Bottom Collector Research Articles

The Water‐Exclusion Trap (WET): A 3D printable window trap collector that prevents DNA degradation

Abstract Sampling is one of the most important and fundamental processes in field biology. Among many sampling methods in entomology, window traps have long been considered one of the most effective and standardized methods. Unfortunately, the DNA quality of samples collected by window traps is typically low due to incursion by water, mainly via rainfall. Water cannot be avoided in long‐term surveys, even with a roof, due to wind and condensation. As we move into the genomics era, this shortfall in DNA quality has become problematic for molecular biomonitoring, and solutions are urgently needed. In this study, we developed the Water‐Exclusion Trap (WET), a 3D printable long‐term storable bottom collector for window or pitfall traps. The collection medium in WETs does not dilute because water is excluded and evaporation is limited, maximizing DNA preservation. Our field tests show that the WET outperforms conventional traps in preserving DNA quality. Insect samples preserved in WETs in the field had significantly higher PCR success rates and DNA Integrity Numbers compared to conventional traps. The WET addresses a critical challenge in the use of window traps, DNA degradation caused by water intrusion, and represents a significant advancement in fieldwork for genomic research in entomology. We provide the 3D printing template of the WET, enabling immediate, free use for all. Furthermore, it can be easily customized for different environments and purposes, and can be adapted to a variety of other traps, including pitfall traps, funnel traps and more.

Purification of biodiesel from crude palm oil using multistage portable fixed bed adsorber

Crude biodiesel needs to go through purification process, to meet international biodiesel specifications.. The widely used adsorption column is in the form of a fixed bed column, where the contents of the column are stacked in a mess. This makes the adsorbent difficult to clean and fill, and irregular adsorbent accumulation can hinder the flow of the fluid to be purified. In this study, an adsorption column with a portable circulation system used to observe the influence of circulation and adsorption level on the purity of biodiesel. Main equipment of this research is a portable adsorption biodiesel purification device. The column consists of: top distributor, packed bed and bottom collector. The tool is made of 3D printed polymer material. At the bottom of the tower there is a buffer tank and a pump for circulating the biodiesel to be purified. The results showed that some analytical parameters based on the results of t-test, namely: density, acid value, saponification and yellowish-blue tendency, there are significant differences between the results before and after purification. For all the parameters analyzed in this study, the number of stages and fluid circulation gave significantly different results. The results of methyl ester analysis confirmed this, where the more cycles in the column, the higher the methyl ester peak produced. As number of cycles in the adsorption column increases, peak area of the methyl ester produced becomes wider, which can be explained by the ability of column and its packing materials to filter impurities present in column.

Portable Circulating Adsorption Column Design for Seawater Purification

Seawater is one of the largest natural resources and abundant in Indonesia, which contains salt, metals and mycobacteria. Even though the amount is abundant, its utilization is still not widespread, such as to be used as clean water or drinking water. The use of adsorbents aims to adsorb impurities in the fluid. The adsorption column that is widely used is in the form of a fixed-bed column with messy stacked filling. This makes it difficult to clean and fill the adsorbent, besides the irregular pile of adsorbents will hinder the flow process of the purified fluid. The research product is a circulating portable adsorption column design consisting of 3 parts, namely: top distributor, packing bed, and bottom collector. The principle of the three parts is like a puzzle where the number of packing beds can be adjusted according to the purification needs. The three parts are connected with threads so that they can be disassembled as desired. It is hoped that this product can meet the needs of adsorption-based purification that is easy, inexpensive, and can be customized according to various types of adsorbents. The design of this product can be duplicated for other adsorption purification processes, such as purification of bioethanol, wastewater, and biodiesel.

Study of a Method to Effectively Remove Char Byproduct Generated from Fast Pyrolysis of Lignocellulosic Biomass in a Bubbling Fluidized Bed Reactor

A critical issue in the design of bubbling fluidized bed reactors for biomass fast pyrolysis is to maintain the bed at a constant level to ensure stable operation. In this work, a bubbling fluidized bed reactor was investigated to deal with this issue. The reactor consists of inner and outer tubes and enables in situ control of the fluidized-bed level in the inner-tube reactor with a mechanical method during biomass fast pyrolysis. The significant fraction of biochar produced from the fast pyrolysis in the inner-tube reactor was automatically removed through the annulus between the inner and outer tubes. The effect of pyrolysis temperature (426–528 °C) and feeding rate (0.8–1.8 kg/h) on the yield and characteristics of bio-oil, biochar, and gaseous products were examined at a 15 L/min nitrogen carrier gas flow rate for wood sawdust with a 0.5–1.0 mm particle size range as a feed. The bio-oil reached a maximum yield of 62.4 wt% on a dry basis at 440 °C, and then slowly decreased with increasing temperature. At least 79 wt% of bio-char byproduct was removed through the annulus and was found in the reactor bottom collector. The GC-MS analysis found phenolics to be more than 40% of the bio-oil products.

Centrifugal spun osteoconductive ultrafine fibrous mat as a scaffold for bone regeneration

Centrifugal spinning (C-Spin) have engrossed the interest of researchers in global community in recent past. In C- spin technology, polymeric ultrafine fibers were produced by applying centrifugal force to the polymeric solution kept in reservoir provided with a narrow orifice. Once the applied centrifugal force overcomes surface tension of the polymeric solution, fibers were ejected from the orifice and collected in bottom collector. Owing to its salient features such as high production rate, highly safe to the users and controlled fiber alignment, it can overcome the limitations of currently existing techniques. In the present study, hydroxy apatite (HA) and clove extract incorporated Poly lactic acid (PLA) ultrafine fibers were produced by in-house built centrifugal spinning. The developed fibers were aligned and the average fiber diameter ranged from 900 to 1200 nm. EDX analysis confirmed the successful incorporation of HA. Incorporation of clove extract was further confirmed by FITR results. Blood compatibility assay results revealed that all mats were highly haemocompatible and showed % haemolysis below 1. PLA/1.5% HA/Clove extract incorporated scaffolds showed better cell proliferation and osteogenic differential potential was confirmed by alizarin red staining and alkaline phosphatase activity.

Use of experimental and numerical simulation methods for rational design of the air cooling apparatus for lubrication systems of compressors

The objective of the present work was to study heat and hydraulic parameters of an air cooling apparatus of oil (ACAO), whose geometry of its flow-through part is changed to decrease hydraulic losses in its air conduit and to increase the cooling efficiency of oil. Using numerical simulation methods of heat transfer, we have developed and tested the computational techniques applied in a wide class of heat exchange apparatuses, including those consisting of the sections of finned flat tubes manufactured by extrusion with subsequent deforming cutting. We have proposed to make a finned part of a heat-exchange surface in the form of porous inserts. This has allowed us to reduce numerical simulation equipment requirements and to decrease computational time. Predicted results well agree with experimental data; their analysis shows that the calculated value of thermal performance of the oil cooler due to the revealed construction drawbacks of the air conduit is by 19 % less than that of the designed one. Based on the results of the numerical simulation studies, a number of recommendations have been made how to improve the layout inside the air cooling apparatus for oil in order to enhance its thermal performance and aerodynamic quality. In particular, we have proposed to mount new fan blades to enhance its performance; to change the construction of the air outlet valve by taking away a baffle that partially overshadows the exit area of the bottom fan; to modify the shape of the bottom collector of the oil cooler in order to make a uniform velocity profile at the entrance of cooling sections. Connecting in series heat exchange sections may be a perspective engineering decision. The outcomes of all proposed engineering decisions can be assessed by numerical simulation methods that will allow us not to design expensive equipment.

Microplastics occurrence and spatial distribution in seawater and sediment of Haikou Bay in the northern South China Sea

This study investigated microplastics (MPs) pollution in Haikou Bay in the northern South China Sea (SCS). Eight sampling sites were selected on the basis of their functions as hotel-intensive areas, public beaches, harbors, municipal discharge sites, and public waters. A total of 1053 putative plastic particles of which 1019 were from seawater and 34 from sediment were collected using 333 μm nylon Neuston nets and a bottom collector, respectively. The results showed that the abundance of MPs ranged from 0.26 to 0.84 items/m3 (hereafter defined as n/m3) in the surface water and 0.66 ± 0.58 n/50 g (d.w.)–17.00 ± 6.56 n/50 g (d.w.) in the sediment of Haikou Bay. For the surface seawater samples, the predominant MPs were fibers (83.12%) in rayon (52.73%). For the sediment samples, MPs were predominantly in fibers (67.65%), while PE (28.41%), polyolefin (25.50%), rayon (23.53%) were frequently detected. MPs are widely found in coastal seawater and sediment, but with different abundance in different functional areas. A higher abundance of MPs was found in the seawaters of public beaches and sediments of sewage discharge ditches. Our results highlight the occurrence of MPs in Haikou Bay, and we also offer field study results for the evaluation of environmental risks posed by MPs in the northern SCS.

Liquid Capacitor Based on Hafnium Oxide

In this work, we synthesize Hafnium (IV) oxide (HfO2) ink from hafnium chloride (HfCl4) powder assisted with deionized water. The poly acrylic acid (PAA) is used as surfactant to decrease the surface tension. Conversion of HfCl4 into HfO2 was detected by Raman spectroscopy and energy dispersive X-ray spectroscopy (EDS) characterization techniques. This proposed ink can be easily synthesized at a low temperature. Using the synthesis ink, a liquid capacitor is proposed, which is tested for electrochemical analysis. Indium tin oxide (ITO) coated PET is used as bottom and top current collector electrode, polydimethylsiloxane (PDMS) mold is used as separator, and HfO2 ink is used as aqueous electrolyte. Liquid capacitor is also tested on different bending diameters using bending machine from flat down to 10 mm bending curvature, which shows a stable capacitor function.

Experimental and theoretical investigation on a radiative flat heat pipe heat exchanger

Abstract Large amounts of heat are rejected by hot steel when it is cooling during the manufacturing process. In an earlier investigation a flat heat pipe (FHP) was constructed and tested in a factory for recovering this heat loss from steel wires by radiation and convection. In this paper, the performance of the FHP was examined by testing it at different configurations. In parallel a theoretical study was conducted. The FHP consisted of 14 stainless steel tubes connected by a bottom collector and a shell and tube condenser top header. The heat transfer area was increased by attaching a stainless steel at the back of the tubes. The effect of the back panel on heat recovery was examined by testing the FHP with the back panel and without it. In addition, the effects of the emissivity and absorptivity of the FHP surface on the thermal performance were investigated by testing the FHP both painted with high temperature black paint and with it unpainted. A theoretical modelling tool based on thermal network modelling was built. The theoretical prediction of the thermal performance of the FHP represented by the amount of heat recovery was compared with the experimental findings. The results of the FHP thermal performance were compared for four cases. The results indicated that heat recovery was greatly increased by painting the surface with thermal black paint. Furthermore, the back panel has a significant influence on the magnitude of heat recovery.

Experimental simulation of downward molten material relocation by jet ablation of structures and fuel coolant interaction in a fast reactor

In the remote chance of a core melt-down accident in a fast reactor, the molten corium from the fuel subassembly can come out in the form of a liquid jet due to the prevailing transient pressure. This high temperature jet is capable of causing local breaches on horizontal solid structures such as the grid plate with which they come into contact inside the main vessel. After penetration through the plates, the molten jet undergoes fragmentation in the bulk coolant available below the grid plate, in the lower plenum and settles on the core catcher. Experimental investigation of molten material relocation in the downward direction is carried out with a wood's metal jet impinging on a pair of solid wood's metal plates. The wood's metal alloy is heated electrically to about 300 °C inside the melt chamber and released through a nozzle to impinge on the dry plates mounted on rigid supports and allowed to pierce through the plates. The jet then gets quenched in bulk water contained in the experimental vessel. The trajectory of vertical jet impinging on the set of two parallel horizontal plates is captured using a high speed camera. Thermocouples are placed on the top and bottom surface of the plates to assess the temperature evolution. The breach area formed on the plates by the hot molten jet is assessed from the experiments. The initial pressure of the liquid jet is varied from 0 bar to 2 bar gauge pressure. The mass of the debris collected on the breached wood's metal target plates and the stainless steel collector plate gives evidence that the entire molten mass of jet does not reach the bottom collector plate but gets distributed on all the plates. The particle size distribution is obtained for the fragmented wood's metal debris settled on the collector plate. It is observed that the mass median diameter of the fragmented particles and porosity of the debris bed decreases as the jet release pressure is increased. An empirical correlation between the particle size represented by the mass median diameter and the initial pressure of the jet is obtained.

Development of the flowing liquid lithium limiter for EAST tokamak

Lithium coating technology and liquid lithium limiter have been applied on HT-7 tokamak and many significant results were obtained. The study of exploring lithium as potential plasma facing material is being carried out on EAST tokamak. A flowing liquid lithium (FLiLi) limiter has been successfully tested in the EAST in 2014, and the in-vessel electromagnetic (EM) pump was validated to make liquid lithium circulate from the bottom collector to the distributor of the limiter, which realized the FLiLi operated under steady-state and also drastically reduced the total amount of lithium used in the experiment. To adapt to the plasma shape during discharge, the limiter can be moved along the guide rail into vacuum vessel to meet various plasma scenarios by the driving system. During the operation, the lithium can be easily controlled by adjusting the current of EM pump and the <0.1mm thickness of lithium film and a mass flow rate ∼2cm3/s were achieved. However, some problems were also exposed, which require improvement for the next generation of limiter. The current design, manufacturing and the latest results of the new EAST FLiLi limiter were introduced in this paper.

Comparison of the species richness and abundance of Cerambycidae (Coleoptera) and Scolytinae (Coleoptera: Curculionidae) captured in aerial malaise traps with and without a bottom collector

AbstractMethods for detection and monitoring invasive insect species are continually being refined and developed. Detecting invasive pests early can improve chances of eradication or management of populations. Aerial malaise traps are successfully used in monitoring for insects such as longhorned beetles (Coleoptera: Cerambycidae) and bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae). These traps have both a top and bottom collecting cup. The bottom portion of these traps leading to the collection cup collects canopy litter at a high rate, greatly increasing time required to sort through and possibly affecting the diversity and abundance of insects captured. Traps with top and bottom collecting cups were compared with traps with only top collecting cups to determine the effect on species richness and abundance of cerambycids and scolytines. There was no significant difference in species richness and abundance of cerambycids, and abundance of scolytines, however species richness of scolytines was significantly higher in top/bottom traps. We conclude that removing the bottoms from aerial malaise traps would benefit monitoring programmes that use this type of trap in combination with funnel traps, albeit with the potential loss of information on scolytine richness.

High-performance vertical polymer nanorod transistors based on air-stable conjugated polymer

A vertical polymer nanorod transistor was realized based on an air-stable poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] with a high highest occupied molecular orbital energy level. The influence of the work function of the emitter on the performances of the space-charge-limited transistor was investigated. When MoO3/Al was used as the top emitter and indium tin oxide was used as the bottom collector, the operating voltage of 0.6 V, the on/off current ratio of 4 × 104, and the switching swing of 105 mV/decade were achieved. A low-power-consumption inverter was also demonstrated.

Effects of water depth on survival and growth of Argopecten purpuratus (Lamarck, 1819) spat in northern Chile

Collection and suspended culture of Argopecten purpuratus spat in Japanese-type collectors was undertaken in the Rinconada Marine Reserve (Antofagasta, Chile) to determine growth variations between surface and bottom waters. Scallop spat was collected at 16-m depth and grown at 1- and 16-m depths. An initial settlement of ca. 13,000 post-larvae per bottom collector (2 cohorts) was observed on 3 February 2001. Two new cohorts settled in bottom collectors on 3 March, while no spat settlement occurred in surface collectors. The four cohorts exhibited substantial and different mortality rates over the study period, depending on the cohort and on-growing depth. The first and second cohorts exhibited mortality rates of 80.3 and 53.1% in bottom collectors, respectively, versus 29 and 43.6% in surface structures. The third and fourth cohorts exhibited mortality rates of 21.4 and 59.7% in bottom collectors, respectively. Mean shell height of scallop spat after 88 days of culture was 6.46 mm for the first cohort and 4.37 mm for the second cohort in bottom collectors, versus 10.33 and 7.31 mm in surface collectors, respectively. Mean post-larval growth rate in bottom collectors (86 μm day−1) was significantly lower than growth rate in surface collectors (146 μm day−1). Factors explaining the depth-related mortality and growth rates are discussed to improve scallop culture in the Reserve. It was concluded from the results that culture improvement in Antofagasta Bay would require collecting spat in bottom waters and raising it near the surface during initial cultivation stages.

Bottom 컬렉터와 단일 금속층 구조로 설계된 SiGe HBT의 전기적 특성

This paper presents the electrical properties of SiGe HBTs designed with bottom collector and single metal layer structure for RF power amplifier. Base layer was formed with graded-SiGe/Si structures and the collector place to the bottom of the device. Bottom collector and single metal layer structures could significantly simplify the fabrication process. We studied about the influence of SiGe base thickness, number of emitter fingers and temperature dependence <TEX>$(<200^{\circ}C)$</TEX> on electrical properties. The feasible application in <TEX>$1{\sim}2GHz$</TEX> frequency from measured data <TEX>$BV_{CEO}{\sim}10V,\;f_T{\sim}14GHz,\;{\beta}{\simeq}110,\;NF{\sim}1dB$</TEX> using packaged SiGe HBTs. We will discuss the temperature dependent current flow through the e-b, b-c junctions to understand stability and performance of the device.

Design and Fabrication of Charge-Injection-Controlled Organic Transistors

A novel device structure called a “mesa-type” was designed and fabricated for a charge-injection-controlled organic transistor (CICT), which is a three-terminal vertical transistor having its third striped metal base electrode in the organic semiconductor film. Using lithography, a mesa structure of insulating SiN was provided beneath the stripe base electrode to diminish current leakage between the base and the bottom collector electrodes. The SiN insulating layer efficiently suppressed current leakage, and clear modulation of the collector current was observed. The choice of Pt for the base electrode metal enables an amplification factor (hFE) as high as 700 to be achieved as expected from its driving mechanism. The lithography also enabled us to examine the electrode stripe pitch dependence, which revealed that a finer pitch stripe allows larger current modulation.

Parametric studies of passive/active solar stills by using modified convective mass transfer relations

SYNOPSIS In the present work, the effects of design parameters—namely water depth, absorptivity of basin liner and water mass, bottom insulation thickness and collector area for passive and active solar still—have been studied by using two sets of values of the constants C and n, by using inner and outer glass cover temperatures of the solar stills for a typical day under Delhi climatic conditions. The studies have been based on the basic energy balance equations of different components of passive and active solar stills taking into account modified values of C and n for convective mass transfer for both the systems. The results obtained in the present case are in accordance with the results reported earlier.

Detachment of polystyrene particles from collector surfaces by surface tension forces induced by air-bubble passage through a parallel plate flow chamber

By allowing an air-bubble to pass through a parallel plate flow chamber with negatively charged, colloidal polystyrene particles adhering to the bottom collector plate of the chamber, the detachment of adhering particles stimulated by surface tension forces induced by the passage of a liquid-air interface was quantified. The detachment forces originating from the passing interface were calculated to range from 10-9 to 10-7 N and stimulated detachment of a major proportion of the adhering polystyrene particles, regardless of whether a negatively charged, hydrophilic glass or a hydrophobic, dimethyldichlorosilane-coated glass, or a positively charged, 3-(2-aminoethylamino)propyldimethoxysilane-coated glass collector surface was used. Also, aging of the adhesional bonds between the collector surfaces and the adhering particles up to 72 h or variation of the ionic strength of the particle suspension medium, which was a potassium nitrate solution (10-100 mM), did not prevent detachment of adhering polystyrene particles from the collector surfaces. Assuming that in the case of repulsive electrostatic conditions the polystyrene particles adhered through secondary minimum DLVO interactions, it was calculated that the adhesion force per particle ranged between 10-14 and 10-12 N, which is several orders of magnitude insufficient to withstand the detachment force exerted by the passing liquid-air interface. In the case of attractive electrostatic conditions, the DLVO theory does not yield a secondary interaction minimum and an adhesion force was calculated by assuming that the polymer surface structures on the polystyrene particles kept the adhering particles at a distance of 5 nm from the collector surfaces, corresponding to an adhesion force of 10-11-10-10 N. Even when the assumption is made that the polystyrene particles can approach the collector surfaces up to the minimal separation distance between two interacting surfaces of 1.57 Å, an adhesion force of 10-8 N results, which is still of the same order of magnitude as the detachment force originating from the passing liquid-air interface. In summary, this study demonstrates the huge potential of surface tension forces for particle removal and, at the same time, is intended to be a warning for erroneous enumeration of colloidal particles adhering to collector surfaces after 'slight rinsing', 'dipping', or other manipulations said to remove loosely adhering particles.

Experiments with scale models of oil collectors for subsea well blowouts — Part II

A previous paper of the same title indicated the feasibility of the collection of oil by an open bottom collector above a blowout with a marine riser above the collector; the whole collection system being driven by gas lift from the blowout gas. That paper was based on small-scale laboratory experiments and it identified the salient dimensionless parameters governing those experiments. This paper describes laboratory experiments on a refinement of the collection system and also describes the results of intermediate scale experiments. The length scale of these experiments was about four times greater than laboratory scale and about one-fourth of full scale. Generally, the intermediate scale results are consistent with the laboratory predictions. Furthermore, two scale-dependent parameters have been identified. The effects of these have been included in an analysis of the results.