1,182 research outputs found
Method and Apparatus for Triboelectric-Centrifugal Separation
A method for separating two species of particles present in raw feedstock includes electrically charging at least one of the species of particles being separated. Next is the subjecting of the particles to both centrifugal and electrostatic forces. This is done in a manner so as to provide an additive effect and thereby achieve enhanced separation of the two particle species. An apparatus for processing the raw feedstock in accordance with the method is also disclosed
Electrostatic Particle Separation System, Apparatus, and Related Method
An electrostatic separation apparatus or system is provided for separating a particle mixture into two constituent species. The system includes a distributor for differentially tribocharging the particle species forming the mixture and supplying the charged mixture to a plurality of electrostatic separation cells. Each cell includes at least one separator having an inlet, a separation chamber having an electric field zone for drawing selected charged particles from the particle mixture, a collector, and a transition outlet. The length of the electric field zone is selectively adjustable for varying the charged particle drawing action. A curtain gas flow introduced into the separation chamber carries the selected charged particles drawn from the particle mixture in the electric field zone to the collector. Flow vanes or straighteners are provided for both the particle mixture flow and the curtain gas flow to reduce turbulence in the separation chamber and improve separation efficiency. The collector includes a discharge outlet for discharging the selected charged particles to a first collection bin. The transition outlet receives the remaining particle flow and delivers it to a second collection bin for recovery or to a second separator to collect any remaining selected charged particles. The transition outlet reforms the flow to create turbulence to further tribocharge the particles prior to entering the second separator. A related method of particle separation is also disclosed
Particle Separation System Using Parallel Multistage Electrostatic Separators
An electrostatic separation apparatus includes of a plurality of separators is provided for separating a particle mixture into two constituent species. Each separator includes one and preferably a plurality of modular separation stages. Each stage of the separator includes a pair of separation subchambers each having an electric field zone for drawing selected charged particles from the particle mixture. A curtain gas flow is provided for each subchamber to entrain and carry the selected charged particles drawn from the particle mixture in the electric field zone to a collector associated with each subchamber for recovery. The inlets for the particle mixture and curtain gas flows are adapted to straighten and smooth the respective flows to reduce turbulence in the separation subchambers and improve separation efficiency. The particle flow remaining after the first separation stage passes through an outlet to a second stage, a recycle line, or if further separation is deemed unnecessary, to a collection device for recovery. The apparatus may include a plurality of single or multistage separators arranged in parallel such that simultaneous operation is possible. Further, the apparatus may be included as part of an overall separation system
The Axis of Complement C1 and Nucleolus in Antinuclear Autoimmunity
Antinuclear autoantibodies (ANA) are heterogeneous self-reactive antibodies that target the chromatin network, the speckled, the nucleoli, and other nuclear regions. The immunological aberration for ANA production remains partially understood, but ANA are known to be pathogenic, especially, in systemic lupus erythematosus (SLE). Most SLE patients exhibit a highly polygenic disease involving multiple organs, but in rare complement C1q, C1r, or C1s deficiencies, the disease can become largely monogenic. Increasing evidence point to intrinsic autoimmunogenicity of the nuclei. Necrotic cells release fragmented chromatins as nucleosomes and the alarmin HMGB1 is associated with the nucleosomes to activate TLRs and confer anti-chromatin autoimmunogenecity. In speckled regions, the major ANA targets Sm/RNP and SSA/Ro contain snRNAs that confer autoimmunogenecity to Sm/RNP and SSA/Ro antigens. Recently, three GAR/RGG-containing alarmins have been identified in the nucleolus that helps explain its high autoimmunogenicity. Interestingly, C1q binds to the nucleoli exposed by necrotic cells to cause protease C1r and C1s activation. C1s cleaves HMGB1 to inactive its alarmin activity. C1 proteases also degrade many nucleolar autoantigens including nucleolin, a major GAR/RGG-containing autoantigen and alarmin. It appears that the different nuclear regions are intrinsically autoimmunogenic by containing autoantigens and alarmins. However, the extracellular complement C1 complex function to dampen nuclear autoimmunogenecity by degrading these nuclear proteins
Blunt popliteal artery injury following tibiofemoral trauma: vessel-first and bone-first strategy
Purpose: Blunt popliteal artery injury (BPAI) is a potentially limb-threatening sequela of tibiofemoral (knee) dislocations and fractures. Associated amputation rates for all popliteal artery (PA) injuries range between 10 and 50%. It is unclear whether PA repair or bone stabilization should be performed first. We analyzed (long-term) clinical outcomes of BPAI patients that received initial PA repair (vessel-first, VF) versus initial external stabilization (bone-first, BF). Methods: Retrospectively, all surgically treated BPAI patients between January 2000 and January 2019, admitted to two level 1 trauma centers were included. Clinical outcomes were determined, stratified by initial management strategy (VF and BF). Treatment strategy was determined by surgeon preference, based on associated injuries and ischemia duration. Primary outcomes (amputation and mortality) and secondary outcomes (claudication and complications) were determined. Results: Of 27 included BPAI patients, 15 were treated according to the VF strategy (56%) and 12 according to the BF strategy (44%). Occlusion was the most frequently encountered BPAI in 18/27 patients (67%). Total delay and in-hospital delay were comparable between groups (p = 1.00 and p = 0.82). Revascularization was most frequently performed by PA bypass (59%). All patients had primary limb salvage during admission (100%). One secondary amputation due to knee pain was performed in the BF group (4%). During a median clinical follow-up period of 2.7 years, three PA re-interventions were performed, two in the BF group and one in the VF group. None suffered from (intermittent) claudication. Conclusion: Blunt popliteal artery injury (BPAI) is a rare surgical emergency. Long-term outcomes of early revascularization for BPAI appear to be good, independent of initial management strategy. The BF strategy may be preferred in case of severe orthopedic injury, if allowed by total ischemia duration
Diagnostic Performance of convolutional neural networks for dental sexual dimorphism
Convolutional neural networks (CNN) led to important solutions in the field of Computer Vision. More recently, forensic sciences benefited from the resources of artificial intelligence, especially in procedures that normally require operator-dependent steps. Forensic tools for sexual dimorphism based on morphological dental traits are available but have limited performance. This study aimed to test the application of a machine learning setup to distinguish females and males using dentomaxillofacial features from a radiographic dataset. The sample consisted of panoramic radiographs (n = 4003) of individuals in the age interval of 6 and 22.9 years. Image annotation was performed with V7 software (V7labs, London, UK). From Scratch (FS) and Transfer Learning (TL) CNN architectures were compared, and diagnostic accuracy tests were used. TL (82%) performed better than FS (71%). The correct classifications of females and males aged ≥ 15 years were 87% and 84%, respectively. For females and males < 15 years, the correct classifications were 80% and 83%, respectively. The Area Under the Curve (AUC) from Receiver-operating Characteristic (ROC) curves showed high classification accuracy between 0.87 and 0.91. The radio-diagnostic use of CNN for sexual dimorphism showed positive outcomes and promising forensic applications to the field of dental human identification
Binary decisions of artificial intelligence to classify third molar development around the legal age thresholds of 14, 16 and 18 years
Third molar development is used for dental age estimation when all the other teeth are fully mature. In most medicolegal facilities, dental age estimation is an operator-dependent procedure. During the examination of unaccompanied and undocumented minors, this procedure may lead to binary decisions around age thresholds of legal interest, namely the ages of 14, 16 and 18 years. This study aimed to test the performance of artificial intelligence to classify individuals below and above the legal age thresholds of 14, 16 and 18 years using third molar development. The sample consisted of 11,640 panoramic radiographs (9680 used for training and 1960 used for validation) of males (n = 5400) and females (n = 6240) between 6 and 22.9 years. Computer-based image annotation was performed with V7 software (V7labs, London, UK). The region of interest was the mandibular left third molar (T38) outlined with a semi-automated contour. DenseNet121 was the Convolutional Neural Network (CNN) of choice and was used with Transfer Learning. After Receiver-operating characteristic curves, the area under the curve (AUC) was 0.87 and 0.86 to classify males and females below and above the age of 14, respectively. For the age threshold of 16, the AUC values were 0.88 (males) and 0.83 (females), while for the age of 18, AUC were 0.94 (males) and 0.83 (females). Specificity rates were always between 0.80 and 0.92. Artificial intelligence was able to classify male and females below and above the legal age thresholds of 14, 16 and 18 years with high accuracy.</p
Binary decisions of artificial intelligence to classify third molar development around the legal age thresholds of 14, 16 and 18 years
Third molar development is used for dental age estimation when all the other teeth are fully mature. In most medicolegal facilities, dental age estimation is an operator-dependent procedure. During the examination of unaccompanied and undocumented minors, this procedure may lead to binary decisions around age thresholds of legal interest, namely the ages of 14, 16 and 18 years. This study aimed to test the performance of artificial intelligence to classify individuals below and above the legal age thresholds of 14, 16 and 18 years using third molar development. The sample consisted of 11,640 panoramic radiographs (9680 used for training and 1960 used for validation) of males (n = 5400) and females (n = 6240) between 6 and 22.9 years. Computer-based image annotation was performed with V7 software (V7labs, London, UK). The region of interest was the mandibular left third molar (T38) outlined with a semi-automated contour. DenseNet121 was the Convolutional Neural Network (CNN) of choice and was used with Transfer Learning. After Receiver-operating characteristic curves, the area under the curve (AUC) was 0.87 and 0.86 to classify males and females below and above the age of 14, respectively. For the age threshold of 16, the AUC values were 0.88 (males) and 0.83 (females), while for the age of 18, AUC were 0.94 (males) and 0.83 (females). Specificity rates were always between 0.80 and 0.92. Artificial intelligence was able to classify male and females below and above the legal age thresholds of 14, 16 and 18 years with high accuracy.</p
Electrochemically Reconfigurable Architected Materials
Architected materials can actively respond to external stimuli—such as mechanical forces, hydration and magnetic fields—by changing their geometries and thereby achieve novel functionalities. Such transformations are usually binary and volatile because they toggle between ‘on’ and ‘off’ states and require persistent external stimuli. Here we develop three-dimensional silicon-coated tetragonal microlattices that transform into sinusoidal patterns via cooperative beam buckling in response to an electrochemically driven silicon-lithium alloying reaction. In situ microscopy reveals a controllable, non-volatile and reversible structural transformation that forms multiple ordered buckling domains separated by distorted domain boundaries. We investigate the mechanical dynamics of individual buckling beams, cooperative coupling among neighbouring beams, and lithiation-rate-dependent distributions of domain sizes through chemo-mechanical modelling and statistical mechanics analysis. Our results highlight the critical role of defects and energy fluctuations in the dynamic response of architected materials. We further demonstrate that domain boundaries can be programmed to form particular patterns by pre-designing artificial defects, and that a variety of reconfigurational degrees of freedom can be achieved through micro-architecture design. This framework enables the design, fabrication, modelling, behaviour prediction and programming of electrochemically reconfigurable architected materials, and could open the way to beyond-intercalation battery electrodes, tunable phononic crystals and bio-implantable devices
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