Abstract: Use a solvent blend that contains 1methoxy-2,7-octadiene and an alkanols rather than the alkanols by itself to prepare a catalyst precursor suitable for use in butadiene telomerization.

Abstract: The present application discloses complexes useful as catalysts for organic chemical synthesis including hydrogenation and dehydrogenation of unsaturated compounds or dehydrogenation of substrates. The range of hydrogenation substrate compounds includes esters, lactones, oils and fats, resulting in alcohols, diols, and triols as reaction products. The catalysts of current application can be used to catalyze a hydrogenation reaction under solvent free conditions. The present catalysts also allow the hydrogenation to proceed without added base, and it can be used in place of the conventional reduction methods employing hydrides of the main-group elements. Furthermore, the catalysts of the present application can catalyze a dehydrogenation reaction under homogenous and/or acceptorless conditions. As such, the catalysts provided herein can be useful in substantially reducing cost and improving the environmental profile of manufacturing processes for variety of chemicals.

Abstract: A method of forming a film system includes depositing a monolayer formed from a fluorocarbon onto a substrate. After depositing, the method includes ablating the monolayer to define a plurality of cavities therein, wherein each of the plurality of cavities is spaced apart from an adjacent one of the plurality of cavities along the monolayer. After ablating, the method includes embedding a photocatalytic material into each of the plurality of cavities to form a film on the substrate and thereby form the film system. The film system includes a plurality of regions including the photocatalytic material and disposed within the monolayer such that each of the plurality of regions abuts and is surrounded by the fluorocarbon.

Abstract: Disclosed in the present invention are a preparation method for an olefin epoxidation catalyst and applications thereof. The method comprises: loading an auxiliary metal salt onto a silica gel carrier, and carrying out a drying treatment to the silica gel carrier; loading a titanium salt (preferably TiCl4) onto the silica gel carrier by a chemical vapor deposition method; calcining to obtain a silica gel on which the auxiliary metal oxide and Ti species are loaded; obtaining an catalyst precursor (Ti-MeO—SiO2 composite oxide) by water vapor washing; loading alkyl silicate (preferably tetraethyl orthosilicate) onto the surface of the catalyst precursor by a chemical vapor deposition method and calcining the catalyst precursor to obtain a Ti-MeO—SiO2 composite oxide with the surface coated with a SiO2 layer; and carrying out a silylanization treatment to obtain the catalyst.

Abstract: A process for preparing a composite material comprising an electride compound and an additive, said process comprising (i) providing a composition comprising the additive and a precursor compound of the electride compound, wherein the precursor compound comprises an oxidic compound of the garnet group, and wherein the additive has a boiling temperature which is higher than the melting temperature of the precursor compound; (ii) heating the composition provided in (i) under plasma forming conditions in a gas atmosphere to a temperature above the Hüttig temperature of the precursor compound and below the boiling temperature of the additive, obtaining the composite material.

Abstract: An object such as a cell colony may be picked from a plurality of objects by acquiring an image of the objects and an image of a pipette tip. The image of the objects is analyzed to select an object of interest. The selected object is associated with a coordinate position. Based on the coordinate position, the pipette tip is positioned over the selected object. An image of the pipette tip is then acquired and analyzed. The pipette tip is associated with a coordinate position. A positional error between the coordinate position of the selected object and the coordinate position of the pipette tip is determined. Based on the positional error, the pipette tip and/or a sample holder supporting the objects is moved to align the pipette tip over the selected object, by matching the coordinate position of the pipette tip with the coordinate position of the selected object.

Abstract: The invention relates to a pipette auxiliary system for supporting manual pipetting or dispensing of a plurality of samples of a sample-holding arrangement, in particular a microtiter plate.

Abstract: A sample-containing device configured to be placed into a sample processing instrument for performing a process on a sample contained in the device includes redundant identification features, such as machine-readable tags. A first machine-readable information tag is read before the device is placed in the instrument, and a second machine-readable information tag is read after the device is in the instrument. Information read from the two tags is compared to determine if there is proper correspondence between the information read from the tags to ensure that the correct sample processing device was placed in the instrument.

Abstract: An apparatus for manipulating magnetic particles includes a latch mechanism. The latch mechanism has a pivoting part provided on a door and an engaging part provided on a main body. In the apparatus for manipulating magnetic particles, a first contact portion of a latch engages with the engaging part at a contact point in a state that the door is closed. The contact point is located more outside of the main body than the pivot axis. Accordingly, in a case where an external force is applied to the door in a direction to open the door in a state that the door is closed, a force is applied from the engaging part to the first contact portion, thereby generating a rotational force in a C direction to the pivoting part. As a result, in the state that the door is closed, it is possible to suppress the door from being opened without a manipulation by the user.

Abstract: A sample test device is provided that includes a body having an insertion surface spaced apart from a distal end portion and a fluid manipulating assembly disposed in the distal end portion. A mixing receptacle is defined in the fluid manipulating assembly and provides a volume to mix a test mixture. A plunger is disposed in the body and creates a positive air pressure in the mixing receptacle when inserted into the body. A test die is disposed in the fluid manipulation assembly and a fluid path extends from the mixing receptacle to the test die. Activation of the plunger creates a positive pressure in the mixing receptacle to force the test mixture to flow from the mixing receptacle to the test die.

Abstract: An article of manufacture includes an array of distinct and separate regions with respective pharmaceutical compounds located thereon. The array of distinct and separate regions includes a first region with a first set of one or more pharmaceutical compounds located thereon; a second region, that is distinct and separate from the first region, with a second set of one or more pharmaceutical compounds, that is distinct from the first set of one or more pharmaceutical compounds, located thereon; and a third region, that is distinct and separate from the first region and the second region, with a third set of one or more pharmaceutical compounds, that is distinct from the first set of one or more pharmaceutical compounds and the second set of one or more pharmaceutical compounds, located thereon.

Abstract: The present disclosure provides a reaction cassette for biochemical test. The reaction cassette includes a structural wall, a first flow guiding member and an obstacle member. The structural wall defines a reaction region and a channel region, wherein the reaction region is connected to the channel region. The first flow guiding member is disposed in the channel region, and a first angle between the structural wall and the first flow guiding member ranges between 0 and 60 degrees. The obstacle member is disposed on the structural wall, and a second angle between the obstacle member and the structural wall is greater than 90 degrees. The present disclosure further provides an assay device including said reaction assay for biochemical test.

Abstract: Nucleic acid from cells and viruses sampled from a variety of environments may purified and expressed utilizing microfluidic techniques. Individual or small groups of cells or viruses may be isolated in microfluidic chambers by dilution, sorting, and/or segmentation. The isolated cells or viruses may be lysed directly in the microfluidic chamber, and the resulting nucleic acid purified by exposure to affinity beads. Subsequent elution of the purified nucleic acid may be followed by ligation and cell transformation, all within the same microfluidic chip. Cell isolation, lysis, and nucleic acid purification may be performed utilizing a highly parallelized microfluidic architecture to construct gDNA and cDNA libraries.

Abstract: Disclosed herein are systems and methods for serial flow emulsion processes. Systems and methods as described herein result in reduced cross-contamination.

Abstract: Disclosed are methods and systems concerning flow cells for sequencing a nucleic acid sample that may be characterized by the following components: a substrate having an inner surface facing a library sequencing region, and an outer surface; a plurality of a plurality of forward and reverse amplification primers immobilized over the inner surface and providing a nucleic acid library capture surface of the library sequencing region; a plurality of electrodes disposed along the inner surface directly under at least some of the forward and reverse amplification primers, and configured to provide, when charged, an electric field through the library capture surface and into the library sequencing region; electrical leads connected to the plurality of electrodes to permit the electrodes to be independently addressable; and fluidic couplings configured to deliver a plurality of nucleic acid libraries to the flow cell during different time periods.

Abstract: Provided is a microchip for analyzing fluids, the microchip comprising a body that comprises an upper surface and a lower surface, wherein fluid flows to internal channels formed between the upper surface and the lower surface to detect a specific antigen in the fluid, wherein the internal channels comprise an input channel configured such that an assay sample is injected through a through hole penetrating the upper surface; a reaction channel configured to be in fluid communication with the input channel, to comprise magnetic particles on which a first antibody is immobilized, to comprise magnetic particles to which the first antibody, subjected to a first antigen-antibody reaction with the assay sample having flowed from the input channel, is immobilized, wherein the magnetic particles form immune complexes through the first antigen-antibody reaction, and to have a higher height than the lower surface forming the input channel; and a detection channel configured to be in fluid communication with the reactio

Abstract: A microfluidic device, a method of using a microfluidic device and a micro total analysis system are provided. The microfluidic device includes a first substrate, and the first substrate includes a base substrate and a pixel array. The pixel array includes a plurality of pixels and is on the base substrate, and each of the plurality of pixels includes a driving electrode. Driving electrodes of two adjacent pixels are in different layers.

Abstract: A device for manipulating microdroplets using optically-mediated electrowetting comprising: a first composite wall comprising: a first transparent substrate; a first transparent conductor layer on the substrate having a thickness of 70 to 250 nm; a photoactive layer activated by electromagnetic radiation in the wavelength range 400-1000 nm on the conductor layer having a thickness of 300-1000 nm; and a first dielectric layer on the conductor layer having a thickness of 120-160 nm; a second composite wall comprised of: a second substrate; a second conductor layer on the substrate having a thickness of 70 to 250 nm; and an A/C source to provide a voltage across the first and second composite walls connecting the first and second conductor layers; at least one source of electromagnetic radiation having an energy higher than the bandgap of the photoexcitable layer; and means for manipulating the points of impingement of the electromagnetic radiation on the photoactive layer.

Abstract: A method of collecting a sample for determination of 1,4-dioxane in drinking water includes providing a reagent dispenser operable to dispense a microbial inhibitor. A sample bottle having a predetermined inner volume is provided to a preparation site. The dispenser is calibrated to dispense a calibrated weight of the microbial inhibitor, such that a ratio of the calibrated weight to inner volume substantially equals a predetermined concentration of microbial inhibitor per liter of water determined to acidify water to a pH of 4 or less. The sample bottle is transported to a field site. The field site is remote from the preparation site. A sample of water is collected in the sample bottle at the field site that substantially fills the inner volume of the sample bottle. The dispenser is operated to substantially dispense the calibrated weight of microbial inhibitor into the sample of water.

Abstract: Dried reagent strainers, such as cell strainers are provided. Aspects of the strainers include a body having an opening with a filter positioned in the opening, where the filter includes a dried reagent composition. Aspects of the invention further include methods of making and using the strainers, as well as kits containing the strainers.

Abstract: A receptacle holder having a base body, a first perimeter wall which at least partially protrudes from the base body, and a plurality of resilient elements, which are distributed about a first axis of the receptacle holder and are detachably connected with the first perimeter wall, and wherein each resilient element comprises a first end portion and a second end portion, and wherein each second end portion rests hooked over an edge of a portion of the first perimeter wall, and wherein the receptacle holder is configured to allow sliding of each second end portion in a direction perpendicular to the first axis.

Abstract: A food recycler can include a housing defining an interior and an access opening to the interior. A mixing bin can be located within the interior and can have an inlet and an outlet. The food recycler can further include an output bin, the output bin having an inlet. The outlet of the mixing bin can couple or connect to the inlet of the output bin.

Abstract: A small-scale waste processing device includes a housing, wherein a conveying cavity is provided in the housing, a screw is rotatably provided in the conveying cavity, a rotating cavity is provided in the housing, and the rotating cavity and the conveying The cavity is connected, and a rotating block is rotatably provided in the rotating cavity. A squeezing mechanism is provided in the rotating block. A first filter is fixedly arranged on the right wall of the rotating cavity. The present invention can pass kitchen wastes through Most of the water is squeezed out, and then the water in the waste is thrown out by throwing water to make the waste more dehydrated. The discharged waste water can be directly discharged to the sewer, which avoids clogging of the sewer and saves maintenance costs.

Abstract: The present invention is directed to a method for selectively recovering a sulphide mineral from an ore applying a collector being an alkylated triphenyl phosphorothionate. Further, the present invention is directed to the use of said alkylated triphenyl phosphorothionates to separate a target mineral from iron sulphide and/or silicate gangue.

Abstract: Methods for niobium concentration from a carbonatite host rock are presented. A basic process for niobium mineral concentration involves performing niobium mineral flotation, on a sufficiently liberated ore slurry, using at one least aromatic hydroxamate collector; and at least one lead salt as a performance modifier. A more optimized process further includes dispersion. A further optimized process includes: magnetic separation, dispersion, sulphide removal, fine suspended particle removal, and niobium cleaner flotation stages. The use of one of number of tested lead salts during flotation improves the yield, and lowers the cost as a significantly lower amount of the collector is required. The process is useful for recovering a variety of species of niobium minerals such as fersmite, pyrochlore, columbite, fergusonite, niobium-containing rutile, and niobium-containing ilmenite.

Abstract: A composite ozone flotation integrated device may include a cylinder body, an intermediate cylinder, and a central cylinder which are coaxial. The cylinder body and the center cylinder have a common bottom. The cylinder body and the intermediate cylinder have a common top. The intermediate cylinder is arranged on support channel steel between the cylinder body and the center cylinder. A top of the center cylinder is in the intermediate cylinder. The top of the center cylinder is open-mouthed. An upper part of the cylinder body is provided with a drainpipe. The top of the cylinder body is provided with an inner cylinder exhaust pipe and a slag discharge pipe. An upper part of the intermediate cylinder is provided with an outer cylinder exhaust pipe. A lower part of the center cylinder is connected to a water inlet pipe, a dissolved gas inlet pipe, and a venting and sludge-discharge pipe.

Abstract: A swinging bucket centrifuge (1) comprises a rotor (10) with at least one mounting end and at least one bucket (20) mounted to the at least one mounting end of the rotor (10). Therein, the at least one bucket (20) is mounted to the at least one mounting end of the rotor (10) by at least one clevis pin (30) held in a clevis (13) so that the bucket (20) is pivotable about the clevis pin (30).

Abstract: A method for operating a centrifugal separator associated with a prime mover and/or a working machine. The centrifugal separator comprises at least one rotatably mounted rotor that can be rotated at a variable speed via a drive controlled by a control unit. The method is characterized in that the speed of the rotor is controlled according to the sound emissions of the prime mover and/or according to the sound emissions of the working machine.

Abstract: A two-fluid nozzle of an internal mixing type in which clogging does not occur easily, excellent atomization performance can be obtained, and various application can be realized with simple constitution is provided. A constitution is such that a liquid cap body having a fluid channel formed therein and into which a supply liquid is supplied from an upstream side and an air cap body provided on a downstream portion of the liquid cap body and into which a supply gas is supplied are provided, a liquid outlet is provided on a downstream end of the liquid cap body, a gas chamber portion into which the supply gas is supplied is formed inside the air cap body, a mixed gas outlet is formed on the downstream side of the gas chamber portion, and a mortar-shaped mixed-gas expanding portion is provided immediately after the mixed gas outlet.

Abstract: The shower device according to the present invention comprises a main flow path connecting the shower hose and the shower head portion, having a central portion extending in an up-downstream direction, and guiding water from the shower hose to the shower head portion. And a main body provided to detachable a cartridge having an inner space formed therein to an outer diameter side of the central portion, and forming a secondary flow path for guiding water from the main flow path to the cartridge.

Abstract: A dip tube for a fluid pump which dip tube includes at least one frangible portion which, when intact, provides different characteristics to the dip tube than when broken, including, for example, providing for shortening of the length of the dip tube and/or providing for an inlet opening at a closed a lower end of the dip tube. The dip tube is to be inserted into a fluid containing bottle such that on insertion a distal end of the dip tube comes into engagement with a bottom wall of the reservoir with forces arising in such engagement resulting in a breaking of the frangible portion causing a change of characteristics of the dip tube.

Abstract: A water outflow control assembly includes a water inlet body, a push rod, a rotor and an elastic member. The water inlet body is provided with a valve cavity. One end of the valve cavity is provided with a push rod hole for sliding of the push rod. The push rod is provided with push blocks. The rotor is provided with tooth blocks extending toward the push rod hole and matching with the push blocks, and a retaining wall with a gap. The retaining wall is in clearance fit with an inner wall of the valve cavity, and rotation of the rotor changes a degree that the retaining wall blocks a water inlet channel. By adopting the shower head with above mentioned assembly, the water outflow control assembly can be installed through a handle hole of a shower head body of a shower head.

Abstract: A shield adapted for attachment to a wall mounted tap in order to form a protective barrier and prevent splash against the wall when the tap is in use.

Abstract: A tooling for wheel spraying reinforcement can uniformly apply a hard coating on the inner rim and the spoke back cavity of a wheel, and can effectively solve the technical problems of uneven spraying and poor roundness. The high-precision spraying of the hard coating of the wheel is realized, and the device has novel structure, advanced technology and high universality.

Abstract: A flexible sheet collects overspray and keeps spray booth environments clean, thereby reducing or eliminating dust and foreign matter from landing on wet painted surfaces which might otherwise result in a paint surface defect. The flexible sheet comprises a woven or non-woven mesh or net material having apertures or perforations that penetrate through the sheet. The sheet is impregnated with a tacky substance, such that paint overspray and dirt particles cling to the impregnated sheet. In the preferred embodiment, the tacky substance is a wax-based substance, more preferably a natural or synthetic beeswax-based substance. The material may be made from polymeric filaments of nylon or other natural or synthetic fibers, threads or strands. The flexible sheet of material may be provided in roll form for use. Method of making a tacky netting are also disclosed. The product is particularly useful in vehicle spray-booth applications.

Abstract: The invention refers to a spraying device (10) for an agricultural sprayer (100), comprising a distributor linkage (12) on which multiple dispensing elements (22) for dispensing a spray liquid are arranged, an active vibration reduction device (24) which is designed to actively reduce vibrations of the distributor linkage (12), and a dispensing quantity controller (26) which is designed to adapt the spray liquid dispensing quantity (AM) of individual, grouped or all of the dispensing elements (22) to vibrations of the distributor linkage (12).

Abstract: A sticking elimination method and structure for the water control valve of a water spraying timer. The methodology includes: open/closed state sensing step: detect the open/closed mode of the water control valve and generate and send a signal to the electronically controlled processing unit; stuck state judging step: the detecting and computing module of the processing unit judges if the state of the component has gone beyond the preset abnormal value; reverse control step: if a stuck state is judged, the valve is driven to reverse; reverse state sensing step: detect if the valve has successfully reversed and returned to the open/closed mode; repeated reverse step: if the stuck state is not eliminated, repeat the reverse till set times; automatic shutdown step: if the reverse times reach the set times and it is judged that the valve is still in the stuck state, shut down the water spraying timer.

Abstract: A device for cleaning and drying a spraying unit, the device containing: a top end and a bottom end; the top and bottom end connected to each other by a housing; the housing having an opening proximate the top end, for receiving at least a portion of a spraying unit; a first liner within the housing; a second liner within the first liner; the first liner fitting within the housing forming a space between an outside wall of the first liner and an inside wall of the housing; the second liner fitting within the first liner forming a space between an outside wall of the second liner and an inside wall of the first liner; the opening further containing an open cap, proximate the top end; the device having at least one vacuum air supply influent port, at least one drying air supply influent port and at least one solvent supply influent port, at least one vacuum air supply channel in communication with the at least one vacuum supply influent port, for supplying vacuum air to at least one vacuum air effluent port; at

Abstract: A nozzle apparatus is described in relation to dispensing colorant liquid in a paint tinting system. The nozzle apparatus comprises: a nozzle (12, 13) with a passage (14, 15) for a colorant liquid (16), the passage (14, 15) extending to an outlet for dispensing colorant liquid from the nozzle (12, 13); and an ultrasound transducer (20) for applying ultrasonic vibration to the nozzle (12, 13) and/or to liquid (16) at the nozzle outlet.

Abstract: The purpose of the present invention is to provide a sealant application nozzle and a sealant application device that can apply a suitable amount of sealant uniformly and with which rapid work can be performed. A sealant application nozzle is provided with: a porous impregnation part that can be impregnated with sealant and elastically deforms by contact with a chamfered part; a sealant supply path that supplies sealant to the impregnation part; a base part that surrounds the impregnation part such that the tip part of the impregnation part is exposed to the outside; and a retention space that is formed between the base part and the impregnation part and retains the sealant.

Abstract: Liquid product application (ceramic coatings, surface sealants) tools/medium are disclosed herein. More particularly, a liquid product applicator having an impenetrable layer of material between the absorbent textile layer, for example microfiber, and an interior substrate layers of a composite product (foam).

Abstract: A method for coating a top of a substrate with a coating solution, the method includes: supplying, before a solution film of the coating solution formed on the substrate dries, a solvent for the coating solution to a peripheral portion on the solution film of the coating solution on the substrate while rotating the substrate at a predetermined rotation speed to form a mixed layer of the coating solution and the solvent at the peripheral portion; and then, controlling a film thickness of the coating solution after drying by rotating the substrate at a rotation speed higher than the predetermined rotation speed to push the mixed layer to an outer peripheral side.

Abstract: A slot die shim for use with a slot die, the slot die shim including a first channel configured to receive a first coating, a second channel configured to receive a second coating, and a third channel configured to receive a third coating. The slot die shim simultaneously dispenses the first coating through the first channel, the second coating through the second channel, and the third coating through the third channel onto a substrate. The coatings can be applied at different flow rates and include different test reagents. A vacuum force is applied to the first, second, and third coatings to control a width and a thickness of each of the coatings and a gap or distance between the coatings. The first, second, and third coatings are placed near one another or directly in contact with one another to minimize the area required for the coatings.

Abstract: An electronic component manufacturing apparatus has a holding member for holding an electronic component body, a surface plate, a moving unit that causes the holding member and the surface plate to relatively move, and a control unit that controls the moving unit. The control unit causes the moving unit to simultaneously perform a distance changing movement for changing, by shortening or extending, the distance between an end face of each electronic component body and a surface of the surface plate, and a position changing movement for changing a two-dimensional position where the end face of the electronic component body is projected on the surface of the surface plate in such a manner that the direction in which the two-dimensional position moves in parallel with the surface of the surface plate successively varies (for example, along a circular path).

Abstract: Non-conductive films for constructing lighter than air balloons are provided. A non-conductive film may comprise multiple layers of gas barrier polymers. An outer surface printable layer and an interior heat or ultrasonically sealable layer may also be included. Each gas barrier film may comprise multiple (e.g., from 3 to approximately 75) barrier layers. A gas barrier core has a nano-layer structure. A gas barrier core may also comprise a biodegradable film or a bio-based film. A non-conductive film may comprise a metal layer for enhancing gas barrier properties. The metal layer may be discontinuous. The metal layer may be conductive and coated with an insulating top coat.

Abstract: A method of forming an ultrasonic transducer device includes bonding a membrane to seal a transducer cavity with at least a portion of a getter material layer being exposed, the getter material layer comprising a portion of a bilayer stack compatible for use in damascene processing.

Abstract: In one embodiment, a transducer comprises a first piezoelectric stack comprising a piezoelectric material; a first layer in contact with the piezoelectric stack; and a base structure beneath the first layer. The first layer has a first displacement between a first portion of the base structure and the first layer, and the first displacement is configurable by a first bias voltage received by the transducer.

Abstract: Implementations of the subject matter described herein relate to sensors including piezoelectric micromechanical ultrasonic transducer (PMUT) sensor elements and arrays thereof. The PMUT sensor elements may be switchable between a non-ultrasonic force detection mode and an ultrasonic imaging mode. A PMUT sensor element may include a diaphragm that is capable of a static displacement on application of a force and is capable of a dynamic displacement when the PMUT sensor element transmits or receives ultrasonic signals. In some implementations, a PMUT sensor element includes a two dimensional-electron gas structure on the diaphragm. The sensors may further include a sensor controller configured to switch between a non-ultrasonic force detection mode and an ultrasonic imaging mode for one or more of the PMUT sensor elements, wherein an applied force is measured in the non-ultrasonic force detection mode and wherein an object is imaged ultrasonically during the ultrasonic imaging mode.

Abstract: A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a layer of piezoelectric material that is activated and sensed by an electrode and a conductive plane layer. The conductive plane layer may be electrically connected to processing circuitry by a via that extends through the piezoelectric layer. One or more isolation trenches extend through the conductive plane layer to isolate the conductive plane layer from other conductive plane layers of adjacent PMUT devices of a PMUT array.

Abstract: A bucket mounted sifter assembly includes a ring that is positionable around a top end of a bucket. A pair of handles is each coupled to the ring for gripping. A first screen is positioned within the ring, and rocks and particulates can be positioned on the first screen. The first screen has openings therein of approximately 0.5 inches in size to facilitate the particulates to fall therethrough while inhibiting the rocks from passing therethrough for sifting the rocks. A second screen is positionable on the first screen and the second screen has openings therein of approximately 0.25 inches in size. Thus, the second screen reduces the size of material that can pass through the second and first screens. A fastener is extendable through the first and second screens when the second screen is positioned on the first screen for releasably coupling the second screen to the first screen.