Double Wall Research Articles

Study of changes in catalase activity in blood and liver of rats with experimentally induced dyslipoproteinemia against the background of mechanical damage to skeletal muscle

Purpose : to study the dynamics of catalase activity in the blood and liver liver tissues with oxidative stress caused by the modeling of dyslipoproteinemia with the subsequent mechanical trauma of the skeletal muscle. Materials and methods . The study was conducted on white, unconventional sexual healthy rags of six months of age, weighing 200-230 grams, in the amount of 120 pieces contained in standard conditions of vivarium. All animals were divided into four groups, 30 animals in each group. Animals of the first group are intact rats to which no effects were applied. Animals of the second group (regeneration control) had a mechanical dissection in the area of the middle third of the calf muscle of the posterior limb. Animals of 1 and 2 groups were on the standard diet of Vivaria and had free access to water and food. The animals of the third and fourth groups were first modeled by dyslipoprotein for 63 days. All this time, animals received a high -carb and high -fat diet with a weight of dry substances increased up to 30 % and replacement of drinking water with a 20 % fructose solution. After the specified time, the animals of the fourth group were injured by the middle third of the calf muscle of the posterior limb. The activity of catalase was investigated in animals before the start of the experiment, as well as on 1, 3, 5, 14, 21 days of experience according to the standard methodology of Queen M. A. The capture of the material and the removal of rats from the experiment was carried out with accurate observance of all ethical norms applicable to laboratory animals . Under etheric anesthesia, a blood fence was made, and then the liver fence, which was washed with physiological solution and frozen. Then, by mechanical grinding of fabrics weighing 1 g and mixing with 9 ml of Tris Bufer (pH 7.4), homogenates were prepared in an automatic homogen at a speed of 5,000 rpm in a vessel with double walls, constantly cooled by running water. Results . The mechanical trauma of the calf muscle and dyslipoprotemia contributed to the intensification of oxidative processes at the local and systemic levels of the body, but the combination of these facts was characterized by extremely intense oxidative stress and led to a decrease in the activity of catalase in the blood and liver tissues.

Diagnostics and surgical management of periampullary duodenal duplication cysts in children: a report of cases

BACKGROUND: Obstructive variants of chronic duodenal obstruction may be caused by congenital malformations, such as rare periampullary duodenal duplication cysts. This localization of gastrointestinal duplications is the rarest and is not described in the domestic literature.
 AIM: This study aimed to present the experience of the management of periampullary duodenal duplication cysts in children.
 CASES REPORT: Seven children with periampullary duodenal duplication cysts underwent surgery between 2007 and 2022. All patients suffered from prolonged abdominal pain, vomiting of food, and bile. Two children had recurrent pancreatitis, and one child underwent repeated operations for high intestinal obstruction and biliary obstruction in other hospitals. An abdominal cyst was suspected in one patient at another hospital, and the child underwent exploratory laparoscopy, but no formation was found. Ultrasound, gastroduodenoscopy, computed tomography, and magnetic resonance imaging were performed on these children. Ultrasound examination showed a peristaltic cystic formation up to 4 cm in diameter with a double wall. Gastroduodenoscopy showed formation in the second portion of the duodenum in the region of the major duodenal papilla. This formation covers the intestinal lumen by two-thirds and up to nearly complete obturation. The relationship between duodenal duplication and the bile and pancreatic ducts was clarified on magnetic resonance cholangiopancreatography: the relationship was suspected in two children. All patients underwent wide transduodenal excision of periampullary duodenal duplication cyst; in four cases, laparoscopic access was used. No intra- and postoperative complications occurred. Histological examination revealed true duplications in all cases. The children were discharged on days 1112. In the follow-up after 3 months and 10 years, no complications were noted.
 CONCLUSIONS: Periampullary duodenal duplication cysts can be a cause of chronic duodenal obstruction. Transduodenal excision of periampullary duodenal duplication cysts is the optimal treatment, and this operation can be performed laparoscopically.

A New Genus of the Zooproblematics of the Family Siphogonuchitidae

A new genus and species Monoshanites dentatus gen. et sp. nov. of asymmetric sclerites of problematic animal organisms belonging to the family Siphogonuchitidae is described from the Khevte–Tsakhir–Nuruu section of Western Mongolia (Tommotian Stage, Beds with Halkieria amorpha, Bayangol Formation). The microstructure of sclerites with a double wall was studied: the inner layer is lamellar, the outer layer is columnar.

이중 패널 벽체구조 무도류벽 원형 물탱크의 보강 및 구조 상세에 따른 거동특성 분석

이중 패널 벽체구조 무도류벽 원형 물탱크의 보강 및 구조 상세에 따른 거동특성 분석

Gamma radiation induced synthesis of double network hydrophilic cryogels at low pH loaded with AuNPs for fast and efficient degradation of Congo red

γ−radiation is a clean, fast and efficient synthetic route for polymeric materials. it is very powerful tool to generate free radicals during polymerization without any need of initiator and accelerator in both hydrophilic and hydrophobic media. Here in this work, for the first time, we fabricated acrylamide-methyl-propane sulfonic acid based-single and double network hydrophilic cryogels via γ−radiation at low pH. pH highly effects the synthesis of acrylamide-methyl-propane sulfonic acid based cryogels using redox initiation method. Along with pH, the effect of radiation time and radiation dose rate on cryo-polymerization was also studied. Gold hybrid cryogels (single and double network) were fabricated via self-reduction method at ambient conditions. Fourier transform infrared spectroscopy was implemented for chemical structure analysis of the synthesized material. The surface morphology of single and double network cryogels was observed via scanning electron microscopy. For the hybrid cryogels materials analysis x-ray diffraction, thermal gravimetric analysis, energy dispersive x-ray analysis, x-ray photoelectron spectroscopy and transmission electron microscopy and was used to confirm the presence of nanoparticles in the polymer network. The fabricated hybrid cryogels (0.15 g) were used for the degradation of Congo red (50 mL) as model dye in the presence of NaBH4 (0.02 g) with efficient and fast degradation activity. The apparent rate constant value (Kapp) for single and double network hybrid cryogels was 0.3652 min−1 and 0.2268 min−1, respectively. The activation energy, enthalpy and entropy was calculated (34.44 kJ.mol−1, –30.85 kJ.mol−1 and –146.30 J·mol−1k−1, respectively) using Arrhenius and Eyring equations for the fabricated catalyst. The catalyst was tasted in the tap water system and its efficiency was satisfied in real world too. The fabricated double wall hybrid catalyst will have a significant importance in the environmental field.

The strong influence of small construction errors on sound insulation of buildings with heavyweight concrete structure: A Portuguese case study

In order to attain an expected sound insulation in buildings, it is necessary to employ appropriated constructive solutions, but it is also fundamental to guarantee compatibility with other involved design professional fields, proper detailing of solutions and correct on site mounting. A solution with a predicted high acoustic performance may result in failure if there is no proper interconnection between other design professional areas or if execution mistakes occur, even if of very small dimension. The main objective of this technical paper is to analyse the influence of defects that typically occur in buildings, located in Portugal, resulting in very poor airborne or impact sound insulation performance. The chosen situations refer to buildings with heavyweight concrete structure, where small construction defects occurred and/or wrong decisions were taken, ending up with a large reduction on the final acoustic performance. Some of these errors, given their small size or because they occurred in hidden zones, easily passed unnoticed, on site. The defects here addressed in what refers to airborne sound insulation are related with execution of double masonry hollow brick walls, sound bridges in acoustic suspended ceilings, passage of ventilation or sewage pipes, inappropriate installation of acoustic doors, shutter boxes or windows. As for impact sound insulation, the presence of rigid connections is the main focus of the characterisation here performed.

Optimization computer network and bluetooth technology for parallel analysis of data transmission in programming

Technological problems and transmit data can be given a solution using Bluetooth technology. Bluetooth technology is used to transmit data over a distance of about 15 m. This data transmission analysis aims to apply and implement damping on the glass wall using a bluetooth device, in sending data files to replace the function of the data cable. So with this problem, a room that is partitioned using glass walls is designed and built. The hypotheses made: The material barrier factor between the master and slave greatly affects the attenuation of the received signal. In addition to the above factors, attenuation is also influenced by the distance between the master and slave. With two glass skate partitions and the distance between the master and slave will affect the data transfer speed. This study is to determine the attenuation of the double glass wall between the user and the server on the LAN network, using 15 PCs that are placed in a glass-insulated room on the same floor. The Bluetooth used is class 2 with a power of 2.5 m watts with a range of 15 m. The result of this research trial is that attenuation in a room with a glass wall in the room produces power losses, only experienced by the signal between the master and slave, the farther the distance the signal attenuation is, the greater the power losses, which results in more the amount of reduction in transfer rate from master to slave. Communication between computers through the use of USB. Bluetooth is only a simulation signal propagation. One room is used the floor is insulated by glass wall with size of 3m x 3m to measure the master room, 5 x 5m for the slave room. The distance between the server room and the slave room 3m.

Prediction of Deflection Due to Multistage Loading of a Corrugated Package

With the expansion of overseas markets, transportation distance, storage periods in warehouses, and traffic volume of goods are increasing. In this distribution environment, the safety problem due to the decrease in the strength of the multistacked corrugated package is becoming very important. This study aims to develop a CAE prediction technology for the height change of multistacked corrugated packages, and for this study, the FEA simulation method for existing corrugated packages has been investigated and supplemented. The four-point bending FE model and the box compression test FE model were also constructed based on the simplified and homogenized composite model for the target corrugated fiberboard (double wall of EB-flute) itself. Four-point bending, box compression, and creep tests were performed to obtain the material constant required for FEA simulation. Through the comparison of the F–D curve area between the test and the FEA simulation, parameter optimization that minimizes the area difference was performed using HyperStudy. The FEA simulation and stacking test for the multistacked target corrugated package were performed simultaneously on four actual stacking scenarios with different package weights and package sizes. A comparison of height changes after 72 h of stacking for each of the four scenarios showed that the concordance between the test and FEA simulation was more than 80% in all cases. To further expand the scope of this application, it is necessary to secure additional reliability through continuous comparative monitoring using the test data and physical properties of various corrugated fiberboards.

Insulation Performance of Building Components and Effect on the Cooling Load of Homes in Saudi Arabia

A common practice in the construction of residential and commercial buildings in Saudi Arabia is to insulate the outer walls and windows only. Other building components such as the roof, columns and slabs, and doors are usually neglected. Moreover, vital components such as the roof and windows are especially neglected in commercially built residential and commercial buildings. The aim of this study is to put this common impression and practice to the test by quantifying the contribution of every building component to the overall air-conditioning load of the building. The hypothesis evaluated in this paper is that despite the common practices, there could be an optimum selection of insulators for the building components that yields the lowest energy consumption and maximum savings not only in energy costs but also installation costs. The required air-conditioning load is determined using manual calculations and the HAP software package for 1022 possible configurations. The findings of the analysis point to the importance of the roof, as it is the major contributor to the thermal load, followed closely by columns and slabs, with 44.2% of the overall cooling load. It is found that a single wall consisting of 2 cm of cement plaster, 20 cm of cement–polyurethane brick, and 2 cm of cement plaster is less expensive and has higher thermal resistance than any of the more expensive double walls. The study found one scenario of possible configurations with the optimized selection of building materials and their insulation materials that provides the most effective insulation at the lowest cost.

Thermal analysis of guide vanes with full double wall cooling structure with focusing on leading edge cooling

In order to explore the thermal characteristics of the leading edge structure of the full double wall cooling structure guide vane, a double wall cooling structure guide vane is established on the basis of the vane model and the proven simulation method including of k-ε model and Fluid-Structure interaction method. Air film holes, impingement holes and spoiler columns with different forms are constructed at the leading edge of the vane, and the thermal characteristics of various structures are discussed through 3D simulation under many kinds of cooling conditions. The 30° left deviation of air film hole with good combination of dynamic and static pressure showed the most excellent air film coverage effect. The scheme of adding a row of impingement holes has better air film effect than the scheme of increasing the diameter of the impingement holes, due to the fact that the high-speed airflow from large diameter impingement hole accounts for about only 50% of the total airflow. The flow turbulence degree in the 30° left-deviation air film hole is much higher than that of the vertical angle. The compound angle and spoiler columns in local design can improve the local cooling effect, on the outer and inner surfaces of the vanes, respectively.

Study on a temperature change phenomenon of gas flow into a negatively-pressured canister

We have been investigating methods for detecting gas leaks from the canister of the concrete cask, which stores spent fuel, by using a temperature change of the canister surface at the time of the leak. This time, we investigated a temperature change inside and outside the canister when gas flowed into due to loss of containment in a negatively-pressured canister by using a small canister model with a simplified internal structure. The kind of internal gas, initial pressure conditions, gas mixing conditions, and a heat rate were used as parameters to clarify the temperature change phenomenon inside and outside the canister before and after the leak at negative pressure. Furthermore, the sensitivity of the leak detection method using the temperature change of the canister surface under each experimental condition was examined, and its practicability to the negatively-pressured canister was confirmed. In the case of the negative pressure, there is a concern that air may enter the canister and oxidize the fuel at loss of containment of the canister. However, using a double wall canister with inert gas filled between the canisters would solve this concern.

Evolution of switching fields caused by reorientation of GdFeCo/Ir/GdFeCo synthetic ferrimagnet in magnetic field

Anomalous Hall effect (AHE) in GdFeCo/Ir/GdFeCo multilayered structures attracts great interest because all optical switching, spin-torque, and other effects promise effective application for ultrafast memory element creation. Since AHE is controlled by GdFeCo magnetization, domain dynamics has importance for practical applications. In our work, magnetization reversal in perpendicular GdFeCo/Ir/GdFeCo synthetic ferrimagnets is characterized by AHE measurements. The AHE hysteresis loop obtained with the field applied perpendicular to the sample plane is composed of three sub-loops, and two of them are symmetrically biased with respect to the third one. Switching magnetic fields for two of the three transitions are found to be dependent on magnetic history. In particular, exposure of the sample in the in-plane field leads to reduction of the out-of-plane switching fields in side sub-loops. A multiple series of perpendicular hysteresis loops recorded after exposure under high in-plane field reveals gradual (within 30 min) relaxation of the out-of-plane switching fields to their initial values observed in a non-magnetized sample. Domain wall mobility, limiting switching of the bilayer devices, is complicated due to the coupling between partial domains in each single layer. Unusual dynamics of double domain walls results in unexpected new phenomena affecting electrical processes in bilayer structures.

ATHENA Main Heat Exchanger Conceptual Design and Thermal-Hydraulic Assessment With RELAP5 Code

Abstract Among the envisaged experimental infrastructures supporting ALFRED reactor development, Fostering Alfred Construction consortium identified ATHENA as one of the facilities to address the pool thermal-hydraulic challenges and demonstrate the feasibility of the revised ALFRED configuration, along with the thermal-hydraulic performances of its main components. ATHENA is a large pool-type lead-cooled multipurpose experimental facility featuring a large size vessel (3.2 m diameter, 10 m in height), conceived to host almost 800 tons of lead to test ALFRED relevant scaled components. The test section to be installed in the main vessel includes an electrically heated core simulator (CS), made of 7 FAs, which delivers to the primary coolant a nominal thermal power of 2210 kW, a main coolant pump for lead circulation, and a countercurrent shell and tubes main heat exchanger, which tube bundle is fed by pressurized water by a dedicated secondary circuit. A preliminary analytical calculation has been performed to identify the most suitable configuration for the ATHENA heat exchanger, as well as to achieve a preliminary sizing of the component. The final layout foresees a bundle of 91 bayonet tubes, arranged in a cylindrical geometry, having an active length of 3000 mm and adopting an external double wall tube with a pressurized helium gap. A numerical model of the heat exchanger has been developed using the thermal-hydraulic system code RELAP5/Mod3.3, and a numerical sensitivity analysis on the geometrical and operating parameters has been carried out to verify the performances of the component.

Experimental and numerical study on seismic performance of concrete-infilled double steel corrugated-plate walls

The Concrete-infilled Double Steel Corrugated-plate Wall (CDSCW) consists of a corrugated part and vertical boundary elements. The corrugated part is composed of outer steel corrugated plates (SCPs), infilled concrete, and intermediate bolts connecting the outer plates. The vertical boundary elements may adopt the concrete-filled steel tubes (CFSTs). This paper presents experimental and numerical investigations into the seismic performance of CDSCWs. Firstly, two specimens with different axial compression ratios were tested under combined axial compression and cyclic lateral loads. The experimental results indicated that the CDSCWs had significant ductility and excellent seismic performance. It was observed that the sufficient strength and stiffness of boundary elements were vital in achieving high load-bearing capacity and ductility of CDSCWs. The failure of the experimental specimens was closely related to the axial compression ratio, involving local buckling and fracture of SCPs and steel tubes and crushing of the infilled concrete. Subsequently, an additional numerical investigation into the performance of CDSCWs was carried out using a finite element (FE) model validated through the test data. The effects of the shear span-to-depth ratio, the axial compression ratio, the strength and stiffness of the boundary elements, and the width-to-thickness ratio of the steel tubes on the load-bearing capacities of CDSCWs are involved in this investigation. It is found that the CDSCWs with small shear span-to-depth ratios are mainly subjected to bending-shear failure, while those with large shear span-to-depth ratios are subjected to compression-bending failure. The strength and ductility of CDSCWs could be improved by strengthening the strength and stiffness of the boundary elements and limiting the width-to-thickness ratio of steel tubes. The conclusions obtained can provide fundamentals for further improving the strength design of CDSCWs.

Xylem anatomical and hydraulic traits vary within crown but not respond to water and nitrogen addition in Populus tomentosa

Nitrogen (N) and water availability are the two crucial factors confining tree growth and forest productivity. Irrigation, fertilization, and combined fertigation are commonly applied to plantation forests for improving productivity. However, how xylem vasculature responds to these management practices remains poorly understood. Here we investigated the responses of tree growth, xylem anatomical structure, and hydraulics of the upper, middle, and lower canopy branches in a 6-year-old Populus tomentosa plantation subjected to four years of irrigation and fertigation treatments. The results showed that an improvement in tree growth only occurred in the irrigation treatment while the addition of N in fertigation treatments did not have a cumulative effect on tree growth. Most of the xylem anatomical traits, including vessel hydraulic diameter (Dh), vessel density (VD), vessel fraction (VF), double vessel wall thickness (t), potential specific sapwood hydraulic conductivity (Kp), fiber wall to lumen ratio (Tf/Df), vessel wall reinforcement (t/b)2, and wood density (WD) all showed conserved plasticity to long-term irrigation and fertigation, despite different tree growth rate, implying that aboveground biomass accumulation may have decoupled from the branch-level xylem traits. Besides, the alterations of other factors, including stomatal regulation strategy and crown structure with soil water and N availabilities, might better explain the variation in tree growth. In contrast, greater variations in branch xylem traits were detected across canopy layers. The upper canopy showed greater hydraulic safety characterized by narrower and denser vessels, higher cell wall to lumen ratio, and higher wood density compared to the lower canopy, while hydraulic efficiency (Kp) remained constant across the crown, thus highlighting the priority of hydraulic safety over efficiency in the construction of branch xylem. Overall, our study revealed the response pattern of P. tomentosa xylem structure to long-term water and N management, which facilitates a comprehensive understanding on the mechanisms underpinning the influence of water and nutrients regulation on the performance of fast-growing tree species’ plantations.

A versatile cryogenic system for liquid argon detectors

Detectors for direct dark matter search using noble gases in the liquid phase as a detection medium need to be coupled to liquefaction, purification and recirculation systems. A dedicated cryogenic system has been assembled and operated at the INFN-Naples cryogenic laboratory with the aim to liquefy and purify the argon used as an active target in liquid argon detectors to study the scintillation and ionization signals detected by large SiPM arrays. The cryogenic system is mainly composed of a double wall cryostat hosting the detector, a purification stage to reduce the impurities below one part per billion level, a condenser to liquefy the argon, and a recirculation gas panel connected to the cryostat equipped with a custom gas pump. The main features of the cryogenic system are reported as well as the performance, long term operation and stability in terms of the most relevant thermodynamic parameters.

Thermal performance assessment of double hollow brick walls filled with hemp concrete insulation material through computational fluid dynamics analysis and dynamic thermal simulations

Thermal insulation is the most widely used solution to reduce the energy consumption of buildings. In order to minimize the cost and time needed to build an insulated wall as well as to decrease greenhouse gas emissions, this manuscript proposes to incorporate a bio-based insulation material into the air cavities of hollow bricks constituting the external walls of buildings. Therefore, the aim of this paper deals with the assessment of the thermal performance of Moroccan external building envelope constituted of double hollow brick walls filled with hemp concrete and separated by a 5 cm air layer thickness. Three configurations composed of three types of hollow bricks were studied (8-, 12- and 16-holed bricks). Firstly, using numerical simulations based on a two-dimensional Computational Fluid Dynamics (CFD) method, a parametric study was conducted in order to determine which of the three configurations meet with the requirements imposed by the Moroccan thermal building regulation. In terms of thermal resistance R and thermal transmission coefficient U, results have shown that double brick walls with 12 and 16 hemp concrete filled holes were the only configurations meeting the requirements of Moroccan Thermal Regulation. Afterwards, the study was revolved at a whole building scale and a dynamic thermal simulation considering various internal parameters was performed using TRNSYS software. Furthermore, an economic and environmental analysis was conducted and a comparison with Moroccan thermal regulation shows that our results perfectly meet the requirements of this regulation and are more efficient from thermal, economic and environmental perspectives. Finally, the insulation technique used in this investigation can be widely applied around the World and similar thermal performances can be achieved for the case of different regions characterized by the same Mediterranean warm climate considered in this paper.

Numerical investigation of sound transmission through single and double walls with periodic arrays of resonators

Lightweight partition walls are widely used in buildings, especially nowadays when sustainability is of a major interest. At the same time noise pollution is becoming a growing problem across the globe. All this implies the need to find possible solutions for sound insulation improvement of the lightweight partitions. This paper is focused on exploring the possibilities of exploiting the dynamic effects of periodic subwavelength arrays of resonators for sound insulation enhancement. In order to improve the sound transmission loss in a specific frequency region, periodic resonant units are tuned and introduced to single and double panels. It can be shown that the resonance mode of the resonators couples with the host plate vibration in the way of breaking the mass law and overcoming some phenomena like coincidence effect and mass-air-mass resonance. The investigation of the considered panels under acoustic field excitation is conducted using different methods. Sound transmission loss curves and dispersion diagrams are calculated. Finite element method is employed for this purpose, but also the theory of three-dimensional elasticity and well-known transfer matrix method (TMM). Several designs of resonators are proposed.

Can you really put a price on a good night's sleep?

This article focuses on estimation of willingness of people to pay extra price for increased sound insulation quality. As a case study a typical 3 room apartment in Bratislava was chosen. Online listening tests were used as a tool to understand the preferred price-quality ratio. The primary financial value of a case study apartment was estimated on real estate market in the third quarter of 2020. Later, nine (9) different variants of sound insulation of partition walls separating dwellings were considered. These walls were chosen on basis of different construction system (1) heavy weight brick walls, (1) light-weight gypsum board walls and (2) double walls. Each construction base was divided into three categories of defined by weighed sound transmission index Rw (53 dB, 55 dB and 59 dB). The four types of sounds (pink noise, cough, quarrel, party noise) were filtered through the frequency spectra R(dB) of chosen walls. These sounds were presented during the online listening test along with a total price for the particular apartment. The test subjects were asked to decide, which apartment they would choose based on an increased acoustic comfort and increased price of the apartment. In total, 60 subjects performed the test.

Prediction of vibration transmission across finite double wall junctions using a hybrid diffuse-deterministic approach.

Predicting the sound insulation between two rooms is a complex problem since not only the direct path through the separating element but also the flanking transmission paths can largely influence the sound insulation of the system. An important parameter for calculating flanking transmission is the vibration reduction index, which relates to the transmission coefficient between the connected plates. The international building acoustics standard ISO 12354-1/2 provides prediction formulas for the vibration reduction index of single wall junctions, but not for double wall junctions. A new hybrid-deterministic approach is proposed to calculate flanking transmission across double wall junctions. The walls and floors are modelled as diffuse subsystems while the connection between the double wall is modelled deterministically. This approach relies on the diffuse field reciprocity relationship, which relates the vibration transmission to the direct field dynamic stiffness of the subsystems (walls and floors), i.e., the dynamic stiffness of the equivalent infinite subsystem as observed at the junction. In contrast to existing approaches, the finite size of the junction is properly taken into account in this way. The new approach is applied to different types of double wall junctions to determine simplified regression formulas for practical sound insulation design.