A Review of Main Factors Involved in the Maturation of Oil Palm (Elaeis guineensis Jacq.) Fruit Bunches

The oil palm (Elaeis guineensis Jacq.) is a diploid perennial plant of the Arecaceae family. It is the most important plant cultivated for oil production. To ensure this production, certain optimal conditions are required: temperature, sunshine, rainfall, etc. The oil palm ensures its survival through the fruits borne on bunches located at the axis of the 17th to 20th leaves from the central stem. From pollination to the maturity of a bunch it takes about 4.5 to 6 months. Several events occur during this period: seed enlargement, weight increase, colour change, etc., but also important physiological changes: synthesis of some pigments (anthocyanin), increase in oil content correlated with the decrease in water content, etc. All of these constitute factors that can provide a better understanding of the biology of the seed. The aim of this work was to review some of the important parameters involved in the development and maturation of oil palm fruit bunches. These factors are classified into physiological, biochemical as well as environmental. The physiological parameters are color, appearance of embryo, seed weight and fruit detachment from bunches;Biochemical parameters include water content, oil content, carbohydrate, protein, mineral contents and lipase activity while temperature is the main environmental factor that affects fruit maturation. Thorough research has not yet been done at the different stages of maturation and ripening, thus a deep look into this may open up new avenues for research on early germinated oil palm seed production prior to seed dormancy.

Statistical optimization of adsorption processes for removal of 2,4-dichlorophenol by activated carbon derived from oil palm empty fruit bunches

The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced by thermal activation of activation time with 30 min at 800℃. The adsorption process conditions were determined with the statistical optimization followed by central composite design. A developed polynomial model for operating conditions of adsorption process indicated that the optimum conditions for maximum adsorption of phenolic compound were： agitation rate of 100 r/min, contact time of 8 h, initial adsorbate concentration of 250 mg/L and pH 4. Adsorption isotherms were conducted to evaluate biosorption process. Langmuir isotherm was more favorable （R^2=0.93） for removal of 2,4-dichlorophenol by the activated carbon rather than Freundlich isotherm （R^2=0.88）.

Characteristics of terahertz coherent transition radiation generated from picosecond ultrashort electron bunches

This paper presents a method of generating terahertz （THz） coherent transition radiation （CTR） from picosecond ultrashort electron bunches including single and train bunches, which are produced by a photocathode radio frequency gun. The radiation characteristics of THz CTR including formation factor and energy spectrum are analysed in detail. With the help of a 2-dimensional particle-in-cell simulation, the radiation characteristics including power, energy and magnetic field are analysed. The results show that the radiation frequency can be adjusted by tuning the repetition frequency of the train bunch and the energy can be enhanced with the train bunches.

Preliminary study on detection and cleaning of parasitic bunches

To establish a nuclear resonant scattering beamline at the High Energy Photon Source(HEPS),it is essential to develop tools for detection and cleaning of parasitic bunches,for meeting the stringent demands on bunch purity.To this end,a novel time-correlated single-photon counting system was implemented at the electron storage ring of the Beijing Electron–Positron Collider II(BEPCII).The purity deterioration process over a week-long operation was recorded by the system.In this study,the mechanism of impurity growth was analyzed by numerical methods and validated on measurements.The agreement between the experimental results and the cal-culation was fairly good.Two main sources of parasitic bunches,pre-accelerators and the Touschek scattering were confirmed.A bunch-cleaning technique,based on a sinu-soidal signal mixed with a pseudo-square wave,was also developed and implemented,and its capability to improve the bunch purity to the level of 10–7 was experimentally demonstrated.We present the experimental setup,princi-ple,and measurement results of a system for detection and cleaning of parasitic bunches.

Activated carbons derived from oil palm empty-fruit bunches: Application to environmental problems

Activated carbons derived from oil palm empty fruit bunches （EFB） were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process, Two types of activation namely; thermal activation at 300, 500 and 800℃and physical activation at 150℃ （boiling treatment） were used for the production of the activated carbons. A control （untreated EFB） was used to compare the adsorption capacity of the activated carbons produced from these processes. The results indicated that the activated carbon derived at the temperature of 800℃ showed maximum absorption capacity in the aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon at 800℃. It was observed that the adsorption capacity was higher at lower values of pH （2-3） and higher value of initial concentration of phenol （200-300 mg/L）. The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of phenol adsorption onto activated carbons were also studied to evaluate the adsorption rate. The estimated cost for production of activated carbon from EFB was shown in lower price （USD 0.50/kg of activated carbon） compared the activated carbon from other sources and processes.

The Efficiency of the Moire Technique for Three-Dimensional Measures of Grape Bunches

This study was carried out in the University of Campinas to study the three-dimensional reconstruction of grape bunches through the application of the Moire technique as an alternative and innovative method, using low-cost equipment for data acquisition. This study proposed the three-dimensional visualization of grapes and topography on Xi axes through the Moire projection technique. The artificial grapes with a 20 cm long bunch and 18.45 mm average diameter for each grape were used. A projector was used to generate a grid with light and dark lines. The grape bunch was placed on a holder, illuminated by a sinusoidal grid and photographed. After processing the images, a three-dimensional map of the fruit and topography on Xi axes were obtained. The three-dimensional fruit observation allows the visualization of the higher and lower regions of the three-dimensional configuration through a color map. This result makes it possible to obtain size and shape of the grape bunch, allowing for the process automation of product selection and classification.

Dimensional Stability Properties of Medium Density Fibreboard (MDF) from Treated Oil Palm (Elaeis guineensis) Empty Fruit Bunches (EFB) Fibres

The aim of the study was to investigate the effect of pre-treatments by using sodium hydroxide (NaOH) and acetic acid on oil palm Empty Fruit Bunch (EFB) fibres for the production of Medium Density Fibreboard (MDF). The EFB fibres were treated with chemicals in the concentration range of 0.2%, 0.4%, 0.6% and 0.8% prior to refining. Single-homogenous layer MDF with 12 mm thickness and density of 720 kg/m3 was produced. Urea-Formaldehyde (UF) was applied at 10% loading (based on dry weight of dry fibres) as a binder. The physical properties (Water Absorption (WA) and Thickness Swelling (TS)) of the produced panels were tested according to European Standard, EN 622-5:2006. The results show that types of chemical used had greater effects than concentration on the dimensional stability of the MDF. EFB fibres treated with acetic acid produced MDF with better dimensional stability compared to the MDF NaOH treated fibres. High concentration of NaOH produced poor dimensional stability in the panels.

Design and test of portable comprehensive quality non-destructive detector for grape bunches based on spectrum

Based on the analysis technology of visible/near infrared diffuse reflectance spectroscopy a portable and nondestructive detector was designed to test comprehensive quality of red globe grape bunches in the growth period.The detector included spectrum acquisition probe,spectrometer,lithium battery,halogen lamp light source,advanced RISC machines(ARM)board and peripheral circuit.Based on microsoft foundation classes(MFC)development tool,the real-time analysis and processing software of the detector was written by C++language.The optimal partial least squares regression(PLSR)detection model of multi-quality parameters was implanted into the hardware device.This paper selected the red globe grapes bunches in the growth period as the research samples,collected the visible/near infrared diffuse reflectance spectrum information,and then used the established PLSR model to detect the soluble solid content(SSC),total acid(TA)and pH of the samples to generate comprehensive quality parameter.So as to realize the nondestructive detecting of comprehensive quality of red globe grapes bunches in the growth period.In conclusion,the detector could realize real-time and non-destructive detecting of red globe grapes bunches in growth period aiming at the comprehensive quality.

Segmentation of field grape bunches via an improved pyramid scene parsing network

With the continuous expansion of wine grape planting areas,the mechanization and intelligence of grape harvesting have gradually become the future development trend.In order to guide the picking robot to pick grapes more efficiently in the vineyard,this study proposed a grape bunches segmentation method based on Pyramid Scene Parsing Network(PSPNet)deep semantic segmentation network for different varieties of grapes in the natural field environments.To this end,the Convolutional Block Attention Module(CBAM)attention mechanism and the atrous convolution were first embedded in the backbone feature extraction network of the PSPNet model to improve the feature extraction capability.Meanwhile,the proposed model also improved the PSPNet semantic segmentation model by fusing multiple feature layers(with more contextual information)extracted by the backbone network.The improved PSPNet was compared against the original PSPNet on a newly collected grape image dataset,and it was shown that the improved PSPNet model had an Intersection-over-Union(IoU)and Pixel Accuracy(PA)of 87.42%and 95.73%,respectively,implying an improvement of 4.36%and 9.95%over the original PSPNet model.The improved PSPNet was also compared against the state-of-the-art DeepLab-V3+and U-Net in terms of IoU,PA,computation efficiency and robustness,and showed promising performance.It is concluded that the improved PSPNet can quickly and accurately segment grape bunches of different varieties in the natural field environments,which provides a certain technical basis for intelligent harvesting by grape picking robots.

A new method to generate relativistic comb bunches with tunable subpicosecond spacing

We propose and analyze a scheme to produce comb bunches, i.e. a bunch consisting of micro-bunch trains, with tunable subpicosecond spacing. In the scheme, the electron beam is first deflected by a deflecting cavity which introduces a longitudinal-dependent linear transverse kick to the particles. After passing through a drift space, the transverse beam size is linearly coupled to the longitudinal position of the particle inside the beam, and a mask is placed there to tailor the beam, then the mask distribution is imprinted on the beam＇s longitudinal distribution. A quadrupole magnet and another deflecting cavity are used in the beam line to compensate the transverse angle due to the first deflecting cavity. Analysis shows that the number, length, and spacing of the trains can be controlled through the parameters of the deflecting cavity and the mask. Such electron bunch trains can be applied to an infrared free electron laser, a plasma-wakefield accelerator and a supper-radiance THz source.

Characterization of Formacell Lignin Derived from Black Liquor as a Potential Green Additive for Advanced Biocomposites

Black liquor is obtained as a by-product of the pulping process,which is used to convert biomass into pulp by removing lignin,hemicelluloses and other extractives from wood to free cellulose fibers.Lignin represents a major constituent in black liquor,with quantities varying from 20%to 30%,of which a very low share is used for manufacturing value-added products,while the rest is mainly burned for energy purposes,thus underestimating its great potential as a raw material.Therefore,it is essential to establish new isolation and extraction methods to increase lignin valorization in the development of bio-based chemicals.The aim of this research work was to determine the effect of KOH or ethanol concentration as an isolation agent on lignin yields and the chemical characteristics of lignin isolated from formacell black liquor of oil palm empty fruit bunch(OPEFB).Isolation of lignin was carried out using KOH with various concentrations ranging from 5%to 15%(w/v).Ethanol was also used to precipitate lignin from black liquor at concentrations varying from 5%to 30%(v/v).The results obtained showed that the addition of KOH solution at 12.5%and 15%concentrations resulted in better lignin yield and chemical properties of lignin,i.e.,pH values of 3.86 and 4.27,lignin yield of 12.78%and 14.95%,methoxyl content of 11.33%and 10.13%,and lignin equivalent weights of 476.25 and 427.03,respectively.Due to its phenolic structure and rich functional groups that are favorable for modifications,lignin has the potential to be used as a green additive in the development of advanced biocomposite products in various applications to replace current fossil fuel-based material,ranging from fillers,fire retardants,formaldehyde scavengers,carbon fibers,aerogels,and wood adhesives.

Impact of Progressive Pruning on Leaf Miner (Coelaenomenodera lameensis) Incidence and the Yield of Oil Palm (Elaeis guineensis) —A Case Study of Benso Oil Palm Plantation Plc, Adum Banso Estate, Ghana

The oil palm leaf miner, Coelaenomenodera lameensis, is currently the most destructive pest of oil palm in Ghana and other African oil palm growing countries, causing significant losses in fresh fruit bunch yield. Progressive pruning is an oil palm pruning method in which pruning is done at the same time as fresh fruit bunch harvesting. This study evaluated the impact of progressive pruning on leaf miner population in oil palm and how these two factors (leaf miner and progressive pruning) affect the yield of oil palm at the Benso Oil Palm Plantation Public listed company (BOPP. Plc). Five distinct blocks in the plantation were selected for observations on fronds at various ranks (33, 25, or 17) based on the degree of defoliation by counting the number of pests on leaflets at different phases of insect development. Fronds from selected plots were sampled in a Completely Randomized Design (CRD). The size of plots used for the study ranged between 19 to 45 hectares. A minimum of 78 fronds were evenly cut from each block for pest count depending on the block size. Secondary data on annual yields of fresh fruit bunches before and after the introduction of progressive pruning were also obtained from BOPP. Plc records from 2011-2020. The results from the analyzed data on leaf miner index before and after the introduction of progressive pruning showed that progressive pruning has, to a high extent (64% to 36%), reduced leaf miner populations in the plantation. Paired t-test on fresh fruit bunch yield has also revealed a significant (p < 0.001) increase in annual fresh fruit bunch yield due to progressive pruning. A regression analysis, however, revealed a lower rate of yield loss (3.05 to 2.70 tonnes) to leaf miner infestation after the introduction of progressive pruning. The study recommends progressive pruning as a key cultural practice for improving crop yields in leaf miner prone plantations.

HEPS Achieves the First Electron Beam Accelerated to 500 MeV

The first electron beam of the High Energy Photon Source(HEPS)was accelerated to 500 MeV with better than 2.5 nC of bunch charge by the Linear accelerator(Linac)on March 14,which was a key milestone of the HEPS project–HEPS beam commissioning has since begun.The HEPS Linac,with a total length of about 49 m,is an S-band normal conducting electron linear accelerator with a very high bunch charge and a large bunch charge range.As the source and first-stage accelerator of electrons,the Linac mainly comprises an electron gun,a bunching system,and a main accelerator.

Monoenergetic electron parameters in a spheroid bubble model

A reliable analytical expression for the potential of plasma waves with phase velocities near the speed of light is derived.The presented spheroid cavity model is more consistent than the previous spherical and ellipsoidal models and it explains the mono-energetic electron trajectory more accurately,especially at the relativistic region.The maximum energy of electrons is calculated and it is shown that the maximum energy of the spheroid model is less than that of the spherical model.The electron energy spectrum is also calculated and it is found that the energy distribution ratio of electrons △E/E for the spheroid model under the conditions reported here is half that of the spherical model and it is in good agreement with the experimental value in the same conditions.As a result,the quasi-mono-energetic electron output beam interacting with the laser plasma can be more appropriately described with this model.

The Use of Molecular-Sieving Materials as Ameliorant for Peat Degradation in the Tropics

Peat utilization for agriculture expansion area is commonly found extensively in tropical region during the last few decades. Most agronomical practices involve drainage resulting decomposition of organic materials and increasing drying. This study was carried out to determine the potential use of molecular-sieving materials (MPMs) as an ameliorant for peat soil targeted for reducing the potential hazard of peat degradation. A clinoptilolite-zeolite, empty fruit bunches of oil palm biochar (EFBOPB), and their combination were studied its characteristics to evaluate the ability in adsorbing water and green-house gas emission. A series of laboratory analyses were conducted to determine physicochemical and mineralogical characteristics of both materials and its combination, including elemental analyses, cation exchange capacity (CEC), pH, ore spaces, water holding capacity (WHC), and adsorption capacity for CO2, NH3, and N2. The study revealed that 100 - 150 mesh size of zeolite possesses higher values of CEC, WHC, and adsorption capacity for CO2, NH3, and N2 compared to EFBOPB, whereas the latter indicated a higher organic-C content and pore spaces. Combination of 75% (w/w) zeolite and 25% (w/w) EFBOPB showed the best composition of these two MPMs to improve WHC of peat and as consequences slowing down the firing process of the peat. Based on the gas adsorption data, it could be assumed that the mixture of MPMs studied could be considered as an effective material to reduce risk of peat from fire potential hazard and retard GHG emission.

Electron Acceleration in the Cone-shaped Extra-intense Stationary Laser Field

A technique of electron acceleration in the cone shaped stationary laser field is proposed. An electron acceleration in this laser is studied, which shows that there is no electron bunching but there exists electron capture in this laser field.

适合宽带无线网络的Bunched系统

Bunched系统由多个远端天线单元(RAU)和一个中心单元(CU)构成,可以有效地提高WiMAX等未来宽带无线网络的频谱利用率,能很好地解决热点地区覆盖问题。介绍了Bunched系统的结构,描述了其系统的特点和优点,分析了需要解决的关键技术。

Terahertz coherent transition radiation based on an ultrashort electron bunching beam

The experimental result of terahertz （THz） coherent transition radiation generated from an ultrashort electron bunching beam is reported. During this experiment, the window for THz transmission from ultrahigh vacuum to free air is tested. The compact measurement system which can simultaneously test the THz wave power and frequency is built and proofed. With the help of improved Martin-Puplett interferometer and Kramers-Krong transform, the longitudinal bunch length is measured. The results show that the peak power of THz radiation wave is more than 80 kW, and its radiation frequency is from 0.1 THz to 1.5 THz.

Removal of Cu(II), Pb(II) and Zn(II) Ions from Aqueous Solutions Using Selected Agricultural Wastes: Adsorption and Characterisation Studies

The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. The effects of solution pH and initial metal concentration on adsorption capacity were examined in batch experiments. The affinity and the adsorption capacity of DTS, CC and EFB were evaluated. The adsorption behaviour of Cu(II), Pb(II) and Zn(II) ions onto DTS, CC and EFB was described using Freundlich and Langmuir isotherm models. The separation factor (RL) analysis suggests that the removal of metal ions onto three agricultural wastes studied was favourable. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 18.42, 20.37 and 22.78 mg/g for DTS, 18.38, 37.04 and 24.39 mg/g for CC, and 26.95, 37.59 and 21.19 mg/g for EFB, respectively. The characterisation studies were carried out using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). The surface morphology of the biosorbents changed significantly following interaction with metal ions. The primary adsorption mechanism was complexation between metal ions and binding sites of biosorbents. Both hydroxyl and amine groups are the main binding sites in DTS, CC and EFB.

Development of readout electronics for bunch arrival-time monitor system at SXFEL

A bunch arrival-time monitor(BAM) system,based on electro-optical intensity modulation scheme, is under study at Shanghai Soft X-ray Free Electron Laser.The aim of the study is to achieve high-precision time measurement for minimizing bunch fluctuations. A readout electronics is developed to fulfill the requirements of the BAM system. The readout electronics is mainly composed of a signal conditioning circuit, field-programmable gate array(FPGA), mezzanine card(FMC150), and powerful FPGA carrier board. The signal conditioning circuit converts the laser pulses into electrical pulse signals using a photodiode. Thereafter, it performs splitting and low-noise amplification to achieve the best voltage sampling performance of the dual-channel analog-to-digital converter(ADC) in FMC150. The FMC150 ADC daughter card includes a 14-bit 250 Msps dual-channel high-speed ADC,a clock configuration, and a management module. The powerful FPGA carrier board is a commercial high-performance Xilinx Kintex-7 FPGA evaluation board. To achieve clock and data alignment for ADC data capture at a high sampling rate, we used ISERDES, IDELAY, and dedicated carry-in resources in the Kintex-7 FPGA. This paper presents a detailed development of the readout electronics in the BAM system and its performance.