106 results about "Particle sorting" patented technology

The invention discloses an aggregate random distribution concrete PFC (Power Factor Correction) simulation method, which comprises the following steps: a model selection step: determining a parallel bonding model as a mechanical model for concrete material simulation; a cement mortar matrix generation step of generating a cement mortar matrix by using particles in a set size range in a set space range based on the model, and setting pore density, particle density and contact model parameters; a coarse aggregate random distribution simulation step: randomly covering and grouping original particles in the matrix in a grouping and range mode; a concrete numerical model construction step: determining particle classification so as to distinguish cement mortar and coarse aggregate; and a model reliability verification step: comparing indoor test results through a uniaxial compression test. According to the method, the simulation accuracy is improved, the randomness of aggregate is reduced, the model reliability is ensured, the matrix simulation refinement degree is improved, and a method is provided for concrete modeling and performance research.

The utility model discloses a coral sand particle size and shape double sorting device which comprises a plurality of sorting systems, a sorting system fixing support and a screening machine, and the sorting systems comprise a particle size sorting system, a flaky particle sorting system and a block-shaped and rod-shaped particle sorting system which are sequentially connected from top to bottom. The screening machine is compatible with an existing standard inspection screening machine and is simple in structure, complex mechanical equipment does not need to be introduced on the basis that a traditional particle size sorting function is reserved, the screen is customized according to needs during use, and the equipment transformation cost is remarkably reduced; the device disclosed by the utility model can be used for simultaneously screening various sample particles in different target particle size ranges and respectively screening the sample particles in different target particle size ranges in a sheet shape, a block shape and a rod shape.

The utility model discloses a device for sorting copper and aluminum particles after crushing of waste lithium batteries, which is provided with a vibrating screen (1), and a material inlet at the upper part of the vibrating screen (1) receives materials generated by a crusher; the sorting device is also provided with a large particle sorting machine (4) and a small particle sorting machine (6); and a large particle outlet and a small particle outlet of the vibrating screen (1) are respectively connected with the large particle sorting machine (4) and the small particle sorting machine (6) through the conveying pipeline (3). By the adoption of the technical scheme, the copper-aluminum mixture generated in the waste lithium battery crushing and sorting process can be efficiently sorted, high-purity copper particles and aluminum particles are obtained, and recycling of waste materials is achieved; the process is reasonable and feasible, equipment is simple, and recovery cost is low.

The invention relates to a hundred-nanoscale particle sorting control chip and device and a sorting control method, the chip comprises a micro lens, a micro-fluidic channel, a sorting outlet and a sorting inlet, the sorting outlet is a two-fork opening, and the sorting inlet is a three-fork opening and comprises a sample inflow opening and two focusing inflow openings; the sorting inlets and the sorting outlets are formed in the two ends of the micro-fluidic channel respectively, and the micro-lens is arranged at the intersection of the two sorting outlets. The device comprises a chip, a light source, an injection device and an observation platform, light emitted by the light source penetrates through a micro lens and irradiates into a micro-fluidic channel, light force is applied to particles in fluid to be sorted, the particles of different sizes enter different sorting outlets, and finally sorting is achieved. Compared with the prior art, the particle sorting device can realize quick sorting of particles with the diameter of hundreds of nanometers, has the advantages of high sorting efficiency, high control precision and the like, and has important application value in sorting and control of micro-nano-scale particles such as viruses, bacteria and the like.

The invention relates to an SPH pollutant transport simulation method based on background grid division particle dormancy. The method comprises the following steps: initializing parallel computing parameters and initializing particle information; copying the to-be-processed data from the CPU end to the GPU end; parallel computing of the SPH method is carried out, wherein the parallel computing comprises the steps of background grid division, particle sorting, background grid state updating, background grid classification, particle searching and computing, dynamic updating grid classification, particle interaction computing solution diffusion, particle position updating, boundary condition processing and repeated iteration; and copying the result data back to the CPU end from the GPU end, and exporting the result data for subsequent analysis and visualization.

The utility model discloses a needle-sheet-shaped railway ballast particle screening device, and relates to the technical field of railway engineering material detection and particle sorting. When the number of the screen assemblies is larger than or equal to 2, the screen assemblies are sequentially stacked in the vertical direction. In the vertical direction, the average particle size of the corresponding size fraction of each screen assembly is gradually reduced from top to bottom in sequence; the screen assembly comprises a needle-shaped screen device, a sheet-shaped screen device and a grading screen device which are sequentially communicated from top to bottom in the vertical direction. A plurality of first screen holes are formed in the bottom of the needle-shaped screen device, and the first screen holes are used for intercepting needle-shaped particles in the size fraction; a plurality of second screen holes are formed in the sheet-shaped screen mesh device, and the second screen holes are used for screening sheet-shaped particles in the size fraction to fall onto the grading screen mesh; a plurality of third screen holes are formed in the grading screen device, and the third screen holes are used for conducting preliminary screening on the size fraction corresponding to the next screen assembly. And efficient separation of needle-sheet-shaped particles is achieved, and the working efficiency is improved.

The invention relates to an intelligent particle identification method for lunar soil particle screening, which comprises the following steps of: acquiring an optical signal, image data and a surface electrical signal of the same lunar soil sample particle to form a multi-modal feature set of each lunar soil sample particle; carrying out standardization processing on the multi-modal feature set; constructing a multi-modal deep learning neural network model based on a CNN + MLP + splicing fusion module structure; performing supervised learning training on the multi-modal deep learning neural network model to obtain a trained multi-modal deep learning neural network model; and inputting the standardized data into the trained multi-modal deep learning neural network model to realize particle classification. According to the method, an intelligent identification integrated deep learning model is adopted, the functions of particle shape distinguishing, component identification, particle size sorting and the like are carried out by utilizing an intelligent algorithm, automatic classification, clustering and attribute prediction can be realized, manual marking one by one is not needed, and the working efficiency is effectively improved.

The invention provides a tailing particle classification method based on multi-dimensional morphological feature compression and clustering, and belongs to the technical field of geotechnical engineering, mineral processing and particle classification, and the method comprises the following steps: S1-S6, obtaining an STL file database of tailing particles; s7, calculating and extracting morphological parameters to form an original parameter data set; s8-S10: obtaining a three-dimensional morphological parameter set which retains the original morphological feature information; s11-S12, determining an optimal clustering number by adopting an elbow rule, a contour coefficient and Gap statistics, and performing particle morphology clustering grouping on the three-dimensional morphology parameters by adopting a K-means algorithm; and S13, carrying out stacking test simulation on the clustered particle categories by using a discrete element method, analyzing the stacking density and the average coordination number of different categories of particles, and verifying the physical significance of a classification result. The tailing particle classification method can systematically and efficiently integrate particle multi-dimensional form information, can directly associate the information with macroscopic physical and mechanical properties, and is data-driven, clear in mechanism and explainable in result.

The invention is directed to a micromechanical device for sorting at least two distinct fractions of target particles and at least one non-target target particle from each other, all suspended in a fluid, comprising: - a source of magnetic flux (1) - a movable member (2) comprising permeable magnetic material (3) wherein the movable member (2) is moved from a first position (4) to a second position (5) and / or one or more third positions (6) by applying a magnetic flux to the movable member (2) - a sample inlet channel (7) through which the fluid flows into the micromechanical device - a first output channel (8) which the movable member (2) diverts the non-target particles while being in the first position (4) - a second output channel (9) into which the movable member (2) diverts one distinct fraction of the target particles while being in the second position (5) - one or more third output channels (10) into which the movable member (2) diverts further distinct fractions of the target particles while being in one of the one or more third position (6) - a spring (11) attached to the movable member (2) providing mechanical resistance to the movable member (2) when moving from the first position (4) to the second position (5) and / or to one or more of the third positions (6) characterized in that the spring (11) has non-linear elastomechanical properties when the movable member (2) is at the second position (5) and / or at one or more of the third positions (6).

The utility model relates to the technical field of particle separation, in particular to a cyclone fine particle separation device capable of adjusting granularity, which comprises a stirrer and a cyclone, the top of the cyclone is fixedly connected with an end table, the upper end face of the end table is provided with a through groove in a penetrating manner, the inner side of a rotary drum is rotatably connected with an overflow pipe, and the overflow pipe is provided with a through hole. And a spiral groove is formed in the outer wall of the rotary drum in a penetrating manner. When the rotary knob is rotated, the rotary drum is driven to rotate, the rotary drum rotates to drive the spiral groove in the outer wall of the rotary drum to rotate, and the limiting block fixed to the outer wall of the overflow pipe extends into the spiral groove, so that when the spiral groove rotates, the limiting block moves along the track of the spiral groove, the limiting block is limited through the clamping groove, and the limiting block can only move in the vertical direction; therefore, when the rotary drum is rotated, the overflow pipe is driven to move up and down, so that the insertion depth of the overflow pipe can be adjusted according to needs, medium particle size composition changes and the requirements for grading indexes are better met, and the grading particle size is adjusted on line.

The invention relates to a particle micro-explosion combustion event detection and particle classification method based on multi-factor scoring, which takes a trajectory splitting event as a core, combines and analyzes a'termination trajectory 'and a'new trajectory' as a candidate condition of a primary micro-explosion combustion event, and converts a tracking problem from position tracking into identification and judgment of a physical process. Tracking errors caused by accidental factors in the particle tracking process can be reduced; through a two-step screening strategy of'deterministic screening 'and'probabilistic screening', the inherent'velocity attribute 'of the sub-particles can be effectively combined, a group determined as the sub-particles is firstly screened out, and the calculated amount of subsequent'probabilistic screening' is reduced; furthermore, a comprehensive scoring model is established, the micro-explosion characteristics of the mother particles are associated with the group characteristics of the child particles, a'probabilities screening 'strategy based on multi-dimensional associated information analysis is formed, the accuracy of particle classification is effectively improved, and high-precision and high-robustness recognition of the metal particle micro-explosion combustion event in the motion state is achieved.

A microfluidic device includes a particle sorting region having a first, second and third microfluidic channels, a first array of islands separating the first microfluidic channel from the second microfluidic channel, and a second array of islands separating the first microfluidic channel from the third microfluidic channel, in which the island arrays and the microfluidic channels are arranged so that a first fluid is extracted from the first microfluidic channel into the second microfluidic channel and a second fluid is extracted from the third microfluidic channel into the first microfluidic channel, and so that particles are transferred from the first fluid sample into the second fluid sample within the first microfluidic channel.

The present application relates to a kind of hundred nanometer level particle sorting manipulation chip, device and sorting manipulation method, the chip includes microlens, microfluidic channel, sorting outlet and sorting inlet, the sorting outlet is bifurcation, the sorting inlet is trifurcation, including sample flow inlet and 2 focus flow inlets;Sorting inlet and sorting outlet are respectively arranged at the two ends of microfluidic channel, and microlens is arranged at the intersection of 2 sorting outlets.The device includes chip, light source, injection device and observation platform, and the light emitted by light source is irradiated into microfluidic channel through microlens, and light force is applied to the particle in the fluid to be sorted, and different size particles enter different sorting outlets, finally realize sorting.Compared with prior art, the present application can realize the rapid sorting of hundred nanometer level particle, with the advantages of high sorting efficiency, high control precision, etc., and has important application value for the sorting and manipulation of micro-nano scale particles such as virus and bacteria.

The invention relates to the technical field of particle sorting, and discloses calf concentrate raw material mildewed particle sorting equipment which comprises a mounting shell, a plurality of rectangular mounting parts distributed at equal intervals are arranged outside the mounting shell in a sleeving mode, a feeding port is formed in the upper portion of the mounting shell, and a triangular discharging block is arranged in an inner cavity of the feeding port; discharging ports are further formed in the two opposite side walls of the mounting shell, discharging port sealing plates are arranged on the discharging ports, and the two discharging port sealing plates are symmetrical to each other. According to the device, through cooperation of the special-shaped sliding groove openings and the sliding balls, the fixing plate is driven to press downwards to promote the placement plate to incline, air nozzles of the air exhaust shell are matched for auxiliary discharging, an inclined discharging plate is matched for guiding, mildew detection and sorting are completed synchronously, and sorting is efficient; the whole structure is stably installed through a rectangular installation part, the raw material storage and detection accuracy is guaranteed through a discharging port sealing plate and a placing plate sealing plate, the sorting reliability is greatly improved, and the calf breeding safety is guaranteed in an assisting mode.

This invention provides an arc-shaped deterministic lateral displacement chip and its application method. The chip includes a target curved flow channel, which is a curve with a curvature greater than 0 and bending towards one side; and an array of barrier columns disposed inside the target curved flow channel. The barrier column array includes multiple orderly arranged barrier columns, and particles of different sizes travel different paths when the particle solution flows through the barrier column array. This solution sets up an array of barrier columns formed by multiple orderly arranged barrier columns within a target curved flow channel with a curvature greater than 0 and bending towards one side, thereby shortening the length of the flow channel and reducing the area occupied by the flow channel without sacrificing particle sorting accuracy. Furthermore, the arc-shaped deterministic lateral displacement chip provided in this specification can efficiently sort particles with adhesive properties, and can also accurately sort larger particles while filtering impurities in particle solutions.

The utility model relates to the technical field of modified plastic particle sorting, in particular to a modified plastic particle vibration sorting device which comprises a sorting box, the upper surface of the sorting box is communicated with one end of a connecting pipe, a material distributing assembly is arranged in the connecting pipe, and the other end of the connecting pipe is communicated with one end of a discharging pipe. The other end of the discharging pipe communicates with the lower surface of a storage barrel, the upper surface of the storage barrel communicates with one end of a feeding pipe, a vibration motor vibrates to drive a mounting plate and a rubber column to vibrate, the rubber column transmits vibration to three sieve plates, modified plastic particles are sieved through the three sieve plates, and the modified plastic particles are screened through the three sieve plates. And the air cylinder drives the sliding block b and the brush to move rightwards, the brush moves rightwards to clean the modified plastic particles on the upper surface of the screen plate, and the problem that the particle sorting efficiency is obviously reduced along with the increase of blockage of meshes due to the fact that the meshes of a screen of an existing device often clamp some particles is solved.

To provide a particle classification device and a particle classification method.SOLUTION: A particle classification device comprises: a supply chamber 51 which supplies a suspension solution 11 in which particles are dispersed; a filtration chamber 52 which allows fine particle components in the solution to pass therethrough by an electric-field filtration action and retains a concentrated liquid of coarse particle components; and a filtrate chamber 53 which discharges, to the outside, a filtrate including the fine particle components that have passed through. The filtration chamber 52 includes: a plate-shaped anode electrode 14 disposed on a supply chamber side and having through holes; and a cathode filter plate electrode 14 disposed on a filtrate chamber 53 side, including a diaphragm 13 having pores that block negatively-charged coarse particle components and having pores.SELECTED DRAWING: Figure 1

The invention discloses an automatic filling device for radioactive particles, and the device comprises a particle sorting mechanism which is used for sorting the radioactive particles; the cartridge holder mounting mechanism is used for mounting a cartridge holder so as to fill the radioactive particles sequenced by the particle sequencing mechanism; the particle conveying mechanism is used for receiving the radioactive particles sorted by the particle sorting mechanism and conveying the radioactive particles to a filling position of the cartridge holder mounting mechanism; the particle pushing mechanism is used for pushing the radioactive particles conveyed by the particle conveying mechanism into the cartridge holder; the cartridge holder control mechanism is used for enabling the cartridge holder to make a particle filling position so as to receive the radioactive particles pushed by the particle pushing mechanism; the particle blocking mechanism is mounted on the cartridge holder mounting mechanism and is used for opening or closing a discharge hole of the particle sorting mechanism; the particle sorting mechanism, the particle conveying mechanism, the particle pushing mechanism and the cartridge holder control mechanism are in signal connection with the control unit. According to the automatic filling device provided by the invention, the particle filling efficiency and safety can be improved.

The utility model belongs to the field of plastic production, and particularly relates to an automatic plastic particle sorting machine which comprises a rinsing tank, the rinsing tank is provided with a liquid discharge pipe, the liquid discharge pipe is provided with a second valve, the rinsing tank is provided with a drainage slide way, the drainage slide way is provided with a conical funnel, and a filter screen is assembled at the communication position of the conical funnel and the drainage slide way. The conical funnel is provided with a connecting pipe, the connecting pipe is assembled with the liquid discharging pipe, the drainage sliding way is provided with a connecting block, the connecting block is provided with a liquid receiving box, the liquid receiving box is provided with a connecting rod, the connecting rod is provided with a sliding block, the sliding block is provided with a screen box, and the screen box is provided with a vertical block. According to the automatic sorting machine for the plastic particles, through cooperation of the screen box and the filter screen, the problems that in the production process of existing plastic raw material particles, external dust is prone to being adsorbed to the surfaces of the plastic raw material particles, the sorting effect is poor only by vibrating the plastic particles, meanwhile, noise is large when a vibration motor works, and influences are generated on the surroundings are solved.

Aspects of the present disclosure include methods for adjusting a particle classification index in response to one or more saturated data signals based on detected light from particles in a fluid stream. Methods according to certain embodiments include detecting light from particles in a fluid stream, generating a plurality of data signals based on the detected light, identifying one or more saturated data signals, generating a saturation signal index corresponding to the identified saturated data signals, and applying the saturation signal index to a particle classification index to generate an adjusted particle classification index. In some embodiments, the methods include determining one or more parameters of a particle (e.g., for a particle sorting decision) by calculating an adjusted spectral unmixing matrix for fluorescence of the particle that excludes the one or more saturated data signals. Systems and integrated circuit devices (e.g., field programmable gate arrays) for implementing the subject methods are also provided. Non-transitory computer readable storage media are also described.

The invention belongs to the technical field of construction waste sorting and recycling, and particularly discloses a construction waste particle sorting device which comprises a mounting box, one side of the mounting box is fixedly connected with a first discharging shell, and the other side of the mounting box is fixedly connected with a second discharging shell communicating with the first discharging shell. And the top of the mounting box is fixedly connected with a third discharge shell. By arranging the separation mechanism, the three functions of particle size screening, wind power sorting and magnetic separation impurity removal are organically combined in the same device, and the technical problems that traditional sorting equipment is single in function and needs multi-machine linkage are solved; according to the technical scheme, adsorption separation of metal substances, wind separation of light materials and screening classification of aggregates with different particle sizes are sequentially completed, finally, metal materials, light sundries and heavy aggregates are output through three independent discharging channels correspondingly, efficient fine separation of construction waste is achieved, and the purity and the additional value of recycling products are remarkably improved.

This invention provides a tailings particle classification method based on multi-dimensional morphological feature compression and clustering, belonging to the fields of geotechnical engineering, mineral processing, and particle classification technology. The method includes: S1-S6: acquiring an STL file database of tailings particles; S7: calculating and extracting morphological parameters to form an original parameter dataset; S8-S10: obtaining a three-dimensional morphological parameter set retaining the original morphological feature information; S11-S12: determining the optimal number of clusters using the elbow rule, silhouette coefficient, and Gap statistic, and using the K-means algorithm to cluster the three-dimensional morphological parameters into particle morphology groups; S13: using the discrete element method to conduct a stacking test simulation on the clustered particle categories, analyzing the stacking density and average coordination number of different particle categories, and verifying the physical meaning of the classification results. This tailings particle classification method can systematically and efficiently integrate multi-dimensional particle morphological information and directly correlate this information with macroscopic physical and mechanical properties. It is data-driven, has a clear mechanism, and the results are interpretable.

The invention belongs to the related technical field of phase segmentation, and discloses a decoupling type phase segmentation method and system for a composite gel system microstructure, and the method comprises the steps: (1) forming a reusable particle database through particle images corresponding to each kind of target gel particles; (2) taking an artificially marked pure cement paste BSE image as a background image, inserting particles in a reusable particle database into a cement matrix area to obtain a stage 1 model training data set, and training a stage 1 universal segmentation model; (3) training the stage 2 particle classification model by adopting particles in the reusable particle database; (4) inputting the BSE image to be subjected to phase splitting into the stage 1 universal segmentation model to obtain a matrix, a pore and a particle mask; and stage 2, the classification model performs joint classification based on the particle masks and all particles in the BSE image to be subjected to phase splitting so as to obtain the specific phase category of each particle. According to the invention, the universality is improved.

A device for sorting particles from a fluid. The device defines an inlet for receiving sample particles carried in a fluid, at least one channel for passage of the sample and fluid through the device, and a sort outlet for passing sorted particles out of the device. The device comprises a particle focuser, a heater pocket, at least one laser pocket, a vortex generating element and a sorting junction along the at least one channel. The at least one laser pocket is provided downstream of the heater pocket and upstream of the vortex generating feature such that, in use, particles entering the device are focussed within the channel, detected by laser light passing through the at least one laser pocket and deflected to the sort outlet by a vortex generated at the vortex generating component by activation of a heater positioned at the heater pocket.

Aspects of the present disclosure include methods for tagless particle sorting. A method according to certain embodiments includes measuring light from a sample having untagged particles in a flow stream, generating an image of one or more of the particles from the measured light, calculating image parameters from the generated image of the one or more particles, and generating a particle sorting decision based on the calculated image parameters. In some embodiments, a sorting gate is determined based on image parameters calculated from particles and real image classification parameters. Systems and integrated circuit devices (e.g., field programmable gate arrays) for practicing the subject methods are also described. A non-transitory computer-readable storage medium is also provided.

The invention discloses an ocean micro-plastic particle sorting and enriching integrated device and method based on bidirectional acoustic surface waves, and belongs to the crossing field of an acoustic micro-fluidic technology and ocean environment monitoring. According to the device, an inclined micro-channel design and a standing wave sound field coupling mechanism are adopted, flexible interdigital transducers which are symmetrically arranged in a sorting module are used for exciting surface acoustic waves with specific frequencies, and a high-strength sound pressure standing wave field is formed in a micro-channel. According to the particle size distribution characteristics of micro-plastic particles in the marine environment, efficient sorting of micro-plastic is achieved by accurately regulating and controlling acoustic radiation force parameters. And the sorted micro-plastics are directly introduced into the annular enrichment module, and the sound streaming effect generated by a traveling wave sound field is utilized to realize rapid enrichment of particles. According to the device, the technical bottleneck of sample transfer loss in the traditional method is overcome through the integrated design of the sorting and enriching process, and a high-sensitivity and low-cost pretreatment solution is provided for marine micro-plastic pollution monitoring.

The application discloses a micro-fluidic chip device for continuously integrating inertial sorting of large-size cells, which comprises a shell and a continuous multi-stage sorting device arranged in the shell. The shell is provided with a mixed particle solution inlet, a target ion solution outlet and an impurity particle outlet communicated with inlets and outlets of the continuous multi-stage sorting device. Particle sorting units of two adjacent stages of the sorting device are exponentially increased. The micro-fluidic chip device is provided with a side channel at a discharging end of a micro-groove, which can greatly improve the sorting efficiency of particles / cells, and the target particle / cell solution after capture can be directly collected without secondary treatment.

The invention discloses a particle sorting micro-fluidic chip integrated with a piezoelectric actuator and a use method of the particle sorting micro-fluidic chip, and relates to the technical field of micro-fluidic sorting. The device comprises a particle inlet, a jet liquid inlet, two sorting outlets, a sorting area and a piezoelectric actuator. The jet flow cavity is in fluid communication with the sorting area, and a jet flow outlet of the jet flow cavity is located at the highest gravity position, so that gas in the jet flow cavity can be discharged through the jet flow outlet under the action of gravity. According to the invention, the chip is vertically or obliquely placed, so that the jet flow outlet is located at a functional position which is beneficial to natural gathering and discharging of gas under the action of gravity, and bubbles in the cavity are naturally discharged by utilizing the gravity. The jet flow actuating efficiency is improved, the sorting process has higher tolerance to the initial transverse position, the arrival time sequence and the size fluctuation of the particles, and stable and high-purity particle sorting can be achieved without depending on the high-precision pre-alignment condition.

The application discloses a kind of high-efficiency low-resistance coarse-fine gradient grading and sorting mechanism and its application, from bottom to top including the air distribution material distribution area and pre-dispersion and coarse particle grading area connected;Air distribution material distribution area includes air inlet shell, air inlet, coarse particle outlet, flow guide cone and annular air ring, pre-dispersion and coarse particle grading area includes coarse particle sorting shell, coarse particle sorting rotating cage, distribution device and coarse particle sorting drive, distribution device is located at the top of coarse particle grading area and is located above the upper ring plate of coarse particle sorting rotating cage, distribution device is composed of distribution disc and dispersion vane, distribution disc is fastened on the upper ring plate, and dispersion vane is evenly distributed on distribution disc in uniform radial distribution;Multiple feeding ports are evenly provided on the support cover plate corresponding to the top of distribution disc.The present application has the functions of dispersion, distribution, coarse-fine particle separation, can be well matched with traditional dynamic powder concentrator, complete more clear particle sorting, coarse particle sorting clarity is higher, powder selection resistance is lower, and the service life of wearing parts is longer.