Influence Of Different Densities Research Articles

Effect of Sinonovacula constricta on sediment microbial numbers and easily degradable organics in shrimp-crab polyculture systems

To explore the influence of different densities of Sinonovacula constricta on the composition of easily degradable organic matter and related functional bacteria, four experimental ecosystems were established: three polyculture systems (PMB1, PMB2, and PMB3) of Portunus trituberculatus and Marsupenaeus japonicus with different stocking densities of S. constricta (11.6, 23.1, and 34.7×104 ind./hm2, respectively) and a polyculture system with only P. trituberculatus and M. japonicus (PM). Among the easily degradable organic components in all aquaculture systems, protein content was the highest (0.74%~0.86%), followed by carbohydrates (0.16%~0.21%) and lipids (0.06%~0.13%). In the high-density (34.7×104 ind./hm2) S. constricta mixed culture system, the contents of carbohydrates, lipids, and proteins in the sediment were significantly lower than those of the other polyculture systems. The number of cellulose-decomposing bacteria in PMB3 was 3.79×106 cfu/g, which was significantly higher than that in the other systems. The number of starch-degrading bacteria and glutin-degrading bacteria was the lowest in PMB3, 1.26×104 cfu/g, and 160.00 cfu/g, respectively. The number of lipid-degrading bacteria in PMB3 was 0.77×104 cfu/g, which was significantly lower than that in the other systems. The easily degradable organics content in sediment was significantly positively correlated with the corresponding functional bacteria. The results showed that mixed culture of S. constricta could reduce the content of easily degradable organics in the sediment of mariculture ponds and change the number of functional bacteria in the sediment and the availability of degradable organic sediments may determine the abundance of corresponding degradable bacteria.

The Influence of Calendering on the Moisture Sorption Behavior of Electrodes for Lithium-Ion Batteries

Moisture is considered to be one of the most critical contaminants in Lithium-ion batteries (LIBs), as it impairs the electrochemical performance and poses high safety risks. To reduce the moisture in the cells below a critical level, electrodes and separators for LIBs need to be post-dried before cell assembly. However, the moisture adsorption, desorption and re-adsorption behavior of electrodes is defined by the chosen material system, the manufacturing route and the microstructure of the coatings. The microstructure, in turn, is significantly determined by the calendering step, which predominantly aims at increasing the specific density and consequently, the volumetric energy density of the electrode coatings. As the calendering step decisively changes the microstructure of the electrode coatings, it can be assumed that it accordingly must have an impact on the moisture sorption behavior of the electrodes during further processing. The sorption equilibrium of electrode coatings mainly depends on the surface of the particles, the sorption in the binder system and, to a certain extent, on the capillary condensation. LIB cathodes are most commonly manufactured with polyvinylidene fluoride (PVDF) as a binder. PVDF is very hydrophobic, which is why we can assume that the moisture sorption of these cathodes is fundamentally determined by sorption on the surface and, to a lesser degree, on capillary condensation. In contrast, the moisture sorption of LIB anodes produced with a carboxymethyl cellulose/styrene-butadiene (CMC/SBR) binder system is assumed to be mainly defined by moisture sorption of the very hygroscopic binder system. Changes to the surface should only have a small influence.Hence, it is expected that the impact of the calendering step on the moisture sorption is far more pronounced for the cathodes than for the anodes. To prove this theory and analyze the impact of the calendering step in detail, the influence of different densities on the moisture sorption behavior, microstructural properties and electrochemical performance of NCM622 cathodes with PVDF binder and graphite anodes with CMC/SBR binder system is investigated. Therefore, the electrodes are calendered to three different densities in dry room atmosphere, post-dried in vacuum and assembled into coin cells.Focusing on the cathode, after calendering an increasing moisture content is observed for increasing density, measured by Karl Fischer Titration and proved by sorption measurements. Although post-drying significantly reduces the moisture content of the cathodes, the course trend is still the same with the lowest moisture at a low density and the highest moisture at high density. Via SEM analysis, a rising amount of active material particle cracks is detected with increasing density. BET measurements show that this phenomenon is accompanied by an increasing specific surface area. Hence, the increased moisture uptake of cathodes with higher density can be mainly traced back to their higher specific surface area, caused by particle cracking during calendering. Further analytics display that the chosen post-drying parameters lead to an increase of cohesion strength for all cathodes, whereas the influence on the electrical resistance depends on the density of the cathode. The electrochemical testing shows that the increased electrochemically active surface area of the cathodes with higher density results in a good performance during formation and at lower C-rates. However, the reduced porosity lowers the ionic conductivity and leads to capacity losses at higher C-rates. [1]Concerning the anode, as expected, the influence of the calendering step on the moisture sorption is much smaller. Although the specific surface area of the anodes also increases with rising density, a significant increase of moisture is not observed. Hence, the influence of the changes in microstructure is overlapped by the hygroscopic binder system of the anodes. Post-drying increases the adhesion strength of all anodes, whereas the electrical resistance seems to decrease to a small degree. The electrochemical analysis of the anodes shows a deterioration of performance with increasing density, due to limitations of the ionic conductivity at lower porosities.Altogether, we will show that for NCM622 cathodes with PVDF binder, the moisture uptake increases with increasing density after calendering, whereas there is no change in moisture content at graphite anodes with CMC/SBR binder system. These findings make an important contribution to a better process understanding and consequently, improved moisture management along the entire process chain of Lithium-ion batteries.[1] F. Huttner, A. Diener, T. Heckmann, J. C. Eser, T. Abali, J. K. Mayer, P. Scharfer, W. Schabel, A. Kwade, Increased Moisture Uptake of NCM622 Cathodes after Calendering due to Particle Breakage, J. Electrochem. Soc. 168 090539 (2021), doi.org/10.1149/1945-7111/ac24bb, CC BY 4.0

Вплив густоти насаджень на біометричні показники і продуктивність рослин тютюну в умовах Центрального Лісостепу України

Goal. To study the influence of different densities of planting tobacco varieties on the growth, development, plant yield, and quality of tobacco raw materials in the Central Forest-Steppe of Ukraine. Methods. Field (laying the experiments, phenological observations and biometric measurements, morphological description of plants), laboratory (assessment of yield and quality of tobacco raw materials), statistical (mathematical processing of research results). Results. Experiments were performed based on the Tobacco Research Station of the NSC “Institute of Agriculture of NAAS”. They showed that the biometric parameters of tobacco plants depended on the weather conditions, cultivation, and crop density. With the increasing density of plantations in tall varieties (Krupnolystyi and Virginia cultivars) plant height decreased by 1.5–15 cm and amounted to 166–192 cm (57 thousand plants/ha). For low-growing tobacco varieties (Berlei cultivar) the optimal planting density was 48 thousand plants/ha, at which the height of plants was 127–161 cm. The number of leaves on plants depended on their height and was 19.7–25.7 pieces. Their largest size was found at plantation densities of 40 thousand plants/ha. The maximum yield of tobacco was obtained at plantation densities of 57 thousand plants/ha in tall varieties and 48 thousand plants/ha — in low-growing varieties. However, increasing the density of plantations reduced the yield of marketable raw materials by 2.3–4.8%. The highest marketability of raw tobacco was characterized by varieties Berley 9 and Temp 321, whose indicators were 73.9 and 74.8%, respectively, with plantation densities of 40 thousand plants/ha. For large-leaved tobacco varieties with plantation densities of 40,000 plants/ha, it was easier to break leaves by hand, and leaves that remained on the plant were less mechanically damaged, i.e. productivity at harvesting works increased. Conclusions. For soil and climatic conditions of the Central Forest-Steppe of Ukraine the best density of plantings for tall tobacco varieties (Krupnolystyi and Virginia cultivars) should be considered 57 thousand plants/ha, and for low-growing varieties (Berley cultivar) — 48 thousand plants/ha.

The study of the influence of slug density on the mixing performance in the reactor vessel, using PLIF experiment and FLUENT simulation

The study of the influence of different densities on the mixing behavior is very important in industries such as nuclear reactors. In this study a PLIF experiments and CFD simulation were performed to study the effect of slug densities on the mixing process in the vessel down-comer. Three different tests of different injected slug densities 1028, 1060 and 1090 kg/m3 were performed in HEU facility. Mixing of injected slug of 0.014 mg/L concentration of Rhodmine-B and ambient water in the vessel investigated by the Laser induced fluorescence technique. To provide a qualitative analysis of the results, the average values of the mass fraction at specified locations (y = 0 cm and y = 5 cm below the inlet part) were calculated for each experiment test and contour plots were created. These contours represent snapshots of the concentration field captured for the three tests. It is observed from the results, the mixing behavior in the vessel down-comer was strongly depend on the slug density. The mixing was slower when the density difference between the slug and ambient water was high and conversely the mixing behavior was higher when the density difference was low. A selected experimental result was used to validate CFD. The CFD simulations were carried out with FLUENT code and the turbulent model that used in this simulation was Reynolds stress model (RSM). A good agreement was achieved between experimental data and CFD-Fluent simulation.

Carbon Storage Allocation Characteristics of Platycladus Orientalis Plantation Ecosystem with Different Densities

<p>Purpose: To research the influence of different densities of Platycladus orientalis plantation on the allocation characteristics of carbon storage in the ecosystem, the density regulation experiment on the Pinus massoniana plantation with different densities was carried out to discuss the change of the carbon storage of the ecosystem. Method: The density regulation experiment was carried out using random block design along contour line. Through the estimation of tree layer biomass of single Pinus massoniana, the determination of the carbon storage in the tree layer of Pinus massoniana, the estimation of the understory shrub, the grass layer, and the wood layer, the determination of carbon storage in vegetation and litter layer under forest, the determination of organic carbon content and carbon storage in the sample, and the carbon storage of the plantation ecosystem of different stand density sample plots, the effects of stand density on biomass and carbon storage of Pinus massoniana plantation were analyzed. Results: The results of average carbon storage per unit area of Pinus massoniana plantation was different stand densities are 94.11 t/tm2 (1679 plants t/hm2), 79.06 t/tm2 (2250 plants / hm2), 73.32 t/tm2 (2800 plants / hm2). With the increase of stand density, the proportion of carbon storage in Pinus massoniana plantation decreased. This is because the larger the stand density, the more trees with small and medium diameter are grown in the Pinus massoniana plantation. The average diameter at breast height of the stand is very small, and the biomass of single tree decreases. The density is most beneficial to the improvement of the carbon storage of the tree layer. Conclusions: Density regulation promotes the accumulation of carbon storage of the Pinus massoniana plantation and increases the carbon storage of understory vegetation, litter, and soil layer.</p>

Enhancing the bone healing on electrical stimuli through the dental implant

Purpose The aim of this study was to evaluate the influence of different density and amplitude of electric current on the percentage of bone-implant contact (BIC) using the finite element method. Materials and Methods Numerical models were performed on commercially pure titanium grade IV implants connected to a 1.5 V battery with an electrical resistance (R) at 150 kΩ on 10 µA or at 75 kΩ on 20 µA. The percentage of simulated BIC was analysed by varying the electric current from 1 up to 60 µA. The variation of electric current application was simulated for coronal and apical peri-implant regions. Results The findings showed that a direct and constant electric current source below 10 μA does not provide a proper current density for osseointegration (BIC < 55%). Electric current sources ranging from 10 to 20 μA resulted in an increase in BIC above 60% while BIC reached 90% on 30 to 40 μA. Also, the application of the current source on 20 μA at the apical peri-implant region resulted in a high BIC percentage at around 86.1%. Conclusions The location and intensity of the electrical current source can increase the resultant electrical current density at the implant-bone interface and enhance the bone healing process. Although the model is a simplified version of the biological process in the bone-implant interface, such findings can predict a magnitude of electrical current density required to stimulate osseointegration.

Rotor strength analysis for high‐speed segmented surface‐mounted permanent magnet synchronous machines

This study is concerned with the unified analytical solution of rotor strength for the segmented permanent magnet (PM) rotor retained by the carbon-fibre sleeve and non-magnetic alloy sleeve in high-speed surface-mounted permanent magnet synchronous machine. Considering the influence of different densities and coefficients of thermal expansion of PMs and pole fillers on rotor stress, the analytical solution for rotor strength was proposed based on displacement method and stress potential method in polar coordinate. The proposed analytical solution was validated by the finite-element method (FEM) and experiment, respectively, and the influences of rotational speed, retaining sleeve thickness and interference fit between the retaining sleeve and PMs on rotor strength were further investigated based on the analytical solution proposed. It is shown that the results calculated by the proposed analytical solution and the FEM are in good agreement with each other, and the analytical solution can accurately predict the stress distributions of the segmented PM rotor retained by the carbon-fibre sleeve and non-magnetic alloy sleeve. The difference in density and coefficient of thermal expansion between PM and pole filler, rotational speed and operating temperature have great effects on rotor strength.

Influence of Sugarcane Straw on Aminocyclopyrachlor Leaching in a Green-Cane Harvesting System

The straw on the soil in the green cane harvesting system acts as a physical barrier to the action of the pre-emergence herbicides. However, some herbicides have physico-chemical characteristics to pass through the straw in water solution. The aim was to evaluate the influence of different densities of sugarcane straw on the leaching of aminocyclopyrachlor in a tropical soil (Oxisol—Typic Hapludox) in a system of green cane harvesting. The experiment was carried out using glass columns filled with soil, with and without sugarcane straw (0, 5, 10, and 20 t ha−1) on the top of the soil. 14C-aminocyclopyrachlor was applied followed by 200 mm of simulated rain for 48 h. The herbicide was detected in all soil layers (0–30 cm), and in the leachate (> 30 cm), in small trace amounts (≤ 0.21%) in all treatments, showing that aminocyclopyrachlor undergoes a high degree of leaching in the clayey soil. In the absence of straw, 39% of the herbicide remained in the upper layer (0–5 cm). In the presence of straw, the herbicide was distributed through the soil profile, mainly from 0 to 25 cm. Forty percent more herbicide was retained in the straw with 20 t ha−1 of sugarcane straw. Thus, it is concluded that the straw in high amounts retains aminocyclopyrachlor, but does not prevent it from reaching the soil; the high solubility of the herbicide and intense rainfall in a short period of time are factors that contribute to the herbicide passing through this barrier.

The releasing characteristics of carbon, nitrogen and phosphorus from sediment under the influence of different densities of algal detritus

The releasing characteristics of carbon, nitrogen and phosphorus from sediment under the influence of different densities of algal detritus

A FAST AND ROBUST ALGORITHM FOR ROAD EDGES EXTRACTION FROM LIDAR DATA

Fast mapping of roads plays an important role in many geospatial applications, such as infrastructure planning, traffic monitoring, and driver assistance. How to extract various road edges fast and robustly is a challenging task. In this paper, we present a fast and robust algorithm for the automatic road edges extraction from terrestrial mobile LiDAR data. The algorithm is based on a key observation: most roads around edges have difference in elevation and road edges with pavement are seen in two different planes. In our algorithm, we firstly extract a rough plane based on RANSAC algorithm, and then multiple refined planes which only contains pavement are extracted from the rough plane. The road edges are extracted based on these refined planes. In practice, there is a serious problem that the rough and refined planes usually extracted badly due to rough roads and different density of point cloud. To eliminate the influence of rough roads, the technology which is similar with the difference of DSM (digital surface model) and DTM (digital terrain model) is used, and we also propose a method which adjust the point clouds to a similar density to eliminate the influence of different density. Experiments show the validities of the proposed method with multiple datasets (e.g. urban road, highway, and some rural road). We use the same parameters through the experiments and our algorithm can achieve real-time processing speeds.

A FAST AND ROBUST ALGORITHM FOR ROAD EDGES EXTRACTION FROM LIDAR DATA

Abstract. Fast mapping of roads plays an important role in many geospatial applications, such as infrastructure planning, traffic monitoring, and driver assistance. How to extract various road edges fast and robustly is a challenging task. In this paper, we present a fast and robust algorithm for the automatic road edges extraction from terrestrial mobile LiDAR data. The algorithm is based on a key observation: most roads around edges have difference in elevation and road edges with pavement are seen in two different planes. In our algorithm, we firstly extract a rough plane based on RANSAC algorithm, and then multiple refined planes which only contains pavement are extracted from the rough plane. The road edges are extracted based on these refined planes. In practice, there is a serious problem that the rough and refined planes usually extracted badly due to rough roads and different density of point cloud. To eliminate the influence of rough roads, the technology which is similar with the difference of DSM (digital surface model) and DTM (digital terrain model) is used, and we also propose a method which adjust the point clouds to a similar density to eliminate the influence of different density. Experiments show the validities of the proposed method with multiple datasets (e.g. urban road, highway, and some rural road). We use the same parameters through the experiments and our algorithm can achieve real-time processing speeds.

Soja M-8527 RR consorciada com braquiária piatã em diferentes densidades e épocas de semeadura

O cultivo consorciado de culturas para grãos e forrageiras gramíneas é uma das práticas de integração lavoura-pecuária com elevado potencial para maximizar o sistema produtivo. Este trabalho teve o objetivo de avaliar a influência de densidades e épocas de semeadura de Brachiaria brizantha cv. BRS Piatã na produtividade do cultivar de soja M-8527 RR semeado em consórcio. O delineamento experimental foi em blocos casualizados, em esquema fatorial de 2 x 5 (duas épocas de semeadura de B. brizantha: 20 e 30 dias após a emergência da soja; e cinco densidades de semeadura da braquiária: 0, 3, 6, 9 e 12 kg de semente ha-1), com quatro repetições. Os seguintes parâmetros foram avaliados nas plantas de soja: altura, massa seca da parte aérea e produtividade de grãos. As variáveis avaliadas foram influenciadas pelas densidades e pelas épocas de semeadura de B.brizantha. Independentemente da época de semeadura da braquiária, todas as densidades a partir de 3 kg ha-1 promoveram redução na produtividade da soja; contudo, ela foi superior a 5% somente na densidade de 12 kg h-1,semeada aos 30 DAE, e nas densidades de 9 e 12 kg ha-1,semeada aos 20 DAE. O efeito competitivo da variedade de soja RR M-8527 foi superior quando Brachiaria brizantha cv. Piatã foi semeada aos 30 dias após a emergência da cultura.

One-Dimensional Vertical Infiltration Characteristics of Red Loam

Using a soil column experiments to analyze the influence of different density of one dimension vertical infiltration of water infiltration rate, cumulative infiltration and wetting front. The experimental results showed that the bulk density of the infiltration rate, cumulative infiltration and wetting front has a significant impact. Infiltration rate, cumulative infiltration and wetting front were decreased with increasing density in the same period of infiltration. The greater the soil bulk capacity, the larger the infiltration decrease ration μ and η, respectively compared to the based accumulative infiltration and the based wetting front depth.

The economic yield evaluation and some of the morphological traits of chickpea cultivars under the influence of different densities

In order to study yield and yield components of three chickpea genotypes at different plant densities under dry land conditions, a Field experiment was conducted during 2013 at the Research Farm of the Islamic Azad University of Kermanshah. The experimental design was factorial based on randomized complete block design with three replications. Five plant density (10, 20, 30, 40 and 50 plant/m 2 ) and three chickpea cultivars (ILC482, Arman and Flip84-48C) were factors which studied. Results showed that effect of plant density on grain yield was significant at 1% level. With increase of plant density from 10 to 30 plant/m 2 , grain yield increased and from 30 to 50 plant/m 2 , grain yield decreased, the reason of this was competition and shading of plants in surface unit. The highest yield (1033.1 Kg/h) was achieved in 30 plant/m2. Effect of cultivar on grain yield was significant at 5% level. The highest yield (1011.2 Kg/h) was achieved with ILC482 cultivar. With increase of plant density plant height increased but number of pod in plant, number of grain in plant, number of primary branch, number of secondary branch and hundred seed weight decreased. Plant density had no significant effect on number of seed per pod. The highest number of pod in per plant and plant height and lowest seed weight belonged to ILC482 cultivar. Arman cultivar had maximum seed weight. Effect of cultivar on seed per pod was not significant. In order to sowing of Chickpea in the area we predicate use from ILC482 cultivars with density of 30 plant/m 2

The Growth Charactersitics Study of Introduction Fast-Growing Poplar at the Initial Stage of Afforestation

We have carried out three consecutive years of tree growth survey, and studied on afforestation technology, compatibility and high-yielding measures, we conducted two-factor effect analysis of different varieties and different density on seedling height and ground diameter in the annual introduction of fast-growing poplar. The results showed that the influence of different varieties of seedling height and ground diameter was extremely significant, and the influence of different density of seedling height and ground diameter was not significant basically. Based on the above results, it can be preliminarily determined the most suitable fast-growing poplar and planting density for Inner Mongolia Daxinganling Forest Region.

Comportamento de cultivares de mamona (Ricinuscommunis) sob diferentes densidades populacionais, no estado do Tocantins

The castor bean (Ricinus communis L.) is an important oilseed for producing oil that is the primary raw material for biodiesel production and to be tolerant to drought. This paper aimed to evaluate the influence of different densities on agronomic characteristics of four cultivars of castor oil. The experiment was carried out at Federal University of Tocantins, in Gurupi – TO. The production of four cultivars was evaluated. Sowing was performed using four population densities (5,600, 7,400, 11,000 and 22,000 plants ha-1). The experiment was conducted under randomized blocks design, in 4 x 4 factorial schemes. The data were analyzed using variance analysis and the Tukey test was applied, at 5% probability. The results showed that the castor bean cultivars respond positively to the increase in population density. It is possible that maximum productivity was found in higher densities.

Influence of the Fibroblastic Reticular Network on Cell-Cell Interactions in Lymphoid Organs

Secondary lymphoid organs (SLO), such as lymph nodes and the spleen, display a complex micro-architecture. In the T cell zone the micro-architecture is provided by a network of fibroblastic reticular cells (FRC) and their filaments. The FRC network is thought to enhance the interaction between immune cells and their cognate antigen. However, the effect of the FRC network on cell interaction cannot be quantified to date because of limitations in immunological methodology. We use computational models to study the influence of different densities of FRC networks on the probability that two cells meet. We developed a 3D cellular automaton model to simulate cell movements and interactions along the FRC network inside lymphatic tissue. We show that the FRC network density has only a small effect on the probability of a cell to come into contact with a static or motile target. However, damage caused by a disruption of the FRC network is greatest at FRC densities corresponding to densities observed in the spleen of naïve mice. Our analysis suggests that the FRC network as a guiding structure for moving T cells has only a minor effect on the probability to find a corresponding dendritic cell. We propose alternative hypotheses by which the FRC network might influence the functionality of immune responses in a more significant way.

ВЛИЯНИЕ НА РАЗЛИЧНИ ПЛЪТНОСТИ НА БАЛУРА (SORGHUM HALEPENSЕ (L.) PERS) ВЪРХУ ДОБИВА ОТ СРЕДНО РАННИ И КЪСНИ СОРТОВЕ КАРТОФИ

ВЛИЯНИЕ НА РАЗЛИЧНИ ПЛЪТНОСТИ НА БАЛУРА (SORGHUM HALEPENSЕ (L.) PERS) ВЪРХУ ДОБИВА ОТ СРЕДНО РАННИ И КЪСНИ СОРТОВЕ КАРТОФИ

Influence of Parasitoid-Host Density on the Behaviour Ecology of Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), a Parasitoid of Opisina arenosella Walker

Since Goniozus nephantidis (Muesebeck) is found to have strong parental care for its progeny, the influence of different densities of G. nephantidis and its host, Corcyra cephalonica (Stainton) on the behaviour ecology of the parasitoid was studied. Interaction between different densities of the host and parasitoid revealed that a ratio of 1:1 was significantly superior to all other ratios resulting in maximum parasitism (9.0 larvae / female), fecundity (93.2/female) and number of progenies (75.2/female). Exposing more than one C. cephalonica larva did not significantly increase the parasitizing efficiency, fecundity and progeny produced. Conversely, exposing a single C. cephalonica larva to several female parasitoids adversely affected the biological attributes of the parasitoid. Increasing the densities of either host insects or parasitoids had an inverse relationship with oviposition behaviour, parasitism efficiency and progeny production of the parasitoid establishing the important and significant role played by host-parasitoid density.

Influence of Parasitoid-Host Density on the Behaviour Ecology of Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), a Parasitoid of Opisina arenosella Walker

Since Goniozus nephantidis (Muesebeck) is found to have strong parental care for its progeny, the influence of different densities of G. nephantidis and its host, Corcyra cephalonica (Stainton) on the behaviour ecology of the parasitoid was studied. Interaction between different densities of the host and parasitoid revealed that a ratio of 1:1 was significantly superior to all other ratios resulting in maximum parasitism (9.0 larvae / female), fecundity (93.2/female) and number of progenies (75.2/female). Exposing more than one C. cephalonica larva did not significantly increase the parasitizing efficiency, fecundity and progeny produced. Conversely, exposing a single C. cephalonica larva to several female parasitoids adversely affected the biological attributes of the parasitoid. Increasing the densities of either host insects or parasitoids had an inverse relationship with oviposition behaviour, parasitism efficiency and progeny production of the parasitoid establishing the important and significant role played by host-parasitoid density.