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As energy declines, growing food locally inside and on the rooftops of buildings is touted as a great idea. No need for diesel tractors, harvesters, and long-haul trucks and their dirty emissions. By merely pressing seeds into soil, voila! A harvest 6 weeks later using free sunshine and rain, sheltered from bad weather, plus increasing food security in the neighborhood. Sorting the wheat from the chaff, this chapter examines the pitfalls of these urban farms and whether this is a workable way to feed more people or grow more biomass.

International audience; Imprints of domesticated pearl millet (Pennisetum glaucum (L.) R. Br.) spikelets, observed as temper in ceramics dating to the third millennium BC, provide the earliest evidence for the cultivation and domestication process of this crop in northern Mali. Additional sherds from the same region dating to the fifth and fourth millennium BC were examined and found to have pearl millet chaff with wild morphologies. In addition to studying sherds by stereo microscopy and subjecting surface casts to scanning electron microscopy (SEM), we also deployed X-ray micro-computed tomography (microCT) on eleven sherds. This significantly augmented the total data set of archaeological pearl millet chaff remains from which to document the use of the wild pearl millet as ceramic temper and the evolution of its morphology over time. Grain sizes were also estimated from spikelets preserved in the ceramics. Altogether, we are now able to chart the evolution of domesticated pearl millet in western Africa using three characteristics: the evolution of non shattering stalked involucres ; the appearance of multiple spikelet involucres, usually paired spikelets; and the increase in grain size. By the fourth millennium BC, average grain breadth had increased by 28%, although spikelet features otherwise resemble the wild type. In the third millennium BC, the average width of seeds is 38% greater than that of wild seeds, while other qualitative features of domestication are indicated by the presence of paired spikelets and the appearance of non dehiscent, stalked involucres. Non shattering spikelets had probably become fixed by around 2000 BC, while increases in average grain size continued into the second millennium BC. These data now provide a robust sequence for the morphological evolution of domesticated pearl millet, the first indigenous crop domesticated in western Africa.; Des empreintes d’épillets de mil domestiqué (Pennisetum glaucum (L.) R. Br.) observées dans des céramiques datées du 3e millénaire av. J.-C. provenant du nord du Mali constituent les plus anciens témoins de la mise en culture et de la domestication de cette céréale. Des tessons supplémentaires issus de la même région se rapportant aux 5e et 4e millénaires av. J.-C. ont été examinés et ont révélé des empreintes de balle de mil de morphologies sauvages. En plus de l’observation de leurs surfaces par stéréo-microscopie, et de l’observation des moulages d’empreintes au microscope à balayage, onze d’entre eux ont fait l’objet de microtomographies aux rayons X (microCT). Ces examens enrichissent considérablement l’ensemble des données archéologiques concernant l’utilisation du mil sauvage comme dégraissant végétal et son évolution morphologique à travers le temps. La taille des grains a aussi été estimée à partir des épillets conservés dans la céramique. En tenant compte des données enregistrées lors d’études antérieures, nous pouvons désormais retracer l’évolution du mil domestiqué en Afrique de l’Ouest à travers trois caractéristiques : l’évolution des involucres pédonculés à égrenage non-spontané; l’apparition d’involucres multiples par épillets, des épillets appariés le plus souvent; l’augmentation de la taille des grains au vu de leur largeur. Déjà au 4e millénaire avant J.-C., la largeur moyenne des grains a augmenté de 28% bien que les caractéristiques de l'épillet ressemblent au type sauvage. Au 3e millénaire avant J.-C., elle est 38% supérieure à celle du morphotype sauvage, tandis que des caractéristiques qualitatives de la domestication sont avérées par la présence d’épillets appariés et par celle d’involucres pédonculés à égrenage nonspontané. La non-déhiscence des épillets est un caractère de domesticité qui s’est probablement fixé vers 2000 avant J.-C. L’augmentation de la taille moyenne des grains s’est poursuivie tout au long du 2e millénaire av. J.-C. Ces données fournissent désormais une séquence robuste concernant l’évolution morphologique du mil, la première céréale indigène domestiquée en Afrique de l’Ouest.

This article presents the study of significant factors influence on the pelletizing process of soybean chaff. The aim of the research was to determine the operating modes of the screw providing chaff soybean pellets output with a crumbling of not more than 12% at the optimum pelletizing temperature of 70 — 80°C. To study the significant factors influence - such as the flight screw step, the screw rotation speed, chaff moisture - on the process of soybean chaff pelletizing, as well as the optimal values variation of these factors, search experiments were conducted on the screw type laboratory pelleting press XP-3. Regression equations were calculated as a result of the studies, which are adequately describing the influence of significant factors on the output of proper quality pellets; this will allow to develop the technology for chaff compacting in the process of stationary processing of the grain and soybean heap, which allows to reduce the costs of transportation and storage of soybean chaff.

Chaff cutters are extensively used in agriculture for cutting fodder to feed livestock. Conventional chaff cutting machines operated manually are linked with large number of injuries in the past. Apart from single incident traumatic events, the machine could be the source of development of WMSDs over time. In the present study, ergonomics of chaff cutting machine have been evaluated through physiological measures. Electromyography (EMG) of four right upper limb muscle viz. biceps brachii (BB), triceps brachii (TB), trapezius (TR), and deltoid (DL) was evaluated for five subjects. Normalized RMS and slope of median frequency (MF) showed that BB was most fatigued muscle in the operation of chaff cutter compared to TB, TR, and DL. The identification of upper limb muscles involved in the task will serve as a starting point for tool modification.

Chaff cloud has been widely used in many battle scenes for its low cost and good jamming performance. Chaff is always released from the airplane. In this paper, the model of the chaff cloud in airflow is descried using reaction-advection-diffusion equation. Then, Vector Transport Theory (VRT) is adopted to evaluate the scattering properties of the chaff cloud. In this paper, the transmitting and receiving antenna are lineer or circular polarized. Simulations show that if the receiving antenna is liner polarized, it is appropriate to illuminate the chaff cloud with a circularpolarization wave to achieve a good jamming performance. At the samr time, one can optimize the design of the chaff element to achieve a uniform orientation distributions for improving the jamming performance.

Organic farmers farming on arable land have often had, in addition to the cultivation of common species of cultivated crops (such as wheat, rye, triticale or potatoes), interest in the cultivation of marginal crops such as hulled wheat species (Einkorn, Emmer and Spelt wheat). The production of marginal cereals has seen significant developments in the European Union related to the development of the organic farming sector. Just the average annual organic production of spelt in the Czech Republic reached more than 9000 tons in 2018. The cultivation of these cereals requires post-harvest treatment in the special method of dehulling. The waste emerging after dehulling of spikelet (i.e., chaff) accounts for about 30% of the total amount of harvest and can be used as an alternative fuel material. When considering the energy utilization of this waste, it is also necessary to obtain information on the energy quality of the material, as well as environmental aspects linked to their life cycle. For evaluating the energy parameters, the higher and lower heating value, based on the elemental (CHNS) analysis, was determined. The environmental aspects were determinate according to the Life Cycle Assessment (LCA) methodology where the system boundary includes all the processes from cradle to farm gate, and the mass unit was chosen. The SimaPro v9.1.0.11 software and ReCiPe Midpoint (H) within the characterization model was used for the data expression. The results predict the energy potential of chaff about 50&ndash, 90 TJ per year. The results of this study show that in some selected impact categories, 1 kg of chaff, as a potential fuel, represents a higher load on the environment than 1 kg of lignite, respectively potential energy gain (1 GJ) from the materials.

Nitrogen (N) remobilization is a critical process that provides substantial N to winter wheat grains for improving yield productivity. Here, the remobilization of N from anthesis to maturity in two wheat cultivars under three irrigation regimes was measured and its relationship to organ N concentration was examined. Based on spectral data of organ powder samples, partial least squares regression (PLSR) models were calibrated to estimate N concentration (Nmass) and validated against laboratory-based measurements. Although spectral reflectance could accurately estimate Nmass, the PLSR-based Nmass-spectra predictive model was found to be organ-specific, organs at the top canopy (chaff and top three leaves) received the best predictions (R2 > 0.88). In addition, N remobilization efficiency (NRE) in the top two leaves and top third internode was highly correlated with its corresponding N concentration change (ΔNmass) with an R2 of 0.90. ΔNmass of the top first internode (TIN1) explained 78% variation of the whole-plant NRE. This study provides a proof of concept for estimating N concentration and assessing N remobilization using hyperspectral data of individual organs, which offers a non-chemical and low-cost approach to screen germplasms for an optimal NRE in drought-resistance breeding.

Natural rubber is a gummy liquid obtained from the sap fluid of the tree Hevea brasilensis. It is a natural hydrocarbon polymer of 2-methyl-1-3-butadiene (isoprene), which contains one double bond per repeating unit, whose structural arrangement typifies that of a cis-isomer (cis-polyisoprene). Natural rubber in its raw gum state is tacky, fairly elastic but suffers some limitations such as poor resistance to weathering condition, low tensile strength and hence additives are always added to improve on the limitations of the natural Rubber. Most additives are imported hence constituting additional cost. Cowpea chaff was used in this study as one of the additives. The cowpea chaff was chosen for this research due to its availability and cost since it is a waste material and expected to reduce cost of production. The cowpea chaff was grinded and sieved to fine particles (powder) using 100µm. The cowpea chaff powder was divided into portions and part were modified via nitration. The modified and unmodified cowpea chaff powder were characterized to determine the Ash content, Moisture content, Volatile content, pH, Loss on ignition, X-ray florescence (XRF) analysis was carried out to ascertain the elemental composition and Infra-red spectroscopy (FT-IR) to determine the functional groups and extent of the reaction of the samples. Each of the portions were compounded with Natural Rubber (NR) using calcium carbonate as control. The physico-mechanical properties of the vulcanizates obtained were determined. The study showed that chemically modified and unmodified cowpea chaff powders were good additives (softeners). Based on the parameters tested, it can be concluded that cowpea chaff can be substituted with CaCO3 filler in NR vulcanizates.

Comparative studies of the classical and new design of a chaff cutter&rsquo, s cutting drum have been conducted within the frames of the study in order to determine their functional characteristics at the time of cutting rye straw into pieces of specific length (into chaff). A classical design of a cutting drum is of the shape of a roller and is suitable for material layer cross-cutting. However, the new drum design has the shape of a double truncated cone and, with the use of it, diagonal cuts in two directions can be realized. The studies were conducted for four designs of cutting drums with cutting angles &alpha, = 0&deg, (classical design) and &alpha, = 15&deg, &alpha, = 30&deg, and &alpha, = 45&deg, (new design). Three indicators were applied for the assessment: capacity, unit energy consumption, and the unit cutting resistance. The obtained results show that the use of a new drum design makes it possible, depending on the assumed parameters of the cutting process and the material&rsquo, s compaction degree, to increase the process&rsquo, s efficiency by up to 25%, lower the unit energy consumption up to 34%, and lower the unit cutting resistance by up to 8%. The conducted experimental studies have unequivocally shown that the use of a new cutting drum design, as compared to the classical one, results in a considerable increase in the cutting process&rsquo, s performance. Studies on the new design of a chaff cutter&rsquo, s cutting drum, of the shape of a double truncated cone, belong to original ones that so far have not been described in the available literature.

Cereals were a significant part of the Roman diet, yet knowledge about their cultivation, distribution and consumption in certain regions is particularly lacking. In Europe, studies generally suggest that from the Iron Age to the Roman period there was a reduction in barley cultivation, an increase in spelt over emmer, a preference for free-threshing wheat over glume wheats, as well as the increased cultivation of rye and oats. Up till now, there was little evidence on crop cultivation in Croatia, but the discovery of around 24,000 cereal grains from the oven of a 2nd-4th c. AD Roman villa in the modern town of Osijek provides important insights into diet and subsistence in the Roman province of Pannonia. Here, the dominance of free-threshing wheat, spelt and rye with only a relatively small amount of other cereals, chaff and weeds corresponds well with this pattern seen elsewhere in Europe. The relatively clean grain deposit suggests that this sample represents processed grain ready for final food preparation and consumption at the villa. The morphological variation and overlap seen between the carbonised spelt and free-threshing wheat grains, as well as the identification of ‘stunted’ cereal grains, is also discussed.

A custom response design study on the biogas production from blends of Palm oil sludge (POS), Bambara nut (VignaSubterranea) chaff (BNC) and African wild mango (AWM) was carried out. The anaerobic digestion was in the ratio of 3:1 and 2:1 of water to waste depending on the nature of the substrates as follows: System A was 100%POS; B: 100%BNC, C: 100%AWM;D: 50%POS+50%BNC and E: 60% POS+20% BNC+20% AWM. The wastes were charged into 32L capacity metal prototype digesters in a batch for 30 days retention period at an ambient temperature range of 26oC - 37°C. The cumulative gas yield from the five treatments systems (digesters) were different: the 50%POS+50%BNC had the highest cumulative gas yield (69.5L); followed by 100%BNC system (54.5L); 60%POS+20%BNC+20%AWM system (39.2L); 100%POS system (14.4L) and 100%AWM system (11.7L). 100%BNC system had the highest methane content (88.056%); followed by 60%POS+20%BNC+20%AWM system (88.007%); 100%POS system (83.025%); and 50%POS+50%BNC system (73.055%).The research has shown that 100% BNC had the least lag days (6 days), highest calorific value (25330.24KJ/Kg) and highest methane content (88.056%). African wild mango needs to be co-digested to produce flammable biogas. The TS, VS, BOD and TVC were seen to be consistently reducing throughout the digestion period. Meteorological conditions like solar radiation, air temperature and wind speed had significant effects on ambient temperature, slurry temperature, pH and daily gas yield.

In this paper, monostatic RCS performance studies were carried out for metalized glass dipoles. RCS modelling and simulationhas been carried out for array of dipoles which is followed by the RCS measurement in anechoic chamber at 3-8 GHz. Good agreement in the simulations and measurements has been observed which validates the comparison criteria and also the performance of dipoles for application as chaff material.

Background Seed size and number are important plant traits from an ecological and horticultural/agronomic perspective. However, in small-seeded species such as Arabidopsis thaliana, research on seed size and number is limited by the absence of suitable high throughput phenotyping methods. Results We report on the development of a high throughput method for counting seeds and measuring individual seed sizes. The method uses a large-particle flow cytometer to count individual seeds and sort them according to size, allowing an average of 12,000 seeds/hour to be processed. To achieve this high throughput, post harvested seeds are first separated from remaining plant material (dust and chaff) using a rapid sedimentation-based method. Then, classification algorithms are used to refine the separation process in silico. Accurate identification of all seeds in the samples was achieved, with relative errors below 2%. Conclusion The tests performed reveal that there is no single classification algorithm that performs best for all samples, so the recommended strategy is to train and use multiple algorithms and use the median predictions of seed size and number across all algorithms. To facilitate the use of this method, an R package (SeedSorter) that implements the methodology has been developed and made freely available. The method was validated with seed samples from several natural accessions of Arabidopsis thaliana, but our analysis pipeline is applicable to any species with seed sizes smaller than 1.5 mm.

In cereal crops, chaff is a valuable lignocellulosic by-product that accounts for more than50 Mt y-1 in Europe and is suitable for bioenergy purposes. Chaff is usually not collected due tothe lack of combine harvesters that have the capability to handle it properly. The present two yearsexperimental study investigated the hypothesis that the overall biomass collected in wheat crop canbe increased by equipping the combine harvester with an aftermarket device. Chaff, dischargedfrom the combine harvester-cleaning system, is collected by the turbine that delivers it either on theswath or on a lateral trailer towed by a tractor. The performance of all machines involved in theharvesting (combine harvester, tractor, baler, and trailer) were assessed. The chaff was collected in bales with the straw (A mode) and separately on a trailer (C mode). Comparisons with non-collected treatment (B mode) were performed in order to estimate the total chaff collected and the biomasslosses. The results showed that 1.79 t FM ha-1 per year of chaff could be collected when baled with thestraw, whereas 1.27 t FM ha-1 were collected separately on a trailer. Both field and material capacitywere not negatively affected by the chaff collection. Therefore, our study confirmed the hypothesis that turbine technology is a valid solution for increasing the total residual biomass collected in cerealcropping for energy purposes.

The article presents some of the research on the wider work related to testing and improving a new rotary cleaning device. The new cereal grain cleaning and separation device can support the development of sustainable agriculture in terms of seed purity and quality. This device is especially useful for small and medium-sized farms. This device has the characteristics of a multi-stage screen aided by an air stream (i.e., by pneumoseparation). The prototype was constructed at the University of Life Sciences in Lublin. The research was conducted at a test stand, which allowed changes in the operating parameters of the cleaner and their measurement. The scope of the tests included determining the influence of the inclination angle of the sieve unit (&alpha, ) on the effectiveness and efficiency of oat grain cleaning. The experiment was carried out using two rotational spindle speeds: 5 and 75 rpm. The quality of the separation and cleaning of oat grains was evaluated using six cleaning process parameters: plump grain mass separation coefficient (Spg), fine grain separation coefficient (Sfg), fine impurities separation coefficient (Sfi), chaff separation coefficient (Sch), total coefficient of cleaning effectiveness (E), plump grain cleaning efficiency (qpg). Results showed the significant effect of the sieve drum inclination angle on the efficiency and effectiveness of oat grain cleaning.

To solve the kinetic and diffusion problem of surface-type infrared decoy, multi-chaff kinetic models are established and chaff cloud holistic kinetic performance are analyzed under the impact of high speed airflow in this work. Chaffs rotate rapidly during the motion under the impact of high speed airflow. The rotation speed is correlated with lift, position of pressure center and aerodynamic damping. Computational Fluid Dynamics (CFD) is used to compute the aerodynamic coefficients of chaff. It is found that there exists serious aerodynamic interference which mainly relates to the overlapping area and distance among chaffs during the diffusion of chaff cloud. The chaff wind tunnel test and rocket sled experiment are carried out to verify the credibility of the models in this work. Then, the variation of chaff cloud expectation and extremum are analyzed to achieve the holistic kinetic and diffusing performance of chaff cloud. Simulation results demonstrate that the chaffs diffuse rapidly under the impact of high speed airflow and chaff cloud can be formed rapidly within 0.5 s. The shape of the chaff cloud is similar to cone that forms a certain angle with the horizontal plane and most chaffs focus on the second half. Keywords: Aerodynamic coefficients, Chaff, Computational fluid dynamics, Infrared decoy, Wind tunnel test

Phytolith analysis has been applied in one of the extraordinary Trypillia “mega-site” in central Ukraine. The site Maidanetske, dated to ca. 3900–3650 BCE, is composed of ca. 3000 houses, which were built of earth-based architecture. As these mega-sites were extremely large, their relatively short duration and their population dynamics are under debate. In this study, the focus is set on the detection of daily household activities, including cereal processing. Archaeological contexts have been sampled for phytoliths inside and outside houses, including daub fragments, grinding stones, vessels, floor surfaces and a pit filling. Phytolith records from layers above and below the archaeological contexts were also analysed. The results indicate that cereal by-products such as chaff from pooid cereals, were in use for specific purposes like daub tempering for house building. Thus cereals were a relevant part of the site subsistence economy despite the scarce preservation of archaeobotanical macro-remains. While chaff and straw suggest on-site processing of cereals, the location of processing is unclear. Since house floors and cultural layers are poorer in chaff phytoliths than expected, the future analysis of other special buildings for instance might help to detect specialised areas of processing apart from houses. Besides cereals the phytolith record attests also the presence of wild grasses with probable indication of steppe grassland components. Further investigation of soil sequences outside the site and comparison with modern reference material in future will help to assess the development of the grassland vegetation through time.

Recent canola acreage and production in western Canada have reached record high levels. Field experiments were conducted from 2014 to 2016 on land previously seeded to continuous canola for 6 yr at three Canadian Prairie sites. We determined that more intensive seed inputs, fertilizer, fungicide, tillage, or chaff removal could increase continuous canola yields compared with a “standard practice” (SP) treatment or match yields compared with canola in rotation. Recommended or 50% higher fertility levels alone or in combination with a higher seeding rate, tillage, chaff removal, or additional fungicide were applied to the same plots in three successive years to determine effects after 1, 2, and 3 yr of treatment imposition. In continuous canola, blackleg incidence and severity were both reduced by fungicide treatment. In rotations where canola was preceded by wheat, blackleg incidence and severity were much lower than in continuous canola. None of the treatments improved continuous canola yields compared with SP after a single year of treatment imposition. In subsequent years, canola yield increases compared with SP usually occurred as a result of additional fertilizer, seed, or fungicide. In the final year, canola yield loss due to continuous canola was largely rescued by additional seed and fertilizer. Without additional inputs, and when preceded by a different crop, canola yields averaged 11% greater than the average of all continuous canola treatments. High fertility regimes generally reduced oil content and increased protein content relative to standard fertility in continuous canola or relative to canola preceded by wheat.

In building applications, recycled waste materials are becoming promising acoustic absorbers and thermal insulating solutions in order to reduce the environmental impact. The aim of the research is to evaluate the thermal, acoustic, and environmental performance of recycled waste panels consisting of rice husk (RH) produced by gluing and pressing the raw material. Its acoustic and thermal performance were compared with the ones of six panels composed by other recycled materials (cork scraps, end-life tires, coffee chaff, waste paper, textile fiber mats, wool fiber scraps), assembled with similar techniques. Thermal resistance of RH is equal to 0.59 m2K/W, in the same order of magnitude of many traditional systems. Sound absorption coefficients were measured by means of the impedance tube. All the panels present acoustic absorption comparable with traditional ones (peak values 0.87–0.99). RH peak value is 0.87, while the maximum values are obtained for cork and wool fiber scraps (1 and 0.97 respectively). Life cycle analysis, performed in compliance with ISO 14040 showed the best environmental performance for the production of 1 m2 of RH and coffee chaff panels. Taking in account their acoustic and thermal behaviour, the wool fiber scraps presents a very good performance.

Chaff is a radar countermeasure typically used by military branches in training exercises around the United States. Chaff within view of the S-band WSR-88D beam can appear prominently on radar users’ displays. Knowledge of chaff characteristics is useful for radar users to discriminate between chaff and weather echoes and for automated algorithms to do the same. The WSR-88D network provides dual-polarimetric capabilities across the United States, leading to the collection of a large database of chaff cases. This database is analyzed to determine the characteristics of chaff in terms of the reflectivity factor and polarimetric variables on large scales. Particular focus is given to the dynamics of differential reflectivity ZDR in chaff and its dependence on height. In contrast to radar observations of chaff for a single event, this study is able to reveal a repeatable and new pattern of radar chaff observations. A discussion about the observed characteristics is presented, and hypotheses for the observed ZDR dynamics are put forth.

This article studies the scattering of the orbital-angular-momentum (OAM) carrying wave by chaff clouds. The OAM-carrying wave (vortex wave) has different phase distribution and amplitude distribution from the plane wave, thus the scattering characteristics of vortex wave by chaff clouds need to be investigated. There are three aspects studied through analysis and numerical computation here, including the scattering by a single dipole, the transmitted wave through the chaff clouds, and the back-scattering by chaff clouds. The results show that the transmitted wave is not an ideal vortex wave any more after transmitting through the chaff clouds, but the information carried by vortex wave can more easily pass through the chaff cloud than plane wave. The reason is that the information is located on the azimuth-angle domain (OAM modes) besides the time domain and the frequency domain. So, the information can be detected by OAM-mode filtering. It may also be beneficial for the application of the vortex wave in chaff jamming.

Investigations were conducted to compare gas produced from co-digestion of corncob, rice chaff, goat dung and dog dung with commercial gas. The study was carried out anaerobically at a temperature of 29.5 to 33°C (mesophilic condition) in a mini laboratory digester (bioreactor) fabricated using guage 16 metal sheets with 80-L capacity for a 90-day retention time. The shredded corn cob and rice chaff were mixed with water at ratio 4:1 (waste to water) and 3:1 (waste to water) respectively and mixed with goat and dog dungs at ratio 2:1 (waste to water). The control sample collected from a domestic cooking gas cylinder contained 56.12% CH2, 0.14% NH3, 0.22% CO, 0.23% H2S and 43.20% CO2. The result obtained for the biogas analysis shows that Sample E (75:25) contains 63.54% CH4, 0.93% NH3, 0.84% CO, 0.54% H2S, 34.12% CO2. The value recorded for sample E represented the highest value obtained among the samples. Also the gas composition shows a good substitute for commercial gas. Key words: Corn cob, rice chaff, goat dung, dog dung, biogas, commercial gas, bioreactor and digestates.

This study discusses the capability of the orthogonal frequency division multiplexing (OFDM) radar recognition on the aircraft in the chaff jamming, in contrast to the linear frequency modulation (LFM) signal form. The process result of the LFM signal form induces a fake target in the recognition on the aircraft in the chaff jamming, because the range and the Doppler are coupled. The process result of the OFDM signal form can separate the real target and the chaffs clearly, because the range and the Doppler are uncoupled from the signal form. The OFDM signal form is a novel and efficient way to solve the chaff jamming.

Different fractions during the 85-day windrow composting were characterized based on various parameters, such as physiochemical properties and hydrolytic enzyme activities; several technologies were used, including spectral scanning techniques, confocal laser scanning microscopy (CLSM) and 13 C Nuclear Magnetic Resonance Spectroscopy ( 13 C NMR). The evaluated parameters fluctuated strongly during the first 3 weeks which was the most active period of the composting process. The principal components analysis (PCA) results showed that four classes of the samples were clearly distinguishable, in which the physiochemical parameters were similar, and that the dynamics of the composting process was significantly influenced by C/N and moisture content. The 13 C NMR results indicated that O-alkyl-C was the predominant group both in the solid and water-soluble fractions (WSF), and the decomposition of O-alkyl-C mainly occurred during the active stage. In general, the various parameters indicated that windrow composting is a feasible treatment that can be used for the resource reuse of agricultural wastes.

In modern warfare scenario, chaff cloud consisting of millions of small individual microwave scatterers, is used as a passiveelectronic countermeasure to rapidly create a false target having Radar Cross Section (RCS) more than a real target. RCS prediction of chaff cloud by modeling and simulation is a complex phenomenon as each scatterer has different resonating length, oriented randomly and interact with each other in a complex form. Monostatic RCS measurement of the chaff cloud in the real scenario is also difficult as the target size is quite big and shape and size are changing with time. In the present paper, the dynamic RCS prediction of chaff cloud has been carried out by modeling and simulation using the in-house developed software in MATLAB. Various regular shapes like a plume, sphere, cylindrical and cubical have been presumed and interaction of each scatterer has been analytically evaluated based on screening effect. RCS response of chaff clouds of different shapes and sizes were predicted. To validate the predicted RCS values, miniaturized models of different shapes and sizes are prepared to simulate scale down dynamic chaff cloud blooming. Their monostatic RCS responses were measured in the anechoic chamber for 8-18 GHz. A good agreement is observed in measurement and predicted values.

Chaff centroid jamming released by vessel causes the indicated angle of radar seeker of anti-ship missile to deviate from the target. The failure to track the target is catastrophic for the radar seeker. In this paper, the angle estimation of the target in the presence of chaff centroid jamming is investigated. In the circumstance of chaff centroid jamming, the jamming is usually in the same range and angle resolution cells as the target. Under these circumstances, the essence of this problem is to estimate two unresolved targets’ angles in the main beam of the radar seeker. To this end, two alternative methods are proposed to estimate the direction of arrival of the target in this paper. First, we present a maximum likelihood (ML) method implemented by a 2-D numerical search, which has high estimation accuracy but large computational load. Subsequently, considering both the accuracy and computational load, an improved ML (IML) method is developed. Based on the ML method, the proposed IML method adopts a search optimization processing by moment estimation. Furthermore, the effects of some key factors on the estimation performance are analyzed. The accuracy of the proposed methods is compared with the existing methods and the Cramer Rao lower bound as well.

Earth plasters and renders tend to crack and crumble due to weathering. Their resilience can be improved by adding sand or fibre to the earth mixture. This paper presents an extensive literature review on earth mortar studies and the results of some experiments to strengthen the earth mortars with different sands and fibres. These experiments showed that regardless of the type of fibre or sand used, the impact on shrinkage was positive but negative on mechanical strength. Although 5% chaff improved flexural and compressive strength, increasing fibre content to > 10% reduced compressive strength, and to > 20% also reduced flexural strength.