brake Wheel

A static three-dimensional low-back biomechanical model was developed to estimate the levels of compressive force on the L3/L4 spinal joint during an experiment that simulated wheel turning. We recorded three-dimensional body posture and the resultant forces at the hands for analysis by the model. The model employed a standard link analysis procedure to resolve the external forces acting on the body to a resultant moment about L3/L4. The model then implemented an optimization algorithm to estimate the internal lumbar muscle forces generated to resist the external forces. The muscle forces and external forces were added to arrive at a prediction of compressive force at L3/L4. The experiment investigated the effects of general body posture, left hand grip, gender, and hand brake torque level upon predicted compressive force at L3/L4. A repeated measures analysis of variance (ANOVA) revealed all but one main effect and some interaction effects to be significant at p&lt;0.05. Average predicted L3/L4 compressive forces at maximum wheel torque levels ranged from 1644N for females to 6926N for large males.

Mammographic unit compression force: acceptance test and quality control protocols.

Firm compression of the breast in screen-film mammography procedures lowers the radiation dose to patients, enhances image contrast and definition, and improves visibility of pathologic conditions. Most mammography unit compression systems have no force-level indicator. Some systems show force variations with time and others, with angle and region of the compression device. Still other systems give poorly reproducible compression-force levels, and in one unit the force release mechanism jammed repeatedly. Detailed procedures for initial acceptance testing and continuing quality control checks are listed. Recommended measurements include levels of manual and automatic applied force, stability, reproducibility, and dependence on angulation and breast size and evaluation of operation of release mechanisms. Also necessary are observations of the condition and operation of the compression system. Test equipment is described and measurement frequency is specified, as well as suggested tolerance limits. Manufacturers of mammographic units are urged to build in compression-force gauges and to provide both a manual mode and a variable-force automatic mode.