Split Block Research Articles

Use of Rice Straw Mixed Ammonium, Biochar and Compost for Improving Productivity of a Sandy Soil and the Response of Wheat

This laboratory and field experiment were to assess the use of rice straw (RS); biochar rice straw- compost (BRS); rice straw- ammonium (RSN) and compost (ST) at 0, 12.5 and 25 Mg ha-1 on the development of wheat plants and improve a sandy soil's productivity. In winter seasons of 2017/2018 – 2018/2019 at the Ismailia Agricultural Research Station. In laboratory experiment soil treatments incubation and studied OC%, SP, FC, PWP and AW. In field experiment i.e. yield, yield components, N, K and P, pH, ECe and bulk density at ripeness's stage, times application before sowing (Ap1) and with sowing (Ap2) on wheat and study design a split block. Results the end of incubation period, losses of OC% about 21.2, 7, 20.6 and 32.1% due to 25 Mg ha-1 for RS, BRS, RSN and ST respectively, we found a positive effect of rice straw and compost on SP, FC, PWP and AW. In field experiment the highest relative increase over control due to 25 Mg ha-1 BRS, RSN and ST at Ap1 for plant height were 36.58, 68.95 and 74.73 % where dry weight/plant were 35.00 48.44 and 69.06 %, grain yield were 45.13, 58.70 and 69.32%. 100 seed weight and N K P content significant affected by BRS, RSN and ST respectively. Soil available N, K and P due to all organic treatments. Soil EC was improved by RSN and ST, addition of ST impact on pH and bulk density was slightly reduced, but BRS was due to a slight increase.

Nerve Blocks Prior to Microfocused Ultrasound Treatment are Safe and Reduce Patient Discomfort.

Microfocused ultrasound with visualization has become one of the more popular nonsurgical facial rejuvenation therapies available. Although the treatment has gained wide acceptance, providing adequate pain relief during the procedure can be challenging. The aim of this study was to test our hypothesis that nerve blocks prior to treatment would be well tolerated and significantly reduce patient discomfort. Subjects undergoing microfocused ultrasound were offered the choice of participating in a split face nerve block, bilateral block, or a control group. Nerves targeted included infraorbital, supratrochlear, supraorbital, zygomaticofrontal, mental, great auricular, and cervical plexus. Pain assessment was based on a 10-point Wong-Backer FACES Pain score. A total of 65 patients were included in the study: 28 in the split face group, 19 in the bilateral block group, and 18 without a block. The mean [standard deviation] pain score of the bilateral block cohort was 3.9 [1.2], and that of the control group was 5.1 [1.7] (P = 0.001). Patients in the split face cohort reported a higher pain score on the unblocked side of the face (7.5 [1.3]) than on the blocked side (2.9 [1.0]) (P < 0.001). The mean pain score for local anesthetic injection was 2.7 and 1.4 for the split face and the bilateral groups, respectively. There were no adverse events. Nerve blocks are well tolerated and significantly improve patient comfort during microfocused ultrasound treatment without compromising outcomes or increasing adverse events.

EFFECTS OF SEEDING PATTERN AND HARVEST DATE OF PERSIAN CLOVER AND ANNUAL RYEGRASS ON HAY YIELD AND QUALITY IN A MEDITERRANEAN ENVIRONMENT

This study was carried out at Experimental fields of Ege University Faculty of Agriculture Bornova/Izmir/Turkey, during the years of 2012-2014. Three different harvest dates (Early Spring, Mid Spring and Late Spring) and mixture rates (100+0%, 80+20%, 60+40%, 40+60%, 20+80% and 0+100%, respectively) of Persian clover (Trifolium resupinatum) with annual ryegrass (Lolium multiflorum) were tested. The experiment was arranged in a split block design with three replications. As the average of 2 years results, highest yield were recorded in sole Persian clover sown as catch crop and harvested in late spring under Mediterrenean climatic conditions. The data also indicated that pure Persian cover sowing provided the highest green matter, dry matter and crude protein yields, being 36.04 t ha-1, 5.61 t ha-1 and 89 kg ha-1, respectively. Legume ratio, NDF and ADF concentrations increased by advancing harvest dates.

SLA-Printed 3-D Waveguide Paths for E-Band Using Electroless Silver Plating

This paper proposes a fabrication approach for 3-D printed waveguide paths based on a combination of an optimized electroless silver plating process with a waveguide-specific design rule for general metal plating by introducing large-scale non-radiating slots into the broad and narrow waveguide walls with a periodicity shorter than a quarter of the guided wavelength. Experimental fabrication of straight sections of the proposed slotted waveguide with various gap dimensions yields an optimum gap size as a result of a tradeoff between silver plating quality and leakage losses through the sidewall gaps. Moreover, a successful practical application of the proposed approach is presented in terms of a 3-D printed multiple bend waveguide interconnect in three different space dimensions, which imposes a complex task for conventional manufacturing techniques due to the need of multiple cutting planes for split block assembly. The proposed approach has the benefits of low cost, moderate handling effort, and independence of the concrete geometry to manufacture, making it, therefore, especially interesting for distribution and feeding networks in the context of rapid prototyping, automotive, and space-related applications.

A Full WR-3 Band and Low-Loss 90° Waveguide Twist Based on CNC

Modern terahertz (THz) receivers used in radio astronomy are aimed at developing multipixel instruments, in which the polarization twists are often required. In this article, an all-in-one and low-loss 90° waveguide twist is developed for working over the full WR-3 band. A square waveguide junction with a doubler-corner-cut is integrated between the H -plane and E -plane waveguides to provide 90° polarization rotating. All the vertical corners are fillet to comply with the fabrication constraints of the current computer numerical control (CNC) machining. The prototype integrated with a twist section of one-fourth wavelength thickness and two straight waveguides with total 12 mm length is processed through means of split block. Measured results exhibit a low insertion loss of 0.4 dB and better than 25 dB return loss across the entire WR-3 band, which are all in good agreement with the simulations. Such excellent performance is highlighted comparing with the reported THz waveguide twists, which indicates that this compact design is well suited for the delicate CNC-machining restrictions in the THz band.

Enhanced Feature Extraction for Ship Detection from Multi-Resolution and Multi-Scene Synthetic Aperture Radar (SAR) Images

Independent of daylight and weather conditions, synthetic aperture radar (SAR) images have been widely used for ship monitoring. The traditional methods for SAR ship detection are highly dependent on the statistical models of sea clutter or some predefined thresholds, and generally require a multi-step operation, which results in time-consuming and less robust ship detection. Recently, deep learning algorithms have found wide applications in ship detection from SAR images. However, due to the multi-resolution imaging mode and complex background, it is hard for the network to extract representative SAR target features, which limits the ship detection performance. In order to enhance the feature extraction ability of the network, three improvement techniques have been developed. Firstly, multi-level sparse optimization of SAR image is carried out to handle clutters and sidelobes so as to enhance the discrimination of the features of SAR images. Secondly, we hereby propose a novel split convolution block (SCB) to enhance the feature representation of small targets, which divides the SAR images into smaller sub-images as the input of the network. Finally, a spatial attention block (SAB) is embedded in the feature pyramid network (FPN) to reduce the loss of spatial information, during the dimensionality reduction process. In this paper, experiments on the multi-resolution SAR images of GaoFen-3 and Sentinel-1 under complex backgrounds are carried out and the results verify the effectiveness of SCB and SAB. The comparison results also show that the proposed method is superior to several state-of-the-art object detection algorithms.

Bioprospecting Elicitation with Gamma Irradiation Combine with Chitosan to Enhance, Yield Production, Bioactive Secondary Metabolites and Antioxidant Activity for Saffron

Saffron (Crocus sativus L.) corms were subjected to gamma irradiation doses; 0,5,15,25 Gy (G1-4) then were planted as annual crop in complete randomized split block design with three replicates. The resultant plants 3 months aged and every month up tile before flowering, were vegitatively sprayed with chitosan solution; 0,50,100,200 mg/L concentrations. Data (C1-4) for growth and yield traits were recorded and subjected to statistic ANDVA, revealed that individual G2, G3 as well as C2, C3, C4 performed positive significant impact on growth traits (plant height, flowers fresh weight, number of flowers, fresh and dry weight of flowers m2) that cause to significant positive impacts in yield traits (main saffron stigmas yield /ha, second medicine – therapeutic metabolites (crocin, picrocrocin, safronal), antioxidant activity and secondary by – product, corms yield/ ha) whilst, G4 attained significant negative impacts in growth and yield traits. Combine applications (G2 C2, G2C3, G2C4), (G3C2, G3C3, G3C4) achieved significant synergistic positive impacts on growth and yield traits. Aside (G4C2, G4C3, G4C4) actuated only significant positive impacts on growth and yield traits and quality, that warrant C2-4 overcoming significant impacts for G4. Overall, results strongly manifest G and /or C reliable strategy, in vivo to enhance main saffron stigmas yield, secondary metabolite (crocin, pircorcrocin, Safronal) and antioxidant activity for saffron plants.

The Growth of Tiwai (Eleutherine Americana L. Merr.) Under Different Forest Tree Stands in Agroforestry System

Agroforestry is a method and system of land management involving the simultaneous cultivation of farm crops and trees Land use under forest stands in the community has not been optimal. This research aims to study the growth, yield and qualitatively secondary metabolite content and find the best microclimate based on stand of different forest trees of Tiwai (Eleutherine americana L. Merr.). The research was carried out at research field of Agrotechnology Innovation Centre at Kalitirto, Berbah, Sleman, Yogyakarta and laboratory of agriculture production, Institute of Agriculture “INTAN” Yogyakarta. Treatments are combinations of forest tree stand i.e. gaharu, teak, mahogany, and control, and plant spacing factors i.e. 25 x 20 cm and 20 x 20 cm, and arranged in split block design with 3 replications. Plant height, leaf numbers, bulb weight and productivity were observed and analyzed statistically using analysis of variance approach. The treatment effects are studied by mean comparisons using Duncan Multiple Range Test with α = 5%. Qualitative data such as flavonoid content were descriptively analyzed. The result showed that there are statistically different growth and yield of Tiwai grown under forest tree stands. Tiwai which was grown under teak and gaharu with density 20 x 20 cm yielded similar productivity with control which is 271 – 331 g/m2 and equal to 578 – 883 kg boulbs/ha. There is different brewed colors from dark red to deep purplish Red. Types of tiwai secondary metabolite were dependent upon tree stands. At control, and under mahogany and gaharu, more apigenin was observed, whereas kaempferol and lutenoid were found under teak and gaharu. The tiwai cultivation under tree stands probably provided benefit with the 1.5 B/C ratio in the agroforestry system.

Latex quality and yield parameters of Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. clone PB 260 for different tapping and stimulant application frequencies

Tapping and stimulant applications are an attempt to increase latex yield. A combination of stimulants with low intensity tapping systems was expected to reduce tapping costs. In addition, it was necessary to regulate the stimulant application frequency based on type and potential clone production. The objective was to determine the effect on physiological parameters and latex yield of Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. clone PB 260 for different tapping and stimulant application frequencies. The study design was split block in randomized complete block plots with three replicates and two factors. The main plot was the tapping system consisting of four levels: quarter-spiral downward tapping (S/4 d3), quarter-spiral upward tapping (S/4U d3), half-spiral downward tapping (S/2 d3), and half-spiral upward tapping (S/2U d3). The subplots were four stimulant application frequencies consisting of ethephon 2.5% applied once every 15 d (ET 15d) and gas stimulant (equal to ± 100% ethylene) applied once every 9 d (ETG 9d), once every 18 d (ETG 18d), and once every 27 d (ETG 27d). The highest sucrose levels (3.62 mM) were obtained in S/2 d3 and ET/15d combination. The highest inorganic P content (27.68 mM) was in S/2 d3 and ETG/18d. The highest yield (2418.53 kg ha-1 yr-1) was in S/4d3 and ETG/18d. The tapping system S/4d3 and ETG/18d combination was able to increase production by 102.26% compared with the conventional tapping system (S/2 d3 and ET/15d). After the 1-yr trial, all treatments showed 0.47 to 0.54 mM thiol content, which indicated that plants did not experience over-exploitation stress

Rate Distortion Performance of Motion Estimation for High Efficiency Video Coding

The contemporary coding standard for video is High Efficiency Video Coding Standard (HEVC). It’s introduced by ITU-T (International Telegraph Union) and Joint Collaborative Team on Video Coding (JCT-VC). HEVC attains the requirement of video storage and transmission with high resolution. Although it requires the high amount of computational complexity. Motion Vectors are determined with motion estimation analysis; it is implemented with different types of algorithm. In this paper, Motion Estimation Process is implementing with the content split block search algorithm. It improves Peak Signal Noise Ratio (PSNR) than to the existing algorithms. The Objective evaluation has been performed with various video sequences such as BQ Terrace and also improved PSNR.

96 Impact of potassium application and harvest regime in alfalfa yield, forage quality and stand persistence in South Georgia

Abstract Potassium fertilization and harvest timing can both impact stand life of alfalfa (Medicago sativa L.). In the Southeast, high temperatures and humidity often influence harvest timing and fertilization. Current nutrient management and harvest recommendations are generated from research conducted in northern climates with different varieties. The objective of this trial is to determine the impact of potassium fertilization and harvest regime on stand persistence, forage yield, and quality of ‘Bulldog 805’ alfalfa in the Southeast. This study was conducted at the Coastal Plain Experiment Station in Tifton, GA, on a two-year-old stand of ‘Bulldog 805’ alfalfa planted fall 2015. Plots were randomly assigned using a split block design. Main plots were harvest treatment: bud, and 10, 30 and 50% bloom stage. Plots were subdivided to examine K fertilization at rates: 0, 67, 101, 134 and 168 kg/ha, split 3 times throughout the season. Plots were visually assessed each harvest to determine ground cover and percent bloom. Fifty shoots were collected to evaluate leaf:stem and mass:shoot ratio, and yield was determined through harvest using a Swift forage harvester. Grab samples were collected for nutritional analysis using near-infrared reflectance spectroscopy. Data was analyzed using the PROC GLIMMIX of SAS with repeated measures analysis option at a= 0.05. Leaf:stem ratio was not significant for all main effects (P &gt; 0.46). Harvest treatment had an effect on yield, with 10% bloom greater than bud stage (1,321 kg/ha and 1,104 kg/ha, respectively; P = 0.04). Crude protein levels were the greatest in bud stage and lowest with 50% bloom (22.8% and 21.2%; P &lt; 0.01). Total digestible nutrients were greater in bud and 10% bloom compared to 30% and 50% (65% and 63%, respectively; P &lt; 0.01). Potassium application and harvest regime can impact alfalfa growth. Funding for this project was provided by USDA-NIFA-AFRP grant #2016-70005-25653.

4 Impact of potassium application and harvest regime in alfalfa yield, forage quality and stand persistence in South Georgia

Abstract Potassium fertilization and harvest timing can both impact stand life of alfalfa (Medicago sativa L.). In the Southeast, high temperatures and humidity often influence harvest timing and fertilization. Current nutrient management and harvest recommendations are generated from research conducted in northern climates with different varieties. The objective of this trial is to determine the impact of potassium fertilization and harvest regime on stand persistence, forage yield, and quality of ‘Bulldog 805’ alfalfa in the Southeast. This study was conducted at the Coastal Plain Experiment Station in Tifton, GA, on a two-year-old stand of ‘Bulldog 805’ alfalfa planted fall 2015. Plots were randomly assigned using a split block design. Main plots were harvest treatment: bud, and 10, 30, and 50% bloom stage. Plots were subdivided to examine K fertilization at rates: 0, 67, 101, 134, and 168 kg/ha, split 3 times throughout the season. Plots were visually assessed each harvest to determine ground cover and percent bloom. Fifty shoots were collected to evaluate leaf:stem and mass:shoot ratio, and yield was determined through harvest using a Swift forage harvester. Grab samples were collected for nutritional analysis using near-infrared reflectance spectroscopy. Data was analyzed using the PROC GLIMMIX of SAS with repeated measures analysis option at a = 0.05. Leaf:stem ratio was not significant for all main effects (P &gt; 0.46). Harvest treatment had an effect on yield, with 10% bloom greater than bud stage (1,321 kg/ha and 1,104 kg/ha, respectively; P = 0.04). Crude protein levels were the greatest in bud stage and lowest with 50% bloom (22.8% and 21.2%; P &lt; 0.01). Total digestible nutrients were greater in bud and 10% bloom compared to 30% and 50% (65% and 63%, respectively; P &lt; 0.01). Potassium application and harvest regime can impact alfalfa growth. Funding for this project was provided by USDA-NIFA-AFRP grant #2016-70005-25653.

The leaf-air temperature difference reflects the variation in water status and photosynthesis of sorghum under waterlogged conditions.

Waterlogging stress is one of the most important abiotic stresses limiting sorghum growth and development. Consequently, the responses of sorghum to waterlogging must be monitored and studied. This study investigated changes in the leaf water status, xylem exudation rate, leaf anatomical structure, leaf temperature and photosynthetic performance. Waterlogging-tolerant (Jinuoliang 01, abbreviated JN01) and waterlogging-sensitive (Jinza 31, abbreviated JZ31) sorghum cultivars were planted in pots. The experiment was carried out using a split block design with three replications. Waterlogging stress was imposed at the sorghum five-leaf stage. The leaf free water content (FWC) and relative water content (RWC) decreased under the waterlogged condition. The leaf thickness was thinner under the waterlogged condition, and the main changes occurred in the upper epidermal and mesophyll cells. Gas exchange parameters and the xylem exudation rate were also restrained by waterlogging; however, greater responses of these parameters were observed in JZ31. JZ31 had a higher leaf-air temperature difference (ΔT) than JN01. We found that changes in ΔT were always consistent with changes in the RWC and the gas exchange parameters. ΔT was significantly associated with the leaf RWC, photosynthetic rate (Pn) and transpiration rate (Tr). The results suggest that ΔT may be an indicator reflecting the water status in leaves and can be used to evaluate the tolerance of sorghum to waterlogging.

Effects of NPK and plant tea manure (Tithonia diversifolia) on growth rate of amaranth (Amaranthus cruentus L.) in soilless growing media

Many countries are running short of agricultural land. Even where land appears to be available, soil fertility, water availability as well as nutrient mining still remains a challenge yet at the same time the world’s demand for food is rapidly increasing. Millions of square meters of soil are mined each year for use in vegetable nurseries and in backyard gardens in addition to excessive use of inorganic fertilizers. There are however a number of soilless growth media and organic sources of plant nutrients that could be used to address this problem. This study investigated the effects of application of NPK (Nitrogen, Phosphorus and Potassium) and plant tea (Tithonia diversifolia) manure on selected soilless growing media on growth rate of Amaranthus cruentus L. This was to determine their suitability as an alternative growing media. A split plot design was used and the experiments carried out for two seasons. The soilless growing media investigated were: charcoal dust, saw dust, dry coffee husks, and mixture of charcoal and saw dust (1:1), saw dust and coffee husks (1:1), charcoal dust and coffee husks (4:1) and a compound mixture of charcoal dust, sawdust and coffee husks (2:2:1). The growing media were randomized in the three split blocks with eight pots each. Growth rates in terms of shoot height, number of leaves, leaf length, leaf width, stem girth and root length were measured for two seasons. Results indicated that all the growth media could support amaranth growth. However, a mixture of charcoal dust and dry coffee husk (4:1 respectively) with application of plant tea manure significantly affected the growth rate of A. cruentus (p<0.05). Mixture of charcoal dust and dry coffee husk (4:1 respectively) with application of either NPK or plant tea manure could be used as the best alternative growth media. Soilless growth media that constituted of charcoal dust and coffee husks could be explored for amaranth production in home kitchen gardens in rural areas and backyard gardens in urban areas. Key words: Soil, soilless growing media, plant nutrients, amaranth.

Potentiality of Some Egyptan Cotton Varieties under Drought Stress Conditions

This study aimed to investigate the performance of three cotton (Gossypium barbadense L.) genotypes as affected by drought stress at three irrigation regimes; 14 (S-0), 21(S-1) and 28 (S-2) days that were started after the first irrigation. To achieve this goal, a field experiment was conducted as split block design at the Experimental Farm of the Faculty of Agriculture, El-Fayoum Univ. The results indicated that the irrigation regimes mean squares of combined data were highly significant for earliness traits, also as well as yield and yield components. Most of fiber properties were not affected by water stress conditions. Significant differences were found among the non- stress (S-0) and the stress treatments (S-1 and S-2) for mean performances of the three earliness traits. Treatment S-2 led to significant decrease in yield and yield components compared to S-0. The results showed that Giza 85 variety gave the highest fiber length, fiber strength and was finer cultivars having the lower micronaire values. The interaction between genotypes and stress treatments was significant for most traits.G1,G2 and G3 cotton varieties exhibited highest seed cotton yield kg ha-1 (yield potential) in the non- stress treatment (S-0). Giza 90 variety outyielded the other two varieties under stress treatment (S-2) compared to those of Giza 85 and Giza 83. The superiority of Giza 90 variety could be attributed to its high yield components., while Giza 90 was relatively stress susceptible and similar trend of those obtained using data of relative productivity (%) which confirm that the genotype Giza 83 and Giza 85 are more drought tolerance and could be used as sources of drought stress tolerance in breeding programs and tolerance to water stress conditions.

All-in-One Synchronized DNA Nanodevices Facilitating Multiplexed Cell Imaging.

Multifunctional DNA nanodevices perform ever more tasks with applications ranging from in vitro biomarker detection to in situ cell imaging. However, most developed ones consist of a series of split building blocks, which suffer from asynchronous behaviors in complicated cellular microenvironments (endocytosis pathway, diffusion-limited cytoplasm, etc.), causing the loss of stoichiometric information and additional postassembly processes. Herein, we constructed all-in-one DNA nanodevices to achieve synchronous multiplexed imaging. All DNA components, including two sets of probe modules (each containing target-specific walkers, i.e., hairpin tracks with chemically damaged bases), are modified on individual gold nanoparticles. This design not only enables their integrated internalization into cells, circumventing inhomogeneous distribution of different building blocks and increasing the local concentrations of the interacting modules, but also avoids the impact of stochastic diffusion in viscous cytoplasm. A couple of intracellular enzymes in situ actuate the synchronized motion of the modules, all on-particle, after specific recognition of intracellular targets (such as RNAs and proteins), thus facilitating synchronized, multiplexed cell imaging. Finally, the proposed all-in-one nanodevices were successfully applied to monitor intracellular microRNA-21 and telomerase expression levels. The flexible design can be extended to detect other cytoplasmic molecules and monitor related pathways by simply changing the sequences.

The Utilization of ArbuscularMycorrhizal Fungi For Planting Agarwood (Aquilariaspp) Seedling In Open Land

Agarwood is a type of semitoleran plant, so that for planting the seedlings should be grown under the shade. For planting in open land, it requires treatment in which one of them is using seedlings inoculated with arbuscularmycorrhizal fungi. The Aim of the research were: (1) to obtain information on agarwood growth that has been inoculated with fungi mycorrhizalarbuscular when planted in the open land, and (2) ability to grow between agarwood seedlings inoculated mycorrhizal that was planted in the shade and in the open area. Split Plot randomized block design was applied with treatments : the first plot consisting of plant had been inoculated with mycorrhizae and without mycorrhizal inoculation, and the sub plot was the types of shading that consists of : open land, paranet 60 % intensity and natural vegetation. To reduce variabilty of site topographical differences were separated as bloks. Variables measured were :plant height (cm), stem diameter (mm), number of leaves and survival percentage of plant. The results show that the height and diameter growth of seedlings innoculated with mycorrhizae were higher than non innoculated. The seedlings innoculated with mycorrhizal fungi were planted in the paranet shading grew better and significantly different compared to the vegetation shading. Seedlings innoculatedmycorrhizal that were planted in open land grew better and significantly different compared to vegetation shading. This study results indicate that planting agarwood in the open land can be done using seedlings inoculated arbuscularmycorrhizal fungi.

Interference of Noxious Shrubs on Grazing Behavior by Bovines

ABSTRACT: The grazing behavior practice by bovines can be positive or negatively influenced by the pasture structure where the animal is inserted. Several factors determine the pasture structure and the presence of weeds is considered one of the most important. This study aimed to assess the effect of species with and without stiff structures over the grazing behavior of bovines in pasture areas. The experimental design was a split block design with four replications, in which treatments were arranged in a 4 x 3 factorial design: four weed species (Zanthoxylum rhoifolium, Cnidoscolus urens, Dasyphyllum brasiliensis, and Luehea divaricata) associated with three proximity strips of weeds: 0-50, 50-100, and 100-150 cm in relation to the main stem of the studied weed. Forage intake by animals was measured by determining the real forage offers at 0, 3, 6, 9, and 15 days after the beginning of animal grazing (DAP). The presence of noxious shrubs influenced bovine grazing behavior. The influence on the intake is most evident in the presence of plants that promote animal discomfort. The species Z. rhoifolium, C. urens, and D. brasiliensis were the weeds with the greatest influence on feed access among the species that have stiff structures. The negative influence on grazing behavior is higher in the proximity strip closest to the plant, i.e. 0-50 cm from the main stem of the weed.

The response of corn (Zea mays L.) cultivars to row spacing under weed interference condition

This study was carried out in order to study the response of corn cultivars to row spacing and weed interference at the Research Farm of Agricultural and Natural Resources Faculty, Razi University, Kermanshah, Iran in 2011. The experiment was a split block factorial based on a randomized complete block design with three replications. Factors consisted of three corn cultivars ('KSC 704', 'Simon' and 'Maxima') and three plant row spacings (45, 60 and 75 cm) under weeded and un-weeded conditions for all of the growing season. Results indicated that for all three corn cultivars, the highest weed dry mass occurred in the row spacing of 75 cm. Weed interference throughout the growing season reduced corn grain yield by 20 %. This condition also significantly decreased corn yield components except the 100-seed mass. Increasing plant row spacing increased weed density, while decreased corn yield by 16.5 %. Corn cultivars were significantly different in terms of the number of seed per ear and 100-seed mass, as 'KSC 704' and 'Simon' showed the highest values for these yield components, respectively. However, the number of ear per plant and grain yield were not significantly different between the corn cultivars under study.

WM380 (675–700 GHz) Bandpass Filters in Milled, Split-Block Construction

Filters play an invaluable role in RF analysis and communications hardware, blocking unwanted signals, limiting bandwidth, attenuating harmonic components, etc. In waveguide construction for mm-wave frequencies, where the powers are generally low, the iris-coupled-resonator bandpass filter has proven to be very practical and amenable to easy machining. At Virginia Diodes, much of our technology has been constructed using standard “split-block” techniques, in which high-precision computer numerical control milling machines are used to mill out the features from solid blocks of metal. Typical machining tolerances are on the order of +/−5–10 μ m. Construction of such filters to ∼200 GHz has been routine but pushing the operation into the Terahertz regime requires special considerations. Described here is a WM380 (WR1.5) filter for the 500–750 GHz waveguide band having a passband of 675–700 GHz. The filter is proof of concept for a 640 GHz heterodyne polarimeter, designed as a part of a Small Business Innovative Research (SBIR) Grant to develop technology for NASA's planned Aerosol, Cloud, and Ecosystems mission. From the very beginning, filter design and optimizations were carried out assuming the structure would be milled, hence necessitating that all internal features accommodate the finite radii of available machine tools. Construction of this filter required careful attention to machining tolerances to be able to push the milling machines to their absolute limits of +/−2.5 μ m or better. Measured results of a batch of filters are shown and compared to simulations to illustrate just how well these filters can be made. Furthermore, the filters can be tuned by simple mechanical means and data are presented to illustrate how easily the filters can be adjusted. Additional modifications to the filter topology to simplify machining, and allow other construction techniques to be utilized are also demonstrated. Ultimately it should be possible to push the split block technology to manufacture iris coupled resonator filters for use at frequencies of well over 1 THz.