Seal Area Research Articles

Performance optimization of vessel sealing using a hemostatic ultrasonic scalpel.

Using ultrasound technology as one of the therapeutic methods, in which ultrasound waves of different frequencies and intensities are employed, has significantly contributed to enhancing and facilitating the treatment process of various diseases. A Hemostatic Ultrasonic Scalpel can entail considerable advantages by simultaneously performing two operations tissue cutting and coagulation of biological tissues. In the present study, employing experimental design through response surface methodology, the effect of ultrasonic power and the duration of vibration application on the tissue has been investigated. Two parameters, namely the burst pressure of the sealed vessel and the length of the thermal seal zone, were measured by pressure testing and analysis image of the thermal effect region at the sealed vessel area, respectively. The pressure test results demonstrated that an input power of 52 W and the application of vibrations for 8 s under a constant force of 10 N, showed the optimized maximum burst pressure equal to 1100 mmHg. Examination of the sealed vessel images revealed a linear increase in thermal damage with increasing input power.

The performance of two urban flood regulation models using different input data

Increasing climate change has led to an increase in urban flood events. Events with a return period of twenty years become events with a period of two to three years. The primary objectives of this study are to evaluate the performance of flood regulation models using different input data and compare their performance for flood regulation supply (FRS) assessment. The assessment of the ecosystem services of urban FRS was performed using two models: Urban Flood Risk Mitigation (UFRM) by Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and IMECOGIP Waterflow Regulation (Retention Model) (WRRM). They rely on relatively accessible open-source data, require a short time to model each scenario and provide opportunities to interpret results in different spatial and measurement units. We performed several improvements to the input data, including updating the national ecosystem-type assessment for the case study area by connecting it with the Urban Atlas typology and proposing an approach for soil data refinement. The outputs of the two models show significant differences in FRS values for each land-use/land-cover (LULC) class. The UFRM assesses different impervious urban classes with different values, varying from very low to medium. In contrast, the WRRM assesses the FRS in densely sealed areas with one fixed value for low supply (where nearly all rainfall is transformed into runoff).

Effect of pre-oxidation and cooling process on characteristics and mechanism of the coal re-ignition

Based on the engineering background that the sealed fire area is easy to reignite, the reignition characteristics of pre-oxidized coals (POC) after cooling are studied. Predecessors mainly explain this problem from the perspective of pre-oxidation affecting coals pore structure. This paper analyzes the effects of different pre-oxidation temperatures and cooling atmospheres on coal physical and chemical structure. The changes of coals during oxidation-cooling-reoxidation were studied by means of a programmed heating device, low temperature nitrogen adsorption experiment, FTIR and quantum chemical calculation. The results show that the average pore size of the coal cooled in nitrogen at the same pre-oxidation temperature is smaller than that of the coal cooled in dry air, while the spontaneous combustion characteristics of the coal cooled in nitrogen are stronger than those of raw coal, and spontaneous combustion characteristics of coal cooled in air are the opposite. The oxygen-containing functional groups of the coal cooled in nitrogen are pyrolyzed to produce active sites which can exist stably in nitrogen. Then, the rationality of “The active sites tend to be alkyl radical” is analyzed and speculated by molecular orbital theory, and it's found that alkyl radicals can release lots of heat at 30 °C.

Urban pavements as a novel habitat for wild bees and other ground-nesting insects

AbstractMunicipal authorities around the world have come to recognize the importance of making conservation and restoration a priority. Multiple urban restoration programs now foster insects and other pollinators through planting and sowing flowering plants, many of them within residential areas. But residents are not only walking next to pollinators visiting flowering sidewalk grass verges, they are also walking on top of them, nesting in the cracks and interstices of urban pavements.Combining morphological and molecular monitoring schemes, we conducted a survey of urban pavements at twelve locations across Berlin and found that pavements can foster a surprising number and quantity of soil dwelling insects—in particular wild bees and wasps. Pavements located within 200 m to an insect-friendly flower garden were covered with significantly more nests of wild bees and solitary wasps, and showed higher species richness of these groups, while the degree of sealed surfaces in the surrounding had no effect per se. This underlines the positive impact that insect-friendly gardens can have for pollinators and other insects, even in highly sealed areas. Also, it shows the potential of cobbled pavements as valuable nesting sites in highly sealed urban areas. We provide a list of 55 species of ground-nesting Hymenoptera found in Berlin pavements, including 28 species of wild bees and 22 apoid wasps. In our study, the molecular approach only detected three Hymenoptera species and did not yield comparable results to classical monitoring. Nonetheless, using eDNA methods might be a promising tool for further studying soil nesting insects in the future, and to gain insights into the web of life in urban pavements.

On setting boundary conditions for calculations of turbomachines in 3-d computer packages

Unfortunately, in a growing number of publications of the results of the study of turbomachines in ANSYS and other packages, insufficient attention is paid to the choice of the flow model (absolute or relative) and the setting of boundary conditions in the areas adjacent to the rotating impeller: shroud seal, diaphragm (end) seals, gap over shroudless blades, steam balance holes, etc.As a rule, these areas contain such elements of geometry as a “ledge”, “projection”, “crest”, the flow around which, and, consequently, their resistance depends on the angle of incoming flow relative to the barrier. In the stages of turbomachines in sections behind fixed blade units, angle α1 between the flow velocity vector (in absolute motion) and the circumferential velocity is 10°÷25° (for steam turbine stages), 20°÷35° (for gas turbine stages) and 40°÷75° ((for axial compressor stages). It is shown (using the example of viscous flow around the “ledge + projection” system) that a change in the angle in the range of 15°÷90° changes the resistance by almost 2 times.The choice of a particular type of flow model (absolute or relative) for the domain primarily determines the value of the angle of interaction of the flow lines with an obstacle: it remains close to α1, or close to β1 = α1 + 20°÷70°, which significantly changes the qualitative picture of the viscous flow around the characteristic elements of geometry (“ledge”, “projection”, “crest”), and the values of integral parameters (flow rate, power, efficiency). The lack of recommendations on the correct choice of boundary conditions will inevitably lead not only to the inability to compare the results of various published studies, but also to their objective value. Therefore, the need to substantiate proposals for the choice of flow models in the areas of labyrinth seals, steam balance holes, gaps over shroudless blades, etc. is very relevant.

Cenostigma pluviosum Tree Stem Growth and Carbon Storage in a Subtropical Urban Environment: A Case Study in Sao Paulo City

Our aim is to contribute to understanding the role of subtropical trees on carbon storage and CO2 removal in the city of Sao Paulo/Brazil, besides highlighting the surrounding environment implications to sibipiruna trees (Cenostigma pluviosum)’s performance. The case study was conducted with three trees, one planted on a sidewalk in Pinheiros neighborhood, a highly sealed area, and two in a green area, the Ibirapuera Park. To define the stem basal area growth and its pattern, local measurements were taken over a year and a segmented linear regression model was adjusted. The stem growth dependency on microclimate was tested by a Spearman Correlation. The trees’ active stem growth presented a similar pattern. The soil volumetric water content and soil temperatures were the variables with more impact. The total mean radial stem growth for the IBIRA1 and IBIRA2 trees was 1.2 mm year−1 and 3 mm year−1, while at PIN1 it was 1.3 mm year−1. The total biomass increment in IBIRA1 and IBIRA2 was 4.2 kg C year−1 and 12.8 kg C year−1, while in PIN it was 4.9 kg C year−1 and the removal was 15.3 C year−1, 47.1 kg CO2 year−1 and 17.9 kg CO2 year−1, respectively. The results indicated that the land cover difference implies a significant interference with the promotion of carbon fixation and CO2 removal, demonstrating that planting urban trees in soils with better water storage conditions is more efficient.

Impact of land-use on PAH transfer in sub-surface water as recorded by CaCO3 concretions in urban underground structures (Paris, France)

In densely populated urban areas, the pressure on water resources is considerable and will tend to intensify over the next decades. Preserving water resources therefore seems fundamental, but many questions remain as to the transfer of contaminants to subsurface waters in these largely sealed areas. Because of their toxicity and persistence in the environment, this work focused on the study of polycyclic aromatic hydrocarbons (PAHs), ubiquitous pollutants mainly produced by human activities. To better understand the main factors leading to the retention or transport of these pollutants in urban environments, vertical transects, from the surface to several meters down, were established on three study sites in or near Paris (France), selected according to an urbanization gradient. Soil samples collected at the surface and urban secondary carbonate deposits (USCD), similar to cave speleothems, sampled underground in quarries and aqueducts were analyzed. As the hydrophobic properties of PAHs favor their sorption onto organic matter, the latter was also studied using organic carbon analysis and UV fluorescence spectroscopy. The USCD located closest to the urbanized surface contained high concentrations of PAHs (76.8 ± 5.3 ng g−1), while the USCD located at greater depth with organic soil on the surface contained the lowest amount of PAHs (2.9 ± 0.4 ng g−1), and no PAHs with log KOC > 5. The results highlight the predominant role played by the presence of organic topsoil at the surface in retaining and storing large amounts of PAHs (1914–2595 ng. gsoil−1), particularly the most hydrophobic ones (i.e. 60% of the 15 PAHs are characterized by a Log KOC >5), which are also the most toxic. The lithology and thickness of the bedrock (between the surface and the USCD) also play an important role in the retention of PAHs, particularly those adsorbed on the particulate phase.

IMPACT OF ACARICIDES ON VARROA DESTRUCTOR INFESTATION IN HONEY BEE COLONIES (Apis mellifera L.) AND THEIR HISTOLOGICAL EFFECTS ON HYPOPHARYNGEAL GLANDS

This study aimed to determine the random role of some acaricides, which are the most commonly used in Egypt for controlling Varroa destructor on Hypopharyngeal Glands (HPGs) of honey bees (Apis mellifera L.). The acaricides used in this study were Varroakiller®, Menthocaros®, Amitraz®, Varroby®, and formic acid. Results showed that the total number of fallen mites was 53.5, 47, 28.6, 26, and 24.5 for Varroakiller®, Menthocaros®, Amitraz®, Varroby®, and formic acid, respectively, compared to 16 mites in the control group. For sealed worker brood areas (SWBA), the treatments included Varroakiller® (327.98 cm2), formic acid (228.92 cm2), Varroby® (222.25 cm2), Menthocaros® (129.72 cm2), and Amitraz® (101.73 cm2), while the SWBA for control colonies was 44.83 cm2. Histological studies of the HPGs showed that although Varroakiller® effectively controlled Varroa mites and had no direct impact on worker bees or egg-laying areas, it considerably impacted the HPGs, which could ultimately affect the bee colony. Moreover, formic acid recorded a lower number of fallen Varroa with acceptable outcomes for egg-laying areas and sealed workers. This, coupled with the fact that formic acid was deemed the most significant due to its effectiveness over a short period, resulted in a reduction of 100% after 24 days.

Monitoring Urban Heat Island Spatial Variability over Urban Structure Types – A Case Study from a Fast-growing City in the Vietnamese Mekong Delta

This study aims to assess the variation in the temperature patterns for different urban structure types (USTs) in Can Tho City, Vietnam. The study involves extracting thermal infrared data from Landsat imagery to determine the Land Surface Temperature (LST). Surface Urban Heat Island (SUHI) intensity is then calculated by analyzing the temperature differences between urban and non-urban areas. An overlay method was applied to analyze the variations in SUHI intensity within four distinct USTs categories: residential (R), public and special use (P), industrial (I), and green and open spaces (G), as defined based on 53 USTs derived in original data. The results highlight that the highest SUHI intensity was primarily concentrated in the industrial (I) areas, covering over 50% of the region, while residential (R) and public and special use (P) areas exhibited moderate SUHI intensity. Although the green and open space (G) category had a substantial area of open space, it still experienced a low-intensity SUHI, mainly concentrated in heavily sealed areas. This study provides valuable insights into the presence of SUHI in contemporary, rapidly developing cities. It underscores the significance of understanding and addressing SUHI issues, particularly useful for the real-world planning of urban environments.

Simulation on Harmful Gas Control by Balanced Pressure Ventilation in the Fully Mechanized Caving Face under Sealed Fire Area of Small Coal Mine.

The harmful gas in the sealed fire area of a small coal mine rushes into the mining face of the lower coal seam, which restricts the efficient promotion of the working face. In this paper, based on the evolution law of caving coal rock dilatation coefficient, the characteristics of the heterogeneous distribution of permeability and voidage in goaf were obtained, and the mathematical model of gas migration in goaf is constructed. The numerical solution of gas migration in goaf under the sealed fire area of a small coal mine was realized by using the Free and Porous Media Flow module and the Transport of Dilute Matter in Porous Media module in COMSOL Multiphysics, and the corresponding measure was proposed. The results show that the fresh air flows into the goaf from both the inlet air roadway and the working face and then flows out from the upper corner. Driven by the air flow, the CO in the overlying sealed fire area of a small coal mine flows out from the upper corner of the working face, resulting in the CO overlimit. Due to the influence of air leakage and the CO overlimit in the working face, low oxygen occurs in the working face. According to the characteristics of gas emission, balanced pressure ventilation technology is proposed to control the low oxygen in the working face and the CO overlimit in the upper corner. It is found that the balanced pressure ventilation obviously increases the pressure of the working face, reduces the pressure difference between the two ends of the working face by 45.7-26.7%, and decreases the air leakage to the goaf in the upper corner of the inlet air roadway. The field application shows that the problems of low oxygen in the working face and a CO overlimit in the upper corner are effectively solved.

Improving the Retention of Maxillary Complete Denture: A Case Report

Complete dentures play an essential role in restoring oral function and improving the quality of life for individuals who have missing all their normal teeth. One of the key factors determining the success of complete dentures is their retention, which refers to the ability of dentures to stay securely in place during normal oral function. Adequate retention is essential for proper speech, mastication and overall comfort of the denture wearer. The study aimed to improve the retention of complete dentures through three different approaches: spacer, posterior palatal seal area, and undercut area. Three dentures were fabricated using the same steps, with variations in certain steps based on the retention technique being employed. The study showed that all three dentures had improved retention compared to standard complete dentures. The dentures that included the posterior palatal seal area and spacer demonstrated higher retention than the denture that employed the undercut technique. It is worth noting that the patient did not find the denture with the undercut technique satisfactorily.

Increased Mass-Rearing of Queens in High Royal-Jelly-Producing Honey Bee Colonies (Apis mellifera ligustica) Generates Smaller Queens with Comparable Fecundity

The mass rearing of high-quality queen bees is an essential beekeeping practice for producing new queens to maintain colony productivity. A strain of high royal-jelly-producing bees (RJBs; Apis mellifera ligustica) in China exhibits high potential for the rapid mass rearing of queens. To explore the potential changes in the quality of mass-reared queens, a set of morphometric traits and the sealed brood area were compared between the queens reared from 64 and 320 queen cells in RJB colonies. The increase in the queen cell number was found to induce a slightly but significantly reduced body weight and smaller wing length and thorax width in the reared queens at emergence. However, the ovariole number and sealed brood area, an indicator of the queen fecundity, were not observed to be significantly influenced. With respect to body weight and ovariole number, all the reared queens satisfied the current criteria for high-quality queens. Our findings provide evidence for the efficient mass production of high-quality queens using RJB colonies.

A potential role for inflammatory cytokines in a rare late-onset capsular block syndrome: a case report

BackgroundLate-onset capsule block syndrome (CBS) is a rare complication of cataract phacoemulsification and the implantation of a posterior chamber intraocular lens (PCIOL), which manifests six months to years after surgery. The hallmark of CBS is the formation of an opaque liquid substance between the implanted intraocular lens (IOL) and the posterior capsule. However, its pathogenesis remains unclear.Case presentationA 64-year-old female patient with chronic angle-closure glaucoma (axis length < 21 mm) underwent trabeculectomy surgery combined with phacoemulsification and PCIOL. After a 4-year follow-up, a decline in visual acuity occurred in her right eye due to the location of opaque fluid in the visual axis and distension of the capsular bag. The initial course of action was to release the trapped fluid. Neodymium: yttrium-aluminum-garnet (Nd: YAG) laser capsulotomy could not be employed due to her non-dilating pupil and high extension of the posterior capsule. Subsequently, anterior capsule peeling and anterior segment vitrectomy surgery were performed. The depth of the anterior chamber (ACD), the distance between the face of the retro-IOL and the posterior capsule, the best-corrected visual acuity (BCVA), and the visual quality (VQ) were measured both before and after surgery. Inflammatory cytokine levels in the opaque substances (OS) trapped between the PCIOL and the posterior capsule were assessed using a flow cytometer and compared to normal statistical data in aqueous humor. After surgery, the patient experienced a significant improvement in BCVA and VQ. The distance between the face of the retro-IOL and the posterior capsule was on the verge of disappearing. However, ACD did not differ between pre- and post-operatively. Interleukin-8 (IL-8) and basic fibroblast growth factor (BFGF) concentrations were higher in the OS than in aqueous humor, especially in the former. However, the concentration of vascular cell adhesion molecule (VCAM) in the OS was lower than in aqueous humor.ConclusionsAnterior segment vitrectomy surgery proved to be a successful treatment for late-onset CBS, presenting a challenging case. In the human lens, inflammatory cytokines originating from the opaque substances may contribute to abnormal metabolism in the sealed area, a consequence of late-onset CBS.

Comparison of pure caucasian, carniolan and native anatolian ecotype honey bee (Apis mellifera L.) colonies in the eastern anatolia region with reciprocal F1 hybrids

The aim of this study was to compare specific physiological and behavioral characteristics of A. m. caucasica, A. m. carnica, and native honeybees, as well as reciprocal crosses, within the ecological conditions of East Anatolia (Van province), Turkey. The findings revealed that native honeybees exhibited the highest average sealed brood area and the highest average number of frames with bees. In contrast, the highest average honey yield was observed in the crossbreeding of Carniolan bees with native bees. Significant differences were identified among the groups concerning brood area, the number of bee frames, aggression tendency, and honey yield. The study concluded that Carniolan and Caucasian bees exhibited suboptimal performance outside their native habitats. Nevertheless, Carniolan bees were identified as a viable option for mitigating aggression tendencies and enhancing honey yield in native bee populations.

Research on the Hydraulic Excitation Characteristics of the Top Cover Caused by the Radial Installation Deviation of the Seal of a 1GW Francis Turbine

The radial installation deviation of the turbine runner will change the gap flow between the upper crown and the lower ring seal, which will affect the radial force of the runner and the hydraulic excitation characteristics of the top cover. This research focuses on the 1GW Francis turbine on the right bank of the Baihetan hydropower station. The pressure distribution along the circumference of the top cover was analyzed, and the effects of deviations on the specific generation of hydraulic excitation forces were studied. This research shows that the increase in radial deviation will slightly reduce the output and efficiency, and the radial force on the runner increases parabolically. When the radial deviation is 1.5 mm, the radial force is 5.9 times higher compared to the case without any deviation, and the radius of the fitting circle of the radial force behavior trajectory increases with the increase in radial deviation. In addition, the radial deviation has little effect on the internal flow of the runner and the pressure distribution in the upper crown chamber. The dominant frequency components at the upstream monitoring points include fn, 15 fn, 24 fn, and 30 fn. The dominant frequency components at the downstream monitoring points include the blade passing frequencies of 15 fn and 30 fn. However, with the increase in radial deviation, the fluctuation amplitudes exhibit an asymmetric distribution, the uniformity of the pressure distribution in the circumferential direction of the labyrinth seal area becomes significantly worse, and the waveform of the downstream monitoring points changes significantly and presents a non-uniform distribution in one rotation cycle.

Challenges for Flood Risk Reduction in Poland’s Changing Climate

Floods are the main natural disaster in Poland, and the risk of both fluvial and pluvial floods is serious in the country. Pluvial floods are on the rise in the changing climate, particularly in increasingly sealed urbanized areas. In this paper, we examine the changes in flood risk in Poland, discussing the mechanisms, observations, projections and variability. Next, we discuss flood risk management in the country, including specific issues related to urban and rural areas and the synergies between flood and drought risk reduction measures. We identify and assess the weaknesses of the existing flood risk management plans in Poland for the first planning period 2016–2021 and for the second planning period 2022–2027. We find the level of implementation of plans in the former period to be very low. Many planned measures do not have much to do with flood risk reduction but are often linked to other objectives, such as inland navigation. The plans contain numerous small measures, which come across as inapt and economically ineffective solutions. We specify policy-relevant recommendations for necessary and urgent actions, which, if undertaken, could considerably reduce flood risk. We also sketch the way ahead for flood risk management in Poland within the timeframe of the implementation of plans for 2022–2027 and the next regular update of plans for 2028–2033.

Evaluation of Distortion in the Posterior Palatal Seal Area of Maxillary Cast by Different Adaptation Techniques of Denture Bases.

To evaluate and compare the amount of distortion in the posterior palatal seal area in V-shaped and U-shaped palatal form of maxillary cast by different adaptation techniques of maxillary denture bases. A total of 60 stone casts were made, out of which 30 identical stone casts of U-shaped palatal form and 30 identical stone casts of V-shaped palatal form of maxillary casts were prepared. The 30 stone casts of U-shaped palatal form and 30 stone casts of V-shaped palatal forms were divided into three groups for measurements to be done. Data were statistically analyzed by using two-way analysis of variance (ANOVA) without replication. Discrepancies of fit of dentures on U-shaped casts and V-shaped casts of Groups 1, 2, and 3 in transverse and sagittal sections were measured, and comparative statistical analysis between Group 1&2, Group 1&3, and Group 2&3 was done for statistical significant values. Discrepancy in the central region was maximum, and the anchoring methods Group 2 and Group 3 produced a significantly better adaptation than the conventional method (Group 1). The adaptations for V-shaped palate were better when compared with U-shaped palate in the central region.

Study on lubrication characteristics of rotary combination seals under stress relaxation

Temperatures in the drilling environment can reach 150 °C and pressures up to 30 MPa, all of which can cause oil film rupture and even seal failure. In addition, under high pressure, viscosity changes can lead to stress relaxation, which may eventually cause seal failure as well. In order to study the influence of high temperature and high pressure conditions on seal performance during stress relaxation, the pressure permeation loading method on both sides is used in the finite element model to simulate the fluid pressure on both sides of the seal interface, and the TEHL (thermo-elastohydrodynamic lubrication) model of the rotary combination seal is also established. On this basis, the TEHL characteristics of the rotary combination seal under different working conditions were analyzed. The results show that: Firstly, the contact pressure and von Mises stress of the seal tend to increase at high temperature, and the higher the temperature, the faster the growth rate, while the increase of the seal area temperature leads to the thinning of the oil film thickness and the high oil film pressure. Secondly, at high fluid pressure, the contact pressure of the rotary combination seal gradually increases, and its peak is close to the peak oil-side contact pressure. Thirdly, with the increase of the linear speed (or rotational speed), the oil film pressure and thickness increase. Fourthly, the larger the rotational speed, the larger the volume leakage and friction, and the larger the compression ratio, the larger the contact pressure.

Observing the effect of pressure and temperature on the seal integrity of critical seal regions of various flexible bag designs

Folding geometry and the design of a flexible package cause pressure differences along sealing region during heat sealing. These differences might be one of the main reasons behind microchannels and leak formation at the seal area making it difficult to create hermetic packaging. In this article, the influence of changing pressure at different critical sealing regions such as folded corners, layer jumps, and seal intersections was examined via seal characterization methods and image analysis of the cross-section. According to the results, at the 2 layers folded corners pressure and temperature combinations above 2 bar and 130ºC do not cause insufficient sealing. However, at the layer jump points of 3 layers (lap seal) regions and 4 layers (gusset) regions, gaps inside the seal interphase persists at low temperature and low-pressure combinations below 140ºC and 4 bar. Additionally, when the temperature and pressure combination exceeds 160ºC and 4 bars some seal damages and squeeze-out problem is clearly observed in this seal regions. The optimum levels of temperature and pressure to minimize the interphase gap are different at each critical seal region for BOPP/metBOPET/CPP based multilayer packaging. Pressure increase positively influences the integrity of the seal for mentioned critical regions. However, it is discovered that above 150ºC, high-pressure levels (4–5 bars and higher) create a transition in the sealing characteristic from peel seal to lock seal. Additionally, squeeze out of the sealant polymer starts to occur at 3 bars for 150ºC sealing temperature. Squeeze-out problems can increase due to changing pressure distribution along the layer jumps and cause wrinkles as confirmed via visual observation of the sample packages from the industry. To sum up, it has been shown that pressure optimization based on the package design can improve seal integrity and help to prevent seal defects that lead to food quality and safety issues.

A COMPARATIVE STUDY ON THE QUALITY OF HONEY BEE (Apis mellifera) QUEENS DEVELOPED FROM LARVAE AFTER THE COLLECTION OF ROYAL JELLY

Rearing bee queens is almost done utilizing grafting young larvae while the effects of grafting using old larvae after the collection of royal jelly on the quality of queens are not known. In fact, the production of royal jelly depends on grafting, then discarding the larvae to collect the royal jelly. This study aimed to investigate this point by grafting old larvae after removing them from their original cells without food. Larvae at age about 2 days were grafted into plastic queen cell cups (selection and grafting method or S&amp;G method) leaving royal jelly behind and then resultant queens were compared with naturally reared ones (or NQ). The study showed the absence of significant variations between the queens reared from the two methods in characteristics of queens and cells. Meanwhile, no significant differences were found in regard to the performance of colonies. The colonies with queens from S&amp;G method had slightly higher performance than those with NQ. The study concluded that grafting using old larvae without their original food does not impair the quality of queens. During the production of royal jelly, larvae may be grafted into new cells to continue their normal development instead of discarding them.